1 /* 2 * Copyright (c) 1983 Eric P. Allman 3 * Copyright (c) 1988 Regents of the University of California. 4 * All rights reserved. 5 * 6 * %sccs.include.redist.c% 7 */ 8 9 # include "sendmail.h" 10 11 #ifndef lint 12 #ifdef SMTP 13 static char sccsid[] = "@(#)srvrsmtp.c 6.3 (Berkeley) 01/21/93 (with SMTP)"; 14 #else 15 static char sccsid[] = "@(#)srvrsmtp.c 6.3 (Berkeley) 01/21/93 (without SMTP)"; 16 #endif 17 #endif /* not lint */ 18 19 # include <errno.h> 20 # include <signal.h> 21 22 # ifdef SMTP 23 24 /* 25 ** SMTP -- run the SMTP protocol. 26 ** 27 ** Parameters: 28 ** none. 29 ** 30 ** Returns: 31 ** never. 32 ** 33 ** Side Effects: 34 ** Reads commands from the input channel and processes 35 ** them. 36 */ 37 38 struct cmd 39 { 40 char *cmdname; /* command name */ 41 int cmdcode; /* internal code, see below */ 42 }; 43 44 /* values for cmdcode */ 45 # define CMDERROR 0 /* bad command */ 46 # define CMDMAIL 1 /* mail -- designate sender */ 47 # define CMDRCPT 2 /* rcpt -- designate recipient */ 48 # define CMDDATA 3 /* data -- send message text */ 49 # define CMDRSET 4 /* rset -- reset state */ 50 # define CMDVRFY 5 /* vrfy -- verify address */ 51 # define CMDHELP 6 /* help -- give usage info */ 52 # define CMDNOOP 7 /* noop -- do nothing */ 53 # define CMDQUIT 8 /* quit -- close connection and die */ 54 # define CMDHELO 9 /* helo -- be polite */ 55 # define CMDONEX 10 /* onex -- sending one transaction only */ 56 # define CMDVERB 11 /* verb -- go into verbose mode */ 57 /* debugging-only commands, only enabled if SMTPDEBUG is defined */ 58 # define CMDDBGQSHOW 12 /* showq -- show send queue */ 59 # define CMDDBGDEBUG 13 /* debug -- set debug mode */ 60 61 static struct cmd CmdTab[] = 62 { 63 "mail", CMDMAIL, 64 "rcpt", CMDRCPT, 65 "data", CMDDATA, 66 "rset", CMDRSET, 67 "vrfy", CMDVRFY, 68 "expn", CMDVRFY, 69 "help", CMDHELP, 70 "noop", CMDNOOP, 71 "quit", CMDQUIT, 72 "helo", CMDHELO, 73 "verb", CMDVERB, 74 "onex", CMDONEX, 75 /* 76 * remaining commands are here only 77 * to trap and log attempts to use them 78 */ 79 "showq", CMDDBGQSHOW, 80 "debug", CMDDBGDEBUG, 81 NULL, CMDERROR, 82 }; 83 84 bool InChild = FALSE; /* true if running in a subprocess */ 85 bool OneXact = FALSE; /* one xaction only this run */ 86 87 #define EX_QUIT 22 /* special code for QUIT command */ 88 89 smtp(e) 90 register ENVELOPE *e; 91 { 92 register char *p; 93 register struct cmd *c; 94 char *cmd; 95 static char *skipword(); 96 bool hasmail; /* mail command received */ 97 auto ADDRESS *vrfyqueue; 98 ADDRESS *a; 99 char *sendinghost; 100 char inp[MAXLINE]; 101 char cmdbuf[MAXLINE]; 102 extern char Version[]; 103 extern char *macvalue(); 104 extern ADDRESS *recipient(); 105 extern ENVELOPE BlankEnvelope; 106 extern ENVELOPE *newenvelope(); 107 108 hasmail = FALSE; 109 if (OutChannel != stdout) 110 { 111 /* arrange for debugging output to go to remote host */ 112 (void) close(1); 113 (void) dup(fileno(OutChannel)); 114 } 115 settime(e); 116 if (RealHostName == NULL) 117 RealHostName = MyHostName; 118 CurHostName = RealHostName; 119 setproctitle("srvrsmtp %s", CurHostName); 120 expand("\001e", inp, &inp[sizeof inp], e); 121 message("220", "%s", inp); 122 SmtpPhase = "startup"; 123 sendinghost = NULL; 124 for (;;) 125 { 126 /* arrange for backout */ 127 if (setjmp(TopFrame) > 0 && InChild) 128 finis(); 129 QuickAbort = FALSE; 130 HoldErrs = FALSE; 131 LogUsrErrs = FALSE; 132 133 /* setup for the read */ 134 e->e_to = NULL; 135 Errors = 0; 136 (void) fflush(stdout); 137 138 /* read the input line */ 139 p = sfgets(inp, sizeof inp, InChannel, ReadTimeout); 140 141 /* handle errors */ 142 if (p == NULL) 143 { 144 /* end of file, just die */ 145 message("421", "%s Lost input channel from %s", 146 MyHostName, CurHostName); 147 #ifdef LOG 148 if (LogLevel >= 4) 149 syslog(LOG_NOTICE, "lost input channel from %s", 150 CurHostName); 151 #endif 152 finis(); 153 } 154 155 /* clean up end of line */ 156 fixcrlf(inp, TRUE); 157 158 /* echo command to transcript */ 159 if (e->e_xfp != NULL) 160 fprintf(e->e_xfp, "<<< %s\n", inp); 161 162 /* break off command */ 163 for (p = inp; isspace(*p); p++) 164 continue; 165 cmd = cmdbuf; 166 while (*p != '\0' && !isspace(*p) && cmd < &cmdbuf[sizeof cmdbuf - 2]) 167 *cmd++ = *p++; 168 *cmd = '\0'; 169 170 /* throw away leading whitespace */ 171 while (isspace(*p)) 172 p++; 173 174 /* decode command */ 175 for (c = CmdTab; c->cmdname != NULL; c++) 176 { 177 if (!strcasecmp(c->cmdname, cmdbuf)) 178 break; 179 } 180 181 /* reset errors */ 182 errno = 0; 183 184 /* process command */ 185 switch (c->cmdcode) 186 { 187 case CMDHELO: /* hello -- introduce yourself */ 188 SmtpPhase = "HELO"; 189 setproctitle("%s: %s", CurHostName, inp); 190 if (!strcasecmp(p, MyHostName)) 191 { 192 /* 193 * didn't know about alias, 194 * or connected to an echo server 195 */ 196 message("553", "%s config error: mail loops back to myself", 197 MyHostName); 198 break; 199 } 200 if (RealHostName != NULL && strcasecmp(p, RealHostName)) 201 { 202 char hostbuf[MAXNAME]; 203 204 (void) sprintf(hostbuf, "%s (%s)", p, RealHostName); 205 sendinghost = newstr(hostbuf); 206 } 207 else 208 sendinghost = newstr(p); 209 message("250", "%s Hello %s, pleased to meet you", 210 MyHostName, sendinghost); 211 break; 212 213 case CMDMAIL: /* mail -- designate sender */ 214 SmtpPhase = "MAIL"; 215 216 /* force a sending host even if no HELO given */ 217 if (RealHostName != NULL && macvalue('s', e) == NULL) 218 sendinghost = RealHostName; 219 220 /* check for validity of this command */ 221 if (hasmail) 222 { 223 message("503", "Sender already specified"); 224 break; 225 } 226 if (InChild) 227 { 228 errno = 0; 229 syserr("Nested MAIL command"); 230 exit(0); 231 } 232 233 /* fork a subprocess to process this command */ 234 if (runinchild("SMTP-MAIL", e) > 0) 235 break; 236 define('s', sendinghost, e); 237 define('r', "SMTP", e); 238 initsys(e); 239 setproctitle("%s %s: %s", e->e_id, CurHostName, inp); 240 241 /* child -- go do the processing */ 242 p = skipword(p, "from"); 243 if (p == NULL) 244 break; 245 setsender(p, e); 246 if (Errors == 0) 247 { 248 message("250", "Sender ok"); 249 hasmail = TRUE; 250 } 251 else if (InChild) 252 finis(); 253 break; 254 255 case CMDRCPT: /* rcpt -- designate recipient */ 256 SmtpPhase = "RCPT"; 257 setproctitle("%s %s: %s", e->e_id, CurHostName, inp); 258 if (setjmp(TopFrame) > 0) 259 { 260 e->e_flags &= ~EF_FATALERRS; 261 break; 262 } 263 QuickAbort = TRUE; 264 LogUsrErrs = TRUE; 265 p = skipword(p, "to"); 266 if (p == NULL) 267 break; 268 a = parseaddr(p, (ADDRESS *) NULL, 1, '\0', e); 269 if (a == NULL) 270 break; 271 a->q_flags |= QPRIMARY; 272 a = recipient(a, &e->e_sendqueue, e); 273 if (Errors != 0) 274 break; 275 276 /* no errors during parsing, but might be a duplicate */ 277 e->e_to = p; 278 if (!bitset(QBADADDR, a->q_flags)) 279 message("250", "Recipient ok"); 280 else 281 { 282 /* punt -- should keep message in ADDRESS.... */ 283 message("550", "Addressee unknown"); 284 } 285 e->e_to = NULL; 286 break; 287 288 case CMDDATA: /* data -- text of mail */ 289 SmtpPhase = "DATA"; 290 if (!hasmail) 291 { 292 message("503", "Need MAIL command"); 293 break; 294 } 295 else if (e->e_nrcpts <= 0) 296 { 297 message("503", "Need RCPT (recipient)"); 298 break; 299 } 300 301 /* collect the text of the message */ 302 SmtpPhase = "collect"; 303 setproctitle("%s %s: %s", e->e_id, CurHostName, inp); 304 collect(TRUE, e); 305 if (Errors != 0) 306 break; 307 308 /* 309 ** Arrange to send to everyone. 310 ** If sending to multiple people, mail back 311 ** errors rather than reporting directly. 312 ** In any case, don't mail back errors for 313 ** anything that has happened up to 314 ** now (the other end will do this). 315 ** Truncate our transcript -- the mail has gotten 316 ** to us successfully, and if we have 317 ** to mail this back, it will be easier 318 ** on the reader. 319 ** Then send to everyone. 320 ** Finally give a reply code. If an error has 321 ** already been given, don't mail a 322 ** message back. 323 ** We goose error returns by clearing error bit. 324 */ 325 326 SmtpPhase = "delivery"; 327 if (e->e_nrcpts != 1) 328 { 329 HoldErrs = TRUE; 330 ErrorMode = EM_MAIL; 331 } 332 e->e_flags &= ~EF_FATALERRS; 333 e->e_xfp = freopen(queuename(e, 'x'), "w", e->e_xfp); 334 335 /* send to all recipients */ 336 sendall(e, SM_DEFAULT); 337 e->e_to = NULL; 338 339 /* save statistics */ 340 markstats(e, (ADDRESS *) NULL); 341 342 /* issue success if appropriate and reset */ 343 if (Errors == 0 || HoldErrs) 344 message("250", "Ok"); 345 else 346 e->e_flags &= ~EF_FATALERRS; 347 348 /* if in a child, pop back to our parent */ 349 if (InChild) 350 finis(); 351 352 /* clean up a bit */ 353 hasmail = 0; 354 dropenvelope(e); 355 CurEnv = e = newenvelope(e); 356 e->e_flags = BlankEnvelope.e_flags; 357 break; 358 359 case CMDRSET: /* rset -- reset state */ 360 message("250", "Reset state"); 361 if (InChild) 362 finis(); 363 break; 364 365 case CMDVRFY: /* vrfy -- verify address */ 366 if (runinchild("SMTP-VRFY", e) > 0) 367 break; 368 setproctitle("%s: %s", CurHostName, inp); 369 #ifdef LOG 370 if (LogLevel >= 9) 371 syslog(LOG_INFO, "%s: %s", CurHostName, inp); 372 #endif 373 vrfyqueue = NULL; 374 QuickAbort = TRUE; 375 sendtolist(p, (ADDRESS *) NULL, &vrfyqueue, e); 376 if (Errors != 0) 377 { 378 if (InChild) 379 finis(); 380 break; 381 } 382 while (vrfyqueue != NULL) 383 { 384 register ADDRESS *a = vrfyqueue->q_next; 385 char *code; 386 387 while (a != NULL && bitset(QDONTSEND|QBADADDR, a->q_flags)) 388 a = a->q_next; 389 390 if (!bitset(QDONTSEND|QBADADDR, vrfyqueue->q_flags)) 391 { 392 if (a != NULL) 393 code = "250-"; 394 else 395 code = "250"; 396 if (vrfyqueue->q_fullname == NULL) 397 message(code, "<%s>", vrfyqueue->q_paddr); 398 else 399 message(code, "%s <%s>", 400 vrfyqueue->q_fullname, vrfyqueue->q_paddr); 401 } 402 else if (a == NULL) 403 message("554", "Self destructive alias loop"); 404 vrfyqueue = a; 405 } 406 if (InChild) 407 finis(); 408 break; 409 410 case CMDHELP: /* help -- give user info */ 411 help(p); 412 break; 413 414 case CMDNOOP: /* noop -- do nothing */ 415 message("200", "OK"); 416 break; 417 418 case CMDQUIT: /* quit -- leave mail */ 419 message("221", "%s closing connection", MyHostName); 420 if (InChild) 421 ExitStat = EX_QUIT; 422 finis(); 423 424 case CMDVERB: /* set verbose mode */ 425 Verbose = TRUE; 426 SendMode = SM_DELIVER; 427 message("200", "Verbose mode"); 428 break; 429 430 case CMDONEX: /* doing one transaction only */ 431 OneXact = TRUE; 432 message("200", "Only one transaction"); 433 break; 434 435 # ifdef SMTPDEBUG 436 case CMDDBGQSHOW: /* show queues */ 437 printf("Send Queue="); 438 printaddr(e->e_sendqueue, TRUE); 439 break; 440 441 case CMDDBGDEBUG: /* set debug mode */ 442 tTsetup(tTdvect, sizeof tTdvect, "0-99.1"); 443 tTflag(p); 444 message("200", "Debug set"); 445 break; 446 447 # else /* not SMTPDEBUG */ 448 449 case CMDDBGQSHOW: /* show queues */ 450 case CMDDBGDEBUG: /* set debug mode */ 451 # ifdef LOG 452 if (RealHostName != NULL && LogLevel > 0) 453 syslog(LOG_NOTICE, 454 "\"%s\" command from %s (%s)\n", 455 c->cmdname, RealHostName, 456 inet_ntoa(RealHostAddr.sin_addr)); 457 # endif 458 /* FALL THROUGH */ 459 # endif /* SMTPDEBUG */ 460 461 case CMDERROR: /* unknown command */ 462 message("500", "Command unrecognized"); 463 break; 464 465 default: 466 errno = 0; 467 syserr("smtp: unknown code %d", c->cmdcode); 468 break; 469 } 470 } 471 } 472 /* 473 ** SKIPWORD -- skip a fixed word. 474 ** 475 ** Parameters: 476 ** p -- place to start looking. 477 ** w -- word to skip. 478 ** 479 ** Returns: 480 ** p following w. 481 ** NULL on error. 482 ** 483 ** Side Effects: 484 ** clobbers the p data area. 485 */ 486 487 static char * 488 skipword(p, w) 489 register char *p; 490 char *w; 491 { 492 register char *q; 493 494 /* find beginning of word */ 495 while (isspace(*p)) 496 p++; 497 q = p; 498 499 /* find end of word */ 500 while (*p != '\0' && *p != ':' && !isspace(*p)) 501 p++; 502 while (isspace(*p)) 503 *p++ = '\0'; 504 if (*p != ':') 505 { 506 syntax: 507 message("501", "Syntax error"); 508 Errors++; 509 return (NULL); 510 } 511 *p++ = '\0'; 512 while (isspace(*p)) 513 p++; 514 515 /* see if the input word matches desired word */ 516 if (strcasecmp(q, w)) 517 goto syntax; 518 519 return (p); 520 } 521 /* 522 ** HELP -- implement the HELP command. 523 ** 524 ** Parameters: 525 ** topic -- the topic we want help for. 526 ** 527 ** Returns: 528 ** none. 529 ** 530 ** Side Effects: 531 ** outputs the help file to message output. 532 */ 533 534 help(topic) 535 char *topic; 536 { 537 register FILE *hf; 538 int len; 539 char buf[MAXLINE]; 540 bool noinfo; 541 542 if (HelpFile == NULL || (hf = fopen(HelpFile, "r")) == NULL) 543 { 544 /* no help */ 545 errno = 0; 546 message("502", "HELP not implemented"); 547 return; 548 } 549 550 if (topic == NULL || *topic == '\0') 551 topic = "smtp"; 552 else 553 makelower(topic); 554 555 len = strlen(topic); 556 noinfo = TRUE; 557 558 while (fgets(buf, sizeof buf, hf) != NULL) 559 { 560 if (strncmp(buf, topic, len) == 0) 561 { 562 register char *p; 563 564 p = strchr(buf, '\t'); 565 if (p == NULL) 566 p = buf; 567 else 568 p++; 569 fixcrlf(p, TRUE); 570 message("214-", p); 571 noinfo = FALSE; 572 } 573 } 574 575 if (noinfo) 576 message("504", "HELP topic unknown"); 577 else 578 message("214", "End of HELP info"); 579 (void) fclose(hf); 580 } 581 /* 582 ** RUNINCHILD -- return twice -- once in the child, then in the parent again 583 ** 584 ** Parameters: 585 ** label -- a string used in error messages 586 ** 587 ** Returns: 588 ** zero in the child 589 ** one in the parent 590 ** 591 ** Side Effects: 592 ** none. 593 */ 594 595 runinchild(label, e) 596 char *label; 597 register ENVELOPE *e; 598 { 599 int childpid; 600 601 if (!OneXact) 602 { 603 childpid = dofork(); 604 if (childpid < 0) 605 { 606 syserr("%s: cannot fork", label); 607 return (1); 608 } 609 if (childpid > 0) 610 { 611 auto int st; 612 613 /* parent -- wait for child to complete */ 614 st = waitfor(childpid); 615 if (st == -1) 616 syserr("%s: lost child", label); 617 618 /* if we exited on a QUIT command, complete the process */ 619 if (st == (EX_QUIT << 8)) 620 finis(); 621 622 return (1); 623 } 624 else 625 { 626 /* child */ 627 InChild = TRUE; 628 QuickAbort = FALSE; 629 clearenvelope(e, FALSE); 630 } 631 } 632 633 /* open alias database */ 634 initaliases(AliasFile, FALSE, e); 635 636 return (0); 637 } 638 639 # endif /* SMTP */ 640