diff options
Diffstat (limited to 'sys/netinet/tcp_sack.c')
| -rw-r--r-- | sys/netinet/tcp_sack.c | 18 |
1 files changed, 14 insertions, 4 deletions
diff --git a/sys/netinet/tcp_sack.c b/sys/netinet/tcp_sack.c index f9c71c8..82e2251 100644 --- a/sys/netinet/tcp_sack.c +++ b/sys/netinet/tcp_sack.c @@ -345,17 +345,22 @@ tcp_sackhole_remove(struct tcpcb *tp, struct sackhole *hole) * Process cumulative ACK and the TCP SACK option to update the scoreboard. * tp->snd_holes is an ordered list of holes (oldest to newest, in terms of * the sequence space). + * Returns 1 if incoming ACK has previously unknown SACK information, + * 0 otherwise. Note: We treat (snd_una, th_ack) as a sack block so any changes + * to that (i.e. left edge moving) would also be considered a change in SACK + * information which is slightly different than rfc6675. */ -void +int tcp_sack_doack(struct tcpcb *tp, struct tcpopt *to, tcp_seq th_ack) { struct sackhole *cur, *temp; struct sackblk sack, sack_blocks[TCP_MAX_SACK + 1], *sblkp; - int i, j, num_sack_blks; + int i, j, num_sack_blks, sack_changed; INP_WLOCK_ASSERT(tp->t_inpcb); num_sack_blks = 0; + sack_changed = 0; /* * If SND.UNA will be advanced by SEG.ACK, and if SACK holes exist, * treat [SND.UNA, SEG.ACK) as if it is a SACK block. @@ -392,7 +397,7 @@ tcp_sack_doack(struct tcpcb *tp, struct tcpopt *to, tcp_seq th_ack) * received. */ if (num_sack_blks == 0) - return; + return (sack_changed); /* * Sort the SACK blocks so we can update the scoreboard with just one @@ -443,6 +448,7 @@ tcp_sack_doack(struct tcpcb *tp, struct tcpopt *to, tcp_seq th_ack) tp->snd_fack = sblkp->end; /* Go to the previous sack block. */ sblkp--; + sack_changed = 1; } else { /* * We failed to add a new hole based on the current @@ -459,9 +465,11 @@ tcp_sack_doack(struct tcpcb *tp, struct tcpopt *to, tcp_seq th_ack) SEQ_LT(tp->snd_fack, sblkp->end)) tp->snd_fack = sblkp->end; } - } else if (SEQ_LT(tp->snd_fack, sblkp->end)) + } else if (SEQ_LT(tp->snd_fack, sblkp->end)) { /* fack is advanced. */ tp->snd_fack = sblkp->end; + sack_changed = 1; + } /* We must have at least one SACK hole in scoreboard. */ KASSERT(!TAILQ_EMPTY(&tp->snd_holes), ("SACK scoreboard must not be empty")); @@ -490,6 +498,7 @@ tcp_sack_doack(struct tcpcb *tp, struct tcpopt *to, tcp_seq th_ack) tp->sackhint.sack_bytes_rexmit -= (cur->rxmit - cur->start); KASSERT(tp->sackhint.sack_bytes_rexmit >= 0, ("sackhint bytes rtx >= 0")); + sack_changed = 1; if (SEQ_LEQ(sblkp->start, cur->start)) { /* Data acks at least the beginning of hole. */ if (SEQ_GEQ(sblkp->end, cur->end)) { @@ -545,6 +554,7 @@ tcp_sack_doack(struct tcpcb *tp, struct tcpopt *to, tcp_seq th_ack) else sblkp--; } + return (sack_changed); } /* |
