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

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    1 /*-
    2  * Copyright (c) 1982, 1986, 1988, 1990, 1993, 1995
    3  *      The Regents of the University of California.
    4  * Copyright (c) 2008 Robert N. M. Watson
    5  * 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  * 4. 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  *      @(#)udp_usrreq.c        8.6 (Berkeley) 5/23/95
   32  */
   33 
   34 #include <sys/cdefs.h>
   35 __FBSDID("$FreeBSD: releng/8.2/sys/netinet/udp_usrreq.c 211889 2010-08-27 18:50:12Z jhb $");
   36 
   37 #include "opt_ipfw.h"
   38 #include "opt_inet6.h"
   39 #include "opt_ipsec.h"
   40 
   41 #include <sys/param.h>
   42 #include <sys/domain.h>
   43 #include <sys/eventhandler.h>
   44 #include <sys/jail.h>
   45 #include <sys/kernel.h>
   46 #include <sys/lock.h>
   47 #include <sys/malloc.h>
   48 #include <sys/mbuf.h>
   49 #include <sys/priv.h>
   50 #include <sys/proc.h>
   51 #include <sys/protosw.h>
   52 #include <sys/signalvar.h>
   53 #include <sys/socket.h>
   54 #include <sys/socketvar.h>
   55 #include <sys/sx.h>
   56 #include <sys/sysctl.h>
   57 #include <sys/syslog.h>
   58 #include <sys/systm.h>
   59 
   60 #include <vm/uma.h>
   61 
   62 #include <net/if.h>
   63 #include <net/route.h>
   64 
   65 #include <netinet/in.h>
   66 #include <netinet/in_pcb.h>
   67 #include <netinet/in_systm.h>
   68 #include <netinet/in_var.h>
   69 #include <netinet/ip.h>
   70 #ifdef INET6
   71 #include <netinet/ip6.h>
   72 #endif
   73 #include <netinet/ip_icmp.h>
   74 #include <netinet/icmp_var.h>
   75 #include <netinet/ip_var.h>
   76 #include <netinet/ip_options.h>
   77 #ifdef INET6
   78 #include <netinet6/ip6_var.h>
   79 #endif
   80 #include <netinet/udp.h>
   81 #include <netinet/udp_var.h>
   82 
   83 #ifdef IPSEC
   84 #include <netipsec/ipsec.h>
   85 #include <netipsec/esp.h>
   86 #endif
   87 
   88 #include <machine/in_cksum.h>
   89 
   90 #include <security/mac/mac_framework.h>
   91 
   92 /*
   93  * UDP protocol implementation.
   94  * Per RFC 768, August, 1980.
   95  */
   96 
   97 /*
   98  * BSD 4.2 defaulted the udp checksum to be off.  Turning off udp checksums
   99  * removes the only data integrity mechanism for packets and malformed
  100  * packets that would otherwise be discarded due to bad checksums, and may
  101  * cause problems (especially for NFS data blocks).
  102  */
  103 static int      udp_cksum = 1;
  104 SYSCTL_INT(_net_inet_udp, UDPCTL_CHECKSUM, checksum, CTLFLAG_RW, &udp_cksum,
  105     0, "compute udp checksum");
  106 
  107 int     udp_log_in_vain = 0;
  108 SYSCTL_INT(_net_inet_udp, OID_AUTO, log_in_vain, CTLFLAG_RW,
  109     &udp_log_in_vain, 0, "Log all incoming UDP packets");
  110 
  111 VNET_DEFINE(int, udp_blackhole) = 0;
  112 SYSCTL_VNET_INT(_net_inet_udp, OID_AUTO, blackhole, CTLFLAG_RW,
  113     &VNET_NAME(udp_blackhole), 0,
  114     "Do not send port unreachables for refused connects");
  115 
  116 u_long  udp_sendspace = 9216;           /* really max datagram size */
  117                                         /* 40 1K datagrams */
  118 SYSCTL_ULONG(_net_inet_udp, UDPCTL_MAXDGRAM, maxdgram, CTLFLAG_RW,
  119     &udp_sendspace, 0, "Maximum outgoing UDP datagram size");
  120 
  121 u_long  udp_recvspace = 40 * (1024 +
  122 #ifdef INET6
  123                                       sizeof(struct sockaddr_in6)
  124 #else
  125                                       sizeof(struct sockaddr_in)
  126 #endif
  127                                       );
  128 
  129 SYSCTL_ULONG(_net_inet_udp, UDPCTL_RECVSPACE, recvspace, CTLFLAG_RW,
  130     &udp_recvspace, 0, "Maximum space for incoming UDP datagrams");
  131 
  132 VNET_DEFINE(struct inpcbhead, udb);             /* from udp_var.h */
  133 VNET_DEFINE(struct inpcbinfo, udbinfo);
  134 static VNET_DEFINE(uma_zone_t, udpcb_zone);
  135 #define V_udpcb_zone                    VNET(udpcb_zone)
  136 
  137 #ifndef UDBHASHSIZE
  138 #define UDBHASHSIZE     128
  139 #endif
  140 
  141 VNET_DEFINE(struct udpstat, udpstat);           /* from udp_var.h */
  142 SYSCTL_VNET_STRUCT(_net_inet_udp, UDPCTL_STATS, stats, CTLFLAG_RW,
  143     &VNET_NAME(udpstat), udpstat,
  144     "UDP statistics (struct udpstat, netinet/udp_var.h)");
  145 
  146 static void     udp_detach(struct socket *so);
  147 static int      udp_output(struct inpcb *, struct mbuf *, struct sockaddr *,
  148                     struct mbuf *, struct thread *);
  149 #ifdef IPSEC
  150 #ifdef IPSEC_NAT_T
  151 #define UF_ESPINUDP_ALL (UF_ESPINUDP_NON_IKE|UF_ESPINUDP)
  152 #ifdef INET
  153 static struct mbuf *udp4_espdecap(struct inpcb *, struct mbuf *, int);
  154 #endif
  155 #endif /* IPSEC_NAT_T */
  156 #endif /* IPSEC */
  157 
  158 static void
  159 udp_zone_change(void *tag)
  160 {
  161 
  162         uma_zone_set_max(V_udbinfo.ipi_zone, maxsockets);
  163         uma_zone_set_max(V_udpcb_zone, maxsockets);
  164 }
  165 
  166 static int
  167 udp_inpcb_init(void *mem, int size, int flags)
  168 {
  169         struct inpcb *inp;
  170 
  171         inp = mem;
  172         INP_LOCK_INIT(inp, "inp", "udpinp");
  173         return (0);
  174 }
  175 
  176 void
  177 udp_init(void)
  178 {
  179 
  180 
  181         INP_INFO_LOCK_INIT(&V_udbinfo, "udp");
  182         LIST_INIT(&V_udb);
  183 #ifdef VIMAGE
  184         V_udbinfo.ipi_vnet = curvnet;
  185 #endif
  186         V_udbinfo.ipi_listhead = &V_udb;
  187         V_udbinfo.ipi_hashbase = hashinit(UDBHASHSIZE, M_PCB,
  188             &V_udbinfo.ipi_hashmask);
  189         V_udbinfo.ipi_porthashbase = hashinit(UDBHASHSIZE, M_PCB,
  190             &V_udbinfo.ipi_porthashmask);
  191         V_udbinfo.ipi_zone = uma_zcreate("udp_inpcb", sizeof(struct inpcb),
  192             NULL, NULL, udp_inpcb_init, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE);
  193         uma_zone_set_max(V_udbinfo.ipi_zone, maxsockets);
  194 
  195         V_udpcb_zone = uma_zcreate("udpcb", sizeof(struct udpcb),
  196             NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE);
  197         uma_zone_set_max(V_udpcb_zone, maxsockets);
  198 
  199         EVENTHANDLER_REGISTER(maxsockets_change, udp_zone_change, NULL,
  200             EVENTHANDLER_PRI_ANY);
  201 }
  202 
  203 /*
  204  * Kernel module interface for updating udpstat.  The argument is an index
  205  * into udpstat treated as an array of u_long.  While this encodes the
  206  * general layout of udpstat into the caller, it doesn't encode its location,
  207  * so that future changes to add, for example, per-CPU stats support won't
  208  * cause binary compatibility problems for kernel modules.
  209  */
  210 void
  211 kmod_udpstat_inc(int statnum)
  212 {
  213 
  214         (*((u_long *)&V_udpstat + statnum))++;
  215 }
  216 
  217 int
  218 udp_newudpcb(struct inpcb *inp)
  219 {
  220         struct udpcb *up;
  221 
  222         up = uma_zalloc(V_udpcb_zone, M_NOWAIT | M_ZERO);
  223         if (up == NULL)
  224                 return (ENOBUFS);
  225         inp->inp_ppcb = up;
  226         return (0);
  227 }
  228 
  229 void
  230 udp_discardcb(struct udpcb *up)
  231 {
  232 
  233         uma_zfree(V_udpcb_zone, up);
  234 }
  235 
  236 #ifdef VIMAGE
  237 void
  238 udp_destroy(void)
  239 {
  240 
  241         hashdestroy(V_udbinfo.ipi_hashbase, M_PCB,
  242             V_udbinfo.ipi_hashmask);
  243         hashdestroy(V_udbinfo.ipi_porthashbase, M_PCB,
  244             V_udbinfo.ipi_porthashmask);
  245 
  246         uma_zdestroy(V_udpcb_zone);
  247         uma_zdestroy(V_udbinfo.ipi_zone);
  248         INP_INFO_LOCK_DESTROY(&V_udbinfo);
  249 }
  250 #endif
  251 
  252 /*
  253  * Subroutine of udp_input(), which appends the provided mbuf chain to the
  254  * passed pcb/socket.  The caller must provide a sockaddr_in via udp_in that
  255  * contains the source address.  If the socket ends up being an IPv6 socket,
  256  * udp_append() will convert to a sockaddr_in6 before passing the address
  257  * into the socket code.
  258  */
  259 static void
  260 udp_append(struct inpcb *inp, struct ip *ip, struct mbuf *n, int off,
  261     struct sockaddr_in *udp_in)
  262 {
  263         struct sockaddr *append_sa;
  264         struct socket *so;
  265         struct mbuf *opts = 0;
  266 #ifdef INET6
  267         struct sockaddr_in6 udp_in6;
  268 #endif
  269 #ifdef IPSEC
  270 #ifdef IPSEC_NAT_T
  271 #ifdef INET
  272         struct udpcb *up;
  273 #endif
  274 #endif
  275 #endif
  276 
  277         INP_RLOCK_ASSERT(inp);
  278 
  279 #ifdef IPSEC
  280         /* Check AH/ESP integrity. */
  281         if (ipsec4_in_reject(n, inp)) {
  282                 m_freem(n);
  283                 V_ipsec4stat.in_polvio++;
  284                 return;
  285         }
  286 #ifdef IPSEC_NAT_T
  287 #ifdef INET
  288         up = intoudpcb(inp);
  289         KASSERT(up != NULL, ("%s: udpcb NULL", __func__));
  290         if (up->u_flags & UF_ESPINUDP_ALL) {    /* IPSec UDP encaps. */
  291                 n = udp4_espdecap(inp, n, off);
  292                 if (n == NULL)                          /* Consumed. */
  293                         return;
  294         }
  295 #endif /* INET */
  296 #endif /* IPSEC_NAT_T */
  297 #endif /* IPSEC */
  298 #ifdef MAC
  299         if (mac_inpcb_check_deliver(inp, n) != 0) {
  300                 m_freem(n);
  301                 return;
  302         }
  303 #endif
  304         if (inp->inp_flags & INP_CONTROLOPTS ||
  305             inp->inp_socket->so_options & (SO_TIMESTAMP | SO_BINTIME)) {
  306 #ifdef INET6
  307                 if (inp->inp_vflag & INP_IPV6)
  308                         (void)ip6_savecontrol_v4(inp, n, &opts, NULL);
  309                 else
  310 #endif
  311                         ip_savecontrol(inp, &opts, ip, n);
  312         }
  313 #ifdef INET6
  314         if (inp->inp_vflag & INP_IPV6) {
  315                 bzero(&udp_in6, sizeof(udp_in6));
  316                 udp_in6.sin6_len = sizeof(udp_in6);
  317                 udp_in6.sin6_family = AF_INET6;
  318                 in6_sin_2_v4mapsin6(udp_in, &udp_in6);
  319                 append_sa = (struct sockaddr *)&udp_in6;
  320         } else
  321 #endif
  322                 append_sa = (struct sockaddr *)udp_in;
  323         m_adj(n, off);
  324 
  325         so = inp->inp_socket;
  326         SOCKBUF_LOCK(&so->so_rcv);
  327         if (sbappendaddr_locked(&so->so_rcv, append_sa, n, opts) == 0) {
  328                 SOCKBUF_UNLOCK(&so->so_rcv);
  329                 m_freem(n);
  330                 if (opts)
  331                         m_freem(opts);
  332                 UDPSTAT_INC(udps_fullsock);
  333         } else
  334                 sorwakeup_locked(so);
  335 }
  336 
  337 void
  338 udp_input(struct mbuf *m, int off)
  339 {
  340         int iphlen = off;
  341         struct ip *ip;
  342         struct udphdr *uh;
  343         struct ifnet *ifp;
  344         struct inpcb *inp;
  345         struct udpcb *up;
  346         int len;
  347         struct ip save_ip;
  348         struct sockaddr_in udp_in;
  349 #ifdef IPFIREWALL_FORWARD
  350         struct m_tag *fwd_tag;
  351 #endif
  352 
  353         ifp = m->m_pkthdr.rcvif;
  354         UDPSTAT_INC(udps_ipackets);
  355 
  356         /*
  357          * Strip IP options, if any; should skip this, make available to
  358          * user, and use on returned packets, but we don't yet have a way to
  359          * check the checksum with options still present.
  360          */
  361         if (iphlen > sizeof (struct ip)) {
  362                 ip_stripoptions(m, (struct mbuf *)0);
  363                 iphlen = sizeof(struct ip);
  364         }
  365 
  366         /*
  367          * Get IP and UDP header together in first mbuf.
  368          */
  369         ip = mtod(m, struct ip *);
  370         if (m->m_len < iphlen + sizeof(struct udphdr)) {
  371                 if ((m = m_pullup(m, iphlen + sizeof(struct udphdr))) == 0) {
  372                         UDPSTAT_INC(udps_hdrops);
  373                         return;
  374                 }
  375                 ip = mtod(m, struct ip *);
  376         }
  377         uh = (struct udphdr *)((caddr_t)ip + iphlen);
  378 
  379         /*
  380          * Destination port of 0 is illegal, based on RFC768.
  381          */
  382         if (uh->uh_dport == 0)
  383                 goto badunlocked;
  384 
  385         /*
  386          * Construct sockaddr format source address.  Stuff source address
  387          * and datagram in user buffer.
  388          */
  389         bzero(&udp_in, sizeof(udp_in));
  390         udp_in.sin_len = sizeof(udp_in);
  391         udp_in.sin_family = AF_INET;
  392         udp_in.sin_port = uh->uh_sport;
  393         udp_in.sin_addr = ip->ip_src;
  394 
  395         /*
  396          * Make mbuf data length reflect UDP length.  If not enough data to
  397          * reflect UDP length, drop.
  398          */
  399         len = ntohs((u_short)uh->uh_ulen);
  400         if (ip->ip_len != len) {
  401                 if (len > ip->ip_len || len < sizeof(struct udphdr)) {
  402                         UDPSTAT_INC(udps_badlen);
  403                         goto badunlocked;
  404                 }
  405                 m_adj(m, len - ip->ip_len);
  406                 /* ip->ip_len = len; */
  407         }
  408 
  409         /*
  410          * Save a copy of the IP header in case we want restore it for
  411          * sending an ICMP error message in response.
  412          */
  413         if (!V_udp_blackhole)
  414                 save_ip = *ip;
  415         else
  416                 memset(&save_ip, 0, sizeof(save_ip));
  417 
  418         /*
  419          * Checksum extended UDP header and data.
  420          */
  421         if (uh->uh_sum) {
  422                 u_short uh_sum;
  423 
  424                 if (m->m_pkthdr.csum_flags & CSUM_DATA_VALID) {
  425                         if (m->m_pkthdr.csum_flags & CSUM_PSEUDO_HDR)
  426                                 uh_sum = m->m_pkthdr.csum_data;
  427                         else
  428                                 uh_sum = in_pseudo(ip->ip_src.s_addr,
  429                                     ip->ip_dst.s_addr, htonl((u_short)len +
  430                                     m->m_pkthdr.csum_data + IPPROTO_UDP));
  431                         uh_sum ^= 0xffff;
  432                 } else {
  433                         char b[9];
  434 
  435                         bcopy(((struct ipovly *)ip)->ih_x1, b, 9);
  436                         bzero(((struct ipovly *)ip)->ih_x1, 9);
  437                         ((struct ipovly *)ip)->ih_len = uh->uh_ulen;
  438                         uh_sum = in_cksum(m, len + sizeof (struct ip));
  439                         bcopy(b, ((struct ipovly *)ip)->ih_x1, 9);
  440                 }
  441                 if (uh_sum) {
  442                         UDPSTAT_INC(udps_badsum);
  443                         m_freem(m);
  444                         return;
  445                 }
  446         } else
  447                 UDPSTAT_INC(udps_nosum);
  448 
  449 #ifdef IPFIREWALL_FORWARD
  450         /*
  451          * Grab info from PACKET_TAG_IPFORWARD tag prepended to the chain.
  452          */
  453         fwd_tag = m_tag_find(m, PACKET_TAG_IPFORWARD, NULL);
  454         if (fwd_tag != NULL) {
  455                 struct sockaddr_in *next_hop;
  456 
  457                 /*
  458                  * Do the hack.
  459                  */
  460                 next_hop = (struct sockaddr_in *)(fwd_tag + 1);
  461                 ip->ip_dst = next_hop->sin_addr;
  462                 uh->uh_dport = ntohs(next_hop->sin_port);
  463 
  464                 /*
  465                  * Remove the tag from the packet.  We don't need it anymore.
  466                  */
  467                 m_tag_delete(m, fwd_tag);
  468         }
  469 #endif
  470 
  471         INP_INFO_RLOCK(&V_udbinfo);
  472         if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr)) ||
  473             in_broadcast(ip->ip_dst, ifp)) {
  474                 struct inpcb *last;
  475                 struct ip_moptions *imo;
  476 
  477                 last = NULL;
  478                 LIST_FOREACH(inp, &V_udb, inp_list) {
  479                         if (inp->inp_lport != uh->uh_dport)
  480                                 continue;
  481 #ifdef INET6
  482                         if ((inp->inp_vflag & INP_IPV4) == 0)
  483                                 continue;
  484 #endif
  485                         if (inp->inp_laddr.s_addr != INADDR_ANY &&
  486                             inp->inp_laddr.s_addr != ip->ip_dst.s_addr)
  487                                 continue;
  488                         if (inp->inp_faddr.s_addr != INADDR_ANY &&
  489                             inp->inp_faddr.s_addr != ip->ip_src.s_addr)
  490                                 continue;
  491                         if (inp->inp_fport != 0 &&
  492                             inp->inp_fport != uh->uh_sport)
  493                                 continue;
  494 
  495                         INP_RLOCK(inp);
  496 
  497                         /*
  498                          * Handle socket delivery policy for any-source
  499                          * and source-specific multicast. [RFC3678]
  500                          */
  501                         imo = inp->inp_moptions;
  502                         if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr)) &&
  503                             imo != NULL) {
  504                                 struct sockaddr_in       group;
  505                                 int                      blocked;
  506 
  507                                 bzero(&group, sizeof(struct sockaddr_in));
  508                                 group.sin_len = sizeof(struct sockaddr_in);
  509                                 group.sin_family = AF_INET;
  510                                 group.sin_addr = ip->ip_dst;
  511 
  512                                 blocked = imo_multi_filter(imo, ifp,
  513                                         (struct sockaddr *)&group,
  514                                         (struct sockaddr *)&udp_in);
  515                                 if (blocked != MCAST_PASS) {
  516                                         if (blocked == MCAST_NOTGMEMBER)
  517                                                 IPSTAT_INC(ips_notmember);
  518                                         if (blocked == MCAST_NOTSMEMBER ||
  519                                             blocked == MCAST_MUTED)
  520                                                 UDPSTAT_INC(udps_filtermcast);
  521                                         INP_RUNLOCK(inp);
  522                                         continue;
  523                                 }
  524                         }
  525                         if (last != NULL) {
  526                                 struct mbuf *n;
  527 
  528                                 n = m_copy(m, 0, M_COPYALL);
  529                                 up = intoudpcb(last);
  530                                 if (up->u_tun_func == NULL) {
  531                                         if (n != NULL)
  532                                                 udp_append(last, 
  533                                                     ip, n, 
  534                                                     iphlen +
  535                                                     sizeof(struct udphdr),
  536                                                     &udp_in);
  537                                 } else {
  538                                         /*
  539                                          * Engage the tunneling protocol we
  540                                          * will have to leave the info_lock
  541                                          * up, since we are hunting through
  542                                          * multiple UDP's.
  543                                          */
  544 
  545                                         (*up->u_tun_func)(n, iphlen, last);
  546                                 }
  547                                 INP_RUNLOCK(last);
  548                         }
  549                         last = inp;
  550                         /*
  551                          * Don't look for additional matches if this one does
  552                          * not have either the SO_REUSEPORT or SO_REUSEADDR
  553                          * socket options set.  This heuristic avoids
  554                          * searching through all pcbs in the common case of a
  555                          * non-shared port.  It assumes that an application
  556                          * will never clear these options after setting them.
  557                          */
  558                         if ((last->inp_socket->so_options &
  559                             (SO_REUSEPORT|SO_REUSEADDR)) == 0)
  560                                 break;
  561                 }
  562 
  563                 if (last == NULL) {
  564                         /*
  565                          * No matching pcb found; discard datagram.  (No need
  566                          * to send an ICMP Port Unreachable for a broadcast
  567                          * or multicast datgram.)
  568                          */
  569                         UDPSTAT_INC(udps_noportbcast);
  570                         goto badheadlocked;
  571                 }
  572                 up = intoudpcb(last);
  573                 if (up->u_tun_func == NULL) {
  574                         udp_append(last, ip, m, iphlen + sizeof(struct udphdr),
  575                             &udp_in);
  576                 } else {
  577                         /*
  578                          * Engage the tunneling protocol.
  579                          */
  580                         (*up->u_tun_func)(m, iphlen, last);
  581                 }
  582                 INP_RUNLOCK(last);
  583                 INP_INFO_RUNLOCK(&V_udbinfo);
  584                 return;
  585         }
  586 
  587         /*
  588          * Locate pcb for datagram.
  589          */
  590         inp = in_pcblookup_hash(&V_udbinfo, ip->ip_src, uh->uh_sport,
  591             ip->ip_dst, uh->uh_dport, 1, ifp);
  592         if (inp == NULL) {
  593                 if (udp_log_in_vain) {
  594                         char buf[4*sizeof "123"];
  595 
  596                         strcpy(buf, inet_ntoa(ip->ip_dst));
  597                         log(LOG_INFO,
  598                             "Connection attempt to UDP %s:%d from %s:%d\n",
  599                             buf, ntohs(uh->uh_dport), inet_ntoa(ip->ip_src),
  600                             ntohs(uh->uh_sport));
  601                 }
  602                 UDPSTAT_INC(udps_noport);
  603                 if (m->m_flags & (M_BCAST | M_MCAST)) {
  604                         UDPSTAT_INC(udps_noportbcast);
  605                         goto badheadlocked;
  606                 }
  607                 if (V_udp_blackhole)
  608                         goto badheadlocked;
  609                 if (badport_bandlim(BANDLIM_ICMP_UNREACH) < 0)
  610                         goto badheadlocked;
  611                 *ip = save_ip;
  612                 ip->ip_len += iphlen;
  613                 icmp_error(m, ICMP_UNREACH, ICMP_UNREACH_PORT, 0, 0);
  614                 INP_INFO_RUNLOCK(&V_udbinfo);
  615                 return;
  616         }
  617 
  618         /*
  619          * Check the minimum TTL for socket.
  620          */
  621         INP_RLOCK(inp);
  622         INP_INFO_RUNLOCK(&V_udbinfo);
  623         if (inp->inp_ip_minttl && inp->inp_ip_minttl > ip->ip_ttl) {
  624                 INP_RUNLOCK(inp);
  625                 goto badunlocked;
  626         }
  627         up = intoudpcb(inp);
  628         if (up->u_tun_func == NULL) {
  629                 udp_append(inp, ip, m, iphlen + sizeof(struct udphdr), &udp_in);
  630         } else {
  631                 /*
  632                  * Engage the tunneling protocol.
  633                  */
  634 
  635                 (*up->u_tun_func)(m, iphlen, inp);
  636         }
  637         INP_RUNLOCK(inp);
  638         return;
  639 
  640 badheadlocked:
  641         if (inp)
  642                 INP_RUNLOCK(inp);
  643         INP_INFO_RUNLOCK(&V_udbinfo);
  644 badunlocked:
  645         m_freem(m);
  646 }
  647 
  648 /*
  649  * Notify a udp user of an asynchronous error; just wake up so that they can
  650  * collect error status.
  651  */
  652 struct inpcb *
  653 udp_notify(struct inpcb *inp, int errno)
  654 {
  655 
  656         /*
  657          * While udp_ctlinput() always calls udp_notify() with a read lock
  658          * when invoking it directly, in_pcbnotifyall() currently uses write
  659          * locks due to sharing code with TCP.  For now, accept either a read
  660          * or a write lock, but a read lock is sufficient.
  661          */
  662         INP_LOCK_ASSERT(inp);
  663 
  664         inp->inp_socket->so_error = errno;
  665         sorwakeup(inp->inp_socket);
  666         sowwakeup(inp->inp_socket);
  667         return (inp);
  668 }
  669 
  670 void
  671 udp_ctlinput(int cmd, struct sockaddr *sa, void *vip)
  672 {
  673         struct ip *ip = vip;
  674         struct udphdr *uh;
  675         struct in_addr faddr;
  676         struct inpcb *inp;
  677 
  678         faddr = ((struct sockaddr_in *)sa)->sin_addr;
  679         if (sa->sa_family != AF_INET || faddr.s_addr == INADDR_ANY)
  680                 return;
  681 
  682         /*
  683          * Redirects don't need to be handled up here.
  684          */
  685         if (PRC_IS_REDIRECT(cmd))
  686                 return;
  687 
  688         /*
  689          * Hostdead is ugly because it goes linearly through all PCBs.
  690          *
  691          * XXX: We never get this from ICMP, otherwise it makes an excellent
  692          * DoS attack on machines with many connections.
  693          */
  694         if (cmd == PRC_HOSTDEAD)
  695                 ip = NULL;
  696         else if ((unsigned)cmd >= PRC_NCMDS || inetctlerrmap[cmd] == 0)
  697                 return;
  698         if (ip != NULL) {
  699                 uh = (struct udphdr *)((caddr_t)ip + (ip->ip_hl << 2));
  700                 INP_INFO_RLOCK(&V_udbinfo);
  701                 inp = in_pcblookup_hash(&V_udbinfo, faddr, uh->uh_dport,
  702                     ip->ip_src, uh->uh_sport, 0, NULL);
  703                 if (inp != NULL) {
  704                         INP_RLOCK(inp);
  705                         if (inp->inp_socket != NULL) {
  706                                 udp_notify(inp, inetctlerrmap[cmd]);
  707                         }
  708                         INP_RUNLOCK(inp);
  709                 }
  710                 INP_INFO_RUNLOCK(&V_udbinfo);
  711         } else
  712                 in_pcbnotifyall(&V_udbinfo, faddr, inetctlerrmap[cmd],
  713                     udp_notify);
  714 }
  715 
  716 static int
  717 udp_pcblist(SYSCTL_HANDLER_ARGS)
  718 {
  719         int error, i, n;
  720         struct inpcb *inp, **inp_list;
  721         inp_gen_t gencnt;
  722         struct xinpgen xig;
  723 
  724         /*
  725          * The process of preparing the PCB list is too time-consuming and
  726          * resource-intensive to repeat twice on every request.
  727          */
  728         if (req->oldptr == 0) {
  729                 n = V_udbinfo.ipi_count;
  730                 n += imax(n / 8, 10);
  731                 req->oldidx = 2 * (sizeof xig) + n * sizeof(struct xinpcb);
  732                 return (0);
  733         }
  734 
  735         if (req->newptr != 0)
  736                 return (EPERM);
  737 
  738         /*
  739          * OK, now we're committed to doing something.
  740          */
  741         INP_INFO_RLOCK(&V_udbinfo);
  742         gencnt = V_udbinfo.ipi_gencnt;
  743         n = V_udbinfo.ipi_count;
  744         INP_INFO_RUNLOCK(&V_udbinfo);
  745 
  746         error = sysctl_wire_old_buffer(req, 2 * (sizeof xig)
  747                 + n * sizeof(struct xinpcb));
  748         if (error != 0)
  749                 return (error);
  750 
  751         xig.xig_len = sizeof xig;
  752         xig.xig_count = n;
  753         xig.xig_gen = gencnt;
  754         xig.xig_sogen = so_gencnt;
  755         error = SYSCTL_OUT(req, &xig, sizeof xig);
  756         if (error)
  757                 return (error);
  758 
  759         inp_list = malloc(n * sizeof *inp_list, M_TEMP, M_WAITOK);
  760         if (inp_list == 0)
  761                 return (ENOMEM);
  762 
  763         INP_INFO_RLOCK(&V_udbinfo);
  764         for (inp = LIST_FIRST(V_udbinfo.ipi_listhead), i = 0; inp && i < n;
  765              inp = LIST_NEXT(inp, inp_list)) {
  766                 INP_WLOCK(inp);
  767                 if (inp->inp_gencnt <= gencnt &&
  768                     cr_canseeinpcb(req->td->td_ucred, inp) == 0) {
  769                         in_pcbref(inp);
  770                         inp_list[i++] = inp;
  771                 }
  772                 INP_WUNLOCK(inp);
  773         }
  774         INP_INFO_RUNLOCK(&V_udbinfo);
  775         n = i;
  776 
  777         error = 0;
  778         for (i = 0; i < n; i++) {
  779                 inp = inp_list[i];
  780                 INP_RLOCK(inp);
  781                 if (inp->inp_gencnt <= gencnt) {
  782                         struct xinpcb xi;
  783 
  784                         bzero(&xi, sizeof(xi));
  785                         xi.xi_len = sizeof xi;
  786                         /* XXX should avoid extra copy */
  787                         bcopy(inp, &xi.xi_inp, sizeof *inp);
  788                         if (inp->inp_socket)
  789                                 sotoxsocket(inp->inp_socket, &xi.xi_socket);
  790                         xi.xi_inp.inp_gencnt = inp->inp_gencnt;
  791                         INP_RUNLOCK(inp);
  792                         error = SYSCTL_OUT(req, &xi, sizeof xi);
  793                 } else
  794                         INP_RUNLOCK(inp);
  795         }
  796         INP_INFO_WLOCK(&V_udbinfo);
  797         for (i = 0; i < n; i++) {
  798                 inp = inp_list[i];
  799                 INP_WLOCK(inp);
  800                 if (!in_pcbrele(inp))
  801                         INP_WUNLOCK(inp);
  802         }
  803         INP_INFO_WUNLOCK(&V_udbinfo);
  804 
  805         if (!error) {
  806                 /*
  807                  * Give the user an updated idea of our state.  If the
  808                  * generation differs from what we told her before, she knows
  809                  * that something happened while we were processing this
  810                  * request, and it might be necessary to retry.
  811                  */
  812                 INP_INFO_RLOCK(&V_udbinfo);
  813                 xig.xig_gen = V_udbinfo.ipi_gencnt;
  814                 xig.xig_sogen = so_gencnt;
  815                 xig.xig_count = V_udbinfo.ipi_count;
  816                 INP_INFO_RUNLOCK(&V_udbinfo);
  817                 error = SYSCTL_OUT(req, &xig, sizeof xig);
  818         }
  819         free(inp_list, M_TEMP);
  820         return (error);
  821 }
  822 
  823 SYSCTL_PROC(_net_inet_udp, UDPCTL_PCBLIST, pcblist, CTLFLAG_RD, 0, 0,
  824     udp_pcblist, "S,xinpcb", "List of active UDP sockets");
  825 
  826 static int
  827 udp_getcred(SYSCTL_HANDLER_ARGS)
  828 {
  829         struct xucred xuc;
  830         struct sockaddr_in addrs[2];
  831         struct inpcb *inp;
  832         int error;
  833 
  834         error = priv_check(req->td, PRIV_NETINET_GETCRED);
  835         if (error)
  836                 return (error);
  837         error = SYSCTL_IN(req, addrs, sizeof(addrs));
  838         if (error)
  839                 return (error);
  840         INP_INFO_RLOCK(&V_udbinfo);
  841         inp = in_pcblookup_hash(&V_udbinfo, addrs[1].sin_addr, addrs[1].sin_port,
  842                                 addrs[0].sin_addr, addrs[0].sin_port, 1, NULL);
  843         if (inp != NULL) {
  844                 INP_RLOCK(inp);
  845                 INP_INFO_RUNLOCK(&V_udbinfo);
  846                 if (inp->inp_socket == NULL)
  847                         error = ENOENT;
  848                 if (error == 0)
  849                         error = cr_canseeinpcb(req->td->td_ucred, inp);
  850                 if (error == 0)
  851                         cru2x(inp->inp_cred, &xuc);
  852                 INP_RUNLOCK(inp);
  853         } else {
  854                 INP_INFO_RUNLOCK(&V_udbinfo);
  855                 error = ENOENT;
  856         }
  857         if (error == 0)
  858                 error = SYSCTL_OUT(req, &xuc, sizeof(struct xucred));
  859         return (error);
  860 }
  861 
  862 SYSCTL_PROC(_net_inet_udp, OID_AUTO, getcred,
  863     CTLTYPE_OPAQUE|CTLFLAG_RW|CTLFLAG_PRISON, 0, 0,
  864     udp_getcred, "S,xucred", "Get the xucred of a UDP connection");
  865 
  866 int
  867 udp_ctloutput(struct socket *so, struct sockopt *sopt)
  868 {
  869         int error = 0, optval;
  870         struct inpcb *inp;
  871 #ifdef IPSEC_NAT_T
  872         struct udpcb *up;
  873 #endif
  874 
  875         inp = sotoinpcb(so);
  876         KASSERT(inp != NULL, ("%s: inp == NULL", __func__));
  877         INP_WLOCK(inp);
  878         if (sopt->sopt_level != IPPROTO_UDP) {
  879 #ifdef INET6
  880                 if (INP_CHECK_SOCKAF(so, AF_INET6)) {
  881                         INP_WUNLOCK(inp);
  882                         error = ip6_ctloutput(so, sopt);
  883                 } else {
  884 #endif
  885                         INP_WUNLOCK(inp);
  886                         error = ip_ctloutput(so, sopt);
  887 #ifdef INET6
  888                 }
  889 #endif
  890                 return (error);
  891         }
  892 
  893         switch (sopt->sopt_dir) {
  894         case SOPT_SET:
  895                 switch (sopt->sopt_name) {
  896                 case UDP_ENCAP:
  897                         INP_WUNLOCK(inp);
  898                         error = sooptcopyin(sopt, &optval, sizeof optval,
  899                                             sizeof optval);
  900                         if (error)
  901                                 break;
  902                         inp = sotoinpcb(so);
  903                         KASSERT(inp != NULL, ("%s: inp == NULL", __func__));
  904                         INP_WLOCK(inp);
  905 #ifdef IPSEC_NAT_T
  906                         up = intoudpcb(inp);
  907                         KASSERT(up != NULL, ("%s: up == NULL", __func__));
  908 #endif
  909                         switch (optval) {
  910                         case 0:
  911                                 /* Clear all UDP encap. */
  912 #ifdef IPSEC_NAT_T
  913                                 up->u_flags &= ~UF_ESPINUDP_ALL;
  914 #endif
  915                                 break;
  916 #ifdef IPSEC_NAT_T
  917                         case UDP_ENCAP_ESPINUDP:
  918                         case UDP_ENCAP_ESPINUDP_NON_IKE:
  919                                 up->u_flags &= ~UF_ESPINUDP_ALL;
  920                                 if (optval == UDP_ENCAP_ESPINUDP)
  921                                         up->u_flags |= UF_ESPINUDP;
  922                                 else if (optval == UDP_ENCAP_ESPINUDP_NON_IKE)
  923                                         up->u_flags |= UF_ESPINUDP_NON_IKE;
  924                                 break;
  925 #endif
  926                         default:
  927                                 error = EINVAL;
  928                                 break;
  929                         }
  930                         INP_WUNLOCK(inp);
  931                         break;
  932                 default:
  933                         INP_WUNLOCK(inp);
  934                         error = ENOPROTOOPT;
  935                         break;
  936                 }
  937                 break;
  938         case SOPT_GET:
  939                 switch (sopt->sopt_name) {
  940 #ifdef IPSEC_NAT_T
  941                 case UDP_ENCAP:
  942                         up = intoudpcb(inp);
  943                         KASSERT(up != NULL, ("%s: up == NULL", __func__));
  944                         optval = up->u_flags & UF_ESPINUDP_ALL;
  945                         INP_WUNLOCK(inp);
  946                         error = sooptcopyout(sopt, &optval, sizeof optval);
  947                         break;
  948 #endif
  949                 default:
  950                         INP_WUNLOCK(inp);
  951                         error = ENOPROTOOPT;
  952                         break;
  953                 }
  954                 break;
  955         }       
  956         return (error);
  957 }
  958 
  959 static int
  960 udp_output(struct inpcb *inp, struct mbuf *m, struct sockaddr *addr,
  961     struct mbuf *control, struct thread *td)
  962 {
  963         struct udpiphdr *ui;
  964         int len = m->m_pkthdr.len;
  965         struct in_addr faddr, laddr;
  966         struct cmsghdr *cm;
  967         struct sockaddr_in *sin, src;
  968         int error = 0;
  969         int ipflags;
  970         u_short fport, lport;
  971         int unlock_udbinfo;
  972 
  973         /*
  974          * udp_output() may need to temporarily bind or connect the current
  975          * inpcb.  As such, we don't know up front whether we will need the
  976          * pcbinfo lock or not.  Do any work to decide what is needed up
  977          * front before acquiring any locks.
  978          */
  979         if (len + sizeof(struct udpiphdr) > IP_MAXPACKET) {
  980                 if (control)
  981                         m_freem(control);
  982                 m_freem(m);
  983                 return (EMSGSIZE);
  984         }
  985 
  986         src.sin_family = 0;
  987         if (control != NULL) {
  988                 /*
  989                  * XXX: Currently, we assume all the optional information is
  990                  * stored in a single mbuf.
  991                  */
  992                 if (control->m_next) {
  993                         m_freem(control);
  994                         m_freem(m);
  995                         return (EINVAL);
  996                 }
  997                 for (; control->m_len > 0;
  998                     control->m_data += CMSG_ALIGN(cm->cmsg_len),
  999                     control->m_len -= CMSG_ALIGN(cm->cmsg_len)) {
 1000                         cm = mtod(control, struct cmsghdr *);
 1001                         if (control->m_len < sizeof(*cm) || cm->cmsg_len == 0
 1002                             || cm->cmsg_len > control->m_len) {
 1003                                 error = EINVAL;
 1004                                 break;
 1005                         }
 1006                         if (cm->cmsg_level != IPPROTO_IP)
 1007                                 continue;
 1008 
 1009                         switch (cm->cmsg_type) {
 1010                         case IP_SENDSRCADDR:
 1011                                 if (cm->cmsg_len !=
 1012                                     CMSG_LEN(sizeof(struct in_addr))) {
 1013                                         error = EINVAL;
 1014                                         break;
 1015                                 }
 1016                                 bzero(&src, sizeof(src));
 1017                                 src.sin_family = AF_INET;
 1018                                 src.sin_len = sizeof(src);
 1019                                 src.sin_port = inp->inp_lport;
 1020                                 src.sin_addr =
 1021                                     *(struct in_addr *)CMSG_DATA(cm);
 1022                                 break;
 1023 
 1024                         default:
 1025                                 error = ENOPROTOOPT;
 1026                                 break;
 1027                         }
 1028                         if (error)
 1029                                 break;
 1030                 }
 1031                 m_freem(control);
 1032         }
 1033         if (error) {
 1034                 m_freem(m);
 1035                 return (error);
 1036         }
 1037 
 1038         /*
 1039          * Depending on whether or not the application has bound or connected
 1040          * the socket, we may have to do varying levels of work.  The optimal
 1041          * case is for a connected UDP socket, as a global lock isn't
 1042          * required at all.
 1043          *
 1044          * In order to decide which we need, we require stability of the
 1045          * inpcb binding, which we ensure by acquiring a read lock on the
 1046          * inpcb.  This doesn't strictly follow the lock order, so we play
 1047          * the trylock and retry game; note that we may end up with more
 1048          * conservative locks than required the second time around, so later
 1049          * assertions have to accept that.  Further analysis of the number of
 1050          * misses under contention is required.
 1051          */
 1052         sin = (struct sockaddr_in *)addr;
 1053         INP_RLOCK(inp);
 1054         if (sin != NULL &&
 1055             (inp->inp_laddr.s_addr == INADDR_ANY && inp->inp_lport == 0)) {
 1056                 INP_RUNLOCK(inp);
 1057                 INP_INFO_WLOCK(&V_udbinfo);
 1058                 INP_WLOCK(inp);
 1059                 unlock_udbinfo = 2;
 1060         } else if ((sin != NULL && (
 1061             (sin->sin_addr.s_addr == INADDR_ANY) ||
 1062             (sin->sin_addr.s_addr == INADDR_BROADCAST) ||
 1063             (inp->inp_laddr.s_addr == INADDR_ANY) ||
 1064             (inp->inp_lport == 0))) ||
 1065             (src.sin_family == AF_INET)) {
 1066                 if (!INP_INFO_TRY_RLOCK(&V_udbinfo)) {
 1067                         INP_RUNLOCK(inp);
 1068                         INP_INFO_RLOCK(&V_udbinfo);
 1069                         INP_RLOCK(inp);
 1070                 }
 1071                 unlock_udbinfo = 1;
 1072         } else
 1073                 unlock_udbinfo = 0;
 1074 
 1075         /*
 1076          * If the IP_SENDSRCADDR control message was specified, override the
 1077          * source address for this datagram.  Its use is invalidated if the
 1078          * address thus specified is incomplete or clobbers other inpcbs.
 1079          */
 1080         laddr = inp->inp_laddr;
 1081         lport = inp->inp_lport;
 1082         if (src.sin_family == AF_INET) {
 1083                 INP_INFO_LOCK_ASSERT(&V_udbinfo);
 1084                 if ((lport == 0) ||
 1085                     (laddr.s_addr == INADDR_ANY &&
 1086                      src.sin_addr.s_addr == INADDR_ANY)) {
 1087                         error = EINVAL;
 1088                         goto release;
 1089                 }
 1090                 error = in_pcbbind_setup(inp, (struct sockaddr *)&src,
 1091                     &laddr.s_addr, &lport, td->td_ucred);
 1092                 if (error)
 1093                         goto release;
 1094         }
 1095 
 1096         /*
 1097          * If a UDP socket has been connected, then a local address/port will
 1098          * have been selected and bound.
 1099          *
 1100          * If a UDP socket has not been connected to, then an explicit
 1101          * destination address must be used, in which case a local
 1102          * address/port may not have been selected and bound.
 1103          */
 1104         if (sin != NULL) {
 1105                 INP_LOCK_ASSERT(inp);
 1106                 if (inp->inp_faddr.s_addr != INADDR_ANY) {
 1107                         error = EISCONN;
 1108                         goto release;
 1109                 }
 1110 
 1111                 /*
 1112                  * Jail may rewrite the destination address, so let it do
 1113                  * that before we use it.
 1114                  */
 1115                 error = prison_remote_ip4(td->td_ucred, &sin->sin_addr);
 1116                 if (error)
 1117                         goto release;
 1118 
 1119                 /*
 1120                  * If a local address or port hasn't yet been selected, or if
 1121                  * the destination address needs to be rewritten due to using
 1122                  * a special INADDR_ constant, invoke in_pcbconnect_setup()
 1123                  * to do the heavy lifting.  Once a port is selected, we
 1124                  * commit the binding back to the socket; we also commit the
 1125                  * binding of the address if in jail.
 1126                  *
 1127                  * If we already have a valid binding and we're not
 1128                  * requesting a destination address rewrite, use a fast path.
 1129                  */
 1130                 if (inp->inp_laddr.s_addr == INADDR_ANY ||
 1131                     inp->inp_lport == 0 ||
 1132                     sin->sin_addr.s_addr == INADDR_ANY ||
 1133                     sin->sin_addr.s_addr == INADDR_BROADCAST) {
 1134                         INP_INFO_LOCK_ASSERT(&V_udbinfo);
 1135                         error = in_pcbconnect_setup(inp, addr, &laddr.s_addr,
 1136                             &lport, &faddr.s_addr, &fport, NULL,
 1137                             td->td_ucred);
 1138                         if (error)
 1139                                 goto release;
 1140 
 1141                         /*
 1142                          * XXXRW: Why not commit the port if the address is
 1143                          * !INADDR_ANY?
 1144                          */
 1145                         /* Commit the local port if newly assigned. */
 1146                         if (inp->inp_laddr.s_addr == INADDR_ANY &&
 1147                             inp->inp_lport == 0) {
 1148                                 INP_INFO_WLOCK_ASSERT(&V_udbinfo);
 1149                                 INP_WLOCK_ASSERT(inp);
 1150                                 /*
 1151                                  * Remember addr if jailed, to prevent
 1152                                  * rebinding.
 1153                                  */
 1154                                 if (prison_flag(td->td_ucred, PR_IP4))
 1155                                         inp->inp_laddr = laddr;
 1156                                 inp->inp_lport = lport;
 1157                                 if (in_pcbinshash(inp) != 0) {
 1158                                         inp->inp_lport = 0;
 1159                                         error = EAGAIN;
 1160                                         goto release;
 1161                                 }
 1162                                 inp->inp_flags |= INP_ANONPORT;
 1163                         }
 1164                 } else {
 1165                         faddr = sin->sin_addr;
 1166                         fport = sin->sin_port;
 1167                 }
 1168         } else {
 1169                 INP_LOCK_ASSERT(inp);
 1170                 faddr = inp->inp_faddr;
 1171                 fport = inp->inp_fport;
 1172                 if (faddr.s_addr == INADDR_ANY) {
 1173                         error = ENOTCONN;
 1174                         goto release;
 1175                 }
 1176         }
 1177 
 1178         /*
 1179          * Calculate data length and get a mbuf for UDP, IP, and possible
 1180          * link-layer headers.  Immediate slide the data pointer back forward
 1181          * since we won't use that space at this layer.
 1182          */
 1183         M_PREPEND(m, sizeof(struct udpiphdr) + max_linkhdr, M_DONTWAIT);
 1184         if (m == NULL) {
 1185                 error = ENOBUFS;
 1186                 goto release;
 1187         }
 1188         m->m_data += max_linkhdr;
 1189         m->m_len -= max_linkhdr;
 1190         m->m_pkthdr.len -= max_linkhdr;
 1191 
 1192         /*
 1193          * Fill in mbuf with extended UDP header and addresses and length put
 1194          * into network format.
 1195          */
 1196         ui = mtod(m, struct udpiphdr *);
 1197         bzero(ui->ui_x1, sizeof(ui->ui_x1));    /* XXX still needed? */
 1198         ui->ui_pr = IPPROTO_UDP;
 1199         ui->ui_src = laddr;
 1200         ui->ui_dst = faddr;
 1201         ui->ui_sport = lport;
 1202         ui->ui_dport = fport;
 1203         ui->ui_ulen = htons((u_short)len + sizeof(struct udphdr));
 1204 
 1205         /*
 1206          * Set the Don't Fragment bit in the IP header.
 1207          */
 1208         if (inp->inp_flags & INP_DONTFRAG) {
 1209                 struct ip *ip;
 1210 
 1211                 ip = (struct ip *)&ui->ui_i;
 1212                 ip->ip_off |= IP_DF;
 1213         }
 1214 
 1215         ipflags = 0;
 1216         if (inp->inp_socket->so_options & SO_DONTROUTE)
 1217                 ipflags |= IP_ROUTETOIF;
 1218         if (inp->inp_socket->so_options & SO_BROADCAST)
 1219                 ipflags |= IP_ALLOWBROADCAST;
 1220         if (inp->inp_flags & INP_ONESBCAST)
 1221                 ipflags |= IP_SENDONES;
 1222 
 1223 #ifdef MAC
 1224         mac_inpcb_create_mbuf(inp, m);
 1225 #endif
 1226 
 1227         /*
 1228          * Set up checksum and output datagram.
 1229          */
 1230         if (udp_cksum) {
 1231                 if (inp->inp_flags & INP_ONESBCAST)
 1232                         faddr.s_addr = INADDR_BROADCAST;
 1233                 ui->ui_sum = in_pseudo(ui->ui_src.s_addr, faddr.s_addr,
 1234                     htons((u_short)len + sizeof(struct udphdr) + IPPROTO_UDP));
 1235                 m->m_pkthdr.csum_flags = CSUM_UDP;
 1236                 m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum);
 1237         } else
 1238                 ui->ui_sum = 0;
 1239         ((struct ip *)ui)->ip_len = sizeof (struct udpiphdr) + len;
 1240         ((struct ip *)ui)->ip_ttl = inp->inp_ip_ttl;    /* XXX */
 1241         ((struct ip *)ui)->ip_tos = inp->inp_ip_tos;    /* XXX */
 1242         UDPSTAT_INC(udps_opackets);
 1243 
 1244         if (unlock_udbinfo == 2)
 1245                 INP_INFO_WUNLOCK(&V_udbinfo);
 1246         else if (unlock_udbinfo == 1)
 1247                 INP_INFO_RUNLOCK(&V_udbinfo);
 1248         error = ip_output(m, inp->inp_options, NULL, ipflags,
 1249             inp->inp_moptions, inp);
 1250         if (unlock_udbinfo == 2)
 1251                 INP_WUNLOCK(inp);
 1252         else
 1253                 INP_RUNLOCK(inp);
 1254         return (error);
 1255 
 1256 release:
 1257         if (unlock_udbinfo == 2) {
 1258                 INP_WUNLOCK(inp);
 1259                 INP_INFO_WUNLOCK(&V_udbinfo);
 1260         } else if (unlock_udbinfo == 1) {
 1261                 INP_RUNLOCK(inp);
 1262                 INP_INFO_RUNLOCK(&V_udbinfo);
 1263         } else
 1264                 INP_RUNLOCK(inp);
 1265         m_freem(m);
 1266         return (error);
 1267 }
 1268 
 1269 
 1270 #if defined(IPSEC) && defined(IPSEC_NAT_T)
 1271 #ifdef INET
 1272 /*
 1273  * Potentially decap ESP in UDP frame.  Check for an ESP header
 1274  * and optional marker; if present, strip the UDP header and
 1275  * push the result through IPSec.
 1276  *
 1277  * Returns mbuf to be processed (potentially re-allocated) or
 1278  * NULL if consumed and/or processed.
 1279  */
 1280 static struct mbuf *
 1281 udp4_espdecap(struct inpcb *inp, struct mbuf *m, int off)
 1282 {
 1283         size_t minlen, payload, skip, iphlen;
 1284         caddr_t data;
 1285         struct udpcb *up;
 1286         struct m_tag *tag;
 1287         struct udphdr *udphdr;
 1288         struct ip *ip;
 1289 
 1290         INP_RLOCK_ASSERT(inp);
 1291 
 1292         /* 
 1293          * Pull up data so the longest case is contiguous:
 1294          *    IP/UDP hdr + non ESP marker + ESP hdr.
 1295          */
 1296         minlen = off + sizeof(uint64_t) + sizeof(struct esp);
 1297         if (minlen > m->m_pkthdr.len)
 1298                 minlen = m->m_pkthdr.len;
 1299         if ((m = m_pullup(m, minlen)) == NULL) {
 1300                 V_ipsec4stat.in_inval++;
 1301                 return (NULL);          /* Bypass caller processing. */
 1302         }
 1303         data = mtod(m, caddr_t);        /* Points to ip header. */
 1304         payload = m->m_len - off;       /* Size of payload. */
 1305 
 1306         if (payload == 1 && data[off] == '\xff')
 1307                 return (m);             /* NB: keepalive packet, no decap. */
 1308 
 1309         up = intoudpcb(inp);
 1310         KASSERT(up != NULL, ("%s: udpcb NULL", __func__));
 1311         KASSERT((up->u_flags & UF_ESPINUDP_ALL) != 0,
 1312             ("u_flags 0x%x", up->u_flags));
 1313 
 1314         /* 
 1315          * Check that the payload is large enough to hold an
 1316          * ESP header and compute the amount of data to remove.
 1317          *
 1318          * NB: the caller has already done a pullup for us.
 1319          * XXX can we assume alignment and eliminate bcopys?
 1320          */
 1321         if (up->u_flags & UF_ESPINUDP_NON_IKE) {
 1322                 /*
 1323                  * draft-ietf-ipsec-nat-t-ike-0[01].txt and
 1324                  * draft-ietf-ipsec-udp-encaps-(00/)01.txt, ignoring
 1325                  * possible AH mode non-IKE marker+non-ESP marker
 1326                  * from draft-ietf-ipsec-udp-encaps-00.txt.
 1327                  */
 1328                 uint64_t marker;
 1329 
 1330                 if (payload <= sizeof(uint64_t) + sizeof(struct esp))
 1331                         return (m);     /* NB: no decap. */
 1332                 bcopy(data + off, &marker, sizeof(uint64_t));
 1333                 if (marker != 0)        /* Non-IKE marker. */
 1334                         return (m);     /* NB: no decap. */
 1335                 skip = sizeof(uint64_t) + sizeof(struct udphdr);
 1336         } else {
 1337                 uint32_t spi;
 1338 
 1339                 if (payload <= sizeof(struct esp)) {
 1340                         V_ipsec4stat.in_inval++;
 1341                         m_freem(m);
 1342                         return (NULL);  /* Discard. */
 1343                 }
 1344                 bcopy(data + off, &spi, sizeof(uint32_t));
 1345                 if (spi == 0)           /* Non-ESP marker. */
 1346                         return (m);     /* NB: no decap. */
 1347                 skip = sizeof(struct udphdr);
 1348         }
 1349 
 1350         /*
 1351          * Setup a PACKET_TAG_IPSEC_NAT_T_PORT tag to remember
 1352          * the UDP ports. This is required if we want to select
 1353          * the right SPD for multiple hosts behind same NAT.
 1354          *
 1355          * NB: ports are maintained in network byte order everywhere
 1356          *     in the NAT-T code.
 1357          */
 1358         tag = m_tag_get(PACKET_TAG_IPSEC_NAT_T_PORTS,
 1359                 2 * sizeof(uint16_t), M_NOWAIT);
 1360         if (tag == NULL) {
 1361                 V_ipsec4stat.in_nomem++;
 1362                 m_freem(m);
 1363                 return (NULL);          /* Discard. */
 1364         }
 1365         iphlen = off - sizeof(struct udphdr);
 1366         udphdr = (struct udphdr *)(data + iphlen);
 1367         ((uint16_t *)(tag + 1))[0] = udphdr->uh_sport;
 1368         ((uint16_t *)(tag + 1))[1] = udphdr->uh_dport;
 1369         m_tag_prepend(m, tag);
 1370 
 1371         /*
 1372          * Remove the UDP header (and possibly the non ESP marker)
 1373          * IP header length is iphlen
 1374          * Before:
 1375          *   <--- off --->
 1376          *   +----+------+-----+
 1377          *   | IP |  UDP | ESP |
 1378          *   +----+------+-----+
 1379          *        <-skip->
 1380          * After:
 1381          *          +----+-----+
 1382          *          | IP | ESP |
 1383          *          +----+-----+
 1384          *   <-skip->
 1385          */
 1386         ovbcopy(data, data + skip, iphlen);
 1387         m_adj(m, skip);
 1388 
 1389         ip = mtod(m, struct ip *);
 1390         ip->ip_len -= skip;
 1391         ip->ip_p = IPPROTO_ESP;
 1392 
 1393         /*
 1394          * We cannot yet update the cksums so clear any
 1395          * h/w cksum flags as they are no longer valid.
 1396          */
 1397         if (m->m_pkthdr.csum_flags & CSUM_DATA_VALID)
 1398                 m->m_pkthdr.csum_flags &= ~(CSUM_DATA_VALID|CSUM_PSEUDO_HDR);
 1399 
 1400         (void) ipsec4_common_input(m, iphlen, ip->ip_p);
 1401         return (NULL);                  /* NB: consumed, bypass processing. */
 1402 }
 1403 #endif /* INET */
 1404 #endif /* defined(IPSEC) && defined(IPSEC_NAT_T) */
 1405 
 1406 static void
 1407 udp_abort(struct socket *so)
 1408 {
 1409         struct inpcb *inp;
 1410 
 1411         inp = sotoinpcb(so);
 1412         KASSERT(inp != NULL, ("udp_abort: inp == NULL"));
 1413         INP_INFO_WLOCK(&V_udbinfo);
 1414         INP_WLOCK(inp);
 1415         if (inp->inp_faddr.s_addr != INADDR_ANY) {
 1416                 in_pcbdisconnect(inp);
 1417                 inp->inp_laddr.s_addr = INADDR_ANY;
 1418                 soisdisconnected(so);
 1419         }
 1420         INP_WUNLOCK(inp);
 1421         INP_INFO_WUNLOCK(&V_udbinfo);
 1422 }
 1423 
 1424 static int
 1425 udp_attach(struct socket *so, int proto, struct thread *td)
 1426 {
 1427         struct inpcb *inp;
 1428         int error;
 1429 
 1430         inp = sotoinpcb(so);
 1431         KASSERT(inp == NULL, ("udp_attach: inp != NULL"));
 1432         error = soreserve(so, udp_sendspace, udp_recvspace);
 1433         if (error)
 1434                 return (error);
 1435         INP_INFO_WLOCK(&V_udbinfo);
 1436         error = in_pcballoc(so, &V_udbinfo);
 1437         if (error) {
 1438                 INP_INFO_WUNLOCK(&V_udbinfo);
 1439                 return (error);
 1440         }
 1441 
 1442         inp = sotoinpcb(so);
 1443         inp->inp_vflag |= INP_IPV4;
 1444         inp->inp_ip_ttl = V_ip_defttl;
 1445 
 1446         error = udp_newudpcb(inp);
 1447         if (error) {
 1448                 in_pcbdetach(inp);
 1449                 in_pcbfree(inp);
 1450                 INP_INFO_WUNLOCK(&V_udbinfo);
 1451                 return (error);
 1452         }
 1453 
 1454         INP_WUNLOCK(inp);
 1455         INP_INFO_WUNLOCK(&V_udbinfo);
 1456         return (0);
 1457 }
 1458 
 1459 int
 1460 udp_set_kernel_tunneling(struct socket *so, udp_tun_func_t f)
 1461 {
 1462         struct inpcb *inp;
 1463         struct udpcb *up;
 1464 
 1465         KASSERT(so->so_type == SOCK_DGRAM,
 1466             ("udp_set_kernel_tunneling: !dgram"));
 1467         inp = sotoinpcb(so);
 1468         KASSERT(inp != NULL, ("udp_set_kernel_tunneling: inp == NULL"));
 1469         INP_WLOCK(inp);
 1470         up = intoudpcb(inp);
 1471         if (up->u_tun_func != NULL) {
 1472                 INP_WUNLOCK(inp);
 1473                 return (EBUSY);
 1474         }
 1475         up->u_tun_func = f;
 1476         INP_WUNLOCK(inp);
 1477         return (0);
 1478 }
 1479 
 1480 static int
 1481 udp_bind(struct socket *so, struct sockaddr *nam, struct thread *td)
 1482 {
 1483         struct inpcb *inp;
 1484         int error;
 1485 
 1486         inp = sotoinpcb(so);
 1487         KASSERT(inp != NULL, ("udp_bind: inp == NULL"));
 1488         INP_INFO_WLOCK(&V_udbinfo);
 1489         INP_WLOCK(inp);
 1490         error = in_pcbbind(inp, nam, td->td_ucred);
 1491         INP_WUNLOCK(inp);
 1492         INP_INFO_WUNLOCK(&V_udbinfo);
 1493         return (error);
 1494 }
 1495 
 1496 static void
 1497 udp_close(struct socket *so)
 1498 {
 1499         struct inpcb *inp;
 1500 
 1501         inp = sotoinpcb(so);
 1502         KASSERT(inp != NULL, ("udp_close: inp == NULL"));
 1503         INP_INFO_WLOCK(&V_udbinfo);
 1504         INP_WLOCK(inp);
 1505         if (inp->inp_faddr.s_addr != INADDR_ANY) {
 1506                 in_pcbdisconnect(inp);
 1507                 inp->inp_laddr.s_addr = INADDR_ANY;
 1508                 soisdisconnected(so);
 1509         }
 1510         INP_WUNLOCK(inp);
 1511         INP_INFO_WUNLOCK(&V_udbinfo);
 1512 }
 1513 
 1514 static int
 1515 udp_connect(struct socket *so, struct sockaddr *nam, struct thread *td)
 1516 {
 1517         struct inpcb *inp;
 1518         int error;
 1519         struct sockaddr_in *sin;
 1520 
 1521         inp = sotoinpcb(so);
 1522         KASSERT(inp != NULL, ("udp_connect: inp == NULL"));
 1523         INP_INFO_WLOCK(&V_udbinfo);
 1524         INP_WLOCK(inp);
 1525         if (inp->inp_faddr.s_addr != INADDR_ANY) {
 1526                 INP_WUNLOCK(inp);
 1527                 INP_INFO_WUNLOCK(&V_udbinfo);
 1528                 return (EISCONN);
 1529         }
 1530         sin = (struct sockaddr_in *)nam;
 1531         error = prison_remote_ip4(td->td_ucred, &sin->sin_addr);
 1532         if (error != 0) {
 1533                 INP_WUNLOCK(inp);
 1534                 INP_INFO_WUNLOCK(&V_udbinfo);
 1535                 return (error);
 1536         }
 1537         error = in_pcbconnect(inp, nam, td->td_ucred);
 1538         if (error == 0)
 1539                 soisconnected(so);
 1540         INP_WUNLOCK(inp);
 1541         INP_INFO_WUNLOCK(&V_udbinfo);
 1542         return (error);
 1543 }
 1544 
 1545 static void
 1546 udp_detach(struct socket *so)
 1547 {
 1548         struct inpcb *inp;
 1549         struct udpcb *up;
 1550 
 1551         inp = sotoinpcb(so);
 1552         KASSERT(inp != NULL, ("udp_detach: inp == NULL"));
 1553         KASSERT(inp->inp_faddr.s_addr == INADDR_ANY,
 1554             ("udp_detach: not disconnected"));
 1555         INP_INFO_WLOCK(&V_udbinfo);
 1556         INP_WLOCK(inp);
 1557         up = intoudpcb(inp);
 1558         KASSERT(up != NULL, ("%s: up == NULL", __func__));
 1559         inp->inp_ppcb = NULL;
 1560         in_pcbdetach(inp);
 1561         in_pcbfree(inp);
 1562         INP_INFO_WUNLOCK(&V_udbinfo);
 1563         udp_discardcb(up);
 1564 }
 1565 
 1566 static int
 1567 udp_disconnect(struct socket *so)
 1568 {
 1569         struct inpcb *inp;
 1570 
 1571         inp = sotoinpcb(so);
 1572         KASSERT(inp != NULL, ("udp_disconnect: inp == NULL"));
 1573         INP_INFO_WLOCK(&V_udbinfo);
 1574         INP_WLOCK(inp);
 1575         if (inp->inp_faddr.s_addr == INADDR_ANY) {
 1576                 INP_WUNLOCK(inp);
 1577                 INP_INFO_WUNLOCK(&V_udbinfo);
 1578                 return (ENOTCONN);
 1579         }
 1580 
 1581         in_pcbdisconnect(inp);
 1582         inp->inp_laddr.s_addr = INADDR_ANY;
 1583         SOCK_LOCK(so);
 1584         so->so_state &= ~SS_ISCONNECTED;                /* XXX */
 1585         SOCK_UNLOCK(so);
 1586         INP_WUNLOCK(inp);
 1587         INP_INFO_WUNLOCK(&V_udbinfo);
 1588         return (0);
 1589 }
 1590 
 1591 static int
 1592 udp_send(struct socket *so, int flags, struct mbuf *m, struct sockaddr *addr,
 1593     struct mbuf *control, struct thread *td)
 1594 {
 1595         struct inpcb *inp;
 1596 
 1597         inp = sotoinpcb(so);
 1598         KASSERT(inp != NULL, ("udp_send: inp == NULL"));
 1599         return (udp_output(inp, m, addr, control, td));
 1600 }
 1601 
 1602 int
 1603 udp_shutdown(struct socket *so)
 1604 {
 1605         struct inpcb *inp;
 1606 
 1607         inp = sotoinpcb(so);
 1608         KASSERT(inp != NULL, ("udp_shutdown: inp == NULL"));
 1609         INP_WLOCK(inp);
 1610         socantsendmore(so);
 1611         INP_WUNLOCK(inp);
 1612         return (0);
 1613 }
 1614 
 1615 struct pr_usrreqs udp_usrreqs = {
 1616         .pru_abort =            udp_abort,
 1617         .pru_attach =           udp_attach,
 1618         .pru_bind =             udp_bind,
 1619         .pru_connect =          udp_connect,
 1620         .pru_control =          in_control,
 1621         .pru_detach =           udp_detach,
 1622         .pru_disconnect =       udp_disconnect,
 1623         .pru_peeraddr =         in_getpeeraddr,
 1624         .pru_send =             udp_send,
 1625         .pru_soreceive =        soreceive_dgram,
 1626         .pru_sosend =           sosend_dgram,
 1627         .pru_shutdown =         udp_shutdown,
 1628         .pru_sockaddr =         in_getsockaddr,
 1629         .pru_sosetlabel =       in_pcbsosetlabel,
 1630         .pru_close =            udp_close,
 1631 };

Cache object: af8e5204dbfe8605d794387a107152c1


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