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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 | /* * linux/fs/ioctl.c * * Copyright (C) 1991, 1992 Linus Torvalds */ #include <linux/syscalls.h> #include <linux/mm.h> #include <linux/smp_lock.h> #include <linux/capability.h> #include <linux/file.h> #include <linux/fs.h> #include <linux/security.h> #include <linux/module.h> #include <linux/uaccess.h> #include <asm/ioctls.h> /** * vfs_ioctl - call filesystem specific ioctl methods * @filp: open file to invoke ioctl method on * @cmd: ioctl command to execute * @arg: command-specific argument for ioctl * * Invokes filesystem specific ->unlocked_ioctl, if one exists; otherwise * invokes filesystem specific ->ioctl method. If neither method exists, * returns -ENOTTY. * * Returns 0 on success, -errno on error. */ static long vfs_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) { int error = -ENOTTY; if (!filp->f_op) goto out; if (filp->f_op->unlocked_ioctl) { error = filp->f_op->unlocked_ioctl(filp, cmd, arg); if (error == -ENOIOCTLCMD) error = -EINVAL; goto out; } else if (filp->f_op->ioctl) { lock_kernel(); error = filp->f_op->ioctl(filp->f_path.dentry->d_inode, filp, cmd, arg); unlock_kernel(); } out: return error; } static int ioctl_fibmap(struct file *filp, int __user *p) { struct address_space *mapping = filp->f_mapping; int res, block; /* do we support this mess? */ if (!mapping->a_ops->bmap) return -EINVAL; if (!capable(CAP_SYS_RAWIO)) return -EPERM; res = get_user(block, p); if (res) return res; lock_kernel(); res = mapping->a_ops->bmap(mapping, block); unlock_kernel(); return put_user(res, p); } static int file_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) { struct inode *inode = filp->f_path.dentry->d_inode; int __user *p = (int __user *)arg; switch (cmd) { case FIBMAP: return ioctl_fibmap(filp, p); case FIGETBSZ: return put_user(inode->i_sb->s_blocksize, p); case FIONREAD: return put_user(i_size_read(inode) - filp->f_pos, p); } return vfs_ioctl(filp, cmd, arg); } static int ioctl_fionbio(struct file *filp, int __user *argp) { unsigned int flag; int on, error; error = get_user(on, argp); if (error) return error; flag = O_NONBLOCK; #ifdef __sparc__ /* SunOS compatibility item. */ if (O_NONBLOCK != O_NDELAY) flag |= O_NDELAY; #endif if (on) filp->f_flags |= flag; else filp->f_flags &= ~flag; return error; } static int ioctl_fioasync(unsigned int fd, struct file *filp, int __user *argp) { unsigned int flag; int on, error; error = get_user(on, argp); if (error) return error; flag = on ? FASYNC : 0; /* Did FASYNC state change ? */ if ((flag ^ filp->f_flags) & FASYNC) { if (filp->f_op && filp->f_op->fasync) { lock_kernel(); error = filp->f_op->fasync(fd, filp, on); unlock_kernel(); } else error = -ENOTTY; } if (error) return error; if (on) filp->f_flags |= FASYNC; else filp->f_flags &= ~FASYNC; return error; } /* * When you add any new common ioctls to the switches above and below * please update compat_sys_ioctl() too. * * do_vfs_ioctl() is not for drivers and not intended to be EXPORT_SYMBOL()'d. * It's just a simple helper for sys_ioctl and compat_sys_ioctl. */ int do_vfs_ioctl(struct file *filp, unsigned int fd, unsigned int cmd, unsigned long arg) { int error = 0; int __user *argp = (int __user *)arg; switch (cmd) { case FIOCLEX: set_close_on_exec(fd, 1); break; case FIONCLEX: set_close_on_exec(fd, 0); break; case FIONBIO: error = ioctl_fionbio(filp, argp); break; case FIOASYNC: error = ioctl_fioasync(fd, filp, argp); break; case FIOQSIZE: if (S_ISDIR(filp->f_path.dentry->d_inode->i_mode) || S_ISREG(filp->f_path.dentry->d_inode->i_mode) || S_ISLNK(filp->f_path.dentry->d_inode->i_mode)) { loff_t res = inode_get_bytes(filp->f_path.dentry->d_inode); error = copy_to_user((loff_t __user *)arg, &res, sizeof(res)) ? -EFAULT : 0; } else error = -ENOTTY; break; default: if (S_ISREG(filp->f_path.dentry->d_inode->i_mode)) error = file_ioctl(filp, cmd, arg); else error = vfs_ioctl(filp, cmd, arg); break; } return error; } asmlinkage long sys_ioctl(unsigned int fd, unsigned int cmd, unsigned long arg) { struct file *filp; int error = -EBADF; int fput_needed; filp = fget_light(fd, &fput_needed); if (!filp) goto out; error = security_file_ioctl(filp, cmd, arg); if (error) goto out_fput; error = do_vfs_ioctl(filp, fd, cmd, arg); out_fput: fput_light(filp, fput_needed); out: return error; } |