diff options
| -rw-r--r-- | net/ipv4/tcp_output.c | 233 |
1 files changed, 124 insertions, 109 deletions
diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c index 029c70d..b7325e0 100644 --- a/net/ipv4/tcp_output.c +++ b/net/ipv4/tcp_output.c @@ -262,122 +262,139 @@ static __inline__ u16 tcp_select_window(struct sock *sk) * We are working here with either a clone of the original * SKB, or a fresh unique copy made by the retransmit engine. */ -static int tcp_transmit_skb(struct sock *sk, struct sk_buff *skb) +static int tcp_transmit_skb(struct sock *sk, struct sk_buff *skb, int clone_it, gfp_t gfp_mask) { - if (skb != NULL) { - const struct inet_connection_sock *icsk = inet_csk(sk); - struct inet_sock *inet = inet_sk(sk); - struct tcp_sock *tp = tcp_sk(sk); - struct tcp_skb_cb *tcb = TCP_SKB_CB(skb); - int tcp_header_size = tp->tcp_header_len; - struct tcphdr *th; - int sysctl_flags; - int err; + const struct inet_connection_sock *icsk = inet_csk(sk); + struct inet_sock *inet; + struct tcp_sock *tp; + struct tcp_skb_cb *tcb; + int tcp_header_size; + struct tcphdr *th; + int sysctl_flags; + int err; + + BUG_ON(!skb || !tcp_skb_pcount(skb)); + + /* If congestion control is doing timestamping, we must + * take such a timestamp before we potentially clone/copy. + */ + if (icsk->icsk_ca_ops->rtt_sample) + __net_timestamp(skb); + + if (likely(clone_it)) { + if (unlikely(skb_cloned(skb))) + skb = pskb_copy(skb, gfp_mask); + else + skb = skb_clone(skb, gfp_mask); + if (unlikely(!skb)) + return -ENOBUFS; + } - BUG_ON(!tcp_skb_pcount(skb)); + inet = inet_sk(sk); + tp = tcp_sk(sk); + tcb = TCP_SKB_CB(skb); + tcp_header_size = tp->tcp_header_len; #define SYSCTL_FLAG_TSTAMPS 0x1 #define SYSCTL_FLAG_WSCALE 0x2 #define SYSCTL_FLAG_SACK 0x4 - /* If congestion control is doing timestamping */ - if (icsk->icsk_ca_ops->rtt_sample) - __net_timestamp(skb); - - sysctl_flags = 0; - if (tcb->flags & TCPCB_FLAG_SYN) { - tcp_header_size = sizeof(struct tcphdr) + TCPOLEN_MSS; - if(sysctl_tcp_timestamps) { - tcp_header_size += TCPOLEN_TSTAMP_ALIGNED; - sysctl_flags |= SYSCTL_FLAG_TSTAMPS; - } - if(sysctl_tcp_window_scaling) { - tcp_header_size += TCPOLEN_WSCALE_ALIGNED; - sysctl_flags |= SYSCTL_FLAG_WSCALE; - } - if(sysctl_tcp_sack) { - sysctl_flags |= SYSCTL_FLAG_SACK; - if(!(sysctl_flags & SYSCTL_FLAG_TSTAMPS)) - tcp_header_size += TCPOLEN_SACKPERM_ALIGNED; - } - } else if (tp->rx_opt.eff_sacks) { - /* A SACK is 2 pad bytes, a 2 byte header, plus - * 2 32-bit sequence numbers for each SACK block. - */ - tcp_header_size += (TCPOLEN_SACK_BASE_ALIGNED + - (tp->rx_opt.eff_sacks * TCPOLEN_SACK_PERBLOCK)); + sysctl_flags = 0; + if (unlikely(tcb->flags & TCPCB_FLAG_SYN)) { + tcp_header_size = sizeof(struct tcphdr) + TCPOLEN_MSS; + if(sysctl_tcp_timestamps) { + tcp_header_size += TCPOLEN_TSTAMP_ALIGNED; + sysctl_flags |= SYSCTL_FLAG_TSTAMPS; } - - if (tcp_packets_in_flight(tp) == 0) - tcp_ca_event(sk, CA_EVENT_TX_START); - - th = (struct tcphdr *) skb_push(skb, tcp_header_size); - skb->h.th = th; - skb_set_owner_w(skb, sk); - - /* Build TCP header and checksum it. */ - th->source = inet->sport; - th->dest = inet->dport; - th->seq = htonl(tcb->seq); - th->ack_seq = htonl(tp->rcv_nxt); - *(((__u16 *)th) + 6) = htons(((tcp_header_size >> 2) << 12) | tcb->flags); - if (tcb->flags & TCPCB_FLAG_SYN) { - /* RFC1323: The window in SYN & SYN/ACK segments - * is never scaled. - */ - th->window = htons(tp->rcv_wnd); - } else { - th->window = htons(tcp_select_window(sk)); + if (sysctl_tcp_window_scaling) { + tcp_header_size += TCPOLEN_WSCALE_ALIGNED; + sysctl_flags |= SYSCTL_FLAG_WSCALE; } - th->check = 0; - th->urg_ptr = 0; - - if (tp->urg_mode && - between(tp->snd_up, tcb->seq+1, tcb->seq+0xFFFF)) { - th->urg_ptr = htons(tp->snd_up-tcb->seq); - th->urg = 1; + if (sysctl_tcp_sack) { + sysctl_flags |= SYSCTL_FLAG_SACK; + if (!(sysctl_flags & SYSCTL_FLAG_TSTAMPS)) + tcp_header_size += TCPOLEN_SACKPERM_ALIGNED; } + } else if (unlikely(tp->rx_opt.eff_sacks)) { + /* A SACK is 2 pad bytes, a 2 byte header, plus + * 2 32-bit sequence numbers for each SACK block. + */ + tcp_header_size += (TCPOLEN_SACK_BASE_ALIGNED + + (tp->rx_opt.eff_sacks * + TCPOLEN_SACK_PERBLOCK)); + } + + if (tcp_packets_in_flight(tp) == 0) + tcp_ca_event(sk, CA_EVENT_TX_START); + + th = (struct tcphdr *) skb_push(skb, tcp_header_size); + skb->h.th = th; + skb_set_owner_w(skb, sk); + + /* Build TCP header and checksum it. */ + th->source = inet->sport; + th->dest = inet->dport; + th->seq = htonl(tcb->seq); + th->ack_seq = htonl(tp->rcv_nxt); + *(((__u16 *)th) + 6) = htons(((tcp_header_size >> 2) << 12) | + tcb->flags); + + if (unlikely(tcb->flags & TCPCB_FLAG_SYN)) { + /* RFC1323: The window in SYN & SYN/ACK segments + * is never scaled. + */ + th->window = htons(tp->rcv_wnd); + } else { + th->window = htons(tcp_select_window(sk)); + } + th->check = 0; + th->urg_ptr = 0; - if (tcb->flags & TCPCB_FLAG_SYN) { - tcp_syn_build_options((__u32 *)(th + 1), - tcp_advertise_mss(sk), - (sysctl_flags & SYSCTL_FLAG_TSTAMPS), - (sysctl_flags & SYSCTL_FLAG_SACK), - (sysctl_flags & SYSCTL_FLAG_WSCALE), - tp->rx_opt.rcv_wscale, - tcb->when, - tp->rx_opt.ts_recent); - } else { - tcp_build_and_update_options((__u32 *)(th + 1), - tp, tcb->when); + if (unlikely(tp->urg_mode && + between(tp->snd_up, tcb->seq+1, tcb->seq+0xFFFF))) { + th->urg_ptr = htons(tp->snd_up-tcb->seq); + th->urg = 1; + } - TCP_ECN_send(sk, tp, skb, tcp_header_size); - } - tp->af_specific->send_check(sk, th, skb->len, skb); + if (unlikely(tcb->flags & TCPCB_FLAG_SYN)) { + tcp_syn_build_options((__u32 *)(th + 1), + tcp_advertise_mss(sk), + (sysctl_flags & SYSCTL_FLAG_TSTAMPS), + (sysctl_flags & SYSCTL_FLAG_SACK), + (sysctl_flags & SYSCTL_FLAG_WSCALE), + tp->rx_opt.rcv_wscale, + tcb->when, + tp->rx_opt.ts_recent); + } else { + tcp_build_and_update_options((__u32 *)(th + 1), + tp, tcb->when); + TCP_ECN_send(sk, tp, skb, tcp_header_size); + } - if (tcb->flags & TCPCB_FLAG_ACK) - tcp_event_ack_sent(sk, tcp_skb_pcount(skb)); + tp->af_specific->send_check(sk, th, skb->len, skb); - if (skb->len != tcp_header_size) - tcp_event_data_sent(tp, skb, sk); + if (likely(tcb->flags & TCPCB_FLAG_ACK)) + tcp_event_ack_sent(sk, tcp_skb_pcount(skb)); - TCP_INC_STATS(TCP_MIB_OUTSEGS); + if (skb->len != tcp_header_size) + tcp_event_data_sent(tp, skb, sk); - err = tp->af_specific->queue_xmit(skb, 0); - if (err <= 0) - return err; + TCP_INC_STATS(TCP_MIB_OUTSEGS); - tcp_enter_cwr(sk); + err = tp->af_specific->queue_xmit(skb, 0); + if (unlikely(err <= 0)) + return err; + + tcp_enter_cwr(sk); + + /* NET_XMIT_CN is special. It does not guarantee, + * that this packet is lost. It tells that device + * is about to start to drop packets or already + * drops some packets of the same priority and + * invokes us to send less aggressively. + */ + return err == NET_XMIT_CN ? 0 : err; - /* NET_XMIT_CN is special. It does not guarantee, - * that this packet is lost. It tells that device - * is about to start to drop packets or already - * drops some packets of the same priority and - * invokes us to send less aggressively. - */ - return err == NET_XMIT_CN ? 0 : err; - } - return -ENOBUFS; #undef SYSCTL_FLAG_TSTAMPS #undef SYSCTL_FLAG_WSCALE #undef SYSCTL_FLAG_SACK @@ -1036,7 +1053,7 @@ static int tcp_write_xmit(struct sock *sk, unsigned int mss_now, int nonagle) TCP_SKB_CB(skb)->when = tcp_time_stamp; - if (unlikely(tcp_transmit_skb(sk, skb_clone(skb, GFP_ATOMIC)))) + if (unlikely(tcp_transmit_skb(sk, skb, 1, GFP_ATOMIC))) break; /* Advance the send_head. This one is sent out. @@ -1109,7 +1126,7 @@ void tcp_push_one(struct sock *sk, unsigned int mss_now) /* Send it out now. */ TCP_SKB_CB(skb)->when = tcp_time_stamp; - if (likely(!tcp_transmit_skb(sk, skb_clone(skb, sk->sk_allocation)))) { + if (likely(!tcp_transmit_skb(sk, skb, 1, sk->sk_allocation))) { update_send_head(sk, tp, skb); tcp_cwnd_validate(sk, tp); return; @@ -1429,9 +1446,7 @@ int tcp_retransmit_skb(struct sock *sk, struct sk_buff *skb) */ TCP_SKB_CB(skb)->when = tcp_time_stamp; - err = tcp_transmit_skb(sk, (skb_cloned(skb) ? - pskb_copy(skb, GFP_ATOMIC): - skb_clone(skb, GFP_ATOMIC))); + err = tcp_transmit_skb(sk, skb, 1, GFP_ATOMIC); if (err == 0) { /* Update global TCP statistics. */ @@ -1665,7 +1680,7 @@ void tcp_send_active_reset(struct sock *sk, gfp_t priority) TCP_SKB_CB(skb)->seq = tcp_acceptable_seq(sk, tp); TCP_SKB_CB(skb)->end_seq = TCP_SKB_CB(skb)->seq; TCP_SKB_CB(skb)->when = tcp_time_stamp; - if (tcp_transmit_skb(sk, skb)) + if (tcp_transmit_skb(sk, skb, 0, priority)) NET_INC_STATS(LINUX_MIB_TCPABORTFAILED); } @@ -1700,7 +1715,7 @@ int tcp_send_synack(struct sock *sk) TCP_ECN_send_synack(tcp_sk(sk), skb); } TCP_SKB_CB(skb)->when = tcp_time_stamp; - return tcp_transmit_skb(sk, skb_clone(skb, GFP_ATOMIC)); + return tcp_transmit_skb(sk, skb, 1, GFP_ATOMIC); } /* @@ -1861,7 +1876,7 @@ int tcp_connect(struct sock *sk) __skb_queue_tail(&sk->sk_write_queue, buff); sk_charge_skb(sk, buff); tp->packets_out += tcp_skb_pcount(buff); - tcp_transmit_skb(sk, skb_clone(buff, GFP_KERNEL)); + tcp_transmit_skb(sk, buff, 1, GFP_KERNEL); TCP_INC_STATS(TCP_MIB_ACTIVEOPENS); /* Timer for repeating the SYN until an answer. */ @@ -1957,7 +1972,7 @@ void tcp_send_ack(struct sock *sk) /* Send it off, this clears delayed acks for us. */ TCP_SKB_CB(buff)->seq = TCP_SKB_CB(buff)->end_seq = tcp_acceptable_seq(sk, tp); TCP_SKB_CB(buff)->when = tcp_time_stamp; - tcp_transmit_skb(sk, buff); + tcp_transmit_skb(sk, buff, 0, GFP_ATOMIC); } } @@ -1997,7 +2012,7 @@ static int tcp_xmit_probe_skb(struct sock *sk, int urgent) TCP_SKB_CB(skb)->seq = urgent ? tp->snd_una : tp->snd_una - 1; TCP_SKB_CB(skb)->end_seq = TCP_SKB_CB(skb)->seq; TCP_SKB_CB(skb)->when = tcp_time_stamp; - return tcp_transmit_skb(sk, skb); + return tcp_transmit_skb(sk, skb, 0, GFP_ATOMIC); } int tcp_write_wakeup(struct sock *sk) @@ -2030,7 +2045,7 @@ int tcp_write_wakeup(struct sock *sk) TCP_SKB_CB(skb)->flags |= TCPCB_FLAG_PSH; TCP_SKB_CB(skb)->when = tcp_time_stamp; - err = tcp_transmit_skb(sk, skb_clone(skb, GFP_ATOMIC)); + err = tcp_transmit_skb(sk, skb, 1, GFP_ATOMIC); if (!err) { update_send_head(sk, tp, skb); } |
