| 1 | /* $NetBSD: linux32_dirent.c,v 1.13 2011/10/14 09:23:29 hannken Exp $ */ |
| 2 | |
| 3 | /*- |
| 4 | * Copyright (c) 2006 Emmanuel Dreyfus, all rights reserved. |
| 5 | * |
| 6 | * Redistribution and use in source and binary forms, with or without |
| 7 | * modification, are permitted provided that the following conditions |
| 8 | * are met: |
| 9 | * 1. Redistributions of source code must retain the above copyright |
| 10 | * notice, this list of conditions and the following disclaimer. |
| 11 | * 2. Redistributions in binary form must reproduce the above copyright |
| 12 | * notice, this list of conditions and the following disclaimer in the |
| 13 | * documentation and/or other materials provided with the distribution. |
| 14 | * 3. All advertising materials mentioning features or use of this software |
| 15 | * must display the following acknowledgement: |
| 16 | * This product includes software developed by Emmanuel Dreyfus |
| 17 | * 4. The name of the author may not be used to endorse or promote |
| 18 | * products derived from this software without specific prior written |
| 19 | * permission. |
| 20 | * |
| 21 | * THIS SOFTWARE IS PROVIDED BY THE THE AUTHOR AND CONTRIBUTORS ``AS IS'' |
| 22 | * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, |
| 23 | * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR |
| 24 | * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS |
| 25 | * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR |
| 26 | * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF |
| 27 | * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS |
| 28 | * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN |
| 29 | * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) |
| 30 | * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE |
| 31 | * POSSIBILITY OF SUCH DAMAGE. |
| 32 | */ |
| 33 | |
| 34 | #include <sys/cdefs.h> |
| 35 | |
| 36 | __KERNEL_RCSID(0, "$NetBSD: linux32_dirent.c,v 1.13 2011/10/14 09:23:29 hannken Exp $" ); |
| 37 | |
| 38 | #include <sys/types.h> |
| 39 | #include <sys/param.h> |
| 40 | #include <sys/fstypes.h> |
| 41 | #include <sys/signal.h> |
| 42 | #include <sys/dirent.h> |
| 43 | #include <sys/kernel.h> |
| 44 | #include <sys/fcntl.h> |
| 45 | #include <sys/file.h> |
| 46 | #include <sys/filedesc.h> |
| 47 | #include <sys/malloc.h> |
| 48 | #include <sys/select.h> |
| 49 | #include <sys/proc.h> |
| 50 | #include <sys/ucred.h> |
| 51 | #include <sys/vnode.h> |
| 52 | #include <sys/swap.h> |
| 53 | |
| 54 | #include <machine/types.h> |
| 55 | |
| 56 | #include <sys/syscallargs.h> |
| 57 | |
| 58 | #include <compat/netbsd32/netbsd32.h> |
| 59 | #include <compat/netbsd32/netbsd32_conv.h> |
| 60 | #include <compat/netbsd32/netbsd32_syscallargs.h> |
| 61 | |
| 62 | #include <compat/linux/common/linux_types.h> |
| 63 | #include <compat/linux/common/linux_signal.h> |
| 64 | #include <compat/linux/common/linux_machdep.h> |
| 65 | #include <compat/linux/common/linux_misc.h> |
| 66 | #include <compat/linux/common/linux_oldolduname.h> |
| 67 | #include <compat/linux/common/linux_dirent.h> |
| 68 | #include <compat/linux/common/linux_ipc.h> |
| 69 | #include <compat/linux/common/linux_sem.h> |
| 70 | #include <compat/linux/linux_syscallargs.h> |
| 71 | |
| 72 | #include <compat/linux32/common/linux32_types.h> |
| 73 | #include <compat/linux32/common/linux32_signal.h> |
| 74 | #include <compat/linux32/common/linux32_machdep.h> |
| 75 | #include <compat/linux32/common/linux32_sysctl.h> |
| 76 | #include <compat/linux32/common/linux32_socketcall.h> |
| 77 | #include <compat/linux32/linux32_syscallargs.h> |
| 78 | |
| 79 | /* |
| 80 | * Linux 'readdir' call. This code is mostly taken from the |
| 81 | * SunOS getdents call (see compat/sunos/sunos_misc.c), though |
| 82 | * an attempt has been made to keep it a little cleaner (failing |
| 83 | * miserably, because of the cruft needed if count 1 is passed). |
| 84 | * |
| 85 | * The d_off field should contain the offset of the next valid entry, |
| 86 | * but in Linux it has the offset of the entry itself. We emulate |
| 87 | * that bug here. |
| 88 | * |
| 89 | * Read in BSD-style entries, convert them, and copy them out. |
| 90 | * |
| 91 | * Note that this doesn't handle union-mounted filesystems. |
| 92 | */ |
| 93 | |
| 94 | int |
| 95 | linux32_sys_getdents(struct lwp *l, const struct linux32_sys_getdents_args *uap, register_t *retval) |
| 96 | { |
| 97 | /* { |
| 98 | syscallarg(int) fd; |
| 99 | syscallarg(linux32_direntp_t) dent; |
| 100 | syscallarg(unsigned int) count; |
| 101 | } */ |
| 102 | struct dirent *bdp; |
| 103 | struct vnode *vp; |
| 104 | char *inp, *tbuf; /* BSD-format */ |
| 105 | int len, reclen; /* BSD-format */ |
| 106 | char *outp; /* Linux-format */ |
| 107 | int resid, linux32_reclen = 0; /* Linux-format */ |
| 108 | struct file *fp; |
| 109 | struct uio auio; |
| 110 | struct iovec aiov; |
| 111 | struct linux32_dirent idb; |
| 112 | off_t off; /* true file offset */ |
| 113 | int buflen, error, eofflag, nbytes, oldcall; |
| 114 | struct vattr va; |
| 115 | off_t *cookiebuf = NULL, *cookie; |
| 116 | int ncookies; |
| 117 | |
| 118 | /* fd_getvnode() will use the descriptor for us */ |
| 119 | if ((error = fd_getvnode(SCARG(uap, fd), &fp)) != 0) |
| 120 | return (error); |
| 121 | |
| 122 | if ((fp->f_flag & FREAD) == 0) { |
| 123 | error = EBADF; |
| 124 | goto out1; |
| 125 | } |
| 126 | |
| 127 | vp = (struct vnode *)fp->f_data; |
| 128 | if (vp->v_type != VDIR) { |
| 129 | error = ENOTDIR; |
| 130 | goto out1; |
| 131 | } |
| 132 | |
| 133 | vn_lock(vp, LK_SHARED | LK_RETRY); |
| 134 | error = VOP_GETATTR(vp, &va, l->l_cred); |
| 135 | VOP_UNLOCK(vp); |
| 136 | if (error) |
| 137 | goto out1; |
| 138 | |
| 139 | nbytes = SCARG(uap, count); |
| 140 | if (nbytes == 1) { /* emulating old, broken behaviour */ |
| 141 | nbytes = sizeof (idb); |
| 142 | buflen = max(va.va_blocksize, nbytes); |
| 143 | oldcall = 1; |
| 144 | } else { |
| 145 | buflen = min(MAXBSIZE, nbytes); |
| 146 | if (buflen < va.va_blocksize) |
| 147 | buflen = va.va_blocksize; |
| 148 | oldcall = 0; |
| 149 | } |
| 150 | tbuf = malloc(buflen, M_TEMP, M_WAITOK); |
| 151 | |
| 152 | vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); |
| 153 | off = fp->f_offset; |
| 154 | again: |
| 155 | aiov.iov_base = tbuf; |
| 156 | aiov.iov_len = buflen; |
| 157 | auio.uio_iov = &aiov; |
| 158 | auio.uio_iovcnt = 1; |
| 159 | auio.uio_rw = UIO_READ; |
| 160 | auio.uio_resid = buflen; |
| 161 | auio.uio_offset = off; |
| 162 | UIO_SETUP_SYSSPACE(&auio); |
| 163 | /* |
| 164 | * First we read into the malloc'ed buffer, then |
| 165 | * we massage it into user space, one record at a time. |
| 166 | */ |
| 167 | error = VOP_READDIR(vp, &auio, fp->f_cred, &eofflag, &cookiebuf, |
| 168 | &ncookies); |
| 169 | if (error) |
| 170 | goto out; |
| 171 | |
| 172 | inp = tbuf; |
| 173 | outp = (void *)SCARG_P32(uap, dent); |
| 174 | resid = nbytes; |
| 175 | if ((len = buflen - auio.uio_resid) == 0) |
| 176 | goto eof; |
| 177 | |
| 178 | for (cookie = cookiebuf; len > 0; len -= reclen) { |
| 179 | bdp = (struct dirent *)inp; |
| 180 | reclen = bdp->d_reclen; |
| 181 | if (reclen & 3) |
| 182 | panic("linux32_readdir" ); |
| 183 | if (bdp->d_fileno == 0) { |
| 184 | inp += reclen; /* it is a hole; squish it out */ |
| 185 | if (cookie) |
| 186 | off = *cookie++; |
| 187 | else |
| 188 | off += reclen; |
| 189 | continue; |
| 190 | } |
| 191 | linux32_reclen = LINUX_RECLEN(&idb, bdp->d_namlen); |
| 192 | if (reclen > len || resid < linux32_reclen) { |
| 193 | /* entry too big for buffer, so just stop */ |
| 194 | outp++; |
| 195 | break; |
| 196 | } |
| 197 | /* |
| 198 | * Massage in place to make a Linux-shaped dirent (otherwise |
| 199 | * we have to worry about touching user memory outside of |
| 200 | * the copyout() call). |
| 201 | */ |
| 202 | idb.d_ino = bdp->d_fileno; |
| 203 | /* |
| 204 | * The old readdir() call misuses the offset and reclen fields. |
| 205 | */ |
| 206 | if (oldcall) { |
| 207 | idb.d_off = (linux32_off_t)linux32_reclen; |
| 208 | idb.d_reclen = (u_short)bdp->d_namlen; |
| 209 | } else { |
| 210 | if (sizeof (idb.d_off) <= 4 && (off >> 32) != 0) { |
| 211 | compat_offseterr(vp, "linux32_getdents" ); |
| 212 | error = EINVAL; |
| 213 | goto out; |
| 214 | } |
| 215 | idb.d_off = (linux32_off_t)off; |
| 216 | idb.d_reclen = (u_short)linux32_reclen; |
| 217 | } |
| 218 | strcpy(idb.d_name, bdp->d_name); |
| 219 | idb.d_name[strlen(idb.d_name) + 1] = bdp->d_type; |
| 220 | if ((error = copyout((void *)&idb, outp, linux32_reclen))) |
| 221 | goto out; |
| 222 | /* advance past this real entry */ |
| 223 | inp += reclen; |
| 224 | if (cookie) |
| 225 | off = *cookie++; /* each entry points to itself */ |
| 226 | else |
| 227 | off += reclen; |
| 228 | /* advance output past Linux-shaped entry */ |
| 229 | outp += linux32_reclen; |
| 230 | resid -= linux32_reclen; |
| 231 | if (oldcall) |
| 232 | break; |
| 233 | } |
| 234 | |
| 235 | /* if we squished out the whole block, try again */ |
| 236 | if (outp == (void *)SCARG_P32(uap, dent)) { |
| 237 | if (cookiebuf) |
| 238 | free(cookiebuf, M_TEMP); |
| 239 | cookiebuf = NULL; |
| 240 | goto again; |
| 241 | } |
| 242 | fp->f_offset = off; /* update the vnode offset */ |
| 243 | |
| 244 | if (oldcall) |
| 245 | nbytes = resid + linux32_reclen; |
| 246 | |
| 247 | eof: |
| 248 | *retval = nbytes - resid; |
| 249 | out: |
| 250 | VOP_UNLOCK(vp); |
| 251 | if (cookiebuf) |
| 252 | free(cookiebuf, M_TEMP); |
| 253 | free(tbuf, M_TEMP); |
| 254 | out1: |
| 255 | fd_putfile(SCARG(uap, fd)); |
| 256 | return error; |
| 257 | } |
| 258 | |
| 259 | int |
| 260 | linux32_sys_getdents64(struct lwp *l, const struct linux32_sys_getdents64_args *uap, register_t *retval) |
| 261 | { |
| 262 | /* { |
| 263 | syscallarg(int) fd; |
| 264 | syscallarg(linux32_dirent64p_t) dent; |
| 265 | syscallarg(unsigned int) count; |
| 266 | } */ |
| 267 | struct linux_sys_getdents64_args ua; |
| 268 | |
| 269 | NETBSD32TO64_UAP(fd); |
| 270 | NETBSD32TOP_UAP(dent, struct linux_dirent64); |
| 271 | NETBSD32TO64_UAP(count); |
| 272 | |
| 273 | return linux_sys_getdents64(l, &ua, retval); |
| 274 | } |
| 275 | |
| 276 | int |
| 277 | linux32_sys_readdir(struct lwp *l, const struct linux32_sys_readdir_args *uap, register_t *retval) |
| 278 | { |
| 279 | /* { |
| 280 | syscallarg(int) fd; |
| 281 | syscallarg(struct linux32_direntp_t) dent; |
| 282 | syscallarg(unsigned int) count; |
| 283 | } */ |
| 284 | int error; |
| 285 | struct linux32_sys_getdents_args da; |
| 286 | |
| 287 | SCARG(&da, fd) = SCARG(uap, fd); |
| 288 | SCARG(&da, dent) = SCARG(uap, dent); |
| 289 | SCARG(&da, count) = 1; |
| 290 | |
| 291 | error = linux32_sys_getdents(l, &da, retval); |
| 292 | if (error == 0 && *retval > 1) |
| 293 | *retval = 1; |
| 294 | |
| 295 | return error; |
| 296 | } |
| 297 | |