Index: head/sys/kern/kern_descrip.c =================================================================== --- head/sys/kern/kern_descrip.c (revision 342057) +++ head/sys/kern/kern_descrip.c (revision 342058) @@ -1,4246 +1,4235 @@ /*- * SPDX-License-Identifier: BSD-3-Clause * * Copyright (c) 1982, 1986, 1989, 1991, 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. * * @(#)kern_descrip.c 8.6 (Berkeley) 4/19/94 */ #include __FBSDID("$FreeBSD$"); #include "opt_capsicum.h" #include "opt_ddb.h" #include "opt_ktrace.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 #include #include #include #include #include #include #include #include #ifdef KTRACE #include #endif #include #include #include #include #include static MALLOC_DEFINE(M_FILEDESC, "filedesc", "Open file descriptor table"); static MALLOC_DEFINE(M_FILEDESC_TO_LEADER, "filedesc_to_leader", "file desc to leader structures"); static MALLOC_DEFINE(M_SIGIO, "sigio", "sigio structures"); MALLOC_DEFINE(M_FILECAPS, "filecaps", "descriptor capabilities"); MALLOC_DECLARE(M_FADVISE); static __read_mostly uma_zone_t file_zone; static __read_mostly uma_zone_t filedesc0_zone; static int closefp(struct filedesc *fdp, int fd, struct file *fp, struct thread *td, int holdleaders); static int fd_first_free(struct filedesc *fdp, int low, int size); static int fd_last_used(struct filedesc *fdp, int size); static void fdgrowtable(struct filedesc *fdp, int nfd); static void fdgrowtable_exp(struct filedesc *fdp, int nfd); static void fdunused(struct filedesc *fdp, int fd); static void fdused(struct filedesc *fdp, int fd); static int getmaxfd(struct thread *td); static u_long *filecaps_copy_prep(const struct filecaps *src); static void filecaps_copy_finish(const struct filecaps *src, struct filecaps *dst, u_long *ioctls); static u_long *filecaps_free_prep(struct filecaps *fcaps); static void filecaps_free_finish(u_long *ioctls); /* * Each process has: * * - An array of open file descriptors (fd_ofiles) * - An array of file flags (fd_ofileflags) * - A bitmap recording which descriptors are in use (fd_map) * * A process starts out with NDFILE descriptors. The value of NDFILE has * been selected based the historical limit of 20 open files, and an * assumption that the majority of processes, especially short-lived * processes like shells, will never need more. * * If this initial allocation is exhausted, a larger descriptor table and * map are allocated dynamically, and the pointers in the process's struct * filedesc are updated to point to those. This is repeated every time * the process runs out of file descriptors (provided it hasn't hit its * resource limit). * * Since threads may hold references to individual descriptor table * entries, the tables are never freed. Instead, they are placed on a * linked list and freed only when the struct filedesc is released. */ #define NDFILE 20 #define NDSLOTSIZE sizeof(NDSLOTTYPE) #define NDENTRIES (NDSLOTSIZE * __CHAR_BIT) #define NDSLOT(x) ((x) / NDENTRIES) #define NDBIT(x) ((NDSLOTTYPE)1 << ((x) % NDENTRIES)) #define NDSLOTS(x) (((x) + NDENTRIES - 1) / NDENTRIES) /* * SLIST entry used to keep track of ofiles which must be reclaimed when * the process exits. */ struct freetable { struct fdescenttbl *ft_table; SLIST_ENTRY(freetable) ft_next; }; /* * Initial allocation: a filedesc structure + the head of SLIST used to * keep track of old ofiles + enough space for NDFILE descriptors. */ struct fdescenttbl0 { int fdt_nfiles; struct filedescent fdt_ofiles[NDFILE]; }; struct filedesc0 { struct filedesc fd_fd; SLIST_HEAD(, freetable) fd_free; struct fdescenttbl0 fd_dfiles; NDSLOTTYPE fd_dmap[NDSLOTS(NDFILE)]; }; /* * Descriptor management. */ volatile int __exclusive_cache_line openfiles; /* actual number of open files */ struct mtx sigio_lock; /* mtx to protect pointers to sigio */ void __read_mostly (*mq_fdclose)(struct thread *td, int fd, struct file *fp); /* * If low >= size, just return low. Otherwise find the first zero bit in the * given bitmap, starting at low and not exceeding size - 1. Return size if * not found. */ static int fd_first_free(struct filedesc *fdp, int low, int size) { NDSLOTTYPE *map = fdp->fd_map; NDSLOTTYPE mask; int off, maxoff; if (low >= size) return (low); off = NDSLOT(low); if (low % NDENTRIES) { mask = ~(~(NDSLOTTYPE)0 >> (NDENTRIES - (low % NDENTRIES))); if ((mask &= ~map[off]) != 0UL) return (off * NDENTRIES + ffsl(mask) - 1); ++off; } for (maxoff = NDSLOTS(size); off < maxoff; ++off) if (map[off] != ~0UL) return (off * NDENTRIES + ffsl(~map[off]) - 1); return (size); } /* * Find the highest non-zero bit in the given bitmap, starting at 0 and * not exceeding size - 1. Return -1 if not found. */ static int fd_last_used(struct filedesc *fdp, int size) { NDSLOTTYPE *map = fdp->fd_map; NDSLOTTYPE mask; int off, minoff; off = NDSLOT(size); if (size % NDENTRIES) { mask = ~(~(NDSLOTTYPE)0 << (size % NDENTRIES)); if ((mask &= map[off]) != 0) return (off * NDENTRIES + flsl(mask) - 1); --off; } for (minoff = NDSLOT(0); off >= minoff; --off) if (map[off] != 0) return (off * NDENTRIES + flsl(map[off]) - 1); return (-1); } static int fdisused(struct filedesc *fdp, int fd) { KASSERT(fd >= 0 && fd < fdp->fd_nfiles, ("file descriptor %d out of range (0, %d)", fd, fdp->fd_nfiles)); return ((fdp->fd_map[NDSLOT(fd)] & NDBIT(fd)) != 0); } /* * Mark a file descriptor as used. */ static void fdused_init(struct filedesc *fdp, int fd) { KASSERT(!fdisused(fdp, fd), ("fd=%d is already used", fd)); fdp->fd_map[NDSLOT(fd)] |= NDBIT(fd); } static void fdused(struct filedesc *fdp, int fd) { FILEDESC_XLOCK_ASSERT(fdp); fdused_init(fdp, fd); if (fd > fdp->fd_lastfile) fdp->fd_lastfile = fd; if (fd == fdp->fd_freefile) fdp->fd_freefile++; } /* * Mark a file descriptor as unused. */ static void fdunused(struct filedesc *fdp, int fd) { FILEDESC_XLOCK_ASSERT(fdp); KASSERT(fdisused(fdp, fd), ("fd=%d is already unused", fd)); KASSERT(fdp->fd_ofiles[fd].fde_file == NULL, ("fd=%d is still in use", fd)); fdp->fd_map[NDSLOT(fd)] &= ~NDBIT(fd); if (fd < fdp->fd_freefile) fdp->fd_freefile = fd; if (fd == fdp->fd_lastfile) fdp->fd_lastfile = fd_last_used(fdp, fd); } /* * Free a file descriptor. * * Avoid some work if fdp is about to be destroyed. */ static inline void fdefree_last(struct filedescent *fde) { filecaps_free(&fde->fde_caps); } static inline void fdfree(struct filedesc *fdp, int fd) { struct filedescent *fde; fde = &fdp->fd_ofiles[fd]; #ifdef CAPABILITIES seq_write_begin(&fde->fde_seq); #endif fde->fde_file = NULL; #ifdef CAPABILITIES seq_write_end(&fde->fde_seq); #endif fdefree_last(fde); fdunused(fdp, fd); } void pwd_ensure_dirs(void) { struct filedesc *fdp; fdp = curproc->p_fd; FILEDESC_XLOCK(fdp); if (fdp->fd_cdir == NULL) { fdp->fd_cdir = rootvnode; vrefact(rootvnode); } if (fdp->fd_rdir == NULL) { fdp->fd_rdir = rootvnode; vrefact(rootvnode); } FILEDESC_XUNLOCK(fdp); } /* * System calls on descriptors. */ #ifndef _SYS_SYSPROTO_H_ struct getdtablesize_args { int dummy; }; #endif /* ARGSUSED */ int sys_getdtablesize(struct thread *td, struct getdtablesize_args *uap) { #ifdef RACCT uint64_t lim; #endif td->td_retval[0] = getmaxfd(td); #ifdef RACCT PROC_LOCK(td->td_proc); lim = racct_get_limit(td->td_proc, RACCT_NOFILE); PROC_UNLOCK(td->td_proc); if (lim < td->td_retval[0]) td->td_retval[0] = lim; #endif return (0); } /* * Duplicate a file descriptor to a particular value. * * Note: keep in mind that a potential race condition exists when closing * descriptors from a shared descriptor table (via rfork). */ #ifndef _SYS_SYSPROTO_H_ struct dup2_args { u_int from; u_int to; }; #endif /* ARGSUSED */ int sys_dup2(struct thread *td, struct dup2_args *uap) { return (kern_dup(td, FDDUP_FIXED, 0, (int)uap->from, (int)uap->to)); } /* * Duplicate a file descriptor. */ #ifndef _SYS_SYSPROTO_H_ struct dup_args { u_int fd; }; #endif /* ARGSUSED */ int sys_dup(struct thread *td, struct dup_args *uap) { return (kern_dup(td, FDDUP_NORMAL, 0, (int)uap->fd, 0)); } /* * The file control system call. */ #ifndef _SYS_SYSPROTO_H_ struct fcntl_args { int fd; int cmd; long arg; }; #endif /* ARGSUSED */ int sys_fcntl(struct thread *td, struct fcntl_args *uap) { return (kern_fcntl_freebsd(td, uap->fd, uap->cmd, uap->arg)); } int kern_fcntl_freebsd(struct thread *td, int fd, int cmd, long arg) { struct flock fl; struct __oflock ofl; intptr_t arg1; int error, newcmd; error = 0; newcmd = cmd; switch (cmd) { case F_OGETLK: case F_OSETLK: case F_OSETLKW: /* * Convert old flock structure to new. */ error = copyin((void *)(intptr_t)arg, &ofl, sizeof(ofl)); fl.l_start = ofl.l_start; fl.l_len = ofl.l_len; fl.l_pid = ofl.l_pid; fl.l_type = ofl.l_type; fl.l_whence = ofl.l_whence; fl.l_sysid = 0; switch (cmd) { case F_OGETLK: newcmd = F_GETLK; break; case F_OSETLK: newcmd = F_SETLK; break; case F_OSETLKW: newcmd = F_SETLKW; break; } arg1 = (intptr_t)&fl; break; case F_GETLK: case F_SETLK: case F_SETLKW: case F_SETLK_REMOTE: error = copyin((void *)(intptr_t)arg, &fl, sizeof(fl)); arg1 = (intptr_t)&fl; break; default: arg1 = arg; break; } if (error) return (error); error = kern_fcntl(td, fd, newcmd, arg1); if (error) return (error); if (cmd == F_OGETLK) { ofl.l_start = fl.l_start; ofl.l_len = fl.l_len; ofl.l_pid = fl.l_pid; ofl.l_type = fl.l_type; ofl.l_whence = fl.l_whence; error = copyout(&ofl, (void *)(intptr_t)arg, sizeof(ofl)); } else if (cmd == F_GETLK) { error = copyout(&fl, (void *)(intptr_t)arg, sizeof(fl)); } return (error); } int kern_fcntl(struct thread *td, int fd, int cmd, intptr_t arg) { struct filedesc *fdp; struct flock *flp; struct file *fp, *fp2; struct filedescent *fde; struct proc *p; struct vnode *vp; int error, flg, tmp; uint64_t bsize; off_t foffset; error = 0; flg = F_POSIX; p = td->td_proc; fdp = p->p_fd; AUDIT_ARG_FD(cmd); AUDIT_ARG_CMD(cmd); switch (cmd) { case F_DUPFD: tmp = arg; error = kern_dup(td, FDDUP_FCNTL, 0, fd, tmp); break; case F_DUPFD_CLOEXEC: tmp = arg; error = kern_dup(td, FDDUP_FCNTL, FDDUP_FLAG_CLOEXEC, fd, tmp); break; case F_DUP2FD: tmp = arg; error = kern_dup(td, FDDUP_FIXED, 0, fd, tmp); break; case F_DUP2FD_CLOEXEC: tmp = arg; error = kern_dup(td, FDDUP_FIXED, FDDUP_FLAG_CLOEXEC, fd, tmp); break; case F_GETFD: error = EBADF; FILEDESC_SLOCK(fdp); fde = fdeget_locked(fdp, fd); if (fde != NULL) { td->td_retval[0] = (fde->fde_flags & UF_EXCLOSE) ? FD_CLOEXEC : 0; error = 0; } FILEDESC_SUNLOCK(fdp); break; case F_SETFD: error = EBADF; FILEDESC_XLOCK(fdp); fde = fdeget_locked(fdp, fd); if (fde != NULL) { fde->fde_flags = (fde->fde_flags & ~UF_EXCLOSE) | (arg & FD_CLOEXEC ? UF_EXCLOSE : 0); error = 0; } FILEDESC_XUNLOCK(fdp); break; case F_GETFL: error = fget_fcntl(td, fd, &cap_fcntl_rights, F_GETFL, &fp); if (error != 0) break; td->td_retval[0] = OFLAGS(fp->f_flag); fdrop(fp, td); break; case F_SETFL: error = fget_fcntl(td, fd, &cap_fcntl_rights, F_SETFL, &fp); if (error != 0) break; do { tmp = flg = fp->f_flag; tmp &= ~FCNTLFLAGS; tmp |= FFLAGS(arg & ~O_ACCMODE) & FCNTLFLAGS; } while(atomic_cmpset_int(&fp->f_flag, flg, tmp) == 0); tmp = fp->f_flag & FNONBLOCK; error = fo_ioctl(fp, FIONBIO, &tmp, td->td_ucred, td); if (error != 0) { fdrop(fp, td); break; } tmp = fp->f_flag & FASYNC; error = fo_ioctl(fp, FIOASYNC, &tmp, td->td_ucred, td); if (error == 0) { fdrop(fp, td); break; } atomic_clear_int(&fp->f_flag, FNONBLOCK); tmp = 0; (void)fo_ioctl(fp, FIONBIO, &tmp, td->td_ucred, td); fdrop(fp, td); break; case F_GETOWN: error = fget_fcntl(td, fd, &cap_fcntl_rights, F_GETOWN, &fp); if (error != 0) break; error = fo_ioctl(fp, FIOGETOWN, &tmp, td->td_ucred, td); if (error == 0) td->td_retval[0] = tmp; fdrop(fp, td); break; case F_SETOWN: error = fget_fcntl(td, fd, &cap_fcntl_rights, F_SETOWN, &fp); if (error != 0) break; tmp = arg; error = fo_ioctl(fp, FIOSETOWN, &tmp, td->td_ucred, td); fdrop(fp, td); break; case F_SETLK_REMOTE: error = priv_check(td, PRIV_NFS_LOCKD); if (error) return (error); flg = F_REMOTE; goto do_setlk; case F_SETLKW: flg |= F_WAIT; /* FALLTHROUGH F_SETLK */ case F_SETLK: do_setlk: error = fget_unlocked(fdp, fd, &cap_flock_rights, &fp, NULL); if (error != 0) break; if (fp->f_type != DTYPE_VNODE) { error = EBADF; fdrop(fp, td); break; } flp = (struct flock *)arg; if (flp->l_whence == SEEK_CUR) { foffset = foffset_get(fp); if (foffset < 0 || (flp->l_start > 0 && foffset > OFF_MAX - flp->l_start)) { error = EOVERFLOW; fdrop(fp, td); break; } flp->l_start += foffset; } vp = fp->f_vnode; switch (flp->l_type) { case F_RDLCK: if ((fp->f_flag & FREAD) == 0) { error = EBADF; break; } if ((p->p_leader->p_flag & P_ADVLOCK) == 0) { PROC_LOCK(p->p_leader); p->p_leader->p_flag |= P_ADVLOCK; PROC_UNLOCK(p->p_leader); } error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_SETLK, flp, flg); break; case F_WRLCK: if ((fp->f_flag & FWRITE) == 0) { error = EBADF; break; } if ((p->p_leader->p_flag & P_ADVLOCK) == 0) { PROC_LOCK(p->p_leader); p->p_leader->p_flag |= P_ADVLOCK; PROC_UNLOCK(p->p_leader); } error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_SETLK, flp, flg); break; case F_UNLCK: error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_UNLCK, flp, flg); break; case F_UNLCKSYS: /* * Temporary api for testing remote lock * infrastructure. */ if (flg != F_REMOTE) { error = EINVAL; break; } error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_UNLCKSYS, flp, flg); break; default: error = EINVAL; break; } if (error != 0 || flp->l_type == F_UNLCK || flp->l_type == F_UNLCKSYS) { fdrop(fp, td); break; } /* * Check for a race with close. * * The vnode is now advisory locked (or unlocked, but this case * is not really important) as the caller requested. * We had to drop the filedesc lock, so we need to recheck if * the descriptor is still valid, because if it was closed * in the meantime we need to remove advisory lock from the * vnode - close on any descriptor leading to an advisory * locked vnode, removes that lock. * We will return 0 on purpose in that case, as the result of * successful advisory lock might have been externally visible * already. This is fine - effectively we pretend to the caller * that the closing thread was a bit slower and that the * advisory lock succeeded before the close. */ error = fget_unlocked(fdp, fd, &cap_no_rights, &fp2, NULL); if (error != 0) { fdrop(fp, td); break; } if (fp != fp2) { flp->l_whence = SEEK_SET; flp->l_start = 0; flp->l_len = 0; flp->l_type = F_UNLCK; (void) VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_UNLCK, flp, F_POSIX); } fdrop(fp, td); fdrop(fp2, td); break; case F_GETLK: error = fget_unlocked(fdp, fd, &cap_flock_rights, &fp, NULL); if (error != 0) break; if (fp->f_type != DTYPE_VNODE) { error = EBADF; fdrop(fp, td); break; } flp = (struct flock *)arg; if (flp->l_type != F_RDLCK && flp->l_type != F_WRLCK && flp->l_type != F_UNLCK) { error = EINVAL; fdrop(fp, td); break; } if (flp->l_whence == SEEK_CUR) { foffset = foffset_get(fp); if ((flp->l_start > 0 && foffset > OFF_MAX - flp->l_start) || (flp->l_start < 0 && foffset < OFF_MIN - flp->l_start)) { error = EOVERFLOW; fdrop(fp, td); break; } flp->l_start += foffset; } vp = fp->f_vnode; error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_GETLK, flp, F_POSIX); fdrop(fp, td); break; case F_RDAHEAD: arg = arg ? 128 * 1024: 0; /* FALLTHROUGH */ case F_READAHEAD: error = fget_unlocked(fdp, fd, &cap_no_rights, &fp, NULL); if (error != 0) break; if (fp->f_type != DTYPE_VNODE) { fdrop(fp, td); error = EBADF; break; } vp = fp->f_vnode; /* * Exclusive lock synchronizes against f_seqcount reads and * writes in sequential_heuristic(). */ error = vn_lock(vp, LK_EXCLUSIVE); if (error != 0) { fdrop(fp, td); break; } if (arg >= 0) { bsize = fp->f_vnode->v_mount->mnt_stat.f_iosize; fp->f_seqcount = (arg + bsize - 1) / bsize; atomic_set_int(&fp->f_flag, FRDAHEAD); } else { atomic_clear_int(&fp->f_flag, FRDAHEAD); } VOP_UNLOCK(vp, 0); fdrop(fp, td); break; default: error = EINVAL; break; } return (error); } static int getmaxfd(struct thread *td) { return (min((int)lim_cur(td, RLIMIT_NOFILE), maxfilesperproc)); } /* * Common code for dup, dup2, fcntl(F_DUPFD) and fcntl(F_DUP2FD). */ int kern_dup(struct thread *td, u_int mode, int flags, int old, int new) { struct filedesc *fdp; struct filedescent *oldfde, *newfde; struct proc *p; struct file *delfp; u_long *oioctls, *nioctls; int error, maxfd; p = td->td_proc; fdp = p->p_fd; oioctls = NULL; MPASS((flags & ~(FDDUP_FLAG_CLOEXEC)) == 0); MPASS(mode < FDDUP_LASTMODE); AUDIT_ARG_FD(old); /* XXXRW: if (flags & FDDUP_FIXED) AUDIT_ARG_FD2(new); */ /* * Verify we have a valid descriptor to dup from and possibly to * dup to. Unlike dup() and dup2(), fcntl()'s F_DUPFD should * return EINVAL when the new descriptor is out of bounds. */ if (old < 0) return (EBADF); if (new < 0) return (mode == FDDUP_FCNTL ? EINVAL : EBADF); maxfd = getmaxfd(td); if (new >= maxfd) return (mode == FDDUP_FCNTL ? EINVAL : EBADF); error = EBADF; FILEDESC_XLOCK(fdp); if (fget_locked(fdp, old) == NULL) goto unlock; if ((mode == FDDUP_FIXED || mode == FDDUP_MUSTREPLACE) && old == new) { td->td_retval[0] = new; if (flags & FDDUP_FLAG_CLOEXEC) fdp->fd_ofiles[new].fde_flags |= UF_EXCLOSE; error = 0; goto unlock; } /* * If the caller specified a file descriptor, make sure the file * table is large enough to hold it, and grab it. Otherwise, just * allocate a new descriptor the usual way. */ switch (mode) { case FDDUP_NORMAL: case FDDUP_FCNTL: if ((error = fdalloc(td, new, &new)) != 0) goto unlock; break; case FDDUP_MUSTREPLACE: /* Target file descriptor must exist. */ if (fget_locked(fdp, new) == NULL) goto unlock; break; case FDDUP_FIXED: if (new >= fdp->fd_nfiles) { /* * The resource limits are here instead of e.g. * fdalloc(), because the file descriptor table may be * shared between processes, so we can't really use * racct_add()/racct_sub(). Instead of counting the * number of actually allocated descriptors, just put * the limit on the size of the file descriptor table. */ #ifdef RACCT if (RACCT_ENABLED()) { error = racct_set_unlocked(p, RACCT_NOFILE, new + 1); if (error != 0) { error = EMFILE; goto unlock; } } #endif fdgrowtable_exp(fdp, new + 1); } if (!fdisused(fdp, new)) fdused(fdp, new); break; default: KASSERT(0, ("%s unsupported mode %d", __func__, mode)); } KASSERT(old != new, ("new fd is same as old")); oldfde = &fdp->fd_ofiles[old]; fhold(oldfde->fde_file); newfde = &fdp->fd_ofiles[new]; delfp = newfde->fde_file; oioctls = filecaps_free_prep(&newfde->fde_caps); nioctls = filecaps_copy_prep(&oldfde->fde_caps); /* * Duplicate the source descriptor. */ #ifdef CAPABILITIES seq_write_begin(&newfde->fde_seq); #endif memcpy(newfde, oldfde, fde_change_size); filecaps_copy_finish(&oldfde->fde_caps, &newfde->fde_caps, nioctls); if ((flags & FDDUP_FLAG_CLOEXEC) != 0) newfde->fde_flags = oldfde->fde_flags | UF_EXCLOSE; else newfde->fde_flags = oldfde->fde_flags & ~UF_EXCLOSE; #ifdef CAPABILITIES seq_write_end(&newfde->fde_seq); #endif td->td_retval[0] = new; error = 0; if (delfp != NULL) { (void) closefp(fdp, new, delfp, td, 1); FILEDESC_UNLOCK_ASSERT(fdp); } else { unlock: FILEDESC_XUNLOCK(fdp); } filecaps_free_finish(oioctls); return (error); } /* * If sigio is on the list associated with a process or process group, * disable signalling from the device, remove sigio from the list and * free sigio. */ void funsetown(struct sigio **sigiop) { struct sigio *sigio; if (*sigiop == NULL) return; SIGIO_LOCK(); sigio = *sigiop; if (sigio == NULL) { SIGIO_UNLOCK(); return; } *(sigio->sio_myref) = NULL; if ((sigio)->sio_pgid < 0) { struct pgrp *pg = (sigio)->sio_pgrp; PGRP_LOCK(pg); SLIST_REMOVE(&sigio->sio_pgrp->pg_sigiolst, sigio, sigio, sio_pgsigio); PGRP_UNLOCK(pg); } else { struct proc *p = (sigio)->sio_proc; PROC_LOCK(p); SLIST_REMOVE(&sigio->sio_proc->p_sigiolst, sigio, sigio, sio_pgsigio); PROC_UNLOCK(p); } SIGIO_UNLOCK(); crfree(sigio->sio_ucred); free(sigio, M_SIGIO); } /* * Free a list of sigio structures. * We only need to lock the SIGIO_LOCK because we have made ourselves * inaccessible to callers of fsetown and therefore do not need to lock * the proc or pgrp struct for the list manipulation. */ void funsetownlst(struct sigiolst *sigiolst) { struct proc *p; struct pgrp *pg; struct sigio *sigio; sigio = SLIST_FIRST(sigiolst); if (sigio == NULL) return; p = NULL; pg = NULL; /* * Every entry of the list should belong * to a single proc or pgrp. */ if (sigio->sio_pgid < 0) { pg = sigio->sio_pgrp; PGRP_LOCK_ASSERT(pg, MA_NOTOWNED); } else /* if (sigio->sio_pgid > 0) */ { p = sigio->sio_proc; PROC_LOCK_ASSERT(p, MA_NOTOWNED); } SIGIO_LOCK(); while ((sigio = SLIST_FIRST(sigiolst)) != NULL) { *(sigio->sio_myref) = NULL; if (pg != NULL) { KASSERT(sigio->sio_pgid < 0, ("Proc sigio in pgrp sigio list")); KASSERT(sigio->sio_pgrp == pg, ("Bogus pgrp in sigio list")); PGRP_LOCK(pg); SLIST_REMOVE(&pg->pg_sigiolst, sigio, sigio, sio_pgsigio); PGRP_UNLOCK(pg); } else /* if (p != NULL) */ { KASSERT(sigio->sio_pgid > 0, ("Pgrp sigio in proc sigio list")); KASSERT(sigio->sio_proc == p, ("Bogus proc in sigio list")); PROC_LOCK(p); SLIST_REMOVE(&p->p_sigiolst, sigio, sigio, sio_pgsigio); PROC_UNLOCK(p); } SIGIO_UNLOCK(); crfree(sigio->sio_ucred); free(sigio, M_SIGIO); SIGIO_LOCK(); } SIGIO_UNLOCK(); } /* * This is common code for FIOSETOWN ioctl called by fcntl(fd, F_SETOWN, arg). * * After permission checking, add a sigio structure to the sigio list for * the process or process group. */ int fsetown(pid_t pgid, struct sigio **sigiop) { struct proc *proc; struct pgrp *pgrp; struct sigio *sigio; int ret; if (pgid == 0) { funsetown(sigiop); return (0); } ret = 0; /* Allocate and fill in the new sigio out of locks. */ sigio = malloc(sizeof(struct sigio), M_SIGIO, M_WAITOK); sigio->sio_pgid = pgid; sigio->sio_ucred = crhold(curthread->td_ucred); sigio->sio_myref = sigiop; sx_slock(&proctree_lock); if (pgid > 0) { proc = pfind(pgid); if (proc == NULL) { ret = ESRCH; goto fail; } /* * Policy - Don't allow a process to FSETOWN a process * in another session. * * Remove this test to allow maximum flexibility or * restrict FSETOWN to the current process or process * group for maximum safety. */ PROC_UNLOCK(proc); if (proc->p_session != curthread->td_proc->p_session) { ret = EPERM; goto fail; } pgrp = NULL; } else /* if (pgid < 0) */ { pgrp = pgfind(-pgid); if (pgrp == NULL) { ret = ESRCH; goto fail; } PGRP_UNLOCK(pgrp); /* * Policy - Don't allow a process to FSETOWN a process * in another session. * * Remove this test to allow maximum flexibility or * restrict FSETOWN to the current process or process * group for maximum safety. */ if (pgrp->pg_session != curthread->td_proc->p_session) { ret = EPERM; goto fail; } proc = NULL; } funsetown(sigiop); if (pgid > 0) { PROC_LOCK(proc); /* * Since funsetownlst() is called without the proctree * locked, we need to check for P_WEXIT. * XXX: is ESRCH correct? */ if ((proc->p_flag & P_WEXIT) != 0) { PROC_UNLOCK(proc); ret = ESRCH; goto fail; } SLIST_INSERT_HEAD(&proc->p_sigiolst, sigio, sio_pgsigio); sigio->sio_proc = proc; PROC_UNLOCK(proc); } else { PGRP_LOCK(pgrp); SLIST_INSERT_HEAD(&pgrp->pg_sigiolst, sigio, sio_pgsigio); sigio->sio_pgrp = pgrp; PGRP_UNLOCK(pgrp); } sx_sunlock(&proctree_lock); SIGIO_LOCK(); *sigiop = sigio; SIGIO_UNLOCK(); return (0); fail: sx_sunlock(&proctree_lock); crfree(sigio->sio_ucred); free(sigio, M_SIGIO); return (ret); } /* * This is common code for FIOGETOWN ioctl called by fcntl(fd, F_GETOWN, arg). */ pid_t fgetown(struct sigio **sigiop) { pid_t pgid; SIGIO_LOCK(); pgid = (*sigiop != NULL) ? (*sigiop)->sio_pgid : 0; SIGIO_UNLOCK(); return (pgid); } /* * Function drops the filedesc lock on return. */ static int closefp(struct filedesc *fdp, int fd, struct file *fp, struct thread *td, int holdleaders) { int error; FILEDESC_XLOCK_ASSERT(fdp); if (holdleaders) { if (td->td_proc->p_fdtol != NULL) { /* * Ask fdfree() to sleep to ensure that all relevant * process leaders can be traversed in closef(). */ fdp->fd_holdleaderscount++; } else { holdleaders = 0; } } /* * We now hold the fp reference that used to be owned by the * descriptor array. We have to unlock the FILEDESC *AFTER* * knote_fdclose to prevent a race of the fd getting opened, a knote * added, and deleteing a knote for the new fd. */ if (__predict_false(!TAILQ_EMPTY(&fdp->fd_kqlist))) knote_fdclose(td, fd); /* * We need to notify mqueue if the object is of type mqueue. */ if (__predict_false(fp->f_type == DTYPE_MQUEUE)) mq_fdclose(td, fd, fp); FILEDESC_XUNLOCK(fdp); error = closef(fp, td); if (holdleaders) { FILEDESC_XLOCK(fdp); fdp->fd_holdleaderscount--; if (fdp->fd_holdleaderscount == 0 && fdp->fd_holdleaderswakeup != 0) { fdp->fd_holdleaderswakeup = 0; wakeup(&fdp->fd_holdleaderscount); } FILEDESC_XUNLOCK(fdp); } return (error); } /* * Close a file descriptor. */ #ifndef _SYS_SYSPROTO_H_ struct close_args { int fd; }; #endif /* ARGSUSED */ int sys_close(struct thread *td, struct close_args *uap) { return (kern_close(td, uap->fd)); } int kern_close(struct thread *td, int fd) { struct filedesc *fdp; struct file *fp; fdp = td->td_proc->p_fd; AUDIT_SYSCLOSE(td, fd); FILEDESC_XLOCK(fdp); if ((fp = fget_locked(fdp, fd)) == NULL) { FILEDESC_XUNLOCK(fdp); return (EBADF); } fdfree(fdp, fd); /* closefp() drops the FILEDESC lock for us. */ return (closefp(fdp, fd, fp, td, 1)); } /* * Close open file descriptors. */ #ifndef _SYS_SYSPROTO_H_ struct closefrom_args { int lowfd; }; #endif /* ARGSUSED */ int sys_closefrom(struct thread *td, struct closefrom_args *uap) { struct filedesc *fdp; int fd; fdp = td->td_proc->p_fd; AUDIT_ARG_FD(uap->lowfd); /* * Treat negative starting file descriptor values identical to * closefrom(0) which closes all files. */ if (uap->lowfd < 0) uap->lowfd = 0; FILEDESC_SLOCK(fdp); for (fd = uap->lowfd; fd <= fdp->fd_lastfile; fd++) { if (fdp->fd_ofiles[fd].fde_file != NULL) { FILEDESC_SUNLOCK(fdp); (void)kern_close(td, fd); FILEDESC_SLOCK(fdp); } } FILEDESC_SUNLOCK(fdp); return (0); } #if defined(COMPAT_43) /* * Return status information about a file descriptor. */ #ifndef _SYS_SYSPROTO_H_ struct ofstat_args { int fd; struct ostat *sb; }; #endif /* ARGSUSED */ int ofstat(struct thread *td, struct ofstat_args *uap) { struct ostat oub; struct stat ub; int error; error = kern_fstat(td, uap->fd, &ub); if (error == 0) { cvtstat(&ub, &oub); error = copyout(&oub, uap->sb, sizeof(oub)); } return (error); } #endif /* COMPAT_43 */ #if defined(COMPAT_FREEBSD11) int freebsd11_fstat(struct thread *td, struct freebsd11_fstat_args *uap) { struct stat sb; struct freebsd11_stat osb; int error; error = kern_fstat(td, uap->fd, &sb); if (error != 0) return (error); error = freebsd11_cvtstat(&sb, &osb); if (error == 0) error = copyout(&osb, uap->sb, sizeof(osb)); return (error); } #endif /* COMPAT_FREEBSD11 */ /* * Return status information about a file descriptor. */ #ifndef _SYS_SYSPROTO_H_ struct fstat_args { int fd; struct stat *sb; }; #endif /* ARGSUSED */ int sys_fstat(struct thread *td, struct fstat_args *uap) { struct stat ub; int error; error = kern_fstat(td, uap->fd, &ub); if (error == 0) error = copyout(&ub, uap->sb, sizeof(ub)); return (error); } int kern_fstat(struct thread *td, int fd, struct stat *sbp) { struct file *fp; int error; AUDIT_ARG_FD(fd); error = fget(td, fd, &cap_fstat_rights, &fp); if (error != 0) return (error); AUDIT_ARG_FILE(td->td_proc, fp); error = fo_stat(fp, sbp, td->td_ucred, td); fdrop(fp, td); #ifdef __STAT_TIME_T_EXT if (error == 0) { sbp->st_atim_ext = 0; sbp->st_mtim_ext = 0; sbp->st_ctim_ext = 0; sbp->st_btim_ext = 0; } #endif #ifdef KTRACE if (error == 0 && KTRPOINT(td, KTR_STRUCT)) ktrstat(sbp); #endif return (error); } #if defined(COMPAT_FREEBSD11) /* * Return status information about a file descriptor. */ #ifndef _SYS_SYSPROTO_H_ struct freebsd11_nfstat_args { int fd; struct nstat *sb; }; #endif /* ARGSUSED */ int freebsd11_nfstat(struct thread *td, struct freebsd11_nfstat_args *uap) { struct nstat nub; struct stat ub; int error; error = kern_fstat(td, uap->fd, &ub); if (error == 0) { freebsd11_cvtnstat(&ub, &nub); error = copyout(&nub, uap->sb, sizeof(nub)); } return (error); } #endif /* COMPAT_FREEBSD11 */ /* * Return pathconf information about a file descriptor. */ #ifndef _SYS_SYSPROTO_H_ struct fpathconf_args { int fd; int name; }; #endif /* ARGSUSED */ int sys_fpathconf(struct thread *td, struct fpathconf_args *uap) { long value; int error; error = kern_fpathconf(td, uap->fd, uap->name, &value); if (error == 0) td->td_retval[0] = value; return (error); } int kern_fpathconf(struct thread *td, int fd, int name, long *valuep) { struct file *fp; struct vnode *vp; int error; error = fget(td, fd, &cap_fpathconf_rights, &fp); if (error != 0) return (error); if (name == _PC_ASYNC_IO) { *valuep = _POSIX_ASYNCHRONOUS_IO; goto out; } vp = fp->f_vnode; if (vp != NULL) { vn_lock(vp, LK_SHARED | LK_RETRY); error = VOP_PATHCONF(vp, name, valuep); VOP_UNLOCK(vp, 0); } else if (fp->f_type == DTYPE_PIPE || fp->f_type == DTYPE_SOCKET) { if (name != _PC_PIPE_BUF) { error = EINVAL; } else { *valuep = PIPE_BUF; error = 0; } } else { error = EOPNOTSUPP; } out: fdrop(fp, td); return (error); } /* - * Initialize filecaps structure. - */ -void -filecaps_init(struct filecaps *fcaps) -{ - - bzero(fcaps, sizeof(*fcaps)); - fcaps->fc_nioctls = -1; -} - -/* * Copy filecaps structure allocating memory for ioctls array if needed. * * The last parameter indicates whether the fdtable is locked. If it is not and * ioctls are encountered, copying fails and the caller must lock the table. * * Note that if the table was not locked, the caller has to check the relevant * sequence counter to determine whether the operation was successful. */ bool filecaps_copy(const struct filecaps *src, struct filecaps *dst, bool locked) { size_t size; if (src->fc_ioctls != NULL && !locked) return (false); memcpy(dst, src, sizeof(*src)); if (src->fc_ioctls == NULL) return (true); KASSERT(src->fc_nioctls > 0, ("fc_ioctls != NULL, but fc_nioctls=%hd", src->fc_nioctls)); size = sizeof(src->fc_ioctls[0]) * src->fc_nioctls; dst->fc_ioctls = malloc(size, M_FILECAPS, M_WAITOK); memcpy(dst->fc_ioctls, src->fc_ioctls, size); return (true); } static u_long * filecaps_copy_prep(const struct filecaps *src) { u_long *ioctls; size_t size; if (__predict_true(src->fc_ioctls == NULL)) return (NULL); KASSERT(src->fc_nioctls > 0, ("fc_ioctls != NULL, but fc_nioctls=%hd", src->fc_nioctls)); size = sizeof(src->fc_ioctls[0]) * src->fc_nioctls; ioctls = malloc(size, M_FILECAPS, M_WAITOK); return (ioctls); } static void filecaps_copy_finish(const struct filecaps *src, struct filecaps *dst, u_long *ioctls) { size_t size; *dst = *src; if (__predict_true(src->fc_ioctls == NULL)) { MPASS(ioctls == NULL); return; } size = sizeof(src->fc_ioctls[0]) * src->fc_nioctls; dst->fc_ioctls = ioctls; bcopy(src->fc_ioctls, dst->fc_ioctls, size); } /* * Move filecaps structure to the new place and clear the old place. */ void filecaps_move(struct filecaps *src, struct filecaps *dst) { *dst = *src; bzero(src, sizeof(*src)); } /* * Fill the given filecaps structure with full rights. */ static void filecaps_fill(struct filecaps *fcaps) { CAP_ALL(&fcaps->fc_rights); fcaps->fc_ioctls = NULL; fcaps->fc_nioctls = -1; fcaps->fc_fcntls = CAP_FCNTL_ALL; } /* * Free memory allocated within filecaps structure. */ void filecaps_free(struct filecaps *fcaps) { free(fcaps->fc_ioctls, M_FILECAPS); bzero(fcaps, sizeof(*fcaps)); } static u_long * filecaps_free_prep(struct filecaps *fcaps) { u_long *ioctls; ioctls = fcaps->fc_ioctls; bzero(fcaps, sizeof(*fcaps)); return (ioctls); } static void filecaps_free_finish(u_long *ioctls) { free(ioctls, M_FILECAPS); } /* * Validate the given filecaps structure. */ static void filecaps_validate(const struct filecaps *fcaps, const char *func) { KASSERT(cap_rights_is_valid(&fcaps->fc_rights), ("%s: invalid rights", func)); KASSERT((fcaps->fc_fcntls & ~CAP_FCNTL_ALL) == 0, ("%s: invalid fcntls", func)); KASSERT(fcaps->fc_fcntls == 0 || cap_rights_is_set(&fcaps->fc_rights, CAP_FCNTL), ("%s: fcntls without CAP_FCNTL", func)); KASSERT(fcaps->fc_ioctls != NULL ? fcaps->fc_nioctls > 0 : (fcaps->fc_nioctls == -1 || fcaps->fc_nioctls == 0), ("%s: invalid ioctls", func)); KASSERT(fcaps->fc_nioctls == 0 || cap_rights_is_set(&fcaps->fc_rights, CAP_IOCTL), ("%s: ioctls without CAP_IOCTL", func)); } static void fdgrowtable_exp(struct filedesc *fdp, int nfd) { int nfd1; FILEDESC_XLOCK_ASSERT(fdp); nfd1 = fdp->fd_nfiles * 2; if (nfd1 < nfd) nfd1 = nfd; fdgrowtable(fdp, nfd1); } /* * Grow the file table to accommodate (at least) nfd descriptors. */ static void fdgrowtable(struct filedesc *fdp, int nfd) { struct filedesc0 *fdp0; struct freetable *ft; struct fdescenttbl *ntable; struct fdescenttbl *otable; int nnfiles, onfiles; NDSLOTTYPE *nmap, *omap; /* * If lastfile is -1 this struct filedesc was just allocated and we are * growing it to accommodate for the one we are going to copy from. There * is no need to have a lock on this one as it's not visible to anyone. */ if (fdp->fd_lastfile != -1) FILEDESC_XLOCK_ASSERT(fdp); KASSERT(fdp->fd_nfiles > 0, ("zero-length file table")); /* save old values */ onfiles = fdp->fd_nfiles; otable = fdp->fd_files; omap = fdp->fd_map; /* compute the size of the new table */ nnfiles = NDSLOTS(nfd) * NDENTRIES; /* round up */ if (nnfiles <= onfiles) /* the table is already large enough */ return; /* * Allocate a new table. We need enough space for the number of * entries, file entries themselves and the struct freetable we will use * when we decommission the table and place it on the freelist. * We place the struct freetable in the middle so we don't have * to worry about padding. */ ntable = malloc(offsetof(struct fdescenttbl, fdt_ofiles) + nnfiles * sizeof(ntable->fdt_ofiles[0]) + sizeof(struct freetable), M_FILEDESC, M_ZERO | M_WAITOK); /* copy the old data */ ntable->fdt_nfiles = nnfiles; memcpy(ntable->fdt_ofiles, otable->fdt_ofiles, onfiles * sizeof(ntable->fdt_ofiles[0])); /* * Allocate a new map only if the old is not large enough. It will * grow at a slower rate than the table as it can map more * entries than the table can hold. */ if (NDSLOTS(nnfiles) > NDSLOTS(onfiles)) { nmap = malloc(NDSLOTS(nnfiles) * NDSLOTSIZE, M_FILEDESC, M_ZERO | M_WAITOK); /* copy over the old data and update the pointer */ memcpy(nmap, omap, NDSLOTS(onfiles) * sizeof(*omap)); fdp->fd_map = nmap; } /* * Make sure that ntable is correctly initialized before we replace * fd_files poiner. Otherwise fget_unlocked() may see inconsistent * data. */ atomic_store_rel_ptr((volatile void *)&fdp->fd_files, (uintptr_t)ntable); /* * Do not free the old file table, as some threads may still * reference entries within it. Instead, place it on a freelist * which will be processed when the struct filedesc is released. * * Note that if onfiles == NDFILE, we're dealing with the original * static allocation contained within (struct filedesc0 *)fdp, * which must not be freed. */ if (onfiles > NDFILE) { ft = (struct freetable *)&otable->fdt_ofiles[onfiles]; fdp0 = (struct filedesc0 *)fdp; ft->ft_table = otable; SLIST_INSERT_HEAD(&fdp0->fd_free, ft, ft_next); } /* * The map does not have the same possibility of threads still * holding references to it. So always free it as long as it * does not reference the original static allocation. */ if (NDSLOTS(onfiles) > NDSLOTS(NDFILE)) free(omap, M_FILEDESC); } /* * Allocate a file descriptor for the process. */ int fdalloc(struct thread *td, int minfd, int *result) { struct proc *p = td->td_proc; struct filedesc *fdp = p->p_fd; int fd, maxfd, allocfd; #ifdef RACCT int error; #endif FILEDESC_XLOCK_ASSERT(fdp); if (fdp->fd_freefile > minfd) minfd = fdp->fd_freefile; maxfd = getmaxfd(td); /* * Search the bitmap for a free descriptor starting at minfd. * If none is found, grow the file table. */ fd = fd_first_free(fdp, minfd, fdp->fd_nfiles); if (fd >= maxfd) return (EMFILE); if (fd >= fdp->fd_nfiles) { allocfd = min(fd * 2, maxfd); #ifdef RACCT if (RACCT_ENABLED()) { error = racct_set_unlocked(p, RACCT_NOFILE, allocfd); if (error != 0) return (EMFILE); } #endif /* * fd is already equal to first free descriptor >= minfd, so * we only need to grow the table and we are done. */ fdgrowtable_exp(fdp, allocfd); } /* * Perform some sanity checks, then mark the file descriptor as * used and return it to the caller. */ KASSERT(fd >= 0 && fd < min(maxfd, fdp->fd_nfiles), ("invalid descriptor %d", fd)); KASSERT(!fdisused(fdp, fd), ("fd_first_free() returned non-free descriptor")); KASSERT(fdp->fd_ofiles[fd].fde_file == NULL, ("file descriptor isn't free")); fdused(fdp, fd); *result = fd; return (0); } /* * Allocate n file descriptors for the process. */ int fdallocn(struct thread *td, int minfd, int *fds, int n) { struct proc *p = td->td_proc; struct filedesc *fdp = p->p_fd; int i; FILEDESC_XLOCK_ASSERT(fdp); for (i = 0; i < n; i++) if (fdalloc(td, 0, &fds[i]) != 0) break; if (i < n) { for (i--; i >= 0; i--) fdunused(fdp, fds[i]); return (EMFILE); } return (0); } /* * Create a new open file structure and allocate a file descriptor for the * process that refers to it. We add one reference to the file for the * descriptor table and one reference for resultfp. This is to prevent us * being preempted and the entry in the descriptor table closed after we * release the FILEDESC lock. */ int falloc_caps(struct thread *td, struct file **resultfp, int *resultfd, int flags, struct filecaps *fcaps) { struct file *fp; int error, fd; error = falloc_noinstall(td, &fp); if (error) return (error); /* no reference held on error */ error = finstall(td, fp, &fd, flags, fcaps); if (error) { fdrop(fp, td); /* one reference (fp only) */ return (error); } if (resultfp != NULL) *resultfp = fp; /* copy out result */ else fdrop(fp, td); /* release local reference */ if (resultfd != NULL) *resultfd = fd; return (0); } /* * Create a new open file structure without allocating a file descriptor. */ int falloc_noinstall(struct thread *td, struct file **resultfp) { struct file *fp; int maxuserfiles = maxfiles - (maxfiles / 20); int openfiles_new; static struct timeval lastfail; static int curfail; KASSERT(resultfp != NULL, ("%s: resultfp == NULL", __func__)); openfiles_new = atomic_fetchadd_int(&openfiles, 1) + 1; if ((openfiles_new >= maxuserfiles && priv_check(td, PRIV_MAXFILES) != 0) || openfiles_new >= maxfiles) { atomic_subtract_int(&openfiles, 1); if (ppsratecheck(&lastfail, &curfail, 1)) { printf("kern.maxfiles limit exceeded by uid %i, (%s) " "please see tuning(7).\n", td->td_ucred->cr_ruid, td->td_proc->p_comm); } return (ENFILE); } fp = uma_zalloc(file_zone, M_WAITOK); bzero(fp, sizeof(*fp)); refcount_init(&fp->f_count, 1); fp->f_cred = crhold(td->td_ucred); fp->f_ops = &badfileops; *resultfp = fp; return (0); } /* * Install a file in a file descriptor table. */ void _finstall(struct filedesc *fdp, struct file *fp, int fd, int flags, struct filecaps *fcaps) { struct filedescent *fde; MPASS(fp != NULL); if (fcaps != NULL) filecaps_validate(fcaps, __func__); FILEDESC_XLOCK_ASSERT(fdp); fde = &fdp->fd_ofiles[fd]; #ifdef CAPABILITIES seq_write_begin(&fde->fde_seq); #endif fde->fde_file = fp; fde->fde_flags = (flags & O_CLOEXEC) != 0 ? UF_EXCLOSE : 0; if (fcaps != NULL) filecaps_move(fcaps, &fde->fde_caps); else filecaps_fill(&fde->fde_caps); #ifdef CAPABILITIES seq_write_end(&fde->fde_seq); #endif } int finstall(struct thread *td, struct file *fp, int *fd, int flags, struct filecaps *fcaps) { struct filedesc *fdp = td->td_proc->p_fd; int error; MPASS(fd != NULL); FILEDESC_XLOCK(fdp); if ((error = fdalloc(td, 0, fd))) { FILEDESC_XUNLOCK(fdp); return (error); } fhold(fp); _finstall(fdp, fp, *fd, flags, fcaps); FILEDESC_XUNLOCK(fdp); return (0); } /* * Build a new filedesc structure from another. * Copy the current, root, and jail root vnode references. * * If fdp is not NULL, return with it shared locked. */ struct filedesc * fdinit(struct filedesc *fdp, bool prepfiles) { struct filedesc0 *newfdp0; struct filedesc *newfdp; newfdp0 = uma_zalloc(filedesc0_zone, M_WAITOK | M_ZERO); newfdp = &newfdp0->fd_fd; /* Create the file descriptor table. */ FILEDESC_LOCK_INIT(newfdp); refcount_init(&newfdp->fd_refcnt, 1); refcount_init(&newfdp->fd_holdcnt, 1); newfdp->fd_cmask = CMASK; newfdp->fd_map = newfdp0->fd_dmap; newfdp->fd_lastfile = -1; newfdp->fd_files = (struct fdescenttbl *)&newfdp0->fd_dfiles; newfdp->fd_files->fdt_nfiles = NDFILE; if (fdp == NULL) return (newfdp); if (prepfiles && fdp->fd_lastfile >= newfdp->fd_nfiles) fdgrowtable(newfdp, fdp->fd_lastfile + 1); FILEDESC_SLOCK(fdp); newfdp->fd_cdir = fdp->fd_cdir; if (newfdp->fd_cdir) vrefact(newfdp->fd_cdir); newfdp->fd_rdir = fdp->fd_rdir; if (newfdp->fd_rdir) vrefact(newfdp->fd_rdir); newfdp->fd_jdir = fdp->fd_jdir; if (newfdp->fd_jdir) vrefact(newfdp->fd_jdir); if (!prepfiles) { FILEDESC_SUNLOCK(fdp); } else { while (fdp->fd_lastfile >= newfdp->fd_nfiles) { FILEDESC_SUNLOCK(fdp); fdgrowtable(newfdp, fdp->fd_lastfile + 1); FILEDESC_SLOCK(fdp); } } return (newfdp); } static struct filedesc * fdhold(struct proc *p) { struct filedesc *fdp; PROC_LOCK_ASSERT(p, MA_OWNED); fdp = p->p_fd; if (fdp != NULL) refcount_acquire(&fdp->fd_holdcnt); return (fdp); } static void fddrop(struct filedesc *fdp) { if (fdp->fd_holdcnt > 1) { if (refcount_release(&fdp->fd_holdcnt) == 0) return; } FILEDESC_LOCK_DESTROY(fdp); uma_zfree(filedesc0_zone, fdp); } /* * Share a filedesc structure. */ struct filedesc * fdshare(struct filedesc *fdp) { refcount_acquire(&fdp->fd_refcnt); return (fdp); } /* * Unshare a filedesc structure, if necessary by making a copy */ void fdunshare(struct thread *td) { struct filedesc *tmp; struct proc *p = td->td_proc; if (p->p_fd->fd_refcnt == 1) return; tmp = fdcopy(p->p_fd); fdescfree(td); p->p_fd = tmp; } void fdinstall_remapped(struct thread *td, struct filedesc *fdp) { fdescfree(td); td->td_proc->p_fd = fdp; } /* * Copy a filedesc structure. A NULL pointer in returns a NULL reference, * this is to ease callers, not catch errors. */ struct filedesc * fdcopy(struct filedesc *fdp) { struct filedesc *newfdp; struct filedescent *nfde, *ofde; int i; MPASS(fdp != NULL); newfdp = fdinit(fdp, true); /* copy all passable descriptors (i.e. not kqueue) */ newfdp->fd_freefile = -1; for (i = 0; i <= fdp->fd_lastfile; ++i) { ofde = &fdp->fd_ofiles[i]; if (ofde->fde_file == NULL || (ofde->fde_file->f_ops->fo_flags & DFLAG_PASSABLE) == 0) { if (newfdp->fd_freefile == -1) newfdp->fd_freefile = i; continue; } nfde = &newfdp->fd_ofiles[i]; *nfde = *ofde; filecaps_copy(&ofde->fde_caps, &nfde->fde_caps, true); fhold(nfde->fde_file); fdused_init(newfdp, i); newfdp->fd_lastfile = i; } if (newfdp->fd_freefile == -1) newfdp->fd_freefile = i; newfdp->fd_cmask = fdp->fd_cmask; FILEDESC_SUNLOCK(fdp); return (newfdp); } /* * Copies a filedesc structure, while remapping all file descriptors * stored inside using a translation table. * * File descriptors are copied over to the new file descriptor table, * regardless of whether the close-on-exec flag is set. */ int fdcopy_remapped(struct filedesc *fdp, const int *fds, size_t nfds, struct filedesc **ret) { struct filedesc *newfdp; struct filedescent *nfde, *ofde; int error, i; MPASS(fdp != NULL); newfdp = fdinit(fdp, true); if (nfds > fdp->fd_lastfile + 1) { /* New table cannot be larger than the old one. */ error = E2BIG; goto bad; } /* Copy all passable descriptors (i.e. not kqueue). */ newfdp->fd_freefile = nfds; for (i = 0; i < nfds; ++i) { if (fds[i] < 0 || fds[i] > fdp->fd_lastfile) { /* File descriptor out of bounds. */ error = EBADF; goto bad; } ofde = &fdp->fd_ofiles[fds[i]]; if (ofde->fde_file == NULL) { /* Unused file descriptor. */ error = EBADF; goto bad; } if ((ofde->fde_file->f_ops->fo_flags & DFLAG_PASSABLE) == 0) { /* File descriptor cannot be passed. */ error = EINVAL; goto bad; } nfde = &newfdp->fd_ofiles[i]; *nfde = *ofde; filecaps_copy(&ofde->fde_caps, &nfde->fde_caps, true); fhold(nfde->fde_file); fdused_init(newfdp, i); newfdp->fd_lastfile = i; } newfdp->fd_cmask = fdp->fd_cmask; FILEDESC_SUNLOCK(fdp); *ret = newfdp; return (0); bad: FILEDESC_SUNLOCK(fdp); fdescfree_remapped(newfdp); return (error); } /* * Clear POSIX style locks. This is only used when fdp looses a reference (i.e. * one of processes using it exits) and the table used to be shared. */ static void fdclearlocks(struct thread *td) { struct filedesc *fdp; struct filedesc_to_leader *fdtol; struct flock lf; struct file *fp; struct proc *p; struct vnode *vp; int i; p = td->td_proc; fdp = p->p_fd; fdtol = p->p_fdtol; MPASS(fdtol != NULL); FILEDESC_XLOCK(fdp); KASSERT(fdtol->fdl_refcount > 0, ("filedesc_to_refcount botch: fdl_refcount=%d", fdtol->fdl_refcount)); if (fdtol->fdl_refcount == 1 && (p->p_leader->p_flag & P_ADVLOCK) != 0) { for (i = 0; i <= fdp->fd_lastfile; i++) { fp = fdp->fd_ofiles[i].fde_file; if (fp == NULL || fp->f_type != DTYPE_VNODE) continue; fhold(fp); FILEDESC_XUNLOCK(fdp); lf.l_whence = SEEK_SET; lf.l_start = 0; lf.l_len = 0; lf.l_type = F_UNLCK; vp = fp->f_vnode; (void) VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_UNLCK, &lf, F_POSIX); FILEDESC_XLOCK(fdp); fdrop(fp, td); } } retry: if (fdtol->fdl_refcount == 1) { if (fdp->fd_holdleaderscount > 0 && (p->p_leader->p_flag & P_ADVLOCK) != 0) { /* * close() or kern_dup() has cleared a reference * in a shared file descriptor table. */ fdp->fd_holdleaderswakeup = 1; sx_sleep(&fdp->fd_holdleaderscount, FILEDESC_LOCK(fdp), PLOCK, "fdlhold", 0); goto retry; } if (fdtol->fdl_holdcount > 0) { /* * Ensure that fdtol->fdl_leader remains * valid in closef(). */ fdtol->fdl_wakeup = 1; sx_sleep(fdtol, FILEDESC_LOCK(fdp), PLOCK, "fdlhold", 0); goto retry; } } fdtol->fdl_refcount--; if (fdtol->fdl_refcount == 0 && fdtol->fdl_holdcount == 0) { fdtol->fdl_next->fdl_prev = fdtol->fdl_prev; fdtol->fdl_prev->fdl_next = fdtol->fdl_next; } else fdtol = NULL; p->p_fdtol = NULL; FILEDESC_XUNLOCK(fdp); if (fdtol != NULL) free(fdtol, M_FILEDESC_TO_LEADER); } /* * Release a filedesc structure. */ static void fdescfree_fds(struct thread *td, struct filedesc *fdp, bool needclose) { struct filedesc0 *fdp0; struct freetable *ft, *tft; struct filedescent *fde; struct file *fp; int i; for (i = 0; i <= fdp->fd_lastfile; i++) { fde = &fdp->fd_ofiles[i]; fp = fde->fde_file; if (fp != NULL) { fdefree_last(fde); if (needclose) (void) closef(fp, td); else fdrop(fp, td); } } if (NDSLOTS(fdp->fd_nfiles) > NDSLOTS(NDFILE)) free(fdp->fd_map, M_FILEDESC); if (fdp->fd_nfiles > NDFILE) free(fdp->fd_files, M_FILEDESC); fdp0 = (struct filedesc0 *)fdp; SLIST_FOREACH_SAFE(ft, &fdp0->fd_free, ft_next, tft) free(ft->ft_table, M_FILEDESC); fddrop(fdp); } void fdescfree(struct thread *td) { struct proc *p; struct filedesc *fdp; struct vnode *cdir, *jdir, *rdir; p = td->td_proc; fdp = p->p_fd; MPASS(fdp != NULL); #ifdef RACCT if (RACCT_ENABLED()) racct_set_unlocked(p, RACCT_NOFILE, 0); #endif if (p->p_fdtol != NULL) fdclearlocks(td); PROC_LOCK(p); p->p_fd = NULL; PROC_UNLOCK(p); if (refcount_release(&fdp->fd_refcnt) == 0) return; FILEDESC_XLOCK(fdp); cdir = fdp->fd_cdir; fdp->fd_cdir = NULL; rdir = fdp->fd_rdir; fdp->fd_rdir = NULL; jdir = fdp->fd_jdir; fdp->fd_jdir = NULL; FILEDESC_XUNLOCK(fdp); if (cdir != NULL) vrele(cdir); if (rdir != NULL) vrele(rdir); if (jdir != NULL) vrele(jdir); fdescfree_fds(td, fdp, 1); } void fdescfree_remapped(struct filedesc *fdp) { if (fdp->fd_cdir != NULL) vrele(fdp->fd_cdir); if (fdp->fd_rdir != NULL) vrele(fdp->fd_rdir); if (fdp->fd_jdir != NULL) vrele(fdp->fd_jdir); fdescfree_fds(curthread, fdp, 0); } /* * For setugid programs, we don't want to people to use that setugidness * to generate error messages which write to a file which otherwise would * otherwise be off-limits to the process. We check for filesystems where * the vnode can change out from under us after execve (like [lin]procfs). * * Since fdsetugidsafety calls this only for fd 0, 1 and 2, this check is * sufficient. We also don't check for setugidness since we know we are. */ static bool is_unsafe(struct file *fp) { struct vnode *vp; if (fp->f_type != DTYPE_VNODE) return (false); vp = fp->f_vnode; return ((vp->v_vflag & VV_PROCDEP) != 0); } /* * Make this setguid thing safe, if at all possible. */ void fdsetugidsafety(struct thread *td) { struct filedesc *fdp; struct file *fp; int i; fdp = td->td_proc->p_fd; KASSERT(fdp->fd_refcnt == 1, ("the fdtable should not be shared")); MPASS(fdp->fd_nfiles >= 3); for (i = 0; i <= 2; i++) { fp = fdp->fd_ofiles[i].fde_file; if (fp != NULL && is_unsafe(fp)) { FILEDESC_XLOCK(fdp); knote_fdclose(td, i); /* * NULL-out descriptor prior to close to avoid * a race while close blocks. */ fdfree(fdp, i); FILEDESC_XUNLOCK(fdp); (void) closef(fp, td); } } } /* * If a specific file object occupies a specific file descriptor, close the * file descriptor entry and drop a reference on the file object. This is a * convenience function to handle a subsequent error in a function that calls * falloc() that handles the race that another thread might have closed the * file descriptor out from under the thread creating the file object. */ void fdclose(struct thread *td, struct file *fp, int idx) { struct filedesc *fdp = td->td_proc->p_fd; FILEDESC_XLOCK(fdp); if (fdp->fd_ofiles[idx].fde_file == fp) { fdfree(fdp, idx); FILEDESC_XUNLOCK(fdp); fdrop(fp, td); } else FILEDESC_XUNLOCK(fdp); } /* * Close any files on exec? */ void fdcloseexec(struct thread *td) { struct filedesc *fdp; struct filedescent *fde; struct file *fp; int i; fdp = td->td_proc->p_fd; KASSERT(fdp->fd_refcnt == 1, ("the fdtable should not be shared")); for (i = 0; i <= fdp->fd_lastfile; i++) { fde = &fdp->fd_ofiles[i]; fp = fde->fde_file; if (fp != NULL && (fp->f_type == DTYPE_MQUEUE || (fde->fde_flags & UF_EXCLOSE))) { FILEDESC_XLOCK(fdp); fdfree(fdp, i); (void) closefp(fdp, i, fp, td, 0); FILEDESC_UNLOCK_ASSERT(fdp); } } } /* * It is unsafe for set[ug]id processes to be started with file * descriptors 0..2 closed, as these descriptors are given implicit * significance in the Standard C library. fdcheckstd() will create a * descriptor referencing /dev/null for each of stdin, stdout, and * stderr that is not already open. */ int fdcheckstd(struct thread *td) { struct filedesc *fdp; register_t save; int i, error, devnull; fdp = td->td_proc->p_fd; KASSERT(fdp->fd_refcnt == 1, ("the fdtable should not be shared")); MPASS(fdp->fd_nfiles >= 3); devnull = -1; for (i = 0; i <= 2; i++) { if (fdp->fd_ofiles[i].fde_file != NULL) continue; save = td->td_retval[0]; if (devnull != -1) { error = kern_dup(td, FDDUP_FIXED, 0, devnull, i); } else { error = kern_openat(td, AT_FDCWD, "/dev/null", UIO_SYSSPACE, O_RDWR, 0); if (error == 0) { devnull = td->td_retval[0]; KASSERT(devnull == i, ("we didn't get our fd")); } } td->td_retval[0] = save; if (error != 0) return (error); } return (0); } /* * Internal form of close. Decrement reference count on file structure. * Note: td may be NULL when closing a file that was being passed in a * message. * * XXXRW: Giant is not required for the caller, but often will be held; this * makes it moderately likely the Giant will be recursed in the VFS case. */ int closef(struct file *fp, struct thread *td) { struct vnode *vp; struct flock lf; struct filedesc_to_leader *fdtol; struct filedesc *fdp; /* * POSIX record locking dictates that any close releases ALL * locks owned by this process. This is handled by setting * a flag in the unlock to free ONLY locks obeying POSIX * semantics, and not to free BSD-style file locks. * If the descriptor was in a message, POSIX-style locks * aren't passed with the descriptor, and the thread pointer * will be NULL. Callers should be careful only to pass a * NULL thread pointer when there really is no owning * context that might have locks, or the locks will be * leaked. */ if (fp->f_type == DTYPE_VNODE && td != NULL) { vp = fp->f_vnode; if ((td->td_proc->p_leader->p_flag & P_ADVLOCK) != 0) { lf.l_whence = SEEK_SET; lf.l_start = 0; lf.l_len = 0; lf.l_type = F_UNLCK; (void) VOP_ADVLOCK(vp, (caddr_t)td->td_proc->p_leader, F_UNLCK, &lf, F_POSIX); } fdtol = td->td_proc->p_fdtol; if (fdtol != NULL) { /* * Handle special case where file descriptor table is * shared between multiple process leaders. */ fdp = td->td_proc->p_fd; FILEDESC_XLOCK(fdp); for (fdtol = fdtol->fdl_next; fdtol != td->td_proc->p_fdtol; fdtol = fdtol->fdl_next) { if ((fdtol->fdl_leader->p_flag & P_ADVLOCK) == 0) continue; fdtol->fdl_holdcount++; FILEDESC_XUNLOCK(fdp); lf.l_whence = SEEK_SET; lf.l_start = 0; lf.l_len = 0; lf.l_type = F_UNLCK; vp = fp->f_vnode; (void) VOP_ADVLOCK(vp, (caddr_t)fdtol->fdl_leader, F_UNLCK, &lf, F_POSIX); FILEDESC_XLOCK(fdp); fdtol->fdl_holdcount--; if (fdtol->fdl_holdcount == 0 && fdtol->fdl_wakeup != 0) { fdtol->fdl_wakeup = 0; wakeup(fdtol); } } FILEDESC_XUNLOCK(fdp); } } return (fdrop(fp, td)); } /* * Initialize the file pointer with the specified properties. * * The ops are set with release semantics to be certain that the flags, type, * and data are visible when ops is. This is to prevent ops methods from being * called with bad data. */ void finit(struct file *fp, u_int flag, short type, void *data, struct fileops *ops) { fp->f_data = data; fp->f_flag = flag; fp->f_type = type; atomic_store_rel_ptr((volatile uintptr_t *)&fp->f_ops, (uintptr_t)ops); } int fget_cap_locked(struct filedesc *fdp, int fd, cap_rights_t *needrightsp, struct file **fpp, struct filecaps *havecapsp) { struct filedescent *fde; int error; FILEDESC_LOCK_ASSERT(fdp); fde = fdeget_locked(fdp, fd); if (fde == NULL) { error = EBADF; goto out; } #ifdef CAPABILITIES error = cap_check(cap_rights_fde_inline(fde), needrightsp); if (error != 0) goto out; #endif if (havecapsp != NULL) filecaps_copy(&fde->fde_caps, havecapsp, true); *fpp = fde->fde_file; error = 0; out: return (error); } int fget_cap(struct thread *td, int fd, cap_rights_t *needrightsp, struct file **fpp, struct filecaps *havecapsp) { struct filedesc *fdp = td->td_proc->p_fd; int error; #ifndef CAPABILITIES error = fget_unlocked(fdp, fd, needrightsp, fpp, NULL); if (error == 0 && havecapsp != NULL) filecaps_fill(havecapsp); #else struct file *fp; seq_t seq; for (;;) { error = fget_unlocked(fdp, fd, needrightsp, &fp, &seq); if (error != 0) return (error); if (havecapsp != NULL) { if (!filecaps_copy(&fdp->fd_ofiles[fd].fde_caps, havecapsp, false)) { fdrop(fp, td); goto get_locked; } } if (!fd_modified(fdp, fd, seq)) break; fdrop(fp, td); } *fpp = fp; return (0); get_locked: FILEDESC_SLOCK(fdp); error = fget_cap_locked(fdp, fd, needrightsp, fpp, havecapsp); if (error == 0) fhold(*fpp); FILEDESC_SUNLOCK(fdp); #endif return (error); } int fget_unlocked(struct filedesc *fdp, int fd, cap_rights_t *needrightsp, struct file **fpp, seq_t *seqp) { #ifdef CAPABILITIES const struct filedescent *fde; #endif const struct fdescenttbl *fdt; struct file *fp; u_int count; #ifdef CAPABILITIES seq_t seq; cap_rights_t haverights; int error; #endif fdt = fdp->fd_files; if (__predict_false((u_int)fd >= fdt->fdt_nfiles)) return (EBADF); /* * Fetch the descriptor locklessly. We avoid fdrop() races by * never raising a refcount above 0. To accomplish this we have * to use a cmpset loop rather than an atomic_add. The descriptor * must be re-verified once we acquire a reference to be certain * that the identity is still correct and we did not lose a race * due to preemption. */ for (;;) { #ifdef CAPABILITIES seq = seq_read(fd_seq(fdt, fd)); fde = &fdt->fdt_ofiles[fd]; haverights = *cap_rights_fde_inline(fde); fp = fde->fde_file; if (!seq_consistent(fd_seq(fdt, fd), seq)) continue; #else fp = fdt->fdt_ofiles[fd].fde_file; #endif if (fp == NULL) return (EBADF); #ifdef CAPABILITIES error = cap_check(&haverights, needrightsp); if (error != 0) return (error); #endif count = fp->f_count; retry: if (count == 0) { /* * Force a reload. Other thread could reallocate the * table before this fd was closed, so it possible that * there is a stale fp pointer in cached version. */ fdt = *(const struct fdescenttbl * const volatile *)&(fdp->fd_files); continue; } /* * Use an acquire barrier to force re-reading of fdt so it is * refreshed for verification. */ if (atomic_fcmpset_acq_int(&fp->f_count, &count, count + 1) == 0) goto retry; fdt = fdp->fd_files; #ifdef CAPABILITIES if (seq_consistent_nomb(fd_seq(fdt, fd), seq)) #else if (fp == fdt->fdt_ofiles[fd].fde_file) #endif break; fdrop(fp, curthread); } *fpp = fp; if (seqp != NULL) { #ifdef CAPABILITIES *seqp = seq; #endif } return (0); } /* * Extract the file pointer associated with the specified descriptor for the * current user process. * * If the descriptor doesn't exist or doesn't match 'flags', EBADF is * returned. * * File's rights will be checked against the capability rights mask. * * If an error occurred the non-zero error is returned and *fpp is set to * NULL. Otherwise *fpp is held and set and zero is returned. Caller is * responsible for fdrop(). */ static __inline int _fget(struct thread *td, int fd, struct file **fpp, int flags, cap_rights_t *needrightsp, seq_t *seqp) { struct filedesc *fdp; struct file *fp; int error; *fpp = NULL; fdp = td->td_proc->p_fd; error = fget_unlocked(fdp, fd, needrightsp, &fp, seqp); if (error != 0) return (error); if (fp->f_ops == &badfileops) { fdrop(fp, td); return (EBADF); } /* * FREAD and FWRITE failure return EBADF as per POSIX. */ error = 0; switch (flags) { case FREAD: case FWRITE: if ((fp->f_flag & flags) == 0) error = EBADF; break; case FEXEC: if ((fp->f_flag & (FREAD | FEXEC)) == 0 || ((fp->f_flag & FWRITE) != 0)) error = EBADF; break; case 0: break; default: KASSERT(0, ("wrong flags")); } if (error != 0) { fdrop(fp, td); return (error); } *fpp = fp; return (0); } int fget(struct thread *td, int fd, cap_rights_t *rightsp, struct file **fpp) { return (_fget(td, fd, fpp, 0, rightsp, NULL)); } int fget_mmap(struct thread *td, int fd, cap_rights_t *rightsp, u_char *maxprotp, struct file **fpp) { int error; #ifndef CAPABILITIES error = _fget(td, fd, fpp, 0, rightsp, NULL); if (maxprotp != NULL) *maxprotp = VM_PROT_ALL; #else struct filedesc *fdp = td->td_proc->p_fd; seq_t seq; MPASS(cap_rights_is_set(rightsp, CAP_MMAP)); for (;;) { error = _fget(td, fd, fpp, 0, rightsp, &seq); if (error != 0) return (error); /* * If requested, convert capability rights to access flags. */ if (maxprotp != NULL) *maxprotp = cap_rights_to_vmprot(cap_rights(fdp, fd)); if (!fd_modified(fdp, fd, seq)) break; fdrop(*fpp, td); } #endif return (error); } int fget_read(struct thread *td, int fd, cap_rights_t *rightsp, struct file **fpp) { return (_fget(td, fd, fpp, FREAD, rightsp, NULL)); } int fget_write(struct thread *td, int fd, cap_rights_t *rightsp, struct file **fpp) { return (_fget(td, fd, fpp, FWRITE, rightsp, NULL)); } int fget_fcntl(struct thread *td, int fd, cap_rights_t *rightsp, int needfcntl, struct file **fpp) { struct filedesc *fdp = td->td_proc->p_fd; #ifndef CAPABILITIES return (fget_unlocked(fdp, fd, rightsp, fpp, NULL)); #else int error; seq_t seq; MPASS(cap_rights_is_set(rightsp, CAP_FCNTL)); for (;;) { error = fget_unlocked(fdp, fd, rightsp, fpp, &seq); if (error != 0) return (error); error = cap_fcntl_check(fdp, fd, needfcntl); if (!fd_modified(fdp, fd, seq)) break; fdrop(*fpp, td); } if (error != 0) { fdrop(*fpp, td); *fpp = NULL; } return (error); #endif } /* * Like fget() but loads the underlying vnode, or returns an error if the * descriptor does not represent a vnode. Note that pipes use vnodes but * never have VM objects. The returned vnode will be vref()'d. * * XXX: what about the unused flags ? */ static __inline int _fgetvp(struct thread *td, int fd, int flags, cap_rights_t *needrightsp, struct vnode **vpp) { struct file *fp; int error; *vpp = NULL; error = _fget(td, fd, &fp, flags, needrightsp, NULL); if (error != 0) return (error); if (fp->f_vnode == NULL) { error = EINVAL; } else { *vpp = fp->f_vnode; vrefact(*vpp); } fdrop(fp, td); return (error); } int fgetvp(struct thread *td, int fd, cap_rights_t *rightsp, struct vnode **vpp) { return (_fgetvp(td, fd, 0, rightsp, vpp)); } int fgetvp_rights(struct thread *td, int fd, cap_rights_t *needrightsp, struct filecaps *havecaps, struct vnode **vpp) { struct filedesc *fdp; struct filecaps caps; struct file *fp; int error; fdp = td->td_proc->p_fd; error = fget_cap_locked(fdp, fd, needrightsp, &fp, &caps); if (error != 0) return (error); if (fp->f_ops == &badfileops) { error = EBADF; goto out; } if (fp->f_vnode == NULL) { error = EINVAL; goto out; } *havecaps = caps; *vpp = fp->f_vnode; vrefact(*vpp); return (0); out: filecaps_free(&caps); return (error); } int fgetvp_read(struct thread *td, int fd, cap_rights_t *rightsp, struct vnode **vpp) { return (_fgetvp(td, fd, FREAD, rightsp, vpp)); } int fgetvp_exec(struct thread *td, int fd, cap_rights_t *rightsp, struct vnode **vpp) { return (_fgetvp(td, fd, FEXEC, rightsp, vpp)); } #ifdef notyet int fgetvp_write(struct thread *td, int fd, cap_rights_t *rightsp, struct vnode **vpp) { return (_fgetvp(td, fd, FWRITE, rightsp, vpp)); } #endif /* * Handle the last reference to a file being closed. * * Without the noinline attribute clang keeps inlining the func thorough this * file when fdrop is used. */ int __noinline _fdrop(struct file *fp, struct thread *td) { int error; if (fp->f_count != 0) panic("fdrop: count %d", fp->f_count); error = fo_close(fp, td); atomic_subtract_int(&openfiles, 1); crfree(fp->f_cred); free(fp->f_advice, M_FADVISE); uma_zfree(file_zone, fp); return (error); } /* * Apply an advisory lock on a file descriptor. * * Just attempt to get a record lock of the requested type on the entire file * (l_whence = SEEK_SET, l_start = 0, l_len = 0). */ #ifndef _SYS_SYSPROTO_H_ struct flock_args { int fd; int how; }; #endif /* ARGSUSED */ int sys_flock(struct thread *td, struct flock_args *uap) { struct file *fp; struct vnode *vp; struct flock lf; int error; error = fget(td, uap->fd, &cap_flock_rights, &fp); if (error != 0) return (error); if (fp->f_type != DTYPE_VNODE) { fdrop(fp, td); return (EOPNOTSUPP); } vp = fp->f_vnode; lf.l_whence = SEEK_SET; lf.l_start = 0; lf.l_len = 0; if (uap->how & LOCK_UN) { lf.l_type = F_UNLCK; atomic_clear_int(&fp->f_flag, FHASLOCK); error = VOP_ADVLOCK(vp, (caddr_t)fp, F_UNLCK, &lf, F_FLOCK); goto done2; } if (uap->how & LOCK_EX) lf.l_type = F_WRLCK; else if (uap->how & LOCK_SH) lf.l_type = F_RDLCK; else { error = EBADF; goto done2; } atomic_set_int(&fp->f_flag, FHASLOCK); error = VOP_ADVLOCK(vp, (caddr_t)fp, F_SETLK, &lf, (uap->how & LOCK_NB) ? F_FLOCK : F_FLOCK | F_WAIT); done2: fdrop(fp, td); return (error); } /* * Duplicate the specified descriptor to a free descriptor. */ int dupfdopen(struct thread *td, struct filedesc *fdp, int dfd, int mode, int openerror, int *indxp) { struct filedescent *newfde, *oldfde; struct file *fp; u_long *ioctls; int error, indx; KASSERT(openerror == ENODEV || openerror == ENXIO, ("unexpected error %d in %s", openerror, __func__)); /* * If the to-be-dup'd fd number is greater than the allowed number * of file descriptors, or the fd to be dup'd has already been * closed, then reject. */ FILEDESC_XLOCK(fdp); if ((fp = fget_locked(fdp, dfd)) == NULL) { FILEDESC_XUNLOCK(fdp); return (EBADF); } error = fdalloc(td, 0, &indx); if (error != 0) { FILEDESC_XUNLOCK(fdp); return (error); } /* * There are two cases of interest here. * * For ENODEV simply dup (dfd) to file descriptor (indx) and return. * * For ENXIO steal away the file structure from (dfd) and store it in * (indx). (dfd) is effectively closed by this operation. */ switch (openerror) { case ENODEV: /* * Check that the mode the file is being opened for is a * subset of the mode of the existing descriptor. */ if (((mode & (FREAD|FWRITE)) | fp->f_flag) != fp->f_flag) { fdunused(fdp, indx); FILEDESC_XUNLOCK(fdp); return (EACCES); } fhold(fp); newfde = &fdp->fd_ofiles[indx]; oldfde = &fdp->fd_ofiles[dfd]; ioctls = filecaps_copy_prep(&oldfde->fde_caps); #ifdef CAPABILITIES seq_write_begin(&newfde->fde_seq); #endif memcpy(newfde, oldfde, fde_change_size); filecaps_copy_finish(&oldfde->fde_caps, &newfde->fde_caps, ioctls); #ifdef CAPABILITIES seq_write_end(&newfde->fde_seq); #endif break; case ENXIO: /* * Steal away the file pointer from dfd and stuff it into indx. */ newfde = &fdp->fd_ofiles[indx]; oldfde = &fdp->fd_ofiles[dfd]; #ifdef CAPABILITIES seq_write_begin(&newfde->fde_seq); #endif memcpy(newfde, oldfde, fde_change_size); oldfde->fde_file = NULL; fdunused(fdp, dfd); #ifdef CAPABILITIES seq_write_end(&newfde->fde_seq); #endif break; } FILEDESC_XUNLOCK(fdp); *indxp = indx; return (0); } /* * This sysctl determines if we will allow a process to chroot(2) if it * has a directory open: * 0: disallowed for all processes. * 1: allowed for processes that were not already chroot(2)'ed. * 2: allowed for all processes. */ static int chroot_allow_open_directories = 1; SYSCTL_INT(_kern, OID_AUTO, chroot_allow_open_directories, CTLFLAG_RW, &chroot_allow_open_directories, 0, "Allow a process to chroot(2) if it has a directory open"); /* * Helper function for raised chroot(2) security function: Refuse if * any filedescriptors are open directories. */ static int chroot_refuse_vdir_fds(struct filedesc *fdp) { struct vnode *vp; struct file *fp; int fd; FILEDESC_LOCK_ASSERT(fdp); for (fd = 0; fd <= fdp->fd_lastfile; fd++) { fp = fget_locked(fdp, fd); if (fp == NULL) continue; if (fp->f_type == DTYPE_VNODE) { vp = fp->f_vnode; if (vp->v_type == VDIR) return (EPERM); } } return (0); } /* * Common routine for kern_chroot() and jail_attach(). The caller is * responsible for invoking priv_check() and mac_vnode_check_chroot() to * authorize this operation. */ int pwd_chroot(struct thread *td, struct vnode *vp) { struct filedesc *fdp; struct vnode *oldvp; int error; fdp = td->td_proc->p_fd; FILEDESC_XLOCK(fdp); if (chroot_allow_open_directories == 0 || (chroot_allow_open_directories == 1 && fdp->fd_rdir != rootvnode)) { error = chroot_refuse_vdir_fds(fdp); if (error != 0) { FILEDESC_XUNLOCK(fdp); return (error); } } oldvp = fdp->fd_rdir; vrefact(vp); fdp->fd_rdir = vp; if (fdp->fd_jdir == NULL) { vrefact(vp); fdp->fd_jdir = vp; } FILEDESC_XUNLOCK(fdp); vrele(oldvp); return (0); } void pwd_chdir(struct thread *td, struct vnode *vp) { struct filedesc *fdp; struct vnode *oldvp; fdp = td->td_proc->p_fd; FILEDESC_XLOCK(fdp); VNASSERT(vp->v_usecount > 0, vp, ("chdir to a vnode with zero usecount")); oldvp = fdp->fd_cdir; fdp->fd_cdir = vp; FILEDESC_XUNLOCK(fdp); vrele(oldvp); } /* * Scan all active processes and prisons to see if any of them have a current * or root directory of `olddp'. If so, replace them with the new mount point. */ void mountcheckdirs(struct vnode *olddp, struct vnode *newdp) { struct filedesc *fdp; struct prison *pr; struct proc *p; int nrele; if (vrefcnt(olddp) == 1) return; nrele = 0; sx_slock(&allproc_lock); FOREACH_PROC_IN_SYSTEM(p) { PROC_LOCK(p); fdp = fdhold(p); PROC_UNLOCK(p); if (fdp == NULL) continue; FILEDESC_XLOCK(fdp); if (fdp->fd_cdir == olddp) { vrefact(newdp); fdp->fd_cdir = newdp; nrele++; } if (fdp->fd_rdir == olddp) { vrefact(newdp); fdp->fd_rdir = newdp; nrele++; } if (fdp->fd_jdir == olddp) { vrefact(newdp); fdp->fd_jdir = newdp; nrele++; } FILEDESC_XUNLOCK(fdp); fddrop(fdp); } sx_sunlock(&allproc_lock); if (rootvnode == olddp) { vrefact(newdp); rootvnode = newdp; nrele++; } mtx_lock(&prison0.pr_mtx); if (prison0.pr_root == olddp) { vrefact(newdp); prison0.pr_root = newdp; nrele++; } mtx_unlock(&prison0.pr_mtx); sx_slock(&allprison_lock); TAILQ_FOREACH(pr, &allprison, pr_list) { mtx_lock(&pr->pr_mtx); if (pr->pr_root == olddp) { vrefact(newdp); pr->pr_root = newdp; nrele++; } mtx_unlock(&pr->pr_mtx); } sx_sunlock(&allprison_lock); while (nrele--) vrele(olddp); } struct filedesc_to_leader * filedesc_to_leader_alloc(struct filedesc_to_leader *old, struct filedesc *fdp, struct proc *leader) { struct filedesc_to_leader *fdtol; fdtol = malloc(sizeof(struct filedesc_to_leader), M_FILEDESC_TO_LEADER, M_WAITOK); fdtol->fdl_refcount = 1; fdtol->fdl_holdcount = 0; fdtol->fdl_wakeup = 0; fdtol->fdl_leader = leader; if (old != NULL) { FILEDESC_XLOCK(fdp); fdtol->fdl_next = old->fdl_next; fdtol->fdl_prev = old; old->fdl_next = fdtol; fdtol->fdl_next->fdl_prev = fdtol; FILEDESC_XUNLOCK(fdp); } else { fdtol->fdl_next = fdtol; fdtol->fdl_prev = fdtol; } return (fdtol); } static int sysctl_kern_proc_nfds(SYSCTL_HANDLER_ARGS) { struct filedesc *fdp; int i, count, slots; if (*(int *)arg1 != 0) return (EINVAL); fdp = curproc->p_fd; count = 0; FILEDESC_SLOCK(fdp); slots = NDSLOTS(fdp->fd_lastfile + 1); for (i = 0; i < slots; i++) count += bitcountl(fdp->fd_map[i]); FILEDESC_SUNLOCK(fdp); return (SYSCTL_OUT(req, &count, sizeof(count))); } static SYSCTL_NODE(_kern_proc, KERN_PROC_NFDS, nfds, CTLFLAG_RD|CTLFLAG_CAPRD|CTLFLAG_MPSAFE, sysctl_kern_proc_nfds, "Number of open file descriptors"); /* * Get file structures globally. */ static int sysctl_kern_file(SYSCTL_HANDLER_ARGS) { struct xfile xf; struct filedesc *fdp; struct file *fp; struct proc *p; int error, n; error = sysctl_wire_old_buffer(req, 0); if (error != 0) return (error); if (req->oldptr == NULL) { n = 0; sx_slock(&allproc_lock); FOREACH_PROC_IN_SYSTEM(p) { PROC_LOCK(p); if (p->p_state == PRS_NEW) { PROC_UNLOCK(p); continue; } fdp = fdhold(p); PROC_UNLOCK(p); if (fdp == NULL) continue; /* overestimates sparse tables. */ if (fdp->fd_lastfile > 0) n += fdp->fd_lastfile; fddrop(fdp); } sx_sunlock(&allproc_lock); return (SYSCTL_OUT(req, 0, n * sizeof(xf))); } error = 0; bzero(&xf, sizeof(xf)); xf.xf_size = sizeof(xf); sx_slock(&allproc_lock); FOREACH_PROC_IN_SYSTEM(p) { PROC_LOCK(p); if (p->p_state == PRS_NEW) { PROC_UNLOCK(p); continue; } if (p_cansee(req->td, p) != 0) { PROC_UNLOCK(p); continue; } xf.xf_pid = p->p_pid; xf.xf_uid = p->p_ucred->cr_uid; fdp = fdhold(p); PROC_UNLOCK(p); if (fdp == NULL) continue; FILEDESC_SLOCK(fdp); for (n = 0; fdp->fd_refcnt > 0 && n <= fdp->fd_lastfile; ++n) { if ((fp = fdp->fd_ofiles[n].fde_file) == NULL) continue; xf.xf_fd = n; xf.xf_file = (uintptr_t)fp; xf.xf_data = (uintptr_t)fp->f_data; xf.xf_vnode = (uintptr_t)fp->f_vnode; xf.xf_type = (uintptr_t)fp->f_type; xf.xf_count = fp->f_count; xf.xf_msgcount = 0; xf.xf_offset = foffset_get(fp); xf.xf_flag = fp->f_flag; error = SYSCTL_OUT(req, &xf, sizeof(xf)); if (error) break; } FILEDESC_SUNLOCK(fdp); fddrop(fdp); if (error) break; } sx_sunlock(&allproc_lock); return (error); } SYSCTL_PROC(_kern, KERN_FILE, file, CTLTYPE_OPAQUE|CTLFLAG_RD|CTLFLAG_MPSAFE, 0, 0, sysctl_kern_file, "S,xfile", "Entire file table"); #ifdef KINFO_FILE_SIZE CTASSERT(sizeof(struct kinfo_file) == KINFO_FILE_SIZE); #endif static int xlate_fflags(int fflags) { static const struct { int fflag; int kf_fflag; } fflags_table[] = { { FAPPEND, KF_FLAG_APPEND }, { FASYNC, KF_FLAG_ASYNC }, { FFSYNC, KF_FLAG_FSYNC }, { FHASLOCK, KF_FLAG_HASLOCK }, { FNONBLOCK, KF_FLAG_NONBLOCK }, { FREAD, KF_FLAG_READ }, { FWRITE, KF_FLAG_WRITE }, { O_CREAT, KF_FLAG_CREAT }, { O_DIRECT, KF_FLAG_DIRECT }, { O_EXCL, KF_FLAG_EXCL }, { O_EXEC, KF_FLAG_EXEC }, { O_EXLOCK, KF_FLAG_EXLOCK }, { O_NOFOLLOW, KF_FLAG_NOFOLLOW }, { O_SHLOCK, KF_FLAG_SHLOCK }, { O_TRUNC, KF_FLAG_TRUNC } }; unsigned int i; int kflags; kflags = 0; for (i = 0; i < nitems(fflags_table); i++) if (fflags & fflags_table[i].fflag) kflags |= fflags_table[i].kf_fflag; return (kflags); } /* Trim unused data from kf_path by truncating the structure size. */ static void pack_kinfo(struct kinfo_file *kif) { kif->kf_structsize = offsetof(struct kinfo_file, kf_path) + strlen(kif->kf_path) + 1; kif->kf_structsize = roundup(kif->kf_structsize, sizeof(uint64_t)); } static void export_file_to_kinfo(struct file *fp, int fd, cap_rights_t *rightsp, struct kinfo_file *kif, struct filedesc *fdp, int flags) { int error; bzero(kif, sizeof(*kif)); /* Set a default type to allow for empty fill_kinfo() methods. */ kif->kf_type = KF_TYPE_UNKNOWN; kif->kf_flags = xlate_fflags(fp->f_flag); if (rightsp != NULL) kif->kf_cap_rights = *rightsp; else cap_rights_init(&kif->kf_cap_rights); kif->kf_fd = fd; kif->kf_ref_count = fp->f_count; kif->kf_offset = foffset_get(fp); /* * This may drop the filedesc lock, so the 'fp' cannot be * accessed after this call. */ error = fo_fill_kinfo(fp, kif, fdp); if (error == 0) kif->kf_status |= KF_ATTR_VALID; if ((flags & KERN_FILEDESC_PACK_KINFO) != 0) pack_kinfo(kif); else kif->kf_structsize = roundup2(sizeof(*kif), sizeof(uint64_t)); } static void export_vnode_to_kinfo(struct vnode *vp, int fd, int fflags, struct kinfo_file *kif, int flags) { int error; bzero(kif, sizeof(*kif)); kif->kf_type = KF_TYPE_VNODE; error = vn_fill_kinfo_vnode(vp, kif); if (error == 0) kif->kf_status |= KF_ATTR_VALID; kif->kf_flags = xlate_fflags(fflags); cap_rights_init(&kif->kf_cap_rights); kif->kf_fd = fd; kif->kf_ref_count = -1; kif->kf_offset = -1; if ((flags & KERN_FILEDESC_PACK_KINFO) != 0) pack_kinfo(kif); else kif->kf_structsize = roundup2(sizeof(*kif), sizeof(uint64_t)); vrele(vp); } struct export_fd_buf { struct filedesc *fdp; struct sbuf *sb; ssize_t remainder; struct kinfo_file kif; int flags; }; static int export_kinfo_to_sb(struct export_fd_buf *efbuf) { struct kinfo_file *kif; kif = &efbuf->kif; if (efbuf->remainder != -1) { if (efbuf->remainder < kif->kf_structsize) { /* Terminate export. */ efbuf->remainder = 0; return (0); } efbuf->remainder -= kif->kf_structsize; } return (sbuf_bcat(efbuf->sb, kif, kif->kf_structsize) == 0 ? 0 : ENOMEM); } static int export_file_to_sb(struct file *fp, int fd, cap_rights_t *rightsp, struct export_fd_buf *efbuf) { int error; if (efbuf->remainder == 0) return (0); export_file_to_kinfo(fp, fd, rightsp, &efbuf->kif, efbuf->fdp, efbuf->flags); FILEDESC_SUNLOCK(efbuf->fdp); error = export_kinfo_to_sb(efbuf); FILEDESC_SLOCK(efbuf->fdp); return (error); } static int export_vnode_to_sb(struct vnode *vp, int fd, int fflags, struct export_fd_buf *efbuf) { int error; if (efbuf->remainder == 0) return (0); if (efbuf->fdp != NULL) FILEDESC_SUNLOCK(efbuf->fdp); export_vnode_to_kinfo(vp, fd, fflags, &efbuf->kif, efbuf->flags); error = export_kinfo_to_sb(efbuf); if (efbuf->fdp != NULL) FILEDESC_SLOCK(efbuf->fdp); return (error); } /* * Store a process file descriptor information to sbuf. * * Takes a locked proc as argument, and returns with the proc unlocked. */ int kern_proc_filedesc_out(struct proc *p, struct sbuf *sb, ssize_t maxlen, int flags) { struct file *fp; struct filedesc *fdp; struct export_fd_buf *efbuf; struct vnode *cttyvp, *textvp, *tracevp; int error, i; cap_rights_t rights; PROC_LOCK_ASSERT(p, MA_OWNED); /* ktrace vnode */ tracevp = p->p_tracevp; if (tracevp != NULL) vrefact(tracevp); /* text vnode */ textvp = p->p_textvp; if (textvp != NULL) vrefact(textvp); /* Controlling tty. */ cttyvp = NULL; if (p->p_pgrp != NULL && p->p_pgrp->pg_session != NULL) { cttyvp = p->p_pgrp->pg_session->s_ttyvp; if (cttyvp != NULL) vrefact(cttyvp); } fdp = fdhold(p); PROC_UNLOCK(p); efbuf = malloc(sizeof(*efbuf), M_TEMP, M_WAITOK); efbuf->fdp = NULL; efbuf->sb = sb; efbuf->remainder = maxlen; efbuf->flags = flags; if (tracevp != NULL) export_vnode_to_sb(tracevp, KF_FD_TYPE_TRACE, FREAD | FWRITE, efbuf); if (textvp != NULL) export_vnode_to_sb(textvp, KF_FD_TYPE_TEXT, FREAD, efbuf); if (cttyvp != NULL) export_vnode_to_sb(cttyvp, KF_FD_TYPE_CTTY, FREAD | FWRITE, efbuf); error = 0; if (fdp == NULL) goto fail; efbuf->fdp = fdp; FILEDESC_SLOCK(fdp); /* working directory */ if (fdp->fd_cdir != NULL) { vrefact(fdp->fd_cdir); export_vnode_to_sb(fdp->fd_cdir, KF_FD_TYPE_CWD, FREAD, efbuf); } /* root directory */ if (fdp->fd_rdir != NULL) { vrefact(fdp->fd_rdir); export_vnode_to_sb(fdp->fd_rdir, KF_FD_TYPE_ROOT, FREAD, efbuf); } /* jail directory */ if (fdp->fd_jdir != NULL) { vrefact(fdp->fd_jdir); export_vnode_to_sb(fdp->fd_jdir, KF_FD_TYPE_JAIL, FREAD, efbuf); } for (i = 0; fdp->fd_refcnt > 0 && i <= fdp->fd_lastfile; i++) { if ((fp = fdp->fd_ofiles[i].fde_file) == NULL) continue; #ifdef CAPABILITIES rights = *cap_rights(fdp, i); #else /* !CAPABILITIES */ rights = cap_no_rights; #endif /* * Create sysctl entry. It is OK to drop the filedesc * lock inside of export_file_to_sb() as we will * re-validate and re-evaluate its properties when the * loop continues. */ error = export_file_to_sb(fp, i, &rights, efbuf); if (error != 0 || efbuf->remainder == 0) break; } FILEDESC_SUNLOCK(fdp); fddrop(fdp); fail: free(efbuf, M_TEMP); return (error); } #define FILEDESC_SBUF_SIZE (sizeof(struct kinfo_file) * 5) /* * Get per-process file descriptors for use by procstat(1), et al. */ static int sysctl_kern_proc_filedesc(SYSCTL_HANDLER_ARGS) { struct sbuf sb; struct proc *p; ssize_t maxlen; int error, error2, *name; name = (int *)arg1; sbuf_new_for_sysctl(&sb, NULL, FILEDESC_SBUF_SIZE, req); sbuf_clear_flags(&sb, SBUF_INCLUDENUL); error = pget((pid_t)name[0], PGET_CANDEBUG | PGET_NOTWEXIT, &p); if (error != 0) { sbuf_delete(&sb); return (error); } maxlen = req->oldptr != NULL ? req->oldlen : -1; error = kern_proc_filedesc_out(p, &sb, maxlen, KERN_FILEDESC_PACK_KINFO); error2 = sbuf_finish(&sb); sbuf_delete(&sb); return (error != 0 ? error : error2); } #ifdef COMPAT_FREEBSD7 #ifdef KINFO_OFILE_SIZE CTASSERT(sizeof(struct kinfo_ofile) == KINFO_OFILE_SIZE); #endif static void kinfo_to_okinfo(struct kinfo_file *kif, struct kinfo_ofile *okif) { okif->kf_structsize = sizeof(*okif); okif->kf_type = kif->kf_type; okif->kf_fd = kif->kf_fd; okif->kf_ref_count = kif->kf_ref_count; okif->kf_flags = kif->kf_flags & (KF_FLAG_READ | KF_FLAG_WRITE | KF_FLAG_APPEND | KF_FLAG_ASYNC | KF_FLAG_FSYNC | KF_FLAG_NONBLOCK | KF_FLAG_DIRECT | KF_FLAG_HASLOCK); okif->kf_offset = kif->kf_offset; if (kif->kf_type == KF_TYPE_VNODE) okif->kf_vnode_type = kif->kf_un.kf_file.kf_file_type; else okif->kf_vnode_type = KF_VTYPE_VNON; strlcpy(okif->kf_path, kif->kf_path, sizeof(okif->kf_path)); if (kif->kf_type == KF_TYPE_SOCKET) { okif->kf_sock_domain = kif->kf_un.kf_sock.kf_sock_domain0; okif->kf_sock_type = kif->kf_un.kf_sock.kf_sock_type0; okif->kf_sock_protocol = kif->kf_un.kf_sock.kf_sock_protocol0; okif->kf_sa_local = kif->kf_un.kf_sock.kf_sa_local; okif->kf_sa_peer = kif->kf_un.kf_sock.kf_sa_peer; } else { okif->kf_sa_local.ss_family = AF_UNSPEC; okif->kf_sa_peer.ss_family = AF_UNSPEC; } } static int export_vnode_for_osysctl(struct vnode *vp, int type, struct kinfo_file *kif, struct kinfo_ofile *okif, struct filedesc *fdp, struct sysctl_req *req) { int error; vrefact(vp); FILEDESC_SUNLOCK(fdp); export_vnode_to_kinfo(vp, type, 0, kif, KERN_FILEDESC_PACK_KINFO); kinfo_to_okinfo(kif, okif); error = SYSCTL_OUT(req, okif, sizeof(*okif)); FILEDESC_SLOCK(fdp); return (error); } /* * Get per-process file descriptors for use by procstat(1), et al. */ static int sysctl_kern_proc_ofiledesc(SYSCTL_HANDLER_ARGS) { struct kinfo_ofile *okif; struct kinfo_file *kif; struct filedesc *fdp; int error, i, *name; struct file *fp; struct proc *p; name = (int *)arg1; error = pget((pid_t)name[0], PGET_CANDEBUG | PGET_NOTWEXIT, &p); if (error != 0) return (error); fdp = fdhold(p); PROC_UNLOCK(p); if (fdp == NULL) return (ENOENT); kif = malloc(sizeof(*kif), M_TEMP, M_WAITOK); okif = malloc(sizeof(*okif), M_TEMP, M_WAITOK); FILEDESC_SLOCK(fdp); if (fdp->fd_cdir != NULL) export_vnode_for_osysctl(fdp->fd_cdir, KF_FD_TYPE_CWD, kif, okif, fdp, req); if (fdp->fd_rdir != NULL) export_vnode_for_osysctl(fdp->fd_rdir, KF_FD_TYPE_ROOT, kif, okif, fdp, req); if (fdp->fd_jdir != NULL) export_vnode_for_osysctl(fdp->fd_jdir, KF_FD_TYPE_JAIL, kif, okif, fdp, req); for (i = 0; fdp->fd_refcnt > 0 && i <= fdp->fd_lastfile; i++) { if ((fp = fdp->fd_ofiles[i].fde_file) == NULL) continue; export_file_to_kinfo(fp, i, NULL, kif, fdp, KERN_FILEDESC_PACK_KINFO); FILEDESC_SUNLOCK(fdp); kinfo_to_okinfo(kif, okif); error = SYSCTL_OUT(req, okif, sizeof(*okif)); FILEDESC_SLOCK(fdp); if (error) break; } FILEDESC_SUNLOCK(fdp); fddrop(fdp); free(kif, M_TEMP); free(okif, M_TEMP); return (0); } static SYSCTL_NODE(_kern_proc, KERN_PROC_OFILEDESC, ofiledesc, CTLFLAG_RD|CTLFLAG_MPSAFE, sysctl_kern_proc_ofiledesc, "Process ofiledesc entries"); #endif /* COMPAT_FREEBSD7 */ int vntype_to_kinfo(int vtype) { struct { int vtype; int kf_vtype; } vtypes_table[] = { { VBAD, KF_VTYPE_VBAD }, { VBLK, KF_VTYPE_VBLK }, { VCHR, KF_VTYPE_VCHR }, { VDIR, KF_VTYPE_VDIR }, { VFIFO, KF_VTYPE_VFIFO }, { VLNK, KF_VTYPE_VLNK }, { VNON, KF_VTYPE_VNON }, { VREG, KF_VTYPE_VREG }, { VSOCK, KF_VTYPE_VSOCK } }; unsigned int i; /* * Perform vtype translation. */ for (i = 0; i < nitems(vtypes_table); i++) if (vtypes_table[i].vtype == vtype) return (vtypes_table[i].kf_vtype); return (KF_VTYPE_UNKNOWN); } static SYSCTL_NODE(_kern_proc, KERN_PROC_FILEDESC, filedesc, CTLFLAG_RD|CTLFLAG_MPSAFE, sysctl_kern_proc_filedesc, "Process filedesc entries"); /* * Store a process current working directory information to sbuf. * * Takes a locked proc as argument, and returns with the proc unlocked. */ int kern_proc_cwd_out(struct proc *p, struct sbuf *sb, ssize_t maxlen) { struct filedesc *fdp; struct export_fd_buf *efbuf; int error; PROC_LOCK_ASSERT(p, MA_OWNED); fdp = fdhold(p); PROC_UNLOCK(p); if (fdp == NULL) return (EINVAL); efbuf = malloc(sizeof(*efbuf), M_TEMP, M_WAITOK); efbuf->fdp = fdp; efbuf->sb = sb; efbuf->remainder = maxlen; FILEDESC_SLOCK(fdp); if (fdp->fd_cdir == NULL) error = EINVAL; else { vrefact(fdp->fd_cdir); error = export_vnode_to_sb(fdp->fd_cdir, KF_FD_TYPE_CWD, FREAD, efbuf); } FILEDESC_SUNLOCK(fdp); fddrop(fdp); free(efbuf, M_TEMP); return (error); } /* * Get per-process current working directory. */ static int sysctl_kern_proc_cwd(SYSCTL_HANDLER_ARGS) { struct sbuf sb; struct proc *p; ssize_t maxlen; int error, error2, *name; name = (int *)arg1; sbuf_new_for_sysctl(&sb, NULL, sizeof(struct kinfo_file), req); sbuf_clear_flags(&sb, SBUF_INCLUDENUL); error = pget((pid_t)name[0], PGET_CANDEBUG | PGET_NOTWEXIT, &p); if (error != 0) { sbuf_delete(&sb); return (error); } maxlen = req->oldptr != NULL ? req->oldlen : -1; error = kern_proc_cwd_out(p, &sb, maxlen); error2 = sbuf_finish(&sb); sbuf_delete(&sb); return (error != 0 ? error : error2); } static SYSCTL_NODE(_kern_proc, KERN_PROC_CWD, cwd, CTLFLAG_RD|CTLFLAG_MPSAFE, sysctl_kern_proc_cwd, "Process current working directory"); #ifdef DDB /* * For the purposes of debugging, generate a human-readable string for the * file type. */ static const char * file_type_to_name(short type) { switch (type) { case 0: return ("zero"); case DTYPE_VNODE: return ("vnode"); case DTYPE_SOCKET: return ("socket"); case DTYPE_PIPE: return ("pipe"); case DTYPE_FIFO: return ("fifo"); case DTYPE_KQUEUE: return ("kqueue"); case DTYPE_CRYPTO: return ("crypto"); case DTYPE_MQUEUE: return ("mqueue"); case DTYPE_SHM: return ("shm"); case DTYPE_SEM: return ("ksem"); case DTYPE_PTS: return ("pts"); case DTYPE_DEV: return ("dev"); case DTYPE_PROCDESC: return ("proc"); case DTYPE_LINUXEFD: return ("levent"); case DTYPE_LINUXTFD: return ("ltimer"); default: return ("unkn"); } } /* * For the purposes of debugging, identify a process (if any, perhaps one of * many) that references the passed file in its file descriptor array. Return * NULL if none. */ static struct proc * file_to_first_proc(struct file *fp) { struct filedesc *fdp; struct proc *p; int n; FOREACH_PROC_IN_SYSTEM(p) { if (p->p_state == PRS_NEW) continue; fdp = p->p_fd; if (fdp == NULL) continue; for (n = 0; n <= fdp->fd_lastfile; n++) { if (fp == fdp->fd_ofiles[n].fde_file) return (p); } } return (NULL); } static void db_print_file(struct file *fp, int header) { #define XPTRWIDTH ((int)howmany(sizeof(void *) * NBBY, 4)) struct proc *p; if (header) db_printf("%*s %6s %*s %8s %4s %5s %6s %*s %5s %s\n", XPTRWIDTH, "File", "Type", XPTRWIDTH, "Data", "Flag", "GCFl", "Count", "MCount", XPTRWIDTH, "Vnode", "FPID", "FCmd"); p = file_to_first_proc(fp); db_printf("%*p %6s %*p %08x %04x %5d %6d %*p %5d %s\n", XPTRWIDTH, fp, file_type_to_name(fp->f_type), XPTRWIDTH, fp->f_data, fp->f_flag, 0, fp->f_count, 0, XPTRWIDTH, fp->f_vnode, p != NULL ? p->p_pid : -1, p != NULL ? p->p_comm : "-"); #undef XPTRWIDTH } DB_SHOW_COMMAND(file, db_show_file) { struct file *fp; if (!have_addr) { db_printf("usage: show file \n"); return; } fp = (struct file *)addr; db_print_file(fp, 1); } DB_SHOW_COMMAND(files, db_show_files) { struct filedesc *fdp; struct file *fp; struct proc *p; int header; int n; header = 1; FOREACH_PROC_IN_SYSTEM(p) { if (p->p_state == PRS_NEW) continue; if ((fdp = p->p_fd) == NULL) continue; for (n = 0; n <= fdp->fd_lastfile; ++n) { if ((fp = fdp->fd_ofiles[n].fde_file) == NULL) continue; db_print_file(fp, header); header = 0; } } } #endif SYSCTL_INT(_kern, KERN_MAXFILESPERPROC, maxfilesperproc, CTLFLAG_RW, &maxfilesperproc, 0, "Maximum files allowed open per process"); SYSCTL_INT(_kern, KERN_MAXFILES, maxfiles, CTLFLAG_RW, &maxfiles, 0, "Maximum number of files"); SYSCTL_INT(_kern, OID_AUTO, openfiles, CTLFLAG_RD, __DEVOLATILE(int *, &openfiles), 0, "System-wide number of open files"); /* ARGSUSED*/ static void filelistinit(void *dummy) { file_zone = uma_zcreate("Files", sizeof(struct file), NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE); filedesc0_zone = uma_zcreate("filedesc0", sizeof(struct filedesc0), NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0); mtx_init(&sigio_lock, "sigio lock", NULL, MTX_DEF); } SYSINIT(select, SI_SUB_LOCK, SI_ORDER_FIRST, filelistinit, NULL); /*-------------------------------------------------------------------*/ static int badfo_readwrite(struct file *fp, struct uio *uio, struct ucred *active_cred, int flags, struct thread *td) { return (EBADF); } static int badfo_truncate(struct file *fp, off_t length, struct ucred *active_cred, struct thread *td) { return (EINVAL); } static int badfo_ioctl(struct file *fp, u_long com, void *data, struct ucred *active_cred, struct thread *td) { return (EBADF); } static int badfo_poll(struct file *fp, int events, struct ucred *active_cred, struct thread *td) { return (0); } static int badfo_kqfilter(struct file *fp, struct knote *kn) { return (EBADF); } static int badfo_stat(struct file *fp, struct stat *sb, struct ucred *active_cred, struct thread *td) { return (EBADF); } static int badfo_close(struct file *fp, struct thread *td) { return (0); } static int badfo_chmod(struct file *fp, mode_t mode, struct ucred *active_cred, struct thread *td) { return (EBADF); } static int badfo_chown(struct file *fp, uid_t uid, gid_t gid, struct ucred *active_cred, struct thread *td) { return (EBADF); } static int badfo_sendfile(struct file *fp, int sockfd, struct uio *hdr_uio, struct uio *trl_uio, off_t offset, size_t nbytes, off_t *sent, int flags, struct thread *td) { return (EBADF); } static int badfo_fill_kinfo(struct file *fp, struct kinfo_file *kif, struct filedesc *fdp) { return (0); } struct fileops badfileops = { .fo_read = badfo_readwrite, .fo_write = badfo_readwrite, .fo_truncate = badfo_truncate, .fo_ioctl = badfo_ioctl, .fo_poll = badfo_poll, .fo_kqfilter = badfo_kqfilter, .fo_stat = badfo_stat, .fo_close = badfo_close, .fo_chmod = badfo_chmod, .fo_chown = badfo_chown, .fo_sendfile = badfo_sendfile, .fo_fill_kinfo = badfo_fill_kinfo, }; int invfo_rdwr(struct file *fp, struct uio *uio, struct ucred *active_cred, int flags, struct thread *td) { return (EOPNOTSUPP); } int invfo_truncate(struct file *fp, off_t length, struct ucred *active_cred, struct thread *td) { return (EINVAL); } int invfo_ioctl(struct file *fp, u_long com, void *data, struct ucred *active_cred, struct thread *td) { return (ENOTTY); } int invfo_poll(struct file *fp, int events, struct ucred *active_cred, struct thread *td) { return (poll_no_poll(events)); } int invfo_kqfilter(struct file *fp, struct knote *kn) { return (EINVAL); } int invfo_chmod(struct file *fp, mode_t mode, struct ucred *active_cred, struct thread *td) { return (EINVAL); } int invfo_chown(struct file *fp, uid_t uid, gid_t gid, struct ucred *active_cred, struct thread *td) { return (EINVAL); } int invfo_sendfile(struct file *fp, int sockfd, struct uio *hdr_uio, struct uio *trl_uio, off_t offset, size_t nbytes, off_t *sent, int flags, struct thread *td) { return (EINVAL); } /*-------------------------------------------------------------------*/ /* * File Descriptor pseudo-device driver (/dev/fd/). * * Opening minor device N dup()s the file (if any) connected to file * descriptor N belonging to the calling process. Note that this driver * consists of only the ``open()'' routine, because all subsequent * references to this file will be direct to the other driver. * * XXX: we could give this one a cloning event handler if necessary. */ /* ARGSUSED */ static int fdopen(struct cdev *dev, int mode, int type, struct thread *td) { /* * XXX Kludge: set curthread->td_dupfd to contain the value of the * the file descriptor being sought for duplication. The error * return ensures that the vnode for this device will be released * by vn_open. Open will detect this special error and take the * actions in dupfdopen below. Other callers of vn_open or VOP_OPEN * will simply report the error. */ td->td_dupfd = dev2unit(dev); return (ENODEV); } static struct cdevsw fildesc_cdevsw = { .d_version = D_VERSION, .d_open = fdopen, .d_name = "FD", }; static void fildesc_drvinit(void *unused) { struct cdev *dev; dev = make_dev_credf(MAKEDEV_ETERNAL, &fildesc_cdevsw, 0, NULL, UID_ROOT, GID_WHEEL, 0666, "fd/0"); make_dev_alias(dev, "stdin"); dev = make_dev_credf(MAKEDEV_ETERNAL, &fildesc_cdevsw, 1, NULL, UID_ROOT, GID_WHEEL, 0666, "fd/1"); make_dev_alias(dev, "stdout"); dev = make_dev_credf(MAKEDEV_ETERNAL, &fildesc_cdevsw, 2, NULL, UID_ROOT, GID_WHEEL, 0666, "fd/2"); make_dev_alias(dev, "stderr"); } SYSINIT(fildescdev, SI_SUB_DRIVERS, SI_ORDER_MIDDLE, fildesc_drvinit, NULL); Index: head/sys/kern/vfs_lookup.c =================================================================== --- head/sys/kern/vfs_lookup.c (revision 342057) +++ head/sys/kern/vfs_lookup.c (revision 342058) @@ -1,1478 +1,1478 @@ /*- * SPDX-License-Identifier: BSD-3-Clause * * 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_lookup.c 8.4 (Berkeley) 2/16/94 */ #include __FBSDID("$FreeBSD$"); #include "opt_capsicum.h" #include "opt_ktrace.h" #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #ifdef KTRACE #include #endif #include #include #include #define NAMEI_DIAGNOSTIC 1 #undef NAMEI_DIAGNOSTIC SDT_PROVIDER_DECLARE(vfs); SDT_PROBE_DEFINE3(vfs, namei, lookup, entry, "struct vnode *", "char *", "unsigned long"); SDT_PROBE_DEFINE2(vfs, namei, lookup, return, "int", "struct vnode *"); /* Allocation zone for namei. */ uma_zone_t namei_zone; /* Placeholder vnode for mp traversal. */ static struct vnode *vp_crossmp; static int crossmp_vop_islocked(struct vop_islocked_args *ap) { return (LK_SHARED); } static int crossmp_vop_lock1(struct vop_lock1_args *ap) { struct vnode *vp; struct lock *lk __unused; const char *file __unused; int flags, line __unused; vp = ap->a_vp; lk = vp->v_vnlock; flags = ap->a_flags; file = ap->a_file; line = ap->a_line; if ((flags & LK_SHARED) == 0) panic("invalid lock request for crossmp"); WITNESS_CHECKORDER(&lk->lock_object, LOP_NEWORDER, file, line, flags & LK_INTERLOCK ? &VI_MTX(vp)->lock_object : NULL); WITNESS_LOCK(&lk->lock_object, 0, file, line); if ((flags & LK_INTERLOCK) != 0) VI_UNLOCK(vp); LOCK_LOG_LOCK("SLOCK", &lk->lock_object, 0, 0, ap->a_file, line); return (0); } static int crossmp_vop_unlock(struct vop_unlock_args *ap) { struct vnode *vp; struct lock *lk __unused; int flags; vp = ap->a_vp; lk = vp->v_vnlock; flags = ap->a_flags; if ((flags & LK_INTERLOCK) != 0) VI_UNLOCK(vp); WITNESS_UNLOCK(&lk->lock_object, 0, LOCK_FILE, LOCK_LINE); LOCK_LOG_LOCK("SUNLOCK", &lk->lock_object, 0, 0, LOCK_FILE, LOCK_LINE); return (0); } static struct vop_vector crossmp_vnodeops = { .vop_default = &default_vnodeops, .vop_islocked = crossmp_vop_islocked, .vop_lock1 = crossmp_vop_lock1, .vop_unlock = crossmp_vop_unlock, }; struct nameicap_tracker { struct vnode *dp; TAILQ_ENTRY(nameicap_tracker) nm_link; }; /* Zone for cap mode tracker elements used for dotdot capability checks. */ static uma_zone_t nt_zone; static void nameiinit(void *dummy __unused) { namei_zone = uma_zcreate("NAMEI", MAXPATHLEN, NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0); nt_zone = uma_zcreate("rentr", sizeof(struct nameicap_tracker), NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0); getnewvnode("crossmp", NULL, &crossmp_vnodeops, &vp_crossmp); } SYSINIT(vfs, SI_SUB_VFS, SI_ORDER_SECOND, nameiinit, NULL); static int lookup_cap_dotdot = 1; SYSCTL_INT(_vfs, OID_AUTO, lookup_cap_dotdot, CTLFLAG_RWTUN, &lookup_cap_dotdot, 0, "enables \"..\" components in path lookup in capability mode"); static int lookup_cap_dotdot_nonlocal = 1; SYSCTL_INT(_vfs, OID_AUTO, lookup_cap_dotdot_nonlocal, CTLFLAG_RWTUN, &lookup_cap_dotdot_nonlocal, 0, "enables \"..\" components in path lookup in capability mode " "on non-local mount"); static void nameicap_tracker_add(struct nameidata *ndp, struct vnode *dp) { struct nameicap_tracker *nt; if ((ndp->ni_lcf & NI_LCF_CAP_DOTDOT) == 0 || dp->v_type != VDIR) return; if ((ndp->ni_lcf & (NI_LCF_BENEATH_ABS | NI_LCF_BENEATH_LATCHED)) == NI_LCF_BENEATH_ABS) { MPASS((ndp->ni_lcf & NI_LCF_LATCH) != 0); if (dp != ndp->ni_beneath_latch) return; ndp->ni_lcf |= NI_LCF_BENEATH_LATCHED; } nt = uma_zalloc(nt_zone, M_WAITOK); vhold(dp); nt->dp = dp; TAILQ_INSERT_TAIL(&ndp->ni_cap_tracker, nt, nm_link); } static void nameicap_cleanup(struct nameidata *ndp, bool clean_latch) { struct nameicap_tracker *nt, *nt1; KASSERT(TAILQ_EMPTY(&ndp->ni_cap_tracker) || (ndp->ni_lcf & NI_LCF_CAP_DOTDOT) != 0, ("not strictrelative")); TAILQ_FOREACH_SAFE(nt, &ndp->ni_cap_tracker, nm_link, nt1) { TAILQ_REMOVE(&ndp->ni_cap_tracker, nt, nm_link); vdrop(nt->dp); uma_zfree(nt_zone, nt); } if (clean_latch && (ndp->ni_lcf & NI_LCF_LATCH) != 0) { ndp->ni_lcf &= ~NI_LCF_LATCH; vrele(ndp->ni_beneath_latch); } } /* * For dotdot lookups in capability mode, only allow the component * lookup to succeed if the resulting directory was already traversed * during the operation. Also fail dotdot lookups for non-local * filesystems, where external agents might assist local lookups to * escape the compartment. */ static int nameicap_check_dotdot(struct nameidata *ndp, struct vnode *dp) { struct nameicap_tracker *nt; struct mount *mp; if ((ndp->ni_lcf & NI_LCF_CAP_DOTDOT) == 0 || dp == NULL || dp->v_type != VDIR) return (0); mp = dp->v_mount; if (lookup_cap_dotdot_nonlocal == 0 && mp != NULL && (mp->mnt_flag & MNT_LOCAL) == 0) return (ENOTCAPABLE); TAILQ_FOREACH_REVERSE(nt, &ndp->ni_cap_tracker, nameicap_tracker_head, nm_link) { if (dp == nt->dp) return (0); } if ((ndp->ni_lcf & NI_LCF_BENEATH_ABS) != 0) { ndp->ni_lcf &= ~NI_LCF_BENEATH_LATCHED; nameicap_cleanup(ndp, false); return (0); } return (ENOTCAPABLE); } static void namei_cleanup_cnp(struct componentname *cnp) { uma_zfree(namei_zone, cnp->cn_pnbuf); #ifdef DIAGNOSTIC cnp->cn_pnbuf = NULL; cnp->cn_nameptr = NULL; #endif } static int namei_handle_root(struct nameidata *ndp, struct vnode **dpp) { struct componentname *cnp; cnp = &ndp->ni_cnd; if ((ndp->ni_lcf & NI_LCF_STRICTRELATIVE) != 0) { #ifdef KTRACE if (KTRPOINT(curthread, KTR_CAPFAIL)) ktrcapfail(CAPFAIL_LOOKUP, NULL, NULL); #endif return (ENOTCAPABLE); } if ((cnp->cn_flags & BENEATH) != 0) { ndp->ni_lcf |= NI_LCF_BENEATH_ABS; ndp->ni_lcf &= ~NI_LCF_BENEATH_LATCHED; nameicap_cleanup(ndp, false); } while (*(cnp->cn_nameptr) == '/') { cnp->cn_nameptr++; ndp->ni_pathlen--; } *dpp = ndp->ni_rootdir; vrefact(*dpp); return (0); } /* * Convert a pathname into a pointer to a locked vnode. * * The FOLLOW flag is set when symbolic links are to be followed * when they occur at the end of the name translation process. * Symbolic links are always followed for all other pathname * components other than the last. * * The segflg defines whether the name is to be copied from user * space or kernel space. * * Overall outline of namei: * * copy in name * get starting directory * while (!done && !error) { * call lookup to search path. * if symbolic link, massage name in buffer and continue * } */ int namei(struct nameidata *ndp) { struct filedesc *fdp; /* pointer to file descriptor state */ char *cp; /* pointer into pathname argument */ struct vnode *dp; /* the directory we are searching */ struct iovec aiov; /* uio for reading symbolic links */ struct componentname *cnp; struct thread *td; struct proc *p; cap_rights_t rights; struct filecaps dirfd_caps; struct uio auio; int error, linklen, startdir_used; cnp = &ndp->ni_cnd; td = cnp->cn_thread; p = td->td_proc; ndp->ni_cnd.cn_cred = ndp->ni_cnd.cn_thread->td_ucred; KASSERT(cnp->cn_cred && p, ("namei: bad cred/proc")); KASSERT((cnp->cn_nameiop & (~OPMASK)) == 0, ("namei: nameiop contaminated with flags")); KASSERT((cnp->cn_flags & OPMASK) == 0, ("namei: flags contaminated with nameiops")); MPASS(ndp->ni_startdir == NULL || ndp->ni_startdir->v_type == VDIR || ndp->ni_startdir->v_type == VBAD); fdp = p->p_fd; TAILQ_INIT(&ndp->ni_cap_tracker); ndp->ni_lcf = 0; /* We will set this ourselves if we need it. */ cnp->cn_flags &= ~TRAILINGSLASH; /* * Get a buffer for the name to be translated, and copy the * name into the buffer. */ if ((cnp->cn_flags & HASBUF) == 0) cnp->cn_pnbuf = uma_zalloc(namei_zone, M_WAITOK); if (ndp->ni_segflg == UIO_SYSSPACE) error = copystr(ndp->ni_dirp, cnp->cn_pnbuf, MAXPATHLEN, &ndp->ni_pathlen); else error = copyinstr(ndp->ni_dirp, cnp->cn_pnbuf, MAXPATHLEN, &ndp->ni_pathlen); /* * Don't allow empty pathnames. */ if (error == 0 && *cnp->cn_pnbuf == '\0') error = ENOENT; #ifdef CAPABILITY_MODE /* * In capability mode, lookups must be restricted to happen in * the subtree with the root specified by the file descriptor: * - The root must be real file descriptor, not the pseudo-descriptor * AT_FDCWD. * - The passed path must be relative and not absolute. * - If lookup_cap_dotdot is disabled, path must not contain the * '..' components. * - If lookup_cap_dotdot is enabled, we verify that all '..' * components lookups result in the directories which were * previously walked by us, which prevents an escape from * the relative root. */ if (error == 0 && IN_CAPABILITY_MODE(td) && (cnp->cn_flags & NOCAPCHECK) == 0) { ndp->ni_lcf |= NI_LCF_STRICTRELATIVE; if (ndp->ni_dirfd == AT_FDCWD) { #ifdef KTRACE if (KTRPOINT(td, KTR_CAPFAIL)) ktrcapfail(CAPFAIL_LOOKUP, NULL, NULL); #endif error = ECAPMODE; } } #endif if (error != 0) { namei_cleanup_cnp(cnp); ndp->ni_vp = NULL; return (error); } ndp->ni_loopcnt = 0; #ifdef KTRACE if (KTRPOINT(td, KTR_NAMEI)) { KASSERT(cnp->cn_thread == curthread, ("namei not using curthread")); ktrnamei(cnp->cn_pnbuf); } #endif /* * Get starting point for the translation. */ FILEDESC_SLOCK(fdp); ndp->ni_rootdir = fdp->fd_rdir; vrefact(ndp->ni_rootdir); ndp->ni_topdir = fdp->fd_jdir; /* * If we are auditing the kernel pathname, save the user pathname. */ if (cnp->cn_flags & AUDITVNODE1) AUDIT_ARG_UPATH1(td, ndp->ni_dirfd, cnp->cn_pnbuf); if (cnp->cn_flags & AUDITVNODE2) AUDIT_ARG_UPATH2(td, ndp->ni_dirfd, cnp->cn_pnbuf); startdir_used = 0; dp = NULL; cnp->cn_nameptr = cnp->cn_pnbuf; if (cnp->cn_pnbuf[0] == '/') { error = namei_handle_root(ndp, &dp); } else { if (ndp->ni_startdir != NULL) { dp = ndp->ni_startdir; startdir_used = 1; } else if (ndp->ni_dirfd == AT_FDCWD) { dp = fdp->fd_cdir; vrefact(dp); } else { rights = ndp->ni_rightsneeded; cap_rights_set(&rights, CAP_LOOKUP); if (cnp->cn_flags & AUDITVNODE1) AUDIT_ARG_ATFD1(ndp->ni_dirfd); if (cnp->cn_flags & AUDITVNODE2) AUDIT_ARG_ATFD2(ndp->ni_dirfd); error = fgetvp_rights(td, ndp->ni_dirfd, &rights, &ndp->ni_filecaps, &dp); if (error == EINVAL) error = ENOTDIR; #ifdef CAPABILITIES /* * If file descriptor doesn't have all rights, * all lookups relative to it must also be * strictly relative. */ CAP_ALL(&rights); if (!cap_rights_contains(&ndp->ni_filecaps.fc_rights, &rights) || ndp->ni_filecaps.fc_fcntls != CAP_FCNTL_ALL || ndp->ni_filecaps.fc_nioctls != -1) { ndp->ni_lcf |= NI_LCF_STRICTRELATIVE; } #endif } if (error == 0 && dp->v_type != VDIR) error = ENOTDIR; } if (error == 0 && (cnp->cn_flags & BENEATH) != 0) { if (ndp->ni_dirfd == AT_FDCWD) { ndp->ni_beneath_latch = fdp->fd_cdir; vrefact(ndp->ni_beneath_latch); } else { rights = ndp->ni_rightsneeded; cap_rights_set(&rights, CAP_LOOKUP); error = fgetvp_rights(td, ndp->ni_dirfd, &rights, &dirfd_caps, &ndp->ni_beneath_latch); if (error == 0 && dp->v_type != VDIR) { vrele(ndp->ni_beneath_latch); error = ENOTDIR; } } if (error == 0) ndp->ni_lcf |= NI_LCF_LATCH; } FILEDESC_SUNLOCK(fdp); if (ndp->ni_startdir != NULL && !startdir_used) vrele(ndp->ni_startdir); if (error != 0) { if (dp != NULL) vrele(dp); goto out; } MPASS((ndp->ni_lcf & (NI_LCF_BENEATH_ABS | NI_LCF_LATCH)) != NI_LCF_BENEATH_ABS); if (((ndp->ni_lcf & NI_LCF_STRICTRELATIVE) != 0 && lookup_cap_dotdot != 0) || ((ndp->ni_lcf & NI_LCF_STRICTRELATIVE) == 0 && (cnp->cn_flags & BENEATH) != 0)) ndp->ni_lcf |= NI_LCF_CAP_DOTDOT; SDT_PROBE3(vfs, namei, lookup, entry, dp, cnp->cn_pnbuf, cnp->cn_flags); for (;;) { ndp->ni_startdir = dp; error = lookup(ndp); if (error != 0) goto out; /* * If not a symbolic link, we're done. */ if ((cnp->cn_flags & ISSYMLINK) == 0) { vrele(ndp->ni_rootdir); if ((cnp->cn_flags & (SAVENAME | SAVESTART)) == 0) { namei_cleanup_cnp(cnp); } else cnp->cn_flags |= HASBUF; if ((ndp->ni_lcf & (NI_LCF_BENEATH_ABS | NI_LCF_BENEATH_LATCHED)) == NI_LCF_BENEATH_ABS) { NDFREE(ndp, 0); error = ENOTCAPABLE; } nameicap_cleanup(ndp, true); SDT_PROBE2(vfs, namei, lookup, return, error, (error == 0 ? ndp->ni_vp : NULL)); return (error); } if (ndp->ni_loopcnt++ >= MAXSYMLINKS) { error = ELOOP; break; } #ifdef MAC if ((cnp->cn_flags & NOMACCHECK) == 0) { error = mac_vnode_check_readlink(td->td_ucred, ndp->ni_vp); if (error != 0) break; } #endif if (ndp->ni_pathlen > 1) cp = uma_zalloc(namei_zone, M_WAITOK); else cp = cnp->cn_pnbuf; aiov.iov_base = cp; aiov.iov_len = MAXPATHLEN; auio.uio_iov = &aiov; auio.uio_iovcnt = 1; auio.uio_offset = 0; auio.uio_rw = UIO_READ; auio.uio_segflg = UIO_SYSSPACE; auio.uio_td = td; auio.uio_resid = MAXPATHLEN; error = VOP_READLINK(ndp->ni_vp, &auio, cnp->cn_cred); if (error != 0) { if (ndp->ni_pathlen > 1) uma_zfree(namei_zone, cp); break; } linklen = MAXPATHLEN - auio.uio_resid; if (linklen == 0) { if (ndp->ni_pathlen > 1) uma_zfree(namei_zone, cp); error = ENOENT; break; } if (linklen + ndp->ni_pathlen > MAXPATHLEN) { if (ndp->ni_pathlen > 1) uma_zfree(namei_zone, cp); error = ENAMETOOLONG; break; } if (ndp->ni_pathlen > 1) { bcopy(ndp->ni_next, cp + linklen, ndp->ni_pathlen); uma_zfree(namei_zone, cnp->cn_pnbuf); cnp->cn_pnbuf = cp; } else cnp->cn_pnbuf[linklen] = '\0'; ndp->ni_pathlen += linklen; vput(ndp->ni_vp); dp = ndp->ni_dvp; /* * Check if root directory should replace current directory. */ cnp->cn_nameptr = cnp->cn_pnbuf; if (*(cnp->cn_nameptr) == '/') { vrele(dp); error = namei_handle_root(ndp, &dp); if (error != 0) goto out; } } vput(ndp->ni_vp); ndp->ni_vp = NULL; vrele(ndp->ni_dvp); out: vrele(ndp->ni_rootdir); MPASS(error != 0); namei_cleanup_cnp(cnp); nameicap_cleanup(ndp, true); SDT_PROBE2(vfs, namei, lookup, return, error, NULL); return (error); } static int compute_cn_lkflags(struct mount *mp, int lkflags, int cnflags) { if (mp == NULL || ((lkflags & LK_SHARED) && (!(mp->mnt_kern_flag & MNTK_LOOKUP_SHARED) || ((cnflags & ISDOTDOT) && (mp->mnt_kern_flag & MNTK_LOOKUP_EXCL_DOTDOT))))) { lkflags &= ~LK_SHARED; lkflags |= LK_EXCLUSIVE; } lkflags |= LK_NODDLKTREAT; return (lkflags); } static __inline int needs_exclusive_leaf(struct mount *mp, int flags) { /* * Intermediate nodes can use shared locks, we only need to * force an exclusive lock for leaf nodes. */ if ((flags & (ISLASTCN | LOCKLEAF)) != (ISLASTCN | LOCKLEAF)) return (0); /* Always use exclusive locks if LOCKSHARED isn't set. */ if (!(flags & LOCKSHARED)) return (1); /* * For lookups during open(), if the mount point supports * extended shared operations, then use a shared lock for the * leaf node, otherwise use an exclusive lock. */ if ((flags & ISOPEN) != 0) return (!MNT_EXTENDED_SHARED(mp)); /* * Lookup requests outside of open() that specify LOCKSHARED * only need a shared lock on the leaf vnode. */ return (0); } /* * Search a pathname. * This is a very central and rather complicated routine. * * The pathname is pointed to by ni_ptr and is of length ni_pathlen. * The starting directory is taken from ni_startdir. The pathname is * descended until done, or a symbolic link is encountered. The variable * ni_more is clear if the path is completed; it is set to one if a * symbolic link needing interpretation is encountered. * * The flag argument is LOOKUP, CREATE, RENAME, or DELETE depending on * whether the name is to be looked up, created, renamed, or deleted. * When CREATE, RENAME, or DELETE is specified, information usable in * creating, renaming, or deleting a directory entry may be calculated. * If flag has LOCKPARENT or'ed into it, the parent directory is returned * locked. If flag has WANTPARENT or'ed into it, the parent directory is * returned unlocked. Otherwise the parent directory is not returned. If * the target of the pathname exists and LOCKLEAF is or'ed into the flag * the target is returned locked, otherwise it is returned unlocked. * When creating or renaming and LOCKPARENT is specified, the target may not * be ".". When deleting and LOCKPARENT is specified, the target may be ".". * * Overall outline of lookup: * * dirloop: * identify next component of name at ndp->ni_ptr * handle degenerate case where name is null string * if .. and crossing mount points and on mounted filesys, find parent * call VOP_LOOKUP routine for next component name * directory vnode returned in ni_dvp, unlocked unless LOCKPARENT set * component vnode returned in ni_vp (if it exists), locked. * if result vnode is mounted on and crossing mount points, * find mounted on vnode * if more components of name, do next level at dirloop * return the answer in ni_vp, locked if LOCKLEAF set * if LOCKPARENT set, return locked parent in ni_dvp * if WANTPARENT set, return unlocked parent in ni_dvp */ int lookup(struct nameidata *ndp) { char *cp; /* pointer into pathname argument */ char *prev_ni_next; /* saved ndp->ni_next */ struct vnode *dp = NULL; /* the directory we are searching */ struct vnode *tdp; /* saved dp */ struct mount *mp; /* mount table entry */ struct prison *pr; size_t prev_ni_pathlen; /* saved ndp->ni_pathlen */ int docache; /* == 0 do not cache last component */ int wantparent; /* 1 => wantparent or lockparent flag */ int rdonly; /* lookup read-only flag bit */ int error = 0; int dpunlocked = 0; /* dp has already been unlocked */ int relookup = 0; /* do not consume the path component */ struct componentname *cnp = &ndp->ni_cnd; int lkflags_save; int ni_dvp_unlocked; /* * Setup: break out flag bits into variables. */ ni_dvp_unlocked = 0; wantparent = cnp->cn_flags & (LOCKPARENT | WANTPARENT); KASSERT(cnp->cn_nameiop == LOOKUP || wantparent, ("CREATE, DELETE, RENAME require LOCKPARENT or WANTPARENT.")); docache = (cnp->cn_flags & NOCACHE) ^ NOCACHE; if (cnp->cn_nameiop == DELETE || (wantparent && cnp->cn_nameiop != CREATE && cnp->cn_nameiop != LOOKUP)) docache = 0; rdonly = cnp->cn_flags & RDONLY; cnp->cn_flags &= ~ISSYMLINK; ndp->ni_dvp = NULL; /* * We use shared locks until we hit the parent of the last cn then * we adjust based on the requesting flags. */ cnp->cn_lkflags = LK_SHARED; dp = ndp->ni_startdir; ndp->ni_startdir = NULLVP; vn_lock(dp, compute_cn_lkflags(dp->v_mount, cnp->cn_lkflags | LK_RETRY, cnp->cn_flags)); dirloop: /* * Search a new directory. * * The last component of the filename is left accessible via * cnp->cn_nameptr for callers that need the name. Callers needing * the name set the SAVENAME flag. When done, they assume * responsibility for freeing the pathname buffer. */ for (cp = cnp->cn_nameptr; *cp != 0 && *cp != '/'; cp++) continue; cnp->cn_namelen = cp - cnp->cn_nameptr; if (cnp->cn_namelen > NAME_MAX) { error = ENAMETOOLONG; goto bad; } #ifdef NAMEI_DIAGNOSTIC { char c = *cp; *cp = '\0'; printf("{%s}: ", cnp->cn_nameptr); *cp = c; } #endif prev_ni_pathlen = ndp->ni_pathlen; ndp->ni_pathlen -= cnp->cn_namelen; KASSERT(ndp->ni_pathlen <= PATH_MAX, ("%s: ni_pathlen underflow to %zd\n", __func__, ndp->ni_pathlen)); prev_ni_next = ndp->ni_next; ndp->ni_next = cp; /* * Replace multiple slashes by a single slash and trailing slashes * by a null. This must be done before VOP_LOOKUP() because some * fs's don't know about trailing slashes. Remember if there were * trailing slashes to handle symlinks, existing non-directories * and non-existing files that won't be directories specially later. */ while (*cp == '/' && (cp[1] == '/' || cp[1] == '\0')) { cp++; ndp->ni_pathlen--; if (*cp == '\0') { *ndp->ni_next = '\0'; cnp->cn_flags |= TRAILINGSLASH; } } ndp->ni_next = cp; cnp->cn_flags |= MAKEENTRY; if (*cp == '\0' && docache == 0) cnp->cn_flags &= ~MAKEENTRY; if (cnp->cn_namelen == 2 && cnp->cn_nameptr[1] == '.' && cnp->cn_nameptr[0] == '.') cnp->cn_flags |= ISDOTDOT; else cnp->cn_flags &= ~ISDOTDOT; if (*ndp->ni_next == 0) cnp->cn_flags |= ISLASTCN; else cnp->cn_flags &= ~ISLASTCN; if ((cnp->cn_flags & ISLASTCN) != 0 && cnp->cn_namelen == 1 && cnp->cn_nameptr[0] == '.' && (cnp->cn_nameiop == DELETE || cnp->cn_nameiop == RENAME)) { error = EINVAL; goto bad; } nameicap_tracker_add(ndp, dp); /* * Check for degenerate name (e.g. / or "") * which is a way of talking about a directory, * e.g. like "/." or ".". */ if (cnp->cn_nameptr[0] == '\0') { if (dp->v_type != VDIR) { error = ENOTDIR; goto bad; } if (cnp->cn_nameiop != LOOKUP) { error = EISDIR; goto bad; } if (wantparent) { ndp->ni_dvp = dp; VREF(dp); } ndp->ni_vp = dp; if (cnp->cn_flags & AUDITVNODE1) AUDIT_ARG_VNODE1(dp); else if (cnp->cn_flags & AUDITVNODE2) AUDIT_ARG_VNODE2(dp); if (!(cnp->cn_flags & (LOCKPARENT | LOCKLEAF))) VOP_UNLOCK(dp, 0); /* XXX This should probably move to the top of function. */ if (cnp->cn_flags & SAVESTART) panic("lookup: SAVESTART"); goto success; } /* * Handle "..": five special cases. * 0. If doing a capability lookup and lookup_cap_dotdot is * disabled, return ENOTCAPABLE. * 1. Return an error if this is the last component of * the name and the operation is DELETE or RENAME. * 2. If at root directory (e.g. after chroot) * or at absolute root directory * then ignore it so can't get out. * 3. If this vnode is the root of a mounted * filesystem, then replace it with the * vnode which was mounted on so we take the * .. in the other filesystem. * 4. If the vnode is the top directory of * the jail or chroot, don't let them out. * 5. If doing a capability lookup and lookup_cap_dotdot is * enabled, return ENOTCAPABLE if the lookup would escape * from the initial file descriptor directory. Checks are * done by ensuring that namei() already traversed the * result of dotdot lookup. */ if (cnp->cn_flags & ISDOTDOT) { if ((ndp->ni_lcf & (NI_LCF_STRICTRELATIVE | NI_LCF_CAP_DOTDOT)) == NI_LCF_STRICTRELATIVE) { #ifdef KTRACE if (KTRPOINT(curthread, KTR_CAPFAIL)) ktrcapfail(CAPFAIL_LOOKUP, NULL, NULL); #endif error = ENOTCAPABLE; goto bad; } if ((cnp->cn_flags & ISLASTCN) != 0 && (cnp->cn_nameiop == DELETE || cnp->cn_nameiop == RENAME)) { error = EINVAL; goto bad; } for (;;) { for (pr = cnp->cn_cred->cr_prison; pr != NULL; pr = pr->pr_parent) if (dp == pr->pr_root) break; if (dp == ndp->ni_rootdir || dp == ndp->ni_topdir || dp == rootvnode || pr != NULL || ((dp->v_vflag & VV_ROOT) != 0 && (cnp->cn_flags & NOCROSSMOUNT) != 0)) { ndp->ni_dvp = dp; ndp->ni_vp = dp; VREF(dp); goto nextname; } if ((dp->v_vflag & VV_ROOT) == 0) break; if (dp->v_iflag & VI_DOOMED) { /* forced unmount */ error = ENOENT; goto bad; } tdp = dp; dp = dp->v_mount->mnt_vnodecovered; VREF(dp); vput(tdp); vn_lock(dp, compute_cn_lkflags(dp->v_mount, cnp->cn_lkflags | LK_RETRY, ISDOTDOT)); error = nameicap_check_dotdot(ndp, dp); if (error != 0) { #ifdef KTRACE if (KTRPOINT(curthread, KTR_CAPFAIL)) ktrcapfail(CAPFAIL_LOOKUP, NULL, NULL); #endif goto bad; } } } /* * We now have a segment name to search for, and a directory to search. */ unionlookup: #ifdef MAC if ((cnp->cn_flags & NOMACCHECK) == 0) { error = mac_vnode_check_lookup(cnp->cn_thread->td_ucred, dp, cnp); if (error) goto bad; } #endif ndp->ni_dvp = dp; ndp->ni_vp = NULL; ASSERT_VOP_LOCKED(dp, "lookup"); /* * If we have a shared lock we may need to upgrade the lock for the * last operation. */ if ((cnp->cn_flags & LOCKPARENT) && (cnp->cn_flags & ISLASTCN) && dp != vp_crossmp && VOP_ISLOCKED(dp) == LK_SHARED) vn_lock(dp, LK_UPGRADE|LK_RETRY); if ((dp->v_iflag & VI_DOOMED) != 0) { error = ENOENT; goto bad; } /* * If we're looking up the last component and we need an exclusive * lock, adjust our lkflags. */ if (needs_exclusive_leaf(dp->v_mount, cnp->cn_flags)) cnp->cn_lkflags = LK_EXCLUSIVE; #ifdef NAMEI_DIAGNOSTIC vn_printf(dp, "lookup in "); #endif lkflags_save = cnp->cn_lkflags; cnp->cn_lkflags = compute_cn_lkflags(dp->v_mount, cnp->cn_lkflags, cnp->cn_flags); error = VOP_LOOKUP(dp, &ndp->ni_vp, cnp); cnp->cn_lkflags = lkflags_save; if (error != 0) { KASSERT(ndp->ni_vp == NULL, ("leaf should be empty")); #ifdef NAMEI_DIAGNOSTIC printf("not found\n"); #endif if ((error == ENOENT) && (dp->v_vflag & VV_ROOT) && (dp->v_mount != NULL) && (dp->v_mount->mnt_flag & MNT_UNION)) { tdp = dp; dp = dp->v_mount->mnt_vnodecovered; VREF(dp); vput(tdp); vn_lock(dp, compute_cn_lkflags(dp->v_mount, cnp->cn_lkflags | LK_RETRY, cnp->cn_flags)); nameicap_tracker_add(ndp, dp); goto unionlookup; } if (error == ERELOOKUP) { vref(dp); ndp->ni_vp = dp; error = 0; relookup = 1; goto good; } if (error != EJUSTRETURN) goto bad; /* * At this point, we know we're at the end of the * pathname. If creating / renaming, we can consider * allowing the file or directory to be created / renamed, * provided we're not on a read-only filesystem. */ if (rdonly) { error = EROFS; goto bad; } /* trailing slash only allowed for directories */ if ((cnp->cn_flags & TRAILINGSLASH) && !(cnp->cn_flags & WILLBEDIR)) { error = ENOENT; goto bad; } if ((cnp->cn_flags & LOCKPARENT) == 0) VOP_UNLOCK(dp, 0); /* * We return with ni_vp NULL to indicate that the entry * doesn't currently exist, leaving a pointer to the * (possibly locked) directory vnode in ndp->ni_dvp. */ if (cnp->cn_flags & SAVESTART) { ndp->ni_startdir = ndp->ni_dvp; VREF(ndp->ni_startdir); } goto success; } good: #ifdef NAMEI_DIAGNOSTIC printf("found\n"); #endif dp = ndp->ni_vp; /* * Check to see if the vnode has been mounted on; * if so find the root of the mounted filesystem. */ while (dp->v_type == VDIR && (mp = dp->v_mountedhere) && (cnp->cn_flags & NOCROSSMOUNT) == 0) { if (vfs_busy(mp, 0)) continue; vput(dp); if (dp != ndp->ni_dvp) vput(ndp->ni_dvp); else vrele(ndp->ni_dvp); vrefact(vp_crossmp); ndp->ni_dvp = vp_crossmp; error = VFS_ROOT(mp, compute_cn_lkflags(mp, cnp->cn_lkflags, cnp->cn_flags), &tdp); vfs_unbusy(mp); if (vn_lock(vp_crossmp, LK_SHARED | LK_NOWAIT)) panic("vp_crossmp exclusively locked or reclaimed"); if (error) { dpunlocked = 1; goto bad2; } ndp->ni_vp = dp = tdp; } /* * Check for symbolic link */ if ((dp->v_type == VLNK) && ((cnp->cn_flags & FOLLOW) || (cnp->cn_flags & TRAILINGSLASH) || *ndp->ni_next == '/')) { cnp->cn_flags |= ISSYMLINK; if (dp->v_iflag & VI_DOOMED) { /* * We can't know whether the directory was mounted with * NOSYMFOLLOW, so we can't follow safely. */ error = ENOENT; goto bad2; } if (dp->v_mount->mnt_flag & MNT_NOSYMFOLLOW) { error = EACCES; goto bad2; } /* * Symlink code always expects an unlocked dvp. */ if (ndp->ni_dvp != ndp->ni_vp) { VOP_UNLOCK(ndp->ni_dvp, 0); ni_dvp_unlocked = 1; } goto success; } nextname: /* * Not a symbolic link that we will follow. Continue with the * next component if there is any; otherwise, we're done. */ KASSERT((cnp->cn_flags & ISLASTCN) || *ndp->ni_next == '/', ("lookup: invalid path state.")); if (relookup) { relookup = 0; ndp->ni_pathlen = prev_ni_pathlen; ndp->ni_next = prev_ni_next; if (ndp->ni_dvp != dp) vput(ndp->ni_dvp); else vrele(ndp->ni_dvp); goto dirloop; } if (cnp->cn_flags & ISDOTDOT) { error = nameicap_check_dotdot(ndp, ndp->ni_vp); if (error != 0) { #ifdef KTRACE if (KTRPOINT(curthread, KTR_CAPFAIL)) ktrcapfail(CAPFAIL_LOOKUP, NULL, NULL); #endif goto bad2; } } if (*ndp->ni_next == '/') { cnp->cn_nameptr = ndp->ni_next; while (*cnp->cn_nameptr == '/') { cnp->cn_nameptr++; ndp->ni_pathlen--; } if (ndp->ni_dvp != dp) vput(ndp->ni_dvp); else vrele(ndp->ni_dvp); goto dirloop; } /* * If we're processing a path with a trailing slash, * check that the end result is a directory. */ if ((cnp->cn_flags & TRAILINGSLASH) && dp->v_type != VDIR) { error = ENOTDIR; goto bad2; } /* * Disallow directory write attempts on read-only filesystems. */ if (rdonly && (cnp->cn_nameiop == DELETE || cnp->cn_nameiop == RENAME)) { error = EROFS; goto bad2; } if (cnp->cn_flags & SAVESTART) { ndp->ni_startdir = ndp->ni_dvp; VREF(ndp->ni_startdir); } if (!wantparent) { ni_dvp_unlocked = 2; if (ndp->ni_dvp != dp) vput(ndp->ni_dvp); else vrele(ndp->ni_dvp); } else if ((cnp->cn_flags & LOCKPARENT) == 0 && ndp->ni_dvp != dp) { VOP_UNLOCK(ndp->ni_dvp, 0); ni_dvp_unlocked = 1; } if (cnp->cn_flags & AUDITVNODE1) AUDIT_ARG_VNODE1(dp); else if (cnp->cn_flags & AUDITVNODE2) AUDIT_ARG_VNODE2(dp); if ((cnp->cn_flags & LOCKLEAF) == 0) VOP_UNLOCK(dp, 0); success: /* * Because of shared lookup we may have the vnode shared locked, but * the caller may want it to be exclusively locked. */ if (needs_exclusive_leaf(dp->v_mount, cnp->cn_flags) && VOP_ISLOCKED(dp) != LK_EXCLUSIVE) { vn_lock(dp, LK_UPGRADE | LK_RETRY); if (dp->v_iflag & VI_DOOMED) { error = ENOENT; goto bad2; } } return (0); bad2: if (ni_dvp_unlocked != 2) { if (dp != ndp->ni_dvp && !ni_dvp_unlocked) vput(ndp->ni_dvp); else vrele(ndp->ni_dvp); } bad: if (!dpunlocked) vput(dp); ndp->ni_vp = NULL; return (error); } /* * relookup - lookup a path name component * Used by lookup to re-acquire things. */ int relookup(struct vnode *dvp, struct vnode **vpp, struct componentname *cnp) { struct vnode *dp = NULL; /* the directory we are searching */ int wantparent; /* 1 => wantparent or lockparent flag */ int rdonly; /* lookup read-only flag bit */ int error = 0; KASSERT(cnp->cn_flags & ISLASTCN, ("relookup: Not given last component.")); /* * Setup: break out flag bits into variables. */ wantparent = cnp->cn_flags & (LOCKPARENT|WANTPARENT); KASSERT(wantparent, ("relookup: parent not wanted.")); rdonly = cnp->cn_flags & RDONLY; cnp->cn_flags &= ~ISSYMLINK; dp = dvp; cnp->cn_lkflags = LK_EXCLUSIVE; vn_lock(dp, LK_EXCLUSIVE | LK_RETRY); /* * Search a new directory. * * The last component of the filename is left accessible via * cnp->cn_nameptr for callers that need the name. Callers needing * the name set the SAVENAME flag. When done, they assume * responsibility for freeing the pathname buffer. */ #ifdef NAMEI_DIAGNOSTIC printf("{%s}: ", cnp->cn_nameptr); #endif /* * Check for "" which represents the root directory after slash * removal. */ if (cnp->cn_nameptr[0] == '\0') { /* * Support only LOOKUP for "/" because lookup() * can't succeed for CREATE, DELETE and RENAME. */ KASSERT(cnp->cn_nameiop == LOOKUP, ("nameiop must be LOOKUP")); KASSERT(dp->v_type == VDIR, ("dp is not a directory")); if (!(cnp->cn_flags & LOCKLEAF)) VOP_UNLOCK(dp, 0); *vpp = dp; /* XXX This should probably move to the top of function. */ if (cnp->cn_flags & SAVESTART) panic("lookup: SAVESTART"); return (0); } if (cnp->cn_flags & ISDOTDOT) panic ("relookup: lookup on dot-dot"); /* * We now have a segment name to search for, and a directory to search. */ #ifdef NAMEI_DIAGNOSTIC vn_printf(dp, "search in "); #endif if ((error = VOP_LOOKUP(dp, vpp, cnp)) != 0) { KASSERT(*vpp == NULL, ("leaf should be empty")); if (error != EJUSTRETURN) goto bad; /* * If creating and at end of pathname, then can consider * allowing file to be created. */ if (rdonly) { error = EROFS; goto bad; } /* ASSERT(dvp == ndp->ni_startdir) */ if (cnp->cn_flags & SAVESTART) VREF(dvp); if ((cnp->cn_flags & LOCKPARENT) == 0) VOP_UNLOCK(dp, 0); /* * We return with ni_vp NULL to indicate that the entry * doesn't currently exist, leaving a pointer to the * (possibly locked) directory vnode in ndp->ni_dvp. */ return (0); } dp = *vpp; /* * Disallow directory write attempts on read-only filesystems. */ if (rdonly && (cnp->cn_nameiop == DELETE || cnp->cn_nameiop == RENAME)) { if (dvp == dp) vrele(dvp); else vput(dvp); error = EROFS; goto bad; } /* * Set the parent lock/ref state to the requested state. */ if ((cnp->cn_flags & LOCKPARENT) == 0 && dvp != dp) { if (wantparent) VOP_UNLOCK(dvp, 0); else vput(dvp); } else if (!wantparent) vrele(dvp); /* * Check for symbolic link */ KASSERT(dp->v_type != VLNK || !(cnp->cn_flags & FOLLOW), ("relookup: symlink found.\n")); /* ASSERT(dvp == ndp->ni_startdir) */ if (cnp->cn_flags & SAVESTART) VREF(dvp); if ((cnp->cn_flags & LOCKLEAF) == 0) VOP_UNLOCK(dp, 0); return (0); bad: vput(dp); *vpp = NULL; return (error); } void NDINIT_ALL(struct nameidata *ndp, u_long op, u_long flags, enum uio_seg segflg, const char *namep, int dirfd, struct vnode *startdir, cap_rights_t *rightsp, struct thread *td) { ndp->ni_cnd.cn_nameiop = op; ndp->ni_cnd.cn_flags = flags; ndp->ni_segflg = segflg; ndp->ni_dirp = namep; ndp->ni_dirfd = dirfd; ndp->ni_startdir = startdir; + filecaps_init(&ndp->ni_filecaps); + ndp->ni_cnd.cn_thread = td; if (rightsp != NULL) ndp->ni_rightsneeded = *rightsp; else cap_rights_init(&ndp->ni_rightsneeded); - filecaps_init(&ndp->ni_filecaps); - ndp->ni_cnd.cn_thread = td; } /* * Free data allocated by namei(); see namei(9) for details. */ void NDFREE(struct nameidata *ndp, const u_int flags) { int unlock_dvp; int unlock_vp; unlock_dvp = 0; unlock_vp = 0; if (!(flags & NDF_NO_FREE_PNBUF) && (ndp->ni_cnd.cn_flags & HASBUF)) { uma_zfree(namei_zone, ndp->ni_cnd.cn_pnbuf); ndp->ni_cnd.cn_flags &= ~HASBUF; } if (!(flags & NDF_NO_VP_UNLOCK) && (ndp->ni_cnd.cn_flags & LOCKLEAF) && ndp->ni_vp) unlock_vp = 1; if (!(flags & NDF_NO_VP_RELE) && ndp->ni_vp) { if (unlock_vp) { vput(ndp->ni_vp); unlock_vp = 0; } else vrele(ndp->ni_vp); ndp->ni_vp = NULL; } if (unlock_vp) VOP_UNLOCK(ndp->ni_vp, 0); if (!(flags & NDF_NO_DVP_UNLOCK) && (ndp->ni_cnd.cn_flags & LOCKPARENT) && ndp->ni_dvp != ndp->ni_vp) unlock_dvp = 1; if (!(flags & NDF_NO_DVP_RELE) && (ndp->ni_cnd.cn_flags & (LOCKPARENT|WANTPARENT))) { if (unlock_dvp) { vput(ndp->ni_dvp); unlock_dvp = 0; } else vrele(ndp->ni_dvp); ndp->ni_dvp = NULL; } if (unlock_dvp) VOP_UNLOCK(ndp->ni_dvp, 0); if (!(flags & NDF_NO_STARTDIR_RELE) && (ndp->ni_cnd.cn_flags & SAVESTART)) { vrele(ndp->ni_startdir); ndp->ni_startdir = NULL; } } /* * Determine if there is a suitable alternate filename under the specified * prefix for the specified path. If the create flag is set, then the * alternate prefix will be used so long as the parent directory exists. * This is used by the various compatibility ABIs so that Linux binaries prefer * files under /compat/linux for example. The chosen path (whether under * the prefix or under /) is returned in a kernel malloc'd buffer pointed * to by pathbuf. The caller is responsible for free'ing the buffer from * the M_TEMP bucket if one is returned. */ int kern_alternate_path(struct thread *td, const char *prefix, const char *path, enum uio_seg pathseg, char **pathbuf, int create, int dirfd) { struct nameidata nd, ndroot; char *ptr, *buf, *cp; size_t len, sz; int error; buf = (char *) malloc(MAXPATHLEN, M_TEMP, M_WAITOK); *pathbuf = buf; /* Copy the prefix into the new pathname as a starting point. */ len = strlcpy(buf, prefix, MAXPATHLEN); if (len >= MAXPATHLEN) { *pathbuf = NULL; free(buf, M_TEMP); return (EINVAL); } sz = MAXPATHLEN - len; ptr = buf + len; /* Append the filename to the prefix. */ if (pathseg == UIO_SYSSPACE) error = copystr(path, ptr, sz, &len); else error = copyinstr(path, ptr, sz, &len); if (error) { *pathbuf = NULL; free(buf, M_TEMP); return (error); } /* Only use a prefix with absolute pathnames. */ if (*ptr != '/') { error = EINVAL; goto keeporig; } if (dirfd != AT_FDCWD) { /* * We want the original because the "prefix" is * included in the already opened dirfd. */ bcopy(ptr, buf, len); return (0); } /* * We know that there is a / somewhere in this pathname. * Search backwards for it, to find the file's parent dir * to see if it exists in the alternate tree. If it does, * and we want to create a file (cflag is set). We don't * need to worry about the root comparison in this case. */ if (create) { for (cp = &ptr[len] - 1; *cp != '/'; cp--); *cp = '\0'; NDINIT(&nd, LOOKUP, NOFOLLOW, UIO_SYSSPACE, buf, td); error = namei(&nd); *cp = '/'; if (error != 0) goto keeporig; } else { NDINIT(&nd, LOOKUP, NOFOLLOW, UIO_SYSSPACE, buf, td); error = namei(&nd); if (error != 0) goto keeporig; /* * We now compare the vnode of the prefix to the one * vnode asked. If they resolve to be the same, then we * ignore the match so that the real root gets used. * This avoids the problem of traversing "../.." to find the * root directory and never finding it, because "/" resolves * to the emulation root directory. This is expensive :-( */ NDINIT(&ndroot, LOOKUP, FOLLOW, UIO_SYSSPACE, prefix, td); /* We shouldn't ever get an error from this namei(). */ error = namei(&ndroot); if (error == 0) { if (nd.ni_vp == ndroot.ni_vp) error = ENOENT; NDFREE(&ndroot, NDF_ONLY_PNBUF); vrele(ndroot.ni_vp); } } NDFREE(&nd, NDF_ONLY_PNBUF); vrele(nd.ni_vp); keeporig: /* If there was an error, use the original path name. */ if (error) bcopy(ptr, buf, len); return (error); } Index: head/sys/sys/filedesc.h =================================================================== --- head/sys/sys/filedesc.h (revision 342057) +++ head/sys/sys/filedesc.h (revision 342058) @@ -1,250 +1,256 @@ /*- * SPDX-License-Identifier: BSD-3-Clause * * Copyright (c) 1990, 1993 * The Regents of the University of California. 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. 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. * * @(#)filedesc.h 8.1 (Berkeley) 6/2/93 * $FreeBSD$ */ #ifndef _SYS_FILEDESC_H_ #define _SYS_FILEDESC_H_ #include #include #include #include #include #include #include #include struct filecaps { cap_rights_t fc_rights; /* per-descriptor capability rights */ u_long *fc_ioctls; /* per-descriptor allowed ioctls */ int16_t fc_nioctls; /* fc_ioctls array size */ uint32_t fc_fcntls; /* per-descriptor allowed fcntls */ }; struct filedescent { struct file *fde_file; /* file structure for open file */ struct filecaps fde_caps; /* per-descriptor rights */ uint8_t fde_flags; /* per-process open file flags */ seq_t fde_seq; /* keep file and caps in sync */ }; #define fde_rights fde_caps.fc_rights #define fde_fcntls fde_caps.fc_fcntls #define fde_ioctls fde_caps.fc_ioctls #define fde_nioctls fde_caps.fc_nioctls #define fde_change_size (offsetof(struct filedescent, fde_seq)) struct fdescenttbl { int fdt_nfiles; /* number of open files allocated */ struct filedescent fdt_ofiles[0]; /* open files */ }; #define fd_seq(fdt, fd) (&(fdt)->fdt_ofiles[(fd)].fde_seq) /* * This structure is used for the management of descriptors. It may be * shared by multiple processes. */ #define NDSLOTTYPE u_long struct filedesc { struct fdescenttbl *fd_files; /* open files table */ struct vnode *fd_cdir; /* current directory */ struct vnode *fd_rdir; /* root directory */ struct vnode *fd_jdir; /* jail root directory */ NDSLOTTYPE *fd_map; /* bitmap of free fds */ int fd_lastfile; /* high-water mark of fd_ofiles */ int fd_freefile; /* approx. next free file */ u_short fd_cmask; /* mask for file creation */ int fd_refcnt; /* thread reference count */ int fd_holdcnt; /* hold count on structure + mutex */ struct sx fd_sx; /* protects members of this struct */ struct kqlist fd_kqlist; /* list of kqueues on this filedesc */ int fd_holdleaderscount; /* block fdfree() for shared close() */ int fd_holdleaderswakeup; /* fdfree() needs wakeup */ }; /* * Structure to keep track of (process leader, struct fildedesc) tuples. * Each process has a pointer to such a structure when detailed tracking * is needed, e.g., when rfork(RFPROC | RFMEM) causes a file descriptor * table to be shared by processes having different "p_leader" pointers * and thus distinct POSIX style locks. * * fdl_refcount and fdl_holdcount are protected by struct filedesc mtx. */ struct filedesc_to_leader { int fdl_refcount; /* references from struct proc */ int fdl_holdcount; /* temporary hold during closef */ int fdl_wakeup; /* fdfree() waits on closef() */ struct proc *fdl_leader; /* owner of POSIX locks */ /* Circular list: */ struct filedesc_to_leader *fdl_prev; struct filedesc_to_leader *fdl_next; }; #define fd_nfiles fd_files->fdt_nfiles #define fd_ofiles fd_files->fdt_ofiles /* * Per-process open flags. */ #define UF_EXCLOSE 0x01 /* auto-close on exec */ #ifdef _KERNEL /* Lock a file descriptor table. */ #define FILEDESC_LOCK_INIT(fdp) sx_init(&(fdp)->fd_sx, "filedesc structure") #define FILEDESC_LOCK_DESTROY(fdp) sx_destroy(&(fdp)->fd_sx) #define FILEDESC_LOCK(fdp) (&(fdp)->fd_sx) #define FILEDESC_XLOCK(fdp) sx_xlock(&(fdp)->fd_sx) #define FILEDESC_XUNLOCK(fdp) sx_xunlock(&(fdp)->fd_sx) #define FILEDESC_SLOCK(fdp) sx_slock(&(fdp)->fd_sx) #define FILEDESC_SUNLOCK(fdp) sx_sunlock(&(fdp)->fd_sx) #define FILEDESC_LOCK_ASSERT(fdp) sx_assert(&(fdp)->fd_sx, SX_LOCKED | \ SX_NOTRECURSED) #define FILEDESC_XLOCK_ASSERT(fdp) sx_assert(&(fdp)->fd_sx, SX_XLOCKED | \ SX_NOTRECURSED) #define FILEDESC_UNLOCK_ASSERT(fdp) sx_assert(&(fdp)->fd_sx, SX_UNLOCKED) /* Operation types for kern_dup(). */ enum { FDDUP_NORMAL, /* dup() behavior. */ FDDUP_FCNTL, /* fcntl()-style errors. */ FDDUP_FIXED, /* Force fixed allocation. */ FDDUP_MUSTREPLACE, /* Target must exist. */ FDDUP_LASTMODE, }; /* Flags for kern_dup(). */ #define FDDUP_FLAG_CLOEXEC 0x1 /* Atomically set UF_EXCLOSE. */ /* For backward compatibility. */ #define falloc(td, resultfp, resultfd, flags) \ falloc_caps(td, resultfp, resultfd, flags, NULL) struct thread; -void filecaps_init(struct filecaps *fcaps); +static __inline void +filecaps_init(struct filecaps *fcaps) +{ + + bzero(fcaps, sizeof(*fcaps)); + fcaps->fc_nioctls = -1; +} bool filecaps_copy(const struct filecaps *src, struct filecaps *dst, bool locked); void filecaps_move(struct filecaps *src, struct filecaps *dst); void filecaps_free(struct filecaps *fcaps); int closef(struct file *fp, struct thread *td); int dupfdopen(struct thread *td, struct filedesc *fdp, int dfd, int mode, int openerror, int *indxp); int falloc_caps(struct thread *td, struct file **resultfp, int *resultfd, int flags, struct filecaps *fcaps); int falloc_noinstall(struct thread *td, struct file **resultfp); void _finstall(struct filedesc *fdp, struct file *fp, int fd, int flags, struct filecaps *fcaps); int finstall(struct thread *td, struct file *fp, int *resultfd, int flags, struct filecaps *fcaps); int fdalloc(struct thread *td, int minfd, int *result); int fdallocn(struct thread *td, int minfd, int *fds, int n); int fdcheckstd(struct thread *td); void fdclose(struct thread *td, struct file *fp, int idx); void fdcloseexec(struct thread *td); void fdsetugidsafety(struct thread *td); struct filedesc *fdcopy(struct filedesc *fdp); int fdcopy_remapped(struct filedesc *fdp, const int *fds, size_t nfds, struct filedesc **newfdp); void fdinstall_remapped(struct thread *td, struct filedesc *fdp); void fdunshare(struct thread *td); void fdescfree(struct thread *td); void fdescfree_remapped(struct filedesc *fdp); struct filedesc *fdinit(struct filedesc *fdp, bool prepfiles); struct filedesc *fdshare(struct filedesc *fdp); struct filedesc_to_leader * filedesc_to_leader_alloc(struct filedesc_to_leader *old, struct filedesc *fdp, struct proc *leader); int getvnode(struct thread *td, int fd, cap_rights_t *rightsp, struct file **fpp); void mountcheckdirs(struct vnode *olddp, struct vnode *newdp); int fget_cap_locked(struct filedesc *fdp, int fd, cap_rights_t *needrightsp, struct file **fpp, struct filecaps *havecapsp); int fget_cap(struct thread *td, int fd, cap_rights_t *needrightsp, struct file **fpp, struct filecaps *havecapsp); /* Return a referenced file from an unlocked descriptor. */ int fget_unlocked(struct filedesc *fdp, int fd, cap_rights_t *needrightsp, struct file **fpp, seq_t *seqp); /* Requires a FILEDESC_{S,X}LOCK held and returns without a ref. */ static __inline struct file * fget_locked(struct filedesc *fdp, int fd) { FILEDESC_LOCK_ASSERT(fdp); if (__predict_false((u_int)fd >= fdp->fd_nfiles)) return (NULL); return (fdp->fd_ofiles[fd].fde_file); } static __inline struct filedescent * fdeget_locked(struct filedesc *fdp, int fd) { struct filedescent *fde; FILEDESC_LOCK_ASSERT(fdp); if (__predict_false((u_int)fd >= fdp->fd_nfiles)) return (NULL); fde = &fdp->fd_ofiles[fd]; if (__predict_false(fde->fde_file == NULL)) return (NULL); return (fde); } #ifdef CAPABILITIES static __inline bool fd_modified(struct filedesc *fdp, int fd, seq_t seq) { return (!seq_consistent(fd_seq(fdp->fd_files, fd), seq)); } #endif /* cdir/rdir/jdir manipulation functions. */ void pwd_chdir(struct thread *td, struct vnode *vp); int pwd_chroot(struct thread *td, struct vnode *vp); void pwd_ensure_dirs(void); #endif /* _KERNEL */ #endif /* !_SYS_FILEDESC_H_ */