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/net.h" 36 #include "clients.h" 37 #include "monitor/monitor.h" 38 #include "sysemu/sysemu.h" 39 #include "qapi/error.h" 40 #include "qemu-common.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 enabled; 61 VHostNetState *vhost_net; 62 unsigned host_vnet_hdr_len; 63 Notifier exit; 64 } TAPState; 65 66 static void launch_script(const char *setup_script, const char *ifname, 67 int fd, Error **errp); 68 69 static void tap_send(void *opaque); 70 static void tap_writable(void *opaque); 71 72 static void tap_update_fd_handler(TAPState *s) 73 { 74 qemu_set_fd_handler(s->fd, 75 s->read_poll && s->enabled ? tap_send : NULL, 76 s->write_poll && s->enabled ? tap_writable : NULL, 77 s); 78 } 79 80 static void tap_read_poll(TAPState *s, bool enable) 81 { 82 s->read_poll = enable; 83 tap_update_fd_handler(s); 84 } 85 86 static void tap_write_poll(TAPState *s, bool enable) 87 { 88 s->write_poll = enable; 89 tap_update_fd_handler(s); 90 } 91 92 static void tap_writable(void *opaque) 93 { 94 TAPState *s = opaque; 95 96 tap_write_poll(s, false); 97 98 qemu_flush_queued_packets(&s->nc); 99 } 100 101 static ssize_t tap_write_packet(TAPState *s, const struct iovec *iov, int iovcnt) 102 { 103 ssize_t len; 104 105 do { 106 len = writev(s->fd, iov, iovcnt); 107 } while (len == -1 && errno == EINTR); 108 109 if (len == -1 && errno == EAGAIN) { 110 tap_write_poll(s, true); 111 return 0; 112 } 113 114 return len; 115 } 116 117 static ssize_t tap_receive_iov(NetClientState *nc, const struct iovec *iov, 118 int iovcnt) 119 { 120 TAPState *s = DO_UPCAST(TAPState, nc, nc); 121 const struct iovec *iovp = iov; 122 struct iovec iov_copy[iovcnt + 1]; 123 struct virtio_net_hdr_mrg_rxbuf hdr = { }; 124 125 if (s->host_vnet_hdr_len && !s->using_vnet_hdr) { 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; 192 193 size = tap_read_packet(s->fd, s->buf, sizeof(s->buf)); 194 if (size <= 0) { 195 break; 196 } 197 198 if (s->host_vnet_hdr_len && !s->using_vnet_hdr) { 199 buf += s->host_vnet_hdr_len; 200 size -= s->host_vnet_hdr_len; 201 } 202 203 size = qemu_send_packet_async(&s->nc, buf, size, tap_send_completed); 204 if (size == 0) { 205 tap_read_poll(s, false); 206 break; 207 } else if (size < 0) { 208 break; 209 } 210 211 /* 212 * When the host keeps receiving more packets while tap_send() is 213 * running we can hog the QEMU global mutex. Limit the number of 214 * packets that are processed per tap_send() callback to prevent 215 * stalling the guest. 216 */ 217 packets++; 218 if (packets >= 50) { 219 break; 220 } 221 } 222 } 223 224 static bool tap_has_ufo(NetClientState *nc) 225 { 226 TAPState *s = DO_UPCAST(TAPState, nc, nc); 227 228 assert(nc->info->type == NET_CLIENT_DRIVER_TAP); 229 230 return s->has_ufo; 231 } 232 233 static bool tap_has_vnet_hdr(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->host_vnet_hdr_len; 240 } 241 242 static bool tap_has_vnet_hdr_len(NetClientState *nc, int len) 243 { 244 TAPState *s = DO_UPCAST(TAPState, nc, nc); 245 246 assert(nc->info->type == NET_CLIENT_DRIVER_TAP); 247 248 return !!tap_probe_vnet_hdr_len(s->fd, len); 249 } 250 251 static void tap_set_vnet_hdr_len(NetClientState *nc, int len) 252 { 253 TAPState *s = DO_UPCAST(TAPState, nc, nc); 254 255 assert(nc->info->type == NET_CLIENT_DRIVER_TAP); 256 assert(len == sizeof(struct virtio_net_hdr_mrg_rxbuf) || 257 len == sizeof(struct virtio_net_hdr) || 258 len == sizeof(struct virtio_net_hdr_v1_hash)); 259 260 tap_fd_set_vnet_hdr_len(s->fd, len); 261 s->host_vnet_hdr_len = len; 262 } 263 264 static void tap_using_vnet_hdr(NetClientState *nc, bool using_vnet_hdr) 265 { 266 TAPState *s = DO_UPCAST(TAPState, nc, nc); 267 268 assert(nc->info->type == NET_CLIENT_DRIVER_TAP); 269 assert(!!s->host_vnet_hdr_len == using_vnet_hdr); 270 271 s->using_vnet_hdr = using_vnet_hdr; 272 } 273 274 static int tap_set_vnet_le(NetClientState *nc, bool is_le) 275 { 276 TAPState *s = DO_UPCAST(TAPState, nc, nc); 277 278 return tap_fd_set_vnet_le(s->fd, is_le); 279 } 280 281 static int tap_set_vnet_be(NetClientState *nc, bool is_be) 282 { 283 TAPState *s = DO_UPCAST(TAPState, nc, nc); 284 285 return tap_fd_set_vnet_be(s->fd, is_be); 286 } 287 288 static void tap_set_offload(NetClientState *nc, int csum, int tso4, 289 int tso6, int ecn, int ufo) 290 { 291 TAPState *s = DO_UPCAST(TAPState, nc, nc); 292 if (s->fd < 0) { 293 return; 294 } 295 296 tap_fd_set_offload(s->fd, csum, tso4, tso6, ecn, ufo); 297 } 298 299 static void tap_exit_notify(Notifier *notifier, void *data) 300 { 301 TAPState *s = container_of(notifier, TAPState, exit); 302 Error *err = NULL; 303 304 if (s->down_script[0]) { 305 launch_script(s->down_script, s->down_script_arg, s->fd, &err); 306 if (err) { 307 error_report_err(err); 308 } 309 } 310 } 311 312 static void tap_cleanup(NetClientState *nc) 313 { 314 TAPState *s = DO_UPCAST(TAPState, nc, nc); 315 316 if (s->vhost_net) { 317 vhost_net_cleanup(s->vhost_net); 318 g_free(s->vhost_net); 319 s->vhost_net = NULL; 320 } 321 322 qemu_purge_queued_packets(nc); 323 324 tap_exit_notify(&s->exit, NULL); 325 qemu_remove_exit_notifier(&s->exit); 326 327 tap_read_poll(s, false); 328 tap_write_poll(s, false); 329 close(s->fd); 330 s->fd = -1; 331 } 332 333 static void tap_poll(NetClientState *nc, bool enable) 334 { 335 TAPState *s = DO_UPCAST(TAPState, nc, nc); 336 tap_read_poll(s, enable); 337 tap_write_poll(s, enable); 338 } 339 340 int tap_get_fd(NetClientState *nc) 341 { 342 TAPState *s = DO_UPCAST(TAPState, nc, nc); 343 assert(nc->info->type == NET_CLIENT_DRIVER_TAP); 344 return s->fd; 345 } 346 347 /* fd support */ 348 349 static NetClientInfo net_tap_info = { 350 .type = NET_CLIENT_DRIVER_TAP, 351 .size = sizeof(TAPState), 352 .receive = tap_receive, 353 .receive_raw = tap_receive_raw, 354 .receive_iov = tap_receive_iov, 355 .poll = tap_poll, 356 .cleanup = tap_cleanup, 357 .has_ufo = tap_has_ufo, 358 .has_vnet_hdr = tap_has_vnet_hdr, 359 .has_vnet_hdr_len = tap_has_vnet_hdr_len, 360 .using_vnet_hdr = tap_using_vnet_hdr, 361 .set_offload = tap_set_offload, 362 .set_vnet_hdr_len = tap_set_vnet_hdr_len, 363 .set_vnet_le = tap_set_vnet_le, 364 .set_vnet_be = tap_set_vnet_be, 365 }; 366 367 static TAPState *net_tap_fd_init(NetClientState *peer, 368 const char *model, 369 const char *name, 370 int fd, 371 int vnet_hdr) 372 { 373 NetClientState *nc; 374 TAPState *s; 375 376 nc = qemu_new_net_client(&net_tap_info, peer, model, name); 377 378 s = DO_UPCAST(TAPState, nc, nc); 379 380 s->fd = fd; 381 s->host_vnet_hdr_len = vnet_hdr ? sizeof(struct virtio_net_hdr) : 0; 382 s->using_vnet_hdr = false; 383 s->has_ufo = tap_probe_has_ufo(s->fd); 384 s->enabled = true; 385 tap_set_offload(&s->nc, 0, 0, 0, 0, 0); 386 /* 387 * Make sure host header length is set correctly in tap: 388 * it might have been modified by another instance of qemu. 389 */ 390 if (tap_probe_vnet_hdr_len(s->fd, s->host_vnet_hdr_len)) { 391 tap_fd_set_vnet_hdr_len(s->fd, s->host_vnet_hdr_len); 392 } 393 tap_read_poll(s, true); 394 s->vhost_net = NULL; 395 396 s->exit.notify = tap_exit_notify; 397 qemu_add_exit_notifier(&s->exit); 398 399 return s; 400 } 401 402 static void launch_script(const char *setup_script, const char *ifname, 403 int fd, Error **errp) 404 { 405 int pid, status; 406 char *args[3]; 407 char **parg; 408 409 /* try to launch network script */ 410 pid = fork(); 411 if (pid < 0) { 412 error_setg_errno(errp, errno, "could not launch network script %s", 413 setup_script); 414 return; 415 } 416 if (pid == 0) { 417 int open_max = sysconf(_SC_OPEN_MAX), i; 418 419 for (i = 3; i < open_max; i++) { 420 if (i != fd) { 421 close(i); 422 } 423 } 424 parg = args; 425 *parg++ = (char *)setup_script; 426 *parg++ = (char *)ifname; 427 *parg = NULL; 428 execv(setup_script, args); 429 _exit(1); 430 } else { 431 while (waitpid(pid, &status, 0) != pid) { 432 /* loop */ 433 } 434 435 if (WIFEXITED(status) && WEXITSTATUS(status) == 0) { 436 return; 437 } 438 error_setg(errp, "network script %s failed with status %d", 439 setup_script, status); 440 } 441 } 442 443 static int recv_fd(int c) 444 { 445 int fd; 446 uint8_t msgbuf[CMSG_SPACE(sizeof(fd))]; 447 struct msghdr msg = { 448 .msg_control = msgbuf, 449 .msg_controllen = sizeof(msgbuf), 450 }; 451 struct cmsghdr *cmsg; 452 struct iovec iov; 453 uint8_t req[1]; 454 ssize_t len; 455 456 cmsg = CMSG_FIRSTHDR(&msg); 457 cmsg->cmsg_level = SOL_SOCKET; 458 cmsg->cmsg_type = SCM_RIGHTS; 459 cmsg->cmsg_len = CMSG_LEN(sizeof(fd)); 460 msg.msg_controllen = cmsg->cmsg_len; 461 462 iov.iov_base = req; 463 iov.iov_len = sizeof(req); 464 465 msg.msg_iov = &iov; 466 msg.msg_iovlen = 1; 467 468 len = recvmsg(c, &msg, 0); 469 if (len > 0) { 470 memcpy(&fd, CMSG_DATA(cmsg), sizeof(fd)); 471 return fd; 472 } 473 474 return len; 475 } 476 477 static int net_bridge_run_helper(const char *helper, const char *bridge, 478 Error **errp) 479 { 480 sigset_t oldmask, mask; 481 int pid, status; 482 char *args[5]; 483 char **parg; 484 int sv[2]; 485 486 sigemptyset(&mask); 487 sigaddset(&mask, SIGCHLD); 488 sigprocmask(SIG_BLOCK, &mask, &oldmask); 489 490 if (socketpair(PF_UNIX, SOCK_STREAM, 0, sv) == -1) { 491 error_setg_errno(errp, errno, "socketpair() failed"); 492 return -1; 493 } 494 495 /* try to launch bridge helper */ 496 pid = fork(); 497 if (pid < 0) { 498 error_setg_errno(errp, errno, "Can't fork bridge helper"); 499 return -1; 500 } 501 if (pid == 0) { 502 int open_max = sysconf(_SC_OPEN_MAX), i; 503 char *fd_buf = NULL; 504 char *br_buf = NULL; 505 char *helper_cmd = NULL; 506 507 for (i = 3; i < open_max; i++) { 508 if (i != sv[1]) { 509 close(i); 510 } 511 } 512 513 fd_buf = g_strdup_printf("%s%d", "--fd=", sv[1]); 514 515 if (strrchr(helper, ' ') || strrchr(helper, '\t')) { 516 /* assume helper is a command */ 517 518 if (strstr(helper, "--br=") == NULL) { 519 br_buf = g_strdup_printf("%s%s", "--br=", bridge); 520 } 521 522 helper_cmd = g_strdup_printf("%s %s %s %s", helper, 523 "--use-vnet", fd_buf, br_buf ? br_buf : ""); 524 525 parg = args; 526 *parg++ = (char *)"sh"; 527 *parg++ = (char *)"-c"; 528 *parg++ = helper_cmd; 529 *parg++ = NULL; 530 531 execv("/bin/sh", args); 532 g_free(helper_cmd); 533 } else { 534 /* assume helper is just the executable path name */ 535 536 br_buf = g_strdup_printf("%s%s", "--br=", bridge); 537 538 parg = args; 539 *parg++ = (char *)helper; 540 *parg++ = (char *)"--use-vnet"; 541 *parg++ = fd_buf; 542 *parg++ = br_buf; 543 *parg++ = NULL; 544 545 execv(helper, args); 546 } 547 g_free(fd_buf); 548 g_free(br_buf); 549 _exit(1); 550 551 } else { 552 int fd; 553 int saved_errno; 554 555 close(sv[1]); 556 557 do { 558 fd = recv_fd(sv[0]); 559 } while (fd == -1 && errno == EINTR); 560 saved_errno = errno; 561 562 close(sv[0]); 563 564 while (waitpid(pid, &status, 0) != pid) { 565 /* loop */ 566 } 567 sigprocmask(SIG_SETMASK, &oldmask, NULL); 568 if (fd < 0) { 569 error_setg_errno(errp, saved_errno, 570 "failed to recv file descriptor"); 571 return -1; 572 } 573 if (!WIFEXITED(status) || WEXITSTATUS(status) != 0) { 574 error_setg(errp, "bridge helper failed"); 575 return -1; 576 } 577 return fd; 578 } 579 } 580 581 int net_init_bridge(const Netdev *netdev, const char *name, 582 NetClientState *peer, Error **errp) 583 { 584 const NetdevBridgeOptions *bridge; 585 const char *helper, *br; 586 TAPState *s; 587 int fd, vnet_hdr; 588 589 assert(netdev->type == NET_CLIENT_DRIVER_BRIDGE); 590 bridge = &netdev->u.bridge; 591 592 helper = bridge->has_helper ? bridge->helper : DEFAULT_BRIDGE_HELPER; 593 br = bridge->has_br ? bridge->br : DEFAULT_BRIDGE_INTERFACE; 594 595 fd = net_bridge_run_helper(helper, br, errp); 596 if (fd == -1) { 597 return -1; 598 } 599 600 qemu_set_nonblock(fd); 601 vnet_hdr = tap_probe_vnet_hdr(fd); 602 s = net_tap_fd_init(peer, "bridge", name, fd, vnet_hdr); 603 604 snprintf(s->nc.info_str, sizeof(s->nc.info_str), "helper=%s,br=%s", helper, 605 br); 606 607 return 0; 608 } 609 610 static int net_tap_init(const NetdevTapOptions *tap, int *vnet_hdr, 611 const char *setup_script, char *ifname, 612 size_t ifname_sz, int mq_required, Error **errp) 613 { 614 Error *err = NULL; 615 int fd, vnet_hdr_required; 616 617 if (tap->has_vnet_hdr) { 618 *vnet_hdr = tap->vnet_hdr; 619 vnet_hdr_required = *vnet_hdr; 620 } else { 621 *vnet_hdr = 1; 622 vnet_hdr_required = 0; 623 } 624 625 TFR(fd = tap_open(ifname, ifname_sz, vnet_hdr, vnet_hdr_required, 626 mq_required, errp)); 627 if (fd < 0) { 628 return -1; 629 } 630 631 if (setup_script && 632 setup_script[0] != '\0' && 633 strcmp(setup_script, "no") != 0) { 634 launch_script(setup_script, ifname, fd, &err); 635 if (err) { 636 error_propagate(errp, err); 637 close(fd); 638 return -1; 639 } 640 } 641 642 return fd; 643 } 644 645 #define MAX_TAP_QUEUES 1024 646 647 static void net_init_tap_one(const NetdevTapOptions *tap, NetClientState *peer, 648 const char *model, const char *name, 649 const char *ifname, const char *script, 650 const char *downscript, const char *vhostfdname, 651 int vnet_hdr, int fd, Error **errp) 652 { 653 Error *err = NULL; 654 TAPState *s = net_tap_fd_init(peer, model, name, fd, vnet_hdr); 655 int vhostfd; 656 657 tap_set_sndbuf(s->fd, tap, &err); 658 if (err) { 659 error_propagate(errp, err); 660 return; 661 } 662 663 if (tap->has_fd || tap->has_fds) { 664 snprintf(s->nc.info_str, sizeof(s->nc.info_str), "fd=%d", fd); 665 } else if (tap->has_helper) { 666 snprintf(s->nc.info_str, sizeof(s->nc.info_str), "helper=%s", 667 tap->helper); 668 } else { 669 snprintf(s->nc.info_str, sizeof(s->nc.info_str), 670 "ifname=%s,script=%s,downscript=%s", ifname, script, 671 downscript); 672 673 if (strcmp(downscript, "no") != 0) { 674 snprintf(s->down_script, sizeof(s->down_script), "%s", downscript); 675 snprintf(s->down_script_arg, sizeof(s->down_script_arg), 676 "%s", ifname); 677 } 678 } 679 680 if (tap->has_vhost ? tap->vhost : 681 vhostfdname || (tap->has_vhostforce && tap->vhostforce)) { 682 VhostNetOptions options; 683 684 options.backend_type = VHOST_BACKEND_TYPE_KERNEL; 685 options.net_backend = &s->nc; 686 if (tap->has_poll_us) { 687 options.busyloop_timeout = tap->poll_us; 688 } else { 689 options.busyloop_timeout = 0; 690 } 691 692 if (vhostfdname) { 693 vhostfd = monitor_fd_param(cur_mon, vhostfdname, &err); 694 if (vhostfd == -1) { 695 if (tap->has_vhostforce && tap->vhostforce) { 696 error_propagate(errp, err); 697 } else { 698 warn_report_err(err); 699 } 700 return; 701 } 702 qemu_set_nonblock(vhostfd); 703 } else { 704 vhostfd = open("/dev/vhost-net", O_RDWR); 705 if (vhostfd < 0) { 706 if (tap->has_vhostforce && tap->vhostforce) { 707 error_setg_errno(errp, errno, 708 "tap: open vhost char device failed"); 709 } else { 710 warn_report("tap: open vhost char device failed: %s", 711 strerror(errno)); 712 } 713 return; 714 } 715 qemu_set_nonblock(vhostfd); 716 } 717 options.opaque = (void *)(uintptr_t)vhostfd; 718 719 s->vhost_net = vhost_net_init(&options); 720 if (!s->vhost_net) { 721 if (tap->has_vhostforce && tap->vhostforce) { 722 error_setg(errp, VHOST_NET_INIT_FAILED); 723 } else { 724 warn_report(VHOST_NET_INIT_FAILED); 725 } 726 return; 727 } 728 } else if (vhostfdname) { 729 error_setg(errp, "vhostfd(s)= is not valid without vhost"); 730 } 731 } 732 733 static int get_fds(char *str, char *fds[], int max) 734 { 735 char *ptr = str, *this; 736 size_t len = strlen(str); 737 int i = 0; 738 739 while (i < max && ptr < str + len) { 740 this = strchr(ptr, ':'); 741 742 if (this == NULL) { 743 fds[i] = g_strdup(ptr); 744 } else { 745 fds[i] = g_strndup(ptr, this - ptr); 746 } 747 748 i++; 749 if (this == NULL) { 750 break; 751 } else { 752 ptr = this + 1; 753 } 754 } 755 756 return i; 757 } 758 759 int net_init_tap(const Netdev *netdev, const char *name, 760 NetClientState *peer, Error **errp) 761 { 762 const NetdevTapOptions *tap; 763 int fd, vnet_hdr = 0, i = 0, queues; 764 /* for the no-fd, no-helper case */ 765 const char *script = NULL; /* suppress wrong "uninit'd use" gcc warning */ 766 const char *downscript = NULL; 767 Error *err = NULL; 768 const char *vhostfdname; 769 char ifname[128]; 770 771 assert(netdev->type == NET_CLIENT_DRIVER_TAP); 772 tap = &netdev->u.tap; 773 queues = tap->has_queues ? tap->queues : 1; 774 vhostfdname = tap->has_vhostfd ? tap->vhostfd : NULL; 775 776 /* QEMU hubs do not support multiqueue tap, in this case peer is set. 777 * For -netdev, peer is always NULL. */ 778 if (peer && (tap->has_queues || tap->has_fds || tap->has_vhostfds)) { 779 error_setg(errp, "Multiqueue tap cannot be used with hubs"); 780 return -1; 781 } 782 783 if (tap->has_fd) { 784 if (tap->has_ifname || tap->has_script || tap->has_downscript || 785 tap->has_vnet_hdr || tap->has_helper || tap->has_queues || 786 tap->has_fds || tap->has_vhostfds) { 787 error_setg(errp, "ifname=, script=, downscript=, vnet_hdr=, " 788 "helper=, queues=, fds=, and vhostfds= " 789 "are invalid with fd="); 790 return -1; 791 } 792 793 fd = monitor_fd_param(cur_mon, tap->fd, &err); 794 if (fd == -1) { 795 error_propagate(errp, err); 796 return -1; 797 } 798 799 qemu_set_nonblock(fd); 800 801 vnet_hdr = tap_probe_vnet_hdr(fd); 802 803 net_init_tap_one(tap, peer, "tap", name, NULL, 804 script, downscript, 805 vhostfdname, vnet_hdr, fd, &err); 806 if (err) { 807 error_propagate(errp, err); 808 return -1; 809 } 810 } else if (tap->has_fds) { 811 char **fds; 812 char **vhost_fds; 813 int nfds = 0, nvhosts = 0; 814 int ret = 0; 815 816 if (tap->has_ifname || tap->has_script || tap->has_downscript || 817 tap->has_vnet_hdr || tap->has_helper || tap->has_queues || 818 tap->has_vhostfd) { 819 error_setg(errp, "ifname=, script=, downscript=, vnet_hdr=, " 820 "helper=, queues=, and vhostfd= " 821 "are invalid with fds="); 822 return -1; 823 } 824 825 fds = g_new0(char *, MAX_TAP_QUEUES); 826 vhost_fds = g_new0(char *, MAX_TAP_QUEUES); 827 828 nfds = get_fds(tap->fds, fds, MAX_TAP_QUEUES); 829 if (tap->has_vhostfds) { 830 nvhosts = get_fds(tap->vhostfds, vhost_fds, MAX_TAP_QUEUES); 831 if (nfds != nvhosts) { 832 error_setg(errp, "The number of fds passed does not match " 833 "the number of vhostfds passed"); 834 ret = -1; 835 goto free_fail; 836 } 837 } 838 839 for (i = 0; i < nfds; i++) { 840 fd = monitor_fd_param(cur_mon, fds[i], &err); 841 if (fd == -1) { 842 error_propagate(errp, err); 843 ret = -1; 844 goto free_fail; 845 } 846 847 qemu_set_nonblock(fd); 848 849 if (i == 0) { 850 vnet_hdr = tap_probe_vnet_hdr(fd); 851 } else if (vnet_hdr != tap_probe_vnet_hdr(fd)) { 852 error_setg(errp, 853 "vnet_hdr not consistent across given tap fds"); 854 ret = -1; 855 goto free_fail; 856 } 857 858 net_init_tap_one(tap, peer, "tap", name, ifname, 859 script, downscript, 860 tap->has_vhostfds ? vhost_fds[i] : NULL, 861 vnet_hdr, fd, &err); 862 if (err) { 863 error_propagate(errp, err); 864 ret = -1; 865 goto free_fail; 866 } 867 } 868 869 free_fail: 870 for (i = 0; i < nvhosts; i++) { 871 g_free(vhost_fds[i]); 872 } 873 for (i = 0; i < nfds; i++) { 874 g_free(fds[i]); 875 } 876 g_free(fds); 877 g_free(vhost_fds); 878 return ret; 879 } else if (tap->has_helper) { 880 if (tap->has_ifname || tap->has_script || tap->has_downscript || 881 tap->has_vnet_hdr || tap->has_queues || tap->has_vhostfds) { 882 error_setg(errp, "ifname=, script=, downscript=, vnet_hdr=, " 883 "queues=, and vhostfds= are invalid with helper="); 884 return -1; 885 } 886 887 fd = net_bridge_run_helper(tap->helper, 888 tap->has_br ? 889 tap->br : DEFAULT_BRIDGE_INTERFACE, 890 errp); 891 if (fd == -1) { 892 return -1; 893 } 894 895 qemu_set_nonblock(fd); 896 vnet_hdr = tap_probe_vnet_hdr(fd); 897 898 net_init_tap_one(tap, peer, "bridge", name, ifname, 899 script, downscript, vhostfdname, 900 vnet_hdr, fd, &err); 901 if (err) { 902 error_propagate(errp, err); 903 close(fd); 904 return -1; 905 } 906 } else { 907 if (tap->has_vhostfds) { 908 error_setg(errp, "vhostfds= is invalid if fds= wasn't specified"); 909 return -1; 910 } 911 script = tap->has_script ? tap->script : DEFAULT_NETWORK_SCRIPT; 912 downscript = tap->has_downscript ? tap->downscript : 913 DEFAULT_NETWORK_DOWN_SCRIPT; 914 915 if (tap->has_ifname) { 916 pstrcpy(ifname, sizeof ifname, tap->ifname); 917 } else { 918 ifname[0] = '\0'; 919 } 920 921 for (i = 0; i < queues; i++) { 922 fd = net_tap_init(tap, &vnet_hdr, i >= 1 ? "no" : script, 923 ifname, sizeof ifname, queues > 1, errp); 924 if (fd == -1) { 925 return -1; 926 } 927 928 if (queues > 1 && i == 0 && !tap->has_ifname) { 929 if (tap_fd_get_ifname(fd, ifname)) { 930 error_setg(errp, "Fail to get ifname"); 931 close(fd); 932 return -1; 933 } 934 } 935 936 net_init_tap_one(tap, peer, "tap", name, ifname, 937 i >= 1 ? "no" : script, 938 i >= 1 ? "no" : downscript, 939 vhostfdname, vnet_hdr, fd, &err); 940 if (err) { 941 error_propagate(errp, err); 942 close(fd); 943 return -1; 944 } 945 } 946 } 947 948 return 0; 949 } 950 951 VHostNetState *tap_get_vhost_net(NetClientState *nc) 952 { 953 TAPState *s = DO_UPCAST(TAPState, nc, nc); 954 assert(nc->info->type == NET_CLIENT_DRIVER_TAP); 955 return s->vhost_net; 956 } 957 958 int tap_enable(NetClientState *nc) 959 { 960 TAPState *s = DO_UPCAST(TAPState, nc, nc); 961 int ret; 962 963 if (s->enabled) { 964 return 0; 965 } else { 966 ret = tap_fd_enable(s->fd); 967 if (ret == 0) { 968 s->enabled = true; 969 tap_update_fd_handler(s); 970 } 971 return ret; 972 } 973 } 974 975 int tap_disable(NetClientState *nc) 976 { 977 TAPState *s = DO_UPCAST(TAPState, nc, nc); 978 int ret; 979 980 if (s->enabled == 0) { 981 return 0; 982 } else { 983 ret = tap_fd_disable(s->fd); 984 if (ret == 0) { 985 qemu_purge_queued_packets(nc); 986 s->enabled = false; 987 tap_update_fd_handler(s); 988 } 989 return ret; 990 } 991 } 992