1 /* $OpenBSD: authpf.c,v 1.112 2009/01/10 19:08:53 miod 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 * $FreeBSD: head/contrib/pf/authpf/authpf.c 223637 2011-06-28 11:57:25Z bz $ 19 */ 20 21 #include <sys/param.h> 22 #include <sys/types.h> 23 #include <sys/file.h> 24 #include <sys/ioctl.h> 25 #include <sys/socket.h> 26 #include <sys/stat.h> 27 #include <sys/time.h> 28 #include <sys/wait.h> 29 30 #include <net/if.h> 31 #include <net/pf/pfvar.h> 32 #include <arpa/inet.h> 33 34 #include <err.h> 35 #include <errno.h> 36 #include <login_cap.h> 37 #include <pwd.h> 38 #include <signal.h> 39 #include <stdio.h> 40 #include <stdlib.h> 41 #include <string.h> 42 #include <syslog.h> 43 #include <unistd.h> 44 45 #include "pathnames.h" 46 47 #define __dead __dead2 48 49 static int read_config(FILE *); 50 static void print_message(const char *); 51 static int allowed_luser(const char *); 52 static int check_luser(const char *, const char *); 53 static int remove_stale_rulesets(void); 54 static int change_filter(int, const char *, const char *); 55 static int change_table(int, const char *); 56 static void authpf_kill_states(void); 57 58 int dev_fd; /* pf device */ 59 char anchorname[PF_ANCHOR_NAME_SIZE] = "authpf"; 60 char rulesetname[MAXPATHLEN - PF_ANCHOR_NAME_SIZE - 2]; 61 char tablename[PF_TABLE_NAME_SIZE] = "authpf_users"; 62 63 FILE *pidfp; 64 char luser[MAXLOGNAME]; /* username */ 65 char ipsrc[256]; /* ip as a string */ 66 char pidfile[MAXPATHLEN]; /* 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 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 __unused, char **argv __unused) 82 { 83 int lockcnt = 0, n, pidfd; 84 FILE *config; 85 struct in6_addr ina; 86 struct passwd *pw; 87 char *cp; 88 gid_t gid; 89 uid_t uid; 90 const char *shell; 91 login_cap_t *lc; 92 93 config = fopen(PATH_CONFFILE, "r"); 94 if (config == NULL) { 95 syslog(LOG_ERR, "cannot open %s (%m)", PATH_CONFFILE); 96 exit(1); 97 } 98 99 if ((cp = getenv("SSH_TTY")) == NULL) { 100 syslog(LOG_ERR, "non-interactive session connection for authpf"); 101 exit(1); 102 } 103 104 if ((cp = getenv("SSH_CLIENT")) == NULL) { 105 syslog(LOG_ERR, "cannot determine connection source"); 106 exit(1); 107 } 108 109 if (strlcpy(ipsrc, cp, sizeof(ipsrc)) >= sizeof(ipsrc)) { 110 syslog(LOG_ERR, "SSH_CLIENT variable too long"); 111 exit(1); 112 } 113 cp = strchr(ipsrc, ' '); 114 if (!cp) { 115 syslog(LOG_ERR, "corrupt SSH_CLIENT variable %s", ipsrc); 116 exit(1); 117 } 118 *cp = '\0'; 119 if (inet_pton(AF_INET, ipsrc, &ina) != 1 && 120 inet_pton(AF_INET6, ipsrc, &ina) != 1) { 121 syslog(LOG_ERR, 122 "cannot determine IP from SSH_CLIENT %s", ipsrc); 123 exit(1); 124 } 125 /* open the pf device */ 126 dev_fd = open(PATH_DEVFILE, O_RDWR); 127 if (dev_fd == -1) { 128 syslog(LOG_ERR, "cannot open packet filter device (%m)"); 129 goto die; 130 } 131 132 uid = getuid(); 133 pw = getpwuid(uid); 134 if (pw == NULL) { 135 syslog(LOG_ERR, "cannot find user for uid %u", uid); 136 goto die; 137 } 138 139 if ((lc = login_getclass(pw->pw_class)) != NULL) 140 shell = login_getcapstr(lc, "shell", pw->pw_shell, 141 pw->pw_shell); 142 else 143 shell = pw->pw_shell; 144 145 146 147 if (strcmp(shell, PATH_AUTHPF_SHELL)) { 148 syslog(LOG_ERR, "wrong shell for user %s, uid %u", 149 pw->pw_name, pw->pw_uid); 150 login_close(lc); 151 goto die; 152 } 153 154 login_close(lc); 155 156 /* 157 * Paranoia, but this data _does_ come from outside authpf, and 158 * truncation would be bad. 159 */ 160 if (strlcpy(luser, pw->pw_name, sizeof(luser)) >= sizeof(luser)) { 161 syslog(LOG_ERR, "username too long: %s", pw->pw_name); 162 goto die; 163 } 164 165 if ((n = snprintf(rulesetname, sizeof(rulesetname), "%s(%ld)", 166 luser, (long)getpid())) < 0 || (u_int)n >= sizeof(rulesetname)) { 167 syslog(LOG_INFO, "%s(%ld) too large, ruleset name will be %ld", 168 luser, (long)getpid(), (long)getpid()); 169 if ((n = snprintf(rulesetname, sizeof(rulesetname), "%ld", 170 (long)getpid())) < 0 || (u_int)n >= sizeof(rulesetname)) { 171 syslog(LOG_ERR, "pid too large for ruleset name"); 172 goto die; 173 } 174 } 175 176 177 /* Make our entry in /var/authpf as /var/authpf/ipaddr */ 178 n = snprintf(pidfile, sizeof(pidfile), "%s/%s", PATH_PIDFILE, ipsrc); 179 if (n < 0 || (u_int)n >= sizeof(pidfile)) { 180 syslog(LOG_ERR, "path to pidfile too long"); 181 goto die; 182 } 183 184 /* 185 * If someone else is already using this ip, then this person 186 * wants to switch users - so kill the old process and exit 187 * as well. 188 * 189 * Note, we could print a message and tell them to log out, but the 190 * usual case of this is that someone has left themselves logged in, 191 * with the authenticated connection iconized and someone else walks 192 * up to use and automatically logs in before using. If this just 193 * gets rid of the old one silently, the new user never knows they 194 * could have used someone else's old authentication. If we 195 * tell them to log out before switching users it is an invitation 196 * for abuse. 197 */ 198 199 do { 200 int save_errno, otherpid = -1; 201 char otherluser[MAXLOGNAME]; 202 203 if ((pidfd = open(pidfile, O_RDWR|O_CREAT, 0644)) == -1 || 204 (pidfp = fdopen(pidfd, "r+")) == NULL) { 205 if (pidfd != -1) 206 close(pidfd); 207 syslog(LOG_ERR, "cannot open or create %s: %s", pidfile, 208 strerror(errno)); 209 goto die; 210 } 211 212 if (flock(fileno(pidfp), LOCK_EX|LOCK_NB) == 0) 213 break; 214 save_errno = errno; 215 216 /* Mark our pid, and username to our file. */ 217 218 rewind(pidfp); 219 /* 31 == MAXLOGNAME - 1 */ 220 if (fscanf(pidfp, "%d\n%31s\n", &otherpid, otherluser) != 2) 221 otherpid = -1; 222 syslog(LOG_DEBUG, "tried to lock %s, in use by pid %d: %s", 223 pidfile, otherpid, strerror(save_errno)); 224 225 if (otherpid > 0) { 226 syslog(LOG_INFO, 227 "killing prior auth (pid %d) of %s by user %s", 228 otherpid, ipsrc, otherluser); 229 if (kill((pid_t) otherpid, SIGTERM) == -1) { 230 syslog(LOG_INFO, 231 "could not kill process %d: (%m)", 232 otherpid); 233 } 234 } 235 236 /* 237 * We try to kill the previous process and acquire the lock 238 * for 10 seconds, trying once a second. if we can't after 239 * 10 attempts we log an error and give up. 240 */ 241 if (++lockcnt > 10) { 242 syslog(LOG_ERR, "cannot kill previous authpf (pid %d)", 243 otherpid); 244 fclose(pidfp); 245 pidfp = NULL; 246 goto dogdeath; 247 } 248 sleep(1); 249 250 /* re-open, and try again. The previous authpf process 251 * we killed above should unlink the file and release 252 * it's lock, giving us a chance to get it now 253 */ 254 fclose(pidfp); 255 pidfp = NULL; 256 } while (1); 257 258 /* whack the group list */ 259 gid = getegid(); 260 if (setgroups(1, &gid) == -1) { 261 syslog(LOG_INFO, "setgroups: %s", strerror(errno)); 262 do_death(0); 263 } 264 265 /* revoke privs */ 266 uid = getuid(); 267 if (setresuid(uid, uid, uid) == -1) { 268 syslog(LOG_INFO, "setresuid: %s", strerror(errno)); 269 do_death(0); 270 } 271 openlog("authpf", LOG_PID | LOG_NDELAY, LOG_DAEMON); 272 273 if (!check_luser(PATH_BAN_DIR, luser) || !allowed_luser(luser)) { 274 syslog(LOG_INFO, "user %s prohibited", luser); 275 do_death(0); 276 } 277 278 if (read_config(config)) { 279 syslog(LOG_ERR, "invalid config file %s", PATH_CONFFILE); 280 do_death(0); 281 } 282 283 if (remove_stale_rulesets()) { 284 syslog(LOG_INFO, "error removing stale rulesets"); 285 do_death(0); 286 } 287 288 /* We appear to be making headway, so actually mark our pid */ 289 rewind(pidfp); 290 fprintf(pidfp, "%ld\n%s\n", (long)getpid(), luser); 291 fflush(pidfp); 292 ftruncate(fileno(pidfp), ftell(pidfp)); 293 294 if (change_filter(1, luser, ipsrc) == -1) { 295 printf("Unable to modify filters\r\n"); 296 do_death(0); 297 } 298 if (change_table(1, ipsrc) == -1) { 299 printf("Unable to modify table\r\n"); 300 change_filter(0, luser, ipsrc); 301 do_death(0); 302 } 303 304 signal(SIGTERM, need_death); 305 signal(SIGINT, need_death); 306 signal(SIGALRM, need_death); 307 signal(SIGPIPE, need_death); 308 signal(SIGHUP, need_death); 309 signal(SIGQUIT, need_death); 310 signal(SIGTSTP, need_death); 311 while (1) { 312 printf("\r\nHello %s. ", luser); 313 printf("You are authenticated from host \"%s\"\r\n", ipsrc); 314 setproctitle("%s@%s", luser, ipsrc); 315 print_message(PATH_MESSAGE); 316 while (1) { 317 sleep(10); 318 if (want_death) 319 do_death(1); 320 } 321 } 322 323 /* NOTREACHED */ 324 dogdeath: 325 printf("\r\n\r\nSorry, this service is currently unavailable due to "); 326 printf("technical difficulties\r\n\r\n"); 327 print_message(PATH_PROBLEM); 328 printf("\r\nYour authentication process (pid %ld) was unable to run\n", 329 (long)getpid()); 330 sleep(180); /* them lusers read reaaaaal slow */ 331 die: 332 do_death(0); 333 } 334 335 /* 336 * reads config file in PATH_CONFFILE to set optional behaviours up 337 */ 338 static int 339 read_config(FILE *f) 340 { 341 char buf[1024]; 342 int i = 0; 343 344 do { 345 char **ap; 346 char *pair[4], *cp, *tp; 347 int len; 348 349 if (fgets(buf, sizeof(buf), f) == NULL) { 350 fclose(f); 351 return (0); 352 } 353 i++; 354 len = strlen(buf); 355 if (len == 0) 356 continue; 357 if (buf[len - 1] != '\n' && !feof(f)) { 358 syslog(LOG_ERR, "line %d too long in %s", i, 359 PATH_CONFFILE); 360 return (1); 361 } 362 buf[len - 1] = '\0'; 363 364 for (cp = buf; *cp == ' ' || *cp == '\t'; cp++) 365 ; /* nothing */ 366 367 if (!*cp || *cp == '#' || *cp == '\n') 368 continue; 369 370 for (ap = pair; ap < &pair[3] && 371 (*ap = strsep(&cp, "=")) != NULL; ) { 372 if (**ap != '\0') 373 ap++; 374 } 375 if (ap != &pair[2]) 376 goto parse_error; 377 378 tp = pair[1] + strlen(pair[1]); 379 while ((*tp == ' ' || *tp == '\t') && tp >= pair[1]) 380 *tp-- = '\0'; 381 382 if (strcasecmp(pair[0], "anchor") == 0) { 383 if (!pair[1][0] || strlcpy(anchorname, pair[1], 384 sizeof(anchorname)) >= sizeof(anchorname)) 385 goto parse_error; 386 } 387 if (strcasecmp(pair[0], "table") == 0) { 388 if (!pair[1][0] || strlcpy(tablename, pair[1], 389 sizeof(tablename)) >= sizeof(tablename)) 390 goto parse_error; 391 } 392 } while (!feof(f) && !ferror(f)); 393 fclose(f); 394 return (0); 395 396 parse_error: 397 fclose(f); 398 syslog(LOG_ERR, "parse error, line %d of %s", i, PATH_CONFFILE); 399 return (1); 400 } 401 402 403 /* 404 * splatter a file to stdout - max line length of 1024, 405 * used for spitting message files at users to tell them 406 * they've been bad or we're unavailable. 407 */ 408 static void 409 print_message(const char *filename) 410 { 411 char buf[1024]; 412 FILE *f; 413 414 if ((f = fopen(filename, "r")) == NULL) 415 return; /* fail silently, we don't care if it isn't there */ 416 417 do { 418 if (fgets(buf, sizeof(buf), f) == NULL) { 419 fflush(stdout); 420 fclose(f); 421 return; 422 } 423 } while (fputs(buf, stdout) != EOF && !feof(f)); 424 fflush(stdout); 425 fclose(f); 426 } 427 428 /* 429 * allowed_luser checks to see if user "luser" is allowed to 430 * use this gateway by virtue of being listed in an allowed 431 * users file, namely /etc/authpf/authpf.allow . 432 * 433 * If /etc/authpf/authpf.allow does not exist, then we assume that 434 * all users who are allowed in by sshd(8) are permitted to 435 * use this gateway. If /etc/authpf/authpf.allow does exist, then a 436 * user must be listed if the connection is to continue, else 437 * the session terminates in the same manner as being banned. 438 */ 439 static int 440 allowed_luser(const char *user) 441 { 442 char *buf, *lbuf; 443 int matched; 444 size_t len; 445 FILE *f; 446 447 if ((f = fopen(PATH_ALLOWFILE, "r")) == NULL) { 448 if (errno == ENOENT) { 449 /* 450 * allowfile doesn't exist, thus this gateway 451 * isn't restricted to certain users... 452 */ 453 return (1); 454 } 455 456 /* 457 * user may in fact be allowed, but we can't open 458 * the file even though it's there. probably a config 459 * problem. 460 */ 461 syslog(LOG_ERR, "cannot open allowed users file %s (%s)", 462 PATH_ALLOWFILE, strerror(errno)); 463 return (0); 464 } else { 465 /* 466 * /etc/authpf/authpf.allow exists, thus we do a linear 467 * search to see if they are allowed. 468 * also, if username "*" exists, then this is a 469 * "public" gateway, such as it is, so let 470 * everyone use it. 471 */ 472 lbuf = NULL; 473 while ((buf = fgetln(f, &len))) { 474 if (buf[len - 1] == '\n') 475 buf[len - 1] = '\0'; 476 else { 477 if ((lbuf = (char *)malloc(len + 1)) == NULL) 478 err(1, NULL); 479 memcpy(lbuf, buf, len); 480 lbuf[len] = '\0'; 481 buf = lbuf; 482 } 483 484 matched = strcmp(user, buf) == 0 || strcmp("*", buf) == 0; 485 486 if (lbuf != NULL) { 487 free(lbuf); 488 lbuf = NULL; 489 } 490 491 if (matched) 492 return (1); /* matched an allowed username */ 493 } 494 syslog(LOG_INFO, "denied access to %s: not listed in %s", 495 user, PATH_ALLOWFILE); 496 497 fputs("\n\nSorry, you are not allowed to use this facility!\n", 498 stdout); 499 } 500 fflush(stdout); 501 return (0); 502 } 503 504 /* 505 * check_luser checks to see if user "luser" has been banned 506 * from using us by virtue of having an file of the same name 507 * in the "luserdir" directory. 508 * 509 * If the user has been banned, we copy the contents of the file 510 * to the user's screen. (useful for telling the user what to 511 * do to get un-banned, or just to tell them they aren't 512 * going to be un-banned.) 513 */ 514 static int 515 check_luser(const char *userdir, const char *user) 516 { 517 FILE *f; 518 int n; 519 char tmp[MAXPATHLEN]; 520 521 n = snprintf(tmp, sizeof(tmp), "%s/%s", userdir, user); 522 if (n < 0 || (u_int)n >= sizeof(tmp)) { 523 syslog(LOG_ERR, "provided banned directory line too long (%s)", 524 userdir); 525 return (0); 526 } 527 if ((f = fopen(tmp, "r")) == NULL) { 528 if (errno == ENOENT) { 529 /* 530 * file or dir doesn't exist, so therefore 531 * this luser isn't banned.. all is well 532 */ 533 return (1); 534 } else { 535 /* 536 * user may in fact be banned, but we can't open the 537 * file even though it's there. probably a config 538 * problem. 539 */ 540 syslog(LOG_ERR, "cannot open banned file %s (%s)", 541 tmp, strerror(errno)); 542 return (0); 543 } 544 } else { 545 /* 546 * user is banned - spit the file at them to 547 * tell what they can do and where they can go. 548 */ 549 syslog(LOG_INFO, "denied access to %s: %s exists", 550 luser, tmp); 551 552 /* reuse tmp */ 553 strlcpy(tmp, "\n\n-**- Sorry, you have been banned! -**-\n\n", 554 sizeof(tmp)); 555 while (fputs(tmp, stdout) != EOF && !feof(f)) { 556 if (fgets(tmp, sizeof(tmp), f) == NULL) { 557 fflush(stdout); 558 fclose(f); 559 return (0); 560 } 561 } 562 fclose(f); 563 } 564 fflush(stdout); 565 return (0); 566 } 567 568 /* 569 * Search for rulesets left by other authpf processes (either because they 570 * died ungracefully or were terminated) and remove them. 571 */ 572 static int 573 remove_stale_rulesets(void) 574 { 575 struct pfioc_ruleset prs; 576 u_int32_t nr, mnr; 577 578 memset(&prs, 0, sizeof(prs)); 579 strlcpy(prs.path, anchorname, sizeof(prs.path)); 580 if (ioctl(dev_fd, DIOCGETRULESETS, &prs)) { 581 if (errno == EINVAL) 582 return (0); 583 else 584 return (1); 585 } 586 587 mnr = prs.nr; 588 nr = 0; 589 while (nr < mnr) { 590 char *s, *t; 591 pid_t pid; 592 593 prs.nr = nr; 594 if (ioctl(dev_fd, DIOCGETRULESET, &prs)) 595 return (1); 596 errno = 0; 597 if ((t = strchr(prs.name, '(')) == NULL) 598 t = prs.name; 599 else 600 t++; 601 pid = strtoul(t, &s, 10); 602 if (!prs.name[0] || errno || 603 (*s && (t == prs.name || *s != ')'))) 604 return (1); 605 if (kill(pid, 0) && errno != EPERM) { 606 int i; 607 struct pfioc_trans_e t_e[PF_RULESET_MAX+1]; 608 struct pfioc_trans t_local; 609 610 bzero(&t_local, sizeof(t_local)); 611 bzero(t_e, sizeof(t_e)); 612 t_local.size = PF_RULESET_MAX+1; 613 t_local.esize = sizeof(t_e[0]); 614 t_local.array = t_e; 615 for (i = 0; i < PF_RULESET_MAX+1; ++i) { 616 t_e[i].rs_num = i; 617 snprintf(t_e[i].anchor, sizeof(t_e[i].anchor), 618 "%s/%s", anchorname, prs.name); 619 } 620 mnr--; 621 } else 622 nr++; 623 } 624 return (0); 625 } 626 627 /* 628 * Add/remove filter entries for user "luser" from ip "ipsrc" 629 */ 630 static int 631 change_filter(int add, const char *user, const char *his_ipsrc) 632 { 633 const char *pargv[13] = { 634 "pfctl", "-p", "/dev/pf", "-q", "-a", "anchor/ruleset", 635 "-D", "user_ip=X", "-D", "user_id=X", "-f", 636 "file", NULL 637 }; 638 char *fdpath = NULL, *userstr = NULL, *ipstr = NULL; 639 char *rsn = NULL, *fn = NULL; 640 pid_t pid; 641 gid_t gid; 642 int s; 643 644 if (user == NULL || !user[0] || his_ipsrc == NULL || !his_ipsrc[0]) { 645 syslog(LOG_ERR, "invalid user/ipsrc"); 646 goto error; 647 } 648 649 if (asprintf(&rsn, "%s/%s", anchorname, rulesetname) == -1) 650 goto no_mem; 651 if (asprintf(&fdpath, "/dev/fd/%d", dev_fd) == -1) 652 goto no_mem; 653 if (asprintf(&ipstr, "user_ip=%s", his_ipsrc) == -1) 654 goto no_mem; 655 if (asprintf(&userstr, "user_id=%s", user) == -1) 656 goto no_mem; 657 658 if (add) { 659 struct stat sb; 660 661 if (asprintf(&fn, "%s/%s/authpf.rules", PATH_USER_DIR, user) 662 == -1) 663 goto no_mem; 664 if (stat(fn, &sb) == -1) { 665 free(fn); 666 if ((fn = strdup(PATH_PFRULES)) == NULL) 667 goto no_mem; 668 } 669 } 670 pargv[2] = fdpath; 671 pargv[5] = rsn; 672 pargv[7] = userstr; 673 pargv[9] = ipstr; 674 if (!add) 675 pargv[11] = "/dev/null"; 676 else 677 pargv[11] = fn; 678 679 switch (pid = fork()) { 680 case -1: 681 syslog(LOG_ERR, "fork failed"); 682 goto error; 683 case 0: 684 /* revoke group privs before exec */ 685 gid = getgid(); 686 if (setregid(gid, gid) == -1) { 687 err(1, "setregid"); 688 } 689 execvp(PATH_PFCTL, __DECONST(char *const *, pargv)); 690 warn("exec of %s failed", PATH_PFCTL); 691 _exit(1); 692 } 693 694 /* parent */ 695 waitpid(pid, &s, 0); 696 if (s != 0) { 697 syslog(LOG_ERR, "pfctl exited abnormally"); 698 goto error; 699 } 700 701 if (add) { 702 gettimeofday(&Tstart, NULL); 703 syslog(LOG_INFO, "allowing %s, user %s", his_ipsrc, user); 704 } else { 705 gettimeofday(&Tend, NULL); 706 syslog(LOG_INFO, "removed %s, user %s - duration %ld seconds", 707 his_ipsrc, user, Tend.tv_sec - Tstart.tv_sec); 708 } 709 return (0); 710 no_mem: 711 syslog(LOG_ERR, "malloc failed"); 712 error: 713 free(fdpath); 714 free(rsn); 715 free(userstr); 716 free(ipstr); 717 free(fn); 718 return (-1); 719 } 720 721 /* 722 * Add/remove this IP from the "authpf_users" table. 723 */ 724 static int 725 change_table(int add, const char *his_ipsrc) 726 { 727 struct pfioc_table io; 728 struct pfr_addr addr; 729 730 bzero(&io, sizeof(io)); 731 strlcpy(io.pfrio_table.pfrt_name, tablename, 732 sizeof(io.pfrio_table.pfrt_name)); 733 io.pfrio_buffer = &addr; 734 io.pfrio_esize = sizeof(addr); 735 io.pfrio_size = 1; 736 737 bzero(&addr, sizeof(addr)); 738 if (his_ipsrc == NULL || !his_ipsrc[0]) 739 return (-1); 740 if (inet_pton(AF_INET, his_ipsrc, &addr.pfra_ip4addr) == 1) { 741 addr.pfra_af = AF_INET; 742 addr.pfra_net = 32; 743 } else if (inet_pton(AF_INET6, his_ipsrc, &addr.pfra_ip6addr) == 1) { 744 addr.pfra_af = AF_INET6; 745 addr.pfra_net = 128; 746 } else { 747 syslog(LOG_ERR, "invalid his_ipsrc"); 748 return (-1); 749 } 750 751 if (ioctl(dev_fd, add ? DIOCRADDADDRS : DIOCRDELADDRS, &io) && 752 errno != ESRCH) { 753 syslog(LOG_ERR, "cannot %s %s from table %s: %s", 754 add ? "add" : "remove", his_ipsrc, tablename, 755 strerror(errno)); 756 return (-1); 757 } 758 return (0); 759 } 760 761 /* 762 * This is to kill off states that would otherwise be left behind stateful 763 * rules. This means we don't need to allow in more traffic than we really 764 * want to, since we don't have to worry about any luser sessions lasting 765 * longer than their ssh session. This function is based on 766 * pfctl_kill_states from pfctl. 767 */ 768 static void 769 authpf_kill_states(void) 770 { 771 struct pfioc_state_kill psk; 772 struct pf_addr target; 773 774 memset(&psk, 0, sizeof(psk)); 775 memset(&target, 0, sizeof(target)); 776 777 if (inet_pton(AF_INET, ipsrc, &target.v4) == 1) 778 psk.psk_af = AF_INET; 779 else if (inet_pton(AF_INET6, ipsrc, &target.v6) == 1) 780 psk.psk_af = AF_INET6; 781 else { 782 syslog(LOG_ERR, "inet_pton(%s) failed", ipsrc); 783 return; 784 } 785 786 /* Kill all states from ipsrc */ 787 memcpy(&psk.psk_src.addr.v.a.addr, &target, 788 sizeof(psk.psk_src.addr.v.a.addr)); 789 memset(&psk.psk_src.addr.v.a.mask, 0xff, 790 sizeof(psk.psk_src.addr.v.a.mask)); 791 if (ioctl(dev_fd, DIOCKILLSTATES, &psk)) 792 syslog(LOG_ERR, "DIOCKILLSTATES failed (%m)"); 793 794 /* Kill all states to ipsrc */ 795 memset(&psk.psk_src, 0, sizeof(psk.psk_src)); 796 memcpy(&psk.psk_dst.addr.v.a.addr, &target, 797 sizeof(psk.psk_dst.addr.v.a.addr)); 798 memset(&psk.psk_dst.addr.v.a.mask, 0xff, 799 sizeof(psk.psk_dst.addr.v.a.mask)); 800 if (ioctl(dev_fd, DIOCKILLSTATES, &psk)) 801 syslog(LOG_ERR, "DIOCKILLSTATES failed (%m)"); 802 } 803 804 /* signal handler that makes us go away properly */ 805 static void 806 need_death(int signo __unused) 807 { 808 want_death = 1; 809 } 810 811 /* 812 * function that removes our stuff when we go away. 813 */ 814 static __dead void 815 do_death(int active) 816 { 817 int ret = 0; 818 819 if (active) { 820 change_filter(0, luser, ipsrc); 821 change_table(0, ipsrc); 822 authpf_kill_states(); 823 remove_stale_rulesets(); 824 } 825 if (pidfile[0] && (pidfp != NULL)) 826 if (unlink(pidfile) == -1) 827 syslog(LOG_ERR, "cannot unlink %s (%m)", pidfile); 828 exit(ret); 829 } 830