1 /* 2 * Copyright 1995-2026 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 BIO_closesocket(*sock); 158 *sock = INVALID_SOCKET; 159 continue; 160 } 161 BIO_free(tmpbio); 162 } 163 #endif 164 if (BIO_ADDRINFO_protocol(ai) == IPPROTO_TCP) { 165 options |= BIO_SOCK_NODELAY; 166 if (tfo) 167 options |= BIO_SOCK_TFO; 168 } 169 170 if (doconn && !BIO_connect(*sock, BIO_ADDRINFO_address(ai), options)) { 171 BIO_closesocket(*sock); 172 *sock = INVALID_SOCKET; 173 continue; 174 } 175 176 /* Save the address */ 177 if (tfo || !doconn) { 178 if (ba_ret == NULL) { 179 BIO_printf(bio_err, "Internal error\n"); 180 BIO_closesocket(*sock); 181 *sock = INVALID_SOCKET; 182 goto out; 183 } 184 185 *ba_ret = BIO_ADDR_dup(BIO_ADDRINFO_address(ai)); 186 } 187 188 /* Success, don't try any more addresses */ 189 break; 190 } 191 192 if (*sock == INVALID_SOCKET) { 193 if (bindaddr != NULL && !found) { 194 BIO_printf(bio_err, "Can't bind %saddress for %s%s%s\n", 195 #ifdef AF_INET6 196 BIO_ADDRINFO_family(res) == AF_INET6 ? "IPv6 " : 197 #endif 198 BIO_ADDRINFO_family(res) == AF_INET ? "IPv4 " 199 : BIO_ADDRINFO_family(res) == AF_UNIX ? "unix " 200 : "", 201 bindhost != NULL ? bindhost : "", 202 bindport != NULL ? ":" : "", 203 bindport != NULL ? bindport : ""); 204 ERR_clear_error(); 205 ret = 0; 206 } 207 ERR_print_errors(bio_err); 208 } else { 209 char *hostname = NULL; 210 211 hostname = BIO_ADDR_hostname_string(BIO_ADDRINFO_address(ai), 1); 212 if (hostname != NULL) { 213 BIO_printf(bio_err, "Connecting to %s\n", hostname); 214 OPENSSL_free(hostname); 215 } 216 /* Remove any stale errors from previous connection attempts */ 217 ERR_clear_error(); 218 ret = 1; 219 } 220 out: 221 if (bindaddr != NULL) { 222 BIO_ADDRINFO_free(bindaddr); 223 } 224 BIO_ADDRINFO_free(res); 225 return ret; 226 } 227 228 void get_sock_info_address(int asock, char **hostname, char **service) 229 { 230 union BIO_sock_info_u info; 231 232 if (hostname != NULL) 233 *hostname = NULL; 234 if (service != NULL) 235 *service = NULL; 236 237 if ((info.addr = BIO_ADDR_new()) != NULL 238 && BIO_sock_info(asock, BIO_SOCK_INFO_ADDRESS, &info)) { 239 if (hostname != NULL) 240 *hostname = BIO_ADDR_hostname_string(info.addr, 1); 241 if (service != NULL) 242 *service = BIO_ADDR_service_string(info.addr, 1); 243 } 244 BIO_ADDR_free(info.addr); 245 } 246 247 int report_server_accept(BIO *out, int asock, int with_address, int with_pid) 248 { 249 int success = 1; 250 251 if (BIO_printf(out, "ACCEPT") <= 0) 252 return 0; 253 if (with_address) { 254 char *hostname, *service; 255 256 get_sock_info_address(asock, &hostname, &service); 257 success = hostname != NULL && service != NULL; 258 if (success) 259 success = BIO_printf(out, 260 strchr(hostname, ':') == NULL 261 ? /* IPv4 */ " %s:%s" 262 : /* IPv6 */ " [%s]:%s", 263 hostname, service) 264 > 0; 265 else 266 (void)BIO_printf(out, "unknown:error\n"); 267 OPENSSL_free(hostname); 268 OPENSSL_free(service); 269 } 270 if (with_pid) 271 success *= BIO_printf(out, " PID=%d", getpid()) > 0; 272 success *= BIO_printf(out, "\n") > 0; 273 (void)BIO_flush(out); 274 275 return success; 276 } 277 278 /* 279 * do_server - helper routine to perform a server operation 280 * @accept_sock: pointer to storage of resulting socket. 281 * @host: the hostname or path (for AF_UNIX) to connect to. 282 * @port: the port to connect to (ignored for AF_UNIX). 283 * @family: desired socket family, may be AF_INET, AF_INET6, AF_UNIX or 284 * AF_UNSPEC 285 * @type: socket type, must be SOCK_STREAM or SOCK_DGRAM 286 * @cb: pointer to a function that receives the accepted socket and 287 * should perform the communication with the connecting client. 288 * @context: pointer to memory that's passed verbatim to the cb function. 289 * @naccept: number of times an incoming connect should be accepted. If -1, 290 * unlimited number. 291 * 292 * This will create a socket and use it to listen to a host:port, or if 293 * family == AF_UNIX, to the path found in host, then start accepting 294 * incoming connections and run cb on the resulting socket. 295 * 296 * 0 on failure, something other on success. 297 */ 298 int do_server(int *accept_sock, const char *host, const char *port, 299 int family, int type, int protocol, do_server_cb cb, 300 unsigned char *context, int naccept, BIO *bio_s_out, 301 int tfo) 302 { 303 int asock = 0; 304 int sock; 305 int i; 306 BIO_ADDRINFO *res = NULL; 307 const BIO_ADDRINFO *next; 308 int sock_family, sock_type, sock_protocol, sock_port; 309 const BIO_ADDR *sock_address; 310 int sock_family_fallback = AF_UNSPEC; 311 const BIO_ADDR *sock_address_fallback = NULL; 312 int sock_options = BIO_SOCK_REUSEADDR; 313 int ret = 0; 314 315 if (BIO_sock_init() != 1) 316 return 0; 317 318 if (!BIO_lookup_ex(host, port, BIO_LOOKUP_SERVER, family, type, protocol, 319 &res)) { 320 ERR_print_errors(bio_err); 321 return 0; 322 } 323 324 /* Admittedly, these checks are quite paranoid, we should not get 325 * anything in the BIO_ADDRINFO chain that we haven't asked for */ 326 OPENSSL_assert((family == AF_UNSPEC || family == BIO_ADDRINFO_family(res)) 327 && (type == 0 || type == BIO_ADDRINFO_socktype(res)) 328 && (protocol == 0 || protocol == BIO_ADDRINFO_protocol(res))); 329 330 sock_family = BIO_ADDRINFO_family(res); 331 sock_type = BIO_ADDRINFO_socktype(res); 332 sock_protocol = BIO_ADDRINFO_protocol(res); 333 sock_address = BIO_ADDRINFO_address(res); 334 next = BIO_ADDRINFO_next(res); 335 if (tfo && sock_type == SOCK_STREAM) 336 sock_options |= BIO_SOCK_TFO; 337 #ifdef AF_INET6 338 if (sock_family == AF_INET6) 339 sock_options |= BIO_SOCK_V6_ONLY; 340 if (next != NULL 341 && BIO_ADDRINFO_socktype(next) == sock_type 342 && BIO_ADDRINFO_protocol(next) == sock_protocol) { 343 if (sock_family == AF_INET 344 && BIO_ADDRINFO_family(next) == AF_INET6) { 345 /* In case AF_INET6 is returned but not supported by the 346 * kernel, retry with the first detected address family */ 347 sock_family_fallback = sock_family; 348 sock_address_fallback = sock_address; 349 sock_family = AF_INET6; 350 sock_address = BIO_ADDRINFO_address(next); 351 } else if (sock_family == AF_INET6 352 && BIO_ADDRINFO_family(next) == AF_INET) { 353 sock_options &= ~BIO_SOCK_V6_ONLY; 354 } 355 } 356 #endif 357 358 asock = BIO_socket(sock_family, sock_type, sock_protocol, 0); 359 if (asock == INVALID_SOCKET && sock_family_fallback != AF_UNSPEC) { 360 asock = BIO_socket(sock_family_fallback, sock_type, sock_protocol, 0); 361 sock_address = sock_address_fallback; 362 } 363 if (asock == INVALID_SOCKET 364 || !BIO_listen(asock, sock_address, sock_options)) { 365 BIO_ADDRINFO_free(res); 366 ERR_print_errors(bio_err); 367 if (asock != INVALID_SOCKET) 368 BIO_closesocket(asock); 369 goto end; 370 } 371 372 #ifndef OPENSSL_NO_SCTP 373 if (protocol == IPPROTO_SCTP) { 374 /* 375 * For SCTP we have to set various options on the socket prior to 376 * accepting. This is done automatically by BIO_new_dgram_sctp(). 377 * We don't actually need the created BIO though so we free it again 378 * immediately. 379 */ 380 BIO *tmpbio = BIO_new_dgram_sctp(asock, BIO_NOCLOSE); 381 382 if (tmpbio == NULL) { 383 BIO_ADDRINFO_free(res); 384 BIO_closesocket(asock); 385 ERR_print_errors(bio_err); 386 goto end; 387 } 388 BIO_free(tmpbio); 389 } 390 #endif 391 392 sock_port = BIO_ADDR_rawport(sock_address); 393 394 BIO_ADDRINFO_free(res); 395 res = NULL; 396 397 if (!report_server_accept(bio_s_out, asock, sock_port == 0, 0)) { 398 BIO_closesocket(asock); 399 ERR_print_errors(bio_err); 400 goto end; 401 } 402 403 if (accept_sock != NULL) 404 *accept_sock = asock; 405 for (;;) { 406 char sink[64]; 407 struct timeval timeout; 408 fd_set readfds; 409 410 if (type == SOCK_STREAM) { 411 BIO_ADDR_free(ourpeer); 412 ourpeer = BIO_ADDR_new(); 413 if (ourpeer == NULL) { 414 BIO_closesocket(asock); 415 ERR_print_errors(bio_err); 416 goto end; 417 } 418 do { 419 sock = BIO_accept_ex(asock, ourpeer, 0); 420 } while (sock < 0 && BIO_sock_should_retry(sock)); 421 if (sock < 0) { 422 ERR_print_errors(bio_err); 423 BIO_closesocket(asock); 424 break; 425 } 426 427 if (naccept != -1) 428 naccept--; 429 430 BIO_set_tcp_ndelay(sock, 1); 431 i = (*cb)(sock, type, protocol, context); 432 433 /* 434 * If we ended with an alert being sent, but still with data in the 435 * network buffer to be read, then calling BIO_closesocket() will 436 * result in a TCP-RST being sent. On some platforms (notably 437 * Windows) then this will result in the peer immediately abandoning 438 * the connection including any buffered alert data before it has 439 * had a chance to be read. Shutting down the sending side first, 440 * and then closing the socket sends TCP-FIN first followed by 441 * TCP-RST. This seems to allow the peer to read the alert data. 442 */ 443 shutdown(sock, 1); /* SHUT_WR */ 444 /* 445 * We just said we have nothing else to say, but it doesn't mean 446 * that the other side has nothing. It's even recommended to 447 * consume incoming data. [In testing context this ensures that 448 * alerts are passed on...] 449 */ 450 timeout.tv_sec = 0; 451 timeout.tv_usec = 500000; /* some extreme round-trip */ 452 do { 453 FD_ZERO(&readfds); 454 openssl_fdset(sock, &readfds); 455 } while (select(sock + 1, &readfds, NULL, NULL, &timeout) > 0 456 && readsocket(sock, sink, sizeof(sink)) > 0); 457 458 BIO_closesocket(sock); 459 } else { 460 if (naccept != -1) 461 naccept--; 462 463 i = (*cb)(asock, type, protocol, context); 464 } 465 466 if (i < 0 || naccept == 0) { 467 BIO_closesocket(asock); 468 asock = INVALID_SOCKET; 469 ret = i; 470 break; 471 } 472 } 473 end: 474 #ifdef AF_UNIX 475 if (family == AF_UNIX) 476 unlink(host); 477 #endif 478 BIO_ADDR_free(ourpeer); 479 ourpeer = NULL; 480 return ret; 481 } 482 483 void do_ssl_shutdown(SSL *ssl) 484 { 485 int ret; 486 487 do { 488 /* We only do unidirectional shutdown */ 489 ret = SSL_shutdown(ssl); 490 if (ret < 0) { 491 switch (SSL_get_error(ssl, ret)) { 492 case SSL_ERROR_WANT_READ: 493 case SSL_ERROR_WANT_WRITE: 494 case SSL_ERROR_WANT_ASYNC: 495 case SSL_ERROR_WANT_ASYNC_JOB: 496 /* We just do busy waiting. Nothing clever */ 497 continue; 498 } 499 ret = 0; 500 } 501 } while (ret < 0); 502 } 503 504 #endif /* OPENSSL_NO_SOCK */ 505