socks proxy: allow socks5h:// prefix too

Using 'socks5h' as proxy protocol will make it a
CURLPROXY_SOCKS5_HOSTNAME proxy which is SOCKS5 and asking the proxy to
resolve host names. I found no "standard" protocol name for this.

2 files changed, 8 insertions, 4 deletions

diff --git a/docs/libcurl/curl_easy_setopt.3 b/docs/libcurl/curl_easy_setopt.3
index 55b0db5ba..2494ecc15 100644
--- a/docs/libcurl/curl_easy_setopt.3
+++ b/docs/libcurl/curl_easy_setopt.3
@@ -634,9 +634,11 @@ specified the exact same way as the proxy can be set with \fICURLOPT_PROXY\fP,
 include protocol prefix (http://) and embedded user + password.
 
 Since 7.21.7, the proxy string may be specified with a protocol:// prefix to
-specify alternative proxy protocols. Use socks4://, socks4a:// or socks5:// to
-request the specific SOCKS version to be used. No protocol specified, http://
-and all others will be treated as HTTP proxies.
+specify alternative proxy protocols. Use socks4://, socks4a://, socks5:// or
+socks5h:// (the last one to enable socks5 and asking the proxy to do the
+resolving, also known as CURLPROXY_SOCKS5_HOSTNAME type) to request the
+specific SOCKS version to be used. No protocol specified, http:// and all
+others will be treated as HTTP proxies.
 .IP CURLOPT_PROXYPORT
 Pass a long with this option to set the proxy port to connect to unless it is
 specified in the proxy string \fICURLOPT_PROXY\fP.
diff --git a/lib/url.c b/lib/url.c
index edbb16429..22f8b3391 100644
--- a/lib/url.c
+++ b/lib/url.c
@@ -4069,7 +4069,9 @@ static CURLcode parse_proxy(struct SessionHandle *data,
   endofprot = strstr(proxy, "://");
   if(endofprot) {
     proxyptr = endofprot+3;
-    if(checkprefix("socks5", proxy))
+    if(checkprefix("socks5h", proxy))
+      conn->proxytype = CURLPROXY_SOCKS5_HOSTNAME;
+    else if(checkprefix("socks5", proxy))
       conn->proxytype = CURLPROXY_SOCKS5;
     else if(checkprefix("socks4a", proxy))
       conn->proxytype = CURLPROXY_SOCKS4A;