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