/*-
* Copyright (c) 2010-2022 Hans Petter Selasky. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* 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 <stdio.h>
#include <stdint.h>
#include <pthread.h>
#include <signal.h>
#include <unistd.h>
#include <string.h>
#include <errno.h>
#include <stdlib.h>
#include <stdarg.h>
#include <sys/types.h>
#include <sys/queue.h>
#include <sys/fcntl.h>
#include <sys/mman.h>
#include <sys/param.h>
#include <fs/cuse/cuse_ioctl.h>
#include "cuse.h"
int cuse_debug_level;
#ifdef HAVE_DEBUG
static const char *cuse_cmd_str(int cmd);
#define DPRINTF(...) do { \
if (cuse_debug_level != 0) \
printf(__VA_ARGS__); \
} while (0)
#else
#define DPRINTF(...) do { } while (0)
#endif
struct cuse_vm_allocation {
uint8_t *ptr;
uint32_t size;
};
struct cuse_dev_entered {
TAILQ_ENTRY(cuse_dev_entered) entry;
pthread_t thread;
void *per_file_handle;
struct cuse_dev *cdev;
int cmd;
int is_local;
int got_signal;
};
struct cuse_dev {
TAILQ_ENTRY(cuse_dev) entry;
const struct cuse_methods *mtod;
void *priv0;
void *priv1;
};
static int f_cuse = -1;
static pthread_mutex_t m_cuse;
static TAILQ_HEAD(, cuse_dev) h_cuse __guarded_by(m_cuse);
static TAILQ_HEAD(, cuse_dev_entered) h_cuse_entered __guarded_by(m_cuse);
static struct cuse_vm_allocation a_cuse[CUSE_ALLOC_UNIT_MAX]
__guarded_by(m_cuse);
#define CUSE_LOCK() \
pthread_mutex_lock(&m_cuse)
#define CUSE_UNLOCK() \
pthread_mutex_unlock(&m_cuse)
int
cuse_init(void)
{
pthread_mutexattr_t attr;
f_cuse = open("/dev/cuse", O_RDWR);
if (f_cuse < 0) {
if (feature_present("cuse") == 0)
return (CUSE_ERR_NOT_LOADED);
else
return (CUSE_ERR_INVALID);
}
pthread_mutexattr_init(&attr);
pthread_mutexattr_settype(&attr, PTHREAD_MUTEX_RECURSIVE);
pthread_mutex_init(&m_cuse, &attr);
TAILQ_INIT(&h_cuse);
TAILQ_INIT(&h_cuse_entered);
return (0);
}
int
cuse_uninit(void)
{
int f;
if (f_cuse < 0)
return (CUSE_ERR_INVALID);
f = f_cuse;
f_cuse = -1;
close(f);
pthread_mutex_destroy(&m_cuse);
memset(a_cuse, 0, sizeof(a_cuse));
return (0);
}
unsigned long
cuse_vmoffset(void *_ptr)
{
uint8_t *ptr_min;
uint8_t *ptr_max;
uint8_t *ptr = _ptr;
unsigned long remainder;
unsigned long n;
CUSE_LOCK();
for (n = remainder = 0; n != CUSE_ALLOC_UNIT_MAX; n++) {
if (a_cuse[n].ptr == NULL)
continue;
ptr_min = a_cuse[n].ptr;
ptr_max = a_cuse[n].ptr + a_cuse[n].size - 1;
if ((ptr >= ptr_min) && (ptr <= ptr_max)) {
remainder = (ptr - ptr_min);
break;
}
}
CUSE_UNLOCK();
return ((n << CUSE_ALLOC_UNIT_SHIFT) + remainder);
}
void *
cuse_vmalloc(unsigned size)
{
struct cuse_alloc_info info;
unsigned long pgsize;
unsigned long x;
unsigned long m;
unsigned long n;
void *ptr;
int error;
/* some sanity checks */
if (f_cuse < 0 || size < 1 || size > CUSE_ALLOC_BYTES_MAX)
return (NULL);
memset(&info, 0, sizeof(info));
pgsize = getpagesize();
info.page_count = howmany(size, pgsize);
/* compute how many units the allocation needs */
m = howmany(size, 1 << CUSE_ALLOC_UNIT_SHIFT);
if (m == 0 || m > CUSE_ALLOC_UNIT_MAX)
return (NULL);
CUSE_LOCK();
for (n = 0; n <= CUSE_ALLOC_UNIT_MAX - m; ) {
if (a_cuse[n].size != 0) {
/* skip to next available unit, depending on allocation size */
n += howmany(a_cuse[n].size, 1 << CUSE_ALLOC_UNIT_SHIFT);
continue;
}
/* check if there are "m" free units ahead */
for (x = 1; x != m; x++) {
if (a_cuse[n + x].size != 0)
break;
}
if (x != m) {
/* skip to next available unit, if any */
n += x + 1;
continue;
}
/* reserve this unit by setting the size to a non-zero value */
a_cuse[n].size = size;
CUSE_UNLOCK();
info.alloc_nr = n;
error = ioctl(f_cuse, CUSE_IOCTL_ALLOC_MEMORY, &info);
if (error == 0) {
ptr = mmap(NULL, info.page_count * pgsize,
PROT_READ | PROT_WRITE,
MAP_SHARED, f_cuse, n << CUSE_ALLOC_UNIT_SHIFT);
if (ptr != MAP_FAILED) {
CUSE_LOCK();
a_cuse[n].ptr = ptr;
CUSE_UNLOCK();
return (ptr); /* success */
}
(void) ioctl(f_cuse, CUSE_IOCTL_FREE_MEMORY, &info);
}
CUSE_LOCK();
a_cuse[n].size = 0;
n++;
}
CUSE_UNLOCK();
return (NULL); /* failure */
}
int
cuse_is_vmalloc_addr(void *ptr)
{
int n;
if (f_cuse < 0 || ptr == NULL)
return (0); /* false */
CUSE_LOCK();
for (n = 0; n != CUSE_ALLOC_UNIT_MAX; n++) {
if (a_cuse[n].ptr == ptr)
break;
}
CUSE_UNLOCK();
return (n != CUSE_ALLOC_UNIT_MAX);
}
void
cuse_vmfree(void *ptr)
{
struct cuse_vm_allocation temp;
struct cuse_alloc_info info;
int error;
int n;
if (f_cuse < 0 || ptr == NULL)
return;
CUSE_LOCK();
for (n = 0; n != CUSE_ALLOC_UNIT_MAX; n++) {
if (a_cuse[n].ptr != ptr)
continue;
temp = a_cuse[n];
CUSE_UNLOCK();
munmap(temp.ptr, temp.size);
memset(&info, 0, sizeof(info));
info.alloc_nr = n;
error = ioctl(f_cuse, CUSE_IOCTL_FREE_MEMORY, &info);
if (error != 0) {
/* ignore any errors */
DPRINTF("Freeing memory failed: %d\n", errno);
}
CUSE_LOCK();
a_cuse[n].ptr = NULL;
a_cuse[n].size = 0;
break;
}
CUSE_UNLOCK();
}
int
cuse_alloc_unit_number_by_id(int *pnum, int id)
{
int error;
if (f_cuse < 0)
return (CUSE_ERR_INVALID);
*pnum = (id & CUSE_ID_MASK);
error = ioctl(f_cuse, CUSE_IOCTL_ALLOC_UNIT_BY_ID, pnum);
if (error)
return (CUSE_ERR_NO_MEMORY);
return (0);
}
int
cuse_free_unit_number_by_id(int num, int id)
{
int error;
if (f_cuse < 0)
return (CUSE_ERR_INVALID);
if (num != -1 || id != -1)
num = (id & CUSE_ID_MASK) | (num & 0xFF);
error = ioctl(f_cuse, CUSE_IOCTL_FREE_UNIT_BY_ID, &num);
if (error)
return (CUSE_ERR_NO_MEMORY);
return (0);
}
int
cuse_alloc_unit_number(int *pnum)
{
int error;
if (f_cuse < 0)
return (CUSE_ERR_INVALID);
error = ioctl(f_cuse, CUSE_IOCTL_ALLOC_UNIT, pnum);
if (error)
return (CUSE_ERR_NO_MEMORY);
return (0);
}
int
cuse_free_unit_number(int num)
{
int error;
if (f_cuse < 0)
return (CUSE_ERR_INVALID);
error = ioctl(f_cuse, CUSE_IOCTL_FREE_UNIT, &num);
if (error)
return (CUSE_ERR_NO_MEMORY);
return (0);
}
struct cuse_dev *
cuse_dev_create(const struct cuse_methods *mtod, void *priv0, void *priv1,
uid_t _uid, gid_t _gid, int _perms, const char *_fmt,...)
{
struct cuse_create_dev info;
struct cuse_dev *cdev;
va_list args;
int error;
if (f_cuse < 0)
return (NULL);
cdev = malloc(sizeof(*cdev));
if (cdev == NULL)
return (NULL);
memset(cdev, 0, sizeof(*cdev));
cdev->mtod = mtod;
cdev->priv0 = priv0;
cdev->priv1 = priv1;
memset(&info, 0, sizeof(info));
info.dev = cdev;
info.user_id = _uid;
info.group_id = _gid;
info.permissions = _perms;
va_start(args, _fmt);
vsnprintf(info.devname, sizeof(info.devname), _fmt, args);
va_end(args);
error = ioctl(f_cuse, CUSE_IOCTL_CREATE_DEV, &info);
if (error) {
free(cdev);
return (NULL);
}
CUSE_LOCK();
TAILQ_INSERT_TAIL(&h_cuse, cdev, entry);
CUSE_UNLOCK();
return (cdev);
}
void
cuse_dev_destroy(struct cuse_dev *cdev)
{
int error;
if (f_cuse < 0)
return;
CUSE_LOCK();
TAILQ_REMOVE(&h_cuse, cdev, entry);
CUSE_UNLOCK();
error = ioctl(f_cuse, CUSE_IOCTL_DESTROY_DEV, &cdev);
if (error)
return;
free(cdev);
}
void *
cuse_dev_get_priv0(struct cuse_dev *cdev)
{
return (cdev->priv0);
}
void *
cuse_dev_get_priv1(struct cuse_dev *cdev)
{
return (cdev->priv1);
}
void
cuse_dev_set_priv0(struct cuse_dev *cdev, void *priv)
{
cdev->priv0 = priv;
}
void
cuse_dev_set_priv1(struct cuse_dev *cdev, void *priv)
{
cdev->priv1 = priv;
}
int
cuse_wait_and_process(void)
{
pthread_t curr = pthread_self();
struct cuse_dev_entered *pe;
struct cuse_dev_entered enter;
struct cuse_command info;
struct cuse_dev *cdev;
int error;
if (f_cuse < 0)
return (CUSE_ERR_INVALID);
error = ioctl(f_cuse, CUSE_IOCTL_GET_COMMAND, &info);
if (error)
return (CUSE_ERR_OTHER);
cdev = info.dev;
CUSE_LOCK();
enter.thread = curr;
enter.per_file_handle = (void *)info.per_file_handle;
enter.cmd = info.command;
enter.is_local = 0;
enter.got_signal = 0;
enter.cdev = cdev;
TAILQ_INSERT_TAIL(&h_cuse_entered, &enter, entry);
CUSE_UNLOCK();
DPRINTF("cuse: Command = %d = %s, flags = %d, arg = 0x%08x, ptr = 0x%08x\n",
(int)info.command, cuse_cmd_str(info.command), (int)info.fflags,
(int)info.argument, (int)info.data_pointer);
switch (info.command) {
case CUSE_CMD_OPEN:
if (cdev->mtod->cm_open != NULL)
error = (cdev->mtod->cm_open) (cdev, (int)info.fflags);
else
error = 0;
break;
case CUSE_CMD_CLOSE:
/* wait for other threads to stop */
while (1) {
error = 0;
CUSE_LOCK();
TAILQ_FOREACH(pe, &h_cuse_entered, entry) {
if (pe->cdev != cdev)
continue;
if (pe->thread == curr)
continue;
if (pe->per_file_handle !=
enter.per_file_handle)
continue;
pe->got_signal = 1;
pthread_kill(pe->thread, SIGHUP);
error = CUSE_ERR_BUSY;
}
CUSE_UNLOCK();
if (error == 0)
break;
else
usleep(10000);
}
if (cdev->mtod->cm_close != NULL)
error = (cdev->mtod->cm_close) (cdev, (int)info.fflags);
else
error = 0;
break;
case CUSE_CMD_READ:
if (cdev->mtod->cm_read != NULL) {
error = (cdev->mtod->cm_read) (cdev, (int)info.fflags,
(void *)info.data_pointer, (int)info.argument);
} else {
error = CUSE_ERR_INVALID;
}
break;
case CUSE_CMD_WRITE:
if (cdev->mtod->cm_write != NULL) {
error = (cdev->mtod->cm_write) (cdev, (int)info.fflags,
(void *)info.data_pointer, (int)info.argument);
} else {
error = CUSE_ERR_INVALID;
}
break;
case CUSE_CMD_IOCTL:
if (cdev->mtod->cm_ioctl != NULL) {
error = (cdev->mtod->cm_ioctl) (cdev, (int)info.fflags,
(unsigned int)info.argument, (void *)info.data_pointer);
} else {
error = CUSE_ERR_INVALID;
}
break;
case CUSE_CMD_POLL:
if (cdev->mtod->cm_poll != NULL) {
error = (cdev->mtod->cm_poll) (cdev, (int)info.fflags,
(int)info.argument);
} else {
error = CUSE_POLL_ERROR;
}
break;
case CUSE_CMD_SIGNAL:
CUSE_LOCK();
TAILQ_FOREACH(pe, &h_cuse_entered, entry) {
if (pe->cdev != cdev)
continue;
if (pe->thread == curr)
continue;
if (pe->per_file_handle !=
enter.per_file_handle)
continue;
pe->got_signal = 1;
pthread_kill(pe->thread, SIGHUP);
}
CUSE_UNLOCK();
break;
default:
error = CUSE_ERR_INVALID;
break;
}
DPRINTF("cuse: Command error = %d for %s\n",
error, cuse_cmd_str(info.command));
CUSE_LOCK();
TAILQ_REMOVE(&h_cuse_entered, &enter, entry);
CUSE_UNLOCK();
/* we ignore any sync command failures */
ioctl(f_cuse, CUSE_IOCTL_SYNC_COMMAND, &error);
return (0);
}
static struct cuse_dev_entered *
cuse_dev_get_entered(void)
{
struct cuse_dev_entered *pe;
pthread_t curr = pthread_self();
CUSE_LOCK();
TAILQ_FOREACH(pe, &h_cuse_entered, entry) {
if (pe->thread == curr)
break;
}
CUSE_UNLOCK();
return (pe);
}
void
cuse_dev_set_per_file_handle(struct cuse_dev *cdev, void *handle)
{
struct cuse_dev_entered *pe;
pe = cuse_dev_get_entered();
if (pe == NULL || pe->cdev != cdev)
return;
pe->per_file_handle = handle;
ioctl(f_cuse, CUSE_IOCTL_SET_PFH, &handle);
}
void *
cuse_dev_get_per_file_handle(struct cuse_dev *cdev)
{
struct cuse_dev_entered *pe;
pe = cuse_dev_get_entered();
if (pe == NULL || pe->cdev != cdev)
return (NULL);
return (pe->per_file_handle);
}
void
cuse_set_local(int val)
{
struct cuse_dev_entered *pe;
pe = cuse_dev_get_entered();
if (pe == NULL)
return;
pe->is_local = val;
}
#ifdef HAVE_DEBUG
static const char *
cuse_cmd_str(int cmd)
{
static const char *str[CUSE_CMD_MAX] = {
[CUSE_CMD_NONE] = "none",
[CUSE_CMD_OPEN] = "open",
[CUSE_CMD_CLOSE] = "close",
[CUSE_CMD_READ] = "read",
[CUSE_CMD_WRITE] = "write",
[CUSE_CMD_IOCTL] = "ioctl",
[CUSE_CMD_POLL] = "poll",
[CUSE_CMD_SIGNAL] = "signal",
[CUSE_CMD_SYNC] = "sync",
};
if ((cmd >= 0) && (cmd < CUSE_CMD_MAX) &&
(str[cmd] != NULL))
return (str[cmd]);
else
return ("unknown");
}
#endif
int
cuse_get_local(void)
{
struct cuse_dev_entered *pe;
pe = cuse_dev_get_entered();
if (pe == NULL)
return (0);
return (pe->is_local);
}
int
cuse_copy_out(const void *src, void *user_dst, int len)
{
struct cuse_data_chunk info;
struct cuse_dev_entered *pe;
int error;
if ((f_cuse < 0) || (len < 0))
return (CUSE_ERR_INVALID);
pe = cuse_dev_get_entered();
if (pe == NULL)
return (CUSE_ERR_INVALID);
DPRINTF("cuse: copy_out(%p,%p,%d), cmd = %d = %s\n",
src, user_dst, len, pe->cmd, cuse_cmd_str(pe->cmd));
if (pe->is_local) {
memcpy(user_dst, src, len);
} else {
info.local_ptr = (uintptr_t)src;
info.peer_ptr = (uintptr_t)user_dst;
info.length = len;
error = ioctl(f_cuse, CUSE_IOCTL_WRITE_DATA, &info);
if (error) {
DPRINTF("cuse: copy_out() error = %d\n", errno);
return (CUSE_ERR_FAULT);
}
}
return (0);
}
int
cuse_copy_in(const void *user_src, void *dst, int len)
{
struct cuse_data_chunk info;
struct cuse_dev_entered *pe;
int error;
if ((f_cuse < 0) || (len < 0))
return (CUSE_ERR_INVALID);
pe = cuse_dev_get_entered();
if (pe == NULL)
return (CUSE_ERR_INVALID);
DPRINTF("cuse: copy_in(%p,%p,%d), cmd = %d = %s\n",
user_src, dst, len, pe->cmd, cuse_cmd_str(pe->cmd));
if (pe->is_local) {
memcpy(dst, user_src, len);
} else {
info.local_ptr = (uintptr_t)dst;
info.peer_ptr = (uintptr_t)user_src;
info.length = len;
error = ioctl(f_cuse, CUSE_IOCTL_READ_DATA, &info);
if (error) {
DPRINTF("cuse: copy_in() error = %d\n", errno);
return (CUSE_ERR_FAULT);
}
}
return (0);
}
struct cuse_dev *
cuse_dev_get_current(int *pcmd)
{
struct cuse_dev_entered *pe;
pe = cuse_dev_get_entered();
if (pe == NULL) {
if (pcmd != NULL)
*pcmd = 0;
return (NULL);
}
if (pcmd != NULL)
*pcmd = pe->cmd;
return (pe->cdev);
}
int
cuse_got_peer_signal(void)
{
struct cuse_dev_entered *pe;
pe = cuse_dev_get_entered();
if (pe == NULL)
return (CUSE_ERR_INVALID);
if (pe->got_signal)
return (0);
return (CUSE_ERR_OTHER);
}
void
cuse_poll_wakeup(void)
{
int error = 0;
if (f_cuse < 0)
return;
ioctl(f_cuse, CUSE_IOCTL_SELWAKEUP, &error);
}
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