xref: /qemu/net/net.c (revision 33848cee)
1 /*
2  * QEMU System Emulator
3  *
4  * Copyright (c) 2003-2008 Fabrice Bellard
5  *
6  * Permission is hereby granted, free of charge, to any person obtaining a copy
7  * of this software and associated documentation files (the "Software"), to deal
8  * in the Software without restriction, including without limitation the rights
9  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
10  * copies of the Software, and to permit persons to whom the Software is
11  * furnished to do so, subject to the following conditions:
12  *
13  * The above copyright notice and this permission notice shall be included in
14  * all copies or substantial portions of the Software.
15  *
16  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
17  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
19  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
20  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
21  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
22  * THE SOFTWARE.
23  */
24 #include "qemu/osdep.h"
25 
26 #include "net/net.h"
27 #include "clients.h"
28 #include "hub.h"
29 #include "net/slirp.h"
30 #include "net/eth.h"
31 #include "util.h"
32 
33 #include "monitor/monitor.h"
34 #include "qemu-common.h"
35 #include "qemu/help_option.h"
36 #include "qapi/qmp/qerror.h"
37 #include "qemu/error-report.h"
38 #include "qemu/sockets.h"
39 #include "qemu/cutils.h"
40 #include "qemu/config-file.h"
41 #include "qmp-commands.h"
42 #include "hw/qdev.h"
43 #include "qemu/iov.h"
44 #include "qemu/main-loop.h"
45 #include "qapi-visit.h"
46 #include "qapi/opts-visitor.h"
47 #include "sysemu/sysemu.h"
48 #include "net/filter.h"
49 #include "qapi/string-output-visitor.h"
50 
51 /* Net bridge is currently not supported for W32. */
52 #if !defined(_WIN32)
53 # define CONFIG_NET_BRIDGE
54 #endif
55 
56 static VMChangeStateEntry *net_change_state_entry;
57 static QTAILQ_HEAD(, NetClientState) net_clients;
58 
59 const char *host_net_devices[] = {
60     "tap",
61     "socket",
62     "dump",
63 #ifdef CONFIG_NET_BRIDGE
64     "bridge",
65 #endif
66 #ifdef CONFIG_NETMAP
67     "netmap",
68 #endif
69 #ifdef CONFIG_SLIRP
70     "user",
71 #endif
72 #ifdef CONFIG_VDE
73     "vde",
74 #endif
75     "vhost-user",
76     NULL,
77 };
78 
79 /***********************************************************/
80 /* network device redirectors */
81 
82 static int get_str_sep(char *buf, int buf_size, const char **pp, int sep)
83 {
84     const char *p, *p1;
85     int len;
86     p = *pp;
87     p1 = strchr(p, sep);
88     if (!p1)
89         return -1;
90     len = p1 - p;
91     p1++;
92     if (buf_size > 0) {
93         if (len > buf_size - 1)
94             len = buf_size - 1;
95         memcpy(buf, p, len);
96         buf[len] = '\0';
97     }
98     *pp = p1;
99     return 0;
100 }
101 
102 int parse_host_port(struct sockaddr_in *saddr, const char *str)
103 {
104     char buf[512];
105     struct hostent *he;
106     const char *p, *r;
107     int port;
108 
109     p = str;
110     if (get_str_sep(buf, sizeof(buf), &p, ':') < 0)
111         return -1;
112     saddr->sin_family = AF_INET;
113     if (buf[0] == '\0') {
114         saddr->sin_addr.s_addr = 0;
115     } else {
116         if (qemu_isdigit(buf[0])) {
117             if (!inet_aton(buf, &saddr->sin_addr))
118                 return -1;
119         } else {
120             if ((he = gethostbyname(buf)) == NULL)
121                 return - 1;
122             saddr->sin_addr = *(struct in_addr *)he->h_addr;
123         }
124     }
125     port = strtol(p, (char **)&r, 0);
126     if (r == p)
127         return -1;
128     saddr->sin_port = htons(port);
129     return 0;
130 }
131 
132 char *qemu_mac_strdup_printf(const uint8_t *macaddr)
133 {
134     return g_strdup_printf("%.2x:%.2x:%.2x:%.2x:%.2x:%.2x",
135                            macaddr[0], macaddr[1], macaddr[2],
136                            macaddr[3], macaddr[4], macaddr[5]);
137 }
138 
139 void qemu_format_nic_info_str(NetClientState *nc, uint8_t macaddr[6])
140 {
141     snprintf(nc->info_str, sizeof(nc->info_str),
142              "model=%s,macaddr=%02x:%02x:%02x:%02x:%02x:%02x",
143              nc->model,
144              macaddr[0], macaddr[1], macaddr[2],
145              macaddr[3], macaddr[4], macaddr[5]);
146 }
147 
148 static int mac_table[256] = {0};
149 
150 static void qemu_macaddr_set_used(MACAddr *macaddr)
151 {
152     int index;
153 
154     for (index = 0x56; index < 0xFF; index++) {
155         if (macaddr->a[5] == index) {
156             mac_table[index]++;
157         }
158     }
159 }
160 
161 static void qemu_macaddr_set_free(MACAddr *macaddr)
162 {
163     int index;
164     static const MACAddr base = { .a = { 0x52, 0x54, 0x00, 0x12, 0x34, 0 } };
165 
166     if (memcmp(macaddr->a, &base.a, (sizeof(base.a) - 1)) != 0) {
167         return;
168     }
169     for (index = 0x56; index < 0xFF; index++) {
170         if (macaddr->a[5] == index) {
171             mac_table[index]--;
172         }
173     }
174 }
175 
176 static int qemu_macaddr_get_free(void)
177 {
178     int index;
179 
180     for (index = 0x56; index < 0xFF; index++) {
181         if (mac_table[index] == 0) {
182             return index;
183         }
184     }
185 
186     return -1;
187 }
188 
189 void qemu_macaddr_default_if_unset(MACAddr *macaddr)
190 {
191     static const MACAddr zero = { .a = { 0,0,0,0,0,0 } };
192     static const MACAddr base = { .a = { 0x52, 0x54, 0x00, 0x12, 0x34, 0 } };
193 
194     if (memcmp(macaddr, &zero, sizeof(zero)) != 0) {
195         if (memcmp(macaddr->a, &base.a, (sizeof(base.a) - 1)) != 0) {
196             return;
197         } else {
198             qemu_macaddr_set_used(macaddr);
199             return;
200         }
201     }
202 
203     macaddr->a[0] = 0x52;
204     macaddr->a[1] = 0x54;
205     macaddr->a[2] = 0x00;
206     macaddr->a[3] = 0x12;
207     macaddr->a[4] = 0x34;
208     macaddr->a[5] = qemu_macaddr_get_free();
209     qemu_macaddr_set_used(macaddr);
210 }
211 
212 /**
213  * Generate a name for net client
214  *
215  * Only net clients created with the legacy -net option and NICs need this.
216  */
217 static char *assign_name(NetClientState *nc1, const char *model)
218 {
219     NetClientState *nc;
220     int id = 0;
221 
222     QTAILQ_FOREACH(nc, &net_clients, next) {
223         if (nc == nc1) {
224             continue;
225         }
226         if (strcmp(nc->model, model) == 0) {
227             id++;
228         }
229     }
230 
231     return g_strdup_printf("%s.%d", model, id);
232 }
233 
234 static void qemu_net_client_destructor(NetClientState *nc)
235 {
236     g_free(nc);
237 }
238 
239 static void qemu_net_client_setup(NetClientState *nc,
240                                   NetClientInfo *info,
241                                   NetClientState *peer,
242                                   const char *model,
243                                   const char *name,
244                                   NetClientDestructor *destructor)
245 {
246     nc->info = info;
247     nc->model = g_strdup(model);
248     if (name) {
249         nc->name = g_strdup(name);
250     } else {
251         nc->name = assign_name(nc, model);
252     }
253 
254     if (peer) {
255         assert(!peer->peer);
256         nc->peer = peer;
257         peer->peer = nc;
258     }
259     QTAILQ_INSERT_TAIL(&net_clients, nc, next);
260 
261     nc->incoming_queue = qemu_new_net_queue(qemu_deliver_packet_iov, nc);
262     nc->destructor = destructor;
263     QTAILQ_INIT(&nc->filters);
264 }
265 
266 NetClientState *qemu_new_net_client(NetClientInfo *info,
267                                     NetClientState *peer,
268                                     const char *model,
269                                     const char *name)
270 {
271     NetClientState *nc;
272 
273     assert(info->size >= sizeof(NetClientState));
274 
275     nc = g_malloc0(info->size);
276     qemu_net_client_setup(nc, info, peer, model, name,
277                           qemu_net_client_destructor);
278 
279     return nc;
280 }
281 
282 NICState *qemu_new_nic(NetClientInfo *info,
283                        NICConf *conf,
284                        const char *model,
285                        const char *name,
286                        void *opaque)
287 {
288     NetClientState **peers = conf->peers.ncs;
289     NICState *nic;
290     int i, queues = MAX(1, conf->peers.queues);
291 
292     assert(info->type == NET_CLIENT_DRIVER_NIC);
293     assert(info->size >= sizeof(NICState));
294 
295     nic = g_malloc0(info->size + sizeof(NetClientState) * queues);
296     nic->ncs = (void *)nic + info->size;
297     nic->conf = conf;
298     nic->opaque = opaque;
299 
300     for (i = 0; i < queues; i++) {
301         qemu_net_client_setup(&nic->ncs[i], info, peers[i], model, name,
302                               NULL);
303         nic->ncs[i].queue_index = i;
304     }
305 
306     return nic;
307 }
308 
309 NetClientState *qemu_get_subqueue(NICState *nic, int queue_index)
310 {
311     return nic->ncs + queue_index;
312 }
313 
314 NetClientState *qemu_get_queue(NICState *nic)
315 {
316     return qemu_get_subqueue(nic, 0);
317 }
318 
319 NICState *qemu_get_nic(NetClientState *nc)
320 {
321     NetClientState *nc0 = nc - nc->queue_index;
322 
323     return (NICState *)((void *)nc0 - nc->info->size);
324 }
325 
326 void *qemu_get_nic_opaque(NetClientState *nc)
327 {
328     NICState *nic = qemu_get_nic(nc);
329 
330     return nic->opaque;
331 }
332 
333 static void qemu_cleanup_net_client(NetClientState *nc)
334 {
335     QTAILQ_REMOVE(&net_clients, nc, next);
336 
337     if (nc->info->cleanup) {
338         nc->info->cleanup(nc);
339     }
340 }
341 
342 static void qemu_free_net_client(NetClientState *nc)
343 {
344     if (nc->incoming_queue) {
345         qemu_del_net_queue(nc->incoming_queue);
346     }
347     if (nc->peer) {
348         nc->peer->peer = NULL;
349     }
350     g_free(nc->name);
351     g_free(nc->model);
352     if (nc->destructor) {
353         nc->destructor(nc);
354     }
355 }
356 
357 void qemu_del_net_client(NetClientState *nc)
358 {
359     NetClientState *ncs[MAX_QUEUE_NUM];
360     int queues, i;
361     NetFilterState *nf, *next;
362 
363     assert(nc->info->type != NET_CLIENT_DRIVER_NIC);
364 
365     /* If the NetClientState belongs to a multiqueue backend, we will change all
366      * other NetClientStates also.
367      */
368     queues = qemu_find_net_clients_except(nc->name, ncs,
369                                           NET_CLIENT_DRIVER_NIC,
370                                           MAX_QUEUE_NUM);
371     assert(queues != 0);
372 
373     QTAILQ_FOREACH_SAFE(nf, &nc->filters, next, next) {
374         object_unparent(OBJECT(nf));
375     }
376 
377     /* If there is a peer NIC, delete and cleanup client, but do not free. */
378     if (nc->peer && nc->peer->info->type == NET_CLIENT_DRIVER_NIC) {
379         NICState *nic = qemu_get_nic(nc->peer);
380         if (nic->peer_deleted) {
381             return;
382         }
383         nic->peer_deleted = true;
384 
385         for (i = 0; i < queues; i++) {
386             ncs[i]->peer->link_down = true;
387         }
388 
389         if (nc->peer->info->link_status_changed) {
390             nc->peer->info->link_status_changed(nc->peer);
391         }
392 
393         for (i = 0; i < queues; i++) {
394             qemu_cleanup_net_client(ncs[i]);
395         }
396 
397         return;
398     }
399 
400     for (i = 0; i < queues; i++) {
401         qemu_cleanup_net_client(ncs[i]);
402         qemu_free_net_client(ncs[i]);
403     }
404 }
405 
406 void qemu_del_nic(NICState *nic)
407 {
408     int i, queues = MAX(nic->conf->peers.queues, 1);
409 
410     qemu_macaddr_set_free(&nic->conf->macaddr);
411 
412     /* If this is a peer NIC and peer has already been deleted, free it now. */
413     if (nic->peer_deleted) {
414         for (i = 0; i < queues; i++) {
415             qemu_free_net_client(qemu_get_subqueue(nic, i)->peer);
416         }
417     }
418 
419     for (i = queues - 1; i >= 0; i--) {
420         NetClientState *nc = qemu_get_subqueue(nic, i);
421 
422         qemu_cleanup_net_client(nc);
423         qemu_free_net_client(nc);
424     }
425 
426     g_free(nic);
427 }
428 
429 void qemu_foreach_nic(qemu_nic_foreach func, void *opaque)
430 {
431     NetClientState *nc;
432 
433     QTAILQ_FOREACH(nc, &net_clients, next) {
434         if (nc->info->type == NET_CLIENT_DRIVER_NIC) {
435             if (nc->queue_index == 0) {
436                 func(qemu_get_nic(nc), opaque);
437             }
438         }
439     }
440 }
441 
442 bool qemu_has_ufo(NetClientState *nc)
443 {
444     if (!nc || !nc->info->has_ufo) {
445         return false;
446     }
447 
448     return nc->info->has_ufo(nc);
449 }
450 
451 bool qemu_has_vnet_hdr(NetClientState *nc)
452 {
453     if (!nc || !nc->info->has_vnet_hdr) {
454         return false;
455     }
456 
457     return nc->info->has_vnet_hdr(nc);
458 }
459 
460 bool qemu_has_vnet_hdr_len(NetClientState *nc, int len)
461 {
462     if (!nc || !nc->info->has_vnet_hdr_len) {
463         return false;
464     }
465 
466     return nc->info->has_vnet_hdr_len(nc, len);
467 }
468 
469 void qemu_using_vnet_hdr(NetClientState *nc, bool enable)
470 {
471     if (!nc || !nc->info->using_vnet_hdr) {
472         return;
473     }
474 
475     nc->info->using_vnet_hdr(nc, enable);
476 }
477 
478 void qemu_set_offload(NetClientState *nc, int csum, int tso4, int tso6,
479                           int ecn, int ufo)
480 {
481     if (!nc || !nc->info->set_offload) {
482         return;
483     }
484 
485     nc->info->set_offload(nc, csum, tso4, tso6, ecn, ufo);
486 }
487 
488 void qemu_set_vnet_hdr_len(NetClientState *nc, int len)
489 {
490     if (!nc || !nc->info->set_vnet_hdr_len) {
491         return;
492     }
493 
494     nc->info->set_vnet_hdr_len(nc, len);
495 }
496 
497 int qemu_set_vnet_le(NetClientState *nc, bool is_le)
498 {
499 #ifdef HOST_WORDS_BIGENDIAN
500     if (!nc || !nc->info->set_vnet_le) {
501         return -ENOSYS;
502     }
503 
504     return nc->info->set_vnet_le(nc, is_le);
505 #else
506     return 0;
507 #endif
508 }
509 
510 int qemu_set_vnet_be(NetClientState *nc, bool is_be)
511 {
512 #ifdef HOST_WORDS_BIGENDIAN
513     return 0;
514 #else
515     if (!nc || !nc->info->set_vnet_be) {
516         return -ENOSYS;
517     }
518 
519     return nc->info->set_vnet_be(nc, is_be);
520 #endif
521 }
522 
523 int qemu_can_send_packet(NetClientState *sender)
524 {
525     int vm_running = runstate_is_running();
526 
527     if (!vm_running) {
528         return 0;
529     }
530 
531     if (!sender->peer) {
532         return 1;
533     }
534 
535     if (sender->peer->receive_disabled) {
536         return 0;
537     } else if (sender->peer->info->can_receive &&
538                !sender->peer->info->can_receive(sender->peer)) {
539         return 0;
540     }
541     return 1;
542 }
543 
544 static ssize_t filter_receive_iov(NetClientState *nc,
545                                   NetFilterDirection direction,
546                                   NetClientState *sender,
547                                   unsigned flags,
548                                   const struct iovec *iov,
549                                   int iovcnt,
550                                   NetPacketSent *sent_cb)
551 {
552     ssize_t ret = 0;
553     NetFilterState *nf = NULL;
554 
555     if (direction == NET_FILTER_DIRECTION_TX) {
556         QTAILQ_FOREACH(nf, &nc->filters, next) {
557             ret = qemu_netfilter_receive(nf, direction, sender, flags, iov,
558                                          iovcnt, sent_cb);
559             if (ret) {
560                 return ret;
561             }
562         }
563     } else {
564         QTAILQ_FOREACH_REVERSE(nf, &nc->filters, NetFilterHead, next) {
565             ret = qemu_netfilter_receive(nf, direction, sender, flags, iov,
566                                          iovcnt, sent_cb);
567             if (ret) {
568                 return ret;
569             }
570         }
571     }
572 
573     return ret;
574 }
575 
576 static ssize_t filter_receive(NetClientState *nc,
577                               NetFilterDirection direction,
578                               NetClientState *sender,
579                               unsigned flags,
580                               const uint8_t *data,
581                               size_t size,
582                               NetPacketSent *sent_cb)
583 {
584     struct iovec iov = {
585         .iov_base = (void *)data,
586         .iov_len = size
587     };
588 
589     return filter_receive_iov(nc, direction, sender, flags, &iov, 1, sent_cb);
590 }
591 
592 void qemu_purge_queued_packets(NetClientState *nc)
593 {
594     if (!nc->peer) {
595         return;
596     }
597 
598     qemu_net_queue_purge(nc->peer->incoming_queue, nc);
599 }
600 
601 static
602 void qemu_flush_or_purge_queued_packets(NetClientState *nc, bool purge)
603 {
604     nc->receive_disabled = 0;
605 
606     if (nc->peer && nc->peer->info->type == NET_CLIENT_DRIVER_HUBPORT) {
607         if (net_hub_flush(nc->peer)) {
608             qemu_notify_event();
609         }
610     }
611     if (qemu_net_queue_flush(nc->incoming_queue)) {
612         /* We emptied the queue successfully, signal to the IO thread to repoll
613          * the file descriptor (for tap, for example).
614          */
615         qemu_notify_event();
616     } else if (purge) {
617         /* Unable to empty the queue, purge remaining packets */
618         qemu_net_queue_purge(nc->incoming_queue, nc);
619     }
620 }
621 
622 void qemu_flush_queued_packets(NetClientState *nc)
623 {
624     qemu_flush_or_purge_queued_packets(nc, false);
625 }
626 
627 static ssize_t qemu_send_packet_async_with_flags(NetClientState *sender,
628                                                  unsigned flags,
629                                                  const uint8_t *buf, int size,
630                                                  NetPacketSent *sent_cb)
631 {
632     NetQueue *queue;
633     int ret;
634 
635 #ifdef DEBUG_NET
636     printf("qemu_send_packet_async:\n");
637     qemu_hexdump((const char *)buf, stdout, "net", size);
638 #endif
639 
640     if (sender->link_down || !sender->peer) {
641         return size;
642     }
643 
644     /* Let filters handle the packet first */
645     ret = filter_receive(sender, NET_FILTER_DIRECTION_TX,
646                          sender, flags, buf, size, sent_cb);
647     if (ret) {
648         return ret;
649     }
650 
651     ret = filter_receive(sender->peer, NET_FILTER_DIRECTION_RX,
652                          sender, flags, buf, size, sent_cb);
653     if (ret) {
654         return ret;
655     }
656 
657     queue = sender->peer->incoming_queue;
658 
659     return qemu_net_queue_send(queue, sender, flags, buf, size, sent_cb);
660 }
661 
662 ssize_t qemu_send_packet_async(NetClientState *sender,
663                                const uint8_t *buf, int size,
664                                NetPacketSent *sent_cb)
665 {
666     return qemu_send_packet_async_with_flags(sender, QEMU_NET_PACKET_FLAG_NONE,
667                                              buf, size, sent_cb);
668 }
669 
670 void qemu_send_packet(NetClientState *nc, const uint8_t *buf, int size)
671 {
672     qemu_send_packet_async(nc, buf, size, NULL);
673 }
674 
675 ssize_t qemu_send_packet_raw(NetClientState *nc, const uint8_t *buf, int size)
676 {
677     return qemu_send_packet_async_with_flags(nc, QEMU_NET_PACKET_FLAG_RAW,
678                                              buf, size, NULL);
679 }
680 
681 static ssize_t nc_sendv_compat(NetClientState *nc, const struct iovec *iov,
682                                int iovcnt, unsigned flags)
683 {
684     uint8_t *buf = NULL;
685     uint8_t *buffer;
686     size_t offset;
687     ssize_t ret;
688 
689     if (iovcnt == 1) {
690         buffer = iov[0].iov_base;
691         offset = iov[0].iov_len;
692     } else {
693         offset = iov_size(iov, iovcnt);
694         if (offset > NET_BUFSIZE) {
695             return -1;
696         }
697         buf = g_malloc(offset);
698         buffer = buf;
699         offset = iov_to_buf(iov, iovcnt, 0, buf, offset);
700     }
701 
702     if (flags & QEMU_NET_PACKET_FLAG_RAW && nc->info->receive_raw) {
703         ret = nc->info->receive_raw(nc, buffer, offset);
704     } else {
705         ret = nc->info->receive(nc, buffer, offset);
706     }
707 
708     g_free(buf);
709     return ret;
710 }
711 
712 ssize_t qemu_deliver_packet_iov(NetClientState *sender,
713                                 unsigned flags,
714                                 const struct iovec *iov,
715                                 int iovcnt,
716                                 void *opaque)
717 {
718     NetClientState *nc = opaque;
719     int ret;
720 
721     if (nc->link_down) {
722         return iov_size(iov, iovcnt);
723     }
724 
725     if (nc->receive_disabled) {
726         return 0;
727     }
728 
729     if (nc->info->receive_iov && !(flags & QEMU_NET_PACKET_FLAG_RAW)) {
730         ret = nc->info->receive_iov(nc, iov, iovcnt);
731     } else {
732         ret = nc_sendv_compat(nc, iov, iovcnt, flags);
733     }
734 
735     if (ret == 0) {
736         nc->receive_disabled = 1;
737     }
738 
739     return ret;
740 }
741 
742 ssize_t qemu_sendv_packet_async(NetClientState *sender,
743                                 const struct iovec *iov, int iovcnt,
744                                 NetPacketSent *sent_cb)
745 {
746     NetQueue *queue;
747     int ret;
748 
749     if (sender->link_down || !sender->peer) {
750         return iov_size(iov, iovcnt);
751     }
752 
753     /* Let filters handle the packet first */
754     ret = filter_receive_iov(sender, NET_FILTER_DIRECTION_TX, sender,
755                              QEMU_NET_PACKET_FLAG_NONE, iov, iovcnt, sent_cb);
756     if (ret) {
757         return ret;
758     }
759 
760     ret = filter_receive_iov(sender->peer, NET_FILTER_DIRECTION_RX, sender,
761                              QEMU_NET_PACKET_FLAG_NONE, iov, iovcnt, sent_cb);
762     if (ret) {
763         return ret;
764     }
765 
766     queue = sender->peer->incoming_queue;
767 
768     return qemu_net_queue_send_iov(queue, sender,
769                                    QEMU_NET_PACKET_FLAG_NONE,
770                                    iov, iovcnt, sent_cb);
771 }
772 
773 ssize_t
774 qemu_sendv_packet(NetClientState *nc, const struct iovec *iov, int iovcnt)
775 {
776     return qemu_sendv_packet_async(nc, iov, iovcnt, NULL);
777 }
778 
779 NetClientState *qemu_find_netdev(const char *id)
780 {
781     NetClientState *nc;
782 
783     QTAILQ_FOREACH(nc, &net_clients, next) {
784         if (nc->info->type == NET_CLIENT_DRIVER_NIC)
785             continue;
786         if (!strcmp(nc->name, id)) {
787             return nc;
788         }
789     }
790 
791     return NULL;
792 }
793 
794 int qemu_find_net_clients_except(const char *id, NetClientState **ncs,
795                                  NetClientDriver type, int max)
796 {
797     NetClientState *nc;
798     int ret = 0;
799 
800     QTAILQ_FOREACH(nc, &net_clients, next) {
801         if (nc->info->type == type) {
802             continue;
803         }
804         if (!id || !strcmp(nc->name, id)) {
805             if (ret < max) {
806                 ncs[ret] = nc;
807             }
808             ret++;
809         }
810     }
811 
812     return ret;
813 }
814 
815 static int nic_get_free_idx(void)
816 {
817     int index;
818 
819     for (index = 0; index < MAX_NICS; index++)
820         if (!nd_table[index].used)
821             return index;
822     return -1;
823 }
824 
825 int qemu_show_nic_models(const char *arg, const char *const *models)
826 {
827     int i;
828 
829     if (!arg || !is_help_option(arg)) {
830         return 0;
831     }
832 
833     fprintf(stderr, "qemu: Supported NIC models: ");
834     for (i = 0 ; models[i]; i++)
835         fprintf(stderr, "%s%c", models[i], models[i+1] ? ',' : '\n');
836     return 1;
837 }
838 
839 void qemu_check_nic_model(NICInfo *nd, const char *model)
840 {
841     const char *models[2];
842 
843     models[0] = model;
844     models[1] = NULL;
845 
846     if (qemu_show_nic_models(nd->model, models))
847         exit(0);
848     if (qemu_find_nic_model(nd, models, model) < 0)
849         exit(1);
850 }
851 
852 int qemu_find_nic_model(NICInfo *nd, const char * const *models,
853                         const char *default_model)
854 {
855     int i;
856 
857     if (!nd->model)
858         nd->model = g_strdup(default_model);
859 
860     for (i = 0 ; models[i]; i++) {
861         if (strcmp(nd->model, models[i]) == 0)
862             return i;
863     }
864 
865     error_report("Unsupported NIC model: %s", nd->model);
866     return -1;
867 }
868 
869 static int net_init_nic(const Netdev *netdev, const char *name,
870                         NetClientState *peer, Error **errp)
871 {
872     int idx;
873     NICInfo *nd;
874     const NetLegacyNicOptions *nic;
875 
876     assert(netdev->type == NET_CLIENT_DRIVER_NIC);
877     nic = &netdev->u.nic;
878 
879     idx = nic_get_free_idx();
880     if (idx == -1 || nb_nics >= MAX_NICS) {
881         error_setg(errp, "too many NICs");
882         return -1;
883     }
884 
885     nd = &nd_table[idx];
886 
887     memset(nd, 0, sizeof(*nd));
888 
889     if (nic->has_netdev) {
890         nd->netdev = qemu_find_netdev(nic->netdev);
891         if (!nd->netdev) {
892             error_setg(errp, "netdev '%s' not found", nic->netdev);
893             return -1;
894         }
895     } else {
896         assert(peer);
897         nd->netdev = peer;
898     }
899     nd->name = g_strdup(name);
900     if (nic->has_model) {
901         nd->model = g_strdup(nic->model);
902     }
903     if (nic->has_addr) {
904         nd->devaddr = g_strdup(nic->addr);
905     }
906 
907     if (nic->has_macaddr &&
908         net_parse_macaddr(nd->macaddr.a, nic->macaddr) < 0) {
909         error_setg(errp, "invalid syntax for ethernet address");
910         return -1;
911     }
912     if (nic->has_macaddr &&
913         is_multicast_ether_addr(nd->macaddr.a)) {
914         error_setg(errp,
915                    "NIC cannot have multicast MAC address (odd 1st byte)");
916         return -1;
917     }
918     qemu_macaddr_default_if_unset(&nd->macaddr);
919 
920     if (nic->has_vectors) {
921         if (nic->vectors > 0x7ffffff) {
922             error_setg(errp, "invalid # of vectors: %"PRIu32, nic->vectors);
923             return -1;
924         }
925         nd->nvectors = nic->vectors;
926     } else {
927         nd->nvectors = DEV_NVECTORS_UNSPECIFIED;
928     }
929 
930     nd->used = 1;
931     nb_nics++;
932 
933     return idx;
934 }
935 
936 
937 static int (* const net_client_init_fun[NET_CLIENT_DRIVER__MAX])(
938     const Netdev *netdev,
939     const char *name,
940     NetClientState *peer, Error **errp) = {
941         [NET_CLIENT_DRIVER_NIC]       = net_init_nic,
942 #ifdef CONFIG_SLIRP
943         [NET_CLIENT_DRIVER_USER]      = net_init_slirp,
944 #endif
945         [NET_CLIENT_DRIVER_TAP]       = net_init_tap,
946         [NET_CLIENT_DRIVER_SOCKET]    = net_init_socket,
947 #ifdef CONFIG_VDE
948         [NET_CLIENT_DRIVER_VDE]       = net_init_vde,
949 #endif
950 #ifdef CONFIG_NETMAP
951         [NET_CLIENT_DRIVER_NETMAP]    = net_init_netmap,
952 #endif
953         [NET_CLIENT_DRIVER_DUMP]      = net_init_dump,
954 #ifdef CONFIG_NET_BRIDGE
955         [NET_CLIENT_DRIVER_BRIDGE]    = net_init_bridge,
956 #endif
957         [NET_CLIENT_DRIVER_HUBPORT]   = net_init_hubport,
958 #ifdef CONFIG_VHOST_NET_USED
959         [NET_CLIENT_DRIVER_VHOST_USER] = net_init_vhost_user,
960 #endif
961 #ifdef CONFIG_L2TPV3
962         [NET_CLIENT_DRIVER_L2TPV3]    = net_init_l2tpv3,
963 #endif
964 };
965 
966 
967 static int net_client_init1(const void *object, bool is_netdev, Error **errp)
968 {
969     Netdev legacy = {0};
970     const Netdev *netdev;
971     const char *name;
972     NetClientState *peer = NULL;
973 
974     if (is_netdev) {
975         netdev = object;
976         name = netdev->id;
977 
978         if (netdev->type == NET_CLIENT_DRIVER_DUMP ||
979             netdev->type == NET_CLIENT_DRIVER_NIC ||
980             !net_client_init_fun[netdev->type]) {
981             error_setg(errp, QERR_INVALID_PARAMETER_VALUE, "type",
982                        "a netdev backend type");
983             return -1;
984         }
985     } else {
986         const NetLegacy *net = object;
987         const NetLegacyOptions *opts = net->opts;
988         legacy.id = net->id;
989         netdev = &legacy;
990         /* missing optional values have been initialized to "all bits zero" */
991         name = net->has_id ? net->id : net->name;
992 
993         /* Map the old options to the new flat type */
994         switch (opts->type) {
995         case NET_LEGACY_OPTIONS_KIND_NONE:
996             return 0; /* nothing to do */
997         case NET_LEGACY_OPTIONS_KIND_NIC:
998             legacy.type = NET_CLIENT_DRIVER_NIC;
999             legacy.u.nic = *opts->u.nic.data;
1000             break;
1001         case NET_LEGACY_OPTIONS_KIND_USER:
1002             legacy.type = NET_CLIENT_DRIVER_USER;
1003             legacy.u.user = *opts->u.user.data;
1004             break;
1005         case NET_LEGACY_OPTIONS_KIND_TAP:
1006             legacy.type = NET_CLIENT_DRIVER_TAP;
1007             legacy.u.tap = *opts->u.tap.data;
1008             break;
1009         case NET_LEGACY_OPTIONS_KIND_L2TPV3:
1010             legacy.type = NET_CLIENT_DRIVER_L2TPV3;
1011             legacy.u.l2tpv3 = *opts->u.l2tpv3.data;
1012             break;
1013         case NET_LEGACY_OPTIONS_KIND_SOCKET:
1014             legacy.type = NET_CLIENT_DRIVER_SOCKET;
1015             legacy.u.socket = *opts->u.socket.data;
1016             break;
1017         case NET_LEGACY_OPTIONS_KIND_VDE:
1018             legacy.type = NET_CLIENT_DRIVER_VDE;
1019             legacy.u.vde = *opts->u.vde.data;
1020             break;
1021         case NET_LEGACY_OPTIONS_KIND_DUMP:
1022             legacy.type = NET_CLIENT_DRIVER_DUMP;
1023             legacy.u.dump = *opts->u.dump.data;
1024             break;
1025         case NET_LEGACY_OPTIONS_KIND_BRIDGE:
1026             legacy.type = NET_CLIENT_DRIVER_BRIDGE;
1027             legacy.u.bridge = *opts->u.bridge.data;
1028             break;
1029         case NET_LEGACY_OPTIONS_KIND_NETMAP:
1030             legacy.type = NET_CLIENT_DRIVER_NETMAP;
1031             legacy.u.netmap = *opts->u.netmap.data;
1032             break;
1033         case NET_LEGACY_OPTIONS_KIND_VHOST_USER:
1034             legacy.type = NET_CLIENT_DRIVER_VHOST_USER;
1035             legacy.u.vhost_user = *opts->u.vhost_user.data;
1036             break;
1037         default:
1038             abort();
1039         }
1040 
1041         if (!net_client_init_fun[netdev->type]) {
1042             error_setg(errp, QERR_INVALID_PARAMETER_VALUE, "type",
1043                        "a net backend type (maybe it is not compiled "
1044                        "into this binary)");
1045             return -1;
1046         }
1047 
1048         /* Do not add to a vlan if it's a nic with a netdev= parameter. */
1049         if (netdev->type != NET_CLIENT_DRIVER_NIC ||
1050             !opts->u.nic.data->has_netdev) {
1051             peer = net_hub_add_port(net->has_vlan ? net->vlan : 0, NULL);
1052         }
1053     }
1054 
1055     if (net_client_init_fun[netdev->type](netdev, name, peer, errp) < 0) {
1056         /* FIXME drop when all init functions store an Error */
1057         if (errp && !*errp) {
1058             error_setg(errp, QERR_DEVICE_INIT_FAILED,
1059                        NetClientDriver_lookup[netdev->type]);
1060         }
1061         return -1;
1062     }
1063     return 0;
1064 }
1065 
1066 
1067 int net_client_init(QemuOpts *opts, bool is_netdev, Error **errp)
1068 {
1069     void *object = NULL;
1070     Error *err = NULL;
1071     int ret = -1;
1072     Visitor *v = opts_visitor_new(opts);
1073 
1074     {
1075         /* Parse convenience option format ip6-net=fec0::0[/64] */
1076         const char *ip6_net = qemu_opt_get(opts, "ipv6-net");
1077 
1078         if (ip6_net) {
1079             char buf[strlen(ip6_net) + 1];
1080 
1081             if (get_str_sep(buf, sizeof(buf), &ip6_net, '/') < 0) {
1082                 /* Default 64bit prefix length.  */
1083                 qemu_opt_set(opts, "ipv6-prefix", ip6_net, &error_abort);
1084                 qemu_opt_set_number(opts, "ipv6-prefixlen", 64, &error_abort);
1085             } else {
1086                 /* User-specified prefix length.  */
1087                 unsigned long len;
1088                 int err;
1089 
1090                 qemu_opt_set(opts, "ipv6-prefix", buf, &error_abort);
1091                 err = qemu_strtoul(ip6_net, NULL, 10, &len);
1092 
1093                 if (err) {
1094                     error_setg(errp, QERR_INVALID_PARAMETER_VALUE,
1095                               "ipv6-prefix", "a number");
1096                 } else {
1097                     qemu_opt_set_number(opts, "ipv6-prefixlen", len,
1098                                         &error_abort);
1099                 }
1100             }
1101             qemu_opt_unset(opts, "ipv6-net");
1102         }
1103     }
1104 
1105     if (is_netdev) {
1106         visit_type_Netdev(v, NULL, (Netdev **)&object, &err);
1107     } else {
1108         visit_type_NetLegacy(v, NULL, (NetLegacy **)&object, &err);
1109     }
1110 
1111     if (!err) {
1112         ret = net_client_init1(object, is_netdev, &err);
1113     }
1114 
1115     if (is_netdev) {
1116         qapi_free_Netdev(object);
1117     } else {
1118         qapi_free_NetLegacy(object);
1119     }
1120 
1121     error_propagate(errp, err);
1122     visit_free(v);
1123     return ret;
1124 }
1125 
1126 
1127 static int net_host_check_device(const char *device)
1128 {
1129     int i;
1130     for (i = 0; host_net_devices[i]; i++) {
1131         if (!strncmp(host_net_devices[i], device,
1132                      strlen(host_net_devices[i]))) {
1133             return 1;
1134         }
1135     }
1136 
1137     return 0;
1138 }
1139 
1140 void hmp_host_net_add(Monitor *mon, const QDict *qdict)
1141 {
1142     const char *device = qdict_get_str(qdict, "device");
1143     const char *opts_str = qdict_get_try_str(qdict, "opts");
1144     Error *local_err = NULL;
1145     QemuOpts *opts;
1146 
1147     if (!net_host_check_device(device)) {
1148         monitor_printf(mon, "invalid host network device %s\n", device);
1149         return;
1150     }
1151 
1152     opts = qemu_opts_parse_noisily(qemu_find_opts("net"),
1153                                    opts_str ? opts_str : "", false);
1154     if (!opts) {
1155         return;
1156     }
1157 
1158     qemu_opt_set(opts, "type", device, &error_abort);
1159 
1160     net_client_init(opts, false, &local_err);
1161     if (local_err) {
1162         error_report_err(local_err);
1163         monitor_printf(mon, "adding host network device %s failed\n", device);
1164     }
1165 }
1166 
1167 void hmp_host_net_remove(Monitor *mon, const QDict *qdict)
1168 {
1169     NetClientState *nc;
1170     int vlan_id = qdict_get_int(qdict, "vlan_id");
1171     const char *device = qdict_get_str(qdict, "device");
1172 
1173     nc = net_hub_find_client_by_name(vlan_id, device);
1174     if (!nc) {
1175         error_report("Host network device '%s' on hub '%d' not found",
1176                      device, vlan_id);
1177         return;
1178     }
1179     if (nc->info->type == NET_CLIENT_DRIVER_NIC) {
1180         error_report("invalid host network device '%s'", device);
1181         return;
1182     }
1183 
1184     qemu_del_net_client(nc->peer);
1185     qemu_del_net_client(nc);
1186     qemu_opts_del(qemu_opts_find(qemu_find_opts("net"), device));
1187 }
1188 
1189 void netdev_add(QemuOpts *opts, Error **errp)
1190 {
1191     net_client_init(opts, true, errp);
1192 }
1193 
1194 void qmp_netdev_add(QDict *qdict, QObject **ret, Error **errp)
1195 {
1196     Error *local_err = NULL;
1197     QemuOptsList *opts_list;
1198     QemuOpts *opts;
1199 
1200     opts_list = qemu_find_opts_err("netdev", &local_err);
1201     if (local_err) {
1202         goto out;
1203     }
1204 
1205     opts = qemu_opts_from_qdict(opts_list, qdict, &local_err);
1206     if (local_err) {
1207         goto out;
1208     }
1209 
1210     netdev_add(opts, &local_err);
1211     if (local_err) {
1212         qemu_opts_del(opts);
1213         goto out;
1214     }
1215 
1216 out:
1217     error_propagate(errp, local_err);
1218 }
1219 
1220 void qmp_netdev_del(const char *id, Error **errp)
1221 {
1222     NetClientState *nc;
1223     QemuOpts *opts;
1224 
1225     nc = qemu_find_netdev(id);
1226     if (!nc) {
1227         error_set(errp, ERROR_CLASS_DEVICE_NOT_FOUND,
1228                   "Device '%s' not found", id);
1229         return;
1230     }
1231 
1232     opts = qemu_opts_find(qemu_find_opts_err("netdev", NULL), id);
1233     if (!opts) {
1234         error_setg(errp, "Device '%s' is not a netdev", id);
1235         return;
1236     }
1237 
1238     qemu_del_net_client(nc);
1239     qemu_opts_del(opts);
1240 }
1241 
1242 static void netfilter_print_info(Monitor *mon, NetFilterState *nf)
1243 {
1244     char *str;
1245     ObjectProperty *prop;
1246     ObjectPropertyIterator iter;
1247     Visitor *v;
1248 
1249     /* generate info str */
1250     object_property_iter_init(&iter, OBJECT(nf));
1251     while ((prop = object_property_iter_next(&iter))) {
1252         if (!strcmp(prop->name, "type")) {
1253             continue;
1254         }
1255         v = string_output_visitor_new(false, &str);
1256         object_property_get(OBJECT(nf), v, prop->name, NULL);
1257         visit_complete(v, &str);
1258         visit_free(v);
1259         monitor_printf(mon, ",%s=%s", prop->name, str);
1260         g_free(str);
1261     }
1262     monitor_printf(mon, "\n");
1263 }
1264 
1265 void print_net_client(Monitor *mon, NetClientState *nc)
1266 {
1267     NetFilterState *nf;
1268 
1269     monitor_printf(mon, "%s: index=%d,type=%s,%s\n", nc->name,
1270                    nc->queue_index,
1271                    NetClientDriver_lookup[nc->info->type],
1272                    nc->info_str);
1273     if (!QTAILQ_EMPTY(&nc->filters)) {
1274         monitor_printf(mon, "filters:\n");
1275     }
1276     QTAILQ_FOREACH(nf, &nc->filters, next) {
1277         char *path = object_get_canonical_path_component(OBJECT(nf));
1278 
1279         monitor_printf(mon, "  - %s: type=%s", path,
1280                        object_get_typename(OBJECT(nf)));
1281         netfilter_print_info(mon, nf);
1282         g_free(path);
1283     }
1284 }
1285 
1286 RxFilterInfoList *qmp_query_rx_filter(bool has_name, const char *name,
1287                                       Error **errp)
1288 {
1289     NetClientState *nc;
1290     RxFilterInfoList *filter_list = NULL, *last_entry = NULL;
1291 
1292     QTAILQ_FOREACH(nc, &net_clients, next) {
1293         RxFilterInfoList *entry;
1294         RxFilterInfo *info;
1295 
1296         if (has_name && strcmp(nc->name, name) != 0) {
1297             continue;
1298         }
1299 
1300         /* only query rx-filter information of NIC */
1301         if (nc->info->type != NET_CLIENT_DRIVER_NIC) {
1302             if (has_name) {
1303                 error_setg(errp, "net client(%s) isn't a NIC", name);
1304                 return NULL;
1305             }
1306             continue;
1307         }
1308 
1309         /* only query information on queue 0 since the info is per nic,
1310          * not per queue
1311          */
1312         if (nc->queue_index != 0)
1313             continue;
1314 
1315         if (nc->info->query_rx_filter) {
1316             info = nc->info->query_rx_filter(nc);
1317             entry = g_malloc0(sizeof(*entry));
1318             entry->value = info;
1319 
1320             if (!filter_list) {
1321                 filter_list = entry;
1322             } else {
1323                 last_entry->next = entry;
1324             }
1325             last_entry = entry;
1326         } else if (has_name) {
1327             error_setg(errp, "net client(%s) doesn't support"
1328                        " rx-filter querying", name);
1329             return NULL;
1330         }
1331 
1332         if (has_name) {
1333             break;
1334         }
1335     }
1336 
1337     if (filter_list == NULL && has_name) {
1338         error_setg(errp, "invalid net client name: %s", name);
1339     }
1340 
1341     return filter_list;
1342 }
1343 
1344 void hmp_info_network(Monitor *mon, const QDict *qdict)
1345 {
1346     NetClientState *nc, *peer;
1347     NetClientDriver type;
1348 
1349     net_hub_info(mon);
1350 
1351     QTAILQ_FOREACH(nc, &net_clients, next) {
1352         peer = nc->peer;
1353         type = nc->info->type;
1354 
1355         /* Skip if already printed in hub info */
1356         if (net_hub_id_for_client(nc, NULL) == 0) {
1357             continue;
1358         }
1359 
1360         if (!peer || type == NET_CLIENT_DRIVER_NIC) {
1361             print_net_client(mon, nc);
1362         } /* else it's a netdev connected to a NIC, printed with the NIC */
1363         if (peer && type == NET_CLIENT_DRIVER_NIC) {
1364             monitor_printf(mon, " \\ ");
1365             print_net_client(mon, peer);
1366         }
1367     }
1368 }
1369 
1370 void qmp_set_link(const char *name, bool up, Error **errp)
1371 {
1372     NetClientState *ncs[MAX_QUEUE_NUM];
1373     NetClientState *nc;
1374     int queues, i;
1375 
1376     queues = qemu_find_net_clients_except(name, ncs,
1377                                           NET_CLIENT_DRIVER__MAX,
1378                                           MAX_QUEUE_NUM);
1379 
1380     if (queues == 0) {
1381         error_set(errp, ERROR_CLASS_DEVICE_NOT_FOUND,
1382                   "Device '%s' not found", name);
1383         return;
1384     }
1385     nc = ncs[0];
1386 
1387     for (i = 0; i < queues; i++) {
1388         ncs[i]->link_down = !up;
1389     }
1390 
1391     if (nc->info->link_status_changed) {
1392         nc->info->link_status_changed(nc);
1393     }
1394 
1395     if (nc->peer) {
1396         /* Change peer link only if the peer is NIC and then notify peer.
1397          * If the peer is a HUBPORT or a backend, we do not change the
1398          * link status.
1399          *
1400          * This behavior is compatible with qemu vlans where there could be
1401          * multiple clients that can still communicate with each other in
1402          * disconnected mode. For now maintain this compatibility.
1403          */
1404         if (nc->peer->info->type == NET_CLIENT_DRIVER_NIC) {
1405             for (i = 0; i < queues; i++) {
1406                 ncs[i]->peer->link_down = !up;
1407             }
1408         }
1409         if (nc->peer->info->link_status_changed) {
1410             nc->peer->info->link_status_changed(nc->peer);
1411         }
1412     }
1413 }
1414 
1415 static void net_vm_change_state_handler(void *opaque, int running,
1416                                         RunState state)
1417 {
1418     NetClientState *nc;
1419     NetClientState *tmp;
1420 
1421     QTAILQ_FOREACH_SAFE(nc, &net_clients, next, tmp) {
1422         if (running) {
1423             /* Flush queued packets and wake up backends. */
1424             if (nc->peer && qemu_can_send_packet(nc)) {
1425                 qemu_flush_queued_packets(nc->peer);
1426             }
1427         } else {
1428             /* Complete all queued packets, to guarantee we don't modify
1429              * state later when VM is not running.
1430              */
1431             qemu_flush_or_purge_queued_packets(nc, true);
1432         }
1433     }
1434 }
1435 
1436 void net_cleanup(void)
1437 {
1438     NetClientState *nc;
1439 
1440     /* We may del multiple entries during qemu_del_net_client(),
1441      * so QTAILQ_FOREACH_SAFE() is also not safe here.
1442      */
1443     while (!QTAILQ_EMPTY(&net_clients)) {
1444         nc = QTAILQ_FIRST(&net_clients);
1445         if (nc->info->type == NET_CLIENT_DRIVER_NIC) {
1446             qemu_del_nic(qemu_get_nic(nc));
1447         } else {
1448             qemu_del_net_client(nc);
1449         }
1450     }
1451 
1452     qemu_del_vm_change_state_handler(net_change_state_entry);
1453 }
1454 
1455 void net_check_clients(void)
1456 {
1457     NetClientState *nc;
1458     int i;
1459 
1460     net_hub_check_clients();
1461 
1462     QTAILQ_FOREACH(nc, &net_clients, next) {
1463         if (!nc->peer) {
1464             fprintf(stderr, "Warning: %s %s has no peer\n",
1465                     nc->info->type == NET_CLIENT_DRIVER_NIC ?
1466                     "nic" : "netdev", nc->name);
1467         }
1468     }
1469 
1470     /* Check that all NICs requested via -net nic actually got created.
1471      * NICs created via -device don't need to be checked here because
1472      * they are always instantiated.
1473      */
1474     for (i = 0; i < MAX_NICS; i++) {
1475         NICInfo *nd = &nd_table[i];
1476         if (nd->used && !nd->instantiated) {
1477             fprintf(stderr, "Warning: requested NIC (%s, model %s) "
1478                     "was not created (not supported by this machine?)\n",
1479                     nd->name ? nd->name : "anonymous",
1480                     nd->model ? nd->model : "unspecified");
1481         }
1482     }
1483 }
1484 
1485 static int net_init_client(void *dummy, QemuOpts *opts, Error **errp)
1486 {
1487     Error *local_err = NULL;
1488 
1489     net_client_init(opts, false, &local_err);
1490     if (local_err) {
1491         error_report_err(local_err);
1492         return -1;
1493     }
1494 
1495     return 0;
1496 }
1497 
1498 static int net_init_netdev(void *dummy, QemuOpts *opts, Error **errp)
1499 {
1500     Error *local_err = NULL;
1501     int ret;
1502 
1503     ret = net_client_init(opts, true, &local_err);
1504     if (local_err) {
1505         error_report_err(local_err);
1506         return -1;
1507     }
1508 
1509     return ret;
1510 }
1511 
1512 int net_init_clients(void)
1513 {
1514     QemuOptsList *net = qemu_find_opts("net");
1515 
1516     net_change_state_entry =
1517         qemu_add_vm_change_state_handler(net_vm_change_state_handler, NULL);
1518 
1519     QTAILQ_INIT(&net_clients);
1520 
1521     if (qemu_opts_foreach(qemu_find_opts("netdev"),
1522                           net_init_netdev, NULL, NULL)) {
1523         return -1;
1524     }
1525 
1526     if (qemu_opts_foreach(net, net_init_client, NULL, NULL)) {
1527         return -1;
1528     }
1529 
1530     return 0;
1531 }
1532 
1533 int net_client_parse(QemuOptsList *opts_list, const char *optarg)
1534 {
1535 #if defined(CONFIG_SLIRP)
1536     int ret;
1537     if (net_slirp_parse_legacy(opts_list, optarg, &ret)) {
1538         return ret;
1539     }
1540 #endif
1541 
1542     if (!qemu_opts_parse_noisily(opts_list, optarg, true)) {
1543         return -1;
1544     }
1545 
1546     return 0;
1547 }
1548 
1549 /* From FreeBSD */
1550 /* XXX: optimize */
1551 unsigned compute_mcast_idx(const uint8_t *ep)
1552 {
1553     uint32_t crc;
1554     int carry, i, j;
1555     uint8_t b;
1556 
1557     crc = 0xffffffff;
1558     for (i = 0; i < 6; i++) {
1559         b = *ep++;
1560         for (j = 0; j < 8; j++) {
1561             carry = ((crc & 0x80000000L) ? 1 : 0) ^ (b & 0x01);
1562             crc <<= 1;
1563             b >>= 1;
1564             if (carry) {
1565                 crc = ((crc ^ POLYNOMIAL) | carry);
1566             }
1567         }
1568     }
1569     return crc >> 26;
1570 }
1571 
1572 QemuOptsList qemu_netdev_opts = {
1573     .name = "netdev",
1574     .implied_opt_name = "type",
1575     .head = QTAILQ_HEAD_INITIALIZER(qemu_netdev_opts.head),
1576     .desc = {
1577         /*
1578          * no elements => accept any params
1579          * validation will happen later
1580          */
1581         { /* end of list */ }
1582     },
1583 };
1584 
1585 QemuOptsList qemu_net_opts = {
1586     .name = "net",
1587     .implied_opt_name = "type",
1588     .head = QTAILQ_HEAD_INITIALIZER(qemu_net_opts.head),
1589     .desc = {
1590         /*
1591          * no elements => accept any params
1592          * validation will happen later
1593          */
1594         { /* end of list */ }
1595     },
1596 };
1597 
1598 void net_socket_rs_init(SocketReadState *rs,
1599                         SocketReadStateFinalize *finalize)
1600 {
1601     rs->state = 0;
1602     rs->index = 0;
1603     rs->packet_len = 0;
1604     memset(rs->buf, 0, sizeof(rs->buf));
1605     rs->finalize = finalize;
1606 }
1607 
1608 /*
1609  * Returns
1610  * 0: success
1611  * -1: error occurs
1612  */
1613 int net_fill_rstate(SocketReadState *rs, const uint8_t *buf, int size)
1614 {
1615     unsigned int l;
1616 
1617     while (size > 0) {
1618         /* reassemble a packet from the network */
1619         switch (rs->state) { /* 0 = getting length, 1 = getting data */
1620         case 0:
1621             l = 4 - rs->index;
1622             if (l > size) {
1623                 l = size;
1624             }
1625             memcpy(rs->buf + rs->index, buf, l);
1626             buf += l;
1627             size -= l;
1628             rs->index += l;
1629             if (rs->index == 4) {
1630                 /* got length */
1631                 rs->packet_len = ntohl(*(uint32_t *)rs->buf);
1632                 rs->index = 0;
1633                 rs->state = 1;
1634             }
1635             break;
1636         case 1:
1637             l = rs->packet_len - rs->index;
1638             if (l > size) {
1639                 l = size;
1640             }
1641             if (rs->index + l <= sizeof(rs->buf)) {
1642                 memcpy(rs->buf + rs->index, buf, l);
1643             } else {
1644                 fprintf(stderr, "serious error: oversized packet received,"
1645                     "connection terminated.\n");
1646                 rs->index = rs->state = 0;
1647                 return -1;
1648             }
1649 
1650             rs->index += l;
1651             buf += l;
1652             size -= l;
1653             if (rs->index >= rs->packet_len) {
1654                 rs->index = 0;
1655                 rs->state = 0;
1656                 assert(rs->finalize);
1657                 rs->finalize(rs);
1658             }
1659             break;
1660         }
1661     }
1662 
1663     assert(size == 0);
1664     return 0;
1665 }
1666