1 /* 2 * tcpdchk - examine all tcpd access control rules and inetd.conf entries 3 * 4 * Usage: tcpdchk [-a] [-d] [-i inet_conf] [-v] 5 * 6 * -a: complain about implicit "allow" at end of rule. 7 * 8 * -d: rules in current directory. 9 * 10 * -i: location of inetd.conf file. 11 * 12 * -v: show all rules. 13 * 14 * Author: Wietse Venema, Eindhoven University of Technology, The Netherlands. 15 * 16 * $FreeBSD$ 17 */ 18 19 #ifndef lint 20 static char sccsid[] = "@(#) tcpdchk.c 1.8 97/02/12 02:13:25"; 21 #endif 22 23 /* System libraries. */ 24 25 #include <sys/types.h> 26 #include <sys/stat.h> 27 #ifdef INET6 28 #include <sys/socket.h> 29 #endif 30 #include <netinet/in.h> 31 #include <arpa/inet.h> 32 #include <stdio.h> 33 #include <syslog.h> 34 #include <setjmp.h> 35 #include <errno.h> 36 #include <netdb.h> 37 #include <string.h> 38 39 extern int errno; 40 extern void exit(); 41 extern int optind; 42 extern char *optarg; 43 44 #ifndef INADDR_NONE 45 #define INADDR_NONE (-1) /* XXX should be 0xffffffff */ 46 #endif 47 48 #ifndef S_ISDIR 49 #define S_ISDIR(m) (((m) & S_IFMT) == S_IFDIR) 50 #endif 51 52 /* Application-specific. */ 53 54 #include "tcpd.h" 55 #include "inetcf.h" 56 #include "scaffold.h" 57 58 /* 59 * Stolen from hosts_access.c... 60 */ 61 static char sep[] = ", \t\n"; 62 63 #define BUFLEN 2048 64 65 int resident = 0; 66 int hosts_access_verbose = 0; 67 char *hosts_allow_table = HOSTS_ALLOW; 68 char *hosts_deny_table = HOSTS_DENY; 69 extern jmp_buf tcpd_buf; 70 71 /* 72 * Local stuff. 73 */ 74 static void usage(); 75 static void parse_table(); 76 static void print_list(); 77 static void check_daemon_list(); 78 static void check_client_list(); 79 static void check_daemon(); 80 static void check_user(); 81 static int check_host(); 82 static int reserved_name(); 83 84 #define PERMIT 1 85 #define DENY 0 86 87 #define YES 1 88 #define NO 0 89 90 static int defl_verdict; 91 static char *myname; 92 static int allow_check; 93 static char *inetcf; 94 95 int main(argc, argv) 96 int argc; 97 char **argv; 98 { 99 struct request_info request; 100 struct stat st; 101 int c; 102 103 myname = argv[0]; 104 105 /* 106 * Parse the JCL. 107 */ 108 while ((c = getopt(argc, argv, "adi:v")) != EOF) { 109 switch (c) { 110 case 'a': 111 allow_check = 1; 112 break; 113 case 'd': 114 hosts_allow_table = "hosts.allow"; 115 hosts_deny_table = "hosts.deny"; 116 break; 117 case 'i': 118 inetcf = optarg; 119 break; 120 case 'v': 121 hosts_access_verbose++; 122 break; 123 default: 124 usage(); 125 /* NOTREACHED */ 126 } 127 } 128 if (argc != optind) 129 usage(); 130 131 /* 132 * When confusion really strikes... 133 */ 134 if (check_path(REAL_DAEMON_DIR, &st) < 0) { 135 tcpd_warn("REAL_DAEMON_DIR %s: %m", REAL_DAEMON_DIR); 136 } else if (!S_ISDIR(st.st_mode)) { 137 tcpd_warn("REAL_DAEMON_DIR %s is not a directory", REAL_DAEMON_DIR); 138 } 139 140 /* 141 * Process the inet configuration file (or its moral equivalent). This 142 * information is used later to find references in hosts.allow/deny to 143 * unwrapped services, and other possible problems. 144 */ 145 inetcf = inet_cfg(inetcf); 146 if (hosts_access_verbose) 147 printf("Using network configuration file: %s\n", inetcf); 148 149 /* 150 * These are not run from inetd but may have built-in access control. 151 */ 152 inet_set("portmap", WR_NOT); 153 inet_set("rpcbind", WR_NOT); 154 155 /* 156 * Check accessibility of access control files. 157 */ 158 (void) check_path(hosts_allow_table, &st); 159 (void) check_path(hosts_deny_table, &st); 160 161 /* 162 * Fake up an arbitrary service request. 163 */ 164 request_init(&request, 165 RQ_DAEMON, "daemon_name", 166 RQ_SERVER_NAME, "server_hostname", 167 RQ_SERVER_ADDR, "server_addr", 168 RQ_USER, "user_name", 169 RQ_CLIENT_NAME, "client_hostname", 170 RQ_CLIENT_ADDR, "client_addr", 171 RQ_FILE, 1, 172 0); 173 174 /* 175 * Examine all access-control rules. 176 */ 177 defl_verdict = PERMIT; 178 parse_table(hosts_allow_table, &request); 179 defl_verdict = DENY; 180 parse_table(hosts_deny_table, &request); 181 return (0); 182 } 183 184 /* usage - explain */ 185 186 static void usage() 187 { 188 fprintf(stderr, "usage: %s [-a] [-d] [-i inet_conf] [-v]\n", myname); 189 fprintf(stderr, " -a: report rules with implicit \"ALLOW\" at end\n"); 190 fprintf(stderr, " -d: use allow/deny files in current directory\n"); 191 fprintf(stderr, " -i: location of inetd.conf file\n"); 192 fprintf(stderr, " -v: list all rules\n"); 193 exit(1); 194 } 195 196 /* parse_table - like table_match(), but examines _all_ entries */ 197 198 static void parse_table(table, request) 199 char *table; 200 struct request_info *request; 201 { 202 FILE *fp; 203 int real_verdict; 204 char sv_list[BUFLEN]; /* becomes list of daemons */ 205 char *cl_list; /* becomes list of requests */ 206 char *sh_cmd; /* becomes optional shell command */ 207 char buf[BUFSIZ]; 208 int verdict; 209 struct tcpd_context saved_context; 210 211 saved_context = tcpd_context; /* stupid compilers */ 212 213 if (fp = fopen(table, "r")) { 214 tcpd_context.file = table; 215 tcpd_context.line = 0; 216 while (xgets(sv_list, sizeof(sv_list), fp)) { 217 if (sv_list[strlen(sv_list) - 1] != '\n') { 218 tcpd_warn("missing newline or line too long"); 219 continue; 220 } 221 if (sv_list[0] == '#' || sv_list[strspn(sv_list, " \t\r\n")] == 0) 222 continue; 223 if ((cl_list = split_at(sv_list, ':')) == 0) { 224 tcpd_warn("missing \":\" separator"); 225 continue; 226 } 227 sh_cmd = split_at(cl_list, ':'); 228 229 if (hosts_access_verbose) 230 printf("\n>>> Rule %s line %d:\n", 231 tcpd_context.file, tcpd_context.line); 232 233 if (hosts_access_verbose) 234 print_list("daemons: ", sv_list); 235 check_daemon_list(sv_list); 236 237 if (hosts_access_verbose) 238 print_list("clients: ", cl_list); 239 check_client_list(cl_list); 240 241 #ifdef PROCESS_OPTIONS 242 real_verdict = defl_verdict; 243 if (sh_cmd) { 244 verdict = setjmp(tcpd_buf); 245 if (verdict != 0) { 246 real_verdict = (verdict == AC_PERMIT); 247 } else { 248 dry_run = 1; 249 process_options(sh_cmd, request); 250 if (dry_run == 1 && real_verdict && allow_check) 251 tcpd_warn("implicit \"allow\" at end of rule"); 252 } 253 } else if (defl_verdict && allow_check) { 254 tcpd_warn("implicit \"allow\" at end of rule"); 255 } 256 if (hosts_access_verbose) 257 printf("access: %s\n", real_verdict ? "granted" : "denied"); 258 #else 259 if (sh_cmd) 260 shell_cmd(percent_x(buf, sizeof(buf), sh_cmd, request)); 261 if (hosts_access_verbose) 262 printf("access: %s\n", defl_verdict ? "granted" : "denied"); 263 #endif 264 } 265 (void) fclose(fp); 266 } else if (errno != ENOENT) { 267 tcpd_warn("cannot open %s: %m", table); 268 } 269 tcpd_context = saved_context; 270 } 271 272 /* print_list - pretty-print a list */ 273 274 static void print_list(title, list) 275 char *title; 276 char *list; 277 { 278 char buf[BUFLEN]; 279 char *cp; 280 char *next; 281 282 fputs(title, stdout); 283 strcpy(buf, list); 284 285 for (cp = strtok(buf, sep); cp != 0; cp = next) { 286 fputs(cp, stdout); 287 next = strtok((char *) 0, sep); 288 if (next != 0) 289 fputs(" ", stdout); 290 } 291 fputs("\n", stdout); 292 } 293 294 /* check_daemon_list - criticize daemon list */ 295 296 static void check_daemon_list(list) 297 char *list; 298 { 299 char buf[BUFLEN]; 300 char *cp; 301 char *host; 302 int daemons = 0; 303 304 strcpy(buf, list); 305 306 for (cp = strtok(buf, sep); cp != 0; cp = strtok((char *) 0, sep)) { 307 if (STR_EQ(cp, "EXCEPT")) { 308 daemons = 0; 309 } else { 310 daemons++; 311 if ((host = split_at(cp + 1, '@')) != 0 && check_host(host) > 1) { 312 tcpd_warn("host %s has more than one address", host); 313 tcpd_warn("(consider using an address instead)"); 314 } 315 check_daemon(cp); 316 } 317 } 318 if (daemons == 0) 319 tcpd_warn("daemon list is empty or ends in EXCEPT"); 320 } 321 322 /* check_client_list - criticize client list */ 323 324 static void check_client_list(list) 325 char *list; 326 { 327 char buf[BUFLEN]; 328 char *cp; 329 char *host; 330 int clients = 0; 331 332 strcpy(buf, list); 333 334 for (cp = strtok(buf, sep); cp != 0; cp = strtok((char *) 0, sep)) { 335 if (STR_EQ(cp, "EXCEPT")) { 336 clients = 0; 337 } else { 338 clients++; 339 if (host = split_at(cp + 1, '@')) { /* user@host */ 340 check_user(cp); 341 check_host(host); 342 } else { 343 check_host(cp); 344 } 345 } 346 } 347 if (clients == 0) 348 tcpd_warn("client list is empty or ends in EXCEPT"); 349 } 350 351 /* check_daemon - criticize daemon pattern */ 352 353 static void check_daemon(pat) 354 char *pat; 355 { 356 if (pat[0] == '@') { 357 tcpd_warn("%s: daemon name begins with \"@\"", pat); 358 } else if (pat[0] == '/') { 359 tcpd_warn("%s: daemon name begins with \"/\"", pat); 360 } else if (pat[0] == '.') { 361 tcpd_warn("%s: daemon name begins with dot", pat); 362 } else if (pat[strlen(pat) - 1] == '.') { 363 tcpd_warn("%s: daemon name ends in dot", pat); 364 } else if (STR_EQ(pat, "ALL") || STR_EQ(pat, unknown)) { 365 /* void */ ; 366 } else if (STR_EQ(pat, "FAIL")) { /* obsolete */ 367 tcpd_warn("FAIL is no longer recognized"); 368 tcpd_warn("(use EXCEPT or DENY instead)"); 369 } else if (reserved_name(pat)) { 370 tcpd_warn("%s: daemon name may be reserved word", pat); 371 } else { 372 switch (inet_get(pat)) { 373 case WR_UNKNOWN: 374 tcpd_warn("%s: no such process name in %s", pat, inetcf); 375 inet_set(pat, WR_YES); /* shut up next time */ 376 break; 377 case WR_NOT: 378 tcpd_warn("%s: service possibly not wrapped", pat); 379 inet_set(pat, WR_YES); 380 break; 381 } 382 } 383 } 384 385 /* check_user - criticize user pattern */ 386 387 static void check_user(pat) 388 char *pat; 389 { 390 if (pat[0] == '@') { /* @netgroup */ 391 tcpd_warn("%s: user name begins with \"@\"", pat); 392 } else if (pat[0] == '/') { 393 tcpd_warn("%s: user name begins with \"/\"", pat); 394 } else if (pat[0] == '.') { 395 tcpd_warn("%s: user name begins with dot", pat); 396 } else if (pat[strlen(pat) - 1] == '.') { 397 tcpd_warn("%s: user name ends in dot", pat); 398 } else if (STR_EQ(pat, "ALL") || STR_EQ(pat, unknown) 399 || STR_EQ(pat, "KNOWN")) { 400 /* void */ ; 401 } else if (STR_EQ(pat, "FAIL")) { /* obsolete */ 402 tcpd_warn("FAIL is no longer recognized"); 403 tcpd_warn("(use EXCEPT or DENY instead)"); 404 } else if (reserved_name(pat)) { 405 tcpd_warn("%s: user name may be reserved word", pat); 406 } 407 } 408 409 #ifdef INET6 410 static int is_inet6_addr(pat) 411 char *pat; 412 { 413 struct addrinfo hints, *res; 414 int len, ret; 415 char ch; 416 417 if (*pat != '[') 418 return (0); 419 len = strlen(pat); 420 if ((ch = pat[len - 1]) != ']') 421 return (0); 422 pat[len - 1] = '\0'; 423 memset(&hints, 0, sizeof(hints)); 424 hints.ai_family = AF_INET6; 425 hints.ai_socktype = SOCK_STREAM; 426 hints.ai_flags = AI_PASSIVE | AI_NUMERICHOST; 427 if ((ret = getaddrinfo(pat + 1, NULL, &hints, &res)) == 0) 428 freeaddrinfo(res); 429 pat[len - 1] = ch; 430 return (ret == 0); 431 } 432 #endif 433 434 /* check_host - criticize host pattern */ 435 436 static int check_host(pat) 437 char *pat; 438 { 439 char buf[BUFSIZ]; 440 char *mask; 441 int addr_count = 1; 442 FILE *fp; 443 struct tcpd_context saved_context; 444 char *cp; 445 char *wsp = " \t\r\n"; 446 447 if (pat[0] == '@') { /* @netgroup */ 448 #ifdef NO_NETGRENT 449 /* SCO has no *netgrent() support */ 450 #else 451 #ifdef NETGROUP 452 char *machinep; 453 char *userp; 454 char *domainp; 455 456 setnetgrent(pat + 1); 457 if (getnetgrent(&machinep, &userp, &domainp) == 0) 458 tcpd_warn("%s: unknown or empty netgroup", pat + 1); 459 endnetgrent(); 460 #else 461 tcpd_warn("netgroup support disabled"); 462 #endif 463 #endif 464 } else if (pat[0] == '/') { /* /path/name */ 465 if ((fp = fopen(pat, "r")) != 0) { 466 saved_context = tcpd_context; 467 tcpd_context.file = pat; 468 tcpd_context.line = 0; 469 while (fgets(buf, sizeof(buf), fp)) { 470 tcpd_context.line++; 471 for (cp = strtok(buf, wsp); cp; cp = strtok((char *) 0, wsp)) 472 check_host(cp); 473 } 474 tcpd_context = saved_context; 475 fclose(fp); 476 } else if (errno != ENOENT) { 477 tcpd_warn("open %s: %m", pat); 478 } 479 } else if (mask = split_at(pat, '/')) { /* network/netmask */ 480 #ifdef INET6 481 int mask_len; 482 483 if ((dot_quad_addr(pat) == INADDR_NONE 484 || dot_quad_addr(mask) == INADDR_NONE) 485 && (!is_inet6_addr(pat) 486 || ((mask_len = atoi(mask)) < 0 || mask_len > 128))) 487 #else 488 if (dot_quad_addr(pat) == INADDR_NONE 489 || dot_quad_addr(mask) == INADDR_NONE) 490 #endif 491 tcpd_warn("%s/%s: bad net/mask pattern", pat, mask); 492 } else if (STR_EQ(pat, "FAIL")) { /* obsolete */ 493 tcpd_warn("FAIL is no longer recognized"); 494 tcpd_warn("(use EXCEPT or DENY instead)"); 495 } else if (reserved_name(pat)) { /* other reserved */ 496 /* void */ ; 497 #ifdef INET6 498 } else if (is_inet6_addr(pat)) { /* IPv6 address */ 499 addr_count = 1; 500 #endif 501 } else if (NOT_INADDR(pat)) { /* internet name */ 502 if (pat[strlen(pat) - 1] == '.') { 503 tcpd_warn("%s: domain or host name ends in dot", pat); 504 } else if (pat[0] != '.') { 505 addr_count = check_dns(pat); 506 } 507 } else { /* numeric form */ 508 if (STR_EQ(pat, "0.0.0.0") || STR_EQ(pat, "255.255.255.255")) { 509 /* void */ ; 510 } else if (pat[0] == '.') { 511 tcpd_warn("%s: network number begins with dot", pat); 512 } else if (pat[strlen(pat) - 1] != '.') { 513 check_dns(pat); 514 } 515 } 516 return (addr_count); 517 } 518 519 /* reserved_name - determine if name is reserved */ 520 521 static int reserved_name(pat) 522 char *pat; 523 { 524 return (STR_EQ(pat, unknown) 525 || STR_EQ(pat, "KNOWN") 526 || STR_EQ(pat, paranoid) 527 || STR_EQ(pat, "ALL") 528 || STR_EQ(pat, "LOCAL")); 529 } 530