1 /*
2 * QEMU System Emulator
3 *
4 * Copyright (c) 2003-2008 Fabrice Bellard
5 * Copyright (c) 2022 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
28 #include "net/net.h"
29 #include "clients.h"
30 #include "monitor/monitor.h"
31 #include "qapi/error.h"
32 #include "qemu/error-report.h"
33 #include "qemu/option.h"
34 #include "qemu/sockets.h"
35 #include "qemu/iov.h"
36 #include "qemu/main-loop.h"
37 #include "qemu/cutils.h"
38
39 typedef struct NetDgramState {
40 NetClientState nc;
41 int fd;
42 SocketReadState rs;
43 bool read_poll; /* waiting to receive data? */
44 bool write_poll; /* waiting to transmit data? */
45 /* contains destination iff connectionless */
46 struct sockaddr *dest_addr;
47 socklen_t dest_len;
48 } NetDgramState;
49
50 static void net_dgram_send(void *opaque);
51 static void net_dgram_writable(void *opaque);
52
net_dgram_update_fd_handler(NetDgramState * s)53 static void net_dgram_update_fd_handler(NetDgramState *s)
54 {
55 qemu_set_fd_handler(s->fd,
56 s->read_poll ? net_dgram_send : NULL,
57 s->write_poll ? net_dgram_writable : NULL,
58 s);
59 }
60
net_dgram_read_poll(NetDgramState * s,bool enable)61 static void net_dgram_read_poll(NetDgramState *s, bool enable)
62 {
63 s->read_poll = enable;
64 net_dgram_update_fd_handler(s);
65 }
66
net_dgram_write_poll(NetDgramState * s,bool enable)67 static void net_dgram_write_poll(NetDgramState *s, bool enable)
68 {
69 s->write_poll = enable;
70 net_dgram_update_fd_handler(s);
71 }
72
net_dgram_writable(void * opaque)73 static void net_dgram_writable(void *opaque)
74 {
75 NetDgramState *s = opaque;
76
77 net_dgram_write_poll(s, false);
78
79 qemu_flush_queued_packets(&s->nc);
80 }
81
net_dgram_receive(NetClientState * nc,const uint8_t * buf,size_t size)82 static ssize_t net_dgram_receive(NetClientState *nc,
83 const uint8_t *buf, size_t size)
84 {
85 NetDgramState *s = DO_UPCAST(NetDgramState, nc, nc);
86 ssize_t ret;
87
88 do {
89 if (s->dest_addr) {
90 ret = sendto(s->fd, buf, size, 0, s->dest_addr, s->dest_len);
91 } else {
92 ret = send(s->fd, buf, size, 0);
93 }
94 } while (ret == -1 && errno == EINTR);
95
96 if (ret == -1 && errno == EAGAIN) {
97 net_dgram_write_poll(s, true);
98 return 0;
99 }
100 return ret;
101 }
102
net_dgram_send_completed(NetClientState * nc,ssize_t len)103 static void net_dgram_send_completed(NetClientState *nc, ssize_t len)
104 {
105 NetDgramState *s = DO_UPCAST(NetDgramState, nc, nc);
106
107 if (!s->read_poll) {
108 net_dgram_read_poll(s, true);
109 }
110 }
111
net_dgram_rs_finalize(SocketReadState * rs)112 static void net_dgram_rs_finalize(SocketReadState *rs)
113 {
114 NetDgramState *s = container_of(rs, NetDgramState, rs);
115
116 if (qemu_send_packet_async(&s->nc, rs->buf,
117 rs->packet_len,
118 net_dgram_send_completed) == 0) {
119 net_dgram_read_poll(s, false);
120 }
121 }
122
net_dgram_send(void * opaque)123 static void net_dgram_send(void *opaque)
124 {
125 NetDgramState *s = opaque;
126 int size;
127
128 size = recv(s->fd, s->rs.buf, sizeof(s->rs.buf), 0);
129 if (size < 0) {
130 return;
131 }
132 if (size == 0) {
133 /* end of connection */
134 net_dgram_read_poll(s, false);
135 net_dgram_write_poll(s, false);
136 return;
137 }
138 if (qemu_send_packet_async(&s->nc, s->rs.buf, size,
139 net_dgram_send_completed) == 0) {
140 net_dgram_read_poll(s, false);
141 }
142 }
143
net_dgram_mcast_create(struct sockaddr_in * mcastaddr,struct in_addr * localaddr,Error ** errp)144 static int net_dgram_mcast_create(struct sockaddr_in *mcastaddr,
145 struct in_addr *localaddr,
146 Error **errp)
147 {
148 struct ip_mreq imr;
149 int fd;
150 int val, ret;
151 #ifdef __OpenBSD__
152 unsigned char loop;
153 #else
154 int loop;
155 #endif
156
157 if (!IN_MULTICAST(ntohl(mcastaddr->sin_addr.s_addr))) {
158 error_setg(errp, "specified mcastaddr %s (0x%08x) "
159 "does not contain a multicast address",
160 inet_ntoa(mcastaddr->sin_addr),
161 (int)ntohl(mcastaddr->sin_addr.s_addr));
162 return -1;
163 }
164
165 fd = qemu_socket(PF_INET, SOCK_DGRAM, 0);
166 if (fd < 0) {
167 error_setg_errno(errp, errno, "can't create datagram socket");
168 return -1;
169 }
170
171 /*
172 * Allow multiple sockets to bind the same multicast ip and port by setting
173 * SO_REUSEADDR. This is the only situation where SO_REUSEADDR should be set
174 * on windows. Use socket_set_fast_reuse otherwise as it sets SO_REUSEADDR
175 * only on posix systems.
176 */
177 val = 1;
178 ret = setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &val, sizeof(val));
179 if (ret < 0) {
180 error_setg_errno(errp, errno, "can't set socket option SO_REUSEADDR");
181 goto fail;
182 }
183
184 ret = bind(fd, (struct sockaddr *)mcastaddr, sizeof(*mcastaddr));
185 if (ret < 0) {
186 error_setg_errno(errp, errno, "can't bind ip=%s to socket",
187 inet_ntoa(mcastaddr->sin_addr));
188 goto fail;
189 }
190
191 /* Add host to multicast group */
192 imr.imr_multiaddr = mcastaddr->sin_addr;
193 if (localaddr) {
194 imr.imr_interface = *localaddr;
195 } else {
196 imr.imr_interface.s_addr = htonl(INADDR_ANY);
197 }
198
199 ret = setsockopt(fd, IPPROTO_IP, IP_ADD_MEMBERSHIP,
200 &imr, sizeof(struct ip_mreq));
201 if (ret < 0) {
202 error_setg_errno(errp, errno,
203 "can't add socket to multicast group %s",
204 inet_ntoa(imr.imr_multiaddr));
205 goto fail;
206 }
207
208 /* Force mcast msgs to loopback (eg. several QEMUs in same host */
209 loop = 1;
210 ret = setsockopt(fd, IPPROTO_IP, IP_MULTICAST_LOOP,
211 &loop, sizeof(loop));
212 if (ret < 0) {
213 error_setg_errno(errp, errno,
214 "can't force multicast message to loopback");
215 goto fail;
216 }
217
218 /* If a bind address is given, only send packets from that address */
219 if (localaddr != NULL) {
220 ret = setsockopt(fd, IPPROTO_IP, IP_MULTICAST_IF,
221 localaddr, sizeof(*localaddr));
222 if (ret < 0) {
223 error_setg_errno(errp, errno,
224 "can't set the default network send interface");
225 goto fail;
226 }
227 }
228
229 qemu_socket_set_nonblock(fd);
230 return fd;
231 fail:
232 if (fd >= 0) {
233 close(fd);
234 }
235 return -1;
236 }
237
net_dgram_cleanup(NetClientState * nc)238 static void net_dgram_cleanup(NetClientState *nc)
239 {
240 NetDgramState *s = DO_UPCAST(NetDgramState, nc, nc);
241 if (s->fd != -1) {
242 net_dgram_read_poll(s, false);
243 net_dgram_write_poll(s, false);
244 close(s->fd);
245 s->fd = -1;
246 }
247 g_free(s->dest_addr);
248 s->dest_addr = NULL;
249 s->dest_len = 0;
250 }
251
252 static NetClientInfo net_dgram_socket_info = {
253 .type = NET_CLIENT_DRIVER_DGRAM,
254 .size = sizeof(NetDgramState),
255 .receive = net_dgram_receive,
256 .cleanup = net_dgram_cleanup,
257 };
258
net_dgram_fd_init(NetClientState * peer,const char * model,const char * name,int fd,Error ** errp)259 static NetDgramState *net_dgram_fd_init(NetClientState *peer,
260 const char *model,
261 const char *name,
262 int fd,
263 Error **errp)
264 {
265 NetClientState *nc;
266 NetDgramState *s;
267
268 nc = qemu_new_net_client(&net_dgram_socket_info, peer, model, name);
269
270 s = DO_UPCAST(NetDgramState, nc, nc);
271
272 s->fd = fd;
273 net_socket_rs_init(&s->rs, net_dgram_rs_finalize, false);
274 net_dgram_read_poll(s, true);
275
276 return s;
277 }
278
net_dgram_mcast_init(NetClientState * peer,const char * model,const char * name,SocketAddress * remote,SocketAddress * local,Error ** errp)279 static int net_dgram_mcast_init(NetClientState *peer,
280 const char *model,
281 const char *name,
282 SocketAddress *remote,
283 SocketAddress *local,
284 Error **errp)
285 {
286 NetDgramState *s;
287 int fd, ret;
288 struct sockaddr_in *saddr;
289
290 if (remote->type != SOCKET_ADDRESS_TYPE_INET) {
291 error_setg(errp, "multicast only support inet type");
292 return -1;
293 }
294
295 saddr = g_new(struct sockaddr_in, 1);
296 if (convert_host_port(saddr, remote->u.inet.host, remote->u.inet.port,
297 errp) < 0) {
298 g_free(saddr);
299 return -1;
300 }
301
302 if (!local) {
303 fd = net_dgram_mcast_create(saddr, NULL, errp);
304 if (fd < 0) {
305 g_free(saddr);
306 return -1;
307 }
308 } else {
309 switch (local->type) {
310 case SOCKET_ADDRESS_TYPE_INET: {
311 struct in_addr localaddr;
312
313 if (inet_aton(local->u.inet.host, &localaddr) == 0) {
314 g_free(saddr);
315 error_setg(errp, "localaddr '%s' is not a valid IPv4 address",
316 local->u.inet.host);
317 return -1;
318 }
319
320 fd = net_dgram_mcast_create(saddr, &localaddr, errp);
321 if (fd < 0) {
322 g_free(saddr);
323 return -1;
324 }
325 break;
326 }
327 case SOCKET_ADDRESS_TYPE_FD: {
328 int newfd;
329
330 fd = monitor_fd_param(monitor_cur(), local->u.fd.str, errp);
331 if (fd == -1) {
332 g_free(saddr);
333 return -1;
334 }
335 ret = qemu_socket_try_set_nonblock(fd);
336 if (ret < 0) {
337 g_free(saddr);
338 error_setg_errno(errp, -ret, "%s: Can't use file descriptor %d",
339 name, fd);
340 return -1;
341 }
342
343 /*
344 * fd passed: multicast: "learn" dest_addr address from bound
345 * address and save it. Because this may be "shared" socket from a
346 * "master" process, datagrams would be recv() by ONLY ONE process:
347 * we must "clone" this dgram socket --jjo
348 */
349
350 saddr = g_new(struct sockaddr_in, 1);
351
352 if (convert_host_port(saddr, local->u.inet.host, local->u.inet.port,
353 errp) < 0) {
354 g_free(saddr);
355 close(fd);
356 return -1;
357 }
358
359 /* must be bound */
360 if (saddr->sin_addr.s_addr == 0) {
361 error_setg(errp, "can't setup multicast destination address");
362 g_free(saddr);
363 close(fd);
364 return -1;
365 }
366 /* clone dgram socket */
367 newfd = net_dgram_mcast_create(saddr, NULL, errp);
368 if (newfd < 0) {
369 g_free(saddr);
370 close(fd);
371 return -1;
372 }
373 /* clone newfd to fd, close newfd */
374 dup2(newfd, fd);
375 close(newfd);
376 break;
377 }
378 default:
379 g_free(saddr);
380 error_setg(errp, "only support inet or fd type for local");
381 return -1;
382 }
383 }
384
385 s = net_dgram_fd_init(peer, model, name, fd, errp);
386 if (!s) {
387 g_free(saddr);
388 return -1;
389 }
390
391 g_assert(s->dest_addr == NULL);
392 s->dest_addr = (struct sockaddr *)saddr;
393 s->dest_len = sizeof(*saddr);
394
395 if (!local) {
396 qemu_set_info_str(&s->nc, "mcast=%s:%d",
397 inet_ntoa(saddr->sin_addr),
398 ntohs(saddr->sin_port));
399 } else {
400 switch (local->type) {
401 case SOCKET_ADDRESS_TYPE_INET:
402 qemu_set_info_str(&s->nc, "mcast=%s:%d",
403 inet_ntoa(saddr->sin_addr),
404 ntohs(saddr->sin_port));
405 break;
406 case SOCKET_ADDRESS_TYPE_FD:
407 qemu_set_info_str(&s->nc, "fd=%d (cloned mcast=%s:%d)",
408 fd, inet_ntoa(saddr->sin_addr),
409 ntohs(saddr->sin_port));
410 break;
411 default:
412 g_assert_not_reached();
413 }
414 }
415
416 return 0;
417
418 }
419
420
net_init_dgram(const Netdev * netdev,const char * name,NetClientState * peer,Error ** errp)421 int net_init_dgram(const Netdev *netdev, const char *name,
422 NetClientState *peer, Error **errp)
423 {
424 NetDgramState *s;
425 int fd, ret;
426 SocketAddress *remote, *local;
427 struct sockaddr *dest_addr;
428 struct sockaddr_in laddr_in, raddr_in;
429 struct sockaddr_un laddr_un, raddr_un;
430 socklen_t dest_len;
431
432 assert(netdev->type == NET_CLIENT_DRIVER_DGRAM);
433
434 remote = netdev->u.dgram.remote;
435 local = netdev->u.dgram.local;
436
437 /* detect multicast address */
438 if (remote && remote->type == SOCKET_ADDRESS_TYPE_INET) {
439 struct sockaddr_in mcastaddr;
440
441 if (convert_host_port(&mcastaddr, remote->u.inet.host,
442 remote->u.inet.port, errp) < 0) {
443 return -1;
444 }
445
446 if (IN_MULTICAST(ntohl(mcastaddr.sin_addr.s_addr))) {
447 return net_dgram_mcast_init(peer, "dram", name, remote, local,
448 errp);
449 }
450 }
451
452 /* unicast address */
453 if (!local) {
454 error_setg(errp, "dgram requires local= parameter");
455 return -1;
456 }
457
458 if (remote) {
459 if (local->type == SOCKET_ADDRESS_TYPE_FD) {
460 error_setg(errp, "don't set remote with local.fd");
461 return -1;
462 }
463 if (remote->type != local->type) {
464 error_setg(errp, "remote and local types must be the same");
465 return -1;
466 }
467 } else {
468 if (local->type != SOCKET_ADDRESS_TYPE_FD) {
469 error_setg(errp,
470 "type=inet or type=unix requires remote parameter");
471 return -1;
472 }
473 }
474
475 switch (local->type) {
476 case SOCKET_ADDRESS_TYPE_INET:
477 if (convert_host_port(&laddr_in, local->u.inet.host, local->u.inet.port,
478 errp) < 0) {
479 return -1;
480 }
481
482 if (convert_host_port(&raddr_in, remote->u.inet.host,
483 remote->u.inet.port, errp) < 0) {
484 return -1;
485 }
486
487 fd = qemu_socket(PF_INET, SOCK_DGRAM, 0);
488 if (fd < 0) {
489 error_setg_errno(errp, errno, "can't create datagram socket");
490 return -1;
491 }
492
493 ret = socket_set_fast_reuse(fd);
494 if (ret < 0) {
495 error_setg_errno(errp, errno,
496 "can't set socket option SO_REUSEADDR");
497 close(fd);
498 return -1;
499 }
500 ret = bind(fd, (struct sockaddr *)&laddr_in, sizeof(laddr_in));
501 if (ret < 0) {
502 error_setg_errno(errp, errno, "can't bind ip=%s to socket",
503 inet_ntoa(laddr_in.sin_addr));
504 close(fd);
505 return -1;
506 }
507 qemu_socket_set_nonblock(fd);
508
509 dest_len = sizeof(raddr_in);
510 dest_addr = g_malloc(dest_len);
511 memcpy(dest_addr, &raddr_in, dest_len);
512 break;
513 case SOCKET_ADDRESS_TYPE_UNIX:
514 ret = unlink(local->u.q_unix.path);
515 if (ret < 0 && errno != ENOENT) {
516 error_setg_errno(errp, errno, "failed to unlink socket %s",
517 local->u.q_unix.path);
518 return -1;
519 }
520
521 laddr_un.sun_family = PF_UNIX;
522 ret = snprintf(laddr_un.sun_path, sizeof(laddr_un.sun_path), "%s",
523 local->u.q_unix.path);
524 if (ret < 0 || ret >= sizeof(laddr_un.sun_path)) {
525 error_setg(errp, "UNIX socket path '%s' is too long",
526 local->u.q_unix.path);
527 error_append_hint(errp, "Path must be less than %zu bytes\n",
528 sizeof(laddr_un.sun_path));
529 }
530
531 raddr_un.sun_family = PF_UNIX;
532 ret = snprintf(raddr_un.sun_path, sizeof(raddr_un.sun_path), "%s",
533 remote->u.q_unix.path);
534 if (ret < 0 || ret >= sizeof(raddr_un.sun_path)) {
535 error_setg(errp, "UNIX socket path '%s' is too long",
536 remote->u.q_unix.path);
537 error_append_hint(errp, "Path must be less than %zu bytes\n",
538 sizeof(raddr_un.sun_path));
539 }
540
541 fd = qemu_socket(PF_UNIX, SOCK_DGRAM, 0);
542 if (fd < 0) {
543 error_setg_errno(errp, errno, "can't create datagram socket");
544 return -1;
545 }
546
547 ret = bind(fd, (struct sockaddr *)&laddr_un, sizeof(laddr_un));
548 if (ret < 0) {
549 error_setg_errno(errp, errno, "can't bind unix=%s to socket",
550 laddr_un.sun_path);
551 close(fd);
552 return -1;
553 }
554 qemu_socket_set_nonblock(fd);
555
556 dest_len = sizeof(raddr_un);
557 dest_addr = g_malloc(dest_len);
558 memcpy(dest_addr, &raddr_un, dest_len);
559 break;
560 case SOCKET_ADDRESS_TYPE_FD:
561 fd = monitor_fd_param(monitor_cur(), local->u.fd.str, errp);
562 if (fd == -1) {
563 return -1;
564 }
565 ret = qemu_socket_try_set_nonblock(fd);
566 if (ret < 0) {
567 error_setg_errno(errp, -ret, "%s: Can't use file descriptor %d",
568 name, fd);
569 return -1;
570 }
571 dest_addr = NULL;
572 dest_len = 0;
573 break;
574 default:
575 error_setg(errp, "only support inet or fd type for local");
576 return -1;
577 }
578
579 s = net_dgram_fd_init(peer, "dgram", name, fd, errp);
580 if (!s) {
581 return -1;
582 }
583
584 if (remote) {
585 g_assert(s->dest_addr == NULL);
586 s->dest_addr = dest_addr;
587 s->dest_len = dest_len;
588 }
589
590 switch (local->type) {
591 case SOCKET_ADDRESS_TYPE_INET:
592 qemu_set_info_str(&s->nc, "udp=%s:%d/%s:%d",
593 inet_ntoa(laddr_in.sin_addr),
594 ntohs(laddr_in.sin_port),
595 inet_ntoa(raddr_in.sin_addr),
596 ntohs(raddr_in.sin_port));
597 break;
598 case SOCKET_ADDRESS_TYPE_UNIX:
599 qemu_set_info_str(&s->nc, "udp=%s:%s",
600 laddr_un.sun_path, raddr_un.sun_path);
601 break;
602 case SOCKET_ADDRESS_TYPE_FD: {
603 SocketAddress *sa;
604 SocketAddressType sa_type;
605
606 sa = socket_local_address(fd, errp);
607 if (sa) {
608 sa_type = sa->type;
609 qapi_free_SocketAddress(sa);
610
611 qemu_set_info_str(&s->nc, "fd=%d %s", fd,
612 SocketAddressType_str(sa_type));
613 } else {
614 qemu_set_info_str(&s->nc, "fd=%d", fd);
615 }
616 break;
617 }
618 default:
619 g_assert_not_reached();
620 }
621
622 return 0;
623 }
624