1 /* 2 * Copyright 1995-2025 The OpenSSL Project Authors. All Rights Reserved. 3 * 4 * Licensed under the Apache License 2.0 (the "License"). You may not use 5 * this file except in compliance with the License. You can obtain a copy 6 * in the file LICENSE in the source distribution or at 7 * https://www.openssl.org/source/license.html 8 */ 9 10 /* socket-related functions used by s_client and s_server */ 11 #include <stdio.h> 12 #include <stdlib.h> 13 #include <string.h> 14 #include <errno.h> 15 #include <signal.h> 16 #include <openssl/opensslconf.h> 17 18 /* 19 * With IPv6, it looks like Digital has mixed up the proper order of 20 * recursive header file inclusion, resulting in the compiler complaining 21 * that u_int isn't defined, but only if _POSIX_C_SOURCE is defined, which is 22 * needed to have fileno() declared correctly... So let's define u_int 23 */ 24 #if defined(OPENSSL_SYS_VMS_DECC) && !defined(__U_INT) 25 # define __U_INT 26 typedef unsigned int u_int; 27 #endif 28 29 #ifdef _WIN32 30 # include <process.h> 31 32 /* MSVC renamed some POSIX functions to have an underscore prefix. */ 33 # ifdef _MSC_VER 34 # define getpid _getpid 35 # endif 36 #endif 37 38 #ifndef OPENSSL_NO_SOCK 39 40 # include "internal/e_os.h" 41 # include "apps.h" 42 # include "s_apps.h" 43 # include "internal/sockets.h" /* for openssl_fdset() */ 44 45 # include <openssl/bio.h> 46 # include <openssl/err.h> 47 48 /* Keep track of our peer's address for the cookie callback */ 49 BIO_ADDR *ourpeer = NULL; 50 51 /* 52 * init_client - helper routine to set up socket communication 53 * @sock: pointer to storage of resulting socket. 54 * @host: the hostname or path (for AF_UNIX) to connect to. 55 * @port: the port to connect to (ignored for AF_UNIX). 56 * @bindhost: source host or path (for AF_UNIX). 57 * @bindport: source port (ignored for AF_UNIX). 58 * @family: desired socket family, may be AF_INET, AF_INET6, AF_UNIX or 59 * AF_UNSPEC 60 * @type: socket type, must be SOCK_STREAM or SOCK_DGRAM 61 * @protocol: socket protocol, e.g. IPPROTO_TCP or IPPROTO_UDP (or 0 for any) 62 * @tfo: flag to enable TCP Fast Open 63 * @doconn: whether we should call BIO_connect() on the socket 64 * @ba_ret: BIO_ADDR for the remote peer, to be freed by caller 65 * 66 * This will create a socket and use it to connect to a host:port, or if 67 * family == AF_UNIX, to the path found in host. 68 * 69 * If the host has more than one address, it will try them one by one until 70 * a successful connection is established. The resulting socket will be 71 * found in *sock on success, it will be given INVALID_SOCKET otherwise. 72 * 73 * Returns 1 on success, 0 on failure. 74 */ 75 int init_client(int *sock, const char *host, const char *port, 76 const char *bindhost, const char *bindport, 77 int family, int type, int protocol, int tfo, int doconn, 78 BIO_ADDR **ba_ret) 79 { 80 BIO_ADDRINFO *res = NULL; 81 BIO_ADDRINFO *bindaddr = NULL; 82 const BIO_ADDRINFO *ai = NULL; 83 const BIO_ADDRINFO *bi = NULL; 84 int found = 0; 85 int ret; 86 int options = 0; 87 88 if (BIO_sock_init() != 1) 89 return 0; 90 91 ret = BIO_lookup_ex(host, port, BIO_LOOKUP_CLIENT, family, type, protocol, 92 &res); 93 if (ret == 0) { 94 ERR_print_errors(bio_err); 95 return 0; 96 } 97 98 if (bindhost != NULL || bindport != NULL) { 99 ret = BIO_lookup_ex(bindhost, bindport, BIO_LOOKUP_CLIENT, 100 family, type, protocol, &bindaddr); 101 if (ret == 0) { 102 ERR_print_errors (bio_err); 103 goto out; 104 } 105 } 106 107 ret = 0; 108 for (ai = res; ai != NULL; ai = BIO_ADDRINFO_next(ai)) { 109 /* Admittedly, these checks are quite paranoid, we should not get 110 * anything in the BIO_ADDRINFO chain that we haven't 111 * asked for. */ 112 OPENSSL_assert((family == AF_UNSPEC 113 || family == BIO_ADDRINFO_family(ai)) 114 && (type == 0 || type == BIO_ADDRINFO_socktype(ai)) 115 && (protocol == 0 116 || protocol == BIO_ADDRINFO_protocol(ai))); 117 118 if (bindaddr != NULL) { 119 for (bi = bindaddr; bi != NULL; bi = BIO_ADDRINFO_next(bi)) { 120 if (BIO_ADDRINFO_family(bi) == BIO_ADDRINFO_family(ai)) 121 break; 122 } 123 if (bi == NULL) 124 continue; 125 ++found; 126 } 127 128 *sock = BIO_socket(BIO_ADDRINFO_family(ai), BIO_ADDRINFO_socktype(ai), 129 BIO_ADDRINFO_protocol(ai), 0); 130 if (*sock == INVALID_SOCKET) { 131 /* Maybe the kernel doesn't support the socket family, even if 132 * BIO_lookup() added it in the returned result... 133 */ 134 continue; 135 } 136 137 if (bi != NULL) { 138 if (!BIO_bind(*sock, BIO_ADDRINFO_address(bi), 139 BIO_SOCK_REUSEADDR)) { 140 BIO_closesocket(*sock); 141 *sock = INVALID_SOCKET; 142 break; 143 } 144 } 145 146 #ifndef OPENSSL_NO_SCTP 147 if (protocol == IPPROTO_SCTP) { 148 /* 149 * For SCTP we have to set various options on the socket prior to 150 * connecting. This is done automatically by BIO_new_dgram_sctp(). 151 * We don't actually need the created BIO though so we free it again 152 * immediately. 153 */ 154 BIO *tmpbio = BIO_new_dgram_sctp(*sock, BIO_NOCLOSE); 155 156 if (tmpbio == NULL) { 157 ERR_print_errors(bio_err); 158 return 0; 159 } 160 BIO_free(tmpbio); 161 } 162 #endif 163 if (BIO_ADDRINFO_protocol(ai) == IPPROTO_TCP) { 164 options |= BIO_SOCK_NODELAY; 165 if (tfo) 166 options |= BIO_SOCK_TFO; 167 } 168 169 if (doconn && !BIO_connect(*sock, BIO_ADDRINFO_address(ai), options)) { 170 BIO_closesocket(*sock); 171 *sock = INVALID_SOCKET; 172 continue; 173 } 174 175 /* Save the address */ 176 if (tfo || !doconn) { 177 if (ba_ret == NULL) { 178 BIO_printf(bio_err, "Internal error\n"); 179 BIO_closesocket(*sock); 180 *sock = INVALID_SOCKET; 181 goto out; 182 } 183 184 *ba_ret = BIO_ADDR_dup(BIO_ADDRINFO_address(ai)); 185 } 186 187 /* Success, don't try any more addresses */ 188 break; 189 } 190 191 if (*sock == INVALID_SOCKET) { 192 if (bindaddr != NULL && !found) { 193 BIO_printf(bio_err, "Can't bind %saddress for %s%s%s\n", 194 #ifdef AF_INET6 195 BIO_ADDRINFO_family(res) == AF_INET6 ? "IPv6 " : 196 #endif 197 BIO_ADDRINFO_family(res) == AF_INET ? "IPv4 " : 198 BIO_ADDRINFO_family(res) == AF_UNIX ? "unix " : "", 199 bindhost != NULL ? bindhost : "", 200 bindport != NULL ? ":" : "", 201 bindport != NULL ? bindport : ""); 202 ERR_clear_error(); 203 ret = 0; 204 } 205 ERR_print_errors(bio_err); 206 } else { 207 char *hostname = NULL; 208 209 hostname = BIO_ADDR_hostname_string(BIO_ADDRINFO_address(ai), 1); 210 if (hostname != NULL) { 211 BIO_printf(bio_err, "Connecting to %s\n", hostname); 212 OPENSSL_free(hostname); 213 } 214 /* Remove any stale errors from previous connection attempts */ 215 ERR_clear_error(); 216 ret = 1; 217 } 218 out: 219 if (bindaddr != NULL) { 220 BIO_ADDRINFO_free (bindaddr); 221 } 222 BIO_ADDRINFO_free(res); 223 return ret; 224 } 225 226 void get_sock_info_address(int asock, char **hostname, char **service) 227 { 228 union BIO_sock_info_u info; 229 230 if (hostname != NULL) 231 *hostname = NULL; 232 if (service != NULL) 233 *service = NULL; 234 235 if ((info.addr = BIO_ADDR_new()) != NULL 236 && BIO_sock_info(asock, BIO_SOCK_INFO_ADDRESS, &info)) { 237 if (hostname != NULL) 238 *hostname = BIO_ADDR_hostname_string(info.addr, 1); 239 if (service != NULL) 240 *service = BIO_ADDR_service_string(info.addr, 1); 241 } 242 BIO_ADDR_free(info.addr); 243 } 244 245 int report_server_accept(BIO *out, int asock, int with_address, int with_pid) 246 { 247 int success = 1; 248 249 if (BIO_printf(out, "ACCEPT") <= 0) 250 return 0; 251 if (with_address) { 252 char *hostname, *service; 253 254 get_sock_info_address(asock, &hostname, &service); 255 success = hostname != NULL && service != NULL; 256 if (success) 257 success = BIO_printf(out, 258 strchr(hostname, ':') == NULL 259 ? /* IPv4 */ " %s:%s" 260 : /* IPv6 */ " [%s]:%s", 261 hostname, service) > 0; 262 else 263 (void)BIO_printf(out, "unknown:error\n"); 264 OPENSSL_free(hostname); 265 OPENSSL_free(service); 266 } 267 if (with_pid) 268 success *= BIO_printf(out, " PID=%d", getpid()) > 0; 269 success *= BIO_printf(out, "\n") > 0; 270 (void)BIO_flush(out); 271 272 return success; 273 } 274 275 /* 276 * do_server - helper routine to perform a server operation 277 * @accept_sock: pointer to storage of resulting socket. 278 * @host: the hostname or path (for AF_UNIX) to connect to. 279 * @port: the port to connect to (ignored for AF_UNIX). 280 * @family: desired socket family, may be AF_INET, AF_INET6, AF_UNIX or 281 * AF_UNSPEC 282 * @type: socket type, must be SOCK_STREAM or SOCK_DGRAM 283 * @cb: pointer to a function that receives the accepted socket and 284 * should perform the communication with the connecting client. 285 * @context: pointer to memory that's passed verbatim to the cb function. 286 * @naccept: number of times an incoming connect should be accepted. If -1, 287 * unlimited number. 288 * 289 * This will create a socket and use it to listen to a host:port, or if 290 * family == AF_UNIX, to the path found in host, then start accepting 291 * incoming connections and run cb on the resulting socket. 292 * 293 * 0 on failure, something other on success. 294 */ 295 int do_server(int *accept_sock, const char *host, const char *port, 296 int family, int type, int protocol, do_server_cb cb, 297 unsigned char *context, int naccept, BIO *bio_s_out, 298 int tfo) 299 { 300 int asock = 0; 301 int sock; 302 int i; 303 BIO_ADDRINFO *res = NULL; 304 const BIO_ADDRINFO *next; 305 int sock_family, sock_type, sock_protocol, sock_port; 306 const BIO_ADDR *sock_address; 307 int sock_family_fallback = AF_UNSPEC; 308 const BIO_ADDR *sock_address_fallback = NULL; 309 int sock_options = BIO_SOCK_REUSEADDR; 310 int ret = 0; 311 312 if (BIO_sock_init() != 1) 313 return 0; 314 315 if (!BIO_lookup_ex(host, port, BIO_LOOKUP_SERVER, family, type, protocol, 316 &res)) { 317 ERR_print_errors(bio_err); 318 return 0; 319 } 320 321 /* Admittedly, these checks are quite paranoid, we should not get 322 * anything in the BIO_ADDRINFO chain that we haven't asked for */ 323 OPENSSL_assert((family == AF_UNSPEC || family == BIO_ADDRINFO_family(res)) 324 && (type == 0 || type == BIO_ADDRINFO_socktype(res)) 325 && (protocol == 0 || protocol == BIO_ADDRINFO_protocol(res))); 326 327 sock_family = BIO_ADDRINFO_family(res); 328 sock_type = BIO_ADDRINFO_socktype(res); 329 sock_protocol = BIO_ADDRINFO_protocol(res); 330 sock_address = BIO_ADDRINFO_address(res); 331 next = BIO_ADDRINFO_next(res); 332 if (tfo && sock_type == SOCK_STREAM) 333 sock_options |= BIO_SOCK_TFO; 334 #ifdef AF_INET6 335 if (sock_family == AF_INET6) 336 sock_options |= BIO_SOCK_V6_ONLY; 337 if (next != NULL 338 && BIO_ADDRINFO_socktype(next) == sock_type 339 && BIO_ADDRINFO_protocol(next) == sock_protocol) { 340 if (sock_family == AF_INET 341 && BIO_ADDRINFO_family(next) == AF_INET6) { 342 /* In case AF_INET6 is returned but not supported by the 343 * kernel, retry with the first detected address family */ 344 sock_family_fallback = sock_family; 345 sock_address_fallback = sock_address; 346 sock_family = AF_INET6; 347 sock_address = BIO_ADDRINFO_address(next); 348 } else if (sock_family == AF_INET6 349 && BIO_ADDRINFO_family(next) == AF_INET) { 350 sock_options &= ~BIO_SOCK_V6_ONLY; 351 } 352 } 353 #endif 354 355 asock = BIO_socket(sock_family, sock_type, sock_protocol, 0); 356 if (asock == INVALID_SOCKET && sock_family_fallback != AF_UNSPEC) { 357 asock = BIO_socket(sock_family_fallback, sock_type, sock_protocol, 0); 358 sock_address = sock_address_fallback; 359 } 360 if (asock == INVALID_SOCKET 361 || !BIO_listen(asock, sock_address, sock_options)) { 362 BIO_ADDRINFO_free(res); 363 ERR_print_errors(bio_err); 364 if (asock != INVALID_SOCKET) 365 BIO_closesocket(asock); 366 goto end; 367 } 368 369 #ifndef OPENSSL_NO_SCTP 370 if (protocol == IPPROTO_SCTP) { 371 /* 372 * For SCTP we have to set various options on the socket prior to 373 * accepting. This is done automatically by BIO_new_dgram_sctp(). 374 * We don't actually need the created BIO though so we free it again 375 * immediately. 376 */ 377 BIO *tmpbio = BIO_new_dgram_sctp(asock, BIO_NOCLOSE); 378 379 if (tmpbio == NULL) { 380 BIO_closesocket(asock); 381 ERR_print_errors(bio_err); 382 goto end; 383 } 384 BIO_free(tmpbio); 385 } 386 #endif 387 388 sock_port = BIO_ADDR_rawport(sock_address); 389 390 BIO_ADDRINFO_free(res); 391 res = NULL; 392 393 if (!report_server_accept(bio_s_out, asock, sock_port == 0, 0)) { 394 BIO_closesocket(asock); 395 ERR_print_errors(bio_err); 396 goto end; 397 } 398 399 if (accept_sock != NULL) 400 *accept_sock = asock; 401 for (;;) { 402 char sink[64]; 403 struct timeval timeout; 404 fd_set readfds; 405 406 if (type == SOCK_STREAM) { 407 BIO_ADDR_free(ourpeer); 408 ourpeer = BIO_ADDR_new(); 409 if (ourpeer == NULL) { 410 BIO_closesocket(asock); 411 ERR_print_errors(bio_err); 412 goto end; 413 } 414 do { 415 sock = BIO_accept_ex(asock, ourpeer, 0); 416 } while (sock < 0 && BIO_sock_should_retry(sock)); 417 if (sock < 0) { 418 ERR_print_errors(bio_err); 419 BIO_closesocket(asock); 420 break; 421 } 422 423 if (naccept != -1) 424 naccept--; 425 if (naccept == 0) 426 BIO_closesocket(asock); 427 428 BIO_set_tcp_ndelay(sock, 1); 429 i = (*cb)(sock, type, protocol, context); 430 431 /* 432 * If we ended with an alert being sent, but still with data in the 433 * network buffer to be read, then calling BIO_closesocket() will 434 * result in a TCP-RST being sent. On some platforms (notably 435 * Windows) then this will result in the peer immediately abandoning 436 * the connection including any buffered alert data before it has 437 * had a chance to be read. Shutting down the sending side first, 438 * and then closing the socket sends TCP-FIN first followed by 439 * TCP-RST. This seems to allow the peer to read the alert data. 440 */ 441 shutdown(sock, 1); /* SHUT_WR */ 442 /* 443 * We just said we have nothing else to say, but it doesn't mean 444 * that the other side has nothing. It's even recommended to 445 * consume incoming data. [In testing context this ensures that 446 * alerts are passed on...] 447 */ 448 timeout.tv_sec = 0; 449 timeout.tv_usec = 500000; /* some extreme round-trip */ 450 do { 451 FD_ZERO(&readfds); 452 openssl_fdset(sock, &readfds); 453 } while (select(sock + 1, &readfds, NULL, NULL, &timeout) > 0 454 && readsocket(sock, sink, sizeof(sink)) > 0); 455 456 BIO_closesocket(sock); 457 } else { 458 if (naccept != -1) 459 naccept--; 460 461 i = (*cb)(asock, type, protocol, context); 462 } 463 464 if (i < 0 || naccept == 0) { 465 BIO_closesocket(asock); 466 ret = i; 467 break; 468 } 469 } 470 end: 471 # ifdef AF_UNIX 472 if (family == AF_UNIX) 473 unlink(host); 474 # endif 475 BIO_ADDR_free(ourpeer); 476 ourpeer = NULL; 477 return ret; 478 } 479 480 void do_ssl_shutdown(SSL *ssl) 481 { 482 int ret; 483 484 do { 485 /* We only do unidirectional shutdown */ 486 ret = SSL_shutdown(ssl); 487 if (ret < 0) { 488 switch (SSL_get_error(ssl, ret)) { 489 case SSL_ERROR_WANT_READ: 490 case SSL_ERROR_WANT_WRITE: 491 case SSL_ERROR_WANT_ASYNC: 492 case SSL_ERROR_WANT_ASYNC_JOB: 493 /* We just do busy waiting. Nothing clever */ 494 continue; 495 } 496 ret = 0; 497 } 498 } while (ret < 0); 499 } 500 501 #endif /* OPENSSL_NO_SOCK */ 502