non-TLS socket accepted is blocking by default

[veeg]

The documentation for nopoll_conn_get_msg() states that the accepted socket will be non-blocking by default. This is not the case when the accepted socket has not enabled TLS.

The following line in the internal accept method states it will set non-blocking, and then it sets blocking.

nopoll/src/nopoll_conn.c

Lines 4692 to 4693 in e80b74a

	/* configure non blocking mode */
	nopoll_conn_set_sock_block (session, nopoll_true);

This is not the case for TLS sockets, as evident by this line:

nopoll/src/nopoll_conn.c

Lines 4874 to 4877 in e80b74a

	/* don't complete here the operation but flag it as
	* pending */
	conn->pending_ssl_accept = nopoll_true;
	nopoll_conn_set_sock_block (conn->session, nopoll_false);

Documentation for nopoll_conn_get_msg() states that default is non-blocking

nopoll/src/nopoll_conn.c

Lines 3034 to 3036 in e80b74a

	* This function is design to not block the caller. However,
	* connection socket must be in non-blocking configuration. If you
	* have not configured anything, this is the default.

This confusing behavior has tripped up multiple co-workers of mine, including me for a time, until I fully comprehended both the websocket standard and the nopoll implementation

[xhsjdm]

I've gotten the same problem while non-TLS.
Could I simply move
"nopoll_conn_set_sock_block (conn->session, nopoll_false);"
from
"
/* don't complete here the operation but flag it as
* pending /
conn->pending_ssl_accept = nopoll_true;
nopoll_conn_set_sock_block (conn->session, nopoll_false);
"
out of
"
if (listener->tls_on || tls_on) {
/ reached this point, ensure tls is enabled on this
* session */
conn->tls_on = nopoll_true;
...
nopoll_log (ctx, NOPOLL_LEVEL_DEBUG, "Prepared TLS session to be activated on next reads (conn id %d)", conn->id);

} /* end if */

"
.

I tried and test simply, it works.

[samisallinen]

This issue leaves a server using libnopoll victim for a super-easy denial-of-service attack: just telnet to the non-tls port of the server and send one character (e.g. press ctrl-c) . The nopoll thread will be waiting forever to receive a full line of text, blocking traffic on all other connections. The fix suggested above seems to work.