1 /* $OpenBSD: authpf.c,v 1.123 2015/01/21 21:50:32 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 <netinet/in.h> 28 #include <arpa/inet.h> 29 #include <net/if.h> 30 #include <net/pfvar.h> 31 32 #include <err.h> 33 #include <errno.h> 34 #include <login_cap.h> 35 #include <pwd.h> 36 #include <grp.h> 37 #include <signal.h> 38 #include <stdio.h> 39 #include <stdlib.h> 40 #include <string.h> 41 #include <syslog.h> 42 #include <unistd.h> 43 44 #include "pathnames.h" 45 46 static int read_config(FILE *); 47 static void print_message(char *); 48 static int allowed_luser(struct passwd *); 49 static int check_luser(char *, char *); 50 static int remove_stale_rulesets(void); 51 static int recursive_ruleset_purge(char *, char *); 52 static int change_filter(int, const char *, const char *); 53 static int change_table(int, const char *); 54 static void authpf_kill_states(void); 55 56 int dev; /* pf device */ 57 char anchorname[PF_ANCHOR_NAME_SIZE] = "authpf"; 58 char rulesetname[PATH_MAX - PF_ANCHOR_NAME_SIZE - 2]; 59 char tablename[PF_TABLE_NAME_SIZE] = "authpf_users"; 60 int user_ip = 1; /* controls whether $user_ip is set */ 61 62 FILE *pidfp; 63 int pidfd = -1; 64 char luser[LOGIN_NAME_MAX]; /* username */ 65 char ipsrc[256]; /* ip as a string */ 66 char pidfile[PATH_MAX]; /* we save pid in this file. */ 67 68 struct timeval Tstart, Tend; /* start and end times of session */ 69 70 volatile sig_atomic_t want_death; 71 static void need_death(int signo); 72 static __dead void do_death(int); 73 extern char *__progname; /* program name */ 74 75 /* 76 * User shell for authenticating gateways. Sole purpose is to allow 77 * a user to ssh to a gateway, and have the gateway modify packet 78 * filters to allow access, then remove access when the user finishes 79 * up. Meant to be used only from ssh(1) connections. 80 */ 81 int 82 main(int argc, char *argv[]) 83 { 84 int lockcnt = 0, n; 85 FILE *config; 86 struct in6_addr ina; 87 struct passwd *pw; 88 char *cp; 89 gid_t gid; 90 uid_t uid; 91 char *shell; 92 login_cap_t *lc; 93 94 if (strcmp(__progname, "-authpf-noip") == 0) 95 user_ip = 0; 96 97 config = fopen(PATH_CONFFILE, "r"); 98 if (config == NULL) { 99 syslog(LOG_ERR, "cannot open %s (%m)", PATH_CONFFILE); 100 exit(1); 101 } 102 103 if ((cp = getenv("SSH_TTY")) == NULL) { 104 syslog(LOG_ERR, "non-interactive session connection for authpf"); 105 exit(1); 106 } 107 108 if ((cp = getenv("SSH_CLIENT")) == NULL) { 109 syslog(LOG_ERR, "cannot determine connection source"); 110 exit(1); 111 } 112 113 if (strlcpy(ipsrc, cp, sizeof(ipsrc)) >= sizeof(ipsrc)) { 114 syslog(LOG_ERR, "SSH_CLIENT variable too long"); 115 exit(1); 116 } 117 cp = strchr(ipsrc, ' '); 118 if (!cp) { 119 syslog(LOG_ERR, "corrupt SSH_CLIENT variable %s", ipsrc); 120 exit(1); 121 } 122 *cp = '\0'; 123 if (inet_pton(AF_INET, ipsrc, &ina) != 1 && 124 inet_pton(AF_INET6, ipsrc, &ina) != 1) { 125 syslog(LOG_ERR, 126 "cannot determine IP from SSH_CLIENT %s", ipsrc); 127 exit(1); 128 } 129 /* open the pf device */ 130 dev = open(PATH_DEVFILE, O_RDWR); 131 if (dev == -1) { 132 syslog(LOG_ERR, "cannot open packet filter device (%m)"); 133 goto die; 134 } 135 136 uid = getuid(); 137 pw = getpwuid(uid); 138 if (pw == NULL) { 139 syslog(LOG_ERR, "cannot find user for uid %u", uid); 140 goto die; 141 } 142 143 if ((lc = login_getclass(pw->pw_class)) != NULL) 144 shell = login_getcapstr(lc, "shell", pw->pw_shell, 145 pw->pw_shell); 146 else 147 shell = pw->pw_shell; 148 149 login_close(lc); 150 151 if (strcmp(shell, PATH_AUTHPF_SHELL) && 152 strcmp(shell, PATH_AUTHPF_SHELL_NOIP)) { 153 syslog(LOG_ERR, "wrong shell for user %s, uid %u", 154 pw->pw_name, pw->pw_uid); 155 if (shell != pw->pw_shell) 156 free(shell); 157 goto die; 158 } 159 160 if (shell != pw->pw_shell) 161 free(shell); 162 163 /* 164 * Paranoia, but this data _does_ come from outside authpf, and 165 * truncation would be bad. 166 */ 167 if (strlcpy(luser, pw->pw_name, sizeof(luser)) >= sizeof(luser)) { 168 syslog(LOG_ERR, "username too long: %s", pw->pw_name); 169 goto die; 170 } 171 172 if ((n = snprintf(rulesetname, sizeof(rulesetname), "%s(%ld)", 173 luser, (long)getpid())) < 0 || (u_int)n >= sizeof(rulesetname)) { 174 syslog(LOG_INFO, "%s(%ld) too large, ruleset name will be %ld", 175 luser, (long)getpid(), (long)getpid()); 176 if ((n = snprintf(rulesetname, sizeof(rulesetname), "%ld", 177 (long)getpid())) < 0 || (u_int)n >= sizeof(rulesetname)) { 178 syslog(LOG_ERR, "pid too large for ruleset name"); 179 goto die; 180 } 181 } 182 183 184 /* Make our entry in /var/authpf as ipaddr or username */ 185 n = snprintf(pidfile, sizeof(pidfile), "%s/%s", 186 PATH_PIDFILE, user_ip ? ipsrc : luser); 187 if (n < 0 || (u_int)n >= sizeof(pidfile)) { 188 syslog(LOG_ERR, "path to pidfile too long"); 189 goto die; 190 } 191 192 signal(SIGTERM, need_death); 193 signal(SIGINT, need_death); 194 signal(SIGALRM, need_death); 195 signal(SIGPIPE, need_death); 196 signal(SIGHUP, need_death); 197 signal(SIGQUIT, need_death); 198 signal(SIGTSTP, need_death); 199 200 /* 201 * If someone else is already using this ip, then this person 202 * wants to switch users - so kill the old process and exit 203 * as well. 204 * 205 * Note, we could print a message and tell them to log out, but the 206 * usual case of this is that someone has left themselves logged in, 207 * with the authenticated connection iconized and someone else walks 208 * up to use and automatically logs in before using. If this just 209 * gets rid of the old one silently, the new user never knows they 210 * could have used someone else's old authentication. If we 211 * tell them to log out before switching users it is an invitation 212 * for abuse. 213 */ 214 215 do { 216 int save_errno, otherpid = -1; 217 char otherluser[LOGIN_NAME_MAX]; 218 219 if ((pidfd = open(pidfile, O_RDWR|O_CREAT, 0644)) == -1 || 220 (pidfp = fdopen(pidfd, "r+")) == NULL) { 221 if (pidfd != -1) 222 close(pidfd); 223 syslog(LOG_ERR, "cannot open or create %s: %s", pidfile, 224 strerror(errno)); 225 goto die; 226 } 227 228 if (flock(fileno(pidfp), LOCK_EX|LOCK_NB) == 0) 229 break; 230 save_errno = errno; 231 232 /* Mark our pid, and username to our file. */ 233 234 rewind(pidfp); 235 /* 31 == MAXLOGNAME - 1 */ 236 if (fscanf(pidfp, "%d\n%31s\n", &otherpid, otherluser) != 2) 237 otherpid = -1; 238 syslog(LOG_DEBUG, "tried to lock %s, in use by pid %d: %s", 239 pidfile, otherpid, strerror(save_errno)); 240 241 if (otherpid > 0) { 242 syslog(LOG_INFO, 243 "killing prior auth (pid %d) of %s by user %s", 244 otherpid, ipsrc, otherluser); 245 if (kill((pid_t) otherpid, SIGTERM) == -1) { 246 syslog(LOG_INFO, 247 "could not kill process %d: (%m)", 248 otherpid); 249 } 250 } 251 252 /* 253 * We try to kill the previous process and acquire the lock 254 * for 10 seconds, trying once a second. if we can't after 255 * 10 attempts we log an error and give up. 256 */ 257 if (want_death || ++lockcnt > 10) { 258 if (!want_death) 259 syslog(LOG_ERR, "cannot kill previous authpf (pid %d)", 260 otherpid); 261 fclose(pidfp); 262 pidfp = NULL; 263 pidfd = -1; 264 goto dogdeath; 265 } 266 sleep(1); 267 268 /* re-open, and try again. The previous authpf process 269 * we killed above should unlink the file and release 270 * it's lock, giving us a chance to get it now 271 */ 272 fclose(pidfp); 273 pidfp = NULL; 274 pidfd = -1; 275 } while (1); 276 277 /* whack the group list */ 278 gid = getegid(); 279 if (setgroups(1, &gid) == -1) { 280 syslog(LOG_INFO, "setgroups: %s", strerror(errno)); 281 do_death(0); 282 } 283 284 /* revoke privs */ 285 uid = getuid(); 286 if (setresuid(uid, uid, uid) == -1) { 287 syslog(LOG_INFO, "setresuid: %s", strerror(errno)); 288 do_death(0); 289 } 290 openlog("authpf", LOG_PID | LOG_NDELAY, LOG_DAEMON); 291 292 if (!check_luser(PATH_BAN_DIR, luser) || !allowed_luser(pw)) { 293 syslog(LOG_INFO, "user %s prohibited", luser); 294 do_death(0); 295 } 296 297 if (read_config(config)) { 298 syslog(LOG_ERR, "invalid config file %s", PATH_CONFFILE); 299 do_death(0); 300 } 301 302 if (remove_stale_rulesets()) { 303 syslog(LOG_INFO, "error removing stale rulesets"); 304 do_death(0); 305 } 306 307 /* We appear to be making headway, so actually mark our pid */ 308 rewind(pidfp); 309 fprintf(pidfp, "%ld\n%s\n", (long)getpid(), luser); 310 fflush(pidfp); 311 (void) ftruncate(fileno(pidfp), ftello(pidfp)); 312 313 if (change_filter(1, luser, ipsrc) == -1) { 314 printf("Unable to modify filters\r\n"); 315 do_death(0); 316 } 317 if (user_ip && change_table(1, ipsrc) == -1) { 318 printf("Unable to modify table\r\n"); 319 change_filter(0, luser, ipsrc); 320 do_death(0); 321 } 322 323 while (1) { 324 struct stat sb; 325 char *path_message; 326 printf("\r\nHello %s. ", luser); 327 printf("You are authenticated from host \"%s\"\r\n", ipsrc); 328 setproctitle("%s@%s", luser, ipsrc); 329 if (asprintf(&path_message, "%s/%s/authpf.message", 330 PATH_USER_DIR, luser) == -1) 331 do_death(1); 332 if (stat(path_message, &sb) == -1 || ! S_ISREG(sb.st_mode)) { 333 free(path_message); 334 if ((path_message = strdup(PATH_MESSAGE)) == NULL) 335 do_death(1); 336 } 337 print_message(path_message); 338 while (1) { 339 sleep(10); 340 if (want_death) 341 do_death(1); 342 } 343 } 344 345 /* NOTREACHED */ 346 dogdeath: 347 printf("\r\n\r\nSorry, this service is currently unavailable due to "); 348 printf("technical difficulties\r\n\r\n"); 349 print_message(PATH_PROBLEM); 350 printf("\r\nYour authentication process (pid %ld) was unable to run\n", 351 (long)getpid()); 352 sleep(180); /* them lusers read reaaaaal slow */ 353 die: 354 do_death(0); 355 } 356 357 /* 358 * reads config file in PATH_CONFFILE to set optional behaviours up 359 */ 360 static int 361 read_config(FILE *f) 362 { 363 char buf[1024]; 364 int i = 0; 365 366 do { 367 char **ap; 368 char *pair[4], *cp, *tp; 369 int len; 370 371 if (fgets(buf, sizeof(buf), f) == NULL) { 372 fclose(f); 373 return (0); 374 } 375 i++; 376 len = strlen(buf); 377 if (len == 0) 378 continue; 379 if (buf[len - 1] != '\n' && !feof(f)) { 380 syslog(LOG_ERR, "line %d too long in %s", i, 381 PATH_CONFFILE); 382 return (1); 383 } 384 buf[len - 1] = '\0'; 385 386 for (cp = buf; *cp == ' ' || *cp == '\t'; cp++) 387 ; /* nothing */ 388 389 if (!*cp || *cp == '#' || *cp == '\n') 390 continue; 391 392 for (ap = pair; ap < &pair[3] && 393 (*ap = strsep(&cp, "=")) != NULL; ) { 394 if (**ap != '\0') 395 ap++; 396 } 397 if (ap != &pair[2]) 398 goto parse_error; 399 400 tp = pair[1] + strlen(pair[1]); 401 while ((*tp == ' ' || *tp == '\t') && tp >= pair[1]) 402 *tp-- = '\0'; 403 404 if (strcasecmp(pair[0], "anchor") == 0) { 405 if (!pair[1][0] || strlcpy(anchorname, pair[1], 406 sizeof(anchorname)) >= sizeof(anchorname)) 407 goto parse_error; 408 } 409 if (strcasecmp(pair[0], "table") == 0) { 410 if (!pair[1][0] || strlcpy(tablename, pair[1], 411 sizeof(tablename)) >= sizeof(tablename)) 412 goto parse_error; 413 } 414 } while (!feof(f) && !ferror(f)); 415 fclose(f); 416 return (0); 417 418 parse_error: 419 fclose(f); 420 syslog(LOG_ERR, "parse error, line %d of %s", i, PATH_CONFFILE); 421 return (1); 422 } 423 424 425 /* 426 * splatter a file to stdout - max line length of 1024, 427 * used for spitting message files at users to tell them 428 * they've been bad or we're unavailable. 429 */ 430 static void 431 print_message(char *filename) 432 { 433 char buf[1024]; 434 FILE *f; 435 436 if ((f = fopen(filename, "r")) == NULL) 437 return; /* fail silently, we don't care if it isn't there */ 438 439 do { 440 if (fgets(buf, sizeof(buf), f) == NULL) { 441 fflush(stdout); 442 fclose(f); 443 return; 444 } 445 } while (fputs(buf, stdout) != EOF && !feof(f)); 446 fflush(stdout); 447 fclose(f); 448 } 449 450 /* 451 * allowed_luser checks to see if user "luser" is allowed to 452 * use this gateway by virtue of being listed in an allowed 453 * users file, namely /etc/authpf/authpf.allow . 454 * Users may be listed by <username>, %<group>, or @<login_class>. 455 * 456 * If /etc/authpf/authpf.allow does not exist, then we assume that 457 * all users who are allowed in by sshd(8) are permitted to 458 * use this gateway. If /etc/authpf/authpf.allow does exist, then a 459 * user must be listed if the connection is to continue, else 460 * the session terminates in the same manner as being banned. 461 */ 462 static int 463 allowed_luser(struct passwd *pw) 464 { 465 char *buf, *lbuf; 466 int matched; 467 size_t len; 468 FILE *f; 469 470 if ((f = fopen(PATH_ALLOWFILE, "r")) == NULL) { 471 if (errno == ENOENT) { 472 /* 473 * allowfile doesn't exist, thus this gateway 474 * isn't restricted to certain users... 475 */ 476 return (1); 477 } 478 479 /* 480 * luser may in fact be allowed, but we can't open 481 * the file even though it's there. probably a config 482 * problem. 483 */ 484 syslog(LOG_ERR, "cannot open allowed users file %s (%s)", 485 PATH_ALLOWFILE, strerror(errno)); 486 return (0); 487 } else { 488 /* 489 * /etc/authpf/authpf.allow exists, thus we do a linear 490 * search to see if they are allowed. 491 * also, if username "*" exists, then this is a 492 * "public" gateway, such as it is, so let 493 * everyone use it. 494 */ 495 int gl_init = 0, ngroups = NGROUPS_MAX + 1; 496 gid_t groups[NGROUPS_MAX + 1]; 497 498 lbuf = NULL; 499 matched = 0; 500 501 while ((buf = fgetln(f, &len))) { 502 503 if (buf[len - 1] == '\n') 504 buf[len - 1] = '\0'; 505 else { 506 if ((lbuf = malloc(len + 1)) == NULL) 507 err(1, NULL); 508 memcpy(lbuf, buf, len); 509 lbuf[len] = '\0'; 510 buf = lbuf; 511 } 512 513 if (buf[0] == '@') { 514 /* check login class */ 515 if (strcmp(pw->pw_class, buf + 1) == 0) 516 matched++; 517 } else if (buf[0] == '%') { 518 /* check group membership */ 519 int cnt; 520 struct group *group; 521 522 if ((group = getgrnam(buf + 1)) == NULL) { 523 syslog(LOG_ERR, 524 "invalid group '%s' in %s (%s)", 525 buf + 1, PATH_ALLOWFILE, 526 strerror(errno)); 527 fclose(f); 528 return (0); 529 } 530 531 if (!gl_init) { 532 (void) getgrouplist(pw->pw_name, 533 pw->pw_gid, groups, &ngroups); 534 gl_init++; 535 } 536 537 for ( cnt = 0; cnt < ngroups; cnt++) { 538 if (group->gr_gid == groups[cnt]) { 539 matched++; 540 break; 541 } 542 } 543 } else { 544 /* check username and wildcard */ 545 matched = strcmp(pw->pw_name, buf) == 0 || 546 strcmp("*", buf) == 0; 547 } 548 549 if (lbuf != NULL) { 550 free(lbuf); 551 lbuf = NULL; 552 } 553 554 if (matched) { 555 fclose(f); 556 return (1); /* matched an allowed user/group */ 557 } 558 } 559 syslog(LOG_INFO, "denied access to %s: not listed in %s", 560 pw->pw_name, PATH_ALLOWFILE); 561 562 /* reuse buf */ 563 buf = "\n\nSorry, you are not allowed to use this facility!\n"; 564 fputs(buf, stdout); 565 } 566 fflush(stdout); 567 fclose(f); 568 return (0); 569 } 570 571 /* 572 * check_luser checks to see if user "luser" has been banned 573 * from using us by virtue of having an file of the same name 574 * in the "luserdir" directory. 575 * 576 * If the user has been banned, we copy the contents of the file 577 * to the user's screen. (useful for telling the user what to 578 * do to get un-banned, or just to tell them they aren't 579 * going to be un-banned.) 580 */ 581 static int 582 check_luser(char *luserdir, char *luser) 583 { 584 FILE *f; 585 int n; 586 char tmp[PATH_MAX]; 587 588 n = snprintf(tmp, sizeof(tmp), "%s/%s", luserdir, luser); 589 if (n < 0 || (u_int)n >= sizeof(tmp)) { 590 syslog(LOG_ERR, "provided banned directory line too long (%s)", 591 luserdir); 592 return (0); 593 } 594 if ((f = fopen(tmp, "r")) == NULL) { 595 if (errno == ENOENT) { 596 /* 597 * file or dir doesn't exist, so therefore 598 * this luser isn't banned.. all is well 599 */ 600 return (1); 601 } else { 602 /* 603 * luser may in fact be banned, but we can't open the 604 * file even though it's there. probably a config 605 * problem. 606 */ 607 syslog(LOG_ERR, "cannot open banned file %s (%s)", 608 tmp, strerror(errno)); 609 return (0); 610 } 611 } else { 612 /* 613 * luser is banned - spit the file at them to 614 * tell what they can do and where they can go. 615 */ 616 syslog(LOG_INFO, "denied access to %s: %s exists", 617 luser, tmp); 618 619 /* reuse tmp */ 620 strlcpy(tmp, "\n\n-**- Sorry, you have been banned! -**-\n\n", 621 sizeof(tmp)); 622 while (fputs(tmp, stdout) != EOF && !feof(f)) { 623 if (fgets(tmp, sizeof(tmp), f) == NULL) { 624 fflush(stdout); 625 fclose(f); 626 return (0); 627 } 628 } 629 fclose(f); 630 } 631 fflush(stdout); 632 return (0); 633 } 634 635 /* 636 * Search for rulesets left by other authpf processes (either because they 637 * died ungracefully or were terminated) and remove them. 638 */ 639 static int 640 remove_stale_rulesets(void) 641 { 642 struct pfioc_ruleset prs; 643 u_int32_t nr; 644 645 memset(&prs, 0, sizeof(prs)); 646 strlcpy(prs.path, anchorname, sizeof(prs.path)); 647 if (ioctl(dev, DIOCGETRULESETS, &prs)) { 648 if (errno == EINVAL) 649 return (0); 650 else 651 return (1); 652 } 653 654 nr = prs.nr; 655 while (nr) { 656 char *s, *t; 657 pid_t pid; 658 659 prs.nr = nr - 1; 660 if (ioctl(dev, DIOCGETRULESET, &prs)) 661 return (1); 662 errno = 0; 663 if ((t = strchr(prs.name, '(')) == NULL) 664 t = prs.name; 665 else 666 t++; 667 pid = strtoul(t, &s, 10); 668 if (!prs.name[0] || errno || 669 (*s && (t == prs.name || *s != ')'))) 670 return (1); 671 if ((kill(pid, 0) && errno != EPERM) || pid == getpid()) { 672 if (recursive_ruleset_purge(anchorname, prs.name)) 673 return (1); 674 } 675 nr--; 676 } 677 return (0); 678 } 679 680 static int 681 recursive_ruleset_purge(char *an, char *rs) 682 { 683 struct pfioc_trans_e *t_e = NULL; 684 struct pfioc_trans *t = NULL; 685 struct pfioc_ruleset *prs = NULL; 686 687 /* purge rules */ 688 errno = 0; 689 if ((t = calloc(1, sizeof(struct pfioc_trans))) == NULL) 690 goto no_mem; 691 if ((t_e = calloc(2, sizeof(struct pfioc_trans_e))) == NULL) 692 goto no_mem; 693 t->size = 2; 694 t->esize = sizeof(struct pfioc_trans_e); 695 t->array = t_e; 696 t_e[0].type = PF_TRANS_RULESET; 697 snprintf(t_e[0].anchor, sizeof(t_e[0].anchor), "%s/%s", an, rs); 698 t_e[1].type = PF_TRANS_TABLE; 699 700 if ((ioctl(dev, DIOCXBEGIN, t) || 701 ioctl(dev, DIOCXCOMMIT, t)) && 702 errno != EINVAL) 703 goto cleanup; 704 705 /* purge any children */ 706 if ((prs = calloc(1, sizeof(struct pfioc_ruleset))) == NULL) 707 goto no_mem; 708 snprintf(prs->path, sizeof(prs->path), "%s/%s", an, rs); 709 if (ioctl(dev, DIOCGETRULESETS, prs)) { 710 if (errno != EINVAL) 711 goto cleanup; 712 errno = 0; 713 } else { 714 int nr = prs->nr; 715 716 while (nr) { 717 prs->nr = 0; 718 if (ioctl(dev, DIOCGETRULESET, prs)) 719 goto cleanup; 720 721 if (recursive_ruleset_purge(prs->path, prs->name)) 722 goto cleanup; 723 nr--; 724 } 725 } 726 727 no_mem: 728 if (errno == ENOMEM) 729 syslog(LOG_ERR, "calloc failed"); 730 731 cleanup: 732 free(t); 733 free(t_e); 734 free(prs); 735 return (errno); 736 } 737 738 /* 739 * Add/remove filter entries for user "luser" from ip "ipsrc" 740 */ 741 static int 742 change_filter(int add, const char *luser, const char *ipsrc) 743 { 744 char *fdpath = NULL, *userstr = NULL, *ipstr = NULL; 745 char *rsn = NULL, *fn = NULL; 746 pid_t pid; 747 gid_t gid; 748 int s; 749 750 if (add) { 751 struct stat sb; 752 struct group *grent; 753 char *pargv[13] = { 754 "pfctl", "-p", "/dev/pf", "-q", "-a", "anchor/ruleset", 755 "-D", "user_id=X", "-D", "user_ip=X", "-f", "file", NULL 756 }; 757 758 if((grent = getgrgid(getgid())) == NULL) { 759 syslog(LOG_ERR, "Group not found user %s, gid %d", 760 luser, getgid()); 761 } 762 763 if (luser == NULL || !luser[0] || ipsrc == NULL || !ipsrc[0]) { 764 syslog(LOG_ERR, "invalid luser/ipsrc"); 765 goto error; 766 } 767 768 if (asprintf(&rsn, "%s/%s", anchorname, rulesetname) == -1) 769 goto no_mem; 770 if (asprintf(&fdpath, "/dev/fd/%d", dev) == -1) 771 goto no_mem; 772 if (asprintf(&ipstr, "user_ip=%s", ipsrc) == -1) 773 goto no_mem; 774 if (asprintf(&userstr, "user_id=%s", luser) == -1) 775 goto no_mem; 776 if (asprintf(&fn, "%s/%s/authpf.rules", 777 PATH_USER_DIR, luser) == -1) 778 goto no_mem; 779 if (stat(fn, &sb) == -1) { 780 free(fn); 781 if(asprintf(&fn, "%s/%s/authpf.rules", PATH_GROUP_DIR, 782 grent->gr_name) == -1) 783 goto no_mem; 784 if(stat(fn, &sb) == -1) { 785 free(fn); 786 if ((fn = strdup(PATH_PFRULES)) == NULL) 787 goto no_mem; 788 } 789 } 790 pargv[2] = fdpath; 791 pargv[5] = rsn; 792 pargv[7] = userstr; 793 if (user_ip) { 794 pargv[9] = ipstr; 795 pargv[11] = fn; 796 } else { 797 pargv[8] = "-f"; 798 pargv[9] = fn; 799 pargv[10] = NULL; 800 } 801 802 switch (pid = fork()) { 803 case -1: 804 syslog(LOG_ERR, "fork failed"); 805 goto error; 806 case 0: 807 /* revoke group privs before exec */ 808 gid = getgid(); 809 if (setresgid(gid, gid, gid) == -1) { 810 err(1, "setregid"); 811 } 812 execvp(PATH_PFCTL, pargv); 813 warn("exec of %s failed", PATH_PFCTL); 814 _exit(1); 815 } 816 817 /* parent */ 818 waitpid(pid, &s, 0); 819 if (s != 0) { 820 syslog(LOG_ERR, "pfctl exited abnormally"); 821 goto error; 822 } 823 824 gettimeofday(&Tstart, NULL); 825 syslog(LOG_INFO, "allowing %s, user %s", ipsrc, luser); 826 } else { 827 remove_stale_rulesets(); 828 829 gettimeofday(&Tend, NULL); 830 syslog(LOG_INFO, "removed %s, user %s - duration %d seconds", 831 ipsrc, luser, (int)(Tend.tv_sec - Tstart.tv_sec)); 832 } 833 return (0); 834 no_mem: 835 syslog(LOG_ERR, "malloc failed"); 836 error: 837 free(fdpath); 838 free(rsn); 839 free(userstr); 840 free(ipstr); 841 free(fn); 842 return (-1); 843 } 844 845 /* 846 * Add/remove this IP from the "authpf_users" table. 847 */ 848 static int 849 change_table(int add, const char *ipsrc) 850 { 851 struct pfioc_table io; 852 struct pfr_addr addr; 853 854 bzero(&io, sizeof(io)); 855 strlcpy(io.pfrio_table.pfrt_name, tablename, 856 sizeof(io.pfrio_table.pfrt_name)); 857 io.pfrio_buffer = &addr; 858 io.pfrio_esize = sizeof(addr); 859 io.pfrio_size = 1; 860 861 bzero(&addr, sizeof(addr)); 862 if (ipsrc == NULL || !ipsrc[0]) 863 return (-1); 864 if (inet_pton(AF_INET, ipsrc, &addr.pfra_ip4addr) == 1) { 865 addr.pfra_af = AF_INET; 866 addr.pfra_net = 32; 867 } else if (inet_pton(AF_INET6, ipsrc, &addr.pfra_ip6addr) == 1) { 868 addr.pfra_af = AF_INET6; 869 addr.pfra_net = 128; 870 } else { 871 syslog(LOG_ERR, "invalid ipsrc"); 872 return (-1); 873 } 874 875 if (ioctl(dev, add ? DIOCRADDADDRS : DIOCRDELADDRS, &io) && 876 errno != ESRCH) { 877 syslog(LOG_ERR, "cannot %s %s from table %s: %s", 878 add ? "add" : "remove", ipsrc, tablename, 879 strerror(errno)); 880 return (-1); 881 } 882 return (0); 883 } 884 885 /* 886 * This is to kill off states that would otherwise be left behind stateful 887 * rules. This means we don't need to allow in more traffic than we really 888 * want to, since we don't have to worry about any luser sessions lasting 889 * longer than their ssh session. This function is based on 890 * pfctl_kill_states from pfctl. 891 */ 892 static void 893 authpf_kill_states(void) 894 { 895 struct pfioc_state_kill psk; 896 struct pf_addr target; 897 898 memset(&psk, 0, sizeof(psk)); 899 memset(&target, 0, sizeof(target)); 900 901 if (inet_pton(AF_INET, ipsrc, &target.v4) == 1) 902 psk.psk_af = AF_INET; 903 else if (inet_pton(AF_INET6, ipsrc, &target.v6) == 1) 904 psk.psk_af = AF_INET6; 905 else { 906 syslog(LOG_ERR, "inet_pton(%s) failed", ipsrc); 907 return; 908 } 909 910 /* Kill all states from ipsrc */ 911 memcpy(&psk.psk_src.addr.v.a.addr, &target, 912 sizeof(psk.psk_src.addr.v.a.addr)); 913 memset(&psk.psk_src.addr.v.a.mask, 0xff, 914 sizeof(psk.psk_src.addr.v.a.mask)); 915 if (ioctl(dev, DIOCKILLSTATES, &psk)) 916 syslog(LOG_ERR, "DIOCKILLSTATES failed (%m)"); 917 918 /* Kill all states to ipsrc */ 919 memset(&psk.psk_src, 0, sizeof(psk.psk_src)); 920 memcpy(&psk.psk_dst.addr.v.a.addr, &target, 921 sizeof(psk.psk_dst.addr.v.a.addr)); 922 memset(&psk.psk_dst.addr.v.a.mask, 0xff, 923 sizeof(psk.psk_dst.addr.v.a.mask)); 924 if (ioctl(dev, DIOCKILLSTATES, &psk)) 925 syslog(LOG_ERR, "DIOCKILLSTATES failed (%m)"); 926 } 927 928 /* signal handler that makes us go away properly */ 929 static void 930 need_death(int signo) 931 { 932 want_death = 1; 933 } 934 935 /* 936 * function that removes our stuff when we go away. 937 */ 938 static __dead void 939 do_death(int active) 940 { 941 int ret = 0; 942 943 if (active) { 944 change_filter(0, luser, ipsrc); 945 if (user_ip) { 946 change_table(0, ipsrc); 947 authpf_kill_states(); 948 } 949 } 950 if (pidfile[0] && pidfd != -1) 951 if (unlink(pidfile) == -1) 952 syslog(LOG_ERR, "cannot unlink %s (%m)", pidfile); 953 exit(ret); 954 } 955