From 268cb38e1802db560c73167e643f14a3dcb4b07c Mon Sep 17 00:00:00 2001 From: Adam Nielsen Date: Fri, 20 Feb 2009 10:55:14 +0100 Subject: [PATCH] netfilter: x_tables: add LED trigger target Kernel module providing implementation of LED netfilter target. Each instance of the target appears as a led-trigger device, which can be associated with one or more LEDs in /sys/class/leds/ Signed-off-by: Adam Nielsen Acked-by: Richard Purdie Signed-off-by: Patrick McHardy --- drivers/leds/Kconfig | 3 + include/linux/netfilter/Kbuild | 1 + include/linux/netfilter/xt_LED.h | 13 +++ net/netfilter/Kconfig | 24 +++++ net/netfilter/Makefile | 1 + net/netfilter/xt_LED.c | 161 +++++++++++++++++++++++++++++++ 6 files changed, 203 insertions(+) create mode 100644 include/linux/netfilter/xt_LED.h create mode 100644 net/netfilter/xt_LED.c diff --git a/drivers/leds/Kconfig b/drivers/leds/Kconfig index 742713611bc5..556aeca0d860 100644 --- a/drivers/leds/Kconfig +++ b/drivers/leds/Kconfig @@ -223,4 +223,7 @@ config LEDS_TRIGGER_DEFAULT_ON This allows LEDs to be initialised in the ON state. If unsure, say Y. +comment "iptables trigger is under Netfilter config (LED target)" + depends on LEDS_TRIGGERS + endif # NEW_LEDS diff --git a/include/linux/netfilter/Kbuild b/include/linux/netfilter/Kbuild index 5a8af875bce2..deeaee5c83f2 100644 --- a/include/linux/netfilter/Kbuild +++ b/include/linux/netfilter/Kbuild @@ -7,6 +7,7 @@ header-y += xt_CLASSIFY.h header-y += xt_CONNMARK.h header-y += xt_CONNSECMARK.h header-y += xt_DSCP.h +header-y += xt_LED.h header-y += xt_MARK.h header-y += xt_NFLOG.h header-y += xt_NFQUEUE.h diff --git a/include/linux/netfilter/xt_LED.h b/include/linux/netfilter/xt_LED.h new file mode 100644 index 000000000000..4c91a0d770d0 --- /dev/null +++ b/include/linux/netfilter/xt_LED.h @@ -0,0 +1,13 @@ +#ifndef _XT_LED_H +#define _XT_LED_H + +struct xt_led_info { + char id[27]; /* Unique ID for this trigger in the LED class */ + __u8 always_blink; /* Blink even if the LED is already on */ + __u32 delay; /* Delay until LED is switched off after trigger */ + + /* Kernel data used in the module */ + void *internal_data __attribute__((aligned(8))); +}; + +#endif /* _XT_LED_H */ diff --git a/net/netfilter/Kconfig b/net/netfilter/Kconfig index 0eb98b4fbf44..cdbaaff6d0d6 100644 --- a/net/netfilter/Kconfig +++ b/net/netfilter/Kconfig @@ -372,6 +372,30 @@ config NETFILTER_XT_TARGET_HL since you can easily create immortal packets that loop forever on the network. +config NETFILTER_XT_TARGET_LED + tristate '"LED" target support' + depends on LEDS_CLASS + depends on NETFILTER_ADVANCED + help + This option adds a `LED' target, which allows you to blink LEDs in + response to particular packets passing through your machine. + + This can be used to turn a spare LED into a network activity LED, + which only flashes in response to FTP transfers, for example. Or + you could have an LED which lights up for a minute or two every time + somebody connects to your machine via SSH. + + You will need support for the "led" class to make this work. + + To create an LED trigger for incoming SSH traffic: + iptables -A INPUT -p tcp --dport 22 -j LED --led-trigger-id ssh --led-delay 1000 + + Then attach the new trigger to an LED on your system: + echo netfilter-ssh > /sys/class/leds//trigger + + For more information on the LEDs available on your system, see + Documentation/leds-class.txt + config NETFILTER_XT_TARGET_MARK tristate '"MARK" target support' default m if NETFILTER_ADVANCED=n diff --git a/net/netfilter/Makefile b/net/netfilter/Makefile index da73ed25701c..7a9b8397573a 100644 --- a/net/netfilter/Makefile +++ b/net/netfilter/Makefile @@ -46,6 +46,7 @@ obj-$(CONFIG_NETFILTER_XT_TARGET_CONNMARK) += xt_CONNMARK.o obj-$(CONFIG_NETFILTER_XT_TARGET_CONNSECMARK) += xt_CONNSECMARK.o obj-$(CONFIG_NETFILTER_XT_TARGET_DSCP) += xt_DSCP.o obj-$(CONFIG_NETFILTER_XT_TARGET_HL) += xt_HL.o +obj-$(CONFIG_NETFILTER_XT_TARGET_LED) += xt_LED.o obj-$(CONFIG_NETFILTER_XT_TARGET_MARK) += xt_MARK.o obj-$(CONFIG_NETFILTER_XT_TARGET_NFLOG) += xt_NFLOG.o obj-$(CONFIG_NETFILTER_XT_TARGET_NFQUEUE) += xt_NFQUEUE.o diff --git a/net/netfilter/xt_LED.c b/net/netfilter/xt_LED.c new file mode 100644 index 000000000000..8ff7843bb921 --- /dev/null +++ b/net/netfilter/xt_LED.c @@ -0,0 +1,161 @@ +/* + * xt_LED.c - netfilter target to make LEDs blink upon packet matches + * + * Copyright (C) 2008 Adam Nielsen + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; version 2 of the License. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA + * 02110-1301 USA. + * + */ + +#include +#include +#include +#include +#include + +#include + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Adam Nielsen "); +MODULE_DESCRIPTION("Xtables: trigger LED devices on packet match"); + +/* + * This is declared in here (the kernel module) only, to avoid having these + * dependencies in userspace code. This is what xt_led_info.internal_data + * points to. + */ +struct xt_led_info_internal { + struct led_trigger netfilter_led_trigger; + struct timer_list timer; +}; + +static unsigned int +led_tg(struct sk_buff *skb, const struct xt_target_param *par) +{ + const struct xt_led_info *ledinfo = par->targinfo; + struct xt_led_info_internal *ledinternal = ledinfo->internal_data; + + /* + * If "always blink" is enabled, and there's still some time until the + * LED will switch off, briefly switch it off now. + */ + if ((ledinfo->delay > 0) && ledinfo->always_blink && + timer_pending(&ledinternal->timer)) + led_trigger_event(&ledinternal->netfilter_led_trigger,LED_OFF); + + led_trigger_event(&ledinternal->netfilter_led_trigger, LED_FULL); + + /* If there's a positive delay, start/update the timer */ + if (ledinfo->delay > 0) { + mod_timer(&ledinternal->timer, + jiffies + msecs_to_jiffies(ledinfo->delay)); + + /* Otherwise if there was no delay given, blink as fast as possible */ + } else if (ledinfo->delay == 0) { + led_trigger_event(&ledinternal->netfilter_led_trigger, LED_OFF); + } + + /* else the delay is negative, which means switch on and stay on */ + + return XT_CONTINUE; +} + +static void led_timeout_callback(unsigned long data) +{ + struct xt_led_info *ledinfo = (struct xt_led_info *)data; + struct xt_led_info_internal *ledinternal = ledinfo->internal_data; + + led_trigger_event(&ledinternal->netfilter_led_trigger, LED_OFF); +} + +static bool led_tg_check(const struct xt_tgchk_param *par) +{ + struct xt_led_info *ledinfo = par->targinfo; + struct xt_led_info_internal *ledinternal; + int err; + + if (ledinfo->id[0] == '\0') { + printk(KERN_ERR KBUILD_MODNAME ": No 'id' parameter given.\n"); + return false; + } + + ledinternal = kzalloc(sizeof(struct xt_led_info_internal), GFP_KERNEL); + if (!ledinternal) { + printk(KERN_CRIT KBUILD_MODNAME ": out of memory\n"); + return false; + } + + ledinternal->netfilter_led_trigger.name = ledinfo->id; + + err = led_trigger_register(&ledinternal->netfilter_led_trigger); + if (err) { + printk(KERN_CRIT KBUILD_MODNAME + ": led_trigger_register() failed\n"); + if (err == -EEXIST) + printk(KERN_ERR KBUILD_MODNAME + ": Trigger name is already in use.\n"); + goto exit_alloc; + } + + /* See if we need to set up a timer */ + if (ledinfo->delay > 0) + setup_timer(&ledinternal->timer, led_timeout_callback, + (unsigned long)ledinfo); + + ledinfo->internal_data = ledinternal; + + return true; + +exit_alloc: + kfree(ledinternal); + + return false; +} + +static void led_tg_destroy(const struct xt_tgdtor_param *par) +{ + const struct xt_led_info *ledinfo = par->targinfo; + struct xt_led_info_internal *ledinternal = ledinfo->internal_data; + + if (ledinfo->delay > 0) + del_timer_sync(&ledinternal->timer); + + led_trigger_unregister(&ledinternal->netfilter_led_trigger); + kfree(ledinternal); +} + +static struct xt_target led_tg_reg __read_mostly = { + .name = "LED", + .revision = 0, + .family = NFPROTO_UNSPEC, + .target = led_tg, + .targetsize = XT_ALIGN(sizeof(struct xt_led_info)), + .checkentry = led_tg_check, + .destroy = led_tg_destroy, + .me = THIS_MODULE, +}; + +static int __init led_tg_init(void) +{ + return xt_register_target(&led_tg_reg); +} + +static void __exit led_tg_exit(void) +{ + xt_unregister_target(&led_tg_reg); +} + +module_init(led_tg_init); +module_exit(led_tg_exit);