/* $NetBSD: ip_output.c,v 1.314 2019/06/05 01:31:04 knakahara 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 1.314 2019/06/05 01:31:04 knakahara Exp $"); #ifdef _KERNEL_OPT #include "opt_inet.h" #include "opt_ipsec.h" #include "opt_mrouting.h" #include "opt_net_mpsafe.h" #include "opt_mpls.h" #endif #include "arp.h" #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #ifdef INET6 #include #endif #ifdef MROUTING #include #endif #ifdef IPSEC #include #include #endif #ifdef MPLS #include #include #endif 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_ifaddrvalid(const struct in_ifaddr *); extern pfil_head_t *inet_pfil_hook; /* XXX */ int ip_do_loopback_cksum = 0; static int ip_mark_mpls(struct ifnet * const ifp, struct mbuf * const m, const struct rtentry *rt) { int error = 0; #ifdef MPLS union mpls_shim msh; if (rt == NULL || rt_gettag(rt) == NULL || rt_gettag(rt)->sa_family != AF_MPLS || (m->m_flags & (M_MCAST | M_BCAST)) != 0 || ifp->if_type != IFT_ETHER) return 0; msh.s_addr = MPLS_GETSADDR(rt); if (msh.shim.label != MPLS_LABEL_IMPLNULL) { struct m_tag *mtag; /* * XXX tentative solution to tell ether_output * it's MPLS. Need some more efficient solution. */ mtag = m_tag_get(PACKET_TAG_MPLS, sizeof(int) /* dummy */, M_NOWAIT); if (mtag == NULL) return ENOMEM; m_tag_prepend(m, mtag); } #endif return error; } /* * Send an IP packet to a host. */ int ip_if_output(struct ifnet * const ifp, struct mbuf * const m, const struct sockaddr * const dst, const struct rtentry *rt) { int error = 0; if (rt != NULL) { error = rt_check_reject_route(rt, ifp); if (error != 0) { m_freem(m); return error; } } error = ip_mark_mpls(ifp, m, rt); if (error != 0) { m_freem(m); return error; } error = if_output_lock(ifp, ifp, m, dst, rt); return error; } /* * IP output. The packet in mbuf chain m contains a skeletal IP * header (with len, off, ttl, proto, tos, src, dst). * The mbuf chain containing the packet will be freed. * The mbuf opt, if present, will not be freed. */ int ip_output(struct mbuf *m0, struct mbuf *opt, struct route *ro, int flags, struct ip_moptions *imo, struct inpcb *inp) { struct rtentry *rt; struct ip *ip; struct ifnet *ifp, *mifp = NULL; struct mbuf *m = m0; int len, hlen, error = 0; struct route iproute; const struct sockaddr_in *dst; struct in_ifaddr *ia = NULL; struct ifaddr *ifa; int isbroadcast; int sw_csum; u_long mtu; bool natt_frag = false; bool rtmtu_nolock; union { struct sockaddr sa; struct sockaddr_in sin; } udst, usrc; struct sockaddr *rdst = &udst.sa; /* real IP destination, as * opposed to the nexthop */ struct psref psref, psref_ia; int bound; bool bind_need_restore = false; len = 0; 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)); KASSERT(m->m_len >= sizeof(struct ip)); hlen = sizeof(struct ip); if (opt) { m = ip_insertoptions(m, opt, &len); 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(&udst.sin, &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); /* XXX must be before rtcache operations */ bound = curlwp_bind(); bind_need_restore = true; if ((rt = rtcache_validate(ro)) == NULL && (rt = rtcache_update(ro, 1)) == NULL) { dst = &udst.sin; error = rtcache_setdst(ro, &udst.sa); if (error != 0) goto bad; } /* * If routing to interface only, short circuit routing lookup. */ if (flags & IP_ROUTETOIF) { ifa = ifa_ifwithladdr_psref(sintocsa(dst), &psref_ia); if (ifa == NULL) { IP_STATINC(IP_STAT_NOROUTE); error = ENETUNREACH; goto bad; } /* ia is already referenced by psref_ia */ ia = ifatoia(ifa); ifp = ia->ia_ifp; mtu = ifp->if_mtu; ip->ip_ttl = 1; isbroadcast = in_broadcast(dst->sin_addr, ifp); } else if (((IN_MULTICAST(ip->ip_dst.s_addr) || ip->ip_dst.s_addr == INADDR_BROADCAST) || (flags & IP_ROUTETOIFINDEX)) && imo != NULL && imo->imo_multicast_if_index != 0) { ifp = mifp = if_get_byindex(imo->imo_multicast_if_index, &psref); if (ifp == NULL) { IP_STATINC(IP_STAT_NOROUTE); error = ENETUNREACH; goto bad; } mtu = ifp->if_mtu; ia = in_get_ia_from_ifp_psref(ifp, &psref_ia); if (ia == NULL) { error = EADDRNOTAVAIL; goto bad; } if (IN_MULTICAST(ip->ip_dst.s_addr) || ip->ip_dst.s_addr == INADDR_BROADCAST) { isbroadcast = 0; } else { /* IP_ROUTETOIFINDEX */ isbroadcast = in_broadcast(dst->sin_addr, ifp); if ((isbroadcast == 0) && ((ifp->if_flags & (IFF_LOOPBACK | IFF_POINTOPOINT)) == 0) && (in_direct(dst->sin_addr, ifp) == 0)) { /* gateway address required */ if (rt == NULL) rt = rtcache_init(ro); if (rt == NULL || rt->rt_ifp != ifp) { IP_STATINC(IP_STAT_NOROUTE); error = EHOSTUNREACH; goto bad; } rt->rt_use++; if (rt->rt_flags & RTF_GATEWAY) dst = satosin(rt->rt_gateway); if (rt->rt_flags & RTF_HOST) isbroadcast = rt->rt_flags & RTF_BROADCAST; } } } else { if (rt == NULL) rt = rtcache_init(ro); if (rt == NULL) { IP_STATINC(IP_STAT_NOROUTE); error = EHOSTUNREACH; goto bad; } if (ifa_is_destroying(rt->rt_ifa)) { rtcache_unref(rt, ro); rt = NULL; IP_STATINC(IP_STAT_NOROUTE); error = EHOSTUNREACH; goto bad; } ifa_acquire(rt->rt_ifa, &psref_ia); 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); if (rt->rt_flags & RTF_HOST) isbroadcast = rt->rt_flags & RTF_BROADCAST; else isbroadcast = in_broadcast(dst->sin_addr, ifp); } 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; struct psref _psref; xia = in_get_ia_from_ifp_psref(ifp, &_psref); if (!xia) { error = EADDRNOTAVAIL; goto bad; } xifa = &xia->ia_ifa; if (xifa->ifa_getifa != NULL) { ia4_release(xia, &_psref); /* FIXME ifa_getifa is NOMPSAFE */ xia = ifatoia((*xifa->ifa_getifa)(xifa, rdst)); if (xia == NULL) { error = EADDRNOTAVAIL; goto bad; } ia4_acquire(xia, &_psref); } ip->ip_src = xia->ia_addr.sin_addr; ia4_release(xia, &_psref); } 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, &udst.sin); } #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) { ia4_release(ia, &psref_ia); /* FIXME ifa_getifa is NOMPSAFE */ ia = ifatoia((*xifa->ifa_getifa)(xifa, rdst)); if (ia == NULL) { error = EADDRNOTAVAIL; goto bad; } ia4_acquire(ia, &psref_ia); } ip->ip_src = ia->ia_addr.sin_addr; } /* * Packets with Class-D address as source are not valid per * RFC1112. */ if (IN_MULTICAST(ip->ip_src.s_addr)) { IP_STATINC(IP_STAT_ODROPPED); error = EADDRNOTAVAIL; goto bad; } /* * Look for broadcast address and verify user is allowed to * send such a packet. */ if (isbroadcast) { if ((ifp->if_flags & IFF_BROADCAST) == 0) { error = EADDRNOTAVAIL; goto bad; } if ((flags & IP_ALLOWBROADCAST) == 0) { error = EACCES; goto bad; } /* don't allow broadcast messages to be fragmented */ if (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 (ia != NULL) { ia4_release(ia, &psref_ia); ia = NULL; } /* * 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, inp, flags, &mtu, &natt_frag, &ipsec_done); if (error || ipsec_done) goto done; } if (!ipsec_used || !natt_frag) #endif { /* * Run through list of hooks for output packets. */ error = pfil_run_hooks(inet_pfil_hook, &m, ifp, PFIL_OUT); if (error || m == NULL) { IP_STATINC(IP_STAT_PFILDROP_OUT); goto done; } } ip = mtod(m, struct ip *); hlen = ip->ip_hl << 2; m->m_pkthdr.csum_data |= hlen << 16; /* * search for the source address structure to * maintain output statistics, and verify address * validity */ KASSERT(ia == NULL); sockaddr_in_init(&usrc.sin, &ip->ip_src, 0); ifa = ifaof_ifpforaddr_psref(&usrc.sa, ifp, &psref_ia); if (ifa != NULL) ia = ifatoia(ifa); /* * Ensure we only send from a valid address. * A NULL address is valid because the packet could be * generated from a packet filter. */ if (ia != NULL && (flags & IP_FORWARDING) == 0 && (error = ip_ifaddrvalid(ia)) != 0) { ARPLOG(LOG_ERR, "refusing to send from invalid address %s (pid %d)\n", ARPLOGADDR(&ip->ip_src), curproc->p_pid); IP_STATINC(IP_STAT_ODROPPED); if (error == 1) /* * Address exists, but is tentative or detached. * We can't send from it because it's invalid, * so we drop the packet. */ error = 0; else error = EADDRNOTAVAIL; goto bad; } /* 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_undefer_cksum_tcpudp(m); } m->m_pkthdr.csum_flags &= ~(M_CSUM_TCPv4|M_CSUM_UDPv4); } } sa = (m->m_flags & M_MCAST) ? sintocsa(rdst) : sintocsa(dst); if (__predict_false(sw_csum & M_CSUM_TSOv4)) { /* * TSO4 is required by a packet, but disabled for * the interface. */ error = ip_tso_output(ifp, m, sa, rt); } else error = ip_if_output(ifp, m, sa, rt); goto done; } /* * We can't use HW checksumming if we're about 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_undefer_cksum_tcpudp(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) { KASSERT(inp != NULL); 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 = NULL; 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, NULL, flags | IP_RAWOUTPUT | IP_NOIPNEWID, imo, inp); } else { KASSERT((m->m_pkthdr.csum_flags & (M_CSUM_UDPv4 | M_CSUM_TCPv4)) == 0); error = ip_if_output(ifp, m, (m->m_flags & M_MCAST) ? sintocsa(rdst) : sintocsa(dst), rt); } } if (error == 0) { IP_STATINC(IP_STAT_FRAGMENTED); } done: ia4_release(ia, &psref_ia); rtcache_unref(rt, ro); if (ro == &iproute) { rtcache_free(&iproute); } if (mifp != NULL) { if_put(mifp, &psref); } if (bind_need_restore) curlwp_bindx(bound); 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 error = 0; int ipoff, ipflg; ip = mtod(m, struct ip *); hlen = ip->ip_hl << 2; /* Preserve the offset and flags. */ ipoff = ntohs(ip->ip_off) & IP_OFFMASK; ipflg = ntohs(ip->ip_off) & (IP_RF|IP_DF|IP_MF); 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 == NULL) { 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 the flags */ m->m_flags |= m0->m_flags & M_COPYFLAGS; 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) + ipoff; mhip->ip_off |= ipflg; 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 == NULL) { error = ENOBUFS; IP_STATINC(IP_STAT_ODROPPED); goto sendorfree; } m->m_pkthdr.len = mhlen + len; m_reset_rcvif(m); 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) { IFQ_LOCK(&ifp->if_snd); 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); } IFQ_UNLOCK(&ifp->if_snd); } if (error) { for (m = m0; m; m = m0) { m0 = m->m_nextpkt; m->m_nextpkt = NULL; m_freem(m); } } return error; } /* * 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); KASSERT(optlen % 4 == 0); 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 == NULL) 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; n->m_len = optlen + sizeof(struct ip); n->m_data += max_linkhdr; memcpy(mtod(n, void *), ip, sizeof(struct ip)); m = n; } 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 *); memcpy(ip + 1, p->ipopt_list, optlen); *phlen = sizeof(struct ip) + optlen; ip->ip_len = htons(ntohs(ip->ip_len) + optlen); return m; } /* * Copy options from ipsrc to ipdst, omitting those not copied during * fragmentation. */ int ip_optcopy(struct ip *ipsrc, struct ip *ipdst) { u_char *cp, *dp; int opt, optlen, cnt; cp = (u_char *)(ipsrc + 1); dp = (u_char *)(ipdst + 1); cnt = (ipsrc->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 *)(ipdst+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; struct in_pktinfo pktinfo; KASSERT(solocked(so)); 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_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_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; case IP_PKTINFO: error = sockopt_getint(sopt, &optval); if (!error) { /* Linux compatibility */ OPTSET(INP_RECVPKTINFO); break; } error = sockopt_get(sopt, &pktinfo, sizeof(pktinfo)); if (error) break; if (pktinfo.ipi_ifindex == 0) { inp->inp_prefsrcip = pktinfo.ipi_addr; break; } /* Solaris compatibility */ struct ifnet *ifp; struct in_ifaddr *ia; int s; /* pick up primary address */ s = pserialize_read_enter(); ifp = if_byindex(pktinfo.ipi_ifindex); if (ifp == NULL) { pserialize_read_exit(s); error = EADDRNOTAVAIL; break; } ia = in_get_ia_from_ifp(ifp); if (ia == NULL) { pserialize_read_exit(s); error = EADDRNOTAVAIL; break; } inp->inp_prefsrcip = IA_SIN(ia)->sin_addr; pserialize_read_exit(s); 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->inp_moptions, 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 = ipsec_set_policy(inp, sopt->sopt_data, sopt->sopt_size, curlwp->l_cred); } else error = ENOPROTOOPT; break; #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_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_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; case IP_PKTINFO: switch (sopt->sopt_size) { case sizeof(int): /* Linux compatibility */ optval = OPTBIT(INP_RECVPKTINFO); error = sockopt_setint(sopt, optval); break; case sizeof(struct in_pktinfo): /* Solaris compatibility */ pktinfo.ipi_ifindex = 0; pktinfo.ipi_addr = inp->inp_prefsrcip; error = sockopt_set(sopt, &pktinfo, sizeof(pktinfo)); break; default: /* * While size is stuck at 0, and, later, if * the caller doesn't use an exactly sized * recipient for the data, default to Linux * compatibility */ optval = OPTBIT(INP_RECVPKTINFO); error = sockopt_setint(sopt, optval); break; } break; #if 0 /* defined(IPSEC) */ case IP_IPSEC_POLICY: { struct mbuf *m = NULL; /* XXX this will return EINVAL as sopt is empty */ error = ipsec_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->inp_moptions, 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; } static int ip_pktinfo_prepare(const struct in_pktinfo *pktinfo, struct ip_pktopts *pktopts, int *flags, kauth_cred_t cred) { struct ip_moptions *imo; int error = 0; bool addrset = false; if (!in_nullhost(pktinfo->ipi_addr)) { pktopts->ippo_laddr.sin_addr = pktinfo->ipi_addr; /* EADDRNOTAVAIL? */ error = in_pcbbindableaddr(&pktopts->ippo_laddr, cred); if (error != 0) return error; addrset = true; } if (pktinfo->ipi_ifindex != 0) { if (!addrset) { struct ifnet *ifp; struct in_ifaddr *ia; int s; /* pick up primary address */ s = pserialize_read_enter(); ifp = if_byindex(pktinfo->ipi_ifindex); if (ifp == NULL) { pserialize_read_exit(s); return EADDRNOTAVAIL; } ia = in_get_ia_from_ifp(ifp); if (ia == NULL) { pserialize_read_exit(s); return EADDRNOTAVAIL; } pktopts->ippo_laddr.sin_addr = IA_SIN(ia)->sin_addr; pserialize_read_exit(s); } /* * If specified ipi_ifindex, * use copied or locally initialized ip_moptions. * Original ip_moptions must not be modified. */ imo = &pktopts->ippo_imobuf; /* local buf in pktopts */ if (pktopts->ippo_imo != NULL) { memcpy(imo, pktopts->ippo_imo, sizeof(*imo)); } else { memset(imo, 0, sizeof(*imo)); imo->imo_multicast_ttl = IP_DEFAULT_MULTICAST_TTL; imo->imo_multicast_loop = IP_DEFAULT_MULTICAST_LOOP; } imo->imo_multicast_if_index = pktinfo->ipi_ifindex; pktopts->ippo_imo = imo; *flags |= IP_ROUTETOIFINDEX; } return error; } /* * Set up IP outgoing packet options. Even if control is NULL, * pktopts->ippo_laddr and pktopts->ippo_imo are set and used. */ int ip_setpktopts(struct mbuf *control, struct ip_pktopts *pktopts, int *flags, struct inpcb *inp, kauth_cred_t cred) { struct cmsghdr *cm; struct in_pktinfo pktinfo; int error; pktopts->ippo_imo = inp->inp_moptions; struct in_addr *ia = in_nullhost(inp->inp_prefsrcip) ? &inp->inp_laddr : &inp->inp_prefsrcip; sockaddr_in_init(&pktopts->ippo_laddr, ia, 0); if (control == NULL) return 0; /* * XXX: Currently, we assume all the optional information is * stored in a single mbuf. */ if (control->m_next) return EINVAL; for (; control->m_len > 0; control->m_data += CMSG_ALIGN(cm->cmsg_len), control->m_len -= CMSG_ALIGN(cm->cmsg_len)) { cm = mtod(control, struct cmsghdr *); if ((control->m_len < sizeof(*cm)) || (cm->cmsg_len == 0) || (cm->cmsg_len > control->m_len)) { return EINVAL; } if (cm->cmsg_level != IPPROTO_IP) continue; switch (cm->cmsg_type) { case IP_PKTINFO: if (cm->cmsg_len != CMSG_LEN(sizeof(pktinfo))) return EINVAL; memcpy(&pktinfo, CMSG_DATA(cm), sizeof(pktinfo)); error = ip_pktinfo_prepare(&pktinfo, pktopts, flags, cred); if (error) return error; break; case IP_SENDSRCADDR: /* FreeBSD compatibility */ if (cm->cmsg_len != CMSG_LEN(sizeof(struct in_addr))) return EINVAL; pktinfo.ipi_ifindex = 0; pktinfo.ipi_addr = ((struct in_pktinfo *)CMSG_DATA(cm))->ipi_addr; error = ip_pktinfo_prepare(&pktinfo, pktopts, flags, cred); if (error) return error; break; default: return ENOPROTOOPT; } } return 0; } /* * 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; KASSERT(inp_locked(inp)); /* 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; if (cnt % 4) { /* Must be 4-byte aligned, because there's no padding. */ return EINVAL; } 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. * Must be called in a pserialize critical section. */ 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 { IN_ADDRHASH_READER_FOREACH(ia, a->s_addr) { if (in_hosteq(ia->ia_addr.sin_addr, *a) && (ia->ia_ifp->if_flags & IFF_MULTICAST) != 0) { ifp = ia->ia_ifp; if (if_is_deactivated(ifp)) ifp = NULL; 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; } static int ip_get_membership(const struct sockopt *sopt, struct ifnet **ifp, struct psref *psref, struct in_addr *ia, bool add) { int error; struct ip_mreq mreq; error = sockopt_get(sopt, &mreq, sizeof(mreq)); if (error) return error; if (!IN_MULTICAST(mreq.imr_multiaddr.s_addr)) return EINVAL; memcpy(ia, &mreq.imr_multiaddr, sizeof(*ia)); if (in_nullhost(mreq.imr_interface)) { union { struct sockaddr dst; struct sockaddr_in dst4; } u; struct route ro; if (!add) { *ifp = NULL; return 0; } /* * If no interface address was provided, use the interface of * the route to the given multicast address. */ struct rtentry *rt; memset(&ro, 0, sizeof(ro)); sockaddr_in_init(&u.dst4, ia, 0); error = rtcache_setdst(&ro, &u.dst); if (error != 0) return error; *ifp = (rt = rtcache_init(&ro)) != NULL ? rt->rt_ifp : NULL; if (*ifp != NULL) { if (if_is_deactivated(*ifp)) *ifp = NULL; else if_acquire(*ifp, psref); } rtcache_unref(rt, &ro); rtcache_free(&ro); } else { int s = pserialize_read_enter(); *ifp = ip_multicast_if(&mreq.imr_interface, NULL); if (!add && *ifp == NULL) { pserialize_read_exit(s); return EADDRNOTAVAIL; } if (*ifp != NULL) { if (if_is_deactivated(*ifp)) *ifp = NULL; else if_acquire(*ifp, psref); } pserialize_read_exit(s); } return 0; } /* * Add a multicast group membership. * Group must be a valid IP multicast address. */ static int ip_add_membership(struct ip_moptions *imo, const struct sockopt *sopt) { struct ifnet *ifp = NULL; // XXX: gcc [ppc] struct in_addr ia; int i, error, bound; struct psref psref; /* imo is protected by solock or referenced only by the caller */ bound = curlwp_bind(); if (sopt->sopt_size == sizeof(struct ip_mreq)) error = ip_get_membership(sopt, &ifp, &psref, &ia, true); else { #ifdef INET6 error = ip6_get_membership(sopt, &ifp, &psref, &ia, sizeof(ia)); #else error = EINVAL; #endif } if (error) goto out; /* * See if we found an interface, and confirm that it * supports multicast. */ if (ifp == NULL || (ifp->if_flags & IFF_MULTICAST) == 0) { error = EADDRNOTAVAIL; goto out; } /* * 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, ia)) break; } if (i < imo->imo_num_memberships) { error = EADDRINUSE; goto out; } if (i == IP_MAX_MEMBERSHIPS) { error = ETOOMANYREFS; goto out; } /* * Everything looks good; add a new record to the multicast * address list for the given interface. */ imo->imo_membership[i] = in_addmulti(&ia, ifp); if (imo->imo_membership[i] == NULL) { error = ENOBUFS; goto out; } ++imo->imo_num_memberships; error = 0; out: if_put(ifp, &psref); curlwp_bindx(bound); return error; } /* * Drop a multicast group membership. * Group must be a valid IP multicast address. */ static int ip_drop_membership(struct ip_moptions *imo, const struct sockopt *sopt) { struct in_addr ia = { .s_addr = 0 }; // XXX: gcc [ppc] struct ifnet *ifp = NULL; // XXX: gcc [ppc] int i, error, bound; struct psref psref; /* imo is protected by solock or referenced only by the caller */ bound = curlwp_bind(); if (sopt->sopt_size == sizeof(struct ip_mreq)) error = ip_get_membership(sopt, &ifp, &psref, &ia, false); else { #ifdef INET6 error = ip6_get_membership(sopt, &ifp, &psref, &ia, sizeof(ia)); #else error = EINVAL; #endif } if (error) goto out; /* * 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, ia)) break; } if (i == imo->imo_num_memberships) { error = EADDRNOTAVAIL; goto out; } /* * 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; error = 0; out: if_put(ifp, &psref); curlwp_bindx(bound); return error; } /* * Set the IP multicast options in response to user setsockopt(). */ int ip_setmoptions(struct ip_moptions **pimo, const struct sockopt *sopt) { struct ip_moptions *imo = *pimo; struct in_addr addr; struct ifnet *ifp; int ifindex, error = 0; /* The passed imo isn't NULL, it should be protected by solock */ 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_if_index = 0; 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; *pimo = imo; } switch (sopt->sopt_name) { case IP_MULTICAST_IF: { int s; /* * 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_if_index = 0; break; } /* * The selected interface is identified by its local * IP address. Find the interface and confirm that * it supports multicasting. */ s = pserialize_read_enter(); ifp = ip_multicast_if(&addr, &ifindex); if (ifp == NULL || (ifp->if_flags & IFF_MULTICAST) == 0) { pserialize_read_exit(s); error = EADDRNOTAVAIL; break; } imo->imo_multicast_if_index = ifp->if_index; pserialize_read_exit(s); 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: /* IPV6_JOIN_GROUP */ error = ip_add_membership(imo, sopt); break; case IP_DROP_MEMBERSHIP: /* IPV6_LEAVE_GROUP */ error = ip_drop_membership(imo, sopt); break; default: error = EOPNOTSUPP; break; } /* * If all options have default values, no need to keep the mbuf. */ if (imo->imo_multicast_if_index == 0 && imo->imo_multicast_ttl == IP_DEFAULT_MULTICAST_TTL && imo->imo_multicast_loop == IP_DEFAULT_MULTICAST_LOOP && imo->imo_num_memberships == 0) { kmem_intr_free(imo, sizeof(*imo)); *pimo = NULL; } return error; } /* * Return the IP multicast options in response to user getsockopt(). */ int ip_getmoptions(struct ip_moptions *imo, struct sockopt *sopt) { struct in_addr addr; uint8_t optval; int error = 0; /* imo is protected by solock or refereced only by the caller */ switch (sopt->sopt_name) { case IP_MULTICAST_IF: if (imo == NULL || imo->imo_multicast_if_index == 0) addr = zeroin_addr; else if (imo->imo_multicast_addr.s_addr) { /* return the value user has set */ addr = imo->imo_multicast_addr; } else { struct ifnet *ifp; struct in_ifaddr *ia = NULL; int s = pserialize_read_enter(); ifp = if_byindex(imo->imo_multicast_if_index); if (ifp != NULL) { ia = in_get_ia_from_ifp(ifp); } addr = ia ? ia->ia_addr.sin_addr : zeroin_addr; pserialize_read_exit(s); } 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; /* The owner of imo (inp) should be protected by solock */ if (imo != NULL) { for (i = 0; i < imo->imo_num_memberships; ++i) { struct in_multi *inm = imo->imo_membership[i]; in_delmulti(inm); /* ifp should not leave thanks to solock */ } kmem_intr_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_undefer_cksum_tcpudp(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_UNLESS_NET_MPSAFE(); (void)looutput(ifp, copym, sintocsa(dst), NULL); KERNEL_UNLOCK_UNLESS_NET_MPSAFE(); } /* * Ensure sending address is valid. * Returns 0 on success, -1 if an error should be sent back or 1 * if the packet could be dropped without error (protocol dependent). */ static int ip_ifaddrvalid(const struct in_ifaddr *ia) { if (ia->ia_addr.sin_addr.s_addr == INADDR_ANY) return 0; if (ia->ia4_flags & IN_IFF_DUPLICATED) return -1; else if (ia->ia4_flags & (IN_IFF_TENTATIVE | IN_IFF_DETACHED)) return 1; return 0; }