[DCCP] ccid3: Fix two bugs in sending rate computation (179ebc9f) · Commits · 戴 / test

This fixes 1) a bug in the recomputation of the sending rate by the nofeedback timer when no feedback at all has so far been sent by the receiver: min_t was used instead of max_t, which is wrong (cf. RFC 3448, p. 10); 2) an error in the computation of larger initial windows: instead of min(... max()) (cf. RFC 4342, 5.), the code had used max(... max()). 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>

net/dccp/ccids/ccid3.c

+2 −2

Original line number	Diff line number	Diff line
		@@ -193,7 +193,7 @@ static void ccid3_hc_tx_no_feedback_timer(unsigned long data)
		switch (hctx->ccid3hctx_state) {
		case TFRC_SSTATE_NO_FBACK:
		/* RFC 3448, 4.4: Halve send rate directly */
		hctx->ccid3hctx_x = min_t(u32, hctx->ccid3hctx_x / 2,
		hctx->ccid3hctx_x = max_t(u32, hctx->ccid3hctx_x / 2,
		hctx->ccid3hctx_s / TFRC_T_MBI);

		ccid3_pr_debug("%s, sk=%p, state=%s, updated tx rate to %d "
		@@ -477,7 +477,7 @@ static void ccid3_hc_tx_packet_recv(struct sock sk, struct sk_buff skb)
		if (hctx->ccid3hctx_state == TFRC_SSTATE_NO_FBACK) {
		/* Use Larger Initial Windows [RFC 4342, sec. 5]
		* We deviate in that we use `s' instead of `MSS'. */
		u16 w_init = max( 4 * hctx->ccid3hctx_s,
		u16 w_init = min( 4 * hctx->ccid3hctx_s,
		max(2 * hctx->ccid3hctx_s, 4380));
		hctx->ccid3hctx_rtt = r_sample;
		hctx->ccid3hctx_x = usecs_div(w_init, r_sample);

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