apps/lib/s_socket.c

   1 /*
   2  * Copyright 1995-2022 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 "apps.h"
  41 # include "s_apps.h"
  42 # include "internal/sockets.h"
  43
  44 # if defined(__TANDEM)
  45 #  if defined(OPENSSL_TANDEM_FLOSS)
  46 #   include <floss.h(floss_read)>
  47 #  endif
  48 # endif
  49
  50 # include <openssl/bio.h>
  51 # include <openssl/err.h>
  52
  53 /* Keep track of our peer's address for the cookie callback */
  54 BIO_ADDR *ourpeer = NULL;
  55
  56 /*
  57  * init_client - helper routine to set up socket communication
  58  * @sock: pointer to storage of resulting socket.
  59  * @host: the host name or path (for AF_UNIX) to connect to.
  60  * @port: the port to connect to (ignored for AF_UNIX).
  61  * @bindhost: source host or path (for AF_UNIX).
  62  * @bindport: source port (ignored for AF_UNIX).
  63  * @family: desired socket family, may be AF_INET, AF_INET6, AF_UNIX or
  64  *  AF_UNSPEC
  65  * @type: socket type, must be SOCK_STREAM or SOCK_DGRAM
  66  * @protocol: socket protocol, e.g. IPPROTO_TCP or IPPROTO_UDP (or 0 for any)
  67  * @tfo: flag to enable TCP Fast Open
  68  * @ba_ret: BIO_ADDR that was connected to for TFO, to be freed by caller
  69  *
  70  * This will create a socket and use it to connect to a host:port, or if
  71  * family == AF_UNIX, to the path found in host.
  72  *
  73  * If the host has more than one address, it will try them one by one until
  74  * a successful connection is established.  The resulting socket will be
  75  * found in *sock on success, it will be given INVALID_SOCKET otherwise.
  76  *
  77  * Returns 1 on success, 0 on failure.
  78  */
  79 int init_client(int *sock, const char *host, const char *port,
  80                 const char *bindhost, const char *bindport,
  81                 int family, int type, int protocol, int tfo,
  82                 BIO_ADDR **ba_ret)
  83 {
  84     BIO_ADDRINFO *res = NULL;
  85     BIO_ADDRINFO *bindaddr = NULL;
  86     const BIO_ADDRINFO *ai = NULL;
  87     const BIO_ADDRINFO *bi = NULL;
  88     int found = 0;
  89     int ret;
  90     int options = 0;
  91
  92     if (tfo && ba_ret != NULL)
  93         *ba_ret = NULL;
  94
  95     if (BIO_sock_init() != 1)
  96         return 0;
  97
  98     ret = BIO_lookup_ex(host, port, BIO_LOOKUP_CLIENT, family, type, protocol,
  99                         &res);
 100     if (ret == 0) {
 101         ERR_print_errors(bio_err);
 102         return 0;
 103     }
 104
 105     if (bindhost != NULL || bindport != NULL) {
 106         ret = BIO_lookup_ex(bindhost, bindport, BIO_LOOKUP_CLIENT,
 107                             family, type, protocol, &bindaddr);
 108         if (ret == 0) {
 109             ERR_print_errors (bio_err);
 110             goto out;
 111         }
 112     }
 113
 114     ret = 0;
 115     for (ai = res; ai != NULL; ai = BIO_ADDRINFO_next(ai)) {
 116         /* Admittedly, these checks are quite paranoid, we should not get
 117          * anything in the BIO_ADDRINFO chain that we haven't
 118          * asked for. */
 119         OPENSSL_assert((family == AF_UNSPEC
 120                         || family == BIO_ADDRINFO_family(ai))
 121                        && (type == 0 || type == BIO_ADDRINFO_socktype(ai))
 122                        && (protocol == 0
 123                            || protocol == BIO_ADDRINFO_protocol(ai)));
 124
 125         if (bindaddr != NULL) {
 126             for (bi = bindaddr; bi != NULL; bi = BIO_ADDRINFO_next(bi)) {
 127                 if (BIO_ADDRINFO_family(bi) == BIO_ADDRINFO_family(ai))
 128                     break;
 129             }
 130             if (bi == NULL)
 131                 continue;
 132             ++found;
 133         }
 134
 135         *sock = BIO_socket(BIO_ADDRINFO_family(ai), BIO_ADDRINFO_socktype(ai),
 136                            BIO_ADDRINFO_protocol(ai), 0);
 137         if (*sock == INVALID_SOCKET) {
 138             /* Maybe the kernel doesn't support the socket family, even if
 139              * BIO_lookup() added it in the returned result...
 140              */
 141             continue;
 142         }
 143
 144         if (bi != NULL) {
 145             if (!BIO_bind(*sock, BIO_ADDRINFO_address(bi),
 146                           BIO_SOCK_REUSEADDR)) {
 147                 BIO_closesocket(*sock);
 148                 *sock = INVALID_SOCKET;
 149                 break;
 150             }
 151         }
 152
 153 #ifndef OPENSSL_NO_SCTP
 154         if (protocol == IPPROTO_SCTP) {
 155             /*
 156              * For SCTP we have to set various options on the socket prior to
 157              * connecting. This is done automatically by BIO_new_dgram_sctp().
 158              * We don't actually need the created BIO though so we free it again
 159              * immediately.
 160              */
 161             BIO *tmpbio = BIO_new_dgram_sctp(*sock, BIO_NOCLOSE);
 162
 163             if (tmpbio == NULL) {
 164                 ERR_print_errors(bio_err);
 165                 return 0;
 166             }
 167             BIO_free(tmpbio);
 168         }
 169 #endif
 170         if (BIO_ADDRINFO_protocol(ai) == IPPROTO_TCP) {
 171             options |= BIO_SOCK_NODELAY;
 172             if (tfo)
 173                 options |= BIO_SOCK_TFO;
 174         }
 175
 176         if (!BIO_connect(*sock, BIO_ADDRINFO_address(ai), options)) {
 177             BIO_closesocket(*sock);
 178             *sock = INVALID_SOCKET;
 179             continue;
 180         }
 181
 182         /* Save the address */
 183         if (tfo && ba_ret != NULL)
 184             *ba_ret = BIO_ADDR_dup(BIO_ADDRINFO_address(ai));
 185
 186         /* Success, don't try any more addresses */
 187         break;
 188     }
 189
 190     if (*sock == INVALID_SOCKET) {
 191         if (bindaddr != NULL && !found) {
 192             BIO_printf(bio_err, "Can't bind %saddress for %s%s%s\n",
 193 #ifdef AF_INET6
 194                        BIO_ADDRINFO_family(res) == AF_INET6 ? "IPv6 " :
 195 #endif
 196                        BIO_ADDRINFO_family(res) == AF_INET ? "IPv4 " :
 197                        BIO_ADDRINFO_family(res) == AF_UNIX ? "unix " : "",
 198                        bindhost != NULL ? bindhost : "",
 199                        bindport != NULL ? ":" : "",
 200                        bindport != NULL ? bindport : "");
 201             ERR_clear_error();
 202             ret = 0;
 203         }
 204         ERR_print_errors(bio_err);
 205     } else {
 206         char *hostname = NULL;
 207
 208         hostname = BIO_ADDR_hostname_string(BIO_ADDRINFO_address(ai), 1);
 209         if (hostname != NULL) {
 210             BIO_printf(bio_out, "Connecting to %s\n", hostname);
 211             OPENSSL_free(hostname);
 212         }
 213         /* Remove any stale errors from previous connection attempts */
 214         ERR_clear_error();
 215         ret = 1;
 216     }
 217 out:
 218     if (bindaddr != NULL) {
 219         BIO_ADDRINFO_free (bindaddr);
 220     }
 221     BIO_ADDRINFO_free(res);
 222     return ret;
 223 }
 224
 225 void get_sock_info_address(int asock, char **hostname, char **service)
 226 {
 227     union BIO_sock_info_u info;
 228
 229     if (hostname != NULL)
 230         *hostname = NULL;
 231     if (service != NULL)
 232         *service = NULL;
 233
 234     if ((info.addr = BIO_ADDR_new()) != NULL
 235             && BIO_sock_info(asock, BIO_SOCK_INFO_ADDRESS, &info)) {
 236         if (hostname != NULL)
 237             *hostname = BIO_ADDR_hostname_string(info.addr, 1);
 238         if (service != NULL)
 239             *service = BIO_ADDR_service_string(info.addr, 1);
 240     }
 241     BIO_ADDR_free(info.addr);
 242 }
 243
 244 int report_server_accept(BIO *out, int asock, int with_address, int with_pid)
 245 {
 246     int success = 1;
 247
 248     if (BIO_printf(out, "ACCEPT") <= 0)
 249         return 0;
 250     if (with_address) {
 251         char *hostname, *service;
 252
 253         get_sock_info_address(asock, &hostname, &service);
 254         success = hostname != NULL && service != NULL;
 255         if (success)
 256             success = BIO_printf(out,
 257                                  strchr(hostname, ':') == NULL
 258                                  ? /* IPv4 */ " %s:%s"
 259                                  : /* IPv6 */ " [%s]:%s",
 260                                  hostname, service) > 0;
 261         else
 262             (void)BIO_printf(out, "unknown:error\n");
 263         OPENSSL_free(hostname);
 264         OPENSSL_free(service);
 265     }
 266     if (with_pid)
 267         success *= BIO_printf(out, " PID=%d", getpid()) > 0;
 268     success *= BIO_printf(out, "\n") > 0;
 269     (void)BIO_flush(out);
 270
 271     return success;
 272 }
 273
 274 /*
 275  * do_server - helper routine to perform a server operation
 276  * @accept_sock: pointer to storage of resulting socket.
 277  * @host: the host name or path (for AF_UNIX) to connect to.
 278  * @port: the port to connect to (ignored for AF_UNIX).
 279  * @family: desired socket family, may be AF_INET, AF_INET6, AF_UNIX or
 280  *  AF_UNSPEC
 281  * @type: socket type, must be SOCK_STREAM or SOCK_DGRAM
 282  * @cb: pointer to a function that receives the accepted socket and
 283  *  should perform the communication with the connecting client.
 284  * @context: pointer to memory that's passed verbatim to the cb function.
 285  * @naccept: number of times an incoming connect should be accepted.  If -1,
 286  *  unlimited number.
 287  *
 288  * This will create a socket and use it to listen to a host:port, or if
 289  * family == AF_UNIX, to the path found in host, then start accepting
 290  * incoming connections and run cb on the resulting socket.
 291  *
 292  * 0 on failure, something other on success.
 293  */
 294 int do_server(int *accept_sock, const char *host, const char *port,
 295               int family, int type, int protocol, do_server_cb cb,
 296               unsigned char *context, int naccept, BIO *bio_s_out,
 297               int tfo)
 298 {
 299     int asock = 0;
 300     int sock;
 301     int i;
 302     BIO_ADDRINFO *res = NULL;
 303     const BIO_ADDRINFO *next;
 304     int sock_family, sock_type, sock_protocol, sock_port;
 305     const BIO_ADDR *sock_address;
 306     int sock_family_fallback = AF_UNSPEC;
 307     const BIO_ADDR *sock_address_fallback = NULL;
 308     int sock_options = BIO_SOCK_REUSEADDR;
 309     int ret = 0;
 310
 311     if (BIO_sock_init() != 1)
 312         return 0;
 313
 314     if (!BIO_lookup_ex(host, port, BIO_LOOKUP_SERVER, family, type, protocol,
 315                        &res)) {
 316         ERR_print_errors(bio_err);
 317         return 0;
 318     }
 319
 320     /* Admittedly, these checks are quite paranoid, we should not get
 321      * anything in the BIO_ADDRINFO chain that we haven't asked for */
 322     OPENSSL_assert((family == AF_UNSPEC || family == BIO_ADDRINFO_family(res))
 323                    && (type == 0 || type == BIO_ADDRINFO_socktype(res))
 324                    && (protocol == 0 || protocol == BIO_ADDRINFO_protocol(res)));
 325
 326     sock_family = BIO_ADDRINFO_family(res);
 327     sock_type = BIO_ADDRINFO_socktype(res);
 328     sock_protocol = BIO_ADDRINFO_protocol(res);
 329     sock_address = BIO_ADDRINFO_address(res);
 330     next = BIO_ADDRINFO_next(res);
 331     if (tfo && sock_type == SOCK_STREAM)
 332         sock_options |= BIO_SOCK_TFO;
 333 #ifdef AF_INET6
 334     if (sock_family == AF_INET6)
 335         sock_options |= BIO_SOCK_V6_ONLY;
 336     if (next != NULL
 337             && BIO_ADDRINFO_socktype(next) == sock_type
 338             && BIO_ADDRINFO_protocol(next) == sock_protocol) {
 339         if (sock_family == AF_INET
 340                 && BIO_ADDRINFO_family(next) == AF_INET6) {
 341             /* In case AF_INET6 is returned but not supported by the
 342              * kernel, retry with the first detected address family */
 343             sock_family_fallback = sock_family;
 344             sock_address_fallback = sock_address;
 345             sock_family = AF_INET6;
 346             sock_address = BIO_ADDRINFO_address(next);
 347         } else if (sock_family == AF_INET6
 348                    && BIO_ADDRINFO_family(next) == AF_INET) {
 349             sock_options &= ~BIO_SOCK_V6_ONLY;
 350         }
 351     }
 352 #endif
 353
 354     asock = BIO_socket(sock_family, sock_type, sock_protocol, 0);
 355     if (asock == INVALID_SOCKET && sock_family_fallback != AF_UNSPEC) {
 356         asock = BIO_socket(sock_family_fallback, sock_type, sock_protocol, 0);
 357         sock_address = sock_address_fallback;
 358     }
 359     if (asock == INVALID_SOCKET
 360         || !BIO_listen(asock, sock_address, sock_options)) {
 361         BIO_ADDRINFO_free(res);
 362         ERR_print_errors(bio_err);
 363         if (asock != INVALID_SOCKET)
 364             BIO_closesocket(asock);
 365         goto end;
 366     }
 367
 368 #ifndef OPENSSL_NO_SCTP
 369     if (protocol == IPPROTO_SCTP) {
 370         /*
 371          * For SCTP we have to set various options on the socket prior to
 372          * accepting. This is done automatically by BIO_new_dgram_sctp().
 373          * We don't actually need the created BIO though so we free it again
 374          * immediately.
 375          */
 376         BIO *tmpbio = BIO_new_dgram_sctp(asock, BIO_NOCLOSE);
 377
 378         if (tmpbio == NULL) {
 379             BIO_closesocket(asock);
 380             ERR_print_errors(bio_err);
 381             goto end;
 382         }
 383         BIO_free(tmpbio);
 384     }
 385 #endif
 386
 387     sock_port = BIO_ADDR_rawport(sock_address);
 388
 389     BIO_ADDRINFO_free(res);
 390     res = NULL;
 391
 392     if (!report_server_accept(bio_s_out, asock, sock_port == 0, 0)) {
 393         BIO_closesocket(asock);
 394         ERR_print_errors(bio_err);
 395         goto end;
 396     }
 397
 398     if (accept_sock != NULL)
 399         *accept_sock = asock;
 400     for (;;) {
 401         char sink[64];
 402         struct timeval timeout;
 403         fd_set readfds;
 404
 405         if (type == SOCK_STREAM) {
 406             BIO_ADDR_free(ourpeer);
 407             ourpeer = BIO_ADDR_new();
 408             if (ourpeer == NULL) {
 409                 BIO_closesocket(asock);
 410                 ERR_print_errors(bio_err);
 411                 goto end;
 412             }
 413             do {
 414                 sock = BIO_accept_ex(asock, ourpeer, 0);
 415             } while (sock < 0 && BIO_sock_should_retry(sock));
 416             if (sock < 0) {
 417                 ERR_print_errors(bio_err);
 418                 BIO_closesocket(asock);
 419                 break;
 420             }
 421             BIO_set_tcp_ndelay(sock, 1);
 422             i = (*cb)(sock, type, protocol, context);
 423
 424             /*
 425              * If we ended with an alert being sent, but still with data in the
 426              * network buffer to be read, then calling BIO_closesocket() will
 427              * result in a TCP-RST being sent. On some platforms (notably
 428              * Windows) then this will result in the peer immediately abandoning
 429              * the connection including any buffered alert data before it has
 430              * had a chance to be read. Shutting down the sending side first,
 431              * and then closing the socket sends TCP-FIN first followed by
 432              * TCP-RST. This seems to allow the peer to read the alert data.
 433              */
 434             shutdown(sock, 1); /* SHUT_WR */
 435             /*
 436              * We just said we have nothing else to say, but it doesn't mean
 437              * that the other side has nothing. It's even recommended to
 438              * consume incoming data. [In testing context this ensures that
 439              * alerts are passed on...]
 440              */
 441             timeout.tv_sec = 0;
 442             timeout.tv_usec = 500000;  /* some extreme round-trip */
 443             do {
 444                 FD_ZERO(&readfds);
 445                 openssl_fdset(sock, &readfds);
 446             } while (select(sock + 1, &readfds, NULL, NULL, &timeout) > 0
 447                      && readsocket(sock, sink, sizeof(sink)) > 0);
 448
 449             BIO_closesocket(sock);
 450         } else {
 451             i = (*cb)(asock, type, protocol, context);
 452         }
 453
 454         if (naccept != -1)
 455             naccept--;
 456         if (i < 0 || naccept == 0) {
 457             BIO_closesocket(asock);
 458             ret = i;
 459             break;
 460         }
 461     }
 462  end:
 463 # ifdef AF_UNIX
 464     if (family == AF_UNIX)
 465         unlink(host);
 466 # endif
 467     BIO_ADDR_free(ourpeer);
 468     ourpeer = NULL;
 469     return ret;
 470 }
 471
 472 void do_ssl_shutdown(SSL *ssl)
 473 {
 474     int ret;
 475
 476     do {
 477         /* We only do unidirectional shutdown */
 478         ret = SSL_shutdown(ssl);
 479         if (ret < 0) {
 480             switch (SSL_get_error(ssl, ret)) {
 481             case SSL_ERROR_WANT_READ:
 482             case SSL_ERROR_WANT_WRITE:
 483             case SSL_ERROR_WANT_ASYNC:
 484             case SSL_ERROR_WANT_ASYNC_JOB:
 485                 /* We just do busy waiting. Nothing clever */
 486                 continue;
 487             }
 488             ret = 0;
 489         }
 490     } while (ret < 0);
 491 }
 492
 493 #endif  /* OPENSSL_NO_SOCK */