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_flush(); 93 qemu_log_unlock(logfile); 94 } 95 } 96 97 static void can_host_socketcan_read(void *opaque) 98 { 99 CanHostSocketCAN *c = opaque; 100 CanHostState *ch = CAN_HOST(c); 101 102 /* CAN_READ_BUF_LEN for multiple messages syscall is possible for future */ 103 c->bufcnt = read(c->fd, c->buf, sizeof(qemu_can_frame)); 104 if (c->bufcnt < 0) { 105 warn_report("CAN bus host read failed (%s)", strerror(errno)); 106 return; 107 } 108 109 if (!ch->bus_client.fd_mode) { 110 c->buf[0].flags = 0; 111 } else { 112 if (c->bufcnt > CAN_MTU) { 113 c->buf[0].flags |= QEMU_CAN_FRMF_TYPE_FD; 114 } 115 } 116 117 can_bus_client_send(&ch->bus_client, c->buf, 1); 118 119 if (DEBUG_CAN) { 120 can_host_socketcan_display_msg(c->buf); 121 } 122 } 123 124 static bool can_host_socketcan_can_receive(CanBusClientState *client) 125 { 126 return true; 127 } 128 129 static ssize_t can_host_socketcan_receive(CanBusClientState *client, 130 const qemu_can_frame *frames, size_t frames_cnt) 131 { 132 CanHostState *ch = container_of(client, CanHostState, bus_client); 133 CanHostSocketCAN *c = CAN_HOST_SOCKETCAN(ch); 134 135 size_t len; 136 int res; 137 138 if (c->fd < 0) { 139 return -1; 140 } 141 if (frames->flags & QEMU_CAN_FRMF_TYPE_FD) { 142 if (!ch->bus_client.fd_mode) { 143 return 0; 144 } 145 len = CANFD_MTU; 146 } else { 147 len = CAN_MTU; 148 149 } 150 151 res = write(c->fd, frames, len); 152 153 if (!res) { 154 warn_report("[cansocketcan]: write message to host returns zero"); 155 return -1; 156 } 157 158 if (res != len) { 159 if (res < 0) { 160 warn_report("[cansocketcan]: write to host failed (%s)", 161 strerror(errno)); 162 } else { 163 warn_report("[cansocketcan]: write to host truncated"); 164 } 165 return -1; 166 } 167 168 return 1; 169 } 170 171 static void can_host_socketcan_disconnect(CanHostState *ch) 172 { 173 CanHostSocketCAN *c = CAN_HOST_SOCKETCAN(ch); 174 175 if (c->fd >= 0) { 176 qemu_set_fd_handler(c->fd, NULL, NULL, c); 177 close(c->fd); 178 c->fd = -1; 179 } 180 181 g_free(c->rfilter); 182 c->rfilter = NULL; 183 c->rfilter_num = 0; 184 } 185 186 static CanBusClientInfo can_host_socketcan_bus_client_info = { 187 .can_receive = can_host_socketcan_can_receive, 188 .receive = can_host_socketcan_receive, 189 }; 190 191 static void can_host_socketcan_connect(CanHostState *ch, Error **errp) 192 { 193 CanHostSocketCAN *c = CAN_HOST_SOCKETCAN(ch); 194 int s; /* can raw socket */ 195 int mtu; 196 int enable_canfd = 1; 197 struct sockaddr_can addr; 198 struct ifreq ifr; 199 200 if (!c->ifname) { 201 error_setg(errp, "'if' property not set"); 202 return; 203 } 204 205 /* open socket */ 206 s = qemu_socket(PF_CAN, SOCK_RAW, CAN_RAW); 207 if (s < 0) { 208 error_setg_errno(errp, errno, "failed to create CAN_RAW socket"); 209 return; 210 } 211 212 addr.can_family = AF_CAN; 213 memset(&ifr.ifr_name, 0, sizeof(ifr.ifr_name)); 214 strcpy(ifr.ifr_name, c->ifname); 215 /* check if the frame fits into the CAN netdevice */ 216 if (ioctl(s, SIOCGIFINDEX, &ifr) < 0) { 217 error_setg_errno(errp, errno, 218 "SocketCAN host interface %s not available", 219 c->ifname); 220 goto fail; 221 } 222 addr.can_ifindex = ifr.ifr_ifindex; 223 224 if (ioctl(s, SIOCGIFMTU, &ifr) < 0) { 225 error_setg_errno(errp, errno, 226 "SocketCAN host interface %s SIOCGIFMTU failed", 227 c->ifname); 228 goto fail; 229 } 230 mtu = ifr.ifr_mtu; 231 232 if (mtu >= CANFD_MTU) { 233 /* interface is ok - try to switch the socket into CAN FD mode */ 234 if (setsockopt(s, SOL_CAN_RAW, CAN_RAW_FD_FRAMES, 235 &enable_canfd, sizeof(enable_canfd))) { 236 warn_report("SocketCAN host interface %s enabling CAN FD failed", 237 c->ifname); 238 } else { 239 c->parent.bus_client.fd_mode = true; 240 } 241 } 242 243 c->err_mask = 0xffffffff; /* Receive error frame. */ 244 setsockopt(s, SOL_CAN_RAW, CAN_RAW_ERR_FILTER, 245 &c->err_mask, sizeof(c->err_mask)); 246 247 c->rfilter_num = 1; 248 c->rfilter = g_new(struct qemu_can_filter, c->rfilter_num); 249 250 /* Receive all data frame. If |= CAN_INV_FILTER no data. */ 251 c->rfilter[0].can_id = 0; 252 c->rfilter[0].can_mask = 0; 253 c->rfilter[0].can_mask &= ~CAN_ERR_FLAG; 254 255 setsockopt(s, SOL_CAN_RAW, CAN_RAW_FILTER, c->rfilter, 256 c->rfilter_num * sizeof(struct qemu_can_filter)); 257 258 if (bind(s, (struct sockaddr *)&addr, sizeof(addr)) < 0) { 259 error_setg_errno(errp, errno, "failed to bind to host interface %s", 260 c->ifname); 261 goto fail; 262 } 263 264 c->fd = s; 265 ch->bus_client.info = &can_host_socketcan_bus_client_info; 266 qemu_set_fd_handler(c->fd, can_host_socketcan_read, NULL, c); 267 return; 268 269 fail: 270 close(s); 271 g_free(c->rfilter); 272 c->rfilter = NULL; 273 c->rfilter_num = 0; 274 } 275 276 static char *can_host_socketcan_get_if(Object *obj, Error **errp) 277 { 278 CanHostSocketCAN *c = CAN_HOST_SOCKETCAN(obj); 279 280 return g_strdup(c->ifname); 281 } 282 283 static void can_host_socketcan_set_if(Object *obj, const char *value, 284 Error **errp) 285 { 286 CanHostSocketCAN *c = CAN_HOST_SOCKETCAN(obj); 287 struct ifreq ifr; 288 289 if (strlen(value) >= sizeof(ifr.ifr_name)) { 290 error_setg(errp, "CAN interface name longer than %zd characters", 291 sizeof(ifr.ifr_name) - 1); 292 return; 293 } 294 295 if (c->fd != -1) { 296 error_setg(errp, "CAN interface already connected"); 297 return; 298 } 299 300 g_free(c->ifname); 301 c->ifname = g_strdup(value); 302 } 303 304 static void can_host_socketcan_instance_init(Object *obj) 305 { 306 CanHostSocketCAN *c = CAN_HOST_SOCKETCAN(obj); 307 308 c->fd = -1; 309 } 310 311 static void can_host_socketcan_class_init(ObjectClass *klass, 312 void *class_data G_GNUC_UNUSED) 313 { 314 CanHostClass *chc = CAN_HOST_CLASS(klass); 315 316 object_class_property_add_str(klass, "if", 317 can_host_socketcan_get_if, 318 can_host_socketcan_set_if); 319 chc->connect = can_host_socketcan_connect; 320 chc->disconnect = can_host_socketcan_disconnect; 321 } 322 323 static const TypeInfo can_host_socketcan_info = { 324 .parent = TYPE_CAN_HOST, 325 .name = TYPE_CAN_HOST_SOCKETCAN, 326 .instance_size = sizeof(CanHostSocketCAN), 327 .instance_init = can_host_socketcan_instance_init, 328 .class_init = can_host_socketcan_class_init, 329 }; 330 331 static void can_host_register_types(void) 332 { 333 type_register_static(&can_host_socketcan_info); 334 } 335 336 type_init(can_host_register_types); 337