apps/s_socket.c

   1 /*
   2  * Copyright 1995-2018 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 #ifndef OPENSSL_NO_SOCK
  30
  31 # include "apps.h"
  32 # include "s_apps.h"
  33 # include "internal/sockets.h"
  34
  35 # include <openssl/bio.h>
  36 # include <openssl/err.h>
  37
  38 /* Keep track of our peer's address for the cookie callback */
  39 BIO_ADDR *ourpeer = NULL;
  40
  41 /*
  42  * init_client - helper routine to set up socket communication
  43  * @sock: pointer to storage of resulting socket.
  44  * @host: the host name or path (for AF_UNIX) to connect to.
  45  * @port: the port to connect to (ignored for AF_UNIX).
  46  * @bindhost: source host or path (for AF_UNIX).
  47  * @bindport: source port (ignored for AF_UNIX).
  48  * @family: desired socket family, may be AF_INET, AF_INET6, AF_UNIX or
  49  *  AF_UNSPEC
  50  * @type: socket type, must be SOCK_STREAM or SOCK_DGRAM
  51  * @protocol: socket protocol, e.g. IPPROTO_TCP or IPPROTO_UDP (or 0 for any)
  52  *
  53  * This will create a socket and use it to connect to a host:port, or if
  54  * family == AF_UNIX, to the path found in host.
  55  *
  56  * If the host has more than one address, it will try them one by one until
  57  * a successful connection is established.  The resulting socket will be
  58  * found in *sock on success, it will be given INVALID_SOCKET otherwise.
  59  *
  60  * Returns 1 on success, 0 on failure.
  61  */
  62 int init_client(int *sock, const char *host, const char *port,
  63                 const char *bindhost, const char *bindport,
  64                 int family, int type, int protocol)
  65 {
  66     BIO_ADDRINFO *res = NULL;
  67     BIO_ADDRINFO *bindaddr = NULL;
  68     const BIO_ADDRINFO *ai = NULL;
  69     const BIO_ADDRINFO *bi = NULL;
  70     int found = 0;
  71     int ret;
  72
  73     if (BIO_sock_init() != 1)
  74         return 0;
  75
  76     ret = BIO_lookup_ex(host, port, BIO_LOOKUP_CLIENT, family, type, protocol,
  77                         &res);
  78     if (ret == 0) {
  79         ERR_print_errors(bio_err);
  80         return 0;
  81     }
  82
  83     if (bindhost != NULL || bindport != NULL) {
  84         ret = BIO_lookup_ex(bindhost, bindport, BIO_LOOKUP_CLIENT,
  85                             family, type, protocol, &bindaddr);
  86         if (ret == 0) {
  87             ERR_print_errors (bio_err);
  88             goto out;
  89         }
  90     }
  91
  92     ret = 0;
  93     for (ai = res; ai != NULL; ai = BIO_ADDRINFO_next(ai)) {
  94         /* Admittedly, these checks are quite paranoid, we should not get
  95          * anything in the BIO_ADDRINFO chain that we haven't
  96          * asked for. */
  97         OPENSSL_assert((family == AF_UNSPEC
  98                         || family == BIO_ADDRINFO_family(ai))
  99                        && (type == 0 || type == BIO_ADDRINFO_socktype(ai))
 100                        && (protocol == 0
 101                            || protocol == BIO_ADDRINFO_protocol(ai)));
 102
 103         if (bindaddr != NULL) {
 104             for (bi = bindaddr; bi != NULL; bi = BIO_ADDRINFO_next(bi)) {
 105                 if (BIO_ADDRINFO_family(bi) == BIO_ADDRINFO_family(ai))
 106                     break;
 107             }
 108             if (bi == NULL)
 109                 continue;
 110             ++found;
 111         }
 112
 113         *sock = BIO_socket(BIO_ADDRINFO_family(ai), BIO_ADDRINFO_socktype(ai),
 114                            BIO_ADDRINFO_protocol(ai), 0);
 115         if (*sock == INVALID_SOCKET) {
 116             /* Maybe the kernel doesn't support the socket family, even if
 117              * BIO_lookup() added it in the returned result...
 118              */
 119             continue;
 120         }
 121
 122         if (bi != NULL) {
 123             if (!BIO_bind(*sock, BIO_ADDRINFO_address(bi),
 124                           BIO_SOCK_REUSEADDR)) {
 125                 BIO_closesocket(*sock);
 126                 *sock = INVALID_SOCKET;
 127                 break;
 128             }
 129         }
 130
 131 #ifndef OPENSSL_NO_SCTP
 132         if (protocol == IPPROTO_SCTP) {
 133             /*
 134              * For SCTP we have to set various options on the socket prior to
 135              * connecting. This is done automatically by BIO_new_dgram_sctp().
 136              * We don't actually need the created BIO though so we free it again
 137              * immediately.
 138              */
 139             BIO *tmpbio = BIO_new_dgram_sctp(*sock, BIO_NOCLOSE);
 140
 141             if (tmpbio == NULL) {
 142                 ERR_print_errors(bio_err);
 143                 return 0;
 144             }
 145             BIO_free(tmpbio);
 146         }
 147 #endif
 148
 149         if (!BIO_connect(*sock, BIO_ADDRINFO_address(ai),
 150                          protocol == IPPROTO_TCP ? BIO_SOCK_NODELAY : 0)) {
 151             BIO_closesocket(*sock);
 152             *sock = INVALID_SOCKET;
 153             continue;
 154         }
 155
 156         /* Success, don't try any more addresses */
 157         break;
 158     }
 159
 160     if (*sock == INVALID_SOCKET) {
 161         if (bindaddr != NULL && !found) {
 162             BIO_printf(bio_err, "Can't bind %saddress for %s%s%s\n",
 163                        BIO_ADDRINFO_family(res) == AF_INET6 ? "IPv6 " :
 164                        BIO_ADDRINFO_family(res) == AF_INET ? "IPv4 " :
 165                        BIO_ADDRINFO_family(res) == AF_UNIX ? "unix " : "",
 166                        bindhost != NULL ? bindhost : "",
 167                        bindport != NULL ? ":" : "",
 168                        bindport != NULL ? bindport : "");
 169             ERR_clear_error();
 170             ret = 0;
 171         }
 172         ERR_print_errors(bio_err);
 173     } else {
 174         /* Remove any stale errors from previous connection attempts */
 175         ERR_clear_error();
 176         ret = 1;
 177     }
 178 out:
 179     if (bindaddr != NULL) {
 180         BIO_ADDRINFO_free (bindaddr);
 181     }
 182     BIO_ADDRINFO_free(res);
 183     return ret;
 184 }
 185
 186 /*
 187  * do_server - helper routine to perform a server operation
 188  * @accept_sock: pointer to storage of resulting socket.
 189  * @host: the host name or path (for AF_UNIX) to connect to.
 190  * @port: the port to connect to (ignored for AF_UNIX).
 191  * @family: desired socket family, may be AF_INET, AF_INET6, AF_UNIX or
 192  *  AF_UNSPEC
 193  * @type: socket type, must be SOCK_STREAM or SOCK_DGRAM
 194  * @cb: pointer to a function that receives the accepted socket and
 195  *  should perform the communication with the connecting client.
 196  * @context: pointer to memory that's passed verbatim to the cb function.
 197  * @naccept: number of times an incoming connect should be accepted.  If -1,
 198  *  unlimited number.
 199  *
 200  * This will create a socket and use it to listen to a host:port, or if
 201  * family == AF_UNIX, to the path found in host, then start accepting
 202  * incoming connections and run cb on the resulting socket.
 203  *
 204  * 0 on failure, something other on success.
 205  */
 206 int do_server(int *accept_sock, const char *host, const char *port,
 207               int family, int type, int protocol, do_server_cb cb,
 208               unsigned char *context, int naccept, BIO *bio_s_out)
 209 {
 210     int asock = 0;
 211     int sock;
 212     int i;
 213     BIO_ADDRINFO *res = NULL;
 214     const BIO_ADDRINFO *next;
 215     int sock_family, sock_type, sock_protocol, sock_port;
 216     const BIO_ADDR *sock_address;
 217     int sock_options = BIO_SOCK_REUSEADDR;
 218     int ret = 0;
 219
 220     if (BIO_sock_init() != 1)
 221         return 0;
 222
 223     if (!BIO_lookup_ex(host, port, BIO_LOOKUP_SERVER, family, type, protocol,
 224                        &res)) {
 225         ERR_print_errors(bio_err);
 226         return 0;
 227     }
 228
 229     /* Admittedly, these checks are quite paranoid, we should not get
 230      * anything in the BIO_ADDRINFO chain that we haven't asked for */
 231     OPENSSL_assert((family == AF_UNSPEC || family == BIO_ADDRINFO_family(res))
 232                    && (type == 0 || type == BIO_ADDRINFO_socktype(res))
 233                    && (protocol == 0 || protocol == BIO_ADDRINFO_protocol(res)));
 234
 235     sock_family = BIO_ADDRINFO_family(res);
 236     sock_type = BIO_ADDRINFO_socktype(res);
 237     sock_protocol = BIO_ADDRINFO_protocol(res);
 238     sock_address = BIO_ADDRINFO_address(res);
 239     next = BIO_ADDRINFO_next(res);
 240     if (sock_family == AF_INET6)
 241         sock_options |= BIO_SOCK_V6_ONLY;
 242     if (next != NULL
 243             && BIO_ADDRINFO_socktype(next) == sock_type
 244             && BIO_ADDRINFO_protocol(next) == sock_protocol) {
 245         if (sock_family == AF_INET
 246                 && BIO_ADDRINFO_family(next) == AF_INET6) {
 247             sock_family = AF_INET6;
 248             sock_address = BIO_ADDRINFO_address(next);
 249         } else if (sock_family == AF_INET6
 250                    && BIO_ADDRINFO_family(next) == AF_INET) {
 251             sock_options &= ~BIO_SOCK_V6_ONLY;
 252         }
 253     }
 254
 255     asock = BIO_socket(sock_family, sock_type, sock_protocol, 0);
 256     if (asock == INVALID_SOCKET
 257         || !BIO_listen(asock, sock_address, sock_options)) {
 258         BIO_ADDRINFO_free(res);
 259         ERR_print_errors(bio_err);
 260         if (asock != INVALID_SOCKET)
 261             BIO_closesocket(asock);
 262         goto end;
 263     }
 264
 265 #ifndef OPENSSL_NO_SCTP
 266     if (protocol == IPPROTO_SCTP) {
 267         /*
 268          * For SCTP we have to set various options on the socket prior to
 269          * accepting. This is done automatically by BIO_new_dgram_sctp().
 270          * We don't actually need the created BIO though so we free it again
 271          * immediately.
 272          */
 273         BIO *tmpbio = BIO_new_dgram_sctp(asock, BIO_NOCLOSE);
 274
 275         if (tmpbio == NULL) {
 276             BIO_closesocket(asock);
 277             ERR_print_errors(bio_err);
 278             goto end;
 279         }
 280         BIO_free(tmpbio);
 281     }
 282 #endif
 283
 284     sock_port = BIO_ADDR_rawport(sock_address);
 285
 286     BIO_ADDRINFO_free(res);
 287     res = NULL;
 288
 289     if (sock_port == 0) {
 290         /* dynamically allocated port, report which one */
 291         union BIO_sock_info_u info;
 292         char *hostname = NULL;
 293         char *service = NULL;
 294         int success = 0;
 295
 296         if ((info.addr = BIO_ADDR_new()) != NULL
 297             && BIO_sock_info(asock, BIO_SOCK_INFO_ADDRESS, &info)
 298             && (hostname = BIO_ADDR_hostname_string(info.addr, 1)) != NULL
 299             && (service = BIO_ADDR_service_string(info.addr, 1)) != NULL
 300             && BIO_printf(bio_s_out,
 301                           strchr(hostname, ':') == NULL
 302                           ? /* IPv4 */ "ACCEPT %s:%s\n"
 303                           : /* IPv6 */ "ACCEPT [%s]:%s\n",
 304                           hostname, service) > 0)
 305             success = 1;
 306
 307         (void)BIO_flush(bio_s_out);
 308         OPENSSL_free(hostname);
 309         OPENSSL_free(service);
 310         BIO_ADDR_free(info.addr);
 311         if (!success) {
 312             BIO_closesocket(asock);
 313             ERR_print_errors(bio_err);
 314             goto end;
 315         }
 316     } else {
 317         (void)BIO_printf(bio_s_out, "ACCEPT\n");
 318         (void)BIO_flush(bio_s_out);
 319     }
 320
 321     if (accept_sock != NULL)
 322         *accept_sock = asock;
 323     for (;;) {
 324         char sink[64];
 325         struct timeval timeout;
 326         fd_set readfds;
 327
 328         if (type == SOCK_STREAM) {
 329             BIO_ADDR_free(ourpeer);
 330             ourpeer = BIO_ADDR_new();
 331             if (ourpeer == NULL) {
 332                 BIO_closesocket(asock);
 333                 ERR_print_errors(bio_err);
 334                 goto end;
 335             }
 336             do {
 337                 sock = BIO_accept_ex(asock, ourpeer, 0);
 338             } while (sock < 0 && BIO_sock_should_retry(sock));
 339             if (sock < 0) {
 340                 ERR_print_errors(bio_err);
 341                 BIO_closesocket(asock);
 342                 break;
 343             }
 344             BIO_set_tcp_ndelay(sock, 1);
 345             i = (*cb)(sock, type, protocol, context);
 346
 347             /*
 348              * If we ended with an alert being sent, but still with data in the
 349              * network buffer to be read, then calling BIO_closesocket() will
 350              * result in a TCP-RST being sent. On some platforms (notably
 351              * Windows) then this will result in the peer immediately abandoning
 352              * the connection including any buffered alert data before it has
 353              * had a chance to be read. Shutting down the sending side first,
 354              * and then closing the socket sends TCP-FIN first followed by
 355              * TCP-RST. This seems to allow the peer to read the alert data.
 356              */
 357             shutdown(sock, 1); /* SHUT_WR */
 358             /*
 359              * We just said we have nothing else to say, but it doesn't mean
 360              * that the other side has nothing. It's even recommended to
 361              * consume incoming data. [In testing context this ensures that
 362              * alerts are passed on...]
 363              */
 364             timeout.tv_sec = 0;
 365             timeout.tv_usec = 500000;  /* some extreme round-trip */
 366             do {
 367                 FD_ZERO(&readfds);
 368                 openssl_fdset(sock, &readfds);
 369             } while (select(sock + 1, &readfds, NULL, NULL, &timeout) > 0
 370                      && readsocket(sock, sink, sizeof(sink)) > 0);
 371
 372             BIO_closesocket(sock);
 373         } else {
 374             i = (*cb)(asock, type, protocol, context);
 375         }
 376
 377         if (naccept != -1)
 378             naccept--;
 379         if (i < 0 || naccept == 0) {
 380             BIO_closesocket(asock);
 381             ret = i;
 382             break;
 383         }
 384     }
 385  end:
 386 # ifdef AF_UNIX
 387     if (family == AF_UNIX)
 388         unlink(host);
 389 # endif
 390     BIO_ADDR_free(ourpeer);
 391     ourpeer = NULL;
 392     return ret;
 393 }
 394
 395 #endif  /* OPENSSL_NO_SOCK */