[DCCP]: Integration of dynamic feature activation - part 3 (client side)
This integrates feature-activation in the client, the following details needed
to be addressed:
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 first packet with an Ack number that the
client gets,
* so when dccp_ackvec_add() fails, the reason is likely not due to a packet
error.
There is another problem: when a connecting client sends a Reset in state
REQUEST, the loop
in dccp_sendmsg(), which waits in sk_stream_wait_connect() for the
transition to PARTOPEN,
does not (and will not) happen. The same problem also occurs if the feature
negotiation
during connection setup fails. Thus I have lumped this case together with
the following:
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.
Since this addresses congestion-control initialisation, a corresponding FIXME
has been removed.
Signed-off-by: Gerrit Renker <[EMAIL PROTECTED]>
---
net/dccp/input.c | 28 ++++++++++++++++++++++++----
1 file changed, 24 insertions(+), 4 deletions(-)
--- a/net/dccp/input.c
+++ b/net/dccp/input.c
@@ -382,8 +382,13 @@ static int dccp_rcv_request_sent_state_p
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))
@@ -394,7 +399,7 @@ static int dccp_rcv_request_sent_state_p
dccp_ackvec_add(dp->dccps_hc_rx_ackvec, sk,
DCCP_SKB_CB(skb)->dccpd_seq,
DCCP_ACKVEC_STATE_RECEIVED))
- goto out_invalid_packet; /* FIXME: change error code */
+ goto unable_to_proceed;
dp->dccps_isr = DCCP_SKB_CB(skb)->dccpd_seq;
dccp_update_gsr(sk, dp->dccps_isr);
@@ -456,6 +461,13 @@ static int dccp_rcv_request_sent_state_p
__kfree_skb(skb);
return 0;
}
+ /*
+ * If feature negotiation throws an error, we can not proceed
+ * (one or more feature values are undefined), so we send a
+ * Reset. Otherwise, the Ack will clear any pending Confirms.
+ */
+ if (dccp_feat_activate_values(sk, &dp->dccps_featneg))
+ goto unable_to_proceed;
dccp_send_ack(sk);
return -1;
}
@@ -464,6 +476,16 @@ 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,
@@ -621,8 +643,6 @@ int dccp_rcv_state_process(struct sock *
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;
-
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