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

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

//applet:IF_MODINFO(APPLET(modinfo, BB_DIR_SBIN, BB_SUID_DROP))

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

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

static const char *const shortcuts[] = {
    "filename", // -n
    "author",   // -a
    "description",  // -d
    "license",  // -l
    "parm",     // -p
    "version",  // the rest has no shortcut options
    "alias",
    "srcversion",
    "depends",
    "uts_release",
    "intree",
    "vermagic",
    "firmware",
};

enum {
    OPT_0 = (1 << 0), /* \0 as separator */
    OPT_F = (1 << 1), /* field name */
    /* first bits are for -nadlp options, the rest are for
     * fields not selectable with "shortcut" options
     */
    OPT_n = (1 << 2),
    OPT_TAGS = ((1 << ARRAY_SIZE(shortcuts)) - 1) << 2,
};

static void display(const char *data, const char *pattern)
{
    int flag = option_mask32 >> 1; /* shift out -0 bit */
    if (flag & (flag-1)) {
        /* more than one field to show: print "FIELD:" pfx */
        int n = printf("%s:", pattern);
        while (n++ < 16)
            bb_putchar(' ');
    }
    printf("%s%c", data, (option_mask32 & OPT_0) ? '\0' : '\n');
}

static void modinfo(const char *path, const char *version,
            const char *field)
{
    size_t len;
    int j;
    char *ptr, *the_module;
    char *allocated;
    int tags = option_mask32;

    allocated = NULL;
    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 = allocated = xasprintf("%s/%s/%s", CONFIG_DEFAULT_MODULES_DIR, version, path);
        the_module = xmalloc_open_zipped_read_close(path, &len);
        if (!the_module) {
            bb_error_msg("module '%s' not found", path);
            goto ret;
        }
    }

    for (j = 1; (1<<j) & (OPT_TAGS|OPT_F); j++) {
        const char *pattern;

        if (!((1<<j) & tags))
            continue;

        pattern = field;
        if ((1<<j) & OPT_TAGS)
            pattern = shortcuts[j-2];

        if (strcmp(pattern, shortcuts[0]) == 0) {
            /* "-n" or "-F filename" */
            display(path, shortcuts[0]);
            continue;
        }

        ptr = the_module;
        while (1) {
            char *after_pattern;

            ptr = memchr(ptr, *pattern, len - (ptr - (char*)the_module));
            if (ptr == NULL) /* no occurance left, done */
                break;
            after_pattern = is_prefixed_with(ptr, pattern);
            if (after_pattern && *after_pattern == '=') {
                /* field prefixes are 0x80 or 0x00 */
                if ((ptr[-1] & 0x7F) == 0x00) {
                    ptr = after_pattern + 1;
                    display(ptr, pattern);
                    ptr += strlen(ptr);
                }
            }
            ++ptr;
        }
    }
    free(the_module);
 ret:
    free(allocated);
}

//usage:#define modinfo_trivial_usage
//usage:       "[-adlpn0] [-F keyword] MODULE"
//usage:#define modinfo_full_usage "\n\n"
//usage:       "    -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  -n      Shortcut for '-F filename'"
//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)
{
    const char *field;
    char name[MODULE_NAME_LEN];
    struct utsname uts;
    parser_t *parser;
    char *colon, *tokens[2];
    unsigned opts;
    unsigned i;

    field = NULL;
    opt_complementary = "-1"; /* minimum one param */
    opts = getopt32(argv, "0F:nadlp", &field);
    /* If no field selected, show all */
    if (!(opts & (OPT_TAGS|OPT_F)))
        option_mask32 |= 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(bb_basename(tokens[0]), name);
        for (i = 0; argv[i]; i++) {
            if (fnmatch(argv[i], name, 0) == 0) {
                modinfo(tokens[0], uts.release, field);
                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, field);
        }
    }

    return 0;
}