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/*-
* See the file LICENSE for redistribution information.
*
* Copyright (c) 1997, 1998, 1999, 2000
* Sleepycat Software. All rights reserved.
*/
#include "db_config.h"
#ifndef lint
static const char revid[] = "$Id: os_open.c,v 11.21 2001/01/11 18:19:53 bostic Exp $";
#endif /* not lint */
#ifndef NO_SYSTEM_INCLUDES
#include <sys/types.h>
#include <fcntl.h>
#include <string.h>
#endif
#include "db_int.h"
#ifdef HAVE_QNX
static int __os_region_open __P((DB_ENV *, const char *, int, int, DB_FH *));
#endif
/*
* __os_open --
* Open a file.
*
* PUBLIC: int __os_open __P((DB_ENV *, const char *, u_int32_t, int, DB_FH *));
*/
int
__os_open(dbenv, name, flags, mode, fhp)
DB_ENV *dbenv;
const char *name;
u_int32_t flags;
int mode;
DB_FH *fhp;
{
int oflags, ret;
oflags = 0;
#if defined(O_BINARY)
/*
* If there's a binary-mode open flag, set it, we never want any
* kind of translation. Some systems do translations by default,
* e.g., with Cygwin, the default mode for an open() is set by the
* mode of the mount that underlies the file.
*/
oflags |= O_BINARY;
#endif
/*
* DB requires the POSIX 1003.1 semantic that two files opened at the
* same time with DB_OSO_CREATE/O_CREAT and DB_OSO_EXCL/O_EXCL flags
* set return an EEXIST failure in at least one.
*/
if (LF_ISSET(DB_OSO_CREATE))
oflags |= O_CREAT;
if (LF_ISSET(DB_OSO_EXCL))
oflags |= O_EXCL;
#if defined(O_DSYNC) && defined(XXX_NEVER_SET)
/*
* !!!
* We should get better performance if we push the log files to disk
* immediately instead of waiting for the sync. However, Solaris
* (and likely any other system based on the 4BSD filesystem releases),
* doesn't implement O_DSYNC correctly, only flushing data blocks and
* not inode or indirect blocks.
*/
if (LF_ISSET(DB_OSO_LOG))
oflags |= O_DSYNC;
#endif
if (LF_ISSET(DB_OSO_RDONLY))
oflags |= O_RDONLY;
else
oflags |= O_RDWR;
if (LF_ISSET(DB_OSO_TRUNC))
oflags |= O_TRUNC;
#ifdef HAVE_QNX
if (LF_ISSET(DB_OSO_REGION))
return (__os_region_open(dbenv, name, oflags, mode, fhp));
#endif
/* Open the file. */
if ((ret = __os_openhandle(dbenv, name, oflags, mode, fhp)) != 0)
return (ret);
/*
* Delete any temporary file.
*
* !!!
* There's a race here, where we've created a file and we crash before
* we can unlink it. Temporary files aren't common in DB, regardless,
* it's not a security problem because the file is empty. There's no
* reasonable way to avoid the race (playing signal games isn't worth
* the portability nightmare), so we just live with it.
*/
if (LF_ISSET(DB_OSO_TEMP))
(void)__os_unlink(dbenv, name);
return (0);
}
#ifdef HAVE_QNX
/*
* __os_region_open --
* Open a shared memory region file using POSIX shm_open.
*/
static int
__os_region_open(dbenv, name, oflags, mode, fhp)
DB_ENV *dbenv;
const char *name;
int oflags;
int mode;
DB_FH *fhp;
{
int ret;
char *newname;
if ((ret = __os_shmname(dbenv, name, &newname)) != 0)
goto err;
memset(fhp, 0, sizeof(*fhp));
fhp->fd = shm_open(newname, oflags, mode);
if (fhp->fd == -1)
ret = __os_get_errno();
else {
#ifdef HAVE_FCNTL_F_SETFD
/* Deny file descriptor acces to any child process. */
if (fcntl(fhp->fd, F_SETFD, 1) == -1) {
ret = __os_get_errno();
__db_err(dbenv, "fcntl(F_SETFD): %s", strerror(ret));
__os_closehandle(fhp);
} else
#endif
F_SET(fhp, DB_FH_VALID);
}
/*
* Once we have created the object, we don't need the name
* anymore. Other callers of this will convert themselves.
*/
err:
if (newname != NULL)
__os_free(newname, 0);
return (ret);
}
/*
* __os_shmname --
* Translate a pathname into a shm_open memory object name.
*
* PUBLIC: int __os_shmname __P((DB_ENV *, const char *, char **));
*/
int
__os_shmname(dbenv, name, newnamep)
DB_ENV *dbenv;
const char *name;
char **newnamep;
{
int ret;
size_t size;
char *p, *q, *tmpname;
*newnamep = NULL;
/*
* POSIX states that the name for a shared memory object
* may begin with a slash '/' and support for subsequent
* slashes is implementation-dependent. The one implementation
* we know of right now, QNX, forbids subsequent slashes.
* We don't want to be parsing pathnames for '.' and '..' in
* the middle. In order to allow easy conversion, just take
* the last component as the shared memory name. This limits
* the namespace a bit, but makes our job a lot easier.
*
* We should not be modifying user memory, so we use our own.
* Caller is responsible for freeing the memory we give them.
*/
if ((ret = __os_strdup(dbenv, name, &tmpname)) != 0)
return (ret);
/*
* Skip over filename component.
* We set that separator to '\0' so that we can do another
* __db_rpath. However, we immediately set it then to ':'
* so that we end up with the tailing directory:filename.
* We require a home directory component. Return an error
* if there isn't one.
*/
p = __db_rpath(tmpname);
if (p == NULL)
return (EINVAL);
if (p != tmpname) {
*p = '\0';
q = p;
p = __db_rpath(tmpname);
*q = ':';
}
if (p != NULL) {
/*
* If we have a path component, copy and return it.
*/
ret = __os_strdup(dbenv, p, newnamep);
__os_free(tmpname, 0);
return (ret);
}
/*
* We were given just a directory name with no path components.
* Add a leading slash, and copy the remainder.
*/
size = strlen(tmpname) + 2;
if ((ret = __os_malloc(dbenv, size, NULL, &p)) != 0)
return (ret);
p[0] = '/';
memcpy(&p[1], tmpname, size-1);
__os_free(tmpname, 0);
*newnamep = p;
return (0);
}
#endif
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