mail.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 Simon 'corecode' Schubert <corecode@fs.ei.tum.de>.
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions
   9  * are met:
  10  *
  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
  15  *    the documentation and/or other materials provided with the
  16  *    distribution.
  17  * 3. Neither the name of The DragonFly Project nor the names of its
  18  *    contributors may be used to endorse or promote products derived
  19  *    from this software without specific, prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  22  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  23  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
  24  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE
  25  * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
  26  * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
  27  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  28  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
  29  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
  30  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
  31  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  32  * SUCH DAMAGE.
  33  */
  34
  35 #include <errno.h>
  36 #include <inttypes.h>
  37 #include <signal.h>
  38 #include <syslog.h>
  39 #include <unistd.h>
  40
  41 #include "dma.h"
  42
  43 void
  44 bounce(struct qitem *it, const char *reason)
  45 {
  46         struct queue bounceq;
  47         char line[1000];
  48         size_t pos;
  49         int error;
  50
  51         /* Don't bounce bounced mails */
  52         if (it->sender[0] == 0) {
  53                 syslog(LOG_INFO, "can not bounce a bounce message, discarding");
  54                 exit(1);
  55         }
  56
  57         bzero(&bounceq, sizeof(bounceq));
  58         LIST_INIT(&bounceq.queue);
  59         bounceq.sender = "";
  60         if (add_recp(&bounceq, it->sender, EXPAND_WILDCARD) != 0)
  61                 goto fail;
  62
  63         if (newspoolf(&bounceq) != 0)
  64                 goto fail;
  65
  66         syslog(LOG_ERR, "delivery failed, bouncing as %s", bounceq.id);
  67         setlogident("%s", bounceq.id);
  68
  69         error = fprintf(bounceq.mailf,
  70                 "Received: from MAILER-DAEMON\n"
  71                 "\tid %s\n"
  72                 "\tby %s (%s)\n"
  73                 "\t%s\n"
  74                 "X-Original-To: <%s>\n"
  75                 "From: MAILER-DAEMON <>\n"
  76                 "To: %s\n"
  77                 "Subject: Mail delivery failed\n"
  78                 "Message-Id: <%s@%s>\n"
  79                 "Date: %s\n"
  80                 "\n"
  81                 "This is the %s at %s.\n"
  82                 "\n"
  83                 "There was an error delivering your mail to <%s>.\n"
  84                 "\n"
  85                 "%s\n"
  86                 "\n"
  87                 "%s\n"
  88                 "\n",
  89                 bounceq.id,
  90                 hostname(), VERSION,
  91                 rfc822date(),
  92                 it->addr,
  93                 it->sender,
  94                 bounceq.id, hostname(),
  95                 rfc822date(),
  96                 VERSION, hostname(),
  97                 it->addr,
  98                 reason,
  99                 config.features & FULLBOUNCE ?
 100                     "Original message follows." :
 101                     "Message headers follow.");
 102         if (error < 0)
 103                 goto fail;
 104
 105         if (fseek(it->mailf, 0, SEEK_SET) != 0)
 106                 goto fail;
 107         if (config.features & FULLBOUNCE) {
 108                 while ((pos = fread(line, 1, sizeof(line), it->mailf)) > 0) {
 109                         if (fwrite(line, 1, pos, bounceq.mailf) != pos)
 110                                 goto fail;
 111                 }
 112         } else {
 113                 while (!feof(it->mailf)) {
 114                         if (fgets(line, sizeof(line), it->mailf) == NULL)
 115                                 break;
 116                         if (line[0] == '\n')
 117                                 break;
 118                         if (fwrite(line, strlen(line), 1, bounceq.mailf) != 1)
 119                                 goto fail;
 120                 }
 121         }
 122
 123         if (linkspool(&bounceq) != 0)
 124                 goto fail;
 125         /* bounce is safe */
 126
 127         delqueue(it);
 128
 129         run_queue(&bounceq);
 130         /* NOTREACHED */
 131
 132 fail:
 133         syslog(LOG_CRIT, "error creating bounce: %m");
 134         delqueue(it);
 135         exit(1);
 136 }
 137
 138 struct parse_state {
 139         char addr[1000];
 140         int pos;
 141
 142         enum {
 143                 NONE = 0,
 144                 START,
 145                 MAIN,
 146                 EOL,
 147                 QUIT
 148         } state;
 149         int comment;
 150         int quote;
 151         int brackets;
 152         int esc;
 153 };
 154
 155 /*
 156  * Simplified RFC2822 header/address parsing.
 157  * We copy escapes and quoted strings directly, since
 158  * we have to pass them like this to the mail server anyways.
 159  * XXX local addresses will need treatment
 160  */
 161 static int
 162 parse_addrs(struct parse_state *ps, char *s, struct queue *queue)
 163 {
 164         char *addr;
 165
 166 again:
 167         switch (ps->state) {
 168         case NONE:
 169                 return (-1);
 170
 171         case START:
 172                 /* init our data */
 173                 bzero(ps, sizeof(*ps));
 174
 175                 /* skip over header name */
 176                 while (*s != ':')
 177                         s++;
 178                 s++;
 179                 ps->state = MAIN;
 180                 break;
 181
 182         case MAIN:
 183                 /* all fine */
 184                 break;
 185
 186         case EOL:
 187                 switch (*s) {
 188                 case ' ':
 189                 case '\t':
 190                         s++;
 191                         /* continue */
 192                         break;
 193
 194                 default:
 195                         ps->state = QUIT;
 196                         if (ps->pos != 0)
 197                                 goto newaddr;
 198                         return (0);
 199                 }
 200
 201         case QUIT:
 202                 return (0);
 203         }
 204
 205         for (; *s != 0; s++) {
 206                 if (ps->esc) {
 207                         ps->esc = 0;
 208
 209                         switch (*s) {
 210                         case '\r':
 211                         case '\n':
 212                                 goto err;
 213
 214                         default:
 215                                 goto copy;
 216                         }
 217                 }
 218
 219                 if (ps->quote) {
 220                         switch (*s) {
 221                         case '"':
 222                                 ps->quote = 0;
 223                                 goto copy;
 224
 225                         case '\\':
 226                                 ps->esc = 1;
 227                                 goto copy;
 228
 229                         case '\r':
 230                         case '\n':
 231                                 goto eol;
 232
 233                         default:
 234                                 goto copy;
 235                         }
 236                 }
 237
 238                 switch (*s) {
 239                 case '(':
 240                         ps->comment++;
 241                         break;
 242
 243                 case ')':
 244                         if (ps->comment)
 245                                 ps->comment--;
 246                         else
 247                                 goto err;
 248                         goto skip;
 249
 250                 case '"':
 251                         ps->quote = 1;
 252                         goto copy;
 253
 254                 case '\\':
 255                         ps->esc = 1;
 256                         goto copy;
 257
 258                 case '\r':
 259                 case '\n':
 260                         goto eol;
 261                 }
 262
 263                 if (ps->comment)
 264                         goto skip;
 265
 266                 switch (*s) {
 267                 case ' ':
 268                 case '\t':
 269                         /* ignore whitespace */
 270                         goto skip;
 271
 272                 case '<':
 273                         /* this is the real address now */
 274                         ps->brackets = 1;
 275                         ps->pos = 0;
 276                         goto skip;
 277
 278                 case '>':
 279                         if (!ps->brackets)
 280                                 goto err;
 281                         ps->brackets = 0;
 282
 283                         s++;
 284                         goto newaddr;
 285
 286                 case ':':
 287                         /* group - ignore */
 288                         ps->pos = 0;
 289                         goto skip;
 290
 291                 case ',':
 292                 case ';':
 293                         /*
 294                          * Next address, copy previous one.
 295                          * However, we might be directly after
 296                          * a <address>, or have two consecutive
 297                          * commas.
 298                          * Skip the comma unless there is
 299                          * really something to copy.
 300                          */
 301                         if (ps->pos == 0)
 302                                 goto skip;
 303                         s++;
 304                         goto newaddr;
 305
 306                 default:
 307                         goto copy;
 308                 }
 309
 310 copy:
 311                 if (ps->comment)
 312                         goto skip;
 313
 314                 if (ps->pos + 1 == sizeof(ps->addr))
 315                         goto err;
 316                 ps->addr[ps->pos++] = *s;
 317
 318 skip:
 319                 ;
 320         }
 321
 322 eol:
 323         ps->state = EOL;
 324         return (0);
 325
 326 err:
 327         ps->state = QUIT;
 328         return (-1);
 329
 330 newaddr:
 331         ps->addr[ps->pos] = 0;
 332         ps->pos = 0;
 333         addr = strdup(ps->addr);
 334         if (addr == NULL)
 335                 errlog(1, NULL);
 336
 337         if (add_recp(queue, addr, EXPAND_WILDCARD) != 0)
 338                 errlogx(1, "invalid recipient `%s'", addr);
 339
 340         goto again;
 341 }
 342
 343 int
 344 readmail(struct queue *queue, int nodot, int recp_from_header)
 345 {
 346         struct parse_state parse_state;
 347         char line[1000];        /* by RFC2822 */
 348         size_t linelen;
 349         size_t error;
 350         int had_headers = 0;
 351         int had_from = 0;
 352         int had_messagid = 0;
 353         int had_date = 0;
 354         int had_last_line = 0;
 355         int nocopy = 0;
 356
 357         parse_state.state = NONE;
 358
 359         error = fprintf(queue->mailf,
 360                 "Received: from %s (uid %d)\n"
 361                 "\t(envelope-from %s)\n"
 362                 "\tid %s\n"
 363                 "\tby %s (%s)\n"
 364                 "\t%s\n",
 365                 username, useruid,
 366                 queue->sender,
 367                 queue->id,
 368                 hostname(), VERSION,
 369                 rfc822date());
 370         if ((ssize_t)error < 0)
 371                 return (-1);
 372
 373         while (!feof(stdin)) {
 374                 if (fgets(line, sizeof(line) - 1, stdin) == NULL)
 375                         break;
 376                 if (had_last_line)
 377                         errlogx(1, "bad mail input format");
 378                 linelen = strlen(line);
 379                 if (linelen == 0 || line[linelen - 1] != '\n') {
 380                         /*
 381                          * This line did not end with a newline character.
 382                          * If we fix it, it better be the last line of
 383                          * the file.
 384                          */
 385                         line[linelen] = '\n';
 386                         line[linelen + 1] = 0;
 387                         had_last_line = 1;
 388                 }
 389                 if (!had_headers) {
 390                         /*
 391                          * Unless this is a continuation, switch of
 392                          * the Bcc: nocopy flag.
 393                          */
 394                         if (!(line[0] == ' ' || line[0] == '\t'))
 395                                 nocopy = 0;
 396
 397                         if (strprefixcmp(line, "Date:") == 0)
 398                                 had_date = 1;
 399                         else if (strprefixcmp(line, "Message-Id:") == 0)
 400                                 had_messagid = 1;
 401                         else if (strprefixcmp(line, "From:") == 0)
 402                                 had_from = 1;
 403                         else if (strprefixcmp(line, "Bcc:") == 0)
 404                                 nocopy = 1;
 405
 406                         if (parse_state.state != NONE) {
 407                                 if (parse_addrs(&parse_state, line, queue) < 0) {
 408                                         errlogx(1, "invalid address in header\n");
 409                                         /* NOTREACHED */
 410                                 }
 411                         }
 412
 413                         if (recp_from_header && (
 414                                         strprefixcmp(line, "To:") == 0 ||
 415                                         strprefixcmp(line, "Cc:") == 0 ||
 416                                         strprefixcmp(line, "Bcc:") == 0)) {
 417                                 parse_state.state = START;
 418                                 if (parse_addrs(&parse_state, line, queue) < 0) {
 419                                         errlogx(1, "invalid address in header\n");
 420                                         /* NOTREACHED */
 421                                 }
 422                         }
 423                 }
 424
 425                 if (strcmp(line, "\n") == 0 && !had_headers) {
 426                         had_headers = 1;
 427                         while (!had_date || !had_messagid || !had_from) {
 428                                 if (!had_date) {
 429                                         had_date = 1;
 430                                         snprintf(line, sizeof(line), "Date: %s\n", rfc822date());
 431                                 } else if (!had_messagid) {
 432                                         /* XXX msgid, assign earlier and log? */
 433                                         had_messagid = 1;
 434                                         snprintf(line, sizeof(line), "Message-Id: <%"PRIxMAX".%s.%"PRIxMAX"@%s>\n",
 435                                                  (uintmax_t)time(NULL),
 436                                                  queue->id,
 437                                                  (uintmax_t)random(),
 438                                                  hostname());
 439                                 } else if (!had_from) {
 440                                         had_from = 1;
 441                                         snprintf(line, sizeof(line), "From: <%s>\n", queue->sender);
 442                                 }
 443                                 if (fwrite(line, strlen(line), 1, queue->mailf) != 1)
 444                                         return (-1);
 445                         }
 446                         strcpy(line, "\n");
 447                 }
 448                 if (!nodot && linelen == 2 && line[0] == '.')
 449                         break;
 450                 if (!nocopy) {
 451                         if (fwrite(line, strlen(line), 1, queue->mailf) != 1)
 452                                 return (-1);
 453                 }
 454         }
 455
 456         return (0);
 457 }