diff options
Diffstat (limited to 'net/ipv4')
| -rw-r--r-- | net/ipv4/tcp.c | 68 | ||||
| -rw-r--r-- | net/ipv4/tcp_ipv4.c | 19 | ||||
| -rw-r--r-- | net/ipv4/tcp_output.c | 16 |
3 files changed, 96 insertions, 7 deletions
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c index bb4200f..e38d6f2 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -1935,7 +1935,9 @@ void tcp_close(struct sock *sk, long timeout) * advertise a zero window, then kill -9 the FTP client, wheee... * Note: timeout is always zero in such a case. */ - if (data_was_unread) { + if (unlikely(tcp_sk(sk)->repair)) { + sk->sk_prot->disconnect(sk, 0); + } else if (data_was_unread) { /* Unread data was tossed, zap the connection. */ NET_INC_STATS_USER(sock_net(sk), LINUX_MIB_TCPABORTONCLOSE); tcp_set_state(sk, TCP_CLOSE); @@ -2074,6 +2076,8 @@ int tcp_disconnect(struct sock *sk, int flags) /* ABORT function of RFC793 */ if (old_state == TCP_LISTEN) { inet_csk_listen_stop(sk); + } else if (unlikely(tp->repair)) { + sk->sk_err = ECONNABORTED; } else if (tcp_need_reset(old_state) || (tp->snd_nxt != tp->write_seq && (1 << old_state) & (TCPF_CLOSING | TCPF_LAST_ACK))) { @@ -2125,6 +2129,12 @@ int tcp_disconnect(struct sock *sk, int flags) } EXPORT_SYMBOL(tcp_disconnect); +static inline int tcp_can_repair_sock(struct sock *sk) +{ + return capable(CAP_NET_ADMIN) && + ((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_ESTABLISHED)); +} + /* * Socket option code for TCP. */ @@ -2297,6 +2307,42 @@ static int do_tcp_setsockopt(struct sock *sk, int level, tp->thin_dupack = val; break; + case TCP_REPAIR: + if (!tcp_can_repair_sock(sk)) + err = -EPERM; + else if (val == 1) { + tp->repair = 1; + sk->sk_reuse = SK_FORCE_REUSE; + tp->repair_queue = TCP_NO_QUEUE; + } else if (val == 0) { + tp->repair = 0; + sk->sk_reuse = SK_NO_REUSE; + tcp_send_window_probe(sk); + } else + err = -EINVAL; + + break; + + case TCP_REPAIR_QUEUE: + if (!tp->repair) + err = -EPERM; + else if (val < TCP_QUEUES_NR) + tp->repair_queue = val; + else + err = -EINVAL; + break; + + case TCP_QUEUE_SEQ: + if (sk->sk_state != TCP_CLOSE) + err = -EPERM; + else if (tp->repair_queue == TCP_SEND_QUEUE) + tp->write_seq = val; + else if (tp->repair_queue == TCP_RECV_QUEUE) + tp->rcv_nxt = val; + else + err = -EINVAL; + break; + case TCP_CORK: /* When set indicates to always queue non-full frames. * Later the user clears this option and we transmit @@ -2632,6 +2678,26 @@ static int do_tcp_getsockopt(struct sock *sk, int level, val = tp->thin_dupack; break; + case TCP_REPAIR: + val = tp->repair; + break; + + case TCP_REPAIR_QUEUE: + if (tp->repair) + val = tp->repair_queue; + else + return -EINVAL; + break; + + case TCP_QUEUE_SEQ: + if (tp->repair_queue == TCP_SEND_QUEUE) + val = tp->write_seq; + else if (tp->repair_queue == TCP_RECV_QUEUE) + val = tp->rcv_nxt; + else + return -EINVAL; + break; + case TCP_USER_TIMEOUT: val = jiffies_to_msecs(icsk->icsk_user_timeout); break; diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c index 0cb86ce..ba6dad8 100644 --- a/net/ipv4/tcp_ipv4.c +++ b/net/ipv4/tcp_ipv4.c @@ -138,6 +138,14 @@ int tcp_twsk_unique(struct sock *sk, struct sock *sktw, void *twp) } EXPORT_SYMBOL_GPL(tcp_twsk_unique); +static int tcp_repair_connect(struct sock *sk) +{ + tcp_connect_init(sk); + tcp_finish_connect(sk, NULL); + + return 0; +} + /* This will initiate an outgoing connection. */ int tcp_v4_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len) { @@ -196,7 +204,8 @@ int tcp_v4_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len) /* Reset inherited state */ tp->rx_opt.ts_recent = 0; tp->rx_opt.ts_recent_stamp = 0; - tp->write_seq = 0; + if (likely(!tp->repair)) + tp->write_seq = 0; } if (tcp_death_row.sysctl_tw_recycle && @@ -247,7 +256,7 @@ int tcp_v4_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len) sk->sk_gso_type = SKB_GSO_TCPV4; sk_setup_caps(sk, &rt->dst); - if (!tp->write_seq) + if (!tp->write_seq && likely(!tp->repair)) tp->write_seq = secure_tcp_sequence_number(inet->inet_saddr, inet->inet_daddr, inet->inet_sport, @@ -255,7 +264,11 @@ int tcp_v4_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len) inet->inet_id = tp->write_seq ^ jiffies; - err = tcp_connect(sk); + if (likely(!tp->repair)) + err = tcp_connect(sk); + else + err = tcp_repair_connect(sk); + rt = NULL; if (err) goto failure; diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c index db126a6..fa442a6 100644 --- a/net/ipv4/tcp_output.c +++ b/net/ipv4/tcp_output.c @@ -2617,9 +2617,11 @@ void tcp_connect_init(struct sock *sk) tp->snd_sml = tp->write_seq; tp->snd_up = tp->write_seq; tp->snd_nxt = tp->write_seq; - tp->rcv_nxt = 0; - tp->rcv_wup = 0; - tp->copied_seq = 0; + + if (likely(!tp->repair)) + tp->rcv_nxt = 0; + tp->rcv_wup = tp->rcv_nxt; + tp->copied_seq = tp->rcv_nxt; inet_csk(sk)->icsk_rto = TCP_TIMEOUT_INIT; inet_csk(sk)->icsk_retransmits = 0; @@ -2790,6 +2792,14 @@ static int tcp_xmit_probe_skb(struct sock *sk, int urgent) return tcp_transmit_skb(sk, skb, 0, GFP_ATOMIC); } +void tcp_send_window_probe(struct sock *sk) +{ + if (sk->sk_state == TCP_ESTABLISHED) { + tcp_sk(sk)->snd_wl1 = tcp_sk(sk)->rcv_nxt - 1; + tcp_xmit_probe_skb(sk, 0); + } +} + /* Initiate keepalive or window probe from timer. */ int tcp_write_wakeup(struct sock *sk) { |