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 <syslog.h>
  37 #include <unistd.h>
  38
  39 #include "dma.h"
  40
  41 void
  42 bounce(struct qitem *it, const char *reason)
  43 {
  44         struct queue bounceq;
  45         char line[1000];
  46         size_t pos;
  47         int error;
  48
  49         /* Don't bounce bounced mails */
  50         if (it->sender[0] == 0) {
  51                 syslog(LOG_INFO, "can not bounce a bounce message, discarding");
  52                 exit(1);
  53         }
  54
  55         bzero(&bounceq, sizeof(bounceq));
  56         LIST_INIT(&bounceq.queue);
  57         bounceq.sender = "";
  58         if (add_recp(&bounceq, it->sender, 1) != 0)
  59                 goto fail;
  60
  61         if (newspoolf(&bounceq) != 0)
  62                 goto fail;
  63
  64         syslog(LOG_ERR, "delivery failed, bouncing as %s", bounceq.id);
  65         setlogident("%s", bounceq.id);
  66
  67         error = fprintf(bounceq.mailf,
  68                 "Received: from MAILER-DAEMON\n"
  69                 "\tid %s\n"
  70                 "\tby %s (%s)\n"
  71                 "\t%s\n"
  72                 "X-Original-To: <%s>\n"
  73                 "From: MAILER-DAEMON <>\n"
  74                 "To: %s\n"
  75                 "Subject: Mail delivery failed\n"
  76                 "Message-Id: <%s@%s>\n"
  77                 "Date: %s\n"
  78                 "\n"
  79                 "This is the %s at %s.\n"
  80                 "\n"
  81                 "There was an error delivering your mail to <%s>.\n"
  82                 "\n"
  83                 "%s\n"
  84                 "\n"
  85                 "%s\n"
  86                 "\n",
  87                 bounceq.id,
  88                 hostname(), VERSION,
  89                 rfc822date(),
  90                 it->addr,
  91                 it->sender,
  92                 bounceq.id, hostname(),
  93                 rfc822date(),
  94                 VERSION, hostname(),
  95                 it->addr,
  96                 reason,
  97                 config.features & FULLBOUNCE ?
  98                     "Original message follows." :
  99                     "Message headers follow.");
 100         if (error < 0)
 101                 goto fail;
 102
 103         if (fseek(it->mailf, 0, SEEK_SET) != 0)
 104                 goto fail;
 105         if (config.features & FULLBOUNCE) {
 106                 while ((pos = fread(line, 1, sizeof(line), it->mailf)) > 0) {
 107                         if (fwrite(line, 1, pos, bounceq.mailf) != pos)
 108                                 goto fail;
 109                 }
 110         } else {
 111                 while (!feof(it->mailf)) {
 112                         if (fgets(line, sizeof(line), it->mailf) == NULL)
 113                                 break;
 114                         if (line[0] == '\n')
 115                                 break;
 116                         if (fwrite(line, strlen(line), 1, bounceq.mailf) != 1)
 117                                 goto fail;
 118                 }
 119         }
 120
 121         if (linkspool(&bounceq) != 0)
 122                 goto fail;
 123         /* bounce is safe */
 124
 125         delqueue(it);
 126
 127         run_queue(&bounceq);
 128         /* NOTREACHED */
 129
 130 fail:
 131         syslog(LOG_CRIT, "error creating bounce: %m");
 132         delqueue(it);
 133         exit(1);
 134 }
 135
 136 struct parse_state {
 137         char addr[1000];
 138         int pos;
 139
 140         enum {
 141                 NONE = 0,
 142                 START,
 143                 MAIN,
 144                 EOL,
 145                 QUIT
 146         } state;
 147         int comment;
 148         int quote;
 149         int brackets;
 150         int esc;
 151 };
 152
 153 /*
 154  * Simplified RFC2822 header/address parsing.
 155  * We copy escapes and quoted strings directly, since
 156  * we have to pass them like this to the mail server anyways.
 157  * XXX local addresses will need treatment
 158  */
 159 static int
 160 parse_addrs(struct parse_state *ps, char *s, struct queue *queue)
 161 {
 162         char *addr;
 163
 164 again:
 165         switch (ps->state) {
 166         case NONE:
 167                 return (-1);
 168
 169         case START:
 170                 /* init our data */
 171                 bzero(ps, sizeof(*ps));
 172
 173                 /* skip over header name */
 174                 while (*s != ':')
 175                         s++;
 176                 s++;
 177                 ps->state = MAIN;
 178                 break;
 179
 180         case MAIN:
 181                 /* all fine */
 182                 break;
 183
 184         case EOL:
 185                 switch (*s) {
 186                 case ' ':
 187                 case '\t':
 188                         s++;
 189                         /* continue */
 190                         break;
 191
 192                 default:
 193                         ps->state = QUIT;
 194                         if (ps->pos != 0)
 195                                 goto newaddr;
 196                         return (0);
 197                 }
 198
 199         case QUIT:
 200                 return (0);
 201         }
 202
 203         for (; *s != 0; s++) {
 204                 if (ps->esc) {
 205                         ps->esc = 0;
 206
 207                         switch (*s) {
 208                         case '\r':
 209                         case '\n':
 210                                 goto err;
 211
 212                         default:
 213                                 goto copy;
 214                         }
 215                 }
 216
 217                 if (ps->quote) {
 218                         switch (*s) {
 219                         case '"':
 220                                 ps->quote = 0;
 221                                 goto copy;
 222
 223                         case '\\':
 224                                 ps->esc = 1;
 225                                 goto copy;
 226
 227                         case '\r':
 228                         case '\n':
 229                                 goto eol;
 230
 231                         default:
 232                                 goto copy;
 233                         }
 234                 }
 235
 236                 switch (*s) {
 237                 case '(':
 238                         ps->comment++;
 239                         break;
 240
 241                 case ')':
 242                         if (ps->comment)
 243                                 ps->comment--;
 244                         else
 245                                 goto err;
 246                         goto skip;
 247
 248                 case '"':
 249                         ps->quote = 1;
 250                         goto copy;
 251
 252                 case '\\':
 253                         ps->esc = 1;
 254                         goto copy;
 255
 256                 case '\r':
 257                 case '\n':
 258                         goto eol;
 259                 }
 260
 261                 if (ps->comment)
 262                         goto skip;
 263
 264                 switch (*s) {
 265                 case ' ':
 266                 case '\t':
 267                         /* ignore whitespace */
 268                         goto skip;
 269
 270                 case '<':
 271                         ps->brackets = 1;
 272                         goto skip;
 273
 274                 case '>':
 275                         if (!ps->brackets)
 276                                 goto err;
 277                         ps->brackets = 0;
 278
 279                         s++;
 280                         goto newaddr;
 281
 282                 case ':':
 283                         /* group - ignore */
 284                         ps->pos = 0;
 285                         goto skip;
 286
 287                 case ',':
 288                 case ';':
 289                         s++;
 290                         goto newaddr;
 291
 292                 default:
 293                         goto copy;
 294                 }
 295
 296 copy:
 297                 if (ps->comment)
 298                         goto skip;
 299
 300                 if (ps->pos + 1 == sizeof(ps->addr))
 301                         goto err;
 302                 ps->addr[ps->pos++] = *s;
 303
 304 skip:
 305                 ;
 306         }
 307
 308 eol:
 309         ps->state = EOL;
 310         return (0);
 311
 312 err:
 313         ps->state = QUIT;
 314         return (-1);
 315
 316 newaddr:
 317         ps->addr[ps->pos] = 0;
 318         ps->pos = 0;
 319         addr = strdup(ps->addr);
 320         if (addr == NULL)
 321                 errlog(1, NULL);
 322
 323         add_recp(queue, addr, 1);
 324         goto again;
 325 }
 326
 327 int
 328 readmail(struct queue *queue, int nodot, int recp_from_header)
 329 {
 330         struct parse_state parse_state;
 331         char line[1000];        /* by RFC2822 */
 332         size_t linelen;
 333         size_t error;
 334         int had_headers = 0;
 335         int had_from = 0;
 336         int had_messagid = 0;
 337         int had_date = 0;
 338         int nocopy = 0;
 339
 340         parse_state.state = NONE;
 341
 342         error = fprintf(queue->mailf,
 343                 "Received: from %s (uid %d)\n"
 344                 "\t(envelope-from %s)\n"
 345                 "\tid %s\n"
 346                 "\tby %s (%s)\n"
 347                 "\t%s\n",
 348                 username, getuid(),
 349                 queue->sender,
 350                 queue->id,
 351                 hostname(), VERSION,
 352                 rfc822date());
 353         if ((ssize_t)error < 0)
 354                 return (-1);
 355
 356         while (!feof(stdin)) {
 357                 if (fgets(line, sizeof(line), stdin) == NULL)
 358                         break;
 359                 linelen = strlen(line);
 360                 if (linelen == 0 || line[linelen - 1] != '\n') {
 361                         errno = EINVAL;         /* XXX mark permanent errors */
 362                         return (-1);
 363                 }
 364                 if (!had_headers) {
 365                         /*
 366                          * Unless this is a continuation, switch of
 367                          * the Bcc: nocopy flag.
 368                          */
 369                         if (!(line[0] == ' ' || line[0] == '\t'))
 370                                 nocopy = 0;
 371
 372                         if (strprefixcmp(line, "Date:") == 0)
 373                                 had_date = 1;
 374                         else if (strprefixcmp(line, "Message-Id:") == 0)
 375                                 had_messagid = 1;
 376                         else if (strprefixcmp(line, "From:") == 0)
 377                                 had_from = 1;
 378                         else if (strprefixcmp(line, "Bcc:") == 0)
 379                                 nocopy = 1;
 380
 381                         if (parse_state.state != NONE) {
 382                                 if (parse_addrs(&parse_state, line, queue) < 0) {
 383                                         errlogx(1, "invalid address in header\n");
 384                                         /* NOTREACHED */
 385                                 }
 386                         }
 387
 388                         if (recp_from_header && (
 389                                         strprefixcmp(line, "To:") == 0 ||
 390                                         strprefixcmp(line, "Cc:") == 0 ||
 391                                         strprefixcmp(line, "Bcc:") == 0)) {
 392                                 parse_state.state = START;
 393                                 if (parse_addrs(&parse_state, line, queue) < 0) {
 394                                         errlogx(1, "invalid address in header\n");
 395                                         /* NOTREACHED */
 396                                 }
 397                         }
 398                 }
 399
 400                 if (strcmp(line, "\n") == 0 && !had_headers) {
 401                         had_headers = 1;
 402                         while (!had_date || !had_messagid || !had_from) {
 403                                 if (!had_date) {
 404                                         had_date = 1;
 405                                         snprintf(line, sizeof(line), "Date: %s\n", rfc822date());
 406                                 } else if (!had_messagid) {
 407                                         /* XXX better msgid, assign earlier and log? */
 408                                         had_messagid = 1;
 409                                         snprintf(line, sizeof(line), "Message-Id: <%s@%s>\n",
 410                                                  queue->id, hostname());
 411                                 } else if (!had_from) {
 412                                         had_from = 1;
 413                                         snprintf(line, sizeof(line), "From: <%s>\n", queue->sender);
 414                                 }
 415                                 if (fwrite(line, strlen(line), 1, queue->mailf) != 1)
 416                                         return (-1);
 417                         }
 418                         strcpy(line, "\n");
 419                 }
 420                 if (!nodot && linelen == 2 && line[0] == '.')
 421                         break;
 422                 if (!nocopy) {
 423                         if (fwrite(line, strlen(line), 1, queue->mailf) != 1)
 424                                 return (-1);
 425                 }
 426         }
 427
 428         return (0);
 429 }