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 (3.8 kb)"
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_NOEXEC(chattr, chattr, BB_DIR_BIN, BB_SUID_DROP, chattr))
19
20 //kbuild:lib-$(CONFIG_CHATTR) += chattr.o e2fs_lib.o
21
22 //usage:#define chattr_trivial_usage
23 //usage: "[-R] [-v VERSION] [-p PROJID] [-+=AacDdijsStTu] FILE..."
24 //usage:#define chattr_full_usage "\n\n"
25 //usage: "Change ext2 file attributes\n"
26 //usage: "\n -R Recurse"
27 //usage: "\n -v NUM Set version/generation number"
28 //usage: "\n -p NUM Set project number"
29 //-V, -f accepted but ignored
30 //usage: "\nModifiers:"
31 //usage: "\n -,+,= Remove/add/set attributes"
32 //usage: "\nAttributes:"
33 //usage: "\n A No atime"
34 //usage: "\n a Append only"
35 //usage: "\n C No copy-on-write"
36 //usage: "\n c Compressed"
37 //usage: "\n D Synchronous dir updates"
38 //usage: "\n d Don't backup with dump"
39 //usage: "\n E Encrypted"
40 //usage: "\n e File uses extents"
41 //usage: "\n F Case-insensitive dir"
42 //usage: "\n I Indexed dir"
43 //usage: "\n i Immutable"
44 //usage: "\n j Write data to journal first"
45 //usage: "\n N File is stored in inode"
46 //usage: "\n P Hierarchical project ID dir"
47 //usage: "\n S Synchronous file updates"
48 //usage: "\n s Zero storage when deleted"
49 //usage: "\n T Top of dir hierarchy"
50 //usage: "\n t Don't tail-merge with other files"
51 //usage: "\n u Allow undelete"
52 //usage: "\n V Verity"
53
54 #include "libbb.h"
55 #include "e2fs_lib.h"
56
57 #define OPT_ADD (1 << 0)
58 #define OPT_REM (1 << 1)
59 #define OPT_SET (1 << 2)
60 #define OPT_SET_VER (1 << 3)
61 #define OPT_SET_PROJ (1 << 4)
62
63 struct globals {
64 unsigned version;
65 unsigned af;
66 unsigned rf;
67 int flags;
68 uint32_t projid;
69 smallint recursive;
70 };
71
get_flag(char c)72 static unsigned long get_flag(char c)
73 {
74 const char *fp = strchr(e2attr_flags_sname_chattr, c);
75 if (fp)
76 return e2attr_flags_value_chattr[fp - e2attr_flags_sname_chattr];
77 bb_show_usage();
78 }
79
decode_arg(char ** argv,struct globals * gp)80 static char** decode_arg(char **argv, struct globals *gp)
81 {
82 unsigned *fl;
83 const char *arg = *argv;
84 char opt = *arg;
85
86 fl = &gp->af;
87 if (opt == '-') {
88 /* gp->flags |= OPT_REM; - WRONG, it can be an option */
89 /* testcase: chattr =ae -R FILE should not complain "= is incompatible with - and +" */
90 /* (and should not read flags, with =FLAGS they can be just set directly) */
91 fl = &gp->rf;
92 } else if (opt == '+') {
93 gp->flags |= OPT_ADD;
94 } else { /* if (opt == '=') */
95 gp->flags |= OPT_SET;
96 }
97
98 while (*++arg) {
99 if (opt == '-') {
100 //e2fsprogs-1.43.1 accepts:
101 // "-RRR", "-RRRv VER" and even "-ARRRva VER" and "-vvv V1 V2 V3"
102 // but not "-vVER".
103 // IOW: options are parsed as part of "remove attrs" strings,
104 // if "v" is seen, next argv[] is VER, even if more opts/attrs follow in this argv[]!
105 if (*arg == 'R') {
106 gp->recursive = 1;
107 continue;
108 }
109 if (*arg == 'V') {
110 /*"verbose and print program version" (nop for now) */;
111 continue;
112 }
113 if (*arg == 'f') {
114 /*"suppress most error messages" (nop) */;
115 continue;
116 }
117 if (*arg == 'v') {
118 if (!*++argv)
119 bb_show_usage();
120 gp->version = xatou(*argv);
121 gp->flags |= OPT_SET_VER;
122 continue;
123 }
124 if (*arg == 'p') {
125 if (!*++argv)
126 bb_show_usage();
127 gp->projid = xatou32(*argv);
128 gp->flags |= OPT_SET_PROJ;
129 continue;
130 }
131 /* not a known option, try as an attribute */
132 gp->flags |= OPT_REM;
133 }
134 *fl |= get_flag(*arg); /* aborts on bad flag letter */
135 }
136
137 return argv;
138 }
139
140 static void change_attributes(const char *name, struct globals *gp);
141
chattr_dir_proc(const char * dir_name,struct dirent * de,void * gp)142 static int FAST_FUNC chattr_dir_proc(const char *dir_name, struct dirent *de, void *gp)
143 {
144 //TODO: use de->d_type (if it's not DT_UNKNOWN) to skip !(REG || DIR || LNK) entries without lstat?
145
146 char *path = concat_subpath_file(dir_name, de->d_name);
147 /* path is NULL if de->d_name is "." or "..", else... */
148 if (path) {
149 change_attributes(path, gp);
150 free(path);
151 }
152 return 0;
153 }
154
change_attributes(const char * name,struct globals * gp)155 static void change_attributes(const char *name, struct globals *gp)
156 {
157 unsigned fsflags;
158 int fd;
159 struct stat st;
160
161 if (lstat(name, &st) != 0) {
162 bb_perror_msg("can't stat '%s'", name);
163 return;
164 }
165
166 /* Don't try to open device files, fifos etc. We probably
167 * ought to display an error if the file was explicitly given
168 * on the command line (whether or not recursive was
169 * requested). */
170 if (!S_ISREG(st.st_mode) && !S_ISLNK(st.st_mode) && !S_ISDIR(st.st_mode))
171 return;
172
173 /* There is no way to run needed ioctls on a symlink.
174 * open(O_PATH | O_NOFOLLOW) _can_ be used to get a fd referring to the symlink,
175 * but ioctls fail on such a fd (tried on 4.12.0 kernel).
176 * e2fsprogs-1.46.2 uses open(O_NOFOLLOW), it fails on symlinks.
177 */
178 fd = open_or_warn(name, O_RDONLY | O_NONBLOCK | O_NOCTTY | O_NOFOLLOW);
179 if (fd >= 0) {
180 int r;
181
182 if (gp->flags & OPT_SET_VER) {
183 r = ioctl(fd, EXT2_IOC_SETVERSION, &gp->version);
184 if (r != 0)
185 bb_perror_msg("setting %s on %s", "version", name);
186 }
187
188 if (gp->flags & OPT_SET_PROJ) {
189 struct ext2_fsxattr fsxattr;
190 r = ioctl(fd, EXT2_IOC_FSGETXATTR, &fsxattr);
191 /* note: ^^^ may fail in 32-bit userspace on 64-bit kernel (seen on 4.12.0) */
192 if (r != 0) {
193 bb_perror_msg("getting %s on %s", "project ID", name);
194 } else {
195 fsxattr.fsx_projid = gp->projid;
196 r = ioctl(fd, EXT2_IOC_FSSETXATTR, &fsxattr);
197 if (r != 0)
198 bb_perror_msg("setting %s on %s", "project ID", name);
199 }
200 }
201
202 if (gp->flags & OPT_SET) {
203 fsflags = gp->af;
204 } else {
205 r = ioctl(fd, EXT2_IOC_GETFLAGS, &fsflags);
206 if (r != 0) {
207 bb_perror_msg("getting %s on %s", "flags", name);
208 goto skip_setflags;
209 }
210 /*if (gp->flags & OPT_REM) - not needed, rf is zero otherwise */
211 fsflags &= ~gp->rf;
212 /*if (gp->flags & OPT_ADD) - not needed, af is zero otherwise */
213 fsflags |= gp->af;
214 // What is this? And why it's not done for SET case?
215 if (!S_ISDIR(st.st_mode))
216 fsflags &= ~EXT2_DIRSYNC_FL;
217 }
218 r = ioctl(fd, EXT2_IOC_SETFLAGS, &fsflags);
219 if (r != 0)
220 bb_perror_msg("setting %s on %s", "flags", name);
221 skip_setflags:
222 close(fd);
223 }
224
225 if (gp->recursive && S_ISDIR(st.st_mode))
226 iterate_on_dir(name, chattr_dir_proc, gp);
227 }
228
229 int chattr_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
chattr_main(int argc UNUSED_PARAM,char ** argv)230 int chattr_main(int argc UNUSED_PARAM, char **argv)
231 {
232 struct globals g;
233
234 memset(&g, 0, sizeof(g));
235
236 /* parse the args */
237 for (;;) {
238 char *arg = *++argv;
239 if (!arg)
240 bb_show_usage();
241 if (arg[0] != '-' && arg[0] != '+' && arg[0] != '=')
242 break;
243
244 argv = decode_arg(argv, &g);
245 }
246 /* note: on loop exit, remaining argv[] is never empty */
247
248 /* run sanity checks on all the arguments given us */
249 if ((g.flags & OPT_SET) && (g.flags & (OPT_ADD|OPT_REM)))
250 bb_simple_error_msg_and_die("= is incompatible with - and +");
251 if (g.rf & g.af)
252 bb_simple_error_msg_and_die("can't set and unset a flag");
253 if (!g.flags)
254 bb_simple_error_msg_and_die("must use -v, -p, =, - or +");
255
256 /* now run chattr on all the files passed to us */
257 do change_attributes(*argv, &g); while (*++argv);
258
259 return EXIT_SUCCESS;
260 }
261