1 /*
2 * QEMU System Emulator
3 *
4 * Copyright (c) 2003-2008 Fabrice Bellard
5 * Copyright (c) 2009 Red Hat, Inc.
6 *
7 * Permission is hereby granted, free of charge, to any person obtaining a copy
8 * of this software and associated documentation files (the "Software"), to deal
9 * in the Software without restriction, including without limitation the rights
10 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
11 * copies of the Software, and to permit persons to whom the Software is
12 * furnished to do so, subject to the following conditions:
13 *
14 * The above copyright notice and this permission notice shall be included in
15 * all copies or substantial portions of the Software.
16 *
17 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
18 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
19 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
20 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
21 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
22 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
23 * THE SOFTWARE.
24 */
25
26 #include "qemu/osdep.h"
27 #include "tap_int.h"
28
29
30 #include <sys/ioctl.h>
31 #include <sys/wait.h>
32 #include <sys/socket.h>
33 #include <net/if.h>
34
35 #include "net/eth.h"
36 #include "net/net.h"
37 #include "clients.h"
38 #include "monitor/monitor.h"
39 #include "sysemu/sysemu.h"
40 #include "qapi/error.h"
41 #include "qemu/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 has_uso;
61 bool enabled;
62 VHostNetState *vhost_net;
63 unsigned host_vnet_hdr_len;
64 Notifier exit;
65 } TAPState;
66
67 static void launch_script(const char *setup_script, const char *ifname,
68 int fd, Error **errp);
69
70 static void tap_send(void *opaque);
71 static void tap_writable(void *opaque);
72
tap_update_fd_handler(TAPState * s)73 static void tap_update_fd_handler(TAPState *s)
74 {
75 qemu_set_fd_handler(s->fd,
76 s->read_poll && s->enabled ? tap_send : NULL,
77 s->write_poll && s->enabled ? tap_writable : NULL,
78 s);
79 }
80
tap_read_poll(TAPState * s,bool enable)81 static void tap_read_poll(TAPState *s, bool enable)
82 {
83 s->read_poll = enable;
84 tap_update_fd_handler(s);
85 }
86
tap_write_poll(TAPState * s,bool enable)87 static void tap_write_poll(TAPState *s, bool enable)
88 {
89 s->write_poll = enable;
90 tap_update_fd_handler(s);
91 }
92
tap_writable(void * opaque)93 static void tap_writable(void *opaque)
94 {
95 TAPState *s = opaque;
96
97 tap_write_poll(s, false);
98
99 qemu_flush_queued_packets(&s->nc);
100 }
101
tap_write_packet(TAPState * s,const struct iovec * iov,int iovcnt)102 static ssize_t tap_write_packet(TAPState *s, const struct iovec *iov, int iovcnt)
103 {
104 ssize_t len;
105
106 len = RETRY_ON_EINTR(writev(s->fd, iov, iovcnt));
107
108 if (len == -1 && errno == EAGAIN) {
109 tap_write_poll(s, true);
110 return 0;
111 }
112
113 return len;
114 }
115
tap_receive_iov(NetClientState * nc,const struct iovec * iov,int iovcnt)116 static ssize_t tap_receive_iov(NetClientState *nc, const struct iovec *iov,
117 int iovcnt)
118 {
119 TAPState *s = DO_UPCAST(TAPState, nc, nc);
120 const struct iovec *iovp = iov;
121 g_autofree struct iovec *iov_copy = NULL;
122 struct virtio_net_hdr hdr = { };
123
124 if (s->host_vnet_hdr_len && !s->using_vnet_hdr) {
125 iov_copy = g_new(struct iovec, iovcnt + 1);
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
tap_receive(NetClientState * nc,const uint8_t * buf,size_t size)136 static ssize_t tap_receive(NetClientState *nc, const uint8_t *buf, size_t size)
137 {
138 struct iovec iov = {
139 .iov_base = (void *)buf,
140 .iov_len = size
141 };
142
143 return tap_receive_iov(nc, &iov, 1);
144 }
145
146 #ifndef __sun__
tap_read_packet(int tapfd,uint8_t * buf,int maxlen)147 ssize_t tap_read_packet(int tapfd, uint8_t *buf, int maxlen)
148 {
149 return read(tapfd, buf, maxlen);
150 }
151 #endif
152
tap_send_completed(NetClientState * nc,ssize_t len)153 static void tap_send_completed(NetClientState *nc, ssize_t len)
154 {
155 TAPState *s = DO_UPCAST(TAPState, nc, nc);
156 tap_read_poll(s, true);
157 }
158
tap_send(void * opaque)159 static void tap_send(void *opaque)
160 {
161 TAPState *s = opaque;
162 int size;
163 int packets = 0;
164
165 while (true) {
166 uint8_t *buf = s->buf;
167 uint8_t min_pkt[ETH_ZLEN];
168 size_t min_pktsz = sizeof(min_pkt);
169
170 size = tap_read_packet(s->fd, s->buf, sizeof(s->buf));
171 if (size <= 0) {
172 break;
173 }
174
175 if (s->host_vnet_hdr_len && !s->using_vnet_hdr) {
176 buf += s->host_vnet_hdr_len;
177 size -= s->host_vnet_hdr_len;
178 }
179
180 if (net_peer_needs_padding(&s->nc)) {
181 if (eth_pad_short_frame(min_pkt, &min_pktsz, buf, size)) {
182 buf = min_pkt;
183 size = min_pktsz;
184 }
185 }
186
187 size = qemu_send_packet_async(&s->nc, buf, size, tap_send_completed);
188 if (size == 0) {
189 tap_read_poll(s, false);
190 break;
191 } else if (size < 0) {
192 break;
193 }
194
195 /*
196 * When the host keeps receiving more packets while tap_send() is
197 * running we can hog the BQL. Limit the number of
198 * packets that are processed per tap_send() callback to prevent
199 * stalling the guest.
200 */
201 packets++;
202 if (packets >= 50) {
203 break;
204 }
205 }
206 }
207
tap_has_ufo(NetClientState * nc)208 static bool tap_has_ufo(NetClientState *nc)
209 {
210 TAPState *s = DO_UPCAST(TAPState, nc, nc);
211
212 assert(nc->info->type == NET_CLIENT_DRIVER_TAP);
213
214 return s->has_ufo;
215 }
216
tap_has_uso(NetClientState * nc)217 static bool tap_has_uso(NetClientState *nc)
218 {
219 TAPState *s = DO_UPCAST(TAPState, nc, nc);
220
221 assert(nc->info->type == NET_CLIENT_DRIVER_TAP);
222
223 return s->has_uso;
224 }
225
tap_has_vnet_hdr(NetClientState * nc)226 static bool tap_has_vnet_hdr(NetClientState *nc)
227 {
228 TAPState *s = DO_UPCAST(TAPState, nc, nc);
229
230 assert(nc->info->type == NET_CLIENT_DRIVER_TAP);
231
232 return !!s->host_vnet_hdr_len;
233 }
234
tap_has_vnet_hdr_len(NetClientState * nc,int len)235 static bool tap_has_vnet_hdr_len(NetClientState *nc, int len)
236 {
237 return tap_has_vnet_hdr(nc);
238 }
239
tap_set_vnet_hdr_len(NetClientState * nc,int len)240 static void tap_set_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 tap_fd_set_vnet_hdr_len(s->fd, len);
247 s->host_vnet_hdr_len = len;
248 s->using_vnet_hdr = true;
249 }
250
tap_set_vnet_le(NetClientState * nc,bool is_le)251 static int tap_set_vnet_le(NetClientState *nc, bool is_le)
252 {
253 TAPState *s = DO_UPCAST(TAPState, nc, nc);
254
255 return tap_fd_set_vnet_le(s->fd, is_le);
256 }
257
tap_set_vnet_be(NetClientState * nc,bool is_be)258 static int tap_set_vnet_be(NetClientState *nc, bool is_be)
259 {
260 TAPState *s = DO_UPCAST(TAPState, nc, nc);
261
262 return tap_fd_set_vnet_be(s->fd, is_be);
263 }
264
tap_set_offload(NetClientState * nc,int csum,int tso4,int tso6,int ecn,int ufo,int uso4,int uso6)265 static void tap_set_offload(NetClientState *nc, int csum, int tso4,
266 int tso6, int ecn, int ufo, int uso4, int uso6)
267 {
268 TAPState *s = DO_UPCAST(TAPState, nc, nc);
269 if (s->fd < 0) {
270 return;
271 }
272
273 tap_fd_set_offload(s->fd, csum, tso4, tso6, ecn, ufo, uso4, uso6);
274 }
275
tap_exit_notify(Notifier * notifier,void * data)276 static void tap_exit_notify(Notifier *notifier, void *data)
277 {
278 TAPState *s = container_of(notifier, TAPState, exit);
279 Error *err = NULL;
280
281 if (s->down_script[0]) {
282 launch_script(s->down_script, s->down_script_arg, s->fd, &err);
283 if (err) {
284 error_report_err(err);
285 }
286 }
287 }
288
tap_cleanup(NetClientState * nc)289 static void tap_cleanup(NetClientState *nc)
290 {
291 TAPState *s = DO_UPCAST(TAPState, nc, nc);
292
293 if (s->vhost_net) {
294 vhost_net_cleanup(s->vhost_net);
295 g_free(s->vhost_net);
296 s->vhost_net = NULL;
297 }
298
299 qemu_purge_queued_packets(nc);
300
301 tap_exit_notify(&s->exit, NULL);
302 qemu_remove_exit_notifier(&s->exit);
303
304 tap_read_poll(s, false);
305 tap_write_poll(s, false);
306 close(s->fd);
307 s->fd = -1;
308 }
309
tap_poll(NetClientState * nc,bool enable)310 static void tap_poll(NetClientState *nc, bool enable)
311 {
312 TAPState *s = DO_UPCAST(TAPState, nc, nc);
313 tap_read_poll(s, enable);
314 tap_write_poll(s, enable);
315 }
316
tap_set_steering_ebpf(NetClientState * nc,int prog_fd)317 static bool tap_set_steering_ebpf(NetClientState *nc, int prog_fd)
318 {
319 TAPState *s = DO_UPCAST(TAPState, nc, nc);
320 assert(nc->info->type == NET_CLIENT_DRIVER_TAP);
321
322 return tap_fd_set_steering_ebpf(s->fd, prog_fd) == 0;
323 }
324
tap_get_fd(NetClientState * nc)325 int tap_get_fd(NetClientState *nc)
326 {
327 TAPState *s = DO_UPCAST(TAPState, nc, nc);
328 assert(nc->info->type == NET_CLIENT_DRIVER_TAP);
329 return s->fd;
330 }
331
332 /* fd support */
333
334 static NetClientInfo net_tap_info = {
335 .type = NET_CLIENT_DRIVER_TAP,
336 .size = sizeof(TAPState),
337 .receive = tap_receive,
338 .receive_iov = tap_receive_iov,
339 .poll = tap_poll,
340 .cleanup = tap_cleanup,
341 .has_ufo = tap_has_ufo,
342 .has_uso = tap_has_uso,
343 .has_vnet_hdr = tap_has_vnet_hdr,
344 .has_vnet_hdr_len = tap_has_vnet_hdr_len,
345 .set_offload = tap_set_offload,
346 .set_vnet_hdr_len = tap_set_vnet_hdr_len,
347 .set_vnet_le = tap_set_vnet_le,
348 .set_vnet_be = tap_set_vnet_be,
349 .set_steering_ebpf = tap_set_steering_ebpf,
350 };
351
net_tap_fd_init(NetClientState * peer,const char * model,const char * name,int fd,int vnet_hdr)352 static TAPState *net_tap_fd_init(NetClientState *peer,
353 const char *model,
354 const char *name,
355 int fd,
356 int vnet_hdr)
357 {
358 NetClientState *nc;
359 TAPState *s;
360
361 nc = qemu_new_net_client(&net_tap_info, peer, model, name);
362
363 s = DO_UPCAST(TAPState, nc, nc);
364
365 s->fd = fd;
366 s->host_vnet_hdr_len = vnet_hdr ? sizeof(struct virtio_net_hdr) : 0;
367 s->using_vnet_hdr = false;
368 s->has_ufo = tap_probe_has_ufo(s->fd);
369 s->has_uso = tap_probe_has_uso(s->fd);
370 s->enabled = true;
371 tap_set_offload(&s->nc, 0, 0, 0, 0, 0, 0, 0);
372 /*
373 * Make sure host header length is set correctly in tap:
374 * it might have been modified by another instance of qemu.
375 */
376 if (vnet_hdr) {
377 tap_fd_set_vnet_hdr_len(s->fd, s->host_vnet_hdr_len);
378 }
379 tap_read_poll(s, true);
380 s->vhost_net = NULL;
381
382 s->exit.notify = tap_exit_notify;
383 qemu_add_exit_notifier(&s->exit);
384
385 return s;
386 }
387
launch_script(const char * setup_script,const char * ifname,int fd,Error ** errp)388 static void launch_script(const char *setup_script, const char *ifname,
389 int fd, Error **errp)
390 {
391 int pid, status;
392 char *args[3];
393 char **parg;
394
395 /* try to launch network script */
396 pid = fork();
397 if (pid < 0) {
398 error_setg_errno(errp, errno, "could not launch network script %s",
399 setup_script);
400 return;
401 }
402 if (pid == 0) {
403 int open_max = sysconf(_SC_OPEN_MAX), i;
404
405 for (i = 3; i < open_max; i++) {
406 if (i != fd) {
407 close(i);
408 }
409 }
410 parg = args;
411 *parg++ = (char *)setup_script;
412 *parg++ = (char *)ifname;
413 *parg = NULL;
414 execv(setup_script, args);
415 _exit(1);
416 } else {
417 while (waitpid(pid, &status, 0) != pid) {
418 /* loop */
419 }
420
421 if (WIFEXITED(status) && WEXITSTATUS(status) == 0) {
422 return;
423 }
424 error_setg(errp, "network script %s failed with status %d",
425 setup_script, status);
426 }
427 }
428
recv_fd(int c)429 static int recv_fd(int c)
430 {
431 int fd;
432 uint8_t msgbuf[CMSG_SPACE(sizeof(fd))];
433 struct msghdr msg = {
434 .msg_control = msgbuf,
435 .msg_controllen = sizeof(msgbuf),
436 };
437 struct cmsghdr *cmsg;
438 struct iovec iov;
439 uint8_t req[1];
440 ssize_t len;
441
442 cmsg = CMSG_FIRSTHDR(&msg);
443 cmsg->cmsg_level = SOL_SOCKET;
444 cmsg->cmsg_type = SCM_RIGHTS;
445 cmsg->cmsg_len = CMSG_LEN(sizeof(fd));
446 msg.msg_controllen = cmsg->cmsg_len;
447
448 iov.iov_base = req;
449 iov.iov_len = sizeof(req);
450
451 msg.msg_iov = &iov;
452 msg.msg_iovlen = 1;
453
454 len = recvmsg(c, &msg, 0);
455 if (len > 0) {
456 memcpy(&fd, CMSG_DATA(cmsg), sizeof(fd));
457 return fd;
458 }
459
460 return len;
461 }
462
net_bridge_run_helper(const char * helper,const char * bridge,Error ** errp)463 static int net_bridge_run_helper(const char *helper, const char *bridge,
464 Error **errp)
465 {
466 sigset_t oldmask, mask;
467 g_autofree char *default_helper = NULL;
468 int pid, status;
469 char *args[5];
470 char **parg;
471 int sv[2];
472
473 sigemptyset(&mask);
474 sigaddset(&mask, SIGCHLD);
475 sigprocmask(SIG_BLOCK, &mask, &oldmask);
476
477 if (!helper) {
478 helper = default_helper = get_relocated_path(DEFAULT_BRIDGE_HELPER);
479 }
480
481 if (socketpair(PF_UNIX, SOCK_STREAM, 0, sv) == -1) {
482 error_setg_errno(errp, errno, "socketpair() failed");
483 return -1;
484 }
485
486 /* try to launch bridge helper */
487 pid = fork();
488 if (pid < 0) {
489 error_setg_errno(errp, errno, "Can't fork bridge helper");
490 return -1;
491 }
492 if (pid == 0) {
493 int open_max = sysconf(_SC_OPEN_MAX), i;
494 char *fd_buf = NULL;
495 char *br_buf = NULL;
496 char *helper_cmd = NULL;
497
498 for (i = 3; i < open_max; i++) {
499 if (i != sv[1]) {
500 close(i);
501 }
502 }
503
504 fd_buf = g_strdup_printf("%s%d", "--fd=", sv[1]);
505
506 if (strrchr(helper, ' ') || strrchr(helper, '\t')) {
507 /* assume helper is a command */
508
509 if (strstr(helper, "--br=") == NULL) {
510 br_buf = g_strdup_printf("%s%s", "--br=", bridge);
511 }
512
513 helper_cmd = g_strdup_printf("%s %s %s %s", helper,
514 "--use-vnet", fd_buf, br_buf ? br_buf : "");
515
516 parg = args;
517 *parg++ = (char *)"sh";
518 *parg++ = (char *)"-c";
519 *parg++ = helper_cmd;
520 *parg++ = NULL;
521
522 execv("/bin/sh", args);
523 g_free(helper_cmd);
524 } else {
525 /* assume helper is just the executable path name */
526
527 br_buf = g_strdup_printf("%s%s", "--br=", bridge);
528
529 parg = args;
530 *parg++ = (char *)helper;
531 *parg++ = (char *)"--use-vnet";
532 *parg++ = fd_buf;
533 *parg++ = br_buf;
534 *parg++ = NULL;
535
536 execv(helper, args);
537 }
538 g_free(fd_buf);
539 g_free(br_buf);
540 _exit(1);
541
542 } else {
543 int fd;
544 int saved_errno;
545
546 close(sv[1]);
547
548 fd = RETRY_ON_EINTR(recv_fd(sv[0]));
549 saved_errno = errno;
550
551 close(sv[0]);
552
553 while (waitpid(pid, &status, 0) != pid) {
554 /* loop */
555 }
556 sigprocmask(SIG_SETMASK, &oldmask, NULL);
557 if (fd < 0) {
558 error_setg_errno(errp, saved_errno,
559 "failed to recv file descriptor");
560 return -1;
561 }
562 if (!WIFEXITED(status) || WEXITSTATUS(status) != 0) {
563 error_setg(errp, "bridge helper failed");
564 return -1;
565 }
566 return fd;
567 }
568 }
569
net_init_bridge(const Netdev * netdev,const char * name,NetClientState * peer,Error ** errp)570 int net_init_bridge(const Netdev *netdev, const char *name,
571 NetClientState *peer, Error **errp)
572 {
573 const NetdevBridgeOptions *bridge;
574 const char *helper, *br;
575 TAPState *s;
576 int fd, vnet_hdr;
577
578 assert(netdev->type == NET_CLIENT_DRIVER_BRIDGE);
579 bridge = &netdev->u.bridge;
580 helper = bridge->helper;
581 br = bridge->br ?: DEFAULT_BRIDGE_INTERFACE;
582
583 fd = net_bridge_run_helper(helper, br, errp);
584 if (fd == -1) {
585 return -1;
586 }
587
588 if (!g_unix_set_fd_nonblocking(fd, true, NULL)) {
589 error_setg_errno(errp, errno, "Failed to set FD nonblocking");
590 return -1;
591 }
592 vnet_hdr = tap_probe_vnet_hdr(fd, errp);
593 if (vnet_hdr < 0) {
594 close(fd);
595 return -1;
596 }
597 s = net_tap_fd_init(peer, "bridge", name, fd, vnet_hdr);
598
599 qemu_set_info_str(&s->nc, "helper=%s,br=%s", helper, br);
600
601 return 0;
602 }
603
net_tap_init(const NetdevTapOptions * tap,int * vnet_hdr,const char * setup_script,char * ifname,size_t ifname_sz,int mq_required,Error ** errp)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 fd = RETRY_ON_EINTR(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
net_init_tap_one(const NetdevTapOptions * tap,NetClientState * peer,const char * model,const char * name,const char * ifname,const char * script,const char * downscript,const char * vhostfdname,int vnet_hdr,int fd,Error ** errp)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 goto failed;
655 }
656
657 if (tap->fd || tap->fds) {
658 qemu_set_info_str(&s->nc, "fd=%d", fd);
659 } else if (tap->helper) {
660 qemu_set_info_str(&s->nc, "helper=%s", tap->helper);
661 } else {
662 qemu_set_info_str(&s->nc, "ifname=%s,script=%s,downscript=%s", ifname,
663 script, downscript);
664
665 if (strcmp(downscript, "no") != 0) {
666 snprintf(s->down_script, sizeof(s->down_script), "%s", downscript);
667 snprintf(s->down_script_arg, sizeof(s->down_script_arg),
668 "%s", ifname);
669 }
670 }
671
672 if (tap->has_vhost ? tap->vhost :
673 vhostfdname || (tap->has_vhostforce && tap->vhostforce)) {
674 VhostNetOptions options;
675
676 options.backend_type = VHOST_BACKEND_TYPE_KERNEL;
677 options.net_backend = &s->nc;
678 if (tap->has_poll_us) {
679 options.busyloop_timeout = tap->poll_us;
680 } else {
681 options.busyloop_timeout = 0;
682 }
683
684 if (vhostfdname) {
685 vhostfd = monitor_fd_param(monitor_cur(), vhostfdname, &err);
686 if (vhostfd == -1) {
687 error_propagate(errp, err);
688 goto failed;
689 }
690 if (!g_unix_set_fd_nonblocking(vhostfd, true, NULL)) {
691 error_setg_errno(errp, errno, "%s: Can't use file descriptor %d",
692 name, fd);
693 goto failed;
694 }
695 } else {
696 vhostfd = open("/dev/vhost-net", O_RDWR);
697 if (vhostfd < 0) {
698 error_setg_errno(errp, errno,
699 "tap: open vhost char device failed");
700 goto failed;
701 }
702 if (!g_unix_set_fd_nonblocking(vhostfd, true, NULL)) {
703 error_setg_errno(errp, errno, "Failed to set FD nonblocking");
704 goto failed;
705 }
706 }
707 options.opaque = (void *)(uintptr_t)vhostfd;
708 options.nvqs = 2;
709
710 s->vhost_net = vhost_net_init(&options);
711 if (!s->vhost_net) {
712 error_setg(errp,
713 "vhost-net requested but could not be initialized");
714 goto failed;
715 }
716 } else if (vhostfdname) {
717 error_setg(errp, "vhostfd(s)= is not valid without vhost");
718 goto failed;
719 }
720
721 return;
722
723 failed:
724 qemu_del_net_client(&s->nc);
725 }
726
get_fds(char * str,char * fds[],int max)727 static int get_fds(char *str, char *fds[], int max)
728 {
729 char *ptr = str, *this;
730 size_t len = strlen(str);
731 int i = 0;
732
733 while (i < max && ptr < str + len) {
734 this = strchr(ptr, ':');
735
736 if (this == NULL) {
737 fds[i] = g_strdup(ptr);
738 } else {
739 fds[i] = g_strndup(ptr, this - ptr);
740 }
741
742 i++;
743 if (this == NULL) {
744 break;
745 } else {
746 ptr = this + 1;
747 }
748 }
749
750 return i;
751 }
752
net_init_tap(const Netdev * netdev,const char * name,NetClientState * peer,Error ** errp)753 int net_init_tap(const Netdev *netdev, const char *name,
754 NetClientState *peer, Error **errp)
755 {
756 const NetdevTapOptions *tap;
757 int fd, vnet_hdr = 0, i = 0, queues;
758 /* for the no-fd, no-helper case */
759 const char *script;
760 const char *downscript;
761 Error *err = NULL;
762 const char *vhostfdname;
763 char ifname[128];
764 int ret = 0;
765
766 assert(netdev->type == NET_CLIENT_DRIVER_TAP);
767 tap = &netdev->u.tap;
768 queues = tap->has_queues ? tap->queues : 1;
769 vhostfdname = tap->vhostfd;
770 script = tap->script;
771 downscript = tap->downscript;
772
773 /* QEMU hubs do not support multiqueue tap, in this case peer is set.
774 * For -netdev, peer is always NULL. */
775 if (peer && (tap->has_queues || tap->fds || tap->vhostfds)) {
776 error_setg(errp, "Multiqueue tap cannot be used with hubs");
777 return -1;
778 }
779
780 if (tap->fd) {
781 if (tap->ifname || tap->script || tap->downscript ||
782 tap->has_vnet_hdr || tap->helper || tap->has_queues ||
783 tap->fds || tap->vhostfds) {
784 error_setg(errp, "ifname=, script=, downscript=, vnet_hdr=, "
785 "helper=, queues=, fds=, and vhostfds= "
786 "are invalid with fd=");
787 return -1;
788 }
789
790 fd = monitor_fd_param(monitor_cur(), tap->fd, errp);
791 if (fd == -1) {
792 return -1;
793 }
794
795 if (!g_unix_set_fd_nonblocking(fd, true, NULL)) {
796 error_setg_errno(errp, errno, "%s: Can't use file descriptor %d",
797 name, fd);
798 close(fd);
799 return -1;
800 }
801
802 vnet_hdr = tap_probe_vnet_hdr(fd, errp);
803 if (vnet_hdr < 0) {
804 close(fd);
805 return -1;
806 }
807
808 net_init_tap_one(tap, peer, "tap", name, NULL,
809 script, downscript,
810 vhostfdname, vnet_hdr, fd, &err);
811 if (err) {
812 error_propagate(errp, err);
813 close(fd);
814 return -1;
815 }
816 } else if (tap->fds) {
817 char **fds;
818 char **vhost_fds;
819 int nfds = 0, nvhosts = 0;
820
821 if (tap->ifname || tap->script || tap->downscript ||
822 tap->has_vnet_hdr || tap->helper || tap->has_queues ||
823 tap->vhostfd) {
824 error_setg(errp, "ifname=, script=, downscript=, vnet_hdr=, "
825 "helper=, queues=, and vhostfd= "
826 "are invalid with fds=");
827 return -1;
828 }
829
830 fds = g_new0(char *, MAX_TAP_QUEUES);
831 vhost_fds = g_new0(char *, MAX_TAP_QUEUES);
832
833 nfds = get_fds(tap->fds, fds, MAX_TAP_QUEUES);
834 if (tap->vhostfds) {
835 nvhosts = get_fds(tap->vhostfds, vhost_fds, MAX_TAP_QUEUES);
836 if (nfds != nvhosts) {
837 error_setg(errp, "The number of fds passed does not match "
838 "the number of vhostfds passed");
839 ret = -1;
840 goto free_fail;
841 }
842 }
843
844 for (i = 0; i < nfds; i++) {
845 fd = monitor_fd_param(monitor_cur(), fds[i], errp);
846 if (fd == -1) {
847 ret = -1;
848 goto free_fail;
849 }
850
851 ret = g_unix_set_fd_nonblocking(fd, true, NULL);
852 if (!ret) {
853 error_setg_errno(errp, errno, "%s: Can't use file descriptor %d",
854 name, fd);
855 goto free_fail;
856 }
857
858 if (i == 0) {
859 vnet_hdr = tap_probe_vnet_hdr(fd, errp);
860 if (vnet_hdr < 0) {
861 ret = -1;
862 goto free_fail;
863 }
864 } else if (vnet_hdr != tap_probe_vnet_hdr(fd, NULL)) {
865 error_setg(errp,
866 "vnet_hdr not consistent across given tap fds");
867 ret = -1;
868 goto free_fail;
869 }
870
871 net_init_tap_one(tap, peer, "tap", name, ifname,
872 script, downscript,
873 tap->vhostfds ? vhost_fds[i] : NULL,
874 vnet_hdr, fd, &err);
875 if (err) {
876 error_propagate(errp, err);
877 ret = -1;
878 goto free_fail;
879 }
880 }
881
882 free_fail:
883 for (i = 0; i < nvhosts; i++) {
884 g_free(vhost_fds[i]);
885 }
886 for (i = 0; i < nfds; i++) {
887 g_free(fds[i]);
888 }
889 g_free(fds);
890 g_free(vhost_fds);
891 return ret;
892 } else if (tap->helper) {
893 if (tap->ifname || tap->script || tap->downscript ||
894 tap->has_vnet_hdr || tap->has_queues || tap->vhostfds) {
895 error_setg(errp, "ifname=, script=, downscript=, vnet_hdr=, "
896 "queues=, and vhostfds= are invalid with helper=");
897 return -1;
898 }
899
900 fd = net_bridge_run_helper(tap->helper,
901 tap->br ?: DEFAULT_BRIDGE_INTERFACE,
902 errp);
903 if (fd == -1) {
904 return -1;
905 }
906
907 if (!g_unix_set_fd_nonblocking(fd, true, NULL)) {
908 error_setg_errno(errp, errno, "Failed to set FD nonblocking");
909 return -1;
910 }
911 vnet_hdr = tap_probe_vnet_hdr(fd, errp);
912 if (vnet_hdr < 0) {
913 close(fd);
914 return -1;
915 }
916
917 net_init_tap_one(tap, peer, "bridge", name, ifname,
918 script, downscript, vhostfdname,
919 vnet_hdr, fd, &err);
920 if (err) {
921 error_propagate(errp, err);
922 close(fd);
923 return -1;
924 }
925 } else {
926 g_autofree char *default_script = NULL;
927 g_autofree char *default_downscript = NULL;
928 if (tap->vhostfds) {
929 error_setg(errp, "vhostfds= is invalid if fds= wasn't specified");
930 return -1;
931 }
932
933 if (!script) {
934 script = default_script = get_relocated_path(DEFAULT_NETWORK_SCRIPT);
935 }
936 if (!downscript) {
937 downscript = default_downscript =
938 get_relocated_path(DEFAULT_NETWORK_DOWN_SCRIPT);
939 }
940
941 if (tap->ifname) {
942 pstrcpy(ifname, sizeof ifname, tap->ifname);
943 } else {
944 ifname[0] = '\0';
945 }
946
947 for (i = 0; i < queues; i++) {
948 fd = net_tap_init(tap, &vnet_hdr, i >= 1 ? "no" : script,
949 ifname, sizeof ifname, queues > 1, errp);
950 if (fd == -1) {
951 return -1;
952 }
953
954 if (queues > 1 && i == 0 && !tap->ifname) {
955 if (tap_fd_get_ifname(fd, ifname)) {
956 error_setg(errp, "Fail to get ifname");
957 close(fd);
958 return -1;
959 }
960 }
961
962 net_init_tap_one(tap, peer, "tap", name, ifname,
963 i >= 1 ? "no" : script,
964 i >= 1 ? "no" : downscript,
965 vhostfdname, vnet_hdr, fd, &err);
966 if (err) {
967 error_propagate(errp, err);
968 close(fd);
969 return -1;
970 }
971 }
972 }
973
974 return 0;
975 }
976
tap_get_vhost_net(NetClientState * nc)977 VHostNetState *tap_get_vhost_net(NetClientState *nc)
978 {
979 TAPState *s = DO_UPCAST(TAPState, nc, nc);
980 assert(nc->info->type == NET_CLIENT_DRIVER_TAP);
981 return s->vhost_net;
982 }
983
tap_enable(NetClientState * nc)984 int tap_enable(NetClientState *nc)
985 {
986 TAPState *s = DO_UPCAST(TAPState, nc, nc);
987 int ret;
988
989 if (s->enabled) {
990 return 0;
991 } else {
992 ret = tap_fd_enable(s->fd);
993 if (ret == 0) {
994 s->enabled = true;
995 tap_update_fd_handler(s);
996 }
997 return ret;
998 }
999 }
1000
tap_disable(NetClientState * nc)1001 int tap_disable(NetClientState *nc)
1002 {
1003 TAPState *s = DO_UPCAST(TAPState, nc, nc);
1004 int ret;
1005
1006 if (s->enabled == 0) {
1007 return 0;
1008 } else {
1009 ret = tap_fd_disable(s->fd);
1010 if (ret == 0) {
1011 qemu_purge_queued_packets(nc);
1012 s->enabled = false;
1013 tap_update_fd_handler(s);
1014 }
1015 return ret;
1016 }
1017 }
1018