1 /* $OpenBSD: authpf.c,v 1.120 2014/04/02 02:12:24 deraadt Exp $ */ 2 3 /* 4 * Copyright (C) 1998 - 2007 Bob Beck (beck@openbsd.org). 5 * 6 * Permission to use, copy, modify, and distribute this software for any 7 * purpose with or without fee is hereby granted, provided that the above 8 * copyright notice and this permission notice appear in all copies. 9 * 10 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES 11 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF 12 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR 13 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 14 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN 15 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF 16 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 17 */ 18 19 #include <sys/types.h> 20 #include <sys/file.h> 21 #include <sys/ioctl.h> 22 #include <sys/socket.h> 23 #include <sys/stat.h> 24 #include <sys/time.h> 25 #include <sys/wait.h> 26 27 #include <net/if.h> 28 #include <net/pfvar.h> 29 #include <arpa/inet.h> 30 31 #include <err.h> 32 #include <errno.h> 33 #include <login_cap.h> 34 #include <pwd.h> 35 #include <grp.h> 36 #include <signal.h> 37 #include <stdio.h> 38 #include <stdlib.h> 39 #include <string.h> 40 #include <syslog.h> 41 #include <unistd.h> 42 43 #include "pathnames.h" 44 45 static int read_config(FILE *); 46 static void print_message(char *); 47 static int allowed_luser(struct passwd *); 48 static int check_luser(char *, char *); 49 static int remove_stale_rulesets(void); 50 static int recursive_ruleset_purge(char *, char *); 51 static int change_filter(int, const char *, const char *); 52 static int change_table(int, const char *); 53 static void authpf_kill_states(void); 54 55 int dev; /* pf device */ 56 char anchorname[PF_ANCHOR_NAME_SIZE] = "authpf"; 57 char rulesetname[MAXPATHLEN - PF_ANCHOR_NAME_SIZE - 2]; 58 char tablename[PF_TABLE_NAME_SIZE] = "authpf_users"; 59 int user_ip = 1; /* controls whether $user_ip is set */ 60 61 FILE *pidfp; 62 int pidfd = -1; 63 char luser[MAXLOGNAME]; /* username */ 64 char ipsrc[256]; /* ip as a string */ 65 char pidfile[MAXPATHLEN]; /* we save pid in this file. */ 66 67 struct timeval Tstart, Tend; /* start and end times of session */ 68 69 volatile sig_atomic_t want_death; 70 static void need_death(int signo); 71 static __dead void do_death(int); 72 extern char *__progname; /* program name */ 73 74 /* 75 * User shell for authenticating gateways. Sole purpose is to allow 76 * a user to ssh to a gateway, and have the gateway modify packet 77 * filters to allow access, then remove access when the user finishes 78 * up. Meant to be used only from ssh(1) connections. 79 */ 80 int 81 main(int argc, char *argv[]) 82 { 83 int lockcnt = 0, n; 84 FILE *config; 85 struct in6_addr ina; 86 struct passwd *pw; 87 char *cp; 88 gid_t gid; 89 uid_t uid; 90 char *shell; 91 login_cap_t *lc; 92 93 if (strcmp(__progname, "-authpf-noip") == 0) 94 user_ip = 0; 95 96 config = fopen(PATH_CONFFILE, "r"); 97 if (config == NULL) { 98 syslog(LOG_ERR, "cannot open %s (%m)", PATH_CONFFILE); 99 exit(1); 100 } 101 102 if ((cp = getenv("SSH_TTY")) == NULL) { 103 syslog(LOG_ERR, "non-interactive session connection for authpf"); 104 exit(1); 105 } 106 107 if ((cp = getenv("SSH_CLIENT")) == NULL) { 108 syslog(LOG_ERR, "cannot determine connection source"); 109 exit(1); 110 } 111 112 if (strlcpy(ipsrc, cp, sizeof(ipsrc)) >= sizeof(ipsrc)) { 113 syslog(LOG_ERR, "SSH_CLIENT variable too long"); 114 exit(1); 115 } 116 cp = strchr(ipsrc, ' '); 117 if (!cp) { 118 syslog(LOG_ERR, "corrupt SSH_CLIENT variable %s", ipsrc); 119 exit(1); 120 } 121 *cp = '\0'; 122 if (inet_pton(AF_INET, ipsrc, &ina) != 1 && 123 inet_pton(AF_INET6, ipsrc, &ina) != 1) { 124 syslog(LOG_ERR, 125 "cannot determine IP from SSH_CLIENT %s", ipsrc); 126 exit(1); 127 } 128 /* open the pf device */ 129 dev = open(PATH_DEVFILE, O_RDWR); 130 if (dev == -1) { 131 syslog(LOG_ERR, "cannot open packet filter device (%m)"); 132 goto die; 133 } 134 135 uid = getuid(); 136 pw = getpwuid(uid); 137 if (pw == NULL) { 138 syslog(LOG_ERR, "cannot find user for uid %u", uid); 139 goto die; 140 } 141 142 if ((lc = login_getclass(pw->pw_class)) != NULL) 143 shell = login_getcapstr(lc, "shell", pw->pw_shell, 144 pw->pw_shell); 145 else 146 shell = pw->pw_shell; 147 148 login_close(lc); 149 150 if (strcmp(shell, PATH_AUTHPF_SHELL) && 151 strcmp(shell, PATH_AUTHPF_SHELL_NOIP)) { 152 syslog(LOG_ERR, "wrong shell for user %s, uid %u", 153 pw->pw_name, pw->pw_uid); 154 if (shell != pw->pw_shell) 155 free(shell); 156 goto die; 157 } 158 159 if (shell != pw->pw_shell) 160 free(shell); 161 162 /* 163 * Paranoia, but this data _does_ come from outside authpf, and 164 * truncation would be bad. 165 */ 166 if (strlcpy(luser, pw->pw_name, sizeof(luser)) >= sizeof(luser)) { 167 syslog(LOG_ERR, "username too long: %s", pw->pw_name); 168 goto die; 169 } 170 171 if ((n = snprintf(rulesetname, sizeof(rulesetname), "%s(%ld)", 172 luser, (long)getpid())) < 0 || (u_int)n >= sizeof(rulesetname)) { 173 syslog(LOG_INFO, "%s(%ld) too large, ruleset name will be %ld", 174 luser, (long)getpid(), (long)getpid()); 175 if ((n = snprintf(rulesetname, sizeof(rulesetname), "%ld", 176 (long)getpid())) < 0 || (u_int)n >= sizeof(rulesetname)) { 177 syslog(LOG_ERR, "pid too large for ruleset name"); 178 goto die; 179 } 180 } 181 182 183 /* Make our entry in /var/authpf as ipaddr or username */ 184 n = snprintf(pidfile, sizeof(pidfile), "%s/%s", 185 PATH_PIDFILE, user_ip ? ipsrc : luser); 186 if (n < 0 || (u_int)n >= sizeof(pidfile)) { 187 syslog(LOG_ERR, "path to pidfile too long"); 188 goto die; 189 } 190 191 signal(SIGTERM, need_death); 192 signal(SIGINT, need_death); 193 signal(SIGALRM, need_death); 194 signal(SIGPIPE, need_death); 195 signal(SIGHUP, need_death); 196 signal(SIGQUIT, need_death); 197 signal(SIGTSTP, need_death); 198 199 /* 200 * If someone else is already using this ip, then this person 201 * wants to switch users - so kill the old process and exit 202 * as well. 203 * 204 * Note, we could print a message and tell them to log out, but the 205 * usual case of this is that someone has left themselves logged in, 206 * with the authenticated connection iconized and someone else walks 207 * up to use and automatically logs in before using. If this just 208 * gets rid of the old one silently, the new user never knows they 209 * could have used someone else's old authentication. If we 210 * tell them to log out before switching users it is an invitation 211 * for abuse. 212 */ 213 214 do { 215 int save_errno, otherpid = -1; 216 char otherluser[MAXLOGNAME]; 217 218 if ((pidfd = open(pidfile, O_RDWR|O_CREAT, 0644)) == -1 || 219 (pidfp = fdopen(pidfd, "r+")) == NULL) { 220 if (pidfd != -1) 221 close(pidfd); 222 syslog(LOG_ERR, "cannot open or create %s: %s", pidfile, 223 strerror(errno)); 224 goto die; 225 } 226 227 if (flock(fileno(pidfp), LOCK_EX|LOCK_NB) == 0) 228 break; 229 save_errno = errno; 230 231 /* Mark our pid, and username to our file. */ 232 233 rewind(pidfp); 234 /* 31 == MAXLOGNAME - 1 */ 235 if (fscanf(pidfp, "%d\n%31s\n", &otherpid, otherluser) != 2) 236 otherpid = -1; 237 syslog(LOG_DEBUG, "tried to lock %s, in use by pid %d: %s", 238 pidfile, otherpid, strerror(save_errno)); 239 240 if (otherpid > 0) { 241 syslog(LOG_INFO, 242 "killing prior auth (pid %d) of %s by user %s", 243 otherpid, ipsrc, otherluser); 244 if (kill((pid_t) otherpid, SIGTERM) == -1) { 245 syslog(LOG_INFO, 246 "could not kill process %d: (%m)", 247 otherpid); 248 } 249 } 250 251 /* 252 * We try to kill the previous process and acquire the lock 253 * for 10 seconds, trying once a second. if we can't after 254 * 10 attempts we log an error and give up. 255 */ 256 if (want_death || ++lockcnt > 10) { 257 if (!want_death) 258 syslog(LOG_ERR, "cannot kill previous authpf (pid %d)", 259 otherpid); 260 fclose(pidfp); 261 pidfp = NULL; 262 pidfd = -1; 263 goto dogdeath; 264 } 265 sleep(1); 266 267 /* re-open, and try again. The previous authpf process 268 * we killed above should unlink the file and release 269 * it's lock, giving us a chance to get it now 270 */ 271 fclose(pidfp); 272 pidfp = NULL; 273 pidfd = -1; 274 } while (1); 275 276 /* whack the group list */ 277 gid = getegid(); 278 if (setgroups(1, &gid) == -1) { 279 syslog(LOG_INFO, "setgroups: %s", strerror(errno)); 280 do_death(0); 281 } 282 283 /* revoke privs */ 284 uid = getuid(); 285 if (setresuid(uid, uid, uid) == -1) { 286 syslog(LOG_INFO, "setresuid: %s", strerror(errno)); 287 do_death(0); 288 } 289 openlog("authpf", LOG_PID | LOG_NDELAY, LOG_DAEMON); 290 291 if (!check_luser(PATH_BAN_DIR, luser) || !allowed_luser(pw)) { 292 syslog(LOG_INFO, "user %s prohibited", luser); 293 do_death(0); 294 } 295 296 if (read_config(config)) { 297 syslog(LOG_ERR, "invalid config file %s", PATH_CONFFILE); 298 do_death(0); 299 } 300 301 if (remove_stale_rulesets()) { 302 syslog(LOG_INFO, "error removing stale rulesets"); 303 do_death(0); 304 } 305 306 /* We appear to be making headway, so actually mark our pid */ 307 rewind(pidfp); 308 fprintf(pidfp, "%ld\n%s\n", (long)getpid(), luser); 309 fflush(pidfp); 310 (void) ftruncate(fileno(pidfp), ftello(pidfp)); 311 312 if (change_filter(1, luser, ipsrc) == -1) { 313 printf("Unable to modify filters\r\n"); 314 do_death(0); 315 } 316 if (user_ip && change_table(1, ipsrc) == -1) { 317 printf("Unable to modify table\r\n"); 318 change_filter(0, luser, ipsrc); 319 do_death(0); 320 } 321 322 while (1) { 323 struct stat sb; 324 char *path_message; 325 printf("\r\nHello %s. ", luser); 326 printf("You are authenticated from host \"%s\"\r\n", ipsrc); 327 setproctitle("%s@%s", luser, ipsrc); 328 if (asprintf(&path_message, "%s/%s/authpf.message", 329 PATH_USER_DIR, luser) == -1) 330 do_death(1); 331 if (stat(path_message, &sb) == -1 || ! S_ISREG(sb.st_mode)) { 332 free(path_message); 333 if ((path_message = strdup(PATH_MESSAGE)) == NULL) 334 do_death(1); 335 } 336 print_message(path_message); 337 while (1) { 338 sleep(10); 339 if (want_death) 340 do_death(1); 341 } 342 } 343 344 /* NOTREACHED */ 345 dogdeath: 346 printf("\r\n\r\nSorry, this service is currently unavailable due to "); 347 printf("technical difficulties\r\n\r\n"); 348 print_message(PATH_PROBLEM); 349 printf("\r\nYour authentication process (pid %ld) was unable to run\n", 350 (long)getpid()); 351 sleep(180); /* them lusers read reaaaaal slow */ 352 die: 353 do_death(0); 354 } 355 356 /* 357 * reads config file in PATH_CONFFILE to set optional behaviours up 358 */ 359 static int 360 read_config(FILE *f) 361 { 362 char buf[1024]; 363 int i = 0; 364 365 do { 366 char **ap; 367 char *pair[4], *cp, *tp; 368 int len; 369 370 if (fgets(buf, sizeof(buf), f) == NULL) { 371 fclose(f); 372 return (0); 373 } 374 i++; 375 len = strlen(buf); 376 if (len == 0) 377 continue; 378 if (buf[len - 1] != '\n' && !feof(f)) { 379 syslog(LOG_ERR, "line %d too long in %s", i, 380 PATH_CONFFILE); 381 return (1); 382 } 383 buf[len - 1] = '\0'; 384 385 for (cp = buf; *cp == ' ' || *cp == '\t'; cp++) 386 ; /* nothing */ 387 388 if (!*cp || *cp == '#' || *cp == '\n') 389 continue; 390 391 for (ap = pair; ap < &pair[3] && 392 (*ap = strsep(&cp, "=")) != NULL; ) { 393 if (**ap != '\0') 394 ap++; 395 } 396 if (ap != &pair[2]) 397 goto parse_error; 398 399 tp = pair[1] + strlen(pair[1]); 400 while ((*tp == ' ' || *tp == '\t') && tp >= pair[1]) 401 *tp-- = '\0'; 402 403 if (strcasecmp(pair[0], "anchor") == 0) { 404 if (!pair[1][0] || strlcpy(anchorname, pair[1], 405 sizeof(anchorname)) >= sizeof(anchorname)) 406 goto parse_error; 407 } 408 if (strcasecmp(pair[0], "table") == 0) { 409 if (!pair[1][0] || strlcpy(tablename, pair[1], 410 sizeof(tablename)) >= sizeof(tablename)) 411 goto parse_error; 412 } 413 } while (!feof(f) && !ferror(f)); 414 fclose(f); 415 return (0); 416 417 parse_error: 418 fclose(f); 419 syslog(LOG_ERR, "parse error, line %d of %s", i, PATH_CONFFILE); 420 return (1); 421 } 422 423 424 /* 425 * splatter a file to stdout - max line length of 1024, 426 * used for spitting message files at users to tell them 427 * they've been bad or we're unavailable. 428 */ 429 static void 430 print_message(char *filename) 431 { 432 char buf[1024]; 433 FILE *f; 434 435 if ((f = fopen(filename, "r")) == NULL) 436 return; /* fail silently, we don't care if it isn't there */ 437 438 do { 439 if (fgets(buf, sizeof(buf), f) == NULL) { 440 fflush(stdout); 441 fclose(f); 442 return; 443 } 444 } while (fputs(buf, stdout) != EOF && !feof(f)); 445 fflush(stdout); 446 fclose(f); 447 } 448 449 /* 450 * allowed_luser checks to see if user "luser" is allowed to 451 * use this gateway by virtue of being listed in an allowed 452 * users file, namely /etc/authpf/authpf.allow . 453 * Users may be listed by <username>, %<group>, or @<login_class>. 454 * 455 * If /etc/authpf/authpf.allow does not exist, then we assume that 456 * all users who are allowed in by sshd(8) are permitted to 457 * use this gateway. If /etc/authpf/authpf.allow does exist, then a 458 * user must be listed if the connection is to continue, else 459 * the session terminates in the same manner as being banned. 460 */ 461 static int 462 allowed_luser(struct passwd *pw) 463 { 464 char *buf, *lbuf; 465 int matched; 466 size_t len; 467 FILE *f; 468 469 if ((f = fopen(PATH_ALLOWFILE, "r")) == NULL) { 470 if (errno == ENOENT) { 471 /* 472 * allowfile doesn't exist, thus this gateway 473 * isn't restricted to certain users... 474 */ 475 return (1); 476 } 477 478 /* 479 * luser may in fact be allowed, but we can't open 480 * the file even though it's there. probably a config 481 * problem. 482 */ 483 syslog(LOG_ERR, "cannot open allowed users file %s (%s)", 484 PATH_ALLOWFILE, strerror(errno)); 485 return (0); 486 } else { 487 /* 488 * /etc/authpf/authpf.allow exists, thus we do a linear 489 * search to see if they are allowed. 490 * also, if username "*" exists, then this is a 491 * "public" gateway, such as it is, so let 492 * everyone use it. 493 */ 494 int gl_init = 0, ngroups = NGROUPS + 1; 495 gid_t groups[NGROUPS + 1]; 496 497 lbuf = NULL; 498 matched = 0; 499 500 while ((buf = fgetln(f, &len))) { 501 502 if (buf[len - 1] == '\n') 503 buf[len - 1] = '\0'; 504 else { 505 if ((lbuf = (char *)malloc(len + 1)) == NULL) 506 err(1, NULL); 507 memcpy(lbuf, buf, len); 508 lbuf[len] = '\0'; 509 buf = lbuf; 510 } 511 512 if (buf[0] == '@') { 513 /* check login class */ 514 if (strcmp(pw->pw_class, buf + 1) == 0) 515 matched++; 516 } else if (buf[0] == '%') { 517 /* check group membership */ 518 int cnt; 519 struct group *group; 520 521 if ((group = getgrnam(buf + 1)) == NULL) { 522 syslog(LOG_ERR, 523 "invalid group '%s' in %s (%s)", 524 buf + 1, PATH_ALLOWFILE, 525 strerror(errno)); 526 fclose(f); 527 return (0); 528 } 529 530 if (!gl_init) { 531 (void) getgrouplist(pw->pw_name, 532 pw->pw_gid, groups, &ngroups); 533 gl_init++; 534 } 535 536 for ( cnt = 0; cnt < ngroups; cnt++) { 537 if (group->gr_gid == groups[cnt]) { 538 matched++; 539 break; 540 } 541 } 542 } else { 543 /* check username and wildcard */ 544 matched = strcmp(pw->pw_name, buf) == 0 || 545 strcmp("*", buf) == 0; 546 } 547 548 if (lbuf != NULL) { 549 free(lbuf); 550 lbuf = NULL; 551 } 552 553 if (matched) { 554 fclose(f); 555 return (1); /* matched an allowed user/group */ 556 } 557 } 558 syslog(LOG_INFO, "denied access to %s: not listed in %s", 559 pw->pw_name, PATH_ALLOWFILE); 560 561 /* reuse buf */ 562 buf = "\n\nSorry, you are not allowed to use this facility!\n"; 563 fputs(buf, stdout); 564 } 565 fflush(stdout); 566 fclose(f); 567 return (0); 568 } 569 570 /* 571 * check_luser checks to see if user "luser" has been banned 572 * from using us by virtue of having an file of the same name 573 * in the "luserdir" directory. 574 * 575 * If the user has been banned, we copy the contents of the file 576 * to the user's screen. (useful for telling the user what to 577 * do to get un-banned, or just to tell them they aren't 578 * going to be un-banned.) 579 */ 580 static int 581 check_luser(char *luserdir, char *luser) 582 { 583 FILE *f; 584 int n; 585 char tmp[MAXPATHLEN]; 586 587 n = snprintf(tmp, sizeof(tmp), "%s/%s", luserdir, luser); 588 if (n < 0 || (u_int)n >= sizeof(tmp)) { 589 syslog(LOG_ERR, "provided banned directory line too long (%s)", 590 luserdir); 591 return (0); 592 } 593 if ((f = fopen(tmp, "r")) == NULL) { 594 if (errno == ENOENT) { 595 /* 596 * file or dir doesn't exist, so therefore 597 * this luser isn't banned.. all is well 598 */ 599 return (1); 600 } else { 601 /* 602 * luser may in fact be banned, but we can't open the 603 * file even though it's there. probably a config 604 * problem. 605 */ 606 syslog(LOG_ERR, "cannot open banned file %s (%s)", 607 tmp, strerror(errno)); 608 return (0); 609 } 610 } else { 611 /* 612 * luser is banned - spit the file at them to 613 * tell what they can do and where they can go. 614 */ 615 syslog(LOG_INFO, "denied access to %s: %s exists", 616 luser, tmp); 617 618 /* reuse tmp */ 619 strlcpy(tmp, "\n\n-**- Sorry, you have been banned! -**-\n\n", 620 sizeof(tmp)); 621 while (fputs(tmp, stdout) != EOF && !feof(f)) { 622 if (fgets(tmp, sizeof(tmp), f) == NULL) { 623 fflush(stdout); 624 fclose(f); 625 return (0); 626 } 627 } 628 fclose(f); 629 } 630 fflush(stdout); 631 return (0); 632 } 633 634 /* 635 * Search for rulesets left by other authpf processes (either because they 636 * died ungracefully or were terminated) and remove them. 637 */ 638 static int 639 remove_stale_rulesets(void) 640 { 641 struct pfioc_ruleset prs; 642 u_int32_t nr; 643 644 memset(&prs, 0, sizeof(prs)); 645 strlcpy(prs.path, anchorname, sizeof(prs.path)); 646 if (ioctl(dev, DIOCGETRULESETS, &prs)) { 647 if (errno == EINVAL) 648 return (0); 649 else 650 return (1); 651 } 652 653 nr = prs.nr; 654 while (nr) { 655 char *s, *t; 656 pid_t pid; 657 658 prs.nr = nr - 1; 659 if (ioctl(dev, DIOCGETRULESET, &prs)) 660 return (1); 661 errno = 0; 662 if ((t = strchr(prs.name, '(')) == NULL) 663 t = prs.name; 664 else 665 t++; 666 pid = strtoul(t, &s, 10); 667 if (!prs.name[0] || errno || 668 (*s && (t == prs.name || *s != ')'))) 669 return (1); 670 if ((kill(pid, 0) && errno != EPERM) || pid == getpid()) { 671 if (recursive_ruleset_purge(anchorname, prs.name)) 672 return (1); 673 } 674 nr--; 675 } 676 return (0); 677 } 678 679 static int 680 recursive_ruleset_purge(char *an, char *rs) 681 { 682 struct pfioc_trans_e *t_e = NULL; 683 struct pfioc_trans *t = NULL; 684 struct pfioc_ruleset *prs = NULL; 685 686 /* purge rules */ 687 errno = 0; 688 if ((t = calloc(1, sizeof(struct pfioc_trans))) == NULL) 689 goto no_mem; 690 if ((t_e = calloc(2, sizeof(struct pfioc_trans_e))) == NULL) 691 goto no_mem; 692 t->size = 2; 693 t->esize = sizeof(struct pfioc_trans_e); 694 t->array = t_e; 695 t_e[0].type = PF_TRANS_RULESET; 696 snprintf(t_e[0].anchor, sizeof(t_e[0].anchor), "%s/%s", an, rs); 697 t_e[1].type = PF_TRANS_TABLE; 698 699 if ((ioctl(dev, DIOCXBEGIN, t) || 700 ioctl(dev, DIOCXCOMMIT, t)) && 701 errno != EINVAL) 702 goto cleanup; 703 704 /* purge any children */ 705 if ((prs = calloc(1, sizeof(struct pfioc_ruleset))) == NULL) 706 goto no_mem; 707 snprintf(prs->path, sizeof(prs->path), "%s/%s", an, rs); 708 if (ioctl(dev, DIOCGETRULESETS, prs)) { 709 if (errno != EINVAL) 710 goto cleanup; 711 errno = 0; 712 } else { 713 int nr = prs->nr; 714 715 while (nr) { 716 prs->nr = 0; 717 if (ioctl(dev, DIOCGETRULESET, prs)) 718 goto cleanup; 719 720 if (recursive_ruleset_purge(prs->path, prs->name)) 721 goto cleanup; 722 nr--; 723 } 724 } 725 726 no_mem: 727 if (errno == ENOMEM) 728 syslog(LOG_ERR, "calloc failed"); 729 730 cleanup: 731 free(t); 732 free(t_e); 733 free(prs); 734 return (errno); 735 } 736 737 /* 738 * Add/remove filter entries for user "luser" from ip "ipsrc" 739 */ 740 static int 741 change_filter(int add, const char *luser, const char *ipsrc) 742 { 743 char *fdpath = NULL, *userstr = NULL, *ipstr = NULL; 744 char *rsn = NULL, *fn = NULL; 745 pid_t pid; 746 gid_t gid; 747 int s; 748 749 if (add) { 750 struct stat sb; 751 struct group *grent; 752 char *pargv[13] = { 753 "pfctl", "-p", "/dev/pf", "-q", "-a", "anchor/ruleset", 754 "-D", "user_id=X", "-D", "user_ip=X", "-f", "file", NULL 755 }; 756 757 if((grent = getgrgid(getgid())) == NULL) { 758 syslog(LOG_ERR, "Group not found user %s, gid %d", 759 luser, getgid()); 760 } 761 762 if (luser == NULL || !luser[0] || ipsrc == NULL || !ipsrc[0]) { 763 syslog(LOG_ERR, "invalid luser/ipsrc"); 764 goto error; 765 } 766 767 if (asprintf(&rsn, "%s/%s", anchorname, rulesetname) == -1) 768 goto no_mem; 769 if (asprintf(&fdpath, "/dev/fd/%d", dev) == -1) 770 goto no_mem; 771 if (asprintf(&ipstr, "user_ip=%s", ipsrc) == -1) 772 goto no_mem; 773 if (asprintf(&userstr, "user_id=%s", luser) == -1) 774 goto no_mem; 775 if (asprintf(&fn, "%s/%s/authpf.rules", 776 PATH_USER_DIR, luser) == -1) 777 goto no_mem; 778 if (stat(fn, &sb) == -1) { 779 free(fn); 780 if(asprintf(&fn, "%s/%s/authpf.rules", PATH_GROUP_DIR, 781 grent->gr_name) == -1) 782 goto no_mem; 783 if(stat(fn, &sb) == -1) { 784 free(fn); 785 if ((fn = strdup(PATH_PFRULES)) == NULL) 786 goto no_mem; 787 } 788 } 789 pargv[2] = fdpath; 790 pargv[5] = rsn; 791 pargv[7] = userstr; 792 if (user_ip) { 793 pargv[9] = ipstr; 794 pargv[11] = fn; 795 } else { 796 pargv[8] = "-f"; 797 pargv[9] = fn; 798 pargv[10] = NULL; 799 } 800 801 switch (pid = fork()) { 802 case -1: 803 syslog(LOG_ERR, "fork failed"); 804 goto error; 805 case 0: 806 /* revoke group privs before exec */ 807 gid = getgid(); 808 if (setresgid(gid, gid, gid) == -1) { 809 err(1, "setregid"); 810 } 811 execvp(PATH_PFCTL, pargv); 812 warn("exec of %s failed", PATH_PFCTL); 813 _exit(1); 814 } 815 816 /* parent */ 817 waitpid(pid, &s, 0); 818 if (s != 0) { 819 syslog(LOG_ERR, "pfctl exited abnormally"); 820 goto error; 821 } 822 823 gettimeofday(&Tstart, NULL); 824 syslog(LOG_INFO, "allowing %s, user %s", ipsrc, luser); 825 } else { 826 remove_stale_rulesets(); 827 828 gettimeofday(&Tend, NULL); 829 syslog(LOG_INFO, "removed %s, user %s - duration %d seconds", 830 ipsrc, luser, (int)(Tend.tv_sec - Tstart.tv_sec)); 831 } 832 return (0); 833 no_mem: 834 syslog(LOG_ERR, "malloc failed"); 835 error: 836 free(fdpath); 837 free(rsn); 838 free(userstr); 839 free(ipstr); 840 free(fn); 841 return (-1); 842 } 843 844 /* 845 * Add/remove this IP from the "authpf_users" table. 846 */ 847 static int 848 change_table(int add, const char *ipsrc) 849 { 850 struct pfioc_table io; 851 struct pfr_addr addr; 852 853 bzero(&io, sizeof(io)); 854 strlcpy(io.pfrio_table.pfrt_name, tablename, 855 sizeof(io.pfrio_table.pfrt_name)); 856 io.pfrio_buffer = &addr; 857 io.pfrio_esize = sizeof(addr); 858 io.pfrio_size = 1; 859 860 bzero(&addr, sizeof(addr)); 861 if (ipsrc == NULL || !ipsrc[0]) 862 return (-1); 863 if (inet_pton(AF_INET, ipsrc, &addr.pfra_ip4addr) == 1) { 864 addr.pfra_af = AF_INET; 865 addr.pfra_net = 32; 866 } else if (inet_pton(AF_INET6, ipsrc, &addr.pfra_ip6addr) == 1) { 867 addr.pfra_af = AF_INET6; 868 addr.pfra_net = 128; 869 } else { 870 syslog(LOG_ERR, "invalid ipsrc"); 871 return (-1); 872 } 873 874 if (ioctl(dev, add ? DIOCRADDADDRS : DIOCRDELADDRS, &io) && 875 errno != ESRCH) { 876 syslog(LOG_ERR, "cannot %s %s from table %s: %s", 877 add ? "add" : "remove", ipsrc, tablename, 878 strerror(errno)); 879 return (-1); 880 } 881 return (0); 882 } 883 884 /* 885 * This is to kill off states that would otherwise be left behind stateful 886 * rules. This means we don't need to allow in more traffic than we really 887 * want to, since we don't have to worry about any luser sessions lasting 888 * longer than their ssh session. This function is based on 889 * pfctl_kill_states from pfctl. 890 */ 891 static void 892 authpf_kill_states(void) 893 { 894 struct pfioc_state_kill psk; 895 struct pf_addr target; 896 897 memset(&psk, 0, sizeof(psk)); 898 memset(&target, 0, sizeof(target)); 899 900 if (inet_pton(AF_INET, ipsrc, &target.v4) == 1) 901 psk.psk_af = AF_INET; 902 else if (inet_pton(AF_INET6, ipsrc, &target.v6) == 1) 903 psk.psk_af = AF_INET6; 904 else { 905 syslog(LOG_ERR, "inet_pton(%s) failed", ipsrc); 906 return; 907 } 908 909 /* Kill all states from ipsrc */ 910 memcpy(&psk.psk_src.addr.v.a.addr, &target, 911 sizeof(psk.psk_src.addr.v.a.addr)); 912 memset(&psk.psk_src.addr.v.a.mask, 0xff, 913 sizeof(psk.psk_src.addr.v.a.mask)); 914 if (ioctl(dev, DIOCKILLSTATES, &psk)) 915 syslog(LOG_ERR, "DIOCKILLSTATES failed (%m)"); 916 917 /* Kill all states to ipsrc */ 918 memset(&psk.psk_src, 0, sizeof(psk.psk_src)); 919 memcpy(&psk.psk_dst.addr.v.a.addr, &target, 920 sizeof(psk.psk_dst.addr.v.a.addr)); 921 memset(&psk.psk_dst.addr.v.a.mask, 0xff, 922 sizeof(psk.psk_dst.addr.v.a.mask)); 923 if (ioctl(dev, DIOCKILLSTATES, &psk)) 924 syslog(LOG_ERR, "DIOCKILLSTATES failed (%m)"); 925 } 926 927 /* signal handler that makes us go away properly */ 928 static void 929 need_death(int signo) 930 { 931 want_death = 1; 932 } 933 934 /* 935 * function that removes our stuff when we go away. 936 */ 937 static __dead void 938 do_death(int active) 939 { 940 int ret = 0; 941 942 if (active) { 943 change_filter(0, luser, ipsrc); 944 if (user_ip) { 945 change_table(0, ipsrc); 946 authpf_kill_states(); 947 } 948 } 949 if (pidfile[0] && pidfd != -1) 950 if (unlink(pidfile) == -1) 951 syslog(LOG_ERR, "cannot unlink %s (%m)", pidfile); 952 exit(ret); 953 } 954