/* * ipcp.c - PPP IP Control Protocol. * * Copyright (c) 1989 Carnegie Mellon University. * All rights reserved. * * Redistribution and use in source and binary forms are permitted * provided that the above copyright notice and this paragraph are * duplicated in all such forms and that any documentation, * advertising materials, and other materials related to such * distribution and use acknowledge that the software was developed * by Carnegie Mellon University. The name of the * University may not be used to endorse or promote products derived * from this software without specific prior written permission. * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE. */ #define RCSID "$Id$" /* * TODO: */ #include #include #include #include #include #include #include #include #include #include "pppd.h" #include "fsm.h" #include "ipcp.h" #include "pathnames.h" static const char rcsid[] = RCSID; /* global vars */ ipcp_options ipcp_wantoptions[NUM_PPP]; /* Options that we want to request */ ipcp_options ipcp_gotoptions[NUM_PPP]; /* Options that peer ack'd */ ipcp_options ipcp_allowoptions[NUM_PPP]; /* Options we allow peer to request */ ipcp_options ipcp_hisoptions[NUM_PPP]; /* Options that we ack'd */ bool disable_defaultip = 0; /* Don't use hostname for default IP adrs */ /* Hook for a plugin to know when IP protocol has come up */ void (*ip_up_hook) __P((void)) = NULL; /* Hook for a plugin to know when IP protocol has come down */ void (*ip_down_hook) __P((void)) = NULL; /* local vars */ static int default_route_set[NUM_PPP]; /* Have set up a default route */ static int proxy_arp_set[NUM_PPP]; /* Have created proxy arp entry */ static bool usepeerdns; /* Ask peer for DNS addrs */ static int ipcp_is_up; /* have called np_up() */ /* * Callbacks for fsm code. (CI = Configuration Information) */ static void ipcp_resetci __P((fsm *)); /* Reset our CI */ static int ipcp_cilen __P((fsm *)); /* Return length of our CI */ static void ipcp_addci __P((fsm *, u_char *, int *)); /* Add our CI */ static int ipcp_ackci __P((fsm *, u_char *, int)); /* Peer ack'd our CI */ static int ipcp_nakci __P((fsm *, u_char *, int)); /* Peer nak'd our CI */ static int ipcp_rejci __P((fsm *, u_char *, int)); /* Peer rej'd our CI */ static int ipcp_reqci __P((fsm *, u_char *, int *, int)); /* Rcv CI */ static void ipcp_up __P((fsm *)); /* We're UP */ static void ipcp_down __P((fsm *)); /* We're DOWN */ static void ipcp_finished __P((fsm *)); /* Don't need lower layer */ fsm ipcp_fsm[NUM_PPP]; /* IPCP fsm structure */ static fsm_callbacks ipcp_callbacks = { /* IPCP callback routines */ ipcp_resetci, /* Reset our Configuration Information */ ipcp_cilen, /* Length of our Configuration Information */ ipcp_addci, /* Add our Configuration Information */ ipcp_ackci, /* ACK our Configuration Information */ ipcp_nakci, /* NAK our Configuration Information */ ipcp_rejci, /* Reject our Configuration Information */ ipcp_reqci, /* Request peer's Configuration Information */ ipcp_up, /* Called when fsm reaches OPENED state */ ipcp_down, /* Called when fsm leaves OPENED state */ NULL, /* Called when we want the lower layer up */ ipcp_finished, /* Called when we want the lower layer down */ NULL, /* Called when Protocol-Reject received */ NULL, /* Retransmission is necessary */ NULL, /* Called to handle protocol-specific codes */ "IPCP" /* String name of protocol */ }; /* * Command-line options. */ static int setvjslots __P((char **)); static int setdnsaddr __P((char **)); static int setwinsaddr __P((char **)); static option_t ipcp_option_list[] = { { "noip", o_bool, &ipcp_protent.enabled_flag, "Disable IP and IPCP" }, { "-ip", o_bool, &ipcp_protent.enabled_flag, "Disable IP and IPCP" }, { "novj", o_bool, &ipcp_wantoptions[0].neg_vj, "Disable VJ compression", OPT_A2COPY, &ipcp_allowoptions[0].neg_vj }, { "-vj", o_bool, &ipcp_wantoptions[0].neg_vj, "Disable VJ compression", OPT_A2COPY, &ipcp_allowoptions[0].neg_vj }, { "novjccomp", o_bool, &ipcp_wantoptions[0].cflag, "Disable VJ connection-ID compression", OPT_A2COPY, &ipcp_allowoptions[0].cflag }, { "-vjccomp", o_bool, &ipcp_wantoptions[0].cflag, "Disable VJ connection-ID compression", OPT_A2COPY, &ipcp_allowoptions[0].cflag }, { "vj-max-slots", 1, setvjslots, "Set maximum VJ header slots" }, { "ipcp-accept-local", o_bool, &ipcp_wantoptions[0].accept_local, "Accept peer's address for us", 1 }, { "ipcp-accept-remote", o_bool, &ipcp_wantoptions[0].accept_remote, "Accept peer's address for it", 1 }, { "ipparam", o_string, &ipparam, "Set ip script parameter" }, { "noipdefault", o_bool, &disable_defaultip, "Don't use name for default IP adrs", 1 }, { "ms-dns", 1, setdnsaddr, "DNS address for the peer's use" }, { "ms-wins", 1, setwinsaddr, "Nameserver for SMB over TCP/IP for peer" }, { "ipcp-restart", o_int, &ipcp_fsm[0].timeouttime, "Set timeout for IPCP" }, { "ipcp-max-terminate", o_int, &ipcp_fsm[0].maxtermtransmits, "Set max #xmits for term-reqs" }, { "ipcp-max-configure", o_int, &ipcp_fsm[0].maxconfreqtransmits, "Set max #xmits for conf-reqs" }, { "ipcp-max-failure", o_int, &ipcp_fsm[0].maxnakloops, "Set max #conf-naks for IPCP" }, { "defaultroute", o_bool, &ipcp_wantoptions[0].default_route, "Add default route", OPT_ENABLE|1, &ipcp_allowoptions[0].default_route }, { "nodefaultroute", o_bool, &ipcp_allowoptions[0].default_route, "disable defaultroute option", OPT_A2COPY, &ipcp_wantoptions[0].default_route }, { "-defaultroute", o_bool, &ipcp_allowoptions[0].default_route, "disable defaultroute option", OPT_A2COPY, &ipcp_wantoptions[0].default_route }, { "proxyarp", o_bool, &ipcp_wantoptions[0].proxy_arp, "Add proxy ARP entry", OPT_ENABLE|1, &ipcp_allowoptions[0].proxy_arp }, { "noproxyarp", o_bool, &ipcp_allowoptions[0].proxy_arp, "disable proxyarp option", OPT_A2COPY, &ipcp_wantoptions[0].proxy_arp }, { "-proxyarp", o_bool, &ipcp_allowoptions[0].proxy_arp, "disable proxyarp option", OPT_A2COPY, &ipcp_wantoptions[0].proxy_arp }, { "usepeerdns", o_bool, &usepeerdns, "Ask peer for DNS address(es)", 1 }, { NULL } }; /* * Protocol entry points from main code. */ static void ipcp_init __P((int)); static void ipcp_open __P((int)); static void ipcp_close __P((int, char *)); static void ipcp_lowerup __P((int)); static void ipcp_lowerdown __P((int)); static void ipcp_input __P((int, u_char *, int)); static void ipcp_protrej __P((int)); static int ipcp_printpkt __P((u_char *, int, void (*) __P((void *, char *, ...)), void *)); static void ip_check_options __P((void)); static int ip_demand_conf __P((int)); static int ip_active_pkt __P((u_char *, int)); static void create_resolv __P((u_int32_t, u_int32_t)); struct protent ipcp_protent = { PPP_IPCP, ipcp_init, ipcp_input, ipcp_protrej, ipcp_lowerup, ipcp_lowerdown, ipcp_open, ipcp_close, ipcp_printpkt, NULL, 1, "IPCP", "IP", ipcp_option_list, ip_check_options, ip_demand_conf, ip_active_pkt }; static void ipcp_clear_addrs __P((int, u_int32_t, u_int32_t)); /* * Lengths of configuration options. */ #define CILEN_VOID 2 #define CILEN_COMPRESS 4 /* min length for compression protocol opt. */ #define CILEN_VJ 6 /* length for RFC1332 Van-Jacobson opt. */ #define CILEN_ADDR 6 /* new-style single address option */ #define CILEN_ADDRS 10 /* old-style dual address option */ #define CODENAME(x) ((x) == CONFACK ? "ACK" : \ (x) == CONFNAK ? "NAK" : "REJ") /* * Make a string representation of a network IP address. */ char * ip_ntoa(ipaddr) u_int32_t ipaddr; { static char b[64]; slprintf(b, sizeof(b), "%I", ipaddr); return b; } /* * Option parsing. */ /* * setvjslots - set maximum number of connection slots for VJ compression */ static int setvjslots(argv) char **argv; { int value; if (!int_option(*argv, &value)) return 0; if (value < 2 || value > 16) { option_error("vj-max-slots value must be between 2 and 16"); return 0; } ipcp_wantoptions [0].maxslotindex = ipcp_allowoptions[0].maxslotindex = value - 1; return 1; } /* * setdnsaddr - set the dns address(es) */ static int setdnsaddr(argv) char **argv; { u_int32_t dns; struct hostent *hp; dns = inet_addr(*argv); if (dns == (u_int32_t) -1) { if ((hp = gethostbyname(*argv)) == NULL) { option_error("invalid address parameter '%s' for ms-dns option", *argv); return 0; } dns = *(u_int32_t *)hp->h_addr; } /* if there is no primary then update it. */ if (ipcp_allowoptions[0].dnsaddr[0] == 0) ipcp_allowoptions[0].dnsaddr[0] = dns; /* always set the secondary address value to the same value. */ ipcp_allowoptions[0].dnsaddr[1] = dns; return (1); } /* * setwinsaddr - set the wins address(es) * This is primrarly used with the Samba package under UNIX or for pointing * the caller to the existing WINS server on a Windows NT platform. */ static int setwinsaddr(argv) char **argv; { u_int32_t wins; struct hostent *hp; wins = inet_addr(*argv); if (wins == (u_int32_t) -1) { if ((hp = gethostbyname(*argv)) == NULL) { option_error("invalid address parameter '%s' for ms-wins option", *argv); return 0; } wins = *(u_int32_t *)hp->h_addr; } /* if there is no primary then update it. */ if (ipcp_allowoptions[0].winsaddr[0] == 0) ipcp_allowoptions[0].winsaddr[0] = wins; /* always set the secondary address value to the same value. */ ipcp_allowoptions[0].winsaddr[1] = wins; return (1); } /* * ipcp_init - Initialize IPCP. */ static void ipcp_init(unit) int unit; { fsm *f = &ipcp_fsm[unit]; ipcp_options *wo = &ipcp_wantoptions[unit]; ipcp_options *ao = &ipcp_allowoptions[unit]; f->unit = unit; f->protocol = PPP_IPCP; f->callbacks = &ipcp_callbacks; fsm_init(&ipcp_fsm[unit]); memset(wo, 0, sizeof(*wo)); memset(ao, 0, sizeof(*ao)); wo->neg_addr = 1; wo->neg_vj = 1; wo->vj_protocol = IPCP_VJ_COMP; wo->maxslotindex = MAX_STATES - 1; /* really max index */ wo->cflag = 1; /* max slots and slot-id compression are currently hardwired in */ /* ppp_if.c to 16 and 1, this needs to be changed (among other */ /* things) gmc */ ao->neg_addr = 1; ao->neg_vj = 1; ao->maxslotindex = MAX_STATES - 1; ao->cflag = 1; /* * XXX These control whether the user may use the proxyarp * and defaultroute options. */ ao->proxy_arp = 1; ao->default_route = 1; } /* * ipcp_open - IPCP is allowed to come up. */ static void ipcp_open(unit) int unit; { fsm_open(&ipcp_fsm[unit]); } /* * ipcp_close - Take IPCP down. */ static void ipcp_close(unit, reason) int unit; char *reason; { fsm_close(&ipcp_fsm[unit], reason); } /* * ipcp_lowerup - The lower layer is up. */ static void ipcp_lowerup(unit) int unit; { fsm_lowerup(&ipcp_fsm[unit]); } /* * ipcp_lowerdown - The lower layer is down. */ static void ipcp_lowerdown(unit) int unit; { fsm_lowerdown(&ipcp_fsm[unit]); } /* * ipcp_input - Input IPCP packet. */ static void ipcp_input(unit, p, len) int unit; u_char *p; int len; { fsm_input(&ipcp_fsm[unit], p, len); } /* * ipcp_protrej - A Protocol-Reject was received for IPCP. * * Pretend the lower layer went down, so we shut up. */ static void ipcp_protrej(unit) int unit; { fsm_lowerdown(&ipcp_fsm[unit]); } /* * ipcp_resetci - Reset our CI. * Called by fsm_sconfreq, Send Configure Request. */ static void ipcp_resetci(f) fsm *f; { ipcp_options *wo = &ipcp_wantoptions[f->unit]; ipcp_options *go = &ipcp_gotoptions[f->unit]; wo->req_addr = wo->neg_addr && ipcp_allowoptions[f->unit].neg_addr; if (wo->ouraddr == 0 || disable_defaultip) wo->accept_local = 1; if (wo->hisaddr == 0) wo->accept_remote = 1; wo->req_dns1 = usepeerdns; /* Request DNS addresses from the peer */ wo->req_dns2 = usepeerdns; *go = *wo; if (disable_defaultip) go->ouraddr = 0; } /* * ipcp_cilen - Return length of our CI. * Called by fsm_sconfreq, Send Configure Request. */ static int ipcp_cilen(f) fsm *f; { ipcp_options *go = &ipcp_gotoptions[f->unit]; ipcp_options *wo = &ipcp_wantoptions[f->unit]; ipcp_options *ho = &ipcp_hisoptions[f->unit]; #define LENCIVJ(neg, old) (neg ? (old? CILEN_COMPRESS : CILEN_VJ) : 0) #define LENCIADDR(neg, old) (neg ? (old? CILEN_ADDRS : CILEN_ADDR) : 0) #define LENCIDNS(neg) (neg ? (CILEN_ADDR) : 0) /* * First see if we want to change our options to the old * forms because we have received old forms from the peer. */ if (wo->neg_addr && !go->neg_addr && !go->old_addrs) { /* use the old style of address negotiation */ go->neg_addr = 1; go->old_addrs = 1; } if (wo->neg_vj && !go->neg_vj && !go->old_vj) { /* try an older style of VJ negotiation */ /* use the old style only if the peer did */ if (ho->neg_vj && ho->old_vj) { go->neg_vj = 1; go->old_vj = 1; go->vj_protocol = ho->vj_protocol; } } return (LENCIADDR(go->neg_addr, go->old_addrs) + LENCIVJ(go->neg_vj, go->old_vj) + LENCIDNS(go->req_dns1) + LENCIDNS(go->req_dns2)) ; } /* * ipcp_addci - Add our desired CIs to a packet. * Called by fsm_sconfreq, Send Configure Request. */ static void ipcp_addci(f, ucp, lenp) fsm *f; u_char *ucp; int *lenp; { ipcp_options *go = &ipcp_gotoptions[f->unit]; int len = *lenp; #define ADDCIVJ(opt, neg, val, old, maxslotindex, cflag) \ if (neg) { \ int vjlen = old? CILEN_COMPRESS : CILEN_VJ; \ if (len >= vjlen) { \ PUTCHAR(opt, ucp); \ PUTCHAR(vjlen, ucp); \ PUTSHORT(val, ucp); \ if (!old) { \ PUTCHAR(maxslotindex, ucp); \ PUTCHAR(cflag, ucp); \ } \ len -= vjlen; \ } else \ neg = 0; \ } #define ADDCIADDR(opt, neg, old, val1, val2) \ if (neg) { \ int addrlen = (old? CILEN_ADDRS: CILEN_ADDR); \ if (len >= addrlen) { \ u_int32_t l; \ PUTCHAR(opt, ucp); \ PUTCHAR(addrlen, ucp); \ l = ntohl(val1); \ PUTLONG(l, ucp); \ if (old) { \ l = ntohl(val2); \ PUTLONG(l, ucp); \ } \ len -= addrlen; \ } else \ neg = 0; \ } #define ADDCIDNS(opt, neg, addr) \ if (neg) { \ if (len >= CILEN_ADDR) { \ u_int32_t l; \ PUTCHAR(opt, ucp); \ PUTCHAR(CILEN_ADDR, ucp); \ l = ntohl(addr); \ PUTLONG(l, ucp); \ len -= CILEN_ADDR; \ } else \ neg = 0; \ } ADDCIADDR((go->old_addrs? CI_ADDRS: CI_ADDR), go->neg_addr, go->old_addrs, go->ouraddr, go->hisaddr); ADDCIVJ(CI_COMPRESSTYPE, go->neg_vj, go->vj_protocol, go->old_vj, go->maxslotindex, go->cflag); ADDCIDNS(CI_MS_DNS1, go->req_dns1, go->dnsaddr[0]); ADDCIDNS(CI_MS_DNS2, go->req_dns2, go->dnsaddr[1]); *lenp -= len; } /* * ipcp_ackci - Ack our CIs. * Called by fsm_rconfack, Receive Configure ACK. * * Returns: * 0 - Ack was bad. * 1 - Ack was good. */ static int ipcp_ackci(f, p, len) fsm *f; u_char *p; int len; { ipcp_options *go = &ipcp_gotoptions[f->unit]; u_short cilen, citype, cishort; u_int32_t cilong; u_char cimaxslotindex, cicflag; /* * CIs must be in exactly the same order that we sent... * Check packet length and CI length at each step. * If we find any deviations, then this packet is bad. */ #define ACKCIVJ(opt, neg, val, old, maxslotindex, cflag) \ if (neg) { \ int vjlen = old? CILEN_COMPRESS : CILEN_VJ; \ if ((len -= vjlen) < 0) \ goto bad; \ GETCHAR(citype, p); \ GETCHAR(cilen, p); \ if (cilen != vjlen || \ citype != opt) \ goto bad; \ GETSHORT(cishort, p); \ if (cishort != val) \ goto bad; \ if (!old) { \ GETCHAR(cimaxslotindex, p); \ if (cimaxslotindex != maxslotindex) \ goto bad; \ GETCHAR(cicflag, p); \ if (cicflag != cflag) \ goto bad; \ } \ } #define ACKCIADDR(opt, neg, old, val1, val2) \ if (neg) { \ int addrlen = (old? CILEN_ADDRS: CILEN_ADDR); \ u_int32_t l; \ if ((len -= addrlen) < 0) \ goto bad; \ GETCHAR(citype, p); \ GETCHAR(cilen, p); \ if (cilen != addrlen || \ citype != opt) \ goto bad; \ GETLONG(l, p); \ cilong = htonl(l); \ if (val1 != cilong) \ goto bad; \ if (old) { \ GETLONG(l, p); \ cilong = htonl(l); \ if (val2 != cilong) \ goto bad; \ } \ } #define ACKCIDNS(opt, neg, addr) \ if (neg) { \ u_int32_t l; \ if ((len -= CILEN_ADDR) < 0) \ goto bad; \ GETCHAR(citype, p); \ GETCHAR(cilen, p); \ if (cilen != CILEN_ADDR || citype != opt) \ goto bad; \ GETLONG(l, p); \ cilong = htonl(l); \ if (addr != cilong) \ goto bad; \ } ACKCIADDR((go->old_addrs? CI_ADDRS: CI_ADDR), go->neg_addr, go->old_addrs, go->ouraddr, go->hisaddr); ACKCIVJ(CI_COMPRESSTYPE, go->neg_vj, go->vj_protocol, go->old_vj, go->maxslotindex, go->cflag); ACKCIDNS(CI_MS_DNS1, go->req_dns1, go->dnsaddr[0]); ACKCIDNS(CI_MS_DNS2, go->req_dns2, go->dnsaddr[1]); /* * If there are any remaining CIs, then this packet is bad. */ if (len != 0) goto bad; return (1); bad: IPCPDEBUG(("ipcp_ackci: received bad Ack!")); return (0); } /* * ipcp_nakci - Peer has sent a NAK for some of our CIs. * This should not modify any state if the Nak is bad * or if IPCP is in the OPENED state. * Calback from fsm_rconfnakrej - Receive Configure-Nak or Configure-Reject. * * Returns: * 0 - Nak was bad. * 1 - Nak was good. */ static int ipcp_nakci(f, p, len) fsm *f; u_char *p; int len; { ipcp_options *go = &ipcp_gotoptions[f->unit]; u_char cimaxslotindex, cicflag; u_char citype, cilen, *next; u_short cishort; u_int32_t ciaddr1, ciaddr2, l, cidnsaddr; ipcp_options no; /* options we've seen Naks for */ ipcp_options try; /* options to request next time */ BZERO(&no, sizeof(no)); try = *go; /* * Any Nak'd CIs must be in exactly the same order that we sent. * Check packet length and CI length at each step. * If we find any deviations, then this packet is bad. */ #define NAKCIADDR(opt, neg, old, code) \ if (go->neg && \ len >= (cilen = (old? CILEN_ADDRS: CILEN_ADDR)) && \ p[1] == cilen && \ p[0] == opt) { \ len -= cilen; \ INCPTR(2, p); \ GETLONG(l, p); \ ciaddr1 = htonl(l); \ if (old) { \ GETLONG(l, p); \ ciaddr2 = htonl(l); \ no.old_addrs = 1; \ } else \ ciaddr2 = 0; \ no.neg = 1; \ code \ } #define NAKCIVJ(opt, neg, code) \ if (go->neg && \ ((cilen = p[1]) == CILEN_COMPRESS || cilen == CILEN_VJ) && \ len >= cilen && \ p[0] == opt) { \ len -= cilen; \ INCPTR(2, p); \ GETSHORT(cishort, p); \ no.neg = 1; \ code \ } #define NAKCIDNS(opt, neg, code) \ if (go->neg && \ ((cilen = p[1]) == CILEN_ADDR) && \ len >= cilen && \ p[0] == opt) { \ len -= cilen; \ INCPTR(2, p); \ GETLONG(l, p); \ cidnsaddr = htonl(l); \ no.neg = 1; \ code \ } /* * Accept the peer's idea of {our,his} address, if different * from our idea, only if the accept_{local,remote} flag is set. */ NAKCIADDR((go->old_addrs? CI_ADDRS: CI_ADDR), neg_addr, go->old_addrs, if (go->accept_local && ciaddr1) { /* Do we know our address? */ try.ouraddr = ciaddr1; } if (go->accept_remote && ciaddr2) { /* Does he know his? */ try.hisaddr = ciaddr2; } ); /* * Accept the peer's value of maxslotindex provided that it * is less than what we asked for. Turn off slot-ID compression * if the peer wants. Send old-style compress-type option if * the peer wants. */ NAKCIVJ(CI_COMPRESSTYPE, neg_vj, if (cilen == CILEN_VJ) { GETCHAR(cimaxslotindex, p); GETCHAR(cicflag, p); if (cishort == IPCP_VJ_COMP) { try.old_vj = 0; if (cimaxslotindex < go->maxslotindex) try.maxslotindex = cimaxslotindex; if (!cicflag) try.cflag = 0; } else { try.neg_vj = 0; } } else { if (cishort == IPCP_VJ_COMP || cishort == IPCP_VJ_COMP_OLD) { try.old_vj = 1; try.vj_protocol = cishort; } else { try.neg_vj = 0; } } ); NAKCIDNS(CI_MS_DNS1, req_dns1, try.dnsaddr[0] = cidnsaddr; ); NAKCIDNS(CI_MS_DNS2, req_dns2, try.dnsaddr[1] = cidnsaddr; ); /* * There may be remaining CIs, if the peer is requesting negotiation * on an option that we didn't include in our request packet. * If they want to negotiate about IP addresses, we comply. * If they want us to ask for compression, we refuse. */ while (len > CILEN_VOID) { GETCHAR(citype, p); GETCHAR(cilen, p); if( (len -= cilen) < 0 ) goto bad; next = p + cilen - 2; switch (citype) { case CI_COMPRESSTYPE: if (go->neg_vj || no.neg_vj || (cilen != CILEN_VJ && cilen != CILEN_COMPRESS)) goto bad; no.neg_vj = 1; break; case CI_ADDRS: if ((go->neg_addr && go->old_addrs) || no.old_addrs || cilen != CILEN_ADDRS) goto bad; try.neg_addr = 1; try.old_addrs = 1; GETLONG(l, p); ciaddr1 = htonl(l); if (ciaddr1 && go->accept_local) try.ouraddr = ciaddr1; GETLONG(l, p); ciaddr2 = htonl(l); if (ciaddr2 && go->accept_remote) try.hisaddr = ciaddr2; no.old_addrs = 1; break; case CI_ADDR: if (go->neg_addr || no.neg_addr || cilen != CILEN_ADDR) goto bad; try.old_addrs = 0; GETLONG(l, p); ciaddr1 = htonl(l); if (ciaddr1 && go->accept_local) try.ouraddr = ciaddr1; if (try.ouraddr != 0) try.neg_addr = 1; no.neg_addr = 1; break; } p = next; } /* * OK, the Nak is good. Now we can update state. * If there are any remaining options, we ignore them. */ if (f->state != OPENED) *go = try; return 1; bad: IPCPDEBUG(("ipcp_nakci: received bad Nak!")); return 0; } /* * ipcp_rejci - Reject some of our CIs. * Callback from fsm_rconfnakrej. */ static int ipcp_rejci(f, p, len) fsm *f; u_char *p; int len; { ipcp_options *go = &ipcp_gotoptions[f->unit]; u_char cimaxslotindex, ciflag, cilen; u_short cishort; u_int32_t cilong; ipcp_options try; /* options to request next time */ try = *go; /* * Any Rejected CIs must be in exactly the same order that we sent. * Check packet length and CI length at each step. * If we find any deviations, then this packet is bad. */ #define REJCIADDR(opt, neg, old, val1, val2) \ if (go->neg && \ len >= (cilen = old? CILEN_ADDRS: CILEN_ADDR) && \ p[1] == cilen && \ p[0] == opt) { \ u_int32_t l; \ len -= cilen; \ INCPTR(2, p); \ GETLONG(l, p); \ cilong = htonl(l); \ /* Check rejected value. */ \ if (cilong != val1) \ goto bad; \ if (old) { \ GETLONG(l, p); \ cilong = htonl(l); \ /* Check rejected value. */ \ if (cilong != val2) \ goto bad; \ } \ try.neg = 0; \ } #define REJCIVJ(opt, neg, val, old, maxslot, cflag) \ if (go->neg && \ p[1] == (old? CILEN_COMPRESS : CILEN_VJ) && \ len >= p[1] && \ p[0] == opt) { \ len -= p[1]; \ INCPTR(2, p); \ GETSHORT(cishort, p); \ /* Check rejected value. */ \ if (cishort != val) \ goto bad; \ if (!old) { \ GETCHAR(cimaxslotindex, p); \ if (cimaxslotindex != maxslot) \ goto bad; \ GETCHAR(ciflag, p); \ if (ciflag != cflag) \ goto bad; \ } \ try.neg = 0; \ } #define REJCIDNS(opt, neg, dnsaddr) \ if (go->neg && \ ((cilen = p[1]) == CILEN_ADDR) && \ len >= cilen && \ p[0] == opt) { \ u_int32_t l; \ len -= cilen; \ INCPTR(2, p); \ GETLONG(l, p); \ cilong = htonl(l); \ /* Check rejected value. */ \ if (cilong != dnsaddr) \ goto bad; \ try.neg = 0; \ } REJCIADDR((go->old_addrs? CI_ADDRS: CI_ADDR), neg_addr, go->old_addrs, go->ouraddr, go->hisaddr); REJCIVJ(CI_COMPRESSTYPE, neg_vj, go->vj_protocol, go->old_vj, go->maxslotindex, go->cflag); REJCIDNS(CI_MS_DNS1, req_dns1, go->dnsaddr[0]); REJCIDNS(CI_MS_DNS2, req_dns2, go->dnsaddr[1]); /* * If there are any remaining CIs, then this packet is bad. */ if (len != 0) goto bad; /* * Now we can update state. */ if (f->state != OPENED) *go = try; return 1; bad: IPCPDEBUG(("ipcp_rejci: received bad Reject!")); return 0; } /* * ipcp_reqci - Check the peer's requested CIs and send appropriate response. * Callback from fsm_rconfreq, Receive Configure Request * * Returns: CONFACK, CONFNAK or CONFREJ and input packet modified * appropriately. If reject_if_disagree is non-zero, doesn't return * CONFNAK; returns CONFREJ if it can't return CONFACK. */ static int ipcp_reqci(f, inp, len, reject_if_disagree) fsm *f; u_char *inp; /* Requested CIs */ int *len; /* Length of requested CIs */ int reject_if_disagree; { ipcp_options *wo = &ipcp_wantoptions[f->unit]; ipcp_options *ho = &ipcp_hisoptions[f->unit]; ipcp_options *ao = &ipcp_allowoptions[f->unit]; ipcp_options *go = &ipcp_gotoptions[f->unit]; u_char *cip, *next; /* Pointer to current and next CIs */ u_short cilen, citype; /* Parsed len, type */ u_short cishort; /* Parsed short value */ u_int32_t tl, ciaddr1, ciaddr2;/* Parsed address values */ int rc = CONFACK; /* Final packet return code */ int orc; /* Individual option return code */ u_char *p; /* Pointer to next char to parse */ u_char *ucp = inp; /* Pointer to current output char */ int l = *len; /* Length left */ u_char maxslotindex, cflag; int d; /* * Reset all his options. */ BZERO(ho, sizeof(*ho)); /* * Process all his options. */ next = inp; while (l) { orc = CONFACK; /* Assume success */ cip = p = next; /* Remember begining of CI */ if (l < 2 || /* Not enough data for CI header or */ p[1] < 2 || /* CI length too small or */ p[1] > l) { /* CI length too big? */ IPCPDEBUG(("ipcp_reqci: bad CI length!")); orc = CONFREJ; /* Reject bad CI */ cilen = l; /* Reject till end of packet */ l = 0; /* Don't loop again */ goto endswitch; } GETCHAR(citype, p); /* Parse CI type */ GETCHAR(cilen, p); /* Parse CI length */ l -= cilen; /* Adjust remaining length */ next += cilen; /* Step to next CI */ switch (citype) { /* Check CI type */ case CI_ADDRS: if (!ao->neg_addr || cilen != CILEN_ADDRS) { /* Check CI length */ orc = CONFREJ; /* Reject CI */ break; } /* * If he has no address, or if we both have his address but * disagree about it, then NAK it with our idea. * In particular, if we don't know his address, but he does, * then accept it. */ GETLONG(tl, p); /* Parse source address (his) */ ciaddr1 = htonl(tl); if (ciaddr1 != wo->hisaddr && (ciaddr1 == 0 || !wo->accept_remote)) { orc = CONFNAK; if (!reject_if_disagree) { DECPTR(sizeof(u_int32_t), p); tl = ntohl(wo->hisaddr); PUTLONG(tl, p); } } else if (ciaddr1 == 0 && wo->hisaddr == 0) { /* * If neither we nor he knows his address, reject the option. */ orc = CONFREJ; wo->req_addr = 0; /* don't NAK with 0.0.0.0 later */ break; } /* * If he doesn't know our address, or if we both have our address * but disagree about it, then NAK it with our idea. */ GETLONG(tl, p); /* Parse desination address (ours) */ ciaddr2 = htonl(tl); if (ciaddr2 != wo->ouraddr) { if (ciaddr2 == 0 || !wo->accept_local) { orc = CONFNAK; if (!reject_if_disagree) { DECPTR(sizeof(u_int32_t), p); tl = ntohl(wo->ouraddr); PUTLONG(tl, p); } } else { go->ouraddr = ciaddr2; /* accept peer's idea */ } } ho->neg_addr = 1; ho->old_addrs = 1; ho->hisaddr = ciaddr1; ho->ouraddr = ciaddr2; break; case CI_ADDR: if (!ao->neg_addr || cilen != CILEN_ADDR) { /* Check CI length */ orc = CONFREJ; /* Reject CI */ break; } /* * If he has no address, or if we both have his address but * disagree about it, then NAK it with our idea. * In particular, if we don't know his address, but he does, * then accept it. */ GETLONG(tl, p); /* Parse source address (his) */ ciaddr1 = htonl(tl); if (ciaddr1 != wo->hisaddr && (ciaddr1 == 0 || !wo->accept_remote)) { orc = CONFNAK; if (!reject_if_disagree) { DECPTR(sizeof(u_int32_t), p); tl = ntohl(wo->hisaddr); PUTLONG(tl, p); } } else if (ciaddr1 == 0 && wo->hisaddr == 0) { /* * Don't ACK an address of 0.0.0.0 - reject it instead. */ orc = CONFREJ; wo->req_addr = 0; /* don't NAK with 0.0.0.0 later */ break; } ho->neg_addr = 1; ho->hisaddr = ciaddr1; break; case CI_MS_DNS1: case CI_MS_DNS2: /* Microsoft primary or secondary DNS request */ d = citype == CI_MS_DNS2; /* If we do not have a DNS address then we cannot send it */ if (ao->dnsaddr[d] == 0 || cilen != CILEN_ADDR) { /* Check CI length */ orc = CONFREJ; /* Reject CI */ break; } GETLONG(tl, p); if (htonl(tl) != ao->dnsaddr[d]) { DECPTR(sizeof(u_int32_t), p); tl = ntohl(ao->dnsaddr[d]); PUTLONG(tl, p); orc = CONFNAK; } break; case CI_MS_WINS1: case CI_MS_WINS2: /* Microsoft primary or secondary WINS request */ d = citype == CI_MS_WINS2; /* If we do not have a DNS address then we cannot send it */ if (ao->winsaddr[d] == 0 || cilen != CILEN_ADDR) { /* Check CI length */ orc = CONFREJ; /* Reject CI */ break; } GETLONG(tl, p); if (htonl(tl) != ao->winsaddr[d]) { DECPTR(sizeof(u_int32_t), p); tl = ntohl(ao->winsaddr[d]); PUTLONG(tl, p); orc = CONFNAK; } break; case CI_COMPRESSTYPE: if (!ao->neg_vj || (cilen != CILEN_VJ && cilen != CILEN_COMPRESS)) { orc = CONFREJ; break; } GETSHORT(cishort, p); if (!(cishort == IPCP_VJ_COMP || (cishort == IPCP_VJ_COMP_OLD && cilen == CILEN_COMPRESS))) { orc = CONFREJ; break; } ho->neg_vj = 1; ho->vj_protocol = cishort; if (cilen == CILEN_VJ) { GETCHAR(maxslotindex, p); if (maxslotindex > ao->maxslotindex) { orc = CONFNAK; if (!reject_if_disagree){ DECPTR(1, p); PUTCHAR(ao->maxslotindex, p); } } GETCHAR(cflag, p); if (cflag && !ao->cflag) { orc = CONFNAK; if (!reject_if_disagree){ DECPTR(1, p); PUTCHAR(wo->cflag, p); } } ho->maxslotindex = maxslotindex; ho->cflag = cflag; } else { ho->old_vj = 1; ho->maxslotindex = MAX_STATES - 1; ho->cflag = 1; } break; default: orc = CONFREJ; break; } endswitch: if (orc == CONFACK && /* Good CI */ rc != CONFACK) /* but prior CI wasnt? */ continue; /* Don't send this one */ if (orc == CONFNAK) { /* Nak this CI? */ if (reject_if_disagree) /* Getting fed up with sending NAKs? */ orc = CONFREJ; /* Get tough if so */ else { if (rc == CONFREJ) /* Rejecting prior CI? */ continue; /* Don't send this one */ if (rc == CONFACK) { /* Ack'd all prior CIs? */ rc = CONFNAK; /* Not anymore... */ ucp = inp; /* Backup */ } } } if (orc == CONFREJ && /* Reject this CI */ rc != CONFREJ) { /* but no prior ones? */ rc = CONFREJ; ucp = inp; /* Backup */ } /* Need to move CI? */ if (ucp != cip) BCOPY(cip, ucp, cilen); /* Move it */ /* Update output pointer */ INCPTR(cilen, ucp); } /* * If we aren't rejecting this packet, and we want to negotiate * their address, and they didn't send their address, then we * send a NAK with a CI_ADDR option appended. We assume the * input buffer is long enough that we can append the extra * option safely. */ if (rc != CONFREJ && !ho->neg_addr && wo->req_addr && !reject_if_disagree) { if (rc == CONFACK) { rc = CONFNAK; ucp = inp; /* reset pointer */ wo->req_addr = 0; /* don't ask again */ } PUTCHAR(CI_ADDR, ucp); PUTCHAR(CILEN_ADDR, ucp); tl = ntohl(wo->hisaddr); PUTLONG(tl, ucp); } *len = ucp - inp; /* Compute output length */ IPCPDEBUG(("ipcp: returning Configure-%s", CODENAME(rc))); return (rc); /* Return final code */ } /* * ip_check_options - check that any IP-related options are OK, * and assign appropriate defaults. */ static void ip_check_options() { struct hostent *hp; u_int32_t local; ipcp_options *wo = &ipcp_wantoptions[0]; /* * Default our local IP address based on our hostname. * If local IP address already given, don't bother. */ if (wo->ouraddr == 0) { /* * Look up our hostname (possibly with domain name appended) * and take the first IP address as our local IP address. * If there isn't an IP address for our hostname, too bad. */ wo->accept_local = 1; /* don't insist on this default value */ if ((hp = gethostbyname(hostname)) != NULL) { local = *(u_int32_t *)hp->h_addr; if (local != 0 && !bad_ip_adrs(local)) wo->ouraddr = local; } } } /* * ip_demand_conf - configure the interface as though * IPCP were up, for use with dial-on-demand. */ static int ip_demand_conf(u) int u; { ipcp_options *wo = &ipcp_wantoptions[u]; if (wo->hisaddr == 0) { /* make up an arbitrary address for the peer */ wo->hisaddr = htonl(0x0a707070 + pppifunit); wo->accept_remote = 1; } if (wo->ouraddr == 0) { /* make up an arbitrary address for us */ wo->ouraddr = htonl(0x0a404040 + pppifunit); wo->accept_local = 1; disable_defaultip = 1; /* don't tell the peer this address */ } if (!sifaddr(u, wo->ouraddr, wo->hisaddr, GetMask(wo->ouraddr))) return 0; if (!sifup(u)) return 0; if (!sifnpmode(u, PPP_IP, NPMODE_QUEUE)) return 0; if (wo->default_route) if (sifdefaultroute(u, wo->ouraddr, wo->hisaddr)) default_route_set[u] = 1; if (wo->proxy_arp) if (sifproxyarp(u, wo->hisaddr)) proxy_arp_set[u] = 1; notice("local IP address %I", wo->ouraddr); notice("remote IP address %I", wo->hisaddr); return 1; } /* * ipcp_up - IPCP has come UP. * * Configure the IP network interface appropriately and bring it up. */ static void ipcp_up(f) fsm *f; { u_int32_t mask; ipcp_options *ho = &ipcp_hisoptions[f->unit]; ipcp_options *go = &ipcp_gotoptions[f->unit]; ipcp_options *wo = &ipcp_wantoptions[f->unit]; IPCPDEBUG(("ipcp: up")); /* * We must have a non-zero IP address for both ends of the link. */ if (!ho->neg_addr) ho->hisaddr = wo->hisaddr; if (ho->hisaddr == 0) { error("Could not determine remote IP address"); ipcp_close(f->unit, "Could not determine remote IP address"); return; } if (go->ouraddr == 0) { error("Could not determine local IP address"); ipcp_close(f->unit, "Could not determine local IP address"); return; } if (usepeerdns && (go->dnsaddr[0] || go->dnsaddr[1])) { create_resolv(go->dnsaddr[0], go->dnsaddr[1]); } /* * Check that the peer is allowed to use the IP address it wants. */ if (!auth_ip_addr(f->unit, ho->hisaddr)) { error("Peer is not authorized to use remote address %I", ho->hisaddr); ipcp_close(f->unit, "Unauthorized remote IP address"); return; } /* set tcp compression */ sifvjcomp(f->unit, ho->neg_vj, ho->cflag, ho->maxslotindex); /* * If we are doing dial-on-demand, the interface is already * configured, so we put out any saved-up packets, then set the * interface to pass IP packets. */ if (demand) { if (go->ouraddr != wo->ouraddr || ho->hisaddr != wo->hisaddr) { ipcp_clear_addrs(f->unit, wo->ouraddr, wo->hisaddr); if (go->ouraddr != wo->ouraddr) { warn("Local IP address changed to %I", go->ouraddr); wo->ouraddr = go->ouraddr; } if (ho->hisaddr != wo->hisaddr) { warn("Remote IP address changed to %I", ho->hisaddr); wo->hisaddr = ho->hisaddr; } /* Set the interface to the new addresses */ mask = GetMask(go->ouraddr); if (!sifaddr(f->unit, go->ouraddr, ho->hisaddr, mask)) { if (debug) warn("Interface configuration failed"); ipcp_close(f->unit, "Interface configuration failed"); return; } /* assign a default route through the interface if required */ if (ipcp_wantoptions[f->unit].default_route) if (sifdefaultroute(f->unit, go->ouraddr, ho->hisaddr)) default_route_set[f->unit] = 1; /* Make a proxy ARP entry if requested. */ if (ipcp_wantoptions[f->unit].proxy_arp) if (sifproxyarp(f->unit, ho->hisaddr)) proxy_arp_set[f->unit] = 1; } demand_rexmit(PPP_IP); sifnpmode(f->unit, PPP_IP, NPMODE_PASS); } else { /* * Set IP addresses and (if specified) netmask. */ mask = GetMask(go->ouraddr); #if !(defined(SVR4) && (defined(SNI) || defined(__USLC__))) if (!sifaddr(f->unit, go->ouraddr, ho->hisaddr, mask)) { if (debug) warn("Interface configuration failed"); ipcp_close(f->unit, "Interface configuration failed"); return; } #endif /* bring the interface up for IP */ if (!sifup(f->unit)) { if (debug) warn("Interface failed to come up"); ipcp_close(f->unit, "Interface configuration failed"); return; } #if (defined(SVR4) && (defined(SNI) || defined(__USLC__))) if (!sifaddr(f->unit, go->ouraddr, ho->hisaddr, mask)) { if (debug) warn("Interface configuration failed"); ipcp_close(f->unit, "Interface configuration failed"); return; } #endif sifnpmode(f->unit, PPP_IP, NPMODE_PASS); /* assign a default route through the interface if required */ if (ipcp_wantoptions[f->unit].default_route) if (sifdefaultroute(f->unit, go->ouraddr, ho->hisaddr)) default_route_set[f->unit] = 1; /* Make a proxy ARP entry if requested. */ if (ipcp_wantoptions[f->unit].proxy_arp) if (sifproxyarp(f->unit, ho->hisaddr)) proxy_arp_set[f->unit] = 1; ipcp_wantoptions[0].ouraddr = go->ouraddr; notice("local IP address %I", go->ouraddr); notice("remote IP address %I", ho->hisaddr); if (go->dnsaddr[0]) notice("primary DNS address %I", go->dnsaddr[0]); if (go->dnsaddr[1]) notice("secondary DNS address %I", go->dnsaddr[1]); } np_up(f->unit, PPP_IP); ipcp_is_up = 1; if (ip_up_hook) ip_up_hook(); } /* * ipcp_down - IPCP has gone DOWN. * * Take the IP network interface down, clear its addresses * and delete routes through it. */ static void ipcp_down(f) fsm *f; { IPCPDEBUG(("ipcp: down")); /* XXX a bit IPv4-centric here, we only need to get the stats * before the interface is marked down. */ update_link_stats(f->unit); if (ip_down_hook) ip_down_hook(); if (ipcp_is_up) { ipcp_is_up = 0; np_down(f->unit, PPP_IP); } sifvjcomp(f->unit, 0, 0, 0); /* * If we are doing dial-on-demand, set the interface * to queue up outgoing packets (for now). */ if (demand) { sifnpmode(f->unit, PPP_IP, NPMODE_QUEUE); } else { sifnpmode(f->unit, PPP_IP, NPMODE_DROP); sifdown(f->unit); ipcp_clear_addrs(f->unit, ipcp_gotoptions[f->unit].ouraddr, ipcp_hisoptions[f->unit].hisaddr); } } /* * ipcp_clear_addrs() - clear the interface addresses, routes, * proxy arp entries, etc. */ static void ipcp_clear_addrs(unit, ouraddr, hisaddr) int unit; u_int32_t ouraddr; /* local address */ u_int32_t hisaddr; /* remote address */ { if (proxy_arp_set[unit]) { cifproxyarp(unit, hisaddr); proxy_arp_set[unit] = 0; } if (default_route_set[unit]) { cifdefaultroute(unit, ouraddr, hisaddr); default_route_set[unit] = 0; } cifaddr(unit, ouraddr, hisaddr); } /* * ipcp_finished - possibly shut down the lower layers. */ static void ipcp_finished(f) fsm *f; { np_finished(f->unit, PPP_IP); } /* * create_resolv - create the replacement resolv.conf file */ static void create_resolv(peerdns1, peerdns2) u_int32_t peerdns1, peerdns2; { extern int rtems_bsdnet_nameserver_count; extern struct in_addr rtems_bsdnet_nameserver[]; /* initialize values */ rtems_bsdnet_nameserver_count = (int)0; /* check to see if primary was specified */ if ( peerdns1 ) { rtems_bsdnet_nameserver[rtems_bsdnet_nameserver_count].s_addr = peerdns1; rtems_bsdnet_nameserver_count++; } /* check to see if secondary was specified */ if ( peerdns2 ) { rtems_bsdnet_nameserver[rtems_bsdnet_nameserver_count].s_addr = peerdns2; rtems_bsdnet_nameserver_count++; } /* initialize resolver */ __res_init(); } /* * ipcp_printpkt - print the contents of an IPCP packet. */ static char *ipcp_codenames[] = { "ConfReq", "ConfAck", "ConfNak", "ConfRej", "TermReq", "TermAck", "CodeRej" }; static int ipcp_printpkt(p, plen, printer, arg) u_char *p; int plen; void (*printer) __P((void *, char *, ...)); void *arg; { int code, id, len, olen; u_char *pstart, *optend; u_short cishort; u_int32_t cilong; if (plen < HEADERLEN) return 0; pstart = p; GETCHAR(code, p); GETCHAR(id, p); GETSHORT(len, p); if (len < HEADERLEN || len > plen) return 0; if (code >= 1 && code <= sizeof(ipcp_codenames) / sizeof(char *)) printer(arg, " %s", ipcp_codenames[code-1]); else printer(arg, " code=0x%x", code); printer(arg, " id=0x%x", id); len -= HEADERLEN; switch (code) { case CONFREQ: case CONFACK: case CONFNAK: case CONFREJ: /* print option list */ while (len >= 2) { GETCHAR(code, p); GETCHAR(olen, p); p -= 2; if (olen < 2 || olen > len) { break; } printer(arg, " <"); len -= olen; optend = p + olen; switch (code) { case CI_ADDRS: if (olen == CILEN_ADDRS) { p += 2; GETLONG(cilong, p); printer(arg, "addrs %I", htonl(cilong)); GETLONG(cilong, p); printer(arg, " %I", htonl(cilong)); } break; case CI_COMPRESSTYPE: if (olen >= CILEN_COMPRESS) { p += 2; GETSHORT(cishort, p); printer(arg, "compress "); switch (cishort) { case IPCP_VJ_COMP: printer(arg, "VJ"); break; case IPCP_VJ_COMP_OLD: printer(arg, "old-VJ"); break; default: printer(arg, "0x%x", cishort); } } break; case CI_ADDR: if (olen == CILEN_ADDR) { p += 2; GETLONG(cilong, p); printer(arg, "addr %I", htonl(cilong)); } break; case CI_MS_DNS1: case CI_MS_DNS2: p += 2; GETLONG(cilong, p); printer(arg, "ms-dns%d %I", code - CI_MS_DNS1 + 1, htonl(cilong)); break; case CI_MS_WINS1: case CI_MS_WINS2: p += 2; GETLONG(cilong, p); printer(arg, "ms-wins %I", htonl(cilong)); break; } while (p < optend) { GETCHAR(code, p); printer(arg, " %.2x", code); } printer(arg, ">"); } break; case TERMACK: case TERMREQ: if (len > 0 && *p >= ' ' && *p < 0x7f) { printer(arg, " "); print_string(p, len, printer, arg); p += len; len = 0; } break; } /* print the rest of the bytes in the packet */ for (; len > 0; --len) { GETCHAR(code, p); printer(arg, " %.2x", code); } return p - pstart; } /* * ip_active_pkt - see if this IP packet is worth bringing the link up for. * We don't bring the link up for IP fragments or for TCP FIN packets * with no data. */ #define IP_HDRLEN 20 /* bytes */ #define IP_OFFMASK 0x1fff #define IPPROTO_TCP 6 #define TCP_HDRLEN 20 #define TH_FIN 0x01 /* * We use these macros because the IP header may be at an odd address, * and some compilers might use word loads to get th_off or ip_hl. */ #define net_short(x) (((x)[0] << 8) + (x)[1]) #define get_iphl(x) (((unsigned char *)(x))[0] & 0xF) #define get_ipoff(x) net_short((unsigned char *)(x) + 6) #define get_ipproto(x) (((unsigned char *)(x))[9]) #define get_tcpoff(x) (((unsigned char *)(x))[12] >> 4) #define get_tcpflags(x) (((unsigned char *)(x))[13]) static int ip_active_pkt(pkt, len) u_char *pkt; int len; { u_char *tcp; int hlen; len -= PPP_HDRLEN; pkt += PPP_HDRLEN; if (len < IP_HDRLEN) return 0; if ((get_ipoff(pkt) & IP_OFFMASK) != 0) return 0; if (get_ipproto(pkt) != IPPROTO_TCP) return 1; hlen = get_iphl(pkt) * 4; if (len < hlen + TCP_HDRLEN) return 0; tcp = pkt + hlen; if ((get_tcpflags(tcp) & TH_FIN) != 0 && len == hlen + get_tcpoff(tcp) * 4) return 0; return 1; }