[PATCH v2] cmd: net: Add the "arp" command
Heinrich Schuchardt
xypron.glpk at gmx.de
Sat Apr 10 02:18:19 CEST 2021
On 4/9/21 11:46 PM, 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 | 36 ++++++++++++++++++++++++++++++++++++
> doc/usage/arp.rst | 31 +++++++++++++++++++++++++++++++
> include/net.h | 5 +++++
> net/arp.c | 24 ++++++++++++++++++++++++
> net/arp.h | 4 ++++
> net/net.c | 8 ++++++++
> 7 files changed, 114 insertions(+)
> create mode 100644 doc/usage/arp.rst
>
> 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..369d15474c 100644
> --- a/cmd/net.c
> +++ b/cmd/net.c
> @@ -479,4 +479,40 @@ U_BOOT_CMD(
> ""
> );
>
Have a look at the #ifdef above in the code. I assume that the
dependency on CONFIG_CMD_LINK_LOCAL was not your intention.
> +#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
> +
> #endif /* CONFIG_CMD_LINK_LOCAL */
> 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
%s/ip/IP/
Why should the IP address be a required parameter? The most interesting
use case for the arp command is discovering neighbors.
On Linux 'arp -n' gives me the list of *all* devices in the same network
segment with both MAC address and IP address.
Can we do the same in U-Boot?
Best regards
Heinrich
> +
> +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();
>
>
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