path: root/src/luaclient.c

/*
 *  rhctl
 *
 *  Copyright (C) 2009-2015 Christian Pointner <equinox@helsinki.at>
 *
 *  This file is part of rhctl.
 *
 *  rhctl 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, either version 3 of the License, or
 *  any later version.
 *
 *  rhctl 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 rhctl. If not, see <http://www.gnu.org/licenses/>.
 */

#include "datatypes.h"

#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <errno.h>

#include <lua.h>
#include <lualib.h>
#include <lauxlib.h>

#include "l_log.h"
#include "l_sig_handler.h"
#include "l_cmd.h"

#include "log.h"
#include "options.h"

#include "daemon.h"
#include "utils.h"


#define LUA_MAIN_LOOP_FUNC "main_loop"

#if LUA_VERSION_NUM > 501
static const luaL_Reg luaclient_lualibs[] = {
  {"_G", luaopen_base},
  {LUA_LOADLIBNAME, luaopen_package},
  {LUA_TABLIBNAME, luaopen_table},
  {LUA_STRLIBNAME, luaopen_string},
  {LUA_MATHLIBNAME, luaopen_math},
  {LUA_IOLIBNAME, luaopen_io},
  {LUA_OSLIBNAME, luaopen_os},
  {LUA_BITLIBNAME, luaopen_bit32},
  {LUA_LOGLIBNAME, luaopen_log},
  {LUA_SIGNALLIBNAME, luaopen_signal},
  {LUA_CMDLIBNAME, luaopen_cmd},
  {NULL, NULL}
};
#else
static const luaL_Reg luaclient_lualibs[] = {
  {"", luaopen_base},
  {LUA_LOADLIBNAME, luaopen_package},
  {LUA_TABLIBNAME, luaopen_table},
  {LUA_STRLIBNAME, luaopen_string},
  {LUA_MATHLIBNAME, luaopen_math},
  {LUA_IOLIBNAME, luaopen_io},
  {LUA_OSLIBNAME, luaopen_os},
  {LUA_LOGLIBNAME, luaopen_log},
  {LUA_SIGNALLIBNAME, luaopen_signal},
  {LUA_CMDLIBNAME, luaopen_cmd},
  {NULL, NULL}
};
#endif

int init_main_loop(lua_State *L, const char* filename)
{
  const luaL_Reg *lib = luaclient_lualibs;

#if LUA_VERSION_NUM > 501
  for (; lib->func; lib++) {
    luaL_requiref(L, lib->name, lib->func, 1);
    lua_pop(L, 1);
  }
#else
  for (; lib->func; lib++) {
    lua_pushcfunction(L, lib->func);
    lua_pushstring(L, lib->name);
    lua_call(L, 1, 0);
  }
#endif

  int ret = luaL_loadfile(L, filename);
  if(ret) {
    const char* err_str = luaL_checkstring(L, -1);
    switch(ret) {
    case LUA_ERRSYNTAX: log_printf(ERROR, "luaL_loadfile(%s) syntax error: %s", filename, err_str); break;
    case LUA_ERRMEM: log_printf(ERROR, "luaL_loadfile(%s) malloc error: %s", filename, err_str); break;
    case LUA_ERRFILE: log_printf(ERROR, "luaL_loadfile(%s) file access error: %s", filename, err_str); break;
    default: log_printf(ERROR, "luaL_loadfile(%s) unknown error: %s", filename, err_str); break;
    }
    return -1;
  }

  ret = lua_pcall(L, 0, 0, 0);
  if(ret) {
    const char* err_str = luaL_checkstring(L, -1);
    switch(ret) {
    case LUA_ERRRUN: log_printf(ERROR, "lua_pcall() runtime error: %s", err_str); break;
    case LUA_ERRMEM: log_printf(ERROR, "lua_pcall() malloc error: %s", err_str); break;
    case LUA_ERRERR: log_printf(ERROR, "lua_pcall() error at error handler function: %s", err_str); break;
    }
    return -1;
  }

  return 0;
}

int call_main_loop(lua_State* L, int cmd_fd, options_t* opt)
{
  lua_getglobal(L, LUA_MAIN_LOOP_FUNC);
  if(!lua_isfunction(L, -1)) {
    log_printf(ERROR, "there is no function '%s' inside the loaded file", LUA_MAIN_LOOP_FUNC);
    return -1;
  };

  options_lua_push(opt, L);

  int ret = lua_pcall(L, 1, LUA_MULTRET, 0);
  if(ret) {
    const char* err_str = luaL_checkstring(L, -1);
    switch(ret) {
    case LUA_ERRRUN: log_printf(ERROR, "lua_pcall(%s) runtime error: %s", LUA_MAIN_LOOP_FUNC, err_str); break;
    case LUA_ERRMEM: log_printf(ERROR, "lua_pcall(%s) malloc error: %s", LUA_MAIN_LOOP_FUNC, err_str); break;
    case LUA_ERRERR: log_printf(ERROR, "lua_pcall(%s) error at error handler function: %s", LUA_MAIN_LOOP_FUNC, err_str); break;
    }
    return -1;
  }

  int n = lua_gettop(L);
  log_printf(DEBUG, "%s returned %d values", LUA_MAIN_LOOP_FUNC, n);
  int i;
  for (i = 1; i <= n; i++)
    log_printf(DEBUG, "return value [%d] = '%s'", i, luaL_checkstring(L, i));

  ret = lua_tointeger(L, 1);
  return ret;
}

int main_loop(int cmd_fd, options_t* opt)
{
  lua_State *L;
  L = luaL_newstate();
  if(!L) {
    log_printf(ERROR, "error creating lua state");
    return -1;
  }

  int ret = init_main_loop(L, opt->lua_file_);
  if(!ret)
    ret = call_main_loop(L, cmd_fd, opt);

  lua_close(L);
  return ret;
}

int main(int argc, char* argv[])
{
  log_init();

  options_t opt;
  int ret = options_parse(&opt, argc, argv);
  if(ret) {
    if(ret > 0) {
      fprintf(stderr, "syntax error near: %s\n\n", argv[ret]);
    }
    if(ret == -2) {
      fprintf(stderr, "memory error on options_parse, exiting\n");
    }

    if(ret != -2)
      options_print_usage();

    options_clear(&opt);
    log_close();
    exit(ret);
  }
  string_list_element_t* tmp = opt.log_targets_.first_;
  if(!tmp) {
    log_add_target("syslog:3,luaclient,daemon");
  }
  else {
    while(tmp) {
      ret = log_add_target(tmp->string_);
      if(ret) {
        switch(ret) {
        case -2: fprintf(stderr, "memory error on log_add_target, exitting\n"); break;
        case -3: fprintf(stderr, "unknown log target: '%s', exitting\n", tmp->string_); break;
        case -4: fprintf(stderr, "this log target is only allowed once: '%s', exitting\n", tmp->string_); break;
        default: fprintf(stderr, "syntax error near: '%s', exitting\n", tmp->string_); break;
        }

        options_clear(&opt);
        log_close();
        exit(ret);
      }
      tmp = tmp->next_;
    }
  }
  log_printf(NOTICE, "just started...");
  if(options_parse_post(&opt)) {
    options_clear(&opt);
    log_close();
    exit(-1);
  }

  priv_info_t priv;
  if(opt.username_)
    if(priv_init(&priv, opt.username_, opt.groupname_)) {
      options_clear(&opt);
      log_close();
      exit(-1);
    }

  FILE* pid_file = NULL;
  if(opt.pid_file_) {
    pid_file = fopen(opt.pid_file_, "w");
    if(!pid_file) {
      log_printf(WARNING, "unable to open pid file: %s", strerror(errno));
    }
  }

  if(opt.chroot_dir_)
    if(do_chroot(opt.chroot_dir_)) {
      options_clear(&opt);
      log_close();
      exit(-1);
    }
  if(opt.username_)
    if(priv_drop(&priv)) {
      options_clear(&opt);
      log_close();
      exit(-1);
    }

  if(opt.daemonize_) {
    pid_t oldpid = getpid();
    daemonize();
    log_printf(INFO, "running in background now (old pid: %d)", oldpid);
  }

  if(pid_file) {
    pid_t pid = getpid();
    fprintf(pid_file, "%d", pid);
    fclose(pid_file);
  }

  for(;;) {
        // extern global variable defined in l_cmd.c
    cmd_fd = connect_command_socket(opt.command_sock_);
    if(cmd_fd < 0)
      ret = 2;
    else {
      ret = main_loop(cmd_fd, &opt);
    }

    if(ret == 2) {
      log_printf(ERROR, "socket error, trying to reconnect in 5 seconds..");

      if(cmd_fd > 0)
        close(cmd_fd);
      sleep(5);
    }
    else
      break;
  }

  if(cmd_fd > 0)
    close(cmd_fd);

  if(!ret)
    log_printf(NOTICE, "normal shutdown");
  else if(ret < 0)
    log_printf(NOTICE, "shutdown after error (code %d)", ret);
  else
    log_printf(NOTICE, "shutdown after signal");

  options_clear(&opt);
  log_close();

  return ret;
}