syncookies: update mss tables
- ipv6 msstab: account for ipv6 header size
- ipv4 msstab: add mss for Jumbograms.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv6/syncookies.c b/net/ipv6/syncookies.c
index 9fcb3ec..70d330f 100644
--- a/net/ipv6/syncookies.c
+++ b/net/ipv6/syncookies.c
@@ -27,28 +27,17 @@
#define COOKIEBITS 24 /* Upper bits store count */
#define COOKIEMASK (((__u32)1 << COOKIEBITS) - 1)
-/*
- * This table has to be sorted and terminated with (__u16)-1.
- * XXX generate a better table.
- * Unresolved Issues: HIPPI with a 64k MSS is not well supported.
- *
- * Taken directly from ipv4 implementation.
- * Should this list be modified for ipv6 use or is it close enough?
- * rfc 2460 8.3 suggests mss values 20 bytes less than ipv4 counterpart
- */
+/* Table must be sorted. */
static __u16 const msstab[] = {
- 64 - 1,
- 256 - 1,
- 512 - 1,
- 536 - 1,
- 1024 - 1,
- 1440 - 1,
- 1460 - 1,
- 4312 - 1,
- (__u16)-1
+ 64,
+ 512,
+ 536,
+ 1280 - 60,
+ 1480 - 60,
+ 1500 - 60,
+ 4460 - 60,
+ 9000 - 60,
};
-/* The number doesn't include the -1 terminator */
-#define NUM_MSS (ARRAY_SIZE(msstab) - 1)
/*
* This (misnamed) value is the age of syncookie which is permitted.
@@ -134,9 +123,11 @@
tcp_synq_overflow(sk);
- for (mssind = 0; mss > msstab[mssind + 1]; mssind++)
- ;
- *mssp = msstab[mssind] + 1;
+ 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);
@@ -154,7 +145,7 @@
th->source, th->dest, seq,
jiffies / (HZ * 60), COUNTER_TRIES);
- return mssind < NUM_MSS ? msstab[mssind] + 1 : 0;
+ return mssind < ARRAY_SIZE(msstab) ? msstab[mssind] : 0;
}
struct sock *cookie_v6_check(struct sock *sk, struct sk_buff *skb)
