1 /* $NetBSD: getnetpath.c,v 1.3 2000/07/06 03:10:34 christos Exp $ */
2
3 /*-
4 * SPDX-License-Identifier: BSD-3-Clause
5 *
6 * Copyright (c) 2009, Sun Microsystems, Inc.
7 * All rights reserved.
8 *
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions are met:
11 * - Redistributions of source code must retain the above copyright notice,
12 * this list of conditions and the following disclaimer.
13 * - Redistributions in binary form must reproduce the above copyright notice,
14 * this list of conditions and the following disclaimer in the documentation
15 * and/or other materials provided with the distribution.
16 * - Neither the name of Sun Microsystems, Inc. nor the names of its
17 * contributors may be used to endorse or promote products derived
18 * from this software without specific prior written permission.
19 *
20 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
21 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
24 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
25 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
26 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
27 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
28 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
29 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
30 * POSSIBILITY OF SUCH DAMAGE.
31 */
32
33 #if defined(LIBC_SCCS) && !defined(lint)
34 static char sccsid[] = "@(#)getnetpath.c 1.11 91/12/19 SMI";
35 #endif
36 #include <sys/cdefs.h>
37 __FBSDID("$FreeBSD$");
38
39 /*
40 * Copyright (c) 1989 by Sun Microsystems, Inc.
41 */
42
43 #include "namespace.h"
44 #include <stdio.h>
45 #include <errno.h>
46 #include <netconfig.h>
47 #include <stdlib.h>
48 #include <string.h>
49 #include <syslog.h>
50 #include "un-namespace.h"
51
52 /*
53 * internal structure to keep track of a netpath "session"
54 */
55 struct netpath_chain {
56 struct netconfig *ncp; /* an nconf entry */
57 struct netpath_chain *nchain_next; /* next nconf entry allocated */
58 };
59
60
61 struct netpath_vars {
62 int valid; /* token that indicates a valid netpath_vars */
63 void *nc_handlep; /* handle for current netconfig "session" */
64 char *netpath; /* pointer to current view-point in NETPATH */
65 char *netpath_start; /* pointer to start of our copy of NETPATH */
66 struct netpath_chain *ncp_list; /* list of nconfs allocated this session*/
67 };
68
69 #define NP_VALID 0xf00d
70 #define NP_INVALID 0
71
72 char *_get_next_token(char *, int);
73
74
75 /*
76 * A call to setnetpath() establishes a NETPATH "session". setnetpath()
77 * must be called before the first call to getnetpath(). A "handle" is
78 * returned to distinguish the session; this handle should be passed
79 * subsequently to getnetpath(). (Handles are used to allow for nested calls
80 * to setnetpath()).
81 * If setnetpath() is unable to establish a session (due to lack of memory
82 * resources, or the absence of the /etc/netconfig file), a NULL pointer is
83 * returned.
84 */
85
86 void *
setnetpath(void)87 setnetpath(void)
88 {
89
90 struct netpath_vars *np_sessionp; /* this session's variables */
91 char *npp; /* NETPATH env variable */
92
93 #ifdef MEM_CHK
94 malloc_debug(1);
95 #endif
96
97 if ((np_sessionp =
98 (struct netpath_vars *)malloc(sizeof (struct netpath_vars))) == NULL) {
99 return (NULL);
100 }
101 if ((np_sessionp->nc_handlep = setnetconfig()) == NULL) {
102 syslog (LOG_ERR, "rpc: failed to open " NETCONFIG);
103 goto failed;
104 }
105 np_sessionp->valid = NP_VALID;
106 np_sessionp->ncp_list = NULL;
107 if ((npp = getenv(NETPATH)) == NULL) {
108 np_sessionp->netpath = NULL;
109 } else {
110 (void) endnetconfig(np_sessionp->nc_handlep);/* won't need nc session*/
111 np_sessionp->nc_handlep = NULL;
112 if ((np_sessionp->netpath = malloc(strlen(npp)+1)) == NULL)
113 goto failed;
114 else {
115 (void) strcpy(np_sessionp->netpath, npp);
116 }
117 }
118 np_sessionp->netpath_start = np_sessionp->netpath;
119 return ((void *)np_sessionp);
120
121 failed:
122 free(np_sessionp);
123 return (NULL);
124 }
125
126 /*
127 * When first called, getnetpath() returns a pointer to the netconfig
128 * database entry corresponding to the first valid NETPATH component. The
129 * netconfig entry is formatted as a struct netconfig.
130 * On each subsequent call, getnetpath returns a pointer to the netconfig
131 * entry that corresponds to the next valid NETPATH component. getnetpath
132 * can thus be used to search the netconfig database for all networks
133 * included in the NETPATH variable.
134 * When NETPATH has been exhausted, getnetpath() returns NULL. It returns
135 * NULL and sets errno in case of an error (e.g., setnetpath was not called
136 * previously).
137 * getnetpath() silently ignores invalid NETPATH components. A NETPATH
138 * compnent is invalid if there is no corresponding entry in the netconfig
139 * database.
140 * If the NETPATH variable is unset, getnetpath() behaves as if NETPATH
141 * were set to the sequence of default or visible networks in the netconfig
142 * database, in the order in which they are listed.
143 */
144
145 struct netconfig *
getnetpath(void * handlep)146 getnetpath(void *handlep)
147 {
148 struct netpath_vars *np_sessionp = (struct netpath_vars *)handlep;
149 struct netconfig *ncp = NULL; /* temp. holds a netconfig session */
150 struct netpath_chain *chainp; /* holds chain of ncp's we alloc */
151 char *npp; /* holds current NETPATH */
152
153 if (np_sessionp == NULL || np_sessionp->valid != NP_VALID) {
154 errno = EINVAL;
155 return (NULL);
156 }
157 if (np_sessionp->netpath_start == NULL) { /* NETPATH was not set */
158 do { /* select next visible network */
159 if (np_sessionp->nc_handlep == NULL) {
160 np_sessionp->nc_handlep = setnetconfig();
161 if (np_sessionp->nc_handlep == NULL)
162 syslog (LOG_ERR, "rpc: failed to open " NETCONFIG);
163 }
164 if ((ncp = getnetconfig(np_sessionp->nc_handlep)) == NULL) {
165 return(NULL);
166 }
167 } while ((ncp->nc_flag & NC_VISIBLE) == 0);
168 return (ncp);
169 }
170 /*
171 * Find first valid network ID in netpath.
172 */
173 while ((npp = np_sessionp->netpath) != NULL && strlen(npp) != 0) {
174 np_sessionp->netpath = _get_next_token(npp, ':');
175 /*
176 * npp is a network identifier.
177 */
178 if ((ncp = getnetconfigent(npp)) != NULL) {
179 chainp = (struct netpath_chain *) /* cobble alloc chain entry */
180 malloc(sizeof (struct netpath_chain));
181 chainp->ncp = ncp;
182 chainp->nchain_next = NULL;
183 if (np_sessionp->ncp_list == NULL) {
184 np_sessionp->ncp_list = chainp;
185 } else {
186 np_sessionp->ncp_list->nchain_next = chainp;
187 }
188 return (ncp);
189 }
190 /* couldn't find this token in the database; go to next one. */
191 }
192 return (NULL);
193 }
194
195 /*
196 * endnetpath() may be called to unbind NETPATH when processing is complete,
197 * releasing resources for reuse. It returns 0 on success and -1 on failure
198 * (e.g. if setnetpath() was not called previously.
199 */
200 int
endnetpath(void * handlep)201 endnetpath(void *handlep)
202 {
203 struct netpath_vars *np_sessionp = (struct netpath_vars *)handlep;
204 struct netpath_chain *chainp, *lastp;
205
206 if (np_sessionp == NULL || np_sessionp->valid != NP_VALID) {
207 errno = EINVAL;
208 return (-1);
209 }
210 if (np_sessionp->nc_handlep != NULL)
211 endnetconfig(np_sessionp->nc_handlep);
212 if (np_sessionp->netpath_start != NULL)
213 free(np_sessionp->netpath_start);
214 for (chainp = np_sessionp->ncp_list; chainp != NULL;
215 lastp=chainp, chainp=chainp->nchain_next, free(lastp)) {
216 freenetconfigent(chainp->ncp);
217 }
218 free(np_sessionp);
219 #ifdef MEM_CHK
220 if (malloc_verify() == 0) {
221 fprintf(stderr, "memory heap corrupted in endnetpath\n");
222 exit(1);
223 }
224 #endif
225 return (0);
226 }
227
228
229
230 /*
231 * Returns pointer to the rest-of-the-string after the current token.
232 * The token itself starts at arg, and we null terminate it. We return NULL
233 * if either the arg is empty, or if this is the last token.
234 *
235 * npp - string
236 * token - char to parse string for
237 */
238 char *
_get_next_token(char * npp,int token)239 _get_next_token(char *npp, int token)
240 {
241 char *cp; /* char pointer */
242 char *np; /* netpath pointer */
243 char *ep; /* escape pointer */
244
245 if ((cp = strchr(npp, token)) == NULL) {
246 return (NULL);
247 }
248 /*
249 * did find a token, but it might be escaped.
250 */
251 if ((cp > npp) && (cp[-1] == '\\')) {
252 /* if slash was also escaped, carry on, otherwise find next token */
253 if ((cp > npp + 1) && (cp[-2] != '\\')) {
254 /* shift r-o-s onto the escaped token */
255 strcpy(&cp[-1], cp); /* XXX: overlapping string copy */
256 /*
257 * Do a recursive call.
258 * We don't know how many escaped tokens there might be.
259 */
260 return (_get_next_token(cp, token));
261 }
262 }
263
264 *cp++ = '\0'; /* null-terminate token */
265 /* get rid of any backslash escapes */
266 ep = npp;
267 while ((np = strchr(ep, '\\')) != NULL) {
268 if (np[1] == '\\')
269 np++;
270 strcpy(np, (ep = &np[1])); /* XXX: overlapping string copy */
271 }
272 return (cp); /* return ptr to r-o-s */
273 }
274