winix can drop privileges now (if started as the root)

added parameters to the config:
 user (string)
 group (string)
 additional_groups (bool)



git-svn-id: svn://ttmath.org/publicrep/winix/trunk@668 e52654a7-88a9-db11-a3e9-0013d4bc506e

core/app.cpp

@@ -7,6 +7,11 @@
  * 
  */
  
+#include <sys/types.h>
+#include <pwd.h>
+#include <grp.h>
+#include <unistd.h>
+
 #include "app.h"
 #include "plugin.h"
 #include "misc.h"
@@ -138,7 +143,7 @@ bool App::Init()
 	db.LogQueries(config.log_db_query);
 
 	if( !CreateFCGISocket() )
-		return false;
+		return false; // !! dodac logsave do logow
 
 	request.Clear();
 	compress.Init();
@@ -148,7 +153,7 @@ bool App::Init()
 	// !! teraz mamy dwa katalogi z templetami
 	// !! o co chodzilo?
 	if( !notify.Init() )
-		return false;
+		return false; // !! dodac logsave do logow
 
 	// call this after system.Init() (mount points identificators should be created)
 	templates_notify.SetMountTypes(	system.mounts.MountTypeCms(),
@@ -714,3 +719,211 @@ Error status     = request.status;
 		FilterCompressSend(compressing, source);
 	}
 }
+
+
+void App::LogUser(const char * msg, uid_t id)
+{
+	log << log3 << msg << " ";
+
+	passwd * p = getpwuid(id);
+	
+	if( p )
+		log << p->pw_name;
+	else
+		log << id;
+
+	log << logend;
+}
+
+
+void App::LogGroup(const char * msg, gid_t id, bool put_logend)
+{
+	log << log3 << msg << " ";
+
+	group * g = getgrgid(id);
+
+	if( g )
+		log << g->gr_name;
+	else
+		log << (int)id;
+
+	if( put_logend )
+		log << logend;
+}
+
+
+void App::LogUsers()
+{
+uid_t eid, rid;
+	
+	eid = geteuid();
+	rid = getuid();
+
+	if( eid == rid )
+	{
+		LogUser("App: effective/real user:", eid);
+	}
+	else
+	{
+		LogUser("App: effective user:", eid);
+		LogUser("App: real user:",      rid);
+	}
+}
+
+
+
+void App::LogEffectiveGroups(std::vector<gid_t> & tab)
+{
+	log << log3 << "App: effective groups:";
+
+	for(size_t i=0 ; i<tab.size() ; ++i)
+	{
+		bool was_printed = false;
+
+		for(size_t x=0 ; x<i ; ++x)
+		{
+			if( tab[i] == tab[x] )
+			{
+				was_printed = true;
+				break;
+			}
+		}
+
+		if( !was_printed )
+			LogGroup("", tab[i], false);
+	}
+
+	log << logend;
+}
+
+
+void App::LogGroups()
+{
+std::vector<gid_t> tab;
+gid_t rgid;
+int len;
+
+	rgid = getgid(); 
+	len  = getgroups(0, 0);
+
+	if( len <= 0 )
+	{
+		log << log3 << "App: I can't read how many groups there are" << logend;
+		return;
+	}
+
+	tab.resize(len);
+	len = getgroups(len, &(tab[0]));
+
+	if( len == -1 )
+	{
+		log << log3 << "App: I can't read groups" << logend;
+		return;
+	}
+
+	if( len == 1 && rgid == tab[0] )
+	{
+		LogGroup("App: effective/real group:", rgid);
+	}
+	else
+	{
+		tab.resize(len);
+		LogEffectiveGroups(tab);
+		LogGroup("App: real group:", rgid);
+	}
+}
+
+
+void App::LogUserGroups()
+{
+	LogUsers();
+	LogGroups();
+}
+
+
+
+bool App::DropPrivileges(const std::string & user, uid_t uid, gid_t gid, bool additional_groups)
+{
+	if( additional_groups )
+	{
+		if( initgroups(user.c_str(), gid) < 0 )
+		{
+			log << log1 << "App: I can't init groups for user: " << user << logend << logsave;
+			return false;
+		}
+	}
+	else
+	{
+		if( setgroups(1, &gid) < 0 )
+		{
+			log << log1 << "App: I can't init groups for user: " << user << logend << logsave;
+			return false;
+		}
+	}
+
+	// for setting real and saved gid too
+	if( setgid(gid) )
+	{
+		log << log1 << "App: I can't change real and saved gid" << logend << logsave;
+		return false;
+	}
+
+	if( setuid(uid) < 0 )
+	{	
+		log << log1 << "App: I can't drop privileges to user: " << user
+			<< " (uid:" << uid << ")" << logend << logsave;
+		return false;
+	}
+
+	if( getuid()==0 || geteuid()==0 )
+	{
+		log << log1 << "App: sorry, for security reasons you should not run me as the root" << logend << logsave;
+		return false;
+	}
+
+return true;
+}
+
+
+bool App::DropPrivileges()
+{
+	if( getuid()!=0 && geteuid()!=0 )
+		return true;
+
+	log << log2 << "App: dropping privileges" << logend;
+
+	if( config.user.empty() )
+	{
+		log << log1 << "App: you should specify user name in the config file "
+					<< "to which I have to drop privileges" << logend << logsave;
+		return false;
+	}
+
+	if( config.group.empty() )
+	{
+		log << log1 << "App: you should specify group name in the config file "
+					<< "to which I have to drop privileges" << logend << logsave;
+		return false;
+	}
+
+	passwd * p = getpwnam(config.user.c_str());
+	group * g  = getgrnam(config.group.c_str());
+
+	if( !p )
+	{	
+		log << log1 << "App: there is no such a user as: \"" << config.user << "\"" << logend << logsave;
+		return false;
+	}
+
+	if( !g )
+	{	
+		log << log1 << "App: there is no such a group as: \"" << config.group << "\"" << logend << logsave;
+		return false;
+	}
+
+	if( !DropPrivileges(config.user, p->pw_uid, g->gr_gid, config.additional_groups) )
+		return false;
+
+return true;
+}
+

core/app.h

@@ -50,7 +50,8 @@ public:
 	bool Init();
 	void Start();
 	void Close();
-
+	bool DropPrivileges();
+	void LogUserGroups();
 
 
 	// configuration read from a config file
@@ -150,6 +151,12 @@ private:
 	bool IsCompressionAllowed(const std::string & source);
 	bool CanSendContent(Header header);
 
+	void LogUser(const char * msg, uid_t id);
+	void LogGroup(const char * msg, gid_t id, bool put_logend = true);
+	void LogUsers();
+	void LogEffectiveGroups(std::vector<gid_t> & tab);
+	void LogGroups();
+	bool DropPrivileges(const std::string & user, uid_t uid, gid_t gid, bool additional_groups);
 
 	// !! dodac do session managera?
 	time_t last_sessions_save;

core/config.cpp

@@ -89,6 +89,10 @@ bool Config::ReadConfig(bool errors_to_stdout_, bool stdout_is_closed)
 
 void Config::AssignValues(bool stdout_is_closed)
 {
+	user  = Text("user");
+	group = Text("group");
+	additional_groups = Bool("additional_groups", true);
+
 	log_file          = Text("log_file");
 	log_notify_file   = Text("log_notify_file");
 	log_delimiter     = Text("log_delimiter", "---------------------------------------------------------------------------------");

core/config.h

@@ -24,6 +24,20 @@ public:
 	// name of the config file (full path can be)
 	std::string config_file;
 
+	// system user name (to which drop privileges)
+	// used only if winix is started as the root
+	std::string user;
+
+	// system group name (to which drop privileges)
+	// used only if winix is started as the root
+	std::string group;
+
+	// setting additional effective groups from /etc/group
+	// by using initgroups()
+	// used only if winix is started as the root
+	// default: true
+	bool additional_groups;
+
 	// log file name, log file name for notifications (sending emails, etc)
 	std::string log_file, log_notify_file;
 	

core/log.cpp

@@ -19,6 +19,7 @@ Log::Log()
 	item          = 0;
 	item_save     = 1;
 	lines         = 0;
+	log_file_open = false;
 }
 
 
@@ -29,14 +30,18 @@ void Log::Init(int log_l, const std::string & log_f, bool log_std, int log_reque
 	log_stdout    = log_std;
 	item_save     = log_request;
 
-	OpenFile();
+	// don't open the file here
+	// because it would be created with the root as an owner
 }
 
 
 void Log::OpenFile()
 {
 	if( !log_file.empty() )
+	{
 		file.open( log_file.c_str(), std::ios_base::out | std::ios_base::app );
+		log_file_open = true;
+	}
 }
 
 
@@ -216,7 +221,7 @@ void Log::SaveLog()
 	if( log_file.empty() )
 		return;
 
-	if( !file )
+	if( !log_file_open || !file )
 	{
 		file.close();
 		file.clear();
@@ -227,7 +232,8 @@ void Log::SaveLog()
 			return;
 	}
 
-	file << source << std::endl;
+	file << source;
+	file.flush();
 }
 
 

core/log.h

@@ -25,16 +25,6 @@ enum Manipulators { logsave, logsavenow, logend, log1, log2, log3 };
 
 class Log
 {
-std::ostringstream buffer;
-int log_level, current_level;
-int item, item_save;
-std::string log_file;
-bool log_stdout;
-std::ofstream file;
-int lines;
-
-	void OpenFile();
-
 public:
 	
 	Log();
@@ -54,8 +44,20 @@ public:
 	Log & operator<<(Manipulators m);
 	
 	void SystemErr(int err);
-
 	void SaveLog();
+
+private:
+	std::ostringstream buffer;
+	int log_level, current_level;
+	int item, item_save;
+	std::string log_file;
+	bool log_stdout;
+	std::ofstream file;
+	int lines;
+	bool log_file_open;
+
+	void OpenFile();
+
 };
 
 

main/main.cpp

@@ -44,7 +44,6 @@ void signal_term(int)
 
 
 
-
 void print_syntax()
 {
 	std::cout << "Syntax:" << std::endl;	
@@ -86,6 +85,11 @@ int main(int argv, char ** argc)
 	log.Init(app.config.log_level, app.config.log_file, app.config.log_stdout, app.config.log_request);
 	nlog.Init(app.config.log_level, app.config.log_notify_file, false, 1);
 
+	if( !app.DropPrivileges() )
+		return 3;
+
+	app.LogUserGroups();
+
 	// app.config.base_server can be changed (stripped from 'http://' or a last slash)
 	// it is done when the config is read
 	log << log3 << "base_server: " << app.config.base_server << logend;