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-common.h" 42 #include "qemu/cutils.h" 43 #include "qemu/error-report.h" 44 #include "qemu/main-loop.h" 45 #include "qemu/sockets.h" 46 47 #include "net/tap.h" 48 49 #include "net/vhost_net.h" 50 51 typedef struct TAPState { 52 NetClientState nc; 53 int fd; 54 char down_script[1024]; 55 char down_script_arg[128]; 56 uint8_t buf[NET_BUFSIZE]; 57 bool read_poll; 58 bool write_poll; 59 bool using_vnet_hdr; 60 bool has_ufo; 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 do { 107 len = writev(s->fd, iov, iovcnt); 108 } while (len == -1 && errno == EINTR); 109 110 if (len == -1 && errno == EAGAIN) { 111 tap_write_poll(s, true); 112 return 0; 113 } 114 115 return len; 116 } 117 118 static ssize_t tap_receive_iov(NetClientState *nc, const struct iovec *iov, 119 int iovcnt) 120 { 121 TAPState *s = DO_UPCAST(TAPState, nc, nc); 122 const struct iovec *iovp = iov; 123 struct iovec iov_copy[iovcnt + 1]; 124 struct virtio_net_hdr_mrg_rxbuf hdr = { }; 125 126 if (s->host_vnet_hdr_len && !s->using_vnet_hdr) { 127 iov_copy[0].iov_base = &hdr; 128 iov_copy[0].iov_len = s->host_vnet_hdr_len; 129 memcpy(&iov_copy[1], iov, iovcnt * sizeof(*iov)); 130 iovp = iov_copy; 131 iovcnt++; 132 } 133 134 return tap_write_packet(s, iovp, iovcnt); 135 } 136 137 static ssize_t tap_receive_raw(NetClientState *nc, const uint8_t *buf, size_t size) 138 { 139 TAPState *s = DO_UPCAST(TAPState, nc, nc); 140 struct iovec iov[2]; 141 int iovcnt = 0; 142 struct virtio_net_hdr_mrg_rxbuf hdr = { }; 143 144 if (s->host_vnet_hdr_len) { 145 iov[iovcnt].iov_base = &hdr; 146 iov[iovcnt].iov_len = s->host_vnet_hdr_len; 147 iovcnt++; 148 } 149 150 iov[iovcnt].iov_base = (char *)buf; 151 iov[iovcnt].iov_len = size; 152 iovcnt++; 153 154 return tap_write_packet(s, iov, iovcnt); 155 } 156 157 static ssize_t tap_receive(NetClientState *nc, const uint8_t *buf, size_t size) 158 { 159 TAPState *s = DO_UPCAST(TAPState, nc, nc); 160 struct iovec iov[1]; 161 162 if (s->host_vnet_hdr_len && !s->using_vnet_hdr) { 163 return tap_receive_raw(nc, buf, size); 164 } 165 166 iov[0].iov_base = (char *)buf; 167 iov[0].iov_len = size; 168 169 return tap_write_packet(s, iov, 1); 170 } 171 172 #ifndef __sun__ 173 ssize_t tap_read_packet(int tapfd, uint8_t *buf, int maxlen) 174 { 175 return read(tapfd, buf, maxlen); 176 } 177 #endif 178 179 static void tap_send_completed(NetClientState *nc, ssize_t len) 180 { 181 TAPState *s = DO_UPCAST(TAPState, nc, nc); 182 tap_read_poll(s, true); 183 } 184 185 static void tap_send(void *opaque) 186 { 187 TAPState *s = opaque; 188 int size; 189 int packets = 0; 190 191 while (true) { 192 uint8_t *buf = s->buf; 193 uint8_t min_pkt[ETH_ZLEN]; 194 size_t min_pktsz = sizeof(min_pkt); 195 196 size = tap_read_packet(s->fd, s->buf, sizeof(s->buf)); 197 if (size <= 0) { 198 break; 199 } 200 201 if (s->host_vnet_hdr_len && !s->using_vnet_hdr) { 202 buf += s->host_vnet_hdr_len; 203 size -= s->host_vnet_hdr_len; 204 } 205 206 if (net_peer_needs_padding(&s->nc)) { 207 if (eth_pad_short_frame(min_pkt, &min_pktsz, buf, size)) { 208 buf = min_pkt; 209 size = min_pktsz; 210 } 211 } 212 213 size = qemu_send_packet_async(&s->nc, buf, size, tap_send_completed); 214 if (size == 0) { 215 tap_read_poll(s, false); 216 break; 217 } else if (size < 0) { 218 break; 219 } 220 221 /* 222 * When the host keeps receiving more packets while tap_send() is 223 * running we can hog the QEMU global mutex. Limit the number of 224 * packets that are processed per tap_send() callback to prevent 225 * stalling the guest. 226 */ 227 packets++; 228 if (packets >= 50) { 229 break; 230 } 231 } 232 } 233 234 static bool tap_has_ufo(NetClientState *nc) 235 { 236 TAPState *s = DO_UPCAST(TAPState, nc, nc); 237 238 assert(nc->info->type == NET_CLIENT_DRIVER_TAP); 239 240 return s->has_ufo; 241 } 242 243 static bool tap_has_vnet_hdr(NetClientState *nc) 244 { 245 TAPState *s = DO_UPCAST(TAPState, nc, nc); 246 247 assert(nc->info->type == NET_CLIENT_DRIVER_TAP); 248 249 return !!s->host_vnet_hdr_len; 250 } 251 252 static bool tap_has_vnet_hdr_len(NetClientState *nc, int len) 253 { 254 TAPState *s = DO_UPCAST(TAPState, nc, nc); 255 256 assert(nc->info->type == NET_CLIENT_DRIVER_TAP); 257 258 return !!tap_probe_vnet_hdr_len(s->fd, len); 259 } 260 261 static void tap_set_vnet_hdr_len(NetClientState *nc, int len) 262 { 263 TAPState *s = DO_UPCAST(TAPState, nc, nc); 264 265 assert(nc->info->type == NET_CLIENT_DRIVER_TAP); 266 assert(len == sizeof(struct virtio_net_hdr_mrg_rxbuf) || 267 len == sizeof(struct virtio_net_hdr) || 268 len == sizeof(struct virtio_net_hdr_v1_hash)); 269 270 tap_fd_set_vnet_hdr_len(s->fd, len); 271 s->host_vnet_hdr_len = len; 272 } 273 274 static void tap_using_vnet_hdr(NetClientState *nc, bool using_vnet_hdr) 275 { 276 TAPState *s = DO_UPCAST(TAPState, nc, nc); 277 278 assert(nc->info->type == NET_CLIENT_DRIVER_TAP); 279 assert(!!s->host_vnet_hdr_len == using_vnet_hdr); 280 281 s->using_vnet_hdr = using_vnet_hdr; 282 } 283 284 static int tap_set_vnet_le(NetClientState *nc, bool is_le) 285 { 286 TAPState *s = DO_UPCAST(TAPState, nc, nc); 287 288 return tap_fd_set_vnet_le(s->fd, is_le); 289 } 290 291 static int tap_set_vnet_be(NetClientState *nc, bool is_be) 292 { 293 TAPState *s = DO_UPCAST(TAPState, nc, nc); 294 295 return tap_fd_set_vnet_be(s->fd, is_be); 296 } 297 298 static void tap_set_offload(NetClientState *nc, int csum, int tso4, 299 int tso6, int ecn, int ufo) 300 { 301 TAPState *s = DO_UPCAST(TAPState, nc, nc); 302 if (s->fd < 0) { 303 return; 304 } 305 306 tap_fd_set_offload(s->fd, csum, tso4, tso6, ecn, ufo); 307 } 308 309 static void tap_exit_notify(Notifier *notifier, void *data) 310 { 311 TAPState *s = container_of(notifier, TAPState, exit); 312 Error *err = NULL; 313 314 if (s->down_script[0]) { 315 launch_script(s->down_script, s->down_script_arg, s->fd, &err); 316 if (err) { 317 error_report_err(err); 318 } 319 } 320 } 321 322 static void tap_cleanup(NetClientState *nc) 323 { 324 TAPState *s = DO_UPCAST(TAPState, nc, nc); 325 326 if (s->vhost_net) { 327 vhost_net_cleanup(s->vhost_net); 328 g_free(s->vhost_net); 329 s->vhost_net = NULL; 330 } 331 332 qemu_purge_queued_packets(nc); 333 334 tap_exit_notify(&s->exit, NULL); 335 qemu_remove_exit_notifier(&s->exit); 336 337 tap_read_poll(s, false); 338 tap_write_poll(s, false); 339 close(s->fd); 340 s->fd = -1; 341 } 342 343 static void tap_poll(NetClientState *nc, bool enable) 344 { 345 TAPState *s = DO_UPCAST(TAPState, nc, nc); 346 tap_read_poll(s, enable); 347 tap_write_poll(s, enable); 348 } 349 350 static bool tap_set_steering_ebpf(NetClientState *nc, int prog_fd) 351 { 352 TAPState *s = DO_UPCAST(TAPState, nc, nc); 353 assert(nc->info->type == NET_CLIENT_DRIVER_TAP); 354 355 return tap_fd_set_steering_ebpf(s->fd, prog_fd) == 0; 356 } 357 358 int tap_get_fd(NetClientState *nc) 359 { 360 TAPState *s = DO_UPCAST(TAPState, nc, nc); 361 assert(nc->info->type == NET_CLIENT_DRIVER_TAP); 362 return s->fd; 363 } 364 365 /* fd support */ 366 367 static NetClientInfo net_tap_info = { 368 .type = NET_CLIENT_DRIVER_TAP, 369 .size = sizeof(TAPState), 370 .receive = tap_receive, 371 .receive_raw = tap_receive_raw, 372 .receive_iov = tap_receive_iov, 373 .poll = tap_poll, 374 .cleanup = tap_cleanup, 375 .has_ufo = tap_has_ufo, 376 .has_vnet_hdr = tap_has_vnet_hdr, 377 .has_vnet_hdr_len = tap_has_vnet_hdr_len, 378 .using_vnet_hdr = tap_using_vnet_hdr, 379 .set_offload = tap_set_offload, 380 .set_vnet_hdr_len = tap_set_vnet_hdr_len, 381 .set_vnet_le = tap_set_vnet_le, 382 .set_vnet_be = tap_set_vnet_be, 383 .set_steering_ebpf = tap_set_steering_ebpf, 384 }; 385 386 static TAPState *net_tap_fd_init(NetClientState *peer, 387 const char *model, 388 const char *name, 389 int fd, 390 int vnet_hdr) 391 { 392 NetClientState *nc; 393 TAPState *s; 394 395 nc = qemu_new_net_client(&net_tap_info, peer, model, name); 396 397 s = DO_UPCAST(TAPState, nc, nc); 398 399 s->fd = fd; 400 s->host_vnet_hdr_len = vnet_hdr ? sizeof(struct virtio_net_hdr) : 0; 401 s->using_vnet_hdr = false; 402 s->has_ufo = tap_probe_has_ufo(s->fd); 403 s->enabled = true; 404 tap_set_offload(&s->nc, 0, 0, 0, 0, 0); 405 /* 406 * Make sure host header length is set correctly in tap: 407 * it might have been modified by another instance of qemu. 408 */ 409 if (tap_probe_vnet_hdr_len(s->fd, s->host_vnet_hdr_len)) { 410 tap_fd_set_vnet_hdr_len(s->fd, s->host_vnet_hdr_len); 411 } 412 tap_read_poll(s, true); 413 s->vhost_net = NULL; 414 415 s->exit.notify = tap_exit_notify; 416 qemu_add_exit_notifier(&s->exit); 417 418 return s; 419 } 420 421 static void launch_script(const char *setup_script, const char *ifname, 422 int fd, Error **errp) 423 { 424 int pid, status; 425 char *args[3]; 426 char **parg; 427 428 /* try to launch network script */ 429 pid = fork(); 430 if (pid < 0) { 431 error_setg_errno(errp, errno, "could not launch network script %s", 432 setup_script); 433 return; 434 } 435 if (pid == 0) { 436 int open_max = sysconf(_SC_OPEN_MAX), i; 437 438 for (i = 3; i < open_max; i++) { 439 if (i != fd) { 440 close(i); 441 } 442 } 443 parg = args; 444 *parg++ = (char *)setup_script; 445 *parg++ = (char *)ifname; 446 *parg = NULL; 447 execv(setup_script, args); 448 _exit(1); 449 } else { 450 while (waitpid(pid, &status, 0) != pid) { 451 /* loop */ 452 } 453 454 if (WIFEXITED(status) && WEXITSTATUS(status) == 0) { 455 return; 456 } 457 error_setg(errp, "network script %s failed with status %d", 458 setup_script, status); 459 } 460 } 461 462 static int recv_fd(int c) 463 { 464 int fd; 465 uint8_t msgbuf[CMSG_SPACE(sizeof(fd))]; 466 struct msghdr msg = { 467 .msg_control = msgbuf, 468 .msg_controllen = sizeof(msgbuf), 469 }; 470 struct cmsghdr *cmsg; 471 struct iovec iov; 472 uint8_t req[1]; 473 ssize_t len; 474 475 cmsg = CMSG_FIRSTHDR(&msg); 476 cmsg->cmsg_level = SOL_SOCKET; 477 cmsg->cmsg_type = SCM_RIGHTS; 478 cmsg->cmsg_len = CMSG_LEN(sizeof(fd)); 479 msg.msg_controllen = cmsg->cmsg_len; 480 481 iov.iov_base = req; 482 iov.iov_len = sizeof(req); 483 484 msg.msg_iov = &iov; 485 msg.msg_iovlen = 1; 486 487 len = recvmsg(c, &msg, 0); 488 if (len > 0) { 489 memcpy(&fd, CMSG_DATA(cmsg), sizeof(fd)); 490 return fd; 491 } 492 493 return len; 494 } 495 496 static int net_bridge_run_helper(const char *helper, const char *bridge, 497 Error **errp) 498 { 499 sigset_t oldmask, mask; 500 g_autofree char *default_helper = NULL; 501 int pid, status; 502 char *args[5]; 503 char **parg; 504 int sv[2]; 505 506 sigemptyset(&mask); 507 sigaddset(&mask, SIGCHLD); 508 sigprocmask(SIG_BLOCK, &mask, &oldmask); 509 510 if (!helper) { 511 helper = default_helper = get_relocated_path(DEFAULT_BRIDGE_HELPER); 512 } 513 514 if (socketpair(PF_UNIX, SOCK_STREAM, 0, sv) == -1) { 515 error_setg_errno(errp, errno, "socketpair() failed"); 516 return -1; 517 } 518 519 /* try to launch bridge helper */ 520 pid = fork(); 521 if (pid < 0) { 522 error_setg_errno(errp, errno, "Can't fork bridge helper"); 523 return -1; 524 } 525 if (pid == 0) { 526 int open_max = sysconf(_SC_OPEN_MAX), i; 527 char *fd_buf = NULL; 528 char *br_buf = NULL; 529 char *helper_cmd = NULL; 530 531 for (i = 3; i < open_max; i++) { 532 if (i != sv[1]) { 533 close(i); 534 } 535 } 536 537 fd_buf = g_strdup_printf("%s%d", "--fd=", sv[1]); 538 539 if (strrchr(helper, ' ') || strrchr(helper, '\t')) { 540 /* assume helper is a command */ 541 542 if (strstr(helper, "--br=") == NULL) { 543 br_buf = g_strdup_printf("%s%s", "--br=", bridge); 544 } 545 546 helper_cmd = g_strdup_printf("%s %s %s %s", helper, 547 "--use-vnet", fd_buf, br_buf ? br_buf : ""); 548 549 parg = args; 550 *parg++ = (char *)"sh"; 551 *parg++ = (char *)"-c"; 552 *parg++ = helper_cmd; 553 *parg++ = NULL; 554 555 execv("/bin/sh", args); 556 g_free(helper_cmd); 557 } else { 558 /* assume helper is just the executable path name */ 559 560 br_buf = g_strdup_printf("%s%s", "--br=", bridge); 561 562 parg = args; 563 *parg++ = (char *)helper; 564 *parg++ = (char *)"--use-vnet"; 565 *parg++ = fd_buf; 566 *parg++ = br_buf; 567 *parg++ = NULL; 568 569 execv(helper, args); 570 } 571 g_free(fd_buf); 572 g_free(br_buf); 573 _exit(1); 574 575 } else { 576 int fd; 577 int saved_errno; 578 579 close(sv[1]); 580 581 do { 582 fd = recv_fd(sv[0]); 583 } while (fd == -1 && errno == EINTR); 584 saved_errno = errno; 585 586 close(sv[0]); 587 588 while (waitpid(pid, &status, 0) != pid) { 589 /* loop */ 590 } 591 sigprocmask(SIG_SETMASK, &oldmask, NULL); 592 if (fd < 0) { 593 error_setg_errno(errp, saved_errno, 594 "failed to recv file descriptor"); 595 return -1; 596 } 597 if (!WIFEXITED(status) || WEXITSTATUS(status) != 0) { 598 error_setg(errp, "bridge helper failed"); 599 return -1; 600 } 601 return fd; 602 } 603 } 604 605 int net_init_bridge(const Netdev *netdev, const char *name, 606 NetClientState *peer, Error **errp) 607 { 608 const NetdevBridgeOptions *bridge; 609 const char *helper, *br; 610 TAPState *s; 611 int fd, vnet_hdr; 612 613 assert(netdev->type == NET_CLIENT_DRIVER_BRIDGE); 614 bridge = &netdev->u.bridge; 615 helper = bridge->has_helper ? bridge->helper : NULL; 616 br = bridge->has_br ? bridge->br : DEFAULT_BRIDGE_INTERFACE; 617 618 fd = net_bridge_run_helper(helper, br, errp); 619 if (fd == -1) { 620 return -1; 621 } 622 623 qemu_set_nonblock(fd); 624 vnet_hdr = tap_probe_vnet_hdr(fd, errp); 625 if (vnet_hdr < 0) { 626 close(fd); 627 return -1; 628 } 629 s = net_tap_fd_init(peer, "bridge", name, fd, vnet_hdr); 630 631 snprintf(s->nc.info_str, sizeof(s->nc.info_str), "helper=%s,br=%s", helper, 632 br); 633 634 return 0; 635 } 636 637 static int net_tap_init(const NetdevTapOptions *tap, int *vnet_hdr, 638 const char *setup_script, char *ifname, 639 size_t ifname_sz, int mq_required, Error **errp) 640 { 641 Error *err = NULL; 642 int fd, vnet_hdr_required; 643 644 if (tap->has_vnet_hdr) { 645 *vnet_hdr = tap->vnet_hdr; 646 vnet_hdr_required = *vnet_hdr; 647 } else { 648 *vnet_hdr = 1; 649 vnet_hdr_required = 0; 650 } 651 652 TFR(fd = tap_open(ifname, ifname_sz, vnet_hdr, vnet_hdr_required, 653 mq_required, errp)); 654 if (fd < 0) { 655 return -1; 656 } 657 658 if (setup_script && 659 setup_script[0] != '\0' && 660 strcmp(setup_script, "no") != 0) { 661 launch_script(setup_script, ifname, fd, &err); 662 if (err) { 663 error_propagate(errp, err); 664 close(fd); 665 return -1; 666 } 667 } 668 669 return fd; 670 } 671 672 #define MAX_TAP_QUEUES 1024 673 674 static void net_init_tap_one(const NetdevTapOptions *tap, NetClientState *peer, 675 const char *model, const char *name, 676 const char *ifname, const char *script, 677 const char *downscript, const char *vhostfdname, 678 int vnet_hdr, int fd, Error **errp) 679 { 680 Error *err = NULL; 681 TAPState *s = net_tap_fd_init(peer, model, name, fd, vnet_hdr); 682 int vhostfd; 683 684 tap_set_sndbuf(s->fd, tap, &err); 685 if (err) { 686 error_propagate(errp, err); 687 return; 688 } 689 690 if (tap->has_fd || tap->has_fds) { 691 snprintf(s->nc.info_str, sizeof(s->nc.info_str), "fd=%d", fd); 692 } else if (tap->has_helper) { 693 snprintf(s->nc.info_str, sizeof(s->nc.info_str), "helper=%s", 694 tap->helper); 695 } else { 696 snprintf(s->nc.info_str, sizeof(s->nc.info_str), 697 "ifname=%s,script=%s,downscript=%s", ifname, script, 698 downscript); 699 700 if (strcmp(downscript, "no") != 0) { 701 snprintf(s->down_script, sizeof(s->down_script), "%s", downscript); 702 snprintf(s->down_script_arg, sizeof(s->down_script_arg), 703 "%s", ifname); 704 } 705 } 706 707 if (tap->has_vhost ? tap->vhost : 708 vhostfdname || (tap->has_vhostforce && tap->vhostforce)) { 709 VhostNetOptions options; 710 711 options.backend_type = VHOST_BACKEND_TYPE_KERNEL; 712 options.net_backend = &s->nc; 713 if (tap->has_poll_us) { 714 options.busyloop_timeout = tap->poll_us; 715 } else { 716 options.busyloop_timeout = 0; 717 } 718 719 if (vhostfdname) { 720 int ret; 721 722 vhostfd = monitor_fd_param(monitor_cur(), vhostfdname, &err); 723 if (vhostfd == -1) { 724 if (tap->has_vhostforce && tap->vhostforce) { 725 error_propagate(errp, err); 726 } else { 727 warn_report_err(err); 728 } 729 return; 730 } 731 ret = qemu_try_set_nonblock(vhostfd); 732 if (ret < 0) { 733 error_setg_errno(errp, -ret, "%s: Can't use file descriptor %d", 734 name, fd); 735 return; 736 } 737 } else { 738 vhostfd = open("/dev/vhost-net", O_RDWR); 739 if (vhostfd < 0) { 740 if (tap->has_vhostforce && tap->vhostforce) { 741 error_setg_errno(errp, errno, 742 "tap: open vhost char device failed"); 743 } else { 744 warn_report("tap: open vhost char device failed: %s", 745 strerror(errno)); 746 } 747 return; 748 } 749 qemu_set_nonblock(vhostfd); 750 } 751 options.opaque = (void *)(uintptr_t)vhostfd; 752 options.nvqs = 2; 753 754 s->vhost_net = vhost_net_init(&options); 755 if (!s->vhost_net) { 756 if (tap->has_vhostforce && tap->vhostforce) { 757 error_setg(errp, VHOST_NET_INIT_FAILED); 758 } else { 759 warn_report(VHOST_NET_INIT_FAILED); 760 } 761 return; 762 } 763 } else if (vhostfdname) { 764 error_setg(errp, "vhostfd(s)= is not valid without vhost"); 765 } 766 } 767 768 static int get_fds(char *str, char *fds[], int max) 769 { 770 char *ptr = str, *this; 771 size_t len = strlen(str); 772 int i = 0; 773 774 while (i < max && ptr < str + len) { 775 this = strchr(ptr, ':'); 776 777 if (this == NULL) { 778 fds[i] = g_strdup(ptr); 779 } else { 780 fds[i] = g_strndup(ptr, this - ptr); 781 } 782 783 i++; 784 if (this == NULL) { 785 break; 786 } else { 787 ptr = this + 1; 788 } 789 } 790 791 return i; 792 } 793 794 int net_init_tap(const Netdev *netdev, const char *name, 795 NetClientState *peer, Error **errp) 796 { 797 const NetdevTapOptions *tap; 798 int fd, vnet_hdr = 0, i = 0, queues; 799 /* for the no-fd, no-helper case */ 800 const char *script; 801 const char *downscript; 802 Error *err = NULL; 803 const char *vhostfdname; 804 char ifname[128]; 805 int ret = 0; 806 807 assert(netdev->type == NET_CLIENT_DRIVER_TAP); 808 tap = &netdev->u.tap; 809 queues = tap->has_queues ? tap->queues : 1; 810 vhostfdname = tap->has_vhostfd ? tap->vhostfd : NULL; 811 script = tap->has_script ? tap->script : NULL; 812 downscript = tap->has_downscript ? tap->downscript : NULL; 813 814 /* QEMU hubs do not support multiqueue tap, in this case peer is set. 815 * For -netdev, peer is always NULL. */ 816 if (peer && (tap->has_queues || tap->has_fds || tap->has_vhostfds)) { 817 error_setg(errp, "Multiqueue tap cannot be used with hubs"); 818 return -1; 819 } 820 821 if (tap->has_fd) { 822 if (tap->has_ifname || tap->has_script || tap->has_downscript || 823 tap->has_vnet_hdr || tap->has_helper || tap->has_queues || 824 tap->has_fds || tap->has_vhostfds) { 825 error_setg(errp, "ifname=, script=, downscript=, vnet_hdr=, " 826 "helper=, queues=, fds=, and vhostfds= " 827 "are invalid with fd="); 828 return -1; 829 } 830 831 fd = monitor_fd_param(monitor_cur(), tap->fd, errp); 832 if (fd == -1) { 833 return -1; 834 } 835 836 ret = qemu_try_set_nonblock(fd); 837 if (ret < 0) { 838 error_setg_errno(errp, -ret, "%s: Can't use file descriptor %d", 839 name, fd); 840 close(fd); 841 return -1; 842 } 843 844 vnet_hdr = tap_probe_vnet_hdr(fd, errp); 845 if (vnet_hdr < 0) { 846 close(fd); 847 return -1; 848 } 849 850 net_init_tap_one(tap, peer, "tap", name, NULL, 851 script, downscript, 852 vhostfdname, vnet_hdr, fd, &err); 853 if (err) { 854 error_propagate(errp, err); 855 close(fd); 856 return -1; 857 } 858 } else if (tap->has_fds) { 859 char **fds; 860 char **vhost_fds; 861 int nfds = 0, nvhosts = 0; 862 863 if (tap->has_ifname || tap->has_script || tap->has_downscript || 864 tap->has_vnet_hdr || tap->has_helper || tap->has_queues || 865 tap->has_vhostfd) { 866 error_setg(errp, "ifname=, script=, downscript=, vnet_hdr=, " 867 "helper=, queues=, and vhostfd= " 868 "are invalid with fds="); 869 return -1; 870 } 871 872 fds = g_new0(char *, MAX_TAP_QUEUES); 873 vhost_fds = g_new0(char *, MAX_TAP_QUEUES); 874 875 nfds = get_fds(tap->fds, fds, MAX_TAP_QUEUES); 876 if (tap->has_vhostfds) { 877 nvhosts = get_fds(tap->vhostfds, vhost_fds, MAX_TAP_QUEUES); 878 if (nfds != nvhosts) { 879 error_setg(errp, "The number of fds passed does not match " 880 "the number of vhostfds passed"); 881 ret = -1; 882 goto free_fail; 883 } 884 } 885 886 for (i = 0; i < nfds; i++) { 887 fd = monitor_fd_param(monitor_cur(), fds[i], errp); 888 if (fd == -1) { 889 ret = -1; 890 goto free_fail; 891 } 892 893 ret = qemu_try_set_nonblock(fd); 894 if (ret < 0) { 895 error_setg_errno(errp, -ret, "%s: Can't use file descriptor %d", 896 name, fd); 897 goto free_fail; 898 } 899 900 if (i == 0) { 901 vnet_hdr = tap_probe_vnet_hdr(fd, errp); 902 if (vnet_hdr < 0) { 903 ret = -1; 904 goto free_fail; 905 } 906 } else if (vnet_hdr != tap_probe_vnet_hdr(fd, NULL)) { 907 error_setg(errp, 908 "vnet_hdr not consistent across given tap fds"); 909 ret = -1; 910 goto free_fail; 911 } 912 913 net_init_tap_one(tap, peer, "tap", name, ifname, 914 script, downscript, 915 tap->has_vhostfds ? vhost_fds[i] : NULL, 916 vnet_hdr, fd, &err); 917 if (err) { 918 error_propagate(errp, err); 919 ret = -1; 920 goto free_fail; 921 } 922 } 923 924 free_fail: 925 for (i = 0; i < nvhosts; i++) { 926 g_free(vhost_fds[i]); 927 } 928 for (i = 0; i < nfds; i++) { 929 g_free(fds[i]); 930 } 931 g_free(fds); 932 g_free(vhost_fds); 933 return ret; 934 } else if (tap->has_helper) { 935 if (tap->has_ifname || tap->has_script || tap->has_downscript || 936 tap->has_vnet_hdr || tap->has_queues || tap->has_vhostfds) { 937 error_setg(errp, "ifname=, script=, downscript=, vnet_hdr=, " 938 "queues=, and vhostfds= are invalid with helper="); 939 return -1; 940 } 941 942 fd = net_bridge_run_helper(tap->helper, 943 tap->has_br ? 944 tap->br : DEFAULT_BRIDGE_INTERFACE, 945 errp); 946 if (fd == -1) { 947 return -1; 948 } 949 950 qemu_set_nonblock(fd); 951 vnet_hdr = tap_probe_vnet_hdr(fd, errp); 952 if (vnet_hdr < 0) { 953 close(fd); 954 return -1; 955 } 956 957 net_init_tap_one(tap, peer, "bridge", name, ifname, 958 script, downscript, vhostfdname, 959 vnet_hdr, fd, &err); 960 if (err) { 961 error_propagate(errp, err); 962 close(fd); 963 return -1; 964 } 965 } else { 966 g_autofree char *default_script = NULL; 967 g_autofree char *default_downscript = NULL; 968 if (tap->has_vhostfds) { 969 error_setg(errp, "vhostfds= is invalid if fds= wasn't specified"); 970 return -1; 971 } 972 973 if (!script) { 974 script = default_script = get_relocated_path(DEFAULT_NETWORK_SCRIPT); 975 } 976 if (!downscript) { 977 downscript = default_downscript = 978 get_relocated_path(DEFAULT_NETWORK_DOWN_SCRIPT); 979 } 980 981 if (tap->has_ifname) { 982 pstrcpy(ifname, sizeof ifname, tap->ifname); 983 } else { 984 ifname[0] = '\0'; 985 } 986 987 for (i = 0; i < queues; i++) { 988 fd = net_tap_init(tap, &vnet_hdr, i >= 1 ? "no" : script, 989 ifname, sizeof ifname, queues > 1, errp); 990 if (fd == -1) { 991 return -1; 992 } 993 994 if (queues > 1 && i == 0 && !tap->has_ifname) { 995 if (tap_fd_get_ifname(fd, ifname)) { 996 error_setg(errp, "Fail to get ifname"); 997 close(fd); 998 return -1; 999 } 1000 } 1001 1002 net_init_tap_one(tap, peer, "tap", name, ifname, 1003 i >= 1 ? "no" : script, 1004 i >= 1 ? "no" : downscript, 1005 vhostfdname, vnet_hdr, fd, &err); 1006 if (err) { 1007 error_propagate(errp, err); 1008 close(fd); 1009 return -1; 1010 } 1011 } 1012 } 1013 1014 return 0; 1015 } 1016 1017 VHostNetState *tap_get_vhost_net(NetClientState *nc) 1018 { 1019 TAPState *s = DO_UPCAST(TAPState, nc, nc); 1020 assert(nc->info->type == NET_CLIENT_DRIVER_TAP); 1021 return s->vhost_net; 1022 } 1023 1024 int tap_enable(NetClientState *nc) 1025 { 1026 TAPState *s = DO_UPCAST(TAPState, nc, nc); 1027 int ret; 1028 1029 if (s->enabled) { 1030 return 0; 1031 } else { 1032 ret = tap_fd_enable(s->fd); 1033 if (ret == 0) { 1034 s->enabled = true; 1035 tap_update_fd_handler(s); 1036 } 1037 return ret; 1038 } 1039 } 1040 1041 int tap_disable(NetClientState *nc) 1042 { 1043 TAPState *s = DO_UPCAST(TAPState, nc, nc); 1044 int ret; 1045 1046 if (s->enabled == 0) { 1047 return 0; 1048 } else { 1049 ret = tap_fd_disable(s->fd); 1050 if (ret == 0) { 1051 qemu_purge_queued_packets(nc); 1052 s->enabled = false; 1053 tap_update_fd_handler(s); 1054 } 1055 return ret; 1056 } 1057 } 1058