Author: tuexen Date: Thu Jun 6 07:49:03 2019 New Revision: 348728 URL: https://svnweb.freebsd.org/changeset/base/348728
Log: r347382 added receiver side DSACK support for the TCP base stack. The corresponding changes for the RACK stack where missed and are added by this commit. Reviewed by: Richard Scheffenegger, rrs@ MFC after: 3 days Differential Revision: https://reviews.freebsd.org/D20372 Modified: head/sys/netinet/tcp_stacks/rack.c Modified: head/sys/netinet/tcp_stacks/rack.c ============================================================================== --- head/sys/netinet/tcp_stacks/rack.c Thu Jun 6 06:38:29 2019 (r348727) +++ head/sys/netinet/tcp_stacks/rack.c Thu Jun 6 07:49:03 2019 (r348728) @@ -1721,6 +1721,17 @@ rack_drop_checks(struct tcpopt *to, struct mbuf *m, st TCPSTAT_INC(tcps_rcvpartduppack); TCPSTAT_ADD(tcps_rcvpartdupbyte, todrop); } + /* + * DSACK - add SACK block for dropped range + */ + if (tp->t_flags & TF_SACK_PERMIT) { + tcp_update_sack_list(tp, th->th_seq, th->th_seq + tlen); + /* + * ACK now, as the next in-sequence segment + * will clear the DSACK block again + */ + tp->t_flags |= TF_ACKNOW; + } *drop_hdrlen += todrop; /* drop from the top afterwards */ th->th_seq += todrop; tlen -= todrop; @@ -4753,6 +4764,8 @@ dodata: /* XXX */ if ((tlen || (thflags & TH_FIN) || tfo_syn) && TCPS_HAVERCVDFIN(tp->t_state) == 0) { tcp_seq save_start = th->th_seq; + tcp_seq save_rnxt = tp->rcv_nxt; + int save_tlen = tlen; m_adj(m, drop_hdrlen); /* delayed header drop */ /* @@ -4795,11 +4808,29 @@ dodata: /* XXX */ * m_adj() doesn't actually frees any mbufs when * trimming from the head. */ - thflags = tcp_reass(tp, th, &save_start, &tlen, m); + tcp_seq temp = save_start; + thflags = tcp_reass(tp, th, &temp, &tlen, m); tp->t_flags |= TF_ACKNOW; } - if (tlen > 0) - tcp_update_sack_list(tp, save_start, save_start + tlen); + if (((tlen == 0) && (save_tlen > 0) && + (SEQ_LT(save_start, save_rnxt)))) { + /* + * DSACK actually handled in the fastpath + * above. + */ + tcp_update_sack_list(tp, save_start, save_start + save_tlen); + } else if ((tlen > 0) && SEQ_GT(tp->rcv_nxt, save_rnxt)) { + /* + * Cleaning sackblks by using zero length + * update. + */ + tcp_update_sack_list(tp, save_start, save_start); + } else if ((tlen > 0) && (tlen >= save_tlen)) { + /* Update of sackblks. */ + tcp_update_sack_list(tp, save_start, save_start + save_tlen); + } else if (tlen > 0) { + tcp_update_sack_list(tp, save_start, save_start+tlen); + } } else { m_freem(m); thflags &= ~TH_FIN; _______________________________________________ [email protected] mailing list https://lists.freebsd.org/mailman/listinfo/svn-src-all To unsubscribe, send any mail to "[email protected]"
