proxy: introduce a proxy options struct

It is currently unused; it will go into the remote's options.

include/git2.h

@@ -40,6 +40,7 @@
 #include "git2/pack.h"
 #include "git2/patch.h"
 #include "git2/pathspec.h"
+#include "git2/proxy.h"
 #include "git2/rebase.h"
 #include "git2/refdb.h"
 #include "git2/reflog.h"

include/git2/proxy.h

@@ -0,0 +1,91 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_git_proxy_h__
+#define INCLUDE_git_proxy_h__
+
+#include "common.h"
+#include "transport.h"
+
+GIT_BEGIN_DECL
+
+/**
+ * The type of proxy to use.
+ */
+typedef enum {
+	/**
+	 * Do not attempt to connect through a proxy
+	 */
+	GIT_PROXY_NONE,
+	/**
+	 * Try to auto-detect the proxy from the git configuration.
+	 */
+	GIT_PROXY_AUTO,
+	/**
+	 * Connect through a HTTP proxy
+	 */
+	GIT_PROXY_HTTP,
+	/**
+	 * Connect through a SOCKS v4 proxy
+	 */
+	GIT_PROXY_SOCKS4,
+	/**
+	 * Connect through a SOCKS v5 proxy
+	 */
+	GIT_PROXY_SOCKS5,
+} git_proxy_t;
+
+/**
+ * Options for connecting through a proxy
+ *
+ * Note that not all types may be supported, depending on the platform
+ * and compilation options.
+ */
+typedef struct {
+	unsigned int version;
+
+	/**
+	 * The type of proxy to use, by URL, auto-detect.
+	 */
+	git_proxy_t type;
+
+	/**
+	 * The URL of the proxy.
+	 */
+	const char *url;
+
+	/**
+	 * This will be called if the remote host requires
+	 * authentication in order to connect to it.
+	 *
+	 * Returning GIT_PASSTHROUGH will make libgit2 behave as
+	 * though this field isn't set.
+	 */
+	git_cred_acquire_cb credentials;
+
+	/**
+	 * If cert verification fails, this will be called to let the
+	 * user make the final decision of whether to allow the
+	 * connection to proceed. Returns 1 to allow the connection, 0
+	 * to disallow it or a negative value to indicate an error.
+	 */
+        git_transport_certificate_check_cb certificate_check;
+} git_proxy_options;
+
+#define GIT_PROXY_OPTIONS_VERSION 1
+#define GIT_PROXY_OPTIONS_INIT {GIT_PROXY_OPTIONS_VERSION}
+
+/**
+ * Initialize a proxy options structure
+ *
+ * @param opts the options struct to initialize
+ * @param version the version of the struct, use `GIT_PROXY_OPTIONS_VERSION`
+ */
+GIT_EXTERN(int) git_proxy_init_options(git_proxy_options *opts, unsigned int version);
+
+GIT_END_DECL
+
+#endif

src/proxy.c

@@ -0,0 +1,16 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+
+#include "common.h"
+#include "git2/proxy.h"
+
+int git_proxy_init_options(git_proxy_options *opts, unsigned int version)
+{
+	GIT_INIT_STRUCTURE_FROM_TEMPLATE(
+		opts, version, git_proxy_options, GIT_PROXY_OPTIONS_INIT);
+	return 0;
+}