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 #ifdef XATTR_NOFOLLOW /* Apple's xattrs */
31 #define lsetxattr(path_, name_, val_, sz_, flags_) \
32 setxattr(path_, name_, val_, sz_, 0, flags_ | XATTR_NOFOLLOW)
33 #endif
34
35 #define NOSPACE_MAX 10
36
37 extern int root_process;
38 extern int user_xattrs;
39
write_xattr(char * pathname,unsigned int xattr)40 void write_xattr(char *pathname, unsigned int xattr)
41 {
42 unsigned int count;
43 struct xattr_list *xattr_list;
44 int i;
45 static int nonsuper_error = FALSE;
46 static int ignore_xattrs = FALSE;
47 static int nospace_error = 0;
48
49 if(ignore_xattrs || xattr == SQUASHFS_INVALID_XATTR ||
50 sBlk.s.xattr_id_table_start == SQUASHFS_INVALID_BLK)
51 return;
52
53 xattr_list = get_xattr(xattr, &count, 1);
54 if(xattr_list == NULL) {
55 ERROR("Failed to read xattrs for file %s\n", pathname);
56 return;
57 }
58
59 for(i = 0; i < count; i++) {
60 int prefix = xattr_list[i].type & SQUASHFS_XATTR_PREFIX_MASK;
61
62 if(user_xattrs && prefix != SQUASHFS_XATTR_USER)
63 continue;
64
65 if(root_process || prefix == SQUASHFS_XATTR_USER) {
66 int res = lsetxattr(pathname, xattr_list[i].full_name,
67 xattr_list[i].value, xattr_list[i].vsize, 0);
68
69 if(res == -1) {
70 if(errno == ENOTSUP) {
71 /*
72 * If the destination filesystem cannot
73 * suppport xattrs, print error, and
74 * disable xattr output as this error is
75 * unlikely to go away, and printing
76 * screenfulls of the same error message
77 * is rather annoying
78 */
79 ERROR("write_xattr: failed to write "
80 "xattr %s for file %s because "
81 "extended attributes are not "
82 "supported by the destination "
83 "filesystem\n",
84 xattr_list[i].full_name,
85 pathname);
86 ERROR("Ignoring xattrs in "
87 "filesystem\n");
88 ERROR("To avoid this error message, "
89 "specify -no-xattrs\n");
90 ignore_xattrs = TRUE;
91 } else if((errno == ENOSPC || errno == EDQUOT)
92 && nospace_error < NOSPACE_MAX) {
93 /*
94 * Many filesystems like ext2/3/4 have
95 * limits on the amount of xattr
96 * data that can be stored per file
97 * (typically one block or 4K), so
98 * we shouldn't disable xattr ouput,
99 * as the error may be restriced to one
100 * file only. If we get a lot of these
101 * then suppress the error messsage
102 */
103 ERROR("write_xattr: failed to write "
104 "xattr %s for file %s because "
105 "no extended attribute space "
106 "remaining (per file or "
107 "filesystem limit)\n",
108 xattr_list[i].full_name,
109 pathname);
110 if(++ nospace_error == NOSPACE_MAX)
111 ERROR("%d of these errors "
112 "printed, further error "
113 "messages of this type "
114 "are suppressed!\n",
115 NOSPACE_MAX);
116 } else
117 ERROR("write_xattr: failed to write "
118 "xattr %s for file %s because "
119 "%s\n", xattr_list[i].full_name,
120 pathname, strerror(errno));
121 }
122 } else if(nonsuper_error == FALSE) {
123 /*
124 * if extract user xattrs only then
125 * error message is suppressed, if not
126 * print error, and then suppress further error
127 * messages to avoid possible screenfulls of the
128 * same error message!
129 */
130 ERROR("write_xattr: could not write xattr %s "
131 "for file %s because you're not "
132 "superuser!\n",
133 xattr_list[i].full_name, pathname);
134 ERROR("write_xattr: to avoid this error message, either"
135 " specify -user-xattrs, -no-xattrs, or run as "
136 "superuser!\n");
137 ERROR("Further error messages of this type are "
138 "suppressed!\n");
139 nonsuper_error = TRUE;
140 }
141 }
142
143 free_xattr(xattr_list, count);
144 }
145