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 5.34 (Berkeley) 04/16/92 (with SMTP)"; 14 #else 15 static char sccsid[] = "@(#)srvrsmtp.c 5.34 (Berkeley) 04/16/92 (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() 90 { 91 register char *p; 92 register struct cmd *c; 93 char *cmd; 94 static char *skipword(); 95 bool hasmail; /* mail command received */ 96 auto ADDRESS *vrfyqueue; 97 ADDRESS *a; 98 char *sendinghost; 99 char inp[MAXLINE]; 100 char cmdbuf[100]; 101 extern char Version[]; 102 extern char *macvalue(); 103 extern ADDRESS *recipient(); 104 extern ENVELOPE BlankEnvelope; 105 extern ENVELOPE *newenvelope(); 106 107 hasmail = FALSE; 108 if (OutChannel != stdout) 109 { 110 /* arrange for debugging output to go to remote host */ 111 (void) close(1); 112 (void) dup(fileno(OutChannel)); 113 } 114 settime(); 115 if (RealHostName != NULL) 116 { 117 CurHostName = RealHostName; 118 setproctitle("srvrsmtp %s", CurHostName); 119 } 120 else 121 { 122 /* this must be us!! */ 123 CurHostName = MyHostName; 124 } 125 expand("\001e", inp, &inp[sizeof inp], CurEnv); 126 message("220", inp); 127 SmtpPhase = "startup"; 128 sendinghost = NULL; 129 for (;;) 130 { 131 /* arrange for backout */ 132 if (setjmp(TopFrame) > 0 && InChild) 133 finis(); 134 QuickAbort = FALSE; 135 HoldErrs = FALSE; 136 LogUsrErrs = FALSE; 137 138 /* setup for the read */ 139 CurEnv->e_to = NULL; 140 Errors = 0; 141 (void) fflush(stdout); 142 143 /* read the input line */ 144 p = sfgets(inp, sizeof inp, InChannel); 145 146 /* handle errors */ 147 if (p == NULL) 148 { 149 /* end of file, just die */ 150 message("421", "%s Lost input channel from %s", 151 MyHostName, CurHostName); 152 finis(); 153 } 154 155 /* clean up end of line */ 156 fixcrlf(inp, TRUE); 157 158 /* echo command to transcript */ 159 if (CurEnv->e_xfp != NULL) 160 fprintf(CurEnv->e_xfp, "<<< %s\n", inp); 161 162 /* break off command */ 163 for (p = inp; isspace(*p); p++) 164 continue; 165 cmd = p; 166 for (cmd = cmdbuf; *p != '\0' && !isspace(*p); ) 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', CurEnv) == 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") > 0) 235 break; 236 define('s', sendinghost, CurEnv); 237 define('r', "SMTP", CurEnv); 238 initsys(); 239 setproctitle("%s %s: %s", CurEnv->e_id, 240 CurHostName, inp); 241 242 /* child -- go do the processing */ 243 p = skipword(p, "from"); 244 if (p == NULL) 245 break; 246 setsender(p, CurEnv); 247 if (Errors == 0) 248 { 249 message("250", "Sender ok"); 250 hasmail = TRUE; 251 } 252 else if (InChild) 253 finis(); 254 break; 255 256 case CMDRCPT: /* rcpt -- designate recipient */ 257 SmtpPhase = "RCPT"; 258 setproctitle("%s %s: %s", CurEnv->e_id, 259 CurHostName, inp); 260 if (setjmp(TopFrame) > 0) 261 { 262 CurEnv->e_flags &= ~EF_FATALERRS; 263 break; 264 } 265 QuickAbort = TRUE; 266 LogUsrErrs = TRUE; 267 p = skipword(p, "to"); 268 if (p == NULL) 269 break; 270 a = parseaddr(p, (ADDRESS *) NULL, 1, '\0'); 271 if (a == NULL) 272 break; 273 a->q_flags |= QPRIMARY; 274 a = recipient(a, &CurEnv->e_sendqueue); 275 if (Errors != 0) 276 break; 277 278 /* no errors during parsing, but might be a duplicate */ 279 CurEnv->e_to = p; 280 if (!bitset(QBADADDR, a->q_flags)) 281 message("250", "Recipient ok"); 282 else 283 { 284 /* punt -- should keep message in ADDRESS.... */ 285 message("550", "Addressee unknown"); 286 } 287 CurEnv->e_to = NULL; 288 break; 289 290 case CMDDATA: /* data -- text of mail */ 291 SmtpPhase = "DATA"; 292 if (!hasmail) 293 { 294 message("503", "Need MAIL command"); 295 break; 296 } 297 else if (CurEnv->e_nrcpts <= 0) 298 { 299 message("503", "Need RCPT (recipient)"); 300 break; 301 } 302 303 /* collect the text of the message */ 304 SmtpPhase = "collect"; 305 setproctitle("%s %s: %s", CurEnv->e_id, 306 CurHostName, inp); 307 collect(TRUE); 308 if (Errors != 0) 309 break; 310 311 /* 312 ** Arrange to send to everyone. 313 ** If sending to multiple people, mail back 314 ** errors rather than reporting directly. 315 ** In any case, don't mail back errors for 316 ** anything that has happened up to 317 ** now (the other end will do this). 318 ** Truncate our transcript -- the mail has gotten 319 ** to us successfully, and if we have 320 ** to mail this back, it will be easier 321 ** on the reader. 322 ** Then send to everyone. 323 ** Finally give a reply code. If an error has 324 ** already been given, don't mail a 325 ** message back. 326 ** We goose error returns by clearing error bit. 327 */ 328 329 SmtpPhase = "delivery"; 330 if (CurEnv->e_nrcpts != 1) 331 { 332 HoldErrs = TRUE; 333 ErrorMode = EM_MAIL; 334 } 335 CurEnv->e_flags &= ~EF_FATALERRS; 336 CurEnv->e_xfp = freopen(queuename(CurEnv, 'x'), "w", CurEnv->e_xfp); 337 338 /* send to all recipients */ 339 sendall(CurEnv, SM_DEFAULT); 340 CurEnv->e_to = NULL; 341 342 /* save statistics */ 343 markstats(CurEnv, (ADDRESS *) NULL); 344 345 /* issue success if appropriate and reset */ 346 if (Errors == 0 || HoldErrs) 347 message("250", "Ok"); 348 else 349 CurEnv->e_flags &= ~EF_FATALERRS; 350 351 /* if in a child, pop back to our parent */ 352 if (InChild) 353 finis(); 354 355 /* clean up a bit */ 356 hasmail = 0; 357 dropenvelope(CurEnv); 358 CurEnv = newenvelope(CurEnv); 359 CurEnv->e_flags = BlankEnvelope.e_flags; 360 break; 361 362 case CMDRSET: /* rset -- reset state */ 363 message("250", "Reset state"); 364 if (InChild) 365 finis(); 366 break; 367 368 case CMDVRFY: /* vrfy -- verify address */ 369 if (runinchild("SMTP-VRFY") > 0) 370 break; 371 setproctitle("%s: %s", CurHostName, inp); 372 vrfyqueue = NULL; 373 QuickAbort = TRUE; 374 sendtolist(p, (ADDRESS *) NULL, &vrfyqueue); 375 if (Errors != 0) 376 { 377 if (InChild) 378 finis(); 379 break; 380 } 381 while (vrfyqueue != NULL) 382 { 383 register ADDRESS *a = vrfyqueue->q_next; 384 char *code; 385 386 while (a != NULL && bitset(QDONTSEND|QBADADDR, a->q_flags)) 387 a = a->q_next; 388 389 if (!bitset(QDONTSEND|QBADADDR, vrfyqueue->q_flags)) 390 { 391 if (a != NULL) 392 code = "250-"; 393 else 394 code = "250"; 395 if (vrfyqueue->q_fullname == NULL) 396 message(code, "<%s>", vrfyqueue->q_paddr); 397 else 398 message(code, "%s <%s>", 399 vrfyqueue->q_fullname, vrfyqueue->q_paddr); 400 } 401 else if (a == NULL) 402 message("554", "Self destructive alias loop"); 403 vrfyqueue = a; 404 } 405 if (InChild) 406 finis(); 407 break; 408 409 case CMDHELP: /* help -- give user info */ 410 help(p); 411 break; 412 413 case CMDNOOP: /* noop -- do nothing */ 414 message("200", "OK"); 415 break; 416 417 case CMDQUIT: /* quit -- leave mail */ 418 message("221", "%s closing connection", MyHostName); 419 if (InChild) 420 ExitStat = EX_QUIT; 421 finis(); 422 423 case CMDVERB: /* set verbose mode */ 424 Verbose = TRUE; 425 SendMode = SM_DELIVER; 426 message("200", "Verbose mode"); 427 break; 428 429 case CMDONEX: /* doing one transaction only */ 430 OneXact = TRUE; 431 message("200", "Only one transaction"); 432 break; 433 434 # ifdef SMTPDEBUG 435 case CMDDBGQSHOW: /* show queues */ 436 printf("Send Queue="); 437 printaddr(CurEnv->e_sendqueue, TRUE); 438 break; 439 440 case CMDDBGDEBUG: /* set debug mode */ 441 tTsetup(tTdvect, sizeof tTdvect, "0-99.1"); 442 tTflag(p); 443 message("200", "Debug set"); 444 break; 445 446 # else /* not SMTPDEBUG */ 447 448 case CMDDBGQSHOW: /* show queues */ 449 case CMDDBGDEBUG: /* set debug mode */ 450 # ifdef LOG 451 if (RealHostName != NULL && LogLevel > 0) 452 syslog(LOG_NOTICE, 453 "\"%s\" command from %s (%s)\n", 454 c->cmdname, RealHostName, 455 inet_ntoa(RealHostAddr.sin_addr)); 456 # endif 457 /* FALL THROUGH */ 458 # endif /* SMTPDEBUG */ 459 460 case CMDERROR: /* unknown command */ 461 message("500", "Command unrecognized"); 462 break; 463 464 default: 465 errno = 0; 466 syserr("smtp: unknown code %d", c->cmdcode); 467 break; 468 } 469 } 470 } 471 /* 472 ** SKIPWORD -- skip a fixed word. 473 ** 474 ** Parameters: 475 ** p -- place to start looking. 476 ** w -- word to skip. 477 ** 478 ** Returns: 479 ** p following w. 480 ** NULL on error. 481 ** 482 ** Side Effects: 483 ** clobbers the p data area. 484 */ 485 486 static char * 487 skipword(p, w) 488 register char *p; 489 char *w; 490 { 491 register char *q; 492 493 /* find beginning of word */ 494 while (isspace(*p)) 495 p++; 496 q = p; 497 498 /* find end of word */ 499 while (*p != '\0' && *p != ':' && !isspace(*p)) 500 p++; 501 while (isspace(*p)) 502 *p++ = '\0'; 503 if (*p != ':') 504 { 505 syntax: 506 message("501", "Syntax error"); 507 Errors++; 508 return (NULL); 509 } 510 *p++ = '\0'; 511 while (isspace(*p)) 512 p++; 513 514 /* see if the input word matches desired word */ 515 if (strcasecmp(q, w)) 516 goto syntax; 517 518 return (p); 519 } 520 /* 521 ** HELP -- implement the HELP command. 522 ** 523 ** Parameters: 524 ** topic -- the topic we want help for. 525 ** 526 ** Returns: 527 ** none. 528 ** 529 ** Side Effects: 530 ** outputs the help file to message output. 531 */ 532 533 help(topic) 534 char *topic; 535 { 536 register FILE *hf; 537 int len; 538 char buf[MAXLINE]; 539 bool noinfo; 540 541 if (HelpFile == NULL || (hf = fopen(HelpFile, "r")) == NULL) 542 { 543 /* no help */ 544 errno = 0; 545 message("502", "HELP not implemented"); 546 return; 547 } 548 549 if (topic == NULL || *topic == '\0') 550 topic = "smtp"; 551 else 552 makelower(topic); 553 554 len = strlen(topic); 555 noinfo = TRUE; 556 557 while (fgets(buf, sizeof buf, hf) != NULL) 558 { 559 if (strncmp(buf, topic, len) == 0) 560 { 561 register char *p; 562 563 p = index(buf, '\t'); 564 if (p == NULL) 565 p = buf; 566 else 567 p++; 568 fixcrlf(p, TRUE); 569 message("214-", p); 570 noinfo = FALSE; 571 } 572 } 573 574 if (noinfo) 575 message("504", "HELP topic unknown"); 576 else 577 message("214", "End of HELP info"); 578 (void) fclose(hf); 579 } 580 /* 581 ** RUNINCHILD -- return twice -- once in the child, then in the parent again 582 ** 583 ** Parameters: 584 ** label -- a string used in error messages 585 ** 586 ** Returns: 587 ** zero in the child 588 ** one in the parent 589 ** 590 ** Side Effects: 591 ** none. 592 */ 593 594 runinchild(label) 595 char *label; 596 { 597 int childpid; 598 599 if (!OneXact) 600 { 601 childpid = dofork(); 602 if (childpid < 0) 603 { 604 syserr("%s: cannot fork", label); 605 return (1); 606 } 607 if (childpid > 0) 608 { 609 auto int st; 610 611 /* parent -- wait for child to complete */ 612 st = waitfor(childpid); 613 if (st == -1) 614 syserr("%s: lost child", label); 615 616 /* if we exited on a QUIT command, complete the process */ 617 if (st == (EX_QUIT << 8)) 618 finis(); 619 620 return (1); 621 } 622 else 623 { 624 /* child */ 625 InChild = TRUE; 626 QuickAbort = FALSE; 627 clearenvelope(CurEnv, FALSE); 628 } 629 } 630 631 /* open alias database */ 632 initaliases(AliasFile, FALSE); 633 634 return (0); 635 } 636 637 # endif SMTP 638