[PATCH 2/3] net: lwip: add sntp command

Jerome Forissier jerome.forissier at linaro.org
Tue Jun 3 15:49:05 CEST 2025


Hi Heinrich,

On 6/2/25 23:23, Heinrich Schuchardt wrote:
> Am 21. Mai 2025 17:14:42 MESZ schrieb Jerome Forissier <jerome.forissier at linaro.org>:
>> Implement the sntp command when NET_LWIP=y.
>>
>> Signed-off-by: Jerome Forissier <jerome.forissier at linaro.org>
>> ---
>>
>> cmd/Kconfig                |  13 ++--
>> cmd/net-lwip.c             |   5 ++
>> include/net-common.h       |  11 ++++
>> lib/lwip/Makefile          |   1 +
>> lib/lwip/u-boot/arch/cc.h  |   4 ++
>> lib/lwip/u-boot/lwipopts.h |   4 ++
>> net/lwip/Makefile          |   1 +
>> net/lwip/sntp.c            | 128 +++++++++++++++++++++++++++++++++++++
>> 8 files changed, 161 insertions(+), 6 deletions(-)
>> create mode 100644 net/lwip/sntp.c
>>
>> diff --git a/cmd/Kconfig b/cmd/Kconfig
>> index f21d27cb27f..58f629e1c34 100644
>> --- a/cmd/Kconfig
>> +++ b/cmd/Kconfig
>> @@ -2061,12 +2061,6 @@ config CMD_CDP
>> 	  and to retrieve configuration data including the VLAN id using the
>> 	  proprietary Cisco Discovery Protocol (CDP).
>>
>> -config CMD_SNTP
>> -	bool "sntp"
>> -	select PROT_UDP
>> -	help
>> -	  Synchronize RTC via network
>> -
>> config CMD_LINK_LOCAL
>> 	bool "linklocal"
>> 	depends on (LIB_RAND || LIB_HW_RAND)
>> @@ -2144,6 +2138,13 @@ config CMD_PING
>> 	help
>> 	  Send ICMP ECHO_REQUEST to network host
>>
>> +config CMD_SNTP
> 
> The command should depend on RTC support.
> 
>> +	bool "sntp"
>> +	select PROT_UDP if NET
>> +	select PROT_UDP_LWIP if NET_LWIP
>> +	help
>> +	  Synchronize RTC via network
>> +
>> config CMD_TFTPBOOT
>> 	bool "tftp"
>> 	select PROT_UDP_LWIP if NET_LWIP
>> diff --git a/cmd/net-lwip.c b/cmd/net-lwip.c
>> index cecf8d02555..2ffee64f97e 100644
>> --- a/cmd/net-lwip.c
>> +++ b/cmd/net-lwip.c
> 
> Please, put every command into a separate file instead of duplicating the #ifdef chaos of the old network stack.

While I agree that cmd/net.c is painful re. #ifdef's, I believe
cmd/net-lwip.c is not bad at all. In fact I took care of having only the
command wrappers in there (U_BOOT_CMD(...)), so it's just 55 lines at
the moment. The implementations are in
net/lwip/{dhcp,dns,ping,sntp,tftp,wget}.c. So I don't think there is
a need to change that. Or I could move the U_BOOT_CMD(...) into
net/lwip/*.c as well, leaving only the non-net commands under cmd/ (apart
from the legacy NET stuff).

Any opinions on that?


> 
>> @@ -21,6 +21,11 @@ U_BOOT_CMD(tftpboot, 3, 0, do_tftpb,
>> 	   "[loadAddress] [[hostIPaddr:]bootfilename]");
>> #endif
>>
>> +#if defined(CONFIG_CMD_SNTP)
>> +U_BOOT_CMD(sntp, 2, 1, do_sntp, "synchronize RTC via network",
>> +	   "[NTP server IP]");
>> +#endif
> 
> Why wouldn't we support server names ( e.g.  0.de.pool.ntp.org) here if we have DNS enabled?

Good idea. I will add support for server names to v2.

> 
> Please, add the missing documentation change for the commands.

Sure.

> Best regards
> 
> Heinrich
> 
> 
>> +
>> #if defined(CONFIG_CMD_DNS)
>> U_BOOT_CMD(dns, 3, 1, do_dns, "lookup the IP of a hostname",
>> 	   "hostname [envvar]");
>> diff --git a/include/net-common.h b/include/net-common.h
>> index a021bf503ff..b06cafb497e 100644
>> --- a/include/net-common.h
>> +++ b/include/net-common.h
>> @@ -505,6 +505,17 @@ int dhcp_run(ulong addr, const char *fname, bool autoload);
>>  */
>> int do_ping(struct cmd_tbl *cmdtp, int flag, int argc, char *const argv[]);
>>
>> +/**
>> + * do_sntp - Run the sntp command
>> + *
>> + * @cmdtp: Unused
>> + * @flag: Command flags (CMD_FLAG_...)
>> + * @argc: Number of arguments
>> + * @argv: List of arguments
>> + * Return: result (see enum command_ret_t)
>> + */
>> +int do_sntp(struct cmd_tbl *cmdtp, int flag, int argc, char *const argv[]);
>> +
>> /**
>>  * do_tftpb - Run the tftpboot command
>>  *
>> diff --git a/lib/lwip/Makefile b/lib/lwip/Makefile
>> index e9e8caee93a..c3f0e916f66 100644
>> --- a/lib/lwip/Makefile
>> +++ b/lib/lwip/Makefile
>> @@ -13,6 +13,7 @@ obj-y += \
>> 	lwip/src/api/sockets.o \
>> 	lwip/src/api/tcpip.o \
>> 	lwip/src/apps/http/http_client.o \
>> +	lwip/src/apps/sntp/sntp.o \
>> 	lwip/src/apps/tftp/tftp.o \
>> 	lwip/src/core/altcp_alloc.o \
>> 	lwip/src/core/altcp.o \
>> diff --git a/lib/lwip/u-boot/arch/cc.h b/lib/lwip/u-boot/arch/cc.h
>> index 6104c296f6f..f91127ac565 100644
>> --- a/lib/lwip/u-boot/arch/cc.h
>> +++ b/lib/lwip/u-boot/arch/cc.h
>> @@ -43,4 +43,8 @@
>> #define BYTE_ORDER BIG_ENDIAN
>> #endif
>>
>> +#define SNTP_STARTUP_DELAY 0
>> +void sntp_set_system_time(uint32_t sec);
>> +#define SNTP_SET_SYSTEM_TIME(sec) sntp_set_system_time(sec)
>> +
>> #endif /* LWIP_ARCH_CC_H */
>> diff --git a/lib/lwip/u-boot/lwipopts.h b/lib/lwip/u-boot/lwipopts.h
>> index edac74ff7a2..14ba7bd7ae2 100644
>> --- a/lib/lwip/u-boot/lwipopts.h
>> +++ b/lib/lwip/u-boot/lwipopts.h
>> @@ -162,4 +162,8 @@
>> #define LWIP_ALTCP_TLS_MBEDTLS          1
>> #endif
>>
>> +#if defined(CONFIG_CMD_SNTP)
>> +#define LWIP_DHCP_GET_NTP_SRV 1
>> +#endif
>> +
>> #endif /* LWIP_UBOOT_LWIPOPTS_H */
>> diff --git a/net/lwip/Makefile b/net/lwip/Makefile
>> index 5df222589b8..5bb98dc4d98 100644
>> --- a/net/lwip/Makefile
>> +++ b/net/lwip/Makefile
>> @@ -4,6 +4,7 @@ obj-$(CONFIG_$(PHASE_)DM_ETH) += net-lwip.o
>> obj-$(CONFIG_CMD_DHCP) += dhcp.o
>> obj-$(CONFIG_CMD_DNS) += dns.o
>> obj-$(CONFIG_CMD_PING) += ping.o
>> +obj-$(CONFIG_CMD_SNTP) += sntp.o
>> obj-$(CONFIG_CMD_TFTPBOOT) += tftp.o
>> obj-$(CONFIG_WGET) += wget.o
>>
>> diff --git a/net/lwip/sntp.c b/net/lwip/sntp.c
>> new file mode 100644
>> index 00000000000..3b2bc3c679d
>> --- /dev/null
>> +++ b/net/lwip/sntp.c
>> @@ -0,0 +1,128 @@
>> +// SPDX-License-Identifier: GPL-2.0+
>> +/* Copyright (C) 2025 Linaro Ltd. */
>> +
>> +#include <command.h>
>> +#include <console.h>
>> +#include <dm/device.h>
>> +#include <lwip/apps/sntp.h>
>> +#include <lwip/timeouts.h>
>> +#include <net.h>
>> +
>> +#define SNTP_TIMEOUT 10000
>> +
>> +static enum done_state {
>> +	NOT_DONE = 0,
>> +	SUCCESS,
>> +	ABORTED,
>> +	TIMED_OUT
>> +} sntp_state;
>> +
>> +static void no_response(void *arg)
>> +{
>> +	sntp_state = TIMED_OUT;
>> +}
>> +
>> +/* Called by lwIP via the SNTP_SET_SYSTEM_TIME() macro */
>> +void sntp_set_system_time(uint32_t seconds)
>> +{
>> +	char *toff;
>> +	int net_ntp_time_offset = 0;
>> +
>> +	toff = env_get("timeoffset");
>> +	if (toff)
>> +		net_ntp_time_offset = simple_strtol(toff, NULL, 10);
>> +
>> +	net_sntp_set_rtc(seconds + net_ntp_time_offset);
>> +	sntp_state = SUCCESS;
>> +}
>> +
>> +static bool ntp_server_known(void)
>> +{
>> +	int i;
>> +
>> +	for (i = 0; i < SNTP_MAX_SERVERS; i++) {
>> +		const ip_addr_t *ip = sntp_getserver(i);
>> +
>> +		if (ip && ip->addr)
>> +			return true;
>> +	}
>> +
>> +	return false;
>> +}
>> +
>> +static int sntp_loop(struct udevice *udev, ip_addr_t *srvip)
>> +{
>> +	struct netif *netif;
>> +
>> +	netif = net_lwip_new_netif(udev);
>> +	if (!netif)
>> +		return -1;
>> +
>> +	sntp_state = NOT_DONE;
>> +
>> +	sntp_setoperatingmode(SNTP_OPMODE_POLL);
>> +	sntp_servermode_dhcp(CONFIG_IS_ENABLED(CMD_DHCP));
>> +	if (srvip) {
>> +		sntp_setserver(0, srvip);
>> +	} else {
>> +		if (!ntp_server_known()) {
>> +			log_err("error: ntpserverip not set\n");
>> +			return -1;
>> +		}
>> +	}
>> +	sntp_init();
>> +
>> +	sys_timeout(SNTP_TIMEOUT, no_response, NULL);
>> +	while (sntp_state == NOT_DONE) {
>> +		net_lwip_rx(udev, netif);
>> +		sys_check_timeouts();
>> +		if (ctrlc()) {
>> +			printf("\nAbort\n");
>> +			sntp_state = ABORTED;
>> +			break;
>> +		}
>> +	}
>> +	sys_untimeout(no_response, NULL);
>> +
>> +	sntp_stop();
>> +	net_lwip_remove_netif(netif);
>> +
>> +	if (sntp_state == SUCCESS)
>> +		return 0;
>> +
>> +	return -1;
>> +}
>> +
>> +int do_sntp(struct cmd_tbl *cmdtp, int flag, int argc, char *const argv[])
>> +{
>> +	ip_addr_t *srvip = NULL;
>> +	char *server_ip = NULL;
>> +	ip_addr_t ipaddr;
>> +
>> +	switch (argc) {
>> +	case 1:
>> +		server_ip = env_get("ntpserverip");
>> +		break;
>> +	case 2:
>> +		server_ip = argv[1];
>> +		break;
>> +	default:
>> +		return CMD_RET_USAGE;
>> +	}
>> +
>> +	if (server_ip) {
>> +		if (!ipaddr_aton(server_ip, &ipaddr)) {
>> +			log_err("error: ipaddr_aton\n");
>> +			return CMD_RET_FAILURE;
>> +		}
>> +		srvip = &ipaddr;
>> +	}
>> +
>> +	if (net_lwip_eth_start() < 0)
>> +		return CMD_RET_FAILURE;
>> +
>> +	if (sntp_loop(eth_get_dev(), srvip) < 0)
>> +		return CMD_RET_FAILURE;
>> +
>> +	return CMD_RET_SUCCESS;
>> +}
> 


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