source: MondoRescue/branches/3.0/mindi-busybox/modutils/modinfo.c@ 2899

/* vi: set sw=4 ts=4: */
/*
 * modinfo - retrieve module info
 * Copyright (c) 2008 Pascal Bellard
 *
 * Licensed under GPLv2 or later, see file LICENSE in this source tree.
 */

//applet:IF_MODINFO(APPLET(modinfo, _BB_DIR_SBIN, _BB_SUID_DROP))

//kbuild:lib-$(CONFIG_MODINFO) += modinfo.o modutils.o

//config:config MODINFO
//config:   bool "modinfo"
//config:   default y
//config:   help
//config:     Show information about a Linux Kernel module

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


enum {
    OPT_TAGS = (1 << 6) - 1,
    OPT_F = (1 << 6), /* field name */
    OPT_0 = (1 << 7),  /* \0 as separator */
};

struct modinfo_env {
    char *field;
    int tags;
};

static int display(const char *data, const char *pattern, int flag)
{
    if (flag) {
        int n = printf("%s:", pattern);
        while (n++ < 16)
            bb_putchar(' ');
    }
    return printf("%s%c", data, (option_mask32 & OPT_0) ? '\0' : '\n');
}

static void modinfo(const char *path, const char *version,
            struct modinfo_env *env)
{
    static const char *const shortcuts[] = {
        "filename",
        "description",
        "author",
        "license",
        "vermagic",
        "parm",
    };
    size_t len;
    int j, length;
    char *ptr, *the_module;
    const char *field = env->field;
    int tags = env->tags;

    if (tags & 1) { /* filename */
        display(path, shortcuts[0], 1 != tags);
    }

    len = MAXINT(ssize_t);
    the_module = xmalloc_open_zipped_read_close(path, &len);
    if (!the_module) {
        if (path[0] == '/')
            return;
        /* Newer depmod puts relative paths in modules.dep */
        path = xasprintf("%s/%s/%s", CONFIG_DEFAULT_MODULES_DIR, version, path);
        the_module = xmalloc_open_zipped_read_close(path, &len);
        free((char*)path);
        if (!the_module)
            return;
    }

    if (field)
        tags |= OPT_F;
    for (j = 1; (1<<j) & (OPT_TAGS + OPT_F); j++) {
        const char *pattern = field;
        if ((1<<j) & OPT_TAGS)
            pattern = shortcuts[j];
        if (!((1<<j) & tags))
            continue;
        length = strlen(pattern);
        ptr = the_module;
        while (1) {
            ptr = memchr(ptr, *pattern, len - (ptr - (char*)the_module));
            if (ptr == NULL) /* no occurance left, done */
                break;
            if (strncmp(ptr, pattern, length) == 0 && ptr[length] == '=') {
                ptr += length + 1;
                ptr += display(ptr, pattern, (1<<j) != tags);
            }
            ++ptr;
        }
    }
    free(the_module);
}

//usage:#define modinfo_trivial_usage
//usage:       "[-adlp0] [-F keyword] MODULE"
//usage:#define modinfo_full_usage "\n\n"
//usage:       "Options:"
//usage:     "\n    -a      Shortcut for '-F author'"
//usage:     "\n    -d      Shortcut for '-F description'"
//usage:     "\n    -l      Shortcut for '-F license'"
//usage:     "\n    -p      Shortcut for '-F parm'"
//usage:     "\n    -F keyword  Keyword to look for"
//usage:     "\n    -0      Separate output with NULs"
//usage:#define modinfo_example_usage
//usage:       "$ modinfo -F vermagic loop\n"

int modinfo_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int modinfo_main(int argc UNUSED_PARAM, char **argv)
{
    struct modinfo_env env;
    char name[MODULE_NAME_LEN];
    struct utsname uts;
    parser_t *parser;
    char *colon, *tokens[2];
    unsigned opts;
    unsigned i;

    env.field = NULL;
    opt_complementary = "-1"; /* minimum one param */
    opts = getopt32(argv, "fdalvpF:0", &env.field);
    env.tags = opts & OPT_TAGS ? opts & OPT_TAGS : OPT_TAGS;
    argv += optind;

    uname(&uts);
    parser = config_open2(
        xasprintf("%s/%s/%s", CONFIG_DEFAULT_MODULES_DIR, uts.release, CONFIG_DEFAULT_DEPMOD_FILE),
        xfopen_for_read
    );

    while (config_read(parser, tokens, 2, 1, "# \t", PARSE_NORMAL)) {
        colon = last_char_is(tokens[0], ':');
        if (colon == NULL)
            continue;
        *colon = '\0';
        filename2modname(tokens[0], name);
        for (i = 0; argv[i]; i++) {
            if (fnmatch(argv[i], name, 0) == 0) {
                modinfo(tokens[0], uts.release, &env);
                argv[i] = (char *) "";
            }
        }
    }
    if (ENABLE_FEATURE_CLEAN_UP)
        config_close(parser);

    for (i = 0; argv[i]; i++) {
        if (argv[i][0]) {
            modinfo(argv[i], uts.release, &env);
        }
    }

    return 0;
}