From 81eb6a1487718a89621a0e0be7fafd0cd7c429a4 Mon Sep 17 00:00:00 2001 From: Patrick McHardy Date: Tue, 27 Aug 2013 08:50:15 +0200 Subject: [PATCH] net: syncookies: export cookie_v6_init_sequence/cookie_v6_check Extract the local TCP stack independant parts of tcp_v6_init_sequence() and cookie_v6_check() and export them for use by the upcoming IPv6 SYNPROXY target. Signed-off-by: Patrick McHardy Acked-by: David S. Miller Tested-by: Martin Topholm Signed-off-by: Jesper Dangaard Brouer Signed-off-by: Pablo Neira Ayuso --- include/net/tcp.h | 4 ++++ net/ipv6/syncookies.c | 25 ++++++++++++++++--------- 2 files changed, 20 insertions(+), 9 deletions(-) diff --git a/include/net/tcp.h b/include/net/tcp.h index 8e2b636..dd5e16f 100644 --- a/include/net/tcp.h +++ b/include/net/tcp.h @@ -499,8 +499,12 @@ extern bool cookie_check_timestamp(struct tcp_options_received *opt, struct net *net, bool *ecn_ok); /* From net/ipv6/syncookies.c */ +extern int __cookie_v6_check(const struct ipv6hdr *iph, const struct tcphdr *th, + u32 cookie); extern struct sock *cookie_v6_check(struct sock *sk, struct sk_buff *skb); #ifdef CONFIG_SYN_COOKIES +extern u32 __cookie_v6_init_sequence(const struct ipv6hdr *iph, + const struct tcphdr *th, u16 *mssp); extern __u32 cookie_v6_init_sequence(struct sock *sk, const struct sk_buff *skb, __u16 *mss); #else diff --git a/net/ipv6/syncookies.c b/net/ipv6/syncookies.c index d5dda20..bf63ac8 100644 --- a/net/ipv6/syncookies.c +++ b/net/ipv6/syncookies.c @@ -112,32 +112,38 @@ static __u32 check_tcp_syn_cookie(__u32 cookie, const struct in6_addr *saddr, & COOKIEMASK; } -__u32 cookie_v6_init_sequence(struct sock *sk, const struct sk_buff *skb, __u16 *mssp) +u32 __cookie_v6_init_sequence(const struct ipv6hdr *iph, + const struct tcphdr *th, __u16 *mssp) { - const struct ipv6hdr *iph = ipv6_hdr(skb); - const struct tcphdr *th = tcp_hdr(skb); int mssind; const __u16 mss = *mssp; - tcp_synq_overflow(sk); - for (mssind = ARRAY_SIZE(msstab) - 1; mssind ; mssind--) if (mss >= msstab[mssind]) break; *mssp = msstab[mssind]; - NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_SYNCOOKIESSENT); - return secure_tcp_syn_cookie(&iph->saddr, &iph->daddr, th->source, th->dest, ntohl(th->seq), jiffies / (HZ * 60), mssind); } +EXPORT_SYMBOL_GPL(__cookie_v6_init_sequence); -static inline int cookie_check(const struct sk_buff *skb, __u32 cookie) +__u32 cookie_v6_init_sequence(struct sock *sk, const struct sk_buff *skb, __u16 *mssp) { const struct ipv6hdr *iph = ipv6_hdr(skb); const struct tcphdr *th = tcp_hdr(skb); + + tcp_synq_overflow(sk); + NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_SYNCOOKIESSENT); + + return __cookie_v6_init_sequence(iph, th, mssp); +} + +int __cookie_v6_check(const struct ipv6hdr *iph, const struct tcphdr *th, + __u32 cookie) +{ __u32 seq = ntohl(th->seq) - 1; __u32 mssind = check_tcp_syn_cookie(cookie, &iph->saddr, &iph->daddr, th->source, th->dest, seq, @@ -145,6 +151,7 @@ static inline int cookie_check(const struct sk_buff *skb, __u32 cookie) return mssind < ARRAY_SIZE(msstab) ? msstab[mssind] : 0; } +EXPORT_SYMBOL_GPL(__cookie_v6_check); struct sock *cookie_v6_check(struct sock *sk, struct sk_buff *skb) { @@ -167,7 +174,7 @@ struct sock *cookie_v6_check(struct sock *sk, struct sk_buff *skb) goto out; if (tcp_synq_no_recent_overflow(sk) || - (mss = cookie_check(skb, cookie)) == 0) { + (mss = __cookie_v6_check(ipv6_hdr(skb), th, cookie)) == 0) { NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_SYNCOOKIESFAILED); goto out; } -- 2.7.4