net/can/can_socketcan.c

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