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

   1 /* vi: set sw=4 ts=4: */
   2 /*
   3  * depmod - generate modules.dep
   4  * Copyright (c) 2008 Bernhard Reutner-Fischer
   5  * Copyrihgt (c) 2008 Timo Teras <timo.teras@iki.fi>
   6  * Copyright (c) 2008 Vladimir Dronnikov
   7  *
   8  * Licensed under GPLv2 or later, see file LICENSE in this source tree.
   9  */
  10
  11 //applet:IF_DEPMOD(APPLET(depmod, BB_DIR_SBIN, BB_SUID_DROP))
  12
  13 #include "libbb.h"
  14 #include "modutils.h"
  15 #include <sys/utsname.h> /* uname() */
  16
  17 /*
  18  * Theory of operation:
  19  * - iterate over all modules and record their full path
  20  * - iterate over all modules looking for "depends=" entries
  21  *   for each depends, look through our list of full paths and emit if found
  22  */
  23
  24 typedef struct module_info {
  25         struct module_info *next;
  26         char *name, *modname;
  27         llist_t *dependencies;
  28         llist_t *aliases;
  29         llist_t *symbols;
  30         struct module_info *dnext, *dprev;
  31 } module_info;
  32
  33 static int FAST_FUNC parse_module(const char *fname, struct stat *sb UNUSED_PARAM,
  34                                 void *data, int depth UNUSED_PARAM)
  35 {
  36         char modname[MODULE_NAME_LEN];
  37         module_info **first = (module_info **) data;
  38         char *image, *ptr;
  39         module_info *info;
  40         /* Arbitrary. Was sb->st_size, but that breaks .gz etc */
  41         size_t len = (64*1024*1024 - 4096);
  42
  43         if (strrstr(fname, ".ko") == NULL)
  44                 return TRUE;
  45
  46         image = xmalloc_open_zipped_read_close(fname, &len);
  47         info = xzalloc(sizeof(*info));
  48
  49         info->next = *first;
  50         *first = info;
  51
  52         info->dnext = info->dprev = info;
  53         info->name = xstrdup(fname + 2); /* skip "./" */
  54         info->modname = xstrdup(
  55                 filename2modname(
  56                         bb_get_last_path_component_nostrip(fname),
  57                         modname
  58         ));
  59         for (ptr = image; ptr < image + len - 10; ptr++) {
  60                 if (strncmp(ptr, "depends=", 8) == 0) {
  61                         char *u;
  62
  63                         ptr += 8;
  64                         for (u = ptr; *u; u++)
  65                                 if (*u == '-')
  66                                         *u = '_';
  67                         ptr += string_to_llist(ptr, &info->dependencies, ",");
  68                 } else if (ENABLE_FEATURE_MODUTILS_ALIAS
  69                  && strncmp(ptr, "alias=", 6) == 0
  70                 ) {
  71                         llist_add_to(&info->aliases, xstrdup(ptr + 6));
  72                         ptr += strlen(ptr);
  73                 } else if (ENABLE_FEATURE_MODUTILS_SYMBOLS
  74                  && strncmp(ptr, "__ksymtab_", 10) == 0
  75                 ) {
  76                         ptr += 10;
  77                         if (strncmp(ptr, "gpl", 3) == 0
  78                          || strcmp(ptr, "strings") == 0
  79                         ) {
  80                                 continue;
  81                         }
  82                         llist_add_to(&info->symbols, xstrdup(ptr));
  83                         ptr += strlen(ptr);
  84                 }
  85         }
  86         free(image);
  87
  88         return TRUE;
  89 }
  90
  91 static module_info *find_module(module_info *modules, const char *modname)
  92 {
  93         module_info *m;
  94
  95         for (m = modules; m != NULL; m = m->next)
  96                 if (strcmp(m->modname, modname) == 0)
  97                         return m;
  98         return NULL;
  99 }
 100
 101 static void order_dep_list(module_info *modules, module_info *start,
 102                         llist_t *add)
 103 {
 104         module_info *m;
 105         llist_t *n;
 106
 107         for (n = add; n != NULL; n = n->link) {
 108                 m = find_module(modules, n->data);
 109                 if (m == NULL)
 110                         continue;
 111
 112                 /* unlink current entry */
 113                 m->dnext->dprev = m->dprev;
 114                 m->dprev->dnext = m->dnext;
 115
 116                 /* and add it to tail */
 117                 m->dnext = start;
 118                 m->dprev = start->dprev;
 119                 start->dprev->dnext = m;
 120                 start->dprev = m;
 121
 122                 /* recurse */
 123                 order_dep_list(modules, start, m->dependencies);
 124         }
 125 }
 126
 127 static void xfreopen_write(const char *file, FILE *f)
 128 {
 129         if (freopen(file, "w", f) == NULL)
 130                 bb_perror_msg_and_die("can't open '%s'", file);
 131 }
 132
 133 //usage:#if !ENABLE_MODPROBE_SMALL
 134 //usage:#define depmod_trivial_usage "[-n] [-b BASE] [VERSION] [MODFILES]..."
 135 //usage:#define depmod_full_usage "\n\n"
 136 //usage:       "Generate modules.dep, alias, and symbols files"
 137 //usage:     "\n"
 138 //usage:     "\n        -b BASE Use BASE/lib/modules/VERSION"
 139 //usage:     "\n        -n      Dry run: print files to stdout"
 140 //usage:#endif
 141
 142 /* Upstream usage:
 143  * [-aAenv] [-C FILE or DIR] [-b BASE] [-F System.map] [VERSION] [MODFILES]...
 144  *      -a --all
 145  *              Probe all modules. Default if no MODFILES.
 146  *      -A --quick
 147  *              Check modules.dep's mtime against module files' mtimes.
 148  *      -b --basedir BASE
 149  *              Use $BASE/lib/modules/VERSION
 150  *      -C --config FILE or DIR
 151  *              Path to /etc/depmod.conf or /etc/depmod.d/
 152  *      -e --errsyms
 153  *              When combined with the -F option, this reports any symbols
 154  *              which are not supplied by other modules or kernel.
 155  *      -F --filesyms System.map
 156  *      -n --dry-run
 157  *              Print modules.dep etc to standard output
 158  *      -v --verbose
 159  *              Print to stdout all the symbols each module depends on
 160  *              and the module's file name which provides that symbol.
 161  *      -r      No-op
 162  *      -u      No-op
 163  *      -q      No-op
 164  *
 165  * So far we only support: [-n] [-b BASE] [VERSION] [MODFILES]...
 166  * Accepted but ignored:
 167  * -aAe
 168  * -F System.map
 169  * -C FILE/DIR
 170  *
 171  * Not accepted: -v
 172  */
 173 enum {
 174         //OPT_a = (1 << 0), /* All modules, ignore mods in argv */
 175         //OPT_A = (1 << 1), /* Only emit .ko that are newer than modules.dep file */
 176         OPT_b = (1 << 2), /* base directory when modules are in staging area */
 177         //OPT_e = (1 << 3), /* with -F, print unresolved symbols */
 178         //OPT_F = (1 << 4), /* System.map that contains the symbols */
 179         OPT_n = (1 << 5), /* dry-run, print to stdout only */
 180         OPT_r = (1 << 6), /* Compat dummy. Linux Makefile uses it */
 181         OPT_u = (1 << 7), /* -u,--unresolved-error: ignored */
 182         OPT_q = (1 << 8), /* -q,--quiet: ignored */
 183         OPT_C = (1 << 9), /* -C,--config etc_modules_conf: ignored */
 184 };
 185
 186 int depmod_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
 187 int depmod_main(int argc UNUSED_PARAM, char **argv)
 188 {
 189         module_info *modules, *m, *dep;
 190         const char *moddir_base = "/";
 191         char *moddir, *version;
 192         struct utsname uts;
 193         int tmp;
 194
 195         getopt32(argv, "aAb:eF:nruqC:", &moddir_base, NULL, NULL);
 196         argv += optind;
 197
 198         /* goto modules location */
 199         xchdir(moddir_base);
 200
 201         /* If a version is provided, then that kernel version's module directory
 202          * is used, rather than the current kernel version (as returned by
 203          * "uname -r").  */
 204         if (*argv && sscanf(*argv, "%u.%u.%u", &tmp, &tmp, &tmp) == 3) {
 205                 version = *argv++;
 206         } else {
 207                 uname(&uts);
 208                 version = uts.release;
 209         }
 210         moddir = concat_path_file(&CONFIG_DEFAULT_MODULES_DIR[1], version);
 211         xchdir(moddir);
 212         if (ENABLE_FEATURE_CLEAN_UP)
 213                 free(moddir);
 214
 215         /* Scan modules */
 216         modules = NULL;
 217         if (*argv) {
 218                 do {
 219                         parse_module(*argv, /*sb (unused):*/ NULL, &modules, 0);
 220                 } while (*++argv);
 221         } else {
 222                 recursive_action(".", ACTION_RECURSE,
 223                                 parse_module, NULL, &modules, 0);
 224         }
 225
 226         /* Generate dependency and alias files */
 227         if (!(option_mask32 & OPT_n))
 228                 xfreopen_write(CONFIG_DEFAULT_DEPMOD_FILE, stdout);
 229         for (m = modules; m != NULL; m = m->next) {
 230                 printf("%s:", m->name);
 231
 232                 order_dep_list(modules, m, m->dependencies);
 233                 while (m->dnext != m) {
 234                         dep = m->dnext;
 235                         printf(" %s", dep->name);
 236
 237                         /* unlink current entry */
 238                         dep->dnext->dprev = dep->dprev;
 239                         dep->dprev->dnext = dep->dnext;
 240                         dep->dnext = dep->dprev = dep;
 241                 }
 242                 bb_putchar('\n');
 243         }
 244
 245 #if ENABLE_FEATURE_MODUTILS_ALIAS
 246         if (!(option_mask32 & OPT_n))
 247                 xfreopen_write("modules.alias", stdout);
 248         for (m = modules; m != NULL; m = m->next) {
 249                 char modname[MODULE_NAME_LEN];
 250                 const char *fname = bb_basename(m->name);
 251                 filename2modname(fname, modname);
 252                 while (m->aliases) {
 253                         /* Last word can well be m->modname instead,
 254                          * but depmod from module-init-tools 3.4
 255                          * uses module basename, i.e., no s/-/_/g.
 256                          * (pathname and .ko.* are still stripped)
 257                          * Mimicking that... */
 258                         printf("alias %s %s\n",
 259                                 (char*)llist_pop(&m->aliases),
 260                                 modname);
 261                 }
 262         }
 263 #endif
 264 #if ENABLE_FEATURE_MODUTILS_SYMBOLS
 265         if (!(option_mask32 & OPT_n))
 266                 xfreopen_write("modules.symbols", stdout);
 267         for (m = modules; m != NULL; m = m->next) {
 268                 char modname[MODULE_NAME_LEN];
 269                 const char *fname = bb_basename(m->name);
 270                 filename2modname(fname, modname);
 271                 while (m->symbols) {
 272                         printf("alias symbol:%s %s\n",
 273                                 (char*)llist_pop(&m->symbols),
 274                                 modname);
 275                 }
 276         }
 277 #endif
 278
 279         if (ENABLE_FEATURE_CLEAN_UP) {
 280                 while (modules) {
 281                         module_info *old = modules;
 282                         modules = modules->next;
 283                         free(old->name);
 284                         free(old->modname);
 285                         free(old);
 286                 }
 287         }
 288
 289         return EXIT_SUCCESS;
 290 }