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 /*
37 * Copyright (c) 1989 by Sun Microsystems, Inc.
38 */
39
40 #include "namespace.h"
41 #include <stdio.h>
42 #include <errno.h>
43 #include <netconfig.h>
44 #include <stdlib.h>
45 #include <string.h>
46 #include <syslog.h>
47 #include "un-namespace.h"
48
49 /*
50 * internal structure to keep track of a netpath "session"
51 */
52 struct netpath_chain {
53 struct netconfig *ncp; /* an nconf entry */
54 struct netpath_chain *nchain_next; /* next nconf entry allocated */
55 };
56
57
58 struct netpath_vars {
59 int valid; /* token that indicates a valid netpath_vars */
60 void *nc_handlep; /* handle for current netconfig "session" */
61 char *netpath; /* pointer to current view-point in NETPATH */
62 char *netpath_start; /* pointer to start of our copy of NETPATH */
63 struct netpath_chain *ncp_list; /* list of nconfs allocated this session*/
64 };
65
66 #define NP_VALID 0xf00d
67 #define NP_INVALID 0
68
69 char *_get_next_token(char *, int);
70
71
72 /*
73 * A call to setnetpath() establishes a NETPATH "session". setnetpath()
74 * must be called before the first call to getnetpath(). A "handle" is
75 * returned to distinguish the session; this handle should be passed
76 * subsequently to getnetpath(). (Handles are used to allow for nested calls
77 * to setnetpath()).
78 * If setnetpath() is unable to establish a session (due to lack of memory
79 * resources, or the absence of the /etc/netconfig file), a NULL pointer is
80 * returned.
81 */
82
83 void *
setnetpath(void)84 setnetpath(void)
85 {
86
87 struct netpath_vars *np_sessionp; /* this session's variables */
88 char *npp; /* NETPATH env variable */
89
90 #ifdef MEM_CHK
91 malloc_debug(1);
92 #endif
93
94 if ((np_sessionp =
95 (struct netpath_vars *)malloc(sizeof (struct netpath_vars))) == NULL) {
96 return (NULL);
97 }
98 if ((np_sessionp->nc_handlep = setnetconfig()) == NULL) {
99 syslog (LOG_ERR, "rpc: failed to open " NETCONFIG);
100 goto failed;
101 }
102 np_sessionp->valid = NP_VALID;
103 np_sessionp->ncp_list = NULL;
104 if ((npp = getenv(NETPATH)) == NULL) {
105 np_sessionp->netpath = NULL;
106 } else {
107 (void) endnetconfig(np_sessionp->nc_handlep);/* won't need nc session*/
108 np_sessionp->nc_handlep = NULL;
109 if ((np_sessionp->netpath = malloc(strlen(npp)+1)) == NULL)
110 goto failed;
111 else {
112 (void) strcpy(np_sessionp->netpath, npp);
113 }
114 }
115 np_sessionp->netpath_start = np_sessionp->netpath;
116 return ((void *)np_sessionp);
117
118 failed:
119 free(np_sessionp);
120 return (NULL);
121 }
122
123 /*
124 * When first called, getnetpath() returns a pointer to the netconfig
125 * database entry corresponding to the first valid NETPATH component. The
126 * netconfig entry is formatted as a struct netconfig.
127 * On each subsequent call, getnetpath returns a pointer to the netconfig
128 * entry that corresponds to the next valid NETPATH component. getnetpath
129 * can thus be used to search the netconfig database for all networks
130 * included in the NETPATH variable.
131 * When NETPATH has been exhausted, getnetpath() returns NULL. It returns
132 * NULL and sets errno in case of an error (e.g., setnetpath was not called
133 * previously).
134 * getnetpath() silently ignores invalid NETPATH components. A NETPATH
135 * component is invalid if there is no corresponding entry in the netconfig
136 * database.
137 * If the NETPATH variable is unset, getnetpath() behaves as if NETPATH
138 * were set to the sequence of default or visible networks in the netconfig
139 * database, in the order in which they are listed.
140 */
141
142 struct netconfig *
getnetpath(void * handlep)143 getnetpath(void *handlep)
144 {
145 struct netpath_vars *np_sessionp = (struct netpath_vars *)handlep;
146 struct netconfig *ncp = NULL; /* temp. holds a netconfig session */
147 struct netpath_chain *chainp; /* holds chain of ncp's we alloc */
148 char *npp; /* holds current NETPATH */
149
150 if (np_sessionp == NULL || np_sessionp->valid != NP_VALID) {
151 errno = EINVAL;
152 return (NULL);
153 }
154 if (np_sessionp->netpath_start == NULL) { /* NETPATH was not set */
155 do { /* select next visible network */
156 if (np_sessionp->nc_handlep == NULL) {
157 np_sessionp->nc_handlep = setnetconfig();
158 if (np_sessionp->nc_handlep == NULL)
159 syslog (LOG_ERR, "rpc: failed to open " NETCONFIG);
160 }
161 if ((ncp = getnetconfig(np_sessionp->nc_handlep)) == NULL) {
162 return(NULL);
163 }
164 } while ((ncp->nc_flag & NC_VISIBLE) == 0);
165 return (ncp);
166 }
167 /*
168 * Find first valid network ID in netpath.
169 */
170 while ((npp = np_sessionp->netpath) != NULL && strlen(npp) != 0) {
171 np_sessionp->netpath = _get_next_token(npp, ':');
172 /*
173 * npp is a network identifier.
174 */
175 if ((ncp = getnetconfigent(npp)) != NULL) {
176 chainp = (struct netpath_chain *) /* cobble alloc chain entry */
177 malloc(sizeof (struct netpath_chain));
178 chainp->ncp = ncp;
179 chainp->nchain_next = NULL;
180 if (np_sessionp->ncp_list == NULL) {
181 np_sessionp->ncp_list = chainp;
182 } else {
183 np_sessionp->ncp_list->nchain_next = chainp;
184 }
185 return (ncp);
186 }
187 /* couldn't find this token in the database; go to next one. */
188 }
189 return (NULL);
190 }
191
192 /*
193 * endnetpath() may be called to unbind NETPATH when processing is complete,
194 * releasing resources for reuse. It returns 0 on success and -1 on failure
195 * (e.g. if setnetpath() was not called previously.
196 */
197 int
endnetpath(void * handlep)198 endnetpath(void *handlep)
199 {
200 struct netpath_vars *np_sessionp = (struct netpath_vars *)handlep;
201 struct netpath_chain *chainp, *lastp;
202
203 if (np_sessionp == NULL || np_sessionp->valid != NP_VALID) {
204 errno = EINVAL;
205 return (-1);
206 }
207 if (np_sessionp->nc_handlep != NULL)
208 endnetconfig(np_sessionp->nc_handlep);
209 if (np_sessionp->netpath_start != NULL)
210 free(np_sessionp->netpath_start);
211 for (chainp = np_sessionp->ncp_list; chainp != NULL;
212 lastp=chainp, chainp=chainp->nchain_next, free(lastp)) {
213 freenetconfigent(chainp->ncp);
214 }
215 free(np_sessionp);
216 #ifdef MEM_CHK
217 if (malloc_verify() == 0) {
218 fprintf(stderr, "memory heap corrupted in endnetpath\n");
219 exit(1);
220 }
221 #endif
222 return (0);
223 }
224
225
226
227 /*
228 * Returns pointer to the rest-of-the-string after the current token.
229 * The token itself starts at arg, and we null terminate it. We return NULL
230 * if either the arg is empty, or if this is the last token.
231 *
232 * npp - string
233 * token - char to parse string for
234 */
235 char *
_get_next_token(char * npp,int token)236 _get_next_token(char *npp, int token)
237 {
238 char *cp; /* char pointer */
239 char *np; /* netpath pointer */
240 char *ep; /* escape pointer */
241
242 if ((cp = strchr(npp, token)) == NULL) {
243 return (NULL);
244 }
245 /*
246 * did find a token, but it might be escaped.
247 */
248 if ((cp > npp) && (cp[-1] == '\\')) {
249 /* if slash was also escaped, carry on, otherwise find next token */
250 if ((cp > npp + 1) && (cp[-2] != '\\')) {
251 /* shift r-o-s onto the escaped token */
252 strcpy(&cp[-1], cp); /* XXX: overlapping string copy */
253 /*
254 * Do a recursive call.
255 * We don't know how many escaped tokens there might be.
256 */
257 return (_get_next_token(cp, token));
258 }
259 }
260
261 *cp++ = '\0'; /* null-terminate token */
262 /* get rid of any backslash escapes */
263 ep = npp;
264 while ((np = strchr(ep, '\\')) != NULL) {
265 if (np[1] == '\\')
266 np++;
267 strcpy(np, (ep = &np[1])); /* XXX: overlapping string copy */
268 }
269 return (cp); /* return ptr to r-o-s */
270 }
271