net: shell: Add MAC address validation

Validate MAC address before setting, add new helper APIs to cover all
cases.

Signed-off-by: Krishna T <[email protected]>

Author: Krishna T

include/zephyr/net/ethernet.h

@@ -670,6 +670,16 @@ static inline bool net_eth_is_addr_multicast(struct net_eth_addr *addr)
 	return false;
 }
 
+static inline bool net_eth_is_addr_group(struct net_eth_addr *addr)
+{
+	return addr->addr[0] & 0x01;
+}
+
+static inline bool net_eth_is_addr_valid(struct net_eth_addr *addr)
+{
+	return !net_eth_is_addr_unspecified(addr) && !net_eth_is_addr_group(addr);
+}
+
 static inline bool net_eth_is_addr_lldp_multicast(struct net_eth_addr *addr)
 {
 #if defined(CONFIG_NET_GPTP) || defined(CONFIG_NET_LLDP)

subsys/net/ip/net_shell.c

@@ -3598,8 +3598,9 @@ static int cmd_net_set_mac(const struct shell *sh, size_t argc, char *argv[])
 		goto err;
 	}
 
-	if (net_bytes_from_str(mac_addr.addr, sizeof(mac_addr), argv[2]) < 0) {
-		PR_WARNING("Invalid MAC address\n");
+	if ((net_bytes_from_str(mac_addr.addr, sizeof(mac_addr), argv[2]) < 0) ||
+	    !net_eth_is_addr_valid(&mac_addr)) {
+		PR_WARNING("Invalid MAC address: %s\n", argv[2]);
 		goto err;
 	}
 
@@ -3613,6 +3614,10 @@ static int cmd_net_set_mac(const struct shell *sh, size_t argc, char *argv[])
 		goto err;
 	}
 
+	PR_INFO("MAC address set to %s\n",
+		net_sprint_ll_addr(net_if_get_link_addr(iface)->addr,
+		net_if_get_link_addr(iface)->len));
+
 	return 0;
 err:
 	return -ENOEXEC;