/* $NetBSD: vfs_vnops.c,v 1.242 2023/07/10 02:31:55 christos Exp $ */ /*- * Copyright (c) 2009 The NetBSD Foundation, Inc. * All rights reserved. * * This code is derived from software contributed to The NetBSD Foundation * by Andrew Doran. * * 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. * * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. 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 FOUNDATION 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. */ /* * Copyright (c) 1982, 1986, 1989, 1993 * The Regents of the University of California. All rights reserved. * (c) UNIX System Laboratories, Inc. * All or some portions of this file are derived from material licensed * to the University of California by American Telephone and Telegraph * Co. or Unix System Laboratories, Inc. and are reproduced herein with * the permission of UNIX System Laboratories, Inc. * * 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. Neither the name of the University nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 REGENTS 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. * * @(#)vfs_vnops.c 8.14 (Berkeley) 6/15/95 */ #include __KERNEL_RCSID(0, "$NetBSD: vfs_vnops.c,v 1.242 2023/07/10 02:31:55 christos Exp $"); #include "veriexec.h" #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 #ifdef UNION #include #endif #ifndef COMPAT_ZERODEV #define COMPAT_ZERODEV(dev) (0) #endif int (*vn_union_readdir_hook)(struct vnode **, struct file *, struct lwp *); #include static int vn_read(file_t *fp, off_t *offset, struct uio *uio, kauth_cred_t cred, int flags); static int vn_write(file_t *fp, off_t *offset, struct uio *uio, kauth_cred_t cred, int flags); static int vn_closefile(file_t *fp); static int vn_poll(file_t *fp, int events); static int vn_fcntl(file_t *fp, u_int com, void *data); static int vn_statfile(file_t *fp, struct stat *sb); static int vn_ioctl(file_t *fp, u_long com, void *data); static int vn_mmap(struct file *, off_t *, size_t, int, int *, int *, struct uvm_object **, int *); static int vn_seek(struct file *, off_t, int, off_t *, int); static int vn_advlock(struct file *, void *, int, struct flock *, int); static int vn_fpathconf(struct file *, int, register_t *); static int vn_posix_fadvise(struct file *, off_t, off_t, int); static int vn_truncate(file_t *, off_t); const struct fileops vnops = { .fo_name = "vn", .fo_read = vn_read, .fo_write = vn_write, .fo_ioctl = vn_ioctl, .fo_fcntl = vn_fcntl, .fo_poll = vn_poll, .fo_stat = vn_statfile, .fo_close = vn_closefile, .fo_kqfilter = vn_kqfilter, .fo_restart = fnullop_restart, .fo_mmap = vn_mmap, .fo_seek = vn_seek, .fo_advlock = vn_advlock, .fo_fpathconf = vn_fpathconf, .fo_posix_fadvise = vn_posix_fadvise, .fo_truncate = vn_truncate, }; /* * Common code for vnode open operations. * Check permissions, and call the VOP_OPEN or VOP_CREATE routine. * * at_dvp is the directory for openat(), if any. * pb is the path. * nmode is additional namei flags, restricted to TRYEMULROOT and NOCHROOT. * fmode is the open flags, converted from O_* to F* * cmode is the creation file permissions. * * XXX shouldn't cmode be mode_t? * * On success produces either a locked vnode in *ret_vp, or NULL in * *ret_vp and a file descriptor number in *ret_fd. * * The caller may pass NULL for ret_fd (and ret_domove), in which case * EOPNOTSUPP will be produced in the cases that would otherwise return * a file descriptor. * * Note that callers that want no-follow behavior should pass * O_NOFOLLOW in fmode. Neither FOLLOW nor NOFOLLOW in nmode is * honored. */ int vn_open(struct vnode *at_dvp, struct pathbuf *pb, int nmode, int fmode, int cmode, struct vnode **ret_vp, bool *ret_domove, int *ret_fd) { struct nameidata nd; struct vnode *vp = NULL; struct lwp *l = curlwp; kauth_cred_t cred = l->l_cred; struct vattr va; int error; const char *pathstring; KASSERT((nmode & (TRYEMULROOT | NOCHROOT)) == nmode); KASSERT(ret_vp != NULL); KASSERT((ret_domove == NULL) == (ret_fd == NULL)); if ((fmode & (O_CREAT | O_DIRECTORY)) == (O_CREAT | O_DIRECTORY)) return EINVAL; NDINIT(&nd, LOOKUP, nmode, pb); if (at_dvp != NULL) NDAT(&nd, at_dvp); nd.ni_cnd.cn_flags &= TRYEMULROOT | NOCHROOT; if (fmode & O_CREAT) { nd.ni_cnd.cn_nameiop = CREATE; nd.ni_cnd.cn_flags |= LOCKPARENT | LOCKLEAF; if ((fmode & O_EXCL) == 0 && ((fmode & O_NOFOLLOW) == 0)) nd.ni_cnd.cn_flags |= FOLLOW; if ((fmode & O_EXCL) == 0) nd.ni_cnd.cn_flags |= NONEXCLHACK; } else { nd.ni_cnd.cn_nameiop = LOOKUP; nd.ni_cnd.cn_flags |= LOCKLEAF; if ((fmode & O_NOFOLLOW) == 0) nd.ni_cnd.cn_flags |= FOLLOW; } pathstring = pathbuf_stringcopy_get(nd.ni_pathbuf); if (pathstring == NULL) { return ENOMEM; } /* * When this "interface" was exposed to do_open() it used * to initialize l_dupfd to -newfd-1 (thus passing in the * new file handle number to use)... but nothing in the * kernel uses that value. So just send 0. */ l->l_dupfd = 0; error = namei(&nd); if (error) goto out; vp = nd.ni_vp; #if NVERIEXEC > 0 error = veriexec_openchk(l, nd.ni_vp, pathstring, fmode); if (error) { /* We have to release the locks ourselves */ /* * 20210604 dholland passing NONEXCLHACK means we can * get ni_dvp == NULL back if ni_vp exists, and we should * treat that like the non-O_CREAT case. */ if ((fmode & O_CREAT) != 0 && nd.ni_dvp != NULL) { if (vp == NULL) { vput(nd.ni_dvp); } else { VOP_ABORTOP(nd.ni_dvp, &nd.ni_cnd); if (nd.ni_dvp == nd.ni_vp) vrele(nd.ni_dvp); else vput(nd.ni_dvp); nd.ni_dvp = NULL; vput(vp); vp = NULL; } } else { vput(vp); vp = NULL; } goto out; } #endif /* NVERIEXEC > 0 */ /* * 20210604 dholland ditto */ if ((fmode & O_CREAT) != 0 && nd.ni_dvp != NULL) { if (nd.ni_vp == NULL) { vattr_null(&va); va.va_type = VREG; va.va_mode = cmode; if (fmode & O_EXCL) va.va_vaflags |= VA_EXCLUSIVE; error = VOP_CREATE(nd.ni_dvp, &nd.ni_vp, &nd.ni_cnd, &va); if (error) { vput(nd.ni_dvp); goto out; } fmode &= ~O_TRUNC; vp = nd.ni_vp; vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); vput(nd.ni_dvp); } else { VOP_ABORTOP(nd.ni_dvp, &nd.ni_cnd); if (nd.ni_dvp == nd.ni_vp) vrele(nd.ni_dvp); else vput(nd.ni_dvp); nd.ni_dvp = NULL; vp = nd.ni_vp; if (fmode & O_EXCL) { error = EEXIST; goto bad; } fmode &= ~O_CREAT; } } else if ((fmode & O_CREAT) != 0) { /* * 20210606 dholland passing NONEXCLHACK means this * case exists; it is the same as the following one * but also needs to do things in the second (exists) * half of the following block. (Besides handle * ni_dvp, anyway.) */ vp = nd.ni_vp; KASSERT((fmode & O_EXCL) == 0); fmode &= ~O_CREAT; } else { vp = nd.ni_vp; } if (vp->v_type == VSOCK) { error = EOPNOTSUPP; goto bad; } if (nd.ni_vp->v_type == VLNK) { error = EFTYPE; goto bad; } if ((fmode & O_CREAT) == 0) { error = vn_openchk(vp, cred, fmode); if (error != 0) goto bad; } if (fmode & O_TRUNC) { vattr_null(&va); va.va_size = 0; error = VOP_SETATTR(vp, &va, cred); if (error != 0) goto bad; } if ((error = VOP_OPEN(vp, fmode, cred)) != 0) goto bad; if (fmode & FWRITE) { mutex_enter(vp->v_interlock); vp->v_writecount++; mutex_exit(vp->v_interlock); } bad: if (error) { vput(vp); vp = NULL; } out: pathbuf_stringcopy_put(nd.ni_pathbuf, pathstring); switch (error) { case EDUPFD: case EMOVEFD: /* if the caller isn't prepared to handle fds, fail for them */ if (ret_fd == NULL) { error = EOPNOTSUPP; break; } *ret_vp = NULL; *ret_domove = error == EMOVEFD; *ret_fd = l->l_dupfd; error = 0; break; case 0: KASSERT(VOP_ISLOCKED(vp) == LK_EXCLUSIVE); *ret_vp = vp; break; } l->l_dupfd = 0; return error; } /* * Check for write permissions on the specified vnode. * Prototype text segments cannot be written. */ int vn_writechk(struct vnode *vp) { /* * If the vnode is in use as a process's text, * we can't allow writing. */ if (vp->v_iflag & VI_TEXT) return ETXTBSY; return 0; } int vn_openchk(struct vnode *vp, kauth_cred_t cred, int fflags) { int permbits = 0; int error; if (vp->v_type == VNON || vp->v_type == VBAD) return ENXIO; if ((fflags & O_DIRECTORY) != 0 && vp->v_type != VDIR) return ENOTDIR; if ((fflags & O_REGULAR) != 0 && vp->v_type != VREG) return EFTYPE; if ((fflags & FREAD) != 0) { permbits = VREAD; } if ((fflags & FEXEC) != 0) { permbits |= VEXEC; } if ((fflags & (FWRITE | O_TRUNC)) != 0) { permbits |= VWRITE; if (vp->v_type == VDIR) { error = EISDIR; goto bad; } error = vn_writechk(vp); if (error != 0) goto bad; } error = VOP_ACCESS(vp, permbits, cred); bad: return error; } /* * Mark a vnode as having executable mappings. */ void vn_markexec(struct vnode *vp) { if ((vp->v_iflag & VI_EXECMAP) != 0) { /* Safe unlocked, as long as caller holds a reference. */ return; } rw_enter(vp->v_uobj.vmobjlock, RW_WRITER); mutex_enter(vp->v_interlock); if ((vp->v_iflag & VI_EXECMAP) == 0) { cpu_count(CPU_COUNT_EXECPAGES, vp->v_uobj.uo_npages); vp->v_iflag |= VI_EXECMAP; } mutex_exit(vp->v_interlock); rw_exit(vp->v_uobj.vmobjlock); } /* * Mark a vnode as being the text of a process. * Fail if the vnode is currently writable. */ int vn_marktext(struct vnode *vp) { if ((vp->v_iflag & (VI_TEXT|VI_EXECMAP)) == (VI_TEXT|VI_EXECMAP)) { /* Safe unlocked, as long as caller holds a reference. */ return 0; } rw_enter(vp->v_uobj.vmobjlock, RW_WRITER); mutex_enter(vp->v_interlock); if (vp->v_writecount != 0) { KASSERT((vp->v_iflag & VI_TEXT) == 0); mutex_exit(vp->v_interlock); rw_exit(vp->v_uobj.vmobjlock); return ETXTBSY; } if ((vp->v_iflag & VI_EXECMAP) == 0) { cpu_count(CPU_COUNT_EXECPAGES, vp->v_uobj.uo_npages); } vp->v_iflag |= (VI_TEXT | VI_EXECMAP); mutex_exit(vp->v_interlock); rw_exit(vp->v_uobj.vmobjlock); return 0; } /* * Vnode close call * * Note: takes an unlocked vnode, while VOP_CLOSE takes a locked node. */ int vn_close(struct vnode *vp, int flags, kauth_cred_t cred) { int error; vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); if (flags & FWRITE) { mutex_enter(vp->v_interlock); KASSERT(vp->v_writecount > 0); vp->v_writecount--; mutex_exit(vp->v_interlock); } error = VOP_CLOSE(vp, flags, cred); vput(vp); return error; } static int enforce_rlimit_fsize(struct vnode *vp, struct uio *uio, int ioflag) { struct lwp *l = curlwp; off_t testoff; if (uio->uio_rw != UIO_WRITE || vp->v_type != VREG) return 0; KASSERT(VOP_ISLOCKED(vp) == LK_EXCLUSIVE); if (ioflag & IO_APPEND) testoff = vp->v_size; else testoff = uio->uio_offset; if (testoff + uio->uio_resid > l->l_proc->p_rlimit[RLIMIT_FSIZE].rlim_cur) { mutex_enter(&proc_lock); psignal(l->l_proc, SIGXFSZ); mutex_exit(&proc_lock); return EFBIG; } return 0; } /* * Package up an I/O request on a vnode into a uio and do it. */ int vn_rdwr(enum uio_rw rw, struct vnode *vp, void *base, int len, off_t offset, enum uio_seg segflg, int ioflg, kauth_cred_t cred, size_t *aresid, struct lwp *l) { struct uio auio; struct iovec aiov; int error; if ((ioflg & IO_NODELOCKED) == 0) { if (rw == UIO_READ) { vn_lock(vp, LK_SHARED | LK_RETRY); } else /* UIO_WRITE */ { vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); } } auio.uio_iov = &aiov; auio.uio_iovcnt = 1; aiov.iov_base = base; aiov.iov_len = len; auio.uio_resid = len; auio.uio_offset = offset; auio.uio_rw = rw; if (segflg == UIO_SYSSPACE) { UIO_SETUP_SYSSPACE(&auio); } else { auio.uio_vmspace = l->l_proc->p_vmspace; } if ((error = enforce_rlimit_fsize(vp, &auio, ioflg)) != 0) goto out; if (rw == UIO_READ) { error = VOP_READ(vp, &auio, ioflg, cred); } else { error = VOP_WRITE(vp, &auio, ioflg, cred); } if (aresid) *aresid = auio.uio_resid; else if (auio.uio_resid && error == 0) error = EIO; out: if ((ioflg & IO_NODELOCKED) == 0) { VOP_UNLOCK(vp); } return error; } int vn_readdir(file_t *fp, char *bf, int segflg, u_int count, int *done, struct lwp *l, off_t **cookies, int *ncookies) { struct vnode *vp = fp->f_vnode; struct iovec aiov; struct uio auio; int error, eofflag; /* Limit the size on any kernel buffers used by VOP_READDIR */ count = uimin(MAXBSIZE, count); unionread: if (vp->v_type != VDIR) return EINVAL; aiov.iov_base = bf; aiov.iov_len = count; auio.uio_iov = &aiov; auio.uio_iovcnt = 1; auio.uio_rw = UIO_READ; if (segflg == UIO_SYSSPACE) { UIO_SETUP_SYSSPACE(&auio); } else { KASSERT(l == curlwp); auio.uio_vmspace = l->l_proc->p_vmspace; } auio.uio_resid = count; vn_lock(vp, LK_SHARED | LK_RETRY); mutex_enter(&fp->f_lock); auio.uio_offset = fp->f_offset; mutex_exit(&fp->f_lock); error = VOP_READDIR(vp, &auio, fp->f_cred, &eofflag, cookies, ncookies); mutex_enter(&fp->f_lock); fp->f_offset = auio.uio_offset; mutex_exit(&fp->f_lock); VOP_UNLOCK(vp); if (error) return error; if (count == auio.uio_resid && vn_union_readdir_hook) { struct vnode *ovp = vp; error = (*vn_union_readdir_hook)(&vp, fp, l); if (error) return error; if (vp != ovp) goto unionread; } if (count == auio.uio_resid && (vp->v_vflag & VV_ROOT) && (vp->v_mount->mnt_flag & MNT_UNION)) { struct vnode *tvp = vp; vp = vp->v_mount->mnt_vnodecovered; vref(vp); mutex_enter(&fp->f_lock); fp->f_vnode = vp; fp->f_offset = 0; mutex_exit(&fp->f_lock); vrele(tvp); goto unionread; } *done = count - auio.uio_resid; return error; } /* * File table vnode read routine. */ static int vn_read(file_t *fp, off_t *offset, struct uio *uio, kauth_cred_t cred, int flags) { struct vnode *vp = fp->f_vnode; int error, ioflag, fflag; size_t count; ioflag = IO_ADV_ENCODE(fp->f_advice); fflag = fp->f_flag; if (fflag & FNONBLOCK) ioflag |= IO_NDELAY; if ((fflag & (FFSYNC | FRSYNC)) == (FFSYNC | FRSYNC)) ioflag |= IO_SYNC; if (fflag & FALTIO) ioflag |= IO_ALTSEMANTICS; if (fflag & FDIRECT) ioflag |= IO_DIRECT; if (offset == &fp->f_offset && (flags & FOF_UPDATE_OFFSET) != 0) vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); else vn_lock(vp, LK_SHARED | LK_RETRY); if (__predict_false(vp->v_type == VDIR) && offset == &fp->f_offset && (flags & FOF_UPDATE_OFFSET) == 0) mutex_enter(&fp->f_lock); uio->uio_offset = *offset; if (__predict_false(vp->v_type == VDIR) && offset == &fp->f_offset && (flags & FOF_UPDATE_OFFSET) == 0) mutex_enter(&fp->f_lock); count = uio->uio_resid; error = VOP_READ(vp, uio, ioflag, cred); if (flags & FOF_UPDATE_OFFSET) *offset += count - uio->uio_resid; VOP_UNLOCK(vp); return error; } /* * File table vnode write routine. */ static int vn_write(file_t *fp, off_t *offset, struct uio *uio, kauth_cred_t cred, int flags) { struct vnode *vp = fp->f_vnode; int error, ioflag, fflag; size_t count; ioflag = IO_ADV_ENCODE(fp->f_advice) | IO_UNIT; fflag = fp->f_flag; if (vp->v_type == VREG && (fflag & O_APPEND)) ioflag |= IO_APPEND; if (fflag & FNONBLOCK) ioflag |= IO_NDELAY; if (fflag & FFSYNC || (vp->v_mount && (vp->v_mount->mnt_flag & MNT_SYNCHRONOUS))) ioflag |= IO_SYNC; else if (fflag & FDSYNC) ioflag |= IO_DSYNC; if (fflag & FALTIO) ioflag |= IO_ALTSEMANTICS; if (fflag & FDIRECT) ioflag |= IO_DIRECT; vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); uio->uio_offset = *offset; count = uio->uio_resid; if ((error = enforce_rlimit_fsize(vp, uio, ioflag)) != 0) goto out; error = VOP_WRITE(vp, uio, ioflag, cred); if (flags & FOF_UPDATE_OFFSET) { if (ioflag & IO_APPEND) { /* * SUSv3 describes behaviour for count = 0 as following: * "Before any action ... is taken, and if nbyte is zero * and the file is a regular file, the write() function * ... in the absence of errors ... shall return zero * and have no other results." */ if (count) *offset = uio->uio_offset; } else *offset += count - uio->uio_resid; } out: VOP_UNLOCK(vp); return error; } /* * File table vnode stat routine. */ static int vn_statfile(file_t *fp, struct stat *sb) { struct vnode *vp = fp->f_vnode; int error; vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); error = vn_stat(vp, sb); VOP_UNLOCK(vp); return error; } int vn_stat(struct vnode *vp, struct stat *sb) { struct vattr va; int error; mode_t mode; memset(&va, 0, sizeof(va)); error = VOP_GETATTR(vp, &va, kauth_cred_get()); if (error) return error; /* * Copy from vattr table */ memset(sb, 0, sizeof(*sb)); sb->st_dev = va.va_fsid; sb->st_ino = va.va_fileid; mode = va.va_mode; switch (vp->v_type) { case VREG: mode |= S_IFREG; break; case VDIR: mode |= S_IFDIR; break; case VBLK: mode |= S_IFBLK; break; case VCHR: mode |= S_IFCHR; break; case VLNK: mode |= S_IFLNK; break; case VSOCK: mode |= S_IFSOCK; break; case VFIFO: mode |= S_IFIFO; break; default: return EBADF; } sb->st_mode = mode; sb->st_nlink = va.va_nlink; sb->st_uid = va.va_uid; sb->st_gid = va.va_gid; sb->st_rdev = va.va_rdev; sb->st_size = va.va_size; sb->st_atimespec = va.va_atime; sb->st_mtimespec = va.va_mtime; sb->st_ctimespec = va.va_ctime; sb->st_birthtimespec = va.va_birthtime; sb->st_blksize = va.va_blocksize; sb->st_flags = va.va_flags; sb->st_gen = 0; sb->st_blocks = va.va_bytes / S_BLKSIZE; return 0; } /* * File table vnode fcntl routine. */ static int vn_fcntl(file_t *fp, u_int com, void *data) { struct vnode *vp = fp->f_vnode; int error; error = VOP_FCNTL(vp, com, data, fp->f_flag, kauth_cred_get()); return error; } /* * File table vnode ioctl routine. */ static int vn_ioctl(file_t *fp, u_long com, void *data) { struct vnode *vp = fp->f_vnode, *ovp; struct vattr vattr; int error; switch (vp->v_type) { case VREG: case VDIR: if (com == FIONREAD) { vn_lock(vp, LK_SHARED | LK_RETRY); error = VOP_GETATTR(vp, &vattr, kauth_cred_get()); if (error == 0) { if (vp->v_type == VDIR) mutex_enter(&fp->f_lock); *(int *)data = vattr.va_size - fp->f_offset; if (vp->v_type == VDIR) mutex_exit(&fp->f_lock); } VOP_UNLOCK(vp); if (error) return error; return 0; } if ((com == FIONWRITE) || (com == FIONSPACE)) { /* * Files don't have send queues, so there never * are any bytes in them, nor is there any * open space in them. */ *(int *)data = 0; return 0; } if (com == FIOGETBMAP) { daddr_t *block; if (*(daddr_t *)data < 0) return EINVAL; block = (daddr_t *)data; vn_lock(vp, LK_SHARED | LK_RETRY); error = VOP_BMAP(vp, *block, NULL, block, NULL); VOP_UNLOCK(vp); return error; } if (com == OFIOGETBMAP) { daddr_t ibn, obn; if (*(int32_t *)data < 0) return EINVAL; ibn = (daddr_t)*(int32_t *)data; vn_lock(vp, LK_SHARED | LK_RETRY); error = VOP_BMAP(vp, ibn, NULL, &obn, NULL); VOP_UNLOCK(vp); *(int32_t *)data = (int32_t)obn; return error; } if (com == FIONBIO || com == FIOASYNC) /* XXX */ return 0; /* XXX */ /* FALLTHROUGH */ case VFIFO: case VCHR: case VBLK: error = VOP_IOCTL(vp, com, data, fp->f_flag, kauth_cred_get()); if (error == 0 && com == TIOCSCTTY) { vref(vp); mutex_enter(&proc_lock); ovp = curproc->p_session->s_ttyvp; curproc->p_session->s_ttyvp = vp; mutex_exit(&proc_lock); if (ovp != NULL) vrele(ovp); } return error; default: return EPASSTHROUGH; } } /* * File table vnode poll routine. */ static int vn_poll(file_t *fp, int events) { return VOP_POLL(fp->f_vnode, events); } /* * File table vnode kqfilter routine. */ int vn_kqfilter(file_t *fp, struct knote *kn) { return VOP_KQFILTER(fp->f_vnode, kn); } static int vn_mmap(struct file *fp, off_t *offp, size_t size, int prot, int *flagsp, int *advicep, struct uvm_object **uobjp, int *maxprotp) { struct uvm_object *uobj; struct vnode *vp; struct vattr va; struct lwp *l; vm_prot_t maxprot; off_t off; int error, flags; bool needwritemap; l = curlwp; off = *offp; flags = *flagsp; maxprot = VM_PROT_EXECUTE; KASSERT(size > 0); vp = fp->f_vnode; if (vp->v_type != VREG && vp->v_type != VCHR && vp->v_type != VBLK) { /* only REG/CHR/BLK support mmap */ return ENODEV; } if (vp->v_type != VCHR && off < 0) { return EINVAL; } #if SIZE_MAX > UINT32_MAX /* XXX -Wtype-limits */ if (vp->v_type != VCHR && size > __type_max(off_t)) { return EOVERFLOW; } #endif if (vp->v_type != VCHR && off > __type_max(off_t) - size) { /* no offset wrapping */ return EOVERFLOW; } /* special case: catch SunOS style /dev/zero */ if (vp->v_type == VCHR && (vp->v_rdev == zerodev || COMPAT_ZERODEV(vp->v_rdev))) { *uobjp = NULL; *maxprotp = VM_PROT_ALL; return 0; } /* * Old programs may not select a specific sharing type, so * default to an appropriate one. * * XXX: how does MAP_ANON fit in the picture? */ if ((flags & (MAP_SHARED|MAP_PRIVATE)) == 0) { #if defined(DEBUG) struct proc *p = l->l_proc; printf("WARNING: defaulted mmap() share type to " "%s (pid %d command %s)\n", vp->v_type == VCHR ? "MAP_SHARED" : "MAP_PRIVATE", p->p_pid, p->p_comm); #endif if (vp->v_type == VCHR) flags |= MAP_SHARED; /* for a device */ else flags |= MAP_PRIVATE; /* for a file */ } /* * MAP_PRIVATE device mappings don't make sense (and aren't * supported anyway). However, some programs rely on this, * so just change it to MAP_SHARED. */ if (vp->v_type == VCHR && (flags & MAP_PRIVATE) != 0) { flags = (flags & ~MAP_PRIVATE) | MAP_SHARED; } /* * now check protection */ /* check read access */ if (fp->f_flag & FREAD) maxprot |= VM_PROT_READ; else if (prot & PROT_READ) { return EACCES; } /* check write access, shared case first */ if (flags & MAP_SHARED) { /* * if the file is writable, only add PROT_WRITE to * maxprot if the file is not immutable, append-only. * otherwise, if we have asked for PROT_WRITE, return * EPERM. */ if (fp->f_flag & FWRITE) { vn_lock(vp, LK_SHARED | LK_RETRY); error = VOP_GETATTR(vp, &va, l->l_cred); VOP_UNLOCK(vp); if (error) { return error; } if ((va.va_flags & (SF_SNAPSHOT|IMMUTABLE|APPEND)) == 0) maxprot |= VM_PROT_WRITE; else if (prot & PROT_WRITE) { return EPERM; } } else if (prot & PROT_WRITE) { return EACCES; } } else { /* MAP_PRIVATE mappings can always write to */ maxprot |= VM_PROT_WRITE; } /* * Don't allow mmap for EXEC if the file system * is mounted NOEXEC. */ if ((prot & PROT_EXEC) != 0 && (vp->v_mount->mnt_flag & MNT_NOEXEC) != 0) { return EACCES; } if (vp->v_type != VCHR) { error = VOP_MMAP(vp, prot, curlwp->l_cred); if (error) { return error; } vref(vp); uobj = &vp->v_uobj; /* * If the vnode is being mapped with PROT_EXEC, * then mark it as text. */ if (prot & PROT_EXEC) { vn_markexec(vp); } } else { int i = maxprot; /* * XXX Some devices don't like to be mapped with * XXX PROT_EXEC or PROT_WRITE, but we don't really * XXX have a better way of handling this, right now */ do { uobj = udv_attach(vp->v_rdev, (flags & MAP_SHARED) ? i : (i & ~VM_PROT_WRITE), off, size); i--; } while ((uobj == NULL) && (i > 0)); if (uobj == NULL) { return EINVAL; } *advicep = UVM_ADV_RANDOM; } /* * Set vnode flags to indicate the new kinds of mapping. * We take the vnode lock in exclusive mode here to serialize * with direct I/O. * * Safe to check for these flag values without a lock, as * long as a reference to the vnode is held. */ needwritemap = (vp->v_iflag & VI_WRMAP) == 0 && (flags & MAP_SHARED) != 0 && (maxprot & VM_PROT_WRITE) != 0; if ((vp->v_vflag & VV_MAPPED) == 0 || needwritemap) { vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); vp->v_vflag |= VV_MAPPED; if (needwritemap) { rw_enter(vp->v_uobj.vmobjlock, RW_WRITER); mutex_enter(vp->v_interlock); vp->v_iflag |= VI_WRMAP; mutex_exit(vp->v_interlock); rw_exit(vp->v_uobj.vmobjlock); } VOP_UNLOCK(vp); } #if NVERIEXEC > 0 /* * Check if the file can be executed indirectly. * * XXX: This gives false warnings about "Incorrect access type" * XXX: if the mapping is not executable. Harmless, but will be * XXX: fixed as part of other changes. */ if (veriexec_verify(l, vp, "(mmap)", VERIEXEC_INDIRECT, NULL)) { /* * Don't allow executable mappings if we can't * indirectly execute the file. */ if (prot & VM_PROT_EXECUTE) { return EPERM; } /* * Strip the executable bit from 'maxprot' to make sure * it can't be made executable later. */ maxprot &= ~VM_PROT_EXECUTE; } #endif /* NVERIEXEC > 0 */ *uobjp = uobj; *maxprotp = maxprot; *flagsp = flags; return 0; } static int vn_seek(struct file *fp, off_t delta, int whence, off_t *newoffp, int flags) { const off_t OFF_MIN = __type_min(off_t); const off_t OFF_MAX = __type_max(off_t); kauth_cred_t cred = fp->f_cred; off_t oldoff, newoff; struct vnode *vp = fp->f_vnode; struct vattr vattr; int error; if (vp->v_type == VFIFO) return ESPIPE; if (flags & FOF_UPDATE_OFFSET) vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); else vn_lock(vp, LK_SHARED | LK_RETRY); /* Compute the old and new offsets. */ if (vp->v_type == VDIR && (flags & FOF_UPDATE_OFFSET) == 0) mutex_enter(&fp->f_lock); oldoff = fp->f_offset; if (vp->v_type == VDIR && (flags & FOF_UPDATE_OFFSET) == 0) mutex_exit(&fp->f_lock); switch (whence) { case SEEK_CUR: if (delta > 0) { if (oldoff > 0 && delta > OFF_MAX - oldoff) { newoff = OFF_MAX; break; } } else { if (oldoff < 0 && delta < OFF_MIN - oldoff) { newoff = OFF_MIN; break; } } newoff = oldoff + delta; break; case SEEK_END: error = VOP_GETATTR(vp, &vattr, cred); if (error) goto out; if (vattr.va_size > OFF_MAX || delta > OFF_MAX - (off_t)vattr.va_size) { newoff = OFF_MAX; break; } newoff = delta + vattr.va_size; break; case SEEK_SET: newoff = delta; break; default: error = EINVAL; goto out; } /* Pass the proposed change to the file system to audit. */ error = VOP_SEEK(vp, oldoff, newoff, cred); if (error) goto out; /* Success! */ if (newoffp) *newoffp = newoff; if (flags & FOF_UPDATE_OFFSET) fp->f_offset = newoff; error = 0; out: VOP_UNLOCK(vp); return error; } static int vn_advlock(struct file *fp, void *id, int op, struct flock *fl, int flags) { struct vnode *const vp = fp->f_vnode; if (fl->l_whence == SEEK_CUR) { vn_lock(vp, LK_SHARED | LK_RETRY); fl->l_start += fp->f_offset; VOP_UNLOCK(vp); } return VOP_ADVLOCK(vp, id, op, fl, flags); } static int vn_fpathconf(struct file *fp, int name, register_t *retval) { struct vnode *const vp = fp->f_vnode; int error; vn_lock(vp, LK_SHARED | LK_RETRY); error = VOP_PATHCONF(vp, name, retval); VOP_UNLOCK(vp); return error; } static int vn_posix_fadvise(struct file *fp, off_t offset, off_t len, int advice) { const off_t OFF_MAX = __type_max(off_t); struct vnode *vp = fp->f_vnode; off_t endoffset; int error; if (offset < 0) { return EINVAL; } if (len == 0) { endoffset = OFF_MAX; } else if (len > 0 && (OFF_MAX - offset) >= len) { endoffset = offset + len; } else { return EINVAL; } CTASSERT(POSIX_FADV_NORMAL == UVM_ADV_NORMAL); CTASSERT(POSIX_FADV_RANDOM == UVM_ADV_RANDOM); CTASSERT(POSIX_FADV_SEQUENTIAL == UVM_ADV_SEQUENTIAL); switch (advice) { case POSIX_FADV_WILLNEED: case POSIX_FADV_DONTNEED: if (vp->v_type != VREG && vp->v_type != VBLK) return 0; break; } switch (advice) { case POSIX_FADV_NORMAL: case POSIX_FADV_RANDOM: case POSIX_FADV_SEQUENTIAL: /* * We ignore offset and size. Must lock the file to * do this, as f_advice is sub-word sized. */ mutex_enter(&fp->f_lock); fp->f_advice = (u_char)advice; mutex_exit(&fp->f_lock); error = 0; break; case POSIX_FADV_WILLNEED: error = uvm_readahead(&vp->v_uobj, offset, endoffset - offset); break; case POSIX_FADV_DONTNEED: /* * Align the region to page boundaries as VOP_PUTPAGES expects * by shrinking it. We shrink instead of expand because we * do not want to deactivate cache outside of the requested * region. It means that if the specified region is smaller * than PAGE_SIZE, we do nothing. */ if (offset <= trunc_page(OFF_MAX) && round_page(offset) < trunc_page(endoffset)) { rw_enter(vp->v_uobj.vmobjlock, RW_WRITER); error = VOP_PUTPAGES(vp, round_page(offset), trunc_page(endoffset), PGO_DEACTIVATE | PGO_CLEANIT); } else { error = 0; } break; case POSIX_FADV_NOREUSE: /* Not implemented yet. */ error = 0; break; default: error = EINVAL; break; } return error; } static int vn_truncate(file_t *fp, off_t length) { struct vattr vattr; struct vnode *vp; int error = 0; if (length < 0) return EINVAL; if ((fp->f_flag & FWRITE) == 0) return EINVAL; vp = fp->f_vnode; vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); if (vp->v_type == VDIR) error = EISDIR; else if ((error = vn_writechk(vp)) == 0) { vattr_null(&vattr); vattr.va_size = length; error = VOP_SETATTR(vp, &vattr, fp->f_cred); } VOP_UNLOCK(vp); return error; } /* * Check that the vnode is still valid, and if so * acquire requested lock. */ int vn_lock(struct vnode *vp, int flags) { struct lwp *l; int error; KASSERT(vrefcnt(vp) > 0); KASSERT((flags & ~(LK_SHARED|LK_EXCLUSIVE|LK_NOWAIT|LK_RETRY| LK_UPGRADE|LK_DOWNGRADE)) == 0); KASSERT((flags & LK_NOWAIT) != 0 || !mutex_owned(vp->v_interlock)); #ifdef DIAGNOSTIC if (wapbl_vphaswapbl(vp)) WAPBL_JUNLOCK_ASSERT(wapbl_vptomp(vp)); #endif /* Get a more useful report for lockstat. */ l = curlwp; KASSERT(l->l_rwcallsite == 0); l->l_rwcallsite = (uintptr_t)__builtin_return_address(0); error = VOP_LOCK(vp, flags); l->l_rwcallsite = 0; switch (flags & (LK_RETRY | LK_NOWAIT)) { case 0: KASSERT(error == 0 || error == ENOENT); break; case LK_RETRY: KASSERT(error == 0); break; case LK_NOWAIT: KASSERT(error == 0 || error == EBUSY || error == ENOENT); break; case LK_RETRY | LK_NOWAIT: KASSERT(error == 0 || error == EBUSY); break; } return error; } /* * File table vnode close routine. */ static int vn_closefile(file_t *fp) { return vn_close(fp->f_vnode, fp->f_flag, fp->f_cred); } /* * Simplified in-kernel wrapper calls for extended attribute access. * Both calls pass in a NULL credential, authorizing a "kernel" access. * Set IO_NODELOCKED in ioflg if the vnode is already locked. */ int vn_extattr_get(struct vnode *vp, int ioflg, int attrnamespace, const char *attrname, size_t *buflen, void *bf, struct lwp *l) { struct uio auio; struct iovec aiov; int error; aiov.iov_len = *buflen; aiov.iov_base = bf; auio.uio_iov = &aiov; auio.uio_iovcnt = 1; auio.uio_rw = UIO_READ; auio.uio_offset = 0; auio.uio_resid = *buflen; UIO_SETUP_SYSSPACE(&auio); if ((ioflg & IO_NODELOCKED) == 0) vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); error = VOP_GETEXTATTR(vp, attrnamespace, attrname, &auio, NULL, NOCRED); if ((ioflg & IO_NODELOCKED) == 0) VOP_UNLOCK(vp); if (error == 0) *buflen = *buflen - auio.uio_resid; return error; } /* * XXX Failure mode if partially written? */ int vn_extattr_set(struct vnode *vp, int ioflg, int attrnamespace, const char *attrname, size_t buflen, const void *bf, struct lwp *l) { struct uio auio; struct iovec aiov; int error; aiov.iov_len = buflen; aiov.iov_base = __UNCONST(bf); /* XXXUNCONST kills const */ auio.uio_iov = &aiov; auio.uio_iovcnt = 1; auio.uio_rw = UIO_WRITE; auio.uio_offset = 0; auio.uio_resid = buflen; UIO_SETUP_SYSSPACE(&auio); if ((ioflg & IO_NODELOCKED) == 0) { vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); } error = VOP_SETEXTATTR(vp, attrnamespace, attrname, &auio, NOCRED); if ((ioflg & IO_NODELOCKED) == 0) { VOP_UNLOCK(vp); } return error; } int vn_extattr_rm(struct vnode *vp, int ioflg, int attrnamespace, const char *attrname, struct lwp *l) { int error; if ((ioflg & IO_NODELOCKED) == 0) { vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); } error = VOP_DELETEEXTATTR(vp, attrnamespace, attrname, NOCRED); if (error == EOPNOTSUPP) error = VOP_SETEXTATTR(vp, attrnamespace, attrname, NULL, NOCRED); if ((ioflg & IO_NODELOCKED) == 0) { VOP_UNLOCK(vp); } return error; } int vn_fifo_bypass(void *v) { struct vop_generic_args *ap = v; return VOCALL(fifo_vnodeop_p, ap->a_desc->vdesc_offset, v); } /* * Open block device by device number */ int vn_bdev_open(dev_t dev, struct vnode **vpp, struct lwp *l) { int error; if ((error = bdevvp(dev, vpp)) != 0) return error; vn_lock(*vpp, LK_EXCLUSIVE | LK_RETRY); if ((error = VOP_OPEN(*vpp, FREAD | FWRITE, l->l_cred)) != 0) { vput(*vpp); return error; } mutex_enter((*vpp)->v_interlock); (*vpp)->v_writecount++; mutex_exit((*vpp)->v_interlock); VOP_UNLOCK(*vpp); return 0; } /* * Lookup the provided name in the filesystem. If the file exists, * is a valid block device, and isn't being used by anyone else, * set *vpp to the file's vnode. */ int vn_bdev_openpath(struct pathbuf *pb, struct vnode **vpp, struct lwp *l) { struct vnode *vp; dev_t dev; enum vtype vt; int error; error = vn_open(NULL, pb, 0, FREAD | FWRITE, 0, &vp, NULL, NULL); if (error != 0) return error; dev = vp->v_rdev; vt = vp->v_type; VOP_UNLOCK(vp); (void) vn_close(vp, FREAD | FWRITE, l->l_cred); if (vt != VBLK) return ENOTBLK; return vn_bdev_open(dev, vpp, l); } static long vn_knote_to_interest(const struct knote *kn) { switch (kn->kn_filter) { case EVFILT_READ: /* * Writing to the file or changing its attributes can * set the file size, which impacts the readability * filter. * * (No need to set NOTE_EXTEND here; it's only ever * send with other hints; see vnode_if.c.) */ return NOTE_WRITE | NOTE_ATTRIB; case EVFILT_VNODE: return kn->kn_sfflags; case EVFILT_WRITE: default: return 0; } } void vn_knote_attach(struct vnode *vp, struct knote *kn) { struct vnode_klist *vk = vp->v_klist; long interest = 0; /* * In the case of layered / stacked file systems, knotes * should only ever be associated with the base vnode. */ KASSERT(kn->kn_hook == vp); KASSERT(vp->v_klist == &VNODE_TO_VIMPL(vp)->vi_klist); /* * We maintain a bitmask of the kevents that there is interest in, * to minimize the impact of having watchers. It's silly to have * to traverse vn_klist every time a read or write happens simply * because there is someone interested in knowing when the file * is deleted, for example. */ mutex_enter(vp->v_interlock); SLIST_INSERT_HEAD(&vk->vk_klist, kn, kn_selnext); SLIST_FOREACH(kn, &vk->vk_klist, kn_selnext) { interest |= vn_knote_to_interest(kn); } vk->vk_interest = interest; mutex_exit(vp->v_interlock); } void vn_knote_detach(struct vnode *vp, struct knote *kn) { struct vnode_klist *vk = vp->v_klist; long interest = 0; /* See above. */ KASSERT(kn->kn_hook == vp); KASSERT(vp->v_klist == &VNODE_TO_VIMPL(vp)->vi_klist); /* * We special case removing the head of the list, because: * * 1. It's extremely likely that we're detaching the only * knote. * * 2. We're already traversing the whole list, so we don't * want to use the generic SLIST_REMOVE() which would * traverse it *again*. */ mutex_enter(vp->v_interlock); if (__predict_true(kn == SLIST_FIRST(&vk->vk_klist))) { SLIST_REMOVE_HEAD(&vk->vk_klist, kn_selnext); SLIST_FOREACH(kn, &vk->vk_klist, kn_selnext) { interest |= vn_knote_to_interest(kn); } vk->vk_interest = interest; } else { struct knote *thiskn, *nextkn, *prevkn = NULL; SLIST_FOREACH_SAFE(thiskn, &vk->vk_klist, kn_selnext, nextkn) { if (thiskn == kn) { KASSERT(kn != NULL); KASSERT(prevkn != NULL); SLIST_REMOVE_AFTER(prevkn, kn_selnext); kn = NULL; } else { interest |= vn_knote_to_interest(thiskn); prevkn = thiskn; } } vk->vk_interest = interest; } mutex_exit(vp->v_interlock); }