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 44 #include "net/tap.h" 45 46 #include "net/vhost_net.h" 47 48 typedef struct TAPState { 49 NetClientState nc; 50 int fd; 51 char down_script[1024]; 52 char down_script_arg[128]; 53 uint8_t buf[NET_BUFSIZE]; 54 bool read_poll; 55 bool write_poll; 56 bool using_vnet_hdr; 57 bool has_ufo; 58 bool enabled; 59 VHostNetState *vhost_net; 60 unsigned host_vnet_hdr_len; 61 Notifier exit; 62 } TAPState; 63 64 static void launch_script(const char *setup_script, const char *ifname, 65 int fd, Error **errp); 66 67 static void tap_send(void *opaque); 68 static void tap_writable(void *opaque); 69 70 static void tap_update_fd_handler(TAPState *s) 71 { 72 qemu_set_fd_handler(s->fd, 73 s->read_poll && s->enabled ? tap_send : NULL, 74 s->write_poll && s->enabled ? tap_writable : NULL, 75 s); 76 } 77 78 static void tap_read_poll(TAPState *s, bool enable) 79 { 80 s->read_poll = enable; 81 tap_update_fd_handler(s); 82 } 83 84 static void tap_write_poll(TAPState *s, bool enable) 85 { 86 s->write_poll = enable; 87 tap_update_fd_handler(s); 88 } 89 90 static void tap_writable(void *opaque) 91 { 92 TAPState *s = opaque; 93 94 tap_write_poll(s, false); 95 96 qemu_flush_queued_packets(&s->nc); 97 } 98 99 static ssize_t tap_write_packet(TAPState *s, const struct iovec *iov, int iovcnt) 100 { 101 ssize_t len; 102 103 do { 104 len = writev(s->fd, iov, iovcnt); 105 } while (len == -1 && errno == EINTR); 106 107 if (len == -1 && errno == EAGAIN) { 108 tap_write_poll(s, true); 109 return 0; 110 } 111 112 return len; 113 } 114 115 static ssize_t tap_receive_iov(NetClientState *nc, const struct iovec *iov, 116 int iovcnt) 117 { 118 TAPState *s = DO_UPCAST(TAPState, nc, nc); 119 const struct iovec *iovp = iov; 120 struct iovec iov_copy[iovcnt + 1]; 121 struct virtio_net_hdr_mrg_rxbuf hdr = { }; 122 123 if (s->host_vnet_hdr_len && !s->using_vnet_hdr) { 124 iov_copy[0].iov_base = &hdr; 125 iov_copy[0].iov_len = s->host_vnet_hdr_len; 126 memcpy(&iov_copy[1], iov, iovcnt * sizeof(*iov)); 127 iovp = iov_copy; 128 iovcnt++; 129 } 130 131 return tap_write_packet(s, iovp, iovcnt); 132 } 133 134 static ssize_t tap_receive_raw(NetClientState *nc, const uint8_t *buf, size_t size) 135 { 136 TAPState *s = DO_UPCAST(TAPState, nc, nc); 137 struct iovec iov[2]; 138 int iovcnt = 0; 139 struct virtio_net_hdr_mrg_rxbuf hdr = { }; 140 141 if (s->host_vnet_hdr_len) { 142 iov[iovcnt].iov_base = &hdr; 143 iov[iovcnt].iov_len = s->host_vnet_hdr_len; 144 iovcnt++; 145 } 146 147 iov[iovcnt].iov_base = (char *)buf; 148 iov[iovcnt].iov_len = size; 149 iovcnt++; 150 151 return tap_write_packet(s, iov, iovcnt); 152 } 153 154 static ssize_t tap_receive(NetClientState *nc, const uint8_t *buf, size_t size) 155 { 156 TAPState *s = DO_UPCAST(TAPState, nc, nc); 157 struct iovec iov[1]; 158 159 if (s->host_vnet_hdr_len && !s->using_vnet_hdr) { 160 return tap_receive_raw(nc, buf, size); 161 } 162 163 iov[0].iov_base = (char *)buf; 164 iov[0].iov_len = size; 165 166 return tap_write_packet(s, iov, 1); 167 } 168 169 #ifndef __sun__ 170 ssize_t tap_read_packet(int tapfd, uint8_t *buf, int maxlen) 171 { 172 return read(tapfd, buf, maxlen); 173 } 174 #endif 175 176 static void tap_send_completed(NetClientState *nc, ssize_t len) 177 { 178 TAPState *s = DO_UPCAST(TAPState, nc, nc); 179 tap_read_poll(s, true); 180 } 181 182 static void tap_send(void *opaque) 183 { 184 TAPState *s = opaque; 185 int size; 186 int packets = 0; 187 188 while (true) { 189 uint8_t *buf = s->buf; 190 191 size = tap_read_packet(s->fd, s->buf, sizeof(s->buf)); 192 if (size <= 0) { 193 break; 194 } 195 196 if (s->host_vnet_hdr_len && !s->using_vnet_hdr) { 197 buf += s->host_vnet_hdr_len; 198 size -= s->host_vnet_hdr_len; 199 } 200 201 size = qemu_send_packet_async(&s->nc, buf, size, tap_send_completed); 202 if (size == 0) { 203 tap_read_poll(s, false); 204 break; 205 } else if (size < 0) { 206 break; 207 } 208 209 /* 210 * When the host keeps receiving more packets while tap_send() is 211 * running we can hog the QEMU global mutex. Limit the number of 212 * packets that are processed per tap_send() callback to prevent 213 * stalling the guest. 214 */ 215 packets++; 216 if (packets >= 50) { 217 break; 218 } 219 } 220 } 221 222 static bool tap_has_ufo(NetClientState *nc) 223 { 224 TAPState *s = DO_UPCAST(TAPState, nc, nc); 225 226 assert(nc->info->type == NET_CLIENT_DRIVER_TAP); 227 228 return s->has_ufo; 229 } 230 231 static bool tap_has_vnet_hdr(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->host_vnet_hdr_len; 238 } 239 240 static bool tap_has_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 return !!tap_probe_vnet_hdr_len(s->fd, len); 247 } 248 249 static void tap_set_vnet_hdr_len(NetClientState *nc, int len) 250 { 251 TAPState *s = DO_UPCAST(TAPState, nc, nc); 252 253 assert(nc->info->type == NET_CLIENT_DRIVER_TAP); 254 assert(len == sizeof(struct virtio_net_hdr_mrg_rxbuf) || 255 len == sizeof(struct virtio_net_hdr)); 256 257 tap_fd_set_vnet_hdr_len(s->fd, len); 258 s->host_vnet_hdr_len = len; 259 } 260 261 static void tap_using_vnet_hdr(NetClientState *nc, bool using_vnet_hdr) 262 { 263 TAPState *s = DO_UPCAST(TAPState, nc, nc); 264 265 assert(nc->info->type == NET_CLIENT_DRIVER_TAP); 266 assert(!!s->host_vnet_hdr_len == using_vnet_hdr); 267 268 s->using_vnet_hdr = using_vnet_hdr; 269 } 270 271 static int tap_set_vnet_le(NetClientState *nc, bool is_le) 272 { 273 TAPState *s = DO_UPCAST(TAPState, nc, nc); 274 275 return tap_fd_set_vnet_le(s->fd, is_le); 276 } 277 278 static int tap_set_vnet_be(NetClientState *nc, bool is_be) 279 { 280 TAPState *s = DO_UPCAST(TAPState, nc, nc); 281 282 return tap_fd_set_vnet_be(s->fd, is_be); 283 } 284 285 static void tap_set_offload(NetClientState *nc, int csum, int tso4, 286 int tso6, int ecn, int ufo) 287 { 288 TAPState *s = DO_UPCAST(TAPState, nc, nc); 289 if (s->fd < 0) { 290 return; 291 } 292 293 tap_fd_set_offload(s->fd, csum, tso4, tso6, ecn, ufo); 294 } 295 296 static void tap_exit_notify(Notifier *notifier, void *data) 297 { 298 TAPState *s = container_of(notifier, TAPState, exit); 299 Error *err = NULL; 300 301 if (s->down_script[0]) { 302 launch_script(s->down_script, s->down_script_arg, s->fd, &err); 303 if (err) { 304 error_report_err(err); 305 } 306 } 307 } 308 309 static void tap_cleanup(NetClientState *nc) 310 { 311 TAPState *s = DO_UPCAST(TAPState, nc, nc); 312 313 if (s->vhost_net) { 314 vhost_net_cleanup(s->vhost_net); 315 g_free(s->vhost_net); 316 s->vhost_net = NULL; 317 } 318 319 qemu_purge_queued_packets(nc); 320 321 tap_exit_notify(&s->exit, NULL); 322 qemu_remove_exit_notifier(&s->exit); 323 324 tap_read_poll(s, false); 325 tap_write_poll(s, false); 326 close(s->fd); 327 s->fd = -1; 328 } 329 330 static void tap_poll(NetClientState *nc, bool enable) 331 { 332 TAPState *s = DO_UPCAST(TAPState, nc, nc); 333 tap_read_poll(s, enable); 334 tap_write_poll(s, enable); 335 } 336 337 int tap_get_fd(NetClientState *nc) 338 { 339 TAPState *s = DO_UPCAST(TAPState, nc, nc); 340 assert(nc->info->type == NET_CLIENT_DRIVER_TAP); 341 return s->fd; 342 } 343 344 /* fd support */ 345 346 static NetClientInfo net_tap_info = { 347 .type = NET_CLIENT_DRIVER_TAP, 348 .size = sizeof(TAPState), 349 .receive = tap_receive, 350 .receive_raw = tap_receive_raw, 351 .receive_iov = tap_receive_iov, 352 .poll = tap_poll, 353 .cleanup = tap_cleanup, 354 .has_ufo = tap_has_ufo, 355 .has_vnet_hdr = tap_has_vnet_hdr, 356 .has_vnet_hdr_len = tap_has_vnet_hdr_len, 357 .using_vnet_hdr = tap_using_vnet_hdr, 358 .set_offload = tap_set_offload, 359 .set_vnet_hdr_len = tap_set_vnet_hdr_len, 360 .set_vnet_le = tap_set_vnet_le, 361 .set_vnet_be = tap_set_vnet_be, 362 }; 363 364 static TAPState *net_tap_fd_init(NetClientState *peer, 365 const char *model, 366 const char *name, 367 int fd, 368 int vnet_hdr) 369 { 370 NetClientState *nc; 371 TAPState *s; 372 373 nc = qemu_new_net_client(&net_tap_info, peer, model, name); 374 375 s = DO_UPCAST(TAPState, nc, nc); 376 377 s->fd = fd; 378 s->host_vnet_hdr_len = vnet_hdr ? sizeof(struct virtio_net_hdr) : 0; 379 s->using_vnet_hdr = false; 380 s->has_ufo = tap_probe_has_ufo(s->fd); 381 s->enabled = true; 382 tap_set_offload(&s->nc, 0, 0, 0, 0, 0); 383 /* 384 * Make sure host header length is set correctly in tap: 385 * it might have been modified by another instance of qemu. 386 */ 387 if (tap_probe_vnet_hdr_len(s->fd, s->host_vnet_hdr_len)) { 388 tap_fd_set_vnet_hdr_len(s->fd, s->host_vnet_hdr_len); 389 } 390 tap_read_poll(s, true); 391 s->vhost_net = NULL; 392 393 s->exit.notify = tap_exit_notify; 394 qemu_add_exit_notifier(&s->exit); 395 396 return s; 397 } 398 399 static void launch_script(const char *setup_script, const char *ifname, 400 int fd, Error **errp) 401 { 402 int pid, status; 403 char *args[3]; 404 char **parg; 405 406 /* try to launch network script */ 407 pid = fork(); 408 if (pid < 0) { 409 error_setg_errno(errp, errno, "could not launch network script %s", 410 setup_script); 411 return; 412 } 413 if (pid == 0) { 414 int open_max = sysconf(_SC_OPEN_MAX), i; 415 416 for (i = 3; i < open_max; i++) { 417 if (i != fd) { 418 close(i); 419 } 420 } 421 parg = args; 422 *parg++ = (char *)setup_script; 423 *parg++ = (char *)ifname; 424 *parg = NULL; 425 execv(setup_script, args); 426 _exit(1); 427 } else { 428 while (waitpid(pid, &status, 0) != pid) { 429 /* loop */ 430 } 431 432 if (WIFEXITED(status) && WEXITSTATUS(status) == 0) { 433 return; 434 } 435 error_setg(errp, "network script %s failed with status %d", 436 setup_script, status); 437 } 438 } 439 440 static int recv_fd(int c) 441 { 442 int fd; 443 uint8_t msgbuf[CMSG_SPACE(sizeof(fd))]; 444 struct msghdr msg = { 445 .msg_control = msgbuf, 446 .msg_controllen = sizeof(msgbuf), 447 }; 448 struct cmsghdr *cmsg; 449 struct iovec iov; 450 uint8_t req[1]; 451 ssize_t len; 452 453 cmsg = CMSG_FIRSTHDR(&msg); 454 cmsg->cmsg_level = SOL_SOCKET; 455 cmsg->cmsg_type = SCM_RIGHTS; 456 cmsg->cmsg_len = CMSG_LEN(sizeof(fd)); 457 msg.msg_controllen = cmsg->cmsg_len; 458 459 iov.iov_base = req; 460 iov.iov_len = sizeof(req); 461 462 msg.msg_iov = &iov; 463 msg.msg_iovlen = 1; 464 465 len = recvmsg(c, &msg, 0); 466 if (len > 0) { 467 memcpy(&fd, CMSG_DATA(cmsg), sizeof(fd)); 468 return fd; 469 } 470 471 return len; 472 } 473 474 static int net_bridge_run_helper(const char *helper, const char *bridge, 475 Error **errp) 476 { 477 sigset_t oldmask, mask; 478 int pid, status; 479 char *args[5]; 480 char **parg; 481 int sv[2]; 482 483 sigemptyset(&mask); 484 sigaddset(&mask, SIGCHLD); 485 sigprocmask(SIG_BLOCK, &mask, &oldmask); 486 487 if (socketpair(PF_UNIX, SOCK_STREAM, 0, sv) == -1) { 488 error_setg_errno(errp, errno, "socketpair() failed"); 489 return -1; 490 } 491 492 /* try to launch bridge helper */ 493 pid = fork(); 494 if (pid < 0) { 495 error_setg_errno(errp, errno, "Can't fork bridge helper"); 496 return -1; 497 } 498 if (pid == 0) { 499 int open_max = sysconf(_SC_OPEN_MAX), i; 500 char fd_buf[6+10]; 501 char br_buf[6+IFNAMSIZ] = {0}; 502 char helper_cmd[PATH_MAX + sizeof(fd_buf) + sizeof(br_buf) + 15]; 503 504 for (i = 3; i < open_max; i++) { 505 if (i != sv[1]) { 506 close(i); 507 } 508 } 509 510 snprintf(fd_buf, sizeof(fd_buf), "%s%d", "--fd=", sv[1]); 511 512 if (strrchr(helper, ' ') || strrchr(helper, '\t')) { 513 /* assume helper is a command */ 514 515 if (strstr(helper, "--br=") == NULL) { 516 snprintf(br_buf, sizeof(br_buf), "%s%s", "--br=", bridge); 517 } 518 519 snprintf(helper_cmd, sizeof(helper_cmd), "%s %s %s %s", 520 helper, "--use-vnet", fd_buf, br_buf); 521 522 parg = args; 523 *parg++ = (char *)"sh"; 524 *parg++ = (char *)"-c"; 525 *parg++ = helper_cmd; 526 *parg++ = NULL; 527 528 execv("/bin/sh", args); 529 } else { 530 /* assume helper is just the executable path name */ 531 532 snprintf(br_buf, sizeof(br_buf), "%s%s", "--br=", bridge); 533 534 parg = args; 535 *parg++ = (char *)helper; 536 *parg++ = (char *)"--use-vnet"; 537 *parg++ = fd_buf; 538 *parg++ = br_buf; 539 *parg++ = NULL; 540 541 execv(helper, args); 542 } 543 _exit(1); 544 545 } else { 546 int fd; 547 int saved_errno; 548 549 close(sv[1]); 550 551 do { 552 fd = recv_fd(sv[0]); 553 } while (fd == -1 && errno == EINTR); 554 saved_errno = errno; 555 556 close(sv[0]); 557 558 while (waitpid(pid, &status, 0) != pid) { 559 /* loop */ 560 } 561 sigprocmask(SIG_SETMASK, &oldmask, NULL); 562 if (fd < 0) { 563 error_setg_errno(errp, saved_errno, 564 "failed to recv file descriptor"); 565 return -1; 566 } 567 if (!WIFEXITED(status) || WEXITSTATUS(status) != 0) { 568 error_setg(errp, "bridge helper failed"); 569 return -1; 570 } 571 return fd; 572 } 573 } 574 575 int net_init_bridge(const Netdev *netdev, const char *name, 576 NetClientState *peer, Error **errp) 577 { 578 const NetdevBridgeOptions *bridge; 579 const char *helper, *br; 580 TAPState *s; 581 int fd, vnet_hdr; 582 583 assert(netdev->type == NET_CLIENT_DRIVER_BRIDGE); 584 bridge = &netdev->u.bridge; 585 586 helper = bridge->has_helper ? bridge->helper : DEFAULT_BRIDGE_HELPER; 587 br = bridge->has_br ? bridge->br : DEFAULT_BRIDGE_INTERFACE; 588 589 fd = net_bridge_run_helper(helper, br, errp); 590 if (fd == -1) { 591 return -1; 592 } 593 594 fcntl(fd, F_SETFL, O_NONBLOCK); 595 vnet_hdr = tap_probe_vnet_hdr(fd); 596 s = net_tap_fd_init(peer, "bridge", name, fd, vnet_hdr); 597 598 snprintf(s->nc.info_str, sizeof(s->nc.info_str), "helper=%s,br=%s", helper, 599 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 TFR(fd = 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 return; 655 } 656 657 if (tap->has_fd || tap->has_fds) { 658 snprintf(s->nc.info_str, sizeof(s->nc.info_str), "fd=%d", fd); 659 } else if (tap->has_helper) { 660 snprintf(s->nc.info_str, sizeof(s->nc.info_str), "helper=%s", 661 tap->helper); 662 } else { 663 snprintf(s->nc.info_str, sizeof(s->nc.info_str), 664 "ifname=%s,script=%s,downscript=%s", ifname, script, 665 downscript); 666 667 if (strcmp(downscript, "no") != 0) { 668 snprintf(s->down_script, sizeof(s->down_script), "%s", downscript); 669 snprintf(s->down_script_arg, sizeof(s->down_script_arg), 670 "%s", ifname); 671 } 672 } 673 674 if (tap->has_vhost ? tap->vhost : 675 vhostfdname || (tap->has_vhostforce && tap->vhostforce)) { 676 VhostNetOptions options; 677 678 options.backend_type = VHOST_BACKEND_TYPE_KERNEL; 679 options.net_backend = &s->nc; 680 if (tap->has_poll_us) { 681 options.busyloop_timeout = tap->poll_us; 682 } else { 683 options.busyloop_timeout = 0; 684 } 685 686 if (vhostfdname) { 687 vhostfd = monitor_fd_param(cur_mon, vhostfdname, &err); 688 if (vhostfd == -1) { 689 error_propagate(errp, err); 690 return; 691 } 692 } else { 693 vhostfd = open("/dev/vhost-net", O_RDWR); 694 if (vhostfd < 0) { 695 error_setg_errno(errp, errno, 696 "tap: open vhost char device failed"); 697 return; 698 } 699 fcntl(vhostfd, F_SETFL, O_NONBLOCK); 700 } 701 options.opaque = (void *)(uintptr_t)vhostfd; 702 703 s->vhost_net = vhost_net_init(&options); 704 if (!s->vhost_net) { 705 error_setg(errp, 706 "vhost-net requested but could not be initialized"); 707 return; 708 } 709 } else if (vhostfdname) { 710 error_setg(errp, "vhostfd(s)= is not valid without vhost"); 711 } 712 } 713 714 static int get_fds(char *str, char *fds[], int max) 715 { 716 char *ptr = str, *this; 717 size_t len = strlen(str); 718 int i = 0; 719 720 while (i < max && ptr < str + len) { 721 this = strchr(ptr, ':'); 722 723 if (this == NULL) { 724 fds[i] = g_strdup(ptr); 725 } else { 726 fds[i] = g_strndup(ptr, this - ptr); 727 } 728 729 i++; 730 if (this == NULL) { 731 break; 732 } else { 733 ptr = this + 1; 734 } 735 } 736 737 return i; 738 } 739 740 int net_init_tap(const Netdev *netdev, const char *name, 741 NetClientState *peer, Error **errp) 742 { 743 const NetdevTapOptions *tap; 744 int fd, vnet_hdr = 0, i = 0, queues; 745 /* for the no-fd, no-helper case */ 746 const char *script = NULL; /* suppress wrong "uninit'd use" gcc warning */ 747 const char *downscript = NULL; 748 Error *err = NULL; 749 const char *vhostfdname; 750 char ifname[128]; 751 752 assert(netdev->type == NET_CLIENT_DRIVER_TAP); 753 tap = &netdev->u.tap; 754 queues = tap->has_queues ? tap->queues : 1; 755 vhostfdname = tap->has_vhostfd ? tap->vhostfd : NULL; 756 757 /* QEMU vlans does not support multiqueue tap, in this case peer is set. 758 * For -netdev, peer is always NULL. */ 759 if (peer && (tap->has_queues || tap->has_fds || tap->has_vhostfds)) { 760 error_setg(errp, "Multiqueue tap cannot be used with QEMU vlans"); 761 return -1; 762 } 763 764 if (tap->has_fd) { 765 if (tap->has_ifname || tap->has_script || tap->has_downscript || 766 tap->has_vnet_hdr || tap->has_helper || tap->has_queues || 767 tap->has_fds || tap->has_vhostfds) { 768 error_setg(errp, "ifname=, script=, downscript=, vnet_hdr=, " 769 "helper=, queues=, fds=, and vhostfds= " 770 "are invalid with fd="); 771 return -1; 772 } 773 774 fd = monitor_fd_param(cur_mon, tap->fd, &err); 775 if (fd == -1) { 776 error_propagate(errp, err); 777 return -1; 778 } 779 780 fcntl(fd, F_SETFL, O_NONBLOCK); 781 782 vnet_hdr = tap_probe_vnet_hdr(fd); 783 784 net_init_tap_one(tap, peer, "tap", name, NULL, 785 script, downscript, 786 vhostfdname, vnet_hdr, fd, &err); 787 if (err) { 788 error_propagate(errp, err); 789 return -1; 790 } 791 } else if (tap->has_fds) { 792 char **fds; 793 char **vhost_fds; 794 int nfds, nvhosts; 795 796 if (tap->has_ifname || tap->has_script || tap->has_downscript || 797 tap->has_vnet_hdr || tap->has_helper || tap->has_queues || 798 tap->has_vhostfd) { 799 error_setg(errp, "ifname=, script=, downscript=, vnet_hdr=, " 800 "helper=, queues=, and vhostfd= " 801 "are invalid with fds="); 802 return -1; 803 } 804 805 fds = g_new0(char *, MAX_TAP_QUEUES); 806 vhost_fds = g_new0(char *, MAX_TAP_QUEUES); 807 808 nfds = get_fds(tap->fds, fds, MAX_TAP_QUEUES); 809 if (tap->has_vhostfds) { 810 nvhosts = get_fds(tap->vhostfds, vhost_fds, MAX_TAP_QUEUES); 811 if (nfds != nvhosts) { 812 error_setg(errp, "The number of fds passed does not match " 813 "the number of vhostfds passed"); 814 goto free_fail; 815 } 816 } 817 818 for (i = 0; i < nfds; i++) { 819 fd = monitor_fd_param(cur_mon, fds[i], &err); 820 if (fd == -1) { 821 error_propagate(errp, err); 822 goto free_fail; 823 } 824 825 fcntl(fd, F_SETFL, O_NONBLOCK); 826 827 if (i == 0) { 828 vnet_hdr = tap_probe_vnet_hdr(fd); 829 } else if (vnet_hdr != tap_probe_vnet_hdr(fd)) { 830 error_setg(errp, 831 "vnet_hdr not consistent across given tap fds"); 832 goto free_fail; 833 } 834 835 net_init_tap_one(tap, peer, "tap", name, ifname, 836 script, downscript, 837 tap->has_vhostfds ? vhost_fds[i] : NULL, 838 vnet_hdr, fd, &err); 839 if (err) { 840 error_propagate(errp, err); 841 goto free_fail; 842 } 843 } 844 g_free(fds); 845 g_free(vhost_fds); 846 return 0; 847 848 free_fail: 849 for (i = 0; i < nfds; i++) { 850 g_free(fds[i]); 851 g_free(vhost_fds[i]); 852 } 853 g_free(fds); 854 g_free(vhost_fds); 855 return -1; 856 } else if (tap->has_helper) { 857 if (tap->has_ifname || tap->has_script || tap->has_downscript || 858 tap->has_vnet_hdr || tap->has_queues || tap->has_vhostfds) { 859 error_setg(errp, "ifname=, script=, downscript=, vnet_hdr=, " 860 "queues=, and vhostfds= are invalid with helper="); 861 return -1; 862 } 863 864 fd = net_bridge_run_helper(tap->helper, 865 tap->has_br ? 866 tap->br : DEFAULT_BRIDGE_INTERFACE, 867 errp); 868 if (fd == -1) { 869 return -1; 870 } 871 872 fcntl(fd, F_SETFL, O_NONBLOCK); 873 vnet_hdr = tap_probe_vnet_hdr(fd); 874 875 net_init_tap_one(tap, peer, "bridge", name, ifname, 876 script, downscript, vhostfdname, 877 vnet_hdr, fd, &err); 878 if (err) { 879 error_propagate(errp, err); 880 close(fd); 881 return -1; 882 } 883 } else { 884 if (tap->has_vhostfds) { 885 error_setg(errp, "vhostfds= is invalid if fds= wasn't specified"); 886 return -1; 887 } 888 script = tap->has_script ? tap->script : DEFAULT_NETWORK_SCRIPT; 889 downscript = tap->has_downscript ? tap->downscript : 890 DEFAULT_NETWORK_DOWN_SCRIPT; 891 892 if (tap->has_ifname) { 893 pstrcpy(ifname, sizeof ifname, tap->ifname); 894 } else { 895 ifname[0] = '\0'; 896 } 897 898 for (i = 0; i < queues; i++) { 899 fd = net_tap_init(tap, &vnet_hdr, i >= 1 ? "no" : script, 900 ifname, sizeof ifname, queues > 1, errp); 901 if (fd == -1) { 902 return -1; 903 } 904 905 if (queues > 1 && i == 0 && !tap->has_ifname) { 906 if (tap_fd_get_ifname(fd, ifname)) { 907 error_setg(errp, "Fail to get ifname"); 908 close(fd); 909 return -1; 910 } 911 } 912 913 net_init_tap_one(tap, peer, "tap", name, ifname, 914 i >= 1 ? "no" : script, 915 i >= 1 ? "no" : downscript, 916 vhostfdname, vnet_hdr, fd, &err); 917 if (err) { 918 error_propagate(errp, err); 919 close(fd); 920 return -1; 921 } 922 } 923 } 924 925 return 0; 926 } 927 928 VHostNetState *tap_get_vhost_net(NetClientState *nc) 929 { 930 TAPState *s = DO_UPCAST(TAPState, nc, nc); 931 assert(nc->info->type == NET_CLIENT_DRIVER_TAP); 932 return s->vhost_net; 933 } 934 935 int tap_enable(NetClientState *nc) 936 { 937 TAPState *s = DO_UPCAST(TAPState, nc, nc); 938 int ret; 939 940 if (s->enabled) { 941 return 0; 942 } else { 943 ret = tap_fd_enable(s->fd); 944 if (ret == 0) { 945 s->enabled = true; 946 tap_update_fd_handler(s); 947 } 948 return ret; 949 } 950 } 951 952 int tap_disable(NetClientState *nc) 953 { 954 TAPState *s = DO_UPCAST(TAPState, nc, nc); 955 int ret; 956 957 if (s->enabled == 0) { 958 return 0; 959 } else { 960 ret = tap_fd_disable(s->fd); 961 if (ret == 0) { 962 qemu_purge_queued_packets(nc); 963 s->enabled = false; 964 tap_update_fd_handler(s); 965 } 966 return ret; 967 } 968 } 969