1 # include <errno.h> 2 # include "sendmail.h" 3 4 #ifndef DAEMON 5 SCCSID(@(#)daemon.c 4.12 05/24/85 (w/o daemon mode)); 6 #else 7 8 #include <sys/socket.h> 9 #include <netinet/in.h> 10 #include <netdb.h> 11 #include <sys/wait.h> 12 13 SCCSID(@(#)daemon.c 4.12 05/24/85 (with daemon mode)); 14 15 /* 16 ** DAEMON.C -- routines to use when running as a daemon. 17 ** 18 ** This entire file is highly dependent on the 4.2 BSD 19 ** interprocess communication primitives. No attempt has 20 ** been made to make this file portable to Version 7, 21 ** Version 6, MPX files, etc. If you should try such a 22 ** thing yourself, I recommend chucking the entire file 23 ** and starting from scratch. Basic semantics are: 24 ** 25 ** getrequests() 26 ** Opens a port and initiates a connection. 27 ** Returns in a child. Must set InChannel and 28 ** OutChannel appropriately. 29 ** clrdaemon() 30 ** Close any open files associated with getting 31 ** the connection; this is used when running the queue, 32 ** etc., to avoid having extra file descriptors during 33 ** the queue run and to avoid confusing the network 34 ** code (if it cares). 35 ** makeconnection(host, port, outfile, infile) 36 ** Make a connection to the named host on the given 37 ** port. Set *outfile and *infile to the files 38 ** appropriate for communication. Returns zero on 39 ** success, else an exit status describing the 40 ** error. 41 ** 42 ** The semantics of both of these should be clean. 43 */ 44 /* 45 ** GETREQUESTS -- open mail IPC port and get requests. 46 ** 47 ** Parameters: 48 ** none. 49 ** 50 ** Returns: 51 ** none. 52 ** 53 ** Side Effects: 54 ** Waits until some interesting activity occurs. When 55 ** it does, a child is created to process it, and the 56 ** parent waits for completion. Return from this 57 ** routine is always in the child. The file pointers 58 ** "InChannel" and "OutChannel" should be set to point 59 ** to the communication channel. 60 */ 61 62 struct sockaddr_in SendmailAddress;/* internet address of sendmail */ 63 64 int DaemonSocket = -1; /* fd describing socket */ 65 char *NetName; /* name of home (local?) network */ 66 67 getrequests() 68 { 69 int t; 70 union wait status; 71 register struct servent *sp; 72 73 /* 74 ** Set up the address for the mailer. 75 */ 76 77 sp = getservbyname("smtp", "tcp"); 78 if (sp == NULL) 79 { 80 syserr("server \"smtp\" unknown"); 81 goto severe; 82 } 83 SendmailAddress.sin_family = AF_INET; 84 SendmailAddress.sin_addr.s_addr = INADDR_ANY; 85 SendmailAddress.sin_port = sp->s_port; 86 87 /* 88 ** Try to actually open the connection. 89 */ 90 91 # ifdef DEBUG 92 if (tTd(15, 1)) 93 printf("getrequests: port 0x%x\n", SendmailAddress.sin_port); 94 # endif DEBUG 95 96 /* get a socket for the SMTP connection */ 97 DaemonSocket = socket(AF_INET, SOCK_STREAM, 0, 0); 98 if (DaemonSocket < 0) 99 { 100 /* probably another daemon already */ 101 syserr("getrequests: can't create socket"); 102 severe: 103 # ifdef LOG 104 if (LogLevel > 0) 105 syslog(LOG_SALERT, "cannot get connection"); 106 # endif LOG 107 finis(); 108 } 109 110 #ifdef DEBUG 111 /* turn on network debugging? */ 112 if (tTd(15, 15)) 113 (void) setsockopt(DaemonSocket, SOL_SOCKET, SO_DEBUG, 0, 0); 114 #endif DEBUG 115 116 if (bind(DaemonSocket, &SendmailAddress, sizeof SendmailAddress, 0) < 0) 117 { 118 syserr("getrequests: cannot bind"); 119 (void) close(DaemonSocket); 120 goto severe; 121 } 122 listen(DaemonSocket, 10); 123 124 # ifdef DEBUG 125 if (tTd(15, 1)) 126 printf("getrequests: %d\n", DaemonSocket); 127 # endif DEBUG 128 129 for (;;) 130 { 131 register int pid; 132 auto int lotherend; 133 struct sockaddr_in otherend; 134 extern int RefuseLA; 135 136 /* see if we are rejecting connections */ 137 while (getla() > RefuseLA) 138 sleep(5); 139 140 /* wait for a connection */ 141 do 142 { 143 errno = 0; 144 lotherend = sizeof otherend; 145 t = accept(DaemonSocket, &otherend, &lotherend, 0); 146 } while (t < 0 && errno == EINTR); 147 if (t < 0) 148 { 149 syserr("getrequests: accept"); 150 sleep(5); 151 continue; 152 } 153 154 /* 155 ** Create a subprocess to process the mail. 156 */ 157 158 # ifdef DEBUG 159 if (tTd(15, 2)) 160 printf("getrequests: forking (fd = %d)\n", t); 161 # endif DEBUG 162 163 pid = fork(); 164 if (pid < 0) 165 { 166 syserr("daemon: cannot fork"); 167 sleep(10); 168 (void) close(t); 169 continue; 170 } 171 172 if (pid == 0) 173 { 174 extern struct hostent *gethostbyaddr(); 175 register struct hostent *hp; 176 extern char *RealHostName; /* srvrsmtp.c */ 177 char buf[MAXNAME]; 178 179 /* 180 ** CHILD -- return to caller. 181 ** Collect verified idea of sending host. 182 ** Verify calling user id if possible here. 183 */ 184 185 /* determine host name */ 186 hp = gethostbyaddr(&otherend.sin_addr, sizeof otherend.sin_addr, AF_INET); 187 if (hp != NULL) 188 { 189 strcpy(buf, hp->h_name); 190 if (NetName != NULL && NetName[0] != '\0' && 191 index(hp->h_name, '.') == NULL) 192 { 193 strcat(buf, "."); 194 strcat(buf, NetName); 195 } 196 } 197 else 198 { 199 extern char *inet_ntoa(); 200 201 /* produce a dotted quad */ 202 (void) sprintf(buf, "[%s]", 203 inet_ntoa(otherend.sin_addr)); 204 } 205 206 /* should we check for illegal connection here? XXX */ 207 208 RealHostName = newstr(buf); 209 210 (void) close(DaemonSocket); 211 InChannel = fdopen(t, "r"); 212 OutChannel = fdopen(dup(t), "w"); 213 # ifdef DEBUG 214 if (tTd(15, 2)) 215 printf("getreq: returning\n"); 216 # endif DEBUG 217 # ifdef LOG 218 if (LogLevel > 11) 219 syslog(LOG_DEBUG, "connected, pid=%d", getpid()); 220 # endif LOG 221 return; 222 } 223 224 /* 225 ** PARENT -- wait for child to terminate. 226 ** Perhaps we should allow concurrent processing? 227 */ 228 229 # ifdef DEBUG 230 if (tTd(15, 2)) 231 { 232 sleep(2); 233 printf("getreq: parent waiting\n"); 234 } 235 # endif DEBUG 236 237 /* close the port so that others will hang (for a while) */ 238 (void) close(t); 239 240 /* pick up old zombies */ 241 while (wait3(&status, WNOHANG, 0) > 0) 242 continue; 243 } 244 /*NOTREACHED*/ 245 } 246 /* 247 ** CLRDAEMON -- reset the daemon connection 248 ** 249 ** Parameters: 250 ** none. 251 ** 252 ** Returns: 253 ** none. 254 ** 255 ** Side Effects: 256 ** releases any resources used by the passive daemon. 257 */ 258 259 clrdaemon() 260 { 261 if (DaemonSocket >= 0) 262 (void) close(DaemonSocket); 263 DaemonSocket = -1; 264 } 265 /* 266 ** MAKECONNECTION -- make a connection to an SMTP socket on another machine. 267 ** 268 ** Parameters: 269 ** host -- the name of the host. 270 ** port -- the port number to connect to. 271 ** outfile -- a pointer to a place to put the outfile 272 ** descriptor. 273 ** infile -- ditto for infile. 274 ** 275 ** Returns: 276 ** An exit code telling whether the connection could be 277 ** made and if not why not. 278 ** 279 ** Side Effects: 280 ** none. 281 */ 282 283 makeconnection(host, port, outfile, infile) 284 char *host; 285 u_short port; 286 FILE **outfile; 287 FILE **infile; 288 { 289 register int s; 290 291 /* 292 ** Set up the address for the mailer. 293 ** Accept "[a.b.c.d]" syntax for host name. 294 */ 295 296 if (host[0] == '[') 297 { 298 long hid; 299 register char *p = index(host, ']'); 300 301 if (p != NULL) 302 { 303 *p = '\0'; 304 hid = inet_addr(&host[1]); 305 *p = ']'; 306 } 307 if (p == NULL || hid == -1) 308 { 309 usrerr("Invalid numeric domain spec \"%s\"", host); 310 return (EX_NOHOST); 311 } 312 SendmailAddress.sin_addr.s_addr = hid; 313 } 314 else 315 { 316 register struct hostent *hp = gethostbyname(host); 317 318 if (hp == NULL) 319 return (EX_NOHOST); 320 bcopy(hp->h_addr, (char *) &SendmailAddress.sin_addr, hp->h_length); 321 } 322 323 /* 324 ** Determine the port number. 325 */ 326 327 if (port != 0) 328 SendmailAddress.sin_port = htons(port); 329 else 330 { 331 register struct servent *sp = getservbyname("smtp", "tcp"); 332 333 if (sp == NULL) 334 { 335 syserr("makeconnection: server \"smtp\" unknown"); 336 return (EX_OSFILE); 337 } 338 SendmailAddress.sin_port = sp->s_port; 339 } 340 341 /* 342 ** Try to actually open the connection. 343 */ 344 345 # ifdef DEBUG 346 if (tTd(16, 1)) 347 printf("makeconnection (%s)\n", host); 348 # endif DEBUG 349 350 s = socket(AF_INET, SOCK_STREAM, 0, 0); 351 if (s < 0) 352 { 353 syserr("makeconnection: no socket"); 354 goto failure; 355 } 356 357 # ifdef DEBUG 358 if (tTd(16, 1)) 359 printf("makeconnection: %d\n", s); 360 361 /* turn on network debugging? */ 362 if (tTd(16, 14)) 363 (void) setsockopt(s, SOL_SOCKET, SO_DEBUG, 0, 0); 364 # endif DEBUG 365 (void) fflush(CurEnv->e_xfp); /* for debugging */ 366 errno = 0; /* for debugging */ 367 SendmailAddress.sin_family = AF_INET; 368 if (connect(s, &SendmailAddress, sizeof SendmailAddress, 0) < 0) 369 { 370 /* failure, decide if temporary or not */ 371 failure: 372 switch (errno) 373 { 374 case EISCONN: 375 case ETIMEDOUT: 376 case EINPROGRESS: 377 case EALREADY: 378 case EADDRINUSE: 379 case EHOSTDOWN: 380 case ENETDOWN: 381 case ENETRESET: 382 case ENOBUFS: 383 case ECONNREFUSED: 384 case ECONNRESET: 385 case EHOSTUNREACH: 386 case ENETUNREACH: 387 /* there are others, I'm sure..... */ 388 CurEnv->e_flags &= ~EF_FATALERRS; 389 return (EX_TEMPFAIL); 390 391 case EPERM: 392 /* why is this happening? */ 393 syserr("makeconnection: funny failure, addr=%lx, port=%x", 394 SendmailAddress.sin_addr.s_addr, SendmailAddress.sin_port); 395 return (EX_TEMPFAIL); 396 397 default: 398 return (EX_UNAVAILABLE); 399 } 400 } 401 402 /* connection ok, put it into canonical form */ 403 *outfile = fdopen(s, "w"); 404 *infile = fdopen(s, "r"); 405 406 return (EX_OK); 407 } 408 /* 409 ** MYHOSTNAME -- return the name of this host. 410 ** 411 ** Parameters: 412 ** hostbuf -- a place to return the name of this host. 413 ** size -- the size of hostbuf. 414 ** 415 ** Returns: 416 ** A list of aliases for this host. 417 ** 418 ** Side Effects: 419 ** none. 420 */ 421 422 char ** 423 myhostname(hostbuf, size) 424 char hostbuf[]; 425 int size; 426 { 427 extern struct hostent *gethostbyname(); 428 struct hostent *hp; 429 430 gethostname(hostbuf, size); 431 hp = gethostbyname(hostbuf); 432 if (hp != NULL) 433 { 434 strcpy(hostbuf, hp->h_name); 435 return (hp->h_aliases); 436 } 437 else 438 return (NULL); 439 } 440 /* 441 ** MAPHOSTNAME -- turn a hostname into canonical form 442 ** 443 ** Parameters: 444 ** hbuf -- a buffer containing a hostname. 445 ** hbsize -- the size of hbuf. 446 ** 447 ** Returns: 448 ** none. 449 ** 450 ** Side Effects: 451 ** Looks up the host specified in hbuf. If it is not 452 ** the canonical name for that host, replace it with 453 ** the canonical name. If the name is unknown, or it 454 ** is already the canonical name, leave it unchanged. 455 */ 456 457 maphostname(hbuf, hbsize) 458 char *hbuf; 459 int hbsize; 460 { 461 register struct hostent *hp; 462 extern struct hostent *gethostbyname(); 463 464 makelower(hbuf); 465 hp = gethostbyname(hbuf); 466 if (hp != NULL) 467 { 468 int i = strlen(hp->h_name); 469 470 if (i >= hbsize) 471 hp->h_name[--i] = '\0'; 472 strcpy(hbuf, hp->h_name); 473 } 474 } 475 476 # else DAEMON 477 /* code for systems without sophisticated networking */ 478 479 /* 480 ** MYHOSTNAME -- stub version for case of no daemon code. 481 ** 482 ** Can't convert to upper case here because might be a UUCP name. 483 ** 484 ** Mark, you can change this to be anything you want...... 485 */ 486 487 char ** 488 myhostname(hostbuf, size) 489 char hostbuf[]; 490 int size; 491 { 492 register FILE *f; 493 494 hostbuf[0] = '\0'; 495 f = fopen("/usr/include/whoami", "r"); 496 if (f != NULL) 497 { 498 (void) fgets(hostbuf, size, f); 499 fixcrlf(hostbuf, TRUE); 500 (void) fclose(f); 501 } 502 return (NULL); 503 } 504 /* 505 ** MAPHOSTNAME -- turn a hostname into canonical form 506 ** 507 ** Parameters: 508 ** hbuf -- a buffer containing a hostname. 509 ** hbsize -- the size of hbuf. 510 ** 511 ** Returns: 512 ** none. 513 ** 514 ** Side Effects: 515 ** Looks up the host specified in hbuf. If it is not 516 ** the canonical name for that host, replace it with 517 ** the canonical name. If the name is unknown, or it 518 ** is already the canonical name, leave it unchanged. 519 */ 520 521 /*ARGSUSED*/ 522 maphostname(hbuf, hbsize) 523 char *hbuf; 524 int hbsize; 525 { 526 return; 527 } 528 529 530 #endif DAEMON 531