From 5c350e5a380333c64da8580fa134a2fd8e71fea4 Mon Sep 17 00:00:00 2001 From: Jan Engelhardt Date: Tue, 4 Dec 2007 23:39:09 -0800 Subject: [PATCH] [NETFILTER]: IPv6 capable xt_TOS v1 target Extends the xt_DSCP target by xt_TOS v1 to add support for selectively setting and flipping any bit in the IPv4 TOS and IPv6 Priority fields. (ipt_TOS and xt_DSCP only accepted a limited range of possible values.) Signed-off-by: Jan Engelhardt Signed-off-by: Patrick McHardy Signed-off-by: David S. Miller --- include/linux/netfilter/xt_DSCP.h | 5 +++ net/netfilter/Kconfig | 2 +- net/netfilter/xt_DSCP.c | 63 +++++++++++++++++++++++++++++++ 3 files changed, 69 insertions(+), 1 deletion(-) diff --git a/include/linux/netfilter/xt_DSCP.h b/include/linux/netfilter/xt_DSCP.h index 3c7c963997..14da1968e2 100644 --- a/include/linux/netfilter/xt_DSCP.h +++ b/include/linux/netfilter/xt_DSCP.h @@ -17,4 +17,9 @@ struct xt_DSCP_info { u_int8_t dscp; }; +struct xt_tos_target_info { + u_int8_t tos_value; + u_int8_t tos_mask; +}; + #endif /* _XT_DSCP_TARGET_H */ diff --git a/net/netfilter/Kconfig b/net/netfilter/Kconfig index 9c82d4cc86..7bde631599 100644 --- a/net/netfilter/Kconfig +++ b/net/netfilter/Kconfig @@ -304,7 +304,7 @@ config NETFILTER_XT_TARGET_DSCP It also adds the "TOS" target, which allows you to create rules in the "mangle" table which alter the Type Of Service field of an IPv4 - packet prior to routing. + or the Priority field of an IPv6 packet, prior to routing. To compile it as a module, choose M here. If unsure, say N. diff --git a/net/netfilter/xt_DSCP.c b/net/netfilter/xt_DSCP.c index 40a4f1d719..fd7500ecad 100644 --- a/net/netfilter/xt_DSCP.c +++ b/net/netfilter/xt_DSCP.c @@ -26,6 +26,7 @@ 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 net_device *in, @@ -117,6 +118,50 @@ tos_tg_check_v0(const char *tablename, const void *e_void, return true; } +static unsigned int +tos_tg(struct sk_buff *skb, const struct net_device *in, + const struct net_device *out, unsigned int hooknum, + const struct xt_target *target, const void *targinfo) +{ + const struct xt_tos_target_info *info = 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 net_device *in, + const struct net_device *out, unsigned int hooknum, + const struct xt_target *target, const void *targinfo) +{ + const struct xt_tos_target_info *info = 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", @@ -146,6 +191,24 @@ static struct xt_target dscp_tg_reg[] __read_mostly = { .checkentry = tos_tg_check_v0, .me = THIS_MODULE, }, + { + .name = "TOS", + .revision = 1, + .family = AF_INET, + .table = "mangle", + .target = tos_tg, + .targetsize = sizeof(struct xt_tos_target_info), + .me = THIS_MODULE, + }, + { + .name = "TOS", + .revision = 1, + .family = AF_INET6, + .table = "mangle", + .target = tos_tg6, + .targetsize = sizeof(struct xt_tos_target_info), + .me = THIS_MODULE, + }, }; static int __init dscp_tg_init(void) -- 2.39.5