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 <erik.hugne@ericsson.com>
Reviewed-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
When a message fragment is received in a broadcast or unicast link,
the reception code will append the fragment payload to a big reassembly
buffer through a call to the function tipc_recv_fragm(). However, after
the return of that call, the logics goes on and passes the fragment
buffer to the function tipc_net_route_msg(), which will simply drop it.
This behavior is a remnant from the now obsolete multi-cluster
functionality, and has no relevance in the current code base.
Although currently harmless, this unnecessary call would be fatal
after applying the next patch in this series, which introduces
a completely new reassembly algorithm. So we change the code to
eliminate the redundant call.
Signed-off-by: Erik Hugne <erik.hugne@ericsson.com>
Reviewed-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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 <paul.gortmaker@windriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
When sending packets, TIPC bearers use skb_clone() before writing their
hardware header. This will however NOT copy the data buffer.
So when the same packet is sent over multiple bearers (to reach multiple
nodes), the same socket buffer data will be treated by multiple
tipc_media drivers which will write their own hardware header through
dev_hard_header().
Most of the time this is not a problem, because by the time the
packet is processed by the second media, it has already been sent over
the first one. However, when the first transmission is delayed (e.g.
because of insufficient bandwidth or through a shaper), the next bearer
will overwrite the hardware header, resulting in the packet being sent:
a) with the wrong source address, when bearers of the same type,
e.g. ethernet, are involved
b) with a completely corrupt header, or even dropped, when bearers of
different types are involved.
So when the same socket buffer is to be sent multiple times, send a
pskb_copy() instead (from the second instance on), and release it
afterwards (the bearer will skb_clone() it anyway).
Signed-off-by: Gerlando Falauto <gerlando.falauto@keymile.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Some network protocols, like InfiniBand, don't have a fixed broadcast
address but one that depends on the configuration. Move the bcast_addr
to struct tipc_bearer and initialize it with the broadcast address of
the network device when the bearer is enabled.
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
After commit 3c294cb3 "tipc: remove the bearer congestion mechanism",
we try to grab the broadcast bearer lock when sending multicast
messages over the broadcast link. This will cause an oops because
the lock is never initialized. This is an old bug, but the lock
was never actually used before commit 3c294cb3, so that why it was
not visible until now. The oops will look something like:
BUG: spinlock bad magic on CPU#2, daemon/147
lock: bcast_bearer+0x48/0xffffffffffffd19a [tipc],
.magic: 00000000, .owner: <none>/-1, .owner_cpu: 0
Pid: 147, comm: daemon Not tainted 3.8.0-rc3+ #206
Call Trace:
spin_dump+0x8a/0x8f
spin_bug+0x21/0x26
do_raw_spin_lock+0x114/0x150
_raw_spin_lock_bh+0x19/0x20
tipc_bearer_blocked+0x1f/0x40 [tipc]
tipc_link_send_buf+0x82/0x280 [tipc]
? __alloc_skb+0x9f/0x2b0
tipc_bclink_send_msg+0x77/0xa0 [tipc]
tipc_multicast+0x11b/0x1b0 [tipc]
send_msg+0x225/0x530 [tipc]
sock_sendmsg+0xca/0xe0
The above can be triggered by running the multicast demo program.
Signed-off-by: Erik Hugne <erik.hugne@ericsson.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Rename the "supported" flag in bclink structure to "recv_permitted"
to better reflect what it is used for. When this flag is set for a
given node, we are permitted to receive and acknowledge broadcast
messages from that node. Convert it to a bool at the same time,
since it is not used to store any numerical values.
Signed-off-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
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 <ying.xue@windriver.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
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 <erik.hugne@ericsson.com>
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
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 <erik.hugne@ericsson.com>
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
[PG: use pr_fmt as suggested by Joe Perches <joe@perches.com>]
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Fix incorrect start markers, wrapped summary lines, missing section
breaks, incorrect separators, and some name mismatches.
Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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 <paul.gortmaker@windriver.com>
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 <allan.stephens@windriver.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Modifies broadcast link so that an incoming fragmented message is not
lost if reassembly cannot begin because there currently is no buffer
big enough to hold the entire reassembled message. The broadcast link
now ignores the first fragment completely, which causes the sending node
to retransmit the first fragment so that reassembly can be re-attempted.
Previously, the sender would have had no reason to retransmit the 1st
fragment, so we would never have a chance to re-try the allocation.
To do this cleanly without duplicaton, a new bclink_accept_pkt()
function is introduced.
Signed-off-by: Allan Stephens <allan.stephens@windriver.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Eliminates support for the broadcast tag field, which is no longer
used by broadcast link NACK messages.
Signed-off-by: Allan Stephens <allan.stephens@windriver.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Completely redesigns broadcast link ACK and NACK mechanisms to prevent
spurious retransmit requests in dual LAN networks, and to prevent the
broadcast link from stalling due to the failure of a receiving node to
acknowledge receiving a broadcast message or request its retransmission.
Note: These changes only impact the timing of when ACK and NACK messages
are sent, and not the basic broadcast link protocol itself, so inter-
operability with nodes using the "classic" algorithms is maintained.
The revised algorithms are as follows:
1) An explicit ACK message is still sent after receiving 16 in-sequence
messages, and implicit ACK information continues to be carried in other
unicast link message headers (including link state messages). However,
the timing of explicit ACKs is now based on the receiving node's absolute
network address rather than its relative network address to ensure that
the failure of another node does not delay the ACK beyond its 16 message
target.
2) A NACK message is now typically sent only when a message gap persists
for two consecutive incoming link state messages; this ensures that a
suspected gap is not confirmed until both LANs in a dual LAN network have
had an opportunity to deliver the message, thereby preventing spurious NACKs.
A NACK message can also be generated by the arrival of a single link state
message, if the deferred queue is so big that the current message gap
cannot be the result of "normal" mis-ordering due to the use of dual LANs
(or one LAN using a bonded interface). Since link state messages typically
arrive at different nodes at different times the problem of multiple nodes
issuing identical NACKs simultaneously is inherently avoided.
3) Nodes continue to "peek" at NACK messages sent by other nodes. If
another node requests retransmission of a message gap suspected (but not
yet confirmed) by the peeking node, the peeking node forgets about the
gap and does not generate a duplicate retransmit request. (If the peeking
node subsequently fails to receive the lost message, later link state
messages will cause it to rediscover and confirm the gap and send another
NACK.)
4) Message gap "equality" is now determined by the start of the gap only.
This is sufficient to deal with the most common cases of message loss,
and eliminates the need for complex end of gap computations.
5) A peeking node no longer tries to determine whether it should send a
complementary NACK, since the most common cases of message loss don't
require it to be sent. Consequently, the node no longer examines the
"broadcast tag" field of a NACK message when peeking.
Signed-off-by: Allan Stephens <allan.stephens@windriver.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Ensures that all attempts to update broadcast link statistics are done
only while holding the lock that protects the link's main data structures,
to prevent interference by simultaneous updates caused by messages
arriving on other interfaces.
Signed-off-by: Allan Stephens <allan.stephens@windriver.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Modifies broadcast link so that it increments the "received duplicate
message" count if an incoming message cannot be added to the deferred
message queue because it is already present in the queue. (The aligns
broadcast link behavior with that of TIPC's unicast links.)
Signed-off-by: Allan Stephens <allan.stephens@windriver.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Fixes a pair of problems in broadcast link message reception code
relating to the reclamation of the node lock after consuming an
in-sequence message.
1) Now retests to see if the sending node is still up after reclaiming
the node lock, and bails out if it is non-operational.
2) Now manipulates the node's deferred message queue only after
reclaiming the node lock, rather than using queue head pointer
information that was cached previously.
Signed-off-by: Allan Stephens <allan.stephens@windriver.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Ensures that any attempt to send a NACK message over TIPC's broadcast
link has exclusive access to the link's main data structures, to prevent
interference with a simultaneous attempt to send other broadcast link
traffic (such as application-generated multicast messages).
Signed-off-by: Allan Stephens <allan.stephens@windriver.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
This changes both the struct bcbearer and struct bcbearer_pair to
have the "tipc_" prefix. Runtime behaviour is unchanged.
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Make this rename so that it is consistent with the majority
of the other tipc structs and to assist in removing any
ambiguity with other similar names in other subsystems.
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Make this rename so that it is consistent with the majority
of the other tipc structs and to assist in removing any
ambiguity with other similar names in other subsystems.
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Give it a meaningful prefix, as suggested by DaveM, so that it
is consistent with things like struct tipc_bearer, and so it isn't
confused with anything else. This has no impact on the actual
runtime code behaviour.
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Migrates the buf_seqno() helper routine from broadcast link level to
unicast link level so that it can be used both types of TIPC links.
This is a cosmetic change only, and does not affect the operation of TIPC.
Signed-off-by: Allan Stephens <allan.stephens@windriver.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Adds checks to TIPC's broadcast link so that it ignores any
acknowledgement message containing a sequence number that does not
correspond to an unacknowledged message currently in the broadcast
link's transmit queue.
This change prevents the broadcast link from becoming stalled if a
newly booted node receives stale broadcast link acknowledgement
information from another node that has not yet fully synchronized
its end of the broadcast link to reflect the current state of the
new node's end.
Signed-off-by: Allan Stephens <allan.stephens@windriver.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Adds code to release any unsent broadcast messages in the broadcast link
transmit queue if TIPC loses contact with its only neighboring node.
Previously, a broadcast link that was in the congested state would hold
on to the unsent messages, even though the messages were now undeliverable.
Signed-off-by: Allan Stephens <allan.stephens@windriver.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
The two broadcast link statistics fields that are used to derive the
average length of that link's transmit queue are now updated only after
a successful attempt to send a broadcast message, since there is no need
to update these values when an unsuccessful send attempt leaves the
queue unchanged.
Signed-off-by: Allan Stephens <allan.stephens@windriver.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Adds a check to detect when an attempt is made to send a message
via the broadcast link and no neighboring nodes are currently available
to receive it. Rather than wasting effort passing the message to the
broadcast link and broadcast bearer, who will only throw it away,
TIPC now frees the message immediately and reports success (i.e. the
message has been delivered to all available destinations).
Signed-off-by: Allan Stephens <allan.stephens@windriver.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Fixes oversight that allowed broadcast link node map to be updated without
first taking the broadcast link spinlock that protects the map. As part
of this fix the node map has been incorporated into the broadcast link
structure to make the need for such protection more evident.
Signed-off-by: Allan Stephens <allan.stephens@windriver.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Creates global variables to hold the broadcast link's pseudo-bearer and
pseudo-link structures, rather than allocating them dynamically. There
is only a single instance of each structure, and changing over to static
allocation allows elimination of code to handle the cases where dynamic
allocation was unsuccessful.
The memset in the teardown code may look like they aren't used, but
the same teardown code is run when there is a non-fatal error at
init-time, so that stale data isn't present when the user fixes the
cause of the soft error.
Signed-off-by: Allan Stephens <allan.stephens@windriver.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Eliminates obsolete code that handles broadcast bearer congestion when
the broadast link sends a NACK message, since the broadcast pseudo-bearer
never becomes blocked.
Signed-off-by: Allan Stephens <allan.stephens@windriver.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Modifies TIPC's incoming broadcast packet handler to discard messages
that cannot legally be sent over the broadcast link, including:
- broadcast protocol messages that do no contain state information
- payload messages that are not named multicast messages
- any other form of message except for bundled messages, fragmented
messages, and name distribution messages.
These checks are needed to prevent TIPC from handing an unexpected
message to a routine that isn't prepared to handle it, which could
lead to incorrect processing (up to and including invalid memory
references caused by attempts to access message fields that aren't
present in the message).
Signed-off-by: Allan Stephens <allan.stephens@windriver.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Modifies TIPC's incoming broadcast packet handler so that it no longer
pre-reads information about the deferred packet queue, since the cached
value is unreliable once the associated node lock has been released.
Signed-off-by: Allan Stephens <allan.stephens@windriver.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Modifies TIPC's incoming broadcast packet handler to ensure that the
node lock associated with the sender of the packet is held whenever
node-related data structure fields are accessed. The routine is also
restructured with a single exit point, making it easier to ensure
the node lock is properly released and the incoming packet is properly
disposed of.
Signed-off-by: Allan Stephens <allan.stephens@windriver.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Eliminates code associated with the sending of unsent broadcast link
traffic when the broadcast pseudo-bearer becomes unblocked following a
temporary congestion situation. This code is non-executable because the
broadcast pseudo-bearer never becomes blocked [see tipc_bcbearer_send()].
Signed-off-by: Allan Stephens <allan.stephens@windriver.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Updates the comments in the broadcast bearer send routine to more
accurately describe the processing done by the routine. Also replaces
the improper use of a TIPC payload message error status symbol (in a place
that has nothing to do with such errors) with its numeric equivalent.
Signed-off-by: Allan Stephens <allan.stephens@windriver.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Updates TIPC's broadcast link in a couple of places that were missed
during the transition from its former name ("multicast-link") to its
current name ("broadcast-link"). These changes are essentially cosmetic
and do not affect the overall operation of TIPC.
Signed-off-by: Allan Stephens <allan.stephens@windriver.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Modifies the existing broadcast link sanity check that detects an
attempt to send a message off-node when there are no available
destinations so that it no longer causes a kernel panic; instead,
the check now issues a warning and stack trace and then returns
without sending the message anywhere.
Signed-off-by: Allan Stephens <allan.stephens@windriver.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Modifies a TIPC send routine that did not discard the outgoing sk_buff
if it was not transmitted because of link congestion; this eliminates
the potential for buffer leakage in the many callers who did not clean up
the unsent buffer. (The two routines that previously did discard the unsent
buffer have been updated to eliminate their now-redundant clean up.)
Signed-off-by: Allan Stephens <allan.stephens@windriver.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Eliminates optional code used to test TIPC's ability to recover
from lost broadcast messages. This code duplicates functionality
already provided by the network stack's QoS option "network emulator".
Signed-off-by: Allan Stephens <allan.stephens@windriver.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Enhance TIPC to skip unnecessary (and, in some cases, redundant)
preparation work when sending a broadcast link NACK message, since this
preparation is only required for broadcast messages that are sent in a
reliable manner. This change also fixes a bug that caused NACK messages
to be improperly counted as "TX packets" in TIPC's broadcast link
statistics.
Signed-off-by: Allan Stephens <Allan.Stephens@windriver.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Enhances TIPC's unicast and broadcast link code to update the transmit
queue maximum size counter in a single place, namely the routine that
adds messages to the queue. This ensures that the maximum size statistic
reported for unicast links is completely accurate, rather than being
partially based on statistical sampling.
The changes to link.h are just documenting the roles of the variables.
Signed-off-by: Allan Stephens <Allan.Stephens@windriver.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Allows the broadcast link to track the node that is requesting a retransmit
in a new field dedicated to that purpose. This replaces the existing
mechanism that (ab)uses an existing node structure linked list field to do
the tracking.
Signed-off-by: Allan Stephens <Allan.Stephens@windriver.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Combines two distinct structures containing information about a TIPC bearer
into a single structure. The structures were previously kept separate so
that public information about a bearer could be made available to plug-in
media types using TIPC's native API, while the remaining information was
kept private for use by TIPC itself. However, now that the native API has
been removed there is no longer any need for this arrangement.
Since one of the structures was already embedded within the other, the
change largely involves replacing instances of "publ.foo" with "foo".
The changes do not otherwise alter the operation of TIPC bearers.
Signed-off-by: Allan Stephens <Allan.Stephens@windriver.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Cleans up TIPC's source code to eliminate the presence of unnecessary
use of {} around single statements.
These changes are purely cosmetic and do not alter the operation of TIPC
in any way.
Signed-off-by: Allan Stephens <Allan.Stephens@windriver.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Cleans up TIPC's source code to eliminate the needless initialization
of static variables to zero.
These changes are purely cosmetic and do not alter the operation of TIPC
in any way.
Signed-off-by: Allan Stephens <Allan.Stephens@windriver.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
