[PATCH v5 00/20] Introduce the lwIP network stack

Jerome Forissier
2024-07-25T12:58:30Z

This is a rework of a patch series by Maxim Uvarov: "net/lwip: add lwip
library for the network stack" [1]. The goal is to introduce the lwIP TCP/IP
stack [2] [3] as an alternative to the current implementation in net/,
selectable with Kconfig, and ultimately keep only lwIP if possible. Some
reasons for doing so are:
- Make the support of HTTPS in the wget command easier. Javier T. and
Raymond M. (CC'd) have some additional lwIP and Mbed TLS patches to do
so. With that it becomes possible to fetch and launch a distro installer
such as Debian etc. using a secure, authenticated connection directly
from the U-Boot shell. Several use cases:
* Authentication: prevent MITM attack (third party replacing the
binary with a different one)
* Confidentiality: prevent third parties from grabbing a copy of the
image as it is being downloaded
* Allow connection to servers that do not support plain HTTP anymore
(this is becoming more and more common on the Internet these days)
- Possibly benefit from additional features implemented in lwIP
- Less code to maintain in U-Boot

Prior to applying this series, the lwIP stack needs to be added as a
Git subtree with the following command:

$ git subtree add --squash --prefix lib/lwip/lwip https://git.savannah.gnu.org/git/lwip.git STABLE-2_2_0_RELEASE

Notes:

1. A number of features are currently incompatible with NET_LWIP: SANDBOX,
DFU_TFTP, FASTBOOT, SPL_NET. All make assumptions on how the network
stack is implemented and/or pull sybols that are not trivially exported
from lwIP. Some interface rework may be needed.

2. Due to the above and in order to provide some level of testing, a new QEMU
configuration is introduced (qemu_arm64_lwip_defconfig) which is the same
as qemu_arm64_defconfig but with NET_LWIP and CMD_*_LWIP enabled.
Tests are added to test/py/tests/test_net.py for that configuration.

3. The default QEMU networking doesn't work with NET_LWIP. wget
pauses and resets the connection. Wireshark shows [TCP Window Full] and
[TCP ZeroWindow]. Wen using an emulated e1000 however all is fine
(that is "-nic tap,model=e1000" on the QEMU command line, with a bridge
configured on the host).

Changes in v5:

- Rebased on next
- Refactor Kconfig options to avoid duplicates
- Library functions use a more consistent naming (dhcp_loop(),
ping_loop() etc.) and take a struct udevice * parameter (Heinrich S.)
- Do not use net_process_receive_packet() for input anymore. Instead of
calling eth_rx() which would invoke net_process_receive_packet(), we
call a new net_lwip_rx(udev) function which invokes the device recv()
and pushes the packets up the lwIP stack. Thus everything is tied to
a udevice now. (Heinrich S.)
- Add "configs: replace '# CONFIG_NET is not set' with CONFIG_NO_NET=y"
(Tom R.)
- tftp: unify display with legacy command: add throughput, 65 hashes per
line, one every 10 blocks received (Tom R.)
- Moved net-lwip/* to net/lwip/* (Simon G.)
- Rename static function low_level_output() to linkoutput() since it is
the name used in the lwIP netif struct.
- Fixed off-by-one in parse_url() which could cause wget to fail when
passed a URL with a host name (as opposed to a URL with an IP address).
- Improved TFTP performance by adding support for the blksize option
(patches "lwip: tftp: add support of blksize option to client" and
"net-lwip: add TFTP_BLOCKSIZE) (Tom R.)
- Add an optional port number to the tftp command for easier testing
(syntax: tftp [[ip:[port:]]filename])
- wget: display an "unsupported URI" error if uri is not http://
(Jon H.)
- Adjusted the lwIP TCP options in lib/lwip/u-boot/lwipopts.h for
better performance, in particular TCP_WND.
- Add "net: fec_mxc_init(): do not ignore return status of fec_open()"
- Set the proper environment variables when DHCP succeeds (ipaddr%d
etc.) and read the proper ones for the given device in new_netif(),
allowing correct behavior when several adapters are available (tested
on i.MX8M Plus).
- Fix an alignment issue with outgoing packets (see the linkoutput()
function). With that the i.MX8M Plus ENET1 interface works properly.
(reported by Tim H.).
- Add review tags

Changes in v4:

- Fixed the DHCP algorithm which was missing a sys_timeout() call in
the "fine timer" callback. This should close the issue that Tom R.
reported with his Raspberry Pi 3 (it does fix it on mine).
- The DHCP exchange timeout is increased from 2 to 10 seconds
- The DHCP exchange can be interrupted with Ctrl-C.
- "net: introduce alternative implementation as net-lwip/": rework
dependencies. A few symbols have 'depends on !NET_LWIP' and in addition
'NET_LWIP depends on !SANDBOX'. Sandbox, DSA and fastboot are
unsupported, because they are deeply welded to the current stack.
- All network commands (dns, ping, tftp and wget):
* Get rid of global variables (Ilias A.)
* Use printf() rather than log_info()
- "net-lwip: add ping command": use packet count instead of
timeout, fix code style (Ilias A.)
- Add "net: split cmd/net.c into cmd/net.c and cmd/net-common.c"
extracted from the wget patch (Ilias A.).
- Add "net: split include/net.h into net{,-common,-legacy,-lwip}.h"
(Ilias A.)
- Add "flash: prefix error codes with FL_" which is required to
avoid name clashes when splitting net.h
- Reworked the initialization of the lwIP stack. One and only
one network interface (struct netif) is added for the duration
of the command that uses that interface. That's commit "net-lwip:
add DHCP support and dhcp commmand".
- Drop "test: dm: dsa, eth: disable tests when CONFIG_NET_LWIP=y",
not needed now that NET_LWIP depend on !SANDBOX.
- qemu_arm64_lwip_defconfig now enables CMD_DNS and CMD_WGET (so
that all the supported network commands are available).

Changes in v3:

- Make NET_LWIP a Kconfig choice in patch "net: introduce alternative
implementation as net-lwip/" (Tom R.)
- Drop the patch introducing lwIP as a Git subtree and document the git
command in the cover letter instead (Tom R.)
- "net-lwip: add TFTP support and tftpboot command": use the same
"Bytes transferred =" message as in the legacy implementation (Tom R.,
Maxim U.)
- Drop "test/py: net: add _lwip variants of dhcp, ping and tftpboot
tests" which is not needed anymore.
- Add missing kfree() calls in cmd/net-common.c and fix the parsing of
decimal address in net-lwip/wget.c (patch "net-lwip: add wget command")
(Maxim U.)
- "net-lwip: add ping command": drop the ICMP payload (Ilias A.). Set
the sequence number to zero when entering ping_loop().

Changes in v2:

** Address comments from Ilias A.

- "net-lwip: add wget command"
Implement the wget_with_dns() function to do most of the wget work and
call it from do_wget(). This allows to simplify patch "net-lwip: add
support for EFI_HTTP_BOOT".

- "net-lwip: import net command from cmd/net.c"
Move a few functions from cmd/net.c to a new file cmd/net-common.c
rather than duplicating then in cmd/net-lwip.c.

- "net-lwip: add support for EFI_HTTP_BOOT"
Since wget_with_dns() is now implemented in "net-lwip: add wget command",
just enable the wget command when the lwIP stack is enabled and
EFI_HTTP_BOOT is requested.

** Address comments from Tom R.

- "net-lwip: add DHCP support and dhcp commmand",
"net-lwip: add TFTP support and tftpboot command",
"net-lwip: add ping command",
"net-lwip: add dns command",
"net-lwip: add wget command"
Do not introduce new CMD_XXX_LWIP symbols and use existing CMD_XXX
instead.

- "configs: add qemu_arm64_lwip_defconfig"
Use #include <configs/qemu_arm64_defconfig>.

- "net-lwip: import lwIP library under lib/lwip"
Patch removed and replaced by the introduction of a Git subtree:
"Squashed 'lib/lwip/lwip/' content from commit 0a0452b2c3".

Note that I have not yet addressed your comments on "test: dm: dsa,
eth: disable tests when CONFIG_NET_LWIP=y"). I need some more time
for that and I think running CI on this v2 will help better understand
what is needed for v3.

** Miscellaneous improvements

- "net: introduce alternative implementation as net-lwip/":

* Make DFU_OVER_TFTP not DFU_TFTP incompatible with NET_LWIP. It seems
quite natural to supplement "depends on NET" with "&& !NET_LWIP".
* Make PROT_*_LWIP not visible by removing the Kconfig prompt.

[1] https://lore.kernel.org/all/20231127125726.3735-1-maxim.uvarov@linaro.org/
[2] https://www.nongnu.org/lwip/
[3] https://en.wikipedia.org/wiki/LwIP

CC: Javier Tia <javier.tia@linaro.org>
CC: Raymond Mao <raymond.mao@linaro.org>

Jerome Forissier (19):
flash: prefix error codes with FL_
net: introduce alternative implementation as net-lwip/
configs: replace '# CONFIG_NET is not set' with CONFIG_NO_NET=y
net: fec_mxc_init(): do not ignore return status of fec_open()
net: split include/net.h into net{,-common,-legacy,-lwip}.h
net: eth-uclass: add function eth_start_udev()
net-lwip: build lwIP
net-lwip: add DHCP support and dhcp commmand
net-lwip: add TFTP support and tftpboot command
net-lwip: add ping command
net-lwip: add dns command
net: split cmd/net.c into cmd/net.c and cmd/net-common.c
net-lwip: add wget command
cmd: bdinfo: enable -e when CONFIG_CMD_NET_LWIP=y
configs: add qemu_arm64_lwip_defconfig
lwip: tftp: add support of blksize option to client
net-lwip: add TFTP_BLOCKSIZE
CI: add qemu_arm64_lwip to the test matrix
MAINTAINERS: net-lwip: add myself as a maintainer

Jonathan Humphreys (1):
net-lwip: lwIP wget supports user defined port in the uri, so allow
it.

.azure-pipelines.yml | 7 +
Kconfig | 26 +
MAINTAINERS | 11 +
Makefile | 4 +-
board/cobra5272/flash.c | 26 +-
board/freescale/m5253demo/flash.c | 6 +-
boot/Kconfig | 3 +-
cmd/Kconfig | 84 +-
cmd/Makefile | 9 +-
cmd/bdinfo.c | 5 +-
cmd/elf.c | 2 +-
cmd/net-common.c | 109 ++
cmd/net-lwip.c | 45 +
cmd/net.c | 115 ---
common/Kconfig | 2 +-
common/board_r.c | 4 +-
common/flash.c | 44 +-
common/spl/Kconfig | 1 +
common/usb_kbd.c | 2 +-
configs/LicheePi_Zero_defconfig | 2 +-
configs/M5249EVB_defconfig | 2 +-
configs/am335x_pdu001_defconfig | 2 +-
configs/am62ax_evm_r5_defconfig | 2 +-
configs/am62px_evm_r5_defconfig | 2 +-
configs/am62x_beagleplay_r5_defconfig | 2 +-
configs/amcore_defconfig | 2 +-
configs/anbernic-rgxx3-rk3566_defconfig | 2 +-
configs/ap143_defconfig | 2 +-
configs/ap152_defconfig | 2 +-
configs/apple_m1_defconfig | 2 +-
configs/astro_mcf5373l_defconfig | 2 +-
configs/at91sam9rlek_dataflash_defconfig | 2 +-
configs/at91sam9rlek_mmc_defconfig | 2 +-
configs/at91sam9rlek_nandflash_defconfig | 2 +-
configs/bcm7260_defconfig | 2 +-
configs/bcm7445_defconfig | 2 +-
configs/bcm968380gerg_ram_defconfig | 2 +-
configs/bcmns_defconfig | 2 +-
configs/chromebook_samus_tpl_defconfig | 2 +-
configs/cortina_presidio-asic-base_defconfig | 2 +-
configs/cortina_presidio-asic-pnand_defconfig | 2 +-
configs/durian_defconfig | 2 +-
configs/e850-96_defconfig | 2 +-
configs/ea-lpc3250devkitv2_defconfig | 2 +-
configs/efi-x86_app32_defconfig | 2 +-
configs/efi-x86_app64_defconfig | 2 +-
configs/emsdp_defconfig | 2 +-
configs/evb-px5_defconfig | 2 +-
configs/generic-rk3568_defconfig | 2 +-
configs/generic-rk3588_defconfig | 2 +-
configs/hc2910_2aghd05_defconfig | 2 +-
configs/igep00x0_defconfig | 2 +-
configs/imx6q_bosch_acc_defconfig | 2 +-
configs/imx6ulz_smm_m2_defconfig | 2 +-
configs/iot_devkit_defconfig | 2 +-
configs/legoev3_defconfig | 2 +-
configs/mk808_defconfig | 2 +-
configs/mx23evk_defconfig | 2 +-
configs/mx28evk_defconfig | 2 +-
configs/mx6memcal_defconfig | 2 +-
configs/mx6ulz_14x14_evk_defconfig | 2 +-
configs/mx7ulp_com_defconfig | 2 +-
configs/mx7ulp_evk_defconfig | 2 +-
configs/mx7ulp_evk_plugin_defconfig | 2 +-
configs/netgear_cg3100d_ram_defconfig | 2 +-
configs/nsim_700_defconfig | 2 +-
configs/nsim_700be_defconfig | 2 +-
configs/nsim_hs38be_defconfig | 2 +-
configs/openpiton_riscv64_defconfig | 2 +-
configs/openpiton_riscv64_spl_defconfig | 2 +-
configs/origen_defconfig | 2 +-
configs/pe2201_defconfig | 2 +-
configs/pinecube_defconfig | 2 +-
configs/pm9261_defconfig | 2 +-
configs/qemu_arm64_lwip_defconfig | 5 +
configs/s5p4418_nanopi2_defconfig | 2 +-
configs/s5p_goni_defconfig | 2 +-
configs/s5pc210_universal_defconfig | 2 +-
configs/sama5d27_giantboard_defconfig | 2 +-
configs/sama5d29_curiosity_mmc1_defconfig | 2 +-
configs/sama5d29_curiosity_mmc_defconfig | 2 +-
.../sama5d29_curiosity_qspiflash_defconfig | 2 +-
configs/sama7g54_curiosity_mmc_defconfig | 2 +-
.../sama7g54_curiosity_nandflash_defconfig | 2 +-
.../sama7g54_curiosity_qspiflash_defconfig | 2 +-
configs/sipeed_maix_bitm_defconfig | 2 +-
configs/sipeed_maix_smode_defconfig | 2 +-
configs/stemmy_defconfig | 2 +-
configs/stm32f429-discovery_defconfig | 2 +-
configs/stm32f429-evaluation_defconfig | 2 +-
configs/stm32f469-discovery_defconfig | 2 +-
configs/stm32h743-disco_defconfig | 2 +-
configs/stm32h743-eval_defconfig | 2 +-
configs/stm32h750-art-pi_defconfig | 2 +-
configs/stm32mp25_defconfig | 2 +-
configs/stmark2_defconfig | 2 +-
configs/th1520_lpi4a_defconfig | 2 +-
configs/thunderx_88xx_defconfig | 2 +-
configs/tools-only_defconfig | 2 +-
configs/topic_miami_defconfig | 2 +-
configs/topic_miamilite_defconfig | 2 +-
configs/topic_miamiplus_defconfig | 2 +-
configs/total_compute_defconfig | 2 +-
configs/trats2_defconfig | 2 +-
configs/trats_defconfig | 2 +-
configs/xenguest_arm64_defconfig | 2 +-
configs/xenguest_arm64_virtio_defconfig | 2 +-
configs/xilinx_versal_mini_defconfig | 2 +-
configs/xilinx_versal_mini_emmc0_defconfig | 2 +-
configs/xilinx_versal_mini_emmc1_defconfig | 2 +-
configs/xilinx_versal_mini_ospi_defconfig | 2 +-
configs/xilinx_versal_mini_qspi_defconfig | 2 +-
configs/xilinx_versal_net_mini_defconfig | 2 +-
configs/xilinx_versal_net_mini_emmc_defconfig | 2 +-
configs/xilinx_versal_net_mini_ospi_defconfig | 2 +-
configs/xilinx_versal_net_mini_qspi_defconfig | 2 +-
configs/xilinx_zynqmp_mini_defconfig | 2 +-
configs/xilinx_zynqmp_mini_emmc0_defconfig | 2 +-
configs/xilinx_zynqmp_mini_emmc1_defconfig | 2 +-
configs/xilinx_zynqmp_mini_nand_defconfig | 2 +-
.../xilinx_zynqmp_mini_nand_single_defconfig | 2 +-
configs/xilinx_zynqmp_mini_qspi_defconfig | 2 +-
configs/zynq_cse_nand_defconfig | 2 +-
configs/zynq_cse_nor_defconfig | 2 +-
configs/zynq_cse_qspi_defconfig | 2 +-
drivers/dfu/Kconfig | 1 +
drivers/fastboot/Kconfig | 1 +
drivers/mtd/cfi_flash.c | 36 +-
drivers/net/Kconfig | 3 +-
drivers/net/fec_mxc.c | 3 +-
drivers/net/phy/Kconfig | 2 +-
drivers/usb/gadget/Kconfig | 2 +-
include/flash.h | 20 +-
include/net-common.h | 413 ++++++++
include/net-legacy.h | 635 ++++++++++++
include/net-lwip.h | 37 +
include/net.h | 944 +-----------------
lib/Makefile | 2 +
lib/lwip/Makefile | 55 +
lib/lwip/lwip/src/apps/tftp/tftp.c | 94 +-
.../lwip/src/include/lwip/apps/tftp_client.h | 1 +
lib/lwip/u-boot/arch/cc.h | 43 +
lib/lwip/u-boot/arch/sys_arch.h | 0
lib/lwip/u-boot/limits.h | 0
lib/lwip/u-boot/lwipopts.h | 157 +++
net/Kconfig | 49 +-
net/Makefile | 19 +-
net/eth-uclass.c | 38 +-
net/lwip/Kconfig | 34 +
net/lwip/Makefile | 8 +
net/lwip/dhcp.c | 136 +++
net/lwip/dns.c | 127 +++
net/lwip/eth_internal.h | 35 +
net/lwip/net-lwip.c | 292 ++++++
net/lwip/ping.c | 177 ++++
net/lwip/tftp.c | 276 +++++
net/lwip/wget.c | 272 +++++
157 files changed, 3311 insertions(+), 1321 deletions(-)
create mode 100644 cmd/net-common.c
create mode 100644 cmd/net-lwip.c
create mode 100644 configs/qemu_arm64_lwip_defconfig
create mode 100644 include/net-common.h
create mode 100644 include/net-legacy.h
create mode 100644 include/net-lwip.h
create mode 100644 lib/lwip/Makefile
create mode 100644 lib/lwip/u-boot/arch/cc.h
create mode 100644 lib/lwip/u-boot/arch/sys_arch.h
create mode 100644 lib/lwip/u-boot/limits.h
create mode 100644 lib/lwip/u-boot/lwipopts.h
create mode 100644 net/lwip/Kconfig
create mode 100644 net/lwip/Makefile
create mode 100644 net/lwip/dhcp.c
create mode 100644 net/lwip/dns.c
create mode 100644 net/lwip/eth_internal.h
create mode 100644 net/lwip/net-lwip.c
create mode 100644 net/lwip/ping.c
create mode 100644 net/lwip/tftp.c
create mode 100644 net/lwip/wget.c

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2.40.1