/* $NetBSD: ip_output.c,v 1.230.2.1 2014/12/01 10:35:37 martin Exp $ */ /* * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project. * 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. Neither the name of the project 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 PROJECT 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 PROJECT 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. */ /*- * Copyright (c) 1998 The NetBSD Foundation, Inc. * All rights reserved. * * This code is derived from software contributed to The NetBSD Foundation * by Public Access Networks Corporation ("Panix"). It was developed under * contract to Panix by Eric Haszlakiewicz and Thor Lancelot Simon. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. 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 FOUNDATION 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. */ /* * 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. 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 */ #include __KERNEL_RCSID(0, "$NetBSD: ip_output.c,v 1.230.2.1 2014/12/01 10:35:37 martin Exp $"); #include "opt_inet.h" #include "opt_ipsec.h" #include "opt_mrouting.h" #include #include #include #include #include #include #include #ifdef IPSEC #include #endif #include #include #include #include #include #include #include #include #include #include #include #include #include #include #ifdef MROUTING #include #endif #include #include static int ip_pcbopts(struct inpcb *, const struct sockopt *); static struct mbuf *ip_insertoptions(struct mbuf *, struct mbuf *, int *); static struct ifnet *ip_multicast_if(struct in_addr *, int *); static void ip_mloopback(struct ifnet *, struct mbuf *, const struct sockaddr_in *); static int ip_setmoptions(struct inpcb *, const struct sockopt *); static int ip_getmoptions(struct inpcb *, struct sockopt *); extern pfil_head_t *inet_pfil_hook; /* XXX */ int ip_do_loopback_cksum = 0; /* * 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 rtentry *rt; struct ip *ip; struct ifnet *ifp; struct mbuf *m = m0; int hlen = sizeof (struct ip); int len, error = 0; struct route iproute; const struct sockaddr_in *dst; struct in_ifaddr *ia; struct mbuf *opt; struct route *ro; int flags, sw_csum; u_long mtu; struct ip_moptions *imo; struct socket *so; va_list ap; #ifdef IPSEC struct secpolicy *sp = NULL; #endif bool natt_frag = false; bool rtmtu_nolock; union { struct sockaddr dst; struct sockaddr_in dst4; } u; struct sockaddr *rdst = &u.dst; /* real IP destination, as opposed * to the nexthop */ len = 0; va_start(ap, m0); opt = va_arg(ap, struct mbuf *); ro = va_arg(ap, struct route *); flags = va_arg(ap, int); imo = va_arg(ap, struct ip_moptions *); so = va_arg(ap, struct socket *); va_end(ap); MCLAIM(m, &ip_tx_mowner); KASSERT((m->m_flags & M_PKTHDR) != 0); KASSERT((m->m_pkthdr.csum_flags & (M_CSUM_TCPv6|M_CSUM_UDPv6)) == 0); KASSERT((m->m_pkthdr.csum_flags & (M_CSUM_TCPv4|M_CSUM_UDPv4)) != (M_CSUM_TCPv4|M_CSUM_UDPv4)); if (opt) { m = ip_insertoptions(m, opt, &len); if (len >= sizeof(struct ip)) hlen = len; } ip = mtod(m, struct ip *); /* * Fill in IP header. */ if ((flags & (IP_FORWARDING|IP_RAWOUTPUT)) == 0) { ip->ip_v = IPVERSION; ip->ip_off = htons(0); /* ip->ip_id filled in after we find out source ia */ ip->ip_hl = hlen >> 2; IP_STATINC(IP_STAT_LOCALOUT); } else { hlen = ip->ip_hl << 2; } /* * Route packet. */ if (ro == NULL) { memset(&iproute, 0, sizeof(iproute)); ro = &iproute; } sockaddr_in_init(&u.dst4, &ip->ip_dst, 0); dst = satocsin(rtcache_getdst(ro)); /* * 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 (dst && (dst->sin_family != AF_INET || !in_hosteq(dst->sin_addr, ip->ip_dst))) rtcache_free(ro); if ((rt = rtcache_validate(ro)) == NULL && (rt = rtcache_update(ro, 1)) == NULL) { dst = &u.dst4; rtcache_setdst(ro, &u.dst); } /* * If routing to interface only, short circuit routing lookup. */ if (flags & IP_ROUTETOIF) { if ((ia = ifatoia(ifa_ifwithladdr(sintocsa(dst)))) == NULL) { IP_STATINC(IP_STAT_NOROUTE); error = ENETUNREACH; goto bad; } ifp = ia->ia_ifp; mtu = ifp->if_mtu; ip->ip_ttl = 1; } else if ((IN_MULTICAST(ip->ip_dst.s_addr) || ip->ip_dst.s_addr == INADDR_BROADCAST) && imo != NULL && imo->imo_multicast_ifp != NULL) { ifp = imo->imo_multicast_ifp; mtu = ifp->if_mtu; IFP_TO_IA(ifp, ia); } else { if (rt == NULL) rt = rtcache_init(ro); if (rt == NULL) { IP_STATINC(IP_STAT_NOROUTE); error = EHOSTUNREACH; goto bad; } ia = ifatoia(rt->rt_ifa); ifp = rt->rt_ifp; if ((mtu = rt->rt_rmx.rmx_mtu) == 0) mtu = ifp->if_mtu; rt->rt_use++; if (rt->rt_flags & RTF_GATEWAY) dst = satosin(rt->rt_gateway); } rtmtu_nolock = rt && (rt->rt_rmx.rmx_locks & RTV_MTU) == 0; if (IN_MULTICAST(ip->ip_dst.s_addr) || (ip->ip_dst.s_addr == INADDR_BROADCAST)) { bool inmgroup; m->m_flags |= (ip->ip_dst.s_addr == INADDR_BROADCAST) ? M_BCAST : M_MCAST; /* * See if the caller provided any multicast options */ if (imo != NULL) ip->ip_ttl = imo->imo_multicast_ttl; else ip->ip_ttl = IP_DEFAULT_MULTICAST_TTL; /* * if we don't know the outgoing ifp yet, we can't generate * output */ if (!ifp) { IP_STATINC(IP_STAT_NOROUTE); error = ENETUNREACH; goto bad; } /* * If the packet is multicast or broadcast, confirm that * the outgoing interface can transmit it. */ if (((m->m_flags & M_MCAST) && (ifp->if_flags & IFF_MULTICAST) == 0) || ((m->m_flags & M_BCAST) && (ifp->if_flags & (IFF_BROADCAST|IFF_POINTOPOINT)) == 0)) { IP_STATINC(IP_STAT_NOROUTE); error = ENETUNREACH; goto bad; } /* * If source address not specified yet, use an address * of outgoing interface. */ if (in_nullhost(ip->ip_src)) { struct in_ifaddr *xia; struct ifaddr *xifa; IFP_TO_IA(ifp, xia); if (!xia) { error = EADDRNOTAVAIL; goto bad; } xifa = &xia->ia_ifa; if (xifa->ifa_getifa != NULL) { xia = ifatoia((*xifa->ifa_getifa)(xifa, rdst)); } ip->ip_src = xia->ia_addr.sin_addr; } inmgroup = in_multi_group(ip->ip_dst, ifp, flags); if (inmgroup && (imo == NULL || imo->imo_multicast_loop)) { /* * If we belong to the destination multicast group * on the outgoing interface, and the caller did not * forbid loopback, loop back a copy. */ ip_mloopback(ifp, m, &u.dst4); } #ifdef MROUTING else { /* * If we are acting as a multicast router, perform * multicast forwarding as if the packet had just * arrived on the interface to which we are about * to send. The multicast forwarding function * recursively calls this function, using the * IP_FORWARDING flag to prevent infinite recursion. * * Multicasts that are looped back by ip_mloopback(), * above, will be forwarded by the ip_input() routine, * if necessary. */ extern struct socket *ip_mrouter; if (ip_mrouter && (flags & IP_FORWARDING) == 0) { if (ip_mforward(m, ifp) != 0) { m_freem(m); goto done; } } } #endif /* * 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) != 0) { m_freem(m); goto done; } goto sendit; } /* * If source address not specified yet, use address * of outgoing interface. */ if (in_nullhost(ip->ip_src)) { struct ifaddr *xifa; xifa = &ia->ia_ifa; if (xifa->ifa_getifa != NULL) ia = ifatoia((*xifa->ifa_getifa)(xifa, rdst)); ip->ip_src = ia->ia_addr.sin_addr; } /* * packets with Class-D address as source are not valid per * RFC 1112 */ if (IN_MULTICAST(ip->ip_src.s_addr)) { IP_STATINC(IP_STAT_ODROPPED); error = EADDRNOTAVAIL; goto bad; } /* * Look for broadcast address and and verify user is allowed to * send such a packet. */ if (in_broadcast(dst->sin_addr, ifp)) { if ((ifp->if_flags & IFF_BROADCAST) == 0) { error = EADDRNOTAVAIL; goto bad; } if ((flags & IP_ALLOWBROADCAST) == 0) { error = EACCES; goto bad; } /* don't allow broadcast messages to be fragmented */ if (ntohs(ip->ip_len) > ifp->if_mtu) { error = EMSGSIZE; goto bad; } m->m_flags |= M_BCAST; } else m->m_flags &= ~M_BCAST; sendit: if ((flags & (IP_FORWARDING|IP_NOIPNEWID)) == 0) { if (m->m_pkthdr.len < IP_MINFRAGSIZE) { ip->ip_id = 0; } else if ((m->m_pkthdr.csum_flags & M_CSUM_TSOv4) == 0) { ip->ip_id = ip_newid(ia); } else { /* * TSO capable interfaces (typically?) increment * ip_id for each segment. * "allocate" enough ids here to increase the chance * for them to be unique. * * note that the following calculation is not * needed to be precise. wasting some ip_id is fine. */ unsigned int segsz = m->m_pkthdr.segsz; unsigned int datasz = ntohs(ip->ip_len) - hlen; unsigned int num = howmany(datasz, segsz); ip->ip_id = ip_newid_range(ia, num); } } /* * If we're doing Path MTU Discovery, we need to set DF unless * the route's MTU is locked. */ if ((flags & IP_MTUDISC) != 0 && rtmtu_nolock) { ip->ip_off |= htons(IP_DF); } #ifdef IPSEC if (ipsec_used) { bool ipsec_done = false; /* Perform IPsec processing, if any. */ error = ipsec4_output(m, so, flags, &sp, &mtu, &natt_frag, &ipsec_done); if (error || ipsec_done) goto done; } #endif /* * Run through list of hooks for output packets. */ error = pfil_run_hooks(inet_pfil_hook, &m, ifp, PFIL_OUT); if (error) goto done; if (m == NULL) goto done; ip = mtod(m, struct ip *); hlen = ip->ip_hl << 2; m->m_pkthdr.csum_data |= hlen << 16; #if IFA_STATS /* * search for the source address structure to * maintain output statistics. */ INADDR_TO_IA(ip->ip_src, ia); #endif /* Maybe skip checksums on loopback interfaces. */ if (IN_NEED_CHECKSUM(ifp, M_CSUM_IPv4)) { m->m_pkthdr.csum_flags |= M_CSUM_IPv4; } sw_csum = m->m_pkthdr.csum_flags & ~ifp->if_csum_flags_tx; /* * If small enough for mtu of path, or if using TCP segmentation * offload, can just send directly. */ if (ntohs(ip->ip_len) <= mtu || (m->m_pkthdr.csum_flags & M_CSUM_TSOv4) != 0) { const struct sockaddr *sa; #if IFA_STATS if (ia) ia->ia_ifa.ifa_data.ifad_outbytes += ntohs(ip->ip_len); #endif /* * Always initialize the sum to 0! Some HW assisted * checksumming requires this. */ ip->ip_sum = 0; if ((m->m_pkthdr.csum_flags & M_CSUM_TSOv4) == 0) { /* * Perform any checksums that the hardware can't do * for us. * * XXX Does any hardware require the {th,uh}_sum * XXX fields to be 0? */ if (sw_csum & M_CSUM_IPv4) { KASSERT(IN_NEED_CHECKSUM(ifp, M_CSUM_IPv4)); ip->ip_sum = in_cksum(m, hlen); m->m_pkthdr.csum_flags &= ~M_CSUM_IPv4; } if (sw_csum & (M_CSUM_TCPv4|M_CSUM_UDPv4)) { if (IN_NEED_CHECKSUM(ifp, sw_csum & (M_CSUM_TCPv4|M_CSUM_UDPv4))) { in_delayed_cksum(m); } m->m_pkthdr.csum_flags &= ~(M_CSUM_TCPv4|M_CSUM_UDPv4); } } sa = (m->m_flags & M_MCAST) ? sintocsa(rdst) : sintocsa(dst); if (__predict_true( (m->m_pkthdr.csum_flags & M_CSUM_TSOv4) == 0 || (ifp->if_capenable & IFCAP_TSOv4) != 0)) { KERNEL_LOCK(1, NULL); error = (*ifp->if_output)(ifp, m, sa, rt); KERNEL_UNLOCK_ONE(NULL); } else { error = ip_tso_output(ifp, m, sa, rt); } goto done; } /* * We can't use HW checksumming if we're about to * to fragment the packet. * * XXX Some hardware can do this. */ if (m->m_pkthdr.csum_flags & (M_CSUM_TCPv4|M_CSUM_UDPv4)) { if (IN_NEED_CHECKSUM(ifp, m->m_pkthdr.csum_flags & (M_CSUM_TCPv4|M_CSUM_UDPv4))) { in_delayed_cksum(m); } m->m_pkthdr.csum_flags &= ~(M_CSUM_TCPv4|M_CSUM_UDPv4); } /* * Too large for interface; fragment if possible. * Must be able to put at least 8 bytes per fragment. */ if (ntohs(ip->ip_off) & IP_DF) { if (flags & IP_RETURNMTU) { struct inpcb *inp; KASSERT(so && solocked(so)); inp = sotoinpcb(so); inp->inp_errormtu = mtu; } error = EMSGSIZE; IP_STATINC(IP_STAT_CANTFRAG); goto bad; } error = ip_fragment(m, ifp, mtu); if (error) { m = NULL; goto bad; } for (; m; m = m0) { m0 = m->m_nextpkt; m->m_nextpkt = 0; if (error) { m_freem(m); continue; } #if IFA_STATS if (ia) ia->ia_ifa.ifa_data.ifad_outbytes += ntohs(ip->ip_len); #endif /* * If we get there, the packet has not been handled by * IPsec whereas it should have. Now that it has been * fragmented, re-inject it in ip_output so that IPsec * processing can occur. */ if (natt_frag) { error = ip_output(m, opt, ro, flags | IP_RAWOUTPUT | IP_NOIPNEWID, imo, so); } else { KASSERT((m->m_pkthdr.csum_flags & (M_CSUM_UDPv4 | M_CSUM_TCPv4)) == 0); KERNEL_LOCK(1, NULL); error = (*ifp->if_output)(ifp, m, (m->m_flags & M_MCAST) ? sintocsa(rdst) : sintocsa(dst), rt); KERNEL_UNLOCK_ONE(NULL); } } if (error == 0) { IP_STATINC(IP_STAT_FRAGMENTED); } done: if (ro == &iproute) { rtcache_free(&iproute); } #ifdef IPSEC if (sp) { KEY_FREESP(&sp); } #endif return error; bad: m_freem(m); goto done; } int ip_fragment(struct mbuf *m, struct ifnet *ifp, u_long mtu) { struct ip *ip, *mhip; struct mbuf *m0; int len, hlen, off; int mhlen, firstlen; struct mbuf **mnext; int sw_csum = m->m_pkthdr.csum_flags; int fragments = 0; int s; int error = 0; ip = mtod(m, struct ip *); hlen = ip->ip_hl << 2; if (ifp != NULL) sw_csum &= ~ifp->if_csum_flags_tx; len = (mtu - hlen) &~ 7; if (len < 8) { m_freem(m); return (EMSGSIZE); } firstlen = len; mnext = &m->m_nextpkt; /* * 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 < ntohs(ip->ip_len); off += len) { MGETHDR(m, M_DONTWAIT, MT_HEADER); if (m == 0) { error = ENOBUFS; IP_STATINC(IP_STAT_ODROPPED); goto sendorfree; } MCLAIM(m, m0->m_owner); *mnext = m; mnext = &m->m_nextpkt; m->m_data += max_linkhdr; mhip = mtod(m, struct ip *); *mhip = *ip; /* we must inherit MCAST and BCAST flags */ m->m_flags |= m0->m_flags & (M_MCAST|M_BCAST); if (hlen > sizeof (struct ip)) { mhlen = ip_optcopy(ip, mhip) + sizeof (struct ip); mhip->ip_hl = mhlen >> 2; } m->m_len = mhlen; mhip->ip_off = ((off - hlen) >> 3) + (ntohs(ip->ip_off) & ~IP_MF); if (ip->ip_off & htons(IP_MF)) mhip->ip_off |= IP_MF; if (off + len >= ntohs(ip->ip_len)) len = ntohs(ip->ip_len) - off; else mhip->ip_off |= IP_MF; HTONS(mhip->ip_off); mhip->ip_len = htons((u_int16_t)(len + mhlen)); m->m_next = m_copym(m0, off, len, M_DONTWAIT); if (m->m_next == 0) { error = ENOBUFS; /* ??? */ IP_STATINC(IP_STAT_ODROPPED); goto sendorfree; } m->m_pkthdr.len = mhlen + len; m->m_pkthdr.rcvif = NULL; mhip->ip_sum = 0; KASSERT((m->m_pkthdr.csum_flags & M_CSUM_IPv4) == 0); if (sw_csum & M_CSUM_IPv4) { mhip->ip_sum = in_cksum(m, mhlen); } else { /* * checksum is hw-offloaded or not necessary. */ m->m_pkthdr.csum_flags |= m0->m_pkthdr.csum_flags & M_CSUM_IPv4; m->m_pkthdr.csum_data |= mhlen << 16; KASSERT(!(ifp != NULL && IN_NEED_CHECKSUM(ifp, M_CSUM_IPv4)) || (m->m_pkthdr.csum_flags & M_CSUM_IPv4) != 0); } IP_STATINC(IP_STAT_OFRAGMENTS); fragments++; } /* * 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 - ntohs(ip->ip_len)); m->m_pkthdr.len = hlen + firstlen; ip->ip_len = htons((u_int16_t)m->m_pkthdr.len); ip->ip_off |= htons(IP_MF); ip->ip_sum = 0; if (sw_csum & M_CSUM_IPv4) { ip->ip_sum = in_cksum(m, hlen); m->m_pkthdr.csum_flags &= ~M_CSUM_IPv4; } else { /* * checksum is hw-offloaded or not necessary. */ KASSERT(!(ifp != NULL && IN_NEED_CHECKSUM(ifp, M_CSUM_IPv4)) || (m->m_pkthdr.csum_flags & M_CSUM_IPv4) != 0); KASSERT(M_CSUM_DATA_IPv4_IPHL(m->m_pkthdr.csum_data) >= sizeof(struct ip)); } sendorfree: /* * If there is no room for all the fragments, don't queue * any of them. */ if (ifp != NULL) { s = splnet(); if (ifp->if_snd.ifq_maxlen - ifp->if_snd.ifq_len < fragments && error == 0) { error = ENOBUFS; IP_STATINC(IP_STAT_ODROPPED); IFQ_INC_DROPS(&ifp->if_snd); } splx(s); } if (error) { for (m = m0; m; m = m0) { m0 = m->m_nextpkt; m->m_nextpkt = NULL; m_freem(m); } } return (error); } /* * Process a delayed payload checksum calculation. */ void in_delayed_cksum(struct mbuf *m) { struct ip *ip; u_int16_t csum, offset; ip = mtod(m, struct ip *); offset = ip->ip_hl << 2; csum = in4_cksum(m, 0, offset, ntohs(ip->ip_len) - offset); if (csum == 0 && (m->m_pkthdr.csum_flags & M_CSUM_UDPv4) != 0) csum = 0xffff; offset += M_CSUM_DATA_IPv4_OFFSET(m->m_pkthdr.csum_data); if ((offset + sizeof(u_int16_t)) > m->m_len) { /* This happen when ip options were inserted printf("in_delayed_cksum: pullup len %d off %d proto %d\n", m->m_len, offset, ip->ip_p); */ m_copyback(m, offset, sizeof(csum), (void *) &csum); } else *(u_int16_t *)(mtod(m, char *) + offset) = csum; } /* * Determine the maximum length of the options to be inserted; * we would far rather allocate too much space rather than too little. */ u_int ip_optlen(struct inpcb *inp) { struct mbuf *m = inp->inp_options; if (m && m->m_len > offsetof(struct ipoption, ipopt_dst)) { return (m->m_len - offsetof(struct ipoption, ipopt_dst)); } return 0; } /* * 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. */ 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 + ntohs(ip->ip_len) > IP_MAXPACKET) return (m); /* XXX should fail */ if (!in_nullhost(p->ipopt_dst)) ip->ip_dst = p->ipopt_dst; if (M_READONLY(m) || M_LEADINGSPACE(m) < optlen) { MGETHDR(n, M_DONTWAIT, MT_HEADER); if (n == 0) return (m); MCLAIM(n, m->m_owner); M_MOVE_PKTHDR(n, m); 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; bcopy((void *)ip, mtod(m, void *), sizeof(struct ip)); } else { m->m_data -= optlen; m->m_len += optlen; memmove(mtod(m, void *), ip, sizeof(struct ip)); } m->m_pkthdr.len += optlen; ip = mtod(m, struct ip *); bcopy((void *)p->ipopt_list, (void *)(ip + 1), (unsigned)optlen); *phlen = sizeof(struct ip) + optlen; ip->ip_len = htons(ntohs(ip->ip_len) + optlen); return (m); } /* * Copy options from ip to jp, * omitting those not copied during fragmentation. */ 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->ip_hl << 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; } KASSERT(cnt >= IPOPT_OLEN + sizeof(*cp)); optlen = cp[IPOPT_OLEN]; KASSERT(optlen >= IPOPT_OLEN + sizeof(*cp) && optlen < cnt); /* Invalid lengths should have been caught by ip_dooptions. */ if (optlen > cnt) optlen = cnt; if (IPOPT_COPIED(opt)) { bcopy((void *)cp, (void *)dp, (unsigned)optlen); dp += optlen; } } for (optlen = dp - (u_char *)(jp+1); optlen & 0x3; optlen++) *dp++ = IPOPT_EOL; return (optlen); } /* * IP socket option processing. */ int ip_ctloutput(int op, struct socket *so, struct sockopt *sopt) { struct inpcb *inp = sotoinpcb(so); struct ip *ip = &inp->inp_ip; int inpflags = inp->inp_flags; int optval = 0, error = 0; if (sopt->sopt_level != IPPROTO_IP) { if (sopt->sopt_level == SOL_SOCKET && sopt->sopt_name == SO_NOHEADER) return 0; return ENOPROTOOPT; } switch (op) { case PRCO_SETOPT: switch (sopt->sopt_name) { case IP_OPTIONS: #ifdef notyet case IP_RETOPTS: #endif error = ip_pcbopts(inp, sopt); break; case IP_TOS: case IP_TTL: case IP_MINTTL: case IP_PKTINFO: case IP_RECVOPTS: case IP_RECVRETOPTS: case IP_RECVDSTADDR: case IP_RECVIF: case IP_RECVPKTINFO: case IP_RECVTTL: error = sockopt_getint(sopt, &optval); if (error) break; switch (sopt->sopt_name) { case IP_TOS: ip->ip_tos = optval; break; case IP_TTL: ip->ip_ttl = optval; break; case IP_MINTTL: if (optval > 0 && optval <= MAXTTL) inp->inp_ip_minttl = optval; else error = EINVAL; break; #define OPTSET(bit) \ if (optval) \ inpflags |= bit; \ else \ inpflags &= ~bit; case IP_PKTINFO: OPTSET(INP_PKTINFO); break; case IP_RECVOPTS: OPTSET(INP_RECVOPTS); break; case IP_RECVPKTINFO: OPTSET(INP_RECVPKTINFO); 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; } break; #undef OPTSET case IP_MULTICAST_IF: case IP_MULTICAST_TTL: case IP_MULTICAST_LOOP: case IP_ADD_MEMBERSHIP: case IP_DROP_MEMBERSHIP: error = ip_setmoptions(inp, sopt); break; case IP_PORTRANGE: error = sockopt_getint(sopt, &optval); if (error) break; switch (optval) { case IP_PORTRANGE_DEFAULT: case IP_PORTRANGE_HIGH: inpflags &= ~(INP_LOWPORT); break; case IP_PORTRANGE_LOW: inpflags |= INP_LOWPORT; break; default: error = EINVAL; break; } break; case IP_PORTALGO: error = sockopt_getint(sopt, &optval); if (error) break; error = portalgo_algo_index_select( (struct inpcb_hdr *)inp, optval); break; #if defined(IPSEC) case IP_IPSEC_POLICY: if (ipsec_enabled) { error = ipsec4_set_policy(inp, sopt->sopt_name, sopt->sopt_data, sopt->sopt_size, curlwp->l_cred); break; } /*FALLTHROUGH*/ #endif /* IPSEC */ default: error = ENOPROTOOPT; break; } break; case PRCO_GETOPT: switch (sopt->sopt_name) { case IP_OPTIONS: case IP_RETOPTS: { struct mbuf *mopts = inp->inp_options; if (mopts) { struct mbuf *m; m = m_copym(mopts, 0, M_COPYALL, M_DONTWAIT); if (m == NULL) { error = ENOBUFS; break; } error = sockopt_setmbuf(sopt, m); } break; } case IP_PKTINFO: case IP_TOS: case IP_TTL: case IP_MINTTL: case IP_RECVOPTS: case IP_RECVRETOPTS: case IP_RECVDSTADDR: case IP_RECVIF: case IP_RECVPKTINFO: case IP_RECVTTL: case IP_ERRORMTU: switch (sopt->sopt_name) { case IP_TOS: optval = ip->ip_tos; break; case IP_TTL: optval = ip->ip_ttl; break; case IP_MINTTL: optval = inp->inp_ip_minttl; break; case IP_ERRORMTU: optval = inp->inp_errormtu; break; #define OPTBIT(bit) (inpflags & bit ? 1 : 0) case IP_PKTINFO: optval = OPTBIT(INP_PKTINFO); break; case IP_RECVOPTS: optval = OPTBIT(INP_RECVOPTS); break; case IP_RECVPKTINFO: optval = OPTBIT(INP_RECVPKTINFO); 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; } error = sockopt_setint(sopt, optval); break; #if 0 /* defined(IPSEC) */ case IP_IPSEC_POLICY: { struct mbuf *m = NULL; /* XXX this will return EINVAL as sopt is empty */ error = ipsec4_get_policy(inp, sopt->sopt_data, sopt->sopt_size, &m); if (error == 0) error = sockopt_setmbuf(sopt, m); break; } #endif /*IPSEC*/ case IP_MULTICAST_IF: case IP_MULTICAST_TTL: case IP_MULTICAST_LOOP: case IP_ADD_MEMBERSHIP: case IP_DROP_MEMBERSHIP: error = ip_getmoptions(inp, sopt); break; case IP_PORTRANGE: if (inpflags & INP_LOWPORT) optval = IP_PORTRANGE_LOW; else optval = IP_PORTRANGE_DEFAULT; error = sockopt_setint(sopt, optval); break; case IP_PORTALGO: optval = inp->inp_portalgo; error = sockopt_setint(sopt, optval); break; default: error = ENOPROTOOPT; break; } break; } if (!error) { inp->inp_flags = inpflags; } 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(struct inpcb *inp, const struct sockopt *sopt) { struct mbuf *m; const u_char *cp; u_char *dp; int cnt; /* Turn off any old options. */ if (inp->inp_options) { m_free(inp->inp_options); } inp->inp_options = NULL; if ((cnt = sopt->sopt_size) == 0) { /* Only turning off any previous options. */ return 0; } cp = sopt->sopt_data; #ifndef __vax__ if (cnt % sizeof(int32_t)) return (EINVAL); #endif m = m_get(M_DONTWAIT, MT_SOOPTS); if (m == NULL) return (ENOBUFS); dp = mtod(m, u_char *); memset(dp, 0, sizeof(struct in_addr)); dp += sizeof(struct in_addr); m->m_len = sizeof(struct in_addr); /* * IP option list according to RFC791. Each option is of the form * * [optval] [olen] [(olen - 2) data bytes] * * We validate the list and copy options to an mbuf for prepending * to data packets. The IP first-hop destination address will be * stored before actual options and is zero if unset. */ while (cnt > 0) { uint8_t optval, olen, offset; optval = cp[IPOPT_OPTVAL]; if (optval == IPOPT_EOL || optval == IPOPT_NOP) { olen = 1; } else { if (cnt < IPOPT_OLEN + 1) goto bad; olen = cp[IPOPT_OLEN]; if (olen < IPOPT_OLEN + 1 || olen > cnt) goto bad; } if (optval == IPOPT_LSRR || optval == 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 (olen < IPOPT_OFFSET + 1 + sizeof(struct in_addr)) goto bad; offset = cp[IPOPT_OFFSET]; memcpy(mtod(m, u_char *), cp + IPOPT_OFFSET + 1, sizeof(struct in_addr)); cp += sizeof(struct in_addr); cnt -= sizeof(struct in_addr); olen -= sizeof(struct in_addr); if (m->m_len + olen > MAX_IPOPTLEN + sizeof(struct in_addr)) goto bad; memcpy(dp, cp, olen); dp[IPOPT_OPTVAL] = optval; dp[IPOPT_OLEN] = olen; dp[IPOPT_OFFSET] = offset; break; } else { if (m->m_len + olen > MAX_IPOPTLEN + sizeof(struct in_addr)) goto bad; memcpy(dp, cp, olen); break; } dp += olen; m->m_len += olen; if (optval == IPOPT_EOL) break; cp += olen; cnt -= olen; } inp->inp_options = m; return 0; bad: (void)m_free(m); return EINVAL; } /* * following RFC1724 section 3.3, 0.0.0.0/8 is interpreted as interface index. */ static struct ifnet * ip_multicast_if(struct in_addr *a, int *ifindexp) { int ifindex; struct ifnet *ifp = NULL; struct in_ifaddr *ia; if (ifindexp) *ifindexp = 0; if (ntohl(a->s_addr) >> 24 == 0) { ifindex = ntohl(a->s_addr) & 0xffffff; ifp = if_byindex(ifindex); if (!ifp) return NULL; if (ifindexp) *ifindexp = ifindex; } else { LIST_FOREACH(ia, &IN_IFADDR_HASH(a->s_addr), ia_hash) { if (in_hosteq(ia->ia_addr.sin_addr, *a) && (ia->ia_ifp->if_flags & IFF_MULTICAST) != 0) { ifp = ia->ia_ifp; break; } } } return ifp; } static int ip_getoptval(const struct sockopt *sopt, u_int8_t *val, u_int maxval) { u_int tval; u_char cval; int error; if (sopt == NULL) return EINVAL; switch (sopt->sopt_size) { case sizeof(u_char): error = sockopt_get(sopt, &cval, sizeof(u_char)); tval = cval; break; case sizeof(u_int): error = sockopt_get(sopt, &tval, sizeof(u_int)); break; default: error = EINVAL; } if (error) return error; if (tval > maxval) return EINVAL; *val = tval; return 0; } /* * Set the IP multicast options in response to user setsockopt(). */ static int ip_setmoptions(struct inpcb *inp, const struct sockopt *sopt) { struct ip_moptions *imo = inp->inp_moptions; struct in_addr addr; struct ip_mreq lmreq, *mreq; struct ifnet *ifp; int i, ifindex, error = 0; if (!imo) { /* * No multicast option buffer attached to the pcb; * allocate one and initialize to default values. */ imo = kmem_intr_alloc(sizeof(*imo), KM_NOSLEEP); if (imo == NULL) return ENOBUFS; imo->imo_multicast_ifp = NULL; imo->imo_multicast_addr.s_addr = INADDR_ANY; imo->imo_multicast_ttl = IP_DEFAULT_MULTICAST_TTL; imo->imo_multicast_loop = IP_DEFAULT_MULTICAST_LOOP; imo->imo_num_memberships = 0; inp->inp_moptions = imo; } switch (sopt->sopt_name) { case IP_MULTICAST_IF: /* * Select the interface for outgoing multicast packets. */ error = sockopt_get(sopt, &addr, sizeof(addr)); if (error) break; /* * INADDR_ANY is used to remove a previous selection. * When no interface is selected, a default one is * chosen every time a multicast packet is sent. */ if (in_nullhost(addr)) { imo->imo_multicast_ifp = NULL; break; } /* * The selected interface is identified by its local * IP address. Find the interface and confirm that * it supports multicasting. */ ifp = ip_multicast_if(&addr, &ifindex); if (ifp == NULL || (ifp->if_flags & IFF_MULTICAST) == 0) { error = EADDRNOTAVAIL; break; } imo->imo_multicast_ifp = ifp; if (ifindex) imo->imo_multicast_addr = addr; else imo->imo_multicast_addr.s_addr = INADDR_ANY; break; case IP_MULTICAST_TTL: /* * Set the IP time-to-live for outgoing multicast packets. */ error = ip_getoptval(sopt, &imo->imo_multicast_ttl, MAXTTL); break; case IP_MULTICAST_LOOP: /* * Set the loopback flag for outgoing multicast packets. * Must be zero or one. */ error = ip_getoptval(sopt, &imo->imo_multicast_loop, 1); break; case IP_ADD_MEMBERSHIP: /* * Add a multicast group membership. * Group must be a valid IP multicast address. */ error = sockopt_get(sopt, &lmreq, sizeof(lmreq)); if (error) break; mreq = &lmreq; if (!IN_MULTICAST(mreq->imr_multiaddr.s_addr)) { error = EINVAL; break; } /* * If no interface address was provided, use the interface of * the route to the given multicast address. */ if (in_nullhost(mreq->imr_interface)) { struct rtentry *rt; union { struct sockaddr dst; struct sockaddr_in dst4; } u; struct route ro; memset(&ro, 0, sizeof(ro)); sockaddr_in_init(&u.dst4, &mreq->imr_multiaddr, 0); rtcache_setdst(&ro, &u.dst); ifp = (rt = rtcache_init(&ro)) != NULL ? rt->rt_ifp : NULL; rtcache_free(&ro); } else { ifp = ip_multicast_if(&mreq->imr_interface, NULL); } /* * See if we found an interface, and confirm that it * supports multicast. */ if (ifp == NULL || (ifp->if_flags & IFF_MULTICAST) == 0) { error = EADDRNOTAVAIL; break; } /* * See if the membership already exists or if all the * membership slots are full. */ for (i = 0; i < imo->imo_num_memberships; ++i) { if (imo->imo_membership[i]->inm_ifp == ifp && in_hosteq(imo->imo_membership[i]->inm_addr, mreq->imr_multiaddr)) break; } if (i < imo->imo_num_memberships) { error = EADDRINUSE; break; } if (i == IP_MAX_MEMBERSHIPS) { error = ETOOMANYREFS; break; } /* * Everything looks good; add a new record to the multicast * address list for the given interface. */ if ((imo->imo_membership[i] = in_addmulti(&mreq->imr_multiaddr, ifp)) == NULL) { error = ENOBUFS; break; } ++imo->imo_num_memberships; break; case IP_DROP_MEMBERSHIP: /* * Drop a multicast group membership. * Group must be a valid IP multicast address. */ error = sockopt_get(sopt, &lmreq, sizeof(lmreq)); if (error) break; mreq = &lmreq; if (!IN_MULTICAST(mreq->imr_multiaddr.s_addr)) { error = EINVAL; break; } /* * If an interface address was specified, get a pointer * to its ifnet structure. */ if (in_nullhost(mreq->imr_interface)) ifp = NULL; else { ifp = ip_multicast_if(&mreq->imr_interface, NULL); if (ifp == NULL) { error = EADDRNOTAVAIL; break; } } /* * Find the membership in the membership array. */ for (i = 0; i < imo->imo_num_memberships; ++i) { if ((ifp == NULL || imo->imo_membership[i]->inm_ifp == ifp) && in_hosteq(imo->imo_membership[i]->inm_addr, mreq->imr_multiaddr)) break; } if (i == imo->imo_num_memberships) { error = EADDRNOTAVAIL; break; } /* * Give up the multicast address record to which the * membership points. */ in_delmulti(imo->imo_membership[i]); /* * Remove the gap in the membership array. */ for (++i; i < imo->imo_num_memberships; ++i) imo->imo_membership[i-1] = imo->imo_membership[i]; --imo->imo_num_memberships; break; default: error = EOPNOTSUPP; break; } /* * If all options have default values, no need to keep the mbuf. */ if (imo->imo_multicast_ifp == NULL && imo->imo_multicast_ttl == IP_DEFAULT_MULTICAST_TTL && imo->imo_multicast_loop == IP_DEFAULT_MULTICAST_LOOP && imo->imo_num_memberships == 0) { kmem_free(imo, sizeof(*imo)); inp->inp_moptions = NULL; } return error; } /* * Return the IP multicast options in response to user getsockopt(). */ static int ip_getmoptions(struct inpcb *inp, struct sockopt *sopt) { struct ip_moptions *imo = inp->inp_moptions; struct in_addr addr; struct in_ifaddr *ia; uint8_t optval; int error = 0; switch (sopt->sopt_name) { case IP_MULTICAST_IF: if (imo == NULL || imo->imo_multicast_ifp == NULL) addr = zeroin_addr; else if (imo->imo_multicast_addr.s_addr) { /* return the value user has set */ addr = imo->imo_multicast_addr; } else { IFP_TO_IA(imo->imo_multicast_ifp, ia); addr = ia ? ia->ia_addr.sin_addr : zeroin_addr; } error = sockopt_set(sopt, &addr, sizeof(addr)); break; case IP_MULTICAST_TTL: optval = imo ? imo->imo_multicast_ttl : IP_DEFAULT_MULTICAST_TTL; error = sockopt_set(sopt, &optval, sizeof(optval)); break; case IP_MULTICAST_LOOP: optval = imo ? imo->imo_multicast_loop : IP_DEFAULT_MULTICAST_LOOP; error = sockopt_set(sopt, &optval, sizeof(optval)); break; default: error = EOPNOTSUPP; } return error; } /* * Discard the IP multicast options. */ void ip_freemoptions(struct ip_moptions *imo) { int i; if (imo != NULL) { for (i = 0; i < imo->imo_num_memberships; ++i) in_delmulti(imo->imo_membership[i]); kmem_free(imo, sizeof(*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 lo0ifp -- easier than replicating that code here. */ static void ip_mloopback(struct ifnet *ifp, struct mbuf *m, const struct sockaddr_in *dst) { struct ip *ip; struct mbuf *copym; copym = m_copypacket(m, M_DONTWAIT); if (copym != NULL && (copym->m_flags & M_EXT || copym->m_len < sizeof(struct ip))) copym = m_pullup(copym, sizeof(struct ip)); 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 (copym->m_pkthdr.csum_flags & (M_CSUM_TCPv4|M_CSUM_UDPv4)) { in_delayed_cksum(copym); copym->m_pkthdr.csum_flags &= ~(M_CSUM_TCPv4|M_CSUM_UDPv4); } ip->ip_sum = 0; ip->ip_sum = in_cksum(copym, ip->ip_hl << 2); KERNEL_LOCK(1, NULL); (void)looutput(ifp, copym, sintocsa(dst), NULL); KERNEL_UNLOCK_ONE(NULL); }