diff options
| -rw-r--r-- | net/ipv4/tcp_input.c | 98 |
1 files changed, 47 insertions, 51 deletions
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c index 5187870d033..2711ef7df7b 100644 --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -1314,6 +1314,53 @@ tcp_sacktag_write_queue(struct sock *sk, struct sk_buff *ack_skb, u32 prior_snd_ /* F-RTO can only be used if TCP has never retransmitted anything other than * head (SACK enhanced variant from Appendix B of RFC4138 is more robust here) */ +static void tcp_check_reno_reordering(struct sock *sk, const int addend) +{ + struct tcp_sock *tp = tcp_sk(sk); + u32 holes; + + holes = max(tp->lost_out, 1U); + holes = min(holes, tp->packets_out); + + if ((tp->sacked_out + holes) > tp->packets_out) { + tp->sacked_out = tp->packets_out - holes; + tcp_update_reordering(sk, tp->packets_out + addend, 0); + } +} + +/* Emulate SACKs for SACKless connection: account for a new dupack. */ + +static void tcp_add_reno_sack(struct sock *sk) +{ + struct tcp_sock *tp = tcp_sk(sk); + tp->sacked_out++; + tcp_check_reno_reordering(sk, 0); + tcp_sync_left_out(tp); +} + +/* Account for ACK, ACKing some data in Reno Recovery phase. */ + +static void tcp_remove_reno_sacks(struct sock *sk, int acked) +{ + struct tcp_sock *tp = tcp_sk(sk); + + if (acked > 0) { + /* One ACK acked hole. The rest eat duplicate ACKs. */ + if (acked-1 >= tp->sacked_out) + tp->sacked_out = 0; + else + tp->sacked_out -= acked-1; + } + tcp_check_reno_reordering(sk, acked); + tcp_sync_left_out(tp); +} + +static inline void tcp_reset_reno_sack(struct tcp_sock *tp) +{ + tp->sacked_out = 0; + tp->left_out = tp->lost_out; +} + int tcp_use_frto(struct sock *sk) { const struct tcp_sock *tp = tcp_sk(sk); @@ -1730,57 +1777,6 @@ static int tcp_time_to_recover(struct sock *sk) return 0; } -/* If we receive more dupacks than we expected counting segments - * in assumption of absent reordering, interpret this as reordering. - * The only another reason could be bug in receiver TCP. - */ -static void tcp_check_reno_reordering(struct sock *sk, const int addend) -{ - struct tcp_sock *tp = tcp_sk(sk); - u32 holes; - - holes = max(tp->lost_out, 1U); - holes = min(holes, tp->packets_out); - - if ((tp->sacked_out + holes) > tp->packets_out) { - tp->sacked_out = tp->packets_out - holes; - tcp_update_reordering(sk, tp->packets_out + addend, 0); - } -} - -/* Emulate SACKs for SACKless connection: account for a new dupack. */ - -static void tcp_add_reno_sack(struct sock *sk) -{ - struct tcp_sock *tp = tcp_sk(sk); - tp->sacked_out++; - tcp_check_reno_reordering(sk, 0); - tcp_sync_left_out(tp); -} - -/* Account for ACK, ACKing some data in Reno Recovery phase. */ - -static void tcp_remove_reno_sacks(struct sock *sk, int acked) -{ - struct tcp_sock *tp = tcp_sk(sk); - - if (acked > 0) { - /* One ACK acked hole. The rest eat duplicate ACKs. */ - if (acked-1 >= tp->sacked_out) - tp->sacked_out = 0; - else - tp->sacked_out -= acked-1; - } - tcp_check_reno_reordering(sk, acked); - tcp_sync_left_out(tp); -} - -static inline void tcp_reset_reno_sack(struct tcp_sock *tp) -{ - tp->sacked_out = 0; - tp->left_out = tp->lost_out; -} - /* RFC: This is from the original, I doubt that this is necessary at all: * clear xmit_retrans hint if seq of this skb is beyond hint. How could we * retransmitted past LOST markings in the first place? I'm not fully sure |