From ce177ae2e6b196659e93a9408cc1f5f13f206d13 Mon Sep 17 00:00:00 2001 From: Gerrit Renker Date: Thu, 4 Sep 2008 07:30:19 +0200 Subject: [PATCH] dccp ccid-3: Remove redundant 'options_received' struct The `options_received' struct is redundant, since it re-duplicates the existing `p' and `x_recv' fields. This patch removes the sub-struct and migrates the format conversion operations (cf. below) to ccid3_hc_tx_parse_options(). Why the fields are redundant ---------------------------- The Loss Event Rate p and the Receive Rate x_recv are initially 0 when first loading CCID-3, as ccid_new() zeroes out the entire ccid3_hc_tx_sock. When Loss Event Rate or Receive Rate options are received, they are stored by ccid3_hc_tx_parse_options() into the fields `ccid3or_loss_event_rate' and `ccid3or_receive_rate' of the sub-struct `options_received' in ccid3_hc_tx_sock. After parsing (considering only the established state - dccp_rcv_established()), the packet is passed on to ccid_hc_tx_packet_recv(). This calls the CCID-3 specific routine ccid3_hc_tx_packet_recv(), which performs the following copy operations between fields of ccid3_hc_tx_sock: * hctx->options_received.ccid3or_receive_rate is copied into hctx->x_recv, after scaling it for fixpoint arithmetic, by 2^64; * hctx->options_received.ccid3or_loss_event_rate is copied into hctx->p, considering the above special cases; in addition, a value of 0 here needs to be mapped into p=0 (when no Loss Event Rate option has been received yet). Signed-off-by: Gerrit Renker --- net/dccp/ccids/ccid3.c | 24 ++++++++---------------- net/dccp/ccids/ccid3.h | 7 ------- 2 files changed, 8 insertions(+), 23 deletions(-) diff --git a/net/dccp/ccids/ccid3.c b/net/dccp/ccids/ccid3.c index 206204551f4d..e7db8a4ee642 100644 --- a/net/dccp/ccids/ccid3.c +++ b/net/dccp/ccids/ccid3.c @@ -370,11 +370,10 @@ static void ccid3_hc_tx_packet_sent(struct sock *sk, int more, static void ccid3_hc_tx_packet_recv(struct sock *sk, struct sk_buff *skb) { struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk); - struct ccid3_options_received *opt_recv = &hctx->options_received; struct tfrc_tx_hist_entry *acked; ktime_t now; unsigned long t_nfb; - u32 pinv, r_sample; + u32 r_sample; /* we are only interested in ACKs */ if (!(DCCP_SKB_CB(skb)->dccpd_type == DCCP_PKT_ACK || @@ -404,17 +403,6 @@ static void ccid3_hc_tx_packet_recv(struct sock *sk, struct sk_buff *skb) r_sample = dccp_sample_rtt(sk, ktime_us_delta(now, acked->stamp)); hctx->rtt = tfrc_ewma(hctx->rtt, r_sample, 9); - /* Update receive rate in units of 64 * bytes/second */ - hctx->x_recv = opt_recv->ccid3or_receive_rate; - hctx->x_recv <<= 6; - - /* Update loss event rate (which is scaled by 1e6) */ - pinv = opt_recv->ccid3or_loss_event_rate; - if (pinv == 0) - hctx->p = 0; - else - hctx->p = tfrc_invert_loss_event_rate(pinv); - /* * Update allowed sending rate X as per draft rfc3448bis-00, 4.2/3 */ @@ -487,7 +475,6 @@ static int ccid3_hc_tx_parse_options(struct sock *sk, u8 packet_type, u8 option, u8 *optval, u8 optlen) { struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk); - struct ccid3_options_received *opt_recv = &hctx->options_received; __be32 opt_val; switch (option) { @@ -504,11 +491,16 @@ static int ccid3_hc_tx_parse_options(struct sock *sk, u8 packet_type, opt_val = ntohl(get_unaligned((__be32 *)optval)); if (option == TFRC_OPT_RECEIVE_RATE) { - opt_recv->ccid3or_receive_rate = opt_val; + /* Receive Rate is kept in units of 64 bytes/second */ + hctx->x_recv = opt_val; + hctx->x_recv <<= 6; + ccid3_pr_debug("%s(%p), RECEIVE_RATE=%u\n", dccp_role(sk), sk, opt_val); } else { - opt_recv->ccid3or_loss_event_rate = opt_val; + /* Update the fixpoint Loss Event Rate fraction */ + hctx->p = tfrc_invert_loss_event_rate(opt_val); + ccid3_pr_debug("%s(%p), LOSS_EVENT_RATE=%u\n", dccp_role(sk), sk, opt_val); } diff --git a/net/dccp/ccids/ccid3.h b/net/dccp/ccids/ccid3.h index 2268785ae8ee..ae210786c895 100644 --- a/net/dccp/ccids/ccid3.h +++ b/net/dccp/ccids/ccid3.h @@ -70,11 +70,6 @@ enum ccid3_options { TFRC_OPT_RECEIVE_RATE = 194, }; -struct ccid3_options_received { - u32 ccid3or_loss_event_rate; - u32 ccid3or_receive_rate; -}; - /* TFRC sender states */ enum ccid3_hc_tx_states { TFRC_SSTATE_NO_SENT = 1, @@ -101,7 +96,6 @@ enum ccid3_hc_tx_states { * @t_ld - Time last doubled during slow start * @t_nom - Nominal send time of next packet * @hist - Packet history - * @options_received - Parsed set of retrieved options */ struct ccid3_hc_tx_sock { u64 x; @@ -119,7 +113,6 @@ struct ccid3_hc_tx_sock { ktime_t t_ld; ktime_t t_nom; struct tfrc_tx_hist_entry *hist; - struct ccid3_options_received options_received; }; static inline struct ccid3_hc_tx_sock *ccid3_hc_tx_sk(const struct sock *sk) -- 2.39.2