Re: [PATCH v2] cmd: net: Add the "arp" command

On 4/9/21 11:46 PM, lgxue@hotmail.com wrote:

From: Joe Xue lgxue@hotmail.com

The command is to query and show mac address of a specific ipAddress.

Signed-off-by: Joe Xue lgxue@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();