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  * Copyright (c) 1982, 1986, 1988, 1993
    3  *      The Regents of the University of California.  All rights reserved.
    4  *
    5  * Redistribution and use in source and binary forms, with or without
    6  * modification, are permitted provided that the following conditions
    7  * are met:
    8  * 1. Redistributions of source code must retain the above copyright
    9  *    notice, this list of conditions and the following disclaimer.
   10  * 2. Redistributions in binary form must reproduce the above copyright
   11  *    notice, this list of conditions and the following disclaimer in the
   12  *    documentation and/or other materials provided with the distribution.
   13  * 4. Neither the name of the University nor the names of its contributors
   14  *    may be used to endorse or promote products derived from this software
   15  *    without specific prior written permission.
   16  *
   17  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
   18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
   21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
   22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
   23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
   24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
   26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
   27  * SUCH DAMAGE.
   28  *
   29  *      @(#)ip_input.c  8.2 (Berkeley) 1/4/94
   30  */
   31 
   32 #include <sys/cdefs.h>
   33 __FBSDID("$FreeBSD: releng/11.1/sys/netinet/ip_input.c 317083 2017-04-18 09:27:26Z ae $");
   34 
   35 #include "opt_bootp.h"
   36 #include "opt_ipstealth.h"
   37 #include "opt_ipsec.h"
   38 #include "opt_route.h"
   39 #include "opt_rss.h"
   40 
   41 #include <sys/param.h>
   42 #include <sys/systm.h>
   43 #include <sys/hhook.h>
   44 #include <sys/mbuf.h>
   45 #include <sys/malloc.h>
   46 #include <sys/domain.h>
   47 #include <sys/protosw.h>
   48 #include <sys/socket.h>
   49 #include <sys/time.h>
   50 #include <sys/kernel.h>
   51 #include <sys/lock.h>
   52 #include <sys/rmlock.h>
   53 #include <sys/rwlock.h>
   54 #include <sys/sdt.h>
   55 #include <sys/syslog.h>
   56 #include <sys/sysctl.h>
   57 
   58 #include <net/pfil.h>
   59 #include <net/if.h>
   60 #include <net/if_types.h>
   61 #include <net/if_var.h>
   62 #include <net/if_dl.h>
   63 #include <net/route.h>
   64 #include <net/netisr.h>
   65 #include <net/rss_config.h>
   66 #include <net/vnet.h>
   67 
   68 #include <netinet/in.h>
   69 #include <netinet/in_kdtrace.h>
   70 #include <netinet/in_systm.h>
   71 #include <netinet/in_var.h>
   72 #include <netinet/ip.h>
   73 #include <netinet/in_pcb.h>
   74 #include <netinet/ip_var.h>
   75 #include <netinet/ip_fw.h>
   76 #include <netinet/ip_icmp.h>
   77 #include <netinet/ip_options.h>
   78 #include <machine/in_cksum.h>
   79 #include <netinet/ip_carp.h>
   80 #include <netinet/in_rss.h>
   81 
   82 #include <netipsec/ipsec_support.h>
   83 
   84 #include <sys/socketvar.h>
   85 
   86 #include <security/mac/mac_framework.h>
   87 
   88 #ifdef CTASSERT
   89 CTASSERT(sizeof(struct ip) == 20);
   90 #endif
   91 
   92 /* IP reassembly functions are defined in ip_reass.c. */
   93 extern void ipreass_init(void);
   94 extern void ipreass_drain(void);
   95 extern void ipreass_slowtimo(void);
   96 #ifdef VIMAGE
   97 extern void ipreass_destroy(void);
   98 #endif
   99 
  100 struct rmlock in_ifaddr_lock;
  101 RM_SYSINIT(in_ifaddr_lock, &in_ifaddr_lock, "in_ifaddr_lock");
  102 
  103 VNET_DEFINE(int, rsvp_on);
  104 
  105 VNET_DEFINE(int, ipforwarding);
  106 SYSCTL_INT(_net_inet_ip, IPCTL_FORWARDING, forwarding, CTLFLAG_VNET | CTLFLAG_RW,
  107     &VNET_NAME(ipforwarding), 0,
  108     "Enable IP forwarding between interfaces");
  109 
  110 static VNET_DEFINE(int, ipsendredirects) = 1;   /* XXX */
  111 #define V_ipsendredirects       VNET(ipsendredirects)
  112 SYSCTL_INT(_net_inet_ip, IPCTL_SENDREDIRECTS, redirect, CTLFLAG_VNET | CTLFLAG_RW,
  113     &VNET_NAME(ipsendredirects), 0,
  114     "Enable sending IP redirects");
  115 
  116 /*
  117  * XXX - Setting ip_checkinterface mostly implements the receive side of
  118  * the Strong ES model described in RFC 1122, but since the routing table
  119  * and transmit implementation do not implement the Strong ES model,
  120  * setting this to 1 results in an odd hybrid.
  121  *
  122  * XXX - ip_checkinterface currently must be disabled if you use ipnat
  123  * to translate the destination address to another local interface.
  124  *
  125  * XXX - ip_checkinterface must be disabled if you add IP aliases
  126  * to the loopback interface instead of the interface where the
  127  * packets for those addresses are received.
  128  */
  129 static VNET_DEFINE(int, ip_checkinterface);
  130 #define V_ip_checkinterface     VNET(ip_checkinterface)
  131 SYSCTL_INT(_net_inet_ip, OID_AUTO, check_interface, CTLFLAG_VNET | CTLFLAG_RW,
  132     &VNET_NAME(ip_checkinterface), 0,
  133     "Verify packet arrives on correct interface");
  134 
  135 VNET_DEFINE(struct pfil_head, inet_pfil_hook);  /* Packet filter hooks */
  136 
  137 static struct netisr_handler ip_nh = {
  138         .nh_name = "ip",
  139         .nh_handler = ip_input,
  140         .nh_proto = NETISR_IP,
  141 #ifdef  RSS
  142         .nh_m2cpuid = rss_soft_m2cpuid_v4,
  143         .nh_policy = NETISR_POLICY_CPU,
  144         .nh_dispatch = NETISR_DISPATCH_HYBRID,
  145 #else
  146         .nh_policy = NETISR_POLICY_FLOW,
  147 #endif
  148 };
  149 
  150 #ifdef  RSS
  151 /*
  152  * Directly dispatched frames are currently assumed
  153  * to have a flowid already calculated.
  154  *
  155  * It should likely have something that assert it
  156  * actually has valid flow details.
  157  */
  158 static struct netisr_handler ip_direct_nh = {
  159         .nh_name = "ip_direct",
  160         .nh_handler = ip_direct_input,
  161         .nh_proto = NETISR_IP_DIRECT,
  162         .nh_m2cpuid = rss_soft_m2cpuid_v4,
  163         .nh_policy = NETISR_POLICY_CPU,
  164         .nh_dispatch = NETISR_DISPATCH_HYBRID,
  165 };
  166 #endif
  167 
  168 extern  struct domain inetdomain;
  169 extern  struct protosw inetsw[];
  170 u_char  ip_protox[IPPROTO_MAX];
  171 VNET_DEFINE(struct in_ifaddrhead, in_ifaddrhead);  /* first inet address */
  172 VNET_DEFINE(struct in_ifaddrhashhead *, in_ifaddrhashtbl); /* inet addr hash table  */
  173 VNET_DEFINE(u_long, in_ifaddrhmask);            /* mask for hash table */
  174 
  175 #ifdef IPCTL_DEFMTU
  176 SYSCTL_INT(_net_inet_ip, IPCTL_DEFMTU, mtu, CTLFLAG_RW,
  177     &ip_mtu, 0, "Default MTU");
  178 #endif
  179 
  180 #ifdef IPSTEALTH
  181 VNET_DEFINE(int, ipstealth);
  182 SYSCTL_INT(_net_inet_ip, OID_AUTO, stealth, CTLFLAG_VNET | CTLFLAG_RW,
  183     &VNET_NAME(ipstealth), 0,
  184     "IP stealth mode, no TTL decrementation on forwarding");
  185 #endif
  186 
  187 /*
  188  * IP statistics are stored in the "array" of counter(9)s.
  189  */
  190 VNET_PCPUSTAT_DEFINE(struct ipstat, ipstat);
  191 VNET_PCPUSTAT_SYSINIT(ipstat);
  192 SYSCTL_VNET_PCPUSTAT(_net_inet_ip, IPCTL_STATS, stats, struct ipstat, ipstat,
  193     "IP statistics (struct ipstat, netinet/ip_var.h)");
  194 
  195 #ifdef VIMAGE
  196 VNET_PCPUSTAT_SYSUNINIT(ipstat);
  197 #endif /* VIMAGE */
  198 
  199 /*
  200  * Kernel module interface for updating ipstat.  The argument is an index
  201  * into ipstat treated as an array.
  202  */
  203 void
  204 kmod_ipstat_inc(int statnum)
  205 {
  206 
  207         counter_u64_add(VNET(ipstat)[statnum], 1);
  208 }
  209 
  210 void
  211 kmod_ipstat_dec(int statnum)
  212 {
  213 
  214         counter_u64_add(VNET(ipstat)[statnum], -1);
  215 }
  216 
  217 static int
  218 sysctl_netinet_intr_queue_maxlen(SYSCTL_HANDLER_ARGS)
  219 {
  220         int error, qlimit;
  221 
  222         netisr_getqlimit(&ip_nh, &qlimit);
  223         error = sysctl_handle_int(oidp, &qlimit, 0, req);
  224         if (error || !req->newptr)
  225                 return (error);
  226         if (qlimit < 1)
  227                 return (EINVAL);
  228         return (netisr_setqlimit(&ip_nh, qlimit));
  229 }
  230 SYSCTL_PROC(_net_inet_ip, IPCTL_INTRQMAXLEN, intr_queue_maxlen,
  231     CTLTYPE_INT|CTLFLAG_RW, 0, 0, sysctl_netinet_intr_queue_maxlen, "I",
  232     "Maximum size of the IP input queue");
  233 
  234 static int
  235 sysctl_netinet_intr_queue_drops(SYSCTL_HANDLER_ARGS)
  236 {
  237         u_int64_t qdrops_long;
  238         int error, qdrops;
  239 
  240         netisr_getqdrops(&ip_nh, &qdrops_long);
  241         qdrops = qdrops_long;
  242         error = sysctl_handle_int(oidp, &qdrops, 0, req);
  243         if (error || !req->newptr)
  244                 return (error);
  245         if (qdrops != 0)
  246                 return (EINVAL);
  247         netisr_clearqdrops(&ip_nh);
  248         return (0);
  249 }
  250 
  251 SYSCTL_PROC(_net_inet_ip, IPCTL_INTRQDROPS, intr_queue_drops,
  252     CTLTYPE_INT|CTLFLAG_RD, 0, 0, sysctl_netinet_intr_queue_drops, "I",
  253     "Number of packets dropped from the IP input queue");
  254 
  255 #ifdef  RSS
  256 static int
  257 sysctl_netinet_intr_direct_queue_maxlen(SYSCTL_HANDLER_ARGS)
  258 {
  259         int error, qlimit;
  260 
  261         netisr_getqlimit(&ip_direct_nh, &qlimit);
  262         error = sysctl_handle_int(oidp, &qlimit, 0, req);
  263         if (error || !req->newptr)
  264                 return (error);
  265         if (qlimit < 1)
  266                 return (EINVAL);
  267         return (netisr_setqlimit(&ip_direct_nh, qlimit));
  268 }
  269 SYSCTL_PROC(_net_inet_ip, IPCTL_INTRDQMAXLEN, intr_direct_queue_maxlen,
  270     CTLTYPE_INT|CTLFLAG_RW, 0, 0, sysctl_netinet_intr_direct_queue_maxlen,
  271     "I", "Maximum size of the IP direct input queue");
  272 
  273 static int
  274 sysctl_netinet_intr_direct_queue_drops(SYSCTL_HANDLER_ARGS)
  275 {
  276         u_int64_t qdrops_long;
  277         int error, qdrops;
  278 
  279         netisr_getqdrops(&ip_direct_nh, &qdrops_long);
  280         qdrops = qdrops_long;
  281         error = sysctl_handle_int(oidp, &qdrops, 0, req);
  282         if (error || !req->newptr)
  283                 return (error);
  284         if (qdrops != 0)
  285                 return (EINVAL);
  286         netisr_clearqdrops(&ip_direct_nh);
  287         return (0);
  288 }
  289 
  290 SYSCTL_PROC(_net_inet_ip, IPCTL_INTRDQDROPS, intr_direct_queue_drops,
  291     CTLTYPE_INT|CTLFLAG_RD, 0, 0, sysctl_netinet_intr_direct_queue_drops, "I",
  292     "Number of packets dropped from the IP direct input queue");
  293 #endif  /* RSS */
  294 
  295 /*
  296  * IP initialization: fill in IP protocol switch table.
  297  * All protocols not implemented in kernel go to raw IP protocol handler.
  298  */
  299 void
  300 ip_init(void)
  301 {
  302         struct protosw *pr;
  303         int i;
  304 
  305         TAILQ_INIT(&V_in_ifaddrhead);
  306         V_in_ifaddrhashtbl = hashinit(INADDR_NHASH, M_IFADDR, &V_in_ifaddrhmask);
  307 
  308         /* Initialize IP reassembly queue. */
  309         ipreass_init();
  310 
  311         /* Initialize packet filter hooks. */
  312         V_inet_pfil_hook.ph_type = PFIL_TYPE_AF;
  313         V_inet_pfil_hook.ph_af = AF_INET;
  314         if ((i = pfil_head_register(&V_inet_pfil_hook)) != 0)
  315                 printf("%s: WARNING: unable to register pfil hook, "
  316                         "error %d\n", __func__, i);
  317 
  318         if (hhook_head_register(HHOOK_TYPE_IPSEC_IN, AF_INET,
  319             &V_ipsec_hhh_in[HHOOK_IPSEC_INET],
  320             HHOOK_WAITOK | HHOOK_HEADISINVNET) != 0)
  321                 printf("%s: WARNING: unable to register input helper hook\n",
  322                     __func__);
  323         if (hhook_head_register(HHOOK_TYPE_IPSEC_OUT, AF_INET,
  324             &V_ipsec_hhh_out[HHOOK_IPSEC_INET],
  325             HHOOK_WAITOK | HHOOK_HEADISINVNET) != 0)
  326                 printf("%s: WARNING: unable to register output helper hook\n",
  327                     __func__);
  328 
  329         /* Skip initialization of globals for non-default instances. */
  330 #ifdef VIMAGE
  331         if (!IS_DEFAULT_VNET(curvnet)) {
  332                 netisr_register_vnet(&ip_nh);
  333 #ifdef  RSS
  334                 netisr_register_vnet(&ip_direct_nh);
  335 #endif
  336                 return;
  337         }
  338 #endif
  339 
  340         pr = pffindproto(PF_INET, IPPROTO_RAW, SOCK_RAW);
  341         if (pr == NULL)
  342                 panic("ip_init: PF_INET not found");
  343 
  344         /* Initialize the entire ip_protox[] array to IPPROTO_RAW. */
  345         for (i = 0; i < IPPROTO_MAX; i++)
  346                 ip_protox[i] = pr - inetsw;
  347         /*
  348          * Cycle through IP protocols and put them into the appropriate place
  349          * in ip_protox[].
  350          */
  351         for (pr = inetdomain.dom_protosw;
  352             pr < inetdomain.dom_protoswNPROTOSW; pr++)
  353                 if (pr->pr_domain->dom_family == PF_INET &&
  354                     pr->pr_protocol && pr->pr_protocol != IPPROTO_RAW) {
  355                         /* Be careful to only index valid IP protocols. */
  356                         if (pr->pr_protocol < IPPROTO_MAX)
  357                                 ip_protox[pr->pr_protocol] = pr - inetsw;
  358                 }
  359 
  360         netisr_register(&ip_nh);
  361 #ifdef  RSS
  362         netisr_register(&ip_direct_nh);
  363 #endif
  364 }
  365 
  366 #ifdef VIMAGE
  367 static void
  368 ip_destroy(void *unused __unused)
  369 {
  370         struct ifnet *ifp;
  371         int error;
  372 
  373 #ifdef  RSS
  374         netisr_unregister_vnet(&ip_direct_nh);
  375 #endif
  376         netisr_unregister_vnet(&ip_nh);
  377 
  378         if ((error = pfil_head_unregister(&V_inet_pfil_hook)) != 0)
  379                 printf("%s: WARNING: unable to unregister pfil hook, "
  380                     "error %d\n", __func__, error);
  381 
  382         error = hhook_head_deregister(V_ipsec_hhh_in[HHOOK_IPSEC_INET]);
  383         if (error != 0) {
  384                 printf("%s: WARNING: unable to deregister input helper hook "
  385                     "type HHOOK_TYPE_IPSEC_IN, id HHOOK_IPSEC_INET: "
  386                     "error %d returned\n", __func__, error);
  387         }
  388         error = hhook_head_deregister(V_ipsec_hhh_out[HHOOK_IPSEC_INET]);
  389         if (error != 0) {
  390                 printf("%s: WARNING: unable to deregister output helper hook "
  391                     "type HHOOK_TYPE_IPSEC_OUT, id HHOOK_IPSEC_INET: "
  392                     "error %d returned\n", __func__, error);
  393         }
  394 
  395         /* Remove the IPv4 addresses from all interfaces. */
  396         in_ifscrub_all();
  397 
  398         /* Make sure the IPv4 routes are gone as well. */
  399         IFNET_RLOCK();
  400         TAILQ_FOREACH(ifp, &V_ifnet, if_link)
  401                 rt_flushifroutes_af(ifp, AF_INET);
  402         IFNET_RUNLOCK();
  403 
  404         /* Destroy IP reassembly queue. */
  405         ipreass_destroy();
  406 
  407         /* Cleanup in_ifaddr hash table; should be empty. */
  408         hashdestroy(V_in_ifaddrhashtbl, M_IFADDR, V_in_ifaddrhmask);
  409 }
  410 
  411 VNET_SYSUNINIT(ip, SI_SUB_PROTO_DOMAIN, SI_ORDER_THIRD, ip_destroy, NULL);
  412 #endif
  413 
  414 #ifdef  RSS
  415 /*
  416  * IP direct input routine.
  417  *
  418  * This is called when reinjecting completed fragments where
  419  * all of the previous checking and book-keeping has been done.
  420  */
  421 void
  422 ip_direct_input(struct mbuf *m)
  423 {
  424         struct ip *ip;
  425         int hlen;
  426 
  427         ip = mtod(m, struct ip *);
  428         hlen = ip->ip_hl << 2;
  429 
  430 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
  431         if (IPSEC_ENABLED(ipv4)) {
  432                 if (IPSEC_INPUT(ipv4, m, hlen, ip->ip_p) != 0)
  433                         return;
  434         }
  435 #endif /* IPSEC */
  436         IPSTAT_INC(ips_delivered);
  437         (*inetsw[ip_protox[ip->ip_p]].pr_input)(&m, &hlen, ip->ip_p);
  438         return;
  439 }
  440 #endif
  441 
  442 /*
  443  * Ip input routine.  Checksum and byte swap header.  If fragmented
  444  * try to reassemble.  Process options.  Pass to next level.
  445  */
  446 void
  447 ip_input(struct mbuf *m)
  448 {
  449         struct ip *ip = NULL;
  450         struct in_ifaddr *ia = NULL;
  451         struct ifaddr *ifa;
  452         struct ifnet *ifp;
  453         int    checkif, hlen = 0;
  454         uint16_t sum, ip_len;
  455         int dchg = 0;                           /* dest changed after fw */
  456         struct in_addr odst;                    /* original dst address */
  457 
  458         M_ASSERTPKTHDR(m);
  459 
  460         if (m->m_flags & M_FASTFWD_OURS) {
  461                 m->m_flags &= ~M_FASTFWD_OURS;
  462                 /* Set up some basics that will be used later. */
  463                 ip = mtod(m, struct ip *);
  464                 hlen = ip->ip_hl << 2;
  465                 ip_len = ntohs(ip->ip_len);
  466                 goto ours;
  467         }
  468 
  469         IPSTAT_INC(ips_total);
  470 
  471         if (m->m_pkthdr.len < sizeof(struct ip))
  472                 goto tooshort;
  473 
  474         if (m->m_len < sizeof (struct ip) &&
  475             (m = m_pullup(m, sizeof (struct ip))) == NULL) {
  476                 IPSTAT_INC(ips_toosmall);
  477                 return;
  478         }
  479         ip = mtod(m, struct ip *);
  480 
  481         if (ip->ip_v != IPVERSION) {
  482                 IPSTAT_INC(ips_badvers);
  483                 goto bad;
  484         }
  485 
  486         hlen = ip->ip_hl << 2;
  487         if (hlen < sizeof(struct ip)) { /* minimum header length */
  488                 IPSTAT_INC(ips_badhlen);
  489                 goto bad;
  490         }
  491         if (hlen > m->m_len) {
  492                 if ((m = m_pullup(m, hlen)) == NULL) {
  493                         IPSTAT_INC(ips_badhlen);
  494                         return;
  495                 }
  496                 ip = mtod(m, struct ip *);
  497         }
  498 
  499         IP_PROBE(receive, NULL, NULL, ip, m->m_pkthdr.rcvif, ip, NULL);
  500 
  501         /* 127/8 must not appear on wire - RFC1122 */
  502         ifp = m->m_pkthdr.rcvif;
  503         if ((ntohl(ip->ip_dst.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET ||
  504             (ntohl(ip->ip_src.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET) {
  505                 if ((ifp->if_flags & IFF_LOOPBACK) == 0) {
  506                         IPSTAT_INC(ips_badaddr);
  507                         goto bad;
  508                 }
  509         }
  510 
  511         if (m->m_pkthdr.csum_flags & CSUM_IP_CHECKED) {
  512                 sum = !(m->m_pkthdr.csum_flags & CSUM_IP_VALID);
  513         } else {
  514                 if (hlen == sizeof(struct ip)) {
  515                         sum = in_cksum_hdr(ip);
  516                 } else {
  517                         sum = in_cksum(m, hlen);
  518                 }
  519         }
  520         if (sum) {
  521                 IPSTAT_INC(ips_badsum);
  522                 goto bad;
  523         }
  524 
  525 #ifdef ALTQ
  526         if (altq_input != NULL && (*altq_input)(m, AF_INET) == 0)
  527                 /* packet is dropped by traffic conditioner */
  528                 return;
  529 #endif
  530 
  531         ip_len = ntohs(ip->ip_len);
  532         if (ip_len < hlen) {
  533                 IPSTAT_INC(ips_badlen);
  534                 goto bad;
  535         }
  536 
  537         /*
  538          * Check that the amount of data in the buffers
  539          * is as at least much as the IP header would have us expect.
  540          * Trim mbufs if longer than we expect.
  541          * Drop packet if shorter than we expect.
  542          */
  543         if (m->m_pkthdr.len < ip_len) {
  544 tooshort:
  545                 IPSTAT_INC(ips_tooshort);
  546                 goto bad;
  547         }
  548         if (m->m_pkthdr.len > ip_len) {
  549                 if (m->m_len == m->m_pkthdr.len) {
  550                         m->m_len = ip_len;
  551                         m->m_pkthdr.len = ip_len;
  552                 } else
  553                         m_adj(m, ip_len - m->m_pkthdr.len);
  554         }
  555 
  556         /*
  557          * Try to forward the packet, but if we fail continue.
  558          * ip_tryforward() does inbound and outbound packet firewall
  559          * processing. If firewall has decided that destination becomes
  560          * our local address, it sets M_FASTFWD_OURS flag. In this
  561          * case skip another inbound firewall processing and update
  562          * ip pointer.
  563          */
  564         if (V_ipforwarding != 0
  565 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
  566             && (!IPSEC_ENABLED(ipv4) ||
  567             IPSEC_CAPS(ipv4, m, IPSEC_CAP_OPERABLE) == 0)
  568 #endif
  569             ) {
  570                 if ((m = ip_tryforward(m)) == NULL)
  571                         return;
  572                 if (m->m_flags & M_FASTFWD_OURS) {
  573                         m->m_flags &= ~M_FASTFWD_OURS;
  574                         ip = mtod(m, struct ip *);
  575                         goto ours;
  576                 }
  577         }
  578 
  579 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
  580         /*
  581          * Bypass packet filtering for packets previously handled by IPsec.
  582          */
  583         if (IPSEC_ENABLED(ipv4) &&
  584             IPSEC_CAPS(ipv4, m, IPSEC_CAP_BYPASS_FILTER) != 0)
  585                         goto passin;
  586 #endif
  587 
  588         /*
  589          * Run through list of hooks for input packets.
  590          *
  591          * NB: Beware of the destination address changing (e.g.
  592          *     by NAT rewriting).  When this happens, tell
  593          *     ip_forward to do the right thing.
  594          */
  595 
  596         /* Jump over all PFIL processing if hooks are not active. */
  597         if (!PFIL_HOOKED(&V_inet_pfil_hook))
  598                 goto passin;
  599 
  600         odst = ip->ip_dst;
  601         if (pfil_run_hooks(&V_inet_pfil_hook, &m, ifp, PFIL_IN, NULL) != 0)
  602                 return;
  603         if (m == NULL)                  /* consumed by filter */
  604                 return;
  605 
  606         ip = mtod(m, struct ip *);
  607         dchg = (odst.s_addr != ip->ip_dst.s_addr);
  608         ifp = m->m_pkthdr.rcvif;
  609 
  610         if (m->m_flags & M_FASTFWD_OURS) {
  611                 m->m_flags &= ~M_FASTFWD_OURS;
  612                 goto ours;
  613         }
  614         if (m->m_flags & M_IP_NEXTHOP) {
  615                 if (m_tag_find(m, PACKET_TAG_IPFORWARD, NULL) != NULL) {
  616                         /*
  617                          * Directly ship the packet on.  This allows
  618                          * forwarding packets originally destined to us
  619                          * to some other directly connected host.
  620                          */
  621                         ip_forward(m, 1);
  622                         return;
  623                 }
  624         }
  625 passin:
  626 
  627         /*
  628          * Process options and, if not destined for us,
  629          * ship it on.  ip_dooptions returns 1 when an
  630          * error was detected (causing an icmp message
  631          * to be sent and the original packet to be freed).
  632          */
  633         if (hlen > sizeof (struct ip) && ip_dooptions(m, 0))
  634                 return;
  635 
  636         /* greedy RSVP, snatches any PATH packet of the RSVP protocol and no
  637          * matter if it is destined to another node, or whether it is 
  638          * a multicast one, RSVP wants it! and prevents it from being forwarded
  639          * anywhere else. Also checks if the rsvp daemon is running before
  640          * grabbing the packet.
  641          */
  642         if (V_rsvp_on && ip->ip_p==IPPROTO_RSVP) 
  643                 goto ours;
  644 
  645         /*
  646          * Check our list of addresses, to see if the packet is for us.
  647          * If we don't have any addresses, assume any unicast packet
  648          * we receive might be for us (and let the upper layers deal
  649          * with it).
  650          */
  651         if (TAILQ_EMPTY(&V_in_ifaddrhead) &&
  652             (m->m_flags & (M_MCAST|M_BCAST)) == 0)
  653                 goto ours;
  654 
  655         /*
  656          * Enable a consistency check between the destination address
  657          * and the arrival interface for a unicast packet (the RFC 1122
  658          * strong ES model) if IP forwarding is disabled and the packet
  659          * is not locally generated and the packet is not subject to
  660          * 'ipfw fwd'.
  661          *
  662          * XXX - Checking also should be disabled if the destination
  663          * address is ipnat'ed to a different interface.
  664          *
  665          * XXX - Checking is incompatible with IP aliases added
  666          * to the loopback interface instead of the interface where
  667          * the packets are received.
  668          *
  669          * XXX - This is the case for carp vhost IPs as well so we
  670          * insert a workaround. If the packet got here, we already
  671          * checked with carp_iamatch() and carp_forus().
  672          */
  673         checkif = V_ip_checkinterface && (V_ipforwarding == 0) && 
  674             ifp != NULL && ((ifp->if_flags & IFF_LOOPBACK) == 0) &&
  675             ifp->if_carp == NULL && (dchg == 0);
  676 
  677         /*
  678          * Check for exact addresses in the hash bucket.
  679          */
  680         /* IN_IFADDR_RLOCK(); */
  681         LIST_FOREACH(ia, INADDR_HASH(ip->ip_dst.s_addr), ia_hash) {
  682                 /*
  683                  * If the address matches, verify that the packet
  684                  * arrived via the correct interface if checking is
  685                  * enabled.
  686                  */
  687                 if (IA_SIN(ia)->sin_addr.s_addr == ip->ip_dst.s_addr && 
  688                     (!checkif || ia->ia_ifp == ifp)) {
  689                         counter_u64_add(ia->ia_ifa.ifa_ipackets, 1);
  690                         counter_u64_add(ia->ia_ifa.ifa_ibytes,
  691                             m->m_pkthdr.len);
  692                         /* IN_IFADDR_RUNLOCK(); */
  693                         goto ours;
  694                 }
  695         }
  696         /* IN_IFADDR_RUNLOCK(); */
  697 
  698         /*
  699          * Check for broadcast addresses.
  700          *
  701          * Only accept broadcast packets that arrive via the matching
  702          * interface.  Reception of forwarded directed broadcasts would
  703          * be handled via ip_forward() and ether_output() with the loopback
  704          * into the stack for SIMPLEX interfaces handled by ether_output().
  705          */
  706         if (ifp != NULL && ifp->if_flags & IFF_BROADCAST) {
  707                 IF_ADDR_RLOCK(ifp);
  708                 TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
  709                         if (ifa->ifa_addr->sa_family != AF_INET)
  710                                 continue;
  711                         ia = ifatoia(ifa);
  712                         if (satosin(&ia->ia_broadaddr)->sin_addr.s_addr ==
  713                             ip->ip_dst.s_addr) {
  714                                 counter_u64_add(ia->ia_ifa.ifa_ipackets, 1);
  715                                 counter_u64_add(ia->ia_ifa.ifa_ibytes,
  716                                     m->m_pkthdr.len);
  717                                 IF_ADDR_RUNLOCK(ifp);
  718                                 goto ours;
  719                         }
  720 #ifdef BOOTP_COMPAT
  721                         if (IA_SIN(ia)->sin_addr.s_addr == INADDR_ANY) {
  722                                 counter_u64_add(ia->ia_ifa.ifa_ipackets, 1);
  723                                 counter_u64_add(ia->ia_ifa.ifa_ibytes,
  724                                     m->m_pkthdr.len);
  725                                 IF_ADDR_RUNLOCK(ifp);
  726                                 goto ours;
  727                         }
  728 #endif
  729                 }
  730                 IF_ADDR_RUNLOCK(ifp);
  731                 ia = NULL;
  732         }
  733         /* RFC 3927 2.7: Do not forward datagrams for 169.254.0.0/16. */
  734         if (IN_LINKLOCAL(ntohl(ip->ip_dst.s_addr))) {
  735                 IPSTAT_INC(ips_cantforward);
  736                 m_freem(m);
  737                 return;
  738         }
  739         if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr))) {
  740                 if (V_ip_mrouter) {
  741                         /*
  742                          * If we are acting as a multicast router, all
  743                          * incoming multicast packets are passed to the
  744                          * kernel-level multicast forwarding function.
  745                          * The packet is returned (relatively) intact; if
  746                          * ip_mforward() returns a non-zero value, the packet
  747                          * must be discarded, else it may be accepted below.
  748                          */
  749                         if (ip_mforward && ip_mforward(ip, ifp, m, 0) != 0) {
  750                                 IPSTAT_INC(ips_cantforward);
  751                                 m_freem(m);
  752                                 return;
  753                         }
  754 
  755                         /*
  756                          * The process-level routing daemon needs to receive
  757                          * all multicast IGMP packets, whether or not this
  758                          * host belongs to their destination groups.
  759                          */
  760                         if (ip->ip_p == IPPROTO_IGMP)
  761                                 goto ours;
  762                         IPSTAT_INC(ips_forward);
  763                 }
  764                 /*
  765                  * Assume the packet is for us, to avoid prematurely taking
  766                  * a lock on the in_multi hash. Protocols must perform
  767                  * their own filtering and update statistics accordingly.
  768                  */
  769                 goto ours;
  770         }
  771         if (ip->ip_dst.s_addr == (u_long)INADDR_BROADCAST)
  772                 goto ours;
  773         if (ip->ip_dst.s_addr == INADDR_ANY)
  774                 goto ours;
  775 
  776         /*
  777          * Not for us; forward if possible and desirable.
  778          */
  779         if (V_ipforwarding == 0) {
  780                 IPSTAT_INC(ips_cantforward);
  781                 m_freem(m);
  782         } else {
  783                 ip_forward(m, dchg);
  784         }
  785         return;
  786 
  787 ours:
  788 #ifdef IPSTEALTH
  789         /*
  790          * IPSTEALTH: Process non-routing options only
  791          * if the packet is destined for us.
  792          */
  793         if (V_ipstealth && hlen > sizeof (struct ip) && ip_dooptions(m, 1))
  794                 return;
  795 #endif /* IPSTEALTH */
  796 
  797         /*
  798          * Attempt reassembly; if it succeeds, proceed.
  799          * ip_reass() will return a different mbuf.
  800          */
  801         if (ip->ip_off & htons(IP_MF | IP_OFFMASK)) {
  802                 /* XXXGL: shouldn't we save & set m_flags? */
  803                 m = ip_reass(m);
  804                 if (m == NULL)
  805                         return;
  806                 ip = mtod(m, struct ip *);
  807                 /* Get the header length of the reassembled packet */
  808                 hlen = ip->ip_hl << 2;
  809         }
  810 
  811 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
  812         if (IPSEC_ENABLED(ipv4)) {
  813                 if (IPSEC_INPUT(ipv4, m, hlen, ip->ip_p) != 0)
  814                         return;
  815         }
  816 #endif /* IPSEC */
  817 
  818         /*
  819          * Switch out to protocol's input routine.
  820          */
  821         IPSTAT_INC(ips_delivered);
  822 
  823         (*inetsw[ip_protox[ip->ip_p]].pr_input)(&m, &hlen, ip->ip_p);
  824         return;
  825 bad:
  826         m_freem(m);
  827 }
  828 
  829 /*
  830  * IP timer processing;
  831  * if a timer expires on a reassembly
  832  * queue, discard it.
  833  */
  834 void
  835 ip_slowtimo(void)
  836 {
  837         VNET_ITERATOR_DECL(vnet_iter);
  838 
  839         VNET_LIST_RLOCK_NOSLEEP();
  840         VNET_FOREACH(vnet_iter) {
  841                 CURVNET_SET(vnet_iter);
  842                 ipreass_slowtimo();
  843                 CURVNET_RESTORE();
  844         }
  845         VNET_LIST_RUNLOCK_NOSLEEP();
  846 }
  847 
  848 void
  849 ip_drain(void)
  850 {
  851         VNET_ITERATOR_DECL(vnet_iter);
  852 
  853         VNET_LIST_RLOCK_NOSLEEP();
  854         VNET_FOREACH(vnet_iter) {
  855                 CURVNET_SET(vnet_iter);
  856                 ipreass_drain();
  857                 CURVNET_RESTORE();
  858         }
  859         VNET_LIST_RUNLOCK_NOSLEEP();
  860 }
  861 
  862 /*
  863  * The protocol to be inserted into ip_protox[] must be already registered
  864  * in inetsw[], either statically or through pf_proto_register().
  865  */
  866 int
  867 ipproto_register(short ipproto)
  868 {
  869         struct protosw *pr;
  870 
  871         /* Sanity checks. */
  872         if (ipproto <= 0 || ipproto >= IPPROTO_MAX)
  873                 return (EPROTONOSUPPORT);
  874 
  875         /*
  876          * The protocol slot must not be occupied by another protocol
  877          * already.  An index pointing to IPPROTO_RAW is unused.
  878          */
  879         pr = pffindproto(PF_INET, IPPROTO_RAW, SOCK_RAW);
  880         if (pr == NULL)
  881                 return (EPFNOSUPPORT);
  882         if (ip_protox[ipproto] != pr - inetsw)  /* IPPROTO_RAW */
  883                 return (EEXIST);
  884 
  885         /* Find the protocol position in inetsw[] and set the index. */
  886         for (pr = inetdomain.dom_protosw;
  887              pr < inetdomain.dom_protoswNPROTOSW; pr++) {
  888                 if (pr->pr_domain->dom_family == PF_INET &&
  889                     pr->pr_protocol && pr->pr_protocol == ipproto) {
  890                         ip_protox[pr->pr_protocol] = pr - inetsw;
  891                         return (0);
  892                 }
  893         }
  894         return (EPROTONOSUPPORT);
  895 }
  896 
  897 int
  898 ipproto_unregister(short ipproto)
  899 {
  900         struct protosw *pr;
  901 
  902         /* Sanity checks. */
  903         if (ipproto <= 0 || ipproto >= IPPROTO_MAX)
  904                 return (EPROTONOSUPPORT);
  905 
  906         /* Check if the protocol was indeed registered. */
  907         pr = pffindproto(PF_INET, IPPROTO_RAW, SOCK_RAW);
  908         if (pr == NULL)
  909                 return (EPFNOSUPPORT);
  910         if (ip_protox[ipproto] == pr - inetsw)  /* IPPROTO_RAW */
  911                 return (ENOENT);
  912 
  913         /* Reset the protocol slot to IPPROTO_RAW. */
  914         ip_protox[ipproto] = pr - inetsw;
  915         return (0);
  916 }
  917 
  918 u_char inetctlerrmap[PRC_NCMDS] = {
  919         0,              0,              0,              0,
  920         0,              EMSGSIZE,       EHOSTDOWN,      EHOSTUNREACH,
  921         EHOSTUNREACH,   EHOSTUNREACH,   ECONNREFUSED,   ECONNREFUSED,
  922         EMSGSIZE,       EHOSTUNREACH,   0,              0,
  923         0,              0,              EHOSTUNREACH,   0,
  924         ENOPROTOOPT,    ECONNREFUSED
  925 };
  926 
  927 /*
  928  * Forward a packet.  If some error occurs return the sender
  929  * an icmp packet.  Note we can't always generate a meaningful
  930  * icmp message because icmp doesn't have a large enough repertoire
  931  * of codes and types.
  932  *
  933  * If not forwarding, just drop the packet.  This could be confusing
  934  * if ipforwarding was zero but some routing protocol was advancing
  935  * us as a gateway to somewhere.  However, we must let the routing
  936  * protocol deal with that.
  937  *
  938  * The srcrt parameter indicates whether the packet is being forwarded
  939  * via a source route.
  940  */
  941 void
  942 ip_forward(struct mbuf *m, int srcrt)
  943 {
  944         struct ip *ip = mtod(m, struct ip *);
  945         struct in_ifaddr *ia;
  946         struct mbuf *mcopy;
  947         struct sockaddr_in *sin;
  948         struct in_addr dest;
  949         struct route ro;
  950         int error, type = 0, code = 0, mtu = 0;
  951 
  952         if (m->m_flags & (M_BCAST|M_MCAST) || in_canforward(ip->ip_dst) == 0) {
  953                 IPSTAT_INC(ips_cantforward);
  954                 m_freem(m);
  955                 return;
  956         }
  957         if (
  958 #ifdef IPSTEALTH
  959             V_ipstealth == 0 &&
  960 #endif
  961             ip->ip_ttl <= IPTTLDEC) {
  962                 icmp_error(m, ICMP_TIMXCEED, ICMP_TIMXCEED_INTRANS, 0, 0);
  963                 return;
  964         }
  965 
  966         bzero(&ro, sizeof(ro));
  967         sin = (struct sockaddr_in *)&ro.ro_dst;
  968         sin->sin_family = AF_INET;
  969         sin->sin_len = sizeof(*sin);
  970         sin->sin_addr = ip->ip_dst;
  971 #ifdef RADIX_MPATH
  972         rtalloc_mpath_fib(&ro,
  973             ntohl(ip->ip_src.s_addr ^ ip->ip_dst.s_addr),
  974             M_GETFIB(m));
  975 #else
  976         in_rtalloc_ign(&ro, 0, M_GETFIB(m));
  977 #endif
  978         if (ro.ro_rt != NULL) {
  979                 ia = ifatoia(ro.ro_rt->rt_ifa);
  980                 ifa_ref(&ia->ia_ifa);
  981         } else
  982                 ia = NULL;
  983         /*
  984          * Save the IP header and at most 8 bytes of the payload,
  985          * in case we need to generate an ICMP message to the src.
  986          *
  987          * XXX this can be optimized a lot by saving the data in a local
  988          * buffer on the stack (72 bytes at most), and only allocating the
  989          * mbuf if really necessary. The vast majority of the packets
  990          * are forwarded without having to send an ICMP back (either
  991          * because unnecessary, or because rate limited), so we are
  992          * really we are wasting a lot of work here.
  993          *
  994          * We don't use m_copy() because it might return a reference
  995          * to a shared cluster. Both this function and ip_output()
  996          * assume exclusive access to the IP header in `m', so any
  997          * data in a cluster may change before we reach icmp_error().
  998          */
  999         mcopy = m_gethdr(M_NOWAIT, m->m_type);
 1000         if (mcopy != NULL && !m_dup_pkthdr(mcopy, m, M_NOWAIT)) {
 1001                 /*
 1002                  * It's probably ok if the pkthdr dup fails (because
 1003                  * the deep copy of the tag chain failed), but for now
 1004                  * be conservative and just discard the copy since
 1005                  * code below may some day want the tags.
 1006                  */
 1007                 m_free(mcopy);
 1008                 mcopy = NULL;
 1009         }
 1010         if (mcopy != NULL) {
 1011                 mcopy->m_len = min(ntohs(ip->ip_len), M_TRAILINGSPACE(mcopy));
 1012                 mcopy->m_pkthdr.len = mcopy->m_len;
 1013                 m_copydata(m, 0, mcopy->m_len, mtod(mcopy, caddr_t));
 1014         }
 1015 #ifdef IPSTEALTH
 1016         if (V_ipstealth == 0)
 1017 #endif
 1018                 ip->ip_ttl -= IPTTLDEC;
 1019 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
 1020         if (IPSEC_ENABLED(ipv4)) {
 1021                 if ((error = IPSEC_FORWARD(ipv4, m)) != 0) {
 1022                         /* mbuf consumed by IPsec */
 1023                         m_freem(mcopy);
 1024                         if (error != EINPROGRESS)
 1025                                 IPSTAT_INC(ips_cantforward);
 1026                         return;
 1027                 }
 1028                 /* No IPsec processing required */
 1029         }
 1030 #endif /* IPSEC */
 1031         /*
 1032          * If forwarding packet using same interface that it came in on,
 1033          * perhaps should send a redirect to sender to shortcut a hop.
 1034          * Only send redirect if source is sending directly to us,
 1035          * and if packet was not source routed (or has any options).
 1036          * Also, don't send redirect if forwarding using a default route
 1037          * or a route modified by a redirect.
 1038          */
 1039         dest.s_addr = 0;
 1040         if (!srcrt && V_ipsendredirects &&
 1041             ia != NULL && ia->ia_ifp == m->m_pkthdr.rcvif) {
 1042                 struct rtentry *rt;
 1043 
 1044                 rt = ro.ro_rt;
 1045 
 1046                 if (rt && (rt->rt_flags & (RTF_DYNAMIC|RTF_MODIFIED)) == 0 &&
 1047                     satosin(rt_key(rt))->sin_addr.s_addr != 0) {
 1048 #define RTA(rt) ((struct in_ifaddr *)(rt->rt_ifa))
 1049                         u_long src = ntohl(ip->ip_src.s_addr);
 1050 
 1051                         if (RTA(rt) &&
 1052                             (src & RTA(rt)->ia_subnetmask) == RTA(rt)->ia_subnet) {
 1053                                 if (rt->rt_flags & RTF_GATEWAY)
 1054                                         dest.s_addr = satosin(rt->rt_gateway)->sin_addr.s_addr;
 1055                                 else
 1056                                         dest.s_addr = ip->ip_dst.s_addr;
 1057                                 /* Router requirements says to only send host redirects */
 1058                                 type = ICMP_REDIRECT;
 1059                                 code = ICMP_REDIRECT_HOST;
 1060                         }
 1061                 }
 1062         }
 1063 
 1064         error = ip_output(m, NULL, &ro, IP_FORWARDING, NULL, NULL);
 1065 
 1066         if (error == EMSGSIZE && ro.ro_rt)
 1067                 mtu = ro.ro_rt->rt_mtu;
 1068         RO_RTFREE(&ro);
 1069 
 1070         if (error)
 1071                 IPSTAT_INC(ips_cantforward);
 1072         else {
 1073                 IPSTAT_INC(ips_forward);
 1074                 if (type)
 1075                         IPSTAT_INC(ips_redirectsent);
 1076                 else {
 1077                         if (mcopy)
 1078                                 m_freem(mcopy);
 1079                         if (ia != NULL)
 1080                                 ifa_free(&ia->ia_ifa);
 1081                         return;
 1082                 }
 1083         }
 1084         if (mcopy == NULL) {
 1085                 if (ia != NULL)
 1086                         ifa_free(&ia->ia_ifa);
 1087                 return;
 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                 if (ia != NULL)
 1131                         ifa_free(&ia->ia_ifa);
 1132                 return;
 1133         }
 1134         if (ia != NULL)
 1135                 ifa_free(&ia->ia_ifa);
 1136         icmp_error(mcopy, type, code, dest.s_addr, mtu);
 1137 }
 1138 
 1139 void
 1140 ip_savecontrol(struct inpcb *inp, struct mbuf **mp, struct ip *ip,
 1141     struct mbuf *m)
 1142 {
 1143 
 1144         if (inp->inp_socket->so_options & (SO_BINTIME | SO_TIMESTAMP)) {
 1145                 struct bintime bt;
 1146 
 1147                 bintime(&bt);
 1148                 if (inp->inp_socket->so_options & SO_BINTIME) {
 1149                         *mp = sbcreatecontrol((caddr_t)&bt, sizeof(bt),
 1150                             SCM_BINTIME, SOL_SOCKET);
 1151                         if (*mp)
 1152                                 mp = &(*mp)->m_next;
 1153                 }
 1154                 if (inp->inp_socket->so_options & SO_TIMESTAMP) {
 1155                         struct timeval tv;
 1156 
 1157                         bintime2timeval(&bt, &tv);
 1158                         *mp = sbcreatecontrol((caddr_t)&tv, sizeof(tv),
 1159                             SCM_TIMESTAMP, SOL_SOCKET);
 1160                         if (*mp)
 1161                                 mp = &(*mp)->m_next;
 1162                 }
 1163         }
 1164         if (inp->inp_flags & INP_RECVDSTADDR) {
 1165                 *mp = sbcreatecontrol((caddr_t)&ip->ip_dst,
 1166                     sizeof(struct in_addr), IP_RECVDSTADDR, IPPROTO_IP);
 1167                 if (*mp)
 1168                         mp = &(*mp)->m_next;
 1169         }
 1170         if (inp->inp_flags & INP_RECVTTL) {
 1171                 *mp = sbcreatecontrol((caddr_t)&ip->ip_ttl,
 1172                     sizeof(u_char), IP_RECVTTL, IPPROTO_IP);
 1173                 if (*mp)
 1174                         mp = &(*mp)->m_next;
 1175         }
 1176 #ifdef notyet
 1177         /* XXX
 1178          * Moving these out of udp_input() made them even more broken
 1179          * than they already were.
 1180          */
 1181         /* options were tossed already */
 1182         if (inp->inp_flags & INP_RECVOPTS) {
 1183                 *mp = sbcreatecontrol((caddr_t)opts_deleted_above,
 1184                     sizeof(struct in_addr), IP_RECVOPTS, IPPROTO_IP);
 1185                 if (*mp)
 1186                         mp = &(*mp)->m_next;
 1187         }
 1188         /* ip_srcroute doesn't do what we want here, need to fix */
 1189         if (inp->inp_flags & INP_RECVRETOPTS) {
 1190                 *mp = sbcreatecontrol((caddr_t)ip_srcroute(m),
 1191                     sizeof(struct in_addr), IP_RECVRETOPTS, IPPROTO_IP);
 1192                 if (*mp)
 1193                         mp = &(*mp)->m_next;
 1194         }
 1195 #endif
 1196         if (inp->inp_flags & INP_RECVIF) {
 1197                 struct ifnet *ifp;
 1198                 struct sdlbuf {
 1199                         struct sockaddr_dl sdl;
 1200                         u_char  pad[32];
 1201                 } sdlbuf;
 1202                 struct sockaddr_dl *sdp;
 1203                 struct sockaddr_dl *sdl2 = &sdlbuf.sdl;
 1204 
 1205                 if ((ifp = m->m_pkthdr.rcvif) &&
 1206                     ifp->if_index && ifp->if_index <= V_if_index) {
 1207                         sdp = (struct sockaddr_dl *)ifp->if_addr->ifa_addr;
 1208                         /*
 1209                          * Change our mind and don't try copy.
 1210                          */
 1211                         if (sdp->sdl_family != AF_LINK ||
 1212                             sdp->sdl_len > sizeof(sdlbuf)) {
 1213                                 goto makedummy;
 1214                         }
 1215                         bcopy(sdp, sdl2, sdp->sdl_len);
 1216                 } else {
 1217 makedummy:      
 1218                         sdl2->sdl_len =
 1219                             offsetof(struct sockaddr_dl, sdl_data[0]);
 1220                         sdl2->sdl_family = AF_LINK;
 1221                         sdl2->sdl_index = 0;
 1222                         sdl2->sdl_nlen = sdl2->sdl_alen = sdl2->sdl_slen = 0;
 1223                 }
 1224                 *mp = sbcreatecontrol((caddr_t)sdl2, sdl2->sdl_len,
 1225                     IP_RECVIF, IPPROTO_IP);
 1226                 if (*mp)
 1227                         mp = &(*mp)->m_next;
 1228         }
 1229         if (inp->inp_flags & INP_RECVTOS) {
 1230                 *mp = sbcreatecontrol((caddr_t)&ip->ip_tos,
 1231                     sizeof(u_char), IP_RECVTOS, IPPROTO_IP);
 1232                 if (*mp)
 1233                         mp = &(*mp)->m_next;
 1234         }
 1235 
 1236         if (inp->inp_flags2 & INP_RECVFLOWID) {
 1237                 uint32_t flowid, flow_type;
 1238 
 1239                 flowid = m->m_pkthdr.flowid;
 1240                 flow_type = M_HASHTYPE_GET(m);
 1241 
 1242                 /*
 1243                  * XXX should handle the failure of one or the
 1244                  * other - don't populate both?
 1245                  */
 1246                 *mp = sbcreatecontrol((caddr_t) &flowid,
 1247                     sizeof(uint32_t), IP_FLOWID, IPPROTO_IP);
 1248                 if (*mp)
 1249                         mp = &(*mp)->m_next;
 1250                 *mp = sbcreatecontrol((caddr_t) &flow_type,
 1251                     sizeof(uint32_t), IP_FLOWTYPE, IPPROTO_IP);
 1252                 if (*mp)
 1253                         mp = &(*mp)->m_next;
 1254         }
 1255 
 1256 #ifdef  RSS
 1257         if (inp->inp_flags2 & INP_RECVRSSBUCKETID) {
 1258                 uint32_t flowid, flow_type;
 1259                 uint32_t rss_bucketid;
 1260 
 1261                 flowid = m->m_pkthdr.flowid;
 1262                 flow_type = M_HASHTYPE_GET(m);
 1263 
 1264                 if (rss_hash2bucket(flowid, flow_type, &rss_bucketid) == 0) {
 1265                         *mp = sbcreatecontrol((caddr_t) &rss_bucketid,
 1266                            sizeof(uint32_t), IP_RSSBUCKETID, IPPROTO_IP);
 1267                         if (*mp)
 1268                                 mp = &(*mp)->m_next;
 1269                 }
 1270         }
 1271 #endif
 1272 }
 1273 
 1274 /*
 1275  * XXXRW: Multicast routing code in ip_mroute.c is generally MPSAFE, but the
 1276  * ip_rsvp and ip_rsvp_on variables need to be interlocked with rsvp_on
 1277  * locking.  This code remains in ip_input.c as ip_mroute.c is optionally
 1278  * compiled.
 1279  */
 1280 static VNET_DEFINE(int, ip_rsvp_on);
 1281 VNET_DEFINE(struct socket *, ip_rsvpd);
 1282 
 1283 #define V_ip_rsvp_on            VNET(ip_rsvp_on)
 1284 
 1285 int
 1286 ip_rsvp_init(struct socket *so)
 1287 {
 1288 
 1289         if (so->so_type != SOCK_RAW ||
 1290             so->so_proto->pr_protocol != IPPROTO_RSVP)
 1291                 return EOPNOTSUPP;
 1292 
 1293         if (V_ip_rsvpd != NULL)
 1294                 return EADDRINUSE;
 1295 
 1296         V_ip_rsvpd = so;
 1297         /*
 1298          * This may seem silly, but we need to be sure we don't over-increment
 1299          * the RSVP counter, in case something slips up.
 1300          */
 1301         if (!V_ip_rsvp_on) {
 1302                 V_ip_rsvp_on = 1;
 1303                 V_rsvp_on++;
 1304         }
 1305 
 1306         return 0;
 1307 }
 1308 
 1309 int
 1310 ip_rsvp_done(void)
 1311 {
 1312 
 1313         V_ip_rsvpd = NULL;
 1314         /*
 1315          * This may seem silly, but we need to be sure we don't over-decrement
 1316          * the RSVP counter, in case something slips up.
 1317          */
 1318         if (V_ip_rsvp_on) {
 1319                 V_ip_rsvp_on = 0;
 1320                 V_rsvp_on--;
 1321         }
 1322         return 0;
 1323 }
 1324 
 1325 int
 1326 rsvp_input(struct mbuf **mp, int *offp, int proto)
 1327 {
 1328         struct mbuf *m;
 1329 
 1330         m = *mp;
 1331         *mp = NULL;
 1332 
 1333         if (rsvp_input_p) { /* call the real one if loaded */
 1334                 *mp = m;
 1335                 rsvp_input_p(mp, offp, proto);
 1336                 return (IPPROTO_DONE);
 1337         }
 1338 
 1339         /* Can still get packets with rsvp_on = 0 if there is a local member
 1340          * of the group to which the RSVP packet is addressed.  But in this
 1341          * case we want to throw the packet away.
 1342          */
 1343         
 1344         if (!V_rsvp_on) {
 1345                 m_freem(m);
 1346                 return (IPPROTO_DONE);
 1347         }
 1348 
 1349         if (V_ip_rsvpd != NULL) { 
 1350                 *mp = m;
 1351                 rip_input(mp, offp, proto);
 1352                 return (IPPROTO_DONE);
 1353         }
 1354         /* Drop the packet */
 1355         m_freem(m);
 1356         return (IPPROTO_DONE);
 1357 }

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