NetworkPluginServer: handle argc/argv sanely when spawning backends

- The old code did some really silly things when spawning backends -
  on the level of "make the arguments into one string and then parse" (!)
- We now actually use std::vector and do this the competent way.
- Plus, no more dependency on popt, which I can't believe was ever
  included...!
- execvp() instead of execv() is used, so you don't have to specify the
  full PATH (useful for nixos)

CMakeLists.txt

@@ -55,9 +55,6 @@ if(${Boost_VERSION} GREATER 104999)
 	add_definitions(-DBOOST_FILESYSTEM_VERSION=3)
 endif()
 
-# FIND POPT
-find_package(popt REQUIRED)
-
 ###### Database ######
 
 # FIND SQLITE3

backends/libpurple/main.cpp

@@ -263,10 +263,6 @@ class SpectrumNetworkPlugin : public NetworkPlugin {
 	void getProtocolAndName(const std::string &legacyName, std::string &name, std::string &protocol) {
 		name = legacyName;
 		protocol = CONFIG_STRING(config, "service.protocol");
-		if (protocol == "any") {
-			protocol = name.substr(0, name.find("."));
-			name = name.substr(name.find(".") + 1);
-		}
 	}
 
 	void setDefaultAvatar(PurpleAccount *account, const std::string &legacyName) {

cmake_modules/Findpopt.cmake

@@ -1,10 +0,0 @@
-FIND_LIBRARY(POPT_LIBRARY NAMES popt)
-FIND_PATH(POPT_INCLUDE_DIR NAMES "popt.h")
-
-
-if( POPT_LIBRARY AND POPT_INCLUDE_DIR )
-    message( STATUS "Found popt: ${POPT_LIBRARY}, ${POPT_INCLUDE_DIR}")
-    set( POPT_FOUND 1 )
-else( POPT_LIBRARY AND POPT_INCLUDE_DIR )
-    message( STATUS "Could NOT find popt" )
-endif( POPT_LIBRARY AND POPT_INCLUDE_DIR )

include/transport/Config.h

@@ -123,7 +123,8 @@ class Config {
 
 	SectionValuesCont getSectionValues(const std::string &sectionName);
 
-	std::string getCommandLineArgs() const;
+	int getArgc();
+	char **getArgv();
 
 	/// Returns path to config file from which data were loaded.
 	const std::string &getConfigFile() {

include/transport/NetworkPluginServer.h

@@ -105,6 +105,7 @@ class NetworkPluginServer : Swift::XMPPParserClient {
 	void handleMessageReceived(NetworkConversation *conv, std::shared_ptr<Swift::Message> &message);
 
   public:
+	unsigned long spawnBackend(const char *backend_id);
 	void handleNewClientConnection(std::shared_ptr<Swift::Connection> c);
 	void handleSessionFinished(Backend *c);
 	void handlePongReceived(Backend *c);

libtransport/Config.cpp

@@ -330,16 +330,12 @@ Config::SectionValuesCont Config::getSectionValues(const std::string &sectionNam
 	return sectionValues;
 }
 
-std::string Config::getCommandLineArgs() const {
-	std::ostringstream commandLineArgs;
-
-	// Return the command-line arguments that were passed to us originally (but
-	// remove the initial .exe part)
-	for (int i = 1; i < m_argc; ++i) {
-		commandLineArgs << "\"" << m_argv[i] << "\" ";
-	}
+int Config::getArgc() {
+	return m_argc;
+}
 
-	return commandLineArgs.str();
+char **Config::getArgv() {
+	return m_argv;
 }
 
 void Config::updateBackendConfig(const std::string &backendConfig) {

libtransport/NetworkPluginServer.cpp

@@ -58,7 +58,6 @@
 #include <signal.h>
 #include <sys/types.h>
 
-#include "popt.h"
 #include "sys/signal.h"
 #include "sys/wait.h"
 
@@ -134,49 +133,6 @@ class NetworkFactory : public Factory {
 	wrap.SerializeToString(&MESSAGE);
 
 // Executes new backend
-static unsigned long exec_(const std::string &exePath, const char *host, const char *port, const char *log_id,
-                           const char *cmdlineArgs) {
-	// BACKEND_ID is replaced with unique ID. The ID is increasing for every
-	// backend.
-	std::string finalExePath =
-	    boost::replace_all_copy(exePath, "BACKEND_ID", boost::lexical_cast<std::string>(backend_id++));
-
-	// Add host and port.
-	finalExePath +=
-	    std::string(" --host ") + host + " --port " + port + " --service.backend_id=" + log_id + " " + cmdlineArgs;
-	LOG4CXX_INFO(logger, "Starting new backend " << finalExePath);
-
-	// Create array of char * from string using -lpopt library
-	char *p = (char *)malloc(finalExePath.size() + 1);
-	strcpy(p, finalExePath.c_str());
-	int argc;
-	char **argv;
-	poptParseArgvString(p, &argc, (const char ***)&argv);
-
-	// fork and exec
-	pid_t pid = fork();
-	if (pid == 0) {
-		setsid();
-		// close all files
-		int maxfd = sysconf(_SC_OPEN_MAX);
-		for (int fd = 3; fd < maxfd; fd++) {
-			close(fd);
-		}
-		// child process
-		errno = 0;
-		int ret = execv(argv[0], argv);
-		if (ret == -1) {
-			exit(errno);
-		}
-		exit(0);
-	} else if (pid < 0) {
-		LOG4CXX_ERROR(logger, "Fork failed");
-	}
-	free(p);
-
-	return (unsigned long)pid;
-}
-
 static void SigCatcher(int n) {
 	pid_t result;
 	int status;
@@ -304,6 +260,46 @@ NetworkPluginServer::~NetworkPluginServer() {
 	// 	delete m_rosterResponder;
 	// 	delete m_blockResponder;
 }
+unsigned long NetworkPluginServer::spawnBackend(const char *backend_id) {
+	std::string binaryPath = CONFIG_STRING(m_config, "service.backend");
+	std::vector<const char *> binaryArgs = {binaryPath.c_str()};
+	binaryArgs.push_back("--host");
+	binaryArgs.push_back(CONFIG_STRING(m_config, "service.backend_host").c_str());
+	binaryArgs.push_back("--port");
+	binaryArgs.push_back(CONFIG_STRING(m_config, "service.backend_port").c_str());
+	char **origArgv = m_config->getArgv();
+	for (int i = 1; i < m_config->getArgc(); i++) {
+		binaryArgs.push_back(origArgv[i]);
+	}
+
+	std::string debugBackendCommand = "";
+	for (const char *thing : binaryArgs) {
+		debugBackendCommand += thing;
+		debugBackendCommand += " ";
+	}
+
+	LOG4CXX_INFO(logger, "Executing: " << debugBackendCommand);
+
+  binaryArgs.push_back(NULL); // indicate end of array
+	const char **argv = binaryArgs.data();
+
+	// fork and exec
+	pid_t pid = fork();
+
+	if (pid == 0) {
+		setsid();
+		// child process
+		int ret = execvp(argv[0], (char *const *)argv);
+		if (ret == -1) {
+      perror("execvp");
+			exit(errno);
+		}
+	} else if (pid < 0) {
+		LOG4CXX_ERROR(logger, "Fork failed");
+	}
+
+	return (unsigned long)pid;
+}
 
 void NetworkPluginServer::start() {
 	m_server->start();
@@ -312,9 +308,7 @@ void NetworkPluginServer::start() {
 	                                          << CONFIG_STRING(m_config, "service.backend_port"));
 
 	while (true) {
-		unsigned long pid =
-		    exec_(CONFIG_STRING(m_config, "service.backend"), CONFIG_STRING(m_config, "service.backend_host").c_str(),
-		          CONFIG_STRING(m_config, "service.backend_port").c_str(), "1", m_config->getCommandLineArgs().c_str());
+		unsigned long pid = spawnBackend("1");
 		LOG4CXX_INFO(logger, "Tried to spawn first backend with pid " << pid);
 		LOG4CXX_INFO(logger, "Backend should now connect to Spectrum2 instance. Spectrum2 "
 		                     "won't accept any connection before backend connects");
@@ -2016,7 +2010,6 @@ void NetworkPluginServer::handlePIDTerminated(unsigned long pid) {
 	}
 }
 
-
 static int sig_block_count = 0;
 static sigset_t block_mask;
 
@@ -2056,7 +2049,6 @@ static void __unblock_signals(void) {
 	}
 }
 
-
 NetworkPluginServer::Backend *NetworkPluginServer::getFreeClient(bool acceptUsers, bool longRun, bool check) {
 	NetworkPluginServer::Backend *c = NULL;
 
@@ -2107,10 +2099,7 @@ NetworkPluginServer::Backend *NetworkPluginServer::getFreeClient(bool acceptUser
 		} else {
 			log_id = boost::lexical_cast<std::string>(log_id_it - m_pids.begin() + 1);
 		}
-		unsigned long pid =
-		    exec_(CONFIG_STRING(m_config, "service.backend"), CONFIG_STRING(m_config, "service.backend_host").c_str(),
-		          CONFIG_STRING(m_config, "service.backend_port").c_str(), log_id.c_str(),
-		          m_config->getCommandLineArgs().c_str());
+		unsigned long pid = spawnBackend(log_id.c_str());
 		if (log_id_it == m_pids.end()) {
 			m_pids.push_back(pid);
 		} else {

nix/default.nix

@@ -23,5 +23,5 @@ stdenv.mkDerivation {
     (path: type: !(lib.strings.hasSuffix (baseNameOf path) "nix") && filter path type)
     ../.;
   nativeBuildInputs = [ cmake pkg-config ];
-  buildInputs = [ pkgs-eta.swiften zlib expat boost pqxx pqxx.pkgconfig postgresql.lib libpurple libev sqlite log4cxx glib pcre boost protobuf curl jsoncpp popt ];
+  buildInputs = [ pkgs-eta.swiften zlib expat boost pqxx pqxx.pkgconfig postgresql.lib libpurple libev sqlite log4cxx glib pcre boost protobuf curl jsoncpp ];
 }