http.c evhttp_make_request can`t send message by vrf network about libevent HOT 9 CLOSED

Please try upstream/master.

from libevent.

You should not play with fd, especially on non upstream, since it does not includes #795

But I guess you can try to use evhttp_connection_base_bufferevent_new, and pass bufferevent with fd that you configured.

from libevent.

You should not play with fd, especially on non upstream, since it does not includes #795

But I guess you can try to use evhttp_connection_base_bufferevent_new, and pass bufferevent with fd that you configured.

I tried this, but it didn't work. So I found this when I searched again for why it didn't work.

evhttp_make_request(struct evhttp_connection *evcon,
    struct evhttp_request *req,
    enum evhttp_cmd_type type, const char *uri)
{
	......
	/* If the connection object is not connected; make it so */
	if (!evhttp_connected(evcon)) {
		int res = evhttp_connection_connect_(evcon);
		/* evhttp_connection_fail_(), which is called through
		 * evhttp_connection_connect_(), assumes that req lies in
		 * evcon->requests.  Thus, enqueue the request in advance and
		 * remove it in the error case. */
		if (res != 0)
......

In evhttp_make_request, the evhttp_connection I passed in must be a link that is not transmitting data, so when this function executes to if (!evhttp_connected(evcon)), I go into it.

int
evhttp_connection_connect_(struct evhttp_connection *evcon)
{
	......

       // No matter whether the judgment is successful or not, the bufferevent fd in the evcon is updated.
	if (evcon->bind_address || evcon->bind_port) {
		evcon->fd = bind_socket(
			evcon->bind_address, evcon->bind_port, 0 /*reuse*/);
		if (evcon->fd == -1) {
			event_debug(("%s: failed to bind to \"%s\"",
				__func__, evcon->bind_address));
			return (-1);
		}

		if (bufferevent_setfd(evcon->bufev, evcon->fd))
			return (-1);
	} else {
		if (bufferevent_setfd(evcon->bufev, -1))
			return (-1);
	}
......

But in the next evhttp_connection_connect_(evcon), no matter what I do, it will overwrite the fd in the bufferevent I passed in the evhttp_connection_base_bufferevent_new.
So my pre-configured fd is not used in the actual connection.

from libevent.

A guess for the foregoing implementation manner is as follows: The user-defined fd may fail to meet the requirements of the EVHTTP due to insufficient parameters. but the fd can be modified by the user. Therefore, except for the FDs that are being connected, in other cases, the fd does not meet the requirements, you need to create an fd that meets the evhttp running configuration. You can find many places for configuring the FD in the evhttp_connection_connect_ .

So I would prefer to add option configurations to the fd that has not yet established a connection in a possible location, rather than letting the user customize the fd for use.

from libevent.

Which version of the sources you are referring to?

	} else {
		if (bufferevent_setfd(evcon->bufev, -1))
			return (-1);
	}

There is no such code anymore -

from libevent.

So I would prefer to add option configurations to the fd that has not yet established a connection in a possible location, rather than letting the user customize the fd for use

The problem with adding separate option for this is that there are too much possible options.
Plus if you create bufferevent by yourself it should work.

Also about your case, doesn't binding to the interface address (using evhttp_connection_set_local_address) does not work to make outgoing connection via specific interface?

from libevent.

The 2.1.12-stable version I use

from libevent.

So I would prefer to add option configurations to the fd that has not yet established a connection in a possible location, rather than letting the user customize the fd for use

The problem with adding separate option for this is that there are too much possible options. Plus if you create bufferevent by yourself it should work.

Also about your case, doesn't binding to the interface address (using evhttp_connection_set_local_address) does not work to make outgoing connection via specific interface?

Using evhttp_connection_set_local_address to bind the IP address of a specifiedinterface does not take effect. It cannot work on a specified interface.

from libevent.

The master branch solved my problem. Thanks.

from libevent.