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