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