]>
Commit | Line | Data |
---|---|---|
268cb38e AN |
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 | */ | |
8bee4bad | 21 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
268cb38e AN |
22 | #include <linux/module.h> |
23 | #include <linux/skbuff.h> | |
24 | #include <linux/netfilter/x_tables.h> | |
5a0e3ad6 | 25 | #include <linux/slab.h> |
268cb38e AN |
26 | #include <linux/leds.h> |
27 | #include <linux/mutex.h> | |
28 | ||
29 | #include <linux/netfilter/xt_LED.h> | |
30 | ||
31 | MODULE_LICENSE("GPL"); | |
32 | MODULE_AUTHOR("Adam Nielsen <a.nielsen@shikadi.net>"); | |
33 | MODULE_DESCRIPTION("Xtables: trigger LED devices on packet match"); | |
f1e231a3 JE |
34 | MODULE_ALIAS("ipt_LED"); |
35 | MODULE_ALIAS("ip6t_LED"); | |
268cb38e | 36 | |
b660d048 AN |
37 | static LIST_HEAD(xt_led_triggers); |
38 | static DEFINE_MUTEX(xt_led_mutex); | |
39 | ||
268cb38e AN |
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 | */ | |
45 | struct xt_led_info_internal { | |
b660d048 AN |
46 | struct list_head list; |
47 | int refcnt; | |
48 | char *trigger_id; | |
268cb38e AN |
49 | struct led_trigger netfilter_led_trigger; |
50 | struct timer_list timer; | |
51 | }; | |
52 | ||
53 | static unsigned int | |
4b560b44 | 54 | led_tg(struct sk_buff *skb, const struct xt_action_param *par) |
268cb38e AN |
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)) | |
b660d048 | 65 | led_trigger_event(&ledinternal->netfilter_led_trigger, LED_OFF); |
268cb38e AN |
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 | ||
84 | static void led_timeout_callback(unsigned long data) | |
85 | { | |
b660d048 | 86 | struct xt_led_info_internal *ledinternal = (struct xt_led_info_internal *)data; |
268cb38e AN |
87 | |
88 | led_trigger_event(&ledinternal->netfilter_led_trigger, LED_OFF); | |
89 | } | |
90 | ||
b660d048 AN |
91 | static 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 | ||
135367b8 | 103 | static int led_tg_check(const struct xt_tgchk_param *par) |
268cb38e AN |
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') { | |
8bee4bad | 110 | pr_info("No 'id' parameter given.\n"); |
d6b00a53 | 111 | return -EINVAL; |
268cb38e AN |
112 | } |
113 | ||
b660d048 AN |
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; | |
268cb38e | 123 | ledinternal = kzalloc(sizeof(struct xt_led_info_internal), GFP_KERNEL); |
85bc3f38 | 124 | if (!ledinternal) |
b660d048 AN |
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; | |
268cb38e | 130 | |
b660d048 AN |
131 | ledinternal->refcnt = 1; |
132 | ledinternal->netfilter_led_trigger.name = ledinternal->trigger_id; | |
268cb38e AN |
133 | |
134 | err = led_trigger_register(&ledinternal->netfilter_led_trigger); | |
135 | if (err) { | |
8bee4bad | 136 | pr_warning("led_trigger_register() failed\n"); |
268cb38e | 137 | if (err == -EEXIST) |
8bee4bad | 138 | pr_warning("Trigger name is already in use.\n"); |
268cb38e AN |
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, | |
b660d048 AN |
145 | (unsigned long)ledinternal); |
146 | ||
147 | list_add_tail(&ledinternal->list, &xt_led_triggers); | |
148 | ||
149 | out: | |
150 | mutex_unlock(&xt_led_mutex); | |
268cb38e AN |
151 | |
152 | ledinfo->internal_data = ledinternal; | |
b660d048 | 153 | |
d6b00a53 | 154 | return 0; |
268cb38e AN |
155 | |
156 | exit_alloc: | |
b660d048 AN |
157 | kfree(ledinternal->trigger_id); |
158 | ||
159 | exit_internal_alloc: | |
268cb38e | 160 | kfree(ledinternal); |
b660d048 AN |
161 | |
162 | exit_mutex_only: | |
163 | mutex_unlock(&xt_led_mutex); | |
164 | ||
4a5a5c73 | 165 | return err; |
268cb38e AN |
166 | } |
167 | ||
168 | static 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 | ||
b660d048 AN |
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 | ||
268cb38e AN |
182 | if (ledinfo->delay > 0) |
183 | del_timer_sync(&ledinternal->timer); | |
184 | ||
185 | led_trigger_unregister(&ledinternal->netfilter_led_trigger); | |
b660d048 AN |
186 | |
187 | mutex_unlock(&xt_led_mutex); | |
188 | ||
189 | kfree(ledinternal->trigger_id); | |
268cb38e AN |
190 | kfree(ledinternal); |
191 | } | |
192 | ||
193 | static struct xt_target led_tg_reg __read_mostly = { | |
194 | .name = "LED", | |
195 | .revision = 0, | |
196 | .family = NFPROTO_UNSPEC, | |
197 | .target = led_tg, | |
7d5f7ed8 | 198 | .targetsize = sizeof(struct xt_led_info), |
268cb38e AN |
199 | .checkentry = led_tg_check, |
200 | .destroy = led_tg_destroy, | |
201 | .me = THIS_MODULE, | |
202 | }; | |
203 | ||
204 | static int __init led_tg_init(void) | |
205 | { | |
206 | return xt_register_target(&led_tg_reg); | |
207 | } | |
208 | ||
209 | static void __exit led_tg_exit(void) | |
210 | { | |
211 | xt_unregister_target(&led_tg_reg); | |
212 | } | |
213 | ||
214 | module_init(led_tg_init); | |
215 | module_exit(led_tg_exit); |