- Update to 2.6.25-rc3.

[linux-flexiantxendom0-3.2.10.git] / net / dccp / output.c

diff --git a/net/dccp/output.c b/net/dccp/output.c
index f495446..3b763db 100644 (file)
--- a/net/dccp/output.c
+++ b/net/dccp/output.c
@@ -133,15 +133,31 @@ static int dccp_transmit_skb(struct sock *sk, struct sk_buff *skb)
        return -ENOBUFS;
 }
 
+/**
+ * dccp_determine_ccmps  -  Find out about CCID-specfic packet-size limits
+ * We only consider the HC-sender CCID for setting the CCMPS (RFC 4340, 14.),
+ * since the RX CCID is restricted to feedback packets (Acks), which are small
+ * in comparison with the data traffic. A value of 0 means "no current CCMPS".
+ */
+static u32 dccp_determine_ccmps(const struct dccp_sock *dp)
+{
+       const struct ccid *tx_ccid = dp->dccps_hc_tx_ccid;
+
+       if (tx_ccid == NULL || tx_ccid->ccid_ops == NULL)
+               return 0;
+       return tx_ccid->ccid_ops->ccid_ccmps;
+}
+
 unsigned int dccp_sync_mss(struct sock *sk, u32 pmtu)
 {
        struct inet_connection_sock *icsk = inet_csk(sk);
        struct dccp_sock *dp = dccp_sk(sk);
-       int mss_now = (pmtu - icsk->icsk_af_ops->net_header_len -
-                      sizeof(struct dccp_hdr) - sizeof(struct dccp_hdr_ext));
+       u32 ccmps = dccp_determine_ccmps(dp);
+       int cur_mps = ccmps ? min(pmtu, ccmps) : pmtu;
 
-       /* Now subtract optional transport overhead */
-       mss_now -= icsk->icsk_ext_hdr_len;
+       /* Account for header lengths and IPv4/v6 option overhead */
+       cur_mps -= (icsk->icsk_af_ops->net_header_len + icsk->icsk_ext_hdr_len +
+                   sizeof(struct dccp_hdr) + sizeof(struct dccp_hdr_ext));
 
        /*
         * FIXME: this should come from the CCID infrastructure, where, say,
@@ -151,13 +167,13 @@ unsigned int dccp_sync_mss(struct sock *sk, u32 pmtu)
         * make it a multiple of 4
         */
 
-       mss_now -= ((5 + 6 + 10 + 6 + 6 + 6 + 3) / 4) * 4;
+       cur_mps -= ((5 + 6 + 10 + 6 + 6 + 6 + 3) / 4) * 4;
 
        /* And store cached results */
        icsk->icsk_pmtu_cookie = pmtu;
-       dp->dccps_mss_cache = mss_now;
+       dp->dccps_mss_cache = cur_mps;
 
-       return mss_now;
+       return cur_mps;
 }
 
 EXPORT_SYMBOL_GPL(dccp_sync_mss);
@@ -170,7 +186,7 @@ void dccp_write_space(struct sock *sk)
                wake_up_interruptible(sk->sk_sleep);
        /* Should agree with poll, otherwise some programs break */
        if (sock_writeable(sk))
-               sk_wake_async(sk, 2, POLL_OUT);
+               sk_wake_async(sk, SOCK_WAKE_SPACE, POLL_OUT);
 
        read_unlock(&sk->sk_callback_lock);
 }
@@ -303,7 +319,7 @@ struct sk_buff *dccp_make_response(struct sock *sk, struct dst_entry *dst,
        DCCP_SKB_CB(skb)->dccpd_type = DCCP_PKT_RESPONSE;
        DCCP_SKB_CB(skb)->dccpd_seq  = dreq->dreq_iss;
 
-       if (dccp_insert_options(sk, skb)) {
+       if (dccp_insert_options_rsk(dreq, skb)) {
                kfree_skb(skb);
                return NULL;
        }
@@ -391,7 +407,7 @@ int dccp_send_reset(struct sock *sk, enum dccp_reset_codes code)
         * FIXME: what if rebuild_header fails?
         * Should we be doing a rebuild_header here?
         */
-       int err = inet_sk_rebuild_header(sk);
+       int err = inet_csk(sk)->icsk_af_ops->rebuild_header(sk);
 
        if (err != 0)
                return err;
@@ -567,14 +583,27 @@ void dccp_send_close(struct sock *sk, const int active)
 
        /* Reserve space for headers and prepare control bits. */
        skb_reserve(skb, sk->sk_prot->max_header);
-       DCCP_SKB_CB(skb)->dccpd_type = dp->dccps_role == DCCP_ROLE_CLIENT ?
-                                       DCCP_PKT_CLOSE : DCCP_PKT_CLOSEREQ;
+       if (dp->dccps_role == DCCP_ROLE_SERVER && !dp->dccps_server_timewait)
+               DCCP_SKB_CB(skb)->dccpd_type = DCCP_PKT_CLOSEREQ;
+       else
+               DCCP_SKB_CB(skb)->dccpd_type = DCCP_PKT_CLOSE;
 
        if (active) {
                dccp_write_xmit(sk, 1);
                dccp_skb_entail(sk, skb);
                dccp_transmit_skb(sk, skb_clone(skb, prio));
-               /* FIXME do we need a retransmit timer here? */
+               /*
+                * Retransmission timer for active-close: RFC 4340, 8.3 requires
+                * to retransmit the Close/CloseReq until the CLOSING/CLOSEREQ
+                * state can be left. The initial timeout is 2 RTTs.
+                * Since RTT measurement is done by the CCIDs, there is no easy
+                * way to get an RTT sample. The fallback RTT from RFC 4340, 3.4
+                * is too low (200ms); we use a high value to avoid unnecessary
+                * retransmissions when the link RTT is > 0.2 seconds.
+                * FIXME: Let main module sample RTTs and use that instead.
+                */
+               inet_csk_reset_xmit_timer(sk, ICSK_TIME_RETRANS,
+                                         DCCP_TIMEOUT_INIT, DCCP_RTO_MAX);
        } else
                dccp_transmit_skb(sk, skb);
 }