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 5.9 (Berkeley) 09/19/85 (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 5.9 (Berkeley) 09/19/85 (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 ** 58 ** The semantics of both of these should be clean. 59 */ 60 /* 61 ** GETREQUESTS -- open mail IPC port and get requests. 62 ** 63 ** Parameters: 64 ** none. 65 ** 66 ** Returns: 67 ** none. 68 ** 69 ** Side Effects: 70 ** Waits until some interesting activity occurs. When 71 ** it does, a child is created to process it, and the 72 ** parent waits for completion. Return from this 73 ** routine is always in the child. The file pointers 74 ** "InChannel" and "OutChannel" should be set to point 75 ** to the communication channel. 76 */ 77 78 struct sockaddr_in SendmailAddress;/* internet address of sendmail */ 79 80 int DaemonSocket = -1; /* fd describing socket */ 81 char *NetName; /* name of home (local?) network */ 82 83 getrequests() 84 { 85 int t; 86 register struct servent *sp; 87 extern reapchild(); 88 89 /* 90 ** Set up the address for the mailer. 91 */ 92 93 sp = getservbyname("smtp", "tcp"); 94 if (sp == NULL) 95 { 96 syserr("server \"smtp\" unknown"); 97 goto severe; 98 } 99 SendmailAddress.sin_family = AF_INET; 100 SendmailAddress.sin_addr.s_addr = INADDR_ANY; 101 SendmailAddress.sin_port = sp->s_port; 102 103 /* 104 ** Try to actually open the connection. 105 */ 106 107 # ifdef DEBUG 108 if (tTd(15, 1)) 109 printf("getrequests: port 0x%x\n", SendmailAddress.sin_port); 110 # endif DEBUG 111 112 /* get a socket for the SMTP connection */ 113 DaemonSocket = socket(AF_INET, SOCK_STREAM, 0); 114 if (DaemonSocket < 0) 115 { 116 /* probably another daemon already */ 117 syserr("getrequests: can't create socket"); 118 severe: 119 # ifdef LOG 120 if (LogLevel > 0) 121 syslog(LOG_ALERT, "cannot get connection"); 122 # endif LOG 123 finis(); 124 } 125 126 #ifdef DEBUG 127 /* turn on network debugging? */ 128 if (tTd(15, 15)) 129 { 130 int on = 1; 131 (void) setsockopt(DaemonSocket, SOL_SOCKET, SO_DEBUG, (char *)&on, sizeof on); 132 } 133 #endif DEBUG 134 135 if (bind(DaemonSocket, &SendmailAddress, sizeof SendmailAddress) < 0) 136 { 137 syserr("getrequests: cannot bind"); 138 (void) close(DaemonSocket); 139 goto severe; 140 } 141 if (listen(DaemonSocket, 10) < 0) 142 { 143 syserr("getrequests: cannot listen"); 144 (void) close(DaemonSocket); 145 goto severe; 146 } 147 148 signal(SIGCHLD, reapchild); 149 150 # ifdef DEBUG 151 if (tTd(15, 1)) 152 printf("getrequests: %d\n", DaemonSocket); 153 # endif DEBUG 154 155 for (;;) 156 { 157 register int pid; 158 auto int lotherend; 159 struct sockaddr_in otherend; 160 extern int RefuseLA; 161 162 /* see if we are rejecting connections */ 163 while (getla() > RefuseLA) 164 sleep(5); 165 166 /* wait for a connection */ 167 do 168 { 169 errno = 0; 170 lotherend = sizeof otherend; 171 t = accept(DaemonSocket, &otherend, &lotherend); 172 } while (t < 0 && errno == EINTR); 173 if (t < 0) 174 { 175 syserr("getrequests: accept"); 176 sleep(5); 177 continue; 178 } 179 180 /* 181 ** Create a subprocess to process the mail. 182 */ 183 184 # ifdef DEBUG 185 if (tTd(15, 2)) 186 printf("getrequests: forking (fd = %d)\n", t); 187 # endif DEBUG 188 189 pid = fork(); 190 if (pid < 0) 191 { 192 syserr("daemon: cannot fork"); 193 sleep(10); 194 (void) close(t); 195 continue; 196 } 197 198 if (pid == 0) 199 { 200 extern struct hostent *gethostbyaddr(); 201 register struct hostent *hp; 202 char buf[MAXNAME]; 203 204 /* 205 ** CHILD -- return to caller. 206 ** Collect verified idea of sending host. 207 ** Verify calling user id if possible here. 208 */ 209 210 /* determine host name */ 211 hp = gethostbyaddr(&otherend.sin_addr, sizeof otherend.sin_addr, AF_INET); 212 if (hp != NULL) 213 { 214 (void) strcpy(buf, hp->h_name); 215 if (NetName != NULL && NetName[0] != '\0' && 216 index(hp->h_name, '.') == NULL) 217 { 218 (void) strcat(buf, "."); 219 (void) strcat(buf, NetName); 220 } 221 } 222 else 223 { 224 extern char *inet_ntoa(); 225 226 /* produce a dotted quad */ 227 (void) sprintf(buf, "[%s]", 228 inet_ntoa(otherend.sin_addr)); 229 } 230 231 /* should we check for illegal connection here? XXX */ 232 233 RealHostName = newstr(buf); 234 235 (void) close(DaemonSocket); 236 InChannel = fdopen(t, "r"); 237 OutChannel = fdopen(dup(t), "w"); 238 # ifdef DEBUG 239 if (tTd(15, 2)) 240 printf("getreq: returning\n"); 241 # endif DEBUG 242 # ifdef LOG 243 if (LogLevel > 11) 244 syslog(LOG_DEBUG, "connected, pid=%d", getpid()); 245 # endif LOG 246 return; 247 } 248 249 /* close the port so that others will hang (for a while) */ 250 (void) close(t); 251 } 252 /*NOTREACHED*/ 253 } 254 /* 255 ** REAPCHILD -- pick up the body of my child, lest it become a zombie 256 ** 257 ** Parameters: 258 ** none. 259 ** 260 ** Returns: 261 ** none. 262 ** 263 ** Side Effects: 264 ** Picks up zombies. 265 */ 266 267 reapchild() 268 { 269 union wait status; 270 271 while (wait3(&status, WNOHANG, (struct rusage *) NULL) > 0) 272 continue; 273 } 274 /* 275 ** CLRDAEMON -- reset the daemon connection 276 ** 277 ** Parameters: 278 ** none. 279 ** 280 ** Returns: 281 ** none. 282 ** 283 ** Side Effects: 284 ** releases any resources used by the passive daemon. 285 */ 286 287 clrdaemon() 288 { 289 if (DaemonSocket >= 0) 290 (void) close(DaemonSocket); 291 DaemonSocket = -1; 292 } 293 /* 294 ** MAKECONNECTION -- make a connection to an SMTP socket on another machine. 295 ** 296 ** Parameters: 297 ** host -- the name of the host. 298 ** port -- the port number to connect to. 299 ** outfile -- a pointer to a place to put the outfile 300 ** descriptor. 301 ** infile -- ditto for infile. 302 ** 303 ** Returns: 304 ** An exit code telling whether the connection could be 305 ** made and if not why not. 306 ** 307 ** Side Effects: 308 ** none. 309 */ 310 311 makeconnection(host, port, outfile, infile) 312 char *host; 313 u_short port; 314 FILE **outfile; 315 FILE **infile; 316 { 317 register int s; 318 319 /* 320 ** Set up the address for the mailer. 321 ** Accept "[a.b.c.d]" syntax for host name. 322 */ 323 324 if (host[0] == '[') 325 { 326 long hid; 327 register char *p = index(host, ']'); 328 329 if (p != NULL) 330 { 331 *p = '\0'; 332 hid = inet_addr(&host[1]); 333 *p = ']'; 334 } 335 if (p == NULL || hid == -1) 336 { 337 usrerr("Invalid numeric domain spec \"%s\"", host); 338 return (EX_NOHOST); 339 } 340 SendmailAddress.sin_addr.s_addr = hid; 341 } 342 else 343 { 344 register struct hostent *hp = gethostbyname(host); 345 346 if (errno == ETIMEDOUT) 347 { 348 CurEnv->e_flags &= ~EF_FATALERRS; 349 return (EX_TEMPFAIL); 350 } 351 if (hp == NULL) 352 return (EX_NOHOST); 353 bcopy(hp->h_addr, (char *) &SendmailAddress.sin_addr, hp->h_length); 354 } 355 356 /* 357 ** Determine the port number. 358 */ 359 360 if (port != 0) 361 SendmailAddress.sin_port = htons(port); 362 else 363 { 364 register struct servent *sp = getservbyname("smtp", "tcp"); 365 366 if (sp == NULL) 367 { 368 syserr("makeconnection: server \"smtp\" unknown"); 369 return (EX_OSFILE); 370 } 371 SendmailAddress.sin_port = sp->s_port; 372 } 373 374 /* 375 ** Try to actually open the connection. 376 */ 377 378 # ifdef DEBUG 379 if (tTd(16, 1)) 380 printf("makeconnection (%s)\n", host); 381 # endif DEBUG 382 383 s = socket(AF_INET, SOCK_STREAM, 0); 384 if (s < 0) 385 { 386 syserr("makeconnection: no socket"); 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 /* failure, decide if temporary or not */ 407 failure: 408 switch (errno) 409 { 410 case EISCONN: 411 case ETIMEDOUT: 412 case EINPROGRESS: 413 case EALREADY: 414 case EADDRINUSE: 415 case EHOSTDOWN: 416 case ENETDOWN: 417 case ENETRESET: 418 case ENOBUFS: 419 case ECONNREFUSED: 420 case ECONNRESET: 421 case EHOSTUNREACH: 422 case ENETUNREACH: 423 /* there are others, I'm sure..... */ 424 CurEnv->e_flags &= ~EF_FATALERRS; 425 return (EX_TEMPFAIL); 426 427 case EPERM: 428 /* why is this happening? */ 429 syserr("makeconnection: funny failure, addr=%lx, port=%x", 430 SendmailAddress.sin_addr.s_addr, SendmailAddress.sin_port); 431 return (EX_TEMPFAIL); 432 433 default: 434 return (EX_UNAVAILABLE); 435 } 436 } 437 438 /* connection ok, put it into canonical form */ 439 *outfile = fdopen(s, "w"); 440 *infile = fdopen(s, "r"); 441 442 return (EX_OK); 443 } 444 /* 445 ** MYHOSTNAME -- return the name of this host. 446 ** 447 ** Parameters: 448 ** hostbuf -- a place to return the name of this host. 449 ** size -- the size of hostbuf. 450 ** 451 ** Returns: 452 ** A list of aliases for this host. 453 ** 454 ** Side Effects: 455 ** none. 456 */ 457 458 char ** 459 myhostname(hostbuf, size) 460 char hostbuf[]; 461 int size; 462 { 463 extern struct hostent *gethostbyname(); 464 struct hostent *hp; 465 466 if (gethostname(hostbuf, size) < 0) 467 { 468 (void) strcpy(hostbuf, "localhost"); 469 } 470 hp = gethostbyname(hostbuf); 471 if (hp != NULL) 472 { 473 (void) strcpy(hostbuf, hp->h_name); 474 return (hp->h_aliases); 475 } 476 else 477 return (NULL); 478 } 479 /* 480 ** MAPHOSTNAME -- turn a hostname into canonical form 481 ** 482 ** Parameters: 483 ** hbuf -- a buffer containing a hostname. 484 ** hbsize -- the size of hbuf. 485 ** 486 ** Returns: 487 ** none. 488 ** 489 ** Side Effects: 490 ** Looks up the host specified in hbuf. If it is not 491 ** the canonical name for that host, replace it with 492 ** the canonical name. If the name is unknown, or it 493 ** is already the canonical name, leave it unchanged. 494 */ 495 496 maphostname(hbuf, hbsize) 497 char *hbuf; 498 int hbsize; 499 { 500 register struct hostent *hp; 501 extern struct hostent *gethostbyname(); 502 503 makelower(hbuf); 504 hp = gethostbyname(hbuf); 505 if (hp != NULL) 506 { 507 int i = strlen(hp->h_name); 508 509 if (i >= hbsize) 510 hp->h_name[--i] = '\0'; 511 (void) strcpy(hbuf, hp->h_name); 512 } 513 } 514 515 # else DAEMON 516 /* code for systems without sophisticated networking */ 517 518 /* 519 ** MYHOSTNAME -- stub version for case of no daemon code. 520 ** 521 ** Can't convert to upper case here because might be a UUCP name. 522 ** 523 ** Mark, you can change this to be anything you want...... 524 */ 525 526 char ** 527 myhostname(hostbuf, size) 528 char hostbuf[]; 529 int size; 530 { 531 register FILE *f; 532 533 hostbuf[0] = '\0'; 534 f = fopen("/usr/include/whoami", "r"); 535 if (f != NULL) 536 { 537 (void) fgets(hostbuf, size, f); 538 fixcrlf(hostbuf, TRUE); 539 (void) fclose(f); 540 } 541 return (NULL); 542 } 543 /* 544 ** MAPHOSTNAME -- turn a hostname into canonical form 545 ** 546 ** Parameters: 547 ** hbuf -- a buffer containing a hostname. 548 ** hbsize -- the size of hbuf. 549 ** 550 ** Returns: 551 ** none. 552 ** 553 ** Side Effects: 554 ** Looks up the host specified in hbuf. If it is not 555 ** the canonical name for that host, replace it with 556 ** the canonical name. If the name is unknown, or it 557 ** is already the canonical name, leave it unchanged. 558 */ 559 560 /*ARGSUSED*/ 561 maphostname(hbuf, hbsize) 562 char *hbuf; 563 int hbsize; 564 { 565 return; 566 } 567 568 569 #endif DAEMON 570