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