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/* This file takes care of those system calls that deal with time.
*
* The entry points into this file are
* do_utimens: perform the UTIMENS system call
*/
#include "fs.h"
#include <minix/callnr.h>
#include <minix/com.h>
#include <time.h>
#include <string.h>
#include <sys/stat.h>
#include <fcntl.h>
#include "file.h"
#include "path.h"
#include "vnode.h"
#include <minix/vfsif.h>
#include "vmnt.h"
#define UTIMENS_STYLE 0 /* utimes(2)/utimensat(2) style, named file */
#define FUTIMENS_STYLE 1 /* futimens(2)/futimes(2) style, file desc. */
/*===========================================================================*
* do_utimens *
*===========================================================================*/
int do_utimens(void)
{
/* Perform the utimens(name, times, flag) system call, and its friends.
* Implement a very large but not complete subset of the utimensat()
* Posix:2008/XOpen-7 function.
* Are handled all the following cases:
* . utimensat(AT_FDCWD, "/some/absolute/path", , )
* . utimensat(AT_FDCWD, "some/path", , )
* . utimens("anything", ) really special case of the above two
* . lutimens("anything", ) also really special case of the above
* . utimensat(fd, "/some/absolute/path", , ) although fd is useless here
* . futimens(fd, )
* Are not handled the following cases:
* . utimensat(fd, "some/path", , ) path to a file relative to some open fd
*/
int r, kind, lookup_flags;
struct vnode *vp;
struct filp *filp = NULL; /* initialization required by clueless GCC */
struct vmnt *vmp;
struct timespec actim, modtim, now, newactim, newmodtim;
char fullpath[PATH_MAX];
struct lookup resolve;
vir_bytes vname;
size_t vname_length;
memset(&now, 0, sizeof(now));
/* The case times==NULL is handled by the caller, replaced with UTIME_NOW */
actim.tv_sec = job_m_in.m_vfs_utimens.atime;
actim.tv_nsec = job_m_in.m_vfs_utimens.ansec;
modtim.tv_sec = job_m_in.m_vfs_utimens.mtime;
modtim.tv_nsec = job_m_in.m_vfs_utimens.mnsec;
if (job_m_in.m_vfs_utimens.name != NULL) {
kind = UTIMENS_STYLE;
if (job_m_in.m_vfs_utimens.flags & ~AT_SYMLINK_NOFOLLOW)
return EINVAL; /* unknown flag */
/* Temporarily open the file */
vname = (vir_bytes) job_m_in.m_vfs_utimens.name;
vname_length = (size_t) job_m_in.m_vfs_utimens.len;
if (job_m_in.m_vfs_utimens.flags & AT_SYMLINK_NOFOLLOW)
lookup_flags = PATH_RET_SYMLINK;
else
lookup_flags = PATH_NOFLAGS;
lookup_init(&resolve, fullpath, lookup_flags, &vmp, &vp);
resolve.l_vmnt_lock = VMNT_READ;
resolve.l_vnode_lock = VNODE_READ;
/* Temporarily open the file */
if (fetch_name(vname, vname_length, fullpath) != OK) return(err_code);
if ((vp = eat_path(&resolve, fp)) == NULL) return(err_code);
}
else {
kind = FUTIMENS_STYLE;
/* Change timestamps on already-opened fd. Is it valid? */
if (job_m_in.m_vfs_utimens.flags != 0)
return EINVAL; /* unknown flag */
if ((filp = get_filp(job_m_in.m_vfs_utimens.fd, VNODE_READ)) == NULL)
return err_code;
vp = filp->filp_vno;
}
r = OK;
/* Only the owner of a file or the super user can change timestamps. */
if (vp->v_uid != fp->fp_effuid && fp->fp_effuid != SU_UID) r = EPERM;
/* Need write permission (or super user) to 'touch' the file */
if (r != OK && actim.tv_nsec == UTIME_NOW
&& modtim.tv_nsec == UTIME_NOW) r = forbidden(fp, vp, W_BIT);
if (read_only(vp) != OK) r = EROFS; /* Not even su can touch if R/O */
if (r == OK) {
/* Do we need to ask for current time? */
if (actim.tv_nsec == UTIME_NOW
|| actim.tv_nsec == UTIME_OMIT
|| modtim.tv_nsec == UTIME_NOW
|| modtim.tv_nsec == UTIME_OMIT) {
(void)clock_time(&now);
}
/* Build the request */
switch (actim.tv_nsec) {
case UTIME_NOW:
newactim = now;
break;
case UTIME_OMIT:
newactim.tv_nsec = UTIME_OMIT;
/* Be nice with old FS, put a sensible value in
* otherwise not used field for seconds
*/
newactim.tv_sec = now.tv_sec;
break;
default:
if ( (unsigned)actim.tv_nsec >= 1000000000)
r = EINVAL;
else
newactim = actim;
break;
}
switch (modtim.tv_nsec) {
case UTIME_NOW:
newmodtim = now;
break;
case UTIME_OMIT:
newmodtim.tv_nsec = UTIME_OMIT;
/* Be nice with old FS, put a sensible value */
newmodtim.tv_sec = now.tv_sec;
break;
default:
if ( (unsigned)modtim.tv_nsec >= 1000000000)
r = EINVAL;
else
newmodtim = modtim;
break;
}
}
if (r == OK)
/* Issue request */
r = req_utime(vp->v_fs_e, vp->v_inode_nr, &newactim, &newmodtim);
if (kind == UTIMENS_STYLE) {
/* Close the temporary */
unlock_vnode(vp);
unlock_vmnt(vmp);
put_vnode(vp);
}
else { /* Change timestamps on opened fd. */
unlock_filp(filp);
}
return r;
}
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