/*- * 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. * 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 __FBSDID("$FreeBSD$"); #include "opt_inet.h" #include "opt_ipfw.h" #include "opt_ipsec.h" #include "opt_kdtrace.h" #include "opt_mbuf_stress_test.h" #include "opt_mpath.h" #include "opt_route.h" #include "opt_sctp.h" #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #ifdef RADIX_MPATH #include #endif #include #include #include #include #include #include #include #include #include #ifdef SCTP #include #include #endif #ifdef IPSEC #include #include #endif /* IPSEC*/ #include #include VNET_DEFINE(u_short, ip_id); #ifdef MBUF_STRESS_TEST static int mbuf_frag_size = 0; SYSCTL_INT(_net_inet_ip, OID_AUTO, mbuf_frag_size, CTLFLAG_RW, &mbuf_frag_size, 0, "Fragment outgoing mbufs to this size"); #endif static void ip_mloopback (struct ifnet *, struct mbuf *, struct sockaddr_in *, int); extern int in_mcast_loop; 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. * If route ro is present and has ro_rt initialized, route lookup would be * skipped and ro->ro_rt would be used. If ro is present but ro->ro_rt is NULL, * then result of route lookup is stored in ro->ro_rt. * * In the IP forwarding case, the packet will arrive with options already * inserted, so must have a NULL opt pointer. */ int ip_output(struct mbuf *m, struct mbuf *opt, struct route *ro, int flags, struct ip_moptions *imo, struct inpcb *inp) { struct ip *ip; struct ifnet *ifp = NULL; /* keep compiler happy */ struct mbuf *m0; int hlen = sizeof (struct ip); int mtu; int n; /* scratchpad */ int error = 0; struct sockaddr_in *dst; const struct sockaddr_in *gw; struct in_ifaddr *ia; int isbroadcast; uint16_t ip_len, ip_off; struct route iproute; struct rtentry *rte; /* cache for ro->ro_rt */ struct in_addr odst; struct m_tag *fwd_tag = NULL; #ifdef IPSEC int no_route_but_check_spd = 0; #endif M_ASSERTPKTHDR(m); if (inp != NULL) { INP_LOCK_ASSERT(inp); M_SETFIB(m, inp->inp_inc.inc_fibnum); if (inp->inp_flags & (INP_HW_FLOWID|INP_SW_FLOWID)) { m->m_pkthdr.flowid = inp->inp_flowid; m->m_flags |= M_FLOWID; } } if (ro == NULL) { ro = &iproute; bzero(ro, sizeof (*ro)); } #ifdef FLOWTABLE if (ro->ro_rt == NULL) (void )flowtable_lookup(AF_INET, m, ro); #endif if (opt) { int len = 0; m = ip_insertoptions(m, opt, &len); if (len != 0) hlen = len; /* ip->ip_hl is updated above */ } ip = mtod(m, struct ip *); ip_len = ntohs(ip->ip_len); ip_off = ntohs(ip->ip_off); /* * Fill in IP header. If we are not allowing fragmentation, * then the ip_id field is meaningless, but we don't set it * to zero. Doing so causes various problems when devices along * the path (routers, load balancers, firewalls, etc.) illegally * disable DF on our packet. Note that a 16-bit counter * will wrap around in less than 10 seconds at 100 Mbit/s on a * medium with MTU 1500. See Steven M. Bellovin, "A Technique * for Counting NATted Hosts", Proc. IMW'02, available at * . */ if ((flags & (IP_FORWARDING|IP_RAWOUTPUT)) == 0) { ip->ip_v = IPVERSION; ip->ip_hl = hlen >> 2; ip->ip_id = ip_newid(); IPSTAT_INC(ips_localout); } else { /* Header already set, fetch hlen from there */ hlen = ip->ip_hl << 2; } /* * dst/gw handling: * * dst can be rewritten but always point to &ro->ro_dst * gw is readonly but can be pointed either to dst OR rt_gatewy * therefore we need restore GW if we're re-doing lookup */ gw = dst = (struct sockaddr_in *)&ro->ro_dst; again: ia = NULL; /* * 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. */ rte = ro->ro_rt; if (rte && ((rte->rt_flags & RTF_UP) == 0 || rte->rt_ifp == NULL || !RT_LINK_IS_UP(rte->rt_ifp) || dst->sin_family != AF_INET || dst->sin_addr.s_addr != ip->ip_dst.s_addr)) { RO_RTFREE(ro); ro->ro_lle = NULL; rte = NULL; gw = dst; } if (rte == NULL && fwd_tag == NULL) { bzero(dst, sizeof(*dst)); 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. * The use of an all-ones broadcast address implies this; an * interface is specified by the broadcast address of an interface, * or the destination address of a ptp interface. */ if (flags & IP_SENDONES) { if ((ia = ifatoia(ifa_ifwithbroadaddr(sintosa(dst)))) == NULL && (ia = ifatoia(ifa_ifwithdstaddr(sintosa(dst)))) == NULL) { IPSTAT_INC(ips_noroute); error = ENETUNREACH; goto bad; } ip->ip_dst.s_addr = INADDR_BROADCAST; dst->sin_addr = ip->ip_dst; ifp = ia->ia_ifp; ip->ip_ttl = 1; isbroadcast = 1; } else if (flags & IP_ROUTETOIF) { if ((ia = ifatoia(ifa_ifwithdstaddr(sintosa(dst)))) == NULL && (ia = ifatoia(ifa_ifwithnet(sintosa(dst), 0))) == NULL) { IPSTAT_INC(ips_noroute); error = ENETUNREACH; goto bad; } ifp = ia->ia_ifp; ip->ip_ttl = 1; isbroadcast = in_broadcast(dst->sin_addr, ifp); } else if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr)) && imo != NULL && imo->imo_multicast_ifp != NULL) { /* * Bypass the normal routing lookup for multicast * packets if the interface is specified. */ ifp = imo->imo_multicast_ifp; IFP_TO_IA(ifp, ia); isbroadcast = 0; /* fool gcc */ } else { /* * We 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 (rte == NULL) { #ifdef RADIX_MPATH rtalloc_mpath_fib(ro, ntohl(ip->ip_src.s_addr ^ ip->ip_dst.s_addr), inp ? inp->inp_inc.inc_fibnum : M_GETFIB(m)); #else in_rtalloc_ign(ro, 0, inp ? inp->inp_inc.inc_fibnum : M_GETFIB(m)); #endif rte = ro->ro_rt; } if (rte == NULL || rte->rt_ifp == NULL || !RT_LINK_IS_UP(rte->rt_ifp)) { #ifdef IPSEC /* * There is no route for this packet, but it is * possible that a matching SPD entry exists. */ no_route_but_check_spd = 1; mtu = 0; /* Silence GCC warning. */ goto sendit; #endif IPSTAT_INC(ips_noroute); error = EHOSTUNREACH; goto bad; } ia = ifatoia(rte->rt_ifa); ifp = rte->rt_ifp; counter_u64_add(rte->rt_pksent, 1); if (rte->rt_flags & RTF_GATEWAY) gw = (struct sockaddr_in *)rte->rt_gateway; if (rte->rt_flags & RTF_HOST) isbroadcast = (rte->rt_flags & RTF_BROADCAST); else isbroadcast = in_broadcast(gw->sin_addr, ifp); } /* * Calculate MTU. If we have a route that is up, use that, * otherwise use the interface's MTU. */ if (rte != NULL && (rte->rt_flags & (RTF_UP|RTF_HOST))) { /* * 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 (rte->rt_mtu > ifp->if_mtu) rte->rt_mtu = ifp->if_mtu; mtu = rte->rt_mtu; } else { mtu = ifp->if_mtu; } /* Catch a possible divide by zero later. */ KASSERT(mtu > 0, ("%s: mtu %d <= 0, rte=%p (rt_flags=0x%08x) ifp=%p", __func__, mtu, rte, (rte != NULL) ? rte->rt_flags : 0, ifp)); if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr))) { m->m_flags |= M_MCAST; /* * IP destination address is multicast. Make sure "gw" * still points to the address in "ro". (It may have been * changed to point to a gateway address, above.) */ gw = dst; /* * See if the caller provided any multicast options */ if (imo != NULL) { ip->ip_ttl = imo->imo_multicast_ttl; if (imo->imo_multicast_vif != -1) ip->ip_src.s_addr = ip_mcast_src ? ip_mcast_src(imo->imo_multicast_vif) : INADDR_ANY; } 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_INC(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) { /* Interface may have no addresses. */ if (ia != NULL) ip->ip_src = IA_SIN(ia)->sin_addr; } if ((imo == NULL && in_mcast_loop) || (imo && imo->imo_multicast_loop)) { /* * Loop back multicast datagram if not expressly * forbidden to do so, even if we are not a member * of the group; ip_input() will filter it later, * thus deferring a hash lookup and mutex acquisition * at the expense of a cheap copy using m_copym(). */ 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 (V_ip_mrouter && (flags & IP_FORWARDING) == 0) { /* * If rsvp daemon is not running, do not * set ip_moptions. This ensures that the packet * is multicast and not just sent down one link * as prescribed by rsvpd. */ if (!V_rsvp_on) imo = NULL; if (ip_mforward && 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. ip_input() will drop the copy if * this host does not belong 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; } /* * If the source address is not specified yet, use the address * of the outoing interface. */ if (ip->ip_src.s_addr == INADDR_ANY) { /* Interface may have no addresses. */ if (ia != NULL) { ip->ip_src = IA_SIN(ia)->sin_addr; } } /* * Verify that we have any chance at all of being able to queue the * packet or packet fragments, unless ALTQ is enabled on the given * interface in which case packetdrop should be done by queueing. */ n = ip_len / mtu + 1; /* how many fragments ? */ if ( #ifdef ALTQ (!ALTQ_IS_ENABLED(&ifp->if_snd)) && #endif /* ALTQ */ (ifp->if_snd.ifq_len + n) >= ifp->if_snd.ifq_maxlen ) { error = ENOBUFS; IPSTAT_INC(ips_odropped); ifp->if_snd.ifq_drops += n; 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 (ip_len > mtu) { error = EMSGSIZE; goto bad; } m->m_flags |= M_BCAST; } else { m->m_flags &= ~M_BCAST; } sendit: #ifdef IPSEC switch(ip_ipsec_output(&m, inp, &flags, &error)) { case 1: goto bad; case -1: goto done; case 0: default: break; /* Continue with packet processing. */ } /* * Check if there was a route for this packet; return error if not. */ if (no_route_but_check_spd) { IPSTAT_INC(ips_noroute); error = EHOSTUNREACH; goto bad; } /* Update variables that are affected by ipsec4_output(). */ ip = mtod(m, struct ip *); hlen = ip->ip_hl << 2; #endif /* IPSEC */ /* Jump over all PFIL processing if hooks are not active. */ if (!PFIL_HOOKED(&V_inet_pfil_hook)) goto passout; /* Run through list of hooks for output packets. */ odst.s_addr = ip->ip_dst.s_addr; error = pfil_run_hooks(&V_inet_pfil_hook, &m, ifp, PFIL_OUT, inp); if (error != 0 || m == NULL) goto done; ip = mtod(m, struct ip *); /* See if destination IP address was changed by packet filter. */ if (odst.s_addr != ip->ip_dst.s_addr) { m->m_flags |= M_SKIP_FIREWALL; /* If destination is now ourself drop to ip_input(). */ if (in_localip(ip->ip_dst)) { m->m_flags |= M_FASTFWD_OURS; if (m->m_pkthdr.rcvif == NULL) m->m_pkthdr.rcvif = V_loif; if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) { m->m_pkthdr.csum_flags |= CSUM_DATA_VALID | CSUM_PSEUDO_HDR; m->m_pkthdr.csum_data = 0xffff; } m->m_pkthdr.csum_flags |= CSUM_IP_CHECKED | CSUM_IP_VALID; #ifdef SCTP if (m->m_pkthdr.csum_flags & CSUM_SCTP) m->m_pkthdr.csum_flags |= CSUM_SCTP_VALID; #endif error = netisr_queue(NETISR_IP, m); goto done; } else goto again; /* Redo the routing table lookup. */ } /* See if local, if yes, send it to netisr with IP_FASTFWD_OURS. */ if (m->m_flags & M_FASTFWD_OURS) { if (m->m_pkthdr.rcvif == NULL) m->m_pkthdr.rcvif = V_loif; if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) { m->m_pkthdr.csum_flags |= CSUM_DATA_VALID | CSUM_PSEUDO_HDR; m->m_pkthdr.csum_data = 0xffff; } #ifdef SCTP if (m->m_pkthdr.csum_flags & CSUM_SCTP) m->m_pkthdr.csum_flags |= CSUM_SCTP_VALID; #endif m->m_pkthdr.csum_flags |= CSUM_IP_CHECKED | CSUM_IP_VALID; error = netisr_queue(NETISR_IP, m); goto done; } /* Or forward to some other address? */ if ((m->m_flags & M_IP_NEXTHOP) && (fwd_tag = m_tag_find(m, PACKET_TAG_IPFORWARD, NULL)) != NULL) { bcopy((fwd_tag+1), dst, sizeof(struct sockaddr_in)); m->m_flags |= M_SKIP_FIREWALL; m->m_flags &= ~M_IP_NEXTHOP; m_tag_delete(m, fwd_tag); goto again; } passout: /* 127/8 must not appear on wire - RFC1122. */ if ((ntohl(ip->ip_dst.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET || (ntohl(ip->ip_src.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET) { if ((ifp->if_flags & IFF_LOOPBACK) == 0) { IPSTAT_INC(ips_badaddr); error = EADDRNOTAVAIL; goto bad; } } m->m_pkthdr.csum_flags |= CSUM_IP; if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA & ~ifp->if_hwassist) { in_delayed_cksum(m); m->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA; } #ifdef SCTP if (m->m_pkthdr.csum_flags & CSUM_SCTP & ~ifp->if_hwassist) { sctp_delayed_cksum(m, (uint32_t)(ip->ip_hl << 2)); m->m_pkthdr.csum_flags &= ~CSUM_SCTP; } #endif /* * If small enough for interface, or the interface will take * care of the fragmentation for us, we can just send directly. */ if (ip_len <= mtu || (m->m_pkthdr.csum_flags & ifp->if_hwassist & CSUM_TSO) != 0 || ((ip_off & IP_DF) == 0 && (ifp->if_hwassist & CSUM_FRAGMENT))) { ip->ip_sum = 0; if (m->m_pkthdr.csum_flags & CSUM_IP & ~ifp->if_hwassist) { ip->ip_sum = in_cksum(m, hlen); m->m_pkthdr.csum_flags &= ~CSUM_IP; } /* * Record statistics for this interface address. * With CSUM_TSO the byte/packet count will be slightly * incorrect because we count the IP+TCP headers only * once instead of for every generated packet. */ if (!(flags & IP_FORWARDING) && ia) { if (m->m_pkthdr.csum_flags & CSUM_TSO) ia->ia_ifa.if_opackets += m->m_pkthdr.len / m->m_pkthdr.tso_segsz; else ia->ia_ifa.if_opackets++; ia->ia_ifa.if_obytes += m->m_pkthdr.len; } #ifdef MBUF_STRESS_TEST if (mbuf_frag_size && m->m_pkthdr.len > mbuf_frag_size) m = m_fragment(m, M_NOWAIT, mbuf_frag_size); #endif /* * Reset layer specific mbuf flags * to avoid confusing lower layers. */ m_clrprotoflags(m); IP_PROBE(send, NULL, NULL, ip, ifp, ip, NULL); error = (*ifp->if_output)(ifp, m, (const struct sockaddr *)gw, ro); goto done; } /* Balk when DF bit is set or the interface didn't support TSO. */ if ((ip_off & IP_DF) || (m->m_pkthdr.csum_flags & CSUM_TSO)) { error = EMSGSIZE; IPSTAT_INC(ips_cantfrag); goto bad; } /* * Too large for interface; fragment if possible. If successful, * on return, m will point to a list of packets to be sent. */ error = ip_fragment(ip, &m, mtu, ifp->if_hwassist); if (error) goto bad; for (; m; m = m0) { m0 = m->m_nextpkt; m->m_nextpkt = 0; if (error == 0) { /* Record statistics for this interface address. */ if (ia != NULL) { ia->ia_ifa.if_opackets++; ia->ia_ifa.if_obytes += m->m_pkthdr.len; } /* * Reset layer specific mbuf flags * to avoid confusing upper layers. */ m_clrprotoflags(m); IP_PROBE(send, NULL, NULL, ip, ifp, ip, NULL); error = (*ifp->if_output)(ifp, m, (const struct sockaddr *)gw, ro); } else m_freem(m); } if (error == 0) IPSTAT_INC(ips_fragmented); done: if (ro == &iproute) RO_RTFREE(ro); return (error); bad: m_freem(m); goto done; } /* * Create a chain of fragments which fit the given mtu. m_frag points to the * mbuf to be fragmented; on return it points to the chain with the fragments. * Return 0 if no error. If error, m_frag may contain a partially built * chain of fragments that should be freed by the caller. * * if_hwassist_flags is the hw offload capabilities (see if_data.ifi_hwassist) */ int ip_fragment(struct ip *ip, struct mbuf **m_frag, int mtu, u_long if_hwassist_flags) { int error = 0; int hlen = ip->ip_hl << 2; int len = (mtu - hlen) & ~7; /* size of payload in each fragment */ int off; struct mbuf *m0 = *m_frag; /* the original packet */ int firstlen; struct mbuf **mnext; int nfrags; uint16_t ip_len, ip_off; ip_len = ntohs(ip->ip_len); ip_off = ntohs(ip->ip_off); if (ip_off & IP_DF) { /* Fragmentation not allowed */ IPSTAT_INC(ips_cantfrag); return EMSGSIZE; } /* * Must be able to put at least 8 bytes per fragment. */ if (len < 8) return EMSGSIZE; /* * If the interface will not calculate checksums on * fragmented packets, then do it here. */ if (m0->m_pkthdr.csum_flags & CSUM_DELAY_DATA) { in_delayed_cksum(m0); m0->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA; } #ifdef SCTP if (m0->m_pkthdr.csum_flags & CSUM_SCTP) { sctp_delayed_cksum(m0, hlen); m0->m_pkthdr.csum_flags &= ~CSUM_SCTP; } #endif if (len > PAGE_SIZE) { /* * Fragment large datagrams such that each segment * contains a multiple of PAGE_SIZE amount of data, * plus headers. This enables a receiver to perform * page-flipping zero-copy optimizations. * * XXX When does this help given that sender and receiver * could have different page sizes, and also mtu could * be less than the receiver's page size ? */ int newlen; struct mbuf *m; for (m = m0, off = 0; m && (off+m->m_len) <= mtu; m = m->m_next) off += m->m_len; /* * firstlen (off - hlen) must be aligned on an * 8-byte boundary */ if (off < hlen) goto smart_frag_failure; off = ((off - hlen) & ~7) + hlen; newlen = (~PAGE_MASK) & mtu; if ((newlen + sizeof (struct ip)) > mtu) { /* we failed, go back the default */ smart_frag_failure: newlen = len; off = hlen + len; } len = newlen; } else { off = hlen + len; } firstlen = off - hlen; mnext = &m0->m_nextpkt; /* pointer to next packet */ /* * Loop through length of segment after first fragment, * make new header and copy data of each part and link onto chain. * Here, m0 is the original packet, m is the fragment being created. * The fragments are linked off the m_nextpkt of the original * packet, which after processing serves as the first fragment. */ for (nfrags = 1; off < ip_len; off += len, nfrags++) { struct ip *mhip; /* ip header on the fragment */ struct mbuf *m; int mhlen = sizeof (struct ip); m = m_gethdr(M_NOWAIT, MT_DATA); if (m == NULL) { error = ENOBUFS; IPSTAT_INC(ips_odropped); goto done; } m->m_flags |= (m0->m_flags & M_MCAST); /* * In the first mbuf, leave room for the link header, then * copy the original IP header including options. The payload * goes into an additional mbuf chain returned by m_copym(). */ 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_v = IPVERSION; mhip->ip_hl = mhlen >> 2; } m->m_len = mhlen; /* XXX do we need to add ip_off below ? */ mhip->ip_off = ((off - hlen) >> 3) + ip_off; if (off + len >= ip_len) len = ip_len - off; else mhip->ip_off |= IP_MF; mhip->ip_len = htons((u_short)(len + mhlen)); m->m_next = m_copym(m0, off, len, M_NOWAIT); if (m->m_next == NULL) { /* copy failed */ m_free(m); error = ENOBUFS; /* ??? */ IPSTAT_INC(ips_odropped); goto done; } m->m_pkthdr.len = mhlen + len; m->m_pkthdr.rcvif = NULL; #ifdef MAC mac_netinet_fragment(m0, m); #endif m->m_pkthdr.csum_flags = m0->m_pkthdr.csum_flags; mhip->ip_off = htons(mhip->ip_off); mhip->ip_sum = 0; if (m->m_pkthdr.csum_flags & CSUM_IP & ~if_hwassist_flags) { mhip->ip_sum = in_cksum(m, mhlen); m->m_pkthdr.csum_flags &= ~CSUM_IP; } *mnext = m; mnext = &m->m_nextpkt; } IPSTAT_ADD(ips_ofragments, nfrags); /* * Update first fragment by trimming what's been copied out * and updating header. */ m_adj(m0, hlen + firstlen - ip_len); m0->m_pkthdr.len = hlen + firstlen; ip->ip_len = htons((u_short)m0->m_pkthdr.len); ip->ip_off = htons(ip_off | IP_MF); ip->ip_sum = 0; if (m0->m_pkthdr.csum_flags & CSUM_IP & ~if_hwassist_flags) { ip->ip_sum = in_cksum(m0, hlen); m0->m_pkthdr.csum_flags &= ~CSUM_IP; } done: *m_frag = m0; return error; } void in_delayed_cksum(struct mbuf *m) { struct ip *ip; uint16_t csum, offset, ip_len; ip = mtod(m, struct ip *); offset = ip->ip_hl << 2 ; ip_len = ntohs(ip->ip_len); csum = in_cksum_skip(m, ip_len, offset); if (m->m_pkthdr.csum_flags & CSUM_UDP && csum == 0) csum = 0xffff; offset += m->m_pkthdr.csum_data; /* checksum offset */ if (offset + sizeof(u_short) > m->m_len) { printf("delayed m_pullup, m->len: %d off: %d p: %d\n", m->m_len, offset, ip->ip_p); /* * XXX * this shouldn't happen, but if it does, the * correct behavior may be to insert the checksum * in the appropriate next mbuf in the chain. */ return; } *(u_short *)(m->m_data + offset) = csum; } /* * IP socket option processing. */ int ip_ctloutput(struct socket *so, struct sockopt *sopt) { struct inpcb *inp = sotoinpcb(so); int error, optval; error = optval = 0; if (sopt->sopt_level != IPPROTO_IP) { error = EINVAL; if (sopt->sopt_level == SOL_SOCKET && sopt->sopt_dir == SOPT_SET) { switch (sopt->sopt_name) { case SO_REUSEADDR: INP_WLOCK(inp); if ((so->so_options & SO_REUSEADDR) != 0) inp->inp_flags2 |= INP_REUSEADDR; else inp->inp_flags2 &= ~INP_REUSEADDR; INP_WUNLOCK(inp); error = 0; break; case SO_REUSEPORT: INP_WLOCK(inp); if ((so->so_options & SO_REUSEPORT) != 0) inp->inp_flags2 |= INP_REUSEPORT; else inp->inp_flags2 &= ~INP_REUSEPORT; INP_WUNLOCK(inp); error = 0; break; case SO_SETFIB: INP_WLOCK(inp); inp->inp_inc.inc_fibnum = so->so_fibnum; INP_WUNLOCK(inp); error = 0; break; default: break; } } return (error); } 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; } m = m_get(sopt->sopt_td ? M_WAITOK : M_NOWAIT, MT_DATA); if (m == NULL) { error = ENOBUFS; break; } m->m_len = sopt->sopt_valsize; error = sooptcopyin(sopt, mtod(m, char *), m->m_len, m->m_len); if (error) { m_free(m); break; } INP_WLOCK(inp); error = ip_pcbopts(inp, sopt->sopt_name, m); INP_WUNLOCK(inp); return (error); } case IP_BINDANY: if (sopt->sopt_td != NULL) { error = priv_check(sopt->sopt_td, PRIV_NETINET_BINDANY); if (error) break; } /* FALLTHROUGH */ case IP_TOS: case IP_TTL: case IP_MINTTL: case IP_RECVOPTS: case IP_RECVRETOPTS: case IP_RECVDSTADDR: case IP_RECVTTL: case IP_RECVIF: case IP_FAITH: case IP_ONESBCAST: case IP_DONTFRAG: case IP_RECVTOS: 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; case IP_MINTTL: if (optval >= 0 && optval <= MAXTTL) inp->inp_ip_minttl = optval; else error = EINVAL; break; #define OPTSET(bit) do { \ INP_WLOCK(inp); \ if (optval) \ inp->inp_flags |= bit; \ else \ inp->inp_flags &= ~bit; \ INP_WUNLOCK(inp); \ } while (0) case IP_RECVOPTS: OPTSET(INP_RECVOPTS); break; case IP_RECVRETOPTS: OPTSET(INP_RECVRETOPTS); break; case IP_RECVDSTADDR: OPTSET(INP_RECVDSTADDR); break; case IP_RECVTTL: OPTSET(INP_RECVTTL); break; case IP_RECVIF: OPTSET(INP_RECVIF); break; case IP_FAITH: OPTSET(INP_FAITH); break; case IP_ONESBCAST: OPTSET(INP_ONESBCAST); break; case IP_DONTFRAG: OPTSET(INP_DONTFRAG); break; case IP_BINDANY: OPTSET(INP_BINDANY); break; case IP_RECVTOS: OPTSET(INP_RECVTOS); break; } break; #undef OPTSET /* * Multicast socket options are processed by the in_mcast * module. */ case IP_MULTICAST_IF: case IP_MULTICAST_VIF: case IP_MULTICAST_TTL: case IP_MULTICAST_LOOP: case IP_ADD_MEMBERSHIP: case IP_DROP_MEMBERSHIP: case IP_ADD_SOURCE_MEMBERSHIP: case IP_DROP_SOURCE_MEMBERSHIP: case IP_BLOCK_SOURCE: case IP_UNBLOCK_SOURCE: case IP_MSFILTER: case MCAST_JOIN_GROUP: case MCAST_LEAVE_GROUP: case MCAST_JOIN_SOURCE_GROUP: case MCAST_LEAVE_SOURCE_GROUP: case MCAST_BLOCK_SOURCE: case MCAST_UNBLOCK_SOURCE: error = inp_setmoptions(inp, sopt); break; case IP_PORTRANGE: error = sooptcopyin(sopt, &optval, sizeof optval, sizeof optval); if (error) break; INP_WLOCK(inp); 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; } INP_WUNLOCK(inp); break; #ifdef IPSEC case IP_IPSEC_POLICY: { caddr_t req; struct mbuf *m; if ((error = soopt_getm(sopt, &m)) != 0) /* XXX */ break; if ((error = soopt_mcopyin(sopt, m)) != 0) /* XXX */ break; req = mtod(m, caddr_t); error = ipsec_set_policy(inp, sopt->sopt_name, req, m->m_len, (sopt->sopt_td != NULL) ? sopt->sopt_td->td_ucred : NULL); 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_MINTTL: case IP_RECVOPTS: case IP_RECVRETOPTS: case IP_RECVDSTADDR: case IP_RECVTTL: case IP_RECVIF: case IP_PORTRANGE: case IP_FAITH: case IP_ONESBCAST: case IP_DONTFRAG: case IP_BINDANY: case IP_RECVTOS: switch (sopt->sopt_name) { case IP_TOS: optval = inp->inp_ip_tos; break; case IP_TTL: optval = inp->inp_ip_ttl; break; case IP_MINTTL: optval = inp->inp_ip_minttl; 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_RECVTTL: optval = OPTBIT(INP_RECVTTL); 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; case IP_FAITH: optval = OPTBIT(INP_FAITH); break; case IP_ONESBCAST: optval = OPTBIT(INP_ONESBCAST); break; case IP_DONTFRAG: optval = OPTBIT(INP_DONTFRAG); break; case IP_BINDANY: optval = OPTBIT(INP_BINDANY); break; case IP_RECVTOS: optval = OPTBIT(INP_RECVTOS); break; } error = sooptcopyout(sopt, &optval, sizeof optval); break; /* * Multicast socket options are processed by the in_mcast * module. */ case IP_MULTICAST_IF: case IP_MULTICAST_VIF: case IP_MULTICAST_TTL: case IP_MULTICAST_LOOP: case IP_MSFILTER: error = inp_getmoptions(inp, sopt); break; #ifdef IPSEC case IP_IPSEC_POLICY: { struct mbuf *m = NULL; caddr_t req = NULL; size_t len = 0; if (m != 0) { req = mtod(m, caddr_t); len = m->m_len; } error = ipsec_get_policy(sotoinpcb(so), req, len, &m); if (error == 0) error = soopt_mcopyout(sopt, m); /* XXX */ if (error == 0) m_freem(m); break; } #endif /* IPSEC */ default: error = ENOPROTOOPT; break; } break; } return (error); } /* * 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(struct ifnet *ifp, struct mbuf *m, struct sockaddr_in *dst, int hlen) { register struct ip *ip; struct mbuf *copym; /* * Make a deep copy of the packet because we're going to * modify the pack in order to generate checksums. */ copym = m_dup(m, M_NOWAIT); if (copym != NULL && (copym->m_flags & M_EXT || copym->m_len < hlen)) copym = m_pullup(copym, hlen); if (copym != NULL) { /* If needed, compute the checksum and mark it as valid. */ if (copym->m_pkthdr.csum_flags & CSUM_DELAY_DATA) { in_delayed_cksum(copym); copym->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA; copym->m_pkthdr.csum_flags |= CSUM_DATA_VALID | CSUM_PSEUDO_HDR; copym->m_pkthdr.csum_data = 0xffff; } /* * 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_sum = 0; ip->ip_sum = in_cksum(copym, hlen); #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 if_simloop(ifp, copym, dst->sin_family, 0); } }