src/udev/udev-builtin-kmod.c

   1 /*
   2  * load kernel modules
   3  *
   4  * Copyright (C) 2011-2012 Kay Sievers <kay@vrfy.org>
   5  * Copyright (C) 2011 ProFUSION embedded systems
   6  *
   7  * This program is free software: you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License as published by
   9  * the Free Software Foundation, either version 2 of the License, or
  10  * (at your option) any later version.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License
  18  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  19  */
  20
  21 #include <stdio.h>
  22 #include <stdlib.h>
  23 #include <stdarg.h>
  24 #include <unistd.h>
  25 #include <string.h>
  26 #include <errno.h>
  27 #include <fcntl.h>
  28 #include <sys/stat.h>
  29 #include <sys/wait.h>
  30 #include <libkmod.h>
  31
  32 #include "udev.h"
  33
  34 static struct kmod_ctx *ctx;
  35
  36 static int load_module(struct udev *udev, const char *alias) {
  37         struct kmod_list *list = NULL;
  38         struct kmod_list *l;
  39         int err;
  40
  41         err = kmod_module_new_from_lookup(ctx, alias, &list);
  42         if (err < 0)
  43                 return err;
  44
  45         if (list == NULL)
  46                 log_debug("no module matches '%s'", alias);
  47
  48         kmod_list_foreach(l, list) {
  49                 struct kmod_module *mod = kmod_module_get_module(l);
  50
  51                 err = kmod_module_probe_insert_module(mod, KMOD_PROBE_APPLY_BLACKLIST, NULL, NULL, NULL, NULL);
  52                 if (err == KMOD_PROBE_APPLY_BLACKLIST)
  53                         log_debug("module '%s' is blacklisted", kmod_module_get_name(mod));
  54                 else if (err == 0)
  55                         log_debug("inserted '%s'", kmod_module_get_name(mod));
  56                 else
  57                         log_debug("failed to insert '%s'", kmod_module_get_name(mod));
  58
  59                 kmod_module_unref(mod);
  60         }
  61
  62         kmod_module_unref_list(list);
  63         return err;
  64 }
  65
  66 _printf_(6,0)
  67 static void udev_kmod_log(void *data, int priority, const char *file, int line,
  68                           const char *fn, const char *format, va_list args) {
  69         udev_main_log(data, priority, file, line, fn, format, args);
  70 }
  71
  72 static int builtin_kmod(struct udev_device *dev, int argc, char *argv[], bool test) {
  73         struct udev *udev = udev_device_get_udev(dev);
  74         int i;
  75
  76         if (!ctx)
  77                 return 0;
  78
  79         if (argc < 3 || !streq(argv[1], "load")) {
  80                 log_error("expect: %s load <module>", argv[0]);
  81                 return EXIT_FAILURE;
  82         }
  83
  84         for (i = 2; argv[i]; i++) {
  85                 log_debug("execute '%s' '%s'", argv[1], argv[i]);
  86                 load_module(udev, argv[i]);
  87         }
  88
  89         return EXIT_SUCCESS;
  90 }
  91
  92 /* called at udev startup and reload */
  93 static int builtin_kmod_init(struct udev *udev) {
  94         if (ctx)
  95                 return 0;
  96
  97         ctx = kmod_new(NULL, NULL);
  98         if (!ctx)
  99                 return -ENOMEM;
 100
 101         log_debug("load module index");
 102         kmod_set_log_fn(ctx, udev_kmod_log, udev);
 103         kmod_load_resources(ctx);
 104         return 0;
 105 }
 106
 107 /* called on udev shutdown and reload request */
 108 static void builtin_kmod_exit(struct udev *udev) {
 109         log_debug("unload module index");
 110         ctx = kmod_unref(ctx);
 111 }
 112
 113 /* called every couple of seconds during event activity; 'true' if config has changed */
 114 static bool builtin_kmod_validate(struct udev *udev) {
 115         log_debug("validate module index");
 116         if (!ctx)
 117                 return false;
 118         return (kmod_validate_resources(ctx) != KMOD_RESOURCES_OK);
 119 }
 120
 121 const struct udev_builtin udev_builtin_kmod = {
 122         .name = "kmod",
 123         .cmd = builtin_kmod,
 124         .init = builtin_kmod_init,
 125         .exit = builtin_kmod_exit,
 126         .validate = builtin_kmod_validate,
 127         .help = "kernel module loader",
 128         .run_once = false,
 129 };