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IABSD.fr/src/sys/netinet/ip_input.c
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Author :
mvs
Date : 2025-07-31 09:05:11
Hash : 5a12b7de
Message : Unlock ip6_sysctl(). Use temporary local buffer for lockless IO within ip6_sysctl_soiikey(). Use existing `sysctl_lock' rwlock(9) to protect `ip6_soiikey'. Also, replace temporary `ip_sysctl_lock' with `sysctl_lock' rwlock(9). It was introduced as temporary to avoid recursive lock acquisition in ip*_sysctl() until upcoming unlocked. The usage paths are not the hot paths, no reason to have dedicated locks for them. ok bluhm
- sys/netinet/ip_input.c
-
/* $OpenBSD: ip_input.c,v 1.425 2025/07/31 09:05:11 mvs Exp $ */ /* $NetBSD: ip_input.c,v 1.30 1996/03/16 23:53:58 christos Exp $ */ /* * Copyright (c) 1982, 1986, 1988, 1993 * The Regents of the University of California. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. Neither the name of the University nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * * @(#)ip_input.c 8.2 (Berkeley) 1/4/94 */ #include "pf.h" #include "carp.h" #include <sys/param.h> #include <sys/systm.h> #include <sys/mbuf.h> #include <sys/domain.h> #include <sys/mutex.h> #include <sys/protosw.h> #include <sys/socket.h> #include <sys/sysctl.h> #include <sys/pool.h> #include <sys/task.h> #include <net/if.h> #include <net/if_var.h> #include <net/if_dl.h> #include <net/route.h> #include <net/netisr.h> #include <netinet/in.h> #include <netinet/in_systm.h> #include <netinet/if_ether.h> #include <netinet/ip.h> #include <netinet/in_pcb.h> #include <netinet/in_var.h> #include <netinet/ip_var.h> #include <netinet/ip_icmp.h> #include <net/if_types.h> #ifdef INET6 #include <netinet6/ip6_var.h> #endif #if NPF > 0 #include <net/pfvar.h> #endif #ifdef MROUTING #include <netinet/ip_mroute.h> #endif #ifdef IPSEC #include <netinet/ip_ipsp.h> #endif /* IPSEC */ #if NCARP > 0 #include <netinet/ip_carp.h> #endif /* * Locks used to protect global variables in this file: * I immutable after creation * N net lock * Q ipq_mutex * a atomic operations */ /* values controllable via sysctl */ int ip_forwarding = 0; /* [a] */ int ipmforwarding = 0; /* [a] */ int ipmultipath = 0; /* [a] */ int ip_sendredirects = 1; /* [a] */ int ip_dosourceroute = 0; /* [a] */ int ip_defttl = IPDEFTTL; /* [a] */ int ip_mtudisc = 1; /* [a] */ int ip_mtudisc_timeout = IPMTUDISCTIMEOUT; /* [a] */ int ip_directedbcast = 0; /* [a] */ struct mutex ipq_mutex = MUTEX_INITIALIZER(IPL_SOFTNET); /* IP reassembly queue */ LIST_HEAD(, ipq) ipq; /* [Q] */ /* Keep track of memory used for reassembly */ int ip_maxqueue = 300; /* [a] */ int ip_frags = 0; /* [Q] */ #ifndef SMALL_KERNEL const struct sysctl_bounded_args ipctl_vars[] = { { IPCTL_FORWARDING, &ip_forwarding, 0, 2 }, { IPCTL_SENDREDIRECTS, &ip_sendredirects, 0, 1 }, { IPCTL_DIRECTEDBCAST, &ip_directedbcast, 0, 1 }, #ifdef MROUTING { IPCTL_MRTPROTO, &ip_mrtproto, SYSCTL_INT_READONLY }, #endif { IPCTL_DEFTTL, &ip_defttl, 0, 255 }, { IPCTL_IPPORT_FIRSTAUTO, &ipport_firstauto, 0, 65535 }, { IPCTL_IPPORT_LASTAUTO, &ipport_lastauto, 0, 65535 }, { IPCTL_IPPORT_HIFIRSTAUTO, &ipport_hifirstauto, 0, 65535 }, { IPCTL_IPPORT_HILASTAUTO, &ipport_hilastauto, 0, 65535 }, { IPCTL_IPPORT_MAXQUEUE, &ip_maxqueue, 0, 10000 }, { IPCTL_MFORWARDING, &ipmforwarding, 0, 1 }, { IPCTL_ARPTIMEOUT, &arpt_keep, 0, INT_MAX }, { IPCTL_ARPDOWN, &arpt_down, 0, INT_MAX }, }; #endif /* SMALL_KERNEL */ struct niqueue ipintrq = NIQUEUE_INITIALIZER(IPQ_MAXLEN, NETISR_IP); struct pool ipqent_pool; struct pool ipq_pool; struct cpumem *ipcounters; int ip_sysctl_ipstat(void *, size_t *, void *); static struct mbuf_queue ipsend_mq; static struct mbuf_queue ipsendraw_mq; extern struct niqueue arpinq; int ip_ours(struct mbuf **, int *, int, int, struct netstack *); int ip_ours_enqueue(struct mbuf **mp, int *offp, int nxt); int ip_dooptions(struct mbuf *, struct ifnet *, int); int in_ouraddr(struct mbuf *, struct ifnet *, struct route *, int); int ip_fragcheck(struct mbuf **, int *); struct mbuf * ip_reass(struct ipqent *, struct ipq *); void ip_freef(struct ipq *); void ip_flush(int); static void ip_send_dispatch(void *); static void ip_sendraw_dispatch(void *); static struct task ipsend_task = TASK_INITIALIZER(ip_send_dispatch, &ipsend_mq); static struct task ipsendraw_task = TASK_INITIALIZER(ip_sendraw_dispatch, &ipsendraw_mq); /* * Used to save the IP options in case a protocol wants to respond * to an incoming packet over the same route if the packet got here * using IP source routing. This allows connection establishment and * maintenance when the remote end is on a network that is not known * to us. */ struct ip_srcrt { int isr_nhops; /* number of hops */ struct in_addr isr_dst; /* final destination */ char isr_nop; /* one NOP to align */ char isr_hdr[IPOPT_OFFSET + 1]; /* OPTVAL, OLEN & OFFSET */ struct in_addr isr_routes[MAX_IPOPTLEN/sizeof(struct in_addr)]; }; void save_rte(struct mbuf *, u_char *, struct in_addr); /* * IP initialization: fill in IP protocol switch table. * All protocols not implemented in kernel go to raw IP protocol handler. */ void ip_init(void) { const struct protosw *pr; int i; const u_int16_t defbaddynamicports_tcp[] = DEFBADDYNAMICPORTS_TCP; const u_int16_t defbaddynamicports_udp[] = DEFBADDYNAMICPORTS_UDP; const u_int16_t defrootonlyports_tcp[] = DEFROOTONLYPORTS_TCP; const u_int16_t defrootonlyports_udp[] = DEFROOTONLYPORTS_UDP; ipcounters = counters_alloc(ips_ncounters); pool_init(&ipqent_pool, sizeof(struct ipqent), 0, IPL_SOFTNET, 0, "ipqe", NULL); pool_init(&ipq_pool, sizeof(struct ipq), 0, IPL_SOFTNET, 0, "ipq", NULL); pr = pffindproto(PF_INET, IPPROTO_RAW, SOCK_RAW); if (pr == NULL) panic("ip_init"); for (i = 0; i < IPPROTO_MAX; i++) ip_protox[i] = pr - inetsw; for (pr = inetdomain.dom_protosw; pr < inetdomain.dom_protoswNPROTOSW; pr++) if (pr->pr_domain->dom_family == PF_INET && pr->pr_protocol && pr->pr_protocol != IPPROTO_RAW && pr->pr_protocol < IPPROTO_MAX) ip_protox[pr->pr_protocol] = pr - inetsw; LIST_INIT(&ipq); /* Fill in list of ports not to allocate dynamically. */ memset(&baddynamicports, 0, sizeof(baddynamicports)); for (i = 0; defbaddynamicports_tcp[i] != 0; i++) DP_SET(baddynamicports.tcp, defbaddynamicports_tcp[i]); for (i = 0; defbaddynamicports_udp[i] != 0; i++) DP_SET(baddynamicports.udp, defbaddynamicports_udp[i]); /* Fill in list of ports only root can bind to. */ memset(&rootonlyports, 0, sizeof(rootonlyports)); for (i = 0; defrootonlyports_tcp[i] != 0; i++) DP_SET(rootonlyports.tcp, defrootonlyports_tcp[i]); for (i = 0; defrootonlyports_udp[i] != 0; i++) DP_SET(rootonlyports.udp, defrootonlyports_udp[i]); mq_init(&ipsend_mq, 64, IPL_SOFTNET); mq_init(&ipsendraw_mq, 64, IPL_SOFTNET); arpinit(); #ifdef IPSEC ipsec_init(); #endif #ifdef MROUTING mrt_init(); #endif } /* * Enqueue packet for local delivery. Queuing is used as a boundary * between the network layer (input/forward path) running with * NET_LOCK_SHARED() and the transport layer needing it exclusively. */ int ip_ours(struct mbuf **mp, int *offp, int nxt, int af, struct netstack *ns) { nxt = ip_fragcheck(mp, offp); if (nxt == IPPROTO_DONE) return IPPROTO_DONE; /* We are already in a IPv4/IPv6 local deliver loop. */ if (af != AF_UNSPEC) return nxt; nxt = ip_deliver(mp, offp, nxt, AF_INET, 1, ns); if (nxt == IPPROTO_DONE) return IPPROTO_DONE; return ip_ours_enqueue(mp, offp, nxt); } int ip_ours_enqueue(struct mbuf **mp, int *offp, int nxt) { /* save values for later, use after dequeue */ if (*offp != sizeof(struct ip)) { struct m_tag *mtag; struct ipoffnxt *ion; /* mbuf tags are expensive, but only used for header options */ mtag = m_tag_get(PACKET_TAG_IP_OFFNXT, sizeof(*ion), M_NOWAIT); if (mtag == NULL) { ipstat_inc(ips_idropped); m_freemp(mp); return IPPROTO_DONE; } ion = (struct ipoffnxt *)(mtag + 1); ion->ion_off = *offp; ion->ion_nxt = nxt; m_tag_prepend(*mp, mtag); } niq_enqueue(&ipintrq, *mp); *mp = NULL; return IPPROTO_DONE; } /* * Dequeue and process locally delivered packets. * This is called with exclusive NET_LOCK(). */ void ipintr(void) { struct mbuf *m; while ((m = niq_dequeue(&ipintrq)) != NULL) { struct m_tag *mtag; int off, nxt; #ifdef DIAGNOSTIC if ((m->m_flags & M_PKTHDR) == 0) panic("ipintr no HDR"); #endif mtag = m_tag_find(m, PACKET_TAG_IP_OFFNXT, NULL); if (mtag != NULL) { struct ipoffnxt *ion; ion = (struct ipoffnxt *)(mtag + 1); off = ion->ion_off; nxt = ion->ion_nxt; m_tag_delete(m, mtag); } else { struct ip *ip; ip = mtod(m, struct ip *); off = ip->ip_hl << 2; nxt = ip->ip_p; } nxt = ip_deliver(&m, &off, nxt, AF_INET, 0, NULL); KASSERT(nxt == IPPROTO_DONE); } } /* * IPv4 input routine. * * Checksum and byte swap header. Process options. Forward or deliver. */ void ipv4_input(struct ifnet *ifp, struct mbuf *m, struct netstack *ns) { int off, nxt; off = 0; nxt = ip_input_if(&m, &off, IPPROTO_IPV4, AF_UNSPEC, ifp, ns); KASSERT(nxt == IPPROTO_DONE); } struct mbuf * ipv4_check(struct ifnet *ifp, struct mbuf *m) { struct ip *ip; int hlen, len; if (m->m_len < sizeof(*ip)) { m = m_pullup(m, sizeof(*ip)); if (m == NULL) { ipstat_inc(ips_toosmall); return (NULL); } } ip = mtod(m, struct ip *); if (ip->ip_v != IPVERSION) { ipstat_inc(ips_badvers); goto bad; } hlen = ip->ip_hl << 2; if (hlen < sizeof(*ip)) { /* minimum header length */ ipstat_inc(ips_badhlen); goto bad; } if (hlen > m->m_len) { m = m_pullup(m, hlen); if (m == NULL) { ipstat_inc(ips_badhlen); return (NULL); } ip = mtod(m, struct ip *); } /* 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); goto bad; } } if (!ISSET(m->m_pkthdr.csum_flags, M_IPV4_CSUM_IN_OK)) { if (ISSET(m->m_pkthdr.csum_flags, M_IPV4_CSUM_IN_BAD)) { ipstat_inc(ips_badsum); goto bad; } ipstat_inc(ips_inswcsum); if (in_cksum(m, hlen) != 0) { ipstat_inc(ips_badsum); goto bad; } SET(m->m_pkthdr.csum_flags, M_IPV4_CSUM_IN_OK); } /* Retrieve the packet length. */ len = ntohs(ip->ip_len); /* * Convert fields to host representation. */ if (len < hlen) { ipstat_inc(ips_badlen); goto bad; } /* * Check that the amount of data in the buffers * is at least as much as the IP header would have us expect. * Trim mbufs if longer than we expect. * Drop packet if shorter than we expect. */ if (m->m_pkthdr.len < len) { ipstat_inc(ips_tooshort); goto bad; } if (m->m_pkthdr.len > len) { if (m->m_len == m->m_pkthdr.len) { m->m_len = len; m->m_pkthdr.len = len; } else m_adj(m, len - m->m_pkthdr.len); } return (m); bad: m_freem(m); return (NULL); } int ip_input_if(struct mbuf **mp, int *offp, int nxt, int af, struct ifnet *ifp, struct netstack *ns) { struct route iproute, *ro = NULL; struct mbuf *m; struct ip *ip; int hlen; #if NPF > 0 struct in_addr odst; #endif int flags = 0; KASSERT(*offp == 0); ipstat_inc(ips_total); m = *mp = ipv4_check(ifp, *mp); if (m == NULL) goto bad; ip = mtod(m, struct ip *); #if NCARP > 0 if (carp_lsdrop(ifp, m, AF_INET, &ip->ip_src.s_addr, &ip->ip_dst.s_addr, (ip->ip_p == IPPROTO_ICMP ? 0 : 1))) goto bad; #endif #if NPF > 0 /* * Packet filter */ odst = ip->ip_dst; if (pf_test(AF_INET, PF_IN, ifp, mp) != PF_PASS) goto bad; m = *mp; if (m == NULL) goto bad; ip = mtod(m, struct ip *); if (odst.s_addr != ip->ip_dst.s_addr) SET(flags, IP_REDIRECT); #endif switch (atomic_load_int(&ip_forwarding)) { case 2: SET(flags, IP_FORWARDING_IPSEC); /* FALLTHROUGH */ case 1: SET(flags, IP_FORWARDING); break; } if (atomic_load_int(&ip_directedbcast)) SET(flags, IP_ALLOWBROADCAST); hlen = ip->ip_hl << 2; /* * Process options and, if not destined for us, * ship it on. ip_dooptions returns 1 when an * error was detected (causing an icmp message * to be sent and the original packet to be freed). */ if (hlen > sizeof (struct ip) && ip_dooptions(m, ifp, flags)) { m = *mp = NULL; goto bad; } if (ns == NULL) { ro = &iproute; ro->ro_rt = NULL; } else { ro = &ns->ns_route; } switch (in_ouraddr(m, ifp, ro, flags)) { case 2: goto bad; case 1: nxt = ip_ours(mp, offp, nxt, af, ns); goto out; } if (IN_MULTICAST(ip->ip_dst.s_addr)) { /* * Make sure M_MCAST is set. It should theoretically * already be there, but let's play safe because upper * layers check for this flag. */ m->m_flags |= M_MCAST; #ifdef MROUTING if (atomic_load_int(&ipmforwarding) && ip_mrouter[ifp->if_rdomain]) { int error; if (m->m_flags & M_EXT) { if ((m = *mp = m_pullup(m, hlen)) == NULL) { ipstat_inc(ips_toosmall); goto bad; } ip = mtod(m, struct ip *); } /* * If we are acting as a multicast router, all * incoming multicast packets are passed to the * kernel-level multicast forwarding function. * The packet is returned (relatively) intact; if * ip_mforward() returns a non-zero value, the packet * must be discarded, else it may be accepted below. * * (The IP ident field is put in the same byte order * as expected when ip_mforward() is called from * ip_output().) */ KERNEL_LOCK(); error = ip_mforward(m, ifp, flags); KERNEL_UNLOCK(); if (error) { ipstat_inc(ips_cantforward); goto bad; } /* * The process-level routing daemon needs to receive * all multicast IGMP packets, whether or not this * host belongs to their destination groups. */ if (ip->ip_p == IPPROTO_IGMP) { nxt = ip_ours(mp, offp, nxt, af, ns); goto out; } ipstat_inc(ips_forward); } #endif /* * See if we belong to the destination multicast group on the * arrival interface. */ if (!in_hasmulti(&ip->ip_dst, ifp)) { ipstat_inc(ips_notmember); if (!IN_LOCAL_GROUP(ip->ip_dst.s_addr)) ipstat_inc(ips_cantforward); goto bad; } nxt = ip_ours(mp, offp, nxt, af, ns); goto out; } #if NCARP > 0 if (ip->ip_p == IPPROTO_ICMP && carp_lsdrop(ifp, m, AF_INET, &ip->ip_src.s_addr, &ip->ip_dst.s_addr, 1)) goto bad; #endif /* * Not for us; forward if possible and desirable. */ if (!ISSET(flags, IP_FORWARDING)) { ipstat_inc(ips_cantforward); goto bad; } #ifdef IPSEC if (ipsec_in_use) { int rv; rv = ipsec_forward_check(m, hlen, AF_INET); if (rv != 0) { ipstat_inc(ips_cantforward); goto bad; } /* * Fall through, forward packet. Outbound IPsec policy * checking will occur in ip_output(). */ } #endif /* IPSEC */ ip_forward(m, ifp, ro, flags); *mp = NULL; if (ro == &iproute) rtfree(ro->ro_rt); return IPPROTO_DONE; bad: nxt = IPPROTO_DONE; m_freemp(mp); out: if (ro == &iproute) rtfree(ro->ro_rt); return nxt; } int ip_fragcheck(struct mbuf **mp, int *offp) { struct ip *ip; struct ipq *fp; struct ipqent *ipqe; int hlen; uint16_t mff; ip = mtod(*mp, struct ip *); hlen = ip->ip_hl << 2; /* * If offset or more fragments are set, must reassemble. * Otherwise, nothing need be done. * (We could look in the reassembly queue to see * if the packet was previously fragmented, * but it's not worth the time; just let them time out.) */ if (ISSET(ip->ip_off, htons(IP_OFFMASK | IP_MF))) { if ((*mp)->m_flags & M_EXT) { /* XXX */ if ((*mp = m_pullup(*mp, hlen)) == NULL) { ipstat_inc(ips_toosmall); return IPPROTO_DONE; } ip = mtod(*mp, struct ip *); } /* * Adjust ip_len to not reflect header, * set ipqe_mff if more fragments are expected, * convert offset of this to bytes. */ ip->ip_len = htons(ntohs(ip->ip_len) - hlen); mff = ISSET(ip->ip_off, htons(IP_MF)); if (mff) { /* * Make sure that fragments have a data length * that's a non-zero multiple of 8 bytes. */ if (ntohs(ip->ip_len) == 0 || (ntohs(ip->ip_len) & 0x7) != 0) { ipstat_inc(ips_badfrags); m_freemp(mp); return IPPROTO_DONE; } } ip->ip_off = htons(ntohs(ip->ip_off) << 3); mtx_enter(&ipq_mutex); /* * Look for queue of fragments * of this datagram. */ LIST_FOREACH(fp, &ipq, ipq_q) { if (ip->ip_id == fp->ipq_id && ip->ip_src.s_addr == fp->ipq_src.s_addr && ip->ip_dst.s_addr == fp->ipq_dst.s_addr && ip->ip_p == fp->ipq_p) break; } /* * If datagram marked as having more fragments * or if this is not the first fragment, * attempt reassembly; if it succeeds, proceed. */ if (mff || ip->ip_off) { int ip_maxqueue_local = atomic_load_int(&ip_maxqueue); ipstat_inc(ips_fragments); if (ip_frags + 1 > ip_maxqueue_local) { ip_flush(ip_maxqueue_local); ipstat_inc(ips_rcvmemdrop); goto bad; } ipqe = pool_get(&ipqent_pool, PR_NOWAIT); if (ipqe == NULL) { ipstat_inc(ips_rcvmemdrop); goto bad; } ip_frags++; ipqe->ipqe_mff = mff; ipqe->ipqe_m = *mp; ipqe->ipqe_ip = ip; *mp = ip_reass(ipqe, fp); if (*mp == NULL) goto bad; ipstat_inc(ips_reassembled); ip = mtod(*mp, struct ip *); hlen = ip->ip_hl << 2; ip->ip_len = htons(ntohs(ip->ip_len) + hlen); } else { if (fp != NULL) ip_freef(fp); } mtx_leave(&ipq_mutex); } *offp = hlen; return ip->ip_p; bad: mtx_leave(&ipq_mutex); m_freemp(mp); return IPPROTO_DONE; } #ifndef INET6 #define IPSTAT_INC(name) ipstat_inc(ips_##name) #else #define IPSTAT_INC(name) (af == AF_INET ? \ ipstat_inc(ips_##name) : ip6stat_inc(ip6s_##name)) #endif int ip_deliver(struct mbuf **mp, int *offp, int nxt, int af, int shared, struct netstack *ns) { #ifdef INET6 int nest = 0; #endif /* * Tell launch routine the next header */ IPSTAT_INC(delivered); while (nxt != IPPROTO_DONE) { const struct protosw *psw; int naf; switch (af) { case AF_INET: psw = &inetsw[ip_protox[nxt]]; break; #ifdef INET6 case AF_INET6: psw = &inet6sw[ip6_protox[nxt]]; break; #endif } if (shared && !ISSET(psw->pr_flags, PR_MPINPUT)) { /* delivery not finished, decrement counter, queue */ switch (af) { case AF_INET: counters_dec(ipcounters, ips_delivered); return ip_ours_enqueue(mp, offp, nxt); #ifdef INET6 case AF_INET6: counters_dec(ip6counters, ip6s_delivered); return ip6_ours_enqueue(mp, offp, nxt); #endif } break; } #ifdef INET6 if (af == AF_INET6 && (++nest > atomic_load_int(&ip6_hdrnestlimit))) { ip6stat_inc(ip6s_toomanyhdr); goto bad; } #endif /* * protection against faulty packet - there should be * more sanity checks in header chain processing. */ if ((*mp)->m_pkthdr.len < *offp) { IPSTAT_INC(tooshort); goto bad; } #ifdef IPSEC if (ipsec_in_use) { if (ipsec_local_check(*mp, *offp, nxt, af) != 0) { IPSTAT_INC(cantforward); goto bad; } } /* Otherwise, just fall through and deliver the packet */ #endif switch (nxt) { case IPPROTO_IPV4: naf = AF_INET; ipstat_inc(ips_delivered); break; #ifdef INET6 case IPPROTO_IPV6: naf = AF_INET6; ip6stat_inc(ip6s_delivered); break; #endif default: naf = af; break; } nxt = (*psw->pr_input)(mp, offp, nxt, af, ns); af = naf; } return nxt; bad: m_freemp(mp); return IPPROTO_DONE; } #undef IPSTAT_INC int in_ouraddr(struct mbuf *m, struct ifnet *ifp, struct route *ro, int flags) { struct rtentry *rt; struct ip *ip; int match = 0; #if NPF > 0 switch (pf_ouraddr(m)) { case 0: return (0); case 1: return (1); default: /* pf does not know it */ break; } #endif ip = mtod(m, struct ip *); if (ip->ip_dst.s_addr == INADDR_BROADCAST || ip->ip_dst.s_addr == INADDR_ANY) { m->m_flags |= M_BCAST; return (1); } rt = route_mpath(ro, &ip->ip_dst, &ip->ip_src, m->m_pkthdr.ph_rtableid); if (rt != NULL) { if (ISSET(rt->rt_flags, RTF_LOCAL)) match = 1; /* * If directedbcast is enabled we only consider it local * if it is received on the interface with that address. */ if (ISSET(rt->rt_flags, RTF_BROADCAST) && (!ISSET(flags, IP_ALLOWBROADCAST) || rt->rt_ifidx == ifp->if_index)) { match = 1; /* Make sure M_BCAST is set */ m->m_flags |= M_BCAST; } } if (!match) { struct ifaddr *ifa; /* * No local address or broadcast address found, so check for * ancient classful broadcast addresses. * It must have been broadcast on the link layer, and for an * address on the interface it was received on. */ if (!ISSET(m->m_flags, M_BCAST) || !IN_CLASSFULBROADCAST(ip->ip_dst.s_addr, ip->ip_dst.s_addr)) return (0); if (ifp->if_rdomain != rtable_l2(m->m_pkthdr.ph_rtableid)) return (0); /* * The check in the loop assumes you only rx a packet on an UP * interface, and that M_BCAST will only be set on a BROADCAST * interface. */ NET_ASSERT_LOCKED(); TAILQ_FOREACH(ifa, &ifp->if_addrlist, ifa_list) { if (ifa->ifa_addr->sa_family != AF_INET) continue; if (IN_CLASSFULBROADCAST(ip->ip_dst.s_addr, ifatoia(ifa)->ia_addr.sin_addr.s_addr)) { match = 1; break; } } } else if (!ISSET(flags, IP_FORWARDING) && rt->rt_ifidx != ifp->if_index && !((ifp->if_flags & IFF_LOOPBACK) || (ifp->if_type == IFT_ENC) || (m->m_pkthdr.pf.flags & PF_TAG_TRANSLATE_LOCALHOST))) { /* received on wrong interface. */ #if NCARP > 0 struct ifnet *out_if; /* * Virtual IPs on carp interfaces need to be checked also * against the parent interface and other carp interfaces * sharing the same parent. */ out_if = if_get(rt->rt_ifidx); if (!(out_if && carp_strict_addr_chk(out_if, ifp))) { ipstat_inc(ips_wrongif); match = 2; } if_put(out_if); #else ipstat_inc(ips_wrongif); match = 2; #endif } return (match); } /* * Take incoming datagram fragment and try to * reassemble it into whole datagram. If a chain for * reassembly of this datagram already exists, then it * is given as fp; otherwise have to make a chain. */ struct mbuf * ip_reass(struct ipqent *ipqe, struct ipq *fp) { struct mbuf *m = ipqe->ipqe_m; struct ipqent *nq, *p, *q; struct ip *ip; struct mbuf *t; int hlen = ipqe->ipqe_ip->ip_hl << 2; int i, next; u_int8_t ecn, ecn0; MUTEX_ASSERT_LOCKED(&ipq_mutex); /* * Presence of header sizes in mbufs * would confuse code below. */ m->m_data += hlen; m->m_len -= hlen; /* * If first fragment to arrive, create a reassembly queue. */ if (fp == NULL) { fp = pool_get(&ipq_pool, PR_NOWAIT); if (fp == NULL) goto dropfrag; LIST_INSERT_HEAD(&ipq, fp, ipq_q); fp->ipq_ttl = IPFRAGTTL; fp->ipq_p = ipqe->ipqe_ip->ip_p; fp->ipq_id = ipqe->ipqe_ip->ip_id; LIST_INIT(&fp->ipq_fragq); fp->ipq_src = ipqe->ipqe_ip->ip_src; fp->ipq_dst = ipqe->ipqe_ip->ip_dst; p = NULL; goto insert; } /* * Handle ECN by comparing this segment with the first one; * if CE is set, do not lose CE. * drop if CE and not-ECT are mixed for the same packet. */ ecn = ipqe->ipqe_ip->ip_tos & IPTOS_ECN_MASK; ecn0 = LIST_FIRST(&fp->ipq_fragq)->ipqe_ip->ip_tos & IPTOS_ECN_MASK; if (ecn == IPTOS_ECN_CE) { if (ecn0 == IPTOS_ECN_NOTECT) goto dropfrag; if (ecn0 != IPTOS_ECN_CE) LIST_FIRST(&fp->ipq_fragq)->ipqe_ip->ip_tos |= IPTOS_ECN_CE; } if (ecn == IPTOS_ECN_NOTECT && ecn0 != IPTOS_ECN_NOTECT) goto dropfrag; /* * Find a segment which begins after this one does. */ for (p = NULL, q = LIST_FIRST(&fp->ipq_fragq); q != NULL; p = q, q = LIST_NEXT(q, ipqe_q)) if (ntohs(q->ipqe_ip->ip_off) > ntohs(ipqe->ipqe_ip->ip_off)) break; /* * If there is a preceding segment, it may provide some of * our data already. If so, drop the data from the incoming * segment. If it provides all of our data, drop us. */ if (p != NULL) { i = ntohs(p->ipqe_ip->ip_off) + ntohs(p->ipqe_ip->ip_len) - ntohs(ipqe->ipqe_ip->ip_off); if (i > 0) { if (i >= ntohs(ipqe->ipqe_ip->ip_len)) goto dropfrag; m_adj(ipqe->ipqe_m, i); ipqe->ipqe_ip->ip_off = htons(ntohs(ipqe->ipqe_ip->ip_off) + i); ipqe->ipqe_ip->ip_len = htons(ntohs(ipqe->ipqe_ip->ip_len) - i); } } /* * While we overlap succeeding segments trim them or, * if they are completely covered, dequeue them. */ for (; q != NULL && ntohs(ipqe->ipqe_ip->ip_off) + ntohs(ipqe->ipqe_ip->ip_len) > ntohs(q->ipqe_ip->ip_off); q = nq) { i = (ntohs(ipqe->ipqe_ip->ip_off) + ntohs(ipqe->ipqe_ip->ip_len)) - ntohs(q->ipqe_ip->ip_off); if (i < ntohs(q->ipqe_ip->ip_len)) { q->ipqe_ip->ip_len = htons(ntohs(q->ipqe_ip->ip_len) - i); q->ipqe_ip->ip_off = htons(ntohs(q->ipqe_ip->ip_off) + i); m_adj(q->ipqe_m, i); break; } nq = LIST_NEXT(q, ipqe_q); m_freem(q->ipqe_m); LIST_REMOVE(q, ipqe_q); pool_put(&ipqent_pool, q); ip_frags--; } insert: /* * Stick new segment in its place; * check for complete reassembly. */ if (p == NULL) { LIST_INSERT_HEAD(&fp->ipq_fragq, ipqe, ipqe_q); } else { LIST_INSERT_AFTER(p, ipqe, ipqe_q); } next = 0; for (p = NULL, q = LIST_FIRST(&fp->ipq_fragq); q != NULL; p = q, q = LIST_NEXT(q, ipqe_q)) { if (ntohs(q->ipqe_ip->ip_off) != next) return (0); next += ntohs(q->ipqe_ip->ip_len); } if (p->ipqe_mff) return (0); /* * Reassembly is complete. Check for a bogus message size and * concatenate fragments. */ q = LIST_FIRST(&fp->ipq_fragq); ip = q->ipqe_ip; if ((next + (ip->ip_hl << 2)) > IP_MAXPACKET) { ipstat_inc(ips_toolong); ip_freef(fp); return (0); } m = q->ipqe_m; t = m->m_next; m->m_next = 0; m_cat(m, t); nq = LIST_NEXT(q, ipqe_q); pool_put(&ipqent_pool, q); ip_frags--; for (q = nq; q != NULL; q = nq) { t = q->ipqe_m; nq = LIST_NEXT(q, ipqe_q); pool_put(&ipqent_pool, q); ip_frags--; m_removehdr(t); m_cat(m, t); } /* * Create header for new ip packet by * modifying header of first packet; * dequeue and discard fragment reassembly header. * Make header visible. */ ip->ip_len = htons(next); ip->ip_src = fp->ipq_src; ip->ip_dst = fp->ipq_dst; LIST_REMOVE(fp, ipq_q); pool_put(&ipq_pool, fp); m->m_len += (ip->ip_hl << 2); m->m_data -= (ip->ip_hl << 2); m_calchdrlen(m); return (m); dropfrag: ipstat_inc(ips_fragdropped); m_freem(m); pool_put(&ipqent_pool, ipqe); ip_frags--; return (NULL); } /* * Free a fragment reassembly header and all * associated datagrams. */ void ip_freef(struct ipq *fp) { struct ipqent *q; MUTEX_ASSERT_LOCKED(&ipq_mutex); while ((q = LIST_FIRST(&fp->ipq_fragq)) != NULL) { LIST_REMOVE(q, ipqe_q); m_freem(q->ipqe_m); pool_put(&ipqent_pool, q); ip_frags--; } LIST_REMOVE(fp, ipq_q); pool_put(&ipq_pool, fp); } /* * IP timer processing; * if a timer expires on a reassembly queue, discard it. */ void ip_slowtimo(void) { struct ipq *fp, *nfp; mtx_enter(&ipq_mutex); LIST_FOREACH_SAFE(fp, &ipq, ipq_q, nfp) { if (--fp->ipq_ttl == 0) { ipstat_inc(ips_fragtimeout); ip_freef(fp); } } mtx_leave(&ipq_mutex); } /* * Flush a bunch of datagram fragments, till we are down to 75%. */ void ip_flush(int maxqueue) { int max = 50; MUTEX_ASSERT_LOCKED(&ipq_mutex); while (!LIST_EMPTY(&ipq) && ip_frags > maxqueue * 3 / 4 && --max) { ipstat_inc(ips_fragdropped); ip_freef(LIST_FIRST(&ipq)); } } /* * Do option processing on a datagram, * possibly discarding it if bad options are encountered, * or forwarding it if source-routed. * Returns 1 if packet has been forwarded/freed, * 0 if the packet should be processed further. */ int ip_dooptions(struct mbuf *m, struct ifnet *ifp, int flags) { struct ip *ip = mtod(m, struct ip *); unsigned int rtableid = m->m_pkthdr.ph_rtableid; struct rtentry *rt; struct sockaddr_in ipaddr; u_char *cp; struct ip_timestamp ipt; struct in_ifaddr *ia; int opt, optlen, cnt, off, code, type = ICMP_PARAMPROB, forward = 0; struct in_addr sin, dst; u_int32_t ntime; dst = ip->ip_dst; cp = (u_char *)(ip + 1); cnt = (ip->ip_hl << 2) - sizeof (struct ip); KERNEL_LOCK(); for (; cnt > 0; cnt -= optlen, cp += optlen) { opt = cp[IPOPT_OPTVAL]; if (opt == IPOPT_EOL) break; if (opt == IPOPT_NOP) optlen = 1; else { if (cnt < IPOPT_OLEN + sizeof(*cp)) { code = &cp[IPOPT_OLEN] - (u_char *)ip; goto bad; } optlen = cp[IPOPT_OLEN]; if (optlen < IPOPT_OLEN + sizeof(*cp) || optlen > cnt) { code = &cp[IPOPT_OLEN] - (u_char *)ip; goto bad; } } switch (opt) { default: break; /* * Source routing with record. * Find interface with current destination address. * If none on this machine then drop if strictly routed, * or do nothing if loosely routed. * Record interface address and bring up next address * component. If strictly routed make sure next * address is on directly accessible net. */ case IPOPT_LSRR: case IPOPT_SSRR: if (atomic_load_int(&ip_dosourceroute) == 0) { type = ICMP_UNREACH; code = ICMP_UNREACH_SRCFAIL; goto bad; } if (optlen < IPOPT_OFFSET + sizeof(*cp)) { code = &cp[IPOPT_OLEN] - (u_char *)ip; goto bad; } if ((off = cp[IPOPT_OFFSET]) < IPOPT_MINOFF) { code = &cp[IPOPT_OFFSET] - (u_char *)ip; goto bad; } memset(&ipaddr, 0, sizeof(ipaddr)); ipaddr.sin_family = AF_INET; ipaddr.sin_len = sizeof(ipaddr); ipaddr.sin_addr = ip->ip_dst; ia = ifatoia(ifa_ifwithaddr(sintosa(&ipaddr), m->m_pkthdr.ph_rtableid)); if (ia == NULL) { if (opt == IPOPT_SSRR) { type = ICMP_UNREACH; code = ICMP_UNREACH_SRCFAIL; goto bad; } /* * Loose routing, and not at next destination * yet; nothing to do except forward. */ break; } off--; /* 0 origin */ if ((off + sizeof(struct in_addr)) > optlen) { /* * End of source route. Should be for us. */ save_rte(m, cp, ip->ip_src); break; } /* * locate outgoing interface */ memset(&ipaddr, 0, sizeof(ipaddr)); ipaddr.sin_family = AF_INET; ipaddr.sin_len = sizeof(ipaddr); memcpy(&ipaddr.sin_addr, cp + off, sizeof(ipaddr.sin_addr)); /* keep packet in the virtual instance */ rt = rtalloc(sintosa(&ipaddr), RT_RESOLVE, rtableid); if (!rtisvalid(rt) || ((opt == IPOPT_SSRR) && ISSET(rt->rt_flags, RTF_GATEWAY))) { type = ICMP_UNREACH; code = ICMP_UNREACH_SRCFAIL; rtfree(rt); goto bad; } ia = ifatoia(rt->rt_ifa); memcpy(cp + off, &ia->ia_addr.sin_addr, sizeof(struct in_addr)); rtfree(rt); cp[IPOPT_OFFSET] += sizeof(struct in_addr); ip->ip_dst = ipaddr.sin_addr; /* * Let ip_intr's mcast routing check handle mcast pkts */ forward = !IN_MULTICAST(ip->ip_dst.s_addr); break; case IPOPT_RR: if (optlen < IPOPT_OFFSET + sizeof(*cp)) { code = &cp[IPOPT_OLEN] - (u_char *)ip; goto bad; } if ((off = cp[IPOPT_OFFSET]) < IPOPT_MINOFF) { code = &cp[IPOPT_OFFSET] - (u_char *)ip; goto bad; } /* * If no space remains, ignore. */ off--; /* 0 origin */ if ((off + sizeof(struct in_addr)) > optlen) break; memset(&ipaddr, 0, sizeof(ipaddr)); ipaddr.sin_family = AF_INET; ipaddr.sin_len = sizeof(ipaddr); ipaddr.sin_addr = ip->ip_dst; /* * locate outgoing interface; if we're the destination, * use the incoming interface (should be same). * Again keep the packet inside the virtual instance. */ rt = rtalloc(sintosa(&ipaddr), RT_RESOLVE, rtableid); if (!rtisvalid(rt)) { type = ICMP_UNREACH; code = ICMP_UNREACH_HOST; rtfree(rt); goto bad; } ia = ifatoia(rt->rt_ifa); memcpy(cp + off, &ia->ia_addr.sin_addr, sizeof(struct in_addr)); rtfree(rt); cp[IPOPT_OFFSET] += sizeof(struct in_addr); break; case IPOPT_TS: code = cp - (u_char *)ip; if (optlen < sizeof(struct ip_timestamp)) goto bad; memcpy(&ipt, cp, sizeof(struct ip_timestamp)); if (ipt.ipt_ptr < 5 || ipt.ipt_len < 5) goto bad; if (ipt.ipt_ptr - 1 + sizeof(u_int32_t) > ipt.ipt_len) { if (++ipt.ipt_oflw == 0) goto bad; break; } memcpy(&sin, cp + ipt.ipt_ptr - 1, sizeof sin); switch (ipt.ipt_flg) { case IPOPT_TS_TSONLY: break; case IPOPT_TS_TSANDADDR: if (ipt.ipt_ptr - 1 + sizeof(u_int32_t) + sizeof(struct in_addr) > ipt.ipt_len) goto bad; memset(&ipaddr, 0, sizeof(ipaddr)); ipaddr.sin_family = AF_INET; ipaddr.sin_len = sizeof(ipaddr); ipaddr.sin_addr = dst; ia = ifatoia(ifaof_ifpforaddr(sintosa(&ipaddr), ifp)); if (ia == NULL) continue; memcpy(&sin, &ia->ia_addr.sin_addr, sizeof(struct in_addr)); ipt.ipt_ptr += sizeof(struct in_addr); break; case IPOPT_TS_PRESPEC: if (ipt.ipt_ptr - 1 + sizeof(u_int32_t) + sizeof(struct in_addr) > ipt.ipt_len) goto bad; memset(&ipaddr, 0, sizeof(ipaddr)); ipaddr.sin_family = AF_INET; ipaddr.sin_len = sizeof(ipaddr); ipaddr.sin_addr = sin; if (ifa_ifwithaddr(sintosa(&ipaddr), m->m_pkthdr.ph_rtableid) == NULL) continue; ipt.ipt_ptr += sizeof(struct in_addr); break; default: /* XXX can't take &ipt->ipt_flg */ code = (u_char *)&ipt.ipt_ptr - (u_char *)ip + 1; goto bad; } ntime = iptime(); memcpy(cp + ipt.ipt_ptr - 1, &ntime, sizeof(u_int32_t)); ipt.ipt_ptr += sizeof(u_int32_t); } } KERNEL_UNLOCK(); if (forward && ISSET(flags, IP_FORWARDING)) { ip_forward(m, ifp, NULL, flags | IP_REDIRECT); return (1); } return (0); bad: KERNEL_UNLOCK(); icmp_error(m, type, code, 0, 0); ipstat_inc(ips_badoptions); return (1); } /* * Save incoming source route for use in replies, * to be picked up later by ip_srcroute if the receiver is interested. */ void save_rte(struct mbuf *m, u_char *option, struct in_addr dst) { struct ip_srcrt *isr; struct m_tag *mtag; unsigned olen; olen = option[IPOPT_OLEN]; if (olen > sizeof(isr->isr_hdr) + sizeof(isr->isr_routes)) return; mtag = m_tag_get(PACKET_TAG_SRCROUTE, sizeof(*isr), M_NOWAIT); if (mtag == NULL) { ipstat_inc(ips_idropped); return; } isr = (struct ip_srcrt *)(mtag + 1); memcpy(isr->isr_hdr, option, olen); isr->isr_nhops = (olen - IPOPT_OFFSET - 1) / sizeof(struct in_addr); isr->isr_dst = dst; m_tag_prepend(m, mtag); } /* * Retrieve incoming source route for use in replies, * in the same form used by setsockopt. * The first hop is placed before the options, will be removed later. */ struct mbuf * ip_srcroute(struct mbuf *m0) { struct in_addr *p, *q; struct mbuf *m; struct ip_srcrt *isr; struct m_tag *mtag; if (atomic_load_int(&ip_dosourceroute) == 0) return (NULL); mtag = m_tag_find(m0, PACKET_TAG_SRCROUTE, NULL); if (mtag == NULL) return (NULL); isr = (struct ip_srcrt *)(mtag + 1); if (isr->isr_nhops == 0) return (NULL); m = m_get(M_DONTWAIT, MT_SOOPTS); if (m == NULL) { ipstat_inc(ips_idropped); return (NULL); } #define OPTSIZ (sizeof(isr->isr_nop) + sizeof(isr->isr_hdr)) /* length is (nhops+1)*sizeof(addr) + sizeof(nop + header) */ m->m_len = (isr->isr_nhops + 1) * sizeof(struct in_addr) + OPTSIZ; /* * First save first hop for return route */ p = &(isr->isr_routes[isr->isr_nhops - 1]); *(mtod(m, struct in_addr *)) = *p--; /* * Copy option fields and padding (nop) to mbuf. */ isr->isr_nop = IPOPT_NOP; isr->isr_hdr[IPOPT_OFFSET] = IPOPT_MINOFF; memcpy(mtod(m, caddr_t) + sizeof(struct in_addr), &isr->isr_nop, OPTSIZ); q = (struct in_addr *)(mtod(m, caddr_t) + sizeof(struct in_addr) + OPTSIZ); #undef OPTSIZ /* * Record return path as an IP source route, * reversing the path (pointers are now aligned). */ while (p >= isr->isr_routes) { *q++ = *p--; } /* * Last hop goes to final destination. */ *q = isr->isr_dst; m_tag_delete(m0, (struct m_tag *)isr); return (m); } /* * Strip out IP options, at higher level protocol in the kernel. */ void ip_stripoptions(struct mbuf *m) { int i; struct ip *ip = mtod(m, struct ip *); caddr_t opts; int olen; olen = (ip->ip_hl<<2) - sizeof (struct ip); opts = (caddr_t)(ip + 1); i = m->m_len - (sizeof (struct ip) + olen); memmove(opts, opts + olen, i); m->m_len -= olen; if (m->m_flags & M_PKTHDR) m->m_pkthdr.len -= olen; ip->ip_hl = sizeof(struct ip) >> 2; ip->ip_len = htons(ntohs(ip->ip_len) - olen); } const u_char inetctlerrmap[PRC_NCMDS] = { 0, 0, 0, 0, 0, EMSGSIZE, EHOSTDOWN, EHOSTUNREACH, EHOSTUNREACH, EHOSTUNREACH, ECONNREFUSED, ECONNREFUSED, EMSGSIZE, EHOSTUNREACH, 0, 0, 0, 0, 0, 0, ENOPROTOOPT }; /* * Forward a packet. If some error occurs return the sender * an icmp packet. Note we can't always generate a meaningful * icmp message because icmp doesn't have a large enough repertoire * of codes and types. * * If not forwarding, just drop the packet. This could be confusing * if ip_forwarding was zero but some routing protocol was advancing * us as a gateway to somewhere. However, we must let the routing * protocol deal with that. * * The srcrt parameter indicates whether the packet is being forwarded * via a source route. */ void ip_forward(struct mbuf *m, struct ifnet *ifp, struct route *ro, int flags) { struct ip *ip = mtod(m, struct ip *); struct route iproute; struct rtentry *rt; u_int rtableid = m->m_pkthdr.ph_rtableid; u_int8_t loopcnt = m->m_pkthdr.ph_loopcnt; u_int icmp_len; char icmp_buf[68]; CTASSERT(sizeof(icmp_buf) <= MHLEN); u_short mflags, pfflags; struct mbuf *mcopy; int error = 0, type = 0, code = 0, destmtu = 0; u_int32_t dest; dest = 0; if (m->m_flags & (M_BCAST|M_MCAST) || in_canforward(ip->ip_dst) == 0) { ipstat_inc(ips_cantforward); m_freem(m); goto done; } if (ip->ip_ttl <= IPTTLDEC) { icmp_error(m, ICMP_TIMXCEED, ICMP_TIMXCEED_INTRANS, dest, 0); goto done; } if (ro == NULL) { ro = &iproute; ro->ro_rt = NULL; } rt = route_mpath(ro, &ip->ip_dst, &ip->ip_src, rtableid); if (rt == NULL) { ipstat_inc(ips_noroute); icmp_error(m, ICMP_UNREACH, ICMP_UNREACH_HOST, dest, 0); goto done; } /* * Save at most 68 bytes of the packet in case we need to generate * an ICMP message to the src. The data is saved on the stack. * A new mbuf is only allocated when ICMP is actually created. */ icmp_len = min(sizeof(icmp_buf), ntohs(ip->ip_len)); mflags = m->m_flags; pfflags = m->m_pkthdr.pf.flags; m_copydata(m, 0, icmp_len, icmp_buf); ip->ip_ttl -= IPTTLDEC; /* * If forwarding packet using same interface that it came in on, * perhaps should send a redirect to sender to shortcut a hop. * Only send redirect if source is sending directly to us, * and if packet was not source routed (or has any options). * Also, don't send redirect if forwarding using a default route * or a route modified by a redirect. * Don't send redirect if we advertise destination's arp address * as ours (proxy arp). */ if (rt->rt_ifidx == ifp->if_index && !ISSET(rt->rt_flags, RTF_DYNAMIC|RTF_MODIFIED) && satosin(rt_key(rt))->sin_addr.s_addr != INADDR_ANY && !ISSET(flags, IP_REDIRECT) && atomic_load_int(&ip_sendredirects) && !arpproxy(satosin(rt_key(rt))->sin_addr, rtableid)) { if ((ip->ip_src.s_addr & ifatoia(rt->rt_ifa)->ia_netmask) == ifatoia(rt->rt_ifa)->ia_net) { if (rt->rt_flags & RTF_GATEWAY) dest = satosin(rt->rt_gateway)->sin_addr.s_addr; else dest = ip->ip_dst.s_addr; /* Router requirements says to only send host redirects */ type = ICMP_REDIRECT; code = ICMP_REDIRECT_HOST; } } error = ip_output(m, NULL, ro, flags | IP_FORWARDING, NULL, NULL, 0); rt = ro->ro_rt; if (error) ipstat_inc(ips_cantforward); else { ipstat_inc(ips_forward); if (type) ipstat_inc(ips_redirectsent); else goto done; } switch (error) { case 0: /* forwarded, but need redirect */ /* type, code set above */ break; case EMSGSIZE: type = ICMP_UNREACH; code = ICMP_UNREACH_NEEDFRAG; if (rt != NULL) { u_int rtmtu; rtmtu = atomic_load_int(&rt->rt_mtu); if (rtmtu != 0) { destmtu = rtmtu; } else { struct ifnet *destifp; destifp = if_get(rt->rt_ifidx); if (destifp != NULL) destmtu = destifp->if_mtu; if_put(destifp); } } ipstat_inc(ips_cantfrag); if (destmtu == 0) goto done; break; case EACCES: /* * pf(4) blocked the packet. There is no need to send an ICMP * packet back since pf(4) takes care of it. */ goto done; case ENOBUFS: /* * a router should not generate ICMP_SOURCEQUENCH as * required in RFC1812 Requirements for IP Version 4 Routers. * source quench could be a big problem under DoS attacks, * or the underlying interface is rate-limited. */ goto done; case ENETUNREACH: /* shouldn't happen, checked above */ case EHOSTUNREACH: case ENETDOWN: case EHOSTDOWN: default: type = ICMP_UNREACH; code = ICMP_UNREACH_HOST; break; } mcopy = m_gethdr(M_DONTWAIT, MT_DATA); if (mcopy == NULL) goto done; mcopy->m_len = mcopy->m_pkthdr.len = icmp_len; mcopy->m_flags |= (mflags & M_COPYFLAGS); mcopy->m_pkthdr.ph_rtableid = rtableid; mcopy->m_pkthdr.ph_ifidx = ifp->if_index; mcopy->m_pkthdr.ph_loopcnt = loopcnt; mcopy->m_pkthdr.pf.flags |= (pfflags & PF_TAG_GENERATED); memcpy(mcopy->m_data, icmp_buf, icmp_len); icmp_error(mcopy, type, code, dest, destmtu); done: if (ro == &iproute) rtfree(ro->ro_rt); } #ifndef SMALL_KERNEL int ip_sysctl(int *name, u_int namelen, void *oldp, size_t *oldlenp, void *newp, size_t newlen) { int oldval, newval, error; /* Almost all sysctl names at this level are terminal. */ if (namelen != 1 && name[0] != IPCTL_IFQUEUE && name[0] != IPCTL_ARPQUEUE) return (ENOTDIR); switch (name[0]) { case IPCTL_SOURCEROUTE: return (sysctl_securelevel_int(oldp, oldlenp, newp, newlen, &ip_dosourceroute)); case IPCTL_MTUDISC: oldval = newval = atomic_load_int(&ip_mtudisc); error = sysctl_int_bounded(oldp, oldlenp, newp, newlen, &newval, 0, 1); if (error == 0 && oldval != newval && oldval == atomic_cas_uint(&ip_mtudisc, oldval, newval) && newval == 0) { NET_LOCK(); rt_timer_queue_flush(&ip_mtudisc_timeout_q); NET_UNLOCK(); } return (error); case IPCTL_MTUDISCTIMEOUT: oldval = newval = atomic_load_int(&ip_mtudisc_timeout); error = sysctl_int_bounded(oldp, oldlenp, newp, newlen, &newval, 0, INT_MAX); if (error == 0 && oldval != newval) { rw_enter_write(&sysctl_lock); atomic_store_int(&ip_mtudisc_timeout, newval); rt_timer_queue_change(&ip_mtudisc_timeout_q, newval); rw_exit_write(&sysctl_lock); } return (error); #ifdef IPSEC case IPCTL_ENCDEBUG: case IPCTL_IPSEC_STATS: case IPCTL_IPSEC_EXPIRE_ACQUIRE: case IPCTL_IPSEC_EMBRYONIC_SA_TIMEOUT: case IPCTL_IPSEC_REQUIRE_PFS: case IPCTL_IPSEC_SOFT_ALLOCATIONS: case IPCTL_IPSEC_ALLOCATIONS: case IPCTL_IPSEC_SOFT_BYTES: case IPCTL_IPSEC_BYTES: case IPCTL_IPSEC_TIMEOUT: case IPCTL_IPSEC_SOFT_TIMEOUT: case IPCTL_IPSEC_SOFT_FIRSTUSE: case IPCTL_IPSEC_FIRSTUSE: case IPCTL_IPSEC_ENC_ALGORITHM: case IPCTL_IPSEC_AUTH_ALGORITHM: case IPCTL_IPSEC_IPCOMP_ALGORITHM: return (ipsec_sysctl(name, namelen, oldp, oldlenp, newp, newlen)); #endif case IPCTL_IFQUEUE: return (sysctl_niq(name + 1, namelen - 1, oldp, oldlenp, newp, newlen, &ipintrq)); case IPCTL_ARPQUEUE: return (sysctl_niq(name + 1, namelen - 1, oldp, oldlenp, newp, newlen, &arpinq)); case IPCTL_ARPQUEUED: return (sysctl_rdint(oldp, oldlenp, newp, atomic_load_int(&la_hold_total))); case IPCTL_STATS: return (ip_sysctl_ipstat(oldp, oldlenp, newp)); #ifdef MROUTING case IPCTL_MRTSTATS: return (mrt_sysctl_mrtstat(oldp, oldlenp, newp)); case IPCTL_MRTMFC: if (newp) return (EPERM); return (mrt_sysctl_mfc(oldp, oldlenp)); case IPCTL_MRTVIF: if (newp) return (EPERM); return (mrt_sysctl_vif(oldp, oldlenp)); #else case IPCTL_MRTPROTO: case IPCTL_MRTSTATS: case IPCTL_MRTMFC: case IPCTL_MRTVIF: return (EOPNOTSUPP); #endif case IPCTL_MULTIPATH: oldval = newval = atomic_load_int(&ipmultipath); error = sysctl_int_bounded(oldp, oldlenp, newp, newlen, &newval, 0, 1); if (error == 0 && oldval != newval) { atomic_store_int(&ipmultipath, newval); membar_producer(); atomic_inc_long(&rtgeneration); } return (error); default: return (sysctl_bounded_arr(ipctl_vars, nitems(ipctl_vars), name, namelen, oldp, oldlenp, newp, newlen)); } /* NOTREACHED */ } int ip_sysctl_ipstat(void *oldp, size_t *oldlenp, void *newp) { uint64_t counters[ips_ncounters]; struct ipstat ipstat; u_long *words = (u_long *)&ipstat; int i; CTASSERT(sizeof(ipstat) == (nitems(counters) * sizeof(u_long))); memset(&ipstat, 0, sizeof ipstat); counters_read(ipcounters, counters, nitems(counters), NULL); for (i = 0; i < nitems(counters); i++) words[i] = (u_long)counters[i]; return (sysctl_rdstruct(oldp, oldlenp, newp, &ipstat, sizeof(ipstat))); } #endif /* SMALL_KERNEL */ void ip_savecontrol(struct inpcb *inp, struct mbuf **mp, struct ip *ip, struct mbuf *m) { if (inp->inp_socket->so_options & SO_TIMESTAMP) { struct timeval tv; m_microtime(m, &tv); *mp = sbcreatecontrol((caddr_t) &tv, sizeof(tv), SCM_TIMESTAMP, SOL_SOCKET); if (*mp) mp = &(*mp)->m_next; } if (inp->inp_flags & INP_RECVDSTADDR) { *mp = sbcreatecontrol((caddr_t) &ip->ip_dst, sizeof(struct in_addr), IP_RECVDSTADDR, IPPROTO_IP); if (*mp) mp = &(*mp)->m_next; } #ifdef notyet /* this code is broken and will probably never be fixed. */ /* options were tossed already */ if (inp->inp_flags & INP_RECVOPTS) { *mp = sbcreatecontrol((caddr_t) opts_deleted_above, sizeof(struct in_addr), IP_RECVOPTS, IPPROTO_IP); if (*mp) mp = &(*mp)->m_next; } /* ip_srcroute doesn't do what we want here, need to fix */ if (inp->inp_flags & INP_RECVRETOPTS) { *mp = sbcreatecontrol((caddr_t) ip_srcroute(m), sizeof(struct in_addr), IP_RECVRETOPTS, IPPROTO_IP); if (*mp) mp = &(*mp)->m_next; } #endif if (inp->inp_flags & INP_RECVIF) { struct sockaddr_dl sdl; struct ifnet *ifp; ifp = if_get(m->m_pkthdr.ph_ifidx); if (ifp == NULL || ifp->if_sadl == NULL) { memset(&sdl, 0, sizeof(sdl)); sdl.sdl_len = offsetof(struct sockaddr_dl, sdl_data[0]); sdl.sdl_family = AF_LINK; sdl.sdl_index = ifp != NULL ? ifp->if_index : 0; sdl.sdl_nlen = sdl.sdl_alen = sdl.sdl_slen = 0; *mp = sbcreatecontrol((caddr_t) &sdl, sdl.sdl_len, IP_RECVIF, IPPROTO_IP); } else { *mp = sbcreatecontrol((caddr_t) ifp->if_sadl, ifp->if_sadl->sdl_len, IP_RECVIF, IPPROTO_IP); } if (*mp) mp = &(*mp)->m_next; if_put(ifp); } if (inp->inp_flags & INP_RECVTTL) { *mp = sbcreatecontrol((caddr_t) &ip->ip_ttl, sizeof(u_int8_t), IP_RECVTTL, IPPROTO_IP); if (*mp) mp = &(*mp)->m_next; } if (inp->inp_flags & INP_RECVRTABLE) { u_int rtableid = inp->inp_rtableid; #if NPF > 0 if (m && m->m_pkthdr.pf.flags & PF_TAG_DIVERTED) { struct pf_divert *divert; divert = pf_find_divert(m); KASSERT(divert != NULL); rtableid = divert->rdomain; } #endif *mp = sbcreatecontrol((caddr_t) &rtableid, sizeof(u_int), IP_RECVRTABLE, IPPROTO_IP); if (*mp) mp = &(*mp)->m_next; } } void ip_send_do_dispatch(void *xmq, int flags) { struct mbuf_queue *mq = xmq; struct mbuf *m; struct mbuf_list ml; struct m_tag *mtag; mq_delist(mq, &ml); if (ml_empty(&ml)) return; NET_LOCK_SHARED(); while ((m = ml_dequeue(&ml)) != NULL) { u_int32_t ipsecflowinfo = 0; if ((mtag = m_tag_find(m, PACKET_TAG_IPSEC_FLOWINFO, NULL)) != NULL) { ipsecflowinfo = *(u_int32_t *)(mtag + 1); m_tag_delete(m, mtag); } ip_output(m, NULL, NULL, flags, NULL, NULL, ipsecflowinfo); } NET_UNLOCK_SHARED(); } void ip_sendraw_dispatch(void *xmq) { ip_send_do_dispatch(xmq, IP_RAWOUTPUT); } void ip_send_dispatch(void *xmq) { ip_send_do_dispatch(xmq, 0); } void ip_send(struct mbuf *m) { mq_enqueue(&ipsend_mq, m); task_add(net_tq(0), &ipsend_task); } void ip_send_raw(struct mbuf *m) { mq_enqueue(&ipsendraw_mq, m); task_add(net_tq(0), &ipsendraw_task); }