Yasuyuki Kozakai | a468701 | 2006-08-22 00:30:26 -0700 | [diff] [blame] | 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. |
Yasuyuki Kozakai | a468701 | 2006-08-22 00:30:26 -0700 | [diff] [blame] | 11 | */ |
| 12 | |
| 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> |
Jan Engelhardt | c9fd496 | 2007-12-04 23:38:13 -0800 | [diff] [blame] | 21 | #include <linux/netfilter_ipv4/ipt_TOS.h> |
Yasuyuki Kozakai | a468701 | 2006-08-22 00:30:26 -0700 | [diff] [blame] | 22 | |
| 23 | MODULE_AUTHOR("Harald Welte <laforge@netfilter.org>"); |
Jan Engelhardt | 2ae15b6 | 2008-01-14 23:42:28 -0800 | [diff] [blame] | 24 | MODULE_DESCRIPTION("Xtables: DSCP/TOS field modification"); |
Yasuyuki Kozakai | a468701 | 2006-08-22 00:30:26 -0700 | [diff] [blame] | 25 | MODULE_LICENSE("GPL"); |
| 26 | MODULE_ALIAS("ipt_DSCP"); |
| 27 | MODULE_ALIAS("ip6t_DSCP"); |
Jan Engelhardt | c9fd496 | 2007-12-04 23:38:13 -0800 | [diff] [blame] | 28 | MODULE_ALIAS("ipt_TOS"); |
Jan Engelhardt | 5c350e5 | 2007-12-04 23:39:09 -0800 | [diff] [blame] | 29 | MODULE_ALIAS("ip6t_TOS"); |
Yasuyuki Kozakai | a468701 | 2006-08-22 00:30:26 -0700 | [diff] [blame] | 30 | |
Jan Engelhardt | d3c5ee6 | 2007-12-04 23:24:03 -0800 | [diff] [blame] | 31 | static unsigned int |
Jan Engelhardt | 7eb3558 | 2008-10-08 11:35:19 +0200 | [diff] [blame] | 32 | dscp_tg(struct sk_buff *skb, const struct xt_target_param *par) |
Yasuyuki Kozakai | a468701 | 2006-08-22 00:30:26 -0700 | [diff] [blame] | 33 | { |
Jan Engelhardt | 7eb3558 | 2008-10-08 11:35:19 +0200 | [diff] [blame] | 34 | const struct xt_DSCP_info *dinfo = par->targinfo; |
Herbert Xu | 3db05fe | 2007-10-15 00:53:15 -0700 | [diff] [blame] | 35 | u_int8_t dscp = ipv4_get_dsfield(ip_hdr(skb)) >> XT_DSCP_SHIFT; |
Yasuyuki Kozakai | a468701 | 2006-08-22 00:30:26 -0700 | [diff] [blame] | 36 | |
| 37 | if (dscp != dinfo->dscp) { |
Herbert Xu | 3db05fe | 2007-10-15 00:53:15 -0700 | [diff] [blame] | 38 | if (!skb_make_writable(skb, sizeof(struct iphdr))) |
Yasuyuki Kozakai | a468701 | 2006-08-22 00:30:26 -0700 | [diff] [blame] | 39 | return NF_DROP; |
| 40 | |
Herbert Xu | 3db05fe | 2007-10-15 00:53:15 -0700 | [diff] [blame] | 41 | ipv4_change_dsfield(ip_hdr(skb), (__u8)(~XT_DSCP_MASK), |
Yasuyuki Kozakai | a468701 | 2006-08-22 00:30:26 -0700 | [diff] [blame] | 42 | dinfo->dscp << XT_DSCP_SHIFT); |
| 43 | |
| 44 | } |
| 45 | return XT_CONTINUE; |
| 46 | } |
| 47 | |
Jan Engelhardt | d3c5ee6 | 2007-12-04 23:24:03 -0800 | [diff] [blame] | 48 | static unsigned int |
Jan Engelhardt | 7eb3558 | 2008-10-08 11:35:19 +0200 | [diff] [blame] | 49 | dscp_tg6(struct sk_buff *skb, const struct xt_target_param *par) |
Yasuyuki Kozakai | a468701 | 2006-08-22 00:30:26 -0700 | [diff] [blame] | 50 | { |
Jan Engelhardt | 7eb3558 | 2008-10-08 11:35:19 +0200 | [diff] [blame] | 51 | const struct xt_DSCP_info *dinfo = par->targinfo; |
Herbert Xu | 3db05fe | 2007-10-15 00:53:15 -0700 | [diff] [blame] | 52 | u_int8_t dscp = ipv6_get_dsfield(ipv6_hdr(skb)) >> XT_DSCP_SHIFT; |
Yasuyuki Kozakai | a468701 | 2006-08-22 00:30:26 -0700 | [diff] [blame] | 53 | |
| 54 | if (dscp != dinfo->dscp) { |
Herbert Xu | 3db05fe | 2007-10-15 00:53:15 -0700 | [diff] [blame] | 55 | if (!skb_make_writable(skb, sizeof(struct ipv6hdr))) |
Yasuyuki Kozakai | a468701 | 2006-08-22 00:30:26 -0700 | [diff] [blame] | 56 | return NF_DROP; |
| 57 | |
Herbert Xu | 3db05fe | 2007-10-15 00:53:15 -0700 | [diff] [blame] | 58 | ipv6_change_dsfield(ipv6_hdr(skb), (__u8)(~XT_DSCP_MASK), |
Yasuyuki Kozakai | a468701 | 2006-08-22 00:30:26 -0700 | [diff] [blame] | 59 | dinfo->dscp << XT_DSCP_SHIFT); |
| 60 | } |
| 61 | return XT_CONTINUE; |
| 62 | } |
| 63 | |
Jan Engelhardt | af5d6dc | 2008-10-08 11:35:19 +0200 | [diff] [blame] | 64 | static bool dscp_tg_check(const struct xt_tgchk_param *par) |
Yasuyuki Kozakai | a468701 | 2006-08-22 00:30:26 -0700 | [diff] [blame] | 65 | { |
Jan Engelhardt | af5d6dc | 2008-10-08 11:35:19 +0200 | [diff] [blame] | 66 | const struct xt_DSCP_info *info = par->targinfo; |
Yasuyuki Kozakai | a468701 | 2006-08-22 00:30:26 -0700 | [diff] [blame] | 67 | |
Jan Engelhardt | af5d6dc | 2008-10-08 11:35:19 +0200 | [diff] [blame] | 68 | if (info->dscp > XT_DSCP_MAX) { |
| 69 | printk(KERN_WARNING "DSCP: dscp %x out of range\n", info->dscp); |
Jan Engelhardt | e1931b7 | 2007-07-07 22:16:26 -0700 | [diff] [blame] | 70 | return false; |
Yasuyuki Kozakai | a468701 | 2006-08-22 00:30:26 -0700 | [diff] [blame] | 71 | } |
Jan Engelhardt | e1931b7 | 2007-07-07 22:16:26 -0700 | [diff] [blame] | 72 | return true; |
Yasuyuki Kozakai | a468701 | 2006-08-22 00:30:26 -0700 | [diff] [blame] | 73 | } |
| 74 | |
Jan Engelhardt | c9fd496 | 2007-12-04 23:38:13 -0800 | [diff] [blame] | 75 | static unsigned int |
Jan Engelhardt | 7eb3558 | 2008-10-08 11:35:19 +0200 | [diff] [blame] | 76 | tos_tg_v0(struct sk_buff *skb, const struct xt_target_param *par) |
Jan Engelhardt | c9fd496 | 2007-12-04 23:38:13 -0800 | [diff] [blame] | 77 | { |
Jan Engelhardt | 7eb3558 | 2008-10-08 11:35:19 +0200 | [diff] [blame] | 78 | const struct ipt_tos_target_info *info = par->targinfo; |
Jan Engelhardt | c9fd496 | 2007-12-04 23:38:13 -0800 | [diff] [blame] | 79 | struct iphdr *iph = ip_hdr(skb); |
| 80 | u_int8_t oldtos; |
| 81 | |
| 82 | if ((iph->tos & IPTOS_TOS_MASK) != info->tos) { |
| 83 | if (!skb_make_writable(skb, sizeof(struct iphdr))) |
| 84 | return NF_DROP; |
| 85 | |
| 86 | iph = ip_hdr(skb); |
| 87 | oldtos = iph->tos; |
| 88 | iph->tos = (iph->tos & IPTOS_PREC_MASK) | info->tos; |
| 89 | csum_replace2(&iph->check, htons(oldtos), htons(iph->tos)); |
| 90 | } |
| 91 | |
| 92 | return XT_CONTINUE; |
| 93 | } |
| 94 | |
Jan Engelhardt | af5d6dc | 2008-10-08 11:35:19 +0200 | [diff] [blame] | 95 | static bool tos_tg_check_v0(const struct xt_tgchk_param *par) |
Jan Engelhardt | c9fd496 | 2007-12-04 23:38:13 -0800 | [diff] [blame] | 96 | { |
Jan Engelhardt | af5d6dc | 2008-10-08 11:35:19 +0200 | [diff] [blame] | 97 | const struct ipt_tos_target_info *info = par->targinfo; |
| 98 | const uint8_t tos = info->tos; |
Jan Engelhardt | c9fd496 | 2007-12-04 23:38:13 -0800 | [diff] [blame] | 99 | |
| 100 | if (tos != IPTOS_LOWDELAY && tos != IPTOS_THROUGHPUT && |
| 101 | tos != IPTOS_RELIABILITY && tos != IPTOS_MINCOST && |
| 102 | tos != IPTOS_NORMALSVC) { |
| 103 | printk(KERN_WARNING "TOS: bad tos value %#x\n", tos); |
| 104 | return false; |
| 105 | } |
| 106 | |
| 107 | return true; |
| 108 | } |
| 109 | |
Jan Engelhardt | 5c350e5 | 2007-12-04 23:39:09 -0800 | [diff] [blame] | 110 | static unsigned int |
Jan Engelhardt | 7eb3558 | 2008-10-08 11:35:19 +0200 | [diff] [blame] | 111 | tos_tg(struct sk_buff *skb, const struct xt_target_param *par) |
Jan Engelhardt | 5c350e5 | 2007-12-04 23:39:09 -0800 | [diff] [blame] | 112 | { |
Jan Engelhardt | 7eb3558 | 2008-10-08 11:35:19 +0200 | [diff] [blame] | 113 | const struct xt_tos_target_info *info = par->targinfo; |
Jan Engelhardt | 5c350e5 | 2007-12-04 23:39:09 -0800 | [diff] [blame] | 114 | struct iphdr *iph = ip_hdr(skb); |
| 115 | u_int8_t orig, nv; |
| 116 | |
| 117 | orig = ipv4_get_dsfield(iph); |
Jan Engelhardt | 9bb268e | 2008-01-14 23:32:37 -0800 | [diff] [blame] | 118 | nv = (orig & ~info->tos_mask) ^ info->tos_value; |
Jan Engelhardt | 5c350e5 | 2007-12-04 23:39:09 -0800 | [diff] [blame] | 119 | |
| 120 | if (orig != nv) { |
| 121 | if (!skb_make_writable(skb, sizeof(struct iphdr))) |
| 122 | return NF_DROP; |
| 123 | iph = ip_hdr(skb); |
Jan Engelhardt | cdfe8b9 | 2008-01-14 23:32:54 -0800 | [diff] [blame] | 124 | ipv4_change_dsfield(iph, 0, nv); |
Jan Engelhardt | 5c350e5 | 2007-12-04 23:39:09 -0800 | [diff] [blame] | 125 | } |
| 126 | |
| 127 | return XT_CONTINUE; |
| 128 | } |
| 129 | |
| 130 | static unsigned int |
Jan Engelhardt | 7eb3558 | 2008-10-08 11:35:19 +0200 | [diff] [blame] | 131 | tos_tg6(struct sk_buff *skb, const struct xt_target_param *par) |
Jan Engelhardt | 5c350e5 | 2007-12-04 23:39:09 -0800 | [diff] [blame] | 132 | { |
Jan Engelhardt | 7eb3558 | 2008-10-08 11:35:19 +0200 | [diff] [blame] | 133 | const struct xt_tos_target_info *info = par->targinfo; |
Jan Engelhardt | 5c350e5 | 2007-12-04 23:39:09 -0800 | [diff] [blame] | 134 | struct ipv6hdr *iph = ipv6_hdr(skb); |
| 135 | u_int8_t orig, nv; |
| 136 | |
| 137 | orig = ipv6_get_dsfield(iph); |
| 138 | nv = (orig & info->tos_mask) ^ info->tos_value; |
| 139 | |
| 140 | if (orig != nv) { |
| 141 | if (!skb_make_writable(skb, sizeof(struct iphdr))) |
| 142 | return NF_DROP; |
| 143 | iph = ipv6_hdr(skb); |
Jan Engelhardt | cdfe8b9 | 2008-01-14 23:32:54 -0800 | [diff] [blame] | 144 | ipv6_change_dsfield(iph, 0, nv); |
Jan Engelhardt | 5c350e5 | 2007-12-04 23:39:09 -0800 | [diff] [blame] | 145 | } |
| 146 | |
| 147 | return XT_CONTINUE; |
| 148 | } |
| 149 | |
Jan Engelhardt | d3c5ee6 | 2007-12-04 23:24:03 -0800 | [diff] [blame] | 150 | static struct xt_target dscp_tg_reg[] __read_mostly = { |
Patrick McHardy | 4470bbc | 2006-08-22 00:34:04 -0700 | [diff] [blame] | 151 | { |
| 152 | .name = "DSCP", |
Jan Engelhardt | ee999d8 | 2008-10-08 11:35:01 +0200 | [diff] [blame] | 153 | .family = NFPROTO_IPV4, |
Jan Engelhardt | d3c5ee6 | 2007-12-04 23:24:03 -0800 | [diff] [blame] | 154 | .checkentry = dscp_tg_check, |
| 155 | .target = dscp_tg, |
Patrick McHardy | 4470bbc | 2006-08-22 00:34:04 -0700 | [diff] [blame] | 156 | .targetsize = sizeof(struct xt_DSCP_info), |
| 157 | .table = "mangle", |
| 158 | .me = THIS_MODULE, |
| 159 | }, |
| 160 | { |
| 161 | .name = "DSCP", |
Jan Engelhardt | ee999d8 | 2008-10-08 11:35:01 +0200 | [diff] [blame] | 162 | .family = NFPROTO_IPV6, |
Jan Engelhardt | d3c5ee6 | 2007-12-04 23:24:03 -0800 | [diff] [blame] | 163 | .checkentry = dscp_tg_check, |
| 164 | .target = dscp_tg6, |
Patrick McHardy | 4470bbc | 2006-08-22 00:34:04 -0700 | [diff] [blame] | 165 | .targetsize = sizeof(struct xt_DSCP_info), |
| 166 | .table = "mangle", |
| 167 | .me = THIS_MODULE, |
| 168 | }, |
Jan Engelhardt | c9fd496 | 2007-12-04 23:38:13 -0800 | [diff] [blame] | 169 | { |
| 170 | .name = "TOS", |
| 171 | .revision = 0, |
Jan Engelhardt | ee999d8 | 2008-10-08 11:35:01 +0200 | [diff] [blame] | 172 | .family = NFPROTO_IPV4, |
Jan Engelhardt | c9fd496 | 2007-12-04 23:38:13 -0800 | [diff] [blame] | 173 | .table = "mangle", |
| 174 | .target = tos_tg_v0, |
| 175 | .targetsize = sizeof(struct ipt_tos_target_info), |
| 176 | .checkentry = tos_tg_check_v0, |
| 177 | .me = THIS_MODULE, |
| 178 | }, |
Jan Engelhardt | 5c350e5 | 2007-12-04 23:39:09 -0800 | [diff] [blame] | 179 | { |
| 180 | .name = "TOS", |
| 181 | .revision = 1, |
Jan Engelhardt | ee999d8 | 2008-10-08 11:35:01 +0200 | [diff] [blame] | 182 | .family = NFPROTO_IPV4, |
Jan Engelhardt | 5c350e5 | 2007-12-04 23:39:09 -0800 | [diff] [blame] | 183 | .table = "mangle", |
| 184 | .target = tos_tg, |
| 185 | .targetsize = sizeof(struct xt_tos_target_info), |
| 186 | .me = THIS_MODULE, |
| 187 | }, |
| 188 | { |
| 189 | .name = "TOS", |
| 190 | .revision = 1, |
Jan Engelhardt | ee999d8 | 2008-10-08 11:35:01 +0200 | [diff] [blame] | 191 | .family = NFPROTO_IPV6, |
Jan Engelhardt | 5c350e5 | 2007-12-04 23:39:09 -0800 | [diff] [blame] | 192 | .table = "mangle", |
| 193 | .target = tos_tg6, |
| 194 | .targetsize = sizeof(struct xt_tos_target_info), |
| 195 | .me = THIS_MODULE, |
| 196 | }, |
Yasuyuki Kozakai | a468701 | 2006-08-22 00:30:26 -0700 | [diff] [blame] | 197 | }; |
| 198 | |
Jan Engelhardt | d3c5ee6 | 2007-12-04 23:24:03 -0800 | [diff] [blame] | 199 | static int __init dscp_tg_init(void) |
Yasuyuki Kozakai | a468701 | 2006-08-22 00:30:26 -0700 | [diff] [blame] | 200 | { |
Jan Engelhardt | d3c5ee6 | 2007-12-04 23:24:03 -0800 | [diff] [blame] | 201 | return xt_register_targets(dscp_tg_reg, ARRAY_SIZE(dscp_tg_reg)); |
Yasuyuki Kozakai | a468701 | 2006-08-22 00:30:26 -0700 | [diff] [blame] | 202 | } |
| 203 | |
Jan Engelhardt | d3c5ee6 | 2007-12-04 23:24:03 -0800 | [diff] [blame] | 204 | static void __exit dscp_tg_exit(void) |
Yasuyuki Kozakai | a468701 | 2006-08-22 00:30:26 -0700 | [diff] [blame] | 205 | { |
Jan Engelhardt | d3c5ee6 | 2007-12-04 23:24:03 -0800 | [diff] [blame] | 206 | xt_unregister_targets(dscp_tg_reg, ARRAY_SIZE(dscp_tg_reg)); |
Yasuyuki Kozakai | a468701 | 2006-08-22 00:30:26 -0700 | [diff] [blame] | 207 | } |
| 208 | |
Jan Engelhardt | d3c5ee6 | 2007-12-04 23:24:03 -0800 | [diff] [blame] | 209 | module_init(dscp_tg_init); |
| 210 | module_exit(dscp_tg_exit); |