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freebsd-dev/sys/compat/cloudabi/cloudabi_fd.c
Ed Schouten 4e1847781b Import the latest CloudABI definitions, version 0.16. 
The most important change in this release is the removal of the
poll_fd() system call; CloudABI's equivalent of kevent(). Though I think
that kqueue is a lot saner than many of its alternatives, our
experience is that emulating this system call on other systems
accurately isn't easy. It has become a complex API, even though I'm not
convinced this complexity is needed. This is why we've decided to take a
different approach, by looking one layer up.

We're currently adding an event loop to CloudABI's C library that is API
compatible with libuv (except when incompatible with Capsicum).
Initially, this event loop will be built on top of plain inefficient
poll() calls. Only after this is finished, we'll work our way backwards
and design a new set of system calls to optimize it.

Interesting challenges will include integrating asynchronous I/O into
such a system call API. libuv currently doesn't aio(4) on Linux/BSD, due
to it being unreliable and having undesired semantics.

Obtained from:	https://github.com/NuxiNL/cloudabi
2017-10-18 19:22:53 +00:00

474 lines
14 KiB
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/*-
* 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/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, 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 = {};
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));
}
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