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authorGerrit Renker <gerrit@erg.abdn.ac.uk>2006-12-09 23:59:14 -0200
committerDavid S. Miller <davem@sunset.davemloft.net>2006-12-11 14:34:39 -0800
commit45393a66a2c30fc8ed86e6c79a63a3cd5231c69f (patch)
tree628feedd3d6d1fbdb1728d57e4bb62e1fc61e5c4 /net
parent5fce9a2da8a3b4ed088d9c0ac7c938a638044fdb (diff)
[DCCP] ccid3: Check against too large p
This patch follows a suggestion by Ian McDonald and ensures that in the current code the value of p can not exceed 100%. Such a value is illegal and would consequently cause a bug condition in tfrc_calc_x(). The receiver case is also tested, and a warning message is added. Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk> Acked-by: Ian McDonald <ian.mcdonald@jandi.co.nz> Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
Diffstat (limited to 'net')
-rw-r--r--net/dccp/ccids/ccid3.c13
1 files changed, 9 insertions, 4 deletions
diff --git a/net/dccp/ccids/ccid3.c b/net/dccp/ccids/ccid3.c
index 66a27b9688c..f1b745ee9cb 100644
--- a/net/dccp/ccids/ccid3.c
+++ b/net/dccp/ccids/ccid3.c
@@ -444,9 +444,9 @@ static void ccid3_hc_tx_packet_recv(struct sock *sk, struct sk_buff *skb)
/* Update loss event rate */
pinv = opt_recv->ccid3or_loss_event_rate;
- if (pinv == ~0U || pinv == 0)
+ if (pinv == ~0U || pinv == 0) /* see RFC 4342, 8.5 */
hctx->ccid3hctx_p = 0;
- else
+ else /* can not exceed 100% */
hctx->ccid3hctx_p = 1000000 / pinv;
dccp_timestamp(sk, &now);
@@ -733,10 +733,15 @@ static void ccid3_hc_rx_send_feedback(struct sock *sk)
/* Convert to multiples of 10us */
hcrx->ccid3hcrx_elapsed_time =
timeval_delta(&now, &packet->dccphrx_tstamp) / 10;
+
if (hcrx->ccid3hcrx_p == 0)
- hcrx->ccid3hcrx_pinv = ~0;
- else
+ hcrx->ccid3hcrx_pinv = ~0U; /* see RFC 4342, 8.5 */
+ else if (hcrx->ccid3hcrx_p > 1000000) {
+ DCCP_WARN("p (%u) > 100%%\n", hcrx->ccid3hcrx_p);
+ hcrx->ccid3hcrx_pinv = 1; /* use 100% in this case */
+ } else
hcrx->ccid3hcrx_pinv = 1000000 / hcrx->ccid3hcrx_p;
+
dp->dccps_hc_rx_insert_options = 1;
dccp_send_ack(sk);
}