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 typedef struct CanHostSocketCAN CanHostSocketCAN; 51 DECLARE_INSTANCE_CHECKER(CanHostSocketCAN, CAN_HOST_SOCKETCAN, 52 TYPE_CAN_HOST_SOCKETCAN) 53 54 #define CAN_READ_BUF_LEN 5 55 struct CanHostSocketCAN { 56 CanHostState parent; 57 char *ifname; 58 59 qemu_can_filter *rfilter; 60 int rfilter_num; 61 can_err_mask_t err_mask; 62 63 qemu_can_frame buf[CAN_READ_BUF_LEN]; 64 int bufcnt; 65 int bufptr; 66 67 int fd; 68 }; 69 70 /* Check that QEMU and Linux kernel flags encoding and structure matches */ 71 QEMU_BUILD_BUG_ON(QEMU_CAN_EFF_FLAG != CAN_EFF_FLAG); 72 QEMU_BUILD_BUG_ON(QEMU_CAN_RTR_FLAG != CAN_RTR_FLAG); 73 QEMU_BUILD_BUG_ON(QEMU_CAN_ERR_FLAG != CAN_ERR_FLAG); 74 QEMU_BUILD_BUG_ON(QEMU_CAN_INV_FILTER != CAN_INV_FILTER); 75 QEMU_BUILD_BUG_ON(offsetof(qemu_can_frame, data) 76 != offsetof(struct can_frame, data)); 77 78 static void can_host_socketcan_display_msg(struct qemu_can_frame *msg) 79 { 80 int i; 81 FILE *logfile = qemu_log_lock(); 82 qemu_log("[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 qemu_log(" %02X", msg->data[i]); 90 } 91 qemu_log("\n"); 92 qemu_log_flush(); 93 qemu_log_unlock(logfile); 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 can_bus_client_send(&ch->bus_client, c->buf, 1); 109 110 if (DEBUG_CAN) { 111 can_host_socketcan_display_msg(c->buf); 112 } 113 } 114 115 static bool can_host_socketcan_can_receive(CanBusClientState *client) 116 { 117 return true; 118 } 119 120 static ssize_t can_host_socketcan_receive(CanBusClientState *client, 121 const qemu_can_frame *frames, size_t frames_cnt) 122 { 123 CanHostState *ch = container_of(client, CanHostState, bus_client); 124 CanHostSocketCAN *c = CAN_HOST_SOCKETCAN(ch); 125 126 size_t len = sizeof(qemu_can_frame); 127 int res; 128 129 if (c->fd < 0) { 130 return -1; 131 } 132 133 res = write(c->fd, frames, len); 134 135 if (!res) { 136 warn_report("[cansocketcan]: write message to host returns zero"); 137 return -1; 138 } 139 140 if (res != len) { 141 if (res < 0) { 142 warn_report("[cansocketcan]: write to host failed (%s)", 143 strerror(errno)); 144 } else { 145 warn_report("[cansocketcan]: write to host truncated"); 146 } 147 return -1; 148 } 149 150 return 1; 151 } 152 153 static void can_host_socketcan_disconnect(CanHostState *ch) 154 { 155 CanHostSocketCAN *c = CAN_HOST_SOCKETCAN(ch); 156 157 if (c->fd >= 0) { 158 qemu_set_fd_handler(c->fd, NULL, NULL, c); 159 close(c->fd); 160 c->fd = -1; 161 } 162 163 g_free(c->rfilter); 164 c->rfilter = NULL; 165 c->rfilter_num = 0; 166 } 167 168 static CanBusClientInfo can_host_socketcan_bus_client_info = { 169 .can_receive = can_host_socketcan_can_receive, 170 .receive = can_host_socketcan_receive, 171 }; 172 173 static void can_host_socketcan_connect(CanHostState *ch, Error **errp) 174 { 175 CanHostSocketCAN *c = CAN_HOST_SOCKETCAN(ch); 176 int s; /* can raw socket */ 177 struct sockaddr_can addr; 178 struct ifreq ifr; 179 180 /* open socket */ 181 s = qemu_socket(PF_CAN, SOCK_RAW, CAN_RAW); 182 if (s < 0) { 183 error_setg_errno(errp, errno, "failed to create CAN_RAW socket"); 184 return; 185 } 186 187 addr.can_family = AF_CAN; 188 memset(&ifr.ifr_name, 0, sizeof(ifr.ifr_name)); 189 strcpy(ifr.ifr_name, c->ifname); 190 if (ioctl(s, SIOCGIFINDEX, &ifr) < 0) { 191 error_setg_errno(errp, errno, 192 "SocketCAN host interface %s not available", c->ifname); 193 goto fail; 194 } 195 addr.can_ifindex = ifr.ifr_ifindex; 196 197 c->err_mask = 0xffffffff; /* Receive error frame. */ 198 setsockopt(s, SOL_CAN_RAW, CAN_RAW_ERR_FILTER, 199 &c->err_mask, sizeof(c->err_mask)); 200 201 c->rfilter_num = 1; 202 c->rfilter = g_new(struct qemu_can_filter, c->rfilter_num); 203 204 /* Receive all data frame. If |= CAN_INV_FILTER no data. */ 205 c->rfilter[0].can_id = 0; 206 c->rfilter[0].can_mask = 0; 207 c->rfilter[0].can_mask &= ~CAN_ERR_FLAG; 208 209 setsockopt(s, SOL_CAN_RAW, CAN_RAW_FILTER, c->rfilter, 210 c->rfilter_num * sizeof(struct qemu_can_filter)); 211 212 if (bind(s, (struct sockaddr *)&addr, sizeof(addr)) < 0) { 213 error_setg_errno(errp, errno, "failed to bind to host interface %s", 214 c->ifname); 215 goto fail; 216 } 217 218 c->fd = s; 219 ch->bus_client.info = &can_host_socketcan_bus_client_info; 220 qemu_set_fd_handler(c->fd, can_host_socketcan_read, NULL, c); 221 return; 222 223 fail: 224 close(s); 225 g_free(c->rfilter); 226 c->rfilter = NULL; 227 c->rfilter_num = 0; 228 } 229 230 static char *can_host_socketcan_get_if(Object *obj, Error **errp) 231 { 232 CanHostSocketCAN *c = CAN_HOST_SOCKETCAN(obj); 233 234 return g_strdup(c->ifname); 235 } 236 237 static void can_host_socketcan_set_if(Object *obj, const char *value, Error **errp) 238 { 239 CanHostSocketCAN *c = CAN_HOST_SOCKETCAN(obj); 240 struct ifreq ifr; 241 242 if (strlen(value) >= sizeof(ifr.ifr_name)) { 243 error_setg(errp, "CAN interface name longer than %zd characters", 244 sizeof(ifr.ifr_name) - 1); 245 return; 246 } 247 248 if (c->fd != -1) { 249 error_setg(errp, "CAN interface already connected"); 250 return; 251 } 252 253 g_free(c->ifname); 254 c->ifname = g_strdup(value); 255 } 256 257 static void can_host_socketcan_instance_init(Object *obj) 258 { 259 CanHostSocketCAN *c = CAN_HOST_SOCKETCAN(obj); 260 261 c->fd = -1; 262 } 263 264 static void can_host_socketcan_class_init(ObjectClass *klass, 265 void *class_data G_GNUC_UNUSED) 266 { 267 CanHostClass *chc = CAN_HOST_CLASS(klass); 268 269 object_class_property_add_str(klass, "if", 270 can_host_socketcan_get_if, 271 can_host_socketcan_set_if); 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