From: Willy Tarreau <w@1wt.eu>
Date: Thu, 18 Jul 2019 16:01:14 +0000 (+0200)
Subject: MEDIUM: lua: do not allocate the remote connection anymore
X-Git-Tag: v2.1-dev2~293
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=5a0b25d31c2bd003caec8e2abb1bdb03b4ba607e;p=thirdparty%2Fhaproxy.git

MEDIUM: lua: do not allocate the remote connection anymore

Lua cosockets do not need to allocate the remote connection anymore.
However this was trickier than expected because some tests were made
on this remote connection's existence to detect establishment instead
of relying on the stream interface's state (which is how it's now done).
The flag SF_ADDR_SET was set a bit too early (before assigning the
address) so this was moved to the right place. It should not have had
any impact beyond confusing debugging.

The only remaining occurrence of the remote connection knowledge now
is for getsockname() which requires to access the connection to send
the syscall, and it's unlikely that we'll need to change this before
QUIC or so.
---

diff --git a/src/hlua.c b/src/hlua.c
index 3b58dc037c..58803e2b3b 100644
--- a/src/hlua.c
+++ b/src/hlua.c
@@ -1586,7 +1586,6 @@ __LJMP static struct hlua_socket *hlua_checksocket(lua_State *L, int ud)
 static void hlua_socket_handler(struct appctx *appctx)
 {
 	struct stream_interface *si = appctx->owner;
-	struct connection *c = cs_conn(objt_cs(si_opposite(si)->end));
 
 	if (appctx->ctx.hlua_cosocket.die) {
 		si_shutw(si);
@@ -1597,18 +1596,6 @@ static void hlua_socket_handler(struct appctx *appctx)
 		stream_shutdown(si_strm(si), SF_ERR_KILLED);
 	}
 
-	/* If the connection object is not available, close all the
-	 * streams and wakeup everything waiting for.
-	 */
-	if (!c) {
-		si_shutw(si);
-		si_shutr(si);
-		si_ic(si)->flags |= CF_READ_NULL;
-		notification_wake(&appctx->ctx.hlua_cosocket.wake_on_read);
-		notification_wake(&appctx->ctx.hlua_cosocket.wake_on_write);
-		return;
-	}
-
 	/* If we cant write, wakeup the pending write signals. */
 	if (channel_output_closed(si_ic(si)))
 		notification_wake(&appctx->ctx.hlua_cosocket.wake_on_write);
@@ -1617,10 +1604,10 @@ static void hlua_socket_handler(struct appctx *appctx)
 	if (channel_input_closed(si_oc(si)))
 		notification_wake(&appctx->ctx.hlua_cosocket.wake_on_read);
 
-	/* if the connection is not estabkished, inform the stream that we want
+	/* if the connection is not established, inform the stream that we want
 	 * to be notified whenever the connection completes.
 	 */
-	if (!(c->flags & CO_FL_CONNECTED)) {
+	if (si_opposite(si)->state < SI_ST_EST) {
 		si_cant_get(si);
 		si_rx_conn_blk(si);
 		si_rx_endp_more(si);
@@ -2224,7 +2211,6 @@ __LJMP static inline int hlua_socket_info(struct lua_State *L, struct sockaddr_s
 __LJMP static int hlua_socket_getpeername(struct lua_State *L)
 {
 	struct hlua_socket *socket;
-	struct connection *conn;
 	struct xref *peer;
 	struct appctx *appctx;
 	struct stream_interface *si;
@@ -2251,20 +2237,13 @@ __LJMP static int hlua_socket_getpeername(struct lua_State *L)
 	si = appctx->owner;
 	s = si_strm(si);
 
-	conn = cs_conn(objt_cs(s->si[1].end));
-	if (!conn) {
-		xref_unlock(&socket->xref, peer);
-		lua_pushnil(L);
-		return 1;
-	}
-
-	if (!conn_get_dst(conn)) {
+	if (!s->target_addr) {
 		xref_unlock(&socket->xref, peer);
 		lua_pushnil(L);
 		return 1;
 	}
 
-	ret = MAY_LJMP(hlua_socket_info(L, conn->dst));
+	ret = MAY_LJMP(hlua_socket_info(L, s->target_addr));
 	xref_unlock(&socket->xref, peer);
 	return ret;
 }
@@ -2301,13 +2280,7 @@ static int hlua_socket_getsockname(struct lua_State *L)
 	s = si_strm(si);
 
 	conn = cs_conn(objt_cs(s->si[1].end));
-	if (!conn) {
-		xref_unlock(&socket->xref, peer);
-		lua_pushnil(L);
-		return 1;
-	}
-
-	if (!conn_get_src(conn)) {
+	if (!conn || !conn_get_src(conn)) {
 		xref_unlock(&socket->xref, peer);
 		lua_pushnil(L);
 		return 1;
@@ -2392,7 +2365,6 @@ __LJMP static int hlua_socket_connect(struct lua_State *L)
 	struct hlua_socket *socket;
 	int port = -1;
 	const char *ip;
-	struct connection *conn;
 	struct hlua *hlua;
 	struct appctx *appctx;
 	int low, high;
@@ -2436,21 +2408,6 @@ __LJMP static int hlua_socket_connect(struct lua_State *L)
 		lua_pushnil(L);
 		return 1;
 	}
-	appctx = container_of(peer, struct appctx, ctx.hlua_cosocket.xref);
-	si = appctx->owner;
-	s = si_strm(si);
-
-	/* FIXME WTA: the conn-specific code below should now be useless */
-
-	/* Initialise connection. */
-	conn = cs_conn(si_alloc_cs(&s->si[1], NULL));
-	if (!conn) {
-		xref_unlock(&socket->xref, peer);
-		WILL_LJMP(luaL_error(L, "connect: internal error"));
-	}
-
-	/* needed for the connection not to be closed */
-	conn->target = s->target;
 
 	/* Parse ip address. */
 	addr = str2sa_range(ip, NULL, &low, &high, NULL, NULL, NULL, 0);
@@ -2480,21 +2437,18 @@ __LJMP static int hlua_socket_connect(struct lua_State *L)
 		}
 	}
 
-	if (!sockaddr_alloc(&conn->dst)) {
-		xref_unlock(&socket->xref, peer);
-		WILL_LJMP(luaL_error(L, "connect: internal error"));
-	}
-
-	memcpy(conn->dst, addr, sizeof(struct sockaddr_storage));
+	appctx = container_of(peer, struct appctx, ctx.hlua_cosocket.xref);
+	si = appctx->owner;
+	s = si_strm(si);
 
 	if (!sockaddr_alloc(&s->target_addr)) {
 		xref_unlock(&socket->xref, peer);
 		WILL_LJMP(luaL_error(L, "connect: internal error"));
 	}
 	*s->target_addr = *addr;
+	s->flags |= SF_ADDR_SET;
 
 	hlua = hlua_gethlua(L);
-	appctx = __objt_appctx(s->si[0].end);
 
 	/* inform the stream that we want to be notified whenever the
 	 * connection completes.
@@ -2681,7 +2635,7 @@ __LJMP static int hlua_socket_new(lua_State *L)
 	si_set_state(&strm->si[1], SI_ST_ASS);
 
 	/* Force destination server. */
-	strm->flags |= SF_DIRECT | SF_ASSIGNED | SF_ADDR_SET | SF_BE_ASSIGNED;
+	strm->flags |= SF_DIRECT | SF_ASSIGNED | SF_BE_ASSIGNED;
 	strm->target = &socket_tcp.obj_type;
 
 	return 1;