Managed HTTP transport: support user-agent

Author: ethomson

LibGit2Sharp/Core/ManagedHttpSmartSubtransport.cs

@@ -110,12 +110,24 @@ private bool CertificateValidationProxy(object sender, X509Certificate cert, X50
                 return true;
             }
 
+            private string getUserAgent()
+            {
+                string userAgent = GlobalSettings.GetUserAgent();
+
+                if (string.IsNullOrEmpty(userAgent))
+                {
+                    userAgent = "LibGit2Sharp " + GlobalSettings.Version.InformationalVersion;
+                }
+
+                return userAgent;
+            }
+
             private HttpWebRequest CreateWebRequest(Uri endpointUrl, bool isPost, string contentType)
             {
                 ServicePointManager.SecurityProtocol = SecurityProtocolType.Tls12;
 
                 HttpWebRequest webRequest = (HttpWebRequest)HttpWebRequest.Create(endpointUrl);
-                webRequest.UserAgent = "git/1.0 (libgit2 custom transport)";
+                webRequest.UserAgent = String.Format("git/2.0 ({0})", getUserAgent());
                 webRequest.ServicePoint.Expect100Continue = false;
                 webRequest.AllowAutoRedirect = false;
                 webRequest.ServerCertificateValidationCallback += CertificateValidationProxy;

LibGit2Sharp/Core/NativeMethods.cs

@@ -809,6 +809,15 @@ internal static extern int git_libgit2_opts(int option, uint level,
         // git_libgit2_opts(GIT_OPT_ENABLE_*, int enabled)
         [DllImport(libgit2, CallingConvention = CallingConvention.Cdecl)]
         internal static extern int git_libgit2_opts(int option, int enabled);
+
+        // git_libgit2_opts(GIT_OPT_SET_USER_AGENT, const char *path)
+        [DllImport(libgit2, CallingConvention = CallingConvention.Cdecl)]
+        internal static extern int git_libgit2_opts(int option,
+            [MarshalAs(UnmanagedType.CustomMarshaler, MarshalCookie = UniqueId.UniqueIdentifier, MarshalTypeRef = typeof(StrictUtf8Marshaler))] string path);
+
+        // git_libgit2_opts(GIT_OPT_GET_USER_AGENT, git_buf *buf)
+        [DllImport(libgit2, CallingConvention = CallingConvention.Cdecl)]
+        internal static extern int git_libgit2_opts(int option, GitBuf buf);
         #endregion
 
         [DllImport(libgit2, CallingConvention = CallingConvention.Cdecl)]

LibGit2Sharp/Core/Proxy.cs

@@ -3456,6 +3456,37 @@ public static void git_libgit2_opts_set_enable_strictobjectcreation(bool enabled
             Ensure.ZeroResult(res);
         }
 
+        /// <summary>
+        /// Sets the user-agent string to be used by the HTTP(S) transport.
+        /// Note that "git/2.0" will be prepended for compatibility.
+        /// </summary>
+        /// <param name="userAgent">The user-agent string to use</param>
+        public static void git_libgit2_opts_set_user_agent(string userAgent)
+        {
+            var res = NativeMethods.git_libgit2_opts((int)LibGit2Option.SetUserAgent, userAgent);
+            Ensure.ZeroResult(res);
+        }
+
+        /// <summary>
+        /// Gets the user-agent string used by libgit2.
+        /// <returns>
+        /// The user-agent string.
+        /// </returns>
+        public static string git_libgit2_opts_get_user_agent()
+        {
+            string userAgent;
+
+            using (var buf = new GitBuf())
+            {
+                var res = NativeMethods.git_libgit2_opts((int)LibGit2Option.GetUserAgent, buf);
+                Ensure.ZeroResult(res);
+
+                userAgent = LaxUtf8Marshaler.FromNative(buf.ptr) ?? string.Empty;
+            }
+
+            return userAgent;
+        }
+
         #endregion
 
         #region git_worktree_

LibGit2Sharp/GlobalSettings.cs

@@ -386,5 +386,25 @@ public static void SetEnableStrictObjectCreation(bool enabled)
         {
             Proxy.git_libgit2_opts_set_enable_strictobjectcreation(enabled);
         }
+
+        /// <summary>
+        /// Sets the user-agent string to be used by the HTTP(S) transport.
+        /// Note that "git/2.0" will be prepended for compatibility.
+        /// </summary>
+        /// <param name="userAgent">The user-agent string to use</param>
+        public static void SetUserAgent(string userAgent)
+        {
+            Proxy.git_libgit2_opts_set_user_agent(userAgent);
+        }
+
+        /// <summary>
+        /// Gets the user-agent string used by libgit2.
+        /// <returns>
+        /// The user-agent string.
+        /// </returns>
+        public static string GetUserAgent()
+        {
+            return Proxy.git_libgit2_opts_get_user_agent();
+        }
     }
 }