1 /*
2 * CAN c support to connect to the Linux host SocketCAN interfaces
3 *
4 * Copyright (c) 2013-2014 Jin Yang
5 * Copyright (c) 2014-2018 Pavel Pisa
6 *
7 * Initial development supported by Google GSoC 2013 from RTEMS project slot
8 *
9 * Permission is hereby granted, free of charge, to any person obtaining a copy
10 * of this software and associated documentation files (the "Software"), to deal
11 * in the Software without restriction, including without limitation the rights
12 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
13 * copies of the Software, and to permit persons to whom the Software is
14 * furnished to do so, subject to the following conditions:
15 *
16 * The above copyright notice and this permission notice shall be included in
17 * all copies or substantial portions of the Software.
18 *
19 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
20 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
21 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
22 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
23 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
24 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
25 * THE SOFTWARE.
26 */
27
28 #include "qemu/osdep.h"
29 #include "qemu/log.h"
30 #include "qemu/main-loop.h"
31 #include "qemu/module.h"
32 #include "qapi/error.h"
33 #include "chardev/char.h"
34 #include "qemu/sockets.h"
35 #include "qemu/error-report.h"
36 #include "net/can_emu.h"
37 #include "net/can_host.h"
38
39 #include <sys/ioctl.h>
40 #include <net/if.h>
41 #include <linux/can.h>
42 #include <linux/can/raw.h>
43 #include "qom/object.h"
44
45 #ifndef DEBUG_CAN
46 #define DEBUG_CAN 0
47 #endif /*DEBUG_CAN*/
48
49 #define TYPE_CAN_HOST_SOCKETCAN "can-host-socketcan"
50 OBJECT_DECLARE_SIMPLE_TYPE(CanHostSocketCAN, CAN_HOST_SOCKETCAN)
51
52 #define CAN_READ_BUF_LEN 5
53 struct CanHostSocketCAN {
54 CanHostState parent;
55 char *ifname;
56
57 qemu_can_filter *rfilter;
58 int rfilter_num;
59 can_err_mask_t err_mask;
60
61 qemu_can_frame buf[CAN_READ_BUF_LEN];
62 int bufcnt;
63 int bufptr;
64
65 int fd;
66 };
67
68 /* Check that QEMU and Linux kernel flags encoding and structure matches */
69 QEMU_BUILD_BUG_ON(QEMU_CAN_EFF_FLAG != CAN_EFF_FLAG);
70 QEMU_BUILD_BUG_ON(QEMU_CAN_RTR_FLAG != CAN_RTR_FLAG);
71 QEMU_BUILD_BUG_ON(QEMU_CAN_ERR_FLAG != CAN_ERR_FLAG);
72 QEMU_BUILD_BUG_ON(QEMU_CAN_INV_FILTER != CAN_INV_FILTER);
73 QEMU_BUILD_BUG_ON(offsetof(qemu_can_frame, data)
74 != offsetof(struct can_frame, data));
75
can_host_socketcan_display_msg(struct qemu_can_frame * msg)76 static void can_host_socketcan_display_msg(struct qemu_can_frame *msg)
77 {
78 int i;
79 FILE *logfile = qemu_log_trylock();
80
81 if (logfile) {
82 fprintf(logfile, "[cansocketcan]: %03X [%01d] %s %s",
83 msg->can_id & QEMU_CAN_EFF_MASK,
84 msg->can_dlc,
85 msg->can_id & QEMU_CAN_EFF_FLAG ? "EFF" : "SFF",
86 msg->can_id & QEMU_CAN_RTR_FLAG ? "RTR" : "DAT");
87
88 for (i = 0; i < msg->can_dlc; i++) {
89 fprintf(logfile, " %02X", msg->data[i]);
90 }
91 fprintf(logfile, "\n");
92 qemu_log_unlock(logfile);
93 }
94 }
95
can_host_socketcan_read(void * opaque)96 static void can_host_socketcan_read(void *opaque)
97 {
98 CanHostSocketCAN *c = opaque;
99 CanHostState *ch = CAN_HOST(c);
100
101 /* CAN_READ_BUF_LEN for multiple messages syscall is possible for future */
102 c->bufcnt = read(c->fd, c->buf, sizeof(qemu_can_frame));
103 if (c->bufcnt < 0) {
104 warn_report("CAN bus host read failed (%s)", strerror(errno));
105 return;
106 }
107
108 if (!ch->bus_client.fd_mode) {
109 c->buf[0].flags = 0;
110 } else {
111 if (c->bufcnt > CAN_MTU) {
112 c->buf[0].flags |= QEMU_CAN_FRMF_TYPE_FD;
113 }
114 }
115
116 can_bus_client_send(&ch->bus_client, c->buf, 1);
117
118 if (DEBUG_CAN) {
119 can_host_socketcan_display_msg(c->buf);
120 }
121 }
122
can_host_socketcan_can_receive(CanBusClientState * client)123 static bool can_host_socketcan_can_receive(CanBusClientState *client)
124 {
125 return true;
126 }
127
can_host_socketcan_receive(CanBusClientState * client,const qemu_can_frame * frames,size_t frames_cnt)128 static ssize_t can_host_socketcan_receive(CanBusClientState *client,
129 const qemu_can_frame *frames, size_t frames_cnt)
130 {
131 CanHostState *ch = container_of(client, CanHostState, bus_client);
132 CanHostSocketCAN *c = CAN_HOST_SOCKETCAN(ch);
133
134 size_t len;
135 int res;
136
137 if (c->fd < 0) {
138 return -1;
139 }
140 if (frames->flags & QEMU_CAN_FRMF_TYPE_FD) {
141 if (!ch->bus_client.fd_mode) {
142 return 0;
143 }
144 len = CANFD_MTU;
145 } else {
146 len = CAN_MTU;
147
148 }
149
150 res = write(c->fd, frames, len);
151
152 if (!res) {
153 warn_report("[cansocketcan]: write message to host returns zero");
154 return -1;
155 }
156
157 if (res != len) {
158 if (res < 0) {
159 warn_report("[cansocketcan]: write to host failed (%s)",
160 strerror(errno));
161 } else {
162 warn_report("[cansocketcan]: write to host truncated");
163 }
164 return -1;
165 }
166
167 return 1;
168 }
169
can_host_socketcan_disconnect(CanHostState * ch)170 static void can_host_socketcan_disconnect(CanHostState *ch)
171 {
172 CanHostSocketCAN *c = CAN_HOST_SOCKETCAN(ch);
173
174 if (c->fd >= 0) {
175 qemu_set_fd_handler(c->fd, NULL, NULL, c);
176 close(c->fd);
177 c->fd = -1;
178 }
179
180 g_free(c->rfilter);
181 c->rfilter = NULL;
182 c->rfilter_num = 0;
183 }
184
185 static CanBusClientInfo can_host_socketcan_bus_client_info = {
186 .can_receive = can_host_socketcan_can_receive,
187 .receive = can_host_socketcan_receive,
188 };
189
can_host_socketcan_connect(CanHostState * ch,Error ** errp)190 static void can_host_socketcan_connect(CanHostState *ch, Error **errp)
191 {
192 CanHostSocketCAN *c = CAN_HOST_SOCKETCAN(ch);
193 int s; /* can raw socket */
194 int mtu;
195 int enable_canfd = 1;
196 struct sockaddr_can addr;
197 struct ifreq ifr;
198
199 if (!c->ifname) {
200 error_setg(errp, "'if' property not set");
201 return;
202 }
203
204 /* open socket */
205 s = qemu_socket(PF_CAN, SOCK_RAW, CAN_RAW);
206 if (s < 0) {
207 error_setg_errno(errp, errno, "failed to create CAN_RAW socket");
208 return;
209 }
210
211 addr.can_family = AF_CAN;
212 memset(&ifr.ifr_name, 0, sizeof(ifr.ifr_name));
213 strcpy(ifr.ifr_name, c->ifname);
214 /* check if the frame fits into the CAN netdevice */
215 if (ioctl(s, SIOCGIFINDEX, &ifr) < 0) {
216 error_setg_errno(errp, errno,
217 "SocketCAN host interface %s not available",
218 c->ifname);
219 goto fail;
220 }
221 addr.can_ifindex = ifr.ifr_ifindex;
222
223 if (ioctl(s, SIOCGIFMTU, &ifr) < 0) {
224 error_setg_errno(errp, errno,
225 "SocketCAN host interface %s SIOCGIFMTU failed",
226 c->ifname);
227 goto fail;
228 }
229 mtu = ifr.ifr_mtu;
230
231 if (mtu >= CANFD_MTU) {
232 /* interface is ok - try to switch the socket into CAN FD mode */
233 if (setsockopt(s, SOL_CAN_RAW, CAN_RAW_FD_FRAMES,
234 &enable_canfd, sizeof(enable_canfd))) {
235 warn_report("SocketCAN host interface %s enabling CAN FD failed",
236 c->ifname);
237 } else {
238 c->parent.bus_client.fd_mode = true;
239 }
240 }
241
242 c->err_mask = 0xffffffff; /* Receive error frame. */
243 setsockopt(s, SOL_CAN_RAW, CAN_RAW_ERR_FILTER,
244 &c->err_mask, sizeof(c->err_mask));
245
246 c->rfilter_num = 1;
247 c->rfilter = g_new(struct qemu_can_filter, c->rfilter_num);
248
249 /* Receive all data frame. If |= CAN_INV_FILTER no data. */
250 c->rfilter[0].can_id = 0;
251 c->rfilter[0].can_mask = 0;
252 c->rfilter[0].can_mask &= ~CAN_ERR_FLAG;
253
254 setsockopt(s, SOL_CAN_RAW, CAN_RAW_FILTER, c->rfilter,
255 c->rfilter_num * sizeof(struct qemu_can_filter));
256
257 if (bind(s, (struct sockaddr *)&addr, sizeof(addr)) < 0) {
258 error_setg_errno(errp, errno, "failed to bind to host interface %s",
259 c->ifname);
260 goto fail;
261 }
262
263 c->fd = s;
264 ch->bus_client.info = &can_host_socketcan_bus_client_info;
265 qemu_set_fd_handler(c->fd, can_host_socketcan_read, NULL, c);
266 return;
267
268 fail:
269 close(s);
270 g_free(c->rfilter);
271 c->rfilter = NULL;
272 c->rfilter_num = 0;
273 }
274
can_host_socketcan_get_if(Object * obj,Error ** errp)275 static char *can_host_socketcan_get_if(Object *obj, Error **errp)
276 {
277 CanHostSocketCAN *c = CAN_HOST_SOCKETCAN(obj);
278
279 return g_strdup(c->ifname);
280 }
281
can_host_socketcan_set_if(Object * obj,const char * value,Error ** errp)282 static void can_host_socketcan_set_if(Object *obj, const char *value,
283 Error **errp)
284 {
285 CanHostSocketCAN *c = CAN_HOST_SOCKETCAN(obj);
286 struct ifreq ifr;
287
288 if (strlen(value) >= sizeof(ifr.ifr_name)) {
289 error_setg(errp, "CAN interface name longer than %zd characters",
290 sizeof(ifr.ifr_name) - 1);
291 return;
292 }
293
294 if (c->fd != -1) {
295 error_setg(errp, "CAN interface already connected");
296 return;
297 }
298
299 g_free(c->ifname);
300 c->ifname = g_strdup(value);
301 }
302
can_host_socketcan_instance_init(Object * obj)303 static void can_host_socketcan_instance_init(Object *obj)
304 {
305 CanHostSocketCAN *c = CAN_HOST_SOCKETCAN(obj);
306
307 c->fd = -1;
308 }
309
can_host_socketcan_class_init(ObjectClass * klass,void * class_data G_GNUC_UNUSED)310 static void can_host_socketcan_class_init(ObjectClass *klass,
311 void *class_data G_GNUC_UNUSED)
312 {
313 CanHostClass *chc = CAN_HOST_CLASS(klass);
314
315 object_class_property_add_str(klass, "if",
316 can_host_socketcan_get_if,
317 can_host_socketcan_set_if);
318 chc->connect = can_host_socketcan_connect;
319 chc->disconnect = can_host_socketcan_disconnect;
320 }
321
322 static const TypeInfo can_host_socketcan_info = {
323 .parent = TYPE_CAN_HOST,
324 .name = TYPE_CAN_HOST_SOCKETCAN,
325 .instance_size = sizeof(CanHostSocketCAN),
326 .instance_init = can_host_socketcan_instance_init,
327 .class_init = can_host_socketcan_class_init,
328 };
329
can_host_register_types(void)330 static void can_host_register_types(void)
331 {
332 type_register_static(&can_host_socketcan_info);
333 }
334
335 type_init(can_host_register_types);
336