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 <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>
This commit is contained in:
Patrick McHardy 2013-08-27 08:50:15 +02:00 committed by Pablo Neira Ayuso
parent 48b1de4c11
commit 81eb6a1487
2 changed files with 20 additions and 9 deletions

View File

@ -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

View File

@ -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;
}