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

[lgxue at hotmail.com]

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 ++++++++++++++++++++++++++++++++++++
 include/net.h |  5 +++++
 net/arp.c     | 24 ++++++++++++++++++++++++
 net/arp.h     |  4 ++++
 net/net.c     |  8 ++++++++
 6 files changed, 83 insertions(+)

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(
 	""
 );
 
+#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/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();
 
-- 
2.27.0