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      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 (at) 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 #include <stdio.h>
     13 #include <string.h>
     14 #include <stdlib.h>
     15 #include <xtables.h>
     16 #include <linux/netfilter/xt_LED.h>
     17 
     18 enum {
     19 	O_LED_TRIGGER_ID = 0,
     20 	O_LED_DELAY,
     21 	O_LED_ALWAYS_BLINK,
     22 };
     23 
     24 #define s struct xt_led_info
     25 static const struct xt_option_entry LED_opts[] = {
     26 	{.name = "led-trigger-id", .id = O_LED_TRIGGER_ID,
     27 	 .flags = XTOPT_MAND, .type = XTTYPE_STRING, .min = 0,
     28 	 .max = sizeof(((struct xt_led_info *)NULL)->id) -
     29 	        sizeof("netfilter-")},
     30 	{.name = "led-delay", .id = O_LED_DELAY, .type = XTTYPE_STRING},
     31 	{.name = "led-always-blink", .id = O_LED_ALWAYS_BLINK,
     32 	 .type = XTTYPE_NONE},
     33 	XTOPT_TABLEEND,
     34 };
     35 #undef s
     36 
     37 static void LED_help(void)
     38 {
     39 	printf(
     40 "LED target options:\n"
     41 "--led-trigger-id name           suffix for led trigger name\n"
     42 "--led-delay ms                  leave the LED on for this number of\n"
     43 "                                milliseconds after triggering.\n"
     44 "--led-always-blink              blink on arriving packets, even if\n"
     45 "                                the LED is already on.\n"
     46 	);
     47 }
     48 
     49 static void LED_parse(struct xt_option_call *cb)
     50 {
     51 	struct xt_led_info *led = cb->data;
     52 
     53 	xtables_option_parse(cb);
     54 	switch (cb->entry->id) {
     55 	case O_LED_TRIGGER_ID:
     56 		strcpy(led->id, "netfilter-");
     57 		strcat(led->id, cb->arg);
     58 		break;
     59 	case O_LED_DELAY:
     60 		if (strncasecmp(cb->arg, "inf", 3) == 0)
     61 			led->delay = -1;
     62 		else if (!xtables_strtoui(cb->arg, NULL, &led->delay, 0, UINT32_MAX))
     63 			xtables_error(PARAMETER_PROBLEM,
     64 				"Delay value must be within range 0..%u",
     65 				UINT32_MAX);
     66 		break;
     67 	case O_LED_ALWAYS_BLINK:
     68 		led->always_blink = 1;
     69 		break;
     70 	}
     71 }
     72 
     73 static void LED_print(const void *ip, const struct xt_entry_target *target,
     74 		      int numeric)
     75 {
     76 	const struct xt_led_info *led = (void *)target->data;
     77 	const char *id = led->id + strlen("netfilter-"); /* trim off prefix */
     78 
     79 	printf(" led-trigger-id:\"");
     80 	/* Escape double quotes and backslashes in the ID */
     81 	while (*id != '\0') {
     82 		if (*id == '"' || *id == '\\')
     83 			printf("\\");
     84 		printf("%c", *id++);
     85 	}
     86 	printf("\"");
     87 
     88 	if (led->delay == -1)
     89 		printf(" led-delay:inf");
     90 	else
     91 		printf(" led-delay:%dms", led->delay);
     92 
     93 	if (led->always_blink)
     94 		printf(" led-always-blink");
     95 }
     96 
     97 static void LED_save(const void *ip, const struct xt_entry_target *target)
     98 {
     99 	const struct xt_led_info *led = (void *)target->data;
    100 	const char *id = led->id + strlen("netfilter-"); /* trim off prefix */
    101 
    102 	printf(" --led-trigger-id \"");
    103 	/* Escape double quotes and backslashes in the ID */
    104 	while (*id != '\0') {
    105 		if (*id == '"' || *id == '\\')
    106 			printf("\\");
    107 		printf("%c", *id++);
    108 	}
    109 	printf("\"");
    110 
    111 	/* Only print the delay if it's not zero (the default) */
    112 	if (led->delay > 0)
    113 		printf(" --led-delay %d", led->delay);
    114 	else if (led->delay == -1)
    115 		printf(" --led-delay inf");
    116 
    117 	/* Only print always_blink if it's not set to the default */
    118 	if (led->always_blink)
    119 		printf(" --led-always-blink");
    120 }
    121 
    122 static struct xtables_target led_tg_reg = {
    123 	.version       = XTABLES_VERSION,
    124 	.name          = "LED",
    125 	.family        = PF_UNSPEC,
    126 	.revision      = 0,
    127 	.size          = XT_ALIGN(sizeof(struct xt_led_info)),
    128 	.userspacesize = offsetof(struct xt_led_info, internal_data),
    129 	.help          = LED_help,
    130 	.print         = LED_print,
    131 	.save          = LED_save,
    132 	.x6_parse      = LED_parse,
    133 	.x6_options    = LED_opts,
    134 };
    135 
    136 void _init(void)
    137 {
    138 	xtables_register_target(&led_tg_reg);
    139 }
    140