/* $NetBSD: ip_output.c,v 1.56 1999/01/19 23:39:57 mycroft Exp $ */ /*- * 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. * 3. All advertising materials mentioning features or use of this software * must display the following acknowledgement: * This product includes software developed by the NetBSD * Foundation, Inc. and its contributors. * 4. Neither the name of The NetBSD Foundation 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 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. All advertising materials mentioning features or use of this software * must display the following acknowledgement: * This product includes software developed by the University of * California, Berkeley and its contributors. * 4. Neither the name of the University nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * * @(#)ip_output.c 8.3 (Berkeley) 1/21/94 */ #include "opt_pfil_hooks.h" #include "opt_mrouting.h" #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #ifdef __vax__ #include #endif #include static struct mbuf *ip_insertoptions __P((struct mbuf *, struct mbuf *, int *)); static void ip_mloopback __P((struct ifnet *, struct mbuf *, struct sockaddr_in *)); /* * 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 #if __STDC__ ip_output(struct mbuf *m0, ...) #else ip_output(m0, va_alist) struct mbuf *m0; va_dcl #endif { register struct ip *ip, *mhip; register struct ifnet *ifp; register struct mbuf *m = m0; register int hlen = sizeof (struct ip); int len, off, error = 0; struct route iproute; struct sockaddr_in *dst; struct in_ifaddr *ia; struct mbuf *opt; struct route *ro; int flags; int *mtu_p; int mtu; struct ip_moptions *imo; va_list ap; #ifdef PFIL_HOOKS struct packet_filter_hook *pfh; struct mbuf *m1; int rv; #endif /* PFIL_HOOKS */ 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 *); if (flags & IP_RETURNMTU) mtu_p = va_arg(ap, int *); else mtu_p = NULL; va_end(ap); #ifdef DIAGNOSTIC if ((m->m_flags & M_PKTHDR) == 0) panic("ip_output no HDR"); #endif 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 &= IP_DF; ip->ip_id = htons(ip_id++); ip->ip_hl = hlen >> 2; ipstat.ips_localout++; } else { hlen = ip->ip_hl << 2; } /* * Route packet. */ if (ro == 0) { ro = &iproute; bzero((caddr_t)ro, sizeof (*ro)); } dst = satosin(&ro->ro_dst); /* * If there is a cached route, * check that it is to the same destination * and is still up. If not, free it and try again. */ if (ro->ro_rt && ((ro->ro_rt->rt_flags & RTF_UP) == 0 || !in_hosteq(dst->sin_addr, ip->ip_dst))) { RTFREE(ro->ro_rt); ro->ro_rt = (struct rtentry *)0; } if (ro->ro_rt == 0) { dst->sin_family = AF_INET; dst->sin_len = sizeof(*dst); dst->sin_addr = ip->ip_dst; } /* * If routing to interface only, * short circuit routing lookup. */ if (flags & IP_ROUTETOIF) { if ((ia = ifatoia(ifa_ifwithladdr(sintosa(dst)))) == 0) { ipstat.ips_noroute++; error = ENETUNREACH; goto bad; } ifp = ia->ia_ifp; mtu = ifp->if_mtu; ip->ip_ttl = 1; } else { if (ro->ro_rt == 0) rtalloc(ro); if (ro->ro_rt == 0) { ipstat.ips_noroute++; error = EHOSTUNREACH; goto bad; } ia = ifatoia(ro->ro_rt->rt_ifa); ifp = ro->ro_rt->rt_ifp; if ((mtu = ro->ro_rt->rt_rmx.rmx_mtu) == 0) mtu = ifp->if_mtu; ro->ro_rt->rt_use++; if (ro->ro_rt->rt_flags & RTF_GATEWAY) dst = satosin(ro->ro_rt->rt_gateway); } if (IN_MULTICAST(ip->ip_dst.s_addr)) { struct in_multi *inm; m->m_flags |= M_MCAST; /* * IP destination address is multicast. Make sure "dst" * still points to the address in "ro". (It may have been * changed to point to a gateway address, above.) */ dst = satosin(&ro->ro_dst); /* * See if the caller provided any multicast options */ if (imo != NULL) { ip->ip_ttl = imo->imo_multicast_ttl; if (imo->imo_multicast_ifp != NULL) { ifp = imo->imo_multicast_ifp; mtu = ifp->if_mtu; } } else ip->ip_ttl = IP_DEFAULT_MULTICAST_TTL; /* * Confirm that the outgoing interface supports multicast. */ if ((ifp->if_flags & IFF_MULTICAST) == 0) { ipstat.ips_noroute++; error = ENETUNREACH; goto bad; } /* * If source address not specified yet, use an address * of outgoing interface. */ if (in_nullhost(ip->ip_src)) { register struct in_ifaddr *ia; IFP_TO_IA(ifp, ia); ip->ip_src = ia->ia_addr.sin_addr; } IN_LOOKUP_MULTI(ip->ip_dst, ifp, inm); if (inm != NULL && (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, dst); } #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; } #ifndef notdef /* * If source address not specified yet, use address * of outgoing interface. */ if (in_nullhost(ip->ip_src)) ip->ip_src = ia->ia_addr.sin_addr; #endif /* * 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 ((u_int16_t)ip->ip_len > ifp->if_mtu) { error = EMSGSIZE; goto bad; } m->m_flags |= M_BCAST; } else m->m_flags &= ~M_BCAST; #ifdef PFIL_HOOKS /* * Run through list of hooks for output packets. */ m1 = m; for (pfh = pfil_hook_get(PFIL_OUT); pfh; pfh = pfh->pfil_link.tqe_next) if (pfh->pfil_func) { rv = pfh->pfil_func(ip, hlen, ifp, 1, &m1); if (rv) { error = EHOSTUNREACH; goto done; } m = m1; if (m == NULL) goto done; ip = mtod(m, struct ip *); } #endif /* PFIL_HOOKS */ sendit: /* * If small enough for mtu of path, can just send directly. */ if ((u_int16_t)ip->ip_len <= mtu) { HTONS(ip->ip_len); HTONS(ip->ip_off); ip->ip_sum = 0; ip->ip_sum = in_cksum(m, hlen); error = (*ifp->if_output)(ifp, m, sintosa(dst), ro->ro_rt); goto done; } /* * Too large for interface; fragment if possible. * Must be able to put at least 8 bytes per fragment. */ if (ip->ip_off & IP_DF) { if (flags & IP_RETURNMTU) *mtu_p = mtu; error = EMSGSIZE; ipstat.ips_cantfrag++; goto bad; } len = (mtu - hlen) &~ 7; if (len < 8) { error = EMSGSIZE; goto bad; } { int mhlen, firstlen = len; struct mbuf **mnext = &m->m_nextpkt; int fragments = 0; int s; /* * Loop through length of segment after first fragment, * make new header and copy data of each part and link onto chain. */ m0 = m; mhlen = sizeof (struct ip); for (off = hlen + len; off < (u_int16_t)ip->ip_len; off += len) { MGETHDR(m, M_DONTWAIT, MT_HEADER); if (m == 0) { error = ENOBUFS; ipstat.ips_odropped++; goto sendorfree; } *mnext = m; mnext = &m->m_nextpkt; m->m_data += max_linkhdr; mhip = mtod(m, struct ip *); *mhip = *ip; if (hlen > sizeof (struct ip)) { mhlen = ip_optcopy(ip, mhip) + sizeof (struct ip); mhip->ip_hl = mhlen >> 2; } m->m_len = mhlen; mhip->ip_off = ((off - hlen) >> 3) + (ip->ip_off & ~IP_MF); if (ip->ip_off & IP_MF) mhip->ip_off |= IP_MF; if (off + len >= (u_int16_t)ip->ip_len) len = (u_int16_t)ip->ip_len - off; else mhip->ip_off |= IP_MF; mhip->ip_len = htons((u_int16_t)(len + mhlen)); m->m_next = m_copy(m0, off, len); if (m->m_next == 0) { error = ENOBUFS; /* ??? */ ipstat.ips_odropped++; goto sendorfree; } m->m_pkthdr.len = mhlen + len; m->m_pkthdr.rcvif = (struct ifnet *)0; HTONS(mhip->ip_off); mhip->ip_sum = 0; mhip->ip_sum = in_cksum(m, mhlen); ipstat.ips_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 - (u_int16_t)ip->ip_len); m->m_pkthdr.len = hlen + firstlen; ip->ip_len = htons((u_int16_t)m->m_pkthdr.len); ip->ip_off |= IP_MF; HTONS(ip->ip_off); ip->ip_sum = 0; ip->ip_sum = in_cksum(m, hlen); sendorfree: /* * If there is no room for all the fragments, don't queue * any of them. */ s = splimp(); if (ifp->if_snd.ifq_maxlen - ifp->if_snd.ifq_len < fragments) error = ENOBUFS; splx(s); for (m = m0; m; m = m0) { m0 = m->m_nextpkt; m->m_nextpkt = 0; if (error == 0) error = (*ifp->if_output)(ifp, m, sintosa(dst), ro->ro_rt); else m_freem(m); } if (error == 0) ipstat.ips_fragmented++; } done: if (ro == &iproute && (flags & IP_ROUTETOIF) == 0 && ro->ro_rt) { RTFREE(ro->ro_rt); ro->ro_rt = 0; } return (error); bad: m_freem(m); goto done; } /* * 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(inp) 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)); else 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(m, opt, phlen) register struct mbuf *m; struct mbuf *opt; int *phlen; { register struct ipoption *p = mtod(opt, struct ipoption *); struct mbuf *n; register struct ip *ip = mtod(m, struct ip *); unsigned optlen; optlen = opt->m_len - sizeof(p->ipopt_dst); if (optlen + (u_int16_t)ip->ip_len > IP_MAXPACKET) return (m); /* XXX should fail */ if (!in_nullhost(p->ipopt_dst)) ip->ip_dst = p->ipopt_dst; if (m->m_flags & M_EXT || m->m_data - optlen < m->m_pktdat) { MGETHDR(n, M_DONTWAIT, MT_HEADER); if (n == 0) return (m); n->m_pkthdr.len = m->m_pkthdr.len + optlen; m->m_len -= sizeof(struct ip); m->m_data += sizeof(struct ip); n->m_next = m; m = n; m->m_len = optlen + sizeof(struct ip); m->m_data += max_linkhdr; bcopy((caddr_t)ip, mtod(m, caddr_t), sizeof(struct ip)); } else { m->m_data -= optlen; m->m_len += optlen; m->m_pkthdr.len += optlen; ovbcopy((caddr_t)ip, mtod(m, caddr_t), sizeof(struct ip)); } ip = mtod(m, struct ip *); bcopy((caddr_t)p->ipopt_list, (caddr_t)(ip + 1), (unsigned)optlen); *phlen = sizeof(struct ip) + optlen; ip->ip_len += optlen; return (m); } /* * Copy options from ip to jp, * omitting those not copied during fragmentation. */ int ip_optcopy(ip, jp) struct ip *ip, *jp; { register u_char *cp, *dp; int opt, optlen, cnt; cp = (u_char *)(ip + 1); dp = (u_char *)(jp + 1); cnt = (ip->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; } else optlen = cp[IPOPT_OLEN]; /* bogus lengths should have been caught by ip_dooptions */ if (optlen > cnt) optlen = cnt; if (IPOPT_COPIED(opt)) { bcopy((caddr_t)cp, (caddr_t)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(op, so, level, optname, mp) int op; struct socket *so; int level, optname; struct mbuf **mp; { register struct inpcb *inp = sotoinpcb(so); register struct mbuf *m = *mp; register int optval = 0; int error = 0; if (level != IPPROTO_IP) { error = EINVAL; if (op == PRCO_SETOPT && *mp) (void) m_free(*mp); } else switch (op) { case PRCO_SETOPT: switch (optname) { case IP_OPTIONS: #ifdef notyet case IP_RETOPTS: return (ip_pcbopts(optname, &inp->inp_options, m)); #else return (ip_pcbopts(&inp->inp_options, m)); #endif case IP_TOS: case IP_TTL: case IP_RECVOPTS: case IP_RECVRETOPTS: case IP_RECVDSTADDR: case IP_RECVIF: if (m == NULL || m->m_len != sizeof(int)) error = EINVAL; else { optval = *mtod(m, int *); switch (optname) { case IP_TOS: inp->inp_ip.ip_tos = optval; break; case IP_TTL: inp->inp_ip.ip_ttl = optval; break; #define OPTSET(bit) \ if (optval) \ inp->inp_flags |= bit; \ else \ inp->inp_flags &= ~bit; case IP_RECVOPTS: OPTSET(INP_RECVOPTS); break; case IP_RECVRETOPTS: OPTSET(INP_RECVRETOPTS); break; case IP_RECVDSTADDR: OPTSET(INP_RECVDSTADDR); break; case IP_RECVIF: OPTSET(INP_RECVIF); break; } } 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(optname, &inp->inp_moptions, m); break; case IP_PORTRANGE: if (m == 0 || m->m_len != sizeof(int)) error = EINVAL; else { optval = *mtod(m, int *); switch (optval) { case IP_PORTRANGE_DEFAULT: case IP_PORTRANGE_HIGH: inp->inp_flags &= ~(INP_LOWPORT); break; case IP_PORTRANGE_LOW: inp->inp_flags |= INP_LOWPORT; break; default: error = EINVAL; break; } } break; default: error = ENOPROTOOPT; break; } if (m) (void)m_free(m); break; case PRCO_GETOPT: switch (optname) { case IP_OPTIONS: case IP_RETOPTS: *mp = m = m_get(M_WAIT, MT_SOOPTS); if (inp->inp_options) { m->m_len = inp->inp_options->m_len; bcopy(mtod(inp->inp_options, caddr_t), mtod(m, caddr_t), (unsigned)m->m_len); } else m->m_len = 0; break; case IP_TOS: case IP_TTL: case IP_RECVOPTS: case IP_RECVRETOPTS: case IP_RECVDSTADDR: case IP_RECVIF: case IP_ERRORMTU: *mp = m = m_get(M_WAIT, MT_SOOPTS); m->m_len = sizeof(int); switch (optname) { case IP_TOS: optval = inp->inp_ip.ip_tos; break; case IP_TTL: optval = inp->inp_ip.ip_ttl; break; case IP_ERRORMTU: optval = inp->inp_errormtu; break; #define OPTBIT(bit) (inp->inp_flags & bit ? 1 : 0) case IP_RECVOPTS: optval = OPTBIT(INP_RECVOPTS); break; case IP_RECVRETOPTS: optval = OPTBIT(INP_RECVRETOPTS); break; case IP_RECVDSTADDR: optval = OPTBIT(INP_RECVDSTADDR); break; case IP_RECVIF: optval = OPTBIT(INP_RECVIF); break; } *mtod(m, int *) = optval; break; case IP_MULTICAST_IF: case IP_MULTICAST_TTL: case IP_MULTICAST_LOOP: case IP_ADD_MEMBERSHIP: case IP_DROP_MEMBERSHIP: error = ip_getmoptions(optname, inp->inp_moptions, mp); break; case IP_PORTRANGE: *mp = m = m_get(M_WAIT, MT_SOOPTS); m->m_len = sizeof(int); if (inp->inp_flags & INP_LOWPORT) optval = IP_PORTRANGE_LOW; else optval = IP_PORTRANGE_DEFAULT; *mtod(m, int *) = optval; break; default: error = ENOPROTOOPT; break; } break; } return (error); } /* * Set up IP options in pcb for insertion in output packets. * Store in mbuf with pointer in pcbopt, adding pseudo-option * with destination address if source routed. */ int #ifdef notyet ip_pcbopts(optname, pcbopt, m) int optname; #else ip_pcbopts(pcbopt, m) #endif struct mbuf **pcbopt; register struct mbuf *m; { register int cnt, optlen; register u_char *cp; u_char opt; /* turn off any old options */ if (*pcbopt) (void)m_free(*pcbopt); *pcbopt = 0; if (m == (struct mbuf *)0 || m->m_len == 0) { /* * Only turning off any previous options. */ if (m) (void)m_free(m); return (0); } #ifndef vax if (m->m_len % sizeof(int32_t)) goto bad; #endif /* * IP first-hop destination address will be stored before * actual options; move other options back * and clear it when none present. */ if (m->m_data + m->m_len + sizeof(struct in_addr) >= &m->m_dat[MLEN]) goto bad; cnt = m->m_len; m->m_len += sizeof(struct in_addr); cp = mtod(m, u_char *) + sizeof(struct in_addr); ovbcopy(mtod(m, caddr_t), (caddr_t)cp, (unsigned)cnt); bzero(mtod(m, caddr_t), sizeof(struct in_addr)); for (; cnt > 0; cnt -= optlen, cp += optlen) { opt = cp[IPOPT_OPTVAL]; if (opt == IPOPT_EOL) break; if (opt == IPOPT_NOP) optlen = 1; else { optlen = cp[IPOPT_OLEN]; if (optlen <= IPOPT_OLEN || optlen > cnt) goto bad; } switch (opt) { default: break; case IPOPT_LSRR: case IPOPT_SSRR: /* * user process specifies route as: * ->A->B->C->D * D must be our final destination (but we can't * check that since we may not have connected yet). * A is first hop destination, which doesn't appear in * actual IP option, but is stored before the options. */ if (optlen < IPOPT_MINOFF - 1 + sizeof(struct in_addr)) goto bad; m->m_len -= sizeof(struct in_addr); cnt -= sizeof(struct in_addr); optlen -= sizeof(struct in_addr); cp[IPOPT_OLEN] = optlen; /* * Move first hop before start of options. */ bcopy((caddr_t)&cp[IPOPT_OFFSET+1], mtod(m, caddr_t), sizeof(struct in_addr)); /* * Then copy rest of options back * to close up the deleted entry. */ ovbcopy((caddr_t)(&cp[IPOPT_OFFSET+1] + sizeof(struct in_addr)), (caddr_t)&cp[IPOPT_OFFSET+1], (unsigned)cnt + sizeof(struct in_addr)); break; } } if (m->m_len > MAX_IPOPTLEN + sizeof(struct in_addr)) goto bad; *pcbopt = m; return (0); bad: (void)m_free(m); return (EINVAL); } /* * Set the IP multicast options in response to user setsockopt(). */ int ip_setmoptions(optname, imop, m) int optname; struct ip_moptions **imop; struct mbuf *m; { register int error = 0; u_char loop; register int i; struct in_addr addr; register struct ip_mreq *mreq; register struct ifnet *ifp; register struct ip_moptions *imo = *imop; struct route ro; register struct sockaddr_in *dst; if (imo == NULL) { /* * No multicast option buffer attached to the pcb; * allocate one and initialize to default values. */ imo = (struct ip_moptions *)malloc(sizeof(*imo), M_IPMOPTS, M_WAITOK); if (imo == NULL) return (ENOBUFS); *imop = imo; 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; } switch (optname) { case IP_MULTICAST_IF: /* * Select the interface for outgoing multicast packets. */ if (m == NULL || m->m_len != sizeof(struct in_addr)) { error = EINVAL; break; } addr = *(mtod(m, struct in_addr *)); /* * 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. */ INADDR_TO_IFP(addr, ifp); if (ifp == NULL || (ifp->if_flags & IFF_MULTICAST) == 0) { error = EADDRNOTAVAIL; break; } imo->imo_multicast_ifp = ifp; break; case IP_MULTICAST_TTL: /* * Set the IP time-to-live for outgoing multicast packets. */ if (m == NULL || m->m_len != 1) { error = EINVAL; break; } imo->imo_multicast_ttl = *(mtod(m, u_char *)); break; case IP_MULTICAST_LOOP: /* * Set the loopback flag for outgoing multicast packets. * Must be zero or one. */ if (m == NULL || m->m_len != 1 || (loop = *(mtod(m, u_char *))) > 1) { error = EINVAL; break; } imo->imo_multicast_loop = loop; break; case IP_ADD_MEMBERSHIP: /* * Add a multicast group membership. * Group must be a valid IP multicast address. */ if (m == NULL || m->m_len != sizeof(struct ip_mreq)) { error = EINVAL; break; } mreq = mtod(m, struct ip_mreq *); 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)) { bzero((caddr_t)&ro, sizeof(ro)); ro.ro_rt = NULL; dst = satosin(&ro.ro_dst); dst->sin_len = sizeof(*dst); dst->sin_family = AF_INET; dst->sin_addr = mreq->imr_multiaddr; rtalloc(&ro); if (ro.ro_rt == NULL) { error = EADDRNOTAVAIL; break; } ifp = ro.ro_rt->rt_ifp; rtfree(ro.ro_rt); } else { INADDR_TO_IFP(mreq->imr_interface, ifp); } /* * 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. */ if (m == NULL || m->m_len != sizeof(struct ip_mreq)) { error = EINVAL; break; } mreq = mtod(m, struct ip_mreq *); 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 { INADDR_TO_IFP(mreq->imr_interface, ifp); 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) { free(*imop, M_IPMOPTS); *imop = NULL; } return (error); } /* * Return the IP multicast options in response to user getsockopt(). */ int ip_getmoptions(optname, imo, mp) int optname; register struct ip_moptions *imo; register struct mbuf **mp; { u_char *ttl; u_char *loop; struct in_addr *addr; struct in_ifaddr *ia; *mp = m_get(M_WAIT, MT_SOOPTS); switch (optname) { case IP_MULTICAST_IF: addr = mtod(*mp, struct in_addr *); (*mp)->m_len = sizeof(struct in_addr); if (imo == NULL || imo->imo_multicast_ifp == NULL) *addr = zeroin_addr; else { IFP_TO_IA(imo->imo_multicast_ifp, ia); *addr = ia ? ia->ia_addr.sin_addr : zeroin_addr; } return (0); case IP_MULTICAST_TTL: ttl = mtod(*mp, u_char *); (*mp)->m_len = 1; *ttl = imo ? imo->imo_multicast_ttl : IP_DEFAULT_MULTICAST_TTL; return (0); case IP_MULTICAST_LOOP: loop = mtod(*mp, u_char *); (*mp)->m_len = 1; *loop = imo ? imo->imo_multicast_loop : IP_DEFAULT_MULTICAST_LOOP; return (0); default: return (EOPNOTSUPP); } } /* * Discard the IP multicast options. */ void ip_freemoptions(imo) register struct ip_moptions *imo; { register int i; if (imo != NULL) { for (i = 0; i < imo->imo_num_memberships; ++i) in_delmulti(imo->imo_membership[i]); free(imo, M_IPMOPTS); } } /* * 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 &loif -- easier than replicating that code here. */ static void ip_mloopback(ifp, m, dst) struct ifnet *ifp; register struct mbuf *m; register struct sockaddr_in *dst; { register struct ip *ip; struct mbuf *copym; copym = m_copy(m, 0, M_COPYALL); if (copym != NULL) { /* * 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 *); HTONS(ip->ip_len); HTONS(ip->ip_off); ip->ip_sum = 0; ip->ip_sum = in_cksum(copym, ip->ip_hl << 2); (void) looutput(ifp, copym, sintosa(dst), NULL); } }