diff options
Diffstat (limited to 'net/ipv4/tcp_input.c')
| -rw-r--r-- | net/ipv4/tcp_input.c | 81 |
1 files changed, 53 insertions, 28 deletions
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c index c1ce304ba8d2..a7ef679dd3ea 100644 --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -3099,17 +3099,15 @@ static int tcp_clean_rtx_queue(struct sock *sk, int prior_fackets, if (sacked & TCPCB_SACKED_RETRANS) tp->retrans_out -= acked_pcount; flag |= FLAG_RETRANS_DATA_ACKED; - } else { + } else if (!(sacked & TCPCB_SACKED_ACKED)) { last_ackt = skb->skb_mstamp; WARN_ON_ONCE(last_ackt.v64 == 0); if (!first_ackt.v64) first_ackt = last_ackt; - if (!(sacked & TCPCB_SACKED_ACKED)) { - reord = min(pkts_acked, reord); - if (!after(scb->end_seq, tp->high_seq)) - flag |= FLAG_ORIG_SACK_ACKED; - } + reord = min(pkts_acked, reord); + if (!after(scb->end_seq, tp->high_seq)) + flag |= FLAG_ORIG_SACK_ACKED; } if (sacked & TCPCB_SACKED_ACKED) @@ -3603,6 +3601,23 @@ old_ack: return 0; } +static void tcp_parse_fastopen_option(int len, const unsigned char *cookie, + bool syn, struct tcp_fastopen_cookie *foc, + bool exp_opt) +{ + /* Valid only in SYN or SYN-ACK with an even length. */ + if (!foc || !syn || len < 0 || (len & 1)) + return; + + if (len >= TCP_FASTOPEN_COOKIE_MIN && + len <= TCP_FASTOPEN_COOKIE_MAX) + memcpy(foc->val, cookie, len); + else if (len != 0) + len = -1; + foc->len = len; + foc->exp = exp_opt; +} + /* Look for tcp options. Normally only called on SYN and SYNACK packets. * But, this can also be called on packets in the established flow when * the fast version below fails. @@ -3692,21 +3707,22 @@ void tcp_parse_options(const struct sk_buff *skb, */ break; #endif + case TCPOPT_FASTOPEN: + tcp_parse_fastopen_option( + opsize - TCPOLEN_FASTOPEN_BASE, + ptr, th->syn, foc, false); + break; + case TCPOPT_EXP: /* Fast Open option shares code 254 using a - * 16 bits magic number. It's valid only in - * SYN or SYN-ACK with an even size. + * 16 bits magic number. */ - if (opsize < TCPOLEN_EXP_FASTOPEN_BASE || - get_unaligned_be16(ptr) != TCPOPT_FASTOPEN_MAGIC || - !foc || !th->syn || (opsize & 1)) - break; - foc->len = opsize - TCPOLEN_EXP_FASTOPEN_BASE; - if (foc->len >= TCP_FASTOPEN_COOKIE_MIN && - foc->len <= TCP_FASTOPEN_COOKIE_MAX) - memcpy(foc->val, ptr + 2, foc->len); - else if (foc->len != 0) - foc->len = -1; + if (opsize >= TCPOLEN_EXP_FASTOPEN_BASE && + get_unaligned_be16(ptr) == + TCPOPT_FASTOPEN_MAGIC) + tcp_parse_fastopen_option(opsize - + TCPOLEN_EXP_FASTOPEN_BASE, + ptr + 2, th->syn, foc, true); break; } @@ -5360,8 +5376,8 @@ static bool tcp_rcv_fastopen_synack(struct sock *sk, struct sk_buff *synack, { struct tcp_sock *tp = tcp_sk(sk); struct sk_buff *data = tp->syn_data ? tcp_write_queue_head(sk) : NULL; - u16 mss = tp->rx_opt.mss_clamp; - bool syn_drop; + u16 mss = tp->rx_opt.mss_clamp, try_exp = 0; + bool syn_drop = false; if (mss == tp->rx_opt.user_mss) { struct tcp_options_received opt; @@ -5373,16 +5389,25 @@ static bool tcp_rcv_fastopen_synack(struct sock *sk, struct sk_buff *synack, mss = opt.mss_clamp; } - if (!tp->syn_fastopen) /* Ignore an unsolicited cookie */ + if (!tp->syn_fastopen) { + /* Ignore an unsolicited cookie */ cookie->len = -1; + } else if (tp->total_retrans) { + /* SYN timed out and the SYN-ACK neither has a cookie nor + * acknowledges data. Presumably the remote received only + * the retransmitted (regular) SYNs: either the original + * SYN-data or the corresponding SYN-ACK was dropped. + */ + syn_drop = (cookie->len < 0 && data); + } else if (cookie->len < 0 && !tp->syn_data) { + /* We requested a cookie but didn't get it. If we did not use + * the (old) exp opt format then try so next time (try_exp=1). + * Otherwise we go back to use the RFC7413 opt (try_exp=2). + */ + try_exp = tp->syn_fastopen_exp ? 2 : 1; + } - /* The SYN-ACK neither has cookie nor acknowledges the data. Presumably - * the remote receives only the retransmitted (regular) SYNs: either - * the original SYN-data or the corresponding SYN-ACK is lost. - */ - syn_drop = (cookie->len <= 0 && data && tp->total_retrans); - - tcp_fastopen_cache_set(sk, mss, cookie, syn_drop); + tcp_fastopen_cache_set(sk, mss, cookie, syn_drop, try_exp); if (data) { /* Retransmit unacked data in SYN */ tcp_for_write_queue_from(data, sk) { |
