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/net.h" 36 #include "clients.h" 37 #include "monitor/monitor.h" 38 #include "sysemu/sysemu.h" 39 #include "qapi/error.h" 40 #include "qemu-common.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 enabled; 61 VHostNetState *vhost_net; 62 unsigned host_vnet_hdr_len; 63 Notifier exit; 64 } TAPState; 65 66 static void launch_script(const char *setup_script, const char *ifname, 67 int fd, Error **errp); 68 69 static void tap_send(void *opaque); 70 static void tap_writable(void *opaque); 71 72 static void tap_update_fd_handler(TAPState *s) 73 { 74 qemu_set_fd_handler(s->fd, 75 s->read_poll && s->enabled ? tap_send : NULL, 76 s->write_poll && s->enabled ? tap_writable : NULL, 77 s); 78 } 79 80 static void tap_read_poll(TAPState *s, bool enable) 81 { 82 s->read_poll = enable; 83 tap_update_fd_handler(s); 84 } 85 86 static void tap_write_poll(TAPState *s, bool enable) 87 { 88 s->write_poll = enable; 89 tap_update_fd_handler(s); 90 } 91 92 static void tap_writable(void *opaque) 93 { 94 TAPState *s = opaque; 95 96 tap_write_poll(s, false); 97 98 qemu_flush_queued_packets(&s->nc); 99 } 100 101 static ssize_t tap_write_packet(TAPState *s, const struct iovec *iov, int iovcnt) 102 { 103 ssize_t len; 104 105 do { 106 len = writev(s->fd, iov, iovcnt); 107 } while (len == -1 && errno == EINTR); 108 109 if (len == -1 && errno == EAGAIN) { 110 tap_write_poll(s, true); 111 return 0; 112 } 113 114 return len; 115 } 116 117 static ssize_t tap_receive_iov(NetClientState *nc, const struct iovec *iov, 118 int iovcnt) 119 { 120 TAPState *s = DO_UPCAST(TAPState, nc, nc); 121 const struct iovec *iovp = iov; 122 struct iovec iov_copy[iovcnt + 1]; 123 struct virtio_net_hdr_mrg_rxbuf hdr = { }; 124 125 if (s->host_vnet_hdr_len && !s->using_vnet_hdr) { 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_raw(NetClientState *nc, const uint8_t *buf, size_t size) 137 { 138 TAPState *s = DO_UPCAST(TAPState, nc, nc); 139 struct iovec iov[2]; 140 int iovcnt = 0; 141 struct virtio_net_hdr_mrg_rxbuf hdr = { }; 142 143 if (s->host_vnet_hdr_len) { 144 iov[iovcnt].iov_base = &hdr; 145 iov[iovcnt].iov_len = s->host_vnet_hdr_len; 146 iovcnt++; 147 } 148 149 iov[iovcnt].iov_base = (char *)buf; 150 iov[iovcnt].iov_len = size; 151 iovcnt++; 152 153 return tap_write_packet(s, iov, iovcnt); 154 } 155 156 static ssize_t tap_receive(NetClientState *nc, const uint8_t *buf, size_t size) 157 { 158 TAPState *s = DO_UPCAST(TAPState, nc, nc); 159 struct iovec iov[1]; 160 161 if (s->host_vnet_hdr_len && !s->using_vnet_hdr) { 162 return tap_receive_raw(nc, buf, size); 163 } 164 165 iov[0].iov_base = (char *)buf; 166 iov[0].iov_len = size; 167 168 return tap_write_packet(s, iov, 1); 169 } 170 171 #ifndef __sun__ 172 ssize_t tap_read_packet(int tapfd, uint8_t *buf, int maxlen) 173 { 174 return read(tapfd, buf, maxlen); 175 } 176 #endif 177 178 static void tap_send_completed(NetClientState *nc, ssize_t len) 179 { 180 TAPState *s = DO_UPCAST(TAPState, nc, nc); 181 tap_read_poll(s, true); 182 } 183 184 static void tap_send(void *opaque) 185 { 186 TAPState *s = opaque; 187 int size; 188 int packets = 0; 189 190 while (true) { 191 uint8_t *buf = s->buf; 192 193 size = tap_read_packet(s->fd, s->buf, sizeof(s->buf)); 194 if (size <= 0) { 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 size = qemu_send_packet_async(&s->nc, buf, size, tap_send_completed); 204 if (size == 0) { 205 tap_read_poll(s, false); 206 break; 207 } else if (size < 0) { 208 break; 209 } 210 211 /* 212 * When the host keeps receiving more packets while tap_send() is 213 * running we can hog the QEMU global mutex. Limit the number of 214 * packets that are processed per tap_send() callback to prevent 215 * stalling the guest. 216 */ 217 packets++; 218 if (packets >= 50) { 219 break; 220 } 221 } 222 } 223 224 static bool tap_has_ufo(NetClientState *nc) 225 { 226 TAPState *s = DO_UPCAST(TAPState, nc, nc); 227 228 assert(nc->info->type == NET_CLIENT_DRIVER_TAP); 229 230 return s->has_ufo; 231 } 232 233 static bool tap_has_vnet_hdr(NetClientState *nc) 234 { 235 TAPState *s = DO_UPCAST(TAPState, nc, nc); 236 237 assert(nc->info->type == NET_CLIENT_DRIVER_TAP); 238 239 return !!s->host_vnet_hdr_len; 240 } 241 242 static bool tap_has_vnet_hdr_len(NetClientState *nc, int len) 243 { 244 TAPState *s = DO_UPCAST(TAPState, nc, nc); 245 246 assert(nc->info->type == NET_CLIENT_DRIVER_TAP); 247 248 return !!tap_probe_vnet_hdr_len(s->fd, len); 249 } 250 251 static void tap_set_vnet_hdr_len(NetClientState *nc, int len) 252 { 253 TAPState *s = DO_UPCAST(TAPState, nc, nc); 254 255 assert(nc->info->type == NET_CLIENT_DRIVER_TAP); 256 assert(len == sizeof(struct virtio_net_hdr_mrg_rxbuf) || 257 len == sizeof(struct virtio_net_hdr)); 258 259 tap_fd_set_vnet_hdr_len(s->fd, len); 260 s->host_vnet_hdr_len = len; 261 } 262 263 static void tap_using_vnet_hdr(NetClientState *nc, bool using_vnet_hdr) 264 { 265 TAPState *s = DO_UPCAST(TAPState, nc, nc); 266 267 assert(nc->info->type == NET_CLIENT_DRIVER_TAP); 268 assert(!!s->host_vnet_hdr_len == using_vnet_hdr); 269 270 s->using_vnet_hdr = using_vnet_hdr; 271 } 272 273 static int tap_set_vnet_le(NetClientState *nc, bool is_le) 274 { 275 TAPState *s = DO_UPCAST(TAPState, nc, nc); 276 277 return tap_fd_set_vnet_le(s->fd, is_le); 278 } 279 280 static int tap_set_vnet_be(NetClientState *nc, bool is_be) 281 { 282 TAPState *s = DO_UPCAST(TAPState, nc, nc); 283 284 return tap_fd_set_vnet_be(s->fd, is_be); 285 } 286 287 static void tap_set_offload(NetClientState *nc, int csum, int tso4, 288 int tso6, int ecn, int ufo) 289 { 290 TAPState *s = DO_UPCAST(TAPState, nc, nc); 291 if (s->fd < 0) { 292 return; 293 } 294 295 tap_fd_set_offload(s->fd, csum, tso4, tso6, ecn, ufo); 296 } 297 298 static void tap_exit_notify(Notifier *notifier, void *data) 299 { 300 TAPState *s = container_of(notifier, TAPState, exit); 301 Error *err = NULL; 302 303 if (s->down_script[0]) { 304 launch_script(s->down_script, s->down_script_arg, s->fd, &err); 305 if (err) { 306 error_report_err(err); 307 } 308 } 309 } 310 311 static void tap_cleanup(NetClientState *nc) 312 { 313 TAPState *s = DO_UPCAST(TAPState, nc, nc); 314 315 if (s->vhost_net) { 316 vhost_net_cleanup(s->vhost_net); 317 g_free(s->vhost_net); 318 s->vhost_net = NULL; 319 } 320 321 qemu_purge_queued_packets(nc); 322 323 tap_exit_notify(&s->exit, NULL); 324 qemu_remove_exit_notifier(&s->exit); 325 326 tap_read_poll(s, false); 327 tap_write_poll(s, false); 328 close(s->fd); 329 s->fd = -1; 330 } 331 332 static void tap_poll(NetClientState *nc, bool enable) 333 { 334 TAPState *s = DO_UPCAST(TAPState, nc, nc); 335 tap_read_poll(s, enable); 336 tap_write_poll(s, enable); 337 } 338 339 int tap_get_fd(NetClientState *nc) 340 { 341 TAPState *s = DO_UPCAST(TAPState, nc, nc); 342 assert(nc->info->type == NET_CLIENT_DRIVER_TAP); 343 return s->fd; 344 } 345 346 /* fd support */ 347 348 static NetClientInfo net_tap_info = { 349 .type = NET_CLIENT_DRIVER_TAP, 350 .size = sizeof(TAPState), 351 .receive = tap_receive, 352 .receive_raw = tap_receive_raw, 353 .receive_iov = tap_receive_iov, 354 .poll = tap_poll, 355 .cleanup = tap_cleanup, 356 .has_ufo = tap_has_ufo, 357 .has_vnet_hdr = tap_has_vnet_hdr, 358 .has_vnet_hdr_len = tap_has_vnet_hdr_len, 359 .using_vnet_hdr = tap_using_vnet_hdr, 360 .set_offload = tap_set_offload, 361 .set_vnet_hdr_len = tap_set_vnet_hdr_len, 362 .set_vnet_le = tap_set_vnet_le, 363 .set_vnet_be = tap_set_vnet_be, 364 }; 365 366 static TAPState *net_tap_fd_init(NetClientState *peer, 367 const char *model, 368 const char *name, 369 int fd, 370 int vnet_hdr) 371 { 372 NetClientState *nc; 373 TAPState *s; 374 375 nc = qemu_new_net_client(&net_tap_info, peer, model, name); 376 377 s = DO_UPCAST(TAPState, nc, nc); 378 379 s->fd = fd; 380 s->host_vnet_hdr_len = vnet_hdr ? sizeof(struct virtio_net_hdr) : 0; 381 s->using_vnet_hdr = false; 382 s->has_ufo = tap_probe_has_ufo(s->fd); 383 s->enabled = true; 384 tap_set_offload(&s->nc, 0, 0, 0, 0, 0); 385 /* 386 * Make sure host header length is set correctly in tap: 387 * it might have been modified by another instance of qemu. 388 */ 389 if (tap_probe_vnet_hdr_len(s->fd, s->host_vnet_hdr_len)) { 390 tap_fd_set_vnet_hdr_len(s->fd, s->host_vnet_hdr_len); 391 } 392 tap_read_poll(s, true); 393 s->vhost_net = NULL; 394 395 s->exit.notify = tap_exit_notify; 396 qemu_add_exit_notifier(&s->exit); 397 398 return s; 399 } 400 401 static void launch_script(const char *setup_script, const char *ifname, 402 int fd, Error **errp) 403 { 404 int pid, status; 405 char *args[3]; 406 char **parg; 407 408 /* try to launch network script */ 409 pid = fork(); 410 if (pid < 0) { 411 error_setg_errno(errp, errno, "could not launch network script %s", 412 setup_script); 413 return; 414 } 415 if (pid == 0) { 416 int open_max = sysconf(_SC_OPEN_MAX), i; 417 418 for (i = 3; i < open_max; i++) { 419 if (i != fd) { 420 close(i); 421 } 422 } 423 parg = args; 424 *parg++ = (char *)setup_script; 425 *parg++ = (char *)ifname; 426 *parg = NULL; 427 execv(setup_script, args); 428 _exit(1); 429 } else { 430 while (waitpid(pid, &status, 0) != pid) { 431 /* loop */ 432 } 433 434 if (WIFEXITED(status) && WEXITSTATUS(status) == 0) { 435 return; 436 } 437 error_setg(errp, "network script %s failed with status %d", 438 setup_script, status); 439 } 440 } 441 442 static int recv_fd(int c) 443 { 444 int fd; 445 uint8_t msgbuf[CMSG_SPACE(sizeof(fd))]; 446 struct msghdr msg = { 447 .msg_control = msgbuf, 448 .msg_controllen = sizeof(msgbuf), 449 }; 450 struct cmsghdr *cmsg; 451 struct iovec iov; 452 uint8_t req[1]; 453 ssize_t len; 454 455 cmsg = CMSG_FIRSTHDR(&msg); 456 cmsg->cmsg_level = SOL_SOCKET; 457 cmsg->cmsg_type = SCM_RIGHTS; 458 cmsg->cmsg_len = CMSG_LEN(sizeof(fd)); 459 msg.msg_controllen = cmsg->cmsg_len; 460 461 iov.iov_base = req; 462 iov.iov_len = sizeof(req); 463 464 msg.msg_iov = &iov; 465 msg.msg_iovlen = 1; 466 467 len = recvmsg(c, &msg, 0); 468 if (len > 0) { 469 memcpy(&fd, CMSG_DATA(cmsg), sizeof(fd)); 470 return fd; 471 } 472 473 return len; 474 } 475 476 static int net_bridge_run_helper(const char *helper, const char *bridge, 477 Error **errp) 478 { 479 sigset_t oldmask, mask; 480 int pid, status; 481 char *args[5]; 482 char **parg; 483 int sv[2]; 484 485 sigemptyset(&mask); 486 sigaddset(&mask, SIGCHLD); 487 sigprocmask(SIG_BLOCK, &mask, &oldmask); 488 489 if (socketpair(PF_UNIX, SOCK_STREAM, 0, sv) == -1) { 490 error_setg_errno(errp, errno, "socketpair() failed"); 491 return -1; 492 } 493 494 /* try to launch bridge helper */ 495 pid = fork(); 496 if (pid < 0) { 497 error_setg_errno(errp, errno, "Can't fork bridge helper"); 498 return -1; 499 } 500 if (pid == 0) { 501 int open_max = sysconf(_SC_OPEN_MAX), i; 502 char *fd_buf = NULL; 503 char *br_buf = NULL; 504 char *helper_cmd = NULL; 505 506 for (i = 3; i < open_max; i++) { 507 if (i != sv[1]) { 508 close(i); 509 } 510 } 511 512 fd_buf = g_strdup_printf("%s%d", "--fd=", sv[1]); 513 514 if (strrchr(helper, ' ') || strrchr(helper, '\t')) { 515 /* assume helper is a command */ 516 517 if (strstr(helper, "--br=") == NULL) { 518 br_buf = g_strdup_printf("%s%s", "--br=", bridge); 519 } 520 521 helper_cmd = g_strdup_printf("%s %s %s %s", helper, 522 "--use-vnet", fd_buf, br_buf ? br_buf : ""); 523 524 parg = args; 525 *parg++ = (char *)"sh"; 526 *parg++ = (char *)"-c"; 527 *parg++ = helper_cmd; 528 *parg++ = NULL; 529 530 execv("/bin/sh", args); 531 g_free(helper_cmd); 532 } else { 533 /* assume helper is just the executable path name */ 534 535 br_buf = g_strdup_printf("%s%s", "--br=", bridge); 536 537 parg = args; 538 *parg++ = (char *)helper; 539 *parg++ = (char *)"--use-vnet"; 540 *parg++ = fd_buf; 541 *parg++ = br_buf; 542 *parg++ = NULL; 543 544 execv(helper, args); 545 } 546 g_free(fd_buf); 547 g_free(br_buf); 548 _exit(1); 549 550 } else { 551 int fd; 552 int saved_errno; 553 554 close(sv[1]); 555 556 do { 557 fd = recv_fd(sv[0]); 558 } while (fd == -1 && errno == EINTR); 559 saved_errno = errno; 560 561 close(sv[0]); 562 563 while (waitpid(pid, &status, 0) != pid) { 564 /* loop */ 565 } 566 sigprocmask(SIG_SETMASK, &oldmask, NULL); 567 if (fd < 0) { 568 error_setg_errno(errp, saved_errno, 569 "failed to recv file descriptor"); 570 return -1; 571 } 572 if (!WIFEXITED(status) || WEXITSTATUS(status) != 0) { 573 error_setg(errp, "bridge helper failed"); 574 return -1; 575 } 576 return fd; 577 } 578 } 579 580 int net_init_bridge(const Netdev *netdev, const char *name, 581 NetClientState *peer, Error **errp) 582 { 583 const NetdevBridgeOptions *bridge; 584 const char *helper, *br; 585 TAPState *s; 586 int fd, vnet_hdr; 587 588 assert(netdev->type == NET_CLIENT_DRIVER_BRIDGE); 589 bridge = &netdev->u.bridge; 590 591 helper = bridge->has_helper ? bridge->helper : DEFAULT_BRIDGE_HELPER; 592 br = bridge->has_br ? bridge->br : DEFAULT_BRIDGE_INTERFACE; 593 594 fd = net_bridge_run_helper(helper, br, errp); 595 if (fd == -1) { 596 return -1; 597 } 598 599 qemu_set_nonblock(fd); 600 vnet_hdr = tap_probe_vnet_hdr(fd); 601 s = net_tap_fd_init(peer, "bridge", name, fd, vnet_hdr); 602 603 snprintf(s->nc.info_str, sizeof(s->nc.info_str), "helper=%s,br=%s", helper, 604 br); 605 606 return 0; 607 } 608 609 static int net_tap_init(const NetdevTapOptions *tap, int *vnet_hdr, 610 const char *setup_script, char *ifname, 611 size_t ifname_sz, int mq_required, Error **errp) 612 { 613 Error *err = NULL; 614 int fd, vnet_hdr_required; 615 616 if (tap->has_vnet_hdr) { 617 *vnet_hdr = tap->vnet_hdr; 618 vnet_hdr_required = *vnet_hdr; 619 } else { 620 *vnet_hdr = 1; 621 vnet_hdr_required = 0; 622 } 623 624 TFR(fd = tap_open(ifname, ifname_sz, vnet_hdr, vnet_hdr_required, 625 mq_required, errp)); 626 if (fd < 0) { 627 return -1; 628 } 629 630 if (setup_script && 631 setup_script[0] != '\0' && 632 strcmp(setup_script, "no") != 0) { 633 launch_script(setup_script, ifname, fd, &err); 634 if (err) { 635 error_propagate(errp, err); 636 close(fd); 637 return -1; 638 } 639 } 640 641 return fd; 642 } 643 644 #define MAX_TAP_QUEUES 1024 645 646 static void net_init_tap_one(const NetdevTapOptions *tap, NetClientState *peer, 647 const char *model, const char *name, 648 const char *ifname, const char *script, 649 const char *downscript, const char *vhostfdname, 650 int vnet_hdr, int fd, Error **errp) 651 { 652 Error *err = NULL; 653 TAPState *s = net_tap_fd_init(peer, model, name, fd, vnet_hdr); 654 int vhostfd; 655 656 tap_set_sndbuf(s->fd, tap, &err); 657 if (err) { 658 error_propagate(errp, err); 659 return; 660 } 661 662 if (tap->has_fd || tap->has_fds) { 663 snprintf(s->nc.info_str, sizeof(s->nc.info_str), "fd=%d", fd); 664 } else if (tap->has_helper) { 665 snprintf(s->nc.info_str, sizeof(s->nc.info_str), "helper=%s", 666 tap->helper); 667 } else { 668 snprintf(s->nc.info_str, sizeof(s->nc.info_str), 669 "ifname=%s,script=%s,downscript=%s", ifname, script, 670 downscript); 671 672 if (strcmp(downscript, "no") != 0) { 673 snprintf(s->down_script, sizeof(s->down_script), "%s", downscript); 674 snprintf(s->down_script_arg, sizeof(s->down_script_arg), 675 "%s", ifname); 676 } 677 } 678 679 if (tap->has_vhost ? tap->vhost : 680 vhostfdname || (tap->has_vhostforce && tap->vhostforce)) { 681 VhostNetOptions options; 682 683 options.backend_type = VHOST_BACKEND_TYPE_KERNEL; 684 options.net_backend = &s->nc; 685 if (tap->has_poll_us) { 686 options.busyloop_timeout = tap->poll_us; 687 } else { 688 options.busyloop_timeout = 0; 689 } 690 691 if (vhostfdname) { 692 vhostfd = monitor_fd_param(cur_mon, vhostfdname, &err); 693 if (vhostfd == -1) { 694 if (tap->has_vhostforce && tap->vhostforce) { 695 error_propagate(errp, err); 696 } else { 697 warn_report_err(err); 698 } 699 return; 700 } 701 qemu_set_nonblock(vhostfd); 702 } else { 703 vhostfd = open("/dev/vhost-net", O_RDWR); 704 if (vhostfd < 0) { 705 if (tap->has_vhostforce && tap->vhostforce) { 706 error_setg_errno(errp, errno, 707 "tap: open vhost char device failed"); 708 } else { 709 warn_report("tap: open vhost char device failed: %s", 710 strerror(errno)); 711 } 712 return; 713 } 714 qemu_set_nonblock(vhostfd); 715 } 716 options.opaque = (void *)(uintptr_t)vhostfd; 717 718 s->vhost_net = vhost_net_init(&options); 719 if (!s->vhost_net) { 720 if (tap->has_vhostforce && tap->vhostforce) { 721 error_setg(errp, VHOST_NET_INIT_FAILED); 722 } else { 723 warn_report(VHOST_NET_INIT_FAILED); 724 } 725 return; 726 } 727 } else if (vhostfdname) { 728 error_setg(errp, "vhostfd(s)= is not valid without vhost"); 729 } 730 } 731 732 static int get_fds(char *str, char *fds[], int max) 733 { 734 char *ptr = str, *this; 735 size_t len = strlen(str); 736 int i = 0; 737 738 while (i < max && ptr < str + len) { 739 this = strchr(ptr, ':'); 740 741 if (this == NULL) { 742 fds[i] = g_strdup(ptr); 743 } else { 744 fds[i] = g_strndup(ptr, this - ptr); 745 } 746 747 i++; 748 if (this == NULL) { 749 break; 750 } else { 751 ptr = this + 1; 752 } 753 } 754 755 return i; 756 } 757 758 int net_init_tap(const Netdev *netdev, const char *name, 759 NetClientState *peer, Error **errp) 760 { 761 const NetdevTapOptions *tap; 762 int fd, vnet_hdr = 0, i = 0, queues; 763 /* for the no-fd, no-helper case */ 764 const char *script = NULL; /* suppress wrong "uninit'd use" gcc warning */ 765 const char *downscript = NULL; 766 Error *err = NULL; 767 const char *vhostfdname; 768 char ifname[128]; 769 770 assert(netdev->type == NET_CLIENT_DRIVER_TAP); 771 tap = &netdev->u.tap; 772 queues = tap->has_queues ? tap->queues : 1; 773 vhostfdname = tap->has_vhostfd ? tap->vhostfd : NULL; 774 775 /* QEMU hubs do not support multiqueue tap, in this case peer is set. 776 * For -netdev, peer is always NULL. */ 777 if (peer && (tap->has_queues || tap->has_fds || tap->has_vhostfds)) { 778 error_setg(errp, "Multiqueue tap cannot be used with hubs"); 779 return -1; 780 } 781 782 if (tap->has_fd) { 783 if (tap->has_ifname || tap->has_script || tap->has_downscript || 784 tap->has_vnet_hdr || tap->has_helper || tap->has_queues || 785 tap->has_fds || tap->has_vhostfds) { 786 error_setg(errp, "ifname=, script=, downscript=, vnet_hdr=, " 787 "helper=, queues=, fds=, and vhostfds= " 788 "are invalid with fd="); 789 return -1; 790 } 791 792 fd = monitor_fd_param(cur_mon, tap->fd, &err); 793 if (fd == -1) { 794 error_propagate(errp, err); 795 return -1; 796 } 797 798 qemu_set_nonblock(fd); 799 800 vnet_hdr = tap_probe_vnet_hdr(fd); 801 802 net_init_tap_one(tap, peer, "tap", name, NULL, 803 script, downscript, 804 vhostfdname, vnet_hdr, fd, &err); 805 if (err) { 806 error_propagate(errp, err); 807 return -1; 808 } 809 } else if (tap->has_fds) { 810 char **fds; 811 char **vhost_fds; 812 int nfds = 0, nvhosts = 0; 813 int ret = 0; 814 815 if (tap->has_ifname || tap->has_script || tap->has_downscript || 816 tap->has_vnet_hdr || tap->has_helper || tap->has_queues || 817 tap->has_vhostfd) { 818 error_setg(errp, "ifname=, script=, downscript=, vnet_hdr=, " 819 "helper=, queues=, and vhostfd= " 820 "are invalid with fds="); 821 return -1; 822 } 823 824 fds = g_new0(char *, MAX_TAP_QUEUES); 825 vhost_fds = g_new0(char *, MAX_TAP_QUEUES); 826 827 nfds = get_fds(tap->fds, fds, MAX_TAP_QUEUES); 828 if (tap->has_vhostfds) { 829 nvhosts = get_fds(tap->vhostfds, vhost_fds, MAX_TAP_QUEUES); 830 if (nfds != nvhosts) { 831 error_setg(errp, "The number of fds passed does not match " 832 "the number of vhostfds passed"); 833 ret = -1; 834 goto free_fail; 835 } 836 } 837 838 for (i = 0; i < nfds; i++) { 839 fd = monitor_fd_param(cur_mon, fds[i], &err); 840 if (fd == -1) { 841 error_propagate(errp, err); 842 ret = -1; 843 goto free_fail; 844 } 845 846 qemu_set_nonblock(fd); 847 848 if (i == 0) { 849 vnet_hdr = tap_probe_vnet_hdr(fd); 850 } else if (vnet_hdr != tap_probe_vnet_hdr(fd)) { 851 error_setg(errp, 852 "vnet_hdr not consistent across given tap fds"); 853 ret = -1; 854 goto free_fail; 855 } 856 857 net_init_tap_one(tap, peer, "tap", name, ifname, 858 script, downscript, 859 tap->has_vhostfds ? vhost_fds[i] : NULL, 860 vnet_hdr, fd, &err); 861 if (err) { 862 error_propagate(errp, err); 863 ret = -1; 864 goto free_fail; 865 } 866 } 867 868 free_fail: 869 for (i = 0; i < nvhosts; i++) { 870 g_free(vhost_fds[i]); 871 } 872 for (i = 0; i < nfds; i++) { 873 g_free(fds[i]); 874 } 875 g_free(fds); 876 g_free(vhost_fds); 877 return ret; 878 } else if (tap->has_helper) { 879 if (tap->has_ifname || tap->has_script || tap->has_downscript || 880 tap->has_vnet_hdr || tap->has_queues || tap->has_vhostfds) { 881 error_setg(errp, "ifname=, script=, downscript=, vnet_hdr=, " 882 "queues=, and vhostfds= are invalid with helper="); 883 return -1; 884 } 885 886 fd = net_bridge_run_helper(tap->helper, 887 tap->has_br ? 888 tap->br : DEFAULT_BRIDGE_INTERFACE, 889 errp); 890 if (fd == -1) { 891 return -1; 892 } 893 894 qemu_set_nonblock(fd); 895 vnet_hdr = tap_probe_vnet_hdr(fd); 896 897 net_init_tap_one(tap, peer, "bridge", name, ifname, 898 script, downscript, vhostfdname, 899 vnet_hdr, fd, &err); 900 if (err) { 901 error_propagate(errp, err); 902 close(fd); 903 return -1; 904 } 905 } else { 906 if (tap->has_vhostfds) { 907 error_setg(errp, "vhostfds= is invalid if fds= wasn't specified"); 908 return -1; 909 } 910 script = tap->has_script ? tap->script : DEFAULT_NETWORK_SCRIPT; 911 downscript = tap->has_downscript ? tap->downscript : 912 DEFAULT_NETWORK_DOWN_SCRIPT; 913 914 if (tap->has_ifname) { 915 pstrcpy(ifname, sizeof ifname, tap->ifname); 916 } else { 917 ifname[0] = '\0'; 918 } 919 920 for (i = 0; i < queues; i++) { 921 fd = net_tap_init(tap, &vnet_hdr, i >= 1 ? "no" : script, 922 ifname, sizeof ifname, queues > 1, errp); 923 if (fd == -1) { 924 return -1; 925 } 926 927 if (queues > 1 && i == 0 && !tap->has_ifname) { 928 if (tap_fd_get_ifname(fd, ifname)) { 929 error_setg(errp, "Fail to get ifname"); 930 close(fd); 931 return -1; 932 } 933 } 934 935 net_init_tap_one(tap, peer, "tap", name, ifname, 936 i >= 1 ? "no" : script, 937 i >= 1 ? "no" : downscript, 938 vhostfdname, vnet_hdr, fd, &err); 939 if (err) { 940 error_propagate(errp, err); 941 close(fd); 942 return -1; 943 } 944 } 945 } 946 947 return 0; 948 } 949 950 VHostNetState *tap_get_vhost_net(NetClientState *nc) 951 { 952 TAPState *s = DO_UPCAST(TAPState, nc, nc); 953 assert(nc->info->type == NET_CLIENT_DRIVER_TAP); 954 return s->vhost_net; 955 } 956 957 int tap_enable(NetClientState *nc) 958 { 959 TAPState *s = DO_UPCAST(TAPState, nc, nc); 960 int ret; 961 962 if (s->enabled) { 963 return 0; 964 } else { 965 ret = tap_fd_enable(s->fd); 966 if (ret == 0) { 967 s->enabled = true; 968 tap_update_fd_handler(s); 969 } 970 return ret; 971 } 972 } 973 974 int tap_disable(NetClientState *nc) 975 { 976 TAPState *s = DO_UPCAST(TAPState, nc, nc); 977 int ret; 978 979 if (s->enabled == 0) { 980 return 0; 981 } else { 982 ret = tap_fd_disable(s->fd); 983 if (ret == 0) { 984 qemu_purge_queued_packets(nc); 985 s->enabled = false; 986 tap_update_fd_handler(s); 987 } 988 return ret; 989 } 990 } 991