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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// 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
27#define XT_DSCP_ECN_MASK 3u
28
29static unsigned int
30dscp_tg(struct sk_buff *skb, const struct xt_action_param *par)
31{
32 const struct xt_DSCP_info *dinfo = par->targinfo;
33 u_int8_t dscp = ipv4_get_dsfield(ip_hdr(skb)) >> XT_DSCP_SHIFT;
34
35 if (dscp != dinfo->dscp) {
36 if (skb_ensure_writable(skb, sizeof(struct iphdr)))
37 return NF_DROP;
38
39 ipv4_change_dsfield(ip_hdr(skb), XT_DSCP_ECN_MASK,
40 dinfo->dscp << XT_DSCP_SHIFT);
41
42 }
43 return XT_CONTINUE;
44}
45
46static unsigned int
47dscp_tg6(struct sk_buff *skb, const struct xt_action_param *par)
48{
49 const struct xt_DSCP_info *dinfo = par->targinfo;
50 u_int8_t dscp = ipv6_get_dsfield(ipv6_hdr(skb)) >> XT_DSCP_SHIFT;
51
52 if (dscp != dinfo->dscp) {
53 if (skb_ensure_writable(skb, sizeof(struct ipv6hdr)))
54 return NF_DROP;
55
56 ipv6_change_dsfield(ipv6_hdr(skb), XT_DSCP_ECN_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);