Add a workaround for JavaScript truncating integers in RPC.

2 files changed, 46 insertions, 5 deletions

diff --git a/data/modules.example.conf b/data/modules.example.conf
index c317cd6cf..93aa0df54 100644
--- a/data/modules.example.conf
+++ b/data/modules.example.conf
@@ -810,6 +810,19 @@ module
 {
 	name = "jsonrpc"
 
+	/*
+	 * The maximum number of bits an integer can be have in its native type.
+	 *
+	 * By default Anope will emit integers as their native JSON type. If you are
+	 * using JavaScript (which has 56 bit integers) or another language with
+	 * native integer types smaller than 64 bits you may need to limit the size
+	 * of integers emitted by Anope.
+	 *
+	 * If this is enabled a string will be used for values outside of the range
+	 * supported by the native data type.
+	 */
+	#integer_bits = 56
+
 	/* Web service to use. Requires httpd. */
 	server = "httpd/main"
 
@@ -852,9 +865,6 @@ module
 {
 	name = "xmlrpc"
 
-	/* Web service to use. Requires httpd. */
-	server = "httpd/main"
-
 	/*
 	 * Whether to enable the use of XML-RPC extensions.
 	 *
@@ -869,6 +879,9 @@ module
 	#enable_i8 = no
 	#enable_nil = no
 
+	/* Web service to use. Requires httpd. */
+	server = "httpd/main"
+
 	/*
 	 * You can also specify one or more authorization tokens to protect access
 	 * to the XML-RPC interface. These tokens should be sent using the Bearer
diff --git a/modules/rpc/jsonrpc.cpp b/modules/rpc/jsonrpc.cpp
index 163658495..189e2b3a8 100644
--- a/modules/rpc/jsonrpc.cpp
+++ b/modules/rpc/jsonrpc.cpp
@@ -86,6 +86,9 @@ private:
 	}
 
 public:
+	// The number of bits that can be represented using the native integer type.
+	static unsigned integer_bits;
+
 	JSONRPCServiceInterface(Module *creator)
 		: RPC::ServiceInterface(creator)
 		, HTTPPage("/jsonrpc", "application/json")
@@ -236,16 +239,39 @@ yyjson_mut_val *JSONRPCServiceInterface::SerializeElement(yyjson_mut_doc *doc, c
 		},
 		[&doc, &elem](int64_t i)
 		{
-			elem = yyjson_mut_int(doc, i);
+			auto bits =	std::floor(std::log2(abs(i))) + 1;
+			if (bits <= integer_bits)
+			{
+				// We can fit this into an integer.
+				elem = yyjson_mut_int(doc, i);
+			}
+			else
+			{
+				// We need to convert this to a string.
+				auto s = Anope::ToString(i);
+				elem = yyjson_mut_strncpy(doc, s.c_str(), s.length());
+			}
 		},
 		[&doc, &elem](uint64_t u)
 		{
-			elem = yyjson_mut_uint(doc, u);
+			auto bits =	std::floor(std::log2(u)) + 1;
+			if (bits <= integer_bits)
+			{
+				// We can fit this into an integer.
+				elem = yyjson_mut_uint(doc, u);
+			}
+			else
+			{
+				// We need to convert this to a string.
+				auto s = Anope::ToString(u);
+				elem = yyjson_mut_strncpy(doc, s.c_str(), s.length());
+			}
 		},
 	}, value.Get());
 	return elem;
 }
 
+unsigned JSONRPCServiceInterface::integer_bits = 64;
 
 class ModuleJSONRPC final
 	: public Module
@@ -273,6 +299,8 @@ public:
 			httpref->UnregisterPage(&jsonrpcinterface);
 
 		const auto &modconf = conf.GetModule(this);
+		JSONRPCServiceInterface::integer_bits = modconf.Get<unsigned>("integer_bits", "64");
+
 		this->httpref = ServiceReference<HTTPProvider>("HTTPProvider", modconf.Get<const Anope::string>("server", "httpd/main"));
 		if (!httpref)
 			throw ConfigException("Unable to find http reference, is httpd loaded?");