/*
* CAN c support to connect to the Linux host SocketCAN interfaces
*
* Copyright (c) 2013-2014 Jin Yang
* Copyright (c) 2014-2018 Pavel Pisa
*
* Initial development supported by Google GSoC 2013 from RTEMS project slot
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
#include "qemu/osdep.h"
#include "qemu/log.h"
#include "qemu/main-loop.h"
#include "qemu/module.h"
#include "qapi/error.h"
#include "chardev/char.h"
#include "qemu/sockets.h"
#include "qemu/error-report.h"
#include "net/can_emu.h"
#include "net/can_host.h"
#include <sys/ioctl.h>
#include <net/if.h>
#include <linux/can.h>
#include <linux/can/raw.h>
#include "qom/object.h"
#ifndef DEBUG_CAN
#define DEBUG_CAN 0
#endif /*DEBUG_CAN*/
#define TYPE_CAN_HOST_SOCKETCAN "can-host-socketcan"
OBJECT_DECLARE_SIMPLE_TYPE(CanHostSocketCAN, CAN_HOST_SOCKETCAN)
#define CAN_READ_BUF_LEN 5
struct CanHostSocketCAN {
CanHostState parent;
char *ifname;
qemu_can_filter *rfilter;
int rfilter_num;
can_err_mask_t err_mask;
qemu_can_frame buf[CAN_READ_BUF_LEN];
int bufcnt;
int bufptr;
int fd;
};
/* Check that QEMU and Linux kernel flags encoding and structure matches */
QEMU_BUILD_BUG_ON(QEMU_CAN_EFF_FLAG != CAN_EFF_FLAG);
QEMU_BUILD_BUG_ON(QEMU_CAN_RTR_FLAG != CAN_RTR_FLAG);
QEMU_BUILD_BUG_ON(QEMU_CAN_ERR_FLAG != CAN_ERR_FLAG);
QEMU_BUILD_BUG_ON(QEMU_CAN_INV_FILTER != CAN_INV_FILTER);
QEMU_BUILD_BUG_ON(offsetof(qemu_can_frame, data)
!= offsetof(struct can_frame, data));
static void can_host_socketcan_display_msg(struct qemu_can_frame *msg)
{
int i;
FILE *logfile = qemu_log_lock();
qemu_log("[cansocketcan]: %03X [%01d] %s %s",
msg->can_id & QEMU_CAN_EFF_MASK,
msg->can_dlc,
msg->can_id & QEMU_CAN_EFF_FLAG ? "EFF" : "SFF",
msg->can_id & QEMU_CAN_RTR_FLAG ? "RTR" : "DAT");
for (i = 0; i < msg->can_dlc; i++) {
qemu_log(" %02X", msg->data[i]);
}
qemu_log("\n");
qemu_log_flush();
qemu_log_unlock(logfile);
}
static void can_host_socketcan_read(void *opaque)
{
CanHostSocketCAN *c = opaque;
CanHostState *ch = CAN_HOST(c);
/* CAN_READ_BUF_LEN for multiple messages syscall is possible for future */
c->bufcnt = read(c->fd, c->buf, sizeof(qemu_can_frame));
if (c->bufcnt < 0) {
warn_report("CAN bus host read failed (%s)", strerror(errno));
return;
}
if (!ch->bus_client.fd_mode) {
c->buf[0].flags = 0;
} else {
if (c->bufcnt > CAN_MTU) {
c->buf[0].flags |= QEMU_CAN_FRMF_TYPE_FD;
}
}
can_bus_client_send(&ch->bus_client, c->buf, 1);
if (DEBUG_CAN) {
can_host_socketcan_display_msg(c->buf);
}
}
static bool can_host_socketcan_can_receive(CanBusClientState *client)
{
return true;
}
static ssize_t can_host_socketcan_receive(CanBusClientState *client,
const qemu_can_frame *frames, size_t frames_cnt)
{
CanHostState *ch = container_of(client, CanHostState, bus_client);
CanHostSocketCAN *c = CAN_HOST_SOCKETCAN(ch);
size_t len;
int res;
if (c->fd < 0) {
return -1;
}
if (frames->flags & QEMU_CAN_FRMF_TYPE_FD) {
if (!ch->bus_client.fd_mode) {
return 0;
}
len = CANFD_MTU;
} else {
len = CAN_MTU;
}
res = write(c->fd, frames, len);
if (!res) {
warn_report("[cansocketcan]: write message to host returns zero");
return -1;
}
if (res != len) {
if (res < 0) {
warn_report("[cansocketcan]: write to host failed (%s)",
strerror(errno));
} else {
warn_report("[cansocketcan]: write to host truncated");
}
return -1;
}
return 1;
}
static void can_host_socketcan_disconnect(CanHostState *ch)
{
CanHostSocketCAN *c = CAN_HOST_SOCKETCAN(ch);
if (c->fd >= 0) {
qemu_set_fd_handler(c->fd, NULL, NULL, c);
close(c->fd);
c->fd = -1;
}
g_free(c->rfilter);
c->rfilter = NULL;
c->rfilter_num = 0;
}
static CanBusClientInfo can_host_socketcan_bus_client_info = {
.can_receive = can_host_socketcan_can_receive,
.receive = can_host_socketcan_receive,
};
static void can_host_socketcan_connect(CanHostState *ch, Error **errp)
{
CanHostSocketCAN *c = CAN_HOST_SOCKETCAN(ch);
int s; /* can raw socket */
int mtu;
int enable_canfd = 1;
struct sockaddr_can addr;
struct ifreq ifr;
/* open socket */
s = qemu_socket(PF_CAN, SOCK_RAW, CAN_RAW);
if (s < 0) {
error_setg_errno(errp, errno, "failed to create CAN_RAW socket");
return;
}
addr.can_family = AF_CAN;
memset(&ifr.ifr_name, 0, sizeof(ifr.ifr_name));
strcpy(ifr.ifr_name, c->ifname);
/* check if the frame fits into the CAN netdevice */
if (ioctl(s, SIOCGIFINDEX, &ifr) < 0) {
error_setg_errno(errp, errno,
"SocketCAN host interface %s not available",
c->ifname);
goto fail;
}
addr.can_ifindex = ifr.ifr_ifindex;
if (ioctl(s, SIOCGIFMTU, &ifr) < 0) {
error_setg_errno(errp, errno,
"SocketCAN host interface %s SIOCGIFMTU failed",
c->ifname);
goto fail;
}
mtu = ifr.ifr_mtu;
if (mtu >= CANFD_MTU) {
/* interface is ok - try to switch the socket into CAN FD mode */
if (setsockopt(s, SOL_CAN_RAW, CAN_RAW_FD_FRAMES,
&enable_canfd, sizeof(enable_canfd))) {
warn_report("SocketCAN host interface %s enabling CAN FD failed",
c->ifname);
} else {
c->parent.bus_client.fd_mode = true;
}
}
c->err_mask = 0xffffffff; /* Receive error frame. */
setsockopt(s, SOL_CAN_RAW, CAN_RAW_ERR_FILTER,
&c->err_mask, sizeof(c->err_mask));
c->rfilter_num = 1;
c->rfilter = g_new(struct qemu_can_filter, c->rfilter_num);
/* Receive all data frame. If |= CAN_INV_FILTER no data. */
c->rfilter[0].can_id = 0;
c->rfilter[0].can_mask = 0;
c->rfilter[0].can_mask &= ~CAN_ERR_FLAG;
setsockopt(s, SOL_CAN_RAW, CAN_RAW_FILTER, c->rfilter,
c->rfilter_num * sizeof(struct qemu_can_filter));
if (bind(s, (struct sockaddr *)&addr, sizeof(addr)) < 0) {
error_setg_errno(errp, errno, "failed to bind to host interface %s",
c->ifname);
goto fail;
}
c->fd = s;
ch->bus_client.info = &can_host_socketcan_bus_client_info;
qemu_set_fd_handler(c->fd, can_host_socketcan_read, NULL, c);
return;
fail:
close(s);
g_free(c->rfilter);
c->rfilter = NULL;
c->rfilter_num = 0;
}
static char *can_host_socketcan_get_if(Object *obj, Error **errp)
{
CanHostSocketCAN *c = CAN_HOST_SOCKETCAN(obj);
return g_strdup(c->ifname);
}
static void can_host_socketcan_set_if(Object *obj, const char *value,
Error **errp)
{
CanHostSocketCAN *c = CAN_HOST_SOCKETCAN(obj);
struct ifreq ifr;
if (strlen(value) >= sizeof(ifr.ifr_name)) {
error_setg(errp, "CAN interface name longer than %zd characters",
sizeof(ifr.ifr_name) - 1);
return;
}
if (c->fd != -1) {
error_setg(errp, "CAN interface already connected");
return;
}
g_free(c->ifname);
c->ifname = g_strdup(value);
}
static void can_host_socketcan_instance_init(Object *obj)
{
CanHostSocketCAN *c = CAN_HOST_SOCKETCAN(obj);
c->fd = -1;
}
static void can_host_socketcan_class_init(ObjectClass *klass,
void *class_data G_GNUC_UNUSED)
{
CanHostClass *chc = CAN_HOST_CLASS(klass);
object_class_property_add_str(klass, "if",
can_host_socketcan_get_if,
can_host_socketcan_set_if);
chc->connect = can_host_socketcan_connect;
chc->disconnect = can_host_socketcan_disconnect;
}
static const TypeInfo can_host_socketcan_info = {
.parent = TYPE_CAN_HOST,
.name = TYPE_CAN_HOST_SOCKETCAN,
.instance_size = sizeof(CanHostSocketCAN),
.instance_init = can_host_socketcan_instance_init,
.class_init = can_host_socketcan_class_init,
};
static void can_host_register_types(void)
{
type_register_static(&can_host_socketcan_info);
}
type_init(can_host_register_types);
