Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 2 | * linux/fs/readdir.c |
| 3 | * |
| 4 | * Copyright (C) 1995 Linus Torvalds |
| 5 | */ |
| 6 | |
| 7 | #include <linux/module.h> |
| 8 | #include <linux/time.h> |
| 9 | #include <linux/mm.h> |
| 10 | #include <linux/errno.h> |
| 11 | #include <linux/stat.h> |
| 12 | #include <linux/file.h> |
| 13 | #include <linux/smp_lock.h> |
| 14 | #include <linux/fs.h> |
| 15 | #include <linux/dirent.h> |
| 16 | #include <linux/security.h> |
| 17 | #include <linux/syscalls.h> |
| 18 | #include <linux/unistd.h> |
| 19 | |
| 20 | #include <asm/uaccess.h> |
| 21 | |
| 22 | int vfs_readdir(struct file *file, filldir_t filler, void *buf) |
| 23 | { |
Josef "Jeff" Sipek | 0f7fc9e4 | 2006-12-08 02:36:35 -0800 | [diff] [blame] | 24 | struct inode *inode = file->f_path.dentry->d_inode; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 25 | int res = -ENOTDIR; |
| 26 | if (!file->f_op || !file->f_op->readdir) |
| 27 | goto out; |
| 28 | |
| 29 | res = security_file_permission(file, MAY_READ); |
| 30 | if (res) |
| 31 | goto out; |
| 32 | |
Jes Sorensen | 1b1dcc1 | 2006-01-09 15:59:24 -0800 | [diff] [blame] | 33 | mutex_lock(&inode->i_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 34 | res = -ENOENT; |
| 35 | if (!IS_DEADDIR(inode)) { |
| 36 | res = file->f_op->readdir(file, buf, filler); |
| 37 | file_accessed(file); |
| 38 | } |
Jes Sorensen | 1b1dcc1 | 2006-01-09 15:59:24 -0800 | [diff] [blame] | 39 | mutex_unlock(&inode->i_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 40 | out: |
| 41 | return res; |
| 42 | } |
| 43 | |
| 44 | EXPORT_SYMBOL(vfs_readdir); |
| 45 | |
| 46 | /* |
| 47 | * Traditional linux readdir() handling.. |
| 48 | * |
| 49 | * "count=1" is a special case, meaning that the buffer is one |
| 50 | * dirent-structure in size and that the code can't handle more |
| 51 | * anyway. Thus the special "fillonedir()" function for that |
| 52 | * case (the low-level handlers don't need to care about this). |
| 53 | */ |
| 54 | #define NAME_OFFSET(de) ((int) ((de)->d_name - (char __user *) (de))) |
| 55 | #define ROUND_UP(x) (((x)+sizeof(long)-1) & ~(sizeof(long)-1)) |
| 56 | |
| 57 | #ifdef __ARCH_WANT_OLD_READDIR |
| 58 | |
| 59 | struct old_linux_dirent { |
| 60 | unsigned long d_ino; |
| 61 | unsigned long d_offset; |
| 62 | unsigned short d_namlen; |
| 63 | char d_name[1]; |
| 64 | }; |
| 65 | |
| 66 | struct readdir_callback { |
| 67 | struct old_linux_dirent __user * dirent; |
| 68 | int result; |
| 69 | }; |
| 70 | |
| 71 | static int fillonedir(void * __buf, const char * name, int namlen, loff_t offset, |
David Howells | afefdbb | 2006-10-03 01:13:46 -0700 | [diff] [blame] | 72 | u64 ino, unsigned int d_type) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 73 | { |
| 74 | struct readdir_callback * buf = (struct readdir_callback *) __buf; |
| 75 | struct old_linux_dirent __user * dirent; |
David Howells | afefdbb | 2006-10-03 01:13:46 -0700 | [diff] [blame] | 76 | unsigned long d_ino; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 77 | |
| 78 | if (buf->result) |
| 79 | return -EINVAL; |
David Howells | afefdbb | 2006-10-03 01:13:46 -0700 | [diff] [blame] | 80 | d_ino = ino; |
| 81 | if (sizeof(d_ino) < sizeof(ino) && d_ino != ino) |
| 82 | return -EOVERFLOW; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 83 | buf->result++; |
| 84 | dirent = buf->dirent; |
| 85 | if (!access_ok(VERIFY_WRITE, dirent, |
| 86 | (unsigned long)(dirent->d_name + namlen + 1) - |
| 87 | (unsigned long)dirent)) |
| 88 | goto efault; |
David Howells | afefdbb | 2006-10-03 01:13:46 -0700 | [diff] [blame] | 89 | if ( __put_user(d_ino, &dirent->d_ino) || |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 90 | __put_user(offset, &dirent->d_offset) || |
| 91 | __put_user(namlen, &dirent->d_namlen) || |
| 92 | __copy_to_user(dirent->d_name, name, namlen) || |
| 93 | __put_user(0, dirent->d_name + namlen)) |
| 94 | goto efault; |
| 95 | return 0; |
| 96 | efault: |
| 97 | buf->result = -EFAULT; |
| 98 | return -EFAULT; |
| 99 | } |
| 100 | |
| 101 | asmlinkage long old_readdir(unsigned int fd, struct old_linux_dirent __user * dirent, unsigned int count) |
| 102 | { |
| 103 | int error; |
| 104 | struct file * file; |
| 105 | struct readdir_callback buf; |
| 106 | |
| 107 | error = -EBADF; |
| 108 | file = fget(fd); |
| 109 | if (!file) |
| 110 | goto out; |
| 111 | |
| 112 | buf.result = 0; |
| 113 | buf.dirent = dirent; |
| 114 | |
| 115 | error = vfs_readdir(file, fillonedir, &buf); |
| 116 | if (error >= 0) |
| 117 | error = buf.result; |
| 118 | |
| 119 | fput(file); |
| 120 | out: |
| 121 | return error; |
| 122 | } |
| 123 | |
| 124 | #endif /* __ARCH_WANT_OLD_READDIR */ |
| 125 | |
| 126 | /* |
| 127 | * New, all-improved, singing, dancing, iBCS2-compliant getdents() |
| 128 | * interface. |
| 129 | */ |
| 130 | struct linux_dirent { |
| 131 | unsigned long d_ino; |
| 132 | unsigned long d_off; |
| 133 | unsigned short d_reclen; |
| 134 | char d_name[1]; |
| 135 | }; |
| 136 | |
| 137 | struct getdents_callback { |
| 138 | struct linux_dirent __user * current_dir; |
| 139 | struct linux_dirent __user * previous; |
| 140 | int count; |
| 141 | int error; |
| 142 | }; |
| 143 | |
| 144 | static int filldir(void * __buf, const char * name, int namlen, loff_t offset, |
David Howells | afefdbb | 2006-10-03 01:13:46 -0700 | [diff] [blame] | 145 | u64 ino, unsigned int d_type) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 146 | { |
| 147 | struct linux_dirent __user * dirent; |
| 148 | struct getdents_callback * buf = (struct getdents_callback *) __buf; |
David Howells | afefdbb | 2006-10-03 01:13:46 -0700 | [diff] [blame] | 149 | unsigned long d_ino; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 150 | int reclen = ROUND_UP(NAME_OFFSET(dirent) + namlen + 2); |
| 151 | |
| 152 | buf->error = -EINVAL; /* only used if we fail.. */ |
| 153 | if (reclen > buf->count) |
| 154 | return -EINVAL; |
David Howells | afefdbb | 2006-10-03 01:13:46 -0700 | [diff] [blame] | 155 | d_ino = ino; |
| 156 | if (sizeof(d_ino) < sizeof(ino) && d_ino != ino) |
| 157 | return -EOVERFLOW; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 158 | dirent = buf->previous; |
| 159 | if (dirent) { |
| 160 | if (__put_user(offset, &dirent->d_off)) |
| 161 | goto efault; |
| 162 | } |
| 163 | dirent = buf->current_dir; |
David Howells | afefdbb | 2006-10-03 01:13:46 -0700 | [diff] [blame] | 164 | if (__put_user(d_ino, &dirent->d_ino)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 165 | goto efault; |
| 166 | if (__put_user(reclen, &dirent->d_reclen)) |
| 167 | goto efault; |
| 168 | if (copy_to_user(dirent->d_name, name, namlen)) |
| 169 | goto efault; |
| 170 | if (__put_user(0, dirent->d_name + namlen)) |
| 171 | goto efault; |
| 172 | if (__put_user(d_type, (char __user *) dirent + reclen - 1)) |
| 173 | goto efault; |
| 174 | buf->previous = dirent; |
| 175 | dirent = (void __user *)dirent + reclen; |
| 176 | buf->current_dir = dirent; |
| 177 | buf->count -= reclen; |
| 178 | return 0; |
| 179 | efault: |
| 180 | buf->error = -EFAULT; |
| 181 | return -EFAULT; |
| 182 | } |
| 183 | |
| 184 | asmlinkage long sys_getdents(unsigned int fd, struct linux_dirent __user * dirent, unsigned int count) |
| 185 | { |
| 186 | struct file * file; |
| 187 | struct linux_dirent __user * lastdirent; |
| 188 | struct getdents_callback buf; |
| 189 | int error; |
| 190 | |
| 191 | error = -EFAULT; |
| 192 | if (!access_ok(VERIFY_WRITE, dirent, count)) |
| 193 | goto out; |
| 194 | |
| 195 | error = -EBADF; |
| 196 | file = fget(fd); |
| 197 | if (!file) |
| 198 | goto out; |
| 199 | |
| 200 | buf.current_dir = dirent; |
| 201 | buf.previous = NULL; |
| 202 | buf.count = count; |
| 203 | buf.error = 0; |
| 204 | |
| 205 | error = vfs_readdir(file, filldir, &buf); |
| 206 | if (error < 0) |
| 207 | goto out_putf; |
| 208 | error = buf.error; |
| 209 | lastdirent = buf.previous; |
| 210 | if (lastdirent) { |
| 211 | if (put_user(file->f_pos, &lastdirent->d_off)) |
| 212 | error = -EFAULT; |
| 213 | else |
| 214 | error = count - buf.count; |
| 215 | } |
| 216 | |
| 217 | out_putf: |
| 218 | fput(file); |
| 219 | out: |
| 220 | return error; |
| 221 | } |
| 222 | |
| 223 | #define ROUND_UP64(x) (((x)+sizeof(u64)-1) & ~(sizeof(u64)-1)) |
| 224 | |
| 225 | struct getdents_callback64 { |
| 226 | struct linux_dirent64 __user * current_dir; |
| 227 | struct linux_dirent64 __user * previous; |
| 228 | int count; |
| 229 | int error; |
| 230 | }; |
| 231 | |
| 232 | static int filldir64(void * __buf, const char * name, int namlen, loff_t offset, |
David Howells | afefdbb | 2006-10-03 01:13:46 -0700 | [diff] [blame] | 233 | u64 ino, unsigned int d_type) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 234 | { |
| 235 | struct linux_dirent64 __user *dirent; |
| 236 | struct getdents_callback64 * buf = (struct getdents_callback64 *) __buf; |
| 237 | int reclen = ROUND_UP64(NAME_OFFSET(dirent) + namlen + 1); |
| 238 | |
| 239 | buf->error = -EINVAL; /* only used if we fail.. */ |
| 240 | if (reclen > buf->count) |
| 241 | return -EINVAL; |
| 242 | dirent = buf->previous; |
| 243 | if (dirent) { |
| 244 | if (__put_user(offset, &dirent->d_off)) |
| 245 | goto efault; |
| 246 | } |
| 247 | dirent = buf->current_dir; |
| 248 | if (__put_user(ino, &dirent->d_ino)) |
| 249 | goto efault; |
| 250 | if (__put_user(0, &dirent->d_off)) |
| 251 | goto efault; |
| 252 | if (__put_user(reclen, &dirent->d_reclen)) |
| 253 | goto efault; |
| 254 | if (__put_user(d_type, &dirent->d_type)) |
| 255 | goto efault; |
| 256 | if (copy_to_user(dirent->d_name, name, namlen)) |
| 257 | goto efault; |
| 258 | if (__put_user(0, dirent->d_name + namlen)) |
| 259 | goto efault; |
| 260 | buf->previous = dirent; |
| 261 | dirent = (void __user *)dirent + reclen; |
| 262 | buf->current_dir = dirent; |
| 263 | buf->count -= reclen; |
| 264 | return 0; |
| 265 | efault: |
| 266 | buf->error = -EFAULT; |
| 267 | return -EFAULT; |
| 268 | } |
| 269 | |
| 270 | asmlinkage long sys_getdents64(unsigned int fd, struct linux_dirent64 __user * dirent, unsigned int count) |
| 271 | { |
| 272 | struct file * file; |
| 273 | struct linux_dirent64 __user * lastdirent; |
| 274 | struct getdents_callback64 buf; |
| 275 | int error; |
| 276 | |
| 277 | error = -EFAULT; |
| 278 | if (!access_ok(VERIFY_WRITE, dirent, count)) |
| 279 | goto out; |
| 280 | |
| 281 | error = -EBADF; |
| 282 | file = fget(fd); |
| 283 | if (!file) |
| 284 | goto out; |
| 285 | |
| 286 | buf.current_dir = dirent; |
| 287 | buf.previous = NULL; |
| 288 | buf.count = count; |
| 289 | buf.error = 0; |
| 290 | |
| 291 | error = vfs_readdir(file, filldir64, &buf); |
| 292 | if (error < 0) |
| 293 | goto out_putf; |
| 294 | error = buf.error; |
| 295 | lastdirent = buf.previous; |
| 296 | if (lastdirent) { |
| 297 | typeof(lastdirent->d_off) d_off = file->f_pos; |
| 298 | error = -EFAULT; |
| 299 | if (__put_user(d_off, &lastdirent->d_off)) |
| 300 | goto out_putf; |
| 301 | error = count - buf.count; |
| 302 | } |
| 303 | |
| 304 | out_putf: |
| 305 | fput(file); |
| 306 | out: |
| 307 | return error; |
| 308 | } |