sys/netinet/in_pcb.c

   1 /*
   2  * Copyright (c) 2004 Jeffrey M. Hsu.  All rights reserved.
   3  * Copyright (c) 2004 The DragonFly Project.  All rights reserved.
   4  *
   5  * This code is derived from software contributed to The DragonFly Project
   6  * by Jeffrey M. Hsu.
   7  *
   8  * Redistribution and use in source and binary forms, with or without
   9  * modification, are permitted provided that the following conditions
  10  * are met:
  11  * 1. Redistributions of source code must retain the above copyright
  12  *    notice, this list of conditions and the following disclaimer.
  13  * 2. Redistributions in binary form must reproduce the above copyright
  14  *    notice, this list of conditions and the following disclaimer in the
  15  *    documentation and/or other materials provided with the distribution.
  16  * 3. Neither the name of The DragonFly Project nor the names of its
  17  *    contributors may be used to endorse or promote products derived
  18  *    from this software without specific, prior written permission.
  19  *
  20  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  21  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  22  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
  23  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE
  24  * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
  25  * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
  26  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  27  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
  28  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
  29  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
  30  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  31  * SUCH DAMAGE.
  32  */
  33
  34 /*
  35  * Copyright (c) 2004 Jeffrey M. Hsu.  All rights reserved.
  36  *
  37  * License terms: all terms for the DragonFly license above plus the following:
  38  *
  39  * 4. All advertising materials mentioning features or use of this software
  40  *    must display the following acknowledgement:
  41  *
  42  *      This product includes software developed by Jeffrey M. Hsu
  43  *      for the DragonFly Project.
  44  *
  45  *    This requirement may be waived with permission from Jeffrey Hsu.
  46  *    This requirement will sunset and may be removed on July 8 2005,
  47  *    after which the standard DragonFly license (as shown above) will
  48  *    apply.
  49  */
  50
  51 /*
  52  * Copyright (c) 1982, 1986, 1991, 1993, 1995
  53  *      The Regents of the University of California.  All rights reserved.
  54  *
  55  * Redistribution and use in source and binary forms, with or without
  56  * modification, are permitted provided that the following conditions
  57  * are met:
  58  * 1. Redistributions of source code must retain the above copyright
  59  *    notice, this list of conditions and the following disclaimer.
  60  * 2. Redistributions in binary form must reproduce the above copyright
  61  *    notice, this list of conditions and the following disclaimer in the
  62  *    documentation and/or other materials provided with the distribution.
  63  * 3. All advertising materials mentioning features or use of this software
  64  *    must display the following acknowledgement:
  65  *      This product includes software developed by the University of
  66  *      California, Berkeley and its contributors.
  67  * 4. Neither the name of the University nor the names of its contributors
  68  *    may be used to endorse or promote products derived from this software
  69  *    without specific prior written permission.
  70  *
  71  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  72  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  73  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  74  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  75  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  76  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  77  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  78  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  79  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  80  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  81  * SUCH DAMAGE.
  82  *
  83  *      @(#)in_pcb.c    8.4 (Berkeley) 5/24/95
  84  * $FreeBSD: src/sys/netinet/in_pcb.c,v 1.59.2.27 2004/01/02 04:06:42 ambrisko Exp $
  85  * $DragonFly: src/sys/netinet/in_pcb.c,v 1.33 2005/02/08 22:56:19 hsu Exp $
  86  */
  87
  88 #include "opt_ipsec.h"
  89 #include "opt_inet6.h"
  90
  91 #include <sys/param.h>
  92 #include <sys/systm.h>
  93 #include <sys/malloc.h>
  94 #include <sys/mbuf.h>
  95 #include <sys/domain.h>
  96 #include <sys/protosw.h>
  97 #include <sys/socket.h>
  98 #include <sys/socketvar.h>
  99 #include <sys/proc.h>
 100 #include <sys/jail.h>
 101 #include <sys/kernel.h>
 102 #include <sys/sysctl.h>
 103
 104 #include <machine/limits.h>
 105
 106 #include <vm/vm_zone.h>
 107
 108 #include <net/if.h>
 109 #include <net/if_types.h>
 110 #include <net/route.h>
 111
 112 #include <netinet/in.h>
 113 #include <netinet/in_pcb.h>
 114 #include <netinet/in_var.h>
 115 #include <netinet/ip_var.h>
 116 #ifdef INET6
 117 #include <netinet/ip6.h>
 118 #include <netinet6/ip6_var.h>
 119 #endif /* INET6 */
 120
 121 #ifdef IPSEC
 122 #include <netinet6/ipsec.h>
 123 #include <netproto/key/key.h>
 124 #endif
 125
 126 #ifdef FAST_IPSEC
 127 #if defined(IPSEC) || defined(IPSEC_ESP)
 128 #error "Bad idea: don't compile with both IPSEC and FAST_IPSEC!"
 129 #endif
 130
 131 #include <netproto/ipsec/ipsec.h>
 132 #include <netproto/ipsec/key.h>
 133 #define IPSEC
 134 #endif /* FAST_IPSEC */
 135
 136 struct in_addr zeroin_addr;
 137
 138 /*
 139  * These configure the range of local port addresses assigned to
 140  * "unspecified" outgoing connections/packets/whatever.
 141  */
 142 int ipport_lowfirstauto = IPPORT_RESERVED - 1;  /* 1023 */
 143 int ipport_lowlastauto = IPPORT_RESERVEDSTART;  /* 600 */
 144
 145 int ipport_firstauto = IPPORT_RESERVED;         /* 1024 */
 146 int ipport_lastauto = IPPORT_USERRESERVED;      /* 5000 */
 147
 148 int ipport_hifirstauto = IPPORT_HIFIRSTAUTO;    /* 49152 */
 149 int ipport_hilastauto = IPPORT_HILASTAUTO;      /* 65535 */
 150
 151 static __inline void
 152 RANGECHK(int var, int min, int max)
 153 {
 154         if (var < min)
 155                 var = min;
 156         else if (var > max)
 157                 var = max;
 158 }
 159
 160 static int
 161 sysctl_net_ipport_check(SYSCTL_HANDLER_ARGS)
 162 {
 163         int error;
 164
 165         error = sysctl_handle_int(oidp, oidp->oid_arg1, oidp->oid_arg2, req);
 166         if (!error) {
 167                 RANGECHK(ipport_lowfirstauto, 1, IPPORT_RESERVED - 1);
 168                 RANGECHK(ipport_lowlastauto, 1, IPPORT_RESERVED - 1);
 169
 170                 RANGECHK(ipport_firstauto, IPPORT_RESERVED, USHRT_MAX);
 171                 RANGECHK(ipport_lastauto, IPPORT_RESERVED, USHRT_MAX);
 172
 173                 RANGECHK(ipport_hifirstauto, IPPORT_RESERVED, USHRT_MAX);
 174                 RANGECHK(ipport_hilastauto, IPPORT_RESERVED, USHRT_MAX);
 175         }
 176         return (error);
 177 }
 178
 179 SYSCTL_NODE(_net_inet_ip, IPPROTO_IP, portrange, CTLFLAG_RW, 0, "IP Ports");
 180
 181 SYSCTL_PROC(_net_inet_ip_portrange, OID_AUTO, lowfirst, CTLTYPE_INT|CTLFLAG_RW,
 182            &ipport_lowfirstauto, 0, &sysctl_net_ipport_check, "I", "");
 183 SYSCTL_PROC(_net_inet_ip_portrange, OID_AUTO, lowlast, CTLTYPE_INT|CTLFLAG_RW,
 184            &ipport_lowlastauto, 0, &sysctl_net_ipport_check, "I", "");
 185 SYSCTL_PROC(_net_inet_ip_portrange, OID_AUTO, first, CTLTYPE_INT|CTLFLAG_RW,
 186            &ipport_firstauto, 0, &sysctl_net_ipport_check, "I", "");
 187 SYSCTL_PROC(_net_inet_ip_portrange, OID_AUTO, last, CTLTYPE_INT|CTLFLAG_RW,
 188            &ipport_lastauto, 0, &sysctl_net_ipport_check, "I", "");
 189 SYSCTL_PROC(_net_inet_ip_portrange, OID_AUTO, hifirst, CTLTYPE_INT|CTLFLAG_RW,
 190            &ipport_hifirstauto, 0, &sysctl_net_ipport_check, "I", "");
 191 SYSCTL_PROC(_net_inet_ip_portrange, OID_AUTO, hilast, CTLTYPE_INT|CTLFLAG_RW,
 192            &ipport_hilastauto, 0, &sysctl_net_ipport_check, "I", "");
 193
 194 /*
 195  * in_pcb.c: manage the Protocol Control Blocks.
 196  *
 197  * NOTE: It is assumed that most of these functions will be called at
 198  * splnet(). XXX - There are, unfortunately, a few exceptions to this
 199  * rule that should be fixed.
 200  *
 201  * NOTE: The caller should initialize the cpu field to the cpu running the
 202  * protocol stack associated with this inpcbinfo.
 203  */
 204
 205 void
 206 in_pcbinfo_init(struct inpcbinfo *pcbinfo)
 207 {
 208         LIST_INIT(&pcbinfo->pcblisthead);
 209         pcbinfo->cpu = -1;
 210 }
 211
 212 /*
 213  * Allocate a PCB and associate it with the socket.
 214  */
 215 int
 216 in_pcballoc(struct socket *so, struct inpcbinfo *pcbinfo)
 217 {
 218         struct inpcb *inp;
 219 #ifdef IPSEC
 220         int error;
 221 #endif
 222
 223         inp = zalloc(pcbinfo->ipi_zone);
 224         if (inp == NULL)
 225                 return (ENOBUFS);
 226         bzero(inp, sizeof *inp);
 227         inp->inp_gencnt = ++pcbinfo->ipi_gencnt;
 228         inp->inp_pcbinfo = inp->inp_cpcbinfo = pcbinfo;
 229         inp->inp_socket = so;
 230 #ifdef IPSEC
 231         error = ipsec_init_policy(so, &inp->inp_sp);
 232         if (error != 0) {
 233                 zfree(pcbinfo->ipi_zone, inp);
 234                 return (error);
 235         }
 236 #endif
 237 #ifdef INET6
 238         if (INP_SOCKAF(so) == AF_INET6 && ip6_v6only)
 239                 inp->inp_flags |= IN6P_IPV6_V6ONLY;
 240         if (ip6_auto_flowlabel)
 241                 inp->inp_flags |= IN6P_AUTOFLOWLABEL;
 242 #endif
 243         so->so_pcb = inp;
 244         LIST_INSERT_HEAD(&pcbinfo->pcblisthead, inp, inp_list);
 245         pcbinfo->ipi_count++;
 246         return (0);
 247 }
 248
 249 int
 250 in_pcbbind(struct inpcb *inp, struct sockaddr *nam, struct thread *td)
 251 {
 252         struct socket *so = inp->inp_socket;
 253         struct proc *p = td->td_proc;
 254         unsigned short *lastport;
 255         struct sockaddr_in *sin;
 256         struct inpcbinfo *pcbinfo = inp->inp_pcbinfo;
 257         u_short lport = 0;
 258         int wild = 0, reuseport = (so->so_options & SO_REUSEPORT);
 259         int error, prison = 0;
 260
 261         KKASSERT(p);
 262
 263         if (TAILQ_EMPTY(&in_ifaddrhead)) /* XXX broken! */
 264                 return (EADDRNOTAVAIL);
 265         if (inp->inp_lport != 0 || inp->inp_laddr.s_addr != INADDR_ANY)
 266                 return (EINVAL);        /* already bound */
 267         if (!(so->so_options & (SO_REUSEADDR|SO_REUSEPORT)))
 268                 wild = 1;    /* neither SO_REUSEADDR nor SO_REUSEPORT is set */
 269         if (nam != NULL) {
 270                 sin = (struct sockaddr_in *)nam;
 271                 if (nam->sa_len != sizeof *sin)
 272                         return (EINVAL);
 273 #ifdef notdef
 274                 /*
 275                  * We should check the family, but old programs
 276                  * incorrectly fail to initialize it.
 277                  */
 278                 if (sin->sin_family != AF_INET)
 279                         return (EAFNOSUPPORT);
 280 #endif
 281                 if (sin->sin_addr.s_addr != INADDR_ANY &&
 282                     prison_ip(td, 0, &sin->sin_addr.s_addr))
 283                                 return (EINVAL);
 284                 lport = sin->sin_port;
 285                 if (IN_MULTICAST(ntohl(sin->sin_addr.s_addr))) {
 286                         /*
 287                          * Treat SO_REUSEADDR as SO_REUSEPORT for multicast;
 288                          * allow complete duplication of binding if
 289                          * SO_REUSEPORT is set, or if SO_REUSEADDR is set
 290                          * and a multicast address is bound on both
 291                          * new and duplicated sockets.
 292                          */
 293                         if (so->so_options & SO_REUSEADDR)
 294                                 reuseport = SO_REUSEADDR | SO_REUSEPORT;
 295                 } else if (sin->sin_addr.s_addr != INADDR_ANY) {
 296                         sin->sin_port = 0;              /* yech... */
 297                         bzero(&sin->sin_zero, sizeof sin->sin_zero);
 298                         if (ifa_ifwithaddr((struct sockaddr *)sin) == NULL)
 299                                 return (EADDRNOTAVAIL);
 300                 }
 301                 if (lport != 0) {
 302                         struct inpcb *t;
 303
 304                         /* GROSS */
 305                         if (ntohs(lport) < IPPORT_RESERVED &&
 306                             p && suser_cred(p->p_ucred, PRISON_ROOT))
 307                                 return (EACCES);
 308                         if (p && p->p_ucred->cr_prison)
 309                                 prison = 1;
 310                         if (so->so_cred->cr_uid != 0 &&
 311                             !IN_MULTICAST(ntohl(sin->sin_addr.s_addr))) {
 312                                 t = in_pcblookup_local(inp->inp_pcbinfo,
 313                                     sin->sin_addr, lport,
 314                                     prison ? 0 : INPLOOKUP_WILDCARD);
 315                                 if (t &&
 316                                     (!in_nullhost(sin->sin_addr) ||
 317                                      !in_nullhost(t->inp_laddr) ||
 318                                      (t->inp_socket->so_options &
 319                                          SO_REUSEPORT) == 0) &&
 320                                     (so->so_cred->cr_uid !=
 321                                      t->inp_socket->so_cred->cr_uid)) {
 322 #ifdef INET6
 323                                         if (!in_nullhost(sin->sin_addr) ||
 324                                             !in_nullhost(t->inp_laddr) ||
 325                                             INP_SOCKAF(so) ==
 326                                             INP_SOCKAF(t->inp_socket))
 327 #endif
 328                                         return (EADDRINUSE);
 329                                 }
 330                         }
 331                         if (prison && prison_ip(td, 0, &sin->sin_addr.s_addr))
 332                                 return (EADDRNOTAVAIL);
 333                         t = in_pcblookup_local(pcbinfo, sin->sin_addr,
 334                             lport, prison ? 0 : wild);
 335                         if (t && !(reuseport & t->inp_socket->so_options)) {
 336 #ifdef INET6
 337                                 if (!in_nullhost(sin->sin_addr) ||
 338                                     !in_nullhost(t->inp_laddr) ||
 339                                     INP_SOCKAF(so) == INP_SOCKAF(t->inp_socket))
 340 #endif
 341                                 return (EADDRINUSE);
 342                         }
 343                 }
 344                 inp->inp_laddr = sin->sin_addr;
 345         }
 346         if (lport == 0) {
 347                 ushort first, last;
 348                 int count;
 349
 350                 if (inp->inp_laddr.s_addr != INADDR_ANY &&
 351                     prison_ip(td, 0, &inp->inp_laddr.s_addr )) {
 352                         inp->inp_laddr.s_addr = INADDR_ANY;
 353                         return (EINVAL);
 354                 }
 355                 inp->inp_flags |= INP_ANONPORT;
 356
 357                 if (inp->inp_flags & INP_HIGHPORT) {
 358                         first = ipport_hifirstauto;     /* sysctl */
 359                         last  = ipport_hilastauto;
 360                         lastport = &pcbinfo->lasthi;
 361                 } else if (inp->inp_flags & INP_LOWPORT) {
 362                         if (p &&
 363                             (error = suser_cred(p->p_ucred, PRISON_ROOT))) {
 364                                 inp->inp_laddr.s_addr = INADDR_ANY;
 365                                 return (error);
 366                         }
 367                         first = ipport_lowfirstauto;    /* 1023 */
 368                         last  = ipport_lowlastauto;     /* 600 */
 369                         lastport = &pcbinfo->lastlow;
 370                 } else {
 371                         first = ipport_firstauto;       /* sysctl */
 372                         last  = ipport_lastauto;
 373                         lastport = &pcbinfo->lastport;
 374                 }
 375                 /*
 376                  * Simple check to ensure all ports are not used up causing
 377                  * a deadlock here.
 378                  *
 379                  * We split the two cases (up and down) so that the direction
 380                  * is not being tested on each round of the loop.
 381                  */
 382                 if (first > last) {
 383                         /*
 384                          * counting down
 385                          */
 386                         count = first - last;
 387
 388                         do {
 389                                 if (count-- < 0) {      /* completely used? */
 390                                         inp->inp_laddr.s_addr = INADDR_ANY;
 391                                         return (EADDRNOTAVAIL);
 392                                 }
 393                                 --*lastport;
 394                                 if (*lastport > first || *lastport < last)
 395                                         *lastport = first;
 396                                 lport = htons(*lastport);
 397                         } while (in_pcblookup_local(pcbinfo,
 398                                  inp->inp_laddr, lport, wild));
 399                 } else {
 400                         /*
 401                          * counting up
 402                          */
 403                         count = last - first;
 404
 405                         do {
 406                                 if (count-- < 0) {      /* completely used? */
 407                                         inp->inp_laddr.s_addr = INADDR_ANY;
 408                                         return (EADDRNOTAVAIL);
 409                                 }
 410                                 ++*lastport;
 411                                 if (*lastport < first || *lastport > last)
 412                                         *lastport = first;
 413                                 lport = htons(*lastport);
 414                         } while (in_pcblookup_local(pcbinfo,
 415                                  inp->inp_laddr, lport, wild));
 416                 }
 417         }
 418         inp->inp_lport = lport;
 419         if (prison_ip(td, 0, &inp->inp_laddr.s_addr)) {
 420                 inp->inp_laddr.s_addr = INADDR_ANY;
 421                 inp->inp_lport = 0;
 422                 return (EINVAL);
 423         }
 424         if (in_pcbinsporthash(inp) != 0) {
 425                 inp->inp_laddr.s_addr = INADDR_ANY;
 426                 inp->inp_lport = 0;
 427                 return (EAGAIN);
 428         }
 429         return (0);
 430 }
 431
 432 /*
 433  *   Transform old in_pcbconnect() into an inner subroutine for new
 434  *   in_pcbconnect(): Do some validity-checking on the remote
 435  *   address (in mbuf 'nam') and then determine local host address
 436  *   (i.e., which interface) to use to access that remote host.
 437  *
 438  *   This preserves definition of in_pcbconnect(), while supporting a
 439  *   slightly different version for T/TCP.  (This is more than
 440  *   a bit of a kludge, but cleaning up the internal interfaces would
 441  *   have forced minor changes in every protocol).
 442  */
 443 int
 444 in_pcbladdr(inp, nam, plocal_sin)
 445         struct inpcb *inp;
 446         struct sockaddr *nam;
 447         struct sockaddr_in **plocal_sin;
 448 {
 449         struct in_ifaddr *ia;
 450         struct sockaddr_in *sin = (struct sockaddr_in *)nam;
 451
 452         if (nam->sa_len != sizeof *sin)
 453                 return (EINVAL);
 454         if (sin->sin_family != AF_INET)
 455                 return (EAFNOSUPPORT);
 456         if (sin->sin_port == 0)
 457                 return (EADDRNOTAVAIL);
 458         if (!TAILQ_EMPTY(&in_ifaddrhead)) {
 459                 ia = TAILQ_FIRST(&in_ifaddrhead);
 460                 /*
 461                  * If the destination address is INADDR_ANY,
 462                  * use the primary local address.
 463                  * If the supplied address is INADDR_BROADCAST,
 464                  * and the primary interface supports broadcast,
 465                  * choose the broadcast address for that interface.
 466                  */
 467                 if (sin->sin_addr.s_addr == INADDR_ANY)
 468                         sin->sin_addr = IA_SIN(ia)->sin_addr;
 469                 else if (sin->sin_addr.s_addr == (u_long)INADDR_BROADCAST &&
 470                     (ia->ia_ifp->if_flags & IFF_BROADCAST))
 471                         sin->sin_addr = satosin(&ia->ia_broadaddr)->sin_addr;
 472         }
 473         if (inp->inp_laddr.s_addr == INADDR_ANY) {
 474                 struct route *ro;
 475
 476                 ia = (struct in_ifaddr *)NULL;
 477                 /*
 478                  * If route is known or can be allocated now,
 479                  * our src addr is taken from the i/f, else punt.
 480                  * Note that we should check the address family of the cached
 481                  * destination, in case of sharing the cache with IPv6.
 482                  */
 483                 ro = &inp->inp_route;
 484                 if (ro->ro_rt &&
 485                     (!(ro->ro_rt->rt_flags & RTF_UP) ||
 486                      ro->ro_dst.sa_family != AF_INET ||
 487                      satosin(&ro->ro_dst)->sin_addr.s_addr !=
 488                                       sin->sin_addr.s_addr ||
 489                      inp->inp_socket->so_options & SO_DONTROUTE)) {
 490                         RTFREE(ro->ro_rt);
 491                         ro->ro_rt = (struct rtentry *)NULL;
 492                 }
 493                 if (!(inp->inp_socket->so_options & SO_DONTROUTE) && /*XXX*/
 494                     (ro->ro_rt == (struct rtentry *)NULL ||
 495                     ro->ro_rt->rt_ifp == (struct ifnet *)NULL)) {
 496                         /* No route yet, so try to acquire one */
 497                         bzero(&ro->ro_dst, sizeof(struct sockaddr_in));
 498                         ro->ro_dst.sa_family = AF_INET;
 499                         ro->ro_dst.sa_len = sizeof(struct sockaddr_in);
 500                         ((struct sockaddr_in *) &ro->ro_dst)->sin_addr =
 501                                 sin->sin_addr;
 502                         rtalloc(ro);
 503                 }
 504                 /*
 505                  * If we found a route, use the address
 506                  * corresponding to the outgoing interface
 507                  * unless it is the loopback (in case a route
 508                  * to our address on another net goes to loopback).
 509                  */
 510                 if (ro->ro_rt && !(ro->ro_rt->rt_ifp->if_flags & IFF_LOOPBACK))
 511                         ia = ifatoia(ro->ro_rt->rt_ifa);
 512                 if (ia == NULL) {
 513                         u_short fport = sin->sin_port;
 514
 515                         sin->sin_port = 0;
 516                         ia = ifatoia(ifa_ifwithdstaddr(sintosa(sin)));
 517                         if (ia == NULL)
 518                                 ia = ifatoia(ifa_ifwithnet(sintosa(sin)));
 519                         sin->sin_port = fport;
 520                         if (ia == NULL)
 521                                 ia = TAILQ_FIRST(&in_ifaddrhead);
 522                         if (ia == NULL)
 523                                 return (EADDRNOTAVAIL);
 524                 }
 525                 /*
 526                  * If the destination address is multicast and an outgoing
 527                  * interface has been set as a multicast option, use the
 528                  * address of that interface as our source address.
 529                  */
 530                 if (IN_MULTICAST(ntohl(sin->sin_addr.s_addr)) &&
 531                     inp->inp_moptions != NULL) {
 532                         struct ip_moptions *imo;
 533                         struct ifnet *ifp;
 534
 535                         imo = inp->inp_moptions;
 536                         if (imo->imo_multicast_ifp != NULL) {
 537                                 ifp = imo->imo_multicast_ifp;
 538                                 TAILQ_FOREACH(ia, &in_ifaddrhead, ia_link)
 539                                         if (ia->ia_ifp == ifp)
 540                                                 break;
 541                                 if (ia == NULL)
 542                                         return (EADDRNOTAVAIL);
 543                         }
 544                 }
 545                 /*
 546                  * Don't do pcblookup call here; return interface in plocal_sin
 547                  * and exit to caller, that will do the lookup.
 548                  */
 549                 *plocal_sin = &ia->ia_addr;
 550
 551         }
 552         return (0);
 553 }
 554
 555 /*
 556  * Outer subroutine:
 557  * Connect from a socket to a specified address.
 558  * Both address and port must be specified in argument sin.
 559  * If don't have a local address for this socket yet,
 560  * then pick one.
 561  */
 562 int
 563 in_pcbconnect(struct inpcb *inp, struct sockaddr *nam, struct thread *td)
 564 {
 565         struct sockaddr_in *if_sin;
 566         struct sockaddr_in *sin = (struct sockaddr_in *)nam;
 567         struct sockaddr_in sa;
 568         struct ucred *cr = td->td_proc ? td->td_proc->p_ucred : NULL;
 569         int error;
 570
 571         if (cr && cr->cr_prison != NULL && in_nullhost(inp->inp_laddr)) {
 572                 bzero(&sa, sizeof sa);
 573                 sa.sin_addr.s_addr = htonl(cr->cr_prison->pr_ip);
 574                 sa.sin_len = sizeof sa;
 575                 sa.sin_family = AF_INET;
 576                 error = in_pcbbind(inp, (struct sockaddr *)&sa, td);
 577                 if (error)
 578                         return (error);
 579         }
 580
 581         /* Call inner routine to assign local interface address. */
 582         if ((error = in_pcbladdr(inp, nam, &if_sin)) != 0)
 583                 return (error);
 584
 585         if (in_pcblookup_hash(inp->inp_cpcbinfo, sin->sin_addr, sin->sin_port,
 586             inp->inp_laddr.s_addr ? inp->inp_laddr : if_sin->sin_addr,
 587             inp->inp_lport, FALSE, NULL) != NULL) {
 588                 return (EADDRINUSE);
 589         }
 590         if (inp->inp_laddr.s_addr == INADDR_ANY) {
 591                 if (inp->inp_lport == 0) {
 592                         error = in_pcbbind(inp, (struct sockaddr *)NULL, td);
 593                         if (error)
 594                                 return (error);
 595                 }
 596                 inp->inp_laddr = if_sin->sin_addr;
 597         }
 598         inp->inp_faddr = sin->sin_addr;
 599         inp->inp_fport = sin->sin_port;
 600         in_pcbinsconnhash(inp);
 601         return (0);
 602 }
 603
 604 void
 605 in_pcbdisconnect(inp)
 606         struct inpcb *inp;
 607 {
 608
 609         inp->inp_faddr.s_addr = INADDR_ANY;
 610         inp->inp_fport = 0;
 611         in_pcbremconnhash(inp);
 612         if (inp->inp_socket->so_state & SS_NOFDREF)
 613                 in_pcbdetach(inp);
 614 }
 615
 616 void
 617 in_pcbdetach(inp)
 618         struct inpcb *inp;
 619 {
 620         struct socket *so = inp->inp_socket;
 621         struct inpcbinfo *ipi = inp->inp_pcbinfo;
 622
 623 #ifdef IPSEC
 624         ipsec4_delete_pcbpolicy(inp);
 625 #endif /*IPSEC*/
 626         inp->inp_gencnt = ++ipi->ipi_gencnt;
 627         in_pcbremlists(inp);
 628         so->so_pcb = 0;
 629         sofree(so);
 630         if (inp->inp_options)
 631                 m_free(inp->inp_options);
 632         if (inp->inp_route.ro_rt)
 633                 rtfree(inp->inp_route.ro_rt);
 634         ip_freemoptions(inp->inp_moptions);
 635         inp->inp_vflag = 0;
 636         zfree(ipi->ipi_zone, inp);
 637 }
 638
 639 /*
 640  * The calling convention of in_setsockaddr() and in_setpeeraddr() was
 641  * modified to match the pru_sockaddr() and pru_peeraddr() entry points
 642  * in struct pr_usrreqs, so that protocols can just reference then directly
 643  * without the need for a wrapper function.  The socket must have a valid
 644  * (i.e., non-nil) PCB, but it should be impossible to get an invalid one
 645  * except through a kernel programming error, so it is acceptable to panic
 646  * (or in this case trap) if the PCB is invalid.  (Actually, we don't trap
 647  * because there actually /is/ a programming error somewhere... XXX)
 648  */
 649 int
 650 in_setsockaddr(so, nam)
 651         struct socket *so;
 652         struct sockaddr **nam;
 653 {
 654         int s;
 655         struct inpcb *inp;
 656         struct sockaddr_in *sin;
 657
 658         /*
 659          * Do the malloc first in case it blocks.
 660          */
 661         MALLOC(sin, struct sockaddr_in *, sizeof *sin, M_SONAME,
 662                 M_WAITOK | M_ZERO);
 663         sin->sin_family = AF_INET;
 664         sin->sin_len = sizeof *sin;
 665
 666         s = splnet();
 667         inp = so->so_pcb;
 668         if (!inp) {
 669                 splx(s);
 670                 free(sin, M_SONAME);
 671                 return (ECONNRESET);
 672         }
 673         sin->sin_port = inp->inp_lport;
 674         sin->sin_addr = inp->inp_laddr;
 675         splx(s);
 676
 677         *nam = (struct sockaddr *)sin;
 678         return (0);
 679 }
 680
 681 int
 682 in_setpeeraddr(so, nam)
 683         struct socket *so;
 684         struct sockaddr **nam;
 685 {
 686         int s;
 687         struct inpcb *inp;
 688         struct sockaddr_in *sin;
 689
 690         /*
 691          * Do the malloc first in case it blocks.
 692          */
 693         MALLOC(sin, struct sockaddr_in *, sizeof *sin, M_SONAME,
 694                 M_WAITOK | M_ZERO);
 695         sin->sin_family = AF_INET;
 696         sin->sin_len = sizeof *sin;
 697
 698         s = splnet();
 699         inp = so->so_pcb;
 700         if (!inp) {
 701                 splx(s);
 702                 free(sin, M_SONAME);
 703                 return (ECONNRESET);
 704         }
 705         sin->sin_port = inp->inp_fport;
 706         sin->sin_addr = inp->inp_faddr;
 707         splx(s);
 708
 709         *nam = (struct sockaddr *)sin;
 710         return (0);
 711 }
 712
 713 void
 714 in_pcbnotifyall(head, faddr, errno, notify)
 715         struct inpcbhead *head;
 716         struct in_addr faddr;
 717         void (*notify) (struct inpcb *, int);
 718 {
 719         struct inpcb *inp, *ninp;
 720         int s;
 721
 722         /*
 723          * note: if INP_PLACEMARKER is set we must ignore the rest of
 724          * the structure and skip it.
 725          */
 726         s = splnet();
 727         LIST_FOREACH_MUTABLE(inp, head, inp_list, ninp) {
 728                 if (inp->inp_flags & INP_PLACEMARKER)
 729                         continue;
 730 #ifdef INET6
 731                 if (!(inp->inp_vflag & INP_IPV4))
 732                         continue;
 733 #endif
 734                 if (inp->inp_faddr.s_addr != faddr.s_addr ||
 735                     inp->inp_socket == NULL)
 736                         continue;
 737                 (*notify)(inp, errno);          /* can remove inp from list! */
 738         }
 739         splx(s);
 740 }
 741
 742 void
 743 in_pcbpurgeif0(head, ifp)
 744         struct inpcb *head;
 745         struct ifnet *ifp;
 746 {
 747         struct inpcb *inp;
 748         struct ip_moptions *imo;
 749         int i, gap;
 750
 751         for (inp = head; inp != NULL; inp = LIST_NEXT(inp, inp_list)) {
 752                 if (inp->inp_flags & INP_PLACEMARKER)
 753                         continue;
 754                 imo = inp->inp_moptions;
 755                 if ((inp->inp_vflag & INP_IPV4) && imo != NULL) {
 756                         /*
 757                          * Unselect the outgoing interface if it is being
 758                          * detached.
 759                          */
 760                         if (imo->imo_multicast_ifp == ifp)
 761                                 imo->imo_multicast_ifp = NULL;
 762
 763                         /*
 764                          * Drop multicast group membership if we joined
 765                          * through the interface being detached.
 766                          */
 767                         for (i = 0, gap = 0; i < imo->imo_num_memberships;
 768                             i++) {
 769                                 if (imo->imo_membership[i]->inm_ifp == ifp) {
 770                                         in_delmulti(imo->imo_membership[i]);
 771                                         gap++;
 772                                 } else if (gap != 0)
 773                                         imo->imo_membership[i - gap] =
 774                                             imo->imo_membership[i];
 775                         }
 776                         imo->imo_num_memberships -= gap;
 777                 }
 778         }
 779 }
 780
 781 /*
 782  * Check for alternatives when higher level complains
 783  * about service problems.  For now, invalidate cached
 784  * routing information.  If the route was created dynamically
 785  * (by a redirect), time to try a default gateway again.
 786  */
 787 void
 788 in_losing(inp)
 789         struct inpcb *inp;
 790 {
 791         struct rtentry *rt;
 792         struct rt_addrinfo info;
 793
 794         if ((rt = inp->inp_route.ro_rt)) {
 795                 bzero(&info, sizeof info);
 796                 info.rti_flags = rt->rt_flags;
 797                 info.rti_info[RTAX_DST] = rt_key(rt);
 798                 info.rti_info[RTAX_GATEWAY] = rt->rt_gateway;
 799                 info.rti_info[RTAX_NETMASK] = rt_mask(rt);
 800                 rt_missmsg(RTM_LOSING, &info, rt->rt_flags, 0);
 801                 if (rt->rt_flags & RTF_DYNAMIC)
 802                         rtrequest1(RTM_DELETE, &info, NULL);
 803                 inp->inp_route.ro_rt = NULL;
 804                 rtfree(rt);
 805                 /*
 806                  * A new route can be allocated
 807                  * the next time output is attempted.
 808                  */
 809         }
 810 }
 811
 812 /*
 813  * After a routing change, flush old routing
 814  * and allocate a (hopefully) better one.
 815  */
 816 void
 817 in_rtchange(inp, errno)
 818         struct inpcb *inp;
 819         int errno;
 820 {
 821         if (inp->inp_route.ro_rt) {
 822                 rtfree(inp->inp_route.ro_rt);
 823                 inp->inp_route.ro_rt = 0;
 824                 /*
 825                  * A new route can be allocated the next time
 826                  * output is attempted.
 827                  */
 828         }
 829 }
 830
 831 /*
 832  * Lookup a PCB based on the local address and port.
 833  */
 834 struct inpcb *
 835 in_pcblookup_local(pcbinfo, laddr, lport_arg, wild_okay)
 836         struct inpcbinfo *pcbinfo;
 837         struct in_addr laddr;
 838         u_int lport_arg;
 839         int wild_okay;
 840 {
 841         struct inpcb *inp;
 842         int matchwild = 3, wildcard;
 843         u_short lport = lport_arg;
 844
 845         struct inpcbporthead *porthash;
 846         struct inpcbport *phd;
 847         struct inpcb *match = NULL;
 848
 849         /*
 850          * Best fit PCB lookup.
 851          *
 852          * First see if this local port is in use by looking on the
 853          * port hash list.
 854          */
 855         porthash = &pcbinfo->porthashbase[INP_PCBPORTHASH(lport,
 856             pcbinfo->porthashmask)];
 857         LIST_FOREACH(phd, porthash, phd_hash) {
 858                 if (phd->phd_port == lport)
 859                         break;
 860         }
 861         if (phd != NULL) {
 862                 /*
 863                  * Port is in use by one or more PCBs. Look for best
 864                  * fit.
 865                  */
 866                 LIST_FOREACH(inp, &phd->phd_pcblist, inp_portlist) {
 867                         wildcard = 0;
 868 #ifdef INET6
 869                         if ((inp->inp_vflag & INP_IPV4) == 0)
 870                                 continue;
 871 #endif
 872                         if (inp->inp_faddr.s_addr != INADDR_ANY)
 873                                 wildcard++;
 874                         if (inp->inp_laddr.s_addr != INADDR_ANY) {
 875                                 if (laddr.s_addr == INADDR_ANY)
 876                                         wildcard++;
 877                                 else if (inp->inp_laddr.s_addr != laddr.s_addr)
 878                                         continue;
 879                         } else {
 880                                 if (laddr.s_addr != INADDR_ANY)
 881                                         wildcard++;
 882                         }
 883                         if (wildcard && !wild_okay)
 884                                 continue;
 885                         if (wildcard < matchwild) {
 886                                 match = inp;
 887                                 matchwild = wildcard;
 888                                 if (matchwild == 0) {
 889                                         break;
 890                                 }
 891                         }
 892                 }
 893         }
 894         return (match);
 895 }
 896
 897 /*
 898  * Lookup PCB in hash list.
 899  */
 900 struct inpcb *
 901 in_pcblookup_hash(pcbinfo, faddr, fport_arg, laddr, lport_arg, wildcard, ifp)
 902         struct inpcbinfo *pcbinfo;
 903         struct in_addr faddr, laddr;
 904         u_int fport_arg, lport_arg;
 905         boolean_t wildcard;
 906         struct ifnet *ifp;
 907 {
 908         struct inpcbhead *head;
 909         struct inpcb *inp;
 910         u_short fport = fport_arg, lport = lport_arg;
 911
 912         /*
 913          * First look for an exact match.
 914          */
 915         head = &pcbinfo->hashbase[INP_PCBCONNHASH(faddr.s_addr, fport,
 916             laddr.s_addr, lport, pcbinfo->hashmask)];
 917         LIST_FOREACH(inp, head, inp_hash) {
 918 #ifdef INET6
 919                 if (!(inp->inp_vflag & INP_IPV4))
 920                         continue;
 921 #endif
 922                 if (in_hosteq(inp->inp_faddr, faddr) &&
 923                     in_hosteq(inp->inp_laddr, laddr) &&
 924                     inp->inp_fport == fport && inp->inp_lport == lport) {
 925                         /* found */
 926                         return (inp);
 927                 }
 928         }
 929
 930         if (wildcard) {
 931                 struct inpcb *local_wild = NULL;
 932 #ifdef INET6
 933                 struct inpcb *local_wild_mapped = NULL;
 934 #endif
 935                 struct inpcontainer *ic;
 936                 struct inpcontainerhead *chead;
 937
 938                 chead = &pcbinfo->wildcardhashbase[
 939                     INP_PCBWILDCARDHASH(lport, pcbinfo->wildcardhashmask)];
 940                 LIST_FOREACH(ic, chead, ic_list) {
 941                         inp = ic->ic_inp;
 942 #ifdef INET6
 943                         if (!(inp->inp_vflag & INP_IPV4))
 944                                 continue;
 945 #endif
 946                         if (inp->inp_lport == lport) {
 947                                 if (ifp && ifp->if_type == IFT_FAITH &&
 948                                     !(inp->inp_flags & INP_FAITH))
 949                                         continue;
 950                                 if (inp->inp_laddr.s_addr == laddr.s_addr)
 951                                         return (inp);
 952                                 if (inp->inp_laddr.s_addr == INADDR_ANY) {
 953 #ifdef INET6
 954                                         if (INP_CHECK_SOCKAF(inp->inp_socket,
 955                                                              AF_INET6))
 956                                                 local_wild_mapped = inp;
 957                                         else
 958 #endif
 959                                                 local_wild = inp;
 960                                 }
 961                         }
 962                 }
 963 #ifdef INET6
 964                 if (local_wild == NULL)
 965                         return (local_wild_mapped);
 966 #endif
 967                 return (local_wild);
 968         }
 969
 970         /*
 971          * Not found.
 972          */
 973         return (NULL);
 974 }
 975
 976 /*
 977  * Insert PCB into connection hash table.
 978  */
 979 void
 980 in_pcbinsconnhash(struct inpcb *inp)
 981 {
 982         struct inpcbinfo *pcbinfo = inp->inp_cpcbinfo;
 983         struct inpcbhead *bucket;
 984         u_int32_t hashkey_faddr, hashkey_laddr;
 985
 986 #ifdef INET6
 987         if (inp->inp_vflag & INP_IPV6) {
 988                 hashkey_faddr = inp->in6p_faddr.s6_addr32[3] /* XXX JH */;
 989                 hashkey_laddr = inp->in6p_laddr.s6_addr32[3] /* XXX JH */;
 990         } else {
 991 #endif
 992                 hashkey_faddr = inp->inp_faddr.s_addr;
 993                 hashkey_laddr = inp->inp_laddr.s_addr;
 994 #ifdef INET6
 995         }
 996 #endif
 997
 998         KASSERT(!(inp->inp_flags & INP_CONNECTED), ("already on hash list"));
 999         inp->inp_flags |= INP_CONNECTED;
1000
1001         /*
1002          * Insert into the connection hash table.
1003          */
1004         bucket = &pcbinfo->hashbase[INP_PCBCONNHASH(hashkey_faddr,
1005             inp->inp_fport, hashkey_laddr, inp->inp_lport, pcbinfo->hashmask)];
1006         LIST_INSERT_HEAD(bucket, inp, inp_hash);
1007 }
1008
1009 /*
1010  * Remove PCB from connection hash table.
1011  */
1012 void
1013 in_pcbremconnhash(struct inpcb *inp)
1014 {
1015         KASSERT(inp->inp_flags & INP_CONNECTED, ("inp not connected"));
1016         LIST_REMOVE(inp, inp_hash);
1017         inp->inp_flags &= ~INP_CONNECTED;
1018 }
1019
1020 /*
1021  * Insert PCB into port hash table.
1022  */
1023 int
1024 in_pcbinsporthash(struct inpcb *inp)
1025 {
1026         struct inpcbinfo *pcbinfo = inp->inp_pcbinfo;
1027         struct inpcbporthead *pcbporthash;
1028         struct inpcbport *phd;
1029
1030         /*
1031          * Insert into the port hash table.
1032          */
1033         pcbporthash = &pcbinfo->porthashbase[
1034             INP_PCBPORTHASH(inp->inp_lport, pcbinfo->porthashmask)];
1035
1036         /* Go through port list and look for a head for this lport. */
1037         LIST_FOREACH(phd, pcbporthash, phd_hash)
1038                 if (phd->phd_port == inp->inp_lport)
1039                         break;
1040
1041         /* If none exists, malloc one and tack it on. */
1042         if (phd == NULL) {
1043                 MALLOC(phd, struct inpcbport *, sizeof(struct inpcbport),
1044                     M_PCB, M_INTWAIT | M_NULLOK);
1045                 if (phd == NULL)
1046                         return (ENOBUFS); /* XXX */
1047                 phd->phd_port = inp->inp_lport;
1048                 LIST_INIT(&phd->phd_pcblist);
1049                 LIST_INSERT_HEAD(pcbporthash, phd, phd_hash);
1050         }
1051
1052         inp->inp_phd = phd;
1053         LIST_INSERT_HEAD(&phd->phd_pcblist, inp, inp_portlist);
1054
1055         return (0);
1056 }
1057
1058 void
1059 in_pcbinswildcardhash_oncpu(struct inpcb *inp, struct inpcbinfo *pcbinfo)
1060 {
1061         struct inpcontainer *ic;
1062         struct inpcontainerhead *bucket;
1063
1064         bucket = &pcbinfo->wildcardhashbase[
1065             INP_PCBWILDCARDHASH(inp->inp_lport, pcbinfo->wildcardhashmask)];
1066
1067         ic = malloc(sizeof(struct inpcontainer), M_TEMP, M_INTWAIT);
1068         ic->ic_inp = inp;
1069         LIST_INSERT_HEAD(bucket, ic, ic_list);
1070 }
1071
1072 /*
1073  * Insert PCB into wildcard hash table.
1074  */
1075 void
1076 in_pcbinswildcardhash(struct inpcb *inp)
1077 {
1078         struct inpcbinfo *pcbinfo = inp->inp_pcbinfo;
1079
1080         KKASSERT(pcbinfo != NULL);
1081
1082         in_pcbinswildcardhash_oncpu(inp, pcbinfo);
1083         inp->inp_flags |= INP_WILDCARD;
1084 }
1085
1086 void
1087 in_pcbremwildcardhash_oncpu(struct inpcb *inp, struct inpcbinfo *pcbinfo)
1088 {
1089         struct inpcontainer *ic;
1090         struct inpcontainerhead *head;
1091
1092         /* find bucket */
1093         head = &pcbinfo->wildcardhashbase[
1094             INP_PCBWILDCARDHASH(inp->inp_lport, pcbinfo->wildcardhashmask)];
1095
1096         LIST_FOREACH(ic, head, ic_list) {
1097                 if (ic->ic_inp == inp)
1098                         goto found;
1099         }
1100         return;                 /* not found! */
1101
1102 found:
1103         LIST_REMOVE(ic, ic_list);       /* remove container from bucket chain */
1104         free(ic, M_TEMP);               /* deallocate container */
1105 }
1106
1107 /*
1108  * Remove PCB from wildcard hash table.
1109  */
1110 void
1111 in_pcbremwildcardhash(struct inpcb *inp)
1112 {
1113         struct inpcbinfo *pcbinfo = inp->inp_pcbinfo;
1114
1115         KASSERT(inp->inp_flags & INP_WILDCARD, ("inp not wildcard"));
1116         in_pcbremwildcardhash_oncpu(inp, pcbinfo);
1117         inp->inp_flags &= ~INP_WILDCARD;
1118 }
1119
1120 /*
1121  * Remove PCB from various lists.
1122  */
1123 void
1124 in_pcbremlists(inp)
1125         struct inpcb *inp;
1126 {
1127         if (inp->inp_lport) {
1128                 struct inpcbport *phd = inp->inp_phd;
1129
1130                 LIST_REMOVE(inp, inp_portlist);
1131                 if (LIST_FIRST(&phd->phd_pcblist) == NULL) {
1132                         LIST_REMOVE(phd, phd_hash);
1133                         free(phd, M_PCB);
1134                 }
1135         }
1136         if (inp->inp_flags & INP_WILDCARD) {
1137                 in_pcbremwildcardhash(inp);
1138         } else if (inp->inp_flags & INP_CONNECTED) {
1139                 in_pcbremconnhash(inp);
1140         }
1141         LIST_REMOVE(inp, inp_list);
1142         inp->inp_pcbinfo->ipi_count--;
1143 }
1144
1145 int
1146 prison_xinpcb(struct thread *td, struct inpcb *inp)
1147 {
1148         struct ucred *cr;
1149
1150         if (td->td_proc == NULL)
1151                 return (0);
1152         cr = td->td_proc->p_ucred;
1153         if (cr->cr_prison == NULL)
1154                 return (0);
1155         if (ntohl(inp->inp_laddr.s_addr) == cr->cr_prison->pr_ip)
1156                 return (0);
1157         return (1);
1158 }
1159
1160 int
1161 in_pcblist_global(SYSCTL_HANDLER_ARGS)
1162 {
1163         struct inpcbinfo *pcbinfo = arg1;
1164         struct inpcb *inp, *marker;
1165         struct xinpcb xi;
1166         int error, i, n;
1167         inp_gen_t gencnt;
1168
1169         /*
1170          * The process of preparing the TCB list is too time-consuming and
1171          * resource-intensive to repeat twice on every request.
1172          */
1173         if (req->oldptr == NULL) {
1174                 n = pcbinfo->ipi_count;
1175                 req->oldidx = (n + n/8 + 10) * sizeof(struct xinpcb);
1176                 return 0;
1177         }
1178
1179         if (req->newptr != NULL)
1180                 return EPERM;
1181
1182         /*
1183          * OK, now we're committed to doing something.  Re-fetch ipi_count
1184          * after obtaining the generation count.
1185          */
1186         gencnt = pcbinfo->ipi_gencnt;
1187         n = pcbinfo->ipi_count;
1188
1189         marker = malloc(sizeof(struct inpcb), M_TEMP, M_WAITOK|M_ZERO);
1190         marker->inp_flags |= INP_PLACEMARKER;
1191         LIST_INSERT_HEAD(&pcbinfo->pcblisthead, marker, inp_list);
1192
1193         i = 0;
1194         error = 0;
1195
1196         while ((inp = LIST_NEXT(marker, inp_list)) != NULL && i < n) {
1197                 LIST_REMOVE(marker, inp_list);
1198                 LIST_INSERT_AFTER(inp, marker, inp_list);
1199
1200                 if (inp->inp_flags & INP_PLACEMARKER)
1201                         continue;
1202                 if (inp->inp_gencnt > gencnt)
1203                         continue;
1204                 if (prison_xinpcb(req->td, inp))
1205                         continue;
1206                 xi.xi_len = sizeof xi;
1207                 bcopy(inp, &xi.xi_inp, sizeof *inp);
1208                 if (inp->inp_socket)
1209                         sotoxsocket(inp->inp_socket, &xi.xi_socket);
1210                 if ((error = SYSCTL_OUT(req, &xi, sizeof xi)) != 0)
1211                         break;
1212                 ++i;
1213         }
1214         LIST_REMOVE(marker, inp_list);
1215         if (error == 0 && i < n) {
1216                 bzero(&xi, sizeof xi);
1217                 xi.xi_len = sizeof xi;
1218                 while (i < n) {
1219                         error = SYSCTL_OUT(req, &xi, sizeof xi);
1220                         ++i;
1221                 }
1222         }
1223         free(marker, M_TEMP);
1224         return(error);
1225 }