1 files changed, 22 insertions, 36 deletions

diff --git a/net/ipv6/syncookies.c b/net/ipv6/syncookies.c
index 34d1f0690d7e..09fd34f0dbf2 100644
--- a/net/ipv6/syncookies.c
+++ b/net/ipv6/syncookies.c
@@ -27,28 +27,17 @@ extern __u32 syncookie_secret[2][16-4+SHA_DIGEST_WORDS];
 #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 @@ __u32 cookie_v6_init_sequence(struct sock *sk, struct sk_buff *skb, __u16 *mssp)
 
         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 @@ static inline int cookie_check(struct sk_buff *skb, __u32 cookie)
                                             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)
@@ -173,8 +164,9 @@ struct sock *cookie_v6_check(struct sock *sk, struct sk_buff *skb)
         int mss;
         struct dst_entry *dst;
         __u8 rcv_wscale;
+        bool ecn_ok;
 
-        if (!sysctl_tcp_syncookies || !th->ack)
+        if (!sysctl_tcp_syncookies || !th->ack || th->rst)
                 goto out;
 
         if (tcp_synq_no_recent_overflow(sk) ||
@@ -189,8 +181,8 @@ struct sock *cookie_v6_check(struct sock *sk, struct sk_buff *skb)
         memset(&tcp_opt, 0, sizeof(tcp_opt));
         tcp_parse_options(skb, &tcp_opt, &hash_location, 0);
 
-        if (tcp_opt.saw_tstamp)
-                cookie_check_timestamp(&tcp_opt);
+        if (!cookie_check_timestamp(&tcp_opt, &ecn_ok))
+                goto out;
 
         ret = NULL;
         req = inet6_reqsk_alloc(&tcp6_request_sock_ops);
@@ -224,9 +216,8 @@ struct sock *cookie_v6_check(struct sock *sk, struct sk_buff *skb)
 
         req->expires = 0UL;
         req->retrans = 0;
-        ireq->ecn_ok            = 0;
+        ireq->ecn_ok            = ecn_ok;
         ireq->snd_wscale        = tcp_opt.snd_wscale;
-        ireq->rcv_wscale        = tcp_opt.rcv_wscale;
         ireq->sack_ok           = tcp_opt.sack_ok;
         ireq->wscale_ok         = tcp_opt.wscale_ok;
         ireq->tstamp_ok         = tcp_opt.saw_tstamp;
@@ -240,17 +231,12 @@ struct sock *cookie_v6_check(struct sock *sk, struct sk_buff *skb)
          * me if there is a preferred way.
          */
         {
-                struct in6_addr *final_p = NULL, final;
+                struct in6_addr *final_p, final;
                 struct flowi fl;
                 memset(&fl, 0, sizeof(fl));
                 fl.proto = IPPROTO_TCP;
                 ipv6_addr_copy(&fl.fl6_dst, &ireq6->rmt_addr);
-                if (np->opt && np->opt->srcrt) {
-                        struct rt0_hdr *rt0 = (struct rt0_hdr *) np->opt->srcrt;
-                        ipv6_addr_copy(&final, &fl.fl6_dst);
-                        ipv6_addr_copy(&fl.fl6_dst, rt0->addr);
-                        final_p = &final;
-                }
+                final_p = fl6_update_dst(&fl, np->opt, &final);
                 ipv6_addr_copy(&fl.fl6_src, &ireq6->loc_addr);
                 fl.oif = sk->sk_bound_dev_if;
                 fl.mark = sk->sk_mark;