net/can/can_socketcan.c - qemu - Git at Google

 /*
  * 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/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>

 #ifndef DEBUG_CAN
 #define DEBUG_CAN 0
 #endif /*DEBUG_CAN*/

 #define TYPE_CAN_HOST_SOCKETCAN "can-host-socketcan"
 #define CAN_HOST_SOCKETCAN(obj) \
      OBJECT_CHECK(CanHostSocketCAN, (obj), TYPE_CAN_HOST_SOCKETCAN)

 #define CAN_READ_BUF_LEN  5
 typedef 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;
 } CanHostSocketCAN;

 /* 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;

     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();
 }

 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;
     }

     can_bus_client_send(&ch->bus_client, c->buf, 1);

     if (DEBUG_CAN) {
         can_host_socketcan_display_msg(c->buf);
     }
 }

 static int can_host_socketcan_can_receive(CanBusClientState *client)
 {
     return 1;
 }

 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 = sizeof(qemu_can_frame);
     int res;

     if (c->fd < 0) {
         return -1;
     }

     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 */
     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);
     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;

     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,
                                   &error_abort);
     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);
	/*
	* 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/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>

	#ifndef DEBUG_CAN
	#define DEBUG_CAN 0
	#endif /DEBUG_CAN/

	#define TYPE_CAN_HOST_SOCKETCAN "can-host-socketcan"
	#define CAN_HOST_SOCKETCAN(obj) \
	OBJECT_CHECK(CanHostSocketCAN, (obj), TYPE_CAN_HOST_SOCKETCAN)

	#define CAN_READ_BUF_LEN 5
	typedef 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;
	} CanHostSocketCAN;

	/* 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;

	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();
	}

	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;
	}

	can_bus_client_send(&ch->bus_client, c->buf, 1);

	if (DEBUG_CAN) {
	can_host_socketcan_display_msg(c->buf);
	}
	}

	static int can_host_socketcan_can_receive(CanBusClientState *client)
	{
	return 1;
	}

	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 = sizeof(qemu_can_frame);
	int res;

	if (c->fd < 0) {
	return -1;
	}

	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 */
	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);
	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;

	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,
	&error_abort);
	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);