int net_init_tap(const NetClientOptions *opts, const char *name, NetClientState *peer) { 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; const char *vhostfdname; char ifname[128]; assert(opts->kind == NET_CLIENT_OPTIONS_KIND_TAP); tap = opts->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_report("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) { error_report("ifname=, script=, downscript=, vnet_hdr=, " "helper=, queues=, and fds= are invalid with fd="); return -1; } fd = monitor_handle_fd_param(cur_mon, tap->fd); if (fd == -1) { return -1; } fcntl(fd, F_SETFL, O_NONBLOCK); vnet_hdr = tap_probe_vnet_hdr(fd); if (net_init_tap_one(tap, peer, "tap", name, NULL, script, downscript, vhostfdname, vnet_hdr, fd)) { return -1; } } else if (tap->has_fds) { char *fds[MAX_TAP_QUEUES]; char *vhost_fds[MAX_TAP_QUEUES]; 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_fd) { error_report("ifname=, script=, downscript=, vnet_hdr=, " "helper=, queues=, and fd= are invalid with fds="); return -1; } 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_report("The number of fds passed does not match the " "number of vhostfds passed"); return -1; } } for (i = 0; i < nfds; i++) { fd = monitor_handle_fd_param(cur_mon, fds[i]); if (fd == -1) { return -1; } 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_report("vnet_hdr not consistent across given tap fds"); return -1; } if (net_init_tap_one(tap, peer, "tap", name, ifname, script, downscript, tap->has_vhostfds ? vhost_fds[i] : NULL, vnet_hdr, fd)) { 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_fds) { error_report("ifname=, script=, downscript=, and vnet_hdr= " "queues=, and fds= are invalid with helper="); return -1; } fd = net_bridge_run_helper(tap->helper, DEFAULT_BRIDGE_INTERFACE); if (fd == -1) { return -1; } fcntl(fd, F_SETFL, O_NONBLOCK); vnet_hdr = tap_probe_vnet_hdr(fd); if (net_init_tap_one(tap, peer, "bridge", name, ifname, script, downscript, vhostfdname, vnet_hdr, fd)) { return -1; } } else { 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); if (fd == -1) { return -1; } if (queues > 1 && i == 0 && !tap->has_ifname) { if (tap_fd_get_ifname(fd, ifname)) { error_report("Fail to get ifname"); return -1; } } if (net_init_tap_one(tap, peer, "tap", name, ifname, i >= 1 ? "no" : script, i >= 1 ? "no" : downscript, vhostfdname, vnet_hdr, fd)) { return -1; } } } return 0; }