linux-toradex.git/net/bridge/br_stp.c, branch v3.10.10

bridge: avoid OOPS if root port not found

2013-04-30T19:51:08+00:00

Bridge can crash while trying to send topology change packet.
This happens if root port can't be found. This was reported by user
but currently unable to reproduce it easily. The STP conditions that cause
this are not known yet, but the problem doesn't have to be fatal.

Signed-off-by: Stephen Hemminger 
Signed-off-by: David S. Miller

bridge: add root port blocking

2012-11-15T01:20:44+00:00

This is Linux bridge implementation of root port guard.
If BPDU is received from a leaf (edge) port, it should not
be elected as root port.

Why would you want to do this?
If using STP on a bridge and the downstream bridges are not fully
trusted; this prevents a hostile guest for rerouting traffic.

Why not just use netfilter?
Netfilter does not track of follow spanning tree decisions.
It would be difficult and error prone to try and mirror STP
resolution in netfilter module.

Signed-off-by: Stephen Hemminger 
Signed-off-by: David S. Miller

net: cleanup unsigned to unsigned int

2012-04-15T16:44:40+00:00

Use of "unsigned int" is preferred to bare "unsigned" in net tree.

Signed-off-by: Eric Dumazet 
Signed-off-by: David S. Miller

bridge: br_log_state() s/entering/entered/

2012-03-08T08:25:25+00:00

When br_log_state() is reporting state it should say "entered"
istead of "entering" since state at this point is already
changed.

Signed-off-by: Paulius Zaleckas 
Signed-off-by: David S. Miller

bridge: message age needs to increase, not decrease.

2012-03-05T02:57:40+00:00

commit bridge: send proper message_age in config BPDU
added this gem:
  bpdu.message_age = (jiffies - root->designated_age)
  p->designated_age = jiffies + bpdu->message_age;
Notice how bpdu->message_age is negated when reassigned to
bpdu.message_age. This causes message age to decrease breaking the
STP protocol.

Signed-off-by: Joakim Tjernlund 
Signed-off-by: David S. Miller

bridge: Adjust min age inc for HZ > 256

2012-03-05T02:57:39+00:00

min age increment needs to round up its min age tick for all
HZ values to guarantee message age is increasing.

Signed-off-by: Joakim Tjernlund 
Signed-off-by: David S. Miller

bridge: master device stuck in no-carrier state forever when in user-stp mode

2011-12-01T19:05:17+00:00

When in user-stp mode, bridge master do not follow state of its slaves, so
after the following sequence of events it can stuck forever in no-carrier
state:
1) turn stp off
2) put all slaves down - master device will follow their state and also go in
no-carrier state
3) turn stp on with bridge-stp script returning 0 (go to the user-stp mode)
Now bridge master won't follow slaves' state and will never reach running
state.

This patch solves the problem by making user-stp and kernel-stp behavior
similar regarding master following slaves' states.

Signed-off-by: Vitalii Demianets 
Acked-by: Stephen Hemminger 
Signed-off-by: David S. Miller

bridge: minor cleanups

2011-07-23T00:01:13+00:00

Some minor cleanups that won't impact code:
  1. Remove inline from non-critical functions; compiler will most
     likely inline them anyway.
  2. Make function args const where possible.
  3. Whitespace cleanup

Signed-off-by: Stephen Hemminger 
Signed-off-by: David S. Miller

bridge: add notification over netlink when STP changes state

2011-07-23T00:01:12+00:00

When STP changes state of interface need to send a new link
message to reflect that change.

Signed-off-by: Stephen Hemminger 
Signed-off-by: David S. Miller

bridge: send proper message_age in config BPDU

2011-07-23T00:01:12+00:00

A bridge topology with three systems:

      +------+  +------+
      | A(2) |--| B(1) |
      +------+  +------+
           \    /
          +------+
          | C(3) |
          +------+

What is supposed to happen:
 * bridge with the lowest ID is elected root (for example: B)
 * C detects that A->C is higher cost path and puts in blocking state

What happens. Bridge with lowest id (B) is elected correctly as
root and things start out fine initially. But then config BPDU
doesn't get transmitted from A -> C. Because of that
the link from A-C is transistioned to the forwarding state.

The root cause of this is that the configuration messages
is generated with bogus message age, and dropped before
sending.

In the standardmessage_age is supposed to be:
  the time since the generation of the Configuration BPDU by
  the Root that instigated the generation of this Configuration BPDU.

Reimplement this by recording the timestamp (age + jiffies) when
recording config information. The old code incorrectly used the time
elapsed on the ageing timer which was incorrect.

See also:
  https://bugzilla.vyatta.com/show_bug.cgi?id=7164

Signed-off-by: Stephen Hemminger 
Signed-off-by: David S. Miller