1 /*	$NetBSD: getusershell.c,v 1.1.1.1 2011/04/13 18:15:41 elric Exp $	*/
2 
3 /*
4  * Copyright (c) 1985, 1993
5  *	The Regents of the University of California.  All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. Neither the name of the University nor the names of its contributors
16  *    may be used to endorse or promote products derived from this software
17  *    without specific prior written permission.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29  * SUCH DAMAGE.
30  */
31 
32 #include <config.h>
33 
34 #ifndef HAVE_GETUSERSHELL
35 
36 #include <stdio.h>
37 #include <stdlib.h>
38 #include <string.h>
39 #include <ctype.h>
40 #ifdef HAVE_PATHS_H
41 #include <paths.h>
42 #endif
43 #ifdef HAVE_SYS_TYPES_H
44 #include <sys/types.h>
45 #endif
46 #ifdef HAVE_SYS_STAT_H
47 #include <sys/stat.h>
48 #endif
49 #ifdef HAVE_SYS_PARAM_H
50 #include <sys/param.h>
51 #endif
52 
53 #ifdef HAVE_USERSEC_H
54 struct aud_rec;
55 #include <usersec.h>
56 #endif
57 #ifdef HAVE_USERCONF_H
58 #include <userconf.h>
59 #endif
60 #include <krb5/roken.h>
61 
62 #ifndef _PATH_SHELLS
63 #define _PATH_SHELLS "/etc/shells"
64 #endif
65 
66 #ifndef _PATH_BSHELL
67 #define _PATH_BSHELL "/bin/sh"
68 #endif
69 
70 #ifndef _PATH_CSHELL
71 #define _PATH_CSHELL "/bin/csh"
72 #endif
73 
74 /*
75  * Local shells should NOT be added here.  They should be added in
76  * /etc/shells.
77  */
78 
79 static char *okshells[] = { _PATH_BSHELL, _PATH_CSHELL, NULL };
80 static char **curshell, **shells, *strings;
81 static char **initshells (void);
82 
83 /*
84  * Get a list of shells from _PATH_SHELLS, if it exists.
85  */
86 ROKEN_LIB_FUNCTION char * ROKEN_LIB_CALL
87 getusershell()
88 {
89     char *ret;
90 
91     if (curshell == NULL)
92 	curshell = initshells();
93     ret = *curshell;
94     if (ret != NULL)
95 	curshell++;
96     return (ret);
97 }
98 
99 ROKEN_LIB_FUNCTION void ROKEN_LIB_CALL
100 endusershell()
101 {
102     if (shells != NULL)
103 	free(shells);
104     shells = NULL;
105     if (strings != NULL)
106 	free(strings);
107     strings = NULL;
108     curshell = NULL;
109 }
110 
111 ROKEN_LIB_FUNCTION void ROKEN_LIB_CALL
112 setusershell()
113 {
114     curshell = initshells();
115 }
116 
117 static char **
118 initshells()
119 {
120     char **sp, *cp;
121 #ifdef HAVE_GETCONFATTR
122     char *tmp;
123     int nsh;
124 #else
125     FILE *fp;
126 #endif
127     struct stat statb;
128 
129     free(shells);
130     shells = NULL;
131     free(strings);
132     strings = NULL;
133 #ifdef HAVE_GETCONFATTR
134     if(getconfattr(SC_SYS_LOGIN, SC_SHELLS, &tmp, SEC_LIST) != 0)
135 	return okshells;
136 
137     for(cp = tmp, nsh = 0; *cp; cp += strlen(cp) + 1, nsh++);
138 
139     shells = calloc(nsh + 1, sizeof(*shells));
140     if(shells == NULL)
141 	return okshells;
142 
143     strings = malloc(cp - tmp);
144     if(strings == NULL) {
145 	free(shells);
146 	shells = NULL;
147 	return okshells;
148     }
149     memcpy(strings, tmp, cp - tmp);
150     for(sp = shells, cp = strings; *cp; cp += strlen(cp) + 1, sp++)
151 	*sp = cp;
152 #else
153     if ((fp = fopen(_PATH_SHELLS, "r")) == NULL)
154 	return (okshells);
155     if (fstat(fileno(fp), &statb) == -1) {
156 	fclose(fp);
157 	return (okshells);
158     }
159     if ((strings = malloc((u_int)statb.st_size)) == NULL) {
160 	fclose(fp);
161 	return (okshells);
162     }
163     shells = calloc((unsigned)statb.st_size / 3, sizeof (char *));
164     if (shells == NULL) {
165 	fclose(fp);
166 	free(strings);
167 	strings = NULL;
168 	return (okshells);
169     }
170     sp = shells;
171     cp = strings;
172     while (fgets(cp, MaxPathLen + 1, fp) != NULL) {
173 	while (*cp != '#' && *cp != '/' && *cp != '\0')
174 	    cp++;
175 	if (*cp == '#' || *cp == '\0')
176 	    continue;
177 	*sp++ = cp;
178 	while (!isspace((unsigned char)*cp) && *cp != '#' && *cp != '\0')
179 	    cp++;
180 	*cp++ = '\0';
181     }
182     fclose(fp);
183 #endif
184     *sp = NULL;
185     return (shells);
186 }
187 #endif /* HAVE_GETUSERSHELL */
188