litmus2008.git/net/dccp, branch master

[DCCP]: Spelling fixes

2007-12-20T21:59:39+00:00

Signed-off-by: Joe Perches 
Signed-off-by: David S. Miller

[DCCP]: Add missing "space"

2007-11-20T07:46:02+00:00

Signed-off-by: Joe Perches 
Signed-off-by: David S. Miller

[INET]: Remove per bucket rwlock in tcp/dccp ehash table.

2007-11-07T12:15:11+00:00

As done two years ago on IP route cache table (commit
22c047ccbc68fa8f3fa57f0e8f906479a062c426) , we can avoid using one
lock per hash bucket for the huge TCP/DCCP hash tables.

On a typical x86_64 platform, this saves about 2MB or 4MB of ram, for
litle performance differences. (we hit a different cache line for the
rwlock, but then the bucket cache line have a better sharing factor
among cpus, since we dirty it less often). For netstat or ss commands
that want a full scan of hash table, we perform fewer memory accesses.

Using a 'small' table of hashed rwlocks should be more than enough to
provide correct SMP concurrency between different buckets, without
using too much memory. Sizing of this table depends on
num_possible_cpus() and various CONFIG settings.

This patch provides some locking abstraction that may ease a future
work using a different model for TCP/DCCP table.

Signed-off-by: Eric Dumazet 
Acked-by: Arnaldo Carvalho de Melo 
Signed-off-by: David S. Miller

[DCCP]: Use DEFINE_PROTO_INUSE infrastructure.

2007-11-07T12:09:01+00:00

Signed-off-by: David S. Miller

[CCID2/3]: Initialisation assignments of 0 are redundant

2007-10-24T12:53:01+00:00

Assigning initial values of `0' is redundant when loading a new CCID structure,
since in net/dccp/ccid.c the entire CCID structure is zeroed out prior to
initialisation in ccid_new():

    	struct ccid {
    		struct ccid_operations *ccid_ops;
    		char		       ccid_priv[0];
    	};

    	// ...
    	if (rx) {
    		memset(ccid + 1, 0, ccid_ops->ccid_hc_rx_obj_size);
    		if (ccid->ccid_ops->ccid_hc_rx_init != NULL &&
    		    ccid->ccid_ops->ccid_hc_rx_init(ccid, sk) != 0)
    			goto out_free_ccid;
    	} else {
    		memset(ccid + 1, 0, ccid_ops->ccid_hc_tx_obj_size);
    		/* analogous to the rx case */
    	}

This patch therefore removes the redundant assignments. Thanks to Arnaldo for
the inspiration.

Signed-off-by: Gerrit Renker 
Signed-off-by: Ian McDonald 
Signed-off-by: Arnaldo Carvalho de Melo

[DCCP]: Unaligned pointer access

2007-10-24T12:46:58+00:00

This fixes `unaligned (read) access' errors of the type

Kernel unaligned access at TPC[100f970c] dccp_parse_options+0x4f4/0x7e0 [dccp]
Kernel unaligned access at TPC[1011f2e4] ccid3_hc_tx_parse_options+0x1ac/0x380 [dccp_ccid3]
Kernel unaligned access at TPC[100f9898] dccp_parse_options+0x680/0x880 [dccp]

by using the get_unaligned macro for parsing options.

Commiter note: Preserved the sparse __be{16,32} annotations.

Signed-off-by: Gerrit Renker 
Signed-off-by: Ian McDonald 
Signed-off-by: Arnaldo Carvalho de Melo

[DCCP]: Convert Reset code into socket error number

2007-10-24T12:27:48+00:00

This adds support for converting the 11 currently defined Reset codes into system
error numbers, which are stored in sk_err for further interpretation.

This makes the externally visible API behaviour similar to TCP, since a client
connecting to a non-existing port will experience ECONNREFUSED.

* Code 0, Unspecified, is interpreted as non-error (0);
* Code 1, Closed (normal termination), also maps into 0;
* Code 2, Aborted, maps into "Connection reset by peer" (ECONNRESET);
* Code 3, No Connection and
  Code 7, Connection Refused, map into "Connection refused" (ECONNREFUSED);
* Code 4, Packet Error, maps into "No message of desired type" (ENOMSG);
* Code 5, Option Error, maps into "Illegal byte sequence" (EILSEQ);
* Code 6, Mandatory Error, maps into "Operation not supported on transport endpoint" (EOPNOTSUPP);
* Code 8, Bad Service Code, maps into "Invalid request code" (EBADRQC);
* Code 9, Too Busy, maps into "Too many users" (EUSERS);
* Code 10, Bad Init Cookie, maps into "Invalid request descriptor" (EBADR);
* Code 11, Aggression Penalty, maps into "Quota exceeded" (EDQUOT)
  which makes sense in terms of using more than the `fair share' of bandwidth.

Signed-off-by: Gerrit Renker 
Acked-by: Ian McDonald 
Signed-off-by: Arnaldo Carvalho de Melo

[DCCP]: One more exemption from full sequence number checks

2007-10-24T12:18:06+00:00

This fixes the following problem: client connects to peer which has no DCCP
enabled or loaded; ICMP error messages ("Protocol Unavailable") can be seen
on the wire, but the application hangs. Reason: ICMP packets don't get through
to dccp_v4_err.

When reporting errors, a sequence number check is made for the DCCP packet
that had caused an ICMP error to arrive.
Such checks can not be made if the socket is in state LISTEN, RESPOND (which
in the implementation is the same as LISTEN), or REQUEST, since update_gsr()
has not been called in these states, hence the sequence window is 0..0.

This patch fixes the problem by adding the REQUEST state as another exemption
to the window check. The error reporting now works as expected on connecting.

Signed-off-by: Gerrit Renker 
Acked-by: Ian McDonald 
Signed-off-by: Arnaldo Carvalho de Melo

[DCCP]: Retrieve packet sequence number for error reporting

2007-10-24T12:12:09+00:00

This fixes a problem when analysing erroneous packets in dccp_v{4,6}_err:
* dccp_hdr_seq currently takes an skb
* however, the transport headers in the skb are shifted, due to the
  preceding IPv4/v6 header.
Fixed for v4 and v6 by changing dccp_hdr_seq to take a struct dccp_hdr as
argument. Verified that the correct sequence number is now reported in the
error handler.

Signed-off-by: Gerrit Renker 
Acked-by: Ian McDonald 
Signed-off-by: Arnaldo Carvalho de Melo

[DCCP]: Implement SIOCINQ/FIONREAD

2007-10-24T04:27:50+00:00

Just like UDP.

Signed-off-by: Arnaldo Carvalho de Melo 
Signed-off-by: Leandro Melo de Sales 
Signed-off-by: Ian McDonald 
Signed-off-by: David S. Miller