Sync csa-v1.5-branch branch with release_2.8-1.5

config/esp32/args.gni

@@ -26,7 +26,6 @@ lwip_platform = "external"
 
 #Enabling this causes some error
 #chip_inet_config_enable_tun_endpoint = false
-chip_inet_config_enable_tcp_endpoint = false
 chip_inet_config_enable_udp_endpoint = true
 
 chip_config_memory_management = "platform"

config/esp32/components/chip/CMakeLists.txt

@@ -121,6 +121,12 @@ if(CONFIG_DISABLE_IPV4)
     endif()
 endif()
 
+if(CONFIG_ENABLE_TCP_TRANSPORT)
+    chip_gn_arg_append("chip_inet_config_enable_tcp_endpoint" "true")
+else()
+    chip_gn_arg_append("chip_inet_config_enable_tcp_endpoint" "false")
+endif()
+
 if(CONFIG_DISABLE_READ_CLIENT)
     chip_gn_arg_append("chip_enable_read_client"             "false")
 endif()

config/esp32/components/chip/Kconfig

@@ -32,7 +32,7 @@ menu "CHIP Core"
             default 8
             help
                 The maximum number of simultaneously active CHIP exchange contexts.
-                                           
+
                 An exchange context object is used to track the state of an ongoing CHIP message
                 exchange (conversation) with a peer, e.g. a cloud service, a mobile application, or
                 another device.
@@ -257,6 +257,14 @@ menu "CHIP Core"
                 Here, we are also enabling LWIP_CHECK_THREAD_SAFETY which will assert when
                 LwIP code gets called from any other context or without holding the LwIP lock.
 
+        config USE_LWIP_PBUF_RAM_PACKETBUFFER
+            bool "Use lwIP PBUF_RAM type for CHIP packet buffer"
+            default n
+            help
+                Enable this option to use lwIP PBUF_RAM type for CHIP packet buffer. Configure via
+                MAX_LARGE_BUFFER_SIZE_BYTES to support larger packets exceeding IPv6 MTU.
+                If not enabled, CHIP will use lwIP PBUF_POOL type for packet buffer.
+
     endmenu # "Networking Options"
 
     menu "System Options"
@@ -285,8 +293,8 @@ menu "CHIP Core"
             depends on ENABLE_OTA_REQUESTOR
             default n
             help
-                Enable this option for delta OTA image updates. 
-                Delta OTA updates allow for smaller, more efficient updates by only 
+                Enable this option for delta OTA image updates.
+                Delta OTA updates allow for smaller, more efficient updates by only
                 sending the changes between the current and new firmware versions.
 
         config OTA_AUTO_REBOOT_ON_APPLY
@@ -1214,6 +1222,23 @@ menu "CHIP Device Layer"
 
     endmenu
 
+    menu "Matter TCP transport options"
+        config ENABLE_TCP_TRANSPORT
+            bool "Enable TCP transport"
+            select USE_LWIP_PBUF_RAM_PACKETBUFFER
+            default n
+            help
+                Enable TCP transport. If enabled, USE_LWIP_PBUF_RAM_PACKETBUFFER must be configured.
+
+        config MAX_LARGE_BUFFER_SIZE_BYTES
+            int "Max buffer size for TCP payloads"
+            depends on ENABLE_TCP_TRANSPORT
+            default 1530
+            help
+                Max TCP payload buffer size.
+
+    endmenu
+
     menu "Network Commissioning Driver Endpoint Id"
         config THREAD_NETWORK_COMMISSIONING_DRIVER
             bool "Use the generic Thread network commissioning driver"

src/platform/ESP32/CHIPPlatformConfig.h

@@ -158,3 +158,7 @@
 #else
 #define CHIP_SYSTEM_CONFIG_POOL_USE_HEAP 0
 #endif
+
+#ifdef CONFIG_MAX_LARGE_BUFFER_SIZE_BYTES
+#define CHIP_SYSTEM_CONFIG_MAX_LARGE_BUFFER_SIZE_BYTES CONFIG_MAX_LARGE_BUFFER_SIZE_BYTES
+#endif

src/platform/ESP32/SystemPlatformConfig.h

@@ -47,3 +47,7 @@ struct ChipDeviceEvent;
 #ifndef CHIP_SYSTEM_CONFIG_NUM_TIMERS
 #define CHIP_SYSTEM_CONFIG_NUM_TIMERS CONFIG_NUM_TIMERS
 #endif // CHIP_SYSTEM_CONFIG_NUM_TIMERS
+
+#ifdef CONFIG_USE_LWIP_PBUF_RAM_PACKETBUFFER
+#define CHIP_SYSTEM_CONFIG_PACKETBUFFER_LWIP_PBUF_RAM CONFIG_USE_LWIP_PBUF_RAM_PACKETBUFFER
+#endif // CONFIG_USE_LWIP_PBUF_RAM_PACKETBUFFER

src/system/SystemPacketBuffer.cpp

@@ -589,10 +589,35 @@ PacketBufferHandle PacketBufferHandle::New(size_t aAvailableSize, uint16_t aRese
     }
 
 #if CHIP_SYSTEM_CONFIG_USE_LWIP
+#if CHIP_SYSTEM_CONFIG_PACKETBUFFER_LWIP_PBUF_RAM
+    // Allocate buffer using kMaxAllocSize instead of the requested size (lAllocSize).
+    //
+    // Rationale:
+    // 1. PBUF_RAM provides a contiguous payload buffer, ensuring consistent behavior
+    //    with PBUF_POOL (non-chained) operations regardless of actual data size.
+    // 2. The standard lwIP pbuf structure lacks a field to store the actual allocated
+    //    size. By always allocating kMaxAllocSize, AllocSize() can return a constant
+    //    value (kMaxAllocSize) without needing to track the original allocation size.
+    //
+    // kMaxAllocSize configuration:
+    // - TCP: Configurable via CHIP_SYSTEM_CONFIG_MAX_LARGE_BUFFER_SIZE_BYTES to support
+    //        larger packets exceeding IPv6 MTU. Note: This may result in unused buffer
+    //        space; configure based on the maximum packet size requirements.
+    // - UDP: Fixed to LWIP_MEM_ALIGN_SIZE(PBUF_POOL_BUFSIZE)
+    //
+    // Despite allocating kMaxAllocSize, we still keep the validation for lAllocSize
+    // to fail early if the requested size exceeds the maximum capacity.
+    //
+    // This cast is safe because kLargeBufMaxSizeWithoutReserve has been statically
+    // asserted to fit in uint16_t.
+    lPacket = static_cast<PacketBuffer *>(
+        pbuf_alloc(PBUF_RAW, static_cast<uint16_t>(PacketBuffer::kMaxAllocSize), CHIP_SYSTEM_PACKETBUFFER_LWIP_PBUF_TYPE));
+#else
     // This cast is safe because lAllocSize is no larger than
     // kMaxSizeWithoutReserve, which fits in uint16_t.
     lPacket = static_cast<PacketBuffer *>(
         pbuf_alloc(PBUF_RAW, static_cast<uint16_t>(lAllocSize), CHIP_SYSTEM_PACKETBUFFER_LWIP_PBUF_TYPE));
+#endif
 
     SYSTEM_STATS_UPDATE_LWIP_PBUF_COUNTS();
 

src/system/SystemPacketBuffer.h

@@ -178,6 +178,8 @@ class DLL_EXPORT PacketBuffer : private pbuf
             return LWIP_MEM_ALIGN_SIZE(PBUF_POOL_BUFSIZE) - kStructureSize;
         else
             return LWIP_MEM_ALIGN_SIZE(memp_sizes[this->pool]) - kStructureSize;
+#elif CHIP_SYSTEM_CONFIG_PACKETBUFFER_LWIP_PBUF_RAM
+        return PacketBuffer::kMaxAllocSize;
 #else
 #error "Unimplemented PacketBuffer storage case"
 #endif