2 files changed, 24 insertions, 26 deletions

diff --git a/include/zaprus.h b/include/zaprus.h
index 6856a5e..51ac70c 100644
--- a/include/zaprus.h
+++ b/include/zaprus.h
@@ -20,13 +20,12 @@ struct SaprusMessage* zaprus_connect(const char* payload, size_t len);
 
 struct SaprusMessage {
   uint16_t packet_type;
+  uint16_t payload_len;
   union {
     struct {
       struct {
 	char dest[4];
       };
-      size_t payload_len;
-      char *payload;
     } relay;
     struct {
       struct {
@@ -37,10 +36,10 @@ struct SaprusMessage {
 	char _reserved;
 	char options;
       };
-      size_t payload_len;
-      char *payload;
+      
     } connection;
-  };
+  } headers;
+  char *payload;
 };
 
 // ptr should be freed by the caller.
diff --git a/src/c_api.zig b/src/c_api.zig
index a0343ae..7be260e 100644
--- a/src/c_api.zig
+++ b/src/c_api.zig
@@ -2,38 +2,38 @@ const c = @cImport({
     @cInclude("zaprus.h");
 });
 
-fn zigToCMessage(msg: ?*zaprus.Message) ?*c.SaprusMessage {
+fn zigToCMessage(msg: ?*zaprus.Message) !?*c.SaprusMessage {
     if (msg) |m| {
         var res = c.SaprusMessage{
             .packet_type = @intFromEnum(m.*),
         };
         switch (m.*) {
             .relay => |r| {
-                res.unnamed_0 = .{ .relay = .{
+                res.headers.relay = .{
                     .unnamed_0 = .{
                         .dest = r.header.dest,
                     },
-                    .payload_len = r.payload.len,
-                    .payload = (allocator.alloc(u8, r.payload.len) catch return null).ptr,
-                } };
+                };
+                res.payload_len = @intCast(r.payload.len);
+                res.payload = (try allocator.alloc(u8, r.payload.len)).ptr;
             },
             .connection => |con| {
-                res.unnamed_0 = .{
-                    .connection = .{
-                        .unnamed_0 = .{
-                            .src_port = con.header.src_port,
-                            .dest_port = con.header.dest_port,
-                            .seq_num = con.header.seq_num,
-                            .msg_id = con.header.msg_id,
-                            ._reserved = con.header.reserved,
-                            .options = @bitCast(con.header.options),
-                        },
-                        .payload_len = con.payload.len,
-                        .payload = (allocator.alloc(u8, con.payload.len) catch return null).ptr,
+                res.headers.connection = .{
+                    .unnamed_0 = .{
+                        .src_port = con.header.src_port,
+                        .dest_port = con.header.dest_port,
+                        .seq_num = con.header.seq_num,
+                        .msg_id = con.header.msg_id,
+                        ._reserved = con.header.reserved,
+                        .options = @bitCast(con.header.options),
                     },
                 };
+
+                res.payload_len = @intCast(con.payload.len);
+                res.payload = (try allocator.alloc(u8, con.payload.len)).ptr;
             },
-            else => return null,
+            .file_transfer => return zaprus.Error.NotImplementedSaprusType,
+            else => return zaprus.Error.UnknownSaprusType,
         }
         return &res;
     } else return null;
@@ -72,7 +72,7 @@ export fn zaprus_send_initial_connection(payload: [*]const u8, len: usize, initi
 
 export fn zaprus_connect(payload: [*]const u8, len: usize) ?*c.SaprusMessage {
     if (SaprusClient.connect(payload[0..len], allocator)) |msg| {
-        return zigToCMessage(@constCast(&(msg.?)));
+        return zigToCMessage(@constCast(&(msg.?))) catch null;
     } else |_| {
         return null;
     }
@@ -93,7 +93,7 @@ export fn zaprus_message_to_bytes(msg: c.SaprusMessage, ptr: *[*]u8, len: *usize
 /// Return value should be destroyed with zaprus_message_deinit.
 export fn zaprus_message_from_bytes(bytes: [*]const u8, len: usize) ?*c.SaprusMessage {
     if (zaprus.Message.fromBytes(bytes[0..len], allocator)) |msg| {
-        return zigToCMessage(@constCast(&msg));
+        return zigToCMessage(@constCast(&msg)) catch null;
     } else |_| return null;
 }
 
@@ -107,7 +107,6 @@ const std = @import("std");
 
 const zaprus = @import("./root.zig");
 const SaprusClient = zaprus.Client;
-// const SaprusMessage = zaprus.Message;
 
 const allocator = std.heap.c_allocator;