citadel/modules/smtp/serv_smtp.c

   1 /*
   2  * $Id$
   3  *
   4  * This module is an SMTP and ESMTP implementation for the Citadel system.
   5  * It is compliant with all of the following:
   6  *
   7  * RFC  821 - Simple Mail Transfer Protocol
   8  * RFC  876 - Survey of SMTP Implementations
   9  * RFC 1047 - Duplicate messages and SMTP
  10  * RFC 1652 - 8 bit MIME
  11  * RFC 1869 - Extended Simple Mail Transfer Protocol
  12  * RFC 1870 - SMTP Service Extension for Message Size Declaration
  13  * RFC 2033 - Local Mail Transfer Protocol
  14  * RFC 2197 - SMTP Service Extension for Command Pipelining
  15  * RFC 2476 - Message Submission
  16  * RFC 2487 - SMTP Service Extension for Secure SMTP over TLS
  17  * RFC 2554 - SMTP Service Extension for Authentication
  18  * RFC 2821 - Simple Mail Transfer Protocol
  19  * RFC 2822 - Internet Message Format
  20  * RFC 2920 - SMTP Service Extension for Command Pipelining
  21  *
  22  * The VRFY and EXPN commands have been removed from this implementation
  23  * because nobody uses these commands anymore, except for spammers.
  24  *
  25  */
  26
  27 #include "sysdep.h"
  28 #include <stdlib.h>
  29 #include <unistd.h>
  30 #include <stdio.h>
  31 #include <fcntl.h>
  32 #include <signal.h>
  33 #include <pwd.h>
  34 #include <errno.h>
  35 #include <sys/types.h>
  36 #include <syslog.h>
  37
  38 #if TIME_WITH_SYS_TIME
  39 # include <sys/time.h>
  40 # include <time.h>
  41 #else
  42 # if HAVE_SYS_TIME_H
  43 #  include <sys/time.h>
  44 # else
  45 #  include <time.h>
  46 # endif
  47 #endif
  48
  49 #include <sys/wait.h>
  50 #include <ctype.h>
  51 #include <string.h>
  52 #include <limits.h>
  53 #include <sys/socket.h>
  54 #include <netinet/in.h>
  55 #include <arpa/inet.h>
  56 #include <libcitadel.h>
  57 #include "citadel.h"
  58 #include "server.h"
  59 #include "citserver.h"
  60 #include "support.h"
  61 #include "config.h"
  62 #include "control.h"
  63 #include "room_ops.h"
  64 #include "user_ops.h"
  65 #include "policy.h"
  66 #include "database.h"
  67 #include "msgbase.h"
  68 #include "internet_addressing.h"
  69 #include "genstamp.h"
  70 #include "domain.h"
  71 #include "clientsocket.h"
  72 #include "locate_host.h"
  73 #include "citadel_dirs.h"
  74
  75
  76
  77 #ifndef HAVE_SNPRINTF
  78 #include "snprintf.h"
  79 #endif
  80
  81
  82 #include "ctdl_module.h"
  83
  84
  85
  86 struct citsmtp {                /* Information about the current session */
  87         int command_state;
  88         char helo_node[SIZ];
  89         char from[SIZ];
  90         char recipients[SIZ];
  91         int number_of_recipients;
  92         int delivery_mode;
  93         int message_originated_locally;
  94         int is_lmtp;
  95         int is_unfiltered;
  96         int is_msa;
  97 };
  98
  99 enum {                          /* Command states for login authentication */
 100         smtp_command,
 101         smtp_user,
 102         smtp_password,
 103         smtp_plain
 104 };
 105
 106 #define SMTP            ((struct citsmtp *)CC->session_specific_data)
 107
 108
 109 int run_queue_now = 0;  /* Set to 1 to ignore SMTP send retry times */
 110
 111
 112
 113 /*****************************************************************************/
 114 /*                      SMTP SERVER (INBOUND) STUFF                          */
 115 /*****************************************************************************/
 116
 117
 118 /*
 119  * Here's where our SMTP session begins its happy day.
 120  */
 121 void smtp_greeting(int is_msa)
 122 {
 123         char message_to_spammer[1024];
 124
 125         strcpy(CC->cs_clientname, "SMTP session");
 126         CC->internal_pgm = 1;
 127         CC->cs_flags |= CS_STEALTH;
 128         CC->session_specific_data = malloc(sizeof(struct citsmtp));
 129         memset(SMTP, 0, sizeof(struct citsmtp));
 130         SMTP->is_msa = is_msa;
 131
 132         /* If this config option is set, reject connections from problem
 133          * addresses immediately instead of after they execute a RCPT
 134          */
 135         if ( (config.c_rbl_at_greeting) && (SMTP->is_msa == 0) ) {
 136                 if (rbl_check(message_to_spammer)) {
 137                         if (CtdlThreadCheckStop())
 138                                 cprintf("421 %s\r\n", message_to_spammer);
 139                         else
 140                                 cprintf("550 %s\r\n", message_to_spammer);
 141                         CC->kill_me = 1;
 142                         /* no need to free_recipients(valid), it's not allocated yet */
 143                         return;
 144                 }
 145         }
 146
 147         /* Otherwise we're either clean or we check later. */
 148
 149         if (CC->nologin==1) {
 150                 cprintf("500 Too many users are already online (maximum is %d)\r\n",
 151                         config.c_maxsessions
 152                 );
 153                 CC->kill_me = 1;
 154                 /* no need to free_recipients(valid), it's not allocated yet */
 155                 return;
 156         }
 157
 158         /* Note: the FQDN *must* appear as the first thing after the 220 code.
 159          * Some clients (including citmail.c) depend on it being there.
 160          */
 161         cprintf("220 %s ESMTP Citadel server ready.\r\n", config.c_fqdn);
 162 }
 163
 164
 165 /*
 166  * SMTPS is just like SMTP, except it goes crypto right away.
 167  */
 168 void smtps_greeting(void) {
 169         CtdlModuleStartCryptoMsgs(NULL, NULL, NULL);
 170 #ifdef HAVE_OPENSSL
 171         if (!CC->redirect_ssl) CC->kill_me = 1;         /* kill session if no crypto */
 172 #endif
 173         smtp_greeting(0);
 174 }
 175
 176
 177 /*
 178  * SMTP MSA port requires authentication.
 179  */
 180 void smtp_msa_greeting(void) {
 181         smtp_greeting(1);
 182 }
 183
 184
 185 /*
 186  * LMTP is like SMTP but with some extra bonus footage added.
 187  */
 188 void lmtp_greeting(void) {
 189         smtp_greeting(0);
 190         SMTP->is_lmtp = 1;
 191 }
 192
 193
 194 /*
 195  * Generic SMTP MTA greeting
 196  */
 197 void smtp_mta_greeting(void) {
 198         smtp_greeting(0);
 199 }
 200
 201
 202 /*
 203  * We also have an unfiltered LMTP socket that bypasses spam filters.
 204  */
 205 void lmtp_unfiltered_greeting(void) {
 206         smtp_greeting(0);
 207         SMTP->is_lmtp = 1;
 208         SMTP->is_unfiltered = 1;
 209 }
 210
 211
 212 /*
 213  * Login greeting common to all auth methods
 214  */
 215 void smtp_auth_greeting(void) {
 216                 cprintf("235 Hello, %s\r\n", CC->user.fullname);
 217                 CtdlLogPrintf(CTDL_NOTICE, "SMTP authenticated %s\n", CC->user.fullname);
 218                 CC->internal_pgm = 0;
 219                 CC->cs_flags &= ~CS_STEALTH;
 220 }
 221
 222
 223 /*
 224  * Implement HELO and EHLO commands.
 225  *
 226  * which_command:  0=HELO, 1=EHLO, 2=LHLO
 227  */
 228 void smtp_hello(char *argbuf, int which_command) {
 229
 230         safestrncpy(SMTP->helo_node, argbuf, sizeof SMTP->helo_node);
 231
 232         if ( (which_command != 2) && (SMTP->is_lmtp) ) {
 233                 cprintf("500 Only LHLO is allowed when running LMTP\r\n");
 234                 return;
 235         }
 236
 237         if ( (which_command == 2) && (SMTP->is_lmtp == 0) ) {
 238                 cprintf("500 LHLO is only allowed when running LMTP\r\n");
 239                 return;
 240         }
 241
 242         if (which_command == 0) {
 243                 cprintf("250 Hello %s (%s [%s])\r\n",
 244                         SMTP->helo_node,
 245                         CC->cs_host,
 246                         CC->cs_addr
 247                 );
 248         }
 249         else {
 250                 if (which_command == 1) {
 251                         cprintf("250-Hello %s (%s [%s])\r\n",
 252                                 SMTP->helo_node,
 253                                 CC->cs_host,
 254                                 CC->cs_addr
 255                         );
 256                 }
 257                 else {
 258                         cprintf("250-Greetings and joyous salutations.\r\n");
 259                 }
 260                 cprintf("250-HELP\r\n");
 261                 cprintf("250-SIZE %ld\r\n", config.c_maxmsglen);
 262
 263 #ifdef HAVE_OPENSSL
 264                 /*
 265                  * Offer TLS, but only if TLS is not already active.
 266                  * Furthermore, only offer TLS when running on
 267                  * the SMTP-MSA port, not on the SMTP-MTA port, due to
 268                  * questionable reliability of TLS in certain sending MTA's.
 269                  */
 270                 if ( (!CC->redirect_ssl) && (SMTP->is_msa) ) {
 271                         cprintf("250-STARTTLS\r\n");
 272                 }
 273 #endif  /* HAVE_OPENSSL */
 274
 275                 cprintf("250-AUTH LOGIN PLAIN\r\n"
 276                         "250-AUTH=LOGIN PLAIN\r\n"
 277                         "250 8BITMIME\r\n"
 278                 );
 279         }
 280 }
 281
 282
 283
 284 /*
 285  * Implement HELP command.
 286  */
 287 void smtp_help(void) {
 288         cprintf("214 RTFM http://www.ietf.org/rfc/rfc2821.txt\r\n");
 289 }
 290
 291
 292 /*
 293  *
 294  */
 295 void smtp_get_user(char *argbuf) {
 296         char buf[SIZ];
 297         char username[SIZ];
 298
 299         CtdlDecodeBase64(username, argbuf, SIZ);
 300         /* CtdlLogPrintf(CTDL_DEBUG, "Trying <%s>\n", username); */
 301         if (CtdlLoginExistingUser(NULL, username) == login_ok) {
 302                 CtdlEncodeBase64(buf, "Password:", 9, 0);
 303                 cprintf("334 %s\r\n", buf);
 304                 SMTP->command_state = smtp_password;
 305         }
 306         else {
 307                 cprintf("500 No such user.\r\n");
 308                 SMTP->command_state = smtp_command;
 309         }
 310 }
 311
 312
 313 /*
 314  *
 315  */
 316 void smtp_get_pass(char *argbuf) {
 317         char password[SIZ];
 318
 319         CtdlDecodeBase64(password, argbuf, SIZ);
 320         /* CtdlLogPrintf(CTDL_DEBUG, "Trying <%s>\n", password); */
 321         if (CtdlTryPassword(password) == pass_ok) {
 322                 smtp_auth_greeting();
 323         }
 324         else {
 325                 cprintf("535 Authentication failed.\r\n");
 326         }
 327         SMTP->command_state = smtp_command;
 328 }
 329
 330
 331 /*
 332  * Back end for PLAIN auth method (either inline or multistate)
 333  */
 334 void smtp_try_plain(char *encoded_authstring) {
 335         char decoded_authstring[1024];
 336         char ident[256];
 337         char user[256];
 338         char pass[256];
 339         int result;
 340
 341         CtdlDecodeBase64(decoded_authstring, encoded_authstring, strlen(encoded_authstring) );
 342         safestrncpy(ident, decoded_authstring, sizeof ident);
 343         safestrncpy(user, &decoded_authstring[strlen(ident) + 1], sizeof user);
 344         safestrncpy(pass, &decoded_authstring[strlen(ident) + strlen(user) + 2], sizeof pass);
 345
 346         SMTP->command_state = smtp_command;
 347
 348         if (!IsEmptyStr(ident)) {
 349                 result = CtdlLoginExistingUser(user, ident);
 350         }
 351         else {
 352                 result = CtdlLoginExistingUser(NULL, user);
 353         }
 354
 355         if (result == login_ok) {
 356                 if (CtdlTryPassword(pass) == pass_ok) {
 357                         smtp_auth_greeting();
 358                         return;
 359                 }
 360         }
 361         cprintf("504 Authentication failed.\r\n");
 362 }
 363
 364
 365 /*
 366  * Attempt to perform authenticated SMTP
 367  */
 368 void smtp_auth(char *argbuf) {
 369         char username_prompt[64];
 370         char method[64];
 371         char encoded_authstring[1024];
 372
 373         if (CC->logged_in) {
 374                 cprintf("504 Already logged in.\r\n");
 375                 return;
 376         }
 377
 378         extract_token(method, argbuf, 0, ' ', sizeof method);
 379
 380         if (!strncasecmp(method, "login", 5) ) {
 381                 if (strlen(argbuf) >= 7) {
 382                         smtp_get_user(&argbuf[6]);
 383                 }
 384                 else {
 385                         CtdlEncodeBase64(username_prompt, "Username:", 9, 0);
 386                         cprintf("334 %s\r\n", username_prompt);
 387                         SMTP->command_state = smtp_user;
 388                 }
 389                 return;
 390         }
 391
 392         if (!strncasecmp(method, "plain", 5) ) {
 393                 if (num_tokens(argbuf, ' ') < 2) {
 394                         cprintf("334 \r\n");
 395                         SMTP->command_state = smtp_plain;
 396                         return;
 397                 }
 398
 399                 extract_token(encoded_authstring, argbuf, 1, ' ', sizeof encoded_authstring);
 400
 401                 smtp_try_plain(encoded_authstring);
 402                 return;
 403         }
 404
 405         if (strncasecmp(method, "login", 5) ) {
 406                 cprintf("504 Unknown authentication method.\r\n");
 407                 return;
 408         }
 409
 410 }
 411
 412
 413 /*
 414  * Implements the RSET (reset state) command.
 415  * Currently this just zeroes out the state buffer.  If pointers to data
 416  * allocated with malloc() are ever placed in the state buffer, we have to
 417  * be sure to free() them first!
 418  *
 419  * Set do_response to nonzero to output the SMTP RSET response code.
 420  */
 421 void smtp_rset(int do_response) {
 422         int is_lmtp;
 423         int is_unfiltered;
 424
 425         /*
 426          * Our entire SMTP state is discarded when a RSET command is issued,
 427          * but we need to preserve this one little piece of information, so
 428          * we save it for later.
 429          */
 430         is_lmtp = SMTP->is_lmtp;
 431         is_unfiltered = SMTP->is_unfiltered;
 432
 433         memset(SMTP, 0, sizeof(struct citsmtp));
 434
 435         /*
 436          * It is somewhat ambiguous whether we want to log out when a RSET
 437          * command is issued.  Here's the code to do it.  It is commented out
 438          * because some clients (such as Pine) issue RSET commands before
 439          * each message, but still expect to be logged in.
 440          *
 441          * if (CC->logged_in) {
 442          *      logout(CC);
 443          * }
 444          */
 445
 446         /*
 447          * Reinstate this little piece of information we saved (see above).
 448          */
 449         SMTP->is_lmtp = is_lmtp;
 450         SMTP->is_unfiltered = is_unfiltered;
 451
 452         if (do_response) {
 453                 cprintf("250 Zap!\r\n");
 454         }
 455 }
 456
 457 /*
 458  * Clear out the portions of the state buffer that need to be cleared out
 459  * after the DATA command finishes.
 460  */
 461 void smtp_data_clear(void) {
 462         strcpy(SMTP->from, "");
 463         strcpy(SMTP->recipients, "");
 464         SMTP->number_of_recipients = 0;
 465         SMTP->delivery_mode = 0;
 466         SMTP->message_originated_locally = 0;
 467 }
 468
 469 const char *smtp_get_Recipients(void)
 470 {
 471         if (SMTP == NULL)
 472                 return NULL;
 473         else return SMTP->from;
 474
 475 }
 476
 477 /*
 478  * Implements the "MAIL FROM:" command
 479  */
 480 void smtp_mail(char *argbuf) {
 481         char user[SIZ];
 482         char node[SIZ];
 483         char name[SIZ];
 484
 485         if (!IsEmptyStr(SMTP->from)) {
 486                 cprintf("503 Only one sender permitted\r\n");
 487                 return;
 488         }
 489
 490         if (strncasecmp(argbuf, "From:", 5)) {
 491                 cprintf("501 Syntax error\r\n");
 492                 return;
 493         }
 494
 495         strcpy(SMTP->from, &argbuf[5]);
 496         striplt(SMTP->from);
 497         if (haschar(SMTP->from, '<') > 0) {
 498                 stripallbut(SMTP->from, '<', '>');
 499         }
 500
 501         /* We used to reject empty sender names, until it was brought to our
 502          * attention that RFC1123 5.2.9 requires that this be allowed.  So now
 503          * we allow it, but replace the empty string with a fake
 504          * address so we don't have to contend with the empty string causing
 505          * other code to fail when it's expecting something there.
 506          */
 507         if (IsEmptyStr(SMTP->from)) {
 508                 strcpy(SMTP->from, "someone@example.com");
 509         }
 510
 511         /* If this SMTP connection is from a logged-in user, force the 'from'
 512          * to be the user's Internet e-mail address as Citadel knows it.
 513          */
 514         if (CC->logged_in) {
 515                 safestrncpy(SMTP->from, CC->cs_inet_email, sizeof SMTP->from);
 516                 cprintf("250 Sender ok <%s>\r\n", SMTP->from);
 517                 SMTP->message_originated_locally = 1;
 518                 return;
 519         }
 520
 521         else if (SMTP->is_lmtp) {
 522                 /* Bypass forgery checking for LMTP */
 523         }
 524
 525         /* Otherwise, make sure outsiders aren't trying to forge mail from
 526          * this system (unless, of course, c_allow_spoofing is enabled)
 527          */
 528         else if (config.c_allow_spoofing == 0) {
 529                 process_rfc822_addr(SMTP->from, user, node, name);
 530                 if (CtdlHostAlias(node) != hostalias_nomatch) {
 531                         cprintf("550 You must log in to send mail from %s\r\n", node);
 532                         strcpy(SMTP->from, "");
 533                         return;
 534                 }
 535         }
 536
 537         cprintf("250 Sender ok\r\n");
 538 }
 539
 540
 541
 542 /*
 543  * Implements the "RCPT To:" command
 544  */
 545 void smtp_rcpt(char *argbuf) {
 546         char recp[1024];
 547         char message_to_spammer[SIZ];
 548         struct recptypes *valid = NULL;
 549
 550         if (IsEmptyStr(SMTP->from)) {
 551                 cprintf("503 Need MAIL before RCPT\r\n");
 552                 return;
 553         }
 554
 555         if (strncasecmp(argbuf, "To:", 3)) {
 556                 cprintf("501 Syntax error\r\n");
 557                 return;
 558         }
 559
 560         if ( (SMTP->is_msa) && (!CC->logged_in) ) {
 561                 cprintf("550 You must log in to send mail on this port.\r\n");
 562                 strcpy(SMTP->from, "");
 563                 return;
 564         }
 565
 566         safestrncpy(recp, &argbuf[3], sizeof recp);
 567         striplt(recp);
 568         stripallbut(recp, '<', '>');
 569
 570         if ( (strlen(recp) + strlen(SMTP->recipients) + 1 ) >= SIZ) {
 571                 cprintf("452 Too many recipients\r\n");
 572                 return;
 573         }
 574
 575         /* RBL check */
 576         if ( (!CC->logged_in)   /* Don't RBL authenticated users */
 577            && (!SMTP->is_lmtp) ) {      /* Don't RBL LMTP clients */
 578                 if (config.c_rbl_at_greeting == 0) {    /* Don't RBL again if we already did it */
 579                         if (rbl_check(message_to_spammer)) {
 580                                 if (CtdlThreadCheckStop())
 581                                         cprintf("421 %s\r\n", message_to_spammer);
 582                                 else
 583                                         cprintf("550 %s\r\n", message_to_spammer);
 584                                 /* no need to free_recipients(valid), it's not allocated yet */
 585                                 return;
 586                         }
 587                 }
 588         }
 589
 590         valid = validate_recipients(recp,
 591                                     smtp_get_Recipients (),
 592                                     (SMTP->is_lmtp)? POST_LMTP:
 593                                        (CC->logged_in)? POST_LOGGED_IN:
 594                                                         POST_EXTERNAL);
 595         if (valid->num_error != 0) {
 596                 cprintf("550 %s\r\n", valid->errormsg);
 597                 free_recipients(valid);
 598                 return;
 599         }
 600
 601         if (valid->num_internet > 0) {
 602                 if (CC->logged_in) {
 603                         if (CtdlCheckInternetMailPermission(&CC->user)==0) {
 604                                 cprintf("551 <%s> - you do not have permission to send Internet mail\r\n", recp);
 605                                 free_recipients(valid);
 606                                 return;
 607                         }
 608                 }
 609         }
 610
 611         if (valid->num_internet > 0) {
 612                 if ( (SMTP->message_originated_locally == 0)
 613                    && (SMTP->is_lmtp == 0) ) {
 614                         cprintf("551 <%s> - relaying denied\r\n", recp);
 615                         free_recipients(valid);
 616                         return;
 617                 }
 618         }
 619
 620         cprintf("250 RCPT ok <%s>\r\n", recp);
 621         if (!IsEmptyStr(SMTP->recipients)) {
 622                 strcat(SMTP->recipients, ",");
 623         }
 624         strcat(SMTP->recipients, recp);
 625         SMTP->number_of_recipients += 1;
 626         if (valid != NULL)  {
 627                 free_recipients(valid);
 628         }
 629 }
 630
 631
 632
 633
 634 /*
 635  * Implements the DATA command
 636  */
 637 void smtp_data(void) {
 638         char *body;
 639         struct CtdlMessage *msg = NULL;
 640         long msgnum = (-1L);
 641         char nowstamp[SIZ];
 642         struct recptypes *valid;
 643         int scan_errors;
 644         int i;
 645         char result[SIZ];
 646
 647         if (IsEmptyStr(SMTP->from)) {
 648                 cprintf("503 Need MAIL command first.\r\n");
 649                 return;
 650         }
 651
 652         if (SMTP->number_of_recipients < 1) {
 653                 cprintf("503 Need RCPT command first.\r\n");
 654                 return;
 655         }
 656
 657         cprintf("354 Transmit message now - terminate with '.' by itself\r\n");
 658
 659         datestring(nowstamp, sizeof nowstamp, time(NULL), DATESTRING_RFC822);
 660         body = malloc(4096);
 661
 662         if (body != NULL) snprintf(body, 4096,
 663                 "Received: from %s (%s [%s])\n"
 664                 "       by %s; %s\n",
 665                         SMTP->helo_node,
 666                         CC->cs_host,
 667                         CC->cs_addr,
 668                         config.c_fqdn,
 669                         nowstamp);
 670
 671         body = CtdlReadMessageBody(".", config.c_maxmsglen, body, 1, 0);
 672         if (body == NULL) {
 673                 cprintf("550 Unable to save message: internal error.\r\n");
 674                 return;
 675         }
 676
 677         CtdlLogPrintf(CTDL_DEBUG, "Converting message...\n");
 678         msg = convert_internet_message(body);
 679
 680         /* If the user is locally authenticated, FORCE the From: header to
 681          * show up as the real sender.  Yes, this violates the RFC standard,
 682          * but IT MAKES SENSE.  If you prefer strict RFC adherence over
 683          * common sense, you can disable this in the configuration.
 684          *
 685          * We also set the "message room name" ('O' field) to MAILROOM
 686          * (which is Mail> on most systems) to prevent it from getting set
 687          * to something ugly like "0000058008.Sent Items>" when the message
 688          * is read with a Citadel client.
 689          */
 690         if ( (CC->logged_in) && (config.c_rfc822_strict_from == 0) ) {
 691                 if (msg->cm_fields['A'] != NULL) free(msg->cm_fields['A']);
 692                 if (msg->cm_fields['N'] != NULL) free(msg->cm_fields['N']);
 693                 if (msg->cm_fields['H'] != NULL) free(msg->cm_fields['H']);
 694                 if (msg->cm_fields['F'] != NULL) free(msg->cm_fields['F']);
 695                 if (msg->cm_fields['O'] != NULL) free(msg->cm_fields['O']);
 696                 msg->cm_fields['A'] = strdup(CC->user.fullname);
 697                 msg->cm_fields['N'] = strdup(config.c_nodename);
 698                 msg->cm_fields['H'] = strdup(config.c_humannode);
 699                 msg->cm_fields['F'] = strdup(CC->cs_inet_email);
 700                 msg->cm_fields['O'] = strdup(MAILROOM);
 701         }
 702
 703         /* Set the "envelope from" address */
 704         if (msg->cm_fields['P'] != NULL) {
 705                 free(msg->cm_fields['P']);
 706         }
 707         msg->cm_fields['P'] = strdup(SMTP->from);
 708
 709         /* Set the "envelope to" address */
 710         if (msg->cm_fields['V'] != NULL) {
 711                 free(msg->cm_fields['V']);
 712         }
 713         msg->cm_fields['V'] = strdup(SMTP->recipients);
 714
 715         /* Submit the message into the Citadel system. */
 716         valid = validate_recipients(SMTP->recipients,
 717                                     smtp_get_Recipients (),
 718                                     (SMTP->is_lmtp)? POST_LMTP:
 719                                        (CC->logged_in)? POST_LOGGED_IN:
 720                                                         POST_EXTERNAL);
 721
 722         /* If there are modules that want to scan this message before final
 723          * submission (such as virus checkers or spam filters), call them now
 724          * and give them an opportunity to reject the message.
 725          */
 726         if (SMTP->is_unfiltered) {
 727                 scan_errors = 0;
 728         }
 729         else {
 730                 scan_errors = PerformMessageHooks(msg, EVT_SMTPSCAN);
 731         }
 732
 733         if (scan_errors > 0) {  /* We don't want this message! */
 734
 735                 if (msg->cm_fields['0'] == NULL) {
 736                         msg->cm_fields['0'] = strdup("Message rejected by filter");
 737                 }
 738
 739                 sprintf(result, "550 %s\r\n", msg->cm_fields['0']);
 740         }
 741
 742         else {                  /* Ok, we'll accept this message. */
 743                 msgnum = CtdlSubmitMsg(msg, valid, "", 0);
 744                 if (msgnum > 0L) {
 745                         sprintf(result, "250 Message accepted.\r\n");
 746                 }
 747                 else {
 748                         sprintf(result, "550 Internal delivery error\r\n");
 749                 }
 750         }
 751
 752         /* For SMTP and ESTMP, just print the result message.  For LMTP, we
 753          * have to print one result message for each recipient.  Since there
 754          * is nothing in Citadel which would cause different recipients to
 755          * have different results, we can get away with just spitting out the
 756          * same message once for each recipient.
 757          */
 758         if (SMTP->is_lmtp) {
 759                 for (i=0; i<SMTP->number_of_recipients; ++i) {
 760                         cprintf("%s", result);
 761                 }
 762         }
 763         else {
 764                 cprintf("%s", result);
 765         }
 766
 767         /* Write something to the syslog (which may or may not be where the
 768          * rest of the Citadel logs are going; some sysadmins want LOG_MAIL).
 769          */
 770         if (enable_syslog) {
 771                 syslog((LOG_MAIL | LOG_INFO),
 772                         "%ld: from=<%s>, nrcpts=%d, relay=%s [%s], stat=%s",
 773                         msgnum,
 774                         SMTP->from,
 775                         SMTP->number_of_recipients,
 776                         CC->cs_host,
 777                         CC->cs_addr,
 778                         result
 779                 );
 780         }
 781
 782         /* Clean up */
 783         CtdlFreeMessage(msg);
 784         free_recipients(valid);
 785         smtp_data_clear();      /* clear out the buffers now */
 786 }
 787
 788
 789 /*
 790  * implements the STARTTLS command (Citadel API version)
 791  */
 792 void smtp_starttls(void)
 793 {
 794         char ok_response[SIZ];
 795         char nosup_response[SIZ];
 796         char error_response[SIZ];
 797
 798         sprintf(ok_response,
 799                 "220 Begin TLS negotiation now\r\n");
 800         sprintf(nosup_response,
 801                 "554 TLS not supported here\r\n");
 802         sprintf(error_response,
 803                 "554 Internal error\r\n");
 804         CtdlModuleStartCryptoMsgs(ok_response, nosup_response, error_response);
 805         smtp_rset(0);
 806 }
 807
 808
 809
 810 /*
 811  * Main command loop for SMTP sessions.
 812  */
 813 void smtp_command_loop(void) {
 814         char cmdbuf[SIZ];
 815
 816         time(&CC->lastcmd);
 817         memset(cmdbuf, 0, sizeof cmdbuf); /* Clear it, just in case */
 818         if (client_getln(cmdbuf, sizeof cmdbuf) < 1) {
 819                 CtdlLogPrintf(CTDL_CRIT, "Client disconnected: ending session.\n");
 820                 CC->kill_me = 1;
 821                 return;
 822         }
 823         CtdlLogPrintf(CTDL_INFO, "SMTP server: %s\n", cmdbuf);
 824         while (strlen(cmdbuf) < 5) strcat(cmdbuf, " ");
 825
 826         if (SMTP->command_state == smtp_user) {
 827                 smtp_get_user(cmdbuf);
 828         }
 829
 830         else if (SMTP->command_state == smtp_password) {
 831                 smtp_get_pass(cmdbuf);
 832         }
 833
 834         else if (SMTP->command_state == smtp_plain) {
 835                 smtp_try_plain(cmdbuf);
 836         }
 837
 838         else if (!strncasecmp(cmdbuf, "AUTH", 4)) {
 839                 smtp_auth(&cmdbuf[5]);
 840         }
 841
 842         else if (!strncasecmp(cmdbuf, "DATA", 4)) {
 843                 smtp_data();
 844         }
 845
 846         else if (!strncasecmp(cmdbuf, "HELO", 4)) {
 847                 smtp_hello(&cmdbuf[5], 0);
 848         }
 849
 850         else if (!strncasecmp(cmdbuf, "EHLO", 4)) {
 851                 smtp_hello(&cmdbuf[5], 1);
 852         }
 853
 854         else if (!strncasecmp(cmdbuf, "LHLO", 4)) {
 855                 smtp_hello(&cmdbuf[5], 2);
 856         }
 857
 858         else if (!strncasecmp(cmdbuf, "HELP", 4)) {
 859                 smtp_help();
 860         }
 861
 862         else if (!strncasecmp(cmdbuf, "MAIL", 4)) {
 863                 smtp_mail(&cmdbuf[5]);
 864         }
 865
 866         else if (!strncasecmp(cmdbuf, "NOOP", 4)) {
 867                 cprintf("250 NOOP\r\n");
 868         }
 869
 870         else if (!strncasecmp(cmdbuf, "QUIT", 4)) {
 871                 cprintf("221 Goodbye...\r\n");
 872                 CC->kill_me = 1;
 873                 return;
 874         }
 875
 876         else if (!strncasecmp(cmdbuf, "RCPT", 4)) {
 877                 smtp_rcpt(&cmdbuf[5]);
 878         }
 879
 880         else if (!strncasecmp(cmdbuf, "RSET", 4)) {
 881                 smtp_rset(1);
 882         }
 883 #ifdef HAVE_OPENSSL
 884         else if (!strcasecmp(cmdbuf, "STARTTLS")) {
 885                 smtp_starttls();
 886         }
 887 #endif
 888         else {
 889                 cprintf("502 I'm afraid I can't do that.\r\n");
 890         }
 891
 892
 893 }
 894
 895
 896
 897
 898 /*****************************************************************************/
 899 /*               SMTP CLIENT (OUTBOUND PROCESSING) STUFF                     */
 900 /*****************************************************************************/
 901
 902
 903
 904 /*
 905  * smtp_try()
 906  *
 907  * Called by smtp_do_procmsg() to attempt delivery to one SMTP host
 908  *
 909  */
 910 void smtp_try(const char *key, const char *addr, int *status,
 911               char *dsn, size_t n, long msgnum)
 912 {
 913         int sock = (-1);
 914         char mxhosts[1024];
 915         int num_mxhosts;
 916         int mx;
 917         int i;
 918         char user[1024], node[1024], name[1024];
 919         char buf[1024];
 920         char mailfrom[1024];
 921         char mx_user[256];
 922         char mx_pass[256];
 923         char mx_host[256];
 924         char mx_port[256];
 925         int lp, rp;
 926         char *msgtext;
 927         char *ptr;
 928         size_t msg_size;
 929         int scan_done;
 930
 931
 932         /* Parse out the host portion of the recipient address */
 933         process_rfc822_addr(addr, user, node, name);
 934
 935         CtdlLogPrintf(CTDL_DEBUG, "SMTP client: Attempting delivery to <%s> @ <%s> (%s)\n",
 936                 user, node, name);
 937
 938         /* Load the message out of the database */
 939         CC->redirect_buffer = malloc(SIZ);
 940         CC->redirect_len = 0;
 941         CC->redirect_alloc = SIZ;
 942         CtdlOutputMsg(msgnum, MT_RFC822, HEADERS_ALL, 0, 1, NULL, ESC_DOT);
 943         msgtext = CC->redirect_buffer;
 944         msg_size = CC->redirect_len;
 945         CC->redirect_buffer = NULL;
 946         CC->redirect_len = 0;
 947         CC->redirect_alloc = 0;
 948
 949         /* Extract something to send later in the 'MAIL FROM:' command */
 950         strcpy(mailfrom, "");
 951         scan_done = 0;
 952         ptr = msgtext;
 953         do {
 954                 if (ptr = memreadline(ptr, buf, sizeof buf), *ptr == 0) {
 955                         scan_done = 1;
 956                 }
 957                 if (!strncasecmp(buf, "From:", 5)) {
 958                         safestrncpy(mailfrom, &buf[5], sizeof mailfrom);
 959                         striplt(mailfrom);
 960                         for (i=0; mailfrom[i]; ++i) {
 961                                 if (!isprint(mailfrom[i])) {
 962                                         strcpy(&mailfrom[i], &mailfrom[i+1]);
 963                                         i=0;
 964                                 }
 965                         }
 966
 967                         /* Strip out parenthesized names */
 968                         lp = (-1);
 969                         rp = (-1);
 970                         for (i=0; mailfrom[i]; ++i) {
 971                                 if (mailfrom[i] == '(') lp = i;
 972                                 if (mailfrom[i] == ')') rp = i;
 973                         }
 974                         if ((lp>0)&&(rp>lp)) {
 975                                 strcpy(&mailfrom[lp-1], &mailfrom[rp+1]);
 976                         }
 977
 978                         /* Prefer brokketized names */
 979                         lp = (-1);
 980                         rp = (-1);
 981                         for (i=0; mailfrom[i]; ++i) {
 982                                 if (mailfrom[i] == '<') lp = i;
 983                                 if (mailfrom[i] == '>') rp = i;
 984                         }
 985                         if ( (lp>=0) && (rp>lp) ) {
 986                                 mailfrom[rp] = 0;
 987                                 strcpy(mailfrom, &mailfrom[lp]);
 988                         }
 989
 990                         scan_done = 1;
 991                 }
 992         } while (scan_done == 0);
 993         if (IsEmptyStr(mailfrom)) strcpy(mailfrom, "someone@somewhere.org");
 994         stripallbut(mailfrom, '<', '>');
 995
 996         /* Figure out what mail exchanger host we have to connect to */
 997         num_mxhosts = getmx(mxhosts, node);
 998         CtdlLogPrintf(CTDL_DEBUG, "Number of MX hosts for <%s> is %d [%s]\n", node, num_mxhosts, mxhosts);
 999         if (num_mxhosts < 1) {
1000                 *status = 5;
1001                 snprintf(dsn, SIZ, "No MX hosts found for <%s>", node);
1002                 return;
1003         }
1004
1005         sock = (-1);
1006         for (mx=0; (mx<num_mxhosts && sock < 0); ++mx) {
1007                 char *endpart;
1008                 extract_token(buf, mxhosts, mx, '|', sizeof buf);
1009                 strcpy(mx_user, "");
1010                 strcpy(mx_pass, "");
1011                 if (num_tokens(buf, '@') > 1) {
1012                         strcpy (mx_user, buf);
1013                         endpart = strrchr(mx_user, '@');
1014                         *endpart = '\0';
1015                         strcpy (mx_host, endpart + 1);
1016                         endpart = strrchr(mx_user, ':');
1017                         if (endpart != NULL) {
1018                                 strcpy(mx_pass, endpart+1);
1019                                 *endpart = '\0';
1020                         }
1021                 }
1022                 else
1023                         strcpy (mx_host, buf);
1024                 endpart = strrchr(mx_host, ':');
1025                 if (endpart != 0){
1026                         *endpart = '\0';
1027                         strcpy(mx_port, endpart + 1);
1028                 }
1029                 else {
1030                         strcpy(mx_port, "25");
1031                 }
1032                 CtdlLogPrintf(CTDL_DEBUG, "SMTP client: connecting to %s : %s ...\n", mx_host, mx_port);
1033                 sock = sock_connect(mx_host, mx_port, "tcp");
1034                 snprintf(dsn, SIZ, "Could not connect: %s", strerror(errno));
1035                 if (sock >= 0) CtdlLogPrintf(CTDL_DEBUG, "SMTP client: connected!\n");
1036                 if (sock < 0) {
1037                         if (errno > 0) {
1038                                 snprintf(dsn, SIZ, "%s", strerror(errno));
1039                         }
1040                         else {
1041                                 snprintf(dsn, SIZ, "Unable to connect to %s : %s\n", mx_host, mx_port);
1042                         }
1043                 }
1044         }
1045
1046         if (sock < 0) {
1047                 *status = 4;    /* dsn is already filled in */
1048                 return;
1049         }
1050
1051         /* Process the SMTP greeting from the server */
1052         if (ml_sock_gets(sock, buf) < 0) {
1053                 *status = 4;
1054                 strcpy(dsn, "Connection broken during SMTP conversation");
1055                 goto bail;
1056         }
1057         CtdlLogPrintf(CTDL_DEBUG, "<%s\n", buf);
1058         if (buf[0] != '2') {
1059                 if (buf[0] == '4') {
1060                         *status = 4;
1061                         safestrncpy(dsn, &buf[4], 1023);
1062                         goto bail;
1063                 }
1064                 else {
1065                         *status = 5;
1066                         safestrncpy(dsn, &buf[4], 1023);
1067                         goto bail;
1068                 }
1069         }
1070
1071         /* At this point we know we are talking to a real SMTP server */
1072
1073         /* Do a EHLO command.  If it fails, try the HELO command. */
1074         snprintf(buf, sizeof buf, "EHLO %s\r\n", config.c_fqdn);
1075         CtdlLogPrintf(CTDL_DEBUG, ">%s", buf);
1076         sock_write(sock, buf, strlen(buf));
1077         if (ml_sock_gets(sock, buf) < 0) {
1078                 *status = 4;
1079                 strcpy(dsn, "Connection broken during SMTP HELO");
1080                 goto bail;
1081         }
1082         CtdlLogPrintf(CTDL_DEBUG, "<%s\n", buf);
1083         if (buf[0] != '2') {
1084                 snprintf(buf, sizeof buf, "HELO %s\r\n", config.c_fqdn);
1085                 CtdlLogPrintf(CTDL_DEBUG, ">%s", buf);
1086                 sock_write(sock, buf, strlen(buf));
1087                 if (ml_sock_gets(sock, buf) < 0) {
1088                         *status = 4;
1089                         strcpy(dsn, "Connection broken during SMTP HELO");
1090                         goto bail;
1091                 }
1092         }
1093         if (buf[0] != '2') {
1094                 if (buf[0] == '4') {
1095                         *status = 4;
1096                         safestrncpy(dsn, &buf[4], 1023);
1097                         goto bail;
1098                 }
1099                 else {
1100                         *status = 5;
1101                         safestrncpy(dsn, &buf[4], 1023);
1102                         goto bail;
1103                 }
1104         }
1105
1106         /* Do an AUTH command if necessary */
1107         if (!IsEmptyStr(mx_user)) {
1108                 char encoded[1024];
1109                 sprintf(buf, "%s%c%s%c%s", mx_user, '\0', mx_user, '\0', mx_pass);
1110                 CtdlEncodeBase64(encoded, buf, strlen(mx_user) + strlen(mx_user) + strlen(mx_pass) + 2, 0);
1111                 snprintf(buf, sizeof buf, "AUTH PLAIN %s\r\n", encoded);
1112                 CtdlLogPrintf(CTDL_DEBUG, ">%s", buf);
1113                 sock_write(sock, buf, strlen(buf));
1114                 if (ml_sock_gets(sock, buf) < 0) {
1115                         *status = 4;
1116                         strcpy(dsn, "Connection broken during SMTP AUTH");
1117                         goto bail;
1118                 }
1119                 CtdlLogPrintf(CTDL_DEBUG, "<%s\n", buf);
1120                 if (buf[0] != '2') {
1121                         if (buf[0] == '4') {
1122                                 *status = 4;
1123                                 safestrncpy(dsn, &buf[4], 1023);
1124                                 goto bail;
1125                         }
1126                         else {
1127                                 *status = 5;
1128                                 safestrncpy(dsn, &buf[4], 1023);
1129                                 goto bail;
1130                         }
1131                 }
1132         }
1133
1134         /* previous command succeeded, now try the MAIL FROM: command */
1135         snprintf(buf, sizeof buf, "MAIL FROM:<%s>\r\n", mailfrom);
1136         CtdlLogPrintf(CTDL_DEBUG, ">%s", buf);
1137         sock_write(sock, buf, strlen(buf));
1138         if (ml_sock_gets(sock, buf) < 0) {
1139                 *status = 4;
1140                 strcpy(dsn, "Connection broken during SMTP MAIL");
1141                 goto bail;
1142         }
1143         CtdlLogPrintf(CTDL_DEBUG, "<%s\n", buf);
1144         if (buf[0] != '2') {
1145                 if (buf[0] == '4') {
1146                         *status = 4;
1147                         safestrncpy(dsn, &buf[4], 1023);
1148                         goto bail;
1149                 }
1150                 else {
1151                         *status = 5;
1152                         safestrncpy(dsn, &buf[4], 1023);
1153                         goto bail;
1154                 }
1155         }
1156
1157         /* MAIL succeeded, now try the RCPT To: command */
1158         snprintf(buf, sizeof buf, "RCPT TO:<%s@%s>\r\n", user, node);
1159         CtdlLogPrintf(CTDL_DEBUG, ">%s", buf);
1160         sock_write(sock, buf, strlen(buf));
1161         if (ml_sock_gets(sock, buf) < 0) {
1162                 *status = 4;
1163                 strcpy(dsn, "Connection broken during SMTP RCPT");
1164                 goto bail;
1165         }
1166         CtdlLogPrintf(CTDL_DEBUG, "<%s\n", buf);
1167         if (buf[0] != '2') {
1168                 if (buf[0] == '4') {
1169                         *status = 4;
1170                         safestrncpy(dsn, &buf[4], 1023);
1171                         goto bail;
1172                 }
1173                 else {
1174                         *status = 5;
1175                         safestrncpy(dsn, &buf[4], 1023);
1176                         goto bail;
1177                 }
1178         }
1179
1180         /* RCPT succeeded, now try the DATA command */
1181         CtdlLogPrintf(CTDL_DEBUG, ">DATA\n");
1182         sock_write(sock, "DATA\r\n", 6);
1183         if (ml_sock_gets(sock, buf) < 0) {
1184                 *status = 4;
1185                 strcpy(dsn, "Connection broken during SMTP DATA");
1186                 goto bail;
1187         }
1188         CtdlLogPrintf(CTDL_DEBUG, "<%s\n", buf);
1189         if (buf[0] != '3') {
1190                 if (buf[0] == '4') {
1191                         *status = 3;
1192                         safestrncpy(dsn, &buf[4], 1023);
1193                         goto bail;
1194                 }
1195                 else {
1196                         *status = 5;
1197                         safestrncpy(dsn, &buf[4], 1023);
1198                         goto bail;
1199                 }
1200         }
1201
1202         /* If we reach this point, the server is expecting data.*/
1203         sock_write(sock, msgtext, msg_size);
1204         if (msgtext[msg_size-1] != 10) {
1205                 CtdlLogPrintf(CTDL_WARNING, "Possible problem: message did not "
1206                         "correctly terminate. (expecting 0x10, got 0x%02x)\n",
1207                                 buf[msg_size-1]);
1208         }
1209
1210         sock_write(sock, ".\r\n", 3);
1211         if (ml_sock_gets(sock, buf) < 0) {
1212                 *status = 4;
1213                 strcpy(dsn, "Connection broken during SMTP message transmit");
1214                 goto bail;
1215         }
1216         CtdlLogPrintf(CTDL_DEBUG, "%s\n", buf);
1217         if (buf[0] != '2') {
1218                 if (buf[0] == '4') {
1219                         *status = 4;
1220                         safestrncpy(dsn, &buf[4], 1023);
1221                         goto bail;
1222                 }
1223                 else {
1224                         *status = 5;
1225                         safestrncpy(dsn, &buf[4], 1023);
1226                         goto bail;
1227                 }
1228         }
1229
1230         /* We did it! */
1231         safestrncpy(dsn, &buf[4], 1023);
1232         *status = 2;
1233
1234         CtdlLogPrintf(CTDL_DEBUG, ">QUIT\n");
1235         sock_write(sock, "QUIT\r\n", 6);
1236         ml_sock_gets(sock, buf);
1237         CtdlLogPrintf(CTDL_DEBUG, "<%s\n", buf);
1238         CtdlLogPrintf(CTDL_INFO, "SMTP client: delivery to <%s> @ <%s> (%s) succeeded\n",
1239                 user, node, name);
1240
1241 bail:   free(msgtext);
1242         sock_close(sock);
1243
1244         /* Write something to the syslog (which may or may not be where the
1245          * rest of the Citadel logs are going; some sysadmins want LOG_MAIL).
1246          */
1247         if (enable_syslog) {
1248                 syslog((LOG_MAIL | LOG_INFO),
1249                         "%ld: to=<%s>, relay=%s, stat=%s",
1250                         msgnum,
1251                         addr,
1252                         mx_host,
1253                         dsn
1254                 );
1255         }
1256
1257         return;
1258 }
1259
1260
1261
1262 /*
1263  * smtp_do_bounce() is caled by smtp_do_procmsg() to scan a set of delivery
1264  * instructions for "5" codes (permanent fatal errors) and produce/deliver
1265  * a "bounce" message (delivery status notification).
1266  */
1267 void smtp_do_bounce(char *instr) {
1268         int i;
1269         int lines;
1270         int status;
1271         char buf[1024];
1272         char key[1024];
1273         char addr[1024];
1274         char dsn[1024];
1275         char bounceto[1024];
1276         char boundary[64];
1277         int num_bounces = 0;
1278         int bounce_this = 0;
1279         long bounce_msgid = (-1);
1280         time_t submitted = 0L;
1281         struct CtdlMessage *bmsg = NULL;
1282         int give_up = 0;
1283         struct recptypes *valid;
1284         int successful_bounce = 0;
1285         static int seq = 0;
1286         char *omsgtext;
1287         size_t omsgsize;
1288         long omsgid = (-1);
1289
1290         CtdlLogPrintf(CTDL_DEBUG, "smtp_do_bounce() called\n");
1291         strcpy(bounceto, "");
1292         sprintf(boundary, "=_Citadel_Multipart_%s_%04x%04x", config.c_fqdn, getpid(), ++seq);
1293         lines = num_tokens(instr, '\n');
1294
1295         /* See if it's time to give up on delivery of this message */
1296         for (i=0; i<lines; ++i) {
1297                 extract_token(buf, instr, i, '\n', sizeof buf);
1298                 extract_token(key, buf, 0, '|', sizeof key);
1299                 extract_token(addr, buf, 1, '|', sizeof addr);
1300                 if (!strcasecmp(key, "submitted")) {
1301                         submitted = atol(addr);
1302                 }
1303         }
1304
1305         if ( (time(NULL) - submitted) > SMTP_GIVE_UP ) {
1306                 give_up = 1;
1307         }
1308
1309         /* Start building our bounce message */
1310
1311         bmsg = (struct CtdlMessage *) malloc(sizeof(struct CtdlMessage));
1312         if (bmsg == NULL) return;
1313         memset(bmsg, 0, sizeof(struct CtdlMessage));
1314
1315         bmsg->cm_magic = CTDLMESSAGE_MAGIC;
1316         bmsg->cm_anon_type = MES_NORMAL;
1317         bmsg->cm_format_type = FMT_RFC822;
1318         bmsg->cm_fields['A'] = strdup("Citadel");
1319         bmsg->cm_fields['O'] = strdup(MAILROOM);
1320         bmsg->cm_fields['N'] = strdup(config.c_nodename);
1321         bmsg->cm_fields['U'] = strdup("Delivery Status Notification (Failure)");
1322         bmsg->cm_fields['M'] = malloc(1024);
1323
1324         strcpy(bmsg->cm_fields['M'], "Content-type: multipart/mixed; boundary=\"");
1325         strcat(bmsg->cm_fields['M'], boundary);
1326         strcat(bmsg->cm_fields['M'], "\"\r\n");
1327         strcat(bmsg->cm_fields['M'], "MIME-Version: 1.0\r\n");
1328         strcat(bmsg->cm_fields['M'], "X-Mailer: " CITADEL "\r\n");
1329         strcat(bmsg->cm_fields['M'], "\r\nThis is a multipart message in MIME format.\r\n\r\n");
1330         strcat(bmsg->cm_fields['M'], "--");
1331         strcat(bmsg->cm_fields['M'], boundary);
1332         strcat(bmsg->cm_fields['M'], "\r\n");
1333         strcat(bmsg->cm_fields['M'], "Content-type: text/plain\r\n\r\n");
1334
1335         if (give_up) strcat(bmsg->cm_fields['M'],
1336 "A message you sent could not be delivered to some or all of its recipients\n"
1337 "due to prolonged unavailability of its destination(s).\n"
1338 "Giving up on the following addresses:\n\n"
1339 );
1340
1341         else strcat(bmsg->cm_fields['M'],
1342 "A message you sent could not be delivered to some or all of its recipients.\n"
1343 "The following addresses were undeliverable:\n\n"
1344 );
1345
1346         /*
1347          * Now go through the instructions checking for stuff.
1348          */
1349         for (i=0; i<lines; ++i) {
1350                 extract_token(buf, instr, i, '\n', sizeof buf);
1351                 extract_token(key, buf, 0, '|', sizeof key);
1352                 extract_token(addr, buf, 1, '|', sizeof addr);
1353                 status = extract_int(buf, 2);
1354                 extract_token(dsn, buf, 3, '|', sizeof dsn);
1355                 bounce_this = 0;
1356
1357                 CtdlLogPrintf(CTDL_DEBUG, "key=<%s> addr=<%s> status=%d dsn=<%s>\n",
1358                         key, addr, status, dsn);
1359
1360                 if (!strcasecmp(key, "bounceto")) {
1361                         strcpy(bounceto, addr);
1362                 }
1363
1364                 if (!strcasecmp(key, "msgid")) {
1365                         omsgid = atol(addr);
1366                 }
1367
1368                 if (!strcasecmp(key, "remote")) {
1369                         if (status == 5) bounce_this = 1;
1370                         if (give_up) bounce_this = 1;
1371                 }
1372
1373                 if (bounce_this) {
1374                         ++num_bounces;
1375
1376                         if (bmsg->cm_fields['M'] == NULL) {
1377                                 CtdlLogPrintf(CTDL_ERR, "ERROR ... M field is null "
1378                                         "(%s:%d)\n", __FILE__, __LINE__);
1379                         }
1380
1381                         bmsg->cm_fields['M'] = realloc(bmsg->cm_fields['M'],
1382                                 strlen(bmsg->cm_fields['M']) + 1024 );
1383                         strcat(bmsg->cm_fields['M'], addr);
1384                         strcat(bmsg->cm_fields['M'], ": ");
1385                         strcat(bmsg->cm_fields['M'], dsn);
1386                         strcat(bmsg->cm_fields['M'], "\r\n");
1387
1388                         remove_token(instr, i, '\n');
1389                         --i;
1390                         --lines;
1391                 }
1392         }
1393
1394         /* Attach the original message */
1395         if (omsgid >= 0) {
1396                 strcat(bmsg->cm_fields['M'], "--");
1397                 strcat(bmsg->cm_fields['M'], boundary);
1398                 strcat(bmsg->cm_fields['M'], "\r\n");
1399                 strcat(bmsg->cm_fields['M'], "Content-type: message/rfc822\r\n");
1400                 strcat(bmsg->cm_fields['M'], "Content-Transfer-Encoding: 7bit\r\n");
1401                 strcat(bmsg->cm_fields['M'], "Content-Disposition: inline\r\n");
1402                 strcat(bmsg->cm_fields['M'], "\r\n");
1403
1404                 CC->redirect_buffer = malloc(SIZ);
1405                 CC->redirect_len = 0;
1406                 CC->redirect_alloc = SIZ;
1407                 CtdlOutputMsg(omsgid, MT_RFC822, HEADERS_ALL, 0, 1, NULL, 0);
1408                 omsgtext = CC->redirect_buffer;
1409                 omsgsize = CC->redirect_len;
1410                 CC->redirect_buffer = NULL;
1411                 CC->redirect_len = 0;
1412                 CC->redirect_alloc = 0;
1413                 bmsg->cm_fields['M'] = realloc(bmsg->cm_fields['M'],
1414                                 (strlen(bmsg->cm_fields['M']) + omsgsize + 1024) );
1415                 strcat(bmsg->cm_fields['M'], omsgtext);
1416                 free(omsgtext);
1417         }
1418
1419         /* Close the multipart MIME scope */
1420         strcat(bmsg->cm_fields['M'], "--");
1421         strcat(bmsg->cm_fields['M'], boundary);
1422         strcat(bmsg->cm_fields['M'], "--\r\n");
1423
1424         /* Deliver the bounce if there's anything worth mentioning */
1425         CtdlLogPrintf(CTDL_DEBUG, "num_bounces = %d\n", num_bounces);
1426         if (num_bounces > 0) {
1427
1428                 /* First try the user who sent the message */
1429                 CtdlLogPrintf(CTDL_DEBUG, "bounce to user? <%s>\n", bounceto);
1430                 if (IsEmptyStr(bounceto)) {
1431                         CtdlLogPrintf(CTDL_ERR, "No bounce address specified\n");
1432                         bounce_msgid = (-1L);
1433                 }
1434
1435                 /* Can we deliver the bounce to the original sender? */
1436                 valid = validate_recipients(bounceto, smtp_get_Recipients (), 0);
1437                 if (valid != NULL) {
1438                         if (valid->num_error == 0) {
1439                                 CtdlSubmitMsg(bmsg, valid, "", QP_EADDR);
1440                                 successful_bounce = 1;
1441                         }
1442                 }
1443
1444                 /* If not, post it in the Aide> room */
1445                 if (successful_bounce == 0) {
1446                         CtdlSubmitMsg(bmsg, NULL, config.c_aideroom, QP_EADDR);
1447                 }
1448
1449                 /* Free up the memory we used */
1450                 if (valid != NULL) {
1451                         free_recipients(valid);
1452                 }
1453         }
1454
1455         CtdlFreeMessage(bmsg);
1456         CtdlLogPrintf(CTDL_DEBUG, "Done processing bounces\n");
1457 }
1458
1459
1460 /*
1461  * smtp_purge_completed_deliveries() is caled by smtp_do_procmsg() to scan a
1462  * set of delivery instructions for completed deliveries and remove them.
1463  *
1464  * It returns the number of incomplete deliveries remaining.
1465  */
1466 int smtp_purge_completed_deliveries(char *instr) {
1467         int i;
1468         int lines;
1469         int status;
1470         char buf[1024];
1471         char key[1024];
1472         char addr[1024];
1473         char dsn[1024];
1474         int completed;
1475         int incomplete = 0;
1476
1477         lines = num_tokens(instr, '\n');
1478         for (i=0; i<lines; ++i) {
1479                 extract_token(buf, instr, i, '\n', sizeof buf);
1480                 extract_token(key, buf, 0, '|', sizeof key);
1481                 extract_token(addr, buf, 1, '|', sizeof addr);
1482                 status = extract_int(buf, 2);
1483                 extract_token(dsn, buf, 3, '|', sizeof dsn);
1484
1485                 completed = 0;
1486
1487                 if (!strcasecmp(key, "remote")) {
1488                         if (status == 2) completed = 1;
1489                         else ++incomplete;
1490                 }
1491
1492                 if (completed) {
1493                         remove_token(instr, i, '\n');
1494                         --i;
1495                         --lines;
1496                 }
1497         }
1498
1499         return(incomplete);
1500 }
1501
1502
1503 /*
1504  * smtp_do_procmsg()
1505  *
1506  * Called by smtp_do_queue() to handle an individual message.
1507  */
1508 void smtp_do_procmsg(long msgnum, void *userdata) {
1509         struct CtdlMessage *msg = NULL;
1510         char *instr = NULL;
1511         char *results = NULL;
1512         int i;
1513         int lines;
1514         int status;
1515         char buf[1024];
1516         char key[1024];
1517         char addr[1024];
1518         char dsn[1024];
1519         long text_msgid = (-1);
1520         int incomplete_deliveries_remaining;
1521         time_t attempted = 0L;
1522         time_t last_attempted = 0L;
1523         time_t retry = SMTP_RETRY_INTERVAL;
1524
1525         CtdlLogPrintf(CTDL_DEBUG, "SMTP client: smtp_do_procmsg(%ld)\n", msgnum);
1526
1527         msg = CtdlFetchMessage(msgnum, 1);
1528         if (msg == NULL) {
1529                 CtdlLogPrintf(CTDL_ERR, "SMTP client: tried %ld but no such message!\n", msgnum);
1530                 return;
1531         }
1532
1533         instr = strdup(msg->cm_fields['M']);
1534         CtdlFreeMessage(msg);
1535
1536         /* Strip out the headers amd any other non-instruction line */
1537         lines = num_tokens(instr, '\n');
1538         for (i=0; i<lines; ++i) {
1539                 extract_token(buf, instr, i, '\n', sizeof buf);
1540                 if (num_tokens(buf, '|') < 2) {
1541                         remove_token(instr, i, '\n');
1542                         --lines;
1543                         --i;
1544                 }
1545         }
1546
1547         /* Learn the message ID and find out about recent delivery attempts */
1548         lines = num_tokens(instr, '\n');
1549         for (i=0; i<lines; ++i) {
1550                 extract_token(buf, instr, i, '\n', sizeof buf);
1551                 extract_token(key, buf, 0, '|', sizeof key);
1552                 if (!strcasecmp(key, "msgid")) {
1553                         text_msgid = extract_long(buf, 1);
1554                 }
1555                 if (!strcasecmp(key, "retry")) {
1556                         /* double the retry interval after each attempt */
1557                         retry = extract_long(buf, 1) * 2L;
1558                         if (retry > SMTP_RETRY_MAX) {
1559                                 retry = SMTP_RETRY_MAX;
1560                         }
1561                         remove_token(instr, i, '\n');
1562                 }
1563                 if (!strcasecmp(key, "attempted")) {
1564                         attempted = extract_long(buf, 1);
1565                         if (attempted > last_attempted)
1566                                 last_attempted = attempted;
1567                 }
1568         }
1569
1570         /*
1571          * Postpone delivery if we've already tried recently.
1572          */
1573         if (((time(NULL) - last_attempted) < retry) && (run_queue_now == 0)) {
1574                 CtdlLogPrintf(CTDL_DEBUG, "SMTP client: Retry time not yet reached.\n");
1575                 free(instr);
1576                 return;
1577         }
1578
1579
1580         /*
1581          * Bail out if there's no actual message associated with this
1582          */
1583         if (text_msgid < 0L) {
1584                 CtdlLogPrintf(CTDL_ERR, "SMTP client: no 'msgid' directive found!\n");
1585                 free(instr);
1586                 return;
1587         }
1588
1589         /* Plow through the instructions looking for 'remote' directives and
1590          * a status of 0 (no delivery yet attempted) or 3/4 (transient errors
1591          * were experienced and it's time to try again)
1592          */
1593         lines = num_tokens(instr, '\n');
1594         for (i=0; i<lines; ++i) {
1595                 extract_token(buf, instr, i, '\n', sizeof buf);
1596                 extract_token(key, buf, 0, '|', sizeof key);
1597                 extract_token(addr, buf, 1, '|', sizeof addr);
1598                 status = extract_int(buf, 2);
1599                 extract_token(dsn, buf, 3, '|', sizeof dsn);
1600                 if ( (!strcasecmp(key, "remote"))
1601                    && ((status==0)||(status==3)||(status==4)) ) {
1602
1603                         /* Remove this "remote" instruction from the set,
1604                          * but replace the set's final newline if
1605                          * remove_token() stripped it.  It has to be there.
1606                          */
1607                         remove_token(instr, i, '\n');
1608                         if (instr[strlen(instr)-1] != '\n') {
1609                                 strcat(instr, "\n");
1610                         }
1611
1612                         --i;
1613                         --lines;
1614                         CtdlLogPrintf(CTDL_DEBUG, "SMTP client: Trying <%s>\n", addr);
1615                         smtp_try(key, addr, &status, dsn, sizeof dsn, text_msgid);
1616                         if (status != 2) {
1617                                 if (results == NULL) {
1618                                         results = malloc(1024);
1619                                         memset(results, 0, 1024);
1620                                 }
1621                                 else {
1622                                         results = realloc(results, strlen(results) + 1024);
1623                                 }
1624                                 snprintf(&results[strlen(results)], 1024,
1625                                         "%s|%s|%d|%s\n",
1626                                         key, addr, status, dsn);
1627                         }
1628                 }
1629         }
1630
1631         if (results != NULL) {
1632                 instr = realloc(instr, strlen(instr) + strlen(results) + 2);
1633                 strcat(instr, results);
1634                 free(results);
1635         }
1636
1637
1638         /* Generate 'bounce' messages */
1639         smtp_do_bounce(instr);
1640
1641         /* Go through the delivery list, deleting completed deliveries */
1642         incomplete_deliveries_remaining =
1643                 smtp_purge_completed_deliveries(instr);
1644
1645
1646         /*
1647          * No delivery instructions remain, so delete both the instructions
1648          * message and the message message.
1649          */
1650         if (incomplete_deliveries_remaining <= 0) {
1651                 long delmsgs[2];
1652                 delmsgs[0] = msgnum;
1653                 delmsgs[1] = text_msgid;
1654                 CtdlDeleteMessages(SMTP_SPOOLOUT_ROOM, delmsgs, 2, "");
1655         }
1656
1657         /*
1658          * Uncompleted delivery instructions remain, so delete the old
1659          * instructions and replace with the updated ones.
1660          */
1661         if (incomplete_deliveries_remaining > 0) {
1662                 CtdlDeleteMessages(SMTP_SPOOLOUT_ROOM, &msgnum, 1, "");
1663                 msg = malloc(sizeof(struct CtdlMessage));
1664                 memset(msg, 0, sizeof(struct CtdlMessage));
1665                 msg->cm_magic = CTDLMESSAGE_MAGIC;
1666                 msg->cm_anon_type = MES_NORMAL;
1667                 msg->cm_format_type = FMT_RFC822;
1668                 msg->cm_fields['M'] = malloc(strlen(instr)+SIZ);
1669                 snprintf(msg->cm_fields['M'],
1670                         strlen(instr)+SIZ,
1671                         "Content-type: %s\n\n%s\n"
1672                         "attempted|%ld\n"
1673                         "retry|%ld\n",
1674                         SPOOLMIME, instr, (long)time(NULL), (long)retry );
1675                 CtdlSubmitMsg(msg, NULL, SMTP_SPOOLOUT_ROOM, QP_EADDR);
1676                 CtdlFreeMessage(msg);
1677         }
1678
1679         free(instr);
1680 }
1681
1682
1683
1684 /*
1685  * smtp_do_queue()
1686  *
1687  * Run through the queue sending out messages.
1688  */
1689 void smtp_do_queue(void) {
1690         static int doing_queue = 0;
1691
1692         /*
1693          * This is a simple concurrency check to make sure only one queue run
1694          * is done at a time.  We could do this with a mutex, but since we
1695          * don't really require extremely fine granularity here, we'll do it
1696          * with a static variable instead.
1697          */
1698         if (doing_queue) return;
1699         doing_queue = 1;
1700
1701         /*
1702          * Go ahead and run the queue
1703          */
1704         CtdlLogPrintf(CTDL_INFO, "SMTP client: processing outbound queue\n");
1705
1706         if (getroom(&CC->room, SMTP_SPOOLOUT_ROOM) != 0) {
1707                 CtdlLogPrintf(CTDL_ERR, "Cannot find room <%s>\n", SMTP_SPOOLOUT_ROOM);
1708                 return;
1709         }
1710         CtdlForEachMessage(MSGS_ALL, 0L, NULL,
1711                 SPOOLMIME, NULL, smtp_do_procmsg, NULL);
1712
1713         CtdlLogPrintf(CTDL_INFO, "SMTP client: queue run completed\n");
1714         run_queue_now = 0;
1715         doing_queue = 0;
1716 }
1717
1718
1719
1720 /*****************************************************************************/
1721 /*                          SMTP UTILITY COMMANDS                            */
1722 /*****************************************************************************/
1723
1724 void cmd_smtp(char *argbuf) {
1725         char cmd[64];
1726         char node[256];
1727         char buf[1024];
1728         int i;
1729         int num_mxhosts;
1730
1731         if (CtdlAccessCheck(ac_aide)) return;
1732
1733         extract_token(cmd, argbuf, 0, '|', sizeof cmd);
1734
1735         if (!strcasecmp(cmd, "mx")) {
1736                 extract_token(node, argbuf, 1, '|', sizeof node);
1737                 num_mxhosts = getmx(buf, node);
1738                 cprintf("%d %d MX hosts listed for %s\n",
1739                         LISTING_FOLLOWS, num_mxhosts, node);
1740                 for (i=0; i<num_mxhosts; ++i) {
1741                         extract_token(node, buf, i, '|', sizeof node);
1742                         cprintf("%s\n", node);
1743                 }
1744                 cprintf("000\n");
1745                 return;
1746         }
1747
1748         else if (!strcasecmp(cmd, "runqueue")) {
1749                 run_queue_now = 1;
1750                 cprintf("%d All outbound SMTP will be retried now.\n", CIT_OK);
1751                 return;
1752         }
1753
1754         else {
1755                 cprintf("%d Invalid command.\n", ERROR + ILLEGAL_VALUE);
1756         }
1757
1758 }
1759
1760
1761 /*
1762  * Initialize the SMTP outbound queue
1763  */
1764 void smtp_init_spoolout(void) {
1765         struct ctdlroom qrbuf;
1766
1767         /*
1768          * Create the room.  This will silently fail if the room already
1769          * exists, and that's perfectly ok, because we want it to exist.
1770          */
1771         create_room(SMTP_SPOOLOUT_ROOM, 3, "", 0, 1, 0, VIEW_MAILBOX);
1772
1773         /*
1774          * Make sure it's set to be a "system room" so it doesn't show up
1775          * in the <K>nown rooms list for Aides.
1776          */
1777         if (lgetroom(&qrbuf, SMTP_SPOOLOUT_ROOM) == 0) {
1778                 qrbuf.QRflags2 |= QR2_SYSTEM;
1779                 lputroom(&qrbuf);
1780         }
1781 }
1782
1783
1784
1785
1786 /*****************************************************************************/
1787 /*                      MODULE INITIALIZATION STUFF                          */
1788 /*****************************************************************************/
1789 /*
1790  * This cleanup function blows away the temporary memory used by
1791  * the SMTP server.
1792  */
1793 void smtp_cleanup_function(void) {
1794
1795         /* Don't do this stuff if this is not an SMTP session! */
1796         if (CC->h_command_function != smtp_command_loop) return;
1797
1798         CtdlLogPrintf(CTDL_DEBUG, "Performing SMTP cleanup hook\n");
1799         free(SMTP);
1800 }
1801
1802
1803
1804 const char *CitadelServiceSMTP_MTA="SMTP-MTA";
1805 const char *CitadelServiceSMTPS_MTA="SMTPs-MTA";
1806 const char *CitadelServiceSMTP_MSA="SMTP-MSA";
1807 const char *CitadelServiceSMTP_LMTP="LMTP";
1808 const char *CitadelServiceSMTP_LMTP_UNF="LMTP-UnF";
1809
1810 CTDL_MODULE_INIT(smtp)
1811 {
1812         if (!threading)
1813         {
1814                 CtdlRegisterServiceHook(config.c_smtp_port,     /* SMTP MTA */
1815                                         NULL,
1816                                         smtp_mta_greeting,
1817                                         smtp_command_loop,
1818                                         NULL,
1819                                         CitadelServiceSMTP_MTA);
1820
1821 #ifdef HAVE_OPENSSL
1822                 CtdlRegisterServiceHook(config.c_smtps_port,
1823                                         NULL,
1824                                         smtps_greeting,
1825                                         smtp_command_loop,
1826                                         NULL,
1827                                         CitadelServiceSMTPS_MTA);
1828 #endif
1829
1830                 CtdlRegisterServiceHook(config.c_msa_port,      /* SMTP MSA */
1831                                         NULL,
1832                                         smtp_msa_greeting,
1833                                         smtp_command_loop,
1834                                         NULL,
1835                                         CitadelServiceSMTP_MSA);
1836
1837                 CtdlRegisterServiceHook(0,                      /* local LMTP */
1838                                         file_lmtp_socket,
1839                                         lmtp_greeting,
1840                                         smtp_command_loop,
1841                                         NULL,
1842                                         CitadelServiceSMTP_LMTP);
1843
1844                 CtdlRegisterServiceHook(0,                      /* local LMTP */
1845                                         file_lmtp_unfiltered_socket,
1846                                         lmtp_unfiltered_greeting,
1847                                         smtp_command_loop,
1848                                         NULL,
1849                                         CitadelServiceSMTP_LMTP_UNF);
1850
1851                 smtp_init_spoolout();
1852                 CtdlRegisterSessionHook(smtp_do_queue, EVT_TIMER);
1853                 CtdlRegisterSessionHook(smtp_cleanup_function, EVT_STOP);
1854                 CtdlRegisterProtoHook(cmd_smtp, "SMTP", "SMTP utility commands");
1855         }
1856
1857         /* return our Subversion id for the Log */
1858         return "$Id$";
1859 }