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BUG/MAJOR: stream-int: do not depend on connection flags to detect connection

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Recent fix 7bf3fa3 ("BUG/MAJOR: connection: update CO_FL_CONNECTED before
calling the data layer") marked an end to a fragile situation where the
absence of CO_FL_{CONNECTED,L4,L6}* flags is used to mark the completion
of a connection setup. The problem is that by setting the CO_FL_CONNECTED
flag earlier, we can indeed call the ->wake() function from conn_fd_handler
but the stream-interface's wake function needs to see CO_FL_CONNECTED unset
to detect that a connection has just been established, so if there's no
pending data in the buffer, the connection times out. The other ->wake()
functions (health checks and idle connections) don't do this though.

So instead of trying to detect a subtle change in connection flags,
let's simply rely on the stream-interface's state and validate that the
connection is properly established and that handshakes are completed
before reporting the WRITE_NULL indicating that a pending connection was
just completed.

This patch passed all tests of handshake and non-handshake combinations,
with synchronous and asynchronous connect() and should be safe for backport
to 1.7, 1.6 and 1.5 when the fix above is already present.
This commit is contained in:
Willy Tarreau 2017-03-18 17:11:37 +01:00
parent d78c0fa0fb
commit 52821e2737
1 changed files with 2 additions and 1 deletions
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3
src/stream_interface.c
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@ -563,7 +563,8 @@ static int si_conn_wake_cb(struct connection *conn)
if (conn->flags & CO_FL_ERROR)
si->flags |= SI_FL_ERR;
if (unlikely(!(conn->flags & (CO_FL_WAIT_L4_CONN | CO_FL_WAIT_L6_CONN | CO_FL_CONNECTED)))) {
if ((si->state < SI_ST_EST) &&
(conn->flags & (CO_FL_CONNECTED | CO_FL_HANDSHAKE)) == CO_FL_CONNECTED) {
si->exp = TICK_ETERNITY;
oc->flags |= CF_WRITE_NULL;
}