freebsd-dev/sys/compat/cloudabi/cloudabi_fd.c
Kyle Evans 535b1df993 shm: correct KPI mistake introduced around memfd_create
When file sealing and shm_open2 were introduced, we should have grown a new
kern_shm_open2 helper that did the brunt of the work with the new interface
while kern_shm_open remains the same. Instead, more complexity was
introduced to kern_shm_open to handle the additional features and consumers
had to keep changing in somewhat awkward ways, and a kern_shm_open2 was
added to wrap kern_shm_open.

Backpedal on this and correct the situation- kern_shm_open returns to the
interface it had prior to file sealing being introduced, and neither
function needs an initial_seals argument anymore as it's handled in
kern_shm_open2 based on the shmflags.
2020-01-05 04:06:40 +00:00

476 lines
14 KiB
C

/*-
* Copyright (c) 2015 Nuxi, https://nuxi.nl/
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/capsicum.h>
#include <sys/fcntl.h>
#include <sys/filedesc.h>
#include <sys/proc.h>
#include <sys/mman.h>
#include <sys/socketvar.h>
#include <sys/syscallsubr.h>
#include <sys/sysproto.h>
#include <sys/systm.h>
#include <sys/unistd.h>
#include <sys/vnode.h>
#include <contrib/cloudabi/cloudabi_types_common.h>
#include <compat/cloudabi/cloudabi_proto.h>
#include <compat/cloudabi/cloudabi_util.h>
/* Translation between CloudABI and Capsicum rights. */
#define RIGHTS_MAPPINGS \
MAPPING(CLOUDABI_RIGHT_FD_DATASYNC, CAP_FSYNC) \
MAPPING(CLOUDABI_RIGHT_FD_READ, CAP_READ) \
MAPPING(CLOUDABI_RIGHT_FD_SEEK, CAP_SEEK) \
MAPPING(CLOUDABI_RIGHT_FD_STAT_PUT_FLAGS, CAP_FCNTL) \
MAPPING(CLOUDABI_RIGHT_FD_SYNC, CAP_FSYNC) \
MAPPING(CLOUDABI_RIGHT_FD_TELL, CAP_SEEK_TELL) \
MAPPING(CLOUDABI_RIGHT_FD_WRITE, CAP_WRITE) \
MAPPING(CLOUDABI_RIGHT_FILE_ADVISE) \
MAPPING(CLOUDABI_RIGHT_FILE_ALLOCATE, CAP_WRITE) \
MAPPING(CLOUDABI_RIGHT_FILE_CREATE_DIRECTORY, CAP_MKDIRAT) \
MAPPING(CLOUDABI_RIGHT_FILE_CREATE_FILE, CAP_CREATE) \
MAPPING(CLOUDABI_RIGHT_FILE_LINK_SOURCE, CAP_LINKAT_SOURCE) \
MAPPING(CLOUDABI_RIGHT_FILE_LINK_TARGET, CAP_LINKAT_TARGET) \
MAPPING(CLOUDABI_RIGHT_FILE_OPEN, CAP_LOOKUP) \
MAPPING(CLOUDABI_RIGHT_FILE_READDIR, CAP_READ) \
MAPPING(CLOUDABI_RIGHT_FILE_READLINK, CAP_LOOKUP) \
MAPPING(CLOUDABI_RIGHT_FILE_RENAME_SOURCE, CAP_RENAMEAT_SOURCE) \
MAPPING(CLOUDABI_RIGHT_FILE_RENAME_TARGET, CAP_RENAMEAT_TARGET) \
MAPPING(CLOUDABI_RIGHT_FILE_STAT_FGET, CAP_FSTAT) \
MAPPING(CLOUDABI_RIGHT_FILE_STAT_FPUT_SIZE, CAP_FTRUNCATE) \
MAPPING(CLOUDABI_RIGHT_FILE_STAT_FPUT_TIMES, CAP_FUTIMES) \
MAPPING(CLOUDABI_RIGHT_FILE_STAT_GET, CAP_FSTATAT) \
MAPPING(CLOUDABI_RIGHT_FILE_STAT_PUT_TIMES, CAP_FUTIMESAT) \
MAPPING(CLOUDABI_RIGHT_FILE_SYMLINK, CAP_SYMLINKAT) \
MAPPING(CLOUDABI_RIGHT_FILE_UNLINK, CAP_UNLINKAT) \
MAPPING(CLOUDABI_RIGHT_MEM_MAP, CAP_MMAP) \
MAPPING(CLOUDABI_RIGHT_MEM_MAP_EXEC, CAP_MMAP_X) \
MAPPING(CLOUDABI_RIGHT_POLL_FD_READWRITE, CAP_EVENT) \
MAPPING(CLOUDABI_RIGHT_POLL_PROC_TERMINATE, CAP_EVENT) \
MAPPING(CLOUDABI_RIGHT_PROC_EXEC, CAP_FEXECVE) \
MAPPING(CLOUDABI_RIGHT_SOCK_SHUTDOWN, CAP_SHUTDOWN) \
int
cloudabi_sys_fd_close(struct thread *td, struct cloudabi_sys_fd_close_args *uap)
{
return (kern_close(td, uap->fd));
}
int
cloudabi_sys_fd_create1(struct thread *td,
struct cloudabi_sys_fd_create1_args *uap)
{
struct filecaps fcaps = {};
switch (uap->type) {
case CLOUDABI_FILETYPE_SHARED_MEMORY:
cap_rights_init(&fcaps.fc_rights, CAP_FSTAT, CAP_FTRUNCATE,
CAP_MMAP_RWX);
return (kern_shm_open(td, SHM_ANON, O_RDWR | O_CLOEXEC, 0,
&fcaps));
default:
return (EINVAL);
}
}
int
cloudabi_sys_fd_create2(struct thread *td,
struct cloudabi_sys_fd_create2_args *uap)
{
int fds[2];
int error, type;
switch (uap->type) {
case CLOUDABI_FILETYPE_SOCKET_DGRAM:
type = SOCK_DGRAM;
break;
case CLOUDABI_FILETYPE_SOCKET_STREAM:
type = SOCK_STREAM;
break;
default:
return (EINVAL);
}
error = kern_socketpair(td, AF_UNIX, type, 0, fds);
if (error == 0) {
td->td_retval[0] = fds[0];
td->td_retval[1] = fds[1];
}
return (0);
}
int
cloudabi_sys_fd_datasync(struct thread *td,
struct cloudabi_sys_fd_datasync_args *uap)
{
return (kern_fsync(td, uap->fd, false));
}
int
cloudabi_sys_fd_dup(struct thread *td, struct cloudabi_sys_fd_dup_args *uap)
{
return (kern_dup(td, FDDUP_NORMAL, 0, uap->from, 0));
}
int
cloudabi_sys_fd_replace(struct thread *td,
struct cloudabi_sys_fd_replace_args *uap)
{
int error;
/*
* CloudABI's equivalent to dup2(). CloudABI processes should
* not depend on hardcoded file descriptor layouts, but simply
* use the file descriptor numbers that are allocated by the
* kernel. Duplicating file descriptors to arbitrary numbers
* should not be done.
*
* Invoke kern_dup() with FDDUP_MUSTREPLACE, so that we return
* EBADF when duplicating to a nonexistent file descriptor. Also
* clear the return value, as this system call yields no return
* value.
*/
error = kern_dup(td, FDDUP_MUSTREPLACE, 0, uap->from, uap->to);
td->td_retval[0] = 0;
return (error);
}
int
cloudabi_sys_fd_seek(struct thread *td, struct cloudabi_sys_fd_seek_args *uap)
{
int whence;
switch (uap->whence) {
case CLOUDABI_WHENCE_CUR:
whence = SEEK_CUR;
break;
case CLOUDABI_WHENCE_END:
whence = SEEK_END;
break;
case CLOUDABI_WHENCE_SET:
whence = SEEK_SET;
break;
default:
return (EINVAL);
}
return (kern_lseek(td, uap->fd, uap->offset, whence));
}
/* Converts a file descriptor to a CloudABI file descriptor type. */
cloudabi_filetype_t
cloudabi_convert_filetype(const struct file *fp)
{
struct socket *so;
struct vnode *vp;
switch (fp->f_type) {
case DTYPE_FIFO:
return (CLOUDABI_FILETYPE_SOCKET_STREAM);
case DTYPE_PIPE:
return (CLOUDABI_FILETYPE_SOCKET_STREAM);
case DTYPE_PROCDESC:
return (CLOUDABI_FILETYPE_PROCESS);
case DTYPE_SHM:
return (CLOUDABI_FILETYPE_SHARED_MEMORY);
case DTYPE_SOCKET:
so = fp->f_data;
switch (so->so_type) {
case SOCK_DGRAM:
return (CLOUDABI_FILETYPE_SOCKET_DGRAM);
case SOCK_STREAM:
return (CLOUDABI_FILETYPE_SOCKET_STREAM);
default:
return (CLOUDABI_FILETYPE_UNKNOWN);
}
case DTYPE_VNODE:
vp = fp->f_vnode;
switch (vp->v_type) {
case VBLK:
return (CLOUDABI_FILETYPE_BLOCK_DEVICE);
case VCHR:
return (CLOUDABI_FILETYPE_CHARACTER_DEVICE);
case VDIR:
return (CLOUDABI_FILETYPE_DIRECTORY);
case VFIFO:
return (CLOUDABI_FILETYPE_SOCKET_STREAM);
case VLNK:
return (CLOUDABI_FILETYPE_SYMBOLIC_LINK);
case VREG:
return (CLOUDABI_FILETYPE_REGULAR_FILE);
case VSOCK:
return (CLOUDABI_FILETYPE_SOCKET_STREAM);
default:
return (CLOUDABI_FILETYPE_UNKNOWN);
}
default:
return (CLOUDABI_FILETYPE_UNKNOWN);
}
}
/* Removes rights that conflict with the file descriptor type. */
void
cloudabi_remove_conflicting_rights(cloudabi_filetype_t filetype,
cloudabi_rights_t *base, cloudabi_rights_t *inheriting)
{
/*
* CloudABI has a small number of additional rights bits to
* disambiguate between multiple purposes. Remove the bits that
* don't apply to the type of the file descriptor.
*
* As file descriptor access modes (O_ACCMODE) has been fully
* replaced by rights bits, CloudABI distinguishes between
* rights that apply to the file descriptor itself (base) versus
* rights of new file descriptors derived from them
* (inheriting). The code below approximates the pair by
* decomposing depending on the file descriptor type.
*
* We need to be somewhat accurate about which actions can
* actually be performed on the file descriptor, as functions
* like fcntl(fd, F_GETFL) are emulated on top of this.
*/
switch (filetype) {
case CLOUDABI_FILETYPE_DIRECTORY:
*base &= CLOUDABI_RIGHT_FD_STAT_PUT_FLAGS |
CLOUDABI_RIGHT_FD_SYNC | CLOUDABI_RIGHT_FILE_ADVISE |
CLOUDABI_RIGHT_FILE_CREATE_DIRECTORY |
CLOUDABI_RIGHT_FILE_CREATE_FILE |
CLOUDABI_RIGHT_FILE_LINK_SOURCE |
CLOUDABI_RIGHT_FILE_LINK_TARGET |
CLOUDABI_RIGHT_FILE_OPEN |
CLOUDABI_RIGHT_FILE_READDIR |
CLOUDABI_RIGHT_FILE_READLINK |
CLOUDABI_RIGHT_FILE_RENAME_SOURCE |
CLOUDABI_RIGHT_FILE_RENAME_TARGET |
CLOUDABI_RIGHT_FILE_STAT_FGET |
CLOUDABI_RIGHT_FILE_STAT_FPUT_TIMES |
CLOUDABI_RIGHT_FILE_STAT_GET |
CLOUDABI_RIGHT_FILE_STAT_PUT_TIMES |
CLOUDABI_RIGHT_FILE_SYMLINK |
CLOUDABI_RIGHT_FILE_UNLINK |
CLOUDABI_RIGHT_POLL_FD_READWRITE;
*inheriting &= CLOUDABI_RIGHT_FD_DATASYNC |
CLOUDABI_RIGHT_FD_READ |
CLOUDABI_RIGHT_FD_SEEK |
CLOUDABI_RIGHT_FD_STAT_PUT_FLAGS |
CLOUDABI_RIGHT_FD_SYNC |
CLOUDABI_RIGHT_FD_TELL |
CLOUDABI_RIGHT_FD_WRITE |
CLOUDABI_RIGHT_FILE_ADVISE |
CLOUDABI_RIGHT_FILE_ALLOCATE |
CLOUDABI_RIGHT_FILE_CREATE_DIRECTORY |
CLOUDABI_RIGHT_FILE_CREATE_FILE |
CLOUDABI_RIGHT_FILE_LINK_SOURCE |
CLOUDABI_RIGHT_FILE_LINK_TARGET |
CLOUDABI_RIGHT_FILE_OPEN |
CLOUDABI_RIGHT_FILE_READDIR |
CLOUDABI_RIGHT_FILE_READLINK |
CLOUDABI_RIGHT_FILE_RENAME_SOURCE |
CLOUDABI_RIGHT_FILE_RENAME_TARGET |
CLOUDABI_RIGHT_FILE_STAT_FGET |
CLOUDABI_RIGHT_FILE_STAT_FPUT_SIZE |
CLOUDABI_RIGHT_FILE_STAT_FPUT_TIMES |
CLOUDABI_RIGHT_FILE_STAT_GET |
CLOUDABI_RIGHT_FILE_STAT_PUT_TIMES |
CLOUDABI_RIGHT_FILE_SYMLINK |
CLOUDABI_RIGHT_FILE_UNLINK |
CLOUDABI_RIGHT_MEM_MAP |
CLOUDABI_RIGHT_MEM_MAP_EXEC |
CLOUDABI_RIGHT_POLL_FD_READWRITE |
CLOUDABI_RIGHT_PROC_EXEC;
break;
case CLOUDABI_FILETYPE_PROCESS:
*base &= ~(CLOUDABI_RIGHT_FILE_ADVISE |
CLOUDABI_RIGHT_POLL_FD_READWRITE);
*inheriting = 0;
break;
case CLOUDABI_FILETYPE_REGULAR_FILE:
*base &= CLOUDABI_RIGHT_FD_DATASYNC |
CLOUDABI_RIGHT_FD_READ |
CLOUDABI_RIGHT_FD_SEEK |
CLOUDABI_RIGHT_FD_STAT_PUT_FLAGS |
CLOUDABI_RIGHT_FD_SYNC |
CLOUDABI_RIGHT_FD_TELL |
CLOUDABI_RIGHT_FD_WRITE |
CLOUDABI_RIGHT_FILE_ADVISE |
CLOUDABI_RIGHT_FILE_ALLOCATE |
CLOUDABI_RIGHT_FILE_STAT_FGET |
CLOUDABI_RIGHT_FILE_STAT_FPUT_SIZE |
CLOUDABI_RIGHT_FILE_STAT_FPUT_TIMES |
CLOUDABI_RIGHT_MEM_MAP |
CLOUDABI_RIGHT_MEM_MAP_EXEC |
CLOUDABI_RIGHT_POLL_FD_READWRITE |
CLOUDABI_RIGHT_PROC_EXEC;
*inheriting = 0;
break;
case CLOUDABI_FILETYPE_SHARED_MEMORY:
*base &= ~(CLOUDABI_RIGHT_FD_SEEK |
CLOUDABI_RIGHT_FD_TELL |
CLOUDABI_RIGHT_FILE_ADVISE |
CLOUDABI_RIGHT_FILE_ALLOCATE |
CLOUDABI_RIGHT_FILE_READDIR);
*inheriting = 0;
break;
case CLOUDABI_FILETYPE_SOCKET_DGRAM:
case CLOUDABI_FILETYPE_SOCKET_STREAM:
*base &= CLOUDABI_RIGHT_FD_READ |
CLOUDABI_RIGHT_FD_STAT_PUT_FLAGS |
CLOUDABI_RIGHT_FD_WRITE |
CLOUDABI_RIGHT_FILE_STAT_FGET |
CLOUDABI_RIGHT_POLL_FD_READWRITE |
CLOUDABI_RIGHT_SOCK_SHUTDOWN;
break;
default:
*inheriting = 0;
break;
}
}
/* Converts FreeBSD's Capsicum rights to CloudABI's set of rights. */
static void
convert_capabilities(const cap_rights_t *capabilities,
cloudabi_filetype_t filetype, cloudabi_rights_t *base,
cloudabi_rights_t *inheriting)
{
cloudabi_rights_t rights;
/* Convert FreeBSD bits to CloudABI bits. */
rights = 0;
#define MAPPING(cloudabi, ...) do { \
if (cap_rights_is_set(capabilities, ##__VA_ARGS__)) \
rights |= (cloudabi); \
} while (0);
RIGHTS_MAPPINGS
#undef MAPPING
*base = rights;
*inheriting = rights;
cloudabi_remove_conflicting_rights(filetype, base, inheriting);
}
int
cloudabi_sys_fd_stat_get(struct thread *td,
struct cloudabi_sys_fd_stat_get_args *uap)
{
cloudabi_fdstat_t fsb = {0};
struct file *fp;
cap_rights_t rights;
struct filecaps fcaps;
int error, oflags;
/* Obtain file descriptor properties. */
error = fget_cap(td, uap->fd, cap_rights_init(&rights), &fp,
&fcaps);
if (error != 0)
return (error);
oflags = OFLAGS(fp->f_flag);
fsb.fs_filetype = cloudabi_convert_filetype(fp);
fdrop(fp, td);
/* Convert file descriptor flags. */
if (oflags & O_APPEND)
fsb.fs_flags |= CLOUDABI_FDFLAG_APPEND;
if (oflags & O_NONBLOCK)
fsb.fs_flags |= CLOUDABI_FDFLAG_NONBLOCK;
if (oflags & O_SYNC)
fsb.fs_flags |= CLOUDABI_FDFLAG_SYNC;
/* Convert capabilities to CloudABI rights. */
convert_capabilities(&fcaps.fc_rights, fsb.fs_filetype,
&fsb.fs_rights_base, &fsb.fs_rights_inheriting);
filecaps_free(&fcaps);
return (copyout(&fsb, (void *)uap->buf, sizeof(fsb)));
}
/* Converts CloudABI rights to a set of Capsicum capabilities. */
int
cloudabi_convert_rights(cloudabi_rights_t in, cap_rights_t *out)
{
cap_rights_init(out);
#define MAPPING(cloudabi, ...) do { \
if (in & (cloudabi)) { \
cap_rights_set(out, ##__VA_ARGS__); \
in &= ~(cloudabi); \
} \
} while (0);
RIGHTS_MAPPINGS
#undef MAPPING
if (in != 0)
return (ENOTCAPABLE);
return (0);
}
int
cloudabi_sys_fd_stat_put(struct thread *td,
struct cloudabi_sys_fd_stat_put_args *uap)
{
cloudabi_fdstat_t fsb;
cap_rights_t rights;
int error, oflags;
error = copyin(uap->buf, &fsb, sizeof(fsb));
if (error != 0)
return (error);
if (uap->flags == CLOUDABI_FDSTAT_FLAGS) {
/* Convert flags. */
oflags = 0;
if (fsb.fs_flags & CLOUDABI_FDFLAG_APPEND)
oflags |= O_APPEND;
if (fsb.fs_flags & CLOUDABI_FDFLAG_NONBLOCK)
oflags |= O_NONBLOCK;
if (fsb.fs_flags & (CLOUDABI_FDFLAG_SYNC |
CLOUDABI_FDFLAG_DSYNC | CLOUDABI_FDFLAG_RSYNC))
oflags |= O_SYNC;
return (kern_fcntl(td, uap->fd, F_SETFL, oflags));
} else if (uap->flags == CLOUDABI_FDSTAT_RIGHTS) {
/* Convert rights. */
error = cloudabi_convert_rights(
fsb.fs_rights_base | fsb.fs_rights_inheriting, &rights);
if (error != 0)
return (error);
return (kern_cap_rights_limit(td, uap->fd, &rights));
}
return (EINVAL);
}
int
cloudabi_sys_fd_sync(struct thread *td, struct cloudabi_sys_fd_sync_args *uap)
{
return (kern_fsync(td, uap->fd, true));
}