socket.c

   1 /*
   2  * Socket functions used in rsync.
   3  *
   4  * Copyright (C) 1992-2001 Andrew Tridgell <tridge@samba.org>
   5  * Copyright (C) 2001, 2002 Martin Pool <mbp@samba.org>
   6  * Copyright (C) 2003-2007 Wayne Davison
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License as published by
  10  * the Free Software Foundation; either version 3 of the License, or
  11  * (at your option) any later version.
  12  *
  13  * This program is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  * GNU General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU General Public License along
  19  * with this program; if not, visit the http://fsf.org website.
  20  */
  21
  22 /* This file is now converted to use the new-style getaddrinfo()
  23  * interface, which supports IPv6 but is also supported on recent
  24  * IPv4-only machines.  On systems that don't have that interface, we
  25  * emulate it using the KAME implementation. */
  26
  27 #include "rsync.h"
  28 #include "ifuncs.h"
  29 #include <netinet/in_systm.h>
  30 #include <netinet/ip.h>
  31 #include <netinet/tcp.h>
  32
  33 extern char *bind_address;
  34 extern int default_af_hint;
  35
  36 #ifdef HAVE_SIGACTION
  37 static struct sigaction sigact;
  38 #endif
  39
  40 /**
  41  * Establish a proxy connection on an open socket to a web proxy by
  42  * using the CONNECT method. If proxy_user and proxy_pass are not NULL,
  43  * they are used to authenticate to the proxy using the "Basic"
  44  * proxy-authorization protocol
  45  **/
  46 static int establish_proxy_connection(int fd, char *host, int port,
  47                                       char *proxy_user, char *proxy_pass)
  48 {
  49         char *cp, buffer[1024];
  50         char *authhdr, authbuf[1024];
  51         int len;
  52
  53         if (proxy_user && proxy_pass) {
  54                 stringjoin(buffer, sizeof buffer,
  55                          proxy_user, ":", proxy_pass, NULL);
  56                 len = strlen(buffer);
  57
  58                 if ((len*8 + 5) / 6 >= (int)sizeof authbuf - 3) {
  59                         rprintf(FERROR,
  60                                 "authentication information is too long\n");
  61                         return -1;
  62                 }
  63
  64                 base64_encode(buffer, len, authbuf, 1);
  65                 authhdr = "\r\nProxy-Authorization: Basic ";
  66         } else {
  67                 *authbuf = '\0';
  68                 authhdr = "";
  69         }
  70
  71         snprintf(buffer, sizeof buffer, "CONNECT %s:%d HTTP/1.0%s%s\r\n\r\n",
  72                  host, port, authhdr, authbuf);
  73         len = strlen(buffer);
  74         if (write(fd, buffer, len) != len) {
  75                 rsyserr(FERROR, errno, "failed to write to proxy");
  76                 return -1;
  77         }
  78
  79         for (cp = buffer; cp < &buffer[sizeof buffer - 1]; cp++) {
  80                 if (read(fd, cp, 1) != 1) {
  81                         rsyserr(FERROR, errno, "failed to read from proxy");
  82                         return -1;
  83                 }
  84                 if (*cp == '\n')
  85                         break;
  86         }
  87
  88         if (*cp != '\n')
  89                 cp++;
  90         *cp-- = '\0';
  91         if (*cp == '\r')
  92                 *cp = '\0';
  93         if (strncmp(buffer, "HTTP/", 5) != 0) {
  94                 rprintf(FERROR, "bad response from proxy -- %s\n",
  95                         buffer);
  96                 return -1;
  97         }
  98         for (cp = &buffer[5]; isDigit(cp) || *cp == '.'; cp++) {}
  99         while (*cp == ' ')
 100                 cp++;
 101         if (*cp != '2') {
 102                 rprintf(FERROR, "bad response from proxy -- %s\n",
 103                         buffer);
 104                 return -1;
 105         }
 106         /* throw away the rest of the HTTP header */
 107         while (1) {
 108                 for (cp = buffer; cp < &buffer[sizeof buffer - 1]; cp++) {
 109                         if (read(fd, cp, 1) != 1) {
 110                                 rsyserr(FERROR, errno,
 111                                         "failed to read from proxy");
 112                                 return -1;
 113                         }
 114                         if (*cp == '\n')
 115                                 break;
 116                 }
 117                 if (cp > buffer && *cp == '\n')
 118                         cp--;
 119                 if (cp == buffer && (*cp == '\n' || *cp == '\r'))
 120                         break;
 121         }
 122         return 0;
 123 }
 124
 125
 126 /**
 127  * Try to set the local address for a newly-created socket.  Return -1
 128  * if this fails.
 129  **/
 130 int try_bind_local(int s, int ai_family, int ai_socktype,
 131                    const char *bind_addr)
 132 {
 133         int error;
 134         struct addrinfo bhints, *bres_all, *r;
 135
 136         memset(&bhints, 0, sizeof bhints);
 137         bhints.ai_family = ai_family;
 138         bhints.ai_socktype = ai_socktype;
 139         bhints.ai_flags = AI_PASSIVE;
 140         if ((error = getaddrinfo(bind_addr, NULL, &bhints, &bres_all))) {
 141                 rprintf(FERROR, RSYNC_NAME ": getaddrinfo %s: %s\n",
 142                         bind_addr, gai_strerror(error));
 143                 return -1;
 144         }
 145
 146         for (r = bres_all; r; r = r->ai_next) {
 147                 if (bind(s, r->ai_addr, r->ai_addrlen) == -1)
 148                         continue;
 149                 freeaddrinfo(bres_all);
 150                 return s;
 151         }
 152
 153         /* no error message; there might be some problem that allows
 154          * creation of the socket but not binding, perhaps if the
 155          * machine has no ipv6 address of this name. */
 156         freeaddrinfo(bres_all);
 157         return -1;
 158 }
 159
 160
 161 /**
 162  * Open a socket to a tcp remote host with the specified port .
 163  *
 164  * Based on code from Warren.  Proxy support by Stephen Rothwell.
 165  * getaddrinfo() rewrite contributed by KAME.net.
 166  *
 167  * Now that we support IPv6 we need to look up the remote machine's
 168  * address first, using @p af_hint to set a preference for the type
 169  * of address.  Then depending on whether it has v4 or v6 addresses we
 170  * try to open a connection.
 171  *
 172  * The loop allows for machines with some addresses which may not be
 173  * reachable, perhaps because we can't e.g. route ipv6 to that network
 174  * but we can get ip4 packets through.
 175  *
 176  * @param bind_addr Local address to use.  Normally NULL to bind
 177  * the wildcard address.
 178  *
 179  * @param af_hint Address family, e.g. AF_INET or AF_INET6.
 180  **/
 181 int open_socket_out(char *host, int port, const char *bind_addr,
 182                     int af_hint)
 183 {
 184         int type = SOCK_STREAM;
 185         int error, s;
 186         struct addrinfo hints, *res0, *res;
 187         char portbuf[10];
 188         char *h, *cp;
 189         int proxied = 0;
 190         char buffer[1024];
 191         char *proxy_user = NULL, *proxy_pass = NULL;
 192
 193         /* if we have a RSYNC_PROXY env variable then redirect our
 194          * connetcion via a web proxy at the given address. */
 195         h = getenv("RSYNC_PROXY");
 196         proxied = h != NULL && *h != '\0';
 197
 198         if (proxied) {
 199                 strlcpy(buffer, h, sizeof buffer);
 200
 201                 /* Is the USER:PASS@ prefix present? */
 202                 if ((cp = strrchr(buffer, '@')) != NULL) {
 203                         *cp++ = '\0';
 204                         /* The remainder is the HOST:PORT part. */
 205                         h = cp;
 206
 207                         if ((cp = strchr(buffer, ':')) == NULL) {
 208                                 rprintf(FERROR,
 209                                         "invalid proxy specification: should be USER:PASS@HOST:PORT\n");
 210                                 return -1;
 211                         }
 212                         *cp++ = '\0';
 213
 214                         proxy_user = buffer;
 215                         proxy_pass = cp;
 216                 } else {
 217                         /* The whole buffer is the HOST:PORT part. */
 218                         h = buffer;
 219                 }
 220
 221                 if ((cp = strchr(h, ':')) == NULL) {
 222                         rprintf(FERROR,
 223                                 "invalid proxy specification: should be HOST:PORT\n");
 224                         return -1;
 225                 }
 226                 *cp++ = '\0';
 227                 strlcpy(portbuf, cp, sizeof portbuf);
 228                 if (verbose >= 2) {
 229                         rprintf(FINFO, "connection via http proxy %s port %s\n",
 230                                 h, portbuf);
 231                 }
 232         } else {
 233                 snprintf(portbuf, sizeof portbuf, "%d", port);
 234                 h = host;
 235         }
 236
 237         memset(&hints, 0, sizeof hints);
 238         hints.ai_family = af_hint;
 239         hints.ai_socktype = type;
 240         error = getaddrinfo(h, portbuf, &hints, &res0);
 241         if (error) {
 242                 rprintf(FERROR, RSYNC_NAME ": getaddrinfo: %s %s: %s\n",
 243                         h, portbuf, gai_strerror(error));
 244                 return -1;
 245         }
 246
 247         s = -1;
 248         /* Try to connect to all addresses for this machine until we get
 249          * through.  It might e.g. be multi-homed, or have both IPv4 and IPv6
 250          * addresses.  We need to create a socket for each record, since the
 251          * address record tells us what protocol to use to try to connect. */
 252         for (res = res0; res; res = res->ai_next) {
 253                 s = socket(res->ai_family, res->ai_socktype, res->ai_protocol);
 254                 if (s < 0)
 255                         continue;
 256
 257                 if (bind_addr
 258                  && try_bind_local(s, res->ai_family, type,
 259                                    bind_addr) == -1) {
 260                         close(s);
 261                         s = -1;
 262                         continue;
 263                 }
 264                 if (connect(s, res->ai_addr, res->ai_addrlen) < 0) {
 265                         close(s);
 266                         s = -1;
 267                         continue;
 268                 }
 269                 if (proxied
 270                  && establish_proxy_connection(s, host, port,
 271                                                proxy_user, proxy_pass) != 0) {
 272                         close(s);
 273                         s = -1;
 274                         continue;
 275                 }
 276                 break;
 277         }
 278         freeaddrinfo(res0);
 279         if (s < 0) {
 280                 rsyserr(FERROR, errno, "failed to connect to %s", h);
 281                 return -1;
 282         }
 283         return s;
 284 }
 285
 286
 287 /**
 288  * Open an outgoing socket, but allow for it to be intercepted by
 289  * $RSYNC_CONNECT_PROG, which will execute a program across a TCP
 290  * socketpair rather than really opening a socket.
 291  *
 292  * We use this primarily in testing to detect TCP flow bugs, but not
 293  * cause security problems by really opening remote connections.
 294  *
 295  * This is based on the Samba LIBSMB_PROG feature.
 296  *
 297  * @param bind_addr Local address to use.  Normally NULL to get the stack default.
 298  **/
 299 int open_socket_out_wrapped(char *host, int port, const char *bind_addr,
 300                             int af_hint)
 301 {
 302         char *prog = getenv("RSYNC_CONNECT_PROG");
 303
 304         if (prog && strchr(prog, '%')) {
 305                 int hlen = strlen(host);
 306                 int len = strlen(prog) + 1;
 307                 char *f, *t;
 308                 for (f = prog; *f; f++) {
 309                         if (*f != '%')
 310                                 continue;
 311                         /* Compute more than enough room. */
 312                         if (f[1] == '%')
 313                                 f++;
 314                         else
 315                                 len += hlen;
 316                 }
 317                 f = prog;
 318                 if (!(prog = new_array(char, len)))
 319                         out_of_memory("open_socket_out_wrapped");
 320                 for (t = prog; *f; f++) {
 321                         if (*f == '%') {
 322                                 switch (*++f) {
 323                                 case '%':
 324                                         /* Just skips the extra '%'. */
 325                                         break;
 326                                 case 'H':
 327                                         memcpy(t, host, hlen);
 328                                         t += hlen;
 329                                         continue;
 330                                 default:
 331                                         f--; /* pass % through */
 332                                         break;
 333                                 }
 334                         }
 335                         *t++ = *f;
 336                 }
 337                 *t = '\0';
 338         }
 339
 340         if (verbose >= 2) {
 341                 rprintf(FINFO, "%sopening tcp connection to %s port %d\n",
 342                         prog ? "Using RSYNC_CONNECT_PROG instead of " : "",
 343                         host, port);
 344         }
 345         if (prog)
 346                 return sock_exec(prog);
 347         return open_socket_out(host, port, bind_addr, af_hint);
 348 }
 349
 350
 351
 352 /**
 353  * Open one or more sockets for incoming data using the specified type,
 354  * port, and address.
 355  *
 356  * The getaddrinfo() call may return several address results, e.g. for
 357  * the machine's IPv4 and IPv6 name.
 358  *
 359  * We return an array of file-descriptors to the sockets, with a trailing
 360  * -1 value to indicate the end of the list.
 361  *
 362  * @param bind_addr Local address to bind, or NULL to allow it to
 363  * default.
 364  **/
 365 static int *open_socket_in(int type, int port, const char *bind_addr,
 366                            int af_hint)
 367 {
 368         int one = 1;
 369         int s, *socks, maxs, i, ecnt;
 370         struct addrinfo hints, *all_ai, *resp;
 371         char portbuf[10], **errmsgs;
 372         int error;
 373
 374         memset(&hints, 0, sizeof hints);
 375         hints.ai_family = af_hint;
 376         hints.ai_socktype = type;
 377         hints.ai_flags = AI_PASSIVE;
 378         snprintf(portbuf, sizeof portbuf, "%d", port);
 379         error = getaddrinfo(bind_addr, portbuf, &hints, &all_ai);
 380         if (error) {
 381                 rprintf(FERROR, RSYNC_NAME ": getaddrinfo: bind address %s: %s\n",
 382                         bind_addr, gai_strerror(error));
 383                 return NULL;
 384         }
 385
 386         /* Count max number of sockets we might open. */
 387         for (maxs = 0, resp = all_ai; resp; resp = resp->ai_next, maxs++) {}
 388
 389         socks = new_array(int, maxs + 1);
 390         errmsgs = new_array(char *, maxs);
 391         if (!socks || !errmsgs)
 392                 out_of_memory("open_socket_in");
 393
 394         /* We may not be able to create the socket, if for example the
 395          * machine knows about IPv6 in the C library, but not in the
 396          * kernel. */
 397         for (resp = all_ai, i = ecnt = 0; resp; resp = resp->ai_next) {
 398                 s = socket(resp->ai_family, resp->ai_socktype,
 399                            resp->ai_protocol);
 400
 401                 if (s == -1) {
 402                         int r = asprintf(&errmsgs[ecnt++],
 403                                 "socket(%d,%d,%d) failed: %s\n",
 404                                 (int)resp->ai_family, (int)resp->ai_socktype,
 405                                 (int)resp->ai_protocol, strerror(errno));
 406                         if (r < 0)
 407                                 out_of_memory("open_socket_in");
 408                         /* See if there's another address that will work... */
 409                         continue;
 410                 }
 411
 412                 setsockopt(s, SOL_SOCKET, SO_REUSEADDR,
 413                            (char *)&one, sizeof one);
 414
 415 #ifdef IPV6_V6ONLY
 416                 if (resp->ai_family == AF_INET6) {
 417                         if (setsockopt(s, IPPROTO_IPV6, IPV6_V6ONLY,
 418                                        (char *)&one, sizeof one) < 0
 419                             && default_af_hint != AF_INET6) {
 420                                 close(s);
 421                                 continue;
 422                         }
 423                 }
 424 #endif
 425
 426                 /* Now we've got a socket - we need to bind it. */
 427                 if (bind(s, resp->ai_addr, resp->ai_addrlen) < 0) {
 428                         /* Nope, try another */
 429                         int r = asprintf(&errmsgs[ecnt++],
 430                                 "bind() failed: %s (address-family %d)\n",
 431                                 strerror(errno), (int)resp->ai_family);
 432                         if (r < 0)
 433                                 out_of_memory("open_socket_in");
 434                         close(s);
 435                         continue;
 436                 }
 437
 438                 socks[i++] = s;
 439         }
 440         socks[i] = -1;
 441
 442         if (all_ai)
 443                 freeaddrinfo(all_ai);
 444
 445         /* Only output the socket()/bind() messages if we were totally
 446          * unsuccessful, or if the daemon is being run with -vv. */
 447         for (s = 0; s < ecnt; s++) {
 448                 if (!i || verbose > 1)
 449                         rwrite(FLOG, errmsgs[s], strlen(errmsgs[s]), 0);
 450                 free(errmsgs[s]);
 451         }
 452         free(errmsgs);
 453
 454         if (!i) {
 455                 rprintf(FERROR,
 456                         "unable to bind any inbound sockets on port %d\n",
 457                         port);
 458                 free(socks);
 459                 return NULL;
 460         }
 461         return socks;
 462 }
 463
 464
 465 /*
 466  * Determine if a file descriptor is in fact a socket
 467  */
 468 int is_a_socket(int fd)
 469 {
 470         int v;
 471         socklen_t l = sizeof (int);
 472
 473         /* Parameters to getsockopt, setsockopt etc are very
 474          * unstandardized across platforms, so don't be surprised if
 475          * there are compiler warnings on e.g. SCO OpenSwerver or AIX.
 476          * It seems they all eventually get the right idea.
 477          *
 478          * Debian says: ``The fifth argument of getsockopt and
 479          * setsockopt is in reality an int [*] (and this is what BSD
 480          * 4.* and libc4 and libc5 have).  Some POSIX confusion
 481          * resulted in the present socklen_t.  The draft standard has
 482          * not been adopted yet, but glibc2 already follows it and
 483          * also has socklen_t [*]. See also accept(2).''
 484          *
 485          * We now return to your regularly scheduled programming.  */
 486         return getsockopt(fd, SOL_SOCKET, SO_TYPE, (char *)&v, &l) == 0;
 487 }
 488
 489
 490 static RETSIGTYPE sigchld_handler(UNUSED(int val))
 491 {
 492 #ifdef WNOHANG
 493         while (waitpid(-1, NULL, WNOHANG) > 0) {}
 494 #endif
 495 #ifndef HAVE_SIGACTION
 496         signal(SIGCHLD, sigchld_handler);
 497 #endif
 498 }
 499
 500
 501 void start_accept_loop(int port, int (*fn)(int, int))
 502 {
 503         fd_set deffds;
 504         int *sp, maxfd, i;
 505
 506 #ifdef HAVE_SIGACTION
 507         sigact.sa_flags = SA_NOCLDSTOP;
 508 #endif
 509
 510         /* open an incoming socket */
 511         sp = open_socket_in(SOCK_STREAM, port, bind_address, default_af_hint);
 512         if (sp == NULL)
 513                 exit_cleanup(RERR_SOCKETIO);
 514
 515         /* ready to listen */
 516         FD_ZERO(&deffds);
 517         for (i = 0, maxfd = -1; sp[i] >= 0; i++) {
 518                 if (listen(sp[i], 5) < 0) {
 519                         rsyserr(FERROR, errno, "listen() on socket failed");
 520 #ifdef INET6
 521                         if (errno == EADDRINUSE && i > 0) {
 522                                 rprintf(FINFO,
 523                                     "Try using --ipv4 or --ipv6 to avoid this listen() error.\n");
 524                         }
 525 #endif
 526                         exit_cleanup(RERR_SOCKETIO);
 527                 }
 528                 FD_SET(sp[i], &deffds);
 529                 if (maxfd < sp[i])
 530                         maxfd = sp[i];
 531         }
 532
 533         /* now accept incoming connections - forking a new process
 534          * for each incoming connection */
 535         while (1) {
 536                 fd_set fds;
 537                 pid_t pid;
 538                 int fd;
 539                 struct sockaddr_storage addr;
 540                 socklen_t addrlen = sizeof addr;
 541
 542                 /* close log file before the potentially very long select so
 543                  * file can be trimmed by another process instead of growing
 544                  * forever */
 545                 logfile_close();
 546
 547 #ifdef FD_COPY
 548                 FD_COPY(&deffds, &fds);
 549 #else
 550                 fds = deffds;
 551 #endif
 552
 553                 if (select(maxfd + 1, &fds, NULL, NULL, NULL) != 1)
 554                         continue;
 555
 556                 for (i = 0, fd = -1; sp[i] >= 0; i++) {
 557                         if (FD_ISSET(sp[i], &fds)) {
 558                                 fd = accept(sp[i], (struct sockaddr *)&addr,
 559                                             &addrlen);
 560                                 break;
 561                         }
 562                 }
 563
 564                 if (fd < 0)
 565                         continue;
 566
 567                 SIGACTION(SIGCHLD, sigchld_handler);
 568
 569                 if ((pid = fork()) == 0) {
 570                         int ret;
 571                         for (i = 0; sp[i] >= 0; i++)
 572                                 close(sp[i]);
 573                         /* Re-open log file in child before possibly giving
 574                          * up privileges (see logfile_close() above). */
 575                         logfile_reopen();
 576                         ret = fn(fd, fd);
 577                         close_all();
 578                         _exit(ret);
 579                 } else if (pid < 0) {
 580                         rsyserr(FERROR, errno,
 581                                 "could not create child server process");
 582                         close(fd);
 583                         /* This might have happened because we're
 584                          * overloaded.  Sleep briefly before trying to
 585                          * accept again. */
 586                         sleep(2);
 587                 } else {
 588                         /* Parent doesn't need this fd anymore. */
 589                         close(fd);
 590                 }
 591         }
 592 }
 593
 594
 595 enum SOCK_OPT_TYPES {OPT_BOOL,OPT_INT,OPT_ON};
 596
 597 struct
 598 {
 599   char *name;
 600   int level;
 601   int option;
 602   int value;
 603   int opttype;
 604 } socket_options[] = {
 605   {"SO_KEEPALIVE",      SOL_SOCKET,    SO_KEEPALIVE,    0,                 OPT_BOOL},
 606   {"SO_REUSEADDR",      SOL_SOCKET,    SO_REUSEADDR,    0,                 OPT_BOOL},
 607   {"SO_BROADCAST",      SOL_SOCKET,    SO_BROADCAST,    0,                 OPT_BOOL},
 608 #ifdef TCP_NODELAY
 609   {"TCP_NODELAY",       IPPROTO_TCP,   TCP_NODELAY,     0,                 OPT_BOOL},
 610 #endif
 611 #ifdef IPTOS_LOWDELAY
 612   {"IPTOS_LOWDELAY",    IPPROTO_IP,    IP_TOS,          IPTOS_LOWDELAY,    OPT_ON},
 613 #endif
 614 #ifdef IPTOS_THROUGHPUT
 615   {"IPTOS_THROUGHPUT",  IPPROTO_IP,    IP_TOS,          IPTOS_THROUGHPUT,  OPT_ON},
 616 #endif
 617 #ifdef SO_SNDBUF
 618   {"SO_SNDBUF",         SOL_SOCKET,    SO_SNDBUF,       0,                 OPT_INT},
 619 #endif
 620 #ifdef SO_RCVBUF
 621   {"SO_RCVBUF",         SOL_SOCKET,    SO_RCVBUF,       0,                 OPT_INT},
 622 #endif
 623 #ifdef SO_SNDLOWAT
 624   {"SO_SNDLOWAT",       SOL_SOCKET,    SO_SNDLOWAT,     0,                 OPT_INT},
 625 #endif
 626 #ifdef SO_RCVLOWAT
 627   {"SO_RCVLOWAT",       SOL_SOCKET,    SO_RCVLOWAT,     0,                 OPT_INT},
 628 #endif
 629 #ifdef SO_SNDTIMEO
 630   {"SO_SNDTIMEO",       SOL_SOCKET,    SO_SNDTIMEO,     0,                 OPT_INT},
 631 #endif
 632 #ifdef SO_RCVTIMEO
 633   {"SO_RCVTIMEO",       SOL_SOCKET,    SO_RCVTIMEO,     0,                 OPT_INT},
 634 #endif
 635   {NULL,0,0,0,0}};
 636
 637
 638
 639 /**
 640  * Set user socket options
 641  **/
 642 void set_socket_options(int fd, char *options)
 643 {
 644         char *tok;
 645
 646         if (!options || !*options)
 647                 return;
 648
 649         options = strdup(options);
 650
 651         if (!options)
 652                 out_of_memory("set_socket_options");
 653
 654         for (tok = strtok(options, " \t,"); tok; tok = strtok(NULL," \t,")) {
 655                 int ret=0,i;
 656                 int value = 1;
 657                 char *p;
 658                 int got_value = 0;
 659
 660                 if ((p = strchr(tok,'='))) {
 661                         *p = 0;
 662                         value = atoi(p+1);
 663                         got_value = 1;
 664                 }
 665
 666                 for (i = 0; socket_options[i].name; i++) {
 667                         if (strcmp(socket_options[i].name,tok)==0)
 668                                 break;
 669                 }
 670
 671                 if (!socket_options[i].name) {
 672                         rprintf(FERROR,"Unknown socket option %s\n",tok);
 673                         continue;
 674                 }
 675
 676                 switch (socket_options[i].opttype) {
 677                 case OPT_BOOL:
 678                 case OPT_INT:
 679                         ret = setsockopt(fd,socket_options[i].level,
 680                                          socket_options[i].option,
 681                                          (char *)&value, sizeof (int));
 682                         break;
 683
 684                 case OPT_ON:
 685                         if (got_value)
 686                                 rprintf(FERROR,"syntax error -- %s does not take a value\n",tok);
 687
 688                         {
 689                                 int on = socket_options[i].value;
 690                                 ret = setsockopt(fd,socket_options[i].level,
 691                                                  socket_options[i].option,
 692                                                  (char *)&on, sizeof (int));
 693                         }
 694                         break;
 695                 }
 696
 697                 if (ret != 0) {
 698                         rsyserr(FERROR, errno,
 699                                 "failed to set socket option %s", tok);
 700                 }
 701         }
 702
 703         free(options);
 704 }
 705
 706
 707 /**
 708  * This is like socketpair but uses tcp. It is used by the Samba
 709  * regression test code.
 710  *
 711  * The function guarantees that nobody else can attach to the socket,
 712  * or if they do that this function fails and the socket gets closed
 713  * returns 0 on success, -1 on failure the resulting file descriptors
 714  * are symmetrical.
 715  **/
 716 static int socketpair_tcp(int fd[2])
 717 {
 718         int listener;
 719         struct sockaddr_in sock;
 720         struct sockaddr_in sock2;
 721         socklen_t socklen = sizeof sock;
 722         int connect_done = 0;
 723
 724         fd[0] = fd[1] = listener = -1;
 725
 726         memset(&sock, 0, sizeof sock);
 727
 728         if ((listener = socket(PF_INET, SOCK_STREAM, 0)) == -1)
 729                 goto failed;
 730
 731         memset(&sock2, 0, sizeof sock2);
 732 #ifdef HAVE_SOCKADDR_IN_LEN
 733         sock2.sin_len = sizeof sock2;
 734 #endif
 735         sock2.sin_family = PF_INET;
 736
 737         bind(listener, (struct sockaddr *)&sock2, sizeof sock2);
 738
 739         if (listen(listener, 1) != 0)
 740                 goto failed;
 741
 742         if (getsockname(listener, (struct sockaddr *)&sock, &socklen) != 0)
 743                 goto failed;
 744
 745         if ((fd[1] = socket(PF_INET, SOCK_STREAM, 0)) == -1)
 746                 goto failed;
 747
 748         set_nonblocking(fd[1]);
 749
 750         sock.sin_addr.s_addr = htonl(INADDR_LOOPBACK);
 751
 752         if (connect(fd[1], (struct sockaddr *)&sock, sizeof sock) == -1) {
 753                 if (errno != EINPROGRESS)
 754                         goto failed;
 755         } else
 756                 connect_done = 1;
 757
 758         if ((fd[0] = accept(listener, (struct sockaddr *)&sock, &socklen)) == -1)
 759                 goto failed;
 760
 761         close(listener);
 762         listener = -1;
 763
 764         set_blocking(fd[1]);
 765
 766         if (connect_done == 0) {
 767                 if (connect(fd[1], (struct sockaddr *)&sock, sizeof sock) != 0
 768                     && errno != EISCONN)
 769                         goto failed;
 770         }
 771
 772         /* all OK! */
 773         return 0;
 774
 775  failed:
 776         if (fd[0] != -1)
 777                 close(fd[0]);
 778         if (fd[1] != -1)
 779                 close(fd[1]);
 780         if (listener != -1)
 781                 close(listener);
 782         return -1;
 783 }
 784
 785
 786
 787 /**
 788  * Run a program on a local tcp socket, so that we can talk to it's
 789  * stdin and stdout.  This is used to fake a connection to a daemon
 790  * for testing -- not for the normal case of running SSH.
 791  *
 792  * @return a socket which is attached to a subprocess running
 793  * "prog". stdin and stdout are attached. stderr is left attached to
 794  * the original stderr
 795  **/
 796 int sock_exec(const char *prog)
 797 {
 798         int fd[2];
 799
 800         if (socketpair_tcp(fd) != 0) {
 801                 rsyserr(FERROR, errno, "socketpair_tcp failed");
 802                 return -1;
 803         }
 804         if (verbose >= 2)
 805                 rprintf(FINFO, "Running socket program: \"%s\"\n", prog);
 806         if (fork() == 0) {
 807                 close(fd[0]);
 808                 close(0);
 809                 close(1);
 810                 dup(fd[1]);
 811                 dup(fd[1]);
 812                 exit(system(prog));
 813         }
 814         close(fd[1]);
 815         return fd[0];
 816 }