1 /* 2 ** Sendmail 3 ** Copyright (c) 1983 Eric P. Allman 4 ** Berkeley, California 5 ** 6 ** Copyright (c) 1983 Regents of the University of California. 7 ** All rights reserved. The Berkeley software License Agreement 8 ** specifies the terms and conditions for redistribution. 9 */ 10 11 12 # include <errno.h> 13 # include "sendmail.h" 14 15 # ifndef DAEMON 16 # ifndef lint 17 static char SccsId[] = "@(#)daemon.c 5.20 (Berkeley) 06/30/86 (w/o daemon mode)"; 18 # endif not lint 19 # else 20 21 # include <netdb.h> 22 # include <sys/signal.h> 23 # include <sys/wait.h> 24 # include <sys/time.h> 25 # include <sys/resource.h> 26 27 # ifndef lint 28 static char SccsId[] = "@(#)daemon.c 5.20 (Berkeley) 06/30/86 (with daemon mode)"; 29 # endif not lint 30 31 /* 32 ** DAEMON.C -- routines to use when running as a daemon. 33 ** 34 ** This entire file is highly dependent on the 4.2 BSD 35 ** interprocess communication primitives. No attempt has 36 ** been made to make this file portable to Version 7, 37 ** Version 6, MPX files, etc. If you should try such a 38 ** thing yourself, I recommend chucking the entire file 39 ** and starting from scratch. Basic semantics are: 40 ** 41 ** getrequests() 42 ** Opens a port and initiates a connection. 43 ** Returns in a child. Must set InChannel and 44 ** OutChannel appropriately. 45 ** clrdaemon() 46 ** Close any open files associated with getting 47 ** the connection; this is used when running the queue, 48 ** etc., to avoid having extra file descriptors during 49 ** the queue run and to avoid confusing the network 50 ** code (if it cares). 51 ** makeconnection(host, port, outfile, infile) 52 ** Make a connection to the named host on the given 53 ** port. Set *outfile and *infile to the files 54 ** appropriate for communication. Returns zero on 55 ** success, else an exit status describing the 56 ** error. 57 ** maphostname(hbuf, hbufsize) 58 ** Convert the entry in hbuf into a canonical form. It 59 ** may not be larger than hbufsize. 60 */ 61 /* 62 ** GETREQUESTS -- open mail IPC port and get requests. 63 ** 64 ** Parameters: 65 ** none. 66 ** 67 ** Returns: 68 ** none. 69 ** 70 ** Side Effects: 71 ** Waits until some interesting activity occurs. When 72 ** it does, a child is created to process it, and the 73 ** parent waits for completion. Return from this 74 ** routine is always in the child. The file pointers 75 ** "InChannel" and "OutChannel" should be set to point 76 ** to the communication channel. 77 */ 78 79 struct sockaddr_in SendmailAddress;/* internet address of sendmail */ 80 81 int DaemonSocket = -1; /* fd describing socket */ 82 char *NetName; /* name of home (local?) network */ 83 84 getrequests() 85 { 86 int t; 87 register struct servent *sp; 88 int on = 1; 89 extern reapchild(); 90 91 /* 92 ** Set up the address for the mailer. 93 */ 94 95 sp = getservbyname("smtp", "tcp"); 96 if (sp == NULL) 97 { 98 syserr("server \"smtp\" unknown"); 99 goto severe; 100 } 101 SendmailAddress.sin_family = AF_INET; 102 SendmailAddress.sin_addr.s_addr = INADDR_ANY; 103 SendmailAddress.sin_port = sp->s_port; 104 105 /* 106 ** Try to actually open the connection. 107 */ 108 109 # ifdef DEBUG 110 if (tTd(15, 1)) 111 printf("getrequests: port 0x%x\n", SendmailAddress.sin_port); 112 # endif DEBUG 113 114 /* get a socket for the SMTP connection */ 115 DaemonSocket = socket(AF_INET, SOCK_STREAM, 0); 116 if (DaemonSocket < 0) 117 { 118 /* probably another daemon already */ 119 syserr("getrequests: can't create socket"); 120 severe: 121 # ifdef LOG 122 if (LogLevel > 0) 123 syslog(LOG_ALERT, "cannot get connection"); 124 # endif LOG 125 finis(); 126 } 127 128 #ifdef DEBUG 129 /* turn on network debugging? */ 130 if (tTd(15, 15)) 131 (void) setsockopt(DaemonSocket, SOL_SOCKET, SO_DEBUG, (char *)&on, sizeof on); 132 #endif DEBUG 133 134 (void) setsockopt(DaemonSocket, SOL_SOCKET, SO_REUSEADDR, (char *)&on, sizeof on); 135 (void) setsockopt(DaemonSocket, SOL_SOCKET, SO_KEEPALIVE, (char *)&on, sizeof on); 136 137 if (bind(DaemonSocket, &SendmailAddress, sizeof SendmailAddress) < 0) 138 { 139 syserr("getrequests: cannot bind"); 140 (void) close(DaemonSocket); 141 goto severe; 142 } 143 if (listen(DaemonSocket, 10) < 0) 144 { 145 syserr("getrequests: cannot listen"); 146 (void) close(DaemonSocket); 147 goto severe; 148 } 149 150 (void) signal(SIGCHLD, reapchild); 151 152 # ifdef DEBUG 153 if (tTd(15, 1)) 154 printf("getrequests: %d\n", DaemonSocket); 155 # endif DEBUG 156 157 for (;;) 158 { 159 register int pid; 160 auto int lotherend; 161 struct sockaddr_in otherend; 162 extern int RefuseLA; 163 164 /* see if we are rejecting connections */ 165 while (getla() > RefuseLA) 166 sleep(5); 167 168 /* wait for a connection */ 169 do 170 { 171 errno = 0; 172 lotherend = sizeof otherend; 173 t = accept(DaemonSocket, &otherend, &lotherend); 174 } while (t < 0 && errno == EINTR); 175 if (t < 0) 176 { 177 syserr("getrequests: accept"); 178 sleep(5); 179 continue; 180 } 181 182 /* 183 ** Create a subprocess to process the mail. 184 */ 185 186 # ifdef DEBUG 187 if (tTd(15, 2)) 188 printf("getrequests: forking (fd = %d)\n", t); 189 # endif DEBUG 190 191 pid = fork(); 192 if (pid < 0) 193 { 194 syserr("daemon: cannot fork"); 195 sleep(10); 196 (void) close(t); 197 continue; 198 } 199 200 if (pid == 0) 201 { 202 extern struct hostent *gethostbyaddr(); 203 register struct hostent *hp; 204 char buf[MAXNAME]; 205 206 /* 207 ** CHILD -- return to caller. 208 ** Collect verified idea of sending host. 209 ** Verify calling user id if possible here. 210 */ 211 212 (void) signal(SIGCHLD, SIG_DFL); 213 214 /* determine host name */ 215 hp = gethostbyaddr((char *) &otherend.sin_addr, sizeof otherend.sin_addr, AF_INET); 216 if (hp != NULL) 217 { 218 (void) strcpy(buf, hp->h_name); 219 if (NetName != NULL && NetName[0] != '\0' && 220 index(hp->h_name, '.') == NULL) 221 { 222 (void) strcat(buf, "."); 223 (void) strcat(buf, NetName); 224 } 225 } 226 else 227 { 228 extern char *inet_ntoa(); 229 230 /* produce a dotted quad */ 231 (void) sprintf(buf, "[%s]", 232 inet_ntoa(otherend.sin_addr)); 233 } 234 235 /* should we check for illegal connection here? XXX */ 236 237 RealHostName = newstr(buf); 238 239 (void) close(DaemonSocket); 240 InChannel = fdopen(t, "r"); 241 OutChannel = fdopen(dup(t), "w"); 242 # ifdef DEBUG 243 if (tTd(15, 2)) 244 printf("getreq: returning\n"); 245 # endif DEBUG 246 # ifdef LOG 247 if (LogLevel > 11) 248 syslog(LOG_DEBUG, "connected, pid=%d", getpid()); 249 # endif LOG 250 return; 251 } 252 253 /* close the port so that others will hang (for a while) */ 254 (void) close(t); 255 } 256 /*NOTREACHED*/ 257 } 258 /* 259 ** CLRDAEMON -- reset the daemon connection 260 ** 261 ** Parameters: 262 ** none. 263 ** 264 ** Returns: 265 ** none. 266 ** 267 ** Side Effects: 268 ** releases any resources used by the passive daemon. 269 */ 270 271 clrdaemon() 272 { 273 if (DaemonSocket >= 0) 274 (void) close(DaemonSocket); 275 DaemonSocket = -1; 276 } 277 /* 278 ** MAKECONNECTION -- make a connection to an SMTP socket on another machine. 279 ** 280 ** Parameters: 281 ** host -- the name of the host. 282 ** port -- the port number to connect to. 283 ** outfile -- a pointer to a place to put the outfile 284 ** descriptor. 285 ** infile -- ditto for infile. 286 ** 287 ** Returns: 288 ** An exit code telling whether the connection could be 289 ** made and if not why not. 290 ** 291 ** Side Effects: 292 ** none. 293 */ 294 295 int h_errno; /*this will go away when code implemented*/ 296 297 makeconnection(host, port, outfile, infile) 298 char *host; 299 u_short port; 300 FILE **outfile; 301 FILE **infile; 302 { 303 register int i, s; 304 register struct hostent *hp = (struct hostent *)NULL; 305 extern char *inet_ntoa(); 306 int sav_errno; 307 308 /* 309 ** Set up the address for the mailer. 310 ** Accept "[a.b.c.d]" syntax for host name. 311 */ 312 313 h_errno = 0; 314 errno = 0; 315 316 if (host[0] == '[') 317 { 318 long hid; 319 register char *p = index(host, ']'); 320 321 if (p != NULL) 322 { 323 *p = '\0'; 324 hid = inet_addr(&host[1]); 325 *p = ']'; 326 } 327 if (p == NULL || hid == -1) 328 { 329 usrerr("Invalid numeric domain spec \"%s\"", host); 330 return (EX_NOHOST); 331 } 332 SendmailAddress.sin_addr.s_addr = hid; 333 } 334 else 335 { 336 hp = gethostbyname(host); 337 if (hp == NULL) 338 { 339 if (errno == ETIMEDOUT || h_errno == TRY_AGAIN) 340 return (EX_TEMPFAIL); 341 342 /* 343 ** XXX Should look for mail forwarder record here 344 ** XXX if (h_errno == NO_ADDRESS). 345 */ 346 347 return (EX_NOHOST); 348 } 349 bcopy(hp->h_addr, (char *) &SendmailAddress.sin_addr, hp->h_length); 350 i = 1; 351 } 352 353 /* 354 ** Determine the port number. 355 */ 356 357 if (port != 0) 358 SendmailAddress.sin_port = htons(port); 359 else 360 { 361 register struct servent *sp = getservbyname("smtp", "tcp"); 362 363 if (sp == NULL) 364 { 365 syserr("makeconnection: server \"smtp\" unknown"); 366 return (EX_OSFILE); 367 } 368 SendmailAddress.sin_port = sp->s_port; 369 } 370 371 /* 372 ** Try to actually open the connection. 373 */ 374 375 again: 376 # ifdef DEBUG 377 if (tTd(16, 1)) 378 printf("makeconnection (%s [%s])\n", host, 379 inet_ntoa(SendmailAddress.sin_addr.s_addr)); 380 # endif DEBUG 381 382 s = socket(AF_INET, SOCK_STREAM, 0); 383 if (s < 0) 384 { 385 syserr("makeconnection: no socket"); 386 sav_errno = errno; 387 goto failure; 388 } 389 390 # ifdef DEBUG 391 if (tTd(16, 1)) 392 printf("makeconnection: %d\n", s); 393 394 /* turn on network debugging? */ 395 if (tTd(16, 14)) 396 { 397 int on = 1; 398 (void) setsockopt(DaemonSocket, SOL_SOCKET, SO_DEBUG, (char *)&on, sizeof on); 399 } 400 # endif DEBUG 401 (void) fflush(CurEnv->e_xfp); /* for debugging */ 402 errno = 0; /* for debugging */ 403 SendmailAddress.sin_family = AF_INET; 404 if (connect(s, &SendmailAddress, sizeof SendmailAddress) < 0) 405 { 406 sav_errno = errno; 407 (void) close(s); 408 if (hp && hp->h_addr_list[i]) 409 { 410 bcopy(hp->h_addr_list[i++], 411 (char *)&SendmailAddress.sin_addr, hp->h_length); 412 goto again; 413 } 414 415 /* failure, decide if temporary or not */ 416 failure: 417 switch (sav_errno) 418 { 419 case EISCONN: 420 case ETIMEDOUT: 421 case EINPROGRESS: 422 case EALREADY: 423 case EADDRINUSE: 424 case EHOSTDOWN: 425 case ENETDOWN: 426 case ENETRESET: 427 case ENOBUFS: 428 case ECONNREFUSED: 429 case ECONNRESET: 430 case EHOSTUNREACH: 431 case ENETUNREACH: 432 /* there are others, I'm sure..... */ 433 return (EX_TEMPFAIL); 434 435 case EPERM: 436 /* why is this happening? */ 437 syserr("makeconnection: funny failure, addr=%lx, port=%x", 438 SendmailAddress.sin_addr.s_addr, SendmailAddress.sin_port); 439 return (EX_TEMPFAIL); 440 441 default: 442 return (EX_UNAVAILABLE); 443 } 444 } 445 446 /* connection ok, put it into canonical form */ 447 *outfile = fdopen(s, "w"); 448 *infile = fdopen(s, "r"); 449 450 return (EX_OK); 451 } 452 /* 453 ** MYHOSTNAME -- return the name of this host. 454 ** 455 ** Parameters: 456 ** hostbuf -- a place to return the name of this host. 457 ** size -- the size of hostbuf. 458 ** 459 ** Returns: 460 ** A list of aliases for this host. 461 ** 462 ** Side Effects: 463 ** none. 464 */ 465 466 char ** 467 myhostname(hostbuf, size) 468 char hostbuf[]; 469 int size; 470 { 471 extern struct hostent *gethostbyname(); 472 struct hostent *hp; 473 474 if (gethostname(hostbuf, size) < 0) 475 { 476 (void) strcpy(hostbuf, "localhost"); 477 } 478 hp = gethostbyname(hostbuf); 479 if (hp != NULL) 480 { 481 (void) strcpy(hostbuf, hp->h_name); 482 return (hp->h_aliases); 483 } 484 else 485 return (NULL); 486 } 487 /* 488 ** MAPHOSTNAME -- turn a hostname into canonical form 489 ** 490 ** Parameters: 491 ** hbuf -- a buffer containing a hostname. 492 ** hbsize -- the size of hbuf. 493 ** 494 ** Returns: 495 ** none. 496 ** 497 ** Side Effects: 498 ** Looks up the host specified in hbuf. If it is not 499 ** the canonical name for that host, replace it with 500 ** the canonical name. If the name is unknown, or it 501 ** is already the canonical name, leave it unchanged. 502 */ 503 504 maphostname(hbuf, hbsize) 505 char *hbuf; 506 int hbsize; 507 { 508 register struct hostent *hp; 509 extern struct hostent *gethostbyname(); 510 511 /* 512 ** If first character is a bracket, then it is an address 513 ** lookup. Address is copied into a temporary buffer to 514 ** strip the brackets and to preserve hbuf if address is 515 ** unknown. 516 */ 517 518 if (*hbuf == '[') 519 { 520 extern struct hostent *gethostbyaddr(); 521 u_long in_addr; 522 char ptr[256]; 523 char *bptr; 524 525 (void) strcpy(ptr, hbuf); 526 bptr = index(ptr,']'); 527 *bptr = '\0'; 528 in_addr = inet_addr(&ptr[1]); 529 hp = gethostbyaddr((char *) &in_addr, sizeof(struct in_addr), AF_INET); 530 if (hp == NULL) 531 return; 532 } 533 else 534 { 535 makelower(hbuf); 536 hp = gethostbyname(hbuf); 537 } 538 if (hp != NULL) 539 { 540 int i = strlen(hp->h_name); 541 542 if (i >= hbsize) 543 hp->h_name[--i] = '\0'; 544 (void) strcpy(hbuf, hp->h_name); 545 } 546 } 547 548 # else DAEMON 549 /* code for systems without sophisticated networking */ 550 551 /* 552 ** MYHOSTNAME -- stub version for case of no daemon code. 553 ** 554 ** Can't convert to upper case here because might be a UUCP name. 555 ** 556 ** Mark, you can change this to be anything you want...... 557 */ 558 559 char ** 560 myhostname(hostbuf, size) 561 char hostbuf[]; 562 int size; 563 { 564 register FILE *f; 565 566 hostbuf[0] = '\0'; 567 f = fopen("/usr/include/whoami", "r"); 568 if (f != NULL) 569 { 570 (void) fgets(hostbuf, size, f); 571 fixcrlf(hostbuf, TRUE); 572 (void) fclose(f); 573 } 574 return (NULL); 575 } 576 /* 577 ** MAPHOSTNAME -- turn a hostname into canonical form 578 ** 579 ** Parameters: 580 ** hbuf -- a buffer containing a hostname. 581 ** hbsize -- the size of hbuf. 582 ** 583 ** Returns: 584 ** none. 585 ** 586 ** Side Effects: 587 ** Looks up the host specified in hbuf. If it is not 588 ** the canonical name for that host, replace it with 589 ** the canonical name. If the name is unknown, or it 590 ** is already the canonical name, leave it unchanged. 591 */ 592 593 /*ARGSUSED*/ 594 maphostname(hbuf, hbsize) 595 char *hbuf; 596 int hbsize; 597 { 598 return; 599 } 600 601 #endif DAEMON 602