socket.c

   1 /*@ S-nail - a mail user agent derived from Berkeley Mail.
   2  *@ Socket operations.
   3  *
   4  * Copyright (c) 2000-2004 Gunnar Ritter, Freiburg i. Br., Germany.
   5  * Copyright (c) 2012 - 2015 Steffen (Daode) Nurpmeso <sdaoden@users.sf.net>.
   6  */
   7 /*
   8  * Redistribution and use in source and binary forms, with or without
   9  * modification, are permitted provided that the following conditions
  10  * are met:
  11  * 1. Redistributions of source code must retain the above copyright
  12  *    notice, this list of conditions and the following disclaimer.
  13  * 2. Redistributions in binary form must reproduce the above copyright
  14  *    notice, this list of conditions and the following disclaimer in the
  15  *    documentation and/or other materials provided with the distribution.
  16  * 3. Neither the name of the University nor the names of its contributors
  17  *    may be used to endorse or promote products derived from this software
  18  *    without specific prior written permission.
  19  *
  20  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  30  * SUCH DAMAGE.
  31  */
  32 #undef n_FILE
  33 #define n_FILE socket
  34
  35 #ifndef HAVE_AMALGAMATION
  36 # include "nail.h"
  37 #endif
  38
  39 EMPTY_FILE()
  40 #ifdef HAVE_SOCKETS
  41 #include <sys/socket.h>
  42
  43 #include <netdb.h>
  44
  45 #include <netinet/in.h>
  46
  47 #ifdef HAVE_ARPA_INET_H
  48 # include <arpa/inet.h>
  49 #endif
  50
  51 #ifdef HAVE_OPENSSL
  52 # include <openssl/err.h>
  53 # include <openssl/rand.h>
  54 # include <openssl/ssl.h>
  55 # include <openssl/x509v3.h>
  56 # include <openssl/x509.h>
  57 #endif
  58
  59 /* Write to socket fd, restarting on EINTR, unless anything is written */
  60 static long a_sock_xwrite(int fd, char const *data, size_t sz);
  61
  62 static long
  63 a_sock_xwrite(int fd, char const *data, size_t sz)
  64 {
  65    long rv = -1, wo;
  66    size_t wt = 0;
  67    NYD_ENTER;
  68
  69    do {
  70       if ((wo = write(fd, data + wt, sz - wt)) < 0) {
  71          if (errno == EINTR)
  72             continue;
  73          else
  74             goto jleave;
  75       }
  76       wt += wo;
  77    } while (wt < sz);
  78    rv = (long)sz;
  79 jleave:
  80    NYD_LEAVE;
  81    return rv;
  82 }
  83
  84 FL int
  85 sclose(struct sock *sp)
  86 {
  87    int i;
  88    NYD_ENTER;
  89
  90    i = sp->s_fd;
  91    sp->s_fd = -1;
  92    /* TODO NOTE: we MUST NOT close the descriptor 0 here...
  93     * TODO of course this should be handled in a VMAILFS->open() .s_fd=-1,
  94     * TODO but unfortunately it isn't yet */
  95    if (i <= 0)
  96       i = 0;
  97    else {
  98       if (sp->s_onclose != NULL)
  99          (*sp->s_onclose)();
 100       if (sp->s_wbuf != NULL)
 101          free(sp->s_wbuf);
 102 # ifdef HAVE_OPENSSL
 103       if (sp->s_use_ssl) {
 104          void *s_ssl = sp->s_ssl;
 105
 106          sp->s_ssl = NULL;
 107          sp->s_use_ssl = 0;
 108          while (!SSL_shutdown(s_ssl)) /* XXX proper error handling;signals! */
 109             ;
 110          SSL_free(s_ssl);
 111       }
 112 # endif
 113       i = close(i);
 114    }
 115    NYD_LEAVE;
 116    return i;
 117 }
 118
 119 FL enum okay
 120 swrite(struct sock *sp, char const *data)
 121 {
 122    enum okay rv;
 123    NYD2_ENTER;
 124
 125    rv = swrite1(sp, data, strlen(data), 0);
 126    NYD2_LEAVE;
 127    return rv;
 128 }
 129
 130 FL enum okay
 131 swrite1(struct sock *sp, char const *data, int sz, int use_buffer)
 132 {
 133    enum okay rv = STOP;
 134    int x;
 135    NYD2_ENTER;
 136
 137    if (use_buffer > 0) {
 138       int di;
 139
 140       if (sp->s_wbuf == NULL) {
 141          sp->s_wbufsize = 4096;
 142          sp->s_wbuf = smalloc(sp->s_wbufsize);
 143          sp->s_wbufpos = 0;
 144       }
 145       while (sp->s_wbufpos + sz > sp->s_wbufsize) {
 146          di = sp->s_wbufsize - sp->s_wbufpos;
 147          sz -= di;
 148          if (sp->s_wbufpos > 0) {
 149             memcpy(sp->s_wbuf + sp->s_wbufpos, data, di);
 150             rv = swrite1(sp, sp->s_wbuf, sp->s_wbufsize, -1);
 151          } else
 152             rv = swrite1(sp, data, sp->s_wbufsize, -1);
 153          if (rv != OKAY)
 154             goto jleave;
 155          data += di;
 156          sp->s_wbufpos = 0;
 157       }
 158       if (sz == sp->s_wbufsize) {
 159          rv = swrite1(sp, data, sp->s_wbufsize, -1);
 160          if (rv != OKAY)
 161             goto jleave;
 162       } else if (sz) {
 163          memcpy(sp->s_wbuf+ sp->s_wbufpos, data, sz);
 164          sp->s_wbufpos += sz;
 165       }
 166       rv = OKAY;
 167       goto jleave;
 168    } else if (use_buffer == 0 && sp->s_wbuf != NULL && sp->s_wbufpos > 0) {
 169       x = sp->s_wbufpos;
 170       sp->s_wbufpos = 0;
 171       if ((rv = swrite1(sp, sp->s_wbuf, x, -1)) != OKAY)
 172          goto jleave;
 173    }
 174    if (sz == 0) {
 175       rv = OKAY;
 176       goto jleave;
 177    }
 178
 179 # ifdef HAVE_OPENSSL
 180    if (sp->s_use_ssl) {
 181 jssl_retry:
 182       x = SSL_write(sp->s_ssl, data, sz);
 183       if (x < 0) {
 184          switch (SSL_get_error(sp->s_ssl, x)) {
 185          case SSL_ERROR_WANT_READ:
 186          case SSL_ERROR_WANT_WRITE:
 187             goto jssl_retry;
 188          }
 189       }
 190    } else
 191 # endif
 192    {
 193       x = a_sock_xwrite(sp->s_fd, data, sz);
 194    }
 195    if (x != sz) {
 196       char o[512];
 197       snprintf(o, sizeof o, "%s write error",
 198          (sp->s_desc ? sp->s_desc : "socket"));
 199 # ifdef HAVE_OPENSSL
 200       if (sp->s_use_ssl)
 201          ssl_gen_err("%s", o);
 202       else
 203 # endif
 204          n_perr(o, 0);
 205       if (x < 0)
 206          sclose(sp);
 207       rv = STOP;
 208       goto jleave;
 209    }
 210    rv = OKAY;
 211 jleave:
 212    NYD2_LEAVE;
 213    return rv;
 214 }
 215
 216 static sigjmp_buf __sopen_actjmp; /* TODO someday, we won't need it no more */
 217 static int        __sopen_sig; /* TODO someday, we won't need it no more */
 218 static void
 219 __sopen_onsig(int sig) /* TODO someday, we won't need it no more */
 220 {
 221    NYD_X; /* Signal handler */
 222    if (__sopen_sig == -1) {
 223       fprintf(stderr, _("\nInterrupting this operation may turn "
 224          "the DNS resolver unusable\n"));
 225       __sopen_sig = 0;
 226    } else {
 227       __sopen_sig = sig;
 228       siglongjmp(__sopen_actjmp, 1);
 229    }
 230 }
 231
 232 FL bool_t
 233 sopen(struct sock *sp, struct url *urlp) /* TODO sighandling; refactor */
 234 {
 235 # ifdef HAVE_SO_SNDTIMEO
 236    struct timeval tv;
 237 # endif
 238 # ifdef HAVE_SO_LINGER
 239    struct linger li;
 240 # endif
 241 # ifdef HAVE_GETADDRINFO
 242    char hbuf[NI_MAXHOST];
 243    struct addrinfo hints, *res0 = NULL, *res;
 244 # else
 245    struct sockaddr_in servaddr;
 246    struct in_addr **pptr;
 247    struct hostent *hp;
 248    struct servent *ep;
 249 # endif
 250    sighandler_type volatile ohup, oint;
 251    char const * volatile serv;
 252    int volatile sofd = -1, errval;
 253    NYD_ENTER;
 254
 255    UNINIT(errval, 0);
 256
 257    /* Connect timeouts after 30 seconds XXX configurable */
 258 # ifdef HAVE_SO_SNDTIMEO
 259    tv.tv_sec = 30;
 260    tv.tv_usec = 0;
 261 # endif
 262    serv = (urlp->url_port != NULL) ? urlp->url_port : urlp->url_proto;
 263
 264    if (options & OPT_VERB)
 265       n_err(_("Resolving host \"%s:%s\" ... "),
 266          urlp->url_host.s, serv);
 267
 268    /* Signal handling (in respect to __sopen_sig dealing) is heavy, but no
 269     * healing until v15.0 and i want to end up with that functionality */
 270    hold_sigs();
 271    __sopen_sig = 0;
 272    ohup = safe_signal(SIGHUP, &__sopen_onsig);
 273    oint = safe_signal(SIGINT, &__sopen_onsig);
 274    if (sigsetjmp(__sopen_actjmp, 0)) {
 275 jpseudo_jump:
 276       n_err("%s\n",
 277          (__sopen_sig == SIGHUP ? _("Hangup") : _("Interrupted")));
 278       if (sofd >= 0) {
 279          close(sofd);
 280          sofd = -1;
 281       }
 282       goto jjumped;
 283    }
 284    rele_sigs();
 285
 286 # ifdef HAVE_GETADDRINFO
 287    for (;;) {
 288       memset(&hints, 0, sizeof hints);
 289       hints.ai_socktype = SOCK_STREAM;
 290       __sopen_sig = -1;
 291       errval = getaddrinfo(urlp->url_host.s, serv, &hints, &res0);
 292       if (__sopen_sig != -1) {
 293          __sopen_sig = SIGINT;
 294          goto jpseudo_jump;
 295       }
 296       __sopen_sig = 0;
 297       if (errval == 0)
 298          break;
 299
 300       if (options & OPT_VERB)
 301          n_err(_("failed\n"));
 302       n_err(_("Lookup of \"%s:%s\" failed: %s\n"),
 303          urlp->url_host.s, serv, gai_strerror(errval));
 304
 305       /* Error seems to depend on how "smart" the /etc/service code is: is it
 306        * "able" to state wether the service as such is NONAME or does it only
 307        * check for the given ai_socktype.. */
 308       if (errval == EAI_NONAME || errval == EAI_SERVICE) {
 309          if (serv == urlp->url_proto &&
 310                (serv = n_servbyname(urlp->url_proto, NULL)) != NULL &&
 311                *serv != '\0') {
 312             n_err(_("  Trying standard protocol port \"%s\"\n"), serv);
 313             n_err(_("  If that succeeds consider including the "
 314                "port in the URL!\n"));
 315             continue;
 316          }
 317          if (serv != urlp->url_port)
 318             n_err(_("  Including a port number in the URL may "
 319                "circumvent this problem\n"));
 320       }
 321       assert(sofd == -1);
 322       errval = 0;
 323       goto jjumped;
 324    }
 325    if (options & OPT_VERB)
 326       n_err(_("done\n"));
 327
 328    for (res = res0; res != NULL && sofd < 0; res = res->ai_next) {
 329       if (options & OPT_VERB) {
 330          if (getnameinfo(res->ai_addr, res->ai_addrlen, hbuf, sizeof hbuf,
 331                NULL, 0, NI_NUMERICHOST))
 332             memcpy(hbuf, "unknown host", sizeof("unknown host"));
 333          n_err(_("%sConnecting to \"%s:%s\" ..."),
 334                (res == res0 ? "" : "\n"), hbuf, serv);
 335       }
 336
 337       sofd = socket(res->ai_family, res->ai_socktype, res->ai_protocol);
 338       if (sofd >= 0) {
 339 #  ifdef HAVE_SO_SNDTIMEO
 340          (void)setsockopt(sofd, SOL_SOCKET, SO_SNDTIMEO, &tv, sizeof tv);
 341 #  endif
 342          if (connect(sofd, res->ai_addr, res->ai_addrlen)) {
 343             errval = errno;
 344             close(sofd);
 345             sofd = -1;
 346          }
 347       }
 348    }
 349
 350 jjumped:
 351    if (res0 != NULL) {
 352       freeaddrinfo(res0);
 353       res0 = NULL;
 354    }
 355
 356 # else /* HAVE_GETADDRINFO */
 357    if (serv == urlp->url_proto) {
 358       if ((ep = getservbyname(UNCONST(serv), "tcp")) != NULL)
 359          urlp->url_portno = ntohs(ep->s_port);
 360       else {
 361          if (options & OPT_VERB)
 362             n_err(_("failed\n"));
 363          if ((serv = n_servbyname(urlp->url_proto, &urlp->url_portno)) != NULL)
 364             n_err(_("  Unknown service: \"%s\"\n"), urlp->url_proto);
 365             n_err(_("  Trying standard protocol port \"%s\"\n"), serv);
 366             n_err(_("  If that succeeds consider including the "
 367                "port in the URL!\n"));
 368          else {
 369             n_err(_("  Unknown service: \"%s\"\n"), urlp->url_proto);
 370             n_err(_("  Including a port number in the URL may "
 371                "circumvent this problem\n"));
 372             assert(sofd == -1 && errval == 0);
 373             goto jjumped;
 374          }
 375       }
 376    }
 377
 378    __sopen_sig = -1;
 379    hp = gethostbyname(urlp->url_host.s);
 380    if (__sopen_sig != -1) {
 381       __sopen_sig = SIGINT;
 382       goto jpseudo_jump;
 383    }
 384    __sopen_sig = 0;
 385
 386    if (hp == NULL) {
 387       char const *emsg;
 388
 389       if (options & OPT_VERB)
 390          n_err(_("failed\n"));
 391       switch (h_errno) {
 392       case HOST_NOT_FOUND: emsg = N_("host not found"); break;
 393       default:
 394       case TRY_AGAIN:      emsg = N_("(maybe) try again later"); break;
 395       case NO_RECOVERY:    emsg = N_("non-recoverable server error"); break;
 396       case NO_DATA:        emsg = N_("valid name without IP address"); break;
 397       }
 398       n_err(_("Lookup of \"%s:%s\" failed: %s\n"),
 399          urlp->url_host.s, serv, V_(emsg));
 400       goto jjumped;
 401    } else if (options & OPT_VERB)
 402       n_err(_("done\n"));
 403
 404    pptr = (struct in_addr**)hp->h_addr_list;
 405    if ((sofd = socket(AF_INET, SOCK_STREAM, 0)) == -1) {
 406       n_perr(_("could not create socket"), 0);
 407       assert(sofd == -1 && errval == 0);
 408       goto jjumped;
 409    }
 410
 411    memset(&servaddr, 0, sizeof servaddr);
 412    servaddr.sin_family = AF_INET;
 413    servaddr.sin_port = htons(urlp->url_portno);
 414    memcpy(&servaddr.sin_addr, *pptr, sizeof(struct in_addr));
 415    if (options & OPT_VERB)
 416       n_err(_("%sConnecting to \"%s:%d\" ... "),
 417          "", inet_ntoa(**pptr), (int)urlp->url_portno);
 418 #  ifdef HAVE_SO_SNDTIMEO
 419    (void)setsockopt(sofd, SOL_SOCKET, SO_SNDTIMEO, &tv, sizeof tv);
 420 #  endif
 421    if (connect(sofd, (struct sockaddr*)&servaddr, sizeof servaddr)) {
 422       errval = errno;
 423       close(sofd);
 424       sofd = -1;
 425    }
 426 jjumped:
 427 # endif /* !HAVE_GETADDRINFO */
 428
 429    hold_sigs();
 430    safe_signal(SIGINT, oint);
 431    safe_signal(SIGHUP, ohup);
 432    rele_sigs();
 433
 434    if (sofd < 0) {
 435       if (errval != 0) {
 436          errno = errval;
 437          n_perr(_("Could not connect"), 0);
 438       }
 439       goto jleave;
 440    }
 441
 442    if (options & OPT_VERB)
 443       n_err(_("connected.\n"));
 444
 445    /* And the regular timeouts XXX configurable */
 446 # ifdef HAVE_SO_SNDTIMEO
 447    tv.tv_sec = 42;
 448    tv.tv_usec = 0;
 449    (void)setsockopt(sofd, SOL_SOCKET, SO_SNDTIMEO, &tv, sizeof tv);
 450    (void)setsockopt(sofd, SOL_SOCKET, SO_RCVTIMEO, &tv, sizeof tv);
 451 # endif
 452 # ifdef HAVE_SO_LINGER
 453    li.l_onoff = 1;
 454    li.l_linger = 42;
 455    (void)setsockopt(sofd, SOL_SOCKET, SO_LINGER, &li, sizeof li);
 456 # endif
 457
 458    memset(sp, 0, sizeof *sp);
 459    sp->s_fd = sofd;
 460
 461    /* SSL/TLS upgrade? */
 462 # ifdef HAVE_SSL
 463    if (urlp->url_needs_tls) {
 464       hold_sigs();
 465       ohup = safe_signal(SIGHUP, &__sopen_onsig);
 466       oint = safe_signal(SIGINT, &__sopen_onsig);
 467       if (sigsetjmp(__sopen_actjmp, 0)) {
 468          n_err(_("%s during SSL/TLS handshake\n"),
 469             (__sopen_sig == SIGHUP ? _("Hangup") : _("Interrupted")));
 470          goto jsclose;
 471       }
 472       rele_sigs();
 473
 474       if (ssl_open(urlp, sp) != OKAY) {
 475 jsclose:
 476          sclose(sp);
 477          sofd = -1;
 478       }
 479
 480       hold_sigs();
 481       safe_signal(SIGINT, oint);
 482       safe_signal(SIGHUP, ohup);
 483       rele_sigs();
 484    }
 485 # endif /* HAVE_SSL */
 486
 487 jleave:
 488    /* May need to bounce the signal to the lex.c trampoline (or wherever) */
 489    if (__sopen_sig != 0) {
 490       sigset_t cset;
 491       sigemptyset(&cset);
 492       sigaddset(&cset, __sopen_sig);
 493       sigprocmask(SIG_UNBLOCK, &cset, NULL);
 494       n_raise(__sopen_sig);
 495    }
 496    NYD_LEAVE;
 497    return (sofd >= 0);
 498 }
 499
 500 FL int
 501 (sgetline)(char **line, size_t *linesize, size_t *linelen, struct sock *sp
 502    SMALLOC_DEBUG_ARGS)
 503 {
 504    int rv;
 505    size_t lsize;
 506    char *lp_base, *lp;
 507    NYD2_ENTER;
 508
 509    lsize = *linesize;
 510    lp_base = *line;
 511    lp = lp_base;
 512
 513    if (sp->s_rsz < 0) {
 514       sclose(sp);
 515       rv = sp->s_rsz;
 516       goto jleave;
 517    }
 518
 519    do {
 520       if (lp_base == NULL || PTRCMP(lp, >, lp_base + lsize - 128)) {
 521          size_t diff = PTR2SIZE(lp - lp_base);
 522          *linesize = (lsize += 256); /* XXX magic */
 523          *line = lp_base = (srealloc)(lp_base, lsize SMALLOC_DEBUG_ARGSCALL);
 524          lp = lp_base + diff;
 525       }
 526
 527       if (sp->s_rbufptr == NULL ||
 528             PTRCMP(sp->s_rbufptr, >=, sp->s_rbuf + sp->s_rsz)) {
 529 # ifdef HAVE_OPENSSL
 530          if (sp->s_use_ssl) {
 531 jssl_retry:
 532             sp->s_rsz = SSL_read(sp->s_ssl, sp->s_rbuf, sizeof sp->s_rbuf);
 533             if (sp->s_rsz <= 0) {
 534                if (sp->s_rsz < 0) {
 535                   char o[512];
 536                   switch(SSL_get_error(sp->s_ssl, sp->s_rsz)) {
 537                   case SSL_ERROR_WANT_READ:
 538                   case SSL_ERROR_WANT_WRITE:
 539                      goto jssl_retry;
 540                   }
 541                   snprintf(o, sizeof o, "%s",
 542                      (sp->s_desc ?  sp->s_desc : "socket"));
 543                   ssl_gen_err("%s", o);
 544                }
 545                break;
 546             }
 547          } else
 548 # endif
 549          {
 550 jagain:
 551             sp->s_rsz = read(sp->s_fd, sp->s_rbuf, sizeof sp->s_rbuf);
 552             if (sp->s_rsz <= 0) {
 553                if (sp->s_rsz < 0) {
 554                   char o[512];
 555                   if (errno == EINTR)
 556                      goto jagain;
 557                   snprintf(o, sizeof o, "%s",
 558                      (sp->s_desc ?  sp->s_desc : "socket"));
 559                   n_perr(o, 0);
 560                }
 561                break;
 562             }
 563          }
 564          sp->s_rbufptr = sp->s_rbuf;
 565       }
 566    } while ((*lp++ = *sp->s_rbufptr++) != '\n');
 567    *lp = '\0';
 568    lsize = PTR2SIZE(lp - lp_base);
 569
 570    if (linelen)
 571       *linelen = lsize;
 572    rv = (int)lsize;
 573 jleave:
 574    NYD2_LEAVE;
 575    return rv;
 576 }
 577 #endif /* HAVE_SOCKETS */
 578
 579 /* s-it-mode */