source: MondoRescue/branches/3.3/mindi-busybox/modutils/depmod.c@ 3621

/* vi: set sw=4 ts=4: */
/*
 * depmod - generate modules.dep
 * Copyright (c) 2008 Bernhard Reutner-Fischer
 * Copyrihgt (c) 2008 Timo Teras <timo.teras@iki.fi>
 * Copyright (c) 2008 Vladimir Dronnikov
 *
 * Licensed under GPLv2 or later, see file LICENSE in this source tree.
 */

//applet:IF_DEPMOD(APPLET(depmod, BB_DIR_SBIN, BB_SUID_DROP))

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

/*
 * Theory of operation:
 * - iterate over all modules and record their full path
 * - iterate over all modules looking for "depends=" entries
 *   for each depends, look through our list of full paths and emit if found
 */

static int FAST_FUNC parse_module(const char *fname, struct stat *sb UNUSED_PARAM,
                void *data, int depth UNUSED_PARAM)
{
    module_db *modules = data;
    char *image, *ptr;
    module_entry *e;

    /* Arbitrary. Was sb->st_size, but that breaks .gz etc */
    size_t len = (64*1024*1024 - 4096);

    if (strrstr(fname, ".ko") == NULL)
        return TRUE;

    image = xmalloc_open_zipped_read_close(fname, &len);

    e = moddb_get_or_create(modules, bb_get_last_path_component_nostrip(fname));
    e->name = xstrdup(fname + 2); /* skip "./" */

    for (ptr = image; ptr < image + len - 10; ptr++) {
        if (is_prefixed_with(ptr, "depends=")) {
            char *u;

            ptr += 8;
            for (u = ptr; *u; u++)
                if (*u == '-')
                    *u = '_';
            ptr += string_to_llist(ptr, &e->deps, ",");
        } else if (ENABLE_FEATURE_MODUTILS_ALIAS
         && is_prefixed_with(ptr, "alias=")
        ) {
            llist_add_to(&e->aliases, xstrdup(ptr + 6));
            ptr += strlen(ptr);
        } else if (ENABLE_FEATURE_MODUTILS_SYMBOLS
         && is_prefixed_with(ptr, "__ksymtab_")
        ) {
            ptr += 10;
            if (is_prefixed_with(ptr, "gpl")
             || strcmp(ptr, "strings") == 0
            ) {
                continue;
            }
            llist_add_to(&e->symbols, xstrdup(ptr));
            ptr += strlen(ptr);
        }
    }
    free(image);

    return TRUE;
}

static void order_dep_list(module_db *modules, module_entry *start, llist_t *add)
{
    module_entry *m;
    llist_t *n;

    for (n = add; n != NULL; n = n->link) {
        m = moddb_get(modules, n->data);
        if (m == NULL)
            continue;

        /* unlink current entry */
        m->dnext->dprev = m->dprev;
        m->dprev->dnext = m->dnext;

        /* and add it to tail */
        m->dnext = start;
        m->dprev = start->dprev;
        start->dprev->dnext = m;
        start->dprev = m;

        /* recurse */
        order_dep_list(modules, start, m->deps);
    }
}

static void xfreopen_write(const char *file, FILE *f)
{
    if (freopen(file, "w", f) == NULL)
        bb_perror_msg_and_die("can't open '%s'", file);
}

//usage:#if !ENABLE_MODPROBE_SMALL
//usage:#define depmod_trivial_usage "[-n] [-b BASE] [VERSION] [MODFILES]..."
//usage:#define depmod_full_usage "\n\n"
//usage:       "Generate modules.dep, alias, and symbols files"
//usage:     "\n"
//usage:     "\n    -b BASE Use BASE/lib/modules/VERSION"
//usage:     "\n    -n  Dry run: print files to stdout"
//usage:#endif

/* Upstream usage:
 * [-aAenv] [-C FILE or DIR] [-b BASE] [-F System.map] [VERSION] [MODFILES]...
 *  -a --all
 *      Probe all modules. Default if no MODFILES.
 *  -A --quick
 *      Check modules.dep's mtime against module files' mtimes.
 *  -b --basedir BASE
 *      Use $BASE/lib/modules/VERSION
 *  -C --config FILE or DIR
 *      Path to /etc/depmod.conf or /etc/depmod.d/
 *  -e --errsyms
 *      When combined with the -F option, this reports any symbols
 *      which are not supplied by other modules or kernel.
 *  -F --filesyms System.map
 *  -n --dry-run
 *      Print modules.dep etc to standard output
 *  -v --verbose
 *      Print to stdout all the symbols each module depends on
 *      and the module's file name which provides that symbol.
 *  -r  No-op
 *  -u  No-op
 *  -q  No-op
 *
 * So far we only support: [-n] [-b BASE] [VERSION] [MODFILES]...
 * Accepted but ignored:
 * -aAe
 * -F System.map
 * -C FILE/DIR
 *
 * Not accepted: -v
 */
enum {
    //OPT_a = (1 << 0), /* All modules, ignore mods in argv */
    //OPT_A = (1 << 1), /* Only emit .ko that are newer than modules.dep file */
    OPT_b = (1 << 2), /* base directory when modules are in staging area */
    //OPT_e = (1 << 3), /* with -F, print unresolved symbols */
    //OPT_F = (1 << 4), /* System.map that contains the symbols */
    OPT_n = (1 << 5), /* dry-run, print to stdout only */
    OPT_r = (1 << 6), /* Compat dummy. Linux Makefile uses it */
    OPT_u = (1 << 7), /* -u,--unresolved-error: ignored */
    OPT_q = (1 << 8), /* -q,--quiet: ignored */
    OPT_C = (1 << 9), /* -C,--config etc_modules_conf: ignored */
};

int depmod_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int depmod_main(int argc UNUSED_PARAM, char **argv)
{
    module_db modules;
    module_entry *m, *dep;
    const char *moddir_base = "/";
    char *moddir, *version;
    struct utsname uts;
    unsigned i;
    int tmp;

    getopt32(argv, "aAb:eF:nruqC:", &moddir_base, NULL, NULL);
    argv += optind;

    /* goto modules location */
    xchdir(moddir_base);

    /* If a version is provided, then that kernel version's module directory
     * is used, rather than the current kernel version (as returned by
     * "uname -r").  */
    if (*argv && sscanf(*argv, "%u.%u.%u", &tmp, &tmp, &tmp) == 3) {
        version = *argv++;
    } else {
        uname(&uts);
        version = uts.release;
    }
    moddir = concat_path_file(&CONFIG_DEFAULT_MODULES_DIR[1], version);
    xchdir(moddir);
    if (ENABLE_FEATURE_CLEAN_UP)
        free(moddir);

    /* Scan modules */
    memset(&modules, 0, sizeof(modules));
    if (*argv) {
        do {
            parse_module(*argv, /*sb (unused):*/ NULL, &modules, 0);
        } while (*++argv);
    } else {
        recursive_action(".", ACTION_RECURSE,
                parse_module, NULL, &modules, 0);
    }

    /* Generate dependency and alias files */
    if (!(option_mask32 & OPT_n))
        xfreopen_write(CONFIG_DEFAULT_DEPMOD_FILE, stdout);

    moddb_foreach_module(&modules, m, i) {
        printf("%s:", m->name);

        order_dep_list(&modules, m, m->deps);
        while (m->dnext != m) {
            dep = m->dnext;
            printf(" %s", dep->name);

            /* unlink current entry */
            dep->dnext->dprev = dep->dprev;
            dep->dprev->dnext = dep->dnext;
            dep->dnext = dep->dprev = dep;
        }
        bb_putchar('\n');
    }

#if ENABLE_FEATURE_MODUTILS_ALIAS
    if (!(option_mask32 & OPT_n))
        xfreopen_write("modules.alias", stdout);
    moddb_foreach_module(&modules, m, i) {
        while (m->aliases) {
            /*
             * Last word used to be a basename
             * (filename with path and .ko.* stripped)
             * at the time of module-init-tools 3.4.
             * kmod v.12 uses module name, i.e., s/-/_/g.
             */
            printf("alias %s %s\n",
                (char*)llist_pop(&m->aliases),
                m->modname);
        }
    }
#endif
#if ENABLE_FEATURE_MODUTILS_SYMBOLS
    if (!(option_mask32 & OPT_n))
        xfreopen_write("modules.symbols", stdout);
    moddb_foreach_module(&modules, m, i) {
        while (m->symbols) {
            printf("alias symbol:%s %s\n",
                (char*)llist_pop(&m->symbols),
                m->modname);
        }
    }
#endif

    if (ENABLE_FEATURE_CLEAN_UP)
        moddb_free(&modules);

    return EXIT_SUCCESS;
}