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_mrg_rxbuf 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_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 uint8_t min_pkt[ETH_ZLEN]; 193 size_t min_pktsz = sizeof(min_pkt); 194 195 size = tap_read_packet(s->fd, s->buf, sizeof(s->buf)); 196 if (size <= 0) { 197 break; 198 } 199 200 if (s->host_vnet_hdr_len && !s->using_vnet_hdr) { 201 buf += s->host_vnet_hdr_len; 202 size -= s->host_vnet_hdr_len; 203 } 204 205 if (net_peer_needs_padding(&s->nc)) { 206 if (eth_pad_short_frame(min_pkt, &min_pktsz, buf, size)) { 207 buf = min_pkt; 208 size = min_pktsz; 209 } 210 } 211 212 size = qemu_send_packet_async(&s->nc, buf, size, tap_send_completed); 213 if (size == 0) { 214 tap_read_poll(s, false); 215 break; 216 } else if (size < 0) { 217 break; 218 } 219 220 /* 221 * When the host keeps receiving more packets while tap_send() is 222 * running we can hog the BQL. Limit the number of 223 * packets that are processed per tap_send() callback to prevent 224 * stalling the guest. 225 */ 226 packets++; 227 if (packets >= 50) { 228 break; 229 } 230 } 231 } 232 233 static bool tap_has_ufo(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->has_ufo; 240 } 241 242 static bool tap_has_uso(NetClientState *nc) 243 { 244 TAPState *s = DO_UPCAST(TAPState, nc, nc); 245 246 assert(nc->info->type == NET_CLIENT_DRIVER_TAP); 247 248 return s->has_uso; 249 } 250 251 static bool tap_has_vnet_hdr(NetClientState *nc) 252 { 253 TAPState *s = DO_UPCAST(TAPState, nc, nc); 254 255 assert(nc->info->type == NET_CLIENT_DRIVER_TAP); 256 257 return !!s->host_vnet_hdr_len; 258 } 259 260 static bool tap_has_vnet_hdr_len(NetClientState *nc, int len) 261 { 262 return tap_has_vnet_hdr(nc); 263 } 264 265 static int tap_get_vnet_hdr_len(NetClientState *nc) 266 { 267 TAPState *s = DO_UPCAST(TAPState, nc, nc); 268 269 return s->host_vnet_hdr_len; 270 } 271 272 static void tap_set_vnet_hdr_len(NetClientState *nc, int len) 273 { 274 TAPState *s = DO_UPCAST(TAPState, nc, nc); 275 276 assert(nc->info->type == NET_CLIENT_DRIVER_TAP); 277 assert(len == sizeof(struct virtio_net_hdr_mrg_rxbuf) || 278 len == sizeof(struct virtio_net_hdr) || 279 len == sizeof(struct virtio_net_hdr_v1_hash)); 280 281 tap_fd_set_vnet_hdr_len(s->fd, len); 282 s->host_vnet_hdr_len = len; 283 } 284 285 static bool tap_get_using_vnet_hdr(NetClientState *nc) 286 { 287 TAPState *s = DO_UPCAST(TAPState, nc, nc); 288 289 return s->using_vnet_hdr; 290 } 291 292 static void tap_using_vnet_hdr(NetClientState *nc, bool using_vnet_hdr) 293 { 294 TAPState *s = DO_UPCAST(TAPState, nc, nc); 295 296 assert(nc->info->type == NET_CLIENT_DRIVER_TAP); 297 assert(!!s->host_vnet_hdr_len == using_vnet_hdr); 298 299 s->using_vnet_hdr = using_vnet_hdr; 300 } 301 302 static int tap_set_vnet_le(NetClientState *nc, bool is_le) 303 { 304 TAPState *s = DO_UPCAST(TAPState, nc, nc); 305 306 return tap_fd_set_vnet_le(s->fd, is_le); 307 } 308 309 static int tap_set_vnet_be(NetClientState *nc, bool is_be) 310 { 311 TAPState *s = DO_UPCAST(TAPState, nc, nc); 312 313 return tap_fd_set_vnet_be(s->fd, is_be); 314 } 315 316 static void tap_set_offload(NetClientState *nc, int csum, int tso4, 317 int tso6, int ecn, int ufo, int uso4, int uso6) 318 { 319 TAPState *s = DO_UPCAST(TAPState, nc, nc); 320 if (s->fd < 0) { 321 return; 322 } 323 324 tap_fd_set_offload(s->fd, csum, tso4, tso6, ecn, ufo, uso4, uso6); 325 } 326 327 static void tap_exit_notify(Notifier *notifier, void *data) 328 { 329 TAPState *s = container_of(notifier, TAPState, exit); 330 Error *err = NULL; 331 332 if (s->down_script[0]) { 333 launch_script(s->down_script, s->down_script_arg, s->fd, &err); 334 if (err) { 335 error_report_err(err); 336 } 337 } 338 } 339 340 static void tap_cleanup(NetClientState *nc) 341 { 342 TAPState *s = DO_UPCAST(TAPState, nc, nc); 343 344 if (s->vhost_net) { 345 vhost_net_cleanup(s->vhost_net); 346 g_free(s->vhost_net); 347 s->vhost_net = NULL; 348 } 349 350 qemu_purge_queued_packets(nc); 351 352 tap_exit_notify(&s->exit, NULL); 353 qemu_remove_exit_notifier(&s->exit); 354 355 tap_read_poll(s, false); 356 tap_write_poll(s, false); 357 close(s->fd); 358 s->fd = -1; 359 } 360 361 static void tap_poll(NetClientState *nc, bool enable) 362 { 363 TAPState *s = DO_UPCAST(TAPState, nc, nc); 364 tap_read_poll(s, enable); 365 tap_write_poll(s, enable); 366 } 367 368 static bool tap_set_steering_ebpf(NetClientState *nc, int prog_fd) 369 { 370 TAPState *s = DO_UPCAST(TAPState, nc, nc); 371 assert(nc->info->type == NET_CLIENT_DRIVER_TAP); 372 373 return tap_fd_set_steering_ebpf(s->fd, prog_fd) == 0; 374 } 375 376 int tap_get_fd(NetClientState *nc) 377 { 378 TAPState *s = DO_UPCAST(TAPState, nc, nc); 379 assert(nc->info->type == NET_CLIENT_DRIVER_TAP); 380 return s->fd; 381 } 382 383 /* fd support */ 384 385 static NetClientInfo net_tap_info = { 386 .type = NET_CLIENT_DRIVER_TAP, 387 .size = sizeof(TAPState), 388 .receive = tap_receive, 389 .receive_raw = tap_receive_raw, 390 .receive_iov = tap_receive_iov, 391 .poll = tap_poll, 392 .cleanup = tap_cleanup, 393 .has_ufo = tap_has_ufo, 394 .has_uso = tap_has_uso, 395 .has_vnet_hdr = tap_has_vnet_hdr, 396 .has_vnet_hdr_len = tap_has_vnet_hdr_len, 397 .get_using_vnet_hdr = tap_get_using_vnet_hdr, 398 .using_vnet_hdr = tap_using_vnet_hdr, 399 .set_offload = tap_set_offload, 400 .get_vnet_hdr_len = tap_get_vnet_hdr_len, 401 .set_vnet_hdr_len = tap_set_vnet_hdr_len, 402 .set_vnet_le = tap_set_vnet_le, 403 .set_vnet_be = tap_set_vnet_be, 404 .set_steering_ebpf = tap_set_steering_ebpf, 405 }; 406 407 static TAPState *net_tap_fd_init(NetClientState *peer, 408 const char *model, 409 const char *name, 410 int fd, 411 int vnet_hdr) 412 { 413 NetClientState *nc; 414 TAPState *s; 415 416 nc = qemu_new_net_client(&net_tap_info, peer, model, name); 417 418 s = DO_UPCAST(TAPState, nc, nc); 419 420 s->fd = fd; 421 s->host_vnet_hdr_len = vnet_hdr ? sizeof(struct virtio_net_hdr) : 0; 422 s->using_vnet_hdr = false; 423 s->has_ufo = tap_probe_has_ufo(s->fd); 424 s->has_uso = tap_probe_has_uso(s->fd); 425 s->enabled = true; 426 tap_set_offload(&s->nc, 0, 0, 0, 0, 0, 0, 0); 427 /* 428 * Make sure host header length is set correctly in tap: 429 * it might have been modified by another instance of qemu. 430 */ 431 if (vnet_hdr) { 432 tap_fd_set_vnet_hdr_len(s->fd, s->host_vnet_hdr_len); 433 } 434 tap_read_poll(s, true); 435 s->vhost_net = NULL; 436 437 s->exit.notify = tap_exit_notify; 438 qemu_add_exit_notifier(&s->exit); 439 440 return s; 441 } 442 443 static void launch_script(const char *setup_script, const char *ifname, 444 int fd, Error **errp) 445 { 446 int pid, status; 447 char *args[3]; 448 char **parg; 449 450 /* try to launch network script */ 451 pid = fork(); 452 if (pid < 0) { 453 error_setg_errno(errp, errno, "could not launch network script %s", 454 setup_script); 455 return; 456 } 457 if (pid == 0) { 458 int open_max = sysconf(_SC_OPEN_MAX), i; 459 460 for (i = 3; i < open_max; i++) { 461 if (i != fd) { 462 close(i); 463 } 464 } 465 parg = args; 466 *parg++ = (char *)setup_script; 467 *parg++ = (char *)ifname; 468 *parg = NULL; 469 execv(setup_script, args); 470 _exit(1); 471 } else { 472 while (waitpid(pid, &status, 0) != pid) { 473 /* loop */ 474 } 475 476 if (WIFEXITED(status) && WEXITSTATUS(status) == 0) { 477 return; 478 } 479 error_setg(errp, "network script %s failed with status %d", 480 setup_script, status); 481 } 482 } 483 484 static int recv_fd(int c) 485 { 486 int fd; 487 uint8_t msgbuf[CMSG_SPACE(sizeof(fd))]; 488 struct msghdr msg = { 489 .msg_control = msgbuf, 490 .msg_controllen = sizeof(msgbuf), 491 }; 492 struct cmsghdr *cmsg; 493 struct iovec iov; 494 uint8_t req[1]; 495 ssize_t len; 496 497 cmsg = CMSG_FIRSTHDR(&msg); 498 cmsg->cmsg_level = SOL_SOCKET; 499 cmsg->cmsg_type = SCM_RIGHTS; 500 cmsg->cmsg_len = CMSG_LEN(sizeof(fd)); 501 msg.msg_controllen = cmsg->cmsg_len; 502 503 iov.iov_base = req; 504 iov.iov_len = sizeof(req); 505 506 msg.msg_iov = &iov; 507 msg.msg_iovlen = 1; 508 509 len = recvmsg(c, &msg, 0); 510 if (len > 0) { 511 memcpy(&fd, CMSG_DATA(cmsg), sizeof(fd)); 512 return fd; 513 } 514 515 return len; 516 } 517 518 static int net_bridge_run_helper(const char *helper, const char *bridge, 519 Error **errp) 520 { 521 sigset_t oldmask, mask; 522 g_autofree char *default_helper = NULL; 523 int pid, status; 524 char *args[5]; 525 char **parg; 526 int sv[2]; 527 528 sigemptyset(&mask); 529 sigaddset(&mask, SIGCHLD); 530 sigprocmask(SIG_BLOCK, &mask, &oldmask); 531 532 if (!helper) { 533 helper = default_helper = get_relocated_path(DEFAULT_BRIDGE_HELPER); 534 } 535 536 if (socketpair(PF_UNIX, SOCK_STREAM, 0, sv) == -1) { 537 error_setg_errno(errp, errno, "socketpair() failed"); 538 return -1; 539 } 540 541 /* try to launch bridge helper */ 542 pid = fork(); 543 if (pid < 0) { 544 error_setg_errno(errp, errno, "Can't fork bridge helper"); 545 return -1; 546 } 547 if (pid == 0) { 548 int open_max = sysconf(_SC_OPEN_MAX), i; 549 char *fd_buf = NULL; 550 char *br_buf = NULL; 551 char *helper_cmd = NULL; 552 553 for (i = 3; i < open_max; i++) { 554 if (i != sv[1]) { 555 close(i); 556 } 557 } 558 559 fd_buf = g_strdup_printf("%s%d", "--fd=", sv[1]); 560 561 if (strrchr(helper, ' ') || strrchr(helper, '\t')) { 562 /* assume helper is a command */ 563 564 if (strstr(helper, "--br=") == NULL) { 565 br_buf = g_strdup_printf("%s%s", "--br=", bridge); 566 } 567 568 helper_cmd = g_strdup_printf("%s %s %s %s", helper, 569 "--use-vnet", fd_buf, br_buf ? br_buf : ""); 570 571 parg = args; 572 *parg++ = (char *)"sh"; 573 *parg++ = (char *)"-c"; 574 *parg++ = helper_cmd; 575 *parg++ = NULL; 576 577 execv("/bin/sh", args); 578 g_free(helper_cmd); 579 } else { 580 /* assume helper is just the executable path name */ 581 582 br_buf = g_strdup_printf("%s%s", "--br=", bridge); 583 584 parg = args; 585 *parg++ = (char *)helper; 586 *parg++ = (char *)"--use-vnet"; 587 *parg++ = fd_buf; 588 *parg++ = br_buf; 589 *parg++ = NULL; 590 591 execv(helper, args); 592 } 593 g_free(fd_buf); 594 g_free(br_buf); 595 _exit(1); 596 597 } else { 598 int fd; 599 int saved_errno; 600 601 close(sv[1]); 602 603 fd = RETRY_ON_EINTR(recv_fd(sv[0])); 604 saved_errno = errno; 605 606 close(sv[0]); 607 608 while (waitpid(pid, &status, 0) != pid) { 609 /* loop */ 610 } 611 sigprocmask(SIG_SETMASK, &oldmask, NULL); 612 if (fd < 0) { 613 error_setg_errno(errp, saved_errno, 614 "failed to recv file descriptor"); 615 return -1; 616 } 617 if (!WIFEXITED(status) || WEXITSTATUS(status) != 0) { 618 error_setg(errp, "bridge helper failed"); 619 return -1; 620 } 621 return fd; 622 } 623 } 624 625 int net_init_bridge(const Netdev *netdev, const char *name, 626 NetClientState *peer, Error **errp) 627 { 628 const NetdevBridgeOptions *bridge; 629 const char *helper, *br; 630 TAPState *s; 631 int fd, vnet_hdr; 632 633 assert(netdev->type == NET_CLIENT_DRIVER_BRIDGE); 634 bridge = &netdev->u.bridge; 635 helper = bridge->helper; 636 br = bridge->br ?: DEFAULT_BRIDGE_INTERFACE; 637 638 fd = net_bridge_run_helper(helper, br, errp); 639 if (fd == -1) { 640 return -1; 641 } 642 643 if (!g_unix_set_fd_nonblocking(fd, true, NULL)) { 644 error_setg_errno(errp, errno, "Failed to set FD nonblocking"); 645 return -1; 646 } 647 vnet_hdr = tap_probe_vnet_hdr(fd, errp); 648 if (vnet_hdr < 0) { 649 close(fd); 650 return -1; 651 } 652 s = net_tap_fd_init(peer, "bridge", name, fd, vnet_hdr); 653 654 qemu_set_info_str(&s->nc, "helper=%s,br=%s", helper, br); 655 656 return 0; 657 } 658 659 static int net_tap_init(const NetdevTapOptions *tap, int *vnet_hdr, 660 const char *setup_script, char *ifname, 661 size_t ifname_sz, int mq_required, Error **errp) 662 { 663 Error *err = NULL; 664 int fd, vnet_hdr_required; 665 666 if (tap->has_vnet_hdr) { 667 *vnet_hdr = tap->vnet_hdr; 668 vnet_hdr_required = *vnet_hdr; 669 } else { 670 *vnet_hdr = 1; 671 vnet_hdr_required = 0; 672 } 673 674 fd = RETRY_ON_EINTR(tap_open(ifname, ifname_sz, vnet_hdr, vnet_hdr_required, 675 mq_required, errp)); 676 if (fd < 0) { 677 return -1; 678 } 679 680 if (setup_script && 681 setup_script[0] != '\0' && 682 strcmp(setup_script, "no") != 0) { 683 launch_script(setup_script, ifname, fd, &err); 684 if (err) { 685 error_propagate(errp, err); 686 close(fd); 687 return -1; 688 } 689 } 690 691 return fd; 692 } 693 694 #define MAX_TAP_QUEUES 1024 695 696 static void net_init_tap_one(const NetdevTapOptions *tap, NetClientState *peer, 697 const char *model, const char *name, 698 const char *ifname, const char *script, 699 const char *downscript, const char *vhostfdname, 700 int vnet_hdr, int fd, Error **errp) 701 { 702 Error *err = NULL; 703 TAPState *s = net_tap_fd_init(peer, model, name, fd, vnet_hdr); 704 int vhostfd; 705 706 tap_set_sndbuf(s->fd, tap, &err); 707 if (err) { 708 error_propagate(errp, err); 709 goto failed; 710 } 711 712 if (tap->fd || tap->fds) { 713 qemu_set_info_str(&s->nc, "fd=%d", fd); 714 } else if (tap->helper) { 715 qemu_set_info_str(&s->nc, "helper=%s", tap->helper); 716 } else { 717 qemu_set_info_str(&s->nc, "ifname=%s,script=%s,downscript=%s", ifname, 718 script, downscript); 719 720 if (strcmp(downscript, "no") != 0) { 721 snprintf(s->down_script, sizeof(s->down_script), "%s", downscript); 722 snprintf(s->down_script_arg, sizeof(s->down_script_arg), 723 "%s", ifname); 724 } 725 } 726 727 if (tap->has_vhost ? tap->vhost : 728 vhostfdname || (tap->has_vhostforce && tap->vhostforce)) { 729 VhostNetOptions options; 730 731 options.backend_type = VHOST_BACKEND_TYPE_KERNEL; 732 options.net_backend = &s->nc; 733 if (tap->has_poll_us) { 734 options.busyloop_timeout = tap->poll_us; 735 } else { 736 options.busyloop_timeout = 0; 737 } 738 739 if (vhostfdname) { 740 vhostfd = monitor_fd_param(monitor_cur(), vhostfdname, &err); 741 if (vhostfd == -1) { 742 error_propagate(errp, err); 743 goto failed; 744 } 745 if (!g_unix_set_fd_nonblocking(vhostfd, true, NULL)) { 746 error_setg_errno(errp, errno, "%s: Can't use file descriptor %d", 747 name, fd); 748 goto failed; 749 } 750 } else { 751 vhostfd = open("/dev/vhost-net", O_RDWR); 752 if (vhostfd < 0) { 753 error_setg_errno(errp, errno, 754 "tap: open vhost char device failed"); 755 goto failed; 756 } 757 if (!g_unix_set_fd_nonblocking(vhostfd, true, NULL)) { 758 error_setg_errno(errp, errno, "Failed to set FD nonblocking"); 759 goto failed; 760 } 761 } 762 options.opaque = (void *)(uintptr_t)vhostfd; 763 options.nvqs = 2; 764 765 s->vhost_net = vhost_net_init(&options); 766 if (!s->vhost_net) { 767 error_setg(errp, 768 "vhost-net requested but could not be initialized"); 769 goto failed; 770 } 771 } else if (vhostfdname) { 772 error_setg(errp, "vhostfd(s)= is not valid without vhost"); 773 goto failed; 774 } 775 776 return; 777 778 failed: 779 qemu_del_net_client(&s->nc); 780 } 781 782 static int get_fds(char *str, char *fds[], int max) 783 { 784 char *ptr = str, *this; 785 size_t len = strlen(str); 786 int i = 0; 787 788 while (i < max && ptr < str + len) { 789 this = strchr(ptr, ':'); 790 791 if (this == NULL) { 792 fds[i] = g_strdup(ptr); 793 } else { 794 fds[i] = g_strndup(ptr, this - ptr); 795 } 796 797 i++; 798 if (this == NULL) { 799 break; 800 } else { 801 ptr = this + 1; 802 } 803 } 804 805 return i; 806 } 807 808 int net_init_tap(const Netdev *netdev, const char *name, 809 NetClientState *peer, Error **errp) 810 { 811 const NetdevTapOptions *tap; 812 int fd, vnet_hdr = 0, i = 0, queues; 813 /* for the no-fd, no-helper case */ 814 const char *script; 815 const char *downscript; 816 Error *err = NULL; 817 const char *vhostfdname; 818 char ifname[128]; 819 int ret = 0; 820 821 assert(netdev->type == NET_CLIENT_DRIVER_TAP); 822 tap = &netdev->u.tap; 823 queues = tap->has_queues ? tap->queues : 1; 824 vhostfdname = tap->vhostfd; 825 script = tap->script; 826 downscript = tap->downscript; 827 828 /* QEMU hubs do not support multiqueue tap, in this case peer is set. 829 * For -netdev, peer is always NULL. */ 830 if (peer && (tap->has_queues || tap->fds || tap->vhostfds)) { 831 error_setg(errp, "Multiqueue tap cannot be used with hubs"); 832 return -1; 833 } 834 835 if (tap->fd) { 836 if (tap->ifname || tap->script || tap->downscript || 837 tap->has_vnet_hdr || tap->helper || tap->has_queues || 838 tap->fds || tap->vhostfds) { 839 error_setg(errp, "ifname=, script=, downscript=, vnet_hdr=, " 840 "helper=, queues=, fds=, and vhostfds= " 841 "are invalid with fd="); 842 return -1; 843 } 844 845 fd = monitor_fd_param(monitor_cur(), tap->fd, errp); 846 if (fd == -1) { 847 return -1; 848 } 849 850 if (!g_unix_set_fd_nonblocking(fd, true, NULL)) { 851 error_setg_errno(errp, errno, "%s: Can't use file descriptor %d", 852 name, fd); 853 close(fd); 854 return -1; 855 } 856 857 vnet_hdr = tap_probe_vnet_hdr(fd, errp); 858 if (vnet_hdr < 0) { 859 close(fd); 860 return -1; 861 } 862 863 net_init_tap_one(tap, peer, "tap", name, NULL, 864 script, downscript, 865 vhostfdname, vnet_hdr, fd, &err); 866 if (err) { 867 error_propagate(errp, err); 868 close(fd); 869 return -1; 870 } 871 } else if (tap->fds) { 872 char **fds; 873 char **vhost_fds; 874 int nfds = 0, nvhosts = 0; 875 876 if (tap->ifname || tap->script || tap->downscript || 877 tap->has_vnet_hdr || tap->helper || tap->has_queues || 878 tap->vhostfd) { 879 error_setg(errp, "ifname=, script=, downscript=, vnet_hdr=, " 880 "helper=, queues=, and vhostfd= " 881 "are invalid with fds="); 882 return -1; 883 } 884 885 fds = g_new0(char *, MAX_TAP_QUEUES); 886 vhost_fds = g_new0(char *, MAX_TAP_QUEUES); 887 888 nfds = get_fds(tap->fds, fds, MAX_TAP_QUEUES); 889 if (tap->vhostfds) { 890 nvhosts = get_fds(tap->vhostfds, vhost_fds, MAX_TAP_QUEUES); 891 if (nfds != nvhosts) { 892 error_setg(errp, "The number of fds passed does not match " 893 "the number of vhostfds passed"); 894 ret = -1; 895 goto free_fail; 896 } 897 } 898 899 for (i = 0; i < nfds; i++) { 900 fd = monitor_fd_param(monitor_cur(), fds[i], errp); 901 if (fd == -1) { 902 ret = -1; 903 goto free_fail; 904 } 905 906 ret = g_unix_set_fd_nonblocking(fd, true, NULL); 907 if (!ret) { 908 error_setg_errno(errp, errno, "%s: Can't use file descriptor %d", 909 name, fd); 910 goto free_fail; 911 } 912 913 if (i == 0) { 914 vnet_hdr = tap_probe_vnet_hdr(fd, errp); 915 if (vnet_hdr < 0) { 916 ret = -1; 917 goto free_fail; 918 } 919 } else if (vnet_hdr != tap_probe_vnet_hdr(fd, NULL)) { 920 error_setg(errp, 921 "vnet_hdr not consistent across given tap fds"); 922 ret = -1; 923 goto free_fail; 924 } 925 926 net_init_tap_one(tap, peer, "tap", name, ifname, 927 script, downscript, 928 tap->vhostfds ? vhost_fds[i] : NULL, 929 vnet_hdr, fd, &err); 930 if (err) { 931 error_propagate(errp, err); 932 ret = -1; 933 goto free_fail; 934 } 935 } 936 937 free_fail: 938 for (i = 0; i < nvhosts; i++) { 939 g_free(vhost_fds[i]); 940 } 941 for (i = 0; i < nfds; i++) { 942 g_free(fds[i]); 943 } 944 g_free(fds); 945 g_free(vhost_fds); 946 return ret; 947 } else if (tap->helper) { 948 if (tap->ifname || tap->script || tap->downscript || 949 tap->has_vnet_hdr || tap->has_queues || tap->vhostfds) { 950 error_setg(errp, "ifname=, script=, downscript=, vnet_hdr=, " 951 "queues=, and vhostfds= are invalid with helper="); 952 return -1; 953 } 954 955 fd = net_bridge_run_helper(tap->helper, 956 tap->br ?: DEFAULT_BRIDGE_INTERFACE, 957 errp); 958 if (fd == -1) { 959 return -1; 960 } 961 962 if (!g_unix_set_fd_nonblocking(fd, true, NULL)) { 963 error_setg_errno(errp, errno, "Failed to set FD nonblocking"); 964 return -1; 965 } 966 vnet_hdr = tap_probe_vnet_hdr(fd, errp); 967 if (vnet_hdr < 0) { 968 close(fd); 969 return -1; 970 } 971 972 net_init_tap_one(tap, peer, "bridge", name, ifname, 973 script, downscript, vhostfdname, 974 vnet_hdr, fd, &err); 975 if (err) { 976 error_propagate(errp, err); 977 close(fd); 978 return -1; 979 } 980 } else { 981 g_autofree char *default_script = NULL; 982 g_autofree char *default_downscript = NULL; 983 if (tap->vhostfds) { 984 error_setg(errp, "vhostfds= is invalid if fds= wasn't specified"); 985 return -1; 986 } 987 988 if (!script) { 989 script = default_script = get_relocated_path(DEFAULT_NETWORK_SCRIPT); 990 } 991 if (!downscript) { 992 downscript = default_downscript = 993 get_relocated_path(DEFAULT_NETWORK_DOWN_SCRIPT); 994 } 995 996 if (tap->ifname) { 997 pstrcpy(ifname, sizeof ifname, tap->ifname); 998 } else { 999 ifname[0] = '\0'; 1000 } 1001 1002 for (i = 0; i < queues; i++) { 1003 fd = net_tap_init(tap, &vnet_hdr, i >= 1 ? "no" : script, 1004 ifname, sizeof ifname, queues > 1, errp); 1005 if (fd == -1) { 1006 return -1; 1007 } 1008 1009 if (queues > 1 && i == 0 && !tap->ifname) { 1010 if (tap_fd_get_ifname(fd, ifname)) { 1011 error_setg(errp, "Fail to get ifname"); 1012 close(fd); 1013 return -1; 1014 } 1015 } 1016 1017 net_init_tap_one(tap, peer, "tap", name, ifname, 1018 i >= 1 ? "no" : script, 1019 i >= 1 ? "no" : downscript, 1020 vhostfdname, vnet_hdr, fd, &err); 1021 if (err) { 1022 error_propagate(errp, err); 1023 close(fd); 1024 return -1; 1025 } 1026 } 1027 } 1028 1029 return 0; 1030 } 1031 1032 VHostNetState *tap_get_vhost_net(NetClientState *nc) 1033 { 1034 TAPState *s = DO_UPCAST(TAPState, nc, nc); 1035 assert(nc->info->type == NET_CLIENT_DRIVER_TAP); 1036 return s->vhost_net; 1037 } 1038 1039 int tap_enable(NetClientState *nc) 1040 { 1041 TAPState *s = DO_UPCAST(TAPState, nc, nc); 1042 int ret; 1043 1044 if (s->enabled) { 1045 return 0; 1046 } else { 1047 ret = tap_fd_enable(s->fd); 1048 if (ret == 0) { 1049 s->enabled = true; 1050 tap_update_fd_handler(s); 1051 } 1052 return ret; 1053 } 1054 } 1055 1056 int tap_disable(NetClientState *nc) 1057 { 1058 TAPState *s = DO_UPCAST(TAPState, nc, nc); 1059 int ret; 1060 1061 if (s->enabled == 0) { 1062 return 0; 1063 } else { 1064 ret = tap_fd_disable(s->fd); 1065 if (ret == 0) { 1066 qemu_purge_queued_packets(nc); 1067 s->enabled = false; 1068 tap_update_fd_handler(s); 1069 } 1070 return ret; 1071 } 1072 } 1073