The Design and Implementation of the FreeBSD Operating System, Second Edition
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FreeBSD/Linux Kernel Cross Reference
sys/netinet/ip_input.c

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    1 /*-
    2  * SPDX-License-Identifier: BSD-3-Clause
    3  *
    4  * Copyright (c) 1982, 1986, 1988, 1993
    5  *      The Regents of the University of California.  All rights reserved.
    6  *
    7  * Redistribution and use in source and binary forms, with or without
    8  * modification, are permitted provided that the following conditions
    9  * are met:
   10  * 1. Redistributions of source code must retain the above copyright
   11  *    notice, this list of conditions and the following disclaimer.
   12  * 2. Redistributions in binary form must reproduce the above copyright
   13  *    notice, this list of conditions and the following disclaimer in the
   14  *    documentation and/or other materials provided with the distribution.
   15  * 3. Neither the name of the University nor the names of its contributors
   16  *    may be used to endorse or promote products derived from this software
   17  *    without specific prior written permission.
   18  *
   19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
   20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
   23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
   24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
   25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
   26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
   28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
   29  * SUCH DAMAGE.
   30  *
   31  *      @(#)ip_input.c  8.2 (Berkeley) 1/4/94
   32  */
   33 
   34 #include <sys/cdefs.h>
   35 __FBSDID("$FreeBSD: releng/12.0/sys/netinet/ip_input.c 337736 2018-08-14 07:54:14Z ae $");
   36 
   37 #include "opt_bootp.h"
   38 #include "opt_ipstealth.h"
   39 #include "opt_ipsec.h"
   40 #include "opt_route.h"
   41 #include "opt_rss.h"
   42 
   43 #include <sys/param.h>
   44 #include <sys/systm.h>
   45 #include <sys/hhook.h>
   46 #include <sys/mbuf.h>
   47 #include <sys/malloc.h>
   48 #include <sys/domain.h>
   49 #include <sys/protosw.h>
   50 #include <sys/socket.h>
   51 #include <sys/time.h>
   52 #include <sys/kernel.h>
   53 #include <sys/lock.h>
   54 #include <sys/rmlock.h>
   55 #include <sys/rwlock.h>
   56 #include <sys/sdt.h>
   57 #include <sys/syslog.h>
   58 #include <sys/sysctl.h>
   59 
   60 #include <net/pfil.h>
   61 #include <net/if.h>
   62 #include <net/if_types.h>
   63 #include <net/if_var.h>
   64 #include <net/if_dl.h>
   65 #include <net/route.h>
   66 #include <net/netisr.h>
   67 #include <net/rss_config.h>
   68 #include <net/vnet.h>
   69 
   70 #include <netinet/in.h>
   71 #include <netinet/in_kdtrace.h>
   72 #include <netinet/in_systm.h>
   73 #include <netinet/in_var.h>
   74 #include <netinet/ip.h>
   75 #include <netinet/in_pcb.h>
   76 #include <netinet/ip_var.h>
   77 #include <netinet/ip_fw.h>
   78 #include <netinet/ip_icmp.h>
   79 #include <netinet/ip_options.h>
   80 #include <machine/in_cksum.h>
   81 #include <netinet/ip_carp.h>
   82 #include <netinet/in_rss.h>
   83 
   84 #include <netipsec/ipsec_support.h>
   85 
   86 #include <sys/socketvar.h>
   87 
   88 #include <security/mac/mac_framework.h>
   89 
   90 #ifdef CTASSERT
   91 CTASSERT(sizeof(struct ip) == 20);
   92 #endif
   93 
   94 /* IP reassembly functions are defined in ip_reass.c. */
   95 extern void ipreass_init(void);
   96 extern void ipreass_drain(void);
   97 extern void ipreass_slowtimo(void);
   98 #ifdef VIMAGE
   99 extern void ipreass_destroy(void);
  100 #endif
  101 
  102 struct rmlock in_ifaddr_lock;
  103 RM_SYSINIT(in_ifaddr_lock, &in_ifaddr_lock, "in_ifaddr_lock");
  104 
  105 VNET_DEFINE(int, rsvp_on);
  106 
  107 VNET_DEFINE(int, ipforwarding);
  108 SYSCTL_INT(_net_inet_ip, IPCTL_FORWARDING, forwarding, CTLFLAG_VNET | CTLFLAG_RW,
  109     &VNET_NAME(ipforwarding), 0,
  110     "Enable IP forwarding between interfaces");
  111 
  112 VNET_DEFINE_STATIC(int, ipsendredirects) = 1;   /* XXX */
  113 #define V_ipsendredirects       VNET(ipsendredirects)
  114 SYSCTL_INT(_net_inet_ip, IPCTL_SENDREDIRECTS, redirect, CTLFLAG_VNET | CTLFLAG_RW,
  115     &VNET_NAME(ipsendredirects), 0,
  116     "Enable sending IP redirects");
  117 
  118 /*
  119  * XXX - Setting ip_checkinterface mostly implements the receive side of
  120  * the Strong ES model described in RFC 1122, but since the routing table
  121  * and transmit implementation do not implement the Strong ES model,
  122  * setting this to 1 results in an odd hybrid.
  123  *
  124  * XXX - ip_checkinterface currently must be disabled if you use ipnat
  125  * to translate the destination address to another local interface.
  126  *
  127  * XXX - ip_checkinterface must be disabled if you add IP aliases
  128  * to the loopback interface instead of the interface where the
  129  * packets for those addresses are received.
  130  */
  131 VNET_DEFINE_STATIC(int, ip_checkinterface);
  132 #define V_ip_checkinterface     VNET(ip_checkinterface)
  133 SYSCTL_INT(_net_inet_ip, OID_AUTO, check_interface, CTLFLAG_VNET | CTLFLAG_RW,
  134     &VNET_NAME(ip_checkinterface), 0,
  135     "Verify packet arrives on correct interface");
  136 
  137 VNET_DEFINE(struct pfil_head, inet_pfil_hook);  /* Packet filter hooks */
  138 
  139 static struct netisr_handler ip_nh = {
  140         .nh_name = "ip",
  141         .nh_handler = ip_input,
  142         .nh_proto = NETISR_IP,
  143 #ifdef  RSS
  144         .nh_m2cpuid = rss_soft_m2cpuid_v4,
  145         .nh_policy = NETISR_POLICY_CPU,
  146         .nh_dispatch = NETISR_DISPATCH_HYBRID,
  147 #else
  148         .nh_policy = NETISR_POLICY_FLOW,
  149 #endif
  150 };
  151 
  152 #ifdef  RSS
  153 /*
  154  * Directly dispatched frames are currently assumed
  155  * to have a flowid already calculated.
  156  *
  157  * It should likely have something that assert it
  158  * actually has valid flow details.
  159  */
  160 static struct netisr_handler ip_direct_nh = {
  161         .nh_name = "ip_direct",
  162         .nh_handler = ip_direct_input,
  163         .nh_proto = NETISR_IP_DIRECT,
  164         .nh_m2cpuid = rss_soft_m2cpuid_v4,
  165         .nh_policy = NETISR_POLICY_CPU,
  166         .nh_dispatch = NETISR_DISPATCH_HYBRID,
  167 };
  168 #endif
  169 
  170 extern  struct domain inetdomain;
  171 extern  struct protosw inetsw[];
  172 u_char  ip_protox[IPPROTO_MAX];
  173 VNET_DEFINE(struct in_ifaddrhead, in_ifaddrhead);  /* first inet address */
  174 VNET_DEFINE(struct in_ifaddrhashhead *, in_ifaddrhashtbl); /* inet addr hash table  */
  175 VNET_DEFINE(u_long, in_ifaddrhmask);            /* mask for hash table */
  176 
  177 #ifdef IPCTL_DEFMTU
  178 SYSCTL_INT(_net_inet_ip, IPCTL_DEFMTU, mtu, CTLFLAG_RW,
  179     &ip_mtu, 0, "Default MTU");
  180 #endif
  181 
  182 #ifdef IPSTEALTH
  183 VNET_DEFINE(int, ipstealth);
  184 SYSCTL_INT(_net_inet_ip, OID_AUTO, stealth, CTLFLAG_VNET | CTLFLAG_RW,
  185     &VNET_NAME(ipstealth), 0,
  186     "IP stealth mode, no TTL decrementation on forwarding");
  187 #endif
  188 
  189 /*
  190  * IP statistics are stored in the "array" of counter(9)s.
  191  */
  192 VNET_PCPUSTAT_DEFINE(struct ipstat, ipstat);
  193 VNET_PCPUSTAT_SYSINIT(ipstat);
  194 SYSCTL_VNET_PCPUSTAT(_net_inet_ip, IPCTL_STATS, stats, struct ipstat, ipstat,
  195     "IP statistics (struct ipstat, netinet/ip_var.h)");
  196 
  197 #ifdef VIMAGE
  198 VNET_PCPUSTAT_SYSUNINIT(ipstat);
  199 #endif /* VIMAGE */
  200 
  201 /*
  202  * Kernel module interface for updating ipstat.  The argument is an index
  203  * into ipstat treated as an array.
  204  */
  205 void
  206 kmod_ipstat_inc(int statnum)
  207 {
  208 
  209         counter_u64_add(VNET(ipstat)[statnum], 1);
  210 }
  211 
  212 void
  213 kmod_ipstat_dec(int statnum)
  214 {
  215 
  216         counter_u64_add(VNET(ipstat)[statnum], -1);
  217 }
  218 
  219 static int
  220 sysctl_netinet_intr_queue_maxlen(SYSCTL_HANDLER_ARGS)
  221 {
  222         int error, qlimit;
  223 
  224         netisr_getqlimit(&ip_nh, &qlimit);
  225         error = sysctl_handle_int(oidp, &qlimit, 0, req);
  226         if (error || !req->newptr)
  227                 return (error);
  228         if (qlimit < 1)
  229                 return (EINVAL);
  230         return (netisr_setqlimit(&ip_nh, qlimit));
  231 }
  232 SYSCTL_PROC(_net_inet_ip, IPCTL_INTRQMAXLEN, intr_queue_maxlen,
  233     CTLTYPE_INT|CTLFLAG_RW, 0, 0, sysctl_netinet_intr_queue_maxlen, "I",
  234     "Maximum size of the IP input queue");
  235 
  236 static int
  237 sysctl_netinet_intr_queue_drops(SYSCTL_HANDLER_ARGS)
  238 {
  239         u_int64_t qdrops_long;
  240         int error, qdrops;
  241 
  242         netisr_getqdrops(&ip_nh, &qdrops_long);
  243         qdrops = qdrops_long;
  244         error = sysctl_handle_int(oidp, &qdrops, 0, req);
  245         if (error || !req->newptr)
  246                 return (error);
  247         if (qdrops != 0)
  248                 return (EINVAL);
  249         netisr_clearqdrops(&ip_nh);
  250         return (0);
  251 }
  252 
  253 SYSCTL_PROC(_net_inet_ip, IPCTL_INTRQDROPS, intr_queue_drops,
  254     CTLTYPE_INT|CTLFLAG_RD, 0, 0, sysctl_netinet_intr_queue_drops, "I",
  255     "Number of packets dropped from the IP input queue");
  256 
  257 #ifdef  RSS
  258 static int
  259 sysctl_netinet_intr_direct_queue_maxlen(SYSCTL_HANDLER_ARGS)
  260 {
  261         int error, qlimit;
  262 
  263         netisr_getqlimit(&ip_direct_nh, &qlimit);
  264         error = sysctl_handle_int(oidp, &qlimit, 0, req);
  265         if (error || !req->newptr)
  266                 return (error);
  267         if (qlimit < 1)
  268                 return (EINVAL);
  269         return (netisr_setqlimit(&ip_direct_nh, qlimit));
  270 }
  271 SYSCTL_PROC(_net_inet_ip, IPCTL_INTRDQMAXLEN, intr_direct_queue_maxlen,
  272     CTLTYPE_INT|CTLFLAG_RW, 0, 0, sysctl_netinet_intr_direct_queue_maxlen,
  273     "I", "Maximum size of the IP direct input queue");
  274 
  275 static int
  276 sysctl_netinet_intr_direct_queue_drops(SYSCTL_HANDLER_ARGS)
  277 {
  278         u_int64_t qdrops_long;
  279         int error, qdrops;
  280 
  281         netisr_getqdrops(&ip_direct_nh, &qdrops_long);
  282         qdrops = qdrops_long;
  283         error = sysctl_handle_int(oidp, &qdrops, 0, req);
  284         if (error || !req->newptr)
  285                 return (error);
  286         if (qdrops != 0)
  287                 return (EINVAL);
  288         netisr_clearqdrops(&ip_direct_nh);
  289         return (0);
  290 }
  291 
  292 SYSCTL_PROC(_net_inet_ip, IPCTL_INTRDQDROPS, intr_direct_queue_drops,
  293     CTLTYPE_INT|CTLFLAG_RD, 0, 0, sysctl_netinet_intr_direct_queue_drops, "I",
  294     "Number of packets dropped from the IP direct input queue");
  295 #endif  /* RSS */
  296 
  297 /*
  298  * IP initialization: fill in IP protocol switch table.
  299  * All protocols not implemented in kernel go to raw IP protocol handler.
  300  */
  301 void
  302 ip_init(void)
  303 {
  304         struct protosw *pr;
  305         int i;
  306 
  307         CK_STAILQ_INIT(&V_in_ifaddrhead);
  308         V_in_ifaddrhashtbl = hashinit(INADDR_NHASH, M_IFADDR, &V_in_ifaddrhmask);
  309 
  310         /* Initialize IP reassembly queue. */
  311         ipreass_init();
  312 
  313         /* Initialize packet filter hooks. */
  314         V_inet_pfil_hook.ph_type = PFIL_TYPE_AF;
  315         V_inet_pfil_hook.ph_af = AF_INET;
  316         if ((i = pfil_head_register(&V_inet_pfil_hook)) != 0)
  317                 printf("%s: WARNING: unable to register pfil hook, "
  318                         "error %d\n", __func__, i);
  319 
  320         if (hhook_head_register(HHOOK_TYPE_IPSEC_IN, AF_INET,
  321             &V_ipsec_hhh_in[HHOOK_IPSEC_INET],
  322             HHOOK_WAITOK | HHOOK_HEADISINVNET) != 0)
  323                 printf("%s: WARNING: unable to register input helper hook\n",
  324                     __func__);
  325         if (hhook_head_register(HHOOK_TYPE_IPSEC_OUT, AF_INET,
  326             &V_ipsec_hhh_out[HHOOK_IPSEC_INET],
  327             HHOOK_WAITOK | HHOOK_HEADISINVNET) != 0)
  328                 printf("%s: WARNING: unable to register output helper hook\n",
  329                     __func__);
  330 
  331         /* Skip initialization of globals for non-default instances. */
  332 #ifdef VIMAGE
  333         if (!IS_DEFAULT_VNET(curvnet)) {
  334                 netisr_register_vnet(&ip_nh);
  335 #ifdef  RSS
  336                 netisr_register_vnet(&ip_direct_nh);
  337 #endif
  338                 return;
  339         }
  340 #endif
  341 
  342         pr = pffindproto(PF_INET, IPPROTO_RAW, SOCK_RAW);
  343         if (pr == NULL)
  344                 panic("ip_init: PF_INET not found");
  345 
  346         /* Initialize the entire ip_protox[] array to IPPROTO_RAW. */
  347         for (i = 0; i < IPPROTO_MAX; i++)
  348                 ip_protox[i] = pr - inetsw;
  349         /*
  350          * Cycle through IP protocols and put them into the appropriate place
  351          * in ip_protox[].
  352          */
  353         for (pr = inetdomain.dom_protosw;
  354             pr < inetdomain.dom_protoswNPROTOSW; pr++)
  355                 if (pr->pr_domain->dom_family == PF_INET &&
  356                     pr->pr_protocol && pr->pr_protocol != IPPROTO_RAW) {
  357                         /* Be careful to only index valid IP protocols. */
  358                         if (pr->pr_protocol < IPPROTO_MAX)
  359                                 ip_protox[pr->pr_protocol] = pr - inetsw;
  360                 }
  361 
  362         netisr_register(&ip_nh);
  363 #ifdef  RSS
  364         netisr_register(&ip_direct_nh);
  365 #endif
  366 }
  367 
  368 #ifdef VIMAGE
  369 static void
  370 ip_destroy(void *unused __unused)
  371 {
  372         struct ifnet *ifp;
  373         int error;
  374 
  375 #ifdef  RSS
  376         netisr_unregister_vnet(&ip_direct_nh);
  377 #endif
  378         netisr_unregister_vnet(&ip_nh);
  379 
  380         if ((error = pfil_head_unregister(&V_inet_pfil_hook)) != 0)
  381                 printf("%s: WARNING: unable to unregister pfil hook, "
  382                     "error %d\n", __func__, error);
  383 
  384         error = hhook_head_deregister(V_ipsec_hhh_in[HHOOK_IPSEC_INET]);
  385         if (error != 0) {
  386                 printf("%s: WARNING: unable to deregister input helper hook "
  387                     "type HHOOK_TYPE_IPSEC_IN, id HHOOK_IPSEC_INET: "
  388                     "error %d returned\n", __func__, error);
  389         }
  390         error = hhook_head_deregister(V_ipsec_hhh_out[HHOOK_IPSEC_INET]);
  391         if (error != 0) {
  392                 printf("%s: WARNING: unable to deregister output helper hook "
  393                     "type HHOOK_TYPE_IPSEC_OUT, id HHOOK_IPSEC_INET: "
  394                     "error %d returned\n", __func__, error);
  395         }
  396 
  397         /* Remove the IPv4 addresses from all interfaces. */
  398         in_ifscrub_all();
  399 
  400         /* Make sure the IPv4 routes are gone as well. */
  401         IFNET_RLOCK();
  402         CK_STAILQ_FOREACH(ifp, &V_ifnet, if_link)
  403                 rt_flushifroutes_af(ifp, AF_INET);
  404         IFNET_RUNLOCK();
  405 
  406         /* Destroy IP reassembly queue. */
  407         ipreass_destroy();
  408 
  409         /* Cleanup in_ifaddr hash table; should be empty. */
  410         hashdestroy(V_in_ifaddrhashtbl, M_IFADDR, V_in_ifaddrhmask);
  411 }
  412 
  413 VNET_SYSUNINIT(ip, SI_SUB_PROTO_DOMAIN, SI_ORDER_THIRD, ip_destroy, NULL);
  414 #endif
  415 
  416 #ifdef  RSS
  417 /*
  418  * IP direct input routine.
  419  *
  420  * This is called when reinjecting completed fragments where
  421  * all of the previous checking and book-keeping has been done.
  422  */
  423 void
  424 ip_direct_input(struct mbuf *m)
  425 {
  426         struct ip *ip;
  427         int hlen;
  428 
  429         ip = mtod(m, struct ip *);
  430         hlen = ip->ip_hl << 2;
  431 
  432 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
  433         if (IPSEC_ENABLED(ipv4)) {
  434                 if (IPSEC_INPUT(ipv4, m, hlen, ip->ip_p) != 0)
  435                         return;
  436         }
  437 #endif /* IPSEC */
  438         IPSTAT_INC(ips_delivered);
  439         (*inetsw[ip_protox[ip->ip_p]].pr_input)(&m, &hlen, ip->ip_p);
  440         return;
  441 }
  442 #endif
  443 
  444 /*
  445  * Ip input routine.  Checksum and byte swap header.  If fragmented
  446  * try to reassemble.  Process options.  Pass to next level.
  447  */
  448 void
  449 ip_input(struct mbuf *m)
  450 {
  451         struct ip *ip = NULL;
  452         struct in_ifaddr *ia = NULL;
  453         struct ifaddr *ifa;
  454         struct ifnet *ifp;
  455         int    checkif, hlen = 0;
  456         uint16_t sum, ip_len;
  457         int dchg = 0;                           /* dest changed after fw */
  458         struct in_addr odst;                    /* original dst address */
  459 
  460         M_ASSERTPKTHDR(m);
  461 
  462         if (m->m_flags & M_FASTFWD_OURS) {
  463                 m->m_flags &= ~M_FASTFWD_OURS;
  464                 /* Set up some basics that will be used later. */
  465                 ip = mtod(m, struct ip *);
  466                 hlen = ip->ip_hl << 2;
  467                 ip_len = ntohs(ip->ip_len);
  468                 goto ours;
  469         }
  470 
  471         IPSTAT_INC(ips_total);
  472 
  473         if (m->m_pkthdr.len < sizeof(struct ip))
  474                 goto tooshort;
  475 
  476         if (m->m_len < sizeof (struct ip) &&
  477             (m = m_pullup(m, sizeof (struct ip))) == NULL) {
  478                 IPSTAT_INC(ips_toosmall);
  479                 return;
  480         }
  481         ip = mtod(m, struct ip *);
  482 
  483         if (ip->ip_v != IPVERSION) {
  484                 IPSTAT_INC(ips_badvers);
  485                 goto bad;
  486         }
  487 
  488         hlen = ip->ip_hl << 2;
  489         if (hlen < sizeof(struct ip)) { /* minimum header length */
  490                 IPSTAT_INC(ips_badhlen);
  491                 goto bad;
  492         }
  493         if (hlen > m->m_len) {
  494                 if ((m = m_pullup(m, hlen)) == NULL) {
  495                         IPSTAT_INC(ips_badhlen);
  496                         return;
  497                 }
  498                 ip = mtod(m, struct ip *);
  499         }
  500 
  501         IP_PROBE(receive, NULL, NULL, ip, m->m_pkthdr.rcvif, ip, NULL);
  502 
  503         /* 127/8 must not appear on wire - RFC1122 */
  504         ifp = m->m_pkthdr.rcvif;
  505         if ((ntohl(ip->ip_dst.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET ||
  506             (ntohl(ip->ip_src.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET) {
  507                 if ((ifp->if_flags & IFF_LOOPBACK) == 0) {
  508                         IPSTAT_INC(ips_badaddr);
  509                         goto bad;
  510                 }
  511         }
  512 
  513         if (m->m_pkthdr.csum_flags & CSUM_IP_CHECKED) {
  514                 sum = !(m->m_pkthdr.csum_flags & CSUM_IP_VALID);
  515         } else {
  516                 if (hlen == sizeof(struct ip)) {
  517                         sum = in_cksum_hdr(ip);
  518                 } else {
  519                         sum = in_cksum(m, hlen);
  520                 }
  521         }
  522         if (sum) {
  523                 IPSTAT_INC(ips_badsum);
  524                 goto bad;
  525         }
  526 
  527 #ifdef ALTQ
  528         if (altq_input != NULL && (*altq_input)(m, AF_INET) == 0)
  529                 /* packet is dropped by traffic conditioner */
  530                 return;
  531 #endif
  532 
  533         ip_len = ntohs(ip->ip_len);
  534         if (ip_len < hlen) {
  535                 IPSTAT_INC(ips_badlen);
  536                 goto bad;
  537         }
  538 
  539         /*
  540          * Check that the amount of data in the buffers
  541          * is as at least much as the IP header would have us expect.
  542          * Trim mbufs if longer than we expect.
  543          * Drop packet if shorter than we expect.
  544          */
  545         if (m->m_pkthdr.len < ip_len) {
  546 tooshort:
  547                 IPSTAT_INC(ips_tooshort);
  548                 goto bad;
  549         }
  550         if (m->m_pkthdr.len > ip_len) {
  551                 if (m->m_len == m->m_pkthdr.len) {
  552                         m->m_len = ip_len;
  553                         m->m_pkthdr.len = ip_len;
  554                 } else
  555                         m_adj(m, ip_len - m->m_pkthdr.len);
  556         }
  557 
  558         /*
  559          * Try to forward the packet, but if we fail continue.
  560          * ip_tryforward() does not generate redirects, so fall
  561          * through to normal processing if redirects are required.
  562          * ip_tryforward() does inbound and outbound packet firewall
  563          * processing. If firewall has decided that destination becomes
  564          * our local address, it sets M_FASTFWD_OURS flag. In this
  565          * case skip another inbound firewall processing and update
  566          * ip pointer.
  567          */
  568         if (V_ipforwarding != 0 && V_ipsendredirects == 0
  569 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
  570             && (!IPSEC_ENABLED(ipv4) ||
  571             IPSEC_CAPS(ipv4, m, IPSEC_CAP_OPERABLE) == 0)
  572 #endif
  573             ) {
  574                 if ((m = ip_tryforward(m)) == NULL)
  575                         return;
  576                 if (m->m_flags & M_FASTFWD_OURS) {
  577                         m->m_flags &= ~M_FASTFWD_OURS;
  578                         ip = mtod(m, struct ip *);
  579                         goto ours;
  580                 }
  581         }
  582 
  583 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
  584         /*
  585          * Bypass packet filtering for packets previously handled by IPsec.
  586          */
  587         if (IPSEC_ENABLED(ipv4) &&
  588             IPSEC_CAPS(ipv4, m, IPSEC_CAP_BYPASS_FILTER) != 0)
  589                         goto passin;
  590 #endif
  591 
  592         /*
  593          * Run through list of hooks for input packets.
  594          *
  595          * NB: Beware of the destination address changing (e.g.
  596          *     by NAT rewriting).  When this happens, tell
  597          *     ip_forward to do the right thing.
  598          */
  599 
  600         /* Jump over all PFIL processing if hooks are not active. */
  601         if (!PFIL_HOOKED(&V_inet_pfil_hook))
  602                 goto passin;
  603 
  604         odst = ip->ip_dst;
  605         if (pfil_run_hooks(&V_inet_pfil_hook, &m, ifp, PFIL_IN, 0, NULL) != 0)
  606                 return;
  607         if (m == NULL)                  /* consumed by filter */
  608                 return;
  609 
  610         ip = mtod(m, struct ip *);
  611         dchg = (odst.s_addr != ip->ip_dst.s_addr);
  612         ifp = m->m_pkthdr.rcvif;
  613 
  614         if (m->m_flags & M_FASTFWD_OURS) {
  615                 m->m_flags &= ~M_FASTFWD_OURS;
  616                 goto ours;
  617         }
  618         if (m->m_flags & M_IP_NEXTHOP) {
  619                 if (m_tag_find(m, PACKET_TAG_IPFORWARD, NULL) != NULL) {
  620                         /*
  621                          * Directly ship the packet on.  This allows
  622                          * forwarding packets originally destined to us
  623                          * to some other directly connected host.
  624                          */
  625                         ip_forward(m, 1);
  626                         return;
  627                 }
  628         }
  629 passin:
  630 
  631         /*
  632          * Process options and, if not destined for us,
  633          * ship it on.  ip_dooptions returns 1 when an
  634          * error was detected (causing an icmp message
  635          * to be sent and the original packet to be freed).
  636          */
  637         if (hlen > sizeof (struct ip) && ip_dooptions(m, 0))
  638                 return;
  639 
  640         /* greedy RSVP, snatches any PATH packet of the RSVP protocol and no
  641          * matter if it is destined to another node, or whether it is 
  642          * a multicast one, RSVP wants it! and prevents it from being forwarded
  643          * anywhere else. Also checks if the rsvp daemon is running before
  644          * grabbing the packet.
  645          */
  646         if (V_rsvp_on && ip->ip_p==IPPROTO_RSVP) 
  647                 goto ours;
  648 
  649         /*
  650          * Check our list of addresses, to see if the packet is for us.
  651          * If we don't have any addresses, assume any unicast packet
  652          * we receive might be for us (and let the upper layers deal
  653          * with it).
  654          */
  655         if (CK_STAILQ_EMPTY(&V_in_ifaddrhead) &&
  656             (m->m_flags & (M_MCAST|M_BCAST)) == 0)
  657                 goto ours;
  658 
  659         /*
  660          * Enable a consistency check between the destination address
  661          * and the arrival interface for a unicast packet (the RFC 1122
  662          * strong ES model) if IP forwarding is disabled and the packet
  663          * is not locally generated and the packet is not subject to
  664          * 'ipfw fwd'.
  665          *
  666          * XXX - Checking also should be disabled if the destination
  667          * address is ipnat'ed to a different interface.
  668          *
  669          * XXX - Checking is incompatible with IP aliases added
  670          * to the loopback interface instead of the interface where
  671          * the packets are received.
  672          *
  673          * XXX - This is the case for carp vhost IPs as well so we
  674          * insert a workaround. If the packet got here, we already
  675          * checked with carp_iamatch() and carp_forus().
  676          */
  677         checkif = V_ip_checkinterface && (V_ipforwarding == 0) && 
  678             ifp != NULL && ((ifp->if_flags & IFF_LOOPBACK) == 0) &&
  679             ifp->if_carp == NULL && (dchg == 0);
  680 
  681         /*
  682          * Check for exact addresses in the hash bucket.
  683          */
  684         /* IN_IFADDR_RLOCK(); */
  685         LIST_FOREACH(ia, INADDR_HASH(ip->ip_dst.s_addr), ia_hash) {
  686                 /*
  687                  * If the address matches, verify that the packet
  688                  * arrived via the correct interface if checking is
  689                  * enabled.
  690                  */
  691                 if (IA_SIN(ia)->sin_addr.s_addr == ip->ip_dst.s_addr && 
  692                     (!checkif || ia->ia_ifp == ifp)) {
  693                         counter_u64_add(ia->ia_ifa.ifa_ipackets, 1);
  694                         counter_u64_add(ia->ia_ifa.ifa_ibytes,
  695                             m->m_pkthdr.len);
  696                         /* IN_IFADDR_RUNLOCK(); */
  697                         goto ours;
  698                 }
  699         }
  700         /* IN_IFADDR_RUNLOCK(); */
  701 
  702         /*
  703          * Check for broadcast addresses.
  704          *
  705          * Only accept broadcast packets that arrive via the matching
  706          * interface.  Reception of forwarded directed broadcasts would
  707          * be handled via ip_forward() and ether_output() with the loopback
  708          * into the stack for SIMPLEX interfaces handled by ether_output().
  709          */
  710         if (ifp != NULL && ifp->if_flags & IFF_BROADCAST) {
  711                 IF_ADDR_RLOCK(ifp);
  712                 CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
  713                         if (ifa->ifa_addr->sa_family != AF_INET)
  714                                 continue;
  715                         ia = ifatoia(ifa);
  716                         if (satosin(&ia->ia_broadaddr)->sin_addr.s_addr ==
  717                             ip->ip_dst.s_addr) {
  718                                 counter_u64_add(ia->ia_ifa.ifa_ipackets, 1);
  719                                 counter_u64_add(ia->ia_ifa.ifa_ibytes,
  720                                     m->m_pkthdr.len);
  721                                 IF_ADDR_RUNLOCK(ifp);
  722                                 goto ours;
  723                         }
  724 #ifdef BOOTP_COMPAT
  725                         if (IA_SIN(ia)->sin_addr.s_addr == INADDR_ANY) {
  726                                 counter_u64_add(ia->ia_ifa.ifa_ipackets, 1);
  727                                 counter_u64_add(ia->ia_ifa.ifa_ibytes,
  728                                     m->m_pkthdr.len);
  729                                 IF_ADDR_RUNLOCK(ifp);
  730                                 goto ours;
  731                         }
  732 #endif
  733                 }
  734                 IF_ADDR_RUNLOCK(ifp);
  735                 ia = NULL;
  736         }
  737         /* RFC 3927 2.7: Do not forward datagrams for 169.254.0.0/16. */
  738         if (IN_LINKLOCAL(ntohl(ip->ip_dst.s_addr))) {
  739                 IPSTAT_INC(ips_cantforward);
  740                 m_freem(m);
  741                 return;
  742         }
  743         if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr))) {
  744                 if (V_ip_mrouter) {
  745                         /*
  746                          * If we are acting as a multicast router, all
  747                          * incoming multicast packets are passed to the
  748                          * kernel-level multicast forwarding function.
  749                          * The packet is returned (relatively) intact; if
  750                          * ip_mforward() returns a non-zero value, the packet
  751                          * must be discarded, else it may be accepted below.
  752                          */
  753                         if (ip_mforward && ip_mforward(ip, ifp, m, 0) != 0) {
  754                                 IPSTAT_INC(ips_cantforward);
  755                                 m_freem(m);
  756                                 return;
  757                         }
  758 
  759                         /*
  760                          * The process-level routing daemon needs to receive
  761                          * all multicast IGMP packets, whether or not this
  762                          * host belongs to their destination groups.
  763                          */
  764                         if (ip->ip_p == IPPROTO_IGMP)
  765                                 goto ours;
  766                         IPSTAT_INC(ips_forward);
  767                 }
  768                 /*
  769                  * Assume the packet is for us, to avoid prematurely taking
  770                  * a lock on the in_multi hash. Protocols must perform
  771                  * their own filtering and update statistics accordingly.
  772                  */
  773                 goto ours;
  774         }
  775         if (ip->ip_dst.s_addr == (u_long)INADDR_BROADCAST)
  776                 goto ours;
  777         if (ip->ip_dst.s_addr == INADDR_ANY)
  778                 goto ours;
  779 
  780         /*
  781          * Not for us; forward if possible and desirable.
  782          */
  783         if (V_ipforwarding == 0) {
  784                 IPSTAT_INC(ips_cantforward);
  785                 m_freem(m);
  786         } else {
  787                 ip_forward(m, dchg);
  788         }
  789         return;
  790 
  791 ours:
  792 #ifdef IPSTEALTH
  793         /*
  794          * IPSTEALTH: Process non-routing options only
  795          * if the packet is destined for us.
  796          */
  797         if (V_ipstealth && hlen > sizeof (struct ip) && ip_dooptions(m, 1))
  798                 return;
  799 #endif /* IPSTEALTH */
  800 
  801         /*
  802          * Attempt reassembly; if it succeeds, proceed.
  803          * ip_reass() will return a different mbuf.
  804          */
  805         if (ip->ip_off & htons(IP_MF | IP_OFFMASK)) {
  806                 /* XXXGL: shouldn't we save & set m_flags? */
  807                 m = ip_reass(m);
  808                 if (m == NULL)
  809                         return;
  810                 ip = mtod(m, struct ip *);
  811                 /* Get the header length of the reassembled packet */
  812                 hlen = ip->ip_hl << 2;
  813         }
  814 
  815 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
  816         if (IPSEC_ENABLED(ipv4)) {
  817                 if (IPSEC_INPUT(ipv4, m, hlen, ip->ip_p) != 0)
  818                         return;
  819         }
  820 #endif /* IPSEC */
  821 
  822         /*
  823          * Switch out to protocol's input routine.
  824          */
  825         IPSTAT_INC(ips_delivered);
  826 
  827         (*inetsw[ip_protox[ip->ip_p]].pr_input)(&m, &hlen, ip->ip_p);
  828         return;
  829 bad:
  830         m_freem(m);
  831 }
  832 
  833 /*
  834  * IP timer processing;
  835  * if a timer expires on a reassembly
  836  * queue, discard it.
  837  */
  838 void
  839 ip_slowtimo(void)
  840 {
  841         VNET_ITERATOR_DECL(vnet_iter);
  842 
  843         VNET_LIST_RLOCK_NOSLEEP();
  844         VNET_FOREACH(vnet_iter) {
  845                 CURVNET_SET(vnet_iter);
  846                 ipreass_slowtimo();
  847                 CURVNET_RESTORE();
  848         }
  849         VNET_LIST_RUNLOCK_NOSLEEP();
  850 }
  851 
  852 void
  853 ip_drain(void)
  854 {
  855         VNET_ITERATOR_DECL(vnet_iter);
  856 
  857         VNET_LIST_RLOCK_NOSLEEP();
  858         VNET_FOREACH(vnet_iter) {
  859                 CURVNET_SET(vnet_iter);
  860                 ipreass_drain();
  861                 CURVNET_RESTORE();
  862         }
  863         VNET_LIST_RUNLOCK_NOSLEEP();
  864 }
  865 
  866 /*
  867  * The protocol to be inserted into ip_protox[] must be already registered
  868  * in inetsw[], either statically or through pf_proto_register().
  869  */
  870 int
  871 ipproto_register(short ipproto)
  872 {
  873         struct protosw *pr;
  874 
  875         /* Sanity checks. */
  876         if (ipproto <= 0 || ipproto >= IPPROTO_MAX)
  877                 return (EPROTONOSUPPORT);
  878 
  879         /*
  880          * The protocol slot must not be occupied by another protocol
  881          * already.  An index pointing to IPPROTO_RAW is unused.
  882          */
  883         pr = pffindproto(PF_INET, IPPROTO_RAW, SOCK_RAW);
  884         if (pr == NULL)
  885                 return (EPFNOSUPPORT);
  886         if (ip_protox[ipproto] != pr - inetsw)  /* IPPROTO_RAW */
  887                 return (EEXIST);
  888 
  889         /* Find the protocol position in inetsw[] and set the index. */
  890         for (pr = inetdomain.dom_protosw;
  891              pr < inetdomain.dom_protoswNPROTOSW; pr++) {
  892                 if (pr->pr_domain->dom_family == PF_INET &&
  893                     pr->pr_protocol && pr->pr_protocol == ipproto) {
  894                         ip_protox[pr->pr_protocol] = pr - inetsw;
  895                         return (0);
  896                 }
  897         }
  898         return (EPROTONOSUPPORT);
  899 }
  900 
  901 int
  902 ipproto_unregister(short ipproto)
  903 {
  904         struct protosw *pr;
  905 
  906         /* Sanity checks. */
  907         if (ipproto <= 0 || ipproto >= IPPROTO_MAX)
  908                 return (EPROTONOSUPPORT);
  909 
  910         /* Check if the protocol was indeed registered. */
  911         pr = pffindproto(PF_INET, IPPROTO_RAW, SOCK_RAW);
  912         if (pr == NULL)
  913                 return (EPFNOSUPPORT);
  914         if (ip_protox[ipproto] == pr - inetsw)  /* IPPROTO_RAW */
  915                 return (ENOENT);
  916 
  917         /* Reset the protocol slot to IPPROTO_RAW. */
  918         ip_protox[ipproto] = pr - inetsw;
  919         return (0);
  920 }
  921 
  922 u_char inetctlerrmap[PRC_NCMDS] = {
  923         0,              0,              0,              0,
  924         0,              EMSGSIZE,       EHOSTDOWN,      EHOSTUNREACH,
  925         EHOSTUNREACH,   EHOSTUNREACH,   ECONNREFUSED,   ECONNREFUSED,
  926         EMSGSIZE,       EHOSTUNREACH,   0,              0,
  927         0,              0,              EHOSTUNREACH,   0,
  928         ENOPROTOOPT,    ECONNREFUSED
  929 };
  930 
  931 /*
  932  * Forward a packet.  If some error occurs return the sender
  933  * an icmp packet.  Note we can't always generate a meaningful
  934  * icmp message because icmp doesn't have a large enough repertoire
  935  * of codes and types.
  936  *
  937  * If not forwarding, just drop the packet.  This could be confusing
  938  * if ipforwarding was zero but some routing protocol was advancing
  939  * us as a gateway to somewhere.  However, we must let the routing
  940  * protocol deal with that.
  941  *
  942  * The srcrt parameter indicates whether the packet is being forwarded
  943  * via a source route.
  944  */
  945 void
  946 ip_forward(struct mbuf *m, int srcrt)
  947 {
  948         struct ip *ip = mtod(m, struct ip *);
  949         struct in_ifaddr *ia;
  950         struct mbuf *mcopy;
  951         struct sockaddr_in *sin;
  952         struct in_addr dest;
  953         struct route ro;
  954         int error, type = 0, code = 0, mtu = 0;
  955 
  956         if (m->m_flags & (M_BCAST|M_MCAST) || in_canforward(ip->ip_dst) == 0) {
  957                 IPSTAT_INC(ips_cantforward);
  958                 m_freem(m);
  959                 return;
  960         }
  961         if (
  962 #ifdef IPSTEALTH
  963             V_ipstealth == 0 &&
  964 #endif
  965             ip->ip_ttl <= IPTTLDEC) {
  966                 icmp_error(m, ICMP_TIMXCEED, ICMP_TIMXCEED_INTRANS, 0, 0);
  967                 return;
  968         }
  969 
  970         bzero(&ro, sizeof(ro));
  971         sin = (struct sockaddr_in *)&ro.ro_dst;
  972         sin->sin_family = AF_INET;
  973         sin->sin_len = sizeof(*sin);
  974         sin->sin_addr = ip->ip_dst;
  975 #ifdef RADIX_MPATH
  976         rtalloc_mpath_fib(&ro,
  977             ntohl(ip->ip_src.s_addr ^ ip->ip_dst.s_addr),
  978             M_GETFIB(m));
  979 #else
  980         in_rtalloc_ign(&ro, 0, M_GETFIB(m));
  981 #endif
  982         NET_EPOCH_ENTER();
  983         if (ro.ro_rt != NULL) {
  984                 ia = ifatoia(ro.ro_rt->rt_ifa);
  985         } else
  986                 ia = NULL;
  987         /*
  988          * Save the IP header and at most 8 bytes of the payload,
  989          * in case we need to generate an ICMP message to the src.
  990          *
  991          * XXX this can be optimized a lot by saving the data in a local
  992          * buffer on the stack (72 bytes at most), and only allocating the
  993          * mbuf if really necessary. The vast majority of the packets
  994          * are forwarded without having to send an ICMP back (either
  995          * because unnecessary, or because rate limited), so we are
  996          * really we are wasting a lot of work here.
  997          *
  998          * We don't use m_copym() because it might return a reference
  999          * to a shared cluster. Both this function and ip_output()
 1000          * assume exclusive access to the IP header in `m', so any
 1001          * data in a cluster may change before we reach icmp_error().
 1002          */
 1003         mcopy = m_gethdr(M_NOWAIT, m->m_type);
 1004         if (mcopy != NULL && !m_dup_pkthdr(mcopy, m, M_NOWAIT)) {
 1005                 /*
 1006                  * It's probably ok if the pkthdr dup fails (because
 1007                  * the deep copy of the tag chain failed), but for now
 1008                  * be conservative and just discard the copy since
 1009                  * code below may some day want the tags.
 1010                  */
 1011                 m_free(mcopy);
 1012                 mcopy = NULL;
 1013         }
 1014         if (mcopy != NULL) {
 1015                 mcopy->m_len = min(ntohs(ip->ip_len), M_TRAILINGSPACE(mcopy));
 1016                 mcopy->m_pkthdr.len = mcopy->m_len;
 1017                 m_copydata(m, 0, mcopy->m_len, mtod(mcopy, caddr_t));
 1018         }
 1019 #ifdef IPSTEALTH
 1020         if (V_ipstealth == 0)
 1021 #endif
 1022                 ip->ip_ttl -= IPTTLDEC;
 1023 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
 1024         if (IPSEC_ENABLED(ipv4)) {
 1025                 if ((error = IPSEC_FORWARD(ipv4, m)) != 0) {
 1026                         /* mbuf consumed by IPsec */
 1027                         m_freem(mcopy);
 1028                         if (error != EINPROGRESS)
 1029                                 IPSTAT_INC(ips_cantforward);
 1030                         goto out;
 1031                 }
 1032                 /* No IPsec processing required */
 1033         }
 1034 #endif /* IPSEC */
 1035         /*
 1036          * If forwarding packet using same interface that it came in on,
 1037          * perhaps should send a redirect to sender to shortcut a hop.
 1038          * Only send redirect if source is sending directly to us,
 1039          * and if packet was not source routed (or has any options).
 1040          * Also, don't send redirect if forwarding using a default route
 1041          * or a route modified by a redirect.
 1042          */
 1043         dest.s_addr = 0;
 1044         if (!srcrt && V_ipsendredirects &&
 1045             ia != NULL && ia->ia_ifp == m->m_pkthdr.rcvif) {
 1046                 struct rtentry *rt;
 1047 
 1048                 rt = ro.ro_rt;
 1049 
 1050                 if (rt && (rt->rt_flags & (RTF_DYNAMIC|RTF_MODIFIED)) == 0 &&
 1051                     satosin(rt_key(rt))->sin_addr.s_addr != 0) {
 1052 #define RTA(rt) ((struct in_ifaddr *)(rt->rt_ifa))
 1053                         u_long src = ntohl(ip->ip_src.s_addr);
 1054 
 1055                         if (RTA(rt) &&
 1056                             (src & RTA(rt)->ia_subnetmask) == RTA(rt)->ia_subnet) {
 1057                                 if (rt->rt_flags & RTF_GATEWAY)
 1058                                         dest.s_addr = satosin(rt->rt_gateway)->sin_addr.s_addr;
 1059                                 else
 1060                                         dest.s_addr = ip->ip_dst.s_addr;
 1061                                 /* Router requirements says to only send host redirects */
 1062                                 type = ICMP_REDIRECT;
 1063                                 code = ICMP_REDIRECT_HOST;
 1064                         }
 1065                 }
 1066         }
 1067 
 1068         error = ip_output(m, NULL, &ro, IP_FORWARDING, NULL, NULL);
 1069 
 1070         if (error == EMSGSIZE && ro.ro_rt)
 1071                 mtu = ro.ro_rt->rt_mtu;
 1072         RO_RTFREE(&ro);
 1073 
 1074         if (error)
 1075                 IPSTAT_INC(ips_cantforward);
 1076         else {
 1077                 IPSTAT_INC(ips_forward);
 1078                 if (type)
 1079                         IPSTAT_INC(ips_redirectsent);
 1080                 else {
 1081                         if (mcopy)
 1082                                 m_freem(mcopy);
 1083                         goto out;
 1084                 }
 1085         }
 1086         if (mcopy == NULL)
 1087                 goto out;
 1088 
 1089 
 1090         switch (error) {
 1091 
 1092         case 0:                         /* forwarded, but need redirect */
 1093                 /* type, code set above */
 1094                 break;
 1095 
 1096         case ENETUNREACH:
 1097         case EHOSTUNREACH:
 1098         case ENETDOWN:
 1099         case EHOSTDOWN:
 1100         default:
 1101                 type = ICMP_UNREACH;
 1102                 code = ICMP_UNREACH_HOST;
 1103                 break;
 1104 
 1105         case EMSGSIZE:
 1106                 type = ICMP_UNREACH;
 1107                 code = ICMP_UNREACH_NEEDFRAG;
 1108                 /*
 1109                  * If the MTU was set before make sure we are below the
 1110                  * interface MTU.
 1111                  * If the MTU wasn't set before use the interface mtu or
 1112                  * fall back to the next smaller mtu step compared to the
 1113                  * current packet size.
 1114                  */
 1115                 if (mtu != 0) {
 1116                         if (ia != NULL)
 1117                                 mtu = min(mtu, ia->ia_ifp->if_mtu);
 1118                 } else {
 1119                         if (ia != NULL)
 1120                                 mtu = ia->ia_ifp->if_mtu;
 1121                         else
 1122                                 mtu = ip_next_mtu(ntohs(ip->ip_len), 0);
 1123                 }
 1124                 IPSTAT_INC(ips_cantfrag);
 1125                 break;
 1126 
 1127         case ENOBUFS:
 1128         case EACCES:                    /* ipfw denied packet */
 1129                 m_freem(mcopy);
 1130                 goto out;
 1131         }
 1132         icmp_error(mcopy, type, code, dest.s_addr, mtu);
 1133  out:
 1134         NET_EPOCH_EXIT();
 1135 }
 1136 
 1137 #define CHECK_SO_CT(sp, ct) \
 1138     (((sp->so_options & SO_TIMESTAMP) && (sp->so_ts_clock == ct)) ? 1 : 0)
 1139 
 1140 void
 1141 ip_savecontrol(struct inpcb *inp, struct mbuf **mp, struct ip *ip,
 1142     struct mbuf *m)
 1143 {
 1144         bool stamped;
 1145 
 1146         stamped = false;
 1147         if ((inp->inp_socket->so_options & SO_BINTIME) ||
 1148             CHECK_SO_CT(inp->inp_socket, SO_TS_BINTIME)) {
 1149                 struct bintime boottimebin, bt;
 1150                 struct timespec ts1;
 1151 
 1152                 if ((m->m_flags & (M_PKTHDR | M_TSTMP)) == (M_PKTHDR |
 1153                     M_TSTMP)) {
 1154                         mbuf_tstmp2timespec(m, &ts1);
 1155                         timespec2bintime(&ts1, &bt);
 1156                         getboottimebin(&boottimebin);
 1157                         bintime_add(&bt, &boottimebin);
 1158                 } else {
 1159                         bintime(&bt);
 1160                 }
 1161                 *mp = sbcreatecontrol((caddr_t)&bt, sizeof(bt),
 1162                     SCM_BINTIME, SOL_SOCKET);
 1163                 if (*mp != NULL) {
 1164                         mp = &(*mp)->m_next;
 1165                         stamped = true;
 1166                 }
 1167         }
 1168         if (CHECK_SO_CT(inp->inp_socket, SO_TS_REALTIME_MICRO)) {
 1169                 struct bintime boottimebin, bt1;
 1170                 struct timespec ts1;;
 1171                 struct timeval tv;
 1172 
 1173                 if ((m->m_flags & (M_PKTHDR | M_TSTMP)) == (M_PKTHDR |
 1174                     M_TSTMP)) {
 1175                         mbuf_tstmp2timespec(m, &ts1);
 1176                         timespec2bintime(&ts1, &bt1);
 1177                         getboottimebin(&boottimebin);
 1178                         bintime_add(&bt1, &boottimebin);
 1179                         bintime2timeval(&bt1, &tv);
 1180                 } else {
 1181                         microtime(&tv);
 1182                 }
 1183                 *mp = sbcreatecontrol((caddr_t)&tv, sizeof(tv),
 1184                     SCM_TIMESTAMP, SOL_SOCKET);
 1185                 if (*mp != NULL) {
 1186                         mp = &(*mp)->m_next;
 1187                         stamped = true;
 1188                 }
 1189         } else if (CHECK_SO_CT(inp->inp_socket, SO_TS_REALTIME)) {
 1190                 struct bintime boottimebin;
 1191                 struct timespec ts, ts1;
 1192 
 1193                 if ((m->m_flags & (M_PKTHDR | M_TSTMP)) == (M_PKTHDR |
 1194                     M_TSTMP)) {
 1195                         mbuf_tstmp2timespec(m, &ts);
 1196                         getboottimebin(&boottimebin);
 1197                         bintime2timespec(&boottimebin, &ts1);
 1198                         timespecadd(&ts, &ts1, &ts);
 1199                 } else {
 1200                         nanotime(&ts);
 1201                 }
 1202                 *mp = sbcreatecontrol((caddr_t)&ts, sizeof(ts),
 1203                     SCM_REALTIME, SOL_SOCKET);
 1204                 if (*mp != NULL) {
 1205                         mp = &(*mp)->m_next;
 1206                         stamped = true;
 1207                 }
 1208         } else if (CHECK_SO_CT(inp->inp_socket, SO_TS_MONOTONIC)) {
 1209                 struct timespec ts;
 1210 
 1211                 if ((m->m_flags & (M_PKTHDR | M_TSTMP)) == (M_PKTHDR |
 1212                     M_TSTMP))
 1213                         mbuf_tstmp2timespec(m, &ts);
 1214                 else
 1215                         nanouptime(&ts);
 1216                 *mp = sbcreatecontrol((caddr_t)&ts, sizeof(ts),
 1217                     SCM_MONOTONIC, SOL_SOCKET);
 1218                 if (*mp != NULL) {
 1219                         mp = &(*mp)->m_next;
 1220                         stamped = true;
 1221                 }
 1222         }
 1223         if (stamped && (m->m_flags & (M_PKTHDR | M_TSTMP)) == (M_PKTHDR |
 1224             M_TSTMP)) {
 1225                 struct sock_timestamp_info sti;
 1226 
 1227                 bzero(&sti, sizeof(sti));
 1228                 sti.st_info_flags = ST_INFO_HW;
 1229                 if ((m->m_flags & M_TSTMP_HPREC) != 0)
 1230                         sti.st_info_flags |= ST_INFO_HW_HPREC;
 1231                 *mp = sbcreatecontrol((caddr_t)&sti, sizeof(sti), SCM_TIME_INFO,
 1232                     SOL_SOCKET);
 1233                 if (*mp != NULL)
 1234                         mp = &(*mp)->m_next;
 1235         }
 1236         if (inp->inp_flags & INP_RECVDSTADDR) {
 1237                 *mp = sbcreatecontrol((caddr_t)&ip->ip_dst,
 1238                     sizeof(struct in_addr), IP_RECVDSTADDR, IPPROTO_IP);
 1239                 if (*mp)
 1240                         mp = &(*mp)->m_next;
 1241         }
 1242         if (inp->inp_flags & INP_RECVTTL) {
 1243                 *mp = sbcreatecontrol((caddr_t)&ip->ip_ttl,
 1244                     sizeof(u_char), IP_RECVTTL, IPPROTO_IP);
 1245                 if (*mp)
 1246                         mp = &(*mp)->m_next;
 1247         }
 1248 #ifdef notyet
 1249         /* XXX
 1250          * Moving these out of udp_input() made them even more broken
 1251          * than they already were.
 1252          */
 1253         /* options were tossed already */
 1254         if (inp->inp_flags & INP_RECVOPTS) {
 1255                 *mp = sbcreatecontrol((caddr_t)opts_deleted_above,
 1256                     sizeof(struct in_addr), IP_RECVOPTS, IPPROTO_IP);
 1257                 if (*mp)
 1258                         mp = &(*mp)->m_next;
 1259         }
 1260         /* ip_srcroute doesn't do what we want here, need to fix */
 1261         if (inp->inp_flags & INP_RECVRETOPTS) {
 1262                 *mp = sbcreatecontrol((caddr_t)ip_srcroute(m),
 1263                     sizeof(struct in_addr), IP_RECVRETOPTS, IPPROTO_IP);
 1264                 if (*mp)
 1265                         mp = &(*mp)->m_next;
 1266         }
 1267 #endif
 1268         if (inp->inp_flags & INP_RECVIF) {
 1269                 struct ifnet *ifp;
 1270                 struct sdlbuf {
 1271                         struct sockaddr_dl sdl;
 1272                         u_char  pad[32];
 1273                 } sdlbuf;
 1274                 struct sockaddr_dl *sdp;
 1275                 struct sockaddr_dl *sdl2 = &sdlbuf.sdl;
 1276 
 1277                 if ((ifp = m->m_pkthdr.rcvif) &&
 1278                     ifp->if_index && ifp->if_index <= V_if_index) {
 1279                         sdp = (struct sockaddr_dl *)ifp->if_addr->ifa_addr;
 1280                         /*
 1281                          * Change our mind and don't try copy.
 1282                          */
 1283                         if (sdp->sdl_family != AF_LINK ||
 1284                             sdp->sdl_len > sizeof(sdlbuf)) {
 1285                                 goto makedummy;
 1286                         }
 1287                         bcopy(sdp, sdl2, sdp->sdl_len);
 1288                 } else {
 1289 makedummy:      
 1290                         sdl2->sdl_len =
 1291                             offsetof(struct sockaddr_dl, sdl_data[0]);
 1292                         sdl2->sdl_family = AF_LINK;
 1293                         sdl2->sdl_index = 0;
 1294                         sdl2->sdl_nlen = sdl2->sdl_alen = sdl2->sdl_slen = 0;
 1295                 }
 1296                 *mp = sbcreatecontrol((caddr_t)sdl2, sdl2->sdl_len,
 1297                     IP_RECVIF, IPPROTO_IP);
 1298                 if (*mp)
 1299                         mp = &(*mp)->m_next;
 1300         }
 1301         if (inp->inp_flags & INP_RECVTOS) {
 1302                 *mp = sbcreatecontrol((caddr_t)&ip->ip_tos,
 1303                     sizeof(u_char), IP_RECVTOS, IPPROTO_IP);
 1304                 if (*mp)
 1305                         mp = &(*mp)->m_next;
 1306         }
 1307 
 1308         if (inp->inp_flags2 & INP_RECVFLOWID) {
 1309                 uint32_t flowid, flow_type;
 1310 
 1311                 flowid = m->m_pkthdr.flowid;
 1312                 flow_type = M_HASHTYPE_GET(m);
 1313 
 1314                 /*
 1315                  * XXX should handle the failure of one or the
 1316                  * other - don't populate both?
 1317                  */
 1318                 *mp = sbcreatecontrol((caddr_t) &flowid,
 1319                     sizeof(uint32_t), IP_FLOWID, IPPROTO_IP);
 1320                 if (*mp)
 1321                         mp = &(*mp)->m_next;
 1322                 *mp = sbcreatecontrol((caddr_t) &flow_type,
 1323                     sizeof(uint32_t), IP_FLOWTYPE, IPPROTO_IP);
 1324                 if (*mp)
 1325                         mp = &(*mp)->m_next;
 1326         }
 1327 
 1328 #ifdef  RSS
 1329         if (inp->inp_flags2 & INP_RECVRSSBUCKETID) {
 1330                 uint32_t flowid, flow_type;
 1331                 uint32_t rss_bucketid;
 1332 
 1333                 flowid = m->m_pkthdr.flowid;
 1334                 flow_type = M_HASHTYPE_GET(m);
 1335 
 1336                 if (rss_hash2bucket(flowid, flow_type, &rss_bucketid) == 0) {
 1337                         *mp = sbcreatecontrol((caddr_t) &rss_bucketid,
 1338                            sizeof(uint32_t), IP_RSSBUCKETID, IPPROTO_IP);
 1339                         if (*mp)
 1340                                 mp = &(*mp)->m_next;
 1341                 }
 1342         }
 1343 #endif
 1344 }
 1345 
 1346 /*
 1347  * XXXRW: Multicast routing code in ip_mroute.c is generally MPSAFE, but the
 1348  * ip_rsvp and ip_rsvp_on variables need to be interlocked with rsvp_on
 1349  * locking.  This code remains in ip_input.c as ip_mroute.c is optionally
 1350  * compiled.
 1351  */
 1352 VNET_DEFINE_STATIC(int, ip_rsvp_on);
 1353 VNET_DEFINE(struct socket *, ip_rsvpd);
 1354 
 1355 #define V_ip_rsvp_on            VNET(ip_rsvp_on)
 1356 
 1357 int
 1358 ip_rsvp_init(struct socket *so)
 1359 {
 1360 
 1361         if (so->so_type != SOCK_RAW ||
 1362             so->so_proto->pr_protocol != IPPROTO_RSVP)
 1363                 return EOPNOTSUPP;
 1364 
 1365         if (V_ip_rsvpd != NULL)
 1366                 return EADDRINUSE;
 1367 
 1368         V_ip_rsvpd = so;
 1369         /*
 1370          * This may seem silly, but we need to be sure we don't over-increment
 1371          * the RSVP counter, in case something slips up.
 1372          */
 1373         if (!V_ip_rsvp_on) {
 1374                 V_ip_rsvp_on = 1;
 1375                 V_rsvp_on++;
 1376         }
 1377 
 1378         return 0;
 1379 }
 1380 
 1381 int
 1382 ip_rsvp_done(void)
 1383 {
 1384 
 1385         V_ip_rsvpd = NULL;
 1386         /*
 1387          * This may seem silly, but we need to be sure we don't over-decrement
 1388          * the RSVP counter, in case something slips up.
 1389          */
 1390         if (V_ip_rsvp_on) {
 1391                 V_ip_rsvp_on = 0;
 1392                 V_rsvp_on--;
 1393         }
 1394         return 0;
 1395 }
 1396 
 1397 int
 1398 rsvp_input(struct mbuf **mp, int *offp, int proto)
 1399 {
 1400         struct mbuf *m;
 1401 
 1402         m = *mp;
 1403         *mp = NULL;
 1404 
 1405         if (rsvp_input_p) { /* call the real one if loaded */
 1406                 *mp = m;
 1407                 rsvp_input_p(mp, offp, proto);
 1408                 return (IPPROTO_DONE);
 1409         }
 1410 
 1411         /* Can still get packets with rsvp_on = 0 if there is a local member
 1412          * of the group to which the RSVP packet is addressed.  But in this
 1413          * case we want to throw the packet away.
 1414          */
 1415         
 1416         if (!V_rsvp_on) {
 1417                 m_freem(m);
 1418                 return (IPPROTO_DONE);
 1419         }
 1420 
 1421         if (V_ip_rsvpd != NULL) { 
 1422                 *mp = m;
 1423                 rip_input(mp, offp, proto);
 1424                 return (IPPROTO_DONE);
 1425         }
 1426         /* Drop the packet */
 1427         m_freem(m);
 1428         return (IPPROTO_DONE);
 1429 }

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