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 1.9 2008/09/30 17:47:21 swildner 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 <err.h>
  51 #include <netdb.h>
  52 #include <setjmp.h>
  53 #include <signal.h>
  54 #include <syslog.h>
  55 #include <unistd.h>
  56
  57 #include "dma.h"
  58
  59 extern struct config *config;
  60 extern struct authusers authusers;
  61 static jmp_buf timeout_alarm;
  62
  63 static void
  64 sig_alarm(int signo __unused)
  65 {
  66         longjmp(timeout_alarm, 1);
  67 }
  68
  69 ssize_t
  70 send_remote_command(int fd, const char* fmt, ...)
  71 {
  72         va_list va;
  73         char cmd[4096];
  74         ssize_t len = 0;
  75
  76         va_start(va, fmt);
  77         vsprintf(cmd, fmt, va);
  78
  79         if (((config->features & SECURETRANS) != 0) &&
  80             ((config->features & NOSSL) == 0)) {
  81                 len = SSL_write(config->ssl, (const char*)cmd, strlen(cmd));
  82                 SSL_write(config->ssl, "\r\n", 2);
  83         }
  84         else {
  85                 len = write(fd, cmd, strlen(cmd));
  86                 write(fd, "\r\n", 2);
  87         }
  88         va_end(va);
  89
  90         return (len+2);
  91 }
  92
  93 int
  94 read_remote(int fd, int extbufsize, char *extbuf)
  95 {
  96         ssize_t rlen = 0;
  97         size_t pos, len;
  98         char buff[BUF_SIZE];
  99         int done = 0, status = 0, extbufpos = 0;
 100
 101         if (signal(SIGALRM, sig_alarm) == SIG_ERR) {
 102                 syslog(LOG_ERR, "SIGALRM error: %m");
 103         }
 104         if (setjmp(timeout_alarm) != 0) {
 105                 syslog(LOG_ERR, "Timeout reached");
 106                 return (1);
 107         }
 108         alarm(CON_TIMEOUT);
 109
 110         /*
 111          * Remote reading code from femail.c written by Henning Brauer of
 112          * OpenBSD and released under a BSD style license.
 113          */
 114         for (len = pos = 0; !done; ) {
 115                 rlen = 0;
 116                 if (pos == 0 ||
 117                     (pos > 0 && memchr(buff + pos, '\n', len - pos) == NULL)) {
 118                         memmove(buff, buff + pos, len - pos);
 119                         len -= pos;
 120                         pos = 0;
 121                         if (((config->features & SECURETRANS) != 0) &&
 122                             (config->features & NOSSL) == 0) {
 123                                 if ((rlen = SSL_read(config->ssl, buff + len,
 124                                     sizeof(buff) - len)) == -1)
 125                                         err(1, "read");
 126                         } else {
 127                                 if ((rlen = read(fd, buff + len,
 128                                     sizeof(buff) - len)) == -1)
 129                                         err(1, "read");
 130                         }
 131                         len += rlen;
 132                 }
 133                 /*
 134                  * If there is an external buffer with a size bigger than zero
 135                  * and as long as there is space in the external buffer and
 136                  * there are new characters read from the mailserver
 137                  * copy them to the external buffer
 138                  */
 139                 if (extbufpos <= (extbufsize - 1) && rlen && extbufsize > 0
 140                     && extbuf != NULL) {
 141                         /* do not write over the bounds of the buffer */
 142                         if(extbufpos + rlen > (extbufsize - 1)) {
 143                                 rlen = extbufsize - extbufpos;
 144                         }
 145                         memcpy(extbuf + extbufpos, buff + len - rlen, rlen);
 146                         extbufpos += rlen;
 147                 }
 148                 for (; pos < len && buff[pos] >= '0' && buff[pos] <= '9'; pos++)
 149                         ; /* Do nothing */
 150
 151                 if (pos == len)
 152                         return (0);
 153
 154                 if (buff[pos] == ' ')
 155                         done = 1;
 156                 else if (buff[pos] != '-')
 157                         syslog(LOG_ERR, "invalid syntax in reply from server");
 158
 159                 /* skip up to \n */
 160                 for (; pos < len && buff[pos - 1] != '\n'; pos++)
 161                         ; /* Do nothing */
 162
 163         }
 164         alarm(0);
 165
 166         status = atoi(buff);
 167         return (status/100);
 168 }
 169
 170 /*
 171  * Handle SMTP authentication
 172  */
 173 static int
 174 smtp_login(struct qitem *it, int fd, char *login, char* password)
 175 {
 176         char *temp;
 177         int len, res = 0;
 178
 179 #ifdef HAVE_CRYPTO
 180         res = smtp_auth_md5(it, fd, login, password);
 181         if (res == 0) {
 182                 return (0);
 183         } else if (res == -2) {
 184         /*
 185          * If the return code is -2, then then the login attempt failed,
 186          * do not try other login mechanisms
 187          */
 188                 return (-1);
 189         }
 190 #endif /* HAVE_CRYPTO */
 191
 192         if ((config->features & INSECURE) != 0) {
 193                 /* Send AUTH command according to RFC 2554 */
 194                 send_remote_command(fd, "AUTH LOGIN");
 195                 if (read_remote(fd, 0, NULL) != 3) {
 196                         syslog(LOG_ERR, "%s: remote delivery deferred:"
 197                                         " AUTH login not available: %m", it->queueid);
 198                         return (1);
 199                 }
 200
 201                 len = base64_encode(login, strlen(login), &temp);
 202                 if (len <= 0)
 203                         return (-1);
 204
 205                 send_remote_command(fd, "%s", temp);
 206                 if (read_remote(fd, 0, NULL) != 3) {
 207                         syslog(LOG_ERR, "%s: remote delivery deferred:"
 208                                         " AUTH login failed: %m", it->queueid);
 209                         return (-1);
 210                 }
 211
 212                 len = base64_encode(password, strlen(password), &temp);
 213                 if (len <= 0)
 214                         return (-1);
 215
 216                 send_remote_command(fd, "%s", temp);
 217                 res = read_remote(fd, 0, NULL);
 218                 if (res == 5) {
 219                         syslog(LOG_ERR, "%s: remote delivery failed:"
 220                                         " Authentication failed: %m", it->queueid);
 221                         return (-1);
 222                 } else if (res != 2) {
 223                         syslog(LOG_ERR, "%s: remote delivery failed:"
 224                                         " AUTH password failed: %m", it->queueid);
 225                         return (-1);
 226                 }
 227         } else {
 228                 syslog(LOG_ERR, "%s: non-encrypted SMTP login is disabled in config, so skipping it. ",
 229                                 it->queueid);
 230                 return (1);
 231         }
 232
 233         return (0);
 234 }
 235
 236 static int
 237 open_connection(struct qitem *it, const char *host)
 238 {
 239         struct addrinfo hints, *res, *res0;
 240         char servname[128];
 241         const char *errmsg = NULL;
 242         int fd, error = 0, port;
 243
 244         if (config->port != 0)
 245                 port = config->port;
 246         else
 247                 port = SMTP_PORT;
 248
 249         /* FIXME get MX record of host */
 250         /* Shamelessly taken from getaddrinfo(3) */
 251         memset(&hints, 0, sizeof(hints));
 252         hints.ai_family = PF_UNSPEC;
 253         hints.ai_socktype = SOCK_STREAM;
 254         hints.ai_protocol = IPPROTO_TCP;
 255
 256         snprintf(servname, sizeof(servname), "%d", port);
 257         error = getaddrinfo(host, servname, &hints, &res0);
 258         if (error) {
 259                 syslog(LOG_ERR, "%s: remote delivery deferred: "
 260                        "%s: %m", it->queueid, gai_strerror(error));
 261                 return (-1);
 262         }
 263         fd = -1;
 264         for (res = res0; res; res = res->ai_next) {
 265                 fd=socket(res->ai_family, res->ai_socktype, res->ai_protocol);
 266                 if (fd < 0) {
 267                         errmsg = "socket failed";
 268                         continue;
 269                 }
 270                 if (connect(fd, res->ai_addr, res->ai_addrlen) < 0) {
 271                         errmsg = "connect failed";
 272                         close(fd);
 273                         fd = -1;
 274                         continue;
 275                 }
 276                 break;
 277         }
 278         if (fd < 0) {
 279                 syslog(LOG_ERR, "%s: remote delivery deferred: %s (%s:%s)",
 280                         it->queueid, errmsg, host, servname);
 281                 freeaddrinfo(res0);
 282                 return (-1);
 283         }
 284         freeaddrinfo(res0);
 285         return (fd);
 286 }
 287
 288 int
 289 deliver_remote(struct qitem *it, const char **errmsg)
 290 {
 291         struct authuser *a;
 292         char *host, line[1000];
 293         int fd, error = 0, do_auth = 0, res = 0;
 294         size_t linelen;
 295
 296         host = strrchr(it->addr, '@');
 297         /* Should not happen */
 298         if (host == NULL)
 299                 return(-1);
 300         else
 301                 /* Step over the @ */
 302                 host++;
 303
 304         /* Smarthost support? */
 305         if (config->smarthost != NULL && strlen(config->smarthost) > 0) {
 306                 syslog(LOG_INFO, "%s: using smarthost (%s:%i)",
 307                        it->queueid, config->smarthost, config->port);
 308                 host = config->smarthost;
 309         }
 310
 311         fd = open_connection(it, host);
 312         if (fd < 0)
 313                 return (1);
 314
 315         /* Check first reply from remote host */
 316         config->features |= NOSSL;
 317         res = read_remote(fd, 0, NULL);
 318         if (res != 2) {
 319                 syslog(LOG_INFO, "%s: Invalid initial response: %i",
 320                         it->queueid, res);
 321                 return(1);
 322         }
 323         config->features &= ~NOSSL;
 324
 325 #ifdef HAVE_CRYPTO
 326         if ((config->features & SECURETRANS) != 0) {
 327                 error = smtp_init_crypto(it, fd, config->features);
 328                 if (error >= 0)
 329                         syslog(LOG_INFO, "%s: SSL initialization successful",
 330                                 it->queueid);
 331                 else
 332                         goto out;
 333         }
 334
 335         /*
 336          * If the user doesn't want STARTTLS, but SSL encryption, we
 337          * have to enable SSL first, then send EHLO
 338          */
 339         if (((config->features & STARTTLS) == 0) &&
 340             ((config->features & SECURETRANS) != 0)) {
 341                 send_remote_command(fd, "EHLO %s", hostname());
 342                 if (read_remote(fd, 0, NULL) != 2) {
 343                         syslog(LOG_ERR, "%s: remote delivery deferred: "
 344                                " EHLO failed: %m", it->queueid);
 345                         return (-1);
 346                 }
 347         }
 348 #endif /* HAVE_CRYPTO */
 349         if (((config->features & SECURETRANS) == 0)) {
 350                 send_remote_command(fd, "EHLO %s", hostname());
 351                 if (read_remote(fd, 0, NULL) != 2) {
 352                         syslog(LOG_ERR, "%s: remote delivery deferred: "
 353                                " EHLO failed: %m", it->queueid);
 354                         return (-1);
 355                 }
 356         }
 357
 358         /*
 359          * Use SMTP authentication if the user defined an entry for the remote
 360          * or smarthost
 361          */
 362         SLIST_FOREACH(a, &authusers, next) {
 363                 if (strcmp(a->host, host) == 0) {
 364                         do_auth = 1;
 365                         break;
 366                 }
 367         }
 368
 369         if (do_auth == 1) {
 370                 /*
 371                  * Check if the user wants plain text login without using
 372                  * encryption.
 373                  */
 374                 syslog(LOG_INFO, "%s: Use SMTP authentication",
 375                                 it->queueid);
 376                 error = smtp_login(it, fd, a->login, a->password);
 377                 if (error < 0) {
 378                         syslog(LOG_ERR, "%s: remote delivery failed:"
 379                                         " SMTP login failed: %m", it->queueid);
 380                         return (-1);
 381                 }
 382                 /* SMTP login is not available, so try without */
 383                 else if (error > 0)
 384                         syslog(LOG_ERR, "%s: SMTP login not available."
 385                                         " Try without", it->queueid);
 386         }
 387
 388         send_remote_command(fd, "MAIL FROM:<%s>", it->sender);
 389         if (read_remote(fd, 0, NULL) != 2) {
 390                 syslog(LOG_ERR, "%s: remote delivery deferred:"
 391                        " MAIL FROM failed: %m", it->queueid);
 392                 return (1);
 393         }
 394
 395         send_remote_command(fd, "RCPT TO:<%s>", it->addr);
 396         if (read_remote(fd, 0, NULL) != 2) {
 397                 syslog(LOG_ERR, "%s: remote delivery deferred:"
 398                                 " RCPT TO failed: %m", it->queueid);
 399                 return (1);
 400         }
 401
 402         send_remote_command(fd, "DATA");
 403         if (read_remote(fd, 0, NULL) != 3) {
 404                 syslog(LOG_ERR, "%s: remote delivery deferred:"
 405                        " DATA failed: %m", it->queueid);
 406                 return (1);
 407         }
 408
 409         if (fseek(it->queuef, it->hdrlen, SEEK_SET) != 0) {
 410                 syslog(LOG_ERR, "%s: remote delivery deferred: cannot seek: %m",
 411                        it->queueid);
 412                 return (1);
 413         }
 414
 415         while (!feof(it->queuef)) {
 416                 if (fgets(line, sizeof(line), it->queuef) == NULL)
 417                         break;
 418                 linelen = strlen(line);
 419                 if (linelen == 0 || line[linelen - 1] != '\n') {
 420                         syslog(LOG_CRIT, "%s: remote delivery failed:"
 421                                 "corrupted queue file", it->queueid);
 422                         *errmsg = "corrupted queue file";
 423                         error = -1;
 424                         goto out;
 425                 }
 426
 427                 /* Remove trailing \n's and escape leading dots */
 428                 trim_line(line);
 429
 430                 /*
 431                  * If the first character is a dot, we escape it so the line
 432                  * length increases
 433                 */
 434                 if (line[0] == '.')
 435                         linelen++;
 436
 437                 if (send_remote_command(fd, "%s", line) != (ssize_t)linelen+1) {
 438                         syslog(LOG_ERR, "%s: remote delivery deferred: "
 439                                 "write error", it->queueid);
 440                         error = 1;
 441                         goto out;
 442                 }
 443         }
 444
 445         send_remote_command(fd, ".");
 446         if (read_remote(fd, 0, NULL) != 2) {
 447                 syslog(LOG_ERR, "%s: remote delivery deferred: %m",
 448                        it->queueid);
 449                 return (1);
 450         }
 451
 452         send_remote_command(fd, "QUIT");
 453         if (read_remote(fd, 0, NULL) != 2) {
 454                 syslog(LOG_ERR, "%s: remote delivery deferred: "
 455                        "QUIT failed: %m", it->queueid);
 456                 return (1);
 457         }
 458 out:
 459
 460         close(fd);
 461         return (error);
 462 }
 463