src/src/transports/lmtp.c

   1 /*************************************************
   2 *     Exim - an Internet mail transport agent    *
   3 *************************************************/
   4
   5 /* Copyright (c) University of Cambridge 1995 - 2014 */
   6 /* See the file NOTICE for conditions of use and distribution. */
   7
   8
   9 #include "../exim.h"
  10 #include "lmtp.h"
  11
  12 #define PENDING_OK 256
  13
  14
  15 /* Options specific to the lmtp transport. They must be in alphabetic
  16 order (note that "_" comes before the lower case letters). Those starting
  17 with "*" are not settable by the user but are used by the option-reading
  18 software for alternative value types. Some options are stored in the transport
  19 instance block so as to be publicly visible; these are flagged with opt_public.
  20 */
  21
  22 optionlist lmtp_transport_options[] = {
  23   { "batch_id",          opt_stringptr | opt_public,
  24       (void *)offsetof(transport_instance, batch_id) },
  25   { "batch_max",         opt_int | opt_public,
  26       (void *)offsetof(transport_instance, batch_max) },
  27   { "command",           opt_stringptr,
  28       (void *)offsetof(lmtp_transport_options_block, cmd) },
  29   { "ignore_quota",      opt_bool,
  30       (void *)offsetof(lmtp_transport_options_block, ignore_quota) },
  31   { "socket",            opt_stringptr,
  32       (void *)offsetof(lmtp_transport_options_block, skt) },
  33   { "timeout",           opt_time,
  34       (void *)offsetof(lmtp_transport_options_block, timeout) }
  35 };
  36
  37 /* Size of the options list. An extern variable has to be used so that its
  38 address can appear in the tables drtables.c. */
  39
  40 int lmtp_transport_options_count =
  41   sizeof(lmtp_transport_options)/sizeof(optionlist);
  42
  43 /* Default private options block for the lmtp transport. */
  44
  45 lmtp_transport_options_block lmtp_transport_option_defaults = {
  46   NULL,           /* cmd */
  47   NULL,           /* skt */
  48   5*60,           /* timeout */
  49   0,              /* options */
  50   FALSE           /* ignore_quota */
  51 };
  52
  53
  54
  55 /*************************************************
  56 *          Initialization entry point            *
  57 *************************************************/
  58
  59 /* Called for each instance, after its options have been read, to
  60 enable consistency checks to be done, or anything else that needs
  61 to be set up. */
  62
  63 void
  64 lmtp_transport_init(transport_instance *tblock)
  65 {
  66 lmtp_transport_options_block *ob =
  67   (lmtp_transport_options_block *)(tblock->options_block);
  68
  69 /* Either the command field or the socket field must be set */
  70
  71 if ((ob->cmd == NULL) == (ob->skt == NULL))
  72   log_write(0, LOG_PANIC_DIE|LOG_CONFIG,
  73     "one (and only one) of command or socket must be set for the %s transport",
  74     tblock->name);
  75
  76 /* If a fixed uid field is set, then a gid field must also be set. */
  77
  78 if (tblock->uid_set && !tblock->gid_set && tblock->expand_gid == NULL)
  79   log_write(0, LOG_PANIC_DIE|LOG_CONFIG,
  80     "user set without group for the %s transport", tblock->name);
  81
  82 /* Set up the bitwise options for transport_write_message from the various
  83 driver options. Only one of body_only and headers_only can be set. */
  84
  85 ob->options |=
  86   (tblock->body_only? topt_no_headers : 0) |
  87   (tblock->headers_only? topt_no_body : 0) |
  88   (tblock->return_path_add? topt_add_return_path : 0) |
  89   (tblock->delivery_date_add? topt_add_delivery_date : 0) |
  90   (tblock->envelope_to_add? topt_add_envelope_to : 0) |
  91   topt_use_crlf | topt_end_dot;
  92 }
  93
  94
  95 /*************************************************
  96 *          Check an LMTP response                *
  97 *************************************************/
  98
  99 /* This function is given an errno code and the LMTP response buffer to
 100 analyse. It sets an appropriate message and puts the first digit of the
 101 response code into the yield variable. If no response was actually read, a
 102 suitable digit is chosen.
 103
 104 Arguments:
 105   errno_value  pointer to the errno value
 106   more_errno   from the top address for use with ERRNO_FILTER_FAIL
 107   buffer       the LMTP response buffer
 108   yield        where to put a one-digit LMTP response code
 109   message      where to put an errror message
 110
 111 Returns:       TRUE if a "QUIT" command should be sent, else FALSE
 112 */
 113
 114 static BOOL check_response(int *errno_value, int more_errno, uschar *buffer,
 115   int *yield, uschar **message)
 116 {
 117 *yield = '4';    /* Default setting is to give a temporary error */
 118
 119 /* Handle response timeout */
 120
 121 if (*errno_value == ETIMEDOUT)
 122   {
 123   *message = string_sprintf("LMTP timeout after %s", big_buffer);
 124   if (transport_count > 0)
 125     *message = string_sprintf("%s (%d bytes written)", *message,
 126       transport_count);
 127   *errno_value = 0;
 128   return FALSE;
 129   }
 130
 131 /* Handle malformed LMTP response */
 132
 133 if (*errno_value == ERRNO_SMTPFORMAT)
 134   {
 135   *message = string_sprintf("Malformed LMTP response after %s: %s",
 136     big_buffer, string_printing(buffer));
 137   return FALSE;
 138   }
 139
 140 /* Handle a failed filter process error; can't send QUIT as we mustn't
 141 end the DATA. */
 142
 143 if (*errno_value == ERRNO_FILTER_FAIL)
 144   {
 145   *message = string_sprintf("transport filter process failed (%d)%s",
 146     more_errno,
 147     (more_errno == EX_EXECFAILED)? ": unable to execute command" : "");
 148   return FALSE;
 149   }
 150
 151 /* Handle a failed add_headers expansion; can't send QUIT as we mustn't
 152 end the DATA. */
 153
 154 if (*errno_value == ERRNO_CHHEADER_FAIL)
 155   {
 156   *message =
 157     string_sprintf("failed to expand headers_add or headers_remove: %s",
 158       expand_string_message);
 159   return FALSE;
 160   }
 161
 162 /* Handle failure to write a complete data block */
 163
 164 if (*errno_value == ERRNO_WRITEINCOMPLETE)
 165   {
 166   *message = string_sprintf("failed to write a data block");
 167   return FALSE;
 168   }
 169
 170 /* Handle error responses from the remote process. */
 171
 172 if (buffer[0] != 0)
 173   {
 174   uschar *s = string_printing(buffer);
 175   *message = string_sprintf("LMTP error after %s: %s", big_buffer, s);
 176   *yield = buffer[0];
 177   return TRUE;
 178   }
 179
 180 /* No data was read. If there is no errno, this must be the EOF (i.e.
 181 connection closed) case, which causes deferral. Otherwise, leave the errno
 182 value to be interpreted. In all cases, we have to assume the connection is now
 183 dead. */
 184
 185 if (*errno_value == 0)
 186   {
 187   *errno_value = ERRNO_SMTPCLOSED;
 188   *message = string_sprintf("LMTP connection closed after %s", big_buffer);
 189   }
 190
 191 return FALSE;
 192 }
 193
 194
 195
 196 /*************************************************
 197 *             Write LMTP command                 *
 198 *************************************************/
 199
 200 /* The formatted command is left in big_buffer so that it can be reflected in
 201 any error message.
 202
 203 Arguments:
 204   fd         the fd to write to
 205   format     a format, starting with one of
 206              of HELO, MAIL FROM, RCPT TO, DATA, ".", or QUIT.
 207   ...        data for the format
 208
 209 Returns:     TRUE if successful, FALSE if not, with errno set
 210 */
 211
 212 static BOOL
 213 lmtp_write_command(int fd, const char *format, ...)
 214 {
 215 int count, rc;
 216 va_list ap;
 217 va_start(ap, format);
 218 if (!string_vformat(big_buffer, big_buffer_size, CS format, ap))
 219   {
 220   errno = ERRNO_SMTPFORMAT;
 221   return FALSE;
 222   }
 223 va_end(ap);
 224 count = Ustrlen(big_buffer);
 225 DEBUG(D_transport|D_v) debug_printf("  LMTP>> %s", big_buffer);
 226 rc = write(fd, big_buffer, count);
 227 big_buffer[count-2] = 0;     /* remove \r\n for debug and error message */
 228 if (rc > 0) return TRUE;
 229 DEBUG(D_transport) debug_printf("write failed: %s\n", strerror(errno));
 230 return FALSE;
 231 }
 232
 233
 234
 235
 236 /*************************************************
 237 *              Read LMTP response                *
 238 *************************************************/
 239
 240 /* This function reads an LMTP response with a timeout, and returns the
 241 response in the given buffer. It also analyzes the first digit of the reply
 242 code and returns FALSE if it is not acceptable.
 243
 244 FALSE is also returned after a reading error. In this case buffer[0] will be
 245 zero, and the error code will be in errno.
 246
 247 Arguments:
 248   f         a file to read from
 249   buffer    where to put the response
 250   size      the size of the buffer
 251   okdigit   the expected first digit of the response
 252   timeout   the timeout to use
 253
 254 Returns:    TRUE if a valid, non-error response was received; else FALSE
 255 */
 256
 257 static BOOL
 258 lmtp_read_response(FILE *f, uschar *buffer, int size, int okdigit, int timeout)
 259 {
 260 int count;
 261 uschar *ptr = buffer;
 262 uschar *readptr = buffer;
 263
 264 /* Ensure errno starts out zero */
 265
 266 errno = 0;
 267
 268 /* Loop for handling LMTP responses that do not all come in one line. */
 269
 270 for (;;)
 271   {
 272   /* If buffer is too full, something has gone wrong. */
 273
 274   if (size < 10)
 275     {
 276     *readptr = 0;
 277     errno = ERRNO_SMTPFORMAT;
 278     return FALSE;
 279     }
 280
 281   /* Loop to cover the read getting interrupted. */
 282
 283   for (;;)
 284     {
 285     char *rc;
 286     int save_errno;
 287
 288     *readptr = 0;           /* In case nothing gets read */
 289     sigalrm_seen = FALSE;
 290     alarm(timeout);
 291     rc = Ufgets(readptr, size-1, f);
 292     save_errno = errno;
 293     alarm(0);
 294     errno = save_errno;
 295
 296     if (rc != NULL) break;  /* A line has been read */
 297
 298     /* Handle timeout; must do this first because it uses EINTR */
 299
 300     if (sigalrm_seen) errno = ETIMEDOUT;
 301
 302     /* If some other interrupt arrived, just retry. We presume this to be rare,
 303     but it can happen (e.g. the SIGUSR1 signal sent by exiwhat causes
 304     read() to exit). */
 305
 306     else if (errno == EINTR)
 307       {
 308       DEBUG(D_transport) debug_printf("EINTR while reading LMTP response\n");
 309       continue;
 310       }
 311
 312     /* Handle other errors, including EOF; ensure buffer is completely empty. */
 313
 314     buffer[0] = 0;
 315     return FALSE;
 316     }
 317
 318   /* Adjust size in case we have to read another line, and adjust the
 319   count to be the length of the line we are about to inspect. */
 320
 321   count = Ustrlen(readptr);
 322   size -= count;
 323   count += readptr - ptr;
 324
 325   /* See if the final two characters in the buffer are \r\n. If not, we
 326   have to read some more. At least, that is what we should do on a strict
 327   interpretation of the RFC. But accept LF as well, as we do for SMTP. */
 328
 329   if (ptr[count-1] != '\n')
 330     {
 331     DEBUG(D_transport)
 332       {
 333       int i;
 334       debug_printf("LMTP input line incomplete in one buffer:\n  ");
 335       for (i = 0; i < count; i++)
 336         {
 337         int c = (ptr[i]);
 338         if (mac_isprint(c)) debug_printf("%c", c); else debug_printf("<%d>", c);
 339         }
 340       debug_printf("\n");
 341       }
 342     readptr = ptr + count;
 343     continue;
 344     }
 345
 346   /* Remove any whitespace at the end of the buffer. This gets rid of CR, LF
 347   etc. at the end. Show it, if debugging, formatting multi-line responses. */
 348
 349   while (count > 0 && isspace(ptr[count-1])) count--;
 350   ptr[count] = 0;
 351
 352   DEBUG(D_transport|D_v)
 353     {
 354     uschar *s = ptr;
 355     uschar *t = ptr;
 356     while (*t != 0)
 357       {
 358       while (*t != 0 && *t != '\n') t++;
 359       debug_printf("  %s %*s\n", (s == ptr)? "LMTP<<" : "      ",
 360         (int)(t-s), s);
 361       if (*t == 0) break;
 362       s = t = t + 1;
 363       }
 364     }
 365
 366   /* Check the format of the response: it must start with three digits; if
 367   these are followed by a space or end of line, the response is complete. If
 368   they are followed by '-' this is a multi-line response and we must look for
 369   another line until the final line is reached. The only use made of multi-line
 370   responses is to pass them back as error messages. We therefore just
 371   concatenate them all within the buffer, which should be large enough to
 372   accept any reasonable number of lines. A multiline response may already
 373   have been read in one go - hence the loop here. */
 374
 375   for(;;)
 376     {
 377     uschar *p;
 378     if (count < 3 ||
 379        !isdigit(ptr[0]) ||
 380        !isdigit(ptr[1]) ||
 381        !isdigit(ptr[2]) ||
 382        (ptr[3] != '-' && ptr[3] != ' ' && ptr[3] != 0))
 383       {
 384       errno = ERRNO_SMTPFORMAT;    /* format error */
 385       return FALSE;
 386       }
 387
 388     /* If a single-line response, exit the loop */
 389
 390     if (ptr[3] != '-') break;
 391
 392     /* For a multi-line response see if the next line is already read, and if
 393     so, stay in this loop to check it. */
 394
 395     p = ptr + 3;
 396     while (*(++p) != 0)
 397       {
 398       if (*p == '\n')
 399         {
 400         ptr = ++p;
 401         break;
 402         }
 403       }
 404     if (*p == 0) break;   /* No more lines to check */
 405     }
 406
 407   /* End of response. If the last of the lines we are looking at is the final
 408   line, we are done. Otherwise more data has to be read. */
 409
 410   if (ptr[3] != '-') break;
 411
 412   /* Move the reading pointer upwards in the buffer and insert \n in case this
 413   is an error message that subsequently gets printed. Set the scanning pointer
 414   to the reading pointer position. */
 415
 416   ptr += count;
 417   *ptr++ = '\n';
 418   size--;
 419   readptr = ptr;
 420   }
 421
 422 /* Return a value that depends on the LMTP return code. Ensure that errno is
 423 zero, because the caller of this function looks at errno when FALSE is
 424 returned, to distinguish between an unexpected return code and other errors
 425 such as timeouts, lost connections, etc. */
 426
 427 errno = 0;
 428 return buffer[0] == okdigit;
 429 }
 430
 431
 432
 433
 434
 435
 436 /*************************************************
 437 *              Main entry point                  *
 438 *************************************************/
 439
 440 /* See local README for interface details. For setup-errors, this transport
 441 returns FALSE, indicating that the first address has the status for all; in
 442 normal cases it returns TRUE, indicating that each address has its own status
 443 set. */
 444
 445 BOOL
 446 lmtp_transport_entry(
 447   transport_instance *tblock,      /* data for this instantiation */
 448   address_item *addrlist)          /* address(es) we are working on */
 449 {
 450 pid_t pid = 0;
 451 FILE *out;
 452 lmtp_transport_options_block *ob =
 453   (lmtp_transport_options_block *)(tblock->options_block);
 454 struct sockaddr_un sockun;         /* don't call this "sun" ! */
 455 int timeout = ob->timeout;
 456 int fd_in = -1, fd_out = -1;
 457 int code, save_errno;
 458 BOOL send_data;
 459 BOOL yield = FALSE;
 460 address_item *addr;
 461 uschar *igquotstr = US"";
 462 uschar *sockname = NULL;
 463 uschar **argv;
 464 uschar buffer[256];
 465
 466 DEBUG(D_transport) debug_printf("%s transport entered\n", tblock->name);
 467
 468 /* Initialization ensures that either a command or a socket is specified, but
 469 not both. When a command is specified, call the common function for creating an
 470 argument list and expanding the items. */
 471
 472 if (ob->cmd != NULL)
 473   {
 474   DEBUG(D_transport) debug_printf("using command %s\n", ob->cmd);
 475   sprintf(CS buffer, "%.50s transport", tblock->name);
 476   if (!transport_set_up_command(&argv, ob->cmd, TRUE, PANIC, addrlist, buffer,
 477        NULL))
 478     return FALSE;
 479   }
 480
 481 /* When a socket is specified, expand the string and create a socket. */
 482
 483 else
 484   {
 485   DEBUG(D_transport) debug_printf("using socket %s\n", ob->skt);
 486   sockname = expand_string(ob->skt);
 487   if (sockname == NULL)
 488     {
 489     addrlist->message = string_sprintf("Expansion of \"%s\" (socket setting "
 490       "for %s transport) failed: %s", ob->skt, tblock->name,
 491       expand_string_message);
 492     return FALSE;
 493     }
 494   if ((fd_in = fd_out = socket(PF_UNIX, SOCK_STREAM, 0)) == -1)
 495     {
 496     addrlist->message = string_sprintf(
 497       "Failed to create socket %s for %s transport: %s",
 498         ob->skt, tblock->name, strerror(errno));
 499     return FALSE;
 500     }
 501   }
 502
 503 /* If the -N option is set, can't do any more. Presume all has gone well. */
 504
 505 if (dont_deliver)
 506   {
 507   DEBUG(D_transport)
 508     debug_printf("*** delivery by %s transport bypassed by -N option",
 509       tblock->name);
 510   addrlist->transport_return = OK;
 511   return FALSE;
 512   }
 513
 514 /* As this is a local transport, we are already running with the required
 515 uid/gid and current directory. Request that the new process be a process group
 516 leader, so we can kill it and all its children on an error. */
 517
 518 if (ob->cmd != NULL)
 519   {
 520   if ((pid = child_open(argv, NULL, 0, &fd_in, &fd_out, TRUE)) < 0)
 521     {
 522     addrlist->message = string_sprintf(
 523       "Failed to create child process for %s transport: %s", tblock->name,
 524         strerror(errno));
 525     return FALSE;
 526     }
 527   }
 528
 529 /* For a socket, try to make the connection */
 530
 531 else
 532   {
 533   sockun.sun_family = AF_UNIX;
 534   sprintf(sockun.sun_path, "%.*s", (int)(sizeof(sockun.sun_path)-1), sockname);
 535   if(connect(fd_out, (struct sockaddr *)(&sockun), sizeof(sockun)) == -1)
 536     {
 537     addrlist->message = string_sprintf(
 538       "Failed to connect to socket %s for %s transport: %s",
 539         sockun.sun_path, tblock->name, strerror(errno));
 540     return FALSE;
 541     }
 542   }
 543
 544 /* Make the output we are going to read into a file. */
 545
 546 out = fdopen(fd_out, "rb");
 547
 548 /* Now we must implement the LMTP protocol. It is like SMTP, except that after
 549 the end of the message, a return code for every accepted RCPT TO is sent. This
 550 allows for message+recipient checks after the message has been received. */
 551
 552 /* First thing is to wait for an initial greeting. */
 553
 554 Ustrcpy(big_buffer, "initial connection");
 555 if (!lmtp_read_response(out, buffer, sizeof(buffer), '2',
 556   timeout)) goto RESPONSE_FAILED;
 557
 558 /* Next, we send a LHLO command, and expect a positive response */
 559
 560 if (!lmtp_write_command(fd_in, "%s %s\r\n", "LHLO",
 561   primary_hostname)) goto WRITE_FAILED;
 562
 563 if (!lmtp_read_response(out, buffer, sizeof(buffer), '2',
 564      timeout)) goto RESPONSE_FAILED;
 565
 566 /* If the ignore_quota option is set, note whether the server supports the
 567 IGNOREQUOTA option, and if so, set an appropriate addition for RCPT. */
 568
 569 if (ob->ignore_quota)
 570   igquotstr = (pcre_exec(regex_IGNOREQUOTA, NULL, CS buffer,
 571     Ustrlen(CS buffer), 0, PCRE_EOPT, NULL, 0) >= 0)? US" IGNOREQUOTA" : US"";
 572
 573 /* Now the envelope sender */
 574
 575 if (!lmtp_write_command(fd_in, "MAIL FROM:<%s>\r\n", return_path))
 576   goto WRITE_FAILED;
 577
 578 if (!lmtp_read_response(out, buffer, sizeof(buffer), '2', timeout))
 579   {
 580   if (errno == 0 && buffer[0] == '4')
 581     {
 582     errno = ERRNO_MAIL4XX;
 583     addrlist->more_errno |= ((buffer[1] - '0')*10 + buffer[2] - '0') << 8;
 584     }
 585   goto RESPONSE_FAILED;
 586   }
 587
 588 /* Next, we hand over all the recipients. Some may be permanently or
 589 temporarily rejected; others may be accepted, for now. */
 590
 591 send_data = FALSE;
 592 for (addr = addrlist; addr != NULL; addr = addr->next)
 593   {
 594   if (!lmtp_write_command(fd_in, "RCPT TO:<%s>%s\r\n",
 595        transport_rcpt_address(addr, tblock->rcpt_include_affixes), igquotstr))
 596     goto WRITE_FAILED;
 597   if (lmtp_read_response(out, buffer, sizeof(buffer), '2', timeout))
 598     {
 599     send_data = TRUE;
 600     addr->transport_return = PENDING_OK;
 601     }
 602   else
 603     {
 604     if (errno != 0 || buffer[0] == 0) goto RESPONSE_FAILED;
 605     addr->message = string_sprintf("LMTP error after %s: %s", big_buffer,
 606       string_printing(buffer));
 607     setflag(addr, af_pass_message);   /* Allow message to go to user */
 608     if (buffer[0] == '5') addr->transport_return = FAIL; else
 609       {
 610       addr->basic_errno = ERRNO_RCPT4XX;
 611       addr->more_errno |= ((buffer[1] - '0')*10 + buffer[2] - '0') << 8;
 612       }
 613     }
 614   }
 615
 616 /* Now send the text of the message if there were any good recipients. */
 617
 618 if (send_data)
 619   {
 620   BOOL ok;
 621
 622   if (!lmtp_write_command(fd_in, "DATA\r\n")) goto WRITE_FAILED;
 623   if (!lmtp_read_response(out, buffer, sizeof(buffer), '3', timeout))
 624     {
 625     if (errno == 0 && buffer[0] == '4')
 626       {
 627       errno = ERRNO_DATA4XX;
 628       addrlist->more_errno |= ((buffer[1] - '0')*10 + buffer[2] - '0') << 8;
 629       }
 630     goto RESPONSE_FAILED;
 631     }
 632
 633   sigalrm_seen = FALSE;
 634   transport_write_timeout = timeout;
 635   Ustrcpy(big_buffer, "sending data block");   /* For error messages */
 636   DEBUG(D_transport|D_v)
 637     debug_printf("  LMTP>> writing message and terminating \".\"\n");
 638
 639   transport_count = 0;
 640   ok = transport_write_message(addrlist, fd_in, ob->options, 0,
 641         tblock->add_headers, tblock->remove_headers, US".", US"..",
 642         tblock->rewrite_rules, tblock->rewrite_existflags);
 643
 644   /* Failure can either be some kind of I/O disaster (including timeout),
 645   or the failure of a transport filter or the expansion of added headers. */
 646
 647   if (!ok)
 648     {
 649     buffer[0] = 0;              /* There hasn't been a response */
 650     goto RESPONSE_FAILED;
 651     }
 652
 653   Ustrcpy(big_buffer, "end of data");   /* For error messages */
 654
 655   /* We now expect a response for every address that was accepted above,
 656   in the same order. For those that get a response, their status is fixed;
 657   any that are accepted have been handed over, even if later responses crash -
 658   at least, that's how I read RFC 2033. */
 659
 660   for (addr = addrlist; addr != NULL; addr = addr->next)
 661     {
 662     if (addr->transport_return != PENDING_OK) continue;
 663
 664     if (lmtp_read_response(out, buffer, sizeof(buffer), '2', timeout))
 665       {
 666       addr->transport_return = OK;
 667       if ((log_extra_selector & LX_smtp_confirmation) != 0)
 668         {
 669         uschar *s = string_printing(buffer);
 670         addr->message = (s == buffer)? (uschar *)string_copy(s) : s;
 671         }
 672       }
 673     /* If the response has failed badly, use it for all the remaining pending
 674     addresses and give up. */
 675
 676     else if (errno != 0 || buffer[0] == 0)
 677       {
 678       address_item *a;
 679       save_errno = errno;
 680       check_response(&save_errno, addr->more_errno, buffer, &code,
 681         &(addr->message));
 682       addr->transport_return = (code == '5')? FAIL : DEFER;
 683       for (a = addr->next; a != NULL; a = a->next)
 684         {
 685         if (a->transport_return != PENDING_OK) continue;
 686         a->basic_errno = addr->basic_errno;
 687         a->message = addr->message;
 688         a->transport_return = addr->transport_return;
 689         }
 690       break;
 691       }
 692
 693     /* Otherwise, it's an LMTP error code return for one address */
 694
 695     else
 696       {
 697       if (buffer[0] == '4')
 698         {
 699         addr->basic_errno = ERRNO_DATA4XX;
 700         addr->more_errno |= ((buffer[1] - '0')*10 + buffer[2] - '0') << 8;
 701         }
 702       addr->message = string_sprintf("LMTP error after %s: %s", big_buffer,
 703         string_printing(buffer));
 704       addr->transport_return = (buffer[0] == '5')? FAIL : DEFER;
 705       setflag(addr, af_pass_message);   /* Allow message to go to user */
 706       }
 707     }
 708   }
 709
 710 /* The message transaction has completed successfully - this doesn't mean that
 711 all the addresses have necessarily been transferred, but each has its status
 712 set, so we change the yield to TRUE. */
 713
 714 yield = TRUE;
 715 (void) lmtp_write_command(fd_in, "QUIT\r\n");
 716 (void) lmtp_read_response(out, buffer, sizeof(buffer), '2', 1);
 717
 718 goto RETURN;
 719
 720
 721 /* Come here if any call to read_response, other than a response after the data
 722 phase, failed. Put the error in the top address - this will be replicated
 723 because the yield is still FALSE. (But omit ETIMEDOUT, as there will already be
 724 a suitable message.) Analyse the error, and if if isn't too bad, send a QUIT
 725 command. Wait for the response with a short timeout, so we don't wind up this
 726 process before the far end has had time to read the QUIT. */
 727
 728 RESPONSE_FAILED:
 729
 730 save_errno = errno;
 731 if (errno != ETIMEDOUT && errno != 0) addrlist->basic_errno = errno;
 732 addrlist->message = NULL;
 733
 734 if (check_response(&save_errno, addrlist->more_errno,
 735     buffer, &code, &(addrlist->message)))
 736   {
 737   (void) lmtp_write_command(fd_in, "QUIT\r\n");
 738   (void) lmtp_read_response(out, buffer, sizeof(buffer), '2', 1);
 739   }
 740
 741 addrlist->transport_return = (code == '5')? FAIL : DEFER;
 742 if (code == '4' && save_errno > 0)
 743   addrlist->message = string_sprintf("%s: %s", addrlist->message,
 744     strerror(save_errno));
 745 goto KILL_AND_RETURN;
 746
 747 /* Come here if there are errors during writing of a command or the message
 748 itself. This error will be applied to all the addresses. */
 749
 750 WRITE_FAILED:
 751
 752 addrlist->transport_return = PANIC;
 753 addrlist->basic_errno = errno;
 754 if (errno == ERRNO_CHHEADER_FAIL)
 755   addrlist->message =
 756     string_sprintf("Failed to expand headers_add or headers_remove: %s",
 757       expand_string_message);
 758 else if (errno == ERRNO_FILTER_FAIL)
 759   addrlist->message = string_sprintf("Filter process failure");
 760 else if (errno == ERRNO_WRITEINCOMPLETE)
 761   addrlist->message = string_sprintf("Failed repeatedly to write data");
 762 else if (errno == ERRNO_SMTPFORMAT)
 763   addrlist->message = US"overlong LMTP command generated";
 764 else
 765   addrlist->message = string_sprintf("Error %d", errno);
 766
 767 /* Come here after errors. Kill off the process. */
 768
 769 KILL_AND_RETURN:
 770
 771 if (pid > 0) killpg(pid, SIGKILL);
 772
 773 /* Come here from all paths after the subprocess is created. Wait for the
 774 process, but with a timeout. */
 775
 776 RETURN:
 777
 778 (void)child_close(pid, timeout);
 779
 780 if (fd_in >= 0) (void)close(fd_in);
 781 if (fd_out >= 0) (void)fclose(out);
 782
 783 DEBUG(D_transport)
 784   debug_printf("%s transport yields %d\n", tblock->name, yield);
 785
 786 return yield;
 787 }
 788
 789 /* End of transport/lmtp.c */