/* * 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 * $FreeBSD$ */ #define _IP_VHL #include "opt_ipfw.h" #include "opt_ipdn.h" #include "opt_ipdivert.h" #include "opt_ipfilter.h" #include "opt_ipsec.h" #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include "faith.h" #ifdef vax #include #endif #include static MALLOC_DEFINE(M_IPMOPTS, "ip_moptions", "internet multicast options"); #ifdef IPSEC #include #include #ifdef IPSEC_DEBUG #include #else #define KEYDEBUG(lev,arg) #endif #endif /*IPSEC*/ #include #ifdef DUMMYNET #include #endif #ifdef IPFIREWALL_FORWARD_DEBUG #define print_ip(a) printf("%ld.%ld.%ld.%ld",(ntohl(a.s_addr)>>24)&0xFF,\ (ntohl(a.s_addr)>>16)&0xFF,\ (ntohl(a.s_addr)>>8)&0xFF,\ (ntohl(a.s_addr))&0xFF); #endif u_short ip_id; static struct mbuf *ip_insertoptions __P((struct mbuf *, struct mbuf *, int *)); static void ip_mloopback __P((struct ifnet *, struct mbuf *, struct sockaddr_in *, int)); static int ip_getmoptions __P((struct sockopt *, struct ip_moptions *)); static int ip_pcbopts __P((int, struct mbuf **, struct mbuf *)); static int ip_setmoptions __P((struct sockopt *, struct ip_moptions **)); int ip_optcopy __P((struct ip *, struct ip *)); extern int (*fr_checkp) __P((struct ip *, int, struct ifnet *, int, struct mbuf **)); extern struct protosw inetsw[]; /* * 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(m0, opt, ro, flags, imo) struct mbuf *m0; struct mbuf *opt; struct route *ro; int flags; struct ip_moptions *imo; { struct ip *ip, *mhip; struct ifnet *ifp; struct mbuf *m = m0; int hlen = sizeof (struct ip); int len, off, error = 0; struct sockaddr_in *dst; struct in_ifaddr *ia; int isbroadcast; #ifdef IPSEC struct route iproute; struct socket *so = NULL; struct secpolicy *sp = NULL; #endif u_int16_t divert_cookie; /* firewall cookie */ #ifdef IPFIREWALL_FORWARD int fwd_rewrite_src = 0; #endif struct ip_fw_chain *rule = NULL; #ifdef IPDIVERT /* Get and reset firewall cookie */ divert_cookie = ip_divert_cookie; ip_divert_cookie = 0; #else divert_cookie = 0; #endif /* * NOTE: If IP_SOCKINMRCVIF flag is set, 'socket *' is kept in * m->m_pkthdr.rcvif for later IPSEC check. In this case, * m->m_pkthdr will be NULL cleared after the contents is saved in * 'so'. * NULL clearance of rcvif should be natural because the packet should * have been sent from my own socket and has no rcvif in this case. * It is also necessary because someone might consider it as * 'ifnet *', and cause SEGV. */ #if defined(IPFIREWALL) && defined(DUMMYNET) /* * dummynet packet are prepended a vestigial mbuf with * m_type = MT_DUMMYNET and m_data pointing to the matching * rule. */ if (m->m_type == MT_DUMMYNET) { /* * the packet was already tagged, so part of the * processing was already done, and we need to go down. * Get parameters from the header. */ rule = (struct ip_fw_chain *)(m->m_data) ; opt = NULL ; ro = & ( ((struct dn_pkt *)m)->ro ) ; imo = NULL ; dst = ((struct dn_pkt *)m)->dn_dst ; ifp = ((struct dn_pkt *)m)->ifp ; flags = ((struct dn_pkt *)m)->flags ; m0 = m = m->m_next ; #ifdef IPSEC if ((flags & IP_SOCKINMRCVIF) != 0) { so = (struct socket *)m->m_pkthdr.rcvif; m->m_pkthdr.rcvif = NULL; } #endif ip = mtod(m, struct ip *); hlen = IP_VHL_HL(ip->ip_vhl) << 2 ; goto sendit; } else rule = NULL ; #endif #ifdef IPSEC if ((flags & IP_SOCKINMRCVIF) != 0) { so = (struct socket *)m->m_pkthdr.rcvif; m->m_pkthdr.rcvif = NULL; } #endif #ifdef DIAGNOSTIC if ((m->m_flags & M_PKTHDR) == 0) panic("ip_output no HDR"); if (!ro) panic("ip_output no route, proto = %d", mtod(m, struct ip *)->ip_p); #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_vhl = IP_MAKE_VHL(IPVERSION, hlen >> 2); ip->ip_off &= IP_DF; ip->ip_id = htons(ip_id++); ipstat.ips_localout++; } else { hlen = IP_VHL_HL(ip->ip_vhl) << 2; } dst = (struct sockaddr_in *)&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 || dst->sin_addr.s_addr != ip->ip_dst.s_addr)) { 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. */ #define ifatoia(ifa) ((struct in_ifaddr *)(ifa)) #define sintosa(sin) ((struct sockaddr *)(sin)) if (flags & IP_ROUTETOIF) { if ((ia = ifatoia(ifa_ifwithdstaddr(sintosa(dst)))) == 0 && (ia = ifatoia(ifa_ifwithnet(sintosa(dst)))) == 0) { ipstat.ips_noroute++; error = ENETUNREACH; goto bad; } ifp = ia->ia_ifp; ip->ip_ttl = 1; isbroadcast = in_broadcast(dst->sin_addr, ifp); } else { /* * If this is the case, we probably don't want to allocate * a protocol-cloned route since we didn't get one from the * ULP. This lets TCP do its thing, while not burdening * forwarding or ICMP with the overhead of cloning a route. * Of course, we still want to do any cloning requested by * the link layer, as this is probably required in all cases * for correct operation (as it is for ARP). */ if (ro->ro_rt == 0) rtalloc_ign(ro, RTF_PRCLONING); 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; ro->ro_rt->rt_use++; if (ro->ro_rt->rt_flags & RTF_GATEWAY) dst = (struct sockaddr_in *)ro->ro_rt->rt_gateway; if (ro->ro_rt->rt_flags & RTF_HOST) isbroadcast = (ro->ro_rt->rt_flags & RTF_BROADCAST); else isbroadcast = in_broadcast(dst->sin_addr, ifp); } if (IN_MULTICAST(ntohl(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 = (struct sockaddr_in *)&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; if (imo->imo_multicast_vif != -1) ip->ip_src.s_addr = ip_mcast_src(imo->imo_multicast_vif); } else ip->ip_ttl = IP_DEFAULT_MULTICAST_TTL; /* * Confirm that the outgoing interface supports multicast. */ if ((imo == NULL) || (imo->imo_multicast_vif == -1)) { if ((ifp->if_flags & IFF_MULTICAST) == 0) { ipstat.ips_noroute++; error = ENETUNREACH; goto bad; } } /* * If source address not specified yet, use address * of outgoing interface. */ if (ip->ip_src.s_addr == INADDR_ANY) { register struct in_ifaddr *ia1; for (ia1 = in_ifaddrhead.tqh_first; ia1; ia1 = ia1->ia_link.tqe_next) if (ia1->ia_ifp == ifp) { ip->ip_src = IA_SIN(ia1)->sin_addr; break; } } 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, hlen); } 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. */ if (ip_mrouter && (flags & IP_FORWARDING) == 0) { /* * Check if rsvp daemon is running. If not, don't * set ip_moptions. This ensures that the packet * is multicast and not just sent down one link * as prescribed by rsvpd. */ if (!rsvp_on) imo = NULL; if (ip_mforward(ip, ifp, m, imo) != 0) { m_freem(m); goto done; } } } /* * Multicasts with a time-to-live of zero may be looped- * back, above, but must not be transmitted on a network. * Also, multicasts addressed to the loopback interface * are not sent -- the above call to ip_mloopback() will * loop back a copy if this host actually belongs to the * destination group on the loopback interface. */ if (ip->ip_ttl == 0 || ifp->if_flags & IFF_LOOPBACK) { m_freem(m); goto done; } goto sendit; } #ifndef notdef /* * If source address not specified yet, use address * of outgoing interface. */ if (ip->ip_src.s_addr == INADDR_ANY) { ip->ip_src = IA_SIN(ia)->sin_addr; #ifdef IPFIREWALL_FORWARD /* Keep note that we did this - if the firewall changes * the next-hop, our interface may change, changing the * default source IP. It's a shame so much effort happens * twice. Oh well. */ fwd_rewrite_src++; #endif /* IPFIREWALL_FORWARD */ } #endif /* notdef */ /* * Verify that we have any chance at all of being able to queue * the packet or packet fragments */ if ((ifp->if_snd.ifq_len + ip->ip_len / ifp->if_mtu + 1) >= ifp->if_snd.ifq_maxlen) { error = ENOBUFS; goto bad; } /* * Look for broadcast address and * 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 ((u_short)ip->ip_len > ifp->if_mtu) { error = EMSGSIZE; goto bad; } m->m_flags |= M_BCAST; } else { m->m_flags &= ~M_BCAST; } sendit: /* * IpHack's section. * - Xlate: translate packet's addr/port (NAT). * - Firewall: deny/allow/etc. * - Wrap: fake packet's addr/port * - Encapsulate: put it in another IP and send out. */ if (fr_checkp) { struct mbuf *m1 = m; if ((error = (*fr_checkp)(ip, hlen, ifp, 1, &m1)) || !m1) goto done; ip = mtod(m = m1, struct ip *); } /* * Check with the firewall... */ if (fw_enable && ip_fw_chk_ptr) { struct sockaddr_in *old = dst; off = (*ip_fw_chk_ptr)(&ip, hlen, ifp, &divert_cookie, &m, &rule, &dst); /* * On return we must do the following: * m == NULL -> drop the pkt * 1<=off<= 0xffff -> DIVERT * (off & 0x10000) -> send to a DUMMYNET pipe * (off & 0x20000) -> TEE the packet * dst != old -> IPFIREWALL_FORWARD * off==0, dst==old -> accept * If some of the above modules is not compiled in, then * we should't have to check the corresponding condition * (because the ipfw control socket should not accept * unsupported rules), but better play safe and drop * packets in case of doubt. */ if (!m) { /* firewall said to reject */ error = EACCES; goto done; } if (off == 0 && dst == old) /* common case */ goto pass ; #ifdef DUMMYNET if ((off & IP_FW_PORT_DYNT_FLAG) != 0) { /* * pass the pkt to dummynet. Need to include * pipe number, m, ifp, ro, dst because these are * not recomputed in the next pass. * All other parameters have been already used and * so they are not needed anymore. * XXX note: if the ifp or ro entry are deleted * while a pkt is in dummynet, we are in trouble! */ dummynet_io(off & 0xffff, DN_TO_IP_OUT, m,ifp,ro,dst,rule, flags); goto done; } #endif #ifdef IPDIVERT if (off != 0 && (off & IP_FW_PORT_DYNT_FLAG) == 0) { struct mbuf *clone = NULL; /* Clone packet if we're doing a 'tee' */ if ((off & IP_FW_PORT_TEE_FLAG) != 0) clone = m_dup(m, M_DONTWAIT); /* Restore packet header fields to original values */ HTONS(ip->ip_len); HTONS(ip->ip_off); /* Deliver packet to divert input routine */ ip_divert_cookie = divert_cookie; divert_packet(m, 0, off & 0xffff); /* If 'tee', continue with original packet */ if (clone != NULL) { m = clone; ip = mtod(m, struct ip *); goto pass; } goto done; } #endif #ifdef IPFIREWALL_FORWARD /* Here we check dst to make sure it's directly reachable on the * interface we previously thought it was. * If it isn't (which may be likely in some situations) we have * to re-route it (ie, find a route for the next-hop and the * associated interface) and set them here. This is nested * forwarding which in most cases is undesirable, except where * such control is nigh impossible. So we do it here. * And I'm babbling. */ if (off == 0 && old != dst) { struct in_ifaddr *ia; /* It's changed... */ /* There must be a better way to do this next line... */ static struct route sro_fwd, *ro_fwd = &sro_fwd; #ifdef IPFIREWALL_FORWARD_DEBUG printf("IPFIREWALL_FORWARD: New dst ip: "); print_ip(dst->sin_addr); printf("\n"); #endif /* * We need to figure out if we have been forwarded * to a local socket. If so then we should somehow * "loop back" to ip_input, and get directed to the * PCB as if we had received this packet. This is * because it may be dificult to identify the packets * you want to forward until they are being output * and have selected an interface. (e.g. locally * initiated packets) If we used the loopback inteface, * we would not be able to control what happens * as the packet runs through ip_input() as * it is done through a ISR. */ for (ia = TAILQ_FIRST(&in_ifaddrhead); ia; ia = TAILQ_NEXT(ia, ia_link)) { /* * If the addr to forward to is one * of ours, we pretend to * be the destination for this packet. */ if (IA_SIN(ia)->sin_addr.s_addr == dst->sin_addr.s_addr) break; } if (ia) { /* tell ip_input "dont filter" */ ip_fw_fwd_addr = dst; if (m->m_pkthdr.rcvif == NULL) m->m_pkthdr.rcvif = ifunit("lo0"); ip->ip_len = htons((u_short)ip->ip_len); ip->ip_off = htons((u_short)ip->ip_off); ip->ip_sum = 0; if (ip->ip_vhl == IP_VHL_BORING) { ip->ip_sum = in_cksum_hdr(ip); } else { ip->ip_sum = in_cksum(m, hlen); } ip_input(m); goto done; } /* Some of the logic for this was * nicked from above. * * This rewrites the cached route in a local PCB. * Is this what we want to do? */ bcopy(dst, &ro_fwd->ro_dst, sizeof(*dst)); ro_fwd->ro_rt = 0; rtalloc_ign(ro_fwd, RTF_PRCLONING); if (ro_fwd->ro_rt == 0) { ipstat.ips_noroute++; error = EHOSTUNREACH; goto bad; } ia = ifatoia(ro_fwd->ro_rt->rt_ifa); ifp = ro_fwd->ro_rt->rt_ifp; ro_fwd->ro_rt->rt_use++; if (ro_fwd->ro_rt->rt_flags & RTF_GATEWAY) dst = (struct sockaddr_in *)ro_fwd->ro_rt->rt_gateway; if (ro_fwd->ro_rt->rt_flags & RTF_HOST) isbroadcast = (ro_fwd->ro_rt->rt_flags & RTF_BROADCAST); else isbroadcast = in_broadcast(dst->sin_addr, ifp); RTFREE(ro->ro_rt); ro->ro_rt = ro_fwd->ro_rt; dst = (struct sockaddr_in *)&ro_fwd->ro_dst; /* * If we added a default src ip earlier, * which would have been gotten from the-then * interface, do it again, from the new one. */ if (fwd_rewrite_src) ip->ip_src = IA_SIN(ia)->sin_addr; goto pass ; } #endif /* IPFIREWALL_FORWARD */ /* * if we get here, none of the above matches, and * we have to drop the pkt */ m_freem(m); error = EACCES; /* not sure this is the right error msg */ goto done; } pass: #ifdef IPSEC /* get SP for this packet */ if (so == NULL) sp = ipsec4_getpolicybyaddr(m, IPSEC_DIR_OUTBOUND, flags, &error); else sp = ipsec4_getpolicybysock(m, IPSEC_DIR_OUTBOUND, so, &error); if (sp == NULL) { ipsecstat.out_inval++; goto bad; } error = 0; /* check policy */ switch (sp->policy) { case IPSEC_POLICY_DISCARD: /* * This packet is just discarded. */ ipsecstat.out_polvio++; goto bad; case IPSEC_POLICY_BYPASS: case IPSEC_POLICY_NONE: /* no need to do IPsec. */ goto skip_ipsec; case IPSEC_POLICY_IPSEC: if (sp->req == NULL) { /* XXX should be panic ? */ printf("ip_output: No IPsec request specified.\n"); error = EINVAL; goto bad; } break; case IPSEC_POLICY_ENTRUST: default: printf("ip_output: Invalid policy found. %d\n", sp->policy); } ip->ip_len = htons((u_short)ip->ip_len); ip->ip_off = htons((u_short)ip->ip_off); ip->ip_sum = 0; { struct ipsec_output_state state; bzero(&state, sizeof(state)); state.m = m; if (flags & IP_ROUTETOIF) { state.ro = &iproute; bzero(&iproute, sizeof(iproute)); } else state.ro = ro; state.dst = (struct sockaddr *)dst; error = ipsec4_output(&state, sp, flags); m = state.m; if (flags & IP_ROUTETOIF) { /* * if we have tunnel mode SA, we may need to ignore * IP_ROUTETOIF. */ if (state.ro != &iproute || state.ro->ro_rt != NULL) { flags &= ~IP_ROUTETOIF; ro = state.ro; } } else ro = state.ro; dst = (struct sockaddr_in *)state.dst; if (error) { /* mbuf is already reclaimed in ipsec4_output. */ m0 = NULL; switch (error) { case EHOSTUNREACH: case ENETUNREACH: case EMSGSIZE: case ENOBUFS: case ENOMEM: break; default: printf("ip4_output (ipsec): error code %d\n", error); /*fall through*/ case ENOENT: /* don't show these error codes to the user */ error = 0; break; } goto bad; } } /* be sure to update variables that are affected by ipsec4_output() */ ip = mtod(m, struct ip *); #ifdef _IP_VHL hlen = IP_VHL_HL(ip->ip_vhl) << 2; #else hlen = ip->ip_hl << 2; #endif if (ro->ro_rt == NULL) { if ((flags & IP_ROUTETOIF) == 0) { printf("ip_output: " "can't update route after IPsec processing\n"); error = EHOSTUNREACH; /*XXX*/ goto bad; } } else { /* nobody uses ia beyond here */ ifp = ro->ro_rt->rt_ifp; } /* make it flipped, again. */ ip->ip_len = ntohs((u_short)ip->ip_len); ip->ip_off = ntohs((u_short)ip->ip_off); skip_ipsec: #endif /*IPSEC*/ /* * If small enough for interface, can just send directly. */ if ((u_short)ip->ip_len <= ifp->if_mtu) { ip->ip_len = htons((u_short)ip->ip_len); ip->ip_off = htons((u_short)ip->ip_off); ip->ip_sum = 0; if (ip->ip_vhl == IP_VHL_BORING) { ip->ip_sum = in_cksum_hdr(ip); } else { ip->ip_sum = in_cksum(m, hlen); } error = (*ifp->if_output)(ifp, m, (struct sockaddr *)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) { error = EMSGSIZE; /* * This case can happen if the user changed the MTU * of an interface after enabling IP on it. Because * most netifs don't keep track of routes pointing to * them, there is no way for one to update all its * routes when the MTU is changed. */ if ((ro->ro_rt->rt_flags & (RTF_UP | RTF_HOST)) && !(ro->ro_rt->rt_rmx.rmx_locks & RTV_MTU) && (ro->ro_rt->rt_rmx.rmx_mtu > ifp->if_mtu)) { ro->ro_rt->rt_rmx.rmx_mtu = ifp->if_mtu; } ipstat.ips_cantfrag++; goto bad; } len = (ifp->if_mtu - hlen) &~ 7; if (len < 8) { error = EMSGSIZE; goto bad; } { int mhlen, firstlen = len; struct mbuf **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 < (u_short)ip->ip_len; off += len) { MGETHDR(m, M_DONTWAIT, MT_HEADER); if (m == 0) { error = ENOBUFS; ipstat.ips_odropped++; goto sendorfree; } m->m_flags |= (m0->m_flags & M_MCAST); m->m_data += max_linkhdr; mhip = mtod(m, struct ip *); *mhip = *ip; if (hlen > sizeof (struct ip)) { mhlen = ip_optcopy(ip, mhip) + sizeof (struct ip); mhip->ip_vhl = IP_MAKE_VHL(IPVERSION, mhlen >> 2); } m->m_len = mhlen; mhip->ip_off = ((off - hlen) >> 3) + (ip->ip_off & ~IP_MF); if (ip->ip_off & IP_MF) mhip->ip_off |= IP_MF; if (off + len >= (u_short)ip->ip_len) len = (u_short)ip->ip_len - off; else mhip->ip_off |= IP_MF; mhip->ip_len = htons((u_short)(len + mhlen)); m->m_next = m_copy(m0, off, len); if (m->m_next == 0) { (void) m_free(m); error = ENOBUFS; /* ??? */ ipstat.ips_odropped++; goto sendorfree; } m->m_pkthdr.len = mhlen + len; m->m_pkthdr.rcvif = (struct ifnet *)0; mhip->ip_off = htons((u_short)mhip->ip_off); mhip->ip_sum = 0; if (mhip->ip_vhl == IP_VHL_BORING) { mhip->ip_sum = in_cksum_hdr(mhip); } else { mhip->ip_sum = in_cksum(m, mhlen); } *mnext = m; mnext = &m->m_nextpkt; ipstat.ips_ofragments++; } /* * Update first fragment by trimming what's been copied out * and updating header, then send each fragment (in order). */ m = m0; m_adj(m, hlen + firstlen - (u_short)ip->ip_len); m->m_pkthdr.len = hlen + firstlen; ip->ip_len = htons((u_short)m->m_pkthdr.len); ip->ip_off = htons((u_short)(ip->ip_off | IP_MF)); ip->ip_sum = 0; if (ip->ip_vhl == IP_VHL_BORING) { ip->ip_sum = in_cksum_hdr(ip); } else { ip->ip_sum = in_cksum(m, hlen); } sendorfree: for (m = m0; m; m = m0) { m0 = m->m_nextpkt; m->m_nextpkt = 0; if (error == 0) error = (*ifp->if_output)(ifp, m, (struct sockaddr *)dst, ro->ro_rt); else m_freem(m); } if (error == 0) ipstat.ips_fragmented++; } done: #ifdef IPSEC if (ro == &iproute && ro->ro_rt) { RTFREE(ro->ro_rt); ro->ro_rt = NULL; } if (sp != NULL) { KEYDEBUG(KEYDEBUG_IPSEC_STAMP, printf("DP ip_output call free SP:%p\n", sp)); key_freesp(sp); } #endif /* IPSEC */ return (error); bad: m_freem(m0); goto done; } /* * Insert IP options into preformed packet. * Adjust IP destination as required for IP source routing, * as indicated by a non-zero in_addr at the start of the options. * * XXX This routine assumes that the packet has no options in place. */ static struct mbuf * ip_insertoptions(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_short)ip->ip_len > IP_MAXPACKET) return (m); /* XXX should fail */ if (p->ipopt_dst.s_addr) ip->ip_dst = p->ipopt_dst; if (m->m_flags & M_EXT || m->m_data - optlen < m->m_pktdat) { MGETHDR(n, M_DONTWAIT, MT_HEADER); if (n == 0) return (m); n->m_pkthdr.rcvif = (struct ifnet *)0; n->m_pkthdr.len = m->m_pkthdr.len + optlen; m->m_len -= sizeof(struct ip); m->m_data += sizeof(struct ip); n->m_next = m; m = n; m->m_len = optlen + sizeof(struct ip); m->m_data += max_linkhdr; (void)memcpy(mtod(m, void *), ip, sizeof(struct ip)); } else { m->m_data -= optlen; m->m_len += optlen; m->m_pkthdr.len += optlen; ovbcopy((caddr_t)ip, mtod(m, caddr_t), sizeof(struct ip)); } ip = mtod(m, struct ip *); bcopy(p->ipopt_list, ip + 1, optlen); *phlen = sizeof(struct ip) + optlen; ip->ip_vhl = IP_MAKE_VHL(IPVERSION, *phlen >> 2); ip->ip_len += optlen; return (m); } /* * Copy options from ip to jp, * omitting those not copied during fragmentation. */ 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_VHL_HL(ip->ip_vhl) << 2) - sizeof (struct ip); for (; cnt > 0; cnt -= optlen, cp += optlen) { opt = cp[0]; if (opt == IPOPT_EOL) break; if (opt == IPOPT_NOP) { /* Preserve for IP mcast tunnel's LSRR alignment. */ *dp++ = IPOPT_NOP; optlen = 1; continue; } else optlen = cp[IPOPT_OLEN]; /* bogus lengths should have been caught by ip_dooptions */ if (optlen > cnt) optlen = cnt; if (IPOPT_COPIED(opt)) { bcopy(cp, dp, optlen); dp += optlen; } } for (optlen = dp - (u_char *)(jp+1); optlen & 0x3; optlen++) *dp++ = IPOPT_EOL; return (optlen); } /* * IP socket option processing. */ int ip_ctloutput(so, sopt) struct socket *so; struct sockopt *sopt; { struct inpcb *inp = sotoinpcb(so); int error, optval; error = optval = 0; if (sopt->sopt_level != IPPROTO_IP) { return (EINVAL); } switch (sopt->sopt_dir) { case SOPT_SET: switch (sopt->sopt_name) { case IP_OPTIONS: #ifdef notyet case IP_RETOPTS: #endif { struct mbuf *m; if (sopt->sopt_valsize > MLEN) { error = EMSGSIZE; break; } MGET(m, sopt->sopt_p ? M_WAIT : M_DONTWAIT, MT_HEADER); if (m == 0) { error = ENOBUFS; break; } m->m_len = sopt->sopt_valsize; error = sooptcopyin(sopt, mtod(m, char *), m->m_len, m->m_len); return (ip_pcbopts(sopt->sopt_name, &inp->inp_options, m)); } case IP_TOS: case IP_TTL: case IP_RECVOPTS: case IP_RECVRETOPTS: case IP_RECVDSTADDR: case IP_RECVIF: #if defined(NFAITH) && NFAITH > 0 case IP_FAITH: #endif error = sooptcopyin(sopt, &optval, sizeof optval, sizeof optval); if (error) break; switch (sopt->sopt_name) { case IP_TOS: inp->inp_ip_tos = optval; break; case IP_TTL: inp->inp_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; #if defined(NFAITH) && NFAITH > 0 case IP_FAITH: OPTSET(INP_FAITH); break; #endif } break; #undef OPTSET case IP_MULTICAST_IF: case IP_MULTICAST_VIF: case IP_MULTICAST_TTL: case IP_MULTICAST_LOOP: case IP_ADD_MEMBERSHIP: case IP_DROP_MEMBERSHIP: error = ip_setmoptions(sopt, &inp->inp_moptions); break; case IP_PORTRANGE: error = sooptcopyin(sopt, &optval, sizeof optval, sizeof optval); if (error) break; switch (optval) { case IP_PORTRANGE_DEFAULT: inp->inp_flags &= ~(INP_LOWPORT); inp->inp_flags &= ~(INP_HIGHPORT); break; case IP_PORTRANGE_HIGH: inp->inp_flags &= ~(INP_LOWPORT); inp->inp_flags |= INP_HIGHPORT; break; case IP_PORTRANGE_LOW: inp->inp_flags &= ~(INP_HIGHPORT); inp->inp_flags |= INP_LOWPORT; break; default: error = EINVAL; break; } break; #ifdef IPSEC case IP_IPSEC_POLICY: { caddr_t req; int priv; struct mbuf *m; int optname; if ((error = soopt_getm(sopt, &m)) != 0) /* XXX */ break; if ((error = soopt_mcopyin(sopt, m)) != 0) /* XXX */ break; priv = (sopt->sopt_p != NULL && suser(sopt->sopt_p) != 0) ? 0 : 1; req = mtod(m, caddr_t); optname = sopt->sopt_name; error = ipsec4_set_policy(inp, optname, req, priv); m_freem(m); break; } #endif /*IPSEC*/ default: error = ENOPROTOOPT; break; } break; case SOPT_GET: switch (sopt->sopt_name) { case IP_OPTIONS: case IP_RETOPTS: if (inp->inp_options) error = sooptcopyout(sopt, mtod(inp->inp_options, char *), inp->inp_options->m_len); else sopt->sopt_valsize = 0; break; case IP_TOS: case IP_TTL: case IP_RECVOPTS: case IP_RECVRETOPTS: case IP_RECVDSTADDR: case IP_RECVIF: case IP_PORTRANGE: #if defined(NFAITH) && NFAITH > 0 case IP_FAITH: #endif switch (sopt->sopt_name) { case IP_TOS: optval = inp->inp_ip_tos; break; case IP_TTL: optval = inp->inp_ip_ttl; break; #define OPTBIT(bit) (inp->inp_flags & bit ? 1 : 0) case IP_RECVOPTS: optval = OPTBIT(INP_RECVOPTS); break; case IP_RECVRETOPTS: optval = OPTBIT(INP_RECVRETOPTS); break; case IP_RECVDSTADDR: optval = OPTBIT(INP_RECVDSTADDR); break; case IP_RECVIF: optval = OPTBIT(INP_RECVIF); break; case IP_PORTRANGE: if (inp->inp_flags & INP_HIGHPORT) optval = IP_PORTRANGE_HIGH; else if (inp->inp_flags & INP_LOWPORT) optval = IP_PORTRANGE_LOW; else optval = 0; break; #if defined(NFAITH) && NFAITH > 0 case IP_FAITH: optval = OPTBIT(INP_FAITH); break; #endif } error = sooptcopyout(sopt, &optval, sizeof optval); break; case IP_MULTICAST_IF: case IP_MULTICAST_VIF: case IP_MULTICAST_TTL: case IP_MULTICAST_LOOP: case IP_ADD_MEMBERSHIP: case IP_DROP_MEMBERSHIP: error = ip_getmoptions(sopt, inp->inp_moptions); break; #ifdef IPSEC case IP_IPSEC_POLICY: { struct mbuf *m; caddr_t req = NULL; if (m != 0) req = mtod(m, caddr_t); error = ipsec4_get_policy(sotoinpcb(so), req, &m); if (error == 0) error = soopt_mcopyout(sopt, m); /* XXX */ m_freem(m); break; } #endif /*IPSEC*/ default: error = ENOPROTOOPT; break; } break; } return (error); } /* * Set up IP options in pcb for insertion in output packets. * Store in mbuf with pointer in pcbopt, adding pseudo-option * with destination address if source routed. */ static int ip_pcbopts(optname, pcbopt, m) int optname; 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); } /* * XXX * The whole multicast option thing needs to be re-thought. * Several of these options are equally applicable to non-multicast * transmission, and one (IP_MULTICAST_TTL) totally duplicates a * standard option (IP_TTL). */ /* * Set the IP multicast options in response to user setsockopt(). */ static int ip_setmoptions(sopt, imop) struct sockopt *sopt; struct ip_moptions **imop; { int error = 0; int i; struct in_addr addr; struct ip_mreq mreq; struct ifnet *ifp; struct ip_moptions *imo = *imop; struct route ro; struct sockaddr_in *dst; int s; 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_vif = -1; imo->imo_multicast_ttl = IP_DEFAULT_MULTICAST_TTL; imo->imo_multicast_loop = IP_DEFAULT_MULTICAST_LOOP; imo->imo_num_memberships = 0; } switch (sopt->sopt_name) { /* store an index number for the vif you wanna use in the send */ case IP_MULTICAST_VIF: if (legal_vif_num == 0) { error = EOPNOTSUPP; break; } error = sooptcopyin(sopt, &i, sizeof i, sizeof i); if (error) break; if (!legal_vif_num(i) && (i != -1)) { error = EINVAL; break; } imo->imo_multicast_vif = i; break; case IP_MULTICAST_IF: /* * Select the interface for outgoing multicast packets. */ error = sooptcopyin(sopt, &addr, sizeof 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 (addr.s_addr == INADDR_ANY) { 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. */ s = splimp(); INADDR_TO_IFP(addr, ifp); if (ifp == NULL || (ifp->if_flags & IFF_MULTICAST) == 0) { splx(s); error = EADDRNOTAVAIL; break; } imo->imo_multicast_ifp = ifp; splx(s); break; case IP_MULTICAST_TTL: /* * Set the IP time-to-live for outgoing multicast packets. * The original multicast API required a char argument, * which is inconsistent with the rest of the socket API. * We allow either a char or an int. */ if (sopt->sopt_valsize == 1) { u_char ttl; error = sooptcopyin(sopt, &ttl, 1, 1); if (error) break; imo->imo_multicast_ttl = ttl; } else { u_int ttl; error = sooptcopyin(sopt, &ttl, sizeof ttl, sizeof ttl); if (error) break; if (ttl > 255) error = EINVAL; else imo->imo_multicast_ttl = ttl; } break; case IP_MULTICAST_LOOP: /* * Set the loopback flag for outgoing multicast packets. * Must be zero or one. The original multicast API required a * char argument, which is inconsistent with the rest * of the socket API. We allow either a char or an int. */ if (sopt->sopt_valsize == 1) { u_char loop; error = sooptcopyin(sopt, &loop, 1, 1); if (error) break; imo->imo_multicast_loop = !!loop; } else { u_int loop; error = sooptcopyin(sopt, &loop, sizeof loop, sizeof loop); if (error) break; imo->imo_multicast_loop = !!loop; } break; case IP_ADD_MEMBERSHIP: /* * Add a multicast group membership. * Group must be a valid IP multicast address. */ error = sooptcopyin(sopt, &mreq, sizeof mreq, sizeof mreq); if (error) break; if (!IN_MULTICAST(ntohl(mreq.imr_multiaddr.s_addr))) { error = EINVAL; break; } s = splimp(); /* * If no interface address was provided, use the interface of * the route to the given multicast address. */ if (mreq.imr_interface.s_addr == INADDR_ANY) { bzero((caddr_t)&ro, sizeof(ro)); dst = (struct sockaddr_in *)&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; splx(s); 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; splx(s); 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 && imo->imo_membership[i]->inm_addr.s_addr == mreq.imr_multiaddr.s_addr) break; } if (i < imo->imo_num_memberships) { error = EADDRINUSE; splx(s); break; } if (i == IP_MAX_MEMBERSHIPS) { error = ETOOMANYREFS; splx(s); 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; splx(s); break; } ++imo->imo_num_memberships; splx(s); break; case IP_DROP_MEMBERSHIP: /* * Drop a multicast group membership. * Group must be a valid IP multicast address. */ error = sooptcopyin(sopt, &mreq, sizeof mreq, sizeof mreq); if (error) break; if (!IN_MULTICAST(ntohl(mreq.imr_multiaddr.s_addr))) { error = EINVAL; break; } s = splimp(); /* * If an interface address was specified, get a pointer * to its ifnet structure. */ if (mreq.imr_interface.s_addr == INADDR_ANY) ifp = NULL; else { INADDR_TO_IFP(mreq.imr_interface, ifp); if (ifp == NULL) { error = EADDRNOTAVAIL; splx(s); 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) && imo->imo_membership[i]->inm_addr.s_addr == mreq.imr_multiaddr.s_addr) break; } if (i == imo->imo_num_memberships) { error = EADDRNOTAVAIL; splx(s); 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; splx(s); 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_vif == -1 && 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(). */ static int ip_getmoptions(sopt, imo) struct sockopt *sopt; register struct ip_moptions *imo; { struct in_addr addr; struct in_ifaddr *ia; int error, optval; u_char coptval; error = 0; switch (sopt->sopt_name) { case IP_MULTICAST_VIF: if (imo != NULL) optval = imo->imo_multicast_vif; else optval = -1; error = sooptcopyout(sopt, &optval, sizeof optval); break; case IP_MULTICAST_IF: if (imo == NULL || imo->imo_multicast_ifp == NULL) addr.s_addr = INADDR_ANY; else { IFP_TO_IA(imo->imo_multicast_ifp, ia); addr.s_addr = (ia == NULL) ? INADDR_ANY : IA_SIN(ia)->sin_addr.s_addr; } error = sooptcopyout(sopt, &addr, sizeof addr); break; case IP_MULTICAST_TTL: if (imo == 0) optval = coptval = IP_DEFAULT_MULTICAST_TTL; else optval = coptval = imo->imo_multicast_ttl; if (sopt->sopt_valsize == 1) error = sooptcopyout(sopt, &coptval, 1); else error = sooptcopyout(sopt, &optval, sizeof optval); break; case IP_MULTICAST_LOOP: if (imo == 0) optval = coptval = IP_DEFAULT_MULTICAST_LOOP; else optval = coptval = imo->imo_multicast_loop; if (sopt->sopt_valsize == 1) error = sooptcopyout(sopt, &coptval, 1); else error = sooptcopyout(sopt, &optval, sizeof optval); break; default: error = ENOPROTOOPT; break; } return (error); } /* * 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 a loopback interface -- evil, but easier than * replicating that code here. */ static void ip_mloopback(ifp, m, dst, hlen) struct ifnet *ifp; register struct mbuf *m; register struct sockaddr_in *dst; int hlen; { register struct ip *ip; struct mbuf *copym; copym = m_copy(m, 0, M_COPYALL); if (copym != NULL && (copym->m_flags & M_EXT || copym->m_len < hlen)) copym = m_pullup(copym, hlen); 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 *); ip->ip_len = htons((u_short)ip->ip_len); ip->ip_off = htons((u_short)ip->ip_off); ip->ip_sum = 0; if (ip->ip_vhl == IP_VHL_BORING) { ip->ip_sum = in_cksum_hdr(ip); } else { ip->ip_sum = in_cksum(copym, hlen); } /* * NB: * It's not clear whether there are any lingering * reentrancy problems in other areas which might * be exposed by using ip_input directly (in * particular, everything which modifies the packet * in-place). Yet another option is using the * protosw directly to deliver the looped back * packet. For the moment, we'll err on the side * of safety by using if_simloop(). */ #if 1 /* XXX */ if (dst->sin_family != AF_INET) { printf("ip_mloopback: bad address family %d\n", dst->sin_family); dst->sin_family = AF_INET; } #endif #ifdef notdef copym->m_pkthdr.rcvif = ifp; ip_input(copym); #else if_simloop(ifp, copym, (struct sockaddr *)dst, 0); #endif } }