citadel/modules/smtp/smtp_clienthandlers.c

   1 /*
   2  * This module is an SMTP and ESMTP implementation for the Citadel system.
   3  * It is compliant with all of the following:
   4  *
   5  * RFC  821 - Simple Mail Transfer Protocol
   6  * RFC  876 - Survey of SMTP Implementations
   7  * RFC 1047 - Duplicate messages and SMTP
   8  * RFC 1652 - 8 bit MIME
   9  * RFC 1869 - Extended Simple Mail Transfer Protocol
  10  * RFC 1870 - SMTP Service Extension for Message Size Declaration
  11  * RFC 2033 - Local Mail Transfer Protocol
  12  * RFC 2197 - SMTP Service Extension for Command Pipelining
  13  * RFC 2476 - Message Submission
  14  * RFC 2487 - SMTP Service Extension for Secure SMTP over TLS
  15  * RFC 2554 - SMTP Service Extension for Authentication
  16  * RFC 2821 - Simple Mail Transfer Protocol
  17  * RFC 2822 - Internet Message Format
  18  * RFC 2920 - SMTP Service Extension for Command Pipelining
  19  *
  20  * Copyright (c) 1998-2012 by the citadel.org team
  21  *
  22  *  This program is open source software; you can redistribute it and/or modify
  23  *  it under the terms of the GNU General Public License version 3.
  24  *
  25  *
  26  *
  27  *  This program is distributed in the hope that it will be useful,
  28  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  29  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  30  *  GNU General Public License for more details.
  31  *
  32  *
  33  *
  34  *
  35  */
  36
  37 #include "sysdep.h"
  38 #include <stdlib.h>
  39 #include <unistd.h>
  40 #include <stdio.h>
  41 #include <termios.h>
  42 #include <fcntl.h>
  43 #include <signal.h>
  44 #include <pwd.h>
  45 #include <errno.h>
  46 #include <sys/types.h>
  47 #include <syslog.h>
  48
  49 #if TIME_WITH_SYS_TIME
  50 # include <sys/time.h>
  51 # include <time.h>
  52 #else
  53 # if HAVE_SYS_TIME_H
  54 #  include <sys/time.h>
  55 # else
  56 #  include <time.h>
  57 # endif
  58 #endif
  59 #include <sys/wait.h>
  60 #include <ctype.h>
  61 #include <string.h>
  62 #include <limits.h>
  63 #include <sys/socket.h>
  64 #include <netinet/in.h>
  65 #include <arpa/inet.h>
  66 #include <libcitadel.h>
  67 #include "citadel.h"
  68 #include "server.h"
  69 #include "citserver.h"
  70 #include "support.h"
  71 #include "config.h"
  72 #include "control.h"
  73 #include "user_ops.h"
  74 #include "database.h"
  75 #include "msgbase.h"
  76 #include "internet_addressing.h"
  77 #include "genstamp.h"
  78 #include "domain.h"
  79 #include "clientsocket.h"
  80 #include "locate_host.h"
  81 #include "citadel_dirs.h"
  82
  83 #include "ctdl_module.h"
  84
  85 #include "smtp_util.h"
  86 #include "event_client.h"
  87 #include "smtpqueue.h"
  88 #include "smtp_clienthandlers.h"
  89
  90
  91 #define SMTP_ERROR(WHICH_ERR, ERRSTR) do {                             \
  92                 Msg->MyQEntry->Status = WHICH_ERR;                     \
  93                 StrBufAppendBufPlain(Msg->MyQEntry->StatusMessage,     \
  94                                      HKEY(ERRSTR), 0);                 \
  95                 StrBufTrim(Msg->MyQEntry->StatusMessage);              \
  96                 return eAbort; }                                       \
  97         while (0)
  98
  99 #define SMTP_VERROR(WHICH_ERR) do {                            \
 100                 Msg->MyQEntry->Status = WHICH_ERR;             \
 101                 StrBufPlain(Msg->MyQEntry->StatusMessage,      \
 102                             ChrPtr(Msg->IO.IOBuf) + 4,         \
 103                             StrLength(Msg->IO.IOBuf) - 4);     \
 104                 StrBufTrim(Msg->MyQEntry->StatusMessage);      \
 105                 return eAbort; }                               \
 106         while (0)
 107
 108 #define SMTP_IS_STATE(WHICH_STATE) (ChrPtr(Msg->IO.IOBuf)[0] == WHICH_STATE)
 109
 110 #define SMTP_DBG_SEND() \
 111         EVS_syslog(LOG_DEBUG, "> %s\n", ChrPtr(Msg->IO.SendBuf.Buf))
 112
 113 #define SMTP_DBG_READ() \
 114         EVS_syslog(LOG_DEBUG, "< %s\n", ChrPtr(Msg->IO.IOBuf))
 115
 116
 117 /*****************************************************************************/
 118 /*                     SMTP CLIENT STATE CALLBACKS                           */
 119 /*****************************************************************************/
 120 eNextState SMTPC_read_greeting(SmtpOutMsg *Msg)
 121 {
 122         /* Process the SMTP greeting from the server */
 123         AsyncIO *IO = &Msg->IO;
 124         SMTP_DBG_READ();
 125         SetSMTPState(IO, eSTMPsmtp);
 126
 127         if (!SMTP_IS_STATE('2')) {
 128                 if (SMTP_IS_STATE('4'))
 129                         SMTP_VERROR(4);
 130                 else
 131                         SMTP_VERROR(5);
 132         }
 133         return eSendReply;
 134 }
 135
 136 eNextState SMTPC_send_EHLO(SmtpOutMsg *Msg)
 137 {
 138         AsyncIO *IO = &Msg->IO;
 139         /* At this point we know we are talking to a real SMTP server */
 140
 141         /* Do a EHLO command.  If it fails, try the HELO command. */
 142         StrBufPrintf(Msg->IO.SendBuf.Buf,
 143                      "EHLO %s\r\n", config.c_fqdn);
 144
 145         SMTP_DBG_SEND();
 146         return eReadMessage;
 147 }
 148
 149 eNextState SMTPC_read_EHLO_reply(SmtpOutMsg *Msg)
 150 {
 151         AsyncIO *IO = &Msg->IO;
 152         SMTP_DBG_READ();
 153
 154         if (SMTP_IS_STATE('2')) {
 155                 Msg->State ++;
 156
 157                 if ((Msg->pCurrRelay == NULL) ||
 158                     (Msg->pCurrRelay->User == NULL))
 159                         Msg->State ++; /* Skip auth... */
 160         }
 161         /* else we fall back to 'helo' */
 162         return eSendReply;
 163 }
 164
 165 eNextState STMPC_send_HELO(SmtpOutMsg *Msg)
 166 {
 167         AsyncIO *IO = &Msg->IO;
 168         StrBufPrintf(Msg->IO.SendBuf.Buf,
 169                      "HELO %s\r\n", config.c_fqdn);
 170
 171         SMTP_DBG_SEND();
 172         return eReadMessage;
 173 }
 174
 175 eNextState SMTPC_read_HELO_reply(SmtpOutMsg *Msg)
 176 {
 177         AsyncIO *IO = &Msg->IO;
 178         SMTP_DBG_READ();
 179
 180         if (!SMTP_IS_STATE('2'))
 181         {
 182                 if (SMTP_IS_STATE('4'))
 183                         SMTP_VERROR(4);
 184                 else
 185                         SMTP_VERROR(5);
 186         }
 187         if ((Msg->pCurrRelay == NULL) ||
 188             (Msg->pCurrRelay->User == NULL))
 189                 Msg->State ++; /* Skip auth... */
 190
 191         return eSendReply;
 192 }
 193
 194 eNextState SMTPC_send_auth(SmtpOutMsg *Msg)
 195 {
 196         AsyncIO *IO = &Msg->IO;
 197         char buf[SIZ];
 198         char encoded[1024];
 199
 200         if ((Msg->pCurrRelay == NULL) ||
 201             (Msg->pCurrRelay->User == NULL))
 202                 Msg->State ++; /* Skip auth, shouldn't even come here!... */
 203         else {
 204                 /* Do an AUTH command if necessary */
 205                 sprintf(buf, "%s%c%s%c%s",
 206                         Msg->pCurrRelay->User, '\0',
 207                         Msg->pCurrRelay->User, '\0',
 208                         Msg->pCurrRelay->Pass);
 209
 210                 CtdlEncodeBase64(encoded, buf,
 211                                  strlen(Msg->pCurrRelay->User) * 2 +
 212                                  strlen(Msg->pCurrRelay->Pass) + 2, 0);
 213
 214                 StrBufPrintf(Msg->IO.SendBuf.Buf,
 215                              "AUTH PLAIN %s\r\n", encoded);
 216         }
 217         SMTP_DBG_SEND();
 218         return eReadMessage;
 219 }
 220
 221 eNextState SMTPC_read_auth_reply(SmtpOutMsg *Msg)
 222 {
 223         AsyncIO *IO = &Msg->IO;
 224         /* Do an AUTH command if necessary */
 225
 226         SMTP_DBG_READ();
 227
 228         if (!SMTP_IS_STATE('2')) {
 229                 if (SMTP_IS_STATE('4'))
 230                         SMTP_VERROR(4);
 231                 else
 232                         SMTP_VERROR(5);
 233         }
 234         return eSendReply;
 235 }
 236
 237 eNextState SMTPC_send_FROM(SmtpOutMsg *Msg)
 238 {
 239         AsyncIO *IO = &Msg->IO;
 240         /* previous command succeeded, now try the MAIL FROM: command */
 241         StrBufPrintf(Msg->IO.SendBuf.Buf,
 242                      "MAIL FROM:<%s>\r\n",
 243                      Msg->envelope_from);
 244
 245         SMTP_DBG_SEND();
 246         return eReadMessage;
 247 }
 248
 249 eNextState SMTPC_read_FROM_reply(SmtpOutMsg *Msg)
 250 {
 251         AsyncIO *IO = &Msg->IO;
 252         SMTP_DBG_READ();
 253
 254         if (!SMTP_IS_STATE('2')) {
 255                 if (SMTP_IS_STATE('4'))
 256                         SMTP_VERROR(4);
 257                 else
 258                         SMTP_VERROR(5);
 259         }
 260         return eSendReply;
 261 }
 262
 263
 264 eNextState SMTPC_send_RCPT(SmtpOutMsg *Msg)
 265 {
 266         AsyncIO *IO = &Msg->IO;
 267         /* MAIL succeeded, now try the RCPT To: command */
 268         StrBufPrintf(Msg->IO.SendBuf.Buf,
 269                      "RCPT TO:<%s@%s>\r\n",
 270                      Msg->user,
 271                      Msg->node);
 272
 273         SMTP_DBG_SEND();
 274         return eReadMessage;
 275 }
 276
 277 eNextState SMTPC_read_RCPT_reply(SmtpOutMsg *Msg)
 278 {
 279         AsyncIO *IO = &Msg->IO;
 280         SMTP_DBG_READ();
 281
 282         if (!SMTP_IS_STATE('2')) {
 283                 if (SMTP_IS_STATE('4'))
 284                         SMTP_VERROR(4);
 285                 else
 286                         SMTP_VERROR(5);
 287         }
 288         return eSendReply;
 289 }
 290
 291 eNextState SMTPC_send_DATAcmd(SmtpOutMsg *Msg)
 292 {
 293         AsyncIO *IO = &Msg->IO;
 294         /* RCPT succeeded, now try the DATA command */
 295         StrBufPlain(Msg->IO.SendBuf.Buf,
 296                     HKEY("DATA\r\n"));
 297
 298         SMTP_DBG_SEND();
 299         return eReadMessage;
 300 }
 301
 302 eNextState SMTPC_read_DATAcmd_reply(SmtpOutMsg *Msg)
 303 {
 304         AsyncIO *IO = &Msg->IO;
 305         SMTP_DBG_READ();
 306
 307         if (!SMTP_IS_STATE('3')) {
 308                 SetSMTPState(IO, eSTMPfailOne);
 309                 if (SMTP_IS_STATE('4'))
 310                         SMTP_VERROR(3);
 311                 else
 312                         SMTP_VERROR(5);
 313         }
 314         SetSMTPState(IO, eSTMPsmtpdata);
 315         return eSendReply;
 316 }
 317
 318 eNextState SMTPC_send_data_body(SmtpOutMsg *Msg)
 319 {
 320         StrBuf *Buf;
 321         /* If we reach this point, the server is expecting data.*/
 322
 323         Buf = Msg->IO.SendBuf.Buf;
 324         Msg->IO.SendBuf.Buf = Msg->msgtext;
 325         Msg->msgtext = Buf;
 326         Msg->State ++;
 327
 328         return eSendMore;
 329 }
 330
 331 eNextState SMTPC_send_terminate_data_body(SmtpOutMsg *Msg)
 332 {
 333         StrBuf *Buf;
 334
 335         Buf = Msg->IO.SendBuf.Buf;
 336         Msg->IO.SendBuf.Buf = Msg->msgtext;
 337         Msg->msgtext = Buf;
 338
 339         StrBufPlain(Msg->IO.SendBuf.Buf,
 340                     HKEY(".\r\n"));
 341
 342         return eReadMessage;
 343
 344 }
 345
 346 eNextState SMTPC_read_data_body_reply(SmtpOutMsg *Msg)
 347 {
 348         AsyncIO *IO = &Msg->IO;
 349         SMTP_DBG_READ();
 350
 351         if (!SMTP_IS_STATE('2')) {
 352                 if (SMTP_IS_STATE('4'))
 353                         SMTP_VERROR(4);
 354                 else
 355                         SMTP_VERROR(5);
 356         }
 357
 358         SetSMTPState(IO, eSTMPsmtpdone);
 359         /* We did it! */
 360         StrBufPlain(Msg->MyQEntry->StatusMessage,
 361                     &ChrPtr(Msg->IO.RecvBuf.Buf)[4],
 362                     StrLength(Msg->IO.RecvBuf.Buf) - 4);
 363         StrBufTrim(Msg->MyQEntry->StatusMessage);
 364         Msg->MyQEntry->Status = 2;
 365         return eSendReply;
 366 }
 367
 368 eNextState SMTPC_send_QUIT(SmtpOutMsg *Msg)
 369 {
 370         AsyncIO *IO = &Msg->IO;
 371         StrBufPlain(Msg->IO.SendBuf.Buf,
 372                     HKEY("QUIT\r\n"));
 373
 374         SMTP_DBG_SEND();
 375         return eReadMessage;
 376 }
 377
 378 eNextState SMTPC_read_QUIT_reply(SmtpOutMsg *Msg)
 379 {
 380         AsyncIO *IO = &Msg->IO;
 381         SMTP_DBG_READ();
 382
 383         EVS_syslog(LOG_DEBUG,
 384                    "delivery to <%s> @ <%s> (%s) succeeded\n",
 385                    Msg->user,
 386                    Msg->node,
 387                    Msg->name);
 388
 389         return eTerminateConnection;
 390 }
 391
 392 eNextState SMTPC_read_dummy(SmtpOutMsg *Msg)
 393 {
 394         return eSendReply;
 395 }
 396
 397 eNextState SMTPC_send_dummy(SmtpOutMsg *Msg)
 398 {
 399         return eReadMessage;
 400 }
 401
 402 /*****************************************************************************/
 403 /*                     SMTP CLIENT DISPATCHER                                */
 404 /*****************************************************************************/
 405 SMTPReadHandler ReadHandlers[eMaxSMTPC] = {
 406         SMTPC_read_greeting,
 407         SMTPC_read_EHLO_reply,
 408         SMTPC_read_HELO_reply,
 409         SMTPC_read_auth_reply,
 410         SMTPC_read_FROM_reply,
 411         SMTPC_read_RCPT_reply,
 412         SMTPC_read_DATAcmd_reply,
 413         SMTPC_read_dummy,
 414         SMTPC_read_data_body_reply,
 415         SMTPC_read_QUIT_reply
 416 };
 417 SMTPSendHandler SendHandlers[eMaxSMTPC] = {
 418         SMTPC_send_dummy, /* we don't send a greeting, the server does... */
 419         SMTPC_send_EHLO,
 420         STMPC_send_HELO,
 421         SMTPC_send_auth,
 422         SMTPC_send_FROM,
 423         SMTPC_send_RCPT,
 424         SMTPC_send_DATAcmd,
 425         SMTPC_send_data_body,
 426         SMTPC_send_terminate_data_body,
 427         SMTPC_send_QUIT
 428 };
 429
 430 const double SMTP_C_ConnTimeout = 300.; /* wail 1 minute for connections... */
 431
 432 const double SMTP_C_ReadTimeouts[eMaxSMTPC] = {
 433         300., /* Greeting... */
 434         30., /* EHLO */
 435         30., /* HELO */
 436         30., /* Auth */
 437         30., /* From */
 438         90., /* RCPT */
 439         30., /* DATA */
 440         90., /* DATABody */
 441         90., /* end of body... */
 442         30.  /* QUIT */
 443 };
 444 const double SMTP_C_SendTimeouts[eMaxSMTPC] = {
 445         90., /* Greeting... */
 446         30., /* EHLO */
 447         30., /* HELO */
 448         30., /* Auth */
 449         30., /* From */
 450         30., /* RCPT */
 451         30., /* DATA */
 452         90., /* DATABody */
 453         900., /* end of body... */
 454         30.  /* QUIT */
 455 };
 456
 457 const ConstStr ReadErrors[eMaxSMTPC + 1] = {
 458         {HKEY("Connection broken during SMTP conversation")},
 459         {HKEY("Connection broken during SMTP EHLO")},
 460         {HKEY("Connection broken during SMTP HELO")},
 461         {HKEY("Connection broken during SMTP AUTH")},
 462         {HKEY("Connection broken during SMTP MAIL FROM")},
 463         {HKEY("Connection broken during SMTP RCPT")},
 464         {HKEY("Connection broken during SMTP DATA")},
 465         {HKEY("Connection broken during SMTP message transmit")},
 466         {HKEY("Connection broken during SMTP message transmit")},/* quit reply, don't care. */
 467         {HKEY("Connection broken during SMTP message transmit")},/* quit reply, don't care. */
 468         {HKEY("")}/* quit reply, don't care. */
 469 };
 470
 471
 472
 473
 474
 475 int smtp_resolve_recipients(SmtpOutMsg *Msg)
 476 {
 477         AsyncIO *IO = &Msg->IO;
 478         const char *ptr;
 479         char buf[1024];
 480         int scan_done;
 481         int lp, rp;
 482         int i;
 483
 484         EVNCS_syslog(LOG_DEBUG, "%s\n", __FUNCTION__);
 485
 486         if ((Msg==NULL) ||
 487             (Msg->MyQEntry == NULL) ||
 488             (StrLength(Msg->MyQEntry->Recipient) == 0)) {
 489                 return 0;
 490         }
 491
 492         /* Parse out the host portion of the recipient address */
 493         process_rfc822_addr(ChrPtr(Msg->MyQEntry->Recipient),
 494                             Msg->user,
 495                             Msg->node,
 496                             Msg->name);
 497
 498         EVNCS_syslog(LOG_DEBUG,
 499                      "Attempting delivery to <%s> @ <%s> (%s)\n",
 500                      Msg->user,
 501                      Msg->node,
 502                      Msg->name);
 503
 504         /* If no envelope_from is supplied, extract one from the message */
 505         Msg->envelope_from = ChrPtr(Msg->MyQItem->EnvelopeFrom);
 506         if ( (Msg->envelope_from == NULL) ||
 507              (IsEmptyStr(Msg->envelope_from)) ) {
 508                 Msg->mailfrom[0] = '\0';
 509                 scan_done = 0;
 510                 ptr = ChrPtr(Msg->msgtext);
 511                 do {
 512                         if (ptr = cmemreadline(ptr, buf, sizeof buf), *ptr == 0)
 513                         {
 514                                 scan_done = 1;
 515                         }
 516                         if (!strncasecmp(buf, "From:", 5))
 517                         {
 518                                 safestrncpy(Msg->mailfrom,
 519                                             &buf[5],
 520                                             sizeof Msg->mailfrom);
 521
 522                                 striplt(Msg->mailfrom);
 523                                 for (i=0; Msg->mailfrom[i]; ++i) {
 524                                         if (!isprint(Msg->mailfrom[i]))
 525                                         {
 526                                                 strcpy(&Msg->mailfrom[i],
 527                                                        &Msg->mailfrom[i+1]);
 528                                                 i=0;
 529                                         }
 530                                 }
 531
 532                                 /* Strip out parenthesized names */
 533                                 lp = (-1);
 534                                 rp = (-1);
 535                                 for (i=0;
 536                                      !IsEmptyStr(Msg->mailfrom + i);
 537                                      ++i)
 538                                 {
 539                                         if (Msg->mailfrom[i] == '(') lp = i;
 540                                         if (Msg->mailfrom[i] == ')') rp = i;
 541                                 }
 542                                 if ((lp>0)&&(rp>lp))
 543                                 {
 544                                         strcpy(&Msg->mailfrom[lp-1],
 545                                                &Msg->mailfrom[rp+1]);
 546                                 }
 547
 548                                 /* Prefer brokketized names */
 549                                 lp = (-1);
 550                                 rp = (-1);
 551                                 for (i=0;
 552                                      !IsEmptyStr(Msg->mailfrom + i);
 553                                      ++i)
 554                                 {
 555                                         if (Msg->mailfrom[i] == '<') lp = i;
 556                                         if (Msg->mailfrom[i] == '>') rp = i;
 557                                 }
 558                                 if ( (lp>=0) && (rp>lp) ) {
 559                                         Msg->mailfrom[rp] = 0;
 560                                         memmove(Msg->mailfrom,
 561                                                 &Msg->mailfrom[lp + 1],
 562                                                 rp - lp);
 563                                 }
 564
 565                                 scan_done = 1;
 566                         }
 567                 } while (scan_done == 0);
 568                 if (IsEmptyStr(Msg->mailfrom))
 569                         strcpy(Msg->mailfrom, "someone@somewhere.org");
 570
 571                 stripallbut(Msg->mailfrom, '<', '>');
 572                 Msg->envelope_from = Msg->mailfrom;
 573         }
 574
 575         return 1;
 576 }