pro: Accept an optional proxy to tunnel the download through

For now, this only accepts the format `socks5://ip:port` (i.e. the
hostname has to be an ipv4, and the port must be present).

Userland/Libraries/LibCore/Proxy.h

@@ -7,7 +7,9 @@
 #pragma once
 
 #include <AK/Error.h>
+#include <AK/IPv4Address.h>
 #include <AK/Types.h>
+#include <AK/URL.h>
 #include <LibIPC/Forward.h>
 
 namespace Core {
@@ -22,6 +24,30 @@ struct ProxyData {
     int port { 0 };
 
     bool operator==(ProxyData const& other) const = default;
+
+    static ErrorOr<ProxyData> parse_url(URL const& url)
+    {
+        if (!url.is_valid())
+            return Error::from_string_literal("Invalid proxy URL");
+
+        ProxyData proxy_data;
+        if (url.scheme() != "socks5")
+            return Error::from_string_literal("Unsupported proxy type");
+
+        proxy_data.type = ProxyData::Type::SOCKS5;
+
+        auto host_ipv4 = IPv4Address::from_string(url.host());
+        if (!host_ipv4.has_value())
+            return Error::from_string_literal("Invalid proxy host, must be an IPv4 address");
+        proxy_data.host_ipv4 = host_ipv4->to_u32();
+
+        auto port = url.port();
+        if (!port.has_value())
+            return Error::from_string_literal("Invalid proxy, must have a port");
+        proxy_data.port = *port;
+
+        return proxy_data;
+    }
 };
 }
 

Userland/Utilities/pro.cpp

@@ -151,6 +151,7 @@ ErrorOr<int> serenity_main(Main::Arguments arguments)
     bool save_at_provided_name = false;
     bool should_follow_url = false;
     char const* data = nullptr;
+    StringView proxy_spec;
     String method = "GET";
     HashMap<String, String, CaseInsensitiveStringTraits> request_headers;
 
@@ -175,6 +176,7 @@ ErrorOr<int> serenity_main(Main::Arguments arguments)
             request_headers.set(header.substring_view(0, split.value()), header.substring_view(split.value() + 1));
             return true;
         } });
+    args_parser.add_option(proxy_spec, "Specify a proxy server to use for this request (proto://ip:port)", "proxy", 'p', "proxy");
     args_parser.add_positional_argument(url_str, "URL to download from", "url");
     args_parser.parse(arguments);
 
@@ -189,6 +191,8 @@ ErrorOr<int> serenity_main(Main::Arguments arguments)
         return 1;
     }
 
+    Core::ProxyData proxy_data = TRY(Core::ProxyData::parse_url(proxy_spec));
+
     Core::EventLoop loop;
     bool received_actual_headers = false;
     bool should_save_stream_data = false;
@@ -287,7 +291,7 @@ ErrorOr<int> serenity_main(Main::Arguments arguments)
 
                     Core::deferred_invoke([&, was_following_url, url = location.value()] {
                         warnln("{}Following to {}", was_following_url ? "" : "\n", url);
-                        request = protocol_client->start_request(method, url, request_headers, ReadonlyBytes {});
+                        request = protocol_client->start_request(method, url, request_headers, ReadonlyBytes {}, proxy_data);
                         setup_request();
                     });
                 }
@@ -309,7 +313,7 @@ ErrorOr<int> serenity_main(Main::Arguments arguments)
         request->stream_into(output_stream);
     };
 
-    request = protocol_client->start_request(method, url, request_headers, data ? StringView { data }.bytes() : ReadonlyBytes {});
+    request = protocol_client->start_request(method, url, request_headers, data ? StringView { data }.bytes() : ReadonlyBytes {}, proxy_data);
     setup_request();
 
     dbgln("started request with id {}", request->id());