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: src/contrib/tcp_wrappers/tcpdchk.c,v 1.3.2.1 2000/07/18 08:34:55 ume Exp $
17 */
18
19 /* System libraries. */
20
21 #include <sys/types.h>
22 #include <sys/stat.h>
23 #ifdef INET6
24 #include <sys/socket.h>
25 #endif
26 #include <netinet/in.h>
27 #include <arpa/inet.h>
28 #include <stdio.h>
29 #include <syslog.h>
30 #include <setjmp.h>
31 #include <errno.h>
32 #include <netdb.h>
33 #include <string.h>
34 #include <stdlib.h>
35 #include <unistd.h>
36
37 extern void exit();
38 extern int optind;
39 extern char *optarg;
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();
72 static void parse_table();
73 static void print_list();
74 static void check_daemon_list();
75 static void check_client_list();
76 static void check_daemon();
77 static void check_user();
78 static int check_host();
79 static int reserved_name();
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
main(argc,argv)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
usage()183 static void usage()
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
parse_table(table,request)195 static void parse_table(table, request)
196 char *table;
197 struct request_info *request;
198 {
199 FILE *fp;
200 char sv_list[BUFLEN]; /* becomes list of daemons */
201 char *cl_list; /* becomes list of requests */
202 char *sh_cmd; /* becomes optional shell command */
203 char buf[BUFSIZ];
204 #ifdef PROCESS_OPTIONS
205 int real_verdict, verdict;
206 #endif
207 struct tcpd_context saved_context;
208
209 saved_context = tcpd_context; /* stupid compilers */
210
211 if ((fp = fopen(table, "r")) != NULL) {
212 tcpd_context.file = table;
213 tcpd_context.line = 0;
214 while (xgets(sv_list, sizeof(sv_list), fp)) {
215 if (sv_list[strlen(sv_list) - 1] != '\n') {
216 tcpd_warn("missing newline or line too long");
217 continue;
218 }
219 if (sv_list[0] == '#' || sv_list[strspn(sv_list, " \t\r\n")] == 0)
220 continue;
221 if ((cl_list = split_at(sv_list, ':')) == 0) {
222 tcpd_warn("missing \":\" separator");
223 continue;
224 }
225 sh_cmd = split_at(cl_list, ':');
226
227 if (hosts_access_verbose)
228 printf("\n>>> Rule %s line %d:\n",
229 tcpd_context.file, tcpd_context.line);
230
231 if (hosts_access_verbose)
232 print_list("daemons: ", sv_list);
233 check_daemon_list(sv_list);
234
235 if (hosts_access_verbose)
236 print_list("clients: ", cl_list);
237 check_client_list(cl_list);
238
239 #ifdef PROCESS_OPTIONS
240 real_verdict = defl_verdict;
241 if (sh_cmd) {
242 verdict = setjmp(tcpd_buf);
243 if (verdict != 0) {
244 real_verdict = (verdict == AC_PERMIT);
245 } else {
246 dry_run = 1;
247 process_options(sh_cmd, request);
248 if (dry_run == 1 && real_verdict && allow_check)
249 tcpd_warn("implicit \"allow\" at end of rule");
250 }
251 } else if (defl_verdict && allow_check) {
252 tcpd_warn("implicit \"allow\" at end of rule");
253 }
254 if (hosts_access_verbose)
255 printf("access: %s\n", real_verdict ? "granted" : "denied");
256 #else
257 if (sh_cmd)
258 shell_cmd(percent_x(buf, sizeof(buf), sh_cmd, request));
259 if (hosts_access_verbose)
260 printf("access: %s\n", defl_verdict ? "granted" : "denied");
261 #endif
262 }
263 (void) fclose(fp);
264 } else if (errno != ENOENT) {
265 tcpd_warn("cannot open %s: %m", table);
266 }
267 tcpd_context = saved_context;
268 }
269
270 /* print_list - pretty-print a list */
271
print_list(title,list)272 static void print_list(title, list)
273 char *title;
274 char *list;
275 {
276 char buf[BUFLEN];
277 char *cp;
278 char *next;
279
280 fputs(title, stdout);
281 strcpy(buf, list);
282
283 for (cp = strtok(buf, sep); cp != 0; cp = next) {
284 fputs(cp, stdout);
285 next = strtok((char *) 0, sep);
286 if (next != 0)
287 fputs(" ", stdout);
288 }
289 fputs("\n", stdout);
290 }
291
292 /* check_daemon_list - criticize daemon list */
293
check_daemon_list(list)294 static void check_daemon_list(list)
295 char *list;
296 {
297 char buf[BUFLEN];
298 char *cp;
299 char *host;
300 int daemons = 0;
301
302 strcpy(buf, list);
303
304 for (cp = strtok(buf, sep); cp != 0; cp = strtok((char *) 0, sep)) {
305 if (STR_EQ(cp, "EXCEPT")) {
306 daemons = 0;
307 } else {
308 daemons++;
309 if ((host = split_at(cp + 1, '@')) != 0 && check_host(host) > 1) {
310 tcpd_warn("host %s has more than one address", host);
311 tcpd_warn("(consider using an address instead)");
312 }
313 check_daemon(cp);
314 }
315 }
316 if (daemons == 0)
317 tcpd_warn("daemon list is empty or ends in EXCEPT");
318 }
319
320 /* check_client_list - criticize client list */
321
check_client_list(list)322 static void check_client_list(list)
323 char *list;
324 {
325 char buf[BUFLEN];
326 char *cp;
327 char *host;
328 int clients = 0;
329
330 strcpy(buf, list);
331
332 for (cp = strtok(buf, sep); cp != 0; cp = strtok((char *) 0, sep)) {
333 if (STR_EQ(cp, "EXCEPT")) {
334 clients = 0;
335 } else {
336 clients++;
337 if ((host = split_at(cp + 1, '@')) != NULL) { /* user@host */
338 check_user(cp);
339 check_host(host);
340 } else {
341 check_host(cp);
342 }
343 }
344 }
345 if (clients == 0)
346 tcpd_warn("client list is empty or ends in EXCEPT");
347 }
348
349 /* check_daemon - criticize daemon pattern */
350
check_daemon(pat)351 static void check_daemon(pat)
352 char *pat;
353 {
354 if (pat[0] == '@') {
355 tcpd_warn("%s: daemon name begins with \"@\"", pat);
356 } else 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 dot", pat);
360 } else if (pat[strlen(pat) - 1] == '.') {
361 tcpd_warn("%s: daemon name ends in dot", pat);
362 } else if (STR_EQ(pat, "ALL") || STR_EQ(pat, unknown)) {
363 /* void */ ;
364 } else if (STR_EQ(pat, "FAIL")) { /* obsolete */
365 tcpd_warn("FAIL is no longer recognized");
366 tcpd_warn("(use EXCEPT or DENY instead)");
367 } else if (reserved_name(pat)) {
368 tcpd_warn("%s: daemon name may be reserved word", pat);
369 } else {
370 switch (inet_get(pat)) {
371 case WR_UNKNOWN:
372 tcpd_warn("%s: no such process name in %s", pat, inetcf);
373 inet_set(pat, WR_YES); /* shut up next time */
374 break;
375 case WR_NOT:
376 tcpd_warn("%s: service possibly not wrapped", pat);
377 inet_set(pat, WR_YES);
378 break;
379 }
380 }
381 }
382
383 /* check_user - criticize user pattern */
384
check_user(pat)385 static void check_user(pat)
386 char *pat;
387 {
388 if (pat[0] == '@') { /* @netgroup */
389 tcpd_warn("%s: user name begins with \"@\"", pat);
390 } else if (pat[0] == '/') {
391 tcpd_warn("%s: user name begins with \"/\"", pat);
392 } else if (pat[0] == '.') {
393 tcpd_warn("%s: user name begins with dot", pat);
394 } else if (pat[strlen(pat) - 1] == '.') {
395 tcpd_warn("%s: user name ends in dot", pat);
396 } else if (STR_EQ(pat, "ALL") || STR_EQ(pat, unknown)
397 || STR_EQ(pat, "KNOWN")) {
398 /* void */ ;
399 } else if (STR_EQ(pat, "FAIL")) { /* obsolete */
400 tcpd_warn("FAIL is no longer recognized");
401 tcpd_warn("(use EXCEPT or DENY instead)");
402 } else if (reserved_name(pat)) {
403 tcpd_warn("%s: user name may be reserved word", pat);
404 }
405 }
406
407 #ifdef INET6
is_inet6_addr(pat)408 static int is_inet6_addr(pat)
409 char *pat;
410 {
411 struct addrinfo hints, *res;
412 int len, ret;
413 char ch;
414
415 if (*pat != '[')
416 return (0);
417 len = strlen(pat);
418 if ((ch = pat[len - 1]) != ']')
419 return (0);
420 pat[len - 1] = '\0';
421 memset(&hints, 0, sizeof(hints));
422 hints.ai_family = AF_INET6;
423 hints.ai_socktype = SOCK_STREAM;
424 hints.ai_flags = AI_PASSIVE | AI_NUMERICHOST;
425 if ((ret = getaddrinfo(pat + 1, NULL, &hints, &res)) == 0)
426 freeaddrinfo(res);
427 pat[len - 1] = ch;
428 return (ret == 0);
429 }
430 #endif
431
432 /* check_host - criticize host pattern */
433
check_host(pat)434 static int check_host(pat)
435 char *pat;
436 {
437 char buf[BUFSIZ];
438 char *mask;
439 int addr_count = 1;
440 FILE *fp;
441 struct tcpd_context saved_context;
442 char *cp;
443 char *wsp = " \t\r\n";
444
445 if (pat[0] == '@') { /* @netgroup */
446 #ifdef NO_NETGRENT
447 /* SCO has no *netgrent() support */
448 #else
449 #ifdef NETGROUP
450 char *machinep;
451 char *userp;
452 char *domainp;
453
454 setnetgrent(pat + 1);
455 if (getnetgrent(&machinep, &userp, &domainp) == 0)
456 tcpd_warn("%s: unknown or empty netgroup", pat + 1);
457 endnetgrent();
458 #else
459 tcpd_warn("netgroup support disabled");
460 #endif
461 #endif
462 } else if (pat[0] == '/') { /* /path/name */
463 if ((fp = fopen(pat, "r")) != 0) {
464 saved_context = tcpd_context;
465 tcpd_context.file = pat;
466 tcpd_context.line = 0;
467 while (fgets(buf, sizeof(buf), fp)) {
468 tcpd_context.line++;
469 for (cp = strtok(buf, wsp); cp; cp = strtok((char *) 0, wsp))
470 check_host(cp);
471 }
472 tcpd_context = saved_context;
473 fclose(fp);
474 } else if (errno != ENOENT) {
475 tcpd_warn("open %s: %m", pat);
476 }
477 } else if ((mask = split_at(pat, '/')) != NULL) { /* network/netmask */
478 #ifdef INET6
479 int mask_len;
480
481 if ((dot_quad_addr(pat) == INADDR_NONE
482 || dot_quad_addr(mask) == INADDR_NONE)
483 && (!is_inet6_addr(pat)
484 || ((mask_len = atoi(mask)) < 0 || mask_len > 128)))
485 #else
486 if (dot_quad_addr(pat) == INADDR_NONE
487 || dot_quad_addr(mask) == INADDR_NONE)
488 #endif
489 tcpd_warn("%s/%s: bad net/mask pattern", pat, mask);
490 } else if (STR_EQ(pat, "FAIL")) { /* obsolete */
491 tcpd_warn("FAIL is no longer recognized");
492 tcpd_warn("(use EXCEPT or DENY instead)");
493 } else if (reserved_name(pat)) { /* other reserved */
494 /* void */ ;
495 #ifdef INET6
496 } else if (is_inet6_addr(pat)) { /* IPv6 address */
497 addr_count = 1;
498 #endif
499 } else if (NOT_INADDR(pat)) { /* internet name */
500 if (pat[strlen(pat) - 1] == '.') {
501 tcpd_warn("%s: domain or host name ends in dot", pat);
502 } else if (pat[0] != '.') {
503 addr_count = check_dns(pat);
504 }
505 } else { /* numeric form */
506 if (STR_EQ(pat, "0.0.0.0") || STR_EQ(pat, "255.255.255.255")) {
507 /* void */ ;
508 } else if (pat[0] == '.') {
509 tcpd_warn("%s: network number begins with dot", pat);
510 } else if (pat[strlen(pat) - 1] != '.') {
511 check_dns(pat);
512 }
513 }
514 return (addr_count);
515 }
516
517 /* reserved_name - determine if name is reserved */
518
reserved_name(pat)519 static int reserved_name(pat)
520 char *pat;
521 {
522 return (STR_EQ(pat, unknown)
523 || STR_EQ(pat, "KNOWN")
524 || STR_EQ(pat, paranoid)
525 || STR_EQ(pat, "ALL")
526 || STR_EQ(pat, "LOCAL"));
527 }
528