linux-toradex.git/net/tipc/discover.c, branch v3.9-rc2

tipc: remove the bearer congestion mechanism

2012-11-22T01:07:25+00:00

Currently at the TIPC bearer layer there is the following congestion
mechanism:

Once sending packets has failed via that bearer, the bearer will be
flagged as being in congested state at once. During bearer congestion,
all packets arriving at link will be queued on the link's outgoing
buffer.  When we detect that the state of bearer congestion has
relaxed (e.g. some packets are received from the bearer) we will try
our best to push all packets in the link's outgoing buffer until the
buffer is empty, or until the bearer is congested again.

However, in fact the TIPC bearer never receives any feedback from the
device layer whether a send was successful or not, so it must always
assume it was successful. Therefore, the bearer congestion mechanism
as it exists currently is of no value.

But the bearer blocking state is still useful for us. For example,
when the physical media goes down/up, we need to change the state of
the links bound to the bearer.  So the code maintaing the state
information is not removed.

Signed-off-by: Ying Xue 
Signed-off-by: Paul Gortmaker

tipc: phase out most of the struct print_buf usage

2012-07-13T23:33:28+00:00

The tipc_printf is renamed to tipc_snprintf, as the new name
describes more what the function actually does.  It is also
changed to take a buffer and length parameter and return
number of characters written to the buffer.  All callers of
this function that used to pass a print_buf are updated.

Final removal of the struct print_buf itself will be done
synchronously with the pending removal of the deprecated
logging code that also was using it.

Functions that build up a response message with a list of
ports, nametable contents etc. are changed to return the number
of characters written to the output buffer. This information
was previously hidden in a field of the print_buf struct, and
the number of chars written was fetched with a call to
tipc_printbuf_validate.  This function is removed since it
is no longer referenced nor needed.

A generic max size ULTRA_STRING_MAX_LEN is defined, named
in keeping with the existing TIPC_TLV_ULTRA_STRING, and the
various definitions in port, link and nametable code that
largely duplicated this information are removed.  This means
that amount of link statistics that can be returned is now
increased from 2k to 32k.

The buffer overflow check is now done just before the reply
message is passed over netlink or TIPC to a remote node and
the message indicating a truncated buffer is changed to a less
dramatic one (less CAPS), placed at the end of the message.

Signed-off-by: Erik Hugne 
Signed-off-by: Jon Maloy 
Signed-off-by: Paul Gortmaker

tipc: use standard printk shortcut macros (pr_err etc.)

2012-07-13T23:24:44+00:00

All messages should go directly to the kernel log.  The TIPC
specific error, warning, info and debug trace macro's are
removed and all references replaced with pr_err, pr_warn,
pr_info and pr_debug.

Commonly used sub-strings are explicitly declared as a const
char to reduce .text size.

Note that this means the debug messages (changed to pr_debug),
are now enabled through dynamic debugging, instead of a TIPC
specific Kconfig option (TIPC_DEBUG).  The latter will be
phased out completely

Signed-off-by: Erik Hugne 
Signed-off-by: Jon Maloy 
[PG: use pr_fmt as suggested by Joe Perches ]
Signed-off-by: Paul Gortmaker

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: Eliminate trivial buffer manipulation helper routines

2012-02-24T22:05:16+00:00

Gets rid of two inlined routines that simply call existing sk_buff
manipulation routines, since there is no longer any extra processing
done by the helper routines.

Note that these changes are essentially cosmetic in nature, and have
no impact on the actual operation of TIPC.

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

tipc: Detect duplicate nodes using different network interfaces

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

Utilizes the new "node signature" field in neighbor discovery messages
to ensure that all links TIPC associates with a given  network
address belong to the same neighboring node. (Previously, TIPC could not
tell if link setup requests arriving on different interfaces were from
the same node or from two different nodes that has mistakenly been assigned
the same network address.)

The revised algorithm for detecting a duplicate node considers both the
node signature and the network interface adddress specified in a request
message when deciding how to respond to a link setup request. This prevents
false alarms that might otherwise arise during normal network operation
under the following scenarios:

a) A neighboring node reboots. (The node's signature changes, but the
network interface address remains unchanged.)

b) A neighboring node's network interface is replaced. (The node's signature
remains unchanged, but the network interface address changes.)

c) A neighboring node is completely replaced. (The node's signature and
network interface address both change.)

The algorithm also handles cases in which a node reboots and re-establishes
its links to TIPC (or begins re-establishing those links) before TIPC
detects that it is using a new node signature. In such cases of "delayed
rediscovery" TIPC simply accepts the new signature without disrupting
communication that is already underway over the links.

Thanks to Laser [gotolaser@gmail.com] for his contributions to the
development of this enhancement.

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: rename struct link* to struct tipc_link*

2011-12-30T02:53:30+00:00

This converts the following:

	struct link		->	struct tipc_link
	struct link_req		->	struct tipc_link_req
	struct link_name	->	struct tipc_link_name

Signed-off-by: Paul Gortmaker

tipc: Ignore neighbor discovery messages containing invalid address

2011-12-27T16:33:38+00:00

Adds a check to ensure that TIPC ignores an incoming neighbor discovery
message that specifies an invalid media address as its source. The check
ensures that the source address is a valid, non-broadcast address that
could legally be used by a neighboring link endpoint.

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