diff options
author | Ingo Molnar <mingo@elte.hu> | 2008-10-12 12:49:27 +0200 |
---|---|---|
committer | Ingo Molnar <mingo@elte.hu> | 2008-10-12 12:49:27 +0200 |
commit | 1389ac4b976abdc0555280dfc1aa2c3abcc19641 (patch) | |
tree | 1ec51aa0b1e33201f6f4f3bebc657f9ec65f8539 /net/ipv4/tcp_output.c | |
parent | 69e13ad56f9e2cd81c4f8bfd6267211c10c14c08 (diff) | |
parent | fd048088306656824958e7783ffcee27e241b361 (diff) |
Merge branch 'linus' into x86/signal
Conflicts:
arch/x86/kernel/signal_64.c
Diffstat (limited to 'net/ipv4/tcp_output.c')
-rw-r--r-- | net/ipv4/tcp_output.c | 222 |
1 files changed, 113 insertions, 109 deletions
diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c index 8165f5aa8c7..990a5849323 100644 --- a/net/ipv4/tcp_output.c +++ b/net/ipv4/tcp_output.c @@ -345,6 +345,11 @@ static void tcp_init_nondata_skb(struct sk_buff *skb, u32 seq, u8 flags) TCP_SKB_CB(skb)->end_seq = seq; } +static inline int tcp_urg_mode(const struct tcp_sock *tp) +{ + return tp->snd_una != tp->snd_up; +} + #define OPTION_SACK_ADVERTISE (1 << 0) #define OPTION_TS (1 << 1) #define OPTION_MD5 (1 << 2) @@ -646,7 +651,8 @@ static int tcp_transmit_skb(struct sock *sk, struct sk_buff *skb, int clone_it, th->check = 0; th->urg_ptr = 0; - if (unlikely(tp->urg_mode && + /* The urg_mode check is necessary during a below snd_una win probe */ + if (unlikely(tcp_urg_mode(tp) && between(tp->snd_up, tcb->seq + 1, tcb->seq + 0xFFFF))) { th->urg_ptr = htons(tp->snd_up - tcb->seq); th->urg = 1; @@ -1012,7 +1018,7 @@ unsigned int tcp_sync_mss(struct sock *sk, u32 pmtu) /* Compute the current effective MSS, taking SACKs and IP options, * and even PMTU discovery events into account. * - * LARGESEND note: !urg_mode is overkill, only frames up to snd_up + * LARGESEND note: !tcp_urg_mode is overkill, only frames up to snd_up * cannot be large. However, taking into account rare use of URG, this * is not a big flaw. */ @@ -1029,7 +1035,7 @@ unsigned int tcp_current_mss(struct sock *sk, int large_allowed) mss_now = tp->mss_cache; - if (large_allowed && sk_can_gso(sk) && !tp->urg_mode) + if (large_allowed && sk_can_gso(sk) && !tcp_urg_mode(tp)) doing_tso = 1; if (dst) { @@ -1193,7 +1199,7 @@ static inline int tcp_nagle_test(struct tcp_sock *tp, struct sk_buff *skb, /* Don't use the nagle rule for urgent data (or for the final FIN). * Nagle can be ignored during F-RTO too (see RFC4138). */ - if (tp->urg_mode || (tp->frto_counter == 2) || + if (tcp_urg_mode(tp) || (tp->frto_counter == 2) || (TCP_SKB_CB(skb)->flags & TCPCB_FLAG_FIN)) return 1; @@ -1824,6 +1830,8 @@ static void tcp_retrans_try_collapse(struct sock *sk, struct sk_buff *skb, /* changed transmit queue under us so clear hints */ tcp_clear_retrans_hints_partial(tp); + if (next_skb == tp->retransmit_skb_hint) + tp->retransmit_skb_hint = skb; sk_wmem_free_skb(sk, next_skb); } @@ -1838,7 +1846,7 @@ void tcp_simple_retransmit(struct sock *sk) struct tcp_sock *tp = tcp_sk(sk); struct sk_buff *skb; unsigned int mss = tcp_current_mss(sk, 0); - int lost = 0; + u32 prior_lost = tp->lost_out; tcp_for_write_queue(skb, sk) { if (skb == tcp_send_head(sk)) @@ -1849,17 +1857,13 @@ void tcp_simple_retransmit(struct sock *sk) TCP_SKB_CB(skb)->sacked &= ~TCPCB_SACKED_RETRANS; tp->retrans_out -= tcp_skb_pcount(skb); } - if (!(TCP_SKB_CB(skb)->sacked & TCPCB_LOST)) { - TCP_SKB_CB(skb)->sacked |= TCPCB_LOST; - tp->lost_out += tcp_skb_pcount(skb); - lost = 1; - } + tcp_skb_mark_lost_uncond_verify(tp, skb); } } - tcp_clear_all_retrans_hints(tp); + tcp_clear_retrans_hints_partial(tp); - if (!lost) + if (prior_lost == tp->lost_out) return; if (tcp_is_reno(tp)) @@ -1934,8 +1938,8 @@ int tcp_retransmit_skb(struct sock *sk, struct sk_buff *skb) /* Collapse two adjacent packets if worthwhile and we can. */ if (!(TCP_SKB_CB(skb)->flags & TCPCB_FLAG_SYN) && (skb->len < (cur_mss >> 1)) && - (tcp_write_queue_next(sk, skb) != tcp_send_head(sk)) && (!tcp_skb_is_last(sk, skb)) && + (tcp_write_queue_next(sk, skb) != tcp_send_head(sk)) && (skb_shinfo(skb)->nr_frags == 0 && skb_shinfo(tcp_write_queue_next(sk, skb))->nr_frags == 0) && (tcp_skb_pcount(skb) == 1 && @@ -1996,86 +2000,18 @@ int tcp_retransmit_skb(struct sock *sk, struct sk_buff *skb) return err; } -/* This gets called after a retransmit timeout, and the initially - * retransmitted data is acknowledged. It tries to continue - * resending the rest of the retransmit queue, until either - * we've sent it all or the congestion window limit is reached. - * If doing SACK, the first ACK which comes back for a timeout - * based retransmit packet might feed us FACK information again. - * If so, we use it to avoid unnecessarily retransmissions. - */ -void tcp_xmit_retransmit_queue(struct sock *sk) +static int tcp_can_forward_retransmit(struct sock *sk) { const struct inet_connection_sock *icsk = inet_csk(sk); struct tcp_sock *tp = tcp_sk(sk); - struct sk_buff *skb; - int packet_cnt; - - if (tp->retransmit_skb_hint) { - skb = tp->retransmit_skb_hint; - packet_cnt = tp->retransmit_cnt_hint; - } else { - skb = tcp_write_queue_head(sk); - packet_cnt = 0; - } - - /* First pass: retransmit lost packets. */ - if (tp->lost_out) { - tcp_for_write_queue_from(skb, sk) { - __u8 sacked = TCP_SKB_CB(skb)->sacked; - - if (skb == tcp_send_head(sk)) - break; - /* we could do better than to assign each time */ - tp->retransmit_skb_hint = skb; - tp->retransmit_cnt_hint = packet_cnt; - - /* Assume this retransmit will generate - * only one packet for congestion window - * calculation purposes. This works because - * tcp_retransmit_skb() will chop up the - * packet to be MSS sized and all the - * packet counting works out. - */ - if (tcp_packets_in_flight(tp) >= tp->snd_cwnd) - return; - - if (sacked & TCPCB_LOST) { - if (!(sacked & (TCPCB_SACKED_ACKED|TCPCB_SACKED_RETRANS))) { - int mib_idx; - - if (tcp_retransmit_skb(sk, skb)) { - tp->retransmit_skb_hint = NULL; - return; - } - if (icsk->icsk_ca_state != TCP_CA_Loss) - mib_idx = LINUX_MIB_TCPFASTRETRANS; - else - mib_idx = LINUX_MIB_TCPSLOWSTARTRETRANS; - NET_INC_STATS_BH(sock_net(sk), mib_idx); - - if (skb == tcp_write_queue_head(sk)) - inet_csk_reset_xmit_timer(sk, ICSK_TIME_RETRANS, - inet_csk(sk)->icsk_rto, - TCP_RTO_MAX); - } - - packet_cnt += tcp_skb_pcount(skb); - if (packet_cnt >= tp->lost_out) - break; - } - } - } - - /* OK, demanded retransmission is finished. */ /* Forward retransmissions are possible only during Recovery. */ if (icsk->icsk_ca_state != TCP_CA_Recovery) - return; + return 0; /* No forward retransmissions in Reno are possible. */ if (tcp_is_reno(tp)) - return; + return 0; /* Yeah, we have to make difficult choice between forward transmission * and retransmission... Both ways have their merits... @@ -2086,43 +2022,104 @@ void tcp_xmit_retransmit_queue(struct sock *sk) */ if (tcp_may_send_now(sk)) - return; + return 0; - /* If nothing is SACKed, highest_sack in the loop won't be valid */ - if (!tp->sacked_out) - return; + return 1; +} - if (tp->forward_skb_hint) - skb = tp->forward_skb_hint; - else +/* This gets called after a retransmit timeout, and the initially + * retransmitted data is acknowledged. It tries to continue + * resending the rest of the retransmit queue, until either + * we've sent it all or the congestion window limit is reached. + * If doing SACK, the first ACK which comes back for a timeout + * based retransmit packet might feed us FACK information again. + * If so, we use it to avoid unnecessarily retransmissions. + */ +void tcp_xmit_retransmit_queue(struct sock *sk) +{ + const struct inet_connection_sock *icsk = inet_csk(sk); + struct tcp_sock *tp = tcp_sk(sk); + struct sk_buff *skb; + struct sk_buff *hole = NULL; + u32 last_lost; + int mib_idx; + int fwd_rexmitting = 0; + + if (!tp->lost_out) + tp->retransmit_high = tp->snd_una; + + if (tp->retransmit_skb_hint) { + skb = tp->retransmit_skb_hint; + last_lost = TCP_SKB_CB(skb)->end_seq; + if (after(last_lost, tp->retransmit_high)) + last_lost = tp->retransmit_high; + } else { skb = tcp_write_queue_head(sk); + last_lost = tp->snd_una; + } + /* First pass: retransmit lost packets. */ tcp_for_write_queue_from(skb, sk) { - if (skb == tcp_send_head(sk)) - break; - tp->forward_skb_hint = skb; + __u8 sacked = TCP_SKB_CB(skb)->sacked; - if (!before(TCP_SKB_CB(skb)->seq, tcp_highest_sack_seq(tp))) + if (skb == tcp_send_head(sk)) break; + /* we could do better than to assign each time */ + if (hole == NULL) + tp->retransmit_skb_hint = skb; + /* Assume this retransmit will generate + * only one packet for congestion window + * calculation purposes. This works because + * tcp_retransmit_skb() will chop up the + * packet to be MSS sized and all the + * packet counting works out. + */ if (tcp_packets_in_flight(tp) >= tp->snd_cwnd) - break; + return; + + if (fwd_rexmitting) { +begin_fwd: + if (!before(TCP_SKB_CB(skb)->seq, tcp_highest_sack_seq(tp))) + break; + mib_idx = LINUX_MIB_TCPFORWARDRETRANS; + + } else if (!before(TCP_SKB_CB(skb)->seq, tp->retransmit_high)) { + tp->retransmit_high = last_lost; + if (!tcp_can_forward_retransmit(sk)) + break; + /* Backtrack if necessary to non-L'ed skb */ + if (hole != NULL) { + skb = hole; + hole = NULL; + } + fwd_rexmitting = 1; + goto begin_fwd; - if (TCP_SKB_CB(skb)->sacked & TCPCB_TAGBITS) + } else if (!(sacked & TCPCB_LOST)) { + if (hole == NULL && !(sacked & TCPCB_SACKED_RETRANS)) + hole = skb; continue; - /* Ok, retransmit it. */ - if (tcp_retransmit_skb(sk, skb)) { - tp->forward_skb_hint = NULL; - break; + } else { + last_lost = TCP_SKB_CB(skb)->end_seq; + if (icsk->icsk_ca_state != TCP_CA_Loss) + mib_idx = LINUX_MIB_TCPFASTRETRANS; + else + mib_idx = LINUX_MIB_TCPSLOWSTARTRETRANS; } + if (sacked & (TCPCB_SACKED_ACKED|TCPCB_SACKED_RETRANS)) + continue; + + if (tcp_retransmit_skb(sk, skb)) + return; + NET_INC_STATS_BH(sock_net(sk), mib_idx); + if (skb == tcp_write_queue_head(sk)) inet_csk_reset_xmit_timer(sk, ICSK_TIME_RETRANS, inet_csk(sk)->icsk_rto, TCP_RTO_MAX); - - NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPFORWARDRETRANS); } } @@ -2241,6 +2238,7 @@ struct sk_buff *tcp_make_synack(struct sock *sk, struct dst_entry *dst, struct sk_buff *skb; struct tcp_md5sig_key *md5; __u8 *md5_hash_location; + int mss; skb = sock_wmalloc(sk, MAX_TCP_HEADER + 15, 1, GFP_ATOMIC); if (skb == NULL) @@ -2251,13 +2249,17 @@ struct sk_buff *tcp_make_synack(struct sock *sk, struct dst_entry *dst, skb->dst = dst_clone(dst); + mss = dst_metric(dst, RTAX_ADVMSS); + if (tp->rx_opt.user_mss && tp->rx_opt.user_mss < mss) + mss = tp->rx_opt.user_mss; + if (req->rcv_wnd == 0) { /* ignored for retransmitted syns */ __u8 rcv_wscale; /* Set this up on the first call only */ req->window_clamp = tp->window_clamp ? : dst_metric(dst, RTAX_WINDOW); /* tcp_full_space because it is guaranteed to be the first packet */ tcp_select_initial_window(tcp_full_space(sk), - dst_metric(dst, RTAX_ADVMSS) - (ireq->tstamp_ok ? TCPOLEN_TSTAMP_ALIGNED : 0), + mss - (ireq->tstamp_ok ? TCPOLEN_TSTAMP_ALIGNED : 0), &req->rcv_wnd, &req->window_clamp, ireq->wscale_ok, @@ -2267,8 +2269,7 @@ struct sk_buff *tcp_make_synack(struct sock *sk, struct dst_entry *dst, memset(&opts, 0, sizeof(opts)); TCP_SKB_CB(skb)->when = tcp_time_stamp; - tcp_header_size = tcp_synack_options(sk, req, - dst_metric(dst, RTAX_ADVMSS), + tcp_header_size = tcp_synack_options(sk, req, mss, skb, &opts, &md5) + sizeof(struct tcphdr); @@ -2280,7 +2281,7 @@ struct sk_buff *tcp_make_synack(struct sock *sk, struct dst_entry *dst, th->syn = 1; th->ack = 1; TCP_ECN_make_synack(req, th); - th->source = inet_sk(sk)->sport; + th->source = ireq->loc_port; th->dest = ireq->rmt_port; /* Setting of flags are superfluous here for callers (and ECE is * not even correctly set) @@ -2342,6 +2343,9 @@ static void tcp_connect_init(struct sock *sk) if (!tp->window_clamp) tp->window_clamp = dst_metric(dst, RTAX_WINDOW); tp->advmss = dst_metric(dst, RTAX_ADVMSS); + if (tp->rx_opt.user_mss && tp->rx_opt.user_mss < tp->advmss) + tp->advmss = tp->rx_opt.user_mss; + tcp_initialize_rcv_mss(sk); tcp_select_initial_window(tcp_full_space(sk), @@ -2360,6 +2364,7 @@ static void tcp_connect_init(struct sock *sk) tcp_init_wl(tp, tp->write_seq, 0); tp->snd_una = tp->write_seq; tp->snd_sml = tp->write_seq; + tp->snd_up = tp->write_seq; tp->rcv_nxt = 0; tp->rcv_wup = 0; tp->copied_seq = 0; @@ -2569,8 +2574,7 @@ int tcp_write_wakeup(struct sock *sk) tcp_event_new_data_sent(sk, skb); return err; } else { - if (tp->urg_mode && - between(tp->snd_up, tp->snd_una + 1, tp->snd_una + 0xFFFF)) + if (between(tp->snd_up, tp->snd_una + 1, tp->snd_una + 0xFFFF)) tcp_xmit_probe_skb(sk, 1); return tcp_xmit_probe_skb(sk, 0); } |