1 /*- 2 * Copyright (c) 1990, 1993, 1994 3 * The Regents of the University of California. All rights reserved. 4 * 5 * %sccs.include.redist.c% 6 */ 7 8 #ifndef lint 9 static char copyright[] = 10 "@(#) Copyright (c) 1990, 1993, 1994\n\ 11 The Regents of the University of California. All rights reserved.\n"; 12 #endif /* not lint */ 13 14 #ifndef lint 15 static char sccsid[] = "@(#)mail.local.c 8.7 (Berkeley) 10/17/94"; 16 #endif /* not lint */ 17 18 #include <sys/param.h> 19 #include <sys/stat.h> 20 #include <sys/socket.h> 21 22 #include <netinet/in.h> 23 24 #include <errno.h> 25 #include <fcntl.h> 26 #include <netdb.h> 27 #include <pwd.h> 28 #include <stdio.h> 29 #include <stdlib.h> 30 #include <string.h> 31 #include <sysexits.h> 32 #include <syslog.h> 33 #include <time.h> 34 #include <unistd.h> 35 36 #if __STDC__ 37 #include <stdarg.h> 38 #else 39 #include <varargs.h> 40 #endif 41 42 #ifndef LOCK_EX 43 # include <sys/file.h> 44 #endif 45 46 #ifdef BSD4_4 47 # include "pathnames.h" 48 #endif 49 50 #ifndef __P 51 # ifdef __STDC__ 52 # define __P(protos) protos 53 # else 54 # define __P(protos) () 55 # define const 56 # endif 57 #endif 58 #ifndef __dead 59 # if defined(__GNUC__) && (__GNUC__ < 2 || __GNUC_MINOR__ < 5) && !defined(__STRICT_ANSI__) 60 # define __dead __volatile 61 # else 62 # define __dead 63 # endif 64 #endif 65 66 #ifndef BSD4_4 67 # define _BSD_VA_LIST_ va_list 68 extern char *strerror __P((int)); 69 #endif 70 71 #ifndef _PATH_LOCTMP 72 # define _PATH_LOCTMP "/tmp/local.XXXXXX" 73 #endif 74 #ifndef _PATH_MAILDIR 75 # define _PATH_MAILDIR "/var/spool/mail" 76 #endif 77 78 #ifndef S_ISLNK 79 # define S_ISLNK(mode) (((mode) & _S_IFMT) == S_IFLNK) 80 #endif 81 82 int eval = EX_OK; /* sysexits.h error value. */ 83 84 void deliver __P((int, char *)); 85 void e_to_sys __P((int)); 86 __dead void err __P((const char *, ...)); 87 void notifybiff __P((char *)); 88 int store __P((char *)); 89 void usage __P((void)); 90 void vwarn __P((const char *, _BSD_VA_LIST_)); 91 void warn __P((const char *, ...)); 92 93 int 94 main(argc, argv) 95 int argc; 96 char *argv[]; 97 { 98 struct passwd *pw; 99 int ch, fd; 100 uid_t uid; 101 char *from; 102 extern char *optarg; 103 extern int optind; 104 105 #ifdef LOG_MAIL 106 openlog("mail.local", 0, LOG_MAIL); 107 #else 108 openlog("mail.local", 0); 109 #endif 110 111 from = NULL; 112 while ((ch = getopt(argc, argv, "df:r:")) != EOF) 113 switch(ch) { 114 case 'd': /* Backward compatible. */ 115 break; 116 case 'f': 117 case 'r': /* Backward compatible. */ 118 if (from != NULL) { 119 warn("multiple -f options"); 120 usage(); 121 } 122 from = optarg; 123 break; 124 case '?': 125 default: 126 usage(); 127 } 128 argc -= optind; 129 argv += optind; 130 131 if (!*argv) 132 usage(); 133 134 /* 135 * If from not specified, use the name from getlogin() if the 136 * uid matches, otherwise, use the name from the password file 137 * corresponding to the uid. 138 */ 139 uid = getuid(); 140 if (!from && (!(from = getlogin()) || 141 !(pw = getpwnam(from)) || pw->pw_uid != uid)) 142 from = (pw = getpwuid(uid)) ? pw->pw_name : "???"; 143 144 /* 145 * There is no way to distinguish the error status of one delivery 146 * from the rest of the deliveries. So, if we failed hard on one 147 * or more deliveries, but had no failures on any of the others, we 148 * return a hard failure. If we failed temporarily on one or more 149 * deliveries, we return a temporary failure regardless of the other 150 * failures. This results in the delivery being reattempted later 151 * at the expense of repeated failures and multiple deliveries. 152 */ 153 for (fd = store(from); *argv; ++argv) 154 deliver(fd, *argv); 155 exit(eval); 156 } 157 158 int 159 store(from) 160 char *from; 161 { 162 FILE *fp; 163 time_t tval; 164 int fd, eline; 165 char line[2048]; 166 char tmpbuf[sizeof _PATH_LOCTMP + 1]; 167 168 strcpy(tmpbuf, _PATH_LOCTMP); 169 if ((fd = mkstemp(tmpbuf)) == -1 || (fp = fdopen(fd, "w+")) == NULL) { 170 e_to_sys(errno); 171 err("unable to open temporary file"); 172 } 173 (void)unlink(tmpbuf); 174 175 (void)time(&tval); 176 (void)fprintf(fp, "From %s %s", from, ctime(&tval)); 177 178 line[0] = '\0'; 179 for (eline = 1; fgets(line, sizeof(line), stdin);) { 180 if (line[0] == '\n') 181 eline = 1; 182 else { 183 if (eline && line[0] == 'F' && 184 !memcmp(line, "From ", 5)) 185 (void)putc('>', fp); 186 eline = 0; 187 } 188 (void)fprintf(fp, "%s", line); 189 if (ferror(fp)) { 190 e_to_sys(errno); 191 err("temporary file write error"); 192 } 193 } 194 195 /* If message not newline terminated, need an extra. */ 196 if (!strchr(line, '\n')) 197 (void)putc('\n', fp); 198 /* Output a newline; note, empty messages are allowed. */ 199 (void)putc('\n', fp); 200 201 if (fflush(fp) == EOF || ferror(fp)) { 202 e_to_sys(errno); 203 err("temporary file write error"); 204 } 205 return (fd); 206 } 207 208 void 209 deliver(fd, name) 210 int fd; 211 char *name; 212 { 213 struct stat fsb, sb; 214 struct passwd *pw; 215 int mbfd, nr, nw, off; 216 char biffmsg[100], buf[8*1024], path[MAXPATHLEN]; 217 off_t curoff; 218 219 /* 220 * Disallow delivery to unknown names -- special mailboxes can be 221 * handled in the sendmail aliases file. 222 */ 223 if (!(pw = getpwnam(name))) { 224 if (eval != EX_TEMPFAIL) 225 eval = EX_UNAVAILABLE; 226 warn("unknown name: %s", name); 227 return; 228 } 229 230 (void)snprintf(path, sizeof(path), "%s/%s", _PATH_MAILDIR, name); 231 232 /* 233 * If the mailbox is linked or a symlink, fail. There's an obvious 234 * race here, that the file was replaced with a symbolic link after 235 * the lstat returned, but before the open. We attempt to detect 236 * this by comparing the original stat information and information 237 * returned by an fstat of the file descriptor returned by the open. 238 * 239 * NB: this is a symptom of a larger problem, that the mail spooling 240 * directory is writeable by the wrong users. If that directory is 241 * writeable, system security is compromised for other reasons, and 242 * it cannot be fixed here. 243 * 244 * If we created the mailbox, set the owner/group. If that fails, 245 * just return. Another process may have already opened it, so we 246 * can't unlink it. Historically, binmail set the owner/group at 247 * each mail delivery. We no longer do this, assuming that if the 248 * ownership or permissions were changed there was a reason. 249 * 250 * XXX 251 * open(2) should support flock'ing the file. 252 */ 253 tryagain: 254 if (lstat(path, &sb)) { 255 mbfd = open(path, 256 O_APPEND|O_CREAT|O_EXCL|O_WRONLY, S_IRUSR|S_IWUSR); 257 if (mbfd == -1) { 258 if (errno == EEXIST) 259 goto tryagain; 260 } else if (fchown(mbfd, pw->pw_uid, pw->pw_gid)) { 261 e_to_sys(errno); 262 warn("chown %u.%u: %s", pw->pw_uid, pw->pw_gid, name); 263 return; 264 } 265 } else if (sb.st_nlink != 1 || S_ISLNK(sb.st_mode)) { 266 e_to_sys(errno); 267 warn("%s: linked file", path); 268 return; 269 } else { 270 mbfd = open(path, O_APPEND|O_WRONLY, 0); 271 if (mbfd != -1 && 272 (fstat(mbfd, &fsb) || fsb.st_nlink != 1 || 273 S_ISLNK(fsb.st_mode) || sb.st_dev != fsb.st_dev || 274 sb.st_ino != fsb.st_ino)) { 275 warn("%s: file changed after open", path); 276 (void)close(mbfd); 277 return; 278 } 279 } 280 281 if (mbfd == -1) { 282 e_to_sys(errno); 283 warn("%s: %s", path, strerror(errno)); 284 return; 285 } 286 287 /* Wait until we can get a lock on the file. */ 288 if (flock(mbfd, LOCK_EX)) { 289 e_to_sys(errno); 290 warn("%s: %s", path, strerror(errno)); 291 goto err1; 292 } 293 294 /* Get the starting offset of the new message for biff. */ 295 curoff = lseek(mbfd, (off_t)0, SEEK_END); 296 (void)snprintf(biffmsg, sizeof(biffmsg), "%s@%qd\n", name, curoff); 297 298 /* Copy the message into the file. */ 299 if (lseek(fd, (off_t)0, SEEK_SET) == (off_t)-1) { 300 e_to_sys(errno); 301 warn("temporary file: %s", strerror(errno)); 302 goto err1; 303 } 304 while ((nr = read(fd, buf, sizeof(buf))) > 0) 305 for (off = 0; off < nr; nr -= nw, off += nw) 306 if ((nw = write(mbfd, buf + off, nr)) < 0) { 307 e_to_sys(errno); 308 warn("%s: %s", path, strerror(errno)); 309 goto err2;; 310 } 311 if (nr < 0) { 312 e_to_sys(errno); 313 warn("temporary file: %s", strerror(errno)); 314 goto err2;; 315 } 316 317 /* Flush to disk, don't wait for update. */ 318 if (fsync(mbfd)) { 319 e_to_sys(errno); 320 warn("%s: %s", path, strerror(errno)); 321 err2: (void)ftruncate(mbfd, curoff); 322 err1: (void)close(mbfd); 323 return; 324 } 325 326 /* Close and check -- NFS doesn't write until the close. */ 327 if (close(mbfd)) { 328 e_to_sys(errno); 329 warn("%s: %s", path, strerror(errno)); 330 return; 331 } 332 333 notifybiff(biffmsg); 334 } 335 336 void 337 notifybiff(msg) 338 char *msg; 339 { 340 static struct sockaddr_in addr; 341 static int f = -1; 342 struct hostent *hp; 343 struct servent *sp; 344 int len; 345 346 if (!addr.sin_family) { 347 /* Be silent if biff service not available. */ 348 if (!(sp = getservbyname("biff", "udp"))) 349 return; 350 if (!(hp = gethostbyname("localhost"))) { 351 warn("localhost: %s", strerror(errno)); 352 return; 353 } 354 addr.sin_family = hp->h_addrtype; 355 memcpy(&addr.sin_addr, hp->h_addr, hp->h_length); 356 addr.sin_port = sp->s_port; 357 } 358 if (f < 0 && (f = socket(AF_INET, SOCK_DGRAM, 0)) == -1) { 359 warn("socket: %s", strerror(errno)); 360 return; 361 } 362 len = strlen(msg) + 1; 363 if (sendto(f, msg, len, 0, (struct sockaddr *)&addr, sizeof(addr)) 364 != len) 365 warn("sendto biff: %s", strerror(errno)); 366 } 367 368 void 369 usage() 370 { 371 eval = EX_USAGE; 372 err("usage: mail.local [-f from] user ..."); 373 } 374 375 #if __STDC__ 376 void 377 err(const char *fmt, ...) 378 #else 379 void 380 err(fmt, va_alist) 381 const char *fmt; 382 va_dcl 383 #endif 384 { 385 va_list ap; 386 387 #if __STDC__ 388 va_start(ap, fmt); 389 #else 390 va_start(ap); 391 #endif 392 vwarn(fmt, ap); 393 va_end(ap); 394 395 exit(eval); 396 } 397 398 void 399 #if __STDC__ 400 warn(const char *fmt, ...) 401 #else 402 warn(fmt, va_alist) 403 const char *fmt; 404 va_dcl 405 #endif 406 { 407 va_list ap; 408 409 #if __STDC__ 410 va_start(ap, fmt); 411 #else 412 va_start(ap); 413 #endif 414 vwarn(fmt, ap); 415 va_end(ap); 416 } 417 418 void 419 vwarn(fmt, ap) 420 const char *fmt; 421 _BSD_VA_LIST_ ap; 422 { 423 /* 424 * Log the message to stderr. 425 * 426 * Don't use LOG_PERROR as an openlog() flag to do this, 427 * it's not portable enough. 428 */ 429 if (eval != EX_USAGE) 430 (void)fprintf(stderr, "mail.local: "); 431 (void)vfprintf(stderr, fmt, ap); 432 (void)fprintf(stderr, "\n"); 433 434 #ifndef ultrix 435 /* Log the message to syslog. */ 436 vsyslog(LOG_ERR, fmt, ap); 437 #else 438 { 439 char fmtbuf[10240]; 440 441 (void) sprintf(fmtbuf, fmt, ap); 442 syslog(LOG_ERR, "%s", fmtbuf); 443 } 444 #endif 445 } 446 447 /* 448 * e_to_sys -- 449 * Guess which errno's are temporary. Gag me. 450 */ 451 void 452 e_to_sys(num) 453 int num; 454 { 455 /* Temporary failures override hard errors. */ 456 if (eval == EX_TEMPFAIL) 457 return; 458 459 switch(num) { /* Hopefully temporary errors. */ 460 #ifdef EAGAIN 461 case EAGAIN: /* Resource temporarily unavailable */ 462 #endif 463 #ifdef EDQUOT 464 case EDQUOT: /* Disc quota exceeded */ 465 #endif 466 #ifdef EBUSY 467 case EBUSY: /* Device busy */ 468 #endif 469 #ifdef EPROCLIM 470 case EPROCLIM: /* Too many processes */ 471 #endif 472 #ifdef EUSERS 473 case EUSERS: /* Too many users */ 474 #endif 475 #ifdef ECONNABORTED 476 case ECONNABORTED: /* Software caused connection abort */ 477 #endif 478 #ifdef ECONNREFUSED 479 case ECONNREFUSED: /* Connection refused */ 480 #endif 481 #ifdef ECONNRESET 482 case ECONNRESET: /* Connection reset by peer */ 483 #endif 484 #ifdef EDEADLK 485 case EDEADLK: /* Resource deadlock avoided */ 486 #endif 487 #ifdef EFBIG 488 case EFBIG: /* File too large */ 489 #endif 490 #ifdef EHOSTDOWN 491 case EHOSTDOWN: /* Host is down */ 492 #endif 493 #ifdef EHOSTUNREACH 494 case EHOSTUNREACH: /* No route to host */ 495 #endif 496 #ifdef EMFILE 497 case EMFILE: /* Too many open files */ 498 #endif 499 #ifdef ENETDOWN 500 case ENETDOWN: /* Network is down */ 501 #endif 502 #ifdef ENETRESET 503 case ENETRESET: /* Network dropped connection on reset */ 504 #endif 505 #ifdef ENETUNREACH 506 case ENETUNREACH: /* Network is unreachable */ 507 #endif 508 #ifdef ENFILE 509 case ENFILE: /* Too many open files in system */ 510 #endif 511 #ifdef ENOBUFS 512 case ENOBUFS: /* No buffer space available */ 513 #endif 514 #ifdef ENOMEM 515 case ENOMEM: /* Cannot allocate memory */ 516 #endif 517 #ifdef ENOSPC 518 case ENOSPC: /* No space left on device */ 519 #endif 520 #ifdef EROFS 521 case EROFS: /* Read-only file system */ 522 #endif 523 #ifdef ESTALE 524 case ESTALE: /* Stale NFS file handle */ 525 #endif 526 #ifdef ETIMEDOUT 527 case ETIMEDOUT: /* Connection timed out */ 528 #endif 529 #if defined(EWOULDBLOCK) && EWOULDBLOCK != EAGAIN && EWOULDBLOCK != EDEADLK 530 case EWOULDBLOCK: /* Operation would block. */ 531 #endif 532 eval = EX_TEMPFAIL; 533 break; 534 default: 535 eval = EX_UNAVAILABLE; 536 break; 537 } 538 } 539 540 #ifndef BSD4_4 541 542 char * 543 strerror(eno) 544 int eno; 545 { 546 extern int sys_nerr; 547 extern char *sys_errlist[]; 548 static char ebuf[60]; 549 550 if (eno >= 0 && eno <= sys_nerr) 551 return sys_errlist[eno]; 552 (void) sprintf(ebuf, "Error %d", eno); 553 return ebuf; 554 } 555 556 #if __STDC__ 557 snprintf(char *buf, int bufsiz, const char *fmt, ...) 558 #else 559 snprintf(buf, bufsiz, fmt, va_alist) 560 char *buf; 561 int bufsiz; 562 const char *fmt; 563 va_dcl 564 #endif 565 { 566 va_list ap; 567 568 #if __STDC__ 569 va_start(ap, fmt); 570 #else 571 va_start(ap); 572 #endif 573 vsprintf(buf, fmt, ap); 574 va_end(ap); 575 } 576 577 #endif 578 579 #ifdef ultrix 580 581 int 582 mkstemp(template) 583 char *template; 584 { 585 int fd; 586 587 return open(mktemp(template), O_RDWR|O_CREAT|O_EXCL, 0600); 588 } 589 590 #endif 591