[asterisk-dev] externaddr in chan_sip.c - locking required?

[Ian Pilcher]

This is a follow-up to my "STUN support idea" thread.

I have reached the point in my effort of actually updating the value of
externaddr when a AST_EVENT_NETWORK_CHANGE event occurs, so I'm trying
to understand how this variable is (or is not) accessed by multiple
threads.

Here's what I've been able to determine:

* externaddr is set in reload_config().

* externaddr is read in sip_show_settings().

* externaddr is both read and written in ast_sip_ouraddrfor().

None of these access use any locking, which seems wrong to me --
assuming that ast_sip_ouraddrfor() is supposed to be thread-safe.

Is my analysis correct?  If so, I would propose to protect accesses to
externaddr with a read/write lock, since changes should be infrequent.

Please let me know.

Thanks!

-- 
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Ian Pilcher                                         arequipeno at gmail.com
"If you're going to shift my paradigm ... at least buy me dinner first."
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