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1// SPDX-License-Identifier: GPL-2.0-only
2/* x_tables module for setting the IPv4/IPv6 DSCP field, Version 1.8
3 *
4 * (C) 2002 by Harald Welte <laforge@netfilter.org>
5 * based on ipt_FTOS.c (C) 2000 by Matthew G. Marsh <mgm@paktronix.com>
6 *
7 * See RFC2474 for a description of the DSCP field within the IP Header.
8*/
9#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
10#include <linux/module.h>
11#include <linux/skbuff.h>
12#include <linux/ip.h>
13#include <linux/ipv6.h>
14#include <net/dsfield.h>
15
16#include <linux/netfilter/x_tables.h>
17#include <linux/netfilter/xt_DSCP.h>
18
19MODULE_AUTHOR("Harald Welte <laforge@netfilter.org>");
20MODULE_DESCRIPTION("Xtables: DSCP/TOS field modification");
21MODULE_LICENSE("GPL");
22MODULE_ALIAS("ipt_DSCP");
23MODULE_ALIAS("ip6t_DSCP");
24MODULE_ALIAS("ipt_TOS");
25MODULE_ALIAS("ip6t_TOS");
26
27static unsigned int
28dscp_tg(struct sk_buff *skb, const struct xt_action_param *par)
29{
30 const struct xt_DSCP_info *dinfo = par->targinfo;
31 u_int8_t dscp = ipv4_get_dsfield(ip_hdr(skb)) >> XT_DSCP_SHIFT;
32
33 if (dscp != dinfo->dscp) {
34 if (skb_ensure_writable(skb, sizeof(struct iphdr)))
35 return NF_DROP;
36
37 ipv4_change_dsfield(ip_hdr(skb),
38 (__force __u8)(~XT_DSCP_MASK),
39 dinfo->dscp << XT_DSCP_SHIFT);
40
41 }
42 return XT_CONTINUE;
43}
44
45static unsigned int
46dscp_tg6(struct sk_buff *skb, const struct xt_action_param *par)
47{
48 const struct xt_DSCP_info *dinfo = par->targinfo;
49 u_int8_t dscp = ipv6_get_dsfield(ipv6_hdr(skb)) >> XT_DSCP_SHIFT;
50
51 if (dscp != dinfo->dscp) {
52 if (skb_ensure_writable(skb, sizeof(struct ipv6hdr)))
53 return NF_DROP;
54
55 ipv6_change_dsfield(ipv6_hdr(skb),
56 (__force __u8)(~XT_DSCP_MASK),
57 dinfo->dscp << XT_DSCP_SHIFT);
58 }
59 return XT_CONTINUE;
60}
61
62static int dscp_tg_check(const struct xt_tgchk_param *par)
63{
64 const struct xt_DSCP_info *info = par->targinfo;
65
66 if (info->dscp > XT_DSCP_MAX)
67 return -EDOM;
68 return 0;
69}
70
71static unsigned int
72tos_tg(struct sk_buff *skb, const struct xt_action_param *par)
73{
74 const struct xt_tos_target_info *info = par->targinfo;
75 struct iphdr *iph = ip_hdr(skb);
76 u_int8_t orig, nv;
77
78 orig = ipv4_get_dsfield(iph);
79 nv = (orig & ~info->tos_mask) ^ info->tos_value;
80
81 if (orig != nv) {
82 if (skb_ensure_writable(skb, sizeof(struct iphdr)))
83 return NF_DROP;
84 iph = ip_hdr(skb);
85 ipv4_change_dsfield(iph, 0, nv);
86 }
87
88 return XT_CONTINUE;
89}
90
91static unsigned int
92tos_tg6(struct sk_buff *skb, const struct xt_action_param *par)
93{
94 const struct xt_tos_target_info *info = par->targinfo;
95 struct ipv6hdr *iph = ipv6_hdr(skb);
96 u_int8_t orig, nv;
97
98 orig = ipv6_get_dsfield(iph);
99 nv = (orig & ~info->tos_mask) ^ info->tos_value;
100
101 if (orig != nv) {
102 if (skb_ensure_writable(skb, sizeof(struct iphdr)))
103 return NF_DROP;
104 iph = ipv6_hdr(skb);
105 ipv6_change_dsfield(iph, 0, nv);
106 }
107
108 return XT_CONTINUE;
109}
110
111static struct xt_target dscp_tg_reg[] __read_mostly = {
112 {
113 .name = "DSCP",
114 .family = NFPROTO_IPV4,
115 .checkentry = dscp_tg_check,
116 .target = dscp_tg,
117 .targetsize = sizeof(struct xt_DSCP_info),
118 .table = "mangle",
119 .me = THIS_MODULE,
120 },
121 {
122 .name = "DSCP",
123 .family = NFPROTO_IPV6,
124 .checkentry = dscp_tg_check,
125 .target = dscp_tg6,
126 .targetsize = sizeof(struct xt_DSCP_info),
127 .table = "mangle",
128 .me = THIS_MODULE,
129 },
130 {
131 .name = "TOS",
132 .revision = 1,
133 .family = NFPROTO_IPV4,
134 .table = "mangle",
135 .target = tos_tg,
136 .targetsize = sizeof(struct xt_tos_target_info),
137 .me = THIS_MODULE,
138 },
139 {
140 .name = "TOS",
141 .revision = 1,
142 .family = NFPROTO_IPV6,
143 .table = "mangle",
144 .target = tos_tg6,
145 .targetsize = sizeof(struct xt_tos_target_info),
146 .me = THIS_MODULE,
147 },
148};
149
150static int __init dscp_tg_init(void)
151{
152 return xt_register_targets(dscp_tg_reg, ARRAY_SIZE(dscp_tg_reg));
153}
154
155static void __exit dscp_tg_exit(void)
156{
157 xt_unregister_targets(dscp_tg_reg, ARRAY_SIZE(dscp_tg_reg));
158}
159
160module_init(dscp_tg_init);
161module_exit(dscp_tg_exit);
1/* x_tables module for setting the IPv4/IPv6 DSCP field, Version 1.8
2 *
3 * (C) 2002 by Harald Welte <laforge@netfilter.org>
4 * based on ipt_FTOS.c (C) 2000 by Matthew G. Marsh <mgm@paktronix.com>
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License version 2 as
8 * published by the Free Software Foundation.
9 *
10 * See RFC2474 for a description of the DSCP field within the IP Header.
11*/
12#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
13#include <linux/module.h>
14#include <linux/skbuff.h>
15#include <linux/ip.h>
16#include <linux/ipv6.h>
17#include <net/dsfield.h>
18
19#include <linux/netfilter/x_tables.h>
20#include <linux/netfilter/xt_DSCP.h>
21
22MODULE_AUTHOR("Harald Welte <laforge@netfilter.org>");
23MODULE_DESCRIPTION("Xtables: DSCP/TOS field modification");
24MODULE_LICENSE("GPL");
25MODULE_ALIAS("ipt_DSCP");
26MODULE_ALIAS("ip6t_DSCP");
27MODULE_ALIAS("ipt_TOS");
28MODULE_ALIAS("ip6t_TOS");
29
30static unsigned int
31dscp_tg(struct sk_buff *skb, const struct xt_action_param *par)
32{
33 const struct xt_DSCP_info *dinfo = par->targinfo;
34 u_int8_t dscp = ipv4_get_dsfield(ip_hdr(skb)) >> XT_DSCP_SHIFT;
35
36 if (dscp != dinfo->dscp) {
37 if (!skb_make_writable(skb, sizeof(struct iphdr)))
38 return NF_DROP;
39
40 ipv4_change_dsfield(ip_hdr(skb),
41 (__force __u8)(~XT_DSCP_MASK),
42 dinfo->dscp << XT_DSCP_SHIFT);
43
44 }
45 return XT_CONTINUE;
46}
47
48static unsigned int
49dscp_tg6(struct sk_buff *skb, const struct xt_action_param *par)
50{
51 const struct xt_DSCP_info *dinfo = par->targinfo;
52 u_int8_t dscp = ipv6_get_dsfield(ipv6_hdr(skb)) >> XT_DSCP_SHIFT;
53
54 if (dscp != dinfo->dscp) {
55 if (!skb_make_writable(skb, sizeof(struct ipv6hdr)))
56 return NF_DROP;
57
58 ipv6_change_dsfield(ipv6_hdr(skb),
59 (__force __u8)(~XT_DSCP_MASK),
60 dinfo->dscp << XT_DSCP_SHIFT);
61 }
62 return XT_CONTINUE;
63}
64
65static int dscp_tg_check(const struct xt_tgchk_param *par)
66{
67 const struct xt_DSCP_info *info = par->targinfo;
68
69 if (info->dscp > XT_DSCP_MAX) {
70 pr_info("dscp %x out of range\n", info->dscp);
71 return -EDOM;
72 }
73 return 0;
74}
75
76static unsigned int
77tos_tg(struct sk_buff *skb, const struct xt_action_param *par)
78{
79 const struct xt_tos_target_info *info = par->targinfo;
80 struct iphdr *iph = ip_hdr(skb);
81 u_int8_t orig, nv;
82
83 orig = ipv4_get_dsfield(iph);
84 nv = (orig & ~info->tos_mask) ^ info->tos_value;
85
86 if (orig != nv) {
87 if (!skb_make_writable(skb, sizeof(struct iphdr)))
88 return NF_DROP;
89 iph = ip_hdr(skb);
90 ipv4_change_dsfield(iph, 0, nv);
91 }
92
93 return XT_CONTINUE;
94}
95
96static unsigned int
97tos_tg6(struct sk_buff *skb, const struct xt_action_param *par)
98{
99 const struct xt_tos_target_info *info = par->targinfo;
100 struct ipv6hdr *iph = ipv6_hdr(skb);
101 u_int8_t orig, nv;
102
103 orig = ipv6_get_dsfield(iph);
104 nv = (orig & ~info->tos_mask) ^ info->tos_value;
105
106 if (orig != nv) {
107 if (!skb_make_writable(skb, sizeof(struct iphdr)))
108 return NF_DROP;
109 iph = ipv6_hdr(skb);
110 ipv6_change_dsfield(iph, 0, nv);
111 }
112
113 return XT_CONTINUE;
114}
115
116static struct xt_target dscp_tg_reg[] __read_mostly = {
117 {
118 .name = "DSCP",
119 .family = NFPROTO_IPV4,
120 .checkentry = dscp_tg_check,
121 .target = dscp_tg,
122 .targetsize = sizeof(struct xt_DSCP_info),
123 .table = "mangle",
124 .me = THIS_MODULE,
125 },
126 {
127 .name = "DSCP",
128 .family = NFPROTO_IPV6,
129 .checkentry = dscp_tg_check,
130 .target = dscp_tg6,
131 .targetsize = sizeof(struct xt_DSCP_info),
132 .table = "mangle",
133 .me = THIS_MODULE,
134 },
135 {
136 .name = "TOS",
137 .revision = 1,
138 .family = NFPROTO_IPV4,
139 .table = "mangle",
140 .target = tos_tg,
141 .targetsize = sizeof(struct xt_tos_target_info),
142 .me = THIS_MODULE,
143 },
144 {
145 .name = "TOS",
146 .revision = 1,
147 .family = NFPROTO_IPV6,
148 .table = "mangle",
149 .target = tos_tg6,
150 .targetsize = sizeof(struct xt_tos_target_info),
151 .me = THIS_MODULE,
152 },
153};
154
155static int __init dscp_tg_init(void)
156{
157 return xt_register_targets(dscp_tg_reg, ARRAY_SIZE(dscp_tg_reg));
158}
159
160static void __exit dscp_tg_exit(void)
161{
162 xt_unregister_targets(dscp_tg_reg, ARRAY_SIZE(dscp_tg_reg));
163}
164
165module_init(dscp_tg_init);
166module_exit(dscp_tg_exit);