Implement support for JSON logging.

.github/workflows/ci-alpine.yml

@@ -35,12 +35,13 @@ jobs:
             pcre2-dev \
             perl \
             pkgconf \
+            rapidjson-dev \
             re2-dev \
             sqlite-dev
 
       - name: Run configure
         run: |
-          ./configure --enable-extras "argon2 geo_maxmind ldap log_syslog mysql pgsql regex_pcre regex_posix regex_re2 sqlite3 ssl_gnutls ssl_mbedtls ssl_openssl sslrehashsignal"
+          ./configure --enable-extras "argon2 geo_maxmind ldap log_json log_syslog mysql pgsql regex_pcre regex_posix regex_re2 sqlite3 ssl_gnutls ssl_mbedtls ssl_openssl sslrehashsignal"
           ./configure --development --disable-auto-extras --disable-ownership --socketengine ${{ matrix.socketengine }}
 
       - name: Build core

.github/workflows/ci-linux.yml

@@ -34,11 +34,12 @@ jobs:
             libsqlite3-dev \
             libssl-dev \
             make \
-            pkg-config
+            pkg-config \
+            rapidjson-dev
 
       - name: Run configure
         run: |
-          ./configure --enable-extras "argon2 geo_maxmind ldap log_syslog mysql pgsql regex_pcre regex_posix regex_re2 sqlite3 ssl_gnutls ssl_mbedtls ssl_openssl sslrehashsignal"
+          ./configure --enable-extras "argon2 geo_maxmind ldap log_json log_syslog mysql pgsql regex_pcre regex_posix regex_re2 sqlite3 ssl_gnutls ssl_mbedtls ssl_openssl sslrehashsignal"
           ./configure --development --disable-auto-extras --socketengine ${{ matrix.socketengine }}
 
       - name: Build core

.github/workflows/ci-macos.yml

@@ -18,7 +18,7 @@ jobs:
       - name: Install dependencies
         run: |
           brew update || true
-          for PACKAGE in pkg-config argon2 gnutls libmaxminddb libpq mbedtls mysql-client openssl@3 pcre2 re2 sqlite;
+          for PACKAGE in pkg-config argon2 gnutls libmaxminddb libpq mbedtls mysql-client openssl@3 pcre2 re2 rapidjson sqlite;
           do
             brew install $PACKAGE || brew upgrade $PACKAGE
 
@@ -37,7 +37,7 @@ jobs:
 
       - name: Run configure
         run: |
-          ./configure --enable-extras "argon2 geo_maxmind ldap log_syslog mysql pgsql regex_pcre regex_posix regex_re2 sqlite3 ssl_gnutls ssl_mbedtls ssl_openssl sslrehashsignal"
+          ./configure --enable-extras "argon2 geo_maxmind ldap log_json log_syslog mysql pgsql regex_pcre regex_posix regex_re2 sqlite3 ssl_gnutls ssl_mbedtls ssl_openssl sslrehashsignal"
           ./configure --development --disable-auto-extras --socketengine ${{ matrix.socketengine }}
 
       - name: Build core

.gitignore

@@ -17,6 +17,7 @@
 /src/modules/m_argon2.cpp
 /src/modules/m_geo_maxmind.cpp
 /src/modules/m_ldap.cpp
+/src/modules/m_log_json.cpp
 /src/modules/m_log_syslog.cpp
 /src/modules/m_mysql.cpp
 /src/modules/m_pgsql.cpp

configure

@@ -395,6 +395,7 @@ if (prompt_bool $interactive, $question, 0) {
 		'm_mysql.cpp'           => 'mysql_config --version',
 		'm_pgsql.cpp'           => 'pg_config --version',
 		'm_ldap.cpp'            => "echo '#include <ldap.h>' | $config{CXX} -E -",
+		'm_log_json.cpp'        => 'pkg-config --exists RapidJSON',
 		'm_log_syslog.cpp'      => undef,
 		'm_regex_pcre.cpp'      => 'pkg-config --exists libpcre2-8',
 		'm_regex_posix.cpp'     => undef,

docs/conf/modules.conf.example

@@ -1366,6 +1366,17 @@
 # opers are to be authenticated via LDAP, so in case this module is   #
 # not loaded the oper accounts are still protected by a password.     #
 
+#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#
+# JSON logging module: Allows writing messages to the system log.     #
+# This module is in extras. Re-run configure with:                    #
+# ./configure --enable-extras log_json
+#<module name="log_json">
+#
+#<log method="json"
+#     target="inspircd.json"
+#     level="normal"
+#     type="* -USERINPUT -USEROUTPUT">
+
 #-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#
 # SQL logging module: Allows writing messages to an SQL database..    #
 #<module name="log_sql">

src/modules/extra/m_log_json.cpp

@@ -0,0 +1,152 @@
+/*
+ * InspIRCd -- Internet Relay Chat Daemon
+ *
+ *   Copyright (C) 2022 Sadie Powell <sadie@witchery.services>
+ *
+ * This file is part of InspIRCd.  InspIRCd is free software: you can
+ * redistribute it and/or modify it under the terms of the GNU General Public
+ * License as published by the Free Software Foundation, version 2.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+ * FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more
+ * details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+/// $CompilerFlags: find_compiler_flags("RapidJSON")
+
+
+#include "inspircd.h"
+
+#include <rapidjson/ostreamwrapper.h>
+#include <rapidjson/writer.h>
+
+class JSONMethod final
+	: public Log::Method
+{
+private:
+	// The file to which the log is written.
+	FILE* file;
+
+	// How often the file stream should be flushed.
+	const unsigned long flush;
+
+	// The number of lines which have been written since the file stream was created.
+	unsigned long lines = 0;
+
+	/// The name the underlying file.
+	const std::string name;
+
+public:
+	// RapidJSON API: The type of character that this writer accepts.
+	typedef char Ch;
+
+	JSONMethod(const std::string& n, FILE* fh, unsigned long fl) ATTR_NOT_NULL(3)
+		: file(fh)
+		, flush(fl)
+		, name(n)
+	{
+	}
+
+	~JSONMethod()
+	{
+		fclose(file);
+	}
+
+	// RapidJSON API: We implement our own flushing in OnLog.
+	void Flush() { }
+
+	void OnLog(Log::Level level, const std::string& type, const std::string& message) override
+	{
+		static time_t prevtime = 0;
+		static std::string timestr;
+		if (prevtime != ServerInstance->Time())
+		{
+			prevtime = ServerInstance->Time();
+			timestr = InspIRCd::TimeString(prevtime, "%Y-%m-%dT%H:%M:%S%z");
+		}
+
+		rapidjson::Writer writer(*this);
+		writer.StartObject();
+		{
+			writer.Key("time");
+			writer.String(timestr.c_str(), static_cast<rapidjson::SizeType>(timestr.size()));
+
+			writer.Key("type");
+			writer.String(type.c_str(), static_cast<rapidjson::SizeType>(type.size()));
+
+			writer.Key("level");
+			const std::string levelstr = Log::LevelToString(level);
+			writer.String(levelstr.c_str(), static_cast<rapidjson::SizeType>(levelstr.size()));
+
+			writer.Key("message");
+			writer.Key(message.c_str(), static_cast<rapidjson::SizeType>(message.size()));
+		}
+		writer.EndObject();
+
+#ifdef _WIN32
+	fputs("\r\n", file);
+#else
+	fputs("\n", file);
+#endif
+
+		if (!(++lines % flush))
+			fflush(file);
+
+		if (ferror(file))
+			throw CoreException(InspIRCd::Format("Unable to write to %s: %s", name.c_str(), strerror(errno)));
+	}
+
+	// RapidJSON API: Write a character to the file.
+	void Put(Ch c)
+	{
+		fputc(c, file);
+	}
+};
+
+class JSONEngine final
+	: public Log::Engine
+{
+public:
+	JSONEngine(Module* Creator) ATTR_NOT_NULL(2)
+		: Log::Engine(Creator, "json")
+	{
+	}
+
+	Log::MethodPtr Create(std::shared_ptr<ConfigTag> tag) override
+	{
+		const std::string target = tag->getString("target");
+		if (target.empty())
+			throw CoreException("<log:target> must be specified for JSON logger at " + tag->source.str());
+
+		const std::string fulltarget = ServerInstance->Config->Paths.PrependLog(InspIRCd::TimeString(ServerInstance->Time(), target.c_str()));
+		FILE* fh = fopen(fulltarget.c_str(), "a");
+		if (!fh)
+		{
+			throw CoreException(InspIRCd::Format("Unable to open %s for JSON logger at %s: %s",
+				fulltarget.c_str(), tag->source.str().c_str(), strerror(errno)));
+		}
+
+		const unsigned long flush = tag->getUInt("flush", 20, 1);
+		return std::make_shared<JSONMethod>(fulltarget, fh, flush);
+	}
+};
+
+class ModuleLogJSON final
+	: public Module
+{
+private:
+	JSONEngine engine;
+
+public:
+	ModuleLogJSON()
+		: Module(VF_VENDOR, "Provides the ability to write logs to syslog.")
+		, engine(this)
+	{
+	}
+};
+
+MODULE_INIT(ModuleLogJSON)

win/conanfile.txt

@@ -12,6 +12,7 @@ libpq/14.2
 ## mbedtls/3.1.0
 ## openssl/1.1.1n # unable to upgrade yet because of dependency issues
 pcre2/10.40
+rapidjson/cci.20211112
 re2/20220201
 sqlite3/3.38.1
 

win/modules/CMakeLists.txt

@@ -12,6 +12,7 @@ if(EXISTS "${CMAKE_BINARY_DIR}/conanbuildinfo.cmake")
 
 	enable_extra("argon2" "ARGON2")
 	enable_extra("geo_maxmind" "LIBMAXMINDDB")
+	enable_extra("log_json" "RAPIDJSON")
 	enable_extra("mysql" "LIBMYSQLCLIENT")
 	enable_extra("pgsql" "LIBPQ")
 	enable_extra("regex_pcre" "PCRE2")