diff options
-rw-r--r-- | extensions/libxt_LED.c | 155 | ||||
-rw-r--r-- | extensions/libxt_LED.man | 30 |
2 files changed, 185 insertions, 0 deletions
diff --git a/extensions/libxt_LED.c b/extensions/libxt_LED.c new file mode 100644 index 00000000..af0e091e --- /dev/null +++ b/extensions/libxt_LED.c @@ -0,0 +1,155 @@ +/* + * libxt_LED.c - shared library add-on to iptables to add customized LED + * trigger support. + * + * (C) 2008 Adam Nielsen <a.nielsen@shikadi.net> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + */ + +#include <stdio.h> +#include <string.h> +#include <stdlib.h> +#include <getopt.h> +#include <stddef.h> + +#include <xtables.h> + +#include <linux/netfilter/xt_LED.h> + +static const struct option LED_opts[] = { + {.name = "led-trigger-id", .has_arg = true, .val = 'i'}, + {.name = "led-delay", .has_arg = true, .val = 'd'}, + {.name = "led-always-blink", .has_arg = false, .val = 'a'}, + {.name = NULL}, +}; + +static void LED_help(void) +{ + printf( +"LED target options:\n" +"--led-trigger-id name suffix for led trigger name\n" +"--led-delay ms leave the LED on for this number of\n" +" milliseconds after triggering.\n" +"--led-always-blink blink on arriving packets, even if\n" +" the LED is already on.\n" + ); +} + +static int LED_parse(int c, char **argv, int invert, unsigned int *flags, + const void *entry, struct xt_entry_target **target) +{ + struct xt_led_info *led = (void *)(*target)->data; + + switch (c) { + case 'i': + xtables_param_act(XTF_NO_INVERT, "LED", + "--led-trigger-id", invert); + if (strlen("netfilter-") + strlen(optarg) > sizeof(led->id)) + xtables_error(PARAMETER_PROBLEM, + "--led-trigger-id must be 16 chars or less"); + if (optarg[0] == '\0') + xtables_error(PARAMETER_PROBLEM, + "--led-trigger-id cannot be blank"); + + /* "netfilter-" + 16 char id == 26 == sizeof(led->id) */ + strcpy(led->id, "netfilter-"); + strcat(led->id, optarg); + *flags = 1; + return true; + + case 'd': + xtables_param_act(XTF_NO_INVERT, "LED", "--led-delay", invert); + if (strncasecmp(optarg, "inf", 3) == 0) + led->delay = -1; + else + led->delay = strtoul(optarg, NULL, 0); + + return true; + + case 'a': + if (!invert) + led->always_blink = 1; + return true; + } + return false; +} + +static void LED_final_check(unsigned int flags) +{ + if (flags == 0) + xtables_error(PARAMETER_PROBLEM, + "--led-trigger-id must be specified"); +} + +static void LED_print(const void *ip, const struct xt_entry_target *target, + int numeric) +{ + const struct xt_led_info *led = (void *)target->data; + const char *id = led->id + strlen("netfilter-"); /* trim off prefix */ + + printf("led-trigger-id:\""); + /* Escape double quotes and backslashes in the ID */ + while (*id != '\0') { + if (*id == '"' || *id == '\\') + printf("\\"); + printf("%c", *id++); + } + printf("\" "); + + if (led->delay == -1) + printf("led-delay:inf "); + else + printf("led-delay:%dms ", led->delay); + + if (led->always_blink) + printf("led-always-blink "); +} + +static void LED_save(const void *ip, const struct xt_entry_target *target) +{ + const struct xt_led_info *led = (void *)target->data; + const char *id = led->id + strlen("netfilter-"); /* trim off prefix */ + + printf("--led-trigger-id \""); + /* Escape double quotes and backslashes in the ID */ + while (*id != '\0') { + if (*id == '"' || *id == '\\') + printf("\\"); + printf("%c", *id++); + } + printf("\" "); + + /* Only print the delay if it's not zero (the default) */ + if (led->delay > 0) + printf("--led-delay %d ", led->delay); + else if (led->delay == -1) + printf("--led-delay inf "); + + /* Only print always_blink if it's not set to the default */ + if (led->always_blink) + printf("--led-always-blink "); +} + +static struct xtables_target led_tg_reg = { + .version = XTABLES_VERSION, + .name = "LED", + .family = PF_UNSPEC, + .revision = 0, + .size = XT_ALIGN(sizeof(struct xt_led_info)), + .userspacesize = offsetof(struct xt_led_info, internal_data), + .help = LED_help, + .parse = LED_parse, + .final_check = LED_final_check, + .extra_opts = LED_opts, + .print = LED_print, + .save = LED_save, +}; + +void _init(void) +{ + xtables_register_target(&led_tg_reg); +} diff --git a/extensions/libxt_LED.man b/extensions/libxt_LED.man new file mode 100644 index 00000000..0226f107 --- /dev/null +++ b/extensions/libxt_LED.man @@ -0,0 +1,30 @@ +This creates an LED-trigger that can then be attached to system indicator +lights, to blink or illuminate them when certain packets pass through the +system. One example might be to light up an LED for a few minutes every time +an SSH connection is made to the local machine. The following options control +the trigger behavior: +.TP +\fB--led-trigger-id\fP \fIname\fP +This is the name given to the LED trigger. The actual name of the trigger +will be prefixed with "netfilter-". +.TP +\fB--led-delay\fP \fIms\fP +This indicates how long (in milliseconds) the LED should be left illuminated +when a packet arrives before being switched off again. The default is 0 +(blink as fast as possible.) The special value \fIinf\fP can be given to +leave the LED on permanently once activated. (In this case the trigger will +need to be manually detached and reattached to the LED device to switch it +off again.) +.TP +\fB--led-always-blink\fP +Always make the LED blink on packet arrival, even if the LED is already on. +This allows notification of new packets even with long delay values (which +otherwise would result in a silent prolonging of the delay time.) +.TP +Example: +.TP +Create an LED trigger for incoming SSH traffic: +iptables -A INPUT -p tcp --dport 22 -j LED --led-trigger-id ssh +.TP +Then attach the new trigger to an LED: +echo netfilter-ssh >/sys/class/leds/\fIledname\fP/trigger |