diff options
| author | Gerrit Renker <gerrit@erg.abdn.ac.uk> | 2006-11-27 12:26:57 -0200 |
|---|---|---|
| committer | David S. Miller <davem@sunset.davemloft.net> | 2006-12-02 21:30:39 -0800 |
| commit | da335baf9e788edfb00ee3b96f7b9526b6b2f8a9 (patch) | |
| tree | 1eea49e2f94f359d9293025c64f381d43dd5922f | |
| parent | 7da7f456d7bc0e52009f882e8af0ac910293e157 (diff) | |
[DCCP] ccid3: Avoid congestion control on zero-sized data packets
This resolves an `XXX' in ccid3_hc_tx_send_packet().
The function is only called on Data and DataAck packets and returns a negative
result on zero-sized messages. This is a reasonable policy since CCID 3 is a
congestion-control module and congestion control on zero-sized Data(Ack)
packets is in a way pathological.
The patch uses a more suitable error code for this case, it returns the Posix.1
code `EBADMSG' ("Not a data message") instead of `ENOTCONN'.
As a result of ignoring zero-sized packets, a the condition for a warning
"First packet is data" in ccid3_hc_tx_packet_sent is always satisfied; this
message has been removed since it will always be printed.
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>
| -rw-r--r-- | net/dccp/ccids/ccid3.c | 14 |
1 files changed, 5 insertions, 9 deletions
diff --git a/net/dccp/ccids/ccid3.c b/net/dccp/ccids/ccid3.c index 2745d835f037..62c304200eda 100644 --- a/net/dccp/ccids/ccid3.c +++ b/net/dccp/ccids/ccid3.c @@ -264,13 +264,13 @@ static int ccid3_hc_tx_send_packet(struct sock *sk, BUG_ON(hctx == NULL); - /* Check if pure ACK or Terminating*/ /* - * XXX: We only call this function for DATA and DATAACK, on, these - * packets can have zero length, but why the comment about "pure ACK"? + * This function is called only for Data and DataAck packets. Sending + * zero-sized Data(Ack)s is theoretically possible, but for congestion + * control this case is pathological - ignore it. */ if (unlikely(len == 0)) - return -ENOTCONN; + return -EBADMSG; /* See if last packet allocated was not sent */ new_packet = dccp_tx_hist_head(&hctx->ccid3hctx_hist); @@ -387,11 +387,7 @@ static void ccid3_hc_tx_packet_sent(struct sock *sk, int more, int len) switch (hctx->ccid3hctx_state) { case TFRC_SSTATE_NO_SENT: - /* if first wasn't pure ack */ - if (len != 0) - DCCP_CRIT("%s, First packet sent is noted " - "as a data packet", dccp_role(sk)); - return; + /* fall through */ case TFRC_SSTATE_NO_FBACK: /* t_nom, t_ipi, delta do not change until feedback arrives */ return; |