| /*- |
| * 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. |
| * 4. Neither the name of the University nor the names of its contributors |
| * may be used to endorse or promote products derived from this software |
| * without specific prior written permission. |
| * |
| * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND |
| * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
| * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
| * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE |
| * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
| * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS |
| * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
| * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
| * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY |
| * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
| * SUCH DAMAGE. |
| * |
| * @(#)ip_input.c 8.2 (Berkeley) 1/4/94 |
| */ |
| |
| #include <sys/bsd_cdefs.h> |
| //__FBSDID("$FreeBSD$"); |
| |
| #include "bsd_opt_bootp.h" |
| #include "bsd_opt_ipfw.h" |
| #include "bsd_opt_ipstealth.h" |
| #include "bsd_opt_ipsec.h" |
| #include "bsd_opt_route.h" |
| #include "bsd_opt_carp.h" |
| |
| #include <sys/bsd_param.h> |
| #include <sys/bsd_systm.h> |
| #include <sys/bsd_callout.h> |
| #include <sys/bsd_mbuf.h> |
| #include <sys/bsd_malloc.h> |
| #include <sys/bsd_domain.h> |
| #include <sys/bsd_protosw.h> |
| #include <sys/bsd_socket.h> |
| #include <sys/bsd_time.h> |
| #include <sys/bsd_kernel.h> |
| #include <sys/bsd_lock.h> |
| #include <sys/bsd_rwlock.h> |
| #include <sys/bsd_syslog.h> |
| //baoyg//#include <sys/bsd_sysctl.h> |
| |
| //#include <net/bsd_pfil.h> |
| #include <net/bsd_if.h> |
| #include <net/bsd_if_types.h> |
| #include <net/bsd_if_var.h> |
| #include <net/bsd_if_dl.h> |
| #include <net/bsd_route.h> |
| #include <net/bsd_netisr.h> |
| #include <net/bsd_vnet.h> |
| #include <net/bsd_flowtable.h> |
| |
| #include <netinet/bsd_in.h> |
| #include <netinet/bsd_in_systm.h> |
| #include <netinet/bsd_in_var.h> |
| #include <netinet/bsd_ip.h> |
| #include <netinet/bsd_in_pcb.h> |
| #include <netinet/bsd_ip_var.h> |
| #include <netinet/bsd_ip_fw.h> |
| #include <netinet/bsd_ip_icmp.h> |
| #include <netinet/bsd_ip_options.h> |
| #include <machine/bsd_in_cksum.h> |
| #ifdef DEV_CARP |
| #include <netinet/bsd_ip_carp.h> |
| #endif |
| #ifdef IPSEC |
| #include <netinet/bsd_ip_ipsec.h> |
| #endif /* IPSEC */ |
| |
| #include <sys/bsd_socketvar.h> |
| |
| #ifdef MAC |
| #include <security/mac/bsd_mac_framework.h> |
| #endif |
| |
| #include "uptcp_statis.h" |
| |
| #ifdef CTASSERT |
| CTASSERT(sizeof(struct ip) == 20); |
| #endif |
| |
| static VNET_DEFINE(int, ipsendredirects) = 1; /* XXX */ |
| static VNET_DEFINE(int, ip_checkinterface); |
| static VNET_DEFINE(int, ip_keepfaith); |
| static VNET_DEFINE(int, ip_sendsourcequench); |
| |
| #define V_ipsendredirects VNET(ipsendredirects) |
| #define V_ip_checkinterface VNET(ip_checkinterface) |
| #define V_ip_keepfaith VNET(ip_keepfaith) |
| #define V_ip_sendsourcequench VNET(ip_sendsourcequench) |
| |
| VNET_DEFINE(int, ip_defttl) = IPDEFTTL; |
| VNET_DEFINE(int, ip_do_randomid); |
| VNET_DEFINE(int, ipforwarding); |
| |
| 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 */ |
| VNET_DEFINE(struct ipstat, ipstat); |
| |
| static VNET_DEFINE(int, ip_rsvp_on); |
| VNET_DEFINE(struct socket *, ip_rsvpd); |
| VNET_DEFINE(int, rsvp_on); |
| |
| #define V_ip_rsvp_on VNET(ip_rsvp_on) |
| |
| static VNET_DEFINE(TAILQ_HEAD(ipqhead, ipq), ipq[IPREASS_NHASH]); |
| static VNET_DEFINE(int, maxnipq); /* Administrative limit on # reass queues. */ |
| static VNET_DEFINE(int, maxfragsperpacket); |
| static VNET_DEFINE(int, nipq); /* Total # of reass queues */ |
| |
| #define V_ipq VNET(ipq) |
| #define V_maxnipq VNET(maxnipq) |
| #define V_maxfragsperpacket VNET(maxfragsperpacket) |
| #define V_nipq VNET(nipq) |
| |
| VNET_DEFINE(int, ipstealth); |
| |
| struct rwlock in_ifaddr_lock; |
| RW_SYSINIT(in_ifaddr_lock, &in_ifaddr_lock, "in_ifaddr_lock"); |
| |
| /* |
| SYSCTL_VNET_INT(_net_inet_ip, IPCTL_FORWARDING, forwarding, CTLFLAG_RW, |
| &VNET_NAME(ipforwarding), 0, |
| "Enable IP forwarding between interfaces"); |
| |
| SYSCTL_VNET_INT(_net_inet_ip, IPCTL_SENDREDIRECTS, redirect, CTLFLAG_RW, |
| &VNET_NAME(ipsendredirects), 0, |
| "Enable sending IP redirects"); |
| |
| SYSCTL_VNET_INT(_net_inet_ip, IPCTL_DEFTTL, ttl, CTLFLAG_RW, |
| &VNET_NAME(ip_defttl), 0, |
| "Maximum TTL on IP packets"); |
| |
| SYSCTL_VNET_INT(_net_inet_ip, IPCTL_KEEPFAITH, keepfaith, CTLFLAG_RW, |
| &VNET_NAME(ip_keepfaith), 0, |
| "Enable packet capture for FAITH IPv4->IPv6 translater daemon"); |
| |
| SYSCTL_VNET_INT(_net_inet_ip, OID_AUTO, sendsourcequench, CTLFLAG_RW, |
| &VNET_NAME(ip_sendsourcequench), 0, |
| "Enable the transmission of source quench packets"); |
| |
| SYSCTL_VNET_INT(_net_inet_ip, OID_AUTO, random_id, CTLFLAG_RW, |
| &VNET_NAME(ip_do_randomid), 0, |
| "Assign random ip_id values"); |
| */ |
| /* |
| * XXX - Setting ip_checkinterface mostly implements the receive side of |
| * the Strong ES model described in RFC 1122, but since the routing table |
| * and transmit implementation do not implement the Strong ES model, |
| * setting this to 1 results in an odd hybrid. |
| * |
| * XXX - ip_checkinterface currently must be disabled if you use ipnat |
| * to translate the destination address to another local interface. |
| * |
| * XXX - ip_checkinterface must be disabled if you add IP aliases |
| * to the loopback interface instead of the interface where the |
| * packets for those addresses are received. |
| */ |
| /* |
| SYSCTL_VNET_INT(_net_inet_ip, OID_AUTO, check_interface, CTLFLAG_RW, |
| &VNET_NAME(ip_checkinterface), 0, |
| "Verify packet arrives on correct interface"); |
| */ |
| //struct pfil_head inet_pfil_hook; /* Packet filter hooks */ |
| |
| static struct netisr_handler ip_nh = { |
| .nh_name = "ip", |
| .nh_handler = ip_input, |
| .nh_proto = NETISR_IP, |
| .nh_policy = NETISR_POLICY_FLOW, |
| }; |
| |
| extern struct domain inetdomain; |
| extern struct protosw inetsw[]; |
| u_char ip_protox[IPPROTO_MAX]; |
| /* |
| SYSCTL_VNET_STRUCT(_net_inet_ip, IPCTL_STATS, stats, CTLFLAG_RW, |
| &VNET_NAME(ipstat), ipstat, |
| "IP statistics (struct ipstat, netinet/ip_var.h)"); |
| */ |
| static VNET_DEFINE(uma_zone_t, ipq_zone); |
| #define V_ipq_zone VNET(ipq_zone) |
| |
| static struct mtx ipqlock; |
| |
| #define IPQ_LOCK() mtx_lock(&ipqlock) |
| #define IPQ_UNLOCK() mtx_unlock(&ipqlock) |
| #define IPQ_LOCK_INIT() mtx_init(&ipqlock, "ipqlock", NULL, MTX_DEF) |
| #define IPQ_LOCK_ASSERT() mtx_assert(&ipqlock, MA_OWNED) |
| |
| static void maxnipq_update(void); |
| //static void ipq_zone_change(void *); |
| /* |
| SYSCTL_VNET_INT(_net_inet_ip, OID_AUTO, fragpackets, CTLFLAG_RD, |
| &VNET_NAME(nipq), 0, |
| "Current number of IPv4 fragment reassembly queue entries"); |
| |
| SYSCTL_VNET_INT(_net_inet_ip, OID_AUTO, maxfragsperpacket, CTLFLAG_RW, |
| &VNET_NAME(maxfragsperpacket), 0, |
| "Maximum number of IPv4 fragments allowed per packet"); |
| */ |
| struct callout ipport_tick_callout; |
| /* |
| #ifdef IPCTL_DEFMTU |
| SYSCTL_INT(_net_inet_ip, IPCTL_DEFMTU, mtu, CTLFLAG_RW, |
| &ip_mtu, 0, "Default MTU"); |
| #endif |
| |
| #ifdef IPSTEALTH |
| SYSCTL_VNET_INT(_net_inet_ip, OID_AUTO, stealth, CTLFLAG_RW, |
| &VNET_NAME(ipstealth), 0, |
| "IP stealth mode, no TTL decrementation on forwarding"); |
| #endif |
| */ |
| #ifdef FLOWTABLE |
| static VNET_DEFINE(int, ip_output_flowtable_size) = 2048; |
| VNET_DEFINE(struct flowtable *, ip_ft); |
| #define V_ip_output_flowtable_size VNET(ip_output_flowtable_size) |
| /* |
| SYSCTL_VNET_INT(_net_inet_ip, OID_AUTO, output_flowtable_size, CTLFLAG_RDTUN, |
| &VNET_NAME(ip_output_flowtable_size), 2048, |
| "number of entries in the per-cpu output flow caches"); |
| */ |
| #endif |
| |
| VNET_DEFINE(int, fw_one_pass) = 1; |
| |
| static void ip_freef(struct ipqhead *, struct ipq *); |
| |
| /* |
| * Kernel module interface for updating ipstat. The argument is an index |
| * into ipstat treated as an array of u_long. While this encodes the general |
| * layout of ipstat into the caller, it doesn't encode its location, so that |
| * future changes to add, for example, per-CPU stats support won't cause |
| * binary compatibility problems for kernel modules. |
| */ |
| void |
| kmod_ipstat_inc(int statnum) |
| { |
| |
| (*((u_long *)&V_ipstat + statnum))++; |
| } |
| |
| void |
| kmod_ipstat_dec(int statnum) |
| { |
| |
| (*((u_long *)&V_ipstat + statnum))--; |
| } |
| /* |
| 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, 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, 0, 0, sysctl_netinet_intr_queue_drops, "I", |
| "Number of packets dropped from the IP input queue"); |
| */ |
| /* |
| * IP initialization: fill in IP protocol switch table. |
| * All protocols not implemented in kernel go to raw IP protocol handler. |
| */ |
| void |
| ip_init(void) |
| { |
| struct protosw *pr; |
| int i; |
| |
| V_ip_id = time_second & 0xffff; |
| |
| TAILQ_INIT(&V_in_ifaddrhead); |
| V_in_ifaddrhashtbl = hashinit(INADDR_NHASH, M_IFADDR, &V_in_ifaddrhmask); |
| |
| /* Initialize IP reassembly queue. */ |
| for (i = 0; i < IPREASS_NHASH; i++) |
| TAILQ_INIT(&V_ipq[i]); |
| V_maxnipq = nmbclusters / 32; |
| V_maxfragsperpacket = 16; |
| V_ipq_zone = uma_zcreate("ipq", sizeof(struct ipq), NULL, NULL, NULL, |
| NULL, UMA_ALIGN_PTR, 0); |
| maxnipq_update(); |
| |
| #ifdef FLOWTABLE |
| TUNABLE_INT_FETCH("net.inet.ip.output_flowtable_size", |
| &V_ip_output_flowtable_size); |
| V_ip_ft = flowtable_alloc(V_ip_output_flowtable_size, FL_PCPU); |
| #endif |
| |
| /* Skip initialization of globals for non-default instances. */ |
| if (!IS_DEFAULT_VNET(curvnet)) |
| return; |
| |
| pr = pffindproto(PF_INET, IPPROTO_RAW, SOCK_RAW); |
| if (pr == NULL) |
| panic("ip_init: PF_INET not found"); |
| |
| /* Initialize the entire ip_protox[] array to IPPROTO_RAW. */ |
| for (i = 0; i < IPPROTO_MAX; i++) |
| ip_protox[i] = pr - inetsw; |
| /* |
| * Cycle through IP protocols and put them into the appropriate place |
| * in ip_protox[]. |
| */ |
| 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) { |
| /* Be careful to only index valid IP protocols. */ |
| if (pr->pr_protocol < IPPROTO_MAX) |
| ip_protox[pr->pr_protocol] = pr - inetsw; |
| } |
| |
| /* Initialize packet filter hooks. */ |
| /* inet_pfil_hook.ph_type = PFIL_TYPE_AF; |
| inet_pfil_hook.ph_af = AF_INET; |
| if ((i = pfil_head_register(&inet_pfil_hook)) != 0) |
| printf("%s: WARNING: unable to register pfil hook, " |
| "error %d\n", __func__, i); |
| */ |
| /* Start ipport_tick. */ |
| callout_init(&ipport_tick_callout, CALLOUT_MPSAFE); |
| callout_reset(&ipport_tick_callout, 1, ipport_tick, NULL); |
| // EVENTHANDLER_REGISTER(shutdown_pre_sync, ip_fini, NULL, |
| // SHUTDOWN_PRI_DEFAULT); |
| // EVENTHANDLER_REGISTER(nmbclusters_change, ipq_zone_change, |
| // NULL, EVENTHANDLER_PRI_ANY); |
| |
| /* Initialize various other remaining things. */ |
| IPQ_LOCK_INIT(); |
| netisr_register(&ip_nh); |
| } |
| |
| void |
| ip_fini(void *xtp) |
| { |
| |
| callout_stop(&ipport_tick_callout); |
| } |
| |
| /* |
| * 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 checkif, hlen = 0; |
| u_short sum; |
| int dchg = 0; /* dest changed after fw */ |
| struct in_addr odst; /* original dst address */ |
| |
| M_ASSERTPKTHDR(m); |
| |
| if (m->m_flags & M_FASTFWD_OURS) { |
| /* |
| * Firewall or NAT changed destination to local. |
| * We expect ip_len and ip_off to be in host byte order. |
| */ |
| 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; |
| goto ours; |
| } |
| |
| IPSTAT_INC(ips_total); |
| |
| |
| if (m->m_pkthdr.len < sizeof(struct ip)) |
| goto tooshort; |
| |
| if (m->m_len < sizeof (struct ip) && |
| (m = m_pullup(m, sizeof (struct ip))) == NULL) { |
| IPSTAT_INC(ips_toosmall); |
| return; |
| } |
| ip = mtod(m, struct ip *); |
| |
| if (ip->ip_v != IPVERSION) { |
| IPSTAT_INC(ips_badvers); |
| goto bad; |
| } |
| |
| hlen = ip->ip_hl << 2; |
| if (hlen < sizeof(struct ip)) { /* minimum header length */ |
| IPSTAT_INC(ips_badhlen); |
| goto bad; |
| } |
| if (hlen > m->m_len) { |
| if ((m = m_pullup(m, hlen)) == NULL) { |
| IPSTAT_INC(ips_badhlen); |
| return; |
| } |
| ip = mtod(m, struct ip *); |
| } |
| |
| /* 127/8 must not appear on wire - RFC1122 */ |
| ifp = m->m_pkthdr.rcvif; |
| 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 (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); |
| } |
| } |
| #ifndef NIF_CSUM_ENABLE |
| sum = 0; |
| #endif |
| if (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 |
| |
| /* |
| * Convert fields to host representation. |
| */ |
| ip->ip_len = ntohs(ip->ip_len); |
| if (ip->ip_len < hlen) { |
| IPSTAT_INC(ips_badlen); |
| goto bad; |
| } |
| ip->ip_off = ntohs(ip->ip_off); |
| |
| /* |
| * 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 (m->m_pkthdr.len < ip->ip_len) { |
| tooshort: |
| IPSTAT_INC(ips_tooshort); |
| goto bad; |
| } |
| if (m->m_pkthdr.len > ip->ip_len) { |
| if (m->m_len == m->m_pkthdr.len) { |
| m->m_len = ip->ip_len; |
| m->m_pkthdr.len = ip->ip_len; |
| } else |
| m_adj(m, ip->ip_len - m->m_pkthdr.len); |
| } |
| #ifdef IPSEC |
| /* |
| * Bypass packet filtering for packets from a tunnel (gif). |
| */ |
| if (ip_ipsec_filtertunnel(m)) |
| goto passin; |
| #endif /* IPSEC */ |
| |
| /* |
| * 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(&inet_pfil_hook)) |
| // goto passin; |
| |
| odst = ip->ip_dst; |
| // if (pfil_run_hooks(&inet_pfil_hook, &m, ifp, PFIL_IN, NULL) != 0) |
| // return; |
| if (m == NULL) /* consumed by filter */ |
| return; |
| |
| ip = mtod(m, struct ip *); |
| dchg = (odst.s_addr != ip->ip_dst.s_addr); |
| ifp = m->m_pkthdr.rcvif; |
| |
| #ifdef IPFIREWALL_FORWARD |
| if (m->m_flags & M_FASTFWD_OURS) { |
| m->m_flags &= ~M_FASTFWD_OURS; |
| goto ours; |
| } |
| if ((dchg = (m_tag_find(m, PACKET_TAG_IPFORWARD, NULL) != NULL)) != 0) { |
| /* |
| * Directly ship the packet on. This allows forwarding |
| * packets originally destined to us to some other directly |
| * connected host. |
| */ |
| ip_forward(m, dchg); |
| return; |
| } |
| #endif /* IPFIREWALL_FORWARD */ |
| |
| //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 (V_rsvp_on && ip->ip_p==IPPROTO_RSVP) |
| 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 (TAILQ_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) if IP forwarding is disabled and the packet |
| * is not locally generated and the packet is not subject to |
| * 'ipfw fwd'. |
| * |
| * XXX - Checking also should be disabled if the destination |
| * address is ipnat'ed to a different interface. |
| * |
| * XXX - Checking is incompatible with IP aliases added |
| * to the loopback interface instead of the interface where |
| * the packets are received. |
| * |
| * XXX - This is the case for carp vhost IPs as well so we |
| * insert a workaround. If the packet got here, we already |
| * checked with carp_iamatch() and carp_forus(). |
| */ |
| checkif = V_ip_checkinterface && (V_ipforwarding == 0) && |
| ifp != NULL && ((ifp->if_flags & IFF_LOOPBACK) == 0) && |
| #ifdef DEV_CARP |
| !ifp->if_carp && |
| #endif |
| (dchg == 0); |
| |
| /* |
| * Check for exact addresses in the hash bucket. |
| */ |
| IN_IFADDR_RLOCK(); |
| LIST_FOREACH(ia, INADDR_HASH(ip->ip_dst.s_addr), ia_hash) { |
| /* |
| * If the address matches, verify that the packet |
| * arrived via the correct interface if checking is |
| * enabled. |
| */ |
| if (IA_SIN(ia)->sin_addr.s_addr == ip->ip_dst.s_addr && |
| (!checkif || ia->ia_ifp == ifp)) { |
| ifa_ref(&ia->ia_ifa); |
| IN_IFADDR_RUNLOCK(); |
| goto ours; |
| } |
| } |
| IN_IFADDR_RUNLOCK(); |
| |
| /* |
| * 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 != NULL && ifp->if_flags & IFF_BROADCAST) { |
| IF_ADDR_LOCK(ifp); |
| TAILQ_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) { |
| ifa_ref(ifa); |
| IF_ADDR_UNLOCK(ifp); |
| goto ours; |
| } |
| if (ia->ia_netbroadcast.s_addr == ip->ip_dst.s_addr) { |
| ifa_ref(ifa); |
| IF_ADDR_UNLOCK(ifp); |
| goto ours; |
| } |
| #ifdef BOOTP_COMPAT |
| if (IA_SIN(ia)->sin_addr.s_addr == INADDR_ANY) { |
| ifa_ref(ifa); |
| IF_ADDR_UNLOCK(ifp); |
| goto ours; |
| } |
| #endif |
| } |
| IF_ADDR_UNLOCK(ifp); |
| ia = NULL; |
| } |
| /* RFC 3927 2.7: Do not forward datagrams for 169.254.0.0/16. */ |
| if (IN_LINKLOCAL(ntohl(ip->ip_dst.s_addr))) { |
| IPSTAT_INC(ips_cantforward); |
| m_freem(m); |
| return; |
| } |
| if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr))) { |
| if (V_ip_mrouter) { |
| /* |
| * 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; |
| |
| /* |
| * FAITH(Firewall Aided Internet Translator) |
| */ |
| if (ifp && ifp->if_type == IFT_FAITH) { |
| if (V_ip_keepfaith) { |
| if (ip->ip_p == IPPROTO_TCP || ip->ip_p == IPPROTO_ICMP) |
| goto ours; |
| } |
| m_freem(m); |
| return; |
| } |
| |
| /* |
| * Not for us; forward if possible and desirable. |
| */ |
| if (V_ipforwarding == 0) { |
| IPSTAT_INC(ips_cantforward); |
| m_freem(m); |
| } else { |
| #ifdef IPSEC |
| if (ip_ipsec_fwd(m)) |
| goto bad; |
| #endif /* IPSEC */ |
| 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)) { |
| if (ia != NULL) |
| ifa_free(&ia->ia_ifa); |
| return; |
| } |
| #endif /* IPSTEALTH */ |
| |
| /* Count the packet in the ip address stats */ |
| if (ia != NULL) { |
| ia->ia_ifa.if_ipackets++; |
| ia->ia_ifa.if_ibytes += m->m_pkthdr.len; |
| ifa_free(&ia->ia_ifa); |
| } |
| |
| /* |
| * Attempt reassembly; if it succeeds, proceed. |
| * ip_reass() will return a different mbuf. |
| */ |
| if (ip->ip_off & (IP_MF | IP_OFFMASK)) { |
| 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; |
| } |
| |
| /* |
| * Further protocols expect the packet length to be w/o the |
| * IP header. |
| */ |
| ip->ip_len -= hlen; |
| |
| #ifdef IPSEC |
| /* |
| * enforce IPsec policy checking if we are seeing last header. |
| * note that we do not visit this with protocols with pcb layer |
| * code - like udp/tcp/raw ip. |
| */ |
| if (ip_ipsec_input(m)) |
| goto bad; |
| #endif /* IPSEC */ |
| |
| /* |
| * Switch out to protocol's input routine. |
| */ |
| IPSTAT_INC(ips_delivered); |
| |
| (*inetsw[ip_protox[ip->ip_p]].pr_input)(m, hlen); |
| return; |
| bad: |
| m_freem(m); |
| } |
| |
| /* |
| * 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 |
| maxnipq_update(void) |
| { |
| |
| /* |
| * -1 for unlimited allocation. |
| */ |
| if (V_maxnipq < 0) |
| uma_zone_set_max(V_ipq_zone, 0); |
| /* |
| * Positive number for specific bound. |
| */ |
| if (V_maxnipq > 0) |
| uma_zone_set_max(V_ipq_zone, V_maxnipq); |
| /* |
| * Zero specifies no further fragment queue allocation -- set the |
| * bound very low, but rely on implementation elsewhere to actually |
| * prevent allocation and reclaim current queues. |
| */ |
| if (V_maxnipq == 0) |
| uma_zone_set_max(V_ipq_zone, 1); |
| } |
| |
| #if 0 |
| static void |
| ipq_zone_change(void *tag) |
| { |
| |
| if (V_maxnipq > 0 && V_maxnipq < (nmbclusters / 32)) { |
| V_maxnipq = nmbclusters / 32; |
| maxnipq_update(); |
| } |
| } |
| #endif |
| |
| /* |
| static int |
| sysctl_maxnipq(SYSCTL_HANDLER_ARGS) |
| { |
| int error, i; |
| |
| i = V_maxnipq; |
| error = sysctl_handle_int(oidp, &i, 0, req); |
| if (error || !req->newptr) |
| return (error); |
| |
| */ /* |
| * XXXRW: Might be a good idea to sanity check the argument and place |
| * an extreme upper bound. |
| */ |
| /* if (i < -1) |
| return (EINVAL); |
| V_maxnipq = i; |
| maxnipq_update(); |
| return (0); |
| } |
| |
| SYSCTL_PROC(_net_inet_ip, OID_AUTO, maxfragpackets, CTLTYPE_INT|CTLFLAG_RW, |
| NULL, 0, sysctl_maxnipq, "I", |
| "Maximum number of IPv4 fragment reassembly queue entries"); |
| */ |
| /* |
| * 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. |
| */ |
| struct mbuf * |
| ip_reass(struct mbuf *m) |
| { |
| struct ip *ip; |
| struct mbuf *p, *q, *nq, *t; |
| struct ipq *fp = NULL; |
| struct ipqhead *head; |
| int i, hlen, next; |
| u_int8_t ecn, ecn0; |
| u_short hash; |
| |
| /* If maxnipq or maxfragsperpacket are 0, never accept fragments. */ |
| if (V_maxnipq == 0 || V_maxfragsperpacket == 0) { |
| IPSTAT_INC(ips_fragments); |
| IPSTAT_INC(ips_fragdropped); |
| m_freem(m); |
| return (NULL); |
| } |
| |
| ip = mtod(m, struct ip *); |
| hlen = ip->ip_hl << 2; |
| |
| hash = IPREASS_HASH(ip->ip_src.s_addr, ip->ip_id); |
| head = &V_ipq[hash]; |
| IPQ_LOCK(); |
| |
| /* |
| * 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) |
| goto found; |
| |
| fp = NULL; |
| |
| /* |
| * Attempt to trim the number of allocated fragment queues if it |
| * exceeds the administrative limit. |
| */ |
| if ((V_nipq > V_maxnipq) && (V_maxnipq > 0)) { |
| /* |
| * drop something from the tail of the current queue |
| * before proceeding further |
| */ |
| struct ipq *q = TAILQ_LAST(head, ipqhead); |
| if (q == NULL) { /* gak */ |
| for (i = 0; i < IPREASS_NHASH; i++) { |
| struct ipq *r = TAILQ_LAST(&V_ipq[i], ipqhead); |
| if (r) { |
| IPSTAT_ADD(ips_fragtimeout, |
| r->ipq_nfrags); |
| ip_freef(&V_ipq[i], r); |
| break; |
| } |
| } |
| } else { |
| IPSTAT_ADD(ips_fragtimeout, q->ipq_nfrags); |
| ip_freef(head, q); |
| } |
| } |
| |
| found: |
| /* |
| * Adjust ip_len to not reflect header, |
| * convert offset of this to bytes. |
| */ |
| ip->ip_len -= hlen; |
| if (ip->ip_off & IP_MF) { |
| /* |
| * Make sure that fragments have a data length |
| * that's a non-zero multiple of 8 bytes. |
| */ |
| if (ip->ip_len == 0 || (ip->ip_len & 0x7) != 0) { |
| IPSTAT_INC(ips_toosmall); /* XXX */ |
| goto dropfrag; |
| } |
| m->m_flags |= M_FRAG; |
| } else |
| m->m_flags &= ~M_FRAG; |
| ip->ip_off <<= 3; |
| |
| |
| /* |
| * Attempt reassembly; if it succeeds, proceed. |
| * ip_reass() will return a different mbuf. |
| */ |
| IPSTAT_INC(ips_fragments); |
| m->m_pkthdr.header = ip; |
| |
| /* Previous ip_reass() started here. */ |
| /* |
| * 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 = uma_zalloc(V_ipq_zone, M_NOWAIT); |
| 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_nipq++; |
| fp->ipq_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; |
| m->m_nextpkt = NULL; |
| goto done; |
| } else { |
| fp->ipq_nfrags++; |
| #ifdef MAC |
| mac_ipq_update(m, fp); |
| #endif |
| } |
| |
| #define GETIP(m) ((struct ip*)((m)->m_pkthdr.header)) |
| |
| /* |
| * 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 (GETIP(q)->ip_off > 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 the preceding |
| * segment, then it's checksum is invalidated. |
| */ |
| if (p) { |
| i = GETIP(p)->ip_off + GETIP(p)->ip_len - ip->ip_off; |
| if (i > 0) { |
| if (i >= ip->ip_len) |
| goto dropfrag; |
| m_adj(m, i); |
| m->m_pkthdr.csum_flags = 0; |
| ip->ip_off += i; |
| 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 && ip->ip_off + ip->ip_len > GETIP(q)->ip_off; |
| q = nq) { |
| i = (ip->ip_off + ip->ip_len) - GETIP(q)->ip_off; |
| if (i < GETIP(q)->ip_len) { |
| GETIP(q)->ip_len -= i; |
| 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--; |
| 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 (GETIP(q)->ip_off != next) { |
| if (fp->ipq_nfrags > V_maxfragsperpacket) { |
| IPSTAT_ADD(ips_fragdropped, fp->ipq_nfrags); |
| ip_freef(head, fp); |
| } |
| goto done; |
| } |
| next += GETIP(q)->ip_len; |
| } |
| /* Make sure the last packet didn't have the IP_MF flag */ |
| if (p->m_flags & M_FRAG) { |
| if (fp->ipq_nfrags > V_maxfragsperpacket) { |
| IPSTAT_ADD(ips_fragdropped, fp->ipq_nfrags); |
| ip_freef(head, 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); |
| IPSTAT_ADD(ips_fragdropped, fp->ipq_nfrags); |
| ip_freef(head, fp); |
| goto done; |
| } |
| |
| /* |
| * Concatenate fragments. |
| */ |
| m = q; |
| t = m->m_next; |
| CHECK_SPLIT_LINKCNT(m, t, "ip_reass"); |
| 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_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. |
| */ |
| m->m_pkthdr.csum_data = |
| (m->m_pkthdr.csum_data & 0xffff) + (m->m_pkthdr.csum_data >> 16); |
| #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 = (ip->ip_hl << 2) + next; |
| ip->ip_src = fp->ipq_src; |
| ip->ip_dst = fp->ipq_dst; |
| TAILQ_REMOVE(head, fp, ipq_list); |
| V_nipq--; |
| 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); |
| IPSTAT_INC(ips_reassembled); |
| IPQ_UNLOCK(); |
| return (m); |
| |
| dropfrag: |
| IPSTAT_INC(ips_fragdropped); |
| if (fp != NULL) |
| fp->ipq_nfrags--; |
| m_freem(m); |
| done: |
| IPQ_UNLOCK(); |
| return (NULL); |
| |
| #undef GETIP |
| } |
| |
| /* |
| * Free a fragment reassembly header and all |
| * associated datagrams. |
| */ |
| static void |
| ip_freef(struct ipqhead *fhp, struct ipq *fp) |
| { |
| struct mbuf *q; |
| |
| IPQ_LOCK_ASSERT(); |
| |
| while (fp->ipq_frags) { |
| q = fp->ipq_frags; |
| fp->ipq_frags = q->m_nextpkt; |
| m_freem(q); |
| } |
| TAILQ_REMOVE(fhp, fp, ipq_list); |
| uma_zfree(V_ipq_zone, fp); |
| V_nipq--; |
| } |
| |
| /* |
| * IP timer processing; |
| * if a timer expires on a reassembly |
| * queue, discard it. |
| */ |
| void |
| ip_slowtimo(void) |
| { |
| VNET_ITERATOR_DECL(vnet_iter); |
| struct ipq *fp; |
| int i; |
| |
| VNET_LIST_RLOCK_NOSLEEP(); |
| IPQ_LOCK(); |
| VNET_FOREACH(vnet_iter) { |
| CURVNET_SET(vnet_iter); |
| for (i = 0; i < IPREASS_NHASH; i++) { |
| for(fp = TAILQ_FIRST(&V_ipq[i]); fp;) { |
| struct ipq *fpp; |
| |
| fpp = fp; |
| fp = TAILQ_NEXT(fp, ipq_list); |
| if(--fpp->ipq_ttl == 0) { |
| IPSTAT_ADD(ips_fragtimeout, |
| fpp->ipq_nfrags); |
| ip_freef(&V_ipq[i], fpp); |
| } |
| } |
| } |
| /* |
| * If we are over the maximum number of fragments |
| * (due to the limit being lowered), drain off |
| * enough to get down to the new limit. |
| */ |
| if (V_maxnipq >= 0 && V_nipq > V_maxnipq) { |
| for (i = 0; i < IPREASS_NHASH; i++) { |
| while (V_nipq > V_maxnipq && |
| !TAILQ_EMPTY(&V_ipq[i])) { |
| IPSTAT_ADD(ips_fragdropped, |
| TAILQ_FIRST(&V_ipq[i])->ipq_nfrags); |
| ip_freef(&V_ipq[i], |
| TAILQ_FIRST(&V_ipq[i])); |
| } |
| } |
| } |
| CURVNET_RESTORE(); |
| } |
| IPQ_UNLOCK(); |
| VNET_LIST_RUNLOCK_NOSLEEP(); |
| } |
| |
| /* |
| * Drain off all datagram fragments. |
| */ |
| void |
| ip_drain(void) |
| { |
| VNET_ITERATOR_DECL(vnet_iter); |
| int i; |
| |
| VNET_LIST_RLOCK_NOSLEEP(); |
| IPQ_LOCK(); |
| VNET_FOREACH(vnet_iter) { |
| CURVNET_SET(vnet_iter); |
| for (i = 0; i < IPREASS_NHASH; i++) { |
| while(!TAILQ_EMPTY(&V_ipq[i])) { |
| IPSTAT_ADD(ips_fragdropped, |
| TAILQ_FIRST(&V_ipq[i])->ipq_nfrags); |
| ip_freef(&V_ipq[i], TAILQ_FIRST(&V_ipq[i])); |
| } |
| } |
| CURVNET_RESTORE(); |
| } |
| IPQ_UNLOCK(); |
| VNET_LIST_RUNLOCK_NOSLEEP(); |
| in_rtqdrain(); |
| } |
| |
| /* |
| * The protocol to be inserted into ip_protox[] must be already registered |
| * in inetsw[], either statically or through pf_proto_register(). |
| */ |
| int |
| ipproto_register(u_char ipproto) |
| { |
| struct protosw *pr; |
| |
| /* Sanity checks. */ |
| if (ipproto == 0) |
| return (EPROTONOSUPPORT); |
| |
| /* |
| * The protocol slot must not be occupied by another protocol |
| * already. An index pointing to IPPROTO_RAW is unused. |
| */ |
| pr = pffindproto(PF_INET, IPPROTO_RAW, SOCK_RAW); |
| if (pr == NULL) |
| return (EPFNOSUPPORT); |
| if (ip_protox[ipproto] != pr - inetsw) /* IPPROTO_RAW */ |
| return (EEXIST); |
| |
| /* Find the protocol position in inetsw[] and set the index. */ |
| 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) { |
| /* Be careful to only index valid IP protocols. */ |
| if (pr->pr_protocol < IPPROTO_MAX) { |
| ip_protox[pr->pr_protocol] = pr - inetsw; |
| return (0); |
| } else |
| return (EINVAL); |
| } |
| } |
| return (EPROTONOSUPPORT); |
| } |
| |
| int |
| ipproto_unregister(u_char ipproto) |
| { |
| struct protosw *pr; |
| |
| /* Sanity checks. */ |
| if (ipproto == 0) |
| return (EPROTONOSUPPORT); |
| |
| /* Check if the protocol was indeed registered. */ |
| pr = pffindproto(PF_INET, IPPROTO_RAW, SOCK_RAW); |
| if (pr == NULL) |
| return (EPFNOSUPPORT); |
| if (ip_protox[ipproto] == pr - inetsw) /* IPPROTO_RAW */ |
| return (ENOENT); |
| |
| /* Reset the protocol slot to IPPROTO_RAW. */ |
| ip_protox[ipproto] = pr - inetsw; |
| return (0); |
| } |
| |
| /* |
| * Given address of next destination (final or next hop), return (referenced) |
| * internet address info of interface to be used to get there. |
| */ |
| struct in_ifaddr * |
| ip_rtaddr(struct in_addr dst, u_int fibnum) |
| { |
| struct route sro; |
| struct sockaddr_in *sin; |
| struct in_ifaddr *ia; |
| |
| bzero(&sro, sizeof(sro)); |
| sin = (struct sockaddr_in *)&sro.ro_dst; |
| sin->sin_family = AF_INET; |
| sin->sin_len = sizeof(*sin); |
| sin->sin_addr = dst; |
| in_rtalloc_ign(&sro, 0, fibnum); |
| |
| if (sro.ro_rt == NULL) |
| return (NULL); |
| |
| ia = ifatoia(sro.ro_rt->rt_ifa); |
| ifa_ref(&ia->ia_ifa); |
| RTFREE(sro.ro_rt); |
| return (ia); |
| } |
| |
| 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 in_addr dest; |
| struct route ro; |
| int error, type = 0, code = 0, mtu = 0; |
| |
| if (m->m_flags & (M_BCAST|M_MCAST) || in_canforward(ip->ip_dst) == 0) { |
| IPSTAT_INC(ips_cantforward); |
| m_freem(m); |
| return; |
| } |
| #ifdef IPSTEALTH |
| if (!V_ipstealth) { |
| #endif |
| if (ip->ip_ttl <= IPTTLDEC) { |
| icmp_error(m, ICMP_TIMXCEED, ICMP_TIMXCEED_INTRANS, |
| 0, 0); |
| return; |
| } |
| #ifdef IPSTEALTH |
| } |
| #endif |
| |
| ia = ip_rtaddr(ip->ip_dst, M_GETFIB(m)); |
| #ifndef IPSEC |
| /* |
| * 'ia' may be NULL if there is no route for this destination. |
| * In case of IPsec, Don't discard it just yet, but pass it to |
| * ip_output in case of outgoing IPsec policy. |
| */ |
| if (!srcrt && ia == NULL) { |
| icmp_error(m, ICMP_UNREACH, ICMP_UNREACH_HOST, 0, 0); |
| return; |
| } |
| #endif |
| |
| /* |
| * 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_copy() 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(). |
| */ |
| MGETHDR(mcopy, M_DONTWAIT, m->m_type); |
| if (mcopy != NULL && !m_dup_pkthdr(mcopy, m, M_DONTWAIT)) { |
| /* |
| * 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(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) { |
| #endif |
| ip->ip_ttl -= IPTTLDEC; |
| #ifdef IPSTEALTH |
| } |
| #endif |
| |
| /* |
| * 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 sockaddr_in *sin; |
| struct rtentry *rt; |
| |
| 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; |
| in_rtalloc_ign(&ro, 0, M_GETFIB(m)); |
| |
| rt = ro.ro_rt; |
| |
| if (rt && (rt->rt_flags & (RTF_DYNAMIC|RTF_MODIFIED)) == 0 && |
| satosin(rt_key(rt))->sin_addr.s_addr != 0) { |
| #define RTA(rt) ((struct in_ifaddr *)(rt->rt_ifa)) |
| u_long src = ntohl(ip->ip_src.s_addr); |
| |
| if (RTA(rt) && |
| (src & RTA(rt)->ia_subnetmask) == RTA(rt)->ia_subnet) { |
| if (rt->rt_flags & RTF_GATEWAY) |
| dest.s_addr = satosin(rt->rt_gateway)->sin_addr.s_addr; |
| else |
| dest.s_addr = ip->ip_dst.s_addr; |
| /* Router requirements says to only send host redirects */ |
| type = ICMP_REDIRECT; |
| code = ICMP_REDIRECT_HOST; |
| } |
| } |
| if (rt) |
| RTFREE(rt); |
| } |
| |
| /* |
| * Try to cache the route MTU from ip_output so we can consider it for |
| * the ICMP_UNREACH_NEEDFRAG "Next-Hop MTU" field described in RFC1191. |
| */ |
| bzero(&ro, sizeof(ro)); |
| |
| error = ip_output(m, NULL, &ro, IP_FORWARDING, NULL, NULL); |
| |
| if (error == EMSGSIZE && ro.ro_rt) |
| mtu = ro.ro_rt->rt_rmx.rmx_mtu; |
| if (ro.ro_rt) |
| RTFREE(ro.ro_rt); |
| |
| if (error) |
| IPSTAT_INC(ips_cantforward); |
| else { |
| IPSTAT_INC(ips_forward); |
| if (type) |
| IPSTAT_INC(ips_redirectsent); |
| else { |
| if (mcopy) |
| m_freem(mcopy); |
| if (ia != NULL) |
| ifa_free(&ia->ia_ifa); |
| return; |
| } |
| } |
| if (mcopy == NULL) { |
| if (ia != NULL) |
| ifa_free(&ia->ia_ifa); |
| 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; |
| |
| #ifdef IPSEC |
| /* |
| * If IPsec is configured for this path, |
| * override any possibly mtu value set by ip_output. |
| */ |
| mtu = ip_ipsec_mtu(m, mtu); |
| #endif /* IPSEC */ |
| /* |
| * 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(ip->ip_len, 0); |
| } |
| IPSTAT_INC(ips_cantfrag); |
| break; |
| |
| 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 if the underlying interface is rate-limited. |
| * Those who need source quench packets may re-enable them |
| * via the net.inet.ip.sendsourcequench sysctl. |
| */ |
| if (V_ip_sendsourcequench == 0) { |
| m_freem(mcopy); |
| if (ia != NULL) |
| ifa_free(&ia->ia_ifa); |
| return; |
| } else { |
| type = ICMP_SOURCEQUENCH; |
| code = 0; |
| } |
| break; |
| |
| case EACCES: /* ipfw denied packet */ |
| m_freem(mcopy); |
| if (ia != NULL) |
| ifa_free(&ia->ia_ifa); |
| return; |
| } |
| if (ia != NULL) |
| ifa_free(&ia->ia_ifa); |
| icmp_error(mcopy, type, code, dest.s_addr, mtu); |
| } |
| |
| #if 0 |
| void |
| ip_savecontrol(struct inpcb *inp, struct mbuf **mp, struct ip *ip, |
| struct mbuf *m) |
| { |
| |
| if (inp->inp_socket->so_options & (SO_BINTIME | SO_TIMESTAMP)) { |
| struct bintime bt; |
| |
| bintime(&bt); |
| if (inp->inp_socket->so_options & SO_BINTIME) { |
| *mp = sbcreatecontrol((caddr_t) &bt, sizeof(bt), |
| SCM_BINTIME, SOL_SOCKET); |
| if (*mp) |
| mp = &(*mp)->m_next; |
| } |
| if (inp->inp_socket->so_options & SO_TIMESTAMP) { |
| struct timeval tv; |
| |
| bintime2timeval(&bt, &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; |
| } |
| if (inp->inp_flags & INP_RECVTTL) { |
| *mp = sbcreatecontrol((caddr_t) &ip->ip_ttl, |
| sizeof(u_char), IP_RECVTTL, IPPROTO_IP); |
| 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((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 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)) |
| && ( ifp->if_index && (ifp->if_index <= V_if_index))) { |
| 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((caddr_t) sdl2, sdl2->sdl_len, |
| IP_RECVIF, IPPROTO_IP); |
| if (*mp) |
| mp = &(*mp)->m_next; |
| } |
| } |
| #endif //0 |
| |
| /* |
| * 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. |
| */ |
| 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; |
| } |
| |
| void |
| rsvp_input(struct mbuf *m, int off) /* XXX must fixup manually */ |
| { |
| |
| if (rsvp_input_p) { /* call the real one if loaded */ |
| rsvp_input_p(m, off); |
| return; |
| } |
| |
| /* 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; |
| } |
| |
| if (V_ip_rsvpd != NULL) { |
| rip_input(m, off); |
| return; |
| } |
| /* Drop the packet */ |
| m_freem(m); |
| } |