src/udev/udev-builtin-kmod.c

   1 /* SPDX-License-Identifier: GPL-2.0+ */
   2 /*
   3  * load kernel modules
   4  *
   5  * Copyright © 2011 ProFUSION embedded systems
   6  */
   7
   8 #include <errno.h>
   9 #include <libkmod.h>
  10 #include <stdarg.h>
  11 #include <stdio.h>
  12 #include <stdlib.h>
  13
  14 #include "module-util.h"
  15 #include "string-util.h"
  16 #include "udev-builtin.h"
  17
  18 static struct kmod_ctx *ctx = NULL;
  19
  20 _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) {
  21         log_internalv(priority, 0, file, line, fn, format, args);
  22 }
  23
  24 static int builtin_kmod(sd_device *dev, int argc, char *argv[], bool test) {
  25         int i;
  26
  27         if (!ctx)
  28                 return 0;
  29
  30         if (argc < 3 || !streq(argv[1], "load")) {
  31                 log_error("%s: expected: load <module>", argv[0]);
  32                 return -EINVAL;
  33         }
  34
  35         for (i = 2; argv[i]; i++)
  36                 (void) module_load_and_warn(ctx, argv[i], false);
  37
  38         return 0;
  39 }
  40
  41 /* called at udev startup and reload */
  42 static int builtin_kmod_init(void) {
  43         if (ctx)
  44                 return 0;
  45
  46         ctx = kmod_new(NULL, NULL);
  47         if (!ctx)
  48                 return -ENOMEM;
  49
  50         log_debug("Load module index");
  51         kmod_set_log_fn(ctx, udev_kmod_log, NULL);
  52         kmod_load_resources(ctx);
  53         return 0;
  54 }
  55
  56 /* called on udev shutdown and reload request */
  57 static void builtin_kmod_exit(void) {
  58         log_debug("Unload module index");
  59         ctx = kmod_unref(ctx);
  60 }
  61
  62 /* called every couple of seconds during event activity; 'true' if config has changed */
  63 static bool builtin_kmod_validate(void) {
  64         log_debug("Validate module index");
  65         if (!ctx)
  66                 return false;
  67         return (kmod_validate_resources(ctx) != KMOD_RESOURCES_OK);
  68 }
  69
  70 const struct udev_builtin udev_builtin_kmod = {
  71         .name = "kmod",
  72         .cmd = builtin_kmod,
  73         .init = builtin_kmod_init,
  74         .exit = builtin_kmod_exit,
  75         .validate = builtin_kmod_validate,
  76         .help = "Kernel module loader",
  77         .run_once = false,
  78 };