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