1 /*
2 * Unsquash a squashfs filesystem. This is a highly compressed read only
3 * filesystem.
4 *
5 * Copyright (c) 2010, 2012
6 * Phillip Lougher <phillip@squashfs.org.uk>
7 *
8 * This program is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU General Public License
10 * as published by the Free Software Foundation; either version 2,
11 * or (at your option) any later version.
12 *
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
17 *
18 * You should have received a copy of the GNU General Public License
19 * along with this program; if not, write to the Free Software
20 * Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
21 *
22 * unsquashfs_xattr.c
23 */
24
25 #include "unsquashfs.h"
26 #include "xattr.h"
27
28 #include <sys/xattr.h>
29
30 #define NOSPACE_MAX 10
31
32 extern int root_process;
33 extern int user_xattrs;
34
write_xattr(char * pathname,unsigned int xattr)35 void write_xattr(char *pathname, unsigned int xattr)
36 {
37 unsigned int count;
38 struct xattr_list *xattr_list;
39 int i;
40 static int nonsuper_error = FALSE;
41 static int ignore_xattrs = FALSE;
42 static int nospace_error = 0;
43
44 if(ignore_xattrs || xattr == SQUASHFS_INVALID_XATTR ||
45 sBlk.s.xattr_id_table_start == SQUASHFS_INVALID_BLK)
46 return;
47
48 xattr_list = get_xattr(xattr, &count, 1);
49 if(xattr_list == NULL) {
50 ERROR("Failed to read xattrs for file %s\n", pathname);
51 return;
52 }
53
54 for(i = 0; i < count; i++) {
55 int prefix = xattr_list[i].type & SQUASHFS_XATTR_PREFIX_MASK;
56
57 if(user_xattrs && prefix != SQUASHFS_XATTR_USER)
58 continue;
59
60 if(root_process || prefix == SQUASHFS_XATTR_USER) {
61 int res = lsetxattr(pathname, xattr_list[i].full_name,
62 xattr_list[i].value, xattr_list[i].vsize, 0);
63
64 if(res == -1) {
65 if(errno == ENOTSUP) {
66 /*
67 * If the destination filesystem cannot
68 * suppport xattrs, print error, and
69 * disable xattr output as this error is
70 * unlikely to go away, and printing
71 * screenfulls of the same error message
72 * is rather annoying
73 */
74 ERROR("write_xattr: failed to write "
75 "xattr %s for file %s because "
76 "extended attributes are not "
77 "supported by the destination "
78 "filesystem\n",
79 xattr_list[i].full_name,
80 pathname);
81 ERROR("Ignoring xattrs in "
82 "filesystem\n");
83 ERROR("To avoid this error message, "
84 "specify -no-xattrs\n");
85 ignore_xattrs = TRUE;
86 } else if((errno == ENOSPC || errno == EDQUOT)
87 && nospace_error < NOSPACE_MAX) {
88 /*
89 * Many filesystems like ext2/3/4 have
90 * limits on the amount of xattr
91 * data that can be stored per file
92 * (typically one block or 4K), so
93 * we shouldn't disable xattr ouput,
94 * as the error may be restriced to one
95 * file only. If we get a lot of these
96 * then suppress the error messsage
97 */
98 ERROR("write_xattr: failed to write "
99 "xattr %s for file %s because "
100 "no extended attribute space "
101 "remaining (per file or "
102 "filesystem limit)\n",
103 xattr_list[i].full_name,
104 pathname);
105 if(++ nospace_error == NOSPACE_MAX)
106 ERROR("%d of these errors "
107 "printed, further error "
108 "messages of this type "
109 "are suppressed!\n",
110 NOSPACE_MAX);
111 } else
112 ERROR("write_xattr: failed to write "
113 "xattr %s for file %s because "
114 "%s\n", xattr_list[i].full_name,
115 pathname, strerror(errno));
116 }
117 } else if(nonsuper_error == FALSE) {
118 /*
119 * if extract user xattrs only then
120 * error message is suppressed, if not
121 * print error, and then suppress further error
122 * messages to avoid possible screenfulls of the
123 * same error message!
124 */
125 ERROR("write_xattr: could not write xattr %s "
126 "for file %s because you're not "
127 "superuser!\n",
128 xattr_list[i].full_name, pathname);
129 ERROR("write_xattr: to avoid this error message, either"
130 " specify -user-xattrs, -no-xattrs, or run as "
131 "superuser!\n");
132 ERROR("Further error messages of this type are "
133 "suppressed!\n");
134 nonsuper_error = TRUE;
135 }
136 }
137
138 free_xattr(xattr_list, count);
139 }
140