libexec/dma/net.c

   1 /*
   2  * Copyright (c) 2008 The DragonFly Project.  All rights reserved.
   3  *
   4  * This code is derived from software contributed to The DragonFly Project
   5  * by Matthias Schmidt <matthias@dragonflybsd.org>, University of Marburg,
   6  * Germany.
   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  *
  12  * 1. Redistributions of source code must retain the above copyright
  13  *    notice, this list of conditions and the following disclaimer.
  14  * 2. Redistributions in binary form must reproduce the above copyright
  15  *    notice, this list of conditions and the following disclaimer in
  16  *    the documentation and/or other materials provided with the
  17  *    distribution.
  18  * 3. Neither the name of The DragonFly Project nor the names of its
  19  *    contributors may be used to endorse or promote products derived
  20  *    from this software without specific, prior written permission.
  21  *
  22  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  23  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  24  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
  25  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE
  26  * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
  27  * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
  28  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  29  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
  30  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
  31  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
  32  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  33  * SUCH DAMAGE.
  34  *
  35  * $DragonFly: src/libexec/dma/net.c,v 1.8 2008/09/16 17:57:23 matthias Exp $
  36  */
  37
  38 #include <sys/param.h>
  39 #include <sys/queue.h>
  40 #include <sys/stat.h>
  41 #include <sys/types.h>
  42 #include <sys/socket.h>
  43 #include <netinet/in.h>
  44 #include <arpa/inet.h>
  45
  46 #ifdef HAVE_CRYPTO
  47 #include <openssl/ssl.h>
  48 #endif /* HAVE_CRYPTO */
  49
  50 #include <netdb.h>
  51 #include <setjmp.h>
  52 #include <signal.h>
  53 #include <syslog.h>
  54 #include <unistd.h>
  55
  56 #include "dma.h"
  57
  58 extern struct config *config;
  59 extern struct authusers authusers;
  60 static jmp_buf timeout_alarm;
  61
  62 static void
  63 sig_alarm(int signo __unused)
  64 {
  65         longjmp(timeout_alarm, 1);
  66 }
  67
  68 ssize_t
  69 send_remote_command(int fd, const char* fmt, ...)
  70 {
  71         va_list va;
  72         char cmd[4096];
  73         ssize_t len = 0;
  74
  75         va_start(va, fmt);
  76         vsprintf(cmd, fmt, va);
  77
  78         if (((config->features & SECURETRANS) != 0) &&
  79             ((config->features & NOSSL) == 0)) {
  80                 len = SSL_write(config->ssl, (const char*)cmd, strlen(cmd));
  81                 SSL_write(config->ssl, "\r\n", 2);
  82         }
  83         else {
  84                 len = write(fd, cmd, strlen(cmd));
  85                 write(fd, "\r\n", 2);
  86         }
  87         va_end(va);
  88
  89         return (len+2);
  90 }
  91
  92 int
  93 read_remote(int fd, int extbufsize, char *extbuf)
  94 {
  95         ssize_t rlen = 0;
  96         size_t pos, len;
  97         char buff[BUF_SIZE];
  98         int done = 0, status = 0, extbufpos = 0;
  99
 100         if (signal(SIGALRM, sig_alarm) == SIG_ERR) {
 101                 syslog(LOG_ERR, "SIGALRM error: %m");
 102         }
 103         if (setjmp(timeout_alarm) != 0) {
 104                 syslog(LOG_ERR, "Timeout reached");
 105                 return (1);
 106         }
 107         alarm(CON_TIMEOUT);
 108
 109         /*
 110          * Remote reading code from femail.c written by Henning Brauer of
 111          * OpenBSD and released under a BSD style license.
 112          */
 113         for (len = pos = 0; !done; ) {
 114                 rlen = 0;
 115                 if (pos == 0 ||
 116                     (pos > 0 && memchr(buff + pos, '\n', len - pos) == NULL)) {
 117                         memmove(buff, buff + pos, len - pos);
 118                         len -= pos;
 119                         pos = 0;
 120                         if (((config->features & SECURETRANS) != 0) &&
 121                             (config->features & NOSSL) == 0) {
 122                                 if ((rlen = SSL_read(config->ssl, buff + len,
 123                                     sizeof(buff) - len)) == -1)
 124                                         err(1, "read");
 125                         } else {
 126                                 if ((rlen = read(fd, buff + len,
 127                                     sizeof(buff) - len)) == -1)
 128                                         err(1, "read");
 129                         }
 130                         len += rlen;
 131                 }
 132                 /*
 133                  * If there is an external buffer with a size bigger than zero
 134                  * and as long as there is space in the external buffer and
 135                  * there are new characters read from the mailserver
 136                  * copy them to the external buffer
 137                  */
 138                 if (extbufpos <= (extbufsize - 1) && rlen && extbufsize > 0
 139                     && extbuf != NULL) {
 140                         /* do not write over the bounds of the buffer */
 141                         if(extbufpos + rlen > (extbufsize - 1)) {
 142                                 rlen = extbufsize - extbufpos;
 143                         }
 144                         memcpy(extbuf + extbufpos, buff + len - rlen, rlen);
 145                         extbufpos += rlen;
 146                 }
 147                 for (; pos < len && buff[pos] >= '0' && buff[pos] <= '9'; pos++)
 148                         ; /* Do nothing */
 149
 150                 if (pos == len)
 151                         return (0);
 152
 153                 if (buff[pos] == ' ')
 154                         done = 1;
 155                 else if (buff[pos] != '-')
 156                         syslog(LOG_ERR, "invalid syntax in reply from server");
 157
 158                 /* skip up to \n */
 159                 for (; pos < len && buff[pos - 1] != '\n'; pos++)
 160                         ; /* Do nothing */
 161
 162         }
 163         alarm(0);
 164
 165         status = atoi(buff);
 166         return (status/100);
 167 }
 168
 169 /*
 170  * Handle SMTP authentication
 171  */
 172 static int
 173 smtp_login(struct qitem *it, int fd, char *login, char* password)
 174 {
 175         char *temp;
 176         int len, res = 0;
 177
 178 #ifdef HAVE_CRYPTO
 179         res = smtp_auth_md5(it, fd, login, password);
 180         if (res == 0) {
 181                 return (0);
 182         } else if (res == -2) {
 183         /*
 184          * If the return code is -2, then then the login attempt failed,
 185          * do not try other login mechanisms
 186          */
 187                 return (-1);
 188         }
 189 #endif /* HAVE_CRYPTO */
 190
 191         if ((config->features & INSECURE) != 0) {
 192                 /* Send AUTH command according to RFC 2554 */
 193                 send_remote_command(fd, "AUTH LOGIN");
 194                 if (read_remote(fd, 0, NULL) != 3) {
 195                         syslog(LOG_ERR, "%s: remote delivery deferred:"
 196                                         " AUTH login not available: %m", it->queueid);
 197                         return (1);
 198                 }
 199
 200                 len = base64_encode(login, strlen(login), &temp);
 201                 if (len <= 0)
 202                         return (-1);
 203
 204                 send_remote_command(fd, "%s", temp);
 205                 if (read_remote(fd, 0, NULL) != 3) {
 206                         syslog(LOG_ERR, "%s: remote delivery deferred:"
 207                                         " AUTH login failed: %m", it->queueid);
 208                         return (-1);
 209                 }
 210
 211                 len = base64_encode(password, strlen(password), &temp);
 212                 if (len <= 0)
 213                         return (-1);
 214
 215                 send_remote_command(fd, "%s", temp);
 216                 res = read_remote(fd, 0, NULL);
 217                 if (res == 5) {
 218                         syslog(LOG_ERR, "%s: remote delivery failed:"
 219                                         " Authentication failed: %m", it->queueid);
 220                         return (-1);
 221                 } else if (res != 2) {
 222                         syslog(LOG_ERR, "%s: remote delivery failed:"
 223                                         " AUTH password failed: %m", it->queueid);
 224                         return (-1);
 225                 }
 226         } else {
 227                 syslog(LOG_ERR, "%s: non-encrypted SMTP login is disabled in config, so skipping it. ",
 228                                 it->queueid);
 229                 return (1);
 230         }
 231
 232         return (0);
 233 }
 234
 235 static int
 236 open_connection(struct qitem *it, const char *host)
 237 {
 238         struct addrinfo hints, *res, *res0;
 239         char servname[128];
 240         const char *errmsg = NULL;
 241         int fd, error = 0, port;
 242
 243         if (config->port != 0)
 244                 port = config->port;
 245         else
 246                 port = SMTP_PORT;
 247
 248         /* FIXME get MX record of host */
 249         /* Shamelessly taken from getaddrinfo(3) */
 250         memset(&hints, 0, sizeof(hints));
 251         hints.ai_family = PF_UNSPEC;
 252         hints.ai_socktype = SOCK_STREAM;
 253         hints.ai_protocol = IPPROTO_TCP;
 254
 255         snprintf(servname, sizeof(servname), "%d", port);
 256         error = getaddrinfo(host, servname, &hints, &res0);
 257         if (error) {
 258                 syslog(LOG_ERR, "%s: remote delivery deferred: "
 259                        "%s: %m", it->queueid, gai_strerror(error));
 260                 return (-1);
 261         }
 262         fd = -1;
 263         for (res = res0; res; res = res->ai_next) {
 264                 fd=socket(res->ai_family, res->ai_socktype, res->ai_protocol);
 265                 if (fd < 0) {
 266                         errmsg = "socket failed";
 267                         continue;
 268                 }
 269                 if (connect(fd, res->ai_addr, res->ai_addrlen) < 0) {
 270                         errmsg = "connect failed";
 271                         close(fd);
 272                         fd = -1;
 273                         continue;
 274                 }
 275                 break;
 276         }
 277         if (fd < 0) {
 278                 syslog(LOG_ERR, "%s: remote delivery deferred: %s (%s:%s)",
 279                         it->queueid, errmsg, host, servname);
 280                 freeaddrinfo(res0);
 281                 return (-1);
 282         }
 283         freeaddrinfo(res0);
 284         return (fd);
 285 }
 286
 287 static void
 288 copy_qitem(struct qitem *target, struct qitem *it) {
 289         target->sender = it->sender;
 290         target->addr = it->addr;
 291         target->pipeuser = it->pipeuser;
 292         target->queuefn = it->queuefn;
 293         target->queueid = it->queueid;
 294         target->queuef = it->queuef;
 295         target->hdrlen = it->hdrlen;
 296         target->local = 0;
 297 }
 298
 299 int
 300 deliver_remote(struct qitem *it, const char **errmsg, struct queue **queue)
 301 {
 302         struct authuser *a;
 303         char *host, line[1000];
 304         int fd, error = 0, do_auth = 0, res = 0;
 305         size_t linelen;
 306
 307         host = strrchr(it->addr, '@');
 308         /* Should not happen */
 309         if (host == NULL)
 310                 return(-1);
 311         else
 312                 /* Step over the @ */
 313                 host++;
 314
 315         /* Smarthost support? */
 316         if (config->smarthost != NULL && strlen(config->smarthost) > 0) {
 317                 syslog(LOG_INFO, "%s: using smarthost (%s)",
 318                        it->queueid, config->smarthost);
 319                 host = config->smarthost;
 320         }
 321
 322         fd = open_connection(it, host);
 323         if (fd < 0)
 324                 return(1);
 325
 326         /* Check first reply from remote host */
 327         config->features |= NOSSL;
 328         res = read_remote(fd, 0, NULL);
 329         if (res != 2) {
 330                 syslog(LOG_INFO, "%s: Invalid initial response: %i",
 331                         it->queueid, res);
 332                 return(1);
 333         }
 334         config->features &= ~NOSSL;
 335
 336 #ifdef HAVE_CRYPTO
 337         if ((config->features & SECURETRANS) != 0) {
 338                 error = smtp_init_crypto(it, fd, config->features);
 339                 if (error >= 0)
 340                         syslog(LOG_INFO, "%s: SSL initialization successful",
 341                                 it->queueid);
 342                 else
 343                         goto out;
 344         }
 345
 346         /*
 347          * If the user doesn't want STARTTLS, but SSL encryption, we
 348          * have to enable SSL first, then send EHLO
 349          */
 350         if (((config->features & STARTTLS) == 0) &&
 351             ((config->features & SECURETRANS) != 0)) {
 352                 send_remote_command(fd, "EHLO %s", hostname());
 353                 if (read_remote(fd, 0, NULL) != 2) {
 354                         syslog(LOG_ERR, "%s: remote delivery deferred: "
 355                                " EHLO failed: %m", it->queueid);
 356                         return (-1);
 357                 }
 358         }
 359 #endif /* HAVE_CRYPTO */
 360         if (((config->features & SECURETRANS) == 0)) {
 361                 send_remote_command(fd, "EHLO %s", hostname());
 362                 if (read_remote(fd, 0, NULL) != 2) {
 363                         syslog(LOG_ERR, "%s: remote delivery deferred: "
 364                                " EHLO failed: %m", it->queueid);
 365                         return (-1);
 366                 }
 367         }
 368
 369         /*
 370          * Use SMTP authentication if the user defined an entry for the remote
 371          * or smarthost
 372          */
 373         SLIST_FOREACH(a, &authusers, next) {
 374                 if (strcmp(a->host, host) == 0) {
 375                         do_auth = 1;
 376                         break;
 377                 }
 378         }
 379
 380         if (do_auth == 1) {
 381                 /*
 382                  * Check if the user wants plain text login without using
 383                  * encryption.
 384                  */
 385                 syslog(LOG_INFO, "%s: Use SMTP authentication",
 386                                 it->queueid);
 387                 error = smtp_login(it, fd, a->login, a->password);
 388                 if (error < 0) {
 389                         syslog(LOG_ERR, "%s: remote delivery failed:"
 390                                         " SMTP login failed: %m", it->queueid);
 391                         return(-1);
 392                 }
 393                 /* SMTP login is not available, so try without */
 394                 else if (error > 0)
 395                         syslog(LOG_ERR, "%s: SMTP login not available."
 396                                         " Try without", it->queueid);
 397         }
 398
 399         send_remote_command(fd, "MAIL FROM:<%s>", it->sender);
 400         if (read_remote(fd, 0, NULL) != 2) {
 401                 syslog(LOG_ERR, "%s: remote delivery deferred:"
 402                        " MAIL FROM failed: %m", it->queueid);
 403                 return(1);
 404         }
 405
 406         if (queue == NULL) {
 407         /* without given queue send only to one receipient */
 408                 send_remote_command(fd, "RCPT TO:<%s>", it->addr);
 409                 if (read_remote(fd, 0, NULL) != 2) {
 410                         syslog(LOG_ERR, "%s: remote delivery deferred:"
 411                                         " RCPT TO failed: %m", it->queueid);
 412                         return(1);
 413                 }
 414         } else {
 415         /* Iterate over all recepients and open only one connection */
 416 /*
 417  * we need 3 queues:
 418  *      -delivered addresses
 419  *      -temporary errors
 420  *      -permanent errors
 421  * these 3 queues are given in **queues (+the first queue with all the qitems to send)
 422  *
 423  */
 424
 425                 struct qitem *tit;
 426                 int rcpt_success = 0;
 427                 struct stat st;
 428                 LIST_FOREACH(tit, &queue[0]->queue, next) {
 429                         struct qitem *qit;
 430                         qit = calloc(1, sizeof(struct qitem));
 431                         copy_qitem(qit, tit);
 432
 433                         if (stat(tit->queuefn, &st) != 0) {
 434                                 syslog(LOG_ERR, "%s: lost queue file `%s'",
 435                                                 tit->queueid, tit->queuefn);
 436                                 /* drop qitem and mark it as successfully sent */
 437                                 LIST_INSERT_HEAD(&queue[1]->queue, qit, next);
 438                                 continue;
 439                         }
 440
 441                         send_remote_command(fd, "RCPT TO:<%s>", tit->addr);
 442                         switch (read_remote(fd, 0, NULL)) {
 443                         case 2: /* everythings fine, receipient accepted */
 444                                 /* add item to temporary queue, these items will be deleted in deliver_smarthost */
 445                                 rcpt_success = 1;
 446                                 LIST_INSERT_HEAD(&queue[1]->queue, qit, next);
 447                                 syslog(LOG_INFO, "%s: mail from=<%s> to=<%s>",
 448                                                 tit->queueid, tit->sender, tit->addr);
 449                                 break;
 450                         case 4: /* temporary error, try again later */
 451                                 /* add item to a temporary queue, these items will be tried again */
 452                                 LIST_INSERT_HEAD(&queue[2]->queue, qit, next);
 453                                 syslog(LOG_INFO, "%s: mail from=<%s> to=<%s>",
 454                                                 tit->queueid, tit->sender, tit->addr);
 455                                 syslog(LOG_ERR, "%s: remote delivery deferred:"
 456                                                 " RCPT TO failed: %m", tit->queueid);
 457                                 break;
 458                         case 5: /* permanent error, bounce */
 459                                 /* add item to a queue, which will be returned to deliver_smarthost */
 460                                 LIST_INSERT_HEAD(&queue[3]->queue, qit, next);
 461                                 syslog(LOG_INFO, "%s: mail from=<%s> to=<%s>",
 462                                                 tit->queueid, tit->sender, tit->addr);
 463                                 syslog(LOG_ERR, "%s: remote delivery failed:"
 464                                                 " RCPT TO failed: %m", tit->queueid);
 465                                 break;
 466                         }
 467                 }
 468                 /* if there was no successful RCPT TO, return _WITHOUT_ error */
 469                 if (!rcpt_success)
 470                         goto out;
 471         }
 472
 473         send_remote_command(fd, "DATA");
 474         if (read_remote(fd, 0, NULL) != 3) {
 475                 syslog(LOG_ERR, "%s: remote delivery deferred:"
 476                        " DATA failed: %m", it->queueid);
 477                 return (1);
 478         }
 479
 480         if (fseek(it->queuef, it->hdrlen, SEEK_SET) != 0) {
 481                 syslog(LOG_ERR, "%s: remote delivery deferred: cannot seek: %m",
 482                        it->queueid);
 483                 return (1);
 484         }
 485
 486         while (!feof(it->queuef)) {
 487                 if (fgets(line, sizeof(line), it->queuef) == NULL)
 488                         break;
 489                 linelen = strlen(line);
 490                 if (linelen == 0 || line[linelen - 1] != '\n') {
 491                         syslog(LOG_CRIT, "%s: remote delivery failed:"
 492                                 "corrupted queue file", it->queueid);
 493                         *errmsg = "corrupted queue file";
 494                         error = -1;
 495                         goto out;
 496                 }
 497
 498                 /* Remove trailing \n's and escape leading dots */
 499                 trim_line(line);
 500
 501                 /*
 502                  * If the first character is a dot, we escape it so the line
 503                  * length increases
 504                 */
 505                 if (line[0] == '.')
 506                         linelen++;
 507
 508                 if (send_remote_command(fd, "%s", line) != (ssize_t)linelen+1) {
 509                         syslog(LOG_ERR, "%s: remote delivery deferred: "
 510                                 "write error", it->queueid);
 511                         error = 1;
 512                         goto out;
 513                 }
 514         }
 515
 516         send_remote_command(fd, ".");
 517         if (read_remote(fd, 0, NULL) != 2) {
 518                 syslog(LOG_ERR, "%s: remote delivery deferred: %m",
 519                        it->queueid);
 520                 return (1);
 521         }
 522
 523         send_remote_command(fd, "QUIT");
 524         if (read_remote(fd, 0, NULL) != 2) {
 525                 syslog(LOG_ERR, "%s: remote delivery deferred: "
 526                        "QUIT failed: %m", it->queueid);
 527                 return (1);
 528         }
 529 out:
 530
 531         close(fd);
 532         return (error);
 533 }
 534