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
   9 //applet:IF_MODINFO(APPLET(modinfo, BB_DIR_SBIN, BB_SUID_DROP))
  10
  11 //kbuild:lib-$(CONFIG_MODINFO) += modinfo.o modutils.o
  12
  13 //config:config MODINFO
  14 //config:       bool "modinfo"
  15 //config:       default y
  16 //config:       select PLATFORM_LINUX
  17 //config:       help
  18 //config:         Show information about a Linux Kernel module
  19
  20 #include <fnmatch.h>
  21 #include <sys/utsname.h> /* uname() */
  22 #include "libbb.h"
  23 #include "modutils.h"
  24
  25
  26 enum {
  27         OPT_TAGS = (1 << 8) - 1,
  28         OPT_F = (1 << 8), /* field name */
  29         OPT_0 = (1 << 9),  /* \0 as separator */
  30 };
  31
  32 struct modinfo_env {
  33         char *field;
  34         int tags;
  35 };
  36
  37 static int display(const char *data, const char *pattern, int flag)
  38 {
  39         if (flag) {
  40                 int n = printf("%s:", pattern);
  41                 while (n++ < 16)
  42                         bb_putchar(' ');
  43         }
  44         return printf("%s%c", data, (option_mask32 & OPT_0) ? '\0' : '\n');
  45 }
  46
  47 static void modinfo(const char *path, const char *version,
  48                         const struct modinfo_env *env)
  49 {
  50         static const char *const shortcuts[] = {
  51                 "filename",
  52                 "description",
  53                 "author",
  54                 "license",
  55                 "vermagic",
  56                 "parm",
  57                 "firmware",
  58                 "depends",
  59         };
  60         size_t len;
  61         int j, length;
  62         char *ptr, *the_module;
  63         const char *field = env->field;
  64         int tags = env->tags;
  65
  66         if (tags & 1) { /* filename */
  67                 display(path, shortcuts[0], 1 != tags);
  68         }
  69
  70         len = MAXINT(ssize_t);
  71         the_module = xmalloc_open_zipped_read_close(path, &len);
  72         if (!the_module) {
  73                 if (path[0] == '/')
  74                         return;
  75                 /* Newer depmod puts relative paths in modules.dep */
  76                 path = xasprintf("%s/%s/%s", CONFIG_DEFAULT_MODULES_DIR, version, path);
  77                 the_module = xmalloc_open_zipped_read_close(path, &len);
  78                 free((char*)path);
  79                 if (!the_module)
  80                         return;
  81         }
  82
  83         if (field)
  84                 tags |= OPT_F;
  85         for (j = 1; (1<<j) & (OPT_TAGS + OPT_F); j++) {
  86                 const char *pattern;
  87
  88                 if (!((1<<j) & tags))
  89                         continue;
  90                 pattern = field;
  91                 if ((1<<j) & OPT_TAGS)
  92                         pattern = shortcuts[j];
  93                 length = strlen(pattern);
  94                 ptr = the_module;
  95                 while (1) {
  96                         ptr = memchr(ptr, *pattern, len - (ptr - (char*)the_module));
  97                         if (ptr == NULL) /* no occurance left, done */
  98                                 break;
  99                         if (strncmp(ptr, pattern, length) == 0 && ptr[length] == '=') {
 100                                 ptr += length + 1;
 101                                 ptr += display(ptr, pattern, (1<<j) != tags);
 102                         }
 103                         ++ptr;
 104                 }
 105         }
 106         free(the_module);
 107 }
 108
 109 //usage:#define modinfo_trivial_usage
 110 //usage:       "[-adlp0] [-F keyword] MODULE"
 111 //usage:#define modinfo_full_usage "\n\n"
 112 //usage:       "        -a              Shortcut for '-F author'"
 113 //usage:     "\n        -d              Shortcut for '-F description'"
 114 //usage:     "\n        -l              Shortcut for '-F license'"
 115 //usage:     "\n        -p              Shortcut for '-F parm'"
 116 //usage:     "\n        -F keyword      Keyword to look for"
 117 //usage:     "\n        -0              Separate output with NULs"
 118 //usage:#define modinfo_example_usage
 119 //usage:       "$ modinfo -F vermagic loop\n"
 120
 121 int modinfo_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
 122 int modinfo_main(int argc UNUSED_PARAM, char **argv)
 123 {
 124         struct modinfo_env env;
 125         char name[MODULE_NAME_LEN];
 126         struct utsname uts;
 127         parser_t *parser;
 128         char *colon, *tokens[2];
 129         unsigned opts;
 130         unsigned i;
 131
 132         env.field = NULL;
 133         opt_complementary = "-1"; /* minimum one param */
 134         opts = getopt32(argv, "fdalvpF:0", &env.field);
 135         env.tags = opts & OPT_TAGS ? opts & OPT_TAGS : OPT_TAGS;
 136         argv += optind;
 137
 138         uname(&uts);
 139         parser = config_open2(
 140                 xasprintf("%s/%s/%s", CONFIG_DEFAULT_MODULES_DIR, uts.release, CONFIG_DEFAULT_DEPMOD_FILE),
 141                 xfopen_for_read
 142         );
 143
 144         while (config_read(parser, tokens, 2, 1, "# \t", PARSE_NORMAL)) {
 145                 colon = last_char_is(tokens[0], ':');
 146                 if (colon == NULL)
 147                         continue;
 148                 *colon = '\0';
 149                 filename2modname(tokens[0], name);
 150                 for (i = 0; argv[i]; i++) {
 151                         if (fnmatch(argv[i], name, 0) == 0) {
 152                                 modinfo(tokens[0], uts.release, &env);
 153                                 argv[i] = (char *) "";
 154                         }
 155                 }
 156         }
 157         if (ENABLE_FEATURE_CLEAN_UP)
 158                 config_close(parser);
 159
 160         for (i = 0; argv[i]; i++) {
 161                 if (argv[i][0]) {
 162                         modinfo(argv[i], uts.release, &env);
 163                 }
 164         }
 165
 166         return 0;
 167 }