[PATCH v5 02/20] net: introduce alternative implementation as net-lwip/

Thu Jul 25 14:57:23 CEST 2024

Prepare the introduction of the lwIP (lightweight IP) TCP/IP stack by
adding a new net/lwip/ directory and the NET_LWIP symbol. Network
support is either NO_NET, NET (legacy stack) or NET_LWIP. Subsequent
commits will introduce the lwIP code, re-work the NETDEVICE integration
and port some of the NET commands and features to lwIP.

SPL_NET cannot be enabled when NET_LWIP=y. SPL_NET pulls some symbols
that are part of NET (such as arp_init(), arp_timeout_check(),
arp_receive(), net_arp_wait_packet_ip()). lwIP support in SPL may be
added later.

Similarly, DFU_TFTP and FASTBOOT are not compatible with NET_LWIP
because of dependencies on net_loop(), tftp_timeout_ms,
tftp_timeout_count_max and other NET things. Let's add a dependency on
!NET_LWIP for now.

As for SANDBOX, NET_LWIP cannot be used either because of strong
assumptions on the network stack. Make NET_LWIP depend on !SANDBOX so
that the NET_LWIP alternative is not visible in make menuconfig when
sandbox_defconfig is used.

Signed-off-by: Jerome Forissier <jerome.forissier at linaro.org>
---
 Kconfig                    | 26 ++++++++++++++++++++++++++
 common/Kconfig             |  2 +-
 common/spl/Kconfig         |  1 +
 drivers/dfu/Kconfig        |  1 +
 drivers/fastboot/Kconfig   |  1 +
 drivers/net/Kconfig        |  1 +
 drivers/net/phy/Kconfig    |  2 +-
 drivers/usb/gadget/Kconfig |  2 +-
 net/Kconfig                | 29 +++++++++++++++--------------
 net/Makefile               |  4 ++++
 net/lwip/Kconfig           | 36 ++++++++++++++++++++++++++++++++++++
 11 files changed, 88 insertions(+), 17 deletions(-)
 create mode 100644 net/lwip/Kconfig

diff --git a/Kconfig b/Kconfig
index 82df59f176e..61bc6529617 100644
--- a/Kconfig
+++ b/Kconfig
@@ -745,6 +745,32 @@ source "dts/Kconfig"
 
 source "env/Kconfig"
 
+choice
+	prompt "Networking stack"
+	default NET
+
+config NO_NET
+	bool "No networking support"
+
+config NET
+	bool "Legacy U-Boot networking stack"
+	imply NETDEVICES
+
+config NET_LWIP
+	bool "Use lwIP for networking stack"
+	imply NETDEVICES
+	depends on !SANDBOX
+	help
+	  Include networking support based on the lwIP (lightweight IP)
+	  TCP/IP stack (https://nongnu.org/lwip). This is a replacement for
+	  the default U-Boot network stack and applications located in net/
+	  and enabled via CONFIG_NET as well as other pieces of code that
+	  depend on CONFIG_NET (such as cmd/net.c enabled via CONFIG_CMD_NET).
+	  Therefore the two symbols CONFIG_NET and CONFIG_NET_LWIP are mutually
+	  exclusive.
+
+endchoice
+
 source "net/Kconfig"
 
 source "drivers/Kconfig"
diff --git a/common/Kconfig b/common/Kconfig
index 4bb9f08977a..1daa495080a 100644
--- a/common/Kconfig
+++ b/common/Kconfig
@@ -424,7 +424,7 @@ config LOGF_FUNC_PAD
 
 config LOG_SYSLOG
 	bool "Log output to syslog server"
-	depends on NET
+	depends on NET || NET_LWIP
 	help
 	  Enables a log driver which broadcasts log records via UDP port 514
 	  to syslog servers.
diff --git a/common/spl/Kconfig b/common/spl/Kconfig
index af43b5f5d3c..2731849841a 100644
--- a/common/spl/Kconfig
+++ b/common/spl/Kconfig
@@ -1063,6 +1063,7 @@ config SPL_DM_SPI_FLASH
 
 config SPL_NET
 	bool "Support networking"
+	depends on !NET_LWIP
 	help
 	  Enable support for network devices (such as Ethernet) in SPL.
 	  This permits SPL to load U-Boot over a network link rather than
diff --git a/drivers/dfu/Kconfig b/drivers/dfu/Kconfig
index 971204758aa..d034b501360 100644
--- a/drivers/dfu/Kconfig
+++ b/drivers/dfu/Kconfig
@@ -20,6 +20,7 @@ config DFU_WRITE_ALT
 config DFU_TFTP
 	bool "DFU via TFTP"
 	depends on NETDEVICES
+	depends on !NET_LWIP
 	select UPDATE_COMMON
 	select DFU_OVER_TFTP
 	help
diff --git a/drivers/fastboot/Kconfig b/drivers/fastboot/Kconfig
index 70207573de2..1eb460f5a02 100644
--- a/drivers/fastboot/Kconfig
+++ b/drivers/fastboot/Kconfig
@@ -1,5 +1,6 @@
 menu "Fastboot support"
 	depends on CMDLINE
+	depends on !NET_LWIP
 
 config FASTBOOT
 	bool
diff --git a/drivers/net/Kconfig b/drivers/net/Kconfig
index b4ff033afa9..d332f712a7c 100644
--- a/drivers/net/Kconfig
+++ b/drivers/net/Kconfig
@@ -48,6 +48,7 @@ config DM_DSA
 	bool "Enable Driver Model for DSA switches"
 	depends on DM_MDIO
 	depends on PHY_FIXED
+	depends on !NET_LWIP
 	help
 	  Enable driver model for DSA switches
 
diff --git a/drivers/net/phy/Kconfig b/drivers/net/phy/Kconfig
index 73064b2af68..75986162914 100644
--- a/drivers/net/phy/Kconfig
+++ b/drivers/net/phy/Kconfig
@@ -11,7 +11,7 @@ config MV88E6352_SWITCH
 
 menuconfig PHYLIB
 	bool "Ethernet PHY (physical media interface) support"
-	depends on NET
+	depends on NET || NET_LWIP
 	help
 	  Enable Ethernet PHY (physical media interface) support.
 
diff --git a/drivers/usb/gadget/Kconfig b/drivers/usb/gadget/Kconfig
index 4621a6fd5e6..03fe3bca197 100644
--- a/drivers/usb/gadget/Kconfig
+++ b/drivers/usb/gadget/Kconfig
@@ -224,7 +224,7 @@ endif # USB_GADGET_DOWNLOAD
 
 config USB_ETHER
 	bool "USB Ethernet Gadget"
-	depends on NET
+	depends on NET || NET_LWIP
 	default y if ARCH_SUNXI && USB_MUSB_GADGET
 	help
 	  Creates an Ethernet network device through a USB peripheral
diff --git a/net/Kconfig b/net/Kconfig
index 5dff6336293..952690d677d 100644
--- a/net/Kconfig
+++ b/net/Kconfig
@@ -2,11 +2,6 @@
 # Network configuration
 #
 
-menuconfig NET
-	bool "Networking support"
-	default y
-	imply NETDEVICES
-
 if NET
 
 config ARP_TIMEOUT
@@ -26,15 +21,6 @@ config PROT_UDP
 	  Enable a generic udp framework that allows defining a custom
 	  handler for udp protocol.
 
-config BOOTDEV_ETH
-	bool "Enable bootdev for ethernet"
-	depends on BOOTSTD
-	default y
-	help
-	  Provide a bootdev for ethernet so that is it possible to boot
-	  an operationg system over the network, using the PXE (Preboot
-	  Execution Environment) protocol.
-
 config BOOTP_SEND_HOSTNAME
 	bool "Send hostname to DNS server"
 	help
@@ -255,6 +241,19 @@ config IPV6
 
 endif   # if NET
 
+source "net/lwip/Kconfig"
+
+if NET || NET_LWIP
+
+config BOOTDEV_ETH
+	bool "Enable bootdev for ethernet"
+	depends on BOOTSTD
+	default y
+	help
+	  Provide a bootdev for ethernet so that is it possible to boot
+	  an operating system over the network, using the PXE (Preboot
+	  Execution Environment) protocol.
+
 config SYS_RX_ETH_BUFFER
 	int "Number of receive packet buffers"
 	default 4
@@ -263,3 +262,5 @@ config SYS_RX_ETH_BUFFER
 	  controllers it is recommended to set this value to 8 or even higher,
 	  since all buffers can be full shortly after enabling the interface on
 	  high Ethernet traffic.
+
+endif   # if NET || NET_LWIP
diff --git a/net/Makefile b/net/Makefile
index 64ab7ec740a..70eec8caf0d 100644
--- a/net/Makefile
+++ b/net/Makefile
@@ -5,6 +5,8 @@
 
 #ccflags-y += -DDEBUG
 
+ifeq ($(CONFIG_NET),y)
+
 obj-$(CONFIG_NET)      += arp.o
 obj-$(CONFIG_CMD_BOOTP) += bootp.o
 obj-$(CONFIG_CMD_CDP)  += cdp.o
@@ -38,3 +40,5 @@ obj-$(CONFIG_CMD_WGET) += wget.o
 # sprintf(buf, index ? "foo%d" : "foo", index)
 # and this is intentional usage.
 CFLAGS_eth_common.o += -Wno-format-extra-args
+
+endif
diff --git a/net/lwip/Kconfig b/net/lwip/Kconfig
new file mode 100644
index 00000000000..0a6bcb41369
--- /dev/null
+++ b/net/lwip/Kconfig
@@ -0,0 +1,36 @@
+#
+# Network configuration (with lwIP stack)
+#
+
+config LWIP_DEBUG
+	bool "Enable debug traces in the lwIP library"
+
+config LWIP_ASSERT
+	bool "Enable assertions in the lwIP library"
+
+config PROT_DHCP_LWIP
+	bool "DHCP support in lwIP"
+	depends on PROT_UDP_LWIP
+	help
+	  Enable support for the DHCP protocol in lwIP.
+
+config PROT_DNS_LWIP
+	bool
+	depends on PROT_UDP_LWIP
+
+config PROT_RAW_LWIP
+	bool
+
+config PROT_TCP_LWIP
+	bool
+
+config PROT_TCP_SACK_LWIP
+	bool "TCP SACK support"
+	depends on PROT_TCP_LWIP
+	default y
+	help
+	  TCP protocol with selective acknowledgements. Improves
+	  file transfer speed in wget.
+
+config PROT_UDP_LWIP
+	bool
-- 
2.40.1

