xref: /illumos-gate/usr/src/lib/libnsl/rpc/netname.c (revision 89fbfe0d)
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  * netname utility routines (getnetname, user2netname, host2netname).
42  *
43  * Convert from unix names (uid, gid) to network wide names.
44  * This module is operating system dependent!
45  * What we define here will work with any unix system that has adopted
46  * the Sun NIS domain architecture.
47  */
48 
49 #undef NIS
50 
51 #include "mt.h"
52 #include "rpc_mt.h"
53 #include <stdio.h>
54 #include <stdlib.h>
55 #include <unistd.h>
56 #include <sys/types.h>
57 #include <ctype.h>
58 #include <string.h>
59 #include <syslog.h>
60 #include <sys/param.h>
61 #include <rpc/rpc.h>
62 #include <rpcsvc/nis.h>
63 #include <rpcsvc/nis_dhext.h>
64 #include <nsswitch.h>
65 #include <syslog.h>
66 #include <errno.h>
67 
68 #ifndef MAXHOSTNAMELEN
69 #define	MAXHOSTNAMELEN 256
70 #endif
71 #ifndef NGROUPS
72 #define	NGROUPS 16
73 #endif
74 
75 /*
76  * the value for NOBODY_UID is set by the SVID. The following define also
77  * appears in netnamer.c
78  */
79 
80 #define	NOBODY_UID 60001
81 
82 extern int getdomainname();
83 extern int key_call();
84 #define	OPSYS_LEN 4
85 static const char *OPSYS = "unix";
86 
87 /*
88  * default publickey policy:
89  *	publickey: nis [NOTFOUND = return] files
90  */
91 
92 
93 /*	NSW_NOTSUCCESS  NSW_NOTFOUND   NSW_UNAVAIL    NSW_TRYAGAIN */
94 #define	DEF_ACTION {__NSW_RETURN, __NSW_RETURN, __NSW_CONTINUE, __NSW_CONTINUE}
95 
96 static struct __nsw_lookup lookup_files = {"files", DEF_ACTION, NULL, NULL},
97 		lookup_nis = {"nis", DEF_ACTION, NULL, &lookup_files};
98 static struct __nsw_switchconfig publickey_default =
99 			{0, "publickey", 2, &lookup_nis};
100 
101 static mutex_t serialize_netname = ERRORCHECKMUTEX;
102 
103 
104 #define	MAXIPRINT	(11)	/* max length of printed integer */
105 
106 /*
107  * Convert unix cred to network-name by concatenating the
108  * 3 pieces of information <opsys type> <uid> <domain>.
109  */
110 
111 static int
user2netname_nis(int * err,char netname[MAXNETNAMELEN+1],uid_t uid,char * domain)112 user2netname_nis(int *err, char netname[MAXNETNAMELEN + 1], uid_t uid,
113     char *domain)
114 {
115 	int i;
116 	char *dfltdom;
117 	if (domain == NULL) {
118 		if (__rpc_get_default_domain(&dfltdom) != 0) {
119 			*err = __NSW_UNAVAIL;
120 			return (0);
121 		}
122 		domain = dfltdom;
123 	}
124 	if ((strlen(domain) + OPSYS_LEN + 3 + MAXIPRINT) >
125 	    (size_t)MAXNETNAMELEN) {
126 		*err = __NSW_UNAVAIL;
127 		return (0);
128 	}
129 	(void) snprintf(netname, MAXNETNAMELEN + 1,
130 	    "%s.%d@%s", OPSYS, (int)uid, domain);
131 	i = strlen(netname);
132 	if (netname[i-1] == '.')
133 		netname[i-1] = '\0';
134 	*err = __NSW_SUCCESS;
135 	return (1);
136 }
137 
138 /*
139  * Figure out my fully qualified network name
140  */
141 int
getnetname(char * name)142 getnetname(char *name)
143 {
144 	uid_t uid;
145 
146 	uid = geteuid();
147 	if (uid == 0)
148 		return (host2netname(name, NULL, NULL));
149 	return (user2netname(name, uid, NULL));
150 }
151 
152 
153 /*
154  * Figure out the fully qualified network name for the given uid.
155  * This is a private interface.
156  */
157 int
__getnetnamebyuid(char name[MAXNETNAMELEN+1],uid_t uid)158 __getnetnamebyuid(char name[MAXNETNAMELEN + 1], uid_t uid)
159 {
160 	if (uid == 0)
161 		return (host2netname(name, NULL, NULL));
162 	return (user2netname(name, uid, NULL));
163 }
164 
165 /*
166  * Convert unix cred to network-name
167  *
168  * It uses the publickey policy in the /etc/nsswitch.conf file
169  * (Unless the netname is "nobody", which is special cased).
170  * If there is no publickey policy in /etc/nsswitch.conf,
171  * the default publickey policy is used, which is
172  *	publickey: nis [NOTFOUND=return] files
173  * Note that for the non-nisplus case, there is no failover
174  * so only the first entry would be relevant for those cases.
175  */
176 int
user2netname(char * netname,const uid_t uid,const char * domain)177 user2netname(char *netname, const uid_t uid, const char *domain)
178 {
179 	struct __nsw_switchconfig *conf;
180 	struct __nsw_lookup *look;
181 	int needfree = 1, res = 0;
182 	enum __nsw_parse_err perr;
183 	int err;
184 
185 	/*
186 	 * Take care of the special case of "nobody". If the uid is
187 	 * the value assigned by the SVID for nobody, return the string
188 	 * "nobody".
189 	 */
190 
191 	if (uid == NOBODY_UID) {
192 		(void) strlcpy(netname, "nobody", MAXNETNAMELEN + 1);
193 		return (1);
194 	}
195 
196 	netname[0] = '\0';  /* make null first (no need for memset) */
197 
198 	if (mutex_lock(&serialize_netname) == EDEADLK) {
199 		/*
200 		 * This thread already holds this lock. This scenario
201 		 * occurs when a process requires a netname which
202 		 * itself requires a netname to look up. As we clearly
203 		 * can't continue like this we return 'nobody'.
204 		 */
205 		(void) strlcpy(netname, "nobody", MAXNETNAMELEN + 1);
206 		return (1);
207 	}
208 
209 	conf = __nsw_getconfig("publickey", &perr);
210 	if (!conf) {
211 		conf = &publickey_default;
212 		needfree = 0;
213 	}
214 
215 	for (look = conf->lookups; look; look = look->next) {
216 		/* ldap, nis, and files all do the same thing. */
217 		if (strcmp(look->service_name, "ldap") == 0 ||
218 		    strcmp(look->service_name, "nis") == 0 ||
219 		    strcmp(look->service_name, "files") == 0)
220 			res = user2netname_nis(&err,
221 			    netname, uid, (char *)domain);
222 		else {
223 			syslog(LOG_INFO,
224 			    "user2netname: unknown nameservice \
225 					for publickey info '%s'\n",
226 			    look->service_name);
227 			err = __NSW_UNAVAIL;
228 		}
229 		switch (look->actions[err]) {
230 			case __NSW_CONTINUE :
231 				break;
232 			case __NSW_RETURN :
233 				if (needfree)
234 					(void) __nsw_freeconfig(conf);
235 				(void) mutex_unlock(&serialize_netname);
236 				return (res);
237 			default :
238 				syslog(LOG_ERR,
239 			"user2netname: Unknown action for nameservice '%s'",
240 				    look->service_name);
241 			}
242 	}
243 	if (needfree)
244 		(void) __nsw_freeconfig(conf);
245 	(void) mutex_unlock(&serialize_netname);
246 	return (0);
247 }
248 
249 
250 /*
251  * Convert host to network-name
252  * This routine returns following netnames given the host and domain
253  * arguments defined below: (domainname=y.z)
254  *	  Arguments
255  *	host	domain		netname
256  *	----	------		-------
257  *	-	-		unix.m@y.z (hostname=m)
258  *	-	a.b		unix.m@a.b (hostname=m)
259  *	-	-		unix.m@y.z (hostname=m.w.x)
260  *	-	a.b		unix.m@a.b (hostname=m.w.x)
261  *	h	-		unix.h@y.z
262  *	h	a.b		unix.h@a.b
263  *	h.w.x	-		unix.h@w.x
264  *	h.w.x	a.b		unix.h@a.b
265  */
266 int
host2netname(char * netname,const char * host,const char * domain)267 host2netname(char *netname, const char *host, const char *domain)
268 {
269 	char *p;
270 	char hostname[MAXHOSTNAMELEN + 1];
271 	char domainname[MAXHOSTNAMELEN + 1];
272 	char *dot_in_host;
273 	int i;
274 	size_t len;
275 
276 	netname[0] = '\0';  /* make null first (no need for memset) */
277 
278 	if (host == NULL) {
279 		(void) strncpy(hostname, nis_local_host(), sizeof (hostname));
280 		p = (char *)strchr(hostname, '.');
281 		if (p) {
282 			*p++ = '\0';
283 			/* if no domain passed, use tail of nis_local_host() */
284 			if (domain == NULL) {
285 				domain = p;
286 			}
287 		}
288 	} else {
289 		len = strlen(host);
290 		if (len >= sizeof (hostname)) {
291 			return (0);
292 		}
293 		(void) strcpy(hostname, host);
294 	}
295 
296 	dot_in_host = (char *)strchr(hostname, '.');
297 	if (domain == NULL) {
298 		p = dot_in_host;
299 		if (p) {
300 			p = (char *)nis_domain_of(hostname);
301 			len = strlen(p);
302 			if (len >= sizeof (domainname)) {
303 				return (0);
304 			}
305 			(void) strcpy(domainname, p);
306 		} else {
307 			domainname[0] = '\0';
308 			if (getdomainname(domainname, MAXHOSTNAMELEN) < 0)
309 				return (0);
310 		}
311 	} else {
312 		len = strlen(domain);
313 		if (len >= sizeof (domainname)) {
314 			return (0);
315 		}
316 		(void) strcpy(domainname, domain);
317 	}
318 
319 	i = strlen(domainname);
320 	if (i == 0)
321 		/* No domainname */
322 		return (0);
323 	if (domainname[i - 1] == '.')
324 		domainname[i - 1] = 0;
325 
326 	if (dot_in_host) {  /* strip off rest of name */
327 		*dot_in_host = '\0';
328 	}
329 
330 	if ((strlen(domainname) + strlen(hostname) + OPSYS_LEN + 3)
331 	    > (size_t)MAXNETNAMELEN) {
332 		return (0);
333 	}
334 
335 	(void) snprintf(netname, MAXNETNAMELEN + 1,
336 	    "%s.%s@%s", OPSYS, hostname, domainname);
337 	return (1);
338 }
339