1 /* $FreeBSD$ */
2 /*
3 * Routines to parse an inetd.conf or tlid.conf file. This would be a great
4 * job for a PERL script.
5 *
6 * Author: Wietse Venema, Eindhoven University of Technology, The Netherlands.
7 */
8
9 #ifndef lint
10 static char sccsid[] = "@(#) inetcf.c 1.7 97/02/12 02:13:23";
11 #endif
12
13 #include <sys/types.h>
14 #include <sys/stat.h>
15 #include <stdio.h>
16 #include <errno.h>
17 #include <string.h>
18
19 extern int errno;
20 extern void exit();
21 extern char *malloc();
22
23 #include "tcpd.h"
24 #include "inetcf.h"
25
26 /*
27 * Network configuration files may live in unusual places. Here are some
28 * guesses. Shorter names follow longer ones.
29 */
30 char *inet_files[] = {
31 "/private/etc/inetd.conf", /* NEXT */
32 "/etc/inet/inetd.conf", /* SYSV4 */
33 "/usr/etc/inetd.conf", /* IRIX?? */
34 "/etc/inetd.conf", /* BSD */
35 "/etc/net/tlid.conf", /* SYSV4?? */
36 "/etc/saf/tlid.conf", /* SYSV4?? */
37 "/etc/tlid.conf", /* SYSV4?? */
38 0,
39 };
40
41 static void inet_chk();
42 static char *base_name();
43
44 /*
45 * Structure with everything we know about a service.
46 */
47 struct inet_ent {
48 struct inet_ent *next;
49 int type;
50 char name[1];
51 };
52
53 static struct inet_ent *inet_list = 0;
54
55 static char whitespace[] = " \t\r\n";
56
57 /* inet_conf - read in and examine inetd.conf (or tlid.conf) entries */
58
inet_cfg(conf)59 char *inet_cfg(conf)
60 char *conf;
61 {
62 char buf[BUFSIZ];
63 FILE *fp;
64 char *service;
65 char *protocol;
66 char *user;
67 char *path;
68 char *arg0;
69 char *arg1;
70 struct tcpd_context saved_context;
71 char *percent_m();
72 int i;
73 struct stat st;
74
75 saved_context = tcpd_context;
76
77 /*
78 * The inetd.conf (or tlid.conf) information is so useful that we insist
79 * on its availability. When no file is given run a series of educated
80 * guesses.
81 */
82 if (conf != 0) {
83 if ((fp = fopen(conf, "r")) == 0) {
84 fprintf(stderr, percent_m(buf, "open %s: %m\n"), conf);
85 exit(1);
86 }
87 } else {
88 for (i = 0; inet_files[i] && (fp = fopen(inet_files[i], "r")) == 0; i++)
89 /* void */ ;
90 if (fp == 0) {
91 fprintf(stderr, "Cannot find your inetd.conf or tlid.conf file.\n");
92 fprintf(stderr, "Please specify its location.\n");
93 exit(1);
94 }
95 conf = inet_files[i];
96 check_path(conf, &st);
97 }
98
99 /*
100 * Process the file. After the 7.0 wrapper release it became clear that
101 * there are many more inetd.conf formats than the 8 systems that I had
102 * studied. EP/IX uses a two-line specification for rpc services; HP-UX
103 * permits long lines to be broken with backslash-newline.
104 */
105 tcpd_context.file = conf;
106 tcpd_context.line = 0;
107 while (xgets(buf, sizeof(buf), fp)) {
108 service = strtok(buf, whitespace); /* service */
109 if (service == 0 || *service == '#')
110 continue;
111 if (STR_NE(service, "stream") && STR_NE(service, "dgram"))
112 strtok((char *) 0, whitespace); /* endpoint */
113 protocol = strtok((char *) 0, whitespace);
114 (void) strtok((char *) 0, whitespace); /* wait */
115 if ((user = strtok((char *) 0, whitespace)) == 0)
116 continue;
117 if (user[0] == '/') { /* user */
118 path = user;
119 } else { /* path */
120 if ((path = strtok((char *) 0, whitespace)) == 0)
121 continue;
122 }
123 if (path[0] == '?') /* IRIX optional service */
124 path++;
125 if (STR_EQ(path, "internal"))
126 continue;
127 if (path[strspn(path, "-0123456789")] == 0) {
128
129 /*
130 * ConvexOS puts RPC version numbers before path names. Jukka
131 * Ukkonen <ukkonen@csc.fi>.
132 */
133 if ((path = strtok((char *) 0, whitespace)) == 0)
134 continue;
135 }
136 if ((arg0 = strtok((char *) 0, whitespace)) == 0) {
137 tcpd_warn("incomplete line");
138 continue;
139 }
140 if (arg0[strspn(arg0, "0123456789")] == 0) {
141
142 /*
143 * We're reading a tlid.conf file, the format is:
144 *
145 * ...stuff... path arg_count arguments mod_count modules
146 */
147 if ((arg0 = strtok((char *) 0, whitespace)) == 0) {
148 tcpd_warn("incomplete line");
149 continue;
150 }
151 }
152 if ((arg1 = strtok((char *) 0, whitespace)) == 0)
153 arg1 = "";
154
155 inet_chk(protocol, path, arg0, arg1);
156 }
157 fclose(fp);
158 tcpd_context = saved_context;
159 return (conf);
160 }
161
162 /* inet_chk - examine one inetd.conf (tlid.conf?) entry */
163
inet_chk(protocol,path,arg0,arg1)164 static void inet_chk(protocol, path, arg0, arg1)
165 char *protocol;
166 char *path;
167 char *arg0;
168 char *arg1;
169 {
170 char daemon[BUFSIZ];
171 struct stat st;
172 int wrap_status = WR_MAYBE;
173 char *base_name_path = base_name(path);
174 char *tcpd_proc_name = (arg0[0] == '/' ? base_name(arg0) : arg0);
175
176 /*
177 * Always warn when the executable does not exist or when it is not
178 * executable.
179 */
180 if (check_path(path, &st) < 0) {
181 tcpd_warn("%s: not found: %m", path);
182 } else if ((st.st_mode & 0100) == 0) {
183 tcpd_warn("%s: not executable", path);
184 }
185
186 /*
187 * Cheat on the miscd tests, nobody uses it anymore.
188 */
189 if (STR_EQ(base_name_path, "miscd")) {
190 inet_set(arg0, WR_YES);
191 return;
192 }
193
194 /*
195 * While we are here...
196 */
197 if (STR_EQ(tcpd_proc_name, "rexd") || STR_EQ(tcpd_proc_name, "rpc.rexd"))
198 tcpd_warn("%s may be an insecure service", tcpd_proc_name);
199
200 /*
201 * The tcpd program gets most of the attention.
202 */
203 if (STR_EQ(base_name_path, "tcpd")) {
204
205 if (STR_EQ(tcpd_proc_name, "tcpd"))
206 tcpd_warn("%s is recursively calling itself", tcpd_proc_name);
207
208 wrap_status = WR_YES;
209
210 /*
211 * Check: some sites install the wrapper set-uid.
212 */
213 if ((st.st_mode & 06000) != 0)
214 tcpd_warn("%s: file is set-uid or set-gid", path);
215
216 /*
217 * Check: some sites insert tcpd in inetd.conf, instead of replacing
218 * the daemon pathname.
219 */
220 if (arg0[0] == '/' && STR_EQ(tcpd_proc_name, base_name(arg1)))
221 tcpd_warn("%s inserted before %s", path, arg0);
222
223 /*
224 * Check: make sure files exist and are executable. On some systems
225 * the network daemons are set-uid so we cannot complain. Note that
226 * tcpd takes the basename only in case of absolute pathnames.
227 */
228 if (arg0[0] == '/') { /* absolute path */
229 if (check_path(arg0, &st) < 0) {
230 tcpd_warn("%s: not found: %m", arg0);
231 } else if ((st.st_mode & 0100) == 0) {
232 tcpd_warn("%s: not executable", arg0);
233 }
234 } else { /* look in REAL_DAEMON_DIR */
235 sprintf(daemon, "%s/%s", REAL_DAEMON_DIR, arg0);
236 if (check_path(daemon, &st) < 0) {
237 tcpd_warn("%s: not found in %s: %m",
238 arg0, REAL_DAEMON_DIR);
239 } else if ((st.st_mode & 0100) == 0) {
240 tcpd_warn("%s: not executable", daemon);
241 }
242 }
243
244 } else {
245
246 /*
247 * No tcpd program found. Perhaps they used the "simple installation"
248 * recipe. Look for a file with the same basename in REAL_DAEMON_DIR.
249 * Draw some conservative conclusions when a distinct file is found.
250 */
251 sprintf(daemon, "%s/%s", REAL_DAEMON_DIR, arg0);
252 if (STR_EQ(path, daemon)) {
253 #ifdef __FreeBSD__
254 wrap_status = WR_MAYBE;
255 #else
256 wrap_status = WR_NOT;
257 #endif
258 } else if (check_path(daemon, &st) >= 0) {
259 wrap_status = WR_MAYBE;
260 } else if (errno == ENOENT) {
261 wrap_status = WR_NOT;
262 } else {
263 tcpd_warn("%s: file lookup: %m", daemon);
264 wrap_status = WR_MAYBE;
265 }
266 }
267
268 /*
269 * Alas, we cannot wrap rpc/tcp services.
270 */
271 if (wrap_status == WR_YES && STR_EQ(protocol, "rpc/tcp"))
272 tcpd_warn("%s: cannot wrap rpc/tcp services", tcpd_proc_name);
273
274 inet_set(tcpd_proc_name, wrap_status);
275 }
276
277 /* inet_set - remember service status */
278
inet_set(name,type)279 void inet_set(name, type)
280 char *name;
281 int type;
282 {
283 struct inet_ent *ip =
284 (struct inet_ent *) malloc(sizeof(struct inet_ent) + strlen(name));
285
286 if (ip == 0) {
287 fprintf(stderr, "out of memory\n");
288 exit(1);
289 }
290 ip->next = inet_list;
291 strcpy(ip->name, name);
292 ip->type = type;
293 inet_list = ip;
294 }
295
296 /* inet_get - look up service status */
297
inet_get(name)298 int inet_get(name)
299 char *name;
300 {
301 struct inet_ent *ip;
302
303 if (inet_list == 0)
304 return (WR_MAYBE);
305
306 for (ip = inet_list; ip; ip = ip->next)
307 if (STR_EQ(ip->name, name))
308 return (ip->type);
309
310 return (-1);
311 }
312
313 /* base_name - compute last pathname component */
314
base_name(path)315 static char *base_name(path)
316 char *path;
317 {
318 char *cp;
319
320 if ((cp = strrchr(path, '/')) != 0)
321 path = cp + 1;
322 return (path);
323 }
324