linux32_dirent.c revision 1.6
1 /* $NetBSD: linux32_dirent.c,v 1.6 2008/09/04 17:45:00 njoly 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 1.6 2008/09/04 17:45:00 njoly 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/linux_syscallargs.h> 69 70 #include <compat/linux32/common/linux32_types.h> 71 #include <compat/linux32/common/linux32_signal.h> 72 #include <compat/linux32/common/linux32_machdep.h> 73 #include <compat/linux32/common/linux32_sysctl.h> 74 #include <compat/linux32/common/linux32_socketcall.h> 75 #include <compat/linux32/linux32_syscallargs.h> 76 77 /* 78 * Linux 'readdir' call. This code is mostly taken from the 79 * SunOS getdents call (see compat/sunos/sunos_misc.c), though 80 * an attempt has been made to keep it a little cleaner (failing 81 * miserably, because of the cruft needed if count 1 is passed). 82 * 83 * The d_off field should contain the offset of the next valid entry, 84 * but in Linux it has the offset of the entry itself. We emulate 85 * that bug here. 86 * 87 * Read in BSD-style entries, convert them, and copy them out. 88 * 89 * Note that this doesn't handle union-mounted filesystems. 90 */ 91 92 int 93 linux32_sys_getdents(struct lwp *l, const struct linux32_sys_getdents_args *uap, register_t *retval) 94 { 95 /* { 96 syscallarg(int) fd; 97 syscallarg(linux32_direntp_t) dent; 98 syscallarg(unsigned int) count; 99 } */ 100 struct dirent *bdp; 101 struct vnode *vp; 102 char *inp, *tbuf; /* BSD-format */ 103 int len, reclen; /* BSD-format */ 104 char *outp; /* Linux-format */ 105 int resid, linux32_reclen = 0; /* Linux-format */ 106 struct file *fp; 107 struct uio auio; 108 struct iovec aiov; 109 struct linux32_dirent idb; 110 off_t off; /* true file offset */ 111 int buflen, error, eofflag, nbytes, oldcall; 112 struct vattr va; 113 off_t *cookiebuf = NULL, *cookie; 114 int ncookies; 115 116 /* fd_getvnode() will use the descriptor for us */ 117 if ((error = fd_getvnode(SCARG(uap, fd), &fp)) != 0) 118 return (error); 119 120 if ((fp->f_flag & FREAD) == 0) { 121 error = EBADF; 122 goto out1; 123 } 124 125 vp = (struct vnode *)fp->f_data; 126 if (vp->v_type != VDIR) { 127 error = EINVAL; 128 goto out1; 129 } 130 131 if ((error = VOP_GETATTR(vp, &va, l->l_cred))) 132 goto out1; 133 134 nbytes = SCARG(uap, count); 135 if (nbytes == 1) { /* emulating old, broken behaviour */ 136 nbytes = sizeof (idb); 137 buflen = max(va.va_blocksize, nbytes); 138 oldcall = 1; 139 } else { 140 buflen = min(MAXBSIZE, nbytes); 141 if (buflen < va.va_blocksize) 142 buflen = va.va_blocksize; 143 oldcall = 0; 144 } 145 tbuf = malloc(buflen, M_TEMP, M_WAITOK); 146 147 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 148 off = fp->f_offset; 149 again: 150 aiov.iov_base = tbuf; 151 aiov.iov_len = buflen; 152 auio.uio_iov = &aiov; 153 auio.uio_iovcnt = 1; 154 auio.uio_rw = UIO_READ; 155 auio.uio_resid = buflen; 156 auio.uio_offset = off; 157 UIO_SETUP_SYSSPACE(&auio); 158 /* 159 * First we read into the malloc'ed buffer, then 160 * we massage it into user space, one record at a time. 161 */ 162 error = VOP_READDIR(vp, &auio, fp->f_cred, &eofflag, &cookiebuf, 163 &ncookies); 164 if (error) 165 goto out; 166 167 inp = tbuf; 168 outp = (void *)SCARG_P32(uap, dent); 169 resid = nbytes; 170 if ((len = buflen - auio.uio_resid) == 0) 171 goto eof; 172 173 for (cookie = cookiebuf; len > 0; len -= reclen) { 174 bdp = (struct dirent *)inp; 175 reclen = bdp->d_reclen; 176 if (reclen & 3) 177 panic("linux32_readdir"); 178 if (bdp->d_fileno == 0) { 179 inp += reclen; /* it is a hole; squish it out */ 180 if (cookie) 181 off = *cookie++; 182 else 183 off += reclen; 184 continue; 185 } 186 linux32_reclen = LINUX_RECLEN(&idb, bdp->d_namlen); 187 if (reclen > len || resid < linux32_reclen) { 188 /* entry too big for buffer, so just stop */ 189 outp++; 190 break; 191 } 192 /* 193 * Massage in place to make a Linux-shaped dirent (otherwise 194 * we have to worry about touching user memory outside of 195 * the copyout() call). 196 */ 197 idb.d_ino = bdp->d_fileno; 198 /* 199 * The old readdir() call misuses the offset and reclen fields. 200 */ 201 if (oldcall) { 202 idb.d_off = (linux32_off_t)linux32_reclen; 203 idb.d_reclen = (u_short)bdp->d_namlen; 204 } else { 205 if (sizeof (idb.d_off) <= 4 && (off >> 32) != 0) { 206 compat_offseterr(vp, "linux32_getdents"); 207 error = EINVAL; 208 goto out; 209 } 210 idb.d_off = (linux32_off_t)off; 211 idb.d_reclen = (u_short)linux32_reclen; 212 } 213 strcpy(idb.d_name, bdp->d_name); 214 if ((error = copyout((void *)&idb, outp, linux32_reclen))) 215 goto out; 216 /* advance past this real entry */ 217 inp += reclen; 218 if (cookie) 219 off = *cookie++; /* each entry points to itself */ 220 else 221 off += reclen; 222 /* advance output past Linux-shaped entry */ 223 outp += linux32_reclen; 224 resid -= linux32_reclen; 225 if (oldcall) 226 break; 227 } 228 229 /* if we squished out the whole block, try again */ 230 if (outp == (void *)SCARG_P32(uap, dent)) 231 goto again; 232 fp->f_offset = off; /* update the vnode offset */ 233 234 if (oldcall) 235 nbytes = resid + linux32_reclen; 236 237 eof: 238 *retval = nbytes - resid; 239 out: 240 VOP_UNLOCK(vp, 0); 241 if (cookiebuf) 242 free(cookiebuf, M_TEMP); 243 free(tbuf, M_TEMP); 244 out1: 245 fd_putfile(SCARG(uap, fd)); 246 return error; 247 } 248 249 int 250 linux32_sys_getdents64(struct lwp *l, const struct linux32_sys_getdents64_args *uap, register_t *retval) 251 { 252 /* { 253 syscallcarg(int) fd; 254 syscallcarg(linux32_dirent64p_t) dent; 255 syscallcarg(unsigned int) count; 256 } */ 257 struct linux_sys_getdents64_args ua; 258 259 NETBSD32TO64_UAP(fd); 260 NETBSD32TOP_UAP(dent, struct linux_dirent64); 261 NETBSD32TO64_UAP(count); 262 263 return linux_sys_getdents64(l, &ua, retval); 264 } 265 266 int 267 linux32_sys_readdir(struct lwp *l, const struct linux32_sys_readdir_args *uap, register_t *retval) 268 { 269 /* { 270 syscallarg(int) fd; 271 syscallarg(struct linux32_direntp_t) dent; 272 syscallarg(unsigned int) count; 273 } */ 274 int error; 275 struct linux32_sys_getdents_args da; 276 277 SCARG(&da, fd) = SCARG(uap, fd); 278 SCARG(&da, dent) = SCARG(uap, dent); 279 SCARG(&da, count) = 1; 280 281 error = linux32_sys_getdents(l, &da, retval); 282 if (error == 0 && *retval > 1) 283 *retval = 1; 284 285 return error; 286 } 287
Indexes created Mon Sep 22 13:09:51 GMT 2025