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