net/can: Initial host SocketCan support for CAN FD.
[qemu.git] / net / can / can_socketcan.c
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
76 static void can_host_socketcan_display_msg(struct qemu_can_frame *msg)
77 {
78 int i;
79 FILE *logfile = qemu_log_lock();
80 qemu_log("[cansocketcan]: %03X [%01d] %s %s",
81 msg->can_id & QEMU_CAN_EFF_MASK,
82 msg->can_dlc,
83 msg->can_id & QEMU_CAN_EFF_FLAG ? "EFF" : "SFF",
84 msg->can_id & QEMU_CAN_RTR_FLAG ? "RTR" : "DAT");
85
86 for (i = 0; i < msg->can_dlc; i++) {
87 qemu_log(" %02X", msg->data[i]);
88 }
89 qemu_log("\n");
90 qemu_log_flush();
91 qemu_log_unlock(logfile);
92 }
93
94 static void can_host_socketcan_read(void *opaque)
95 {
96 CanHostSocketCAN *c = opaque;
97 CanHostState *ch = CAN_HOST(c);
98
99 /* CAN_READ_BUF_LEN for multiple messages syscall is possible for future */
100 c->bufcnt = read(c->fd, c->buf, sizeof(qemu_can_frame));
101 if (c->bufcnt < 0) {
102 warn_report("CAN bus host read failed (%s)", strerror(errno));
103 return;
104 }
105
106 if (!ch->bus_client.fd_mode) {
107 c->buf[0].flags = 0;
108 } else {
109 if (c->bufcnt > CAN_MTU) {
110 c->buf[0].flags |= QEMU_CAN_FRMF_TYPE_FD;
111 }
112 }
113
114 can_bus_client_send(&ch->bus_client, c->buf, 1);
115
116 if (DEBUG_CAN) {
117 can_host_socketcan_display_msg(c->buf);
118 }
119 }
120
121 static bool can_host_socketcan_can_receive(CanBusClientState *client)
122 {
123 return true;
124 }
125
126 static ssize_t can_host_socketcan_receive(CanBusClientState *client,
127 const qemu_can_frame *frames, size_t frames_cnt)
128 {
129 CanHostState *ch = container_of(client, CanHostState, bus_client);
130 CanHostSocketCAN *c = CAN_HOST_SOCKETCAN(ch);
131
132 size_t len;
133 int res;
134
135 if (c->fd < 0) {
136 return -1;
137 }
138 if (frames->flags & QEMU_CAN_FRMF_TYPE_FD) {
139 if (!ch->bus_client.fd_mode) {
140 return 0;
141 }
142 len = CANFD_MTU;
143 } else {
144 len = CAN_MTU;
145
146 }
147
148 res = write(c->fd, frames, len);
149
150 if (!res) {
151 warn_report("[cansocketcan]: write message to host returns zero");
152 return -1;
153 }
154
155 if (res != len) {
156 if (res < 0) {
157 warn_report("[cansocketcan]: write to host failed (%s)",
158 strerror(errno));
159 } else {
160 warn_report("[cansocketcan]: write to host truncated");
161 }
162 return -1;
163 }
164
165 return 1;
166 }
167
168 static void can_host_socketcan_disconnect(CanHostState *ch)
169 {
170 CanHostSocketCAN *c = CAN_HOST_SOCKETCAN(ch);
171
172 if (c->fd >= 0) {
173 qemu_set_fd_handler(c->fd, NULL, NULL, c);
174 close(c->fd);
175 c->fd = -1;
176 }
177
178 g_free(c->rfilter);
179 c->rfilter = NULL;
180 c->rfilter_num = 0;
181 }
182
183 static CanBusClientInfo can_host_socketcan_bus_client_info = {
184 .can_receive = can_host_socketcan_can_receive,
185 .receive = can_host_socketcan_receive,
186 };
187
188 static void can_host_socketcan_connect(CanHostState *ch, Error **errp)
189 {
190 CanHostSocketCAN *c = CAN_HOST_SOCKETCAN(ch);
191 int s; /* can raw socket */
192 int mtu;
193 int enable_canfd = 1;
194 struct sockaddr_can addr;
195 struct ifreq ifr;
196
197 /* open socket */
198 s = qemu_socket(PF_CAN, SOCK_RAW, CAN_RAW);
199 if (s < 0) {
200 error_setg_errno(errp, errno, "failed to create CAN_RAW socket");
201 return;
202 }
203
204 addr.can_family = AF_CAN;
205 memset(&ifr.ifr_name, 0, sizeof(ifr.ifr_name));
206 strcpy(ifr.ifr_name, c->ifname);
207 /* check if the frame fits into the CAN netdevice */
208 if (ioctl(s, SIOCGIFINDEX, &ifr) < 0) {
209 error_setg_errno(errp, errno,
210 "SocketCAN host interface %s not available",
211 c->ifname);
212 goto fail;
213 }
214 addr.can_ifindex = ifr.ifr_ifindex;
215
216 if (ioctl(s, SIOCGIFMTU, &ifr) < 0) {
217 error_setg_errno(errp, errno,
218 "SocketCAN host interface %s SIOCGIFMTU failed",
219 c->ifname);
220 goto fail;
221 }
222 mtu = ifr.ifr_mtu;
223
224 if (mtu >= CANFD_MTU) {
225 /* interface is ok - try to switch the socket into CAN FD mode */
226 if (setsockopt(s, SOL_CAN_RAW, CAN_RAW_FD_FRAMES,
227 &enable_canfd, sizeof(enable_canfd))) {
228 warn_report("SocketCAN host interface %s enabling CAN FD failed",
229 c->ifname);
230 } else {
231 c->parent.bus_client.fd_mode = true;
232 }
233 }
234
235 c->err_mask = 0xffffffff; /* Receive error frame. */
236 setsockopt(s, SOL_CAN_RAW, CAN_RAW_ERR_FILTER,
237 &c->err_mask, sizeof(c->err_mask));
238
239 c->rfilter_num = 1;
240 c->rfilter = g_new(struct qemu_can_filter, c->rfilter_num);
241
242 /* Receive all data frame. If |= CAN_INV_FILTER no data. */
243 c->rfilter[0].can_id = 0;
244 c->rfilter[0].can_mask = 0;
245 c->rfilter[0].can_mask &= ~CAN_ERR_FLAG;
246
247 setsockopt(s, SOL_CAN_RAW, CAN_RAW_FILTER, c->rfilter,
248 c->rfilter_num * sizeof(struct qemu_can_filter));
249
250 if (bind(s, (struct sockaddr *)&addr, sizeof(addr)) < 0) {
251 error_setg_errno(errp, errno, "failed to bind to host interface %s",
252 c->ifname);
253 goto fail;
254 }
255
256 c->fd = s;
257 ch->bus_client.info = &can_host_socketcan_bus_client_info;
258 qemu_set_fd_handler(c->fd, can_host_socketcan_read, NULL, c);
259 return;
260
261 fail:
262 close(s);
263 g_free(c->rfilter);
264 c->rfilter = NULL;
265 c->rfilter_num = 0;
266 }
267
268 static char *can_host_socketcan_get_if(Object *obj, Error **errp)
269 {
270 CanHostSocketCAN *c = CAN_HOST_SOCKETCAN(obj);
271
272 return g_strdup(c->ifname);
273 }
274
275 static void can_host_socketcan_set_if(Object *obj, const char *value,
276 Error **errp)
277 {
278 CanHostSocketCAN *c = CAN_HOST_SOCKETCAN(obj);
279 struct ifreq ifr;
280
281 if (strlen(value) >= sizeof(ifr.ifr_name)) {
282 error_setg(errp, "CAN interface name longer than %zd characters",
283 sizeof(ifr.ifr_name) - 1);
284 return;
285 }
286
287 if (c->fd != -1) {
288 error_setg(errp, "CAN interface already connected");
289 return;
290 }
291
292 g_free(c->ifname);
293 c->ifname = g_strdup(value);
294 }
295
296 static void can_host_socketcan_instance_init(Object *obj)
297 {
298 CanHostSocketCAN *c = CAN_HOST_SOCKETCAN(obj);
299
300 c->fd = -1;
301 }
302
303 static void can_host_socketcan_class_init(ObjectClass *klass,
304 void *class_data G_GNUC_UNUSED)
305 {
306 CanHostClass *chc = CAN_HOST_CLASS(klass);
307
308 object_class_property_add_str(klass, "if",
309 can_host_socketcan_get_if,
310 can_host_socketcan_set_if);
311 chc->connect = can_host_socketcan_connect;
312 chc->disconnect = can_host_socketcan_disconnect;
313 }
314
315 static const TypeInfo can_host_socketcan_info = {
316 .parent = TYPE_CAN_HOST,
317 .name = TYPE_CAN_HOST_SOCKETCAN,
318 .instance_size = sizeof(CanHostSocketCAN),
319 .instance_init = can_host_socketcan_instance_init,
320 .class_init = can_host_socketcan_class_init,
321 };
322
323 static void can_host_register_types(void)
324 {
325 type_register_static(&can_host_socketcan_info);
326 }
327
328 type_init(can_host_register_types);