libexec/dma/mail.c

   1 /*
   2  * Copyright (c) 2008-2014, Simon Schubert <2@0x2c.org>.
   3  * Copyright (c) 2008 The DragonFly Project.  All rights reserved.
   4  *
   5  * This code is derived from software contributed to The DragonFly Project
   6  * by Simon Schubert <2@0x2c.org>.
   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
  36 #include <errno.h>
  37 #include <inttypes.h>
  38 #include <signal.h>
  39 #include <syslog.h>
  40 #include <unistd.h>
  41
  42 #include "dma.h"
  43
  44 void
  45 bounce(struct qitem *it, const char *reason)
  46 {
  47         struct queue bounceq;
  48         char line[1000];
  49         size_t pos;
  50         int error;
  51
  52         /* Don't bounce bounced mails */
  53         if (it->sender[0] == 0) {
  54                 syslog(LOG_INFO, "can not bounce a bounce message, discarding");
  55                 exit(1);
  56         }
  57
  58         bzero(&bounceq, sizeof(bounceq));
  59         LIST_INIT(&bounceq.queue);
  60         bounceq.sender = "";
  61         if (add_recp(&bounceq, it->sender, EXPAND_WILDCARD) != 0)
  62                 goto fail;
  63
  64         if (newspoolf(&bounceq) != 0)
  65                 goto fail;
  66
  67         syslog(LOG_ERR, "delivery failed, bouncing as %s", bounceq.id);
  68         setlogident("%s", bounceq.id);
  69
  70         error = fprintf(bounceq.mailf,
  71                 "Received: from MAILER-DAEMON\n"
  72                 "\tid %s\n"
  73                 "\tby %s (%s);\n"
  74                 "\t%s\n"
  75                 "X-Original-To: <%s>\n"
  76                 "From: MAILER-DAEMON <>\n"
  77                 "To: %s\n"
  78                 "Subject: Mail delivery failed\n"
  79                 "Message-Id: <%s@%s>\n"
  80                 "Date: %s\n"
  81                 "\n"
  82                 "This is the %s at %s.\n"
  83                 "\n"
  84                 "There was an error delivering your mail to <%s>.\n"
  85                 "\n"
  86                 "%s\n"
  87                 "\n"
  88                 "%s\n"
  89                 "\n",
  90                 bounceq.id,
  91                 hostname(), VERSION,
  92                 rfc822date(),
  93                 it->addr,
  94                 it->sender,
  95                 bounceq.id, hostname(),
  96                 rfc822date(),
  97                 VERSION, hostname(),
  98                 it->addr,
  99                 reason,
 100                 config.features & FULLBOUNCE ?
 101                     "Original message follows." :
 102                     "Message headers follow.");
 103         if (error < 0)
 104                 goto fail;
 105
 106         if (fseek(it->mailf, 0, SEEK_SET) != 0)
 107                 goto fail;
 108         if (config.features & FULLBOUNCE) {
 109                 while ((pos = fread(line, 1, sizeof(line), it->mailf)) > 0) {
 110                         if (fwrite(line, 1, pos, bounceq.mailf) != pos)
 111                                 goto fail;
 112                 }
 113         } else {
 114                 while (!feof(it->mailf)) {
 115                         if (fgets(line, sizeof(line), it->mailf) == NULL)
 116                                 break;
 117                         if (line[0] == '\n')
 118                                 break;
 119                         if (fwrite(line, strlen(line), 1, bounceq.mailf) != 1)
 120                                 goto fail;
 121                 }
 122         }
 123
 124         if (linkspool(&bounceq) != 0)
 125                 goto fail;
 126         /* bounce is safe */
 127
 128         delqueue(it);
 129
 130         run_queue(&bounceq);
 131         /* NOTREACHED */
 132
 133 fail:
 134         syslog(LOG_CRIT, "error creating bounce: %m");
 135         delqueue(it);
 136         exit(1);
 137 }
 138
 139 struct parse_state {
 140         char addr[1000];
 141         int pos;
 142
 143         enum {
 144                 NONE = 0,
 145                 START,
 146                 MAIN,
 147                 EOL,
 148                 QUIT
 149         } state;
 150         int comment;
 151         int quote;
 152         int brackets;
 153         int esc;
 154 };
 155
 156 /*
 157  * Simplified RFC2822 header/address parsing.
 158  * We copy escapes and quoted strings directly, since
 159  * we have to pass them like this to the mail server anyways.
 160  * XXX local addresses will need treatment
 161  */
 162 static int
 163 parse_addrs(struct parse_state *ps, char *s, struct queue *queue)
 164 {
 165         char *addr;
 166
 167 again:
 168         switch (ps->state) {
 169         case NONE:
 170                 return (-1);
 171
 172         case START:
 173                 /* init our data */
 174                 bzero(ps, sizeof(*ps));
 175
 176                 /* skip over header name */
 177                 while (*s != ':')
 178                         s++;
 179                 s++;
 180                 ps->state = MAIN;
 181                 break;
 182
 183         case MAIN:
 184                 /* all fine */
 185                 break;
 186
 187         case EOL:
 188                 switch (*s) {
 189                 case ' ':
 190                 case '\t':
 191                         s++;
 192                         /* continue */
 193                         break;
 194
 195                 default:
 196                         ps->state = QUIT;
 197                         if (ps->pos != 0)
 198                                 goto newaddr;
 199                         return (0);
 200                 }
 201                 /* FALLTHROUGH */
 202
 203         case QUIT:
 204                 return (0);
 205         }
 206
 207         for (; *s != 0; s++) {
 208                 if (ps->esc) {
 209                         ps->esc = 0;
 210
 211                         switch (*s) {
 212                         case '\r':
 213                         case '\n':
 214                                 goto err;
 215
 216                         default:
 217                                 goto copy;
 218                         }
 219                 }
 220
 221                 if (ps->quote) {
 222                         switch (*s) {
 223                         case '"':
 224                                 ps->quote = 0;
 225                                 goto copy;
 226
 227                         case '\\':
 228                                 ps->esc = 1;
 229                                 goto copy;
 230
 231                         case '\r':
 232                         case '\n':
 233                                 goto eol;
 234
 235                         default:
 236                                 goto copy;
 237                         }
 238                 }
 239
 240                 switch (*s) {
 241                 case '(':
 242                         ps->comment++;
 243                         break;
 244
 245                 case ')':
 246                         if (ps->comment)
 247                                 ps->comment--;
 248                         else
 249                                 goto err;
 250                         goto skip;
 251
 252                 case '"':
 253                         ps->quote = 1;
 254                         goto copy;
 255
 256                 case '\\':
 257                         ps->esc = 1;
 258                         goto copy;
 259
 260                 case '\r':
 261                 case '\n':
 262                         goto eol;
 263                 }
 264
 265                 if (ps->comment)
 266                         goto skip;
 267
 268                 switch (*s) {
 269                 case ' ':
 270                 case '\t':
 271                         /* ignore whitespace */
 272                         goto skip;
 273
 274                 case '<':
 275                         /* this is the real address now */
 276                         ps->brackets = 1;
 277                         ps->pos = 0;
 278                         goto skip;
 279
 280                 case '>':
 281                         if (!ps->brackets)
 282                                 goto err;
 283                         ps->brackets = 0;
 284
 285                         s++;
 286                         goto newaddr;
 287
 288                 case ':':
 289                         /* group - ignore */
 290                         ps->pos = 0;
 291                         goto skip;
 292
 293                 case ',':
 294                 case ';':
 295                         /*
 296                          * Next address, copy previous one.
 297                          * However, we might be directly after
 298                          * a <address>, or have two consecutive
 299                          * commas.
 300                          * Skip the comma unless there is
 301                          * really something to copy.
 302                          */
 303                         if (ps->pos == 0)
 304                                 goto skip;
 305                         s++;
 306                         goto newaddr;
 307
 308                 default:
 309                         goto copy;
 310                 }
 311
 312 copy:
 313                 if (ps->comment)
 314                         goto skip;
 315
 316                 if (ps->pos + 1 == sizeof(ps->addr))
 317                         goto err;
 318                 ps->addr[ps->pos++] = *s;
 319
 320 skip:
 321                 ;
 322         }
 323
 324 eol:
 325         ps->state = EOL;
 326         return (0);
 327
 328 err:
 329         ps->state = QUIT;
 330         return (-1);
 331
 332 newaddr:
 333         ps->addr[ps->pos] = 0;
 334         ps->pos = 0;
 335         addr = strdup(ps->addr);
 336         if (addr == NULL)
 337                 errlog(1, NULL);
 338
 339         if (add_recp(queue, addr, EXPAND_WILDCARD) != 0)
 340                 errlogx(1, "invalid recipient `%s'", addr);
 341
 342         goto again;
 343 }
 344
 345 int
 346 readmail(struct queue *queue, int nodot, int recp_from_header)
 347 {
 348         struct parse_state parse_state;
 349         char line[1000];        /* by RFC2822 */
 350         size_t linelen;
 351         size_t error;
 352         int had_headers = 0;
 353         int had_from = 0;
 354         int had_messagid = 0;
 355         int had_date = 0;
 356         int had_last_line = 0;
 357         int nocopy = 0;
 358
 359         parse_state.state = NONE;
 360
 361         error = fprintf(queue->mailf,
 362                 "Received: from %s (uid %d)\n"
 363                 "\t(envelope-from %s)\n"
 364                 "\tid %s\n"
 365                 "\tby %s (%s);\n"
 366                 "\t%s\n",
 367                 username, useruid,
 368                 queue->sender,
 369                 queue->id,
 370                 hostname(), VERSION,
 371                 rfc822date());
 372         if ((ssize_t)error < 0)
 373                 return (-1);
 374
 375         while (!feof(stdin)) {
 376                 if (fgets(line, sizeof(line) - 1, stdin) == NULL)
 377                         break;
 378                 if (had_last_line)
 379                         errlogx(1, "bad mail input format:"
 380                                 " from %s (uid %d) (envelope-from %s)",
 381                                 username, useruid, queue->sender);
 382                 linelen = strlen(line);
 383                 if (linelen == 0 || line[linelen - 1] != '\n') {
 384                         /*
 385                          * This line did not end with a newline character.
 386                          * If we fix it, it better be the last line of
 387                          * the file.
 388                          */
 389                         line[linelen] = '\n';
 390                         line[linelen + 1] = 0;
 391                         had_last_line = 1;
 392                 }
 393                 if (!had_headers) {
 394                         /*
 395                          * Unless this is a continuation, switch of
 396                          * the Bcc: nocopy flag.
 397                          */
 398                         if (!(line[0] == ' ' || line[0] == '\t'))
 399                                 nocopy = 0;
 400
 401                         if (strprefixcmp(line, "Date:") == 0)
 402                                 had_date = 1;
 403                         else if (strprefixcmp(line, "Message-Id:") == 0)
 404                                 had_messagid = 1;
 405                         else if (strprefixcmp(line, "From:") == 0)
 406                                 had_from = 1;
 407                         else if (strprefixcmp(line, "Bcc:") == 0)
 408                                 nocopy = 1;
 409
 410                         if (parse_state.state != NONE) {
 411                                 if (parse_addrs(&parse_state, line, queue) < 0) {
 412                                         errlogx(1, "invalid address in header\n");
 413                                         /* NOTREACHED */
 414                                 }
 415                         }
 416
 417                         if (recp_from_header && (
 418                                         strprefixcmp(line, "To:") == 0 ||
 419                                         strprefixcmp(line, "Cc:") == 0 ||
 420                                         strprefixcmp(line, "Bcc:") == 0)) {
 421                                 parse_state.state = START;
 422                                 if (parse_addrs(&parse_state, line, queue) < 0) {
 423                                         errlogx(1, "invalid address in header\n");
 424                                         /* NOTREACHED */
 425                                 }
 426                         }
 427                 }
 428
 429                 if (strcmp(line, "\n") == 0 && !had_headers) {
 430                         had_headers = 1;
 431                         while (!had_date || !had_messagid || !had_from) {
 432                                 if (!had_date) {
 433                                         had_date = 1;
 434                                         snprintf(line, sizeof(line), "Date: %s\n", rfc822date());
 435                                 } else if (!had_messagid) {
 436                                         /* XXX msgid, assign earlier and log? */
 437                                         had_messagid = 1;
 438                                         snprintf(line, sizeof(line), "Message-Id: <%"PRIxMAX".%s.%"PRIxMAX"@%s>\n",
 439                                                  (uintmax_t)time(NULL),
 440                                                  queue->id,
 441                                                  (uintmax_t)random(),
 442                                                  hostname());
 443                                 } else if (!had_from) {
 444                                         had_from = 1;
 445                                         snprintf(line, sizeof(line), "From: <%s>\n", queue->sender);
 446                                 }
 447                                 if (fwrite(line, strlen(line), 1, queue->mailf) != 1)
 448                                         return (-1);
 449                         }
 450                         strcpy(line, "\n");
 451                 }
 452                 if (!nodot && linelen == 2 && line[0] == '.')
 453                         break;
 454                 if (!nocopy) {
 455                         if (fwrite(line, strlen(line), 1, queue->mailf) != 1)
 456                                 return (-1);
 457                 }
 458         }
 459
 460         return (0);
 461 }