diff options
Diffstat (limited to 'freebsd/sys/netinet/ipfw/ip_fw2.c')
| -rw-r--r-- | freebsd/sys/netinet/ipfw/ip_fw2.c | 2495 |
1 files changed, 2495 insertions, 0 deletions
diff --git a/freebsd/sys/netinet/ipfw/ip_fw2.c b/freebsd/sys/netinet/ipfw/ip_fw2.c new file mode 100644 index 00000000..682cced1 --- /dev/null +++ b/freebsd/sys/netinet/ipfw/ip_fw2.c @@ -0,0 +1,2495 @@ +#include <freebsd/machine/rtems-bsd-config.h> + +/*- + * Copyright (c) 2002-2009 Luigi Rizzo, Universita` di Pisa + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + */ + +#include <freebsd/sys/cdefs.h> +__FBSDID("$FreeBSD$"); + +/* + * The FreeBSD IP packet firewall, main file + */ + +#if !defined(KLD_MODULE) +#include <freebsd/local/opt_ipfw.h> +#include <freebsd/local/opt_ipdivert.h> +#include <freebsd/local/opt_ipdn.h> +#include <freebsd/local/opt_inet.h> +#ifndef INET +#error IPFIREWALL requires INET. +#endif /* INET */ +#endif +#include <freebsd/local/opt_inet6.h> +#include <freebsd/local/opt_ipsec.h> + +#include <freebsd/sys/param.h> +#include <freebsd/sys/systm.h> +#include <freebsd/sys/condvar.h> +#include <freebsd/sys/eventhandler.h> +#include <freebsd/sys/malloc.h> +#include <freebsd/sys/mbuf.h> +#include <freebsd/sys/kernel.h> +#include <freebsd/sys/lock.h> +#include <freebsd/sys/jail.h> +#include <freebsd/sys/module.h> +#include <freebsd/sys/priv.h> +#include <freebsd/sys/proc.h> +#include <freebsd/sys/rwlock.h> +#include <freebsd/sys/socket.h> +#include <freebsd/sys/socketvar.h> +#include <freebsd/sys/sysctl.h> +#include <freebsd/sys/syslog.h> +#include <freebsd/sys/ucred.h> +#include <freebsd/net/ethernet.h> /* for ETHERTYPE_IP */ +#include <freebsd/net/if.h> +#include <freebsd/net/route.h> +#include <freebsd/net/pf_mtag.h> +#include <freebsd/net/vnet.h> + +#include <freebsd/netinet/in.h> +#include <freebsd/netinet/in_var.h> +#include <freebsd/netinet/in_pcb.h> +#include <freebsd/netinet/ip.h> +#include <freebsd/netinet/ip_var.h> +#include <freebsd/netinet/ip_icmp.h> +#include <freebsd/netinet/ip_fw.h> +#include <freebsd/netinet/ipfw/ip_fw_private.h> +#include <freebsd/netinet/ip_carp.h> +#include <freebsd/netinet/pim.h> +#include <freebsd/netinet/tcp_var.h> +#include <freebsd/netinet/udp.h> +#include <freebsd/netinet/udp_var.h> +#include <freebsd/netinet/sctp.h> + +#include <freebsd/netinet/ip6.h> +#include <freebsd/netinet/icmp6.h> +#ifdef INET6 +#include <freebsd/netinet6/scope6_var.h> +#include <freebsd/netinet6/ip6_var.h> +#endif + +#include <freebsd/machine/in_cksum.h> /* XXX for in_cksum */ + +#ifdef MAC +#include <freebsd/security/mac/mac_framework.h> +#endif + +/* + * static variables followed by global ones. + * All ipfw global variables are here. + */ + +/* ipfw_vnet_ready controls when we are open for business */ +static VNET_DEFINE(int, ipfw_vnet_ready) = 0; +#define V_ipfw_vnet_ready VNET(ipfw_vnet_ready) + +static VNET_DEFINE(int, fw_deny_unknown_exthdrs); +#define V_fw_deny_unknown_exthdrs VNET(fw_deny_unknown_exthdrs) + +#ifdef IPFIREWALL_DEFAULT_TO_ACCEPT +static int default_to_accept = 1; +#else +static int default_to_accept; +#endif + +VNET_DEFINE(int, autoinc_step); + +/* + * Each rule belongs to one of 32 different sets (0..31). + * The variable set_disable contains one bit per set. + * If the bit is set, all rules in the corresponding set + * are disabled. Set RESVD_SET(31) is reserved for the default rule + * and rules that are not deleted by the flush command, + * and CANNOT be disabled. + * Rules in set RESVD_SET can only be deleted individually. + */ +VNET_DEFINE(u_int32_t, set_disable); +#define V_set_disable VNET(set_disable) + +VNET_DEFINE(int, fw_verbose); +/* counter for ipfw_log(NULL...) */ +VNET_DEFINE(u_int64_t, norule_counter); +VNET_DEFINE(int, verbose_limit); + +/* layer3_chain contains the list of rules for layer 3 */ +VNET_DEFINE(struct ip_fw_chain, layer3_chain); + +ipfw_nat_t *ipfw_nat_ptr = NULL; +struct cfg_nat *(*lookup_nat_ptr)(struct nat_list *, int); +ipfw_nat_cfg_t *ipfw_nat_cfg_ptr; +ipfw_nat_cfg_t *ipfw_nat_del_ptr; +ipfw_nat_cfg_t *ipfw_nat_get_cfg_ptr; +ipfw_nat_cfg_t *ipfw_nat_get_log_ptr; + +#ifdef SYSCTL_NODE +uint32_t dummy_def = IPFW_DEFAULT_RULE; +uint32_t dummy_tables_max = IPFW_TABLES_MAX; + +SYSBEGIN(f3) + +SYSCTL_NODE(_net_inet_ip, OID_AUTO, fw, CTLFLAG_RW, 0, "Firewall"); +SYSCTL_VNET_INT(_net_inet_ip_fw, OID_AUTO, one_pass, + CTLFLAG_RW | CTLFLAG_SECURE3, &VNET_NAME(fw_one_pass), 0, + "Only do a single pass through ipfw when using dummynet(4)"); +SYSCTL_VNET_INT(_net_inet_ip_fw, OID_AUTO, autoinc_step, + CTLFLAG_RW, &VNET_NAME(autoinc_step), 0, + "Rule number auto-increment step"); +SYSCTL_VNET_INT(_net_inet_ip_fw, OID_AUTO, verbose, + CTLFLAG_RW | CTLFLAG_SECURE3, &VNET_NAME(fw_verbose), 0, + "Log matches to ipfw rules"); +SYSCTL_VNET_INT(_net_inet_ip_fw, OID_AUTO, verbose_limit, + CTLFLAG_RW, &VNET_NAME(verbose_limit), 0, + "Set upper limit of matches of ipfw rules logged"); +SYSCTL_UINT(_net_inet_ip_fw, OID_AUTO, default_rule, CTLFLAG_RD, + &dummy_def, 0, + "The default/max possible rule number."); +SYSCTL_UINT(_net_inet_ip_fw, OID_AUTO, tables_max, CTLFLAG_RD, + &dummy_tables_max, 0, + "The maximum number of tables."); +SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, default_to_accept, CTLFLAG_RDTUN, + &default_to_accept, 0, + "Make the default rule accept all packets."); +TUNABLE_INT("net.inet.ip.fw.default_to_accept", &default_to_accept); +SYSCTL_VNET_INT(_net_inet_ip_fw, OID_AUTO, static_count, + CTLFLAG_RD, &VNET_NAME(layer3_chain.n_rules), 0, + "Number of static rules"); + +#ifdef INET6 +SYSCTL_DECL(_net_inet6_ip6); +SYSCTL_NODE(_net_inet6_ip6, OID_AUTO, fw, CTLFLAG_RW, 0, "Firewall"); +SYSCTL_VNET_INT(_net_inet6_ip6_fw, OID_AUTO, deny_unknown_exthdrs, + CTLFLAG_RW | CTLFLAG_SECURE, &VNET_NAME(fw_deny_unknown_exthdrs), 0, + "Deny packets with unknown IPv6 Extension Headers"); +#endif /* INET6 */ + +SYSEND + +#endif /* SYSCTL_NODE */ + + +/* + * Some macros used in the various matching options. + * L3HDR maps an ipv4 pointer into a layer3 header pointer of type T + * Other macros just cast void * into the appropriate type + */ +#define L3HDR(T, ip) ((T *)((u_int32_t *)(ip) + (ip)->ip_hl)) +#define TCP(p) ((struct tcphdr *)(p)) +#define SCTP(p) ((struct sctphdr *)(p)) +#define UDP(p) ((struct udphdr *)(p)) +#define ICMP(p) ((struct icmphdr *)(p)) +#define ICMP6(p) ((struct icmp6_hdr *)(p)) + +static __inline int +icmptype_match(struct icmphdr *icmp, ipfw_insn_u32 *cmd) +{ + int type = icmp->icmp_type; + + return (type <= ICMP_MAXTYPE && (cmd->d[0] & (1<<type)) ); +} + +#define TT ( (1 << ICMP_ECHO) | (1 << ICMP_ROUTERSOLICIT) | \ + (1 << ICMP_TSTAMP) | (1 << ICMP_IREQ) | (1 << ICMP_MASKREQ) ) + +static int +is_icmp_query(struct icmphdr *icmp) +{ + int type = icmp->icmp_type; + + return (type <= ICMP_MAXTYPE && (TT & (1<<type)) ); +} +#undef TT + +/* + * The following checks use two arrays of 8 or 16 bits to store the + * bits that we want set or clear, respectively. They are in the + * low and high half of cmd->arg1 or cmd->d[0]. + * + * We scan options and store the bits we find set. We succeed if + * + * (want_set & ~bits) == 0 && (want_clear & ~bits) == want_clear + * + * The code is sometimes optimized not to store additional variables. + */ + +static int +flags_match(ipfw_insn *cmd, u_int8_t bits) +{ + u_char want_clear; + bits = ~bits; + + if ( ((cmd->arg1 & 0xff) & bits) != 0) + return 0; /* some bits we want set were clear */ + want_clear = (cmd->arg1 >> 8) & 0xff; + if ( (want_clear & bits) != want_clear) + return 0; /* some bits we want clear were set */ + return 1; +} + +static int +ipopts_match(struct ip *ip, ipfw_insn *cmd) +{ + int optlen, bits = 0; + u_char *cp = (u_char *)(ip + 1); + int x = (ip->ip_hl << 2) - sizeof (struct ip); + + for (; x > 0; x -= optlen, cp += optlen) { + int opt = cp[IPOPT_OPTVAL]; + + if (opt == IPOPT_EOL) + break; + if (opt == IPOPT_NOP) + optlen = 1; + else { + optlen = cp[IPOPT_OLEN]; + if (optlen <= 0 || optlen > x) + return 0; /* invalid or truncated */ + } + switch (opt) { + + default: + break; + + case IPOPT_LSRR: + bits |= IP_FW_IPOPT_LSRR; + break; + + case IPOPT_SSRR: + bits |= IP_FW_IPOPT_SSRR; + break; + + case IPOPT_RR: + bits |= IP_FW_IPOPT_RR; + break; + + case IPOPT_TS: + bits |= IP_FW_IPOPT_TS; + break; + } + } + return (flags_match(cmd, bits)); +} + +static int +tcpopts_match(struct tcphdr *tcp, ipfw_insn *cmd) +{ + int optlen, bits = 0; + u_char *cp = (u_char *)(tcp + 1); + int x = (tcp->th_off << 2) - sizeof(struct tcphdr); + + for (; x > 0; x -= optlen, cp += optlen) { + int opt = cp[0]; + if (opt == TCPOPT_EOL) + break; + if (opt == TCPOPT_NOP) + optlen = 1; + else { + optlen = cp[1]; + if (optlen <= 0) + break; + } + + switch (opt) { + + default: + break; + + case TCPOPT_MAXSEG: + bits |= IP_FW_TCPOPT_MSS; + break; + + case TCPOPT_WINDOW: + bits |= IP_FW_TCPOPT_WINDOW; + break; + + case TCPOPT_SACK_PERMITTED: + case TCPOPT_SACK: + bits |= IP_FW_TCPOPT_SACK; + break; + + case TCPOPT_TIMESTAMP: + bits |= IP_FW_TCPOPT_TS; + break; + + } + } + return (flags_match(cmd, bits)); +} + +static int +iface_match(struct ifnet *ifp, ipfw_insn_if *cmd) +{ + if (ifp == NULL) /* no iface with this packet, match fails */ + return 0; + /* Check by name or by IP address */ + if (cmd->name[0] != '\0') { /* match by name */ + /* Check name */ + if (cmd->p.glob) { + if (fnmatch(cmd->name, ifp->if_xname, 0) == 0) + return(1); + } else { + if (strncmp(ifp->if_xname, cmd->name, IFNAMSIZ) == 0) + return(1); + } + } else { +#ifdef __FreeBSD__ /* and OSX too ? */ + struct ifaddr *ia; + + if_addr_rlock(ifp); + TAILQ_FOREACH(ia, &ifp->if_addrhead, ifa_link) { + if (ia->ifa_addr->sa_family != AF_INET) + continue; + if (cmd->p.ip.s_addr == ((struct sockaddr_in *) + (ia->ifa_addr))->sin_addr.s_addr) { + if_addr_runlock(ifp); + return(1); /* match */ + } + } + if_addr_runlock(ifp); +#endif /* __FreeBSD__ */ + } + return(0); /* no match, fail ... */ +} + +/* + * The verify_path function checks if a route to the src exists and + * if it is reachable via ifp (when provided). + * + * The 'verrevpath' option checks that the interface that an IP packet + * arrives on is the same interface that traffic destined for the + * packet's source address would be routed out of. + * The 'versrcreach' option just checks that the source address is + * reachable via any route (except default) in the routing table. + * These two are a measure to block forged packets. This is also + * commonly known as "anti-spoofing" or Unicast Reverse Path + * Forwarding (Unicast RFP) in Cisco-ese. The name of the knobs + * is purposely reminiscent of the Cisco IOS command, + * + * ip verify unicast reverse-path + * ip verify unicast source reachable-via any + * + * which implements the same functionality. But note that the syntax + * is misleading, and the check may be performed on all IP packets + * whether unicast, multicast, or broadcast. + */ +static int +verify_path(struct in_addr src, struct ifnet *ifp, u_int fib) +{ +#ifndef __FreeBSD__ + return 0; +#else + struct route ro; + struct sockaddr_in *dst; + + bzero(&ro, sizeof(ro)); + + dst = (struct sockaddr_in *)&(ro.ro_dst); + dst->sin_family = AF_INET; + dst->sin_len = sizeof(*dst); + dst->sin_addr = src; + in_rtalloc_ign(&ro, 0, fib); + + if (ro.ro_rt == NULL) + return 0; + + /* + * If ifp is provided, check for equality with rtentry. + * We should use rt->rt_ifa->ifa_ifp, instead of rt->rt_ifp, + * in order to pass packets injected back by if_simloop(): + * if useloopback == 1 routing entry (via lo0) for our own address + * may exist, so we need to handle routing assymetry. + */ + if (ifp != NULL && ro.ro_rt->rt_ifa->ifa_ifp != ifp) { + RTFREE(ro.ro_rt); + return 0; + } + + /* if no ifp provided, check if rtentry is not default route */ + if (ifp == NULL && + satosin(rt_key(ro.ro_rt))->sin_addr.s_addr == INADDR_ANY) { + RTFREE(ro.ro_rt); + return 0; + } + + /* or if this is a blackhole/reject route */ + if (ifp == NULL && ro.ro_rt->rt_flags & (RTF_REJECT|RTF_BLACKHOLE)) { + RTFREE(ro.ro_rt); + return 0; + } + + /* found valid route */ + RTFREE(ro.ro_rt); + return 1; +#endif /* __FreeBSD__ */ +} + +#ifdef INET6 +/* + * ipv6 specific rules here... + */ +static __inline int +icmp6type_match (int type, ipfw_insn_u32 *cmd) +{ + return (type <= ICMP6_MAXTYPE && (cmd->d[type/32] & (1<<(type%32)) ) ); +} + +static int +flow6id_match( int curr_flow, ipfw_insn_u32 *cmd ) +{ + int i; + for (i=0; i <= cmd->o.arg1; ++i ) + if (curr_flow == cmd->d[i] ) + return 1; + return 0; +} + +/* support for IP6_*_ME opcodes */ +static int +search_ip6_addr_net (struct in6_addr * ip6_addr) +{ + struct ifnet *mdc; + struct ifaddr *mdc2; + struct in6_ifaddr *fdm; + struct in6_addr copia; + + TAILQ_FOREACH(mdc, &V_ifnet, if_link) { + if_addr_rlock(mdc); + TAILQ_FOREACH(mdc2, &mdc->if_addrhead, ifa_link) { + if (mdc2->ifa_addr->sa_family == AF_INET6) { + fdm = (struct in6_ifaddr *)mdc2; + copia = fdm->ia_addr.sin6_addr; + /* need for leaving scope_id in the sock_addr */ + in6_clearscope(&copia); + if (IN6_ARE_ADDR_EQUAL(ip6_addr, &copia)) { + if_addr_runlock(mdc); + return 1; + } + } + } + if_addr_runlock(mdc); + } + return 0; +} + +static int +verify_path6(struct in6_addr *src, struct ifnet *ifp) +{ + struct route_in6 ro; + struct sockaddr_in6 *dst; + + bzero(&ro, sizeof(ro)); + + dst = (struct sockaddr_in6 * )&(ro.ro_dst); + dst->sin6_family = AF_INET6; + dst->sin6_len = sizeof(*dst); + dst->sin6_addr = *src; + /* XXX MRT 0 for ipv6 at this time */ + rtalloc_ign((struct route *)&ro, 0); + + if (ro.ro_rt == NULL) + return 0; + + /* + * if ifp is provided, check for equality with rtentry + * We should use rt->rt_ifa->ifa_ifp, instead of rt->rt_ifp, + * to support the case of sending packets to an address of our own. + * (where the former interface is the first argument of if_simloop() + * (=ifp), the latter is lo0) + */ + if (ifp != NULL && ro.ro_rt->rt_ifa->ifa_ifp != ifp) { + RTFREE(ro.ro_rt); + return 0; + } + + /* if no ifp provided, check if rtentry is not default route */ + if (ifp == NULL && + IN6_IS_ADDR_UNSPECIFIED(&satosin6(rt_key(ro.ro_rt))->sin6_addr)) { + RTFREE(ro.ro_rt); + return 0; + } + + /* or if this is a blackhole/reject route */ + if (ifp == NULL && ro.ro_rt->rt_flags & (RTF_REJECT|RTF_BLACKHOLE)) { + RTFREE(ro.ro_rt); + return 0; + } + + /* found valid route */ + RTFREE(ro.ro_rt); + return 1; + +} + +static int +is_icmp6_query(int icmp6_type) +{ + if ((icmp6_type <= ICMP6_MAXTYPE) && + (icmp6_type == ICMP6_ECHO_REQUEST || + icmp6_type == ICMP6_MEMBERSHIP_QUERY || + icmp6_type == ICMP6_WRUREQUEST || + icmp6_type == ICMP6_FQDN_QUERY || + icmp6_type == ICMP6_NI_QUERY)) + return (1); + + return (0); +} + +static void +send_reject6(struct ip_fw_args *args, int code, u_int hlen, struct ip6_hdr *ip6) +{ + struct mbuf *m; + + m = args->m; + if (code == ICMP6_UNREACH_RST && args->f_id.proto == IPPROTO_TCP) { + struct tcphdr *tcp; + tcp = (struct tcphdr *)((char *)ip6 + hlen); + + if ((tcp->th_flags & TH_RST) == 0) { + struct mbuf *m0; + m0 = ipfw_send_pkt(args->m, &(args->f_id), + ntohl(tcp->th_seq), ntohl(tcp->th_ack), + tcp->th_flags | TH_RST); + if (m0 != NULL) + ip6_output(m0, NULL, NULL, 0, NULL, NULL, + NULL); + } + FREE_PKT(m); + } else if (code != ICMP6_UNREACH_RST) { /* Send an ICMPv6 unreach. */ +#if 0 + /* + * Unlike above, the mbufs need to line up with the ip6 hdr, + * as the contents are read. We need to m_adj() the + * needed amount. + * The mbuf will however be thrown away so we can adjust it. + * Remember we did an m_pullup on it already so we + * can make some assumptions about contiguousness. + */ + if (args->L3offset) + m_adj(m, args->L3offset); +#endif + icmp6_error(m, ICMP6_DST_UNREACH, code, 0); + } else + FREE_PKT(m); + + args->m = NULL; +} + +#endif /* INET6 */ + + +/* + * sends a reject message, consuming the mbuf passed as an argument. + */ +static void +send_reject(struct ip_fw_args *args, int code, int iplen, struct ip *ip) +{ + +#if 0 + /* XXX When ip is not guaranteed to be at mtod() we will + * need to account for this */ + * The mbuf will however be thrown away so we can adjust it. + * Remember we did an m_pullup on it already so we + * can make some assumptions about contiguousness. + */ + if (args->L3offset) + m_adj(m, args->L3offset); +#endif + if (code != ICMP_REJECT_RST) { /* Send an ICMP unreach */ + /* We need the IP header in host order for icmp_error(). */ + SET_HOST_IPLEN(ip); + icmp_error(args->m, ICMP_UNREACH, code, 0L, 0); + } else if (args->f_id.proto == IPPROTO_TCP) { + struct tcphdr *const tcp = + L3HDR(struct tcphdr, mtod(args->m, struct ip *)); + if ( (tcp->th_flags & TH_RST) == 0) { + struct mbuf *m; + m = ipfw_send_pkt(args->m, &(args->f_id), + ntohl(tcp->th_seq), ntohl(tcp->th_ack), + tcp->th_flags | TH_RST); + if (m != NULL) + ip_output(m, NULL, NULL, 0, NULL, NULL); + } + FREE_PKT(args->m); + } else + FREE_PKT(args->m); + args->m = NULL; +} + +/* + * Support for uid/gid/jail lookup. These tests are expensive + * (because we may need to look into the list of active sockets) + * so we cache the results. ugid_lookupp is 0 if we have not + * yet done a lookup, 1 if we succeeded, and -1 if we tried + * and failed. The function always returns the match value. + * We could actually spare the variable and use *uc, setting + * it to '(void *)check_uidgid if we have no info, NULL if + * we tried and failed, or any other value if successful. + */ +static int +check_uidgid(ipfw_insn_u32 *insn, int proto, struct ifnet *oif, + struct in_addr dst_ip, u_int16_t dst_port, struct in_addr src_ip, + u_int16_t src_port, int *ugid_lookupp, + struct ucred **uc, struct inpcb *inp) +{ +#ifndef __FreeBSD__ + return cred_check(insn, proto, oif, + dst_ip, dst_port, src_ip, src_port, + (struct bsd_ucred *)uc, ugid_lookupp, ((struct mbuf *)inp)->m_skb); +#else /* FreeBSD */ + struct inpcbinfo *pi; + int wildcard; + struct inpcb *pcb; + int match; + + /* + * Check to see if the UDP or TCP stack supplied us with + * the PCB. If so, rather then holding a lock and looking + * up the PCB, we can use the one that was supplied. + */ + if (inp && *ugid_lookupp == 0) { + INP_LOCK_ASSERT(inp); + if (inp->inp_socket != NULL) { + *uc = crhold(inp->inp_cred); + *ugid_lookupp = 1; + } else + *ugid_lookupp = -1; + } + /* + * If we have already been here and the packet has no + * PCB entry associated with it, then we can safely + * assume that this is a no match. + */ + if (*ugid_lookupp == -1) + return (0); + if (proto == IPPROTO_TCP) { + wildcard = 0; + pi = &V_tcbinfo; + } else if (proto == IPPROTO_UDP) { + wildcard = INPLOOKUP_WILDCARD; + pi = &V_udbinfo; + } else + return 0; + match = 0; + if (*ugid_lookupp == 0) { + INP_INFO_RLOCK(pi); + pcb = (oif) ? + in_pcblookup_hash(pi, + dst_ip, htons(dst_port), + src_ip, htons(src_port), + wildcard, oif) : + in_pcblookup_hash(pi, + src_ip, htons(src_port), + dst_ip, htons(dst_port), + wildcard, NULL); + if (pcb != NULL) { + *uc = crhold(pcb->inp_cred); + *ugid_lookupp = 1; + } + INP_INFO_RUNLOCK(pi); + if (*ugid_lookupp == 0) { + /* + * We tried and failed, set the variable to -1 + * so we will not try again on this packet. + */ + *ugid_lookupp = -1; + return (0); + } + } + if (insn->o.opcode == O_UID) + match = ((*uc)->cr_uid == (uid_t)insn->d[0]); + else if (insn->o.opcode == O_GID) + match = groupmember((gid_t)insn->d[0], *uc); + else if (insn->o.opcode == O_JAIL) + match = ((*uc)->cr_prison->pr_id == (int)insn->d[0]); + return match; +#endif /* __FreeBSD__ */ +} + +/* + * Helper function to set args with info on the rule after the matching + * one. slot is precise, whereas we guess rule_id as they are + * assigned sequentially. + */ +static inline void +set_match(struct ip_fw_args *args, int slot, + struct ip_fw_chain *chain) +{ + args->rule.chain_id = chain->id; + args->rule.slot = slot + 1; /* we use 0 as a marker */ + args->rule.rule_id = 1 + chain->map[slot]->id; + args->rule.rulenum = chain->map[slot]->rulenum; +} + +/* + * The main check routine for the firewall. + * + * All arguments are in args so we can modify them and return them + * back to the caller. + * + * Parameters: + * + * args->m (in/out) The packet; we set to NULL when/if we nuke it. + * Starts with the IP header. + * args->eh (in) Mac header if present, NULL for layer3 packet. + * args->L3offset Number of bytes bypassed if we came from L2. + * e.g. often sizeof(eh) ** NOTYET ** + * args->oif Outgoing interface, NULL if packet is incoming. + * The incoming interface is in the mbuf. (in) + * args->divert_rule (in/out) + * Skip up to the first rule past this rule number; + * upon return, non-zero port number for divert or tee. + * + * args->rule Pointer to the last matching rule (in/out) + * args->next_hop Socket we are forwarding to (out). + * args->f_id Addresses grabbed from the packet (out) + * args->rule.info a cookie depending on rule action + * + * Return value: + * + * IP_FW_PASS the packet must be accepted + * IP_FW_DENY the packet must be dropped + * IP_FW_DIVERT divert packet, port in m_tag + * IP_FW_TEE tee packet, port in m_tag + * IP_FW_DUMMYNET to dummynet, pipe in args->cookie + * IP_FW_NETGRAPH into netgraph, cookie args->cookie + * args->rule contains the matching rule, + * args->rule.info has additional information. + * + */ +int +ipfw_chk(struct ip_fw_args *args) +{ + + /* + * Local variables holding state while processing a packet: + * + * IMPORTANT NOTE: to speed up the processing of rules, there + * are some assumption on the values of the variables, which + * are documented here. Should you change them, please check + * the implementation of the various instructions to make sure + * that they still work. + * + * args->eh The MAC header. It is non-null for a layer2 + * packet, it is NULL for a layer-3 packet. + * **notyet** + * args->L3offset Offset in the packet to the L3 (IP or equiv.) header. + * + * m | args->m Pointer to the mbuf, as received from the caller. + * It may change if ipfw_chk() does an m_pullup, or if it + * consumes the packet because it calls send_reject(). + * XXX This has to change, so that ipfw_chk() never modifies + * or consumes the buffer. + * ip is the beginning of the ip(4 or 6) header. + * Calculated by adding the L3offset to the start of data. + * (Until we start using L3offset, the packet is + * supposed to start with the ip header). + */ + struct mbuf *m = args->m; + struct ip *ip = mtod(m, struct ip *); + + /* + * For rules which contain uid/gid or jail constraints, cache + * a copy of the users credentials after the pcb lookup has been + * executed. This will speed up the processing of rules with + * these types of constraints, as well as decrease contention + * on pcb related locks. + */ +#ifndef __FreeBSD__ + struct bsd_ucred ucred_cache; +#else + struct ucred *ucred_cache = NULL; +#endif + int ucred_lookup = 0; + + /* + * oif | args->oif If NULL, ipfw_chk has been called on the + * inbound path (ether_input, ip_input). + * If non-NULL, ipfw_chk has been called on the outbound path + * (ether_output, ip_output). + */ + struct ifnet *oif = args->oif; + + int f_pos = 0; /* index of current rule in the array */ + int retval = 0; + + /* + * hlen The length of the IP header. + */ + u_int hlen = 0; /* hlen >0 means we have an IP pkt */ + + /* + * offset The offset of a fragment. offset != 0 means that + * we have a fragment at this offset of an IPv4 packet. + * offset == 0 means that (if this is an IPv4 packet) + * this is the first or only fragment. + * For IPv6 offset == 0 means there is no Fragment Header. + * If offset != 0 for IPv6 always use correct mask to + * get the correct offset because we add IP6F_MORE_FRAG + * to be able to dectect the first fragment which would + * otherwise have offset = 0. + */ + u_short offset = 0; + + /* + * Local copies of addresses. They are only valid if we have + * an IP packet. + * + * proto The protocol. Set to 0 for non-ip packets, + * or to the protocol read from the packet otherwise. + * proto != 0 means that we have an IPv4 packet. + * + * src_port, dst_port port numbers, in HOST format. Only + * valid for TCP and UDP packets. + * + * src_ip, dst_ip ip addresses, in NETWORK format. + * Only valid for IPv4 packets. + */ + uint8_t proto; + uint16_t src_port = 0, dst_port = 0; /* NOTE: host format */ + struct in_addr src_ip, dst_ip; /* NOTE: network format */ + uint16_t iplen=0; + int pktlen; + uint16_t etype = 0; /* Host order stored ether type */ + + /* + * dyn_dir = MATCH_UNKNOWN when rules unchecked, + * MATCH_NONE when checked and not matched (q = NULL), + * MATCH_FORWARD or MATCH_REVERSE otherwise (q != NULL) + */ + int dyn_dir = MATCH_UNKNOWN; + ipfw_dyn_rule *q = NULL; + struct ip_fw_chain *chain = &V_layer3_chain; + + /* + * We store in ulp a pointer to the upper layer protocol header. + * In the ipv4 case this is easy to determine from the header, + * but for ipv6 we might have some additional headers in the middle. + * ulp is NULL if not found. + */ + void *ulp = NULL; /* upper layer protocol pointer. */ + + /* XXX ipv6 variables */ + int is_ipv6 = 0; + uint8_t icmp6_type = 0; + uint16_t ext_hd = 0; /* bits vector for extension header filtering */ + /* end of ipv6 variables */ + + int is_ipv4 = 0; + + int done = 0; /* flag to exit the outer loop */ + + if (m->m_flags & M_SKIP_FIREWALL || (! V_ipfw_vnet_ready)) + return (IP_FW_PASS); /* accept */ + + dst_ip.s_addr = 0; /* make sure it is initialized */ + src_ip.s_addr = 0; /* make sure it is initialized */ + pktlen = m->m_pkthdr.len; + args->f_id.fib = M_GETFIB(m); /* note mbuf not altered) */ + proto = args->f_id.proto = 0; /* mark f_id invalid */ + /* XXX 0 is a valid proto: IP/IPv6 Hop-by-Hop Option */ + +/* + * PULLUP_TO(len, p, T) makes sure that len + sizeof(T) is contiguous, + * then it sets p to point at the offset "len" in the mbuf. WARNING: the + * pointer might become stale after other pullups (but we never use it + * this way). + */ +#define PULLUP_TO(_len, p, T) \ +do { \ + int x = (_len) + sizeof(T); \ + if ((m)->m_len < x) { \ + args->m = m = m_pullup(m, x); \ + if (m == NULL) \ + goto pullup_failed; \ + } \ + p = (mtod(m, char *) + (_len)); \ +} while (0) + + /* + * if we have an ether header, + */ + if (args->eh) + etype = ntohs(args->eh->ether_type); + + /* Identify IP packets and fill up variables. */ + if (pktlen >= sizeof(struct ip6_hdr) && + (args->eh == NULL || etype == ETHERTYPE_IPV6) && ip->ip_v == 6) { + struct ip6_hdr *ip6 = (struct ip6_hdr *)ip; + is_ipv6 = 1; + args->f_id.addr_type = 6; + hlen = sizeof(struct ip6_hdr); + proto = ip6->ip6_nxt; + + /* Search extension headers to find upper layer protocols */ + while (ulp == NULL) { + switch (proto) { + case IPPROTO_ICMPV6: + PULLUP_TO(hlen, ulp, struct icmp6_hdr); + icmp6_type = ICMP6(ulp)->icmp6_type; + break; + + case IPPROTO_TCP: + PULLUP_TO(hlen, ulp, struct tcphdr); + dst_port = TCP(ulp)->th_dport; + src_port = TCP(ulp)->th_sport; + /* save flags for dynamic rules */ + args->f_id._flags = TCP(ulp)->th_flags; + break; + + case IPPROTO_SCTP: + PULLUP_TO(hlen, ulp, struct sctphdr); + src_port = SCTP(ulp)->src_port; + dst_port = SCTP(ulp)->dest_port; + break; + + case IPPROTO_UDP: + PULLUP_TO(hlen, ulp, struct udphdr); + dst_port = UDP(ulp)->uh_dport; + src_port = UDP(ulp)->uh_sport; + break; + + case IPPROTO_HOPOPTS: /* RFC 2460 */ + PULLUP_TO(hlen, ulp, struct ip6_hbh); + ext_hd |= EXT_HOPOPTS; + hlen += (((struct ip6_hbh *)ulp)->ip6h_len + 1) << 3; + proto = ((struct ip6_hbh *)ulp)->ip6h_nxt; + ulp = NULL; + break; + + case IPPROTO_ROUTING: /* RFC 2460 */ + PULLUP_TO(hlen, ulp, struct ip6_rthdr); + switch (((struct ip6_rthdr *)ulp)->ip6r_type) { + case 0: + ext_hd |= EXT_RTHDR0; + break; + case 2: + ext_hd |= EXT_RTHDR2; + break; + default: + printf("IPFW2: IPV6 - Unknown Routing " + "Header type(%d)\n", + ((struct ip6_rthdr *)ulp)->ip6r_type); + if (V_fw_deny_unknown_exthdrs) + return (IP_FW_DENY); + break; + } + ext_hd |= EXT_ROUTING; + hlen += (((struct ip6_rthdr *)ulp)->ip6r_len + 1) << 3; + proto = ((struct ip6_rthdr *)ulp)->ip6r_nxt; + ulp = NULL; + break; + + case IPPROTO_FRAGMENT: /* RFC 2460 */ + PULLUP_TO(hlen, ulp, struct ip6_frag); + ext_hd |= EXT_FRAGMENT; + hlen += sizeof (struct ip6_frag); + proto = ((struct ip6_frag *)ulp)->ip6f_nxt; + offset = ((struct ip6_frag *)ulp)->ip6f_offlg & + IP6F_OFF_MASK; + /* Add IP6F_MORE_FRAG for offset of first + * fragment to be != 0. */ + offset |= ((struct ip6_frag *)ulp)->ip6f_offlg & + IP6F_MORE_FRAG; + if (offset == 0) { + printf("IPFW2: IPV6 - Invalid Fragment " + "Header\n"); + if (V_fw_deny_unknown_exthdrs) + return (IP_FW_DENY); + break; + } + args->f_id.extra = + ntohl(((struct ip6_frag *)ulp)->ip6f_ident); + ulp = NULL; + break; + + case IPPROTO_DSTOPTS: /* RFC 2460 */ + PULLUP_TO(hlen, ulp, struct ip6_hbh); + ext_hd |= EXT_DSTOPTS; + hlen += (((struct ip6_hbh *)ulp)->ip6h_len + 1) << 3; + proto = ((struct ip6_hbh *)ulp)->ip6h_nxt; + ulp = NULL; + break; + + case IPPROTO_AH: /* RFC 2402 */ + PULLUP_TO(hlen, ulp, struct ip6_ext); + ext_hd |= EXT_AH; + hlen += (((struct ip6_ext *)ulp)->ip6e_len + 2) << 2; + proto = ((struct ip6_ext *)ulp)->ip6e_nxt; + ulp = NULL; + break; + + case IPPROTO_ESP: /* RFC 2406 */ + PULLUP_TO(hlen, ulp, uint32_t); /* SPI, Seq# */ + /* Anything past Seq# is variable length and + * data past this ext. header is encrypted. */ + ext_hd |= EXT_ESP; + break; + + case IPPROTO_NONE: /* RFC 2460 */ + /* + * Packet ends here, and IPv6 header has + * already been pulled up. If ip6e_len!=0 + * then octets must be ignored. + */ + ulp = ip; /* non-NULL to get out of loop. */ + break; + + case IPPROTO_OSPFIGP: + /* XXX OSPF header check? */ + PULLUP_TO(hlen, ulp, struct ip6_ext); + break; + + case IPPROTO_PIM: + /* XXX PIM header check? */ + PULLUP_TO(hlen, ulp, struct pim); + break; + + case IPPROTO_CARP: + PULLUP_TO(hlen, ulp, struct carp_header); + if (((struct carp_header *)ulp)->carp_version != + CARP_VERSION) + return (IP_FW_DENY); + if (((struct carp_header *)ulp)->carp_type != + CARP_ADVERTISEMENT) + return (IP_FW_DENY); + break; + + case IPPROTO_IPV6: /* RFC 2893 */ + PULLUP_TO(hlen, ulp, struct ip6_hdr); + break; + + case IPPROTO_IPV4: /* RFC 2893 */ + PULLUP_TO(hlen, ulp, struct ip); + break; + + default: + printf("IPFW2: IPV6 - Unknown Extension " + "Header(%d), ext_hd=%x\n", proto, ext_hd); + if (V_fw_deny_unknown_exthdrs) + return (IP_FW_DENY); + PULLUP_TO(hlen, ulp, struct ip6_ext); + break; + } /*switch */ + } + ip = mtod(m, struct ip *); + ip6 = (struct ip6_hdr *)ip; + args->f_id.src_ip6 = ip6->ip6_src; + args->f_id.dst_ip6 = ip6->ip6_dst; + args->f_id.src_ip = 0; + args->f_id.dst_ip = 0; + args->f_id.flow_id6 = ntohl(ip6->ip6_flow); + } else if (pktlen >= sizeof(struct ip) && + (args->eh == NULL || etype == ETHERTYPE_IP) && ip->ip_v == 4) { + is_ipv4 = 1; + hlen = ip->ip_hl << 2; + args->f_id.addr_type = 4; + + /* + * Collect parameters into local variables for faster matching. + */ + proto = ip->ip_p; + src_ip = ip->ip_src; + dst_ip = ip->ip_dst; + offset = ntohs(ip->ip_off) & IP_OFFMASK; + iplen = ntohs(ip->ip_len); + pktlen = iplen < pktlen ? iplen : pktlen; + + if (offset == 0) { + switch (proto) { + case IPPROTO_TCP: + PULLUP_TO(hlen, ulp, struct tcphdr); + dst_port = TCP(ulp)->th_dport; + src_port = TCP(ulp)->th_sport; + /* save flags for dynamic rules */ + args->f_id._flags = TCP(ulp)->th_flags; + break; + + case IPPROTO_UDP: + PULLUP_TO(hlen, ulp, struct udphdr); + dst_port = UDP(ulp)->uh_dport; + src_port = UDP(ulp)->uh_sport; + break; + + case IPPROTO_ICMP: + PULLUP_TO(hlen, ulp, struct icmphdr); + //args->f_id.flags = ICMP(ulp)->icmp_type; + break; + + default: + break; + } + } + + ip = mtod(m, struct ip *); + args->f_id.src_ip = ntohl(src_ip.s_addr); + args->f_id.dst_ip = ntohl(dst_ip.s_addr); + } +#undef PULLUP_TO + if (proto) { /* we may have port numbers, store them */ + args->f_id.proto = proto; + args->f_id.src_port = src_port = ntohs(src_port); + args->f_id.dst_port = dst_port = ntohs(dst_port); + } + + IPFW_RLOCK(chain); + if (! V_ipfw_vnet_ready) { /* shutting down, leave NOW. */ + IPFW_RUNLOCK(chain); + return (IP_FW_PASS); /* accept */ + } + if (args->rule.slot) { + /* + * Packet has already been tagged as a result of a previous + * match on rule args->rule aka args->rule_id (PIPE, QUEUE, + * REASS, NETGRAPH, DIVERT/TEE...) + * Validate the slot and continue from the next one + * if still present, otherwise do a lookup. + */ + f_pos = (args->rule.chain_id == chain->id) ? + args->rule.slot : + ipfw_find_rule(chain, args->rule.rulenum, + args->rule.rule_id); + } else { + f_pos = 0; + } + + /* + * Now scan the rules, and parse microinstructions for each rule. + * We have two nested loops and an inner switch. Sometimes we + * need to break out of one or both loops, or re-enter one of + * the loops with updated variables. Loop variables are: + * + * f_pos (outer loop) points to the current rule. + * On output it points to the matching rule. + * done (outer loop) is used as a flag to break the loop. + * l (inner loop) residual length of current rule. + * cmd points to the current microinstruction. + * + * We break the inner loop by setting l=0 and possibly + * cmdlen=0 if we don't want to advance cmd. + * We break the outer loop by setting done=1 + * We can restart the inner loop by setting l>0 and f_pos, f, cmd + * as needed. + */ + for (; f_pos < chain->n_rules; f_pos++) { + ipfw_insn *cmd; + uint32_t tablearg = 0; + int l, cmdlen, skip_or; /* skip rest of OR block */ + struct ip_fw *f; + + f = chain->map[f_pos]; + if (V_set_disable & (1 << f->set) ) + continue; + + skip_or = 0; + for (l = f->cmd_len, cmd = f->cmd ; l > 0 ; + l -= cmdlen, cmd += cmdlen) { + int match; + + /* + * check_body is a jump target used when we find a + * CHECK_STATE, and need to jump to the body of + * the target rule. + */ + +/* check_body: */ + cmdlen = F_LEN(cmd); + /* + * An OR block (insn_1 || .. || insn_n) has the + * F_OR bit set in all but the last instruction. + * The first match will set "skip_or", and cause + * the following instructions to be skipped until + * past the one with the F_OR bit clear. + */ + if (skip_or) { /* skip this instruction */ + if ((cmd->len & F_OR) == 0) + skip_or = 0; /* next one is good */ + continue; + } + match = 0; /* set to 1 if we succeed */ + + switch (cmd->opcode) { + /* + * The first set of opcodes compares the packet's + * fields with some pattern, setting 'match' if a + * match is found. At the end of the loop there is + * logic to deal with F_NOT and F_OR flags associated + * with the opcode. + */ + case O_NOP: + match = 1; + break; + + case O_FORWARD_MAC: + printf("ipfw: opcode %d unimplemented\n", + cmd->opcode); + break; + + case O_GID: + case O_UID: + case O_JAIL: + /* + * We only check offset == 0 && proto != 0, + * as this ensures that we have a + * packet with the ports info. + */ + if (offset!=0) + break; + if (is_ipv6) /* XXX to be fixed later */ + break; + if (proto == IPPROTO_TCP || + proto == IPPROTO_UDP) + match = check_uidgid( + (ipfw_insn_u32 *)cmd, + proto, oif, + dst_ip, dst_port, + src_ip, src_port, &ucred_lookup, +#ifdef __FreeBSD__ + &ucred_cache, args->inp); +#else + (void *)&ucred_cache, + (struct inpcb *)args->m); +#endif + break; + + case O_RECV: + match = iface_match(m->m_pkthdr.rcvif, + (ipfw_insn_if *)cmd); + break; + + case O_XMIT: + match = iface_match(oif, (ipfw_insn_if *)cmd); + break; + + case O_VIA: + match = iface_match(oif ? oif : + m->m_pkthdr.rcvif, (ipfw_insn_if *)cmd); + break; + + case O_MACADDR2: + if (args->eh != NULL) { /* have MAC header */ + u_int32_t *want = (u_int32_t *) + ((ipfw_insn_mac *)cmd)->addr; + u_int32_t *mask = (u_int32_t *) + ((ipfw_insn_mac *)cmd)->mask; + u_int32_t *hdr = (u_int32_t *)args->eh; + + match = + ( want[0] == (hdr[0] & mask[0]) && + want[1] == (hdr[1] & mask[1]) && + want[2] == (hdr[2] & mask[2]) ); + } + break; + + case O_MAC_TYPE: + if (args->eh != NULL) { + u_int16_t *p = + ((ipfw_insn_u16 *)cmd)->ports; + int i; + + for (i = cmdlen - 1; !match && i>0; + i--, p += 2) + match = (etype >= p[0] && + etype <= p[1]); + } + break; + + case O_FRAG: + match = (offset != 0); + break; + + case O_IN: /* "out" is "not in" */ + match = (oif == NULL); + break; + + case O_LAYER2: + match = (args->eh != NULL); + break; + + case O_DIVERTED: + { + /* For diverted packets, args->rule.info + * contains the divert port (in host format) + * reason and direction. + */ + uint32_t i = args->rule.info; + match = (i&IPFW_IS_MASK) == IPFW_IS_DIVERT && + cmd->arg1 & ((i & IPFW_INFO_IN) ? 1 : 2); + } + break; + + case O_PROTO: + /* + * We do not allow an arg of 0 so the + * check of "proto" only suffices. + */ + match = (proto == cmd->arg1); + break; + + case O_IP_SRC: + match = is_ipv4 && + (((ipfw_insn_ip *)cmd)->addr.s_addr == + src_ip.s_addr); + break; + + case O_IP_SRC_LOOKUP: + case O_IP_DST_LOOKUP: + if (is_ipv4) { + uint32_t key = + (cmd->opcode == O_IP_DST_LOOKUP) ? + dst_ip.s_addr : src_ip.s_addr; + uint32_t v = 0; + + if (cmdlen > F_INSN_SIZE(ipfw_insn_u32)) { + /* generic lookup. The key must be + * in 32bit big-endian format. + */ + v = ((ipfw_insn_u32 *)cmd)->d[1]; + if (v == 0) + key = dst_ip.s_addr; + else if (v == 1) + key = src_ip.s_addr; + else if (v == 6) /* dscp */ + key = (ip->ip_tos >> 2) & 0x3f; + else if (offset != 0) + break; + else if (proto != IPPROTO_TCP && + proto != IPPROTO_UDP) + break; + else if (v == 2) + key = htonl(dst_port); + else if (v == 3) + key = htonl(src_port); + else if (v == 4 || v == 5) { + check_uidgid( + (ipfw_insn_u32 *)cmd, + proto, oif, + dst_ip, dst_port, + src_ip, src_port, &ucred_lookup, +#ifdef __FreeBSD__ + &ucred_cache, args->inp); + if (v == 4 /* O_UID */) + key = ucred_cache->cr_uid; + else if (v == 5 /* O_JAIL */) + key = ucred_cache->cr_prison->pr_id; +#else /* !__FreeBSD__ */ + (void *)&ucred_cache, + (struct inpcb *)args->m); + if (v ==4 /* O_UID */) + key = ucred_cache.uid; + else if (v == 5 /* O_JAIL */) + key = ucred_cache.xid; +#endif /* !__FreeBSD__ */ + key = htonl(key); + } else + break; + } + match = ipfw_lookup_table(chain, + cmd->arg1, key, &v); + if (!match) + break; + if (cmdlen == F_INSN_SIZE(ipfw_insn_u32)) + match = + ((ipfw_insn_u32 *)cmd)->d[0] == v; + else + tablearg = v; + } + break; + + case O_IP_SRC_MASK: + case O_IP_DST_MASK: + if (is_ipv4) { + uint32_t a = + (cmd->opcode == O_IP_DST_MASK) ? + dst_ip.s_addr : src_ip.s_addr; + uint32_t *p = ((ipfw_insn_u32 *)cmd)->d; + int i = cmdlen-1; + + for (; !match && i>0; i-= 2, p+= 2) + match = (p[0] == (a & p[1])); + } + break; + + case O_IP_SRC_ME: + if (is_ipv4) { + struct ifnet *tif; + + INADDR_TO_IFP(src_ip, tif); + match = (tif != NULL); + break; + } +#ifdef INET6 + /* FALLTHROUGH */ + case O_IP6_SRC_ME: + match= is_ipv6 && search_ip6_addr_net(&args->f_id.src_ip6); +#endif + break; + + case O_IP_DST_SET: + case O_IP_SRC_SET: + if (is_ipv4) { + u_int32_t *d = (u_int32_t *)(cmd+1); + u_int32_t addr = + cmd->opcode == O_IP_DST_SET ? + args->f_id.dst_ip : + args->f_id.src_ip; + + if (addr < d[0]) + break; + addr -= d[0]; /* subtract base */ + match = (addr < cmd->arg1) && + ( d[ 1 + (addr>>5)] & + (1<<(addr & 0x1f)) ); + } + break; + + case O_IP_DST: + match = is_ipv4 && + (((ipfw_insn_ip *)cmd)->addr.s_addr == + dst_ip.s_addr); + break; + + case O_IP_DST_ME: + if (is_ipv4) { + struct ifnet *tif; + + INADDR_TO_IFP(dst_ip, tif); + match = (tif != NULL); + break; + } +#ifdef INET6 + /* FALLTHROUGH */ + case O_IP6_DST_ME: + match= is_ipv6 && search_ip6_addr_net(&args->f_id.dst_ip6); +#endif + break; + + + case O_IP_SRCPORT: + case O_IP_DSTPORT: + /* + * offset == 0 && proto != 0 is enough + * to guarantee that we have a + * packet with port info. + */ + if ((proto==IPPROTO_UDP || proto==IPPROTO_TCP) + && offset == 0) { + u_int16_t x = + (cmd->opcode == O_IP_SRCPORT) ? + src_port : dst_port ; + u_int16_t *p = + ((ipfw_insn_u16 *)cmd)->ports; + int i; + + for (i = cmdlen - 1; !match && i>0; + i--, p += 2) + match = (x>=p[0] && x<=p[1]); + } + break; + + case O_ICMPTYPE: + match = (offset == 0 && proto==IPPROTO_ICMP && + icmptype_match(ICMP(ulp), (ipfw_insn_u32 *)cmd) ); + break; + +#ifdef INET6 + case O_ICMP6TYPE: + match = is_ipv6 && offset == 0 && + proto==IPPROTO_ICMPV6 && + icmp6type_match( + ICMP6(ulp)->icmp6_type, + (ipfw_insn_u32 *)cmd); + break; +#endif /* INET6 */ + + case O_IPOPT: + match = (is_ipv4 && + ipopts_match(ip, cmd) ); + break; + + case O_IPVER: + match = (is_ipv4 && + cmd->arg1 == ip->ip_v); + break; + + case O_IPID: + case O_IPLEN: + case O_IPTTL: + if (is_ipv4) { /* only for IP packets */ + uint16_t x; + uint16_t *p; + int i; + + if (cmd->opcode == O_IPLEN) + x = iplen; + else if (cmd->opcode == O_IPTTL) + x = ip->ip_ttl; + else /* must be IPID */ + x = ntohs(ip->ip_id); + if (cmdlen == 1) { + match = (cmd->arg1 == x); + break; + } + /* otherwise we have ranges */ + p = ((ipfw_insn_u16 *)cmd)->ports; + i = cmdlen - 1; + for (; !match && i>0; i--, p += 2) + match = (x >= p[0] && x <= p[1]); + } + break; + + case O_IPPRECEDENCE: + match = (is_ipv4 && + (cmd->arg1 == (ip->ip_tos & 0xe0)) ); + break; + + case O_IPTOS: + match = (is_ipv4 && + flags_match(cmd, ip->ip_tos)); + break; + + case O_TCPDATALEN: + if (proto == IPPROTO_TCP && offset == 0) { + struct tcphdr *tcp; + uint16_t x; + uint16_t *p; + int i; + + tcp = TCP(ulp); + x = iplen - + ((ip->ip_hl + tcp->th_off) << 2); + if (cmdlen == 1) { + match = (cmd->arg1 == x); + break; + } + /* otherwise we have ranges */ + p = ((ipfw_insn_u16 *)cmd)->ports; + i = cmdlen - 1; + for (; !match && i>0; i--, p += 2) + match = (x >= p[0] && x <= p[1]); + } + break; + + case O_TCPFLAGS: + match = (proto == IPPROTO_TCP && offset == 0 && + flags_match(cmd, TCP(ulp)->th_flags)); + break; + + case O_TCPOPTS: + match = (proto == IPPROTO_TCP && offset == 0 && + tcpopts_match(TCP(ulp), cmd)); + break; + + case O_TCPSEQ: + match = (proto == IPPROTO_TCP && offset == 0 && + ((ipfw_insn_u32 *)cmd)->d[0] == + TCP(ulp)->th_seq); + break; + + case O_TCPACK: + match = (proto == IPPROTO_TCP && offset == 0 && + ((ipfw_insn_u32 *)cmd)->d[0] == + TCP(ulp)->th_ack); + break; + + case O_TCPWIN: + match = (proto == IPPROTO_TCP && offset == 0 && + cmd->arg1 == TCP(ulp)->th_win); + break; + + case O_ESTAB: + /* reject packets which have SYN only */ + /* XXX should i also check for TH_ACK ? */ + match = (proto == IPPROTO_TCP && offset == 0 && + (TCP(ulp)->th_flags & + (TH_RST | TH_ACK | TH_SYN)) != TH_SYN); + break; + + case O_ALTQ: { + struct pf_mtag *at; + ipfw_insn_altq *altq = (ipfw_insn_altq *)cmd; + + match = 1; + at = pf_find_mtag(m); + if (at != NULL && at->qid != 0) + break; + at = pf_get_mtag(m); + if (at == NULL) { + /* + * Let the packet fall back to the + * default ALTQ. + */ + break; + } + at->qid = altq->qid; + if (is_ipv4) + at->af = AF_INET; + else + at->af = AF_LINK; + at->hdr = ip; + break; + } + + case O_LOG: + ipfw_log(f, hlen, args, m, + oif, offset, tablearg, ip); + match = 1; + break; + + case O_PROB: + match = (random()<((ipfw_insn_u32 *)cmd)->d[0]); + break; + + case O_VERREVPATH: + /* Outgoing packets automatically pass/match */ + match = ((oif != NULL) || + (m->m_pkthdr.rcvif == NULL) || + ( +#ifdef INET6 + is_ipv6 ? + verify_path6(&(args->f_id.src_ip6), + m->m_pkthdr.rcvif) : +#endif + verify_path(src_ip, m->m_pkthdr.rcvif, + args->f_id.fib))); + break; + + case O_VERSRCREACH: + /* Outgoing packets automatically pass/match */ + match = (hlen > 0 && ((oif != NULL) || +#ifdef INET6 + is_ipv6 ? + verify_path6(&(args->f_id.src_ip6), + NULL) : +#endif + verify_path(src_ip, NULL, args->f_id.fib))); + break; + + case O_ANTISPOOF: + /* Outgoing packets automatically pass/match */ + if (oif == NULL && hlen > 0 && + ( (is_ipv4 && in_localaddr(src_ip)) +#ifdef INET6 + || (is_ipv6 && + in6_localaddr(&(args->f_id.src_ip6))) +#endif + )) + match = +#ifdef INET6 + is_ipv6 ? verify_path6( + &(args->f_id.src_ip6), + m->m_pkthdr.rcvif) : +#endif + verify_path(src_ip, + m->m_pkthdr.rcvif, + args->f_id.fib); + else + match = 1; + break; + + case O_IPSEC: +#ifdef IPSEC + match = (m_tag_find(m, + PACKET_TAG_IPSEC_IN_DONE, NULL) != NULL); +#endif + /* otherwise no match */ + break; + +#ifdef INET6 + case O_IP6_SRC: + match = is_ipv6 && + IN6_ARE_ADDR_EQUAL(&args->f_id.src_ip6, + &((ipfw_insn_ip6 *)cmd)->addr6); + break; + + case O_IP6_DST: + match = is_ipv6 && + IN6_ARE_ADDR_EQUAL(&args->f_id.dst_ip6, + &((ipfw_insn_ip6 *)cmd)->addr6); + break; + case O_IP6_SRC_MASK: + case O_IP6_DST_MASK: + if (is_ipv6) { + int i = cmdlen - 1; + struct in6_addr p; + struct in6_addr *d = + &((ipfw_insn_ip6 *)cmd)->addr6; + + for (; !match && i > 0; d += 2, + i -= F_INSN_SIZE(struct in6_addr) + * 2) { + p = (cmd->opcode == + O_IP6_SRC_MASK) ? + args->f_id.src_ip6: + args->f_id.dst_ip6; + APPLY_MASK(&p, &d[1]); + match = + IN6_ARE_ADDR_EQUAL(&d[0], + &p); + } + } + break; + + case O_FLOW6ID: + match = is_ipv6 && + flow6id_match(args->f_id.flow_id6, + (ipfw_insn_u32 *) cmd); + break; + + case O_EXT_HDR: + match = is_ipv6 && + (ext_hd & ((ipfw_insn *) cmd)->arg1); + break; + + case O_IP6: + match = is_ipv6; + break; +#endif + + case O_IP4: + match = is_ipv4; + break; + + case O_TAG: { + struct m_tag *mtag; + uint32_t tag = (cmd->arg1 == IP_FW_TABLEARG) ? + tablearg : cmd->arg1; + + /* Packet is already tagged with this tag? */ + mtag = m_tag_locate(m, MTAG_IPFW, tag, NULL); + + /* We have `untag' action when F_NOT flag is + * present. And we must remove this mtag from + * mbuf and reset `match' to zero (`match' will + * be inversed later). + * Otherwise we should allocate new mtag and + * push it into mbuf. + */ + if (cmd->len & F_NOT) { /* `untag' action */ + if (mtag != NULL) + m_tag_delete(m, mtag); + match = 0; + } else if (mtag == NULL) { + if ((mtag = m_tag_alloc(MTAG_IPFW, + tag, 0, M_NOWAIT)) != NULL) + m_tag_prepend(m, mtag); + match = 1; + } + break; + } + + case O_FIB: /* try match the specified fib */ + if (args->f_id.fib == cmd->arg1) + match = 1; + break; + + case O_TAGGED: { + struct m_tag *mtag; + uint32_t tag = (cmd->arg1 == IP_FW_TABLEARG) ? + tablearg : cmd->arg1; + + if (cmdlen == 1) { + match = m_tag_locate(m, MTAG_IPFW, + tag, NULL) != NULL; + break; + } + + /* we have ranges */ + for (mtag = m_tag_first(m); + mtag != NULL && !match; + mtag = m_tag_next(m, mtag)) { + uint16_t *p; + int i; + + if (mtag->m_tag_cookie != MTAG_IPFW) + continue; + + p = ((ipfw_insn_u16 *)cmd)->ports; + i = cmdlen - 1; + for(; !match && i > 0; i--, p += 2) + match = + mtag->m_tag_id >= p[0] && + mtag->m_tag_id <= p[1]; + } + break; + } + + /* + * The second set of opcodes represents 'actions', + * i.e. the terminal part of a rule once the packet + * matches all previous patterns. + * Typically there is only one action for each rule, + * and the opcode is stored at the end of the rule + * (but there are exceptions -- see below). + * + * In general, here we set retval and terminate the + * outer loop (would be a 'break 3' in some language, + * but we need to set l=0, done=1) + * + * Exceptions: + * O_COUNT and O_SKIPTO actions: + * instead of terminating, we jump to the next rule + * (setting l=0), or to the SKIPTO target (setting + * f/f_len, cmd and l as needed), respectively. + * + * O_TAG, O_LOG and O_ALTQ action parameters: + * perform some action and set match = 1; + * + * O_LIMIT and O_KEEP_STATE: these opcodes are + * not real 'actions', and are stored right + * before the 'action' part of the rule. + * These opcodes try to install an entry in the + * state tables; if successful, we continue with + * the next opcode (match=1; break;), otherwise + * the packet must be dropped (set retval, + * break loops with l=0, done=1) + * + * O_PROBE_STATE and O_CHECK_STATE: these opcodes + * cause a lookup of the state table, and a jump + * to the 'action' part of the parent rule + * if an entry is found, or + * (CHECK_STATE only) a jump to the next rule if + * the entry is not found. + * The result of the lookup is cached so that + * further instances of these opcodes become NOPs. + * The jump to the next rule is done by setting + * l=0, cmdlen=0. + */ + case O_LIMIT: + case O_KEEP_STATE: + if (ipfw_install_state(f, + (ipfw_insn_limit *)cmd, args, tablearg)) { + /* error or limit violation */ + retval = IP_FW_DENY; + l = 0; /* exit inner loop */ + done = 1; /* exit outer loop */ + } + match = 1; + break; + + case O_PROBE_STATE: + case O_CHECK_STATE: + /* + * dynamic rules are checked at the first + * keep-state or check-state occurrence, + * with the result being stored in dyn_dir. + * The compiler introduces a PROBE_STATE + * instruction for us when we have a + * KEEP_STATE (because PROBE_STATE needs + * to be run first). + */ + if (dyn_dir == MATCH_UNKNOWN && + (q = ipfw_lookup_dyn_rule(&args->f_id, + &dyn_dir, proto == IPPROTO_TCP ? + TCP(ulp) : NULL)) + != NULL) { + /* + * Found dynamic entry, update stats + * and jump to the 'action' part of + * the parent rule by setting + * f, cmd, l and clearing cmdlen. + */ + q->pcnt++; + q->bcnt += pktlen; + /* XXX we would like to have f_pos + * readily accessible in the dynamic + * rule, instead of having to + * lookup q->rule. + */ + f = q->rule; + f_pos = ipfw_find_rule(chain, + f->rulenum, f->id); + cmd = ACTION_PTR(f); + l = f->cmd_len - f->act_ofs; + ipfw_dyn_unlock(); + cmdlen = 0; + match = 1; + break; + } + /* + * Dynamic entry not found. If CHECK_STATE, + * skip to next rule, if PROBE_STATE just + * ignore and continue with next opcode. + */ + if (cmd->opcode == O_CHECK_STATE) + l = 0; /* exit inner loop */ + match = 1; + break; + + case O_ACCEPT: + retval = 0; /* accept */ + l = 0; /* exit inner loop */ + done = 1; /* exit outer loop */ + break; + + case O_PIPE: + case O_QUEUE: + set_match(args, f_pos, chain); + args->rule.info = (cmd->arg1 == IP_FW_TABLEARG) ? + tablearg : cmd->arg1; + if (cmd->opcode == O_PIPE) + args->rule.info |= IPFW_IS_PIPE; + if (V_fw_one_pass) + args->rule.info |= IPFW_ONEPASS; + retval = IP_FW_DUMMYNET; + l = 0; /* exit inner loop */ + done = 1; /* exit outer loop */ + break; + + case O_DIVERT: + case O_TEE: + if (args->eh) /* not on layer 2 */ + break; + /* otherwise this is terminal */ + l = 0; /* exit inner loop */ + done = 1; /* exit outer loop */ + retval = (cmd->opcode == O_DIVERT) ? + IP_FW_DIVERT : IP_FW_TEE; + set_match(args, f_pos, chain); + args->rule.info = (cmd->arg1 == IP_FW_TABLEARG) ? + tablearg : cmd->arg1; + break; + + case O_COUNT: + f->pcnt++; /* update stats */ + f->bcnt += pktlen; + f->timestamp = time_uptime; + l = 0; /* exit inner loop */ + break; + + case O_SKIPTO: + f->pcnt++; /* update stats */ + f->bcnt += pktlen; + f->timestamp = time_uptime; + /* If possible use cached f_pos (in f->next_rule), + * whose version is written in f->next_rule + * (horrible hacks to avoid changing the ABI). + */ + if (cmd->arg1 != IP_FW_TABLEARG && + (uintptr_t)f->x_next == chain->id) { + f_pos = (uintptr_t)f->next_rule; + } else { + int i = (cmd->arg1 == IP_FW_TABLEARG) ? + tablearg : cmd->arg1; + /* make sure we do not jump backward */ + if (i <= f->rulenum) + i = f->rulenum + 1; + f_pos = ipfw_find_rule(chain, i, 0); + /* update the cache */ + if (cmd->arg1 != IP_FW_TABLEARG) { + f->next_rule = + (void *)(uintptr_t)f_pos; + f->x_next = + (void *)(uintptr_t)chain->id; + } + } + /* + * Skip disabled rules, and re-enter + * the inner loop with the correct + * f_pos, f, l and cmd. + * Also clear cmdlen and skip_or + */ + for (; f_pos < chain->n_rules - 1 && + (V_set_disable & + (1 << chain->map[f_pos]->set)); + f_pos++) + ; + /* Re-enter the inner loop at the skipto rule. */ + f = chain->map[f_pos]; + l = f->cmd_len; + cmd = f->cmd; + match = 1; + cmdlen = 0; + skip_or = 0; + continue; + break; /* not reached */ + + case O_REJECT: + /* + * Drop the packet and send a reject notice + * if the packet is not ICMP (or is an ICMP + * query), and it is not multicast/broadcast. + */ + if (hlen > 0 && is_ipv4 && offset == 0 && + (proto != IPPROTO_ICMP || + is_icmp_query(ICMP(ulp))) && + !(m->m_flags & (M_BCAST|M_MCAST)) && + !IN_MULTICAST(ntohl(dst_ip.s_addr))) { + send_reject(args, cmd->arg1, iplen, ip); + m = args->m; + } + /* FALLTHROUGH */ +#ifdef INET6 + case O_UNREACH6: + if (hlen > 0 && is_ipv6 && + ((offset & IP6F_OFF_MASK) == 0) && + (proto != IPPROTO_ICMPV6 || + (is_icmp6_query(icmp6_type) == 1)) && + !(m->m_flags & (M_BCAST|M_MCAST)) && + !IN6_IS_ADDR_MULTICAST(&args->f_id.dst_ip6)) { + send_reject6( + args, cmd->arg1, hlen, + (struct ip6_hdr *)ip); + m = args->m; + } + /* FALLTHROUGH */ +#endif + case O_DENY: + retval = IP_FW_DENY; + l = 0; /* exit inner loop */ + done = 1; /* exit outer loop */ + break; + + case O_FORWARD_IP: + if (args->eh) /* not valid on layer2 pkts */ + break; + if (!q || dyn_dir == MATCH_FORWARD) { + struct sockaddr_in *sa; + sa = &(((ipfw_insn_sa *)cmd)->sa); + if (sa->sin_addr.s_addr == INADDR_ANY) { + bcopy(sa, &args->hopstore, + sizeof(*sa)); + args->hopstore.sin_addr.s_addr = + htonl(tablearg); + args->next_hop = &args->hopstore; + } else { + args->next_hop = sa; + } + } + retval = IP_FW_PASS; + l = 0; /* exit inner loop */ + done = 1; /* exit outer loop */ + break; + + case O_NETGRAPH: + case O_NGTEE: + set_match(args, f_pos, chain); + args->rule.info = (cmd->arg1 == IP_FW_TABLEARG) ? + tablearg : cmd->arg1; + if (V_fw_one_pass) + args->rule.info |= IPFW_ONEPASS; + retval = (cmd->opcode == O_NETGRAPH) ? + IP_FW_NETGRAPH : IP_FW_NGTEE; + l = 0; /* exit inner loop */ + done = 1; /* exit outer loop */ + break; + + case O_SETFIB: + f->pcnt++; /* update stats */ + f->bcnt += pktlen; + f->timestamp = time_uptime; + M_SETFIB(m, cmd->arg1); + args->f_id.fib = cmd->arg1; + l = 0; /* exit inner loop */ + break; + + case O_NAT: + if (!IPFW_NAT_LOADED) { + retval = IP_FW_DENY; + } else { + struct cfg_nat *t; + int nat_id; + + set_match(args, f_pos, chain); + t = ((ipfw_insn_nat *)cmd)->nat; + if (t == NULL) { + nat_id = (cmd->arg1 == IP_FW_TABLEARG) ? + tablearg : cmd->arg1; + t = (*lookup_nat_ptr)(&chain->nat, nat_id); + + if (t == NULL) { + retval = IP_FW_DENY; + l = 0; /* exit inner loop */ + done = 1; /* exit outer loop */ + break; + } + if (cmd->arg1 != IP_FW_TABLEARG) + ((ipfw_insn_nat *)cmd)->nat = t; + } + retval = ipfw_nat_ptr(args, t, m); + } + l = 0; /* exit inner loop */ + done = 1; /* exit outer loop */ + break; + + case O_REASS: { + int ip_off; + + f->pcnt++; + f->bcnt += pktlen; + l = 0; /* in any case exit inner loop */ + ip_off = ntohs(ip->ip_off); + + /* if not fragmented, go to next rule */ + if ((ip_off & (IP_MF | IP_OFFMASK)) == 0) + break; + /* + * ip_reass() expects len & off in host + * byte order. + */ + SET_HOST_IPLEN(ip); + + args->m = m = ip_reass(m); + + /* + * do IP header checksum fixup. + */ + if (m == NULL) { /* fragment got swallowed */ + retval = IP_FW_DENY; + } else { /* good, packet complete */ + int hlen; + + ip = mtod(m, struct ip *); + hlen = ip->ip_hl << 2; + SET_NET_IPLEN(ip); + ip->ip_sum = 0; + if (hlen == sizeof(struct ip)) + ip->ip_sum = in_cksum_hdr(ip); + else + ip->ip_sum = in_cksum(m, hlen); + retval = IP_FW_REASS; + set_match(args, f_pos, chain); + } + done = 1; /* exit outer loop */ + break; + } + + default: + panic("-- unknown opcode %d\n", cmd->opcode); + } /* end of switch() on opcodes */ + /* + * if we get here with l=0, then match is irrelevant. + */ + + if (cmd->len & F_NOT) + match = !match; + + if (match) { + if (cmd->len & F_OR) + skip_or = 1; + } else { + if (!(cmd->len & F_OR)) /* not an OR block, */ + break; /* try next rule */ + } + + } /* end of inner loop, scan opcodes */ + + if (done) + break; + +/* next_rule:; */ /* try next rule */ + + } /* end of outer for, scan rules */ + + if (done) { + struct ip_fw *rule = chain->map[f_pos]; + /* Update statistics */ + rule->pcnt++; + rule->bcnt += pktlen; + rule->timestamp = time_uptime; + } else { + retval = IP_FW_DENY; + printf("ipfw: ouch!, skip past end of rules, denying packet\n"); + } + IPFW_RUNLOCK(chain); +#ifdef __FreeBSD__ + if (ucred_cache != NULL) + crfree(ucred_cache); +#endif + return (retval); + +pullup_failed: + if (V_fw_verbose) + printf("ipfw: pullup failed\n"); + return (IP_FW_DENY); +} + +/* + * Module and VNET glue + */ + +/* + * Stuff that must be initialised only on boot or module load + */ +static int +ipfw_init(void) +{ + int error = 0; + + ipfw_dyn_attach(); + /* + * Only print out this stuff the first time around, + * when called from the sysinit code. + */ + printf("ipfw2 " +#ifdef INET6 + "(+ipv6) " +#endif + "initialized, divert %s, nat %s, " + "rule-based forwarding " +#ifdef IPFIREWALL_FORWARD + "enabled, " +#else + "disabled, " +#endif + "default to %s, logging ", +#ifdef IPDIVERT + "enabled", +#else + "loadable", +#endif +#ifdef IPFIREWALL_NAT + "enabled", +#else + "loadable", +#endif + default_to_accept ? "accept" : "deny"); + + /* + * Note: V_xxx variables can be accessed here but the vnet specific + * initializer may not have been called yet for the VIMAGE case. + * Tuneables will have been processed. We will print out values for + * the default vnet. + * XXX This should all be rationalized AFTER 8.0 + */ + if (V_fw_verbose == 0) + printf("disabled\n"); + else if (V_verbose_limit == 0) + printf("unlimited\n"); + else + printf("limited to %d packets/entry by default\n", + V_verbose_limit); + + ipfw_log_bpf(1); /* init */ + return (error); +} + +/* + * Called for the removal of the last instance only on module unload. + */ +static void +ipfw_destroy(void) +{ + + ipfw_log_bpf(0); /* uninit */ + ipfw_dyn_detach(); + printf("IP firewall unloaded\n"); +} + +/* + * Stuff that must be initialized for every instance + * (including the first of course). + */ +static int +vnet_ipfw_init(const void *unused) +{ + int error; + struct ip_fw *rule = NULL; + struct ip_fw_chain *chain; + + chain = &V_layer3_chain; + + /* First set up some values that are compile time options */ + V_autoinc_step = 100; /* bounded to 1..1000 in add_rule() */ + V_fw_deny_unknown_exthdrs = 1; +#ifdef IPFIREWALL_VERBOSE + V_fw_verbose = 1; +#endif +#ifdef IPFIREWALL_VERBOSE_LIMIT + V_verbose_limit = IPFIREWALL_VERBOSE_LIMIT; +#endif +#ifdef IPFIREWALL_NAT + LIST_INIT(&chain->nat); +#endif + + /* insert the default rule and create the initial map */ + chain->n_rules = 1; + chain->static_len = sizeof(struct ip_fw); + chain->map = malloc(sizeof(struct ip_fw *), M_IPFW, M_NOWAIT | M_ZERO); + if (chain->map) + rule = malloc(chain->static_len, M_IPFW, M_NOWAIT | M_ZERO); + if (rule == NULL) { + if (chain->map) + free(chain->map, M_IPFW); + printf("ipfw2: ENOSPC initializing default rule " + "(support disabled)\n"); + return (ENOSPC); + } + error = ipfw_init_tables(chain); + if (error) { + panic("init_tables"); /* XXX Marko fix this ! */ + } + + /* fill and insert the default rule */ + rule->act_ofs = 0; + rule->rulenum = IPFW_DEFAULT_RULE; + rule->cmd_len = 1; + rule->set = RESVD_SET; + rule->cmd[0].len = 1; + rule->cmd[0].opcode = default_to_accept ? O_ACCEPT : O_DENY; + chain->rules = chain->default_rule = chain->map[0] = rule; + chain->id = rule->id = 1; + + IPFW_LOCK_INIT(chain); + ipfw_dyn_init(); + + /* First set up some values that are compile time options */ + V_ipfw_vnet_ready = 1; /* Open for business */ + + /* + * Hook the sockopt handler, and the layer2 (V_ip_fw_chk_ptr) + * and pfil hooks for ipv4 and ipv6. Even if the latter two fail + * we still keep the module alive because the sockopt and + * layer2 paths are still useful. + * ipfw[6]_hook return 0 on success, ENOENT on failure, + * so we can ignore the exact return value and just set a flag. + * + * Note that V_fw[6]_enable are manipulated by a SYSCTL_PROC so + * changes in the underlying (per-vnet) variables trigger + * immediate hook()/unhook() calls. + * In layer2 we have the same behaviour, except that V_ether_ipfw + * is checked on each packet because there are no pfil hooks. + */ + V_ip_fw_ctl_ptr = ipfw_ctl; + V_ip_fw_chk_ptr = ipfw_chk; + error = ipfw_attach_hooks(1); + return (error); +} + +/* + * Called for the removal of each instance. + */ +static int +vnet_ipfw_uninit(const void *unused) +{ + struct ip_fw *reap, *rule; + struct ip_fw_chain *chain = &V_layer3_chain; + int i; + + V_ipfw_vnet_ready = 0; /* tell new callers to go away */ + /* + * disconnect from ipv4, ipv6, layer2 and sockopt. + * Then grab, release and grab again the WLOCK so we make + * sure the update is propagated and nobody will be in. + */ + (void)ipfw_attach_hooks(0 /* detach */); + V_ip_fw_chk_ptr = NULL; + V_ip_fw_ctl_ptr = NULL; + IPFW_UH_WLOCK(chain); + IPFW_UH_WUNLOCK(chain); + IPFW_UH_WLOCK(chain); + + IPFW_WLOCK(chain); + IPFW_WUNLOCK(chain); + IPFW_WLOCK(chain); + + ipfw_dyn_uninit(0); /* run the callout_drain */ + ipfw_destroy_tables(chain); + reap = NULL; + for (i = 0; i < chain->n_rules; i++) { + rule = chain->map[i]; + rule->x_next = reap; + reap = rule; + } + if (chain->map) + free(chain->map, M_IPFW); + IPFW_WUNLOCK(chain); + IPFW_UH_WUNLOCK(chain); + if (reap != NULL) + ipfw_reap_rules(reap); + IPFW_LOCK_DESTROY(chain); + ipfw_dyn_uninit(1); /* free the remaining parts */ + return 0; +} + +/* + * Module event handler. + * In general we have the choice of handling most of these events by the + * event handler or by the (VNET_)SYS(UN)INIT handlers. I have chosen to + * use the SYSINIT handlers as they are more capable of expressing the + * flow of control during module and vnet operations, so this is just + * a skeleton. Note there is no SYSINIT equivalent of the module + * SHUTDOWN handler, but we don't have anything to do in that case anyhow. + */ +static int +ipfw_modevent(module_t mod, int type, void *unused) +{ + int err = 0; + + switch (type) { + case MOD_LOAD: + /* Called once at module load or + * system boot if compiled in. */ + break; + case MOD_QUIESCE: + /* Called before unload. May veto unloading. */ + break; + case MOD_UNLOAD: + /* Called during unload. */ + break; + case MOD_SHUTDOWN: + /* Called during system shutdown. */ + break; + default: + err = EOPNOTSUPP; + break; + } + return err; +} + +static moduledata_t ipfwmod = { + "ipfw", + ipfw_modevent, + 0 +}; + +/* Define startup order. */ +#define IPFW_SI_SUB_FIREWALL SI_SUB_PROTO_IFATTACHDOMAIN +#define IPFW_MODEVENT_ORDER (SI_ORDER_ANY - 255) /* On boot slot in here. */ +#define IPFW_MODULE_ORDER (IPFW_MODEVENT_ORDER + 1) /* A little later. */ +#define IPFW_VNET_ORDER (IPFW_MODEVENT_ORDER + 2) /* Later still. */ + +DECLARE_MODULE(ipfw, ipfwmod, IPFW_SI_SUB_FIREWALL, IPFW_MODEVENT_ORDER); +MODULE_VERSION(ipfw, 2); +/* should declare some dependencies here */ + +/* + * Starting up. Done in order after ipfwmod() has been called. + * VNET_SYSINIT is also called for each existing vnet and each new vnet. + */ +SYSINIT(ipfw_init, IPFW_SI_SUB_FIREWALL, IPFW_MODULE_ORDER, + ipfw_init, NULL); +VNET_SYSINIT(vnet_ipfw_init, IPFW_SI_SUB_FIREWALL, IPFW_VNET_ORDER, + vnet_ipfw_init, NULL); + +/* + * Closing up shop. These are done in REVERSE ORDER, but still + * after ipfwmod() has been called. Not called on reboot. + * VNET_SYSUNINIT is also called for each exiting vnet as it exits. + * or when the module is unloaded. + */ +SYSUNINIT(ipfw_destroy, IPFW_SI_SUB_FIREWALL, IPFW_MODULE_ORDER, + ipfw_destroy, NULL); +VNET_SYSUNINIT(vnet_ipfw_uninit, IPFW_SI_SUB_FIREWALL, IPFW_VNET_ORDER, + vnet_ipfw_uninit, NULL); +/* end of file */ |