Merge branch 'net-next-2.6-misc-20080612a' of git://git.linux-ipv6.org/gitroot/yoshfu...

[mirror_ubuntu-bionic-kernel.git] / net / ipv4 / tcp_input.c

diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index b54d9d37b636a79b26de0f0ee36e9f6024ba453e..bc7f62e2792b4039e6b6f033696a0263f5cb1a8f 100644 (file)
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -5,8 +5,6 @@
  *
  *             Implementation of the Transmission Control Protocol(TCP).
  *
- * Version:    $Id: tcp_input.c,v 1.243 2002/02/01 22:01:04 davem Exp $
- *
  * Authors:    Ross Biro
  *             Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
  *             Mark Evans, <evansmp@uhura.aston.ac.uk>
@@ -1392,9 +1390,9 @@ static struct sk_buff *tcp_maybe_skipping_dsack(struct sk_buff *skb,
 
        if (before(next_dup->start_seq, skip_to_seq)) {
                skb = tcp_sacktag_skip(skb, sk, next_dup->start_seq, fack_count);
-               tcp_sacktag_walk(skb, sk, NULL,
-                                next_dup->start_seq, next_dup->end_seq,
-                                1, fack_count, reord, flag);
+               skb = tcp_sacktag_walk(skb, sk, NULL,
+                                    next_dup->start_seq, next_dup->end_seq,
+                                    1, fack_count, reord, flag);
        }
 
        return skb;
@@ -2483,6 +2481,20 @@ static inline void tcp_complete_cwr(struct sock *sk)
        tcp_ca_event(sk, CA_EVENT_COMPLETE_CWR);
 }
 
+static void tcp_try_keep_open(struct sock *sk)
+{
+       struct tcp_sock *tp = tcp_sk(sk);
+       int state = TCP_CA_Open;
+
+       if (tcp_left_out(tp) || tp->retrans_out || tp->undo_marker)
+               state = TCP_CA_Disorder;
+
+       if (inet_csk(sk)->icsk_ca_state != state) {
+               tcp_set_ca_state(sk, state);
+               tp->high_seq = tp->snd_nxt;
+       }
+}
+
 static void tcp_try_to_open(struct sock *sk, int flag)
 {
        struct tcp_sock *tp = tcp_sk(sk);
@@ -2496,15 +2508,7 @@ static void tcp_try_to_open(struct sock *sk, int flag)
                tcp_enter_cwr(sk, 1);
 
        if (inet_csk(sk)->icsk_ca_state != TCP_CA_CWR) {
-               int state = TCP_CA_Open;
-
-               if (tcp_left_out(tp) || tp->retrans_out || tp->undo_marker)
-                       state = TCP_CA_Disorder;
-
-               if (inet_csk(sk)->icsk_ca_state != state) {
-                       tcp_set_ca_state(sk, state);
-                       tp->high_seq = tp->snd_nxt;
-               }
+               tcp_try_keep_open(sk);
                tcp_moderate_cwnd(tp);
        } else {
                tcp_cwnd_down(sk, flag);
@@ -3310,8 +3314,11 @@ no_queue:
        return 1;
 
 old_ack:
-       if (TCP_SKB_CB(skb)->sacked)
+       if (TCP_SKB_CB(skb)->sacked) {
                tcp_sacktag_write_queue(sk, skb, prior_snd_una);
+               if (icsk->icsk_ca_state == TCP_CA_Open)
+                       tcp_try_keep_open(sk);
+       }
 
 uninteresting_ack:
        SOCK_DEBUG(sk, "Ack %u out of %u:%u\n", ack, tp->snd_una, tp->snd_nxt);
@@ -3441,6 +3448,43 @@ static int tcp_fast_parse_options(struct sk_buff *skb, struct tcphdr *th,
        return 1;
 }
 
+#ifdef CONFIG_TCP_MD5SIG
+/*
+ * Parse MD5 Signature option
+ */
+u8 *tcp_parse_md5sig_option(struct tcphdr *th)
+{
+       int length = (th->doff << 2) - sizeof (*th);
+       u8 *ptr = (u8*)(th + 1);
+
+       /* If the TCP option is too short, we can short cut */
+       if (length < TCPOLEN_MD5SIG)
+               return NULL;
+
+       while (length > 0) {
+               int opcode = *ptr++;
+               int opsize;
+
+               switch(opcode) {
+               case TCPOPT_EOL:
+                       return NULL;
+               case TCPOPT_NOP:
+                       length--;
+                       continue;
+               default:
+                       opsize = *ptr++;
+                       if (opsize < 2 || opsize > length)
+                               return NULL;
+                       if (opcode == TCPOPT_MD5SIG)
+                               return ptr;
+               }
+               ptr += opsize - 2;
+               length -= opsize;
+       }
+       return NULL;
+}
+#endif
+
 static inline void tcp_store_ts_recent(struct tcp_sock *tp)
 {
        tp->rx_opt.ts_recent = tp->rx_opt.rcv_tsval;
@@ -5458,6 +5502,9 @@ EXPORT_SYMBOL(sysctl_tcp_ecn);
 EXPORT_SYMBOL(sysctl_tcp_reordering);
 EXPORT_SYMBOL(sysctl_tcp_adv_win_scale);
 EXPORT_SYMBOL(tcp_parse_options);
+#ifdef CONFIG_TCP_MD5SIG
+EXPORT_SYMBOL(tcp_parse_md5sig_option);
+#endif
 EXPORT_SYMBOL(tcp_rcv_established);
 EXPORT_SYMBOL(tcp_rcv_state_process);
 EXPORT_SYMBOL(tcp_initialize_rcv_mss);