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/// inotify cron daemon main file
/**
* \file icd-main.cpp
*
* inotify cron system
*
* Copyright (C) 2006 Lukas Jelinek, <lukas@aiken.cz>
*
* This program is free software; you can use it, redistribute
* it and/or modify it under the terms of the GNU General Public
* License, version 2 (see LICENSE-GPL).
*
*/
#include <map>
#include <signal.h>
#include <wait.h>
#include <pwd.h>
#include <dirent.h>
#include <syslog.h>
#include <errno.h>
#include <sys/poll.h>
#include "inotify-cxx.h"
#include "incrontab.h"
#include "usertable.h"
/// Daemon yes/no
#define DAEMON true
/// Application name
#define INCRON_APP_NAME "incrond"
/// Logging options (console as fallback, log PID)
#define INCRON_LOG_OPTS (LOG_CONS | LOG_PID)
/// Logging facility (use CRON)
#define INCRON_LOG_FACIL LOG_CRON
/// User name to user table mapping definition
typedef std::map<std::string, UserTable*> SUT_MAP;
/// User name to user table mapping table
SUT_MAP g_ut;
/// Finish program yes/no
volatile bool g_fFinish = false;
/// Handles a signal.
/**
* For SIGTERM and SIGINT it sets the program finish variable.
*
* \param[in] signo signal number
*/
void on_signal(int signo)
{
if (signo == SIGTERM || signo == SIGINT)
g_fFinish = true;
}
/// Checks whether an user exists and has permission to use incron.
/**
* It searches for the given user name in the user database.
* If it failes it returns 'false'. Otherwise it checks
* permission files for this user (see InCronTab::CheckUser()).
*
* \param[in] user user name
* \return true = user has permission to use incron, false = otherwise
*
* \sa InCronTab::CheckUser()
*/
bool check_user(const char* user)
{
struct passwd* pw = getpwnam(user);
if (pw == NULL)
return false;
return InCronTab::CheckUser(user);
}
/// Attempts to load all user incron tables.
/**
* Loaded tables are registered for processing events.
*
* \param[in] pIn inotify object
* \param[in] pEd inotify event dispatcher
*
* \throw InotifyException thrown if base table directory cannot be read
*/
void load_tables(Inotify* pIn, EventDispatcher* pEd) throw (InotifyException)
{
DIR* d = opendir(INCRON_TABLE_BASE);
if (d == NULL)
throw InotifyException("cannot open table directory", errno);
syslog(LOG_NOTICE, "loading user tables");
struct dirent* pDe = NULL;
while ((pDe = readdir(d)) != NULL) {
std::string un(pDe->d_name);
if (pDe->d_type == DT_REG && un != "." && un != "..") {
if (check_user(pDe->d_name)) {
syslog(LOG_INFO, "loading table for user %s", pDe->d_name);
UserTable* pUt = new UserTable(pIn, pEd, un);
g_ut.insert(SUT_MAP::value_type(un, pUt));
pUt->Load();
}
else {
syslog(LOG_WARNING, "table for invalid user %s found (ignored)", pDe->d_name);
}
}
}
closedir(d);
}
/// Main application function.
/**
* \param[in] argc argument count
* \param[in] argv argument array
* \return 0 on success, 1 on error
*
* \attention In daemon mode, it finishes immediately.
*/
int main(int argc, char** argv)
{
openlog(INCRON_APP_NAME, INCRON_LOG_OPTS, INCRON_LOG_FACIL);
syslog(LOG_NOTICE, "starting service");
try {
Inotify in;
in.SetNonBlock(true);
EventDispatcher ed(&in);
try {
load_tables(&in, &ed);
} catch (InotifyException e) {
int err = e.GetErrorNumber();
syslog(LOG_CRIT, "%s: (%i) %s", e.GetMessage().c_str(), err, strerror(err));
syslog(LOG_NOTICE, "stopping service");
closelog();
return 1;
}
signal(SIGTERM, on_signal);
signal(SIGINT, on_signal);
signal(SIGCHLD, on_signal);
if (DAEMON)
daemon(0, 0);
uint32_t wm = IN_CLOSE_WRITE | IN_DELETE | IN_MOVE | IN_DELETE_SELF | IN_UNMOUNT;
InotifyWatch watch(INCRON_TABLE_BASE, wm);
in.Add(watch);
syslog(LOG_NOTICE, "ready to process filesystem events");
InotifyEvent e;
struct pollfd pfd;
pfd.fd = in.GetDescriptor();
pfd.events = (short) POLLIN;
pfd.revents = (short) 0;
while (!g_fFinish) {
int res = poll(&pfd, 1, -1);
if (res > 0) {
in.WaitForEvents(true);
}
else if (res < 0) {
if (errno != EINTR)
throw InotifyException("polling failed", errno, NULL);
}
UserTable::FinishDone();
while (in.GetEvent(e)) {
if (e.GetWatch() == &watch) {
if (e.IsType(IN_DELETE_SELF) || e.IsType(IN_UNMOUNT)) {
syslog(LOG_CRIT, "base directory destroyed, exitting");
g_fFinish = true;
}
else if (!e.GetName().empty()) {
SUT_MAP::iterator it = g_ut.find(e.GetName());
if (it != g_ut.end()) {
UserTable* pUt = (*it).second;
if (e.IsType(IN_CLOSE_WRITE) || e.IsType(IN_MOVED_TO)) {
syslog(LOG_INFO, "table for user %s changed, reloading", e.GetName().c_str());
pUt->Dispose();
pUt->Load();
}
else if (e.IsType(IN_MOVED_FROM) || e.IsType(IN_DELETE)) {
syslog(LOG_INFO, "table for user %s destroyed, removing", e.GetName().c_str());
delete pUt;
g_ut.erase(it);
}
}
else if (e.IsType(IN_CLOSE_WRITE) || e.IsType(IN_MOVED_TO)) {
if (check_user(e.GetName().c_str())) {
syslog(LOG_INFO, "table for user %s created, loading", e.GetName().c_str());
UserTable* pUt = new UserTable(&in, &ed, e.GetName());
g_ut.insert(SUT_MAP::value_type(e.GetName(), pUt));
pUt->Load();
}
}
}
}
else {
ed.DispatchEvent(e);
}
}
}
} catch (InotifyException e) {
int err = e.GetErrorNumber();
syslog(LOG_CRIT, "*** unhandled exception occurred ***");
syslog(LOG_CRIT, " %s", e.GetMessage().c_str());
syslog(LOG_CRIT, " error: (%i) %s", err, strerror(err));
}
syslog(LOG_NOTICE, "stopping service");
closelog();
return 0;
}