1 /* vi: set sw=4 ts=4: */
2 /*
3 * chattr.c - Change file attributes on an ext2 file system
4 *
5 * Copyright (C) 1993, 1994 Remy Card <card@masi.ibp.fr>
6 * Laboratoire MASI, Institut Blaise Pascal
7 * Universite Pierre et Marie Curie (Paris VI)
8 *
9 * This file can be redistributed under the terms of the GNU General
10 * Public License
11 */
12 //config:config CHATTR
13 //config: bool "chattr"
14 //config: default y
15 //config: help
16 //config: chattr changes the file attributes on a second extended file system.
17
18 //applet:IF_CHATTR(APPLET(chattr, BB_DIR_BIN, BB_SUID_DROP))
19
20 //kbuild:lib-$(CONFIG_CHATTR) += chattr.o e2fs_lib.o
21
22 //usage:#define chattr_trivial_usage
23 //usage: "[-R] [-+=AacDdijsStTu] [-v VERSION] [FILE]..."
24 //usage:#define chattr_full_usage "\n\n"
25 //usage: "Change ext2 file attributes\n"
26 //usage: "\nModifiers:"
27 //usage: "\n -,+,= Remove/add/set attributes"
28 //usage: "\nAttributes:"
29 //usage: "\n A Don't track atime"
30 //usage: "\n a Append mode only"
31 //usage: "\n c Enable compress"
32 //usage: "\n D Write dir contents synchronously"
33 //usage: "\n d Don't backup with dump"
34 //usage: "\n i Cannot be modified (immutable)"
35 //usage: "\n j Write all data to journal first"
36 //usage: "\n s Zero disk storage when deleted"
37 //usage: "\n S Write synchronously"
38 //usage: "\n t Disable tail-merging of partial blocks with other files"
39 //usage: "\n u Allow file to be undeleted"
40 //usage: "\n -R Recurse"
41 //usage: "\n -v VER Set version/generation number"
42
43 #include "libbb.h"
44 #include "e2fs_lib.h"
45
46 #define OPT_ADD 1
47 #define OPT_REM 2
48 #define OPT_SET 4
49 #define OPT_SET_VER 8
50
51 struct globals {
52 unsigned long version;
53 unsigned long af;
54 unsigned long rf;
55 smallint flags;
56 smallint recursive;
57 };
58
get_flag(char c)59 static unsigned long get_flag(char c)
60 {
61 const char *fp = strchr(e2attr_flags_sname_chattr, c);
62 if (fp)
63 return e2attr_flags_value_chattr[fp - e2attr_flags_sname_chattr];
64 bb_show_usage();
65 }
66
decode_arg(const char * arg,struct globals * gp)67 static int decode_arg(const char *arg, struct globals *gp)
68 {
69 unsigned long *fl;
70 char opt = *arg++;
71
72 fl = &gp->af;
73 if (opt == '-') {
74 gp->flags |= OPT_REM;
75 fl = &gp->rf;
76 } else if (opt == '+') {
77 gp->flags |= OPT_ADD;
78 } else if (opt == '=') {
79 gp->flags |= OPT_SET;
80 } else
81 return 0;
82
83 while (*arg)
84 *fl |= get_flag(*arg++);
85
86 return 1;
87 }
88
89 static void change_attributes(const char *name, struct globals *gp);
90
chattr_dir_proc(const char * dir_name,struct dirent * de,void * gp)91 static int FAST_FUNC chattr_dir_proc(const char *dir_name, struct dirent *de, void *gp)
92 {
93 char *path = concat_subpath_file(dir_name, de->d_name);
94 /* path is NULL if de->d_name is "." or "..", else... */
95 if (path) {
96 change_attributes(path, gp);
97 free(path);
98 }
99 return 0;
100 }
101
change_attributes(const char * name,struct globals * gp)102 static void change_attributes(const char *name, struct globals *gp)
103 {
104 unsigned long fsflags;
105 struct stat st;
106
107 if (lstat(name, &st) != 0) {
108 bb_perror_msg("stat %s", name);
109 return;
110 }
111 if (S_ISLNK(st.st_mode) && gp->recursive)
112 return;
113
114 /* Don't try to open device files, fifos etc. We probably
115 * ought to display an error if the file was explicitly given
116 * on the command line (whether or not recursive was
117 * requested). */
118 if (!S_ISREG(st.st_mode) && !S_ISLNK(st.st_mode) && !S_ISDIR(st.st_mode))
119 return;
120
121 if (gp->flags & OPT_SET_VER)
122 if (fsetversion(name, gp->version) != 0)
123 bb_perror_msg("setting version on %s", name);
124
125 if (gp->flags & OPT_SET) {
126 fsflags = gp->af;
127 } else {
128 if (fgetflags(name, &fsflags) != 0) {
129 bb_perror_msg("reading flags on %s", name);
130 goto skip_setflags;
131 }
132 /*if (gp->flags & OPT_REM) - not needed, rf is zero otherwise */
133 fsflags &= ~gp->rf;
134 /*if (gp->flags & OPT_ADD) - not needed, af is zero otherwise */
135 fsflags |= gp->af;
136 /* What is this? And why it's not done for SET case? */
137 if (!S_ISDIR(st.st_mode))
138 fsflags &= ~EXT2_DIRSYNC_FL;
139 }
140 if (fsetflags(name, fsflags) != 0)
141 bb_perror_msg("setting flags on %s", name);
142
143 skip_setflags:
144 if (gp->recursive && S_ISDIR(st.st_mode))
145 iterate_on_dir(name, chattr_dir_proc, gp);
146 }
147
148 int chattr_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
chattr_main(int argc UNUSED_PARAM,char ** argv)149 int chattr_main(int argc UNUSED_PARAM, char **argv)
150 {
151 struct globals g;
152 char *arg;
153
154 memset(&g, 0, sizeof(g));
155
156 /* parse the args */
157 while ((arg = *++argv)) {
158 /* take care of -R and -v <version> */
159 if (arg[0] == '-'
160 && (arg[1] == 'R' || arg[1] == 'v')
161 && !arg[2]
162 ) {
163 if (arg[1] == 'R') {
164 g.recursive = 1;
165 continue;
166 }
167 /* arg[1] == 'v' */
168 if (!*++argv)
169 bb_show_usage();
170 g.version = xatoul(*argv);
171 g.flags |= OPT_SET_VER;
172 continue;
173 }
174
175 if (!decode_arg(arg, &g))
176 break;
177 }
178
179 /* run sanity checks on all the arguments given us */
180 if (!*argv)
181 bb_show_usage();
182 if ((g.flags & OPT_SET) && (g.flags & (OPT_ADD|OPT_REM)))
183 bb_error_msg_and_die("= is incompatible with - and +");
184 if (g.rf & g.af)
185 bb_error_msg_and_die("can't set and unset a flag");
186 if (!g.flags)
187 bb_error_msg_and_die("must use '-v', =, - or +");
188
189 /* now run chattr on all the files passed to us */
190 do change_attributes(*argv, &g); while (*++argv);
191
192 return EXIT_SUCCESS;
193 }
194