net: wget: add wget with dns utility function

Current wget takes the target uri in this format:
 "<http server ip>:<file path>"  e.g.) 192.168.1.1:/bar
The http server ip address must be resolved before
calling wget.

This commit adds the utility function runs wget with dhs.
User can call wget with the uri like "http://foo/bar".

Signed-off-by: Masahisa Kojima <masahisa.kojima@linaro.org>
Reviewed-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
Reviewed-by: Ramon Fried <rfried.dev@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
diff --git a/include/net.h b/include/net.h
index e63a946..61f9018 100644
--- a/include/net.h
+++ b/include/net.h
@@ -930,4 +930,13 @@
 static inline void eth_set_enable_bootdevs(bool enable) {}
 #endif
 
+/**
+ * wget_with_dns() - runs dns host IP address resulution before wget
+ *
+ * @dst_addr:	destination address to download the file
+ * @uri:	uri string of target file of wget
+ * Return:	downloaded file size, negative if failed
+ */
+int wget_with_dns(ulong dst_addr, char *uri);
+
 #endif /* __NET_H__ */
diff --git a/net/wget.c b/net/wget.c
index 6f97eb1..2087146 100644
--- a/net/wget.c
+++ b/net/wget.c
@@ -15,6 +15,7 @@
 #include <net.h>
 #include <net/tcp.h>
 #include <net/wget.h>
+#include <stdlib.h>
 
 DECLARE_GLOBAL_DATA_PTR;
 
@@ -512,3 +513,56 @@
 
 	wget_send(TCP_SYN, 0, 0, 0);
 }
+
+#if (IS_ENABLED(CONFIG_CMD_DNS))
+int wget_with_dns(ulong dst_addr, char *uri)
+{
+	int ret;
+	char *s, *host_name, *file_name, *str_copy;
+
+	/*
+	 * Download file using wget.
+	 *
+	 * U-Boot wget takes the target uri in this format.
+	 *  "<http server ip>:<file path>"  e.g.) 192.168.1.1:/sample/test.iso
+	 * Need to resolve the http server ip address before starting wget.
+	 */
+	str_copy = strdup(uri);
+	if (!str_copy)
+		return -ENOMEM;
+
+	s = str_copy + strlen("http://");
+	host_name = strsep(&s, "/");
+	if (!s) {
+		log_err("Error: invalied uri, no file path\n");
+		ret = -EINVAL;
+		goto out;
+	}
+	file_name = s;
+
+	/* TODO: If the given uri has ip address for the http server, skip dns */
+	net_dns_resolve = host_name;
+	net_dns_env_var = "httpserverip";
+	if (net_loop(DNS) < 0) {
+		log_err("Error: dns lookup of %s failed, check setup\n", net_dns_resolve);
+		ret = -EINVAL;
+		goto out;
+	}
+	s = env_get("httpserverip");
+	if (!s) {
+		ret = -EINVAL;
+		goto out;
+	}
+
+	strlcpy(net_boot_file_name, s, sizeof(net_boot_file_name));
+	strlcat(net_boot_file_name, ":/", sizeof(net_boot_file_name)); /* append '/' which is removed by strsep() */
+	strlcat(net_boot_file_name, file_name, sizeof(net_boot_file_name));
+	image_load_addr = dst_addr;
+	ret = net_loop(WGET);
+
+out:
+	free(str_copy);
+
+	return ret;
+}
+#endif