1 /* 2 * QEMU System Emulator 3 * 4 * Copyright (c) 2003-2008 Fabrice Bellard 5 * Copyright (c) 2009 Red Hat, Inc. 6 * 7 * Permission is hereby granted, free of charge, to any person obtaining a copy 8 * of this software and associated documentation files (the "Software"), to deal 9 * in the Software without restriction, including without limitation the rights 10 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell 11 * copies of the Software, and to permit persons to whom the Software is 12 * furnished to do so, subject to the following conditions: 13 * 14 * The above copyright notice and this permission notice shall be included in 15 * all copies or substantial portions of the Software. 16 * 17 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 18 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 19 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL 20 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 21 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, 22 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN 23 * THE SOFTWARE. 24 */ 25 26 #include "qemu/osdep.h" 27 #include "tap_int.h" 28 29 30 #include <sys/ioctl.h> 31 #include <sys/wait.h> 32 #include <sys/socket.h> 33 #include <net/if.h> 34 35 #include "net/eth.h" 36 #include "net/net.h" 37 #include "clients.h" 38 #include "monitor/monitor.h" 39 #include "system/system.h" 40 #include "qapi/error.h" 41 #include "qemu/cutils.h" 42 #include "qemu/error-report.h" 43 #include "qemu/main-loop.h" 44 #include "qemu/sockets.h" 45 #include "hw/virtio/vhost.h" 46 47 #include "net/tap.h" 48 49 #include "net/vhost_net.h" 50 51 static const int kernel_feature_bits[] = { 52 VIRTIO_F_NOTIFY_ON_EMPTY, 53 VIRTIO_RING_F_INDIRECT_DESC, 54 VIRTIO_RING_F_EVENT_IDX, 55 VIRTIO_NET_F_MRG_RXBUF, 56 VIRTIO_F_VERSION_1, 57 VIRTIO_NET_F_MTU, 58 VIRTIO_F_IOMMU_PLATFORM, 59 VIRTIO_F_RING_PACKED, 60 VIRTIO_F_RING_RESET, 61 VIRTIO_F_IN_ORDER, 62 VIRTIO_F_NOTIFICATION_DATA, 63 VIRTIO_NET_F_RSC_EXT, 64 VIRTIO_NET_F_HASH_REPORT, 65 VHOST_INVALID_FEATURE_BIT 66 }; 67 68 typedef struct TAPState { 69 NetClientState nc; 70 int fd; 71 char down_script[1024]; 72 char down_script_arg[128]; 73 uint8_t buf[NET_BUFSIZE]; 74 bool read_poll; 75 bool write_poll; 76 bool using_vnet_hdr; 77 bool has_ufo; 78 bool has_uso; 79 bool enabled; 80 VHostNetState *vhost_net; 81 unsigned host_vnet_hdr_len; 82 Notifier exit; 83 } TAPState; 84 85 static void launch_script(const char *setup_script, const char *ifname, 86 int fd, Error **errp); 87 88 static void tap_send(void *opaque); 89 static void tap_writable(void *opaque); 90 91 static void tap_update_fd_handler(TAPState *s) 92 { 93 qemu_set_fd_handler(s->fd, 94 s->read_poll && s->enabled ? tap_send : NULL, 95 s->write_poll && s->enabled ? tap_writable : NULL, 96 s); 97 } 98 99 static void tap_read_poll(TAPState *s, bool enable) 100 { 101 s->read_poll = enable; 102 tap_update_fd_handler(s); 103 } 104 105 static void tap_write_poll(TAPState *s, bool enable) 106 { 107 s->write_poll = enable; 108 tap_update_fd_handler(s); 109 } 110 111 static void tap_writable(void *opaque) 112 { 113 TAPState *s = opaque; 114 115 tap_write_poll(s, false); 116 117 qemu_flush_queued_packets(&s->nc); 118 } 119 120 static ssize_t tap_write_packet(TAPState *s, const struct iovec *iov, int iovcnt) 121 { 122 ssize_t len; 123 124 len = RETRY_ON_EINTR(writev(s->fd, iov, iovcnt)); 125 126 if (len == -1 && errno == EAGAIN) { 127 tap_write_poll(s, true); 128 return 0; 129 } 130 131 return len; 132 } 133 134 static ssize_t tap_receive_iov(NetClientState *nc, const struct iovec *iov, 135 int iovcnt) 136 { 137 TAPState *s = DO_UPCAST(TAPState, nc, nc); 138 const struct iovec *iovp = iov; 139 g_autofree struct iovec *iov_copy = NULL; 140 struct virtio_net_hdr hdr = { }; 141 142 if (s->host_vnet_hdr_len && !s->using_vnet_hdr) { 143 iov_copy = g_new(struct iovec, iovcnt + 1); 144 iov_copy[0].iov_base = &hdr; 145 iov_copy[0].iov_len = s->host_vnet_hdr_len; 146 memcpy(&iov_copy[1], iov, iovcnt * sizeof(*iov)); 147 iovp = iov_copy; 148 iovcnt++; 149 } 150 151 return tap_write_packet(s, iovp, iovcnt); 152 } 153 154 static ssize_t tap_receive(NetClientState *nc, const uint8_t *buf, size_t size) 155 { 156 struct iovec iov = { 157 .iov_base = (void *)buf, 158 .iov_len = size 159 }; 160 161 return tap_receive_iov(nc, &iov, 1); 162 } 163 164 #ifndef __sun__ 165 ssize_t tap_read_packet(int tapfd, uint8_t *buf, int maxlen) 166 { 167 return read(tapfd, buf, maxlen); 168 } 169 #endif 170 171 static void tap_send_completed(NetClientState *nc, ssize_t len) 172 { 173 TAPState *s = DO_UPCAST(TAPState, nc, nc); 174 tap_read_poll(s, true); 175 } 176 177 static void tap_send(void *opaque) 178 { 179 TAPState *s = opaque; 180 int size; 181 int packets = 0; 182 183 while (true) { 184 uint8_t *buf = s->buf; 185 uint8_t min_pkt[ETH_ZLEN]; 186 size_t min_pktsz = sizeof(min_pkt); 187 188 size = tap_read_packet(s->fd, s->buf, sizeof(s->buf)); 189 if (size <= 0) { 190 break; 191 } 192 193 if (s->host_vnet_hdr_len && size <= s->host_vnet_hdr_len) { 194 /* Invalid packet */ 195 break; 196 } 197 198 if (s->host_vnet_hdr_len && !s->using_vnet_hdr) { 199 buf += s->host_vnet_hdr_len; 200 size -= s->host_vnet_hdr_len; 201 } 202 203 if (net_peer_needs_padding(&s->nc)) { 204 if (eth_pad_short_frame(min_pkt, &min_pktsz, buf, size)) { 205 buf = min_pkt; 206 size = min_pktsz; 207 } 208 } 209 210 size = qemu_send_packet_async(&s->nc, buf, size, tap_send_completed); 211 if (size == 0) { 212 tap_read_poll(s, false); 213 break; 214 } else if (size < 0) { 215 break; 216 } 217 218 /* 219 * When the host keeps receiving more packets while tap_send() is 220 * running we can hog the BQL. Limit the number of 221 * packets that are processed per tap_send() callback to prevent 222 * stalling the guest. 223 */ 224 packets++; 225 if (packets >= 50) { 226 break; 227 } 228 } 229 } 230 231 static bool tap_has_ufo(NetClientState *nc) 232 { 233 TAPState *s = DO_UPCAST(TAPState, nc, nc); 234 235 assert(nc->info->type == NET_CLIENT_DRIVER_TAP); 236 237 return s->has_ufo; 238 } 239 240 static bool tap_has_uso(NetClientState *nc) 241 { 242 TAPState *s = DO_UPCAST(TAPState, nc, nc); 243 244 assert(nc->info->type == NET_CLIENT_DRIVER_TAP); 245 246 return s->has_uso; 247 } 248 249 static bool tap_has_vnet_hdr(NetClientState *nc) 250 { 251 TAPState *s = DO_UPCAST(TAPState, nc, nc); 252 253 assert(nc->info->type == NET_CLIENT_DRIVER_TAP); 254 255 return !!s->host_vnet_hdr_len; 256 } 257 258 static bool tap_has_vnet_hdr_len(NetClientState *nc, int len) 259 { 260 return tap_has_vnet_hdr(nc); 261 } 262 263 static void tap_set_vnet_hdr_len(NetClientState *nc, int len) 264 { 265 TAPState *s = DO_UPCAST(TAPState, nc, nc); 266 267 assert(nc->info->type == NET_CLIENT_DRIVER_TAP); 268 269 tap_fd_set_vnet_hdr_len(s->fd, len); 270 s->host_vnet_hdr_len = len; 271 s->using_vnet_hdr = true; 272 } 273 274 static int tap_set_vnet_le(NetClientState *nc, bool is_le) 275 { 276 TAPState *s = DO_UPCAST(TAPState, nc, nc); 277 278 return tap_fd_set_vnet_le(s->fd, is_le); 279 } 280 281 static int tap_set_vnet_be(NetClientState *nc, bool is_be) 282 { 283 TAPState *s = DO_UPCAST(TAPState, nc, nc); 284 285 return tap_fd_set_vnet_be(s->fd, is_be); 286 } 287 288 static void tap_set_offload(NetClientState *nc, int csum, int tso4, 289 int tso6, int ecn, int ufo, int uso4, int uso6) 290 { 291 TAPState *s = DO_UPCAST(TAPState, nc, nc); 292 if (s->fd < 0) { 293 return; 294 } 295 296 tap_fd_set_offload(s->fd, csum, tso4, tso6, ecn, ufo, uso4, uso6); 297 } 298 299 static void tap_exit_notify(Notifier *notifier, void *data) 300 { 301 TAPState *s = container_of(notifier, TAPState, exit); 302 Error *err = NULL; 303 304 if (s->down_script[0]) { 305 launch_script(s->down_script, s->down_script_arg, s->fd, &err); 306 if (err) { 307 error_report_err(err); 308 } 309 } 310 } 311 312 static void tap_cleanup(NetClientState *nc) 313 { 314 TAPState *s = DO_UPCAST(TAPState, nc, nc); 315 316 if (s->vhost_net) { 317 vhost_net_cleanup(s->vhost_net); 318 g_free(s->vhost_net); 319 s->vhost_net = NULL; 320 } 321 322 qemu_purge_queued_packets(nc); 323 324 tap_exit_notify(&s->exit, NULL); 325 qemu_remove_exit_notifier(&s->exit); 326 327 tap_read_poll(s, false); 328 tap_write_poll(s, false); 329 close(s->fd); 330 s->fd = -1; 331 } 332 333 static void tap_poll(NetClientState *nc, bool enable) 334 { 335 TAPState *s = DO_UPCAST(TAPState, nc, nc); 336 tap_read_poll(s, enable); 337 tap_write_poll(s, enable); 338 } 339 340 static bool tap_set_steering_ebpf(NetClientState *nc, int prog_fd) 341 { 342 TAPState *s = DO_UPCAST(TAPState, nc, nc); 343 assert(nc->info->type == NET_CLIENT_DRIVER_TAP); 344 345 return tap_fd_set_steering_ebpf(s->fd, prog_fd) == 0; 346 } 347 348 int tap_get_fd(NetClientState *nc) 349 { 350 TAPState *s = DO_UPCAST(TAPState, nc, nc); 351 assert(nc->info->type == NET_CLIENT_DRIVER_TAP); 352 return s->fd; 353 } 354 355 /* 356 * tap_get_vhost_net() can return NULL if a tap net-device backend is 357 * created with 'vhost=off' option, 'vhostforce=off' or no vhost or 358 * vhostforce or vhostfd options at all. Please see net_init_tap_one(). 359 */ 360 static VHostNetState *tap_get_vhost_net(NetClientState *nc) 361 { 362 TAPState *s = DO_UPCAST(TAPState, nc, nc); 363 assert(nc->info->type == NET_CLIENT_DRIVER_TAP); 364 return s->vhost_net; 365 } 366 367 /* fd support */ 368 369 static NetClientInfo net_tap_info = { 370 .type = NET_CLIENT_DRIVER_TAP, 371 .size = sizeof(TAPState), 372 .receive = tap_receive, 373 .receive_iov = tap_receive_iov, 374 .poll = tap_poll, 375 .cleanup = tap_cleanup, 376 .has_ufo = tap_has_ufo, 377 .has_uso = tap_has_uso, 378 .has_vnet_hdr = tap_has_vnet_hdr, 379 .has_vnet_hdr_len = tap_has_vnet_hdr_len, 380 .set_offload = tap_set_offload, 381 .set_vnet_hdr_len = tap_set_vnet_hdr_len, 382 .set_vnet_le = tap_set_vnet_le, 383 .set_vnet_be = tap_set_vnet_be, 384 .set_steering_ebpf = tap_set_steering_ebpf, 385 .get_vhost_net = tap_get_vhost_net, 386 }; 387 388 static TAPState *net_tap_fd_init(NetClientState *peer, 389 const char *model, 390 const char *name, 391 int fd, 392 int vnet_hdr) 393 { 394 NetClientState *nc; 395 TAPState *s; 396 397 nc = qemu_new_net_client(&net_tap_info, peer, model, name); 398 399 s = DO_UPCAST(TAPState, nc, nc); 400 401 s->fd = fd; 402 s->host_vnet_hdr_len = vnet_hdr ? sizeof(struct virtio_net_hdr) : 0; 403 s->using_vnet_hdr = false; 404 s->has_ufo = tap_probe_has_ufo(s->fd); 405 s->has_uso = tap_probe_has_uso(s->fd); 406 s->enabled = true; 407 tap_set_offload(&s->nc, 0, 0, 0, 0, 0, 0, 0); 408 /* 409 * Make sure host header length is set correctly in tap: 410 * it might have been modified by another instance of qemu. 411 */ 412 if (vnet_hdr) { 413 tap_fd_set_vnet_hdr_len(s->fd, s->host_vnet_hdr_len); 414 } 415 tap_read_poll(s, true); 416 s->vhost_net = NULL; 417 418 s->exit.notify = tap_exit_notify; 419 qemu_add_exit_notifier(&s->exit); 420 421 return s; 422 } 423 424 static void close_all_fds_after_fork(int excluded_fd) 425 { 426 const int skip_fd[] = {STDIN_FILENO, STDOUT_FILENO, STDERR_FILENO, 427 excluded_fd}; 428 unsigned int nskip = ARRAY_SIZE(skip_fd); 429 430 /* 431 * skip_fd must be an ordered array of distinct fds, exclude 432 * excluded_fd if already included in the [STDIN_FILENO - STDERR_FILENO] 433 * range 434 */ 435 if (excluded_fd <= STDERR_FILENO) { 436 nskip--; 437 } 438 439 qemu_close_all_open_fd(skip_fd, nskip); 440 } 441 442 static void launch_script(const char *setup_script, const char *ifname, 443 int fd, Error **errp) 444 { 445 int pid, status; 446 char *args[3]; 447 char **parg; 448 449 /* try to launch network script */ 450 pid = fork(); 451 if (pid < 0) { 452 error_setg_errno(errp, errno, "could not launch network script %s", 453 setup_script); 454 return; 455 } 456 if (pid == 0) { 457 close_all_fds_after_fork(fd); 458 parg = args; 459 *parg++ = (char *)setup_script; 460 *parg++ = (char *)ifname; 461 *parg = NULL; 462 execv(setup_script, args); 463 _exit(1); 464 } else { 465 while (waitpid(pid, &status, 0) != pid) { 466 /* loop */ 467 } 468 469 if (WIFEXITED(status) && WEXITSTATUS(status) == 0) { 470 return; 471 } 472 error_setg(errp, "network script %s failed with status %d", 473 setup_script, status); 474 } 475 } 476 477 static int recv_fd(int c) 478 { 479 int fd; 480 uint8_t msgbuf[CMSG_SPACE(sizeof(fd))]; 481 struct msghdr msg = { 482 .msg_control = msgbuf, 483 .msg_controllen = sizeof(msgbuf), 484 }; 485 struct cmsghdr *cmsg; 486 struct iovec iov; 487 uint8_t req[1]; 488 ssize_t len; 489 490 cmsg = CMSG_FIRSTHDR(&msg); 491 cmsg->cmsg_level = SOL_SOCKET; 492 cmsg->cmsg_type = SCM_RIGHTS; 493 cmsg->cmsg_len = CMSG_LEN(sizeof(fd)); 494 msg.msg_controllen = cmsg->cmsg_len; 495 496 iov.iov_base = req; 497 iov.iov_len = sizeof(req); 498 499 msg.msg_iov = &iov; 500 msg.msg_iovlen = 1; 501 502 len = recvmsg(c, &msg, 0); 503 if (len > 0) { 504 memcpy(&fd, CMSG_DATA(cmsg), sizeof(fd)); 505 return fd; 506 } 507 508 return len; 509 } 510 511 static int net_bridge_run_helper(const char *helper, const char *bridge, 512 Error **errp) 513 { 514 sigset_t oldmask, mask; 515 g_autofree char *default_helper = NULL; 516 int pid, status; 517 char *args[5]; 518 char **parg; 519 int sv[2]; 520 521 sigemptyset(&mask); 522 sigaddset(&mask, SIGCHLD); 523 sigprocmask(SIG_BLOCK, &mask, &oldmask); 524 525 if (!helper) { 526 helper = default_helper = get_relocated_path(DEFAULT_BRIDGE_HELPER); 527 } 528 529 if (socketpair(PF_UNIX, SOCK_STREAM, 0, sv) == -1) { 530 error_setg_errno(errp, errno, "socketpair() failed"); 531 return -1; 532 } 533 534 /* try to launch bridge helper */ 535 pid = fork(); 536 if (pid < 0) { 537 error_setg_errno(errp, errno, "Can't fork bridge helper"); 538 return -1; 539 } 540 if (pid == 0) { 541 char *fd_buf = NULL; 542 char *br_buf = NULL; 543 char *helper_cmd = NULL; 544 545 close_all_fds_after_fork(sv[1]); 546 fd_buf = g_strdup_printf("%s%d", "--fd=", sv[1]); 547 548 if (strrchr(helper, ' ') || strrchr(helper, '\t')) { 549 /* assume helper is a command */ 550 551 if (strstr(helper, "--br=") == NULL) { 552 br_buf = g_strdup_printf("%s%s", "--br=", bridge); 553 } 554 555 helper_cmd = g_strdup_printf("%s %s %s %s", helper, 556 "--use-vnet", fd_buf, br_buf ? br_buf : ""); 557 558 parg = args; 559 *parg++ = (char *)"sh"; 560 *parg++ = (char *)"-c"; 561 *parg++ = helper_cmd; 562 *parg++ = NULL; 563 564 execv("/bin/sh", args); 565 g_free(helper_cmd); 566 } else { 567 /* assume helper is just the executable path name */ 568 569 br_buf = g_strdup_printf("%s%s", "--br=", bridge); 570 571 parg = args; 572 *parg++ = (char *)helper; 573 *parg++ = (char *)"--use-vnet"; 574 *parg++ = fd_buf; 575 *parg++ = br_buf; 576 *parg++ = NULL; 577 578 execv(helper, args); 579 } 580 g_free(fd_buf); 581 g_free(br_buf); 582 _exit(1); 583 584 } else { 585 int fd; 586 int saved_errno; 587 588 close(sv[1]); 589 590 fd = RETRY_ON_EINTR(recv_fd(sv[0])); 591 saved_errno = errno; 592 593 close(sv[0]); 594 595 while (waitpid(pid, &status, 0) != pid) { 596 /* loop */ 597 } 598 sigprocmask(SIG_SETMASK, &oldmask, NULL); 599 if (fd < 0) { 600 error_setg_errno(errp, saved_errno, 601 "failed to recv file descriptor"); 602 return -1; 603 } 604 if (!WIFEXITED(status) || WEXITSTATUS(status) != 0) { 605 error_setg(errp, "bridge helper failed"); 606 return -1; 607 } 608 return fd; 609 } 610 } 611 612 int net_init_bridge(const Netdev *netdev, const char *name, 613 NetClientState *peer, Error **errp) 614 { 615 const NetdevBridgeOptions *bridge; 616 const char *helper, *br; 617 TAPState *s; 618 int fd, vnet_hdr; 619 620 assert(netdev->type == NET_CLIENT_DRIVER_BRIDGE); 621 bridge = &netdev->u.bridge; 622 helper = bridge->helper; 623 br = bridge->br ?: DEFAULT_BRIDGE_INTERFACE; 624 625 fd = net_bridge_run_helper(helper, br, errp); 626 if (fd == -1) { 627 return -1; 628 } 629 630 if (!g_unix_set_fd_nonblocking(fd, true, NULL)) { 631 error_setg_errno(errp, errno, "Failed to set FD nonblocking"); 632 return -1; 633 } 634 vnet_hdr = tap_probe_vnet_hdr(fd, errp); 635 if (vnet_hdr < 0) { 636 close(fd); 637 return -1; 638 } 639 s = net_tap_fd_init(peer, "bridge", name, fd, vnet_hdr); 640 641 qemu_set_info_str(&s->nc, "helper=%s,br=%s", helper, br); 642 643 return 0; 644 } 645 646 static int net_tap_init(const NetdevTapOptions *tap, int *vnet_hdr, 647 const char *setup_script, char *ifname, 648 size_t ifname_sz, int mq_required, Error **errp) 649 { 650 Error *err = NULL; 651 int fd, vnet_hdr_required; 652 653 if (tap->has_vnet_hdr) { 654 *vnet_hdr = tap->vnet_hdr; 655 vnet_hdr_required = *vnet_hdr; 656 } else { 657 *vnet_hdr = 1; 658 vnet_hdr_required = 0; 659 } 660 661 fd = RETRY_ON_EINTR(tap_open(ifname, ifname_sz, vnet_hdr, vnet_hdr_required, 662 mq_required, errp)); 663 if (fd < 0) { 664 return -1; 665 } 666 667 if (setup_script && 668 setup_script[0] != '\0' && 669 strcmp(setup_script, "no") != 0) { 670 launch_script(setup_script, ifname, fd, &err); 671 if (err) { 672 error_propagate(errp, err); 673 close(fd); 674 return -1; 675 } 676 } 677 678 return fd; 679 } 680 681 #define MAX_TAP_QUEUES 1024 682 683 static void net_init_tap_one(const NetdevTapOptions *tap, NetClientState *peer, 684 const char *model, const char *name, 685 const char *ifname, const char *script, 686 const char *downscript, const char *vhostfdname, 687 int vnet_hdr, int fd, Error **errp) 688 { 689 Error *err = NULL; 690 TAPState *s = net_tap_fd_init(peer, model, name, fd, vnet_hdr); 691 int vhostfd; 692 693 tap_set_sndbuf(s->fd, tap, &err); 694 if (err) { 695 error_propagate(errp, err); 696 goto failed; 697 } 698 699 if (tap->fd || tap->fds) { 700 qemu_set_info_str(&s->nc, "fd=%d", fd); 701 } else if (tap->helper) { 702 qemu_set_info_str(&s->nc, "helper=%s", tap->helper); 703 } else { 704 qemu_set_info_str(&s->nc, "ifname=%s,script=%s,downscript=%s", ifname, 705 script, downscript); 706 707 if (strcmp(downscript, "no") != 0) { 708 snprintf(s->down_script, sizeof(s->down_script), "%s", downscript); 709 snprintf(s->down_script_arg, sizeof(s->down_script_arg), 710 "%s", ifname); 711 } 712 } 713 714 if (tap->has_vhost ? tap->vhost : 715 vhostfdname || (tap->has_vhostforce && tap->vhostforce)) { 716 VhostNetOptions options; 717 718 options.backend_type = VHOST_BACKEND_TYPE_KERNEL; 719 options.net_backend = &s->nc; 720 if (tap->has_poll_us) { 721 options.busyloop_timeout = tap->poll_us; 722 } else { 723 options.busyloop_timeout = 0; 724 } 725 726 if (vhostfdname) { 727 vhostfd = monitor_fd_param(monitor_cur(), vhostfdname, &err); 728 if (vhostfd == -1) { 729 error_propagate(errp, err); 730 goto failed; 731 } 732 if (!g_unix_set_fd_nonblocking(vhostfd, true, NULL)) { 733 error_setg_errno(errp, errno, "%s: Can't use file descriptor %d", 734 name, fd); 735 goto failed; 736 } 737 } else { 738 vhostfd = open("/dev/vhost-net", O_RDWR); 739 if (vhostfd < 0) { 740 error_setg_errno(errp, errno, 741 "tap: open vhost char device failed"); 742 goto failed; 743 } 744 if (!g_unix_set_fd_nonblocking(vhostfd, true, NULL)) { 745 error_setg_errno(errp, errno, "Failed to set FD nonblocking"); 746 goto failed; 747 } 748 } 749 options.opaque = (void *)(uintptr_t)vhostfd; 750 options.nvqs = 2; 751 options.feature_bits = kernel_feature_bits; 752 options.get_acked_features = NULL; 753 options.save_acked_features = NULL; 754 options.max_tx_queue_size = 0; 755 options.is_vhost_user = false; 756 757 s->vhost_net = vhost_net_init(&options); 758 if (!s->vhost_net) { 759 error_setg(errp, 760 "vhost-net requested but could not be initialized"); 761 goto failed; 762 } 763 } else if (vhostfdname) { 764 error_setg(errp, "vhostfd(s)= is not valid without vhost"); 765 goto failed; 766 } 767 768 return; 769 770 failed: 771 qemu_del_net_client(&s->nc); 772 } 773 774 static int get_fds(char *str, char *fds[], int max) 775 { 776 char *ptr = str, *this; 777 size_t len = strlen(str); 778 int i = 0; 779 780 while (i < max && ptr < str + len) { 781 this = strchr(ptr, ':'); 782 783 if (this == NULL) { 784 fds[i] = g_strdup(ptr); 785 } else { 786 fds[i] = g_strndup(ptr, this - ptr); 787 } 788 789 i++; 790 if (this == NULL) { 791 break; 792 } else { 793 ptr = this + 1; 794 } 795 } 796 797 return i; 798 } 799 800 int net_init_tap(const Netdev *netdev, const char *name, 801 NetClientState *peer, Error **errp) 802 { 803 const NetdevTapOptions *tap; 804 int fd, vnet_hdr = 0, i = 0, queues; 805 /* for the no-fd, no-helper case */ 806 const char *script; 807 const char *downscript; 808 Error *err = NULL; 809 const char *vhostfdname; 810 char ifname[128]; 811 int ret = 0; 812 813 assert(netdev->type == NET_CLIENT_DRIVER_TAP); 814 tap = &netdev->u.tap; 815 queues = tap->has_queues ? tap->queues : 1; 816 vhostfdname = tap->vhostfd; 817 script = tap->script; 818 downscript = tap->downscript; 819 820 /* QEMU hubs do not support multiqueue tap, in this case peer is set. 821 * For -netdev, peer is always NULL. */ 822 if (peer && (tap->has_queues || tap->fds || tap->vhostfds)) { 823 error_setg(errp, "Multiqueue tap cannot be used with hubs"); 824 return -1; 825 } 826 827 if (tap->fd) { 828 if (tap->ifname || tap->script || tap->downscript || 829 tap->has_vnet_hdr || tap->helper || tap->has_queues || 830 tap->fds || tap->vhostfds) { 831 error_setg(errp, "ifname=, script=, downscript=, vnet_hdr=, " 832 "helper=, queues=, fds=, and vhostfds= " 833 "are invalid with fd="); 834 return -1; 835 } 836 837 fd = monitor_fd_param(monitor_cur(), tap->fd, errp); 838 if (fd == -1) { 839 return -1; 840 } 841 842 if (!g_unix_set_fd_nonblocking(fd, true, NULL)) { 843 error_setg_errno(errp, errno, "%s: Can't use file descriptor %d", 844 name, fd); 845 close(fd); 846 return -1; 847 } 848 849 vnet_hdr = tap_probe_vnet_hdr(fd, errp); 850 if (vnet_hdr < 0) { 851 close(fd); 852 return -1; 853 } 854 855 net_init_tap_one(tap, peer, "tap", name, NULL, 856 script, downscript, 857 vhostfdname, vnet_hdr, fd, &err); 858 if (err) { 859 error_propagate(errp, err); 860 close(fd); 861 return -1; 862 } 863 } else if (tap->fds) { 864 char **fds; 865 char **vhost_fds; 866 int nfds = 0, nvhosts = 0; 867 868 if (tap->ifname || tap->script || tap->downscript || 869 tap->has_vnet_hdr || tap->helper || tap->has_queues || 870 tap->vhostfd) { 871 error_setg(errp, "ifname=, script=, downscript=, vnet_hdr=, " 872 "helper=, queues=, and vhostfd= " 873 "are invalid with fds="); 874 return -1; 875 } 876 877 fds = g_new0(char *, MAX_TAP_QUEUES); 878 vhost_fds = g_new0(char *, MAX_TAP_QUEUES); 879 880 nfds = get_fds(tap->fds, fds, MAX_TAP_QUEUES); 881 if (tap->vhostfds) { 882 nvhosts = get_fds(tap->vhostfds, vhost_fds, MAX_TAP_QUEUES); 883 if (nfds != nvhosts) { 884 error_setg(errp, "The number of fds passed does not match " 885 "the number of vhostfds passed"); 886 ret = -1; 887 goto free_fail; 888 } 889 } 890 891 for (i = 0; i < nfds; i++) { 892 fd = monitor_fd_param(monitor_cur(), fds[i], errp); 893 if (fd == -1) { 894 ret = -1; 895 goto free_fail; 896 } 897 898 if (!g_unix_set_fd_nonblocking(fd, true, NULL)) { 899 ret = -1; 900 error_setg_errno(errp, errno, "%s: Can't use file descriptor %d", 901 name, fd); 902 goto free_fail; 903 } 904 905 if (i == 0) { 906 vnet_hdr = tap_probe_vnet_hdr(fd, errp); 907 if (vnet_hdr < 0) { 908 ret = -1; 909 goto free_fail; 910 } 911 } else if (vnet_hdr != tap_probe_vnet_hdr(fd, NULL)) { 912 error_setg(errp, 913 "vnet_hdr not consistent across given tap fds"); 914 ret = -1; 915 goto free_fail; 916 } 917 918 net_init_tap_one(tap, peer, "tap", name, ifname, 919 script, downscript, 920 tap->vhostfds ? vhost_fds[i] : NULL, 921 vnet_hdr, fd, &err); 922 if (err) { 923 error_propagate(errp, err); 924 ret = -1; 925 goto free_fail; 926 } 927 } 928 929 free_fail: 930 for (i = 0; i < nvhosts; i++) { 931 g_free(vhost_fds[i]); 932 } 933 for (i = 0; i < nfds; i++) { 934 g_free(fds[i]); 935 } 936 g_free(fds); 937 g_free(vhost_fds); 938 return ret; 939 } else if (tap->helper) { 940 if (tap->ifname || tap->script || tap->downscript || 941 tap->has_vnet_hdr || tap->has_queues || tap->vhostfds) { 942 error_setg(errp, "ifname=, script=, downscript=, vnet_hdr=, " 943 "queues=, and vhostfds= are invalid with helper="); 944 return -1; 945 } 946 947 fd = net_bridge_run_helper(tap->helper, 948 tap->br ?: DEFAULT_BRIDGE_INTERFACE, 949 errp); 950 if (fd == -1) { 951 return -1; 952 } 953 954 if (!g_unix_set_fd_nonblocking(fd, true, NULL)) { 955 error_setg_errno(errp, errno, "Failed to set FD nonblocking"); 956 return -1; 957 } 958 vnet_hdr = tap_probe_vnet_hdr(fd, errp); 959 if (vnet_hdr < 0) { 960 close(fd); 961 return -1; 962 } 963 964 net_init_tap_one(tap, peer, "bridge", name, ifname, 965 script, downscript, vhostfdname, 966 vnet_hdr, fd, &err); 967 if (err) { 968 error_propagate(errp, err); 969 close(fd); 970 return -1; 971 } 972 } else { 973 g_autofree char *default_script = NULL; 974 g_autofree char *default_downscript = NULL; 975 if (tap->vhostfds) { 976 error_setg(errp, "vhostfds= is invalid if fds= wasn't specified"); 977 return -1; 978 } 979 980 if (!script) { 981 script = default_script = get_relocated_path(DEFAULT_NETWORK_SCRIPT); 982 } 983 if (!downscript) { 984 downscript = default_downscript = 985 get_relocated_path(DEFAULT_NETWORK_DOWN_SCRIPT); 986 } 987 988 if (tap->ifname) { 989 pstrcpy(ifname, sizeof ifname, tap->ifname); 990 } else { 991 ifname[0] = '\0'; 992 } 993 994 for (i = 0; i < queues; i++) { 995 fd = net_tap_init(tap, &vnet_hdr, i >= 1 ? "no" : script, 996 ifname, sizeof ifname, queues > 1, errp); 997 if (fd == -1) { 998 return -1; 999 } 1000 1001 if (queues > 1 && i == 0 && !tap->ifname) { 1002 if (tap_fd_get_ifname(fd, ifname)) { 1003 error_setg(errp, "Fail to get ifname"); 1004 close(fd); 1005 return -1; 1006 } 1007 } 1008 1009 net_init_tap_one(tap, peer, "tap", name, ifname, 1010 i >= 1 ? "no" : script, 1011 i >= 1 ? "no" : downscript, 1012 vhostfdname, vnet_hdr, fd, &err); 1013 if (err) { 1014 error_propagate(errp, err); 1015 close(fd); 1016 return -1; 1017 } 1018 } 1019 } 1020 1021 return 0; 1022 } 1023 1024 int tap_enable(NetClientState *nc) 1025 { 1026 TAPState *s = DO_UPCAST(TAPState, nc, nc); 1027 int ret; 1028 1029 if (s->enabled) { 1030 return 0; 1031 } else { 1032 ret = tap_fd_enable(s->fd); 1033 if (ret == 0) { 1034 s->enabled = true; 1035 tap_update_fd_handler(s); 1036 } 1037 return ret; 1038 } 1039 } 1040 1041 int tap_disable(NetClientState *nc) 1042 { 1043 TAPState *s = DO_UPCAST(TAPState, nc, nc); 1044 int ret; 1045 1046 if (s->enabled == 0) { 1047 return 0; 1048 } else { 1049 ret = tap_fd_disable(s->fd); 1050 if (ret == 0) { 1051 qemu_purge_queued_packets(nc); 1052 s->enabled = false; 1053 tap_update_fd_handler(s); 1054 } 1055 return ret; 1056 } 1057 } 1058