/* * Copyright (c) 2000-2023 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 */ /* * 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 #include #include #include #include #include #include #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) #if IPSEC #include #include #if IPSEC_DEBUG #include #else #define KEYDEBUG(lev, arg) #endif #endif /* IPSEC */ #if NECP #include #endif /* NECP */ #if DUMMYNET #include #endif #if PF #include #endif /* PF */ #include u_short ip_id; static int sysctl_reset_ip_output_stats SYSCTL_HANDLER_ARGS; static int sysctl_ip_output_measure_bins SYSCTL_HANDLER_ARGS; static int sysctl_ip_output_getperf SYSCTL_HANDLER_ARGS; static void ip_out_cksum_stats(int, u_int32_t); static struct mbuf *ip_insertoptions(struct mbuf *, struct mbuf *, int *); static int ip_optcopy(struct ip *, struct ip *); static int ip_pcbopts(int, struct mbuf **, struct mbuf *); static void imo_trace(struct ip_moptions *, int); static void ip_mloopback(struct ifnet *, struct ifnet *, struct mbuf *, struct sockaddr_in *, int); static struct ifaddr *in_selectsrcif(struct ip *, struct route *, unsigned int); extern struct ip_linklocal_stat ip_linklocal_stat; /* temporary: for testing */ #if IPSEC extern int ipsec_bypass; #endif static int force_ipsum = 0; static int ip_maxchainsent = 0; SYSCTL_INT(_net_inet_ip, OID_AUTO, maxchainsent, CTLFLAG_RW | CTLFLAG_LOCKED, &ip_maxchainsent, 0, "use dlil_output_list"); SYSCTL_INT(_net_inet_ip, OID_AUTO, force_ipsum, CTLFLAG_RW | CTLFLAG_LOCKED, &force_ipsum, 0, "force IP checksum"); #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"); static int ip_output_measure = 0; SYSCTL_PROC(_net_inet_ip, OID_AUTO, output_perf, CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_LOCKED, &ip_output_measure, 0, sysctl_reset_ip_output_stats, "I", "Do time measurement"); static uint64_t ip_output_measure_bins = 0; SYSCTL_PROC(_net_inet_ip, OID_AUTO, output_perf_bins, CTLTYPE_QUAD | CTLFLAG_RW | CTLFLAG_LOCKED, &ip_output_measure_bins, 0, sysctl_ip_output_measure_bins, "I", "bins for chaining performance data histogram"); static net_perf_t net_perf; SYSCTL_PROC(_net_inet_ip, OID_AUTO, output_perf_data, CTLTYPE_STRUCT | CTLFLAG_RD | CTLFLAG_LOCKED, 0, 0, sysctl_ip_output_getperf, "S,net_perf", "IP output performance data (struct net_perf, net/net_perf.h)"); __private_extern__ int rfc6864 = 1; SYSCTL_INT(_net_inet_ip, OID_AUTO, rfc6864, CTLFLAG_RW | CTLFLAG_LOCKED, &rfc6864, 0, "updated ip id field behavior"); #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 struct zone *imo_zone; /* zone for ip_moptions */ #define IMO_ZONE_NAME "ip_moptions" /* zone name */ #if PF __attribute__((noinline)) static int ip_output_pf_dn_hook(struct ifnet *ifp, struct mbuf **mppn, struct mbuf **mp, struct pf_rule *dn_pf_rule, struct route *ro, struct sockaddr_in *dst, int flags, struct ip_out_args *ipoa) { int rc; struct ip_fw_args args = {}; args.fwa_pf_rule = dn_pf_rule; 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, mp, AF_INET, FALSE, &args); return rc; } #endif /* PF */ /* * 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) { return ip_output_list(m0, 0, opt, ro, flags, imo, ipoa); } /* * 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. * * Route ro MUST be non-NULL; if ro->ro_rt is valid, route lookup would be * skipped and ro->ro_rt would be used. Otherwise the result of route * lookup is stored in ro->ro_rt. * * In the IP forwarding case, the packet will arrive with options already * inserted, so must have a NULL opt pointer. */ 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; /* not refcnt'd */ 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; struct in_addr pkt_dst; struct ipf_pktopts *ippo = NULL; ipfilter_t inject_filter_ref = NULL; struct mbuf *packetlist; uint32_t sw_csum, pktcnt = 0, scnt = 0, bytecnt = 0; uint32_t packets_processed = 0; unsigned int ifscope = IFSCOPE_NONE; struct flowadv *adv = NULL; struct timeval start_tv; #if IPSEC struct socket *so = NULL; struct secpolicy *sp = NULL; #endif /* IPSEC */ #if NECP necp_kernel_policy_result necp_result = 0; necp_kernel_policy_result_parameter necp_result_parameter; necp_kernel_policy_id necp_matched_policy_id = 0; #endif /* NECP */ #if DUMMYNET struct m_tag *tag; struct ip_out_args saved_ipoa; struct sockaddr_in dst_buf; #endif /* DUMMYNET */ struct { #if IPSEC struct ipsec_output_state ipsec_state; #endif /* IPSEC */ #if NECP struct route necp_route; #endif /* NECP */ #if DUMMYNET struct route saved_route; #endif /* DUMMYNET */ struct ipf_pktopts ipf_pktopts; } ipobz; #define ipsec_state ipobz.ipsec_state #define necp_route ipobz.necp_route #define sro_fwd ipobz.sro_fwd #define saved_route ipobz.saved_route #define ipf_pktopts ipobz.ipf_pktopts union { struct { boolean_t select_srcif : 1; /* set once */ boolean_t srcbound : 1; /* set once */ boolean_t nocell : 1; /* set once */ boolean_t isbroadcast : 1; boolean_t didfilter : 1; boolean_t noexpensive : 1; /* set once */ boolean_t noconstrained : 1; /* set once */ boolean_t awdl_unrestricted : 1; /* set once */ boolean_t management_allowed : 1; /* set once */ }; uint32_t raw; } ipobf = { .raw = 0 }; int interface_mtu = 0; struct pf_rule *dn_pf_rule = NULL; /* * Here we check for restrictions when sending frames. * N.B.: IPv4 over internal co-processor interfaces is not allowed. */ #define IP_CHECK_RESTRICTIONS(_ifp, _ipobf) \ (((_ipobf).nocell && IFNET_IS_CELLULAR(_ifp)) || \ ((_ipobf).noexpensive && IFNET_IS_EXPENSIVE(_ifp)) || \ ((_ipobf).noconstrained && IFNET_IS_CONSTRAINED(_ifp)) || \ (IFNET_IS_INTCOPROC(_ifp)) || \ (!(_ipobf).management_allowed && IFNET_IS_MANAGEMENT(_ifp)) || \ (!(_ipobf).awdl_unrestricted && IFNET_IS_AWDL_RESTRICTED(_ifp))) if (ip_output_measure) { net_perf_start_time(&net_perf, &start_tv); } KERNEL_DEBUG(DBG_FNC_IP_OUTPUT | DBG_FUNC_START, 0, 0, 0, 0, 0); VERIFY(m0->m_flags & M_PKTHDR); packetlist = m0; /* zero out {ipsec_state, args, sro_fwd, saved_route, ipf_pktops} */ bzero(&ipobz, sizeof(ipobz)); ippo = &ipf_pktopts; #if DUMMYNET if (SLIST_EMPTY(&m0->m_pkthdr.tags)) { goto ipfw_tags_done; } /* Grab info from mtags prepended to the chain */ if ((tag = m_tag_locate(m0, KERNEL_MODULE_TAG_ID, KERNEL_TAG_TYPE_DUMMYNET)) != NULL) { struct dn_pkt_tag *dn_tag; dn_tag = (struct dn_pkt_tag *)(tag->m_tag_data); dn_pf_rule = dn_tag->dn_pf_rule; opt = NULL; saved_route = dn_tag->dn_ro; ro = &saved_route; imo = NULL; SOCKADDR_COPY(&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); } ipfw_tags_done: #endif /* DUMMYNET */ m = m0; m->m_pkthdr.pkt_flags &= ~(PKTF_LOOP | PKTF_IFAINFO); #if IPSEC if (ipsec_bypass == 0 && !(flags & IP_NOIPSEC)) { /* If packet is bound to an interface, check bound policies */ if ((flags & IP_OUTARGS) && (ipoa != NULL) && (ipoa->ipoa_flags & IPOAF_BOUND_IF) && ipoa->ipoa_boundif != IFSCOPE_NONE) { if (ipsec4_getpolicybyinterface(m, IPSEC_DIR_OUTBOUND, &flags, ipoa, &sp) != 0) { goto bad; } } } #endif /* IPSEC */ VERIFY(ro != NULL); if (flags & IP_OUTARGS) { /* * In the forwarding case, only the ifscope value is used, * as source interface selection doesn't take place. */ if ((ipobf.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)); } /* double negation needed for bool bit field */ ipobf.srcbound = !!(ipoa->ipoa_flags & IPOAF_BOUND_SRCADDR); if (ipobf.srcbound) { ipf_pktopts.ippo_flags |= IPPOF_BOUND_SRCADDR; } } else { ipobf.select_srcif = FALSE; ipobf.srcbound = FALSE; ifscope = IFSCOPE_NONE; if (flags & IP_OUTARGS) { ipoa->ipoa_boundif = IFSCOPE_NONE; ipoa->ipoa_flags &= ~(IPOAF_SELECT_SRCIF | IPOAF_BOUND_IF | IPOAF_BOUND_SRCADDR); } } if (flags & IP_OUTARGS) { if (ipoa->ipoa_flags & IPOAF_NO_CELLULAR) { ipobf.nocell = true; ipf_pktopts.ippo_flags |= IPPOF_NO_IFT_CELLULAR; } if (ipoa->ipoa_flags & IPOAF_NO_EXPENSIVE) { ipobf.noexpensive = true; ipf_pktopts.ippo_flags |= IPPOF_NO_IFF_EXPENSIVE; } if (ipoa->ipoa_flags & IPOAF_NO_CONSTRAINED) { ipobf.noconstrained = true; ipf_pktopts.ippo_flags |= IPPOF_NO_IFF_CONSTRAINED; } if (ipoa->ipoa_flags & IPOAF_AWDL_UNRESTRICTED) { ipobf.awdl_unrestricted = true; } if (ipoa->ipoa_flags & IPOAF_MANAGEMENT_ALLOWED) { ipobf.management_allowed = true; } adv = &ipoa->ipoa_flowadv; adv->code = FADV_SUCCESS; ipoa->ipoa_flags &= ~IPOAF_RET_MASK; } #if IPSEC if (ipsec_bypass == 0 && !(flags & IP_NOIPSEC)) { so = ipsec_getsocket(m); if (so != NULL) { (void) ipsec_setsocket(m, NULL); } } #endif /* IPSEC */ #if DUMMYNET if (dn_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); } goto sendit; } #endif /* DUMMYNET */ loopit: packets_processed++; ipobf.isbroadcast = FALSE; ipobf.didfilter = FALSE; VERIFY(m->m_flags & M_PKTHDR); /* * 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 = NULL; } 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 *); pkt_dst = ip->ip_dst; /* * 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))) { ip->ip_vhl = IP_MAKE_VHL(IPVERSION, hlen >> 2); ip->ip_off &= IP_DF; if (rfc6864 && IP_OFF_IS_ATOMIC(ip->ip_off)) { // Per RFC6864, value of ip_id is undefined for atomic ip packets ip->ip_id = 0; } else { ip->ip_id = ip_randomid((uint64_t)m); } 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 */ if ((ip->ip_tos & IPTOS_ECN_MASK) == IPTOS_ECN_ECT1) { m->m_pkthdr.pkt_ext_flags |= PKTF_EXT_L4S; } 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 = SIN(&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 (ROUTE_UNUSABLE(ro) && ip->ip_src.s_addr != INADDR_ANY && !(flags & (IP_ROUTETOIF | IP_FORWARDING))) { src_ia = ifa_foraddr(ip->ip_src.s_addr); if (src_ia == NULL) { error = EADDRNOTAVAIL; goto bad; } ifa_remref(&src_ia->ia_ifa); src_ia = NULL; } /* * 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 (ROUTE_UNUSABLE(ro) || dst->sin_family != AF_INET || dst->sin_addr.s_addr != pkt_dst.s_addr) { ROUTE_RELEASE(ro); } /* * If we're doing source interface selection, we may not * want to use this route; only synch up the generation * count otherwise. */ if (!ipobf.select_srcif && ro->ro_rt != NULL && RT_GENID_OUTOFSYNC(ro->ro_rt)) { RT_GENID_SYNC(ro->ro_rt); } } if (ro->ro_rt == NULL) { SOCKADDR_ZERO(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 != NULL) { ifa_remref(&ia->ia_ifa); } if ((ia = ifatoia(ifa_ifwithdstaddr(sintosa(dst)))) == NULL) { ia = ifatoia(ifa_ifwithnet(sintosa(dst))); if (ia == NULL) { OSAddAtomic(1, &ipstat.ips_noroute); error = ENETUNREACH; /* XXX IPv6 APN fallback notification?? */ goto bad; } } ifp = ia->ia_ifp; ip->ip_ttl = 1; ipobf.isbroadcast = in_broadcast(dst->sin_addr, ifp); /* * For consistency with other cases below. Loopback * multicast case is handled separately by ip_mloopback(). */ if ((ifp->if_flags & IFF_LOOPBACK) && !IN_MULTICAST(ntohl(pkt_dst.s_addr))) { m->m_pkthdr.rcvif = ifp; ip_setsrcifaddr_info(m, ifp->if_index, NULL); ip_setdstifaddr_info(m, ifp->if_index, NULL); } } 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. */ ipobf.isbroadcast = FALSE; if (ia != NULL) { ifa_remref(&ia->ia_ifa); } /* Macro takes reference on ia */ IFP_TO_IA(ifp, ia); } else { struct ifaddr *ia0 = NULL; 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 (ipobf.select_srcif && ip->ip_src.s_addr != INADDR_ANY && (ROUTE_UNUSABLE(ro) || !(ro->ro_flags & ROF_SRCIF_SELECTED))) { /* Find the source interface */ ia0 = in_selectsrcif(ip, ro, ifscope); /* * If the source address belongs to a restricted * interface and the caller forbids our using * interfaces of such type, pretend that there is no * route. */ if (ia0 != NULL && IP_CHECK_RESTRICTIONS(ia0->ifa_ifp, ipobf)) { ifa_remref(ia0); ia0 = NULL; error = EHOSTUNREACH; if (flags & IP_OUTARGS) { ipoa->ipoa_flags |= IPOAF_R_IFDENIED; } 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 (ia0 == NULL && (!(flags & IP_RAWOUTPUT) || ipobf.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 (ia0 != NULL) { if (ifscope == IFSCOPE_NONE) { ifscope = ia0->ifa_ifp->if_index; } 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) { uint32_t 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/expensive interface * and the caller forbids our using interfaces of such type, * pretend that there is no route. */ if (ro->ro_rt != NULL) { RT_LOCK_SPIN(ro->ro_rt); if (IP_CHECK_RESTRICTIONS(ro->ro_rt->rt_ifp, ipobf)) { RT_UNLOCK(ro->ro_rt); ROUTE_RELEASE(ro); if (flags & IP_OUTARGS) { ipoa->ipoa_flags |= IPOAF_R_IFDENIED; } } else { RT_UNLOCK(ro->ro_rt); } } } if (ro->ro_rt == NULL) { OSAddAtomic(1, &ipstat.ips_noroute); error = EHOSTUNREACH; if (ia0 != NULL) { ifa_remref(ia0); ia0 = NULL; } goto bad; } if (ia != NULL) { ifa_remref(&ia->ia_ifa); } RT_LOCK_SPIN(ro->ro_rt); ia = ifatoia(ro->ro_rt->rt_ifa); if (ia != NULL) { /* Become a regular mutex */ RT_CONVERT_LOCK(ro->ro_rt); ifa_addref(&ia->ia_ifa); } /* * Note: ia_ifp may not be the same as rt_ifp; the latter * is what we use for determining outbound i/f, mtu, etc. */ ifp = ro->ro_rt->rt_ifp; ro->ro_rt->rt_use++; if (ro->ro_rt->rt_flags & RTF_GATEWAY) { dst = SIN(ro->ro_rt->rt_gateway); } if (ro->ro_rt->rt_flags & RTF_HOST) { /* double negation needed for bool bit field */ ipobf.isbroadcast = !!(ro->ro_rt->rt_flags & RTF_BROADCAST); } else { /* Become a regular mutex */ RT_CONVERT_LOCK(ro->ro_rt); ipobf.isbroadcast = in_broadcast(dst->sin_addr, ifp); } /* * For consistency with IPv6, as well as to ensure that * IP_RECVIF is set correctly for packets that are sent * to one of the local addresses. ia (rt_ifa) would have * been fixed up by rt_setif for local routes. This * would make it appear as if the packet arrives on the * interface which owns the local address. Loopback * multicast case is handled separately by ip_mloopback(). */ if (ia != NULL && (ifp->if_flags & IFF_LOOPBACK) && !IN_MULTICAST(ntohl(pkt_dst.s_addr))) { uint16_t srcidx; m->m_pkthdr.rcvif = ia->ia_ifa.ifa_ifp; if (ia0 != NULL) { srcidx = ia0->ifa_ifp->if_index; } else if ((ro->ro_flags & ROF_SRCIF_SELECTED) && ro->ro_srcia != NULL) { srcidx = ro->ro_srcia->ifa_ifp->if_index; } else { srcidx = 0; } ip_setsrcifaddr_info(m, srcidx, NULL); ip_setdstifaddr_info(m, 0, ia); } RT_UNLOCK(ro->ro_rt); if (ia0 != NULL) { ifa_remref(ia0); ia0 = NULL; } } if (IN_MULTICAST(ntohl(pkt_dst.s_addr))) { struct ifnet *srcifp = NULL; struct in_multi *inm; u_int32_t vif = 0; 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 = SIN(&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)) { ip->ip_ttl = ttl; } if (imo->imo_multicast_ifp != NULL) { ifp = imo->imo_multicast_ifp; } IMO_UNLOCK(imo); } else if (!(flags & IP_RAWOUTPUT)) { vif = -1; ip->ip_ttl = ttl; } /* * Confirm that the outgoing interface supports multicast. */ if (imo == NULL || vif == -1) { if (!(ifp->if_flags & IFF_MULTICAST)) { 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; srcifp = ifp; 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) #if NECP && !necp_packet_should_skip_filters(m) #endif // NECP ) { struct ipfilter *filter; int seen = (inject_filter_ref == NULL); 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 != NULL) { 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(); ipobf.didfilter = true; } ip_mloopback(srcifp, ifp, m, dst, hlen); } 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); } /* * Look for broadcast address and * and verify user is allowed to send * such a packet. */ if (ipobf.isbroadcast) { if (!(ifp->if_flags & IFF_BROADCAST)) { error = EADDRNOTAVAIL; goto bad; } if (!(flags & IP_ALLOWBROADCAST)) { 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 rc = ip_output_pf_dn_hook(ifp, mppn, &m, dn_pf_rule, ro, dst, flags, ipoa); #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 (!ipobf.didfilter && !TAILQ_EMPTY(&ipv4_filters) #if NECP && !necp_packet_should_skip_filters(m) #endif // NECP ) { struct ipfilter *filter; int seen = (inject_filter_ref == NULL); 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 NECP /* Process Network Extension Policy. Will Pass, Drop, or Rebind packet. */ necp_matched_policy_id = necp_ip_output_find_policy_match(m, flags, (flags & IP_OUTARGS) ? ipoa : NULL, ro ? ro->ro_rt : NULL, &necp_result, &necp_result_parameter); if (necp_matched_policy_id) { necp_mark_packet_from_ip(m, necp_matched_policy_id); switch (necp_result) { case NECP_KERNEL_POLICY_RESULT_PASS: if (necp_result_parameter.pass_flags & NECP_KERNEL_POLICY_PASS_NO_SKIP_IPSEC) { break; } /* Check if the interface is allowed */ if (!necp_packet_is_allowed_over_interface(m, ifp)) { error = EHOSTUNREACH; OSAddAtomic(1, &ipstat.ips_necp_policy_drop); goto bad; } goto skip_ipsec; case NECP_KERNEL_POLICY_RESULT_DROP: case NECP_KERNEL_POLICY_RESULT_SOCKET_DIVERT: /* Flow divert packets should be blocked at the IP layer */ error = EHOSTUNREACH; OSAddAtomic(1, &ipstat.ips_necp_policy_drop); goto bad; case NECP_KERNEL_POLICY_RESULT_IP_TUNNEL: { /* Verify that the packet is being routed to the tunnel */ struct ifnet *policy_ifp = necp_get_ifnet_from_result_parameter(&necp_result_parameter); if (policy_ifp == ifp) { /* Check if the interface is allowed */ if (!necp_packet_is_allowed_over_interface(m, ifp)) { error = EHOSTUNREACH; OSAddAtomic(1, &ipstat.ips_necp_policy_drop); goto bad; } goto skip_ipsec; } else { if (necp_packet_can_rebind_to_ifnet(m, policy_ifp, &necp_route, AF_INET)) { /* Check if the interface is allowed */ if (!necp_packet_is_allowed_over_interface(m, policy_ifp)) { error = EHOSTUNREACH; OSAddAtomic(1, &ipstat.ips_necp_policy_drop); goto bad; } /* * Update the QOS marking policy if * 1. up layer asks it to do so * 2. net_qos_policy_restricted is not set * 3. qos_marking_gencount doesn't match necp_kernel_socket_policies_gencount (checked in necp_lookup_current_qos_marking) */ if (ipoa != NULL && (ipoa->ipoa_flags & IPOAF_REDO_QOSMARKING_POLICY) && net_qos_policy_restricted != 0) { bool qos_marking = (ipoa->ipoa_flags & IPOAF_QOSMARKING_ALLOWED) ? TRUE : FALSE; qos_marking = necp_lookup_current_qos_marking(&ipoa->qos_marking_gencount, NULL, policy_ifp, necp_result_parameter.route_rule_id, qos_marking); if (qos_marking) { ipoa->ipoa_flags |= IPOAF_QOSMARKING_ALLOWED; } else { ipoa->ipoa_flags &= ~IPOAF_QOSMARKING_ALLOWED; } } /* Set ifp to the tunnel interface, since it is compatible with the packet */ ifp = policy_ifp; ro = &necp_route; goto skip_ipsec; } else { error = ENETUNREACH; OSAddAtomic(1, &ipstat.ips_necp_policy_drop); goto bad; } } } default: break; } } /* Catch-all to check if the interface is allowed */ if (!necp_packet_is_allowed_over_interface(m, ifp)) { error = EHOSTUNREACH; OSAddAtomic(1, &ipstat.ips_necp_policy_drop); goto bad; } #endif /* NECP */ #if IPSEC if (ipsec_bypass != 0 || (flags & IP_NOIPSEC)) { goto skip_ipsec; } KERNEL_DEBUG(DBG_FNC_IPSEC4_OUTPUT | DBG_FUNC_START, 0, 0, 0, 0, 0); if (sp == NULL) { /* get SP for this packet */ if (so != NULL) { sp = ipsec4_getpolicybysock(m, IPSEC_DIR_OUTBOUND, so, &error); } else { sp = ipsec4_getpolicybyaddr(m, IPSEC_DIR_OUTBOUND, flags, &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; } if (sp->ipsec_if) { /* Verify the redirect to ipsec interface */ if (sp->ipsec_if == ifp) { goto skip_ipsec; } 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((struct route *)&ipsec_state.ro, ro, sizeof(struct route)); } ipsec_state.dst = SA(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); } #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); if (ipsec_state.tunneled == 6) { m0 = m = NULL; error = 0; goto bad; } m0 = m = ipsec_state.m; #if DUMMYNET /* * If we're about to use the route in ipsec_state * and this came from dummynet, cleaup now. */ if (ro == &saved_route && (!(flags & IP_ROUTETOIF) || ipsec_state.tunneled)) { ROUTE_RELEASE(ro); } #endif /* DUMMYNET */ if (flags & IP_ROUTETOIF) { /* * if we have tunnel mode SA, we may need to ignore * IP_ROUTETOIF. */ if (ipsec_state.tunneled) { flags &= ~IP_ROUTETOIF; ro = (struct route *)&ipsec_state.ro; } } else { ro = (struct route *)&ipsec_state.ro; } dst = SIN(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); OS_FALLTHROUGH; 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 /* !_IP_VHL */ hlen = ip->ip_hl << 2; #endif /* !_IP_VHL */ /* Check that there wasn't a route change and src is still valid */ if (ROUTE_UNUSABLE(ro)) { ROUTE_RELEASE(ro); VERIFY(src_ia == NULL); if (ip->ip_src.s_addr != INADDR_ANY && !(flags & (IP_ROUTETOIF | IP_FORWARDING)) && (src_ia = ifa_foraddr(ip->ip_src.s_addr)) == NULL) { error = EADDRNOTAVAIL; KERNEL_DEBUG(DBG_FNC_IPSEC4_OUTPUT | DBG_FUNC_END, 5, 0, 0, 0, 0); goto bad; } if (src_ia != NULL) { ifa_remref(&src_ia->ia_ifa); src_ia = NULL; } } if (ro->ro_rt == NULL) { if (!(flags & IP_ROUTETOIF)) { printf("%s: can't update route after " "IPsec processing\n", __func__); error = EHOSTUNREACH; /* XXX */ KERNEL_DEBUG(DBG_FNC_IPSEC4_OUTPUT | DBG_FUNC_END, 6, 0, 0, 0, 0); goto bad; } } else { if (ia != NULL) { ifa_remref(&ia->ia_ifa); } RT_LOCK_SPIN(ro->ro_rt); ia = ifatoia(ro->ro_rt->rt_ifa); if (ia != NULL) { /* 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) #if NECP && !necp_packet_should_skip_filters(m) #endif // NECP ) { 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 */ /* 127/8 must not appear on wire - RFC1122 */ if (!(ifp->if_flags & IFF_LOOPBACK) && ((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); error = EADDRNOTAVAIL; goto bad; } if (ipoa != NULL) { u_int8_t dscp = ip->ip_tos >> IPTOS_DSCP_SHIFT; error = set_packet_qos(m, ifp, ipoa->ipoa_flags & IPOAF_QOSMARKING_ALLOWED ? TRUE : FALSE, ipoa->ipoa_sotc, ipoa->ipoa_netsvctype, &dscp); if (error == 0) { ip->ip_tos &= IPTOS_ECN_MASK; ip->ip_tos |= (u_char)(dscp << IPTOS_DSCP_SHIFT); } else { printf("%s if_dscp_for_mbuf() error %d\n", __func__, error); error = 0; } } ip_output_checksum(ifp, m, (IP_VHL_HL(ip->ip_vhl) << 2), ip->ip_len, &sw_csum); interface_mtu = ifp->if_mtu; if (INTF_ADJUST_MTU_FOR_CLAT46(ifp)) { interface_mtu = IN6_LINKMTU(ifp); /* Further adjust the size for CLAT46 expansion */ interface_mtu -= CLAT46_HDR_EXPANSION_OVERHD; } /* * 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 <= interface_mtu || TSO_IPV4_OK(ifp, m) || (!(ip->ip_off & IP_DF) && (ifp->if_hwassist & CSUM_FRAGMENT))) { #if BYTE_ORDER != BIG_ENDIAN HTONS(ip->ip_len); HTONS(ip->ip_off); #endif ip->ip_sum = 0; if ((sw_csum & CSUM_DELAY_IP) || __improbable(force_ipsum != 0)) { ip->ip_sum = ip_cksum_hdr_out(m, hlen); sw_csum &= ~CSUM_DELAY_IP; m->m_pkthdr.csum_flags &= ~CSUM_DELAY_IP; } #if IPSEC /* clean ipsec history once it goes out of the node */ if (ipsec_bypass == 0 && !(flags & IP_NOIPSEC)) { ipsec_delaux(m); } #endif /* IPSEC */ if ((m->m_pkthdr.csum_flags & CSUM_TSO_IPV4) && (m->m_pkthdr.tso_segsz > 0)) { scnt += m->m_pkthdr.len / m->m_pkthdr.tso_segsz; } else { scnt++; } if (packetchain == 0) { if (ro->ro_rt != NULL && nstat_collect) { nstat_route_tx(ro->ro_rt, scnt, m->m_pkthdr.len, 0); } error = dlil_output(ifp, PF_INET, m, ro->ro_rt, SA(dst), 0, adv); if (dlil_verbose && error) { printf("dlil_output error on interface %s: %d\n", ifp->if_xname, error); } scnt = 0; 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 != NULL && nstat_collect) { nstat_route_tx(ro->ro_rt, scnt, bytecnt, 0); } error = dlil_output(ifp, PF_INET, packetlist, ro->ro_rt, SA(dst), 0, adv); if (dlil_verbose && error) { printf("dlil_output error on interface %s: %d\n", ifp->if_xname, error); } pktcnt = 0; scnt = 0; bytecnt = 0; goto done; } m0 = m; pktcnt++; goto loopit; } } VERIFY(interface_mtu != 0); /* * Too large for interface; fragment if possible. * Must be able to put at least 8 bytes per fragment. * Balk when DF bit is set or the interface didn't support TSO. */ if ((ip->ip_off & IP_DF) || pktcnt > 0 || (m->m_pkthdr.csum_flags & CSUM_TSO_IPV4)) { 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 > interface_mtu)) { ro->ro_rt->rt_rmx.rmx_mtu = interface_mtu; } RT_UNLOCK(ro->ro_rt); } if (pktcnt > 0) { m0 = packetlist; } OSAddAtomic(1, &ipstat.ips_cantfrag); goto bad; } /* * XXX Only TCP seems to be passing a list of packets here. * The following issue is limited to UDP datagrams with 0 checksum. * For now limit it to the case when single packet is passed down. */ if (packetchain == 0 && IS_INTF_CLAT46(ifp)) { /* * If it is a UDP packet that has checksum set to 0 * and is also not being offloaded, compute a full checksum * and update the UDP checksum. */ if (ip->ip_p == IPPROTO_UDP && !(m->m_pkthdr.csum_flags & (CSUM_UDP | CSUM_PARTIAL))) { struct udphdr *uh = NULL; if (m->m_len < hlen + sizeof(struct udphdr)) { m = m_pullup(m, hlen + sizeof(struct udphdr)); if (m == NULL) { error = ENOBUFS; m0 = m; goto bad; } m0 = m; ip = mtod(m, struct ip *); } /* * Get UDP header and if checksum is 0, then compute the full * checksum. */ uh = (struct udphdr *)(void *)((caddr_t)ip + hlen); if (uh->uh_sum == 0) { uh->uh_sum = inet_cksum(m, IPPROTO_UDP, hlen, ip->ip_len - hlen); if (uh->uh_sum == 0) { uh->uh_sum = 0xffff; } } } } error = ip_fragment(m, ifp, interface_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)) { ipsec_delaux(m); } #endif /* IPSEC */ if (error == 0) { if ((packetchain != 0) && (pktcnt > 0)) { panic("%s: mix of packet in packetlist is " "wrong=%p", __func__, packetlist); /* NOTREACHED */ } if (ro->ro_rt != NULL && nstat_collect) { nstat_route_tx(ro->ro_rt, 1, m->m_pkthdr.len, 0); } error = dlil_output(ifp, PF_INET, m, ro->ro_rt, SA(dst), 0, adv); if (dlil_verbose && error) { printf("dlil_output error on interface %s: %d\n", ifp->if_xname, error); } } else { m_freem(m); } } if (error == 0) { OSAddAtomic(1, &ipstat.ips_fragmented); } done: if (ia != NULL) { ifa_remref(&ia->ia_ifa); ia = NULL; } #if IPSEC ROUTE_RELEASE(&ipsec_state.ro); 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 */ #if NECP ROUTE_RELEASE(&necp_route); #endif /* NECP */ #if DUMMYNET ROUTE_RELEASE(&saved_route); #endif /* DUMMYNET */ KERNEL_DEBUG(DBG_FNC_IP_OUTPUT | DBG_FUNC_END, error, 0, 0, 0, 0); if (ip_output_measure) { net_perf_measure_time(&net_perf, &start_tv, packets_processed); net_perf_histogram(&net_perf, packets_processed); } return error; bad: if (pktcnt > 0) { m0 = packetlist; } m_freem_list(m0); goto done; #undef ipsec_state #undef args #undef sro_fwd #undef saved_route #undef ipf_pktopts #undef IP_CHECK_RESTRICTIONS } int ip_fragment(struct mbuf *m, struct ifnet *ifp, uint32_t 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 /* !_IP_VHL */ hlen = ip->ip_hl << 2; #endif /* !_IP_VHL */ /* * We need to adjust the fragment sizes to account * for IPv6 fragment header if it needs to be translated * from IPv4 to IPv6. */ if (IS_INTF_CLAT46(ifp)) { mtu -= sizeof(struct ip6_frag); } 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)) { in_delayed_cksum(m); } /* * 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 == NULL) { 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 = (u_short)(((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 == NULL) { (void) m_free(m); error = ENOBUFS; /* ??? */ OSAddAtomic(1, &ipstat.ips_odropped); goto sendorfree; } m->m_pkthdr.len = mhlen + len; m->m_pkthdr.rcvif = NULL; m->m_pkthdr.csum_flags = m0->m_pkthdr.csum_flags; M_COPY_CLASSIFIER(m, m0); M_COPY_PFTAG(m, m0); M_COPY_NECPTAG(m, m0); #if BYTE_ORDER != BIG_ENDIAN HTONS(mhip->ip_off); #endif mhip->ip_sum = 0; if (sw_csum & CSUM_DELAY_IP) { mhip->ip_sum = ip_cksum_hdr_out(m, mhlen); m->m_pkthdr.csum_flags &= ~CSUM_DELAY_IP; } *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 = ip_cksum_hdr_out(m, hlen); m->m_pkthdr.csum_flags &= ~CSUM_DELAY_IP; } 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; } } /* * Process a delayed payload checksum calculation (outbound path.) * * hoff is the number of bytes beyond the mbuf data pointer which * points to the IP header. * * Returns a bitmask representing all the work done in software. */ uint32_t in_finalize_cksum(struct mbuf *m, uint32_t hoff, uint32_t csum_flags) { unsigned char buf[15 << 2] __attribute__((aligned(8))); struct ip *ip; uint32_t offset, _hlen, mlen, hlen, len, sw_csum; uint16_t csum, ip_len; _CASSERT(sizeof(csum) == sizeof(uint16_t)); VERIFY(m->m_flags & M_PKTHDR); sw_csum = (csum_flags & m->m_pkthdr.csum_flags); if ((sw_csum &= (CSUM_DELAY_IP | CSUM_DELAY_DATA)) == 0) { goto done; } mlen = m->m_pkthdr.len; /* total mbuf len */ /* sanity check (need at least simple IP header) */ if (mlen < (hoff + sizeof(*ip))) { panic("%s: mbuf %p pkt len (%u) < hoff+ip_hdr " "(%u+%u)\n", __func__, m, mlen, hoff, (uint32_t)sizeof(*ip)); /* NOTREACHED */ } /* * In case the IP header is not contiguous, or not 32-bit aligned, * or if we're computing the IP header checksum, copy it to a local * buffer. Copy only the simple IP header here (IP options case * is handled below.) */ if ((sw_csum & CSUM_DELAY_IP) || (hoff + sizeof(*ip)) > m->m_len || !IP_HDR_ALIGNED_P(mtod(m, caddr_t) + hoff)) { m_copydata(m, hoff, sizeof(*ip), (caddr_t)buf); ip = (struct ip *)(void *)buf; _hlen = sizeof(*ip); } else { ip = (struct ip *)(void *)(m->m_data + hoff); _hlen = 0; } hlen = IP_VHL_HL(ip->ip_vhl) << 2; /* IP header len */ /* sanity check */ if (mlen < (hoff + hlen)) { panic("%s: mbuf %p pkt too short (%d) for IP header (%u), " "hoff %u", __func__, m, mlen, hlen, hoff); /* NOTREACHED */ } /* * 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, use the actual * packet length. This also covers the trailing bytes case. */ ip_len = ip->ip_len; if (ip_len != (mlen - hoff)) { ip_len = OSSwapInt16(ip_len); if (ip_len != (mlen - hoff)) { printf("%s: mbuf 0x%llx proto %d IP len %d (%x) " "[swapped %d (%x)] doesn't match actual packet " "length; %d is used instead\n", __func__, (uint64_t)VM_KERNEL_ADDRPERM(m), ip->ip_p, ip->ip_len, ip->ip_len, ip_len, ip_len, (mlen - hoff)); if (mlen - hoff > UINT16_MAX) { panic("%s: mlen %u - hoff %u > 65535", __func__, mlen, hoff); } ip_len = (uint16_t)(mlen - hoff); } } len = ip_len - hlen; /* csum span */ if (sw_csum & CSUM_DELAY_DATA) { uint16_t ulpoff; /* * offset is added to the lower 16-bit value of csum_data, * which is expected to contain the ULP offset; therefore * CSUM_PARTIAL offset adjustment must be undone. */ if ((m->m_pkthdr.csum_flags & (CSUM_PARTIAL | CSUM_DATA_VALID)) == (CSUM_PARTIAL | CSUM_DATA_VALID)) { /* * Get back the original ULP offset (this will * undo the CSUM_PARTIAL logic in ip_output.) */ m->m_pkthdr.csum_data = (m->m_pkthdr.csum_tx_stuff - m->m_pkthdr.csum_tx_start); } ulpoff = (m->m_pkthdr.csum_data & 0xffff); /* ULP csum offset */ offset = hoff + hlen; /* ULP header */ if (mlen < (ulpoff + sizeof(csum))) { panic("%s: mbuf %p pkt len (%u) proto %d invalid ULP " "cksum offset (%u) cksum flags 0x%x\n", __func__, m, mlen, ip->ip_p, ulpoff, m->m_pkthdr.csum_flags); /* NOTREACHED */ } csum = inet_cksum(m, 0, offset, len); /* Update stats */ ip_out_cksum_stats(ip->ip_p, len); /* RFC1122 4.1.3.4 */ if (csum == 0 && (m->m_pkthdr.csum_flags & (CSUM_UDP | CSUM_ZERO_INVERT))) { csum = 0xffff; } /* Insert the checksum in the ULP csum field */ offset += ulpoff; if (offset + sizeof(csum) > m->m_len) { m_copyback(m, offset, sizeof(csum), &csum); } else if (IP_HDR_ALIGNED_P(mtod(m, char *) + hoff)) { *(uint16_t *)(void *)(mtod(m, char *) + offset) = csum; } else { bcopy(&csum, (mtod(m, char *) + offset), sizeof(csum)); } m->m_pkthdr.csum_flags &= ~(CSUM_DELAY_DATA | CSUM_DATA_VALID | CSUM_PARTIAL | CSUM_ZERO_INVERT); } if (sw_csum & CSUM_DELAY_IP) { /* IP header must be in the local buffer */ VERIFY(_hlen == sizeof(*ip)); if (_hlen != hlen) { VERIFY(hlen <= sizeof(buf)); m_copydata(m, hoff, hlen, (caddr_t)buf); ip = (struct ip *)(void *)buf; _hlen = hlen; } /* * Compute the IP header checksum as if the IP length * is the length which we believe is "correct"; see * how ip_len gets calculated above. Note that this * is done on the local copy and not on the real one. */ ip->ip_len = htons(ip_len); ip->ip_sum = 0; csum = in_cksum_hdr_opt(ip); /* Update stats */ ipstat.ips_snd_swcsum++; ipstat.ips_snd_swcsum_bytes += hlen; /* * Insert only the checksum in the existing IP header * csum field; all other fields are left unchanged. */ offset = hoff + offsetof(struct ip, ip_sum); if (offset + sizeof(csum) > m->m_len) { m_copyback(m, offset, sizeof(csum), &csum); } else if (IP_HDR_ALIGNED_P(mtod(m, char *) + hoff)) { *(uint16_t *)(void *)(mtod(m, char *) + offset) = csum; } else { bcopy(&csum, (mtod(m, char *) + offset), sizeof(csum)); } m->m_pkthdr.csum_flags &= ~CSUM_DELAY_IP; } done: return sw_csum; } /* * 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(struct mbuf *m, struct mbuf *opt, int *phlen) { struct ipoption *p = mtod(opt, struct ipoption *); struct mbuf *n; 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_mtod_current(m) - optlen < m->m_pktdat) { MGETHDR(n, M_DONTWAIT, MT_HEADER); /* MAC-OK */ if (n == NULL) { return m; } n->m_pkthdr.rcvif = 0; 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. */ static int ip_optcopy(struct ip *ip, struct ip *jp) { 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"); /* NOTREACHED */ } #endif optlen = cp[IPOPT_OLEN]; #if DIAGNOSTIC if (optlen < IPOPT_OLEN + sizeof(*cp) || optlen > cnt) { panic("malformed IPv4 option passed to ip_optcopy"); /* NOTREACHED */ } #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 = (int)(dp - (u_char *)(jp + 1)); optlen & 0x3; optlen++) { *dp++ = IPOPT_EOL; } return optlen; } /* * IP socket option processing. */ int ip_ctloutput(struct socket *so, struct sockopt *sopt) { struct inpcb *inp = sotoinpcb(so); int error, optval; lck_mtx_t *mutex_held = NULL; error = optval = 0; if (sopt->sopt_level != IPPROTO_IP) { return EINVAL; } switch (sopt->sopt_dir) { case SOPT_SET: mutex_held = socket_getlock(so, PR_F_WILLUNLOCK); /* * Wait if we are in the middle of ip_output * as we unlocked the socket there and don't * want to overwrite the IP options */ if (inp->inp_sndinprog_cnt > 0) { inp->inp_sndingprog_waiters++; while (inp->inp_sndinprog_cnt > 0) { msleep(&inp->inp_sndinprog_cnt, mutex_held, PSOCK | PCATCH, "inp_sndinprog_cnt", NULL); } inp->inp_sndingprog_waiters--; } switch (sopt->sopt_name) { #ifdef notyet case IP_RETOPTS: #endif case IP_OPTIONS: { 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 == NULL) { error = ENOBUFS; break; } m->m_len = (int32_t)sopt->sopt_valsize; error = sooptcopyin(sopt, mtod(m, char *), m->m_len, m->m_len); if (error) { m_freem(m); 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: case IP_RECVTOS: case IP_DONTFRAG: error = sooptcopyin(sopt, &optval, sizeof(optval), sizeof(optval)); if (error) { break; } switch (sopt->sopt_name) { case IP_TOS: if (optval > UINT8_MAX) { error = EINVAL; break; } inp->inp_ip_tos = (uint8_t)optval; break; case IP_TTL: if (optval > UINT8_MAX) { error = EINVAL; break; } inp->inp_ip_ttl = (uint8_t)optval; break; #define OPTSET(bit) do { \ if (optval) { \ inp->inp_flags |= bit; \ } else { \ inp->inp_flags &= ~bit; \ } \ } while (0) #define OPTSET2(bit) do { \ if (optval) { \ inp->inp_flags2 |= bit; \ } else { \ inp->inp_flags2 &= ~bit; \ } \ } while (0) 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; case IP_RECVTOS: OPTSET(INP_RECVTOS); break; case IP_DONTFRAG: /* This option is settable only for IPv4 */ if (!(inp->inp_vflag & INP_IPV4)) { error = EINVAL; break; } OPTSET2(INP2_DONTFRAG); break; #undef OPTSET #undef OPTSET2 } break; /* * 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, NULL); 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; } /* once set, it cannot be unset */ if (!optval && INP_NO_CELLULAR(inp)) { error = EINVAL; break; } error = so_set_restrictions(so, SO_RESTRICT_DENY_CELLULAR); 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: case IP_RECVTOS: case IP_DONTFRAG: 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) #define OPTBIT2(bit) (inp->inp_flags2 & 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; case IP_RECVTOS: optval = OPTBIT(INP_RECVTOS); break; case IP_DONTFRAG: optval = OPTBIT2(INP2_DONTFRAG); 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: { error = 0; /* This option is no longer supported */ break; } #endif /* IPSEC */ #if TRAFFIC_MGT case IP_TRAFFIC_MGT_BACKGROUND: { unsigned background = (so->so_flags1 & SOF1_TRAFFIC_MGT_SO_BACKGROUND) ? 1 : 0; return sooptcopyout(sopt, &background, sizeof(background)); } #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_NO_CELLULAR(inp) ? 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(int optname, struct mbuf **pcbopt, struct mbuf *m) { #pragma unused(optname) int cnt, optlen; 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; } if (m->m_len % sizeof(int32_t)) { goto bad; } /* * IP first-hop destination address will be stored before * actual options; move other options back * and clear it when none present. */ if (m_mtod_upper_bound(m) - m_mtod_end(m) < sizeof(struct in_addr)) { 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; } if (optlen > UINT8_MAX) { goto bad; } m->m_len -= sizeof(struct in_addr); cnt -= sizeof(struct in_addr); optlen -= sizeof(struct in_addr); cp[IPOPT_OLEN] = (uint8_t)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 - (IPOPT_MINOFF - 1)); 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)); vm_size_t imo_size = (imo_debug == 0) ? sizeof(struct ip_moptions) : sizeof(struct ip_moptions_dbg); imo_zone = zone_create(IMO_ZONE_NAME, imo_size, ZC_ZFREE_CLEARMEM); } 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", __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) { 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; } IMO_PURGE_LOCKED(imo); IMO_UNLOCK(imo); kfree_type(struct in_multi *, imo->imo_max_memberships, imo->imo_membership); kfree_type(struct in_mfilter, imo->imo_max_memberships, imo->imo_mfilters); 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 = os_atomic_inc_orig(cnt, relaxed) % IMO_TRACE_HIST_SIZE; ctrace_record(&tr[idx]); } struct ip_moptions * ip_allocmoptions(zalloc_flags_t how) { struct ip_moptions *imo; imo = zalloc_flags(imo_zone, how | Z_ZERO); if (imo != NULL) { 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(struct ifnet *srcifp, struct ifnet *origifp, struct mbuf *m, struct sockaddr_in *dst, int hlen) { struct mbuf *copym; struct ip *ip; if (lo_ifp == NULL) { return; } /* * Copy the packet header as it's needed for the checksum * Make sure to deep-copy IP header portion in case the data * is in an mbuf cluster, so that we can safely override the IP * header portion later. */ copym = m_copym_mode(m, 0, M_COPYALL, M_DONTWAIT, NULL, NULL, M_COPYM_COPY_HDR); 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 = ip_cksum_hdr_out(copym, hlen); /* * Mark checksum as valid unless receive checksum offload is * disabled; if so, compute checksum in software. If the * interface itself is lo0, this will be overridden by if_loop. */ if (hwcksum_rx) { copym->m_pkthdr.csum_flags &= ~(CSUM_PARTIAL | CSUM_ZERO_INVERT); copym->m_pkthdr.csum_flags |= CSUM_DATA_VALID | CSUM_PSEUDO_HDR; copym->m_pkthdr.csum_data = 0xffff; } else if (copym->m_pkthdr.csum_flags & CSUM_DELAY_DATA) { #if BYTE_ORDER != BIG_ENDIAN NTOHS(ip->ip_len); #endif in_delayed_cksum(copym); #if BYTE_ORDER != BIG_ENDIAN HTONS(ip->ip_len); #endif } /* * 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. */ copym->m_pkthdr.rcvif = origifp; /* * Also record the source interface (which owns the source address). * This is basically a stripped down version of ifa_foraddr(). */ if (srcifp == NULL) { struct in_ifaddr *ia; lck_rw_lock_shared(&in_ifaddr_rwlock); TAILQ_FOREACH(ia, INADDR_HASH(ip->ip_src.s_addr), ia_hash) { IFA_LOCK_SPIN(&ia->ia_ifa); if (IA_SIN(ia)->sin_addr.s_addr == ip->ip_src.s_addr) { srcifp = ia->ia_ifp; IFA_UNLOCK(&ia->ia_ifa); break; } IFA_UNLOCK(&ia->ia_ifa); } lck_rw_done(&in_ifaddr_rwlock); } if (srcifp != NULL) { ip_setsrcifaddr_info(copym, srcifp->if_index, NULL); } ip_setdstifaddr_info(copym, origifp->if_index, NULL); dlil_output(lo_ifp, PF_INET, copym, NULL, SA(dst), 0, NULL); } /* * 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]; VERIFY(src.s_addr != INADDR_ANY); 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) && ROUTE_UNUSABLE(ro)) { 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; SOCKADDR_ZERO(&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, SA(&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); ROUTE_RELEASE(ro); /* * 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))) { if (ifa != NULL) { ifa_addref(ifa); /* for route */ } if (ro->ro_srcia != NULL) { ifa_remref(ro->ro_srcia); } ro->ro_srcia = ifa; ro->ro_flags |= ROF_SRCIF_SELECTED; RT_GENID_SYNC(ro->ro_rt); } if (ro->ro_rt != NULL) { RT_UNLOCK(ro->ro_rt); } return ifa; } /* * @brief Given outgoing interface it determines what checksum needs * to be computed in software and what needs to be offloaded to the * interface. * * @param ifp Pointer to the outgoing interface * @param m Pointer to the packet * @param hlen IP header length * @param ip_len Total packet size i.e. headers + data payload * @param sw_csum Pointer to a software checksum flag set * * @return void */ void ip_output_checksum(struct ifnet *ifp, struct mbuf *m, int hlen, int ip_len, uint32_t *sw_csum) { uint32_t hwcap = ifp->if_hwassist; m->m_pkthdr.csum_flags |= CSUM_IP; if (!hwcksum_tx) { /* do all in software; hardware checksum offload is disabled */ *sw_csum = (CSUM_DELAY_DATA | CSUM_DELAY_IP) & m->m_pkthdr.csum_flags; } else { /* do in software what the hardware cannot */ *sw_csum = m->m_pkthdr.csum_flags & ~IF_HWASSIST_CSUM_FLAGS(hwcap); } if (hlen != sizeof(struct ip)) { *sw_csum |= ((CSUM_DELAY_DATA | CSUM_DELAY_IP) & m->m_pkthdr.csum_flags); } else if ((*sw_csum & CSUM_DELAY_DATA) && (hwcap & CSUM_PARTIAL)) { /* * If the explicitly required data csum offload is not supported by hardware, * do it by partial checksum. Here we assume TSO implies support for IP * and data sum. */ int interface_mtu = ifp->if_mtu; if (INTF_ADJUST_MTU_FOR_CLAT46(ifp)) { interface_mtu = IN6_LINKMTU(ifp); /* Further adjust the size for CLAT46 expansion */ interface_mtu -= CLAT46_HDR_EXPANSION_OVERHD; } /* * Partial checksum offload, if non-IP fragment, and TCP only * (no UDP support, as the hardware may not be able to convert * +0 to -0 (0xffff) per RFC1122 4.1.3.4. unless the interface * supports "invert zero" capability.) */ if (hwcksum_tx && ((m->m_pkthdr.csum_flags & CSUM_TCP) || ((hwcap & CSUM_ZERO_INVERT) && (m->m_pkthdr.csum_flags & CSUM_ZERO_INVERT))) && ip_len <= interface_mtu) { uint16_t start = sizeof(struct ip); uint16_t ulpoff = m->m_pkthdr.csum_data & 0xffff; m->m_pkthdr.csum_flags |= (CSUM_DATA_VALID | CSUM_PARTIAL); m->m_pkthdr.csum_tx_stuff = (ulpoff + start); m->m_pkthdr.csum_tx_start = start; /* do IP hdr chksum in software */ *sw_csum = CSUM_DELAY_IP; } else { *sw_csum |= (CSUM_DELAY_DATA & m->m_pkthdr.csum_flags); } } if (*sw_csum & CSUM_DELAY_DATA) { in_delayed_cksum(m); *sw_csum &= ~CSUM_DELAY_DATA; } if (hwcksum_tx) { uint32_t delay_data = m->m_pkthdr.csum_flags & CSUM_DELAY_DATA; uint32_t hw_csum = IF_HWASSIST_CSUM_FLAGS(hwcap); /* * Drop off bits that aren't supported by hardware; * also make sure to preserve non-checksum related bits. */ m->m_pkthdr.csum_flags = ((m->m_pkthdr.csum_flags & (hw_csum | CSUM_DATA_VALID)) | (m->m_pkthdr.csum_flags & ~IF_HWASSIST_CSUM_MASK)); /* * If hardware supports partial checksum but not delay_data, * add back delay_data. */ if ((hw_csum & CSUM_PARTIAL) != 0 && (hw_csum & delay_data) == 0) { m->m_pkthdr.csum_flags |= delay_data; } } else { /* drop all bits; hardware checksum offload is disabled */ m->m_pkthdr.csum_flags = 0; } } /* * GRE protocol output for PPP/PPTP */ int ip_gre_output(struct mbuf *m) { struct route ro; int error; bzero(&ro, sizeof(ro)); error = ip_output(m, NULL, &ro, 0, NULL, NULL); ROUTE_RELEASE(&ro); return error; } static int sysctl_reset_ip_output_stats SYSCTL_HANDLER_ARGS { #pragma unused(arg1, arg2) int error, i; i = ip_output_measure; error = sysctl_handle_int(oidp, &i, 0, req); if (error || req->newptr == USER_ADDR_NULL) { goto done; } /* impose bounds */ if (i < 0 || i > 1) { error = EINVAL; goto done; } if (ip_output_measure != i && i == 1) { net_perf_initialize(&net_perf, ip_output_measure_bins); } ip_output_measure = i; done: return error; } static int sysctl_ip_output_measure_bins SYSCTL_HANDLER_ARGS { #pragma unused(arg1, arg2) int error; uint64_t i; i = ip_output_measure_bins; error = sysctl_handle_quad(oidp, &i, 0, req); if (error || req->newptr == USER_ADDR_NULL) { goto done; } /* validate data */ if (!net_perf_validate_bins(i)) { error = EINVAL; goto done; } ip_output_measure_bins = i; done: return error; } static int sysctl_ip_output_getperf SYSCTL_HANDLER_ARGS { #pragma unused(oidp, arg1, arg2) if (req->oldptr == USER_ADDR_NULL) { req->oldlen = (size_t)sizeof(struct ipstat); } return SYSCTL_OUT(req, &net_perf, MIN(sizeof(net_perf), req->oldlen)); }