scoutos / prex-0.9.0 / usr / server / fs / vfs / vfs_lookup.c @ 03e9c04a
History | View | Annotate | Download (4.34 KB)
1 |
/*
|
---|---|
2 |
* Copyright (c) 2005-2007, Kohsuke Ohtani
|
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
|
7 |
* are met:
|
8 |
* 1. Redistributions of source code must retain the above copyright
|
9 |
* notice, this list of conditions and the following disclaimer.
|
10 |
* 2. Redistributions in binary form must reproduce the above copyright
|
11 |
* notice, this list of conditions and the following disclaimer in the
|
12 |
* documentation and/or other materials provided with the distribution.
|
13 |
* 3. Neither the name of the author nor the names of any co-contributors
|
14 |
* may be used to endorse or promote products derived from this software
|
15 |
* without specific prior written permission.
|
16 |
*
|
17 |
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
|
18 |
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
|
19 |
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
|
20 |
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
|
21 |
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
|
22 |
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
|
23 |
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
|
24 |
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
|
25 |
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
|
26 |
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
|
27 |
* SUCH DAMAGE.
|
28 |
*/
|
29 |
|
30 |
/*
|
31 |
* vfs_lookup.c - vnode lookup function.
|
32 |
*/
|
33 |
|
34 |
#include <sys/vnode.h> |
35 |
#include <sys/mount.h> |
36 |
|
37 |
#include <limits.h> |
38 |
#include <unistd.h> |
39 |
#include <string.h> |
40 |
#include <errno.h> |
41 |
|
42 |
#include "vfs.h" |
43 |
|
44 |
/*
|
45 |
* Convert a pathname into a pointer to a locked vnode.
|
46 |
*
|
47 |
* @path: full path name.
|
48 |
* @vpp: vnode to be returned.
|
49 |
*/
|
50 |
int
|
51 |
namei(char *path, vnode_t *vpp)
|
52 |
{ |
53 |
char *p;
|
54 |
char node[PATH_MAX];
|
55 |
char name[PATH_MAX];
|
56 |
mount_t mp; |
57 |
vnode_t dvp, vp; |
58 |
int error, i;
|
59 |
|
60 |
DPRINTF(VFSDB_VNODE, ("namei: path=%s\n", path));
|
61 |
|
62 |
/*
|
63 |
* Convert a full path name to its mount point and
|
64 |
* the local node in the file system.
|
65 |
*/
|
66 |
if (vfs_findroot(path, &mp, &p))
|
67 |
return ENOTDIR;
|
68 |
strlcpy(node, "/", sizeof(node)); |
69 |
strlcat(node, p, sizeof(node));
|
70 |
vp = vn_lookup(mp, node); |
71 |
if (vp) {
|
72 |
/* vnode is already active. */
|
73 |
*vpp = vp; |
74 |
return 0; |
75 |
} |
76 |
/*
|
77 |
* Find target vnode, started from root directory.
|
78 |
* This is done to attach the fs specific data to
|
79 |
* the target vnode.
|
80 |
*/
|
81 |
if ((dvp = mp->m_root) == NULL) |
82 |
sys_panic("VFS: no root");
|
83 |
|
84 |
vref(dvp); |
85 |
vn_lock(dvp); |
86 |
node[0] = '\0'; |
87 |
|
88 |
while (*p != '\0') { |
89 |
/*
|
90 |
* Get lower directory/file name.
|
91 |
*/
|
92 |
while (*p == '/') |
93 |
p++; |
94 |
for (i = 0; i < PATH_MAX; i++) { |
95 |
if (*p == '\0' || *p == '/') |
96 |
break;
|
97 |
name[i] = *p++; |
98 |
} |
99 |
name[i] = '\0';
|
100 |
|
101 |
/*
|
102 |
* Get a vnode for the target.
|
103 |
*/
|
104 |
strlcat(node, "/", sizeof(node)); |
105 |
strlcat(node, name, sizeof(node));
|
106 |
vp = vn_lookup(mp, node); |
107 |
if (vp == NULL) { |
108 |
vp = vget(mp, node); |
109 |
if (vp == NULL) { |
110 |
vput(dvp); |
111 |
return ENOMEM;
|
112 |
} |
113 |
/* Find a vnode in this directory. */
|
114 |
error = VOP_LOOKUP(dvp, name, vp); |
115 |
if (error || (*p == '/' && vp->v_type != VDIR)) { |
116 |
/* Not found */
|
117 |
vput(vp); |
118 |
vput(dvp); |
119 |
return error;
|
120 |
} |
121 |
} |
122 |
vput(dvp); |
123 |
dvp = vp; |
124 |
while (*p != '\0' && *p != '/') |
125 |
p++; |
126 |
} |
127 |
|
128 |
/*
|
129 |
* Detemine X permission.
|
130 |
*/
|
131 |
if (vp->v_type != VDIR && sec_vnode_permission(path) != 0) { |
132 |
vp->v_mode &= ~(0111);
|
133 |
} |
134 |
|
135 |
*vpp = vp; |
136 |
return 0; |
137 |
} |
138 |
|
139 |
/*
|
140 |
* Search a pathname.
|
141 |
* This is a very central but not so complicated routine. ;-P
|
142 |
*
|
143 |
* @path: full path.
|
144 |
* @vpp: pointer to locked vnode for directory.
|
145 |
* @name: pointer to file name in path.
|
146 |
*
|
147 |
* This routine returns a locked directory vnode and file name.
|
148 |
*/
|
149 |
int
|
150 |
lookup(char *path, vnode_t *vpp, char **name) |
151 |
{ |
152 |
char buf[PATH_MAX];
|
153 |
char root[] = "/"; |
154 |
char *file, *dir;
|
155 |
vnode_t vp; |
156 |
int error;
|
157 |
|
158 |
DPRINTF(VFSDB_VNODE, ("lookup: path=%s\n", path));
|
159 |
|
160 |
/*
|
161 |
* Get the path for directory.
|
162 |
*/
|
163 |
strlcpy(buf, path, sizeof(buf));
|
164 |
file = strrchr(buf, '/');
|
165 |
if (!buf[0]) |
166 |
return ENOTDIR;
|
167 |
if (file == buf)
|
168 |
dir = root; |
169 |
else {
|
170 |
*file = '\0';
|
171 |
dir = buf; |
172 |
} |
173 |
/*
|
174 |
* Get the vnode for directory
|
175 |
*/
|
176 |
if ((error = namei(dir, &vp)) != 0) |
177 |
return error;
|
178 |
if (vp->v_type != VDIR) {
|
179 |
vput(vp); |
180 |
return ENOTDIR;
|
181 |
} |
182 |
*vpp = vp; |
183 |
|
184 |
/*
|
185 |
* Get the file name
|
186 |
*/
|
187 |
*name = strrchr(path, '/') + 1; |
188 |
return 0; |
189 |
} |