Commit 37efb03f authored by Gerrit Renker's avatar Gerrit Renker
Browse files

dccp ccid-3: Simplify and consolidate tx_parse_options 



This simplifies and consolidates the TX option-parsing code:

 1. The Loss Intervals option is not currently used, so dead code related to
    this option is removed. I am aware of no plans to support the option, but
    if someone wants to implement it (e.g. for inter-op tests), it is better
    to start afresh than having to also update currently unused code.

 2. The Loss Event and Receive Rate options have a lot of code in common (both
    are 32 bit, both have same length etc.), so this is consolidated.

 3. The test against GSR is not necessary, because
    - on first loading CCID3, ccid_new() zeroes out all fields in the socket;
    - ccid3_hc_tx_packet_recv() treats 0 and ~0U equivalently, due to

	pinv = opt_recv->ccid3or_loss_event_rate;
	if (pinv == ~0U || pinv == 0)
		hctx->p = 0;

    - as a result, the sequence number field is removed from opt_recv.

Signed-off-by: default avatarGerrit Renker <gerrit@erg.abdn.ac.uk>
parent d2c72630

net/dccp/ccids/ccid3.c

+14 −43
Original line number Diff line number Diff line
@@ -485,60 +485,31 @@ static int ccid3_hc_tx_parse_options(struct sock *sk, unsigned char option, 
				     unsigned char len, u16 idx,

				     unsigned char *value)

{

	int rc = 0;

	const struct dccp_sock *dp = dccp_sk(sk);

	struct ccid3_hc_tx_sock *hc = ccid3_hc_tx_sk(sk);

	struct ccid3_options_received *opt_recv = &hc->tx_options_received;

	__be32 opt_val;



	if (opt_recv->ccid3or_seqno != dp->dccps_gsr) {

		opt_recv->ccid3or_seqno		     = dp->dccps_gsr;

		opt_recv->ccid3or_loss_event_rate    = ~0;

		opt_recv->ccid3or_loss_intervals_idx = 0;

		opt_recv->ccid3or_loss_intervals_len = 0;

		opt_recv->ccid3or_receive_rate	     = 0;

	}



	switch (option) {

	case TFRC_OPT_RECEIVE_RATE:

	case TFRC_OPT_LOSS_EVENT_RATE:

		if (unlikely(len != 4)) {

			DCCP_WARN("%s(%p), invalid len %d "

				  "for TFRC_OPT_LOSS_EVENT_RATE\n",

				  dccp_role(sk), sk, len);

			rc = -EINVAL;

		} else {

			opt_val = get_unaligned((__be32 *)value);

			opt_recv->ccid3or_loss_event_rate = ntohl(opt_val);

			ccid3_pr_debug("%s(%p), LOSS_EVENT_RATE=%u\n",

				       dccp_role(sk), sk,

				       opt_recv->ccid3or_loss_event_rate);

			DCCP_WARN("%s(%p), invalid len %d for %u\n",

				  dccp_role(sk), sk, len, option);

			return -EINVAL;

		}

		break;

	case TFRC_OPT_LOSS_INTERVALS:

		opt_recv->ccid3or_loss_intervals_idx = idx;

		opt_recv->ccid3or_loss_intervals_len = len;

		ccid3_pr_debug("%s(%p), LOSS_INTERVALS=(%u, %u)\n",

			       dccp_role(sk), sk,

			       opt_recv->ccid3or_loss_intervals_idx,

			       opt_recv->ccid3or_loss_intervals_len);

		break;

	case TFRC_OPT_RECEIVE_RATE:

		if (unlikely(len != 4)) {

			DCCP_WARN("%s(%p), invalid len %d "

				  "for TFRC_OPT_RECEIVE_RATE\n",

				  dccp_role(sk), sk, len);

			rc = -EINVAL;

		} else {

			opt_val = get_unaligned((__be32 *)value);

			opt_recv->ccid3or_receive_rate = ntohl(opt_val);

		opt_val = ntohl(get_unaligned((__be32 *)value));



		if (option == TFRC_OPT_RECEIVE_RATE) {

			opt_recv->ccid3or_receive_rate = opt_val;

			ccid3_pr_debug("%s(%p), RECEIVE_RATE=%u\n",

				       dccp_role(sk), sk,

				       opt_recv->ccid3or_receive_rate);

				       dccp_role(sk), sk, opt_val);

		} else {

			opt_recv->ccid3or_loss_event_rate = opt_val;

			ccid3_pr_debug("%s(%p), LOSS_EVENT_RATE=%u\n",

				       dccp_role(sk), sk, opt_val);

		}

		break;

	}



	return rc;

	return 0;

}



static int ccid3_hc_tx_init(struct ccid *ccid, struct sock *sk)

net/dccp/ccids/ccid3.h

+0 −3
Original line number Diff line number Diff line
@@ -68,9 +68,6 @@ enum ccid3_options { 
};



struct ccid3_options_received {

	u64 ccid3or_seqno:48,

	    ccid3or_loss_intervals_idx:16;

	u16 ccid3or_loss_intervals_len;

	u32 ccid3or_loss_event_rate;

	u32 ccid3or_receive_rate;

};

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