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 #define _KERNEL_STRUCTURES 22 #include <sys/param.h> 23 #include <sys/types.h> 24 #include <sys/file.h> 25 #include <sys/ioctl.h> 26 #include <sys/socket.h> 27 #include <sys/stat.h> 28 #include <sys/time.h> 29 #include <sys/wait.h> 30 31 #include <net/if.h> 32 #include <net/pf/pfvar.h> 33 #include <arpa/inet.h> 34 35 #include <err.h> 36 #include <errno.h> 37 #include <login_cap.h> 38 #include <pwd.h> 39 #include <signal.h> 40 #include <stdio.h> 41 #include <stdlib.h> 42 #include <string.h> 43 #include <syslog.h> 44 #include <unistd.h> 45 46 #include "pathnames.h" 47 48 #define __dead __dead2 49 50 static int read_config(FILE *); 51 static void print_message(const char *); 52 static int allowed_luser(const char *); 53 static int check_luser(const char *, const char *); 54 static int remove_stale_rulesets(void); 55 static int change_filter(int, const char *, const char *); 56 static int change_table(int, const char *); 57 static void authpf_kill_states(void); 58 59 int dev_fd; /* pf device */ 60 char anchorname[PF_ANCHOR_NAME_SIZE] = "authpf"; 61 char rulesetname[MAXPATHLEN - PF_ANCHOR_NAME_SIZE - 2]; 62 char tablename[PF_TABLE_NAME_SIZE] = "authpf_users"; 63 64 FILE *pidfp; 65 char luser[MAXLOGNAME]; /* username */ 66 char ipsrc[256]; /* ip as a string */ 67 char pidfile[MAXPATHLEN]; /* we save pid in this file. */ 68 69 struct timeval Tstart, Tend; /* start and end times of session */ 70 71 volatile sig_atomic_t want_death; 72 static void need_death(int signo); 73 static __dead void do_death(int); 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 __unused, char **argv __unused) 83 { 84 int lockcnt = 0, n, pidfd; 85 FILE *config; 86 struct in6_addr ina; 87 struct passwd *pw; 88 char *cp; 89 gid_t gid; 90 uid_t uid; 91 const char *shell; 92 login_cap_t *lc; 93 94 config = fopen(PATH_CONFFILE, "r"); 95 if (config == NULL) { 96 syslog(LOG_ERR, "cannot open %s (%m)", PATH_CONFFILE); 97 exit(1); 98 } 99 100 if ((cp = getenv("SSH_TTY")) == NULL) { 101 syslog(LOG_ERR, "non-interactive session connection for authpf"); 102 exit(1); 103 } 104 105 if ((cp = getenv("SSH_CLIENT")) == NULL) { 106 syslog(LOG_ERR, "cannot determine connection source"); 107 exit(1); 108 } 109 110 if (strlcpy(ipsrc, cp, sizeof(ipsrc)) >= sizeof(ipsrc)) { 111 syslog(LOG_ERR, "SSH_CLIENT variable too long"); 112 exit(1); 113 } 114 cp = strchr(ipsrc, ' '); 115 if (!cp) { 116 syslog(LOG_ERR, "corrupt SSH_CLIENT variable %s", ipsrc); 117 exit(1); 118 } 119 *cp = '\0'; 120 if (inet_pton(AF_INET, ipsrc, &ina) != 1 && 121 inet_pton(AF_INET6, ipsrc, &ina) != 1) { 122 syslog(LOG_ERR, 123 "cannot determine IP from SSH_CLIENT %s", ipsrc); 124 exit(1); 125 } 126 /* open the pf device */ 127 dev_fd = open(PATH_DEVFILE, O_RDWR); 128 if (dev_fd == -1) { 129 syslog(LOG_ERR, "cannot open packet filter device (%m)"); 130 goto die; 131 } 132 133 uid = getuid(); 134 pw = getpwuid(uid); 135 if (pw == NULL) { 136 syslog(LOG_ERR, "cannot find user for uid %u", uid); 137 goto die; 138 } 139 140 if ((lc = login_getclass(pw->pw_class)) != NULL) 141 shell = login_getcapstr(lc, "shell", pw->pw_shell, 142 pw->pw_shell); 143 else 144 shell = pw->pw_shell; 145 146 147 148 if (strcmp(shell, PATH_AUTHPF_SHELL)) { 149 syslog(LOG_ERR, "wrong shell for user %s, uid %u", 150 pw->pw_name, pw->pw_uid); 151 login_close(lc); 152 goto die; 153 } 154 155 login_close(lc); 156 157 /* 158 * Paranoia, but this data _does_ come from outside authpf, and 159 * truncation would be bad. 160 */ 161 if (strlcpy(luser, pw->pw_name, sizeof(luser)) >= sizeof(luser)) { 162 syslog(LOG_ERR, "username too long: %s", pw->pw_name); 163 goto die; 164 } 165 166 if ((n = snprintf(rulesetname, sizeof(rulesetname), "%s(%ld)", 167 luser, (long)getpid())) < 0 || (u_int)n >= sizeof(rulesetname)) { 168 syslog(LOG_INFO, "%s(%ld) too large, ruleset name will be %ld", 169 luser, (long)getpid(), (long)getpid()); 170 if ((n = snprintf(rulesetname, sizeof(rulesetname), "%ld", 171 (long)getpid())) < 0 || (u_int)n >= sizeof(rulesetname)) { 172 syslog(LOG_ERR, "pid too large for ruleset name"); 173 goto die; 174 } 175 } 176 177 178 /* Make our entry in /var/authpf as /var/authpf/ipaddr */ 179 n = snprintf(pidfile, sizeof(pidfile), "%s/%s", PATH_PIDFILE, ipsrc); 180 if (n < 0 || (u_int)n >= sizeof(pidfile)) { 181 syslog(LOG_ERR, "path to pidfile too long"); 182 goto die; 183 } 184 185 /* 186 * If someone else is already using this ip, then this person 187 * wants to switch users - so kill the old process and exit 188 * as well. 189 * 190 * Note, we could print a message and tell them to log out, but the 191 * usual case of this is that someone has left themselves logged in, 192 * with the authenticated connection iconized and someone else walks 193 * up to use and automatically logs in before using. If this just 194 * gets rid of the old one silently, the new user never knows they 195 * could have used someone else's old authentication. If we 196 * tell them to log out before switching users it is an invitation 197 * for abuse. 198 */ 199 200 do { 201 int save_errno, otherpid = -1; 202 char otherluser[MAXLOGNAME]; 203 204 if ((pidfd = open(pidfile, O_RDWR|O_CREAT, 0644)) == -1 || 205 (pidfp = fdopen(pidfd, "r+")) == NULL) { 206 if (pidfd != -1) 207 close(pidfd); 208 syslog(LOG_ERR, "cannot open or create %s: %s", pidfile, 209 strerror(errno)); 210 goto die; 211 } 212 213 if (flock(fileno(pidfp), LOCK_EX|LOCK_NB) == 0) 214 break; 215 save_errno = errno; 216 217 /* Mark our pid, and username to our file. */ 218 219 rewind(pidfp); 220 /* 31 == MAXLOGNAME - 1 */ 221 if (fscanf(pidfp, "%d\n%31s\n", &otherpid, otherluser) != 2) 222 otherpid = -1; 223 syslog(LOG_DEBUG, "tried to lock %s, in use by pid %d: %s", 224 pidfile, otherpid, strerror(save_errno)); 225 226 if (otherpid > 0) { 227 syslog(LOG_INFO, 228 "killing prior auth (pid %d) of %s by user %s", 229 otherpid, ipsrc, otherluser); 230 if (kill((pid_t) otherpid, SIGTERM) == -1) { 231 syslog(LOG_INFO, 232 "could not kill process %d: (%m)", 233 otherpid); 234 } 235 } 236 237 /* 238 * We try to kill the previous process and acquire the lock 239 * for 10 seconds, trying once a second. if we can't after 240 * 10 attempts we log an error and give up. 241 */ 242 if (++lockcnt > 10) { 243 syslog(LOG_ERR, "cannot kill previous authpf (pid %d)", 244 otherpid); 245 fclose(pidfp); 246 pidfp = NULL; 247 goto dogdeath; 248 } 249 sleep(1); 250 251 /* re-open, and try again. The previous authpf process 252 * we killed above should unlink the file and release 253 * it's lock, giving us a chance to get it now 254 */ 255 fclose(pidfp); 256 pidfp = NULL; 257 } while (1); 258 259 /* whack the group list */ 260 gid = getegid(); 261 if (setgroups(1, &gid) == -1) { 262 syslog(LOG_INFO, "setgroups: %s", strerror(errno)); 263 do_death(0); 264 } 265 266 /* revoke privs */ 267 uid = getuid(); 268 if (setresuid(uid, uid, uid) == -1) { 269 syslog(LOG_INFO, "setresuid: %s", strerror(errno)); 270 do_death(0); 271 } 272 openlog("authpf", LOG_PID | LOG_NDELAY, LOG_DAEMON); 273 274 if (!check_luser(PATH_BAN_DIR, luser) || !allowed_luser(luser)) { 275 syslog(LOG_INFO, "user %s prohibited", luser); 276 do_death(0); 277 } 278 279 if (read_config(config)) { 280 syslog(LOG_ERR, "invalid config file %s", PATH_CONFFILE); 281 do_death(0); 282 } 283 284 if (remove_stale_rulesets()) { 285 syslog(LOG_INFO, "error removing stale rulesets"); 286 do_death(0); 287 } 288 289 /* We appear to be making headway, so actually mark our pid */ 290 rewind(pidfp); 291 fprintf(pidfp, "%ld\n%s\n", (long)getpid(), luser); 292 fflush(pidfp); 293 ftruncate(fileno(pidfp), ftell(pidfp)); 294 295 if (change_filter(1, luser, ipsrc) == -1) { 296 printf("Unable to modify filters\r\n"); 297 do_death(0); 298 } 299 if (change_table(1, ipsrc) == -1) { 300 printf("Unable to modify table\r\n"); 301 change_filter(0, luser, ipsrc); 302 do_death(0); 303 } 304 305 signal(SIGTERM, need_death); 306 signal(SIGINT, need_death); 307 signal(SIGALRM, need_death); 308 signal(SIGPIPE, need_death); 309 signal(SIGHUP, need_death); 310 signal(SIGQUIT, need_death); 311 signal(SIGTSTP, need_death); 312 while (1) { 313 printf("\r\nHello %s. ", luser); 314 printf("You are authenticated from host \"%s\"\r\n", ipsrc); 315 setproctitle("%s@%s", luser, ipsrc); 316 print_message(PATH_MESSAGE); 317 while (1) { 318 sleep(10); 319 if (want_death) 320 do_death(1); 321 } 322 } 323 324 /* NOTREACHED */ 325 dogdeath: 326 printf("\r\n\r\nSorry, this service is currently unavailable due to "); 327 printf("technical difficulties\r\n\r\n"); 328 print_message(PATH_PROBLEM); 329 printf("\r\nYour authentication process (pid %ld) was unable to run\n", 330 (long)getpid()); 331 sleep(180); /* them lusers read reaaaaal slow */ 332 die: 333 do_death(0); 334 } 335 336 /* 337 * reads config file in PATH_CONFFILE to set optional behaviours up 338 */ 339 static int 340 read_config(FILE *f) 341 { 342 char buf[1024]; 343 int i = 0; 344 345 do { 346 char **ap; 347 char *pair[4], *cp, *tp; 348 int len; 349 350 if (fgets(buf, sizeof(buf), f) == NULL) { 351 fclose(f); 352 return (0); 353 } 354 i++; 355 len = strlen(buf); 356 if (len == 0) 357 continue; 358 if (buf[len - 1] != '\n' && !feof(f)) { 359 syslog(LOG_ERR, "line %d too long in %s", i, 360 PATH_CONFFILE); 361 return (1); 362 } 363 buf[len - 1] = '\0'; 364 365 for (cp = buf; *cp == ' ' || *cp == '\t'; cp++) 366 ; /* nothing */ 367 368 if (!*cp || *cp == '#' || *cp == '\n') 369 continue; 370 371 for (ap = pair; ap < &pair[3] && 372 (*ap = strsep(&cp, "=")) != NULL; ) { 373 if (**ap != '\0') 374 ap++; 375 } 376 if (ap != &pair[2]) 377 goto parse_error; 378 379 tp = pair[1] + strlen(pair[1]); 380 while ((*tp == ' ' || *tp == '\t') && tp >= pair[1]) 381 *tp-- = '\0'; 382 383 if (strcasecmp(pair[0], "anchor") == 0) { 384 if (!pair[1][0] || strlcpy(anchorname, pair[1], 385 sizeof(anchorname)) >= sizeof(anchorname)) 386 goto parse_error; 387 } 388 if (strcasecmp(pair[0], "table") == 0) { 389 if (!pair[1][0] || strlcpy(tablename, pair[1], 390 sizeof(tablename)) >= sizeof(tablename)) 391 goto parse_error; 392 } 393 } while (!feof(f) && !ferror(f)); 394 fclose(f); 395 return (0); 396 397 parse_error: 398 fclose(f); 399 syslog(LOG_ERR, "parse error, line %d of %s", i, PATH_CONFFILE); 400 return (1); 401 } 402 403 404 /* 405 * splatter a file to stdout - max line length of 1024, 406 * used for spitting message files at users to tell them 407 * they've been bad or we're unavailable. 408 */ 409 static void 410 print_message(const char *filename) 411 { 412 char buf[1024]; 413 FILE *f; 414 415 if ((f = fopen(filename, "r")) == NULL) 416 return; /* fail silently, we don't care if it isn't there */ 417 418 do { 419 if (fgets(buf, sizeof(buf), f) == NULL) { 420 fflush(stdout); 421 fclose(f); 422 return; 423 } 424 } while (fputs(buf, stdout) != EOF && !feof(f)); 425 fflush(stdout); 426 fclose(f); 427 } 428 429 /* 430 * allowed_luser checks to see if user "luser" is allowed to 431 * use this gateway by virtue of being listed in an allowed 432 * users file, namely /etc/authpf/authpf.allow . 433 * 434 * If /etc/authpf/authpf.allow does not exist, then we assume that 435 * all users who are allowed in by sshd(8) are permitted to 436 * use this gateway. If /etc/authpf/authpf.allow does exist, then a 437 * user must be listed if the connection is to continue, else 438 * the session terminates in the same manner as being banned. 439 */ 440 static int 441 allowed_luser(const char *user) 442 { 443 char *buf, *lbuf; 444 int matched; 445 size_t len; 446 FILE *f; 447 448 if ((f = fopen(PATH_ALLOWFILE, "r")) == NULL) { 449 if (errno == ENOENT) { 450 /* 451 * allowfile doesn't exist, thus this gateway 452 * isn't restricted to certain users... 453 */ 454 return (1); 455 } 456 457 /* 458 * user may in fact be allowed, but we can't open 459 * the file even though it's there. probably a config 460 * problem. 461 */ 462 syslog(LOG_ERR, "cannot open allowed users file %s (%s)", 463 PATH_ALLOWFILE, strerror(errno)); 464 return (0); 465 } else { 466 /* 467 * /etc/authpf/authpf.allow exists, thus we do a linear 468 * search to see if they are allowed. 469 * also, if username "*" exists, then this is a 470 * "public" gateway, such as it is, so let 471 * everyone use it. 472 */ 473 lbuf = NULL; 474 while ((buf = fgetln(f, &len))) { 475 if (buf[len - 1] == '\n') 476 buf[len - 1] = '\0'; 477 else { 478 if ((lbuf = (char *)malloc(len + 1)) == NULL) 479 err(1, NULL); 480 memcpy(lbuf, buf, len); 481 lbuf[len] = '\0'; 482 buf = lbuf; 483 } 484 485 matched = strcmp(user, buf) == 0 || strcmp("*", buf) == 0; 486 487 if (lbuf != NULL) { 488 free(lbuf); 489 lbuf = NULL; 490 } 491 492 if (matched) 493 return (1); /* matched an allowed username */ 494 } 495 syslog(LOG_INFO, "denied access to %s: not listed in %s", 496 user, PATH_ALLOWFILE); 497 498 fputs("\n\nSorry, you are not allowed to use this facility!\n", 499 stdout); 500 } 501 fflush(stdout); 502 return (0); 503 } 504 505 /* 506 * check_luser checks to see if user "luser" has been banned 507 * from using us by virtue of having an file of the same name 508 * in the "luserdir" directory. 509 * 510 * If the user has been banned, we copy the contents of the file 511 * to the user's screen. (useful for telling the user what to 512 * do to get un-banned, or just to tell them they aren't 513 * going to be un-banned.) 514 */ 515 static int 516 check_luser(const char *userdir, const char *user) 517 { 518 FILE *f; 519 int n; 520 char tmp[MAXPATHLEN]; 521 522 n = snprintf(tmp, sizeof(tmp), "%s/%s", userdir, user); 523 if (n < 0 || (u_int)n >= sizeof(tmp)) { 524 syslog(LOG_ERR, "provided banned directory line too long (%s)", 525 userdir); 526 return (0); 527 } 528 if ((f = fopen(tmp, "r")) == NULL) { 529 if (errno == ENOENT) { 530 /* 531 * file or dir doesn't exist, so therefore 532 * this luser isn't banned.. all is well 533 */ 534 return (1); 535 } else { 536 /* 537 * user may in fact be banned, but we can't open the 538 * file even though it's there. probably a config 539 * problem. 540 */ 541 syslog(LOG_ERR, "cannot open banned file %s (%s)", 542 tmp, strerror(errno)); 543 return (0); 544 } 545 } else { 546 /* 547 * user is banned - spit the file at them to 548 * tell what they can do and where they can go. 549 */ 550 syslog(LOG_INFO, "denied access to %s: %s exists", 551 luser, tmp); 552 553 /* reuse tmp */ 554 strlcpy(tmp, "\n\n-**- Sorry, you have been banned! -**-\n\n", 555 sizeof(tmp)); 556 while (fputs(tmp, stdout) != EOF && !feof(f)) { 557 if (fgets(tmp, sizeof(tmp), f) == NULL) { 558 fflush(stdout); 559 fclose(f); 560 return (0); 561 } 562 } 563 fclose(f); 564 } 565 fflush(stdout); 566 return (0); 567 } 568 569 /* 570 * Search for rulesets left by other authpf processes (either because they 571 * died ungracefully or were terminated) and remove them. 572 */ 573 static int 574 remove_stale_rulesets(void) 575 { 576 struct pfioc_ruleset prs; 577 u_int32_t nr, mnr; 578 579 memset(&prs, 0, sizeof(prs)); 580 strlcpy(prs.path, anchorname, sizeof(prs.path)); 581 if (ioctl(dev_fd, DIOCGETRULESETS, &prs)) { 582 if (errno == EINVAL) 583 return (0); 584 else 585 return (1); 586 } 587 588 mnr = prs.nr; 589 nr = 0; 590 while (nr < mnr) { 591 char *s, *t; 592 pid_t pid; 593 594 prs.nr = nr; 595 if (ioctl(dev_fd, DIOCGETRULESET, &prs)) 596 return (1); 597 errno = 0; 598 if ((t = strchr(prs.name, '(')) == NULL) 599 t = prs.name; 600 else 601 t++; 602 pid = strtoul(t, &s, 10); 603 if (!prs.name[0] || errno || 604 (*s && (t == prs.name || *s != ')'))) 605 return (1); 606 if (kill(pid, 0) && errno != EPERM) { 607 int i; 608 struct pfioc_trans_e t_e[PF_RULESET_MAX+1]; 609 struct pfioc_trans t_local; 610 611 bzero(&t, sizeof(t_local)); 612 bzero(t_e, sizeof(t_e)); 613 t_local.size = PF_RULESET_MAX+1; 614 t_local.esize = sizeof(t_e[0]); 615 t_local.array = t_e; 616 for (i = 0; i < PF_RULESET_MAX+1; ++i) { 617 t_e[i].rs_num = i; 618 snprintf(t_e[i].anchor, sizeof(t_e[i].anchor), 619 "%s/%s", anchorname, prs.name); 620 } 621 mnr--; 622 } else 623 nr++; 624 } 625 return (0); 626 } 627 628 /* 629 * Add/remove filter entries for user "luser" from ip "ipsrc" 630 */ 631 static int 632 change_filter(int add, const char *user, const char *his_ipsrc) 633 { 634 const char *pargv[13] = { 635 "pfctl", "-p", "/dev/pf", "-q", "-a", "anchor/ruleset", 636 "-D", "user_ip=X", "-D", "user_id=X", "-f", 637 "file", NULL 638 }; 639 char *fdpath = NULL, *userstr = NULL, *ipstr = NULL; 640 char *rsn = NULL, *fn = NULL; 641 pid_t pid; 642 gid_t gid; 643 int s; 644 645 if (user == NULL || !user[0] || his_ipsrc == NULL || !his_ipsrc[0]) { 646 syslog(LOG_ERR, "invalid user/ipsrc"); 647 goto error; 648 } 649 650 if (asprintf(&rsn, "%s/%s", anchorname, rulesetname) == -1) 651 goto no_mem; 652 if (asprintf(&fdpath, "/dev/fd/%d", dev_fd) == -1) 653 goto no_mem; 654 if (asprintf(&ipstr, "user_ip=%s", his_ipsrc) == -1) 655 goto no_mem; 656 if (asprintf(&userstr, "user_id=%s", user) == -1) 657 goto no_mem; 658 659 if (add) { 660 struct stat sb; 661 662 if (asprintf(&fn, "%s/%s/authpf.rules", PATH_USER_DIR, user) 663 == -1) 664 goto no_mem; 665 if (stat(fn, &sb) == -1) { 666 free(fn); 667 if ((fn = strdup(PATH_PFRULES)) == NULL) 668 goto no_mem; 669 } 670 } 671 pargv[2] = fdpath; 672 pargv[5] = rsn; 673 pargv[7] = userstr; 674 pargv[9] = ipstr; 675 if (!add) 676 pargv[11] = "/dev/null"; 677 else 678 pargv[11] = fn; 679 680 switch (pid = fork()) { 681 case -1: 682 syslog(LOG_ERR, "fork failed"); 683 goto error; 684 case 0: 685 /* revoke group privs before exec */ 686 gid = getgid(); 687 if (setregid(gid, gid) == -1) { 688 err(1, "setregid"); 689 } 690 execvp(PATH_PFCTL, __DECONST(char *const *, pargv)); 691 warn("exec of %s failed", PATH_PFCTL); 692 _exit(1); 693 } 694 695 /* parent */ 696 waitpid(pid, &s, 0); 697 if (s != 0) { 698 syslog(LOG_ERR, "pfctl exited abnormally"); 699 goto error; 700 } 701 702 if (add) { 703 gettimeofday(&Tstart, NULL); 704 syslog(LOG_INFO, "allowing %s, user %s", his_ipsrc, user); 705 } else { 706 gettimeofday(&Tend, NULL); 707 syslog(LOG_INFO, "removed %s, user %s - duration %ld seconds", 708 his_ipsrc, user, Tend.tv_sec - Tstart.tv_sec); 709 } 710 return (0); 711 no_mem: 712 syslog(LOG_ERR, "malloc failed"); 713 error: 714 free(fdpath); 715 free(rsn); 716 free(userstr); 717 free(ipstr); 718 free(fn); 719 return (-1); 720 } 721 722 /* 723 * Add/remove this IP from the "authpf_users" table. 724 */ 725 static int 726 change_table(int add, const char *his_ipsrc) 727 { 728 struct pfioc_table io; 729 struct pfr_addr addr; 730 731 bzero(&io, sizeof(io)); 732 strlcpy(io.pfrio_table.pfrt_name, tablename, 733 sizeof(io.pfrio_table.pfrt_name)); 734 io.pfrio_buffer = &addr; 735 io.pfrio_esize = sizeof(addr); 736 io.pfrio_size = 1; 737 738 bzero(&addr, sizeof(addr)); 739 if (his_ipsrc == NULL || !his_ipsrc[0]) 740 return (-1); 741 if (inet_pton(AF_INET, his_ipsrc, &addr.pfra_ip4addr) == 1) { 742 addr.pfra_af = AF_INET; 743 addr.pfra_net = 32; 744 } else if (inet_pton(AF_INET6, his_ipsrc, &addr.pfra_ip6addr) == 1) { 745 addr.pfra_af = AF_INET6; 746 addr.pfra_net = 128; 747 } else { 748 syslog(LOG_ERR, "invalid his_ipsrc"); 749 return (-1); 750 } 751 752 if (ioctl(dev_fd, add ? DIOCRADDADDRS : DIOCRDELADDRS, &io) && 753 errno != ESRCH) { 754 syslog(LOG_ERR, "cannot %s %s from table %s: %s", 755 add ? "add" : "remove", his_ipsrc, tablename, 756 strerror(errno)); 757 return (-1); 758 } 759 return (0); 760 } 761 762 /* 763 * This is to kill off states that would otherwise be left behind stateful 764 * rules. This means we don't need to allow in more traffic than we really 765 * want to, since we don't have to worry about any luser sessions lasting 766 * longer than their ssh session. This function is based on 767 * pfctl_kill_states from pfctl. 768 */ 769 static void 770 authpf_kill_states(void) 771 { 772 struct pfioc_state_kill psk; 773 struct pf_addr target; 774 775 memset(&psk, 0, sizeof(psk)); 776 memset(&target, 0, sizeof(target)); 777 778 if (inet_pton(AF_INET, ipsrc, &target.v4) == 1) 779 psk.psk_af = AF_INET; 780 else if (inet_pton(AF_INET6, ipsrc, &target.v6) == 1) 781 psk.psk_af = AF_INET6; 782 else { 783 syslog(LOG_ERR, "inet_pton(%s) failed", ipsrc); 784 return; 785 } 786 787 /* Kill all states from ipsrc */ 788 memcpy(&psk.psk_src.addr.v.a.addr, &target, 789 sizeof(psk.psk_src.addr.v.a.addr)); 790 memset(&psk.psk_src.addr.v.a.mask, 0xff, 791 sizeof(psk.psk_src.addr.v.a.mask)); 792 if (ioctl(dev_fd, DIOCKILLSTATES, &psk)) 793 syslog(LOG_ERR, "DIOCKILLSTATES failed (%m)"); 794 795 /* Kill all states to ipsrc */ 796 memset(&psk.psk_src, 0, sizeof(psk.psk_src)); 797 memcpy(&psk.psk_dst.addr.v.a.addr, &target, 798 sizeof(psk.psk_dst.addr.v.a.addr)); 799 memset(&psk.psk_dst.addr.v.a.mask, 0xff, 800 sizeof(psk.psk_dst.addr.v.a.mask)); 801 if (ioctl(dev_fd, DIOCKILLSTATES, &psk)) 802 syslog(LOG_ERR, "DIOCKILLSTATES failed (%m)"); 803 } 804 805 /* signal handler that makes us go away properly */ 806 static void 807 need_death(int signo __unused) 808 { 809 want_death = 1; 810 } 811 812 /* 813 * function that removes our stuff when we go away. 814 */ 815 static __dead void 816 do_death(int active) 817 { 818 int ret = 0; 819 820 if (active) { 821 change_filter(0, luser, ipsrc); 822 change_table(0, ipsrc); 823 authpf_kill_states(); 824 remove_stale_rulesets(); 825 } 826 if (pidfile[0] && (pidfp != NULL)) 827 if (unlink(pidfile) == -1) 828 syslog(LOG_ERR, "cannot unlink %s (%m)", pidfile); 829 exit(ret); 830 } 831