Commit | Line | Data |
---|---|---|
935912c5 | 1 | // SPDX-License-Identifier: GPL-2.0-only |
268cb38e AN |
2 | /* |
3 | * xt_LED.c - netfilter target to make LEDs blink upon packet matches | |
4 | * | |
5 | * Copyright (C) 2008 Adam Nielsen <a.nielsen@shikadi.net> | |
268cb38e | 6 | */ |
8bee4bad | 7 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
268cb38e AN |
8 | #include <linux/module.h> |
9 | #include <linux/skbuff.h> | |
10 | #include <linux/netfilter/x_tables.h> | |
5a0e3ad6 | 11 | #include <linux/slab.h> |
268cb38e AN |
12 | #include <linux/leds.h> |
13 | #include <linux/mutex.h> | |
14 | ||
15 | #include <linux/netfilter/xt_LED.h> | |
16 | ||
17 | MODULE_LICENSE("GPL"); | |
18 | MODULE_AUTHOR("Adam Nielsen <a.nielsen@shikadi.net>"); | |
19 | MODULE_DESCRIPTION("Xtables: trigger LED devices on packet match"); | |
f1e231a3 JE |
20 | MODULE_ALIAS("ipt_LED"); |
21 | MODULE_ALIAS("ip6t_LED"); | |
268cb38e | 22 | |
b660d048 AN |
23 | static LIST_HEAD(xt_led_triggers); |
24 | static DEFINE_MUTEX(xt_led_mutex); | |
25 | ||
268cb38e AN |
26 | /* |
27 | * This is declared in here (the kernel module) only, to avoid having these | |
28 | * dependencies in userspace code. This is what xt_led_info.internal_data | |
29 | * points to. | |
30 | */ | |
31 | struct xt_led_info_internal { | |
b660d048 AN |
32 | struct list_head list; |
33 | int refcnt; | |
34 | char *trigger_id; | |
268cb38e AN |
35 | struct led_trigger netfilter_led_trigger; |
36 | struct timer_list timer; | |
37 | }; | |
38 | ||
8452e6ff JP |
39 | #define XT_LED_BLINK_DELAY 50 /* ms */ |
40 | ||
268cb38e | 41 | static unsigned int |
4b560b44 | 42 | led_tg(struct sk_buff *skb, const struct xt_action_param *par) |
268cb38e AN |
43 | { |
44 | const struct xt_led_info *ledinfo = par->targinfo; | |
45 | struct xt_led_info_internal *ledinternal = ledinfo->internal_data; | |
8452e6ff | 46 | unsigned long led_delay = XT_LED_BLINK_DELAY; |
268cb38e AN |
47 | |
48 | /* | |
49 | * If "always blink" is enabled, and there's still some time until the | |
50 | * LED will switch off, briefly switch it off now. | |
51 | */ | |
52 | if ((ledinfo->delay > 0) && ledinfo->always_blink && | |
53 | timer_pending(&ledinternal->timer)) | |
8452e6ff JP |
54 | led_trigger_blink_oneshot(&ledinternal->netfilter_led_trigger, |
55 | &led_delay, &led_delay, 1); | |
56 | else | |
57 | led_trigger_event(&ledinternal->netfilter_led_trigger, LED_FULL); | |
268cb38e AN |
58 | |
59 | /* If there's a positive delay, start/update the timer */ | |
60 | if (ledinfo->delay > 0) { | |
61 | mod_timer(&ledinternal->timer, | |
62 | jiffies + msecs_to_jiffies(ledinfo->delay)); | |
63 | ||
64 | /* Otherwise if there was no delay given, blink as fast as possible */ | |
65 | } else if (ledinfo->delay == 0) { | |
66 | led_trigger_event(&ledinternal->netfilter_led_trigger, LED_OFF); | |
67 | } | |
68 | ||
69 | /* else the delay is negative, which means switch on and stay on */ | |
70 | ||
71 | return XT_CONTINUE; | |
72 | } | |
73 | ||
e99e88a9 | 74 | static void led_timeout_callback(struct timer_list *t) |
268cb38e | 75 | { |
e99e88a9 KC |
76 | struct xt_led_info_internal *ledinternal = from_timer(ledinternal, t, |
77 | timer); | |
268cb38e AN |
78 | |
79 | led_trigger_event(&ledinternal->netfilter_led_trigger, LED_OFF); | |
80 | } | |
81 | ||
b660d048 AN |
82 | static struct xt_led_info_internal *led_trigger_lookup(const char *name) |
83 | { | |
84 | struct xt_led_info_internal *ledinternal; | |
85 | ||
86 | list_for_each_entry(ledinternal, &xt_led_triggers, list) { | |
87 | if (!strcmp(name, ledinternal->netfilter_led_trigger.name)) { | |
88 | return ledinternal; | |
89 | } | |
90 | } | |
91 | return NULL; | |
92 | } | |
93 | ||
135367b8 | 94 | static int led_tg_check(const struct xt_tgchk_param *par) |
268cb38e AN |
95 | { |
96 | struct xt_led_info *ledinfo = par->targinfo; | |
97 | struct xt_led_info_internal *ledinternal; | |
98 | int err; | |
99 | ||
0cc9501f | 100 | if (ledinfo->id[0] == '\0') |
d6b00a53 | 101 | return -EINVAL; |
268cb38e | 102 | |
b660d048 AN |
103 | mutex_lock(&xt_led_mutex); |
104 | ||
105 | ledinternal = led_trigger_lookup(ledinfo->id); | |
106 | if (ledinternal) { | |
107 | ledinternal->refcnt++; | |
108 | goto out; | |
109 | } | |
110 | ||
111 | err = -ENOMEM; | |
268cb38e | 112 | ledinternal = kzalloc(sizeof(struct xt_led_info_internal), GFP_KERNEL); |
85bc3f38 | 113 | if (!ledinternal) |
b660d048 AN |
114 | goto exit_mutex_only; |
115 | ||
116 | ledinternal->trigger_id = kstrdup(ledinfo->id, GFP_KERNEL); | |
117 | if (!ledinternal->trigger_id) | |
118 | goto exit_internal_alloc; | |
268cb38e | 119 | |
b660d048 AN |
120 | ledinternal->refcnt = 1; |
121 | ledinternal->netfilter_led_trigger.name = ledinternal->trigger_id; | |
268cb38e AN |
122 | |
123 | err = led_trigger_register(&ledinternal->netfilter_led_trigger); | |
124 | if (err) { | |
b2606644 | 125 | pr_info_ratelimited("Trigger name is already in use.\n"); |
268cb38e AN |
126 | goto exit_alloc; |
127 | } | |
128 | ||
10414014 PA |
129 | /* Since the letinternal timer can be shared between multiple targets, |
130 | * always set it up, even if the current target does not need it | |
131 | */ | |
132 | timer_setup(&ledinternal->timer, led_timeout_callback, 0); | |
b660d048 AN |
133 | |
134 | list_add_tail(&ledinternal->list, &xt_led_triggers); | |
135 | ||
136 | out: | |
137 | mutex_unlock(&xt_led_mutex); | |
268cb38e AN |
138 | |
139 | ledinfo->internal_data = ledinternal; | |
b660d048 | 140 | |
d6b00a53 | 141 | return 0; |
268cb38e AN |
142 | |
143 | exit_alloc: | |
b660d048 AN |
144 | kfree(ledinternal->trigger_id); |
145 | ||
146 | exit_internal_alloc: | |
268cb38e | 147 | kfree(ledinternal); |
b660d048 AN |
148 | |
149 | exit_mutex_only: | |
150 | mutex_unlock(&xt_led_mutex); | |
151 | ||
4a5a5c73 | 152 | return err; |
268cb38e AN |
153 | } |
154 | ||
155 | static void led_tg_destroy(const struct xt_tgdtor_param *par) | |
156 | { | |
157 | const struct xt_led_info *ledinfo = par->targinfo; | |
158 | struct xt_led_info_internal *ledinternal = ledinfo->internal_data; | |
159 | ||
b660d048 AN |
160 | mutex_lock(&xt_led_mutex); |
161 | ||
162 | if (--ledinternal->refcnt) { | |
163 | mutex_unlock(&xt_led_mutex); | |
164 | return; | |
165 | } | |
166 | ||
167 | list_del(&ledinternal->list); | |
168 | ||
10414014 | 169 | del_timer_sync(&ledinternal->timer); |
268cb38e AN |
170 | |
171 | led_trigger_unregister(&ledinternal->netfilter_led_trigger); | |
b660d048 AN |
172 | |
173 | mutex_unlock(&xt_led_mutex); | |
174 | ||
175 | kfree(ledinternal->trigger_id); | |
268cb38e AN |
176 | kfree(ledinternal); |
177 | } | |
178 | ||
179 | static struct xt_target led_tg_reg __read_mostly = { | |
180 | .name = "LED", | |
181 | .revision = 0, | |
182 | .family = NFPROTO_UNSPEC, | |
183 | .target = led_tg, | |
7d5f7ed8 | 184 | .targetsize = sizeof(struct xt_led_info), |
1e98ffea | 185 | .usersize = offsetof(struct xt_led_info, internal_data), |
268cb38e AN |
186 | .checkentry = led_tg_check, |
187 | .destroy = led_tg_destroy, | |
188 | .me = THIS_MODULE, | |
189 | }; | |
190 | ||
191 | static int __init led_tg_init(void) | |
192 | { | |
193 | return xt_register_target(&led_tg_reg); | |
194 | } | |
195 | ||
196 | static void __exit led_tg_exit(void) | |
197 | { | |
198 | xt_unregister_target(&led_tg_reg); | |
199 | } | |
200 | ||
201 | module_init(led_tg_init); | |
202 | module_exit(led_tg_exit); |