ip_output.c revision 129126
11590Srgrimes/* 21590Srgrimes * Copyright (c) 1982, 1986, 1988, 1990, 1993 31590Srgrimes * The Regents of the University of California. All rights reserved. 41590Srgrimes * 51590Srgrimes * Redistribution and use in source and binary forms, with or without 61590Srgrimes * modification, are permitted provided that the following conditions 71590Srgrimes * are met: 81590Srgrimes * 1. Redistributions of source code must retain the above copyright 91590Srgrimes * notice, this list of conditions and the following disclaimer. 101590Srgrimes * 2. Redistributions in binary form must reproduce the above copyright 111590Srgrimes * notice, this list of conditions and the following disclaimer in the 121590Srgrimes * documentation and/or other materials provided with the distribution. 131590Srgrimes * 4. Neither the name of the University nor the names of its contributors 141590Srgrimes * may be used to endorse or promote products derived from this software 151590Srgrimes * without specific prior written permission. 161590Srgrimes * 171590Srgrimes * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 181590Srgrimes * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 191590Srgrimes * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 201590Srgrimes * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 211590Srgrimes * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 221590Srgrimes * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 231590Srgrimes * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 241590Srgrimes * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 251590Srgrimes * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 261590Srgrimes * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 271590Srgrimes * SUCH DAMAGE. 281590Srgrimes * 291590Srgrimes * @(#)ip_output.c 8.3 (Berkeley) 1/21/94 301590Srgrimes * $FreeBSD: head/sys/netinet/ip_output.c 129126 2004-05-11 19:14:44Z maxim $ 311590Srgrimes */ 321590Srgrimes 331590Srgrimes#include "opt_ipfw.h" 341590Srgrimes#include "opt_ipdn.h" 3528454Scharnier#include "opt_ipdivert.h" 361590Srgrimes#include "opt_ipfilter.h" 371590Srgrimes#include "opt_ipsec.h" 381590Srgrimes#include "opt_mac.h" 391590Srgrimes#include "opt_pfil_hooks.h" 401590Srgrimes#include "opt_random_ip_id.h" 4128454Scharnier#include "opt_mbuf_stress_test.h" 421590Srgrimes 4328454Scharnier#include <sys/param.h> 4428454Scharnier#include <sys/systm.h> 4550477Speter#include <sys/kernel.h> 461590Srgrimes#include <sys/mac.h> 471590Srgrimes#include <sys/malloc.h> 4828454Scharnier#include <sys/mbuf.h> 491590Srgrimes#include <sys/protosw.h> 5028454Scharnier#include <sys/socket.h> 5128454Scharnier#include <sys/socketvar.h> 5228454Scharnier#include <sys/sysctl.h> 5328454Scharnier 541590Srgrimes#include <net/if.h> 551590Srgrimes#include <net/route.h> 561590Srgrimes 571590Srgrimes#include <netinet/in.h> 581590Srgrimes#include <netinet/in_systm.h> 591590Srgrimes#include <netinet/ip.h> 601590Srgrimes#include <netinet/in_pcb.h> 611590Srgrimes#include <netinet/in_var.h> 621590Srgrimes#include <netinet/ip_var.h> 631590Srgrimes 641590Srgrimes#ifdef PFIL_HOOKS 651590Srgrimes#include <net/pfil.h> 661590Srgrimes#endif 671590Srgrimes 681590Srgrimes#include <machine/in_cksum.h> 691590Srgrimes 701590Srgrimesstatic MALLOC_DEFINE(M_IPMOPTS, "ip_moptions", "internet multicast options"); 711590Srgrimes 721590Srgrimes#ifdef IPSEC 731590Srgrimes#include <netinet6/ipsec.h> 741590Srgrimes#include <netkey/key.h> 751590Srgrimes#ifdef IPSEC_DEBUG 761590Srgrimes#include <netkey/key_debug.h> 771590Srgrimes#else 781590Srgrimes#define KEYDEBUG(lev,arg) 791590Srgrimes#endif 801590Srgrimes#endif /*IPSEC*/ 811590Srgrimes 821590Srgrimes#ifdef FAST_IPSEC 831590Srgrimes#include <netipsec/ipsec.h> 841590Srgrimes#include <netipsec/xform.h> 851590Srgrimes#include <netipsec/key.h> 861590Srgrimes#endif /*FAST_IPSEC*/ 8728454Scharnier 8828454Scharnier#include <netinet/ip_fw.h> 8928454Scharnier#include <netinet/ip_divert.h> 9028454Scharnier#include <netinet/ip_dummynet.h> 9128454Scharnier 9228454Scharnier#define print_ip(x, a, y) printf("%s %d.%d.%d.%d%s",\ 9328454Scharnier x, (ntohl(a.s_addr)>>24)&0xFF,\ 9428454Scharnier (ntohl(a.s_addr)>>16)&0xFF,\ 9528454Scharnier (ntohl(a.s_addr)>>8)&0xFF,\ 9628454Scharnier (ntohl(a.s_addr))&0xFF, y); 9728454Scharnier 9828454Scharnieru_short ip_id; 9928454Scharnier 1001590Srgrimes#ifdef MBUF_STRESS_TEST 1011590Srgrimesint mbuf_frag_size = 0; 10228789ScharnierSYSCTL_INT(_net_inet_ip, OID_AUTO, mbuf_frag_size, CTLFLAG_RW, 1031590Srgrimes &mbuf_frag_size, 0, "Fragment outgoing mbufs to this size"); 1041590Srgrimes#endif 1051590Srgrimes 1061590Srgrimesstatic struct mbuf *ip_insertoptions(struct mbuf *, struct mbuf *, int *); 1071590Srgrimesstatic struct ifnet *ip_multicast_if(struct in_addr *, int *); 1081590Srgrimesstatic void ip_mloopback 1091590Srgrimes (struct ifnet *, struct mbuf *, struct sockaddr_in *, int); 1101590Srgrimesstatic int ip_getmoptions 1111590Srgrimes (struct sockopt *, struct ip_moptions *); 1121590Srgrimesstatic int ip_pcbopts(int, struct mbuf **, struct mbuf *); 1131590Srgrimesstatic int ip_setmoptions 1141590Srgrimes (struct sockopt *, struct ip_moptions **); 11524360Simp 1161590Srgrimesint ip_optcopy(struct ip *, struct ip *); 1171590Srgrimes 1181590Srgrimes 1191590Srgrimesextern struct protosw inetsw[]; 1201590Srgrimes 1211590Srgrimes/* 1221590Srgrimes * IP output. The packet in mbuf chain m contains a skeletal IP 1231590Srgrimes * header (with len, off, ttl, proto, tos, src, dst). 1241590Srgrimes * The mbuf chain containing the packet will be freed. 1251590Srgrimes * The mbuf opt, if present, will not be freed. 12628454Scharnier * In the IP forwarding case, the packet will arrive with options already 1271590Srgrimes * inserted, so must have a NULL opt pointer. 1281590Srgrimes */ 1291590Srgrimesint 1301590Srgrimesip_output(struct mbuf *m, struct mbuf *opt, struct route *ro, 1311590Srgrimes int flags, struct ip_moptions *imo, struct inpcb *inp) 1321590Srgrimes{ 1331590Srgrimes struct ip *ip; 1341590Srgrimes struct ifnet *ifp = NULL; /* keep compiler happy */ 13528454Scharnier struct mbuf *m0; 1361590Srgrimes int hlen = sizeof (struct ip); 1371590Srgrimes int len, off, error = 0; 1381590Srgrimes struct sockaddr_in *dst = NULL; /* keep compiler happy */ 1391590Srgrimes struct in_ifaddr *ia = NULL; 1401590Srgrimes int isbroadcast, sw_csum; 1411590Srgrimes struct in_addr pkt_dst; 1421590Srgrimes struct route iproute; 1431590Srgrimes struct m_tag *mtag, *dummytag; 1441590Srgrimes#ifdef IPSEC 1451590Srgrimes struct secpolicy *sp = NULL; 1461590Srgrimes#endif 1471590Srgrimes#ifdef FAST_IPSEC 1481590Srgrimes struct secpolicy *sp = NULL; 1491590Srgrimes struct tdb_ident *tdbi; 1501590Srgrimes int s; 1511590Srgrimes#endif /* FAST_IPSEC */ 15228454Scharnier struct ip_fw_args args; 15328454Scharnier int src_was_INADDR_ANY = 0; /* as the name says... */ 15428454Scharnier 1551590Srgrimes args.eh = NULL; 1561590Srgrimes args.rule = NULL; 1571590Srgrimes 1581590Srgrimes M_ASSERTPKTHDR(m); 1591590Srgrimes 16028454Scharnier args.next_hop = m_claim_next(m, PACKET_TAG_IPFORWARD); 16128454Scharnier dummytag = m_tag_find(m, PACKET_TAG_DUMMYNET, NULL); 16228454Scharnier if (dummytag != NULL) { 16328454Scharnier struct dn_pkt_tag *dt = (struct dn_pkt_tag *)(dummytag+1); 16428454Scharnier /* 16528454Scharnier * Prevent lower layers from finding the tag 16628454Scharnier * Cleanup and free is done below 16728454Scharnier */ 1681590Srgrimes m_tag_unlink(m, dummytag); 1691590Srgrimes /* 1701590Srgrimes * the packet was already tagged, so part of the 1711590Srgrimes * processing was already done, and we need to go down. 1721590Srgrimes * Get parameters from the header. 1731590Srgrimes */ 1741590Srgrimes args.rule = dt->rule; 1751590Srgrimes ro = &(dt->ro); 1761590Srgrimes dst = dt->dn_dst; 1771590Srgrimes ifp = dt->ifp; 1781590Srgrimes } 1791590Srgrimes 1801590Srgrimes if (ro == NULL) { 1811590Srgrimes ro = &iproute; 1821590Srgrimes bzero(ro, sizeof (*ro)); 1831590Srgrimes } 1841590Srgrimes 1851590Srgrimes if (inp != NULL) 1861590Srgrimes INP_LOCK_ASSERT(inp); 1871590Srgrimes 1881590Srgrimes if (args.rule != NULL) { /* dummynet already saw us */ 1891590Srgrimes ip = mtod(m, struct ip *); 1901590Srgrimes hlen = ip->ip_hl << 2 ; 1911590Srgrimes if (ro->ro_rt) 1921590Srgrimes ia = ifatoia(ro->ro_rt->rt_ifa); 1931590Srgrimes goto sendit; 1941590Srgrimes } 1951590Srgrimes 1961590Srgrimes if (opt) { 1971590Srgrimes len = 0; 1981590Srgrimes m = ip_insertoptions(m, opt, &len); 1991590Srgrimes if (len != 0) 2001590Srgrimes hlen = len; 2011590Srgrimes } 2021590Srgrimes ip = mtod(m, struct ip *); 2031590Srgrimes pkt_dst = args.next_hop ? args.next_hop->sin_addr : ip->ip_dst; 2041590Srgrimes 2051590Srgrimes /* 2061590Srgrimes * Fill in IP header. If we are not allowing fragmentation, 2071590Srgrimes * then the ip_id field is meaningless, but we don't set it 2081590Srgrimes * to zero. Doing so causes various problems when devices along 2091590Srgrimes * the path (routers, load balancers, firewalls, etc.) illegally 2101590Srgrimes * disable DF on our packet. Note that a 16-bit counter 2111590Srgrimes * will wrap around in less than 10 seconds at 100 Mbit/s on a 2121590Srgrimes * medium with MTU 1500. See Steven M. Bellovin, "A Technique 2131590Srgrimes * for Counting NATted Hosts", Proc. IMW'02, available at 2141590Srgrimes * <http://www.research.att.com/~smb/papers/fnat.pdf>. 2151590Srgrimes */ 2161590Srgrimes if ((flags & (IP_FORWARDING|IP_RAWOUTPUT)) == 0) { 2171590Srgrimes ip->ip_v = IPVERSION; 2181590Srgrimes ip->ip_hl = hlen >> 2; 2191590Srgrimes#ifdef RANDOM_IP_ID 2201590Srgrimes ip->ip_id = ip_randomid(); 2211590Srgrimes#else 2221590Srgrimes ip->ip_id = htons(ip_id++); 2231590Srgrimes#endif 2241590Srgrimes ipstat.ips_localout++; 2251590Srgrimes } else { 2261590Srgrimes hlen = ip->ip_hl << 2; 2271590Srgrimes } 2281590Srgrimes 2291590Srgrimes dst = (struct sockaddr_in *)&ro->ro_dst; 2301590Srgrimes /* 2311590Srgrimes * If there is a cached route, 23228454Scharnier * check that it is to the same destination 2331590Srgrimes * and is still up. If not, free it and try again. 2341590Srgrimes * The address family should also be checked in case of sharing the 2351590Srgrimes * cache with IPv6. 2361590Srgrimes */ 2371590Srgrimes if (ro->ro_rt && ((ro->ro_rt->rt_flags & RTF_UP) == 0 || 2381590Srgrimes dst->sin_family != AF_INET || 2391590Srgrimes dst->sin_addr.s_addr != pkt_dst.s_addr)) { 2401590Srgrimes RTFREE(ro->ro_rt); 2411590Srgrimes ro->ro_rt = (struct rtentry *)0; 2421590Srgrimes } 2431590Srgrimes if (ro->ro_rt == 0) { 2441590Srgrimes bzero(dst, sizeof(*dst)); 2451590Srgrimes dst->sin_family = AF_INET; 2461590Srgrimes dst->sin_len = sizeof(*dst); 2471590Srgrimes dst->sin_addr = pkt_dst; 2481590Srgrimes } 2491590Srgrimes /* 2501590Srgrimes * If routing to interface only, 2511590Srgrimes * short circuit routing lookup. 2521590Srgrimes */ 2531590Srgrimes if (flags & IP_ROUTETOIF) { 2541590Srgrimes if ((ia = ifatoia(ifa_ifwithdstaddr(sintosa(dst)))) == 0 && 2551590Srgrimes (ia = ifatoia(ifa_ifwithnet(sintosa(dst)))) == 0) { 2561590Srgrimes ipstat.ips_noroute++; 2571590Srgrimes error = ENETUNREACH; 2581590Srgrimes goto bad; 2591590Srgrimes } 2601590Srgrimes ifp = ia->ia_ifp; 2611590Srgrimes ip->ip_ttl = 1; 2621590Srgrimes isbroadcast = in_broadcast(dst->sin_addr, ifp); 2631590Srgrimes } else if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr)) && 2641590Srgrimes imo != NULL && imo->imo_multicast_ifp != NULL) { 2651590Srgrimes /* 2661590Srgrimes * Bypass the normal routing lookup for multicast 2671590Srgrimes * packets if the interface is specified. 2681590Srgrimes */ 2691590Srgrimes ifp = imo->imo_multicast_ifp; 2701590Srgrimes IFP_TO_IA(ifp, ia); 2711590Srgrimes isbroadcast = 0; /* fool gcc */ 2721590Srgrimes } else { 2731590Srgrimes /* 2741590Srgrimes * We want to do any cloning requested by the link layer, 2751590Srgrimes * as this is probably required in all cases for correct 2761590Srgrimes * operation (as it is for ARP). 2771590Srgrimes */ 27828454Scharnier if (ro->ro_rt == 0) 2791590Srgrimes rtalloc_ign(ro, 0); 2801590Srgrimes if (ro->ro_rt == 0) { 2811590Srgrimes ipstat.ips_noroute++; 2821590Srgrimes error = EHOSTUNREACH; 2831590Srgrimes goto bad; 2841590Srgrimes } 2851590Srgrimes ia = ifatoia(ro->ro_rt->rt_ifa); 2861590Srgrimes ifp = ro->ro_rt->rt_ifp; 2871590Srgrimes ro->ro_rt->rt_rmx.rmx_pksent++; 2881590Srgrimes if (ro->ro_rt->rt_flags & RTF_GATEWAY) 28928454Scharnier dst = (struct sockaddr_in *)ro->ro_rt->rt_gateway; 2901590Srgrimes if (ro->ro_rt->rt_flags & RTF_HOST) 2911590Srgrimes isbroadcast = (ro->ro_rt->rt_flags & RTF_BROADCAST); 2921590Srgrimes else 2931590Srgrimes isbroadcast = in_broadcast(dst->sin_addr, ifp); 2941590Srgrimes } 2951590Srgrimes if (IN_MULTICAST(ntohl(pkt_dst.s_addr))) { 2961590Srgrimes struct in_multi *inm; 2971590Srgrimes 2981590Srgrimes m->m_flags |= M_MCAST; 2991590Srgrimes /* 3001590Srgrimes * IP destination address is multicast. Make sure "dst" 30128454Scharnier * still points to the address in "ro". (It may have been 3021590Srgrimes * changed to point to a gateway address, above.) 3031590Srgrimes */ 3041590Srgrimes dst = (struct sockaddr_in *)&ro->ro_dst; 3051590Srgrimes /* 3061590Srgrimes * See if the caller provided any multicast options 3071590Srgrimes */ 3081590Srgrimes if (imo != NULL) { 3091590Srgrimes ip->ip_ttl = imo->imo_multicast_ttl; 3101590Srgrimes if (imo->imo_multicast_vif != -1) 3111590Srgrimes ip->ip_src.s_addr = 3121590Srgrimes ip_mcast_src ? 3131590Srgrimes ip_mcast_src(imo->imo_multicast_vif) : 3141590Srgrimes INADDR_ANY; 3151590Srgrimes } else 3161590Srgrimes ip->ip_ttl = IP_DEFAULT_MULTICAST_TTL; 3171590Srgrimes /* 31828454Scharnier * Confirm that the outgoing interface supports multicast. 3191590Srgrimes */ 3201590Srgrimes if ((imo == NULL) || (imo->imo_multicast_vif == -1)) { 3211590Srgrimes if ((ifp->if_flags & IFF_MULTICAST) == 0) { 3221590Srgrimes ipstat.ips_noroute++; 3231590Srgrimes error = ENETUNREACH; 3241590Srgrimes goto bad; 3251590Srgrimes } 3261590Srgrimes } 3271590Srgrimes /* 3281590Srgrimes * If source address not specified yet, use address 3291590Srgrimes * of outgoing interface. 3301590Srgrimes */ 3311590Srgrimes if (ip->ip_src.s_addr == INADDR_ANY) { 3321590Srgrimes /* Interface may have no addresses. */ 3331590Srgrimes if (ia != NULL) 3341590Srgrimes ip->ip_src = IA_SIN(ia)->sin_addr; 3351590Srgrimes } 3361590Srgrimes 3371590Srgrimes IN_LOOKUP_MULTI(pkt_dst, ifp, inm); 3381590Srgrimes if (inm != NULL && 3391590Srgrimes (imo == NULL || imo->imo_multicast_loop)) { 3401590Srgrimes /* 3411590Srgrimes * If we belong to the destination multicast group 3421590Srgrimes * on the outgoing interface, and the caller did not 3431590Srgrimes * forbid loopback, loop back a copy. 3441590Srgrimes */ 3451590Srgrimes ip_mloopback(ifp, m, dst, hlen); 3461590Srgrimes } 3471590Srgrimes else { 3481590Srgrimes /* 3491590Srgrimes * If we are acting as a multicast router, perform 3501590Srgrimes * multicast forwarding as if the packet had just 3511590Srgrimes * arrived on the interface to which we are about 3521590Srgrimes * to send. The multicast forwarding function 3531590Srgrimes * recursively calls this function, using the 3541590Srgrimes * IP_FORWARDING flag to prevent infinite recursion. 3551590Srgrimes * 35628454Scharnier * Multicasts that are looped back by ip_mloopback(), 3571590Srgrimes * above, will be forwarded by the ip_input() routine, 3581590Srgrimes * if necessary. 3591590Srgrimes */ 3601590Srgrimes if (ip_mrouter && (flags & IP_FORWARDING) == 0) { 3611590Srgrimes /* 3621590Srgrimes * If rsvp daemon is not running, do not 3631590Srgrimes * set ip_moptions. This ensures that the packet 3641590Srgrimes * is multicast and not just sent down one link 3651590Srgrimes * as prescribed by rsvpd. 3661590Srgrimes */ 3671590Srgrimes if (!rsvp_on) 3681590Srgrimes imo = NULL; 3691590Srgrimes if (ip_mforward && 3701590Srgrimes ip_mforward(ip, ifp, m, imo) != 0) { 3711590Srgrimes m_freem(m); 3721590Srgrimes goto done; 3731590Srgrimes } 3741590Srgrimes } 3751590Srgrimes } 3761590Srgrimes 3771590Srgrimes /* 3781590Srgrimes * Multicasts with a time-to-live of zero may be looped- 3791590Srgrimes * back, above, but must not be transmitted on a network. 38028454Scharnier * Also, multicasts addressed to the loopback interface 3811590Srgrimes * are not sent -- the above call to ip_mloopback() will 3821590Srgrimes * loop back a copy if this host actually belongs to the 3831590Srgrimes * destination group on the loopback interface. 3841590Srgrimes */ 3851590Srgrimes if (ip->ip_ttl == 0 || ifp->if_flags & IFF_LOOPBACK) { 3861590Srgrimes m_freem(m); 3871590Srgrimes goto done; 3881590Srgrimes } 3891590Srgrimes 39028454Scharnier goto sendit; 3911590Srgrimes } 3921590Srgrimes#ifndef notdef 3931590Srgrimes /* 3941590Srgrimes * If the source address is not specified yet, use the address 3951590Srgrimes * of the outoing interface. In case, keep note we did that, so 3961590Srgrimes * if the the firewall changes the next-hop causing the output 3971590Srgrimes * interface to change, we can fix that. 3981590Srgrimes */ 3991590Srgrimes if (ip->ip_src.s_addr == INADDR_ANY) { 4001590Srgrimes /* Interface may have no addresses. */ 4011590Srgrimes if (ia != NULL) { 40228454Scharnier ip->ip_src = IA_SIN(ia)->sin_addr; 4031590Srgrimes src_was_INADDR_ANY = 1; 4041590Srgrimes } 4051590Srgrimes } 4061590Srgrimes#endif /* notdef */ 4071590Srgrimes /* 4081590Srgrimes * Verify that we have any chance at all of being able to queue 4091590Srgrimes * the packet or packet fragments 4101590Srgrimes */ 4111590Srgrimes if ((ifp->if_snd.ifq_len + ip->ip_len / ifp->if_mtu + 1) >= 41228454Scharnier ifp->if_snd.ifq_maxlen) { 4131590Srgrimes error = ENOBUFS; 4141590Srgrimes ipstat.ips_odropped++; 4151590Srgrimes goto bad; 4161590Srgrimes } 4171590Srgrimes 4181590Srgrimes /* 4191590Srgrimes * Look for broadcast address and 4201590Srgrimes * verify user is allowed to send 4211590Srgrimes * such a packet. 4221590Srgrimes */ 4231590Srgrimes if (isbroadcast) { 4241590Srgrimes if ((ifp->if_flags & IFF_BROADCAST) == 0) { 4251590Srgrimes error = EADDRNOTAVAIL; 4261590Srgrimes goto bad; 4271590Srgrimes } 4281590Srgrimes if ((flags & IP_ALLOWBROADCAST) == 0) { 4291590Srgrimes error = EACCES; 4301590Srgrimes goto bad; 4311590Srgrimes } 4321590Srgrimes /* don't allow broadcast messages to be fragmented */ 4331590Srgrimes if (ip->ip_len > ifp->if_mtu) { 4341590Srgrimes error = EMSGSIZE; 4351590Srgrimes goto bad; 4361590Srgrimes } 4371590Srgrimes if (flags & IP_SENDONES) 4381590Srgrimes ip->ip_dst.s_addr = INADDR_BROADCAST; 4391590Srgrimes m->m_flags |= M_BCAST; 4401590Srgrimes } else { 4411590Srgrimes m->m_flags &= ~M_BCAST; 4421590Srgrimes } 4431590Srgrimes 4441590Srgrimessendit: 4451590Srgrimes#ifdef IPSEC 4461590Srgrimes /* get SP for this packet */ 4471590Srgrimes if (inp == NULL) 4481590Srgrimes sp = ipsec4_getpolicybyaddr(m, IPSEC_DIR_OUTBOUND, 4491590Srgrimes flags, &error); 4501590Srgrimes else 4511590Srgrimes sp = ipsec4_getpolicybypcb(m, IPSEC_DIR_OUTBOUND, inp, &error); 4528874Srgrimes 4531590Srgrimes if (sp == NULL) { 4541590Srgrimes ipsecstat.out_inval++; 4551590Srgrimes goto bad; 4561590Srgrimes } 4571590Srgrimes 4581590Srgrimes error = 0; 4591590Srgrimes 4601590Srgrimes /* check policy */ 4611590Srgrimes switch (sp->policy) { 4621590Srgrimes case IPSEC_POLICY_DISCARD: 4631590Srgrimes /* 4641590Srgrimes * This packet is just discarded. 46528454Scharnier */ 4661590Srgrimes ipsecstat.out_polvio++; 4671590Srgrimes goto bad; 4681590Srgrimes 46928454Scharnier case IPSEC_POLICY_BYPASS: 4701590Srgrimes case IPSEC_POLICY_NONE: 4711590Srgrimes case IPSEC_POLICY_TCP: 4721590Srgrimes /* no need to do IPsec. */ 4731590Srgrimes goto skip_ipsec; 47428454Scharnier 4751590Srgrimes case IPSEC_POLICY_IPSEC: 4761590Srgrimes if (sp->req == NULL) { 4771590Srgrimes /* acquire a policy */ 4781590Srgrimes error = key_spdacquire(sp); 4791590Srgrimes goto bad; 4801590Srgrimes } 4811590Srgrimes break; 4821590Srgrimes 4831590Srgrimes case IPSEC_POLICY_ENTRUST: 4841590Srgrimes default: 48528454Scharnier printf("ip_output: Invalid policy found. %d\n", sp->policy); 48628454Scharnier } 4871590Srgrimes { 4881590Srgrimes struct ipsec_output_state state; 4891590Srgrimes bzero(&state, sizeof(state)); 4901590Srgrimes state.m = m; 49128454Scharnier if (flags & IP_ROUTETOIF) { 4921590Srgrimes state.ro = &iproute; 4931590Srgrimes bzero(&iproute, sizeof(iproute)); 4941590Srgrimes } else 4951590Srgrimes state.ro = ro; 4961590Srgrimes state.dst = (struct sockaddr *)dst; 4971590Srgrimes 4981590Srgrimes ip->ip_sum = 0; 4991590Srgrimes 5001590Srgrimes /* 5011590Srgrimes * XXX 5021590Srgrimes * delayed checksums are not currently compatible with IPsec 5031590Srgrimes */ 5041590Srgrimes if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) { 5051590Srgrimes in_delayed_cksum(m); 5061590Srgrimes m->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA; 5071590Srgrimes } 5081590Srgrimes 5091590Srgrimes ip->ip_len = htons(ip->ip_len); 5101590Srgrimes ip->ip_off = htons(ip->ip_off); 5111590Srgrimes 5121590Srgrimes error = ipsec4_output(&state, sp, flags); 5131590Srgrimes 5141590Srgrimes m = state.m; 5151590Srgrimes if (flags & IP_ROUTETOIF) { 5161590Srgrimes /* 5171590Srgrimes * if we have tunnel mode SA, we may need to ignore 5181590Srgrimes * IP_ROUTETOIF. 5191590Srgrimes */ 5201590Srgrimes if (state.ro != &iproute || state.ro->ro_rt != NULL) { 5211590Srgrimes flags &= ~IP_ROUTETOIF; 5221590Srgrimes ro = state.ro; 5231590Srgrimes } 5241590Srgrimes } else 5251590Srgrimes ro = state.ro; 5261590Srgrimes dst = (struct sockaddr_in *)state.dst; 5271590Srgrimes if (error) { 5281590Srgrimes /* mbuf is already reclaimed in ipsec4_output. */ 5291590Srgrimes m = NULL; 5301590Srgrimes switch (error) { 5311590Srgrimes case EHOSTUNREACH: 5321590Srgrimes case ENETUNREACH: 5331590Srgrimes case EMSGSIZE: 5341590Srgrimes case ENOBUFS: 5351590Srgrimes case ENOMEM: 5361590Srgrimes break; 537 default: 538 printf("ip4_output (ipsec): error code %d\n", error); 539 /*fall through*/ 540 case ENOENT: 541 /* don't show these error codes to the user */ 542 error = 0; 543 break; 544 } 545 goto bad; 546 } 547 548 /* be sure to update variables that are affected by ipsec4_output() */ 549 ip = mtod(m, struct ip *); 550 hlen = ip->ip_hl << 2; 551 if (ro->ro_rt == NULL) { 552 if ((flags & IP_ROUTETOIF) == 0) { 553 printf("ip_output: " 554 "can't update route after IPsec processing\n"); 555 error = EHOSTUNREACH; /*XXX*/ 556 goto bad; 557 } 558 } else { 559 if (state.encap) { 560 ia = ifatoia(ro->ro_rt->rt_ifa); 561 ifp = ro->ro_rt->rt_ifp; 562 } 563 } 564 } 565 566 /* make it flipped, again. */ 567 ip->ip_len = ntohs(ip->ip_len); 568 ip->ip_off = ntohs(ip->ip_off); 569skip_ipsec: 570#endif /*IPSEC*/ 571#ifdef FAST_IPSEC 572 /* 573 * Check the security policy (SP) for the packet and, if 574 * required, do IPsec-related processing. There are two 575 * cases here; the first time a packet is sent through 576 * it will be untagged and handled by ipsec4_checkpolicy. 577 * If the packet is resubmitted to ip_output (e.g. after 578 * AH, ESP, etc. processing), there will be a tag to bypass 579 * the lookup and related policy checking. 580 */ 581 mtag = m_tag_find(m, PACKET_TAG_IPSEC_PENDING_TDB, NULL); 582 s = splnet(); 583 if (mtag != NULL) { 584 tdbi = (struct tdb_ident *)(mtag + 1); 585 sp = ipsec_getpolicy(tdbi, IPSEC_DIR_OUTBOUND); 586 if (sp == NULL) 587 error = -EINVAL; /* force silent drop */ 588 m_tag_delete(m, mtag); 589 } else { 590 sp = ipsec4_checkpolicy(m, IPSEC_DIR_OUTBOUND, flags, 591 &error, inp); 592 } 593 /* 594 * There are four return cases: 595 * sp != NULL apply IPsec policy 596 * sp == NULL, error == 0 no IPsec handling needed 597 * sp == NULL, error == -EINVAL discard packet w/o error 598 * sp == NULL, error != 0 discard packet, report error 599 */ 600 if (sp != NULL) { 601 /* Loop detection, check if ipsec processing already done */ 602 KASSERT(sp->req != NULL, ("ip_output: no ipsec request")); 603 for (mtag = m_tag_first(m); mtag != NULL; 604 mtag = m_tag_next(m, mtag)) { 605 if (mtag->m_tag_cookie != MTAG_ABI_COMPAT) 606 continue; 607 if (mtag->m_tag_id != PACKET_TAG_IPSEC_OUT_DONE && 608 mtag->m_tag_id != PACKET_TAG_IPSEC_OUT_CRYPTO_NEEDED) 609 continue; 610 /* 611 * Check if policy has an SA associated with it. 612 * This can happen when an SP has yet to acquire 613 * an SA; e.g. on first reference. If it occurs, 614 * then we let ipsec4_process_packet do its thing. 615 */ 616 if (sp->req->sav == NULL) 617 break; 618 tdbi = (struct tdb_ident *)(mtag + 1); 619 if (tdbi->spi == sp->req->sav->spi && 620 tdbi->proto == sp->req->sav->sah->saidx.proto && 621 bcmp(&tdbi->dst, &sp->req->sav->sah->saidx.dst, 622 sizeof (union sockaddr_union)) == 0) { 623 /* 624 * No IPsec processing is needed, free 625 * reference to SP. 626 * 627 * NB: null pointer to avoid free at 628 * done: below. 629 */ 630 KEY_FREESP(&sp), sp = NULL; 631 splx(s); 632 goto spd_done; 633 } 634 } 635 636 /* 637 * Do delayed checksums now because we send before 638 * this is done in the normal processing path. 639 */ 640 if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) { 641 in_delayed_cksum(m); 642 m->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA; 643 } 644 645 ip->ip_len = htons(ip->ip_len); 646 ip->ip_off = htons(ip->ip_off); 647 648 /* NB: callee frees mbuf */ 649 error = ipsec4_process_packet(m, sp->req, flags, 0); 650 /* 651 * Preserve KAME behaviour: ENOENT can be returned 652 * when an SA acquire is in progress. Don't propagate 653 * this to user-level; it confuses applications. 654 * 655 * XXX this will go away when the SADB is redone. 656 */ 657 if (error == ENOENT) 658 error = 0; 659 splx(s); 660 goto done; 661 } else { 662 splx(s); 663 664 if (error != 0) { 665 /* 666 * Hack: -EINVAL is used to signal that a packet 667 * should be silently discarded. This is typically 668 * because we asked key management for an SA and 669 * it was delayed (e.g. kicked up to IKE). 670 */ 671 if (error == -EINVAL) 672 error = 0; 673 goto bad; 674 } else { 675 /* No IPsec processing for this packet. */ 676 } 677#ifdef notyet 678 /* 679 * If deferred crypto processing is needed, check that 680 * the interface supports it. 681 */ 682 mtag = m_tag_find(m, PACKET_TAG_IPSEC_OUT_CRYPTO_NEEDED, NULL); 683 if (mtag != NULL && (ifp->if_capenable & IFCAP_IPSEC) == 0) { 684 /* notify IPsec to do its own crypto */ 685 ipsp_skipcrypto_unmark((struct tdb_ident *)(mtag + 1)); 686 error = EHOSTUNREACH; 687 goto bad; 688 } 689#endif 690 } 691spd_done: 692#endif /* FAST_IPSEC */ 693 694 /* 695 * IpHack's section. 696 * - Xlate: translate packet's addr/port (NAT). 697 * - Firewall: deny/allow/etc. 698 * - Wrap: fake packet's addr/port <unimpl.> 699 * - Encapsulate: put it in another IP and send out. <unimp.> 700 */ 701#ifdef PFIL_HOOKS 702 /* 703 * Run through list of hooks for output packets. 704 */ 705 error = pfil_run_hooks(&inet_pfil_hook, &m, ifp, PFIL_OUT); 706 if (error != 0 || m == NULL) 707 goto done; 708 ip = mtod(m, struct ip *); 709#endif /* PFIL_HOOKS */ 710 711 /* 712 * Check with the firewall... 713 * but not if we are already being fwd'd from a firewall. 714 */ 715 if (fw_enable && IPFW_LOADED && !args.next_hop) { 716 struct sockaddr_in *old = dst; 717 718 args.m = m; 719 args.next_hop = dst; 720 args.oif = ifp; 721 off = ip_fw_chk_ptr(&args); 722 m = args.m; 723 dst = args.next_hop; 724 725 /* 726 * On return we must do the following: 727 * m == NULL -> drop the pkt (old interface, deprecated) 728 * (off & IP_FW_PORT_DENY_FLAG) -> drop the pkt (new interface) 729 * 1<=off<= 0xffff -> DIVERT 730 * (off & IP_FW_PORT_DYNT_FLAG) -> send to a DUMMYNET pipe 731 * (off & IP_FW_PORT_TEE_FLAG) -> TEE the packet 732 * dst != old -> IPFIREWALL_FORWARD 733 * off==0, dst==old -> accept 734 * If some of the above modules are not compiled in, then 735 * we should't have to check the corresponding condition 736 * (because the ipfw control socket should not accept 737 * unsupported rules), but better play safe and drop 738 * packets in case of doubt. 739 */ 740 if ( (off & IP_FW_PORT_DENY_FLAG) || m == NULL) { 741 if (m) 742 m_freem(m); 743 error = EACCES; 744 goto done; 745 } 746 ip = mtod(m, struct ip *); 747 if (off == 0 && dst == old) /* common case */ 748 goto pass; 749 if (DUMMYNET_LOADED && (off & IP_FW_PORT_DYNT_FLAG) != 0) { 750 /* 751 * pass the pkt to dummynet. Need to include 752 * pipe number, m, ifp, ro, dst because these are 753 * not recomputed in the next pass. 754 * All other parameters have been already used and 755 * so they are not needed anymore. 756 * XXX note: if the ifp or ro entry are deleted 757 * while a pkt is in dummynet, we are in trouble! 758 */ 759 args.ro = ro; 760 args.dst = dst; 761 args.flags = flags; 762 763 error = ip_dn_io_ptr(m, off & 0xffff, DN_TO_IP_OUT, 764 &args); 765 goto done; 766 } 767#ifdef IPDIVERT 768 if (off != 0 && (off & IP_FW_PORT_DYNT_FLAG) == 0) { 769 struct mbuf *clone; 770 771 /* Clone packet if we're doing a 'tee' */ 772 if ((off & IP_FW_PORT_TEE_FLAG) != 0) 773 clone = divert_clone(m); 774 else 775 clone = NULL; 776 777 /* 778 * XXX 779 * delayed checksums are not currently compatible 780 * with divert sockets. 781 */ 782 if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) { 783 in_delayed_cksum(m); 784 m->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA; 785 } 786 787 /* Restore packet header fields to original values */ 788 ip->ip_len = htons(ip->ip_len); 789 ip->ip_off = htons(ip->ip_off); 790 791 /* Deliver packet to divert input routine */ 792 divert_packet(m, 0); 793 794 /* If 'tee', continue with original packet */ 795 if (clone != NULL) { 796 m = clone; 797 ip = mtod(m, struct ip *); 798 goto pass; 799 } 800 goto done; 801 } 802#endif 803 804 /* IPFIREWALL_FORWARD */ 805 /* 806 * Check dst to make sure it is directly reachable on the 807 * interface we previously thought it was. 808 * If it isn't (which may be likely in some situations) we have 809 * to re-route it (ie, find a route for the next-hop and the 810 * associated interface) and set them here. This is nested 811 * forwarding which in most cases is undesirable, except where 812 * such control is nigh impossible. So we do it here. 813 * And I'm babbling. 814 */ 815 if (off == 0 && old != dst) { /* FORWARD, dst has changed */ 816#if 0 817 /* 818 * XXX To improve readability, this block should be 819 * changed into a function call as below: 820 */ 821 error = ip_ipforward(&m, &dst, &ifp); 822 if (error) 823 goto bad; 824 if (m == NULL) /* ip_input consumed the mbuf */ 825 goto done; 826#else 827 struct in_ifaddr *ia; 828 829 /* 830 * XXX sro_fwd below is static, and a pointer 831 * to it gets passed to routines downstream. 832 * This could have surprisingly bad results in 833 * practice, because its content is overwritten 834 * by subsequent packets. 835 */ 836 /* There must be a better way to do this next line... */ 837 static struct route sro_fwd; 838 struct route *ro_fwd = &sro_fwd; 839 840#if 0 841 print_ip("IPFIREWALL_FORWARD: New dst ip: ", 842 dst->sin_addr, "\n"); 843#endif 844 845 /* 846 * We need to figure out if we have been forwarded 847 * to a local socket. If so, then we should somehow 848 * "loop back" to ip_input, and get directed to the 849 * PCB as if we had received this packet. This is 850 * because it may be dificult to identify the packets 851 * you want to forward until they are being output 852 * and have selected an interface. (e.g. locally 853 * initiated packets) If we used the loopback inteface, 854 * we would not be able to control what happens 855 * as the packet runs through ip_input() as 856 * it is done through an ISR. 857 */ 858 LIST_FOREACH(ia, 859 INADDR_HASH(dst->sin_addr.s_addr), ia_hash) { 860 /* 861 * If the addr to forward to is one 862 * of ours, we pretend to 863 * be the destination for this packet. 864 */ 865 if (IA_SIN(ia)->sin_addr.s_addr == 866 dst->sin_addr.s_addr) 867 break; 868 } 869 if (ia) { /* tell ip_input "dont filter" */ 870 mtag = m_tag_get( 871 PACKET_TAG_IPFORWARD, 872 sizeof(struct sockaddr_in *), M_NOWAIT); 873 if (mtag == NULL) { 874 error = ENOBUFS; 875 goto bad; 876 } 877 *(struct sockaddr_in **)(mtag+1) = 878 args.next_hop; 879 m_tag_prepend(m, mtag); 880 881 if (m->m_pkthdr.rcvif == NULL) 882 m->m_pkthdr.rcvif = ifunit("lo0"); 883 if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) { 884 m->m_pkthdr.csum_flags |= 885 CSUM_DATA_VALID | CSUM_PSEUDO_HDR; 886 m->m_pkthdr.csum_data = 0xffff; 887 } 888 m->m_pkthdr.csum_flags |= 889 CSUM_IP_CHECKED | CSUM_IP_VALID; 890 ip->ip_len = htons(ip->ip_len); 891 ip->ip_off = htons(ip->ip_off); 892 ip_input(m); 893 goto done; 894 } 895 /* 896 * Some of the logic for this was 897 * nicked from above. 898 */ 899 bcopy(dst, &ro_fwd->ro_dst, sizeof(*dst)); 900 901 ro_fwd->ro_rt = 0; 902 rtalloc_ign(ro_fwd, RTF_CLONING); 903 904 if (ro_fwd->ro_rt == 0) { 905 ipstat.ips_noroute++; 906 error = EHOSTUNREACH; 907 goto bad; 908 } 909 910 ia = ifatoia(ro_fwd->ro_rt->rt_ifa); 911 ifp = ro_fwd->ro_rt->rt_ifp; 912 ro_fwd->ro_rt->rt_rmx.rmx_pksent++; 913 if (ro_fwd->ro_rt->rt_flags & RTF_GATEWAY) 914 dst = (struct sockaddr_in *) 915 ro_fwd->ro_rt->rt_gateway; 916 if (ro_fwd->ro_rt->rt_flags & RTF_HOST) 917 isbroadcast = 918 (ro_fwd->ro_rt->rt_flags & RTF_BROADCAST); 919 else 920 isbroadcast = in_broadcast(dst->sin_addr, ifp); 921 if (ro->ro_rt) 922 RTFREE(ro->ro_rt); 923 ro->ro_rt = ro_fwd->ro_rt; 924 dst = (struct sockaddr_in *)&ro_fwd->ro_dst; 925 926#endif /* ... block to be put into a function */ 927 /* 928 * If we added a default src ip earlier, 929 * which would have been gotten from the-then 930 * interface, do it again, from the new one. 931 */ 932 if (src_was_INADDR_ANY) 933 ip->ip_src = IA_SIN(ia)->sin_addr; 934 goto pass ; 935 } 936 937 /* 938 * if we get here, none of the above matches, and 939 * we have to drop the pkt 940 */ 941 m_freem(m); 942 error = EACCES; /* not sure this is the right error msg */ 943 goto done; 944 } 945 946pass: 947 /* 127/8 must not appear on wire - RFC1122. */ 948 if ((ntohl(ip->ip_dst.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET || 949 (ntohl(ip->ip_src.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET) { 950 if ((ifp->if_flags & IFF_LOOPBACK) == 0) { 951 ipstat.ips_badaddr++; 952 error = EADDRNOTAVAIL; 953 goto bad; 954 } 955 } 956 957 m->m_pkthdr.csum_flags |= CSUM_IP; 958 sw_csum = m->m_pkthdr.csum_flags & ~ifp->if_hwassist; 959 if (sw_csum & CSUM_DELAY_DATA) { 960 in_delayed_cksum(m); 961 sw_csum &= ~CSUM_DELAY_DATA; 962 } 963 m->m_pkthdr.csum_flags &= ifp->if_hwassist; 964 965 /* 966 * If small enough for interface, or the interface will take 967 * care of the fragmentation for us, can just send directly. 968 */ 969 if (ip->ip_len <= ifp->if_mtu || (ifp->if_hwassist & CSUM_FRAGMENT && 970 ((ip->ip_off & IP_DF) == 0))) { 971 ip->ip_len = htons(ip->ip_len); 972 ip->ip_off = htons(ip->ip_off); 973 ip->ip_sum = 0; 974 if (sw_csum & CSUM_DELAY_IP) 975 ip->ip_sum = in_cksum(m, hlen); 976 977 /* Record statistics for this interface address. */ 978 if (!(flags & IP_FORWARDING) && ia) { 979 ia->ia_ifa.if_opackets++; 980 ia->ia_ifa.if_obytes += m->m_pkthdr.len; 981 } 982 983#ifdef IPSEC 984 /* clean ipsec history once it goes out of the node */ 985 ipsec_delaux(m); 986#endif 987 988#ifdef MBUF_STRESS_TEST 989 if (mbuf_frag_size && m->m_pkthdr.len > mbuf_frag_size) 990 m = m_fragment(m, M_DONTWAIT, mbuf_frag_size); 991#endif 992 error = (*ifp->if_output)(ifp, m, 993 (struct sockaddr *)dst, ro->ro_rt); 994 goto done; 995 } 996 997 if (ip->ip_off & IP_DF) { 998 error = EMSGSIZE; 999 /* 1000 * This case can happen if the user changed the MTU 1001 * of an interface after enabling IP on it. Because 1002 * most netifs don't keep track of routes pointing to 1003 * them, there is no way for one to update all its 1004 * routes when the MTU is changed. 1005 */ 1006 if ((ro->ro_rt->rt_flags & (RTF_UP | RTF_HOST)) && 1007 (ro->ro_rt->rt_rmx.rmx_mtu > ifp->if_mtu)) { 1008 ro->ro_rt->rt_rmx.rmx_mtu = ifp->if_mtu; 1009 } 1010 ipstat.ips_cantfrag++; 1011 goto bad; 1012 } 1013 1014 /* 1015 * Too large for interface; fragment if possible. If successful, 1016 * on return, m will point to a list of packets to be sent. 1017 */ 1018 error = ip_fragment(ip, &m, ifp->if_mtu, ifp->if_hwassist, sw_csum); 1019 if (error) 1020 goto bad; 1021 for (; m; m = m0) { 1022 m0 = m->m_nextpkt; 1023 m->m_nextpkt = 0; 1024#ifdef IPSEC 1025 /* clean ipsec history once it goes out of the node */ 1026 ipsec_delaux(m); 1027#endif 1028 if (error == 0) { 1029 /* Record statistics for this interface address. */ 1030 if (ia != NULL) { 1031 ia->ia_ifa.if_opackets++; 1032 ia->ia_ifa.if_obytes += m->m_pkthdr.len; 1033 } 1034 1035 error = (*ifp->if_output)(ifp, m, 1036 (struct sockaddr *)dst, ro->ro_rt); 1037 } else 1038 m_freem(m); 1039 } 1040 1041 if (error == 0) 1042 ipstat.ips_fragmented++; 1043 1044done: 1045 if (ro == &iproute && ro->ro_rt) { 1046 RTFREE(ro->ro_rt); 1047 ro->ro_rt = NULL; 1048 } 1049 if (dummytag) { 1050 struct dn_pkt_tag *dt = (struct dn_pkt_tag *)(dummytag+1); 1051 if (dt->ro.ro_rt) 1052 RTFREE(dt->ro.ro_rt); 1053 m_tag_free(dummytag); 1054 } 1055#ifdef IPSEC 1056 if (sp != NULL) { 1057 KEYDEBUG(KEYDEBUG_IPSEC_STAMP, 1058 printf("DP ip_output call free SP:%p\n", sp)); 1059 key_freesp(sp); 1060 } 1061#endif 1062#ifdef FAST_IPSEC 1063 if (sp != NULL) 1064 KEY_FREESP(&sp); 1065#endif 1066 return (error); 1067bad: 1068 m_freem(m); 1069 goto done; 1070} 1071 1072/* 1073 * Create a chain of fragments which fit the given mtu. m_frag points to the 1074 * mbuf to be fragmented; on return it points to the chain with the fragments. 1075 * Return 0 if no error. If error, m_frag may contain a partially built 1076 * chain of fragments that should be freed by the caller. 1077 * 1078 * if_hwassist_flags is the hw offload capabilities (see if_data.ifi_hwassist) 1079 * sw_csum contains the delayed checksums flags (e.g., CSUM_DELAY_IP). 1080 */ 1081int 1082ip_fragment(struct ip *ip, struct mbuf **m_frag, int mtu, 1083 u_long if_hwassist_flags, int sw_csum) 1084{ 1085 int error = 0; 1086 int hlen = ip->ip_hl << 2; 1087 int len = (mtu - hlen) & ~7; /* size of payload in each fragment */ 1088 int off; 1089 struct mbuf *m0 = *m_frag; /* the original packet */ 1090 int firstlen; 1091 struct mbuf **mnext; 1092 int nfrags; 1093 1094 if (ip->ip_off & IP_DF) { /* Fragmentation not allowed */ 1095 ipstat.ips_cantfrag++; 1096 return EMSGSIZE; 1097 } 1098 1099 /* 1100 * Must be able to put at least 8 bytes per fragment. 1101 */ 1102 if (len < 8) 1103 return EMSGSIZE; 1104 1105 /* 1106 * If the interface will not calculate checksums on 1107 * fragmented packets, then do it here. 1108 */ 1109 if (m0->m_pkthdr.csum_flags & CSUM_DELAY_DATA && 1110 (if_hwassist_flags & CSUM_IP_FRAGS) == 0) { 1111 in_delayed_cksum(m0); 1112 m0->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA; 1113 } 1114 1115 if (len > PAGE_SIZE) { 1116 /* 1117 * Fragment large datagrams such that each segment 1118 * contains a multiple of PAGE_SIZE amount of data, 1119 * plus headers. This enables a receiver to perform 1120 * page-flipping zero-copy optimizations. 1121 * 1122 * XXX When does this help given that sender and receiver 1123 * could have different page sizes, and also mtu could 1124 * be less than the receiver's page size ? 1125 */ 1126 int newlen; 1127 struct mbuf *m; 1128 1129 for (m = m0, off = 0; m && (off+m->m_len) <= mtu; m = m->m_next) 1130 off += m->m_len; 1131 1132 /* 1133 * firstlen (off - hlen) must be aligned on an 1134 * 8-byte boundary 1135 */ 1136 if (off < hlen) 1137 goto smart_frag_failure; 1138 off = ((off - hlen) & ~7) + hlen; 1139 newlen = (~PAGE_MASK) & mtu; 1140 if ((newlen + sizeof (struct ip)) > mtu) { 1141 /* we failed, go back the default */ 1142smart_frag_failure: 1143 newlen = len; 1144 off = hlen + len; 1145 } 1146 len = newlen; 1147 1148 } else { 1149 off = hlen + len; 1150 } 1151 1152 firstlen = off - hlen; 1153 mnext = &m0->m_nextpkt; /* pointer to next packet */ 1154 1155 /* 1156 * Loop through length of segment after first fragment, 1157 * make new header and copy data of each part and link onto chain. 1158 * Here, m0 is the original packet, m is the fragment being created. 1159 * The fragments are linked off the m_nextpkt of the original 1160 * packet, which after processing serves as the first fragment. 1161 */ 1162 for (nfrags = 1; off < ip->ip_len; off += len, nfrags++) { 1163 struct ip *mhip; /* ip header on the fragment */ 1164 struct mbuf *m; 1165 int mhlen = sizeof (struct ip); 1166 1167 MGETHDR(m, M_DONTWAIT, MT_HEADER); 1168 if (m == 0) { 1169 error = ENOBUFS; 1170 ipstat.ips_odropped++; 1171 goto done; 1172 } 1173 m->m_flags |= (m0->m_flags & M_MCAST) | M_FRAG; 1174 /* 1175 * In the first mbuf, leave room for the link header, then 1176 * copy the original IP header including options. The payload 1177 * goes into an additional mbuf chain returned by m_copy(). 1178 */ 1179 m->m_data += max_linkhdr; 1180 mhip = mtod(m, struct ip *); 1181 *mhip = *ip; 1182 if (hlen > sizeof (struct ip)) { 1183 mhlen = ip_optcopy(ip, mhip) + sizeof (struct ip); 1184 mhip->ip_v = IPVERSION; 1185 mhip->ip_hl = mhlen >> 2; 1186 } 1187 m->m_len = mhlen; 1188 /* XXX do we need to add ip->ip_off below ? */ 1189 mhip->ip_off = ((off - hlen) >> 3) + ip->ip_off; 1190 if (off + len >= ip->ip_len) { /* last fragment */ 1191 len = ip->ip_len - off; 1192 m->m_flags |= M_LASTFRAG; 1193 } else 1194 mhip->ip_off |= IP_MF; 1195 mhip->ip_len = htons((u_short)(len + mhlen)); 1196 m->m_next = m_copy(m0, off, len); 1197 if (m->m_next == 0) { /* copy failed */ 1198 m_free(m); 1199 error = ENOBUFS; /* ??? */ 1200 ipstat.ips_odropped++; 1201 goto done; 1202 } 1203 m->m_pkthdr.len = mhlen + len; 1204 m->m_pkthdr.rcvif = (struct ifnet *)0; 1205#ifdef MAC 1206 mac_create_fragment(m0, m); 1207#endif 1208 m->m_pkthdr.csum_flags = m0->m_pkthdr.csum_flags; 1209 mhip->ip_off = htons(mhip->ip_off); 1210 mhip->ip_sum = 0; 1211 if (sw_csum & CSUM_DELAY_IP) 1212 mhip->ip_sum = in_cksum(m, mhlen); 1213 *mnext = m; 1214 mnext = &m->m_nextpkt; 1215 } 1216 ipstat.ips_ofragments += nfrags; 1217 1218 /* set first marker for fragment chain */ 1219 m0->m_flags |= M_FIRSTFRAG | M_FRAG; 1220 m0->m_pkthdr.csum_data = nfrags; 1221 1222 /* 1223 * Update first fragment by trimming what's been copied out 1224 * and updating header. 1225 */ 1226 m_adj(m0, hlen + firstlen - ip->ip_len); 1227 m0->m_pkthdr.len = hlen + firstlen; 1228 ip->ip_len = htons((u_short)m0->m_pkthdr.len); 1229 ip->ip_off |= IP_MF; 1230 ip->ip_off = htons(ip->ip_off); 1231 ip->ip_sum = 0; 1232 if (sw_csum & CSUM_DELAY_IP) 1233 ip->ip_sum = in_cksum(m0, hlen); 1234 1235done: 1236 *m_frag = m0; 1237 return error; 1238} 1239 1240void 1241in_delayed_cksum(struct mbuf *m) 1242{ 1243 struct ip *ip; 1244 u_short csum, offset; 1245 1246 ip = mtod(m, struct ip *); 1247 offset = ip->ip_hl << 2 ; 1248 csum = in_cksum_skip(m, ip->ip_len, offset); 1249 if (m->m_pkthdr.csum_flags & CSUM_UDP && csum == 0) 1250 csum = 0xffff; 1251 offset += m->m_pkthdr.csum_data; /* checksum offset */ 1252 1253 if (offset + sizeof(u_short) > m->m_len) { 1254 printf("delayed m_pullup, m->len: %d off: %d p: %d\n", 1255 m->m_len, offset, ip->ip_p); 1256 /* 1257 * XXX 1258 * this shouldn't happen, but if it does, the 1259 * correct behavior may be to insert the checksum 1260 * in the existing chain instead of rearranging it. 1261 */ 1262 m = m_pullup(m, offset + sizeof(u_short)); 1263 } 1264 *(u_short *)(m->m_data + offset) = csum; 1265} 1266 1267/* 1268 * Insert IP options into preformed packet. 1269 * Adjust IP destination as required for IP source routing, 1270 * as indicated by a non-zero in_addr at the start of the options. 1271 * 1272 * XXX This routine assumes that the packet has no options in place. 1273 */ 1274static struct mbuf * 1275ip_insertoptions(m, opt, phlen) 1276 register struct mbuf *m; 1277 struct mbuf *opt; 1278 int *phlen; 1279{ 1280 register struct ipoption *p = mtod(opt, struct ipoption *); 1281 struct mbuf *n; 1282 register struct ip *ip = mtod(m, struct ip *); 1283 unsigned optlen; 1284 1285 optlen = opt->m_len - sizeof(p->ipopt_dst); 1286 if (optlen + ip->ip_len > IP_MAXPACKET) { 1287 *phlen = 0; 1288 return (m); /* XXX should fail */ 1289 } 1290 if (p->ipopt_dst.s_addr) 1291 ip->ip_dst = p->ipopt_dst; 1292 if (m->m_flags & M_EXT || m->m_data - optlen < m->m_pktdat) { 1293 MGETHDR(n, M_DONTWAIT, MT_HEADER); 1294 if (n == 0) { 1295 *phlen = 0; 1296 return (m); 1297 } 1298 n->m_pkthdr.rcvif = (struct ifnet *)0; 1299#ifdef MAC 1300 mac_create_mbuf_from_mbuf(m, n); 1301#endif 1302 n->m_pkthdr.len = m->m_pkthdr.len + optlen; 1303 m->m_len -= sizeof(struct ip); 1304 m->m_data += sizeof(struct ip); 1305 n->m_next = m; 1306 m = n; 1307 m->m_len = optlen + sizeof(struct ip); 1308 m->m_data += max_linkhdr; 1309 bcopy(ip, mtod(m, void *), sizeof(struct ip)); 1310 } else { 1311 m->m_data -= optlen; 1312 m->m_len += optlen; 1313 m->m_pkthdr.len += optlen; 1314 bcopy(ip, mtod(m, void *), sizeof(struct ip)); 1315 } 1316 ip = mtod(m, struct ip *); 1317 bcopy(p->ipopt_list, ip + 1, optlen); 1318 *phlen = sizeof(struct ip) + optlen; 1319 ip->ip_v = IPVERSION; 1320 ip->ip_hl = *phlen >> 2; 1321 ip->ip_len += optlen; 1322 return (m); 1323} 1324 1325/* 1326 * Copy options from ip to jp, 1327 * omitting those not copied during fragmentation. 1328 */ 1329int 1330ip_optcopy(ip, jp) 1331 struct ip *ip, *jp; 1332{ 1333 register u_char *cp, *dp; 1334 int opt, optlen, cnt; 1335 1336 cp = (u_char *)(ip + 1); 1337 dp = (u_char *)(jp + 1); 1338 cnt = (ip->ip_hl << 2) - sizeof (struct ip); 1339 for (; cnt > 0; cnt -= optlen, cp += optlen) { 1340 opt = cp[0]; 1341 if (opt == IPOPT_EOL) 1342 break; 1343 if (opt == IPOPT_NOP) { 1344 /* Preserve for IP mcast tunnel's LSRR alignment. */ 1345 *dp++ = IPOPT_NOP; 1346 optlen = 1; 1347 continue; 1348 } 1349 1350 KASSERT(cnt >= IPOPT_OLEN + sizeof(*cp), 1351 ("ip_optcopy: malformed ipv4 option")); 1352 optlen = cp[IPOPT_OLEN]; 1353 KASSERT(optlen >= IPOPT_OLEN + sizeof(*cp) && optlen <= cnt, 1354 ("ip_optcopy: malformed ipv4 option")); 1355 1356 /* bogus lengths should have been caught by ip_dooptions */ 1357 if (optlen > cnt) 1358 optlen = cnt; 1359 if (IPOPT_COPIED(opt)) { 1360 bcopy(cp, dp, optlen); 1361 dp += optlen; 1362 } 1363 } 1364 for (optlen = dp - (u_char *)(jp+1); optlen & 0x3; optlen++) 1365 *dp++ = IPOPT_EOL; 1366 return (optlen); 1367} 1368 1369/* 1370 * IP socket option processing. 1371 */ 1372int 1373ip_ctloutput(so, sopt) 1374 struct socket *so; 1375 struct sockopt *sopt; 1376{ 1377 struct inpcb *inp = sotoinpcb(so); 1378 int error, optval; 1379 1380 error = optval = 0; 1381 if (sopt->sopt_level != IPPROTO_IP) { 1382 return (EINVAL); 1383 } 1384 1385 switch (sopt->sopt_dir) { 1386 case SOPT_SET: 1387 switch (sopt->sopt_name) { 1388 case IP_OPTIONS: 1389#ifdef notyet 1390 case IP_RETOPTS: 1391#endif 1392 { 1393 struct mbuf *m; 1394 if (sopt->sopt_valsize > MLEN) { 1395 error = EMSGSIZE; 1396 break; 1397 } 1398 MGET(m, sopt->sopt_td ? M_TRYWAIT : M_DONTWAIT, MT_HEADER); 1399 if (m == 0) { 1400 error = ENOBUFS; 1401 break; 1402 } 1403 m->m_len = sopt->sopt_valsize; 1404 error = sooptcopyin(sopt, mtod(m, char *), m->m_len, 1405 m->m_len); 1406 1407 return (ip_pcbopts(sopt->sopt_name, &inp->inp_options, 1408 m)); 1409 } 1410 1411 case IP_TOS: 1412 case IP_TTL: 1413 case IP_RECVOPTS: 1414 case IP_RECVRETOPTS: 1415 case IP_RECVDSTADDR: 1416 case IP_RECVTTL: 1417 case IP_RECVIF: 1418 case IP_FAITH: 1419 case IP_ONESBCAST: 1420 error = sooptcopyin(sopt, &optval, sizeof optval, 1421 sizeof optval); 1422 if (error) 1423 break; 1424 1425 switch (sopt->sopt_name) { 1426 case IP_TOS: 1427 inp->inp_ip_tos = optval; 1428 break; 1429 1430 case IP_TTL: 1431 inp->inp_ip_ttl = optval; 1432 break; 1433#define OPTSET(bit) \ 1434 if (optval) \ 1435 inp->inp_flags |= bit; \ 1436 else \ 1437 inp->inp_flags &= ~bit; 1438 1439 case IP_RECVOPTS: 1440 OPTSET(INP_RECVOPTS); 1441 break; 1442 1443 case IP_RECVRETOPTS: 1444 OPTSET(INP_RECVRETOPTS); 1445 break; 1446 1447 case IP_RECVDSTADDR: 1448 OPTSET(INP_RECVDSTADDR); 1449 break; 1450 1451 case IP_RECVTTL: 1452 OPTSET(INP_RECVTTL); 1453 break; 1454 1455 case IP_RECVIF: 1456 OPTSET(INP_RECVIF); 1457 break; 1458 1459 case IP_FAITH: 1460 OPTSET(INP_FAITH); 1461 break; 1462 1463 case IP_ONESBCAST: 1464 OPTSET(INP_ONESBCAST); 1465 break; 1466 } 1467 break; 1468#undef OPTSET 1469 1470 case IP_MULTICAST_IF: 1471 case IP_MULTICAST_VIF: 1472 case IP_MULTICAST_TTL: 1473 case IP_MULTICAST_LOOP: 1474 case IP_ADD_MEMBERSHIP: 1475 case IP_DROP_MEMBERSHIP: 1476 error = ip_setmoptions(sopt, &inp->inp_moptions); 1477 break; 1478 1479 case IP_PORTRANGE: 1480 error = sooptcopyin(sopt, &optval, sizeof optval, 1481 sizeof optval); 1482 if (error) 1483 break; 1484 1485 switch (optval) { 1486 case IP_PORTRANGE_DEFAULT: 1487 inp->inp_flags &= ~(INP_LOWPORT); 1488 inp->inp_flags &= ~(INP_HIGHPORT); 1489 break; 1490 1491 case IP_PORTRANGE_HIGH: 1492 inp->inp_flags &= ~(INP_LOWPORT); 1493 inp->inp_flags |= INP_HIGHPORT; 1494 break; 1495 1496 case IP_PORTRANGE_LOW: 1497 inp->inp_flags &= ~(INP_HIGHPORT); 1498 inp->inp_flags |= INP_LOWPORT; 1499 break; 1500 1501 default: 1502 error = EINVAL; 1503 break; 1504 } 1505 break; 1506 1507#if defined(IPSEC) || defined(FAST_IPSEC) 1508 case IP_IPSEC_POLICY: 1509 { 1510 caddr_t req; 1511 size_t len = 0; 1512 int priv; 1513 struct mbuf *m; 1514 int optname; 1515 1516 if ((error = soopt_getm(sopt, &m)) != 0) /* XXX */ 1517 break; 1518 if ((error = soopt_mcopyin(sopt, m)) != 0) /* XXX */ 1519 break; 1520 priv = (sopt->sopt_td != NULL && 1521 suser(sopt->sopt_td) != 0) ? 0 : 1; 1522 req = mtod(m, caddr_t); 1523 len = m->m_len; 1524 optname = sopt->sopt_name; 1525 error = ipsec4_set_policy(inp, optname, req, len, priv); 1526 m_freem(m); 1527 break; 1528 } 1529#endif /*IPSEC*/ 1530 1531 default: 1532 error = ENOPROTOOPT; 1533 break; 1534 } 1535 break; 1536 1537 case SOPT_GET: 1538 switch (sopt->sopt_name) { 1539 case IP_OPTIONS: 1540 case IP_RETOPTS: 1541 if (inp->inp_options) 1542 error = sooptcopyout(sopt, 1543 mtod(inp->inp_options, 1544 char *), 1545 inp->inp_options->m_len); 1546 else 1547 sopt->sopt_valsize = 0; 1548 break; 1549 1550 case IP_TOS: 1551 case IP_TTL: 1552 case IP_RECVOPTS: 1553 case IP_RECVRETOPTS: 1554 case IP_RECVDSTADDR: 1555 case IP_RECVTTL: 1556 case IP_RECVIF: 1557 case IP_PORTRANGE: 1558 case IP_FAITH: 1559 case IP_ONESBCAST: 1560 switch (sopt->sopt_name) { 1561 1562 case IP_TOS: 1563 optval = inp->inp_ip_tos; 1564 break; 1565 1566 case IP_TTL: 1567 optval = inp->inp_ip_ttl; 1568 break; 1569 1570#define OPTBIT(bit) (inp->inp_flags & bit ? 1 : 0) 1571 1572 case IP_RECVOPTS: 1573 optval = OPTBIT(INP_RECVOPTS); 1574 break; 1575 1576 case IP_RECVRETOPTS: 1577 optval = OPTBIT(INP_RECVRETOPTS); 1578 break; 1579 1580 case IP_RECVDSTADDR: 1581 optval = OPTBIT(INP_RECVDSTADDR); 1582 break; 1583 1584 case IP_RECVTTL: 1585 optval = OPTBIT(INP_RECVTTL); 1586 break; 1587 1588 case IP_RECVIF: 1589 optval = OPTBIT(INP_RECVIF); 1590 break; 1591 1592 case IP_PORTRANGE: 1593 if (inp->inp_flags & INP_HIGHPORT) 1594 optval = IP_PORTRANGE_HIGH; 1595 else if (inp->inp_flags & INP_LOWPORT) 1596 optval = IP_PORTRANGE_LOW; 1597 else 1598 optval = 0; 1599 break; 1600 1601 case IP_FAITH: 1602 optval = OPTBIT(INP_FAITH); 1603 break; 1604 1605 case IP_ONESBCAST: 1606 optval = OPTBIT(INP_ONESBCAST); 1607 break; 1608 } 1609 error = sooptcopyout(sopt, &optval, sizeof optval); 1610 break; 1611 1612 case IP_MULTICAST_IF: 1613 case IP_MULTICAST_VIF: 1614 case IP_MULTICAST_TTL: 1615 case IP_MULTICAST_LOOP: 1616 case IP_ADD_MEMBERSHIP: 1617 case IP_DROP_MEMBERSHIP: 1618 error = ip_getmoptions(sopt, inp->inp_moptions); 1619 break; 1620 1621#if defined(IPSEC) || defined(FAST_IPSEC) 1622 case IP_IPSEC_POLICY: 1623 { 1624 struct mbuf *m = NULL; 1625 caddr_t req = NULL; 1626 size_t len = 0; 1627 1628 if (m != 0) { 1629 req = mtod(m, caddr_t); 1630 len = m->m_len; 1631 } 1632 error = ipsec4_get_policy(sotoinpcb(so), req, len, &m); 1633 if (error == 0) 1634 error = soopt_mcopyout(sopt, m); /* XXX */ 1635 if (error == 0) 1636 m_freem(m); 1637 break; 1638 } 1639#endif /*IPSEC*/ 1640 1641 default: 1642 error = ENOPROTOOPT; 1643 break; 1644 } 1645 break; 1646 } 1647 return (error); 1648} 1649 1650/* 1651 * Set up IP options in pcb for insertion in output packets. 1652 * Store in mbuf with pointer in pcbopt, adding pseudo-option 1653 * with destination address if source routed. 1654 */ 1655static int 1656ip_pcbopts(optname, pcbopt, m) 1657 int optname; 1658 struct mbuf **pcbopt; 1659 register struct mbuf *m; 1660{ 1661 register int cnt, optlen; 1662 register u_char *cp; 1663 u_char opt; 1664 1665 /* turn off any old options */ 1666 if (*pcbopt) 1667 (void)m_free(*pcbopt); 1668 *pcbopt = 0; 1669 if (m == (struct mbuf *)0 || m->m_len == 0) { 1670 /* 1671 * Only turning off any previous options. 1672 */ 1673 if (m) 1674 (void)m_free(m); 1675 return (0); 1676 } 1677 1678 if (m->m_len % sizeof(int32_t)) 1679 goto bad; 1680 /* 1681 * IP first-hop destination address will be stored before 1682 * actual options; move other options back 1683 * and clear it when none present. 1684 */ 1685 if (m->m_data + m->m_len + sizeof(struct in_addr) >= &m->m_dat[MLEN]) 1686 goto bad; 1687 cnt = m->m_len; 1688 m->m_len += sizeof(struct in_addr); 1689 cp = mtod(m, u_char *) + sizeof(struct in_addr); 1690 bcopy(mtod(m, void *), cp, (unsigned)cnt); 1691 bzero(mtod(m, void *), sizeof(struct in_addr)); 1692 1693 for (; cnt > 0; cnt -= optlen, cp += optlen) { 1694 opt = cp[IPOPT_OPTVAL]; 1695 if (opt == IPOPT_EOL) 1696 break; 1697 if (opt == IPOPT_NOP) 1698 optlen = 1; 1699 else { 1700 if (cnt < IPOPT_OLEN + sizeof(*cp)) 1701 goto bad; 1702 optlen = cp[IPOPT_OLEN]; 1703 if (optlen < IPOPT_OLEN + sizeof(*cp) || optlen > cnt) 1704 goto bad; 1705 } 1706 switch (opt) { 1707 1708 default: 1709 break; 1710 1711 case IPOPT_LSRR: 1712 case IPOPT_SSRR: 1713 /* 1714 * user process specifies route as: 1715 * ->A->B->C->D 1716 * D must be our final destination (but we can't 1717 * check that since we may not have connected yet). 1718 * A is first hop destination, which doesn't appear in 1719 * actual IP option, but is stored before the options. 1720 */ 1721 if (optlen < IPOPT_MINOFF - 1 + sizeof(struct in_addr)) 1722 goto bad; 1723 m->m_len -= sizeof(struct in_addr); 1724 cnt -= sizeof(struct in_addr); 1725 optlen -= sizeof(struct in_addr); 1726 cp[IPOPT_OLEN] = optlen; 1727 /* 1728 * Move first hop before start of options. 1729 */ 1730 bcopy((caddr_t)&cp[IPOPT_OFFSET+1], mtod(m, caddr_t), 1731 sizeof(struct in_addr)); 1732 /* 1733 * Then copy rest of options back 1734 * to close up the deleted entry. 1735 */ 1736 bcopy((&cp[IPOPT_OFFSET+1] + sizeof(struct in_addr)), 1737 &cp[IPOPT_OFFSET+1], 1738 (unsigned)cnt - (IPOPT_MINOFF - 1)); 1739 break; 1740 } 1741 } 1742 if (m->m_len > MAX_IPOPTLEN + sizeof(struct in_addr)) 1743 goto bad; 1744 *pcbopt = m; 1745 return (0); 1746 1747bad: 1748 (void)m_free(m); 1749 return (EINVAL); 1750} 1751 1752/* 1753 * XXX 1754 * The whole multicast option thing needs to be re-thought. 1755 * Several of these options are equally applicable to non-multicast 1756 * transmission, and one (IP_MULTICAST_TTL) totally duplicates a 1757 * standard option (IP_TTL). 1758 */ 1759 1760/* 1761 * following RFC1724 section 3.3, 0.0.0.0/8 is interpreted as interface index. 1762 */ 1763static struct ifnet * 1764ip_multicast_if(a, ifindexp) 1765 struct in_addr *a; 1766 int *ifindexp; 1767{ 1768 int ifindex; 1769 struct ifnet *ifp; 1770 1771 if (ifindexp) 1772 *ifindexp = 0; 1773 if (ntohl(a->s_addr) >> 24 == 0) { 1774 ifindex = ntohl(a->s_addr) & 0xffffff; 1775 if (ifindex < 0 || if_index < ifindex) 1776 return NULL; 1777 ifp = ifnet_byindex(ifindex); 1778 if (ifindexp) 1779 *ifindexp = ifindex; 1780 } else { 1781 INADDR_TO_IFP(*a, ifp); 1782 } 1783 return ifp; 1784} 1785 1786/* 1787 * Set the IP multicast options in response to user setsockopt(). 1788 */ 1789static int 1790ip_setmoptions(sopt, imop) 1791 struct sockopt *sopt; 1792 struct ip_moptions **imop; 1793{ 1794 int error = 0; 1795 int i; 1796 struct in_addr addr; 1797 struct ip_mreq mreq; 1798 struct ifnet *ifp; 1799 struct ip_moptions *imo = *imop; 1800 struct route ro; 1801 struct sockaddr_in *dst; 1802 int ifindex; 1803 int s; 1804 1805 if (imo == NULL) { 1806 /* 1807 * No multicast option buffer attached to the pcb; 1808 * allocate one and initialize to default values. 1809 */ 1810 imo = (struct ip_moptions*)malloc(sizeof(*imo), M_IPMOPTS, 1811 M_WAITOK); 1812 1813 if (imo == NULL) 1814 return (ENOBUFS); 1815 *imop = imo; 1816 imo->imo_multicast_ifp = NULL; 1817 imo->imo_multicast_addr.s_addr = INADDR_ANY; 1818 imo->imo_multicast_vif = -1; 1819 imo->imo_multicast_ttl = IP_DEFAULT_MULTICAST_TTL; 1820 imo->imo_multicast_loop = IP_DEFAULT_MULTICAST_LOOP; 1821 imo->imo_num_memberships = 0; 1822 } 1823 1824 switch (sopt->sopt_name) { 1825 /* store an index number for the vif you wanna use in the send */ 1826 case IP_MULTICAST_VIF: 1827 if (legal_vif_num == 0) { 1828 error = EOPNOTSUPP; 1829 break; 1830 } 1831 error = sooptcopyin(sopt, &i, sizeof i, sizeof i); 1832 if (error) 1833 break; 1834 if (!legal_vif_num(i) && (i != -1)) { 1835 error = EINVAL; 1836 break; 1837 } 1838 imo->imo_multicast_vif = i; 1839 break; 1840 1841 case IP_MULTICAST_IF: 1842 /* 1843 * Select the interface for outgoing multicast packets. 1844 */ 1845 error = sooptcopyin(sopt, &addr, sizeof addr, sizeof addr); 1846 if (error) 1847 break; 1848 /* 1849 * INADDR_ANY is used to remove a previous selection. 1850 * When no interface is selected, a default one is 1851 * chosen every time a multicast packet is sent. 1852 */ 1853 if (addr.s_addr == INADDR_ANY) { 1854 imo->imo_multicast_ifp = NULL; 1855 break; 1856 } 1857 /* 1858 * The selected interface is identified by its local 1859 * IP address. Find the interface and confirm that 1860 * it supports multicasting. 1861 */ 1862 s = splimp(); 1863 ifp = ip_multicast_if(&addr, &ifindex); 1864 if (ifp == NULL || (ifp->if_flags & IFF_MULTICAST) == 0) { 1865 splx(s); 1866 error = EADDRNOTAVAIL; 1867 break; 1868 } 1869 imo->imo_multicast_ifp = ifp; 1870 if (ifindex) 1871 imo->imo_multicast_addr = addr; 1872 else 1873 imo->imo_multicast_addr.s_addr = INADDR_ANY; 1874 splx(s); 1875 break; 1876 1877 case IP_MULTICAST_TTL: 1878 /* 1879 * Set the IP time-to-live for outgoing multicast packets. 1880 * The original multicast API required a char argument, 1881 * which is inconsistent with the rest of the socket API. 1882 * We allow either a char or an int. 1883 */ 1884 if (sopt->sopt_valsize == 1) { 1885 u_char ttl; 1886 error = sooptcopyin(sopt, &ttl, 1, 1); 1887 if (error) 1888 break; 1889 imo->imo_multicast_ttl = ttl; 1890 } else { 1891 u_int ttl; 1892 error = sooptcopyin(sopt, &ttl, sizeof ttl, 1893 sizeof ttl); 1894 if (error) 1895 break; 1896 if (ttl > 255) 1897 error = EINVAL; 1898 else 1899 imo->imo_multicast_ttl = ttl; 1900 } 1901 break; 1902 1903 case IP_MULTICAST_LOOP: 1904 /* 1905 * Set the loopback flag for outgoing multicast packets. 1906 * Must be zero or one. The original multicast API required a 1907 * char argument, which is inconsistent with the rest 1908 * of the socket API. We allow either a char or an int. 1909 */ 1910 if (sopt->sopt_valsize == 1) { 1911 u_char loop; 1912 error = sooptcopyin(sopt, &loop, 1, 1); 1913 if (error) 1914 break; 1915 imo->imo_multicast_loop = !!loop; 1916 } else { 1917 u_int loop; 1918 error = sooptcopyin(sopt, &loop, sizeof loop, 1919 sizeof loop); 1920 if (error) 1921 break; 1922 imo->imo_multicast_loop = !!loop; 1923 } 1924 break; 1925 1926 case IP_ADD_MEMBERSHIP: 1927 /* 1928 * Add a multicast group membership. 1929 * Group must be a valid IP multicast address. 1930 */ 1931 error = sooptcopyin(sopt, &mreq, sizeof mreq, sizeof mreq); 1932 if (error) 1933 break; 1934 1935 if (!IN_MULTICAST(ntohl(mreq.imr_multiaddr.s_addr))) { 1936 error = EINVAL; 1937 break; 1938 } 1939 s = splimp(); 1940 /* 1941 * If no interface address was provided, use the interface of 1942 * the route to the given multicast address. 1943 */ 1944 if (mreq.imr_interface.s_addr == INADDR_ANY) { 1945 bzero((caddr_t)&ro, sizeof(ro)); 1946 dst = (struct sockaddr_in *)&ro.ro_dst; 1947 dst->sin_len = sizeof(*dst); 1948 dst->sin_family = AF_INET; 1949 dst->sin_addr = mreq.imr_multiaddr; 1950 rtalloc_ign(&ro, RTF_CLONING); 1951 if (ro.ro_rt == NULL) { 1952 error = EADDRNOTAVAIL; 1953 splx(s); 1954 break; 1955 } 1956 ifp = ro.ro_rt->rt_ifp; 1957 RTFREE(ro.ro_rt); 1958 } 1959 else { 1960 ifp = ip_multicast_if(&mreq.imr_interface, NULL); 1961 } 1962 1963 /* 1964 * See if we found an interface, and confirm that it 1965 * supports multicast. 1966 */ 1967 if (ifp == NULL || (ifp->if_flags & IFF_MULTICAST) == 0) { 1968 error = EADDRNOTAVAIL; 1969 splx(s); 1970 break; 1971 } 1972 /* 1973 * See if the membership already exists or if all the 1974 * membership slots are full. 1975 */ 1976 for (i = 0; i < imo->imo_num_memberships; ++i) { 1977 if (imo->imo_membership[i]->inm_ifp == ifp && 1978 imo->imo_membership[i]->inm_addr.s_addr 1979 == mreq.imr_multiaddr.s_addr) 1980 break; 1981 } 1982 if (i < imo->imo_num_memberships) { 1983 error = EADDRINUSE; 1984 splx(s); 1985 break; 1986 } 1987 if (i == IP_MAX_MEMBERSHIPS) { 1988 error = ETOOMANYREFS; 1989 splx(s); 1990 break; 1991 } 1992 /* 1993 * Everything looks good; add a new record to the multicast 1994 * address list for the given interface. 1995 */ 1996 if ((imo->imo_membership[i] = 1997 in_addmulti(&mreq.imr_multiaddr, ifp)) == NULL) { 1998 error = ENOBUFS; 1999 splx(s); 2000 break; 2001 } 2002 ++imo->imo_num_memberships; 2003 splx(s); 2004 break; 2005 2006 case IP_DROP_MEMBERSHIP: 2007 /* 2008 * Drop a multicast group membership. 2009 * Group must be a valid IP multicast address. 2010 */ 2011 error = sooptcopyin(sopt, &mreq, sizeof mreq, sizeof mreq); 2012 if (error) 2013 break; 2014 2015 if (!IN_MULTICAST(ntohl(mreq.imr_multiaddr.s_addr))) { 2016 error = EINVAL; 2017 break; 2018 } 2019 2020 s = splimp(); 2021 /* 2022 * If an interface address was specified, get a pointer 2023 * to its ifnet structure. 2024 */ 2025 if (mreq.imr_interface.s_addr == INADDR_ANY) 2026 ifp = NULL; 2027 else { 2028 ifp = ip_multicast_if(&mreq.imr_interface, NULL); 2029 if (ifp == NULL) { 2030 error = EADDRNOTAVAIL; 2031 splx(s); 2032 break; 2033 } 2034 } 2035 /* 2036 * Find the membership in the membership array. 2037 */ 2038 for (i = 0; i < imo->imo_num_memberships; ++i) { 2039 if ((ifp == NULL || 2040 imo->imo_membership[i]->inm_ifp == ifp) && 2041 imo->imo_membership[i]->inm_addr.s_addr == 2042 mreq.imr_multiaddr.s_addr) 2043 break; 2044 } 2045 if (i == imo->imo_num_memberships) { 2046 error = EADDRNOTAVAIL; 2047 splx(s); 2048 break; 2049 } 2050 /* 2051 * Give up the multicast address record to which the 2052 * membership points. 2053 */ 2054 in_delmulti(imo->imo_membership[i]); 2055 /* 2056 * Remove the gap in the membership array. 2057 */ 2058 for (++i; i < imo->imo_num_memberships; ++i) 2059 imo->imo_membership[i-1] = imo->imo_membership[i]; 2060 --imo->imo_num_memberships; 2061 splx(s); 2062 break; 2063 2064 default: 2065 error = EOPNOTSUPP; 2066 break; 2067 } 2068 2069 /* 2070 * If all options have default values, no need to keep the mbuf. 2071 */ 2072 if (imo->imo_multicast_ifp == NULL && 2073 imo->imo_multicast_vif == -1 && 2074 imo->imo_multicast_ttl == IP_DEFAULT_MULTICAST_TTL && 2075 imo->imo_multicast_loop == IP_DEFAULT_MULTICAST_LOOP && 2076 imo->imo_num_memberships == 0) { 2077 free(*imop, M_IPMOPTS); 2078 *imop = NULL; 2079 } 2080 2081 return (error); 2082} 2083 2084/* 2085 * Return the IP multicast options in response to user getsockopt(). 2086 */ 2087static int 2088ip_getmoptions(sopt, imo) 2089 struct sockopt *sopt; 2090 register struct ip_moptions *imo; 2091{ 2092 struct in_addr addr; 2093 struct in_ifaddr *ia; 2094 int error, optval; 2095 u_char coptval; 2096 2097 error = 0; 2098 switch (sopt->sopt_name) { 2099 case IP_MULTICAST_VIF: 2100 if (imo != NULL) 2101 optval = imo->imo_multicast_vif; 2102 else 2103 optval = -1; 2104 error = sooptcopyout(sopt, &optval, sizeof optval); 2105 break; 2106 2107 case IP_MULTICAST_IF: 2108 if (imo == NULL || imo->imo_multicast_ifp == NULL) 2109 addr.s_addr = INADDR_ANY; 2110 else if (imo->imo_multicast_addr.s_addr) { 2111 /* return the value user has set */ 2112 addr = imo->imo_multicast_addr; 2113 } else { 2114 IFP_TO_IA(imo->imo_multicast_ifp, ia); 2115 addr.s_addr = (ia == NULL) ? INADDR_ANY 2116 : IA_SIN(ia)->sin_addr.s_addr; 2117 } 2118 error = sooptcopyout(sopt, &addr, sizeof addr); 2119 break; 2120 2121 case IP_MULTICAST_TTL: 2122 if (imo == 0) 2123 optval = coptval = IP_DEFAULT_MULTICAST_TTL; 2124 else 2125 optval = coptval = imo->imo_multicast_ttl; 2126 if (sopt->sopt_valsize == 1) 2127 error = sooptcopyout(sopt, &coptval, 1); 2128 else 2129 error = sooptcopyout(sopt, &optval, sizeof optval); 2130 break; 2131 2132 case IP_MULTICAST_LOOP: 2133 if (imo == 0) 2134 optval = coptval = IP_DEFAULT_MULTICAST_LOOP; 2135 else 2136 optval = coptval = imo->imo_multicast_loop; 2137 if (sopt->sopt_valsize == 1) 2138 error = sooptcopyout(sopt, &coptval, 1); 2139 else 2140 error = sooptcopyout(sopt, &optval, sizeof optval); 2141 break; 2142 2143 default: 2144 error = ENOPROTOOPT; 2145 break; 2146 } 2147 return (error); 2148} 2149 2150/* 2151 * Discard the IP multicast options. 2152 */ 2153void 2154ip_freemoptions(imo) 2155 register struct ip_moptions *imo; 2156{ 2157 register int i; 2158 2159 if (imo != NULL) { 2160 for (i = 0; i < imo->imo_num_memberships; ++i) 2161 in_delmulti(imo->imo_membership[i]); 2162 free(imo, M_IPMOPTS); 2163 } 2164} 2165 2166/* 2167 * Routine called from ip_output() to loop back a copy of an IP multicast 2168 * packet to the input queue of a specified interface. Note that this 2169 * calls the output routine of the loopback "driver", but with an interface 2170 * pointer that might NOT be a loopback interface -- evil, but easier than 2171 * replicating that code here. 2172 */ 2173static void 2174ip_mloopback(ifp, m, dst, hlen) 2175 struct ifnet *ifp; 2176 register struct mbuf *m; 2177 register struct sockaddr_in *dst; 2178 int hlen; 2179{ 2180 register struct ip *ip; 2181 struct mbuf *copym; 2182 2183 copym = m_copy(m, 0, M_COPYALL); 2184 if (copym != NULL && (copym->m_flags & M_EXT || copym->m_len < hlen)) 2185 copym = m_pullup(copym, hlen); 2186 if (copym != NULL) { 2187 /* If needed, compute the checksum and mark it as valid. */ 2188 if (copym->m_pkthdr.csum_flags & CSUM_DELAY_DATA) { 2189 in_delayed_cksum(copym); 2190 copym->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA; 2191 copym->m_pkthdr.csum_flags |= 2192 CSUM_DATA_VALID | CSUM_PSEUDO_HDR; 2193 copym->m_pkthdr.csum_data = 0xffff; 2194 } 2195 /* 2196 * We don't bother to fragment if the IP length is greater 2197 * than the interface's MTU. Can this possibly matter? 2198 */ 2199 ip = mtod(copym, struct ip *); 2200 ip->ip_len = htons(ip->ip_len); 2201 ip->ip_off = htons(ip->ip_off); 2202 ip->ip_sum = 0; 2203 ip->ip_sum = in_cksum(copym, hlen); 2204 /* 2205 * NB: 2206 * It's not clear whether there are any lingering 2207 * reentrancy problems in other areas which might 2208 * be exposed by using ip_input directly (in 2209 * particular, everything which modifies the packet 2210 * in-place). Yet another option is using the 2211 * protosw directly to deliver the looped back 2212 * packet. For the moment, we'll err on the side 2213 * of safety by using if_simloop(). 2214 */ 2215#if 1 /* XXX */ 2216 if (dst->sin_family != AF_INET) { 2217 printf("ip_mloopback: bad address family %d\n", 2218 dst->sin_family); 2219 dst->sin_family = AF_INET; 2220 } 2221#endif 2222 2223#ifdef notdef 2224 copym->m_pkthdr.rcvif = ifp; 2225 ip_input(copym); 2226#else 2227 if_simloop(ifp, copym, dst->sin_family, 0); 2228#endif 2229 } 2230} 2231