1 /* $NetBSD: tcpdchk.c,v 1.5 1999/01/18 18:01:26 christos Exp $ */ 2 3 /* 4 * tcpdchk - examine all tcpd access control rules and inetd.conf entries 5 * 6 * Usage: tcpdchk [-a] [-d] [-i inet_conf] [-v] 7 * 8 * -a: complain about implicit "allow" at end of rule. 9 * 10 * -d: rules in current directory. 11 * 12 * -i: location of inetd.conf file. 13 * 14 * -v: show all rules. 15 * 16 * Author: Wietse Venema, Eindhoven University of Technology, The Netherlands. 17 */ 18 19 #include <sys/cdefs.h> 20 #ifndef lint 21 #if 0 22 static char sccsid[] = "@(#) tcpdchk.c 1.7 96/02/11 17:01:34"; 23 #else 24 __RCSID("$NetBSD: tcpdchk.c,v 1.5 1999/01/18 18:01:26 christos Exp $"); 25 #endif 26 #endif 27 28 /* System libraries. */ 29 30 #include <sys/types.h> 31 #include <sys/stat.h> 32 #include <netinet/in.h> 33 #include <arpa/inet.h> 34 #include <stdio.h> 35 #include <syslog.h> 36 #include <setjmp.h> 37 #include <errno.h> 38 #include <netdb.h> 39 #include <string.h> 40 #include <stdlib.h> 41 #include <unistd.h> 42 43 #ifndef INADDR_NONE 44 #define INADDR_NONE (-1) /* XXX should be 0xffffffff */ 45 #endif 46 47 #ifndef S_ISDIR 48 #define S_ISDIR(m) (((m) & S_IFMT) == S_IFDIR) 49 #endif 50 51 /* Application-specific. */ 52 53 #include "tcpd.h" 54 #include "inetcf.h" 55 #include "scaffold.h" 56 57 #ifdef NO_NETGRENT 58 /* SCO has no *netgrent() support */ 59 #else 60 # ifdef NETGROUP 61 # include <netgroup.h> 62 # endif 63 #endif 64 65 /* 66 * Stolen from hosts_access.c... 67 */ 68 static char sep[] = ", \t\n"; 69 70 #define BUFLEN 2048 71 72 int resident = 0; 73 int hosts_access_verbose = 0; 74 char *hosts_allow_table = HOSTS_ALLOW; 75 char *hosts_deny_table = HOSTS_DENY; 76 extern jmp_buf tcpd_buf; 77 78 /* 79 * Local stuff. 80 */ 81 static void usage __P((void)); 82 static void parse_table __P((char *, struct request_info *)); 83 static void print_list __P((char *, char *)); 84 static void check_daemon_list __P((char *)); 85 static void check_client_list __P((char *)); 86 static void check_daemon __P((char *)); 87 static void check_user __P((char *)); 88 static int check_host __P((char *)); 89 static int reserved_name __P((char *)); 90 91 int main __P((int, char **)); 92 93 #define PERMIT 1 94 #define DENY 0 95 96 #define YES 1 97 #define NO 0 98 99 static int defl_verdict; 100 static char *myname; 101 static int allow_check; 102 static char *inetcf; 103 104 int main(argc, argv) 105 int argc; 106 char **argv; 107 { 108 struct request_info request; 109 struct stat st; 110 int c; 111 112 myname = argv[0]; 113 114 /* 115 * Parse the JCL. 116 */ 117 while ((c = getopt(argc, argv, "adi:v")) != -1) { 118 switch (c) { 119 case 'a': 120 allow_check = 1; 121 break; 122 case 'd': 123 hosts_allow_table = "hosts.allow"; 124 hosts_deny_table = "hosts.deny"; 125 break; 126 case 'i': 127 inetcf = optarg; 128 break; 129 case 'v': 130 hosts_access_verbose++; 131 break; 132 default: 133 usage(); 134 /* NOTREACHED */ 135 } 136 } 137 if (argc != optind) 138 usage(); 139 140 /* 141 * When confusion really strikes... 142 */ 143 if (check_path(REAL_DAEMON_DIR, &st) < 0) { 144 tcpd_warn("REAL_DAEMON_DIR %s: %m", REAL_DAEMON_DIR); 145 } else if (!S_ISDIR(st.st_mode)) { 146 tcpd_warn("REAL_DAEMON_DIR %s is not a directory", REAL_DAEMON_DIR); 147 } 148 149 /* 150 * Process the inet configuration file (or its moral equivalent). This 151 * information is used later to find references in hosts.allow/deny to 152 * unwrapped services, and other possible problems. 153 */ 154 inetcf = inet_cfg(inetcf); 155 if (hosts_access_verbose) 156 printf("Using network configuration file: %s\n", inetcf); 157 158 /* 159 * These are not run from inetd but may have built-in access control. 160 */ 161 inet_set("portmap", WR_NOT); 162 inet_set("rpcbind", WR_NOT); 163 164 /* 165 * Check accessibility of access control files. 166 */ 167 (void) check_path(hosts_allow_table, &st); 168 (void) check_path(hosts_deny_table, &st); 169 170 /* 171 * Fake up an arbitrary service request. 172 */ 173 request_init(&request, 174 RQ_DAEMON, "daemon_name", 175 RQ_SERVER_NAME, "server_hostname", 176 RQ_SERVER_ADDR, "server_addr", 177 RQ_USER, "user_name", 178 RQ_CLIENT_NAME, "client_hostname", 179 RQ_CLIENT_ADDR, "client_addr", 180 RQ_FILE, 1, 181 0); 182 183 /* 184 * Examine all access-control rules. 185 */ 186 defl_verdict = PERMIT; 187 parse_table(hosts_allow_table, &request); 188 defl_verdict = DENY; 189 parse_table(hosts_deny_table, &request); 190 return (0); 191 } 192 193 /* usage - explain */ 194 195 static void usage() 196 { 197 fprintf(stderr, "usage: %s [-a] [-d] [-i inet_conf] [-v]\n", myname); 198 fprintf(stderr, " -a: report rules with implicit \"ALLOW\" at end\n"); 199 fprintf(stderr, " -d: use allow/deny files in current directory\n"); 200 fprintf(stderr, " -i: location of inetd.conf file\n"); 201 fprintf(stderr, " -v: list all rules\n"); 202 exit(1); 203 } 204 205 /* parse_table - like table_match(), but examines _all_ entries */ 206 207 static void parse_table(table, request) 208 char *table; 209 struct request_info *request; 210 { 211 FILE *fp; 212 int real_verdict; 213 char sv_list[BUFLEN]; /* becomes list of daemons */ 214 char *cl_list; /* becomes list of requests */ 215 char *sh_cmd; /* becomes optional shell command */ 216 int verdict; 217 struct tcpd_context saved_context; 218 #ifdef __GNUC__ 219 /* XXX hack to avoid gcc warnings */ 220 (void) &real_verdict; 221 (void) &saved_context; 222 #endif 223 224 saved_context = tcpd_context; /* stupid compilers */ 225 226 if ((fp = fopen(table, "r")) != NULL) { 227 tcpd_context.file = table; 228 tcpd_context.line = 0; 229 while (xgets(sv_list, sizeof(sv_list), fp)) { 230 if (sv_list[strlen(sv_list) - 1] != '\n') { 231 tcpd_warn("missing newline or line too long"); 232 continue; 233 } 234 if (sv_list[0] == '#' || sv_list[strspn(sv_list, " \t\r\n")] == 0) 235 continue; 236 if ((cl_list = split_at(sv_list, ':')) == 0) { 237 tcpd_warn("missing \":\" separator"); 238 continue; 239 } 240 sh_cmd = split_at(cl_list, ':'); 241 242 if (hosts_access_verbose) 243 printf("\n>>> Rule %s line %d:\n", 244 tcpd_context.file, tcpd_context.line); 245 246 if (hosts_access_verbose) 247 print_list("daemons: ", sv_list); 248 check_daemon_list(sv_list); 249 250 if (hosts_access_verbose) 251 print_list("clients: ", cl_list); 252 check_client_list(cl_list); 253 254 #ifdef PROCESS_OPTIONS 255 real_verdict = defl_verdict; 256 if (sh_cmd) { 257 if ((verdict = setjmp(tcpd_buf)) != 0) { 258 real_verdict = (verdict == AC_PERMIT); 259 } else { 260 dry_run = 1; 261 process_options(sh_cmd, request); 262 if (dry_run == 1 && real_verdict && allow_check) 263 tcpd_warn("implicit \"allow\" at end of rule"); 264 } 265 } else if (defl_verdict && allow_check) { 266 tcpd_warn("implicit \"allow\" at end of rule"); 267 } 268 if (hosts_access_verbose) 269 printf("access: %s\n", real_verdict ? "granted" : "denied"); 270 #else 271 if (sh_cmd) 272 shell_cmd(percent_x(buf, sizeof(buf), sh_cmd, request)); 273 if (hosts_access_verbose) 274 printf("access: %s\n", defl_verdict ? "granted" : "denied"); 275 #endif 276 } 277 (void) fclose(fp); 278 } else if (errno != ENOENT) { 279 tcpd_warn("cannot open %s: %m", table); 280 } 281 tcpd_context = saved_context; 282 } 283 284 /* print_list - pretty-print a list */ 285 286 static void print_list(title, list) 287 char *title; 288 char *list; 289 { 290 char buf[BUFLEN]; 291 char *cp; 292 char *next; 293 294 fputs(title, stdout); 295 strcpy(buf, list); 296 297 for (cp = strtok(buf, sep); cp != 0; cp = next) { 298 fputs(cp, stdout); 299 next = strtok((char *) 0, sep); 300 if (next != 0) 301 fputs(" ", stdout); 302 } 303 fputs("\n", stdout); 304 } 305 306 /* check_daemon_list - criticize daemon list */ 307 308 static void check_daemon_list(list) 309 char *list; 310 { 311 char buf[BUFLEN]; 312 char *cp; 313 char *host; 314 int daemons = 0; 315 316 strcpy(buf, list); 317 318 for (cp = strtok(buf, sep); cp != 0; cp = strtok((char *) 0, sep)) { 319 if (STR_EQ(cp, "EXCEPT")) { 320 daemons = 0; 321 } else { 322 daemons++; 323 if ((host = split_at(cp + 1, '@')) != 0 && check_host(host) > 1) { 324 tcpd_warn("host %s has more than one address", host); 325 tcpd_warn("(consider using an address instead)"); 326 } 327 check_daemon(cp); 328 } 329 } 330 if (daemons == 0) 331 tcpd_warn("daemon list is empty or ends in EXCEPT"); 332 } 333 334 /* check_client_list - criticize client list */ 335 336 static void check_client_list(list) 337 char *list; 338 { 339 char buf[BUFLEN]; 340 char *cp; 341 char *host; 342 int clients = 0; 343 344 strcpy(buf, list); 345 346 for (cp = strtok(buf, sep); cp != 0; cp = strtok((char *) 0, sep)) { 347 if (STR_EQ(cp, "EXCEPT")) { 348 clients = 0; 349 } else { 350 clients++; 351 if ((host = split_at(cp + 1, '@')) != NULL) { /* user@host */ 352 check_user(cp); 353 check_host(host); 354 } else { 355 check_host(cp); 356 } 357 } 358 } 359 if (clients == 0) 360 tcpd_warn("client list is empty or ends in EXCEPT"); 361 } 362 363 /* check_daemon - criticize daemon pattern */ 364 365 static void check_daemon(pat) 366 char *pat; 367 { 368 if (pat[0] == '@') { 369 tcpd_warn("%s: daemon name begins with \"@\"", pat); 370 } else if (pat[0] == '.') { 371 tcpd_warn("%s: daemon name begins with dot", pat); 372 } else if (pat[strlen(pat) - 1] == '.') { 373 tcpd_warn("%s: daemon name ends in dot", pat); 374 } else if (STR_EQ(pat, "ALL") || STR_EQ(pat, unknown)) { 375 /* void */ ; 376 } else if (STR_EQ(pat, "FAIL")) { /* obsolete */ 377 tcpd_warn("FAIL is no longer recognized"); 378 tcpd_warn("(use EXCEPT or DENY instead)"); 379 } else if (reserved_name(pat)) { 380 tcpd_warn("%s: daemon name may be reserved word", pat); 381 } else { 382 switch (inet_get(pat)) { 383 case WR_UNKNOWN: 384 tcpd_warn("%s: no such process name in %s", pat, inetcf); 385 inet_set(pat, WR_YES); /* shut up next time */ 386 break; 387 case WR_NOT: 388 tcpd_warn("%s: service possibly not wrapped", pat); 389 inet_set(pat, WR_YES); 390 break; 391 } 392 } 393 } 394 395 /* check_user - criticize user pattern */ 396 397 static void check_user(pat) 398 char *pat; 399 { 400 if (pat[0] == '@') { /* @netgroup */ 401 tcpd_warn("%s: user name begins with \"@\"", pat); 402 } else if (pat[0] == '.') { 403 tcpd_warn("%s: user name begins with dot", pat); 404 } else if (pat[strlen(pat) - 1] == '.') { 405 tcpd_warn("%s: user name ends in dot", pat); 406 } else if (STR_EQ(pat, "ALL") || STR_EQ(pat, unknown) 407 || STR_EQ(pat, "KNOWN")) { 408 /* void */ ; 409 } else if (STR_EQ(pat, "FAIL")) { /* obsolete */ 410 tcpd_warn("FAIL is no longer recognized"); 411 tcpd_warn("(use EXCEPT or DENY instead)"); 412 } else if (reserved_name(pat)) { 413 tcpd_warn("%s: user name may be reserved word", pat); 414 } 415 } 416 417 /* check_host - criticize host pattern */ 418 419 static int check_host(pat) 420 char *pat; 421 { 422 char *mask; 423 int addr_count = 1; 424 425 if (pat[0] == '@') { /* @netgroup */ 426 #ifdef NO_NETGRENT 427 /* SCO has no *netgrent() support */ 428 #else 429 #ifdef NETGROUP 430 const char *machinep; 431 const char *userp; 432 const char *domainp; 433 434 setnetgrent(pat + 1); 435 if (getnetgrent(&machinep, &userp, &domainp) == 0) 436 tcpd_warn("%s: unknown or empty netgroup", pat + 1); 437 endnetgrent(); 438 #else 439 tcpd_warn("netgroup support disabled"); 440 #endif 441 #endif 442 } else if ((mask = split_at(pat, '/')) != NULL) { /* network/netmask */ 443 if (dot_quad_addr(pat) == INADDR_NONE 444 || dot_quad_addr(mask) == INADDR_NONE) 445 tcpd_warn("%s/%s: bad net/mask pattern", pat, mask); 446 } else if (STR_EQ(pat, "FAIL")) { /* obsolete */ 447 tcpd_warn("FAIL is no longer recognized"); 448 tcpd_warn("(use EXCEPT or DENY instead)"); 449 } else if (reserved_name(pat)) { /* other reserved */ 450 /* void */ ; 451 } else if (NOT_INADDR(pat)) { /* internet name */ 452 if (pat[strlen(pat) - 1] == '.') { 453 tcpd_warn("%s: domain or host name ends in dot", pat); 454 } else if (pat[0] != '.') { 455 addr_count = check_dns(pat); 456 } 457 } else { /* numeric form */ 458 if (STR_EQ(pat, "0.0.0.0") || STR_EQ(pat, "255.255.255.255")) { 459 /* void */ ; 460 } else if (pat[0] == '.') { 461 tcpd_warn("%s: network number begins with dot", pat); 462 } else if (pat[strlen(pat) - 1] != '.') { 463 check_dns(pat); 464 } 465 } 466 return (addr_count); 467 } 468 469 /* reserved_name - determine if name is reserved */ 470 471 static int reserved_name(pat) 472 char *pat; 473 { 474 return (STR_EQ(pat, unknown) 475 || STR_EQ(pat, "KNOWN") 476 || STR_EQ(pat, paranoid) 477 || STR_EQ(pat, "ALL") 478 || STR_EQ(pat, "LOCAL")); 479 } 480