Merge remote-tracking branch 'remotes/stefanha/tags/block-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/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
44 #include "net/tap.h"
45
46 #include "net/vhost_net.h"
47
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 Notifier exit;
62 } TAPState;
63
64 static void launch_script(const char *setup_script, const char *ifname,
65 int fd, Error **errp);
66
67 static void tap_send(void *opaque);
68 static void tap_writable(void *opaque);
69
70 static void tap_update_fd_handler(TAPState *s)
71 {
72 qemu_set_fd_handler(s->fd,
73 s->read_poll && s->enabled ? tap_send : NULL,
74 s->write_poll && s->enabled ? tap_writable : NULL,
75 s);
76 }
77
78 static void tap_read_poll(TAPState *s, bool enable)
79 {
80 s->read_poll = enable;
81 tap_update_fd_handler(s);
82 }
83
84 static void tap_write_poll(TAPState *s, bool enable)
85 {
86 s->write_poll = enable;
87 tap_update_fd_handler(s);
88 }
89
90 static void tap_writable(void *opaque)
91 {
92 TAPState *s = opaque;
93
94 tap_write_poll(s, false);
95
96 qemu_flush_queued_packets(&s->nc);
97 }
98
99 static ssize_t tap_write_packet(TAPState *s, const struct iovec *iov, int iovcnt)
100 {
101 ssize_t len;
102
103 do {
104 len = writev(s->fd, iov, iovcnt);
105 } while (len == -1 && errno == EINTR);
106
107 if (len == -1 && errno == EAGAIN) {
108 tap_write_poll(s, true);
109 return 0;
110 }
111
112 return len;
113 }
114
115 static ssize_t tap_receive_iov(NetClientState *nc, const struct iovec *iov,
116 int iovcnt)
117 {
118 TAPState *s = DO_UPCAST(TAPState, nc, nc);
119 const struct iovec *iovp = iov;
120 struct iovec iov_copy[iovcnt + 1];
121 struct virtio_net_hdr_mrg_rxbuf hdr = { };
122
123 if (s->host_vnet_hdr_len && !s->using_vnet_hdr) {
124 iov_copy[0].iov_base = &hdr;
125 iov_copy[0].iov_len = s->host_vnet_hdr_len;
126 memcpy(&iov_copy[1], iov, iovcnt * sizeof(*iov));
127 iovp = iov_copy;
128 iovcnt++;
129 }
130
131 return tap_write_packet(s, iovp, iovcnt);
132 }
133
134 static ssize_t tap_receive_raw(NetClientState *nc, const uint8_t *buf, size_t size)
135 {
136 TAPState *s = DO_UPCAST(TAPState, nc, nc);
137 struct iovec iov[2];
138 int iovcnt = 0;
139 struct virtio_net_hdr_mrg_rxbuf hdr = { };
140
141 if (s->host_vnet_hdr_len) {
142 iov[iovcnt].iov_base = &hdr;
143 iov[iovcnt].iov_len = s->host_vnet_hdr_len;
144 iovcnt++;
145 }
146
147 iov[iovcnt].iov_base = (char *)buf;
148 iov[iovcnt].iov_len = size;
149 iovcnt++;
150
151 return tap_write_packet(s, iov, iovcnt);
152 }
153
154 static ssize_t tap_receive(NetClientState *nc, const uint8_t *buf, size_t size)
155 {
156 TAPState *s = DO_UPCAST(TAPState, nc, nc);
157 struct iovec iov[1];
158
159 if (s->host_vnet_hdr_len && !s->using_vnet_hdr) {
160 return tap_receive_raw(nc, buf, size);
161 }
162
163 iov[0].iov_base = (char *)buf;
164 iov[0].iov_len = size;
165
166 return tap_write_packet(s, iov, 1);
167 }
168
169 #ifndef __sun__
170 ssize_t tap_read_packet(int tapfd, uint8_t *buf, int maxlen)
171 {
172 return read(tapfd, buf, maxlen);
173 }
174 #endif
175
176 static void tap_send_completed(NetClientState *nc, ssize_t len)
177 {
178 TAPState *s = DO_UPCAST(TAPState, nc, nc);
179 tap_read_poll(s, true);
180 }
181
182 static void tap_send(void *opaque)
183 {
184 TAPState *s = opaque;
185 int size;
186 int packets = 0;
187
188 while (true) {
189 uint8_t *buf = s->buf;
190
191 size = tap_read_packet(s->fd, s->buf, sizeof(s->buf));
192 if (size <= 0) {
193 break;
194 }
195
196 if (s->host_vnet_hdr_len && !s->using_vnet_hdr) {
197 buf += s->host_vnet_hdr_len;
198 size -= s->host_vnet_hdr_len;
199 }
200
201 size = qemu_send_packet_async(&s->nc, buf, size, tap_send_completed);
202 if (size == 0) {
203 tap_read_poll(s, false);
204 break;
205 } else if (size < 0) {
206 break;
207 }
208
209 /*
210 * When the host keeps receiving more packets while tap_send() is
211 * running we can hog the QEMU global mutex. Limit the number of
212 * packets that are processed per tap_send() callback to prevent
213 * stalling the guest.
214 */
215 packets++;
216 if (packets >= 50) {
217 break;
218 }
219 }
220 }
221
222 static bool tap_has_ufo(NetClientState *nc)
223 {
224 TAPState *s = DO_UPCAST(TAPState, nc, nc);
225
226 assert(nc->info->type == NET_CLIENT_DRIVER_TAP);
227
228 return s->has_ufo;
229 }
230
231 static bool tap_has_vnet_hdr(NetClientState *nc)
232 {
233 TAPState *s = DO_UPCAST(TAPState, nc, nc);
234
235 assert(nc->info->type == NET_CLIENT_DRIVER_TAP);
236
237 return !!s->host_vnet_hdr_len;
238 }
239
240 static bool tap_has_vnet_hdr_len(NetClientState *nc, int len)
241 {
242 TAPState *s = DO_UPCAST(TAPState, nc, nc);
243
244 assert(nc->info->type == NET_CLIENT_DRIVER_TAP);
245
246 return !!tap_probe_vnet_hdr_len(s->fd, len);
247 }
248
249 static void tap_set_vnet_hdr_len(NetClientState *nc, int len)
250 {
251 TAPState *s = DO_UPCAST(TAPState, nc, nc);
252
253 assert(nc->info->type == NET_CLIENT_DRIVER_TAP);
254 assert(len == sizeof(struct virtio_net_hdr_mrg_rxbuf) ||
255 len == sizeof(struct virtio_net_hdr));
256
257 tap_fd_set_vnet_hdr_len(s->fd, len);
258 s->host_vnet_hdr_len = len;
259 }
260
261 static void tap_using_vnet_hdr(NetClientState *nc, bool using_vnet_hdr)
262 {
263 TAPState *s = DO_UPCAST(TAPState, nc, nc);
264
265 assert(nc->info->type == NET_CLIENT_DRIVER_TAP);
266 assert(!!s->host_vnet_hdr_len == using_vnet_hdr);
267
268 s->using_vnet_hdr = using_vnet_hdr;
269 }
270
271 static int tap_set_vnet_le(NetClientState *nc, bool is_le)
272 {
273 TAPState *s = DO_UPCAST(TAPState, nc, nc);
274
275 return tap_fd_set_vnet_le(s->fd, is_le);
276 }
277
278 static int tap_set_vnet_be(NetClientState *nc, bool is_be)
279 {
280 TAPState *s = DO_UPCAST(TAPState, nc, nc);
281
282 return tap_fd_set_vnet_be(s->fd, is_be);
283 }
284
285 static void tap_set_offload(NetClientState *nc, int csum, int tso4,
286 int tso6, int ecn, int ufo)
287 {
288 TAPState *s = DO_UPCAST(TAPState, nc, nc);
289 if (s->fd < 0) {
290 return;
291 }
292
293 tap_fd_set_offload(s->fd, csum, tso4, tso6, ecn, ufo);
294 }
295
296 static void tap_exit_notify(Notifier *notifier, void *data)
297 {
298 TAPState *s = container_of(notifier, TAPState, exit);
299 Error *err = NULL;
300
301 if (s->down_script[0]) {
302 launch_script(s->down_script, s->down_script_arg, s->fd, &err);
303 if (err) {
304 error_report_err(err);
305 }
306 }
307 }
308
309 static void tap_cleanup(NetClientState *nc)
310 {
311 TAPState *s = DO_UPCAST(TAPState, nc, nc);
312
313 if (s->vhost_net) {
314 vhost_net_cleanup(s->vhost_net);
315 g_free(s->vhost_net);
316 s->vhost_net = NULL;
317 }
318
319 qemu_purge_queued_packets(nc);
320
321 tap_exit_notify(&s->exit, NULL);
322 qemu_remove_exit_notifier(&s->exit);
323
324 tap_read_poll(s, false);
325 tap_write_poll(s, false);
326 close(s->fd);
327 s->fd = -1;
328 }
329
330 static void tap_poll(NetClientState *nc, bool enable)
331 {
332 TAPState *s = DO_UPCAST(TAPState, nc, nc);
333 tap_read_poll(s, enable);
334 tap_write_poll(s, enable);
335 }
336
337 int tap_get_fd(NetClientState *nc)
338 {
339 TAPState *s = DO_UPCAST(TAPState, nc, nc);
340 assert(nc->info->type == NET_CLIENT_DRIVER_TAP);
341 return s->fd;
342 }
343
344 /* fd support */
345
346 static NetClientInfo net_tap_info = {
347 .type = NET_CLIENT_DRIVER_TAP,
348 .size = sizeof(TAPState),
349 .receive = tap_receive,
350 .receive_raw = tap_receive_raw,
351 .receive_iov = tap_receive_iov,
352 .poll = tap_poll,
353 .cleanup = tap_cleanup,
354 .has_ufo = tap_has_ufo,
355 .has_vnet_hdr = tap_has_vnet_hdr,
356 .has_vnet_hdr_len = tap_has_vnet_hdr_len,
357 .using_vnet_hdr = tap_using_vnet_hdr,
358 .set_offload = tap_set_offload,
359 .set_vnet_hdr_len = tap_set_vnet_hdr_len,
360 .set_vnet_le = tap_set_vnet_le,
361 .set_vnet_be = tap_set_vnet_be,
362 };
363
364 static TAPState *net_tap_fd_init(NetClientState *peer,
365 const char *model,
366 const char *name,
367 int fd,
368 int vnet_hdr)
369 {
370 NetClientState *nc;
371 TAPState *s;
372
373 nc = qemu_new_net_client(&net_tap_info, peer, model, name);
374
375 s = DO_UPCAST(TAPState, nc, nc);
376
377 s->fd = fd;
378 s->host_vnet_hdr_len = vnet_hdr ? sizeof(struct virtio_net_hdr) : 0;
379 s->using_vnet_hdr = false;
380 s->has_ufo = tap_probe_has_ufo(s->fd);
381 s->enabled = true;
382 tap_set_offload(&s->nc, 0, 0, 0, 0, 0);
383 /*
384 * Make sure host header length is set correctly in tap:
385 * it might have been modified by another instance of qemu.
386 */
387 if (tap_probe_vnet_hdr_len(s->fd, s->host_vnet_hdr_len)) {
388 tap_fd_set_vnet_hdr_len(s->fd, s->host_vnet_hdr_len);
389 }
390 tap_read_poll(s, true);
391 s->vhost_net = NULL;
392
393 s->exit.notify = tap_exit_notify;
394 qemu_add_exit_notifier(&s->exit);
395
396 return s;
397 }
398
399 static void launch_script(const char *setup_script, const char *ifname,
400 int fd, Error **errp)
401 {
402 int pid, status;
403 char *args[3];
404 char **parg;
405
406 /* try to launch network script */
407 pid = fork();
408 if (pid < 0) {
409 error_setg_errno(errp, errno, "could not launch network script %s",
410 setup_script);
411 return;
412 }
413 if (pid == 0) {
414 int open_max = sysconf(_SC_OPEN_MAX), i;
415
416 for (i = 3; i < open_max; i++) {
417 if (i != fd) {
418 close(i);
419 }
420 }
421 parg = args;
422 *parg++ = (char *)setup_script;
423 *parg++ = (char *)ifname;
424 *parg = NULL;
425 execv(setup_script, args);
426 _exit(1);
427 } else {
428 while (waitpid(pid, &status, 0) != pid) {
429 /* loop */
430 }
431
432 if (WIFEXITED(status) && WEXITSTATUS(status) == 0) {
433 return;
434 }
435 error_setg(errp, "network script %s failed with status %d",
436 setup_script, status);
437 }
438 }
439
440 static int recv_fd(int c)
441 {
442 int fd;
443 uint8_t msgbuf[CMSG_SPACE(sizeof(fd))];
444 struct msghdr msg = {
445 .msg_control = msgbuf,
446 .msg_controllen = sizeof(msgbuf),
447 };
448 struct cmsghdr *cmsg;
449 struct iovec iov;
450 uint8_t req[1];
451 ssize_t len;
452
453 cmsg = CMSG_FIRSTHDR(&msg);
454 cmsg->cmsg_level = SOL_SOCKET;
455 cmsg->cmsg_type = SCM_RIGHTS;
456 cmsg->cmsg_len = CMSG_LEN(sizeof(fd));
457 msg.msg_controllen = cmsg->cmsg_len;
458
459 iov.iov_base = req;
460 iov.iov_len = sizeof(req);
461
462 msg.msg_iov = &iov;
463 msg.msg_iovlen = 1;
464
465 len = recvmsg(c, &msg, 0);
466 if (len > 0) {
467 memcpy(&fd, CMSG_DATA(cmsg), sizeof(fd));
468 return fd;
469 }
470
471 return len;
472 }
473
474 static int net_bridge_run_helper(const char *helper, const char *bridge,
475 Error **errp)
476 {
477 sigset_t oldmask, mask;
478 int pid, status;
479 char *args[5];
480 char **parg;
481 int sv[2];
482
483 sigemptyset(&mask);
484 sigaddset(&mask, SIGCHLD);
485 sigprocmask(SIG_BLOCK, &mask, &oldmask);
486
487 if (socketpair(PF_UNIX, SOCK_STREAM, 0, sv) == -1) {
488 error_setg_errno(errp, errno, "socketpair() failed");
489 return -1;
490 }
491
492 /* try to launch bridge helper */
493 pid = fork();
494 if (pid < 0) {
495 error_setg_errno(errp, errno, "Can't fork bridge helper");
496 return -1;
497 }
498 if (pid == 0) {
499 int open_max = sysconf(_SC_OPEN_MAX), i;
500 char fd_buf[6+10];
501 char br_buf[6+IFNAMSIZ] = {0};
502 char helper_cmd[PATH_MAX + sizeof(fd_buf) + sizeof(br_buf) + 15];
503
504 for (i = 3; i < open_max; i++) {
505 if (i != sv[1]) {
506 close(i);
507 }
508 }
509
510 snprintf(fd_buf, sizeof(fd_buf), "%s%d", "--fd=", sv[1]);
511
512 if (strrchr(helper, ' ') || strrchr(helper, '\t')) {
513 /* assume helper is a command */
514
515 if (strstr(helper, "--br=") == NULL) {
516 snprintf(br_buf, sizeof(br_buf), "%s%s", "--br=", bridge);
517 }
518
519 snprintf(helper_cmd, sizeof(helper_cmd), "%s %s %s %s",
520 helper, "--use-vnet", fd_buf, br_buf);
521
522 parg = args;
523 *parg++ = (char *)"sh";
524 *parg++ = (char *)"-c";
525 *parg++ = helper_cmd;
526 *parg++ = NULL;
527
528 execv("/bin/sh", args);
529 } else {
530 /* assume helper is just the executable path name */
531
532 snprintf(br_buf, sizeof(br_buf), "%s%s", "--br=", bridge);
533
534 parg = args;
535 *parg++ = (char *)helper;
536 *parg++ = (char *)"--use-vnet";
537 *parg++ = fd_buf;
538 *parg++ = br_buf;
539 *parg++ = NULL;
540
541 execv(helper, args);
542 }
543 _exit(1);
544
545 } else {
546 int fd;
547 int saved_errno;
548
549 close(sv[1]);
550
551 do {
552 fd = recv_fd(sv[0]);
553 } while (fd == -1 && errno == EINTR);
554 saved_errno = errno;
555
556 close(sv[0]);
557
558 while (waitpid(pid, &status, 0) != pid) {
559 /* loop */
560 }
561 sigprocmask(SIG_SETMASK, &oldmask, NULL);
562 if (fd < 0) {
563 error_setg_errno(errp, saved_errno,
564 "failed to recv file descriptor");
565 return -1;
566 }
567 if (!WIFEXITED(status) || WEXITSTATUS(status) != 0) {
568 error_setg(errp, "bridge helper failed");
569 return -1;
570 }
571 return fd;
572 }
573 }
574
575 int net_init_bridge(const Netdev *netdev, const char *name,
576 NetClientState *peer, Error **errp)
577 {
578 const NetdevBridgeOptions *bridge;
579 const char *helper, *br;
580 TAPState *s;
581 int fd, vnet_hdr;
582
583 assert(netdev->type == NET_CLIENT_DRIVER_BRIDGE);
584 bridge = &netdev->u.bridge;
585
586 helper = bridge->has_helper ? bridge->helper : DEFAULT_BRIDGE_HELPER;
587 br = bridge->has_br ? bridge->br : DEFAULT_BRIDGE_INTERFACE;
588
589 fd = net_bridge_run_helper(helper, br, errp);
590 if (fd == -1) {
591 return -1;
592 }
593
594 fcntl(fd, F_SETFL, O_NONBLOCK);
595 vnet_hdr = tap_probe_vnet_hdr(fd);
596 s = net_tap_fd_init(peer, "bridge", name, fd, vnet_hdr);
597
598 snprintf(s->nc.info_str, sizeof(s->nc.info_str), "helper=%s,br=%s", helper,
599 br);
600
601 return 0;
602 }
603
604 static int net_tap_init(const NetdevTapOptions *tap, int *vnet_hdr,
605 const char *setup_script, char *ifname,
606 size_t ifname_sz, int mq_required, Error **errp)
607 {
608 Error *err = NULL;
609 int fd, vnet_hdr_required;
610
611 if (tap->has_vnet_hdr) {
612 *vnet_hdr = tap->vnet_hdr;
613 vnet_hdr_required = *vnet_hdr;
614 } else {
615 *vnet_hdr = 1;
616 vnet_hdr_required = 0;
617 }
618
619 TFR(fd = tap_open(ifname, ifname_sz, vnet_hdr, vnet_hdr_required,
620 mq_required, errp));
621 if (fd < 0) {
622 return -1;
623 }
624
625 if (setup_script &&
626 setup_script[0] != '\0' &&
627 strcmp(setup_script, "no") != 0) {
628 launch_script(setup_script, ifname, fd, &err);
629 if (err) {
630 error_propagate(errp, err);
631 close(fd);
632 return -1;
633 }
634 }
635
636 return fd;
637 }
638
639 #define MAX_TAP_QUEUES 1024
640
641 static void net_init_tap_one(const NetdevTapOptions *tap, NetClientState *peer,
642 const char *model, const char *name,
643 const char *ifname, const char *script,
644 const char *downscript, const char *vhostfdname,
645 int vnet_hdr, int fd, Error **errp)
646 {
647 Error *err = NULL;
648 TAPState *s = net_tap_fd_init(peer, model, name, fd, vnet_hdr);
649 int vhostfd;
650
651 tap_set_sndbuf(s->fd, tap, &err);
652 if (err) {
653 error_propagate(errp, err);
654 return;
655 }
656
657 if (tap->has_fd || tap->has_fds) {
658 snprintf(s->nc.info_str, sizeof(s->nc.info_str), "fd=%d", fd);
659 } else if (tap->has_helper) {
660 snprintf(s->nc.info_str, sizeof(s->nc.info_str), "helper=%s",
661 tap->helper);
662 } else {
663 snprintf(s->nc.info_str, sizeof(s->nc.info_str),
664 "ifname=%s,script=%s,downscript=%s", ifname, script,
665 downscript);
666
667 if (strcmp(downscript, "no") != 0) {
668 snprintf(s->down_script, sizeof(s->down_script), "%s", downscript);
669 snprintf(s->down_script_arg, sizeof(s->down_script_arg),
670 "%s", ifname);
671 }
672 }
673
674 if (tap->has_vhost ? tap->vhost :
675 vhostfdname || (tap->has_vhostforce && tap->vhostforce)) {
676 VhostNetOptions options;
677
678 options.backend_type = VHOST_BACKEND_TYPE_KERNEL;
679 options.net_backend = &s->nc;
680 if (tap->has_poll_us) {
681 options.busyloop_timeout = tap->poll_us;
682 } else {
683 options.busyloop_timeout = 0;
684 }
685
686 if (vhostfdname) {
687 vhostfd = monitor_fd_param(cur_mon, vhostfdname, &err);
688 if (vhostfd == -1) {
689 error_propagate(errp, err);
690 return;
691 }
692 } else {
693 vhostfd = open("/dev/vhost-net", O_RDWR);
694 if (vhostfd < 0) {
695 error_setg_errno(errp, errno,
696 "tap: open vhost char device failed");
697 return;
698 }
699 }
700 options.opaque = (void *)(uintptr_t)vhostfd;
701
702 s->vhost_net = vhost_net_init(&options);
703 if (!s->vhost_net) {
704 error_setg(errp,
705 "vhost-net requested but could not be initialized");
706 return;
707 }
708 } else if (vhostfdname) {
709 error_setg(errp, "vhostfd(s)= is not valid without vhost");
710 }
711 }
712
713 static int get_fds(char *str, char *fds[], int max)
714 {
715 char *ptr = str, *this;
716 size_t len = strlen(str);
717 int i = 0;
718
719 while (i < max && ptr < str + len) {
720 this = strchr(ptr, ':');
721
722 if (this == NULL) {
723 fds[i] = g_strdup(ptr);
724 } else {
725 fds[i] = g_strndup(ptr, this - ptr);
726 }
727
728 i++;
729 if (this == NULL) {
730 break;
731 } else {
732 ptr = this + 1;
733 }
734 }
735
736 return i;
737 }
738
739 int net_init_tap(const Netdev *netdev, const char *name,
740 NetClientState *peer, Error **errp)
741 {
742 const NetdevTapOptions *tap;
743 int fd, vnet_hdr = 0, i = 0, queues;
744 /* for the no-fd, no-helper case */
745 const char *script = NULL; /* suppress wrong "uninit'd use" gcc warning */
746 const char *downscript = NULL;
747 Error *err = NULL;
748 const char *vhostfdname;
749 char ifname[128];
750
751 assert(netdev->type == NET_CLIENT_DRIVER_TAP);
752 tap = &netdev->u.tap;
753 queues = tap->has_queues ? tap->queues : 1;
754 vhostfdname = tap->has_vhostfd ? tap->vhostfd : NULL;
755
756 /* QEMU vlans does not support multiqueue tap, in this case peer is set.
757 * For -netdev, peer is always NULL. */
758 if (peer && (tap->has_queues || tap->has_fds || tap->has_vhostfds)) {
759 error_setg(errp, "Multiqueue tap cannot be used with QEMU vlans");
760 return -1;
761 }
762
763 if (tap->has_fd) {
764 if (tap->has_ifname || tap->has_script || tap->has_downscript ||
765 tap->has_vnet_hdr || tap->has_helper || tap->has_queues ||
766 tap->has_fds || tap->has_vhostfds) {
767 error_setg(errp, "ifname=, script=, downscript=, vnet_hdr=, "
768 "helper=, queues=, fds=, and vhostfds= "
769 "are invalid with fd=");
770 return -1;
771 }
772
773 fd = monitor_fd_param(cur_mon, tap->fd, &err);
774 if (fd == -1) {
775 error_propagate(errp, err);
776 return -1;
777 }
778
779 fcntl(fd, F_SETFL, O_NONBLOCK);
780
781 vnet_hdr = tap_probe_vnet_hdr(fd);
782
783 net_init_tap_one(tap, peer, "tap", name, NULL,
784 script, downscript,
785 vhostfdname, vnet_hdr, fd, &err);
786 if (err) {
787 error_propagate(errp, err);
788 return -1;
789 }
790 } else if (tap->has_fds) {
791 char **fds = g_new0(char *, MAX_TAP_QUEUES);
792 char **vhost_fds = g_new0(char *, MAX_TAP_QUEUES);
793 int nfds, nvhosts;
794
795 if (tap->has_ifname || tap->has_script || tap->has_downscript ||
796 tap->has_vnet_hdr || tap->has_helper || tap->has_queues ||
797 tap->has_vhostfd) {
798 error_setg(errp, "ifname=, script=, downscript=, vnet_hdr=, "
799 "helper=, queues=, and vhostfd= "
800 "are invalid with fds=");
801 return -1;
802 }
803
804 nfds = get_fds(tap->fds, fds, MAX_TAP_QUEUES);
805 if (tap->has_vhostfds) {
806 nvhosts = get_fds(tap->vhostfds, vhost_fds, MAX_TAP_QUEUES);
807 if (nfds != nvhosts) {
808 error_setg(errp, "The number of fds passed does not match "
809 "the number of vhostfds passed");
810 goto free_fail;
811 }
812 }
813
814 for (i = 0; i < nfds; i++) {
815 fd = monitor_fd_param(cur_mon, fds[i], &err);
816 if (fd == -1) {
817 error_propagate(errp, err);
818 goto free_fail;
819 }
820
821 fcntl(fd, F_SETFL, O_NONBLOCK);
822
823 if (i == 0) {
824 vnet_hdr = tap_probe_vnet_hdr(fd);
825 } else if (vnet_hdr != tap_probe_vnet_hdr(fd)) {
826 error_setg(errp,
827 "vnet_hdr not consistent across given tap fds");
828 goto free_fail;
829 }
830
831 net_init_tap_one(tap, peer, "tap", name, ifname,
832 script, downscript,
833 tap->has_vhostfds ? vhost_fds[i] : NULL,
834 vnet_hdr, fd, &err);
835 if (err) {
836 error_propagate(errp, err);
837 goto free_fail;
838 }
839 }
840 g_free(fds);
841 g_free(vhost_fds);
842 return 0;
843
844 free_fail:
845 for (i = 0; i < nfds; i++) {
846 g_free(fds[i]);
847 g_free(vhost_fds[i]);
848 }
849 g_free(fds);
850 g_free(vhost_fds);
851 return -1;
852 } else if (tap->has_helper) {
853 if (tap->has_ifname || tap->has_script || tap->has_downscript ||
854 tap->has_vnet_hdr || tap->has_queues || tap->has_vhostfds) {
855 error_setg(errp, "ifname=, script=, downscript=, vnet_hdr=, "
856 "queues=, and vhostfds= are invalid with helper=");
857 return -1;
858 }
859
860 fd = net_bridge_run_helper(tap->helper,
861 tap->has_br ?
862 tap->br : DEFAULT_BRIDGE_INTERFACE,
863 errp);
864 if (fd == -1) {
865 return -1;
866 }
867
868 fcntl(fd, F_SETFL, O_NONBLOCK);
869 vnet_hdr = tap_probe_vnet_hdr(fd);
870
871 net_init_tap_one(tap, peer, "bridge", name, ifname,
872 script, downscript, vhostfdname,
873 vnet_hdr, fd, &err);
874 if (err) {
875 error_propagate(errp, err);
876 close(fd);
877 return -1;
878 }
879 } else {
880 if (tap->has_vhostfds) {
881 error_setg(errp, "vhostfds= is invalid if fds= wasn't specified");
882 return -1;
883 }
884 script = tap->has_script ? tap->script : DEFAULT_NETWORK_SCRIPT;
885 downscript = tap->has_downscript ? tap->downscript :
886 DEFAULT_NETWORK_DOWN_SCRIPT;
887
888 if (tap->has_ifname) {
889 pstrcpy(ifname, sizeof ifname, tap->ifname);
890 } else {
891 ifname[0] = '\0';
892 }
893
894 for (i = 0; i < queues; i++) {
895 fd = net_tap_init(tap, &vnet_hdr, i >= 1 ? "no" : script,
896 ifname, sizeof ifname, queues > 1, errp);
897 if (fd == -1) {
898 return -1;
899 }
900
901 if (queues > 1 && i == 0 && !tap->has_ifname) {
902 if (tap_fd_get_ifname(fd, ifname)) {
903 error_setg(errp, "Fail to get ifname");
904 close(fd);
905 return -1;
906 }
907 }
908
909 net_init_tap_one(tap, peer, "tap", name, ifname,
910 i >= 1 ? "no" : script,
911 i >= 1 ? "no" : downscript,
912 vhostfdname, vnet_hdr, fd, &err);
913 if (err) {
914 error_propagate(errp, err);
915 close(fd);
916 return -1;
917 }
918 }
919 }
920
921 return 0;
922 }
923
924 VHostNetState *tap_get_vhost_net(NetClientState *nc)
925 {
926 TAPState *s = DO_UPCAST(TAPState, nc, nc);
927 assert(nc->info->type == NET_CLIENT_DRIVER_TAP);
928 return s->vhost_net;
929 }
930
931 int tap_enable(NetClientState *nc)
932 {
933 TAPState *s = DO_UPCAST(TAPState, nc, nc);
934 int ret;
935
936 if (s->enabled) {
937 return 0;
938 } else {
939 ret = tap_fd_enable(s->fd);
940 if (ret == 0) {
941 s->enabled = true;
942 tap_update_fd_handler(s);
943 }
944 return ret;
945 }
946 }
947
948 int tap_disable(NetClientState *nc)
949 {
950 TAPState *s = DO_UPCAST(TAPState, nc, nc);
951 int ret;
952
953 if (s->enabled == 0) {
954 return 0;
955 } else {
956 ret = tap_fd_disable(s->fd);
957 if (ret == 0) {
958 qemu_purge_queued_packets(nc);
959 s->enabled = false;
960 tap_update_fd_handler(s);
961 }
962 return ret;
963 }
964 }