| 1 | /* -*- c-file-style: "linux" -*- |
| 2 | |
| 3 | Copyright (C) 1998-2001 by Andrew Tridgell |
| 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 2 of the License, or |
| 8 | (at your option) 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 | |
| 20 | /* |
| 21 | socket functions used in rsync |
| 22 | |
| 23 | */ |
| 24 | |
| 25 | #include "rsync.h" |
| 26 | |
| 27 | |
| 28 | /* Establish a proxy connection on an open socket to a web roxy by |
| 29 | * using the CONNECT method. */ |
| 30 | static int establish_proxy_connection(int fd, char *host, int port) |
| 31 | { |
| 32 | char buffer[1024]; |
| 33 | char *cp; |
| 34 | |
| 35 | slprintf(buffer, sizeof(buffer), "CONNECT %s:%d HTTP/1.0\r\n\r\n", host, port); |
| 36 | if (write(fd, buffer, strlen(buffer)) != strlen(buffer)) { |
| 37 | rprintf(FERROR, "failed to write to proxy: %s\n", |
| 38 | strerror(errno)); |
| 39 | return -1; |
| 40 | } |
| 41 | |
| 42 | for (cp = buffer; cp < &buffer[sizeof(buffer) - 1]; cp++) { |
| 43 | if (read(fd, cp, 1) != 1) { |
| 44 | rprintf(FERROR, "failed to read from proxy: %s\n", |
| 45 | strerror(errno)); |
| 46 | return -1; |
| 47 | } |
| 48 | if (*cp == '\n') |
| 49 | break; |
| 50 | } |
| 51 | |
| 52 | if (*cp != '\n') |
| 53 | cp++; |
| 54 | *cp-- = '\0'; |
| 55 | if (*cp == '\r') |
| 56 | *cp = '\0'; |
| 57 | if (strncmp(buffer, "HTTP/", 5) != 0) { |
| 58 | rprintf(FERROR, "bad response from proxy - %s\n", |
| 59 | buffer); |
| 60 | return -1; |
| 61 | } |
| 62 | for (cp = &buffer[5]; isdigit(*cp) || (*cp == '.'); cp++) |
| 63 | ; |
| 64 | while (*cp == ' ') |
| 65 | cp++; |
| 66 | if (*cp != '2') { |
| 67 | rprintf(FERROR, "bad response from proxy - %s\n", |
| 68 | buffer); |
| 69 | return -1; |
| 70 | } |
| 71 | /* throw away the rest of the HTTP header */ |
| 72 | while (1) { |
| 73 | for (cp = buffer; cp < &buffer[sizeof(buffer) - 1]; |
| 74 | cp++) { |
| 75 | if (read(fd, cp, 1) != 1) { |
| 76 | rprintf(FERROR, "failed to read from proxy: %s\n", |
| 77 | strerror(errno)); |
| 78 | return -1; |
| 79 | } |
| 80 | if (*cp == '\n') |
| 81 | break; |
| 82 | } |
| 83 | if ((cp > buffer) && (*cp == '\n')) |
| 84 | cp--; |
| 85 | if ((cp == buffer) && ((*cp == '\n') || (*cp == '\r'))) |
| 86 | break; |
| 87 | } |
| 88 | return 0; |
| 89 | } |
| 90 | |
| 91 | |
| 92 | /* open a socket to a tcp remote host with the specified port |
| 93 | based on code from Warren |
| 94 | proxy support by Stephen Rothwell */ |
| 95 | int open_socket_out(char *host, int port, struct in_addr *address) |
| 96 | { |
| 97 | int type = SOCK_STREAM; |
| 98 | struct sockaddr_in sock_out; |
| 99 | struct sockaddr_in sock; |
| 100 | int res; |
| 101 | struct hostent *hp; |
| 102 | char *h; |
| 103 | unsigned p; |
| 104 | int proxied = 0; |
| 105 | char buffer[1024]; |
| 106 | char *cp; |
| 107 | |
| 108 | /* if we have a RSYNC_PROXY env variable then redirect our |
| 109 | * connetcion via a web proxy at the given address. The format |
| 110 | * is hostname:port */ |
| 111 | h = getenv("RSYNC_PROXY"); |
| 112 | proxied = (h != NULL) && (*h != '\0'); |
| 113 | |
| 114 | if (proxied) { |
| 115 | strlcpy(buffer, h, sizeof(buffer)); |
| 116 | cp = strchr(buffer, ':'); |
| 117 | if (cp == NULL) { |
| 118 | rprintf(FERROR, |
| 119 | "invalid proxy specification: should be HOST:PORT\n"); |
| 120 | return -1; |
| 121 | } |
| 122 | *cp++ = '\0'; |
| 123 | p = atoi(cp); |
| 124 | h = buffer; |
| 125 | } else { |
| 126 | h = host; |
| 127 | p = port; |
| 128 | } |
| 129 | |
| 130 | res = socket(PF_INET, type, 0); |
| 131 | if (res == -1) { |
| 132 | return -1; |
| 133 | } |
| 134 | |
| 135 | hp = gethostbyname(h); |
| 136 | if (!hp) { |
| 137 | rprintf(FERROR,"unknown host: %s\n", h); |
| 138 | close(res); |
| 139 | return -1; |
| 140 | } |
| 141 | |
| 142 | memcpy(&sock_out.sin_addr, hp->h_addr, hp->h_length); |
| 143 | sock_out.sin_port = htons(p); |
| 144 | sock_out.sin_family = PF_INET; |
| 145 | |
| 146 | if (address) { |
| 147 | sock.sin_addr = *address; |
| 148 | sock.sin_port = 0; |
| 149 | sock.sin_family = hp->h_addrtype; |
| 150 | bind(res, (struct sockaddr * ) &sock,sizeof(sock)); |
| 151 | } |
| 152 | |
| 153 | if (connect(res,(struct sockaddr *)&sock_out,sizeof(sock_out))) { |
| 154 | rprintf(FERROR,"failed to connect to %s - %s\n", h, strerror(errno)); |
| 155 | close(res); |
| 156 | return -1; |
| 157 | } |
| 158 | |
| 159 | if (proxied && establish_proxy_connection(res, host, port) != 0) { |
| 160 | close(res); |
| 161 | return -1; |
| 162 | } |
| 163 | |
| 164 | return res; |
| 165 | } |
| 166 | |
| 167 | |
| 168 | /**************************************************************************** |
| 169 | open a socket of the specified type, port and address for incoming data |
| 170 | ****************************************************************************/ |
| 171 | static int open_socket_in(int type, int port, struct in_addr *address) |
| 172 | { |
| 173 | struct hostent *hp; |
| 174 | struct sockaddr_in sock; |
| 175 | char host_name[MAXHOSTNAMELEN]; |
| 176 | int res; |
| 177 | int one=1; |
| 178 | |
| 179 | /* get my host name */ |
| 180 | if (gethostname(host_name, sizeof(host_name)) == -1) { |
| 181 | rprintf(FERROR,"gethostname failed\n"); |
| 182 | return -1; |
| 183 | } |
| 184 | |
| 185 | /* get host info */ |
| 186 | if ((hp = gethostbyname(host_name)) == 0) { |
| 187 | rprintf(FERROR,"gethostbyname: Unknown host %s\n",host_name); |
| 188 | return -1; |
| 189 | } |
| 190 | |
| 191 | memset((char *)&sock,0,sizeof(sock)); |
| 192 | memcpy((char *)&sock.sin_addr,(char *)hp->h_addr, hp->h_length); |
| 193 | sock.sin_port = htons(port); |
| 194 | sock.sin_family = hp->h_addrtype; |
| 195 | if (address) { |
| 196 | sock.sin_addr = *address; |
| 197 | } else { |
| 198 | sock.sin_addr.s_addr = INADDR_ANY; |
| 199 | } |
| 200 | res = socket(hp->h_addrtype, type, 0); |
| 201 | if (res == -1) { |
| 202 | rprintf(FERROR,"socket failed: %s\n", |
| 203 | strerror(errno)); |
| 204 | return -1; |
| 205 | } |
| 206 | |
| 207 | setsockopt(res,SOL_SOCKET,SO_REUSEADDR,(char *)&one,sizeof(one)); |
| 208 | |
| 209 | /* now we've got a socket - we need to bind it */ |
| 210 | if (bind(res, (struct sockaddr * ) &sock,sizeof(sock)) == -1) { |
| 211 | rprintf(FERROR,"bind failed on port %d: %s\n", port, |
| 212 | strerror(errno)); |
| 213 | close(res); |
| 214 | return -1; |
| 215 | } |
| 216 | |
| 217 | return res; |
| 218 | } |
| 219 | |
| 220 | |
| 221 | /* |
| 222 | * Determine if a file descriptor is in fact a socket |
| 223 | */ |
| 224 | int is_a_socket(int fd) |
| 225 | { |
| 226 | int v, l; |
| 227 | l = sizeof(int); |
| 228 | |
| 229 | /* Parameters to getsockopt, setsockopt etc are very |
| 230 | * unstandardized across platforms, so don't be surprised if |
| 231 | * there are compiler warnings on e.g. SCO OpenSwerver. It |
| 232 | * seems they all eventually get the right idea. |
| 233 | * |
| 234 | * Debian says: ``The fifth argument of getsockopt and |
| 235 | * setsockopt is in reality an int [*] (and this is what BSD |
| 236 | * 4.* and libc4 and libc5 have). Some POSIX confusion |
| 237 | * resulted in the present socklen_t. The draft standard has |
| 238 | * not been adopted yet, but glibc2 already follows it and |
| 239 | * also has socklen_t [*]. See also accept(2).'' |
| 240 | * |
| 241 | * We now return to your regularly scheduled programming. */ |
| 242 | return(getsockopt(fd, SOL_SOCKET, SO_TYPE, (char *)&v, &l) == 0); |
| 243 | } |
| 244 | |
| 245 | |
| 246 | void start_accept_loop(int port, int (*fn)(int )) |
| 247 | { |
| 248 | int s; |
| 249 | extern struct in_addr socket_address; |
| 250 | |
| 251 | /* open an incoming socket */ |
| 252 | s = open_socket_in(SOCK_STREAM, port, &socket_address); |
| 253 | if (s == -1) |
| 254 | exit_cleanup(RERR_SOCKETIO); |
| 255 | |
| 256 | /* ready to listen */ |
| 257 | if (listen(s, 5) == -1) { |
| 258 | close(s); |
| 259 | exit_cleanup(RERR_SOCKETIO); |
| 260 | } |
| 261 | |
| 262 | |
| 263 | /* now accept incoming connections - forking a new process |
| 264 | for each incoming connection */ |
| 265 | while (1) { |
| 266 | fd_set fds; |
| 267 | int fd; |
| 268 | struct sockaddr addr; |
| 269 | int in_addrlen = sizeof(addr); |
| 270 | |
| 271 | /* close log file before the potentially very long select so |
| 272 | file can be trimmed by another process instead of growing |
| 273 | forever */ |
| 274 | log_close(); |
| 275 | |
| 276 | FD_ZERO(&fds); |
| 277 | FD_SET(s, &fds); |
| 278 | |
| 279 | if (select(s+1, &fds, NULL, NULL, NULL) != 1) { |
| 280 | continue; |
| 281 | } |
| 282 | |
| 283 | if(!FD_ISSET(s, &fds)) continue; |
| 284 | |
| 285 | /* See note above prototypes. */ |
| 286 | fd = accept(s,&addr,&in_addrlen); |
| 287 | |
| 288 | if (fd == -1) continue; |
| 289 | |
| 290 | signal(SIGCHLD, SIG_IGN); |
| 291 | |
| 292 | /* we shouldn't have any children left hanging around |
| 293 | but I have had reports that on Digital Unix zombies |
| 294 | are produced, so this ensures that they are reaped */ |
| 295 | #ifdef WNOHANG |
| 296 | while (waitpid(-1, NULL, WNOHANG) > 0); |
| 297 | #endif |
| 298 | |
| 299 | if (fork()==0) { |
| 300 | close(s); |
| 301 | |
| 302 | /* open log file in child before possibly giving |
| 303 | up privileges */ |
| 304 | log_open(); |
| 305 | |
| 306 | _exit(fn(fd)); |
| 307 | } |
| 308 | |
| 309 | close(fd); |
| 310 | } |
| 311 | } |
| 312 | |
| 313 | |
| 314 | enum SOCK_OPT_TYPES {OPT_BOOL,OPT_INT,OPT_ON}; |
| 315 | |
| 316 | struct |
| 317 | { |
| 318 | char *name; |
| 319 | int level; |
| 320 | int option; |
| 321 | int value; |
| 322 | int opttype; |
| 323 | } socket_options[] = { |
| 324 | {"SO_KEEPALIVE", SOL_SOCKET, SO_KEEPALIVE, 0, OPT_BOOL}, |
| 325 | {"SO_REUSEADDR", SOL_SOCKET, SO_REUSEADDR, 0, OPT_BOOL}, |
| 326 | {"SO_BROADCAST", SOL_SOCKET, SO_BROADCAST, 0, OPT_BOOL}, |
| 327 | #ifdef TCP_NODELAY |
| 328 | {"TCP_NODELAY", IPPROTO_TCP, TCP_NODELAY, 0, OPT_BOOL}, |
| 329 | #endif |
| 330 | #ifdef IPTOS_LOWDELAY |
| 331 | {"IPTOS_LOWDELAY", IPPROTO_IP, IP_TOS, IPTOS_LOWDELAY, OPT_ON}, |
| 332 | #endif |
| 333 | #ifdef IPTOS_THROUGHPUT |
| 334 | {"IPTOS_THROUGHPUT", IPPROTO_IP, IP_TOS, IPTOS_THROUGHPUT, OPT_ON}, |
| 335 | #endif |
| 336 | #ifdef SO_SNDBUF |
| 337 | {"SO_SNDBUF", SOL_SOCKET, SO_SNDBUF, 0, OPT_INT}, |
| 338 | #endif |
| 339 | #ifdef SO_RCVBUF |
| 340 | {"SO_RCVBUF", SOL_SOCKET, SO_RCVBUF, 0, OPT_INT}, |
| 341 | #endif |
| 342 | #ifdef SO_SNDLOWAT |
| 343 | {"SO_SNDLOWAT", SOL_SOCKET, SO_SNDLOWAT, 0, OPT_INT}, |
| 344 | #endif |
| 345 | #ifdef SO_RCVLOWAT |
| 346 | {"SO_RCVLOWAT", SOL_SOCKET, SO_RCVLOWAT, 0, OPT_INT}, |
| 347 | #endif |
| 348 | #ifdef SO_SNDTIMEO |
| 349 | {"SO_SNDTIMEO", SOL_SOCKET, SO_SNDTIMEO, 0, OPT_INT}, |
| 350 | #endif |
| 351 | #ifdef SO_RCVTIMEO |
| 352 | {"SO_RCVTIMEO", SOL_SOCKET, SO_RCVTIMEO, 0, OPT_INT}, |
| 353 | #endif |
| 354 | {NULL,0,0,0,0}}; |
| 355 | |
| 356 | |
| 357 | |
| 358 | /**************************************************************************** |
| 359 | set user socket options |
| 360 | ****************************************************************************/ |
| 361 | void set_socket_options(int fd, char *options) |
| 362 | { |
| 363 | char *tok; |
| 364 | if (!options || !*options) return; |
| 365 | |
| 366 | options = strdup(options); |
| 367 | |
| 368 | if (!options) out_of_memory("set_socket_options"); |
| 369 | |
| 370 | for (tok=strtok(options, " \t,"); tok; tok=strtok(NULL," \t,")) { |
| 371 | int ret=0,i; |
| 372 | int value = 1; |
| 373 | char *p; |
| 374 | int got_value = 0; |
| 375 | |
| 376 | if ((p = strchr(tok,'='))) { |
| 377 | *p = 0; |
| 378 | value = atoi(p+1); |
| 379 | got_value = 1; |
| 380 | } |
| 381 | |
| 382 | for (i=0;socket_options[i].name;i++) |
| 383 | if (strcmp(socket_options[i].name,tok)==0) |
| 384 | break; |
| 385 | |
| 386 | if (!socket_options[i].name) { |
| 387 | rprintf(FERROR,"Unknown socket option %s\n",tok); |
| 388 | continue; |
| 389 | } |
| 390 | |
| 391 | switch (socket_options[i].opttype) { |
| 392 | case OPT_BOOL: |
| 393 | case OPT_INT: |
| 394 | ret = setsockopt(fd,socket_options[i].level, |
| 395 | socket_options[i].option,(char *)&value,sizeof(int)); |
| 396 | break; |
| 397 | |
| 398 | case OPT_ON: |
| 399 | if (got_value) |
| 400 | rprintf(FERROR,"syntax error - %s does not take a value\n",tok); |
| 401 | |
| 402 | { |
| 403 | int on = socket_options[i].value; |
| 404 | ret = setsockopt(fd,socket_options[i].level, |
| 405 | socket_options[i].option,(char *)&on,sizeof(int)); |
| 406 | } |
| 407 | break; |
| 408 | } |
| 409 | |
| 410 | if (ret != 0) |
| 411 | rprintf(FERROR, "failed to set socket option %s: %s\n", tok, |
| 412 | strerror(errno)); |
| 413 | } |
| 414 | |
| 415 | free(options); |
| 416 | } |
| 417 | |
| 418 | /**************************************************************************** |
| 419 | become a daemon, discarding the controlling terminal |
| 420 | ****************************************************************************/ |
| 421 | void become_daemon(void) |
| 422 | { |
| 423 | int i; |
| 424 | |
| 425 | if (fork()) { |
| 426 | _exit(0); |
| 427 | } |
| 428 | |
| 429 | /* detach from the terminal */ |
| 430 | #ifdef HAVE_SETSID |
| 431 | setsid(); |
| 432 | #else |
| 433 | #ifdef TIOCNOTTY |
| 434 | i = open("/dev/tty", O_RDWR); |
| 435 | if (i >= 0) { |
| 436 | ioctl(i, (int) TIOCNOTTY, (char *)0); |
| 437 | close(i); |
| 438 | } |
| 439 | #endif /* TIOCNOTTY */ |
| 440 | #endif |
| 441 | /* make sure that stdin, stdout an stderr don't stuff things |
| 442 | up (library functions, for example) */ |
| 443 | for (i=0;i<3;i++) { |
| 444 | close(i); |
| 445 | open("/dev/null", O_RDWR); |
| 446 | } |
| 447 | } |
| 448 | |
| 449 | /******************************************************************* |
| 450 | return the IP addr of the client as a string |
| 451 | ******************************************************************/ |
| 452 | char *client_addr(int fd) |
| 453 | { |
| 454 | struct sockaddr sa; |
| 455 | struct sockaddr_in *sockin = (struct sockaddr_in *) (&sa); |
| 456 | int length = sizeof(sa); |
| 457 | static char addr_buf[100]; |
| 458 | static int initialised; |
| 459 | |
| 460 | if (initialised) return addr_buf; |
| 461 | |
| 462 | initialised = 1; |
| 463 | |
| 464 | if (getpeername(fd, &sa, &length)) { |
| 465 | exit_cleanup(RERR_SOCKETIO); |
| 466 | } |
| 467 | |
| 468 | strlcpy(addr_buf,(char *)inet_ntoa(sockin->sin_addr), sizeof(addr_buf)); |
| 469 | return addr_buf; |
| 470 | } |
| 471 | |
| 472 | |
| 473 | /******************************************************************* |
| 474 | return the DNS name of the client |
| 475 | ******************************************************************/ |
| 476 | char *client_name(int fd) |
| 477 | { |
| 478 | struct sockaddr sa; |
| 479 | struct sockaddr_in *sockin = (struct sockaddr_in *) (&sa); |
| 480 | int length = sizeof(sa); |
| 481 | static char name_buf[100]; |
| 482 | struct hostent *hp; |
| 483 | char **p; |
| 484 | char *def = "UNKNOWN"; |
| 485 | static int initialised; |
| 486 | |
| 487 | if (initialised) return name_buf; |
| 488 | |
| 489 | initialised = 1; |
| 490 | |
| 491 | strcpy(name_buf,def); |
| 492 | |
| 493 | if (getpeername(fd, &sa, &length)) { |
| 494 | exit_cleanup(RERR_SOCKETIO); |
| 495 | } |
| 496 | |
| 497 | /* Look up the remote host name. */ |
| 498 | if ((hp = gethostbyaddr((char *) &sockin->sin_addr, |
| 499 | sizeof(sockin->sin_addr), |
| 500 | AF_INET))) { |
| 501 | strlcpy(name_buf,(char *)hp->h_name,sizeof(name_buf)); |
| 502 | } |
| 503 | |
| 504 | |
| 505 | /* do a forward lookup as well to prevent spoofing */ |
| 506 | hp = gethostbyname(name_buf); |
| 507 | if (!hp) { |
| 508 | strcpy(name_buf,def); |
| 509 | rprintf(FERROR,"reverse name lookup failed\n"); |
| 510 | } else { |
| 511 | for (p=hp->h_addr_list;*p;p++) { |
| 512 | if (memcmp(*p, &sockin->sin_addr, hp->h_length) == 0) { |
| 513 | break; |
| 514 | } |
| 515 | } |
| 516 | if (!*p) { |
| 517 | strcpy(name_buf,def); |
| 518 | rprintf(FERROR,"reverse name lookup mismatch - spoofed address?\n"); |
| 519 | } |
| 520 | } |
| 521 | |
| 522 | return name_buf; |
| 523 | } |
| 524 | |
| 525 | /******************************************************************* |
| 526 | convert a string to an IP address. The string can be a name or |
| 527 | dotted decimal number |
| 528 | ******************************************************************/ |
| 529 | struct in_addr *ip_address(const char *str) |
| 530 | { |
| 531 | static struct in_addr ret; |
| 532 | struct hostent *hp; |
| 533 | |
| 534 | /* try as an IP address */ |
| 535 | if (inet_aton(str, &ret) != 0) { |
| 536 | return &ret; |
| 537 | } |
| 538 | |
| 539 | /* otherwise assume it's a network name of some sort and use |
| 540 | gethostbyname */ |
| 541 | if ((hp = gethostbyname(str)) == 0) { |
| 542 | rprintf(FERROR, "gethostbyname: Unknown host. %s\n",str); |
| 543 | return NULL; |
| 544 | } |
| 545 | |
| 546 | if (hp->h_addr == NULL) { |
| 547 | rprintf(FERROR, "gethostbyname: host address is invalid for host %s\n",str); |
| 548 | return NULL; |
| 549 | } |
| 550 | |
| 551 | if (hp->h_length > sizeof(ret)) { |
| 552 | rprintf(FERROR, "gethostbyname: host address is too large\n"); |
| 553 | return NULL; |
| 554 | } |
| 555 | |
| 556 | memcpy(&ret.s_addr, hp->h_addr, hp->h_length); |
| 557 | |
| 558 | return(&ret); |
| 559 | } |