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/* Copyright (c) 2003-2005 MySQL AB
Use is subject to license terms
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; version 2 of the License.
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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA */
#include <ndb_global.h>
#include "NdbDaemon.h"
#define NdbDaemon_ErrorSize 500
long NdbDaemon_DaemonPid = 0;
int NdbDaemon_ErrorCode = 0;
char NdbDaemon_ErrorText[NdbDaemon_ErrorSize] = "";
int
NdbDaemon_Make(const char* lockfile, const char* logfile, unsigned flags)
{
int lockfd = -1, logfd = -1, n;
char buf[64];
(void)flags; /* remove warning for unused parameter */
/* Check that we have write access to lock file */
assert(lockfile != NULL);
lockfd = open(lockfile, O_CREAT|O_RDWR, 0644);
if (lockfd == -1) {
NdbDaemon_ErrorCode = errno;
snprintf(NdbDaemon_ErrorText, NdbDaemon_ErrorSize,
"%s: open for write failed: %s", lockfile, strerror(errno));
return -1;
}
/* Read any old pid from lock file */
buf[0] = 0;
n = read(lockfd, buf, sizeof(buf));
if (n < 0) {
NdbDaemon_ErrorCode = errno;
snprintf(NdbDaemon_ErrorText, NdbDaemon_ErrorSize,
"%s: read failed: %s", lockfile, strerror(errno));
return -1;
}
NdbDaemon_DaemonPid = atol(buf);
if (lseek(lockfd, 0, SEEK_SET) == -1) {
NdbDaemon_ErrorCode = errno;
snprintf(NdbDaemon_ErrorText, NdbDaemon_ErrorSize,
"%s: lseek failed: %s", lockfile, strerror(errno));
return -1;
}
#ifdef F_TLOCK
/* Test for lock before becoming daemon */
if (lockf(lockfd, F_TLOCK, 0) == -1)
{
if (errno == EACCES || errno == EAGAIN) { /* results may vary */
snprintf(NdbDaemon_ErrorText, NdbDaemon_ErrorSize,
"%s: already locked by pid=%ld", lockfile, NdbDaemon_DaemonPid);
return -1;
}
NdbDaemon_ErrorCode = errno;
snprintf(NdbDaemon_ErrorText, NdbDaemon_ErrorSize,
"%s: lock test failed: %s", lockfile, strerror(errno));
return -1;
}
#endif
/* Test open log file before becoming daemon */
if (logfile != NULL) {
logfd = open(logfile, O_CREAT|O_WRONLY|O_APPEND, 0644);
if (logfd == -1) {
NdbDaemon_ErrorCode = errno;
snprintf(NdbDaemon_ErrorText, NdbDaemon_ErrorSize,
"%s: open for write failed: %s", logfile, strerror(errno));
return -1;
}
}
#ifdef F_TLOCK
if (lockf(lockfd, F_ULOCK, 0) == -1)
{
snprintf(NdbDaemon_ErrorText, NdbDaemon_ErrorSize,
"%s: fail to unlock", lockfile);
return -1;
}
#endif
/* Fork */
n = fork();
if (n == -1) {
NdbDaemon_ErrorCode = errno;
snprintf(NdbDaemon_ErrorText, NdbDaemon_ErrorSize,
"fork failed: %s", strerror(errno));
return -1;
}
/* Exit if we are the parent */
if (n != 0) {
exit(0);
}
/* Running in child process */
NdbDaemon_DaemonPid = getpid();
/* Lock the lock file (likely to succeed due to test above) */
if (lockf(lockfd, F_LOCK, 0) == -1) {
NdbDaemon_ErrorCode = errno;
snprintf(NdbDaemon_ErrorText, NdbDaemon_ErrorSize,
"%s: lock failed: %s", lockfile, strerror(errno));
return -1;
}
/* Become process group leader */
if (setsid() == -1) {
NdbDaemon_ErrorCode = errno;
snprintf(NdbDaemon_ErrorText, NdbDaemon_ErrorSize,
"setsid failed: %s", strerror(errno));
return -1;
}
/* Write pid to lock file */
if (ftruncate(lockfd, 0) == -1) {
NdbDaemon_ErrorCode = errno;
snprintf(NdbDaemon_ErrorText, NdbDaemon_ErrorSize,
"%s: ftruncate failed: %s", lockfile, strerror(errno));
return -1;
}
sprintf(buf, "%ld\n", NdbDaemon_DaemonPid);
n = strlen(buf);
if (write(lockfd, buf, n) != n) {
NdbDaemon_ErrorCode = errno;
snprintf(NdbDaemon_ErrorText, NdbDaemon_ErrorSize,
"%s: write failed: %s", lockfile, strerror(errno));
return -1;
}
/* Do input/output redirections (assume fd 0,1,2 not in use) */
close(0);
open("/dev/null", O_RDONLY);
if (logfile != 0) {
dup2(logfd, 1);
dup2(logfd, 2);
close(logfd);
}
/* Success */
return 0;
}
#if 0
int
NdbDaemon_Make(const char* lockfile, const char* logfile, unsigned flags)
{
/* Fail */
snprintf(NdbDaemon_ErrorText, NdbDaemon_ErrorSize,
"Daemon mode not implemented");
return -1;
}
#endif
#ifdef NDB_DAEMON_TEST
int
main()
{
if (NdbDaemon_Make("test.pid", "test.log", 0) == -1) {
fprintf(stderr, "NdbDaemon_Make: %s\n", NdbDaemon_ErrorText);
return 1;
}
sleep(10);
return 0;
}
#endif
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