linux-toradex.git/net/tipc/msg.h, branch v3.14.3

tipc: message reassembly using fragment chain

2013-11-07T23:30:11+00:00

When the first fragment of a long data data message is received on a link, a
reassembly buffer large enough to hold the data from this and all subsequent
fragments of the message is allocated. The payload of each new fragment is
copied into this buffer upon arrival. When the last fragment is received, the
reassembled message is delivered upwards to the port/socket layer.

Not only is this an inefficient approach, but it may also cause bursts of
reassembly failures in low memory situations. since we may fail to allocate
the necessary large buffer in the first place. Furthermore, after 100 subsequent
such failures the link will be reset, something that in reality aggravates the
situation.

To remedy this problem, this patch introduces a different approach. Instead of
allocating a big reassembly buffer, we now append the arriving fragments
to a reassembly chain on the link, and deliver the whole chain up to the
socket layer once the last fragment has been received. This is safe because
the retransmission layer of a TIPC link always delivers packets in strict
uninterrupted order, to the reassembly layer as to all other upper layers.
Hence there can never be more than one fragment chain pending reassembly at
any given time in a link, and we can trust (but still verify) that the
fragments will be chained up in the correct order.

Signed-off-by: Erik Hugne 
Reviewed-by: Paul Gortmaker 
Signed-off-by: Jon Maloy 
Signed-off-by: David S. Miller

tipc: remove iovec length parameter from all sending functions

2013-10-18T17:20:42+00:00

tipc_msg_build() now copies message data from iovec to skb_buff
using memcpy_fromiovecend(), which doesn't need to be passed the
iovec length to perform the copying.

So we remove the parameter indicating iovec length in all
functions where TIPC messages are built and sent.

Signed-off-by: Ying Xue 
Reviewed-by: Paul Gortmaker 
Signed-off-by: Jon Maloy 
Signed-off-by: David S. Miller

tipc: cosmetic realignment of function arguments

2013-06-17T22:53:01+00:00

No runtime code changes here.  Just a realign of the function
arguments to start where the 1st one was, and fit as many args
as can be put in an 80 char line.

Signed-off-by: Paul Gortmaker 
Signed-off-by: David S. Miller

tipc: remove user_port instance from tipc_port structure

2013-06-17T22:53:00+00:00

After the native API has been completely removed, the 'user_port'
field in struct tipc_port becomes unused, and can be removed.
As a consequence, the "usrmem" argument in tipc_msg_build() is no
longer needed, and so we remove that one too.

Signed-off-by: Ying Xue 
Signed-off-by: Jon Maloy 
Signed-off-by: Paul Gortmaker 
Signed-off-by: David S. Miller

tipc: compress out gratuitous extra carriage returns

2012-04-30T19:53:56+00:00

Some of the comment blocks are floating in limbo between two
functions, or between blocks of code.  Delete the extra line
feeds between any comment and its associated following block
of code, to be consistent with the majority of the rest of
the kernel.  Also delete trailing newlines at EOF and fix
a couple trivial typos in existing comments.

This is a 100% cosmetic change with no runtime impact.  We get
rid of over 500 lines of non-code, and being blank line deletes,
they won't even show up as noise in git blame.

Signed-off-by: Paul Gortmaker

tipc: Remove duplicate check of message destination node

2012-02-24T22:05:14+00:00

Eliminates a check in the processing of TIPC messages arriving from
off node that ensures the message is destined for this node, since this
check duplicates an earlier check. (The check would be necessary if TIPC
needed to be able to route incoming messages to another node, but the
elimination of multi-cluster support means that this never happens and
all incoming messages are consumed by the receiving node.)

Note: This change involves the elimination of a single "if" statement
with a large "then" clause; consequently, a significant number of lines
end up getting re-indented. In addition, a simple message header access
routine that is no longer referenced is eliminated. However, the only
functional change is the elimination of the single check described above.

Signed-off-by: Allan Stephens 
Signed-off-by: Paul Gortmaker

tipc: Introduce node signature field in neighbor discovery message

2012-02-24T22:05:13+00:00

Adds support for the new "node signature" in neighbor discovery messages,
which is a 16 bit identifier chosen randomly when TIPC is initialized.
This field makes it possible for nodes receiving a neighbor discovery
message to detect if multiple neighboring nodes are using the same network
address (i.e. ), even when the messages are arriving on different
interfaces.

This first phase of node signature support creates the signature,
incorporates it into outgoing neighbor discovery messages, and tracks
the signature used by valid neighbors. An upcoming patch builds on this
foundation to implement the improved duplicate neighbor detection checking.

Signed-off-by: Allan Stephens 
Signed-off-by: Paul Gortmaker

tipc: Hide media-specific addressing details from generic bearer code

2011-12-27T16:33:36+00:00

Reworks TIPC's media address data structure and associated processing
routines to transfer all media-specific details of address conversion
to the associated TIPC media adaptation code. TIPC's generic bearer code
now only needs to know which media type an address is associated with
and whether or not it is a broadcast address, and totally ignores the
"value" field that contains the actual media-specific addressing info.

These changes eliminate the need for a number of endianness conversion
operations and will make it easier for TIPC to support new media types
in the future.

Signed-off-by: Allan Stephens 
Signed-off-by: Paul Gortmaker

tipc: Cleanup of message header size terminology

2011-06-24T20:18:17+00:00

Performs cosmetic cleanup of the symbolic names used to specify TIPC
payload message header sizes. The revised names now more accurately
reflect the payload messages in which they can appear. In addition,
several places where these payload message symbol names were being used
to create non-payload messages have been updated to use the proper
internal message symbolic name.

No functional changes are introduced by this rework.

Signed-off-by: Allan Stephens 
Signed-off-by: Paul Gortmaker

tipc: Eliminate redundant masking in message header routines

2011-06-24T20:18:15+00:00

Gets rid of unnecessary masking in two routines that set TIPC message
header fields. (The msg_set_bits() routine already takes care of
masking the new value to the correct size.)

Signed-off-by: Allan Stephens 
Signed-off-by: Paul Gortmaker