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 TAPState *s = DO_UPCAST(TAPState, nc, nc); 263 264 assert(nc->info->type == NET_CLIENT_DRIVER_TAP); 265 266 return !!tap_probe_vnet_hdr_len(s->fd, len); 267 } 268 269 static int tap_get_vnet_hdr_len(NetClientState *nc) 270 { 271 TAPState *s = DO_UPCAST(TAPState, nc, nc); 272 273 return s->host_vnet_hdr_len; 274 } 275 276 static void tap_set_vnet_hdr_len(NetClientState *nc, int len) 277 { 278 TAPState *s = DO_UPCAST(TAPState, nc, nc); 279 280 assert(nc->info->type == NET_CLIENT_DRIVER_TAP); 281 assert(len == sizeof(struct virtio_net_hdr_mrg_rxbuf) || 282 len == sizeof(struct virtio_net_hdr) || 283 len == sizeof(struct virtio_net_hdr_v1_hash)); 284 285 tap_fd_set_vnet_hdr_len(s->fd, len); 286 s->host_vnet_hdr_len = len; 287 } 288 289 static bool tap_get_using_vnet_hdr(NetClientState *nc) 290 { 291 TAPState *s = DO_UPCAST(TAPState, nc, nc); 292 293 return s->using_vnet_hdr; 294 } 295 296 static void tap_using_vnet_hdr(NetClientState *nc, bool using_vnet_hdr) 297 { 298 TAPState *s = DO_UPCAST(TAPState, nc, nc); 299 300 assert(nc->info->type == NET_CLIENT_DRIVER_TAP); 301 assert(!!s->host_vnet_hdr_len == using_vnet_hdr); 302 303 s->using_vnet_hdr = using_vnet_hdr; 304 } 305 306 static int tap_set_vnet_le(NetClientState *nc, bool is_le) 307 { 308 TAPState *s = DO_UPCAST(TAPState, nc, nc); 309 310 return tap_fd_set_vnet_le(s->fd, is_le); 311 } 312 313 static int tap_set_vnet_be(NetClientState *nc, bool is_be) 314 { 315 TAPState *s = DO_UPCAST(TAPState, nc, nc); 316 317 return tap_fd_set_vnet_be(s->fd, is_be); 318 } 319 320 static void tap_set_offload(NetClientState *nc, int csum, int tso4, 321 int tso6, int ecn, int ufo, int uso4, int uso6) 322 { 323 TAPState *s = DO_UPCAST(TAPState, nc, nc); 324 if (s->fd < 0) { 325 return; 326 } 327 328 tap_fd_set_offload(s->fd, csum, tso4, tso6, ecn, ufo, uso4, uso6); 329 } 330 331 static void tap_exit_notify(Notifier *notifier, void *data) 332 { 333 TAPState *s = container_of(notifier, TAPState, exit); 334 Error *err = NULL; 335 336 if (s->down_script[0]) { 337 launch_script(s->down_script, s->down_script_arg, s->fd, &err); 338 if (err) { 339 error_report_err(err); 340 } 341 } 342 } 343 344 static void tap_cleanup(NetClientState *nc) 345 { 346 TAPState *s = DO_UPCAST(TAPState, nc, nc); 347 348 if (s->vhost_net) { 349 vhost_net_cleanup(s->vhost_net); 350 g_free(s->vhost_net); 351 s->vhost_net = NULL; 352 } 353 354 qemu_purge_queued_packets(nc); 355 356 tap_exit_notify(&s->exit, NULL); 357 qemu_remove_exit_notifier(&s->exit); 358 359 tap_read_poll(s, false); 360 tap_write_poll(s, false); 361 close(s->fd); 362 s->fd = -1; 363 } 364 365 static void tap_poll(NetClientState *nc, bool enable) 366 { 367 TAPState *s = DO_UPCAST(TAPState, nc, nc); 368 tap_read_poll(s, enable); 369 tap_write_poll(s, enable); 370 } 371 372 static bool tap_set_steering_ebpf(NetClientState *nc, int prog_fd) 373 { 374 TAPState *s = DO_UPCAST(TAPState, nc, nc); 375 assert(nc->info->type == NET_CLIENT_DRIVER_TAP); 376 377 return tap_fd_set_steering_ebpf(s->fd, prog_fd) == 0; 378 } 379 380 int tap_get_fd(NetClientState *nc) 381 { 382 TAPState *s = DO_UPCAST(TAPState, nc, nc); 383 assert(nc->info->type == NET_CLIENT_DRIVER_TAP); 384 return s->fd; 385 } 386 387 /* fd support */ 388 389 static NetClientInfo net_tap_info = { 390 .type = NET_CLIENT_DRIVER_TAP, 391 .size = sizeof(TAPState), 392 .receive = tap_receive, 393 .receive_raw = tap_receive_raw, 394 .receive_iov = tap_receive_iov, 395 .poll = tap_poll, 396 .cleanup = tap_cleanup, 397 .has_ufo = tap_has_ufo, 398 .has_uso = tap_has_uso, 399 .has_vnet_hdr = tap_has_vnet_hdr, 400 .has_vnet_hdr_len = tap_has_vnet_hdr_len, 401 .get_using_vnet_hdr = tap_get_using_vnet_hdr, 402 .using_vnet_hdr = tap_using_vnet_hdr, 403 .set_offload = tap_set_offload, 404 .get_vnet_hdr_len = tap_get_vnet_hdr_len, 405 .set_vnet_hdr_len = tap_set_vnet_hdr_len, 406 .set_vnet_le = tap_set_vnet_le, 407 .set_vnet_be = tap_set_vnet_be, 408 .set_steering_ebpf = tap_set_steering_ebpf, 409 }; 410 411 static TAPState *net_tap_fd_init(NetClientState *peer, 412 const char *model, 413 const char *name, 414 int fd, 415 int vnet_hdr) 416 { 417 NetClientState *nc; 418 TAPState *s; 419 420 nc = qemu_new_net_client(&net_tap_info, peer, model, name); 421 422 s = DO_UPCAST(TAPState, nc, nc); 423 424 s->fd = fd; 425 s->host_vnet_hdr_len = vnet_hdr ? sizeof(struct virtio_net_hdr) : 0; 426 s->using_vnet_hdr = false; 427 s->has_ufo = tap_probe_has_ufo(s->fd); 428 s->has_uso = tap_probe_has_uso(s->fd); 429 s->enabled = true; 430 tap_set_offload(&s->nc, 0, 0, 0, 0, 0, 0, 0); 431 /* 432 * Make sure host header length is set correctly in tap: 433 * it might have been modified by another instance of qemu. 434 */ 435 if (tap_probe_vnet_hdr_len(s->fd, s->host_vnet_hdr_len)) { 436 tap_fd_set_vnet_hdr_len(s->fd, s->host_vnet_hdr_len); 437 } 438 tap_read_poll(s, true); 439 s->vhost_net = NULL; 440 441 s->exit.notify = tap_exit_notify; 442 qemu_add_exit_notifier(&s->exit); 443 444 return s; 445 } 446 447 static void launch_script(const char *setup_script, const char *ifname, 448 int fd, Error **errp) 449 { 450 int pid, status; 451 char *args[3]; 452 char **parg; 453 454 /* try to launch network script */ 455 pid = fork(); 456 if (pid < 0) { 457 error_setg_errno(errp, errno, "could not launch network script %s", 458 setup_script); 459 return; 460 } 461 if (pid == 0) { 462 int open_max = sysconf(_SC_OPEN_MAX), i; 463 464 for (i = 3; i < open_max; i++) { 465 if (i != fd) { 466 close(i); 467 } 468 } 469 parg = args; 470 *parg++ = (char *)setup_script; 471 *parg++ = (char *)ifname; 472 *parg = NULL; 473 execv(setup_script, args); 474 _exit(1); 475 } else { 476 while (waitpid(pid, &status, 0) != pid) { 477 /* loop */ 478 } 479 480 if (WIFEXITED(status) && WEXITSTATUS(status) == 0) { 481 return; 482 } 483 error_setg(errp, "network script %s failed with status %d", 484 setup_script, status); 485 } 486 } 487 488 static int recv_fd(int c) 489 { 490 int fd; 491 uint8_t msgbuf[CMSG_SPACE(sizeof(fd))]; 492 struct msghdr msg = { 493 .msg_control = msgbuf, 494 .msg_controllen = sizeof(msgbuf), 495 }; 496 struct cmsghdr *cmsg; 497 struct iovec iov; 498 uint8_t req[1]; 499 ssize_t len; 500 501 cmsg = CMSG_FIRSTHDR(&msg); 502 cmsg->cmsg_level = SOL_SOCKET; 503 cmsg->cmsg_type = SCM_RIGHTS; 504 cmsg->cmsg_len = CMSG_LEN(sizeof(fd)); 505 msg.msg_controllen = cmsg->cmsg_len; 506 507 iov.iov_base = req; 508 iov.iov_len = sizeof(req); 509 510 msg.msg_iov = &iov; 511 msg.msg_iovlen = 1; 512 513 len = recvmsg(c, &msg, 0); 514 if (len > 0) { 515 memcpy(&fd, CMSG_DATA(cmsg), sizeof(fd)); 516 return fd; 517 } 518 519 return len; 520 } 521 522 static int net_bridge_run_helper(const char *helper, const char *bridge, 523 Error **errp) 524 { 525 sigset_t oldmask, mask; 526 g_autofree char *default_helper = NULL; 527 int pid, status; 528 char *args[5]; 529 char **parg; 530 int sv[2]; 531 532 sigemptyset(&mask); 533 sigaddset(&mask, SIGCHLD); 534 sigprocmask(SIG_BLOCK, &mask, &oldmask); 535 536 if (!helper) { 537 helper = default_helper = get_relocated_path(DEFAULT_BRIDGE_HELPER); 538 } 539 540 if (socketpair(PF_UNIX, SOCK_STREAM, 0, sv) == -1) { 541 error_setg_errno(errp, errno, "socketpair() failed"); 542 return -1; 543 } 544 545 /* try to launch bridge helper */ 546 pid = fork(); 547 if (pid < 0) { 548 error_setg_errno(errp, errno, "Can't fork bridge helper"); 549 return -1; 550 } 551 if (pid == 0) { 552 int open_max = sysconf(_SC_OPEN_MAX), i; 553 char *fd_buf = NULL; 554 char *br_buf = NULL; 555 char *helper_cmd = NULL; 556 557 for (i = 3; i < open_max; i++) { 558 if (i != sv[1]) { 559 close(i); 560 } 561 } 562 563 fd_buf = g_strdup_printf("%s%d", "--fd=", sv[1]); 564 565 if (strrchr(helper, ' ') || strrchr(helper, '\t')) { 566 /* assume helper is a command */ 567 568 if (strstr(helper, "--br=") == NULL) { 569 br_buf = g_strdup_printf("%s%s", "--br=", bridge); 570 } 571 572 helper_cmd = g_strdup_printf("%s %s %s %s", helper, 573 "--use-vnet", fd_buf, br_buf ? br_buf : ""); 574 575 parg = args; 576 *parg++ = (char *)"sh"; 577 *parg++ = (char *)"-c"; 578 *parg++ = helper_cmd; 579 *parg++ = NULL; 580 581 execv("/bin/sh", args); 582 g_free(helper_cmd); 583 } else { 584 /* assume helper is just the executable path name */ 585 586 br_buf = g_strdup_printf("%s%s", "--br=", bridge); 587 588 parg = args; 589 *parg++ = (char *)helper; 590 *parg++ = (char *)"--use-vnet"; 591 *parg++ = fd_buf; 592 *parg++ = br_buf; 593 *parg++ = NULL; 594 595 execv(helper, args); 596 } 597 g_free(fd_buf); 598 g_free(br_buf); 599 _exit(1); 600 601 } else { 602 int fd; 603 int saved_errno; 604 605 close(sv[1]); 606 607 fd = RETRY_ON_EINTR(recv_fd(sv[0])); 608 saved_errno = errno; 609 610 close(sv[0]); 611 612 while (waitpid(pid, &status, 0) != pid) { 613 /* loop */ 614 } 615 sigprocmask(SIG_SETMASK, &oldmask, NULL); 616 if (fd < 0) { 617 error_setg_errno(errp, saved_errno, 618 "failed to recv file descriptor"); 619 return -1; 620 } 621 if (!WIFEXITED(status) || WEXITSTATUS(status) != 0) { 622 error_setg(errp, "bridge helper failed"); 623 return -1; 624 } 625 return fd; 626 } 627 } 628 629 int net_init_bridge(const Netdev *netdev, const char *name, 630 NetClientState *peer, Error **errp) 631 { 632 const NetdevBridgeOptions *bridge; 633 const char *helper, *br; 634 TAPState *s; 635 int fd, vnet_hdr; 636 637 assert(netdev->type == NET_CLIENT_DRIVER_BRIDGE); 638 bridge = &netdev->u.bridge; 639 helper = bridge->helper; 640 br = bridge->br ?: DEFAULT_BRIDGE_INTERFACE; 641 642 fd = net_bridge_run_helper(helper, br, errp); 643 if (fd == -1) { 644 return -1; 645 } 646 647 if (!g_unix_set_fd_nonblocking(fd, true, NULL)) { 648 error_setg_errno(errp, errno, "Failed to set FD nonblocking"); 649 return -1; 650 } 651 vnet_hdr = tap_probe_vnet_hdr(fd, errp); 652 if (vnet_hdr < 0) { 653 close(fd); 654 return -1; 655 } 656 s = net_tap_fd_init(peer, "bridge", name, fd, vnet_hdr); 657 658 qemu_set_info_str(&s->nc, "helper=%s,br=%s", helper, br); 659 660 return 0; 661 } 662 663 static int net_tap_init(const NetdevTapOptions *tap, int *vnet_hdr, 664 const char *setup_script, char *ifname, 665 size_t ifname_sz, int mq_required, Error **errp) 666 { 667 Error *err = NULL; 668 int fd, vnet_hdr_required; 669 670 if (tap->has_vnet_hdr) { 671 *vnet_hdr = tap->vnet_hdr; 672 vnet_hdr_required = *vnet_hdr; 673 } else { 674 *vnet_hdr = 1; 675 vnet_hdr_required = 0; 676 } 677 678 fd = RETRY_ON_EINTR(tap_open(ifname, ifname_sz, vnet_hdr, vnet_hdr_required, 679 mq_required, errp)); 680 if (fd < 0) { 681 return -1; 682 } 683 684 if (setup_script && 685 setup_script[0] != '\0' && 686 strcmp(setup_script, "no") != 0) { 687 launch_script(setup_script, ifname, fd, &err); 688 if (err) { 689 error_propagate(errp, err); 690 close(fd); 691 return -1; 692 } 693 } 694 695 return fd; 696 } 697 698 #define MAX_TAP_QUEUES 1024 699 700 static void net_init_tap_one(const NetdevTapOptions *tap, NetClientState *peer, 701 const char *model, const char *name, 702 const char *ifname, const char *script, 703 const char *downscript, const char *vhostfdname, 704 int vnet_hdr, int fd, Error **errp) 705 { 706 Error *err = NULL; 707 TAPState *s = net_tap_fd_init(peer, model, name, fd, vnet_hdr); 708 int vhostfd; 709 710 tap_set_sndbuf(s->fd, tap, &err); 711 if (err) { 712 error_propagate(errp, err); 713 goto failed; 714 } 715 716 if (tap->fd || tap->fds) { 717 qemu_set_info_str(&s->nc, "fd=%d", fd); 718 } else if (tap->helper) { 719 qemu_set_info_str(&s->nc, "helper=%s", tap->helper); 720 } else { 721 qemu_set_info_str(&s->nc, "ifname=%s,script=%s,downscript=%s", ifname, 722 script, downscript); 723 724 if (strcmp(downscript, "no") != 0) { 725 snprintf(s->down_script, sizeof(s->down_script), "%s", downscript); 726 snprintf(s->down_script_arg, sizeof(s->down_script_arg), 727 "%s", ifname); 728 } 729 } 730 731 if (tap->has_vhost ? tap->vhost : 732 vhostfdname || (tap->has_vhostforce && tap->vhostforce)) { 733 VhostNetOptions options; 734 735 options.backend_type = VHOST_BACKEND_TYPE_KERNEL; 736 options.net_backend = &s->nc; 737 if (tap->has_poll_us) { 738 options.busyloop_timeout = tap->poll_us; 739 } else { 740 options.busyloop_timeout = 0; 741 } 742 743 if (vhostfdname) { 744 vhostfd = monitor_fd_param(monitor_cur(), vhostfdname, &err); 745 if (vhostfd == -1) { 746 if (tap->has_vhostforce && tap->vhostforce) { 747 error_propagate(errp, err); 748 } else { 749 warn_report_err(err); 750 } 751 goto failed; 752 } 753 if (!g_unix_set_fd_nonblocking(vhostfd, true, NULL)) { 754 error_setg_errno(errp, errno, "%s: Can't use file descriptor %d", 755 name, fd); 756 goto failed; 757 } 758 } else { 759 vhostfd = open("/dev/vhost-net", O_RDWR); 760 if (vhostfd < 0) { 761 if (tap->has_vhostforce && tap->vhostforce) { 762 error_setg_errno(errp, errno, 763 "tap: open vhost char device failed"); 764 } else { 765 warn_report("tap: open vhost char device failed: %s", 766 strerror(errno)); 767 } 768 goto failed; 769 } 770 if (!g_unix_set_fd_nonblocking(vhostfd, true, NULL)) { 771 error_setg_errno(errp, errno, "Failed to set FD nonblocking"); 772 goto failed; 773 } 774 } 775 options.opaque = (void *)(uintptr_t)vhostfd; 776 options.nvqs = 2; 777 778 s->vhost_net = vhost_net_init(&options); 779 if (!s->vhost_net) { 780 if (tap->has_vhostforce && tap->vhostforce) { 781 error_setg(errp, VHOST_NET_INIT_FAILED); 782 } else { 783 warn_report(VHOST_NET_INIT_FAILED); 784 } 785 goto failed; 786 } 787 } else if (vhostfdname) { 788 error_setg(errp, "vhostfd(s)= is not valid without vhost"); 789 goto failed; 790 } 791 792 return; 793 794 failed: 795 qemu_del_net_client(&s->nc); 796 } 797 798 static int get_fds(char *str, char *fds[], int max) 799 { 800 char *ptr = str, *this; 801 size_t len = strlen(str); 802 int i = 0; 803 804 while (i < max && ptr < str + len) { 805 this = strchr(ptr, ':'); 806 807 if (this == NULL) { 808 fds[i] = g_strdup(ptr); 809 } else { 810 fds[i] = g_strndup(ptr, this - ptr); 811 } 812 813 i++; 814 if (this == NULL) { 815 break; 816 } else { 817 ptr = this + 1; 818 } 819 } 820 821 return i; 822 } 823 824 int net_init_tap(const Netdev *netdev, const char *name, 825 NetClientState *peer, Error **errp) 826 { 827 const NetdevTapOptions *tap; 828 int fd, vnet_hdr = 0, i = 0, queues; 829 /* for the no-fd, no-helper case */ 830 const char *script; 831 const char *downscript; 832 Error *err = NULL; 833 const char *vhostfdname; 834 char ifname[128]; 835 int ret = 0; 836 837 assert(netdev->type == NET_CLIENT_DRIVER_TAP); 838 tap = &netdev->u.tap; 839 queues = tap->has_queues ? tap->queues : 1; 840 vhostfdname = tap->vhostfd; 841 script = tap->script; 842 downscript = tap->downscript; 843 844 /* QEMU hubs do not support multiqueue tap, in this case peer is set. 845 * For -netdev, peer is always NULL. */ 846 if (peer && (tap->has_queues || tap->fds || tap->vhostfds)) { 847 error_setg(errp, "Multiqueue tap cannot be used with hubs"); 848 return -1; 849 } 850 851 if (tap->fd) { 852 if (tap->ifname || tap->script || tap->downscript || 853 tap->has_vnet_hdr || tap->helper || tap->has_queues || 854 tap->fds || tap->vhostfds) { 855 error_setg(errp, "ifname=, script=, downscript=, vnet_hdr=, " 856 "helper=, queues=, fds=, and vhostfds= " 857 "are invalid with fd="); 858 return -1; 859 } 860 861 fd = monitor_fd_param(monitor_cur(), tap->fd, errp); 862 if (fd == -1) { 863 return -1; 864 } 865 866 if (!g_unix_set_fd_nonblocking(fd, true, NULL)) { 867 error_setg_errno(errp, errno, "%s: Can't use file descriptor %d", 868 name, fd); 869 close(fd); 870 return -1; 871 } 872 873 vnet_hdr = tap_probe_vnet_hdr(fd, errp); 874 if (vnet_hdr < 0) { 875 close(fd); 876 return -1; 877 } 878 879 net_init_tap_one(tap, peer, "tap", name, NULL, 880 script, downscript, 881 vhostfdname, vnet_hdr, fd, &err); 882 if (err) { 883 error_propagate(errp, err); 884 close(fd); 885 return -1; 886 } 887 } else if (tap->fds) { 888 char **fds; 889 char **vhost_fds; 890 int nfds = 0, nvhosts = 0; 891 892 if (tap->ifname || tap->script || tap->downscript || 893 tap->has_vnet_hdr || tap->helper || tap->has_queues || 894 tap->vhostfd) { 895 error_setg(errp, "ifname=, script=, downscript=, vnet_hdr=, " 896 "helper=, queues=, and vhostfd= " 897 "are invalid with fds="); 898 return -1; 899 } 900 901 fds = g_new0(char *, MAX_TAP_QUEUES); 902 vhost_fds = g_new0(char *, MAX_TAP_QUEUES); 903 904 nfds = get_fds(tap->fds, fds, MAX_TAP_QUEUES); 905 if (tap->vhostfds) { 906 nvhosts = get_fds(tap->vhostfds, vhost_fds, MAX_TAP_QUEUES); 907 if (nfds != nvhosts) { 908 error_setg(errp, "The number of fds passed does not match " 909 "the number of vhostfds passed"); 910 ret = -1; 911 goto free_fail; 912 } 913 } 914 915 for (i = 0; i < nfds; i++) { 916 fd = monitor_fd_param(monitor_cur(), fds[i], errp); 917 if (fd == -1) { 918 ret = -1; 919 goto free_fail; 920 } 921 922 ret = g_unix_set_fd_nonblocking(fd, true, NULL); 923 if (!ret) { 924 error_setg_errno(errp, errno, "%s: Can't use file descriptor %d", 925 name, fd); 926 goto free_fail; 927 } 928 929 if (i == 0) { 930 vnet_hdr = tap_probe_vnet_hdr(fd, errp); 931 if (vnet_hdr < 0) { 932 ret = -1; 933 goto free_fail; 934 } 935 } else if (vnet_hdr != tap_probe_vnet_hdr(fd, NULL)) { 936 error_setg(errp, 937 "vnet_hdr not consistent across given tap fds"); 938 ret = -1; 939 goto free_fail; 940 } 941 942 net_init_tap_one(tap, peer, "tap", name, ifname, 943 script, downscript, 944 tap->vhostfds ? vhost_fds[i] : NULL, 945 vnet_hdr, fd, &err); 946 if (err) { 947 error_propagate(errp, err); 948 ret = -1; 949 goto free_fail; 950 } 951 } 952 953 free_fail: 954 for (i = 0; i < nvhosts; i++) { 955 g_free(vhost_fds[i]); 956 } 957 for (i = 0; i < nfds; i++) { 958 g_free(fds[i]); 959 } 960 g_free(fds); 961 g_free(vhost_fds); 962 return ret; 963 } else if (tap->helper) { 964 if (tap->ifname || tap->script || tap->downscript || 965 tap->has_vnet_hdr || tap->has_queues || tap->vhostfds) { 966 error_setg(errp, "ifname=, script=, downscript=, vnet_hdr=, " 967 "queues=, and vhostfds= are invalid with helper="); 968 return -1; 969 } 970 971 fd = net_bridge_run_helper(tap->helper, 972 tap->br ?: DEFAULT_BRIDGE_INTERFACE, 973 errp); 974 if (fd == -1) { 975 return -1; 976 } 977 978 if (!g_unix_set_fd_nonblocking(fd, true, NULL)) { 979 error_setg_errno(errp, errno, "Failed to set FD nonblocking"); 980 return -1; 981 } 982 vnet_hdr = tap_probe_vnet_hdr(fd, errp); 983 if (vnet_hdr < 0) { 984 close(fd); 985 return -1; 986 } 987 988 net_init_tap_one(tap, peer, "bridge", name, ifname, 989 script, downscript, vhostfdname, 990 vnet_hdr, fd, &err); 991 if (err) { 992 error_propagate(errp, err); 993 close(fd); 994 return -1; 995 } 996 } else { 997 g_autofree char *default_script = NULL; 998 g_autofree char *default_downscript = NULL; 999 if (tap->vhostfds) { 1000 error_setg(errp, "vhostfds= is invalid if fds= wasn't specified"); 1001 return -1; 1002 } 1003 1004 if (!script) { 1005 script = default_script = get_relocated_path(DEFAULT_NETWORK_SCRIPT); 1006 } 1007 if (!downscript) { 1008 downscript = default_downscript = 1009 get_relocated_path(DEFAULT_NETWORK_DOWN_SCRIPT); 1010 } 1011 1012 if (tap->ifname) { 1013 pstrcpy(ifname, sizeof ifname, tap->ifname); 1014 } else { 1015 ifname[0] = '\0'; 1016 } 1017 1018 for (i = 0; i < queues; i++) { 1019 fd = net_tap_init(tap, &vnet_hdr, i >= 1 ? "no" : script, 1020 ifname, sizeof ifname, queues > 1, errp); 1021 if (fd == -1) { 1022 return -1; 1023 } 1024 1025 if (queues > 1 && i == 0 && !tap->ifname) { 1026 if (tap_fd_get_ifname(fd, ifname)) { 1027 error_setg(errp, "Fail to get ifname"); 1028 close(fd); 1029 return -1; 1030 } 1031 } 1032 1033 net_init_tap_one(tap, peer, "tap", name, ifname, 1034 i >= 1 ? "no" : script, 1035 i >= 1 ? "no" : downscript, 1036 vhostfdname, vnet_hdr, fd, &err); 1037 if (err) { 1038 error_propagate(errp, err); 1039 close(fd); 1040 return -1; 1041 } 1042 } 1043 } 1044 1045 return 0; 1046 } 1047 1048 VHostNetState *tap_get_vhost_net(NetClientState *nc) 1049 { 1050 TAPState *s = DO_UPCAST(TAPState, nc, nc); 1051 assert(nc->info->type == NET_CLIENT_DRIVER_TAP); 1052 return s->vhost_net; 1053 } 1054 1055 int tap_enable(NetClientState *nc) 1056 { 1057 TAPState *s = DO_UPCAST(TAPState, nc, nc); 1058 int ret; 1059 1060 if (s->enabled) { 1061 return 0; 1062 } else { 1063 ret = tap_fd_enable(s->fd); 1064 if (ret == 0) { 1065 s->enabled = true; 1066 tap_update_fd_handler(s); 1067 } 1068 return ret; 1069 } 1070 } 1071 1072 int tap_disable(NetClientState *nc) 1073 { 1074 TAPState *s = DO_UPCAST(TAPState, nc, nc); 1075 int ret; 1076 1077 if (s->enabled == 0) { 1078 return 0; 1079 } else { 1080 ret = tap_fd_disable(s->fd); 1081 if (ret == 0) { 1082 qemu_purge_queued_packets(nc); 1083 s->enabled = false; 1084 tap_update_fd_handler(s); 1085 } 1086 return ret; 1087 } 1088 } 1089