/* * Copyright (c) 2000-2012 Apple Inc. All rights reserved. * * @APPLE_OSREFERENCE_LICENSE_HEADER_START@ * * This file contains Original Code and/or Modifications of Original Code * as defined in and that are subject to the Apple Public Source License * Version 2.0 (the 'License'). You may not use this file except in * compliance with the License. The rights granted to you under the License * may not be used to create, or enable the creation or redistribution of, * unlawful or unlicensed copies of an Apple operating system, or to * circumvent, violate, or enable the circumvention or violation of, any * terms of an Apple operating system software license agreement. * * Please obtain a copy of the License at * http://www.opensource.apple.com/apsl/ and read it before using this file. * * The Original Code and all software distributed under the License are * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES, * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY, * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT. * Please see the License for the specific language governing rights and * limitations under the License. * * @APPLE_OSREFERENCE_LICENSE_HEADER_END@ */ /* * Copyright (c) 1982, 1986, 1988, 1990, 1993 * The Regents of the University of California. 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. * 3. All advertising materials mentioning features or use of this software * must display the following acknowledgement: * This product includes software developed by the University of * California, Berkeley and its contributors. * 4. Neither the name of the University nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 REGENTS 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. * * @(#)ip_output.c 8.3 (Berkeley) 1/21/94 * $FreeBSD: src/sys/netinet/ip_output.c,v 1.99.2.16 2001/07/19 06:37:26 kris Exp $ */ /* * NOTICE: This file was modified by SPARTA, Inc. in 2005 to introduce * support for mandatory and extensible security protections. This notice * is included in support of clause 2.2 (b) of the Apple Public License, * Version 2.0. */ #define _IP_VHL #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #if CONFIG_MACF_NET #include #endif #include #include #include #define DBG_LAYER_BEG NETDBG_CODE(DBG_NETIP, 1) #define DBG_LAYER_END NETDBG_CODE(DBG_NETIP, 3) #define DBG_FNC_IP_OUTPUT NETDBG_CODE(DBG_NETIP, (1 << 8) | 1) #define DBG_FNC_IPSEC4_OUTPUT NETDBG_CODE(DBG_NETIP, (2 << 8) | 1) #define SWAP16(v) ((((v) & 0xff) << 8) | ((v) >> 8)) #if IPSEC #include #include #if IPSEC_DEBUG #include #else #define KEYDEBUG(lev,arg) #endif #endif /*IPSEC*/ #include #include #include #if DUMMYNET #include #endif #if PF #include #endif /* PF */ #if IPFIREWALL_FORWARD_DEBUG #define print_ip(a) printf("%ld.%ld.%ld.%ld",(ntohl(a.s_addr)>>24)&0xFF,\ (ntohl(a.s_addr)>>16)&0xFF,\ (ntohl(a.s_addr)>>8)&0xFF,\ (ntohl(a.s_addr))&0xFF); #endif u_short ip_id; static struct mbuf *ip_insertoptions(struct mbuf *, struct mbuf *, int *); static void ip_mloopback(struct ifnet *, struct mbuf *, struct sockaddr_in *, int); static int ip_pcbopts(int, struct mbuf **, struct mbuf *); static void imo_trace(struct ip_moptions *, int); static void ip_out_cksum_stats(int, u_int32_t); static struct ifaddr *in_selectsrcif(struct ip *, struct route *, unsigned int); int ip_optcopy(struct ip *, struct ip *); void in_delayed_cksum_offset(struct mbuf *, int ); void in_cksum_offset(struct mbuf* , size_t ); extern struct protosw inetsw[]; extern struct ip_linklocal_stat ip_linklocal_stat; extern lck_mtx_t *ip_mutex; /* temporary: for testing */ #if IPSEC extern int ipsec_bypass; #endif static int ip_maxchainsent = 0; SYSCTL_INT(_net_inet_ip, OID_AUTO, maxchainsent, CTLFLAG_RW | CTLFLAG_LOCKED, &ip_maxchainsent, 0, "use dlil_output_list"); #if DEBUG static int forge_ce = 0; SYSCTL_INT(_net_inet_ip, OID_AUTO, forge_ce, CTLFLAG_RW | CTLFLAG_LOCKED, &forge_ce, 0, "Forge ECN CE"); #endif /* DEBUG */ static int ip_select_srcif_debug = 0; SYSCTL_INT(_net_inet_ip, OID_AUTO, select_srcif_debug, CTLFLAG_RW | CTLFLAG_LOCKED, &ip_select_srcif_debug, 0, "log source interface selection debug info"); #define IMO_TRACE_HIST_SIZE 32 /* size of trace history */ /* For gdb */ __private_extern__ unsigned int imo_trace_hist_size = IMO_TRACE_HIST_SIZE; struct ip_moptions_dbg { struct ip_moptions imo; /* ip_moptions */ u_int16_t imo_refhold_cnt; /* # of IMO_ADDREF */ u_int16_t imo_refrele_cnt; /* # of IMO_REMREF */ /* * Alloc and free callers. */ ctrace_t imo_alloc; ctrace_t imo_free; /* * Circular lists of IMO_ADDREF and IMO_REMREF callers. */ ctrace_t imo_refhold[IMO_TRACE_HIST_SIZE]; ctrace_t imo_refrele[IMO_TRACE_HIST_SIZE]; }; #if DEBUG static unsigned int imo_debug = 1; /* debugging (enabled) */ #else static unsigned int imo_debug; /* debugging (disabled) */ #endif /* !DEBUG */ static unsigned int imo_size; /* size of zone element */ static struct zone *imo_zone; /* zone for ip_moptions */ #define IMO_ZONE_MAX 64 /* maximum elements in zone */ #define IMO_ZONE_NAME "ip_moptions" /* zone name */ /* * IP output. The packet in mbuf chain m contains a skeletal IP * header (with len, off, ttl, proto, tos, src, dst). * The mbuf chain containing the packet will be freed. * The mbuf opt, if present, will not be freed. */ int ip_output( struct mbuf *m0, struct mbuf *opt, struct route *ro, int flags, struct ip_moptions *imo, struct ip_out_args *ipoa) { int error; error = ip_output_list(m0, 0, opt, ro, flags, imo, ipoa); return error; } /* * Returns: 0 Success * ENOMEM * EADDRNOTAVAIL * ENETUNREACH * EHOSTUNREACH * EACCES * EMSGSIZE * ENOBUFS * ipsec4_getpolicybyaddr:??? [IPSEC 4th argument, contents modified] * ipsec4_getpolicybysock:??? [IPSEC 4th argument, contents modified] * key_spdacquire:??? [IPSEC] * ipsec4_output:??? [IPSEC] * ip_dn_io_ptr:??? [dummynet] * dlil_output:??? [DLIL] * dlil_output_list:??? [DLIL] * * Notes: The ipsec4_getpolicyby{addr|sock} function error returns are * only used as the error return from this function where one of * these functions fails to return a policy. */ int ip_output_list( struct mbuf *m0, int packetchain, struct mbuf *opt, struct route *ro, int flags, struct ip_moptions *imo, struct ip_out_args *ipoa) { struct ip *ip; struct ifnet *ifp = NULL; struct mbuf *m = m0, *prevnxt = NULL, **mppn = &prevnxt; int hlen = sizeof (struct ip); int len = 0, error = 0; struct sockaddr_in *dst = NULL; struct in_ifaddr *ia = NULL, *src_ia = NULL; int isbroadcast, sw_csum; struct in_addr pkt_dst; struct ipf_pktopts *ippo = NULL, ipf_pktopts; #if IPSEC struct ipsec_output_state ipsec_state; struct route *ipsec_saved_route = NULL; struct socket *so = NULL; struct secpolicy *sp = NULL; #endif #if IPFIREWALL_FORWARD int fwd_rewrite_src = 0; #endif #if IPFIREWALL int off; struct sockaddr_in *next_hop_from_ipfwd_tag = NULL; #endif #if IPFIREWALL || DUMMYNET struct ip_fw_args args; struct m_tag *tag; #endif int didfilter = 0; ipfilter_t inject_filter_ref = 0; #if DUMMYNET struct route saved_route; struct ip_out_args saved_ipoa; struct sockaddr_in dst_buf; #endif /* DUMMYNET */ struct mbuf * packetlist; int pktcnt = 0, tso = 0; u_int32_t bytecnt = 0; unsigned int ifscope = IFSCOPE_NONE; unsigned int nocell = 0; boolean_t select_srcif, srcbound; struct flowadv *adv = NULL; KERNEL_DEBUG(DBG_FNC_IP_OUTPUT | DBG_FUNC_START, 0,0,0,0,0); #if IPSEC bzero(&ipsec_state, sizeof(ipsec_state)); #endif /* IPSEC */ packetlist = m0; #if IPFIREWALL || DUMMYNET bzero(&args, sizeof(struct ip_fw_args)); if (SLIST_EMPTY(&m0->m_pkthdr.tags)) goto ipfw_tags_done; /* Grab info from mtags prepended to the chain */ #if DUMMYNET if ((tag = m_tag_locate(m0, KERNEL_MODULE_TAG_ID, KERNEL_TAG_TYPE_DUMMYNET, NULL)) != NULL) { struct dn_pkt_tag *dn_tag; dn_tag = (struct dn_pkt_tag *)(tag+1); args.fwa_ipfw_rule = dn_tag->dn_ipfw_rule; args.fwa_pf_rule = dn_tag->dn_pf_rule; opt = NULL; saved_route = dn_tag->dn_ro; ro = &saved_route; imo = NULL; bcopy(&dn_tag->dn_dst, &dst_buf, sizeof(dst_buf)); dst = &dst_buf; ifp = dn_tag->dn_ifp; flags = dn_tag->dn_flags; if ((dn_tag->dn_flags & IP_OUTARGS)) { saved_ipoa = dn_tag->dn_ipoa; ipoa = &saved_ipoa; } m_tag_delete(m0, tag); } #endif /* DUMMYNET */ #if IPDIVERT if ((tag = m_tag_locate(m0, KERNEL_MODULE_TAG_ID, KERNEL_TAG_TYPE_DIVERT, NULL)) != NULL) { struct divert_tag *div_tag; div_tag = (struct divert_tag *)(tag+1); args.fwa_divert_rule = div_tag->cookie; m_tag_delete(m0, tag); } #endif /* IPDIVERT */ #if IPFIREWALL if ((tag = m_tag_locate(m0, KERNEL_MODULE_TAG_ID, KERNEL_TAG_TYPE_IPFORWARD, NULL)) != NULL) { struct ip_fwd_tag *ipfwd_tag; ipfwd_tag = (struct ip_fwd_tag *)(tag+1); next_hop_from_ipfwd_tag = ipfwd_tag->next_hop; m_tag_delete(m0, tag); } #endif /* IPFIREWALL */ ipfw_tags_done: #endif /* IPFIREWALL || DUMMYNET */ m = m0; #if DIAGNOSTIC if ( !m || (m->m_flags & M_PKTHDR) != 0) panic("ip_output no HDR"); if (!ro) panic("ip_output no route, proto = %d", mtod(m, struct ip *)->ip_p); #endif bzero(&ipf_pktopts, sizeof(struct ipf_pktopts)); ippo = &ipf_pktopts; if (ip_doscopedroute && (flags & IP_OUTARGS)) { /* * In the forwarding case, only the ifscope value is used, * as source interface selection doesn't take place. */ if ((select_srcif = (!(flags & IP_FORWARDING) && (ipoa->ipoa_flags & IPOAF_SELECT_SRCIF)))) { ipf_pktopts.ippo_flags |= IPPOF_SELECT_SRCIF; } if ((ipoa->ipoa_flags & IPOAF_BOUND_IF) && ipoa->ipoa_boundif != IFSCOPE_NONE) { ifscope = ipoa->ipoa_boundif; ipf_pktopts.ippo_flags |= (IPPOF_BOUND_IF | (ifscope << IPPOF_SHIFT_IFSCOPE)); } if ((srcbound = (ipoa->ipoa_flags & IPOAF_BOUND_SRCADDR))) ipf_pktopts.ippo_flags |= IPPOF_BOUND_SRCADDR; } else { select_srcif = FALSE; srcbound = FALSE; ifscope = IFSCOPE_NONE; } if ((flags & IP_OUTARGS) && (ipoa->ipoa_flags & IPOAF_NO_CELLULAR)) { nocell = 1; ipf_pktopts.ippo_flags |= IPPOF_NO_IFT_CELLULAR; } if (flags & IP_OUTARGS) { adv = &ipoa->ipoa_flowadv; adv->code = FADV_SUCCESS; } #if DUMMYNET if (args.fwa_ipfw_rule != NULL || args.fwa_pf_rule != NULL) { /* dummynet already saw us */ ip = mtod(m, struct ip *); hlen = IP_VHL_HL(ip->ip_vhl) << 2; pkt_dst = ip->ip_dst; if (ro->ro_rt != NULL) { RT_LOCK_SPIN(ro->ro_rt); ia = (struct in_ifaddr *)ro->ro_rt->rt_ifa; if (ia) { /* Become a regular mutex */ RT_CONVERT_LOCK(ro->ro_rt); IFA_ADDREF(&ia->ia_ifa); } RT_UNLOCK(ro->ro_rt); } #if IPSEC if (ipsec_bypass == 0 && (flags & IP_NOIPSEC) == 0) { so = ipsec_getsocket(m); (void)ipsec_setsocket(m, NULL); } #endif /* IPSEC */ #if IPFIREWALL if (args.fwa_ipfw_rule != NULL) goto skip_ipsec; #endif /* #if IPFIREWALL */ if (args.fwa_pf_rule != NULL) goto sendit; } #endif /* DUMMYNET */ #if IPSEC if (ipsec_bypass == 0 && (flags & IP_NOIPSEC) == 0) { so = ipsec_getsocket(m); (void)ipsec_setsocket(m, NULL); } #endif loopit: /* * No need to proccess packet twice if we've * already seen it */ if (!SLIST_EMPTY(&m->m_pkthdr.tags)) inject_filter_ref = ipf_get_inject_filter(m); else inject_filter_ref = 0; if (opt) { m = ip_insertoptions(m, opt, &len); hlen = len; /* Update the chain */ if (m != m0) { if (m0 == packetlist) packetlist = m; m0 = m; } } ip = mtod(m, struct ip *); #if IPFIREWALL /* * rdar://8542331 * * When dealing with a packet chain, we need to reset "next_hop" because * "dst" may have been changed to the gateway address below for the previous * packet of the chain. This could cause the route to be inavertandly changed * to the route to the gateway address (instead of the route to the destination). */ args.fwa_next_hop = next_hop_from_ipfwd_tag; pkt_dst = args.fwa_next_hop ? args.fwa_next_hop->sin_addr : ip->ip_dst; #else pkt_dst = ip->ip_dst; #endif /* * We must not send if the packet is destined to network zero. * RFC1122 3.2.1.3 (a) and (b). */ if (IN_ZERONET(ntohl(pkt_dst.s_addr))) { error = EHOSTUNREACH; goto bad; } /* * Fill in IP header. */ if ((flags & (IP_FORWARDING|IP_RAWOUTPUT)) == 0) { ip->ip_vhl = IP_MAKE_VHL(IPVERSION, hlen >> 2); ip->ip_off &= IP_DF; #if RANDOM_IP_ID ip->ip_id = ip_randomid(); #else ip->ip_id = htons(ip_id++); #endif OSAddAtomic(1, &ipstat.ips_localout); } else { hlen = IP_VHL_HL(ip->ip_vhl) << 2; } #if DEBUG /* For debugging, we let the stack forge congestion */ if (forge_ce != 0 && ((ip->ip_tos & IPTOS_ECN_MASK) == IPTOS_ECN_ECT1 || (ip->ip_tos & IPTOS_ECN_MASK) == IPTOS_ECN_ECT0)) { ip->ip_tos = (ip->ip_tos & ~IPTOS_ECN_MASK) | IPTOS_ECN_CE; forge_ce--; } #endif /* DEBUG */ KERNEL_DEBUG(DBG_LAYER_BEG, ip->ip_dst.s_addr, ip->ip_src.s_addr, ip->ip_p, ip->ip_off, ip->ip_len); dst = (struct sockaddr_in *)(void *)&ro->ro_dst; /* * If there is a cached route, * check that it is to the same destination * and is still up. If not, free it and try again. * The address family should also be checked in case of sharing the * cache with IPv6. */ if (ro->ro_rt != NULL) { if (ro->ro_rt->generation_id != route_generation && ((flags & (IP_ROUTETOIF | IP_FORWARDING)) == 0) && (ip->ip_src.s_addr != INADDR_ANY)) { src_ia = ifa_foraddr(ip->ip_src.s_addr); if (src_ia == NULL) { error = EADDRNOTAVAIL; goto bad; } IFA_REMREF(&src_ia->ia_ifa); } /* * Test rt_flags without holding rt_lock for performance * reasons; if the route is down it will hopefully be * caught by the layer below (since it uses this route * as a hint) or during the next transmit. */ if ((ro->ro_rt->rt_flags & RTF_UP) == 0 || dst->sin_family != AF_INET || dst->sin_addr.s_addr != pkt_dst.s_addr) { rtfree(ro->ro_rt); ro->ro_rt = NULL; } /* * If we're doing source interface selection, we may not * want to use this route; only synch up the generation * count otherwise. */ if (!select_srcif && ro->ro_rt != NULL && ro->ro_rt->generation_id != route_generation) ro->ro_rt->generation_id = route_generation; } if (ro->ro_rt == NULL) { bzero(dst, sizeof(*dst)); dst->sin_family = AF_INET; dst->sin_len = sizeof(*dst); dst->sin_addr = pkt_dst; } /* * If routing to interface only, * short circuit routing lookup. */ if (flags & IP_ROUTETOIF) { if (ia) IFA_REMREF(&ia->ia_ifa); if ((ia = ifatoia(ifa_ifwithdstaddr(sintosa(dst)))) == 0) { if ((ia = ifatoia(ifa_ifwithnet(sintosa(dst)))) == 0) { OSAddAtomic(1, &ipstat.ips_noroute); error = ENETUNREACH; goto bad; } } ifp = ia->ia_ifp; ip->ip_ttl = 1; isbroadcast = in_broadcast(dst->sin_addr, ifp); } else if (IN_MULTICAST(ntohl(pkt_dst.s_addr)) && imo != NULL && (ifp = imo->imo_multicast_ifp) != NULL) { /* * Bypass the normal routing lookup for multicast * packets if the interface is specified. */ isbroadcast = 0; if (ia != NULL) IFA_REMREF(&ia->ia_ifa); /* Macro takes reference on ia */ IFP_TO_IA(ifp, ia); } else { boolean_t cloneok = FALSE; /* * Perform source interface selection; the source IP address * must belong to one of the addresses of the interface used * by the route. For performance reasons, do this only if * there is no route, or if the routing table has changed, * or if we haven't done source interface selection on this * route (for this PCB instance) before. */ if (select_srcif && ip->ip_src.s_addr != INADDR_ANY && (ro->ro_rt == NULL || !(ro->ro_rt->rt_flags & RTF_UP) || ro->ro_rt->generation_id != route_generation || !(ro->ro_flags & ROF_SRCIF_SELECTED))) { struct ifaddr *ifa; /* Find the source interface */ ifa = in_selectsrcif(ip, ro, ifscope); /* * If the source address belongs to a cellular interface * and the caller forbids our using interfaces of such * type, pretend that there is no source address. */ if (nocell && ifa != NULL && ifa->ifa_ifp->if_type == IFT_CELLULAR) { IFA_REMREF(ifa); error = EADDRNOTAVAIL; goto bad; } /* * If the source address is spoofed (in the case of * IP_RAWOUTPUT on an unbounded socket), or if this * is destined for local/loopback, just let it go out * using the interface of the route. Otherwise, * there's no interface having such an address, * so bail out. */ if (ifa == NULL && (!(flags & IP_RAWOUTPUT) || srcbound) && ifscope != lo_ifp->if_index) { error = EADDRNOTAVAIL; goto bad; } /* * If the caller didn't explicitly specify the scope, * pick it up from the source interface. If the cached * route was wrong and was blown away as part of source * interface selection, don't mask out RTF_PRCLONING * since that route may have been allocated by the ULP, * unless the IP header was created by the caller or * the destination is IPv4 LLA. The check for the * latter is needed because IPv4 LLAs are never scoped * in the current implementation, and we don't want to * replace the resolved IPv4 LLA route with one whose * gateway points to that of the default gateway on * the primary interface of the system. */ if (ifa != NULL) { if (ifscope == IFSCOPE_NONE) ifscope = ifa->ifa_ifp->if_index; IFA_REMREF(ifa); cloneok = (!(flags & IP_RAWOUTPUT) && !(IN_LINKLOCAL(ntohl(ip->ip_dst.s_addr)))); } } /* * If this is the case, we probably don't want to allocate * a protocol-cloned route since we didn't get one from the * ULP. This lets TCP do its thing, while not burdening * forwarding or ICMP with the overhead of cloning a route. * Of course, we still want to do any cloning requested by * the link layer, as this is probably required in all cases * for correct operation (as it is for ARP). */ if (ro->ro_rt == NULL) { unsigned long ign = RTF_PRCLONING; /* * We make an exception here: if the destination * address is INADDR_BROADCAST, allocate a protocol- * cloned host route so that we end up with a route * marked with the RTF_BROADCAST flag. Otherwise, * we would end up referring to the default route, * instead of creating a cloned host route entry. * That would introduce inconsistencies between ULPs * that allocate a route and those that don't. The * RTF_BROADCAST route is important since we'd want * to send out undirected IP broadcast packets using * link-level broadcast address. Another exception * is for ULP-created routes that got blown away by * source interface selection (see above). * * These exceptions will no longer be necessary when * the RTF_PRCLONING scheme is no longer present. */ if (cloneok || dst->sin_addr.s_addr == INADDR_BROADCAST) ign &= ~RTF_PRCLONING; /* * Loosen the route lookup criteria if the ifscope * corresponds to the loopback interface; this is * needed to support Application Layer Gateways * listening on loopback, in conjunction with packet * filter redirection rules. The final source IP * address will be rewritten by the packet filter * prior to the RFC1122 loopback check below. */ if (ifscope == lo_ifp->if_index) rtalloc_ign(ro, ign); else rtalloc_scoped_ign(ro, ign, ifscope); /* * If the route points to a cellular interface and the * caller forbids our using interfaces of such type, * pretend that there is no route. */ if (nocell && ro->ro_rt != NULL) { RT_LOCK_SPIN(ro->ro_rt); if (ro->ro_rt->rt_ifp->if_type == IFT_CELLULAR) { RT_UNLOCK(ro->ro_rt); rtfree(ro->ro_rt); ro->ro_rt = NULL; } else { RT_UNLOCK(ro->ro_rt); } } } if (ro->ro_rt == NULL) { OSAddAtomic(1, &ipstat.ips_noroute); error = EHOSTUNREACH; goto bad; } if (ia) IFA_REMREF(&ia->ia_ifa); RT_LOCK_SPIN(ro->ro_rt); ia = ifatoia(ro->ro_rt->rt_ifa); if (ia) { /* Become a regular mutex */ RT_CONVERT_LOCK(ro->ro_rt); IFA_ADDREF(&ia->ia_ifa); } ifp = ro->ro_rt->rt_ifp; ro->ro_rt->rt_use++; if (ro->ro_rt->rt_flags & RTF_GATEWAY) { dst = (struct sockaddr_in *)(void *) ro->ro_rt->rt_gateway; } if (ro->ro_rt->rt_flags & RTF_HOST) { isbroadcast = (ro->ro_rt->rt_flags & RTF_BROADCAST); } else { /* Become a regular mutex */ RT_CONVERT_LOCK(ro->ro_rt); isbroadcast = in_broadcast(dst->sin_addr, ifp); } RT_UNLOCK(ro->ro_rt); } if (IN_MULTICAST(ntohl(pkt_dst.s_addr))) { struct in_multi *inm; u_int32_t vif; u_int8_t ttl = IP_DEFAULT_MULTICAST_TTL; u_int8_t loop = IP_DEFAULT_MULTICAST_LOOP; m->m_flags |= M_MCAST; /* * IP destination address is multicast. Make sure "dst" * still points to the address in "ro". (It may have been * changed to point to a gateway address, above.) */ dst = (struct sockaddr_in *)(void *)&ro->ro_dst; /* * See if the caller provided any multicast options */ if (imo != NULL) { IMO_LOCK(imo); vif = imo->imo_multicast_vif; ttl = imo->imo_multicast_ttl; loop = imo->imo_multicast_loop; if ((flags & IP_RAWOUTPUT) == 0) ip->ip_ttl = ttl; if (imo->imo_multicast_ifp != NULL) ifp = imo->imo_multicast_ifp; IMO_UNLOCK(imo); #if MROUTING if (vif != -1 && ((flags & IP_RAWOUTPUT) == 0 || ip->ip_src.s_addr == INADDR_ANY)) ip->ip_src.s_addr = ip_mcast_src(vif); #endif /* MROUTING */ } else if ((flags & IP_RAWOUTPUT) == 0) { vif = -1; ip->ip_ttl = ttl; } /* * Confirm that the outgoing interface supports multicast. */ if (imo == NULL || vif == -1) { if ((ifp->if_flags & IFF_MULTICAST) == 0) { OSAddAtomic(1, &ipstat.ips_noroute); error = ENETUNREACH; goto bad; } } /* * If source address not specified yet, use address * of outgoing interface. */ if (ip->ip_src.s_addr == INADDR_ANY) { struct in_ifaddr *ia1; lck_rw_lock_shared(in_ifaddr_rwlock); TAILQ_FOREACH(ia1, &in_ifaddrhead, ia_link) { IFA_LOCK_SPIN(&ia1->ia_ifa); if (ia1->ia_ifp == ifp) { ip->ip_src = IA_SIN(ia1)->sin_addr; IFA_UNLOCK(&ia1->ia_ifa); break; } IFA_UNLOCK(&ia1->ia_ifa); } lck_rw_done(in_ifaddr_rwlock); if (ip->ip_src.s_addr == INADDR_ANY) { error = ENETUNREACH; goto bad; } } in_multihead_lock_shared(); IN_LOOKUP_MULTI(&pkt_dst, ifp, inm); in_multihead_lock_done(); if (inm != NULL && (imo == NULL || loop)) { /* * If we belong to the destination multicast group * on the outgoing interface, and the caller did not * forbid loopback, loop back a copy. */ if (!TAILQ_EMPTY(&ipv4_filters)) { struct ipfilter *filter; int seen = (inject_filter_ref == 0); if (imo != NULL) { ipf_pktopts.ippo_flags |= IPPOF_MCAST_OPTS; ipf_pktopts.ippo_mcast_ifnet = ifp; ipf_pktopts.ippo_mcast_ttl = ttl; ipf_pktopts.ippo_mcast_loop = loop; } ipf_ref(); /* 4135317 - always pass network byte order to filter */ #if BYTE_ORDER != BIG_ENDIAN HTONS(ip->ip_len); HTONS(ip->ip_off); #endif TAILQ_FOREACH(filter, &ipv4_filters, ipf_link) { if (seen == 0) { if ((struct ipfilter *)inject_filter_ref == filter) seen = 1; } else if (filter->ipf_filter.ipf_output) { errno_t result; result = filter->ipf_filter.ipf_output(filter->ipf_filter.cookie, (mbuf_t*)&m, ippo); if (result == EJUSTRETURN) { ipf_unref(); INM_REMREF(inm); goto done; } if (result != 0) { ipf_unref(); INM_REMREF(inm); goto bad; } } } /* set back to host byte order */ ip = mtod(m, struct ip *); #if BYTE_ORDER != BIG_ENDIAN NTOHS(ip->ip_len); NTOHS(ip->ip_off); #endif ipf_unref(); didfilter = 1; } ip_mloopback(ifp, m, dst, hlen); } #if MROUTING else { /* * If we are acting as a multicast router, perform * multicast forwarding as if the packet had just * arrived on the interface to which we are about * to send. The multicast forwarding function * recursively calls this function, using the * IP_FORWARDING flag to prevent infinite recursion. * * Multicasts that are looped back by ip_mloopback(), * above, will be forwarded by the ip_input() routine, * if necessary. */ if (ip_mrouter && (flags & IP_FORWARDING) == 0) { /* * Check if rsvp daemon is running. If not, don't * set ip_moptions. This ensures that the packet * is multicast and not just sent down one link * as prescribed by rsvpd. */ if (!rsvp_on) imo = NULL; if (ip_mforward(ip, ifp, m, imo) != 0) { m_freem(m); if (inm != NULL) INM_REMREF(inm); OSAddAtomic(1, &ipstat.ips_cantforward); goto done; } } } #endif /* MROUTING */ if (inm != NULL) INM_REMREF(inm); /* * Multicasts with a time-to-live of zero may be looped- * back, above, but must not be transmitted on a network. * Also, multicasts addressed to the loopback interface * are not sent -- the above call to ip_mloopback() will * loop back a copy if this host actually belongs to the * destination group on the loopback interface. */ if (ip->ip_ttl == 0 || ifp->if_flags & IFF_LOOPBACK) { m_freem(m); goto done; } goto sendit; } /* * If source address not specified yet, use address * of outgoing interface. */ if (ip->ip_src.s_addr == INADDR_ANY) { IFA_LOCK_SPIN(&ia->ia_ifa); ip->ip_src = IA_SIN(ia)->sin_addr; IFA_UNLOCK(&ia->ia_ifa); #if IPFIREWALL_FORWARD /* Keep note that we did this - if the firewall changes * the next-hop, our interface may change, changing the * default source IP. It's a shame so much effort happens * twice. Oh well. */ fwd_rewrite_src++; #endif /* IPFIREWALL_FORWARD */ } /* * Look for broadcast address and * and verify user is allowed to send * such a packet. */ if (isbroadcast) { if ((ifp->if_flags & IFF_BROADCAST) == 0) { error = EADDRNOTAVAIL; goto bad; } if ((flags & IP_ALLOWBROADCAST) == 0) { error = EACCES; goto bad; } /* don't allow broadcast messages to be fragmented */ if ((u_short)ip->ip_len > ifp->if_mtu) { error = EMSGSIZE; goto bad; } m->m_flags |= M_BCAST; } else { m->m_flags &= ~M_BCAST; } sendit: #if PF /* Invoke outbound packet filter */ if (PF_IS_ENABLED) { int rc; m0 = m; /* Save for later */ #if DUMMYNET args.fwa_m = m; args.fwa_next_hop = dst; args.fwa_oif = ifp; args.fwa_ro = ro; args.fwa_dst = dst; args.fwa_oflags = flags; if (flags & IP_OUTARGS) args.fwa_ipoa = ipoa; rc = pf_af_hook(ifp, mppn, &m, AF_INET, FALSE, &args); #else /* DUMMYNET */ rc = pf_af_hook(ifp, mppn, &m, AF_INET, FALSE, NULL); #endif /* DUMMYNET */ if (rc != 0 || m == NULL) { /* Move to the next packet */ m = *mppn; /* Skip ahead if first packet in list got dropped */ if (packetlist == m0) packetlist = m; if (m != NULL) { m0 = m; /* Next packet in the chain */ goto loopit; } else if (packetlist != NULL) { /* No more packet; send down the chain */ goto sendchain; } /* Nothing left; we're done */ goto done; } m0 = m; ip = mtod(m, struct ip *); pkt_dst = ip->ip_dst; hlen = IP_VHL_HL(ip->ip_vhl) << 2; } #endif /* PF */ /* * Force IP TTL to 255 following draft-ietf-zeroconf-ipv4-linklocal.txt */ if (IN_LINKLOCAL(ntohl(ip->ip_src.s_addr)) || IN_LINKLOCAL(ntohl(ip->ip_dst.s_addr))) { ip_linklocal_stat.iplls_out_total++; if (ip->ip_ttl != MAXTTL) { ip_linklocal_stat.iplls_out_badttl++; ip->ip_ttl = MAXTTL; } } if (!didfilter && !TAILQ_EMPTY(&ipv4_filters)) { struct ipfilter *filter; int seen = (inject_filter_ref == 0); ipf_pktopts.ippo_flags &= ~IPPOF_MCAST_OPTS; /* Check that a TSO frame isn't passed to a filter. * This could happen if a filter is inserted while * TCP is sending the TSO packet. */ if (m->m_pkthdr.csum_flags & CSUM_TSO_IPV4) { error = EMSGSIZE; goto bad; } ipf_ref(); /* 4135317 - always pass network byte order to filter */ #if BYTE_ORDER != BIG_ENDIAN HTONS(ip->ip_len); HTONS(ip->ip_off); #endif TAILQ_FOREACH(filter, &ipv4_filters, ipf_link) { if (seen == 0) { if ((struct ipfilter *)inject_filter_ref == filter) seen = 1; } else if (filter->ipf_filter.ipf_output) { errno_t result; result = filter->ipf_filter.ipf_output(filter->ipf_filter.cookie, (mbuf_t*)&m, ippo); if (result == EJUSTRETURN) { ipf_unref(); goto done; } if (result != 0) { ipf_unref(); goto bad; } } } /* set back to host byte order */ ip = mtod(m, struct ip *); #if BYTE_ORDER != BIG_ENDIAN NTOHS(ip->ip_len); NTOHS(ip->ip_off); #endif ipf_unref(); } #if IPSEC /* temporary for testing only: bypass ipsec alltogether */ if (ipsec_bypass != 0 || (flags & IP_NOIPSEC) != 0) goto skip_ipsec; KERNEL_DEBUG(DBG_FNC_IPSEC4_OUTPUT | DBG_FUNC_START, 0,0,0,0,0); /* get SP for this packet */ if (so == NULL) sp = ipsec4_getpolicybyaddr(m, IPSEC_DIR_OUTBOUND, flags, &error); else sp = ipsec4_getpolicybysock(m, IPSEC_DIR_OUTBOUND, so, &error); if (sp == NULL) { IPSEC_STAT_INCREMENT(ipsecstat.out_inval); KERNEL_DEBUG(DBG_FNC_IPSEC4_OUTPUT | DBG_FUNC_END, 0,0,0,0,0); goto bad; } error = 0; /* check policy */ switch (sp->policy) { case IPSEC_POLICY_DISCARD: case IPSEC_POLICY_GENERATE: /* * This packet is just discarded. */ IPSEC_STAT_INCREMENT(ipsecstat.out_polvio); KERNEL_DEBUG(DBG_FNC_IPSEC4_OUTPUT | DBG_FUNC_END, 1,0,0,0,0); goto bad; case IPSEC_POLICY_BYPASS: case IPSEC_POLICY_NONE: /* no need to do IPsec. */ KERNEL_DEBUG(DBG_FNC_IPSEC4_OUTPUT | DBG_FUNC_END, 2,0,0,0,0); goto skip_ipsec; case IPSEC_POLICY_IPSEC: if (sp->req == NULL) { /* acquire a policy */ error = key_spdacquire(sp); KERNEL_DEBUG(DBG_FNC_IPSEC4_OUTPUT | DBG_FUNC_END, 3,0,0,0,0); goto bad; } break; case IPSEC_POLICY_ENTRUST: default: printf("ip_output: Invalid policy found. %d\n", sp->policy); } { ipsec_state.m = m; if (flags & IP_ROUTETOIF) { bzero(&ipsec_state.ro, sizeof(ipsec_state.ro)); } else route_copyout(&ipsec_state.ro, ro, sizeof(ipsec_state.ro)); ipsec_state.dst = (struct sockaddr *)dst; ip->ip_sum = 0; /* * XXX * delayed checksums are not currently compatible with IPsec */ if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) { in_delayed_cksum(m); m->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA; } #if BYTE_ORDER != BIG_ENDIAN HTONS(ip->ip_len); HTONS(ip->ip_off); #endif DTRACE_IP6(send, struct mbuf *, m, struct inpcb *, NULL, struct ip *, ip, struct ifnet *, ifp, struct ip *, ip, struct ip6_hdr *, NULL); error = ipsec4_output(&ipsec_state, sp, flags); m0 = m = ipsec_state.m; if (flags & IP_ROUTETOIF) { /* * if we have tunnel mode SA, we may need to ignore * IP_ROUTETOIF. */ if (ipsec_state.tunneled) { flags &= ~IP_ROUTETOIF; ipsec_saved_route = ro; ro = &ipsec_state.ro; } } else { ipsec_saved_route = ro; ro = &ipsec_state.ro; } dst = (struct sockaddr_in *)(void *)ipsec_state.dst; if (error) { /* mbuf is already reclaimed in ipsec4_output. */ m0 = NULL; switch (error) { case EHOSTUNREACH: case ENETUNREACH: case EMSGSIZE: case ENOBUFS: case ENOMEM: break; default: printf("ip4_output (ipsec): error code %d\n", error); /*fall through*/ case ENOENT: /* don't show these error codes to the user */ error = 0; break; } KERNEL_DEBUG(DBG_FNC_IPSEC4_OUTPUT | DBG_FUNC_END, 4,0,0,0,0); goto bad; } } /* be sure to update variables that are affected by ipsec4_output() */ ip = mtod(m, struct ip *); #ifdef _IP_VHL hlen = IP_VHL_HL(ip->ip_vhl) << 2; #else hlen = ip->ip_hl << 2; #endif /* Check that there wasn't a route change and src is still valid */ if (ro->ro_rt != NULL && ro->ro_rt->generation_id != route_generation) { if ((src_ia = ifa_foraddr(ip->ip_src.s_addr)) == NULL && ((flags & (IP_ROUTETOIF | IP_FORWARDING)) == 0)) { error = EADDRNOTAVAIL; KERNEL_DEBUG(DBG_FNC_IPSEC4_OUTPUT | DBG_FUNC_END, 5,0,0,0,0); goto bad; } rtfree(ro->ro_rt); ro->ro_rt = NULL; if (src_ia != NULL) IFA_REMREF(&src_ia->ia_ifa); } if (ro->ro_rt == NULL) { if ((flags & IP_ROUTETOIF) == 0) { printf("ip_output: can't update route after " "IPsec processing\n"); error = EHOSTUNREACH; /*XXX*/ KERNEL_DEBUG(DBG_FNC_IPSEC4_OUTPUT | DBG_FUNC_END, 6,0,0,0,0); goto bad; } } else { if (ia) IFA_REMREF(&ia->ia_ifa); RT_LOCK_SPIN(ro->ro_rt); ia = ifatoia(ro->ro_rt->rt_ifa); if (ia) { /* Become a regular mutex */ RT_CONVERT_LOCK(ro->ro_rt); IFA_ADDREF(&ia->ia_ifa); } ifp = ro->ro_rt->rt_ifp; RT_UNLOCK(ro->ro_rt); } /* make it flipped, again. */ #if BYTE_ORDER != BIG_ENDIAN NTOHS(ip->ip_len); NTOHS(ip->ip_off); #endif KERNEL_DEBUG(DBG_FNC_IPSEC4_OUTPUT | DBG_FUNC_END, 7,0xff,0xff,0xff,0xff); /* Pass to filters again */ if (!TAILQ_EMPTY(&ipv4_filters)) { struct ipfilter *filter; ipf_pktopts.ippo_flags &= ~IPPOF_MCAST_OPTS; /* Check that a TSO frame isn't passed to a filter. * This could happen if a filter is inserted while * TCP is sending the TSO packet. */ if (m->m_pkthdr.csum_flags & CSUM_TSO_IPV4) { error = EMSGSIZE; goto bad; } ipf_ref(); /* 4135317 - always pass network byte order to filter */ #if BYTE_ORDER != BIG_ENDIAN HTONS(ip->ip_len); HTONS(ip->ip_off); #endif TAILQ_FOREACH(filter, &ipv4_filters, ipf_link) { if (filter->ipf_filter.ipf_output) { errno_t result; result = filter->ipf_filter.ipf_output(filter->ipf_filter.cookie, (mbuf_t*)&m, ippo); if (result == EJUSTRETURN) { ipf_unref(); goto done; } if (result != 0) { ipf_unref(); goto bad; } } } /* set back to host byte order */ ip = mtod(m, struct ip *); #if BYTE_ORDER != BIG_ENDIAN NTOHS(ip->ip_len); NTOHS(ip->ip_off); #endif ipf_unref(); } skip_ipsec: #endif /*IPSEC*/ #if IPFIREWALL /* * Check with the firewall... * but not if we are already being fwd'd from a firewall. */ if (fw_enable && IPFW_LOADED && !args.fwa_next_hop) { struct sockaddr_in *old = dst; args.fwa_m = m; args.fwa_next_hop = dst; args.fwa_oif = ifp; off = ip_fw_chk_ptr(&args); m = args.fwa_m; dst = args.fwa_next_hop; /* * On return we must do the following: * IP_FW_PORT_DENY_FLAG -> drop the pkt (XXX new) * 1<=off<= 0xffff -> DIVERT * (off & IP_FW_PORT_DYNT_FLAG) -> send to a DUMMYNET pipe * (off & IP_FW_PORT_TEE_FLAG) -> TEE the packet * dst != old -> IPFIREWALL_FORWARD * off==0, dst==old -> accept * If some of the above modules is not compiled in, then * we should't have to check the corresponding condition * (because the ipfw control socket should not accept * unsupported rules), but better play safe and drop * packets in case of doubt. */ m0 = m; if ( (off & IP_FW_PORT_DENY_FLAG) || m == NULL) { if (m) m_freem(m); error = EACCES ; goto done ; } ip = mtod(m, struct ip *); if (off == 0 && dst == old) {/* common case */ goto pass ; } #if DUMMYNET if (DUMMYNET_LOADED && (off & IP_FW_PORT_DYNT_FLAG) != 0) { /* * pass the pkt to dummynet. Need to include * pipe number, m, ifp, ro, dst because these are * not recomputed in the next pass. * All other parameters have been already used and * so they are not needed anymore. * XXX note: if the ifp or ro entry are deleted * while a pkt is in dummynet, we are in trouble! */ args.fwa_ro = ro; args.fwa_dst = dst; args.fwa_oflags = flags; if (flags & IP_OUTARGS) args.fwa_ipoa = ipoa; error = ip_dn_io_ptr(m, off & 0xffff, DN_TO_IP_OUT, &args, DN_CLIENT_IPFW); goto done; } #endif /* DUMMYNET */ #if IPDIVERT if (off != 0 && (off & IP_FW_PORT_DYNT_FLAG) == 0) { struct mbuf *clone = NULL; /* Clone packet if we're doing a 'tee' */ if ((off & IP_FW_PORT_TEE_FLAG) != 0) clone = m_dup(m, M_DONTWAIT); /* * XXX * delayed checksums are not currently compatible * with divert sockets. */ if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) { in_delayed_cksum(m); m->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA; } /* Restore packet header fields to original values */ #if BYTE_ORDER != BIG_ENDIAN HTONS(ip->ip_len); HTONS(ip->ip_off); #endif /* Deliver packet to divert input routine */ divert_packet(m, 0, off & 0xffff, args.fwa_divert_rule); /* If 'tee', continue with original packet */ if (clone != NULL) { m0 = m = clone; ip = mtod(m, struct ip *); goto pass; } goto done; } #endif #if IPFIREWALL_FORWARD /* Here we check dst to make sure it's directly reachable on the * interface we previously thought it was. * If it isn't (which may be likely in some situations) we have * to re-route it (ie, find a route for the next-hop and the * associated interface) and set them here. This is nested * forwarding which in most cases is undesirable, except where * such control is nigh impossible. So we do it here. * And I'm babbling. */ if (off == 0 && old != dst) { struct in_ifaddr *ia_fw; /* It's changed... */ /* There must be a better way to do this next line... */ static struct route sro_fwd, *ro_fwd = &sro_fwd; #if IPFIREWALL_FORWARD_DEBUG printf("IPFIREWALL_FORWARD: New dst ip: "); print_ip(dst->sin_addr); printf("\n"); #endif /* * We need to figure out if we have been forwarded * to a local socket. If so then we should somehow * "loop back" to ip_input, and get directed to the * PCB as if we had received this packet. This is * because it may be dificult to identify the packets * you want to forward until they are being output * and have selected an interface. (e.g. locally * initiated packets) If we used the loopback inteface, * we would not be able to control what happens * as the packet runs through ip_input() as * it is done through a ISR. */ lck_rw_lock_shared(in_ifaddr_rwlock); TAILQ_FOREACH(ia_fw, &in_ifaddrhead, ia_link) { /* * If the addr to forward to is one * of ours, we pretend to * be the destination for this packet. */ IFA_LOCK_SPIN(&ia_fw->ia_ifa); if (IA_SIN(ia_fw)->sin_addr.s_addr == dst->sin_addr.s_addr) { IFA_UNLOCK(&ia_fw->ia_ifa); break; } IFA_UNLOCK(&ia_fw->ia_ifa); } lck_rw_done(in_ifaddr_rwlock); if (ia_fw) { /* tell ip_input "dont filter" */ struct m_tag *fwd_tag; struct ip_fwd_tag *ipfwd_tag; fwd_tag = m_tag_create(KERNEL_MODULE_TAG_ID, KERNEL_TAG_TYPE_IPFORWARD, sizeof (*ipfwd_tag), M_NOWAIT, m); if (fwd_tag == NULL) { error = ENOBUFS; goto bad; } ipfwd_tag = (struct ip_fwd_tag *)(fwd_tag+1); ipfwd_tag->next_hop = args.fwa_next_hop; m_tag_prepend(m, fwd_tag); if (m->m_pkthdr.rcvif == NULL) m->m_pkthdr.rcvif = lo_ifp; if ((~IF_HWASSIST_CSUM_FLAGS(m->m_pkthdr.rcvif->if_hwassist) & m->m_pkthdr.csum_flags) == 0) { if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) { m->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA; m->m_pkthdr.csum_flags |= CSUM_DATA_VALID | CSUM_PSEUDO_HDR; m->m_pkthdr.csum_data = 0xffff; } m->m_pkthdr.csum_flags |= CSUM_IP_CHECKED | CSUM_IP_VALID; } else if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) { in_delayed_cksum(m); m->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA; ip->ip_sum = in_cksum(m, hlen); } #if BYTE_ORDER != BIG_ENDIAN HTONS(ip->ip_len); HTONS(ip->ip_off); #endif /* we need to call dlil_output to run filters * and resync to avoid recursion loops. */ if (lo_ifp) { dlil_output(lo_ifp, PF_INET, m, 0, (struct sockaddr *)dst, 0, adv); } else { printf("ip_output: no loopback ifp for forwarding!!!\n"); } goto done; } /* Some of the logic for this was * nicked from above. * * This rewrites the cached route in a local PCB. * Is this what we want to do? */ bcopy(dst, &ro_fwd->ro_dst, sizeof(*dst)); ro_fwd->ro_rt = NULL; rtalloc_ign(ro_fwd, RTF_PRCLONING); if (ro_fwd->ro_rt == NULL) { OSAddAtomic(1, &ipstat.ips_noroute); error = EHOSTUNREACH; goto bad; } RT_LOCK_SPIN(ro_fwd->ro_rt); ia_fw = ifatoia(ro_fwd->ro_rt->rt_ifa); if (ia_fw != NULL) { /* Become a regular mutex */ RT_CONVERT_LOCK(ro_fwd->ro_rt); IFA_ADDREF(&ia_fw->ia_ifa); } ifp = ro_fwd->ro_rt->rt_ifp; ro_fwd->ro_rt->rt_use++; if (ro_fwd->ro_rt->rt_flags & RTF_GATEWAY) dst = (struct sockaddr_in *)(void *)ro_fwd->ro_rt->rt_gateway; if (ro_fwd->ro_rt->rt_flags & RTF_HOST) { isbroadcast = (ro_fwd->ro_rt->rt_flags & RTF_BROADCAST); } else { /* Become a regular mutex */ RT_CONVERT_LOCK(ro_fwd->ro_rt); isbroadcast = in_broadcast(dst->sin_addr, ifp); } RT_UNLOCK(ro_fwd->ro_rt); rtfree(ro->ro_rt); ro->ro_rt = ro_fwd->ro_rt; dst = (struct sockaddr_in *)(void *)&ro_fwd->ro_dst; /* * If we added a default src ip earlier, * which would have been gotten from the-then * interface, do it again, from the new one. */ if (ia_fw != NULL) { if (fwd_rewrite_src) { IFA_LOCK_SPIN(&ia_fw->ia_ifa); ip->ip_src = IA_SIN(ia_fw)->sin_addr; IFA_UNLOCK(&ia_fw->ia_ifa); } IFA_REMREF(&ia_fw->ia_ifa); } goto pass ; } #endif /* IPFIREWALL_FORWARD */ /* * if we get here, none of the above matches, and * we have to drop the pkt */ m_freem(m); error = EACCES; /* not sure this is the right error msg */ goto done; } pass: #endif /* IPFIREWALL */ #if __APPLE__ /* Do not allow loopback address to wind up on a wire */ if ((ifp->if_flags & IFF_LOOPBACK) == 0 && ((ntohl(ip->ip_src.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET || (ntohl(ip->ip_dst.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET)) { OSAddAtomic(1, &ipstat.ips_badaddr); m_freem(m); /* * Do not simply drop the packet just like a firewall -- we want the * the application to feel the pain. * Return ENETUNREACH like ip6_output does in some similar cases. * This can startle the otherwise clueless process that specifies * loopback as the source address. */ error = ENETUNREACH; goto done; } #endif m->m_pkthdr.csum_flags |= CSUM_IP; tso = (ifp->if_hwassist & IFNET_TSO_IPV4) && (m->m_pkthdr.csum_flags & CSUM_TSO_IPV4); sw_csum = m->m_pkthdr.csum_flags & ~IF_HWASSIST_CSUM_FLAGS(ifp->if_hwassist); if ((ifp->if_hwassist & CSUM_TCP_SUM16) != 0) { /* * Special case code for GMACE * frames that can be checksumed by GMACE SUM16 HW: * frame >64, no fragments, no UDP */ if (apple_hwcksum_tx && (m->m_pkthdr.csum_flags & CSUM_TCP) && (ip->ip_len > 50) && (ip->ip_len <= ifp->if_mtu)) { /* Apple GMAC HW, expects STUFF_OFFSET << 16 | START_OFFSET */ u_short offset = (IP_VHL_HL(ip->ip_vhl) << 2) +14 ; /* IP+Enet header length */ u_short csumprev= m->m_pkthdr.csum_data & 0xFFFF; m->m_pkthdr.csum_flags = CSUM_DATA_VALID | CSUM_TCP_SUM16; /* for GMAC */ m->m_pkthdr.csum_data = (csumprev + offset) << 16 ; m->m_pkthdr.csum_data += offset; sw_csum = CSUM_DELAY_IP; /* do IP hdr chksum in software */ } else { /* let the software handle any UDP or TCP checksums */ sw_csum |= (CSUM_DELAY_DATA & m->m_pkthdr.csum_flags); } } else if (apple_hwcksum_tx == 0) { sw_csum |= (CSUM_DELAY_DATA | CSUM_DELAY_IP) & m->m_pkthdr.csum_flags; } if (sw_csum & CSUM_DELAY_DATA) { in_delayed_cksum(m); sw_csum &= ~CSUM_DELAY_DATA; m->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA; } if (apple_hwcksum_tx != 0) { m->m_pkthdr.csum_flags &= IF_HWASSIST_CSUM_FLAGS(ifp->if_hwassist); } else { m->m_pkthdr.csum_flags = 0; } /* * If small enough for interface, or the interface will take * care of the fragmentation for us, can just send directly. */ if ((u_short)ip->ip_len <= ifp->if_mtu || tso || ifp->if_hwassist & CSUM_FRAGMENT) { if (tso) m->m_pkthdr.csum_flags |= CSUM_TSO_IPV4; #if BYTE_ORDER != BIG_ENDIAN HTONS(ip->ip_len); HTONS(ip->ip_off); #endif ip->ip_sum = 0; if (sw_csum & CSUM_DELAY_IP) { ip->ip_sum = in_cksum(m, hlen); } #ifndef __APPLE__ /* Record statistics for this interface address. */ if (!(flags & IP_FORWARDING) && ia != NULL) { ia->ia_ifa.if_opackets++; ia->ia_ifa.if_obytes += m->m_pkthdr.len; } #endif #if IPSEC /* clean ipsec history once it goes out of the node */ if (ipsec_bypass == 0 && (flags & IP_NOIPSEC) == 0) ipsec_delaux(m); #endif if (packetchain == 0) { if (ro->ro_rt && nstat_collect) nstat_route_tx(ro->ro_rt, 1, m->m_pkthdr.len, 0); error = dlil_output(ifp, PF_INET, m, ro->ro_rt, (struct sockaddr *)dst, 0, adv); goto done; } else { /* packet chaining allows us to reuse the route for all packets */ bytecnt += m->m_pkthdr.len; mppn = &m->m_nextpkt; m = m->m_nextpkt; if (m == NULL) { #if PF sendchain: #endif /* PF */ if (pktcnt > ip_maxchainsent) ip_maxchainsent = pktcnt; if (ro->ro_rt && nstat_collect) nstat_route_tx(ro->ro_rt, pktcnt, bytecnt, 0); //send error = dlil_output(ifp, PF_INET, packetlist, ro->ro_rt, (struct sockaddr *)dst, 0, adv); pktcnt = 0; bytecnt = 0; goto done; } m0 = m; pktcnt++; goto loopit; } } /* * Too large for interface; fragment if possible. * Must be able to put at least 8 bytes per fragment. */ if (ip->ip_off & IP_DF || (m->m_pkthdr.csum_flags & CSUM_TSO_IPV4) || pktcnt > 0) { error = EMSGSIZE; /* * This case can happen if the user changed the MTU * of an interface after enabling IP on it. Because * most netifs don't keep track of routes pointing to * them, there is no way for one to update all its * routes when the MTU is changed. */ if (ro->ro_rt) { RT_LOCK_SPIN(ro->ro_rt); if ((ro->ro_rt->rt_flags & (RTF_UP | RTF_HOST)) && !(ro->ro_rt->rt_rmx.rmx_locks & RTV_MTU) && (ro->ro_rt->rt_rmx.rmx_mtu > ifp->if_mtu)) { ro->ro_rt->rt_rmx.rmx_mtu = ifp->if_mtu; } RT_UNLOCK(ro->ro_rt); } if (pktcnt > 0) { m0 = packetlist; } OSAddAtomic(1, &ipstat.ips_cantfrag); goto bad; } error = ip_fragment(m, ifp, ifp->if_mtu, sw_csum); if (error != 0) { m0 = m = NULL; goto bad; } KERNEL_DEBUG(DBG_LAYER_END, ip->ip_dst.s_addr, ip->ip_src.s_addr, ip->ip_p, ip->ip_off, ip->ip_len); for (m = m0; m; m = m0) { m0 = m->m_nextpkt; m->m_nextpkt = 0; #if IPSEC /* clean ipsec history once it goes out of the node */ if (ipsec_bypass == 0 && (flags & IP_NOIPSEC) == 0) ipsec_delaux(m); #endif if (error == 0) { #ifndef __APPLE__ /* Record statistics for this interface address. */ if (ia != NULL) { ia->ia_ifa.if_opackets++; ia->ia_ifa.if_obytes += m->m_pkthdr.len; } #endif if ((packetchain != 0) && (pktcnt > 0)) panic("ip_output: mix of packet in packetlist is wrong=%p", packetlist); if (ro->ro_rt && nstat_collect) nstat_route_tx(ro->ro_rt, 1, m->m_pkthdr.len, 0); error = dlil_output(ifp, PF_INET, m, ro->ro_rt, (struct sockaddr *)dst, 0, adv); } else m_freem(m); } if (error == 0) OSAddAtomic(1, &ipstat.ips_fragmented); done: if (ia) { IFA_REMREF(&ia->ia_ifa); ia = NULL; } #if IPSEC if (ipsec_bypass == 0 && (flags & IP_NOIPSEC) == 0) { if (ipsec_state.ro.ro_rt) rtfree(ipsec_state.ro.ro_rt); if (sp != NULL) { KEYDEBUG(KEYDEBUG_IPSEC_STAMP, printf("DP ip_output call free SP:%x\n", sp)); key_freesp(sp, KEY_SADB_UNLOCKED); } } #endif /* IPSEC */ KERNEL_DEBUG(DBG_FNC_IP_OUTPUT | DBG_FUNC_END, error,0,0,0,0); return (error); bad: m_freem(m0); goto done; } int ip_fragment(struct mbuf *m, struct ifnet *ifp, unsigned long mtu, int sw_csum) { struct ip *ip, *mhip; int len, hlen, mhlen, firstlen, off, error = 0; struct mbuf **mnext = &m->m_nextpkt, *m0; int nfrags = 1; ip = mtod(m, struct ip *); #ifdef _IP_VHL hlen = IP_VHL_HL(ip->ip_vhl) << 2; #else hlen = ip->ip_hl << 2; #endif firstlen = len = (mtu - hlen) &~ 7; if (len < 8) { m_freem(m); return (EMSGSIZE); } /* * if the interface will not calculate checksums on * fragmented packets, then do it here. */ if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA && (ifp->if_hwassist & CSUM_IP_FRAGS) == 0) { in_delayed_cksum(m); m->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA; } /* * Loop through length of segment after first fragment, * make new header and copy data of each part and link onto chain. */ m0 = m; mhlen = sizeof (struct ip); for (off = hlen + len; off < (u_short)ip->ip_len; off += len) { MGETHDR(m, M_DONTWAIT, MT_HEADER); /* MAC-OK */ if (m == 0) { error = ENOBUFS; OSAddAtomic(1, &ipstat.ips_odropped); goto sendorfree; } m->m_flags |= (m0->m_flags & M_MCAST) | M_FRAG; m->m_data += max_linkhdr; mhip = mtod(m, struct ip *); *mhip = *ip; if (hlen > sizeof (struct ip)) { mhlen = ip_optcopy(ip, mhip) + sizeof (struct ip); mhip->ip_vhl = IP_MAKE_VHL(IPVERSION, mhlen >> 2); } m->m_len = mhlen; mhip->ip_off = ((off - hlen) >> 3) + (ip->ip_off & ~IP_MF); if (ip->ip_off & IP_MF) mhip->ip_off |= IP_MF; if (off + len >= (u_short)ip->ip_len) len = (u_short)ip->ip_len - off; else mhip->ip_off |= IP_MF; mhip->ip_len = htons((u_short)(len + mhlen)); m->m_next = m_copy(m0, off, len); if (m->m_next == 0) { (void) m_free(m); error = ENOBUFS; /* ??? */ OSAddAtomic(1, &ipstat.ips_odropped); goto sendorfree; } m->m_pkthdr.len = mhlen + len; m->m_pkthdr.rcvif = 0; m->m_pkthdr.csum_flags = m0->m_pkthdr.csum_flags; m->m_pkthdr.socket_id = m0->m_pkthdr.socket_id; M_COPY_PFTAG(m, m0); m_set_service_class(m, m0->m_pkthdr.svc); #if CONFIG_MACF_NET mac_netinet_fragment(m0, m); #endif #if BYTE_ORDER != BIG_ENDIAN HTONS(mhip->ip_off); #endif mhip->ip_sum = 0; if (sw_csum & CSUM_DELAY_IP) { mhip->ip_sum = in_cksum(m, mhlen); } *mnext = m; mnext = &m->m_nextpkt; nfrags++; } OSAddAtomic(nfrags, &ipstat.ips_ofragments); /* set first/last markers for fragment chain */ m->m_flags |= M_LASTFRAG; m0->m_flags |= M_FIRSTFRAG | M_FRAG; m0->m_pkthdr.csum_data = nfrags; /* * Update first fragment by trimming what's been copied out * and updating header, then send each fragment (in order). */ m = m0; m_adj(m, hlen + firstlen - (u_short)ip->ip_len); m->m_pkthdr.len = hlen + firstlen; ip->ip_len = htons((u_short)m->m_pkthdr.len); ip->ip_off |= IP_MF; #if BYTE_ORDER != BIG_ENDIAN HTONS(ip->ip_off); #endif ip->ip_sum = 0; if (sw_csum & CSUM_DELAY_IP) { ip->ip_sum = in_cksum(m, hlen); } sendorfree: if (error) m_freem_list(m0); return (error); } static void ip_out_cksum_stats(int proto, u_int32_t len) { switch (proto) { case IPPROTO_TCP: tcp_out_cksum_stats(len); break; case IPPROTO_UDP: udp_out_cksum_stats(len); break; default: /* keep only TCP or UDP stats for now */ break; } } void in_delayed_cksum_offset(struct mbuf *m0, int ip_offset) { struct ip *ip; unsigned char buf[sizeof(struct ip)]; u_short csum, offset, ip_len; /* Save copy of first mbuf pointer and the ip_offset before modifying */ struct mbuf *m = m0; int ip_offset_copy = ip_offset; while (ip_offset >= m->m_len) { ip_offset -= m->m_len; m = m->m_next; if (m == NULL) { printf("in_delayed_cksum_withoffset failed - " "ip_offset wasn't in the packet\n"); return; } } /* * In case the IP header is not contiguous, or not 32-bit * aligned, copy it to a local buffer. */ if ((ip_offset + sizeof(struct ip) > m->m_len) || !IP_HDR_ALIGNED_P(mtod(m, caddr_t) + ip_offset)) { #if DEBUG printf("delayed m_pullup, m->len: %d off: %d\n", m->m_len, ip_offset); #endif m_copydata(m, ip_offset, sizeof(struct ip), (caddr_t) buf); ip = (struct ip *)(void *)buf; } else { ip = (struct ip*)(void *)(m->m_data + ip_offset); } /* Gross */ if (ip_offset) { m->m_len -= ip_offset; m->m_data += ip_offset; } offset = IP_VHL_HL(ip->ip_vhl) << 2 ; /* * We could be in the context of an IP or interface filter; in the * former case, ip_len would be in host (correct) order while for * the latter it would be in network order. Because of this, we * attempt to interpret the length field by comparing it against * the actual packet length. If the comparison fails, byte swap * the length and check again. If it still fails, then the packet * is bogus and we give up. */ ip_len = ip->ip_len; if (ip_len != (m0->m_pkthdr.len - ip_offset_copy)) { ip_len = SWAP16(ip_len); if (ip_len != (m0->m_pkthdr.len - ip_offset_copy)) { printf("in_delayed_cksum_offset: ip_len %d (%d) " "doesn't match actual length %d\n", ip->ip_len, ip_len, (m0->m_pkthdr.len - ip_offset_copy)); return; } } csum = in_cksum_skip(m, ip_len, offset); /* Update stats */ ip_out_cksum_stats(ip->ip_p, ip_len - offset); if (m0->m_pkthdr.csum_flags & CSUM_UDP && csum == 0) csum = 0xffff; offset += m0->m_pkthdr.csum_data & 0xFFFF; /* checksum offset */ /* Gross */ if (ip_offset) { if (M_LEADINGSPACE(m) < ip_offset) panic("in_delayed_cksum_offset - chain modified!\n"); m->m_len += ip_offset; m->m_data -= ip_offset; } if (offset > ip_len) /* bogus offset */ return; /* Insert the checksum in the existing chain */ if (offset + ip_offset + sizeof(u_short) > m->m_len) { char tmp[2]; #if DEBUG printf("delayed m_copyback, m->len: %d off: %d p: %d\n", m->m_len, offset + ip_offset, ip->ip_p); #endif *(u_short *)(void *)tmp = csum; m_copyback(m, offset + ip_offset, 2, tmp); } else if (IP_HDR_ALIGNED_P(mtod(m, caddr_t) + ip_offset)) { *(u_short *)(void *)(m->m_data + offset + ip_offset) = csum; } else { bcopy(&csum, (m->m_data + offset + ip_offset), sizeof (csum)); } } void in_delayed_cksum(struct mbuf *m) { in_delayed_cksum_offset(m, 0); } void in_cksum_offset(struct mbuf* m, size_t ip_offset) { struct ip* ip = NULL; int hlen = 0; unsigned char buf[sizeof(struct ip)]; int swapped = 0; /* Save copy of first mbuf pointer and the ip_offset before modifying */ struct mbuf* m0 = m; size_t ip_offset_copy = ip_offset; while (ip_offset >= m->m_len) { ip_offset -= m->m_len; m = m->m_next; if (m == NULL) { printf("in_cksum_offset failed - ip_offset wasn't " "in the packet\n"); return; } } /* * In case the IP header is not contiguous, or not 32-bit * aligned, copy it to a local buffer. */ if ((ip_offset + sizeof(struct ip) > m->m_len) || !IP_HDR_ALIGNED_P(mtod(m, caddr_t) + ip_offset)) { #if DEBUG printf("in_cksum_offset - delayed m_pullup, m->len: %d " "off: %lu\n", m->m_len, ip_offset); #endif m_copydata(m, ip_offset, sizeof(struct ip), (caddr_t) buf); ip = (struct ip *)(void *)buf; ip->ip_sum = 0; m_copyback(m, ip_offset + offsetof(struct ip, ip_sum), 2, (caddr_t)&ip->ip_sum); } else { ip = (struct ip*)(void *)(m->m_data + ip_offset); ip->ip_sum = 0; } /* Gross */ if (ip_offset) { m->m_len -= ip_offset; m->m_data += ip_offset; } #ifdef _IP_VHL hlen = IP_VHL_HL(ip->ip_vhl) << 2; #else hlen = ip->ip_hl << 2; #endif /* * We could be in the context of an IP or interface filter; in the * former case, ip_len would be in host order while for the latter * it would be in network (correct) order. Because of this, we * attempt to interpret the length field by comparing it against * the actual packet length. If the comparison fails, byte swap * the length and check again. If it still fails, then the packet * is bogus and we give up. */ if (ntohs(ip->ip_len) != (m0->m_pkthdr.len - ip_offset_copy)) { ip->ip_len = SWAP16(ip->ip_len); swapped = 1; if (ntohs(ip->ip_len) != (m0->m_pkthdr.len - ip_offset_copy)) { ip->ip_len = SWAP16(ip->ip_len); printf("in_cksum_offset: ip_len %d (%d) " "doesn't match actual length %lu\n", ip->ip_len, SWAP16(ip->ip_len), (m0->m_pkthdr.len - ip_offset_copy)); return; } } ip->ip_sum = 0; ip->ip_sum = in_cksum(m, hlen); if (swapped) ip->ip_len = SWAP16(ip->ip_len); /* Gross */ if (ip_offset) { if (M_LEADINGSPACE(m) < ip_offset) panic("in_cksum_offset - chain modified!\n"); m->m_len += ip_offset; m->m_data -= ip_offset; } /* * Insert the checksum in the existing chain if IP header not * contiguous, or if it's not 32-bit aligned, i.e. all the cases * where it was copied to a local buffer. */ if (ip_offset + sizeof(struct ip) > m->m_len) { char tmp[2]; #if DEBUG printf("in_cksum_offset m_copyback, m->len: %u off: %lu " "p: %d\n", m->m_len, ip_offset + offsetof(struct ip, ip_sum), ip->ip_p); #endif *(u_short *)(void *)tmp = ip->ip_sum; m_copyback(m, ip_offset + offsetof(struct ip, ip_sum), 2, tmp); } else if (!IP_HDR_ALIGNED_P(mtod(m, caddr_t) + ip_offset)) { bcopy(&ip->ip_sum, (m->m_data + ip_offset + offsetof(struct ip, ip_sum)), sizeof (u_short)); } } /* * Insert IP options into preformed packet. * Adjust IP destination as required for IP source routing, * as indicated by a non-zero in_addr at the start of the options. * * XXX This routine assumes that the packet has no options in place. */ static struct mbuf * ip_insertoptions(m, opt, phlen) register struct mbuf *m; struct mbuf *opt; int *phlen; { register struct ipoption *p = mtod(opt, struct ipoption *); struct mbuf *n; register struct ip *ip = mtod(m, struct ip *); unsigned optlen; optlen = opt->m_len - sizeof(p->ipopt_dst); if (optlen + (u_short)ip->ip_len > IP_MAXPACKET) return (m); /* XXX should fail */ if (p->ipopt_dst.s_addr) ip->ip_dst = p->ipopt_dst; if (m->m_flags & M_EXT || m->m_data - optlen < m->m_pktdat) { MGETHDR(n, M_DONTWAIT, MT_HEADER); /* MAC-OK */ if (n == 0) return (m); n->m_pkthdr.rcvif = 0; #if CONFIG_MACF_NET mac_mbuf_label_copy(m, n); #endif n->m_pkthdr.len = m->m_pkthdr.len + optlen; m->m_len -= sizeof(struct ip); m->m_data += sizeof(struct ip); n->m_next = m; m = n; m->m_len = optlen + sizeof(struct ip); m->m_data += max_linkhdr; (void)memcpy(mtod(m, void *), ip, sizeof(struct ip)); } else { m->m_data -= optlen; m->m_len += optlen; m->m_pkthdr.len += optlen; ovbcopy((caddr_t)ip, mtod(m, caddr_t), sizeof(struct ip)); } ip = mtod(m, struct ip *); bcopy(p->ipopt_list, ip + 1, optlen); *phlen = sizeof(struct ip) + optlen; ip->ip_vhl = IP_MAKE_VHL(IPVERSION, *phlen >> 2); ip->ip_len += optlen; return (m); } /* * Copy options from ip to jp, * omitting those not copied during fragmentation. */ int ip_optcopy(ip, jp) struct ip *ip, *jp; { register u_char *cp, *dp; int opt, optlen, cnt; cp = (u_char *)(ip + 1); dp = (u_char *)(jp + 1); cnt = (IP_VHL_HL(ip->ip_vhl) << 2) - sizeof (struct ip); for (; cnt > 0; cnt -= optlen, cp += optlen) { opt = cp[0]; if (opt == IPOPT_EOL) break; if (opt == IPOPT_NOP) { /* Preserve for IP mcast tunnel's LSRR alignment. */ *dp++ = IPOPT_NOP; optlen = 1; continue; } #if DIAGNOSTIC if (cnt < IPOPT_OLEN + sizeof(*cp)) panic("malformed IPv4 option passed to ip_optcopy"); #endif optlen = cp[IPOPT_OLEN]; #if DIAGNOSTIC if (optlen < IPOPT_OLEN + sizeof(*cp) || optlen > cnt) panic("malformed IPv4 option passed to ip_optcopy"); #endif /* bogus lengths should have been caught by ip_dooptions */ if (optlen > cnt) optlen = cnt; if (IPOPT_COPIED(opt)) { bcopy(cp, dp, optlen); dp += optlen; } } for (optlen = dp - (u_char *)(jp+1); optlen & 0x3; optlen++) *dp++ = IPOPT_EOL; return (optlen); } /* * IP socket option processing. */ int ip_ctloutput(so, sopt) struct socket *so; struct sockopt *sopt; { struct inpcb *inp = sotoinpcb(so); int error, optval; error = optval = 0; if (sopt->sopt_level != IPPROTO_IP) { return (EINVAL); } switch (sopt->sopt_dir) { case SOPT_SET: switch (sopt->sopt_name) { case IP_OPTIONS: #ifdef notyet case IP_RETOPTS: #endif { struct mbuf *m; if (sopt->sopt_valsize > MLEN) { error = EMSGSIZE; break; } MGET(m, sopt->sopt_p != kernproc ? M_WAIT : M_DONTWAIT, MT_HEADER); if (m == 0) { error = ENOBUFS; break; } m->m_len = sopt->sopt_valsize; error = sooptcopyin(sopt, mtod(m, char *), m->m_len, m->m_len); if (error) break; return (ip_pcbopts(sopt->sopt_name, &inp->inp_options, m)); } case IP_TOS: case IP_TTL: case IP_RECVOPTS: case IP_RECVRETOPTS: case IP_RECVDSTADDR: case IP_RECVIF: case IP_RECVTTL: case IP_RECVPKTINFO: error = sooptcopyin(sopt, &optval, sizeof optval, sizeof optval); if (error) break; switch (sopt->sopt_name) { case IP_TOS: inp->inp_ip_tos = optval; break; case IP_TTL: inp->inp_ip_ttl = optval; break; #define OPTSET(bit) \ if (optval) \ inp->inp_flags |= bit; \ else \ inp->inp_flags &= ~bit; case IP_RECVOPTS: OPTSET(INP_RECVOPTS); break; case IP_RECVRETOPTS: OPTSET(INP_RECVRETOPTS); break; case IP_RECVDSTADDR: OPTSET(INP_RECVDSTADDR); break; case IP_RECVIF: OPTSET(INP_RECVIF); break; case IP_RECVTTL: OPTSET(INP_RECVTTL); break; case IP_RECVPKTINFO: OPTSET(INP_PKTINFO); break; } break; #undef OPTSET #if CONFIG_FORCE_OUT_IFP /* * Apple private interface, similar to IP_BOUND_IF, except * that the parameter is a NULL-terminated string containing * the name of the network interface; an emptry string means * unbind. Applications are encouraged to use IP_BOUND_IF * instead, as that is the current "official" API. */ case IP_FORCE_OUT_IFP: { char ifname[IFNAMSIZ]; unsigned int ifscope; /* This option is settable only for IPv4 */ if (!(inp->inp_vflag & INP_IPV4)) { error = EINVAL; break; } /* Verify interface name parameter is sane */ if (sopt->sopt_valsize > sizeof(ifname)) { error = EINVAL; break; } /* Copy the interface name */ if (sopt->sopt_valsize != 0) { error = sooptcopyin(sopt, ifname, sizeof (ifname), sopt->sopt_valsize); if (error) break; } if (sopt->sopt_valsize == 0 || ifname[0] == '\0') { /* Unbind this socket from any interface */ ifscope = IFSCOPE_NONE; } else { ifnet_t ifp; /* Verify name is NULL terminated */ if (ifname[sopt->sopt_valsize - 1] != '\0') { error = EINVAL; break; } /* Bail out if given bogus interface name */ if (ifnet_find_by_name(ifname, &ifp) != 0) { error = ENXIO; break; } /* Bind this socket to this interface */ ifscope = ifp->if_index; /* * Won't actually free; since we don't release * this later, we should do it now. */ ifnet_release(ifp); } error = inp_bindif(inp, ifscope); } break; #endif /* * Multicast socket options are processed by the in_mcast * module. */ case IP_MULTICAST_IF: case IP_MULTICAST_IFINDEX: case IP_MULTICAST_VIF: case IP_MULTICAST_TTL: case IP_MULTICAST_LOOP: case IP_ADD_MEMBERSHIP: case IP_DROP_MEMBERSHIP: case IP_ADD_SOURCE_MEMBERSHIP: case IP_DROP_SOURCE_MEMBERSHIP: case IP_BLOCK_SOURCE: case IP_UNBLOCK_SOURCE: case IP_MSFILTER: case MCAST_JOIN_GROUP: case MCAST_LEAVE_GROUP: case MCAST_JOIN_SOURCE_GROUP: case MCAST_LEAVE_SOURCE_GROUP: case MCAST_BLOCK_SOURCE: case MCAST_UNBLOCK_SOURCE: error = inp_setmoptions(inp, sopt); break; case IP_PORTRANGE: error = sooptcopyin(sopt, &optval, sizeof optval, sizeof optval); if (error) break; switch (optval) { case IP_PORTRANGE_DEFAULT: inp->inp_flags &= ~(INP_LOWPORT); inp->inp_flags &= ~(INP_HIGHPORT); break; case IP_PORTRANGE_HIGH: inp->inp_flags &= ~(INP_LOWPORT); inp->inp_flags |= INP_HIGHPORT; break; case IP_PORTRANGE_LOW: inp->inp_flags &= ~(INP_HIGHPORT); inp->inp_flags |= INP_LOWPORT; break; default: error = EINVAL; break; } break; #if IPSEC case IP_IPSEC_POLICY: { caddr_t req = NULL; size_t len = 0; int priv; struct mbuf *m; int optname; if ((error = soopt_getm(sopt, &m)) != 0) /* XXX */ break; if ((error = soopt_mcopyin(sopt, m)) != 0) /* XXX */ break; priv = (proc_suser(sopt->sopt_p) == 0); if (m) { req = mtod(m, caddr_t); len = m->m_len; } optname = sopt->sopt_name; error = ipsec4_set_policy(inp, optname, req, len, priv); m_freem(m); break; } #endif /*IPSEC*/ #if TRAFFIC_MGT case IP_TRAFFIC_MGT_BACKGROUND: { unsigned background = 0; error = sooptcopyin(sopt, &background, sizeof(background), sizeof(background)); if (error) break; if (background) { socket_set_traffic_mgt_flags_locked(so, TRAFFIC_MGT_SO_BACKGROUND); } else { socket_clear_traffic_mgt_flags_locked(so, TRAFFIC_MGT_SO_BACKGROUND); } break; } #endif /* TRAFFIC_MGT */ /* * On a multihomed system, scoped routing can be used to * restrict the source interface used for sending packets. * The socket option IP_BOUND_IF binds a particular AF_INET * socket to an interface such that data sent on the socket * is restricted to that interface. This is unlike the * SO_DONTROUTE option where the routing table is bypassed; * therefore it allows for a greater flexibility and control * over the system behavior, and does not place any restriction * on the destination address type (e.g. unicast, multicast, * or broadcast if applicable) or whether or not the host is * directly reachable. Note that in the multicast transmit * case, IP_MULTICAST_{IF,IFINDEX} takes precedence over * IP_BOUND_IF, since the former practically bypasses the * routing table; in this case, IP_BOUND_IF sets the default * interface used for sending multicast packets in the absence * of an explicit multicast transmit interface. */ case IP_BOUND_IF: /* This option is settable only for IPv4 */ if (!(inp->inp_vflag & INP_IPV4)) { error = EINVAL; break; } error = sooptcopyin(sopt, &optval, sizeof (optval), sizeof (optval)); if (error) break; error = inp_bindif(inp, optval); break; case IP_NO_IFT_CELLULAR: /* This option is settable only for IPv4 */ if (!(inp->inp_vflag & INP_IPV4)) { error = EINVAL; break; } error = sooptcopyin(sopt, &optval, sizeof (optval), sizeof (optval)); if (error) break; error = inp_nocellular(inp, optval); break; case IP_OUT_IF: /* This option is not settable */ error = EINVAL; break; default: error = ENOPROTOOPT; break; } break; case SOPT_GET: switch (sopt->sopt_name) { case IP_OPTIONS: case IP_RETOPTS: if (inp->inp_options) error = sooptcopyout(sopt, mtod(inp->inp_options, char *), inp->inp_options->m_len); else sopt->sopt_valsize = 0; break; case IP_TOS: case IP_TTL: case IP_RECVOPTS: case IP_RECVRETOPTS: case IP_RECVDSTADDR: case IP_RECVIF: case IP_RECVTTL: case IP_PORTRANGE: case IP_RECVPKTINFO: switch (sopt->sopt_name) { case IP_TOS: optval = inp->inp_ip_tos; break; case IP_TTL: optval = inp->inp_ip_ttl; break; #define OPTBIT(bit) (inp->inp_flags & bit ? 1 : 0) case IP_RECVOPTS: optval = OPTBIT(INP_RECVOPTS); break; case IP_RECVRETOPTS: optval = OPTBIT(INP_RECVRETOPTS); break; case IP_RECVDSTADDR: optval = OPTBIT(INP_RECVDSTADDR); break; case IP_RECVIF: optval = OPTBIT(INP_RECVIF); break; case IP_RECVTTL: optval = OPTBIT(INP_RECVTTL); break; case IP_PORTRANGE: if (inp->inp_flags & INP_HIGHPORT) optval = IP_PORTRANGE_HIGH; else if (inp->inp_flags & INP_LOWPORT) optval = IP_PORTRANGE_LOW; else optval = 0; break; case IP_RECVPKTINFO: optval = OPTBIT(INP_PKTINFO); break; } error = sooptcopyout(sopt, &optval, sizeof optval); break; case IP_MULTICAST_IF: case IP_MULTICAST_IFINDEX: case IP_MULTICAST_VIF: case IP_MULTICAST_TTL: case IP_MULTICAST_LOOP: case IP_MSFILTER: error = inp_getmoptions(inp, sopt); break; #if IPSEC case IP_IPSEC_POLICY: { struct mbuf *m = NULL; caddr_t req = NULL; size_t len = 0; if (m != 0) { req = mtod(m, caddr_t); len = m->m_len; } error = ipsec4_get_policy(sotoinpcb(so), req, len, &m); if (error == 0) error = soopt_mcopyout(sopt, m); /* XXX */ if (error == 0) m_freem(m); break; } #endif /*IPSEC*/ #if TRAFFIC_MGT case IP_TRAFFIC_MGT_BACKGROUND: { unsigned background = (so->so_traffic_mgt_flags & TRAFFIC_MGT_SO_BACKGROUND); return (sooptcopyout(sopt, &background, sizeof(background))); break; } #endif /* TRAFFIC_MGT */ case IP_BOUND_IF: if (inp->inp_flags & INP_BOUND_IF) optval = inp->inp_boundifp->if_index; error = sooptcopyout(sopt, &optval, sizeof (optval)); break; case IP_NO_IFT_CELLULAR: optval = (inp->inp_flags & INP_NO_IFT_CELLULAR) ? 1 : 0; error = sooptcopyout(sopt, &optval, sizeof (optval)); break; case IP_OUT_IF: optval = (inp->inp_last_outifp != NULL) ? inp->inp_last_outifp->if_index : 0; error = sooptcopyout(sopt, &optval, sizeof (optval)); break; default: error = ENOPROTOOPT; break; } break; } return (error); } /* * Set up IP options in pcb for insertion in output packets. * Store in mbuf with pointer in pcbopt, adding pseudo-option * with destination address if source routed. */ static int ip_pcbopts( __unused int optname, struct mbuf **pcbopt, register struct mbuf *m) { register int cnt, optlen; register u_char *cp; u_char opt; /* turn off any old options */ if (*pcbopt) (void)m_free(*pcbopt); *pcbopt = 0; if (m == (struct mbuf *)0 || m->m_len == 0) { /* * Only turning off any previous options. */ if (m) (void)m_free(m); return (0); } #ifndef vax if (m->m_len % sizeof(int32_t)) goto bad; #endif /* * IP first-hop destination address will be stored before * actual options; move other options back * and clear it when none present. */ if (m->m_data + m->m_len + sizeof(struct in_addr) >= &m->m_dat[MLEN]) goto bad; cnt = m->m_len; m->m_len += sizeof(struct in_addr); cp = mtod(m, u_char *) + sizeof(struct in_addr); ovbcopy(mtod(m, caddr_t), (caddr_t)cp, (unsigned)cnt); bzero(mtod(m, caddr_t), sizeof(struct in_addr)); for (; cnt > 0; cnt -= optlen, cp += optlen) { opt = cp[IPOPT_OPTVAL]; if (opt == IPOPT_EOL) break; if (opt == IPOPT_NOP) optlen = 1; else { if (cnt < IPOPT_OLEN + sizeof(*cp)) goto bad; optlen = cp[IPOPT_OLEN]; if (optlen < IPOPT_OLEN + sizeof(*cp) || optlen > cnt) goto bad; } switch (opt) { default: break; case IPOPT_LSRR: case IPOPT_SSRR: /* * user process specifies route as: * ->A->B->C->D * D must be our final destination (but we can't * check that since we may not have connected yet). * A is first hop destination, which doesn't appear in * actual IP option, but is stored before the options. */ if (optlen < IPOPT_MINOFF - 1 + sizeof(struct in_addr)) goto bad; m->m_len -= sizeof(struct in_addr); cnt -= sizeof(struct in_addr); optlen -= sizeof(struct in_addr); cp[IPOPT_OLEN] = optlen; /* * Move first hop before start of options. */ bcopy((caddr_t)&cp[IPOPT_OFFSET+1], mtod(m, caddr_t), sizeof(struct in_addr)); /* * Then copy rest of options back * to close up the deleted entry. */ ovbcopy((caddr_t)(&cp[IPOPT_OFFSET+1] + sizeof(struct in_addr)), (caddr_t)&cp[IPOPT_OFFSET+1], (unsigned)cnt + sizeof(struct in_addr)); break; } } if (m->m_len > MAX_IPOPTLEN + sizeof(struct in_addr)) goto bad; *pcbopt = m; return (0); bad: (void)m_free(m); return (EINVAL); } void ip_moptions_init(void) { PE_parse_boot_argn("ifa_debug", &imo_debug, sizeof (imo_debug)); imo_size = (imo_debug == 0) ? sizeof (struct ip_moptions) : sizeof (struct ip_moptions_dbg); imo_zone = zinit(imo_size, IMO_ZONE_MAX * imo_size, 0, IMO_ZONE_NAME); if (imo_zone == NULL) { panic("%s: failed allocating %s", __func__, IMO_ZONE_NAME); /* NOTREACHED */ } zone_change(imo_zone, Z_EXPAND, TRUE); } void imo_addref(struct ip_moptions *imo, int locked) { if (!locked) IMO_LOCK(imo); else IMO_LOCK_ASSERT_HELD(imo); if (++imo->imo_refcnt == 0) { panic("%s: imo %p wraparound refcnt\n", __func__, imo); /* NOTREACHED */ } else if (imo->imo_trace != NULL) { (*imo->imo_trace)(imo, TRUE); } if (!locked) IMO_UNLOCK(imo); } void imo_remref(struct ip_moptions *imo) { int i; IMO_LOCK(imo); if (imo->imo_refcnt == 0) { panic("%s: imo %p negative refcnt", __func__, imo); /* NOTREACHED */ } else if (imo->imo_trace != NULL) { (*imo->imo_trace)(imo, FALSE); } --imo->imo_refcnt; if (imo->imo_refcnt > 0) { IMO_UNLOCK(imo); return; } for (i = 0; i < imo->imo_num_memberships; ++i) { struct in_mfilter *imf; imf = imo->imo_mfilters ? &imo->imo_mfilters[i] : NULL; if (imf != NULL) imf_leave(imf); (void) in_leavegroup(imo->imo_membership[i], imf); if (imf != NULL) imf_purge(imf); INM_REMREF(imo->imo_membership[i]); imo->imo_membership[i] = NULL; } imo->imo_num_memberships = 0; if (imo->imo_mfilters != NULL) { FREE(imo->imo_mfilters, M_INMFILTER); imo->imo_mfilters = NULL; } if (imo->imo_membership != NULL) { FREE(imo->imo_membership, M_IPMOPTS); imo->imo_membership = NULL; } IMO_UNLOCK(imo); lck_mtx_destroy(&imo->imo_lock, ifa_mtx_grp); if (!(imo->imo_debug & IFD_ALLOC)) { panic("%s: imo %p cannot be freed", __func__, imo); /* NOTREACHED */ } zfree(imo_zone, imo); } static void imo_trace(struct ip_moptions *imo, int refhold) { struct ip_moptions_dbg *imo_dbg = (struct ip_moptions_dbg *)imo; ctrace_t *tr; u_int32_t idx; u_int16_t *cnt; if (!(imo->imo_debug & IFD_DEBUG)) { panic("%s: imo %p has no debug structure", __func__, imo); /* NOTREACHED */ } if (refhold) { cnt = &imo_dbg->imo_refhold_cnt; tr = imo_dbg->imo_refhold; } else { cnt = &imo_dbg->imo_refrele_cnt; tr = imo_dbg->imo_refrele; } idx = atomic_add_16_ov(cnt, 1) % IMO_TRACE_HIST_SIZE; ctrace_record(&tr[idx]); } struct ip_moptions * ip_allocmoptions(int how) { struct ip_moptions *imo; imo = (how == M_WAITOK) ? zalloc(imo_zone) : zalloc_noblock(imo_zone); if (imo != NULL) { bzero(imo, imo_size); lck_mtx_init(&imo->imo_lock, ifa_mtx_grp, ifa_mtx_attr); imo->imo_debug |= IFD_ALLOC; if (imo_debug != 0) { imo->imo_debug |= IFD_DEBUG; imo->imo_trace = imo_trace; } IMO_ADDREF(imo); } return (imo); } /* * Routine called from ip_output() to loop back a copy of an IP multicast * packet to the input queue of a specified interface. Note that this * calls the output routine of the loopback "driver", but with an interface * pointer that might NOT be a loopback interface -- evil, but easier than * replicating that code here. */ static void ip_mloopback(ifp, m, dst, hlen) struct ifnet *ifp; register struct mbuf *m; register struct sockaddr_in *dst; int hlen; { register struct ip *ip; struct mbuf *copym; int sw_csum = (apple_hwcksum_tx == 0); copym = m_copy(m, 0, M_COPYALL); if (copym != NULL && (copym->m_flags & M_EXT || copym->m_len < hlen)) copym = m_pullup(copym, hlen); if (copym == NULL) return; /* * We don't bother to fragment if the IP length is greater * than the interface's MTU. Can this possibly matter? */ ip = mtod(copym, struct ip *); #if BYTE_ORDER != BIG_ENDIAN HTONS(ip->ip_len); HTONS(ip->ip_off); #endif ip->ip_sum = 0; ip->ip_sum = in_cksum(copym, hlen); /* * NB: * It's not clear whether there are any lingering * reentrancy problems in other areas which might * be exposed by using ip_input directly (in * particular, everything which modifies the packet * in-place). Yet another option is using the * protosw directly to deliver the looped back * packet. For the moment, we'll err on the side * of safety by using if_simloop(). */ #if 1 /* XXX */ if (dst->sin_family != AF_INET) { printf("ip_mloopback: bad address family %d\n", dst->sin_family); dst->sin_family = AF_INET; } #endif /* * Mark checksum as valid or calculate checksum for loopback. * * This is done this way because we have to embed the ifp of * the interface we will send the original copy of the packet * out on in the mbuf. ip_input will check if_hwassist of the * embedded ifp and ignore all csum_flags if if_hwassist is 0. * The UDP checksum has not been calculated yet. */ if (sw_csum || (copym->m_pkthdr.csum_flags & CSUM_DELAY_DATA)) { if (!sw_csum && IF_HWASSIST_CSUM_FLAGS(ifp->if_hwassist)) { copym->m_pkthdr.csum_flags |= CSUM_DATA_VALID | CSUM_PSEUDO_HDR | CSUM_IP_CHECKED | CSUM_IP_VALID; copym->m_pkthdr.csum_data = 0xffff; } else { #if BYTE_ORDER != BIG_ENDIAN NTOHS(ip->ip_len); #endif in_delayed_cksum(copym); #if BYTE_ORDER != BIG_ENDIAN HTONS(ip->ip_len); #endif } } /* * TedW: * We need to send all loopback traffic down to dlil in case * a filter has tapped-in. */ /* * Stuff the 'real' ifp into the pkthdr, to be used in matching * in ip_input(); we need the loopback ifp/dl_tag passed as args * to make the loopback driver compliant with the data link * requirements. */ if (lo_ifp) { copym->m_pkthdr.rcvif = ifp; dlil_output(lo_ifp, PF_INET, copym, 0, (struct sockaddr *) dst, 0, NULL); } else { printf("Warning: ip_output call to dlil_find_dltag failed!\n"); m_freem(copym); } } /* * Given a source IP address (and route, if available), determine the best * interface to send the packet from. Checking for (and updating) the * ROF_SRCIF_SELECTED flag in the pcb-supplied route placeholder is done * without any locks based on the assumption that ip_output() is single- * threaded per-pcb, i.e. for any given pcb there can only be one thread * performing output at the IP layer. * * This routine is analogous to in6_selectroute() for IPv6. */ static struct ifaddr * in_selectsrcif(struct ip *ip, struct route *ro, unsigned int ifscope) { struct ifaddr *ifa = NULL; struct in_addr src = ip->ip_src; struct in_addr dst = ip->ip_dst; struct ifnet *rt_ifp; char s_src[MAX_IPv4_STR_LEN], s_dst[MAX_IPv4_STR_LEN]; if (ip_select_srcif_debug) { (void) inet_ntop(AF_INET, &src.s_addr, s_src, sizeof (s_src)); (void) inet_ntop(AF_INET, &dst.s_addr, s_dst, sizeof (s_dst)); } if (ro->ro_rt != NULL) RT_LOCK(ro->ro_rt); rt_ifp = (ro->ro_rt != NULL) ? ro->ro_rt->rt_ifp : NULL; /* * Given the source IP address, find a suitable source interface * to use for transmission; if the caller has specified a scope, * optimize the search by looking at the addresses only for that * interface. This is still suboptimal, however, as we need to * traverse the per-interface list. */ if (ifscope != IFSCOPE_NONE || ro->ro_rt != NULL) { unsigned int scope = ifscope; /* * If no scope is specified and the route is stale (pointing * to a defunct interface) use the current primary interface; * this happens when switching between interfaces configured * with the same IP address. Otherwise pick up the scope * information from the route; the ULP may have looked up a * correct route and we just need to verify it here and mark * it with the ROF_SRCIF_SELECTED flag below. */ if (scope == IFSCOPE_NONE) { scope = rt_ifp->if_index; if (scope != get_primary_ifscope(AF_INET) && ro->ro_rt->generation_id != route_generation) scope = get_primary_ifscope(AF_INET); } ifa = (struct ifaddr *)ifa_foraddr_scoped(src.s_addr, scope); if (ifa == NULL && ip->ip_p != IPPROTO_UDP && ip->ip_p != IPPROTO_TCP && ipforwarding) { /* * If forwarding is enabled, and if the packet isn't * TCP or UDP, check if the source address belongs * to one of our own interfaces; if so, demote the * interface scope and do a route lookup right below. */ ifa = (struct ifaddr *)ifa_foraddr(src.s_addr); if (ifa != NULL) { IFA_REMREF(ifa); ifa = NULL; ifscope = IFSCOPE_NONE; } } if (ip_select_srcif_debug && ifa != NULL) { if (ro->ro_rt != NULL) { printf("%s->%s ifscope %d->%d ifa_if %s " "ro_if %s\n", s_src, s_dst, ifscope, scope, if_name(ifa->ifa_ifp), if_name(rt_ifp)); } else { printf("%s->%s ifscope %d->%d ifa_if %s\n", s_src, s_dst, ifscope, scope, if_name(ifa->ifa_ifp)); } } } /* * Slow path; search for an interface having the corresponding source * IP address if the scope was not specified by the caller, and: * * 1) There currently isn't any route, or, * 2) The interface used by the route does not own that source * IP address; in this case, the route will get blown away * and we'll do a more specific scoped search using the newly * found interface. */ if (ifa == NULL && ifscope == IFSCOPE_NONE) { ifa = (struct ifaddr *)ifa_foraddr(src.s_addr); /* * If we have the IP address, but not the route, we don't * really know whether or not it belongs to the correct * interface (it could be shared across multiple interfaces.) * The only way to find out is to do a route lookup. */ if (ifa != NULL && ro->ro_rt == NULL) { struct rtentry *rt; struct sockaddr_in sin; struct ifaddr *oifa = NULL; bzero(&sin, sizeof (sin)); sin.sin_family = AF_INET; sin.sin_len = sizeof (sin); sin.sin_addr = dst; lck_mtx_lock(rnh_lock); if ((rt = rt_lookup(TRUE, (struct sockaddr *)&sin, NULL, rt_tables[AF_INET], IFSCOPE_NONE)) != NULL) { RT_LOCK(rt); /* * If the route uses a different interface, * use that one instead. The IP address of * the ifaddr that we pick up here is not * relevant. */ if (ifa->ifa_ifp != rt->rt_ifp) { oifa = ifa; ifa = rt->rt_ifa; IFA_ADDREF(ifa); RT_UNLOCK(rt); } else { RT_UNLOCK(rt); } rtfree_locked(rt); } lck_mtx_unlock(rnh_lock); if (oifa != NULL) { struct ifaddr *iifa; /* * See if the interface pointed to by the * route is configured with the source IP * address of the packet. */ iifa = (struct ifaddr *)ifa_foraddr_scoped( src.s_addr, ifa->ifa_ifp->if_index); if (iifa != NULL) { /* * Found it; drop the original one * as well as the route interface * address, and use this instead. */ IFA_REMREF(oifa); IFA_REMREF(ifa); ifa = iifa; } else if (!ipforwarding || (rt->rt_flags & RTF_GATEWAY)) { /* * This interface doesn't have that * source IP address; drop the route * interface address and just use the * original one, and let the caller * do a scoped route lookup. */ IFA_REMREF(ifa); ifa = oifa; } else { /* * Forwarding is enabled and the source * address belongs to one of our own * interfaces which isn't the outgoing * interface, and we have a route, and * the destination is on a network that * is directly attached (onlink); drop * the original one and use the route * interface address instead. */ IFA_REMREF(oifa); } } } else if (ifa != NULL && ro->ro_rt != NULL && !(ro->ro_rt->rt_flags & RTF_GATEWAY) && ifa->ifa_ifp != ro->ro_rt->rt_ifp && ipforwarding) { /* * Forwarding is enabled and the source address belongs * to one of our own interfaces which isn't the same * as the interface used by the known route; drop the * original one and use the route interface address. */ IFA_REMREF(ifa); ifa = ro->ro_rt->rt_ifa; IFA_ADDREF(ifa); } if (ip_select_srcif_debug && ifa != NULL) { printf("%s->%s ifscope %d ifa_if %s\n", s_src, s_dst, ifscope, if_name(ifa->ifa_ifp)); } } if (ro->ro_rt != NULL) RT_LOCK_ASSERT_HELD(ro->ro_rt); /* * If there is a non-loopback route with the wrong interface, or if * there is no interface configured with such an address, blow it * away. Except for local/loopback, we look for one with a matching * interface scope/index. */ if (ro->ro_rt != NULL && (ifa == NULL || (ifa->ifa_ifp != rt_ifp && rt_ifp != lo_ifp) || !(ro->ro_rt->rt_flags & RTF_UP))) { if (ip_select_srcif_debug) { if (ifa != NULL) { printf("%s->%s ifscope %d ro_if %s != " "ifa_if %s (cached route cleared)\n", s_src, s_dst, ifscope, if_name(rt_ifp), if_name(ifa->ifa_ifp)); } else { printf("%s->%s ifscope %d ro_if %s " "(no ifa_if found)\n", s_src, s_dst, ifscope, if_name(rt_ifp)); } } RT_UNLOCK(ro->ro_rt); rtfree(ro->ro_rt); ro->ro_rt = NULL; ro->ro_flags &= ~ROF_SRCIF_SELECTED; /* * If the destination is IPv4 LLA and the route's interface * doesn't match the source interface, then the source IP * address is wrong; it most likely belongs to the primary * interface associated with the IPv4 LL subnet. Drop the * packet rather than letting it go out and return an error * to the ULP. This actually applies not only to IPv4 LL * but other shared subnets; for now we explicitly test only * for the former case and save the latter for future. */ if (IN_LINKLOCAL(ntohl(dst.s_addr)) && !IN_LINKLOCAL(ntohl(src.s_addr)) && ifa != NULL) { IFA_REMREF(ifa); ifa = NULL; } } if (ip_select_srcif_debug && ifa == NULL) { printf("%s->%s ifscope %d (neither ro_if/ifa_if found)\n", s_src, s_dst, ifscope); } /* * If there is a route, mark it accordingly. If there isn't one, * we'll get here again during the next transmit (possibly with a * route) and the flag will get set at that point. For IPv4 LLA * destination, mark it only if the route has been fully resolved; * otherwise we want to come back here again when the route points * to the interface over which the ARP reply arrives on. */ if (ro->ro_rt != NULL && (!IN_LINKLOCAL(ntohl(dst.s_addr)) || (ro->ro_rt->rt_gateway->sa_family == AF_LINK && SDL(ro->ro_rt->rt_gateway)->sdl_alen != 0))) { ro->ro_flags |= ROF_SRCIF_SELECTED; ro->ro_rt->generation_id = route_generation; } if (ro->ro_rt != NULL) RT_UNLOCK(ro->ro_rt); return (ifa); }