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 */
56 int main(int argc, char **argv)
59 struct addrinfo hints, *hp, *res;
63 char *myname = argv[0];
69 struct request_info request;
74 struct sockaddr_storage server_sin;
75 struct sockaddr_storage client_sin;
77 struct sockaddr_in server_sin;
78 struct sockaddr_in client_sin;
83 * Show what rule actually matched.
85 hosts_access_verbose = 2;
90 while ((ch = getopt(argc, argv, "di:")) != EOF) {
93 hosts_allow_table = "hosts.allow";
94 hosts_deny_table = "hosts.deny";
104 if (argc != optind + 2)
108 * When confusion really strikes...
110 if (check_path(REAL_DAEMON_DIR, &st) < 0) {
111 tcpd_warn("REAL_DAEMON_DIR %s: %m", REAL_DAEMON_DIR);
112 } else if (!S_ISDIR(st.st_mode)) {
113 tcpd_warn("REAL_DAEMON_DIR %s is not a directory", REAL_DAEMON_DIR);
117 * Default is to specify a daemon process name. When daemon@host is
118 * specified, separate the two parts.
120 if ((server = split_at(argv[optind], '@')) == 0)
122 if (argv[optind][0] == '/') {
123 daemon = strrchr(argv[optind], '/') + 1;
124 tcpd_warn("%s: daemon name normalized to: %s", argv[optind], daemon);
126 daemon = argv[optind];
130 * Default is to specify a client hostname or address. When user@host is
131 * specified, separate the two parts.
133 if ((client = split_at(argv[optind + 1], '@')) != 0) {
134 user = argv[optind + 1];
136 client = argv[optind + 1];
141 * Analyze the inetd (or tlid) configuration file, so that we can warn
142 * the user about services that may not be wrapped, services that are not
143 * configured, or services that are wrapped in an incorrect manner. Allow
144 * for services that are not run from inetd, or that have tcpd access
145 * control built into them.
147 inetcf = inet_cfg(inetcf);
148 inet_set("portmap", WR_NOT);
149 inet_set("rpcbind", WR_NOT);
150 switch (inet_get(daemon)) {
152 tcpd_warn("%s: no such process name in %s", daemon, inetcf);
155 tcpd_warn("%s: service possibly not wrapped", daemon);
160 * Check accessibility of access control files.
162 (void) check_path(hosts_allow_table, &st);
163 (void) check_path(hosts_deny_table, &st);
166 * Fill in what we have figured out sofar. Use socket and DNS routines
167 * for address and name conversions. We attach stdout to the request so
168 * that banner messages will become visible.
170 request_init(&request, RQ_DAEMON, daemon, RQ_USER, user, RQ_FILE, 1, 0);
171 sock_methods(&request);
174 * If a server hostname is specified, insist that the name maps to at
175 * most one address. eval_hostname() warns the user about name server
176 * problems, while using the request.server structure as a cache for host
177 * address and name conversion results.
179 if (NOT_INADDR(server) == 0 || HOSTNAME_KNOWN(server)) {
180 if ((hp = find_inet_addr(server)) == 0)
183 memset((char *) &server_sin, 0, sizeof(server_sin));
184 server_sin.sin_family = AF_INET;
186 request_set(&request, RQ_SERVER_SIN, &server_sin, 0);
189 for (res = hp, count = 0; res; res = res->ai_next, count++) {
190 memcpy(&server_sin, res->ai_addr, res->ai_addrlen);
192 for (count = 0; (addr = hp->h_addr_list[count]) != 0; count++) {
193 memcpy((char *) &server_sin.sin_addr, addr,
194 sizeof(server_sin.sin_addr));
198 * Force evaluation of server host name and address. Host name
199 * conflicts will be reported while eval_hostname() does its job.
201 request_set(&request, RQ_SERVER_NAME, "", RQ_SERVER_ADDR, "", 0);
202 if (STR_EQ(eval_hostname(request.server), unknown))
203 tcpd_warn("host address %s->name lookup failed",
204 eval_hostaddr(request.server));
207 fprintf(stderr, "Error: %s has more than one address\n", server);
208 fprintf(stderr, "Please specify an address instead\n");
217 request_set(&request, RQ_SERVER_NAME, server, 0);
221 * If a client address is specified, we simulate the effect of client
222 * hostname lookup failure.
224 if (dot_quad_addr(client) != INADDR_NONE) {
225 request_set(&request, RQ_CLIENT_ADDR, client, 0);
230 memset(&hints, 0, sizeof(hints));
231 hints.ai_family = AF_INET6;
232 hints.ai_socktype = SOCK_STREAM;
233 hints.ai_flags = AI_PASSIVE | AI_NUMERICHOST;
234 if (getaddrinfo(client, NULL, &hints, &res) == 0) {
236 request_set(&request, RQ_CLIENT_ADDR, client, 0);
243 * Perhaps they are testing special client hostname patterns that aren't
244 * really host names at all.
246 if (NOT_INADDR(client) && HOSTNAME_KNOWN(client) == 0) {
247 request_set(&request, RQ_CLIENT_NAME, client, 0);
253 * Otherwise, assume that a client hostname is specified, and insist that
254 * the address can be looked up. The reason for this requirement is that
255 * in real life the client address is available (at least with IP). Let
256 * eval_hostname() figure out if this host is properly registered, while
257 * using the request.client structure as a cache for host name and
258 * address conversion results.
260 if ((hp = find_inet_addr(client)) == 0)
263 request_set(&request, RQ_CLIENT_SIN, &client_sin, 0);
265 for (res = hp, count = 0; res; res = res->ai_next, count++) {
266 memcpy(&client_sin, res->ai_addr, res->ai_addrlen);
269 * getnameinfo() doesn't do reverse lookup against link-local
270 * address. So, we pass through host name evaluation against
273 if (res->ai_family != AF_INET6 ||
274 !IN6_IS_ADDR_LINKLOCAL(&((struct sockaddr_in6 *)res->ai_addr)->sin6_addr)) {
276 * Force evaluation of client host name and address. Host name
277 * conflicts will be reported while eval_hostname() does its job.
279 request_set(&request, RQ_CLIENT_NAME, "", RQ_CLIENT_ADDR, "", 0);
280 if (STR_EQ(eval_hostname(request.client), unknown))
281 tcpd_warn("host address %s->name lookup failed",
282 eval_hostaddr(request.client));
290 memset((char *) &client_sin, 0, sizeof(client_sin));
291 client_sin.sin_family = AF_INET;
292 request_set(&request, RQ_CLIENT_SIN, &client_sin, 0);
294 for (count = 0; (addr = hp->h_addr_list[count]) != 0; count++) {
295 memcpy((char *) &client_sin.sin_addr, addr,
296 sizeof(client_sin.sin_addr));
299 * Force evaluation of client host name and address. Host name
300 * conflicts will be reported while eval_hostname() does its job.
302 request_set(&request, RQ_CLIENT_NAME, "", RQ_CLIENT_ADDR, "", 0);
303 if (STR_EQ(eval_hostname(request.client), unknown))
304 tcpd_warn("host address %s->name lookup failed",
305 eval_hostaddr(request.client));
307 if (hp->h_addr_list[count + 1])
315 /* Explain how to use this program */
317 static void usage(char *myname)
319 fprintf(stderr, "usage: %s [-d] [-i inet_conf] daemon[@host] [user@]host\n",
321 fprintf(stderr, " -d: use allow/deny files in current directory\n");
322 fprintf(stderr, " -i: location of inetd.conf file\n");
326 /* Print interesting expansions */
328 static void expand(char *text, char *pattern, struct request_info *request)
332 if (STR_NE(percent_x(buf, sizeof(buf), pattern, request), unknown))
333 printf("%s %s\n", text, buf);
336 /* Try out a (server,client) pair */
338 static void tcpdmatch(struct request_info *request)
343 * Show what we really know. Suppress uninteresting noise.
345 expand("client: hostname", "%n", request);
346 expand("client: address ", "%a", request);
347 expand("client: username", "%u", request);
348 expand("server: hostname", "%N", request);
349 expand("server: address ", "%A", request);
350 expand("server: process ", "%d", request);
353 * Reset stuff that might be changed by options handlers. In dry-run
354 * mode, extension language routines that would not return should inform
355 * us of their plan, by clearing the dry_run flag. This is a bit clumsy
356 * but we must be able to verify hosts with more than one network
359 rfc931_timeout = RFC931_TIMEOUT;
360 allow_severity = SEVERITY;
361 deny_severity = LOG_WARNING;
365 * When paranoid mode is enabled, access is rejected no matter what the
366 * access control rules say.
369 if (STR_EQ(eval_hostname(request->client), paranoid)) {
370 printf("access: denied (PARANOID mode)\n\n");
376 * Report the access control verdict.
378 verdict = hosts_access(request);
379 printf("access: %s\n",
380 dry_run == 0 ? "delegated" :
381 verdict ? "granted" : "denied");