#include "k5-int.h"
#include <stdio.h>
#if !defined(_WIN32)
#if HAVE_UNISTD_H
#include <unistd.h>
#endif
#include <errno.h>
#ifdef HAVE_FCNTL_H
#include <fcntl.h>
#endif
#if defined(HAVE_FCNTL_H) && defined(F_SETLKW) && defined(F_RDLCK)
#define POSIX_FILE_LOCKS
#endif
#ifdef HAVE_FLOCK
#ifndef sysvimp
#include <sys/file.h>
#endif
#else
#ifndef LOCK_SH
#define LOCK_SH 0
#define LOCK_EX 0
#define LOCK_UN 0
#endif
#endif
krb5_error_code
krb5_lock_file(krb5_context context, int fd, int mode)
{
int lock_flag = -1;
krb5_error_code retval = 0;
#ifdef POSIX_FILE_LOCKS
int lock_cmd = F_SETLKW;
struct flock lock_arg = { 0 };
#endif
switch (mode & ~KRB5_LOCKMODE_DONTBLOCK) {
case KRB5_LOCKMODE_SHARED:
#ifdef POSIX_FILE_LOCKS
lock_arg.l_type = F_RDLCK;
#endif
lock_flag = LOCK_SH;
break;
case KRB5_LOCKMODE_EXCLUSIVE:
#ifdef POSIX_FILE_LOCKS
lock_arg.l_type = F_WRLCK;
#endif
lock_flag = LOCK_EX;
break;
case KRB5_LOCKMODE_UNLOCK:
#ifdef POSIX_FILE_LOCKS
lock_arg.l_type = F_UNLCK;
#endif
lock_flag = LOCK_UN;
break;
}
if (lock_flag == -1)
return(KRB5_LIBOS_BADLOCKFLAG);
if (mode & KRB5_LOCKMODE_DONTBLOCK) {
#ifdef POSIX_FILE_LOCKS
lock_cmd = F_SETLK;
#endif
#ifdef HAVE_FLOCK
lock_flag |= LOCK_NB;
#endif
}
#ifdef POSIX_FILE_LOCKS
lock_arg.l_whence = 0;
lock_arg.l_start = 0;
lock_arg.l_len = 0;
if (fcntl(fd, lock_cmd, &lock_arg) == -1) {
if (errno == EACCES || errno == EAGAIN)
return(EAGAIN);
if (errno != EINVAL)
return(errno);
retval = errno;
} else
return 0;
#endif
#ifdef HAVE_FLOCK
if (flock(fd, lock_flag) == -1)
retval = errno;
#endif
return retval;
}
#else
krb5_error_code
krb5_lock_file(context, fd, mode)
krb5_context context;
int fd;
int mode;
{
return 0;
}
#endif