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 #include "qemu/osdep.h" 28 #include "qemu/log.h" 29 #include "qapi/error.h" 30 #include "chardev/char.h" 31 #include "qemu/sockets.h" 32 #include "qemu/error-report.h" 33 #include "net/can_emu.h" 34 #include "net/can_host.h" 35 36 #include <sys/ioctl.h> 37 #include <net/if.h> 38 #include <linux/can.h> 39 #include <linux/can/raw.h> 40 41 #ifndef DEBUG_CAN 42 #define DEBUG_CAN 0 43 #endif /*DEBUG_CAN*/ 44 45 #define TYPE_CAN_HOST_SOCKETCAN "can-host-socketcan" 46 #define CAN_HOST_SOCKETCAN(obj) \ 47 OBJECT_CHECK(CanHostSocketCAN, (obj), TYPE_CAN_HOST_SOCKETCAN) 48 49 #define CAN_READ_BUF_LEN 5 50 typedef struct CanHostSocketCAN { 51 CanHostState parent; 52 char *ifname; 53 54 qemu_can_filter *rfilter; 55 int rfilter_num; 56 can_err_mask_t err_mask; 57 58 qemu_can_frame buf[CAN_READ_BUF_LEN]; 59 int bufcnt; 60 int bufptr; 61 62 int fd; 63 } CanHostSocketCAN; 64 65 /* Check that QEMU and Linux kernel flags encoding and structure matches */ 66 QEMU_BUILD_BUG_ON(QEMU_CAN_EFF_FLAG != CAN_EFF_FLAG); 67 QEMU_BUILD_BUG_ON(QEMU_CAN_RTR_FLAG != CAN_RTR_FLAG); 68 QEMU_BUILD_BUG_ON(QEMU_CAN_ERR_FLAG != CAN_ERR_FLAG); 69 QEMU_BUILD_BUG_ON(QEMU_CAN_INV_FILTER != CAN_INV_FILTER); 70 QEMU_BUILD_BUG_ON(offsetof(qemu_can_frame, data) 71 != offsetof(struct can_frame, data)); 72 73 static void can_host_socketcan_display_msg(struct qemu_can_frame *msg) 74 { 75 int i; 76 77 qemu_log_lock(); 78 qemu_log("[cansocketcan]: %03X [%01d] %s %s", 79 msg->can_id & QEMU_CAN_EFF_MASK, 80 msg->can_dlc, 81 msg->can_id & QEMU_CAN_EFF_FLAG ? "EFF" : "SFF", 82 msg->can_id & QEMU_CAN_RTR_FLAG ? "RTR" : "DAT"); 83 84 for (i = 0; i < msg->can_dlc; i++) { 85 qemu_log(" %02X", msg->data[i]); 86 } 87 qemu_log("\n"); 88 qemu_log_flush(); 89 qemu_log_unlock(); 90 } 91 92 static void can_host_socketcan_read(void *opaque) 93 { 94 CanHostSocketCAN *c = opaque; 95 CanHostState *ch = CAN_HOST(c); 96 97 /* CAN_READ_BUF_LEN for multiple messages syscall is possible for future */ 98 c->bufcnt = read(c->fd, c->buf, sizeof(qemu_can_frame)); 99 if (c->bufcnt < 0) { 100 warn_report("CAN bus host read failed (%s)", strerror(errno)); 101 return; 102 } 103 104 can_bus_client_send(&ch->bus_client, c->buf, 1); 105 106 if (DEBUG_CAN) { 107 can_host_socketcan_display_msg(c->buf); 108 } 109 } 110 111 static int can_host_socketcan_can_receive(CanBusClientState *client) 112 { 113 return 1; 114 } 115 116 static ssize_t can_host_socketcan_receive(CanBusClientState *client, 117 const qemu_can_frame *frames, size_t frames_cnt) 118 { 119 CanHostState *ch = container_of(client, CanHostState, bus_client); 120 CanHostSocketCAN *c = CAN_HOST_SOCKETCAN(ch); 121 122 size_t len = sizeof(qemu_can_frame); 123 int res; 124 125 if (c->fd < 0) { 126 return -1; 127 } 128 129 res = write(c->fd, frames, len); 130 131 if (!res) { 132 warn_report("[cansocketcan]: write message to host returns zero"); 133 return -1; 134 } 135 136 if (res != len) { 137 if (res < 0) { 138 warn_report("[cansocketcan]: write to host failed (%s)", 139 strerror(errno)); 140 } else { 141 warn_report("[cansocketcan]: write to host truncated"); 142 } 143 return -1; 144 } 145 146 return 1; 147 } 148 149 static void can_host_socketcan_disconnect(CanHostState *ch) 150 { 151 CanHostSocketCAN *c = CAN_HOST_SOCKETCAN(ch); 152 153 if (c->fd >= 0) { 154 qemu_set_fd_handler(c->fd, NULL, NULL, c); 155 close(c->fd); 156 c->fd = -1; 157 } 158 159 g_free(c->rfilter); 160 c->rfilter = NULL; 161 c->rfilter_num = 0; 162 } 163 164 static CanBusClientInfo can_host_socketcan_bus_client_info = { 165 .can_receive = can_host_socketcan_can_receive, 166 .receive = can_host_socketcan_receive, 167 }; 168 169 static void can_host_socketcan_connect(CanHostState *ch, Error **errp) 170 { 171 CanHostSocketCAN *c = CAN_HOST_SOCKETCAN(ch); 172 int s; /* can raw socket */ 173 struct sockaddr_can addr; 174 struct ifreq ifr; 175 176 /* open socket */ 177 s = qemu_socket(PF_CAN, SOCK_RAW, CAN_RAW); 178 if (s < 0) { 179 error_setg_errno(errp, errno, "failed to create CAN_RAW socket"); 180 return; 181 } 182 183 addr.can_family = AF_CAN; 184 memset(&ifr.ifr_name, 0, sizeof(ifr.ifr_name)); 185 strcpy(ifr.ifr_name, c->ifname); 186 if (ioctl(s, SIOCGIFINDEX, &ifr) < 0) { 187 error_setg_errno(errp, errno, 188 "SocketCAN host interface %s not available", c->ifname); 189 goto fail; 190 } 191 addr.can_ifindex = ifr.ifr_ifindex; 192 193 c->err_mask = 0xffffffff; /* Receive error frame. */ 194 setsockopt(s, SOL_CAN_RAW, CAN_RAW_ERR_FILTER, 195 &c->err_mask, sizeof(c->err_mask)); 196 197 c->rfilter_num = 1; 198 c->rfilter = g_new(struct qemu_can_filter, c->rfilter_num); 199 200 /* Receive all data frame. If |= CAN_INV_FILTER no data. */ 201 c->rfilter[0].can_id = 0; 202 c->rfilter[0].can_mask = 0; 203 c->rfilter[0].can_mask &= ~CAN_ERR_FLAG; 204 205 setsockopt(s, SOL_CAN_RAW, CAN_RAW_FILTER, c->rfilter, 206 c->rfilter_num * sizeof(struct qemu_can_filter)); 207 208 if (bind(s, (struct sockaddr *)&addr, sizeof(addr)) < 0) { 209 error_setg_errno(errp, errno, "failed to bind to host interface %s", 210 c->ifname); 211 goto fail; 212 } 213 214 c->fd = s; 215 ch->bus_client.info = &can_host_socketcan_bus_client_info; 216 qemu_set_fd_handler(c->fd, can_host_socketcan_read, NULL, c); 217 return; 218 219 fail: 220 close(s); 221 g_free(c->rfilter); 222 c->rfilter = NULL; 223 c->rfilter_num = 0; 224 } 225 226 static char *can_host_socketcan_get_if(Object *obj, Error **errp) 227 { 228 CanHostSocketCAN *c = CAN_HOST_SOCKETCAN(obj); 229 230 return g_strdup(c->ifname); 231 } 232 233 static void can_host_socketcan_set_if(Object *obj, const char *value, Error **errp) 234 { 235 CanHostSocketCAN *c = CAN_HOST_SOCKETCAN(obj); 236 struct ifreq ifr; 237 238 if (strlen(value) >= sizeof(ifr.ifr_name)) { 239 error_setg(errp, "CAN interface name longer than %zd characters", 240 sizeof(ifr.ifr_name) - 1); 241 return; 242 } 243 244 if (c->fd != -1) { 245 error_setg(errp, "CAN interface already connected"); 246 return; 247 } 248 249 g_free(c->ifname); 250 c->ifname = g_strdup(value); 251 } 252 253 static void can_host_socketcan_instance_init(Object *obj) 254 { 255 CanHostSocketCAN *c = CAN_HOST_SOCKETCAN(obj); 256 257 c->fd = -1; 258 } 259 260 static void can_host_socketcan_class_init(ObjectClass *klass, 261 void *class_data G_GNUC_UNUSED) 262 { 263 CanHostClass *chc = CAN_HOST_CLASS(klass); 264 265 object_class_property_add_str(klass, "if", 266 can_host_socketcan_get_if, 267 can_host_socketcan_set_if, 268 &error_abort); 269 chc->connect = can_host_socketcan_connect; 270 chc->disconnect = can_host_socketcan_disconnect; 271 } 272 273 static const TypeInfo can_host_socketcan_info = { 274 .parent = TYPE_CAN_HOST, 275 .name = TYPE_CAN_HOST_SOCKETCAN, 276 .instance_size = sizeof(CanHostSocketCAN), 277 .instance_init = can_host_socketcan_instance_init, 278 .class_init = can_host_socketcan_class_init, 279 }; 280 281 static void can_host_register_types(void) 282 { 283 type_register_static(&can_host_socketcan_info); 284 } 285 286 type_init(can_host_register_types); 287