kernel-hacking-2024-linux-s.../net/dccp/ccids
Gerrit Renker 76d127779e [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 <gerrit@erg.abdn.ac.uk>
Signed-off-by: Ian McDonald <ian.mcdonald@jandi.co.nz>
Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
2006-12-03 14:50:42 -02:00
..
lib [DCCP]: Simplified conditions due to use of enum:8 states 2006-12-02 21:24:38 -08:00
ccid2.c [DCCP]: Use `unsigned' for packet lengths 2006-12-02 21:31:02 -08:00
ccid2.h [DCCP] ccid2: Allow window to grow larger 2006-12-02 21:30:34 -08:00
ccid3.c [DCCP]: Fix BUG in retransmission delay calculation 2006-12-03 14:50:42 -02:00
ccid3.h [DCCP] ccid3: Larger initial windows 2006-12-02 21:31:01 -08:00
Kconfig [DCCP]: Use higher RTO default for CCID3 2006-12-03 14:50:23 -02:00
Makefile