Merge remote-tracking branch 'remotes/pmaydell/tags/pull-target-arm-20200804' into...
[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/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 int pid, status;
482 char *args[5];
483 char **parg;
484 int sv[2];
485
486 sigemptyset(&mask);
487 sigaddset(&mask, SIGCHLD);
488 sigprocmask(SIG_BLOCK, &mask, &oldmask);
489
490 if (socketpair(PF_UNIX, SOCK_STREAM, 0, sv) == -1) {
491 error_setg_errno(errp, errno, "socketpair() failed");
492 return -1;
493 }
494
495 /* try to launch bridge helper */
496 pid = fork();
497 if (pid < 0) {
498 error_setg_errno(errp, errno, "Can't fork bridge helper");
499 return -1;
500 }
501 if (pid == 0) {
502 int open_max = sysconf(_SC_OPEN_MAX), i;
503 char *fd_buf = NULL;
504 char *br_buf = NULL;
505 char *helper_cmd = NULL;
506
507 for (i = 3; i < open_max; i++) {
508 if (i != sv[1]) {
509 close(i);
510 }
511 }
512
513 fd_buf = g_strdup_printf("%s%d", "--fd=", sv[1]);
514
515 if (strrchr(helper, ' ') || strrchr(helper, '\t')) {
516 /* assume helper is a command */
517
518 if (strstr(helper, "--br=") == NULL) {
519 br_buf = g_strdup_printf("%s%s", "--br=", bridge);
520 }
521
522 helper_cmd = g_strdup_printf("%s %s %s %s", helper,
523 "--use-vnet", fd_buf, br_buf ? br_buf : "");
524
525 parg = args;
526 *parg++ = (char *)"sh";
527 *parg++ = (char *)"-c";
528 *parg++ = helper_cmd;
529 *parg++ = NULL;
530
531 execv("/bin/sh", args);
532 g_free(helper_cmd);
533 } else {
534 /* assume helper is just the executable path name */
535
536 br_buf = g_strdup_printf("%s%s", "--br=", bridge);
537
538 parg = args;
539 *parg++ = (char *)helper;
540 *parg++ = (char *)"--use-vnet";
541 *parg++ = fd_buf;
542 *parg++ = br_buf;
543 *parg++ = NULL;
544
545 execv(helper, args);
546 }
547 g_free(fd_buf);
548 g_free(br_buf);
549 _exit(1);
550
551 } else {
552 int fd;
553 int saved_errno;
554
555 close(sv[1]);
556
557 do {
558 fd = recv_fd(sv[0]);
559 } while (fd == -1 && errno == EINTR);
560 saved_errno = errno;
561
562 close(sv[0]);
563
564 while (waitpid(pid, &status, 0) != pid) {
565 /* loop */
566 }
567 sigprocmask(SIG_SETMASK, &oldmask, NULL);
568 if (fd < 0) {
569 error_setg_errno(errp, saved_errno,
570 "failed to recv file descriptor");
571 return -1;
572 }
573 if (!WIFEXITED(status) || WEXITSTATUS(status) != 0) {
574 error_setg(errp, "bridge helper failed");
575 return -1;
576 }
577 return fd;
578 }
579 }
580
581 int net_init_bridge(const Netdev *netdev, const char *name,
582 NetClientState *peer, Error **errp)
583 {
584 const NetdevBridgeOptions *bridge;
585 const char *helper, *br;
586 TAPState *s;
587 int fd, vnet_hdr;
588
589 assert(netdev->type == NET_CLIENT_DRIVER_BRIDGE);
590 bridge = &netdev->u.bridge;
591
592 helper = bridge->has_helper ? bridge->helper : DEFAULT_BRIDGE_HELPER;
593 br = bridge->has_br ? bridge->br : DEFAULT_BRIDGE_INTERFACE;
594
595 fd = net_bridge_run_helper(helper, br, errp);
596 if (fd == -1) {
597 return -1;
598 }
599
600 qemu_set_nonblock(fd);
601 vnet_hdr = tap_probe_vnet_hdr(fd, errp);
602 if (vnet_hdr < 0) {
603 close(fd);
604 return -1;
605 }
606 s = net_tap_fd_init(peer, "bridge", name, fd, vnet_hdr);
607
608 snprintf(s->nc.info_str, sizeof(s->nc.info_str), "helper=%s,br=%s", helper,
609 br);
610
611 return 0;
612 }
613
614 static int net_tap_init(const NetdevTapOptions *tap, int *vnet_hdr,
615 const char *setup_script, char *ifname,
616 size_t ifname_sz, int mq_required, Error **errp)
617 {
618 Error *err = NULL;
619 int fd, vnet_hdr_required;
620
621 if (tap->has_vnet_hdr) {
622 *vnet_hdr = tap->vnet_hdr;
623 vnet_hdr_required = *vnet_hdr;
624 } else {
625 *vnet_hdr = 1;
626 vnet_hdr_required = 0;
627 }
628
629 TFR(fd = tap_open(ifname, ifname_sz, vnet_hdr, vnet_hdr_required,
630 mq_required, errp));
631 if (fd < 0) {
632 return -1;
633 }
634
635 if (setup_script &&
636 setup_script[0] != '\0' &&
637 strcmp(setup_script, "no") != 0) {
638 launch_script(setup_script, ifname, fd, &err);
639 if (err) {
640 error_propagate(errp, err);
641 close(fd);
642 return -1;
643 }
644 }
645
646 return fd;
647 }
648
649 #define MAX_TAP_QUEUES 1024
650
651 static void net_init_tap_one(const NetdevTapOptions *tap, NetClientState *peer,
652 const char *model, const char *name,
653 const char *ifname, const char *script,
654 const char *downscript, const char *vhostfdname,
655 int vnet_hdr, int fd, Error **errp)
656 {
657 Error *err = NULL;
658 TAPState *s = net_tap_fd_init(peer, model, name, fd, vnet_hdr);
659 int vhostfd;
660
661 tap_set_sndbuf(s->fd, tap, &err);
662 if (err) {
663 error_propagate(errp, err);
664 return;
665 }
666
667 if (tap->has_fd || tap->has_fds) {
668 snprintf(s->nc.info_str, sizeof(s->nc.info_str), "fd=%d", fd);
669 } else if (tap->has_helper) {
670 snprintf(s->nc.info_str, sizeof(s->nc.info_str), "helper=%s",
671 tap->helper);
672 } else {
673 snprintf(s->nc.info_str, sizeof(s->nc.info_str),
674 "ifname=%s,script=%s,downscript=%s", ifname, script,
675 downscript);
676
677 if (strcmp(downscript, "no") != 0) {
678 snprintf(s->down_script, sizeof(s->down_script), "%s", downscript);
679 snprintf(s->down_script_arg, sizeof(s->down_script_arg),
680 "%s", ifname);
681 }
682 }
683
684 if (tap->has_vhost ? tap->vhost :
685 vhostfdname || (tap->has_vhostforce && tap->vhostforce)) {
686 VhostNetOptions options;
687
688 options.backend_type = VHOST_BACKEND_TYPE_KERNEL;
689 options.net_backend = &s->nc;
690 if (tap->has_poll_us) {
691 options.busyloop_timeout = tap->poll_us;
692 } else {
693 options.busyloop_timeout = 0;
694 }
695
696 if (vhostfdname) {
697 int ret;
698
699 vhostfd = monitor_fd_param(cur_mon, vhostfdname, &err);
700 if (vhostfd == -1) {
701 if (tap->has_vhostforce && tap->vhostforce) {
702 error_propagate(errp, err);
703 } else {
704 warn_report_err(err);
705 }
706 return;
707 }
708 ret = qemu_try_set_nonblock(vhostfd);
709 if (ret < 0) {
710 error_setg_errno(errp, -ret, "%s: Can't use file descriptor %d",
711 name, fd);
712 return;
713 }
714 } else {
715 vhostfd = open("/dev/vhost-net", O_RDWR);
716 if (vhostfd < 0) {
717 if (tap->has_vhostforce && tap->vhostforce) {
718 error_setg_errno(errp, errno,
719 "tap: open vhost char device failed");
720 } else {
721 warn_report("tap: open vhost char device failed: %s",
722 strerror(errno));
723 }
724 return;
725 }
726 qemu_set_nonblock(vhostfd);
727 }
728 options.opaque = (void *)(uintptr_t)vhostfd;
729
730 s->vhost_net = vhost_net_init(&options);
731 if (!s->vhost_net) {
732 if (tap->has_vhostforce && tap->vhostforce) {
733 error_setg(errp, VHOST_NET_INIT_FAILED);
734 } else {
735 warn_report(VHOST_NET_INIT_FAILED);
736 }
737 return;
738 }
739 } else if (vhostfdname) {
740 error_setg(errp, "vhostfd(s)= is not valid without vhost");
741 }
742 }
743
744 static int get_fds(char *str, char *fds[], int max)
745 {
746 char *ptr = str, *this;
747 size_t len = strlen(str);
748 int i = 0;
749
750 while (i < max && ptr < str + len) {
751 this = strchr(ptr, ':');
752
753 if (this == NULL) {
754 fds[i] = g_strdup(ptr);
755 } else {
756 fds[i] = g_strndup(ptr, this - ptr);
757 }
758
759 i++;
760 if (this == NULL) {
761 break;
762 } else {
763 ptr = this + 1;
764 }
765 }
766
767 return i;
768 }
769
770 int net_init_tap(const Netdev *netdev, const char *name,
771 NetClientState *peer, Error **errp)
772 {
773 const NetdevTapOptions *tap;
774 int fd, vnet_hdr = 0, i = 0, queues;
775 /* for the no-fd, no-helper case */
776 const char *script = NULL; /* suppress wrong "uninit'd use" gcc warning */
777 const char *downscript = NULL;
778 Error *err = NULL;
779 const char *vhostfdname;
780 char ifname[128];
781 int ret = 0;
782
783 assert(netdev->type == NET_CLIENT_DRIVER_TAP);
784 tap = &netdev->u.tap;
785 queues = tap->has_queues ? tap->queues : 1;
786 vhostfdname = tap->has_vhostfd ? tap->vhostfd : NULL;
787
788 /* QEMU hubs do not support multiqueue tap, in this case peer is set.
789 * For -netdev, peer is always NULL. */
790 if (peer && (tap->has_queues || tap->has_fds || tap->has_vhostfds)) {
791 error_setg(errp, "Multiqueue tap cannot be used with hubs");
792 return -1;
793 }
794
795 if (tap->has_fd) {
796 if (tap->has_ifname || tap->has_script || tap->has_downscript ||
797 tap->has_vnet_hdr || tap->has_helper || tap->has_queues ||
798 tap->has_fds || tap->has_vhostfds) {
799 error_setg(errp, "ifname=, script=, downscript=, vnet_hdr=, "
800 "helper=, queues=, fds=, and vhostfds= "
801 "are invalid with fd=");
802 return -1;
803 }
804
805 fd = monitor_fd_param(cur_mon, tap->fd, errp);
806 if (fd == -1) {
807 return -1;
808 }
809
810 ret = qemu_try_set_nonblock(fd);
811 if (ret < 0) {
812 error_setg_errno(errp, -ret, "%s: Can't use file descriptor %d",
813 name, fd);
814 return -1;
815 }
816
817 vnet_hdr = tap_probe_vnet_hdr(fd, errp);
818 if (vnet_hdr < 0) {
819 close(fd);
820 return -1;
821 }
822
823 net_init_tap_one(tap, peer, "tap", name, NULL,
824 script, downscript,
825 vhostfdname, vnet_hdr, fd, &err);
826 if (err) {
827 error_propagate(errp, err);
828 return -1;
829 }
830 } else if (tap->has_fds) {
831 char **fds;
832 char **vhost_fds;
833 int nfds = 0, nvhosts = 0;
834
835 if (tap->has_ifname || tap->has_script || tap->has_downscript ||
836 tap->has_vnet_hdr || tap->has_helper || tap->has_queues ||
837 tap->has_vhostfd) {
838 error_setg(errp, "ifname=, script=, downscript=, vnet_hdr=, "
839 "helper=, queues=, and vhostfd= "
840 "are invalid with fds=");
841 return -1;
842 }
843
844 fds = g_new0(char *, MAX_TAP_QUEUES);
845 vhost_fds = g_new0(char *, MAX_TAP_QUEUES);
846
847 nfds = get_fds(tap->fds, fds, MAX_TAP_QUEUES);
848 if (tap->has_vhostfds) {
849 nvhosts = get_fds(tap->vhostfds, vhost_fds, MAX_TAP_QUEUES);
850 if (nfds != nvhosts) {
851 error_setg(errp, "The number of fds passed does not match "
852 "the number of vhostfds passed");
853 ret = -1;
854 goto free_fail;
855 }
856 }
857
858 for (i = 0; i < nfds; i++) {
859 fd = monitor_fd_param(cur_mon, fds[i], errp);
860 if (fd == -1) {
861 ret = -1;
862 goto free_fail;
863 }
864
865 ret = qemu_try_set_nonblock(fd);
866 if (ret < 0) {
867 error_setg_errno(errp, -ret, "%s: Can't use file descriptor %d",
868 name, fd);
869 goto free_fail;
870 }
871
872 if (i == 0) {
873 vnet_hdr = tap_probe_vnet_hdr(fd, errp);
874 if (vnet_hdr < 0) {
875 goto free_fail;
876 }
877 } else if (vnet_hdr != tap_probe_vnet_hdr(fd, NULL)) {
878 error_setg(errp,
879 "vnet_hdr not consistent across given tap fds");
880 ret = -1;
881 goto free_fail;
882 }
883
884 net_init_tap_one(tap, peer, "tap", name, ifname,
885 script, downscript,
886 tap->has_vhostfds ? vhost_fds[i] : NULL,
887 vnet_hdr, fd, &err);
888 if (err) {
889 error_propagate(errp, err);
890 ret = -1;
891 goto free_fail;
892 }
893 }
894
895 free_fail:
896 for (i = 0; i < nvhosts; i++) {
897 g_free(vhost_fds[i]);
898 }
899 for (i = 0; i < nfds; i++) {
900 g_free(fds[i]);
901 }
902 g_free(fds);
903 g_free(vhost_fds);
904 return ret;
905 } else if (tap->has_helper) {
906 if (tap->has_ifname || tap->has_script || tap->has_downscript ||
907 tap->has_vnet_hdr || tap->has_queues || tap->has_vhostfds) {
908 error_setg(errp, "ifname=, script=, downscript=, vnet_hdr=, "
909 "queues=, and vhostfds= are invalid with helper=");
910 return -1;
911 }
912
913 fd = net_bridge_run_helper(tap->helper,
914 tap->has_br ?
915 tap->br : DEFAULT_BRIDGE_INTERFACE,
916 errp);
917 if (fd == -1) {
918 return -1;
919 }
920
921 qemu_set_nonblock(fd);
922 vnet_hdr = tap_probe_vnet_hdr(fd, errp);
923 if (vnet_hdr < 0) {
924 close(fd);
925 return -1;
926 }
927
928 net_init_tap_one(tap, peer, "bridge", name, ifname,
929 script, downscript, vhostfdname,
930 vnet_hdr, fd, &err);
931 if (err) {
932 error_propagate(errp, err);
933 close(fd);
934 return -1;
935 }
936 } else {
937 if (tap->has_vhostfds) {
938 error_setg(errp, "vhostfds= is invalid if fds= wasn't specified");
939 return -1;
940 }
941 script = tap->has_script ? tap->script : DEFAULT_NETWORK_SCRIPT;
942 downscript = tap->has_downscript ? tap->downscript :
943 DEFAULT_NETWORK_DOWN_SCRIPT;
944
945 if (tap->has_ifname) {
946 pstrcpy(ifname, sizeof ifname, tap->ifname);
947 } else {
948 ifname[0] = '\0';
949 }
950
951 for (i = 0; i < queues; i++) {
952 fd = net_tap_init(tap, &vnet_hdr, i >= 1 ? "no" : script,
953 ifname, sizeof ifname, queues > 1, errp);
954 if (fd == -1) {
955 return -1;
956 }
957
958 if (queues > 1 && i == 0 && !tap->has_ifname) {
959 if (tap_fd_get_ifname(fd, ifname)) {
960 error_setg(errp, "Fail to get ifname");
961 close(fd);
962 return -1;
963 }
964 }
965
966 net_init_tap_one(tap, peer, "tap", name, ifname,
967 i >= 1 ? "no" : script,
968 i >= 1 ? "no" : downscript,
969 vhostfdname, vnet_hdr, fd, &err);
970 if (err) {
971 error_propagate(errp, err);
972 close(fd);
973 return -1;
974 }
975 }
976 }
977
978 return 0;
979 }
980
981 VHostNetState *tap_get_vhost_net(NetClientState *nc)
982 {
983 TAPState *s = DO_UPCAST(TAPState, nc, nc);
984 assert(nc->info->type == NET_CLIENT_DRIVER_TAP);
985 return s->vhost_net;
986 }
987
988 int tap_enable(NetClientState *nc)
989 {
990 TAPState *s = DO_UPCAST(TAPState, nc, nc);
991 int ret;
992
993 if (s->enabled) {
994 return 0;
995 } else {
996 ret = tap_fd_enable(s->fd);
997 if (ret == 0) {
998 s->enabled = true;
999 tap_update_fd_handler(s);
1000 }
1001 return ret;
1002 }
1003 }
1004
1005 int tap_disable(NetClientState *nc)
1006 {
1007 TAPState *s = DO_UPCAST(TAPState, nc, nc);
1008 int ret;
1009
1010 if (s->enabled == 0) {
1011 return 0;
1012 } else {
1013 ret = tap_fd_disable(s->fd);
1014 if (ret == 0) {
1015 qemu_purge_queued_packets(nc);
1016 s->enabled = false;
1017 tap_update_fd_handler(s);
1018 }
1019 return ret;
1020 }
1021 }