Skip to content
This repository

HTTPS clone URL

Subversion checkout URL

You can clone with HTTPS or Subversion.

Download ZIP
tree: e9bb4c9929
Fetching contributors…

Cannot retrieve contributors at this time

file 300 lines (262 sloc) 6.868 kb
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300
/*
* linux/fs/readdir.c
*
* Copyright (C) 1995 Linus Torvalds
*/

#include <linux/module.h>
#include <linux/time.h>
#include <linux/mm.h>
#include <linux/errno.h>
#include <linux/stat.h>
#include <linux/file.h>
#include <linux/smp_lock.h>
#include <linux/fs.h>
#include <linux/dirent.h>
#include <linux/security.h>
#include <linux/syscalls.h>
#include <linux/unistd.h>

#include <asm/uaccess.h>

int vfs_readdir(struct file *file, filldir_t filler, void *buf)
{
struct inode *inode = file->f_dentry->d_inode;
int res = -ENOTDIR;
if (!file->f_op || !file->f_op->readdir)
goto out;

res = security_file_permission(file, MAY_READ);
if (res)
goto out;

mutex_lock(&inode->i_mutex);
res = -ENOENT;
if (!IS_DEADDIR(inode)) {
res = file->f_op->readdir(file, buf, filler);
file_accessed(file);
}
mutex_unlock(&inode->i_mutex);
out:
return res;
}

EXPORT_SYMBOL(vfs_readdir);

/*
* Traditional linux readdir() handling..
*
* "count=1" is a special case, meaning that the buffer is one
* dirent-structure in size and that the code can't handle more
* anyway. Thus the special "fillonedir()" function for that
* case (the low-level handlers don't need to care about this).
*/
#define NAME_OFFSET(de) ((int) ((de)->d_name - (char __user *) (de)))
#define ROUND_UP(x) (((x)+sizeof(long)-1) & ~(sizeof(long)-1))

#ifdef __ARCH_WANT_OLD_READDIR

struct old_linux_dirent {
unsigned long d_ino;
unsigned long d_offset;
unsigned short d_namlen;
char d_name[1];
};

struct readdir_callback {
struct old_linux_dirent __user * dirent;
int result;
};

static int fillonedir(void * __buf, const char * name, int namlen, loff_t offset,
ino_t ino, unsigned int d_type)
{
struct readdir_callback * buf = (struct readdir_callback *) __buf;
struct old_linux_dirent __user * dirent;

if (buf->result)
return -EINVAL;
buf->result++;
dirent = buf->dirent;
if (!access_ok(VERIFY_WRITE, dirent,
(unsigned long)(dirent->d_name + namlen + 1) -
(unsigned long)dirent))
goto efault;
if ( __put_user(ino, &dirent->d_ino) ||
__put_user(offset, &dirent->d_offset) ||
__put_user(namlen, &dirent->d_namlen) ||
__copy_to_user(dirent->d_name, name, namlen) ||
__put_user(0, dirent->d_name + namlen))
goto efault;
return 0;
efault:
buf->result = -EFAULT;
return -EFAULT;
}

asmlinkage long old_readdir(unsigned int fd, struct old_linux_dirent __user * dirent, unsigned int count)
{
int error;
struct file * file;
struct readdir_callback buf;

error = -EBADF;
file = fget(fd);
if (!file)
goto out;

buf.result = 0;
buf.dirent = dirent;

error = vfs_readdir(file, fillonedir, &buf);
if (error >= 0)
error = buf.result;

fput(file);
out:
return error;
}

#endif /* __ARCH_WANT_OLD_READDIR */

/*
* New, all-improved, singing, dancing, iBCS2-compliant getdents()
* interface.
*/
struct linux_dirent {
unsigned long d_ino;
unsigned long d_off;
unsigned short d_reclen;
char d_name[1];
};

struct getdents_callback {
struct linux_dirent __user * current_dir;
struct linux_dirent __user * previous;
int count;
int error;
};

static int filldir(void * __buf, const char * name, int namlen, loff_t offset,
ino_t ino, unsigned int d_type)
{
struct linux_dirent __user * dirent;
struct getdents_callback * buf = (struct getdents_callback *) __buf;
int reclen = ROUND_UP(NAME_OFFSET(dirent) + namlen + 2);

buf->error = -EINVAL; /* only used if we fail.. */
if (reclen > buf->count)
return -EINVAL;
dirent = buf->previous;
if (dirent) {
if (__put_user(offset, &dirent->d_off))
goto efault;
}
dirent = buf->current_dir;
if (__put_user(ino, &dirent->d_ino))
goto efault;
if (__put_user(reclen, &dirent->d_reclen))
goto efault;
if (copy_to_user(dirent->d_name, name, namlen))
goto efault;
if (__put_user(0, dirent->d_name + namlen))
goto efault;
if (__put_user(d_type, (char __user *) dirent + reclen - 1))
goto efault;
buf->previous = dirent;
dirent = (void __user *)dirent + reclen;
buf->current_dir = dirent;
buf->count -= reclen;
return 0;
efault:
buf->error = -EFAULT;
return -EFAULT;
}

asmlinkage long sys_getdents(unsigned int fd, struct linux_dirent __user * dirent, unsigned int count)
{
struct file * file;
struct linux_dirent __user * lastdirent;
struct getdents_callback buf;
int error;

error = -EFAULT;
if (!access_ok(VERIFY_WRITE, dirent, count))
goto out;

error = -EBADF;
file = fget(fd);
if (!file)
goto out;

buf.current_dir = dirent;
buf.previous = NULL;
buf.count = count;
buf.error = 0;

error = vfs_readdir(file, filldir, &buf);
if (error < 0)
goto out_putf;
error = buf.error;
lastdirent = buf.previous;
if (lastdirent) {
if (put_user(file->f_pos, &lastdirent->d_off))
error = -EFAULT;
else
error = count - buf.count;
}

out_putf:
fput(file);
out:
return error;
}

#define ROUND_UP64(x) (((x)+sizeof(u64)-1) & ~(sizeof(u64)-1))

struct getdents_callback64 {
struct linux_dirent64 __user * current_dir;
struct linux_dirent64 __user * previous;
int count;
int error;
};

static int filldir64(void * __buf, const char * name, int namlen, loff_t offset,
ino_t ino, unsigned int d_type)
{
struct linux_dirent64 __user *dirent;
struct getdents_callback64 * buf = (struct getdents_callback64 *) __buf;
int reclen = ROUND_UP64(NAME_OFFSET(dirent) + namlen + 1);

buf->error = -EINVAL; /* only used if we fail.. */
if (reclen > buf->count)
return -EINVAL;
dirent = buf->previous;
if (dirent) {
if (__put_user(offset, &dirent->d_off))
goto efault;
}
dirent = buf->current_dir;
if (__put_user(ino, &dirent->d_ino))
goto efault;
if (__put_user(0, &dirent->d_off))
goto efault;
if (__put_user(reclen, &dirent->d_reclen))
goto efault;
if (__put_user(d_type, &dirent->d_type))
goto efault;
if (copy_to_user(dirent->d_name, name, namlen))
goto efault;
if (__put_user(0, dirent->d_name + namlen))
goto efault;
buf->previous = dirent;
dirent = (void __user *)dirent + reclen;
buf->current_dir = dirent;
buf->count -= reclen;
return 0;
efault:
buf->error = -EFAULT;
return -EFAULT;
}

asmlinkage long sys_getdents64(unsigned int fd, struct linux_dirent64 __user * dirent, unsigned int count)
{
struct file * file;
struct linux_dirent64 __user * lastdirent;
struct getdents_callback64 buf;
int error;

error = -EFAULT;
if (!access_ok(VERIFY_WRITE, dirent, count))
goto out;

error = -EBADF;
file = fget(fd);
if (!file)
goto out;

buf.current_dir = dirent;
buf.previous = NULL;
buf.count = count;
buf.error = 0;

error = vfs_readdir(file, filldir64, &buf);
if (error < 0)
goto out_putf;
error = buf.error;
lastdirent = buf.previous;
if (lastdirent) {
typeof(lastdirent->d_off) d_off = file->f_pos;
error = -EFAULT;
if (__put_user(d_off, &lastdirent->d_off))
goto out_putf;
error = count - buf.count;
}

out_putf:
fput(file);
out:
return error;
}
Something went wrong with that request. Please try again.