lib/sockopt.c

   1 /* setsockopt functions
   2  * Copyright (C) 1999 Kunihiro Ishiguro
   3  *
   4  * This file is part of GNU Zebra.
   5  *
   6  * GNU Zebra is free software; you can redistribute it and/or modify it
   7  * under the terms of the GNU General Public License as published by the
   8  * Free Software Foundation; either version 2, or (at your option) any
   9  * later version.
  10  *
  11  * GNU Zebra is distributed in the hope that it will be useful, but
  12  * WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  * General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License along
  17  * with this program; see the file COPYING; if not, write to the Free Software
  18  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
  19  */
  20
  21 #include <zebra.h>
  22
  23 #ifdef SUNOS_5
  24 #include <ifaddrs.h>
  25 #endif
  26
  27 #include "log.h"
  28 #include "sockopt.h"
  29 #include "sockunion.h"
  30 #include "lib_errors.h"
  31
  32 void setsockopt_so_recvbuf(int sock, int size)
  33 {
  34         int orig_req = size;
  35
  36         while (setsockopt(sock, SOL_SOCKET, SO_RCVBUF, &size, sizeof(size))
  37                == -1)
  38                 size /= 2;
  39
  40         if (size != orig_req)
  41                 flog_err(LIB_ERR_SOCKET,
  42                          "%s: fd %d: SO_RCVBUF set to %d (requested %d)",
  43                          __func__, sock, size, orig_req);
  44 }
  45
  46 void setsockopt_so_sendbuf(const int sock, int size)
  47 {
  48         int orig_req = size;
  49
  50         while (setsockopt(sock, SOL_SOCKET, SO_SNDBUF, &size, sizeof(size))
  51                == -1)
  52                 size /= 2;
  53
  54         if (size != orig_req)
  55                 flog_err(LIB_ERR_SOCKET,
  56                          "%s: fd %d: SO_SNDBUF set to %d (requested %d)",
  57                          __func__, sock, size, orig_req);
  58 }
  59
  60 int getsockopt_so_sendbuf(const int sock)
  61 {
  62         uint32_t optval;
  63         socklen_t optlen = sizeof(optval);
  64         int ret = getsockopt(sock, SOL_SOCKET, SO_SNDBUF, (char *)&optval,
  65                              &optlen);
  66         if (ret < 0) {
  67                 flog_err_sys(LIB_ERR_SYSTEM_CALL,
  68                              "fd %d: can't getsockopt SO_SNDBUF: %d (%s)", sock,
  69                              errno, safe_strerror(errno));
  70                 return ret;
  71         }
  72         return optval;
  73 }
  74
  75 static void *getsockopt_cmsg_data(struct msghdr *msgh, int level, int type)
  76 {
  77         struct cmsghdr *cmsg;
  78         void *ptr = NULL;
  79
  80         for (cmsg = CMSG_FIRSTHDR(msgh); cmsg != NULL;
  81              cmsg = CMSG_NXTHDR(msgh, cmsg))
  82                 if (cmsg->cmsg_level == level && cmsg->cmsg_type == type)
  83                         return (ptr = CMSG_DATA(cmsg));
  84
  85         return NULL;
  86 }
  87
  88 /* Set IPv6 packet info to the socket. */
  89 int setsockopt_ipv6_pktinfo(int sock, int val)
  90 {
  91         int ret;
  92
  93 #ifdef IPV6_RECVPKTINFO /*2292bis-01*/
  94         ret = setsockopt(sock, IPPROTO_IPV6, IPV6_RECVPKTINFO, &val,
  95                          sizeof(val));
  96         if (ret < 0)
  97                 flog_err(LIB_ERR_SOCKET,
  98                          "can't setsockopt IPV6_RECVPKTINFO : %s",
  99                          safe_strerror(errno));
 100 #else  /*RFC2292*/
 101         ret = setsockopt(sock, IPPROTO_IPV6, IPV6_PKTINFO, &val, sizeof(val));
 102         if (ret < 0)
 103                 flog_err(LIB_ERR_SOCKET, "can't setsockopt IPV6_PKTINFO : %s",
 104                          safe_strerror(errno));
 105 #endif /* INIA_IPV6 */
 106         return ret;
 107 }
 108
 109 /* Set multicast hops val to the socket. */
 110 int setsockopt_ipv6_checksum(int sock, int val)
 111 {
 112         int ret;
 113
 114 #ifdef GNU_LINUX
 115         ret = setsockopt(sock, IPPROTO_RAW, IPV6_CHECKSUM, &val, sizeof(val));
 116 #else
 117         ret = setsockopt(sock, IPPROTO_IPV6, IPV6_CHECKSUM, &val, sizeof(val));
 118 #endif /* GNU_LINUX */
 119         if (ret < 0)
 120                 flog_err(LIB_ERR_SOCKET, "can't setsockopt IPV6_CHECKSUM");
 121         return ret;
 122 }
 123
 124 /* Set multicast hops val to the socket. */
 125 int setsockopt_ipv6_multicast_hops(int sock, int val)
 126 {
 127         int ret;
 128
 129         ret = setsockopt(sock, IPPROTO_IPV6, IPV6_MULTICAST_HOPS, &val,
 130                          sizeof(val));
 131         if (ret < 0)
 132                 flog_err(LIB_ERR_SOCKET,
 133                          "can't setsockopt IPV6_MULTICAST_HOPS");
 134         return ret;
 135 }
 136
 137 /* Set multicast hops val to the socket. */
 138 int setsockopt_ipv6_unicast_hops(int sock, int val)
 139 {
 140         int ret;
 141
 142         ret = setsockopt(sock, IPPROTO_IPV6, IPV6_UNICAST_HOPS, &val,
 143                          sizeof(val));
 144         if (ret < 0)
 145                 flog_err(LIB_ERR_SOCKET, "can't setsockopt IPV6_UNICAST_HOPS");
 146         return ret;
 147 }
 148
 149 int setsockopt_ipv6_hoplimit(int sock, int val)
 150 {
 151         int ret;
 152
 153 #ifdef IPV6_RECVHOPLIMIT /*2292bis-01*/
 154         ret = setsockopt(sock, IPPROTO_IPV6, IPV6_RECVHOPLIMIT, &val,
 155                          sizeof(val));
 156         if (ret < 0)
 157                 flog_err(LIB_ERR_SOCKET, "can't setsockopt IPV6_RECVHOPLIMIT");
 158 #else /*RFC2292*/
 159         ret = setsockopt(sock, IPPROTO_IPV6, IPV6_HOPLIMIT, &val, sizeof(val));
 160         if (ret < 0)
 161                 flog_err(LIB_ERR_SOCKET, "can't setsockopt IPV6_HOPLIMIT");
 162 #endif
 163         return ret;
 164 }
 165
 166 /* Set multicast loop zero to the socket. */
 167 int setsockopt_ipv6_multicast_loop(int sock, int val)
 168 {
 169         int ret;
 170
 171         ret = setsockopt(sock, IPPROTO_IPV6, IPV6_MULTICAST_LOOP, &val,
 172                          sizeof(val));
 173         if (ret < 0)
 174                 flog_err(LIB_ERR_SOCKET,
 175                          "can't setsockopt IPV6_MULTICAST_LOOP");
 176         return ret;
 177 }
 178
 179 static int getsockopt_ipv6_ifindex(struct msghdr *msgh)
 180 {
 181         struct in6_pktinfo *pktinfo;
 182
 183         pktinfo = getsockopt_cmsg_data(msgh, IPPROTO_IPV6, IPV6_PKTINFO);
 184
 185         return pktinfo->ipi6_ifindex;
 186 }
 187
 188 int setsockopt_ipv6_tclass(int sock, int tclass)
 189 {
 190         int ret = 0;
 191
 192 #ifdef IPV6_TCLASS /* RFC3542 */
 193         ret = setsockopt(sock, IPPROTO_IPV6, IPV6_TCLASS, &tclass,
 194                          sizeof(tclass));
 195         if (ret < 0)
 196                 flog_err(LIB_ERR_SOCKET,
 197                          "Can't set IPV6_TCLASS option for fd %d to %#x: %s",
 198                          sock, tclass, safe_strerror(errno));
 199 #endif
 200         return ret;
 201 }
 202
 203 /*
 204  * Process multicast socket options for IPv4 in an OS-dependent manner.
 205  * Supported options are IP_{ADD,DROP}_MEMBERSHIP.
 206  *
 207  * Many operating systems have a limit on the number of groups that
 208  * can be joined per socket (where each group and local address
 209  * counts).  This impacts OSPF, which joins groups on each interface
 210  * using a single socket.  The limit is typically 20, derived from the
 211  * original BSD multicast implementation.  Some systems have
 212  * mechanisms for increasing this limit.
 213  *
 214  * In many 4.4BSD-derived systems, multicast group operations are not
 215  * allowed on interfaces that are not UP.  Thus, a previous attempt to
 216  * leave the group may have failed, leaving it still joined, and we
 217  * drop/join quietly to recover.  This may not be necessary, but aims to
 218  * defend against unknown behavior in that we will still return an error
 219  * if the second join fails.  It is not clear how other systems
 220  * (e.g. Linux, Solaris) behave when leaving groups on down interfaces,
 221  * but this behavior should not be harmful if they behave the same way,
 222  * allow leaves, or implicitly leave all groups joined to down interfaces.
 223  */
 224 int setsockopt_ipv4_multicast(int sock, int optname, struct in_addr if_addr,
 225                               unsigned int mcast_addr, ifindex_t ifindex)
 226 {
 227 #ifdef HAVE_RFC3678
 228         struct group_req gr;
 229         struct sockaddr_in *si;
 230         int ret;
 231         memset(&gr, 0, sizeof(gr));
 232         si = (struct sockaddr_in *)&gr.gr_group;
 233         gr.gr_interface = ifindex;
 234         si->sin_family = AF_INET;
 235 #ifdef HAVE_STRUCT_SOCKADDR_IN_SIN_LEN
 236         si->sin_len = sizeof(struct sockaddr_in);
 237 #endif /* HAVE_STRUCT_SOCKADDR_IN_SIN_LEN */
 238         si->sin_addr.s_addr = mcast_addr;
 239         ret = setsockopt(sock, IPPROTO_IP,
 240                          (optname == IP_ADD_MEMBERSHIP) ? MCAST_JOIN_GROUP
 241                                                         : MCAST_LEAVE_GROUP,
 242                          (void *)&gr, sizeof(gr));
 243         if ((ret < 0) && (optname == IP_ADD_MEMBERSHIP)
 244             && (errno == EADDRINUSE)) {
 245                 setsockopt(sock, IPPROTO_IP, MCAST_LEAVE_GROUP, (void *)&gr,
 246                            sizeof(gr));
 247                 ret = setsockopt(sock, IPPROTO_IP, MCAST_JOIN_GROUP,
 248                                  (void *)&gr, sizeof(gr));
 249         }
 250         return ret;
 251
 252 #elif defined(HAVE_STRUCT_IP_MREQN_IMR_IFINDEX) && !defined(__FreeBSD__)
 253         struct ip_mreqn mreqn;
 254         int ret;
 255
 256         assert(optname == IP_ADD_MEMBERSHIP || optname == IP_DROP_MEMBERSHIP);
 257         memset(&mreqn, 0, sizeof(mreqn));
 258
 259         mreqn.imr_multiaddr.s_addr = mcast_addr;
 260         mreqn.imr_ifindex = ifindex;
 261
 262         ret = setsockopt(sock, IPPROTO_IP, optname, (void *)&mreqn,
 263                          sizeof(mreqn));
 264         if ((ret < 0) && (optname == IP_ADD_MEMBERSHIP)
 265             && (errno == EADDRINUSE)) {
 266                 /* see above: handle possible problem when interface comes back
 267                  * up */
 268                 char buf[1][INET_ADDRSTRLEN];
 269                 zlog_info(
 270                         "setsockopt_ipv4_multicast attempting to drop and "
 271                         "re-add (fd %d, mcast %s, ifindex %u)",
 272                         sock, inet_ntop(AF_INET, &mreqn.imr_multiaddr, buf[0],
 273                                         sizeof(buf[0])),
 274                         ifindex);
 275                 setsockopt(sock, IPPROTO_IP, IP_DROP_MEMBERSHIP, (void *)&mreqn,
 276                            sizeof(mreqn));
 277                 ret = setsockopt(sock, IPPROTO_IP, IP_ADD_MEMBERSHIP,
 278                                  (void *)&mreqn, sizeof(mreqn));
 279         }
 280         return ret;
 281
 282 /* Example defines for another OS, boilerplate off other code in this
 283    function, AND handle optname as per other sections for consistency !! */
 284 /* #elif  defined(BOGON_NIX) && EXAMPLE_VERSION_CODE > -100000 */
 285 /* Add your favourite OS here! */
 286
 287 #elif defined(HAVE_BSD_STRUCT_IP_MREQ_HACK) /* #if OS_TYPE */
 288         /* standard BSD API */
 289
 290         struct ip_mreq mreq;
 291         int ret;
 292
 293         assert(optname == IP_ADD_MEMBERSHIP || optname == IP_DROP_MEMBERSHIP);
 294
 295
 296         memset(&mreq, 0, sizeof(mreq));
 297         mreq.imr_multiaddr.s_addr = mcast_addr;
 298 #if !defined __OpenBSD__
 299         mreq.imr_interface.s_addr = htonl(ifindex);
 300 #else
 301         mreq.imr_interface.s_addr = if_addr.s_addr;
 302 #endif
 303
 304         ret = setsockopt(sock, IPPROTO_IP, optname, (void *)&mreq,
 305                          sizeof(mreq));
 306         if ((ret < 0) && (optname == IP_ADD_MEMBERSHIP)
 307             && (errno == EADDRINUSE)) {
 308                 /* see above: handle possible problem when interface comes back
 309                  * up */
 310                 char buf[1][INET_ADDRSTRLEN];
 311                 zlog_info(
 312                         "setsockopt_ipv4_multicast attempting to drop and "
 313                         "re-add (fd %d, mcast %s, ifindex %u)",
 314                         sock, inet_ntop(AF_INET, &mreq.imr_multiaddr, buf[0],
 315                                         sizeof(buf[0])),
 316                         ifindex);
 317                 setsockopt(sock, IPPROTO_IP, IP_DROP_MEMBERSHIP, (void *)&mreq,
 318                            sizeof(mreq));
 319                 ret = setsockopt(sock, IPPROTO_IP, IP_ADD_MEMBERSHIP,
 320                                  (void *)&mreq, sizeof(mreq));
 321         }
 322         return ret;
 323
 324 #else
 325 #error "Unsupported multicast API"
 326 #endif /* #if OS_TYPE */
 327 }
 328
 329 /*
 330  * Set IP_MULTICAST_IF socket option in an OS-dependent manner.
 331  */
 332 int setsockopt_ipv4_multicast_if(int sock, struct in_addr if_addr,
 333                                  ifindex_t ifindex)
 334 {
 335
 336 #ifdef HAVE_STRUCT_IP_MREQN_IMR_IFINDEX
 337         struct ip_mreqn mreqn;
 338         memset(&mreqn, 0, sizeof(mreqn));
 339
 340         mreqn.imr_ifindex = ifindex;
 341         return setsockopt(sock, IPPROTO_IP, IP_MULTICAST_IF, (void *)&mreqn,
 342                           sizeof(mreqn));
 343
 344 /* Example defines for another OS, boilerplate off other code in this
 345    function */
 346 /* #elif  defined(BOGON_NIX) && EXAMPLE_VERSION_CODE > -100000 */
 347 /* Add your favourite OS here! */
 348 #elif defined(HAVE_BSD_STRUCT_IP_MREQ_HACK)
 349         struct in_addr m;
 350
 351 #if !defined __OpenBSD__
 352         m.s_addr = htonl(ifindex);
 353 #else
 354         m.s_addr = if_addr.s_addr;
 355 #endif
 356
 357         return setsockopt(sock, IPPROTO_IP, IP_MULTICAST_IF, (void *)&m,
 358                           sizeof(m));
 359 #elif defined(SUNOS_5)
 360         char ifname[IF_NAMESIZE];
 361         struct ifaddrs *ifa, *ifap;
 362         struct in_addr ifaddr;
 363
 364         if (if_indextoname(ifindex, ifname) == NULL)
 365                 return -1;
 366
 367         if (getifaddrs(&ifa) != 0)
 368                 return -1;
 369
 370         for (ifap = ifa; ifap != NULL; ifap = ifap->ifa_next) {
 371                 struct sockaddr_in *sa;
 372
 373                 if (strcmp(ifap->ifa_name, ifname) != 0)
 374                         continue;
 375                 if (ifap->ifa_addr->sa_family != AF_INET)
 376                         continue;
 377                 sa = (struct sockaddr_in *)ifap->ifa_addr;
 378                 memcpy(&ifaddr, &sa->sin_addr, sizeof(ifaddr));
 379                 break;
 380         }
 381
 382         freeifaddrs(ifa);
 383         if (!ifap) /* This means we did not find an IP */
 384                 return -1;
 385
 386         return setsockopt(sock, IPPROTO_IP, IP_MULTICAST_IF, (void *)&ifaddr,
 387                           sizeof(ifaddr));
 388 #else
 389 #error "Unsupported multicast API"
 390 #endif
 391 }
 392
 393 int setsockopt_ipv4_multicast_loop(int sock, uint8_t val)
 394 {
 395         int ret;
 396
 397         ret = setsockopt(sock, IPPROTO_IP, IP_MULTICAST_LOOP, (void *)&val,
 398                          sizeof(val));
 399         if (ret < 0)
 400                 flog_err(LIB_ERR_SOCKET, "can't setsockopt IP_MULTICAST_LOOP");
 401
 402         return ret;
 403 }
 404
 405 static int setsockopt_ipv4_ifindex(int sock, ifindex_t val)
 406 {
 407         int ret;
 408
 409 #if defined(IP_PKTINFO)
 410         if ((ret = setsockopt(sock, IPPROTO_IP, IP_PKTINFO, &val, sizeof(val)))
 411             < 0)
 412                 flog_err(LIB_ERR_SOCKET,
 413                          "Can't set IP_PKTINFO option for fd %d to %d: %s",
 414                          sock, val, safe_strerror(errno));
 415 #elif defined(IP_RECVIF)
 416         if ((ret = setsockopt(sock, IPPROTO_IP, IP_RECVIF, &val, sizeof(val)))
 417             < 0)
 418                 flog_err(LIB_ERR_SOCKET,
 419                          "Can't set IP_RECVIF option for fd %d to %d: %s", sock,
 420                          val, safe_strerror(errno));
 421 #else
 422 #warning "Neither IP_PKTINFO nor IP_RECVIF is available."
 423 #warning "Will not be able to receive link info."
 424 #warning "Things might be seriously broken.."
 425         /* XXX Does this ever happen?  Should there be a zlog_warn message here?
 426          */
 427         ret = -1;
 428 #endif
 429         return ret;
 430 }
 431
 432 int setsockopt_ipv4_tos(int sock, int tos)
 433 {
 434         int ret;
 435
 436         ret = setsockopt(sock, IPPROTO_IP, IP_TOS, &tos, sizeof(tos));
 437         if (ret < 0)
 438                 flog_err(LIB_ERR_SOCKET,
 439                          "Can't set IP_TOS option for fd %d to %#x: %s", sock,
 440                          tos, safe_strerror(errno));
 441         return ret;
 442 }
 443
 444
 445 int setsockopt_ifindex(int af, int sock, ifindex_t val)
 446 {
 447         int ret = -1;
 448
 449         switch (af) {
 450         case AF_INET:
 451                 ret = setsockopt_ipv4_ifindex(sock, val);
 452                 break;
 453         case AF_INET6:
 454                 ret = setsockopt_ipv6_pktinfo(sock, val);
 455                 break;
 456         default:
 457                 flog_err(LIB_ERR_DEVELOPMENT,
 458                          "setsockopt_ifindex: unknown address family %d", af);
 459         }
 460         return ret;
 461 }
 462
 463 /*
 464  * Requires: msgh is not NULL and points to a valid struct msghdr, which
 465  * may or may not have control data about the incoming interface.
 466  *
 467  * Returns the interface index (small integer >= 1) if it can be
 468  * determined, or else 0.
 469  */
 470 static ifindex_t getsockopt_ipv4_ifindex(struct msghdr *msgh)
 471 {
 472         ifindex_t ifindex;
 473
 474 #if defined(IP_PKTINFO)
 475         /* Linux pktinfo based ifindex retrieval */
 476         struct in_pktinfo *pktinfo;
 477
 478         pktinfo = (struct in_pktinfo *)getsockopt_cmsg_data(msgh, IPPROTO_IP,
 479                                                             IP_PKTINFO);
 480
 481         /* getsockopt_ifindex() will forward this, being 0 "not found" */
 482         if (pktinfo == NULL)
 483                 return 0;
 484
 485         ifindex = pktinfo->ipi_ifindex;
 486
 487 #elif defined(IP_RECVIF)
 488
 489 /* retrieval based on IP_RECVIF */
 490
 491 #ifndef SUNOS_5
 492         /* BSD systems use a sockaddr_dl as the control message payload. */
 493         struct sockaddr_dl *sdl;
 494 #else
 495         /* SUNOS_5 uses an integer with the index. */
 496         ifindex_t *ifindex_p;
 497 #endif /* SUNOS_5 */
 498
 499 #ifndef SUNOS_5
 500         /* BSD */
 501         sdl = (struct sockaddr_dl *)getsockopt_cmsg_data(msgh, IPPROTO_IP,
 502                                                          IP_RECVIF);
 503         if (sdl != NULL)
 504                 ifindex = sdl->sdl_index;
 505         else
 506                 ifindex = 0;
 507 #else
 508         /*
 509          * Solaris.  On Solaris 8, IP_RECVIF is defined, but the call to
 510          * enable it fails with errno=99, and the struct msghdr has
 511          * controllen 0.
 512          */
 513         ifindex_p = (uint_t *)getsockopt_cmsg_data(msgh, IPPROTO_IP, IP_RECVIF);
 514         if (ifindex_p != NULL)
 515                 ifindex = *ifindex_p;
 516         else
 517                 ifindex = 0;
 518 #endif /* SUNOS_5 */
 519
 520 #else
 521 /*
 522  * Neither IP_PKTINFO nor IP_RECVIF defined - warn at compile time.
 523  * XXX Decide if this is a core service, or if daemons have to cope.
 524  * Since Solaris 8 and OpenBSD seem not to provide it, it seems that
 525  * daemons have to cope.
 526  */
 527 #warning "getsockopt_ipv4_ifindex: Neither IP_PKTINFO nor IP_RECVIF defined."
 528 #warning "Some daemons may fail to operate correctly!"
 529         ifindex = 0;
 530
 531 #endif /* IP_PKTINFO */
 532
 533         return ifindex;
 534 }
 535
 536 /* return ifindex, 0 if none found */
 537 ifindex_t getsockopt_ifindex(int af, struct msghdr *msgh)
 538 {
 539         switch (af) {
 540         case AF_INET:
 541                 return (getsockopt_ipv4_ifindex(msgh));
 542                 break;
 543         case AF_INET6:
 544                 return (getsockopt_ipv6_ifindex(msgh));
 545                 break;
 546         default:
 547                 flog_err(LIB_ERR_DEVELOPMENT,
 548                          "getsockopt_ifindex: unknown address family %d", af);
 549                 return 0;
 550         }
 551 }
 552
 553 /* swab iph between order system uses for IP_HDRINCL and host order */
 554 void sockopt_iphdrincl_swab_htosys(struct ip *iph)
 555 {
 556 /* BSD and derived take iph in network order, except for
 557  * ip_len and ip_off
 558  */
 559 #ifndef HAVE_IP_HDRINCL_BSD_ORDER
 560         iph->ip_len = htons(iph->ip_len);
 561         iph->ip_off = htons(iph->ip_off);
 562 #endif /* HAVE_IP_HDRINCL_BSD_ORDER */
 563
 564         iph->ip_id = htons(iph->ip_id);
 565 }
 566
 567 void sockopt_iphdrincl_swab_systoh(struct ip *iph)
 568 {
 569 #ifndef HAVE_IP_HDRINCL_BSD_ORDER
 570         iph->ip_len = ntohs(iph->ip_len);
 571         iph->ip_off = ntohs(iph->ip_off);
 572 #endif /* HAVE_IP_HDRINCL_BSD_ORDER */
 573
 574         iph->ip_id = ntohs(iph->ip_id);
 575 }
 576
 577 int sockopt_tcp_rtt(int sock)
 578 {
 579 #ifdef TCP_INFO
 580         struct tcp_info ti;
 581         socklen_t len = sizeof(ti);
 582
 583         if (getsockopt(sock, IPPROTO_TCP, TCP_INFO, &ti, &len) != 0)
 584                 return 0;
 585
 586         return ti.tcpi_rtt / 1000;
 587 #else
 588         return 0;
 589 #endif
 590 }
 591
 592 int sockopt_tcp_signature(int sock, union sockunion *su, const char *password)
 593 {
 594 #if HAVE_DECL_TCP_MD5SIG
 595         int ret;
 596 #ifndef GNU_LINUX
 597         /*
 598          * XXX Need to do PF_KEY operation here to add/remove an SA entry,
 599          * and add/remove an SP entry for this peer's packet flows also.
 600          */
 601         int md5sig = password && *password ? 1 : 0;
 602 #else
 603         int keylen = password ? strlen(password) : 0;
 604         struct tcp_md5sig md5sig;
 605         union sockunion *su2, *susock;
 606
 607         /* Figure out whether the socket and the sockunion are the same family..
 608          * adding AF_INET to AF_INET6 needs to be v4 mapped, you'd think..
 609          */
 610         if (!(susock = sockunion_getsockname(sock)))
 611                 return -1;
 612
 613         if (susock->sa.sa_family == su->sa.sa_family)
 614                 su2 = su;
 615         else {
 616                 /* oops.. */
 617                 su2 = susock;
 618
 619                 if (su2->sa.sa_family == AF_INET) {
 620                         sockunion_free(susock);
 621                         return 0;
 622                 }
 623
 624                 /* If this does not work, then all users of this sockopt will
 625                  * need to
 626                  * differentiate between IPv4 and IPv6, and keep seperate
 627                  * sockets for
 628                  * each.
 629                  *
 630                  * Sadly, it doesn't seem to work at present. It's unknown
 631                  * whether
 632                  * this is a bug or not.
 633                  */
 634                 if (su2->sa.sa_family == AF_INET6
 635                     && su->sa.sa_family == AF_INET) {
 636                         su2->sin6.sin6_family = AF_INET6;
 637                         /* V4Map the address */
 638                         memset(&su2->sin6.sin6_addr, 0,
 639                                sizeof(struct in6_addr));
 640                         su2->sin6.sin6_addr.s6_addr32[2] = htonl(0xffff);
 641                         memcpy(&su2->sin6.sin6_addr.s6_addr32[3],
 642                                &su->sin.sin_addr, 4);
 643                 }
 644         }
 645
 646         memset(&md5sig, 0, sizeof(md5sig));
 647         memcpy(&md5sig.tcpm_addr, su2, sizeof(*su2));
 648         md5sig.tcpm_keylen = keylen;
 649         if (keylen)
 650                 memcpy(md5sig.tcpm_key, password, keylen);
 651         sockunion_free(susock);
 652 #endif /* GNU_LINUX */
 653         if ((ret = setsockopt(sock, IPPROTO_TCP, TCP_MD5SIG, &md5sig,
 654                               sizeof md5sig))
 655             < 0) {
 656                 /* ENOENT is harmless.  It is returned when we clear a password
 657                    for which
 658                    one was not previously set. */
 659                 if (ENOENT == errno)
 660                         ret = 0;
 661                 else
 662                         flog_err_sys(
 663                                 LIB_ERR_SYSTEM_CALL,
 664                                 "sockopt_tcp_signature: setsockopt(%d): %s",
 665                                 sock, safe_strerror(errno));
 666         }
 667         return ret;
 668 #else  /* HAVE_TCP_MD5SIG */
 669         return -2;
 670 #endif /* !HAVE_TCP_MD5SIG */
 671 }