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
close_all_fds_after_fork(int excluded_fd)388 static void close_all_fds_after_fork(int excluded_fd)
389 {
390 const int skip_fd[] = {STDIN_FILENO, STDOUT_FILENO, STDERR_FILENO,
391 excluded_fd};
392 unsigned int nskip = ARRAY_SIZE(skip_fd);
393
394 /*
395 * skip_fd must be an ordered array of distinct fds, exclude
396 * excluded_fd if already included in the [STDIN_FILENO - STDERR_FILENO]
397 * range
398 */
399 if (excluded_fd <= STDERR_FILENO) {
400 nskip--;
401 }
402
403 qemu_close_all_open_fd(skip_fd, nskip);
404 }
405
launch_script(const char * setup_script,const char * ifname,int fd,Error ** errp)406 static void launch_script(const char *setup_script, const char *ifname,
407 int fd, Error **errp)
408 {
409 int pid, status;
410 char *args[3];
411 char **parg;
412
413 /* try to launch network script */
414 pid = fork();
415 if (pid < 0) {
416 error_setg_errno(errp, errno, "could not launch network script %s",
417 setup_script);
418 return;
419 }
420 if (pid == 0) {
421 close_all_fds_after_fork(fd);
422 parg = args;
423 *parg++ = (char *)setup_script;
424 *parg++ = (char *)ifname;
425 *parg = NULL;
426 execv(setup_script, args);
427 _exit(1);
428 } else {
429 while (waitpid(pid, &status, 0) != pid) {
430 /* loop */
431 }
432
433 if (WIFEXITED(status) && WEXITSTATUS(status) == 0) {
434 return;
435 }
436 error_setg(errp, "network script %s failed with status %d",
437 setup_script, status);
438 }
439 }
440
recv_fd(int c)441 static int recv_fd(int c)
442 {
443 int fd;
444 uint8_t msgbuf[CMSG_SPACE(sizeof(fd))];
445 struct msghdr msg = {
446 .msg_control = msgbuf,
447 .msg_controllen = sizeof(msgbuf),
448 };
449 struct cmsghdr *cmsg;
450 struct iovec iov;
451 uint8_t req[1];
452 ssize_t len;
453
454 cmsg = CMSG_FIRSTHDR(&msg);
455 cmsg->cmsg_level = SOL_SOCKET;
456 cmsg->cmsg_type = SCM_RIGHTS;
457 cmsg->cmsg_len = CMSG_LEN(sizeof(fd));
458 msg.msg_controllen = cmsg->cmsg_len;
459
460 iov.iov_base = req;
461 iov.iov_len = sizeof(req);
462
463 msg.msg_iov = &iov;
464 msg.msg_iovlen = 1;
465
466 len = recvmsg(c, &msg, 0);
467 if (len > 0) {
468 memcpy(&fd, CMSG_DATA(cmsg), sizeof(fd));
469 return fd;
470 }
471
472 return len;
473 }
474
net_bridge_run_helper(const char * helper,const char * bridge,Error ** errp)475 static int net_bridge_run_helper(const char *helper, const char *bridge,
476 Error **errp)
477 {
478 sigset_t oldmask, mask;
479 g_autofree char *default_helper = NULL;
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 (!helper) {
490 helper = default_helper = get_relocated_path(DEFAULT_BRIDGE_HELPER);
491 }
492
493 if (socketpair(PF_UNIX, SOCK_STREAM, 0, sv) == -1) {
494 error_setg_errno(errp, errno, "socketpair() failed");
495 return -1;
496 }
497
498 /* try to launch bridge helper */
499 pid = fork();
500 if (pid < 0) {
501 error_setg_errno(errp, errno, "Can't fork bridge helper");
502 return -1;
503 }
504 if (pid == 0) {
505 char *fd_buf = NULL;
506 char *br_buf = NULL;
507 char *helper_cmd = NULL;
508
509 close_all_fds_after_fork(sv[1]);
510 fd_buf = g_strdup_printf("%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 br_buf = g_strdup_printf("%s%s", "--br=", bridge);
517 }
518
519 helper_cmd = g_strdup_printf("%s %s %s %s", helper,
520 "--use-vnet", fd_buf, br_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 g_free(helper_cmd);
530 } else {
531 /* assume helper is just the executable path name */
532
533 br_buf = g_strdup_printf("%s%s", "--br=", bridge);
534
535 parg = args;
536 *parg++ = (char *)helper;
537 *parg++ = (char *)"--use-vnet";
538 *parg++ = fd_buf;
539 *parg++ = br_buf;
540 *parg++ = NULL;
541
542 execv(helper, args);
543 }
544 g_free(fd_buf);
545 g_free(br_buf);
546 _exit(1);
547
548 } else {
549 int fd;
550 int saved_errno;
551
552 close(sv[1]);
553
554 fd = RETRY_ON_EINTR(recv_fd(sv[0]));
555 saved_errno = errno;
556
557 close(sv[0]);
558
559 while (waitpid(pid, &status, 0) != pid) {
560 /* loop */
561 }
562 sigprocmask(SIG_SETMASK, &oldmask, NULL);
563 if (fd < 0) {
564 error_setg_errno(errp, saved_errno,
565 "failed to recv file descriptor");
566 return -1;
567 }
568 if (!WIFEXITED(status) || WEXITSTATUS(status) != 0) {
569 error_setg(errp, "bridge helper failed");
570 return -1;
571 }
572 return fd;
573 }
574 }
575
net_init_bridge(const Netdev * netdev,const char * name,NetClientState * peer,Error ** errp)576 int net_init_bridge(const Netdev *netdev, const char *name,
577 NetClientState *peer, Error **errp)
578 {
579 const NetdevBridgeOptions *bridge;
580 const char *helper, *br;
581 TAPState *s;
582 int fd, vnet_hdr;
583
584 assert(netdev->type == NET_CLIENT_DRIVER_BRIDGE);
585 bridge = &netdev->u.bridge;
586 helper = bridge->helper;
587 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 if (!g_unix_set_fd_nonblocking(fd, true, NULL)) {
595 error_setg_errno(errp, errno, "Failed to set FD nonblocking");
596 return -1;
597 }
598 vnet_hdr = tap_probe_vnet_hdr(fd, errp);
599 if (vnet_hdr < 0) {
600 close(fd);
601 return -1;
602 }
603 s = net_tap_fd_init(peer, "bridge", name, fd, vnet_hdr);
604
605 qemu_set_info_str(&s->nc, "helper=%s,br=%s", helper, br);
606
607 return 0;
608 }
609
net_tap_init(const NetdevTapOptions * tap,int * vnet_hdr,const char * setup_script,char * ifname,size_t ifname_sz,int mq_required,Error ** errp)610 static int net_tap_init(const NetdevTapOptions *tap, int *vnet_hdr,
611 const char *setup_script, char *ifname,
612 size_t ifname_sz, int mq_required, Error **errp)
613 {
614 Error *err = NULL;
615 int fd, vnet_hdr_required;
616
617 if (tap->has_vnet_hdr) {
618 *vnet_hdr = tap->vnet_hdr;
619 vnet_hdr_required = *vnet_hdr;
620 } else {
621 *vnet_hdr = 1;
622 vnet_hdr_required = 0;
623 }
624
625 fd = RETRY_ON_EINTR(tap_open(ifname, ifname_sz, vnet_hdr, vnet_hdr_required,
626 mq_required, errp));
627 if (fd < 0) {
628 return -1;
629 }
630
631 if (setup_script &&
632 setup_script[0] != '\0' &&
633 strcmp(setup_script, "no") != 0) {
634 launch_script(setup_script, ifname, fd, &err);
635 if (err) {
636 error_propagate(errp, err);
637 close(fd);
638 return -1;
639 }
640 }
641
642 return fd;
643 }
644
645 #define MAX_TAP_QUEUES 1024
646
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)647 static void net_init_tap_one(const NetdevTapOptions *tap, NetClientState *peer,
648 const char *model, const char *name,
649 const char *ifname, const char *script,
650 const char *downscript, const char *vhostfdname,
651 int vnet_hdr, int fd, Error **errp)
652 {
653 Error *err = NULL;
654 TAPState *s = net_tap_fd_init(peer, model, name, fd, vnet_hdr);
655 int vhostfd;
656
657 tap_set_sndbuf(s->fd, tap, &err);
658 if (err) {
659 error_propagate(errp, err);
660 goto failed;
661 }
662
663 if (tap->fd || tap->fds) {
664 qemu_set_info_str(&s->nc, "fd=%d", fd);
665 } else if (tap->helper) {
666 qemu_set_info_str(&s->nc, "helper=%s", tap->helper);
667 } else {
668 qemu_set_info_str(&s->nc, "ifname=%s,script=%s,downscript=%s", ifname,
669 script, downscript);
670
671 if (strcmp(downscript, "no") != 0) {
672 snprintf(s->down_script, sizeof(s->down_script), "%s", downscript);
673 snprintf(s->down_script_arg, sizeof(s->down_script_arg),
674 "%s", ifname);
675 }
676 }
677
678 if (tap->has_vhost ? tap->vhost :
679 vhostfdname || (tap->has_vhostforce && tap->vhostforce)) {
680 VhostNetOptions options;
681
682 options.backend_type = VHOST_BACKEND_TYPE_KERNEL;
683 options.net_backend = &s->nc;
684 if (tap->has_poll_us) {
685 options.busyloop_timeout = tap->poll_us;
686 } else {
687 options.busyloop_timeout = 0;
688 }
689
690 if (vhostfdname) {
691 vhostfd = monitor_fd_param(monitor_cur(), vhostfdname, &err);
692 if (vhostfd == -1) {
693 error_propagate(errp, err);
694 goto failed;
695 }
696 if (!g_unix_set_fd_nonblocking(vhostfd, true, NULL)) {
697 error_setg_errno(errp, errno, "%s: Can't use file descriptor %d",
698 name, fd);
699 goto failed;
700 }
701 } else {
702 vhostfd = open("/dev/vhost-net", O_RDWR);
703 if (vhostfd < 0) {
704 error_setg_errno(errp, errno,
705 "tap: open vhost char device failed");
706 goto failed;
707 }
708 if (!g_unix_set_fd_nonblocking(vhostfd, true, NULL)) {
709 error_setg_errno(errp, errno, "Failed to set FD nonblocking");
710 goto failed;
711 }
712 }
713 options.opaque = (void *)(uintptr_t)vhostfd;
714 options.nvqs = 2;
715
716 s->vhost_net = vhost_net_init(&options);
717 if (!s->vhost_net) {
718 error_setg(errp,
719 "vhost-net requested but could not be initialized");
720 goto failed;
721 }
722 } else if (vhostfdname) {
723 error_setg(errp, "vhostfd(s)= is not valid without vhost");
724 goto failed;
725 }
726
727 return;
728
729 failed:
730 qemu_del_net_client(&s->nc);
731 }
732
get_fds(char * str,char * fds[],int max)733 static int get_fds(char *str, char *fds[], int max)
734 {
735 char *ptr = str, *this;
736 size_t len = strlen(str);
737 int i = 0;
738
739 while (i < max && ptr < str + len) {
740 this = strchr(ptr, ':');
741
742 if (this == NULL) {
743 fds[i] = g_strdup(ptr);
744 } else {
745 fds[i] = g_strndup(ptr, this - ptr);
746 }
747
748 i++;
749 if (this == NULL) {
750 break;
751 } else {
752 ptr = this + 1;
753 }
754 }
755
756 return i;
757 }
758
net_init_tap(const Netdev * netdev,const char * name,NetClientState * peer,Error ** errp)759 int net_init_tap(const Netdev *netdev, const char *name,
760 NetClientState *peer, Error **errp)
761 {
762 const NetdevTapOptions *tap;
763 int fd, vnet_hdr = 0, i = 0, queues;
764 /* for the no-fd, no-helper case */
765 const char *script;
766 const char *downscript;
767 Error *err = NULL;
768 const char *vhostfdname;
769 char ifname[128];
770 int ret = 0;
771
772 assert(netdev->type == NET_CLIENT_DRIVER_TAP);
773 tap = &netdev->u.tap;
774 queues = tap->has_queues ? tap->queues : 1;
775 vhostfdname = tap->vhostfd;
776 script = tap->script;
777 downscript = tap->downscript;
778
779 /* QEMU hubs do not support multiqueue tap, in this case peer is set.
780 * For -netdev, peer is always NULL. */
781 if (peer && (tap->has_queues || tap->fds || tap->vhostfds)) {
782 error_setg(errp, "Multiqueue tap cannot be used with hubs");
783 return -1;
784 }
785
786 if (tap->fd) {
787 if (tap->ifname || tap->script || tap->downscript ||
788 tap->has_vnet_hdr || tap->helper || tap->has_queues ||
789 tap->fds || tap->vhostfds) {
790 error_setg(errp, "ifname=, script=, downscript=, vnet_hdr=, "
791 "helper=, queues=, fds=, and vhostfds= "
792 "are invalid with fd=");
793 return -1;
794 }
795
796 fd = monitor_fd_param(monitor_cur(), tap->fd, errp);
797 if (fd == -1) {
798 return -1;
799 }
800
801 if (!g_unix_set_fd_nonblocking(fd, true, NULL)) {
802 error_setg_errno(errp, errno, "%s: Can't use file descriptor %d",
803 name, fd);
804 close(fd);
805 return -1;
806 }
807
808 vnet_hdr = tap_probe_vnet_hdr(fd, errp);
809 if (vnet_hdr < 0) {
810 close(fd);
811 return -1;
812 }
813
814 net_init_tap_one(tap, peer, "tap", name, NULL,
815 script, downscript,
816 vhostfdname, vnet_hdr, fd, &err);
817 if (err) {
818 error_propagate(errp, err);
819 close(fd);
820 return -1;
821 }
822 } else if (tap->fds) {
823 char **fds;
824 char **vhost_fds;
825 int nfds = 0, nvhosts = 0;
826
827 if (tap->ifname || tap->script || tap->downscript ||
828 tap->has_vnet_hdr || tap->helper || tap->has_queues ||
829 tap->vhostfd) {
830 error_setg(errp, "ifname=, script=, downscript=, vnet_hdr=, "
831 "helper=, queues=, and vhostfd= "
832 "are invalid with fds=");
833 return -1;
834 }
835
836 fds = g_new0(char *, MAX_TAP_QUEUES);
837 vhost_fds = g_new0(char *, MAX_TAP_QUEUES);
838
839 nfds = get_fds(tap->fds, fds, MAX_TAP_QUEUES);
840 if (tap->vhostfds) {
841 nvhosts = get_fds(tap->vhostfds, vhost_fds, MAX_TAP_QUEUES);
842 if (nfds != nvhosts) {
843 error_setg(errp, "The number of fds passed does not match "
844 "the number of vhostfds passed");
845 ret = -1;
846 goto free_fail;
847 }
848 }
849
850 for (i = 0; i < nfds; i++) {
851 fd = monitor_fd_param(monitor_cur(), fds[i], errp);
852 if (fd == -1) {
853 ret = -1;
854 goto free_fail;
855 }
856
857 ret = g_unix_set_fd_nonblocking(fd, true, NULL);
858 if (!ret) {
859 error_setg_errno(errp, errno, "%s: Can't use file descriptor %d",
860 name, fd);
861 goto free_fail;
862 }
863
864 if (i == 0) {
865 vnet_hdr = tap_probe_vnet_hdr(fd, errp);
866 if (vnet_hdr < 0) {
867 ret = -1;
868 goto free_fail;
869 }
870 } else if (vnet_hdr != tap_probe_vnet_hdr(fd, NULL)) {
871 error_setg(errp,
872 "vnet_hdr not consistent across given tap fds");
873 ret = -1;
874 goto free_fail;
875 }
876
877 net_init_tap_one(tap, peer, "tap", name, ifname,
878 script, downscript,
879 tap->vhostfds ? vhost_fds[i] : NULL,
880 vnet_hdr, fd, &err);
881 if (err) {
882 error_propagate(errp, err);
883 ret = -1;
884 goto free_fail;
885 }
886 }
887
888 free_fail:
889 for (i = 0; i < nvhosts; i++) {
890 g_free(vhost_fds[i]);
891 }
892 for (i = 0; i < nfds; i++) {
893 g_free(fds[i]);
894 }
895 g_free(fds);
896 g_free(vhost_fds);
897 return ret;
898 } else if (tap->helper) {
899 if (tap->ifname || tap->script || tap->downscript ||
900 tap->has_vnet_hdr || tap->has_queues || tap->vhostfds) {
901 error_setg(errp, "ifname=, script=, downscript=, vnet_hdr=, "
902 "queues=, and vhostfds= are invalid with helper=");
903 return -1;
904 }
905
906 fd = net_bridge_run_helper(tap->helper,
907 tap->br ?: DEFAULT_BRIDGE_INTERFACE,
908 errp);
909 if (fd == -1) {
910 return -1;
911 }
912
913 if (!g_unix_set_fd_nonblocking(fd, true, NULL)) {
914 error_setg_errno(errp, errno, "Failed to set FD nonblocking");
915 return -1;
916 }
917 vnet_hdr = tap_probe_vnet_hdr(fd, errp);
918 if (vnet_hdr < 0) {
919 close(fd);
920 return -1;
921 }
922
923 net_init_tap_one(tap, peer, "bridge", name, ifname,
924 script, downscript, vhostfdname,
925 vnet_hdr, fd, &err);
926 if (err) {
927 error_propagate(errp, err);
928 close(fd);
929 return -1;
930 }
931 } else {
932 g_autofree char *default_script = NULL;
933 g_autofree char *default_downscript = NULL;
934 if (tap->vhostfds) {
935 error_setg(errp, "vhostfds= is invalid if fds= wasn't specified");
936 return -1;
937 }
938
939 if (!script) {
940 script = default_script = get_relocated_path(DEFAULT_NETWORK_SCRIPT);
941 }
942 if (!downscript) {
943 downscript = default_downscript =
944 get_relocated_path(DEFAULT_NETWORK_DOWN_SCRIPT);
945 }
946
947 if (tap->ifname) {
948 pstrcpy(ifname, sizeof ifname, tap->ifname);
949 } else {
950 ifname[0] = '\0';
951 }
952
953 for (i = 0; i < queues; i++) {
954 fd = net_tap_init(tap, &vnet_hdr, i >= 1 ? "no" : script,
955 ifname, sizeof ifname, queues > 1, errp);
956 if (fd == -1) {
957 return -1;
958 }
959
960 if (queues > 1 && i == 0 && !tap->ifname) {
961 if (tap_fd_get_ifname(fd, ifname)) {
962 error_setg(errp, "Fail to get ifname");
963 close(fd);
964 return -1;
965 }
966 }
967
968 net_init_tap_one(tap, peer, "tap", name, ifname,
969 i >= 1 ? "no" : script,
970 i >= 1 ? "no" : downscript,
971 vhostfdname, vnet_hdr, fd, &err);
972 if (err) {
973 error_propagate(errp, err);
974 close(fd);
975 return -1;
976 }
977 }
978 }
979
980 return 0;
981 }
982
tap_get_vhost_net(NetClientState * nc)983 VHostNetState *tap_get_vhost_net(NetClientState *nc)
984 {
985 TAPState *s = DO_UPCAST(TAPState, nc, nc);
986 assert(nc->info->type == NET_CLIENT_DRIVER_TAP);
987 return s->vhost_net;
988 }
989
tap_enable(NetClientState * nc)990 int tap_enable(NetClientState *nc)
991 {
992 TAPState *s = DO_UPCAST(TAPState, nc, nc);
993 int ret;
994
995 if (s->enabled) {
996 return 0;
997 } else {
998 ret = tap_fd_enable(s->fd);
999 if (ret == 0) {
1000 s->enabled = true;
1001 tap_update_fd_handler(s);
1002 }
1003 return ret;
1004 }
1005 }
1006
tap_disable(NetClientState * nc)1007 int tap_disable(NetClientState *nc)
1008 {
1009 TAPState *s = DO_UPCAST(TAPState, nc, nc);
1010 int ret;
1011
1012 if (s->enabled == 0) {
1013 return 0;
1014 } else {
1015 ret = tap_fd_disable(s->fd);
1016 if (ret == 0) {
1017 qemu_purge_queued_packets(nc);
1018 s->enabled = false;
1019 tap_update_fd_handler(s);
1020 }
1021 return ret;
1022 }
1023 }
1024