From 050e3987f7305a77dcec58bbf5391993d75735b2 Mon Sep 17 00:00:00 2001 From: Gerrit Renker Date: Thu, 4 Sep 2008 07:30:19 +0200 Subject: [PATCH] --- yaml --- r: 111517 b: refs/heads/master c: c2f42077bd06f300ae959204f3c007f820f5e769 h: refs/heads/master i: 111515: a8765c389776635bd21dc88883d2cd1725fd35c3 v: v3 --- [refs] | 2 +- trunk/include/linux/dccp.h | 2 ++ trunk/net/dccp/options.c | 24 ++++++++++++++++++++---- trunk/net/dccp/output.c | 8 ++++++++ 4 files changed, 31 insertions(+), 5 deletions(-) diff --git a/[refs] b/[refs] index 776ddae835c8..b7df7fc18bbe 100644 --- a/[refs] +++ b/[refs] @@ -1,2 +1,2 @@ --- -refs/heads/master: 283fb4a5f39d1521d53e1044bff0ba2654acf145 +refs/heads/master: c2f42077bd06f300ae959204f3c007f820f5e769 diff --git a/trunk/include/linux/dccp.h b/trunk/include/linux/dccp.h index 7187bd8a75f6..83197b601a4f 100644 --- a/trunk/include/linux/dccp.h +++ b/trunk/include/linux/dccp.h @@ -462,6 +462,7 @@ struct dccp_ackvec; * @dccps_hc_rx_insert_options - receiver wants to add options when acking * @dccps_hc_tx_insert_options - sender wants to add options when sending * @dccps_server_timewait - server holds timewait state on close (RFC 4340, 8.3) + * @dccps_sync_scheduled - flag which signals "send out-of-band message soon" * @dccps_xmit_timer - timer for when CCID is not ready to send * @dccps_syn_rtt - RTT sample from Request/Response exchange (in usecs) */ @@ -502,6 +503,7 @@ struct dccp_sock { __u8 dccps_hc_rx_insert_options:1; __u8 dccps_hc_tx_insert_options:1; __u8 dccps_server_timewait:1; + __u8 dccps_sync_scheduled:1; struct timer_list dccps_xmit_timer; }; diff --git a/trunk/net/dccp/options.c b/trunk/net/dccp/options.c index b11d7b7167f0..791e07853a79 100644 --- a/trunk/net/dccp/options.c +++ b/trunk/net/dccp/options.c @@ -430,6 +430,7 @@ static int dccp_insert_option_ackvec(struct sock *sk, struct sk_buff *skb) { struct dccp_sock *dp = dccp_sk(sk); struct dccp_ackvec *av = dp->dccps_hc_rx_ackvec; + struct dccp_skb_cb *dcb = DCCP_SKB_CB(skb); const u16 buflen = dccp_ackvec_buflen(av); /* Figure out how many options do we need to represent the ackvec */ const u8 nr_opts = DIV_ROUND_UP(buflen, DCCP_SINGLE_OPT_MAXLEN); @@ -438,10 +439,25 @@ static int dccp_insert_option_ackvec(struct sock *sk, struct sk_buff *skb) const unsigned char *tail, *from; unsigned char *to; - if (DCCP_SKB_CB(skb)->dccpd_opt_len + len > DCCP_MAX_OPT_LEN) + if (dcb->dccpd_opt_len + len > DCCP_MAX_OPT_LEN) { + DCCP_WARN("Lacking space for %u bytes on %s packet\n", len, + dccp_packet_name(dcb->dccpd_type)); return -1; - - DCCP_SKB_CB(skb)->dccpd_opt_len += len; + } + /* + * Since Ack Vectors are variable-length, we can not always predict + * their size. To catch exception cases where the space is running out + * on the skb, a separate Sync is scheduled to carry the Ack Vector. + */ + if (len > DCCPAV_MIN_OPTLEN && + len + dcb->dccpd_opt_len + skb->len > dp->dccps_mss_cache) { + DCCP_WARN("No space left for Ack Vector (%u) on skb (%u+%u), " + "MPS=%u ==> reduce payload size?\n", len, skb->len, + dcb->dccpd_opt_len, dp->dccps_mss_cache); + dp->dccps_sync_scheduled = 1; + return 0; + } + dcb->dccpd_opt_len += len; to = skb_push(skb, len); len = buflen; @@ -482,7 +498,7 @@ static int dccp_insert_option_ackvec(struct sock *sk, struct sk_buff *skb) /* * Each sent Ack Vector is recorded in the list, as per A.2 of RFC 4340. */ - if (dccp_ackvec_update_records(av, DCCP_SKB_CB(skb)->dccpd_seq, nonce)) + if (dccp_ackvec_update_records(av, dcb->dccpd_seq, nonce)) return -ENOBUFS; return 0; } diff --git a/trunk/net/dccp/output.c b/trunk/net/dccp/output.c index 1b3168307586..bfda071559f4 100644 --- a/trunk/net/dccp/output.c +++ b/trunk/net/dccp/output.c @@ -305,6 +305,8 @@ void dccp_write_xmit(struct sock *sk, int block) if (err) DCCP_BUG("err=%d after ccid_hc_tx_packet_sent", err); + if (dp->dccps_sync_scheduled) + dccp_send_sync(sk, dp->dccps_gsr, DCCP_PKT_SYNC); } else { dccp_pr_debug("packet discarded due to err=%d\n", err); kfree_skb(skb); @@ -591,6 +593,12 @@ void dccp_send_sync(struct sock *sk, const u64 ackno, DCCP_SKB_CB(skb)->dccpd_type = pkt_type; DCCP_SKB_CB(skb)->dccpd_ack_seq = ackno; + /* + * Clear the flag in case the Sync was scheduled for out-of-band data, + * such as carrying a long Ack Vector. + */ + dccp_sk(sk)->dccps_sync_scheduled = 0; + dccp_transmit_skb(sk, skb); }