Basically tcp final handshake looks like this:
(C - client, S - server)
ACK[C] - FIN/ACK[S] - FIN/ACK[S] - ACK [C]
However there are servers, that didn't close connection like this,
while it is still _considered_ as valid, and using libevent http layer
we can do requests to such servers.
Modified handshake:
(C - client, S - server)
ACK[C] - RST/ACK[S] - RST/ACK[S]
And in this case we can't extract IP address from socket, because it is
already closed, and getpeername() will return: "transport endpoint is not connected".
So we need to store address that we are connecting to, after we know it,
and that is what this patch do.
I have reproduced it, however it have some extra packages.
(I will try to fix it)
https://github.com/azat/nfq-examples/blob/master/nfqnl_rst_fin.c
There was actually a bug in the original version of this: it tried to
run the finalizers after (potentially) setting current_base to NULL;
but those finalizers could themselves (potentially) be invoking stuff
that needed to know about the current event_base. So the right time to
do it is _before_ clearing current_base.
It is useful to know why you callback called with NULL (i.e. it failed),
for example if you set max_body with evhttp_connection_set_max_body_size()
you must know that it failed because of body was longer than this size.
(Commit message tweaked by Nick)
Here is the brief description of problem:
When you are use evdns to resolve domains to IP adresses (see
./sample/dns-example) you loop never returns from event_base_dispatch(),
and because of this the program will never terminated.
Because existing programs may be depending on the old behavior, we
only apply the fix when evdns_base_new() is created with a new flag -
EVDNS_BASE_DISABLE_WHEN_INACTIVE.
(Commit message edited by Nick while squashing the branch.)
This is needed to be able to read the response code line especially
when acting as an http client using evhttp_make_request.
(patched by nickm to make the return value const)
This header adds TAILQ_HEAD and TAILQ_ENTRY if sys/queue is not included.
There is a similar macro that adds LIST_ENTRY but not LIST_HEAD, even though
LIST_HEAD is used later.
This change pulls in the correct definition (swiped from sys/queue) for
LIST_HEAD and cleans up the one spot where it is used. The change can be
tested by adding
#undef LIST_HEAD
#undef LIST_ENTRY
right before the #ifndef checks and removing
#define EVENT_DEFINED_LISTENTRY_
#define EVENT_DEFINED_LISTHEAD_
so that the macros persist later.
* Fix whitespace
* Explain return value from callback function
* Reinstate return value so that caller can tell whether forech
exited early.
* Rename event_base_foreach_event_() to
event_base_foreach_event_nolock_().
* Use event_base_foreach_event_cb_fn typedef in more places
* Be more dire about undefined behavior.
