2 * tcpdmatch - explain what tcpd would do in a specific case
4 * usage: tcpdmatch [-d] [-i inet_conf] daemon[@host] [user@]host
6 * -d: use the access control tables in the current directory.
8 * -i: location of inetd.conf file.
10 * All errors are reported to the standard error stream, including the errors
11 * that would normally be reported via the syslog daemon.
13 * Author: Wietse Venema, Eindhoven University of Technology, The Netherlands.
19 static char sccsid[] = "@(#) tcpdmatch.c 1.5 96/02/11 17:01:36";
22 /* System libraries. */
24 #include <sys/types.h>
26 #include <sys/socket.h>
27 #include <netinet/in.h>
28 #include <arpa/inet.h>
38 #define INADDR_NONE (-1) /* XXX should be 0xffffffff */
42 #define S_ISDIR(m) (((m) & S_IFMT) == S_IFDIR)
45 /* Application-specific. */
51 static void usage(char *myname);
52 static void tcpdmatch(struct request_info *request);
54 /* The main program */
61 struct addrinfo hints, *hp, *res;
65 char *myname = argv[0];
71 struct request_info request;
76 struct sockaddr_storage server_sin;
77 struct sockaddr_storage client_sin;
79 struct sockaddr_in server_sin;
80 struct sockaddr_in client_sin;
85 * Show what rule actually matched.
87 hosts_access_verbose = 2;
92 while ((ch = getopt(argc, argv, "di:")) != EOF) {
95 hosts_allow_table = "hosts.allow";
96 hosts_deny_table = "hosts.deny";
106 if (argc != optind + 2)
110 * When confusion really strikes...
112 if (check_path(REAL_DAEMON_DIR, &st) < 0) {
113 tcpd_warn("REAL_DAEMON_DIR %s: %m", REAL_DAEMON_DIR);
114 } else if (!S_ISDIR(st.st_mode)) {
115 tcpd_warn("REAL_DAEMON_DIR %s is not a directory", REAL_DAEMON_DIR);
119 * Default is to specify a daemon process name. When daemon@host is
120 * specified, separate the two parts.
122 if ((server = split_at(argv[optind], '@')) == 0)
124 if (argv[optind][0] == '/') {
125 daemon = strrchr(argv[optind], '/') + 1;
126 tcpd_warn("%s: daemon name normalized to: %s", argv[optind], daemon);
128 daemon = argv[optind];
132 * Default is to specify a client hostname or address. When user@host is
133 * specified, separate the two parts.
135 if ((client = split_at(argv[optind + 1], '@')) != 0) {
136 user = argv[optind + 1];
138 client = argv[optind + 1];
143 * Analyze the inetd (or tlid) configuration file, so that we can warn
144 * the user about services that may not be wrapped, services that are not
145 * configured, or services that are wrapped in an incorrect manner. Allow
146 * for services that are not run from inetd, or that have tcpd access
147 * control built into them.
149 inetcf = inet_cfg(inetcf);
150 inet_set("portmap", WR_NOT);
151 inet_set("rpcbind", WR_NOT);
152 switch (inet_get(daemon)) {
154 tcpd_warn("%s: no such process name in %s", daemon, inetcf);
157 tcpd_warn("%s: service possibly not wrapped", daemon);
162 * Check accessibility of access control files.
164 (void) check_path(hosts_allow_table, &st);
165 (void) check_path(hosts_deny_table, &st);
168 * Fill in what we have figured out sofar. Use socket and DNS routines
169 * for address and name conversions. We attach stdout to the request so
170 * that banner messages will become visible.
172 request_init(&request, RQ_DAEMON, daemon, RQ_USER, user, RQ_FILE, 1, 0);
173 sock_methods(&request);
176 * If a server hostname is specified, insist that the name maps to at
177 * most one address. eval_hostname() warns the user about name server
178 * problems, while using the request.server structure as a cache for host
179 * address and name conversion results.
181 if (NOT_INADDR(server) == 0 || HOSTNAME_KNOWN(server)) {
182 if ((hp = find_inet_addr(server)) == 0)
185 memset((char *) &server_sin, 0, sizeof(server_sin));
186 server_sin.sin_family = AF_INET;
188 request_set(&request, RQ_SERVER_SIN, &server_sin, 0);
191 for (res = hp, count = 0; res; res = res->ai_next, count++) {
192 memcpy(&server_sin, res->ai_addr, res->ai_addrlen);
194 for (count = 0; (addr = hp->h_addr_list[count]) != 0; count++) {
195 memcpy((char *) &server_sin.sin_addr, addr,
196 sizeof(server_sin.sin_addr));
200 * Force evaluation of server host name and address. Host name
201 * conflicts will be reported while eval_hostname() does its job.
203 request_set(&request, RQ_SERVER_NAME, "", RQ_SERVER_ADDR, "", 0);
204 if (STR_EQ(eval_hostname(request.server), unknown))
205 tcpd_warn("host address %s->name lookup failed",
206 eval_hostaddr(request.server));
209 fprintf(stderr, "Error: %s has more than one address\n", server);
210 fprintf(stderr, "Please specify an address instead\n");
219 request_set(&request, RQ_SERVER_NAME, server, 0);
223 * If a client address is specified, we simulate the effect of client
224 * hostname lookup failure.
226 if (dot_quad_addr(client) != INADDR_NONE) {
227 request_set(&request, RQ_CLIENT_ADDR, client, 0);
232 memset(&hints, 0, sizeof(hints));
233 hints.ai_family = AF_INET6;
234 hints.ai_socktype = SOCK_STREAM;
235 hints.ai_flags = AI_PASSIVE | AI_NUMERICHOST;
236 if (getaddrinfo(client, NULL, &hints, &res) == 0) {
238 request_set(&request, RQ_CLIENT_ADDR, client, 0);
245 * Perhaps they are testing special client hostname patterns that aren't
246 * really host names at all.
248 if (NOT_INADDR(client) && HOSTNAME_KNOWN(client) == 0) {
249 request_set(&request, RQ_CLIENT_NAME, client, 0);
255 * Otherwise, assume that a client hostname is specified, and insist that
256 * the address can be looked up. The reason for this requirement is that
257 * in real life the client address is available (at least with IP). Let
258 * eval_hostname() figure out if this host is properly registered, while
259 * using the request.client structure as a cache for host name and
260 * address conversion results.
262 if ((hp = find_inet_addr(client)) == 0)
265 request_set(&request, RQ_CLIENT_SIN, &client_sin, 0);
267 for (res = hp, count = 0; res; res = res->ai_next, count++) {
268 memcpy(&client_sin, res->ai_addr, res->ai_addrlen);
271 * getnameinfo() doesn't do reverse lookup against link-local
272 * address. So, we pass through host name evaluation against
275 if (res->ai_family != AF_INET6 ||
276 !IN6_IS_ADDR_LINKLOCAL(&((struct sockaddr_in6 *)res->ai_addr)->sin6_addr)) {
278 * Force evaluation of client host name and address. Host name
279 * conflicts will be reported while eval_hostname() does its job.
281 request_set(&request, RQ_CLIENT_NAME, "", RQ_CLIENT_ADDR, "", 0);
282 if (STR_EQ(eval_hostname(request.client), unknown))
283 tcpd_warn("host address %s->name lookup failed",
284 eval_hostaddr(request.client));
292 memset((char *) &client_sin, 0, sizeof(client_sin));
293 client_sin.sin_family = AF_INET;
294 request_set(&request, RQ_CLIENT_SIN, &client_sin, 0);
296 for (count = 0; (addr = hp->h_addr_list[count]) != 0; count++) {
297 memcpy((char *) &client_sin.sin_addr, addr,
298 sizeof(client_sin.sin_addr));
301 * Force evaluation of client host name and address. Host name
302 * conflicts will be reported while eval_hostname() does its job.
304 request_set(&request, RQ_CLIENT_NAME, "", RQ_CLIENT_ADDR, "", 0);
305 if (STR_EQ(eval_hostname(request.client), unknown))
306 tcpd_warn("host address %s->name lookup failed",
307 eval_hostaddr(request.client));
309 if (hp->h_addr_list[count + 1])
317 /* Explain how to use this program */
319 static void usage(myname)
322 fprintf(stderr, "usage: %s [-d] [-i inet_conf] daemon[@host] [user@]host\n",
324 fprintf(stderr, " -d: use allow/deny files in current directory\n");
325 fprintf(stderr, " -i: location of inetd.conf file\n");
329 /* Print interesting expansions */
331 static void expand(text, pattern, request)
334 struct request_info *request;
338 if (STR_NE(percent_x(buf, sizeof(buf), pattern, request), unknown))
339 printf("%s %s\n", text, buf);
342 /* Try out a (server,client) pair */
344 static void tcpdmatch(request)
345 struct request_info *request;
350 * Show what we really know. Suppress uninteresting noise.
352 expand("client: hostname", "%n", request);
353 expand("client: address ", "%a", request);
354 expand("client: username", "%u", request);
355 expand("server: hostname", "%N", request);
356 expand("server: address ", "%A", request);
357 expand("server: process ", "%d", request);
360 * Reset stuff that might be changed by options handlers. In dry-run
361 * mode, extension language routines that would not return should inform
362 * us of their plan, by clearing the dry_run flag. This is a bit clumsy
363 * but we must be able to verify hosts with more than one network
366 rfc931_timeout = RFC931_TIMEOUT;
367 allow_severity = SEVERITY;
368 deny_severity = LOG_WARNING;
372 * When paranoid mode is enabled, access is rejected no matter what the
373 * access control rules say.
376 if (STR_EQ(eval_hostname(request->client), paranoid)) {
377 printf("access: denied (PARANOID mode)\n\n");
383 * Report the access control verdict.
385 verdict = hosts_access(request);
386 printf("access: %s\n",
387 dry_run == 0 ? "delegated" :
388 verdict ? "granted" : "denied");