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