/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (the "License").
 * You may not use this file except in compliance with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */

/*
 * Copyright (c) 1994, 2010, Oracle and/or its affiliates. All rights reserved.
 */

/*      Copyright (c) 1983, 1984, 1985, 1986, 1987, 1988, 1989 AT&T     */
/*        All Rights Reserved   */

/*
 * Portions of this source code were derived from Berkeley 4.3 BSD
 * under license from the Regents of the University of California.
 */

/*
 * Get file attribute information through a file name or a file descriptor.
 */

#include <sys/param.h>
#include <sys/isa_defs.h>
#include <sys/types.h>
#include <sys/sysmacros.h>
#include <sys/cred.h>
#include <sys/systm.h>
#include <sys/errno.h>
#include <sys/fcntl.h>
#include <sys/pathname.h>
#include <sys/stat.h>
#include <sys/vfs.h>
#include <sys/vnode.h>
#include <sys/mode.h>
#include <sys/file.h>
#include <sys/proc.h>
#include <sys/uio.h>
#include <sys/debug.h>
#include <sys/cmn_err.h>
#include <c2/audit.h>
#include <fs/fs_subr.h>

/*
 * Get the vp to be stated and the cred to be used for the call
 * to VOP_GETATTR
 */

static int
cstatat_getvp(int fd, char *name, int follow, vnode_t **vp, cred_t **cred)
{
        vnode_t *startvp;
        file_t *fp;
        int error;
        cred_t *cr;
        int estale_retry = 0;

        *vp = NULL;

        /*
         * Only return EFAULT for fstatat when fd == AT_FDCWD && name == NULL
         */

        if (fd == AT_FDCWD) {
                startvp = NULL;
                cr = CRED();
                crhold(cr);
        } else {
                char startchar;

                if (copyin(name, &startchar, sizeof (char)))
                        return (EFAULT);
                if (startchar != '/') {
                        if ((fp = getf(fd)) == NULL) {
                                return (EBADF);
                        }
                        startvp = fp->f_vnode;
                        cr = fp->f_cred;
                        crhold(cr);
                        VN_HOLD(startvp);
                        releasef(fd);
                } else {
                        startvp = NULL;
                        cr = CRED();
                        crhold(cr);
                }
        }
        *cred = cr;

        if (AU_AUDITING() && startvp != NULL)
                audit_setfsat_path(1);

lookup:
        if (error = lookupnameat(name, UIO_USERSPACE, follow, NULLVPP,
            vp, startvp)) {
                if ((error == ESTALE) &&
                    fs_need_estale_retry(estale_retry++))
                        goto lookup;
                if (startvp != NULL)
                        VN_RELE(startvp);
                crfree(cr);
                return (error);
        }
        if (startvp != NULL)
                VN_RELE(startvp);

        return (0);
}

/*
 * Native syscall interfaces:
 *
 * N-bit kernel, N-bit applications, N-bit file offsets
 */

static int cstatat(int, char *, struct stat *, int, int);
static int cstat(vnode_t *vp, struct stat *, int, cred_t *);

/*
 * fstat can and should be fast, do an inline implementation here.
 */
#define FSTAT_BODY(fd, sb, statfn)                              \
        {                                                       \
                file_t *fp;                                     \
                int error;                                      \
                                                                \
                if (fd == AT_FDCWD)                             \
                        return (set_errno(EFAULT));             \
                if ((fp = getf(fd)) == NULL)                    \
                        return (set_errno(EBADF));              \
                error = statfn(fp->f_vnode, sb, 0, fp->f_cred); \
                releasef(fd);                                   \
                if (error)                                      \
                        return (set_errno(error));              \
                return (0);                                     \
        }

int
fstat(int fd, struct stat *sb)
{
        FSTAT_BODY(fd, sb, cstat)
}

int
fstatat(int fd, char *name, struct stat *sb, int flags)
{
        int followflag;
        int csflags;

        if (name == NULL)
                return (fstat(fd, sb));

        followflag = (flags & AT_SYMLINK_NOFOLLOW);
        csflags = (flags & _AT_TRIGGER ? ATTR_TRIGGER : 0);
        if (followflag == 0)
                csflags |= ATTR_REAL;   /* flag for procfs lookups */

        return (cstatat(fd, name, sb, followflag, csflags));
}

int
stat(char *name, struct stat *sb)
{
        return (fstatat(AT_FDCWD, name, sb, 0));
}

int
lstat(char *name, struct stat *sb)
{
        return (fstatat(AT_FDCWD, name, sb, AT_SYMLINK_NOFOLLOW));
}

/*
 * Common code for stat(), lstat(), and fstat().
 * (32-bit kernel, 32-bit applications, 32-bit files)
 * (64-bit kernel, 64-bit applications, 64-bit files)
 */
static int
cstat(vnode_t *vp, struct stat *ubp, int flag, cred_t *cr)
{
        struct vfssw *vswp;
        struct stat sb;
        vattr_t vattr;
        int error;

        vattr.va_mask = AT_STAT | AT_NBLOCKS | AT_BLKSIZE | AT_SIZE;
        if ((error = VOP_GETATTR(vp, &vattr, flag, cr, NULL)) != 0)
                return (error);
#ifdef  _ILP32
        /*
         * (32-bit kernel, 32-bit applications, 32-bit files)
         * NOTE: 32-bit kernel maintains a 64-bit unsigend va_size.
         *
         * st_size of devices (VBLK and VCHR special files) is a special case.
         * POSIX does not define size behavior for special files, so the
         * following Solaris specific behavior is not a violation. Solaris
         * returns the size of the device.
         *
         * For compatibility with 32-bit programs which happen to do stat() on
         * a (mknod) bigger than 2GB we suppress the large file EOVERFLOW and
         * instead we return the value MAXOFF32_T (LONG_MAX).
         *
         * 32-bit applications that care about the size of devices should be
         * built 64-bit or use a large file interface (lfcompile(7) or lf64(7)).
         */
        if ((vattr.va_size > MAXOFF32_T) &&
            ((vp->v_type == VBLK) || (vp->v_type == VCHR))) {
                /* OVERFLOW | UNKNOWN_SIZE */
                vattr.va_size = MAXOFF32_T;
        }
#endif  /* _ILP32 */
        if (vattr.va_size > MAXOFF_T || vattr.va_nblocks > LONG_MAX ||
            vattr.va_nodeid > ULONG_MAX)
                return (EOVERFLOW);

        bzero(&sb, sizeof (sb));
        sb.st_dev = vattr.va_fsid;
        sb.st_ino = (ino_t)vattr.va_nodeid;
        sb.st_mode = VTTOIF(vattr.va_type) | vattr.va_mode;
        sb.st_nlink = vattr.va_nlink;
        sb.st_uid = vattr.va_uid;
        sb.st_gid = vattr.va_gid;
        sb.st_rdev = vattr.va_rdev;
        sb.st_size = (off_t)vattr.va_size;
        sb.st_atim = vattr.va_atime;
        sb.st_mtim = vattr.va_mtime;
        sb.st_ctim = vattr.va_ctime;
        sb.st_blksize = vattr.va_blksize;
        sb.st_blocks = (blkcnt_t)vattr.va_nblocks;
        if (vp->v_vfsp != NULL) {
                vswp = &vfssw[vp->v_vfsp->vfs_fstype];
                if (vswp->vsw_name && *vswp->vsw_name)
                        (void) strcpy(sb.st_fstype, vswp->vsw_name);
        }
        if (copyout(&sb, ubp, sizeof (sb)))
                return (EFAULT);
        return (0);
}

static int
cstatat(int fd, char *name, struct stat *sb, int follow, int flags)
{
        vnode_t *vp;
        int error;
        cred_t *cred;
        int link_follow;
        int estale_retry = 0;

        link_follow = (follow == AT_SYMLINK_NOFOLLOW) ? NO_FOLLOW : FOLLOW;
lookup:
        if (error = cstatat_getvp(fd, name, link_follow, &vp, &cred))
                return (set_errno(error));
        error = cstat(vp, sb, flags, cred);
        crfree(cred);
        VN_RELE(vp);
        if (error != 0) {
                if (error == ESTALE &&
                    fs_need_estale_retry(estale_retry++))
                        goto lookup;
                return (set_errno(error));
        }
        return (0);
}

#if defined(_SYSCALL32_IMPL)

/*
 * 64-bit kernel, 32-bit applications, 32-bit file offsets
 */
static int cstatat32(int, char *, struct stat32 *, int, int);
static int cstat32(vnode_t *, struct stat32 *, int, cred_t *);

int
fstat32(int fd, struct stat32 *sb)
{
        FSTAT_BODY(fd, sb, cstat32)
}

int
fstatat32(int fd, char *name, struct stat32 *sb, int flags)
{
        int followflag;
        int csflags;

        if (name == NULL)
                return (fstat32(fd, sb));

        followflag = (flags & AT_SYMLINK_NOFOLLOW);
        csflags = (flags & _AT_TRIGGER ? ATTR_TRIGGER : 0);
        if (followflag == 0)
                csflags |= ATTR_REAL;   /* flag for procfs lookups */

        return (cstatat32(fd, name, sb, followflag, csflags));
}

int
stat32(char *name, struct stat32 *sb)
{
        return (fstatat32(AT_FDCWD, name, sb, 0));
}

int
lstat32(char *name, struct stat32 *sb)
{
        return (fstatat32(AT_FDCWD, name, sb, AT_SYMLINK_NOFOLLOW));
}

static int
cstat32(vnode_t *vp, struct stat32 *ubp, int flag, struct cred *cr)
{
        struct vfssw *vswp;
        struct stat32 sb;
        vattr_t vattr;
        int error;
        dev32_t st_dev, st_rdev;

        vattr.va_mask = AT_STAT | AT_NBLOCKS | AT_BLKSIZE | AT_SIZE;
        if (error = VOP_GETATTR(vp, &vattr, flag, cr, NULL))
                return (error);

        /* devices are a special case, see comments in cstat */
        if ((vattr.va_size > MAXOFF32_T) &&
            ((vp->v_type == VBLK) || (vp->v_type == VCHR))) {
                /* OVERFLOW | UNKNOWN_SIZE */
                vattr.va_size = MAXOFF32_T;
        }

        /* check for large values */
        if (!cmpldev(&st_dev, vattr.va_fsid) ||
            !cmpldev(&st_rdev, vattr.va_rdev) ||
            vattr.va_size > MAXOFF32_T ||
            vattr.va_nblocks > INT32_MAX ||
            vattr.va_nodeid > UINT32_MAX ||
            TIMESPEC_OVERFLOW(&(vattr.va_atime)) ||
            TIMESPEC_OVERFLOW(&(vattr.va_mtime)) ||
            TIMESPEC_OVERFLOW(&(vattr.va_ctime)))
                return (EOVERFLOW);

        bzero(&sb, sizeof (sb));
        sb.st_dev = st_dev;
        sb.st_ino = (ino32_t)vattr.va_nodeid;
        sb.st_mode = VTTOIF(vattr.va_type) | vattr.va_mode;
        sb.st_nlink = vattr.va_nlink;
        sb.st_uid = vattr.va_uid;
        sb.st_gid = vattr.va_gid;
        sb.st_rdev = st_rdev;
        sb.st_size = (off32_t)vattr.va_size;
        TIMESPEC_TO_TIMESPEC32(&(sb.st_atim), &(vattr.va_atime));
        TIMESPEC_TO_TIMESPEC32(&(sb.st_mtim), &(vattr.va_mtime));
        TIMESPEC_TO_TIMESPEC32(&(sb.st_ctim), &(vattr.va_ctime));
        sb.st_blksize = vattr.va_blksize;
        sb.st_blocks = (blkcnt32_t)vattr.va_nblocks;
        if (vp->v_vfsp != NULL) {
                vswp = &vfssw[vp->v_vfsp->vfs_fstype];
                if (vswp->vsw_name && *vswp->vsw_name)
                        (void) strcpy(sb.st_fstype, vswp->vsw_name);
        }
        if (copyout(&sb, ubp, sizeof (sb)))
                return (EFAULT);
        return (0);
}

static int
cstatat32(int fd, char *name, struct stat32 *sb, int follow, int flags)
{
        vnode_t *vp;
        int error;
        cred_t *cred;
        int link_follow;
        int estale_retry = 0;

        link_follow = (follow == AT_SYMLINK_NOFOLLOW) ? NO_FOLLOW : FOLLOW;
lookup:
        if (error = cstatat_getvp(fd, name, link_follow, &vp, &cred))
                return (set_errno(error));
        error = cstat32(vp, sb, flags, cred);
        crfree(cred);
        VN_RELE(vp);
        if (error != 0) {
                if (error == ESTALE &&
                    fs_need_estale_retry(estale_retry++))
                        goto lookup;
                return (set_errno(error));
        }
        return (0);
}

#endif  /* _SYSCALL32_IMPL */

#if defined(_ILP32)

/*
 * 32-bit kernel, 32-bit applications, 64-bit file offsets.
 *
 * These routines are implemented differently on 64-bit kernels.
 */
static int cstatat64(int, char *, struct stat64 *, int, int);
static int cstat64(vnode_t *, struct stat64 *, int, cred_t *);

int
fstat64(int fd, struct stat64 *sb)
{
        FSTAT_BODY(fd, sb, cstat64)
}

int
fstatat64(int fd, char *name, struct stat64 *sb, int flags)
{
        int followflag;
        int csflags;

        if (name == NULL)
                return (fstat64(fd, sb));

        followflag = (flags & AT_SYMLINK_NOFOLLOW);
        csflags = (flags & _AT_TRIGGER ? ATTR_TRIGGER : 0);
        if (followflag == 0)
                csflags |= ATTR_REAL;   /* flag for procfs lookups */

        return (cstatat64(fd, name, sb, followflag, csflags));
}

int
stat64(char *name, struct stat64 *sb)
{
        return (fstatat64(AT_FDCWD, name, sb, 0));
}

int
lstat64(char *name, struct stat64 *sb)
{
        return (fstatat64(AT_FDCWD, name, sb, AT_SYMLINK_NOFOLLOW));
}

static int
cstat64(vnode_t *vp, struct stat64 *ubp, int flag, cred_t *cr)
{
        struct vfssw *vswp;
        struct stat64 lsb;
        vattr_t vattr;
        int error;

        vattr.va_mask = AT_STAT | AT_NBLOCKS | AT_BLKSIZE | AT_SIZE;
        if (error = VOP_GETATTR(vp, &vattr, flag, cr, NULL))
                return (error);

        bzero(&lsb, sizeof (lsb));
        lsb.st_dev = vattr.va_fsid;
        lsb.st_ino = vattr.va_nodeid;
        lsb.st_mode = VTTOIF(vattr.va_type) | vattr.va_mode;
        lsb.st_nlink = vattr.va_nlink;
        lsb.st_uid = vattr.va_uid;
        lsb.st_gid = vattr.va_gid;
        lsb.st_rdev = vattr.va_rdev;
        lsb.st_size = vattr.va_size;
        lsb.st_atim = vattr.va_atime;
        lsb.st_mtim = vattr.va_mtime;
        lsb.st_ctim = vattr.va_ctime;
        lsb.st_blksize = vattr.va_blksize;
        lsb.st_blocks = vattr.va_nblocks;
        if (vp->v_vfsp != NULL) {
                vswp = &vfssw[vp->v_vfsp->vfs_fstype];
                if (vswp->vsw_name && *vswp->vsw_name)
                        (void) strcpy(lsb.st_fstype, vswp->vsw_name);
        }
        if (copyout(&lsb, ubp, sizeof (lsb)))
                return (EFAULT);
        return (0);
}

static int
cstatat64(int fd, char *name, struct stat64 *sb, int follow, int flags)
{
        vnode_t *vp;
        int error;
        cred_t *cred;
        int link_follow;
        int estale_retry = 0;

        link_follow = (follow == AT_SYMLINK_NOFOLLOW) ? NO_FOLLOW : FOLLOW;
lookup:
        if (error = cstatat_getvp(fd, name, link_follow, &vp, &cred))
                return (set_errno(error));
        error = cstat64(vp, sb, flags, cred);
        crfree(cred);
        VN_RELE(vp);
        if (error != 0) {
                if (error == ESTALE &&
                    fs_need_estale_retry(estale_retry++))
                        goto lookup;
                return (set_errno(error));
        }
        return (0);
}

#endif  /* _ILP32 */

#if defined(_SYSCALL32_IMPL)

/*
 * 64-bit kernel, 32-bit applications, 64-bit file offsets.
 *
 * We'd really like to call the "native" stat calls for these ones,
 * but the problem is that the 64-bit ABI defines the 'stat64' structure
 * differently from the way the 32-bit ABI defines it.
 */

static int cstatat64_32(int, char *, struct stat64_32 *, int, int);
static int cstat64_32(vnode_t *, struct stat64_32 *, int, cred_t *);

int
fstat64_32(int fd, struct stat64_32 *sb)
{
        FSTAT_BODY(fd, sb, cstat64_32)
}

int
fstatat64_32(int fd, char *name, struct stat64_32 *sb, int flags)
{
        int followflag;
        int csflags;

        if (name == NULL)
                return (fstat64_32(fd, sb));

        followflag = (flags & AT_SYMLINK_NOFOLLOW);
        csflags = (flags & _AT_TRIGGER ? ATTR_TRIGGER : 0);
        if (followflag == 0)
                csflags |= ATTR_REAL;   /* flag for procfs lookups */

        return (cstatat64_32(fd, name, sb, followflag, csflags));
}

int
stat64_32(char *name, struct stat64_32 *sb)
{
        return (fstatat64_32(AT_FDCWD, name, sb, 0));
}

int
lstat64_32(char *name, struct stat64_32 *sb)
{
        return (fstatat64_32(AT_FDCWD, name, sb, AT_SYMLINK_NOFOLLOW));
}

static int
cstat64_32(vnode_t *vp, struct stat64_32 *ubp, int flag, cred_t *cr)
{
        struct vfssw *vswp;
        struct stat64_32 lsb;
        vattr_t vattr;
        int error;
        dev32_t st_dev, st_rdev;

        vattr.va_mask = AT_STAT | AT_NBLOCKS | AT_BLKSIZE | AT_SIZE;
        if (error = VOP_GETATTR(vp, &vattr, flag, cr, NULL))
                return (error);

        if (!cmpldev(&st_dev, vattr.va_fsid) ||
            !cmpldev(&st_rdev, vattr.va_rdev) ||
            TIMESPEC_OVERFLOW(&(vattr.va_atime)) ||
            TIMESPEC_OVERFLOW(&(vattr.va_mtime)) ||
            TIMESPEC_OVERFLOW(&(vattr.va_ctime)))
                return (EOVERFLOW);

        bzero(&lsb, sizeof (lsb));
        lsb.st_dev = st_dev;
        lsb.st_ino = vattr.va_nodeid;
        lsb.st_mode = VTTOIF(vattr.va_type) | vattr.va_mode;
        lsb.st_nlink = vattr.va_nlink;
        lsb.st_uid = vattr.va_uid;
        lsb.st_gid = vattr.va_gid;
        lsb.st_rdev = st_rdev;
        lsb.st_size = vattr.va_size;
        TIMESPEC_TO_TIMESPEC32(&(lsb.st_atim), &(vattr.va_atime));
        TIMESPEC_TO_TIMESPEC32(&(lsb.st_mtim), &(vattr.va_mtime));
        TIMESPEC_TO_TIMESPEC32(&(lsb.st_ctim), &(vattr.va_ctime));
        lsb.st_blksize = vattr.va_blksize;
        lsb.st_blocks = vattr.va_nblocks;
        if (vp->v_vfsp != NULL) {
                vswp = &vfssw[vp->v_vfsp->vfs_fstype];
                if (vswp->vsw_name && *vswp->vsw_name)
                        (void) strcpy(lsb.st_fstype, vswp->vsw_name);
        }
        if (copyout(&lsb, ubp, sizeof (lsb)))
                return (EFAULT);
        return (0);
}

static int
cstatat64_32(int fd, char *name, struct stat64_32 *sb, int follow, int flags)
{
        vnode_t  *vp;
        int error;
        cred_t *cred;
        int link_follow;
        int estale_retry = 0;

        link_follow = (follow == AT_SYMLINK_NOFOLLOW) ? NO_FOLLOW : FOLLOW;
lookup:
        if (error = cstatat_getvp(fd, name, link_follow, &vp, &cred))
                return (set_errno(error));
        error = cstat64_32(vp, sb, flags, cred);
        crfree(cred);
        VN_RELE(vp);
        if (error != 0) {
                if (error == ESTALE &&
                    fs_need_estale_retry(estale_retry++))
                        goto lookup;
                return (set_errno(error));
        }
        return (0);
}

#endif /* _SYSCALL32_IMPL */