1 /* $NetBSD: authpf.c,v 1.4 2005/07/01 12:43:50 peter Exp $ */ 2 /* $OpenBSD: authpf.c,v 1.89 2005/02/10 04:24:15 joel Exp $ */ 3 4 /* 5 * Copyright (C) 1998 - 2002 Bob Beck (beck@openbsd.org). 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26 * SUCH DAMAGE. 27 */ 28 29 #include <sys/types.h> 30 #include <sys/file.h> 31 #include <sys/ioctl.h> 32 #include <sys/socket.h> 33 #include <sys/stat.h> 34 #include <sys/time.h> 35 #include <sys/wait.h> 36 37 #include <net/if.h> 38 #include <netinet/in.h> 39 #include <net/pfvar.h> 40 #include <arpa/inet.h> 41 42 #include <err.h> 43 #include <errno.h> 44 #include <login_cap.h> 45 #include <pwd.h> 46 #include <signal.h> 47 #include <stdio.h> 48 #include <stdlib.h> 49 #include <string.h> 50 #include <syslog.h> 51 #include <unistd.h> 52 53 #include "pathnames.h" 54 55 extern int symset(const char *, const char *, int); 56 57 static int read_config(FILE *); 58 static void print_message(char *); 59 static int allowed_luser(char *); 60 static int check_luser(char *, char *); 61 static int remove_stale_rulesets(void); 62 static int change_filter(int, const char *, const char *); 63 static int change_table(int, const char *, const char *); 64 static void authpf_kill_states(void); 65 66 int dev; /* pf device */ 67 char anchorname[PF_ANCHOR_NAME_SIZE] = "authpf"; 68 char rulesetname[MAXPATHLEN - PF_ANCHOR_NAME_SIZE - 2]; 69 char tablename[PF_TABLE_NAME_SIZE] = "authpf_users"; 70 71 FILE *pidfp; 72 char *infile; /* file name printed by yyerror() in parse.y */ 73 char luser[MAXLOGNAME]; /* username */ 74 char ipsrc[256]; /* ip as a string */ 75 char pidfile[MAXPATHLEN]; /* we save pid in this file. */ 76 77 struct timeval Tstart, Tend; /* start and end times of session */ 78 79 volatile sig_atomic_t want_death; 80 static void need_death(int signo); 81 static __dead void do_death(int); 82 83 /* 84 * User shell for authenticating gateways. Sole purpose is to allow 85 * a user to ssh to a gateway, and have the gateway modify packet 86 * filters to allow access, then remove access when the user finishes 87 * up. Meant to be used only from ssh(1) connections. 88 */ 89 int 90 main(int argc, char *argv[]) 91 { 92 int lockcnt = 0, n, pidfd; 93 FILE *config; 94 struct in6_addr ina; 95 struct passwd *pw; 96 char *cp; 97 uid_t uid; 98 char *shell; 99 login_cap_t *lc; 100 101 config = fopen(PATH_CONFFILE, "r"); 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 endpwent(); 139 if (pw == NULL) { 140 syslog(LOG_ERR, "cannot find user for uid %u", uid); 141 goto die; 142 } 143 144 if ((lc = login_getclass(pw->pw_class)) != NULL) 145 shell = login_getcapstr(lc, "shell", pw->pw_shell, 146 pw->pw_shell); 147 else 148 shell = pw->pw_shell; 149 150 login_close(lc); 151 152 if (strcmp(shell, PATH_AUTHPF_SHELL)) { 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 /var/authpf/ipaddr */ 185 n = snprintf(pidfile, sizeof(pidfile), "%s/%s", PATH_PIDFILE, ipsrc); 186 if (n < 0 || (u_int)n >= sizeof(pidfile)) { 187 syslog(LOG_ERR, "path to pidfile too long"); 188 goto die; 189 } 190 191 /* 192 * If someone else is already using this ip, then this person 193 * wants to switch users - so kill the old process and exit 194 * as well. 195 * 196 * Note, we could print a message and tell them to log out, but the 197 * usual case of this is that someone has left themselves logged in, 198 * with the authenticated connection iconized and someone else walks 199 * up to use and automatically logs in before using. If this just 200 * gets rid of the old one silently, the new user never knows they 201 * could have used someone else's old authentication. If we 202 * tell them to log out before switching users it is an invitation 203 * for abuse. 204 */ 205 206 do { 207 int save_errno, otherpid = -1; 208 char otherluser[MAXLOGNAME]; 209 210 if ((pidfd = open(pidfile, O_RDWR|O_CREAT, 0644)) == -1 || 211 (pidfp = fdopen(pidfd, "r+")) == NULL) { 212 if (pidfd != -1) 213 close(pidfd); 214 syslog(LOG_ERR, "cannot open or create %s: %s", pidfile, 215 strerror(errno)); 216 goto die; 217 } 218 219 if (flock(fileno(pidfp), LOCK_EX|LOCK_NB) == 0) 220 break; 221 save_errno = errno; 222 223 /* Mark our pid, and username to our file. */ 224 225 rewind(pidfp); 226 /* 31 == MAXLOGNAME - 1 */ 227 if (fscanf(pidfp, "%d\n%31s\n", &otherpid, otherluser) != 2) 228 otherpid = -1; 229 syslog(LOG_DEBUG, "tried to lock %s, in use by pid %d: %s", 230 pidfile, otherpid, strerror(save_errno)); 231 232 if (otherpid > 0) { 233 syslog(LOG_INFO, 234 "killing prior auth (pid %d) of %s by user %s", 235 otherpid, ipsrc, otherluser); 236 if (kill((pid_t) otherpid, SIGTERM) == -1) { 237 syslog(LOG_INFO, 238 "could not kill process %d: (%m)", 239 otherpid); 240 } 241 } 242 243 /* 244 * we try to kill the previous process and acquire the lock 245 * for 10 seconds, trying once a second. if we can't after 246 * 10 attempts we log an error and give up 247 */ 248 if (++lockcnt > 10) { 249 syslog(LOG_ERR, "cannot kill previous authpf (pid %d)", 250 otherpid); 251 goto dogdeath; 252 } 253 sleep(1); 254 255 /* re-open, and try again. The previous authpf process 256 * we killed above should unlink the file and release 257 * it's lock, giving us a chance to get it now 258 */ 259 fclose(pidfp); 260 } while (1); 261 262 /* revoke privs */ 263 seteuid(getuid()); 264 setuid(getuid()); 265 266 openlog("authpf", LOG_PID | LOG_NDELAY, LOG_DAEMON); 267 268 if (!check_luser(PATH_BAN_DIR, luser) || !allowed_luser(luser)) { 269 syslog(LOG_INFO, "user %s prohibited", luser); 270 do_death(0); 271 } 272 273 if (config == NULL || read_config(config)) { 274 syslog(LOG_INFO, "bad or nonexistent %s", PATH_CONFFILE); 275 do_death(0); 276 } 277 278 if (remove_stale_rulesets()) { 279 syslog(LOG_INFO, "error removing stale rulesets"); 280 do_death(0); 281 } 282 283 /* We appear to be making headway, so actually mark our pid */ 284 rewind(pidfp); 285 fprintf(pidfp, "%ld\n%s\n", (long)getpid(), luser); 286 fflush(pidfp); 287 (void) ftruncate(fileno(pidfp), ftello(pidfp)); 288 289 if (change_filter(1, luser, ipsrc) == -1) { 290 printf("Unable to modify filters\r\n"); 291 do_death(0); 292 } 293 if (change_table(1, luser, ipsrc) == -1) { 294 printf("Unable to modify table\r\n"); 295 change_filter(0, luser, ipsrc); 296 do_death(0); 297 } 298 299 signal(SIGTERM, need_death); 300 signal(SIGINT, need_death); 301 signal(SIGALRM, need_death); 302 signal(SIGPIPE, need_death); 303 signal(SIGHUP, need_death); 304 signal(SIGSTOP, need_death); 305 signal(SIGTSTP, need_death); 306 while (1) { 307 printf("\r\nHello %s. ", luser); 308 printf("You are authenticated from host \"%s\"\r\n", ipsrc); 309 setproctitle("%s@%s", luser, ipsrc); 310 print_message(PATH_MESSAGE); 311 while (1) { 312 sleep(10); 313 if (want_death) 314 do_death(1); 315 } 316 } 317 318 /* NOTREACHED */ 319 dogdeath: 320 printf("\r\n\r\nSorry, this service is currently unavailable due to "); 321 printf("technical difficulties\r\n\r\n"); 322 print_message(PATH_PROBLEM); 323 printf("\r\nYour authentication process (pid %ld) was unable to run\n", 324 (long)getpid()); 325 sleep(180); /* them lusers read reaaaaal slow */ 326 die: 327 do_death(0); 328 return (0); 329 } 330 331 /* 332 * reads config file in PATH_CONFFILE to set optional behaviours up 333 */ 334 static int 335 read_config(FILE *f) 336 { 337 char buf[1024]; 338 int i = 0; 339 340 do { 341 char **ap; 342 char *pair[4], *cp, *tp; 343 int len; 344 345 if (fgets(buf, sizeof(buf), f) == NULL) { 346 fclose(f); 347 return (0); 348 } 349 i++; 350 len = strlen(buf); 351 if (buf[len - 1] != '\n' && !feof(f)) { 352 syslog(LOG_ERR, "line %d too long in %s", i, 353 PATH_CONFFILE); 354 return (1); 355 } 356 buf[len - 1] = '\0'; 357 358 for (cp = buf; *cp == ' ' || *cp == '\t'; cp++) 359 ; /* nothing */ 360 361 if (!*cp || *cp == '#' || *cp == '\n') 362 continue; 363 364 for (ap = pair; ap < &pair[3] && 365 (*ap = strsep(&cp, "=")) != NULL; ) { 366 if (**ap != '\0') 367 ap++; 368 } 369 if (ap != &pair[2]) 370 goto parse_error; 371 372 tp = pair[1] + strlen(pair[1]); 373 while ((*tp == ' ' || *tp == '\t') && tp >= pair[1]) 374 *tp-- = '\0'; 375 376 if (strcasecmp(pair[0], "anchor") == 0) { 377 if (!pair[1][0] || strlcpy(anchorname, pair[1], 378 sizeof(anchorname)) >= sizeof(anchorname)) 379 goto parse_error; 380 } 381 if (strcasecmp(pair[0], "table") == 0) { 382 if (!pair[1][0] || strlcpy(tablename, pair[1], 383 sizeof(tablename)) >= sizeof(tablename)) 384 goto parse_error; 385 } 386 } while (!feof(f) && !ferror(f)); 387 fclose(f); 388 return (0); 389 390 parse_error: 391 fclose(f); 392 syslog(LOG_ERR, "parse error, line %d of %s", i, PATH_CONFFILE); 393 return (1); 394 } 395 396 397 /* 398 * splatter a file to stdout - max line length of 1024, 399 * used for spitting message files at users to tell them 400 * they've been bad or we're unavailable. 401 */ 402 static void 403 print_message(char *filename) 404 { 405 char buf[1024]; 406 FILE *f; 407 408 if ((f = fopen(filename, "r")) == NULL) 409 return; /* fail silently, we don't care if it isn't there */ 410 411 do { 412 if (fgets(buf, sizeof(buf), f) == NULL) { 413 fflush(stdout); 414 fclose(f); 415 return; 416 } 417 } while (fputs(buf, stdout) != EOF && !feof(f)); 418 fflush(stdout); 419 fclose(f); 420 } 421 422 /* 423 * allowed_luser checks to see if user "luser" is allowed to 424 * use this gateway by virtue of being listed in an allowed 425 * users file, namely /etc/authpf/authpf.allow . 426 * 427 * If /etc/authpf/authpf.allow does not exist, then we assume that 428 * all users who are allowed in by sshd(8) are permitted to 429 * use this gateway. If /etc/authpf/authpf.allow does exist, then a 430 * user must be listed if the connection is to continue, else 431 * the session terminates in the same manner as being banned. 432 */ 433 static int 434 allowed_luser(char *luser) 435 { 436 char *buf, *lbuf; 437 int matched; 438 size_t len; 439 FILE *f; 440 441 if ((f = fopen(PATH_ALLOWFILE, "r")) == NULL) { 442 if (errno == ENOENT) { 443 /* 444 * allowfile doesn't exist, thus this gateway 445 * isn't restricted to certain users... 446 */ 447 return (1); 448 } 449 450 /* 451 * luser may in fact be allowed, but we can't open 452 * the file even though it's there. probably a config 453 * problem. 454 */ 455 syslog(LOG_ERR, "cannot open allowed users file %s (%s)", 456 PATH_ALLOWFILE, strerror(errno)); 457 return (0); 458 } else { 459 /* 460 * /etc/authpf/authpf.allow exists, thus we do a linear 461 * search to see if they are allowed. 462 * also, if username "*" exists, then this is a 463 * "public" gateway, such as it is, so let 464 * everyone use it. 465 */ 466 lbuf = NULL; 467 while ((buf = fgetln(f, &len))) { 468 if (buf[len - 1] == '\n') 469 buf[len - 1] = '\0'; 470 else { 471 if ((lbuf = (char *)malloc(len + 1)) == NULL) 472 err(1, NULL); 473 memcpy(lbuf, buf, len); 474 lbuf[len] = '\0'; 475 buf = lbuf; 476 } 477 478 matched = strcmp(luser, buf) == 0 || strcmp("*", buf) == 0; 479 480 if (lbuf != NULL) { 481 free(lbuf); 482 lbuf = NULL; 483 } 484 485 if (matched) 486 return (1); /* matched an allowed username */ 487 } 488 syslog(LOG_INFO, "denied access to %s: not listed in %s", 489 luser, PATH_ALLOWFILE); 490 491 /* reuse buf */ 492 buf = "\n\nSorry, you are not allowed to use this facility!\n"; 493 fputs(buf, stdout); 494 } 495 fflush(stdout); 496 return (0); 497 } 498 499 /* 500 * check_luser checks to see if user "luser" has been banned 501 * from using us by virtue of having an file of the same name 502 * in the "luserdir" directory. 503 * 504 * If the user has been banned, we copy the contents of the file 505 * to the user's screen. (useful for telling the user what to 506 * do to get un-banned, or just to tell them they aren't 507 * going to be un-banned.) 508 */ 509 static int 510 check_luser(char *luserdir, char *luser) 511 { 512 FILE *f; 513 int n; 514 char tmp[MAXPATHLEN]; 515 516 n = snprintf(tmp, sizeof(tmp), "%s/%s", luserdir, luser); 517 if (n < 0 || (u_int)n >= sizeof(tmp)) { 518 syslog(LOG_ERR, "provided banned directory line too long (%s)", 519 luserdir); 520 return (0); 521 } 522 if ((f = fopen(tmp, "r")) == NULL) { 523 if (errno == ENOENT) { 524 /* 525 * file or dir doesn't exist, so therefore 526 * this luser isn't banned.. all is well 527 */ 528 return (1); 529 } else { 530 /* 531 * luser may in fact be banned, but we can't open the 532 * file even though it's there. probably a config 533 * problem. 534 */ 535 syslog(LOG_ERR, "cannot open banned file %s (%s)", 536 tmp, strerror(errno)); 537 return (0); 538 } 539 } else { 540 /* 541 * luser is banned - spit the file at them to 542 * tell what they can do and where they can go. 543 */ 544 syslog(LOG_INFO, "denied access to %s: %s exists", 545 luser, tmp); 546 547 /* reuse tmp */ 548 strlcpy(tmp, "\n\n-**- Sorry, you have been banned! -**-\n\n", 549 sizeof(tmp)); 550 while (fputs(tmp, stdout) != EOF && !feof(f)) { 551 if (fgets(tmp, sizeof(tmp), f) == NULL) { 552 fflush(stdout); 553 return (0); 554 } 555 } 556 } 557 fflush(stdout); 558 return (0); 559 } 560 561 /* 562 * Search for rulesets left by other authpf processes (either because they 563 * died ungracefully or were terminated) and remove them. 564 */ 565 static int 566 remove_stale_rulesets(void) 567 { 568 struct pfioc_ruleset prs; 569 u_int32_t nr, mnr; 570 571 memset(&prs, 0, sizeof(prs)); 572 strlcpy(prs.path, anchorname, sizeof(prs.path)); 573 if (ioctl(dev, DIOCGETRULESETS, &prs)) { 574 if (errno == EINVAL) 575 return (0); 576 else 577 return (1); 578 } 579 580 mnr = prs.nr; 581 nr = 0; 582 while (nr < mnr) { 583 char *s, *t; 584 pid_t pid; 585 586 prs.nr = nr; 587 if (ioctl(dev, DIOCGETRULESET, &prs)) 588 return (1); 589 errno = 0; 590 if ((t = strchr(prs.name, '(')) == NULL) 591 t = prs.name; 592 else 593 t++; 594 pid = strtoul(t, &s, 10); 595 if (!prs.name[0] || errno || 596 (*s && (t == prs.name || *s != ')'))) 597 return (1); 598 if (kill(pid, 0) && errno != EPERM) { 599 int i; 600 struct pfioc_trans_e t_e[PF_RULESET_MAX+1]; 601 struct pfioc_trans t; 602 603 bzero(&t, sizeof(t)); 604 bzero(t_e, sizeof(t_e)); 605 t.size = PF_RULESET_MAX+1; 606 t.esize = sizeof(t_e[0]); 607 t.array = t_e; 608 for (i = 0; i < PF_RULESET_MAX+1; ++i) { 609 t_e[i].rs_num = i; 610 snprintf(t_e[i].anchor, sizeof(t_e[i].anchor), 611 "%s/%s", anchorname, prs.name); 612 } 613 t_e[PF_RULESET_MAX].rs_num = PF_RULESET_TABLE; 614 if ((ioctl(dev, DIOCXBEGIN, &t) || 615 ioctl(dev, DIOCXCOMMIT, &t)) && 616 errno != EINVAL) 617 return (1); 618 mnr--; 619 } else 620 nr++; 621 } 622 return (0); 623 } 624 625 /* 626 * Add/remove filter entries for user "luser" from ip "ipsrc" 627 */ 628 static int 629 change_filter(int add, const char *luser, const char *ipsrc) 630 { 631 char *pargv[13] = { 632 "pfctl", "-p", "/dev/pf", "-q", "-a", "anchor/ruleset", 633 "-D", "user_ip=X", "-D", "user_id=X", "-f", 634 "file", NULL 635 }; 636 char *fdpath = NULL, *userstr = NULL, *ipstr = NULL; 637 char *rsn = NULL, *fn = NULL; 638 pid_t pid; 639 int s; 640 641 if (luser == NULL || !luser[0] || ipsrc == NULL || !ipsrc[0]) { 642 syslog(LOG_ERR, "invalid luser/ipsrc"); 643 goto error; 644 } 645 646 if (asprintf(&rsn, "%s/%s", anchorname, rulesetname) == -1) 647 goto no_mem; 648 if (asprintf(&fdpath, "/dev/fd/%d", dev) == -1) 649 goto no_mem; 650 if (asprintf(&ipstr, "user_ip=%s", ipsrc) == -1) 651 goto no_mem; 652 if (asprintf(&userstr, "user_id=%s", luser) == -1) 653 goto no_mem; 654 655 if (add) { 656 struct stat sb; 657 658 if (asprintf(&fn, "%s/%s/authpf.rules", PATH_USER_DIR, luser) 659 == -1) 660 goto no_mem; 661 if (stat(fn, &sb) == -1) { 662 free(fn); 663 if ((fn = strdup(PATH_PFRULES)) == NULL) 664 goto no_mem; 665 } 666 } 667 pargv[2] = fdpath; 668 pargv[5] = rsn; 669 pargv[7] = userstr; 670 pargv[9] = ipstr; 671 if (!add) 672 pargv[11] = "/dev/null"; 673 else 674 pargv[11] = fn; 675 676 switch (pid = fork()) { 677 case -1: 678 err(1, "fork failed"); 679 case 0: 680 execvp(PATH_PFCTL, pargv); 681 warn("exec of %s failed", PATH_PFCTL); 682 _exit(1); 683 } 684 685 /* parent */ 686 waitpid(pid, &s, 0); 687 if (s != 0) { 688 if (WIFEXITED(s)) { 689 syslog(LOG_ERR, "pfctl exited abnormally"); 690 goto error; 691 } 692 } 693 694 if (add) { 695 gettimeofday(&Tstart, NULL); 696 syslog(LOG_INFO, "allowing %s, user %s", ipsrc, luser); 697 } else { 698 gettimeofday(&Tend, NULL); 699 syslog(LOG_INFO, "removed %s, user %s - duration %ld seconds", 700 ipsrc, luser, Tend.tv_sec - Tstart.tv_sec); 701 } 702 return (0); 703 no_mem: 704 syslog(LOG_ERR, "malloc failed"); 705 error: 706 free(fdpath); 707 fdpath = NULL; 708 free(rsn); 709 rsn = NULL; 710 free(userstr); 711 userstr = NULL; 712 free(ipstr); 713 ipstr = NULL; 714 free(fn); 715 fn = NULL; 716 infile = NULL; 717 return (-1); 718 } 719 720 /* 721 * Add/remove this IP from the "authpf_users" table. 722 */ 723 static int 724 change_table(int add, const char *luser, const char *ipsrc) 725 { 726 struct pfioc_table io; 727 struct pfr_addr addr; 728 729 bzero(&io, sizeof(io)); 730 strlcpy(io.pfrio_table.pfrt_name, tablename, sizeof(io.pfrio_table)); 731 io.pfrio_buffer = &addr; 732 io.pfrio_esize = sizeof(addr); 733 io.pfrio_size = 1; 734 735 bzero(&addr, sizeof(addr)); 736 if (ipsrc == NULL || !ipsrc[0]) 737 return (-1); 738 if (inet_pton(AF_INET, ipsrc, &addr.pfra_ip4addr) == 1) { 739 addr.pfra_af = AF_INET; 740 addr.pfra_net = 32; 741 } else if (inet_pton(AF_INET6, ipsrc, &addr.pfra_ip6addr) == 1) { 742 addr.pfra_af = AF_INET6; 743 addr.pfra_net = 128; 744 } else { 745 syslog(LOG_ERR, "invalid ipsrc"); 746 return (-1); 747 } 748 749 if (ioctl(dev, add ? DIOCRADDADDRS : DIOCRDELADDRS, &io) && 750 errno != ESRCH) { 751 syslog(LOG_ERR, "cannot %s %s from table %s: %s", 752 add ? "add" : "remove", ipsrc, tablename, 753 strerror(errno)); 754 return (-1); 755 } 756 return (0); 757 } 758 759 /* 760 * This is to kill off states that would otherwise be left behind stateful 761 * rules. This means we don't need to allow in more traffic than we really 762 * want to, since we don't have to worry about any luser sessions lasting 763 * longer than their ssh session. This function is based on 764 * pfctl_kill_states from pfctl. 765 */ 766 static void 767 authpf_kill_states(void) 768 { 769 struct pfioc_state_kill psk; 770 struct pf_addr target; 771 772 memset(&psk, 0, sizeof(psk)); 773 memset(&target, 0, sizeof(target)); 774 775 if (inet_pton(AF_INET, ipsrc, &target.v4) == 1) 776 psk.psk_af = AF_INET; 777 else if (inet_pton(AF_INET6, ipsrc, &target.v6) == 1) 778 psk.psk_af = AF_INET6; 779 else { 780 syslog(LOG_ERR, "inet_pton(%s) failed", ipsrc); 781 return; 782 } 783 784 /* Kill all states from ipsrc */ 785 memcpy(&psk.psk_src.addr.v.a.addr, &target, 786 sizeof(psk.psk_src.addr.v.a.addr)); 787 memset(&psk.psk_src.addr.v.a.mask, 0xff, 788 sizeof(psk.psk_src.addr.v.a.mask)); 789 if (ioctl(dev, DIOCKILLSTATES, &psk)) 790 syslog(LOG_ERR, "DIOCKILLSTATES failed (%m)"); 791 792 /* Kill all states to ipsrc */ 793 memset(&psk.psk_src, 0, sizeof(psk.psk_src)); 794 memcpy(&psk.psk_dst.addr.v.a.addr, &target, 795 sizeof(psk.psk_dst.addr.v.a.addr)); 796 memset(&psk.psk_dst.addr.v.a.mask, 0xff, 797 sizeof(psk.psk_dst.addr.v.a.mask)); 798 if (ioctl(dev, DIOCKILLSTATES, &psk)) 799 syslog(LOG_ERR, "DIOCKILLSTATES failed (%m)"); 800 } 801 802 /* signal handler that makes us go away properly */ 803 static void 804 need_death(int signo) 805 { 806 want_death = 1; 807 } 808 809 /* 810 * function that removes our stuff when we go away. 811 */ 812 static __dead void 813 do_death(int active) 814 { 815 int ret = 0; 816 817 if (active) { 818 change_filter(0, luser, ipsrc); 819 change_table(0, luser, ipsrc); 820 authpf_kill_states(); 821 remove_stale_rulesets(); 822 } 823 if (pidfp) 824 ftruncate(fileno(pidfp), 0); 825 if (pidfile[0]) 826 if (unlink(pidfile) == -1) 827 syslog(LOG_ERR, "cannot unlink %s (%m)", pidfile); 828 exit(ret); 829 } 830