1 /* $NetBSD: linux32_dirent.c,v 1.12 2010/09/11 20:53:04 chs 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 1.12 2010/09/11 20:53:04 chs 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 if ((error = VOP_GETATTR(vp, &va, l->l_cred))) 134 goto out1; 135 136 nbytes = SCARG(uap, count); 137 if (nbytes == 1) { /* emulating old, broken behaviour */ 138 nbytes = sizeof (idb); 139 buflen = max(va.va_blocksize, nbytes); 140 oldcall = 1; 141 } else { 142 buflen = min(MAXBSIZE, nbytes); 143 if (buflen < va.va_blocksize) 144 buflen = va.va_blocksize; 145 oldcall = 0; 146 } 147 tbuf = malloc(buflen, M_TEMP, M_WAITOK); 148 149 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 150 off = fp->f_offset; 151 again: 152 aiov.iov_base = tbuf; 153 aiov.iov_len = buflen; 154 auio.uio_iov = &aiov; 155 auio.uio_iovcnt = 1; 156 auio.uio_rw = UIO_READ; 157 auio.uio_resid = buflen; 158 auio.uio_offset = off; 159 UIO_SETUP_SYSSPACE(&auio); 160 /* 161 * First we read into the malloc'ed buffer, then 162 * we massage it into user space, one record at a time. 163 */ 164 error = VOP_READDIR(vp, &auio, fp->f_cred, &eofflag, &cookiebuf, 165 &ncookies); 166 if (error) 167 goto out; 168 169 inp = tbuf; 170 outp = (void *)SCARG_P32(uap, dent); 171 resid = nbytes; 172 if ((len = buflen - auio.uio_resid) == 0) 173 goto eof; 174 175 for (cookie = cookiebuf; len > 0; len -= reclen) { 176 bdp = (struct dirent *)inp; 177 reclen = bdp->d_reclen; 178 if (reclen & 3) 179 panic("linux32_readdir"); 180 if (bdp->d_fileno == 0) { 181 inp += reclen; /* it is a hole; squish it out */ 182 if (cookie) 183 off = *cookie++; 184 else 185 off += reclen; 186 continue; 187 } 188 linux32_reclen = LINUX_RECLEN(&idb, bdp->d_namlen); 189 if (reclen > len || resid < linux32_reclen) { 190 /* entry too big for buffer, so just stop */ 191 outp++; 192 break; 193 } 194 /* 195 * Massage in place to make a Linux-shaped dirent (otherwise 196 * we have to worry about touching user memory outside of 197 * the copyout() call). 198 */ 199 idb.d_ino = bdp->d_fileno; 200 /* 201 * The old readdir() call misuses the offset and reclen fields. 202 */ 203 if (oldcall) { 204 idb.d_off = (linux32_off_t)linux32_reclen; 205 idb.d_reclen = (u_short)bdp->d_namlen; 206 } else { 207 if (sizeof (idb.d_off) <= 4 && (off >> 32) != 0) { 208 compat_offseterr(vp, "linux32_getdents"); 209 error = EINVAL; 210 goto out; 211 } 212 idb.d_off = (linux32_off_t)off; 213 idb.d_reclen = (u_short)linux32_reclen; 214 } 215 strcpy(idb.d_name, bdp->d_name); 216 idb.d_name[strlen(idb.d_name) + 1] = bdp->d_type; 217 if ((error = copyout((void *)&idb, outp, linux32_reclen))) 218 goto out; 219 /* advance past this real entry */ 220 inp += reclen; 221 if (cookie) 222 off = *cookie++; /* each entry points to itself */ 223 else 224 off += reclen; 225 /* advance output past Linux-shaped entry */ 226 outp += linux32_reclen; 227 resid -= linux32_reclen; 228 if (oldcall) 229 break; 230 } 231 232 /* if we squished out the whole block, try again */ 233 if (outp == (void *)SCARG_P32(uap, dent)) { 234 if (cookiebuf) 235 free(cookiebuf, M_TEMP); 236 cookiebuf = NULL; 237 goto again; 238 } 239 fp->f_offset = off; /* update the vnode offset */ 240 241 if (oldcall) 242 nbytes = resid + linux32_reclen; 243 244 eof: 245 *retval = nbytes - resid; 246 out: 247 VOP_UNLOCK(vp); 248 if (cookiebuf) 249 free(cookiebuf, M_TEMP); 250 free(tbuf, M_TEMP); 251 out1: 252 fd_putfile(SCARG(uap, fd)); 253 return error; 254 } 255 256 int 257 linux32_sys_getdents64(struct lwp *l, const struct linux32_sys_getdents64_args *uap, register_t *retval) 258 { 259 /* { 260 syscallarg(int) fd; 261 syscallarg(linux32_dirent64p_t) dent; 262 syscallarg(unsigned int) count; 263 } */ 264 struct linux_sys_getdents64_args ua; 265 266 NETBSD32TO64_UAP(fd); 267 NETBSD32TOP_UAP(dent, struct linux_dirent64); 268 NETBSD32TO64_UAP(count); 269 270 return linux_sys_getdents64(l, &ua, retval); 271 } 272 273 int 274 linux32_sys_readdir(struct lwp *l, const struct linux32_sys_readdir_args *uap, register_t *retval) 275 { 276 /* { 277 syscallarg(int) fd; 278 syscallarg(struct linux32_direntp_t) dent; 279 syscallarg(unsigned int) count; 280 } */ 281 int error; 282 struct linux32_sys_getdents_args da; 283 284 SCARG(&da, fd) = SCARG(uap, fd); 285 SCARG(&da, dent) = SCARG(uap, dent); 286 SCARG(&da, count) = 1; 287 288 error = linux32_sys_getdents(l, &da, retval); 289 if (error == 0 && *retval > 1) 290 *retval = 1; 291 292 return error; 293 } 294