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