From c49b22729f3da7479c4e6c572d53fdd40201d0bd Mon Sep 17 00:00:00 2001 From: Gerrit Renker Date: Thu, 4 Sep 2008 07:30:19 +0200 Subject: dccp: Integration of dynamic feature activation - part 3 (client side) This integrates feature-activation in the client, with these details: 1. When dccp_parse_options() fails, the reset code is already set, request_sent _state_process() currently overrides this with `Packet Error', which is not intended - so changed to use the reset code set in dccp_parse_options(); 2. There was a FIXME to change the error code when dccp_ackvec_add() fails. I have looked this up and found that: * the check whether ackno < ISN is already made earlier, * this Response is likely the 1st packet with an Ackno that the client gets, * so when dccp_ackvec_add() fails, the reason is likely not a packet error. 3. When feature negotiation fails, the socket should be marked as not usable, so that the application is notified that an error occurs. This is achieved by a new label, which uses an error code of `Aborted' and which sets the socket state to CLOSED, as well as sk_err. 4. Avoids parsing the Ack twice in Respond state by not doing option processing again in dccp_rcv_respond_partopen_state_process (as option processing has already been done on the request_sock in dccp_check_req). Since this addresses congestion-control initialisation, a corresponding FIXME has been removed. Signed-off-by: Gerrit Renker Acked-by: Ian McDonald --- net/dccp/input.c | 30 ++++++++++++++++++++++++++---- 1 file changed, 26 insertions(+), 4 deletions(-) (limited to 'net/dccp/input.c') diff --git a/net/dccp/input.c b/net/dccp/input.c index 3070015edc7..0672b7e1763 100644 --- a/net/dccp/input.c +++ b/net/dccp/input.c @@ -421,8 +421,13 @@ static int dccp_rcv_request_sent_state_process(struct sock *sk, goto out_invalid_packet; } + /* + * If option processing (Step 8) failed, return 1 here so that + * dccp_v4_do_rcv() sends a Reset. The Reset code depends on + * the option type and is set in dccp_parse_options(). + */ if (dccp_parse_options(sk, NULL, skb)) - goto out_invalid_packet; + return 1; /* Obtain usec RTT sample from SYN exchange (used by CCID 3) */ if (likely(dp->dccps_options_received.dccpor_timestamp_echo)) @@ -475,6 +480,15 @@ static int dccp_rcv_request_sent_state_process(struct sock *sk, */ dccp_set_state(sk, DCCP_PARTOPEN); + /* + * If feature negotiation was successful, activate features now; + * an activation failure means that this host could not activate + * one ore more features (e.g. insufficient memory), which would + * leave at least one feature in an undefined state. + */ + if (dccp_feat_activate_values(sk, &dp->dccps_featneg)) + goto unable_to_proceed; + /* Make sure socket is routed, for correct metrics. */ icsk->icsk_af_ops->rebuild_header(sk); @@ -509,6 +523,16 @@ out_invalid_packet: /* dccp_v4_do_rcv will send a reset */ DCCP_SKB_CB(skb)->dccpd_reset_code = DCCP_RESET_CODE_PACKET_ERROR; return 1; + +unable_to_proceed: + DCCP_SKB_CB(skb)->dccpd_reset_code = DCCP_RESET_CODE_ABORTED; + /* + * We mark this socket as no longer usable, so that the loop in + * dccp_sendmsg() terminates and the application gets notified. + */ + dccp_set_state(sk, DCCP_CLOSED); + sk->sk_err = ECOMM; + return 1; } static int dccp_rcv_respond_partopen_state_process(struct sock *sk, @@ -600,7 +624,7 @@ int dccp_rcv_state_process(struct sock *sk, struct sk_buff *skb, return 1; } - if (sk->sk_state != DCCP_REQUESTING) { + if (sk->sk_state != DCCP_REQUESTING && sk->sk_state != DCCP_RESPOND) { if (dccp_check_seqno(sk, skb)) goto discard; @@ -665,8 +689,6 @@ int dccp_rcv_state_process(struct sock *sk, struct sk_buff *skb, return 1; case DCCP_REQUESTING: - /* FIXME: do congestion control initialization */ - queued = dccp_rcv_request_sent_state_process(sk, skb, dh, len); if (queued >= 0) return queued; -- cgit v1.2.3