upsdrvctl.c

/* upsdrvctl.c - UPS driver controller

   Copyright (C) 2001  Russell Kroll <rkroll@exploits.org>

   This program 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 2 of the License, or
   (at your option) any later version.

   This program 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 this program; if not, write to the Free Software
   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <sys/stat.h>
#include <sys/wait.h>

#include "config.h"
#include "proto.h"
#include "version.h"
#include "common.h"
#include "upsconf.h"

typedef struct {
      char  *upsname;
      char  *driver;
      char  *port;
      int   sdorder;
      int   maxstartdelay;
      void  *next;
}     ups_t;

static      ups_t *upstable = NULL;

static      int   verbose = 0, maxsdorder = 0, testmode = 0, exec_error = 0;

      /* timer - keeps us from getting stuck if a driver hangs */
static      int   maxstartdelay = 45;

      /* Directory where driver executables live */
static      char  *driverpath = NULL;

      /* passthrough to the drivers: chroot path and new user name */
static      char  *pt_root = NULL, *pt_user = NULL;

static      sigset_t    nut_upsdrvctl_sigmask;
static      struct      sigaction   sa;

void do_upsconf_args(char *upsname, char *var, char *val)
{
      ups_t *tmp, *last;

      /* handle global declarations */
      if (!upsname) {
            if (!strcmp(var, "maxstartdelay"))
                  maxstartdelay = atoi(val);

            if (!strcmp(var, "driverpath")) {
                  if (driverpath)
                        free(driverpath);

                  driverpath = xstrdup(val);
            }

            /* ignore anything else - it's probably for main */

            return;
      }

      last = tmp = upstable;

      while (tmp) {
            last = tmp;

            if (!strcmp(tmp->upsname, upsname)) {
                  if (!strcmp(var, "driver")) 
                        tmp->driver = xstrdup(val);
                  if (!strcmp(var, "port")) 
                        tmp->port = xstrdup(val);
                  if (!strcmp(var, "maxstartdelay"))
                        tmp->maxstartdelay = atoi(val);

                  if (!strcmp(var, "sdorder")) {
                        tmp->sdorder = atoi(val);

                        if (tmp->sdorder > maxsdorder)
                              maxsdorder = tmp->sdorder;
                  }

                  return;
            }

            tmp = tmp->next;
      }

      tmp = xmalloc(sizeof(ups_t));
      tmp->upsname = xstrdup(upsname);
      tmp->driver = NULL;
      tmp->port = NULL;
      tmp->next = NULL;
      tmp->sdorder = 0;
      tmp->maxstartdelay = -1;      /* use global value by default */

      if (!strcmp(var, "driver"))
            tmp->driver = xstrdup(val);
      if (!strcmp(var, "port"))
            tmp->port = xstrdup(val);

      if (last)
            last->next = tmp;
      else
            upstable = tmp;
}

/* handle sending the signal */
static void send_term(char *upsname, char *driver, char *port)
{
      char  pidfn[SMALLBUF], buf[SMALLBUF];
      int   ret, pid;
      struct      stat  fs;
      FILE  *pidf;

      printf("Stopping UPS: %s\n", upsname);

      snprintf(pidfn, sizeof(pidfn), "%s/%s-%s.pid", altpidpath(),
            driver, xbasename(port));
      ret = stat(pidfn, &fs);

      if (ret != 0) {
            upslog(LOG_ERR, "Can't open %s", pidfn);
            exec_error++;
            return;
      }

      pidf = fopen(pidfn, "r");

      if (!pidf) {
            upslog(LOG_ERR, "Can't open %s", pidfn);
            exec_error++;
            return;
      }

      fgets(buf, sizeof(buf), pidf);
      buf[strlen(buf)-1] = '\0';

      pid = strtol(buf, (char **)NULL, 10);

      if (pid < 2) {
            upslogx(LOG_NOTICE, "Ignoring invalid pid %d in %s",
                  pid, pidfn);
            exec_error++;
            return;
      }

      if (verbose)
            printf("Sending signal: kill -TERM %d\n", pid);

      if (testmode)
            return;

      ret = kill(pid, SIGTERM);

      if (ret < 0) {
            upslog(LOG_ERR, "kill pid %d failed", pid);
            exec_error++;
            return;
      }
}

/* stop user-selected driver */
static void stop_one_driver(char *upsname)
{
      ups_t *tmp = upstable;

      if (!tmp)
            fatalx("Error: no UPS definitions found in ups.conf!\n");

      while (tmp) {
            if (!strcmp(tmp->upsname, upsname)) {
                  send_term(tmp->upsname, tmp->driver, tmp->port);
                  return;
            }

            tmp = tmp->next;
      }

      fatalx("UPS %s not found in ups.conf", upsname);
}

/* walk ups table, but stop drivers instead */
static void stop_all_drivers(void)
{
      ups_t *tmp = upstable;

      if (!tmp)
            fatalx("Error: no UPS definitions found in ups.conf!\n");

      while (tmp) {
            send_term(tmp->upsname, tmp->driver, tmp->port);

            tmp = tmp->next;
      }
}

static void waitpid_timeout(int sig)
{
      /* do nothing */
      return;
}

static void forkexec(const char *prog, char **argv, ups_t *ups)
{
      int   ret;
      pid_t pid;

      pid = fork();

      if (pid < 0)
            fatal("fork");

      if (pid != 0) {               /* parent */
            int   wstat;

            sigemptyset(&nut_upsdrvctl_sigmask);
            sa.sa_mask = nut_upsdrvctl_sigmask;
            sa.sa_flags = 0;
            sa.sa_handler = waitpid_timeout;
            sigaction(SIGALRM, &sa, NULL);

            if (ups->maxstartdelay != -1)
                  alarm(ups->maxstartdelay);
            else
                  alarm(maxstartdelay);

            ret = waitpid(pid, &wstat, 0);

            signal(SIGALRM, SIG_IGN);
            alarm(0);

            if (ret == -1) {
                  upslogx(LOG_WARNING, "Startup timer elapsed, continuing...");
                  exec_error++;
                  return;
            }

            if (WIFEXITED(wstat) == 0) {
                  upslogx(LOG_WARNING, "Driver exited abnormally");
                  exec_error++;
                  return;
            }

            if (WEXITSTATUS(wstat) != 0) {
                  upslogx(LOG_WARNING, "Driver failed to start"
                  " (exit status=%d)", WEXITSTATUS(wstat));
                  exec_error++;
                  return;
            }

            /* the rest only work when WIFEXITED is nonzero */

            if (WIFSIGNALED(wstat)) {
                  upslog(LOG_WARNING, "Driver died after signal %d",
                        WTERMSIG(wstat));
                  exec_error++;
            }

            return;
      }

      /* child */

      ret = execv(prog, argv);

      /* shouldn't get here */
      fatal("execv");
}           

static void start_driver(ups_t *ups)
{
      char  dfn[SMALLBUF], *argv[8];
      int   ret, arg = 0;
      struct      stat  fs;

      snprintf(dfn, sizeof(dfn), "%s/%s", driverpath, ups->driver);
      ret = stat(dfn, &fs);

      if (ret < 0)
            fatal("Can't start %s", dfn);

      if (verbose)
            printf("exec: %s -a %s", dfn, ups->upsname);

      argv[arg++] = xstrdup(dfn);

      argv[arg++] = "-a";
      argv[arg++] = ups->upsname;

      /* stick on the chroot / user args if given to us */
      if (pt_root) {
            argv[arg++] = "-r";
            argv[arg++] = pt_root;

            if (verbose)
                  printf(" -r %s", pt_root);
      }

      if (pt_user) {
            argv[arg++] = "-u";
            argv[arg++] = pt_user;

            if (verbose)
                  printf(" -u %s", pt_user);
      }

      if (verbose)
            printf("\n");
      if (testmode)
            return;

      /* tie it off */
      argv[arg++] = NULL;

      forkexec(dfn, argv, ups);
}

/* start user-selected driver */
static void start_one_driver(char *upsname)
{
      ups_t *tmp = upstable;

      if (!tmp)
            fatalx("Error: no UPS definitions found in ups.conf!\n");

      while (tmp) {
            if (!strcmp(tmp->upsname, upsname)) {
                  start_driver(tmp);
                  return;
            }

            tmp = tmp->next;
      }

      fatalx("UPS %s not found in ups.conf", upsname);
}

/* walk ups table and invoke drivers */
static void start_all_drivers(void)
{
      ups_t *tmp = upstable;

      if (!tmp)
            fatalx("Error: no UPS definitions found in ups.conf!\n");

      while (tmp) {
            start_driver(tmp);
            tmp = tmp->next;
      }
}

static void help(const char *progname)
{
      printf("Starts and stops UPS drivers via ups.conf.\n\n");
      printf("usage: %s [OPTIONS] (start | stop | shutdown) [<ups>]\n\n", progname);

      printf("  -h                  display this help\n");
      printf("  -r <path>           drivers will chroot to <path>\n");
      printf("  -t                  testing mode - prints actions without doing them\n");
      printf("  -u <user>           drivers started will switch from root to <user>\n");
      printf("  -v                  enable verbose messages\n");
      printf("  start               start all UPS drivers in ups.conf\n");
      printf("  start   <ups>       only start driver for UPS <ups>\n");
      printf("  stop                stop all UPS drivers in ups.conf\n");
      printf("  stop <ups>          only stop driver for UPS <ups>\n");
      printf("  shutdown            shutdown all UPS drivers in ups.conf\n");
      printf("  shutdown <ups>      only shutdown UPS <ups>\n");

      exit(EXIT_SUCCESS);
}

static void shutdown_driver(ups_t *ups)
{
      char  *argv[7], dfn[SMALLBUF];

      snprintf(dfn, sizeof(dfn), "%s/%s", driverpath, ups->driver);

      if (verbose)
            printf("exec: %s -a %s -k\n", dfn, ups->upsname);
      if (testmode)
            return;

      argv[0] = dfn;
      argv[1] = "-a";
      argv[2] = xstrdup(ups->upsname);
      argv[3] = "-k";
      argv[4] = NULL;

      forkexec(dfn, argv, ups);
}

static void shutdown_one_driver(char *upsname)
{
      ups_t *tmp = upstable;

      if (!tmp)
            fatalx("Error: no UPS definitions found in ups.conf!\n");

      while (tmp) {
            if (!strcmp(tmp->upsname, upsname)) {
                  shutdown_driver(tmp);
                  return;
            }

            tmp = tmp->next;
      }

      fatalx("UPS %s not found in ups.conf", upsname);
}

/* walk UPS table and shut down all UPSes according to sdorder */
static void shutdown_all_drivers(void)
{
      ups_t *tmp;
      int   i;

      if (!upstable)
            fatalx("Error: no UPS definitions found in ups.conf");

      for (i = 0; i <= maxsdorder; i++) {
            tmp = upstable;

            while (tmp) {
                  if (tmp->sdorder == i)
                        shutdown_driver(tmp);
                  
                  tmp = tmp->next;
            }
      }
}

static void exit_cleanup(void)
{
      ups_t *tmp, *next;

      tmp = upstable;

      while (tmp) {
            next = tmp->next;

            if (tmp->driver)
                  free(tmp->driver);
            if (tmp->port)
                  free(tmp->port);
            if (tmp->upsname)
                  free(tmp->upsname);
            free(tmp);

            tmp = next;
      }

      if (driverpath)
            free(driverpath);
}

int main(int argc, char **argv)
{
      int   i;
      char  *prog;

      printf("Network UPS Tools - UPS driver controller %s\n",
            UPS_VERSION);

      prog = argv[0];
      while ((i = getopt(argc, argv, "+htvu:r:V")) != EOF) {
            switch(i) {
                  case 'r':
                        pt_root = optarg;
                        break;

                  case 't':
                        testmode = 1;

                        /* force verbose mode while testing */
                        if (verbose == 0)
                              verbose = 1;

                        break;

                  case 'u':
                        pt_user = optarg;
                        break;

                  case 'v':
                        verbose++;
                        break;

                  case 'V':
                        exit(EXIT_SUCCESS);

                  case 'h':
                  default:
                        help(prog);
                        break;
            }
      }

      argc -= optind;
      argv += optind;

      if (argc < 1)
            help(prog);

      if (testmode)
            printf("*** Testing mode: not calling exec/kill\n");

      driverpath = xstrdup(DRVPATH);  /* set default */

      atexit(exit_cleanup);

      if (!strcmp(argv[0], "start")) {
            read_upsconf();

            if (argc == 1)
                  start_all_drivers();
            else
                  start_one_driver(argv[1]);

            if (exec_error)
                  exit(EXIT_FAILURE);

            exit(EXIT_SUCCESS);
      }

      if (!strcmp(argv[0], "stop")) {
            read_upsconf();

            if (argc == 1)
                  stop_all_drivers();
            else
                  stop_one_driver(argv[1]);

            if (exec_error)
                  exit(EXIT_FAILURE);

            exit(EXIT_SUCCESS);
      }

      if (!strcmp(argv[0], "shutdown")) {
            read_upsconf();

            if (argc == 1)
                  shutdown_all_drivers();
            else
                  shutdown_one_driver(argv[1]);

            if (exec_error)
                  exit(EXIT_FAILURE);

            exit(EXIT_SUCCESS);
      }

      fatalx("Error: unrecognized command [%s]\n", argv[0]);

      /* NOTREACHED */
      exit(EXIT_FAILURE);
}