xref: /titanic_52/usr/src/lib/libnsl/rpc/netname.c (revision 4df55fde49134f9735f84011f23a767c75e393c7)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9  * or http://www.opensolaris.org/os/licensing.
10  * See the License for the specific language governing permissions
11  * and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL HEADER in each
14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15  * If applicable, add the following below this CDDL HEADER, with the
16  * fields enclosed by brackets "[]" replaced with your own identifying
17  * information: Portions Copyright [yyyy] [name of copyright owner]
18  *
19  * CDDL HEADER END
20  */
21 
22 /*
23  * Copyright 2009 Sun Microsystems, Inc.  All rights reserved.
24  * Use is subject to license terms.
25  */
26 /* Copyright (c) 1983, 1984, 1985, 1986, 1987, 1988, 1989 AT&T */
27 /* All Rights Reserved */
28 /*
29  * Portions of this source code were derived from Berkeley
30  * 4.3 BSD under license from the Regents of the University of
31  * California.
32  */
33 /*
34  * ==== hack-attack:  possibly MT-safe but definitely not MT-hot.
35  * ==== turn this into a real switch frontend and backends
36  *
37  * Well, at least the API doesn't involve pointers-to-static.
38  */
39 
40 
41 /*
42  * netname utility routines (getnetname, user2netname, host2netname).
43  *
44  * Convert from unix names (uid, gid) to network wide names.
45  * This module is operating system dependent!
46  * What we define here will work with any unix system that has adopted
47  * the Sun NIS domain architecture.
48  */
49 
50 #undef NIS
51 
52 #include "mt.h"
53 #include "rpc_mt.h"
54 #include <stdio.h>
55 #include <stdlib.h>
56 #include <unistd.h>
57 #include <sys/types.h>
58 #include <ctype.h>
59 #include <string.h>
60 #include <syslog.h>
61 #include <sys/param.h>
62 #include <rpc/rpc.h>
63 #include <rpcsvc/nis.h>
64 #include <rpcsvc/nis_dhext.h>
65 #include <nsswitch.h>
66 #include <syslog.h>
67 #include <errno.h>
68 
69 #ifndef MAXHOSTNAMELEN
70 #define	MAXHOSTNAMELEN 256
71 #endif
72 #ifndef NGROUPS
73 #define	NGROUPS 16
74 #endif
75 
76 /*
77  * the value for NOBODY_UID is set by the SVID. The following define also
78  * appears in netnamer.c
79  */
80 
81 #define	NOBODY_UID 60001
82 
83 extern int getdomainname();
84 extern int key_call();
85 #define	OPSYS_LEN 4
86 static const char *OPSYS = "unix";
87 
88 /*
89  * default publickey policy:
90  *	publickey: nis [NOTFOUND = return] files
91  */
92 
93 
94 /*	NSW_NOTSUCCESS  NSW_NOTFOUND   NSW_UNAVAIL    NSW_TRYAGAIN */
95 #define	DEF_ACTION {__NSW_RETURN, __NSW_RETURN, __NSW_CONTINUE, __NSW_CONTINUE}
96 
97 static struct __nsw_lookup lookup_files = {"files", DEF_ACTION, NULL, NULL},
98 		lookup_nis = {"nis", DEF_ACTION, NULL, &lookup_files};
99 static struct __nsw_switchconfig publickey_default =
100 			{0, "publickey", 2, &lookup_nis};
101 
102 static mutex_t serialize_netname = ERRORCHECKMUTEX;
103 
104 
105 #define	MAXIPRINT	(11)	/* max length of printed integer */
106 
107 /*
108  * Convert unix cred to network-name by concatenating the
109  * 3 pieces of information <opsys type> <uid> <domain>.
110  */
111 
112 static int
113 user2netname_nis(int *err, char netname[MAXNETNAMELEN + 1], uid_t uid,
114 								char *domain)
115 {
116 	int i;
117 	char *dfltdom;
118 	if (domain == NULL) {
119 		if (__rpc_get_default_domain(&dfltdom) != 0) {
120 			*err = __NSW_UNAVAIL;
121 			return (0);
122 		}
123 		domain = dfltdom;
124 	}
125 	if ((strlen(domain) + OPSYS_LEN + 3 + MAXIPRINT) >
126 	    (size_t)MAXNETNAMELEN) {
127 		*err = __NSW_UNAVAIL;
128 		return (0);
129 	}
130 	(void) snprintf(netname, MAXNETNAMELEN + 1,
131 	    "%s.%d@%s", OPSYS, (int)uid, domain);
132 	i = strlen(netname);
133 	if (netname[i-1] == '.')
134 		netname[i-1] = '\0';
135 	*err = __NSW_SUCCESS;
136 	return (1);
137 }
138 
139 /*
140  * Figure out my fully qualified network name
141  */
142 int
143 getnetname(char name[MAXNETNAMELEN + 1])
144 {
145 	uid_t uid;
146 
147 	uid = geteuid();
148 	if (uid == 0)
149 		return (host2netname(name, NULL, NULL));
150 	return (user2netname(name, uid, NULL));
151 }
152 
153 
154 /*
155  * Figure out the fully qualified network name for the given uid.
156  * This is a private interface.
157  */
158 int
159 __getnetnamebyuid(char name[MAXNETNAMELEN + 1], uid_t uid)
160 {
161 	if (uid == 0)
162 		return (host2netname(name, NULL, NULL));
163 	return (user2netname(name, uid, NULL));
164 }
165 
166 /*
167  * Convert unix cred to network-name
168  *
169  * It uses the publickey policy in the /etc/nsswitch.conf file
170  * (Unless the netname is "nobody", which is special cased).
171  * If there is no publickey policy in /etc/nsswitch.conf,
172  * the default publickey policy is used, which is
173  *	publickey: nis [NOTFOUND=return] files
174  * Note that for the non-nisplus case, there is no failover
175  * so only the first entry would be relevant for those cases.
176  */
177 int
178 user2netname(char netname[MAXNETNAMELEN + 1], const uid_t uid,
179 							const char *domain)
180 {
181 	struct __nsw_switchconfig *conf;
182 	struct __nsw_lookup *look;
183 	int needfree = 1, res = 0;
184 	enum __nsw_parse_err perr;
185 	int err;
186 
187 	/*
188 	 * Take care of the special case of "nobody". If the uid is
189 	 * the value assigned by the SVID for nobody, return the string
190 	 * "nobody".
191 	 */
192 
193 	if (uid == NOBODY_UID) {
194 		(void) strlcpy(netname, "nobody", sizeof (netname));
195 		return (1);
196 	}
197 
198 	netname[0] = '\0';  /* make null first (no need for memset) */
199 
200 	if (mutex_lock(&serialize_netname) == EDEADLK) {
201 		/*
202 		 * This thread already holds this lock. This scenario
203 		 * occurs when a process requires a netname which
204 		 * itself requires a netname to look up. As we clearly
205 		 * can't continue like this we return 'nobody'.
206 		 */
207 		(void) strlcpy(netname, "nobody", sizeof (netname));
208 		return (1);
209 	}
210 
211 	conf = __nsw_getconfig("publickey", &perr);
212 	if (!conf) {
213 		conf = &publickey_default;
214 		needfree = 0;
215 	}
216 
217 	for (look = conf->lookups; look; look = look->next) {
218 		/* ldap, nis, and files all do the same thing. */
219 		if (strcmp(look->service_name, "ldap") == 0 ||
220 		    strcmp(look->service_name, "nis") == 0 ||
221 		    strcmp(look->service_name, "files") == 0)
222 			res = user2netname_nis(&err,
223 			    netname, uid, (char *)domain);
224 		else {
225 			syslog(LOG_INFO,
226 			    "user2netname: unknown nameservice \
227 					for publickey info '%s'\n",
228 			    look->service_name);
229 			err = __NSW_UNAVAIL;
230 		}
231 		switch (look->actions[err]) {
232 			case __NSW_CONTINUE :
233 				break;
234 			case __NSW_RETURN :
235 				if (needfree)
236 					__nsw_freeconfig(conf);
237 				(void) mutex_unlock(&serialize_netname);
238 				return (res);
239 			default :
240 				syslog(LOG_ERR,
241 			"user2netname: Unknown action for nameservice '%s'",
242 				    look->service_name);
243 			}
244 	}
245 	if (needfree)
246 		__nsw_freeconfig(conf);
247 	(void) mutex_unlock(&serialize_netname);
248 	return (0);
249 }
250 
251 
252 /*
253  * Convert host to network-name
254  * This routine returns following netnames given the host and domain
255  * arguments defined below: (domainname=y.z)
256  *	  Arguments
257  *	host	domain		netname
258  *	----	------		-------
259  *	-	-		unix.m@y.z (hostname=m)
260  *	-	a.b		unix.m@a.b (hostname=m)
261  *	-	-		unix.m@y.z (hostname=m.w.x)
262  *	-	a.b		unix.m@a.b (hostname=m.w.x)
263  *	h	-		unix.h@y.z
264  *	h	a.b		unix.h@a.b
265  *	h.w.x	-		unix.h@w.x
266  *	h.w.x	a.b		unix.h@a.b
267  */
268 int
269 host2netname(char netname[MAXNETNAMELEN + 1], const char *host,
270 							const char *domain)
271 {
272 	char *p;
273 	char hostname[MAXHOSTNAMELEN + 1];
274 	char domainname[MAXHOSTNAMELEN + 1];
275 	char *dot_in_host;
276 	int i;
277 	size_t len;
278 
279 	netname[0] = '\0';  /* make null first (no need for memset) */
280 
281 	if (host == NULL) {
282 		(void) strncpy(hostname, nis_local_host(), sizeof (hostname));
283 		p = (char *)strchr(hostname, '.');
284 		if (p) {
285 			*p++ = '\0';
286 			/* if no domain passed, use tail of nis_local_host() */
287 			if (domain == NULL) {
288 				domain = p;
289 			}
290 		}
291 	} else {
292 		len = strlen(host);
293 		if (len >= sizeof (hostname)) {
294 			return (0);
295 		}
296 		(void) strcpy(hostname, host);
297 	}
298 
299 	dot_in_host = (char *)strchr(hostname, '.');
300 	if (domain == NULL) {
301 		p = dot_in_host;
302 		if (p) {
303 			p = (char *)nis_domain_of(hostname);
304 			len = strlen(p);
305 			if (len >= sizeof (domainname)) {
306 				return (0);
307 			}
308 			(void) strcpy(domainname, p);
309 		} else {
310 			domainname[0] = NULL;
311 			if (getdomainname(domainname, MAXHOSTNAMELEN) < 0)
312 				return (0);
313 		}
314 	} else {
315 		len = strlen(domain);
316 		if (len >= sizeof (domainname)) {
317 			return (0);
318 		}
319 		(void) strcpy(domainname, domain);
320 	}
321 
322 	i = strlen(domainname);
323 	if (i == 0)
324 		/* No domainname */
325 		return (0);
326 	if (domainname[i - 1] == '.')
327 		domainname[i - 1] = 0;
328 
329 	if (dot_in_host) {  /* strip off rest of name */
330 		*dot_in_host = '\0';
331 	}
332 
333 	if ((strlen(domainname) + strlen(hostname) + OPSYS_LEN + 3)
334 	    > (size_t)MAXNETNAMELEN) {
335 		return (0);
336 	}
337 
338 	(void) snprintf(netname, MAXNETNAMELEN + 1,
339 	    "%s.%s@%s", OPSYS, hostname, domainname);
340 	return (1);
341 }
342