1 /* $OpenBSD: authpf.c,v 1.104 2007/02/24 17:35:08 beck Exp $ */ 2 /* $DragonFly: src/usr.sbin/authpf/authpf.c,v 1.2 2004/12/18 22:48:02 swildner Exp $ */ 3 4 /* 5 * Copyright (C) 1998 - 2007 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/param.h> 30 #include <sys/types.h> 31 #include <sys/file.h> 32 #include <sys/ioctl.h> 33 #include <sys/socket.h> 34 #include <sys/stat.h> 35 #include <sys/time.h> 36 #include <sys/wait.h> 37 38 #include <net/if.h> 39 #include <net/pf/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 #define __dead __dead2 56 57 static int read_config(FILE *); 58 static void print_message(const char *); 59 static int allowed_luser(const char *); 60 static int check_luser(const char *, const 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 *); 64 static void authpf_kill_states(void); 65 66 int dev_fd; /* 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 luser[MAXLOGNAME]; /* username */ 73 char ipsrc[256]; /* ip as a string */ 74 char pidfile[MAXPATHLEN]; /* we save pid in this file. */ 75 76 struct timeval Tstart, Tend; /* start and end times of session */ 77 78 volatile sig_atomic_t want_death; 79 static void need_death(int signo); 80 static __dead void do_death(int); 81 82 /* 83 * User shell for authenticating gateways. Sole purpose is to allow 84 * a user to ssh to a gateway, and have the gateway modify packet 85 * filters to allow access, then remove access when the user finishes 86 * up. Meant to be used only from ssh(1) connections. 87 */ 88 int 89 main(int argc __unused, char **argv __unused) 90 { 91 int lockcnt = 0, n, pidfd; 92 FILE *config; 93 struct in6_addr ina; 94 struct passwd *pw; 95 char *cp; 96 gid_t gid; 97 uid_t uid; 98 char *shell; 99 login_cap_t *lc; 100 101 config = fopen(PATH_CONFFILE, "r"); 102 if (config == NULL) { 103 syslog(LOG_ERR, "can not open %s (%m)", PATH_CONFFILE); 104 exit(1); 105 } 106 107 if ((cp = getenv("SSH_TTY")) == NULL) { 108 syslog(LOG_ERR, "non-interactive session connection for authpf"); 109 exit(1); 110 } 111 112 if ((cp = getenv("SSH_CLIENT")) == NULL) { 113 syslog(LOG_ERR, "cannot determine connection source"); 114 exit(1); 115 } 116 117 if (strlcpy(ipsrc, cp, sizeof(ipsrc)) >= sizeof(ipsrc)) { 118 syslog(LOG_ERR, "SSH_CLIENT variable too long"); 119 exit(1); 120 } 121 cp = strchr(ipsrc, ' '); 122 if (!cp) { 123 syslog(LOG_ERR, "corrupt SSH_CLIENT variable %s", ipsrc); 124 exit(1); 125 } 126 *cp = '\0'; 127 if (inet_pton(AF_INET, ipsrc, &ina) != 1 && 128 inet_pton(AF_INET6, ipsrc, &ina) != 1) { 129 syslog(LOG_ERR, 130 "cannot determine IP from SSH_CLIENT %s", ipsrc); 131 exit(1); 132 } 133 /* open the pf device */ 134 dev_fd = open(PATH_DEVFILE, O_RDWR); 135 if (dev_fd == -1) { 136 syslog(LOG_ERR, "cannot open packet filter device (%m)"); 137 goto die; 138 } 139 140 uid = getuid(); 141 pw = getpwuid(uid); 142 if (pw == NULL) { 143 syslog(LOG_ERR, "cannot find user for uid %u", uid); 144 goto die; 145 } 146 147 if ((lc = login_getclass(pw->pw_class)) != NULL) 148 shell = login_getcapstr(lc, "shell", pw->pw_shell, 149 pw->pw_shell); 150 else 151 shell = pw->pw_shell; 152 153 login_close(lc); 154 155 if (strcmp(shell, PATH_AUTHPF_SHELL)) { 156 syslog(LOG_ERR, "wrong shell for user %s, uid %u", 157 pw->pw_name, pw->pw_uid); 158 if (shell != pw->pw_shell) 159 free(shell); 160 goto die; 161 } 162 163 if (shell != pw->pw_shell) 164 free(shell); 165 166 /* 167 * Paranoia, but this data _does_ come from outside authpf, and 168 * truncation would be bad. 169 */ 170 if (strlcpy(luser, pw->pw_name, sizeof(luser)) >= sizeof(luser)) { 171 syslog(LOG_ERR, "username too long: %s", pw->pw_name); 172 goto die; 173 } 174 175 if ((n = snprintf(rulesetname, sizeof(rulesetname), "%s(%ld)", 176 luser, (long)getpid())) < 0 || n >= (int)sizeof(rulesetname)) { 177 syslog(LOG_INFO, "%s(%ld) too large, ruleset name will be %ld", 178 luser, (long)getpid(), (long)getpid()); 179 if ((n = snprintf(rulesetname, sizeof(rulesetname), "%ld", 180 (long)getpid())) < 0 || n >= (int)sizeof(rulesetname)) { 181 syslog(LOG_ERR, "pid too large for ruleset name"); 182 goto die; 183 } 184 } 185 186 187 /* Make our entry in /var/authpf as /var/authpf/ipaddr */ 188 n = snprintf(pidfile, sizeof(pidfile), "%s/%s", PATH_PIDFILE, ipsrc); 189 if (n < 0 || (u_int)n >= sizeof(pidfile)) { 190 syslog(LOG_ERR, "path to pidfile too long"); 191 goto die; 192 } 193 194 /* 195 * If someone else is already using this ip, then this person 196 * wants to switch users - so kill the old process and exit 197 * as well. 198 * 199 * Note, we could print a message and tell them to log out, but the 200 * usual case of this is that someone has left themselves logged in, 201 * with the authenticated connection iconized and someone else walks 202 * up to use and automatically logs in before using. If this just 203 * gets rid of the old one silently, the new user never knows they 204 * could have used someone else's old authentication. If we 205 * tell them to log out before switching users it is an invitation 206 * for abuse. 207 */ 208 209 do { 210 int save_errno, otherpid = -1; 211 char otherluser[MAXLOGNAME]; 212 213 if ((pidfd = open(pidfile, O_RDWR|O_CREAT, 0644)) == -1 || 214 (pidfp = fdopen(pidfd, "r+")) == NULL) { 215 if (pidfd != -1) 216 close(pidfd); 217 syslog(LOG_ERR, "cannot open or create %s: %s", pidfile, 218 strerror(errno)); 219 goto die; 220 } 221 222 if (flock(fileno(pidfp), LOCK_EX|LOCK_NB) == 0) 223 break; 224 save_errno = errno; 225 226 /* Mark our pid, and username to our file. */ 227 228 rewind(pidfp); 229 /* 31 == MAXLOGNAME - 1 */ 230 if (fscanf(pidfp, "%d\n%31s\n", &otherpid, otherluser) != 2) 231 otherpid = -1; 232 syslog(LOG_DEBUG, "tried to lock %s, in use by pid %d: %s", 233 pidfile, otherpid, strerror(save_errno)); 234 235 if (otherpid > 0) { 236 syslog(LOG_INFO, 237 "killing prior auth (pid %d) of %s by user %s", 238 otherpid, ipsrc, otherluser); 239 if (kill((pid_t) otherpid, SIGTERM) == -1) { 240 syslog(LOG_INFO, 241 "could not kill process %d: (%m)", 242 otherpid); 243 } 244 } 245 246 /* 247 * we try to kill the previous process and acquire the lock 248 * for 10 seconds, trying once a second. if we can't after 249 * 10 attempts we log an error and give up 250 */ 251 if (++lockcnt > 10) { 252 syslog(LOG_ERR, "cannot kill previous authpf (pid %d)", 253 otherpid); 254 fclose(pidfp); 255 pidfp = NULL; 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 pidfp = NULL; 266 } while (1); 267 268 /* whack the group list */ 269 gid = getegid(); 270 if (setgroups(1, &gid) == -1) { 271 syslog(LOG_INFO, "setgroups: %s", strerror(errno)); 272 do_death(0); 273 } 274 275 /* revoke privs */ 276 uid = getuid(); 277 if (setresuid(uid, uid, uid) == -1) { 278 syslog(LOG_INFO, "setresuid: %s", strerror(errno)); 279 do_death(0); 280 } 281 openlog("authpf", LOG_PID | LOG_NDELAY, LOG_DAEMON); 282 283 if (!check_luser(PATH_BAN_DIR, luser) || !allowed_luser(luser)) { 284 syslog(LOG_INFO, "user %s prohibited", luser); 285 do_death(0); 286 } 287 288 if (read_config(config)) { 289 syslog(LOG_ERR, "invalid config file %s", PATH_CONFFILE); 290 do_death(0); 291 } 292 293 if (remove_stale_rulesets()) { 294 syslog(LOG_INFO, "error removing stale rulesets"); 295 do_death(0); 296 } 297 298 /* We appear to be making headway, so actually mark our pid */ 299 rewind(pidfp); 300 fprintf(pidfp, "%ld\n%s\n", (long)getpid(), luser); 301 fflush(pidfp); 302 ftruncate(fileno(pidfp), ftell(pidfp)); 303 304 if (change_filter(1, luser, ipsrc) == -1) { 305 printf("Unable to modify filters\r\n"); 306 do_death(0); 307 } 308 if (change_table(1, ipsrc) == -1) { 309 printf("Unable to modify table\r\n"); 310 change_filter(0, luser, ipsrc); 311 do_death(0); 312 } 313 314 signal(SIGTERM, need_death); 315 signal(SIGINT, need_death); 316 signal(SIGALRM, need_death); 317 signal(SIGPIPE, need_death); 318 signal(SIGHUP, need_death); 319 signal(SIGQUIT, need_death); 320 signal(SIGTSTP, need_death); 321 while (1) { 322 printf("\r\nHello %s. ", luser); 323 printf("You are authenticated from host \"%s\"\r\n", ipsrc); 324 setproctitle("%s@%s", luser, ipsrc); 325 print_message(PATH_MESSAGE); 326 while (1) { 327 sleep(10); 328 if (want_death) 329 do_death(1); 330 } 331 } 332 333 /* NOTREACHED */ 334 dogdeath: 335 printf("\r\n\r\nSorry, this service is currently unavailable due to "); 336 printf("technical difficulties\r\n\r\n"); 337 print_message(PATH_PROBLEM); 338 printf("\r\nYour authentication process (pid %ld) was unable to run\n", 339 (long)getpid()); 340 sleep(180); /* them lusers read reaaaaal slow */ 341 die: 342 do_death(0); 343 } 344 345 /* 346 * reads config file in PATH_CONFFILE to set optional behaviours up 347 */ 348 static int 349 read_config(FILE *f) 350 { 351 char buf[1024]; 352 int i = 0; 353 354 do { 355 char **ap; 356 char *pair[4], *cp, *tp; 357 int len; 358 359 if (fgets(buf, sizeof(buf), f) == NULL) { 360 fclose(f); 361 return (0); 362 } 363 i++; 364 len = strlen(buf); 365 if (buf[len - 1] != '\n' && !feof(f)) { 366 syslog(LOG_ERR, "line %d too long in %s", i, 367 PATH_CONFFILE); 368 return (1); 369 } 370 buf[len - 1] = '\0'; 371 372 for (cp = buf; *cp == ' ' || *cp == '\t'; cp++) 373 ; /* nothing */ 374 375 if (!*cp || *cp == '#' || *cp == '\n') 376 continue; 377 378 for (ap = pair; ap < &pair[3] && 379 (*ap = strsep(&cp, "=")) != NULL; ) { 380 if (**ap != '\0') 381 ap++; 382 } 383 if (ap != &pair[2]) 384 goto parse_error; 385 386 tp = pair[1] + strlen(pair[1]); 387 while ((*tp == ' ' || *tp == '\t') && tp >= pair[1]) 388 *tp-- = '\0'; 389 390 if (strcasecmp(pair[0], "anchor") == 0) { 391 if (!pair[1][0] || strlcpy(anchorname, pair[1], 392 sizeof(anchorname)) >= sizeof(anchorname)) 393 goto parse_error; 394 } 395 if (strcasecmp(pair[0], "table") == 0) { 396 if (!pair[1][0] || strlcpy(tablename, pair[1], 397 sizeof(tablename)) >= sizeof(tablename)) 398 goto parse_error; 399 } 400 } while (!feof(f) && !ferror(f)); 401 fclose(f); 402 return (0); 403 404 parse_error: 405 fclose(f); 406 syslog(LOG_ERR, "parse error, line %d of %s", i, PATH_CONFFILE); 407 return (1); 408 } 409 410 411 /* 412 * splatter a file to stdout - max line length of 1024, 413 * used for spitting message files at users to tell them 414 * they've been bad or we're unavailable. 415 */ 416 static void 417 print_message(const char *filename) 418 { 419 char buf[1024]; 420 FILE *f; 421 422 if ((f = fopen(filename, "r")) == NULL) 423 return; /* fail silently, we don't care if it isn't there */ 424 425 do { 426 if (fgets(buf, sizeof(buf), f) == NULL) { 427 fflush(stdout); 428 fclose(f); 429 return; 430 } 431 } while (fputs(buf, stdout) != EOF && !feof(f)); 432 fflush(stdout); 433 fclose(f); 434 } 435 436 /* 437 * allowed_luser checks to see if user "luser" is allowed to 438 * use this gateway by virtue of being listed in an allowed 439 * users file, namely /etc/authpf/authpf.allow . 440 * 441 * If /etc/authpf/authpf.allow does not exist, then we assume that 442 * all users who are allowed in by sshd(8) are permitted to 443 * use this gateway. If /etc/authpf/authpf.allow does exist, then a 444 * user must be listed if the connection is to continue, else 445 * the session terminates in the same manner as being banned. 446 */ 447 static int 448 allowed_luser(const char *user) 449 { 450 char *buf, *lbuf; 451 int matched; 452 size_t len; 453 FILE *f; 454 455 if ((f = fopen(PATH_ALLOWFILE, "r")) == NULL) { 456 if (errno == ENOENT) { 457 /* 458 * allowfile doesn't exist, thus this gateway 459 * isn't restricted to certain users... 460 */ 461 return (1); 462 } 463 464 /* 465 * user may in fact be allowed, but we can't open 466 * the file even though it's there. probably a config 467 * problem. 468 */ 469 syslog(LOG_ERR, "cannot open allowed users file %s (%s)", 470 PATH_ALLOWFILE, strerror(errno)); 471 return (0); 472 } else { 473 /* 474 * /etc/authpf/authpf.allow exists, thus we do a linear 475 * search to see if they are allowed. 476 * also, if username "*" exists, then this is a 477 * "public" gateway, such as it is, so let 478 * everyone use it. 479 */ 480 lbuf = NULL; 481 while ((buf = fgetln(f, &len))) { 482 if (buf[len - 1] == '\n') 483 buf[len - 1] = '\0'; 484 else { 485 if ((lbuf = (char *)malloc(len + 1)) == NULL) 486 err(1, NULL); 487 memcpy(lbuf, buf, len); 488 lbuf[len] = '\0'; 489 buf = lbuf; 490 } 491 492 matched = strcmp(user, buf) == 0 || strcmp("*", buf) == 0; 493 494 if (lbuf != NULL) { 495 free(lbuf); 496 lbuf = NULL; 497 } 498 499 if (matched) 500 return (1); /* matched an allowed username */ 501 } 502 syslog(LOG_INFO, "denied access to %s: not listed in %s", 503 user, PATH_ALLOWFILE); 504 505 fputs("\n\nSorry, you are not allowed to use this facility!\n", 506 stdout); 507 } 508 fflush(stdout); 509 return (0); 510 } 511 512 /* 513 * check_luser checks to see if user "luser" has been banned 514 * from using us by virtue of having an file of the same name 515 * in the "luserdir" directory. 516 * 517 * If the user has been banned, we copy the contents of the file 518 * to the user's screen. (useful for telling the user what to 519 * do to get un-banned, or just to tell them they aren't 520 * going to be un-banned.) 521 */ 522 static int 523 check_luser(const char *userdir, const char *user) 524 { 525 FILE *f; 526 int n; 527 char tmp[MAXPATHLEN]; 528 529 n = snprintf(tmp, sizeof(tmp), "%s/%s", userdir, user); 530 if (n < 0 || (u_int)n >= sizeof(tmp)) { 531 syslog(LOG_ERR, "provided banned directory line too long (%s)", 532 userdir); 533 return (0); 534 } 535 if ((f = fopen(tmp, "r")) == NULL) { 536 if (errno == ENOENT) { 537 /* 538 * file or dir doesn't exist, so therefore 539 * this luser isn't banned.. all is well 540 */ 541 return (1); 542 } else { 543 /* 544 * user may in fact be banned, but we can't open the 545 * file even though it's there. probably a config 546 * problem. 547 */ 548 syslog(LOG_ERR, "cannot open banned file %s (%s)", 549 tmp, strerror(errno)); 550 return (0); 551 } 552 } else { 553 /* 554 * user is banned - spit the file at them to 555 * tell what they can do and where they can go. 556 */ 557 syslog(LOG_INFO, "denied access to %s: %s exists", 558 luser, tmp); 559 560 /* reuse tmp */ 561 strlcpy(tmp, "\n\n-**- Sorry, you have been banned! -**-\n\n", 562 sizeof(tmp)); 563 while (fputs(tmp, stdout) != EOF && !feof(f)) { 564 if (fgets(tmp, sizeof(tmp), f) == NULL) { 565 fflush(stdout); 566 fclose(f); 567 return (0); 568 } 569 } 570 fclose(f); 571 } 572 fflush(stdout); 573 return (0); 574 } 575 576 /* 577 * Search for rulesets left by other authpf processes (either because they 578 * died ungracefully or were terminated) and remove them. 579 */ 580 static int 581 remove_stale_rulesets(void) 582 { 583 struct pfioc_ruleset prs; 584 u_int32_t nr, mnr; 585 586 memset(&prs, 0, sizeof(prs)); 587 strlcpy(prs.path, anchorname, sizeof(prs.path)); 588 if (ioctl(dev_fd, DIOCGETRULESETS, &prs)) { 589 if (errno == EINVAL) 590 return (0); 591 else 592 return (1); 593 } 594 595 mnr = prs.nr; 596 nr = 0; 597 while (nr < mnr) { 598 char *s, *t; 599 pid_t pid; 600 601 prs.nr = nr; 602 if (ioctl(dev_fd, DIOCGETRULESET, &prs)) 603 return (1); 604 errno = 0; 605 if ((t = strchr(prs.name, '(')) == NULL) 606 t = prs.name; 607 else 608 t++; 609 pid = strtoul(t, &s, 10); 610 if (!prs.name[0] || errno || 611 (*s && (t == prs.name || *s != ')'))) 612 return (1); 613 if (kill(pid, 0) && errno != EPERM) { 614 int i; 615 struct pfioc_trans_e t_e[PF_RULESET_MAX+1]; 616 struct pfioc_trans t_local; 617 618 bzero(&t, sizeof(t_local)); 619 bzero(t_e, sizeof(t_e)); 620 t_local.size = PF_RULESET_MAX+1; 621 t_local.esize = sizeof(t_e[0]); 622 t_local.array = t_e; 623 for (i = 0; i < PF_RULESET_MAX+1; ++i) { 624 t_e[i].rs_num = i; 625 snprintf(t_e[i].anchor, sizeof(t_e[i].anchor), 626 "%s/%s", anchorname, prs.name); 627 } 628 mnr--; 629 } else 630 nr++; 631 } 632 return (0); 633 } 634 635 /* 636 * Add/remove filter entries for user "luser" from ip "ipsrc" 637 */ 638 static int 639 change_filter(int add, const char *user, const char *his_ipsrc) 640 { 641 const char *pargv[13] = { 642 "pfctl", "-p", "/dev/pf", "-q", "-a", "anchor/ruleset", 643 "-D", "user_ip=X", "-D", "user_id=X", "-f", 644 "file", NULL 645 }; 646 char *fdpath = NULL, *userstr = NULL, *ipstr = NULL; 647 char *rsn = NULL, *fn = NULL; 648 pid_t pid; 649 gid_t gid; 650 int s; 651 652 if (user == NULL || !user[0] || his_ipsrc == NULL || !his_ipsrc[0]) { 653 syslog(LOG_ERR, "invalid user/ipsrc"); 654 goto error; 655 } 656 657 if (asprintf(&rsn, "%s/%s", anchorname, rulesetname) == -1) 658 goto no_mem; 659 if (asprintf(&fdpath, "/dev/fd/%d", dev_fd) == -1) 660 goto no_mem; 661 if (asprintf(&ipstr, "user_ip=%s", his_ipsrc) == -1) 662 goto no_mem; 663 if (asprintf(&userstr, "user_id=%s", user) == -1) 664 goto no_mem; 665 666 if (add) { 667 struct stat sb; 668 669 if (asprintf(&fn, "%s/%s/authpf.rules", PATH_USER_DIR, user) 670 == -1) 671 goto no_mem; 672 if (stat(fn, &sb) == -1) { 673 free(fn); 674 if ((fn = strdup(PATH_PFRULES)) == NULL) 675 goto no_mem; 676 } 677 } 678 pargv[2] = fdpath; 679 pargv[5] = rsn; 680 pargv[7] = userstr; 681 pargv[9] = ipstr; 682 if (!add) 683 pargv[11] = "/dev/null"; 684 else 685 pargv[11] = fn; 686 687 switch (pid = fork()) { 688 case -1: 689 syslog(LOG_ERR, "fork failed"); 690 goto error; 691 case 0: 692 /* revoke group privs before exec */ 693 gid = getgid(); 694 if (setregid(gid, gid) == -1) { 695 err(1, "setregid"); 696 } 697 execvp(PATH_PFCTL, __DECONST(char *const *, pargv)); 698 warn("exec of %s failed", PATH_PFCTL); 699 _exit(1); 700 } 701 702 /* parent */ 703 waitpid(pid, &s, 0); 704 if (s != 0) { 705 syslog(LOG_ERR, "pfctl exited abnormally"); 706 goto error; 707 } 708 709 if (add) { 710 gettimeofday(&Tstart, NULL); 711 syslog(LOG_INFO, "allowing %s, user %s", his_ipsrc, user); 712 } else { 713 gettimeofday(&Tend, NULL); 714 syslog(LOG_INFO, "removed %s, user %s - duration %ld seconds", 715 his_ipsrc, user, Tend.tv_sec - Tstart.tv_sec); 716 } 717 return (0); 718 no_mem: 719 syslog(LOG_ERR, "malloc failed"); 720 error: 721 free(fdpath); 722 free(rsn); 723 free(userstr); 724 free(ipstr); 725 free(fn); 726 return (-1); 727 } 728 729 /* 730 * Add/remove this IP from the "authpf_users" table. 731 */ 732 static int 733 change_table(int add, const char *his_ipsrc) 734 { 735 struct pfioc_table io; 736 struct pfr_addr addr; 737 738 bzero(&io, sizeof(io)); 739 strlcpy(io.pfrio_table.pfrt_name, tablename, 740 sizeof(io.pfrio_table.pfrt_name)); 741 io.pfrio_buffer = &addr; 742 io.pfrio_esize = sizeof(addr); 743 io.pfrio_size = 1; 744 745 bzero(&addr, sizeof(addr)); 746 if (his_ipsrc == NULL || !his_ipsrc[0]) 747 return (-1); 748 if (inet_pton(AF_INET, his_ipsrc, &addr.pfra_ip4addr) == 1) { 749 addr.pfra_af = AF_INET; 750 addr.pfra_net = 32; 751 } else if (inet_pton(AF_INET6, his_ipsrc, &addr.pfra_ip6addr) == 1) { 752 addr.pfra_af = AF_INET6; 753 addr.pfra_net = 128; 754 } else { 755 syslog(LOG_ERR, "invalid his_ipsrc"); 756 return (-1); 757 } 758 759 if (ioctl(dev_fd, add ? DIOCRADDADDRS : DIOCRDELADDRS, &io) && 760 errno != ESRCH) { 761 syslog(LOG_ERR, "cannot %s %s from table %s: %s", 762 add ? "add" : "remove", his_ipsrc, tablename, 763 strerror(errno)); 764 return (-1); 765 } 766 return (0); 767 } 768 769 /* 770 * This is to kill off states that would otherwise be left behind stateful 771 * rules. This means we don't need to allow in more traffic than we really 772 * want to, since we don't have to worry about any luser sessions lasting 773 * longer than their ssh session. This function is based on 774 * pfctl_kill_states from pfctl. 775 */ 776 static void 777 authpf_kill_states(void) 778 { 779 struct pfioc_state_kill psk; 780 struct pf_addr target; 781 782 memset(&psk, 0, sizeof(psk)); 783 memset(&target, 0, sizeof(target)); 784 785 if (inet_pton(AF_INET, ipsrc, &target.v4) == 1) 786 psk.psk_af = AF_INET; 787 else if (inet_pton(AF_INET6, ipsrc, &target.v6) == 1) 788 psk.psk_af = AF_INET6; 789 else { 790 syslog(LOG_ERR, "inet_pton(%s) failed", ipsrc); 791 return; 792 } 793 794 /* Kill all states from ipsrc */ 795 memcpy(&psk.psk_src.addr.v.a.addr, &target, 796 sizeof(psk.psk_src.addr.v.a.addr)); 797 memset(&psk.psk_src.addr.v.a.mask, 0xff, 798 sizeof(psk.psk_src.addr.v.a.mask)); 799 if (ioctl(dev_fd, DIOCKILLSTATES, &psk)) 800 syslog(LOG_ERR, "DIOCKILLSTATES failed (%m)"); 801 802 /* Kill all states to ipsrc */ 803 memset(&psk.psk_src, 0, sizeof(psk.psk_src)); 804 memcpy(&psk.psk_dst.addr.v.a.addr, &target, 805 sizeof(psk.psk_dst.addr.v.a.addr)); 806 memset(&psk.psk_dst.addr.v.a.mask, 0xff, 807 sizeof(psk.psk_dst.addr.v.a.mask)); 808 if (ioctl(dev_fd, DIOCKILLSTATES, &psk)) 809 syslog(LOG_ERR, "DIOCKILLSTATES failed (%m)"); 810 } 811 812 /* signal handler that makes us go away properly */ 813 static void 814 need_death(int signo __unused) 815 { 816 want_death = 1; 817 } 818 819 /* 820 * function that removes our stuff when we go away. 821 */ 822 static __dead void 823 do_death(int active) 824 { 825 int ret = 0; 826 827 if (active) { 828 change_filter(0, luser, ipsrc); 829 change_table(0, ipsrc); 830 authpf_kill_states(); 831 remove_stale_rulesets(); 832 } 833 if (pidfile[0] && (pidfp != NULL)) 834 if (unlink(pidfile) == -1) 835 syslog(LOG_ERR, "cannot unlink %s (%m)", pidfile); 836 exit(ret); 837 } 838