1 /* $NetBSD: authpf.c,v 1.7 2008/12/29 04:13:28 christos Exp $ */ 2 /* $OpenBSD: authpf.c,v 1.104 2007/02/24 17:35:08 beck Exp $ */ 3 4 /* 5 * Copyright (C) 1998 - 2007 Bob Beck (beck (at) openbsd.org). 6 * 7 * Permission to use, copy, modify, and distribute this software for any 8 * purpose with or without fee is hereby granted, provided that the above 9 * copyright notice and this permission notice appear in all copies. 10 * 11 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES 12 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF 13 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR 14 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 15 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN 16 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF 17 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 18 */ 19 20 #include <sys/types.h> 21 #include <sys/file.h> 22 #include <sys/ioctl.h> 23 #include <sys/socket.h> 24 #include <sys/stat.h> 25 #include <sys/time.h> 26 #include <sys/wait.h> 27 28 #include <net/if.h> 29 #include <net/pfvar.h> 30 #include <arpa/inet.h> 31 32 #include <err.h> 33 #include <errno.h> 34 #include <login_cap.h> 35 #include <pwd.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(char *); 48 static int check_luser(char *, char *); 49 static int remove_stale_rulesets(void); 50 static int change_filter(int, const char *, const char *); 51 static int change_table(int, const char *); 52 static void authpf_kill_states(void); 53 54 int dev; /* pf device */ 55 char anchorname[PF_ANCHOR_NAME_SIZE] = "authpf"; 56 char rulesetname[MAXPATHLEN - PF_ANCHOR_NAME_SIZE - 2]; 57 char tablename[PF_TABLE_NAME_SIZE] = "authpf_users"; 58 59 FILE *pidfp; 60 char luser[MAXLOGNAME]; /* username */ 61 char ipsrc[256]; /* ip as a string */ 62 char pidfile[MAXPATHLEN]; /* we save pid in this file. */ 63 64 struct timeval Tstart, Tend; /* start and end times of session */ 65 66 volatile sig_atomic_t want_death; 67 static void need_death(int signo); 68 static __dead void do_death(int); 69 70 /* 71 * User shell for authenticating gateways. Sole purpose is to allow 72 * a user to ssh to a gateway, and have the gateway modify packet 73 * filters to allow access, then remove access when the user finishes 74 * up. Meant to be used only from ssh(1) connections. 75 */ 76 int 77 main(int argc, char *argv[]) 78 { 79 int lockcnt = 0, n, pidfd; 80 FILE *config; 81 struct in6_addr ina; 82 struct passwd *pw; 83 char *cp; 84 gid_t gid; 85 uid_t uid; 86 char *shell; 87 login_cap_t *lc; 88 89 config = fopen(PATH_CONFFILE, "r"); 90 if (config == NULL) { 91 syslog(LOG_ERR, "can not open %s (%m)", PATH_CONFFILE); 92 exit(1); 93 } 94 95 if ((cp = getenv("SSH_TTY")) == NULL) { 96 syslog(LOG_ERR, "non-interactive session connection for authpf"); 97 exit(1); 98 } 99 100 if ((cp = getenv("SSH_CLIENT")) == NULL) { 101 syslog(LOG_ERR, "cannot determine connection source"); 102 exit(1); 103 } 104 105 if (strlcpy(ipsrc, cp, sizeof(ipsrc)) >= sizeof(ipsrc)) { 106 syslog(LOG_ERR, "SSH_CLIENT variable too long"); 107 exit(1); 108 } 109 cp = strchr(ipsrc, ' '); 110 if (!cp) { 111 syslog(LOG_ERR, "corrupt SSH_CLIENT variable %s", ipsrc); 112 exit(1); 113 } 114 *cp = '\0'; 115 if (inet_pton(AF_INET, ipsrc, &ina) != 1 && 116 inet_pton(AF_INET6, ipsrc, &ina) != 1) { 117 syslog(LOG_ERR, 118 "cannot determine IP from SSH_CLIENT %s", ipsrc); 119 exit(1); 120 } 121 /* open the pf device */ 122 dev = open(PATH_DEVFILE, O_RDWR); 123 if (dev == -1) { 124 syslog(LOG_ERR, "cannot open packet filter device (%m)"); 125 goto die; 126 } 127 128 uid = getuid(); 129 pw = getpwuid(uid); 130 if (pw == NULL) { 131 syslog(LOG_ERR, "cannot find user for uid %u", uid); 132 goto die; 133 } 134 135 if ((lc = login_getclass(pw->pw_class)) != NULL) 136 shell = login_getcapstr(lc, "shell", pw->pw_shell, 137 pw->pw_shell); 138 else 139 shell = pw->pw_shell; 140 141 login_close(lc); 142 143 if (strcmp(shell, PATH_AUTHPF_SHELL)) { 144 syslog(LOG_ERR, "wrong shell for user %s, uid %u", 145 pw->pw_name, pw->pw_uid); 146 if (shell != pw->pw_shell) 147 free(shell); 148 goto die; 149 } 150 151 if (shell != pw->pw_shell) 152 free(shell); 153 154 /* 155 * Paranoia, but this data _does_ come from outside authpf, and 156 * truncation would be bad. 157 */ 158 if (strlcpy(luser, pw->pw_name, sizeof(luser)) >= sizeof(luser)) { 159 syslog(LOG_ERR, "username too long: %s", pw->pw_name); 160 goto die; 161 } 162 163 if ((n = snprintf(rulesetname, sizeof(rulesetname), "%s(%ld)", 164 luser, (long)getpid())) < 0 || (u_int)n >= sizeof(rulesetname)) { 165 syslog(LOG_INFO, "%s(%ld) too large, ruleset name will be %ld", 166 luser, (long)getpid(), (long)getpid()); 167 if ((n = snprintf(rulesetname, sizeof(rulesetname), "%ld", 168 (long)getpid())) < 0 || (u_int)n >= sizeof(rulesetname)) { 169 syslog(LOG_ERR, "pid too large for ruleset name"); 170 goto die; 171 } 172 } 173 174 175 /* Make our entry in /var/authpf as /var/authpf/ipaddr */ 176 n = snprintf(pidfile, sizeof(pidfile), "%s/%s", PATH_PIDFILE, ipsrc); 177 if (n < 0 || (u_int)n >= sizeof(pidfile)) { 178 syslog(LOG_ERR, "path to pidfile too long"); 179 goto die; 180 } 181 182 /* 183 * If someone else is already using this ip, then this person 184 * wants to switch users - so kill the old process and exit 185 * as well. 186 * 187 * Note, we could print a message and tell them to log out, but the 188 * usual case of this is that someone has left themselves logged in, 189 * with the authenticated connection iconized and someone else walks 190 * up to use and automatically logs in before using. If this just 191 * gets rid of the old one silently, the new user never knows they 192 * could have used someone else's old authentication. If we 193 * tell them to log out before switching users it is an invitation 194 * for abuse. 195 */ 196 197 do { 198 int save_errno, otherpid = -1; 199 char otherluser[MAXLOGNAME]; 200 201 if ((pidfd = open(pidfile, O_RDWR|O_CREAT, 0644)) == -1 || 202 (pidfp = fdopen(pidfd, "r+")) == NULL) { 203 if (pidfd != -1) 204 close(pidfd); 205 syslog(LOG_ERR, "cannot open or create %s: %s", pidfile, 206 strerror(errno)); 207 goto die; 208 } 209 210 if (flock(fileno(pidfp), LOCK_EX|LOCK_NB) == 0) 211 break; 212 save_errno = errno; 213 214 /* Mark our pid, and username to our file. */ 215 216 rewind(pidfp); 217 /* 31 == MAXLOGNAME - 1 */ 218 if (fscanf(pidfp, "%d\n%31s\n", &otherpid, otherluser) != 2) 219 otherpid = -1; 220 syslog(LOG_DEBUG, "tried to lock %s, in use by pid %d: %s", 221 pidfile, otherpid, strerror(save_errno)); 222 223 if (otherpid > 0) { 224 syslog(LOG_INFO, 225 "killing prior auth (pid %d) of %s by user %s", 226 otherpid, ipsrc, otherluser); 227 if (kill((pid_t) otherpid, SIGTERM) == -1) { 228 syslog(LOG_INFO, 229 "could not kill process %d: (%m)", 230 otherpid); 231 } 232 } 233 234 /* 235 * we try to kill the previous process and acquire the lock 236 * for 10 seconds, trying once a second. if we can't after 237 * 10 attempts we log an error and give up 238 */ 239 if (++lockcnt > 10) { 240 syslog(LOG_ERR, "cannot kill previous authpf (pid %d)", 241 otherpid); 242 fclose(pidfp); 243 pidfp = NULL; 244 goto dogdeath; 245 } 246 sleep(1); 247 248 /* re-open, and try again. The previous authpf process 249 * we killed above should unlink the file and release 250 * it's lock, giving us a chance to get it now 251 */ 252 fclose(pidfp); 253 pidfp = NULL; 254 } while (1); 255 256 /* whack the group list */ 257 gid = getegid(); 258 if (setgroups(1, &gid) == -1) { 259 syslog(LOG_INFO, "setgroups: %s", strerror(errno)); 260 do_death(0); 261 } 262 263 /* revoke privs */ 264 uid = getuid(); 265 #if defined(__OpenBSD__) 266 if (setresuid(uid, uid, uid) == -1) { 267 syslog(LOG_INFO, "setresuid: %s", strerror(errno)); 268 do_death(0); 269 } 270 #else /* defined(__OpenBSD__) */ 271 /* NetBSD */ 272 if (setuid(uid) == -1) { 273 syslog(LOG_INFO, "setresuid: %s", strerror(errno)); 274 do_death(0); 275 } 276 #endif /* defined(__OpenBSD__) */ 277 openlog("authpf", LOG_PID | LOG_NDELAY, LOG_DAEMON); 278 279 if (!check_luser(PATH_BAN_DIR, luser) || !allowed_luser(luser)) { 280 syslog(LOG_INFO, "user %s prohibited", luser); 281 do_death(0); 282 } 283 284 if (read_config(config)) { 285 syslog(LOG_ERR, "invalid config file %s", PATH_CONFFILE); 286 do_death(0); 287 } 288 289 if (remove_stale_rulesets()) { 290 syslog(LOG_INFO, "error removing stale rulesets"); 291 do_death(0); 292 } 293 294 /* We appear to be making headway, so actually mark our pid */ 295 rewind(pidfp); 296 fprintf(pidfp, "%ld\n%s\n", (long)getpid(), luser); 297 fflush(pidfp); 298 (void) ftruncate(fileno(pidfp), ftello(pidfp)); 299 300 if (change_filter(1, luser, ipsrc) == -1) { 301 printf("Unable to modify filters\r\n"); 302 do_death(0); 303 } 304 if (change_table(1, ipsrc) == -1) { 305 printf("Unable to modify table\r\n"); 306 change_filter(0, luser, ipsrc); 307 do_death(0); 308 } 309 310 signal(SIGTERM, need_death); 311 signal(SIGINT, need_death); 312 signal(SIGALRM, need_death); 313 signal(SIGPIPE, need_death); 314 signal(SIGHUP, need_death); 315 signal(SIGQUIT, need_death); 316 signal(SIGTSTP, need_death); 317 while (1) { 318 printf("\r\nHello %s. ", luser); 319 printf("You are authenticated from host \"%s\"\r\n", ipsrc); 320 setproctitle("%s@%s", luser, ipsrc); 321 print_message(PATH_MESSAGE); 322 while (1) { 323 sleep(10); 324 if (want_death) 325 do_death(1); 326 } 327 } 328 329 /* NOTREACHED */ 330 dogdeath: 331 printf("\r\n\r\nSorry, this service is currently unavailable due to "); 332 printf("technical difficulties\r\n\r\n"); 333 print_message(PATH_PROBLEM); 334 printf("\r\nYour authentication process (pid %ld) was unable to run\n", 335 (long)getpid()); 336 sleep(180); /* them lusers read reaaaaal slow */ 337 die: 338 do_death(0); 339 return (0); 340 } 341 342 /* 343 * reads config file in PATH_CONFFILE to set optional behaviours up 344 */ 345 static int 346 read_config(FILE *f) 347 { 348 char buf[1024]; 349 int i = 0; 350 351 do { 352 char **ap; 353 char *pair[4], *cp, *tp; 354 int len; 355 356 if (fgets(buf, sizeof(buf), f) == NULL) { 357 fclose(f); 358 return (0); 359 } 360 i++; 361 len = strlen(buf); 362 if (buf[len - 1] != '\n' && !feof(f)) { 363 syslog(LOG_ERR, "line %d too long in %s", i, 364 PATH_CONFFILE); 365 return (1); 366 } 367 buf[len - 1] = '\0'; 368 369 for (cp = buf; *cp == ' ' || *cp == '\t'; cp++) 370 ; /* nothing */ 371 372 if (!*cp || *cp == '#' || *cp == '\n') 373 continue; 374 375 for (ap = pair; ap < &pair[3] && 376 (*ap = strsep(&cp, "=")) != NULL; ) { 377 if (**ap != '\0') 378 ap++; 379 } 380 if (ap != &pair[2]) 381 goto parse_error; 382 383 tp = pair[1] + strlen(pair[1]); 384 while ((*tp == ' ' || *tp == '\t') && tp >= pair[1]) 385 *tp-- = '\0'; 386 387 if (strcasecmp(pair[0], "anchor") == 0) { 388 if (!pair[1][0] || strlcpy(anchorname, pair[1], 389 sizeof(anchorname)) >= sizeof(anchorname)) 390 goto parse_error; 391 } 392 if (strcasecmp(pair[0], "table") == 0) { 393 if (!pair[1][0] || strlcpy(tablename, pair[1], 394 sizeof(tablename)) >= sizeof(tablename)) 395 goto parse_error; 396 } 397 } while (!feof(f) && !ferror(f)); 398 fclose(f); 399 return (0); 400 401 parse_error: 402 fclose(f); 403 syslog(LOG_ERR, "parse error, line %d of %s", i, PATH_CONFFILE); 404 return (1); 405 } 406 407 408 /* 409 * splatter a file to stdout - max line length of 1024, 410 * used for spitting message files at users to tell them 411 * they've been bad or we're unavailable. 412 */ 413 static void 414 print_message(char *filename) 415 { 416 char buf[1024]; 417 FILE *f; 418 419 if ((f = fopen(filename, "r")) == NULL) 420 return; /* fail silently, we don't care if it isn't there */ 421 422 do { 423 if (fgets(buf, sizeof(buf), f) == NULL) { 424 fflush(stdout); 425 fclose(f); 426 return; 427 } 428 } while (fputs(buf, stdout) != EOF && !feof(f)); 429 fflush(stdout); 430 fclose(f); 431 } 432 433 /* 434 * allowed_luser checks to see if user "luser" is allowed to 435 * use this gateway by virtue of being listed in an allowed 436 * users file, namely /etc/authpf/authpf.allow . 437 * 438 * If /etc/authpf/authpf.allow does not exist, then we assume that 439 * all users who are allowed in by sshd(8) are permitted to 440 * use this gateway. If /etc/authpf/authpf.allow does exist, then a 441 * user must be listed if the connection is to continue, else 442 * the session terminates in the same manner as being banned. 443 */ 444 static int 445 allowed_luser(char *luser) 446 { 447 char *buf, *lbuf; 448 int matched; 449 size_t len; 450 FILE *f; 451 452 if ((f = fopen(PATH_ALLOWFILE, "r")) == NULL) { 453 if (errno == ENOENT) { 454 /* 455 * allowfile doesn't exist, thus this gateway 456 * isn't restricted to certain users... 457 */ 458 return (1); 459 } 460 461 /* 462 * luser may in fact be allowed, but we can't open 463 * the file even though it's there. probably a config 464 * problem. 465 */ 466 syslog(LOG_ERR, "cannot open allowed users file %s (%s)", 467 PATH_ALLOWFILE, strerror(errno)); 468 return (0); 469 } else { 470 /* 471 * /etc/authpf/authpf.allow exists, thus we do a linear 472 * search to see if they are allowed. 473 * also, if username "*" exists, then this is a 474 * "public" gateway, such as it is, so let 475 * everyone use it. 476 */ 477 lbuf = NULL; 478 while ((buf = fgetln(f, &len))) { 479 if (buf[len - 1] == '\n') 480 buf[len - 1] = '\0'; 481 else { 482 if ((lbuf = (char *)malloc(len + 1)) == NULL) 483 err(1, NULL); 484 memcpy(lbuf, buf, len); 485 lbuf[len] = '\0'; 486 buf = lbuf; 487 } 488 489 matched = strcmp(luser, buf) == 0 || strcmp("*", buf) == 0; 490 491 if (lbuf != NULL) { 492 free(lbuf); 493 lbuf = NULL; 494 } 495 496 if (matched) 497 return (1); /* matched an allowed username */ 498 } 499 syslog(LOG_INFO, "denied access to %s: not listed in %s", 500 luser, PATH_ALLOWFILE); 501 502 /* reuse buf */ 503 buf = "\n\nSorry, you are not allowed to use this facility!\n"; 504 fputs(buf, stdout); 505 } 506 fflush(stdout); 507 return (0); 508 } 509 510 /* 511 * check_luser checks to see if user "luser" has been banned 512 * from using us by virtue of having an file of the same name 513 * in the "luserdir" directory. 514 * 515 * If the user has been banned, we copy the contents of the file 516 * to the user's screen. (useful for telling the user what to 517 * do to get un-banned, or just to tell them they aren't 518 * going to be un-banned.) 519 */ 520 static int 521 check_luser(char *luserdir, char *luser) 522 { 523 FILE *f; 524 int n; 525 char tmp[MAXPATHLEN]; 526 527 n = snprintf(tmp, sizeof(tmp), "%s/%s", luserdir, luser); 528 if (n < 0 || (u_int)n >= sizeof(tmp)) { 529 syslog(LOG_ERR, "provided banned directory line too long (%s)", 530 luserdir); 531 return (0); 532 } 533 if ((f = fopen(tmp, "r")) == NULL) { 534 if (errno == ENOENT) { 535 /* 536 * file or dir doesn't exist, so therefore 537 * this luser isn't banned.. all is well 538 */ 539 return (1); 540 } else { 541 /* 542 * luser may in fact be banned, but we can't open the 543 * file even though it's there. probably a config 544 * problem. 545 */ 546 syslog(LOG_ERR, "cannot open banned file %s (%s)", 547 tmp, strerror(errno)); 548 return (0); 549 } 550 } else { 551 /* 552 * luser is banned - spit the file at them to 553 * tell what they can do and where they can go. 554 */ 555 syslog(LOG_INFO, "denied access to %s: %s exists", 556 luser, tmp); 557 558 /* reuse tmp */ 559 strlcpy(tmp, "\n\n-**- Sorry, you have been banned! -**-\n\n", 560 sizeof(tmp)); 561 while (fputs(tmp, stdout) != EOF && !feof(f)) { 562 if (fgets(tmp, sizeof(tmp), f) == NULL) { 563 fflush(stdout); 564 fclose(f); 565 return (0); 566 } 567 } 568 fclose(f); 569 } 570 fflush(stdout); 571 return (0); 572 } 573 574 /* 575 * Search for rulesets left by other authpf processes (either because they 576 * died ungracefully or were terminated) and remove them. 577 */ 578 static int 579 remove_stale_rulesets(void) 580 { 581 struct pfioc_ruleset prs; 582 u_int32_t nr, mnr; 583 584 memset(&prs, 0, sizeof(prs)); 585 strlcpy(prs.path, anchorname, sizeof(prs.path)); 586 if (ioctl(dev, DIOCGETRULESETS, &prs)) { 587 if (errno == EINVAL) 588 return (0); 589 else 590 return (1); 591 } 592 593 mnr = prs.nr; 594 nr = 0; 595 while (nr < mnr) { 596 char *s, *t; 597 pid_t pid; 598 599 prs.nr = nr; 600 if (ioctl(dev, DIOCGETRULESET, &prs)) 601 return (1); 602 errno = 0; 603 if ((t = strchr(prs.name, '(')) == NULL) 604 t = prs.name; 605 else 606 t++; 607 pid = strtoul(t, &s, 10); 608 if (!prs.name[0] || errno || 609 (*s && (t == prs.name || *s != ')'))) 610 return (1); 611 if (kill(pid, 0) && errno != EPERM) { 612 int i; 613 struct pfioc_trans_e t_e[PF_RULESET_MAX+1]; 614 struct pfioc_trans t; 615 616 bzero(&t, sizeof(t)); 617 bzero(t_e, sizeof(t_e)); 618 t.size = PF_RULESET_MAX+1; 619 t.esize = sizeof(t_e[0]); 620 t.array = t_e; 621 for (i = 0; i < PF_RULESET_MAX+1; ++i) { 622 t_e[i].rs_num = i; 623 snprintf(t_e[i].anchor, sizeof(t_e[i].anchor), 624 "%s/%s", anchorname, prs.name); 625 } 626 t_e[PF_RULESET_MAX].rs_num = PF_RULESET_TABLE; 627 if ((ioctl(dev, DIOCXBEGIN, &t) || 628 ioctl(dev, DIOCXCOMMIT, &t)) && 629 errno != EINVAL) 630 return (1); 631 mnr--; 632 } else 633 nr++; 634 } 635 return (0); 636 } 637 638 /* 639 * Add/remove filter entries for user "luser" from ip "ipsrc" 640 */ 641 static int 642 change_filter(int add, const char *luser, const char *ipsrc) 643 { 644 char *pargv[13] = { 645 "pfctl", "-p", "/dev/pf", "-q", "-a", "anchor/ruleset", 646 "-D", "user_ip=X", "-D", "user_id=X", "-f", 647 "file", NULL 648 }; 649 char *fdpath = NULL, *userstr = NULL, *ipstr = NULL; 650 char *rsn = NULL, *fn = NULL; 651 pid_t pid; 652 gid_t gid; 653 int s; 654 655 if (luser == NULL || !luser[0] || ipsrc == NULL || !ipsrc[0]) { 656 syslog(LOG_ERR, "invalid luser/ipsrc"); 657 goto error; 658 } 659 660 if (asprintf(&rsn, "%s/%s", anchorname, rulesetname) == -1) 661 goto no_mem; 662 if (asprintf(&fdpath, "/dev/fd/%d", dev) == -1) 663 goto no_mem; 664 if (asprintf(&ipstr, "user_ip=%s", ipsrc) == -1) 665 goto no_mem; 666 if (asprintf(&userstr, "user_id=%s", luser) == -1) 667 goto no_mem; 668 669 if (add) { 670 struct stat sb; 671 672 if (asprintf(&fn, "%s/%s/authpf.rules", PATH_USER_DIR, luser) 673 == -1) 674 goto no_mem; 675 if (stat(fn, &sb) == -1) { 676 free(fn); 677 if ((fn = strdup(PATH_PFRULES)) == NULL) 678 goto no_mem; 679 } 680 } 681 pargv[2] = fdpath; 682 pargv[5] = rsn; 683 pargv[7] = userstr; 684 pargv[9] = ipstr; 685 if (!add) 686 pargv[11] = "/dev/null"; 687 else 688 pargv[11] = fn; 689 690 switch (pid = fork()) { 691 case -1: 692 syslog(LOG_ERR, "fork failed"); 693 goto error; 694 case 0: 695 /* revoke group privs before exec */ 696 gid = getgid(); 697 if (setregid(gid, gid) == -1) { 698 err(1, "setregid"); 699 } 700 execvp(PATH_PFCTL, pargv); 701 warn("exec of %s failed", PATH_PFCTL); 702 _exit(1); 703 } 704 705 /* parent */ 706 waitpid(pid, &s, 0); 707 if (s != 0) { 708 syslog(LOG_ERR, "pfctl exited abnormally"); 709 goto error; 710 } 711 712 if (add) { 713 gettimeofday(&Tstart, NULL); 714 syslog(LOG_INFO, "allowing %s, user %s", ipsrc, luser); 715 } else { 716 gettimeofday(&Tend, NULL); 717 syslog(LOG_INFO, "removed %s, user %s - duration %lld seconds", 718 ipsrc, luser, (long long)(Tend.tv_sec - Tstart.tv_sec)); 719 } 720 return (0); 721 no_mem: 722 syslog(LOG_ERR, "malloc failed"); 723 error: 724 free(fdpath); 725 free(rsn); 726 free(userstr); 727 free(ipstr); 728 free(fn); 729 return (-1); 730 } 731 732 /* 733 * Add/remove this IP from the "authpf_users" table. 734 */ 735 static int 736 change_table(int add, const char *ipsrc) 737 { 738 struct pfioc_table io; 739 struct pfr_addr addr; 740 741 bzero(&io, sizeof(io)); 742 strlcpy(io.pfrio_table.pfrt_name, tablename, 743 sizeof(io.pfrio_table.pfrt_name)); 744 io.pfrio_buffer = &addr; 745 io.pfrio_esize = sizeof(addr); 746 io.pfrio_size = 1; 747 748 bzero(&addr, sizeof(addr)); 749 if (ipsrc == NULL || !ipsrc[0]) 750 return (-1); 751 if (inet_pton(AF_INET, ipsrc, &addr.pfra_ip4addr) == 1) { 752 addr.pfra_af = AF_INET; 753 addr.pfra_net = 32; 754 } else if (inet_pton(AF_INET6, ipsrc, &addr.pfra_ip6addr) == 1) { 755 addr.pfra_af = AF_INET6; 756 addr.pfra_net = 128; 757 } else { 758 syslog(LOG_ERR, "invalid ipsrc"); 759 return (-1); 760 } 761 762 if (ioctl(dev, add ? DIOCRADDADDRS : DIOCRDELADDRS, &io) && 763 errno != ESRCH) { 764 syslog(LOG_ERR, "cannot %s %s from table %s: %s", 765 add ? "add" : "remove", ipsrc, tablename, 766 strerror(errno)); 767 return (-1); 768 } 769 return (0); 770 } 771 772 /* 773 * This is to kill off states that would otherwise be left behind stateful 774 * rules. This means we don't need to allow in more traffic than we really 775 * want to, since we don't have to worry about any luser sessions lasting 776 * longer than their ssh session. This function is based on 777 * pfctl_kill_states from pfctl. 778 */ 779 static void 780 authpf_kill_states(void) 781 { 782 struct pfioc_state_kill psk; 783 struct pf_addr target; 784 785 memset(&psk, 0, sizeof(psk)); 786 memset(&target, 0, sizeof(target)); 787 788 if (inet_pton(AF_INET, ipsrc, &target.v4) == 1) 789 psk.psk_af = AF_INET; 790 else if (inet_pton(AF_INET6, ipsrc, &target.v6) == 1) 791 psk.psk_af = AF_INET6; 792 else { 793 syslog(LOG_ERR, "inet_pton(%s) failed", ipsrc); 794 return; 795 } 796 797 /* Kill all states from ipsrc */ 798 memcpy(&psk.psk_src.addr.v.a.addr, &target, 799 sizeof(psk.psk_src.addr.v.a.addr)); 800 memset(&psk.psk_src.addr.v.a.mask, 0xff, 801 sizeof(psk.psk_src.addr.v.a.mask)); 802 if (ioctl(dev, DIOCKILLSTATES, &psk)) 803 syslog(LOG_ERR, "DIOCKILLSTATES failed (%m)"); 804 805 /* Kill all states to ipsrc */ 806 memset(&psk.psk_src, 0, sizeof(psk.psk_src)); 807 memcpy(&psk.psk_dst.addr.v.a.addr, &target, 808 sizeof(psk.psk_dst.addr.v.a.addr)); 809 memset(&psk.psk_dst.addr.v.a.mask, 0xff, 810 sizeof(psk.psk_dst.addr.v.a.mask)); 811 if (ioctl(dev, DIOCKILLSTATES, &psk)) 812 syslog(LOG_ERR, "DIOCKILLSTATES failed (%m)"); 813 } 814 815 /* signal handler that makes us go away properly */ 816 static void 817 need_death(int signo) 818 { 819 want_death = 1; 820 } 821 822 /* 823 * function that removes our stuff when we go away. 824 */ 825 static __dead void 826 do_death(int active) 827 { 828 int ret = 0; 829 830 if (active) { 831 change_filter(0, luser, ipsrc); 832 change_table(0, ipsrc); 833 authpf_kill_states(); 834 remove_stale_rulesets(); 835 } 836 if (pidfile[0] && (pidfp != NULL)) 837 if (unlink(pidfile) == -1) 838 syslog(LOG_ERR, "cannot unlink %s (%m)", pidfile); 839 exit(ret); 840 } 841
Indexes created Sat Sep 20 22:09:52 GMT 2025