/* * QEMU System Emulator * * Copyright (c) 2003-2008 Fabrice Bellard * Copyright (c) 2009 Red Hat, Inc. * * 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 "tap_int.h" #include <sys/ioctl.h> #include <sys/wait.h> #include <sys/socket.h> #include <net/if.h> #include "net/net.h" #include "clients.h" #include "monitor/monitor.h" #include "sysemu/sysemu.h" #include "qapi/error.h" #include "qemu-common.h" #include "qemu/cutils.h" #include "qemu/error-report.h" #include "net/tap.h" #include "net/vhost_net.h" typedef struct TAPState { NetClientState nc; int fd; char down_script[1024]; char down_script_arg[128]; uint8_t buf[NET_BUFSIZE]; bool read_poll; bool write_poll; bool using_vnet_hdr; bool has_ufo; bool enabled; VHostNetState *vhost_net; unsigned host_vnet_hdr_len; Notifier exit; } TAPState; static void launch_script(const char *setup_script, const char *ifname, int fd, Error **errp); static void tap_send(void *opaque); static void tap_writable(void *opaque); static void tap_update_fd_handler(TAPState *s) { qemu_set_fd_handler(s->fd, s->read_poll && s->enabled ? tap_send : NULL, s->write_poll && s->enabled ? tap_writable : NULL, s); } static void tap_read_poll(TAPState *s, bool enable) { s->read_poll = enable; tap_update_fd_handler(s); } static void tap_write_poll(TAPState *s, bool enable) { s->write_poll = enable; tap_update_fd_handler(s); } static void tap_writable(void *opaque) { TAPState *s = opaque; tap_write_poll(s, false); qemu_flush_queued_packets(&s->nc); } static ssize_t tap_write_packet(TAPState *s, const struct iovec *iov, int iovcnt) { ssize_t len; do { len = writev(s->fd, iov, iovcnt); } while (len == -1 && errno == EINTR); if (len == -1 && errno == EAGAIN) { tap_write_poll(s, true); return 0; } return len; } static ssize_t tap_receive_iov(NetClientState *nc, const struct iovec *iov, int iovcnt) { TAPState *s = DO_UPCAST(TAPState, nc, nc); const struct iovec *iovp = iov; struct iovec iov_copy[iovcnt + 1]; struct virtio_net_hdr_mrg_rxbuf hdr = { }; if (s->host_vnet_hdr_len && !s->using_vnet_hdr) { iov_copy[0].iov_base = &hdr; iov_copy[0].iov_len = s->host_vnet_hdr_len; memcpy(&iov_copy[1], iov, iovcnt * sizeof(*iov)); iovp = iov_copy; iovcnt++; } return tap_write_packet(s, iovp, iovcnt); } static ssize_t tap_receive_raw(NetClientState *nc, const uint8_t *buf, size_t size) { TAPState *s = DO_UPCAST(TAPState, nc, nc); struct iovec iov[2]; int iovcnt = 0; struct virtio_net_hdr_mrg_rxbuf hdr = { }; if (s->host_vnet_hdr_len) { iov[iovcnt].iov_base = &hdr; iov[iovcnt].iov_len = s->host_vnet_hdr_len; iovcnt++; } iov[iovcnt].iov_base = (char *)buf; iov[iovcnt].iov_len = size; iovcnt++; return tap_write_packet(s, iov, iovcnt); } static ssize_t tap_receive(NetClientState *nc, const uint8_t *buf, size_t size) { TAPState *s = DO_UPCAST(TAPState, nc, nc); struct iovec iov[1]; if (s->host_vnet_hdr_len && !s->using_vnet_hdr) { return tap_receive_raw(nc, buf, size); } iov[0].iov_base = (char *)buf; iov[0].iov_len = size; return tap_write_packet(s, iov, 1); } #ifndef __sun__ ssize_t tap_read_packet(int tapfd, uint8_t *buf, int maxlen) { return read(tapfd, buf, maxlen); } #endif static void tap_send_completed(NetClientState *nc, ssize_t len) { TAPState *s = DO_UPCAST(TAPState, nc, nc); tap_read_poll(s, true); } static void tap_send(void *opaque) { TAPState *s = opaque; int size; int packets = 0; while (true) { uint8_t *buf = s->buf; size = tap_read_packet(s->fd, s->buf, sizeof(s->buf)); if (size <= 0) { break; } if (s->host_vnet_hdr_len && !s->using_vnet_hdr) { buf += s->host_vnet_hdr_len; size -= s->host_vnet_hdr_len; } size = qemu_send_packet_async(&s->nc, buf, size, tap_send_completed); if (size == 0) { tap_read_poll(s, false); break; } else if (size < 0) { break; } /* * When the host keeps receiving more packets while tap_send() is * running we can hog the QEMU global mutex. Limit the number of * packets that are processed per tap_send() callback to prevent * stalling the guest. */ packets++; if (packets >= 50) { break; } } } static bool tap_has_ufo(NetClientState *nc) { TAPState *s = DO_UPCAST(TAPState, nc, nc); assert(nc->info->type == NET_CLIENT_DRIVER_TAP); return s->has_ufo; } static bool tap_has_vnet_hdr(NetClientState *nc) { TAPState *s = DO_UPCAST(TAPState, nc, nc); assert(nc->info->type == NET_CLIENT_DRIVER_TAP); return !!s->host_vnet_hdr_len; } static bool tap_has_vnet_hdr_len(NetClientState *nc, int len) { TAPState *s = DO_UPCAST(TAPState, nc, nc); assert(nc->info->type == NET_CLIENT_DRIVER_TAP); return !!tap_probe_vnet_hdr_len(s->fd, len); } static void tap_set_vnet_hdr_len(NetClientState *nc, int len) { TAPState *s = DO_UPCAST(TAPState, nc, nc); assert(nc->info->type == NET_CLIENT_DRIVER_TAP); assert(len == sizeof(struct virtio_net_hdr_mrg_rxbuf) || len == sizeof(struct virtio_net_hdr)); tap_fd_set_vnet_hdr_len(s->fd, len); s->host_vnet_hdr_len = len; } static void tap_using_vnet_hdr(NetClientState *nc, bool using_vnet_hdr) { TAPState *s = DO_UPCAST(TAPState, nc, nc); assert(nc->info->type == NET_CLIENT_DRIVER_TAP); assert(!!s->host_vnet_hdr_len == using_vnet_hdr); s->using_vnet_hdr = using_vnet_hdr; } static int tap_set_vnet_le(NetClientState *nc, bool is_le) { TAPState *s = DO_UPCAST(TAPState, nc, nc); return tap_fd_set_vnet_le(s->fd, is_le); } static int tap_set_vnet_be(NetClientState *nc, bool is_be) { TAPState *s = DO_UPCAST(TAPState, nc, nc); return tap_fd_set_vnet_be(s->fd, is_be); } static void tap_set_offload(NetClientState *nc, int csum, int tso4, int tso6, int ecn, int ufo) { TAPState *s = DO_UPCAST(TAPState, nc, nc); if (s->fd < 0) { return; } tap_fd_set_offload(s->fd, csum, tso4, tso6, ecn, ufo); } static void tap_exit_notify(Notifier *notifier, void *data) { TAPState *s = container_of(notifier, TAPState, exit); Error *err = NULL; if (s->down_script[0]) { launch_script(s->down_script, s->down_script_arg, s->fd, &err); if (err) { error_report_err(err); } } } static void tap_cleanup(NetClientState *nc) { TAPState *s = DO_UPCAST(TAPState, nc, nc); if (s->vhost_net) { vhost_net_cleanup(s->vhost_net); g_free(s->vhost_net); s->vhost_net = NULL; } qemu_purge_queued_packets(nc); tap_exit_notify(&s->exit, NULL); qemu_remove_exit_notifier(&s->exit); tap_read_poll(s, false); tap_write_poll(s, false); close(s->fd); s->fd = -1; } static void tap_poll(NetClientState *nc, bool enable) { TAPState *s = DO_UPCAST(TAPState, nc, nc); tap_read_poll(s, enable); tap_write_poll(s, enable); } int tap_get_fd(NetClientState *nc) { TAPState *s = DO_UPCAST(TAPState, nc, nc); assert(nc->info->type == NET_CLIENT_DRIVER_TAP); return s->fd; } /* fd support */ static NetClientInfo net_tap_info = { .type = NET_CLIENT_DRIVER_TAP, .size = sizeof(TAPState), .receive = tap_receive, .receive_raw = tap_receive_raw, .receive_iov = tap_receive_iov, .poll = tap_poll, .cleanup = tap_cleanup, .has_ufo = tap_has_ufo, .has_vnet_hdr = tap_has_vnet_hdr, .has_vnet_hdr_len = tap_has_vnet_hdr_len, .using_vnet_hdr = tap_using_vnet_hdr, .set_offload = tap_set_offload, .set_vnet_hdr_len = tap_set_vnet_hdr_len, .set_vnet_le = tap_set_vnet_le, .set_vnet_be = tap_set_vnet_be, }; static TAPState *net_tap_fd_init(NetClientState *peer, const char *model, const char *name, int fd, int vnet_hdr) { NetClientState *nc; TAPState *s; nc = qemu_new_net_client(&net_tap_info, peer, model, name); s = DO_UPCAST(TAPState, nc, nc); s->fd = fd; s->host_vnet_hdr_len = vnet_hdr ? sizeof(struct virtio_net_hdr) : 0; s->using_vnet_hdr = false; s->has_ufo = tap_probe_has_ufo(s->fd); s->enabled = true; tap_set_offload(&s->nc, 0, 0, 0, 0, 0); /* * Make sure host header length is set correctly in tap: * it might have been modified by another instance of qemu. */ if (tap_probe_vnet_hdr_len(s->fd, s->host_vnet_hdr_len)) { tap_fd_set_vnet_hdr_len(s->fd, s->host_vnet_hdr_len); } tap_read_poll(s, true); s->vhost_net = NULL; s->exit.notify = tap_exit_notify; qemu_add_exit_notifier(&s->exit); return s; } static void launch_script(const char *setup_script, const char *ifname, int fd, Error **errp) { int pid, status; char *args[3]; char **parg; /* try to launch network script */ pid = fork(); if (pid < 0) { error_setg_errno(errp, errno, "could not launch network script %s", setup_script); return; } if (pid == 0) { int open_max = sysconf(_SC_OPEN_MAX), i; for (i = 3; i < open_max; i++) { if (i != fd) { close(i); } } parg = args; *parg++ = (char *)setup_script; *parg++ = (char *)ifname; *parg = NULL; execv(setup_script, args); _exit(1); } else { while (waitpid(pid, &status, 0) != pid) { /* loop */ } if (WIFEXITED(status) && WEXITSTATUS(status) == 0) { return; } error_setg(errp, "network script %s failed with status %d", setup_script, status); } } static int recv_fd(int c) { int fd; uint8_t msgbuf[CMSG_SPACE(sizeof(fd))]; struct msghdr msg = { .msg_control = msgbuf, .msg_controllen = sizeof(msgbuf), }; struct cmsghdr *cmsg; struct iovec iov; uint8_t req[1]; ssize_t len; cmsg = CMSG_FIRSTHDR(&msg); cmsg->cmsg_level = SOL_SOCKET; cmsg->cmsg_type = SCM_RIGHTS; cmsg->cmsg_len = CMSG_LEN(sizeof(fd)); msg.msg_controllen = cmsg->cmsg_len; iov.iov_base = req; iov.iov_len = sizeof(req); msg.msg_iov = &iov; msg.msg_iovlen = 1; len = recvmsg(c, &msg, 0); if (len > 0) { memcpy(&fd, CMSG_DATA(cmsg), sizeof(fd)); return fd; } return len; } static int net_bridge_run_helper(const char *helper, const char *bridge, Error **errp) { sigset_t oldmask, mask; int pid, status; char *args[5]; char **parg; int sv[2]; sigemptyset(&mask); sigaddset(&mask, SIGCHLD); sigprocmask(SIG_BLOCK, &mask, &oldmask); if (socketpair(PF_UNIX, SOCK_STREAM, 0, sv) == -1) { error_setg_errno(errp, errno, "socketpair() failed"); return -1; } /* try to launch bridge helper */ pid = fork(); if (pid < 0) { error_setg_errno(errp, errno, "Can't fork bridge helper"); return -1; } if (pid == 0) { int open_max = sysconf(_SC_OPEN_MAX), i; char fd_buf[6+10]; char br_buf[6+IFNAMSIZ] = {0}; char helper_cmd[PATH_MAX + sizeof(fd_buf) + sizeof(br_buf) + 15]; for (i = 3; i < open_max; i++) { if (i != sv[1]) { close(i); } } snprintf(fd_buf, sizeof(fd_buf), "%s%d", "--fd=", sv[1]); if (strrchr(helper, ' ') || strrchr(helper, '\t')) { /* assume helper is a command */ if (strstr(helper, "--br=") == NULL) { snprintf(br_buf, sizeof(br_buf), "%s%s", "--br=", bridge); } snprintf(helper_cmd, sizeof(helper_cmd), "%s %s %s %s", helper, "--use-vnet", fd_buf, br_buf); parg = args; *parg++ = (char *)"sh"; *parg++ = (char *)"-c"; *parg++ = helper_cmd; *parg++ = NULL; execv("/bin/sh", args); } else { /* assume helper is just the executable path name */ snprintf(br_buf, sizeof(br_buf), "%s%s", "--br=", bridge); parg = args; *parg++ = (char *)helper; *parg++ = (char *)"--use-vnet"; *parg++ = fd_buf; *parg++ = br_buf; *parg++ = NULL; execv(helper, args); } _exit(1); } else { int fd; int saved_errno; close(sv[1]); do { fd = recv_fd(sv[0]); } while (fd == -1 && errno == EINTR); saved_errno = errno; close(sv[0]); while (waitpid(pid, &status, 0) != pid) { /* loop */ } sigprocmask(SIG_SETMASK, &oldmask, NULL); if (fd < 0) { error_setg_errno(errp, saved_errno, "failed to recv file descriptor"); return -1; } if (!WIFEXITED(status) || WEXITSTATUS(status) != 0) { error_setg(errp, "bridge helper failed"); return -1; } return fd; } } int net_init_bridge(const Netdev *netdev, const char *name, NetClientState *peer, Error **errp) { const NetdevBridgeOptions *bridge; const char *helper, *br; TAPState *s; int fd, vnet_hdr; assert(netdev->type == NET_CLIENT_DRIVER_BRIDGE); bridge = &netdev->u.bridge; helper = bridge->has_helper ? bridge->helper : DEFAULT_BRIDGE_HELPER; br = bridge->has_br ? bridge->br : DEFAULT_BRIDGE_INTERFACE; fd = net_bridge_run_helper(helper, br, errp); if (fd == -1) { return -1; } fcntl(fd, F_SETFL, O_NONBLOCK); vnet_hdr = tap_probe_vnet_hdr(fd); s = net_tap_fd_init(peer, "bridge", name, fd, vnet_hdr); snprintf(s->nc.info_str, sizeof(s->nc.info_str), "helper=%s,br=%s", helper, br); return 0; } static int net_tap_init(const NetdevTapOptions *tap, int *vnet_hdr, const char *setup_script, char *ifname, size_t ifname_sz, int mq_required, Error **errp) { Error *err = NULL; int fd, vnet_hdr_required; if (tap->has_vnet_hdr) { *vnet_hdr = tap->vnet_hdr; vnet_hdr_required = *vnet_hdr; } else { *vnet_hdr = 1; vnet_hdr_required = 0; } TFR(fd = tap_open(ifname, ifname_sz, vnet_hdr, vnet_hdr_required, mq_required, errp)); if (fd < 0) { return -1; } if (setup_script && setup_script[0] != '\0' && strcmp(setup_script, "no") != 0) { launch_script(setup_script, ifname, fd, &err); if (err) { error_propagate(errp, err); close(fd); return -1; } } return fd; } #define MAX_TAP_QUEUES 1024 static void net_init_tap_one(const NetdevTapOptions *tap, NetClientState *peer, const char *model, const char *name, const char *ifname, const char *script, const char *downscript, const char *vhostfdname, int vnet_hdr, int fd, Error **errp) { Error *err = NULL; TAPState *s = net_tap_fd_init(peer, model, name, fd, vnet_hdr); int vhostfd; tap_set_sndbuf(s->fd, tap, &err); if (err) { error_propagate(errp, err); return; } if (tap->has_fd || tap->has_fds) { snprintf(s->nc.info_str, sizeof(s->nc.info_str), "fd=%d", fd); } else if (tap->has_helper) { snprintf(s->nc.info_str, sizeof(s->nc.info_str), "helper=%s", tap->helper); } else { snprintf(s->nc.info_str, sizeof(s->nc.info_str), "ifname=%s,script=%s,downscript=%s", ifname, script, downscript); if (strcmp(downscript, "no") != 0) { snprintf(s->down_script, sizeof(s->down_script), "%s", downscript); snprintf(s->down_script_arg, sizeof(s->down_script_arg), "%s", ifname); } } if (tap->has_vhost ? tap->vhost : vhostfdname || (tap->has_vhostforce && tap->vhostforce)) { VhostNetOptions options; options.backend_type = VHOST_BACKEND_TYPE_KERNEL; options.net_backend = &s->nc; if (tap->has_poll_us) { options.busyloop_timeout = tap->poll_us; } else { options.busyloop_timeout = 0; } if (vhostfdname) { vhostfd = monitor_fd_param(cur_mon, vhostfdname, &err); if (vhostfd == -1) { error_propagate(errp, err); return; } } else { vhostfd = open("/dev/vhost-net", O_RDWR); if (vhostfd < 0) { error_setg_errno(errp, errno, "tap: open vhost char device failed"); return; } fcntl(vhostfd, F_SETFL, O_NONBLOCK); } options.opaque = (void *)(uintptr_t)vhostfd; s->vhost_net = vhost_net_init(&options); if (!s->vhost_net) { error_setg(errp, "vhost-net requested but could not be initialized"); return; } } else if (vhostfdname) { error_setg(errp, "vhostfd(s)= is not valid without vhost"); } } static int get_fds(char *str, char *fds[], int max) { char *ptr = str, *this; size_t len = strlen(str); int i = 0; while (i < max && ptr < str + len) { this = strchr(ptr, ':'); if (this == NULL) { fds[i] = g_strdup(ptr); } else { fds[i] = g_strndup(ptr, this - ptr); } i++; if (this == NULL) { break; } else { ptr = this + 1; } } return i; } int net_init_tap(const Netdev *netdev, const char *name, NetClientState *peer, Error **errp) { const NetdevTapOptions *tap; int fd, vnet_hdr = 0, i = 0, queues; /* for the no-fd, no-helper case */ const char *script = NULL; /* suppress wrong "uninit'd use" gcc warning */ const char *downscript = NULL; Error *err = NULL; const char *vhostfdname; char ifname[128]; assert(netdev->type == NET_CLIENT_DRIVER_TAP); tap = &netdev->u.tap; queues = tap->has_queues ? tap->queues : 1; vhostfdname = tap->has_vhostfd ? tap->vhostfd : NULL; /* QEMU vlans does not support multiqueue tap, in this case peer is set. * For -netdev, peer is always NULL. */ if (peer && (tap->has_queues || tap->has_fds || tap->has_vhostfds)) { error_setg(errp, "Multiqueue tap cannot be used with QEMU vlans"); return -1; } if (tap->has_fd) { if (tap->has_ifname || tap->has_script || tap->has_downscript || tap->has_vnet_hdr || tap->has_helper || tap->has_queues || tap->has_fds || tap->has_vhostfds) { error_setg(errp, "ifname=, script=, downscript=, vnet_hdr=, " "helper=, queues=, fds=, and vhostfds= " "are invalid with fd="); return -1; } fd = monitor_fd_param(cur_mon, tap->fd, &err); if (fd == -1) { error_propagate(errp, err); return -1; } fcntl(fd, F_SETFL, O_NONBLOCK); vnet_hdr = tap_probe_vnet_hdr(fd); net_init_tap_one(tap, peer, "tap", name, NULL, script, downscript, vhostfdname, vnet_hdr, fd, &err); if (err) { error_propagate(errp, err); return -1; } } else if (tap->has_fds) { char **fds; char **vhost_fds; int nfds, nvhosts; if (tap->has_ifname || tap->has_script || tap->has_downscript || tap->has_vnet_hdr || tap->has_helper || tap->has_queues || tap->has_vhostfd) { error_setg(errp, "ifname=, script=, downscript=, vnet_hdr=, " "helper=, queues=, and vhostfd= " "are invalid with fds="); return -1; } fds = g_new0(char *, MAX_TAP_QUEUES); vhost_fds = g_new0(char *, MAX_TAP_QUEUES); nfds = get_fds(tap->fds, fds, MAX_TAP_QUEUES); if (tap->has_vhostfds) { nvhosts = get_fds(tap->vhostfds, vhost_fds, MAX_TAP_QUEUES); if (nfds != nvhosts) { error_setg(errp, "The number of fds passed does not match " "the number of vhostfds passed"); goto free_fail; } } for (i = 0; i < nfds; i++) { fd = monitor_fd_param(cur_mon, fds[i], &err); if (fd == -1) { error_propagate(errp, err); goto free_fail; } fcntl(fd, F_SETFL, O_NONBLOCK); if (i == 0) { vnet_hdr = tap_probe_vnet_hdr(fd); } else if (vnet_hdr != tap_probe_vnet_hdr(fd)) { error_setg(errp, "vnet_hdr not consistent across given tap fds"); goto free_fail; } net_init_tap_one(tap, peer, "tap", name, ifname, script, downscript, tap->has_vhostfds ? vhost_fds[i] : NULL, vnet_hdr, fd, &err); if (err) { error_propagate(errp, err); goto free_fail; } } g_free(fds); g_free(vhost_fds); return 0; free_fail: for (i = 0; i < nfds; i++) { g_free(fds[i]); g_free(vhost_fds[i]); } g_free(fds); g_free(vhost_fds); return -1; } else if (tap->has_helper) { if (tap->has_ifname || tap->has_script || tap->has_downscript || tap->has_vnet_hdr || tap->has_queues || tap->has_vhostfds) { error_setg(errp, "ifname=, script=, downscript=, vnet_hdr=, " "queues=, and vhostfds= are invalid with helper="); return -1; } fd = net_bridge_run_helper(tap->helper, tap->has_br ? tap->br : DEFAULT_BRIDGE_INTERFACE, errp); if (fd == -1) { return -1; } fcntl(fd, F_SETFL, O_NONBLOCK); vnet_hdr = tap_probe_vnet_hdr(fd); net_init_tap_one(tap, peer, "bridge", name, ifname, script, downscript, vhostfdname, vnet_hdr, fd, &err); if (err) { error_propagate(errp, err); close(fd); return -1; } } else { if (tap->has_vhostfds) { error_setg(errp, "vhostfds= is invalid if fds= wasn't specified"); return -1; } script = tap->has_script ? tap->script : DEFAULT_NETWORK_SCRIPT; downscript = tap->has_downscript ? tap->downscript : DEFAULT_NETWORK_DOWN_SCRIPT; if (tap->has_ifname) { pstrcpy(ifname, sizeof ifname, tap->ifname); } else { ifname[0] = '\0'; } for (i = 0; i < queues; i++) { fd = net_tap_init(tap, &vnet_hdr, i >= 1 ? "no" : script, ifname, sizeof ifname, queues > 1, errp); if (fd == -1) { return -1; } if (queues > 1 && i == 0 && !tap->has_ifname) { if (tap_fd_get_ifname(fd, ifname)) { error_setg(errp, "Fail to get ifname"); close(fd); return -1; } } net_init_tap_one(tap, peer, "tap", name, ifname, i >= 1 ? "no" : script, i >= 1 ? "no" : downscript, vhostfdname, vnet_hdr, fd, &err); if (err) { error_propagate(errp, err); close(fd); return -1; } } } return 0; } VHostNetState *tap_get_vhost_net(NetClientState *nc) { TAPState *s = DO_UPCAST(TAPState, nc, nc); assert(nc->info->type == NET_CLIENT_DRIVER_TAP); return s->vhost_net; } int tap_enable(NetClientState *nc) { TAPState *s = DO_UPCAST(TAPState, nc, nc); int ret; if (s->enabled) { return 0; } else { ret = tap_fd_enable(s->fd); if (ret == 0) { s->enabled = true; tap_update_fd_handler(s); } return ret; } } int tap_disable(NetClientState *nc) { TAPState *s = DO_UPCAST(TAPState, nc, nc); int ret; if (s->enabled == 0) { return 0; } else { ret = tap_fd_disable(s->fd); if (ret == 0) { qemu_purge_queued_packets(nc); s->enabled = false; tap_update_fd_handler(s); } return ret; } }