extensions/libxt_LED.c

   1 /*
   2  * libxt_LED.c - shared library add-on to iptables to add customized LED
   3  *               trigger support.
   4  *
   5  * (C) 2008 Adam Nielsen <a.nielsen@shikadi.net>
   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 version 2 as
   9  * published by the Free Software Foundation.
  10  *
  11  */
  12
  13 #include <stdio.h>
  14 #include <string.h>
  15 #include <stdlib.h>
  16 #include <getopt.h>
  17 #include <stddef.h>
  18
  19 #include <xtables.h>
  20
  21 #include <linux/netfilter/xt_LED.h>
  22
  23 static const struct option LED_opts[] = {
  24         {.name = "led-trigger-id",   .has_arg = true,  .val = 'i'},
  25         {.name = "led-delay",        .has_arg = true,  .val = 'd'},
  26         {.name = "led-always-blink", .has_arg = false, .val = 'a'},
  27         {.name = NULL},
  28 };
  29
  30 static void LED_help(void)
  31 {
  32         printf(
  33 "LED target options:\n"
  34 "--led-trigger-id name           suffix for led trigger name\n"
  35 "--led-delay ms                  leave the LED on for this number of\n"
  36 "                                milliseconds after triggering.\n"
  37 "--led-always-blink              blink on arriving packets, even if\n"
  38 "                                the LED is already on.\n"
  39         );
  40 }
  41
  42 static int LED_parse(int c, char **argv, int invert, unsigned int *flags,
  43                      const void *entry, struct xt_entry_target **target)
  44 {
  45         struct xt_led_info *led = (void *)(*target)->data;
  46
  47         switch (c) {
  48         case 'i':
  49                 xtables_param_act(XTF_NO_INVERT, "LED",
  50                         "--led-trigger-id", invert);
  51                 if (strlen("netfilter-") + strlen(optarg) > sizeof(led->id))
  52                         xtables_error(PARAMETER_PROBLEM,
  53                                 "--led-trigger-id must be 16 chars or less");
  54                 if (optarg[0] == '\0')
  55                         xtables_error(PARAMETER_PROBLEM,
  56                                 "--led-trigger-id cannot be blank");
  57
  58                 /* "netfilter-" + 16 char id == 26 == sizeof(led->id) */
  59                 strcpy(led->id, "netfilter-");
  60                 strcat(led->id, optarg);
  61                 *flags = 1;
  62                 return true;
  63
  64         case 'd':
  65                 xtables_param_act(XTF_NO_INVERT, "LED", "--led-delay", invert);
  66                 if (strncasecmp(optarg, "inf", 3) == 0)
  67                         led->delay = -1;
  68                 else
  69                         led->delay = strtoul(optarg, NULL, 0);
  70
  71                 return true;
  72
  73         case 'a':
  74                 if (!invert)
  75                         led->always_blink = 1;
  76                 return true;
  77         }
  78         return false;
  79 }
  80
  81 static void LED_final_check(unsigned int flags)
  82 {
  83         if (flags == 0)
  84                 xtables_error(PARAMETER_PROBLEM,
  85                         "--led-trigger-id must be specified");
  86 }
  87
  88 static void LED_print(const void *ip, const struct xt_entry_target *target,
  89                       int numeric)
  90 {
  91         const struct xt_led_info *led = (void *)target->data;
  92         const char *id = led->id + strlen("netfilter-"); /* trim off prefix */
  93
  94         printf("led-trigger-id:\"");
  95         /* Escape double quotes and backslashes in the ID */
  96         while (*id != '\0') {
  97                 if (*id == '"' || *id == '\\')
  98                         printf("\\");
  99                 printf("%c", *id++);
 100         }
 101         printf("\" ");
 102
 103         if (led->delay == -1)
 104                 printf("led-delay:inf ");
 105         else
 106                 printf("led-delay:%dms ", led->delay);
 107
 108         if (led->always_blink)
 109                 printf("led-always-blink ");
 110 }
 111
 112 static void LED_save(const void *ip, const struct xt_entry_target *target)
 113 {
 114         const struct xt_led_info *led = (void *)target->data;
 115         const char *id = led->id + strlen("netfilter-"); /* trim off prefix */
 116
 117         printf("--led-trigger-id \"");
 118         /* Escape double quotes and backslashes in the ID */
 119         while (*id != '\0') {
 120                 if (*id == '"' || *id == '\\')
 121                         printf("\\");
 122                 printf("%c", *id++);
 123         }
 124         printf("\" ");
 125
 126         /* Only print the delay if it's not zero (the default) */
 127         if (led->delay > 0)
 128                 printf("--led-delay %d ", led->delay);
 129         else if (led->delay == -1)
 130                 printf("--led-delay inf ");
 131
 132         /* Only print always_blink if it's not set to the default */
 133         if (led->always_blink)
 134                 printf("--led-always-blink ");
 135 }
 136
 137 static struct xtables_target led_tg_reg = {
 138         .version       = XTABLES_VERSION,
 139         .name          = "LED",
 140         .family        = PF_UNSPEC,
 141         .revision      = 0,
 142         .size          = XT_ALIGN(sizeof(struct xt_led_info)),
 143         .userspacesize = offsetof(struct xt_led_info, internal_data),
 144         .help          = LED_help,
 145         .parse         = LED_parse,
 146         .final_check   = LED_final_check,
 147         .extra_opts    = LED_opts,
 148         .print         = LED_print,
 149         .save          = LED_save,
 150 };
 151
 152 void _init(void)
 153 {
 154         xtables_register_target(&led_tg_reg);
 155 }