diff options
Diffstat (limited to 'net/dccp/input.c')
| -rw-r--r-- | net/dccp/input.c | 88 |
1 files changed, 73 insertions, 15 deletions
diff --git a/net/dccp/input.c b/net/dccp/input.c index ef299fbd7c26..fe4b0fbfa508 100644 --- a/net/dccp/input.c +++ b/net/dccp/input.c @@ -32,16 +32,56 @@ static void dccp_fin(struct sock *sk, struct sk_buff *skb) sk->sk_data_ready(sk, 0); } -static void dccp_rcv_close(struct sock *sk, struct sk_buff *skb) +static int dccp_rcv_close(struct sock *sk, struct sk_buff *skb) { - dccp_send_reset(sk, DCCP_RESET_CODE_CLOSED); - dccp_fin(sk, skb); - dccp_set_state(sk, DCCP_CLOSED); - sk_wake_async(sk, SOCK_WAKE_WAITD, POLL_HUP); + int queued = 0; + + switch (sk->sk_state) { + /* + * We ignore Close when received in one of the following states: + * - CLOSED (may be a late or duplicate packet) + * - PASSIVE_CLOSEREQ (the peer has sent a CloseReq earlier) + * - RESPOND (already handled by dccp_check_req) + */ + case DCCP_CLOSING: + /* + * Simultaneous-close: receiving a Close after sending one. This + * can happen if both client and server perform active-close and + * will result in an endless ping-pong of crossing and retrans- + * mitted Close packets, which only terminates when one of the + * nodes times out (min. 64 seconds). Quicker convergence can be + * achieved when one of the nodes acts as tie-breaker. + * This is ok as both ends are done with data transfer and each + * end is just waiting for the other to acknowledge termination. + */ + if (dccp_sk(sk)->dccps_role != DCCP_ROLE_CLIENT) + break; + /* fall through */ + case DCCP_REQUESTING: + case DCCP_ACTIVE_CLOSEREQ: + dccp_send_reset(sk, DCCP_RESET_CODE_CLOSED); + dccp_done(sk); + break; + case DCCP_OPEN: + case DCCP_PARTOPEN: + /* Give waiting application a chance to read pending data */ + queued = 1; + dccp_fin(sk, skb); + dccp_set_state(sk, DCCP_PASSIVE_CLOSE); + /* fall through */ + case DCCP_PASSIVE_CLOSE: + /* + * Retransmitted Close: we have already enqueued the first one. + */ + sk_wake_async(sk, SOCK_WAKE_WAITD, POLL_HUP); + } + return queued; } -static void dccp_rcv_closereq(struct sock *sk, struct sk_buff *skb) +static int dccp_rcv_closereq(struct sock *sk, struct sk_buff *skb) { + int queued = 0; + /* * Step 7: Check for unexpected packet types * If (S.is_server and P.type == CloseReq) @@ -50,12 +90,26 @@ static void dccp_rcv_closereq(struct sock *sk, struct sk_buff *skb) */ if (dccp_sk(sk)->dccps_role != DCCP_ROLE_CLIENT) { dccp_send_sync(sk, DCCP_SKB_CB(skb)->dccpd_seq, DCCP_PKT_SYNC); - return; + return queued; } - if (sk->sk_state != DCCP_CLOSING) + /* Step 13: process relevant Client states < CLOSEREQ */ + switch (sk->sk_state) { + case DCCP_REQUESTING: + dccp_send_close(sk, 0); dccp_set_state(sk, DCCP_CLOSING); - dccp_send_close(sk, 0); + break; + case DCCP_OPEN: + case DCCP_PARTOPEN: + /* Give waiting application a chance to read pending data */ + queued = 1; + dccp_fin(sk, skb); + dccp_set_state(sk, DCCP_PASSIVE_CLOSEREQ); + /* fall through */ + case DCCP_PASSIVE_CLOSEREQ: + sk_wake_async(sk, SOCK_WAKE_WAITD, POLL_HUP); + } + return queued; } static u8 dccp_reset_code_convert(const u8 code) @@ -247,11 +301,13 @@ static int __dccp_rcv_established(struct sock *sk, struct sk_buff *skb, dccp_rcv_reset(sk, skb); return 0; case DCCP_PKT_CLOSEREQ: - dccp_rcv_closereq(sk, skb); + if (dccp_rcv_closereq(sk, skb)) + return 0; goto discard; case DCCP_PKT_CLOSE: - dccp_rcv_close(sk, skb); - return 0; + if (dccp_rcv_close(sk, skb)) + return 0; + goto discard; case DCCP_PKT_REQUEST: /* Step 7 * or (S.is_server and P.type == Response) @@ -590,11 +646,13 @@ int dccp_rcv_state_process(struct sock *sk, struct sk_buff *skb, dccp_send_sync(sk, dcb->dccpd_seq, DCCP_PKT_SYNC); goto discard; } else if (dh->dccph_type == DCCP_PKT_CLOSEREQ) { - dccp_rcv_closereq(sk, skb); + if (dccp_rcv_closereq(sk, skb)) + return 0; goto discard; } else if (dh->dccph_type == DCCP_PKT_CLOSE) { - dccp_rcv_close(sk, skb); - return 0; + if (dccp_rcv_close(sk, skb)) + return 0; + goto discard; } switch (sk->sk_state) { |