From b4b7ff4b08e691656c9d77c758fc355833128ac0 Mon Sep 17 00:00:00 2001 From: André Fabian Silva Delgado Date: Wed, 20 Jan 2016 14:01:31 -0300 Subject: Linux-libre 4.4-gnu --- net/ipv4/tcp_output.c | 107 ++++++++++++++++++++++++++------------------------ 1 file changed, 56 insertions(+), 51 deletions(-) (limited to 'net/ipv4/tcp_output.c') diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c index f5ecbbbc6..fac7cd5c7 100644 --- a/net/ipv4/tcp_output.c +++ b/net/ipv4/tcp_output.c @@ -357,14 +357,10 @@ static void tcp_ecn_clear_syn(struct sock *sk, struct sk_buff *skb) } static void -tcp_ecn_make_synack(const struct request_sock *req, struct tcphdr *th, - struct sock *sk) +tcp_ecn_make_synack(const struct request_sock *req, struct tcphdr *th) { - if (inet_rsk(req)->ecn_ok) { + if (inet_rsk(req)->ecn_ok) th->ece = 1; - if (tcp_ca_needs_ecn(sk)) - INET_ECN_xmit(sk); - } } /* Set up ECN state for a packet on a ESTABLISHED socket that is about to @@ -612,12 +608,11 @@ static unsigned int tcp_syn_options(struct sock *sk, struct sk_buff *skb, } /* Set up TCP options for SYN-ACKs. */ -static unsigned int tcp_synack_options(struct sock *sk, - struct request_sock *req, - unsigned int mss, struct sk_buff *skb, - struct tcp_out_options *opts, - const struct tcp_md5sig_key *md5, - struct tcp_fastopen_cookie *foc) +static unsigned int tcp_synack_options(struct request_sock *req, + unsigned int mss, struct sk_buff *skb, + struct tcp_out_options *opts, + const struct tcp_md5sig_key *md5, + struct tcp_fastopen_cookie *foc) { struct inet_request_sock *ireq = inet_rsk(req); unsigned int remaining = MAX_TCP_OPTION_SPACE; @@ -1834,7 +1829,7 @@ static bool tcp_tso_should_defer(struct sock *sk, struct sk_buff *skb, /* Ok, it looks like it is advisable to defer. */ - if (cong_win < send_win && cong_win < skb->len) + if (cong_win < send_win && cong_win <= skb->len) *is_cwnd_limited = true; return true; @@ -2067,7 +2062,6 @@ static bool tcp_write_xmit(struct sock *sk, unsigned int mss_now, int nonagle, cwnd_quota = tcp_cwnd_test(tp, skb); if (!cwnd_quota) { - is_cwnd_limited = true; if (push_one == 2) /* Force out a loss probe pkt. */ cwnd_quota = 1; @@ -2149,6 +2143,7 @@ repair: /* Send one loss probe per tail loss episode. */ if (push_one != 2) tcp_schedule_loss_probe(sk); + is_cwnd_limited |= (tcp_packets_in_flight(tp) >= tp->snd_cwnd); tcp_cwnd_validate(sk, is_cwnd_limited); return false; } @@ -2172,7 +2167,7 @@ bool tcp_schedule_loss_probe(struct sock *sk) /* Don't do any loss probe on a Fast Open connection before 3WHS * finishes. */ - if (sk->sk_state == TCP_SYN_RECV) + if (tp->fastopen_rsk) return false; /* TLP is only scheduled when next timer event is RTO. */ @@ -2182,7 +2177,7 @@ bool tcp_schedule_loss_probe(struct sock *sk) /* Schedule a loss probe in 2*RTT for SACK capable connections * in Open state, that are either limited by cwnd or application. */ - if (sysctl_tcp_early_retrans < 3 || !tp->srtt_us || !tp->packets_out || + if (sysctl_tcp_early_retrans < 3 || !tp->packets_out || !tcp_is_sack(tp) || inet_csk(sk)->icsk_ca_state != TCP_CA_Open) return false; @@ -2191,9 +2186,10 @@ bool tcp_schedule_loss_probe(struct sock *sk) return false; /* Probe timeout is at least 1.5*rtt + TCP_DELACK_MAX to account - * for delayed ack when there's one outstanding packet. + * for delayed ack when there's one outstanding packet. If no RTT + * sample is available then probe after TCP_TIMEOUT_INIT. */ - timeout = rtt << 1; + timeout = rtt << 1 ? : TCP_TIMEOUT_INIT; if (tp->packets_out == 1) timeout = max_t(u32, timeout, (rtt + (rtt >> 1) + TCP_DELACK_MAX)); @@ -2666,8 +2662,6 @@ int tcp_retransmit_skb(struct sock *sk, struct sk_buff *skb) net_dbg_ratelimited("retrans_out leaked\n"); } #endif - if (!tp->retrans_out) - tp->lost_retrans_low = tp->snd_nxt; TCP_SKB_CB(skb)->sacked |= TCPCB_RETRANS; tp->retrans_out += tcp_skb_pcount(skb); @@ -2675,10 +2669,6 @@ int tcp_retransmit_skb(struct sock *sk, struct sk_buff *skb) if (!tp->retrans_stamp) tp->retrans_stamp = tcp_skb_timestamp(skb); - /* snd_nxt is stored to detect loss of retransmitted segment, - * see tcp_input.c tcp_sacktag_write_queue(). - */ - TCP_SKB_CB(skb)->ack_seq = tp->snd_nxt; } else if (err != -EBUSY) { NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPRETRANSFAIL); } @@ -2956,20 +2946,22 @@ int tcp_send_synack(struct sock *sk) * Allocate one skb and build a SYNACK packet. * @dst is consumed : Caller should not use it again. */ -struct sk_buff *tcp_make_synack(struct sock *sk, struct dst_entry *dst, +struct sk_buff *tcp_make_synack(const struct sock *sk, struct dst_entry *dst, struct request_sock *req, - struct tcp_fastopen_cookie *foc) + struct tcp_fastopen_cookie *foc, + bool attach_req) { - struct tcp_out_options opts; struct inet_request_sock *ireq = inet_rsk(req); - struct tcp_sock *tp = tcp_sk(sk); - struct tcphdr *th; - struct sk_buff *skb; + const struct tcp_sock *tp = tcp_sk(sk); struct tcp_md5sig_key *md5 = NULL; + struct tcp_out_options opts; + struct sk_buff *skb; int tcp_header_size; + struct tcphdr *th; + u16 user_mss; int mss; - skb = sock_wmalloc(sk, MAX_TCP_HEADER, 1, GFP_ATOMIC); + skb = alloc_skb(MAX_TCP_HEADER, GFP_ATOMIC); if (unlikely(!skb)) { dst_release(dst); return NULL; @@ -2977,11 +2969,21 @@ struct sk_buff *tcp_make_synack(struct sock *sk, struct dst_entry *dst, /* Reserve space for headers. */ skb_reserve(skb, MAX_TCP_HEADER); + if (attach_req) { + skb_set_owner_w(skb, req_to_sk(req)); + } else { + /* sk is a const pointer, because we want to express multiple + * cpu might call us concurrently. + * sk->sk_wmem_alloc in an atomic, we can promote to rw. + */ + skb_set_owner_w(skb, (struct sock *)sk); + } skb_dst_set(skb, dst); mss = dst_metric_advmss(dst); - if (tp->rx_opt.user_mss && tp->rx_opt.user_mss < mss) - mss = tp->rx_opt.user_mss; + user_mss = READ_ONCE(tp->rx_opt.user_mss); + if (user_mss && user_mss < mss) + mss = user_mss; memset(&opts, 0, sizeof(opts)); #ifdef CONFIG_SYN_COOKIES @@ -2995,8 +2997,9 @@ struct sk_buff *tcp_make_synack(struct sock *sk, struct dst_entry *dst, rcu_read_lock(); md5 = tcp_rsk(req)->af_specific->req_md5_lookup(sk, req_to_sk(req)); #endif - tcp_header_size = tcp_synack_options(sk, req, mss, skb, &opts, md5, - foc) + sizeof(*th); + skb_set_hash(skb, tcp_rsk(req)->txhash, PKT_HASH_TYPE_L4); + tcp_header_size = tcp_synack_options(req, mss, skb, &opts, md5, foc) + + sizeof(*th); skb_push(skb, tcp_header_size); skb_reset_transport_header(skb); @@ -3005,7 +3008,7 @@ struct sk_buff *tcp_make_synack(struct sock *sk, struct dst_entry *dst, memset(th, 0, sizeof(struct tcphdr)); th->syn = 1; th->ack = 1; - tcp_ecn_make_synack(req, th, sk); + tcp_ecn_make_synack(req, th); th->source = htons(ireq->ir_num); th->dest = ireq->ir_rmt_port; /* Setting of flags are superfluous here for callers (and ECE is @@ -3019,8 +3022,8 @@ struct sk_buff *tcp_make_synack(struct sock *sk, struct dst_entry *dst, th->ack_seq = htonl(tcp_rsk(req)->rcv_nxt); /* RFC1323: The window in SYN & SYN/ACK segments is never scaled. */ - th->window = htons(min(req->rcv_wnd, 65535U)); - tcp_options_write((__be32 *)(th + 1), tp, &opts); + th->window = htons(min(req->rsk_rcv_wnd, 65535U)); + tcp_options_write((__be32 *)(th + 1), NULL, &opts); th->doff = (tcp_header_size >> 2); TCP_INC_STATS_BH(sock_net(sk), TCP_MIB_OUTSEGS); @@ -3154,7 +3157,7 @@ static int tcp_send_syn_data(struct sock *sk, struct sk_buff *syn) { struct tcp_sock *tp = tcp_sk(sk); struct tcp_fastopen_request *fo = tp->fastopen_req; - int syn_loss = 0, space, err = 0, copied; + int syn_loss = 0, space, err = 0; unsigned long last_syn_loss = 0; struct sk_buff *syn_data; @@ -3192,17 +3195,18 @@ static int tcp_send_syn_data(struct sock *sk, struct sk_buff *syn) goto fallback; syn_data->ip_summed = CHECKSUM_PARTIAL; memcpy(syn_data->cb, syn->cb, sizeof(syn->cb)); - copied = copy_from_iter(skb_put(syn_data, space), space, - &fo->data->msg_iter); - if (unlikely(!copied)) { - kfree_skb(syn_data); - goto fallback; - } - if (copied != space) { - skb_trim(syn_data, copied); - space = copied; + if (space) { + int copied = copy_from_iter(skb_put(syn_data, space), space, + &fo->data->msg_iter); + if (unlikely(!copied)) { + kfree_skb(syn_data); + goto fallback; + } + if (copied != space) { + skb_trim(syn_data, copied); + space = copied; + } } - /* No more data pending in inet_wait_for_connect() */ if (space == fo->size) fo->data = NULL; @@ -3515,13 +3519,14 @@ void tcp_send_probe0(struct sock *sk) TCP_RTO_MAX); } -int tcp_rtx_synack(struct sock *sk, struct request_sock *req) +int tcp_rtx_synack(const struct sock *sk, struct request_sock *req) { const struct tcp_request_sock_ops *af_ops = tcp_rsk(req)->af_specific; struct flowi fl; int res; - res = af_ops->send_synack(sk, NULL, &fl, req, 0, NULL); + tcp_rsk(req)->txhash = net_tx_rndhash(); + res = af_ops->send_synack(sk, NULL, &fl, req, NULL, true); if (!res) { TCP_INC_STATS_BH(sock_net(sk), TCP_MIB_RETRANSSEGS); NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPSYNRETRANS); 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