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 <kaber@xxxxxxxxx>
---
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 63256c6..22872c7 100644
--- a/include/net/tcp.h
+++ b/include/net/tcp.h
@@ -503,8 +503,12 @@ 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;
}
--
1.8.1.4
--
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