src/udev/udev-builtin-kmod.c

   1 /*
   2  * load kernel modules
   3  *
   4  * Copyright (C) 2011 Kay Sievers <kay.sievers@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 {
  38         struct kmod_list *list = NULL;
  39         struct kmod_list *l;
  40         int err;
  41
  42         err = kmod_module_new_from_lookup(ctx, alias, &list);
  43         if (err < 0)
  44                 return err;
  45
  46         if (list == NULL)
  47                 log_debug("no module matches '%s'\n", alias);
  48
  49         kmod_list_foreach(l, list) {
  50                 struct kmod_module *mod = kmod_module_get_module(l);
  51
  52                 err = kmod_module_probe_insert_module(mod, KMOD_PROBE_APPLY_BLACKLIST, NULL, NULL, NULL, NULL);
  53                 if (err == KMOD_PROBE_APPLY_BLACKLIST)
  54                         log_debug("module '%s' is blacklisted\n", kmod_module_get_name(mod));
  55                 else if (err == 0)
  56                         log_debug("inserted '%s'\n", kmod_module_get_name(mod));
  57                 else
  58                         log_debug("failed to insert '%s'\n", kmod_module_get_name(mod));
  59
  60                 kmod_module_unref(mod);
  61         }
  62
  63         kmod_module_unref_list(list);
  64         return err;
  65 }
  66
  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 {
  70         udev_main_log(data, priority, file, line, fn, format, args);
  71 }
  72
  73 /* needs to re-instantiate the context after a reload */
  74 static int builtin_kmod(struct udev_device *dev, int argc, char *argv[], bool test)
  75 {
  76         struct udev *udev = udev_device_get_udev(dev);
  77         int i;
  78
  79         if (!ctx) {
  80                 ctx = kmod_new(NULL, NULL);
  81                 if (!ctx)
  82                         return -ENOMEM;
  83
  84                 log_debug("load module index\n");
  85                 kmod_set_log_fn(ctx, udev_kmod_log, udev);
  86                 kmod_load_resources(ctx);
  87         }
  88
  89         if (argc < 3 || strcmp(argv[1], "load")) {
  90                 log_error("expect: %s load <module>\n", argv[0]);
  91                 return EXIT_FAILURE;
  92         }
  93
  94         for (i = 2; argv[i]; i++) {
  95                 log_debug("execute '%s' '%s'\n", argv[1], argv[i]);
  96                 load_module(udev, argv[i]);
  97         }
  98
  99         return EXIT_SUCCESS;
 100 }
 101
 102 /* called at udev startup */
 103 static int builtin_kmod_init(struct udev *udev)
 104 {
 105         if (ctx)
 106                 return 0;
 107
 108         ctx = kmod_new(NULL, NULL);
 109         if (!ctx)
 110                 return -ENOMEM;
 111
 112         log_debug("load module index\n");
 113         kmod_set_log_fn(ctx, udev_kmod_log, udev);
 114         kmod_load_resources(ctx);
 115         return 0;
 116 }
 117
 118 /* called on udev shutdown and reload request */
 119 static void builtin_kmod_exit(struct udev *udev)
 120 {
 121         log_debug("unload module index\n");
 122         ctx = kmod_unref(ctx);
 123 }
 124
 125 /* called every couple of seconds during event activity; 'true' if config has changed */
 126 static bool builtin_kmod_validate(struct udev *udev)
 127 {
 128         log_debug("validate module index\n");
 129         if (kmod_validate_resources(ctx) != KMOD_RESOURCES_OK)
 130                 return true;
 131         return false;
 132 }
 133
 134 const struct udev_builtin udev_builtin_kmod = {
 135         .name = "kmod",
 136         .cmd = builtin_kmod,
 137         .init = builtin_kmod_init,
 138         .exit = builtin_kmod_exit,
 139         .validate = builtin_kmod_validate,
 140         .help = "kernel module loader",
 141         .run_once = false,
 142 };