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 (!s->nc.peer->do_not_pad) { 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 int tap_get_fd(NetClientState *nc) 351 { 352 TAPState *s = DO_UPCAST(TAPState, nc, nc); 353 assert(nc->info->type == NET_CLIENT_DRIVER_TAP); 354 return s->fd; 355 } 356 357 /* fd support */ 358 359 static NetClientInfo net_tap_info = { 360 .type = NET_CLIENT_DRIVER_TAP, 361 .size = sizeof(TAPState), 362 .receive = tap_receive, 363 .receive_raw = tap_receive_raw, 364 .receive_iov = tap_receive_iov, 365 .poll = tap_poll, 366 .cleanup = tap_cleanup, 367 .has_ufo = tap_has_ufo, 368 .has_vnet_hdr = tap_has_vnet_hdr, 369 .has_vnet_hdr_len = tap_has_vnet_hdr_len, 370 .using_vnet_hdr = tap_using_vnet_hdr, 371 .set_offload = tap_set_offload, 372 .set_vnet_hdr_len = tap_set_vnet_hdr_len, 373 .set_vnet_le = tap_set_vnet_le, 374 .set_vnet_be = tap_set_vnet_be, 375 }; 376 377 static TAPState *net_tap_fd_init(NetClientState *peer, 378 const char *model, 379 const char *name, 380 int fd, 381 int vnet_hdr) 382 { 383 NetClientState *nc; 384 TAPState *s; 385 386 nc = qemu_new_net_client(&net_tap_info, peer, model, name); 387 388 s = DO_UPCAST(TAPState, nc, nc); 389 390 s->fd = fd; 391 s->host_vnet_hdr_len = vnet_hdr ? sizeof(struct virtio_net_hdr) : 0; 392 s->using_vnet_hdr = false; 393 s->has_ufo = tap_probe_has_ufo(s->fd); 394 s->enabled = true; 395 tap_set_offload(&s->nc, 0, 0, 0, 0, 0); 396 /* 397 * Make sure host header length is set correctly in tap: 398 * it might have been modified by another instance of qemu. 399 */ 400 if (tap_probe_vnet_hdr_len(s->fd, s->host_vnet_hdr_len)) { 401 tap_fd_set_vnet_hdr_len(s->fd, s->host_vnet_hdr_len); 402 } 403 tap_read_poll(s, true); 404 s->vhost_net = NULL; 405 406 s->exit.notify = tap_exit_notify; 407 qemu_add_exit_notifier(&s->exit); 408 409 return s; 410 } 411 412 static void launch_script(const char *setup_script, const char *ifname, 413 int fd, Error **errp) 414 { 415 int pid, status; 416 char *args[3]; 417 char **parg; 418 419 /* try to launch network script */ 420 pid = fork(); 421 if (pid < 0) { 422 error_setg_errno(errp, errno, "could not launch network script %s", 423 setup_script); 424 return; 425 } 426 if (pid == 0) { 427 int open_max = sysconf(_SC_OPEN_MAX), i; 428 429 for (i = 3; i < open_max; i++) { 430 if (i != fd) { 431 close(i); 432 } 433 } 434 parg = args; 435 *parg++ = (char *)setup_script; 436 *parg++ = (char *)ifname; 437 *parg = NULL; 438 execv(setup_script, args); 439 _exit(1); 440 } else { 441 while (waitpid(pid, &status, 0) != pid) { 442 /* loop */ 443 } 444 445 if (WIFEXITED(status) && WEXITSTATUS(status) == 0) { 446 return; 447 } 448 error_setg(errp, "network script %s failed with status %d", 449 setup_script, status); 450 } 451 } 452 453 static int recv_fd(int c) 454 { 455 int fd; 456 uint8_t msgbuf[CMSG_SPACE(sizeof(fd))]; 457 struct msghdr msg = { 458 .msg_control = msgbuf, 459 .msg_controllen = sizeof(msgbuf), 460 }; 461 struct cmsghdr *cmsg; 462 struct iovec iov; 463 uint8_t req[1]; 464 ssize_t len; 465 466 cmsg = CMSG_FIRSTHDR(&msg); 467 cmsg->cmsg_level = SOL_SOCKET; 468 cmsg->cmsg_type = SCM_RIGHTS; 469 cmsg->cmsg_len = CMSG_LEN(sizeof(fd)); 470 msg.msg_controllen = cmsg->cmsg_len; 471 472 iov.iov_base = req; 473 iov.iov_len = sizeof(req); 474 475 msg.msg_iov = &iov; 476 msg.msg_iovlen = 1; 477 478 len = recvmsg(c, &msg, 0); 479 if (len > 0) { 480 memcpy(&fd, CMSG_DATA(cmsg), sizeof(fd)); 481 return fd; 482 } 483 484 return len; 485 } 486 487 static int net_bridge_run_helper(const char *helper, const char *bridge, 488 Error **errp) 489 { 490 sigset_t oldmask, mask; 491 g_autofree char *default_helper = NULL; 492 int pid, status; 493 char *args[5]; 494 char **parg; 495 int sv[2]; 496 497 sigemptyset(&mask); 498 sigaddset(&mask, SIGCHLD); 499 sigprocmask(SIG_BLOCK, &mask, &oldmask); 500 501 if (!helper) { 502 helper = default_helper = get_relocated_path(DEFAULT_BRIDGE_HELPER); 503 } 504 505 if (socketpair(PF_UNIX, SOCK_STREAM, 0, sv) == -1) { 506 error_setg_errno(errp, errno, "socketpair() failed"); 507 return -1; 508 } 509 510 /* try to launch bridge helper */ 511 pid = fork(); 512 if (pid < 0) { 513 error_setg_errno(errp, errno, "Can't fork bridge helper"); 514 return -1; 515 } 516 if (pid == 0) { 517 int open_max = sysconf(_SC_OPEN_MAX), i; 518 char *fd_buf = NULL; 519 char *br_buf = NULL; 520 char *helper_cmd = NULL; 521 522 for (i = 3; i < open_max; i++) { 523 if (i != sv[1]) { 524 close(i); 525 } 526 } 527 528 fd_buf = g_strdup_printf("%s%d", "--fd=", sv[1]); 529 530 if (strrchr(helper, ' ') || strrchr(helper, '\t')) { 531 /* assume helper is a command */ 532 533 if (strstr(helper, "--br=") == NULL) { 534 br_buf = g_strdup_printf("%s%s", "--br=", bridge); 535 } 536 537 helper_cmd = g_strdup_printf("%s %s %s %s", helper, 538 "--use-vnet", fd_buf, br_buf ? br_buf : ""); 539 540 parg = args; 541 *parg++ = (char *)"sh"; 542 *parg++ = (char *)"-c"; 543 *parg++ = helper_cmd; 544 *parg++ = NULL; 545 546 execv("/bin/sh", args); 547 g_free(helper_cmd); 548 } else { 549 /* assume helper is just the executable path name */ 550 551 br_buf = g_strdup_printf("%s%s", "--br=", bridge); 552 553 parg = args; 554 *parg++ = (char *)helper; 555 *parg++ = (char *)"--use-vnet"; 556 *parg++ = fd_buf; 557 *parg++ = br_buf; 558 *parg++ = NULL; 559 560 execv(helper, args); 561 } 562 g_free(fd_buf); 563 g_free(br_buf); 564 _exit(1); 565 566 } else { 567 int fd; 568 int saved_errno; 569 570 close(sv[1]); 571 572 do { 573 fd = recv_fd(sv[0]); 574 } while (fd == -1 && errno == EINTR); 575 saved_errno = errno; 576 577 close(sv[0]); 578 579 while (waitpid(pid, &status, 0) != pid) { 580 /* loop */ 581 } 582 sigprocmask(SIG_SETMASK, &oldmask, NULL); 583 if (fd < 0) { 584 error_setg_errno(errp, saved_errno, 585 "failed to recv file descriptor"); 586 return -1; 587 } 588 if (!WIFEXITED(status) || WEXITSTATUS(status) != 0) { 589 error_setg(errp, "bridge helper failed"); 590 return -1; 591 } 592 return fd; 593 } 594 } 595 596 int net_init_bridge(const Netdev *netdev, const char *name, 597 NetClientState *peer, Error **errp) 598 { 599 const NetdevBridgeOptions *bridge; 600 const char *helper, *br; 601 TAPState *s; 602 int fd, vnet_hdr; 603 NetdevBridgeOptions *stored; 604 605 assert(netdev->type == NET_CLIENT_DRIVER_BRIDGE); 606 bridge = &netdev->u.bridge; 607 helper = bridge->has_helper ? bridge->helper : NULL; 608 br = bridge->has_br ? bridge->br : DEFAULT_BRIDGE_INTERFACE; 609 610 fd = net_bridge_run_helper(helper, br, errp); 611 if (fd == -1) { 612 return -1; 613 } 614 615 qemu_set_nonblock(fd); 616 vnet_hdr = tap_probe_vnet_hdr(fd, errp); 617 if (vnet_hdr < 0) { 618 close(fd); 619 return -1; 620 } 621 s = net_tap_fd_init(peer, "bridge", name, fd, vnet_hdr); 622 623 /* Store startup parameters */ 624 s->nc.stored_config = g_new0(NetdevInfo, 1); 625 s->nc.stored_config->type = NET_BACKEND_BRIDGE; 626 stored = &s->nc.stored_config->u.bridge; 627 628 if (br) { 629 stored->has_br = true; 630 stored->br = g_strdup(br); 631 } 632 633 if (helper) { 634 stored->has_helper = true; 635 stored->helper = g_strdup(helper); 636 } 637 638 s->nc.info_str = g_strdup_printf("helper=%s,br=%s", helper, br); 639 640 return 0; 641 } 642 643 static int net_tap_init(const NetdevTapOptions *tap, int *vnet_hdr, 644 const char *setup_script, char *ifname, 645 size_t ifname_sz, int mq_required, Error **errp) 646 { 647 Error *err = NULL; 648 int fd, vnet_hdr_required; 649 650 if (tap->has_vnet_hdr) { 651 *vnet_hdr = tap->vnet_hdr; 652 vnet_hdr_required = *vnet_hdr; 653 } else { 654 *vnet_hdr = 1; 655 vnet_hdr_required = 0; 656 } 657 658 TFR(fd = tap_open(ifname, ifname_sz, vnet_hdr, vnet_hdr_required, 659 mq_required, errp)); 660 if (fd < 0) { 661 return -1; 662 } 663 664 if (setup_script && 665 setup_script[0] != '\0' && 666 strcmp(setup_script, "no") != 0) { 667 launch_script(setup_script, ifname, fd, &err); 668 if (err) { 669 error_propagate(errp, err); 670 close(fd); 671 return -1; 672 } 673 } 674 675 return fd; 676 } 677 678 #define MAX_TAP_QUEUES 1024 679 680 static void net_init_tap_one(const NetdevTapOptions *tap, NetClientState *peer, 681 const char *model, const char *name, 682 const char *ifname, const char *script, 683 const char *downscript, const char *vhostfdname, 684 int vnet_hdr, int fd, NetdevInfo **common_stored, 685 Error **errp) 686 { 687 Error *err = NULL; 688 TAPState *s = net_tap_fd_init(peer, model, name, fd, vnet_hdr); 689 int vhostfd; 690 NetdevTapOptions *stored; 691 692 tap_set_sndbuf(s->fd, tap, &err); 693 if (err) { 694 error_propagate(errp, err); 695 return; 696 } 697 698 /* Store startup parameters */ 699 if (!*common_stored) { 700 *common_stored = g_new0(NetdevInfo, 1); 701 (*common_stored)->type = NET_BACKEND_TAP; 702 s->nc.stored_config = *common_stored; 703 } 704 stored = &(*common_stored)->u.tap; 705 706 if (tap->has_sndbuf && !stored->has_sndbuf) { 707 stored->has_sndbuf = true; 708 stored->sndbuf = tap->sndbuf; 709 } 710 711 if (vnet_hdr && !stored->has_vnet_hdr) { 712 stored->has_vnet_hdr = true; 713 stored->vnet_hdr = true; 714 } 715 716 if (tap->has_fd || tap->has_fds) { 717 if (!stored->has_fds) { 718 stored->has_fds = true; 719 stored->fds = g_strdup_printf("%d", fd); 720 } else { 721 char *tmp_s = stored->fds; 722 stored->fds = g_strdup_printf("%s:%d", stored->fds, fd); 723 g_free(tmp_s); 724 } 725 726 s->nc.info_str = g_strdup_printf("fd=%d", fd); 727 } else if (tap->has_helper) { 728 if (!stored->has_helper) { 729 stored->has_helper = true; 730 stored->helper = g_strdup(tap->helper); 731 } 732 733 if (!stored->has_br) { 734 stored->has_br = true; 735 stored->br = tap->has_br ? g_strdup(tap->br) : 736 g_strdup(DEFAULT_BRIDGE_INTERFACE); 737 } 738 739 s->nc.info_str = g_strdup_printf("helper=%s", tap->helper); 740 } else { 741 if (ifname && !stored->has_ifname) { 742 stored->has_ifname = true; 743 stored->ifname = g_strdup(ifname); 744 } 745 746 if (script && !stored->has_script) { 747 stored->has_script = true; 748 stored->script = g_strdup(script); 749 } 750 751 if (downscript && !stored->has_downscript) { 752 stored->has_downscript = true; 753 stored->downscript = g_strdup(downscript); 754 } 755 756 s->nc.info_str = g_strdup_printf("ifname=%s,script=%s,downscript=%s", 757 ifname, script, downscript); 758 759 if (strcmp(downscript, "no") != 0) { 760 snprintf(s->down_script, sizeof(s->down_script), "%s", downscript); 761 snprintf(s->down_script_arg, sizeof(s->down_script_arg), 762 "%s", ifname); 763 } 764 } 765 766 if (tap->has_vhost ? tap->vhost : 767 vhostfdname || (tap->has_vhostforce && tap->vhostforce)) { 768 VhostNetOptions options; 769 770 stored->has_vhost = true; 771 stored->vhost = true; 772 773 if (tap->has_vhostforce && tap->vhostforce) { 774 stored->has_vhostforce = true; 775 stored->vhostforce = true; 776 } 777 778 options.backend_type = VHOST_BACKEND_TYPE_KERNEL; 779 options.net_backend = &s->nc; 780 if (tap->has_poll_us) { 781 stored->has_poll_us = true; 782 stored->poll_us = tap->poll_us; 783 784 options.busyloop_timeout = tap->poll_us; 785 } else { 786 options.busyloop_timeout = 0; 787 } 788 789 if (vhostfdname) { 790 int ret; 791 792 vhostfd = monitor_fd_param(monitor_cur(), vhostfdname, &err); 793 if (vhostfd == -1) { 794 if (tap->has_vhostforce && tap->vhostforce) { 795 error_propagate(errp, err); 796 } else { 797 warn_report_err(err); 798 } 799 return; 800 } 801 ret = qemu_try_set_nonblock(vhostfd); 802 if (ret < 0) { 803 error_setg_errno(errp, -ret, "%s: Can't use file descriptor %d", 804 name, fd); 805 return; 806 } 807 } else { 808 vhostfd = open("/dev/vhost-net", O_RDWR); 809 if (vhostfd < 0) { 810 if (tap->has_vhostforce && tap->vhostforce) { 811 error_setg_errno(errp, errno, 812 "tap: open vhost char device failed"); 813 } else { 814 warn_report("tap: open vhost char device failed: %s", 815 strerror(errno)); 816 } 817 return; 818 } 819 qemu_set_nonblock(vhostfd); 820 } 821 options.opaque = (void *)(uintptr_t)vhostfd; 822 823 if (!stored->has_vhostfds) { 824 stored->has_vhostfds = true; 825 stored->vhostfds = g_strdup_printf("%d", vhostfd); 826 } else { 827 char *tmp_s = stored->vhostfds; 828 stored->vhostfds = g_strdup_printf("%s:%d", stored->fds, vhostfd); 829 g_free(tmp_s); 830 } 831 832 s->vhost_net = vhost_net_init(&options); 833 if (!s->vhost_net) { 834 if (tap->has_vhostforce && tap->vhostforce) { 835 error_setg(errp, VHOST_NET_INIT_FAILED); 836 } else { 837 warn_report(VHOST_NET_INIT_FAILED); 838 } 839 return; 840 } 841 } else if (vhostfdname) { 842 error_setg(errp, "vhostfd(s)= is not valid without vhost"); 843 } 844 } 845 846 static int get_fds(char *str, char *fds[], int max) 847 { 848 char *ptr = str, *this; 849 size_t len = strlen(str); 850 int i = 0; 851 852 while (i < max && ptr < str + len) { 853 this = strchr(ptr, ':'); 854 855 if (this == NULL) { 856 fds[i] = g_strdup(ptr); 857 } else { 858 fds[i] = g_strndup(ptr, this - ptr); 859 } 860 861 i++; 862 if (this == NULL) { 863 break; 864 } else { 865 ptr = this + 1; 866 } 867 } 868 869 return i; 870 } 871 872 int net_init_tap(const Netdev *netdev, const char *name, 873 NetClientState *peer, Error **errp) 874 { 875 const NetdevTapOptions *tap; 876 int fd, vnet_hdr = 0, i = 0, queues; 877 /* for the no-fd, no-helper case */ 878 const char *script; 879 const char *downscript; 880 Error *err = NULL; 881 const char *vhostfdname; 882 char ifname[128]; 883 int ret = 0; 884 NetdevInfo *common_stored = NULL; /* will store configuration */ 885 886 assert(netdev->type == NET_CLIENT_DRIVER_TAP); 887 tap = &netdev->u.tap; 888 queues = tap->has_queues ? tap->queues : 1; 889 vhostfdname = tap->has_vhostfd ? tap->vhostfd : NULL; 890 script = tap->has_script ? tap->script : NULL; 891 downscript = tap->has_downscript ? tap->downscript : NULL; 892 893 /* QEMU hubs do not support multiqueue tap, in this case peer is set. 894 * For -netdev, peer is always NULL. */ 895 if (peer && (tap->has_queues || tap->has_fds || tap->has_vhostfds)) { 896 error_setg(errp, "Multiqueue tap cannot be used with hubs"); 897 return -1; 898 } 899 900 if (tap->has_fd) { 901 if (tap->has_ifname || tap->has_script || tap->has_downscript || 902 tap->has_vnet_hdr || tap->has_helper || tap->has_queues || 903 tap->has_fds || tap->has_vhostfds) { 904 error_setg(errp, "ifname=, script=, downscript=, vnet_hdr=, " 905 "helper=, queues=, fds=, and vhostfds= " 906 "are invalid with fd="); 907 return -1; 908 } 909 910 fd = monitor_fd_param(monitor_cur(), tap->fd, errp); 911 if (fd == -1) { 912 return -1; 913 } 914 915 ret = qemu_try_set_nonblock(fd); 916 if (ret < 0) { 917 error_setg_errno(errp, -ret, "%s: Can't use file descriptor %d", 918 name, fd); 919 close(fd); 920 return -1; 921 } 922 923 vnet_hdr = tap_probe_vnet_hdr(fd, errp); 924 if (vnet_hdr < 0) { 925 close(fd); 926 return -1; 927 } 928 929 net_init_tap_one(tap, peer, "tap", name, NULL, 930 script, downscript, 931 vhostfdname, vnet_hdr, fd, &common_stored, &err); 932 if (err) { 933 error_propagate(errp, err); 934 close(fd); 935 return -1; 936 } 937 } else if (tap->has_fds) { 938 char **fds; 939 char **vhost_fds; 940 int nfds = 0, nvhosts = 0; 941 942 if (tap->has_ifname || tap->has_script || tap->has_downscript || 943 tap->has_vnet_hdr || tap->has_helper || tap->has_queues || 944 tap->has_vhostfd) { 945 error_setg(errp, "ifname=, script=, downscript=, vnet_hdr=, " 946 "helper=, queues=, and vhostfd= " 947 "are invalid with fds="); 948 return -1; 949 } 950 951 fds = g_new0(char *, MAX_TAP_QUEUES); 952 vhost_fds = g_new0(char *, MAX_TAP_QUEUES); 953 954 nfds = get_fds(tap->fds, fds, MAX_TAP_QUEUES); 955 if (tap->has_vhostfds) { 956 nvhosts = get_fds(tap->vhostfds, vhost_fds, MAX_TAP_QUEUES); 957 if (nfds != nvhosts) { 958 error_setg(errp, "The number of fds passed does not match " 959 "the number of vhostfds passed"); 960 ret = -1; 961 goto free_fail; 962 } 963 } 964 965 for (i = 0; i < nfds; i++) { 966 fd = monitor_fd_param(monitor_cur(), fds[i], errp); 967 if (fd == -1) { 968 ret = -1; 969 goto free_fail; 970 } 971 972 ret = qemu_try_set_nonblock(fd); 973 if (ret < 0) { 974 error_setg_errno(errp, -ret, "%s: Can't use file descriptor %d", 975 name, fd); 976 goto free_fail; 977 } 978 979 if (i == 0) { 980 vnet_hdr = tap_probe_vnet_hdr(fd, errp); 981 if (vnet_hdr < 0) { 982 goto free_fail; 983 } 984 } else if (vnet_hdr != tap_probe_vnet_hdr(fd, NULL)) { 985 error_setg(errp, 986 "vnet_hdr not consistent across given tap fds"); 987 ret = -1; 988 goto free_fail; 989 } 990 991 net_init_tap_one(tap, peer, "tap", name, ifname, 992 script, downscript, 993 tap->has_vhostfds ? vhost_fds[i] : NULL, 994 vnet_hdr, fd, &common_stored, &err); 995 if (err) { 996 error_propagate(errp, err); 997 ret = -1; 998 goto free_fail; 999 } 1000 } 1001 1002 free_fail: 1003 for (i = 0; i < nvhosts; i++) { 1004 g_free(vhost_fds[i]); 1005 } 1006 for (i = 0; i < nfds; i++) { 1007 g_free(fds[i]); 1008 } 1009 g_free(fds); 1010 g_free(vhost_fds); 1011 return ret; 1012 } else if (tap->has_helper) { 1013 if (tap->has_ifname || tap->has_script || tap->has_downscript || 1014 tap->has_vnet_hdr || tap->has_queues || tap->has_vhostfds) { 1015 error_setg(errp, "ifname=, script=, downscript=, vnet_hdr=, " 1016 "queues=, and vhostfds= are invalid with helper="); 1017 return -1; 1018 } 1019 1020 fd = net_bridge_run_helper(tap->helper, 1021 tap->has_br ? 1022 tap->br : DEFAULT_BRIDGE_INTERFACE, 1023 errp); 1024 if (fd == -1) { 1025 return -1; 1026 } 1027 1028 qemu_set_nonblock(fd); 1029 vnet_hdr = tap_probe_vnet_hdr(fd, errp); 1030 if (vnet_hdr < 0) { 1031 close(fd); 1032 return -1; 1033 } 1034 1035 net_init_tap_one(tap, peer, "bridge", name, ifname, 1036 script, downscript, vhostfdname, 1037 vnet_hdr, fd, &common_stored, &err); 1038 if (err) { 1039 error_propagate(errp, err); 1040 close(fd); 1041 return -1; 1042 } 1043 } else { 1044 g_autofree char *default_script = NULL; 1045 g_autofree char *default_downscript = NULL; 1046 if (tap->has_vhostfds) { 1047 error_setg(errp, "vhostfds= is invalid if fds= wasn't specified"); 1048 return -1; 1049 } 1050 1051 if (!script) { 1052 script = default_script = get_relocated_path(DEFAULT_NETWORK_SCRIPT); 1053 } 1054 if (!downscript) { 1055 downscript = default_downscript = 1056 get_relocated_path(DEFAULT_NETWORK_DOWN_SCRIPT); 1057 } 1058 1059 if (tap->has_ifname) { 1060 pstrcpy(ifname, sizeof ifname, tap->ifname); 1061 } else { 1062 ifname[0] = '\0'; 1063 } 1064 1065 for (i = 0; i < queues; i++) { 1066 fd = net_tap_init(tap, &vnet_hdr, i >= 1 ? "no" : script, 1067 ifname, sizeof ifname, queues > 1, errp); 1068 if (fd == -1) { 1069 return -1; 1070 } 1071 1072 if (queues > 1 && i == 0 && !tap->has_ifname) { 1073 if (tap_fd_get_ifname(fd, ifname)) { 1074 error_setg(errp, "Fail to get ifname"); 1075 close(fd); 1076 return -1; 1077 } 1078 } 1079 1080 net_init_tap_one(tap, peer, "tap", name, ifname, 1081 i >= 1 ? "no" : script, 1082 i >= 1 ? "no" : downscript, 1083 vhostfdname, vnet_hdr, fd, 1084 &common_stored, &err); 1085 if (err) { 1086 error_propagate(errp, err); 1087 close(fd); 1088 return -1; 1089 } 1090 } 1091 } 1092 1093 return 0; 1094 } 1095 1096 VHostNetState *tap_get_vhost_net(NetClientState *nc) 1097 { 1098 TAPState *s = DO_UPCAST(TAPState, nc, nc); 1099 assert(nc->info->type == NET_CLIENT_DRIVER_TAP); 1100 return s->vhost_net; 1101 } 1102 1103 int tap_enable(NetClientState *nc) 1104 { 1105 TAPState *s = DO_UPCAST(TAPState, nc, nc); 1106 int ret; 1107 1108 if (s->enabled) { 1109 return 0; 1110 } else { 1111 ret = tap_fd_enable(s->fd); 1112 if (ret == 0) { 1113 s->enabled = true; 1114 tap_update_fd_handler(s); 1115 } 1116 return ret; 1117 } 1118 } 1119 1120 int tap_disable(NetClientState *nc) 1121 { 1122 TAPState *s = DO_UPCAST(TAPState, nc, nc); 1123 int ret; 1124 1125 if (s->enabled == 0) { 1126 return 0; 1127 } else { 1128 ret = tap_fd_disable(s->fd); 1129 if (ret == 0) { 1130 qemu_purge_queued_packets(nc); 1131 s->enabled = false; 1132 tap_update_fd_handler(s); 1133 } 1134 return ret; 1135 } 1136 } 1137