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 <errno.h> 10 #include "sendmail.h" 11 12 #ifndef lint 13 #ifdef DAEMON 14 static char sccsid[] = "@(#)daemon.c 5.41 (Berkeley) 12/17/91 (with daemon mode)"; 15 #else 16 static char sccsid[] = "@(#)daemon.c 5.41 (Berkeley) 12/17/91 (without daemon mode)"; 17 #endif 18 #endif /* not lint */ 19 20 #ifdef DAEMON 21 22 # include <netdb.h> 23 # include <sys/signal.h> 24 # include <sys/wait.h> 25 # include <sys/time.h> 26 # include <sys/resource.h> 27 28 /* 29 ** DAEMON.C -- routines to use when running as a daemon. 30 ** 31 ** This entire file is highly dependent on the 4.2 BSD 32 ** interprocess communication primitives. No attempt has 33 ** been made to make this file portable to Version 7, 34 ** Version 6, MPX files, etc. If you should try such a 35 ** thing yourself, I recommend chucking the entire file 36 ** and starting from scratch. Basic semantics are: 37 ** 38 ** getrequests() 39 ** Opens a port and initiates a connection. 40 ** Returns in a child. Must set InChannel and 41 ** OutChannel appropriately. 42 ** clrdaemon() 43 ** Close any open files associated with getting 44 ** the connection; this is used when running the queue, 45 ** etc., to avoid having extra file descriptors during 46 ** the queue run and to avoid confusing the network 47 ** code (if it cares). 48 ** makeconnection(host, port, outfile, infile) 49 ** Make a connection to the named host on the given 50 ** port. Set *outfile and *infile to the files 51 ** appropriate for communication. Returns zero on 52 ** success, else an exit status describing the 53 ** error. 54 ** maphostname(hbuf, hbufsize) 55 ** Convert the entry in hbuf into a canonical form. It 56 ** may not be larger than hbufsize. 57 */ 58 /* 59 ** GETREQUESTS -- open mail IPC port and get requests. 60 ** 61 ** Parameters: 62 ** none. 63 ** 64 ** Returns: 65 ** none. 66 ** 67 ** Side Effects: 68 ** Waits until some interesting activity occurs. When 69 ** it does, a child is created to process it, and the 70 ** parent waits for completion. Return from this 71 ** routine is always in the child. The file pointers 72 ** "InChannel" and "OutChannel" should be set to point 73 ** to the communication channel. 74 */ 75 76 struct sockaddr_in SendmailAddress;/* internet address of sendmail */ 77 78 int DaemonSocket = -1; /* fd describing socket */ 79 char *NetName; /* name of home (local?) network */ 80 81 getrequests() 82 { 83 int t; 84 register struct servent *sp; 85 int on = 1; 86 extern void reapchild(); 87 88 /* 89 ** Set up the address for the mailer. 90 */ 91 92 sp = getservbyname("smtp", "tcp"); 93 if (sp == NULL) 94 { 95 syserr("server \"smtp\" unknown"); 96 goto severe; 97 } 98 SendmailAddress.sin_family = AF_INET; 99 SendmailAddress.sin_addr.s_addr = INADDR_ANY; 100 SendmailAddress.sin_port = sp->s_port; 101 102 /* 103 ** Try to actually open the connection. 104 */ 105 106 if (tTd(15, 1)) 107 printf("getrequests: port 0x%x\n", SendmailAddress.sin_port); 108 109 /* get a socket for the SMTP connection */ 110 DaemonSocket = socket(AF_INET, SOCK_STREAM, 0); 111 if (DaemonSocket < 0) 112 { 113 /* probably another daemon already */ 114 syserr("getrequests: can't create socket"); 115 severe: 116 # ifdef LOG 117 if (LogLevel > 0) 118 syslog(LOG_ALERT, "cannot get connection"); 119 # endif LOG 120 finis(); 121 } 122 123 /* turn on network debugging? */ 124 if (tTd(15, 15)) 125 (void) setsockopt(DaemonSocket, SOL_SOCKET, SO_DEBUG, (char *)&on, sizeof on); 126 127 (void) setsockopt(DaemonSocket, SOL_SOCKET, SO_REUSEADDR, (char *)&on, sizeof on); 128 (void) setsockopt(DaemonSocket, SOL_SOCKET, SO_KEEPALIVE, (char *)&on, sizeof on); 129 130 if (bind(DaemonSocket, 131 (struct sockaddr *)&SendmailAddress, sizeof SendmailAddress) < 0) 132 { 133 syserr("getrequests: cannot bind"); 134 (void) close(DaemonSocket); 135 goto severe; 136 } 137 if (listen(DaemonSocket, 10) < 0) 138 { 139 syserr("getrequests: cannot listen"); 140 (void) close(DaemonSocket); 141 goto severe; 142 } 143 144 (void) signal(SIGCHLD, reapchild); 145 146 if (tTd(15, 1)) 147 printf("getrequests: %d\n", DaemonSocket); 148 149 for (;;) 150 { 151 register int pid; 152 auto int lotherend; 153 154 /* see if we are rejecting connections */ 155 while ((CurrentLA = getla()) > RefuseLA) 156 { 157 setproctitle("rejecting connections: load average: %.2f", (double)CurrentLA); 158 sleep(5); 159 } 160 161 /* wait for a connection */ 162 setproctitle("accepting connections"); 163 do 164 { 165 errno = 0; 166 lotherend = sizeof RealHostAddr; 167 t = accept(DaemonSocket, 168 (struct sockaddr *)&RealHostAddr, &lotherend); 169 } while (t < 0 && errno == EINTR); 170 if (t < 0) 171 { 172 syserr("getrequests: accept"); 173 sleep(5); 174 continue; 175 } 176 177 /* 178 ** Create a subprocess to process the mail. 179 */ 180 181 if (tTd(15, 2)) 182 printf("getrequests: forking (fd = %d)\n", t); 183 184 pid = fork(); 185 if (pid < 0) 186 { 187 syserr("daemon: cannot fork"); 188 sleep(10); 189 (void) close(t); 190 continue; 191 } 192 193 if (pid == 0) 194 { 195 extern struct hostent *gethostbyaddr(); 196 register struct hostent *hp; 197 char buf[MAXNAME]; 198 199 /* 200 ** CHILD -- return to caller. 201 ** Collect verified idea of sending host. 202 ** Verify calling user id if possible here. 203 */ 204 205 (void) signal(SIGCHLD, SIG_DFL); 206 207 /* determine host name */ 208 hp = gethostbyaddr((char *) &RealHostAddr.sin_addr, sizeof RealHostAddr.sin_addr, AF_INET); 209 if (hp != NULL) 210 (void) strcpy(buf, hp->h_name); 211 else 212 { 213 extern char *inet_ntoa(); 214 215 /* produce a dotted quad */ 216 (void) sprintf(buf, "[%s]", 217 inet_ntoa(RealHostAddr.sin_addr)); 218 } 219 220 /* should we check for illegal connection here? XXX */ 221 222 RealHostName = newstr(buf); 223 224 (void) close(DaemonSocket); 225 InChannel = fdopen(t, "r"); 226 OutChannel = fdopen(dup(t), "w"); 227 if (tTd(15, 2)) 228 printf("getreq: returning\n"); 229 # ifdef LOG 230 if (LogLevel > 11) 231 syslog(LOG_DEBUG, "connected, pid=%d", getpid()); 232 # endif LOG 233 return; 234 } 235 236 /* close the port so that others will hang (for a while) */ 237 (void) close(t); 238 } 239 /*NOTREACHED*/ 240 } 241 /* 242 ** CLRDAEMON -- reset the daemon connection 243 ** 244 ** Parameters: 245 ** none. 246 ** 247 ** Returns: 248 ** none. 249 ** 250 ** Side Effects: 251 ** releases any resources used by the passive daemon. 252 */ 253 254 clrdaemon() 255 { 256 if (DaemonSocket >= 0) 257 (void) close(DaemonSocket); 258 DaemonSocket = -1; 259 } 260 /* 261 ** MAKECONNECTION -- make a connection to an SMTP socket on another machine. 262 ** 263 ** Parameters: 264 ** host -- the name of the host. 265 ** port -- the port number to connect to. 266 ** outfile -- a pointer to a place to put the outfile 267 ** descriptor. 268 ** infile -- ditto for infile. 269 ** 270 ** Returns: 271 ** An exit code telling whether the connection could be 272 ** made and if not why not. 273 ** 274 ** Side Effects: 275 ** none. 276 */ 277 278 makeconnection(host, port, outfile, infile) 279 char *host; 280 u_short port; 281 FILE **outfile; 282 FILE **infile; 283 { 284 register int i, s; 285 register struct hostent *hp = (struct hostent *)NULL; 286 extern char *inet_ntoa(); 287 int sav_errno; 288 #ifdef NAMED_BIND 289 extern int h_errno; 290 #endif 291 292 /* 293 ** Set up the address for the mailer. 294 ** Accept "[a.b.c.d]" syntax for host name. 295 */ 296 297 #ifdef NAMED_BIND 298 h_errno = 0; 299 #endif 300 errno = 0; 301 302 if (host[0] == '[') 303 { 304 long hid; 305 register char *p = index(host, ']'); 306 307 if (p != NULL) 308 { 309 *p = '\0'; 310 hid = inet_addr(&host[1]); 311 *p = ']'; 312 } 313 if (p == NULL || hid == -1) 314 { 315 usrerr("Invalid numeric domain spec \"%s\"", host); 316 return (EX_NOHOST); 317 } 318 SendmailAddress.sin_addr.s_addr = hid; 319 } 320 else 321 { 322 hp = gethostbyname(host); 323 if (hp == NULL) 324 { 325 #ifdef NAMED_BIND 326 if (errno == ETIMEDOUT || h_errno == TRY_AGAIN) 327 return (EX_TEMPFAIL); 328 329 /* if name server is specified, assume temp fail */ 330 if (errno == ECONNREFUSED && UseNameServer) 331 return (EX_TEMPFAIL); 332 #endif 333 334 /* 335 ** XXX Should look for mail forwarder record here 336 ** XXX if (h_errno == NO_ADDRESS). 337 */ 338 339 return (EX_NOHOST); 340 } 341 bcopy(hp->h_addr, (char *) &SendmailAddress.sin_addr, hp->h_length); 342 i = 1; 343 } 344 345 /* 346 ** Determine the port number. 347 */ 348 349 if (port != 0) 350 SendmailAddress.sin_port = htons(port); 351 else 352 { 353 register struct servent *sp = getservbyname("smtp", "tcp"); 354 355 if (sp == NULL) 356 { 357 syserr("makeconnection: server \"smtp\" unknown"); 358 return (EX_OSFILE); 359 } 360 SendmailAddress.sin_port = sp->s_port; 361 } 362 363 /* 364 ** Try to actually open the connection. 365 */ 366 367 again: 368 if (tTd(16, 1)) 369 printf("makeconnection (%s [%s])\n", host, 370 inet_ntoa(SendmailAddress.sin_addr)); 371 372 s = socket(AF_INET, SOCK_STREAM, 0); 373 if (s < 0) 374 { 375 syserr("makeconnection: no socket"); 376 sav_errno = errno; 377 goto failure; 378 } 379 380 if (tTd(16, 1)) 381 printf("makeconnection: %d\n", s); 382 383 /* turn on network debugging? */ 384 if (tTd(16, 14)) 385 { 386 int on = 1; 387 (void) setsockopt(DaemonSocket, SOL_SOCKET, SO_DEBUG, (char *)&on, sizeof on); 388 } 389 if (CurEnv->e_xfp != NULL) 390 (void) fflush(CurEnv->e_xfp); /* for debugging */ 391 errno = 0; /* for debugging */ 392 SendmailAddress.sin_family = AF_INET; 393 if (connect(s, 394 (struct sockaddr *)&SendmailAddress, sizeof SendmailAddress) < 0) 395 { 396 sav_errno = errno; 397 (void) close(s); 398 if (hp && hp->h_addr_list[i]) 399 { 400 bcopy(hp->h_addr_list[i++], 401 (char *)&SendmailAddress.sin_addr, hp->h_length); 402 goto again; 403 } 404 405 /* failure, decide if temporary or not */ 406 failure: 407 switch (sav_errno) 408 { 409 case EISCONN: 410 case ETIMEDOUT: 411 case EINPROGRESS: 412 case EALREADY: 413 case EADDRINUSE: 414 case EHOSTDOWN: 415 case ENETDOWN: 416 case ENETRESET: 417 case ENOBUFS: 418 case ECONNREFUSED: 419 case ECONNRESET: 420 case EHOSTUNREACH: 421 case ENETUNREACH: 422 #ifdef ENOSR 423 case ENOSR: 424 #endif 425 /* there are others, I'm sure..... */ 426 return (EX_TEMPFAIL); 427 428 case EPERM: 429 /* why is this happening? */ 430 syserr("makeconnection: funny failure, addr=%lx, port=%x", 431 SendmailAddress.sin_addr.s_addr, SendmailAddress.sin_port); 432 return (EX_TEMPFAIL); 433 434 default: 435 { 436 extern char *errstring(); 437 438 message(Arpa_Info, "%s", errstring(sav_errno)); 439 return (EX_UNAVAILABLE); 440 } 441 } 442 } 443 444 /* connection ok, put it into canonical form */ 445 *outfile = fdopen(s, "w"); 446 *infile = fdopen(dup(s), "r"); 447 448 return (EX_OK); 449 } 450 /* 451 ** MYHOSTNAME -- return the name of this host. 452 ** 453 ** Parameters: 454 ** hostbuf -- a place to return the name of this host. 455 ** size -- the size of hostbuf. 456 ** 457 ** Returns: 458 ** A list of aliases for this host. 459 ** 460 ** Side Effects: 461 ** none. 462 */ 463 464 char ** 465 myhostname(hostbuf, size) 466 char hostbuf[]; 467 int size; 468 { 469 extern struct hostent *gethostbyname(); 470 struct hostent *hp; 471 472 if (gethostname(hostbuf, size) < 0) 473 { 474 (void) strcpy(hostbuf, "localhost"); 475 } 476 hp = gethostbyname(hostbuf); 477 if (hp != NULL) 478 { 479 (void) strcpy(hostbuf, hp->h_name); 480 return (hp->h_aliases); 481 } 482 else 483 return (NULL); 484 } 485 /* 486 * MAPHOSTNAME -- turn a hostname into canonical form 487 * 488 * Parameters: 489 * hbuf -- a buffer containing a hostname. 490 * hbsize -- the size of hbuf. 491 * 492 * Returns: 493 * TRUE if the host name was mapped. 494 * FALSE otherwise. 495 * 496 * Side Effects: 497 * Looks up the host specified in hbuf. If it is not 498 * the canonical name for that host, replace it with 499 * the canonical name. If the name is unknown, or it 500 * is already the canonical name, leave it unchanged. 501 */ 502 503 bool 504 maphostname(hbuf, hbsize) 505 char *hbuf; 506 int hbsize; 507 { 508 register struct hostent *hp; 509 u_long in_addr; 510 char ptr[256], *cp; 511 struct hostent *gethostbyaddr(); 512 513 /* 514 * If first character is a bracket, then it is an address 515 * lookup. Address is copied into a temporary buffer to 516 * strip the brackets and to preserve hbuf if address is 517 * unknown. 518 */ 519 if (*hbuf != '[') 520 return (getcanonname(hbuf, hbsize)); 521 if ((cp = index(strcpy(ptr, hbuf), ']')) == NULL) 522 return (FALSE); 523 *cp = '\0'; 524 in_addr = inet_addr(&ptr[1]); 525 hp = gethostbyaddr((char *)&in_addr, sizeof(struct in_addr), AF_INET); 526 if (hp == NULL) 527 return (FALSE); 528 if (strlen(hp->h_name) >= hbsize) 529 hp->h_name[hbsize - 1] = '\0'; 530 (void)strcpy(hbuf, hp->h_name); 531 return (TRUE); 532 } 533 534 # else DAEMON 535 /* code for systems without sophisticated networking */ 536 537 /* 538 ** MYHOSTNAME -- stub version for case of no daemon code. 539 ** 540 ** Can't convert to upper case here because might be a UUCP name. 541 ** 542 ** Mark, you can change this to be anything you want...... 543 */ 544 545 char ** 546 myhostname(hostbuf, size) 547 char hostbuf[]; 548 int size; 549 { 550 register FILE *f; 551 552 hostbuf[0] = '\0'; 553 f = fopen("/usr/include/whoami", "r"); 554 if (f != NULL) 555 { 556 (void) fgets(hostbuf, size, f); 557 fixcrlf(hostbuf, TRUE); 558 (void) fclose(f); 559 } 560 return (NULL); 561 } 562 /* 563 ** MAPHOSTNAME -- turn a hostname into canonical form 564 ** 565 ** Parameters: 566 ** hbuf -- a buffer containing a hostname. 567 ** hbsize -- the size of hbuf. 568 ** 569 ** Returns: 570 ** TRUE if the hostname was mapped. 571 ** FALSE otherwise. 572 ** 573 ** Side Effects: 574 ** Looks up the host specified in hbuf. If it is not 575 ** the canonical name for that host, replace it with 576 ** the canonical name. If the name is unknown, or it 577 ** is already the canonical name, leave it unchanged. 578 */ 579 580 /*ARGSUSED*/ 581 bool 582 maphostname(hbuf, hbsize) 583 char *hbuf; 584 int hbsize; 585 { 586 return (FALSE); 587 } 588 589 #endif DAEMON 590