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 - 2017 Steffen (Daode) Nurpmeso <steffen@sdaoden.eu>.
   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_XSSL
  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_XSSL
 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_XSSL
 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_XSSL
 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(n_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    n_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 (n_poption & n_PO_VERB)
 265       n_err(_("Resolving host %s:%s ... "), urlp->url_host.s, serv);
 266
 267    /* Signal handling (in respect to __sopen_sig dealing) is heavy, but no
 268     * healing until v15.0 and i want to end up with that functionality */
 269    hold_sigs();
 270    __sopen_sig = 0;
 271    ohup = safe_signal(SIGHUP, &__sopen_onsig);
 272    oint = safe_signal(SIGINT, &__sopen_onsig);
 273    if (sigsetjmp(__sopen_actjmp, 0)) {
 274 jpseudo_jump:
 275       n_err("%s\n",
 276          (__sopen_sig == SIGHUP ? _("Hangup") : _("Interrupted")));
 277       if (sofd >= 0) {
 278          close(sofd);
 279          sofd = -1;
 280       }
 281       goto jjumped;
 282    }
 283    rele_sigs();
 284
 285 # ifdef HAVE_GETADDRINFO
 286    for (;;) {
 287       memset(&hints, 0, sizeof hints);
 288       hints.ai_socktype = SOCK_STREAM;
 289       __sopen_sig = -1;
 290       errval = getaddrinfo(urlp->url_host.s, serv, &hints, &res0);
 291       if (__sopen_sig != -1) {
 292          __sopen_sig = SIGINT;
 293          goto jpseudo_jump;
 294       }
 295       __sopen_sig = 0;
 296       if (errval == 0)
 297          break;
 298
 299       if (n_poption & n_PO_VERB)
 300          n_err(_("failed\n"));
 301       n_err(_("Lookup of %s:%s failed: %s\n"),
 302          urlp->url_host.s, serv, gai_strerror(errval));
 303
 304       /* Error seems to depend on how "smart" the /etc/service code is: is it
 305        * "able" to state whether the service as such is NONAME or does it only
 306        * check for the given ai_socktype.. */
 307       if (errval == EAI_NONAME || errval == EAI_SERVICE) {
 308          if (serv == urlp->url_proto &&
 309                (serv = n_servbyname(urlp->url_proto, NULL)) != NULL &&
 310                *serv != '\0') {
 311             n_err(_("  Trying standard protocol port %s\n"), serv);
 312             n_err(_("  If that succeeds consider including the "
 313                "port in the URL!\n"));
 314             continue;
 315          }
 316          if (serv != urlp->url_port)
 317             n_err(_("  Including a port number in the URL may "
 318                "circumvent this problem\n"));
 319       }
 320       assert(sofd == -1);
 321       errval = 0;
 322       goto jjumped;
 323    }
 324    if (n_poption & n_PO_VERB)
 325       n_err(_("done\n"));
 326
 327    for (res = res0; res != NULL && sofd < 0; res = res->ai_next) {
 328       if (n_poption & n_PO_VERB) {
 329          if (getnameinfo(res->ai_addr, res->ai_addrlen, hbuf, sizeof hbuf,
 330                NULL, 0, NI_NUMERICHOST))
 331             memcpy(hbuf, "unknown host", sizeof("unknown host"));
 332          n_err(_("%sConnecting to %s:%s ... "),
 333                (res == res0 ? n_empty : "\n"), hbuf, serv);
 334       }
 335
 336       sofd = socket(res->ai_family, res->ai_socktype, res->ai_protocol);
 337       if (sofd >= 0) {
 338 #  ifdef HAVE_SO_SNDTIMEO
 339          (void)setsockopt(sofd, SOL_SOCKET, SO_SNDTIMEO, &tv, sizeof tv);
 340 #  endif
 341          if (connect(sofd, res->ai_addr, res->ai_addrlen)) {
 342             errval = errno;
 343             close(sofd);
 344             sofd = -1;
 345          }
 346       }
 347    }
 348
 349 jjumped:
 350    if (res0 != NULL) {
 351       freeaddrinfo(res0);
 352       res0 = NULL;
 353    }
 354
 355 # else /* HAVE_GETADDRINFO */
 356    if (serv == urlp->url_proto) {
 357       if ((ep = getservbyname(n_UNCONST(serv), "tcp")) != NULL)
 358          urlp->url_portno = ntohs(ep->s_port);
 359       else {
 360          if (n_poption & n_PO_VERB)
 361             n_err(_("failed\n"));
 362          if ((serv = n_servbyname(urlp->url_proto, &urlp->url_portno)) != NULL)
 363             n_err(_("  Unknown service: %s\n"), urlp->url_proto);
 364             n_err(_("  Trying standard protocol port %s\n"), serv);
 365             n_err(_("  If that succeeds consider including the "
 366                "port in the URL!\n"));
 367          else {
 368             n_err(_("  Unknown service: %s\n"), urlp->url_proto);
 369             n_err(_("  Including a port number in the URL may "
 370                "circumvent this problem\n"));
 371             assert(sofd == -1 && errval == 0);
 372             goto jjumped;
 373          }
 374       }
 375    }
 376
 377    __sopen_sig = -1;
 378    hp = gethostbyname(urlp->url_host.s);
 379    if (__sopen_sig != -1) {
 380       __sopen_sig = SIGINT;
 381       goto jpseudo_jump;
 382    }
 383    __sopen_sig = 0;
 384
 385    if (hp == NULL) {
 386       char const *emsg;
 387
 388       if (n_poption & n_PO_VERB)
 389          n_err(_("failed\n"));
 390       switch (h_errno) {
 391       case HOST_NOT_FOUND: emsg = N_("host not found"); break;
 392       default:
 393       case TRY_AGAIN:      emsg = N_("(maybe) try again later"); break;
 394       case NO_RECOVERY:    emsg = N_("non-recoverable server error"); break;
 395       case NO_DATA:        emsg = N_("valid name without IP address"); break;
 396       }
 397       n_err(_("Lookup of %s:%s failed: %s\n"),
 398          urlp->url_host.s, serv, V_(emsg));
 399       goto jjumped;
 400    } else if (n_poption & n_PO_VERB)
 401       n_err(_("done\n"));
 402
 403    pptr = (struct in_addr**)hp->h_addr_list;
 404    if ((sofd = socket(AF_INET, SOCK_STREAM, 0)) == -1) {
 405       n_perr(_("could not create socket"), 0);
 406       assert(sofd == -1 && errval == 0);
 407       goto jjumped;
 408    }
 409
 410    memset(&servaddr, 0, sizeof servaddr);
 411    servaddr.sin_family = AF_INET;
 412    servaddr.sin_port = htons(urlp->url_portno);
 413    memcpy(&servaddr.sin_addr, *pptr, sizeof(struct in_addr));
 414    if (n_poption & n_PO_VERB)
 415       n_err(_("%sConnecting to %s:%d ... "),
 416          n_empty, inet_ntoa(**pptr), (int)urlp->url_portno);
 417 #  ifdef HAVE_SO_SNDTIMEO
 418    (void)setsockopt(sofd, SOL_SOCKET, SO_SNDTIMEO, &tv, sizeof tv);
 419 #  endif
 420    if (connect(sofd, (struct sockaddr*)&servaddr, sizeof servaddr)) {
 421       errval = errno;
 422       close(sofd);
 423       sofd = -1;
 424    }
 425 jjumped:
 426 # endif /* !HAVE_GETADDRINFO */
 427
 428    hold_sigs();
 429    safe_signal(SIGINT, oint);
 430    safe_signal(SIGHUP, ohup);
 431    rele_sigs();
 432
 433    if (sofd < 0) {
 434       if (errval != 0) {
 435          errno = errval;
 436          n_perr(_("Could not connect"), 0);
 437       }
 438       goto jleave;
 439    }
 440
 441    if (n_poption & n_PO_VERB)
 442       n_err(_("connected.\n"));
 443
 444    /* And the regular timeouts XXX configurable */
 445 # ifdef HAVE_SO_SNDTIMEO
 446    tv.tv_sec = 42;
 447    tv.tv_usec = 0;
 448    (void)setsockopt(sofd, SOL_SOCKET, SO_SNDTIMEO, &tv, sizeof tv);
 449    (void)setsockopt(sofd, SOL_SOCKET, SO_RCVTIMEO, &tv, sizeof tv);
 450 # endif
 451 # ifdef HAVE_SO_LINGER
 452    li.l_onoff = 1;
 453    li.l_linger = 42;
 454    (void)setsockopt(sofd, SOL_SOCKET, SO_LINGER, &li, sizeof li);
 455 # endif
 456
 457    memset(sp, 0, sizeof *sp);
 458    sp->s_fd = sofd;
 459
 460    /* SSL/TLS upgrade? */
 461 # ifdef HAVE_SSL
 462    if (urlp->url_needs_tls) {
 463       hold_sigs();
 464       ohup = safe_signal(SIGHUP, &__sopen_onsig);
 465       oint = safe_signal(SIGINT, &__sopen_onsig);
 466       if (sigsetjmp(__sopen_actjmp, 0)) {
 467          n_err(_("%s during SSL/TLS handshake\n"),
 468             (__sopen_sig == SIGHUP ? _("Hangup") : _("Interrupted")));
 469          goto jsclose;
 470       }
 471       rele_sigs();
 472
 473       if (ssl_open(urlp, sp) != OKAY) {
 474 jsclose:
 475          sclose(sp);
 476          sofd = -1;
 477       }
 478
 479       hold_sigs();
 480       safe_signal(SIGINT, oint);
 481       safe_signal(SIGHUP, ohup);
 482       rele_sigs();
 483    }
 484 # endif /* HAVE_SSL */
 485
 486 jleave:
 487    /* May need to bounce the signal to the lex.c trampoline (or wherever) */
 488    if (__sopen_sig != 0) {
 489       sigset_t cset;
 490       sigemptyset(&cset);
 491       sigaddset(&cset, __sopen_sig);
 492       sigprocmask(SIG_UNBLOCK, &cset, NULL);
 493       n_raise(__sopen_sig);
 494    }
 495    NYD_LEAVE;
 496    return (sofd >= 0);
 497 }
 498
 499 FL int
 500 (sgetline)(char **line, size_t *linesize, size_t *linelen, struct sock *sp
 501    n_MEMORY_DEBUG_ARGS)
 502 {
 503    int rv;
 504    size_t lsize;
 505    char *lp_base, *lp;
 506    NYD2_ENTER;
 507
 508    lsize = *linesize;
 509    lp_base = *line;
 510    lp = lp_base;
 511
 512    if (sp->s_rsz < 0) {
 513       sclose(sp);
 514       rv = sp->s_rsz;
 515       goto jleave;
 516    }
 517
 518    do {
 519       if (lp_base == NULL || PTRCMP(lp, >, lp_base + lsize - 128)) {
 520          size_t diff = PTR2SIZE(lp - lp_base);
 521          *linesize = (lsize += 256); /* XXX magic */
 522          *line = lp_base = (n_realloc)(lp_base, lsize n_MEMORY_DEBUG_ARGSCALL);
 523          lp = lp_base + diff;
 524       }
 525
 526       if (sp->s_rbufptr == NULL ||
 527             PTRCMP(sp->s_rbufptr, >=, sp->s_rbuf + sp->s_rsz)) {
 528 # ifdef HAVE_XSSL
 529          if (sp->s_use_ssl) {
 530 jssl_retry:
 531             sp->s_rsz = SSL_read(sp->s_ssl, sp->s_rbuf, sizeof sp->s_rbuf);
 532             if (sp->s_rsz <= 0) {
 533                if (sp->s_rsz < 0) {
 534                   char o[512];
 535                   switch(SSL_get_error(sp->s_ssl, sp->s_rsz)) {
 536                   case SSL_ERROR_WANT_READ:
 537                   case SSL_ERROR_WANT_WRITE:
 538                      goto jssl_retry;
 539                   }
 540                   snprintf(o, sizeof o, "%s",
 541                      (sp->s_desc ?  sp->s_desc : "socket"));
 542                   ssl_gen_err("%s", o);
 543                }
 544                break;
 545             }
 546          } else
 547 # endif
 548          {
 549 jagain:
 550             sp->s_rsz = read(sp->s_fd, sp->s_rbuf, sizeof sp->s_rbuf);
 551             if (sp->s_rsz <= 0) {
 552                if (sp->s_rsz < 0) {
 553                   char o[512];
 554                   if (errno == EINTR)
 555                      goto jagain;
 556                   snprintf(o, sizeof o, "%s",
 557                      (sp->s_desc ?  sp->s_desc : "socket"));
 558                   n_perr(o, 0);
 559                }
 560                break;
 561             }
 562          }
 563          sp->s_rbufptr = sp->s_rbuf;
 564       }
 565    } while ((*lp++ = *sp->s_rbufptr++) != '\n');
 566    *lp = '\0';
 567    lsize = PTR2SIZE(lp - lp_base);
 568
 569    if (linelen)
 570       *linelen = lsize;
 571    rv = (int)lsize;
 572 jleave:
 573    NYD2_LEAVE;
 574    return rv;
 575 }
 576 #endif /* HAVE_SOCKETS */
 577
 578 /* s-it-mode */