1 /* $NetBSD: linux32_dirent.c,v 1.20 2019/08/23 07:53:36 maxv 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 1.20 2019/08/23 07:53:36 maxv 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 = uimax(va.va_blocksize, nbytes); 143 oldcall = 1; 144 } else { 145 buflen = uimin(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 error = EIO; 183 goto out; 184 } 185 if (bdp->d_fileno == 0) { 186 inp += reclen; /* it is a hole; squish it out */ 187 if (cookie) 188 off = *cookie++; 189 else 190 off += reclen; 191 continue; 192 } 193 linux32_reclen = LINUX_RECLEN(&idb, bdp->d_namlen); 194 if (reclen > len || resid < linux32_reclen) { 195 /* entry too big for buffer, so just stop */ 196 outp++; 197 break; 198 } 199 /* 200 * Massage in place to make a Linux-shaped dirent (otherwise 201 * we have to worry about touching user memory outside of 202 * the copyout() call). 203 */ 204 memset(&idb, 0, sizeof(idb)); 205 idb.d_ino = bdp->d_fileno; 206 /* 207 * The old readdir() call misuses the offset and reclen fields. 208 */ 209 if (oldcall) { 210 idb.d_off = (linux32_off_t)linux32_reclen; 211 idb.d_reclen = (u_short)bdp->d_namlen; 212 } else { 213 if (sizeof (idb.d_off) <= 4 && (off >> 32) != 0) { 214 compat_offseterr(vp, "linux32_getdents"); 215 error = EINVAL; 216 goto out; 217 } 218 idb.d_off = (linux32_off_t)off; 219 idb.d_reclen = (u_short)linux32_reclen; 220 } 221 size_t dirl = MIN(sizeof(idb.d_name) - 1, bdp->d_namlen + 1); 222 memcpy(idb.d_name, bdp->d_name, dirl); 223 idb.d_name[dirl + 1] = bdp->d_type; 224 if ((error = copyout((void *)&idb, outp, linux32_reclen))) 225 goto out; 226 /* advance past this real entry */ 227 inp += reclen; 228 if (cookie) 229 off = *cookie++; /* each entry points to itself */ 230 else 231 off += reclen; 232 /* advance output past Linux-shaped entry */ 233 outp += linux32_reclen; 234 resid -= linux32_reclen; 235 if (oldcall) 236 break; 237 } 238 239 /* if we squished out the whole block, try again */ 240 if (outp == (void *)SCARG_P32(uap, dent)) { 241 if (cookiebuf) 242 free(cookiebuf, M_TEMP); 243 cookiebuf = NULL; 244 goto again; 245 } 246 fp->f_offset = off; /* update the vnode offset */ 247 248 if (oldcall) 249 nbytes = resid + linux32_reclen; 250 251 eof: 252 *retval = nbytes - resid; 253 out: 254 VOP_UNLOCK(vp); 255 if (cookiebuf) 256 free(cookiebuf, M_TEMP); 257 free(tbuf, M_TEMP); 258 out1: 259 fd_putfile(SCARG(uap, fd)); 260 return error; 261 } 262 263 int 264 linux32_sys_getdents64(struct lwp *l, const struct linux32_sys_getdents64_args *uap, register_t *retval) 265 { 266 /* { 267 syscallarg(int) fd; 268 syscallarg(linux32_dirent64p_t) dent; 269 syscallarg(unsigned int) count; 270 } */ 271 struct linux_sys_getdents64_args ua; 272 273 NETBSD32TO64_UAP(fd); 274 NETBSD32TOP_UAP(dent, struct linux_dirent64); 275 NETBSD32TO64_UAP(count); 276 277 return linux_sys_getdents64(l, &ua, retval); 278 } 279 280 int 281 linux32_sys_readdir(struct lwp *l, const struct linux32_sys_readdir_args *uap, register_t *retval) 282 { 283 /* { 284 syscallarg(int) fd; 285 syscallarg(struct linux32_direntp_t) dent; 286 syscallarg(unsigned int) count; 287 } */ 288 int error; 289 struct linux32_sys_getdents_args da; 290 291 SCARG(&da, fd) = SCARG(uap, fd); 292 SCARG(&da, dent) = SCARG(uap, dent); 293 SCARG(&da, count) = 1; 294 295 error = linux32_sys_getdents(l, &da, retval); 296 if (error == 0 && *retval > 1) 297 *retval = 1; 298 299 return error; 300 } 301
Indexes created Sun Sep 21 20:09:37 GMT 2025