tcpdchk.c revision 1.1
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 17 #ifndef lint 18 static char sccsid[] = "@(#) tcpdchk.c 1.7 96/02/11 17:01:34"; 19 #endif 20 21 /* System libraries. */ 22 23 #include <sys/types.h> 24 #include <sys/stat.h> 25 #include <netinet/in.h> 26 #include <arpa/inet.h> 27 #include <stdio.h> 28 #include <syslog.h> 29 #include <setjmp.h> 30 #include <errno.h> 31 #include <netdb.h> 32 #include <string.h> 33 34 extern int errno; 35 extern void exit(); 36 extern int optind; 37 extern char *optarg; 38 39 #ifndef INADDR_NONE 40 #define INADDR_NONE (-1) /* XXX should be 0xffffffff */ 41 #endif 42 43 #ifndef S_ISDIR 44 #define S_ISDIR(m) (((m) & S_IFMT) == S_IFDIR) 45 #endif 46 47 /* Application-specific. */ 48 49 #include "tcpd.h" 50 #include "inetcf.h" 51 #include "scaffold.h" 52 53 /* 54 * Stolen from hosts_access.c... 55 */ 56 static char sep[] = ", \t\n"; 57 58 #define BUFLEN 2048 59 60 int resident = 0; 61 int hosts_access_verbose = 0; 62 char *hosts_allow_table = HOSTS_ALLOW; 63 char *hosts_deny_table = HOSTS_DENY; 64 extern jmp_buf tcpd_buf; 65 66 /* 67 * Local stuff. 68 */ 69 static void usage(); 70 static void parse_table(); 71 static void print_list(); 72 static void check_daemon_list(); 73 static void check_client_list(); 74 static void check_daemon(); 75 static void check_user(); 76 static int check_host(); 77 static int reserved_name(); 78 79 #define PERMIT 1 80 #define DENY 0 81 82 #define YES 1 83 #define NO 0 84 85 static int defl_verdict; 86 static char *myname; 87 static int allow_check; 88 static char *inetcf; 89 90 int main(argc, argv) 91 int argc; 92 char **argv; 93 { 94 struct request_info request; 95 struct stat st; 96 int c; 97 98 myname = argv[0]; 99 100 /* 101 * Parse the JCL. 102 */ 103 while ((c = getopt(argc, argv, "adi:v")) != EOF) { 104 switch (c) { 105 case 'a': 106 allow_check = 1; 107 break; 108 case 'd': 109 hosts_allow_table = "hosts.allow"; 110 hosts_deny_table = "hosts.deny"; 111 break; 112 case 'i': 113 inetcf = optarg; 114 break; 115 case 'v': 116 hosts_access_verbose++; 117 break; 118 default: 119 usage(); 120 /* NOTREACHED */ 121 } 122 } 123 if (argc != optind) 124 usage(); 125 126 /* 127 * When confusion really strikes... 128 */ 129 if (check_path(REAL_DAEMON_DIR, &st) < 0) { 130 tcpd_warn("REAL_DAEMON_DIR %s: %m", REAL_DAEMON_DIR); 131 } else if (!S_ISDIR(st.st_mode)) { 132 tcpd_warn("REAL_DAEMON_DIR %s is not a directory", REAL_DAEMON_DIR); 133 } 134 135 /* 136 * Process the inet configuration file (or its moral equivalent). This 137 * information is used later to find references in hosts.allow/deny to 138 * unwrapped services, and other possible problems. 139 */ 140 inetcf = inet_cfg(inetcf); 141 if (hosts_access_verbose) 142 printf("Using network configuration file: %s\n", inetcf); 143 144 /* 145 * These are not run from inetd but may have built-in access control. 146 */ 147 inet_set("portmap", WR_NOT); 148 inet_set("rpcbind", WR_NOT); 149 150 /* 151 * Check accessibility of access control files. 152 */ 153 (void) check_path(hosts_allow_table, &st); 154 (void) check_path(hosts_deny_table, &st); 155 156 /* 157 * Fake up an arbitrary service request. 158 */ 159 request_init(&request, 160 RQ_DAEMON, "daemon_name", 161 RQ_SERVER_NAME, "server_hostname", 162 RQ_SERVER_ADDR, "server_addr", 163 RQ_USER, "user_name", 164 RQ_CLIENT_NAME, "client_hostname", 165 RQ_CLIENT_ADDR, "client_addr", 166 RQ_FILE, 1, 167 0); 168 169 /* 170 * Examine all access-control rules. 171 */ 172 defl_verdict = PERMIT; 173 parse_table(hosts_allow_table, &request); 174 defl_verdict = DENY; 175 parse_table(hosts_deny_table, &request); 176 return (0); 177 } 178 179 /* usage - explain */ 180 181 static void usage() 182 { 183 fprintf(stderr, "usage: %s [-a] [-d] [-i inet_conf] [-v]\n", myname); 184 fprintf(stderr, " -a: report rules with implicit \"ALLOW\" at end\n"); 185 fprintf(stderr, " -d: use allow/deny files in current directory\n"); 186 fprintf(stderr, " -i: location of inetd.conf file\n"); 187 fprintf(stderr, " -v: list all rules\n"); 188 exit(1); 189 } 190 191 /* parse_table - like table_match(), but examines _all_ entries */ 192 193 static void parse_table(table, request) 194 char *table; 195 struct request_info *request; 196 { 197 FILE *fp; 198 int real_verdict; 199 char sv_list[BUFLEN]; /* becomes list of daemons */ 200 char *cl_list; /* becomes list of requests */ 201 char *sh_cmd; /* becomes optional shell command */ 202 char buf[BUFSIZ]; 203 int verdict; 204 struct tcpd_context saved_context; 205 206 saved_context = tcpd_context; /* stupid compilers */ 207 208 if (fp = fopen(table, "r")) { 209 tcpd_context.file = table; 210 tcpd_context.line = 0; 211 while (xgets(sv_list, sizeof(sv_list), fp)) { 212 if (sv_list[strlen(sv_list) - 1] != '\n') { 213 tcpd_warn("missing newline or line too long"); 214 continue; 215 } 216 if (sv_list[0] == '#' || sv_list[strspn(sv_list, " \t\r\n")] == 0) 217 continue; 218 if ((cl_list = split_at(sv_list, ':')) == 0) { 219 tcpd_warn("missing \":\" separator"); 220 continue; 221 } 222 sh_cmd = split_at(cl_list, ':'); 223 224 if (hosts_access_verbose) 225 printf("\n>>> Rule %s line %d:\n", 226 tcpd_context.file, tcpd_context.line); 227 228 if (hosts_access_verbose) 229 print_list("daemons: ", sv_list); 230 check_daemon_list(sv_list); 231 232 if (hosts_access_verbose) 233 print_list("clients: ", cl_list); 234 check_client_list(cl_list); 235 236 #ifdef PROCESS_OPTIONS 237 real_verdict = defl_verdict; 238 if (sh_cmd) { 239 if ((verdict = setjmp(tcpd_buf)) != 0) { 240 real_verdict = (verdict == AC_PERMIT); 241 } else { 242 dry_run = 1; 243 process_options(sh_cmd, request); 244 if (dry_run == 1 && real_verdict && allow_check) 245 tcpd_warn("implicit \"allow\" at end of rule"); 246 } 247 } else if (defl_verdict && allow_check) { 248 tcpd_warn("implicit \"allow\" at end of rule"); 249 } 250 if (hosts_access_verbose) 251 printf("access: %s\n", real_verdict ? "granted" : "denied"); 252 #else 253 if (sh_cmd) 254 shell_cmd(percent_x(buf, sizeof(buf), sh_cmd, request)); 255 if (hosts_access_verbose) 256 printf("access: %s\n", defl_verdict ? "granted" : "denied"); 257 #endif 258 } 259 (void) fclose(fp); 260 } else if (errno != ENOENT) { 261 tcpd_warn("cannot open %s: %m", table); 262 } 263 tcpd_context = saved_context; 264 } 265 266 /* print_list - pretty-print a list */ 267 268 static void print_list(title, list) 269 char *title; 270 char *list; 271 { 272 char buf[BUFLEN]; 273 char *cp; 274 char *next; 275 276 fputs(title, stdout); 277 strcpy(buf, list); 278 279 for (cp = strtok(buf, sep); cp != 0; cp = next) { 280 fputs(cp, stdout); 281 next = strtok((char *) 0, sep); 282 if (next != 0) 283 fputs(" ", stdout); 284 } 285 fputs("\n", stdout); 286 } 287 288 /* check_daemon_list - criticize daemon list */ 289 290 static void check_daemon_list(list) 291 char *list; 292 { 293 char buf[BUFLEN]; 294 char *cp; 295 char *host; 296 int daemons = 0; 297 298 strcpy(buf, list); 299 300 for (cp = strtok(buf, sep); cp != 0; cp = strtok((char *) 0, sep)) { 301 if (STR_EQ(cp, "EXCEPT")) { 302 daemons = 0; 303 } else { 304 daemons++; 305 if ((host = split_at(cp + 1, '@')) != 0 && check_host(host) > 1) { 306 tcpd_warn("host %s has more than one address", host); 307 tcpd_warn("(consider using an address instead)"); 308 } 309 check_daemon(cp); 310 } 311 } 312 if (daemons == 0) 313 tcpd_warn("daemon list is empty or ends in EXCEPT"); 314 } 315 316 /* check_client_list - criticize client list */ 317 318 static void check_client_list(list) 319 char *list; 320 { 321 char buf[BUFLEN]; 322 char *cp; 323 char *host; 324 int clients = 0; 325 326 strcpy(buf, list); 327 328 for (cp = strtok(buf, sep); cp != 0; cp = strtok((char *) 0, sep)) { 329 if (STR_EQ(cp, "EXCEPT")) { 330 clients = 0; 331 } else { 332 clients++; 333 if (host = split_at(cp + 1, '@')) { /* user@host */ 334 check_user(cp); 335 check_host(host); 336 } else { 337 check_host(cp); 338 } 339 } 340 } 341 if (clients == 0) 342 tcpd_warn("client list is empty or ends in EXCEPT"); 343 } 344 345 /* check_daemon - criticize daemon pattern */ 346 347 static void check_daemon(pat) 348 char *pat; 349 { 350 if (pat[0] == '@') { 351 tcpd_warn("%s: daemon name begins with \"@\"", pat); 352 } else if (pat[0] == '.') { 353 tcpd_warn("%s: daemon name begins with dot", pat); 354 } else if (pat[strlen(pat) - 1] == '.') { 355 tcpd_warn("%s: daemon name ends in dot", pat); 356 } else if (STR_EQ(pat, "ALL") || STR_EQ(pat, unknown)) { 357 /* void */ ; 358 } else if (STR_EQ(pat, "FAIL")) { /* obsolete */ 359 tcpd_warn("FAIL is no longer recognized"); 360 tcpd_warn("(use EXCEPT or DENY instead)"); 361 } else if (reserved_name(pat)) { 362 tcpd_warn("%s: daemon name may be reserved word", pat); 363 } else { 364 switch (inet_get(pat)) { 365 case WR_UNKNOWN: 366 tcpd_warn("%s: no such process name in %s", pat, inetcf); 367 inet_set(pat, WR_YES); /* shut up next time */ 368 break; 369 case WR_NOT: 370 tcpd_warn("%s: service possibly not wrapped", pat); 371 inet_set(pat, WR_YES); 372 break; 373 } 374 } 375 } 376 377 /* check_user - criticize user pattern */ 378 379 static void check_user(pat) 380 char *pat; 381 { 382 if (pat[0] == '@') { /* @netgroup */ 383 tcpd_warn("%s: user name begins with \"@\"", pat); 384 } else if (pat[0] == '.') { 385 tcpd_warn("%s: user name begins with dot", pat); 386 } else if (pat[strlen(pat) - 1] == '.') { 387 tcpd_warn("%s: user name ends in dot", pat); 388 } else if (STR_EQ(pat, "ALL") || STR_EQ(pat, unknown) 389 || STR_EQ(pat, "KNOWN")) { 390 /* void */ ; 391 } else if (STR_EQ(pat, "FAIL")) { /* obsolete */ 392 tcpd_warn("FAIL is no longer recognized"); 393 tcpd_warn("(use EXCEPT or DENY instead)"); 394 } else if (reserved_name(pat)) { 395 tcpd_warn("%s: user name may be reserved word", pat); 396 } 397 } 398 399 /* check_host - criticize host pattern */ 400 401 static int check_host(pat) 402 char *pat; 403 { 404 char *mask; 405 int addr_count = 1; 406 407 if (pat[0] == '@') { /* @netgroup */ 408 #ifdef NO_NETGRENT 409 /* SCO has no *netgrent() support */ 410 #else 411 #ifdef NETGROUP 412 char *machinep; 413 char *userp; 414 char *domainp; 415 416 setnetgrent(pat + 1); 417 if (getnetgrent(&machinep, &userp, &domainp) == 0) 418 tcpd_warn("%s: unknown or empty netgroup", pat + 1); 419 endnetgrent(); 420 #else 421 tcpd_warn("netgroup support disabled"); 422 #endif 423 #endif 424 } else if (mask = split_at(pat, '/')) { /* network/netmask */ 425 if (dot_quad_addr(pat) == INADDR_NONE 426 || dot_quad_addr(mask) == INADDR_NONE) 427 tcpd_warn("%s/%s: bad net/mask pattern", pat, mask); 428 } else if (STR_EQ(pat, "FAIL")) { /* obsolete */ 429 tcpd_warn("FAIL is no longer recognized"); 430 tcpd_warn("(use EXCEPT or DENY instead)"); 431 } else if (reserved_name(pat)) { /* other reserved */ 432 /* void */ ; 433 } else if (NOT_INADDR(pat)) { /* internet name */ 434 if (pat[strlen(pat) - 1] == '.') { 435 tcpd_warn("%s: domain or host name ends in dot", pat); 436 } else if (pat[0] != '.') { 437 addr_count = check_dns(pat); 438 } 439 } else { /* numeric form */ 440 if (STR_EQ(pat, "0.0.0.0") || STR_EQ(pat, "255.255.255.255")) { 441 /* void */ ; 442 } else if (pat[0] == '.') { 443 tcpd_warn("%s: network number begins with dot", pat); 444 } else if (pat[strlen(pat) - 1] != '.') { 445 check_dns(pat); 446 } 447 } 448 return (addr_count); 449 } 450 451 /* reserved_name - determine if name is reserved */ 452 453 static int reserved_name(pat) 454 char *pat; 455 { 456 return (STR_EQ(pat, unknown) 457 || STR_EQ(pat, "KNOWN") 458 || STR_EQ(pat, paranoid) 459 || STR_EQ(pat, "ALL") 460 || STR_EQ(pat, "LOCAL")); 461 } 462
Indexes created Mon Sep 22 10:09:38 GMT 2025