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 close_all_fds_after_fork(int excluded_fd) 389 { 390 const int skip_fd[] = {STDIN_FILENO, STDOUT_FILENO, STDERR_FILENO, 391 excluded_fd}; 392 unsigned int nskip = ARRAY_SIZE(skip_fd); 393 394 /* 395 * skip_fd must be an ordered array of distinct fds, exclude 396 * excluded_fd if already included in the [STDIN_FILENO - STDERR_FILENO] 397 * range 398 */ 399 if (excluded_fd <= STDERR_FILENO) { 400 nskip--; 401 } 402 403 qemu_close_all_open_fd(skip_fd, nskip); 404 } 405 406 static void launch_script(const char *setup_script, const char *ifname, 407 int fd, Error **errp) 408 { 409 int pid, status; 410 char *args[3]; 411 char **parg; 412 413 /* try to launch network script */ 414 pid = fork(); 415 if (pid < 0) { 416 error_setg_errno(errp, errno, "could not launch network script %s", 417 setup_script); 418 return; 419 } 420 if (pid == 0) { 421 close_all_fds_after_fork(fd); 422 parg = args; 423 *parg++ = (char *)setup_script; 424 *parg++ = (char *)ifname; 425 *parg = NULL; 426 execv(setup_script, args); 427 _exit(1); 428 } else { 429 while (waitpid(pid, &status, 0) != pid) { 430 /* loop */ 431 } 432 433 if (WIFEXITED(status) && WEXITSTATUS(status) == 0) { 434 return; 435 } 436 error_setg(errp, "network script %s failed with status %d", 437 setup_script, status); 438 } 439 } 440 441 static int recv_fd(int c) 442 { 443 int fd; 444 uint8_t msgbuf[CMSG_SPACE(sizeof(fd))]; 445 struct msghdr msg = { 446 .msg_control = msgbuf, 447 .msg_controllen = sizeof(msgbuf), 448 }; 449 struct cmsghdr *cmsg; 450 struct iovec iov; 451 uint8_t req[1]; 452 ssize_t len; 453 454 cmsg = CMSG_FIRSTHDR(&msg); 455 cmsg->cmsg_level = SOL_SOCKET; 456 cmsg->cmsg_type = SCM_RIGHTS; 457 cmsg->cmsg_len = CMSG_LEN(sizeof(fd)); 458 msg.msg_controllen = cmsg->cmsg_len; 459 460 iov.iov_base = req; 461 iov.iov_len = sizeof(req); 462 463 msg.msg_iov = &iov; 464 msg.msg_iovlen = 1; 465 466 len = recvmsg(c, &msg, 0); 467 if (len > 0) { 468 memcpy(&fd, CMSG_DATA(cmsg), sizeof(fd)); 469 return fd; 470 } 471 472 return len; 473 } 474 475 static int net_bridge_run_helper(const char *helper, const char *bridge, 476 Error **errp) 477 { 478 sigset_t oldmask, mask; 479 g_autofree char *default_helper = NULL; 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 (!helper) { 490 helper = default_helper = get_relocated_path(DEFAULT_BRIDGE_HELPER); 491 } 492 493 if (socketpair(PF_UNIX, SOCK_STREAM, 0, sv) == -1) { 494 error_setg_errno(errp, errno, "socketpair() failed"); 495 return -1; 496 } 497 498 /* try to launch bridge helper */ 499 pid = fork(); 500 if (pid < 0) { 501 error_setg_errno(errp, errno, "Can't fork bridge helper"); 502 return -1; 503 } 504 if (pid == 0) { 505 char *fd_buf = NULL; 506 char *br_buf = NULL; 507 char *helper_cmd = NULL; 508 509 close_all_fds_after_fork(sv[1]); 510 fd_buf = g_strdup_printf("%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 br_buf = g_strdup_printf("%s%s", "--br=", bridge); 517 } 518 519 helper_cmd = g_strdup_printf("%s %s %s %s", helper, 520 "--use-vnet", fd_buf, br_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 g_free(helper_cmd); 530 } else { 531 /* assume helper is just the executable path name */ 532 533 br_buf = g_strdup_printf("%s%s", "--br=", bridge); 534 535 parg = args; 536 *parg++ = (char *)helper; 537 *parg++ = (char *)"--use-vnet"; 538 *parg++ = fd_buf; 539 *parg++ = br_buf; 540 *parg++ = NULL; 541 542 execv(helper, args); 543 } 544 g_free(fd_buf); 545 g_free(br_buf); 546 _exit(1); 547 548 } else { 549 int fd; 550 int saved_errno; 551 552 close(sv[1]); 553 554 fd = RETRY_ON_EINTR(recv_fd(sv[0])); 555 saved_errno = errno; 556 557 close(sv[0]); 558 559 while (waitpid(pid, &status, 0) != pid) { 560 /* loop */ 561 } 562 sigprocmask(SIG_SETMASK, &oldmask, NULL); 563 if (fd < 0) { 564 error_setg_errno(errp, saved_errno, 565 "failed to recv file descriptor"); 566 return -1; 567 } 568 if (!WIFEXITED(status) || WEXITSTATUS(status) != 0) { 569 error_setg(errp, "bridge helper failed"); 570 return -1; 571 } 572 return fd; 573 } 574 } 575 576 int net_init_bridge(const Netdev *netdev, const char *name, 577 NetClientState *peer, Error **errp) 578 { 579 const NetdevBridgeOptions *bridge; 580 const char *helper, *br; 581 TAPState *s; 582 int fd, vnet_hdr; 583 584 assert(netdev->type == NET_CLIENT_DRIVER_BRIDGE); 585 bridge = &netdev->u.bridge; 586 helper = bridge->helper; 587 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 if (!g_unix_set_fd_nonblocking(fd, true, NULL)) { 595 error_setg_errno(errp, errno, "Failed to set FD nonblocking"); 596 return -1; 597 } 598 vnet_hdr = tap_probe_vnet_hdr(fd, errp); 599 if (vnet_hdr < 0) { 600 close(fd); 601 return -1; 602 } 603 s = net_tap_fd_init(peer, "bridge", name, fd, vnet_hdr); 604 605 qemu_set_info_str(&s->nc, "helper=%s,br=%s", helper, br); 606 607 return 0; 608 } 609 610 static int net_tap_init(const NetdevTapOptions *tap, int *vnet_hdr, 611 const char *setup_script, char *ifname, 612 size_t ifname_sz, int mq_required, Error **errp) 613 { 614 Error *err = NULL; 615 int fd, vnet_hdr_required; 616 617 if (tap->has_vnet_hdr) { 618 *vnet_hdr = tap->vnet_hdr; 619 vnet_hdr_required = *vnet_hdr; 620 } else { 621 *vnet_hdr = 1; 622 vnet_hdr_required = 0; 623 } 624 625 fd = RETRY_ON_EINTR(tap_open(ifname, ifname_sz, vnet_hdr, vnet_hdr_required, 626 mq_required, errp)); 627 if (fd < 0) { 628 return -1; 629 } 630 631 if (setup_script && 632 setup_script[0] != '\0' && 633 strcmp(setup_script, "no") != 0) { 634 launch_script(setup_script, ifname, fd, &err); 635 if (err) { 636 error_propagate(errp, err); 637 close(fd); 638 return -1; 639 } 640 } 641 642 return fd; 643 } 644 645 #define MAX_TAP_QUEUES 1024 646 647 static void net_init_tap_one(const NetdevTapOptions *tap, NetClientState *peer, 648 const char *model, const char *name, 649 const char *ifname, const char *script, 650 const char *downscript, const char *vhostfdname, 651 int vnet_hdr, int fd, Error **errp) 652 { 653 Error *err = NULL; 654 TAPState *s = net_tap_fd_init(peer, model, name, fd, vnet_hdr); 655 int vhostfd; 656 657 tap_set_sndbuf(s->fd, tap, &err); 658 if (err) { 659 error_propagate(errp, err); 660 goto failed; 661 } 662 663 if (tap->fd || tap->fds) { 664 qemu_set_info_str(&s->nc, "fd=%d", fd); 665 } else if (tap->helper) { 666 qemu_set_info_str(&s->nc, "helper=%s", tap->helper); 667 } else { 668 qemu_set_info_str(&s->nc, "ifname=%s,script=%s,downscript=%s", ifname, 669 script, downscript); 670 671 if (strcmp(downscript, "no") != 0) { 672 snprintf(s->down_script, sizeof(s->down_script), "%s", downscript); 673 snprintf(s->down_script_arg, sizeof(s->down_script_arg), 674 "%s", ifname); 675 } 676 } 677 678 if (tap->has_vhost ? tap->vhost : 679 vhostfdname || (tap->has_vhostforce && tap->vhostforce)) { 680 VhostNetOptions options; 681 682 options.backend_type = VHOST_BACKEND_TYPE_KERNEL; 683 options.net_backend = &s->nc; 684 if (tap->has_poll_us) { 685 options.busyloop_timeout = tap->poll_us; 686 } else { 687 options.busyloop_timeout = 0; 688 } 689 690 if (vhostfdname) { 691 vhostfd = monitor_fd_param(monitor_cur(), vhostfdname, &err); 692 if (vhostfd == -1) { 693 error_propagate(errp, err); 694 goto failed; 695 } 696 if (!g_unix_set_fd_nonblocking(vhostfd, true, NULL)) { 697 error_setg_errno(errp, errno, "%s: Can't use file descriptor %d", 698 name, fd); 699 goto failed; 700 } 701 } else { 702 vhostfd = open("/dev/vhost-net", O_RDWR); 703 if (vhostfd < 0) { 704 error_setg_errno(errp, errno, 705 "tap: open vhost char device failed"); 706 goto failed; 707 } 708 if (!g_unix_set_fd_nonblocking(vhostfd, true, NULL)) { 709 error_setg_errno(errp, errno, "Failed to set FD nonblocking"); 710 goto failed; 711 } 712 } 713 options.opaque = (void *)(uintptr_t)vhostfd; 714 options.nvqs = 2; 715 716 s->vhost_net = vhost_net_init(&options); 717 if (!s->vhost_net) { 718 error_setg(errp, 719 "vhost-net requested but could not be initialized"); 720 goto failed; 721 } 722 } else if (vhostfdname) { 723 error_setg(errp, "vhostfd(s)= is not valid without vhost"); 724 goto failed; 725 } 726 727 return; 728 729 failed: 730 qemu_del_net_client(&s->nc); 731 } 732 733 static int get_fds(char *str, char *fds[], int max) 734 { 735 char *ptr = str, *this; 736 size_t len = strlen(str); 737 int i = 0; 738 739 while (i < max && ptr < str + len) { 740 this = strchr(ptr, ':'); 741 742 if (this == NULL) { 743 fds[i] = g_strdup(ptr); 744 } else { 745 fds[i] = g_strndup(ptr, this - ptr); 746 } 747 748 i++; 749 if (this == NULL) { 750 break; 751 } else { 752 ptr = this + 1; 753 } 754 } 755 756 return i; 757 } 758 759 int net_init_tap(const Netdev *netdev, const char *name, 760 NetClientState *peer, Error **errp) 761 { 762 const NetdevTapOptions *tap; 763 int fd, vnet_hdr = 0, i = 0, queues; 764 /* for the no-fd, no-helper case */ 765 const char *script; 766 const char *downscript; 767 Error *err = NULL; 768 const char *vhostfdname; 769 char ifname[128]; 770 int ret = 0; 771 772 assert(netdev->type == NET_CLIENT_DRIVER_TAP); 773 tap = &netdev->u.tap; 774 queues = tap->has_queues ? tap->queues : 1; 775 vhostfdname = tap->vhostfd; 776 script = tap->script; 777 downscript = tap->downscript; 778 779 /* QEMU hubs do not support multiqueue tap, in this case peer is set. 780 * For -netdev, peer is always NULL. */ 781 if (peer && (tap->has_queues || tap->fds || tap->vhostfds)) { 782 error_setg(errp, "Multiqueue tap cannot be used with hubs"); 783 return -1; 784 } 785 786 if (tap->fd) { 787 if (tap->ifname || tap->script || tap->downscript || 788 tap->has_vnet_hdr || tap->helper || tap->has_queues || 789 tap->fds || tap->vhostfds) { 790 error_setg(errp, "ifname=, script=, downscript=, vnet_hdr=, " 791 "helper=, queues=, fds=, and vhostfds= " 792 "are invalid with fd="); 793 return -1; 794 } 795 796 fd = monitor_fd_param(monitor_cur(), tap->fd, errp); 797 if (fd == -1) { 798 return -1; 799 } 800 801 if (!g_unix_set_fd_nonblocking(fd, true, NULL)) { 802 error_setg_errno(errp, errno, "%s: Can't use file descriptor %d", 803 name, fd); 804 close(fd); 805 return -1; 806 } 807 808 vnet_hdr = tap_probe_vnet_hdr(fd, errp); 809 if (vnet_hdr < 0) { 810 close(fd); 811 return -1; 812 } 813 814 net_init_tap_one(tap, peer, "tap", name, NULL, 815 script, downscript, 816 vhostfdname, vnet_hdr, fd, &err); 817 if (err) { 818 error_propagate(errp, err); 819 close(fd); 820 return -1; 821 } 822 } else if (tap->fds) { 823 char **fds; 824 char **vhost_fds; 825 int nfds = 0, nvhosts = 0; 826 827 if (tap->ifname || tap->script || tap->downscript || 828 tap->has_vnet_hdr || tap->helper || tap->has_queues || 829 tap->vhostfd) { 830 error_setg(errp, "ifname=, script=, downscript=, vnet_hdr=, " 831 "helper=, queues=, and vhostfd= " 832 "are invalid with fds="); 833 return -1; 834 } 835 836 fds = g_new0(char *, MAX_TAP_QUEUES); 837 vhost_fds = g_new0(char *, MAX_TAP_QUEUES); 838 839 nfds = get_fds(tap->fds, fds, MAX_TAP_QUEUES); 840 if (tap->vhostfds) { 841 nvhosts = get_fds(tap->vhostfds, vhost_fds, MAX_TAP_QUEUES); 842 if (nfds != nvhosts) { 843 error_setg(errp, "The number of fds passed does not match " 844 "the number of vhostfds passed"); 845 ret = -1; 846 goto free_fail; 847 } 848 } 849 850 for (i = 0; i < nfds; i++) { 851 fd = monitor_fd_param(monitor_cur(), fds[i], errp); 852 if (fd == -1) { 853 ret = -1; 854 goto free_fail; 855 } 856 857 ret = g_unix_set_fd_nonblocking(fd, true, NULL); 858 if (!ret) { 859 error_setg_errno(errp, errno, "%s: Can't use file descriptor %d", 860 name, fd); 861 goto free_fail; 862 } 863 864 if (i == 0) { 865 vnet_hdr = tap_probe_vnet_hdr(fd, errp); 866 if (vnet_hdr < 0) { 867 ret = -1; 868 goto free_fail; 869 } 870 } else if (vnet_hdr != tap_probe_vnet_hdr(fd, NULL)) { 871 error_setg(errp, 872 "vnet_hdr not consistent across given tap fds"); 873 ret = -1; 874 goto free_fail; 875 } 876 877 net_init_tap_one(tap, peer, "tap", name, ifname, 878 script, downscript, 879 tap->vhostfds ? vhost_fds[i] : NULL, 880 vnet_hdr, fd, &err); 881 if (err) { 882 error_propagate(errp, err); 883 ret = -1; 884 goto free_fail; 885 } 886 } 887 888 free_fail: 889 for (i = 0; i < nvhosts; i++) { 890 g_free(vhost_fds[i]); 891 } 892 for (i = 0; i < nfds; i++) { 893 g_free(fds[i]); 894 } 895 g_free(fds); 896 g_free(vhost_fds); 897 return ret; 898 } else if (tap->helper) { 899 if (tap->ifname || tap->script || tap->downscript || 900 tap->has_vnet_hdr || tap->has_queues || tap->vhostfds) { 901 error_setg(errp, "ifname=, script=, downscript=, vnet_hdr=, " 902 "queues=, and vhostfds= are invalid with helper="); 903 return -1; 904 } 905 906 fd = net_bridge_run_helper(tap->helper, 907 tap->br ?: DEFAULT_BRIDGE_INTERFACE, 908 errp); 909 if (fd == -1) { 910 return -1; 911 } 912 913 if (!g_unix_set_fd_nonblocking(fd, true, NULL)) { 914 error_setg_errno(errp, errno, "Failed to set FD nonblocking"); 915 return -1; 916 } 917 vnet_hdr = tap_probe_vnet_hdr(fd, errp); 918 if (vnet_hdr < 0) { 919 close(fd); 920 return -1; 921 } 922 923 net_init_tap_one(tap, peer, "bridge", name, ifname, 924 script, downscript, vhostfdname, 925 vnet_hdr, fd, &err); 926 if (err) { 927 error_propagate(errp, err); 928 close(fd); 929 return -1; 930 } 931 } else { 932 g_autofree char *default_script = NULL; 933 g_autofree char *default_downscript = NULL; 934 if (tap->vhostfds) { 935 error_setg(errp, "vhostfds= is invalid if fds= wasn't specified"); 936 return -1; 937 } 938 939 if (!script) { 940 script = default_script = get_relocated_path(DEFAULT_NETWORK_SCRIPT); 941 } 942 if (!downscript) { 943 downscript = default_downscript = 944 get_relocated_path(DEFAULT_NETWORK_DOWN_SCRIPT); 945 } 946 947 if (tap->ifname) { 948 pstrcpy(ifname, sizeof ifname, tap->ifname); 949 } else { 950 ifname[0] = '\0'; 951 } 952 953 for (i = 0; i < queues; i++) { 954 fd = net_tap_init(tap, &vnet_hdr, i >= 1 ? "no" : script, 955 ifname, sizeof ifname, queues > 1, errp); 956 if (fd == -1) { 957 return -1; 958 } 959 960 if (queues > 1 && i == 0 && !tap->ifname) { 961 if (tap_fd_get_ifname(fd, ifname)) { 962 error_setg(errp, "Fail to get ifname"); 963 close(fd); 964 return -1; 965 } 966 } 967 968 net_init_tap_one(tap, peer, "tap", name, ifname, 969 i >= 1 ? "no" : script, 970 i >= 1 ? "no" : downscript, 971 vhostfdname, vnet_hdr, fd, &err); 972 if (err) { 973 error_propagate(errp, err); 974 close(fd); 975 return -1; 976 } 977 } 978 } 979 980 return 0; 981 } 982 983 VHostNetState *tap_get_vhost_net(NetClientState *nc) 984 { 985 TAPState *s = DO_UPCAST(TAPState, nc, nc); 986 assert(nc->info->type == NET_CLIENT_DRIVER_TAP); 987 return s->vhost_net; 988 } 989 990 int tap_enable(NetClientState *nc) 991 { 992 TAPState *s = DO_UPCAST(TAPState, nc, nc); 993 int ret; 994 995 if (s->enabled) { 996 return 0; 997 } else { 998 ret = tap_fd_enable(s->fd); 999 if (ret == 0) { 1000 s->enabled = true; 1001 tap_update_fd_handler(s); 1002 } 1003 return ret; 1004 } 1005 } 1006 1007 int tap_disable(NetClientState *nc) 1008 { 1009 TAPState *s = DO_UPCAST(TAPState, nc, nc); 1010 int ret; 1011 1012 if (s->enabled == 0) { 1013 return 0; 1014 } else { 1015 ret = tap_fd_disable(s->fd); 1016 if (ret == 0) { 1017 qemu_purge_queued_packets(nc); 1018 s->enabled = false; 1019 tap_update_fd_handler(s); 1020 } 1021 return ret; 1022 } 1023 } 1024