Author: shurd Date: Fri Jan 25 18:30:12 2019 New Revision: 343441 URL: https://svnweb.freebsd.org/changeset/base/343441
Log: MFC r343047: Fix window update issue when scaling disabled When the TCP window scale option is not used, and the window opens up enough in one soreceive, a window update will not be sent. For example, if recwin == 65535, so->so_rcv.sb_hiwat >= 262144, and so->so_rcv.sb_hiwat <= 524272, the window update will never be sent. This is because recwin and adv are clamped to TCP_MAXWIN << tp->rcv_scale, and so will never be >= so->so_rcv.sb_hiwat / 4 or <= so->so_rcv.sb_hiwat / 8. This patch ensures a window update is sent if the window opens by TCP_MAXWIN << tp->rcv_scale, which should only happen when the window size goes from zero to the max expressible. This issue looks like it was introduced in r306769 when recwin was clamped to TCP_MAXWIN << tp->rcv_scale. Sponsored by: Limelight Networks Differential Revision: https://reviews.freebsd.org/D18821 Modified: stable/12/sys/netinet/tcp_output.c Directory Properties: stable/12/ (props changed) Modified: stable/12/sys/netinet/tcp_output.c ============================================================================== --- stable/12/sys/netinet/tcp_output.c Fri Jan 25 17:09:26 2019 (r343440) +++ stable/12/sys/netinet/tcp_output.c Fri Jan 25 18:30:12 2019 (r343441) @@ -656,7 +656,8 @@ after_sack_rexmit: if (adv >= (int32_t)(2 * tp->t_maxseg) && (adv >= (int32_t)(so->so_rcv.sb_hiwat / 4) || recwin <= (so->so_rcv.sb_hiwat / 8) || - so->so_rcv.sb_hiwat <= 8 * tp->t_maxseg)) + so->so_rcv.sb_hiwat <= 8 * tp->t_maxseg || + adv >= TCP_MAXWIN << tp->rcv_scale)) goto send; if (2 * adv >= (int32_t)so->so_rcv.sb_hiwat) goto send; _______________________________________________ svn-src-all@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/svn-src-all To unsubscribe, send any mail to "svn-src-all-unsubscr...@freebsd.org"
