d2912cb15b
Based on 2 normalized pattern(s): 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 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 # extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 4122 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Enrico Weigelt <info@metux.net> Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Allison Randal <allison@lohutok.net> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190604081206.933168790@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
68 lines
1.7 KiB
C
68 lines
1.7 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/* Kernel module to match packet length. */
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/* (C) 1999-2001 James Morris <jmorros@intercode.com.au>
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*/
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#include <linux/module.h>
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#include <linux/skbuff.h>
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#include <linux/ipv6.h>
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#include <net/ip.h>
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#include <linux/netfilter/xt_length.h>
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#include <linux/netfilter/x_tables.h>
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MODULE_AUTHOR("James Morris <jmorris@intercode.com.au>");
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MODULE_DESCRIPTION("Xtables: Packet length (Layer3,4,5) match");
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MODULE_LICENSE("GPL");
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MODULE_ALIAS("ipt_length");
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MODULE_ALIAS("ip6t_length");
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static bool
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length_mt(const struct sk_buff *skb, struct xt_action_param *par)
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{
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const struct xt_length_info *info = par->matchinfo;
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u_int16_t pktlen = ntohs(ip_hdr(skb)->tot_len);
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return (pktlen >= info->min && pktlen <= info->max) ^ info->invert;
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}
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static bool
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length_mt6(const struct sk_buff *skb, struct xt_action_param *par)
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{
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const struct xt_length_info *info = par->matchinfo;
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const u_int16_t pktlen = ntohs(ipv6_hdr(skb)->payload_len) +
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sizeof(struct ipv6hdr);
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return (pktlen >= info->min && pktlen <= info->max) ^ info->invert;
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}
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static struct xt_match length_mt_reg[] __read_mostly = {
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{
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.name = "length",
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.family = NFPROTO_IPV4,
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.match = length_mt,
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.matchsize = sizeof(struct xt_length_info),
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.me = THIS_MODULE,
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},
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{
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.name = "length",
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.family = NFPROTO_IPV6,
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.match = length_mt6,
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.matchsize = sizeof(struct xt_length_info),
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.me = THIS_MODULE,
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},
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};
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static int __init length_mt_init(void)
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{
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return xt_register_matches(length_mt_reg, ARRAY_SIZE(length_mt_reg));
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}
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static void __exit length_mt_exit(void)
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{
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xt_unregister_matches(length_mt_reg, ARRAY_SIZE(length_mt_reg));
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}
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module_init(length_mt_init);
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module_exit(length_mt_exit);
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