[PATCH v3] cmd: net: Add the "arp" command

[Sean Anderson]

On 4/13/21 11:14 AM, lgxue at hotmail.com wrote:
> From: Joe Xue <lgxue at hotmail.com>
> 
> The command is to query and show mac address of a specific ipAddress.
> 
> Signed-off-by: Joe Xue <lgxue at hotmail.com>
> ---
> 
>   cmd/Kconfig       |  6 ++++++
>   cmd/net.c         | 37 +++++++++++++++++++++++++++++++++++++
>   doc/usage/arp.rst | 31 +++++++++++++++++++++++++++++++
>   include/net.h     |  5 +++++
>   net/arp.c         | 24 ++++++++++++++++++++++++
>   net/arp.h         |  4 ++++
>   net/net.c         |  8 ++++++++
>   7 files changed, 115 insertions(+)
>   create mode 100644 doc/usage/arp.rst

Do you have a list of changes you made since v1/v2?

--Sean

> diff --git a/cmd/Kconfig b/cmd/Kconfig
> index 9bf5e863e4..1da4cb67f6 100644
> --- a/cmd/Kconfig
> +++ b/cmd/Kconfig
> @@ -1587,6 +1587,12 @@ config CMD_PING
>   	help
>   	  Send ICMP ECHO_REQUEST to network host
>   
> +config CMD_ARP
> +	bool "arp"
> +	help
> +	  Sends ARP_REQUEST to network host and shows the result if there is arp
> +	  response.
> +
>   config CMD_CDP
>   	bool "cdp"
>   	help
> diff --git a/cmd/net.c b/cmd/net.c
> index beb2877dfd..56703e9641 100644
> --- a/cmd/net.c
> +++ b/cmd/net.c
> @@ -480,3 +480,40 @@ U_BOOT_CMD(
>   );
>   
>   #endif  /* CONFIG_CMD_LINK_LOCAL */
> +
> +#ifdef CONFIG_CMD_ARP
> +static int do_arp(struct cmd_tbl *cmdtp, int flag, int argc, char *const argv[])
> +{
> +	u8 *ethaddr = arp_query_ethaddr;
> +
> +	if (argc < 2)
> +		return CMD_RET_USAGE;
> +
> +	arp_query_ip = string_to_ip(argv[1]);
> +	if (arp_query_ip.s_addr == 0)
> +		return CMD_RET_USAGE;
> +
> +	if ((arp_query_ip.s_addr & net_netmask.s_addr) !=
> +	    (net_ip.s_addr & net_netmask.s_addr)) {
> +		printf("The host %s is not in the same network\n", argv[1]);
> +		return CMD_RET_SUCCESS;
> +	}
> +
> +	if (net_loop(ARP) < 0) {
> +		printf("arp failed; host %s is not alive\n", argv[1]);
> +		return CMD_RET_FAILURE;
> +	}
> +
> +	printf("%s\t%02x:%02x:%02x:%02x:%02x:%02x\n", argv[1], ethaddr[0],
> +	       ethaddr[1], ethaddr[2], ethaddr[3], ethaddr[4], ethaddr[5]);
> +
> +	return CMD_RET_SUCCESS;
> +}
> +
> +U_BOOT_CMD(
> +	arp,	2,	1,	do_arp,
> +	"send ARP ARP_REQUEST to network host",
> +	"ipAddress"
> +);
> +
> +#endif /* CONFIG_CMD_ARP */
> diff --git a/doc/usage/arp.rst b/doc/usage/arp.rst
> new file mode 100644
> index 0000000000..b1f08a2ae9
> --- /dev/null
> +++ b/doc/usage/arp.rst
> @@ -0,0 +1,31 @@
> +arp command
> +===========
> +
> +Synopis
> +-------
> +
> +::
> +
> +    arp ipAddress
> +
> +Description
> +-----------
> +
> +The arp command is used to send ARP_REQUEST to network host and show the result.
> +
> +ipAddress
> +    the host ip address
> +
> +Example
> +-------
> +
> +::
> +
> +    => arp 192.168.0.1
> +    Using host_ens33 device
> +    192.168.0.1 84:94:8c:5f:e1:62
> +
> +Return value
> +------------
> +
> +The return value $? is 0 if the comand running was successful else 1
> diff --git a/include/net.h b/include/net.h
> index b95d6a6f60..60b4bf610e 100644
> --- a/include/net.h
> +++ b/include/net.h
> @@ -580,6 +580,11 @@ extern char *net_dns_env_var;		/* the env var to put the ip into */
>   extern struct in_addr net_ping_ip;	/* the ip address to ping */
>   #endif
>   
> +#if defined(CONFIG_CMD_ARP)
> +extern u8 arp_query_ethaddr[6];		/* the arp query result */
> +extern struct in_addr arp_query_ip; /* the ip address to arp query */
> +#endif
> +
>   #if defined(CONFIG_CMD_CDP)
>   /* when CDP completes these hold the return values */
>   extern ushort cdp_native_vlan;		/* CDP returned native VLAN */
> diff --git a/net/arp.c b/net/arp.c
> index 1d06ed2572..83c24072d7 100644
> --- a/net/arp.c
> +++ b/net/arp.c
> @@ -220,11 +220,20 @@ void arp_receive(struct ethernet_hdr *et, struct ip_udp_hdr *ip, int len)
>   			net_get_arp_handler()((uchar *)arp, 0, reply_ip_addr,
>   					      0, len);
>   
> +#ifdef CONFIG_CMD_ARP
> +			if (arp_query_ip.s_addr != 0) {
> +				arp_query_ip.s_addr = 0;
> +				net_set_state(NETLOOP_SUCCESS);
> +			} else {
> +#endif
>   			/* set the mac address in the waiting packet's header
>   			   and transmit it */
>   			memcpy(((struct ethernet_hdr *)net_tx_packet)->et_dest,
>   			       &arp->ar_sha, ARP_HLEN);
>   			net_send_packet(net_tx_packet, arp_wait_tx_packet_size);
> +#ifdef CONFIG_CMD_ARP
> +			}
> +#endif
>   
>   			/* no arp request pending now */
>   			net_arp_wait_packet_ip.s_addr = 0;
> @@ -243,3 +252,18 @@ bool arp_is_waiting(void)
>   {
>   	return !!net_arp_wait_packet_ip.s_addr;
>   }
> +
> +#ifdef CONFIG_CMD_ARP
> +u8 arp_query_ethaddr[6];
> +struct in_addr arp_query_ip;
> +
> +void arp_query(void)
> +{
> +	arp_wait_packet_ethaddr = arp_query_ethaddr;
> +	net_arp_wait_packet_ip = arp_query_ip;
> +
> +	arp_wait_timer_start = get_timer(0);
> +	printf("Using %s device\n", eth_get_name());
> +	arp_request();
> +}
> +#endif
> diff --git a/net/arp.h b/net/arp.h
> index 25b3c00d5c..f3e5cb8504 100644
> --- a/net/arp.h
> +++ b/net/arp.h
> @@ -29,4 +29,8 @@ void arp_raw_request(struct in_addr source_ip, const uchar *targetEther,
>   int arp_timeout_check(void);
>   void arp_receive(struct ethernet_hdr *et, struct ip_udp_hdr *ip, int len);
>   
> +#ifdef CONFIG_CMD_ARP
> +void arp_query(void);
> +#endif
> +
>   #endif /* __ARP_H__ */
> diff --git a/net/net.c b/net/net.c
> index b58f3062b2..21623562e8 100644
> --- a/net/net.c
> +++ b/net/net.c
> @@ -492,6 +492,11 @@ restart:
>   			rarp_request();
>   			break;
>   #endif
> +#if defined(CONFIG_CMD_ARP)
> +		case ARP:
> +			arp_query();
> +			break;
> +#endif
>   #if defined(CONFIG_CMD_PING)
>   		case PING:
>   			ping_start();
> @@ -1385,6 +1390,9 @@ common:
>   	case CDP:
>   	case DHCP:
>   	case LINKLOCAL:
> +#ifdef CONFIG_CMD_ARP
> +	case ARP:
> +#endif
>   		if (memcmp(net_ethaddr, "\0\0\0\0\0\0", 6) == 0) {
>   			int num = eth_get_dev_index();
>   
>