1 /* $OpenBSD: authpf.c,v 1.89 2005/02/10 04:24:15 joel Exp $ */ 2 3 /* 4 * Copyright (C) 1998 - 2002 Bob Beck (beck@openbsd.org). 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 16 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 18 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 25 * SUCH DAMAGE. 26 */ 27 28 #include <sys/cdefs.h> 29 __FBSDID("$FreeBSD$"); 30 31 #include <sys/param.h> 32 #include <sys/file.h> 33 #include <sys/ioctl.h> 34 #include <sys/socket.h> 35 #include <sys/stat.h> 36 #include <sys/time.h> 37 #include <sys/wait.h> 38 39 #include <net/if.h> 40 #include <net/pfvar.h> 41 #include <arpa/inet.h> 42 43 #include <err.h> 44 #include <errno.h> 45 #include <login_cap.h> 46 #include <pwd.h> 47 #include <signal.h> 48 #include <stdio.h> 49 #include <stdlib.h> 50 #include <string.h> 51 #include <syslog.h> 52 #include <unistd.h> 53 54 #include "pathnames.h" 55 56 extern int symset(const char *, const char *, int); 57 58 static int read_config(FILE *); 59 static void print_message(char *); 60 static int allowed_luser(char *); 61 static int check_luser(char *, char *); 62 static int remove_stale_rulesets(void); 63 static int change_filter(int, const char *, const char *); 64 static int change_table(int, const char *, const char *); 65 static void authpf_kill_states(void); 66 67 int dev; /* pf device */ 68 char anchorname[PF_ANCHOR_NAME_SIZE] = "authpf"; 69 char rulesetname[MAXPATHLEN - PF_ANCHOR_NAME_SIZE - 2]; 70 char tablename[PF_TABLE_NAME_SIZE] = "authpf_users"; 71 72 FILE *pidfp; 73 char *infile; /* file name printed by yyerror() in parse.y */ 74 char luser[MAXLOGNAME]; /* username */ 75 char ipsrc[256]; /* ip as a string */ 76 char pidfile[MAXPATHLEN]; /* we save pid in this file. */ 77 78 struct timeval Tstart, Tend; /* start and end times of session */ 79 80 volatile sig_atomic_t want_death; 81 static void need_death(int signo); 82 #ifdef __FreeBSD__ 83 static __dead2 void do_death(int); 84 #else 85 static __dead void do_death(int); 86 #endif 87 88 /* 89 * User shell for authenticating gateways. Sole purpose is to allow 90 * a user to ssh to a gateway, and have the gateway modify packet 91 * filters to allow access, then remove access when the user finishes 92 * up. Meant to be used only from ssh(1) connections. 93 */ 94 int 95 main(int argc, char *argv[]) 96 { 97 int lockcnt = 0, n, pidfd; 98 FILE *config; 99 struct in6_addr ina; 100 struct passwd *pw; 101 char *cp; 102 uid_t uid; 103 char *shell; 104 login_cap_t *lc; 105 106 config = fopen(PATH_CONFFILE, "r"); 107 108 if ((cp = getenv("SSH_TTY")) == NULL) { 109 syslog(LOG_ERR, "non-interactive session connection for authpf"); 110 exit(1); 111 } 112 113 if ((cp = getenv("SSH_CLIENT")) == NULL) { 114 syslog(LOG_ERR, "cannot determine connection source"); 115 exit(1); 116 } 117 118 if (strlcpy(ipsrc, cp, sizeof(ipsrc)) >= sizeof(ipsrc)) { 119 syslog(LOG_ERR, "SSH_CLIENT variable too long"); 120 exit(1); 121 } 122 cp = strchr(ipsrc, ' '); 123 if (!cp) { 124 syslog(LOG_ERR, "corrupt SSH_CLIENT variable %s", ipsrc); 125 exit(1); 126 } 127 *cp = '\0'; 128 if (inet_pton(AF_INET, ipsrc, &ina) != 1 && 129 inet_pton(AF_INET6, ipsrc, &ina) != 1) { 130 syslog(LOG_ERR, 131 "cannot determine IP from SSH_CLIENT %s", ipsrc); 132 exit(1); 133 } 134 /* open the pf device */ 135 dev = open(PATH_DEVFILE, O_RDWR); 136 if (dev == -1) { 137 syslog(LOG_ERR, "cannot open packet filter device (%m)"); 138 goto die; 139 } 140 141 uid = getuid(); 142 pw = getpwuid(uid); 143 endpwent(); 144 if (pw == NULL) { 145 syslog(LOG_ERR, "cannot find user for uid %u", uid); 146 goto die; 147 } 148 149 if ((lc = login_getclass(pw->pw_class)) != NULL) 150 shell = (char *)login_getcapstr(lc, "shell", pw->pw_shell, 151 pw->pw_shell); 152 else 153 shell = pw->pw_shell; 154 155 login_close(lc); 156 157 if (strcmp(shell, PATH_AUTHPF_SHELL)) { 158 syslog(LOG_ERR, "wrong shell for user %s, uid %u", 159 pw->pw_name, pw->pw_uid); 160 if (shell != pw->pw_shell) 161 free(shell); 162 goto die; 163 } 164 165 if (shell != pw->pw_shell) 166 free(shell); 167 168 /* 169 * Paranoia, but this data _does_ come from outside authpf, and 170 * truncation would be bad. 171 */ 172 if (strlcpy(luser, pw->pw_name, sizeof(luser)) >= sizeof(luser)) { 173 syslog(LOG_ERR, "username too long: %s", pw->pw_name); 174 goto die; 175 } 176 177 if ((n = snprintf(rulesetname, sizeof(rulesetname), "%s(%ld)", 178 luser, (long)getpid())) < 0 || (u_int)n >= sizeof(rulesetname)) { 179 syslog(LOG_INFO, "%s(%ld) too large, ruleset name will be %ld", 180 luser, (long)getpid(), (long)getpid()); 181 if ((n = snprintf(rulesetname, sizeof(rulesetname), "%ld", 182 (long)getpid())) < 0 || (u_int)n >= sizeof(rulesetname)) { 183 syslog(LOG_ERR, "pid too large for ruleset name"); 184 goto die; 185 } 186 } 187 188 189 /* Make our entry in /var/authpf as /var/authpf/ipaddr */ 190 n = snprintf(pidfile, sizeof(pidfile), "%s/%s", PATH_PIDFILE, ipsrc); 191 if (n < 0 || (u_int)n >= sizeof(pidfile)) { 192 syslog(LOG_ERR, "path to pidfile too long"); 193 goto die; 194 } 195 196 /* 197 * If someone else is already using this ip, then this person 198 * wants to switch users - so kill the old process and exit 199 * as well. 200 * 201 * Note, we could print a message and tell them to log out, but the 202 * usual case of this is that someone has left themselves logged in, 203 * with the authenticated connection iconized and someone else walks 204 * up to use and automatically logs in before using. If this just 205 * gets rid of the old one silently, the new user never knows they 206 * could have used someone else's old authentication. If we 207 * tell them to log out before switching users it is an invitation 208 * for abuse. 209 */ 210 211 do { 212 int save_errno, otherpid = -1; 213 char otherluser[MAXLOGNAME]; 214 215 if ((pidfd = open(pidfile, O_RDWR|O_CREAT, 0644)) == -1 || 216 (pidfp = fdopen(pidfd, "r+")) == NULL) { 217 if (pidfd != -1) 218 close(pidfd); 219 syslog(LOG_ERR, "cannot open or create %s: %s", pidfile, 220 strerror(errno)); 221 goto die; 222 } 223 224 if (flock(fileno(pidfp), LOCK_EX|LOCK_NB) == 0) 225 break; 226 save_errno = errno; 227 228 /* Mark our pid, and username to our file. */ 229 230 rewind(pidfp); 231 /* 31 == MAXLOGNAME - 1 */ 232 if (fscanf(pidfp, "%d\n%31s\n", &otherpid, otherluser) != 2) 233 otherpid = -1; 234 syslog(LOG_DEBUG, "tried to lock %s, in use by pid %d: %s", 235 pidfile, otherpid, strerror(save_errno)); 236 237 if (otherpid > 0) { 238 syslog(LOG_INFO, 239 "killing prior auth (pid %d) of %s by user %s", 240 otherpid, ipsrc, otherluser); 241 if (kill((pid_t) otherpid, SIGTERM) == -1) { 242 syslog(LOG_INFO, 243 "could not kill process %d: (%m)", 244 otherpid); 245 } 246 } 247 248 /* 249 * we try to kill the previous process and acquire the lock 250 * for 10 seconds, trying once a second. if we can't after 251 * 10 attempts we log an error and give up 252 */ 253 if (++lockcnt > 10) { 254 syslog(LOG_ERR, "cannot kill previous authpf (pid %d)", 255 otherpid); 256 goto dogdeath; 257 } 258 sleep(1); 259 260 /* re-open, and try again. The previous authpf process 261 * we killed above should unlink the file and release 262 * it's lock, giving us a chance to get it now 263 */ 264 fclose(pidfp); 265 } while (1); 266 267 /* revoke privs */ 268 seteuid(getuid()); 269 setuid(getuid()); 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 (config == NULL || read_config(config)) { 279 syslog(LOG_INFO, "bad or nonexistent %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 (void) ftruncate(fileno(pidfp), ftello(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, luser, 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(SIGSTOP, 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 /* NOTREACHED */ 335 } 336 337 /* 338 * reads config file in PATH_CONFFILE to set optional behaviours up 339 */ 340 static int 341 read_config(FILE *f) 342 { 343 char buf[1024]; 344 int i = 0; 345 346 do { 347 char **ap; 348 char *pair[4], *cp, *tp; 349 int len; 350 351 if (fgets(buf, sizeof(buf), f) == NULL) { 352 fclose(f); 353 return (0); 354 } 355 i++; 356 len = strlen(buf); 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(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(char *luser) 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 * luser 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(luser, 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 luser, PATH_ALLOWFILE); 496 497 /* reuse buf */ 498 buf = "\n\nSorry, you are not allowed to use this facility!\n"; 499 fputs(buf, 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(char *luserdir, char *luser) 517 { 518 FILE *f; 519 int n; 520 char tmp[MAXPATHLEN]; 521 522 n = snprintf(tmp, sizeof(tmp), "%s/%s", luserdir, luser); 523 if (n < 0 || (u_int)n >= sizeof(tmp)) { 524 syslog(LOG_ERR, "provided banned directory line too long (%s)", 525 luserdir); 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 * luser 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 * luser 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 return (0); 560 } 561 } 562 } 563 fflush(stdout); 564 return (0); 565 } 566 567 /* 568 * Search for rulesets left by other authpf processes (either because they 569 * died ungracefully or were terminated) and remove them. 570 */ 571 static int 572 remove_stale_rulesets(void) 573 { 574 struct pfioc_ruleset prs; 575 u_int32_t nr, mnr; 576 577 memset(&prs, 0, sizeof(prs)); 578 strlcpy(prs.path, anchorname, sizeof(prs.path)); 579 if (ioctl(dev, DIOCGETRULESETS, &prs)) { 580 if (errno == EINVAL) 581 return (0); 582 else 583 return (1); 584 } 585 586 mnr = prs.nr; 587 nr = 0; 588 while (nr < mnr) { 589 char *s, *t; 590 pid_t pid; 591 592 prs.nr = nr; 593 if (ioctl(dev, DIOCGETRULESET, &prs)) 594 return (1); 595 errno = 0; 596 if ((t = strchr(prs.name, '(')) == NULL) 597 t = prs.name; 598 else 599 t++; 600 pid = strtoul(t, &s, 10); 601 if (!prs.name[0] || errno || 602 (*s && (t == prs.name || *s != ')'))) 603 return (1); 604 if (kill(pid, 0) && errno != EPERM) { 605 int i; 606 struct pfioc_trans_e t_e[PF_RULESET_MAX+1]; 607 struct pfioc_trans t; 608 609 bzero(&t, sizeof(t)); 610 bzero(t_e, sizeof(t_e)); 611 t.size = PF_RULESET_MAX+1; 612 t.esize = sizeof(t_e[0]); 613 t.array = t_e; 614 for (i = 0; i < PF_RULESET_MAX+1; ++i) { 615 t_e[i].rs_num = i; 616 snprintf(t_e[i].anchor, sizeof(t_e[i].anchor), 617 "%s/%s", anchorname, prs.name); 618 } 619 t_e[PF_RULESET_MAX].rs_num = PF_RULESET_TABLE; 620 if ((ioctl(dev, DIOCXBEGIN, &t) || 621 ioctl(dev, DIOCXCOMMIT, &t)) && 622 errno != EINVAL) 623 return (1); 624 mnr--; 625 } else 626 nr++; 627 } 628 return (0); 629 } 630 631 /* 632 * Add/remove filter entries for user "luser" from ip "ipsrc" 633 */ 634 static int 635 change_filter(int add, const char *luser, const char *ipsrc) 636 { 637 char *pargv[13] = { 638 "pfctl", "-p", "/dev/pf", "-q", "-a", "anchor/ruleset", 639 "-D", "user_ip=X", "-D", "user_id=X", "-f", 640 "file", NULL 641 }; 642 char *fdpath = NULL, *userstr = NULL, *ipstr = NULL; 643 char *rsn = NULL, *fn = NULL; 644 pid_t pid; 645 int s; 646 647 if (luser == NULL || !luser[0] || ipsrc == NULL || !ipsrc[0]) { 648 syslog(LOG_ERR, "invalid luser/ipsrc"); 649 goto error; 650 } 651 652 if (asprintf(&rsn, "%s/%s", anchorname, rulesetname) == -1) 653 goto no_mem; 654 if (asprintf(&fdpath, "/dev/fd/%d", dev) == -1) 655 goto no_mem; 656 if (asprintf(&ipstr, "user_ip=%s", ipsrc) == -1) 657 goto no_mem; 658 if (asprintf(&userstr, "user_id=%s", luser) == -1) 659 goto no_mem; 660 661 if (add) { 662 struct stat sb; 663 664 if (asprintf(&fn, "%s/%s/authpf.rules", PATH_USER_DIR, luser) 665 == -1) 666 goto no_mem; 667 if (stat(fn, &sb) == -1) { 668 free(fn); 669 if ((fn = strdup(PATH_PFRULES)) == NULL) 670 goto no_mem; 671 } 672 } 673 pargv[2] = fdpath; 674 pargv[5] = rsn; 675 pargv[7] = userstr; 676 pargv[9] = ipstr; 677 if (!add) 678 pargv[11] = "/dev/null"; 679 else 680 pargv[11] = fn; 681 682 switch (pid = fork()) { 683 case -1: 684 err(1, "fork failed"); 685 case 0: 686 execvp(PATH_PFCTL, pargv); 687 warn("exec of %s failed", PATH_PFCTL); 688 _exit(1); 689 } 690 691 /* parent */ 692 waitpid(pid, &s, 0); 693 if (s != 0) { 694 if (WIFEXITED(s)) { 695 syslog(LOG_ERR, "pfctl exited abnormally"); 696 goto error; 697 } 698 } 699 700 if (add) { 701 gettimeofday(&Tstart, NULL); 702 syslog(LOG_INFO, "allowing %s, user %s", ipsrc, luser); 703 } else { 704 gettimeofday(&Tend, NULL); 705 syslog(LOG_INFO, "removed %s, user %s - duration %ld seconds", 706 ipsrc, luser, Tend.tv_sec - Tstart.tv_sec); 707 } 708 return (0); 709 no_mem: 710 syslog(LOG_ERR, "malloc failed"); 711 error: 712 free(fdpath); 713 fdpath = NULL; 714 free(rsn); 715 rsn = NULL; 716 free(userstr); 717 userstr = NULL; 718 free(ipstr); 719 ipstr = NULL; 720 free(fn); 721 fn = NULL; 722 infile = NULL; 723 return (-1); 724 } 725 726 /* 727 * Add/remove this IP from the "authpf_users" table. 728 */ 729 static int 730 change_table(int add, const char *luser, const char *ipsrc) 731 { 732 struct pfioc_table io; 733 struct pfr_addr addr; 734 735 bzero(&io, sizeof(io)); 736 strlcpy(io.pfrio_table.pfrt_name, tablename, sizeof(io.pfrio_table)); 737 io.pfrio_buffer = &addr; 738 io.pfrio_esize = sizeof(addr); 739 io.pfrio_size = 1; 740 741 bzero(&addr, sizeof(addr)); 742 if (ipsrc == NULL || !ipsrc[0]) 743 return (-1); 744 if (inet_pton(AF_INET, ipsrc, &addr.pfra_ip4addr) == 1) { 745 addr.pfra_af = AF_INET; 746 addr.pfra_net = 32; 747 } else if (inet_pton(AF_INET6, ipsrc, &addr.pfra_ip6addr) == 1) { 748 addr.pfra_af = AF_INET6; 749 addr.pfra_net = 128; 750 } else { 751 syslog(LOG_ERR, "invalid ipsrc"); 752 return (-1); 753 } 754 755 if (ioctl(dev, add ? DIOCRADDADDRS : DIOCRDELADDRS, &io) && 756 errno != ESRCH) { 757 syslog(LOG_ERR, "cannot %s %s from table %s: %s", 758 add ? "add" : "remove", ipsrc, tablename, 759 strerror(errno)); 760 return (-1); 761 } 762 return (0); 763 } 764 765 /* 766 * This is to kill off states that would otherwise be left behind stateful 767 * rules. This means we don't need to allow in more traffic than we really 768 * want to, since we don't have to worry about any luser sessions lasting 769 * longer than their ssh session. This function is based on 770 * pfctl_kill_states from pfctl. 771 */ 772 static void 773 authpf_kill_states(void) 774 { 775 struct pfioc_state_kill psk; 776 struct pf_addr target; 777 778 memset(&psk, 0, sizeof(psk)); 779 memset(&target, 0, sizeof(target)); 780 781 if (inet_pton(AF_INET, ipsrc, &target.v4) == 1) 782 psk.psk_af = AF_INET; 783 else if (inet_pton(AF_INET6, ipsrc, &target.v6) == 1) 784 psk.psk_af = AF_INET6; 785 else { 786 syslog(LOG_ERR, "inet_pton(%s) failed", ipsrc); 787 return; 788 } 789 790 /* Kill all states from ipsrc */ 791 memcpy(&psk.psk_src.addr.v.a.addr, &target, 792 sizeof(psk.psk_src.addr.v.a.addr)); 793 memset(&psk.psk_src.addr.v.a.mask, 0xff, 794 sizeof(psk.psk_src.addr.v.a.mask)); 795 if (ioctl(dev, DIOCKILLSTATES, &psk)) 796 syslog(LOG_ERR, "DIOCKILLSTATES failed (%m)"); 797 798 /* Kill all states to ipsrc */ 799 memset(&psk.psk_src, 0, sizeof(psk.psk_src)); 800 memcpy(&psk.psk_dst.addr.v.a.addr, &target, 801 sizeof(psk.psk_dst.addr.v.a.addr)); 802 memset(&psk.psk_dst.addr.v.a.mask, 0xff, 803 sizeof(psk.psk_dst.addr.v.a.mask)); 804 if (ioctl(dev, DIOCKILLSTATES, &psk)) 805 syslog(LOG_ERR, "DIOCKILLSTATES failed (%m)"); 806 } 807 808 /* signal handler that makes us go away properly */ 809 static void 810 need_death(int signo) 811 { 812 want_death = 1; 813 } 814 815 /* 816 * function that removes our stuff when we go away. 817 */ 818 #ifdef __FreeBSD__ 819 static __dead2 void 820 #else 821 static __dead void 822 #endif 823 do_death(int active) 824 { 825 int ret = 0; 826 827 if (active) { 828 change_filter(0, luser, ipsrc); 829 change_table(0, luser, ipsrc); 830 authpf_kill_states(); 831 remove_stale_rulesets(); 832 } 833 if (pidfp) 834 ftruncate(fileno(pidfp), 0); 835 if (pidfile[0]) 836 if (unlink(pidfile) == -1) 837 syslog(LOG_ERR, "cannot unlink %s (%m)", pidfile); 838 exit(ret); 839 } 840