net: ipv6: Add ip6addr, gatewayip6, serverip6 variables callbacks

Implement actions on ip6addr, gatewayip6, serverip6 varaibles.
on_ip6addr - convert IPv6 string addr to struct ip6_addr
on_gatewayip6 - convert IPv6 string addr to struct ip6_addr
on_serverip6 - convert IPv6 string addr to struct ip6_addr

Series-changes: 3
- Removed memory allocation
- Substituted -1 for error code

Signed-off-by: Viacheslav Mitrofanov <v.v.mitrofanov@yadro.com>
Reviewed-by: Ramon Fried <rfried.dev@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>

net/net6.c

@@ -29,3 +29,51 @@ struct in6_addr net_server_ip6 = ZERO_IPV6_ADDR;
 u32 net_prefix_length;
 
 bool use_ip6;
+
+static int on_ip6addr(const char *name, const char *value, enum env_op op,
+		      int flags)
+{
+	char *mask;
+	size_t len;
+
+	if (flags & H_PROGRAMMATIC)
+		return 0;
+
+	if (op == env_op_delete) {
+		net_prefix_length = 0;
+		net_copy_ip6(&net_ip6, &net_null_addr_ip6);
+		return 0;
+	}
+
+	mask = strchr(value, '/');
+	len = strlen(value);
+
+	if (mask)
+		net_prefix_length = simple_strtoul(value + len, NULL, 10);
+
+	return string_to_ip6(value, len, &net_ip6);
+}
+
+U_BOOT_ENV_CALLBACK(ip6addr, on_ip6addr);
+
+static int on_gatewayip6(const char *name, const char *value, enum env_op op,
+			 int flags)
+{
+	if (flags & H_PROGRAMMATIC)
+		return 0;
+
+	return string_to_ip6(value, strlen(value), &net_gateway6);
+}
+
+U_BOOT_ENV_CALLBACK(gatewayip6, on_gatewayip6);
+
+static int on_serverip6(const char *name, const char *value, enum env_op op,
+			int flags)
+{
+	if (flags & H_PROGRAMMATIC)
+		return 0;
+
+	return string_to_ip6(value, strlen(value), &net_server_ip6);
+}
+
+U_BOOT_ENV_CALLBACK(serverip6, on_serverip6);