xref: /netbsd-src/external/bsd/am-utils/dist/amd/info_union.c (revision 8bae5d409deb915cf7c8f0539fae22ff2cb8a313)
1 /*	$NetBSD: info_union.c,v 1.1.1.3 2015/01/17 16:34:15 christos Exp $	*/
2 
3 /*
4  * Copyright (c) 1997-2014 Erez Zadok
5  * Copyright (c) 1990 Jan-Simon Pendry
6  * Copyright (c) 1990 Imperial College of Science, Technology & Medicine
7  * Copyright (c) 1990 The Regents of the University of California.
8  * All rights reserved.
9  *
10  * This code is derived from software contributed to Berkeley by
11  * Jan-Simon Pendry at Imperial College, London.
12  *
13  * Redistribution and use in source and binary forms, with or without
14  * modification, are permitted provided that the following conditions
15  * are met:
16  * 1. Redistributions of source code must retain the above copyright
17  *    notice, this list of conditions and the following disclaimer.
18  * 2. Redistributions in binary form must reproduce the above copyright
19  *    notice, this list of conditions and the following disclaimer in the
20  *    documentation and/or other materials provided with the distribution.
21  * 3. Neither the name of the University nor the names of its contributors
22  *    may be used to endorse or promote products derived from this software
23  *    without specific prior written permission.
24  *
25  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
26  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
27  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
28  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
29  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
30  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
31  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
32  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
33  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
34  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
35  * SUCH DAMAGE.
36  *
37  *
38  * File: am-utils/amd/info_union.c
39  *
40  */
41 
42 /*
43  * Get info from the system namespace
44  *
45  * NOTE: Cannot handle reads back through the automounter.
46  * THIS WILL CAUSE A DEADLOCK!
47  */
48 
49 #ifdef HAVE_CONFIG_H
50 # include <config.h>
51 #endif /* HAVE_CONFIG_H */
52 #include <am_defs.h>
53 #include <amd.h>
54 
55 #define	UNION_PREFIX	"union:"
56 #define	UNION_PREFLEN	6
57 
58 /* forward declarations */
59 int union_init(mnt_map *m, char *map, time_t *tp);
60 int union_search(mnt_map *m, char *map, char *key, char **pval, time_t *tp);
61 int union_reload(mnt_map *m, char *map, void (*fn) (mnt_map *, char *, char *));
62 
63 
64 /*
65  * No way to probe - check the map name begins with "union:"
66  */
67 int
union_init(mnt_map * m,char * map,time_t * tp)68 union_init(mnt_map *m, char *map, time_t *tp)
69 {
70   *tp = 0;
71   return NSTREQ(map, UNION_PREFIX, UNION_PREFLEN) ? 0 : ENOENT;
72 }
73 
74 
75 int
union_search(mnt_map * m,char * map,char * key,char ** pval,time_t * tp)76 union_search(mnt_map *m, char *map, char *key, char **pval, time_t *tp)
77 {
78   char *mapd = xstrdup(map + UNION_PREFLEN);
79   char **v = strsplit(mapd, ':', '\"');
80   char **p;
81   size_t l;
82 
83   for (p = v; p[1]; p++) ;
84   l = strlen(*p) + 5;
85   *pval = xmalloc(l);
86   xsnprintf(*pval, l, "fs:=%s", *p);
87   XFREE(mapd);
88   XFREE(v);
89   return 0;
90 }
91 
92 
93 int
union_reload(mnt_map * m,char * map,void (* fn)(mnt_map *,char *,char *))94 union_reload(mnt_map *m, char *map, void (*fn) (mnt_map *, char *, char *))
95 {
96   static const char fseq[] = "fs:=";
97   char *mapd = xstrdup(map + UNION_PREFLEN);
98   char **v = strsplit(mapd, ':', '\"');
99   char **dir;
100 
101   /*
102    * Add fake /defaults entry
103    */
104   (*fn) (m, xstrdup("/defaults"), xstrdup("type:=link;opts:=nounmount;sublink:=${key}"));
105 
106   for (dir = v; *dir; dir++) {
107     size_t l;
108     struct dirent *dp;
109 
110     DIR *dirp = opendir(*dir);
111     if (!dirp) {
112       plog(XLOG_USER, "Cannot read directory %s: %m", *dir);
113       continue;
114     }
115     l = strlen(*dir) + sizeof(fseq);
116 
117     dlog("Reading directory %s...", *dir);
118     while ((dp = readdir(dirp))) {
119       char *val, *dpname = &dp->d_name[0];
120       if (dpname[0] == '.' &&
121 	  (dpname[1] == '\0' ||
122 	   (dpname[1] == '.' && dpname[2] == '\0')))
123 	continue;
124 
125       dlog("... gives %s", dp->d_name);
126       val = xmalloc(l);
127       xsnprintf(val, l, "%s%s", fseq, *dir);
128       (*fn) (m, xstrdup(dp->d_name), val);
129     }
130     closedir(dirp);
131   }
132 
133   /*
134    * Add wildcard entry
135    */
136   {
137     size_t l = strlen(*(dir-1)) + sizeof(fseq);
138     char *val = xmalloc(l);
139 
140     xsnprintf(val, l, "%s%s", fseq, *(dir-1));
141     (*fn) (m, xstrdup("*"), val);
142   }
143   XFREE(mapd);
144   XFREE(v);
145   return 0;
146 }
147