Bug Summary

File:net/tap.c
Location:line 469, column 14
Description:Value stored to 'parg' is never read

Annotated Source Code

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 "monitor.h"
38#include "sysemu.h"
39#include "qemu-char.h"
40#include "qemu-common.h"
41#include "qemu-error.h"
42
43#include "net/tap-linux.h"
44
45#include "hw/vhost_net.h"
46
47/* Maximum GSO packet size (64k) plus plenty of room for
48 * the ethernet and virtio_net headers
49 */
50#define TAP_BUFSIZE(4096 + 65536) (4096 + 65536)
51
52typedef struct TAPState {
53 VLANClientState nc;
54 int fd;
55 char down_script[1024];
56 char down_script_arg[128];
57 uint8_t buf[TAP_BUFSIZE(4096 + 65536)];
58 unsigned int read_poll : 1;
59 unsigned int write_poll : 1;
60 unsigned int using_vnet_hdr : 1;
61 unsigned int has_ufo: 1;
62 VHostNetState *vhost_net;
63 unsigned host_vnet_hdr_len;
64} TAPState;
65
66static int launch_script(const char *setup_script, const char *ifname, int fd);
67
68static int tap_can_send(void *opaque);
69static void tap_send(void *opaque);
70static void tap_writable(void *opaque);
71
72static void tap_update_fd_handler(TAPState *s)
73{
74 qemu_set_fd_handler2(s->fd,
75 s->read_poll ? tap_can_send : NULL((void*)0),
76 s->read_poll ? tap_send : NULL((void*)0),
77 s->write_poll ? tap_writable : NULL((void*)0),
78 s);
79}
80
81static void tap_read_poll(TAPState *s, int enable)
82{
83 s->read_poll = !!enable;
84 tap_update_fd_handler(s);
85}
86
87static void tap_write_poll(TAPState *s, int enable)
88{
89 s->write_poll = !!enable;
90 tap_update_fd_handler(s);
91}
92
93static void tap_writable(void *opaque)
94{
95 TAPState *s = opaque;
96
97 tap_write_poll(s, 0);
98
99 qemu_flush_queued_packets(&s->nc);
100}
101
102static ssize_t tap_write_packet(TAPState *s, const struct iovec *iov, int iovcnt)
103{
104 ssize_t len;
105
106 do {
107 len = writev(s->fd, iov, iovcnt);
108 } while (len == -1 && errno(*__errno_location ()) == EINTR4);
109
110 if (len == -1 && errno(*__errno_location ()) == EAGAIN11) {
111 tap_write_poll(s, 1);
112 return 0;
113 }
114
115 return len;
116}
117
118static ssize_t tap_receive_iov(VLANClientState *nc, const struct iovec *iov,
119 int iovcnt)
120{
121 TAPState *s = DO_UPCAST(TAPState, nc, nc)( __extension__ ( { char __attribute__((unused)) offset_must_be_zero
[ -__builtin_offsetof(TAPState, nc)]; ({ const typeof(((TAPState
*) 0)->nc) *__mptr = (nc); (TAPState *) ((char *) __mptr -
__builtin_offsetof(TAPState, nc));});}));
122 const struct iovec *iovp = iov;
123 struct iovec iov_copy[iovcnt + 1];
124 struct virtio_net_hdr_mrg_rxbuf hdr = { };
125
126 if (s->host_vnet_hdr_len && !s->using_vnet_hdr) {
127 iov_copy[0].iov_base = &hdr;
128 iov_copy[0].iov_len = s->host_vnet_hdr_len;
129 memcpy(&iov_copy[1], iov, iovcnt * sizeof(*iov));
130 iovp = iov_copy;
131 iovcnt++;
132 }
133
134 return tap_write_packet(s, iovp, iovcnt);
135}
136
137static ssize_t tap_receive_raw(VLANClientState *nc, const uint8_t *buf, size_t size)
138{
139 TAPState *s = DO_UPCAST(TAPState, nc, nc)( __extension__ ( { char __attribute__((unused)) offset_must_be_zero
[ -__builtin_offsetof(TAPState, nc)]; ({ const typeof(((TAPState
*) 0)->nc) *__mptr = (nc); (TAPState *) ((char *) __mptr -
__builtin_offsetof(TAPState, nc));});}));
140 struct iovec iov[2];
141 int iovcnt = 0;
142 struct virtio_net_hdr_mrg_rxbuf hdr = { };
143
144 if (s->host_vnet_hdr_len) {
145 iov[iovcnt].iov_base = &hdr;
146 iov[iovcnt].iov_len = s->host_vnet_hdr_len;
147 iovcnt++;
148 }
149
150 iov[iovcnt].iov_base = (char *)buf;
151 iov[iovcnt].iov_len = size;
152 iovcnt++;
153
154 return tap_write_packet(s, iov, iovcnt);
155}
156
157static ssize_t tap_receive(VLANClientState *nc, const uint8_t *buf, size_t size)
158{
159 TAPState *s = DO_UPCAST(TAPState, nc, nc)( __extension__ ( { char __attribute__((unused)) offset_must_be_zero
[ -__builtin_offsetof(TAPState, nc)]; ({ const typeof(((TAPState
*) 0)->nc) *__mptr = (nc); (TAPState *) ((char *) __mptr -
__builtin_offsetof(TAPState, nc));});}));
160 struct iovec iov[1];
161
162 if (s->host_vnet_hdr_len && !s->using_vnet_hdr) {
163 return tap_receive_raw(nc, buf, size);
164 }
165
166 iov[0].iov_base = (char *)buf;
167 iov[0].iov_len = size;
168
169 return tap_write_packet(s, iov, 1);
170}
171
172static int tap_can_send(void *opaque)
173{
174 TAPState *s = opaque;
175
176 return qemu_can_send_packet(&s->nc);
177}
178
179#ifndef __sun__
180ssize_t tap_read_packet(int tapfd, uint8_t *buf, int maxlen)
181{
182 return read(tapfd, buf, maxlen);
183}
184#endif
185
186static void tap_send_completed(VLANClientState *nc, ssize_t len)
187{
188 TAPState *s = DO_UPCAST(TAPState, nc, nc)( __extension__ ( { char __attribute__((unused)) offset_must_be_zero
[ -__builtin_offsetof(TAPState, nc)]; ({ const typeof(((TAPState
*) 0)->nc) *__mptr = (nc); (TAPState *) ((char *) __mptr -
__builtin_offsetof(TAPState, nc));});}));
189 tap_read_poll(s, 1);
190}
191
192static void tap_send(void *opaque)
193{
194 TAPState *s = opaque;
195 int size;
196
197 do {
198 uint8_t *buf = s->buf;
199
200 size = tap_read_packet(s->fd, s->buf, sizeof(s->buf));
201 if (size <= 0) {
202 break;
203 }
204
205 if (s->host_vnet_hdr_len && !s->using_vnet_hdr) {
206 buf += s->host_vnet_hdr_len;
207 size -= s->host_vnet_hdr_len;
208 }
209
210 size = qemu_send_packet_async(&s->nc, buf, size, tap_send_completed);
211 if (size == 0) {
212 tap_read_poll(s, 0);
213 }
214 } while (size > 0 && qemu_can_send_packet(&s->nc));
215}
216
217int tap_has_ufo(VLANClientState *nc)
218{
219 TAPState *s = DO_UPCAST(TAPState, nc, nc)( __extension__ ( { char __attribute__((unused)) offset_must_be_zero
[ -__builtin_offsetof(TAPState, nc)]; ({ const typeof(((TAPState
*) 0)->nc) *__mptr = (nc); (TAPState *) ((char *) __mptr -
__builtin_offsetof(TAPState, nc));});}));
220
221 assert(nc->info->type == NET_CLIENT_TYPE_TAP)((nc->info->type == NET_CLIENT_TYPE_TAP) ? (void) (0) :
__assert_fail ("nc->info->type == NET_CLIENT_TYPE_TAP"
, "/home/stefan/src/qemu/qemu.org/qemu/net/tap.c", 221, __PRETTY_FUNCTION__
));
222
223 return s->has_ufo;
224}
225
226int tap_has_vnet_hdr(VLANClientState *nc)
227{
228 TAPState *s = DO_UPCAST(TAPState, nc, nc)( __extension__ ( { char __attribute__((unused)) offset_must_be_zero
[ -__builtin_offsetof(TAPState, nc)]; ({ const typeof(((TAPState
*) 0)->nc) *__mptr = (nc); (TAPState *) ((char *) __mptr -
__builtin_offsetof(TAPState, nc));});}));
229
230 assert(nc->info->type == NET_CLIENT_TYPE_TAP)((nc->info->type == NET_CLIENT_TYPE_TAP) ? (void) (0) :
__assert_fail ("nc->info->type == NET_CLIENT_TYPE_TAP"
, "/home/stefan/src/qemu/qemu.org/qemu/net/tap.c", 230, __PRETTY_FUNCTION__
));
231
232 return !!s->host_vnet_hdr_len;
233}
234
235int tap_has_vnet_hdr_len(VLANClientState *nc, int len)
236{
237 TAPState *s = DO_UPCAST(TAPState, nc, nc)( __extension__ ( { char __attribute__((unused)) offset_must_be_zero
[ -__builtin_offsetof(TAPState, nc)]; ({ const typeof(((TAPState
*) 0)->nc) *__mptr = (nc); (TAPState *) ((char *) __mptr -
__builtin_offsetof(TAPState, nc));});}));
238
239 assert(nc->info->type == NET_CLIENT_TYPE_TAP)((nc->info->type == NET_CLIENT_TYPE_TAP) ? (void) (0) :
__assert_fail ("nc->info->type == NET_CLIENT_TYPE_TAP"
, "/home/stefan/src/qemu/qemu.org/qemu/net/tap.c", 239, __PRETTY_FUNCTION__
));
240
241 return tap_probe_vnet_hdr_len(s->fd, len);
242}
243
244void tap_set_vnet_hdr_len(VLANClientState *nc, int len)
245{
246 TAPState *s = DO_UPCAST(TAPState, nc, nc)( __extension__ ( { char __attribute__((unused)) offset_must_be_zero
[ -__builtin_offsetof(TAPState, nc)]; ({ const typeof(((TAPState
*) 0)->nc) *__mptr = (nc); (TAPState *) ((char *) __mptr -
__builtin_offsetof(TAPState, nc));});}));
247
248 assert(nc->info->type == NET_CLIENT_TYPE_TAP)((nc->info->type == NET_CLIENT_TYPE_TAP) ? (void) (0) :
__assert_fail ("nc->info->type == NET_CLIENT_TYPE_TAP"
, "/home/stefan/src/qemu/qemu.org/qemu/net/tap.c", 248, __PRETTY_FUNCTION__
));
249 assert(len == sizeof(struct virtio_net_hdr_mrg_rxbuf) ||((len == sizeof(struct virtio_net_hdr_mrg_rxbuf) || len == sizeof
(struct virtio_net_hdr)) ? (void) (0) : __assert_fail ("len == sizeof(struct virtio_net_hdr_mrg_rxbuf) || len == sizeof(struct virtio_net_hdr)"
, "/home/stefan/src/qemu/qemu.org/qemu/net/tap.c", 250, __PRETTY_FUNCTION__
))
250 len == sizeof(struct virtio_net_hdr))((len == sizeof(struct virtio_net_hdr_mrg_rxbuf) || len == sizeof
(struct virtio_net_hdr)) ? (void) (0) : __assert_fail ("len == sizeof(struct virtio_net_hdr_mrg_rxbuf) || len == sizeof(struct virtio_net_hdr)"
, "/home/stefan/src/qemu/qemu.org/qemu/net/tap.c", 250, __PRETTY_FUNCTION__
));
251
252 tap_fd_set_vnet_hdr_len(s->fd, len);
253 s->host_vnet_hdr_len = len;
254}
255
256void tap_using_vnet_hdr(VLANClientState *nc, int using_vnet_hdr)
257{
258 TAPState *s = DO_UPCAST(TAPState, nc, nc)( __extension__ ( { char __attribute__((unused)) offset_must_be_zero
[ -__builtin_offsetof(TAPState, nc)]; ({ const typeof(((TAPState
*) 0)->nc) *__mptr = (nc); (TAPState *) ((char *) __mptr -
__builtin_offsetof(TAPState, nc));});}));
259
260 using_vnet_hdr = using_vnet_hdr != 0;
261
262 assert(nc->info->type == NET_CLIENT_TYPE_TAP)((nc->info->type == NET_CLIENT_TYPE_TAP) ? (void) (0) :
__assert_fail ("nc->info->type == NET_CLIENT_TYPE_TAP"
, "/home/stefan/src/qemu/qemu.org/qemu/net/tap.c", 262, __PRETTY_FUNCTION__
));
263 assert(!!s->host_vnet_hdr_len == using_vnet_hdr)((!!s->host_vnet_hdr_len == using_vnet_hdr) ? (void) (0) :
__assert_fail ("!!s->host_vnet_hdr_len == using_vnet_hdr"
, "/home/stefan/src/qemu/qemu.org/qemu/net/tap.c", 263, __PRETTY_FUNCTION__
));
264
265 s->using_vnet_hdr = using_vnet_hdr;
266}
267
268void tap_set_offload(VLANClientState *nc, int csum, int tso4,
269 int tso6, int ecn, int ufo)
270{
271 TAPState *s = DO_UPCAST(TAPState, nc, nc)( __extension__ ( { char __attribute__((unused)) offset_must_be_zero
[ -__builtin_offsetof(TAPState, nc)]; ({ const typeof(((TAPState
*) 0)->nc) *__mptr = (nc); (TAPState *) ((char *) __mptr -
__builtin_offsetof(TAPState, nc));});}));
272 if (s->fd < 0) {
273 return;
274 }
275
276 tap_fd_set_offload(s->fd, csum, tso4, tso6, ecn, ufo);
277}
278
279static void tap_cleanup(VLANClientState *nc)
280{
281 TAPState *s = DO_UPCAST(TAPState, nc, nc)( __extension__ ( { char __attribute__((unused)) offset_must_be_zero
[ -__builtin_offsetof(TAPState, nc)]; ({ const typeof(((TAPState
*) 0)->nc) *__mptr = (nc); (TAPState *) ((char *) __mptr -
__builtin_offsetof(TAPState, nc));});}));
282
283 if (s->vhost_net) {
284 vhost_net_cleanup(s->vhost_net);
285 s->vhost_net = NULL((void*)0);
286 }
287
288 qemu_purge_queued_packets(nc);
289
290 if (s->down_script[0])
291 launch_script(s->down_script, s->down_script_arg, s->fd);
292
293 tap_read_poll(s, 0);
294 tap_write_poll(s, 0);
295 close(s->fd);
296 s->fd = -1;
297}
298
299static void tap_poll(VLANClientState *nc, bool_Bool enable)
300{
301 TAPState *s = DO_UPCAST(TAPState, nc, nc)( __extension__ ( { char __attribute__((unused)) offset_must_be_zero
[ -__builtin_offsetof(TAPState, nc)]; ({ const typeof(((TAPState
*) 0)->nc) *__mptr = (nc); (TAPState *) ((char *) __mptr -
__builtin_offsetof(TAPState, nc));});}));
302 tap_read_poll(s, enable);
303 tap_write_poll(s, enable);
304}
305
306int tap_get_fd(VLANClientState *nc)
307{
308 TAPState *s = DO_UPCAST(TAPState, nc, nc)( __extension__ ( { char __attribute__((unused)) offset_must_be_zero
[ -__builtin_offsetof(TAPState, nc)]; ({ const typeof(((TAPState
*) 0)->nc) *__mptr = (nc); (TAPState *) ((char *) __mptr -
__builtin_offsetof(TAPState, nc));});}));
309 assert(nc->info->type == NET_CLIENT_TYPE_TAP)((nc->info->type == NET_CLIENT_TYPE_TAP) ? (void) (0) :
__assert_fail ("nc->info->type == NET_CLIENT_TYPE_TAP"
, "/home/stefan/src/qemu/qemu.org/qemu/net/tap.c", 309, __PRETTY_FUNCTION__
));
310 return s->fd;
311}
312
313/* fd support */
314
315static NetClientInfo net_tap_info = {
316 .type = NET_CLIENT_TYPE_TAP,
317 .size = sizeof(TAPState),
318 .receive = tap_receive,
319 .receive_raw = tap_receive_raw,
320 .receive_iov = tap_receive_iov,
321 .poll = tap_poll,
322 .cleanup = tap_cleanup,
323};
324
325static TAPState *net_tap_fd_init(VLANState *vlan,
326 const char *model,
327 const char *name,
328 int fd,
329 int vnet_hdr)
330{
331 VLANClientState *nc;
332 TAPState *s;
333
334 nc = qemu_new_net_client(&net_tap_info, vlan, NULL((void*)0), model, name);
335
336 s = DO_UPCAST(TAPState, nc, nc)( __extension__ ( { char __attribute__((unused)) offset_must_be_zero
[ -__builtin_offsetof(TAPState, nc)]; ({ const typeof(((TAPState
*) 0)->nc) *__mptr = (nc); (TAPState *) ((char *) __mptr -
__builtin_offsetof(TAPState, nc));});}));
337
338 s->fd = fd;
339 s->host_vnet_hdr_len = vnet_hdr ? sizeof(struct virtio_net_hdr) : 0;
340 s->using_vnet_hdr = 0;
341 s->has_ufo = tap_probe_has_ufo(s->fd);
342 tap_set_offload(&s->nc, 0, 0, 0, 0, 0);
343 tap_read_poll(s, 1);
344 s->vhost_net = NULL((void*)0);
345 return s;
346}
347
348static int launch_script(const char *setup_script, const char *ifname, int fd)
349{
350 int pid, status;
351 char *args[3];
352 char **parg;
353
354 /* try to launch network script */
355 pid = fork();
356 if (pid == 0) {
357 int open_max = sysconf(_SC_OPEN_MAX_SC_OPEN_MAX), i;
358
359 for (i = 0; i < open_max; i++) {
360 if (i != STDIN_FILENO0 &&
361 i != STDOUT_FILENO1 &&
362 i != STDERR_FILENO2 &&
363 i != fd) {
364 close(i);
365 }
366 }
367 parg = args;
368 *parg++ = (char *)setup_script;
369 *parg++ = (char *)ifname;
370 *parg = NULL((void*)0);
371 execv(setup_script, args);
372 _exit(1);
373 } else if (pid > 0) {
374 while (waitpid(pid, &status, 0) != pid) {
375 /* loop */
376 }
377
378 if (WIFEXITED(status)((((__extension__ (((union { __typeof(status) __in; int __i; }
) { .__in = (status) }).__i))) & 0x7f) == 0) && WEXITSTATUS(status)((((__extension__ (((union { __typeof(status) __in; int __i; }
) { .__in = (status) }).__i))) & 0xff00) >> 8) == 0) {
379 return 0;
380 }
381 }
382 fprintf(stderrstderr, "%s: could not launch network script\n", setup_script);
383 return -1;
384}
385
386static int recv_fd(int c)
387{
388 int fd;
389 uint8_t msgbuf[CMSG_SPACE(sizeof(fd))((((sizeof(fd)) + sizeof (size_t) - 1) & (size_t) ~(sizeof
(size_t) - 1)) + (((sizeof (struct cmsghdr)) + sizeof (size_t
) - 1) & (size_t) ~(sizeof (size_t) - 1)))];
390 struct msghdr msg = {
391 .msg_control = msgbuf,
392 .msg_controllen = sizeof(msgbuf),
393 };
394 struct cmsghdr *cmsg;
395 struct iovec iov;
396 uint8_t req[1];
397 ssize_t len;
398
399 cmsg = CMSG_FIRSTHDR(&msg)((size_t) (&msg)->msg_controllen >= sizeof (struct cmsghdr
) ? (struct cmsghdr *) (&msg)->msg_control : (struct cmsghdr
*) 0);
400 cmsg->cmsg_level = SOL_SOCKET1;
401 cmsg->cmsg_type = SCM_RIGHTSSCM_RIGHTS;
402 cmsg->cmsg_len = CMSG_LEN(sizeof(fd))((((sizeof (struct cmsghdr)) + sizeof (size_t) - 1) & (size_t
) ~(sizeof (size_t) - 1)) + (sizeof(fd)));
403 msg.msg_controllen = cmsg->cmsg_len;
404
405 iov.iov_base = req;
406 iov.iov_len = sizeof(req);
407
408 msg.msg_iov = &iov;
409 msg.msg_iovlen = 1;
410
411 len = recvmsg(c, &msg, 0);
412 if (len > 0) {
413 memcpy(&fd, CMSG_DATA(cmsg)((cmsg)->__cmsg_data), sizeof(fd));
414 return fd;
415 }
416
417 return len;
418}
419
420static int net_bridge_run_helper(const char *helper, const char *bridge)
421{
422 sigset_t oldmask, mask;
423 int pid, status;
424 char *args[5];
425 char **parg;
426 int sv[2];
427
428 sigemptyset(&mask);
429 sigaddset(&mask, SIGCHLD17);
430 sigprocmask(SIG_BLOCK0, &mask, &oldmask);
431
432 if (socketpair(PF_UNIX1, SOCK_STREAMSOCK_STREAM, 0, sv) == -1) {
433 return -1;
434 }
435
436 /* try to launch bridge helper */
437 pid = fork();
438 if (pid == 0) {
439 int open_max = sysconf(_SC_OPEN_MAX_SC_OPEN_MAX), i;
440 char fd_buf[6+10];
441 char br_buf[6+IFNAMSIZ16] = {0};
442 char helper_cmd[PATH_MAX4096 + sizeof(fd_buf) + sizeof(br_buf) + 15];
443
444 for (i = 0; i < open_max; i++) {
445 if (i != STDIN_FILENO0 &&
446 i != STDOUT_FILENO1 &&
447 i != STDERR_FILENO2 &&
448 i != sv[1]) {
449 close(i);
450 }
451 }
452
453 snprintf(fd_buf, sizeof(fd_buf), "%s%d", "--fd=", sv[1]);
454
455 if (strrchr(helper, ' ') || strrchr(helper, '\t')) {
456 /* assume helper is a command */
457
458 if (strstr(helper, "--br=") == NULL((void*)0)) {
459 snprintf(br_buf, sizeof(br_buf), "%s%s", "--br=", bridge);
460 }
461
462 snprintf(helper_cmd, sizeof(helper_cmd), "%s %s %s %s",
463 helper, "--use-vnet", fd_buf, br_buf);
464
465 parg = args;
466 *parg++ = (char *)"sh";
467 *parg++ = (char *)"-c";
468 *parg++ = helper_cmd;
469 *parg++ = NULL((void*)0);
Value stored to 'parg' is never read
470
471 execv("/bin/sh", args);
472 } else {
473 /* assume helper is just the executable path name */
474
475 snprintf(br_buf, sizeof(br_buf), "%s%s", "--br=", bridge);
476
477 parg = args;
478 *parg++ = (char *)helper;
479 *parg++ = (char *)"--use-vnet";
480 *parg++ = fd_buf;
481 *parg++ = br_buf;
482 *parg++ = NULL((void*)0);
483
484 execv(helper, args);
485 }
486 _exit(1);
487
488 } else if (pid > 0) {
489 int fd;
490
491 close(sv[1]);
492
493 do {
494 fd = recv_fd(sv[0]);
495 } while (fd == -1 && errno(*__errno_location ()) == EINTR4);
496
497 close(sv[0]);
498
499 while (waitpid(pid, &status, 0) != pid) {
500 /* loop */
501 }
502 sigprocmask(SIG_SETMASK2, &oldmask, NULL((void*)0));
503 if (fd < 0) {
504 fprintf(stderrstderr, "failed to recv file descriptor\n");
505 return -1;
506 }
507
508 if (WIFEXITED(status)((((__extension__ (((union { __typeof(status) __in; int __i; }
) { .__in = (status) }).__i))) & 0x7f) == 0) && WEXITSTATUS(status)((((__extension__ (((union { __typeof(status) __in; int __i; }
) { .__in = (status) }).__i))) & 0xff00) >> 8) == 0) {
509 return fd;
510 }
511 }
512 fprintf(stderrstderr, "failed to launch bridge helper\n");
513 return -1;
514}
515
516int net_init_bridge(QemuOpts *opts, const char *name, VLANState *vlan)
517{
518 TAPState *s;
519 int fd, vnet_hdr;
520
521 if (!qemu_opt_get(opts, "br")) {
522 qemu_opt_set(opts, "br", DEFAULT_BRIDGE_INTERFACE"br0");
523 }
524 if (!qemu_opt_get(opts, "helper")) {
525 qemu_opt_set(opts, "helper", DEFAULT_BRIDGE_HELPER"/usr/local/libexec" "/qemu-bridge-helper");
526 }
527
528 fd = net_bridge_run_helper(qemu_opt_get(opts, "helper"),
529 qemu_opt_get(opts, "br"));
530 if (fd == -1) {
531 return -1;
532 }
533
534 fcntl(fd, F_SETFL4, O_NONBLOCK04000);
535
536 vnet_hdr = tap_probe_vnet_hdr(fd);
537
538 s = net_tap_fd_init(vlan, "bridge", name, fd, vnet_hdr);
539 if (!s) {
540 close(fd);
541 return -1;
542 }
543
544 snprintf(s->nc.info_str, sizeof(s->nc.info_str), "helper=%s,br=%s",
545 qemu_opt_get(opts, "helper"), qemu_opt_get(opts, "br"));
546
547 return 0;
548}
549
550static int net_tap_init(QemuOpts *opts, int *vnet_hdr)
551{
552 int fd, vnet_hdr_required;
553 char ifname[128] = {0,};
554 const char *setup_script;
555
556 if (qemu_opt_get(opts, "ifname")) {
557 pstrcpy(ifname, sizeof(ifname), qemu_opt_get(opts, "ifname"));
558 }
559
560 *vnet_hdr = qemu_opt_get_bool(opts, "vnet_hdr", 1);
561 if (qemu_opt_get(opts, "vnet_hdr")) {
562 vnet_hdr_required = *vnet_hdr;
563 } else {
564 vnet_hdr_required = 0;
565 }
566
567 TFR(fd = tap_open(ifname, sizeof(ifname), vnet_hdr, vnet_hdr_required))do { if ((fd = tap_open(ifname, sizeof(ifname), vnet_hdr, vnet_hdr_required
)) != -1) break; } while ((*__errno_location ()) == 4);
568 if (fd < 0) {
569 return -1;
570 }
571
572 setup_script = qemu_opt_get(opts, "script");
573 if (setup_script &&
574 setup_script[0] != '\0' &&
575 strcmp(setup_script, "no") != 0 &&
576 launch_script(setup_script, ifname, fd)) {
577 close(fd);
578 return -1;
579 }
580
581 qemu_opt_set(opts, "ifname", ifname);
582
583 return fd;
584}
585
586int net_init_tap(QemuOpts *opts, const char *name, VLANState *vlan)
587{
588 TAPState *s;
589 int fd, vnet_hdr = 0;
590 const char *model;
591
592 if (qemu_opt_get(opts, "fd")) {
593 if (qemu_opt_get(opts, "ifname") ||
594 qemu_opt_get(opts, "script") ||
595 qemu_opt_get(opts, "downscript") ||
596 qemu_opt_get(opts, "vnet_hdr") ||
597 qemu_opt_get(opts, "helper")) {
598 error_report("ifname=, script=, downscript=, vnet_hdr=, "
599 "and helper= are invalid with fd=");
600 return -1;
601 }
602
603 fd = net_handle_fd_param(cur_mon, qemu_opt_get(opts, "fd"));
604 if (fd == -1) {
605 return -1;
606 }
607
608 fcntl(fd, F_SETFL4, O_NONBLOCK04000);
609
610 vnet_hdr = tap_probe_vnet_hdr(fd);
611
612 model = "tap";
613
614 } else if (qemu_opt_get(opts, "helper")) {
615 if (qemu_opt_get(opts, "ifname") ||
616 qemu_opt_get(opts, "script") ||
617 qemu_opt_get(opts, "downscript") ||
618 qemu_opt_get(opts, "vnet_hdr")) {
619 error_report("ifname=, script=, downscript=, and vnet_hdr= "
620 "are invalid with helper=");
621 return -1;
622 }
623
624 fd = net_bridge_run_helper(qemu_opt_get(opts, "helper"),
625 DEFAULT_BRIDGE_INTERFACE"br0");
626 if (fd == -1) {
627 return -1;
628 }
629
630 fcntl(fd, F_SETFL4, O_NONBLOCK04000);
631
632 vnet_hdr = tap_probe_vnet_hdr(fd);
633
634 model = "bridge";
635
636 } else {
637 if (!qemu_opt_get(opts, "script")) {
638 qemu_opt_set(opts, "script", DEFAULT_NETWORK_SCRIPT"/etc/qemu-ifup");
639 }
640
641 if (!qemu_opt_get(opts, "downscript")) {
642 qemu_opt_set(opts, "downscript", DEFAULT_NETWORK_DOWN_SCRIPT"/etc/qemu-ifdown");
643 }
644
645 fd = net_tap_init(opts, &vnet_hdr);
646 if (fd == -1) {
647 return -1;
648 }
649
650 model = "tap";
651 }
652
653 s = net_tap_fd_init(vlan, model, name, fd, vnet_hdr);
654 if (!s) {
655 close(fd);
656 return -1;
657 }
658
659 if (tap_set_sndbuf(s->fd, opts) < 0) {
660 return -1;
661 }
662
663 if (qemu_opt_get(opts, "fd")) {
664 snprintf(s->nc.info_str, sizeof(s->nc.info_str), "fd=%d", fd);
665 } else if (qemu_opt_get(opts, "helper")) {
666 snprintf(s->nc.info_str, sizeof(s->nc.info_str),
667 "helper=%s", qemu_opt_get(opts, "helper"));
668 } else {
669 const char *ifname, *script, *downscript;
670
671 ifname = qemu_opt_get(opts, "ifname");
672 script = qemu_opt_get(opts, "script");
673 downscript = qemu_opt_get(opts, "downscript");
674
675 snprintf(s->nc.info_str, sizeof(s->nc.info_str),
676 "ifname=%s,script=%s,downscript=%s",
677 ifname, script, downscript);
678
679 if (strcmp(downscript, "no") != 0) {
680 snprintf(s->down_script, sizeof(s->down_script), "%s", downscript);
681 snprintf(s->down_script_arg, sizeof(s->down_script_arg), "%s", ifname);
682 }
683 }
684
685 if (qemu_opt_get_bool(opts, "vhost", !!qemu_opt_get(opts, "vhostfd") ||
686 qemu_opt_get_bool(opts, "vhostforce", false0))) {
687 int vhostfd, r;
688 bool_Bool force = qemu_opt_get_bool(opts, "vhostforce", false0);
689 if (qemu_opt_get(opts, "vhostfd")) {
690 r = net_handle_fd_param(cur_mon, qemu_opt_get(opts, "vhostfd"));
691 if (r == -1) {
692 return -1;
693 }
694 vhostfd = r;
695 } else {
696 vhostfd = -1;
697 }
698 s->vhost_net = vhost_net_init(&s->nc, vhostfd, force);
699 if (!s->vhost_net) {
700 error_report("vhost-net requested but could not be initialized");
701 return -1;
702 }
703 } else if (qemu_opt_get(opts, "vhostfd")) {
704 error_report("vhostfd= is not valid without vhost");
705 return -1;
706 }
707
708 return 0;
709}
710
711VHostNetState *tap_get_vhost_net(VLANClientState *nc)
712{
713 TAPState *s = DO_UPCAST(TAPState, nc, nc)( __extension__ ( { char __attribute__((unused)) offset_must_be_zero
[ -__builtin_offsetof(TAPState, nc)]; ({ const typeof(((TAPState
*) 0)->nc) *__mptr = (nc); (TAPState *) ((char *) __mptr -
__builtin_offsetof(TAPState, nc));});}));
714 assert(nc->info->type == NET_CLIENT_TYPE_TAP)((nc->info->type == NET_CLIENT_TYPE_TAP) ? (void) (0) :
__assert_fail ("nc->info->type == NET_CLIENT_TYPE_TAP"
, "/home/stefan/src/qemu/qemu.org/qemu/net/tap.c", 714, __PRETTY_FUNCTION__
));
715 return s->vhost_net;
716}