xref: /dragonfly/contrib/tcp_wrappers/tcpdchk.c (revision 1de703da) 
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   * $DragonFly: src/contrib/tcp_wrappers/tcpdchk.c,v 1.2 2003/06/17 04:24:06 dillon Exp $
18   */
19 
20 #ifndef lint
21 static char sccsid[] = "@(#) tcpdchk.c 1.8 97/02/12 02:13:25";
22 #endif
23 
24 /* System libraries. */
25 
26 #include <sys/types.h>
27 #include <sys/stat.h>
28 #ifdef INET6
29 #include <sys/socket.h>
30 #endif
31 #include <netinet/in.h>
32 #include <arpa/inet.h>
33 #include <stdio.h>
34 #include <syslog.h>
35 #include <setjmp.h>
36 #include <errno.h>
37 #include <netdb.h>
38 #include <string.h>
39 
40 extern int errno;
41 extern void exit();
42 extern int optind;
43 extern char *optarg;
44 
45 #ifndef INADDR_NONE
46 #define INADDR_NONE     (-1)		/* XXX should be 0xffffffff */
47 #endif
48 
49 #ifndef S_ISDIR
50 #define S_ISDIR(m)	(((m) & S_IFMT) == S_IFDIR)
51 #endif
52 
53 /* Application-specific. */
54 
55 #include "tcpd.h"
56 #include "inetcf.h"
57 #include "scaffold.h"
58 
59  /*
60   * Stolen from hosts_access.c...
61   */
62 static char sep[] = ", \t\n";
63 
64 #define	BUFLEN 2048
65 
66 int     resident = 0;
67 int     hosts_access_verbose = 0;
68 char   *hosts_allow_table = HOSTS_ALLOW;
69 char   *hosts_deny_table = HOSTS_DENY;
70 extern jmp_buf tcpd_buf;
71 
72  /*
73   * Local stuff.
74   */
75 static void usage();
76 static void parse_table();
77 static void print_list();
78 static void check_daemon_list();
79 static void check_client_list();
80 static void check_daemon();
81 static void check_user();
82 static int check_host();
83 static int reserved_name();
84 
85 #define PERMIT	1
86 #define DENY	0
87 
88 #define YES	1
89 #define	NO	0
90 
91 static int defl_verdict;
92 static char *myname;
93 static int allow_check;
94 static char *inetcf;
95 
96 int     main(argc, argv)
97 int     argc;
98 char  **argv;
99 {
100     struct request_info request;
101     struct stat st;
102     int     c;
103 
104     myname = argv[0];
105 
106     /*
107      * Parse the JCL.
108      */
109     while ((c = getopt(argc, argv, "adi:v")) != EOF) {
110 	switch (c) {
111 	case 'a':
112 	    allow_check = 1;
113 	    break;
114 	case 'd':
115 	    hosts_allow_table = "hosts.allow";
116 	    hosts_deny_table = "hosts.deny";
117 	    break;
118 	case 'i':
119 	    inetcf = optarg;
120 	    break;
121 	case 'v':
122 	    hosts_access_verbose++;
123 	    break;
124 	default:
125 	    usage();
126 	    /* NOTREACHED */
127 	}
128     }
129     if (argc != optind)
130 	usage();
131 
132     /*
133      * When confusion really strikes...
134      */
135     if (check_path(REAL_DAEMON_DIR, &st) < 0) {
136 	tcpd_warn("REAL_DAEMON_DIR %s: %m", REAL_DAEMON_DIR);
137     } else if (!S_ISDIR(st.st_mode)) {
138 	tcpd_warn("REAL_DAEMON_DIR %s is not a directory", REAL_DAEMON_DIR);
139     }
140 
141     /*
142      * Process the inet configuration file (or its moral equivalent). This
143      * information is used later to find references in hosts.allow/deny to
144      * unwrapped services, and other possible problems.
145      */
146     inetcf = inet_cfg(inetcf);
147     if (hosts_access_verbose)
148 	printf("Using network configuration file: %s\n", inetcf);
149 
150     /*
151      * These are not run from inetd but may have built-in access control.
152      */
153     inet_set("portmap", WR_NOT);
154     inet_set("rpcbind", WR_NOT);
155 
156     /*
157      * Check accessibility of access control files.
158      */
159     (void) check_path(hosts_allow_table, &st);
160     (void) check_path(hosts_deny_table, &st);
161 
162     /*
163      * Fake up an arbitrary service request.
164      */
165     request_init(&request,
166 		 RQ_DAEMON, "daemon_name",
167 		 RQ_SERVER_NAME, "server_hostname",
168 		 RQ_SERVER_ADDR, "server_addr",
169 		 RQ_USER, "user_name",
170 		 RQ_CLIENT_NAME, "client_hostname",
171 		 RQ_CLIENT_ADDR, "client_addr",
172 		 RQ_FILE, 1,
173 		 0);
174 
175     /*
176      * Examine all access-control rules.
177      */
178     defl_verdict = PERMIT;
179     parse_table(hosts_allow_table, &request);
180     defl_verdict = DENY;
181     parse_table(hosts_deny_table, &request);
182     return (0);
183 }
184 
185 /* usage - explain */
186 
187 static void usage()
188 {
189     fprintf(stderr, "usage: %s [-a] [-d] [-i inet_conf] [-v]\n", myname);
190     fprintf(stderr, "	-a: report rules with implicit \"ALLOW\" at end\n");
191     fprintf(stderr, "	-d: use allow/deny files in current directory\n");
192     fprintf(stderr, "	-i: location of inetd.conf file\n");
193     fprintf(stderr, "	-v: list all rules\n");
194     exit(1);
195 }
196 
197 /* parse_table - like table_match(), but examines _all_ entries */
198 
199 static void parse_table(table, request)
200 char   *table;
201 struct request_info *request;
202 {
203     FILE   *fp;
204     int     real_verdict;
205     char    sv_list[BUFLEN];		/* becomes list of daemons */
206     char   *cl_list;			/* becomes list of requests */
207     char   *sh_cmd;			/* becomes optional shell command */
208     char    buf[BUFSIZ];
209     int     verdict;
210     struct tcpd_context saved_context;
211 
212     saved_context = tcpd_context;		/* stupid compilers */
213 
214     if (fp = fopen(table, "r")) {
215 	tcpd_context.file = table;
216 	tcpd_context.line = 0;
217 	while (xgets(sv_list, sizeof(sv_list), fp)) {
218 	    if (sv_list[strlen(sv_list) - 1] != '\n') {
219 		tcpd_warn("missing newline or line too long");
220 		continue;
221 	    }
222 	    if (sv_list[0] == '#' || sv_list[strspn(sv_list, " \t\r\n")] == 0)
223 		continue;
224 	    if ((cl_list = split_at(sv_list, ':')) == 0) {
225 		tcpd_warn("missing \":\" separator");
226 		continue;
227 	    }
228 	    sh_cmd = split_at(cl_list, ':');
229 
230 	    if (hosts_access_verbose)
231 		printf("\n>>> Rule %s line %d:\n",
232 		       tcpd_context.file, tcpd_context.line);
233 
234 	    if (hosts_access_verbose)
235 		print_list("daemons:  ", sv_list);
236 	    check_daemon_list(sv_list);
237 
238 	    if (hosts_access_verbose)
239 		print_list("clients:  ", cl_list);
240 	    check_client_list(cl_list);
241 
242 #ifdef PROCESS_OPTIONS
243 	    real_verdict = defl_verdict;
244 	    if (sh_cmd) {
245 		verdict = setjmp(tcpd_buf);
246 		if (verdict != 0) {
247 		    real_verdict = (verdict == AC_PERMIT);
248 		} else {
249 		    dry_run = 1;
250 		    process_options(sh_cmd, request);
251 		    if (dry_run == 1 && real_verdict && allow_check)
252 			tcpd_warn("implicit \"allow\" at end of rule");
253 		}
254 	    } else if (defl_verdict && allow_check) {
255 		tcpd_warn("implicit \"allow\" at end of rule");
256 	    }
257 	    if (hosts_access_verbose)
258 		printf("access:   %s\n", real_verdict ? "granted" : "denied");
259 #else
260 	    if (sh_cmd)
261 		shell_cmd(percent_x(buf, sizeof(buf), sh_cmd, request));
262 	    if (hosts_access_verbose)
263 		printf("access:   %s\n", defl_verdict ? "granted" : "denied");
264 #endif
265 	}
266 	(void) fclose(fp);
267     } else if (errno != ENOENT) {
268 	tcpd_warn("cannot open %s: %m", table);
269     }
270     tcpd_context = saved_context;
271 }
272 
273 /* print_list - pretty-print a list */
274 
275 static void print_list(title, list)
276 char   *title;
277 char   *list;
278 {
279     char    buf[BUFLEN];
280     char   *cp;
281     char   *next;
282 
283     fputs(title, stdout);
284     strcpy(buf, list);
285 
286     for (cp = strtok(buf, sep); cp != 0; cp = next) {
287 	fputs(cp, stdout);
288 	next = strtok((char *) 0, sep);
289 	if (next != 0)
290 	    fputs(" ", stdout);
291     }
292     fputs("\n", stdout);
293 }
294 
295 /* check_daemon_list - criticize daemon list */
296 
297 static void check_daemon_list(list)
298 char   *list;
299 {
300     char    buf[BUFLEN];
301     char   *cp;
302     char   *host;
303     int     daemons = 0;
304 
305     strcpy(buf, list);
306 
307     for (cp = strtok(buf, sep); cp != 0; cp = strtok((char *) 0, sep)) {
308 	if (STR_EQ(cp, "EXCEPT")) {
309 	    daemons = 0;
310 	} else {
311 	    daemons++;
312 	    if ((host = split_at(cp + 1, '@')) != 0 && check_host(host) > 1) {
313 		tcpd_warn("host %s has more than one address", host);
314 		tcpd_warn("(consider using an address instead)");
315 	    }
316 	    check_daemon(cp);
317 	}
318     }
319     if (daemons == 0)
320 	tcpd_warn("daemon list is empty or ends in EXCEPT");
321 }
322 
323 /* check_client_list - criticize client list */
324 
325 static void check_client_list(list)
326 char   *list;
327 {
328     char    buf[BUFLEN];
329     char   *cp;
330     char   *host;
331     int     clients = 0;
332 
333     strcpy(buf, list);
334 
335     for (cp = strtok(buf, sep); cp != 0; cp = strtok((char *) 0, sep)) {
336 	if (STR_EQ(cp, "EXCEPT")) {
337 	    clients = 0;
338 	} else {
339 	    clients++;
340 	    if (host = split_at(cp + 1, '@')) {	/* user@host */
341 		check_user(cp);
342 		check_host(host);
343 	    } else {
344 		check_host(cp);
345 	    }
346 	}
347     }
348     if (clients == 0)
349 	tcpd_warn("client list is empty or ends in EXCEPT");
350 }
351 
352 /* check_daemon - criticize daemon pattern */
353 
354 static void check_daemon(pat)
355 char   *pat;
356 {
357     if (pat[0] == '@') {
358 	tcpd_warn("%s: daemon name begins with \"@\"", pat);
359     } else if (pat[0] == '/') {
360 	tcpd_warn("%s: daemon name begins with \"/\"", pat);
361     } else if (pat[0] == '.') {
362 	tcpd_warn("%s: daemon name begins with dot", pat);
363     } else if (pat[strlen(pat) - 1] == '.') {
364 	tcpd_warn("%s: daemon name ends in dot", pat);
365     } else if (STR_EQ(pat, "ALL") || STR_EQ(pat, unknown)) {
366 	 /* void */ ;
367     } else if (STR_EQ(pat, "FAIL")) {		/* obsolete */
368 	tcpd_warn("FAIL is no longer recognized");
369 	tcpd_warn("(use EXCEPT or DENY instead)");
370     } else if (reserved_name(pat)) {
371 	tcpd_warn("%s: daemon name may be reserved word", pat);
372     } else {
373 	switch (inet_get(pat)) {
374 	case WR_UNKNOWN:
375 	    tcpd_warn("%s: no such process name in %s", pat, inetcf);
376 	    inet_set(pat, WR_YES);		/* shut up next time */
377 	    break;
378 	case WR_NOT:
379 	    tcpd_warn("%s: service possibly not wrapped", pat);
380 	    inet_set(pat, WR_YES);
381 	    break;
382 	}
383     }
384 }
385 
386 /* check_user - criticize user pattern */
387 
388 static void check_user(pat)
389 char   *pat;
390 {
391     if (pat[0] == '@') {			/* @netgroup */
392 	tcpd_warn("%s: user name begins with \"@\"", pat);
393     } else if (pat[0] == '/') {
394 	tcpd_warn("%s: user name begins with \"/\"", pat);
395     } else if (pat[0] == '.') {
396 	tcpd_warn("%s: user name begins with dot", pat);
397     } else if (pat[strlen(pat) - 1] == '.') {
398 	tcpd_warn("%s: user name ends in dot", pat);
399     } else if (STR_EQ(pat, "ALL") || STR_EQ(pat, unknown)
400 	       || STR_EQ(pat, "KNOWN")) {
401 	 /* void */ ;
402     } else if (STR_EQ(pat, "FAIL")) {		/* obsolete */
403 	tcpd_warn("FAIL is no longer recognized");
404 	tcpd_warn("(use EXCEPT or DENY instead)");
405     } else if (reserved_name(pat)) {
406 	tcpd_warn("%s: user name may be reserved word", pat);
407     }
408 }
409 
410 #ifdef INET6
411 static int is_inet6_addr(pat)
412     char *pat;
413 {
414     struct addrinfo hints, *res;
415     int len, ret;
416     char ch;
417 
418     if (*pat != '[')
419 	return (0);
420     len = strlen(pat);
421     if ((ch = pat[len - 1]) != ']')
422 	return (0);
423     pat[len - 1] = '\0';
424     memset(&hints, 0, sizeof(hints));
425     hints.ai_family = AF_INET6;
426     hints.ai_socktype = SOCK_STREAM;
427     hints.ai_flags = AI_PASSIVE | AI_NUMERICHOST;
428     if ((ret = getaddrinfo(pat + 1, NULL, &hints, &res)) == 0)
429 	freeaddrinfo(res);
430     pat[len - 1] = ch;
431     return (ret == 0);
432 }
433 #endif
434 
435 /* check_host - criticize host pattern */
436 
437 static int check_host(pat)
438 char   *pat;
439 {
440     char    buf[BUFSIZ];
441     char   *mask;
442     int     addr_count = 1;
443     FILE   *fp;
444     struct tcpd_context saved_context;
445     char   *cp;
446     char   *wsp = " \t\r\n";
447 
448     if (pat[0] == '@') {			/* @netgroup */
449 #ifdef NO_NETGRENT
450 	/* SCO has no *netgrent() support */
451 #else
452 #ifdef NETGROUP
453 	char   *machinep;
454 	char   *userp;
455 	char   *domainp;
456 
457 	setnetgrent(pat + 1);
458 	if (getnetgrent(&machinep, &userp, &domainp) == 0)
459 	    tcpd_warn("%s: unknown or empty netgroup", pat + 1);
460 	endnetgrent();
461 #else
462 	tcpd_warn("netgroup support disabled");
463 #endif
464 #endif
465     } else if (pat[0] == '/') {			/* /path/name */
466 	if ((fp = fopen(pat, "r")) != 0) {
467 	    saved_context = tcpd_context;
468 	    tcpd_context.file = pat;
469 	    tcpd_context.line = 0;
470 	    while (fgets(buf, sizeof(buf), fp)) {
471 		tcpd_context.line++;
472 		for (cp = strtok(buf, wsp); cp; cp = strtok((char *) 0, wsp))
473 		    check_host(cp);
474 	    }
475 	    tcpd_context = saved_context;
476 	    fclose(fp);
477 	} else if (errno != ENOENT) {
478 	    tcpd_warn("open %s: %m", pat);
479 	}
480     } else if (mask = split_at(pat, '/')) {	/* network/netmask */
481 #ifdef INET6
482 	int mask_len;
483 
484 	if ((dot_quad_addr(pat) == INADDR_NONE
485 	    || dot_quad_addr(mask) == INADDR_NONE)
486 	    && (!is_inet6_addr(pat)
487 		|| ((mask_len = atoi(mask)) < 0 || mask_len > 128)))
488 #else
489 	if (dot_quad_addr(pat) == INADDR_NONE
490 	    || dot_quad_addr(mask) == INADDR_NONE)
491 #endif
492 	    tcpd_warn("%s/%s: bad net/mask pattern", pat, mask);
493     } else if (STR_EQ(pat, "FAIL")) {		/* obsolete */
494 	tcpd_warn("FAIL is no longer recognized");
495 	tcpd_warn("(use EXCEPT or DENY instead)");
496     } else if (reserved_name(pat)) {		/* other reserved */
497 	 /* void */ ;
498 #ifdef INET6
499     } else if (is_inet6_addr(pat)) { /* IPv6 address */
500 	addr_count = 1;
501 #endif
502     } else if (NOT_INADDR(pat)) {		/* internet name */
503 	if (pat[strlen(pat) - 1] == '.') {
504 	    tcpd_warn("%s: domain or host name ends in dot", pat);
505 	} else if (pat[0] != '.') {
506 	    addr_count = check_dns(pat);
507 	}
508     } else {					/* numeric form */
509 	if (STR_EQ(pat, "0.0.0.0") || STR_EQ(pat, "255.255.255.255")) {
510 	    /* void */ ;
511 	} else if (pat[0] == '.') {
512 	    tcpd_warn("%s: network number begins with dot", pat);
513 	} else if (pat[strlen(pat) - 1] != '.') {
514 	    check_dns(pat);
515 	}
516     }
517     return (addr_count);
518 }
519 
520 /* reserved_name - determine if name is reserved */
521 
522 static int reserved_name(pat)
523 char   *pat;
524 {
525     return (STR_EQ(pat, unknown)
526 	    || STR_EQ(pat, "KNOWN")
527 	    || STR_EQ(pat, paranoid)
528 	    || STR_EQ(pat, "ALL")
529 	    || STR_EQ(pat, "LOCAL"));
530 }
531