/* $Id$
 *
 * The Data Control Manager for Moira.
 *
 * Copyright (C) 1987-1998 by the Massachusetts Institute of Technology.
 * For copying and distribution information, see the file
 * <mit-copyright.h>.
 */

#include <mit-copyright.h>
#include <moira.h>
#include <moira_site.h>
#include "update.h"

#include <sys/param.h>
#include <sys/stat.h>
#include <sys/wait.h>

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

EXEC SQL INCLUDE sqlca;
void sqlglm(char *, unsigned int *, unsigned int *);

RCSID("$Header$");

int generate_service(char *name, int force);
void do_hosts(char *service);
int dcm_send_file(char *service, char *host, char *target);
int dcm_execute(char *service, char *host, char *script);
void dbmserr(void);

EXEC SQL WHENEVER SQLERROR DO dbmserr();

#define SQL_NO_MATCH 1403
#define SOFT_FAIL(x) (((x) == MR_NO_MEM) || ((x) == MR_CANT_CONNECT) || ((x) == MR_CCONFIG) || ((x) == MR_DEADLOCK) || ((x) == MR_BUSY) || ((x) == MR_ABORT))

char whobuf[256], *whoami = whobuf, *db = "moira";

int main(int argc, char **argv)
{
  int i;
  EXEC SQL BEGIN DECLARE SECTION;
  char buf[16], *name;
  int enable;
  EXEC SQL END DECLARE SECTION;
  struct save_queue *sq;
  int status;

  if (strchr(argv[0], '/'))
    strcpy(whoami, strrchr(argv[0], '/') + 1);
  else strcpy(whoami, argv[0]);
  umask(7);

  setvbuf(stderr, NULL, _IOLBF, BUFSIZ);
  setvbuf(stdout, NULL, _IOLBF, BUFSIZ);

  initialize_sms_error_table();
  initialize_krb_error_table();

  /* if services were specified on the command line, do just those ones */
  if (argc > 1)
    {
      for (i = 1; i < argc; i++)
	{
	  if (generate_service(argv[i], 1))
	    do_hosts(argv[i]);
	}
      exit(0);
    }

  /* if DCM is not enabled, exit after logging */
  if (!access(NODCMFILE, F_OK))
    {
      printf("/etc/nodcm exists -- exiting\n");
      exit(1);
    }

  EXEC SQL CONNECT :db IDENTIFIED BY :db;

  EXEC SQL SELECT value INTO :enable FROM numvalues WHERE name = 'dcm_enable';
  if (enable == 0)
    {
      printf("dcm_enable not set -- exiting\n");
      exit(1);
    }

  /* fetch list of services */
  EXEC SQL DECLARE csr_svc CURSOR FOR SELECT LOWER(name) FROM servers
    WHERE enable = 1 AND harderror = 0 AND update_int > 0;
  EXEC SQL OPEN csr_svc;
  sq = sq_create();
  while (1)
    {
      EXEC SQL FETCH csr_svc INTO :buf;
      if (sqlca.sqlcode)
	break;

      sq_save_data(sq, strdup(strtrim(buf)));
    }
  EXEC SQL CLOSE csr_svc;
  /* we will repeatedly open and close the db since it seems to get
     upset if you keep it open across a fork */
  EXEC SQL COMMIT RELEASE;

  /* Now run through list */
  while (sq_get_data(sq, &name))
    {
      if (generate_service(name, 0))
	{
	  switch (fork())
	    {
	    case -1:
	      fprintf(stderr, "dcm: could not fork for service %s -- exiting",
		      name);
	      exit(1);
	    case 0:
	      sprintf(strchr(whoami, '\0'), " (%s)", name);
	      do_hosts(name);
	      com_err(whoami, 0, "exiting");
	      exit(0);
	    default:
	      break;
	    }
	}
    }

  /* wait for children */
  while (waitpid(0, &status, 0) > 0)
    ;
  com_err(whoami, 0, "exiting");
  exit(0);
}

int generate_service(char *name, int force)
{
  EXEC SQL BEGIN DECLARE SECTION;
  int interval, dfcheck, status;
  time_t now;
  const char *errmsg;
  EXEC SQL END DECLARE SECTION;
  char dfgen_prog[64], dfgen_cmd[128];
  struct sigaction action, prevaction;
  int waits;

  EXEC SQL CONNECT :db IDENTIFIED BY :db;

  EXEC SQL SELECT update_int, dfcheck	INTO :interval, :dfcheck
    FROM servers WHERE name = UPPER(:name);
  if (sqlca.sqlcode == SQL_NO_MATCH)
    {
      com_err(whoami, 0, "No such service `%s'", name);
      EXEC SQL COMMIT RELEASE;
      return 0;
    }

  time(&now);

  if ((interval * 60 + dfcheck < now) || force)
    {
      sprintf(dfgen_prog, "%s/%s.gen", BIN_DIR, name);
      if (access(dfgen_prog, F_OK) != 0)
	{
	  com_err(whoami, 0, "prog %s doesn't exist", dfgen_prog);
	  EXEC SQL COMMIT RELEASE;
	  return 0;
	}
      sprintf(dfgen_cmd, "exec %s %s/%s.out", dfgen_prog, DCM_DIR, name);
      com_err(whoami, 0, "running %s", dfgen_prog);

      EXEC SQL UPDATE servers SET inprogress = 1
	WHERE name = UPPER(:name);

      action.sa_flags = 0;
      sigemptyset(&action.sa_mask);
      action.sa_handler = SIG_DFL;
      sigaction(SIGCHLD, &action, &prevaction);
      waits = system(dfgen_cmd);
      sigaction(SIGCHLD, &prevaction, NULL);
      if (WIFSIGNALED(waits))
	{
	  status = MR_COREDUMP;
	  com_err(whoami, status, " %s exited on signal %d",
		  dfgen_prog, WTERMSIG(waits));
	}
      else if (WEXITSTATUS(waits))
	{
	  /* extract the process's exit value */
	  status = WEXITSTATUS(waits) + ERROR_TABLE_BASE_sms;
	  if (status != MR_NO_CHANGE)
	    com_err(whoami, status, "in %s", dfgen_prog);
	}
      else
	status = MR_SUCCESS;

      if (status == MR_SUCCESS)
	{
	  EXEC SQL UPDATE servers SET dfgen = :now, dfcheck = :now,
	    inprogress = 0 WHERE name = UPPER(:name);
	  EXEC SQL COMMIT RELEASE;
	  return 1;
	}
      else if (status == MR_NO_CHANGE)
	{
	  EXEC SQL UPDATE servers SET dfcheck = :now, inprogress = 0
	    WHERE name = UPPER(:name);
	}
      else if (SOFT_FAIL(status))
	{
	  errmsg = error_message(status);
	  EXEC SQL UPDATE servers SET errmsg = :errmsg, inprogress = 0
	    WHERE name = UPPER(:name);
	}
      else /* HARD_FAIL(status) */
	{
	  errmsg = error_message(status);
	  EXEC SQL UPDATE servers SET dfcheck = :now, harderror = :status,
	    errmsg = :errmsg, inprogress = 0 WHERE name = UPPER(:name);
	  critical_alert("DCM", "DCM building config files for %s: %s",
			 name, errmsg);
	}
    }
  EXEC SQL COMMIT RELEASE;
  return 0;
}

void do_hosts(char *service)
{
  EXEC SQL BEGIN DECLARE SECTION;
  char type[16], host[73], target[64], script[128];
  const char *errmsg;
  int status = 0, dfgen, replicated;
  time_t now;
  EXEC SQL END DECLARE SECTION;

  time(&now);
  mr_init();

  EXEC SQL CONNECT :db IDENTIFIED BY :db;

  EXEC SQL SELECT dfgen, type, target_file, script
    INTO :dfgen, :type, :target, :script
    FROM servers WHERE name = UPPER(:service);
  replicated = !strncmp(type, "REPLICAT", 8);

  EXEC SQL DECLARE csr_hst1 CURSOR FOR
    SELECT m.name FROM machine m, serverhosts sh
    WHERE sh.service = UPPER(:service)
    AND sh.enable = 1 AND sh.hosterror = 0
    AND sh.lts < :dfgen AND sh.mach_id = m.mach_id
    FOR UPDATE OF sh.inprogress, sh.hosterror, sh.hosterrmsg;
  EXEC SQL OPEN csr_hst1;

  while (1)
    {
      EXEC SQL FETCH csr_hst1 INTO :host;
      if (sqlca.sqlcode == SQL_NO_MATCH)
	break;

      com_err(whoami, 0, "sending %s data to %s", service, strtrim(host));
      EXEC SQL UPDATE serverhosts SET inprogress = 1
	WHERE CURRENT OF csr_hst1;
      status = dcm_send_file(service, host, strtrim(target));
      if (status)
	{
	  errmsg = error_message(status);
	  EXEC SQL UPDATE serverhosts SET hosterrmsg = :errmsg,
	    inprogress = 0 WHERE CURRENT OF csr_hst1;
	  if (!SOFT_FAIL(status))
	    {
	      EXEC SQL UPDATE serverhosts SET hosterror = :status
		WHERE CURRENT OF csr_hst1;
	      critical_alert("DCM", "DCM updating %s:%s: %s",
			     service, host, errmsg);
	    }

	  if (replicated)
	    break;
	}
    }
  EXEC SQL CLOSE csr_hst1;

  if (status == MR_SUCCESS || !replicated)
    {
      EXEC SQL DECLARE csr_hst2 CURSOR FOR
	SELECT m.name FROM machine m, serverhosts sh
	WHERE sh.service = UPPER(:service) AND sh.inprogress = 1
	AND sh.mach_id = m.mach_id
	FOR UPDATE OF sh.hosterror, sh.hosterrmsg, sh.inprogress;
      EXEC SQL OPEN csr_hst2;

      while (1)
	{
	  EXEC SQL FETCH csr_hst2 INTO :host;
	  if (sqlca.sqlcode == SQL_NO_MATCH)
	    break;

	  com_err(whoami, 0, "executing instructions on %s", strtrim(host));
	  status = dcm_execute(service, host, strtrim(script));
	  if (status)
	    {
	      errmsg = error_message(status);
	      EXEC SQL UPDATE serverhosts SET hosterrmsg = :errmsg,
		inprogress = 0 WHERE CURRENT OF csr_hst2;
	      if (!SOFT_FAIL(status))
		{
		  EXEC SQL UPDATE serverhosts SET hosterror = :status
		    WHERE CURRENT OF csr_hst2;
		  critical_alert("DCM", "DCM updating %s:%s: %s",
				 service, host, errmsg);
		}

	      if (replicated)
		{
		  /* We're giving up, so clear the inprogress flag on
		     any hosts in this service we haven't gotten to yet */
		  EXEC SQL UPDATE serverhosts SET inprogress = 0
		    WHERE service = UPPER(:service);
		  break;
		}
	    }
	  else
	    {
	      EXEC SQL UPDATE serverhosts SET inprogress = 0, lts = :now
		WHERE CURRENT OF csr_hst2;
	    }
	}
      EXEC SQL CLOSE csr_hst2;
    }

  if (status && replicated)
    {
      EXEC SQL UPDATE servers SET harderror = :status, errmsg = :errmsg
	WHERE name = UPPER(:service);
    }

  EXEC SQL COMMIT RELEASE;
}

int dcm_send_file(char *service, char *host, char *target)
{
  char data[MAXPATHLEN];
  int code, conn;

  conn = mr_connect_internal(host, "moira_update");
  if (!conn)
    {
      com_err(whoami, errno, "can't connect to %s", host);
      return MR_CANT_CONNECT;
    }

  code = send_auth(conn, host);
  if (code)
    {
      com_err(whoami, code, "authenticating to %s", host);
      goto done;
    }

  sprintf(data, "%s/%s.out", DCM_DIR, service);
  code = send_file(conn, data, target, 0);
  if (code)
    com_err(whoami, code, "sending data to %s", host);

done:
  send_quit(conn);
  close(conn);
  return code;
}

int dcm_execute(char *service, char *host, char *script)
{
  char inst[MAXPATHLEN];
  int code, conn;

  conn = mr_connect_internal(host, "moira_update");
  if (!conn)
    {
      com_err(whoami, errno, "can't connect to %s", host);
      return MR_CANT_CONNECT;
    }

  code = send_auth(conn, host);
  if (code)
    {
      com_err(whoami, code, "authenticating to %s", host);
      goto done;
    }

  sprintf(inst, "/tmp/moira-update.XXXXXX");
  mktemp(inst);
  code = send_file(conn, script, inst, 0);
  if (code)
    {
      com_err(whoami, code, "sending instructions to %s", host);
      goto done;
    }

  code = execute(conn, inst);
  if (code)
    com_err(whoami, code, "executing instructions on %s", host);

done:
  send_quit(conn);
  close(conn);
  return code;
}

void dbmserr(void)
{
  EXEC SQL BEGIN DECLARE SECTION;
  char err_msg[256];
  EXEC SQL END DECLARE SECTION;
  int bufsize = 256, msglength = 0;

  sqlglm(err_msg, &bufsize, &msglength);
  err_msg[msglength] = '\0';
  com_err(whoami, 0, "Encountered SQL error:\n%s", err_msg);
  com_err(whoami, 0, "exiting");
  exit(1);
}