diff --git a/sys/netpfil/ipfw/ip_fw_pfil.c b/sys/netpfil/ipfw/ip_fw_pfil.c index e21831c80ec6..01a44df47180 100644 --- a/sys/netpfil/ipfw/ip_fw_pfil.c +++ b/sys/netpfil/ipfw/ip_fw_pfil.c @@ -1,700 +1,702 @@ /*- * SPDX-License-Identifier: BSD-2-Clause-FreeBSD * * Copyright (c) 2004 Andre Oppermann, Internet Business Solutions AG * All rights reserved. * * 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 __FBSDID("$FreeBSD$"); #include "opt_ipfw.h" #include "opt_inet.h" #include "opt_inet6.h" #ifndef INET #error IPFIREWALL requires INET. #endif /* INET */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #ifdef INET6 #include #include #include #endif #include #include #include VNET_DEFINE_STATIC(int, fw_enable) = 1; #define V_fw_enable VNET(fw_enable) #ifdef INET6 VNET_DEFINE_STATIC(int, fw6_enable) = 1; #define V_fw6_enable VNET(fw6_enable) #endif VNET_DEFINE_STATIC(int, fwlink_enable) = 0; #define V_fwlink_enable VNET(fwlink_enable) int ipfw_chg_hook(SYSCTL_HANDLER_ARGS); /* Forward declarations. */ static int ipfw_divert(struct mbuf **, struct ip_fw_args *, bool); #ifdef SYSCTL_NODE SYSBEGIN(f1) SYSCTL_DECL(_net_inet_ip_fw); SYSCTL_PROC(_net_inet_ip_fw, OID_AUTO, enable, CTLFLAG_VNET | CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_SECURE3 | CTLFLAG_NEEDGIANT, &VNET_NAME(fw_enable), 0, ipfw_chg_hook, "I", "Enable ipfw"); #ifdef INET6 SYSCTL_DECL(_net_inet6_ip6_fw); SYSCTL_PROC(_net_inet6_ip6_fw, OID_AUTO, enable, CTLFLAG_VNET | CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_SECURE3 | CTLFLAG_NEEDGIANT, &VNET_NAME(fw6_enable), 0, ipfw_chg_hook, "I", "Enable ipfw+6"); #endif /* INET6 */ SYSCTL_DECL(_net_link_ether); SYSCTL_PROC(_net_link_ether, OID_AUTO, ipfw, CTLFLAG_VNET | CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_SECURE3 | CTLFLAG_NEEDGIANT, &VNET_NAME(fwlink_enable), 0, ipfw_chg_hook, "I", "Pass ether pkts through firewall"); SYSEND #endif /* SYSCTL_NODE */ /* * The pfilter hook to pass packets to ipfw_chk and then to * dummynet, divert, netgraph or other modules. * The packet may be consumed. */ static pfil_return_t ipfw_check_packet(struct mbuf **m0, struct ifnet *ifp, int flags, void *ruleset __unused, struct inpcb *inp) { struct ip_fw_args args; struct m_tag *tag; pfil_return_t ret; int ipfw; args.flags = (flags & PFIL_IN) ? IPFW_ARGS_IN : IPFW_ARGS_OUT; again: /* * extract and remove the tag if present. If we are left * with onepass, optimize the outgoing path. */ tag = m_tag_locate(*m0, MTAG_IPFW_RULE, 0, NULL); if (tag != NULL) { args.rule = *((struct ipfw_rule_ref *)(tag+1)); m_tag_delete(*m0, tag); if (args.rule.info & IPFW_ONEPASS) return (0); args.flags |= IPFW_ARGS_REF; } args.m = *m0; args.ifp = ifp; args.inp = inp; ipfw = ipfw_chk(&args); *m0 = args.m; KASSERT(*m0 != NULL || ipfw == IP_FW_DENY || ipfw == IP_FW_NAT64, ("%s: m0 is NULL", __func__)); ret = PFIL_PASS; switch (ipfw) { case IP_FW_PASS: /* next_hop may be set by ipfw_chk */ if ((args.flags & (IPFW_ARGS_NH4 | IPFW_ARGS_NH4PTR | IPFW_ARGS_NH6 | IPFW_ARGS_NH6PTR)) == 0) break; #if (!defined(INET6) && !defined(INET)) ret = PFIL_DROPPED; #else { void *psa; size_t len; #ifdef INET if (args.flags & (IPFW_ARGS_NH4 | IPFW_ARGS_NH4PTR)) { MPASS((args.flags & (IPFW_ARGS_NH4 | IPFW_ARGS_NH4PTR)) != (IPFW_ARGS_NH4 | IPFW_ARGS_NH4PTR)); MPASS((args.flags & (IPFW_ARGS_NH6 | IPFW_ARGS_NH6PTR)) == 0); len = sizeof(struct sockaddr_in); psa = (args.flags & IPFW_ARGS_NH4) ? &args.hopstore : args.next_hop; if (in_localip(satosin(psa)->sin_addr)) (*m0)->m_flags |= M_FASTFWD_OURS; (*m0)->m_flags |= M_IP_NEXTHOP; } #endif /* INET */ #ifdef INET6 if (args.flags & (IPFW_ARGS_NH6 | IPFW_ARGS_NH6PTR)) { MPASS((args.flags & (IPFW_ARGS_NH6 | IPFW_ARGS_NH6PTR)) != (IPFW_ARGS_NH6 | IPFW_ARGS_NH6PTR)); MPASS((args.flags & (IPFW_ARGS_NH4 | IPFW_ARGS_NH4PTR)) == 0); len = sizeof(struct sockaddr_in6); psa = args.next_hop6; (*m0)->m_flags |= M_IP6_NEXTHOP; } #endif /* INET6 */ /* * Incoming packets should not be tagged so we do not * m_tag_find. Outgoing packets may be tagged, so we * reuse the tag if present. */ tag = (flags & PFIL_IN) ? NULL : m_tag_find(*m0, PACKET_TAG_IPFORWARD, NULL); if (tag != NULL) { m_tag_unlink(*m0, tag); } else { tag = m_tag_get(PACKET_TAG_IPFORWARD, len, M_NOWAIT); if (tag == NULL) { ret = PFIL_DROPPED; break; } } if ((args.flags & IPFW_ARGS_NH6) == 0) bcopy(psa, tag + 1, len); m_tag_prepend(*m0, tag); ret = 0; #ifdef INET6 /* IPv6 next hop needs additional handling */ if (args.flags & (IPFW_ARGS_NH6 | IPFW_ARGS_NH6PTR)) { struct sockaddr_in6 *sa6; sa6 = satosin6(tag + 1); if (args.flags & IPFW_ARGS_NH6) { sa6->sin6_family = AF_INET6; sa6->sin6_len = sizeof(*sa6); sa6->sin6_addr = args.hopstore6.sin6_addr; sa6->sin6_port = args.hopstore6.sin6_port; sa6->sin6_scope_id = args.hopstore6.sin6_scope_id; } /* * If nh6 address is link-local we should convert * it to kernel internal form before doing any * comparisons. */ if (sa6_embedscope(sa6, V_ip6_use_defzone) != 0) { ret = PFIL_DROPPED; break; } if (in6_localip(&sa6->sin6_addr)) (*m0)->m_flags |= M_FASTFWD_OURS; } #endif /* INET6 */ } #endif /* INET || INET6 */ break; case IP_FW_DENY: ret = PFIL_DROPPED; break; case IP_FW_DUMMYNET: if (ip_dn_io_ptr == NULL) { ret = PFIL_DROPPED; break; } MPASS(args.flags & IPFW_ARGS_REF); if (args.flags & (IPFW_ARGS_IP4 | IPFW_ARGS_IP6)) (void )ip_dn_io_ptr(m0, &args); else { ret = PFIL_DROPPED; break; } /* * XXX should read the return value. * dummynet normally eats the packet and sets *m0=NULL * unless the packet can be sent immediately. In this * case args is updated and we should re-run the * check without clearing args. */ if (*m0 != NULL) goto again; ret = PFIL_CONSUMED; break; case IP_FW_TEE: case IP_FW_DIVERT: if (ip_divert_ptr == NULL) { ret = PFIL_DROPPED; break; } MPASS(args.flags & IPFW_ARGS_REF); (void )ipfw_divert(m0, &args, ipfw == IP_FW_TEE); /* continue processing for the original packet (tee). */ if (*m0) goto again; ret = PFIL_CONSUMED; break; case IP_FW_NGTEE: case IP_FW_NETGRAPH: if (ng_ipfw_input_p == NULL) { ret = PFIL_DROPPED; break; } MPASS(args.flags & IPFW_ARGS_REF); (void )ng_ipfw_input_p(m0, &args, ipfw == IP_FW_NGTEE); if (ipfw == IP_FW_NGTEE) /* ignore errors for NGTEE */ goto again; /* continue with packet */ ret = PFIL_CONSUMED; break; case IP_FW_NAT: /* honor one-pass in case of successful nat */ if (V_fw_one_pass) break; goto again; case IP_FW_REASS: goto again; /* continue with packet */ case IP_FW_NAT64: ret = PFIL_CONSUMED; break; default: KASSERT(0, ("%s: unknown retval", __func__)); } if (ret != PFIL_PASS) { if (*m0) FREE_PKT(*m0); *m0 = NULL; } return (ret); } /* * ipfw processing for ethernet packets (in and out). */ static pfil_return_t ipfw_check_frame(pfil_packet_t p, struct ifnet *ifp, int flags, void *ruleset __unused, struct inpcb *inp) { struct ip_fw_args args; pfil_return_t ret; bool mem, realloc; int ipfw; if (flags & PFIL_MEMPTR) { mem = true; realloc = false; args.flags = PFIL_LENGTH(flags) | IPFW_ARGS_ETHER; args.mem = p.mem; } else { mem = realloc = false; args.flags = IPFW_ARGS_ETHER; } args.flags |= (flags & PFIL_IN) ? IPFW_ARGS_IN : IPFW_ARGS_OUT; args.ifp = ifp; args.inp = inp; again: if (!mem) { /* * Fetch start point from rule, if any. * Remove the tag if present. */ struct m_tag *mtag; mtag = m_tag_locate(*p.m, MTAG_IPFW_RULE, 0, NULL); if (mtag != NULL) { args.rule = *((struct ipfw_rule_ref *)(mtag+1)); m_tag_delete(*p.m, mtag); if (args.rule.info & IPFW_ONEPASS) return (PFIL_PASS); args.flags |= IPFW_ARGS_REF; } args.m = *p.m; } ipfw = ipfw_chk(&args); + if (!mem) + *p.m = args.m; ret = PFIL_PASS; switch (ipfw) { case IP_FW_PASS: break; case IP_FW_DENY: ret = PFIL_DROPPED; break; case IP_FW_DUMMYNET: if (ip_dn_io_ptr == NULL) { ret = PFIL_DROPPED; break; } if (mem) { if (pfil_realloc(&p, flags, ifp) != 0) { ret = PFIL_DROPPED; break; } mem = false; realloc = true; } MPASS(args.flags & IPFW_ARGS_REF); ip_dn_io_ptr(p.m, &args); return (PFIL_CONSUMED); case IP_FW_NGTEE: case IP_FW_NETGRAPH: if (ng_ipfw_input_p == NULL) { ret = PFIL_DROPPED; break; } if (mem) { if (pfil_realloc(&p, flags, ifp) != 0) { ret = PFIL_DROPPED; break; } mem = false; realloc = true; } MPASS(args.flags & IPFW_ARGS_REF); (void )ng_ipfw_input_p(p.m, &args, ipfw == IP_FW_NGTEE); if (ipfw == IP_FW_NGTEE) /* ignore errors for NGTEE */ goto again; /* continue with packet */ ret = PFIL_CONSUMED; break; default: KASSERT(0, ("%s: unknown retval", __func__)); } if (!mem && ret != PFIL_PASS) { if (*p.m) FREE_PKT(*p.m); *p.m = NULL; } if (realloc && ret == PFIL_PASS) ret = PFIL_REALLOCED; return (ret); } /* do the divert, return 1 on error 0 on success */ static int ipfw_divert(struct mbuf **m0, struct ip_fw_args *args, bool tee) { /* * ipfw_chk() has already tagged the packet with the divert tag. * If tee is set, copy packet and return original. * If not tee, consume packet and send it to divert socket. */ struct mbuf *clone; struct ip *ip = mtod(*m0, struct ip *); struct m_tag *tag; /* Cloning needed for tee? */ if (tee == false) { clone = *m0; /* use the original mbuf */ *m0 = NULL; } else { clone = m_dup(*m0, M_NOWAIT); /* If we cannot duplicate the mbuf, we sacrifice the divert * chain and continue with the tee-ed packet. */ if (clone == NULL) return 1; } /* * Divert listeners can normally handle non-fragmented packets, * but we can only reass in the non-tee case. * This means that listeners on a tee rule may get fragments, * and have to live with that. * Note that we now have the 'reass' ipfw option so if we care * we can do it before a 'tee'. */ if (tee == false) switch (ip->ip_v) { case IPVERSION: if (ntohs(ip->ip_off) & (IP_MF | IP_OFFMASK)) { int hlen; struct mbuf *reass; reass = ip_reass(clone); /* Reassemble packet. */ if (reass == NULL) return 0; /* not an error */ /* if reass = NULL then it was consumed by ip_reass */ /* * IP header checksum fixup after reassembly and leave header * in network byte order. */ ip = mtod(reass, struct ip *); hlen = ip->ip_hl << 2; ip->ip_sum = 0; if (hlen == sizeof(struct ip)) ip->ip_sum = in_cksum_hdr(ip); else ip->ip_sum = in_cksum(reass, hlen); clone = reass; } break; #ifdef INET6 case IPV6_VERSION >> 4: { struct ip6_hdr *const ip6 = mtod(clone, struct ip6_hdr *); if (ip6->ip6_nxt == IPPROTO_FRAGMENT) { int nxt, off; off = sizeof(struct ip6_hdr); nxt = frag6_input(&clone, &off, 0); if (nxt == IPPROTO_DONE) return (0); } break; } #endif } /* attach a tag to the packet with the reinject info */ tag = m_tag_alloc(MTAG_IPFW_RULE, 0, sizeof(struct ipfw_rule_ref), M_NOWAIT); if (tag == NULL) { FREE_PKT(clone); return 1; } *((struct ipfw_rule_ref *)(tag+1)) = args->rule; m_tag_prepend(clone, tag); /* Do the dirty job... */ ip_divert_ptr(clone, args->flags & IPFW_ARGS_IN); return 0; } /* * attach or detach hooks for a given protocol family */ VNET_DEFINE_STATIC(pfil_hook_t, ipfw_inet_hook); #define V_ipfw_inet_hook VNET(ipfw_inet_hook) #ifdef INET6 VNET_DEFINE_STATIC(pfil_hook_t, ipfw_inet6_hook); #define V_ipfw_inet6_hook VNET(ipfw_inet6_hook) #endif VNET_DEFINE_STATIC(pfil_hook_t, ipfw_link_hook); #define V_ipfw_link_hook VNET(ipfw_link_hook) static void ipfw_hook(int pf) { struct pfil_hook_args pha; pfil_hook_t *h; pha.pa_version = PFIL_VERSION; pha.pa_flags = PFIL_IN | PFIL_OUT; pha.pa_modname = "ipfw"; pha.pa_ruleset = NULL; switch (pf) { case AF_INET: pha.pa_func = ipfw_check_packet; pha.pa_type = PFIL_TYPE_IP4; pha.pa_rulname = "default"; h = &V_ipfw_inet_hook; break; #ifdef INET6 case AF_INET6: pha.pa_func = ipfw_check_packet; pha.pa_type = PFIL_TYPE_IP6; pha.pa_rulname = "default6"; h = &V_ipfw_inet6_hook; break; #endif case AF_LINK: pha.pa_func = ipfw_check_frame; pha.pa_type = PFIL_TYPE_ETHERNET; pha.pa_rulname = "default-link"; pha.pa_flags |= PFIL_MEMPTR; h = &V_ipfw_link_hook; break; } *h = pfil_add_hook(&pha); } static void ipfw_unhook(int pf) { switch (pf) { case AF_INET: pfil_remove_hook(V_ipfw_inet_hook); break; #ifdef INET6 case AF_INET6: pfil_remove_hook(V_ipfw_inet6_hook); break; #endif case AF_LINK: pfil_remove_hook(V_ipfw_link_hook); break; } } static int ipfw_link(int pf, bool unlink) { struct pfil_link_args pla; pla.pa_version = PFIL_VERSION; pla.pa_flags = PFIL_IN | PFIL_OUT | PFIL_HEADPTR | PFIL_HOOKPTR; if (unlink) pla.pa_flags |= PFIL_UNLINK; switch (pf) { case AF_INET: pla.pa_head = V_inet_pfil_head; pla.pa_hook = V_ipfw_inet_hook; break; #ifdef INET6 case AF_INET6: pla.pa_head = V_inet6_pfil_head; pla.pa_hook = V_ipfw_inet6_hook; break; #endif case AF_LINK: pla.pa_head = V_link_pfil_head; pla.pa_hook = V_ipfw_link_hook; break; } return (pfil_link(&pla)); } int ipfw_attach_hooks(void) { int error = 0; ipfw_hook(AF_INET); TUNABLE_INT_FETCH("net.inet.ip.fw.enable", &V_fw_enable); if (V_fw_enable && (error = ipfw_link(AF_INET, false)) != 0) printf("ipfw_hook() error\n"); #ifdef INET6 ipfw_hook(AF_INET6); TUNABLE_INT_FETCH("net.inet6.ip6.fw.enable", &V_fw6_enable); if (V_fw6_enable && (error = ipfw_link(AF_INET6, false)) != 0) printf("ipfw6_hook() error\n"); #endif ipfw_hook(AF_LINK); TUNABLE_INT_FETCH("net.link.ether.ipfw", &V_fwlink_enable); if (V_fwlink_enable && (error = ipfw_link(AF_LINK, false)) != 0) printf("ipfw_link_hook() error\n"); return (error); } void ipfw_detach_hooks(void) { ipfw_unhook(AF_INET); #ifdef INET6 ipfw_unhook(AF_INET6); #endif ipfw_unhook(AF_LINK); } int ipfw_chg_hook(SYSCTL_HANDLER_ARGS) { int newval; int error; int af; if (arg1 == &V_fw_enable) af = AF_INET; #ifdef INET6 else if (arg1 == &V_fw6_enable) af = AF_INET6; #endif else if (arg1 == &V_fwlink_enable) af = AF_LINK; else return (EINVAL); newval = *(int *)arg1; /* Handle sysctl change */ error = sysctl_handle_int(oidp, &newval, 0, req); if (error) return (error); /* Formalize new value */ newval = (newval) ? 1 : 0; if (*(int *)arg1 == newval) return (0); error = ipfw_link(af, newval == 0 ? true : false); if (error) return (error); *(int *)arg1 = newval; return (0); } /* end of file */