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1/*
2 * xt_LED.c - netfilter target to make LEDs blink upon packet matches
3 *
4 * Copyright (C) 2008 Adam Nielsen <a.nielsen@shikadi.net>
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; version 2 of the License.
9 *
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
14 *
15 * You should have received a copy of the GNU General Public License
16 * along with this program; if not, write to the Free Software
17 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
18 * 02110-1301 USA.
19 *
20 */
21#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
22#include <linux/module.h>
23#include <linux/skbuff.h>
24#include <linux/netfilter/x_tables.h>
25#include <linux/slab.h>
26#include <linux/leds.h>
27#include <linux/mutex.h>
28
29#include <linux/netfilter/xt_LED.h>
30
31MODULE_LICENSE("GPL");
32MODULE_AUTHOR("Adam Nielsen <a.nielsen@shikadi.net>");
33MODULE_DESCRIPTION("Xtables: trigger LED devices on packet match");
34MODULE_ALIAS("ipt_LED");
35MODULE_ALIAS("ip6t_LED");
36
37static LIST_HEAD(xt_led_triggers);
38static DEFINE_MUTEX(xt_led_mutex);
39
40/*
41 * This is declared in here (the kernel module) only, to avoid having these
42 * dependencies in userspace code. This is what xt_led_info.internal_data
43 * points to.
44 */
45struct xt_led_info_internal {
46 struct list_head list;
47 int refcnt;
48 char *trigger_id;
49 struct led_trigger netfilter_led_trigger;
50 struct timer_list timer;
51};
52
53static unsigned int
54led_tg(struct sk_buff *skb, const struct xt_action_param *par)
55{
56 const struct xt_led_info *ledinfo = par->targinfo;
57 struct xt_led_info_internal *ledinternal = ledinfo->internal_data;
58
59 /*
60 * If "always blink" is enabled, and there's still some time until the
61 * LED will switch off, briefly switch it off now.
62 */
63 if ((ledinfo->delay > 0) && ledinfo->always_blink &&
64 timer_pending(&ledinternal->timer))
65 led_trigger_event(&ledinternal->netfilter_led_trigger, LED_OFF);
66
67 led_trigger_event(&ledinternal->netfilter_led_trigger, LED_FULL);
68
69 /* If there's a positive delay, start/update the timer */
70 if (ledinfo->delay > 0) {
71 mod_timer(&ledinternal->timer,
72 jiffies + msecs_to_jiffies(ledinfo->delay));
73
74 /* Otherwise if there was no delay given, blink as fast as possible */
75 } else if (ledinfo->delay == 0) {
76 led_trigger_event(&ledinternal->netfilter_led_trigger, LED_OFF);
77 }
78
79 /* else the delay is negative, which means switch on and stay on */
80
81 return XT_CONTINUE;
82}
83
84static void led_timeout_callback(unsigned long data)
85{
86 struct xt_led_info_internal *ledinternal = (struct xt_led_info_internal *)data;
87
88 led_trigger_event(&ledinternal->netfilter_led_trigger, LED_OFF);
89}
90
91static struct xt_led_info_internal *led_trigger_lookup(const char *name)
92{
93 struct xt_led_info_internal *ledinternal;
94
95 list_for_each_entry(ledinternal, &xt_led_triggers, list) {
96 if (!strcmp(name, ledinternal->netfilter_led_trigger.name)) {
97 return ledinternal;
98 }
99 }
100 return NULL;
101}
102
103static int led_tg_check(const struct xt_tgchk_param *par)
104{
105 struct xt_led_info *ledinfo = par->targinfo;
106 struct xt_led_info_internal *ledinternal;
107 int err;
108
109 if (ledinfo->id[0] == '\0') {
110 pr_info("No 'id' parameter given.\n");
111 return -EINVAL;
112 }
113
114 mutex_lock(&xt_led_mutex);
115
116 ledinternal = led_trigger_lookup(ledinfo->id);
117 if (ledinternal) {
118 ledinternal->refcnt++;
119 goto out;
120 }
121
122 err = -ENOMEM;
123 ledinternal = kzalloc(sizeof(struct xt_led_info_internal), GFP_KERNEL);
124 if (!ledinternal)
125 goto exit_mutex_only;
126
127 ledinternal->trigger_id = kstrdup(ledinfo->id, GFP_KERNEL);
128 if (!ledinternal->trigger_id)
129 goto exit_internal_alloc;
130
131 ledinternal->refcnt = 1;
132 ledinternal->netfilter_led_trigger.name = ledinternal->trigger_id;
133
134 err = led_trigger_register(&ledinternal->netfilter_led_trigger);
135 if (err) {
136 pr_warning("led_trigger_register() failed\n");
137 if (err == -EEXIST)
138 pr_warning("Trigger name is already in use.\n");
139 goto exit_alloc;
140 }
141
142 /* See if we need to set up a timer */
143 if (ledinfo->delay > 0)
144 setup_timer(&ledinternal->timer, led_timeout_callback,
145 (unsigned long)ledinternal);
146
147 list_add_tail(&ledinternal->list, &xt_led_triggers);
148
149out:
150 mutex_unlock(&xt_led_mutex);
151
152 ledinfo->internal_data = ledinternal;
153
154 return 0;
155
156exit_alloc:
157 kfree(ledinternal->trigger_id);
158
159exit_internal_alloc:
160 kfree(ledinternal);
161
162exit_mutex_only:
163 mutex_unlock(&xt_led_mutex);
164
165 return err;
166}
167
168static void led_tg_destroy(const struct xt_tgdtor_param *par)
169{
170 const struct xt_led_info *ledinfo = par->targinfo;
171 struct xt_led_info_internal *ledinternal = ledinfo->internal_data;
172
173 mutex_lock(&xt_led_mutex);
174
175 if (--ledinternal->refcnt) {
176 mutex_unlock(&xt_led_mutex);
177 return;
178 }
179
180 list_del(&ledinternal->list);
181
182 if (ledinfo->delay > 0)
183 del_timer_sync(&ledinternal->timer);
184
185 led_trigger_unregister(&ledinternal->netfilter_led_trigger);
186
187 mutex_unlock(&xt_led_mutex);
188
189 kfree(ledinternal->trigger_id);
190 kfree(ledinternal);
191}
192
193static struct xt_target led_tg_reg __read_mostly = {
194 .name = "LED",
195 .revision = 0,
196 .family = NFPROTO_UNSPEC,
197 .target = led_tg,
198 .targetsize = sizeof(struct xt_led_info),
199 .checkentry = led_tg_check,
200 .destroy = led_tg_destroy,
201 .me = THIS_MODULE,
202};
203
204static int __init led_tg_init(void)
205{
206 return xt_register_target(&led_tg_reg);
207}
208
209static void __exit led_tg_exit(void)
210{
211 xt_unregister_target(&led_tg_reg);
212}
213
214module_init(led_tg_init);
215module_exit(led_tg_exit);
1/*
2 * xt_LED.c - netfilter target to make LEDs blink upon packet matches
3 *
4 * Copyright (C) 2008 Adam Nielsen <a.nielsen@shikadi.net>
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; version 2 of the License.
9 *
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
14 *
15 * You should have received a copy of the GNU General Public License
16 * along with this program; if not, write to the Free Software
17 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
18 * 02110-1301 USA.
19 *
20 */
21#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
22#include <linux/module.h>
23#include <linux/skbuff.h>
24#include <linux/netfilter/x_tables.h>
25#include <linux/slab.h>
26#include <linux/leds.h>
27#include <linux/mutex.h>
28
29#include <linux/netfilter/xt_LED.h>
30
31MODULE_LICENSE("GPL");
32MODULE_AUTHOR("Adam Nielsen <a.nielsen@shikadi.net>");
33MODULE_DESCRIPTION("Xtables: trigger LED devices on packet match");
34MODULE_ALIAS("ipt_LED");
35MODULE_ALIAS("ip6t_LED");
36
37static LIST_HEAD(xt_led_triggers);
38static DEFINE_MUTEX(xt_led_mutex);
39
40/*
41 * This is declared in here (the kernel module) only, to avoid having these
42 * dependencies in userspace code. This is what xt_led_info.internal_data
43 * points to.
44 */
45struct xt_led_info_internal {
46 struct list_head list;
47 int refcnt;
48 char *trigger_id;
49 struct led_trigger netfilter_led_trigger;
50 struct timer_list timer;
51};
52
53#define XT_LED_BLINK_DELAY 50 /* ms */
54
55static unsigned int
56led_tg(struct sk_buff *skb, const struct xt_action_param *par)
57{
58 const struct xt_led_info *ledinfo = par->targinfo;
59 struct xt_led_info_internal *ledinternal = ledinfo->internal_data;
60 unsigned long led_delay = XT_LED_BLINK_DELAY;
61
62 /*
63 * If "always blink" is enabled, and there's still some time until the
64 * LED will switch off, briefly switch it off now.
65 */
66 if ((ledinfo->delay > 0) && ledinfo->always_blink &&
67 timer_pending(&ledinternal->timer))
68 led_trigger_blink_oneshot(&ledinternal->netfilter_led_trigger,
69 &led_delay, &led_delay, 1);
70 else
71 led_trigger_event(&ledinternal->netfilter_led_trigger, LED_FULL);
72
73 /* If there's a positive delay, start/update the timer */
74 if (ledinfo->delay > 0) {
75 mod_timer(&ledinternal->timer,
76 jiffies + msecs_to_jiffies(ledinfo->delay));
77
78 /* Otherwise if there was no delay given, blink as fast as possible */
79 } else if (ledinfo->delay == 0) {
80 led_trigger_event(&ledinternal->netfilter_led_trigger, LED_OFF);
81 }
82
83 /* else the delay is negative, which means switch on and stay on */
84
85 return XT_CONTINUE;
86}
87
88static void led_timeout_callback(unsigned long data)
89{
90 struct xt_led_info_internal *ledinternal = (struct xt_led_info_internal *)data;
91
92 led_trigger_event(&ledinternal->netfilter_led_trigger, LED_OFF);
93}
94
95static struct xt_led_info_internal *led_trigger_lookup(const char *name)
96{
97 struct xt_led_info_internal *ledinternal;
98
99 list_for_each_entry(ledinternal, &xt_led_triggers, list) {
100 if (!strcmp(name, ledinternal->netfilter_led_trigger.name)) {
101 return ledinternal;
102 }
103 }
104 return NULL;
105}
106
107static int led_tg_check(const struct xt_tgchk_param *par)
108{
109 struct xt_led_info *ledinfo = par->targinfo;
110 struct xt_led_info_internal *ledinternal;
111 int err;
112
113 if (ledinfo->id[0] == '\0') {
114 pr_info("No 'id' parameter given.\n");
115 return -EINVAL;
116 }
117
118 mutex_lock(&xt_led_mutex);
119
120 ledinternal = led_trigger_lookup(ledinfo->id);
121 if (ledinternal) {
122 ledinternal->refcnt++;
123 goto out;
124 }
125
126 err = -ENOMEM;
127 ledinternal = kzalloc(sizeof(struct xt_led_info_internal), GFP_KERNEL);
128 if (!ledinternal)
129 goto exit_mutex_only;
130
131 ledinternal->trigger_id = kstrdup(ledinfo->id, GFP_KERNEL);
132 if (!ledinternal->trigger_id)
133 goto exit_internal_alloc;
134
135 ledinternal->refcnt = 1;
136 ledinternal->netfilter_led_trigger.name = ledinternal->trigger_id;
137
138 err = led_trigger_register(&ledinternal->netfilter_led_trigger);
139 if (err) {
140 pr_err("Trigger name is already in use.\n");
141 goto exit_alloc;
142 }
143
144 /* See if we need to set up a timer */
145 if (ledinfo->delay > 0)
146 setup_timer(&ledinternal->timer, led_timeout_callback,
147 (unsigned long)ledinternal);
148
149 list_add_tail(&ledinternal->list, &xt_led_triggers);
150
151out:
152 mutex_unlock(&xt_led_mutex);
153
154 ledinfo->internal_data = ledinternal;
155
156 return 0;
157
158exit_alloc:
159 kfree(ledinternal->trigger_id);
160
161exit_internal_alloc:
162 kfree(ledinternal);
163
164exit_mutex_only:
165 mutex_unlock(&xt_led_mutex);
166
167 return err;
168}
169
170static void led_tg_destroy(const struct xt_tgdtor_param *par)
171{
172 const struct xt_led_info *ledinfo = par->targinfo;
173 struct xt_led_info_internal *ledinternal = ledinfo->internal_data;
174
175 mutex_lock(&xt_led_mutex);
176
177 if (--ledinternal->refcnt) {
178 mutex_unlock(&xt_led_mutex);
179 return;
180 }
181
182 list_del(&ledinternal->list);
183
184 if (ledinfo->delay > 0)
185 del_timer_sync(&ledinternal->timer);
186
187 led_trigger_unregister(&ledinternal->netfilter_led_trigger);
188
189 mutex_unlock(&xt_led_mutex);
190
191 kfree(ledinternal->trigger_id);
192 kfree(ledinternal);
193}
194
195static struct xt_target led_tg_reg __read_mostly = {
196 .name = "LED",
197 .revision = 0,
198 .family = NFPROTO_UNSPEC,
199 .target = led_tg,
200 .targetsize = sizeof(struct xt_led_info),
201 .checkentry = led_tg_check,
202 .destroy = led_tg_destroy,
203 .me = THIS_MODULE,
204};
205
206static int __init led_tg_init(void)
207{
208 return xt_register_target(&led_tg_reg);
209}
210
211static void __exit led_tg_exit(void)
212{
213 xt_unregister_target(&led_tg_reg);
214}
215
216module_init(led_tg_init);
217module_exit(led_tg_exit);