diff options
| author |   Patrick McHardy <kaber@trash.net> | 2013-08-27 08:50:13 +0200 |
|---|---|---|
| committer |   Pablo Neira Ayuso <pablo@netfilter.org> | 2013-08-28 00:27:44 +0200 |
| commit | 0198230b7705eb2386e53778d944e307eef0cc71 (patch) | |
| tree | 0f1a970873df8a3dd3c1111020b6555e8f8d0518 /net/ipv4 | |
| parent | netfilter: nf_conntrack: make sequence number adjustments usuable without NAT (diff) | |
| download | linux-dev-0198230b7705eb2386e53778d944e307eef0cc71.tar.xz linux-dev-0198230b7705eb2386e53778d944e307eef0cc71.zip | |
net: syncookies: export cookie_v4_init_sequence/cookie_v4_check
Extract the local TCP stack independant parts of tcp_v4_init_sequence()
and cookie_v4_check() and export them for use by the upcoming SYNPROXY
target.
Signed-off-by: Patrick McHardy <kaber@trash.net>
Acked-by: David S. Miller <davem@davemloft.net>
Tested-by: Martin Topholm <mph@one.com>
Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Diffstat (limited to 'net/ipv4')
| -rw-r--r-- | net/ipv4/syncookies.c | 29 |
1 files changed, 18 insertions, 11 deletions
diff --git a/net/ipv4/syncookies.c b/net/ipv4/syncookies.c index b05c96e7af8b..14a15c49129d 100644 --- a/net/ipv4/syncookies.c +++ b/net/ipv4/syncookies.c @@ -160,26 +160,33 @@ static __u16 const msstab[] = { * Generate a syncookie. mssp points to the mss, which is returned * rounded down to the value encoded in the cookie. */ -__u32 cookie_v4_init_sequence(struct sock *sk, struct sk_buff *skb, __u16 *mssp) +u32 __cookie_v4_init_sequence(const struct iphdr *iph, const struct tcphdr *th, + u16 *mssp) { - const struct iphdr *iph = ip_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_v4_init_sequence); + +__u32 cookie_v4_init_sequence(struct sock *sk, struct sk_buff *skb, __u16 *mssp) +{ + const struct iphdr *iph = ip_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_v4_init_sequence(iph, th, mssp); +} /* * This (misnamed) value is the age of syncookie which is permitted. @@ -192,10 +199,9 @@ __u32 cookie_v4_init_sequence(struct sock *sk, struct sk_buff *skb, __u16 *mssp) * Check if a ack sequence number is a valid syncookie. * Return the decoded mss if it is, or 0 if not. */ -static inline int cookie_check(struct sk_buff *skb, __u32 cookie) +int __cookie_v4_check(const struct iphdr *iph, const struct tcphdr *th, + u32 cookie) { - const struct iphdr *iph = ip_hdr(skb); - const struct tcphdr *th = tcp_hdr(skb); __u32 seq = ntohl(th->seq) - 1; __u32 mssind = check_tcp_syn_cookie(cookie, iph->saddr, iph->daddr, th->source, th->dest, seq, @@ -204,6 +210,7 @@ static inline int cookie_check(struct sk_buff *skb, __u32 cookie) return mssind < ARRAY_SIZE(msstab) ? msstab[mssind] : 0; } +EXPORT_SYMBOL_GPL(__cookie_v4_check); static inline struct sock *get_cookie_sock(struct sock *sk, struct sk_buff *skb, struct request_sock *req, @@ -284,7 +291,7 @@ struct sock *cookie_v4_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_v4_check(ip_hdr(skb), th, cookie)) == 0) { NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_SYNCOOKIESFAILED); goto out; } |