MINOR: connection: make conn_sock_drain() use the control layer's ->drain()

Now we don't touch the fd anymore there, instead we rely on the ->drain()
provided by the control layer. As such the function was renamed to
conn_ctrl_drain().

include/haproxy/connection.h

@@ -62,7 +62,7 @@ int conn_recv_netscaler_cip(struct connection *conn, int flag);
 int conn_ctrl_send(struct connection *conn, const void *buf, int len, int flags);
 
 /* drains any pending bytes from the socket */
-int conn_sock_drain(struct connection *conn);
+int conn_ctrl_drain(struct connection *conn);
 
 /* scoks4 proxy handshake */
 int conn_send_socks4_proxy_request(struct connection *conn);

src/connection.c

@@ -194,66 +194,24 @@ int conn_subscribe(struct connection *conn, void *xprt_ctx, int event_type, stru
 	return 0;
 }
 
-/* Drains possibly pending incoming data on the file descriptor attached to the
- * connection and update the connection's flags accordingly. This is used to
- * know whether we need to disable lingering on close. Returns non-zero if it
- * is safe to close without disabling lingering, otherwise zero. The SOCK_RD_SH
- * flag may also be updated if the incoming shutdown was reported by the drain()
- * function.
+/* Drains possibly pending incoming data on the connection and update the flags
+ * accordingly. This is used to know whether we need to disable lingering on
+ * close. Returns non-zero if it is safe to close without disabling lingering,
+ * otherwise zero. The CO_FL_SOCK_RD_SH flag may also be updated if the incoming
+ * shutdown was reported by the ->drain() function.
  */
-int conn_sock_drain(struct connection *conn)
+int conn_ctrl_drain(struct connection *conn)
 {
-	int turns = 2;
-	int len;
+	int ret = 0;
 
-	if (!conn_ctrl_ready(conn))
-		return 1;
-
-	if (conn->flags & (CO_FL_ERROR | CO_FL_SOCK_RD_SH))
-		return 1;
-
-	if (fdtab[conn->handle.fd].ev & (FD_POLL_ERR|FD_POLL_HUP))
-		goto shut;
-
-	if (!fd_recv_ready(conn->handle.fd))
-		return 0;
-
-	/* no drain function defined, use the generic one */
-
-	while (turns) {
-#ifdef MSG_TRUNC_CLEARS_INPUT
-		len = recv(conn->handle.fd, NULL, INT_MAX, MSG_DONTWAIT | MSG_NOSIGNAL | MSG_TRUNC);
-		if (len == -1 && errno == EFAULT)
-#endif
-			len = recv(conn->handle.fd, trash.area, trash.size,
-				   MSG_DONTWAIT | MSG_NOSIGNAL);
-
-		if (len == 0)
-			goto shut;
-
-		if (len < 0) {
-			if (errno == EAGAIN) {
-				/* connection not closed yet */
-				fd_cant_recv(conn->handle.fd);
-				break;
-			}
-			if (errno == EINTR)  /* oops, try again */
-				continue;
-			/* other errors indicate a dead connection, fine. */
-			goto shut;
-		}
-		/* OK we read some data, let's try again once */
-		turns--;
+	if (!conn_ctrl_ready(conn) || conn->flags & (CO_FL_ERROR | CO_FL_SOCK_RD_SH))
+		ret = 1;
+	else if (conn->ctrl->drain) {
+		ret = conn->ctrl->drain(conn);
+		if (ret)
+			conn->flags |= CO_FL_SOCK_RD_SH;
 	}
-
-	/* some data are still present, give up */
-	return 0;
-
- shut:
-	/* we're certain the connection was shut down */
-	fdtab[conn->handle.fd].linger_risk = 0;
-	conn->flags |= CO_FL_SOCK_RD_SH;
-	return 1;
+	return ret;
 }
 
 /*

src/mux_pt.c

@@ -75,7 +75,7 @@ static struct task *mux_pt_io_cb(struct task *t, void *tctx, unsigned short stat
 			ctx->cs->data_cb->wake(ctx->cs);
 		return NULL;
 	}
-	conn_sock_drain(ctx->conn);
+	conn_ctrl_drain(ctx->conn);
 	if (ctx->conn->flags & (CO_FL_ERROR | CO_FL_SOCK_RD_SH | CO_FL_SOCK_WR_SH))
 		mux_pt_destroy(ctx);
 	else
@@ -148,7 +148,7 @@ static int mux_pt_wake(struct connection *conn)
 		if (ret < 0)
 			return ret;
 	} else {
-		conn_sock_drain(conn);
+		conn_ctrl_drain(conn);
 		if (conn->flags & (CO_FL_ERROR | CO_FL_SOCK_RD_SH)) {
 			mux_pt_destroy(ctx);
 			return -1;
@@ -248,7 +248,7 @@ static void mux_pt_shutr(struct conn_stream *cs, enum cs_shr_mode mode)
 		cs->conn->xprt->shutr(cs->conn, cs->conn->xprt_ctx,
 		    (mode == CS_SHR_DRAIN));
 	else if (mode == CS_SHR_DRAIN)
-		conn_sock_drain(cs->conn);
+		conn_ctrl_drain(cs->conn);
 	if (cs->flags & CS_FL_SHW)
 		conn_full_close(cs->conn);
 }

src/ssl_sock.c

@@ -5276,7 +5276,7 @@ static int ssl_sock_handshake(struct connection *conn, unsigned int flag)
 				 * TCP sockets. We first try to drain possibly pending
 				 * data to avoid this as much as possible.
 				 */
-				conn_sock_drain(conn);
+				conn_ctrl_drain(conn);
 				if (!conn->err_code)
 					conn->err_code = (ctx->xprt_st & SSL_SOCK_RECV_HEARTBEAT) ?
 						CO_ER_SSL_KILLED_HB : CO_ER_SSL_HANDSHAKE;
@@ -5360,7 +5360,7 @@ static int ssl_sock_handshake(struct connection *conn, unsigned int flag)
 			 * TCP sockets. We first try to drain possibly pending
 			 * data to avoid this as much as possible.
 			 */
-			conn_sock_drain(conn);
+			conn_ctrl_drain(conn);
 			if (!conn->err_code)
 				conn->err_code = (ctx->xprt_st & SSL_SOCK_RECV_HEARTBEAT) ?
 					CO_ER_SSL_KILLED_HB : CO_ER_SSL_HANDSHAKE;

src/tcp_act.c

@@ -176,7 +176,7 @@ static enum act_return tcp_exec_action_silent_drop(struct act_rule *rule, struct
 
 #ifdef TCP_QUICKACK
 	/* drain is needed only to send the quick ACK */
-	conn_sock_drain(conn);
+	conn_ctrl_drain(conn);
 
 	/* re-enable quickack if it was disabled to ack all data and avoid
 	 * retransmits from the client that might trigger a real reset.