MINOR: connection: introduce conn_stream

This patch introduces a new struct conn_stream. It's the stream-side of
a multiplexed connection. A pool is created and destroyed on exit. For
now the conn_streams are not used at all.

include/proto/connection.h

@@ -31,6 +31,7 @@
 #include <proto/obj_type.h>
 
 extern struct pool_head *pool2_connection;
+extern struct pool_head *pool2_connstream;
 extern struct xprt_ops *registered_xprt[XPRT_ENTRIES];
 extern struct alpn_mux_list alpn_mux_list;
 
@@ -552,6 +553,11 @@ static inline void conn_free(struct connection *conn)
 	pool_free2(pool2_connection, conn);
 }
 
+/* Returns the conn from a cs. If cs is NULL, returns NULL */
+static inline struct connection *cs_conn(const struct conn_stream *cs)
+{
+	return cs ? cs->conn : NULL;
+}
 
 /* Retrieves the connection's source address */
 static inline void conn_get_from_addr(struct connection *conn)

include/proto/obj_type.h

@@ -119,6 +119,18 @@ static inline struct appctx *objt_appctx(enum obj_type *t)
 	return __objt_appctx(t);
 }
 
+static inline struct conn_stream *__objt_cs(enum obj_type *t)
+{
+	return (container_of(t, struct conn_stream, obj_type));
+}
+
+static inline struct conn_stream *objt_cs(enum obj_type *t)
+{
+	if (!t || *t != OBJ_TYPE_CS)
+		return NULL;
+	return __objt_cs(t);
+}
+
 static inline struct connection *__objt_conn(enum obj_type *t)
 {
 	return container_of(t, struct connection, obj_type);
@@ -152,6 +164,7 @@ static inline void *obj_base_ptr(enum obj_type *t)
 	case OBJ_TYPE_APPLET:   return __objt_applet(t);
 	case OBJ_TYPE_APPCTX:   return __objt_appctx(t);
 	case OBJ_TYPE_CONN:     return __objt_conn(t);
+	case OBJ_TYPE_CS:       return __objt_cs(t);
 	default:                return NULL;
 	}
 }

include/types/connection.h

@@ -39,6 +39,7 @@
 
 /* referenced below */
 struct connection;
+struct conn_stream;
 struct buffer;
 struct server;
 struct pipe;
@@ -51,6 +52,15 @@ union conn_handle {
 	int fd;                 /* file descriptor, for regular sockets */
 };
 
+/* conn_stream flags */
+enum {
+	CS_FL_NONE          = 0x00000000,  /* Just for initialization purposes */
+	CS_FL_DATA_RD_ENA   = 0x00000001,  /* receiving data is allowed */
+	CS_FL_DATA_WR_ENA   = 0x00000002,  /* sending data is desired */
+
+	CS_FL_ERROR         = 0x00000100,  /* a fatal error was reported */
+	CS_FL_EOS           = 0x00001000,  /* End of stream */
+};
 
 /* For each direction, we have a CO_FL_{SOCK,DATA}_<DIR>_ENA flag, which
  * indicates if read or write is desired in that direction for the respective
@@ -297,6 +307,18 @@ struct conn_src {
 #endif
 };
 
+/*
+ * This structure describes the elements of a connection relevant to a stream
+ */
+struct conn_stream {
+	enum obj_type obj_type;              /* differentiates connection from applet context */
+	struct connection *conn;             /* xprt-level connection */
+	unsigned int flags;                    /* CS_FL_* */
+	void *data;                          /* pointer to upper layer's entity (eg: stream interface) */
+	const struct data_cb *data_cb;       /* data layer callbacks. Must be set before xprt->init() */
+	void *ctx;                           /* mux-specific context */
+};
+
 /* This structure describes a connection with its methods and data.
  * A connection may be performed to proxy or server via a local or remote
  * socket, and can also be made to an internal applet. It can support

include/types/obj_type.h

@@ -40,6 +40,7 @@ enum obj_type {
 	OBJ_TYPE_APPCTX,       /* object is a struct appctx */
 	OBJ_TYPE_CONN,         /* object is a struct connection */
 	OBJ_TYPE_SRVRQ,        /* object is a struct dns_srvrq */
+	OBJ_TYPE_CS,           /* object is a struct conn_stream */
 	OBJ_TYPE_ENTRIES       /* last one : number of entries */
 } __attribute__((packed)) ;
 

src/connection.c

@@ -28,6 +28,7 @@
 #endif
 
 struct pool_head *pool2_connection;
+struct pool_head *pool2_connstream;
 struct xprt_ops *registered_xprt[XPRT_ENTRIES] = { NULL, };
 
 /* List head of all known muxes for ALPN */
@@ -39,7 +40,19 @@ struct alpn_mux_list alpn_mux_list = {
 int init_connection()
 {
 	pool2_connection = create_pool("connection", sizeof (struct connection), MEM_F_SHARED);
-	return pool2_connection != NULL;
+	if (!pool2_connection)
+		goto fail_conn;
+
+	pool2_connstream = create_pool("conn_stream", sizeof(struct conn_stream), MEM_F_SHARED);
+	if (!pool2_connstream)
+		goto fail_cs;
+
+	return 1;
+ fail_cs:
+	pool_destroy2(pool2_connection);
+	pool2_connection = NULL;
+ fail_conn:
+	return 0;
 }
 
 /* I/O callback for fd-based connections. It calls the read/write handlers

src/haproxy.c

@@ -2189,6 +2189,7 @@ void deinit(void)
 	pool_destroy2(pool2_stream);
 	pool_destroy2(pool2_session);
 	pool_destroy2(pool2_connection);
+	pool_destroy2(pool2_connstream);
 	pool_destroy2(pool2_requri);
 	pool_destroy2(pool2_task);
 	pool_destroy2(pool2_capture);