/*
 *  linux/fs/compat.c
 *
 *  Kernel compatibililty routines for e.g. 32 bit syscall support
 *  on 64 bit kernels.
 *
 *  Copyright (C) 2002       Stephen Rothwell, IBM Corporation
 *  Copyright (C) 1997-2000  Jakub Jelinek  (jakub@redhat.com)
 *  Copyright (C) 1998       Eddie C. Dost  (ecd@skynet.be)
 *  Copyright (C) 2001,2002  Andi Kleen, SuSE Labs 
 *  Copyright (C) 2003       Pavel Machek (pavel@suse.cz)
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License version 2 as
 *  published by the Free Software Foundation.
 */

#include <linux/linkage.h>
#include <linux/compat.h>
#include <linux/errno.h>
#include <linux/time.h>
#include <linux/fs.h>
#include <linux/fcntl.h>
#include <linux/namei.h>
#include <linux/file.h>
#include <linux/vfs.h>
#include <linux/ioctl32.h>
#include <linux/init.h>
#include <linux/sockios.h>      /* for SIOCDEVPRIVATE */
#include <linux/smp_lock.h>
#include <linux/ctype.h>
#include <linux/module.h>
#include <net/sock.h>           /* siocdevprivate_ioctl */

#include <asm/uaccess.h>

/*
 * Not all architectures have sys_utime, so implement this in terms
 * of sys_utimes.
 */
asmlinkage long compat_sys_utime(char *filename, struct compat_utimbuf *t)
{
        struct timeval tv[2];

        if (t) {
                if (get_user(tv[0].tv_sec, &t->actime) ||
                    get_user(tv[1].tv_sec, &t->modtime))
                        return -EFAULT;
                tv[0].tv_usec = 0;
                tv[1].tv_usec = 0;
        }
        return do_utimes(filename, t ? tv : NULL);
}

asmlinkage long compat_sys_utimes(char *filename, struct compat_timeval *t)
{
        struct timeval tv[2];

        if (t) { 
                if (get_user(tv[0].tv_sec, &t[0].tv_sec) ||
                    get_user(tv[0].tv_usec, &t[0].tv_usec) ||
                    get_user(tv[1].tv_sec, &t[1].tv_sec) ||
                    get_user(tv[1].tv_usec, &t[1].tv_usec))
                        return -EFAULT; 
        } 
        return do_utimes(filename, t ? tv : NULL);
}

asmlinkage long compat_sys_newstat(char * filename,
                struct compat_stat *statbuf)
{
        struct kstat stat;
        int error = vfs_stat(filename, &stat);

        if (!error)
                error = cp_compat_stat(&stat, statbuf);
        return error;
}

asmlinkage long compat_sys_newlstat(char * filename,
                struct compat_stat *statbuf)
{
        struct kstat stat;
        int error = vfs_lstat(filename, &stat);

        if (!error)
                error = cp_compat_stat(&stat, statbuf);
        return error;
}

asmlinkage long compat_sys_newfstat(unsigned int fd,
                struct compat_stat * statbuf)
{
        struct kstat stat;
        int error = vfs_fstat(fd, &stat);

        if (!error)
                error = cp_compat_stat(&stat, statbuf);
        return error;
}

static int put_compat_statfs(struct compat_statfs *ubuf, struct kstatfs *kbuf)
{
        
        if (sizeof ubuf->f_blocks == 4) {
                if ((kbuf->f_blocks | kbuf->f_bfree |
                     kbuf->f_bavail | kbuf->f_files | kbuf->f_ffree) &
                    0xffffffff00000000ULL)
                        return -EOVERFLOW;
        }
        if (verify_area(VERIFY_WRITE, ubuf, sizeof(*ubuf)) ||
            __put_user(kbuf->f_type, &ubuf->f_type) ||
            __put_user(kbuf->f_bsize, &ubuf->f_bsize) ||
            __put_user(kbuf->f_blocks, &ubuf->f_blocks) ||
            __put_user(kbuf->f_bfree, &ubuf->f_bfree) ||
            __put_user(kbuf->f_bavail, &ubuf->f_bavail) ||
            __put_user(kbuf->f_files, &ubuf->f_files) ||
            __put_user(kbuf->f_ffree, &ubuf->f_ffree) ||
            __put_user(kbuf->f_namelen, &ubuf->f_namelen) ||
            __put_user(kbuf->f_fsid.val[0], &ubuf->f_fsid.val[0]) ||
            __put_user(kbuf->f_fsid.val[1], &ubuf->f_fsid.val[1]) ||
            __put_user(kbuf->f_frsize, &ubuf->f_frsize) ||
            __put_user(0, &ubuf->f_spare[0]) || 
            __put_user(0, &ubuf->f_spare[1]) || 
            __put_user(0, &ubuf->f_spare[2]) || 
            __put_user(0, &ubuf->f_spare[3]) || 
            __put_user(0, &ubuf->f_spare[4]))
                return -EFAULT;
        return 0;
}

/*
 * The following statfs calls are copies of code from fs/open.c and
 * should be checked against those from time to time
 */
asmlinkage long compat_sys_statfs(const char *path, struct compat_statfs *buf)
{
        struct nameidata nd;
        int error;

        error = user_path_walk(path, &nd);
        if (!error) {
                struct kstatfs tmp;
                error = vfs_statfs(nd.dentry->d_inode->i_sb, &tmp);
                if (!error && put_compat_statfs(buf, &tmp))
                        error = -EFAULT;
                path_release(&nd);
        }
        return error;
}

asmlinkage long compat_sys_fstatfs(unsigned int fd, struct compat_statfs *buf)
{
        struct file * file;
        struct kstatfs tmp;
        int error;

        error = -EBADF;
        file = fget(fd);
        if (!file)
                goto out;
        error = vfs_statfs(file->f_dentry->d_inode->i_sb, &tmp);
        if (!error && put_compat_statfs(buf, &tmp))
                error = -EFAULT;
        fput(file);
out:
        return error;
}

static int put_compat_statfs64(struct compat_statfs64 *ubuf, struct kstatfs *kbuf)
{
        if (sizeof ubuf->f_blocks == 4) {
                if ((kbuf->f_blocks | kbuf->f_bfree |
                     kbuf->f_bavail | kbuf->f_files | kbuf->f_ffree) &
                    0xffffffff00000000ULL)
                        return -EOVERFLOW;
        }
        if (verify_area(VERIFY_WRITE, ubuf, sizeof(*ubuf)) ||
            __put_user(kbuf->f_type, &ubuf->f_type) ||
            __put_user(kbuf->f_bsize, &ubuf->f_bsize) ||
            __put_user(kbuf->f_blocks, &ubuf->f_blocks) ||
            __put_user(kbuf->f_bfree, &ubuf->f_bfree) ||
            __put_user(kbuf->f_bavail, &ubuf->f_bavail) ||
            __put_user(kbuf->f_files, &ubuf->f_files) ||
            __put_user(kbuf->f_ffree, &ubuf->f_ffree) ||
            __put_user(kbuf->f_namelen, &ubuf->f_namelen) ||
            __put_user(kbuf->f_fsid.val[0], &ubuf->f_fsid.val[0]) ||
            __put_user(kbuf->f_fsid.val[1], &ubuf->f_fsid.val[1]) ||
            __put_user(kbuf->f_frsize, &ubuf->f_frsize))
                return -EFAULT;
        return 0;
}

asmlinkage long compat_statfs64(const char *path, compat_size_t sz, struct compat_statfs64 *buf)
{
        struct nameidata nd;
        int error;

        if (sz != sizeof(*buf))
                return -EINVAL;

        error = user_path_walk(path, &nd);
        if (!error) {
                struct kstatfs tmp;
                error = vfs_statfs(nd.dentry->d_inode->i_sb, &tmp);
                if (!error && put_compat_statfs64(buf, &tmp))
                        error = -EFAULT;
                path_release(&nd);
        }
        return error;
}

asmlinkage long compat_fstatfs64(unsigned int fd, compat_size_t sz, struct compat_statfs64 *buf)
{
        struct file * file;
        struct kstatfs tmp;
        int error;

        if (sz != sizeof(*buf))
                return -EINVAL;

        error = -EBADF;
        file = fget(fd);
        if (!file)
                goto out;
        error = vfs_statfs(file->f_dentry->d_inode->i_sb, &tmp);
        if (!error && put_compat_statfs64(buf, &tmp))
                error = -EFAULT;
        fput(file);
out:
        return error;
}

/* ioctl32 stuff, used by sparc64, parisc, s390x, ppc64, x86_64 */

#define IOCTL_HASHSIZE 256
struct ioctl_trans *ioctl32_hash_table[IOCTL_HASHSIZE];

extern struct ioctl_trans ioctl_start[];
extern int ioctl_table_size;

static inline unsigned long ioctl32_hash(unsigned long cmd)
{
        return (((cmd >> 6) ^ (cmd >> 4) ^ cmd)) % IOCTL_HASHSIZE;
}

static void ioctl32_insert_translation(struct ioctl_trans *trans)
{
        unsigned long hash;
        struct ioctl_trans *t;

        hash = ioctl32_hash (trans->cmd);
        if (!ioctl32_hash_table[hash])
                ioctl32_hash_table[hash] = trans;
        else {
                t = ioctl32_hash_table[hash];
                while (t->next)
                        t = t->next;
                trans->next = 0;
                t->next = trans;
        }
}

static int __init init_sys32_ioctl(void)
{
        int i;

        for (i = 0; i < ioctl_table_size; i++) {
                if (ioctl_start[i].next != 0) { 
                        printk("ioctl translation %d bad\n",i); 
                        return -1;
                }

                ioctl32_insert_translation(&ioctl_start[i]);
        }
        return 0;
}

__initcall(init_sys32_ioctl);

static struct ioctl_trans *ioctl_free_list;

/* Never free them really. This avoids SMP races. With a Read-Copy-Update
   enabled kernel we could just use the RCU infrastructure for this. */
static void free_ioctl(struct ioctl_trans *t) 
{ 
        t->cmd = 0; 
        mb();
        t->next = ioctl_free_list;
        ioctl_free_list = t;
} 

int register_ioctl32_conversion(unsigned int cmd, int (*handler)(unsigned int, unsigned int, unsigned long, struct file *))
{
        struct ioctl_trans *t;
        unsigned long hash = ioctl32_hash(cmd);

        lock_kernel(); 
        for (t = (struct ioctl_trans *)ioctl32_hash_table[hash];
             t;
             t = t->next) { 
                if (t->cmd == cmd) {
                        printk("Trying to register duplicated ioctl32 handler %x\n", cmd);
                        unlock_kernel();
                        return -EINVAL; 
                }
        } 

        if (ioctl_free_list) { 
                t = ioctl_free_list; 
                ioctl_free_list = t->next; 
        } else { 
                t = kmalloc(sizeof(struct ioctl_trans), GFP_KERNEL); 
                if (!t) { 
                        unlock_kernel();
                        return -ENOMEM;
                }
        }
        
        t->next = NULL;
        t->cmd = cmd;
        t->handler = handler; 
        ioctl32_insert_translation(t);

        unlock_kernel();
        return 0;
}

static inline int builtin_ioctl(struct ioctl_trans *t)
{ 
        return t >= ioctl_start && t < (ioctl_start + ioctl_table_size);
} 

/* Problem: 
   This function cannot unregister duplicate ioctls, because they are not
   unique.
   When they happen we need to extend the prototype to pass the handler too. */

int unregister_ioctl32_conversion(unsigned int cmd)
{
        unsigned long hash = ioctl32_hash(cmd);
        struct ioctl_trans *t, *t1;

        lock_kernel(); 

        t = (struct ioctl_trans *)ioctl32_hash_table[hash];
        if (!t) { 
                unlock_kernel();
                return -EINVAL;
        } 

        if (t->cmd == cmd) { 
                if (builtin_ioctl(t)) {
                        printk("%p tried to unregister builtin ioctl %x\n",
                               __builtin_return_address(0), cmd);
                } else { 
                ioctl32_hash_table[hash] = t->next;
                        free_ioctl(t); 
                        unlock_kernel();
                return 0;
                }
        } 
        while (t->next) {
                t1 = (struct ioctl_trans *)(long)t->next;
                if (t1->cmd == cmd) { 
                        if (builtin_ioctl(t1)) {
                                printk("%p tried to unregister builtin ioctl %x\n",
                                       __builtin_return_address(0), cmd);
                                goto out;
                        } else { 
                        t->next = t1->next;
                                free_ioctl(t1); 
                                unlock_kernel();
                        return 0;
                        }
                }
                t = t1;
        }
        printk(KERN_ERR "Trying to free unknown 32bit ioctl handler %x\n", cmd);
 out:
        unlock_kernel();
        return -EINVAL;
}

EXPORT_SYMBOL(register_ioctl32_conversion); 
EXPORT_SYMBOL(unregister_ioctl32_conversion); 

asmlinkage long compat_sys_ioctl(unsigned int fd, unsigned int cmd, unsigned long arg)
{
        struct file * filp;
        int error = -EBADF;
        struct ioctl_trans *t;

        filp = fget(fd);
        if(!filp)
                goto out2;

        if (!filp->f_op || !filp->f_op->ioctl) {
                error = sys_ioctl (fd, cmd, arg);
                goto out;
        }

        t = (struct ioctl_trans *)ioctl32_hash_table [ioctl32_hash (cmd)];

        while (t && t->cmd != cmd)
                t = (struct ioctl_trans *)t->next;
        if (t) {
                if (t->handler)
                        error = t->handler(fd, cmd, arg, filp);
                else
                        error = sys_ioctl(fd, cmd, arg);
        } else if (cmd >= SIOCDEVPRIVATE && cmd <= (SIOCDEVPRIVATE + 15)) {
                error = siocdevprivate_ioctl(fd, cmd, arg);
        } else {
                static int count;
                if (++count <= 50) { 
                        char buf[10];
                        char *path = (char *)__get_free_page(GFP_KERNEL), *fn = "?"; 

                        /* find the name of the device. */
                        if (path) {
                                fn = d_path(filp->f_dentry, filp->f_vfsmnt, 
                                            path, PAGE_SIZE);
                        }

                        sprintf(buf,"'%c'", (cmd>>24) & 0x3f); 
                        if (!isprint(buf[1]))
                            sprintf(buf, "%02x", buf[1]);
                        printk("ioctl32(%s:%d): Unknown cmd fd(%d) "
                               "cmd(%08x){%s} arg(%08x) on %s\n",
                               current->comm, current->pid,
                               (int)fd, (unsigned int)cmd, buf, (unsigned int)arg,
                               fn);
                        if (path) 
                                free_page((unsigned long)path); 
                }
                error = -EINVAL;
        }
out:
        fput(filp);
out2:
        return error;
}

static int get_compat_flock(struct flock *kfl, struct compat_flock *ufl)
{
        if (!access_ok(VERIFY_READ, ufl, sizeof(*ufl)) ||
            __get_user(kfl->l_type, &ufl->l_type) ||
            __get_user(kfl->l_whence, &ufl->l_whence) ||
            __get_user(kfl->l_start, &ufl->l_start) ||
            __get_user(kfl->l_len, &ufl->l_len) ||
            __get_user(kfl->l_pid, &ufl->l_pid))
                return -EFAULT;
        return 0;
}

static int put_compat_flock(struct flock *kfl, struct compat_flock *ufl)
{
        if (!access_ok(VERIFY_WRITE, ufl, sizeof(*ufl)) ||
            __put_user(kfl->l_type, &ufl->l_type) ||
            __put_user(kfl->l_whence, &ufl->l_whence) ||
            __put_user(kfl->l_start, &ufl->l_start) ||
            __put_user(kfl->l_len, &ufl->l_len) ||
            __put_user(kfl->l_pid, &ufl->l_pid))
                return -EFAULT;
        return 0;
}

#ifndef HAVE_ARCH_GET_COMPAT_FLOCK64
static int get_compat_flock64(struct flock *kfl, struct compat_flock64 *ufl)
{
        if (!access_ok(VERIFY_READ, ufl, sizeof(*ufl)) ||
            __get_user(kfl->l_type, &ufl->l_type) ||
            __get_user(kfl->l_whence, &ufl->l_whence) ||
            __get_user(kfl->l_start, &ufl->l_start) ||
            __get_user(kfl->l_len, &ufl->l_len) ||
            __get_user(kfl->l_pid, &ufl->l_pid))
                return -EFAULT;
        return 0;
}
#endif

#ifndef HAVE_ARCH_PUT_COMPAT_FLOCK64
static int put_compat_flock64(struct flock *kfl, struct compat_flock64 *ufl)
{
        if (!access_ok(VERIFY_WRITE, ufl, sizeof(*ufl)) ||
            __put_user(kfl->l_type, &ufl->l_type) ||
            __put_user(kfl->l_whence, &ufl->l_whence) ||
            __put_user(kfl->l_start, &ufl->l_start) ||
            __put_user(kfl->l_len, &ufl->l_len) ||
            __put_user(kfl->l_pid, &ufl->l_pid))
                return -EFAULT;
        return 0;
}
#endif

extern asmlinkage long sys_fcntl(unsigned int, unsigned int, unsigned long);

asmlinkage long compat_sys_fcntl64(unsigned int fd, unsigned int cmd,
                unsigned long arg)
{
        mm_segment_t old_fs;
        struct flock f;
        long ret;

        switch (cmd) {
        case F_GETLK:
        case F_SETLK:
        case F_SETLKW:
                ret = get_compat_flock(&f, compat_ptr(arg));
                if (ret != 0)
                        break;
                old_fs = get_fs();
                set_fs(KERNEL_DS);
                ret = sys_fcntl(fd, cmd, (unsigned long)&f);
                set_fs(old_fs);
                if ((cmd == F_GETLK) && (ret == 0)) {
                        if ((f.l_start >= COMPAT_OFF_T_MAX) ||
                            ((f.l_start + f.l_len) >= COMPAT_OFF_T_MAX))
                                ret = -EOVERFLOW;
                        if (ret == 0)
                                ret = put_compat_flock(&f, compat_ptr(arg));
                }
                break;

        case F_GETLK64:
        case F_SETLK64:
        case F_SETLKW64:
                ret = get_compat_flock64(&f, compat_ptr(arg));
                if (ret != 0)
                        break;
                old_fs = get_fs();
                set_fs(KERNEL_DS);
                ret = sys_fcntl(fd, (cmd == F_GETLK64) ? F_GETLK :
                                ((cmd == F_SETLK64) ? F_SETLK : F_SETLKW),
                                (unsigned long)&f);
                set_fs(old_fs);
                if ((cmd == F_GETLK64) && (ret == 0)) {
                        if ((f.l_start >= COMPAT_LOFF_T_MAX) ||
                            ((f.l_start + f.l_len) >= COMPAT_LOFF_T_MAX))
                                ret = -EOVERFLOW;
                        if (ret == 0)
                                ret = put_compat_flock64(&f, compat_ptr(arg));
                }
                break;

        default:
                ret = sys_fcntl(fd, cmd, arg);
                break;
        }
        return ret;
}

asmlinkage long compat_sys_fcntl(unsigned int fd, unsigned int cmd,
                unsigned long arg)
{
        if ((cmd == F_GETLK64) || (cmd == F_SETLK64) || (cmd == F_SETLKW64))
                return -EINVAL;
        return compat_sys_fcntl64(fd, cmd, arg);
}

extern asmlinkage long sys_io_setup(unsigned nr_reqs, aio_context_t *ctx);

asmlinkage long
compat_sys_io_setup(unsigned nr_reqs, u32 *ctx32p)
{
        long ret;
        aio_context_t ctx64;

        mm_segment_t oldfs = get_fs();
        if (unlikely(get_user(ctx64, ctx32p)))
                return -EFAULT;

        set_fs(KERNEL_DS);
        ret = sys_io_setup(nr_reqs, &ctx64);
        set_fs(oldfs);
        /* truncating is ok because it's a user address */
        if (!ret)
                ret = put_user((u32) ctx64, ctx32p);
        return ret;
}

extern asmlinkage long sys_io_getevents(aio_context_t ctx_id,
                                          long min_nr,
                                          long nr,
                                          struct io_event *events,
                                          struct timespec *timeout);

asmlinkage long
compat_sys_io_getevents(aio_context_t ctx_id,
                                 unsigned long min_nr,
                                 unsigned long nr,
                                 struct io_event *events,
                                 struct compat_timespec *timeout)
{
        long ret;
        struct timespec t;
        struct timespec *ut = NULL;

        ret = -EFAULT;
        if (unlikely(!access_ok(VERIFY_WRITE, events, 
                                nr * sizeof(struct io_event))))
                goto out;
        if (timeout) {
                if (get_compat_timespec(&t, timeout))
                        goto out;

                ut = compat_alloc_user_space(sizeof(*ut));
                if (copy_to_user(ut, &t, sizeof(t)) )
                        goto out;
        } 
        ret = sys_io_getevents(ctx_id, min_nr, nr, events, ut);
out:
        return ret;
}

extern asmlinkage long sys_io_submit(aio_context_t, long, 
                                struct iocb __user **);

static inline long
copy_iocb(long nr, u32 *ptr32, u64 *ptr64)
{
        compat_uptr_t uptr;
        int i;

        for (i = 0; i < nr; ++i) {
                if (get_user(uptr, ptr32 + i))
                        return -EFAULT;
                if (put_user((u64)compat_ptr(uptr), ptr64 + i))
                        return -EFAULT;
        }
        return 0;
}

#define MAX_AIO_SUBMITS         (PAGE_SIZE/sizeof(struct iocb *))

asmlinkage long
compat_sys_io_submit(aio_context_t ctx_id, int nr, u32 *iocb)
{
        struct iocb **iocb64; 
        long ret;

        if (unlikely(nr < 0))
                return -EINVAL;

        if (nr > MAX_AIO_SUBMITS)
                nr = MAX_AIO_SUBMITS;
        
        iocb64 = compat_alloc_user_space(nr * sizeof(*iocb64));
        ret = copy_iocb(nr, iocb, (u64 *) iocb64);
        if (!ret)
                ret = sys_io_submit(ctx_id, nr, iocb64);
        return ret;
}