diff options
Diffstat (limited to 'freebsd/sys/kern/kern_descrip.c')
| -rw-r--r-- | freebsd/sys/kern/kern_descrip.c | 4283 |
1 files changed, 4283 insertions, 0 deletions
diff --git a/freebsd/sys/kern/kern_descrip.c b/freebsd/sys/kern/kern_descrip.c new file mode 100644 index 00000000..423968b2 --- /dev/null +++ b/freebsd/sys/kern/kern_descrip.c @@ -0,0 +1,4283 @@ +/*- + * 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 <sys/cdefs.h> +__FBSDID("$FreeBSD$"); + +#include "opt_capsicum.h" +#include "opt_ddb.h" +#include "opt_ktrace.h" + +#include <sys/param.h> +#include <sys/systm.h> + +#include <sys/capsicum.h> +#include <sys/conf.h> +#include <sys/fcntl.h> +#include <sys/file.h> +#include <sys/filedesc.h> +#include <sys/filio.h> +#include <sys/jail.h> +#include <sys/kernel.h> +#include <sys/limits.h> +#include <sys/lock.h> +#include <sys/malloc.h> +#include <sys/mount.h> +#include <sys/mutex.h> +#include <sys/namei.h> +#include <sys/selinfo.h> +#include <sys/priv.h> +#include <sys/proc.h> +#include <sys/protosw.h> +#include <sys/racct.h> +#include <sys/resourcevar.h> +#include <sys/sbuf.h> +#include <sys/signalvar.h> +#include <sys/kdb.h> +#include <sys/stat.h> +#include <sys/sx.h> +#include <sys/syscallsubr.h> +#include <sys/sysctl.h> +#include <sys/sysproto.h> +#include <sys/unistd.h> +#include <sys/user.h> +#include <sys/vnode.h> +#ifdef KTRACE +#include <sys/ktrace.h> +#endif + +#include <net/vnet.h> + +#include <security/audit/audit.h> + +#include <vm/uma.h> +#include <vm/vm.h> + +#include <ddb/ddb.h> + +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 = fd_first_free(fdp, fd, fdp->fd_nfiles); +} + +/* + * 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] = + min((int)lim_cur(td, RLIMIT_NOFILE), maxfilesperproc); +#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 != 0) + return (error); + flg = F_REMOTE; + goto do_setlk; + + case F_SETLKW: + flg |= F_WAIT; + /* FALLTHROUGH F_SETLK */ + + case F_SETLK: + do_setlk: + flp = (struct flock *)arg; + if ((flg & F_REMOTE) != 0 && flp->l_sysid == 0) { + error = EINVAL; + break; + } + + 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; + } + + 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: + 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; + if (vp->v_type != VREG) { + fdrop(fp, td); + error = ENOTTY; + break; + } + + /* + * 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; + arg = MIN(arg, INT_MAX - bsize + 1); + fp->f_seqcount = MIN(IO_SEQMAX, + (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; + + 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; + } + + oldfde = &fdp->fd_ofiles[old]; + if (!fhold(oldfde->fde_file)) + 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) { + fdrop(oldfde->fde_file, td); + goto unlock; + } + break; + case FDDUP_MUSTREPLACE: + /* Target file descriptor must exist. */ + if (fget_locked(fdp, new) == NULL) { + fdrop(oldfde->fde_file, td); + 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_enable) { + PROC_LOCK(p); + error = racct_set(p, RACCT_NOFILE, new + 1); + PROC_UNLOCK(p); + if (error != 0) { + error = EMFILE; + fdrop(oldfde->fde_file, td); + 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")); + + 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 + filecaps_free_finish(oioctls); + 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); + } + + 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. + */ + knote_fdclose(td, fd); + + /* + * We need to notify mqueue if the object is of type mqueue. + */ + if (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 (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 (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_enable) { + PROC_LOCK(p); + error = racct_set(p, RACCT_NOFILE, allocfd); + PROC_UNLOCK(p); + 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); + + if (!fhold(fp)) + return (EBADF); + FILEDESC_XLOCK(fdp); + if ((error = fdalloc(td, 0, fd))) { + FILEDESC_XUNLOCK(fdp); + fdrop(fp, td); + return (error); + } + _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 || + !fhold(ofde->fde_file)) { + 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); + 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; + } + if (!fhold(nfde->fde_file)) { + error = EBADF; + goto bad; + } + nfde = &newfdp->fd_ofiles[i]; + *nfde = *ofde; + filecaps_copy(&ofde->fde_caps, &nfde->fde_caps, true); + 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 || + !fhold(fp)) + continue; + 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_enable) { + PROC_LOCK(p); + racct_set(p, RACCT_NOFILE, 0); + PROC_UNLOCK(p); + } +#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. + */ +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)) + error = EBADF; + 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 ((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_load(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; + } + if (__predict_false(count + 1 < count)) + return (EBADF); + + /* + * Use an acquire barrier to force re-reading of fdt so it is + * refreshed for verification. + */ + if (__predict_false(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 + cap_rights_t fdrights; + 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 (maxprotp != NULL) + fdrights = *cap_rights(fdp, fd); + if (!fd_modified(fdp, fd, seq)) + break; + fdrop(*fpp, td); + } + + /* + * If requested, convert capability rights to access flags. + */ + if (maxprotp != NULL) + *maxprotp = cap_rights_to_vmprot(&fdrights); +#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); + } + if (!fhold(fp)) { + fdunused(fdp, indx); + FILEDESC_XUNLOCK(fdp); + return (EBADF); + } + 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. */ +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 <addr>\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); |