/* * CAN c support to connect to the Linux host SocketCAN interfaces * * Copyright (c) 2013-2014 Jin Yang * Copyright (c) 2014-2018 Pavel Pisa * * Initial development supported by Google GSoC 2013 from RTEMS project slot * * Permission is hereby granted, free of charge, to any person obtaining a copy * of this software and associated documentation files (the "Software"), to deal * in the Software without restriction, including without limitation the rights * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell * copies of the Software, and to permit persons to whom the Software is * furnished to do so, subject to the following conditions: * * The above copyright notice and this permission notice shall be included in * all copies or substantial portions of the Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN * THE SOFTWARE. */ #include "qemu/osdep.h" #include "qemu/log.h" #include "qapi/error.h" #include "chardev/char.h" #include "qemu/sockets.h" #include "qemu/error-report.h" #include "net/can_emu.h" #include "net/can_host.h" #include <sys/ioctl.h> #include <net/if.h> #include <linux/can.h> #include <linux/can/raw.h> #ifndef DEBUG_CAN #define DEBUG_CAN 0 #endif /*DEBUG_CAN*/ #define TYPE_CAN_HOST_SOCKETCAN "can-host-socketcan" #define CAN_HOST_SOCKETCAN(obj) \ OBJECT_CHECK(CanHostSocketCAN, (obj), TYPE_CAN_HOST_SOCKETCAN) #define CAN_READ_BUF_LEN 5 typedef struct CanHostSocketCAN { CanHostState parent; char *ifname; qemu_can_filter *rfilter; int rfilter_num; can_err_mask_t err_mask; qemu_can_frame buf[CAN_READ_BUF_LEN]; int bufcnt; int bufptr; int fd; } CanHostSocketCAN; /* Check that QEMU and Linux kernel flags encoding and structure matches */ QEMU_BUILD_BUG_ON(QEMU_CAN_EFF_FLAG != CAN_EFF_FLAG); QEMU_BUILD_BUG_ON(QEMU_CAN_RTR_FLAG != CAN_RTR_FLAG); QEMU_BUILD_BUG_ON(QEMU_CAN_ERR_FLAG != CAN_ERR_FLAG); QEMU_BUILD_BUG_ON(QEMU_CAN_INV_FILTER != CAN_INV_FILTER); QEMU_BUILD_BUG_ON(offsetof(qemu_can_frame, data) != offsetof(struct can_frame, data)); static void can_host_socketcan_display_msg(struct qemu_can_frame *msg) { int i; qemu_log_lock(); qemu_log("[cansocketcan]: %03X [%01d] %s %s", msg->can_id & QEMU_CAN_EFF_MASK, msg->can_dlc, msg->can_id & QEMU_CAN_EFF_FLAG ? "EFF" : "SFF", msg->can_id & QEMU_CAN_RTR_FLAG ? "RTR" : "DAT"); for (i = 0; i < msg->can_dlc; i++) { qemu_log(" %02X", msg->data[i]); } qemu_log("\n"); qemu_log_flush(); qemu_log_unlock(); } static void can_host_socketcan_read(void *opaque) { CanHostSocketCAN *c = opaque; CanHostState *ch = CAN_HOST(c); /* CAN_READ_BUF_LEN for multiple messages syscall is possible for future */ c->bufcnt = read(c->fd, c->buf, sizeof(qemu_can_frame)); if (c->bufcnt < 0) { warn_report("CAN bus host read failed (%s)", strerror(errno)); return; } can_bus_client_send(&ch->bus_client, c->buf, 1); if (DEBUG_CAN) { can_host_socketcan_display_msg(c->buf); } } static int can_host_socketcan_can_receive(CanBusClientState *client) { return 1; } static ssize_t can_host_socketcan_receive(CanBusClientState *client, const qemu_can_frame *frames, size_t frames_cnt) { CanHostState *ch = container_of(client, CanHostState, bus_client); CanHostSocketCAN *c = CAN_HOST_SOCKETCAN(ch); size_t len = sizeof(qemu_can_frame); int res; if (c->fd < 0) { return -1; } res = write(c->fd, frames, len); if (!res) { warn_report("[cansocketcan]: write message to host returns zero"); return -1; } if (res != len) { if (res < 0) { warn_report("[cansocketcan]: write to host failed (%s)", strerror(errno)); } else { warn_report("[cansocketcan]: write to host truncated"); } return -1; } return 1; } static void can_host_socketcan_disconnect(CanHostState *ch) { CanHostSocketCAN *c = CAN_HOST_SOCKETCAN(ch); if (c->fd >= 0) { qemu_set_fd_handler(c->fd, NULL, NULL, c); close(c->fd); c->fd = -1; } g_free(c->rfilter); c->rfilter = NULL; c->rfilter_num = 0; } static CanBusClientInfo can_host_socketcan_bus_client_info = { .can_receive = can_host_socketcan_can_receive, .receive = can_host_socketcan_receive, }; static void can_host_socketcan_connect(CanHostState *ch, Error **errp) { CanHostSocketCAN *c = CAN_HOST_SOCKETCAN(ch); int s; /* can raw socket */ struct sockaddr_can addr; struct ifreq ifr; /* open socket */ s = qemu_socket(PF_CAN, SOCK_RAW, CAN_RAW); if (s < 0) { error_setg_errno(errp, errno, "failed to create CAN_RAW socket"); return; } addr.can_family = AF_CAN; memset(&ifr.ifr_name, 0, sizeof(ifr.ifr_name)); strcpy(ifr.ifr_name, c->ifname); if (ioctl(s, SIOCGIFINDEX, &ifr) < 0) { error_setg_errno(errp, errno, "SocketCAN host interface %s not available", c->ifname); goto fail; } addr.can_ifindex = ifr.ifr_ifindex; c->err_mask = 0xffffffff; /* Receive error frame. */ setsockopt(s, SOL_CAN_RAW, CAN_RAW_ERR_FILTER, &c->err_mask, sizeof(c->err_mask)); c->rfilter_num = 1; c->rfilter = g_new(struct qemu_can_filter, c->rfilter_num); /* Receive all data frame. If |= CAN_INV_FILTER no data. */ c->rfilter[0].can_id = 0; c->rfilter[0].can_mask = 0; c->rfilter[0].can_mask &= ~CAN_ERR_FLAG; setsockopt(s, SOL_CAN_RAW, CAN_RAW_FILTER, c->rfilter, c->rfilter_num * sizeof(struct qemu_can_filter)); if (bind(s, (struct sockaddr *)&addr, sizeof(addr)) < 0) { error_setg_errno(errp, errno, "failed to bind to host interface %s", c->ifname); goto fail; } c->fd = s; ch->bus_client.info = &can_host_socketcan_bus_client_info; qemu_set_fd_handler(c->fd, can_host_socketcan_read, NULL, c); return; fail: close(s); g_free(c->rfilter); c->rfilter = NULL; c->rfilter_num = 0; } static char *can_host_socketcan_get_if(Object *obj, Error **errp) { CanHostSocketCAN *c = CAN_HOST_SOCKETCAN(obj); return g_strdup(c->ifname); } static void can_host_socketcan_set_if(Object *obj, const char *value, Error **errp) { CanHostSocketCAN *c = CAN_HOST_SOCKETCAN(obj); struct ifreq ifr; if (strlen(value) >= sizeof(ifr.ifr_name)) { error_setg(errp, "CAN interface name longer than %zd characters", sizeof(ifr.ifr_name) - 1); return; } if (c->fd != -1) { error_setg(errp, "CAN interface already connected"); return; } g_free(c->ifname); c->ifname = g_strdup(value); } static void can_host_socketcan_instance_init(Object *obj) { CanHostSocketCAN *c = CAN_HOST_SOCKETCAN(obj); c->fd = -1; } static void can_host_socketcan_class_init(ObjectClass *klass, void *class_data G_GNUC_UNUSED) { CanHostClass *chc = CAN_HOST_CLASS(klass); object_class_property_add_str(klass, "if", can_host_socketcan_get_if, can_host_socketcan_set_if, &error_abort); chc->connect = can_host_socketcan_connect; chc->disconnect = can_host_socketcan_disconnect; } static const TypeInfo can_host_socketcan_info = { .parent = TYPE_CAN_HOST, .name = TYPE_CAN_HOST_SOCKETCAN, .instance_size = sizeof(CanHostSocketCAN), .instance_init = can_host_socketcan_instance_init, .class_init = can_host_socketcan_class_init, }; static void can_host_register_types(void) { type_register_static(&can_host_socketcan_info); } type_init(can_host_register_types);