ospfd: Do not turn on write thread unless we have something in it

I am rarely seeing this crash:

r2: ospfd crashed. Core file found - Backtrace follows:
[New LWP 32748]
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib/aarch64-linux-gnu/libthread_db.so.1".
Core was generated by `/usr/lib/frr/ospfd'.
Program terminated with signal SIGABRT, Aborted.
2019-08-29 15:59:36,149 ERROR: assert failed at "test_ospf_sr_topo1/test_memory_leak":

Which translates to this code:

	node = listhead(ospf->oi_write_q);
	assert(node);
	oi = listgetdata(node);
	assert(oi);

So if we get into ospf_write without anything on the oi_write_q
we are stopping the program.

This is happening because in ospf_ls_upd_queue_send we are calling
ospf_write.  Imagine that we have a interface already on the on_write_q
and then ospf_write handles the packet send for all functions.  We
are not clearing the t_write thread and we are popping and causing
a crash.

Additionally modify OSPF_ISM_WRITE_ON(O) to not just blindly
turn on the t_write thread.  Only do so if we have data.

Signed-off-by: Donald Sharp <sharpd@cumulusnetworks.com>

ospfd: Remove redundant asserts

assert(oi) is impossible all listgetdata(node) directly proceeding
it already asserts here, besides a node cannot be created
with a null pointer!

If list_isempty is called directly before the listhead call
it is impossilbe that we do not have a valid pointer here.

Signed-off-by: Donald Sharp <sharpd@cumulusnetworks.com>

0 files changed, 0 insertions, 0 deletions