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

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         | 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

On Sat, Apr 10, 2021 at 5:17 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         | 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;
> +       }
Why do we care about that ?
> +
> +       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
Typo, Synopsis
> +-------
> +
> +::
> +
> +    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
Typo, command
> 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
>