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 44 #ifndef DEBUG_CAN 45 #define DEBUG_CAN 0 46 #endif /*DEBUG_CAN*/ 47 48 #define TYPE_CAN_HOST_SOCKETCAN "can-host-socketcan" 49 #define CAN_HOST_SOCKETCAN(obj) \ 50 OBJECT_CHECK(CanHostSocketCAN, (obj), TYPE_CAN_HOST_SOCKETCAN) 51 52 #define CAN_READ_BUF_LEN 5 53 typedef 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 } CanHostSocketCAN; 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 80 qemu_log_lock(); 81 qemu_log("[cansocketcan]: %03X [%01d] %s %s", 82 msg->can_id & QEMU_CAN_EFF_MASK, 83 msg->can_dlc, 84 msg->can_id & QEMU_CAN_EFF_FLAG ? "EFF" : "SFF", 85 msg->can_id & QEMU_CAN_RTR_FLAG ? "RTR" : "DAT"); 86 87 for (i = 0; i < msg->can_dlc; i++) { 88 qemu_log(" %02X", msg->data[i]); 89 } 90 qemu_log("\n"); 91 qemu_log_flush(); 92 qemu_log_unlock(); 93 } 94 95 static void can_host_socketcan_read(void *opaque) 96 { 97 CanHostSocketCAN *c = opaque; 98 CanHostState *ch = CAN_HOST(c); 99 100 /* CAN_READ_BUF_LEN for multiple messages syscall is possible for future */ 101 c->bufcnt = read(c->fd, c->buf, sizeof(qemu_can_frame)); 102 if (c->bufcnt < 0) { 103 warn_report("CAN bus host read failed (%s)", strerror(errno)); 104 return; 105 } 106 107 can_bus_client_send(&ch->bus_client, c->buf, 1); 108 109 if (DEBUG_CAN) { 110 can_host_socketcan_display_msg(c->buf); 111 } 112 } 113 114 static int can_host_socketcan_can_receive(CanBusClientState *client) 115 { 116 return 1; 117 } 118 119 static ssize_t can_host_socketcan_receive(CanBusClientState *client, 120 const qemu_can_frame *frames, size_t frames_cnt) 121 { 122 CanHostState *ch = container_of(client, CanHostState, bus_client); 123 CanHostSocketCAN *c = CAN_HOST_SOCKETCAN(ch); 124 125 size_t len = sizeof(qemu_can_frame); 126 int res; 127 128 if (c->fd < 0) { 129 return -1; 130 } 131 132 res = write(c->fd, frames, len); 133 134 if (!res) { 135 warn_report("[cansocketcan]: write message to host returns zero"); 136 return -1; 137 } 138 139 if (res != len) { 140 if (res < 0) { 141 warn_report("[cansocketcan]: write to host failed (%s)", 142 strerror(errno)); 143 } else { 144 warn_report("[cansocketcan]: write to host truncated"); 145 } 146 return -1; 147 } 148 149 return 1; 150 } 151 152 static void can_host_socketcan_disconnect(CanHostState *ch) 153 { 154 CanHostSocketCAN *c = CAN_HOST_SOCKETCAN(ch); 155 156 if (c->fd >= 0) { 157 qemu_set_fd_handler(c->fd, NULL, NULL, c); 158 close(c->fd); 159 c->fd = -1; 160 } 161 162 g_free(c->rfilter); 163 c->rfilter = NULL; 164 c->rfilter_num = 0; 165 } 166 167 static CanBusClientInfo can_host_socketcan_bus_client_info = { 168 .can_receive = can_host_socketcan_can_receive, 169 .receive = can_host_socketcan_receive, 170 }; 171 172 static void can_host_socketcan_connect(CanHostState *ch, Error **errp) 173 { 174 CanHostSocketCAN *c = CAN_HOST_SOCKETCAN(ch); 175 int s; /* can raw socket */ 176 struct sockaddr_can addr; 177 struct ifreq ifr; 178 179 /* open socket */ 180 s = qemu_socket(PF_CAN, SOCK_RAW, CAN_RAW); 181 if (s < 0) { 182 error_setg_errno(errp, errno, "failed to create CAN_RAW socket"); 183 return; 184 } 185 186 addr.can_family = AF_CAN; 187 memset(&ifr.ifr_name, 0, sizeof(ifr.ifr_name)); 188 strcpy(ifr.ifr_name, c->ifname); 189 if (ioctl(s, SIOCGIFINDEX, &ifr) < 0) { 190 error_setg_errno(errp, errno, 191 "SocketCAN host interface %s not available", c->ifname); 192 goto fail; 193 } 194 addr.can_ifindex = ifr.ifr_ifindex; 195 196 c->err_mask = 0xffffffff; /* Receive error frame. */ 197 setsockopt(s, SOL_CAN_RAW, CAN_RAW_ERR_FILTER, 198 &c->err_mask, sizeof(c->err_mask)); 199 200 c->rfilter_num = 1; 201 c->rfilter = g_new(struct qemu_can_filter, c->rfilter_num); 202 203 /* Receive all data frame. If |= CAN_INV_FILTER no data. */ 204 c->rfilter[0].can_id = 0; 205 c->rfilter[0].can_mask = 0; 206 c->rfilter[0].can_mask &= ~CAN_ERR_FLAG; 207 208 setsockopt(s, SOL_CAN_RAW, CAN_RAW_FILTER, c->rfilter, 209 c->rfilter_num * sizeof(struct qemu_can_filter)); 210 211 if (bind(s, (struct sockaddr *)&addr, sizeof(addr)) < 0) { 212 error_setg_errno(errp, errno, "failed to bind to host interface %s", 213 c->ifname); 214 goto fail; 215 } 216 217 c->fd = s; 218 ch->bus_client.info = &can_host_socketcan_bus_client_info; 219 qemu_set_fd_handler(c->fd, can_host_socketcan_read, NULL, c); 220 return; 221 222 fail: 223 close(s); 224 g_free(c->rfilter); 225 c->rfilter = NULL; 226 c->rfilter_num = 0; 227 } 228 229 static char *can_host_socketcan_get_if(Object *obj, Error **errp) 230 { 231 CanHostSocketCAN *c = CAN_HOST_SOCKETCAN(obj); 232 233 return g_strdup(c->ifname); 234 } 235 236 static void can_host_socketcan_set_if(Object *obj, const char *value, Error **errp) 237 { 238 CanHostSocketCAN *c = CAN_HOST_SOCKETCAN(obj); 239 struct ifreq ifr; 240 241 if (strlen(value) >= sizeof(ifr.ifr_name)) { 242 error_setg(errp, "CAN interface name longer than %zd characters", 243 sizeof(ifr.ifr_name) - 1); 244 return; 245 } 246 247 if (c->fd != -1) { 248 error_setg(errp, "CAN interface already connected"); 249 return; 250 } 251 252 g_free(c->ifname); 253 c->ifname = g_strdup(value); 254 } 255 256 static void can_host_socketcan_instance_init(Object *obj) 257 { 258 CanHostSocketCAN *c = CAN_HOST_SOCKETCAN(obj); 259 260 c->fd = -1; 261 } 262 263 static void can_host_socketcan_class_init(ObjectClass *klass, 264 void *class_data G_GNUC_UNUSED) 265 { 266 CanHostClass *chc = CAN_HOST_CLASS(klass); 267 268 object_class_property_add_str(klass, "if", 269 can_host_socketcan_get_if, 270 can_host_socketcan_set_if, 271 &error_abort); 272 chc->connect = can_host_socketcan_connect; 273 chc->disconnect = can_host_socketcan_disconnect; 274 } 275 276 static const TypeInfo can_host_socketcan_info = { 277 .parent = TYPE_CAN_HOST, 278 .name = TYPE_CAN_HOST_SOCKETCAN, 279 .instance_size = sizeof(CanHostSocketCAN), 280 .instance_init = can_host_socketcan_instance_init, 281 .class_init = can_host_socketcan_class_init, 282 }; 283 284 static void can_host_register_types(void) 285 { 286 type_register_static(&can_host_socketcan_info); 287 } 288 289 type_init(can_host_register_types); 290