[PATCH v4] cmd: net: Add the "arp" command

[Heinrich Schuchardt]

Am 15. April 2021 15:22:30 MESZ schrieb 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>
>---

It is unclear what changed with respect to v3.

It is best practice to add this information after the 3 hyphens above to avoid inclusion in the git history, e.g.

---
v4
     removed foo
     added bar
----

Best regards

Heinrich

>
> 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
>
>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 command 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();
>