--- /dev/null
+/*-
+ * 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 <sys/cdefs.h>
+__FBSDID("$FreeBSD: head/sys/netinet/ipfw/ip_fw2.c 200601 2009-12-16 10:48:40Z luigi $");
+
+/*
+ * The FreeBSD IP packet firewall, main file
+ */
+
+#if !defined(KLD_MODULE)
+#include "opt_ipfw.h"
+#include "opt_ipdivert.h"
+#include "opt_ipdn.h"
+#include "opt_inet.h"
+#ifndef INET
+#error IPFIREWALL requires INET.
+#endif /* INET */
+#endif
+#include "opt_inet6.h"
+#include "opt_ipsec.h"
+
+#include <sys/param.h>
+#include <sys/systm.h>
+#include <sys/condvar.h>
+#include <sys/eventhandler.h>
+#include <sys/malloc.h>
+#include <sys/mbuf.h>
+#include <sys/kernel.h>
+#include <sys/lock.h>
+#include <sys/jail.h>
+#include <sys/module.h>
+#include <sys/priv.h>
+#include <sys/proc.h>
+#include <sys/rwlock.h>
+#include <sys/socket.h>
+#include <sys/socketvar.h>
+#include <sys/sysctl.h>
+#include <sys/syslog.h>
+#include <sys/ucred.h>
+#include <net/ethernet.h> /* for ETHERTYPE_IP */
+#include <net/if.h>
+#include <net/route.h>
+#include <net/pf_mtag.h>
+#include <net/vnet.h>
+
+#include <netinet/in.h>
+#include <netinet/in_var.h>
+#include <netinet/in_pcb.h>
+#include <netinet/ip.h>
+#include <netinet/ip_var.h>
+#include <netinet/ip_icmp.h>
+#include <netinet/ip_fw.h>
+#include <netinet/ipfw/ip_fw_private.h>
+#include <netinet/ip_carp.h>
+#include <netinet/pim.h>
+#include <netinet/tcp_var.h>
+#include <netinet/udp.h>
+#include <netinet/udp_var.h>
+#include <netinet/sctp.h>
+
+#include <netinet/ip6.h>
+#include <netinet/icmp6.h>
+#ifdef INET6
+#include <netinet6/scope6_var.h>
+#include <netinet6/ip6_var.h>
+#endif
+
+#include <machine/in_cksum.h> /* XXX for in_cksum */
+
+#ifdef MAC
+#include <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
+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");
+uint32_t dummy_def = IPFW_DEFAULT_RULE;
+SYSCTL_UINT(_net_inet_ip_fw, OID_AUTO, default_rule, CTLFLAG_RD,
+ &dummy_def, 0,
+ "The default/max possible rule number.");
+uint32_t dummy_tables_max = IPFW_TABLES_MAX;
+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 */
+
+#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 {
+#if !defined( __linux__ ) && !defined( _WIN32 )
+ 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
+ }
+ 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)
+{
+#if defined( __linux__ ) || defined( _WIN32 )
+ 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
+}
+
+#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, struct ucred **uc, int *ugid_lookupp,
+ struct inpcb *inp)
+{
+#ifdef __linux__
+ 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
+}
+
+/*
+ * 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.
+ */
+#ifdef __linux__
+ 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;
+ u_int16_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);
+ args->f_id.flags = 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;
+ 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.frag_id6 =
+ 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;
+ 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, (void *)&ucred_cache,
+ &ucred_lookup, (struct inpcb *)args->m);
+ 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 (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, (void *)&ucred_cache,
+ &ucred_lookup, (struct inpcb *)args->m);
+#ifdef __linux__
+ if (v ==4 /* O_UID */)
+ key = ucred_cache.uid;
+ else if (v == 5 /* O_JAIL */)
+ key = ucred_cache.xid;
+#else
+ if (v == 4 /* O_UID */)
+ key = ucred_cache->cr_uid;
+ else if (v == 5 /* O_JAIL */)
+ key = ucred_cache->cr_prison->pr_id;
+#endif
+ 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;
+
+ 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;
+
+ 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_IP6_SRC_ME:
+ match= is_ipv6 && search_ip6_addr_net(&args->f_id.src_ip6);
+ break;
+
+ case O_IP6_DST_ME:
+ match= is_ipv6 && search_ip6_addr_net(&args->f_id.dst_ip6);
+ 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++)
+ ;
+ /* prepare to enter the inner loop */
+ f = chain->map[f_pos];
+ l = f->cmd_len;
+ cmd = f->cmd;
+ match = 1;
+ cmdlen = 0;
+ skip_or = 0;
+ break;
+
+ 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(args->f_id.flags) == 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;
+ 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);
+#ifndef __linux__
+ 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_flush_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 */
git://git.onelab.eu / ipfw.git / blobdiff