On 05/19/2010 07:05 AM, Amos Jeffries wrote:
> Henrik Nordström wrote:
>> tis 2010-05-18 klockan 23:34 +0000 skrev Amos Jeffries:
>>
>>> I've discovered the VC connections in DNS will need a re-working to
>>> handle
>>> the new TCP connection setup handling. I've left that for now since it
>>> appears that you are working on redesigning that area anyway. The new
>>> setup
>>> routines will play VERY nicely with persistent TCP links to the
>>> nameservers.
>>
>> I have not started on the DNS rewrite yet.
>>
>>> I took some extra time last night and broke the back of the selection
>>> and
>>> forwarding rewrite. I'm now down to the fine detail build errors. When
>>> those are done I'll push the branch to LP for you to do the DNS fixes on
>>> top of.
>>
>> Ok.
>>
>
> Pushed to launchpad: lp:~yadi/squid/cleanup-comm
How can I review the changes as one patch without checking out your branch?
Thank you,
Alex.
> This builds, but has not yet been run tested.
>
> What has changed:
>
> ConnectionDetails objects have been renamed Comm::Connection and been
> extended to hold the FD and Squids' socket flags.
>
> Peer selection has been extended to do DNS lookups on the peers chosen
> for forwarding to and produce a vector<> of possible connection
> endpoints (squid local IP via tcp_outgoing_address or tproxy) and remote
> server.
>
> Various connection openers have been converted to use the new
> ConnectStateData API and CommCalls (function based so far).
>
>
> ConnectStateData has been moved into src/comm/ (not yet namespaced) and
> had all its DNS lookup operations dropped. To be replaced by a looping
> process of attempting to open a socket and join a link as described by
> some Comm::Connection or vector<> of same.
>
> ConnectStateData::connect() will go away and do some async work. Will
> come back at some point by calling the handler with COMM_OK,
> COMM_ERR_CONNECT, COMM_TIMEOUT and ptrs to the Comm::Connection or
> vector (whichever were passed in).
> On COMM_OK the Comm::Connection pointer or the first entry of the
> vector will be an open conn which we can now use.
> On COMM_ERR_CONNECT the vector will be empty (all tried and
> discarded), the single ptr will be closed if not NULL.
> On COMM_TIMEOUT their content is as per COMM_ERR_CONNECT but the vector
> may have untried paths still present but closed.
>
> FD opening, FD problems, connection errors, timeouts, early remote
> TCP_RST or NACK closure during the setup are all now wrapped out of
> sight inside ConnectStateData.
>
> The main-level component may set FD handlers as needed for read/write
> and closure of the link in their connection-done handler where the FD
> first becomes visible to them.
>
>
> Besides the testing there is some work to:
> * make it obey squid.conf limits on retries and paths looked up.
> * make DNS TCP links ('VC') work again.
> * make the CommCalls proper AsynCalls and not function handler based.
> * make Comm::Connection ref-counted so we can have them stored
> in the peer details and further reduce the DNS steps.
> * make ICAP do DNS lookups to set its server Comm::Connection properly.
> For now it's stuck with the gethostbyname() blocking lookup.
>
>
> Future work once this is stable is to:
> a) push the IDENT, NAT, EUI and TLS operations down into the Comm layer
> with simple flags for other layers to turn them on/off as desired.
> b) make the general code pass Comm::Connection around so everything
> like ACLs can access the client and server conn when they need to.
>
> Amos
