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 5.17 (Berkeley) 01/05/86 (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 5.17 (Berkeley) 01/05/86 (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 s; 304 305 /* 306 ** Set up the address for the mailer. 307 ** Accept "[a.b.c.d]" syntax for host name. 308 */ 309 310 h_errno = 0; 311 errno = 0; 312 313 if (host[0] == '[') 314 { 315 long hid; 316 register char *p = index(host, ']'); 317 318 if (p != NULL) 319 { 320 *p = '\0'; 321 hid = inet_addr(&host[1]); 322 *p = ']'; 323 } 324 if (p == NULL || hid == -1) 325 { 326 usrerr("Invalid numeric domain spec \"%s\"", host); 327 return (EX_NOHOST); 328 } 329 SendmailAddress.sin_addr.s_addr = hid; 330 } 331 else 332 { 333 register struct hostent *hp = gethostbyname(host); 334 335 if (hp == NULL) 336 { 337 if (errno == ETIMEDOUT || h_errno == TRY_AGAIN) 338 { 339 CurEnv->e_flags &= ~EF_FATALERRS; 340 return (EX_TEMPFAIL); 341 } 342 343 /* 344 ** XXX Should look for mail forwarder record here 345 ** XXX if (h_errno == NO_ADDRESS). 346 */ 347 348 return (EX_NOHOST); 349 } 350 bcopy(hp->h_addr, (char *) &SendmailAddress.sin_addr, hp->h_length); 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 # ifdef DEBUG 376 if (tTd(16, 1)) 377 printf("makeconnection (%s)\n", host); 378 # endif DEBUG 379 380 s = socket(AF_INET, SOCK_STREAM, 0); 381 if (s < 0) 382 { 383 syserr("makeconnection: no socket"); 384 goto failure; 385 } 386 387 # ifdef DEBUG 388 if (tTd(16, 1)) 389 printf("makeconnection: %d\n", s); 390 391 /* turn on network debugging? */ 392 if (tTd(16, 14)) 393 { 394 int on = 1; 395 (void) setsockopt(DaemonSocket, SOL_SOCKET, SO_DEBUG, (char *)&on, sizeof on); 396 } 397 # endif DEBUG 398 (void) fflush(CurEnv->e_xfp); /* for debugging */ 399 errno = 0; /* for debugging */ 400 SendmailAddress.sin_family = AF_INET; 401 if (connect(s, &SendmailAddress, sizeof SendmailAddress) < 0) 402 { 403 /* failure, decide if temporary or not */ 404 failure: 405 switch (errno) 406 { 407 case EISCONN: 408 case ETIMEDOUT: 409 case EINPROGRESS: 410 case EALREADY: 411 case EADDRINUSE: 412 case EHOSTDOWN: 413 case ENETDOWN: 414 case ENETRESET: 415 case ENOBUFS: 416 case ECONNREFUSED: 417 case ECONNRESET: 418 case EHOSTUNREACH: 419 case ENETUNREACH: 420 /* there are others, I'm sure..... */ 421 CurEnv->e_flags &= ~EF_FATALERRS; 422 return (EX_TEMPFAIL); 423 424 case EPERM: 425 /* why is this happening? */ 426 syserr("makeconnection: funny failure, addr=%lx, port=%x", 427 SendmailAddress.sin_addr.s_addr, SendmailAddress.sin_port); 428 return (EX_TEMPFAIL); 429 430 default: 431 return (EX_UNAVAILABLE); 432 } 433 } 434 435 /* connection ok, put it into canonical form */ 436 *outfile = fdopen(s, "w"); 437 *infile = fdopen(s, "r"); 438 439 return (EX_OK); 440 } 441 /* 442 ** MYHOSTNAME -- return the name of this host. 443 ** 444 ** Parameters: 445 ** hostbuf -- a place to return the name of this host. 446 ** size -- the size of hostbuf. 447 ** 448 ** Returns: 449 ** A list of aliases for this host. 450 ** 451 ** Side Effects: 452 ** none. 453 */ 454 455 char ** 456 myhostname(hostbuf, size) 457 char hostbuf[]; 458 int size; 459 { 460 extern struct hostent *gethostbyname(); 461 struct hostent *hp; 462 463 if (gethostname(hostbuf, size) < 0) 464 { 465 (void) strcpy(hostbuf, "localhost"); 466 } 467 hp = gethostbyname(hostbuf); 468 if (hp != NULL) 469 { 470 (void) strcpy(hostbuf, hp->h_name); 471 return (hp->h_aliases); 472 } 473 else 474 return (NULL); 475 } 476 /* 477 ** MAPHOSTNAME -- turn a hostname into canonical form 478 ** 479 ** Parameters: 480 ** hbuf -- a buffer containing a hostname. 481 ** hbsize -- the size of hbuf. 482 ** 483 ** Returns: 484 ** none. 485 ** 486 ** Side Effects: 487 ** Looks up the host specified in hbuf. If it is not 488 ** the canonical name for that host, replace it with 489 ** the canonical name. If the name is unknown, or it 490 ** is already the canonical name, leave it unchanged. 491 */ 492 493 maphostname(hbuf, hbsize) 494 char *hbuf; 495 int hbsize; 496 { 497 register struct hostent *hp; 498 extern struct hostent *gethostbyname(); 499 500 /* 501 ** If first character is a bracket, then it is an address 502 ** lookup. Address is copied into a temporary buffer to 503 ** strip the brackets and to preserve hbuf if address is 504 ** unknown. 505 */ 506 507 if (*hbuf == '[') 508 { 509 extern struct hostent *gethostbyaddr(); 510 u_long in_addr; 511 char ptr[256]; 512 char *bptr; 513 514 (void) strcpy(ptr, hbuf); 515 bptr = index(ptr,']'); 516 *bptr = '\0'; 517 in_addr = inet_addr(&ptr[1]); 518 hp = gethostbyaddr((char *) &in_addr, sizeof(struct in_addr), AF_INET); 519 if (hp == NULL) 520 return; 521 } 522 else 523 { 524 makelower(hbuf); 525 hp = gethostbyname(hbuf); 526 } 527 if (hp != NULL) 528 { 529 int i = strlen(hp->h_name); 530 531 if (i >= hbsize) 532 hp->h_name[--i] = '\0'; 533 (void) strcpy(hbuf, hp->h_name); 534 } 535 } 536 537 # else DAEMON 538 /* code for systems without sophisticated networking */ 539 540 /* 541 ** MYHOSTNAME -- stub version for case of no daemon code. 542 ** 543 ** Can't convert to upper case here because might be a UUCP name. 544 ** 545 ** Mark, you can change this to be anything you want...... 546 */ 547 548 char ** 549 myhostname(hostbuf, size) 550 char hostbuf[]; 551 int size; 552 { 553 register FILE *f; 554 555 hostbuf[0] = '\0'; 556 f = fopen("/usr/include/whoami", "r"); 557 if (f != NULL) 558 { 559 (void) fgets(hostbuf, size, f); 560 fixcrlf(hostbuf, TRUE); 561 (void) fclose(f); 562 } 563 return (NULL); 564 } 565 /* 566 ** MAPHOSTNAME -- turn a hostname into canonical form 567 ** 568 ** Parameters: 569 ** hbuf -- a buffer containing a hostname. 570 ** hbsize -- the size of hbuf. 571 ** 572 ** Returns: 573 ** none. 574 ** 575 ** Side Effects: 576 ** Looks up the host specified in hbuf. If it is not 577 ** the canonical name for that host, replace it with 578 ** the canonical name. If the name is unknown, or it 579 ** is already the canonical name, leave it unchanged. 580 */ 581 582 /*ARGSUSED*/ 583 maphostname(hbuf, hbsize) 584 char *hbuf; 585 int hbsize; 586 { 587 return; 588 } 589 590 #endif DAEMON 591