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/// inotify cron daemon user tables implementation

/**

 * \file usertable.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 <pwd.h>

#include <syslog.h>

#include <errno.h>

#include <sys/wait.h>

#include "usertable.h"

PROC_LIST UserTable::s_procList;

void on_proc_done(InotifyWatch* pW)

{

  pW->SetEnabled(true);

}

EventDispatcher::EventDispatcher(Inotify* pIn)

{

 m_pIn = pIn;

}

void EventDispatcher::DispatchEvent(InotifyEvent& rEvt)

{

  if (m_pIn == NULL)

    return;

  InotifyWatch* pW = rEvt.GetWatch();

  if (pW == NULL)

    return;

  UserTable* pT = FindTable(pW);

  if (pT == NULL)

    return;

  pT->OnEvent(rEvt);

}

void EventDispatcher::Register(InotifyWatch* pWatch, UserTable* pTab)

{

  if (pWatch != NULL && pTab != NULL)

    m_maps.insert(IWUT_MAP::value_type(pWatch, pTab));

}

void EventDispatcher::Unregister(InotifyWatch* pWatch)

{

  IWUT_MAP::iterator it = m_maps.find(pWatch);

  if (it == m_maps.end())

    return;

  m_maps.erase(it);

}

void EventDispatcher::UnregisterAll(UserTable* pTab)

{

  IWUT_MAP::iterator it = m_maps.begin();

  while (it != m_maps.end()) {

    if ((*it).second == pTab) {

      IWUT_MAP::iterator it2 = it;

      it++;

      m_maps.erase(it2);

    }

    else {

      it++;

    }

  }

}

UserTable* EventDispatcher::FindTable(InotifyWatch* pW)

{

  IWUT_MAP::iterator it = m_maps.find(pW);

  if (it == m_maps.end())

    return NULL;

  return (*it).second;

}

UserTable::UserTable(Inotify* pIn, EventDispatcher* pEd, const std::string& rUser)

: m_user(rUser)

{

  m_pIn = pIn;

  m_pEd = pEd;

}

UserTable::~UserTable()

{

  Dispose();

}

void UserTable::Load()

{

  m_tab.Load(InCronTab::GetUserTablePath(m_user));

  int cnt = m_tab.GetCount();

  for (int i=0; i<cnt; i++) {

    InCronTabEntry& rE = m_tab.GetEntry(i);

    InotifyWatch* pW = new InotifyWatch(rE.GetPath(), rE.GetMask());

    try {

      m_pIn->Add(pW);

      m_pEd->Register(pW, this);

      m_map.insert(IWCE_MAP::value_type(pW, &rE));

    } catch (InotifyException e) {

      syslog(LOG_ERR, "cannot create watch for user %s", m_user.c_str());

      delete pW;

    }

  }

}

void UserTable::Dispose()

{

  IWCE_MAP::iterator it = m_map.begin();

  while (it != m_map.end()) {

    InotifyWatch* pW = (*it).first;

    m_pEd->Unregister(pW);

    m_pIn->Remove(pW);

    delete pW;

    it++;

  }

  m_map.clear();

}

void UserTable::OnEvent(InotifyEvent& rEvt)

{

  InotifyWatch* pW = rEvt.GetWatch();

  InCronTabEntry* pE = FindEntry(pW);

  if (pE == NULL)

    return;

  std::string cmd;

  const std::string& cs = pE->GetCmd();

  size_t pos = 0;

  size_t oldpos = 0;

  size_t len = cs.length();

  while ((pos = cs.find('$', oldpos)) != std::string::npos) {

    if (pos < len - 1) {

      size_t px = pos + 1;

      if (cs[px] == '$') {

        cmd.append(cs.substr(oldpos, pos-oldpos+1));

        oldpos = pos + 2;

      }

      else if (cs[px] == '@') {

        cmd.append(cs.substr(oldpos, pos-oldpos));

        cmd.append(pW->GetPath());

        oldpos = pos + 2;

      }

      else if (cs[px] == '#') {

        cmd.append(cs.substr(oldpos, pos-oldpos));

        cmd.append(rEvt.GetName());

        oldpos = pos + 2;

      }

      else {

        cmd.append(cs.substr(oldpos, pos-oldpos));

        oldpos = pos + 1;

      }

    }

    else {

      cmd.append(cs.substr(oldpos, pos-oldpos));

      oldpos = pos + 1;

    }

  }    

  cmd.append(cs.substr(oldpos));

  int argc;

  char** argv;

  if (!PrepareArgs(cmd, argc, argv)) {

    syslog(LOG_ERR, "cannot prepare command arguments");

    return;

  }

  syslog(LOG_INFO, "(%s) CMD (%s)", m_user.c_str(), cmd.c_str());

  if (pE->IsNoLoop())

    pW->SetEnabled(false);

  ProcData_t pd;

  pd.pid = fork();

  if (pd.pid == 0) {

    struct passwd* pwd = getpwnam(m_user.c_str());

    if (    pwd == NULL                 // user not found

        ||  setuid(pwd->pw_uid) != 0    // setting UID failed

        ||  execvp(argv[0], argv) != 0) // exec failed

    {

      _exit(1);

    }

  }

  else if (pd.pid > 0) {

    if (pE->IsNoLoop()) {

      pd.onDone = on_proc_done;

      pd.pWatch = pW;

    }

    else {

      pd.onDone = NULL;

      pd.pWatch = NULL;

    }

    s_procList.push_back(pd);

  }

  else {

    if (pE->IsNoLoop())

      pW->SetEnabled(true);

    syslog(LOG_ERR, "cannot fork process: %s", strerror(errno));

  }

  CleanupArgs(argc, argv);

}

InCronTabEntry* UserTable::FindEntry(InotifyWatch* pWatch)

{

  IWCE_MAP::iterator it = m_map.find(pWatch);

  if (it == m_map.end())

    return NULL;

  return (*it).second;

}

bool UserTable::PrepareArgs(const std::string& rCmd, int& argc, char**& argv)

{

  if (rCmd.empty())

    return false;

  StringTokenizer tok(rCmd, ' ');

  std::deque<std::string> args;

  while (tok.HasMoreTokens()) {

    args.push_back(tok.GetNextToken());

  }

  if (args.empty())

    return false;

  argc = (int) args.size();

  argv = new char*[argc+1];

  argv[argc] = NULL;

  for (int i=0; i<argc; i++) {

    const std::string& s = args[i];

    size_t len = s.length();

    argv[i] = new char[len+1];

    strcpy(argv[i], s.c_str());

  }

  return true;

}

void UserTable::CleanupArgs(int argc, char** argv)

{

  for (int i=0; i<argc; i++) {

    delete[] argv[i];

  }

  delete[] argv;

}

void UserTable::FinishDone()

{

  PROC_LIST::iterator it = s_procList.begin();

  while (it != s_procList.end()) {

    ProcData_t& pd = *it;

    int status = 0;

    int res = waitpid(pd.pid, &status, WNOHANG);

    if (res == pd.pid && (WIFEXITED(status) || WIFSIGNALED(status))) {

      if (pd.onDone != NULL)

        (*pd.onDone)(pd.pWatch);

      it = s_procList.erase(it);

    }

    else {

      it++;

    }

  }  

}