net: pkt: support common usage of control block

Supported common usage of control block for any layer.

Signed-off-by: Yangbo Lu <[email protected]>

Author: yangbolu1991

drivers/ieee802154/Kconfig

@@ -9,6 +9,7 @@
 menuconfig IEEE802154
 	bool "IEEE 802.15.4 drivers"
 	depends on NETWORKING
+	select NET_PKT_CONTROL_BLOCK
 	default y if NET_L2_PHY_IEEE802154
 
 if IEEE802154

include/zephyr/net/ieee802154_pkt.h

@@ -25,10 +25,6 @@ extern "C" {
 
 /** @cond ignore */
 
-#ifndef NET_PKT_HAS_CONTROL_BLOCK
-#define NET_PKT_HAS_CONTROL_BLOCK
-#endif
-
 /* See section 6.16.2.8 - Received Signal Strength Indicator (RSSI) */
 #define IEEE802154_MAC_RSSI_MIN       0U   /* corresponds to -174 dBm */
 #define IEEE802154_MAC_RSSI_MAX       254U /* corresponds to 80 dBm */

include/zephyr/net/net_pkt.h

@@ -317,18 +317,18 @@ struct net_pkt {
 	uint16_t vlan_tci;
 #endif /* CONFIG_NET_VLAN */
 
-#if defined(NET_PKT_HAS_CONTROL_BLOCK)
-	/* TODO: Evolve this into a union of orthogonal
-	 *       control block declarations if further L2
-	 *       stacks require L2-specific attributes.
-	 */
+#if defined(CONFIG_NET_PKT_CONTROL_BLOCK)
+	/* Control block which could be used by any layer */
+	union {
+		uint8_t cb[CONFIG_NET_PKT_CONTROL_BLOCK_SIZE];
 #if defined(CONFIG_IEEE802154)
-	/* The following structure requires a 4-byte alignment
-	 * boundary to avoid padding.
-	 */
-	struct net_pkt_cb_ieee802154 cb;
+		/* The following structure requires a 4-byte alignment
+		 * boundary to avoid padding.
+		 */
+		struct net_pkt_cb_ieee802154 cb_ieee802154;
 #endif /* CONFIG_IEEE802154 */
-#endif /* NET_PKT_HAS_CONTROL_BLOCK */
+	} cb;
+#endif /* CONFIG_NET_PKT_CONTROL_BLOCK */
 
 	/** Network packet priority, can be left out in which case packet
 	 * is not prioritised.
@@ -1463,7 +1463,7 @@ static inline void net_pkt_set_ppp(struct net_pkt *pkt,
 }
 #endif /* CONFIG_NET_L2_PPP */
 
-#if defined(NET_PKT_HAS_CONTROL_BLOCK)
+#if defined(CONFIG_NET_PKT_CONTROL_BLOCK)
 static inline void *net_pkt_cb(struct net_pkt *pkt)
 {
 	return &pkt->cb;

subsys/net/ip/Kconfig

@@ -755,6 +755,21 @@ config NET_PKT_BUF_TX_DATA_ALLOC_ALIGN_LEN
 	  that expects 4 byte alignment for the length of the data and the start
 	  of the data that is being sent.
 
+config NET_PKT_CONTROL_BLOCK
+	bool "pkt control block"
+	help
+	  This is to enable control block which can be used by any layer.
+
+config NET_PKT_CONTROL_BLOCK_SIZE
+	int "Size of pkt control block in bytes"
+	depends on NET_PKT_CONTROL_BLOCK
+	default 1
+	help
+	  Size of pkt control block in bytes if there are no other specific control blocks
+	  enabled. If there are already specific control blocks enabled, like
+	  net_pkt_cb_ieee802154, the actual pkt control block size will be the
+	  maximum of them.
+
 config NET_HEADERS_ALWAYS_CONTIGUOUS
 	bool
 	help

subsys/net/ip/net_pkt.c

@@ -2016,7 +2016,7 @@ int net_pkt_copy(struct net_pkt *pkt_dst,
 	return 0;
 }
 
-#if defined(NET_PKT_HAS_CONTROL_BLOCK)
+#if defined(CONFIG_NET_PKT_CONTROL_BLOCK)
 static inline void clone_pkt_cb(struct net_pkt *pkt, struct net_pkt *clone_pkt)
 {
 	memcpy(net_pkt_cb(clone_pkt), net_pkt_cb(pkt), sizeof(clone_pkt->cb));