libxt_LED.c revision 73866357e4a7a0fdc1b293bf8863fee2bd56da9e 
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#include <stdbool.h>
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
23static 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	XT_GETOPT_TABLEEND,
28};
29
30static 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
42static 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
81static 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
88static 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
112static 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
137static 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
152void _init(void)
153{
154	xtables_register_target(&led_tg_reg);
155}
156