The branch main has been updated by rstone: URL: https://cgit.FreeBSD.org/src/commit/?id=3284f4925f697ad7cc2aa4761ff5cf6ce98fd623
commit 3284f4925f697ad7cc2aa4761ff5cf6ce98fd623 Author: Ryan Stone <[email protected]> AuthorDate: 2022-01-01 16:54:19 +0000 Commit: Ryan Stone <[email protected]> CommitDate: 2022-01-13 16:17:58 +0000 LRO: Don't merge ACK and non-ACK packets together LRO was willing to merge ACK and non-ACK packets together. This can cause incorrect th_ack values to be reported up the stack. While non-ACKs are quite unlikely to appear in practice, LRO's behaviour is against the spec. Make LRO unwilling to merge packets with different TH_ACK flag values in order to fix the issue. Found by: Sysunit test Differential Revision: https://reviews.freebsd.org/D33775 Reviewed by: rrs --- sys/netinet/tcp_lro.c | 5 ++++- sys/netinet/tcp_lro.h | 5 +++-- 2 files changed, 7 insertions(+), 3 deletions(-) diff --git a/sys/netinet/tcp_lro.c b/sys/netinet/tcp_lro.c index f006cae57302..b973c788d23e 100644 --- a/sys/netinet/tcp_lro.c +++ b/sys/netinet/tcp_lro.c @@ -921,6 +921,7 @@ tcp_set_entry_to_mbuf(struct lro_ctrl *lc, struct lro_entry *le, le->next_seq = ntohl(th->th_seq) + tcp_data_len; le->ack_seq = th->th_ack; le->window = th->th_win; + le->flags = th->th_flags; le->needs_merge = 0; /* Setup new data pointers. */ @@ -1092,10 +1093,12 @@ again: } /* Try to append the new segment. */ if (__predict_false(ntohl(th->th_seq) != le->next_seq || + ((th->th_flags & TH_ACK) != + (le->flags & TH_ACK)) || (tcp_data_len == 0 && le->ack_seq == th->th_ack && le->window == th->th_win))) { - /* Out of order packet or duplicate ACK. */ + /* Out of order packet, non-ACK + ACK or dup ACK. */ tcp_push_and_replace(lc, le, m); goto again; } diff --git a/sys/netinet/tcp_lro.h b/sys/netinet/tcp_lro.h index 97819596231e..b8abc2fa1ab3 100644 --- a/sys/netinet/tcp_lro.h +++ b/sys/netinet/tcp_lro.h @@ -146,8 +146,9 @@ struct lro_entry { uint16_t compressed; uint16_t uncompressed; uint16_t window; - uint16_t timestamp : 1; - uint16_t needs_merge : 1; + uint8_t flags; + uint8_t timestamp : 1; + uint8_t needs_merge : 1; struct bintime alloc_time; /* time when entry was allocated */ };
