diff --git a/sys/netinet/ip_input.c b/sys/netinet/ip_input.c index e17d6fccb202..059f26869e0e 100644 --- a/sys/netinet/ip_input.c +++ b/sys/netinet/ip_input.c @@ -1,1381 +1,1384 @@ /*- * SPDX-License-Identifier: BSD-3-Clause * * 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 __FBSDID("$FreeBSD$"); #include "opt_bootp.h" #include "opt_ipstealth.h" #include "opt_ipsec.h" #include "opt_route.h" #include "opt_rss.h" #include "opt_sctp.h" #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #ifdef SCTP #include #endif #include #include #include #ifdef CTASSERT CTASSERT(sizeof(struct ip) == 20); #endif /* IP reassembly functions are defined in ip_reass.c. */ extern void ipreass_init(void); +extern void ipreass_vnet_init(void); #ifdef VIMAGE extern void ipreass_destroy(void); #endif VNET_DEFINE(int, rsvp_on); VNET_DEFINE(int, ipforwarding); SYSCTL_INT(_net_inet_ip, IPCTL_FORWARDING, forwarding, CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(ipforwarding), 0, "Enable IP forwarding between interfaces"); /* * Respond with an ICMP host redirect when we forward a packet out of * the same interface on which it was received. See RFC 792. */ VNET_DEFINE(int, ipsendredirects) = 1; SYSCTL_INT(_net_inet_ip, IPCTL_SENDREDIRECTS, redirect, CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(ipsendredirects), 0, "Enable sending IP redirects"); VNET_DEFINE_STATIC(bool, ip_strong_es) = false; #define V_ip_strong_es VNET(ip_strong_es) SYSCTL_BOOL(_net_inet_ip, OID_AUTO, rfc1122_strong_es, CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(ip_strong_es), false, "Packet's IP destination address must match address on arrival interface"); VNET_DEFINE_STATIC(bool, ip_sav) = true; #define V_ip_sav VNET(ip_sav) SYSCTL_BOOL(_net_inet_ip, OID_AUTO, source_address_validation, CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(ip_sav), true, "Drop incoming packets with source address that is a local address"); VNET_DEFINE(pfil_head_t, inet_pfil_head); /* Packet filter hooks */ static struct netisr_handler ip_nh = { .nh_name = "ip", .nh_handler = ip_input, .nh_proto = NETISR_IP, #ifdef RSS .nh_m2cpuid = rss_soft_m2cpuid_v4, .nh_policy = NETISR_POLICY_CPU, .nh_dispatch = NETISR_DISPATCH_HYBRID, #else .nh_policy = NETISR_POLICY_FLOW, #endif }; #ifdef RSS /* * Directly dispatched frames are currently assumed * to have a flowid already calculated. * * It should likely have something that assert it * actually has valid flow details. */ static struct netisr_handler ip_direct_nh = { .nh_name = "ip_direct", .nh_handler = ip_direct_input, .nh_proto = NETISR_IP_DIRECT, .nh_m2cpuid = rss_soft_m2cpuid_v4, .nh_policy = NETISR_POLICY_CPU, .nh_dispatch = NETISR_DISPATCH_HYBRID, }; #endif ipproto_input_t *ip_protox[IPPROTO_MAX] = { [0 ... IPPROTO_MAX - 1] = rip_input }; ipproto_ctlinput_t *ip_ctlprotox[IPPROTO_MAX] = { [0 ... IPPROTO_MAX - 1] = rip_ctlinput }; VNET_DEFINE(struct in_ifaddrhead, in_ifaddrhead); /* first inet address */ VNET_DEFINE(struct in_ifaddrhashhead *, in_ifaddrhashtbl); /* inet addr hash table */ VNET_DEFINE(u_long, in_ifaddrhmask); /* mask for hash table */ /* Make sure it is safe to use hashinit(9) on CK_LIST. */ CTASSERT(sizeof(struct in_ifaddrhashhead) == sizeof(LIST_HEAD(, in_addr))); #ifdef IPCTL_DEFMTU SYSCTL_INT(_net_inet_ip, IPCTL_DEFMTU, mtu, CTLFLAG_RW, &ip_mtu, 0, "Default MTU"); #endif #ifdef IPSTEALTH VNET_DEFINE(int, ipstealth); SYSCTL_INT(_net_inet_ip, OID_AUTO, stealth, CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(ipstealth), 0, "IP stealth mode, no TTL decrementation on forwarding"); #endif /* * IP statistics are stored in the "array" of counter(9)s. */ VNET_PCPUSTAT_DEFINE(struct ipstat, ipstat); VNET_PCPUSTAT_SYSINIT(ipstat); SYSCTL_VNET_PCPUSTAT(_net_inet_ip, IPCTL_STATS, stats, struct ipstat, ipstat, "IP statistics (struct ipstat, netinet/ip_var.h)"); #ifdef VIMAGE VNET_PCPUSTAT_SYSUNINIT(ipstat); #endif /* VIMAGE */ /* * Kernel module interface for updating ipstat. The argument is an index * into ipstat treated as an array. */ void kmod_ipstat_inc(int statnum) { counter_u64_add(VNET(ipstat)[statnum], 1); } void kmod_ipstat_dec(int statnum) { counter_u64_add(VNET(ipstat)[statnum], -1); } static int sysctl_netinet_intr_queue_maxlen(SYSCTL_HANDLER_ARGS) { int error, qlimit; netisr_getqlimit(&ip_nh, &qlimit); error = sysctl_handle_int(oidp, &qlimit, 0, req); if (error || !req->newptr) return (error); if (qlimit < 1) return (EINVAL); return (netisr_setqlimit(&ip_nh, qlimit)); } SYSCTL_PROC(_net_inet_ip, IPCTL_INTRQMAXLEN, intr_queue_maxlen, CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_MPSAFE, 0, 0, sysctl_netinet_intr_queue_maxlen, "I", "Maximum size of the IP input queue"); static int sysctl_netinet_intr_queue_drops(SYSCTL_HANDLER_ARGS) { u_int64_t qdrops_long; int error, qdrops; netisr_getqdrops(&ip_nh, &qdrops_long); qdrops = qdrops_long; error = sysctl_handle_int(oidp, &qdrops, 0, req); if (error || !req->newptr) return (error); if (qdrops != 0) return (EINVAL); netisr_clearqdrops(&ip_nh); return (0); } SYSCTL_PROC(_net_inet_ip, IPCTL_INTRQDROPS, intr_queue_drops, CTLTYPE_INT | CTLFLAG_RD | CTLFLAG_MPSAFE, 0, 0, sysctl_netinet_intr_queue_drops, "I", "Number of packets dropped from the IP input queue"); #ifdef RSS static int sysctl_netinet_intr_direct_queue_maxlen(SYSCTL_HANDLER_ARGS) { int error, qlimit; netisr_getqlimit(&ip_direct_nh, &qlimit); error = sysctl_handle_int(oidp, &qlimit, 0, req); if (error || !req->newptr) return (error); if (qlimit < 1) return (EINVAL); return (netisr_setqlimit(&ip_direct_nh, qlimit)); } SYSCTL_PROC(_net_inet_ip, IPCTL_INTRDQMAXLEN, intr_direct_queue_maxlen, CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_MPSAFE, 0, 0, sysctl_netinet_intr_direct_queue_maxlen, "I", "Maximum size of the IP direct input queue"); static int sysctl_netinet_intr_direct_queue_drops(SYSCTL_HANDLER_ARGS) { u_int64_t qdrops_long; int error, qdrops; netisr_getqdrops(&ip_direct_nh, &qdrops_long); qdrops = qdrops_long; error = sysctl_handle_int(oidp, &qdrops, 0, req); if (error || !req->newptr) return (error); if (qdrops != 0) return (EINVAL); netisr_clearqdrops(&ip_direct_nh); return (0); } SYSCTL_PROC(_net_inet_ip, IPCTL_INTRDQDROPS, intr_direct_queue_drops, CTLTYPE_INT | CTLFLAG_RD | CTLFLAG_MPSAFE, 0, 0, sysctl_netinet_intr_direct_queue_drops, "I", "Number of packets dropped from the IP direct input queue"); #endif /* RSS */ /* * IP initialization: fill in IP protocol switch table. * All protocols not implemented in kernel go to raw IP protocol handler. */ static void ip_vnet_init(void *arg __unused) { struct pfil_head_args args; CK_STAILQ_INIT(&V_in_ifaddrhead); V_in_ifaddrhashtbl = hashinit(INADDR_NHASH, M_IFADDR, &V_in_ifaddrhmask); /* Initialize IP reassembly queue. */ - ipreass_init(); + ipreass_vnet_init(); /* Initialize packet filter hooks. */ args.pa_version = PFIL_VERSION; args.pa_flags = PFIL_IN | PFIL_OUT; args.pa_type = PFIL_TYPE_IP4; args.pa_headname = PFIL_INET_NAME; V_inet_pfil_head = pfil_head_register(&args); if (hhook_head_register(HHOOK_TYPE_IPSEC_IN, AF_INET, &V_ipsec_hhh_in[HHOOK_IPSEC_INET], HHOOK_WAITOK | HHOOK_HEADISINVNET) != 0) printf("%s: WARNING: unable to register input helper hook\n", __func__); if (hhook_head_register(HHOOK_TYPE_IPSEC_OUT, AF_INET, &V_ipsec_hhh_out[HHOOK_IPSEC_INET], HHOOK_WAITOK | HHOOK_HEADISINVNET) != 0) printf("%s: WARNING: unable to register output helper hook\n", __func__); #ifdef VIMAGE netisr_register_vnet(&ip_nh); #ifdef RSS netisr_register_vnet(&ip_direct_nh); #endif #endif } VNET_SYSINIT(ip_vnet_init, SI_SUB_PROTO_DOMAIN, SI_ORDER_FOURTH, ip_vnet_init, NULL); static void ip_init(const void *unused __unused) { + ipreass_init(); + /* * Register statically compiled protocols, that are unlikely to * ever become dynamic. */ IPPROTO_REGISTER(IPPROTO_ICMP, icmp_input, NULL); IPPROTO_REGISTER(IPPROTO_IGMP, igmp_input, NULL); IPPROTO_REGISTER(IPPROTO_RSVP, rsvp_input, NULL); IPPROTO_REGISTER(IPPROTO_IPV4, encap4_input, NULL); IPPROTO_REGISTER(IPPROTO_MOBILE, encap4_input, NULL); IPPROTO_REGISTER(IPPROTO_ETHERIP, encap4_input, NULL); IPPROTO_REGISTER(IPPROTO_GRE, encap4_input, NULL); IPPROTO_REGISTER(IPPROTO_IPV6, encap4_input, NULL); IPPROTO_REGISTER(IPPROTO_PIM, encap4_input, NULL); #ifdef SCTP /* XXX: has a loadable & static version */ IPPROTO_REGISTER(IPPROTO_SCTP, sctp_input, sctp_ctlinput); #endif netisr_register(&ip_nh); #ifdef RSS netisr_register(&ip_direct_nh); #endif } SYSINIT(ip_init, SI_SUB_PROTO_DOMAIN, SI_ORDER_THIRD, ip_init, NULL); #ifdef VIMAGE static void ip_destroy(void *unused __unused) { int error; #ifdef RSS netisr_unregister_vnet(&ip_direct_nh); #endif netisr_unregister_vnet(&ip_nh); pfil_head_unregister(V_inet_pfil_head); error = hhook_head_deregister(V_ipsec_hhh_in[HHOOK_IPSEC_INET]); if (error != 0) { printf("%s: WARNING: unable to deregister input helper hook " "type HHOOK_TYPE_IPSEC_IN, id HHOOK_IPSEC_INET: " "error %d returned\n", __func__, error); } error = hhook_head_deregister(V_ipsec_hhh_out[HHOOK_IPSEC_INET]); if (error != 0) { printf("%s: WARNING: unable to deregister output helper hook " "type HHOOK_TYPE_IPSEC_OUT, id HHOOK_IPSEC_INET: " "error %d returned\n", __func__, error); } /* Remove the IPv4 addresses from all interfaces. */ in_ifscrub_all(); /* Make sure the IPv4 routes are gone as well. */ rib_flush_routes_family(AF_INET); /* Destroy IP reassembly queue. */ ipreass_destroy(); /* Cleanup in_ifaddr hash table; should be empty. */ hashdestroy(V_in_ifaddrhashtbl, M_IFADDR, V_in_ifaddrhmask); } VNET_SYSUNINIT(ip, SI_SUB_PROTO_DOMAIN, SI_ORDER_THIRD, ip_destroy, NULL); #endif #ifdef RSS /* * IP direct input routine. * * This is called when reinjecting completed fragments where * all of the previous checking and book-keeping has been done. */ void ip_direct_input(struct mbuf *m) { struct ip *ip; int hlen; ip = mtod(m, struct ip *); hlen = ip->ip_hl << 2; #if defined(IPSEC) || defined(IPSEC_SUPPORT) if (IPSEC_ENABLED(ipv4)) { if (IPSEC_INPUT(ipv4, m, hlen, ip->ip_p) != 0) return; } #endif /* IPSEC */ IPSTAT_INC(ips_delivered); ip_protox[ip->ip_p](&m, &hlen, ip->ip_p); } #endif /* * Ip input routine. Checksum and byte swap header. If fragmented * try to reassemble. Process options. Pass to next level. */ void ip_input(struct mbuf *m) { struct ip *ip = NULL; struct in_ifaddr *ia = NULL; struct ifaddr *ifa; struct ifnet *ifp; int hlen = 0; uint16_t sum, ip_len; int dchg = 0; /* dest changed after fw */ struct in_addr odst; /* original dst address */ bool strong_es; M_ASSERTPKTHDR(m); NET_EPOCH_ASSERT(); if (m->m_flags & M_FASTFWD_OURS) { m->m_flags &= ~M_FASTFWD_OURS; /* Set up some basics that will be used later. */ ip = mtod(m, struct ip *); hlen = ip->ip_hl << 2; ip_len = ntohs(ip->ip_len); goto ours; } IPSTAT_INC(ips_total); if (__predict_false(m->m_pkthdr.len < sizeof(struct ip))) goto tooshort; if (m->m_len < sizeof(struct ip)) { m = m_pullup(m, sizeof(struct ip)); if (__predict_false(m == NULL)) { IPSTAT_INC(ips_toosmall); return; } } ip = mtod(m, struct ip *); if (__predict_false(ip->ip_v != IPVERSION)) { IPSTAT_INC(ips_badvers); goto bad; } hlen = ip->ip_hl << 2; if (__predict_false(hlen < sizeof(struct ip))) { /* minimum header length */ IPSTAT_INC(ips_badhlen); goto bad; } if (hlen > m->m_len) { m = m_pullup(m, hlen); if (__predict_false(m == NULL)) { IPSTAT_INC(ips_badhlen); return; } ip = mtod(m, struct ip *); } IP_PROBE(receive, NULL, NULL, ip, m->m_pkthdr.rcvif, ip, NULL); /* IN_LOOPBACK must not appear on the wire - RFC1122 */ ifp = m->m_pkthdr.rcvif; if (IN_LOOPBACK(ntohl(ip->ip_dst.s_addr)) || IN_LOOPBACK(ntohl(ip->ip_src.s_addr))) { if ((ifp->if_flags & IFF_LOOPBACK) == 0) { IPSTAT_INC(ips_badaddr); goto bad; } } if (m->m_pkthdr.csum_flags & CSUM_IP_CHECKED) { sum = !(m->m_pkthdr.csum_flags & CSUM_IP_VALID); } else { if (hlen == sizeof(struct ip)) { sum = in_cksum_hdr(ip); } else { sum = in_cksum(m, hlen); } } if (__predict_false(sum)) { IPSTAT_INC(ips_badsum); goto bad; } #ifdef ALTQ if (altq_input != NULL && (*altq_input)(m, AF_INET) == 0) /* packet is dropped by traffic conditioner */ return; #endif ip_len = ntohs(ip->ip_len); if (__predict_false(ip_len < hlen)) { IPSTAT_INC(ips_badlen); goto bad; } /* * Check that the amount of data in the buffers * is as at least much as the IP header would have us expect. * Trim mbufs if longer than we expect. * Drop packet if shorter than we expect. */ if (__predict_false(m->m_pkthdr.len < ip_len)) { tooshort: IPSTAT_INC(ips_tooshort); goto bad; } if (m->m_pkthdr.len > ip_len) { if (m->m_len == m->m_pkthdr.len) { m->m_len = ip_len; m->m_pkthdr.len = ip_len; } else m_adj(m, ip_len - m->m_pkthdr.len); } /* * Try to forward the packet, but if we fail continue. * ip_tryforward() may generate redirects these days. * XXX the logic below falling through to normal processing * if redirects are required should be revisited as well. * ip_tryforward() does inbound and outbound packet firewall * processing. If firewall has decided that destination becomes * our local address, it sets M_FASTFWD_OURS flag. In this * case skip another inbound firewall processing and update * ip pointer. */ if (V_ipforwarding != 0 #if defined(IPSEC) || defined(IPSEC_SUPPORT) && (!IPSEC_ENABLED(ipv4) || IPSEC_CAPS(ipv4, m, IPSEC_CAP_OPERABLE) == 0) #endif ) { /* * ip_dooptions() was run so we can ignore the source route (or * any IP options case) case for redirects in ip_tryforward(). */ if ((m = ip_tryforward(m)) == NULL) return; if (m->m_flags & M_FASTFWD_OURS) { m->m_flags &= ~M_FASTFWD_OURS; ip = mtod(m, struct ip *); goto ours; } } #if defined(IPSEC) || defined(IPSEC_SUPPORT) /* * Bypass packet filtering for packets previously handled by IPsec. */ if (IPSEC_ENABLED(ipv4) && IPSEC_CAPS(ipv4, m, IPSEC_CAP_BYPASS_FILTER) != 0) goto passin; #endif /* * Run through list of hooks for input packets. * * NB: Beware of the destination address changing (e.g. * by NAT rewriting). When this happens, tell * ip_forward to do the right thing. */ /* Jump over all PFIL processing if hooks are not active. */ if (!PFIL_HOOKED_IN(V_inet_pfil_head)) goto passin; odst = ip->ip_dst; if (pfil_run_hooks(V_inet_pfil_head, &m, ifp, PFIL_IN, NULL) != PFIL_PASS) return; if (m == NULL) /* consumed by filter */ return; ip = mtod(m, struct ip *); dchg = (odst.s_addr != ip->ip_dst.s_addr); if (m->m_flags & M_FASTFWD_OURS) { m->m_flags &= ~M_FASTFWD_OURS; goto ours; } if (m->m_flags & M_IP_NEXTHOP) { if (m_tag_find(m, PACKET_TAG_IPFORWARD, NULL) != NULL) { /* * Directly ship the packet on. This allows * forwarding packets originally destined to us * to some other directly connected host. */ ip_forward(m, 1); return; } } passin: /* * 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, 0)) return; /* greedy RSVP, snatches any PATH packet of the RSVP protocol and no * matter if it is destined to another node, or whether it is * a multicast one, RSVP wants it! and prevents it from being forwarded * anywhere else. Also checks if the rsvp daemon is running before * grabbing the packet. */ if (ip->ip_p == IPPROTO_RSVP && V_rsvp_on) goto ours; /* * Check our list of addresses, to see if the packet is for us. * If we don't have any addresses, assume any unicast packet * we receive might be for us (and let the upper layers deal * with it). */ if (CK_STAILQ_EMPTY(&V_in_ifaddrhead) && (m->m_flags & (M_MCAST|M_BCAST)) == 0) goto ours; /* * Enable a consistency check between the destination address * and the arrival interface for a unicast packet (the RFC 1122 * strong ES model) with a list of additional predicates: * - if IP forwarding is disabled * - the packet is not locally generated * - the packet is not subject to 'ipfw fwd' * - Interface is not running CARP. If the packet got here, we already * checked it with carp_iamatch() and carp_forus(). */ strong_es = V_ip_strong_es && (V_ipforwarding == 0) && ((ifp->if_flags & IFF_LOOPBACK) == 0) && ifp->if_carp == NULL && (dchg == 0); /* * Check for exact addresses in the hash bucket. */ CK_LIST_FOREACH(ia, INADDR_HASH(ip->ip_dst.s_addr), ia_hash) { if (IA_SIN(ia)->sin_addr.s_addr != ip->ip_dst.s_addr) continue; /* * net.inet.ip.rfc1122_strong_es: the address matches, verify * that the packet arrived via the correct interface. */ if (__predict_false(strong_es && ia->ia_ifp != ifp)) { IPSTAT_INC(ips_badaddr); goto bad; } /* * net.inet.ip.source_address_validation: drop incoming * packets that pretend to be ours. */ if (V_ip_sav && !(ifp->if_flags & IFF_LOOPBACK) && __predict_false(in_localip_fib(ip->ip_src, ifp->if_fib))) { IPSTAT_INC(ips_badaddr); goto bad; } counter_u64_add(ia->ia_ifa.ifa_ipackets, 1); counter_u64_add(ia->ia_ifa.ifa_ibytes, m->m_pkthdr.len); goto ours; } /* * Check for broadcast addresses. * * Only accept broadcast packets that arrive via the matching * interface. Reception of forwarded directed broadcasts would * be handled via ip_forward() and ether_output() with the loopback * into the stack for SIMPLEX interfaces handled by ether_output(). */ if (ifp->if_flags & IFF_BROADCAST) { CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) { if (ifa->ifa_addr->sa_family != AF_INET) continue; ia = ifatoia(ifa); if (satosin(&ia->ia_broadaddr)->sin_addr.s_addr == ip->ip_dst.s_addr) { counter_u64_add(ia->ia_ifa.ifa_ipackets, 1); counter_u64_add(ia->ia_ifa.ifa_ibytes, m->m_pkthdr.len); goto ours; } #ifdef BOOTP_COMPAT if (IA_SIN(ia)->sin_addr.s_addr == INADDR_ANY) { counter_u64_add(ia->ia_ifa.ifa_ipackets, 1); counter_u64_add(ia->ia_ifa.ifa_ibytes, m->m_pkthdr.len); goto ours; } #endif } ia = NULL; } if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr))) { /* * RFC 3927 2.7: Do not forward multicast packets from * IN_LINKLOCAL. */ if (V_ip_mrouter && !IN_LINKLOCAL(ntohl(ip->ip_src.s_addr))) { /* * 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. */ if (ip_mforward && ip_mforward(ip, ifp, m, 0) != 0) { IPSTAT_INC(ips_cantforward); m_freem(m); return; } /* * 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) { goto ours; } IPSTAT_INC(ips_forward); } /* * Assume the packet is for us, to avoid prematurely taking * a lock on the in_multi hash. Protocols must perform * their own filtering and update statistics accordingly. */ goto ours; } if (ip->ip_dst.s_addr == (u_long)INADDR_BROADCAST) goto ours; if (ip->ip_dst.s_addr == INADDR_ANY) goto ours; /* RFC 3927 2.7: Do not forward packets to or from IN_LINKLOCAL. */ if (IN_LINKLOCAL(ntohl(ip->ip_dst.s_addr)) || IN_LINKLOCAL(ntohl(ip->ip_src.s_addr))) { IPSTAT_INC(ips_cantforward); m_freem(m); return; } /* * Not for us; forward if possible and desirable. */ if (V_ipforwarding == 0) { IPSTAT_INC(ips_cantforward); m_freem(m); } else { ip_forward(m, dchg); } return; ours: #ifdef IPSTEALTH /* * IPSTEALTH: Process non-routing options only * if the packet is destined for us. */ if (V_ipstealth && hlen > sizeof (struct ip) && ip_dooptions(m, 1)) return; #endif /* IPSTEALTH */ /* * Attempt reassembly; if it succeeds, proceed. * ip_reass() will return a different mbuf. */ if (ip->ip_off & htons(IP_MF | IP_OFFMASK)) { /* XXXGL: shouldn't we save & set m_flags? */ m = ip_reass(m); if (m == NULL) return; ip = mtod(m, struct ip *); /* Get the header length of the reassembled packet */ hlen = ip->ip_hl << 2; } #if defined(IPSEC) || defined(IPSEC_SUPPORT) if (IPSEC_ENABLED(ipv4)) { if (IPSEC_INPUT(ipv4, m, hlen, ip->ip_p) != 0) return; } #endif /* IPSEC */ /* * Switch out to protocol's input routine. */ IPSTAT_INC(ips_delivered); ip_protox[ip->ip_p](&m, &hlen, ip->ip_p); return; bad: m_freem(m); } int ipproto_register(uint8_t proto, ipproto_input_t input, ipproto_ctlinput_t ctl) { MPASS(proto > 0); /* * The protocol slot must not be occupied by another protocol * already. An index pointing to rip_input() is unused. */ if (ip_protox[proto] == rip_input) { ip_protox[proto] = input; ip_ctlprotox[proto] = ctl; return (0); } else return (EEXIST); } int ipproto_unregister(uint8_t proto) { MPASS(proto > 0); if (ip_protox[proto] != rip_input) { ip_protox[proto] = rip_input; ip_ctlprotox[proto] = rip_ctlinput; return (0); } else return (ENOENT); } u_char inetctlerrmap[PRC_NCMDS] = { 0, 0, 0, 0, 0, EMSGSIZE, EHOSTDOWN, EHOSTUNREACH, EHOSTUNREACH, EHOSTUNREACH, ECONNREFUSED, ECONNREFUSED, EMSGSIZE, EHOSTUNREACH, 0, 0, 0, 0, EHOSTUNREACH, 0, ENOPROTOOPT, ECONNREFUSED }; /* * 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 ipforwarding 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, int srcrt) { struct ip *ip = mtod(m, struct ip *); struct in_ifaddr *ia; struct mbuf *mcopy; struct sockaddr_in *sin; struct in_addr dest; struct route ro; uint32_t flowid; int error, type = 0, code = 0, mtu = 0; NET_EPOCH_ASSERT(); if (m->m_flags & (M_BCAST|M_MCAST) || in_canforward(ip->ip_dst) == 0) { IPSTAT_INC(ips_cantforward); m_freem(m); return; } if ( #ifdef IPSTEALTH V_ipstealth == 0 && #endif ip->ip_ttl <= IPTTLDEC) { icmp_error(m, ICMP_TIMXCEED, ICMP_TIMXCEED_INTRANS, 0, 0); return; } bzero(&ro, sizeof(ro)); sin = (struct sockaddr_in *)&ro.ro_dst; sin->sin_family = AF_INET; sin->sin_len = sizeof(*sin); sin->sin_addr = ip->ip_dst; flowid = m->m_pkthdr.flowid; ro.ro_nh = fib4_lookup(M_GETFIB(m), ip->ip_dst, 0, NHR_REF, flowid); if (ro.ro_nh != NULL) { ia = ifatoia(ro.ro_nh->nh_ifa); } else ia = NULL; /* * Save the IP header and at most 8 bytes of the payload, * in case we need to generate an ICMP message to the src. * * XXX this can be optimized a lot by saving the data in a local * buffer on the stack (72 bytes at most), and only allocating the * mbuf if really necessary. The vast majority of the packets * are forwarded without having to send an ICMP back (either * because unnecessary, or because rate limited), so we are * really we are wasting a lot of work here. * * We don't use m_copym() because it might return a reference * to a shared cluster. Both this function and ip_output() * assume exclusive access to the IP header in `m', so any * data in a cluster may change before we reach icmp_error(). */ mcopy = m_gethdr(M_NOWAIT, m->m_type); if (mcopy != NULL && !m_dup_pkthdr(mcopy, m, M_NOWAIT)) { /* * It's probably ok if the pkthdr dup fails (because * the deep copy of the tag chain failed), but for now * be conservative and just discard the copy since * code below may some day want the tags. */ m_free(mcopy); mcopy = NULL; } if (mcopy != NULL) { mcopy->m_len = min(ntohs(ip->ip_len), M_TRAILINGSPACE(mcopy)); mcopy->m_pkthdr.len = mcopy->m_len; m_copydata(m, 0, mcopy->m_len, mtod(mcopy, caddr_t)); } #ifdef IPSTEALTH if (V_ipstealth == 0) #endif ip->ip_ttl -= IPTTLDEC; #if defined(IPSEC) || defined(IPSEC_SUPPORT) if (IPSEC_ENABLED(ipv4)) { if ((error = IPSEC_FORWARD(ipv4, m)) != 0) { /* mbuf consumed by IPsec */ RO_NHFREE(&ro); m_freem(mcopy); if (error != EINPROGRESS) IPSTAT_INC(ips_cantforward); return; } /* No IPsec processing required */ } #endif /* IPSEC */ /* * 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. */ dest.s_addr = 0; if (!srcrt && V_ipsendredirects && ia != NULL && ia->ia_ifp == m->m_pkthdr.rcvif) { struct nhop_object *nh; nh = ro.ro_nh; if (nh != NULL && ((nh->nh_flags & (NHF_REDIRECT|NHF_DEFAULT)) == 0)) { struct in_ifaddr *nh_ia = (struct in_ifaddr *)(nh->nh_ifa); u_long src = ntohl(ip->ip_src.s_addr); if (nh_ia != NULL && (src & nh_ia->ia_subnetmask) == nh_ia->ia_subnet) { /* Router requirements says to only send host redirects */ type = ICMP_REDIRECT; code = ICMP_REDIRECT_HOST; if (nh->nh_flags & NHF_GATEWAY) { if (nh->gw_sa.sa_family == AF_INET) dest.s_addr = nh->gw4_sa.sin_addr.s_addr; else /* Do not redirect in case gw is AF_INET6 */ type = 0; } else dest.s_addr = ip->ip_dst.s_addr; } } } error = ip_output(m, NULL, &ro, IP_FORWARDING, NULL, NULL); if (error == EMSGSIZE && ro.ro_nh) mtu = ro.ro_nh->nh_mtu; RO_NHFREE(&ro); if (error) IPSTAT_INC(ips_cantforward); else { IPSTAT_INC(ips_forward); if (type) IPSTAT_INC(ips_redirectsent); else { if (mcopy) m_freem(mcopy); return; } } if (mcopy == NULL) return; switch (error) { case 0: /* forwarded, but need redirect */ /* type, code set above */ break; case ENETUNREACH: case EHOSTUNREACH: case ENETDOWN: case EHOSTDOWN: default: type = ICMP_UNREACH; code = ICMP_UNREACH_HOST; break; case EMSGSIZE: type = ICMP_UNREACH; code = ICMP_UNREACH_NEEDFRAG; /* * If the MTU was set before make sure we are below the * interface MTU. * If the MTU wasn't set before use the interface mtu or * fall back to the next smaller mtu step compared to the * current packet size. */ if (mtu != 0) { if (ia != NULL) mtu = min(mtu, ia->ia_ifp->if_mtu); } else { if (ia != NULL) mtu = ia->ia_ifp->if_mtu; else mtu = ip_next_mtu(ntohs(ip->ip_len), 0); } IPSTAT_INC(ips_cantfrag); break; case ENOBUFS: case EACCES: /* ipfw denied packet */ m_freem(mcopy); return; } icmp_error(mcopy, type, code, dest.s_addr, mtu); } #define CHECK_SO_CT(sp, ct) \ (((sp->so_options & SO_TIMESTAMP) && (sp->so_ts_clock == ct)) ? 1 : 0) void ip_savecontrol(struct inpcb *inp, struct mbuf **mp, struct ip *ip, struct mbuf *m) { bool stamped; stamped = false; if ((inp->inp_socket->so_options & SO_BINTIME) || CHECK_SO_CT(inp->inp_socket, SO_TS_BINTIME)) { struct bintime boottimebin, bt; struct timespec ts1; if ((m->m_flags & (M_PKTHDR | M_TSTMP)) == (M_PKTHDR | M_TSTMP)) { mbuf_tstmp2timespec(m, &ts1); timespec2bintime(&ts1, &bt); getboottimebin(&boottimebin); bintime_add(&bt, &boottimebin); } else { bintime(&bt); } *mp = sbcreatecontrol(&bt, sizeof(bt), SCM_BINTIME, SOL_SOCKET, M_NOWAIT); if (*mp != NULL) { mp = &(*mp)->m_next; stamped = true; } } if (CHECK_SO_CT(inp->inp_socket, SO_TS_REALTIME_MICRO)) { struct bintime boottimebin, bt1; struct timespec ts1; struct timeval tv; if ((m->m_flags & (M_PKTHDR | M_TSTMP)) == (M_PKTHDR | M_TSTMP)) { mbuf_tstmp2timespec(m, &ts1); timespec2bintime(&ts1, &bt1); getboottimebin(&boottimebin); bintime_add(&bt1, &boottimebin); bintime2timeval(&bt1, &tv); } else { microtime(&tv); } *mp = sbcreatecontrol((caddr_t)&tv, sizeof(tv), SCM_TIMESTAMP, SOL_SOCKET, M_NOWAIT); if (*mp != NULL) { mp = &(*mp)->m_next; stamped = true; } } else if (CHECK_SO_CT(inp->inp_socket, SO_TS_REALTIME)) { struct bintime boottimebin; struct timespec ts, ts1; if ((m->m_flags & (M_PKTHDR | M_TSTMP)) == (M_PKTHDR | M_TSTMP)) { mbuf_tstmp2timespec(m, &ts); getboottimebin(&boottimebin); bintime2timespec(&boottimebin, &ts1); timespecadd(&ts, &ts1, &ts); } else { nanotime(&ts); } *mp = sbcreatecontrol(&ts, sizeof(ts), SCM_REALTIME, SOL_SOCKET, M_NOWAIT); if (*mp != NULL) { mp = &(*mp)->m_next; stamped = true; } } else if (CHECK_SO_CT(inp->inp_socket, SO_TS_MONOTONIC)) { struct timespec ts; if ((m->m_flags & (M_PKTHDR | M_TSTMP)) == (M_PKTHDR | M_TSTMP)) mbuf_tstmp2timespec(m, &ts); else nanouptime(&ts); *mp = sbcreatecontrol(&ts, sizeof(ts), SCM_MONOTONIC, SOL_SOCKET, M_NOWAIT); if (*mp != NULL) { mp = &(*mp)->m_next; stamped = true; } } if (stamped && (m->m_flags & (M_PKTHDR | M_TSTMP)) == (M_PKTHDR | M_TSTMP)) { struct sock_timestamp_info sti; bzero(&sti, sizeof(sti)); sti.st_info_flags = ST_INFO_HW; if ((m->m_flags & M_TSTMP_HPREC) != 0) sti.st_info_flags |= ST_INFO_HW_HPREC; *mp = sbcreatecontrol(&sti, sizeof(sti), SCM_TIME_INFO, SOL_SOCKET, M_NOWAIT); if (*mp != NULL) mp = &(*mp)->m_next; } if (inp->inp_flags & INP_RECVDSTADDR) { *mp = sbcreatecontrol(&ip->ip_dst, sizeof(struct in_addr), IP_RECVDSTADDR, IPPROTO_IP, M_NOWAIT); if (*mp) mp = &(*mp)->m_next; } if (inp->inp_flags & INP_RECVTTL) { *mp = sbcreatecontrol(&ip->ip_ttl, sizeof(u_char), IP_RECVTTL, IPPROTO_IP, M_NOWAIT); if (*mp) mp = &(*mp)->m_next; } #ifdef notyet /* XXX * Moving these out of udp_input() made them even more broken * than they already were. */ /* options were tossed already */ if (inp->inp_flags & INP_RECVOPTS) { *mp = sbcreatecontrol(opts_deleted_above, sizeof(struct in_addr), IP_RECVOPTS, IPPROTO_IP, M_NOWAIT); 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(ip_srcroute(m), sizeof(struct in_addr), IP_RECVRETOPTS, IPPROTO_IP, M_NOWAIT); if (*mp) mp = &(*mp)->m_next; } #endif if (inp->inp_flags & INP_RECVIF) { struct ifnet *ifp; struct sdlbuf { struct sockaddr_dl sdl; u_char pad[32]; } sdlbuf; struct sockaddr_dl *sdp; struct sockaddr_dl *sdl2 = &sdlbuf.sdl; if ((ifp = m->m_pkthdr.rcvif)) { sdp = (struct sockaddr_dl *)ifp->if_addr->ifa_addr; /* * Change our mind and don't try copy. */ if (sdp->sdl_family != AF_LINK || sdp->sdl_len > sizeof(sdlbuf)) { goto makedummy; } bcopy(sdp, sdl2, sdp->sdl_len); } else { makedummy: sdl2->sdl_len = offsetof(struct sockaddr_dl, sdl_data[0]); sdl2->sdl_family = AF_LINK; sdl2->sdl_index = 0; sdl2->sdl_nlen = sdl2->sdl_alen = sdl2->sdl_slen = 0; } *mp = sbcreatecontrol(sdl2, sdl2->sdl_len, IP_RECVIF, IPPROTO_IP, M_NOWAIT); if (*mp) mp = &(*mp)->m_next; } if (inp->inp_flags & INP_RECVTOS) { *mp = sbcreatecontrol(&ip->ip_tos, sizeof(u_char), IP_RECVTOS, IPPROTO_IP, M_NOWAIT); if (*mp) mp = &(*mp)->m_next; } if (inp->inp_flags2 & INP_RECVFLOWID) { uint32_t flowid, flow_type; flowid = m->m_pkthdr.flowid; flow_type = M_HASHTYPE_GET(m); /* * XXX should handle the failure of one or the * other - don't populate both? */ *mp = sbcreatecontrol(&flowid, sizeof(uint32_t), IP_FLOWID, IPPROTO_IP, M_NOWAIT); if (*mp) mp = &(*mp)->m_next; *mp = sbcreatecontrol(&flow_type, sizeof(uint32_t), IP_FLOWTYPE, IPPROTO_IP, M_NOWAIT); if (*mp) mp = &(*mp)->m_next; } #ifdef RSS if (inp->inp_flags2 & INP_RECVRSSBUCKETID) { uint32_t flowid, flow_type; uint32_t rss_bucketid; flowid = m->m_pkthdr.flowid; flow_type = M_HASHTYPE_GET(m); if (rss_hash2bucket(flowid, flow_type, &rss_bucketid) == 0) { *mp = sbcreatecontrol(&rss_bucketid, sizeof(uint32_t), IP_RSSBUCKETID, IPPROTO_IP, M_NOWAIT); if (*mp) mp = &(*mp)->m_next; } } #endif } /* * XXXRW: Multicast routing code in ip_mroute.c is generally MPSAFE, but the * ip_rsvp and ip_rsvp_on variables need to be interlocked with rsvp_on * locking. This code remains in ip_input.c as ip_mroute.c is optionally * compiled. */ VNET_DEFINE_STATIC(int, ip_rsvp_on); VNET_DEFINE(struct socket *, ip_rsvpd); #define V_ip_rsvp_on VNET(ip_rsvp_on) int ip_rsvp_init(struct socket *so) { if (so->so_type != SOCK_RAW || so->so_proto->pr_protocol != IPPROTO_RSVP) return EOPNOTSUPP; if (V_ip_rsvpd != NULL) return EADDRINUSE; V_ip_rsvpd = so; /* * This may seem silly, but we need to be sure we don't over-increment * the RSVP counter, in case something slips up. */ if (!V_ip_rsvp_on) { V_ip_rsvp_on = 1; V_rsvp_on++; } return 0; } int ip_rsvp_done(void) { V_ip_rsvpd = NULL; /* * This may seem silly, but we need to be sure we don't over-decrement * the RSVP counter, in case something slips up. */ if (V_ip_rsvp_on) { V_ip_rsvp_on = 0; V_rsvp_on--; } return 0; } int rsvp_input(struct mbuf **mp, int *offp, int proto) { struct mbuf *m; m = *mp; *mp = NULL; if (rsvp_input_p) { /* call the real one if loaded */ *mp = m; rsvp_input_p(mp, offp, proto); return (IPPROTO_DONE); } /* Can still get packets with rsvp_on = 0 if there is a local member * of the group to which the RSVP packet is addressed. But in this * case we want to throw the packet away. */ if (!V_rsvp_on) { m_freem(m); return (IPPROTO_DONE); } if (V_ip_rsvpd != NULL) { *mp = m; rip_input(mp, offp, proto); return (IPPROTO_DONE); } /* Drop the packet */ m_freem(m); return (IPPROTO_DONE); } diff --git a/sys/netinet/ip_reass.c b/sys/netinet/ip_reass.c index a0a8dd42b758..0420091e0a2a 100644 --- a/sys/netinet/ip_reass.c +++ b/sys/netinet/ip_reass.c @@ -1,890 +1,894 @@ /*- * Copyright (c) 2015 Gleb Smirnoff * Copyright (c) 2015 Adrian Chadd * 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 __FBSDID("$FreeBSD$"); #include "opt_rss.h" #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #ifdef MAC #include #endif SYSCTL_DECL(_net_inet_ip); /* * Reassembly headers are stored in hash buckets. */ #define IPREASS_NHASH_LOG2 10 #define IPREASS_NHASH (1 << IPREASS_NHASH_LOG2) #define IPREASS_HMASK (IPREASS_NHASH - 1) struct ipqbucket { TAILQ_HEAD(ipqhead, ipq) head; struct mtx lock; int count; }; VNET_DEFINE_STATIC(struct ipqbucket, ipq[IPREASS_NHASH]); #define V_ipq VNET(ipq) VNET_DEFINE_STATIC(uint32_t, ipq_hashseed); #define V_ipq_hashseed VNET(ipq_hashseed) #define IPQ_LOCK(i) mtx_lock(&V_ipq[i].lock) #define IPQ_TRYLOCK(i) mtx_trylock(&V_ipq[i].lock) #define IPQ_UNLOCK(i) mtx_unlock(&V_ipq[i].lock) #define IPQ_LOCK_ASSERT(i) mtx_assert(&V_ipq[i].lock, MA_OWNED) VNET_DEFINE_STATIC(int, ipreass_maxbucketsize); #define V_ipreass_maxbucketsize VNET(ipreass_maxbucketsize) void ipreass_init(void); +void ipreass_vnet_init(void); #ifdef VIMAGE void ipreass_destroy(void); #endif static int sysctl_maxfragpackets(SYSCTL_HANDLER_ARGS); static int sysctl_maxfragbucketsize(SYSCTL_HANDLER_ARGS); static void ipreass_zone_change(void *); static void ipreass_drain_tomax(void); static void ipq_free(struct ipqbucket *, struct ipq *); static struct ipq * ipq_reuse(int); static inline void ipq_timeout(struct ipqbucket *bucket, struct ipq *fp) { IPSTAT_ADD(ips_fragtimeout, fp->ipq_nfrags); ipq_free(bucket, fp); } static inline void ipq_drop(struct ipqbucket *bucket, struct ipq *fp) { IPSTAT_ADD(ips_fragdropped, fp->ipq_nfrags); ipq_free(bucket, fp); } /* * By default, limit the number of IP fragments across all reassembly * queues to 1/32 of the total number of mbuf clusters. * * Limit the total number of reassembly queues per VNET to the * IP fragment limit, but ensure the limit will not allow any bucket * to grow above 100 items. (The bucket limit is * IP_MAXFRAGPACKETS / (IPREASS_NHASH / 2), so the 50 is the correct * multiplier to reach a 100-item limit.) * The 100-item limit was chosen as brief testing seems to show that * this produces "reasonable" performance on some subset of systems * under DoS attack. */ #define IP_MAXFRAGS (nmbclusters / 32) #define IP_MAXFRAGPACKETS (imin(IP_MAXFRAGS, IPREASS_NHASH * 50)) static int maxfrags; static u_int __exclusive_cache_line nfrags; SYSCTL_INT(_net_inet_ip, OID_AUTO, maxfrags, CTLFLAG_RW, &maxfrags, 0, "Maximum number of IPv4 fragments allowed across all reassembly queues"); SYSCTL_UINT(_net_inet_ip, OID_AUTO, curfrags, CTLFLAG_RD, &nfrags, 0, "Current number of IPv4 fragments across all reassembly queues"); VNET_DEFINE_STATIC(uma_zone_t, ipq_zone); #define V_ipq_zone VNET(ipq_zone) SYSCTL_PROC(_net_inet_ip, OID_AUTO, maxfragpackets, CTLFLAG_VNET | CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_NEEDGIANT, NULL, 0, sysctl_maxfragpackets, "I", "Maximum number of IPv4 fragment reassembly queue entries"); SYSCTL_UMA_CUR(_net_inet_ip, OID_AUTO, fragpackets, CTLFLAG_VNET, &VNET_NAME(ipq_zone), "Current number of IPv4 fragment reassembly queue entries"); VNET_DEFINE_STATIC(int, noreass); #define V_noreass VNET(noreass) VNET_DEFINE_STATIC(int, maxfragsperpacket); #define V_maxfragsperpacket VNET(maxfragsperpacket) SYSCTL_INT(_net_inet_ip, OID_AUTO, maxfragsperpacket, CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(maxfragsperpacket), 0, "Maximum number of IPv4 fragments allowed per packet"); SYSCTL_PROC(_net_inet_ip, OID_AUTO, maxfragbucketsize, CTLFLAG_VNET | CTLTYPE_INT | CTLFLAG_MPSAFE | CTLFLAG_RW, NULL, 0, sysctl_maxfragbucketsize, "I", "Maximum number of IPv4 fragment reassembly queue entries per bucket"); /* * Take incoming datagram fragment and try to reassemble it into * whole datagram. If the argument is the first fragment or one * in between the function will return NULL and store the mbuf * in the fragment chain. If the argument is the last fragment * the packet will be reassembled and the pointer to the new * mbuf returned for further processing. Only m_tags attached * to the first packet/fragment are preserved. * The IP header is *NOT* adjusted out of iplen. */ #define M_IP_FRAG M_PROTO9 struct mbuf * ip_reass(struct mbuf *m) { struct ip *ip; struct mbuf *p, *q, *nq, *t; struct ipq *fp; struct ifnet *srcifp; struct ipqhead *head; int i, hlen, next, tmpmax; u_int8_t ecn, ecn0; uint32_t hash, hashkey[3]; #ifdef RSS uint32_t rss_hash, rss_type; #endif /* * If no reassembling or maxfragsperpacket are 0, * never accept fragments. * Also, drop packet if it would exceed the maximum * number of fragments. */ tmpmax = maxfrags; if (V_noreass == 1 || V_maxfragsperpacket == 0 || (tmpmax >= 0 && atomic_load_int(&nfrags) >= (u_int)tmpmax)) { IPSTAT_INC(ips_fragments); IPSTAT_INC(ips_fragdropped); m_freem(m); return (NULL); } ip = mtod(m, struct ip *); hlen = ip->ip_hl << 2; /* * Adjust ip_len to not reflect header, * convert offset of this to bytes. */ ip->ip_len = htons(ntohs(ip->ip_len) - hlen); /* * Make sure that fragments have a data length * that's a non-zero multiple of 8 bytes, unless * this is the last fragment. */ if (ip->ip_len == htons(0) || ((ip->ip_off & htons(IP_MF)) && (ntohs(ip->ip_len) & 0x7) != 0)) { IPSTAT_INC(ips_toosmall); /* XXX */ IPSTAT_INC(ips_fragdropped); m_freem(m); return (NULL); } if (ip->ip_off & htons(IP_MF)) m->m_flags |= M_IP_FRAG; else m->m_flags &= ~M_IP_FRAG; ip->ip_off = htons(ntohs(ip->ip_off) << 3); /* * Make sure the fragment lies within a packet of valid size. */ if (ntohs(ip->ip_len) + ntohs(ip->ip_off) > IP_MAXPACKET) { IPSTAT_INC(ips_toolong); IPSTAT_INC(ips_fragdropped); m_freem(m); return (NULL); } /* * Store receive network interface pointer for later. */ srcifp = m->m_pkthdr.rcvif; /* * Attempt reassembly; if it succeeds, proceed. * ip_reass() will return a different mbuf. */ IPSTAT_INC(ips_fragments); m->m_pkthdr.PH_loc.ptr = ip; /* * Presence of header sizes in mbufs * would confuse code below. */ m->m_data += hlen; m->m_len -= hlen; hashkey[0] = ip->ip_src.s_addr; hashkey[1] = ip->ip_dst.s_addr; hashkey[2] = (uint32_t)ip->ip_p << 16; hashkey[2] += ip->ip_id; hash = jenkins_hash32(hashkey, nitems(hashkey), V_ipq_hashseed); hash &= IPREASS_HMASK; head = &V_ipq[hash].head; IPQ_LOCK(hash); /* * Look for queue of fragments * of this datagram. */ TAILQ_FOREACH(fp, head, ipq_list) 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 && #ifdef MAC mac_ipq_match(m, fp) && #endif ip->ip_p == fp->ipq_p) break; /* * If first fragment to arrive, create a reassembly queue. */ if (fp == NULL) { if (V_ipq[hash].count < V_ipreass_maxbucketsize) fp = uma_zalloc(V_ipq_zone, M_NOWAIT); if (fp == NULL) fp = ipq_reuse(hash); if (fp == NULL) goto dropfrag; #ifdef MAC if (mac_ipq_init(fp, M_NOWAIT) != 0) { uma_zfree(V_ipq_zone, fp); fp = NULL; goto dropfrag; } mac_ipq_create(m, fp); #endif TAILQ_INSERT_HEAD(head, fp, ipq_list); V_ipq[hash].count++; fp->ipq_nfrags = 1; atomic_add_int(&nfrags, 1); fp->ipq_ttl = IPFRAGTTL; fp->ipq_p = ip->ip_p; fp->ipq_id = ip->ip_id; fp->ipq_src = ip->ip_src; fp->ipq_dst = ip->ip_dst; fp->ipq_frags = m; if (m->m_flags & M_IP_FRAG) fp->ipq_maxoff = -1; else fp->ipq_maxoff = ntohs(ip->ip_off) + ntohs(ip->ip_len); m->m_nextpkt = NULL; goto done; } else { /* * If we already saw the last fragment, make sure * this fragment's offset looks sane. Otherwise, if * this is the last fragment, record its endpoint. */ if (fp->ipq_maxoff > 0) { i = ntohs(ip->ip_off) + ntohs(ip->ip_len); if (((m->m_flags & M_IP_FRAG) && i >= fp->ipq_maxoff) || ((m->m_flags & M_IP_FRAG) == 0 && i != fp->ipq_maxoff)) { fp = NULL; goto dropfrag; } } else if ((m->m_flags & M_IP_FRAG) == 0) fp->ipq_maxoff = ntohs(ip->ip_off) + ntohs(ip->ip_len); fp->ipq_nfrags++; atomic_add_int(&nfrags, 1); #ifdef MAC mac_ipq_update(m, fp); #endif } #define GETIP(m) ((struct ip*)((m)->m_pkthdr.PH_loc.ptr)) /* * 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 = ip->ip_tos & IPTOS_ECN_MASK; ecn0 = GETIP(fp->ipq_frags)->ip_tos & IPTOS_ECN_MASK; if (ecn == IPTOS_ECN_CE) { if (ecn0 == IPTOS_ECN_NOTECT) goto dropfrag; if (ecn0 != IPTOS_ECN_CE) GETIP(fp->ipq_frags)->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 = fp->ipq_frags; q; p = q, q = q->m_nextpkt) if (ntohs(GETIP(q)->ip_off) > ntohs(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, otherwise * stick new segment in the proper place. * * If some of the data is dropped from the preceding * segment, then it's checksum is invalidated. */ if (p) { i = ntohs(GETIP(p)->ip_off) + ntohs(GETIP(p)->ip_len) - ntohs(ip->ip_off); if (i > 0) { if (i >= ntohs(ip->ip_len)) goto dropfrag; m_adj(m, i); m->m_pkthdr.csum_flags = 0; ip->ip_off = htons(ntohs(ip->ip_off) + i); ip->ip_len = htons(ntohs(ip->ip_len) - i); } m->m_nextpkt = p->m_nextpkt; p->m_nextpkt = m; } else { m->m_nextpkt = fp->ipq_frags; fp->ipq_frags = m; } /* * While we overlap succeeding segments trim them or, * if they are completely covered, dequeue them. */ for (; q != NULL && ntohs(ip->ip_off) + ntohs(ip->ip_len) > ntohs(GETIP(q)->ip_off); q = nq) { i = (ntohs(ip->ip_off) + ntohs(ip->ip_len)) - ntohs(GETIP(q)->ip_off); if (i < ntohs(GETIP(q)->ip_len)) { GETIP(q)->ip_len = htons(ntohs(GETIP(q)->ip_len) - i); GETIP(q)->ip_off = htons(ntohs(GETIP(q)->ip_off) + i); m_adj(q, i); q->m_pkthdr.csum_flags = 0; break; } nq = q->m_nextpkt; m->m_nextpkt = nq; IPSTAT_INC(ips_fragdropped); fp->ipq_nfrags--; atomic_subtract_int(&nfrags, 1); m_freem(q); } /* * Check for complete reassembly and perform frag per packet * limiting. * * Frag limiting is performed here so that the nth frag has * a chance to complete the packet before we drop the packet. * As a result, n+1 frags are actually allowed per packet, but * only n will ever be stored. (n = maxfragsperpacket.) * */ next = 0; for (p = NULL, q = fp->ipq_frags; q; p = q, q = q->m_nextpkt) { if (ntohs(GETIP(q)->ip_off) != next) { if (fp->ipq_nfrags > V_maxfragsperpacket) ipq_drop(&V_ipq[hash], fp); goto done; } next += ntohs(GETIP(q)->ip_len); } /* Make sure the last packet didn't have the IP_MF flag */ if (p->m_flags & M_IP_FRAG) { if (fp->ipq_nfrags > V_maxfragsperpacket) ipq_drop(&V_ipq[hash], fp); goto done; } /* * Reassembly is complete. Make sure the packet is a sane size. */ q = fp->ipq_frags; ip = GETIP(q); if (next + (ip->ip_hl << 2) > IP_MAXPACKET) { IPSTAT_INC(ips_toolong); ipq_drop(&V_ipq[hash], fp); goto done; } /* * Concatenate fragments. */ m = q; t = m->m_next; m->m_next = NULL; m_cat(m, t); nq = q->m_nextpkt; q->m_nextpkt = NULL; for (q = nq; q != NULL; q = nq) { nq = q->m_nextpkt; q->m_nextpkt = NULL; m->m_pkthdr.csum_flags &= q->m_pkthdr.csum_flags; m->m_pkthdr.csum_data += q->m_pkthdr.csum_data; m_demote_pkthdr(q); m_cat(m, q); } /* * In order to do checksumming faster we do 'end-around carry' here * (and not in for{} loop), though it implies we are not going to * reassemble more than 64k fragments. */ while (m->m_pkthdr.csum_data & 0xffff0000) m->m_pkthdr.csum_data = (m->m_pkthdr.csum_data & 0xffff) + (m->m_pkthdr.csum_data >> 16); atomic_subtract_int(&nfrags, fp->ipq_nfrags); #ifdef MAC mac_ipq_reassemble(fp, m); mac_ipq_destroy(fp); #endif /* * 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((ip->ip_hl << 2) + next); ip->ip_src = fp->ipq_src; ip->ip_dst = fp->ipq_dst; TAILQ_REMOVE(head, fp, ipq_list); V_ipq[hash].count--; uma_zfree(V_ipq_zone, fp); m->m_len += (ip->ip_hl << 2); m->m_data -= (ip->ip_hl << 2); /* some debugging cruft by sklower, below, will go away soon */ if (m->m_flags & M_PKTHDR) { /* XXX this should be done elsewhere */ m_fixhdr(m); /* set valid receive interface pointer */ m->m_pkthdr.rcvif = srcifp; } IPSTAT_INC(ips_reassembled); IPQ_UNLOCK(hash); #ifdef RSS /* * Query the RSS layer for the flowid / flowtype for the * mbuf payload. * * For now, just assume we have to calculate a new one. * Later on we should check to see if the assigned flowid matches * what RSS wants for the given IP protocol and if so, just keep it. * * We then queue into the relevant netisr so it can be dispatched * to the correct CPU. * * Note - this may return 1, which means the flowid in the mbuf * is correct for the configured RSS hash types and can be used. */ if (rss_mbuf_software_hash_v4(m, 0, &rss_hash, &rss_type) == 0) { m->m_pkthdr.flowid = rss_hash; M_HASHTYPE_SET(m, rss_type); } /* * Queue/dispatch for reprocessing. * * Note: this is much slower than just handling the frame in the * current receive context. It's likely worth investigating * why this is. */ netisr_dispatch(NETISR_IP_DIRECT, m); return (NULL); #endif /* Handle in-line */ return (m); dropfrag: IPSTAT_INC(ips_fragdropped); if (fp != NULL) { fp->ipq_nfrags--; atomic_subtract_int(&nfrags, 1); } m_freem(m); done: IPQ_UNLOCK(hash); return (NULL); #undef GETIP } /* * If a timer expires on a reassembly queue, discard it. */ static struct callout ipreass_callout; static void ipreass_slowtimo(void *arg __unused) { VNET_ITERATOR_DECL(vnet_iter); struct ipq *fp, *tmp; if (atomic_load_int(&nfrags) == 0) return; VNET_FOREACH(vnet_iter) { CURVNET_SET(vnet_iter); for (int i = 0; i < IPREASS_NHASH; i++) { if (TAILQ_EMPTY(&V_ipq[i].head)) continue; IPQ_LOCK(i); TAILQ_FOREACH_SAFE(fp, &V_ipq[i].head, ipq_list, tmp) if (--fp->ipq_ttl == 0) ipq_timeout(&V_ipq[i], fp); IPQ_UNLOCK(i); } CURVNET_RESTORE(); } VNET_LIST_RUNLOCK_NOSLEEP(); callout_reset_sbt(&ipreass_callout, SBT_1MS * 500, SBT_1MS * 10, ipreass_slowtimo, NULL, 0); } static void ipreass_timer_init(void *arg __unused) { callout_init(&ipreass_callout, 1); callout_reset_sbt(&ipreass_callout, SBT_1MS * 500, SBT_1MS * 10, ipreass_slowtimo, NULL, 0); } SYSINIT(ipreass, SI_SUB_VNET_DONE, SI_ORDER_ANY, ipreass_timer_init, NULL); /* * Drain off all datagram fragments. */ static void ipreass_drain(void) { VNET_ITERATOR_DECL(vnet_iter); VNET_FOREACH(vnet_iter) { CURVNET_SET(vnet_iter); for (int i = 0; i < IPREASS_NHASH; i++) { IPQ_LOCK(i); while(!TAILQ_EMPTY(&V_ipq[i].head)) ipq_drop(&V_ipq[i], TAILQ_FIRST(&V_ipq[i].head)); KASSERT(V_ipq[i].count == 0, ("%s: V_ipq[%d] count %d (V_ipq=%p)", __func__, i, V_ipq[i].count, V_ipq)); IPQ_UNLOCK(i); } CURVNET_RESTORE(); } } /* * Initialize IP reassembly structures. */ void -ipreass_init(void) +ipreass_vnet_init(void) { int max; for (int i = 0; i < IPREASS_NHASH; i++) { TAILQ_INIT(&V_ipq[i].head); mtx_init(&V_ipq[i].lock, "IP reassembly", NULL, MTX_DEF | MTX_DUPOK); V_ipq[i].count = 0; } V_ipq_hashseed = arc4random(); V_maxfragsperpacket = 16; V_ipq_zone = uma_zcreate("ipq", sizeof(struct ipq), NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0); max = IP_MAXFRAGPACKETS; max = uma_zone_set_max(V_ipq_zone, max); V_ipreass_maxbucketsize = imax(max / (IPREASS_NHASH / 2), 1); +} - if (IS_DEFAULT_VNET(curvnet)) { - maxfrags = IP_MAXFRAGS; - EVENTHANDLER_REGISTER(nmbclusters_change, ipreass_zone_change, - NULL, EVENTHANDLER_PRI_ANY); - EVENTHANDLER_REGISTER(vm_lowmem, ipreass_drain, NULL, - LOWMEM_PRI_DEFAULT); - EVENTHANDLER_REGISTER(mbuf_lowmem, ipreass_drain, NULL, - LOWMEM_PRI_DEFAULT); - } +void +ipreass_init(void) +{ + + maxfrags = IP_MAXFRAGS; + EVENTHANDLER_REGISTER(nmbclusters_change, ipreass_zone_change, + NULL, EVENTHANDLER_PRI_ANY); + EVENTHANDLER_REGISTER(vm_lowmem, ipreass_drain, NULL, + LOWMEM_PRI_DEFAULT); + EVENTHANDLER_REGISTER(mbuf_lowmem, ipreass_drain, NULL, + LOWMEM_PRI_DEFAULT); } /* * Drain off all datagram fragments belonging to * the given network interface. */ static void ipreass_cleanup(void *arg __unused, struct ifnet *ifp) { struct ipq *fp, *temp; struct mbuf *m; int i; KASSERT(ifp != NULL, ("%s: ifp is NULL", __func__)); CURVNET_SET_QUIET(ifp->if_vnet); /* * Skip processing if IPv4 reassembly is not initialised or * torn down by ipreass_destroy(). */ if (V_ipq_zone == NULL) { CURVNET_RESTORE(); return; } for (i = 0; i < IPREASS_NHASH; i++) { IPQ_LOCK(i); /* Scan fragment list. */ TAILQ_FOREACH_SAFE(fp, &V_ipq[i].head, ipq_list, temp) { for (m = fp->ipq_frags; m != NULL; m = m->m_nextpkt) { /* clear no longer valid rcvif pointer */ if (m->m_pkthdr.rcvif == ifp) m->m_pkthdr.rcvif = NULL; } } IPQ_UNLOCK(i); } CURVNET_RESTORE(); } EVENTHANDLER_DEFINE(ifnet_departure_event, ipreass_cleanup, NULL, 0); #ifdef VIMAGE /* * Destroy IP reassembly structures. */ void ipreass_destroy(void) { ipreass_drain(); uma_zdestroy(V_ipq_zone); V_ipq_zone = NULL; for (int i = 0; i < IPREASS_NHASH; i++) mtx_destroy(&V_ipq[i].lock); } #endif /* * After maxnipq has been updated, propagate the change to UMA. The UMA zone * max has slightly different semantics than the sysctl, for historical * reasons. */ static void ipreass_drain_tomax(void) { struct ipq *fp; int target; /* * Make sure each bucket is under the new limit. If * necessary, drop enough of the oldest elements from * each bucket to get under the new limit. */ for (int i = 0; i < IPREASS_NHASH; i++) { IPQ_LOCK(i); while (V_ipq[i].count > V_ipreass_maxbucketsize && (fp = TAILQ_LAST(&V_ipq[i].head, ipqhead)) != NULL) ipq_timeout(&V_ipq[i], fp); IPQ_UNLOCK(i); } /* * If we are over the maximum number of fragments, * drain off enough to get down to the new limit, * stripping off last elements on queues. Every * run we strip the oldest element from each bucket. */ target = uma_zone_get_max(V_ipq_zone); while (uma_zone_get_cur(V_ipq_zone) > target) { for (int i = 0; i < IPREASS_NHASH; i++) { IPQ_LOCK(i); fp = TAILQ_LAST(&V_ipq[i].head, ipqhead); if (fp != NULL) ipq_timeout(&V_ipq[i], fp); IPQ_UNLOCK(i); } } } static void ipreass_zone_change(void *tag) { VNET_ITERATOR_DECL(vnet_iter); int max; maxfrags = IP_MAXFRAGS; max = IP_MAXFRAGPACKETS; VNET_LIST_RLOCK_NOSLEEP(); VNET_FOREACH(vnet_iter) { CURVNET_SET(vnet_iter); max = uma_zone_set_max(V_ipq_zone, max); V_ipreass_maxbucketsize = imax(max / (IPREASS_NHASH / 2), 1); ipreass_drain_tomax(); CURVNET_RESTORE(); } VNET_LIST_RUNLOCK_NOSLEEP(); } /* * Change the limit on the UMA zone, or disable the fragment allocation * at all. Since 0 and -1 is a special values here, we need our own handler, * instead of sysctl_handle_uma_zone_max(). */ static int sysctl_maxfragpackets(SYSCTL_HANDLER_ARGS) { int error, max; if (V_noreass == 0) { max = uma_zone_get_max(V_ipq_zone); if (max == 0) max = -1; } else max = 0; error = sysctl_handle_int(oidp, &max, 0, req); if (error || !req->newptr) return (error); if (max > 0) { /* * XXXRW: Might be a good idea to sanity check the argument * and place an extreme upper bound. */ max = uma_zone_set_max(V_ipq_zone, max); V_ipreass_maxbucketsize = imax(max / (IPREASS_NHASH / 2), 1); ipreass_drain_tomax(); V_noreass = 0; } else if (max == 0) { V_noreass = 1; ipreass_drain(); } else if (max == -1) { V_noreass = 0; uma_zone_set_max(V_ipq_zone, 0); V_ipreass_maxbucketsize = INT_MAX; } else return (EINVAL); return (0); } /* * Seek for old fragment queue header that can be reused. Try to * reuse a header from currently locked hash bucket. */ static struct ipq * ipq_reuse(int start) { struct ipq *fp; int bucket, i; IPQ_LOCK_ASSERT(start); for (i = 0; i < IPREASS_NHASH; i++) { bucket = (start + i) % IPREASS_NHASH; if (bucket != start && IPQ_TRYLOCK(bucket) == 0) continue; fp = TAILQ_LAST(&V_ipq[bucket].head, ipqhead); if (fp) { struct mbuf *m; IPSTAT_ADD(ips_fragtimeout, fp->ipq_nfrags); atomic_subtract_int(&nfrags, fp->ipq_nfrags); while (fp->ipq_frags) { m = fp->ipq_frags; fp->ipq_frags = m->m_nextpkt; m_freem(m); } TAILQ_REMOVE(&V_ipq[bucket].head, fp, ipq_list); V_ipq[bucket].count--; if (bucket != start) IPQ_UNLOCK(bucket); break; } if (bucket != start) IPQ_UNLOCK(bucket); } IPQ_LOCK_ASSERT(start); return (fp); } /* * Free a fragment reassembly header and all associated datagrams. */ static void ipq_free(struct ipqbucket *bucket, struct ipq *fp) { struct mbuf *q; atomic_subtract_int(&nfrags, fp->ipq_nfrags); while (fp->ipq_frags) { q = fp->ipq_frags; fp->ipq_frags = q->m_nextpkt; m_freem(q); } TAILQ_REMOVE(&bucket->head, fp, ipq_list); bucket->count--; uma_zfree(V_ipq_zone, fp); } /* * Get or set the maximum number of reassembly queues per bucket. */ static int sysctl_maxfragbucketsize(SYSCTL_HANDLER_ARGS) { int error, max; max = V_ipreass_maxbucketsize; error = sysctl_handle_int(oidp, &max, 0, req); if (error || !req->newptr) return (error); if (max <= 0) return (EINVAL); V_ipreass_maxbucketsize = max; ipreass_drain_tomax(); return (0); }