xref: /reactos/dll/3rdparty/libtirpc/src/getnetpath.c (revision c2c66aff)
1 /*
2  * Copyright (c) 2009, Sun Microsystems, Inc.
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions are met:
7  * - Redistributions of source code must retain the above copyright notice,
8  *   this list of conditions and the following disclaimer.
9  * - Redistributions in binary form must reproduce the above copyright notice,
10  *   this list of conditions and the following disclaimer in the documentation
11  *   and/or other materials provided with the distribution.
12  * - Neither the name of Sun Microsystems, Inc. nor the names of its
13  *   contributors may be used to endorse or promote products derived
14  *   from this software without specific prior written permission.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
17  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
20  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
21  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
22  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
23  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
24  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
25  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
26  * POSSIBILITY OF SUCH DAMAGE.
27  */
28 //#include <sys/cdefs.h>
29 
30 /*
31  * Copyright (c) 1989 by Sun Microsystems, Inc.
32  */
33 
34 //#include <sys/cdefs.h>
35 #include <wintirpc.h>
36 #include <stdio.h>
37 #include <errno.h>
38 #include <netconfig.h>
39 #include <stdlib.h>
40 #include <string.h>
41 //#include <syslog.h>
42 
43 /*
44  * internal structure to keep track of a netpath "session"
45  */
46 struct netpath_chain {
47     struct netconfig *ncp;  /* an nconf entry */
48     struct netpath_chain *nchain_next;	/* next nconf entry allocated */
49 };
50 
51 
52 struct netpath_vars {
53     int   valid;	    /* token that indicates a valid netpath_vars */
54     void *nc_handlep;	    /* handle for current netconfig "session" */
55     char *netpath;	    /* pointer to current view-point in NETPATH */
56     char *netpath_start;    /* pointer to start of our copy of NETPATH */
57     struct netpath_chain *ncp_list;  /* list of nconfs allocated this session*/
58 };
59 
60 #define NP_VALID	0xf00d
61 #define NP_INVALID	0
62 
63 char *_get_next_token(char *, int);
64 
65 
66 /*
67  * A call to setnetpath() establishes a NETPATH "session".  setnetpath()
68  * must be called before the first call to getnetpath().  A "handle" is
69  * returned to distinguish the session; this handle should be passed
70  * subsequently to getnetpath().  (Handles are used to allow for nested calls
71  * to setnetpath()).
72  * If setnetpath() is unable to establish a session (due to lack of memory
73  * resources, or the absence of the /etc/netconfig file), a NULL pointer is
74  * returned.
75  */
76 
77 void *
setnetpath()78 setnetpath()
79 {
80 
81     struct netpath_vars *np_sessionp;   /* this session's variables */
82     char *npp;				/* NETPATH env variable */
83 
84 #ifdef MEM_CHK
85     malloc_debug(1);
86 #endif
87 
88     if ((np_sessionp =
89 	(struct netpath_vars *)malloc(sizeof (struct netpath_vars))) == NULL) {
90 	return (NULL);
91     }
92     if ((np_sessionp->nc_handlep = setnetconfig()) == NULL) {
93 	//syslog (LOG_ERR, "rpc: failed to open " NETCONFIG);
94 	return (NULL);
95     }
96     np_sessionp->valid = NP_VALID;
97     np_sessionp->ncp_list = NULL;
98     if ((npp = getenv(NETPATH)) == NULL) {
99 	np_sessionp->netpath = NULL;
100     } else {
101 	(void) endnetconfig(np_sessionp->nc_handlep);/* won't need nc session*/
102 	np_sessionp->nc_handlep = NULL;
103 	if ((np_sessionp->netpath = malloc(strlen(npp)+1)) == NULL) {
104 	    free(np_sessionp);
105 	    return (NULL);
106 	} else {
107 	    (void) strcpy(np_sessionp->netpath, npp);
108 	}
109     }
110     np_sessionp->netpath_start = np_sessionp->netpath;
111     return ((void *)np_sessionp);
112 }
113 
114 /*
115  * When first called, getnetpath() returns a pointer to the netconfig
116  * database entry corresponding to the first valid NETPATH component.  The
117  * netconfig entry is formatted as a struct netconfig.
118  * On each subsequent call, getnetpath returns a pointer to the netconfig
119  * entry that corresponds to the next valid NETPATH component.  getnetpath
120  * can thus be used to search the netconfig database for all networks
121  * included in the NETPATH variable.
122  * When NETPATH has been exhausted, getnetpath() returns NULL.  It returns
123  * NULL and sets errno in case of an error (e.g., setnetpath was not called
124  * previously).
125  * getnetpath() silently ignores invalid NETPATH components.  A NETPATH
126  * compnent is invalid if there is no corresponding entry in the netconfig
127  * database.
128  * If the NETPATH variable is unset, getnetpath() behaves as if NETPATH
129  * were set to the sequence of default or visible networks in the netconfig
130  * database, in the order in which they are listed.
131  */
132 
133 struct netconfig *
getnetpath(handlep)134 getnetpath(handlep)
135     void *handlep;
136 {
137     struct netpath_vars *np_sessionp = (struct netpath_vars *)handlep;
138     struct netconfig *ncp = NULL;   /* temp. holds a netconfig session */
139     struct netpath_chain *chainp;   /* holds chain of ncp's we alloc */
140     char  *npp;		/* holds current NETPATH */
141 
142     if (np_sessionp == NULL || np_sessionp->valid != NP_VALID) {
143 		errno = EINVAL;
144 		return (NULL);
145     }
146     if (np_sessionp->netpath_start == NULL) {	/* NETPATH was not set */
147 	do {                /* select next visible network */
148 	    if (np_sessionp->nc_handlep == NULL) {
149 			np_sessionp->nc_handlep = setnetconfig();
150 			if (np_sessionp->nc_handlep == NULL) {
151 				//syslog (LOG_ERR, "rpc: failed to open " NETCONFIG);
152 			}
153 	    }
154 	    if ((ncp = getnetconfig(np_sessionp->nc_handlep)) == NULL) {
155 			return(NULL);
156 	    }
157 	} while ((ncp->nc_flag & NC_VISIBLE) == 0);
158 	return (ncp);
159     }
160     /*
161      * Find first valid network ID in netpath.
162      */
163     while ((npp = np_sessionp->netpath) != NULL && strlen(npp) != 0) {
164 	np_sessionp->netpath = _get_next_token(npp, ':');
165     	/*
166     	 * npp is a network identifier.
167 	 */
168 	if ((ncp = getnetconfigent(npp)) != NULL) {
169 	    chainp = (struct netpath_chain *)	/* cobble alloc chain entry */
170 		    malloc(sizeof (struct netpath_chain));
171 	    chainp->ncp = ncp;
172 	    chainp->nchain_next = NULL;
173 	    if (np_sessionp->ncp_list == NULL) {
174 		np_sessionp->ncp_list = chainp;
175 	    } else {
176 		np_sessionp->ncp_list->nchain_next = chainp;
177 	    }
178 	    return (ncp);
179 	}
180 	/* couldn't find this token in the database; go to next one. */
181     }
182     return (NULL);
183 }
184 
185 /*
186  * endnetpath() may be called to unbind NETPATH when processing is complete,
187  * releasing resources for reuse.  It returns 0 on success and -1 on failure
188  * (e.g. if setnetpath() was not called previously.
189  */
190 int
endnetpath(handlep)191 endnetpath(handlep)
192     void *handlep;
193 {
194     struct netpath_vars *np_sessionp = (struct netpath_vars *)handlep;
195     struct netpath_chain *chainp, *lastp;
196 
197     if (np_sessionp == NULL || np_sessionp->valid != NP_VALID) {
198 	errno = EINVAL;
199 	return (-1);
200     }
201     if (np_sessionp->nc_handlep != NULL)
202 	endnetconfig(np_sessionp->nc_handlep);
203     if (np_sessionp->netpath_start != NULL)
204 	free(np_sessionp->netpath_start);
205     for (chainp = np_sessionp->ncp_list; chainp != NULL;
206 	    lastp=chainp, chainp=chainp->nchain_next, free(lastp)) {
207 	freenetconfigent(chainp->ncp);
208     }
209     free(np_sessionp);
210 #ifdef MEM_CHK
211     if (malloc_verify() == 0) {
212 	fprintf(stderr, "memory heap corrupted in endnetpath\n");
213 	exit(1);
214     }
215 #endif
216     return (0);
217 }
218 
219 
220 
221 /*
222  * Returns pointer to the rest-of-the-string after the current token.
223  * The token itself starts at arg, and we null terminate it.  We return NULL
224  * if either the arg is empty, or if this is the last token.
225  */
226 
227 char *
_get_next_token(npp,token)228 _get_next_token(npp, token)
229 char *npp;		/* string */
230 int token;		/* char to parse string for */
231 {
232     char  *cp;		/* char pointer */
233     char  *np;		/* netpath pointer */
234     char  *ep;		/* escape pointer */
235 
236     if ((cp = strchr(npp, token)) == NULL) {
237 	return (NULL);
238     }
239     /*
240      * did find a token, but it might be escaped.
241      */
242     if ((cp > npp) && (cp[-1] == '\\')) {
243         /* if slash was also escaped, carry on, otherwise find next token */
244 	if ((cp > npp + 1) && (cp[-2] != '\\')) {
245 	    /* shift r-o-s  onto the escaped token */
246 	    strcpy(&cp[-1], cp);    /* XXX: overlapping string copy */
247 	    /*
248 	     * Do a recursive call.
249 	     * We don't know how many escaped tokens there might be.
250 	     */
251 	    return (_get_next_token(cp, token));
252 	}
253     }
254 
255     *cp++ = '\0';		/* null-terminate token */
256     /* get rid of any backslash escapes */
257     ep = npp;
258     while ((np = strchr(ep, '\\')) != 0) {
259 	if (np[1] == '\\')
260 	    np++;
261 	strcpy(np, (ep = &np[1]));  /* XXX: overlapping string copy */
262     }
263     return (cp);		/* return ptr to r-o-s */
264 }
265