source: MondoRescue/branches/3.3/mindi-busybox/modutils/modprobe.c@ 3865

/* vi: set sw=4 ts=4: */
/*
 * Modprobe written from scratch for BusyBox
 *
 * Copyright (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_MODPROBE(APPLET(modprobe, BB_DIR_SBIN, BB_SUID_DROP))

#include "libbb.h"
#include "modutils.h"
#include <sys/utsname.h>
#include <fnmatch.h>

#if 1
#define DBG(...) ((void)0)
#else
#define DBG(fmt, ...) bb_error_msg("%s: " fmt, __func__, ## __VA_ARGS__)
#endif

/* Note that unlike older versions of modules.dep/depmod (busybox and m-i-t),
 * we expect the full dependency list to be specified in modules.dep.
 * Older versions would only export the direct dependency list.
 */


//usage:#if !ENABLE_MODPROBE_SMALL
//usage:#define modprobe_notes_usage
//usage:    "modprobe can (un)load a stack of modules, passing each module options (when\n"
//usage:    "loading). modprobe uses a configuration file to determine what option(s) to\n"
//usage:    "pass each module it loads.\n"
//usage:    "\n"
//usage:    "The configuration file is searched (in this order):\n"
//usage:    "\n"
//usage:    "    /etc/modprobe.conf (2.6 only)\n"
//usage:    "    /etc/modules.conf\n"
//usage:    "    /etc/conf.modules (deprecated)\n"
//usage:    "\n"
//usage:    "They all have the same syntax (see below). If none is present, it is\n"
//usage:    "_not_ an error; each loaded module is then expected to load without\n"
//usage:    "options. Once a file is found, the others are tested for.\n"
//usage:    "\n"
//usage:    "/etc/modules.conf entry format:\n"
//usage:    "\n"
//usage:    "  alias <alias_name> <mod_name>\n"
//usage:    "    Makes it possible to modprobe alias_name, when there is no such module.\n"
//usage:    "    It makes sense if your mod_name is long, or you want a more representative\n"
//usage:    "    name for that module (eg. 'scsi' in place of 'aha7xxx').\n"
//usage:    "    This makes it also possible to use a different set of options (below) for\n"
//usage:    "    the module and the alias.\n"
//usage:    "    A module can be aliased more than once.\n"
//usage:    "\n"
//usage:    "  options <mod_name|alias_name> <symbol=value...>\n"
//usage:    "    When loading module mod_name (or the module aliased by alias_name), pass\n"
//usage:    "    the \"symbol=value\" pairs as option to that module.\n"
//usage:    "\n"
//usage:    "Sample /etc/modules.conf file:\n"
//usage:    "\n"
//usage:    "  options tulip irq=3\n"
//usage:    "  alias tulip tulip2\n"
//usage:    "  options tulip2 irq=4 io=0x308\n"
//usage:    "\n"
//usage:    "Other functionality offered by 'classic' modprobe is not available in\n"
//usage:    "this implementation.\n"
//usage:    "\n"
//usage:    "If module options are present both in the config file, and on the command line,\n"
//usage:    "then the options from the command line will be passed to the module _after_\n"
//usage:    "the options from the config file. That way, you can have defaults in the config\n"
//usage:    "file, and override them for a specific usage from the command line.\n"
//usage:#define modprobe_example_usage
//usage:       "(with the above /etc/modules.conf):\n\n"
//usage:       "$ modprobe tulip\n"
//usage:       "   will load the module 'tulip' with default option 'irq=3'\n\n"
//usage:       "$ modprobe tulip irq=5\n"
//usage:       "   will load the module 'tulip' with option 'irq=5', thus overriding the default\n\n"
//usage:       "$ modprobe tulip2\n"
//usage:       "   will load the module 'tulip' with default options 'irq=4 io=0x308',\n"
//usage:       "   which are the default for alias 'tulip2'\n\n"
//usage:       "$ modprobe tulip2 irq=8\n"
//usage:       "   will load the module 'tulip' with default options 'irq=4 io=0x308 irq=8',\n"
//usage:       "   which are the default for alias 'tulip2' overridden by the option 'irq=8'\n\n"
//usage:       "   from the command line\n\n"
//usage:       "$ modprobe tulip2 irq=2 io=0x210\n"
//usage:       "   will load the module 'tulip' with default options 'irq=4 io=0x308 irq=4 io=0x210',\n"
//usage:       "   which are the default for alias 'tulip2' overridden by the options 'irq=2 io=0x210'\n\n"
//usage:       "   from the command line\n"
//usage:
//usage:#define modprobe_trivial_usage
//usage:    "[-alrqvsD" IF_FEATURE_MODPROBE_BLACKLIST("b") "]"
//usage:    " MODULE [SYMBOL=VALUE]..."
//usage:#define modprobe_full_usage "\n\n"
//usage:       "    -a  Load multiple MODULEs"
//usage:     "\n    -l  List (MODULE is a pattern)"
//usage:     "\n    -r  Remove MODULE (stacks) or do autoclean"
//usage:     "\n    -q  Quiet"
//usage:     "\n    -v  Verbose"
//usage:     "\n    -s  Log to syslog"
//usage:     "\n    -D  Show dependencies"
//usage:    IF_FEATURE_MODPROBE_BLACKLIST(
//usage:     "\n    -b  Apply blacklist to module names too"
//usage:    )
//usage:#endif /* !ENABLE_MODPROBE_SMALL */

/* Note: usage text doesn't document various 2.4 options
 * we pull in through INSMOD_OPTS define
 * Note2: -b is always accepted, but if !FEATURE_MODPROBE_BLACKLIST,
 * it is a no-op.
 */
#define MODPROBE_OPTS  "alrDb"
/* -a and -D _are_ in fact compatible */
#define MODPROBE_COMPLEMENTARY ("q-v:v-q:l--arD:r--alD:a--lr:D--rl")
//#define MODPROBE_OPTS  "acd:lnrt:C:b"
//#define MODPROBE_COMPLEMENTARY "q-v:v-q:l--acr:a--lr:r--al"
enum {
    OPT_INSERT_ALL   = (INSMOD_OPT_UNUSED << 0), /* a */
    //OPT_DUMP_ONLY  = (INSMOD_OPT_UNUSED << x), /* c */
    //OPT_DIRNAME    = (INSMOD_OPT_UNUSED << x), /* d */
    OPT_LIST_ONLY    = (INSMOD_OPT_UNUSED << 1), /* l */
    //OPT_SHOW_ONLY  = (INSMOD_OPT_UNUSED << x), /* n */
    OPT_REMOVE       = (INSMOD_OPT_UNUSED << 2), /* r */
    //OPT_RESTRICT   = (INSMOD_OPT_UNUSED << x), /* t */
    //OPT_VERONLY    = (INSMOD_OPT_UNUSED << x), /* V */
    //OPT_CONFIGFILE = (INSMOD_OPT_UNUSED << x), /* C */
    OPT_SHOW_DEPS    = (INSMOD_OPT_UNUSED << 3), /* D */
    OPT_BLACKLIST    = (INSMOD_OPT_UNUSED << 4) * ENABLE_FEATURE_MODPROBE_BLACKLIST,
};
#if ENABLE_LONG_OPTS
static const char modprobe_longopts[] ALIGN1 =
    /* nobody asked for long opts (yet) */
    // "all\0"          No_argument "a"
    // "list\0"         No_argument "l"
    // "remove\0"       No_argument "r"
    // "quiet\0"        No_argument "q"
    // "verbose\0"      No_argument "v"
    // "syslog\0"       No_argument "s"
    /* module-init-tools 3.11.1 has only long opt --show-depends
     * but no short -D, we provide long opt for scripts which
     * were written for 3.11.1: */
    "show-depends\0"     No_argument "D"
    // "use-blacklist\0" No_argument "b"
    ;
#endif

#define MODULE_FLAG_LOADED              0x0001
#define MODULE_FLAG_NEED_DEPS           0x0002
/* "was seen in modules.dep": */
#define MODULE_FLAG_FOUND_IN_MODDEP     0x0004
#define MODULE_FLAG_BLACKLISTED         0x0008

struct globals {
    llist_t *probes; /* MEs of module(s) requested on cmdline */
    char *cmdline_mopts; /* module options from cmdline */
    int num_unresolved_deps;
    /* bool. "Did we have 'symbol:FOO' requested on cmdline?" */
    smallint need_symbols;
    struct utsname uts;
    module_db db;
} FIX_ALIASING;
#define G (*ptr_to_globals)
#define INIT_G() do { \
    SET_PTR_TO_GLOBALS(xzalloc(sizeof(G))); \
} while (0)


static int read_config(const char *path);

static char *gather_options_str(char *opts, const char *append)
{
    /* Speed-optimized. We call gather_options_str many times. */
    if (append) {
        if (opts == NULL) {
            opts = xstrdup(append);
        } else {
            int optlen = strlen(opts);
            opts = xrealloc(opts, optlen + strlen(append) + 2);
            sprintf(opts + optlen, " %s", append);
        }
    }
    return opts;
}

static struct module_entry *get_or_add_modentry(const char *module)
{
    return moddb_get_or_create(&G.db, module);
}

static void add_probe(const char *name)
{
    struct module_entry *m;

    m = get_or_add_modentry(name);
    if (!(option_mask32 & (OPT_REMOVE | OPT_SHOW_DEPS))
     && (m->flags & MODULE_FLAG_LOADED)
    ) {
        DBG("skipping %s, it is already loaded", name);
        return;
    }

    DBG("queuing %s", name);
    m->probed_name = name;
    m->flags |= MODULE_FLAG_NEED_DEPS;
    llist_add_to_end(&G.probes, m);
    G.num_unresolved_deps++;
    if (ENABLE_FEATURE_MODUTILS_SYMBOLS
     && is_prefixed_with(m->modname, "symbol:")
    ) {
        G.need_symbols = 1;
    }
}

static int FAST_FUNC config_file_action(const char *filename,
                    struct stat *statbuf UNUSED_PARAM,
                    void *userdata UNUSED_PARAM,
                    int depth)
{
    char *tokens[3];
    parser_t *p;
    struct module_entry *m;
    int rc = TRUE;
    const char *base, *ext;

    /* Skip files that begin with a "." */
    base = bb_basename(filename);
    if (base[0] == '.')
        goto error;

    /* In dir recursion, skip files that do not end with a ".conf"
     * depth==0: read_config("modules.{symbols,alias}") must work,
     * "include FILE_NOT_ENDING_IN_CONF" must work too.
     */
    if (depth != 0) {
        ext = strrchr(base, '.');
        if (ext == NULL || strcmp(ext + 1, "conf"))
            goto error;
    }

    p = config_open2(filename, fopen_for_read);
    if (p == NULL) {
        rc = FALSE;
        goto error;
    }

    while (config_read(p, tokens, 3, 2, "# \t", PARSE_NORMAL)) {
//Use index_in_strings?
        if (strcmp(tokens[0], "alias") == 0) {
            /* alias <wildcard> <modulename> */
            llist_t *l;
            char wildcard[MODULE_NAME_LEN];
            char *rmod;

            if (tokens[2] == NULL)
                continue;
            filename2modname(tokens[1], wildcard);

            for (l = G.probes; l; l = l->link) {
                m = (struct module_entry *) l->data;
                if (fnmatch(wildcard, m->modname, 0) != 0)
                    continue;
                rmod = filename2modname(tokens[2], NULL);
                llist_add_to(&m->realnames, rmod);

                if (m->flags & MODULE_FLAG_NEED_DEPS) {
                    m->flags &= ~MODULE_FLAG_NEED_DEPS;
                    G.num_unresolved_deps--;
                }

                m = get_or_add_modentry(rmod);
                if (!(m->flags & MODULE_FLAG_NEED_DEPS)) {
                    m->flags |= MODULE_FLAG_NEED_DEPS;
                    G.num_unresolved_deps++;
                }
            }
        } else if (strcmp(tokens[0], "options") == 0) {
            /* options <modulename> <option...> */
            if (tokens[2] == NULL)
                continue;
            m = get_or_add_modentry(tokens[1]);
            m->options = gather_options_str(m->options, tokens[2]);
        } else if (strcmp(tokens[0], "include") == 0) {
            /* include <filename>/<dirname> (yes, directories also must work) */
            read_config(tokens[1]);
        } else if (ENABLE_FEATURE_MODPROBE_BLACKLIST
         && strcmp(tokens[0], "blacklist") == 0
        ) {
            /* blacklist <modulename> */
            get_or_add_modentry(tokens[1])->flags |= MODULE_FLAG_BLACKLISTED;
        }
    }
    config_close(p);
 error:
    return rc;
}

static int read_config(const char *path)
{
    return recursive_action(path, ACTION_RECURSE | ACTION_QUIET,
                config_file_action, NULL, NULL,
                /*depth:*/ 0);
}

static const char *humanly_readable_name(struct module_entry *m)
{
    /* probed_name may be NULL. modname always exists. */
    return m->probed_name ? m->probed_name : m->modname;
}

/* Like strsep(&stringp, "\n\t ") but quoted text goes to single token
 * even if it contains whitespace.
 */
static char *strsep_quotes(char **stringp)
{
    char *s, *start = *stringp;

    if (!start)
        return NULL;

    for (s = start; ; s++) {
        switch (*s) {
        case '"':
            s = strchrnul(s + 1, '"'); /* find trailing quote */
            if (*s != '\0')
                s++; /* skip trailing quote */
            /* fall through */
        case '\0':
        case '\n':
        case '\t':
        case ' ':
            if (*s != '\0') {
                *s = '\0';
                *stringp = s + 1;
            } else {
                *stringp = NULL;
            }
            return start;
        }
    }
}

static char *parse_and_add_kcmdline_module_options(char *options, const char *modulename)
{
    char *kcmdline_buf;
    char *kcmdline;
    char *kptr;

    kcmdline_buf = xmalloc_open_read_close("/proc/cmdline", NULL);
    if (!kcmdline_buf)
        return options;

    kcmdline = kcmdline_buf;
    while ((kptr = strsep_quotes(&kcmdline)) != NULL) {
        char *after_modulename = is_prefixed_with(kptr, modulename);
        if (!after_modulename || *after_modulename != '.')
            continue;
        /* It is "modulename.xxxx" */
        kptr = after_modulename + 1;
        if (strchr(kptr, '=') != NULL) {
            /* It is "modulename.opt=[val]" */
            options = gather_options_str(options, kptr);
        }
    }
    free(kcmdline_buf);

    return options;
}

/* Return: similar to bb_init_module:
 * 0 on success,
 * -errno on open/read error,
 * errno on init_module() error
 */
/* NB: INSMOD_OPT_SILENT bit suppresses ONLY non-existent modules,
 * not deleted ones (those are still listed in modules.dep).
 * module-init-tools version 3.4:
 * # modprobe bogus
 * FATAL: Module bogus not found. [exitcode 1]
 * # modprobe -q bogus            [silent, exitcode still 1]
 * but:
 * # rm kernel/drivers/net/dummy.ko
 * # modprobe -q dummy
 * FATAL: Could not open '/lib/modules/xxx/kernel/drivers/net/dummy.ko': No such file or directory
 * [exitcode 1]
 */
static int do_modprobe(struct module_entry *m)
{
    int rc, first;

    if (!(m->flags & MODULE_FLAG_FOUND_IN_MODDEP)) {
        if (!(option_mask32 & INSMOD_OPT_SILENT))
            bb_error_msg("module %s not found in modules.dep",
                humanly_readable_name(m));
        return -ENOENT;
    }
    DBG("do_modprob'ing %s", m->modname);

    if (!(option_mask32 & OPT_REMOVE))
        m->deps = llist_rev(m->deps);

    if (0) {
        llist_t *l;
        for (l = m->deps; l; l = l->link)
            DBG("dep: %s", l->data);
    }

    first = 1;
    rc = 0;
    while (m->deps) {
        struct module_entry *m2;
        char *fn, *options;

        rc = 0;
        fn = llist_pop(&m->deps); /* we leak it */
        m2 = get_or_add_modentry(bb_get_last_path_component_nostrip(fn));

        if (option_mask32 & OPT_REMOVE) {
            /* modprobe -r */
            if (m2->flags & MODULE_FLAG_LOADED) {
                rc = bb_delete_module(m2->modname, O_EXCL);
                if (rc) {
                    if (first) {
                        bb_perror_msg("can't unload module '%s'",
                            humanly_readable_name(m2));
                        break;
                    }
                } else {
                    m2->flags &= ~MODULE_FLAG_LOADED;
                }
            }
            /* do not error out if *deps* fail to unload */
            first = 0;
            continue;
        }

        options = m2->options;
        m2->options = NULL;
        options = parse_and_add_kcmdline_module_options(options, m2->modname);
        if (m == m2)
            options = gather_options_str(options, G.cmdline_mopts);

        if (option_mask32 & OPT_SHOW_DEPS) {
            printf(options ? "insmod %s/%s/%s %s\n"
                    : "insmod %s/%s/%s\n",
                CONFIG_DEFAULT_MODULES_DIR, G.uts.release, fn,
                options);
            free(options);
            continue;
        }

        if (m2->flags & MODULE_FLAG_LOADED) {
            DBG("%s is already loaded, skipping", fn);
            free(options);
            continue;
        }

        rc = bb_init_module(fn, options);
        DBG("loaded %s '%s', rc:%d", fn, options, rc);
        if (rc == EEXIST)
            rc = 0;
        free(options);
        if (rc) {
            bb_error_msg("can't load module %s (%s): %s",
                humanly_readable_name(m2),
                fn,
                moderror(rc)
            );
            break;
        }
        m2->flags |= MODULE_FLAG_LOADED;
    }

    return rc;
}

static void load_modules_dep(void)
{
    struct module_entry *m;
    char *colon, *tokens[2];
    parser_t *p;

    /* Modprobe does not work at all without modules.dep,
     * even if the full module name is given. Returning error here
     * was making us later confuse user with this message:
     * "module /full/path/to/existing/file/module.ko not found".
     * It's better to die immediately, with good message.
     * xfopen_for_read provides that. */
    p = config_open2(CONFIG_DEFAULT_DEPMOD_FILE, xfopen_for_read);

    while (G.num_unresolved_deps
     && config_read(p, tokens, 2, 1, "# \t", PARSE_NORMAL)
    ) {
        colon = last_char_is(tokens[0], ':');
        if (colon == NULL)
            continue;
        *colon = '\0';

        m = moddb_get(&G.db, bb_get_last_path_component_nostrip(tokens[0]));
        if (m == NULL)
            continue;

        /* Optimization... */
        if ((m->flags & MODULE_FLAG_LOADED)
         && !(option_mask32 & (OPT_REMOVE | OPT_SHOW_DEPS))
        ) {
            DBG("skip deps of %s, it's already loaded", tokens[0]);
            continue;
        }

        m->flags |= MODULE_FLAG_FOUND_IN_MODDEP;
        if ((m->flags & MODULE_FLAG_NEED_DEPS) && (m->deps == NULL)) {
            G.num_unresolved_deps--;
            llist_add_to(&m->deps, xstrdup(tokens[0]));
            if (tokens[1])
                string_to_llist(tokens[1], &m->deps, " \t");
        } else
            DBG("skipping dep line");
    }
    config_close(p);
}

int modprobe_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int modprobe_main(int argc UNUSED_PARAM, char **argv)
{
    int rc;
    unsigned opt;
    struct module_entry *me;

    INIT_G();

    IF_LONG_OPTS(applet_long_options = modprobe_longopts;)
    opt_complementary = MODPROBE_COMPLEMENTARY;
    opt = getopt32(argv, INSMOD_OPTS MODPROBE_OPTS INSMOD_ARGS);
    argv += optind;

    /* Goto modules location */
    xchdir(CONFIG_DEFAULT_MODULES_DIR);
    uname(&G.uts);
    xchdir(G.uts.release);

    if (opt & OPT_LIST_ONLY) {
        int i;
        char *colon, *tokens[2];
        parser_t *p = config_open2(CONFIG_DEFAULT_DEPMOD_FILE, xfopen_for_read);

        for (i = 0; argv[i]; i++)
            replace(argv[i], '-', '_');

        while (config_read(p, tokens, 2, 1, "# \t", PARSE_NORMAL)) {
            colon = last_char_is(tokens[0], ':');
            if (!colon)
                continue;
            *colon = '\0';
            if (!argv[0])
                puts(tokens[0]);
            else {
                char name[MODULE_NAME_LEN];
                filename2modname(
                    bb_get_last_path_component_nostrip(tokens[0]),
                    name
                );
                for (i = 0; argv[i]; i++) {
                    if (fnmatch(argv[i], name, 0) == 0) {
                        puts(tokens[0]);
                    }
                }
            }
        }
        return EXIT_SUCCESS;
    }

    /* Yes, for some reason -l ignores -s... */
    if (opt & INSMOD_OPT_SYSLOG)
        logmode = LOGMODE_SYSLOG;

    if (!argv[0]) {
        if (opt & OPT_REMOVE) {
            /* "modprobe -r" (w/o params).
             * "If name is NULL, all unused modules marked
             * autoclean will be removed".
             */
            if (bb_delete_module(NULL, O_NONBLOCK | O_EXCL) != 0)
                bb_perror_nomsg_and_die();
        }
        return EXIT_SUCCESS;
    }

    /* Retrieve module names of already loaded modules */
    {
        char *s;
        parser_t *parser = config_open2("/proc/modules", fopen_for_read);
        while (config_read(parser, &s, 1, 1, "# \t", PARSE_NORMAL & ~PARSE_GREEDY))
            get_or_add_modentry(s)->flags |= MODULE_FLAG_LOADED;
        config_close(parser);
    }

    if (opt & (OPT_INSERT_ALL | OPT_REMOVE)) {
        /* Each argument is a module name */
        do {
            DBG("adding module %s", *argv);
            add_probe(*argv++);
        } while (*argv);
    } else {
        /* First argument is module name, rest are parameters */
        DBG("probing just module %s", *argv);
        add_probe(argv[0]);
        G.cmdline_mopts = parse_cmdline_module_options(argv, /*quote_spaces:*/ 1);
    }

    /* Happens if all requested modules are already loaded */
    if (G.probes == NULL)
        return EXIT_SUCCESS;

    read_config("/etc/modprobe.conf");
    read_config("/etc/modprobe.d");
    if (ENABLE_FEATURE_MODUTILS_SYMBOLS && G.need_symbols)
        read_config("modules.symbols");
    load_modules_dep();
    if (ENABLE_FEATURE_MODUTILS_ALIAS && G.num_unresolved_deps) {
        read_config("modules.alias");
        load_modules_dep();
    }

    rc = 0;
    while ((me = llist_pop(&G.probes)) != NULL) {
        if (me->realnames == NULL) {
            DBG("probing by module name");
            /* This is not an alias. Literal names are blacklisted
             * only if '-b' is given.
             */
            if (!(opt & OPT_BLACKLIST)
             || !(me->flags & MODULE_FLAG_BLACKLISTED)
            ) {
                rc |= do_modprobe(me);
            }
            continue;
        }

        /* Probe all real names for the alias */
        do {
            char *realname = llist_pop(&me->realnames);
            struct module_entry *m2;

            DBG("probing alias %s by realname %s", me->modname, realname);
            m2 = get_or_add_modentry(realname);
            if (!(m2->flags & MODULE_FLAG_BLACKLISTED)
             && (!(m2->flags & MODULE_FLAG_LOADED)
                || (opt & (OPT_REMOVE | OPT_SHOW_DEPS)))
            ) {
//TODO: we can pass "me" as 2nd param to do_modprobe,
//and make do_modprobe emit more meaningful error messages
//with alias name included, not just module name alias resolves to.
                rc |= do_modprobe(m2);
            }
            free(realname);
        } while (me->realnames != NULL);
    }

    if (ENABLE_FEATURE_CLEAN_UP)
        moddb_free(&G.db);

    return (rc != 0);
}