Author: tuexen Date: Fri Sep 13 08:14:46 2019 New Revision: 352284 URL: https://svnweb.freebsd.org/changeset/base/352284
Log: MFC r352072: Only update SACK/DSACK lists when a non-empty segment was received. This fixes hitting a KASSERT with a valid packet exchange. PR: 240471 Reviewed by: rrs@, Richard Scheffenegger Sponsored by: Neflix, Inc. Differential Revision: https://reviews.freebsd.org/D21567 Modified: stable/12/sys/netinet/tcp_input.c stable/12/sys/netinet/tcp_stacks/rack.c Directory Properties: stable/12/ (props changed) Modified: stable/12/sys/netinet/tcp_input.c ============================================================================== --- stable/12/sys/netinet/tcp_input.c Fri Sep 13 07:24:29 2019 (r352283) +++ stable/12/sys/netinet/tcp_input.c Fri Sep 13 08:14:46 2019 (r352284) @@ -3065,9 +3065,8 @@ dodata: /* XXX */ thflags = tcp_reass(tp, th, &temp, &tlen, m); tp->t_flags |= TF_ACKNOW; } - if (tp->t_flags & TF_SACK_PERMIT) { - if (((tlen == 0) && (save_tlen > 0) && - (SEQ_LT(save_start, save_rnxt)))) { + if ((tp->t_flags & TF_SACK_PERMIT) && (save_tlen > 0)) { + if ((tlen == 0) && (SEQ_LT(save_start, save_rnxt))) { /* * DSACK actually handled in the fastpath * above. @@ -3075,20 +3074,20 @@ dodata: /* XXX */ 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. - */ if ((tp->rcv_numsacks >= 1) && (tp->sackblks[0].end == save_start)) { - /* partial overlap, recorded at todrop above */ - tcp_update_sack_list(tp, tp->sackblks[0].start, + /* + * Partial overlap, recorded at todrop + * above. + */ + tcp_update_sack_list(tp, + tp->sackblks[0].start, tp->sackblks[0].end); } else { tcp_update_dsack_list(tp, save_start, save_start + save_tlen); } - } else if ((tlen > 0) && (tlen >= save_tlen)) { + } else if (tlen >= save_tlen) { /* Update of sackblks. */ tcp_update_dsack_list(tp, save_start, save_start + save_tlen); Modified: stable/12/sys/netinet/tcp_stacks/rack.c ============================================================================== --- stable/12/sys/netinet/tcp_stacks/rack.c Fri Sep 13 07:24:29 2019 (r352283) +++ stable/12/sys/netinet/tcp_stacks/rack.c Fri Sep 13 08:14:46 2019 (r352284) @@ -4883,35 +4883,36 @@ dodata: /* XXX */ thflags = tcp_reass(tp, th, &temp, &tlen, m); tp->t_flags |= TF_ACKNOW; } - 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. - */ - if ((tp->rcv_numsacks >= 1) && - (tp->sackblks[0].end == save_start)) { - /* partial overlap, recorded at todrop above */ - tcp_update_sack_list(tp, tp->sackblks[0].start, - tp->sackblks[0].end); - } else { + if ((tp->t_flags & TF_SACK_PERMIT) && (save_tlen > 0)) { + if ((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)) { + if ((tp->rcv_numsacks >= 1) && + (tp->sackblks[0].end == save_start)) { + /* + * Partial overlap, recorded at todrop + * above. + */ + tcp_update_sack_list(tp, + tp->sackblks[0].start, + tp->sackblks[0].end); + } else { + tcp_update_dsack_list(tp, save_start, + save_start + save_tlen); + } + } else if (tlen >= save_tlen) { + /* Update of sackblks. */ tcp_update_dsack_list(tp, save_start, save_start + save_tlen); + } else if (tlen > 0) { + tcp_update_dsack_list(tp, save_start, + save_start + tlen); } - } else if ((tlen > 0) && (tlen >= save_tlen)) { - /* Update of sackblks. */ - tcp_update_dsack_list(tp, save_start, - save_start + save_tlen); - } else if (tlen > 0) { - tcp_update_dsack_list(tp, save_start, - save_start + tlen); } } else { m_freem(m); _______________________________________________ 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"
