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