From: Gerrit Renker Date: Sun, 3 Dec 2006 16:50:42 +0000 (-0200) Subject: [DCCP]: Fix BUG in retransmission delay calculation X-Git-Tag: firefly_0821_release~30985^2~47^2~114^2~1^2~8 X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=76d127779e51fbf67ad6793214369aa1fea90278;p=firefly-linux-kernel-4.4.55.git [DCCP]: Fix BUG in retransmission delay calculation This bug resulted in ccid3_hc_tx_send_packet returning negative delay values, which in turn triggered silently dequeueing packets in dccp_write_xmit. As a result, only a few out of the submitted packets made it at all onto the network. Occasionally, when dccp_wait_for_ccid was involved, this also triggered a bug warning since ccid3_hc_tx_send_packet returned a negative value (which in reality was a negative delay value). The cause for this bug lies in the comparison if (delay >= hctx->ccid3hctx_delta) return delay / 1000L; The type of `delay' is `long', that of ccid3hctx_delta is `u32'. When comparing negative long values against u32 values, the test returned `true' whenever delay was smaller than 0 (meaning the packet was overdue to send). The fix is by casting, subtracting, and then testing the difference with regard to 0. This has been tested and shown to work. Signed-off-by: Gerrit Renker Signed-off-by: Ian McDonald Signed-off-by: Arnaldo Carvalho de Melo --- diff --git a/net/dccp/ccids/ccid3.c b/net/dccp/ccids/ccid3.c index 99807783a22f..22a07248c240 100644 --- a/net/dccp/ccids/ccid3.c +++ b/net/dccp/ccids/ccid3.c @@ -339,7 +339,7 @@ static int ccid3_hc_tx_send_packet(struct sock *sk, struct sk_buff *skb) * else * // send the packet in (t_nom - t_now) milliseconds. */ - if (delay >= hctx->ccid3hctx_delta) + if (delay - (long)hctx->ccid3hctx_delta >= 0) return delay / 1000L; break; case TFRC_SSTATE_TERM: