can_socketcan.c (9799B)
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_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 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 } 122 123 static bool can_host_socketcan_can_receive(CanBusClientState *client) 124 { 125 return true; 126 } 127 128 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 } 169 170 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 }; 189 190 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 } 274 275 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 } 281 282 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 } 302 303 static void can_host_socketcan_instance_init(Object *obj) 304 { 305 CanHostSocketCAN *c = CAN_HOST_SOCKETCAN(obj); 306 307 c->fd = -1; 308 } 309 310 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 }; 329 330 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);