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 <errno.h>
  52 #include <netdb.h>
  53 #include <setjmp.h>
  54 #include <signal.h>
  55 #include <syslog.h>
  56 #include <unistd.h>
  57
  58 #include "dma.h"
  59
  60 extern struct config *config;
  61 extern struct authusers authusers;
  62 static jmp_buf timeout_alarm;
  63 char neterr[BUF_SIZE];
  64
  65 static void
  66 sig_alarm(int signo __unused)
  67 {
  68         longjmp(timeout_alarm, 1);
  69 }
  70
  71 ssize_t
  72 send_remote_command(int fd, const char* fmt, ...)
  73 {
  74         va_list va;
  75         char cmd[4096];
  76         ssize_t len = 0;
  77
  78         va_start(va, fmt);
  79         vsprintf(cmd, fmt, va);
  80
  81         if (((config->features & SECURETRANS) != 0) &&
  82             ((config->features & NOSSL) == 0)) {
  83                 len = SSL_write(config->ssl, (const char*)cmd, strlen(cmd));
  84                 SSL_write(config->ssl, "\r\n", 2);
  85         }
  86         else {
  87                 len = write(fd, cmd, strlen(cmd));
  88                 write(fd, "\r\n", 2);
  89         }
  90         va_end(va);
  91
  92         return (len+2);
  93 }
  94
  95 int
  96 read_remote(int fd, int extbufsize, char *extbuf)
  97 {
  98         ssize_t rlen = 0;
  99         size_t pos, len;
 100         char buff[BUF_SIZE];
 101         int done = 0, status = 0, extbufpos = 0;
 102
 103         if (signal(SIGALRM, sig_alarm) == SIG_ERR) {
 104                 snprintf(neterr, sizeof(neterr), "SIGALRM error: %s",
 105                     strerror(errno));
 106                 return (1);
 107         }
 108         if (setjmp(timeout_alarm) != 0) {
 109                 snprintf(neterr, sizeof(neterr), "Timeout reached");
 110                 return (1);
 111         }
 112         alarm(CON_TIMEOUT);
 113
 114         /*
 115          * Remote reading code from femail.c written by Henning Brauer of
 116          * OpenBSD and released under a BSD style license.
 117          */
 118         for (len = pos = 0; !done; ) {
 119                 rlen = 0;
 120                 if (pos == 0 ||
 121                     (pos > 0 && memchr(buff + pos, '\n', len - pos) == NULL)) {
 122                         memmove(buff, buff + pos, len - pos);
 123                         len -= pos;
 124                         pos = 0;
 125                         if (((config->features & SECURETRANS) != 0) &&
 126                             (config->features & NOSSL) == 0) {
 127                                 if ((rlen = SSL_read(config->ssl, buff + len,
 128                                     sizeof(buff) - len)) == -1)
 129                                         err(1, "read");
 130                         } else {
 131                                 if ((rlen = read(fd, buff + len,
 132                                     sizeof(buff) - len)) == -1)
 133                                         err(1, "read");
 134                         }
 135                         len += rlen;
 136                 }
 137                 /*
 138                  * If there is an external buffer with a size bigger than zero
 139                  * and as long as there is space in the external buffer and
 140                  * there are new characters read from the mailserver
 141                  * copy them to the external buffer
 142                  */
 143                 if (extbufpos <= (extbufsize - 1) && rlen && extbufsize > 0
 144                     && extbuf != NULL) {
 145                         /* do not write over the bounds of the buffer */
 146                         if(extbufpos + rlen > (extbufsize - 1)) {
 147                                 rlen = extbufsize - extbufpos;
 148                         }
 149                         memcpy(extbuf + extbufpos, buff + len - rlen, rlen);
 150                         extbufpos += rlen;
 151                 }
 152                 for (; pos < len && buff[pos] >= '0' && buff[pos] <= '9'; pos++)
 153                         ; /* Do nothing */
 154
 155                 if (pos == len)
 156                         return (0);
 157
 158                 if (buff[pos] == ' ')
 159                         done = 1;
 160                 else if (buff[pos] != '-')
 161                         syslog(LOG_ERR, "invalid syntax in reply from server");
 162
 163                 /* skip up to \n */
 164                 for (; pos < len && buff[pos - 1] != '\n'; pos++)
 165                         ; /* Do nothing */
 166
 167         }
 168         alarm(0);
 169
 170         buff[len] = '\0';
 171         while (len > 0 && (buff[len - 1] == '\r' || buff[len - 1] == '\n'))
 172                 buff[--len] = '\0';
 173         snprintf(neterr, sizeof(neterr), "%s", buff);
 174         status = atoi(buff);
 175         return (status/100);
 176 }
 177
 178 /*
 179  * Handle SMTP authentication
 180  */
 181 static int
 182 smtp_login(struct qitem *it, int fd, char *login, char* password)
 183 {
 184         char *temp;
 185         int len, res = 0;
 186
 187 #ifdef HAVE_CRYPTO
 188         res = smtp_auth_md5(it, fd, login, password);
 189         if (res == 0) {
 190                 return (0);
 191         } else if (res == -2) {
 192         /*
 193          * If the return code is -2, then then the login attempt failed,
 194          * do not try other login mechanisms
 195          */
 196                 return (-1);
 197         }
 198 #endif /* HAVE_CRYPTO */
 199
 200         if ((config->features & INSECURE) != 0) {
 201                 /* Send AUTH command according to RFC 2554 */
 202                 send_remote_command(fd, "AUTH LOGIN");
 203                 if (read_remote(fd, 0, NULL) != 3) {
 204                         syslog(LOG_ERR, "%s: remote delivery deferred:"
 205                                         " AUTH login not available: %s",
 206                                         it->queueid, neterr);
 207                         return (1);
 208                 }
 209
 210                 len = base64_encode(login, strlen(login), &temp);
 211                 if (len <= 0)
 212                         return (-1);
 213
 214                 send_remote_command(fd, "%s", temp);
 215                 if (read_remote(fd, 0, NULL) != 3) {
 216                         syslog(LOG_ERR, "%s: remote delivery deferred:"
 217                                         " AUTH login failed: %s", it->queueid,
 218                                         neterr);
 219                         return (-1);
 220                 }
 221
 222                 len = base64_encode(password, strlen(password), &temp);
 223                 if (len <= 0)
 224                         return (-1);
 225
 226                 send_remote_command(fd, "%s", temp);
 227                 res = read_remote(fd, 0, NULL);
 228                 if (res == 5) {
 229                         syslog(LOG_ERR, "%s: remote delivery failed:"
 230                                         " Authentication failed: %s",
 231                                         it->queueid, neterr);
 232                         return (-1);
 233                 } else if (res != 2) {
 234                         syslog(LOG_ERR, "%s: remote delivery failed:"
 235                                         " AUTH password failed: %s",
 236                                         it->queueid, neterr);
 237                         return (-1);
 238                 }
 239         } else {
 240                 syslog(LOG_ERR, "%s: non-encrypted SMTP login is disabled in config, so skipping it. ",
 241                                 it->queueid);
 242                 return (1);
 243         }
 244
 245         return (0);
 246 }
 247
 248 static int
 249 open_connection(struct qitem *it, const char *host)
 250 {
 251         struct addrinfo hints, *res, *res0;
 252         char servname[128];
 253         const char *errmsg = NULL;
 254         int fd, error = 0, port;
 255
 256         if (config->port != 0)
 257                 port = config->port;
 258         else
 259                 port = SMTP_PORT;
 260
 261         /* FIXME get MX record of host */
 262         /* Shamelessly taken from getaddrinfo(3) */
 263         memset(&hints, 0, sizeof(hints));
 264         hints.ai_family = PF_UNSPEC;
 265         hints.ai_socktype = SOCK_STREAM;
 266         hints.ai_protocol = IPPROTO_TCP;
 267
 268         snprintf(servname, sizeof(servname), "%d", port);
 269         error = getaddrinfo(host, servname, &hints, &res0);
 270         if (error) {
 271                 syslog(LOG_ERR, "%s: remote delivery deferred: "
 272                        "%s: %m", it->queueid, gai_strerror(error));
 273                 return (-1);
 274         }
 275         fd = -1;
 276         for (res = res0; res; res = res->ai_next) {
 277                 fd=socket(res->ai_family, res->ai_socktype, res->ai_protocol);
 278                 if (fd < 0) {
 279                         errmsg = "socket failed";
 280                         continue;
 281                 }
 282                 if (connect(fd, res->ai_addr, res->ai_addrlen) < 0) {
 283                         errmsg = "connect failed";
 284                         close(fd);
 285                         fd = -1;
 286                         continue;
 287                 }
 288                 break;
 289         }
 290         if (fd < 0) {
 291                 syslog(LOG_ERR, "%s: remote delivery deferred: %s (%s:%s)",
 292                         it->queueid, errmsg, host, servname);
 293                 freeaddrinfo(res0);
 294                 return (-1);
 295         }
 296         freeaddrinfo(res0);
 297         return (fd);
 298 }
 299
 300 int
 301 deliver_remote(struct qitem *it, const char **errmsg)
 302 {
 303         struct authuser *a;
 304         char *host, line[1000];
 305         int fd, error = 0, do_auth = 0, res = 0;
 306         size_t linelen;
 307
 308         host = strrchr(it->addr, '@');
 309         /* Should not happen */
 310         if (host == NULL)
 311                 return(-1);
 312         else
 313                 /* Step over the @ */
 314                 host++;
 315
 316         /* Smarthost support? */
 317         if (config->smarthost != NULL && strlen(config->smarthost) > 0) {
 318                 syslog(LOG_INFO, "%s: using smarthost (%s:%i)",
 319                        it->queueid, config->smarthost, config->port);
 320                 host = config->smarthost;
 321         }
 322
 323         fd = open_connection(it, host);
 324         if (fd < 0)
 325                 return (1);
 326
 327         /* Check first reply from remote host */
 328         config->features |= NOSSL;
 329         res = read_remote(fd, 0, NULL);
 330         if (res != 2) {
 331                 syslog(LOG_INFO, "%s: Invalid initial response: %i",
 332                         it->queueid, res);
 333                 return(1);
 334         }
 335         config->features &= ~NOSSL;
 336
 337 #ifdef HAVE_CRYPTO
 338         if ((config->features & SECURETRANS) != 0) {
 339                 error = smtp_init_crypto(it, fd, config->features);
 340                 if (error >= 0)
 341                         syslog(LOG_INFO, "%s: SSL initialization successful",
 342                                 it->queueid);
 343                 else
 344                         goto out;
 345         }
 346
 347         /*
 348          * If the user doesn't want STARTTLS, but SSL encryption, we
 349          * have to enable SSL first, then send EHLO
 350          */
 351         if (((config->features & STARTTLS) == 0) &&
 352             ((config->features & SECURETRANS) != 0)) {
 353                 send_remote_command(fd, "EHLO %s", hostname());
 354                 if (read_remote(fd, 0, NULL) != 2) {
 355                         syslog(LOG_ERR, "%s: remote delivery deferred: "
 356                                " EHLO failed: %s", it->queueid, neterr);
 357                         return (-1);
 358                 }
 359         }
 360 #endif /* HAVE_CRYPTO */
 361         if (((config->features & SECURETRANS) == 0)) {
 362                 send_remote_command(fd, "EHLO %s", hostname());
 363                 if (read_remote(fd, 0, NULL) != 2) {
 364                         syslog(LOG_ERR, "%s: remote delivery deferred: "
 365                                " EHLO failed: %s", it->queueid, neterr);
 366                         return (-1);
 367                 }
 368         }
 369
 370         /*
 371          * Use SMTP authentication if the user defined an entry for the remote
 372          * or smarthost
 373          */
 374         SLIST_FOREACH(a, &authusers, next) {
 375                 if (strcmp(a->host, host) == 0) {
 376                         do_auth = 1;
 377                         break;
 378                 }
 379         }
 380
 381         if (do_auth == 1) {
 382                 /*
 383                  * Check if the user wants plain text login without using
 384                  * encryption.
 385                  */
 386                 syslog(LOG_INFO, "%s: Use SMTP authentication",
 387                                 it->queueid);
 388                 error = smtp_login(it, fd, a->login, a->password);
 389                 if (error < 0) {
 390                         syslog(LOG_ERR, "%s: remote delivery failed:"
 391                                         " SMTP login failed: %m", it->queueid);
 392                         return (-1);
 393                 }
 394                 /* SMTP login is not available, so try without */
 395                 else if (error > 0)
 396                         syslog(LOG_ERR, "%s: SMTP login not available."
 397                                         " Try without", it->queueid);
 398         }
 399
 400         send_remote_command(fd, "MAIL FROM:<%s>", it->sender);
 401         if (read_remote(fd, 0, NULL) != 2) {
 402                 syslog(LOG_ERR, "%s: remote delivery deferred:"
 403                        " MAIL FROM failed: %s", it->queueid, neterr);
 404                 return (1);
 405         }
 406
 407         send_remote_command(fd, "RCPT TO:<%s>", it->addr);
 408         if (read_remote(fd, 0, NULL) != 2) {
 409                 syslog(LOG_ERR, "%s: remote delivery deferred:"
 410                                 " RCPT TO failed: %s", it->queueid, neterr);
 411                 return (1);
 412         }
 413
 414         send_remote_command(fd, "DATA");
 415         if (read_remote(fd, 0, NULL) != 3) {
 416                 syslog(LOG_ERR, "%s: remote delivery deferred:"
 417                        " DATA failed: %s", it->queueid, neterr);
 418                 return (1);
 419         }
 420
 421         if (fseek(it->queuef, it->hdrlen, SEEK_SET) != 0) {
 422                 syslog(LOG_ERR, "%s: remote delivery deferred: cannot seek: %s",
 423                        it->queueid, neterr);
 424                 return (1);
 425         }
 426
 427         while (!feof(it->queuef)) {
 428                 if (fgets(line, sizeof(line), it->queuef) == NULL)
 429                         break;
 430                 linelen = strlen(line);
 431                 if (linelen == 0 || line[linelen - 1] != '\n') {
 432                         syslog(LOG_CRIT, "%s: remote delivery failed:"
 433                                 "corrupted queue file", it->queueid);
 434                         *errmsg = "corrupted queue file";
 435                         error = -1;
 436                         goto out;
 437                 }
 438
 439                 /* Remove trailing \n's and escape leading dots */
 440                 trim_line(line);
 441
 442                 /*
 443                  * If the first character is a dot, we escape it so the line
 444                  * length increases
 445                 */
 446                 if (line[0] == '.')
 447                         linelen++;
 448
 449                 if (send_remote_command(fd, "%s", line) != (ssize_t)linelen+1) {
 450                         syslog(LOG_ERR, "%s: remote delivery deferred: "
 451                                 "write error", it->queueid);
 452                         error = 1;
 453                         goto out;
 454                 }
 455         }
 456
 457         send_remote_command(fd, ".");
 458         if (read_remote(fd, 0, NULL) != 2) {
 459                 syslog(LOG_ERR, "%s: remote delivery deferred: %s",
 460                        it->queueid, neterr);
 461                 return (1);
 462         }
 463
 464         send_remote_command(fd, "QUIT");
 465         if (read_remote(fd, 0, NULL) != 2)
 466                 syslog(LOG_WARNING, "%s: remote delivery succeeded but "
 467                        "QUIT failed: %s", it->queueid, neterr);
 468 out:
 469
 470         close(fd);
 471         return (error);
 472 }
 473