poc: custom http transport for sentry-native to eliminate curl

Author: jpnurmi

CHANGELOG.md

@@ -5,6 +5,7 @@
 ### Features
 
 - Rename MemoryInfo.AllocatedBytes to MemoryInfo.TotalAllocatedBytes ([#4243](https://github.com/getsentry/sentry-dotnet/pull/4243))
+- Replace libcurl with .NET HttpClient for sentry-native ([#4222](https://github.com/getsentry/sentry-dotnet/pull/4222))
 
 ## 5.9.0
 

scripts/build-sentry-native.ps1

@@ -69,6 +69,7 @@ try
         -D SENTRY_SDK_NAME=sentry.native.dotnet `
         -D SENTRY_BUILD_SHARED_LIBS=0 `
         -D SENTRY_BACKEND=inproc `
+        -D SENTRY_TRANSPORT=none `
         $additionalArgs
 
     cmake `

src/Sentry/Http/HttpTransportBase.cs

@@ -187,20 +187,8 @@ protected internal virtual HttpRequestMessage CreateRequest(Envelope envelope)
             throw new InvalidOperationException("The DSN is expected to be set at this point.");
         }
 
-        var dsn = Dsn.Parse(_options.Dsn);
-        var authHeader =
-            $"Sentry sentry_version={_options.SentryVersion}," +
-            $"sentry_client={SdkVersion.Instance.Name}/{SdkVersion.Instance.Version}," +
-            $"sentry_key={dsn.PublicKey}" +
-            (dsn.SecretKey is { } secretKey ? $",sentry_secret={secretKey}" : null);
-
-        return new HttpRequestMessage
-        {
-            RequestUri = dsn.GetEnvelopeEndpointUri(),
-            Method = HttpMethod.Post,
-            Headers = { { "X-Sentry-Auth", authHeader } },
-            Content = new EnvelopeHttpContent(envelope, _options.DiagnosticLogger, _clock)
-        };
+        var content = new EnvelopeHttpContent(envelope, _options.DiagnosticLogger, _clock);
+        return _options.CreateHttpRequest(content);
     }
 
     /// <summary>

src/Sentry/Platforms/Native/CFunctions.cs

@@ -139,6 +139,14 @@ public static bool Init(SentryOptions options)
             }
         }
 
+        unsafe
+        {
+            var cTransport = sentry_transport_new(&nativeTransport);
+            sentry_transport_set_state(cTransport, GCHandle.ToIntPtr(GCHandle.Alloc(options)));
+            sentry_transport_set_free_func(cTransport, &nativeTransportFree);
+            sentry_options_set_transport(cOptions, cTransport);
+        }
+
         options.DiagnosticLogger?.LogDebug("Initializing sentry native");
         return 0 == sentry_init(cOptions);
     }
@@ -364,6 +372,61 @@ internal struct sentry_value_t
     [DllImport("sentry-native")]
     private static extern void sentry_options_set_auto_session_tracking(IntPtr options, int debug);
 
+    [DllImport("sentry-native")]
+    private static extern void sentry_options_set_transport(IntPtr options, IntPtr transport);
+
+    [DllImport("sentry-native")]
+    private static extern unsafe IntPtr sentry_transport_new(delegate* unmanaged/*[Cdecl]*/<IntPtr, IntPtr, void> sendFunc);
+
+    [DllImport("sentry-native")]
+    private static extern void sentry_transport_set_state(IntPtr transport, IntPtr state);
+
+    [DllImport("sentry-native")]
+    private static extern unsafe void sentry_transport_set_free_func(IntPtr transport, delegate* unmanaged/*[Cdecl]*/<IntPtr, void> freeFunc);
+
+    [DllImport("sentry-native")]
+    private static extern IntPtr sentry_envelope_serialize(IntPtr envelope, out UIntPtr sizeOut);
+
+    [DllImport("sentry-native")]
+    private static extern void sentry_envelope_free(IntPtr envelope);
+
+    [DllImport("sentry-native")]
+    private static extern void sentry_free(IntPtr ptr);
+
+    [UnmanagedCallersOnly]
+    private static void nativeTransport(IntPtr envelope, IntPtr state)
+    {
+        try
+        {
+            var options = GCHandle.FromIntPtr(state).Target as SentryOptions;
+            if (options is not null)
+            {
+                var data = sentry_envelope_serialize(envelope, out var size);
+                var content = new StringContent(Marshal.PtrToStringAnsi(data, (int)size));
+                sentry_free(data);
+
+                using var client = options.GetHttpClient();
+                using var request = options.CreateHttpRequest(content);
+                client.SendAsync(request).GetAwaiter().GetResult();
+            }
+        }
+        catch
+        {
+            // never allow an exception back to native code - it would crash the app
+        }
+        finally
+        {
+            sentry_envelope_free(envelope);
+        }
+    }
+
+    [UnmanagedCallersOnly]
+    private static void nativeTransportFree(IntPtr state)
+    {
+        var handle = GCHandle.FromIntPtr(state);
+        handle.Free();
+    }
+
     [DllImport("sentry-native")]
     private static extern unsafe void sentry_options_set_logger(IntPtr options, delegate* unmanaged/*[Cdecl]*/<int, IntPtr, IntPtr, IntPtr, void> logger, IntPtr userData);
 

src/Sentry/Platforms/Native/buildTransitive/Sentry.Native.targets

@@ -36,8 +36,6 @@
   <ItemGroup Condition="'$(FrameworkSupportsNative)' == 'true' and ('$(RuntimeIdentifier)' == 'linux-x64' or '$(RuntimeIdentifier)' == 'linux-arm64')">
     <DirectPInvoke Include="sentry-native" />
     <NativeLibrary Include="$(MSBuildThisFileDirectory)..\sentry-native\$(RuntimeIdentifier)\libsentry-native.a" />
-    <!-- See: https://github.com/dotnet/runtime/issues/97414 -->
-    <NativeSystemLibrary Include="curl" />
   </ItemGroup>
 
   <ItemGroup Condition="'$(FrameworkSupportsNative)' == 'true' and '$(RuntimeIdentifier)' == 'linux-musl-x64'">
@@ -46,13 +44,10 @@
     <LinkerArg Include="-Wl,-Bstatic -Wl,--whole-archive -lunwind -Wl,--no-whole-archive -Wl,-Bdynamic" />
     <NativeSystemLibrary Include="lzma" />
     <NativeLibrary Include="$(MSBuildThisFileDirectory)..\sentry-native\linux-musl-x64\libsentry-native.a" />
-    <!-- See: https://github.com/dotnet/runtime/issues/97414 -->
-    <NativeSystemLibrary Include="curl" />
   </ItemGroup>
 
   <ItemGroup Condition="'$(FrameworkSupportsNative)' == 'true' and ('$(RuntimeIdentifier)' == 'osx-x64' or '$(RuntimeIdentifier)' == 'osx-arm64')">
     <DirectPInvoke Include="sentry-native" />
     <NativeLibrary Include="$(MSBuildThisFileDirectory)..\sentry-native\osx\libsentry-native.a" />
-    <NativeSystemLibrary Include="curl" />
   </ItemGroup>
 </Project>

src/Sentry/SentryOptions.cs

@@ -245,6 +245,23 @@ internal HttpClient GetHttpClient()
         return factory.Create(this);
     }
 
+    internal HttpRequestMessage CreateHttpRequest(HttpContent content)
+    {
+        var authHeader =
+            $"Sentry sentry_version={SentryVersion}," +
+            $"sentry_client={SdkVersion.Instance.Name}/{SdkVersion.Instance.Version}," +
+            $"sentry_key={ParsedDsn.PublicKey}" +
+            (ParsedDsn.SecretKey is { } secretKey ? $",sentry_secret={secretKey}" : null);
+
+        return new HttpRequestMessage
+        {
+            RequestUri = ParsedDsn.GetEnvelopeEndpointUri(),
+            Method = HttpMethod.Post,
+            Headers = { { "X-Sentry-Auth", authHeader } },
+            Content = content
+        };
+    }
+
     /// <summary>
     /// Scope state processor.
     /// </summary>