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
 126         if (!SMTP_IS_STATE('2')) {
 127                 if (SMTP_IS_STATE('4'))
 128                         SMTP_VERROR(4);
 129                 else
 130                         SMTP_VERROR(5);
 131         }
 132         return eSendReply;
 133 }
 134
 135 eNextState SMTPC_send_EHLO(SmtpOutMsg *Msg)
 136 {
 137         AsyncIO *IO = &Msg->IO;
 138         /* At this point we know we are talking to a real SMTP server */
 139
 140         /* Do a EHLO command.  If it fails, try the HELO command. */
 141         StrBufPrintf(Msg->IO.SendBuf.Buf,
 142                      "EHLO %s\r\n", config.c_fqdn);
 143
 144         SMTP_DBG_SEND();
 145         return eReadMessage;
 146 }
 147
 148 eNextState SMTPC_read_EHLO_reply(SmtpOutMsg *Msg)
 149 {
 150         AsyncIO *IO = &Msg->IO;
 151         SMTP_DBG_READ();
 152
 153         if (SMTP_IS_STATE('2')) {
 154                 Msg->State ++;
 155
 156                 if ((Msg->pCurrRelay == NULL) ||
 157                     (Msg->pCurrRelay->User == NULL))
 158                         Msg->State ++; /* Skip auth... */
 159         }
 160         /* else we fall back to 'helo' */
 161         return eSendReply;
 162 }
 163
 164 eNextState STMPC_send_HELO(SmtpOutMsg *Msg)
 165 {
 166         AsyncIO *IO = &Msg->IO;
 167         StrBufPrintf(Msg->IO.SendBuf.Buf,
 168                      "HELO %s\r\n", config.c_fqdn);
 169
 170         SMTP_DBG_SEND();
 171         return eReadMessage;
 172 }
 173
 174 eNextState SMTPC_read_HELO_reply(SmtpOutMsg *Msg)
 175 {
 176         AsyncIO *IO = &Msg->IO;
 177         SMTP_DBG_READ();
 178
 179         if (!SMTP_IS_STATE('2'))
 180         {
 181                 if (SMTP_IS_STATE('4'))
 182                         SMTP_VERROR(4);
 183                 else
 184                         SMTP_VERROR(5);
 185         }
 186         if ((Msg->pCurrRelay == NULL) ||
 187             (Msg->pCurrRelay->User == NULL))
 188                 Msg->State ++; /* Skip auth... */
 189
 190         return eSendReply;
 191 }
 192
 193 eNextState SMTPC_send_auth(SmtpOutMsg *Msg)
 194 {
 195         AsyncIO *IO = &Msg->IO;
 196         char buf[SIZ];
 197         char encoded[1024];
 198
 199         if ((Msg->pCurrRelay == NULL) ||
 200             (Msg->pCurrRelay->User == NULL))
 201                 Msg->State ++; /* Skip auth, shouldn't even come here!... */
 202         else {
 203                 /* Do an AUTH command if necessary */
 204                 sprintf(buf, "%s%c%s%c%s",
 205                         Msg->pCurrRelay->User, '\0',
 206                         Msg->pCurrRelay->User, '\0',
 207                         Msg->pCurrRelay->Pass);
 208
 209                 CtdlEncodeBase64(encoded, buf,
 210                                  strlen(Msg->pCurrRelay->User) * 2 +
 211                                  strlen(Msg->pCurrRelay->Pass) + 2, 0);
 212
 213                 StrBufPrintf(Msg->IO.SendBuf.Buf,
 214                              "AUTH PLAIN %s\r\n", encoded);
 215         }
 216         SMTP_DBG_SEND();
 217         return eReadMessage;
 218 }
 219
 220 eNextState SMTPC_read_auth_reply(SmtpOutMsg *Msg)
 221 {
 222         AsyncIO *IO = &Msg->IO;
 223         /* Do an AUTH command if necessary */
 224
 225         SMTP_DBG_READ();
 226
 227         if (!SMTP_IS_STATE('2')) {
 228                 if (SMTP_IS_STATE('4'))
 229                         SMTP_VERROR(4);
 230                 else
 231                         SMTP_VERROR(5);
 232         }
 233         return eSendReply;
 234 }
 235
 236 eNextState SMTPC_send_FROM(SmtpOutMsg *Msg)
 237 {
 238         AsyncIO *IO = &Msg->IO;
 239         /* previous command succeeded, now try the MAIL FROM: command */
 240         StrBufPrintf(Msg->IO.SendBuf.Buf,
 241                      "MAIL FROM:<%s>\r\n",
 242                      Msg->envelope_from);
 243
 244         SMTP_DBG_SEND();
 245         return eReadMessage;
 246 }
 247
 248 eNextState SMTPC_read_FROM_reply(SmtpOutMsg *Msg)
 249 {
 250         AsyncIO *IO = &Msg->IO;
 251         SMTP_DBG_READ();
 252
 253         if (!SMTP_IS_STATE('2')) {
 254                 if (SMTP_IS_STATE('4'))
 255                         SMTP_VERROR(4);
 256                 else
 257                         SMTP_VERROR(5);
 258         }
 259         return eSendReply;
 260 }
 261
 262
 263 eNextState SMTPC_send_RCPT(SmtpOutMsg *Msg)
 264 {
 265         AsyncIO *IO = &Msg->IO;
 266         /* MAIL succeeded, now try the RCPT To: command */
 267         StrBufPrintf(Msg->IO.SendBuf.Buf,
 268                      "RCPT TO:<%s@%s>\r\n",
 269                      Msg->user,
 270                      Msg->node);
 271
 272         SMTP_DBG_SEND();
 273         return eReadMessage;
 274 }
 275
 276 eNextState SMTPC_read_RCPT_reply(SmtpOutMsg *Msg)
 277 {
 278         AsyncIO *IO = &Msg->IO;
 279         SMTP_DBG_READ();
 280
 281         if (!SMTP_IS_STATE('2')) {
 282                 if (SMTP_IS_STATE('4'))
 283                         SMTP_VERROR(4);
 284                 else
 285                         SMTP_VERROR(5);
 286         }
 287         return eSendReply;
 288 }
 289
 290 eNextState SMTPC_send_DATAcmd(SmtpOutMsg *Msg)
 291 {
 292         AsyncIO *IO = &Msg->IO;
 293         /* RCPT succeeded, now try the DATA command */
 294         StrBufPlain(Msg->IO.SendBuf.Buf,
 295                     HKEY("DATA\r\n"));
 296
 297         SMTP_DBG_SEND();
 298         return eReadMessage;
 299 }
 300
 301 eNextState SMTPC_read_DATAcmd_reply(SmtpOutMsg *Msg)
 302 {
 303         AsyncIO *IO = &Msg->IO;
 304         SMTP_DBG_READ();
 305
 306         if (!SMTP_IS_STATE('3')) {
 307                 if (SMTP_IS_STATE('4'))
 308                         SMTP_VERROR(3);
 309                 else
 310                         SMTP_VERROR(5);
 311         }
 312         return eSendReply;
 313 }
 314
 315 eNextState SMTPC_send_data_body(SmtpOutMsg *Msg)
 316 {
 317         StrBuf *Buf;
 318         /* If we reach this point, the server is expecting data.*/
 319
 320         Buf = Msg->IO.SendBuf.Buf;
 321         Msg->IO.SendBuf.Buf = Msg->msgtext;
 322         Msg->msgtext = Buf;
 323         Msg->State ++;
 324
 325         return eSendMore;
 326 }
 327
 328 eNextState SMTPC_send_terminate_data_body(SmtpOutMsg *Msg)
 329 {
 330         StrBuf *Buf;
 331
 332         Buf = Msg->IO.SendBuf.Buf;
 333         Msg->IO.SendBuf.Buf = Msg->msgtext;
 334         Msg->msgtext = Buf;
 335
 336         StrBufPlain(Msg->IO.SendBuf.Buf,
 337                     HKEY(".\r\n"));
 338
 339         return eReadMessage;
 340
 341 }
 342
 343 eNextState SMTPC_read_data_body_reply(SmtpOutMsg *Msg)
 344 {
 345         AsyncIO *IO = &Msg->IO;
 346         SMTP_DBG_READ();
 347
 348         if (!SMTP_IS_STATE('2')) {
 349                 if (SMTP_IS_STATE('4'))
 350                         SMTP_VERROR(4);
 351                 else
 352                         SMTP_VERROR(5);
 353         }
 354
 355         /* We did it! */
 356         StrBufPlain(Msg->MyQEntry->StatusMessage,
 357                     &ChrPtr(Msg->IO.RecvBuf.Buf)[4],
 358                     StrLength(Msg->IO.RecvBuf.Buf) - 4);
 359         StrBufTrim(Msg->MyQEntry->StatusMessage);
 360         Msg->MyQEntry->Status = 2;
 361         return eSendReply;
 362 }
 363
 364 eNextState SMTPC_send_QUIT(SmtpOutMsg *Msg)
 365 {
 366         AsyncIO *IO = &Msg->IO;
 367         StrBufPlain(Msg->IO.SendBuf.Buf,
 368                     HKEY("QUIT\r\n"));
 369
 370         SMTP_DBG_SEND();
 371         return eReadMessage;
 372 }
 373
 374 eNextState SMTPC_read_QUIT_reply(SmtpOutMsg *Msg)
 375 {
 376         AsyncIO *IO = &Msg->IO;
 377         SMTP_DBG_READ();
 378
 379         EVS_syslog(LOG_DEBUG,
 380                    "delivery to <%s> @ <%s> (%s) succeeded\n",
 381                    Msg->user,
 382                    Msg->node,
 383                    Msg->name);
 384
 385         return eTerminateConnection;
 386 }
 387
 388 eNextState SMTPC_read_dummy(SmtpOutMsg *Msg)
 389 {
 390         return eSendReply;
 391 }
 392
 393 eNextState SMTPC_send_dummy(SmtpOutMsg *Msg)
 394 {
 395         return eReadMessage;
 396 }
 397
 398 /*****************************************************************************/
 399 /*                     SMTP CLIENT DISPATCHER                                */
 400 /*****************************************************************************/
 401 SMTPReadHandler ReadHandlers[eMaxSMTPC] = {
 402         SMTPC_read_greeting,
 403         SMTPC_read_EHLO_reply,
 404         SMTPC_read_HELO_reply,
 405         SMTPC_read_auth_reply,
 406         SMTPC_read_FROM_reply,
 407         SMTPC_read_RCPT_reply,
 408         SMTPC_read_DATAcmd_reply,
 409         SMTPC_read_dummy,
 410         SMTPC_read_data_body_reply,
 411         SMTPC_read_QUIT_reply
 412 };
 413 SMTPSendHandler SendHandlers[eMaxSMTPC] = {
 414         SMTPC_send_dummy, /* we don't send a greeting, the server does... */
 415         SMTPC_send_EHLO,
 416         STMPC_send_HELO,
 417         SMTPC_send_auth,
 418         SMTPC_send_FROM,
 419         SMTPC_send_RCPT,
 420         SMTPC_send_DATAcmd,
 421         SMTPC_send_data_body,
 422         SMTPC_send_terminate_data_body,
 423         SMTPC_send_QUIT
 424 };
 425
 426 const double SMTP_C_ConnTimeout = 300.; /* wail 1 minute for connections... */
 427
 428 const double SMTP_C_ReadTimeouts[eMaxSMTPC] = {
 429         300., /* Greeting... */
 430         30., /* EHLO */
 431         30., /* HELO */
 432         30., /* Auth */
 433         30., /* From */
 434         90., /* RCPT */
 435         30., /* DATA */
 436         90., /* DATABody */
 437         90., /* end of body... */
 438         30.  /* QUIT */
 439 };
 440 const double SMTP_C_SendTimeouts[eMaxSMTPC] = {
 441         90., /* Greeting... */
 442         30., /* EHLO */
 443         30., /* HELO */
 444         30., /* Auth */
 445         30., /* From */
 446         30., /* RCPT */
 447         30., /* DATA */
 448         90., /* DATABody */
 449         900., /* end of body... */
 450         30.  /* QUIT */
 451 };
 452
 453 const ConstStr ReadErrors[eMaxSMTPC + 1] = {
 454         {HKEY("Connection broken during SMTP conversation")},
 455         {HKEY("Connection broken during SMTP EHLO")},
 456         {HKEY("Connection broken during SMTP HELO")},
 457         {HKEY("Connection broken during SMTP AUTH")},
 458         {HKEY("Connection broken during SMTP MAIL FROM")},
 459         {HKEY("Connection broken during SMTP RCPT")},
 460         {HKEY("Connection broken during SMTP DATA")},
 461         {HKEY("Connection broken during SMTP message transmit")},
 462         {HKEY("Connection broken during SMTP message transmit")},/* quit reply, don't care. */
 463         {HKEY("Connection broken during SMTP message transmit")},/* quit reply, don't care. */
 464         {HKEY("")}/* quit reply, don't care. */
 465 };
 466
 467
 468
 469
 470
 471 int smtp_resolve_recipients(SmtpOutMsg *Msg)
 472 {
 473         AsyncIO *IO = &Msg->IO;
 474         const char *ptr;
 475         char buf[1024];
 476         int scan_done;
 477         int lp, rp;
 478         int i;
 479
 480         EVNCS_syslog(LOG_DEBUG, "%s\n", __FUNCTION__);
 481
 482         if ((Msg==NULL) ||
 483             (Msg->MyQEntry == NULL) ||
 484             (StrLength(Msg->MyQEntry->Recipient) == 0)) {
 485                 return 0;
 486         }
 487
 488         /* Parse out the host portion of the recipient address */
 489         process_rfc822_addr(ChrPtr(Msg->MyQEntry->Recipient),
 490                             Msg->user,
 491                             Msg->node,
 492                             Msg->name);
 493
 494         EVNCS_syslog(LOG_DEBUG,
 495                      "Attempting delivery to <%s> @ <%s> (%s)\n",
 496                      Msg->user,
 497                      Msg->node,
 498                      Msg->name);
 499
 500         /* If no envelope_from is supplied, extract one from the message */
 501         Msg->envelope_from = ChrPtr(Msg->MyQItem->EnvelopeFrom);
 502         if ( (Msg->envelope_from == NULL) ||
 503              (IsEmptyStr(Msg->envelope_from)) ) {
 504                 Msg->mailfrom[0] = '\0';
 505                 scan_done = 0;
 506                 ptr = ChrPtr(Msg->msgtext);
 507                 do {
 508                         if (ptr = cmemreadline(ptr, buf, sizeof buf), *ptr == 0)
 509                         {
 510                                 scan_done = 1;
 511                         }
 512                         if (!strncasecmp(buf, "From:", 5))
 513                         {
 514                                 safestrncpy(Msg->mailfrom,
 515                                             &buf[5],
 516                                             sizeof Msg->mailfrom);
 517
 518                                 striplt(Msg->mailfrom);
 519                                 for (i=0; Msg->mailfrom[i]; ++i) {
 520                                         if (!isprint(Msg->mailfrom[i]))
 521                                         {
 522                                                 strcpy(&Msg->mailfrom[i],
 523                                                        &Msg->mailfrom[i+1]);
 524                                                 i=0;
 525                                         }
 526                                 }
 527
 528                                 /* Strip out parenthesized names */
 529                                 lp = (-1);
 530                                 rp = (-1);
 531                                 for (i=0;
 532                                      !IsEmptyStr(Msg->mailfrom + i);
 533                                      ++i)
 534                                 {
 535                                         if (Msg->mailfrom[i] == '(') lp = i;
 536                                         if (Msg->mailfrom[i] == ')') rp = i;
 537                                 }
 538                                 if ((lp>0)&&(rp>lp))
 539                                 {
 540                                         strcpy(&Msg->mailfrom[lp-1],
 541                                                &Msg->mailfrom[rp+1]);
 542                                 }
 543
 544                                 /* Prefer brokketized names */
 545                                 lp = (-1);
 546                                 rp = (-1);
 547                                 for (i=0;
 548                                      !IsEmptyStr(Msg->mailfrom + i);
 549                                      ++i)
 550                                 {
 551                                         if (Msg->mailfrom[i] == '<') lp = i;
 552                                         if (Msg->mailfrom[i] == '>') rp = i;
 553                                 }
 554                                 if ( (lp>=0) && (rp>lp) ) {
 555                                         Msg->mailfrom[rp] = 0;
 556                                         memmove(Msg->mailfrom,
 557                                                 &Msg->mailfrom[lp + 1],
 558                                                 rp - lp);
 559                                 }
 560
 561                                 scan_done = 1;
 562                         }
 563                 } while (scan_done == 0);
 564                 if (IsEmptyStr(Msg->mailfrom))
 565                         strcpy(Msg->mailfrom, "someone@somewhere.org");
 566
 567                 stripallbut(Msg->mailfrom, '<', '>');
 568                 Msg->envelope_from = Msg->mailfrom;
 569         }
 570
 571         return 1;
 572 }