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