rfifolock: no need to get thread identifier when nesting
[qemu/ar7.git] / net / tap.c
blob740e8a26138cc4cf66a31de38304f620fd6ad38c
1 /*
2 * QEMU System Emulator
4 * Copyright (c) 2003-2008 Fabrice Bellard
5 * Copyright (c) 2009 Red Hat, Inc.
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:
14 * The above copyright notice and this permission notice shall be included in
15 * all copies or substantial portions of the Software.
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.
26 #include "qemu/osdep.h"
27 #include "tap_int.h"
30 #include <sys/ioctl.h>
31 #include <sys/wait.h>
32 #include <sys/socket.h>
33 #include <net/if.h>
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"
44 #include "net/tap.h"
46 #include "net/vhost_net.h"
48 typedef struct TAPState {
49 NetClientState nc;
50 int fd;
51 char down_script[1024];
52 char down_script_arg[128];
53 uint8_t buf[NET_BUFSIZE];
54 bool read_poll;
55 bool write_poll;
56 bool using_vnet_hdr;
57 bool has_ufo;
58 bool enabled;
59 VHostNetState *vhost_net;
60 unsigned host_vnet_hdr_len;
61 } TAPState;
63 static void launch_script(const char *setup_script, const char *ifname,
64 int fd, Error **errp);
66 static void tap_send(void *opaque);
67 static void tap_writable(void *opaque);
69 static void tap_update_fd_handler(TAPState *s)
71 qemu_set_fd_handler(s->fd,
72 s->read_poll && s->enabled ? tap_send : NULL,
73 s->write_poll && s->enabled ? tap_writable : NULL,
74 s);
77 static void tap_read_poll(TAPState *s, bool enable)
79 s->read_poll = enable;
80 tap_update_fd_handler(s);
83 static void tap_write_poll(TAPState *s, bool enable)
85 s->write_poll = enable;
86 tap_update_fd_handler(s);
89 static void tap_writable(void *opaque)
91 TAPState *s = opaque;
93 tap_write_poll(s, false);
95 qemu_flush_queued_packets(&s->nc);
98 static ssize_t tap_write_packet(TAPState *s, const struct iovec *iov, int iovcnt)
100 ssize_t len;
102 do {
103 len = writev(s->fd, iov, iovcnt);
104 } while (len == -1 && errno == EINTR);
106 if (len == -1 && errno == EAGAIN) {
107 tap_write_poll(s, true);
108 return 0;
111 return len;
114 static ssize_t tap_receive_iov(NetClientState *nc, const struct iovec *iov,
115 int iovcnt)
117 TAPState *s = DO_UPCAST(TAPState, nc, nc);
118 const struct iovec *iovp = iov;
119 struct iovec iov_copy[iovcnt + 1];
120 struct virtio_net_hdr_mrg_rxbuf hdr = { };
122 if (s->host_vnet_hdr_len && !s->using_vnet_hdr) {
123 iov_copy[0].iov_base = &hdr;
124 iov_copy[0].iov_len = s->host_vnet_hdr_len;
125 memcpy(&iov_copy[1], iov, iovcnt * sizeof(*iov));
126 iovp = iov_copy;
127 iovcnt++;
130 return tap_write_packet(s, iovp, iovcnt);
133 static ssize_t tap_receive_raw(NetClientState *nc, const uint8_t *buf, size_t size)
135 TAPState *s = DO_UPCAST(TAPState, nc, nc);
136 struct iovec iov[2];
137 int iovcnt = 0;
138 struct virtio_net_hdr_mrg_rxbuf hdr = { };
140 if (s->host_vnet_hdr_len) {
141 iov[iovcnt].iov_base = &hdr;
142 iov[iovcnt].iov_len = s->host_vnet_hdr_len;
143 iovcnt++;
146 iov[iovcnt].iov_base = (char *)buf;
147 iov[iovcnt].iov_len = size;
148 iovcnt++;
150 return tap_write_packet(s, iov, iovcnt);
153 static ssize_t tap_receive(NetClientState *nc, const uint8_t *buf, size_t size)
155 TAPState *s = DO_UPCAST(TAPState, nc, nc);
156 struct iovec iov[1];
158 if (s->host_vnet_hdr_len && !s->using_vnet_hdr) {
159 return tap_receive_raw(nc, buf, size);
162 iov[0].iov_base = (char *)buf;
163 iov[0].iov_len = size;
165 return tap_write_packet(s, iov, 1);
168 #ifndef __sun__
169 ssize_t tap_read_packet(int tapfd, uint8_t *buf, int maxlen)
171 return read(tapfd, buf, maxlen);
173 #endif
175 static void tap_send_completed(NetClientState *nc, ssize_t len)
177 TAPState *s = DO_UPCAST(TAPState, nc, nc);
178 tap_read_poll(s, true);
181 static void tap_send(void *opaque)
183 TAPState *s = opaque;
184 int size;
185 int packets = 0;
187 while (true) {
188 uint8_t *buf = s->buf;
190 size = tap_read_packet(s->fd, s->buf, sizeof(s->buf));
191 if (size <= 0) {
192 break;
195 if (s->host_vnet_hdr_len && !s->using_vnet_hdr) {
196 buf += s->host_vnet_hdr_len;
197 size -= s->host_vnet_hdr_len;
200 size = qemu_send_packet_async(&s->nc, buf, size, tap_send_completed);
201 if (size == 0) {
202 tap_read_poll(s, false);
203 break;
204 } else if (size < 0) {
205 break;
209 * When the host keeps receiving more packets while tap_send() is
210 * running we can hog the QEMU global mutex. Limit the number of
211 * packets that are processed per tap_send() callback to prevent
212 * stalling the guest.
214 packets++;
215 if (packets >= 50) {
216 break;
221 static bool tap_has_ufo(NetClientState *nc)
223 TAPState *s = DO_UPCAST(TAPState, nc, nc);
225 assert(nc->info->type == NET_CLIENT_OPTIONS_KIND_TAP);
227 return s->has_ufo;
230 static bool tap_has_vnet_hdr(NetClientState *nc)
232 TAPState *s = DO_UPCAST(TAPState, nc, nc);
234 assert(nc->info->type == NET_CLIENT_OPTIONS_KIND_TAP);
236 return !!s->host_vnet_hdr_len;
239 static bool tap_has_vnet_hdr_len(NetClientState *nc, int len)
241 TAPState *s = DO_UPCAST(TAPState, nc, nc);
243 assert(nc->info->type == NET_CLIENT_OPTIONS_KIND_TAP);
245 return !!tap_probe_vnet_hdr_len(s->fd, len);
248 static void tap_set_vnet_hdr_len(NetClientState *nc, int len)
250 TAPState *s = DO_UPCAST(TAPState, nc, nc);
252 assert(nc->info->type == NET_CLIENT_OPTIONS_KIND_TAP);
253 assert(len == sizeof(struct virtio_net_hdr_mrg_rxbuf) ||
254 len == sizeof(struct virtio_net_hdr));
256 tap_fd_set_vnet_hdr_len(s->fd, len);
257 s->host_vnet_hdr_len = len;
260 static void tap_using_vnet_hdr(NetClientState *nc, bool using_vnet_hdr)
262 TAPState *s = DO_UPCAST(TAPState, nc, nc);
264 assert(nc->info->type == NET_CLIENT_OPTIONS_KIND_TAP);
265 assert(!!s->host_vnet_hdr_len == using_vnet_hdr);
267 s->using_vnet_hdr = using_vnet_hdr;
270 static int tap_set_vnet_le(NetClientState *nc, bool is_le)
272 TAPState *s = DO_UPCAST(TAPState, nc, nc);
274 return tap_fd_set_vnet_le(s->fd, is_le);
277 static int tap_set_vnet_be(NetClientState *nc, bool is_be)
279 TAPState *s = DO_UPCAST(TAPState, nc, nc);
281 return tap_fd_set_vnet_be(s->fd, is_be);
284 static void tap_set_offload(NetClientState *nc, int csum, int tso4,
285 int tso6, int ecn, int ufo)
287 TAPState *s = DO_UPCAST(TAPState, nc, nc);
288 if (s->fd < 0) {
289 return;
292 tap_fd_set_offload(s->fd, csum, tso4, tso6, ecn, ufo);
295 static void tap_cleanup(NetClientState *nc)
297 TAPState *s = DO_UPCAST(TAPState, nc, nc);
298 Error *err = NULL;
300 if (s->vhost_net) {
301 vhost_net_cleanup(s->vhost_net);
302 s->vhost_net = NULL;
305 qemu_purge_queued_packets(nc);
307 if (s->down_script[0]) {
308 launch_script(s->down_script, s->down_script_arg, s->fd, &err);
309 if (err) {
310 error_report_err(err);
314 tap_read_poll(s, false);
315 tap_write_poll(s, false);
316 close(s->fd);
317 s->fd = -1;
320 static void tap_poll(NetClientState *nc, bool enable)
322 TAPState *s = DO_UPCAST(TAPState, nc, nc);
323 tap_read_poll(s, enable);
324 tap_write_poll(s, enable);
327 int tap_get_fd(NetClientState *nc)
329 TAPState *s = DO_UPCAST(TAPState, nc, nc);
330 assert(nc->info->type == NET_CLIENT_OPTIONS_KIND_TAP);
331 return s->fd;
334 /* fd support */
336 static NetClientInfo net_tap_info = {
337 .type = NET_CLIENT_OPTIONS_KIND_TAP,
338 .size = sizeof(TAPState),
339 .receive = tap_receive,
340 .receive_raw = tap_receive_raw,
341 .receive_iov = tap_receive_iov,
342 .poll = tap_poll,
343 .cleanup = tap_cleanup,
344 .has_ufo = tap_has_ufo,
345 .has_vnet_hdr = tap_has_vnet_hdr,
346 .has_vnet_hdr_len = tap_has_vnet_hdr_len,
347 .using_vnet_hdr = tap_using_vnet_hdr,
348 .set_offload = tap_set_offload,
349 .set_vnet_hdr_len = tap_set_vnet_hdr_len,
350 .set_vnet_le = tap_set_vnet_le,
351 .set_vnet_be = tap_set_vnet_be,
354 static TAPState *net_tap_fd_init(NetClientState *peer,
355 const char *model,
356 const char *name,
357 int fd,
358 int vnet_hdr)
360 NetClientState *nc;
361 TAPState *s;
363 nc = qemu_new_net_client(&net_tap_info, peer, model, name);
365 s = DO_UPCAST(TAPState, nc, nc);
367 s->fd = fd;
368 s->host_vnet_hdr_len = vnet_hdr ? sizeof(struct virtio_net_hdr) : 0;
369 s->using_vnet_hdr = false;
370 s->has_ufo = tap_probe_has_ufo(s->fd);
371 s->enabled = true;
372 tap_set_offload(&s->nc, 0, 0, 0, 0, 0);
374 * Make sure host header length is set correctly in tap:
375 * it might have been modified by another instance of qemu.
377 if (tap_probe_vnet_hdr_len(s->fd, s->host_vnet_hdr_len)) {
378 tap_fd_set_vnet_hdr_len(s->fd, s->host_vnet_hdr_len);
380 tap_read_poll(s, true);
381 s->vhost_net = NULL;
382 return s;
385 static void launch_script(const char *setup_script, const char *ifname,
386 int fd, Error **errp)
388 int pid, status;
389 char *args[3];
390 char **parg;
392 /* try to launch network script */
393 pid = fork();
394 if (pid < 0) {
395 error_setg_errno(errp, errno, "could not launch network script %s",
396 setup_script);
397 return;
399 if (pid == 0) {
400 int open_max = sysconf(_SC_OPEN_MAX), i;
402 for (i = 3; i < open_max; i++) {
403 if (i != fd) {
404 close(i);
407 parg = args;
408 *parg++ = (char *)setup_script;
409 *parg++ = (char *)ifname;
410 *parg = NULL;
411 execv(setup_script, args);
412 _exit(1);
413 } else {
414 while (waitpid(pid, &status, 0) != pid) {
415 /* loop */
418 if (WIFEXITED(status) && WEXITSTATUS(status) == 0) {
419 return;
421 error_setg(errp, "network script %s failed with status %d",
422 setup_script, status);
426 static int recv_fd(int c)
428 int fd;
429 uint8_t msgbuf[CMSG_SPACE(sizeof(fd))];
430 struct msghdr msg = {
431 .msg_control = msgbuf,
432 .msg_controllen = sizeof(msgbuf),
434 struct cmsghdr *cmsg;
435 struct iovec iov;
436 uint8_t req[1];
437 ssize_t len;
439 cmsg = CMSG_FIRSTHDR(&msg);
440 cmsg->cmsg_level = SOL_SOCKET;
441 cmsg->cmsg_type = SCM_RIGHTS;
442 cmsg->cmsg_len = CMSG_LEN(sizeof(fd));
443 msg.msg_controllen = cmsg->cmsg_len;
445 iov.iov_base = req;
446 iov.iov_len = sizeof(req);
448 msg.msg_iov = &iov;
449 msg.msg_iovlen = 1;
451 len = recvmsg(c, &msg, 0);
452 if (len > 0) {
453 memcpy(&fd, CMSG_DATA(cmsg), sizeof(fd));
454 return fd;
457 return len;
460 static int net_bridge_run_helper(const char *helper, const char *bridge,
461 Error **errp)
463 sigset_t oldmask, mask;
464 int pid, status;
465 char *args[5];
466 char **parg;
467 int sv[2];
469 sigemptyset(&mask);
470 sigaddset(&mask, SIGCHLD);
471 sigprocmask(SIG_BLOCK, &mask, &oldmask);
473 if (socketpair(PF_UNIX, SOCK_STREAM, 0, sv) == -1) {
474 error_setg_errno(errp, errno, "socketpair() failed");
475 return -1;
478 /* try to launch bridge helper */
479 pid = fork();
480 if (pid < 0) {
481 error_setg_errno(errp, errno, "Can't fork bridge helper");
482 return -1;
484 if (pid == 0) {
485 int open_max = sysconf(_SC_OPEN_MAX), i;
486 char fd_buf[6+10];
487 char br_buf[6+IFNAMSIZ] = {0};
488 char helper_cmd[PATH_MAX + sizeof(fd_buf) + sizeof(br_buf) + 15];
490 for (i = 3; i < open_max; i++) {
491 if (i != sv[1]) {
492 close(i);
496 snprintf(fd_buf, sizeof(fd_buf), "%s%d", "--fd=", sv[1]);
498 if (strrchr(helper, ' ') || strrchr(helper, '\t')) {
499 /* assume helper is a command */
501 if (strstr(helper, "--br=") == NULL) {
502 snprintf(br_buf, sizeof(br_buf), "%s%s", "--br=", bridge);
505 snprintf(helper_cmd, sizeof(helper_cmd), "%s %s %s %s",
506 helper, "--use-vnet", fd_buf, br_buf);
508 parg = args;
509 *parg++ = (char *)"sh";
510 *parg++ = (char *)"-c";
511 *parg++ = helper_cmd;
512 *parg++ = NULL;
514 execv("/bin/sh", args);
515 } else {
516 /* assume helper is just the executable path name */
518 snprintf(br_buf, sizeof(br_buf), "%s%s", "--br=", bridge);
520 parg = args;
521 *parg++ = (char *)helper;
522 *parg++ = (char *)"--use-vnet";
523 *parg++ = fd_buf;
524 *parg++ = br_buf;
525 *parg++ = NULL;
527 execv(helper, args);
529 _exit(1);
531 } else {
532 int fd;
533 int saved_errno;
535 close(sv[1]);
537 do {
538 fd = recv_fd(sv[0]);
539 } while (fd == -1 && errno == EINTR);
540 saved_errno = errno;
542 close(sv[0]);
544 while (waitpid(pid, &status, 0) != pid) {
545 /* loop */
547 sigprocmask(SIG_SETMASK, &oldmask, NULL);
548 if (fd < 0) {
549 error_setg_errno(errp, saved_errno,
550 "failed to recv file descriptor");
551 return -1;
553 if (!WIFEXITED(status) || WEXITSTATUS(status) != 0) {
554 error_setg(errp, "bridge helper failed");
555 return -1;
557 return fd;
561 int net_init_bridge(const NetClientOptions *opts, const char *name,
562 NetClientState *peer, Error **errp)
564 const NetdevBridgeOptions *bridge;
565 const char *helper, *br;
566 TAPState *s;
567 int fd, vnet_hdr;
569 assert(opts->type == NET_CLIENT_OPTIONS_KIND_BRIDGE);
570 bridge = opts->u.bridge.data;
572 helper = bridge->has_helper ? bridge->helper : DEFAULT_BRIDGE_HELPER;
573 br = bridge->has_br ? bridge->br : DEFAULT_BRIDGE_INTERFACE;
575 fd = net_bridge_run_helper(helper, br, errp);
576 if (fd == -1) {
577 return -1;
580 fcntl(fd, F_SETFL, O_NONBLOCK);
581 vnet_hdr = tap_probe_vnet_hdr(fd);
582 s = net_tap_fd_init(peer, "bridge", name, fd, vnet_hdr);
584 snprintf(s->nc.info_str, sizeof(s->nc.info_str), "helper=%s,br=%s", helper,
585 br);
587 return 0;
590 static int net_tap_init(const NetdevTapOptions *tap, int *vnet_hdr,
591 const char *setup_script, char *ifname,
592 size_t ifname_sz, int mq_required, Error **errp)
594 Error *err = NULL;
595 int fd, vnet_hdr_required;
597 if (tap->has_vnet_hdr) {
598 *vnet_hdr = tap->vnet_hdr;
599 vnet_hdr_required = *vnet_hdr;
600 } else {
601 *vnet_hdr = 1;
602 vnet_hdr_required = 0;
605 TFR(fd = tap_open(ifname, ifname_sz, vnet_hdr, vnet_hdr_required,
606 mq_required, errp));
607 if (fd < 0) {
608 return -1;
611 if (setup_script &&
612 setup_script[0] != '\0' &&
613 strcmp(setup_script, "no") != 0) {
614 launch_script(setup_script, ifname, fd, &err);
615 if (err) {
616 error_propagate(errp, err);
617 close(fd);
618 return -1;
622 return fd;
625 #define MAX_TAP_QUEUES 1024
627 static void net_init_tap_one(const NetdevTapOptions *tap, NetClientState *peer,
628 const char *model, const char *name,
629 const char *ifname, const char *script,
630 const char *downscript, const char *vhostfdname,
631 int vnet_hdr, int fd, Error **errp)
633 Error *err = NULL;
634 TAPState *s = net_tap_fd_init(peer, model, name, fd, vnet_hdr);
635 int vhostfd;
637 tap_set_sndbuf(s->fd, tap, &err);
638 if (err) {
639 error_propagate(errp, err);
640 return;
643 if (tap->has_fd || tap->has_fds) {
644 snprintf(s->nc.info_str, sizeof(s->nc.info_str), "fd=%d", fd);
645 } else if (tap->has_helper) {
646 snprintf(s->nc.info_str, sizeof(s->nc.info_str), "helper=%s",
647 tap->helper);
648 } else {
649 snprintf(s->nc.info_str, sizeof(s->nc.info_str),
650 "ifname=%s,script=%s,downscript=%s", ifname, script,
651 downscript);
653 if (strcmp(downscript, "no") != 0) {
654 snprintf(s->down_script, sizeof(s->down_script), "%s", downscript);
655 snprintf(s->down_script_arg, sizeof(s->down_script_arg),
656 "%s", ifname);
660 if (tap->has_vhost ? tap->vhost :
661 vhostfdname || (tap->has_vhostforce && tap->vhostforce)) {
662 VhostNetOptions options;
664 options.backend_type = VHOST_BACKEND_TYPE_KERNEL;
665 options.net_backend = &s->nc;
667 if (vhostfdname) {
668 vhostfd = monitor_fd_param(cur_mon, vhostfdname, &err);
669 if (vhostfd == -1) {
670 error_propagate(errp, err);
671 return;
673 } else {
674 vhostfd = open("/dev/vhost-net", O_RDWR);
675 if (vhostfd < 0) {
676 error_setg_errno(errp, errno,
677 "tap: open vhost char device failed");
678 return;
681 options.opaque = (void *)(uintptr_t)vhostfd;
683 s->vhost_net = vhost_net_init(&options);
684 if (!s->vhost_net) {
685 error_setg(errp,
686 "vhost-net requested but could not be initialized");
687 return;
689 } else if (vhostfdname) {
690 error_setg(errp, "vhostfd= is not valid without vhost");
694 static int get_fds(char *str, char *fds[], int max)
696 char *ptr = str, *this;
697 size_t len = strlen(str);
698 int i = 0;
700 while (i < max && ptr < str + len) {
701 this = strchr(ptr, ':');
703 if (this == NULL) {
704 fds[i] = g_strdup(ptr);
705 } else {
706 fds[i] = g_strndup(ptr, this - ptr);
709 i++;
710 if (this == NULL) {
711 break;
712 } else {
713 ptr = this + 1;
717 return i;
720 int net_init_tap(const NetClientOptions *opts, const char *name,
721 NetClientState *peer, Error **errp)
723 const NetdevTapOptions *tap;
724 int fd, vnet_hdr = 0, i = 0, queues;
725 /* for the no-fd, no-helper case */
726 const char *script = NULL; /* suppress wrong "uninit'd use" gcc warning */
727 const char *downscript = NULL;
728 Error *err = NULL;
729 const char *vhostfdname;
730 char ifname[128];
732 assert(opts->type == NET_CLIENT_OPTIONS_KIND_TAP);
733 tap = opts->u.tap.data;
734 queues = tap->has_queues ? tap->queues : 1;
735 vhostfdname = tap->has_vhostfd ? tap->vhostfd : NULL;
737 /* QEMU vlans does not support multiqueue tap, in this case peer is set.
738 * For -netdev, peer is always NULL. */
739 if (peer && (tap->has_queues || tap->has_fds || tap->has_vhostfds)) {
740 error_setg(errp, "Multiqueue tap cannot be used with QEMU vlans");
741 return -1;
744 if (tap->has_fd) {
745 if (tap->has_ifname || tap->has_script || tap->has_downscript ||
746 tap->has_vnet_hdr || tap->has_helper || tap->has_queues ||
747 tap->has_fds || tap->has_vhostfds) {
748 error_setg(errp, "ifname=, script=, downscript=, vnet_hdr=, "
749 "helper=, queues=, fds=, and vhostfds= "
750 "are invalid with fd=");
751 return -1;
754 fd = monitor_fd_param(cur_mon, tap->fd, &err);
755 if (fd == -1) {
756 error_propagate(errp, err);
757 return -1;
760 fcntl(fd, F_SETFL, O_NONBLOCK);
762 vnet_hdr = tap_probe_vnet_hdr(fd);
764 net_init_tap_one(tap, peer, "tap", name, NULL,
765 script, downscript,
766 vhostfdname, vnet_hdr, fd, &err);
767 if (err) {
768 error_propagate(errp, err);
769 return -1;
771 } else if (tap->has_fds) {
772 char *fds[MAX_TAP_QUEUES];
773 char *vhost_fds[MAX_TAP_QUEUES];
774 int nfds, nvhosts;
776 if (tap->has_ifname || tap->has_script || tap->has_downscript ||
777 tap->has_vnet_hdr || tap->has_helper || tap->has_queues ||
778 tap->has_vhostfd) {
779 error_setg(errp, "ifname=, script=, downscript=, vnet_hdr=, "
780 "helper=, queues=, and vhostfd= "
781 "are invalid with fds=");
782 return -1;
785 nfds = get_fds(tap->fds, fds, MAX_TAP_QUEUES);
786 if (tap->has_vhostfds) {
787 nvhosts = get_fds(tap->vhostfds, vhost_fds, MAX_TAP_QUEUES);
788 if (nfds != nvhosts) {
789 error_setg(errp, "The number of fds passed does not match "
790 "the number of vhostfds passed");
791 return -1;
795 for (i = 0; i < nfds; i++) {
796 fd = monitor_fd_param(cur_mon, fds[i], &err);
797 if (fd == -1) {
798 error_propagate(errp, err);
799 return -1;
802 fcntl(fd, F_SETFL, O_NONBLOCK);
804 if (i == 0) {
805 vnet_hdr = tap_probe_vnet_hdr(fd);
806 } else if (vnet_hdr != tap_probe_vnet_hdr(fd)) {
807 error_setg(errp,
808 "vnet_hdr not consistent across given tap fds");
809 return -1;
812 net_init_tap_one(tap, peer, "tap", name, ifname,
813 script, downscript,
814 tap->has_vhostfds ? vhost_fds[i] : NULL,
815 vnet_hdr, fd, &err);
816 if (err) {
817 error_propagate(errp, err);
818 return -1;
821 } else if (tap->has_helper) {
822 if (tap->has_ifname || tap->has_script || tap->has_downscript ||
823 tap->has_vnet_hdr || tap->has_queues || tap->has_vhostfds) {
824 error_setg(errp, "ifname=, script=, downscript=, vnet_hdr=, "
825 "queues=, and vhostfds= are invalid with helper=");
826 return -1;
829 fd = net_bridge_run_helper(tap->helper, DEFAULT_BRIDGE_INTERFACE,
830 errp);
831 if (fd == -1) {
832 return -1;
835 fcntl(fd, F_SETFL, O_NONBLOCK);
836 vnet_hdr = tap_probe_vnet_hdr(fd);
838 net_init_tap_one(tap, peer, "bridge", name, ifname,
839 script, downscript, vhostfdname,
840 vnet_hdr, fd, &err);
841 if (err) {
842 error_propagate(errp, err);
843 close(fd);
844 return -1;
846 } else {
847 if (tap->has_vhostfds) {
848 error_setg(errp, "vhostfds= is invalid if fds= wasn't specified");
849 return -1;
851 script = tap->has_script ? tap->script : DEFAULT_NETWORK_SCRIPT;
852 downscript = tap->has_downscript ? tap->downscript :
853 DEFAULT_NETWORK_DOWN_SCRIPT;
855 if (tap->has_ifname) {
856 pstrcpy(ifname, sizeof ifname, tap->ifname);
857 } else {
858 ifname[0] = '\0';
861 for (i = 0; i < queues; i++) {
862 fd = net_tap_init(tap, &vnet_hdr, i >= 1 ? "no" : script,
863 ifname, sizeof ifname, queues > 1, errp);
864 if (fd == -1) {
865 return -1;
868 if (queues > 1 && i == 0 && !tap->has_ifname) {
869 if (tap_fd_get_ifname(fd, ifname)) {
870 error_setg(errp, "Fail to get ifname");
871 close(fd);
872 return -1;
876 net_init_tap_one(tap, peer, "tap", name, ifname,
877 i >= 1 ? "no" : script,
878 i >= 1 ? "no" : downscript,
879 vhostfdname, vnet_hdr, fd, &err);
880 if (err) {
881 error_propagate(errp, err);
882 close(fd);
883 return -1;
888 return 0;
891 VHostNetState *tap_get_vhost_net(NetClientState *nc)
893 TAPState *s = DO_UPCAST(TAPState, nc, nc);
894 assert(nc->info->type == NET_CLIENT_OPTIONS_KIND_TAP);
895 return s->vhost_net;
898 int tap_enable(NetClientState *nc)
900 TAPState *s = DO_UPCAST(TAPState, nc, nc);
901 int ret;
903 if (s->enabled) {
904 return 0;
905 } else {
906 ret = tap_fd_enable(s->fd);
907 if (ret == 0) {
908 s->enabled = true;
909 tap_update_fd_handler(s);
911 return ret;
915 int tap_disable(NetClientState *nc)
917 TAPState *s = DO_UPCAST(TAPState, nc, nc);
918 int ret;
920 if (s->enabled == 0) {
921 return 0;
922 } else {
923 ret = tap_fd_disable(s->fd);
924 if (ret == 0) {
925 qemu_purge_queued_packets(nc);
926 s->enabled = false;
927 tap_update_fd_handler(s);
929 return ret;