From 45393a66a2c30fc8ed86e6c79a63a3cd5231c69f Mon Sep 17 00:00:00 2001 From: Gerrit Renker Date: Sat, 9 Dec 2006 23:59:14 -0200 Subject: [PATCH] [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 Acked-by: Ian McDonald Signed-off-by: Arnaldo Carvalho de Melo --- net/dccp/ccids/ccid3.c | 13 +++++++++---- 1 file changed, 9 insertions(+), 4 deletions(-) diff --git a/net/dccp/ccids/ccid3.c b/net/dccp/ccids/ccid3.c index 66a27b9688..f1b745ee9c 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); } -- 2.39.5