// SPDX-License-Identifier: GPL-2.0-only
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/* IP tables module for matching the value of the IPv4/IPv6 DSCP field
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*
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* (C) 2002 by Harald Welte <laforge@netfilter.org>
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*/
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#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
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#include <linux/module.h>
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#include <linux/skbuff.h>
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#include <linux/ip.h>
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#include <linux/ipv6.h>
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#include <net/dsfield.h>
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#include <linux/netfilter/x_tables.h>
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#include <linux/netfilter/xt_dscp.h>
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MODULE_AUTHOR("Harald Welte <laforge@netfilter.org>");
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MODULE_DESCRIPTION("Xtables: DSCP/TOS field match");
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MODULE_LICENSE("GPL");
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MODULE_ALIAS("ipt_dscp");
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MODULE_ALIAS("ip6t_dscp");
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MODULE_ALIAS("ipt_tos");
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MODULE_ALIAS("ip6t_tos");
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static bool
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dscp_mt(const struct sk_buff *skb, struct xt_action_param *par)
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{
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const struct xt_dscp_info *info = par->matchinfo;
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u_int8_t dscp = ipv4_get_dsfield(ip_hdr(skb)) >> XT_DSCP_SHIFT;
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return (dscp == info->dscp) ^ !!info->invert;
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}
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static bool
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dscp_mt6(const struct sk_buff *skb, struct xt_action_param *par)
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{
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const struct xt_dscp_info *info = par->matchinfo;
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u_int8_t dscp = ipv6_get_dsfield(ipv6_hdr(skb)) >> XT_DSCP_SHIFT;
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return (dscp == info->dscp) ^ !!info->invert;
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}
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static int dscp_mt_check(const struct xt_mtchk_param *par)
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{
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const struct xt_dscp_info *info = par->matchinfo;
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if (info->dscp > XT_DSCP_MAX)
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return -EDOM;
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return 0;
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}
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static bool tos_mt(const struct sk_buff *skb, struct xt_action_param *par)
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{
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const struct xt_tos_match_info *info = par->matchinfo;
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if (xt_family(par) == NFPROTO_IPV4)
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return ((ip_hdr(skb)->tos & info->tos_mask) ==
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info->tos_value) ^ !!info->invert;
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else
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return ((ipv6_get_dsfield(ipv6_hdr(skb)) & info->tos_mask) ==
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info->tos_value) ^ !!info->invert;
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}
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static struct xt_match dscp_mt_reg[] __read_mostly = {
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{
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.name = "dscp",
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.family = NFPROTO_IPV4,
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.checkentry = dscp_mt_check,
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.match = dscp_mt,
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.matchsize = sizeof(struct xt_dscp_info),
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.me = THIS_MODULE,
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},
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{
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.name = "dscp",
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.family = NFPROTO_IPV6,
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.checkentry = dscp_mt_check,
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.match = dscp_mt6,
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.matchsize = sizeof(struct xt_dscp_info),
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.me = THIS_MODULE,
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},
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{
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.name = "tos",
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.revision = 1,
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.family = NFPROTO_IPV4,
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.match = tos_mt,
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.matchsize = sizeof(struct xt_tos_match_info),
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.me = THIS_MODULE,
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},
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{
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.name = "tos",
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.revision = 1,
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.family = NFPROTO_IPV6,
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.match = tos_mt,
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.matchsize = sizeof(struct xt_tos_match_info),
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.me = THIS_MODULE,
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},
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};
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static int __init dscp_mt_init(void)
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{
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return xt_register_matches(dscp_mt_reg, ARRAY_SIZE(dscp_mt_reg));
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}
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static void __exit dscp_mt_exit(void)
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{
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xt_unregister_matches(dscp_mt_reg, ARRAY_SIZE(dscp_mt_reg));
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}
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module_init(dscp_mt_init);
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module_exit(dscp_mt_exit);
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