release/src/router/busybox/modutils/modinfo.c

   1 /* vi: set sw=4 ts=4: */
   2 /*
   3  * modinfo - retrieve module info
   4  * Copyright (c) 2008 Pascal Bellard
   5  *
   6  * Licensed under GPLv2 or later, see file LICENSE in this source tree.
   7  */
   8 //config:config MODINFO
   9 //config:       bool "modinfo"
  10 //config:       default y
  11 //config:       select PLATFORM_LINUX
  12 //config:       help
  13 //config:         Show information about a Linux Kernel module
  14
  15 //applet:IF_MODINFO(APPLET(modinfo, BB_DIR_SBIN, BB_SUID_DROP))
  16
  17 //kbuild:lib-$(CONFIG_MODINFO) += modinfo.o modutils.o
  18
  19 #include <fnmatch.h>
  20 #include <sys/utsname.h> /* uname() */
  21 #include "libbb.h"
  22 #include "modutils.h"
  23
  24 static const char *const shortcuts[] = {
  25         "filename",     // -n
  26         "author",       // -a
  27         "description",  // -d
  28         "license",      // -l
  29         "parm",         // -p
  30         "version",      // the rest has no shortcut options
  31         "alias",
  32         "srcversion",
  33         "depends",
  34         "uts_release",
  35         "intree",
  36         "vermagic",
  37         "firmware",
  38 };
  39
  40 enum {
  41         OPT_0 = (1 << 0), /* \0 as separator */
  42         OPT_F = (1 << 1), /* field name */
  43         /* first bits are for -nadlp options, the rest are for
  44          * fields not selectable with "shortcut" options
  45          */
  46         OPT_n = (1 << 2),
  47         OPT_TAGS = ((1 << ARRAY_SIZE(shortcuts)) - 1) << 2,
  48 };
  49
  50 static void display(const char *data, const char *pattern)
  51 {
  52         int flag = option_mask32 >> 1; /* shift out -0 bit */
  53         if (flag & (flag-1)) {
  54                 /* more than one field to show: print "FIELD:" pfx */
  55                 int n = printf("%s:", pattern);
  56                 while (n++ < 16)
  57                         bb_putchar(' ');
  58         }
  59         printf("%s%c", data, (option_mask32 & OPT_0) ? '\0' : '\n');
  60 }
  61
  62 static void modinfo(const char *path, const char *version,
  63                         const char *field)
  64 {
  65         size_t len;
  66         int j;
  67         char *ptr, *the_module;
  68         char *allocated;
  69         int tags = option_mask32;
  70
  71         allocated = NULL;
  72         len = MAXINT(ssize_t);
  73         the_module = xmalloc_open_zipped_read_close(path, &len);
  74         if (!the_module) {
  75                 if (path[0] == '/')
  76                         return;
  77                 /* Newer depmod puts relative paths in modules.dep */
  78                 path = allocated = xasprintf("%s/%s/%s", CONFIG_DEFAULT_MODULES_DIR, version, path);
  79                 the_module = xmalloc_open_zipped_read_close(path, &len);
  80                 if (!the_module) {
  81                         bb_error_msg("module '%s' not found", path);
  82                         goto ret;
  83                 }
  84         }
  85
  86         for (j = 1; (1<<j) & (OPT_TAGS|OPT_F); j++) {
  87                 const char *pattern;
  88
  89                 if (!((1<<j) & tags))
  90                         continue;
  91
  92                 pattern = field;
  93                 if ((1<<j) & OPT_TAGS)
  94                         pattern = shortcuts[j-2];
  95
  96                 if (strcmp(pattern, shortcuts[0]) == 0) {
  97                         /* "-n" or "-F filename" */
  98                         display(path, shortcuts[0]);
  99                         continue;
 100                 }
 101
 102                 ptr = the_module;
 103                 while (1) {
 104                         char *after_pattern;
 105
 106                         ptr = memchr(ptr, *pattern, len - (ptr - (char*)the_module));
 107                         if (ptr == NULL) /* no occurance left, done */
 108                                 break;
 109                         after_pattern = is_prefixed_with(ptr, pattern);
 110                         if (after_pattern && *after_pattern == '=') {
 111                                 /* field prefixes are 0x80 or 0x00 */
 112                                 if ((ptr[-1] & 0x7F) == 0x00) {
 113                                         ptr = after_pattern + 1;
 114                                         display(ptr, pattern);
 115                                         ptr += strlen(ptr);
 116                                 }
 117                         }
 118                         ++ptr;
 119                 }
 120         }
 121         free(the_module);
 122  ret:
 123         free(allocated);
 124 }
 125
 126 //usage:#define modinfo_trivial_usage
 127 //usage:       "[-adlpn0] [-F keyword] MODULE"
 128 //usage:#define modinfo_full_usage "\n\n"
 129 //usage:       "        -a              Shortcut for '-F author'"
 130 //usage:     "\n        -d              Shortcut for '-F description'"
 131 //usage:     "\n        -l              Shortcut for '-F license'"
 132 //usage:     "\n        -p              Shortcut for '-F parm'"
 133 ////usage:     "\n      -n              Shortcut for '-F filename'"
 134 //usage:     "\n        -F keyword      Keyword to look for"
 135 //usage:     "\n        -0              Separate output with NULs"
 136 //usage:#define modinfo_example_usage
 137 //usage:       "$ modinfo -F vermagic loop\n"
 138
 139 int modinfo_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
 140 int modinfo_main(int argc UNUSED_PARAM, char **argv)
 141 {
 142         const char *field;
 143         char name[MODULE_NAME_LEN];
 144         struct utsname uts;
 145         parser_t *parser;
 146         char *colon, *tokens[2];
 147         unsigned opts;
 148         unsigned i;
 149
 150         field = NULL;
 151         opt_complementary = "-1"; /* minimum one param */
 152         opts = getopt32(argv, "0F:nadlp", &field);
 153         /* If no field selected, show all */
 154         if (!(opts & (OPT_TAGS|OPT_F)))
 155                 option_mask32 |= OPT_TAGS;
 156         argv += optind;
 157
 158         uname(&uts);
 159         parser = config_open2(
 160                 xasprintf("%s/%s/%s", CONFIG_DEFAULT_MODULES_DIR, uts.release, CONFIG_DEFAULT_DEPMOD_FILE),
 161                 xfopen_for_read
 162         );
 163
 164         while (config_read(parser, tokens, 2, 1, "# \t", PARSE_NORMAL)) {
 165                 colon = last_char_is(tokens[0], ':');
 166                 if (colon == NULL)
 167                         continue;
 168                 *colon = '\0';
 169                 filename2modname(bb_basename(tokens[0]), name);
 170                 for (i = 0; argv[i]; i++) {
 171                         if (fnmatch(argv[i], name, 0) == 0) {
 172                                 modinfo(tokens[0], uts.release, field);
 173                                 argv[i] = (char *) "";
 174                         }
 175                 }
 176         }
 177         if (ENABLE_FEATURE_CLEAN_UP)
 178                 config_close(parser);
 179
 180         for (i = 0; argv[i]; i++) {
 181                 if (argv[i][0]) {
 182                         modinfo(argv[i], uts.release, field);
 183                 }
 184         }
 185
 186         return 0;
 187 }