ircd/os_generic.c

   1 /*
   2  * IRC - Internet Relay Chat, ircd/os_generic.c
   3  * Copyright (C) 1999 Thomas Helvey
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 1, or (at your option)
   8  * any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program; if not, write to the Free Software
  17  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  18  */
  19 /** @file
  20  * @brief Implementation of OS-dependent operations.
  21  * @version $Id: os_generic.c,v 1.23.2.7 2007/02/28 22:37:08 entrope Exp $
  22  */
  23 #include "config.h"
  24
  25 #ifdef IRCU_SOLARIS
  26 /* Solaris requires C99 support for SUSv3, but C99 support breaks other
  27  * parts of the build.  So fall back to SUSv2, but request IPv6 support
  28  * by defining __EXTENSIONS__.
  29  */
  30 #define _XOPEN_SOURCE   500
  31 #define __EXTENSIONS__  1
  32 #elif defined(__FreeBSD__) && __FreeBSD__ >= 5
  33 /* FreeBSD 6.0 requires SUSv3 to support IPv6 -- but if you ask for
  34  * that specifically (by defining _XOPEN_SOURCE to anything at all),
  35  * they cleverly hide IPPROTO_IPV6.  If you don't ask for anything,
  36  * they give you everything.
  37  */
  38 #else
  39 #define _XOPEN_SOURCE   600
  40 #endif
  41
  42 #include "ircd_osdep.h"
  43 #include "msgq.h"
  44 #include "ircd_log.h"
  45 #include "res.h"
  46 #include "s_bsd.h"
  47 #include "sys.h"
  48
  49 /* Include file dependency notes:
  50  * FreeBSD requires struct timeval from sys/time.h before struct
  51  * rusage in sys/resource.h.
  52  * Solaris requires sys/time.h before struct rusage (indirectly) in
  53  * netinet/in.h.
  54  */
  55 /* #include <assert.h> -- Now using assert in ircd_log.h */
  56 #include <errno.h>
  57 #include <fcntl.h>
  58 #include <limits.h>
  59 #include <stdio.h>
  60 #include <string.h>
  61 #include <sys/ioctl.h>
  62 #include <sys/types.h>
  63 #include <sys/time.h>
  64 #include <netinet/in.h>
  65 #include <sys/resource.h>
  66 #include <sys/socket.h>
  67 #include <sys/uio.h>
  68
  69 #if HAVE_SYS_PARAM_H
  70 #include <sys/param.h>
  71 #endif
  72
  73 #if HAVE_UNISTD_H
  74 #include <unistd.h>
  75 #endif
  76
  77 #if defined(IPV6_BINDV6ONLY) &&!defined(IPV6_V6ONLY)
  78 # define IPV6_V6ONLY IPV6_BINDV6ONLY
  79 #endif
  80
  81 #ifndef IOV_MAX
  82 #define IOV_MAX 16      /**< minimum required length of an iovec array */
  83 #endif
  84
  85 #ifdef HPUX
  86 #include <sys/syscall.h>
  87 #define getrusage(a,b) syscall(SYS_GETRUSAGE, a, b)
  88 #endif
  89
  90 static int is_blocked(int error)
  91 {
  92   return EWOULDBLOCK == error
  93 #ifdef ENOMEM
  94     || ENOMEM == error
  95 #endif
  96 #ifdef ENOBUFS
  97     || ENOBUFS == error
  98 #endif
  99     || EAGAIN == error;
 100 }
 101
 102 static void sockaddr_in_to_irc(const struct sockaddr_in *v4,
 103                                struct irc_sockaddr *irc)
 104 {
 105     memset(&irc->addr, 0, 5*sizeof(int16_t));
 106     irc->addr.in6_16[5] = 0xffff;
 107     memcpy(&irc->addr.in6_16[6], &v4->sin_addr, sizeof(v4->sin_addr));
 108     irc->port = ntohs(v4->sin_port);
 109 }
 110
 111
 112 #ifdef IPV6
 113 /** Native socket address type. */
 114 #define sockaddr_native sockaddr_in6
 115 /** Field name inside sockaddr_native to find address family. */
 116 #define sn_family sin6_family
 117
 118 /** Convert native socket address to IRC format.
 119  * @param[in] v6 Native socket address.
 120  * @param[out] irc IRC format socket address.
 121  */
 122 void sockaddr_to_irc(const struct sockaddr_in6 *v6, struct irc_sockaddr *irc)
 123 {
 124     if (v6->sin6_family == AF_INET6) {
 125         memcpy(&irc->addr.in6_16[0], &v6->sin6_addr, sizeof(v6->sin6_addr));
 126         irc->port = ntohs(v6->sin6_port);
 127     }
 128     else if (v6->sin6_family == AF_INET) {
 129         sockaddr_in_to_irc((struct sockaddr_in *)v6, irc);
 130     }
 131     else assert(0 && "Unhandled native address family");
 132 }
 133
 134 /** Convert IRC socket address to native format.
 135  * @param[out] v6 Native socket address.
 136  * @param[in] irc IRC socket address.
 137  * @param[in] compat_fd If non-negative, an FD specifying address family.
 138  * @return Length of address written to \a v6.
 139  */
 140 int sockaddr_from_irc(struct sockaddr_in6 *v6, const struct irc_sockaddr *irc, int compat_fd, int family)
 141 {
 142     struct sockaddr_in6 sin6;
 143     socklen_t slen;
 144
 145     assert(irc != 0);
 146     slen = sizeof(sin6);
 147     if (family) {
 148         /* accept whatever user specified */
 149     } else if ((0 <= compat_fd)
 150         && (0 == getsockname(compat_fd, (struct sockaddr*)&sin6, &slen)))
 151         family = sin6.sin6_family;
 152     else if ((irc == &VirtualHost_v4) || irc_in_addr_is_ipv4(&irc->addr))
 153         family = AF_INET;
 154     else
 155         family = AF_INET6;
 156
 157     memset(v6, 0, sizeof(*v6));
 158     if (family == AF_INET) {
 159         struct sockaddr_in *v4 = (struct sockaddr_in*)v6;
 160         v4->sin_family = AF_INET;
 161         memcpy(&v4->sin_addr, &irc->addr.in6_16[6], sizeof(v4->sin_addr));
 162         v4->sin_port = htons(irc->port);
 163         return sizeof(*v4);
 164     }
 165     else {
 166         v6->sin6_family = AF_INET6;
 167         memcpy(&v6->sin6_addr, &irc->addr.in6_16[0], sizeof(v6->sin6_addr));
 168         v6->sin6_port = htons(irc->port);
 169         return sizeof(*v6);
 170     }
 171 }
 172
 173 #else
 174 #define sockaddr_native sockaddr_in
 175 #define sn_family sin_family
 176 #define sockaddr_to_irc sockaddr_in_to_irc
 177
 178 int sockaddr_from_irc(struct sockaddr_in *v4, const struct irc_sockaddr *irc, int compat_fd, int family)
 179 {
 180     assert(irc != 0);
 181     memset(v4, 0, sizeof(*v4));
 182     v4->sin_family = AF_INET;
 183     if (irc) {
 184         assert(!irc->addr.in6_16[0] && !irc->addr.in6_16[1] && !irc->addr.in6_16[2] && !irc->addr.in6_16[3] && !irc->addr.in6_16[4] && (!irc->addr.in6_16[5] || irc->addr.in6_16[5] == 0xffff));
 185         memcpy(&v4->sin_addr, &irc->addr.in6_16[6], sizeof(v4->sin_addr));
 186         v4->sin_port = htons(irc->port);
 187     }
 188     (void)compat_fd; (void)family;
 189     return sizeof(*v4);
 190 }
 191
 192 #endif
 193
 194 #ifdef DEBUGMODE
 195 /** Send resource usage information to an enumerator function.
 196  * @param[in] cptr Client requesting information.
 197  * @param[in] uptime Wall time in seconds since the server started.
 198  * @param[in] enumerator Function to call to send a line to \a cptr.
 199  * @return Zero if some usage reports could not be sent, non-zero on success.
 200  */
 201 int os_get_rusage(struct Client *cptr, int uptime, EnumFn enumerator)
 202 {
 203 #ifdef HAVE_GETRUSAGE
 204   char buf[256];
 205   struct rusage rus;
 206   time_t secs;
 207
 208 #ifdef  hz
 209 #  define hzz hz
 210 #else
 211 #  ifdef HZ
 212 #    define hzz HZ
 213 #  else
 214   int hzz = 1;
 215 #  ifdef HPUX
 216   hzz = sysconf(_SC_CLK_TCK);
 217 #  endif
 218 #endif
 219 #endif
 220
 221   assert(0 != enumerator);
 222   if (getrusage(RUSAGE_SELF, &rus) == -1)
 223     return 0;
 224
 225   secs = rus.ru_utime.tv_sec + rus.ru_stime.tv_sec;
 226   if (secs == 0)
 227     secs = 1;
 228
 229   sprintf(buf, "CPU Secs %ld:%ld User %ld:%ld System %ld:%ld",
 230           (long)(secs / 60), (long)(secs % 60),
 231           rus.ru_utime.tv_sec / 60, rus.ru_utime.tv_sec % 60,
 232           rus.ru_stime.tv_sec / 60, rus.ru_stime.tv_sec % 60);
 233   (*enumerator)(cptr, buf);
 234
 235   sprintf(buf, "RSS %ld ShMem %ld Data %ld Stack %ld",
 236           rus.ru_maxrss,
 237           rus.ru_ixrss / (uptime * hzz), rus.ru_idrss / (uptime * hzz),
 238           rus.ru_isrss / (uptime * hzz));
 239   (*enumerator)(cptr, buf);
 240
 241   sprintf(buf, "Swaps %ld Reclaims %ld Faults %ld",
 242           rus.ru_nswap, rus.ru_minflt, rus.ru_majflt);
 243   (*enumerator)(cptr, buf);
 244
 245   sprintf(buf, "Block in %ld out %ld", rus.ru_inblock, rus.ru_oublock);
 246   (*enumerator)(cptr, buf);
 247
 248   sprintf(buf, "Msg Rcv %ld Send %ld", rus.ru_msgrcv, rus.ru_msgsnd);
 249   (*enumerator)(cptr, buf);
 250
 251   sprintf(buf, "Signals %ld Context Vol. %ld Invol %ld",
 252           rus.ru_nsignals, rus.ru_nvcsw, rus.ru_nivcsw);
 253   (*enumerator)(cptr, buf);
 254
 255 #else /* HAVE_GETRUSAGE */
 256 #if HAVE_TIMES
 257   char buf[256];
 258   struct tms tmsbuf;
 259   time_t secs, mins;
 260   int hzz = 1, ticpermin;
 261   int umin, smin, usec, ssec;
 262
 263   assert(0 != enumerator);
 264 #ifdef HPUX
 265   hzz = sysconf(_SC_CLK_TCK);
 266 #endif
 267   ticpermin = hzz * 60;
 268
 269   umin = tmsbuf.tms_utime / ticpermin;
 270   usec = (tmsbuf.tms_utime % ticpermin) / (float)hzz;
 271   smin = tmsbuf.tms_stime / ticpermin;
 272   ssec = (tmsbuf.tms_stime % ticpermin) / (float)hzz;
 273   secs = usec + ssec;
 274   mins = (secs / 60) + umin + smin;
 275   secs %= hzz;
 276
 277   if (times(&tmsbuf) == -1)
 278     return 0;
 279   secs = tmsbuf.tms_utime + tmsbuf.tms_stime;
 280
 281   sprintf(buf, "CPU Secs %d:%d User %d:%d System %d:%d",
 282           mins, secs, umin, usec, smin, ssec);
 283   (*enumerator)(cptr, buf);
 284 #endif /* HAVE_TIMES */
 285 #endif /* HAVE_GETRUSAGE */
 286   return 1;
 287 }
 288 #endif
 289
 290 /** Look up the most recent socket error for a socket file descriptor.
 291  * @param[in] fd File descriptor to check.
 292  * @return Error code from the socket, or 0 if the OS does not support this.
 293  */
 294 int os_get_sockerr(int fd)
 295 {
 296   int    err = 0;
 297 #if defined(SO_ERROR)
 298   unsigned int len = sizeof(err);
 299   getsockopt(fd, SOL_SOCKET, SO_ERROR, &err, &len);
 300 #endif
 301   return err;
 302 }
 303
 304 /** Set a file descriptor to non-blocking mode.
 305  * @param[in] fd %Socket file descriptor.
 306  * @return Non-zero on success, or zero on failure.
 307  */
 308 int os_set_nonblocking(int fd)
 309 {
 310   int res;
 311 #ifndef NBLOCK_SYSV
 312   int nonb = 0;
 313 #endif
 314
 315   /*
 316    * NOTE: consult ALL your relevant manual pages *BEFORE* changing
 317    * these ioctl's. There are quite a few variations on them,
 318    * as can be seen by the PCS one. They are *NOT* all the same.
 319    * Heed this well. - Avalon.
 320    */
 321 #ifdef  NBLOCK_POSIX
 322   nonb |= O_NONBLOCK;
 323 #endif
 324 #ifdef  NBLOCK_BSD
 325   nonb |= O_NDELAY;
 326 #endif
 327 #ifdef  NBLOCK_SYSV
 328   /* This portion of code might also apply to NeXT. -LynX */
 329   res = 1;
 330
 331   if (ioctl(fd, FIONBIO, &res) == -1)
 332     return 0;
 333 #else
 334   if ((res = fcntl(fd, F_GETFL, 0)) == -1)
 335     return 0;
 336   else if (fcntl(fd, F_SETFL, res | nonb) == -1)
 337     return 0;
 338 #endif
 339   return 1;
 340 }
 341
 342 /** Mark a socket's address as reusable.
 343  * @param[in] fd %Socket file descriptor to manipulate.
 344  * @return Non-zero on success, or zero on failure.
 345  */
 346 int os_set_reuseaddr(int fd)
 347 {
 348   unsigned int opt = 1;
 349   return (0 == setsockopt(fd, SOL_SOCKET, SO_REUSEADDR,
 350                           (const char*) &opt, sizeof(opt)));
 351 }
 352
 353 /** Set a socket's send and receive buffer sizes.
 354  * @param[in] fd %Socket file descriptor to manipulate.
 355  * @param[in] ssize New send buffer size.
 356  * @param[in] rsize New receive buffer size.
 357  * @return Non-zero on success, or zero on failure.
 358  */
 359 int os_set_sockbufs(int fd, unsigned int ssize, unsigned int rsize)
 360 {
 361   unsigned int sopt = ssize;
 362   unsigned int ropt = rsize;
 363   return (0 == setsockopt(fd, SOL_SOCKET, SO_RCVBUF,
 364                           (const char*) &ropt, sizeof(ropt)) &&
 365           0 == setsockopt(fd, SOL_SOCKET, SO_SNDBUF,
 366                           (const char*) &sopt, sizeof(sopt)));
 367 }
 368
 369 /** Set a socket's "type of service" value.
 370  * @param[in] fd %Socket file descriptor to manipulate.
 371  * @param[in] tos New type of service value to use.
 372  * @return Non-zero on success, or zero on failure.
 373  */
 374 int os_set_tos(int fd,int tos)
 375 {
 376 #if defined(IP_TOS) && defined(IPPROTO_IP)
 377   unsigned int opt = tos;
 378   return (0 == setsockopt(fd, IPPROTO_IP, IP_TOS, &opt, sizeof(opt)));
 379 #else
 380   return 1;
 381 #endif
 382 }
 383
 384 /** Disable IP options on a socket.
 385  * @param[in] fd %Socket file descriptor to manipulate.
 386  * @return Non-zero on success, or zero on failure.
 387  */
 388 int os_disable_options(int fd)
 389 {
 390 #if defined(IP_OPTIONS) && defined(IPPROTO_IP)
 391   return (0 == setsockopt(fd, IPPROTO_IP, IP_OPTIONS, NULL, 0));
 392 #else
 393   return 1;
 394 #endif
 395 }
 396
 397 /*
 398  * Try and find the correct name to use with getrlimit() for setting the max.
 399  * number of files allowed to be open by this process.
 400  */
 401 #ifdef RLIMIT_FDMAX
 402 #define RLIMIT_FD_MAX   RLIMIT_FDMAX
 403 #else
 404 #ifdef RLIMIT_NOFILE
 405 #define RLIMIT_FD_MAX RLIMIT_NOFILE
 406 #else
 407 #ifdef RLIMIT_OPEN_MAX
 408 #define RLIMIT_FD_MAX RLIMIT_OPEN_MAX
 409 #else
 410 #undef RLIMIT_FD_MAX
 411 #endif
 412 #endif
 413 #endif
 414
 415 /** Set file descriptor limit for the process.
 416  * @param[in] max_descriptors Ideal number of file descriptors.
 417  * @return Zero on success; -1 on error; positive number of possible
 418  * file descriptors if \a max_descriptors is too high.
 419  */
 420 int os_set_fdlimit(unsigned int max_descriptors)
 421 {
 422 #if defined(HAVE_SETRLIMIT) && defined(RLIMIT_FD_MAX)
 423   struct rlimit limit;
 424
 425   if (!getrlimit(RLIMIT_FD_MAX, &limit)) {
 426     if (limit.rlim_max < max_descriptors)
 427       return limit.rlim_max;
 428     limit.rlim_cur = limit.rlim_max;    /* make soft limit the max */
 429     return setrlimit(RLIMIT_FD_MAX, &limit);
 430   }
 431 #endif /* defined(HAVE_SETRLIMIT) && defined(RLIMIT_FD_MAX) */
 432   return 0;
 433 }
 434
 435 /** Attempt to read from a non-blocking socket.
 436  * @param[in] fd File descriptor to read from.
 437  * @param[out] buf Output buffer to read into.
 438  * @param[in] length Number of bytes to read.
 439  * @param[out] count_out Receives number of bytes actually read.
 440  * @return An IOResult value indicating status.
 441  */
 442 IOResult os_recv_nonb(int fd, char* buf, unsigned int length,
 443                  unsigned int* count_out)
 444 {
 445   int res;
 446   assert(0 != buf);
 447   assert(0 != count_out);
 448
 449   if (0 < (res = recv(fd, buf, length, 0))) {
 450     *count_out = (unsigned) res;
 451     return IO_SUCCESS;
 452   } else if (res == 0) {
 453     *count_out = 0;
 454     errno = 0; /* or ECONNRESET? */
 455     return IO_FAILURE;
 456   } else {
 457     *count_out = 0;
 458     return is_blocked(errno) ? IO_BLOCKED : IO_FAILURE;
 459   }
 460 }
 461
 462 /** Attempt to read from a non-blocking UDP socket.
 463  * @param[in] fd File descriptor to read from.
 464  * @param[out] buf Output buffer to read into.
 465  * @param[in] length Number of bytes to read.
 466  * @param[out] length_out Receives number of bytes actually read.
 467  * @param[out] addr_out Peer address that sent the message.
 468  * @return An IOResult value indicating status.
 469  */
 470 IOResult os_recvfrom_nonb(int fd, char* buf, unsigned int length,
 471                           unsigned int* length_out,
 472                           struct irc_sockaddr* addr_out)
 473 {
 474   struct sockaddr_native addr;
 475   unsigned int len = sizeof(addr);
 476   int    res;
 477   assert(0 != buf);
 478   assert(0 != length_out);
 479   assert(0 != addr_out);
 480
 481   res = recvfrom(fd, buf, length, 0, (struct sockaddr*) &addr, &len);
 482   if (-1 < res) {
 483     sockaddr_to_irc(&addr, addr_out);
 484     *length_out = res;
 485     return IO_SUCCESS;
 486   } else {
 487     *length_out = 0;
 488     return is_blocked(errno) ? IO_BLOCKED : IO_FAILURE;
 489   }
 490 }
 491
 492 /** Attempt to write on a non-blocking UDP socket.
 493  * @param[in] fd File descriptor to write to.
 494  * @param[in] buf Output buffer to send from.
 495  * @param[in] length Number of bytes to write.
 496  * @param[out] count_out Receives number of bytes actually written.
 497  * @param[in] flags Flags for call to sendto().
 498  * @param[in] peer Destination address of the message.
 499  * @return An IOResult value indicating status.
 500  */
 501 IOResult os_sendto_nonb(int fd, const char* buf, unsigned int length,
 502                         unsigned int* count_out, unsigned int flags,
 503                         const struct irc_sockaddr* peer)
 504 {
 505   struct sockaddr_native addr;
 506   int res, size;
 507   assert(0 != buf);
 508
 509   size = sockaddr_from_irc(&addr, peer, fd, 0);
 510   assert((addr.sn_family == AF_INET) == irc_in_addr_is_ipv4(&peer->addr));
 511   if (-1 < (res = sendto(fd, buf, length, flags, (struct sockaddr*)&addr, size))) {
 512     if (count_out)
 513       *count_out = (unsigned) res;
 514     return IO_SUCCESS;
 515   } else {
 516     if (count_out)
 517       *count_out = 0;
 518     return is_blocked(errno) ? IO_BLOCKED : IO_FAILURE;
 519   }
 520 }
 521
 522 /** Attempt to write on a connected socket.
 523  * @param[in] fd File descriptor to write to.
 524  * @param[in] buf Output buffer to send from.
 525  * @param[in] length Number of bytes to write.
 526  * @param[out] count_out Receives number of bytes actually written.
 527  * @return An IOResult value indicating status.
 528  */
 529 IOResult os_send_nonb(int fd, const char* buf, unsigned int length,
 530                  unsigned int* count_out)
 531 {
 532   int res;
 533   assert(0 != buf);
 534   assert(0 != count_out);
 535
 536   if (-1 < (res = send(fd, buf, length, 0))) {
 537     *count_out = (unsigned) res;
 538     return IO_SUCCESS;
 539   } else {
 540     *count_out = 0;
 541     return is_blocked(errno) ? IO_BLOCKED : IO_FAILURE;
 542   }
 543 }
 544
 545 /** Attempt a vectored write on a connected socket.
 546  * @param[in] fd File descriptor to write to.
 547  * @param[in] buf Message queue to send from.
 548  * @param[out] count_in Number of bytes mapped from \a buf.
 549  * @param[out] count_out Receives number of bytes actually written.
 550  * @return An IOResult value indicating status.
 551  */
 552 IOResult os_sendv_nonb(int fd, struct MsgQ* buf, unsigned int* count_in,
 553                        unsigned int* count_out)
 554 {
 555   int res;
 556   int count;
 557   struct iovec iov[IOV_MAX];
 558
 559   assert(0 != buf);
 560   assert(0 != count_in);
 561   assert(0 != count_out);
 562
 563   *count_in = 0;
 564   count = msgq_mapiov(buf, iov, IOV_MAX, count_in);
 565
 566   if (-1 < (res = writev(fd, iov, count))) {
 567     *count_out = (unsigned) res;
 568     return IO_SUCCESS;
 569   } else {
 570     *count_out = 0;
 571     return is_blocked(errno) ? IO_BLOCKED : IO_FAILURE;
 572   }
 573 }
 574
 575 /** Open a TCP or UDP socket on a particular address.
 576  * @param[in] local Local address to bind to.
 577  * @param[in] type SOCK_STREAM or SOCK_DGRAM.
 578  * @param[in] port_name Port name (used in error diagnostics).
 579  * @param[in] family A specific address family to use, or 0 for automatic.
 580  * @return Bound descriptor, or -1 on error.
 581  */
 582 int os_socket(const struct irc_sockaddr* local, int type, const char* port_name, int family)
 583 {
 584   struct sockaddr_native addr;
 585   int size, fd;
 586
 587   assert(local != 0);
 588   size = sockaddr_from_irc(&addr, local, -1, family);
 589   fd = socket(addr.sn_family, type, 0);
 590   if (fd < 0) {
 591     report_error(SOCKET_ERROR_MSG, port_name, errno);
 592     return -1;
 593   }
 594   if (fd > MAXCLIENTS - 1) {
 595     report_error(CONNLIMIT_ERROR_MSG, port_name, 0);
 596     close(fd);
 597     return -1;
 598   }
 599   if (!os_set_reuseaddr(fd)) {
 600     report_error(REUSEADDR_ERROR_MSG, port_name, errno);
 601     close(fd);
 602     return -1;
 603   }
 604   if (!os_set_nonblocking(fd)) {
 605     report_error(NONB_ERROR_MSG, port_name, errno);
 606     close(fd);
 607     return -1;
 608   }
 609   if (local) {
 610 #if defined(IPV6_V6ONLY)
 611     int on = 1;
 612     if (family == AF_INET6 && irc_in_addr_unspec(&local->addr))
 613       setsockopt(fd, IPPROTO_IPV6, IPV6_V6ONLY, &on, sizeof(on));
 614 #endif
 615     if (bind(fd, (struct sockaddr*)&addr, size)) {
 616       report_error(BIND_ERROR_MSG, port_name, errno);
 617       close(fd);
 618       return -1;
 619     }
 620   }
 621   return fd;
 622 }
 623
 624 /** Accept a connection on a socket.
 625  * @param[in] fd Listening file descriptor.
 626  * @param[out] peer Peer address of connection.
 627  * @return File descriptor for accepted connection.
 628  */
 629 int os_accept(int fd, struct irc_sockaddr* peer)
 630 {
 631   struct sockaddr_native addr;
 632   socklen_t addrlen;
 633   int new_fd;
 634
 635   addrlen = sizeof(addr);
 636   new_fd = accept(fd, (struct sockaddr*)&addr, &addrlen);
 637   if (new_fd < 0)
 638     memset(peer, 0, sizeof(*peer));
 639   else
 640     sockaddr_to_irc(&addr, peer);
 641   return new_fd;
 642 }
 643
 644 /** Start a non-blocking connection.
 645  * @param[in] fd Disconnected file descriptor.
 646  * @param[in] sin Target address for connection.
 647  * @return IOResult code indicating status.
 648  */
 649 IOResult os_connect_nonb(int fd, const struct irc_sockaddr* sin)
 650 {
 651   struct sockaddr_native addr;
 652   int size;
 653
 654   size = sockaddr_from_irc(&addr, sin, fd, 0);
 655   if (0 == connect(fd, (struct sockaddr*) &addr, size))
 656     return IO_SUCCESS;
 657   else if (errno == EINPROGRESS)
 658     return IO_BLOCKED;
 659   else
 660     return IO_FAILURE;
 661 }
 662
 663 /** Get local address of a socket.
 664  * @param[in] fd File descriptor to operate on.
 665  * @param[out] sin_out Receives local socket address.
 666  * @return Non-zero on success; zero on error.
 667  */
 668 int os_get_sockname(int fd, struct irc_sockaddr* sin_out)
 669 {
 670   struct sockaddr_native addr;
 671   unsigned int len = sizeof(addr);
 672
 673   assert(0 != sin_out);
 674   if (getsockname(fd, (struct sockaddr*) &addr, &len))
 675     return 0;
 676   sockaddr_to_irc(&addr, sin_out);
 677   return 1;
 678 }
 679
 680 /** Get remote address of a socket.
 681  * @param[in] fd File descriptor to operate on.
 682  * @param[out] sin_out Receives remote socket address.
 683  * @return Non-zero on success; zero on error.
 684  */
 685 int os_get_peername(int fd, struct irc_sockaddr* sin_out)
 686 {
 687   struct sockaddr_native addr;
 688   unsigned int len = sizeof(addr);
 689
 690   assert(0 != sin_out);
 691   if (getpeername(fd, (struct sockaddr*) &addr, &len))
 692     return 0;
 693   sockaddr_to_irc(&addr, sin_out);
 694   return 1;
 695 }
 696
 697 /** Start listening on a socket.
 698  * @param[in] fd Disconnected file descriptor.
 699  * @param[in] backlog Maximum number of un-accept()ed connections to keep.
 700  * @return Non-zero on success; zero on error.
 701  */
 702 int os_set_listen(int fd, int backlog)
 703 {
 704   return (0 == listen(fd, backlog));
 705 }
 706
 707 /** Allocate a connected pair of local sockets.
 708  * @param[out] sv Array of two file descriptors.
 709  * @return Zero on success; non-zero number on error.
 710  */
 711 int os_socketpair(int sv[2])
 712 {
 713     return socketpair(AF_UNIX, SOCK_STREAM, 0, sv);
 714 }