summaryrefslogtreecommitdiffhomepage
path: root/modutils/modinfo.c
blob: 6eae1b7b15feb89ed7a3fb85a570833e842499a5 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
/* vi: set sw=4 ts=4: */
/*
 * modinfo - retrieve module info
 * Copyright (c) 2008 Pascal Bellard
 *
 * Licensed under GPLv2 or later, see file LICENSE in this source tree.
 */
//config:config MODINFO
//config:	bool "modinfo (25 kb)"
//config:	default y
//config:	select PLATFORM_LINUX
//config:	help
//config:	  Show information about a Linux Kernel module

//applet:IF_MODINFO(APPLET(modinfo, BB_DIR_SBIN, BB_SUID_DROP))

//kbuild:lib-$(CONFIG_MODINFO) += modinfo.o modutils.o

#include <fnmatch.h>
#include <sys/utsname.h> /* uname() */
#include "libbb.h"
#include "modutils.h"

static const char *const shortcuts[] = {
	"filename",	// -n
	"author",	// -a
	"description",	// -d
	"license",	// -l
	"parm",		// -p
	"version",	// the rest has no shortcut options
	"alias",
	"srcversion",
	"depends",
	"uts_release",
	"intree",
	"vermagic",
	"firmware",
};

enum {
	OPT_0 = (1 << 0), /* \0 as separator */
	OPT_F = (1 << 1), /* field name */
	/* first bits are for -nadlp options, the rest are for
	 * fields not selectable with "shortcut" options
	 */
	OPT_n = (1 << 2),
	OPT_TAGS = ((1 << ARRAY_SIZE(shortcuts)) - 1) << 2,
};

static void display(const char *data, const char *pattern)
{
	int flag = option_mask32 >> 1; /* shift out -0 bit */
	if (flag & (flag-1)) {
		/* more than one field to show: print "FIELD:" pfx */
		int n = printf("%s:", pattern);
		while (n++ < 16)
			bb_putchar(' ');
	}
	printf("%s%c", data, (option_mask32 & OPT_0) ? '\0' : '\n');
}

static void modinfo(const char *path, const char *version,
			const char *field)
{
	size_t len;
	int j;
	char *ptr, *the_module;
	char *allocated;
	int tags = option_mask32;

	allocated = NULL;
	len = MAXINT(ssize_t);
	the_module = xmalloc_open_zipped_read_close(path, &len);
	if (!the_module) {
		if (path[0] == '/')
			return;
		/* Newer depmod puts relative paths in modules.dep */
		path = allocated = xasprintf("%s/%s/%s", CONFIG_DEFAULT_MODULES_DIR, version, path);
		the_module = xmalloc_open_zipped_read_close(path, &len);
		if (!the_module) {
			bb_error_msg("module '%s' not found", path);
			goto ret;
		}
	}

	for (j = 1; (1<<j) & (OPT_TAGS|OPT_F); j++) {
		const char *pattern;

		if (!((1<<j) & tags))
			continue;

		pattern = field;
		if ((1<<j) & OPT_TAGS)
			pattern = shortcuts[j-2];

		if (strcmp(pattern, shortcuts[0]) == 0) {
			/* "-n" or "-F filename" */
			display(path, shortcuts[0]);
			continue;
		}

		ptr = the_module;
		while (1) {
			char *after_pattern;

			ptr = memchr(ptr, *pattern, len - (ptr - (char*)the_module));
			if (ptr == NULL) /* no occurrence left, done */
				break;
			after_pattern = is_prefixed_with(ptr, pattern);
			if (after_pattern && *after_pattern == '=') {
				/* field prefixes are 0x80 or 0x00 */
				if ((ptr[-1] & 0x7F) == 0x00) {
					ptr = after_pattern + 1;
					display(ptr, pattern);
					ptr += strlen(ptr);
				}
			}
			++ptr;
		}
	}
	free(the_module);
 ret:
	free(allocated);
}

//usage:#define modinfo_trivial_usage
//usage:       "[-adlpn0] [-F keyword] MODULE"
//usage:#define modinfo_full_usage "\n\n"
//usage:       "	-a		Shortcut for '-F author'"
//usage:     "\n	-d		Shortcut for '-F description'"
//usage:     "\n	-l		Shortcut for '-F license'"
//usage:     "\n	-p		Shortcut for '-F parm'"
////usage:     "\n	-n		Shortcut for '-F filename'"
//usage:     "\n	-F keyword	Keyword to look for"
//usage:     "\n	-0		Separate output with NULs"
//usage:#define modinfo_example_usage
//usage:       "$ modinfo -F vermagic loop\n"

int modinfo_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int modinfo_main(int argc UNUSED_PARAM, char **argv)
{
	const char *field;
	char name[MODULE_NAME_LEN];
	struct utsname uts;
	parser_t *parser;
	char *colon, *tokens[2];
	unsigned opts;
	unsigned i;

	field = NULL;
	opt_complementary = "-1"; /* minimum one param */
	opts = getopt32(argv, "0F:nadlp", &field);
	/* If no field selected, show all */
	if (!(opts & (OPT_TAGS|OPT_F)))
		option_mask32 |= OPT_TAGS;
	argv += optind;

	uname(&uts);
	parser = config_open2(
		xasprintf("%s/%s/%s", CONFIG_DEFAULT_MODULES_DIR, uts.release, CONFIG_DEFAULT_DEPMOD_FILE),
		xfopen_for_read
	);

	while (config_read(parser, tokens, 2, 1, "# \t", PARSE_NORMAL)) {
		colon = last_char_is(tokens[0], ':');
		if (colon == NULL)
			continue;
		*colon = '\0';
		filename2modname(bb_basename(tokens[0]), name);
		for (i = 0; argv[i]; i++) {
			if (fnmatch(argv[i], name, 0) == 0) {
				modinfo(tokens[0], uts.release, field);
				argv[i] = (char *) "";
			}
		}
	}
	if (ENABLE_FEATURE_CLEAN_UP)
		config_close(parser);

	for (i = 0; argv[i]; i++) {
		if (argv[i][0]) {
			modinfo(argv[i], uts.release, field);
		}
	}

	return 0;
}