Move files to match FreeBSD layout

1 files changed, 5492 insertions, 0 deletions

diff --git a/freebsd/sys/net/if_spppsubr.c b/freebsd/sys/net/if_spppsubr.c
new file mode 100644
index 00000000..235ef7c0
--- /dev/null
+++ b/freebsd/sys/net/if_spppsubr.c
@@ -0,0 +1,5492 @@
+#include <freebsd/machine/rtems-bsd-config.h>
+
+/*
+ * Synchronous PPP/Cisco/Frame Relay link level subroutines.
+ * Keepalive protocol implemented in both Cisco and PPP modes.
+ */
+/*-
+ * Copyright (C) 1994-2000 Cronyx Engineering.
+ * Author: Serge Vakulenko, <vak@cronyx.ru>
+ *
+ * Heavily revamped to conform to RFC 1661.
+ * Copyright (C) 1997, 2001 Joerg Wunsch.
+ *
+ * This software is distributed with NO WARRANTIES, not even the implied
+ * warranties for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+ *
+ * Authors grant any other persons or organisations permission to use
+ * or modify this software as long as this message is kept with the software,
+ * all derivative works or modified versions.
+ *
+ * From: Version 2.4, Thu Apr 30 17:17:21 MSD 1997
+ *
+ * $FreeBSD$
+ */
+
+#include <freebsd/sys/param.h>
+
+#include <freebsd/local/opt_inet.h>
+#include <freebsd/local/opt_inet6.h>
+#include <freebsd/local/opt_ipx.h>
+
+#include <freebsd/sys/systm.h>
+#include <freebsd/sys/kernel.h>
+#include <freebsd/sys/module.h>
+#include <freebsd/sys/sockio.h>
+#include <freebsd/sys/socket.h>
+#include <freebsd/sys/syslog.h>
+#include <freebsd/sys/random.h>
+#include <freebsd/sys/malloc.h>
+#include <freebsd/sys/mbuf.h>
+
+#include <freebsd/sys/md5.h>
+
+#include <freebsd/net/if.h>
+#include <freebsd/net/netisr.h>
+#include <freebsd/net/if_types.h>
+#include <freebsd/net/route.h>
+#include <freebsd/net/vnet.h>
+#include <freebsd/netinet/in.h>
+#include <freebsd/netinet/in_systm.h>
+#include <freebsd/netinet/ip.h>
+#include <freebsd/net/slcompress.h>
+
+#include <freebsd/machine/stdarg.h>
+
+#include <freebsd/netinet/in_var.h>
+
+#ifdef INET
+#include <freebsd/netinet/ip.h>
+#include <freebsd/netinet/tcp.h>
+#endif
+
+#ifdef INET6
+#include <freebsd/netinet6/scope6_var.h>
+#endif
+
+#include <freebsd/netinet/if_ether.h>
+
+#ifdef IPX
+#include <freebsd/netipx/ipx.h>
+#include <freebsd/netipx/ipx_if.h>
+#endif
+
+#include <freebsd/net/if_sppp.h>
+
+#define IOCTL_CMD_T	u_long
+#define MAXALIVECNT     3               /* max. alive packets */
+
+/*
+ * Interface flags that can be set in an ifconfig command.
+ *
+ * Setting link0 will make the link passive, i.e. it will be marked
+ * as being administrative openable, but won't be opened to begin
+ * with.  Incoming calls will be answered, or subsequent calls with
+ * -link1 will cause the administrative open of the LCP layer.
+ *
+ * Setting link1 will cause the link to auto-dial only as packets
+ * arrive to be sent.
+ *
+ * Setting IFF_DEBUG will syslog the option negotiation and state
+ * transitions at level kern.debug.  Note: all logs consistently look
+ * like
+ *
+ *   <if-name><unit>: <proto-name> <additional info...>
+ *
+ * with <if-name><unit> being something like "bppp0", and <proto-name>
+ * being one of "lcp", "ipcp", "cisco", "chap", "pap", etc.
+ */
+
+#define IFF_PASSIVE	IFF_LINK0	/* wait passively for connection */
+#define IFF_AUTO	IFF_LINK1	/* auto-dial on output */
+#define IFF_CISCO	IFF_LINK2	/* auto-dial on output */
+
+#define PPP_ALLSTATIONS 0xff		/* All-Stations broadcast address */
+#define PPP_UI		0x03		/* Unnumbered Information */
+#define PPP_IP		0x0021		/* Internet Protocol */
+#define PPP_ISO		0x0023		/* ISO OSI Protocol */
+#define PPP_XNS		0x0025		/* Xerox NS Protocol */
+#define PPP_IPX		0x002b		/* Novell IPX Protocol */
+#define PPP_VJ_COMP	0x002d		/* VJ compressed TCP/IP */
+#define PPP_VJ_UCOMP	0x002f		/* VJ uncompressed TCP/IP */
+#define PPP_IPV6	0x0057		/* Internet Protocol Version 6 */
+#define PPP_LCP		0xc021		/* Link Control Protocol */
+#define PPP_PAP		0xc023		/* Password Authentication Protocol */
+#define PPP_CHAP	0xc223		/* Challenge-Handshake Auth Protocol */
+#define PPP_IPCP	0x8021		/* Internet Protocol Control Protocol */
+#define PPP_IPV6CP	0x8057		/* IPv6 Control Protocol */
+
+#define CONF_REQ	1		/* PPP configure request */
+#define CONF_ACK	2		/* PPP configure acknowledge */
+#define CONF_NAK	3		/* PPP configure negative ack */
+#define CONF_REJ	4		/* PPP configure reject */
+#define TERM_REQ	5		/* PPP terminate request */
+#define TERM_ACK	6		/* PPP terminate acknowledge */
+#define CODE_REJ	7		/* PPP code reject */
+#define PROTO_REJ	8		/* PPP protocol reject */
+#define ECHO_REQ	9		/* PPP echo request */
+#define ECHO_REPLY	10		/* PPP echo reply */
+#define DISC_REQ	11		/* PPP discard request */
+
+#define LCP_OPT_MRU		1	/* maximum receive unit */
+#define LCP_OPT_ASYNC_MAP	2	/* async control character map */
+#define LCP_OPT_AUTH_PROTO	3	/* authentication protocol */
+#define LCP_OPT_QUAL_PROTO	4	/* quality protocol */
+#define LCP_OPT_MAGIC		5	/* magic number */
+#define LCP_OPT_RESERVED	6	/* reserved */
+#define LCP_OPT_PROTO_COMP	7	/* protocol field compression */
+#define LCP_OPT_ADDR_COMP	8	/* address/control field compression */
+
+#define IPCP_OPT_ADDRESSES	1	/* both IP addresses; deprecated */
+#define IPCP_OPT_COMPRESSION	2	/* IP compression protocol (VJ) */
+#define IPCP_OPT_ADDRESS	3	/* local IP address */
+
+#define IPV6CP_OPT_IFID	1	/* interface identifier */
+#define IPV6CP_OPT_COMPRESSION	2	/* IPv6 compression protocol */
+
+#define IPCP_COMP_VJ		0x2d	/* Code for VJ compression */
+
+#define PAP_REQ			1	/* PAP name/password request */
+#define PAP_ACK			2	/* PAP acknowledge */
+#define PAP_NAK			3	/* PAP fail */
+
+#define CHAP_CHALLENGE		1	/* CHAP challenge request */
+#define CHAP_RESPONSE		2	/* CHAP challenge response */
+#define CHAP_SUCCESS		3	/* CHAP response ok */
+#define CHAP_FAILURE		4	/* CHAP response failed */
+
+#define CHAP_MD5		5	/* hash algorithm - MD5 */
+
+#define CISCO_MULTICAST		0x8f	/* Cisco multicast address */
+#define CISCO_UNICAST		0x0f	/* Cisco unicast address */
+#define CISCO_KEEPALIVE		0x8035	/* Cisco keepalive protocol */
+#define CISCO_ADDR_REQ		0	/* Cisco address request */
+#define CISCO_ADDR_REPLY	1	/* Cisco address reply */
+#define CISCO_KEEPALIVE_REQ	2	/* Cisco keepalive request */
+
+/* states are named and numbered according to RFC 1661 */
+#define STATE_INITIAL	0
+#define STATE_STARTING	1
+#define STATE_CLOSED	2
+#define STATE_STOPPED	3
+#define STATE_CLOSING	4
+#define STATE_STOPPING	5
+#define STATE_REQ_SENT	6
+#define STATE_ACK_RCVD	7
+#define STATE_ACK_SENT	8
+#define STATE_OPENED	9
+
+MALLOC_DEFINE(M_SPPP, "sppp", "synchronous PPP interface internals");
+
+struct ppp_header {
+	u_char address;
+	u_char control;
+	u_short protocol;
+} __packed;
+#define PPP_HEADER_LEN          sizeof (struct ppp_header)
+
+struct lcp_header {
+	u_char type;
+	u_char ident;
+	u_short len;
+} __packed;
+#define LCP_HEADER_LEN          sizeof (struct lcp_header)
+
+struct cisco_packet {
+	u_long type;
+	u_long par1;
+	u_long par2;
+	u_short rel;
+	u_short time0;
+	u_short time1;
+} __packed;
+#define CISCO_PACKET_LEN	sizeof (struct cisco_packet)
+
+/*
+ * We follow the spelling and capitalization of RFC 1661 here, to make
+ * it easier comparing with the standard.  Please refer to this RFC in
+ * case you can't make sense out of these abbreviation; it will also
+ * explain the semantics related to the various events and actions.
+ */
+struct cp {
+	u_short	proto;		/* PPP control protocol number */
+	u_char protoidx;	/* index into state table in struct sppp */
+	u_char flags;
+#define CP_LCP		0x01	/* this is the LCP */
+#define CP_AUTH		0x02	/* this is an authentication protocol */
+#define CP_NCP		0x04	/* this is a NCP */
+#define CP_QUAL		0x08	/* this is a quality reporting protocol */
+	const char *name;	/* name of this control protocol */
+	/* event handlers */
+	void	(*Up)(struct sppp *sp);
+	void	(*Down)(struct sppp *sp);
+	void	(*Open)(struct sppp *sp);
+	void	(*Close)(struct sppp *sp);
+	void	(*TO)(void *sp);
+	int	(*RCR)(struct sppp *sp, struct lcp_header *h, int len);
+	void	(*RCN_rej)(struct sppp *sp, struct lcp_header *h, int len);
+	void	(*RCN_nak)(struct sppp *sp, struct lcp_header *h, int len);
+	/* actions */
+	void	(*tlu)(struct sppp *sp);
+	void	(*tld)(struct sppp *sp);
+	void	(*tls)(struct sppp *sp);
+	void	(*tlf)(struct sppp *sp);
+	void	(*scr)(struct sppp *sp);
+};
+
+#define	SPP_FMT		"%s: "
+#define	SPP_ARGS(ifp)	(ifp)->if_xname
+
+#define SPPP_LOCK(sp)	mtx_lock (&(sp)->mtx)
+#define SPPP_UNLOCK(sp)	mtx_unlock (&(sp)->mtx)
+#define SPPP_LOCK_ASSERT(sp)	mtx_assert (&(sp)->mtx, MA_OWNED)
+#define SPPP_LOCK_OWNED(sp)	mtx_owned (&(sp)->mtx)
+
+#ifdef INET
+/*
+ * The following disgusting hack gets around the problem that IP TOS
+ * can't be set yet.  We want to put "interactive" traffic on a high
+ * priority queue.  To decide if traffic is interactive, we check that
+ * a) it is TCP and b) one of its ports is telnet, rlogin or ftp control.
+ *
+ * XXX is this really still necessary?  - joerg -
+ */
+static const u_short interactive_ports[8] = {
+	0,	513,	0,	0,
+	0,	21,	0,	23,
+};
+#define INTERACTIVE(p) (interactive_ports[(p) & 7] == (p))
+#endif
+
+/* almost every function needs these */
+#define STDDCL							\
+	struct ifnet *ifp = SP2IFP(sp);				\
+	int debug = ifp->if_flags & IFF_DEBUG
+
+static int sppp_output(struct ifnet *ifp, struct mbuf *m,
+		       struct sockaddr *dst, struct route *ro);
+
+static void sppp_cisco_send(struct sppp *sp, int type, long par1, long par2);
+static void sppp_cisco_input(struct sppp *sp, struct mbuf *m);
+
+static void sppp_cp_input(const struct cp *cp, struct sppp *sp,
+			  struct mbuf *m);
+static void sppp_cp_send(struct sppp *sp, u_short proto, u_char type,
+			 u_char ident, u_short len, void *data);
+/* static void sppp_cp_timeout(void *arg); */
+static void sppp_cp_change_state(const struct cp *cp, struct sppp *sp,
+				 int newstate);
+static void sppp_auth_send(const struct cp *cp,
+			   struct sppp *sp, unsigned int type, unsigned int id,
+			   ...);
+
+static void sppp_up_event(const struct cp *cp, struct sppp *sp);
+static void sppp_down_event(const struct cp *cp, struct sppp *sp);
+static void sppp_open_event(const struct cp *cp, struct sppp *sp);
+static void sppp_close_event(const struct cp *cp, struct sppp *sp);
+static void sppp_to_event(const struct cp *cp, struct sppp *sp);
+
+static void sppp_null(struct sppp *sp);
+
+static void sppp_pp_up(struct sppp *sp);
+static void sppp_pp_down(struct sppp *sp);
+
+static void sppp_lcp_init(struct sppp *sp);
+static void sppp_lcp_up(struct sppp *sp);
+static void sppp_lcp_down(struct sppp *sp);
+static void sppp_lcp_open(struct sppp *sp);
+static void sppp_lcp_close(struct sppp *sp);
+static void sppp_lcp_TO(void *sp);
+static int sppp_lcp_RCR(struct sppp *sp, struct lcp_header *h, int len);
+static void sppp_lcp_RCN_rej(struct sppp *sp, struct lcp_header *h, int len);
+static void sppp_lcp_RCN_nak(struct sppp *sp, struct lcp_header *h, int len);
+static void sppp_lcp_tlu(struct sppp *sp);
+static void sppp_lcp_tld(struct sppp *sp);
+static void sppp_lcp_tls(struct sppp *sp);
+static void sppp_lcp_tlf(struct sppp *sp);
+static void sppp_lcp_scr(struct sppp *sp);
+static void sppp_lcp_check_and_close(struct sppp *sp);
+static int sppp_ncp_check(struct sppp *sp);
+
+static void sppp_ipcp_init(struct sppp *sp);
+static void sppp_ipcp_up(struct sppp *sp);
+static void sppp_ipcp_down(struct sppp *sp);
+static void sppp_ipcp_open(struct sppp *sp);
+static void sppp_ipcp_close(struct sppp *sp);
+static void sppp_ipcp_TO(void *sp);
+static int sppp_ipcp_RCR(struct sppp *sp, struct lcp_header *h, int len);
+static void sppp_ipcp_RCN_rej(struct sppp *sp, struct lcp_header *h, int len);
+static void sppp_ipcp_RCN_nak(struct sppp *sp, struct lcp_header *h, int len);
+static void sppp_ipcp_tlu(struct sppp *sp);
+static void sppp_ipcp_tld(struct sppp *sp);
+static void sppp_ipcp_tls(struct sppp *sp);
+static void sppp_ipcp_tlf(struct sppp *sp);
+static void sppp_ipcp_scr(struct sppp *sp);
+
+static void sppp_ipv6cp_init(struct sppp *sp);
+static void sppp_ipv6cp_up(struct sppp *sp);
+static void sppp_ipv6cp_down(struct sppp *sp);
+static void sppp_ipv6cp_open(struct sppp *sp);
+static void sppp_ipv6cp_close(struct sppp *sp);
+static void sppp_ipv6cp_TO(void *sp);
+static int sppp_ipv6cp_RCR(struct sppp *sp, struct lcp_header *h, int len);
+static void sppp_ipv6cp_RCN_rej(struct sppp *sp, struct lcp_header *h, int len);
+static void sppp_ipv6cp_RCN_nak(struct sppp *sp, struct lcp_header *h, int len);
+static void sppp_ipv6cp_tlu(struct sppp *sp);
+static void sppp_ipv6cp_tld(struct sppp *sp);
+static void sppp_ipv6cp_tls(struct sppp *sp);
+static void sppp_ipv6cp_tlf(struct sppp *sp);
+static void sppp_ipv6cp_scr(struct sppp *sp);
+
+static void sppp_pap_input(struct sppp *sp, struct mbuf *m);
+static void sppp_pap_init(struct sppp *sp);
+static void sppp_pap_open(struct sppp *sp);
+static void sppp_pap_close(struct sppp *sp);
+static void sppp_pap_TO(void *sp);
+static void sppp_pap_my_TO(void *sp);
+static void sppp_pap_tlu(struct sppp *sp);
+static void sppp_pap_tld(struct sppp *sp);
+static void sppp_pap_scr(struct sppp *sp);
+
+static void sppp_chap_input(struct sppp *sp, struct mbuf *m);
+static void sppp_chap_init(struct sppp *sp);
+static void sppp_chap_open(struct sppp *sp);
+static void sppp_chap_close(struct sppp *sp);
+static void sppp_chap_TO(void *sp);
+static void sppp_chap_tlu(struct sppp *sp);
+static void sppp_chap_tld(struct sppp *sp);
+static void sppp_chap_scr(struct sppp *sp);
+
+static const char *sppp_auth_type_name(u_short proto, u_char type);
+static const char *sppp_cp_type_name(u_char type);
+#ifdef INET
+static const char *sppp_dotted_quad(u_long addr);
+static const char *sppp_ipcp_opt_name(u_char opt);
+#endif
+#ifdef INET6
+static const char *sppp_ipv6cp_opt_name(u_char opt);
+#endif
+static const char *sppp_lcp_opt_name(u_char opt);
+static const char *sppp_phase_name(enum ppp_phase phase);
+static const char *sppp_proto_name(u_short proto);
+static const char *sppp_state_name(int state);
+static int sppp_params(struct sppp *sp, u_long cmd, void *data);
+static int sppp_strnlen(u_char *p, int max);
+static void sppp_keepalive(void *dummy);
+static void sppp_phase_network(struct sppp *sp);
+static void sppp_print_bytes(const u_char *p, u_short len);
+static void sppp_print_string(const char *p, u_short len);
+static void sppp_qflush(struct ifqueue *ifq);
+#ifdef INET
+static void sppp_set_ip_addr(struct sppp *sp, u_long src);
+#endif
+#ifdef INET6
+static void sppp_get_ip6_addrs(struct sppp *sp, struct in6_addr *src,
+			       struct in6_addr *dst, struct in6_addr *srcmask);
+#ifdef IPV6CP_MYIFID_DYN
+static void sppp_set_ip6_addr(struct sppp *sp, const struct in6_addr *src);
+static void sppp_gen_ip6_addr(struct sppp *sp, const struct in6_addr *src);
+#endif
+static void sppp_suggest_ip6_addr(struct sppp *sp, struct in6_addr *src);
+#endif
+
+/* if_start () wrapper */
+static void sppp_ifstart (struct ifnet *ifp);
+
+/* our control protocol descriptors */
+static const struct cp lcp = {
+	PPP_LCP, IDX_LCP, CP_LCP, "lcp",
+	sppp_lcp_up, sppp_lcp_down, sppp_lcp_open, sppp_lcp_close,
+	sppp_lcp_TO, sppp_lcp_RCR, sppp_lcp_RCN_rej, sppp_lcp_RCN_nak,
+	sppp_lcp_tlu, sppp_lcp_tld, sppp_lcp_tls, sppp_lcp_tlf,
+	sppp_lcp_scr
+};
+
+static const struct cp ipcp = {
+	PPP_IPCP, IDX_IPCP,
+#ifdef INET	/* don't run IPCP if there's no IPv4 support */
+	CP_NCP,
+#else
+	0,
+#endif
+	"ipcp",
+	sppp_ipcp_up, sppp_ipcp_down, sppp_ipcp_open, sppp_ipcp_close,
+	sppp_ipcp_TO, sppp_ipcp_RCR, sppp_ipcp_RCN_rej, sppp_ipcp_RCN_nak,
+	sppp_ipcp_tlu, sppp_ipcp_tld, sppp_ipcp_tls, sppp_ipcp_tlf,
+	sppp_ipcp_scr
+};
+
+static const struct cp ipv6cp = {
+	PPP_IPV6CP, IDX_IPV6CP,
+#ifdef INET6	/*don't run IPv6CP if there's no IPv6 support*/
+	CP_NCP,
+#else
+	0,
+#endif
+	"ipv6cp",
+	sppp_ipv6cp_up, sppp_ipv6cp_down, sppp_ipv6cp_open, sppp_ipv6cp_close,
+	sppp_ipv6cp_TO, sppp_ipv6cp_RCR, sppp_ipv6cp_RCN_rej, sppp_ipv6cp_RCN_nak,
+	sppp_ipv6cp_tlu, sppp_ipv6cp_tld, sppp_ipv6cp_tls, sppp_ipv6cp_tlf,
+	sppp_ipv6cp_scr
+};
+
+static const struct cp pap = {
+	PPP_PAP, IDX_PAP, CP_AUTH, "pap",
+	sppp_null, sppp_null, sppp_pap_open, sppp_pap_close,
+	sppp_pap_TO, 0, 0, 0,
+	sppp_pap_tlu, sppp_pap_tld, sppp_null, sppp_null,
+	sppp_pap_scr
+};
+
+static const struct cp chap = {
+	PPP_CHAP, IDX_CHAP, CP_AUTH, "chap",
+	sppp_null, sppp_null, sppp_chap_open, sppp_chap_close,
+	sppp_chap_TO, 0, 0, 0,
+	sppp_chap_tlu, sppp_chap_tld, sppp_null, sppp_null,
+	sppp_chap_scr
+};
+
+static const struct cp *cps[IDX_COUNT] = {
+	&lcp,			/* IDX_LCP */
+	&ipcp,			/* IDX_IPCP */
+	&ipv6cp,		/* IDX_IPV6CP */
+	&pap,			/* IDX_PAP */
+	&chap,			/* IDX_CHAP */
+};
+
+static void*
+sppp_alloc(u_char type, struct ifnet *ifp)
+{
+	struct sppp	*sp;
+
+        sp = malloc(sizeof(struct sppp), M_SPPP, M_WAITOK | M_ZERO);
+	sp->pp_ifp = ifp;
+
+	return (sp);
+}
+
+static void
+sppp_free(void *com, u_char type)
+{
+
+	free(com, M_SPPP);
+}
+
+static int
+sppp_modevent(module_t mod, int type, void *unused)
+{
+	switch (type) {
+	case MOD_LOAD:
+		/*
+		 * XXX: should probably be IFT_SPPP, but it's fairly
+		 * harmless to allocate struct sppp's for non-sppp
+		 * interfaces.
+		 */
+
+		if_register_com_alloc(IFT_PPP, sppp_alloc, sppp_free);
+		break;
+	case MOD_UNLOAD:
+		/* if_deregister_com_alloc(IFT_PPP); */
+		return EACCES;
+	default:
+		return EOPNOTSUPP;
+	}
+	return 0;
+}
+static moduledata_t spppmod = {
+	"sppp",
+	sppp_modevent,
+	0
+};
+MODULE_VERSION(sppp, 1);
+DECLARE_MODULE(sppp, spppmod, SI_SUB_DRIVERS, SI_ORDER_ANY);
+
+/*
+ * Exported functions, comprising our interface to the lower layer.
+ */
+
+/*
+ * Process the received packet.
+ */
+void
+sppp_input(struct ifnet *ifp, struct mbuf *m)
+{
+	struct ppp_header *h;
+	int isr = -1;
+	struct sppp *sp = IFP2SP(ifp);
+	int debug, do_account = 0;
+#ifdef INET
+	int hlen, vjlen;
+	u_char *iphdr;
+#endif
+
+	SPPP_LOCK(sp);
+	debug = ifp->if_flags & IFF_DEBUG;
+
+	if (ifp->if_flags & IFF_UP)
+		/* Count received bytes, add FCS and one flag */
+		ifp->if_ibytes += m->m_pkthdr.len + 3;
+
+	if (m->m_pkthdr.len <= PPP_HEADER_LEN) {
+		/* Too small packet, drop it. */
+		if (debug)
+			log(LOG_DEBUG,
+			    SPP_FMT "input packet is too small, %d bytes\n",
+			    SPP_ARGS(ifp), m->m_pkthdr.len);
+	  drop:
+		m_freem (m);
+		SPPP_UNLOCK(sp);
+	  drop2:
+		++ifp->if_ierrors;
+		++ifp->if_iqdrops;
+		return;
+	}
+
+	if (sp->pp_mode == PP_FR) {
+		sppp_fr_input (sp, m);
+		SPPP_UNLOCK(sp);
+		return;
+	}
+
+	/* Get PPP header. */
+	h = mtod (m, struct ppp_header*);
+	m_adj (m, PPP_HEADER_LEN);
+
+	switch (h->address) {
+	case PPP_ALLSTATIONS:
+		if (h->control != PPP_UI)
+			goto invalid;
+		if (sp->pp_mode == IFF_CISCO) {
+			if (debug)
+				log(LOG_DEBUG,
+				    SPP_FMT "PPP packet in Cisco mode "
+				    "<addr=0x%x ctrl=0x%x proto=0x%x>\n",
+				    SPP_ARGS(ifp),
+				    h->address, h->control, ntohs(h->protocol));
+			goto drop;
+		}
+		switch (ntohs (h->protocol)) {
+		default:
+			if (debug)
+				log(LOG_DEBUG,
+				    SPP_FMT "rejecting protocol "
+				    "<addr=0x%x ctrl=0x%x proto=0x%x>\n",
+				    SPP_ARGS(ifp),
+				    h->address, h->control, ntohs(h->protocol));
+			if (sp->state[IDX_LCP] == STATE_OPENED)
+				sppp_cp_send (sp, PPP_LCP, PROTO_REJ,
+					++sp->pp_seq[IDX_LCP], m->m_pkthdr.len + 2,
+					&h->protocol);
+			++ifp->if_noproto;
+			goto drop;
+		case PPP_LCP:
+			sppp_cp_input(&lcp, sp, m);
+			m_freem (m);
+			SPPP_UNLOCK(sp);
+			return;
+		case PPP_PAP:
+			if (sp->pp_phase >= PHASE_AUTHENTICATE)
+				sppp_pap_input(sp, m);
+			m_freem (m);
+			SPPP_UNLOCK(sp);
+			return;
+		case PPP_CHAP:
+			if (sp->pp_phase >= PHASE_AUTHENTICATE)
+				sppp_chap_input(sp, m);
+			m_freem (m);
+			SPPP_UNLOCK(sp);
+			return;
+#ifdef INET
+		case PPP_IPCP:
+			if (sp->pp_phase == PHASE_NETWORK)
+				sppp_cp_input(&ipcp, sp, m);
+			m_freem (m);
+			SPPP_UNLOCK(sp);
+			return;
+		case PPP_IP:
+			if (sp->state[IDX_IPCP] == STATE_OPENED) {
+				isr = NETISR_IP;
+			}
+			do_account++;
+			break;
+		case PPP_VJ_COMP:
+			if (sp->state[IDX_IPCP] == STATE_OPENED) {
+				if ((vjlen =
+				     sl_uncompress_tcp_core(mtod(m, u_char *),
+							    m->m_len, m->m_len,
+							    TYPE_COMPRESSED_TCP,
+							    sp->pp_comp,
+							    &iphdr, &hlen)) <= 0) {
+					if (debug)
+						log(LOG_INFO,
+			    SPP_FMT "VJ uncompress failed on compressed packet\n",
+						    SPP_ARGS(ifp));
+					goto drop;
+				}
+
+				/*
+				 * Trim the VJ header off the packet, and prepend
+				 * the uncompressed IP header (which will usually
+				 * end up in two chained mbufs since there's not
+				 * enough leading space in the existing mbuf).
+				 */
+				m_adj(m, vjlen);
+				M_PREPEND(m, hlen, M_DONTWAIT);
+				if (m == NULL) {
+					SPPP_UNLOCK(sp);
+					goto drop2;
+				}
+				bcopy(iphdr, mtod(m, u_char *), hlen);
+				isr = NETISR_IP;
+			}
+			do_account++;
+			break;
+		case PPP_VJ_UCOMP:
+			if (sp->state[IDX_IPCP] == STATE_OPENED) {
+				if (sl_uncompress_tcp_core(mtod(m, u_char *),
+							   m->m_len, m->m_len,
+							   TYPE_UNCOMPRESSED_TCP,
+							   sp->pp_comp,
+							   &iphdr, &hlen) != 0) {
+					if (debug)
+						log(LOG_INFO,
+			    SPP_FMT "VJ uncompress failed on uncompressed packet\n",
+						    SPP_ARGS(ifp));
+					goto drop;
+				}
+				isr = NETISR_IP;
+			}
+			do_account++;
+			break;
+#endif
+#ifdef INET6
+		case PPP_IPV6CP:
+			if (sp->pp_phase == PHASE_NETWORK)
+			    sppp_cp_input(&ipv6cp, sp, m);
+			m_freem (m);
+			SPPP_UNLOCK(sp);
+			return;
+
+		case PPP_IPV6:
+			if (sp->state[IDX_IPV6CP] == STATE_OPENED)
+				isr = NETISR_IPV6;
+			do_account++;
+			break;
+#endif
+#ifdef IPX
+		case PPP_IPX:
+			/* IPX IPXCP not implemented yet */
+			if (sp->pp_phase == PHASE_NETWORK)
+				isr = NETISR_IPX;
+			do_account++;
+			break;
+#endif
+		}
+		break;
+	case CISCO_MULTICAST:
+	case CISCO_UNICAST:
+		/* Don't check the control field here (RFC 1547). */
+		if (sp->pp_mode != IFF_CISCO) {
+			if (debug)
+				log(LOG_DEBUG,
+				    SPP_FMT "Cisco packet in PPP mode "
+				    "<addr=0x%x ctrl=0x%x proto=0x%x>\n",
+				    SPP_ARGS(ifp),
+				    h->address, h->control, ntohs(h->protocol));
+			goto drop;
+		}
+		switch (ntohs (h->protocol)) {
+		default:
+			++ifp->if_noproto;
+			goto invalid;
+		case CISCO_KEEPALIVE:
+			sppp_cisco_input (sp, m);
+			m_freem (m);
+			SPPP_UNLOCK(sp);
+			return;
+#ifdef INET
+		case ETHERTYPE_IP:
+			isr = NETISR_IP;
+			do_account++;
+			break;
+#endif
+#ifdef INET6
+		case ETHERTYPE_IPV6:
+			isr = NETISR_IPV6;
+			do_account++;
+			break;
+#endif
+#ifdef IPX
+		case ETHERTYPE_IPX:
+			isr = NETISR_IPX;
+			do_account++;
+			break;
+#endif
+		}
+		break;
+	default:        /* Invalid PPP packet. */
+	  invalid:
+		if (debug)
+			log(LOG_DEBUG,
+			    SPP_FMT "invalid input packet "
+			    "<addr=0x%x ctrl=0x%x proto=0x%x>\n",
+			    SPP_ARGS(ifp),
+			    h->address, h->control, ntohs(h->protocol));
+		goto drop;
+	}
+
+	if (! (ifp->if_flags & IFF_UP) || isr == -1)
+		goto drop;
+
+	SPPP_UNLOCK(sp);
+	/* Check queue. */
+	if (netisr_queue(isr, m)) {	/* (0) on success. */
+		if (debug)
+			log(LOG_DEBUG, SPP_FMT "protocol queue overflow\n",
+				SPP_ARGS(ifp));
+		goto drop2;
+	}
+
+	if (do_account)
+		/*
+		 * Do only account for network packets, not for control
+		 * packets.  This is used by some subsystems to detect
+		 * idle lines.
+		 */
+		sp->pp_last_recv = time_uptime;
+}
+
+static void
+sppp_ifstart_sched(void *dummy)
+{
+	struct sppp *sp = dummy;
+	
+	sp->if_start(SP2IFP(sp));
+}
+
+/* if_start () wrapper function. We use it to schedule real if_start () for
+ * execution. We can't call it directly
+ */
+static void
+sppp_ifstart(struct ifnet *ifp)
+{
+	struct sppp *sp = IFP2SP(ifp);
+
+	if (SPPP_LOCK_OWNED(sp)) {
+		if (callout_pending(&sp->ifstart_callout))
+			return;
+		callout_reset(&sp->ifstart_callout, 1, sppp_ifstart_sched,
+		    (void *)sp); 
+	} else {
+		sp->if_start(ifp);
+	}
+}
+
+/*
+ * Enqueue transmit packet.
+ */
+static int
+sppp_output(struct ifnet *ifp, struct mbuf *m,
+	    struct sockaddr *dst, struct route *ro)
+{
+	struct sppp *sp = IFP2SP(ifp);
+	struct ppp_header *h;
+	struct ifqueue *ifq = NULL;
+	int s, error, rv = 0;
+#ifdef INET
+	int ipproto = PPP_IP;
+#endif
+	int debug = ifp->if_flags & IFF_DEBUG;
+
+	s = splimp();
+	SPPP_LOCK(sp);
+
+	if (!(ifp->if_flags & IFF_UP) ||
+	    (!(ifp->if_flags & IFF_AUTO) &&
+	    !(ifp->if_drv_flags & IFF_DRV_RUNNING))) {
+#ifdef INET6
+	  drop:
+#endif
+		m_freem (m);
+		SPPP_UNLOCK(sp);
+		splx (s);
+		return (ENETDOWN);
+	}
+
+	if ((ifp->if_flags & IFF_AUTO) &&
+	    !(ifp->if_drv_flags & IFF_DRV_RUNNING)) {
+#ifdef INET6
+		/*
+		 * XXX
+		 *
+		 * Hack to prevent the initialization-time generated
+		 * IPv6 multicast packet to erroneously cause a
+		 * dialout event in case IPv6 has been
+		 * administratively disabled on that interface.
+		 */
+		if (dst->sa_family == AF_INET6 &&
+		    !(sp->confflags & CONF_ENABLE_IPV6))
+			goto drop;
+#endif
+		/*
+		 * Interface is not yet running, but auto-dial.  Need
+		 * to start LCP for it.
+		 */
+		ifp->if_drv_flags |= IFF_DRV_RUNNING;
+		splx(s);
+		lcp.Open(sp);
+		s = splimp();
+	}
+
+#ifdef INET
+	if (dst->sa_family == AF_INET) {
+		/* XXX Check mbuf length here? */
+		struct ip *ip = mtod (m, struct ip*);
+		struct tcphdr *tcp = (struct tcphdr*) ((long*)ip + ip->ip_hl);
+
+		/*
+		 * When using dynamic local IP address assignment by using
+		 * 0.0.0.0 as a local address, the first TCP session will
+		 * not connect because the local TCP checksum is computed
+		 * using 0.0.0.0 which will later become our real IP address
+		 * so the TCP checksum computed at the remote end will
+		 * become invalid. So we
+		 * - don't let packets with src ip addr 0 thru
+		 * - we flag TCP packets with src ip 0 as an error
+		 */
+
+		if(ip->ip_src.s_addr == INADDR_ANY)	/* -hm */
+		{
+			m_freem(m);
+			SPPP_UNLOCK(sp);
+			splx(s);
+			if(ip->ip_p == IPPROTO_TCP)
+				return(EADDRNOTAVAIL);
+			else
+				return(0);
+		}
+
+		/*
+		 * Put low delay, telnet, rlogin and ftp control packets
+		 * in front of the queue or let ALTQ take care.
+		 */
+		if (ALTQ_IS_ENABLED(&ifp->if_snd))
+			;
+		else if (_IF_QFULL(&sp->pp_fastq))
+			;
+		else if (ip->ip_tos & IPTOS_LOWDELAY)
+			ifq = &sp->pp_fastq;
+		else if (m->m_len < sizeof *ip + sizeof *tcp)
+			;
+		else if (ip->ip_p != IPPROTO_TCP)
+			;
+		else if (INTERACTIVE (ntohs (tcp->th_sport)))
+			ifq = &sp->pp_fastq;
+		else if (INTERACTIVE (ntohs (tcp->th_dport)))
+			ifq = &sp->pp_fastq;
+
+		/*
+		 * Do IP Header compression
+		 */
+		if (sp->pp_mode != IFF_CISCO && sp->pp_mode != PP_FR &&
+		    (sp->ipcp.flags & IPCP_VJ) && ip->ip_p == IPPROTO_TCP)
+			switch (sl_compress_tcp(m, ip, sp->pp_comp,
+						sp->ipcp.compress_cid)) {
+			case TYPE_COMPRESSED_TCP:
+				ipproto = PPP_VJ_COMP;
+				break;
+			case TYPE_UNCOMPRESSED_TCP:
+				ipproto = PPP_VJ_UCOMP;
+				break;
+			case TYPE_IP:
+				ipproto = PPP_IP;
+				break;
+			default:
+				m_freem(m);
+				SPPP_UNLOCK(sp);
+				splx(s);
+				return (EINVAL);
+			}
+	}
+#endif
+
+#ifdef INET6
+	if (dst->sa_family == AF_INET6) {
+		/* XXX do something tricky here? */
+	}
+#endif
+
+	if (sp->pp_mode == PP_FR) {
+		/* Add frame relay header. */
+		m = sppp_fr_header (sp, m, dst->sa_family);
+		if (! m)
+			goto nobufs;
+		goto out;
+	}
+
+	/*
+	 * Prepend general data packet PPP header. For now, IP only.
+	 */
+	M_PREPEND (m, PPP_HEADER_LEN, M_DONTWAIT);
+	if (! m) {
+nobufs:		if (debug)
+			log(LOG_DEBUG, SPP_FMT "no memory for transmit header\n",
+				SPP_ARGS(ifp));
+		++ifp->if_oerrors;
+		SPPP_UNLOCK(sp);
+		splx (s);
+		return (ENOBUFS);
+	}
+	/*
+	 * May want to check size of packet
+	 * (albeit due to the implementation it's always enough)
+	 */
+	h = mtod (m, struct ppp_header*);
+	if (sp->pp_mode == IFF_CISCO) {
+		h->address = CISCO_UNICAST;        /* unicast address */
+		h->control = 0;
+	} else {
+		h->address = PPP_ALLSTATIONS;        /* broadcast address */
+		h->control = PPP_UI;                 /* Unnumbered Info */
+	}
+
+	switch (dst->sa_family) {
+#ifdef INET
+	case AF_INET:   /* Internet Protocol */
+		if (sp->pp_mode == IFF_CISCO)
+			h->protocol = htons (ETHERTYPE_IP);
+		else {
+			/*
+			 * Don't choke with an ENETDOWN early.  It's
+			 * possible that we just started dialing out,
+			 * so don't drop the packet immediately.  If
+			 * we notice that we run out of buffer space
+			 * below, we will however remember that we are
+			 * not ready to carry IP packets, and return
+			 * ENETDOWN, as opposed to ENOBUFS.
+			 */
+			h->protocol = htons(ipproto);
+			if (sp->state[IDX_IPCP] != STATE_OPENED)
+				rv = ENETDOWN;
+		}
+		break;
+#endif
+#ifdef INET6
+	case AF_INET6:   /* Internet Protocol */
+		if (sp->pp_mode == IFF_CISCO)
+			h->protocol = htons (ETHERTYPE_IPV6);
+		else {
+			/*
+			 * Don't choke with an ENETDOWN early.  It's
+			 * possible that we just started dialing out,
+			 * so don't drop the packet immediately.  If
+			 * we notice that we run out of buffer space
+			 * below, we will however remember that we are
+			 * not ready to carry IP packets, and return
+			 * ENETDOWN, as opposed to ENOBUFS.
+			 */
+			h->protocol = htons(PPP_IPV6);
+			if (sp->state[IDX_IPV6CP] != STATE_OPENED)
+				rv = ENETDOWN;
+		}
+		break;
+#endif
+#ifdef IPX
+	case AF_IPX:     /* Novell IPX Protocol */
+		h->protocol = htons (sp->pp_mode == IFF_CISCO ?
+			ETHERTYPE_IPX : PPP_IPX);
+		break;
+#endif
+	default:
+		m_freem (m);
+		++ifp->if_oerrors;
+		SPPP_UNLOCK(sp);
+		splx (s);
+		return (EAFNOSUPPORT);
+	}
+
+	/*
+	 * Queue message on interface, and start output if interface
+	 * not yet active.
+	 */
+out:
+	if (ifq != NULL)
+		error = !(IF_HANDOFF_ADJ(ifq, m, ifp, 3));
+	else
+		IFQ_HANDOFF_ADJ(ifp, m, 3, error);
+	if (error) {
+		++ifp->if_oerrors;
+		SPPP_UNLOCK(sp);
+		splx (s);
+		return (rv? rv: ENOBUFS);
+	}
+	SPPP_UNLOCK(sp);
+	splx (s);
+	/*
+	 * Unlike in sppp_input(), we can always bump the timestamp
+	 * here since sppp_output() is only called on behalf of
+	 * network-layer traffic; control-layer traffic is handled
+	 * by sppp_cp_send().
+	 */
+	sp->pp_last_sent = time_uptime;
+	return (0);
+}
+
+void
+sppp_attach(struct ifnet *ifp)
+{
+	struct sppp *sp = IFP2SP(ifp);
+
+	/* Initialize mtx lock */
+	mtx_init(&sp->mtx, "sppp", MTX_NETWORK_LOCK, MTX_DEF | MTX_RECURSE);
+	
+	/* Initialize keepalive handler. */
+ 	callout_init(&sp->keepalive_callout, CALLOUT_MPSAFE);
+	callout_reset(&sp->keepalive_callout, hz * 10, sppp_keepalive,
+ 		    (void *)sp); 
+
+	ifp->if_mtu = PP_MTU;
+	ifp->if_flags = IFF_POINTOPOINT | IFF_MULTICAST;
+	ifp->if_output = sppp_output;
+#if 0
+	sp->pp_flags = PP_KEEPALIVE;
+#endif
+ 	ifp->if_snd.ifq_maxlen = 32;
+ 	sp->pp_fastq.ifq_maxlen = 32;
+ 	sp->pp_cpq.ifq_maxlen = 20;
+	sp->pp_loopcnt = 0;
+	sp->pp_alivecnt = 0;
+	bzero(&sp->pp_seq[0], sizeof(sp->pp_seq));
+	bzero(&sp->pp_rseq[0], sizeof(sp->pp_rseq));
+	sp->pp_phase = PHASE_DEAD;
+	sp->pp_up = sppp_pp_up;
+	sp->pp_down = sppp_pp_down;
+	if(!mtx_initialized(&sp->pp_cpq.ifq_mtx))
+		mtx_init(&sp->pp_cpq.ifq_mtx, "sppp_cpq", NULL, MTX_DEF);
+	if(!mtx_initialized(&sp->pp_fastq.ifq_mtx))
+		mtx_init(&sp->pp_fastq.ifq_mtx, "sppp_fastq", NULL, MTX_DEF);
+	sp->pp_last_recv = sp->pp_last_sent = time_uptime;
+	sp->confflags = 0;
+#ifdef INET
+	sp->confflags |= CONF_ENABLE_VJ;
+#endif
+#ifdef INET6
+	sp->confflags |= CONF_ENABLE_IPV6;
+#endif
+ 	callout_init(&sp->ifstart_callout, CALLOUT_MPSAFE);
+	sp->if_start = ifp->if_start;
+	ifp->if_start = sppp_ifstart;
+	sp->pp_comp = malloc(sizeof(struct slcompress), M_TEMP, M_WAITOK);
+	sl_compress_init(sp->pp_comp, -1);
+	sppp_lcp_init(sp);
+	sppp_ipcp_init(sp);
+	sppp_ipv6cp_init(sp);
+	sppp_pap_init(sp);
+	sppp_chap_init(sp);
+}
+
+void
+sppp_detach(struct ifnet *ifp)
+{
+	struct sppp *sp = IFP2SP(ifp);
+	int i;
+
+	KASSERT(mtx_initialized(&sp->mtx), ("sppp mutex is not initialized"));
+
+	/* Stop keepalive handler. */
+ 	if (!callout_drain(&sp->keepalive_callout))
+		callout_stop(&sp->keepalive_callout);
+
+	for (i = 0; i < IDX_COUNT; i++) {
+		if (!callout_drain(&sp->ch[i]))
+			callout_stop(&sp->ch[i]);
+	}
+	if (!callout_drain(&sp->pap_my_to_ch))
+		callout_stop(&sp->pap_my_to_ch);
+	mtx_destroy(&sp->pp_cpq.ifq_mtx);
+	mtx_destroy(&sp->pp_fastq.ifq_mtx);
+	mtx_destroy(&sp->mtx);
+}
+
+/*
+ * Flush the interface output queue.
+ */
+static void
+sppp_flush_unlocked(struct ifnet *ifp)
+{
+	struct sppp *sp = IFP2SP(ifp);
+
+	sppp_qflush ((struct ifqueue *)&SP2IFP(sp)->if_snd);
+	sppp_qflush (&sp->pp_fastq);
+	sppp_qflush (&sp->pp_cpq);
+}
+
+void
+sppp_flush(struct ifnet *ifp)
+{
+	struct sppp *sp = IFP2SP(ifp);
+
+	SPPP_LOCK(sp);
+	sppp_flush_unlocked (ifp);
+	SPPP_UNLOCK(sp);
+}
+
+/*
+ * Check if the output queue is empty.
+ */
+int
+sppp_isempty(struct ifnet *ifp)
+{
+	struct sppp *sp = IFP2SP(ifp);
+	int empty, s;
+
+	s = splimp();
+	SPPP_LOCK(sp);
+	empty = !sp->pp_fastq.ifq_head && !sp->pp_cpq.ifq_head &&
+		!SP2IFP(sp)->if_snd.ifq_head;
+	SPPP_UNLOCK(sp);
+	splx(s);
+	return (empty);
+}
+
+/*
+ * Get next packet to send.
+ */
+struct mbuf *
+sppp_dequeue(struct ifnet *ifp)
+{
+	struct sppp *sp = IFP2SP(ifp);
+	struct mbuf *m;
+	int s;
+
+	s = splimp();
+	SPPP_LOCK(sp);
+	/*
+	 * Process only the control protocol queue until we have at
+	 * least one NCP open.
+	 *
+	 * Do always serve all three queues in Cisco mode.
+	 */
+	IF_DEQUEUE(&sp->pp_cpq, m);
+	if (m == NULL &&
+	    (sppp_ncp_check(sp) || sp->pp_mode == IFF_CISCO ||
+	     sp->pp_mode == PP_FR)) {
+		IF_DEQUEUE(&sp->pp_fastq, m);
+		if (m == NULL)
+			IF_DEQUEUE (&SP2IFP(sp)->if_snd, m);
+	}
+	SPPP_UNLOCK(sp);
+	splx(s);
+	return m;
+}
+
+/*
+ * Pick the next packet, do not remove it from the queue.
+ */
+struct mbuf *
+sppp_pick(struct ifnet *ifp)
+{
+	struct sppp *sp = IFP2SP(ifp);
+	struct mbuf *m;
+	int s;
+
+	s = splimp ();
+	SPPP_LOCK(sp);
+
+	m = sp->pp_cpq.ifq_head;
+	if (m == NULL &&
+	    (sp->pp_phase == PHASE_NETWORK ||
+	     sp->pp_mode == IFF_CISCO ||
+	     sp->pp_mode == PP_FR))
+		if ((m = sp->pp_fastq.ifq_head) == NULL)
+			m = SP2IFP(sp)->if_snd.ifq_head;
+	SPPP_UNLOCK(sp);
+	splx (s);
+	return (m);
+}
+
+/*
+ * Process an ioctl request.  Called on low priority level.
+ */
+int
+sppp_ioctl(struct ifnet *ifp, IOCTL_CMD_T cmd, void *data)
+{
+	struct ifreq *ifr = (struct ifreq*) data;
+	struct sppp *sp = IFP2SP(ifp);
+	int s, rv, going_up, going_down, newmode;
+
+	s = splimp();
+	SPPP_LOCK(sp);
+	rv = 0;
+	switch (cmd) {
+	case SIOCAIFADDR:
+	case SIOCSIFDSTADDR:
+		break;
+
+	case SIOCSIFADDR:
+		/* set the interface "up" when assigning an IP address */
+		ifp->if_flags |= IFF_UP;
+		/* FALLTHROUGH */
+
+	case SIOCSIFFLAGS:
+		going_up = ifp->if_flags & IFF_UP &&
+			(ifp->if_drv_flags & IFF_DRV_RUNNING) == 0;
+		going_down = (ifp->if_flags & IFF_UP) == 0 &&
+			ifp->if_drv_flags & IFF_DRV_RUNNING;
+
+		newmode = ifp->if_flags & IFF_PASSIVE;
+		if (!newmode)
+			newmode = ifp->if_flags & IFF_AUTO;
+		if (!newmode)
+			newmode = ifp->if_flags & IFF_CISCO;
+		ifp->if_flags &= ~(IFF_PASSIVE | IFF_AUTO | IFF_CISCO);
+		ifp->if_flags |= newmode;
+
+		if (!newmode)
+			newmode = sp->pp_flags & PP_FR;
+
+		if (newmode != sp->pp_mode) {
+			going_down = 1;
+			if (!going_up)
+				going_up = ifp->if_drv_flags & IFF_DRV_RUNNING;
+		}
+
+		if (going_down) {
+			if (sp->pp_mode != IFF_CISCO &&
+			    sp->pp_mode != PP_FR)
+				lcp.Close(sp);
+			else if (sp->pp_tlf)
+				(sp->pp_tlf)(sp);
+			sppp_flush_unlocked(ifp);
+			ifp->if_drv_flags &= ~IFF_DRV_RUNNING;
+			sp->pp_mode = newmode;
+		}
+
+		if (going_up) {
+			if (sp->pp_mode != IFF_CISCO &&
+			    sp->pp_mode != PP_FR)
+				lcp.Close(sp);
+			sp->pp_mode = newmode;
+			if (sp->pp_mode == 0) {
+				ifp->if_drv_flags |= IFF_DRV_RUNNING;
+				lcp.Open(sp);
+			}
+			if ((sp->pp_mode == IFF_CISCO) ||
+			    (sp->pp_mode == PP_FR)) {
+				if (sp->pp_tls)
+					(sp->pp_tls)(sp);
+				ifp->if_drv_flags |= IFF_DRV_RUNNING;
+			}
+		}
+
+		break;
+
+#ifdef SIOCSIFMTU
+#ifndef ifr_mtu
+#define ifr_mtu ifr_metric
+#endif
+	case SIOCSIFMTU:
+		if (ifr->ifr_mtu < 128 || ifr->ifr_mtu > sp->lcp.their_mru)
+			return (EINVAL);
+		ifp->if_mtu = ifr->ifr_mtu;
+		break;
+#endif
+#ifdef SLIOCSETMTU
+	case SLIOCSETMTU:
+		if (*(short*)data < 128 || *(short*)data > sp->lcp.their_mru)
+			return (EINVAL);
+		ifp->if_mtu = *(short*)data;
+		break;
+#endif
+#ifdef SIOCGIFMTU
+	case SIOCGIFMTU:
+		ifr->ifr_mtu = ifp->if_mtu;
+		break;
+#endif
+#ifdef SLIOCGETMTU
+	case SLIOCGETMTU:
+		*(short*)data = ifp->if_mtu;
+		break;
+#endif
+	case SIOCADDMULTI:
+	case SIOCDELMULTI:
+		break;
+
+	case SIOCGIFGENERIC:
+	case SIOCSIFGENERIC:
+		rv = sppp_params(sp, cmd, data);
+		break;
+
+	default:
+		rv = ENOTTY;
+	}
+	SPPP_UNLOCK(sp);
+	splx(s);
+	return rv;
+}
+
+/*
+ * Cisco framing implementation.
+ */
+
+/*
+ * Handle incoming Cisco keepalive protocol packets.
+ */
+static void
+sppp_cisco_input(struct sppp *sp, struct mbuf *m)
+{
+	STDDCL;
+	struct cisco_packet *h;
+	u_long me, mymask;
+
+	if (m->m_pkthdr.len < CISCO_PACKET_LEN) {
+		if (debug)
+			log(LOG_DEBUG,
+			    SPP_FMT "cisco invalid packet length: %d bytes\n",
+			    SPP_ARGS(ifp), m->m_pkthdr.len);
+		return;
+	}
+	h = mtod (m, struct cisco_packet*);
+	if (debug)
+		log(LOG_DEBUG,
+		    SPP_FMT "cisco input: %d bytes "
+		    "<0x%lx 0x%lx 0x%lx 0x%x 0x%x-0x%x>\n",
+		    SPP_ARGS(ifp), m->m_pkthdr.len,
+		    (u_long)ntohl (h->type), (u_long)h->par1, (u_long)h->par2, (u_int)h->rel,
+		    (u_int)h->time0, (u_int)h->time1);
+	switch (ntohl (h->type)) {
+	default:
+		if (debug)
+			log(-1, SPP_FMT "cisco unknown packet type: 0x%lx\n",
+			       SPP_ARGS(ifp), (u_long)ntohl (h->type));
+		break;
+	case CISCO_ADDR_REPLY:
+		/* Reply on address request, ignore */
+		break;
+	case CISCO_KEEPALIVE_REQ:
+		sp->pp_alivecnt = 0;
+		sp->pp_rseq[IDX_LCP] = ntohl (h->par1);
+		if (sp->pp_seq[IDX_LCP] == sp->pp_rseq[IDX_LCP]) {
+			/* Local and remote sequence numbers are equal.
+			 * Probably, the line is in loopback mode. */
+			if (sp->pp_loopcnt >= MAXALIVECNT) {
+				printf (SPP_FMT "loopback\n",
+					SPP_ARGS(ifp));
+				sp->pp_loopcnt = 0;
+				if (ifp->if_flags & IFF_UP) {
+					if_down (ifp);
+					sppp_qflush (&sp->pp_cpq);
+				}
+			}
+			++sp->pp_loopcnt;
+
+			/* Generate new local sequence number */
+			sp->pp_seq[IDX_LCP] = random();
+			break;
+		}
+		sp->pp_loopcnt = 0;
+		if (! (ifp->if_flags & IFF_UP) &&
+		    (ifp->if_drv_flags & IFF_DRV_RUNNING)) {
+			if_up(ifp);
+			printf (SPP_FMT "up\n", SPP_ARGS(ifp));
+		}
+		break;
+	case CISCO_ADDR_REQ:
+		sppp_get_ip_addrs(sp, &me, 0, &mymask);
+		if (me != 0L)
+			sppp_cisco_send(sp, CISCO_ADDR_REPLY, me, mymask);
+		break;
+	}
+}
+
+/*
+ * Send Cisco keepalive packet.
+ */
+static void
+sppp_cisco_send(struct sppp *sp, int type, long par1, long par2)
+{
+	STDDCL;
+	struct ppp_header *h;
+	struct cisco_packet *ch;
+	struct mbuf *m;
+	struct timeval tv;
+
+	getmicrouptime(&tv);
+
+	MGETHDR (m, M_DONTWAIT, MT_DATA);
+	if (! m)
+		return;
+	m->m_pkthdr.len = m->m_len = PPP_HEADER_LEN + CISCO_PACKET_LEN;
+	m->m_pkthdr.rcvif = 0;
+
+	h = mtod (m, struct ppp_header*);
+	h->address = CISCO_MULTICAST;
+	h->control = 0;
+	h->protocol = htons (CISCO_KEEPALIVE);
+
+	ch = (struct cisco_packet*) (h + 1);
+	ch->type = htonl (type);
+	ch->par1 = htonl (par1);
+	ch->par2 = htonl (par2);
+	ch->rel = -1;
+
+	ch->time0 = htons ((u_short) (tv.tv_sec >> 16));
+	ch->time1 = htons ((u_short) tv.tv_sec);
+
+	if (debug)
+		log(LOG_DEBUG,
+		    SPP_FMT "cisco output: <0x%lx 0x%lx 0x%lx 0x%x 0x%x-0x%x>\n",
+			SPP_ARGS(ifp), (u_long)ntohl (ch->type), (u_long)ch->par1,
+			(u_long)ch->par2, (u_int)ch->rel, (u_int)ch->time0, (u_int)ch->time1);
+
+	if (! IF_HANDOFF_ADJ(&sp->pp_cpq, m, ifp, 3))
+		ifp->if_oerrors++;
+}
+
+/*
+ * PPP protocol implementation.
+ */
+
+/*
+ * Send PPP control protocol packet.
+ */
+static void
+sppp_cp_send(struct sppp *sp, u_short proto, u_char type,
+	     u_char ident, u_short len, void *data)
+{
+	STDDCL;
+	struct ppp_header *h;
+	struct lcp_header *lh;
+	struct mbuf *m;
+
+	if (len > MHLEN - PPP_HEADER_LEN - LCP_HEADER_LEN)
+		len = MHLEN - PPP_HEADER_LEN - LCP_HEADER_LEN;
+	MGETHDR (m, M_DONTWAIT, MT_DATA);
+	if (! m)
+		return;
+	m->m_pkthdr.len = m->m_len = PPP_HEADER_LEN + LCP_HEADER_LEN + len;
+	m->m_pkthdr.rcvif = 0;
+
+	h = mtod (m, struct ppp_header*);
+	h->address = PPP_ALLSTATIONS;        /* broadcast address */
+	h->control = PPP_UI;                 /* Unnumbered Info */
+	h->protocol = htons (proto);         /* Link Control Protocol */
+
+	lh = (struct lcp_header*) (h + 1);
+	lh->type = type;
+	lh->ident = ident;
+	lh->len = htons (LCP_HEADER_LEN + len);
+	if (len)
+		bcopy (data, lh+1, len);
+
+	if (debug) {
+		log(LOG_DEBUG, SPP_FMT "%s output <%s id=0x%x len=%d",
+		    SPP_ARGS(ifp),
+		    sppp_proto_name(proto),
+		    sppp_cp_type_name (lh->type), lh->ident,
+		    ntohs (lh->len));
+		sppp_print_bytes ((u_char*) (lh+1), len);
+		log(-1, ">\n");
+	}
+	if (! IF_HANDOFF_ADJ(&sp->pp_cpq, m, ifp, 3))
+		ifp->if_oerrors++;
+}
+
+/*
+ * Handle incoming PPP control protocol packets.
+ */
+static void
+sppp_cp_input(const struct cp *cp, struct sppp *sp, struct mbuf *m)
+{
+	STDDCL;
+	struct lcp_header *h;
+	int len = m->m_pkthdr.len;
+	int rv;
+	u_char *p;
+
+	if (len < 4) {
+		if (debug)
+			log(LOG_DEBUG,
+			    SPP_FMT "%s invalid packet length: %d bytes\n",
+			    SPP_ARGS(ifp), cp->name, len);
+		return;
+	}
+	h = mtod (m, struct lcp_header*);
+	if (debug) {
+		log(LOG_DEBUG,
+		    SPP_FMT "%s input(%s): <%s id=0x%x len=%d",
+		    SPP_ARGS(ifp), cp->name,
+		    sppp_state_name(sp->state[cp->protoidx]),
+		    sppp_cp_type_name (h->type), h->ident, ntohs (h->len));
+		sppp_print_bytes ((u_char*) (h+1), len-4);
+		log(-1, ">\n");
+	}
+	if (len > ntohs (h->len))
+		len = ntohs (h->len);
+	p = (u_char *)(h + 1);
+	switch (h->type) {
+	case CONF_REQ:
+		if (len < 4) {
+			if (debug)
+				log(-1, SPP_FMT "%s invalid conf-req length %d\n",
+				       SPP_ARGS(ifp), cp->name,
+				       len);
+			++ifp->if_ierrors;
+			break;
+		}
+		/* handle states where RCR doesn't get a SCA/SCN */
+		switch (sp->state[cp->protoidx]) {
+		case STATE_CLOSING:
+		case STATE_STOPPING:
+			return;
+		case STATE_CLOSED:
+			sppp_cp_send(sp, cp->proto, TERM_ACK, h->ident,
+				     0, 0);
+			return;
+		}
+		rv = (cp->RCR)(sp, h, len);
+		switch (sp->state[cp->protoidx]) {
+		case STATE_OPENED:
+			(cp->tld)(sp);
+			(cp->scr)(sp);
+			/* FALLTHROUGH */
+		case STATE_ACK_SENT:
+		case STATE_REQ_SENT:
+			/*
+			 * sppp_cp_change_state() have the side effect of
+			 * restarting the timeouts. We want to avoid that
+			 * if the state don't change, otherwise we won't
+			 * ever timeout and resend a configuration request
+			 * that got lost.
+			 */
+			if (sp->state[cp->protoidx] == (rv ? STATE_ACK_SENT:
+			    STATE_REQ_SENT))
+				break;
+			sppp_cp_change_state(cp, sp, rv?
+					     STATE_ACK_SENT: STATE_REQ_SENT);
+			break;
+		case STATE_STOPPED:
+			sp->rst_counter[cp->protoidx] = sp->lcp.max_configure;
+			(cp->scr)(sp);
+			sppp_cp_change_state(cp, sp, rv?
+					     STATE_ACK_SENT: STATE_REQ_SENT);
+			break;
+		case STATE_ACK_RCVD:
+			if (rv) {
+				sppp_cp_change_state(cp, sp, STATE_OPENED);
+				if (debug)
+					log(LOG_DEBUG, SPP_FMT "%s tlu\n",
+					    SPP_ARGS(ifp),
+					    cp->name);
+				(cp->tlu)(sp);
+			} else
+				sppp_cp_change_state(cp, sp, STATE_ACK_RCVD);
+			break;
+		default:
+			printf(SPP_FMT "%s illegal %s in state %s\n",
+			       SPP_ARGS(ifp), cp->name,
+			       sppp_cp_type_name(h->type),
+			       sppp_state_name(sp->state[cp->protoidx]));
+			++ifp->if_ierrors;
+		}
+		break;
+	case CONF_ACK:
+		if (h->ident != sp->confid[cp->protoidx]) {
+			if (debug)
+				log(-1, SPP_FMT "%s id mismatch 0x%x != 0x%x\n",
+				       SPP_ARGS(ifp), cp->name,
+				       h->ident, sp->confid[cp->protoidx]);
+			++ifp->if_ierrors;
+			break;
+		}
+		switch (sp->state[cp->protoidx]) {
+		case STATE_CLOSED:
+		case STATE_STOPPED:
+			sppp_cp_send(sp, cp->proto, TERM_ACK, h->ident, 0, 0);
+			break;
+		case STATE_CLOSING:
+		case STATE_STOPPING:
+			break;
+		case STATE_REQ_SENT:
+			sp->rst_counter[cp->protoidx] = sp->lcp.max_configure;
+			sppp_cp_change_state(cp, sp, STATE_ACK_RCVD);
+			break;
+		case STATE_OPENED:
+			(cp->tld)(sp);
+			/* FALLTHROUGH */
+		case STATE_ACK_RCVD:
+			(cp->scr)(sp);
+			sppp_cp_change_state(cp, sp, STATE_REQ_SENT);
+			break;
+		case STATE_ACK_SENT:
+			sp->rst_counter[cp->protoidx] = sp->lcp.max_configure;
+			sppp_cp_change_state(cp, sp, STATE_OPENED);
+			if (debug)
+				log(LOG_DEBUG, SPP_FMT "%s tlu\n",
+				       SPP_ARGS(ifp), cp->name);
+			(cp->tlu)(sp);
+			break;
+		default:
+			printf(SPP_FMT "%s illegal %s in state %s\n",
+			       SPP_ARGS(ifp), cp->name,
+			       sppp_cp_type_name(h->type),
+			       sppp_state_name(sp->state[cp->protoidx]));
+			++ifp->if_ierrors;
+		}
+		break;
+	case CONF_NAK:
+	case CONF_REJ:
+		if (h->ident != sp->confid[cp->protoidx]) {
+			if (debug)
+				log(-1, SPP_FMT "%s id mismatch 0x%x != 0x%x\n",
+				       SPP_ARGS(ifp), cp->name,
+				       h->ident, sp->confid[cp->protoidx]);
+			++ifp->if_ierrors;
+			break;
+		}
+		if (h->type == CONF_NAK)
+			(cp->RCN_nak)(sp, h, len);
+		else /* CONF_REJ */
+			(cp->RCN_rej)(sp, h, len);
+
+		switch (sp->state[cp->protoidx]) {
+		case STATE_CLOSED:
+		case STATE_STOPPED:
+			sppp_cp_send(sp, cp->proto, TERM_ACK, h->ident, 0, 0);
+			break;
+		case STATE_REQ_SENT:
+		case STATE_ACK_SENT:
+			sp->rst_counter[cp->protoidx] = sp->lcp.max_configure;
+			/*
+			 * Slow things down a bit if we think we might be
+			 * in loopback. Depend on the timeout to send the
+			 * next configuration request.
+			 */
+			if (sp->pp_loopcnt)
+				break;
+			(cp->scr)(sp);
+			break;
+		case STATE_OPENED:
+			(cp->tld)(sp);
+			/* FALLTHROUGH */
+		case STATE_ACK_RCVD:
+			sppp_cp_change_state(cp, sp, STATE_REQ_SENT);
+			(cp->scr)(sp);
+			break;
+		case STATE_CLOSING:
+		case STATE_STOPPING:
+			break;
+		default:
+			printf(SPP_FMT "%s illegal %s in state %s\n",
+			       SPP_ARGS(ifp), cp->name,
+			       sppp_cp_type_name(h->type),
+			       sppp_state_name(sp->state[cp->protoidx]));
+			++ifp->if_ierrors;
+		}
+		break;
+
+	case TERM_REQ:
+		switch (sp->state[cp->protoidx]) {
+		case STATE_ACK_RCVD:
+		case STATE_ACK_SENT:
+			sppp_cp_change_state(cp, sp, STATE_REQ_SENT);
+			/* FALLTHROUGH */
+		case STATE_CLOSED:
+		case STATE_STOPPED:
+		case STATE_CLOSING:
+		case STATE_STOPPING:
+		case STATE_REQ_SENT:
+		  sta:
+			/* Send Terminate-Ack packet. */
+			if (debug)
+				log(LOG_DEBUG, SPP_FMT "%s send terminate-ack\n",
+				    SPP_ARGS(ifp), cp->name);
+			sppp_cp_send(sp, cp->proto, TERM_ACK, h->ident, 0, 0);
+			break;
+		case STATE_OPENED:
+			(cp->tld)(sp);
+			sp->rst_counter[cp->protoidx] = 0;
+			sppp_cp_change_state(cp, sp, STATE_STOPPING);
+			goto sta;
+			break;
+		default:
+			printf(SPP_FMT "%s illegal %s in state %s\n",
+			       SPP_ARGS(ifp), cp->name,
+			       sppp_cp_type_name(h->type),
+			       sppp_state_name(sp->state[cp->protoidx]));
+			++ifp->if_ierrors;
+		}
+		break;
+	case TERM_ACK:
+		switch (sp->state[cp->protoidx]) {
+		case STATE_CLOSED:
+		case STATE_STOPPED:
+		case STATE_REQ_SENT:
+		case STATE_ACK_SENT:
+			break;
+		case STATE_CLOSING:
+			sppp_cp_change_state(cp, sp, STATE_CLOSED);
+			(cp->tlf)(sp);
+			break;
+		case STATE_STOPPING:
+			sppp_cp_change_state(cp, sp, STATE_STOPPED);
+			(cp->tlf)(sp);
+			break;
+		case STATE_ACK_RCVD:
+			sppp_cp_change_state(cp, sp, STATE_REQ_SENT);
+			break;
+		case STATE_OPENED:
+			(cp->tld)(sp);
+			(cp->scr)(sp);
+			sppp_cp_change_state(cp, sp, STATE_ACK_RCVD);
+			break;
+		default:
+			printf(SPP_FMT "%s illegal %s in state %s\n",
+			       SPP_ARGS(ifp), cp->name,
+			       sppp_cp_type_name(h->type),
+			       sppp_state_name(sp->state[cp->protoidx]));
+			++ifp->if_ierrors;
+		}
+		break;
+	case CODE_REJ:
+		/* XXX catastrophic rejects (RXJ-) aren't handled yet. */
+		log(LOG_INFO,
+		    SPP_FMT "%s: ignoring RXJ (%s) for proto 0x%x, "
+		    "danger will robinson\n",
+		    SPP_ARGS(ifp), cp->name,
+		    sppp_cp_type_name(h->type), ntohs(*((u_short *)p)));
+		switch (sp->state[cp->protoidx]) {
+		case STATE_CLOSED:
+		case STATE_STOPPED:
+		case STATE_REQ_SENT:
+		case STATE_ACK_SENT:
+		case STATE_CLOSING:
+		case STATE_STOPPING:
+		case STATE_OPENED:
+			break;
+		case STATE_ACK_RCVD:
+			sppp_cp_change_state(cp, sp, STATE_REQ_SENT);
+			break;
+		default:
+			printf(SPP_FMT "%s illegal %s in state %s\n",
+			       SPP_ARGS(ifp), cp->name,
+			       sppp_cp_type_name(h->type),
+			       sppp_state_name(sp->state[cp->protoidx]));
+			++ifp->if_ierrors;
+		}
+		break;
+	case PROTO_REJ:
+	    {
+		int catastrophic;
+		const struct cp *upper;
+		int i;
+		u_int16_t proto;
+
+		catastrophic = 0;
+		upper = NULL;
+		proto = ntohs(*((u_int16_t *)p));
+		for (i = 0; i < IDX_COUNT; i++) {
+			if (cps[i]->proto == proto) {
+				upper = cps[i];
+				break;
+			}
+		}
+		if (upper == NULL)
+			catastrophic++;
+
+		if (catastrophic || debug)
+			log(catastrophic? LOG_INFO: LOG_DEBUG,
+			    SPP_FMT "%s: RXJ%c (%s) for proto 0x%x (%s/%s)\n",
+			    SPP_ARGS(ifp), cp->name, catastrophic ? '-' : '+',
+			    sppp_cp_type_name(h->type), proto,
+			    upper ? upper->name : "unknown",
+			    upper ? sppp_state_name(sp->state[upper->protoidx]) : "?");
+
+		/*
+		 * if we got RXJ+ against conf-req, the peer does not implement
+		 * this particular protocol type.  terminate the protocol.
+		 */
+		if (upper && !catastrophic) {
+			if (sp->state[upper->protoidx] == STATE_REQ_SENT) {
+				upper->Close(sp);
+				break;
+			}
+		}
+
+		/* XXX catastrophic rejects (RXJ-) aren't handled yet. */
+		switch (sp->state[cp->protoidx]) {
+		case STATE_CLOSED:
+		case STATE_STOPPED:
+		case STATE_REQ_SENT:
+		case STATE_ACK_SENT:
+		case STATE_CLOSING:
+		case STATE_STOPPING:
+		case STATE_OPENED:
+			break;
+		case STATE_ACK_RCVD:
+			sppp_cp_change_state(cp, sp, STATE_REQ_SENT);
+			break;
+		default:
+			printf(SPP_FMT "%s illegal %s in state %s\n",
+			       SPP_ARGS(ifp), cp->name,
+			       sppp_cp_type_name(h->type),
+			       sppp_state_name(sp->state[cp->protoidx]));
+			++ifp->if_ierrors;
+		}
+		break;
+	    }
+	case DISC_REQ:
+		if (cp->proto != PPP_LCP)
+			goto illegal;
+		/* Discard the packet. */
+		break;
+	case ECHO_REQ:
+		if (cp->proto != PPP_LCP)
+			goto illegal;
+		if (sp->state[cp->protoidx] != STATE_OPENED) {
+			if (debug)
+				log(-1, SPP_FMT "lcp echo req but lcp closed\n",
+				       SPP_ARGS(ifp));
+			++ifp->if_ierrors;
+			break;
+		}
+		if (len < 8) {
+			if (debug)
+				log(-1, SPP_FMT "invalid lcp echo request "
+				       "packet length: %d bytes\n",
+				       SPP_ARGS(ifp), len);
+			break;
+		}
+		if ((sp->lcp.opts & (1 << LCP_OPT_MAGIC)) &&
+		    ntohl (*(long*)(h+1)) == sp->lcp.magic) {
+			/* Line loopback mode detected. */
+			printf(SPP_FMT "loopback\n", SPP_ARGS(ifp));
+			sp->pp_loopcnt = MAXALIVECNT * 5;
+			if_down (ifp);
+			sppp_qflush (&sp->pp_cpq);
+
+			/* Shut down the PPP link. */
+			/* XXX */
+			lcp.Down(sp);
+			lcp.Up(sp);
+			break;
+		}
+		*(long*)(h+1) = htonl (sp->lcp.magic);
+		if (debug)
+			log(-1, SPP_FMT "got lcp echo req, sending echo rep\n",
+			       SPP_ARGS(ifp));
+		sppp_cp_send (sp, PPP_LCP, ECHO_REPLY, h->ident, len-4, h+1);
+		break;
+	case ECHO_REPLY:
+		if (cp->proto != PPP_LCP)
+			goto illegal;
+		if (h->ident != sp->lcp.echoid) {
+			++ifp->if_ierrors;
+			break;
+		}
+		if (len < 8) {
+			if (debug)
+				log(-1, SPP_FMT "lcp invalid echo reply "
+				       "packet length: %d bytes\n",
+				       SPP_ARGS(ifp), len);
+			break;
+		}
+		if (debug)
+			log(-1, SPP_FMT "lcp got echo rep\n",
+			       SPP_ARGS(ifp));
+		if (!(sp->lcp.opts & (1 << LCP_OPT_MAGIC)) ||
+		    ntohl (*(long*)(h+1)) != sp->lcp.magic)
+			sp->pp_alivecnt = 0;
+		break;
+	default:
+		/* Unknown packet type -- send Code-Reject packet. */
+	  illegal:
+		if (debug)
+			log(-1, SPP_FMT "%s send code-rej for 0x%x\n",
+			       SPP_ARGS(ifp), cp->name, h->type);
+		sppp_cp_send(sp, cp->proto, CODE_REJ,
+			     ++sp->pp_seq[cp->protoidx], m->m_pkthdr.len, h);
+		++ifp->if_ierrors;
+	}
+}
+
+
+/*
+ * The generic part of all Up/Down/Open/Close/TO event handlers.
+ * Basically, the state transition handling in the automaton.
+ */
+static void
+sppp_up_event(const struct cp *cp, struct sppp *sp)
+{
+	STDDCL;
+
+	if (debug)
+		log(LOG_DEBUG, SPP_FMT "%s up(%s)\n",
+		    SPP_ARGS(ifp), cp->name,
+		    sppp_state_name(sp->state[cp->protoidx]));
+
+	switch (sp->state[cp->protoidx]) {
+	case STATE_INITIAL:
+		sppp_cp_change_state(cp, sp, STATE_CLOSED);
+		break;
+	case STATE_STARTING:
+		sp->rst_counter[cp->protoidx] = sp->lcp.max_configure;
+		(cp->scr)(sp);
+		sppp_cp_change_state(cp, sp, STATE_REQ_SENT);
+		break;
+	default:
+		printf(SPP_FMT "%s illegal up in state %s\n",
+		       SPP_ARGS(ifp), cp->name,
+		       sppp_state_name(sp->state[cp->protoidx]));
+	}
+}
+
+static void
+sppp_down_event(const struct cp *cp, struct sppp *sp)
+{
+	STDDCL;
+
+	if (debug)
+		log(LOG_DEBUG, SPP_FMT "%s down(%s)\n",
+		    SPP_ARGS(ifp), cp->name,
+		    sppp_state_name(sp->state[cp->protoidx]));
+
+	switch (sp->state[cp->protoidx]) {
+	case STATE_CLOSED:
+	case STATE_CLOSING:
+		sppp_cp_change_state(cp, sp, STATE_INITIAL);
+		break;
+	case STATE_STOPPED:
+		sppp_cp_change_state(cp, sp, STATE_STARTING);
+		(cp->tls)(sp);
+		break;
+	case STATE_STOPPING:
+	case STATE_REQ_SENT:
+	case STATE_ACK_RCVD:
+	case STATE_ACK_SENT:
+		sppp_cp_change_state(cp, sp, STATE_STARTING);
+		break;
+	case STATE_OPENED:
+		(cp->tld)(sp);
+		sppp_cp_change_state(cp, sp, STATE_STARTING);
+		break;
+	default:
+		printf(SPP_FMT "%s illegal down in state %s\n",
+		       SPP_ARGS(ifp), cp->name,
+		       sppp_state_name(sp->state[cp->protoidx]));
+	}
+}
+
+
+static void
+sppp_open_event(const struct cp *cp, struct sppp *sp)
+{
+	STDDCL;
+
+	if (debug)
+		log(LOG_DEBUG, SPP_FMT "%s open(%s)\n",
+		    SPP_ARGS(ifp), cp->name,
+		    sppp_state_name(sp->state[cp->protoidx]));
+
+	switch (sp->state[cp->protoidx]) {
+	case STATE_INITIAL:
+		sppp_cp_change_state(cp, sp, STATE_STARTING);
+		(cp->tls)(sp);
+		break;
+	case STATE_STARTING:
+		break;
+	case STATE_CLOSED:
+		sp->rst_counter[cp->protoidx] = sp->lcp.max_configure;
+		(cp->scr)(sp);
+		sppp_cp_change_state(cp, sp, STATE_REQ_SENT);
+		break;
+	case STATE_STOPPED:
+		/*
+		 * Try escaping stopped state.  This seems to bite
+		 * people occasionally, in particular for IPCP,
+		 * presumably following previous IPCP negotiation
+		 * aborts.  Somehow, we must have missed a Down event
+		 * which would have caused a transition into starting
+		 * state, so as a bandaid we force the Down event now.
+		 * This effectively implements (something like the)
+		 * `restart' option mentioned in the state transition
+		 * table of RFC 1661.
+		 */
+		sppp_cp_change_state(cp, sp, STATE_STARTING);
+		(cp->tls)(sp);
+		break;
+	case STATE_STOPPING:
+	case STATE_REQ_SENT:
+	case STATE_ACK_RCVD:
+	case STATE_ACK_SENT:
+	case STATE_OPENED:
+		break;
+	case STATE_CLOSING:
+		sppp_cp_change_state(cp, sp, STATE_STOPPING);
+		break;
+	}
+}
+
+
+static void
+sppp_close_event(const struct cp *cp, struct sppp *sp)
+{
+	STDDCL;
+
+	if (debug)
+		log(LOG_DEBUG, SPP_FMT "%s close(%s)\n",
+		    SPP_ARGS(ifp), cp->name,
+		    sppp_state_name(sp->state[cp->protoidx]));
+
+	switch (sp->state[cp->protoidx]) {
+	case STATE_INITIAL:
+	case STATE_CLOSED:
+	case STATE_CLOSING:
+		break;
+	case STATE_STARTING:
+		sppp_cp_change_state(cp, sp, STATE_INITIAL);
+		(cp->tlf)(sp);
+		break;
+	case STATE_STOPPED:
+		sppp_cp_change_state(cp, sp, STATE_CLOSED);
+		break;
+	case STATE_STOPPING:
+		sppp_cp_change_state(cp, sp, STATE_CLOSING);
+		break;
+	case STATE_OPENED:
+		(cp->tld)(sp);
+		/* FALLTHROUGH */
+	case STATE_REQ_SENT:
+	case STATE_ACK_RCVD:
+	case STATE_ACK_SENT:
+		sp->rst_counter[cp->protoidx] = sp->lcp.max_terminate;
+		sppp_cp_send(sp, cp->proto, TERM_REQ,
+			     ++sp->pp_seq[cp->protoidx], 0, 0);
+		sppp_cp_change_state(cp, sp, STATE_CLOSING);
+		break;
+	}
+}
+
+static void
+sppp_to_event(const struct cp *cp, struct sppp *sp)
+{
+	STDDCL;
+	int s;
+
+	s = splimp();
+	SPPP_LOCK(sp);
+	if (debug)
+		log(LOG_DEBUG, SPP_FMT "%s TO(%s) rst_counter = %d\n",
+		    SPP_ARGS(ifp), cp->name,
+		    sppp_state_name(sp->state[cp->protoidx]),
+		    sp->rst_counter[cp->protoidx]);
+
+	if (--sp->rst_counter[cp->protoidx] < 0)
+		/* TO- event */
+		switch (sp->state[cp->protoidx]) {
+		case STATE_CLOSING:
+			sppp_cp_change_state(cp, sp, STATE_CLOSED);
+			(cp->tlf)(sp);
+			break;
+		case STATE_STOPPING:
+			sppp_cp_change_state(cp, sp, STATE_STOPPED);
+			(cp->tlf)(sp);
+			break;
+		case STATE_REQ_SENT:
+		case STATE_ACK_RCVD:
+		case STATE_ACK_SENT:
+			sppp_cp_change_state(cp, sp, STATE_STOPPED);
+			(cp->tlf)(sp);
+			break;
+		}
+	else
+		/* TO+ event */
+		switch (sp->state[cp->protoidx]) {
+		case STATE_CLOSING:
+		case STATE_STOPPING:
+			sppp_cp_send(sp, cp->proto, TERM_REQ,
+				     ++sp->pp_seq[cp->protoidx], 0, 0);
+			callout_reset(&sp->ch[cp->protoidx], sp->lcp.timeout,
+				      cp->TO, (void *)sp);
+			break;
+		case STATE_REQ_SENT:
+		case STATE_ACK_RCVD:
+			(cp->scr)(sp);
+			/* sppp_cp_change_state() will restart the timer */
+			sppp_cp_change_state(cp, sp, STATE_REQ_SENT);
+			break;
+		case STATE_ACK_SENT:
+			(cp->scr)(sp);
+			callout_reset(&sp->ch[cp->protoidx], sp->lcp.timeout,
+				      cp->TO, (void *)sp);
+			break;
+		}
+
+	SPPP_UNLOCK(sp);
+	splx(s);
+}
+
+/*
+ * Change the state of a control protocol in the state automaton.
+ * Takes care of starting/stopping the restart timer.
+ */
+static void
+sppp_cp_change_state(const struct cp *cp, struct sppp *sp, int newstate)
+{
+	sp->state[cp->protoidx] = newstate;
+
+	callout_stop (&sp->ch[cp->protoidx]);
+
+	switch (newstate) {
+	case STATE_INITIAL:
+	case STATE_STARTING:
+	case STATE_CLOSED:
+	case STATE_STOPPED:
+	case STATE_OPENED:
+		break;
+	case STATE_CLOSING:
+	case STATE_STOPPING:
+	case STATE_REQ_SENT:
+	case STATE_ACK_RCVD:
+	case STATE_ACK_SENT:
+		callout_reset(&sp->ch[cp->protoidx], sp->lcp.timeout,
+			      cp->TO, (void *)sp);
+		break;
+	}
+}
+
+/*
+ *--------------------------------------------------------------------------*
+ *                                                                          *
+ *                         The LCP implementation.                          *
+ *                                                                          *
+ *--------------------------------------------------------------------------*
+ */
+static void
+sppp_pp_up(struct sppp *sp)
+{
+	SPPP_LOCK(sp);
+	lcp.Up(sp);
+	SPPP_UNLOCK(sp);
+}
+
+static void
+sppp_pp_down(struct sppp *sp)
+{
+	SPPP_LOCK(sp);
+	lcp.Down(sp);
+	SPPP_UNLOCK(sp);
+}
+
+static void
+sppp_lcp_init(struct sppp *sp)
+{
+	sp->lcp.opts = (1 << LCP_OPT_MAGIC);
+	sp->lcp.magic = 0;
+	sp->state[IDX_LCP] = STATE_INITIAL;
+	sp->fail_counter[IDX_LCP] = 0;
+	sp->pp_seq[IDX_LCP] = 0;
+	sp->pp_rseq[IDX_LCP] = 0;
+	sp->lcp.protos = 0;
+	sp->lcp.mru = sp->lcp.their_mru = PP_MTU;
+
+	/* Note that these values are  relevant for all control protocols */
+	sp->lcp.timeout = 3 * hz;
+	sp->lcp.max_terminate = 2;
+	sp->lcp.max_configure = 10;
+	sp->lcp.max_failure = 10;
+ 	callout_init(&sp->ch[IDX_LCP], CALLOUT_MPSAFE);
+}
+
+static void
+sppp_lcp_up(struct sppp *sp)
+{
+	STDDCL;
+
+	sp->pp_alivecnt = 0;
+	sp->lcp.opts = (1 << LCP_OPT_MAGIC);
+	sp->lcp.magic = 0;
+	sp->lcp.protos = 0;
+	sp->lcp.mru = sp->lcp.their_mru = PP_MTU;
+	/*
+	 * If we are authenticator, negotiate LCP_AUTH
+	 */
+	if (sp->hisauth.proto != 0)
+		sp->lcp.opts |= (1 << LCP_OPT_AUTH_PROTO);
+	else
+		sp->lcp.opts &= ~(1 << LCP_OPT_AUTH_PROTO);
+	sp->pp_flags &= ~PP_NEEDAUTH;
+	/*
+	 * If this interface is passive or dial-on-demand, and we are
+	 * still in Initial state, it means we've got an incoming
+	 * call.  Activate the interface.
+	 */
+	if ((ifp->if_flags & (IFF_AUTO | IFF_PASSIVE)) != 0) {
+		if (debug)
+			log(LOG_DEBUG,
+			    SPP_FMT "Up event", SPP_ARGS(ifp));
+		ifp->if_drv_flags |= IFF_DRV_RUNNING;
+		if (sp->state[IDX_LCP] == STATE_INITIAL) {
+			if (debug)
+				log(-1, "(incoming call)\n");
+			sp->pp_flags |= PP_CALLIN;
+			lcp.Open(sp);
+		} else if (debug)
+			log(-1, "\n");
+	} else if ((ifp->if_flags & (IFF_AUTO | IFF_PASSIVE)) == 0 &&
+		   (sp->state[IDX_LCP] == STATE_INITIAL)) {
+		ifp->if_drv_flags |= IFF_DRV_RUNNING;
+		lcp.Open(sp);
+	}
+
+	sppp_up_event(&lcp, sp);
+}
+
+static void
+sppp_lcp_down(struct sppp *sp)
+{
+	STDDCL;
+
+	sppp_down_event(&lcp, sp);
+
+	/*
+	 * If this is neither a dial-on-demand nor a passive
+	 * interface, simulate an ``ifconfig down'' action, so the
+	 * administrator can force a redial by another ``ifconfig
+	 * up''.  XXX For leased line operation, should we immediately
+	 * try to reopen the connection here?
+	 */
+	if ((ifp->if_flags & (IFF_AUTO | IFF_PASSIVE)) == 0) {
+		log(LOG_INFO,
+		    SPP_FMT "Down event, taking interface down.\n",
+		    SPP_ARGS(ifp));
+		if_down(ifp);
+	} else {
+		if (debug)
+			log(LOG_DEBUG,
+			    SPP_FMT "Down event (carrier loss)\n",
+			    SPP_ARGS(ifp));
+		sp->pp_flags &= ~PP_CALLIN;
+		if (sp->state[IDX_LCP] != STATE_INITIAL)
+			lcp.Close(sp);
+		ifp->if_drv_flags &= ~IFF_DRV_RUNNING;
+	}
+}
+
+static void
+sppp_lcp_open(struct sppp *sp)
+{
+	sppp_open_event(&lcp, sp);
+}
+
+static void
+sppp_lcp_close(struct sppp *sp)
+{
+	sppp_close_event(&lcp, sp);
+}
+
+static void
+sppp_lcp_TO(void *cookie)
+{
+	sppp_to_event(&lcp, (struct sppp *)cookie);
+}
+
+/*
+ * Analyze a configure request.  Return true if it was agreeable, and
+ * caused action sca, false if it has been rejected or nak'ed, and
+ * caused action scn.  (The return value is used to make the state
+ * transition decision in the state automaton.)
+ */
+static int
+sppp_lcp_RCR(struct sppp *sp, struct lcp_header *h, int len)
+{
+	STDDCL;
+	u_char *buf, *r, *p;
+	int origlen, rlen;
+	u_long nmagic;
+	u_short authproto;
+
+	len -= 4;
+	origlen = len;
+	buf = r = malloc (len, M_TEMP, M_NOWAIT);
+	if (! buf)
+		return (0);
+
+	if (debug)
+		log(LOG_DEBUG, SPP_FMT "lcp parse opts: ",
+		    SPP_ARGS(ifp));
+
+	/* pass 1: check for things that need to be rejected */
+	p = (void*) (h+1);
+	for (rlen=0; len >= 2 && p[1] >= 2 && len >= p[1];
+	    len-=p[1], p+=p[1]) {
+		if (debug)
+			log(-1, " %s ", sppp_lcp_opt_name(*p));
+		switch (*p) {
+		case LCP_OPT_MAGIC:
+			/* Magic number. */
+			if (len >= 6 && p[1] == 6)
+				continue;
+			if (debug)
+				log(-1, "[invalid] ");
+			break;
+		case LCP_OPT_ASYNC_MAP:
+			/* Async control character map. */
+			if (len >= 6 && p[1] == 6)
+				continue;
+			if (debug)
+				log(-1, "[invalid] ");
+			break;
+		case LCP_OPT_MRU:
+			/* Maximum receive unit. */
+			if (len >= 4 && p[1] == 4)
+				continue;
+			if (debug)
+				log(-1, "[invalid] ");
+			break;
+		case LCP_OPT_AUTH_PROTO:
+			if (len < 4) {
+				if (debug)
+					log(-1, "[invalid] ");
+				break;
+			}
+			authproto = (p[2] << 8) + p[3];
+			if (authproto == PPP_CHAP && p[1] != 5) {
+				if (debug)
+					log(-1, "[invalid chap len] ");
+				break;
+			}
+			if (sp->myauth.proto == 0) {
+				/* we are not configured to do auth */
+				if (debug)
+					log(-1, "[not configured] ");
+				break;
+			}
+			/*
+			 * Remote want us to authenticate, remember this,
+			 * so we stay in PHASE_AUTHENTICATE after LCP got
+			 * up.
+			 */
+			sp->pp_flags |= PP_NEEDAUTH;
+			continue;
+		default:
+			/* Others not supported. */
+			if (debug)
+				log(-1, "[rej] ");
+			break;
+		}
+		/* Add the option to rejected list. */
+		bcopy (p, r, p[1]);
+		r += p[1];
+		rlen += p[1];
+	}
+	if (rlen) {
+		if (debug)
+			log(-1, " send conf-rej\n");
+		sppp_cp_send (sp, PPP_LCP, CONF_REJ, h->ident, rlen, buf);
+		return 0;
+	} else if (debug)
+		log(-1, "\n");
+
+	/*
+	 * pass 2: check for option values that are unacceptable and
+	 * thus require to be nak'ed.
+	 */
+	if (debug)
+		log(LOG_DEBUG, SPP_FMT "lcp parse opt values: ",
+		    SPP_ARGS(ifp));
+
+	p = (void*) (h+1);
+	len = origlen;
+	for (rlen=0; len >= 2 && p[1] >= 2 && len >= p[1];
+	    len-=p[1], p+=p[1]) {
+		if (debug)
+			log(-1, " %s ", sppp_lcp_opt_name(*p));
+		switch (*p) {
+		case LCP_OPT_MAGIC:
+			/* Magic number -- extract. */
+			nmagic = (u_long)p[2] << 24 |
+				(u_long)p[3] << 16 | p[4] << 8 | p[5];
+			if (nmagic != sp->lcp.magic) {
+				sp->pp_loopcnt = 0;
+				if (debug)
+					log(-1, "0x%lx ", nmagic);
+				continue;
+			}
+			if (debug && sp->pp_loopcnt < MAXALIVECNT*5)
+				log(-1, "[glitch] ");
+			++sp->pp_loopcnt;
+			/*
+			 * We negate our magic here, and NAK it.  If
+			 * we see it later in an NAK packet, we
+			 * suggest a new one.
+			 */
+			nmagic = ~sp->lcp.magic;
+			/* Gonna NAK it. */
+			p[2] = nmagic >> 24;
+			p[3] = nmagic >> 16;
+			p[4] = nmagic >> 8;
+			p[5] = nmagic;
+			break;
+
+		case LCP_OPT_ASYNC_MAP:
+			/*
+			 * Async control character map -- just ignore it.
+			 *
+			 * Quote from RFC 1662, chapter 6:
+			 * To enable this functionality, synchronous PPP
+			 * implementations MUST always respond to the
+			 * Async-Control-Character-Map Configuration
+			 * Option with the LCP Configure-Ack.  However,
+			 * acceptance of the Configuration Option does
+			 * not imply that the synchronous implementation
+			 * will do any ACCM mapping.  Instead, all such
+			 * octet mapping will be performed by the
+			 * asynchronous-to-synchronous converter.
+			 */
+			continue;
+
+		case LCP_OPT_MRU:
+			/*
+			 * Maximum receive unit.  Always agreeable,
+			 * but ignored by now.
+			 */
+			sp->lcp.their_mru = p[2] * 256 + p[3];
+			if (debug)
+				log(-1, "%lu ", sp->lcp.their_mru);
+			continue;
+
+		case LCP_OPT_AUTH_PROTO:
+			authproto = (p[2] << 8) + p[3];
+			if (sp->myauth.proto != authproto) {
+				/* not agreed, nak */
+				if (debug)
+					log(-1, "[mine %s != his %s] ",
+					       sppp_proto_name(sp->hisauth.proto),
+					       sppp_proto_name(authproto));
+				p[2] = sp->myauth.proto >> 8;
+				p[3] = sp->myauth.proto;
+				break;
+			}
+			if (authproto == PPP_CHAP && p[4] != CHAP_MD5) {
+				if (debug)
+					log(-1, "[chap not MD5] ");
+				p[4] = CHAP_MD5;
+				break;
+			}
+			continue;
+		}
+		/* Add the option to nak'ed list. */
+		bcopy (p, r, p[1]);
+		r += p[1];
+		rlen += p[1];
+	}
+	if (rlen) {
+		/*
+		 * Local and remote magics equal -- loopback?
+		 */
+		if (sp->pp_loopcnt >= MAXALIVECNT*5) {
+			if (sp->pp_loopcnt == MAXALIVECNT*5)
+				printf (SPP_FMT "loopback\n",
+					SPP_ARGS(ifp));
+			if (ifp->if_flags & IFF_UP) {
+				if_down(ifp);
+				sppp_qflush(&sp->pp_cpq);
+				/* XXX ? */
+				lcp.Down(sp);
+				lcp.Up(sp);
+			}
+		} else if (!sp->pp_loopcnt &&
+			   ++sp->fail_counter[IDX_LCP] >= sp->lcp.max_failure) {
+			if (debug)
+				log(-1, " max_failure (%d) exceeded, "
+				       "send conf-rej\n",
+				       sp->lcp.max_failure);
+			sppp_cp_send(sp, PPP_LCP, CONF_REJ, h->ident, rlen, buf);
+		} else {
+			if (debug)
+				log(-1, " send conf-nak\n");
+			sppp_cp_send (sp, PPP_LCP, CONF_NAK, h->ident, rlen, buf);
+		}
+	} else {
+		if (debug)
+			log(-1, " send conf-ack\n");
+		sp->fail_counter[IDX_LCP] = 0;
+		sp->pp_loopcnt = 0;
+		sppp_cp_send (sp, PPP_LCP, CONF_ACK,
+			      h->ident, origlen, h+1);
+	}
+
+	free (buf, M_TEMP);
+	return (rlen == 0);
+}
+
+/*
+ * Analyze the LCP Configure-Reject option list, and adjust our
+ * negotiation.
+ */
+static void
+sppp_lcp_RCN_rej(struct sppp *sp, struct lcp_header *h, int len)
+{
+	STDDCL;
+	u_char *buf, *p;
+
+	len -= 4;
+	buf = malloc (len, M_TEMP, M_NOWAIT);
+	if (!buf)
+		return;
+
+	if (debug)
+		log(LOG_DEBUG, SPP_FMT "lcp rej opts: ",
+		    SPP_ARGS(ifp));
+
+	p = (void*) (h+1);
+	for (; len >= 2 && p[1] >= 2 && len >= p[1];
+	    len -= p[1], p += p[1]) {
+		if (debug)
+			log(-1, " %s ", sppp_lcp_opt_name(*p));
+		switch (*p) {
+		case LCP_OPT_MAGIC:
+			/* Magic number -- can't use it, use 0 */
+			sp->lcp.opts &= ~(1 << LCP_OPT_MAGIC);
+			sp->lcp.magic = 0;
+			break;
+		case LCP_OPT_MRU:
+			/*
+			 * Should not be rejected anyway, since we only
+			 * negotiate a MRU if explicitly requested by
+			 * peer.
+			 */
+			sp->lcp.opts &= ~(1 << LCP_OPT_MRU);
+			break;
+		case LCP_OPT_AUTH_PROTO:
+			/*
+			 * Peer doesn't want to authenticate himself,
+			 * deny unless this is a dialout call, and
+			 * AUTHFLAG_NOCALLOUT is set.
+			 */
+			if ((sp->pp_flags & PP_CALLIN) == 0 &&
+			    (sp->hisauth.flags & AUTHFLAG_NOCALLOUT) != 0) {
+				if (debug)
+					log(-1, "[don't insist on auth "
+					       "for callout]");
+				sp->lcp.opts &= ~(1 << LCP_OPT_AUTH_PROTO);
+				break;
+			}
+			if (debug)
+				log(-1, "[access denied]\n");
+			lcp.Close(sp);
+			break;
+		}
+	}
+	if (debug)
+		log(-1, "\n");
+	free (buf, M_TEMP);
+	return;
+}
+
+/*
+ * Analyze the LCP Configure-NAK option list, and adjust our
+ * negotiation.
+ */
+static void
+sppp_lcp_RCN_nak(struct sppp *sp, struct lcp_header *h, int len)
+{
+	STDDCL;
+	u_char *buf, *p;
+	u_long magic;
+
+	len -= 4;
+	buf = malloc (len, M_TEMP, M_NOWAIT);
+	if (!buf)
+		return;
+
+	if (debug)
+		log(LOG_DEBUG, SPP_FMT "lcp nak opts: ",
+		    SPP_ARGS(ifp));
+
+	p = (void*) (h+1);
+	for (; len >= 2 && p[1] >= 2 && len >= p[1];
+	    len -= p[1], p += p[1]) {
+		if (debug)
+			log(-1, " %s ", sppp_lcp_opt_name(*p));
+		switch (*p) {
+		case LCP_OPT_MAGIC:
+			/* Magic number -- renegotiate */
+			if ((sp->lcp.opts & (1 << LCP_OPT_MAGIC)) &&
+			    len >= 6 && p[1] == 6) {
+				magic = (u_long)p[2] << 24 |
+					(u_long)p[3] << 16 | p[4] << 8 | p[5];
+				/*
+				 * If the remote magic is our negated one,
+				 * this looks like a loopback problem.
+				 * Suggest a new magic to make sure.
+				 */
+				if (magic == ~sp->lcp.magic) {
+					if (debug)
+						log(-1, "magic glitch ");
+					sp->lcp.magic = random();
+				} else {
+					sp->lcp.magic = magic;
+					if (debug)
+						log(-1, "%lu ", magic);
+				}
+			}
+			break;
+		case LCP_OPT_MRU:
+			/*
+			 * Peer wants to advise us to negotiate an MRU.
+			 * Agree on it if it's reasonable, or use
+			 * default otherwise.
+			 */
+			if (len >= 4 && p[1] == 4) {
+				u_int mru = p[2] * 256 + p[3];
+				if (debug)
+					log(-1, "%d ", mru);
+				if (mru < PP_MTU || mru > PP_MAX_MRU)
+					mru = PP_MTU;
+				sp->lcp.mru = mru;
+				sp->lcp.opts |= (1 << LCP_OPT_MRU);
+			}
+			break;
+		case LCP_OPT_AUTH_PROTO:
+			/*
+			 * Peer doesn't like our authentication method,
+			 * deny.
+			 */
+			if (debug)
+				log(-1, "[access denied]\n");
+			lcp.Close(sp);
+			break;
+		}
+	}
+	if (debug)
+		log(-1, "\n");
+	free (buf, M_TEMP);
+	return;
+}
+
+static void
+sppp_lcp_tlu(struct sppp *sp)
+{
+	STDDCL;
+	int i;
+	u_long mask;
+
+	/* XXX ? */
+	if (! (ifp->if_flags & IFF_UP) &&
+	    (ifp->if_drv_flags & IFF_DRV_RUNNING)) {
+		/* Coming out of loopback mode. */
+		if_up(ifp);
+		printf (SPP_FMT "up\n", SPP_ARGS(ifp));
+	}
+
+	for (i = 0; i < IDX_COUNT; i++)
+		if ((cps[i])->flags & CP_QUAL)
+			(cps[i])->Open(sp);
+
+	if ((sp->lcp.opts & (1 << LCP_OPT_AUTH_PROTO)) != 0 ||
+	    (sp->pp_flags & PP_NEEDAUTH) != 0)
+		sp->pp_phase = PHASE_AUTHENTICATE;
+	else
+		sp->pp_phase = PHASE_NETWORK;
+
+	if (debug)
+		log(LOG_DEBUG, SPP_FMT "phase %s\n", SPP_ARGS(ifp),
+		    sppp_phase_name(sp->pp_phase));
+
+	/*
+	 * Open all authentication protocols.  This is even required
+	 * if we already proceeded to network phase, since it might be
+	 * that remote wants us to authenticate, so we might have to
+	 * send a PAP request.  Undesired authentication protocols
+	 * don't do anything when they get an Open event.
+	 */
+	for (i = 0; i < IDX_COUNT; i++)
+		if ((cps[i])->flags & CP_AUTH)
+			(cps[i])->Open(sp);
+
+	if (sp->pp_phase == PHASE_NETWORK) {
+		/* Notify all NCPs. */
+		for (i = 0; i < IDX_COUNT; i++)
+			if (((cps[i])->flags & CP_NCP) &&
+			    /*
+			     * XXX
+			     * Hack to administratively disable IPv6 if
+			     * not desired.  Perhaps we should have another
+			     * flag for this, but right now, we can make
+			     * all struct cp's read/only.
+			     */
+			    (cps[i] != &ipv6cp ||
+			     (sp->confflags & CONF_ENABLE_IPV6)))
+				(cps[i])->Open(sp);
+	}
+
+	/* Send Up events to all started protos. */
+	for (i = 0, mask = 1; i < IDX_COUNT; i++, mask <<= 1)
+		if ((sp->lcp.protos & mask) && ((cps[i])->flags & CP_LCP) == 0)
+			(cps[i])->Up(sp);
+
+	/* notify low-level driver of state change */
+	if (sp->pp_chg)
+		sp->pp_chg(sp, (int)sp->pp_phase);
+	
+	if (sp->pp_phase == PHASE_NETWORK)
+		/* if no NCP is starting, close down */
+		sppp_lcp_check_and_close(sp);
+}
+
+static void
+sppp_lcp_tld(struct sppp *sp)
+{
+	STDDCL;
+	int i;
+	u_long mask;
+
+	sp->pp_phase = PHASE_TERMINATE;
+
+	if (debug)
+		log(LOG_DEBUG, SPP_FMT "phase %s\n", SPP_ARGS(ifp),
+		    sppp_phase_name(sp->pp_phase));
+
+	/*
+	 * Take upper layers down.  We send the Down event first and
+	 * the Close second to prevent the upper layers from sending
+	 * ``a flurry of terminate-request packets'', as the RFC
+	 * describes it.
+	 */
+	for (i = 0, mask = 1; i < IDX_COUNT; i++, mask <<= 1)
+		if ((sp->lcp.protos & mask) && ((cps[i])->flags & CP_LCP) == 0) {
+			(cps[i])->Down(sp);
+			(cps[i])->Close(sp);
+		}
+}
+
+static void
+sppp_lcp_tls(struct sppp *sp)
+{
+	STDDCL;
+
+	sp->pp_phase = PHASE_ESTABLISH;
+
+	if (debug)
+		log(LOG_DEBUG, SPP_FMT "phase %s\n", SPP_ARGS(ifp),
+		    sppp_phase_name(sp->pp_phase));
+
+	/* Notify lower layer if desired. */
+	if (sp->pp_tls)
+		(sp->pp_tls)(sp);
+	else
+		(sp->pp_up)(sp);
+}
+
+static void
+sppp_lcp_tlf(struct sppp *sp)
+{
+	STDDCL;
+
+	sp->pp_phase = PHASE_DEAD;
+	if (debug)
+		log(LOG_DEBUG, SPP_FMT "phase %s\n", SPP_ARGS(ifp),
+		    sppp_phase_name(sp->pp_phase));
+
+	/* Notify lower layer if desired. */
+	if (sp->pp_tlf)
+		(sp->pp_tlf)(sp);
+	else
+		(sp->pp_down)(sp);
+}
+
+static void
+sppp_lcp_scr(struct sppp *sp)
+{
+	char opt[6 /* magicnum */ + 4 /* mru */ + 5 /* chap */];
+	int i = 0;
+	u_short authproto;
+
+	if (sp->lcp.opts & (1 << LCP_OPT_MAGIC)) {
+		if (! sp->lcp.magic)
+			sp->lcp.magic = random();
+		opt[i++] = LCP_OPT_MAGIC;
+		opt[i++] = 6;
+		opt[i++] = sp->lcp.magic >> 24;
+		opt[i++] = sp->lcp.magic >> 16;
+		opt[i++] = sp->lcp.magic >> 8;
+		opt[i++] = sp->lcp.magic;
+	}
+
+	if (sp->lcp.opts & (1 << LCP_OPT_MRU)) {
+		opt[i++] = LCP_OPT_MRU;
+		opt[i++] = 4;
+		opt[i++] = sp->lcp.mru >> 8;
+		opt[i++] = sp->lcp.mru;
+	}
+
+	if (sp->lcp.opts & (1 << LCP_OPT_AUTH_PROTO)) {
+		authproto = sp->hisauth.proto;
+		opt[i++] = LCP_OPT_AUTH_PROTO;
+		opt[i++] = authproto == PPP_CHAP? 5: 4;
+		opt[i++] = authproto >> 8;
+		opt[i++] = authproto;
+		if (authproto == PPP_CHAP)
+			opt[i++] = CHAP_MD5;
+	}
+
+	sp->confid[IDX_LCP] = ++sp->pp_seq[IDX_LCP];
+	sppp_cp_send (sp, PPP_LCP, CONF_REQ, sp->confid[IDX_LCP], i, &opt);
+}
+
+/*
+ * Check the open NCPs, return true if at least one NCP is open.
+ */
+static int
+sppp_ncp_check(struct sppp *sp)
+{
+	int i, mask;
+
+	for (i = 0, mask = 1; i < IDX_COUNT; i++, mask <<= 1)
+		if ((sp->lcp.protos & mask) && (cps[i])->flags & CP_NCP)
+			return 1;
+	return 0;
+}
+
+/*
+ * Re-check the open NCPs and see if we should terminate the link.
+ * Called by the NCPs during their tlf action handling.
+ */
+static void
+sppp_lcp_check_and_close(struct sppp *sp)
+{
+
+	if (sp->pp_phase < PHASE_NETWORK)
+		/* don't bother, we are already going down */
+		return;
+
+	if (sppp_ncp_check(sp))
+		return;
+
+	lcp.Close(sp);
+}
+
+/*
+ *--------------------------------------------------------------------------*
+ *                                                                          *
+ *                        The IPCP implementation.                          *
+ *                                                                          *
+ *--------------------------------------------------------------------------*
+ */
+
+#ifdef INET
+static void
+sppp_ipcp_init(struct sppp *sp)
+{
+	sp->ipcp.opts = 0;
+	sp->ipcp.flags = 0;
+	sp->state[IDX_IPCP] = STATE_INITIAL;
+	sp->fail_counter[IDX_IPCP] = 0;
+	sp->pp_seq[IDX_IPCP] = 0;
+	sp->pp_rseq[IDX_IPCP] = 0;
+ 	callout_init(&sp->ch[IDX_IPCP], CALLOUT_MPSAFE);
+}
+
+static void
+sppp_ipcp_up(struct sppp *sp)
+{
+	sppp_up_event(&ipcp, sp);
+}
+
+static void
+sppp_ipcp_down(struct sppp *sp)
+{
+	sppp_down_event(&ipcp, sp);
+}
+
+static void
+sppp_ipcp_open(struct sppp *sp)
+{
+	STDDCL;
+	u_long myaddr, hisaddr;
+
+	sp->ipcp.flags &= ~(IPCP_HISADDR_SEEN | IPCP_MYADDR_SEEN |
+			    IPCP_MYADDR_DYN | IPCP_VJ);
+	sp->ipcp.opts = 0;
+
+	sppp_get_ip_addrs(sp, &myaddr, &hisaddr, 0);
+	/*
+	 * If we don't have his address, this probably means our
+	 * interface doesn't want to talk IP at all.  (This could
+	 * be the case if somebody wants to speak only IPX, for
+	 * example.)  Don't open IPCP in this case.
+	 */
+	if (hisaddr == 0L) {
+		/* XXX this message should go away */
+		if (debug)
+			log(LOG_DEBUG, SPP_FMT "ipcp_open(): no IP interface\n",
+			    SPP_ARGS(ifp));
+		return;
+	}
+	if (myaddr == 0L) {
+		/*
+		 * I don't have an assigned address, so i need to
+		 * negotiate my address.
+		 */
+		sp->ipcp.flags |= IPCP_MYADDR_DYN;
+		sp->ipcp.opts |= (1 << IPCP_OPT_ADDRESS);
+	} else
+		sp->ipcp.flags |= IPCP_MYADDR_SEEN;
+	if (sp->confflags & CONF_ENABLE_VJ) {
+		sp->ipcp.opts |= (1 << IPCP_OPT_COMPRESSION);
+		sp->ipcp.max_state = MAX_STATES - 1;
+		sp->ipcp.compress_cid = 1;
+	}
+	sppp_open_event(&ipcp, sp);
+}
+
+static void
+sppp_ipcp_close(struct sppp *sp)
+{
+	sppp_close_event(&ipcp, sp);
+	if (sp->ipcp.flags & IPCP_MYADDR_DYN)
+		/*
+		 * My address was dynamic, clear it again.
+		 */
+		sppp_set_ip_addr(sp, 0L);
+}
+
+static void
+sppp_ipcp_TO(void *cookie)
+{
+	sppp_to_event(&ipcp, (struct sppp *)cookie);
+}
+
+/*
+ * Analyze a configure request.  Return true if it was agreeable, and
+ * caused action sca, false if it has been rejected or nak'ed, and
+ * caused action scn.  (The return value is used to make the state
+ * transition decision in the state automaton.)
+ */
+static int
+sppp_ipcp_RCR(struct sppp *sp, struct lcp_header *h, int len)
+{
+	u_char *buf, *r, *p;
+	struct ifnet *ifp = SP2IFP(sp);
+	int rlen, origlen, debug = ifp->if_flags & IFF_DEBUG;
+	u_long hisaddr, desiredaddr;
+	int gotmyaddr = 0;
+	int desiredcomp;
+
+	len -= 4;
+	origlen = len;
+	/*
+	 * Make sure to allocate a buf that can at least hold a
+	 * conf-nak with an `address' option.  We might need it below.
+	 */
+	buf = r = malloc ((len < 6? 6: len), M_TEMP, M_NOWAIT);
+	if (! buf)
+		return (0);
+
+	/* pass 1: see if we can recognize them */
+	if (debug)
+		log(LOG_DEBUG, SPP_FMT "ipcp parse opts: ",
+		    SPP_ARGS(ifp));
+	p = (void*) (h+1);
+	for (rlen=0; len >= 2 && p[1] >= 2 && len >= p[1];
+	    len-=p[1], p+=p[1]) {
+		if (debug)
+			log(-1, " %s ", sppp_ipcp_opt_name(*p));
+		switch (*p) {
+		case IPCP_OPT_COMPRESSION:
+			if (!(sp->confflags & CONF_ENABLE_VJ)) {
+				/* VJ compression administratively disabled */
+				if (debug)
+					log(-1, "[locally disabled] ");
+				break;
+			}
+			/*
+			 * In theory, we should only conf-rej an
+			 * option that is shorter than RFC 1618
+			 * requires (i.e. < 4), and should conf-nak
+			 * anything else that is not VJ.  However,
+			 * since our algorithm always uses the
+			 * original option to NAK it with new values,
+			 * things would become more complicated.  In
+			 * pratice, the only commonly implemented IP
+			 * compression option is VJ anyway, so the
+			 * difference is negligible.
+			 */
+			if (len >= 6 && p[1] == 6) {
+				/*
+				 * correctly formed compression option
+				 * that could be VJ compression
+				 */
+				continue;
+			}
+			if (debug)
+				log(-1,
+				    "optlen %d [invalid/unsupported] ",
+				    p[1]);
+			break;
+		case IPCP_OPT_ADDRESS:
+			if (len >= 6 && p[1] == 6) {
+				/* correctly formed address option */
+				continue;
+			}
+			if (debug)
+				log(-1, "[invalid] ");
+			break;
+		default:
+			/* Others not supported. */
+			if (debug)
+				log(-1, "[rej] ");
+			break;
+		}
+		/* Add the option to rejected list. */
+		bcopy (p, r, p[1]);
+		r += p[1];
+		rlen += p[1];
+	}
+	if (rlen) {
+		if (debug)
+			log(-1, " send conf-rej\n");
+		sppp_cp_send (sp, PPP_IPCP, CONF_REJ, h->ident, rlen, buf);
+		return 0;
+	} else if (debug)
+		log(-1, "\n");
+
+	/* pass 2: parse option values */
+	sppp_get_ip_addrs(sp, 0, &hisaddr, 0);
+	if (debug)
+		log(LOG_DEBUG, SPP_FMT "ipcp parse opt values: ",
+		       SPP_ARGS(ifp));
+	p = (void*) (h+1);
+	len = origlen;
+	for (rlen=0; len >= 2 && p[1] >= 2 && len >= p[1];
+	    len-=p[1], p+=p[1]) {
+		if (debug)
+			log(-1, " %s ", sppp_ipcp_opt_name(*p));
+		switch (*p) {
+		case IPCP_OPT_COMPRESSION:
+			desiredcomp = p[2] << 8 | p[3];
+			/* We only support VJ */
+			if (desiredcomp == IPCP_COMP_VJ) {
+				if (debug)
+					log(-1, "VJ [ack] ");
+				sp->ipcp.flags |= IPCP_VJ;
+				sl_compress_init(sp->pp_comp, p[4]);
+				sp->ipcp.max_state = p[4];
+				sp->ipcp.compress_cid = p[5];
+				continue;
+			}
+			if (debug)
+				log(-1,
+				    "compproto %#04x [not supported] ",
+				    desiredcomp);
+			p[2] = IPCP_COMP_VJ >> 8;
+			p[3] = IPCP_COMP_VJ;
+			p[4] = sp->ipcp.max_state;
+			p[5] = sp->ipcp.compress_cid;
+			break;
+		case IPCP_OPT_ADDRESS:
+			/* This is the address he wants in his end */
+			desiredaddr = p[2] << 24 | p[3] << 16 |
+				p[4] << 8 | p[5];
+			if (desiredaddr == hisaddr ||
+			    (hisaddr >= 1 && hisaddr <= 254 && desiredaddr != 0)) {
+				/*
+				 * Peer's address is same as our value,
+				 * or we have set it to 0.0.0.* to
+				 * indicate that we do not really care,
+				 * this is agreeable.  Gonna conf-ack
+				 * it.
+				 */
+				if (debug)
+					log(-1, "%s [ack] ",
+						sppp_dotted_quad(hisaddr));
+				/* record that we've seen it already */
+				sp->ipcp.flags |= IPCP_HISADDR_SEEN;
+				continue;
+			}
+			/*
+			 * The address wasn't agreeable.  This is either
+			 * he sent us 0.0.0.0, asking to assign him an
+			 * address, or he send us another address not
+			 * matching our value.  Either case, we gonna
+			 * conf-nak it with our value.
+			 * XXX: we should "rej" if hisaddr == 0
+			 */
+			if (debug) {
+				if (desiredaddr == 0)
+					log(-1, "[addr requested] ");
+				else
+					log(-1, "%s [not agreed] ",
+						sppp_dotted_quad(desiredaddr));
+
+			}
+			p[2] = hisaddr >> 24;
+			p[3] = hisaddr >> 16;
+			p[4] = hisaddr >> 8;
+			p[5] = hisaddr;
+			break;
+		}
+		/* Add the option to nak'ed list. */
+		bcopy (p, r, p[1]);
+		r += p[1];
+		rlen += p[1];
+	}
+
+	/*
+	 * If we are about to conf-ack the request, but haven't seen
+	 * his address so far, gonna conf-nak it instead, with the
+	 * `address' option present and our idea of his address being
+	 * filled in there, to request negotiation of both addresses.
+	 *
+	 * XXX This can result in an endless req - nak loop if peer
+	 * doesn't want to send us his address.  Q: What should we do
+	 * about it?  XXX  A: implement the max-failure counter.
+	 */
+	if (rlen == 0 && !(sp->ipcp.flags & IPCP_HISADDR_SEEN) && !gotmyaddr) {
+		buf[0] = IPCP_OPT_ADDRESS;
+		buf[1] = 6;
+		buf[2] = hisaddr >> 24;
+		buf[3] = hisaddr >> 16;
+		buf[4] = hisaddr >> 8;
+		buf[5] = hisaddr;
+		rlen = 6;
+		if (debug)
+			log(-1, "still need hisaddr ");
+	}
+
+	if (rlen) {
+		if (debug)
+			log(-1, " send conf-nak\n");
+		sppp_cp_send (sp, PPP_IPCP, CONF_NAK, h->ident, rlen, buf);
+	} else {
+		if (debug)
+			log(-1, " send conf-ack\n");
+		sppp_cp_send (sp, PPP_IPCP, CONF_ACK,
+			      h->ident, origlen, h+1);
+	}
+
+	free (buf, M_TEMP);
+	return (rlen == 0);
+}
+
+/*
+ * Analyze the IPCP Configure-Reject option list, and adjust our
+ * negotiation.
+ */
+static void
+sppp_ipcp_RCN_rej(struct sppp *sp, struct lcp_header *h, int len)
+{
+	u_char *buf, *p;
+	struct ifnet *ifp = SP2IFP(sp);
+	int debug = ifp->if_flags & IFF_DEBUG;
+
+	len -= 4;
+	buf = malloc (len, M_TEMP, M_NOWAIT);
+	if (!buf)
+		return;
+
+	if (debug)
+		log(LOG_DEBUG, SPP_FMT "ipcp rej opts: ",
+		    SPP_ARGS(ifp));
+
+	p = (void*) (h+1);
+	for (; len >= 2 && p[1] >= 2 && len >= p[1];
+	    len -= p[1], p += p[1]) {
+		if (debug)
+			log(-1, " %s ", sppp_ipcp_opt_name(*p));
+		switch (*p) {
+		case IPCP_OPT_COMPRESSION:
+			sp->ipcp.opts &= ~(1 << IPCP_OPT_COMPRESSION);
+			break;
+		case IPCP_OPT_ADDRESS:
+			/*
+			 * Peer doesn't grok address option.  This is
+			 * bad.  XXX  Should we better give up here?
+			 * XXX We could try old "addresses" option...
+			 */
+			sp->ipcp.opts &= ~(1 << IPCP_OPT_ADDRESS);
+			break;
+		}
+	}
+	if (debug)
+		log(-1, "\n");
+	free (buf, M_TEMP);
+	return;
+}
+
+/*
+ * Analyze the IPCP Configure-NAK option list, and adjust our
+ * negotiation.
+ */
+static void
+sppp_ipcp_RCN_nak(struct sppp *sp, struct lcp_header *h, int len)
+{
+	u_char *buf, *p;
+	struct ifnet *ifp = SP2IFP(sp);
+	int debug = ifp->if_flags & IFF_DEBUG;
+	int desiredcomp;
+	u_long wantaddr;
+
+	len -= 4;
+	buf = malloc (len, M_TEMP, M_NOWAIT);
+	if (!buf)
+		return;
+
+	if (debug)
+		log(LOG_DEBUG, SPP_FMT "ipcp nak opts: ",
+		    SPP_ARGS(ifp));
+
+	p = (void*) (h+1);
+	for (; len >= 2 && p[1] >= 2 && len >= p[1];
+	    len -= p[1], p += p[1]) {
+		if (debug)
+			log(-1, " %s ", sppp_ipcp_opt_name(*p));
+		switch (*p) {
+		case IPCP_OPT_COMPRESSION:
+			if (len >= 6 && p[1] == 6) {
+				desiredcomp = p[2] << 8 | p[3];
+				if (debug)
+					log(-1, "[wantcomp %#04x] ",
+						desiredcomp);
+				if (desiredcomp == IPCP_COMP_VJ) {
+					sl_compress_init(sp->pp_comp, p[4]);
+					sp->ipcp.max_state = p[4];
+					sp->ipcp.compress_cid = p[5];
+					if (debug)
+						log(-1, "[agree] ");
+				} else
+					sp->ipcp.opts &=
+						~(1 << IPCP_OPT_COMPRESSION);
+			}
+			break;
+		case IPCP_OPT_ADDRESS:
+			/*
+			 * Peer doesn't like our local IP address.  See
+			 * if we can do something for him.  We'll drop
+			 * him our address then.
+			 */
+			if (len >= 6 && p[1] == 6) {
+				wantaddr = p[2] << 24 | p[3] << 16 |
+					p[4] << 8 | p[5];
+				sp->ipcp.opts |= (1 << IPCP_OPT_ADDRESS);
+				if (debug)
+					log(-1, "[wantaddr %s] ",
+					       sppp_dotted_quad(wantaddr));
+				/*
+				 * When doing dynamic address assignment,
+				 * we accept his offer.  Otherwise, we
+				 * ignore it and thus continue to negotiate
+				 * our already existing value.
+			 	 * XXX: Bogus, if he said no once, he'll
+				 * just say no again, might as well die.
+				 */
+				if (sp->ipcp.flags & IPCP_MYADDR_DYN) {
+					sppp_set_ip_addr(sp, wantaddr);
+					if (debug)
+						log(-1, "[agree] ");
+					sp->ipcp.flags |= IPCP_MYADDR_SEEN;
+				}
+			}
+			break;
+		}
+	}
+	if (debug)
+		log(-1, "\n");
+	free (buf, M_TEMP);
+	return;
+}
+
+static void
+sppp_ipcp_tlu(struct sppp *sp)
+{
+	/* we are up - notify isdn daemon */
+	if (sp->pp_con)
+		sp->pp_con(sp);
+}
+
+static void
+sppp_ipcp_tld(struct sppp *sp)
+{
+}
+
+static void
+sppp_ipcp_tls(struct sppp *sp)
+{
+	/* indicate to LCP that it must stay alive */
+	sp->lcp.protos |= (1 << IDX_IPCP);
+}
+
+static void
+sppp_ipcp_tlf(struct sppp *sp)
+{
+	/* we no longer need LCP */
+	sp->lcp.protos &= ~(1 << IDX_IPCP);
+	sppp_lcp_check_and_close(sp);
+}
+
+static void
+sppp_ipcp_scr(struct sppp *sp)
+{
+	char opt[6 /* compression */ + 6 /* address */];
+	u_long ouraddr;
+	int i = 0;
+
+	if (sp->ipcp.opts & (1 << IPCP_OPT_COMPRESSION)) {
+		opt[i++] = IPCP_OPT_COMPRESSION;
+		opt[i++] = 6;
+		opt[i++] = IPCP_COMP_VJ >> 8;
+		opt[i++] = IPCP_COMP_VJ;
+		opt[i++] = sp->ipcp.max_state;
+		opt[i++] = sp->ipcp.compress_cid;
+	}
+	if (sp->ipcp.opts & (1 << IPCP_OPT_ADDRESS)) {
+		sppp_get_ip_addrs(sp, &ouraddr, 0, 0);
+		opt[i++] = IPCP_OPT_ADDRESS;
+		opt[i++] = 6;
+		opt[i++] = ouraddr >> 24;
+		opt[i++] = ouraddr >> 16;
+		opt[i++] = ouraddr >> 8;
+		opt[i++] = ouraddr;
+	}
+
+	sp->confid[IDX_IPCP] = ++sp->pp_seq[IDX_IPCP];
+	sppp_cp_send(sp, PPP_IPCP, CONF_REQ, sp->confid[IDX_IPCP], i, &opt);
+}
+#else /* !INET */
+static void
+sppp_ipcp_init(struct sppp *sp)
+{
+}
+
+static void
+sppp_ipcp_up(struct sppp *sp)
+{
+}
+
+static void
+sppp_ipcp_down(struct sppp *sp)
+{
+}
+
+static void
+sppp_ipcp_open(struct sppp *sp)
+{
+}
+
+static void
+sppp_ipcp_close(struct sppp *sp)
+{
+}
+
+static void
+sppp_ipcp_TO(void *cookie)
+{
+}
+
+static int
+sppp_ipcp_RCR(struct sppp *sp, struct lcp_header *h, int len)
+{
+	return (0);
+}
+
+static void
+sppp_ipcp_RCN_rej(struct sppp *sp, struct lcp_header *h, int len)
+{
+}
+
+static void
+sppp_ipcp_RCN_nak(struct sppp *sp, struct lcp_header *h, int len)
+{
+}
+
+static void
+sppp_ipcp_tlu(struct sppp *sp)
+{
+}
+
+static void
+sppp_ipcp_tld(struct sppp *sp)
+{
+}
+
+static void
+sppp_ipcp_tls(struct sppp *sp)
+{
+}
+
+static void
+sppp_ipcp_tlf(struct sppp *sp)
+{
+}
+
+static void
+sppp_ipcp_scr(struct sppp *sp)
+{
+}
+#endif
+
+/*
+ *--------------------------------------------------------------------------*
+ *                                                                          *
+ *                      The IPv6CP implementation.                          *
+ *                                                                          *
+ *--------------------------------------------------------------------------*
+ */
+
+#ifdef INET6
+static void
+sppp_ipv6cp_init(struct sppp *sp)
+{
+	sp->ipv6cp.opts = 0;
+	sp->ipv6cp.flags = 0;
+	sp->state[IDX_IPV6CP] = STATE_INITIAL;
+	sp->fail_counter[IDX_IPV6CP] = 0;
+	sp->pp_seq[IDX_IPV6CP] = 0;
+	sp->pp_rseq[IDX_IPV6CP] = 0;
+ 	callout_init(&sp->ch[IDX_IPV6CP], CALLOUT_MPSAFE);
+}
+
+static void
+sppp_ipv6cp_up(struct sppp *sp)
+{
+	sppp_up_event(&ipv6cp, sp);
+}
+
+static void
+sppp_ipv6cp_down(struct sppp *sp)
+{
+	sppp_down_event(&ipv6cp, sp);
+}
+
+static void
+sppp_ipv6cp_open(struct sppp *sp)
+{
+	STDDCL;
+	struct in6_addr myaddr, hisaddr;
+
+#ifdef IPV6CP_MYIFID_DYN
+	sp->ipv6cp.flags &= ~(IPV6CP_MYIFID_SEEN|IPV6CP_MYIFID_DYN);
+#else
+	sp->ipv6cp.flags &= ~IPV6CP_MYIFID_SEEN;
+#endif
+
+	sppp_get_ip6_addrs(sp, &myaddr, &hisaddr, 0);
+	/*
+	 * If we don't have our address, this probably means our
+	 * interface doesn't want to talk IPv6 at all.  (This could
+	 * be the case if somebody wants to speak only IPX, for
+	 * example.)  Don't open IPv6CP in this case.
+	 */
+	if (IN6_IS_ADDR_UNSPECIFIED(&myaddr)) {
+		/* XXX this message should go away */
+		if (debug)
+			log(LOG_DEBUG, SPP_FMT "ipv6cp_open(): no IPv6 interface\n",
+			    SPP_ARGS(ifp));
+		return;
+	}
+
+	sp->ipv6cp.flags |= IPV6CP_MYIFID_SEEN;
+	sp->ipv6cp.opts |= (1 << IPV6CP_OPT_IFID);
+	sppp_open_event(&ipv6cp, sp);
+}
+
+static void
+sppp_ipv6cp_close(struct sppp *sp)
+{
+	sppp_close_event(&ipv6cp, sp);
+}
+
+static void
+sppp_ipv6cp_TO(void *cookie)
+{
+	sppp_to_event(&ipv6cp, (struct sppp *)cookie);
+}
+
+/*
+ * Analyze a configure request.  Return true if it was agreeable, and
+ * caused action sca, false if it has been rejected or nak'ed, and
+ * caused action scn.  (The return value is used to make the state
+ * transition decision in the state automaton.)
+ */
+static int
+sppp_ipv6cp_RCR(struct sppp *sp, struct lcp_header *h, int len)
+{
+	u_char *buf, *r, *p;
+	struct ifnet *ifp = SP2IFP(sp);
+	int rlen, origlen, debug = ifp->if_flags & IFF_DEBUG;
+	struct in6_addr myaddr, desiredaddr, suggestaddr;
+	int ifidcount;
+	int type;
+	int collision, nohisaddr;
+	char ip6buf[INET6_ADDRSTRLEN];
+
+	len -= 4;
+	origlen = len;
+	/*
+	 * Make sure to allocate a buf that can at least hold a
+	 * conf-nak with an `address' option.  We might need it below.
+	 */
+	buf = r = malloc ((len < 6? 6: len), M_TEMP, M_NOWAIT);
+	if (! buf)
+		return (0);
+
+	/* pass 1: see if we can recognize them */
+	if (debug)
+		log(LOG_DEBUG, SPP_FMT "ipv6cp parse opts:",
+		    SPP_ARGS(ifp));
+	p = (void*) (h+1);
+	ifidcount = 0;
+	for (rlen=0; len >= 2 && p[1] >= 2 && len >= p[1];
+	    len-=p[1], p+=p[1]) {
+		if (debug)
+			log(-1, " %s", sppp_ipv6cp_opt_name(*p));
+		switch (*p) {
+		case IPV6CP_OPT_IFID:
+			if (len >= 10 && p[1] == 10 && ifidcount == 0) {
+				/* correctly formed address option */
+				ifidcount++;
+				continue;
+			}
+			if (debug)
+				log(-1, " [invalid]");
+			break;
+#ifdef notyet
+		case IPV6CP_OPT_COMPRESSION:
+			if (len >= 4 && p[1] >= 4) {
+				/* correctly formed compress option */
+				continue;
+			}
+			if (debug)
+				log(-1, " [invalid]");
+			break;
+#endif
+		default:
+			/* Others not supported. */
+			if (debug)
+				log(-1, " [rej]");
+			break;
+		}
+		/* Add the option to rejected list. */
+		bcopy (p, r, p[1]);
+		r += p[1];
+		rlen += p[1];
+	}
+	if (rlen) {
+		if (debug)
+			log(-1, " send conf-rej\n");
+		sppp_cp_send (sp, PPP_IPV6CP, CONF_REJ, h->ident, rlen, buf);
+		goto end;
+	} else if (debug)
+		log(-1, "\n");
+
+	/* pass 2: parse option values */
+	sppp_get_ip6_addrs(sp, &myaddr, 0, 0);
+	if (debug)
+		log(LOG_DEBUG, SPP_FMT "ipv6cp parse opt values: ",
+		    SPP_ARGS(ifp));
+	p = (void*) (h+1);
+	len = origlen;
+	type = CONF_ACK;
+	for (rlen=0; len >= 2 && p[1] >= 2 && len >= p[1];
+	    len-=p[1], p+=p[1]) {
+		if (debug)
+			log(-1, " %s", sppp_ipv6cp_opt_name(*p));
+		switch (*p) {
+#ifdef notyet
+		case IPV6CP_OPT_COMPRESSION:
+			continue;
+#endif
+		case IPV6CP_OPT_IFID:
+			bzero(&desiredaddr, sizeof(desiredaddr));
+			bcopy(&p[2], &desiredaddr.s6_addr[8], 8);
+			collision = (bcmp(&desiredaddr.s6_addr[8],
+					  &myaddr.s6_addr[8], 8) == 0);
+			nohisaddr = IN6_IS_ADDR_UNSPECIFIED(&desiredaddr);
+
+			desiredaddr.s6_addr16[0] = htons(0xfe80);
+			(void)in6_setscope(&desiredaddr, SP2IFP(sp), NULL);
+
+			if (!collision && !nohisaddr) {
+				/* no collision, hisaddr known - Conf-Ack */
+				type = CONF_ACK;
+
+				if (debug) {
+					log(-1, " %s [%s]",
+					    ip6_sprintf(ip6buf, &desiredaddr),
+					    sppp_cp_type_name(type));
+				}
+				continue;
+			}
+
+			bzero(&suggestaddr, sizeof(&suggestaddr));
+			if (collision && nohisaddr) {
+				/* collision, hisaddr unknown - Conf-Rej */
+				type = CONF_REJ;
+				bzero(&p[2], 8);
+			} else {
+				/*
+				 * - no collision, hisaddr unknown, or
+				 * - collision, hisaddr known
+				 * Conf-Nak, suggest hisaddr
+				 */
+				type = CONF_NAK;
+				sppp_suggest_ip6_addr(sp, &suggestaddr);
+				bcopy(&suggestaddr.s6_addr[8], &p[2], 8);
+			}
+			if (debug)
+				log(-1, " %s [%s]",
+				    ip6_sprintf(ip6buf, &desiredaddr),
+				    sppp_cp_type_name(type));
+			break;
+		}
+		/* Add the option to nak'ed list. */
+		bcopy (p, r, p[1]);
+		r += p[1];
+		rlen += p[1];
+	}
+
+	if (rlen == 0 && type == CONF_ACK) {
+		if (debug)
+			log(-1, " send %s\n", sppp_cp_type_name(type));
+		sppp_cp_send (sp, PPP_IPV6CP, type, h->ident, origlen, h+1);
+	} else {
+#ifdef DIAGNOSTIC
+		if (type == CONF_ACK)
+			panic("IPv6CP RCR: CONF_ACK with non-zero rlen");
+#endif
+
+		if (debug) {
+			log(-1, " send %s suggest %s\n",
+			    sppp_cp_type_name(type),
+			    ip6_sprintf(ip6buf, &suggestaddr));
+		}
+		sppp_cp_send (sp, PPP_IPV6CP, type, h->ident, rlen, buf);
+	}
+
+ end:
+	free (buf, M_TEMP);
+	return (rlen == 0);
+}
+
+/*
+ * Analyze the IPv6CP Configure-Reject option list, and adjust our
+ * negotiation.
+ */
+static void
+sppp_ipv6cp_RCN_rej(struct sppp *sp, struct lcp_header *h, int len)
+{
+	u_char *buf, *p;
+	struct ifnet *ifp = SP2IFP(sp);
+	int debug = ifp->if_flags & IFF_DEBUG;
+
+	len -= 4;
+	buf = malloc (len, M_TEMP, M_NOWAIT);
+	if (!buf)
+		return;
+
+	if (debug)
+		log(LOG_DEBUG, SPP_FMT "ipv6cp rej opts:",
+		    SPP_ARGS(ifp));
+
+	p = (void*) (h+1);
+	for (; len >= 2 && p[1] >= 2 && len >= p[1];
+	    len -= p[1], p += p[1]) {
+		if (debug)
+			log(-1, " %s", sppp_ipv6cp_opt_name(*p));
+		switch (*p) {
+		case IPV6CP_OPT_IFID:
+			/*
+			 * Peer doesn't grok address option.  This is
+			 * bad.  XXX  Should we better give up here?
+			 */
+			sp->ipv6cp.opts &= ~(1 << IPV6CP_OPT_IFID);
+			break;
+#ifdef notyet
+		case IPV6CP_OPT_COMPRESS:
+			sp->ipv6cp.opts &= ~(1 << IPV6CP_OPT_COMPRESS);
+			break;
+#endif
+		}
+	}
+	if (debug)
+		log(-1, "\n");
+	free (buf, M_TEMP);
+	return;
+}
+
+/*
+ * Analyze the IPv6CP Configure-NAK option list, and adjust our
+ * negotiation.
+ */
+static void
+sppp_ipv6cp_RCN_nak(struct sppp *sp, struct lcp_header *h, int len)
+{
+	u_char *buf, *p;
+	struct ifnet *ifp = SP2IFP(sp);
+	int debug = ifp->if_flags & IFF_DEBUG;
+	struct in6_addr suggestaddr;
+	char ip6buf[INET6_ADDRSTRLEN];
+
+	len -= 4;
+	buf = malloc (len, M_TEMP, M_NOWAIT);
+	if (!buf)
+		return;
+
+	if (debug)
+		log(LOG_DEBUG, SPP_FMT "ipv6cp nak opts:",
+		    SPP_ARGS(ifp));
+
+	p = (void*) (h+1);
+	for (; len >= 2 && p[1] >= 2 && len >= p[1];
+	    len -= p[1], p += p[1]) {
+		if (debug)
+			log(-1, " %s", sppp_ipv6cp_opt_name(*p));
+		switch (*p) {
+		case IPV6CP_OPT_IFID:
+			/*
+			 * Peer doesn't like our local ifid.  See
+			 * if we can do something for him.  We'll drop
+			 * him our address then.
+			 */
+			if (len < 10 || p[1] != 10)
+				break;
+			bzero(&suggestaddr, sizeof(suggestaddr));
+			suggestaddr.s6_addr16[0] = htons(0xfe80);
+			(void)in6_setscope(&suggestaddr, SP2IFP(sp), NULL);
+			bcopy(&p[2], &suggestaddr.s6_addr[8], 8);
+
+			sp->ipv6cp.opts |= (1 << IPV6CP_OPT_IFID);
+			if (debug)
+				log(-1, " [suggestaddr %s]",
+				       ip6_sprintf(ip6buf, &suggestaddr));
+#ifdef IPV6CP_MYIFID_DYN
+			/*
+			 * When doing dynamic address assignment,
+			 * we accept his offer.
+			 */
+			if (sp->ipv6cp.flags & IPV6CP_MYIFID_DYN) {
+				struct in6_addr lastsuggest;
+				/*
+				 * If <suggested myaddr from peer> equals to
+				 * <hisaddr we have suggested last time>,
+				 * we have a collision.  generate new random
+				 * ifid.
+				 */
+				sppp_suggest_ip6_addr(&lastsuggest);
+				if (IN6_ARE_ADDR_EQUAL(&suggestaddr,
+						       lastsuggest)) {
+					if (debug)
+						log(-1, " [random]");
+					sppp_gen_ip6_addr(sp, &suggestaddr);
+				}
+				sppp_set_ip6_addr(sp, &suggestaddr, 0);
+				if (debug)
+					log(-1, " [agree]");
+				sp->ipv6cp.flags |= IPV6CP_MYIFID_SEEN;
+			}
+#else
+			/*
+			 * Since we do not do dynamic address assignment,
+			 * we ignore it and thus continue to negotiate
+			 * our already existing value.  This can possibly
+			 * go into infinite request-reject loop.
+			 *
+			 * This is not likely because we normally use
+			 * ifid based on MAC-address.
+			 * If you have no ethernet card on the node, too bad.
+			 * XXX should we use fail_counter?
+			 */
+#endif
+			break;
+#ifdef notyet
+		case IPV6CP_OPT_COMPRESS:
+			/*
+			 * Peer wants different compression parameters.
+			 */
+			break;
+#endif
+		}
+	}
+	if (debug)
+		log(-1, "\n");
+	free (buf, M_TEMP);
+	return;
+}
+static void
+sppp_ipv6cp_tlu(struct sppp *sp)
+{
+	/* we are up - notify isdn daemon */
+	if (sp->pp_con)
+		sp->pp_con(sp);
+}
+
+static void
+sppp_ipv6cp_tld(struct sppp *sp)
+{
+}
+
+static void
+sppp_ipv6cp_tls(struct sppp *sp)
+{
+	/* indicate to LCP that it must stay alive */
+	sp->lcp.protos |= (1 << IDX_IPV6CP);
+}
+
+static void
+sppp_ipv6cp_tlf(struct sppp *sp)
+{
+
+#if 0	/* need #if 0 to close IPv6CP properly */
+	/* we no longer need LCP */
+	sp->lcp.protos &= ~(1 << IDX_IPV6CP);
+	sppp_lcp_check_and_close(sp);
+#endif
+}
+
+static void
+sppp_ipv6cp_scr(struct sppp *sp)
+{
+	char opt[10 /* ifid */ + 4 /* compression, minimum */];
+	struct in6_addr ouraddr;
+	int i = 0;
+
+	if (sp->ipv6cp.opts & (1 << IPV6CP_OPT_IFID)) {
+		sppp_get_ip6_addrs(sp, &ouraddr, 0, 0);
+		opt[i++] = IPV6CP_OPT_IFID;
+		opt[i++] = 10;
+		bcopy(&ouraddr.s6_addr[8], &opt[i], 8);
+		i += 8;
+	}
+
+#ifdef notyet
+	if (sp->ipv6cp.opts & (1 << IPV6CP_OPT_COMPRESSION)) {
+		opt[i++] = IPV6CP_OPT_COMPRESSION;
+		opt[i++] = 4;
+		opt[i++] = 0;   /* TBD */
+		opt[i++] = 0;   /* TBD */
+		/* variable length data may follow */
+	}
+#endif
+
+	sp->confid[IDX_IPV6CP] = ++sp->pp_seq[IDX_IPV6CP];
+	sppp_cp_send(sp, PPP_IPV6CP, CONF_REQ, sp->confid[IDX_IPV6CP], i, &opt);
+}
+#else /*INET6*/
+static void sppp_ipv6cp_init(struct sppp *sp)
+{
+}
+
+static void sppp_ipv6cp_up(struct sppp *sp)
+{
+}
+
+static void sppp_ipv6cp_down(struct sppp *sp)
+{
+}
+
+
+static void sppp_ipv6cp_open(struct sppp *sp)
+{
+}
+
+static void sppp_ipv6cp_close(struct sppp *sp)
+{
+}
+
+static void sppp_ipv6cp_TO(void *sp)
+{
+}
+
+static int sppp_ipv6cp_RCR(struct sppp *sp, struct lcp_header *h, int len)
+{
+	return 0;
+}
+
+static void sppp_ipv6cp_RCN_rej(struct sppp *sp, struct lcp_header *h, int len)
+{
+}
+
+static void sppp_ipv6cp_RCN_nak(struct sppp *sp, struct lcp_header *h, int len)
+{
+}
+
+static void sppp_ipv6cp_tlu(struct sppp *sp)
+{
+}
+
+static void sppp_ipv6cp_tld(struct sppp *sp)
+{
+}
+
+static void sppp_ipv6cp_tls(struct sppp *sp)
+{
+}
+
+static void sppp_ipv6cp_tlf(struct sppp *sp)
+{
+}
+
+static void sppp_ipv6cp_scr(struct sppp *sp)
+{
+}
+#endif /*INET6*/
+
+/*
+ *--------------------------------------------------------------------------*
+ *                                                                          *
+ *                        The CHAP implementation.                          *
+ *                                                                          *
+ *--------------------------------------------------------------------------*
+ */
+
+/*
+ * The authentication protocols don't employ a full-fledged state machine as
+ * the control protocols do, since they do have Open and Close events, but
+ * not Up and Down, nor are they explicitly terminated.  Also, use of the
+ * authentication protocols may be different in both directions (this makes
+ * sense, think of a machine that never accepts incoming calls but only
+ * calls out, it doesn't require the called party to authenticate itself).
+ *
+ * Our state machine for the local authentication protocol (we are requesting
+ * the peer to authenticate) looks like:
+ *
+ *						    RCA-
+ *	      +--------------------------------------------+
+ *	      V					    scn,tld|
+ *	  +--------+			       Close   +---------+ RCA+
+ *	  |	   |<----------------------------------|	 |------+
+ *   +--->| Closed |				TO*    | Opened	 | sca	|
+ *   |	  |	   |-----+		       +-------|	 |<-----+
+ *   |	  +--------+ irc |		       |       +---------+
+ *   |	    ^		 |		       |	   ^
+ *   |	    |		 |		       |	   |
+ *   |	    |		 |		       |	   |
+ *   |	 TO-|		 |		       |	   |
+ *   |	    |tld  TO+	 V		       |	   |
+ *   |	    |	+------->+		       |	   |
+ *   |	    |	|	 |		       |	   |
+ *   |	  +--------+	 V		       |	   |
+ *   |	  |	   |<----+<--------------------+	   |
+ *   |	  | Req-   | scr				   |
+ *   |	  | Sent   |					   |
+ *   |	  |	   |					   |
+ *   |	  +--------+					   |
+ *   | RCA- |	| RCA+					   |
+ *   +------+	+------------------------------------------+
+ *   scn,tld	  sca,irc,ict,tlu
+ *
+ *
+ *   with:
+ *
+ *	Open:	LCP reached authentication phase
+ *	Close:	LCP reached terminate phase
+ *
+ *	RCA+:	received reply (pap-req, chap-response), acceptable
+ *	RCN:	received reply (pap-req, chap-response), not acceptable
+ *	TO+:	timeout with restart counter >= 0
+ *	TO-:	timeout with restart counter < 0
+ *	TO*:	reschedule timeout for CHAP
+ *
+ *	scr:	send request packet (none for PAP, chap-challenge)
+ *	sca:	send ack packet (pap-ack, chap-success)
+ *	scn:	send nak packet (pap-nak, chap-failure)
+ *	ict:	initialize re-challenge timer (CHAP only)
+ *
+ *	tlu:	this-layer-up, LCP reaches network phase
+ *	tld:	this-layer-down, LCP enters terminate phase
+ *
+ * Note that in CHAP mode, after sending a new challenge, while the state
+ * automaton falls back into Req-Sent state, it doesn't signal a tld
+ * event to LCP, so LCP remains in network phase.  Only after not getting
+ * any response (or after getting an unacceptable response), CHAP closes,
+ * causing LCP to enter terminate phase.
+ *
+ * With PAP, there is no initial request that can be sent.  The peer is
+ * expected to send one based on the successful negotiation of PAP as
+ * the authentication protocol during the LCP option negotiation.
+ *
+ * Incoming authentication protocol requests (remote requests
+ * authentication, we are peer) don't employ a state machine at all,
+ * they are simply answered.  Some peers [Ascend P50 firmware rev
+ * 4.50] react allergically when sending IPCP requests while they are
+ * still in authentication phase (thereby violating the standard that
+ * demands that these NCP packets are to be discarded), so we keep
+ * track of the peer demanding us to authenticate, and only proceed to
+ * phase network once we've seen a positive acknowledge for the
+ * authentication.
+ */
+
+/*
+ * Handle incoming CHAP packets.
+ */
+static void
+sppp_chap_input(struct sppp *sp, struct mbuf *m)
+{
+	STDDCL;
+	struct lcp_header *h;
+	int len, x;
+	u_char *value, *name, digest[AUTHKEYLEN], dsize;
+	int value_len, name_len;
+	MD5_CTX ctx;
+
+	len = m->m_pkthdr.len;
+	if (len < 4) {
+		if (debug)
+			log(LOG_DEBUG,
+			    SPP_FMT "chap invalid packet length: %d bytes\n",
+			    SPP_ARGS(ifp), len);
+		return;
+	}
+	h = mtod (m, struct lcp_header*);
+	if (len > ntohs (h->len))
+		len = ntohs (h->len);
+
+	switch (h->type) {
+	/* challenge, failure and success are his authproto */
+	case CHAP_CHALLENGE:
+		value = 1 + (u_char*)(h+1);
+		value_len = value[-1];
+		name = value + value_len;
+		name_len = len - value_len - 5;
+		if (name_len < 0) {
+			if (debug) {
+				log(LOG_DEBUG,
+				    SPP_FMT "chap corrupted challenge "
+				    "<%s id=0x%x len=%d",
+				    SPP_ARGS(ifp),
+				    sppp_auth_type_name(PPP_CHAP, h->type),
+				    h->ident, ntohs(h->len));
+				sppp_print_bytes((u_char*) (h+1), len-4);
+				log(-1, ">\n");
+			}
+			break;
+		}
+
+		if (debug) {
+			log(LOG_DEBUG,
+			    SPP_FMT "chap input <%s id=0x%x len=%d name=",
+			    SPP_ARGS(ifp),
+			    sppp_auth_type_name(PPP_CHAP, h->type), h->ident,
+			    ntohs(h->len));
+			sppp_print_string((char*) name, name_len);
+			log(-1, " value-size=%d value=", value_len);
+			sppp_print_bytes(value, value_len);
+			log(-1, ">\n");
+		}
+
+		/* Compute reply value. */
+		MD5Init(&ctx);
+		MD5Update(&ctx, &h->ident, 1);
+		MD5Update(&ctx, sp->myauth.secret,
+			  sppp_strnlen(sp->myauth.secret, AUTHKEYLEN));
+		MD5Update(&ctx, value, value_len);
+		MD5Final(digest, &ctx);
+		dsize = sizeof digest;
+
+		sppp_auth_send(&chap, sp, CHAP_RESPONSE, h->ident,
+			       sizeof dsize, (const char *)&dsize,
+			       sizeof digest, digest,
+			       (size_t)sppp_strnlen(sp->myauth.name, AUTHNAMELEN),
+			       sp->myauth.name,
+			       0);
+		break;
+
+	case CHAP_SUCCESS:
+		if (debug) {
+			log(LOG_DEBUG, SPP_FMT "chap success",
+			    SPP_ARGS(ifp));
+			if (len > 4) {
+				log(-1, ": ");
+				sppp_print_string((char*)(h + 1), len - 4);
+			}
+			log(-1, "\n");
+		}
+		x = splimp();
+		SPPP_LOCK(sp);
+		sp->pp_flags &= ~PP_NEEDAUTH;
+		if (sp->myauth.proto == PPP_CHAP &&
+		    (sp->lcp.opts & (1 << LCP_OPT_AUTH_PROTO)) &&
+		    (sp->lcp.protos & (1 << IDX_CHAP)) == 0) {
+			/*
+			 * We are authenticator for CHAP but didn't
+			 * complete yet.  Leave it to tlu to proceed
+			 * to network phase.
+			 */
+			SPPP_UNLOCK(sp);
+			splx(x);
+			break;
+		}
+		SPPP_UNLOCK(sp);
+		splx(x);
+		sppp_phase_network(sp);
+		break;
+
+	case CHAP_FAILURE:
+		if (debug) {
+			log(LOG_INFO, SPP_FMT "chap failure",
+			    SPP_ARGS(ifp));
+			if (len > 4) {
+				log(-1, ": ");
+				sppp_print_string((char*)(h + 1), len - 4);
+			}
+			log(-1, "\n");
+		} else
+			log(LOG_INFO, SPP_FMT "chap failure\n",
+			    SPP_ARGS(ifp));
+		/* await LCP shutdown by authenticator */
+		break;
+
+	/* response is my authproto */
+	case CHAP_RESPONSE:
+		value = 1 + (u_char*)(h+1);
+		value_len = value[-1];
+		name = value + value_len;
+		name_len = len - value_len - 5;
+		if (name_len < 0) {
+			if (debug) {
+				log(LOG_DEBUG,
+				    SPP_FMT "chap corrupted response "
+				    "<%s id=0x%x len=%d",
+				    SPP_ARGS(ifp),
+				    sppp_auth_type_name(PPP_CHAP, h->type),
+				    h->ident, ntohs(h->len));
+				sppp_print_bytes((u_char*)(h+1), len-4);
+				log(-1, ">\n");
+			}
+			break;
+		}
+		if (h->ident != sp->confid[IDX_CHAP]) {
+			if (debug)
+				log(LOG_DEBUG,
+				    SPP_FMT "chap dropping response for old ID "
+				    "(got %d, expected %d)\n",
+				    SPP_ARGS(ifp),
+				    h->ident, sp->confid[IDX_CHAP]);
+			break;
+		}
+		if (name_len != sppp_strnlen(sp->hisauth.name, AUTHNAMELEN)
+		    || bcmp(name, sp->hisauth.name, name_len) != 0) {
+			log(LOG_INFO, SPP_FMT "chap response, his name ",
+			    SPP_ARGS(ifp));
+			sppp_print_string(name, name_len);
+			log(-1, " != expected ");
+			sppp_print_string(sp->hisauth.name,
+					  sppp_strnlen(sp->hisauth.name, AUTHNAMELEN));
+			log(-1, "\n");
+		}
+		if (debug) {
+			log(LOG_DEBUG, SPP_FMT "chap input(%s) "
+			    "<%s id=0x%x len=%d name=",
+			    SPP_ARGS(ifp),
+			    sppp_state_name(sp->state[IDX_CHAP]),
+			    sppp_auth_type_name(PPP_CHAP, h->type),
+			    h->ident, ntohs (h->len));
+			sppp_print_string((char*)name, name_len);
+			log(-1, " value-size=%d value=", value_len);
+			sppp_print_bytes(value, value_len);
+			log(-1, ">\n");
+		}
+		if (value_len != AUTHKEYLEN) {
+			if (debug)
+				log(LOG_DEBUG,
+				    SPP_FMT "chap bad hash value length: "
+				    "%d bytes, should be %d\n",
+				    SPP_ARGS(ifp), value_len,
+				    AUTHKEYLEN);
+			break;
+		}
+
+		MD5Init(&ctx);
+		MD5Update(&ctx, &h->ident, 1);
+		MD5Update(&ctx, sp->hisauth.secret,
+			  sppp_strnlen(sp->hisauth.secret, AUTHKEYLEN));
+		MD5Update(&ctx, sp->myauth.challenge, AUTHKEYLEN);
+		MD5Final(digest, &ctx);
+
+#define FAILMSG "Failed..."
+#define SUCCMSG "Welcome!"
+
+		if (value_len != sizeof digest ||
+		    bcmp(digest, value, value_len) != 0) {
+			/* action scn, tld */
+			sppp_auth_send(&chap, sp, CHAP_FAILURE, h->ident,
+				       sizeof(FAILMSG) - 1, (u_char *)FAILMSG,
+				       0);
+			chap.tld(sp);
+			break;
+		}
+		/* action sca, perhaps tlu */
+		if (sp->state[IDX_CHAP] == STATE_REQ_SENT ||
+		    sp->state[IDX_CHAP] == STATE_OPENED)
+			sppp_auth_send(&chap, sp, CHAP_SUCCESS, h->ident,
+				       sizeof(SUCCMSG) - 1, (u_char *)SUCCMSG,
+				       0);
+		if (sp->state[IDX_CHAP] == STATE_REQ_SENT) {
+			sppp_cp_change_state(&chap, sp, STATE_OPENED);
+			chap.tlu(sp);
+		}
+		break;
+
+	default:
+		/* Unknown CHAP packet type -- ignore. */
+		if (debug) {
+			log(LOG_DEBUG, SPP_FMT "chap unknown input(%s) "
+			    "<0x%x id=0x%xh len=%d",
+			    SPP_ARGS(ifp),
+			    sppp_state_name(sp->state[IDX_CHAP]),
+			    h->type, h->ident, ntohs(h->len));
+			sppp_print_bytes((u_char*)(h+1), len-4);
+			log(-1, ">\n");
+		}
+		break;
+
+	}
+}
+
+static void
+sppp_chap_init(struct sppp *sp)
+{
+	/* Chap doesn't have STATE_INITIAL at all. */
+	sp->state[IDX_CHAP] = STATE_CLOSED;
+	sp->fail_counter[IDX_CHAP] = 0;
+	sp->pp_seq[IDX_CHAP] = 0;
+	sp->pp_rseq[IDX_CHAP] = 0;
+ 	callout_init(&sp->ch[IDX_CHAP], CALLOUT_MPSAFE);
+}
+
+static void
+sppp_chap_open(struct sppp *sp)
+{
+	if (sp->myauth.proto == PPP_CHAP &&
+	    (sp->lcp.opts & (1 << LCP_OPT_AUTH_PROTO)) != 0) {
+		/* we are authenticator for CHAP, start it */
+		chap.scr(sp);
+		sp->rst_counter[IDX_CHAP] = sp->lcp.max_configure;
+		sppp_cp_change_state(&chap, sp, STATE_REQ_SENT);
+	}
+	/* nothing to be done if we are peer, await a challenge */
+}
+
+static void
+sppp_chap_close(struct sppp *sp)
+{
+	if (sp->state[IDX_CHAP] != STATE_CLOSED)
+		sppp_cp_change_state(&chap, sp, STATE_CLOSED);
+}
+
+static void
+sppp_chap_TO(void *cookie)
+{
+	struct sppp *sp = (struct sppp *)cookie;
+	STDDCL;
+	int s;
+
+	s = splimp();
+	SPPP_LOCK(sp);
+	if (debug)
+		log(LOG_DEBUG, SPP_FMT "chap TO(%s) rst_counter = %d\n",
+		    SPP_ARGS(ifp),
+		    sppp_state_name(sp->state[IDX_CHAP]),
+		    sp->rst_counter[IDX_CHAP]);
+
+	if (--sp->rst_counter[IDX_CHAP] < 0)
+		/* TO- event */
+		switch (sp->state[IDX_CHAP]) {
+		case STATE_REQ_SENT:
+			chap.tld(sp);
+			sppp_cp_change_state(&chap, sp, STATE_CLOSED);
+			break;
+		}
+	else
+		/* TO+ (or TO*) event */
+		switch (sp->state[IDX_CHAP]) {
+		case STATE_OPENED:
+			/* TO* event */
+			sp->rst_counter[IDX_CHAP] = sp->lcp.max_configure;
+			/* FALLTHROUGH */
+		case STATE_REQ_SENT:
+			chap.scr(sp);
+			/* sppp_cp_change_state() will restart the timer */
+			sppp_cp_change_state(&chap, sp, STATE_REQ_SENT);
+			break;
+		}
+
+	SPPP_UNLOCK(sp);
+	splx(s);
+}
+
+static void
+sppp_chap_tlu(struct sppp *sp)
+{
+	STDDCL;
+	int i, x;
+
+	i = 0;
+	sp->rst_counter[IDX_CHAP] = sp->lcp.max_configure;
+
+	/*
+	 * Some broken CHAP implementations (Conware CoNet, firmware
+	 * 4.0.?) don't want to re-authenticate their CHAP once the
+	 * initial challenge-response exchange has taken place.
+	 * Provide for an option to avoid rechallenges.
+	 */
+	if ((sp->hisauth.flags & AUTHFLAG_NORECHALLENGE) == 0) {
+		/*
+		 * Compute the re-challenge timeout.  This will yield
+		 * a number between 300 and 810 seconds.
+		 */
+		i = 300 + ((unsigned)(random() & 0xff00) >> 7);
+		callout_reset(&sp->ch[IDX_CHAP], i * hz, chap.TO, (void *)sp);
+	}
+
+	if (debug) {
+		log(LOG_DEBUG,
+		    SPP_FMT "chap %s, ",
+		    SPP_ARGS(ifp),
+		    sp->pp_phase == PHASE_NETWORK? "reconfirmed": "tlu");
+		if ((sp->hisauth.flags & AUTHFLAG_NORECHALLENGE) == 0)
+			log(-1, "next re-challenge in %d seconds\n", i);
+		else
+			log(-1, "re-challenging supressed\n");
+	}
+
+	x = splimp();
+	SPPP_LOCK(sp);
+	/* indicate to LCP that we need to be closed down */
+	sp->lcp.protos |= (1 << IDX_CHAP);
+
+	if (sp->pp_flags & PP_NEEDAUTH) {
+		/*
+		 * Remote is authenticator, but his auth proto didn't
+		 * complete yet.  Defer the transition to network
+		 * phase.
+		 */
+		SPPP_UNLOCK(sp);
+		splx(x);
+		return;
+	}
+	SPPP_UNLOCK(sp);
+	splx(x);
+
+	/*
+	 * If we are already in phase network, we are done here.  This
+	 * is the case if this is a dummy tlu event after a re-challenge.
+	 */
+	if (sp->pp_phase != PHASE_NETWORK)
+		sppp_phase_network(sp);
+}
+
+static void
+sppp_chap_tld(struct sppp *sp)
+{
+	STDDCL;
+
+	if (debug)
+		log(LOG_DEBUG, SPP_FMT "chap tld\n", SPP_ARGS(ifp));
+	callout_stop(&sp->ch[IDX_CHAP]);
+	sp->lcp.protos &= ~(1 << IDX_CHAP);
+
+	lcp.Close(sp);
+}
+
+static void
+sppp_chap_scr(struct sppp *sp)
+{
+	u_long *ch, seed;
+	u_char clen;
+
+	/* Compute random challenge. */
+	ch = (u_long *)sp->myauth.challenge;
+	read_random(&seed, sizeof seed);
+	ch[0] = seed ^ random();
+	ch[1] = seed ^ random();
+	ch[2] = seed ^ random();
+	ch[3] = seed ^ random();
+	clen = AUTHKEYLEN;
+
+	sp->confid[IDX_CHAP] = ++sp->pp_seq[IDX_CHAP];
+
+	sppp_auth_send(&chap, sp, CHAP_CHALLENGE, sp->confid[IDX_CHAP],
+		       sizeof clen, (const char *)&clen,
+		       (size_t)AUTHKEYLEN, sp->myauth.challenge,
+		       (size_t)sppp_strnlen(sp->myauth.name, AUTHNAMELEN),
+		       sp->myauth.name,
+		       0);
+}
+
+/*
+ *--------------------------------------------------------------------------*
+ *                                                                          *
+ *                        The PAP implementation.                           *
+ *                                                                          *
+ *--------------------------------------------------------------------------*
+ */
+/*
+ * For PAP, we need to keep a little state also if we are the peer, not the
+ * authenticator.  This is since we don't get a request to authenticate, but
+ * have to repeatedly authenticate ourself until we got a response (or the
+ * retry counter is expired).
+ */
+
+/*
+ * Handle incoming PAP packets.  */
+static void
+sppp_pap_input(struct sppp *sp, struct mbuf *m)
+{
+	STDDCL;
+	struct lcp_header *h;
+	int len, x;
+	u_char *name, *passwd, mlen;
+	int name_len, passwd_len;
+
+	len = m->m_pkthdr.len;
+	if (len < 5) {
+		if (debug)
+			log(LOG_DEBUG,
+			    SPP_FMT "pap invalid packet length: %d bytes\n",
+			    SPP_ARGS(ifp), len);
+		return;
+	}
+	h = mtod (m, struct lcp_header*);
+	if (len > ntohs (h->len))
+		len = ntohs (h->len);
+	switch (h->type) {
+	/* PAP request is my authproto */
+	case PAP_REQ:
+		name = 1 + (u_char*)(h+1);
+		name_len = name[-1];
+		passwd = name + name_len + 1;
+		if (name_len > len - 6 ||
+		    (passwd_len = passwd[-1]) > len - 6 - name_len) {
+			if (debug) {
+				log(LOG_DEBUG, SPP_FMT "pap corrupted input "
+				    "<%s id=0x%x len=%d",
+				    SPP_ARGS(ifp),
+				    sppp_auth_type_name(PPP_PAP, h->type),
+				    h->ident, ntohs(h->len));
+				sppp_print_bytes((u_char*)(h+1), len-4);
+				log(-1, ">\n");
+			}
+			break;
+		}
+		if (debug) {
+			log(LOG_DEBUG, SPP_FMT "pap input(%s) "
+			    "<%s id=0x%x len=%d name=",
+			    SPP_ARGS(ifp),
+			    sppp_state_name(sp->state[IDX_PAP]),
+			    sppp_auth_type_name(PPP_PAP, h->type),
+			    h->ident, ntohs(h->len));
+			sppp_print_string((char*)name, name_len);
+			log(-1, " passwd=");
+			sppp_print_string((char*)passwd, passwd_len);
+			log(-1, ">\n");
+		}
+		if (name_len != sppp_strnlen(sp->hisauth.name, AUTHNAMELEN) ||
+		    passwd_len != sppp_strnlen(sp->hisauth.secret, AUTHKEYLEN) ||
+		    bcmp(name, sp->hisauth.name, name_len) != 0 ||
+		    bcmp(passwd, sp->hisauth.secret, passwd_len) != 0) {
+			/* action scn, tld */
+			mlen = sizeof(FAILMSG) - 1;
+			sppp_auth_send(&pap, sp, PAP_NAK, h->ident,
+				       sizeof mlen, (const char *)&mlen,
+				       sizeof(FAILMSG) - 1, (u_char *)FAILMSG,
+				       0);
+			pap.tld(sp);
+			break;
+		}
+		/* action sca, perhaps tlu */
+		if (sp->state[IDX_PAP] == STATE_REQ_SENT ||
+		    sp->state[IDX_PAP] == STATE_OPENED) {
+			mlen = sizeof(SUCCMSG) - 1;
+			sppp_auth_send(&pap, sp, PAP_ACK, h->ident,
+				       sizeof mlen, (const char *)&mlen,
+				       sizeof(SUCCMSG) - 1, (u_char *)SUCCMSG,
+				       0);
+		}
+		if (sp->state[IDX_PAP] == STATE_REQ_SENT) {
+			sppp_cp_change_state(&pap, sp, STATE_OPENED);
+			pap.tlu(sp);
+		}
+		break;
+
+	/* ack and nak are his authproto */
+	case PAP_ACK:
+		callout_stop(&sp->pap_my_to_ch);
+		if (debug) {
+			log(LOG_DEBUG, SPP_FMT "pap success",
+			    SPP_ARGS(ifp));
+			name_len = *((char *)h);
+			if (len > 5 && name_len) {
+				log(-1, ": ");
+				sppp_print_string((char*)(h+1), name_len);
+			}
+			log(-1, "\n");
+		}
+		x = splimp();
+		SPPP_LOCK(sp);
+		sp->pp_flags &= ~PP_NEEDAUTH;
+		if (sp->myauth.proto == PPP_PAP &&
+		    (sp->lcp.opts & (1 << LCP_OPT_AUTH_PROTO)) &&
+		    (sp->lcp.protos & (1 << IDX_PAP)) == 0) {
+			/*
+			 * We are authenticator for PAP but didn't
+			 * complete yet.  Leave it to tlu to proceed
+			 * to network phase.
+			 */
+			SPPP_UNLOCK(sp);
+			splx(x);
+			break;
+		}
+		SPPP_UNLOCK(sp);
+		splx(x);
+		sppp_phase_network(sp);
+		break;
+
+	case PAP_NAK:
+		callout_stop (&sp->pap_my_to_ch);
+		if (debug) {
+			log(LOG_INFO, SPP_FMT "pap failure",
+			    SPP_ARGS(ifp));
+			name_len = *((char *)h);
+			if (len > 5 && name_len) {
+				log(-1, ": ");
+				sppp_print_string((char*)(h+1), name_len);
+			}
+			log(-1, "\n");
+		} else
+			log(LOG_INFO, SPP_FMT "pap failure\n",
+			    SPP_ARGS(ifp));
+		/* await LCP shutdown by authenticator */
+		break;
+
+	default:
+		/* Unknown PAP packet type -- ignore. */
+		if (debug) {
+			log(LOG_DEBUG, SPP_FMT "pap corrupted input "
+			    "<0x%x id=0x%x len=%d",
+			    SPP_ARGS(ifp),
+			    h->type, h->ident, ntohs(h->len));
+			sppp_print_bytes((u_char*)(h+1), len-4);
+			log(-1, ">\n");
+		}
+		break;
+
+	}
+}
+
+static void
+sppp_pap_init(struct sppp *sp)
+{
+	/* PAP doesn't have STATE_INITIAL at all. */
+	sp->state[IDX_PAP] = STATE_CLOSED;
+	sp->fail_counter[IDX_PAP] = 0;
+	sp->pp_seq[IDX_PAP] = 0;
+	sp->pp_rseq[IDX_PAP] = 0;
+ 	callout_init(&sp->ch[IDX_PAP], CALLOUT_MPSAFE);
+ 	callout_init(&sp->pap_my_to_ch, CALLOUT_MPSAFE);
+}
+
+static void
+sppp_pap_open(struct sppp *sp)
+{
+	if (sp->hisauth.proto == PPP_PAP &&
+	    (sp->lcp.opts & (1 << LCP_OPT_AUTH_PROTO)) != 0) {
+		/* we are authenticator for PAP, start our timer */
+		sp->rst_counter[IDX_PAP] = sp->lcp.max_configure;
+		sppp_cp_change_state(&pap, sp, STATE_REQ_SENT);
+	}
+	if (sp->myauth.proto == PPP_PAP) {
+		/* we are peer, send a request, and start a timer */
+		pap.scr(sp);
+		callout_reset(&sp->pap_my_to_ch, sp->lcp.timeout,
+			      sppp_pap_my_TO, (void *)sp);
+	}
+}
+
+static void
+sppp_pap_close(struct sppp *sp)
+{
+	if (sp->state[IDX_PAP] != STATE_CLOSED)
+		sppp_cp_change_state(&pap, sp, STATE_CLOSED);
+}
+
+/*
+ * That's the timeout routine if we are authenticator.  Since the
+ * authenticator is basically passive in PAP, we can't do much here.
+ */
+static void
+sppp_pap_TO(void *cookie)
+{
+	struct sppp *sp = (struct sppp *)cookie;
+	STDDCL;
+	int s;
+
+	s = splimp();
+	SPPP_LOCK(sp);
+	if (debug)
+		log(LOG_DEBUG, SPP_FMT "pap TO(%s) rst_counter = %d\n",
+		    SPP_ARGS(ifp),
+		    sppp_state_name(sp->state[IDX_PAP]),
+		    sp->rst_counter[IDX_PAP]);
+
+	if (--sp->rst_counter[IDX_PAP] < 0)
+		/* TO- event */
+		switch (sp->state[IDX_PAP]) {
+		case STATE_REQ_SENT:
+			pap.tld(sp);
+			sppp_cp_change_state(&pap, sp, STATE_CLOSED);
+			break;
+		}
+	else
+		/* TO+ event, not very much we could do */
+		switch (sp->state[IDX_PAP]) {
+		case STATE_REQ_SENT:
+			/* sppp_cp_change_state() will restart the timer */
+			sppp_cp_change_state(&pap, sp, STATE_REQ_SENT);
+			break;
+		}
+
+	SPPP_UNLOCK(sp);
+	splx(s);
+}
+
+/*
+ * That's the timeout handler if we are peer.  Since the peer is active,
+ * we need to retransmit our PAP request since it is apparently lost.
+ * XXX We should impose a max counter.
+ */
+static void
+sppp_pap_my_TO(void *cookie)
+{
+	struct sppp *sp = (struct sppp *)cookie;
+	STDDCL;
+
+	if (debug)
+		log(LOG_DEBUG, SPP_FMT "pap peer TO\n",
+		    SPP_ARGS(ifp));
+
+	SPPP_LOCK(sp);
+	pap.scr(sp);
+	SPPP_UNLOCK(sp);
+}
+
+static void
+sppp_pap_tlu(struct sppp *sp)
+{
+	STDDCL;
+	int x;
+
+	sp->rst_counter[IDX_PAP] = sp->lcp.max_configure;
+
+	if (debug)
+		log(LOG_DEBUG, SPP_FMT "%s tlu\n",
+		    SPP_ARGS(ifp), pap.name);
+
+	x = splimp();
+	SPPP_LOCK(sp);
+	/* indicate to LCP that we need to be closed down */
+	sp->lcp.protos |= (1 << IDX_PAP);
+
+	if (sp->pp_flags & PP_NEEDAUTH) {
+		/*
+		 * Remote is authenticator, but his auth proto didn't
+		 * complete yet.  Defer the transition to network
+		 * phase.
+		 */
+		SPPP_UNLOCK(sp);
+		splx(x);
+		return;
+	}
+	SPPP_UNLOCK(sp);
+	splx(x);
+	sppp_phase_network(sp);
+}
+
+static void
+sppp_pap_tld(struct sppp *sp)
+{
+	STDDCL;
+
+	if (debug)
+		log(LOG_DEBUG, SPP_FMT "pap tld\n", SPP_ARGS(ifp));
+	callout_stop (&sp->ch[IDX_PAP]);
+	callout_stop (&sp->pap_my_to_ch);
+	sp->lcp.protos &= ~(1 << IDX_PAP);
+
+	lcp.Close(sp);
+}
+
+static void
+sppp_pap_scr(struct sppp *sp)
+{
+	u_char idlen, pwdlen;
+
+	sp->confid[IDX_PAP] = ++sp->pp_seq[IDX_PAP];
+	pwdlen = sppp_strnlen(sp->myauth.secret, AUTHKEYLEN);
+	idlen = sppp_strnlen(sp->myauth.name, AUTHNAMELEN);
+
+	sppp_auth_send(&pap, sp, PAP_REQ, sp->confid[IDX_PAP],
+		       sizeof idlen, (const char *)&idlen,
+		       (size_t)idlen, sp->myauth.name,
+		       sizeof pwdlen, (const char *)&pwdlen,
+		       (size_t)pwdlen, sp->myauth.secret,
+		       0);
+}
+
+/*
+ * Random miscellaneous functions.
+ */
+
+/*
+ * Send a PAP or CHAP proto packet.
+ *
+ * Varadic function, each of the elements for the ellipsis is of type
+ * ``size_t mlen, const u_char *msg''.  Processing will stop iff
+ * mlen == 0.
+ * NOTE: never declare variadic functions with types subject to type
+ * promotion (i.e. u_char). This is asking for big trouble depending
+ * on the architecture you are on...
+ */
+
+static void
+sppp_auth_send(const struct cp *cp, struct sppp *sp,
+               unsigned int type, unsigned int id,
+	       ...)
+{
+	STDDCL;
+	struct ppp_header *h;
+	struct lcp_header *lh;
+	struct mbuf *m;
+	u_char *p;
+	int len;
+	unsigned int mlen;
+	const char *msg;
+	va_list ap;
+
+	MGETHDR (m, M_DONTWAIT, MT_DATA);
+	if (! m)
+		return;
+	m->m_pkthdr.rcvif = 0;
+
+	h = mtod (m, struct ppp_header*);
+	h->address = PPP_ALLSTATIONS;		/* broadcast address */
+	h->control = PPP_UI;			/* Unnumbered Info */
+	h->protocol = htons(cp->proto);
+
+	lh = (struct lcp_header*)(h + 1);
+	lh->type = type;
+	lh->ident = id;
+	p = (u_char*) (lh+1);
+
+	va_start(ap, id);
+	len = 0;
+
+	while ((mlen = (unsigned int)va_arg(ap, size_t)) != 0) {
+		msg = va_arg(ap, const char *);
+		len += mlen;
+		if (len > MHLEN - PPP_HEADER_LEN - LCP_HEADER_LEN) {
+			va_end(ap);
+			m_freem(m);
+			return;
+		}
+
+		bcopy(msg, p, mlen);
+		p += mlen;
+	}
+	va_end(ap);
+
+	m->m_pkthdr.len = m->m_len = PPP_HEADER_LEN + LCP_HEADER_LEN + len;
+	lh->len = htons (LCP_HEADER_LEN + len);
+
+	if (debug) {
+		log(LOG_DEBUG, SPP_FMT "%s output <%s id=0x%x len=%d",
+		    SPP_ARGS(ifp), cp->name,
+		    sppp_auth_type_name(cp->proto, lh->type),
+		    lh->ident, ntohs(lh->len));
+		sppp_print_bytes((u_char*) (lh+1), len);
+		log(-1, ">\n");
+	}
+	if (! IF_HANDOFF_ADJ(&sp->pp_cpq, m, ifp, 3))
+		ifp->if_oerrors++;
+}
+
+/*
+ * Flush interface queue.
+ */
+static void
+sppp_qflush(struct ifqueue *ifq)
+{
+	struct mbuf *m, *n;
+
+	n = ifq->ifq_head;
+	while ((m = n)) {
+		n = m->m_act;
+		m_freem (m);
+	}
+	ifq->ifq_head = 0;
+	ifq->ifq_tail = 0;
+	ifq->ifq_len = 0;
+}
+
+/*
+ * Send keepalive packets, every 10 seconds.
+ */
+static void
+sppp_keepalive(void *dummy)
+{
+	struct sppp *sp = (struct sppp*)dummy;
+	struct ifnet *ifp = SP2IFP(sp);
+	int s;
+
+	s = splimp();
+	SPPP_LOCK(sp);
+	/* Keepalive mode disabled or channel down? */
+	if (! (sp->pp_flags & PP_KEEPALIVE) ||
+	    ! (ifp->if_drv_flags & IFF_DRV_RUNNING))
+		goto out;
+
+	if (sp->pp_mode == PP_FR) {
+		sppp_fr_keepalive (sp);
+		goto out;
+	}
+
+	/* No keepalive in PPP mode if LCP not opened yet. */
+	if (sp->pp_mode != IFF_CISCO &&
+	    sp->pp_phase < PHASE_AUTHENTICATE)
+		goto out;
+
+	if (sp->pp_alivecnt == MAXALIVECNT) {
+		/* No keepalive packets got.  Stop the interface. */
+		printf (SPP_FMT "down\n", SPP_ARGS(ifp));
+		if_down (ifp);
+		sppp_qflush (&sp->pp_cpq);
+		if (sp->pp_mode != IFF_CISCO) {
+			/* XXX */
+			/* Shut down the PPP link. */
+			lcp.Down(sp);
+			/* Initiate negotiation. XXX */
+			lcp.Up(sp);
+		}
+	}
+	if (sp->pp_alivecnt <= MAXALIVECNT)
+		++sp->pp_alivecnt;
+	if (sp->pp_mode == IFF_CISCO)
+		sppp_cisco_send (sp, CISCO_KEEPALIVE_REQ,
+			 ++sp->pp_seq[IDX_LCP],	sp->pp_rseq[IDX_LCP]);
+	else if (sp->pp_phase >= PHASE_AUTHENTICATE) {
+		long nmagic = htonl (sp->lcp.magic);
+		sp->lcp.echoid = ++sp->pp_seq[IDX_LCP];
+		sppp_cp_send (sp, PPP_LCP, ECHO_REQ,
+			sp->lcp.echoid, 4, &nmagic);
+	}
+out:
+	SPPP_UNLOCK(sp);
+	splx(s);
+ 	callout_reset(&sp->keepalive_callout, hz * 10, sppp_keepalive,
+		      (void *)sp);
+}
+
+/*
+ * Get both IP addresses.
+ */
+void
+sppp_get_ip_addrs(struct sppp *sp, u_long *src, u_long *dst, u_long *srcmask)
+{
+	struct ifnet *ifp = SP2IFP(sp);
+	struct ifaddr *ifa;
+	struct sockaddr_in *si, *sm;
+	u_long ssrc, ddst;
+
+	sm = NULL;
+	ssrc = ddst = 0L;
+	/*
+	 * Pick the first AF_INET address from the list,
+	 * aliases don't make any sense on a p2p link anyway.
+	 */
+	si = 0;
+	if_addr_rlock(ifp);
+	TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link)
+		if (ifa->ifa_addr->sa_family == AF_INET) {
+			si = (struct sockaddr_in *)ifa->ifa_addr;
+			sm = (struct sockaddr_in *)ifa->ifa_netmask;
+			if (si)
+				break;
+		}
+	if (ifa) {
+		if (si && si->sin_addr.s_addr) {
+			ssrc = si->sin_addr.s_addr;
+			if (srcmask)
+				*srcmask = ntohl(sm->sin_addr.s_addr);
+		}
+
+		si = (struct sockaddr_in *)ifa->ifa_dstaddr;
+		if (si && si->sin_addr.s_addr)
+			ddst = si->sin_addr.s_addr;
+	}
+	if_addr_runlock(ifp);
+
+	if (dst) *dst = ntohl(ddst);
+	if (src) *src = ntohl(ssrc);
+}
+
+#ifdef INET
+/*
+ * Set my IP address.  Must be called at splimp.
+ */
+static void
+sppp_set_ip_addr(struct sppp *sp, u_long src)
+{
+	STDDCL;
+	struct ifaddr *ifa;
+	struct sockaddr_in *si;
+	struct in_ifaddr *ia;
+
+	/*
+	 * Pick the first AF_INET address from the list,
+	 * aliases don't make any sense on a p2p link anyway.
+	 */
+	si = 0;
+	if_addr_rlock(ifp);
+	TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
+		if (ifa->ifa_addr->sa_family == AF_INET) {
+			si = (struct sockaddr_in *)ifa->ifa_addr;
+			if (si != NULL) {
+				ifa_ref(ifa);
+				break;
+			}
+		}
+	}
+	if_addr_runlock(ifp);
+
+	if (ifa != NULL) {
+		int error;
+
+		/* delete old route */
+		error = rtinit(ifa, (int)RTM_DELETE, RTF_HOST);
+		if (debug && error) {
+			log(LOG_DEBUG, SPP_FMT "sppp_set_ip_addr: rtinit DEL failed, error=%d\n",
+		    		SPP_ARGS(ifp), error);
+		}
+
+		/* set new address */
+		si->sin_addr.s_addr = htonl(src);
+		ia = ifatoia(ifa);
+		IN_IFADDR_WLOCK();
+		LIST_REMOVE(ia, ia_hash);
+		LIST_INSERT_HEAD(INADDR_HASH(si->sin_addr.s_addr), ia, ia_hash);
+		IN_IFADDR_WUNLOCK();
+
+		/* add new route */
+		error = rtinit(ifa, (int)RTM_ADD, RTF_HOST);
+		if (debug && error) {
+			log(LOG_DEBUG, SPP_FMT "sppp_set_ip_addr: rtinit ADD failed, error=%d",
+		    		SPP_ARGS(ifp), error);
+		}
+		ifa_free(ifa);
+	}
+}
+#endif
+
+#ifdef INET6
+/*
+ * Get both IPv6 addresses.
+ */
+static void
+sppp_get_ip6_addrs(struct sppp *sp, struct in6_addr *src, struct in6_addr *dst,
+		   struct in6_addr *srcmask)
+{
+	struct ifnet *ifp = SP2IFP(sp);
+	struct ifaddr *ifa;
+	struct sockaddr_in6 *si, *sm;
+	struct in6_addr ssrc, ddst;
+
+	sm = NULL;
+	bzero(&ssrc, sizeof(ssrc));
+	bzero(&ddst, sizeof(ddst));
+	/*
+	 * Pick the first link-local AF_INET6 address from the list,
+	 * aliases don't make any sense on a p2p link anyway.
+	 */
+	si = NULL;
+	if_addr_rlock(ifp);
+	TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link)
+		if (ifa->ifa_addr->sa_family == AF_INET6) {
+			si = (struct sockaddr_in6 *)ifa->ifa_addr;
+			sm = (struct sockaddr_in6 *)ifa->ifa_netmask;
+			if (si && IN6_IS_ADDR_LINKLOCAL(&si->sin6_addr))
+				break;
+		}
+	if (ifa) {
+		if (si && !IN6_IS_ADDR_UNSPECIFIED(&si->sin6_addr)) {
+			bcopy(&si->sin6_addr, &ssrc, sizeof(ssrc));
+			if (srcmask) {
+				bcopy(&sm->sin6_addr, srcmask,
+				      sizeof(*srcmask));
+			}
+		}
+
+		si = (struct sockaddr_in6 *)ifa->ifa_dstaddr;
+		if (si && !IN6_IS_ADDR_UNSPECIFIED(&si->sin6_addr))
+			bcopy(&si->sin6_addr, &ddst, sizeof(ddst));
+	}
+
+	if (dst)
+		bcopy(&ddst, dst, sizeof(*dst));
+	if (src)
+		bcopy(&ssrc, src, sizeof(*src));
+	if_addr_runlock(ifp);
+}
+
+#ifdef IPV6CP_MYIFID_DYN
+/*
+ * Generate random ifid.
+ */
+static void
+sppp_gen_ip6_addr(struct sppp *sp, struct in6_addr *addr)
+{
+	/* TBD */
+}
+
+/*
+ * Set my IPv6 address.  Must be called at splimp.
+ */
+static void
+sppp_set_ip6_addr(struct sppp *sp, const struct in6_addr *src)
+{
+	STDDCL;
+	struct ifaddr *ifa;
+	struct sockaddr_in6 *sin6;
+
+	/*
+	 * Pick the first link-local AF_INET6 address from the list,
+	 * aliases don't make any sense on a p2p link anyway.
+	 */
+
+	sin6 = NULL;
+	if_addr_rlock(ifp);
+	TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
+		if (ifa->ifa_addr->sa_family == AF_INET6) {
+			sin6 = (struct sockaddr_in6 *)ifa->ifa_addr;
+			if (sin6 && IN6_IS_ADDR_LINKLOCAL(&sin6->sin6_addr)) {
+				ifa_ref(ifa);
+				break;
+			}
+		}
+	}
+	if_addr_runlock(ifp);
+
+	if (ifa != NULL) {
+		int error;
+		struct sockaddr_in6 new_sin6 = *sin6;
+
+		bcopy(src, &new_sin6.sin6_addr, sizeof(new_sin6.sin6_addr));
+		error = in6_ifinit(ifp, ifatoia6(ifa), &new_sin6, 1);
+		if (debug && error) {
+			log(LOG_DEBUG, SPP_FMT "sppp_set_ip6_addr: in6_ifinit "
+			    " failed, error=%d\n", SPP_ARGS(ifp), error);
+		}
+		ifa_free(ifa);
+	}
+}
+#endif
+
+/*
+ * Suggest a candidate address to be used by peer.
+ */
+static void
+sppp_suggest_ip6_addr(struct sppp *sp, struct in6_addr *suggest)
+{
+	struct in6_addr myaddr;
+	struct timeval tv;
+
+	sppp_get_ip6_addrs(sp, &myaddr, 0, 0);
+
+	myaddr.s6_addr[8] &= ~0x02;	/* u bit to "local" */
+	microtime(&tv);
+	if ((tv.tv_usec & 0xff) == 0 && (tv.tv_sec & 0xff) == 0) {
+		myaddr.s6_addr[14] ^= 0xff;
+		myaddr.s6_addr[15] ^= 0xff;
+	} else {
+		myaddr.s6_addr[14] ^= (tv.tv_usec & 0xff);
+		myaddr.s6_addr[15] ^= (tv.tv_sec & 0xff);
+	}
+	if (suggest)
+		bcopy(&myaddr, suggest, sizeof(myaddr));
+}
+#endif /*INET6*/
+
+static int
+sppp_params(struct sppp *sp, u_long cmd, void *data)
+{
+	u_long subcmd;
+	struct ifreq *ifr = (struct ifreq *)data;
+	struct spppreq *spr;
+	int rv = 0;
+
+	if ((spr = malloc(sizeof(struct spppreq), M_TEMP, M_NOWAIT)) == 0)
+		return (EAGAIN);
+	/*
+	 * ifr->ifr_data is supposed to point to a struct spppreq.
+	 * Check the cmd word first before attempting to fetch all the
+	 * data.
+	 */
+	if ((subcmd = fuword(ifr->ifr_data)) == -1) {
+		rv = EFAULT;
+		goto quit;
+	}
+
+	if (copyin((caddr_t)ifr->ifr_data, spr, sizeof(struct spppreq)) != 0) {
+		rv = EFAULT;
+		goto quit;
+	}
+
+	switch (subcmd) {
+	case (u_long)SPPPIOGDEFS:
+		if (cmd != SIOCGIFGENERIC) {
+			rv = EINVAL;
+			break;
+		}
+		/*
+		 * We copy over the entire current state, but clean
+		 * out some of the stuff we don't wanna pass up.
+		 * Remember, SIOCGIFGENERIC is unprotected, and can be
+		 * called by any user.  No need to ever get PAP or
+		 * CHAP secrets back to userland anyway.
+		 */
+		spr->defs.pp_phase = sp->pp_phase;
+		spr->defs.enable_vj = (sp->confflags & CONF_ENABLE_VJ) != 0;
+		spr->defs.enable_ipv6 = (sp->confflags & CONF_ENABLE_IPV6) != 0;
+		spr->defs.lcp = sp->lcp;
+		spr->defs.ipcp = sp->ipcp;
+		spr->defs.ipv6cp = sp->ipv6cp;
+		spr->defs.myauth = sp->myauth;
+		spr->defs.hisauth = sp->hisauth;
+		bzero(spr->defs.myauth.secret, AUTHKEYLEN);
+		bzero(spr->defs.myauth.challenge, AUTHKEYLEN);
+		bzero(spr->defs.hisauth.secret, AUTHKEYLEN);
+		bzero(spr->defs.hisauth.challenge, AUTHKEYLEN);
+		/*
+		 * Fixup the LCP timeout value to milliseconds so
+		 * spppcontrol doesn't need to bother about the value
+		 * of "hz".  We do the reverse calculation below when
+		 * setting it.
+		 */
+		spr->defs.lcp.timeout = sp->lcp.timeout * 1000 / hz;
+		rv = copyout(spr, (caddr_t)ifr->ifr_data,
+			     sizeof(struct spppreq));
+		break;
+
+	case (u_long)SPPPIOSDEFS:
+		if (cmd != SIOCSIFGENERIC) {
+			rv = EINVAL;
+			break;
+		}
+		/*
+		 * We have a very specific idea of which fields we
+		 * allow being passed back from userland, so to not
+		 * clobber our current state.  For one, we only allow
+		 * setting anything if LCP is in dead or establish
+		 * phase.  Once the authentication negotiations
+		 * started, the authentication settings must not be
+		 * changed again.  (The administrator can force an
+		 * ifconfig down in order to get LCP back into dead
+		 * phase.)
+		 *
+		 * Also, we only allow for authentication parameters to be
+		 * specified.
+		 *
+		 * XXX Should allow to set or clear pp_flags.
+		 *
+		 * Finally, if the respective authentication protocol to
+		 * be used is set differently than 0, but the secret is
+		 * passed as all zeros, we don't trash the existing secret.
+		 * This allows an administrator to change the system name
+		 * only without clobbering the secret (which he didn't get
+		 * back in a previous SPPPIOGDEFS call).  However, the
+		 * secrets are cleared if the authentication protocol is
+		 * reset to 0.  */
+		if (sp->pp_phase != PHASE_DEAD &&
+		    sp->pp_phase != PHASE_ESTABLISH) {
+			rv = EBUSY;
+			break;
+		}
+
+		if ((spr->defs.myauth.proto != 0 && spr->defs.myauth.proto != PPP_PAP &&
+		     spr->defs.myauth.proto != PPP_CHAP) ||
+		    (spr->defs.hisauth.proto != 0 && spr->defs.hisauth.proto != PPP_PAP &&
+		     spr->defs.hisauth.proto != PPP_CHAP)) {
+			rv = EINVAL;
+			break;
+		}
+
+		if (spr->defs.myauth.proto == 0)
+			/* resetting myauth */
+			bzero(&sp->myauth, sizeof sp->myauth);
+		else {
+			/* setting/changing myauth */
+			sp->myauth.proto = spr->defs.myauth.proto;
+			bcopy(spr->defs.myauth.name, sp->myauth.name, AUTHNAMELEN);
+			if (spr->defs.myauth.secret[0] != '\0')
+				bcopy(spr->defs.myauth.secret, sp->myauth.secret,
+				      AUTHKEYLEN);
+		}
+		if (spr->defs.hisauth.proto == 0)
+			/* resetting hisauth */
+			bzero(&sp->hisauth, sizeof sp->hisauth);
+		else {
+			/* setting/changing hisauth */
+			sp->hisauth.proto = spr->defs.hisauth.proto;
+			sp->hisauth.flags = spr->defs.hisauth.flags;
+			bcopy(spr->defs.hisauth.name, sp->hisauth.name, AUTHNAMELEN);
+			if (spr->defs.hisauth.secret[0] != '\0')
+				bcopy(spr->defs.hisauth.secret, sp->hisauth.secret,
+				      AUTHKEYLEN);
+		}
+		/* set LCP restart timer timeout */
+		if (spr->defs.lcp.timeout != 0)
+			sp->lcp.timeout = spr->defs.lcp.timeout * hz / 1000;
+		/* set VJ enable and IPv6 disable flags */
+#ifdef INET
+		if (spr->defs.enable_vj)
+			sp->confflags |= CONF_ENABLE_VJ;
+		else
+			sp->confflags &= ~CONF_ENABLE_VJ;
+#endif
+#ifdef INET6
+		if (spr->defs.enable_ipv6)
+			sp->confflags |= CONF_ENABLE_IPV6;
+		else
+			sp->confflags &= ~CONF_ENABLE_IPV6;
+#endif
+		break;
+
+	default:
+		rv = EINVAL;
+	}
+
+ quit:
+	free(spr, M_TEMP);
+
+	return (rv);
+}
+
+static void
+sppp_phase_network(struct sppp *sp)
+{
+	STDDCL;
+	int i;
+	u_long mask;
+
+	sp->pp_phase = PHASE_NETWORK;
+
+	if (debug)
+		log(LOG_DEBUG, SPP_FMT "phase %s\n", SPP_ARGS(ifp),
+		    sppp_phase_name(sp->pp_phase));
+
+	/* Notify NCPs now. */
+	for (i = 0; i < IDX_COUNT; i++)
+		if ((cps[i])->flags & CP_NCP)
+			(cps[i])->Open(sp);
+
+	/* Send Up events to all NCPs. */
+	for (i = 0, mask = 1; i < IDX_COUNT; i++, mask <<= 1)
+		if ((sp->lcp.protos & mask) && ((cps[i])->flags & CP_NCP))
+			(cps[i])->Up(sp);
+
+	/* if no NCP is starting, all this was in vain, close down */
+	sppp_lcp_check_and_close(sp);
+}
+
+
+static const char *
+sppp_cp_type_name(u_char type)
+{
+	static char buf[12];
+	switch (type) {
+	case CONF_REQ:   return "conf-req";
+	case CONF_ACK:   return "conf-ack";
+	case CONF_NAK:   return "conf-nak";
+	case CONF_REJ:   return "conf-rej";
+	case TERM_REQ:   return "term-req";
+	case TERM_ACK:   return "term-ack";
+	case CODE_REJ:   return "code-rej";
+	case PROTO_REJ:  return "proto-rej";
+	case ECHO_REQ:   return "echo-req";
+	case ECHO_REPLY: return "echo-reply";
+	case DISC_REQ:   return "discard-req";
+	}
+	snprintf (buf, sizeof(buf), "cp/0x%x", type);
+	return buf;
+}
+
+static const char *
+sppp_auth_type_name(u_short proto, u_char type)
+{
+	static char buf[12];
+	switch (proto) {
+	case PPP_CHAP:
+		switch (type) {
+		case CHAP_CHALLENGE:	return "challenge";
+		case CHAP_RESPONSE:	return "response";
+		case CHAP_SUCCESS:	return "success";
+		case CHAP_FAILURE:	return "failure";
+		}
+	case PPP_PAP:
+		switch (type) {
+		case PAP_REQ:		return "req";
+		case PAP_ACK:		return "ack";
+		case PAP_NAK:		return "nak";
+		}
+	}
+	snprintf (buf, sizeof(buf), "auth/0x%x", type);
+	return buf;
+}
+
+static const char *
+sppp_lcp_opt_name(u_char opt)
+{
+	static char buf[12];
+	switch (opt) {
+	case LCP_OPT_MRU:		return "mru";
+	case LCP_OPT_ASYNC_MAP:		return "async-map";
+	case LCP_OPT_AUTH_PROTO:	return "auth-proto";
+	case LCP_OPT_QUAL_PROTO:	return "qual-proto";
+	case LCP_OPT_MAGIC:		return "magic";
+	case LCP_OPT_PROTO_COMP:	return "proto-comp";
+	case LCP_OPT_ADDR_COMP:		return "addr-comp";
+	}
+	snprintf (buf, sizeof(buf), "lcp/0x%x", opt);
+	return buf;
+}
+
+#ifdef INET
+static const char *
+sppp_ipcp_opt_name(u_char opt)
+{
+	static char buf[12];
+	switch (opt) {
+	case IPCP_OPT_ADDRESSES:	return "addresses";
+	case IPCP_OPT_COMPRESSION:	return "compression";
+	case IPCP_OPT_ADDRESS:		return "address";
+	}
+	snprintf (buf, sizeof(buf), "ipcp/0x%x", opt);
+	return buf;
+}
+#endif
+
+#ifdef INET6
+static const char *
+sppp_ipv6cp_opt_name(u_char opt)
+{
+	static char buf[12];
+	switch (opt) {
+	case IPV6CP_OPT_IFID:		return "ifid";
+	case IPV6CP_OPT_COMPRESSION:	return "compression";
+	}
+	sprintf (buf, "0x%x", opt);
+	return buf;
+}
+#endif
+
+static const char *
+sppp_state_name(int state)
+{
+	switch (state) {
+	case STATE_INITIAL:	return "initial";
+	case STATE_STARTING:	return "starting";
+	case STATE_CLOSED:	return "closed";
+	case STATE_STOPPED:	return "stopped";
+	case STATE_CLOSING:	return "closing";
+	case STATE_STOPPING:	return "stopping";
+	case STATE_REQ_SENT:	return "req-sent";
+	case STATE_ACK_RCVD:	return "ack-rcvd";
+	case STATE_ACK_SENT:	return "ack-sent";
+	case STATE_OPENED:	return "opened";
+	}
+	return "illegal";
+}
+
+static const char *
+sppp_phase_name(enum ppp_phase phase)
+{
+	switch (phase) {
+	case PHASE_DEAD:	return "dead";
+	case PHASE_ESTABLISH:	return "establish";
+	case PHASE_TERMINATE:	return "terminate";
+	case PHASE_AUTHENTICATE: return "authenticate";
+	case PHASE_NETWORK:	return "network";
+	}
+	return "illegal";
+}
+
+static const char *
+sppp_proto_name(u_short proto)
+{
+	static char buf[12];
+	switch (proto) {
+	case PPP_LCP:	return "lcp";
+	case PPP_IPCP:	return "ipcp";
+	case PPP_PAP:	return "pap";
+	case PPP_CHAP:	return "chap";
+	case PPP_IPV6CP: return "ipv6cp";
+	}
+	snprintf(buf, sizeof(buf), "proto/0x%x", (unsigned)proto);
+	return buf;
+}
+
+static void
+sppp_print_bytes(const u_char *p, u_short len)
+{
+	if (len)
+		log(-1, " %*D", len, p, "-");
+}
+
+static void
+sppp_print_string(const char *p, u_short len)
+{
+	u_char c;
+
+	while (len-- > 0) {
+		c = *p++;
+		/*
+		 * Print only ASCII chars directly.  RFC 1994 recommends
+		 * using only them, but we don't rely on it.  */
+		if (c < ' ' || c > '~')
+			log(-1, "\\x%x", c);
+		else
+			log(-1, "%c", c);
+	}
+}
+
+#ifdef INET
+static const char *
+sppp_dotted_quad(u_long addr)
+{
+	static char s[16];
+	sprintf(s, "%d.%d.%d.%d",
+		(int)((addr >> 24) & 0xff),
+		(int)((addr >> 16) & 0xff),
+		(int)((addr >> 8) & 0xff),
+		(int)(addr & 0xff));
+	return s;
+}
+#endif
+
+static int
+sppp_strnlen(u_char *p, int max)
+{
+	int len;
+
+	for (len = 0; len < max && *p; ++p)
+		++len;
+	return len;
+}
+
+/* a dummy, used to drop uninteresting events */
+static void
+sppp_null(struct sppp *unused)
+{
+	/* do just nothing */
+}