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/sockets.h" 44 45 #include "net/tap.h" 46 47 #include "net/vhost_net.h" 48 49 typedef struct TAPState { 50 NetClientState nc; 51 int fd; 52 char down_script[1024]; 53 char down_script_arg[128]; 54 uint8_t buf[NET_BUFSIZE]; 55 bool read_poll; 56 bool write_poll; 57 bool using_vnet_hdr; 58 bool has_ufo; 59 bool enabled; 60 VHostNetState *vhost_net; 61 unsigned host_vnet_hdr_len; 62 Notifier exit; 63 } TAPState; 64 65 static void launch_script(const char *setup_script, const char *ifname, 66 int fd, Error **errp); 67 68 static void tap_send(void *opaque); 69 static void tap_writable(void *opaque); 70 71 static void tap_update_fd_handler(TAPState *s) 72 { 73 qemu_set_fd_handler(s->fd, 74 s->read_poll && s->enabled ? tap_send : NULL, 75 s->write_poll && s->enabled ? tap_writable : NULL, 76 s); 77 } 78 79 static void tap_read_poll(TAPState *s, bool enable) 80 { 81 s->read_poll = enable; 82 tap_update_fd_handler(s); 83 } 84 85 static void tap_write_poll(TAPState *s, bool enable) 86 { 87 s->write_poll = enable; 88 tap_update_fd_handler(s); 89 } 90 91 static void tap_writable(void *opaque) 92 { 93 TAPState *s = opaque; 94 95 tap_write_poll(s, false); 96 97 qemu_flush_queued_packets(&s->nc); 98 } 99 100 static ssize_t tap_write_packet(TAPState *s, const struct iovec *iov, int iovcnt) 101 { 102 ssize_t len; 103 104 do { 105 len = writev(s->fd, iov, iovcnt); 106 } while (len == -1 && errno == EINTR); 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 struct iovec iov_copy[iovcnt + 1]; 122 struct virtio_net_hdr_mrg_rxbuf hdr = { }; 123 124 if (s->host_vnet_hdr_len && !s->using_vnet_hdr) { 125 iov_copy[0].iov_base = &hdr; 126 iov_copy[0].iov_len = s->host_vnet_hdr_len; 127 memcpy(&iov_copy[1], iov, iovcnt * sizeof(*iov)); 128 iovp = iov_copy; 129 iovcnt++; 130 } 131 132 return tap_write_packet(s, iovp, iovcnt); 133 } 134 135 static ssize_t tap_receive_raw(NetClientState *nc, const uint8_t *buf, size_t size) 136 { 137 TAPState *s = DO_UPCAST(TAPState, nc, nc); 138 struct iovec iov[2]; 139 int iovcnt = 0; 140 struct virtio_net_hdr_mrg_rxbuf hdr = { }; 141 142 if (s->host_vnet_hdr_len) { 143 iov[iovcnt].iov_base = &hdr; 144 iov[iovcnt].iov_len = s->host_vnet_hdr_len; 145 iovcnt++; 146 } 147 148 iov[iovcnt].iov_base = (char *)buf; 149 iov[iovcnt].iov_len = size; 150 iovcnt++; 151 152 return tap_write_packet(s, iov, iovcnt); 153 } 154 155 static ssize_t tap_receive(NetClientState *nc, const uint8_t *buf, size_t size) 156 { 157 TAPState *s = DO_UPCAST(TAPState, nc, nc); 158 struct iovec iov[1]; 159 160 if (s->host_vnet_hdr_len && !s->using_vnet_hdr) { 161 return tap_receive_raw(nc, buf, size); 162 } 163 164 iov[0].iov_base = (char *)buf; 165 iov[0].iov_len = size; 166 167 return tap_write_packet(s, iov, 1); 168 } 169 170 #ifndef __sun__ 171 ssize_t tap_read_packet(int tapfd, uint8_t *buf, int maxlen) 172 { 173 return read(tapfd, buf, maxlen); 174 } 175 #endif 176 177 static void tap_send_completed(NetClientState *nc, ssize_t len) 178 { 179 TAPState *s = DO_UPCAST(TAPState, nc, nc); 180 tap_read_poll(s, true); 181 } 182 183 static void tap_send(void *opaque) 184 { 185 TAPState *s = opaque; 186 int size; 187 int packets = 0; 188 189 while (true) { 190 uint8_t *buf = s->buf; 191 192 size = tap_read_packet(s->fd, s->buf, sizeof(s->buf)); 193 if (size <= 0) { 194 break; 195 } 196 197 if (s->host_vnet_hdr_len && !s->using_vnet_hdr) { 198 buf += s->host_vnet_hdr_len; 199 size -= s->host_vnet_hdr_len; 200 } 201 202 size = qemu_send_packet_async(&s->nc, buf, size, tap_send_completed); 203 if (size == 0) { 204 tap_read_poll(s, false); 205 break; 206 } else if (size < 0) { 207 break; 208 } 209 210 /* 211 * When the host keeps receiving more packets while tap_send() is 212 * running we can hog the QEMU global mutex. Limit the number of 213 * packets that are processed per tap_send() callback to prevent 214 * stalling the guest. 215 */ 216 packets++; 217 if (packets >= 50) { 218 break; 219 } 220 } 221 } 222 223 static bool tap_has_ufo(NetClientState *nc) 224 { 225 TAPState *s = DO_UPCAST(TAPState, nc, nc); 226 227 assert(nc->info->type == NET_CLIENT_DRIVER_TAP); 228 229 return s->has_ufo; 230 } 231 232 static bool tap_has_vnet_hdr(NetClientState *nc) 233 { 234 TAPState *s = DO_UPCAST(TAPState, nc, nc); 235 236 assert(nc->info->type == NET_CLIENT_DRIVER_TAP); 237 238 return !!s->host_vnet_hdr_len; 239 } 240 241 static bool tap_has_vnet_hdr_len(NetClientState *nc, int len) 242 { 243 TAPState *s = DO_UPCAST(TAPState, nc, nc); 244 245 assert(nc->info->type == NET_CLIENT_DRIVER_TAP); 246 247 return !!tap_probe_vnet_hdr_len(s->fd, len); 248 } 249 250 static void tap_set_vnet_hdr_len(NetClientState *nc, int len) 251 { 252 TAPState *s = DO_UPCAST(TAPState, nc, nc); 253 254 assert(nc->info->type == NET_CLIENT_DRIVER_TAP); 255 assert(len == sizeof(struct virtio_net_hdr_mrg_rxbuf) || 256 len == sizeof(struct virtio_net_hdr)); 257 258 tap_fd_set_vnet_hdr_len(s->fd, len); 259 s->host_vnet_hdr_len = len; 260 } 261 262 static void tap_using_vnet_hdr(NetClientState *nc, bool using_vnet_hdr) 263 { 264 TAPState *s = DO_UPCAST(TAPState, nc, nc); 265 266 assert(nc->info->type == NET_CLIENT_DRIVER_TAP); 267 assert(!!s->host_vnet_hdr_len == using_vnet_hdr); 268 269 s->using_vnet_hdr = using_vnet_hdr; 270 } 271 272 static int tap_set_vnet_le(NetClientState *nc, bool is_le) 273 { 274 TAPState *s = DO_UPCAST(TAPState, nc, nc); 275 276 return tap_fd_set_vnet_le(s->fd, is_le); 277 } 278 279 static int tap_set_vnet_be(NetClientState *nc, bool is_be) 280 { 281 TAPState *s = DO_UPCAST(TAPState, nc, nc); 282 283 return tap_fd_set_vnet_be(s->fd, is_be); 284 } 285 286 static void tap_set_offload(NetClientState *nc, int csum, int tso4, 287 int tso6, int ecn, int ufo) 288 { 289 TAPState *s = DO_UPCAST(TAPState, nc, nc); 290 if (s->fd < 0) { 291 return; 292 } 293 294 tap_fd_set_offload(s->fd, csum, tso4, tso6, ecn, ufo); 295 } 296 297 static void tap_exit_notify(Notifier *notifier, void *data) 298 { 299 TAPState *s = container_of(notifier, TAPState, exit); 300 Error *err = NULL; 301 302 if (s->down_script[0]) { 303 launch_script(s->down_script, s->down_script_arg, s->fd, &err); 304 if (err) { 305 error_report_err(err); 306 } 307 } 308 } 309 310 static void tap_cleanup(NetClientState *nc) 311 { 312 TAPState *s = DO_UPCAST(TAPState, nc, nc); 313 314 if (s->vhost_net) { 315 vhost_net_cleanup(s->vhost_net); 316 g_free(s->vhost_net); 317 s->vhost_net = NULL; 318 } 319 320 qemu_purge_queued_packets(nc); 321 322 tap_exit_notify(&s->exit, NULL); 323 qemu_remove_exit_notifier(&s->exit); 324 325 tap_read_poll(s, false); 326 tap_write_poll(s, false); 327 close(s->fd); 328 s->fd = -1; 329 } 330 331 static void tap_poll(NetClientState *nc, bool enable) 332 { 333 TAPState *s = DO_UPCAST(TAPState, nc, nc); 334 tap_read_poll(s, enable); 335 tap_write_poll(s, enable); 336 } 337 338 int tap_get_fd(NetClientState *nc) 339 { 340 TAPState *s = DO_UPCAST(TAPState, nc, nc); 341 assert(nc->info->type == NET_CLIENT_DRIVER_TAP); 342 return s->fd; 343 } 344 345 /* fd support */ 346 347 static NetClientInfo net_tap_info = { 348 .type = NET_CLIENT_DRIVER_TAP, 349 .size = sizeof(TAPState), 350 .receive = tap_receive, 351 .receive_raw = tap_receive_raw, 352 .receive_iov = tap_receive_iov, 353 .poll = tap_poll, 354 .cleanup = tap_cleanup, 355 .has_ufo = tap_has_ufo, 356 .has_vnet_hdr = tap_has_vnet_hdr, 357 .has_vnet_hdr_len = tap_has_vnet_hdr_len, 358 .using_vnet_hdr = tap_using_vnet_hdr, 359 .set_offload = tap_set_offload, 360 .set_vnet_hdr_len = tap_set_vnet_hdr_len, 361 .set_vnet_le = tap_set_vnet_le, 362 .set_vnet_be = tap_set_vnet_be, 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->enabled = true; 383 tap_set_offload(&s->nc, 0, 0, 0, 0, 0); 384 /* 385 * Make sure host header length is set correctly in tap: 386 * it might have been modified by another instance of qemu. 387 */ 388 if (tap_probe_vnet_hdr_len(s->fd, s->host_vnet_hdr_len)) { 389 tap_fd_set_vnet_hdr_len(s->fd, s->host_vnet_hdr_len); 390 } 391 tap_read_poll(s, true); 392 s->vhost_net = NULL; 393 394 s->exit.notify = tap_exit_notify; 395 qemu_add_exit_notifier(&s->exit); 396 397 return s; 398 } 399 400 static void launch_script(const char *setup_script, const char *ifname, 401 int fd, Error **errp) 402 { 403 int pid, status; 404 char *args[3]; 405 char **parg; 406 407 /* try to launch network script */ 408 pid = fork(); 409 if (pid < 0) { 410 error_setg_errno(errp, errno, "could not launch network script %s", 411 setup_script); 412 return; 413 } 414 if (pid == 0) { 415 int open_max = sysconf(_SC_OPEN_MAX), i; 416 417 for (i = 3; i < open_max; i++) { 418 if (i != fd) { 419 close(i); 420 } 421 } 422 parg = args; 423 *parg++ = (char *)setup_script; 424 *parg++ = (char *)ifname; 425 *parg = NULL; 426 execv(setup_script, args); 427 _exit(1); 428 } else { 429 while (waitpid(pid, &status, 0) != pid) { 430 /* loop */ 431 } 432 433 if (WIFEXITED(status) && WEXITSTATUS(status) == 0) { 434 return; 435 } 436 error_setg(errp, "network script %s failed with status %d", 437 setup_script, status); 438 } 439 } 440 441 static int recv_fd(int c) 442 { 443 int fd; 444 uint8_t msgbuf[CMSG_SPACE(sizeof(fd))]; 445 struct msghdr msg = { 446 .msg_control = msgbuf, 447 .msg_controllen = sizeof(msgbuf), 448 }; 449 struct cmsghdr *cmsg; 450 struct iovec iov; 451 uint8_t req[1]; 452 ssize_t len; 453 454 cmsg = CMSG_FIRSTHDR(&msg); 455 cmsg->cmsg_level = SOL_SOCKET; 456 cmsg->cmsg_type = SCM_RIGHTS; 457 cmsg->cmsg_len = CMSG_LEN(sizeof(fd)); 458 msg.msg_controllen = cmsg->cmsg_len; 459 460 iov.iov_base = req; 461 iov.iov_len = sizeof(req); 462 463 msg.msg_iov = &iov; 464 msg.msg_iovlen = 1; 465 466 len = recvmsg(c, &msg, 0); 467 if (len > 0) { 468 memcpy(&fd, CMSG_DATA(cmsg), sizeof(fd)); 469 return fd; 470 } 471 472 return len; 473 } 474 475 static int net_bridge_run_helper(const char *helper, const char *bridge, 476 Error **errp) 477 { 478 sigset_t oldmask, mask; 479 int pid, status; 480 char *args[5]; 481 char **parg; 482 int sv[2]; 483 484 sigemptyset(&mask); 485 sigaddset(&mask, SIGCHLD); 486 sigprocmask(SIG_BLOCK, &mask, &oldmask); 487 488 if (socketpair(PF_UNIX, SOCK_STREAM, 0, sv) == -1) { 489 error_setg_errno(errp, errno, "socketpair() failed"); 490 return -1; 491 } 492 493 /* try to launch bridge helper */ 494 pid = fork(); 495 if (pid < 0) { 496 error_setg_errno(errp, errno, "Can't fork bridge helper"); 497 return -1; 498 } 499 if (pid == 0) { 500 int open_max = sysconf(_SC_OPEN_MAX), i; 501 char fd_buf[6+10]; 502 char br_buf[6+IFNAMSIZ] = {0}; 503 char helper_cmd[PATH_MAX + sizeof(fd_buf) + sizeof(br_buf) + 15]; 504 505 for (i = 3; i < open_max; i++) { 506 if (i != sv[1]) { 507 close(i); 508 } 509 } 510 511 snprintf(fd_buf, sizeof(fd_buf), "%s%d", "--fd=", sv[1]); 512 513 if (strrchr(helper, ' ') || strrchr(helper, '\t')) { 514 /* assume helper is a command */ 515 516 if (strstr(helper, "--br=") == NULL) { 517 snprintf(br_buf, sizeof(br_buf), "%s%s", "--br=", bridge); 518 } 519 520 snprintf(helper_cmd, sizeof(helper_cmd), "%s %s %s %s", 521 helper, "--use-vnet", fd_buf, br_buf); 522 523 parg = args; 524 *parg++ = (char *)"sh"; 525 *parg++ = (char *)"-c"; 526 *parg++ = helper_cmd; 527 *parg++ = NULL; 528 529 execv("/bin/sh", args); 530 } else { 531 /* assume helper is just the executable path name */ 532 533 snprintf(br_buf, sizeof(br_buf), "%s%s", "--br=", bridge); 534 535 parg = args; 536 *parg++ = (char *)helper; 537 *parg++ = (char *)"--use-vnet"; 538 *parg++ = fd_buf; 539 *parg++ = br_buf; 540 *parg++ = NULL; 541 542 execv(helper, args); 543 } 544 _exit(1); 545 546 } else { 547 int fd; 548 int saved_errno; 549 550 close(sv[1]); 551 552 do { 553 fd = recv_fd(sv[0]); 554 } while (fd == -1 && errno == EINTR); 555 saved_errno = errno; 556 557 close(sv[0]); 558 559 while (waitpid(pid, &status, 0) != pid) { 560 /* loop */ 561 } 562 sigprocmask(SIG_SETMASK, &oldmask, NULL); 563 if (fd < 0) { 564 error_setg_errno(errp, saved_errno, 565 "failed to recv file descriptor"); 566 return -1; 567 } 568 if (!WIFEXITED(status) || WEXITSTATUS(status) != 0) { 569 error_setg(errp, "bridge helper failed"); 570 return -1; 571 } 572 return fd; 573 } 574 } 575 576 int net_init_bridge(const Netdev *netdev, const char *name, 577 NetClientState *peer, Error **errp) 578 { 579 const NetdevBridgeOptions *bridge; 580 const char *helper, *br; 581 TAPState *s; 582 int fd, vnet_hdr; 583 584 assert(netdev->type == NET_CLIENT_DRIVER_BRIDGE); 585 bridge = &netdev->u.bridge; 586 587 helper = bridge->has_helper ? bridge->helper : DEFAULT_BRIDGE_HELPER; 588 br = bridge->has_br ? bridge->br : DEFAULT_BRIDGE_INTERFACE; 589 590 fd = net_bridge_run_helper(helper, br, errp); 591 if (fd == -1) { 592 return -1; 593 } 594 595 fcntl(fd, F_SETFL, O_NONBLOCK); 596 vnet_hdr = tap_probe_vnet_hdr(fd); 597 s = net_tap_fd_init(peer, "bridge", name, fd, vnet_hdr); 598 599 snprintf(s->nc.info_str, sizeof(s->nc.info_str), "helper=%s,br=%s", helper, 600 br); 601 602 return 0; 603 } 604 605 static int net_tap_init(const NetdevTapOptions *tap, int *vnet_hdr, 606 const char *setup_script, char *ifname, 607 size_t ifname_sz, int mq_required, Error **errp) 608 { 609 Error *err = NULL; 610 int fd, vnet_hdr_required; 611 612 if (tap->has_vnet_hdr) { 613 *vnet_hdr = tap->vnet_hdr; 614 vnet_hdr_required = *vnet_hdr; 615 } else { 616 *vnet_hdr = 1; 617 vnet_hdr_required = 0; 618 } 619 620 TFR(fd = tap_open(ifname, ifname_sz, vnet_hdr, vnet_hdr_required, 621 mq_required, errp)); 622 if (fd < 0) { 623 return -1; 624 } 625 626 if (setup_script && 627 setup_script[0] != '\0' && 628 strcmp(setup_script, "no") != 0) { 629 launch_script(setup_script, ifname, fd, &err); 630 if (err) { 631 error_propagate(errp, err); 632 close(fd); 633 return -1; 634 } 635 } 636 637 return fd; 638 } 639 640 #define MAX_TAP_QUEUES 1024 641 642 static void net_init_tap_one(const NetdevTapOptions *tap, NetClientState *peer, 643 const char *model, const char *name, 644 const char *ifname, const char *script, 645 const char *downscript, const char *vhostfdname, 646 int vnet_hdr, int fd, Error **errp) 647 { 648 Error *err = NULL; 649 TAPState *s = net_tap_fd_init(peer, model, name, fd, vnet_hdr); 650 int vhostfd; 651 652 tap_set_sndbuf(s->fd, tap, &err); 653 if (err) { 654 error_propagate(errp, err); 655 return; 656 } 657 658 if (tap->has_fd || tap->has_fds) { 659 snprintf(s->nc.info_str, sizeof(s->nc.info_str), "fd=%d", fd); 660 } else if (tap->has_helper) { 661 snprintf(s->nc.info_str, sizeof(s->nc.info_str), "helper=%s", 662 tap->helper); 663 } else { 664 snprintf(s->nc.info_str, sizeof(s->nc.info_str), 665 "ifname=%s,script=%s,downscript=%s", ifname, script, 666 downscript); 667 668 if (strcmp(downscript, "no") != 0) { 669 snprintf(s->down_script, sizeof(s->down_script), "%s", downscript); 670 snprintf(s->down_script_arg, sizeof(s->down_script_arg), 671 "%s", ifname); 672 } 673 } 674 675 if (tap->has_vhost ? tap->vhost : 676 vhostfdname || (tap->has_vhostforce && tap->vhostforce)) { 677 VhostNetOptions options; 678 679 options.backend_type = VHOST_BACKEND_TYPE_KERNEL; 680 options.net_backend = &s->nc; 681 if (tap->has_poll_us) { 682 options.busyloop_timeout = tap->poll_us; 683 } else { 684 options.busyloop_timeout = 0; 685 } 686 687 if (vhostfdname) { 688 vhostfd = monitor_fd_param(cur_mon, vhostfdname, &err); 689 if (vhostfd == -1) { 690 if (tap->has_vhostforce && tap->vhostforce) { 691 error_propagate(errp, err); 692 } else { 693 warn_report_err(err); 694 } 695 return; 696 } 697 qemu_set_nonblock(vhostfd); 698 } else { 699 vhostfd = open("/dev/vhost-net", O_RDWR); 700 if (vhostfd < 0) { 701 if (tap->has_vhostforce && tap->vhostforce) { 702 error_setg_errno(errp, errno, 703 "tap: open vhost char device failed"); 704 } else { 705 warn_report("tap: open vhost char device failed: %s", 706 strerror(errno)); 707 } 708 return; 709 } 710 fcntl(vhostfd, F_SETFL, O_NONBLOCK); 711 } 712 options.opaque = (void *)(uintptr_t)vhostfd; 713 714 s->vhost_net = vhost_net_init(&options); 715 if (!s->vhost_net) { 716 if (tap->has_vhostforce && tap->vhostforce) { 717 error_setg(errp, VHOST_NET_INIT_FAILED); 718 } else { 719 warn_report(VHOST_NET_INIT_FAILED); 720 } 721 return; 722 } 723 } else if (vhostfdname) { 724 error_setg(errp, "vhostfd(s)= is not valid without vhost"); 725 } 726 } 727 728 static int get_fds(char *str, char *fds[], int max) 729 { 730 char *ptr = str, *this; 731 size_t len = strlen(str); 732 int i = 0; 733 734 while (i < max && ptr < str + len) { 735 this = strchr(ptr, ':'); 736 737 if (this == NULL) { 738 fds[i] = g_strdup(ptr); 739 } else { 740 fds[i] = g_strndup(ptr, this - ptr); 741 } 742 743 i++; 744 if (this == NULL) { 745 break; 746 } else { 747 ptr = this + 1; 748 } 749 } 750 751 return i; 752 } 753 754 int net_init_tap(const Netdev *netdev, const char *name, 755 NetClientState *peer, Error **errp) 756 { 757 const NetdevTapOptions *tap; 758 int fd, vnet_hdr = 0, i = 0, queues; 759 /* for the no-fd, no-helper case */ 760 const char *script = NULL; /* suppress wrong "uninit'd use" gcc warning */ 761 const char *downscript = NULL; 762 Error *err = NULL; 763 const char *vhostfdname; 764 char ifname[128]; 765 766 assert(netdev->type == NET_CLIENT_DRIVER_TAP); 767 tap = &netdev->u.tap; 768 queues = tap->has_queues ? tap->queues : 1; 769 vhostfdname = tap->has_vhostfd ? tap->vhostfd : NULL; 770 771 /* QEMU hubs do not support multiqueue tap, in this case peer is set. 772 * For -netdev, peer is always NULL. */ 773 if (peer && (tap->has_queues || tap->has_fds || tap->has_vhostfds)) { 774 error_setg(errp, "Multiqueue tap cannot be used with hubs"); 775 return -1; 776 } 777 778 if (tap->has_fd) { 779 if (tap->has_ifname || tap->has_script || tap->has_downscript || 780 tap->has_vnet_hdr || tap->has_helper || tap->has_queues || 781 tap->has_fds || tap->has_vhostfds) { 782 error_setg(errp, "ifname=, script=, downscript=, vnet_hdr=, " 783 "helper=, queues=, fds=, and vhostfds= " 784 "are invalid with fd="); 785 return -1; 786 } 787 788 fd = monitor_fd_param(cur_mon, tap->fd, &err); 789 if (fd == -1) { 790 error_propagate(errp, err); 791 return -1; 792 } 793 794 fcntl(fd, F_SETFL, O_NONBLOCK); 795 796 vnet_hdr = tap_probe_vnet_hdr(fd); 797 798 net_init_tap_one(tap, peer, "tap", name, NULL, 799 script, downscript, 800 vhostfdname, vnet_hdr, fd, &err); 801 if (err) { 802 error_propagate(errp, err); 803 return -1; 804 } 805 } else if (tap->has_fds) { 806 char **fds; 807 char **vhost_fds; 808 int nfds = 0, nvhosts = 0; 809 int ret = 0; 810 811 if (tap->has_ifname || tap->has_script || tap->has_downscript || 812 tap->has_vnet_hdr || tap->has_helper || tap->has_queues || 813 tap->has_vhostfd) { 814 error_setg(errp, "ifname=, script=, downscript=, vnet_hdr=, " 815 "helper=, queues=, and vhostfd= " 816 "are invalid with fds="); 817 return -1; 818 } 819 820 fds = g_new0(char *, MAX_TAP_QUEUES); 821 vhost_fds = g_new0(char *, MAX_TAP_QUEUES); 822 823 nfds = get_fds(tap->fds, fds, MAX_TAP_QUEUES); 824 if (tap->has_vhostfds) { 825 nvhosts = get_fds(tap->vhostfds, vhost_fds, MAX_TAP_QUEUES); 826 if (nfds != nvhosts) { 827 error_setg(errp, "The number of fds passed does not match " 828 "the number of vhostfds passed"); 829 ret = -1; 830 goto free_fail; 831 } 832 } 833 834 for (i = 0; i < nfds; i++) { 835 fd = monitor_fd_param(cur_mon, fds[i], &err); 836 if (fd == -1) { 837 error_propagate(errp, err); 838 ret = -1; 839 goto free_fail; 840 } 841 842 fcntl(fd, F_SETFL, O_NONBLOCK); 843 844 if (i == 0) { 845 vnet_hdr = tap_probe_vnet_hdr(fd); 846 } else if (vnet_hdr != tap_probe_vnet_hdr(fd)) { 847 error_setg(errp, 848 "vnet_hdr not consistent across given tap fds"); 849 ret = -1; 850 goto free_fail; 851 } 852 853 net_init_tap_one(tap, peer, "tap", name, ifname, 854 script, downscript, 855 tap->has_vhostfds ? vhost_fds[i] : NULL, 856 vnet_hdr, fd, &err); 857 if (err) { 858 error_propagate(errp, err); 859 ret = -1; 860 goto free_fail; 861 } 862 } 863 864 free_fail: 865 for (i = 0; i < nvhosts; i++) { 866 g_free(vhost_fds[i]); 867 } 868 for (i = 0; i < nfds; i++) { 869 g_free(fds[i]); 870 } 871 g_free(fds); 872 g_free(vhost_fds); 873 return ret; 874 } else if (tap->has_helper) { 875 if (tap->has_ifname || tap->has_script || tap->has_downscript || 876 tap->has_vnet_hdr || tap->has_queues || tap->has_vhostfds) { 877 error_setg(errp, "ifname=, script=, downscript=, vnet_hdr=, " 878 "queues=, and vhostfds= are invalid with helper="); 879 return -1; 880 } 881 882 fd = net_bridge_run_helper(tap->helper, 883 tap->has_br ? 884 tap->br : DEFAULT_BRIDGE_INTERFACE, 885 errp); 886 if (fd == -1) { 887 return -1; 888 } 889 890 fcntl(fd, F_SETFL, O_NONBLOCK); 891 vnet_hdr = tap_probe_vnet_hdr(fd); 892 893 net_init_tap_one(tap, peer, "bridge", name, ifname, 894 script, downscript, vhostfdname, 895 vnet_hdr, fd, &err); 896 if (err) { 897 error_propagate(errp, err); 898 close(fd); 899 return -1; 900 } 901 } else { 902 if (tap->has_vhostfds) { 903 error_setg(errp, "vhostfds= is invalid if fds= wasn't specified"); 904 return -1; 905 } 906 script = tap->has_script ? tap->script : DEFAULT_NETWORK_SCRIPT; 907 downscript = tap->has_downscript ? tap->downscript : 908 DEFAULT_NETWORK_DOWN_SCRIPT; 909 910 if (tap->has_ifname) { 911 pstrcpy(ifname, sizeof ifname, tap->ifname); 912 } else { 913 ifname[0] = '\0'; 914 } 915 916 for (i = 0; i < queues; i++) { 917 fd = net_tap_init(tap, &vnet_hdr, i >= 1 ? "no" : script, 918 ifname, sizeof ifname, queues > 1, errp); 919 if (fd == -1) { 920 return -1; 921 } 922 923 if (queues > 1 && i == 0 && !tap->has_ifname) { 924 if (tap_fd_get_ifname(fd, ifname)) { 925 error_setg(errp, "Fail to get ifname"); 926 close(fd); 927 return -1; 928 } 929 } 930 931 net_init_tap_one(tap, peer, "tap", name, ifname, 932 i >= 1 ? "no" : script, 933 i >= 1 ? "no" : downscript, 934 vhostfdname, vnet_hdr, fd, &err); 935 if (err) { 936 error_propagate(errp, err); 937 close(fd); 938 return -1; 939 } 940 } 941 } 942 943 return 0; 944 } 945 946 VHostNetState *tap_get_vhost_net(NetClientState *nc) 947 { 948 TAPState *s = DO_UPCAST(TAPState, nc, nc); 949 assert(nc->info->type == NET_CLIENT_DRIVER_TAP); 950 return s->vhost_net; 951 } 952 953 int tap_enable(NetClientState *nc) 954 { 955 TAPState *s = DO_UPCAST(TAPState, nc, nc); 956 int ret; 957 958 if (s->enabled) { 959 return 0; 960 } else { 961 ret = tap_fd_enable(s->fd); 962 if (ret == 0) { 963 s->enabled = true; 964 tap_update_fd_handler(s); 965 } 966 return ret; 967 } 968 } 969 970 int tap_disable(NetClientState *nc) 971 { 972 TAPState *s = DO_UPCAST(TAPState, nc, nc); 973 int ret; 974 975 if (s->enabled == 0) { 976 return 0; 977 } else { 978 ret = tap_fd_disable(s->fd); 979 if (ret == 0) { 980 qemu_purge_queued_packets(nc); 981 s->enabled = false; 982 tap_update_fd_handler(s); 983 } 984 return ret; 985 } 986 } 987