KVM: Update headers (except HIOR mess)
[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 "net/tap.h"
27
28 #include "config-host.h"
29
30 #include <sys/ioctl.h>
31 #include <sys/stat.h>
32 #include <sys/wait.h>
33 #include <sys/socket.h>
34 #include <net/if.h>
35
36 #include "net.h"
37 #include "sysemu.h"
38 #include "qemu-char.h"
39 #include "qemu-common.h"
40 #include "qemu-error.h"
41
42 #include "net/tap-linux.h"
43
44 #include "hw/vhost_net.h"
45
46 /* Maximum GSO packet size (64k) plus plenty of room for
47 * the ethernet and virtio_net headers
48 */
49 #define TAP_BUFSIZE (4096 + 65536)
50
51 typedef struct TAPState {
52 VLANClientState nc;
53 int fd;
54 char down_script[1024];
55 char down_script_arg[128];
56 uint8_t buf[TAP_BUFSIZE];
57 unsigned int read_poll : 1;
58 unsigned int write_poll : 1;
59 unsigned int using_vnet_hdr : 1;
60 unsigned int has_ufo: 1;
61 VHostNetState *vhost_net;
62 unsigned host_vnet_hdr_len;
63 } TAPState;
64
65 static int launch_script(const char *setup_script, const char *ifname, int fd);
66
67 static int tap_can_send(void *opaque);
68 static void tap_send(void *opaque);
69 static void tap_writable(void *opaque);
70
71 static void tap_update_fd_handler(TAPState *s)
72 {
73 qemu_set_fd_handler2(s->fd,
74 s->read_poll ? tap_can_send : NULL,
75 s->read_poll ? tap_send : NULL,
76 s->write_poll ? tap_writable : NULL,
77 s);
78 }
79
80 static void tap_read_poll(TAPState *s, int enable)
81 {
82 s->read_poll = !!enable;
83 tap_update_fd_handler(s);
84 }
85
86 static void tap_write_poll(TAPState *s, int enable)
87 {
88 s->write_poll = !!enable;
89 tap_update_fd_handler(s);
90 }
91
92 static void tap_writable(void *opaque)
93 {
94 TAPState *s = opaque;
95
96 tap_write_poll(s, 0);
97
98 qemu_flush_queued_packets(&s->nc);
99 }
100
101 static ssize_t tap_write_packet(TAPState *s, const struct iovec *iov, int iovcnt)
102 {
103 ssize_t len;
104
105 do {
106 len = writev(s->fd, iov, iovcnt);
107 } while (len == -1 && errno == EINTR);
108
109 if (len == -1 && errno == EAGAIN) {
110 tap_write_poll(s, 1);
111 return 0;
112 }
113
114 return len;
115 }
116
117 static ssize_t tap_receive_iov(VLANClientState *nc, const struct iovec *iov,
118 int iovcnt)
119 {
120 TAPState *s = DO_UPCAST(TAPState, nc, nc);
121 const struct iovec *iovp = iov;
122 struct iovec iov_copy[iovcnt + 1];
123 struct virtio_net_hdr_mrg_rxbuf hdr = { };
124
125 if (s->host_vnet_hdr_len && !s->using_vnet_hdr) {
126 iov_copy[0].iov_base = &hdr;
127 iov_copy[0].iov_len = s->host_vnet_hdr_len;
128 memcpy(&iov_copy[1], iov, iovcnt * sizeof(*iov));
129 iovp = iov_copy;
130 iovcnt++;
131 }
132
133 return tap_write_packet(s, iovp, iovcnt);
134 }
135
136 static ssize_t tap_receive_raw(VLANClientState *nc, const uint8_t *buf, size_t size)
137 {
138 TAPState *s = DO_UPCAST(TAPState, nc, nc);
139 struct iovec iov[2];
140 int iovcnt = 0;
141 struct virtio_net_hdr_mrg_rxbuf hdr = { };
142
143 if (s->host_vnet_hdr_len) {
144 iov[iovcnt].iov_base = &hdr;
145 iov[iovcnt].iov_len = s->host_vnet_hdr_len;
146 iovcnt++;
147 }
148
149 iov[iovcnt].iov_base = (char *)buf;
150 iov[iovcnt].iov_len = size;
151 iovcnt++;
152
153 return tap_write_packet(s, iov, iovcnt);
154 }
155
156 static ssize_t tap_receive(VLANClientState *nc, const uint8_t *buf, size_t size)
157 {
158 TAPState *s = DO_UPCAST(TAPState, nc, nc);
159 struct iovec iov[1];
160
161 if (s->host_vnet_hdr_len && !s->using_vnet_hdr) {
162 return tap_receive_raw(nc, buf, size);
163 }
164
165 iov[0].iov_base = (char *)buf;
166 iov[0].iov_len = size;
167
168 return tap_write_packet(s, iov, 1);
169 }
170
171 static int tap_can_send(void *opaque)
172 {
173 TAPState *s = opaque;
174
175 return qemu_can_send_packet(&s->nc);
176 }
177
178 #ifndef __sun__
179 ssize_t tap_read_packet(int tapfd, uint8_t *buf, int maxlen)
180 {
181 return read(tapfd, buf, maxlen);
182 }
183 #endif
184
185 static void tap_send_completed(VLANClientState *nc, ssize_t len)
186 {
187 TAPState *s = DO_UPCAST(TAPState, nc, nc);
188 tap_read_poll(s, 1);
189 }
190
191 static void tap_send(void *opaque)
192 {
193 TAPState *s = opaque;
194 int size;
195
196 do {
197 uint8_t *buf = s->buf;
198
199 size = tap_read_packet(s->fd, s->buf, sizeof(s->buf));
200 if (size <= 0) {
201 break;
202 }
203
204 if (s->host_vnet_hdr_len && !s->using_vnet_hdr) {
205 buf += s->host_vnet_hdr_len;
206 size -= s->host_vnet_hdr_len;
207 }
208
209 size = qemu_send_packet_async(&s->nc, buf, size, tap_send_completed);
210 if (size == 0) {
211 tap_read_poll(s, 0);
212 }
213 } while (size > 0 && qemu_can_send_packet(&s->nc));
214 }
215
216 int tap_has_ufo(VLANClientState *nc)
217 {
218 TAPState *s = DO_UPCAST(TAPState, nc, nc);
219
220 assert(nc->info->type == NET_CLIENT_TYPE_TAP);
221
222 return s->has_ufo;
223 }
224
225 int tap_has_vnet_hdr(VLANClientState *nc)
226 {
227 TAPState *s = DO_UPCAST(TAPState, nc, nc);
228
229 assert(nc->info->type == NET_CLIENT_TYPE_TAP);
230
231 return !!s->host_vnet_hdr_len;
232 }
233
234 int tap_has_vnet_hdr_len(VLANClientState *nc, int len)
235 {
236 TAPState *s = DO_UPCAST(TAPState, nc, nc);
237
238 assert(nc->info->type == NET_CLIENT_TYPE_TAP);
239
240 return tap_probe_vnet_hdr_len(s->fd, len);
241 }
242
243 void tap_set_vnet_hdr_len(VLANClientState *nc, int len)
244 {
245 TAPState *s = DO_UPCAST(TAPState, nc, nc);
246
247 assert(nc->info->type == NET_CLIENT_TYPE_TAP);
248 assert(len == sizeof(struct virtio_net_hdr_mrg_rxbuf) ||
249 len == sizeof(struct virtio_net_hdr));
250
251 tap_fd_set_vnet_hdr_len(s->fd, len);
252 s->host_vnet_hdr_len = len;
253 }
254
255 void tap_using_vnet_hdr(VLANClientState *nc, int using_vnet_hdr)
256 {
257 TAPState *s = DO_UPCAST(TAPState, nc, nc);
258
259 using_vnet_hdr = using_vnet_hdr != 0;
260
261 assert(nc->info->type == NET_CLIENT_TYPE_TAP);
262 assert(!!s->host_vnet_hdr_len == using_vnet_hdr);
263
264 s->using_vnet_hdr = using_vnet_hdr;
265 }
266
267 void tap_set_offload(VLANClientState *nc, int csum, int tso4,
268 int tso6, int ecn, int ufo)
269 {
270 TAPState *s = DO_UPCAST(TAPState, nc, nc);
271 if (s->fd < 0) {
272 return;
273 }
274
275 tap_fd_set_offload(s->fd, csum, tso4, tso6, ecn, ufo);
276 }
277
278 static void tap_cleanup(VLANClientState *nc)
279 {
280 TAPState *s = DO_UPCAST(TAPState, nc, nc);
281
282 if (s->vhost_net) {
283 vhost_net_cleanup(s->vhost_net);
284 s->vhost_net = NULL;
285 }
286
287 qemu_purge_queued_packets(nc);
288
289 if (s->down_script[0])
290 launch_script(s->down_script, s->down_script_arg, s->fd);
291
292 tap_read_poll(s, 0);
293 tap_write_poll(s, 0);
294 close(s->fd);
295 s->fd = -1;
296 }
297
298 static void tap_poll(VLANClientState *nc, bool enable)
299 {
300 TAPState *s = DO_UPCAST(TAPState, nc, nc);
301 tap_read_poll(s, enable);
302 tap_write_poll(s, enable);
303 }
304
305 int tap_get_fd(VLANClientState *nc)
306 {
307 TAPState *s = DO_UPCAST(TAPState, nc, nc);
308 assert(nc->info->type == NET_CLIENT_TYPE_TAP);
309 return s->fd;
310 }
311
312 /* fd support */
313
314 static NetClientInfo net_tap_info = {
315 .type = NET_CLIENT_TYPE_TAP,
316 .size = sizeof(TAPState),
317 .receive = tap_receive,
318 .receive_raw = tap_receive_raw,
319 .receive_iov = tap_receive_iov,
320 .poll = tap_poll,
321 .cleanup = tap_cleanup,
322 };
323
324 static TAPState *net_tap_fd_init(VLANState *vlan,
325 const char *model,
326 const char *name,
327 int fd,
328 int vnet_hdr)
329 {
330 VLANClientState *nc;
331 TAPState *s;
332
333 nc = qemu_new_net_client(&net_tap_info, vlan, NULL, model, name);
334
335 s = DO_UPCAST(TAPState, nc, nc);
336
337 s->fd = fd;
338 s->host_vnet_hdr_len = vnet_hdr ? sizeof(struct virtio_net_hdr) : 0;
339 s->using_vnet_hdr = 0;
340 s->has_ufo = tap_probe_has_ufo(s->fd);
341 tap_set_offload(&s->nc, 0, 0, 0, 0, 0);
342 tap_read_poll(s, 1);
343 s->vhost_net = NULL;
344 return s;
345 }
346
347 static int launch_script(const char *setup_script, const char *ifname, int fd)
348 {
349 int pid, status;
350 char *args[3];
351 char **parg;
352
353 /* try to launch network script */
354 pid = fork();
355 if (pid == 0) {
356 int open_max = sysconf(_SC_OPEN_MAX), i;
357
358 for (i = 0; i < open_max; i++) {
359 if (i != STDIN_FILENO &&
360 i != STDOUT_FILENO &&
361 i != STDERR_FILENO &&
362 i != fd) {
363 close(i);
364 }
365 }
366 parg = args;
367 *parg++ = (char *)setup_script;
368 *parg++ = (char *)ifname;
369 *parg = NULL;
370 execv(setup_script, args);
371 _exit(1);
372 } else if (pid > 0) {
373 while (waitpid(pid, &status, 0) != pid) {
374 /* loop */
375 }
376
377 if (WIFEXITED(status) && WEXITSTATUS(status) == 0) {
378 return 0;
379 }
380 }
381 fprintf(stderr, "%s: could not launch network script\n", setup_script);
382 return -1;
383 }
384
385 static int net_tap_init(QemuOpts *opts, int *vnet_hdr)
386 {
387 int fd, vnet_hdr_required;
388 char ifname[128] = {0,};
389 const char *setup_script;
390
391 if (qemu_opt_get(opts, "ifname")) {
392 pstrcpy(ifname, sizeof(ifname), qemu_opt_get(opts, "ifname"));
393 }
394
395 *vnet_hdr = qemu_opt_get_bool(opts, "vnet_hdr", 1);
396 if (qemu_opt_get(opts, "vnet_hdr")) {
397 vnet_hdr_required = *vnet_hdr;
398 } else {
399 vnet_hdr_required = 0;
400 }
401
402 TFR(fd = tap_open(ifname, sizeof(ifname), vnet_hdr, vnet_hdr_required));
403 if (fd < 0) {
404 return -1;
405 }
406
407 setup_script = qemu_opt_get(opts, "script");
408 if (setup_script &&
409 setup_script[0] != '\0' &&
410 strcmp(setup_script, "no") != 0 &&
411 launch_script(setup_script, ifname, fd)) {
412 close(fd);
413 return -1;
414 }
415
416 qemu_opt_set(opts, "ifname", ifname);
417
418 return fd;
419 }
420
421 int net_init_tap(QemuOpts *opts, Monitor *mon, const char *name, VLANState *vlan)
422 {
423 TAPState *s;
424 int fd, vnet_hdr = 0;
425
426 if (qemu_opt_get(opts, "fd")) {
427 if (qemu_opt_get(opts, "ifname") ||
428 qemu_opt_get(opts, "script") ||
429 qemu_opt_get(opts, "downscript") ||
430 qemu_opt_get(opts, "vnet_hdr")) {
431 error_report("ifname=, script=, downscript= and vnet_hdr= is invalid with fd=");
432 return -1;
433 }
434
435 fd = net_handle_fd_param(mon, qemu_opt_get(opts, "fd"));
436 if (fd == -1) {
437 return -1;
438 }
439
440 fcntl(fd, F_SETFL, O_NONBLOCK);
441
442 vnet_hdr = tap_probe_vnet_hdr(fd);
443 } else {
444 if (!qemu_opt_get(opts, "script")) {
445 qemu_opt_set(opts, "script", DEFAULT_NETWORK_SCRIPT);
446 }
447
448 if (!qemu_opt_get(opts, "downscript")) {
449 qemu_opt_set(opts, "downscript", DEFAULT_NETWORK_DOWN_SCRIPT);
450 }
451
452 fd = net_tap_init(opts, &vnet_hdr);
453 if (fd == -1) {
454 return -1;
455 }
456 }
457
458 s = net_tap_fd_init(vlan, "tap", name, fd, vnet_hdr);
459 if (!s) {
460 close(fd);
461 return -1;
462 }
463
464 if (tap_set_sndbuf(s->fd, opts) < 0) {
465 return -1;
466 }
467
468 if (qemu_opt_get(opts, "fd")) {
469 snprintf(s->nc.info_str, sizeof(s->nc.info_str), "fd=%d", fd);
470 } else {
471 const char *ifname, *script, *downscript;
472
473 ifname = qemu_opt_get(opts, "ifname");
474 script = qemu_opt_get(opts, "script");
475 downscript = qemu_opt_get(opts, "downscript");
476
477 snprintf(s->nc.info_str, sizeof(s->nc.info_str),
478 "ifname=%s,script=%s,downscript=%s",
479 ifname, script, downscript);
480
481 if (strcmp(downscript, "no") != 0) {
482 snprintf(s->down_script, sizeof(s->down_script), "%s", downscript);
483 snprintf(s->down_script_arg, sizeof(s->down_script_arg), "%s", ifname);
484 }
485 }
486
487 if (qemu_opt_get_bool(opts, "vhost", !!qemu_opt_get(opts, "vhostfd") ||
488 qemu_opt_get_bool(opts, "vhostforce", false))) {
489 int vhostfd, r;
490 bool force = qemu_opt_get_bool(opts, "vhostforce", false);
491 if (qemu_opt_get(opts, "vhostfd")) {
492 r = net_handle_fd_param(mon, qemu_opt_get(opts, "vhostfd"));
493 if (r == -1) {
494 return -1;
495 }
496 vhostfd = r;
497 } else {
498 vhostfd = -1;
499 }
500 s->vhost_net = vhost_net_init(&s->nc, vhostfd, force);
501 if (!s->vhost_net) {
502 error_report("vhost-net requested but could not be initialized");
503 return -1;
504 }
505 } else if (qemu_opt_get(opts, "vhostfd")) {
506 error_report("vhostfd= is not valid without vhost");
507 return -1;
508 }
509
510 return 0;
511 }
512
513 VHostNetState *tap_get_vhost_net(VLANClientState *nc)
514 {
515 TAPState *s = DO_UPCAST(TAPState, nc, nc);
516 assert(nc->info->type == NET_CLIENT_TYPE_TAP);
517 return s->vhost_net;
518 }