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
13/*
14 * History:
15 * 93/10/30	- Creation
16 * 93/11/13	- Replace stat() calls by lstat() to avoid loops
17 * 94/02/27	- Integrated in Ted's distribution
18 * 98/12/29	- Ignore symlinks when working recursively (G M Sipe)
19 * 98/12/29	- Display version info only when -V specified (G M Sipe)
20 */
21
22#include "libbb.h"
23#include "e2fs_lib.h"
24
25#define OPT_ADD 1
26#define OPT_REM 2
27#define OPT_SET 4
28#define OPT_SET_VER 8
29
30struct globals {
31	unsigned long version;
32	unsigned long af;
33	unsigned long rf;
34	smallint flags;
35	smallint recursive;
36};
37
38static unsigned long get_flag(char c)
39{
40	/* Two separate vectors take less space than vector of structs */
41	static const char flags_letter[] ALIGN1 = "ASDacdijsutT";
42	static const unsigned long flags_val[] = {
43		/* A */ EXT2_NOATIME_FL,
44		/* S */ EXT2_SYNC_FL,
45		/* D */ EXT2_DIRSYNC_FL,
46		/* a */ EXT2_APPEND_FL,
47		/* c */ EXT2_COMPR_FL,
48		/* d */ EXT2_NODUMP_FL,
49		/* i */ EXT2_IMMUTABLE_FL,
50		/* j */ EXT3_JOURNAL_DATA_FL,
51		/* s */ EXT2_SECRM_FL,
52		/* u */ EXT2_UNRM_FL,
53		/* t */ EXT2_NOTAIL_FL,
54		/* T */ EXT2_TOPDIR_FL,
55	};
56	const char *fp;
57
58	for (fp = flags_letter; *fp; fp++)
59		if (*fp == c)
60			return flags_val[fp - flags_letter];
61	bb_show_usage();
62}
63
64static int decode_arg(const char *arg, struct globals *gp)
65{
66	unsigned long *fl;
67	char opt = *arg++;
68
69	fl = &gp->af;
70	if (opt == '-') {
71		gp->flags |= OPT_REM;
72		fl = &gp->rf;
73	} else if (opt == '+') {
74		gp->flags |= OPT_ADD;
75	} else if (opt == '=') {
76		gp->flags |= OPT_SET;
77	} else
78		return 0;
79
80	while (*arg)
81		*fl |= get_flag(*arg++);
82
83	return 1;
84}
85
86static void change_attributes(const char *name, struct globals *gp);
87
88static int chattr_dir_proc(const char *dir_name, struct dirent *de, void *gp)
89{
90	char *path = concat_subpath_file(dir_name, de->d_name);
91	/* path is NULL if de->d_name is "." or "..", else... */
92	if (path) {
93		change_attributes(path, gp);
94		free(path);
95	}
96	return 0;
97}
98
99static void change_attributes(const char *name, struct globals *gp)
100{
101	unsigned long fsflags;
102	struct stat st;
103
104	if (lstat(name, &st) != 0) {
105		bb_perror_msg("stat %s", name);
106		return;
107	}
108	if (S_ISLNK(st.st_mode) && gp->recursive)
109		return;
110
111	/* Don't try to open device files, fifos etc.  We probably
112	 * ought to display an error if the file was explicitly given
113	 * on the command line (whether or not recursive was
114	 * requested).  */
115	if (!S_ISREG(st.st_mode) && !S_ISLNK(st.st_mode) && !S_ISDIR(st.st_mode))
116		return;
117
118	if (gp->flags & OPT_SET_VER)
119		if (fsetversion(name, gp->version) != 0)
120			bb_perror_msg("setting version on %s", name);
121
122	if (gp->flags & OPT_SET) {
123		fsflags = gp->af;
124	} else {
125		if (fgetflags(name, &fsflags) != 0) {
126			bb_perror_msg("reading flags on %s", name);
127			goto skip_setflags;
128		}
129		/*if (gp->flags & OPT_REM) - not needed, rf is zero otherwise */
130			fsflags &= ~gp->rf;
131		/*if (gp->flags & OPT_ADD) - not needed, af is zero otherwise */
132			fsflags |= gp->af;
133		/* What is this? And why it's not done for SET case? */
134		if (!S_ISDIR(st.st_mode))
135			fsflags &= ~EXT2_DIRSYNC_FL;
136	}
137	if (fsetflags(name, fsflags) != 0)
138		bb_perror_msg("setting flags on %s", name);
139
140 skip_setflags:
141	if (gp->recursive && S_ISDIR(st.st_mode))
142		iterate_on_dir(name, chattr_dir_proc, gp);
143}
144
145int chattr_main(int argc, char **argv);
146int chattr_main(int argc, char **argv)
147{
148	struct globals g;
149	char *arg;
150
151	memset(&g, 0, sizeof(g));
152
153	/* parse the args */
154	while ((arg = *++argv)) {
155		/* take care of -R and -v <version> */
156		if (arg[0] == '-'
157		 && (arg[1] == 'R' || arg[1] == 'v')
158		 && !arg[2]
159		) {
160			if (arg[1] == 'R') {
161				g.recursive = 1;
162				continue;
163			}
164			/* arg[1] == 'v' */
165			if (!*++argv)
166				bb_show_usage();
167			g.version = xatoul(*argv);
168			g.flags |= OPT_SET_VER;
169			continue;
170		}
171
172		if (!decode_arg(arg, &g))
173			break;
174	}
175
176	/* run sanity checks on all the arguments given us */
177	if (!*argv)
178		bb_show_usage();
179	if ((g.flags & OPT_SET) && (g.flags & (OPT_ADD|OPT_REM)))
180		bb_error_msg_and_die("= is incompatible with - and +");
181	if (g.rf & g.af)
182		bb_error_msg_and_die("can't set and unset a flag");
183	if (!g.flags)
184		bb_error_msg_and_die("must use '-v', =, - or +");
185
186	/* now run chattr on all the files passed to us */
187	do change_attributes(*argv, &g); while (*++argv);
188
189	return EXIT_SUCCESS;
190}
191