/* $NetBSD: linux32_dirent.c,v 1.19.4.1 2019/09/13 06:25:25 martin Exp $ */ /*- * Copyright (c) 2006 Emmanuel Dreyfus, all rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. All advertising materials mentioning features or use of this software * must display the following acknowledgement: * This product includes software developed by Emmanuel Dreyfus * 4. The name of the author may not be used to endorse or promote * products derived from this software without specific prior written * permission. * * THIS SOFTWARE IS PROVIDED BY THE THE AUTHOR AND CONTRIBUTORS ``AS IS'' * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE * POSSIBILITY OF SUCH DAMAGE. */ #include __KERNEL_RCSID(0, "$NetBSD: linux32_dirent.c,v 1.19.4.1 2019/09/13 06:25:25 martin Exp $"); #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include /* * Linux 'readdir' call. This code is mostly taken from the * SunOS getdents call (see compat/sunos/sunos_misc.c), though * an attempt has been made to keep it a little cleaner (failing * miserably, because of the cruft needed if count 1 is passed). * * The d_off field should contain the offset of the next valid entry, * but in Linux it has the offset of the entry itself. We emulate * that bug here. * * Read in BSD-style entries, convert them, and copy them out. * * Note that this doesn't handle union-mounted filesystems. */ int linux32_sys_getdents(struct lwp *l, const struct linux32_sys_getdents_args *uap, register_t *retval) { /* { syscallarg(int) fd; syscallarg(linux32_direntp_t) dent; syscallarg(unsigned int) count; } */ struct dirent *bdp; struct vnode *vp; char *inp, *tbuf; /* BSD-format */ int len, reclen; /* BSD-format */ char *outp; /* Linux-format */ int resid, linux32_reclen = 0; /* Linux-format */ struct file *fp; struct uio auio; struct iovec aiov; struct linux32_dirent idb; off_t off; /* true file offset */ int buflen, error, eofflag, nbytes, oldcall; struct vattr va; off_t *cookiebuf = NULL, *cookie; int ncookies; /* fd_getvnode() will use the descriptor for us */ if ((error = fd_getvnode(SCARG(uap, fd), &fp)) != 0) return (error); if ((fp->f_flag & FREAD) == 0) { error = EBADF; goto out1; } vp = (struct vnode *)fp->f_data; if (vp->v_type != VDIR) { error = ENOTDIR; goto out1; } vn_lock(vp, LK_SHARED | LK_RETRY); error = VOP_GETATTR(vp, &va, l->l_cred); VOP_UNLOCK(vp); if (error) goto out1; nbytes = SCARG(uap, count); if (nbytes == 1) { /* emulating old, broken behaviour */ nbytes = sizeof (idb); buflen = uimax(va.va_blocksize, nbytes); oldcall = 1; } else { buflen = uimin(MAXBSIZE, nbytes); if (buflen < va.va_blocksize) buflen = va.va_blocksize; oldcall = 0; } tbuf = malloc(buflen, M_TEMP, M_WAITOK); vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); off = fp->f_offset; again: aiov.iov_base = tbuf; aiov.iov_len = buflen; auio.uio_iov = &aiov; auio.uio_iovcnt = 1; auio.uio_rw = UIO_READ; auio.uio_resid = buflen; auio.uio_offset = off; UIO_SETUP_SYSSPACE(&auio); /* * First we read into the malloc'ed buffer, then * we massage it into user space, one record at a time. */ error = VOP_READDIR(vp, &auio, fp->f_cred, &eofflag, &cookiebuf, &ncookies); if (error) goto out; inp = tbuf; outp = (void *)SCARG_P32(uap, dent); resid = nbytes; if ((len = buflen - auio.uio_resid) == 0) goto eof; for (cookie = cookiebuf; len > 0; len -= reclen) { bdp = (struct dirent *)inp; reclen = bdp->d_reclen; if (reclen & 3) { error = EIO; goto out; } if (bdp->d_fileno == 0) { inp += reclen; /* it is a hole; squish it out */ if (cookie) off = *cookie++; else off += reclen; continue; } linux32_reclen = LINUX_RECLEN(&idb, bdp->d_namlen); if (reclen > len || resid < linux32_reclen) { /* entry too big for buffer, so just stop */ outp++; break; } /* * Massage in place to make a Linux-shaped dirent (otherwise * we have to worry about touching user memory outside of * the copyout() call). */ memset(&idb, 0, sizeof(idb)); idb.d_ino = bdp->d_fileno; /* * The old readdir() call misuses the offset and reclen fields. */ if (oldcall) { idb.d_off = (linux32_off_t)linux32_reclen; idb.d_reclen = (u_short)bdp->d_namlen; } else { if (sizeof (idb.d_off) <= 4 && (off >> 32) != 0) { compat_offseterr(vp, "linux32_getdents"); error = EINVAL; goto out; } idb.d_off = (linux32_off_t)off; idb.d_reclen = (u_short)linux32_reclen; } size_t dirl = MIN(sizeof(idb.d_name) - 1, bdp->d_namlen + 1); memcpy(idb.d_name, bdp->d_name, dirl); idb.d_name[dirl + 1] = bdp->d_type; if ((error = copyout((void *)&idb, outp, linux32_reclen))) goto out; /* advance past this real entry */ inp += reclen; if (cookie) off = *cookie++; /* each entry points to itself */ else off += reclen; /* advance output past Linux-shaped entry */ outp += linux32_reclen; resid -= linux32_reclen; if (oldcall) break; } /* if we squished out the whole block, try again */ if (outp == (void *)SCARG_P32(uap, dent)) { if (cookiebuf) free(cookiebuf, M_TEMP); cookiebuf = NULL; goto again; } fp->f_offset = off; /* update the vnode offset */ if (oldcall) nbytes = resid + linux32_reclen; eof: *retval = nbytes - resid; out: VOP_UNLOCK(vp); if (cookiebuf) free(cookiebuf, M_TEMP); free(tbuf, M_TEMP); out1: fd_putfile(SCARG(uap, fd)); return error; } int linux32_sys_getdents64(struct lwp *l, const struct linux32_sys_getdents64_args *uap, register_t *retval) { /* { syscallarg(int) fd; syscallarg(linux32_dirent64p_t) dent; syscallarg(unsigned int) count; } */ struct linux_sys_getdents64_args ua; NETBSD32TO64_UAP(fd); NETBSD32TOP_UAP(dent, struct linux_dirent64); NETBSD32TO64_UAP(count); return linux_sys_getdents64(l, &ua, retval); } int linux32_sys_readdir(struct lwp *l, const struct linux32_sys_readdir_args *uap, register_t *retval) { /* { syscallarg(int) fd; syscallarg(struct linux32_direntp_t) dent; syscallarg(unsigned int) count; } */ int error; struct linux32_sys_getdents_args da; SCARG(&da, fd) = SCARG(uap, fd); SCARG(&da, dent) = SCARG(uap, dent); SCARG(&da, count) = 1; error = linux32_sys_getdents(l, &da, retval); if (error == 0 && *retval > 1) *retval = 1; return error; }