Merge remote-tracking branch 'remotes/aperard/tags/pull-xen-20200407' 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/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
259 tap_fd_set_vnet_hdr_len(s->fd, len);
260 s->host_vnet_hdr_len = len;
261 }
262
263 static void tap_using_vnet_hdr(NetClientState *nc, bool using_vnet_hdr)
264 {
265 TAPState *s = DO_UPCAST(TAPState, nc, nc);
266
267 assert(nc->info->type == NET_CLIENT_DRIVER_TAP);
268 assert(!!s->host_vnet_hdr_len == using_vnet_hdr);
269
270 s->using_vnet_hdr = using_vnet_hdr;
271 }
272
273 static int tap_set_vnet_le(NetClientState *nc, bool is_le)
274 {
275 TAPState *s = DO_UPCAST(TAPState, nc, nc);
276
277 return tap_fd_set_vnet_le(s->fd, is_le);
278 }
279
280 static int tap_set_vnet_be(NetClientState *nc, bool is_be)
281 {
282 TAPState *s = DO_UPCAST(TAPState, nc, nc);
283
284 return tap_fd_set_vnet_be(s->fd, is_be);
285 }
286
287 static void tap_set_offload(NetClientState *nc, int csum, int tso4,
288 int tso6, int ecn, int ufo)
289 {
290 TAPState *s = DO_UPCAST(TAPState, nc, nc);
291 if (s->fd < 0) {
292 return;
293 }
294
295 tap_fd_set_offload(s->fd, csum, tso4, tso6, ecn, ufo);
296 }
297
298 static void tap_exit_notify(Notifier *notifier, void *data)
299 {
300 TAPState *s = container_of(notifier, TAPState, exit);
301 Error *err = NULL;
302
303 if (s->down_script[0]) {
304 launch_script(s->down_script, s->down_script_arg, s->fd, &err);
305 if (err) {
306 error_report_err(err);
307 }
308 }
309 }
310
311 static void tap_cleanup(NetClientState *nc)
312 {
313 TAPState *s = DO_UPCAST(TAPState, nc, nc);
314
315 if (s->vhost_net) {
316 vhost_net_cleanup(s->vhost_net);
317 g_free(s->vhost_net);
318 s->vhost_net = NULL;
319 }
320
321 qemu_purge_queued_packets(nc);
322
323 tap_exit_notify(&s->exit, NULL);
324 qemu_remove_exit_notifier(&s->exit);
325
326 tap_read_poll(s, false);
327 tap_write_poll(s, false);
328 close(s->fd);
329 s->fd = -1;
330 }
331
332 static void tap_poll(NetClientState *nc, bool enable)
333 {
334 TAPState *s = DO_UPCAST(TAPState, nc, nc);
335 tap_read_poll(s, enable);
336 tap_write_poll(s, enable);
337 }
338
339 int tap_get_fd(NetClientState *nc)
340 {
341 TAPState *s = DO_UPCAST(TAPState, nc, nc);
342 assert(nc->info->type == NET_CLIENT_DRIVER_TAP);
343 return s->fd;
344 }
345
346 /* fd support */
347
348 static NetClientInfo net_tap_info = {
349 .type = NET_CLIENT_DRIVER_TAP,
350 .size = sizeof(TAPState),
351 .receive = tap_receive,
352 .receive_raw = tap_receive_raw,
353 .receive_iov = tap_receive_iov,
354 .poll = tap_poll,
355 .cleanup = tap_cleanup,
356 .has_ufo = tap_has_ufo,
357 .has_vnet_hdr = tap_has_vnet_hdr,
358 .has_vnet_hdr_len = tap_has_vnet_hdr_len,
359 .using_vnet_hdr = tap_using_vnet_hdr,
360 .set_offload = tap_set_offload,
361 .set_vnet_hdr_len = tap_set_vnet_hdr_len,
362 .set_vnet_le = tap_set_vnet_le,
363 .set_vnet_be = tap_set_vnet_be,
364 };
365
366 static TAPState *net_tap_fd_init(NetClientState *peer,
367 const char *model,
368 const char *name,
369 int fd,
370 int vnet_hdr)
371 {
372 NetClientState *nc;
373 TAPState *s;
374
375 nc = qemu_new_net_client(&net_tap_info, peer, model, name);
376
377 s = DO_UPCAST(TAPState, nc, nc);
378
379 s->fd = fd;
380 s->host_vnet_hdr_len = vnet_hdr ? sizeof(struct virtio_net_hdr) : 0;
381 s->using_vnet_hdr = false;
382 s->has_ufo = tap_probe_has_ufo(s->fd);
383 s->enabled = true;
384 tap_set_offload(&s->nc, 0, 0, 0, 0, 0);
385 /*
386 * Make sure host header length is set correctly in tap:
387 * it might have been modified by another instance of qemu.
388 */
389 if (tap_probe_vnet_hdr_len(s->fd, s->host_vnet_hdr_len)) {
390 tap_fd_set_vnet_hdr_len(s->fd, s->host_vnet_hdr_len);
391 }
392 tap_read_poll(s, true);
393 s->vhost_net = NULL;
394
395 s->exit.notify = tap_exit_notify;
396 qemu_add_exit_notifier(&s->exit);
397
398 return s;
399 }
400
401 static void launch_script(const char *setup_script, const char *ifname,
402 int fd, Error **errp)
403 {
404 int pid, status;
405 char *args[3];
406 char **parg;
407
408 /* try to launch network script */
409 pid = fork();
410 if (pid < 0) {
411 error_setg_errno(errp, errno, "could not launch network script %s",
412 setup_script);
413 return;
414 }
415 if (pid == 0) {
416 int open_max = sysconf(_SC_OPEN_MAX), i;
417
418 for (i = 3; i < open_max; i++) {
419 if (i != fd) {
420 close(i);
421 }
422 }
423 parg = args;
424 *parg++ = (char *)setup_script;
425 *parg++ = (char *)ifname;
426 *parg = NULL;
427 execv(setup_script, args);
428 _exit(1);
429 } else {
430 while (waitpid(pid, &status, 0) != pid) {
431 /* loop */
432 }
433
434 if (WIFEXITED(status) && WEXITSTATUS(status) == 0) {
435 return;
436 }
437 error_setg(errp, "network script %s failed with status %d",
438 setup_script, status);
439 }
440 }
441
442 static int recv_fd(int c)
443 {
444 int fd;
445 uint8_t msgbuf[CMSG_SPACE(sizeof(fd))];
446 struct msghdr msg = {
447 .msg_control = msgbuf,
448 .msg_controllen = sizeof(msgbuf),
449 };
450 struct cmsghdr *cmsg;
451 struct iovec iov;
452 uint8_t req[1];
453 ssize_t len;
454
455 cmsg = CMSG_FIRSTHDR(&msg);
456 cmsg->cmsg_level = SOL_SOCKET;
457 cmsg->cmsg_type = SCM_RIGHTS;
458 cmsg->cmsg_len = CMSG_LEN(sizeof(fd));
459 msg.msg_controllen = cmsg->cmsg_len;
460
461 iov.iov_base = req;
462 iov.iov_len = sizeof(req);
463
464 msg.msg_iov = &iov;
465 msg.msg_iovlen = 1;
466
467 len = recvmsg(c, &msg, 0);
468 if (len > 0) {
469 memcpy(&fd, CMSG_DATA(cmsg), sizeof(fd));
470 return fd;
471 }
472
473 return len;
474 }
475
476 static int net_bridge_run_helper(const char *helper, const char *bridge,
477 Error **errp)
478 {
479 sigset_t oldmask, mask;
480 int pid, status;
481 char *args[5];
482 char **parg;
483 int sv[2];
484
485 sigemptyset(&mask);
486 sigaddset(&mask, SIGCHLD);
487 sigprocmask(SIG_BLOCK, &mask, &oldmask);
488
489 if (socketpair(PF_UNIX, SOCK_STREAM, 0, sv) == -1) {
490 error_setg_errno(errp, errno, "socketpair() failed");
491 return -1;
492 }
493
494 /* try to launch bridge helper */
495 pid = fork();
496 if (pid < 0) {
497 error_setg_errno(errp, errno, "Can't fork bridge helper");
498 return -1;
499 }
500 if (pid == 0) {
501 int open_max = sysconf(_SC_OPEN_MAX), i;
502 char *fd_buf = NULL;
503 char *br_buf = NULL;
504 char *helper_cmd = NULL;
505
506 for (i = 3; i < open_max; i++) {
507 if (i != sv[1]) {
508 close(i);
509 }
510 }
511
512 fd_buf = g_strdup_printf("%s%d", "--fd=", sv[1]);
513
514 if (strrchr(helper, ' ') || strrchr(helper, '\t')) {
515 /* assume helper is a command */
516
517 if (strstr(helper, "--br=") == NULL) {
518 br_buf = g_strdup_printf("%s%s", "--br=", bridge);
519 }
520
521 helper_cmd = g_strdup_printf("%s %s %s %s", helper,
522 "--use-vnet", fd_buf, br_buf ? br_buf : "");
523
524 parg = args;
525 *parg++ = (char *)"sh";
526 *parg++ = (char *)"-c";
527 *parg++ = helper_cmd;
528 *parg++ = NULL;
529
530 execv("/bin/sh", args);
531 g_free(helper_cmd);
532 } else {
533 /* assume helper is just the executable path name */
534
535 br_buf = g_strdup_printf("%s%s", "--br=", bridge);
536
537 parg = args;
538 *parg++ = (char *)helper;
539 *parg++ = (char *)"--use-vnet";
540 *parg++ = fd_buf;
541 *parg++ = br_buf;
542 *parg++ = NULL;
543
544 execv(helper, args);
545 }
546 g_free(fd_buf);
547 g_free(br_buf);
548 _exit(1);
549
550 } else {
551 int fd;
552 int saved_errno;
553
554 close(sv[1]);
555
556 do {
557 fd = recv_fd(sv[0]);
558 } while (fd == -1 && errno == EINTR);
559 saved_errno = errno;
560
561 close(sv[0]);
562
563 while (waitpid(pid, &status, 0) != pid) {
564 /* loop */
565 }
566 sigprocmask(SIG_SETMASK, &oldmask, NULL);
567 if (fd < 0) {
568 error_setg_errno(errp, saved_errno,
569 "failed to recv file descriptor");
570 return -1;
571 }
572 if (!WIFEXITED(status) || WEXITSTATUS(status) != 0) {
573 error_setg(errp, "bridge helper failed");
574 return -1;
575 }
576 return fd;
577 }
578 }
579
580 int net_init_bridge(const Netdev *netdev, const char *name,
581 NetClientState *peer, Error **errp)
582 {
583 const NetdevBridgeOptions *bridge;
584 const char *helper, *br;
585 TAPState *s;
586 int fd, vnet_hdr;
587
588 assert(netdev->type == NET_CLIENT_DRIVER_BRIDGE);
589 bridge = &netdev->u.bridge;
590
591 helper = bridge->has_helper ? bridge->helper : DEFAULT_BRIDGE_HELPER;
592 br = bridge->has_br ? bridge->br : DEFAULT_BRIDGE_INTERFACE;
593
594 fd = net_bridge_run_helper(helper, br, errp);
595 if (fd == -1) {
596 return -1;
597 }
598
599 qemu_set_nonblock(fd);
600 vnet_hdr = tap_probe_vnet_hdr(fd);
601 s = net_tap_fd_init(peer, "bridge", name, fd, vnet_hdr);
602
603 snprintf(s->nc.info_str, sizeof(s->nc.info_str), "helper=%s,br=%s", helper,
604 br);
605
606 return 0;
607 }
608
609 static int net_tap_init(const NetdevTapOptions *tap, int *vnet_hdr,
610 const char *setup_script, char *ifname,
611 size_t ifname_sz, int mq_required, Error **errp)
612 {
613 Error *err = NULL;
614 int fd, vnet_hdr_required;
615
616 if (tap->has_vnet_hdr) {
617 *vnet_hdr = tap->vnet_hdr;
618 vnet_hdr_required = *vnet_hdr;
619 } else {
620 *vnet_hdr = 1;
621 vnet_hdr_required = 0;
622 }
623
624 TFR(fd = tap_open(ifname, ifname_sz, vnet_hdr, vnet_hdr_required,
625 mq_required, errp));
626 if (fd < 0) {
627 return -1;
628 }
629
630 if (setup_script &&
631 setup_script[0] != '\0' &&
632 strcmp(setup_script, "no") != 0) {
633 launch_script(setup_script, ifname, fd, &err);
634 if (err) {
635 error_propagate(errp, err);
636 close(fd);
637 return -1;
638 }
639 }
640
641 return fd;
642 }
643
644 #define MAX_TAP_QUEUES 1024
645
646 static void net_init_tap_one(const NetdevTapOptions *tap, NetClientState *peer,
647 const char *model, const char *name,
648 const char *ifname, const char *script,
649 const char *downscript, const char *vhostfdname,
650 int vnet_hdr, int fd, Error **errp)
651 {
652 Error *err = NULL;
653 TAPState *s = net_tap_fd_init(peer, model, name, fd, vnet_hdr);
654 int vhostfd;
655
656 tap_set_sndbuf(s->fd, tap, &err);
657 if (err) {
658 error_propagate(errp, err);
659 return;
660 }
661
662 if (tap->has_fd || tap->has_fds) {
663 snprintf(s->nc.info_str, sizeof(s->nc.info_str), "fd=%d", fd);
664 } else if (tap->has_helper) {
665 snprintf(s->nc.info_str, sizeof(s->nc.info_str), "helper=%s",
666 tap->helper);
667 } else {
668 snprintf(s->nc.info_str, sizeof(s->nc.info_str),
669 "ifname=%s,script=%s,downscript=%s", ifname, script,
670 downscript);
671
672 if (strcmp(downscript, "no") != 0) {
673 snprintf(s->down_script, sizeof(s->down_script), "%s", downscript);
674 snprintf(s->down_script_arg, sizeof(s->down_script_arg),
675 "%s", ifname);
676 }
677 }
678
679 if (tap->has_vhost ? tap->vhost :
680 vhostfdname || (tap->has_vhostforce && tap->vhostforce)) {
681 VhostNetOptions options;
682
683 options.backend_type = VHOST_BACKEND_TYPE_KERNEL;
684 options.net_backend = &s->nc;
685 if (tap->has_poll_us) {
686 options.busyloop_timeout = tap->poll_us;
687 } else {
688 options.busyloop_timeout = 0;
689 }
690
691 if (vhostfdname) {
692 vhostfd = monitor_fd_param(cur_mon, vhostfdname, &err);
693 if (vhostfd == -1) {
694 if (tap->has_vhostforce && tap->vhostforce) {
695 error_propagate(errp, err);
696 } else {
697 warn_report_err(err);
698 }
699 return;
700 }
701 qemu_set_nonblock(vhostfd);
702 } else {
703 vhostfd = open("/dev/vhost-net", O_RDWR);
704 if (vhostfd < 0) {
705 if (tap->has_vhostforce && tap->vhostforce) {
706 error_setg_errno(errp, errno,
707 "tap: open vhost char device failed");
708 } else {
709 warn_report("tap: open vhost char device failed: %s",
710 strerror(errno));
711 }
712 return;
713 }
714 qemu_set_nonblock(vhostfd);
715 }
716 options.opaque = (void *)(uintptr_t)vhostfd;
717
718 s->vhost_net = vhost_net_init(&options);
719 if (!s->vhost_net) {
720 if (tap->has_vhostforce && tap->vhostforce) {
721 error_setg(errp, VHOST_NET_INIT_FAILED);
722 } else {
723 warn_report(VHOST_NET_INIT_FAILED);
724 }
725 return;
726 }
727 } else if (vhostfdname) {
728 error_setg(errp, "vhostfd(s)= is not valid without vhost");
729 }
730 }
731
732 static int get_fds(char *str, char *fds[], int max)
733 {
734 char *ptr = str, *this;
735 size_t len = strlen(str);
736 int i = 0;
737
738 while (i < max && ptr < str + len) {
739 this = strchr(ptr, ':');
740
741 if (this == NULL) {
742 fds[i] = g_strdup(ptr);
743 } else {
744 fds[i] = g_strndup(ptr, this - ptr);
745 }
746
747 i++;
748 if (this == NULL) {
749 break;
750 } else {
751 ptr = this + 1;
752 }
753 }
754
755 return i;
756 }
757
758 int net_init_tap(const Netdev *netdev, const char *name,
759 NetClientState *peer, Error **errp)
760 {
761 const NetdevTapOptions *tap;
762 int fd, vnet_hdr = 0, i = 0, queues;
763 /* for the no-fd, no-helper case */
764 const char *script = NULL; /* suppress wrong "uninit'd use" gcc warning */
765 const char *downscript = NULL;
766 Error *err = NULL;
767 const char *vhostfdname;
768 char ifname[128];
769
770 assert(netdev->type == NET_CLIENT_DRIVER_TAP);
771 tap = &netdev->u.tap;
772 queues = tap->has_queues ? tap->queues : 1;
773 vhostfdname = tap->has_vhostfd ? tap->vhostfd : NULL;
774
775 /* QEMU hubs do not support multiqueue tap, in this case peer is set.
776 * For -netdev, peer is always NULL. */
777 if (peer && (tap->has_queues || tap->has_fds || tap->has_vhostfds)) {
778 error_setg(errp, "Multiqueue tap cannot be used with hubs");
779 return -1;
780 }
781
782 if (tap->has_fd) {
783 if (tap->has_ifname || tap->has_script || tap->has_downscript ||
784 tap->has_vnet_hdr || tap->has_helper || tap->has_queues ||
785 tap->has_fds || tap->has_vhostfds) {
786 error_setg(errp, "ifname=, script=, downscript=, vnet_hdr=, "
787 "helper=, queues=, fds=, and vhostfds= "
788 "are invalid with fd=");
789 return -1;
790 }
791
792 fd = monitor_fd_param(cur_mon, tap->fd, &err);
793 if (fd == -1) {
794 error_propagate(errp, err);
795 return -1;
796 }
797
798 qemu_set_nonblock(fd);
799
800 vnet_hdr = tap_probe_vnet_hdr(fd);
801
802 net_init_tap_one(tap, peer, "tap", name, NULL,
803 script, downscript,
804 vhostfdname, vnet_hdr, fd, &err);
805 if (err) {
806 error_propagate(errp, err);
807 return -1;
808 }
809 } else if (tap->has_fds) {
810 char **fds;
811 char **vhost_fds;
812 int nfds = 0, nvhosts = 0;
813 int ret = 0;
814
815 if (tap->has_ifname || tap->has_script || tap->has_downscript ||
816 tap->has_vnet_hdr || tap->has_helper || tap->has_queues ||
817 tap->has_vhostfd) {
818 error_setg(errp, "ifname=, script=, downscript=, vnet_hdr=, "
819 "helper=, queues=, and vhostfd= "
820 "are invalid with fds=");
821 return -1;
822 }
823
824 fds = g_new0(char *, MAX_TAP_QUEUES);
825 vhost_fds = g_new0(char *, MAX_TAP_QUEUES);
826
827 nfds = get_fds(tap->fds, fds, MAX_TAP_QUEUES);
828 if (tap->has_vhostfds) {
829 nvhosts = get_fds(tap->vhostfds, vhost_fds, MAX_TAP_QUEUES);
830 if (nfds != nvhosts) {
831 error_setg(errp, "The number of fds passed does not match "
832 "the number of vhostfds passed");
833 ret = -1;
834 goto free_fail;
835 }
836 }
837
838 for (i = 0; i < nfds; i++) {
839 fd = monitor_fd_param(cur_mon, fds[i], &err);
840 if (fd == -1) {
841 error_propagate(errp, err);
842 ret = -1;
843 goto free_fail;
844 }
845
846 qemu_set_nonblock(fd);
847
848 if (i == 0) {
849 vnet_hdr = tap_probe_vnet_hdr(fd);
850 } else if (vnet_hdr != tap_probe_vnet_hdr(fd)) {
851 error_setg(errp,
852 "vnet_hdr not consistent across given tap fds");
853 ret = -1;
854 goto free_fail;
855 }
856
857 net_init_tap_one(tap, peer, "tap", name, ifname,
858 script, downscript,
859 tap->has_vhostfds ? vhost_fds[i] : NULL,
860 vnet_hdr, fd, &err);
861 if (err) {
862 error_propagate(errp, err);
863 ret = -1;
864 goto free_fail;
865 }
866 }
867
868 free_fail:
869 for (i = 0; i < nvhosts; i++) {
870 g_free(vhost_fds[i]);
871 }
872 for (i = 0; i < nfds; i++) {
873 g_free(fds[i]);
874 }
875 g_free(fds);
876 g_free(vhost_fds);
877 return ret;
878 } else if (tap->has_helper) {
879 if (tap->has_ifname || tap->has_script || tap->has_downscript ||
880 tap->has_vnet_hdr || tap->has_queues || tap->has_vhostfds) {
881 error_setg(errp, "ifname=, script=, downscript=, vnet_hdr=, "
882 "queues=, and vhostfds= are invalid with helper=");
883 return -1;
884 }
885
886 fd = net_bridge_run_helper(tap->helper,
887 tap->has_br ?
888 tap->br : DEFAULT_BRIDGE_INTERFACE,
889 errp);
890 if (fd == -1) {
891 return -1;
892 }
893
894 qemu_set_nonblock(fd);
895 vnet_hdr = tap_probe_vnet_hdr(fd);
896
897 net_init_tap_one(tap, peer, "bridge", name, ifname,
898 script, downscript, vhostfdname,
899 vnet_hdr, fd, &err);
900 if (err) {
901 error_propagate(errp, err);
902 close(fd);
903 return -1;
904 }
905 } else {
906 if (tap->has_vhostfds) {
907 error_setg(errp, "vhostfds= is invalid if fds= wasn't specified");
908 return -1;
909 }
910 script = tap->has_script ? tap->script : DEFAULT_NETWORK_SCRIPT;
911 downscript = tap->has_downscript ? tap->downscript :
912 DEFAULT_NETWORK_DOWN_SCRIPT;
913
914 if (tap->has_ifname) {
915 pstrcpy(ifname, sizeof ifname, tap->ifname);
916 } else {
917 ifname[0] = '\0';
918 }
919
920 for (i = 0; i < queues; i++) {
921 fd = net_tap_init(tap, &vnet_hdr, i >= 1 ? "no" : script,
922 ifname, sizeof ifname, queues > 1, errp);
923 if (fd == -1) {
924 return -1;
925 }
926
927 if (queues > 1 && i == 0 && !tap->has_ifname) {
928 if (tap_fd_get_ifname(fd, ifname)) {
929 error_setg(errp, "Fail to get ifname");
930 close(fd);
931 return -1;
932 }
933 }
934
935 net_init_tap_one(tap, peer, "tap", name, ifname,
936 i >= 1 ? "no" : script,
937 i >= 1 ? "no" : downscript,
938 vhostfdname, vnet_hdr, fd, &err);
939 if (err) {
940 error_propagate(errp, err);
941 close(fd);
942 return -1;
943 }
944 }
945 }
946
947 return 0;
948 }
949
950 VHostNetState *tap_get_vhost_net(NetClientState *nc)
951 {
952 TAPState *s = DO_UPCAST(TAPState, nc, nc);
953 assert(nc->info->type == NET_CLIENT_DRIVER_TAP);
954 return s->vhost_net;
955 }
956
957 int tap_enable(NetClientState *nc)
958 {
959 TAPState *s = DO_UPCAST(TAPState, nc, nc);
960 int ret;
961
962 if (s->enabled) {
963 return 0;
964 } else {
965 ret = tap_fd_enable(s->fd);
966 if (ret == 0) {
967 s->enabled = true;
968 tap_update_fd_handler(s);
969 }
970 return ret;
971 }
972 }
973
974 int tap_disable(NetClientState *nc)
975 {
976 TAPState *s = DO_UPCAST(TAPState, nc, nc);
977 int ret;
978
979 if (s->enabled == 0) {
980 return 0;
981 } else {
982 ret = tap_fd_disable(s->fd);
983 if (ret == 0) {
984 qemu_purge_queued_packets(nc);
985 s->enabled = false;
986 tap_update_fd_handler(s);
987 }
988 return ret;
989 }
990 }