xref: /qemu/net/net.c (revision ca61e750)
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 
25 #include "qemu/osdep.h"
26 
27 #include "net/net.h"
28 #include "clients.h"
29 #include "hub.h"
30 #include "hw/qdev-properties.h"
31 #include "net/slirp.h"
32 #include "net/eth.h"
33 #include "util.h"
34 
35 #include "monitor/monitor.h"
36 #include "qemu/help_option.h"
37 #include "qapi/qapi-commands-net.h"
38 #include "qapi/qapi-visit-net.h"
39 #include "qapi/qmp/qdict.h"
40 #include "qapi/qmp/qerror.h"
41 #include "qemu/error-report.h"
42 #include "qemu/sockets.h"
43 #include "qemu/cutils.h"
44 #include "qemu/config-file.h"
45 #include "qemu/ctype.h"
46 #include "qemu/id.h"
47 #include "qemu/iov.h"
48 #include "qemu/qemu-print.h"
49 #include "qemu/main-loop.h"
50 #include "qemu/option.h"
51 #include "qapi/error.h"
52 #include "qapi/opts-visitor.h"
53 #include "sysemu/runstate.h"
54 #include "net/colo-compare.h"
55 #include "net/filter.h"
56 #include "qapi/string-output-visitor.h"
57 
58 /* Net bridge is currently not supported for W32. */
59 #if !defined(_WIN32)
60 # define CONFIG_NET_BRIDGE
61 #endif
62 
63 static VMChangeStateEntry *net_change_state_entry;
64 static QTAILQ_HEAD(, NetClientState) net_clients;
65 
66 /***********************************************************/
67 /* network device redirectors */
68 
69 int parse_host_port(struct sockaddr_in *saddr, const char *str,
70                     Error **errp)
71 {
72     gchar **substrings;
73     struct hostent *he;
74     const char *addr, *p, *r;
75     int port, ret = 0;
76 
77     memset(saddr, 0, sizeof(*saddr));
78 
79     substrings = g_strsplit(str, ":", 2);
80     if (!substrings || !substrings[0] || !substrings[1]) {
81         error_setg(errp, "host address '%s' doesn't contain ':' "
82                    "separating host from port", str);
83         ret = -1;
84         goto out;
85     }
86 
87     addr = substrings[0];
88     p = substrings[1];
89 
90     saddr->sin_family = AF_INET;
91     if (addr[0] == '\0') {
92         saddr->sin_addr.s_addr = 0;
93     } else {
94         if (qemu_isdigit(addr[0])) {
95             if (!inet_aton(addr, &saddr->sin_addr)) {
96                 error_setg(errp, "host address '%s' is not a valid "
97                            "IPv4 address", addr);
98                 ret = -1;
99                 goto out;
100             }
101         } else {
102             he = gethostbyname(addr);
103             if (he == NULL) {
104                 error_setg(errp, "can't resolve host address '%s'", addr);
105                 ret = -1;
106                 goto out;
107             }
108             saddr->sin_addr = *(struct in_addr *)he->h_addr;
109         }
110     }
111     port = strtol(p, (char **)&r, 0);
112     if (r == p) {
113         error_setg(errp, "port number '%s' is invalid", p);
114         ret = -1;
115         goto out;
116     }
117     saddr->sin_port = htons(port);
118 
119 out:
120     g_strfreev(substrings);
121     return ret;
122 }
123 
124 char *qemu_mac_strdup_printf(const uint8_t *macaddr)
125 {
126     return g_strdup_printf("%.2x:%.2x:%.2x:%.2x:%.2x:%.2x",
127                            macaddr[0], macaddr[1], macaddr[2],
128                            macaddr[3], macaddr[4], macaddr[5]);
129 }
130 
131 void qemu_format_nic_info_str(NetClientState *nc, uint8_t macaddr[6])
132 {
133     snprintf(nc->info_str, sizeof(nc->info_str),
134              "model=%s,macaddr=%02x:%02x:%02x:%02x:%02x:%02x",
135              nc->model,
136              macaddr[0], macaddr[1], macaddr[2],
137              macaddr[3], macaddr[4], macaddr[5]);
138 }
139 
140 static int mac_table[256] = {0};
141 
142 static void qemu_macaddr_set_used(MACAddr *macaddr)
143 {
144     int index;
145 
146     for (index = 0x56; index < 0xFF; index++) {
147         if (macaddr->a[5] == index) {
148             mac_table[index]++;
149         }
150     }
151 }
152 
153 static void qemu_macaddr_set_free(MACAddr *macaddr)
154 {
155     int index;
156     static const MACAddr base = { .a = { 0x52, 0x54, 0x00, 0x12, 0x34, 0 } };
157 
158     if (memcmp(macaddr->a, &base.a, (sizeof(base.a) - 1)) != 0) {
159         return;
160     }
161     for (index = 0x56; index < 0xFF; index++) {
162         if (macaddr->a[5] == index) {
163             mac_table[index]--;
164         }
165     }
166 }
167 
168 static int qemu_macaddr_get_free(void)
169 {
170     int index;
171 
172     for (index = 0x56; index < 0xFF; index++) {
173         if (mac_table[index] == 0) {
174             return index;
175         }
176     }
177 
178     return -1;
179 }
180 
181 void qemu_macaddr_default_if_unset(MACAddr *macaddr)
182 {
183     static const MACAddr zero = { .a = { 0,0,0,0,0,0 } };
184     static const MACAddr base = { .a = { 0x52, 0x54, 0x00, 0x12, 0x34, 0 } };
185 
186     if (memcmp(macaddr, &zero, sizeof(zero)) != 0) {
187         if (memcmp(macaddr->a, &base.a, (sizeof(base.a) - 1)) != 0) {
188             return;
189         } else {
190             qemu_macaddr_set_used(macaddr);
191             return;
192         }
193     }
194 
195     macaddr->a[0] = 0x52;
196     macaddr->a[1] = 0x54;
197     macaddr->a[2] = 0x00;
198     macaddr->a[3] = 0x12;
199     macaddr->a[4] = 0x34;
200     macaddr->a[5] = qemu_macaddr_get_free();
201     qemu_macaddr_set_used(macaddr);
202 }
203 
204 /**
205  * Generate a name for net client
206  *
207  * Only net clients created with the legacy -net option and NICs need this.
208  */
209 static char *assign_name(NetClientState *nc1, const char *model)
210 {
211     NetClientState *nc;
212     int id = 0;
213 
214     QTAILQ_FOREACH(nc, &net_clients, next) {
215         if (nc == nc1) {
216             continue;
217         }
218         if (strcmp(nc->model, model) == 0) {
219             id++;
220         }
221     }
222 
223     return g_strdup_printf("%s.%d", model, id);
224 }
225 
226 static void qemu_net_client_destructor(NetClientState *nc)
227 {
228     g_free(nc);
229 }
230 static ssize_t qemu_deliver_packet_iov(NetClientState *sender,
231                                        unsigned flags,
232                                        const struct iovec *iov,
233                                        int iovcnt,
234                                        void *opaque);
235 
236 static void qemu_net_client_setup(NetClientState *nc,
237                                   NetClientInfo *info,
238                                   NetClientState *peer,
239                                   const char *model,
240                                   const char *name,
241                                   NetClientDestructor *destructor,
242                                   bool is_datapath)
243 {
244     nc->info = info;
245     nc->model = g_strdup(model);
246     if (name) {
247         nc->name = g_strdup(name);
248     } else {
249         nc->name = assign_name(nc, model);
250     }
251 
252     if (peer) {
253         assert(!peer->peer);
254         nc->peer = peer;
255         peer->peer = nc;
256     }
257     QTAILQ_INSERT_TAIL(&net_clients, nc, next);
258 
259     nc->incoming_queue = qemu_new_net_queue(qemu_deliver_packet_iov, nc);
260     nc->destructor = destructor;
261     nc->is_datapath = is_datapath;
262     QTAILQ_INIT(&nc->filters);
263 }
264 
265 NetClientState *qemu_new_net_client(NetClientInfo *info,
266                                     NetClientState *peer,
267                                     const char *model,
268                                     const char *name)
269 {
270     NetClientState *nc;
271 
272     assert(info->size >= sizeof(NetClientState));
273 
274     nc = g_malloc0(info->size);
275     qemu_net_client_setup(nc, info, peer, model, name,
276                           qemu_net_client_destructor, true);
277 
278     return nc;
279 }
280 
281 NetClientState *qemu_new_net_control_client(NetClientInfo *info,
282                                             NetClientState *peer,
283                                             const char *model,
284                                             const char *name)
285 {
286     NetClientState *nc;
287 
288     assert(info->size >= sizeof(NetClientState));
289 
290     nc = g_malloc0(info->size);
291     qemu_net_client_setup(nc, info, peer, model, name,
292                           qemu_net_client_destructor, false);
293 
294     return nc;
295 }
296 
297 NICState *qemu_new_nic(NetClientInfo *info,
298                        NICConf *conf,
299                        const char *model,
300                        const char *name,
301                        void *opaque)
302 {
303     NetClientState **peers = conf->peers.ncs;
304     NICState *nic;
305     int i, queues = MAX(1, conf->peers.queues);
306 
307     assert(info->type == NET_CLIENT_DRIVER_NIC);
308     assert(info->size >= sizeof(NICState));
309 
310     nic = g_malloc0(info->size + sizeof(NetClientState) * queues);
311     nic->ncs = (void *)nic + info->size;
312     nic->conf = conf;
313     nic->opaque = opaque;
314 
315     for (i = 0; i < queues; i++) {
316         qemu_net_client_setup(&nic->ncs[i], info, peers[i], model, name,
317                               NULL, true);
318         nic->ncs[i].queue_index = i;
319     }
320 
321     return nic;
322 }
323 
324 NetClientState *qemu_get_subqueue(NICState *nic, int queue_index)
325 {
326     return nic->ncs + queue_index;
327 }
328 
329 NetClientState *qemu_get_queue(NICState *nic)
330 {
331     return qemu_get_subqueue(nic, 0);
332 }
333 
334 NICState *qemu_get_nic(NetClientState *nc)
335 {
336     NetClientState *nc0 = nc - nc->queue_index;
337 
338     return (NICState *)((void *)nc0 - nc->info->size);
339 }
340 
341 void *qemu_get_nic_opaque(NetClientState *nc)
342 {
343     NICState *nic = qemu_get_nic(nc);
344 
345     return nic->opaque;
346 }
347 
348 NetClientState *qemu_get_peer(NetClientState *nc, int queue_index)
349 {
350     assert(nc != NULL);
351     NetClientState *ncs = nc + queue_index;
352     return ncs->peer;
353 }
354 
355 static void qemu_cleanup_net_client(NetClientState *nc)
356 {
357     QTAILQ_REMOVE(&net_clients, nc, next);
358 
359     if (nc->info->cleanup) {
360         nc->info->cleanup(nc);
361     }
362 }
363 
364 static void qemu_free_net_client(NetClientState *nc)
365 {
366     if (nc->incoming_queue) {
367         qemu_del_net_queue(nc->incoming_queue);
368     }
369     if (nc->peer) {
370         nc->peer->peer = NULL;
371     }
372     g_free(nc->name);
373     g_free(nc->model);
374     if (nc->destructor) {
375         nc->destructor(nc);
376     }
377 }
378 
379 void qemu_del_net_client(NetClientState *nc)
380 {
381     NetClientState *ncs[MAX_QUEUE_NUM];
382     int queues, i;
383     NetFilterState *nf, *next;
384 
385     assert(nc->info->type != NET_CLIENT_DRIVER_NIC);
386 
387     /* If the NetClientState belongs to a multiqueue backend, we will change all
388      * other NetClientStates also.
389      */
390     queues = qemu_find_net_clients_except(nc->name, ncs,
391                                           NET_CLIENT_DRIVER_NIC,
392                                           MAX_QUEUE_NUM);
393     assert(queues != 0);
394 
395     QTAILQ_FOREACH_SAFE(nf, &nc->filters, next, next) {
396         object_unparent(OBJECT(nf));
397     }
398 
399     /* If there is a peer NIC, delete and cleanup client, but do not free. */
400     if (nc->peer && nc->peer->info->type == NET_CLIENT_DRIVER_NIC) {
401         NICState *nic = qemu_get_nic(nc->peer);
402         if (nic->peer_deleted) {
403             return;
404         }
405         nic->peer_deleted = true;
406 
407         for (i = 0; i < queues; i++) {
408             ncs[i]->peer->link_down = true;
409         }
410 
411         if (nc->peer->info->link_status_changed) {
412             nc->peer->info->link_status_changed(nc->peer);
413         }
414 
415         for (i = 0; i < queues; i++) {
416             qemu_cleanup_net_client(ncs[i]);
417         }
418 
419         return;
420     }
421 
422     for (i = 0; i < queues; i++) {
423         qemu_cleanup_net_client(ncs[i]);
424         qemu_free_net_client(ncs[i]);
425     }
426 }
427 
428 void qemu_del_nic(NICState *nic)
429 {
430     int i, queues = MAX(nic->conf->peers.queues, 1);
431 
432     qemu_macaddr_set_free(&nic->conf->macaddr);
433 
434     for (i = 0; i < queues; i++) {
435         NetClientState *nc = qemu_get_subqueue(nic, i);
436         /* If this is a peer NIC and peer has already been deleted, free it now. */
437         if (nic->peer_deleted) {
438             qemu_free_net_client(nc->peer);
439         } else if (nc->peer) {
440             /* if there are RX packets pending, complete them */
441             qemu_purge_queued_packets(nc->peer);
442         }
443     }
444 
445     for (i = queues - 1; i >= 0; i--) {
446         NetClientState *nc = qemu_get_subqueue(nic, i);
447 
448         qemu_cleanup_net_client(nc);
449         qemu_free_net_client(nc);
450     }
451 
452     g_free(nic);
453 }
454 
455 void qemu_foreach_nic(qemu_nic_foreach func, void *opaque)
456 {
457     NetClientState *nc;
458 
459     QTAILQ_FOREACH(nc, &net_clients, next) {
460         if (nc->info->type == NET_CLIENT_DRIVER_NIC) {
461             if (nc->queue_index == 0) {
462                 func(qemu_get_nic(nc), opaque);
463             }
464         }
465     }
466 }
467 
468 bool qemu_has_ufo(NetClientState *nc)
469 {
470     if (!nc || !nc->info->has_ufo) {
471         return false;
472     }
473 
474     return nc->info->has_ufo(nc);
475 }
476 
477 bool qemu_has_vnet_hdr(NetClientState *nc)
478 {
479     if (!nc || !nc->info->has_vnet_hdr) {
480         return false;
481     }
482 
483     return nc->info->has_vnet_hdr(nc);
484 }
485 
486 bool qemu_has_vnet_hdr_len(NetClientState *nc, int len)
487 {
488     if (!nc || !nc->info->has_vnet_hdr_len) {
489         return false;
490     }
491 
492     return nc->info->has_vnet_hdr_len(nc, len);
493 }
494 
495 void qemu_using_vnet_hdr(NetClientState *nc, bool enable)
496 {
497     if (!nc || !nc->info->using_vnet_hdr) {
498         return;
499     }
500 
501     nc->info->using_vnet_hdr(nc, enable);
502 }
503 
504 void qemu_set_offload(NetClientState *nc, int csum, int tso4, int tso6,
505                           int ecn, int ufo)
506 {
507     if (!nc || !nc->info->set_offload) {
508         return;
509     }
510 
511     nc->info->set_offload(nc, csum, tso4, tso6, ecn, ufo);
512 }
513 
514 void qemu_set_vnet_hdr_len(NetClientState *nc, int len)
515 {
516     if (!nc || !nc->info->set_vnet_hdr_len) {
517         return;
518     }
519 
520     nc->vnet_hdr_len = len;
521     nc->info->set_vnet_hdr_len(nc, len);
522 }
523 
524 int qemu_set_vnet_le(NetClientState *nc, bool is_le)
525 {
526 #if HOST_BIG_ENDIAN
527     if (!nc || !nc->info->set_vnet_le) {
528         return -ENOSYS;
529     }
530 
531     return nc->info->set_vnet_le(nc, is_le);
532 #else
533     return 0;
534 #endif
535 }
536 
537 int qemu_set_vnet_be(NetClientState *nc, bool is_be)
538 {
539 #if HOST_BIG_ENDIAN
540     return 0;
541 #else
542     if (!nc || !nc->info->set_vnet_be) {
543         return -ENOSYS;
544     }
545 
546     return nc->info->set_vnet_be(nc, is_be);
547 #endif
548 }
549 
550 int qemu_can_receive_packet(NetClientState *nc)
551 {
552     if (nc->receive_disabled) {
553         return 0;
554     } else if (nc->info->can_receive &&
555                !nc->info->can_receive(nc)) {
556         return 0;
557     }
558     return 1;
559 }
560 
561 int qemu_can_send_packet(NetClientState *sender)
562 {
563     int vm_running = runstate_is_running();
564 
565     if (!vm_running) {
566         return 0;
567     }
568 
569     if (!sender->peer) {
570         return 1;
571     }
572 
573     return qemu_can_receive_packet(sender->peer);
574 }
575 
576 static ssize_t filter_receive_iov(NetClientState *nc,
577                                   NetFilterDirection direction,
578                                   NetClientState *sender,
579                                   unsigned flags,
580                                   const struct iovec *iov,
581                                   int iovcnt,
582                                   NetPacketSent *sent_cb)
583 {
584     ssize_t ret = 0;
585     NetFilterState *nf = NULL;
586 
587     if (direction == NET_FILTER_DIRECTION_TX) {
588         QTAILQ_FOREACH(nf, &nc->filters, next) {
589             ret = qemu_netfilter_receive(nf, direction, sender, flags, iov,
590                                          iovcnt, sent_cb);
591             if (ret) {
592                 return ret;
593             }
594         }
595     } else {
596         QTAILQ_FOREACH_REVERSE(nf, &nc->filters, next) {
597             ret = qemu_netfilter_receive(nf, direction, sender, flags, iov,
598                                          iovcnt, sent_cb);
599             if (ret) {
600                 return ret;
601             }
602         }
603     }
604 
605     return ret;
606 }
607 
608 static ssize_t filter_receive(NetClientState *nc,
609                               NetFilterDirection direction,
610                               NetClientState *sender,
611                               unsigned flags,
612                               const uint8_t *data,
613                               size_t size,
614                               NetPacketSent *sent_cb)
615 {
616     struct iovec iov = {
617         .iov_base = (void *)data,
618         .iov_len = size
619     };
620 
621     return filter_receive_iov(nc, direction, sender, flags, &iov, 1, sent_cb);
622 }
623 
624 void qemu_purge_queued_packets(NetClientState *nc)
625 {
626     if (!nc->peer) {
627         return;
628     }
629 
630     qemu_net_queue_purge(nc->peer->incoming_queue, nc);
631 }
632 
633 void qemu_flush_or_purge_queued_packets(NetClientState *nc, bool purge)
634 {
635     nc->receive_disabled = 0;
636 
637     if (nc->peer && nc->peer->info->type == NET_CLIENT_DRIVER_HUBPORT) {
638         if (net_hub_flush(nc->peer)) {
639             qemu_notify_event();
640         }
641     }
642     if (qemu_net_queue_flush(nc->incoming_queue)) {
643         /* We emptied the queue successfully, signal to the IO thread to repoll
644          * the file descriptor (for tap, for example).
645          */
646         qemu_notify_event();
647     } else if (purge) {
648         /* Unable to empty the queue, purge remaining packets */
649         qemu_net_queue_purge(nc->incoming_queue, nc->peer);
650     }
651 }
652 
653 void qemu_flush_queued_packets(NetClientState *nc)
654 {
655     qemu_flush_or_purge_queued_packets(nc, false);
656 }
657 
658 static ssize_t qemu_send_packet_async_with_flags(NetClientState *sender,
659                                                  unsigned flags,
660                                                  const uint8_t *buf, int size,
661                                                  NetPacketSent *sent_cb)
662 {
663     NetQueue *queue;
664     int ret;
665 
666 #ifdef DEBUG_NET
667     printf("qemu_send_packet_async:\n");
668     qemu_hexdump(stdout, "net", buf, size);
669 #endif
670 
671     if (sender->link_down || !sender->peer) {
672         return size;
673     }
674 
675     /* Let filters handle the packet first */
676     ret = filter_receive(sender, NET_FILTER_DIRECTION_TX,
677                          sender, flags, buf, size, sent_cb);
678     if (ret) {
679         return ret;
680     }
681 
682     ret = filter_receive(sender->peer, NET_FILTER_DIRECTION_RX,
683                          sender, flags, buf, size, sent_cb);
684     if (ret) {
685         return ret;
686     }
687 
688     queue = sender->peer->incoming_queue;
689 
690     return qemu_net_queue_send(queue, sender, flags, buf, size, sent_cb);
691 }
692 
693 ssize_t qemu_send_packet_async(NetClientState *sender,
694                                const uint8_t *buf, int size,
695                                NetPacketSent *sent_cb)
696 {
697     return qemu_send_packet_async_with_flags(sender, QEMU_NET_PACKET_FLAG_NONE,
698                                              buf, size, sent_cb);
699 }
700 
701 ssize_t qemu_send_packet(NetClientState *nc, const uint8_t *buf, int size)
702 {
703     return qemu_send_packet_async(nc, buf, size, NULL);
704 }
705 
706 ssize_t qemu_receive_packet(NetClientState *nc, const uint8_t *buf, int size)
707 {
708     if (!qemu_can_receive_packet(nc)) {
709         return 0;
710     }
711 
712     return qemu_net_queue_receive(nc->incoming_queue, buf, size);
713 }
714 
715 ssize_t qemu_receive_packet_iov(NetClientState *nc, const struct iovec *iov,
716                                 int iovcnt)
717 {
718     if (!qemu_can_receive_packet(nc)) {
719         return 0;
720     }
721 
722     return qemu_net_queue_receive_iov(nc->incoming_queue, iov, iovcnt);
723 }
724 
725 ssize_t qemu_send_packet_raw(NetClientState *nc, const uint8_t *buf, int size)
726 {
727     return qemu_send_packet_async_with_flags(nc, QEMU_NET_PACKET_FLAG_RAW,
728                                              buf, size, NULL);
729 }
730 
731 static ssize_t nc_sendv_compat(NetClientState *nc, const struct iovec *iov,
732                                int iovcnt, unsigned flags)
733 {
734     uint8_t *buf = NULL;
735     uint8_t *buffer;
736     size_t offset;
737     ssize_t ret;
738 
739     if (iovcnt == 1) {
740         buffer = iov[0].iov_base;
741         offset = iov[0].iov_len;
742     } else {
743         offset = iov_size(iov, iovcnt);
744         if (offset > NET_BUFSIZE) {
745             return -1;
746         }
747         buf = g_malloc(offset);
748         buffer = buf;
749         offset = iov_to_buf(iov, iovcnt, 0, buf, offset);
750     }
751 
752     if (flags & QEMU_NET_PACKET_FLAG_RAW && nc->info->receive_raw) {
753         ret = nc->info->receive_raw(nc, buffer, offset);
754     } else {
755         ret = nc->info->receive(nc, buffer, offset);
756     }
757 
758     g_free(buf);
759     return ret;
760 }
761 
762 static ssize_t qemu_deliver_packet_iov(NetClientState *sender,
763                                        unsigned flags,
764                                        const struct iovec *iov,
765                                        int iovcnt,
766                                        void *opaque)
767 {
768     NetClientState *nc = opaque;
769     int ret;
770 
771 
772     if (nc->link_down) {
773         return iov_size(iov, iovcnt);
774     }
775 
776     if (nc->receive_disabled) {
777         return 0;
778     }
779 
780     if (nc->info->receive_iov && !(flags & QEMU_NET_PACKET_FLAG_RAW)) {
781         ret = nc->info->receive_iov(nc, iov, iovcnt);
782     } else {
783         ret = nc_sendv_compat(nc, iov, iovcnt, flags);
784     }
785 
786     if (ret == 0) {
787         nc->receive_disabled = 1;
788     }
789 
790     return ret;
791 }
792 
793 ssize_t qemu_sendv_packet_async(NetClientState *sender,
794                                 const struct iovec *iov, int iovcnt,
795                                 NetPacketSent *sent_cb)
796 {
797     NetQueue *queue;
798     size_t size = iov_size(iov, iovcnt);
799     int ret;
800 
801     if (size > NET_BUFSIZE) {
802         return size;
803     }
804 
805     if (sender->link_down || !sender->peer) {
806         return size;
807     }
808 
809     /* Let filters handle the packet first */
810     ret = filter_receive_iov(sender, NET_FILTER_DIRECTION_TX, sender,
811                              QEMU_NET_PACKET_FLAG_NONE, iov, iovcnt, sent_cb);
812     if (ret) {
813         return ret;
814     }
815 
816     ret = filter_receive_iov(sender->peer, NET_FILTER_DIRECTION_RX, sender,
817                              QEMU_NET_PACKET_FLAG_NONE, iov, iovcnt, sent_cb);
818     if (ret) {
819         return ret;
820     }
821 
822     queue = sender->peer->incoming_queue;
823 
824     return qemu_net_queue_send_iov(queue, sender,
825                                    QEMU_NET_PACKET_FLAG_NONE,
826                                    iov, iovcnt, sent_cb);
827 }
828 
829 ssize_t
830 qemu_sendv_packet(NetClientState *nc, const struct iovec *iov, int iovcnt)
831 {
832     return qemu_sendv_packet_async(nc, iov, iovcnt, NULL);
833 }
834 
835 NetClientState *qemu_find_netdev(const char *id)
836 {
837     NetClientState *nc;
838 
839     QTAILQ_FOREACH(nc, &net_clients, next) {
840         if (nc->info->type == NET_CLIENT_DRIVER_NIC)
841             continue;
842         if (!strcmp(nc->name, id)) {
843             return nc;
844         }
845     }
846 
847     return NULL;
848 }
849 
850 int qemu_find_net_clients_except(const char *id, NetClientState **ncs,
851                                  NetClientDriver type, int max)
852 {
853     NetClientState *nc;
854     int ret = 0;
855 
856     QTAILQ_FOREACH(nc, &net_clients, next) {
857         if (nc->info->type == type) {
858             continue;
859         }
860         if (!id || !strcmp(nc->name, id)) {
861             if (ret < max) {
862                 ncs[ret] = nc;
863             }
864             ret++;
865         }
866     }
867 
868     return ret;
869 }
870 
871 static int nic_get_free_idx(void)
872 {
873     int index;
874 
875     for (index = 0; index < MAX_NICS; index++)
876         if (!nd_table[index].used)
877             return index;
878     return -1;
879 }
880 
881 int qemu_show_nic_models(const char *arg, const char *const *models)
882 {
883     int i;
884 
885     if (!arg || !is_help_option(arg)) {
886         return 0;
887     }
888 
889     printf("Supported NIC models:\n");
890     for (i = 0 ; models[i]; i++) {
891         printf("%s\n", models[i]);
892     }
893     return 1;
894 }
895 
896 void qemu_check_nic_model(NICInfo *nd, const char *model)
897 {
898     const char *models[2];
899 
900     models[0] = model;
901     models[1] = NULL;
902 
903     if (qemu_show_nic_models(nd->model, models))
904         exit(0);
905     if (qemu_find_nic_model(nd, models, model) < 0)
906         exit(1);
907 }
908 
909 int qemu_find_nic_model(NICInfo *nd, const char * const *models,
910                         const char *default_model)
911 {
912     int i;
913 
914     if (!nd->model)
915         nd->model = g_strdup(default_model);
916 
917     for (i = 0 ; models[i]; i++) {
918         if (strcmp(nd->model, models[i]) == 0)
919             return i;
920     }
921 
922     error_report("Unsupported NIC model: %s", nd->model);
923     return -1;
924 }
925 
926 static int net_init_nic(const Netdev *netdev, const char *name,
927                         NetClientState *peer, Error **errp)
928 {
929     int idx;
930     NICInfo *nd;
931     const NetLegacyNicOptions *nic;
932 
933     assert(netdev->type == NET_CLIENT_DRIVER_NIC);
934     nic = &netdev->u.nic;
935 
936     idx = nic_get_free_idx();
937     if (idx == -1 || nb_nics >= MAX_NICS) {
938         error_setg(errp, "too many NICs");
939         return -1;
940     }
941 
942     nd = &nd_table[idx];
943 
944     memset(nd, 0, sizeof(*nd));
945 
946     if (nic->has_netdev) {
947         nd->netdev = qemu_find_netdev(nic->netdev);
948         if (!nd->netdev) {
949             error_setg(errp, "netdev '%s' not found", nic->netdev);
950             return -1;
951         }
952     } else {
953         assert(peer);
954         nd->netdev = peer;
955     }
956     nd->name = g_strdup(name);
957     if (nic->has_model) {
958         nd->model = g_strdup(nic->model);
959     }
960     if (nic->has_addr) {
961         nd->devaddr = g_strdup(nic->addr);
962     }
963 
964     if (nic->has_macaddr &&
965         net_parse_macaddr(nd->macaddr.a, nic->macaddr) < 0) {
966         error_setg(errp, "invalid syntax for ethernet address");
967         return -1;
968     }
969     if (nic->has_macaddr &&
970         is_multicast_ether_addr(nd->macaddr.a)) {
971         error_setg(errp,
972                    "NIC cannot have multicast MAC address (odd 1st byte)");
973         return -1;
974     }
975     qemu_macaddr_default_if_unset(&nd->macaddr);
976 
977     if (nic->has_vectors) {
978         if (nic->vectors > 0x7ffffff) {
979             error_setg(errp, "invalid # of vectors: %"PRIu32, nic->vectors);
980             return -1;
981         }
982         nd->nvectors = nic->vectors;
983     } else {
984         nd->nvectors = DEV_NVECTORS_UNSPECIFIED;
985     }
986 
987     nd->used = 1;
988     nb_nics++;
989 
990     return idx;
991 }
992 
993 
994 static int (* const net_client_init_fun[NET_CLIENT_DRIVER__MAX])(
995     const Netdev *netdev,
996     const char *name,
997     NetClientState *peer, Error **errp) = {
998         [NET_CLIENT_DRIVER_NIC]       = net_init_nic,
999 #ifdef CONFIG_SLIRP
1000         [NET_CLIENT_DRIVER_USER]      = net_init_slirp,
1001 #endif
1002         [NET_CLIENT_DRIVER_TAP]       = net_init_tap,
1003         [NET_CLIENT_DRIVER_SOCKET]    = net_init_socket,
1004 #ifdef CONFIG_VDE
1005         [NET_CLIENT_DRIVER_VDE]       = net_init_vde,
1006 #endif
1007 #ifdef CONFIG_NETMAP
1008         [NET_CLIENT_DRIVER_NETMAP]    = net_init_netmap,
1009 #endif
1010 #ifdef CONFIG_NET_BRIDGE
1011         [NET_CLIENT_DRIVER_BRIDGE]    = net_init_bridge,
1012 #endif
1013         [NET_CLIENT_DRIVER_HUBPORT]   = net_init_hubport,
1014 #ifdef CONFIG_VHOST_NET_USER
1015         [NET_CLIENT_DRIVER_VHOST_USER] = net_init_vhost_user,
1016 #endif
1017 #ifdef CONFIG_VHOST_NET_VDPA
1018         [NET_CLIENT_DRIVER_VHOST_VDPA] = net_init_vhost_vdpa,
1019 #endif
1020 #ifdef CONFIG_L2TPV3
1021         [NET_CLIENT_DRIVER_L2TPV3]    = net_init_l2tpv3,
1022 #endif
1023 #ifdef CONFIG_VMNET
1024         [NET_CLIENT_DRIVER_VMNET_HOST] = net_init_vmnet_host,
1025         [NET_CLIENT_DRIVER_VMNET_SHARED] = net_init_vmnet_shared,
1026         [NET_CLIENT_DRIVER_VMNET_BRIDGED] = net_init_vmnet_bridged,
1027 #endif /* CONFIG_VMNET */
1028 };
1029 
1030 
1031 static int net_client_init1(const Netdev *netdev, bool is_netdev, Error **errp)
1032 {
1033     NetClientState *peer = NULL;
1034     NetClientState *nc;
1035 
1036     if (is_netdev) {
1037         if (netdev->type == NET_CLIENT_DRIVER_NIC ||
1038             !net_client_init_fun[netdev->type]) {
1039             error_setg(errp, QERR_INVALID_PARAMETER_VALUE, "type",
1040                        "a netdev backend type");
1041             return -1;
1042         }
1043     } else {
1044         if (netdev->type == NET_CLIENT_DRIVER_NONE) {
1045             return 0; /* nothing to do */
1046         }
1047         if (netdev->type == NET_CLIENT_DRIVER_HUBPORT ||
1048             !net_client_init_fun[netdev->type]) {
1049             error_setg(errp, QERR_INVALID_PARAMETER_VALUE, "type",
1050                        "a net backend type (maybe it is not compiled "
1051                        "into this binary)");
1052             return -1;
1053         }
1054 
1055         /* Do not add to a hub if it's a nic with a netdev= parameter. */
1056         if (netdev->type != NET_CLIENT_DRIVER_NIC ||
1057             !netdev->u.nic.has_netdev) {
1058             peer = net_hub_add_port(0, NULL, NULL);
1059         }
1060     }
1061 
1062     nc = qemu_find_netdev(netdev->id);
1063     if (nc) {
1064         error_setg(errp, "Duplicate ID '%s'", netdev->id);
1065         return -1;
1066     }
1067 
1068     if (net_client_init_fun[netdev->type](netdev, netdev->id, peer, errp) < 0) {
1069         /* FIXME drop when all init functions store an Error */
1070         if (errp && !*errp) {
1071             error_setg(errp, "Device '%s' could not be initialized",
1072                        NetClientDriver_str(netdev->type));
1073         }
1074         return -1;
1075     }
1076 
1077     if (is_netdev) {
1078         nc = qemu_find_netdev(netdev->id);
1079         assert(nc);
1080         nc->is_netdev = true;
1081     }
1082 
1083     return 0;
1084 }
1085 
1086 void show_netdevs(void)
1087 {
1088     int idx;
1089     const char *available_netdevs[] = {
1090         "socket",
1091         "hubport",
1092         "tap",
1093 #ifdef CONFIG_SLIRP
1094         "user",
1095 #endif
1096 #ifdef CONFIG_L2TPV3
1097         "l2tpv3",
1098 #endif
1099 #ifdef CONFIG_VDE
1100         "vde",
1101 #endif
1102 #ifdef CONFIG_NET_BRIDGE
1103         "bridge",
1104 #endif
1105 #ifdef CONFIG_NETMAP
1106         "netmap",
1107 #endif
1108 #ifdef CONFIG_POSIX
1109         "vhost-user",
1110 #endif
1111 #ifdef CONFIG_VHOST_VDPA
1112         "vhost-vdpa",
1113 #endif
1114 #ifdef CONFIG_VMNET
1115         "vmnet-host",
1116         "vmnet-shared",
1117         "vmnet-bridged",
1118 #endif
1119     };
1120 
1121     qemu_printf("Available netdev backend types:\n");
1122     for (idx = 0; idx < ARRAY_SIZE(available_netdevs); idx++) {
1123         qemu_printf("%s\n", available_netdevs[idx]);
1124     }
1125 }
1126 
1127 static int net_client_init(QemuOpts *opts, bool is_netdev, Error **errp)
1128 {
1129     gchar **substrings = NULL;
1130     Netdev *object = NULL;
1131     int ret = -1;
1132     Visitor *v = opts_visitor_new(opts);
1133 
1134     /* Parse convenience option format ip6-net=fec0::0[/64] */
1135     const char *ip6_net = qemu_opt_get(opts, "ipv6-net");
1136 
1137     if (ip6_net) {
1138         char *prefix_addr;
1139         unsigned long prefix_len = 64; /* Default 64bit prefix length. */
1140 
1141         substrings = g_strsplit(ip6_net, "/", 2);
1142         if (!substrings || !substrings[0]) {
1143             error_setg(errp, QERR_INVALID_PARAMETER_VALUE, "ipv6-net",
1144                        "a valid IPv6 prefix");
1145             goto out;
1146         }
1147 
1148         prefix_addr = substrings[0];
1149 
1150         /* Handle user-specified prefix length. */
1151         if (substrings[1] &&
1152             qemu_strtoul(substrings[1], NULL, 10, &prefix_len))
1153         {
1154             error_setg(errp, QERR_INVALID_PARAMETER_VALUE,
1155                        "ipv6-prefixlen", "a number");
1156             goto out;
1157         }
1158 
1159         qemu_opt_set(opts, "ipv6-prefix", prefix_addr, &error_abort);
1160         qemu_opt_set_number(opts, "ipv6-prefixlen", prefix_len,
1161                             &error_abort);
1162         qemu_opt_unset(opts, "ipv6-net");
1163     }
1164 
1165     /* Create an ID for -net if the user did not specify one */
1166     if (!is_netdev && !qemu_opts_id(opts)) {
1167         qemu_opts_set_id(opts, id_generate(ID_NET));
1168     }
1169 
1170     if (visit_type_Netdev(v, NULL, &object, errp)) {
1171         ret = net_client_init1(object, is_netdev, errp);
1172     }
1173 
1174     qapi_free_Netdev(object);
1175 
1176 out:
1177     g_strfreev(substrings);
1178     visit_free(v);
1179     return ret;
1180 }
1181 
1182 void netdev_add(QemuOpts *opts, Error **errp)
1183 {
1184     net_client_init(opts, true, errp);
1185 }
1186 
1187 void qmp_netdev_add(Netdev *netdev, Error **errp)
1188 {
1189     if (!id_wellformed(netdev->id)) {
1190         error_setg(errp, QERR_INVALID_PARAMETER_VALUE, "id", "an identifier");
1191         return;
1192     }
1193 
1194     net_client_init1(netdev, true, errp);
1195 }
1196 
1197 void qmp_netdev_del(const char *id, Error **errp)
1198 {
1199     NetClientState *nc;
1200     QemuOpts *opts;
1201 
1202     nc = qemu_find_netdev(id);
1203     if (!nc) {
1204         error_set(errp, ERROR_CLASS_DEVICE_NOT_FOUND,
1205                   "Device '%s' not found", id);
1206         return;
1207     }
1208 
1209     if (!nc->is_netdev) {
1210         error_setg(errp, "Device '%s' is not a netdev", id);
1211         return;
1212     }
1213 
1214     qemu_del_net_client(nc);
1215 
1216     /*
1217      * Wart: we need to delete the QemuOpts associated with netdevs
1218      * created via CLI or HMP, to avoid bogus "Duplicate ID" errors in
1219      * HMP netdev_add.
1220      */
1221     opts = qemu_opts_find(qemu_find_opts("netdev"), id);
1222     if (opts) {
1223         qemu_opts_del(opts);
1224     }
1225 }
1226 
1227 static void netfilter_print_info(Monitor *mon, NetFilterState *nf)
1228 {
1229     char *str;
1230     ObjectProperty *prop;
1231     ObjectPropertyIterator iter;
1232     Visitor *v;
1233 
1234     /* generate info str */
1235     object_property_iter_init(&iter, OBJECT(nf));
1236     while ((prop = object_property_iter_next(&iter))) {
1237         if (!strcmp(prop->name, "type")) {
1238             continue;
1239         }
1240         v = string_output_visitor_new(false, &str);
1241         object_property_get(OBJECT(nf), prop->name, v, NULL);
1242         visit_complete(v, &str);
1243         visit_free(v);
1244         monitor_printf(mon, ",%s=%s", prop->name, str);
1245         g_free(str);
1246     }
1247     monitor_printf(mon, "\n");
1248 }
1249 
1250 void print_net_client(Monitor *mon, NetClientState *nc)
1251 {
1252     NetFilterState *nf;
1253 
1254     monitor_printf(mon, "%s: index=%d,type=%s,%s\n", nc->name,
1255                    nc->queue_index,
1256                    NetClientDriver_str(nc->info->type),
1257                    nc->info_str);
1258     if (!QTAILQ_EMPTY(&nc->filters)) {
1259         monitor_printf(mon, "filters:\n");
1260     }
1261     QTAILQ_FOREACH(nf, &nc->filters, next) {
1262         monitor_printf(mon, "  - %s: type=%s",
1263                        object_get_canonical_path_component(OBJECT(nf)),
1264                        object_get_typename(OBJECT(nf)));
1265         netfilter_print_info(mon, nf);
1266     }
1267 }
1268 
1269 RxFilterInfoList *qmp_query_rx_filter(bool has_name, const char *name,
1270                                       Error **errp)
1271 {
1272     NetClientState *nc;
1273     RxFilterInfoList *filter_list = NULL, **tail = &filter_list;
1274 
1275     QTAILQ_FOREACH(nc, &net_clients, next) {
1276         RxFilterInfo *info;
1277 
1278         if (has_name && strcmp(nc->name, name) != 0) {
1279             continue;
1280         }
1281 
1282         /* only query rx-filter information of NIC */
1283         if (nc->info->type != NET_CLIENT_DRIVER_NIC) {
1284             if (has_name) {
1285                 error_setg(errp, "net client(%s) isn't a NIC", name);
1286                 assert(!filter_list);
1287                 return NULL;
1288             }
1289             continue;
1290         }
1291 
1292         /* only query information on queue 0 since the info is per nic,
1293          * not per queue
1294          */
1295         if (nc->queue_index != 0)
1296             continue;
1297 
1298         if (nc->info->query_rx_filter) {
1299             info = nc->info->query_rx_filter(nc);
1300             QAPI_LIST_APPEND(tail, info);
1301         } else if (has_name) {
1302             error_setg(errp, "net client(%s) doesn't support"
1303                        " rx-filter querying", name);
1304             assert(!filter_list);
1305             return NULL;
1306         }
1307 
1308         if (has_name) {
1309             break;
1310         }
1311     }
1312 
1313     if (filter_list == NULL && has_name) {
1314         error_setg(errp, "invalid net client name: %s", name);
1315     }
1316 
1317     return filter_list;
1318 }
1319 
1320 void hmp_info_network(Monitor *mon, const QDict *qdict)
1321 {
1322     NetClientState *nc, *peer;
1323     NetClientDriver type;
1324 
1325     net_hub_info(mon);
1326 
1327     QTAILQ_FOREACH(nc, &net_clients, next) {
1328         peer = nc->peer;
1329         type = nc->info->type;
1330 
1331         /* Skip if already printed in hub info */
1332         if (net_hub_id_for_client(nc, NULL) == 0) {
1333             continue;
1334         }
1335 
1336         if (!peer || type == NET_CLIENT_DRIVER_NIC) {
1337             print_net_client(mon, nc);
1338         } /* else it's a netdev connected to a NIC, printed with the NIC */
1339         if (peer && type == NET_CLIENT_DRIVER_NIC) {
1340             monitor_printf(mon, " \\ ");
1341             print_net_client(mon, peer);
1342         }
1343     }
1344 }
1345 
1346 void colo_notify_filters_event(int event, Error **errp)
1347 {
1348     NetClientState *nc;
1349     NetFilterState *nf;
1350     NetFilterClass *nfc = NULL;
1351     Error *local_err = NULL;
1352 
1353     QTAILQ_FOREACH(nc, &net_clients, next) {
1354         QTAILQ_FOREACH(nf, &nc->filters, next) {
1355             nfc = NETFILTER_GET_CLASS(OBJECT(nf));
1356             nfc->handle_event(nf, event, &local_err);
1357             if (local_err) {
1358                 error_propagate(errp, local_err);
1359                 return;
1360             }
1361         }
1362     }
1363 }
1364 
1365 void qmp_set_link(const char *name, bool up, Error **errp)
1366 {
1367     NetClientState *ncs[MAX_QUEUE_NUM];
1368     NetClientState *nc;
1369     int queues, i;
1370 
1371     queues = qemu_find_net_clients_except(name, ncs,
1372                                           NET_CLIENT_DRIVER__MAX,
1373                                           MAX_QUEUE_NUM);
1374 
1375     if (queues == 0) {
1376         error_set(errp, ERROR_CLASS_DEVICE_NOT_FOUND,
1377                   "Device '%s' not found", name);
1378         return;
1379     }
1380     nc = ncs[0];
1381 
1382     for (i = 0; i < queues; i++) {
1383         ncs[i]->link_down = !up;
1384     }
1385 
1386     if (nc->info->link_status_changed) {
1387         nc->info->link_status_changed(nc);
1388     }
1389 
1390     if (nc->peer) {
1391         /* Change peer link only if the peer is NIC and then notify peer.
1392          * If the peer is a HUBPORT or a backend, we do not change the
1393          * link status.
1394          *
1395          * This behavior is compatible with qemu hubs where there could be
1396          * multiple clients that can still communicate with each other in
1397          * disconnected mode. For now maintain this compatibility.
1398          */
1399         if (nc->peer->info->type == NET_CLIENT_DRIVER_NIC) {
1400             for (i = 0; i < queues; i++) {
1401                 ncs[i]->peer->link_down = !up;
1402             }
1403         }
1404         if (nc->peer->info->link_status_changed) {
1405             nc->peer->info->link_status_changed(nc->peer);
1406         }
1407     }
1408 }
1409 
1410 static void net_vm_change_state_handler(void *opaque, bool running,
1411                                         RunState state)
1412 {
1413     NetClientState *nc;
1414     NetClientState *tmp;
1415 
1416     QTAILQ_FOREACH_SAFE(nc, &net_clients, next, tmp) {
1417         if (running) {
1418             /* Flush queued packets and wake up backends. */
1419             if (nc->peer && qemu_can_send_packet(nc)) {
1420                 qemu_flush_queued_packets(nc->peer);
1421             }
1422         } else {
1423             /* Complete all queued packets, to guarantee we don't modify
1424              * state later when VM is not running.
1425              */
1426             qemu_flush_or_purge_queued_packets(nc, true);
1427         }
1428     }
1429 }
1430 
1431 void net_cleanup(void)
1432 {
1433     NetClientState *nc;
1434 
1435     /*cleanup colo compare module for COLO*/
1436     colo_compare_cleanup();
1437 
1438     /* We may del multiple entries during qemu_del_net_client(),
1439      * so QTAILQ_FOREACH_SAFE() is also not safe here.
1440      */
1441     while (!QTAILQ_EMPTY(&net_clients)) {
1442         nc = QTAILQ_FIRST(&net_clients);
1443         if (nc->info->type == NET_CLIENT_DRIVER_NIC) {
1444             qemu_del_nic(qemu_get_nic(nc));
1445         } else {
1446             qemu_del_net_client(nc);
1447         }
1448     }
1449 
1450     qemu_del_vm_change_state_handler(net_change_state_entry);
1451 }
1452 
1453 void net_check_clients(void)
1454 {
1455     NetClientState *nc;
1456     int i;
1457 
1458     net_hub_check_clients();
1459 
1460     QTAILQ_FOREACH(nc, &net_clients, next) {
1461         if (!nc->peer) {
1462             warn_report("%s %s has no peer",
1463                         nc->info->type == NET_CLIENT_DRIVER_NIC
1464                         ? "nic" : "netdev",
1465                         nc->name);
1466         }
1467     }
1468 
1469     /* Check that all NICs requested via -net nic actually got created.
1470      * NICs created via -device don't need to be checked here because
1471      * they are always instantiated.
1472      */
1473     for (i = 0; i < MAX_NICS; i++) {
1474         NICInfo *nd = &nd_table[i];
1475         if (nd->used && !nd->instantiated) {
1476             warn_report("requested NIC (%s, model %s) "
1477                         "was not created (not supported by this machine?)",
1478                         nd->name ? nd->name : "anonymous",
1479                         nd->model ? nd->model : "unspecified");
1480         }
1481     }
1482 }
1483 
1484 static int net_init_client(void *dummy, QemuOpts *opts, Error **errp)
1485 {
1486     return net_client_init(opts, false, errp);
1487 }
1488 
1489 static int net_init_netdev(void *dummy, QemuOpts *opts, Error **errp)
1490 {
1491     const char *type = qemu_opt_get(opts, "type");
1492 
1493     if (type && is_help_option(type)) {
1494         show_netdevs();
1495         exit(0);
1496     }
1497     return net_client_init(opts, true, errp);
1498 }
1499 
1500 /* For the convenience "--nic" parameter */
1501 static int net_param_nic(void *dummy, QemuOpts *opts, Error **errp)
1502 {
1503     char *mac, *nd_id;
1504     int idx, ret;
1505     NICInfo *ni;
1506     const char *type;
1507 
1508     type = qemu_opt_get(opts, "type");
1509     if (type && g_str_equal(type, "none")) {
1510         return 0;    /* Nothing to do, default_net is cleared in vl.c */
1511     }
1512 
1513     idx = nic_get_free_idx();
1514     if (idx == -1 || nb_nics >= MAX_NICS) {
1515         error_setg(errp, "no more on-board/default NIC slots available");
1516         return -1;
1517     }
1518 
1519     if (!type) {
1520         qemu_opt_set(opts, "type", "user", &error_abort);
1521     }
1522 
1523     ni = &nd_table[idx];
1524     memset(ni, 0, sizeof(*ni));
1525     ni->model = qemu_opt_get_del(opts, "model");
1526 
1527     /* Create an ID if the user did not specify one */
1528     nd_id = g_strdup(qemu_opts_id(opts));
1529     if (!nd_id) {
1530         nd_id = id_generate(ID_NET);
1531         qemu_opts_set_id(opts, nd_id);
1532     }
1533 
1534     /* Handle MAC address */
1535     mac = qemu_opt_get_del(opts, "mac");
1536     if (mac) {
1537         ret = net_parse_macaddr(ni->macaddr.a, mac);
1538         g_free(mac);
1539         if (ret) {
1540             error_setg(errp, "invalid syntax for ethernet address");
1541             goto out;
1542         }
1543         if (is_multicast_ether_addr(ni->macaddr.a)) {
1544             error_setg(errp, "NIC cannot have multicast MAC address");
1545             ret = -1;
1546             goto out;
1547         }
1548     }
1549     qemu_macaddr_default_if_unset(&ni->macaddr);
1550 
1551     ret = net_client_init(opts, true, errp);
1552     if (ret == 0) {
1553         ni->netdev = qemu_find_netdev(nd_id);
1554         ni->used = true;
1555         nb_nics++;
1556     }
1557 
1558 out:
1559     g_free(nd_id);
1560     return ret;
1561 }
1562 
1563 int net_init_clients(Error **errp)
1564 {
1565     net_change_state_entry =
1566         qemu_add_vm_change_state_handler(net_vm_change_state_handler, NULL);
1567 
1568     QTAILQ_INIT(&net_clients);
1569 
1570     if (qemu_opts_foreach(qemu_find_opts("netdev"),
1571                           net_init_netdev, NULL, errp)) {
1572         return -1;
1573     }
1574 
1575     if (qemu_opts_foreach(qemu_find_opts("nic"), net_param_nic, NULL, errp)) {
1576         return -1;
1577     }
1578 
1579     if (qemu_opts_foreach(qemu_find_opts("net"), net_init_client, NULL, errp)) {
1580         return -1;
1581     }
1582 
1583     return 0;
1584 }
1585 
1586 int net_client_parse(QemuOptsList *opts_list, const char *optarg)
1587 {
1588     if (!qemu_opts_parse_noisily(opts_list, optarg, true)) {
1589         return -1;
1590     }
1591 
1592     return 0;
1593 }
1594 
1595 /* From FreeBSD */
1596 /* XXX: optimize */
1597 uint32_t net_crc32(const uint8_t *p, int len)
1598 {
1599     uint32_t crc;
1600     int carry, i, j;
1601     uint8_t b;
1602 
1603     crc = 0xffffffff;
1604     for (i = 0; i < len; i++) {
1605         b = *p++;
1606         for (j = 0; j < 8; j++) {
1607             carry = ((crc & 0x80000000L) ? 1 : 0) ^ (b & 0x01);
1608             crc <<= 1;
1609             b >>= 1;
1610             if (carry) {
1611                 crc = ((crc ^ POLYNOMIAL_BE) | carry);
1612             }
1613         }
1614     }
1615 
1616     return crc;
1617 }
1618 
1619 uint32_t net_crc32_le(const uint8_t *p, int len)
1620 {
1621     uint32_t crc;
1622     int carry, i, j;
1623     uint8_t b;
1624 
1625     crc = 0xffffffff;
1626     for (i = 0; i < len; i++) {
1627         b = *p++;
1628         for (j = 0; j < 8; j++) {
1629             carry = (crc & 0x1) ^ (b & 0x01);
1630             crc >>= 1;
1631             b >>= 1;
1632             if (carry) {
1633                 crc ^= POLYNOMIAL_LE;
1634             }
1635         }
1636     }
1637 
1638     return crc;
1639 }
1640 
1641 QemuOptsList qemu_netdev_opts = {
1642     .name = "netdev",
1643     .implied_opt_name = "type",
1644     .head = QTAILQ_HEAD_INITIALIZER(qemu_netdev_opts.head),
1645     .desc = {
1646         /*
1647          * no elements => accept any params
1648          * validation will happen later
1649          */
1650         { /* end of list */ }
1651     },
1652 };
1653 
1654 QemuOptsList qemu_nic_opts = {
1655     .name = "nic",
1656     .implied_opt_name = "type",
1657     .head = QTAILQ_HEAD_INITIALIZER(qemu_nic_opts.head),
1658     .desc = {
1659         /*
1660          * no elements => accept any params
1661          * validation will happen later
1662          */
1663         { /* end of list */ }
1664     },
1665 };
1666 
1667 QemuOptsList qemu_net_opts = {
1668     .name = "net",
1669     .implied_opt_name = "type",
1670     .head = QTAILQ_HEAD_INITIALIZER(qemu_net_opts.head),
1671     .desc = {
1672         /*
1673          * no elements => accept any params
1674          * validation will happen later
1675          */
1676         { /* end of list */ }
1677     },
1678 };
1679 
1680 void net_socket_rs_init(SocketReadState *rs,
1681                         SocketReadStateFinalize *finalize,
1682                         bool vnet_hdr)
1683 {
1684     rs->state = 0;
1685     rs->vnet_hdr = vnet_hdr;
1686     rs->index = 0;
1687     rs->packet_len = 0;
1688     rs->vnet_hdr_len = 0;
1689     memset(rs->buf, 0, sizeof(rs->buf));
1690     rs->finalize = finalize;
1691 }
1692 
1693 /*
1694  * Returns
1695  * 0: success
1696  * -1: error occurs
1697  */
1698 int net_fill_rstate(SocketReadState *rs, const uint8_t *buf, int size)
1699 {
1700     unsigned int l;
1701 
1702     while (size > 0) {
1703         /* Reassemble a packet from the network.
1704          * 0 = getting length.
1705          * 1 = getting vnet header length.
1706          * 2 = getting data.
1707          */
1708         switch (rs->state) {
1709         case 0:
1710             l = 4 - rs->index;
1711             if (l > size) {
1712                 l = size;
1713             }
1714             memcpy(rs->buf + rs->index, buf, l);
1715             buf += l;
1716             size -= l;
1717             rs->index += l;
1718             if (rs->index == 4) {
1719                 /* got length */
1720                 rs->packet_len = ntohl(*(uint32_t *)rs->buf);
1721                 rs->index = 0;
1722                 if (rs->vnet_hdr) {
1723                     rs->state = 1;
1724                 } else {
1725                     rs->state = 2;
1726                     rs->vnet_hdr_len = 0;
1727                 }
1728             }
1729             break;
1730         case 1:
1731             l = 4 - rs->index;
1732             if (l > size) {
1733                 l = size;
1734             }
1735             memcpy(rs->buf + rs->index, buf, l);
1736             buf += l;
1737             size -= l;
1738             rs->index += l;
1739             if (rs->index == 4) {
1740                 /* got vnet header length */
1741                 rs->vnet_hdr_len = ntohl(*(uint32_t *)rs->buf);
1742                 rs->index = 0;
1743                 rs->state = 2;
1744             }
1745             break;
1746         case 2:
1747             l = rs->packet_len - rs->index;
1748             if (l > size) {
1749                 l = size;
1750             }
1751             if (rs->index + l <= sizeof(rs->buf)) {
1752                 memcpy(rs->buf + rs->index, buf, l);
1753             } else {
1754                 fprintf(stderr, "serious error: oversized packet received,"
1755                     "connection terminated.\n");
1756                 rs->index = rs->state = 0;
1757                 return -1;
1758             }
1759 
1760             rs->index += l;
1761             buf += l;
1762             size -= l;
1763             if (rs->index >= rs->packet_len) {
1764                 rs->index = 0;
1765                 rs->state = 0;
1766                 assert(rs->finalize);
1767                 rs->finalize(rs);
1768             }
1769             break;
1770         }
1771     }
1772 
1773     assert(size == 0);
1774     return 0;
1775 }
1776