src/udev/udev-builtin-kmod.c

   1 /* SPDX-License-Identifier: GPL-2.0+ */
   2 /*
   3  * load kernel modules
   4  *
   5  * Copyright (C) 2011-2012 Kay Sievers <kay@vrfy.org>
   6  * Copyright (C) 2011 ProFUSION embedded systems
   7  *
   8  * This program is free software: you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License as published by
  10  * the Free Software Foundation, either version 2 of the License, or
  11  * (at your option) any later version.
  12  *
  13  * This program is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  * GNU General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU General Public License
  19  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  20  */
  21
  22 #include <errno.h>
  23 #include <libkmod.h>
  24 #include <stdarg.h>
  25 #include <stdio.h>
  26 #include <stdlib.h>
  27
  28 #include "module-util.h"
  29 #include "string-util.h"
  30 #include "udev.h"
  31
  32 static struct kmod_ctx *ctx = NULL;
  33
  34 static int load_module(struct udev *udev, const char *alias) {
  35         _cleanup_(kmod_module_unref_listp) struct kmod_list *list = NULL;
  36         struct kmod_list *l;
  37         int err;
  38
  39         err = kmod_module_new_from_lookup(ctx, alias, &list);
  40         if (err < 0)
  41                 return err;
  42
  43         if (list == NULL)
  44                 log_debug("No module matches '%s'", alias);
  45
  46         kmod_list_foreach(l, list) {
  47                 _cleanup_(kmod_module_unrefp) struct kmod_module *mod = NULL;
  48
  49                 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
  60         return err;
  61 }
  62
  63 _printf_(6,0) static void udev_kmod_log(void *data, int priority, const char *file, int line, const char *fn, const char *format, va_list args) {
  64         log_internalv(priority, 0, file, line, fn, format, args);
  65 }
  66
  67 static int builtin_kmod(struct udev_device *dev, int argc, char *argv[], bool test) {
  68         struct udev *udev = udev_device_get_udev(dev);
  69         int i;
  70
  71         if (!ctx)
  72                 return 0;
  73
  74         if (argc < 3 || !streq(argv[1], "load")) {
  75                 log_error("expect: %s load <module>", argv[0]);
  76                 return EXIT_FAILURE;
  77         }
  78
  79         for (i = 2; argv[i]; i++) {
  80                 log_debug("Execute '%s' '%s'", argv[1], argv[i]);
  81                 load_module(udev, argv[i]);
  82         }
  83
  84         return EXIT_SUCCESS;
  85 }
  86
  87 /* called at udev startup and reload */
  88 static int builtin_kmod_init(struct udev *udev) {
  89         if (ctx)
  90                 return 0;
  91
  92         ctx = kmod_new(NULL, NULL);
  93         if (!ctx)
  94                 return -ENOMEM;
  95
  96         log_debug("Load module index");
  97         kmod_set_log_fn(ctx, udev_kmod_log, udev);
  98         kmod_load_resources(ctx);
  99         return 0;
 100 }
 101
 102 /* called on udev shutdown and reload request */
 103 static void builtin_kmod_exit(struct udev *udev) {
 104         log_debug("Unload module index");
 105         ctx = kmod_unref(ctx);
 106 }
 107
 108 /* called every couple of seconds during event activity; 'true' if config has changed */
 109 static bool builtin_kmod_validate(struct udev *udev) {
 110         log_debug("Validate module index");
 111         if (!ctx)
 112                 return false;
 113         return (kmod_validate_resources(ctx) != KMOD_RESOURCES_OK);
 114 }
 115
 116 const struct udev_builtin udev_builtin_kmod = {
 117         .name = "kmod",
 118         .cmd = builtin_kmod,
 119         .init = builtin_kmod_init,
 120         .exit = builtin_kmod_exit,
 121         .validate = builtin_kmod_validate,
 122         .help = "Kernel module loader",
 123         .run_once = false,
 124 };