xref: /openbmc/qemu/net/net.c (revision ff81439a)
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 #include "qemu-common.h"
27 
28 #include "net/net.h"
29 #include "clients.h"
30 #include "hub.h"
31 #include "hw/qdev-properties.h"
32 #include "net/slirp.h"
33 #include "net/eth.h"
34 #include "util.h"
35 
36 #include "monitor/monitor.h"
37 #include "qemu/help_option.h"
38 #include "qapi/qapi-commands-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/sysemu.h"
54 #include "sysemu/runstate.h"
55 #include "sysemu/sysemu.h"
56 #include "net/filter.h"
57 #include "qapi/string-output-visitor.h"
58 #include "qapi/hmp-output-visitor.h"
59 
60 /* Net bridge is currently not supported for W32. */
61 #if !defined(_WIN32)
62 # define CONFIG_NET_BRIDGE
63 #endif
64 
65 static VMChangeStateEntry *net_change_state_entry;
66 static QTAILQ_HEAD(, NetClientState) net_clients;
67 
68 /***********************************************************/
69 /* network device redirectors */
70 
71 int parse_host_port(struct sockaddr_in *saddr, const char *str,
72                     Error **errp)
73 {
74     gchar **substrings;
75     struct hostent *he;
76     const char *addr, *p, *r;
77     int port, ret = 0;
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     g_free(nc->info_str);
134     nc->info_str = g_strdup_printf(
135         "model=%s,macaddr=%02x:%02x:%02x:%02x:%02x:%02x",
136         nc->model,
137         macaddr[0], macaddr[1], macaddr[2],
138         macaddr[3], macaddr[4], macaddr[5]);
139 }
140 
141 static int mac_table[256] = {0};
142 
143 static void qemu_macaddr_set_used(MACAddr *macaddr)
144 {
145     int index;
146 
147     for (index = 0x56; index < 0xFF; index++) {
148         if (macaddr->a[5] == index) {
149             mac_table[index]++;
150         }
151     }
152 }
153 
154 static void qemu_macaddr_set_free(MACAddr *macaddr)
155 {
156     int index;
157     static const MACAddr base = { .a = { 0x52, 0x54, 0x00, 0x12, 0x34, 0 } };
158 
159     if (memcmp(macaddr->a, &base.a, (sizeof(base.a) - 1)) != 0) {
160         return;
161     }
162     for (index = 0x56; index < 0xFF; index++) {
163         if (macaddr->a[5] == index) {
164             mac_table[index]--;
165         }
166     }
167 }
168 
169 static int qemu_macaddr_get_free(void)
170 {
171     int index;
172 
173     for (index = 0x56; index < 0xFF; index++) {
174         if (mac_table[index] == 0) {
175             return index;
176         }
177     }
178 
179     return -1;
180 }
181 
182 void qemu_macaddr_default_if_unset(MACAddr *macaddr)
183 {
184     static const MACAddr zero = { .a = { 0,0,0,0,0,0 } };
185     static const MACAddr base = { .a = { 0x52, 0x54, 0x00, 0x12, 0x34, 0 } };
186 
187     if (memcmp(macaddr, &zero, sizeof(zero)) != 0) {
188         if (memcmp(macaddr->a, &base.a, (sizeof(base.a) - 1)) != 0) {
189             return;
190         } else {
191             qemu_macaddr_set_used(macaddr);
192             return;
193         }
194     }
195 
196     macaddr->a[0] = 0x52;
197     macaddr->a[1] = 0x54;
198     macaddr->a[2] = 0x00;
199     macaddr->a[3] = 0x12;
200     macaddr->a[4] = 0x34;
201     macaddr->a[5] = qemu_macaddr_get_free();
202     qemu_macaddr_set_used(macaddr);
203 }
204 
205 /**
206  * Generate a name for net client
207  *
208  * Only net clients created with the legacy -net option and NICs need this.
209  */
210 static char *assign_name(NetClientState *nc1, const char *model)
211 {
212     NetClientState *nc;
213     int id = 0;
214 
215     QTAILQ_FOREACH(nc, &net_clients, next) {
216         if (nc == nc1) {
217             continue;
218         }
219         if (strcmp(nc->model, model) == 0) {
220             id++;
221         }
222     }
223 
224     return g_strdup_printf("%s.%d", model, id);
225 }
226 
227 static void qemu_net_client_destructor(NetClientState *nc)
228 {
229     g_free(nc);
230 }
231 static ssize_t qemu_deliver_packet_iov(NetClientState *sender,
232                                        unsigned flags,
233                                        const struct iovec *iov,
234                                        int iovcnt,
235                                        void *opaque);
236 
237 static void qemu_net_client_setup(NetClientState *nc,
238                                   NetClientInfo *info,
239                                   NetClientState *peer,
240                                   const char *model,
241                                   const char *name,
242                                   NetClientDestructor *destructor)
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     QTAILQ_INIT(&nc->filters);
262 }
263 
264 NetClientState *qemu_new_net_client(NetClientInfo *info,
265                                     NetClientState *peer,
266                                     const char *model,
267                                     const char *name)
268 {
269     NetClientState *nc;
270 
271     assert(info->size >= sizeof(NetClientState));
272 
273     nc = g_malloc0(info->size);
274     qemu_net_client_setup(nc, info, peer, model, name,
275                           qemu_net_client_destructor);
276 
277     return nc;
278 }
279 
280 NICState *qemu_new_nic(NetClientInfo *info,
281                        NICConf *conf,
282                        const char *model,
283                        const char *name,
284                        void *opaque)
285 {
286     NetClientState **peers = conf->peers.ncs;
287     NICState *nic;
288     int i, queues = MAX(1, conf->peers.queues);
289 
290     assert(info->type == NET_CLIENT_DRIVER_NIC);
291     assert(info->size >= sizeof(NICState));
292 
293     nic = g_malloc0(info->size + sizeof(NetClientState) * queues);
294     nic->ncs = (void *)nic + info->size;
295     nic->conf = conf;
296     nic->opaque = opaque;
297 
298     for (i = 0; i < queues; i++) {
299         qemu_net_client_setup(&nic->ncs[i], info, peers[i], model, name,
300                               NULL);
301         nic->ncs[i].queue_index = i;
302     }
303 
304     return nic;
305 }
306 
307 NetClientState *qemu_get_subqueue(NICState *nic, int queue_index)
308 {
309     return nic->ncs + queue_index;
310 }
311 
312 NetClientState *qemu_get_queue(NICState *nic)
313 {
314     return qemu_get_subqueue(nic, 0);
315 }
316 
317 NICState *qemu_get_nic(NetClientState *nc)
318 {
319     NetClientState *nc0 = nc - nc->queue_index;
320 
321     return (NICState *)((void *)nc0 - nc->info->size);
322 }
323 
324 void *qemu_get_nic_opaque(NetClientState *nc)
325 {
326     NICState *nic = qemu_get_nic(nc);
327 
328     return nic->opaque;
329 }
330 
331 NetClientState *qemu_get_peer(NetClientState *nc, int queue_index)
332 {
333     assert(nc != NULL);
334     NetClientState *ncs = nc + queue_index;
335     return ncs->peer;
336 }
337 
338 static void qemu_cleanup_net_client(NetClientState *nc)
339 {
340     QTAILQ_REMOVE(&net_clients, nc, next);
341 
342     if (nc->info->cleanup) {
343         nc->info->cleanup(nc);
344     }
345 }
346 
347 static void qemu_free_net_client(NetClientState *nc)
348 {
349     if (nc->incoming_queue) {
350         qemu_del_net_queue(nc->incoming_queue);
351     }
352     if (nc->peer) {
353         nc->peer->peer = NULL;
354     }
355     g_free(nc->name);
356     g_free(nc->model);
357     g_free(nc->info_str);
358     qapi_free_NetdevInfo(nc->stored_config);
359     if (nc->destructor) {
360         nc->destructor(nc);
361     }
362 }
363 
364 void qemu_del_net_client(NetClientState *nc)
365 {
366     NetClientState *ncs[MAX_QUEUE_NUM];
367     int queues, i;
368     NetFilterState *nf, *next;
369 
370     assert(nc->info->type != NET_CLIENT_DRIVER_NIC);
371 
372     /* If the NetClientState belongs to a multiqueue backend, we will change all
373      * other NetClientStates also.
374      */
375     queues = qemu_find_net_clients_except(nc->name, ncs,
376                                           NET_CLIENT_DRIVER_NIC,
377                                           MAX_QUEUE_NUM);
378     assert(queues != 0);
379 
380     QTAILQ_FOREACH_SAFE(nf, &nc->filters, next, next) {
381         object_unparent(OBJECT(nf));
382     }
383 
384     /* If there is a peer NIC, delete and cleanup client, but do not free. */
385     if (nc->peer && nc->peer->info->type == NET_CLIENT_DRIVER_NIC) {
386         NICState *nic = qemu_get_nic(nc->peer);
387         if (nic->peer_deleted) {
388             return;
389         }
390         nic->peer_deleted = true;
391 
392         for (i = 0; i < queues; i++) {
393             ncs[i]->peer->link_down = true;
394         }
395 
396         if (nc->peer->info->link_status_changed) {
397             nc->peer->info->link_status_changed(nc->peer);
398         }
399 
400         for (i = 0; i < queues; i++) {
401             qemu_cleanup_net_client(ncs[i]);
402         }
403 
404         return;
405     }
406 
407     for (i = 0; i < queues; i++) {
408         qemu_cleanup_net_client(ncs[i]);
409         qemu_free_net_client(ncs[i]);
410     }
411 }
412 
413 void qemu_del_nic(NICState *nic)
414 {
415     int i, queues = MAX(nic->conf->peers.queues, 1);
416 
417     qemu_macaddr_set_free(&nic->conf->macaddr);
418 
419     for (i = 0; i < queues; i++) {
420         NetClientState *nc = qemu_get_subqueue(nic, i);
421         /* If this is a peer NIC and peer has already been deleted, free it now. */
422         if (nic->peer_deleted) {
423             qemu_free_net_client(nc->peer);
424         } else if (nc->peer) {
425             /* if there are RX packets pending, complete them */
426             qemu_purge_queued_packets(nc->peer);
427         }
428     }
429 
430     for (i = queues - 1; i >= 0; i--) {
431         NetClientState *nc = qemu_get_subqueue(nic, i);
432 
433         qemu_cleanup_net_client(nc);
434         qemu_free_net_client(nc);
435     }
436 
437     g_free(nic);
438 }
439 
440 void qemu_foreach_nic(qemu_nic_foreach func, void *opaque)
441 {
442     NetClientState *nc;
443 
444     QTAILQ_FOREACH(nc, &net_clients, next) {
445         if (nc->info->type == NET_CLIENT_DRIVER_NIC) {
446             if (nc->queue_index == 0) {
447                 func(qemu_get_nic(nc), opaque);
448             }
449         }
450     }
451 }
452 
453 bool qemu_has_ufo(NetClientState *nc)
454 {
455     if (!nc || !nc->info->has_ufo) {
456         return false;
457     }
458 
459     return nc->info->has_ufo(nc);
460 }
461 
462 bool qemu_has_vnet_hdr(NetClientState *nc)
463 {
464     if (!nc || !nc->info->has_vnet_hdr) {
465         return false;
466     }
467 
468     return nc->info->has_vnet_hdr(nc);
469 }
470 
471 bool qemu_has_vnet_hdr_len(NetClientState *nc, int len)
472 {
473     if (!nc || !nc->info->has_vnet_hdr_len) {
474         return false;
475     }
476 
477     return nc->info->has_vnet_hdr_len(nc, len);
478 }
479 
480 void qemu_using_vnet_hdr(NetClientState *nc, bool enable)
481 {
482     if (!nc || !nc->info->using_vnet_hdr) {
483         return;
484     }
485 
486     nc->info->using_vnet_hdr(nc, enable);
487 }
488 
489 void qemu_set_offload(NetClientState *nc, int csum, int tso4, int tso6,
490                           int ecn, int ufo)
491 {
492     if (!nc || !nc->info->set_offload) {
493         return;
494     }
495 
496     nc->info->set_offload(nc, csum, tso4, tso6, ecn, ufo);
497 }
498 
499 void qemu_set_vnet_hdr_len(NetClientState *nc, int len)
500 {
501     if (!nc || !nc->info->set_vnet_hdr_len) {
502         return;
503     }
504 
505     nc->vnet_hdr_len = len;
506     nc->info->set_vnet_hdr_len(nc, len);
507 }
508 
509 int qemu_set_vnet_le(NetClientState *nc, bool is_le)
510 {
511 #ifdef HOST_WORDS_BIGENDIAN
512     if (!nc || !nc->info->set_vnet_le) {
513         return -ENOSYS;
514     }
515 
516     return nc->info->set_vnet_le(nc, is_le);
517 #else
518     return 0;
519 #endif
520 }
521 
522 int qemu_set_vnet_be(NetClientState *nc, bool is_be)
523 {
524 #ifdef HOST_WORDS_BIGENDIAN
525     return 0;
526 #else
527     if (!nc || !nc->info->set_vnet_be) {
528         return -ENOSYS;
529     }
530 
531     return nc->info->set_vnet_be(nc, is_be);
532 #endif
533 }
534 
535 int qemu_can_receive_packet(NetClientState *nc)
536 {
537     if (nc->receive_disabled) {
538         return 0;
539     } else if (nc->info->can_receive &&
540                !nc->info->can_receive(nc)) {
541         return 0;
542     }
543     return 1;
544 }
545 
546 int qemu_can_send_packet(NetClientState *sender)
547 {
548     int vm_running = runstate_is_running();
549 
550     if (!vm_running) {
551         return 0;
552     }
553 
554     if (!sender->peer) {
555         return 1;
556     }
557 
558     return qemu_can_receive_packet(sender->peer);
559 }
560 
561 static ssize_t filter_receive_iov(NetClientState *nc,
562                                   NetFilterDirection direction,
563                                   NetClientState *sender,
564                                   unsigned flags,
565                                   const struct iovec *iov,
566                                   int iovcnt,
567                                   NetPacketSent *sent_cb)
568 {
569     ssize_t ret = 0;
570     NetFilterState *nf = NULL;
571 
572     if (direction == NET_FILTER_DIRECTION_TX) {
573         QTAILQ_FOREACH(nf, &nc->filters, next) {
574             ret = qemu_netfilter_receive(nf, direction, sender, flags, iov,
575                                          iovcnt, sent_cb);
576             if (ret) {
577                 return ret;
578             }
579         }
580     } else {
581         QTAILQ_FOREACH_REVERSE(nf, &nc->filters, next) {
582             ret = qemu_netfilter_receive(nf, direction, sender, flags, iov,
583                                          iovcnt, sent_cb);
584             if (ret) {
585                 return ret;
586             }
587         }
588     }
589 
590     return ret;
591 }
592 
593 static ssize_t filter_receive(NetClientState *nc,
594                               NetFilterDirection direction,
595                               NetClientState *sender,
596                               unsigned flags,
597                               const uint8_t *data,
598                               size_t size,
599                               NetPacketSent *sent_cb)
600 {
601     struct iovec iov = {
602         .iov_base = (void *)data,
603         .iov_len = size
604     };
605 
606     return filter_receive_iov(nc, direction, sender, flags, &iov, 1, sent_cb);
607 }
608 
609 void qemu_purge_queued_packets(NetClientState *nc)
610 {
611     if (!nc->peer) {
612         return;
613     }
614 
615     qemu_net_queue_purge(nc->peer->incoming_queue, nc);
616 }
617 
618 void qemu_flush_or_purge_queued_packets(NetClientState *nc, bool purge)
619 {
620     nc->receive_disabled = 0;
621 
622     if (nc->peer && nc->peer->info->type == NET_CLIENT_DRIVER_HUBPORT) {
623         if (net_hub_flush(nc->peer)) {
624             qemu_notify_event();
625         }
626     }
627     if (qemu_net_queue_flush(nc->incoming_queue)) {
628         /* We emptied the queue successfully, signal to the IO thread to repoll
629          * the file descriptor (for tap, for example).
630          */
631         qemu_notify_event();
632     } else if (purge) {
633         /* Unable to empty the queue, purge remaining packets */
634         qemu_net_queue_purge(nc->incoming_queue, nc->peer);
635     }
636 }
637 
638 void qemu_flush_queued_packets(NetClientState *nc)
639 {
640     qemu_flush_or_purge_queued_packets(nc, false);
641 }
642 
643 static ssize_t qemu_send_packet_async_with_flags(NetClientState *sender,
644                                                  unsigned flags,
645                                                  const uint8_t *buf, int size,
646                                                  NetPacketSent *sent_cb)
647 {
648     NetQueue *queue;
649     int ret;
650 
651 #ifdef DEBUG_NET
652     printf("qemu_send_packet_async:\n");
653     qemu_hexdump(stdout, "net", buf, size);
654 #endif
655 
656     if (sender->link_down || !sender->peer) {
657         return size;
658     }
659 
660     /* Let filters handle the packet first */
661     ret = filter_receive(sender, NET_FILTER_DIRECTION_TX,
662                          sender, flags, buf, size, sent_cb);
663     if (ret) {
664         return ret;
665     }
666 
667     ret = filter_receive(sender->peer, NET_FILTER_DIRECTION_RX,
668                          sender, flags, buf, size, sent_cb);
669     if (ret) {
670         return ret;
671     }
672 
673     queue = sender->peer->incoming_queue;
674 
675     return qemu_net_queue_send(queue, sender, flags, buf, size, sent_cb);
676 }
677 
678 ssize_t qemu_send_packet_async(NetClientState *sender,
679                                const uint8_t *buf, int size,
680                                NetPacketSent *sent_cb)
681 {
682     return qemu_send_packet_async_with_flags(sender, QEMU_NET_PACKET_FLAG_NONE,
683                                              buf, size, sent_cb);
684 }
685 
686 ssize_t qemu_send_packet(NetClientState *nc, const uint8_t *buf, int size)
687 {
688     return qemu_send_packet_async(nc, buf, size, NULL);
689 }
690 
691 ssize_t qemu_receive_packet(NetClientState *nc, const uint8_t *buf, int size)
692 {
693     if (!qemu_can_receive_packet(nc)) {
694         return 0;
695     }
696 
697     return qemu_net_queue_receive(nc->incoming_queue, buf, size);
698 }
699 
700 ssize_t qemu_receive_packet_iov(NetClientState *nc, const struct iovec *iov,
701                                 int iovcnt)
702 {
703     if (!qemu_can_receive_packet(nc)) {
704         return 0;
705     }
706 
707     return qemu_net_queue_receive_iov(nc->incoming_queue, iov, iovcnt);
708 }
709 
710 ssize_t qemu_send_packet_raw(NetClientState *nc, const uint8_t *buf, int size)
711 {
712     return qemu_send_packet_async_with_flags(nc, QEMU_NET_PACKET_FLAG_RAW,
713                                              buf, size, NULL);
714 }
715 
716 static ssize_t nc_sendv_compat(NetClientState *nc, const struct iovec *iov,
717                                int iovcnt, unsigned flags)
718 {
719     uint8_t *buf = NULL;
720     uint8_t *buffer;
721     size_t offset;
722     ssize_t ret;
723 
724     if (iovcnt == 1) {
725         buffer = iov[0].iov_base;
726         offset = iov[0].iov_len;
727     } else {
728         offset = iov_size(iov, iovcnt);
729         if (offset > NET_BUFSIZE) {
730             return -1;
731         }
732         buf = g_malloc(offset);
733         buffer = buf;
734         offset = iov_to_buf(iov, iovcnt, 0, buf, offset);
735     }
736 
737     if (flags & QEMU_NET_PACKET_FLAG_RAW && nc->info->receive_raw) {
738         ret = nc->info->receive_raw(nc, buffer, offset);
739     } else {
740         ret = nc->info->receive(nc, buffer, offset);
741     }
742 
743     g_free(buf);
744     return ret;
745 }
746 
747 static ssize_t qemu_deliver_packet_iov(NetClientState *sender,
748                                        unsigned flags,
749                                        const struct iovec *iov,
750                                        int iovcnt,
751                                        void *opaque)
752 {
753     NetClientState *nc = opaque;
754     int ret;
755 
756 
757     if (nc->link_down) {
758         return iov_size(iov, iovcnt);
759     }
760 
761     if (nc->receive_disabled) {
762         return 0;
763     }
764 
765     if (nc->info->receive_iov && !(flags & QEMU_NET_PACKET_FLAG_RAW)) {
766         ret = nc->info->receive_iov(nc, iov, iovcnt);
767     } else {
768         ret = nc_sendv_compat(nc, iov, iovcnt, flags);
769     }
770 
771     if (ret == 0) {
772         nc->receive_disabled = 1;
773     }
774 
775     return ret;
776 }
777 
778 ssize_t qemu_sendv_packet_async(NetClientState *sender,
779                                 const struct iovec *iov, int iovcnt,
780                                 NetPacketSent *sent_cb)
781 {
782     NetQueue *queue;
783     size_t size = iov_size(iov, iovcnt);
784     int ret;
785 
786     if (size > NET_BUFSIZE) {
787         return size;
788     }
789 
790     if (sender->link_down || !sender->peer) {
791         return size;
792     }
793 
794     /* Let filters handle the packet first */
795     ret = filter_receive_iov(sender, NET_FILTER_DIRECTION_TX, sender,
796                              QEMU_NET_PACKET_FLAG_NONE, iov, iovcnt, sent_cb);
797     if (ret) {
798         return ret;
799     }
800 
801     ret = filter_receive_iov(sender->peer, NET_FILTER_DIRECTION_RX, sender,
802                              QEMU_NET_PACKET_FLAG_NONE, iov, iovcnt, sent_cb);
803     if (ret) {
804         return ret;
805     }
806 
807     queue = sender->peer->incoming_queue;
808 
809     return qemu_net_queue_send_iov(queue, sender,
810                                    QEMU_NET_PACKET_FLAG_NONE,
811                                    iov, iovcnt, sent_cb);
812 }
813 
814 ssize_t
815 qemu_sendv_packet(NetClientState *nc, const struct iovec *iov, int iovcnt)
816 {
817     return qemu_sendv_packet_async(nc, iov, iovcnt, NULL);
818 }
819 
820 NetClientState *qemu_find_netdev(const char *id)
821 {
822     NetClientState *nc;
823 
824     QTAILQ_FOREACH(nc, &net_clients, next) {
825         if (nc->info->type == NET_CLIENT_DRIVER_NIC)
826             continue;
827         if (!strcmp(nc->name, id)) {
828             return nc;
829         }
830     }
831 
832     return NULL;
833 }
834 
835 int qemu_find_net_clients_except(const char *id, NetClientState **ncs,
836                                  NetClientDriver type, int max)
837 {
838     NetClientState *nc;
839     int ret = 0;
840 
841     QTAILQ_FOREACH(nc, &net_clients, next) {
842         if (nc->info->type == type) {
843             continue;
844         }
845         if (!id || !strcmp(nc->name, id)) {
846             if (ret < max) {
847                 ncs[ret] = nc;
848             }
849             ret++;
850         }
851     }
852 
853     return ret;
854 }
855 
856 static int nic_get_free_idx(void)
857 {
858     int index;
859 
860     for (index = 0; index < MAX_NICS; index++)
861         if (!nd_table[index].used)
862             return index;
863     return -1;
864 }
865 
866 int qemu_show_nic_models(const char *arg, const char *const *models)
867 {
868     int i;
869 
870     if (!arg || !is_help_option(arg)) {
871         return 0;
872     }
873 
874     printf("Supported NIC models:\n");
875     for (i = 0 ; models[i]; i++) {
876         printf("%s\n", models[i]);
877     }
878     return 1;
879 }
880 
881 void qemu_check_nic_model(NICInfo *nd, const char *model)
882 {
883     const char *models[2];
884 
885     models[0] = model;
886     models[1] = NULL;
887 
888     if (qemu_show_nic_models(nd->model, models))
889         exit(0);
890     if (qemu_find_nic_model(nd, models, model) < 0)
891         exit(1);
892 }
893 
894 int qemu_find_nic_model(NICInfo *nd, const char * const *models,
895                         const char *default_model)
896 {
897     int i;
898 
899     if (!nd->model)
900         nd->model = g_strdup(default_model);
901 
902     for (i = 0 ; models[i]; i++) {
903         if (strcmp(nd->model, models[i]) == 0)
904             return i;
905     }
906 
907     error_report("Unsupported NIC model: %s", nd->model);
908     return -1;
909 }
910 
911 static int net_init_nic(const Netdev *netdev, const char *name,
912                         NetClientState *peer, Error **errp)
913 {
914     int idx;
915     NICInfo *nd;
916     const NetLegacyNicOptions *nic;
917 
918     assert(netdev->type == NET_CLIENT_DRIVER_NIC);
919     nic = &netdev->u.nic;
920 
921     idx = nic_get_free_idx();
922     if (idx == -1 || nb_nics >= MAX_NICS) {
923         error_setg(errp, "too many NICs");
924         return -1;
925     }
926 
927     nd = &nd_table[idx];
928 
929     memset(nd, 0, sizeof(*nd));
930 
931     if (nic->has_netdev) {
932         nd->netdev = qemu_find_netdev(nic->netdev);
933         if (!nd->netdev) {
934             error_setg(errp, "netdev '%s' not found", nic->netdev);
935             return -1;
936         }
937     } else {
938         assert(peer);
939         nd->netdev = peer;
940     }
941     nd->name = g_strdup(name);
942     if (nic->has_model) {
943         nd->model = g_strdup(nic->model);
944     }
945     if (nic->has_addr) {
946         nd->devaddr = g_strdup(nic->addr);
947     }
948 
949     if (nic->has_macaddr &&
950         net_parse_macaddr(nd->macaddr.a, nic->macaddr) < 0) {
951         error_setg(errp, "invalid syntax for ethernet address");
952         return -1;
953     }
954     if (nic->has_macaddr &&
955         is_multicast_ether_addr(nd->macaddr.a)) {
956         error_setg(errp,
957                    "NIC cannot have multicast MAC address (odd 1st byte)");
958         return -1;
959     }
960     qemu_macaddr_default_if_unset(&nd->macaddr);
961 
962     if (nic->has_vectors) {
963         if (nic->vectors > 0x7ffffff) {
964             error_setg(errp, "invalid # of vectors: %"PRIu32, nic->vectors);
965             return -1;
966         }
967         nd->nvectors = nic->vectors;
968     } else {
969         nd->nvectors = DEV_NVECTORS_UNSPECIFIED;
970     }
971 
972     nd->used = 1;
973     nb_nics++;
974 
975     return idx;
976 }
977 
978 
979 static int (* const net_client_init_fun[NET_CLIENT_DRIVER__MAX])(
980     const Netdev *netdev,
981     const char *name,
982     NetClientState *peer, Error **errp) = {
983         [NET_CLIENT_DRIVER_NIC]       = net_init_nic,
984 #ifdef CONFIG_SLIRP
985         [NET_CLIENT_DRIVER_USER]      = net_init_slirp,
986 #endif
987         [NET_CLIENT_DRIVER_TAP]       = net_init_tap,
988         [NET_CLIENT_DRIVER_SOCKET]    = net_init_socket,
989 #ifdef CONFIG_VDE
990         [NET_CLIENT_DRIVER_VDE]       = net_init_vde,
991 #endif
992 #ifdef CONFIG_NETMAP
993         [NET_CLIENT_DRIVER_NETMAP]    = net_init_netmap,
994 #endif
995 #ifdef CONFIG_NET_BRIDGE
996         [NET_CLIENT_DRIVER_BRIDGE]    = net_init_bridge,
997 #endif
998         [NET_CLIENT_DRIVER_HUBPORT]   = net_init_hubport,
999 #ifdef CONFIG_VHOST_NET_USER
1000         [NET_CLIENT_DRIVER_VHOST_USER] = net_init_vhost_user,
1001 #endif
1002 #ifdef CONFIG_VHOST_NET_VDPA
1003         [NET_CLIENT_DRIVER_VHOST_VDPA] = net_init_vhost_vdpa,
1004 #endif
1005 #ifdef CONFIG_L2TPV3
1006         [NET_CLIENT_DRIVER_L2TPV3]    = net_init_l2tpv3,
1007 #endif
1008 };
1009 
1010 
1011 static int net_client_init1(const Netdev *netdev, bool is_netdev, Error **errp)
1012 {
1013     NetClientState *peer = NULL;
1014     NetClientState *nc;
1015 
1016     if (is_netdev) {
1017         if (netdev->type == NET_CLIENT_DRIVER_NIC ||
1018             !net_client_init_fun[netdev->type]) {
1019             error_setg(errp, QERR_INVALID_PARAMETER_VALUE, "type",
1020                        "a netdev backend type");
1021             return -1;
1022         }
1023     } else {
1024         if (netdev->type == NET_CLIENT_DRIVER_NONE) {
1025             return 0; /* nothing to do */
1026         }
1027         if (netdev->type == NET_CLIENT_DRIVER_HUBPORT ||
1028             !net_client_init_fun[netdev->type]) {
1029             error_setg(errp, QERR_INVALID_PARAMETER_VALUE, "type",
1030                        "a net backend type (maybe it is not compiled "
1031                        "into this binary)");
1032             return -1;
1033         }
1034 
1035         /* Do not add to a hub if it's a nic with a netdev= parameter. */
1036         if (netdev->type != NET_CLIENT_DRIVER_NIC ||
1037             !netdev->u.nic.has_netdev) {
1038             peer = net_hub_add_port(0, NULL, NULL);
1039         }
1040     }
1041 
1042     nc = qemu_find_netdev(netdev->id);
1043     if (nc) {
1044         error_setg(errp, "Duplicate ID '%s'", netdev->id);
1045         return -1;
1046     }
1047 
1048     if (net_client_init_fun[netdev->type](netdev, netdev->id, peer, errp) < 0) {
1049         /* FIXME drop when all init functions store an Error */
1050         if (errp && !*errp) {
1051             error_setg(errp, "Device '%s' could not be initialized",
1052                        NetClientDriver_str(netdev->type));
1053         }
1054         return -1;
1055     }
1056 
1057     if (is_netdev) {
1058         nc = qemu_find_netdev(netdev->id);
1059         assert(nc);
1060         nc->is_netdev = true;
1061     }
1062 
1063     return 0;
1064 }
1065 
1066 void show_netdevs(void)
1067 {
1068     int idx;
1069     const char *available_netdevs[] = {
1070         "socket",
1071         "hubport",
1072         "tap",
1073 #ifdef CONFIG_SLIRP
1074         "user",
1075 #endif
1076 #ifdef CONFIG_L2TPV3
1077         "l2tpv3",
1078 #endif
1079 #ifdef CONFIG_VDE
1080         "vde",
1081 #endif
1082 #ifdef CONFIG_NET_BRIDGE
1083         "bridge",
1084 #endif
1085 #ifdef CONFIG_NETMAP
1086         "netmap",
1087 #endif
1088 #ifdef CONFIG_POSIX
1089         "vhost-user",
1090 #endif
1091 #ifdef CONFIG_VHOST_VDPA
1092         "vhost-vdpa",
1093 #endif
1094     };
1095 
1096     qemu_printf("Available netdev backend types:\n");
1097     for (idx = 0; idx < ARRAY_SIZE(available_netdevs); idx++) {
1098         qemu_printf("%s\n", available_netdevs[idx]);
1099     }
1100 }
1101 
1102 static int net_client_init(QemuOpts *opts, bool is_netdev, Error **errp)
1103 {
1104     gchar **substrings = NULL;
1105     Netdev *object = NULL;
1106     int ret = -1;
1107     Visitor *v = opts_visitor_new(opts);
1108 
1109     /* Parse convenience option format ip6-net=fec0::0[/64] */
1110     const char *ip6_net = qemu_opt_get(opts, "ipv6-net");
1111 
1112     if (ip6_net) {
1113         char *prefix_addr;
1114         unsigned long prefix_len = 64; /* Default 64bit prefix length. */
1115 
1116         substrings = g_strsplit(ip6_net, "/", 2);
1117         if (!substrings || !substrings[0]) {
1118             error_setg(errp, QERR_INVALID_PARAMETER_VALUE, "ipv6-net",
1119                        "a valid IPv6 prefix");
1120             goto out;
1121         }
1122 
1123         prefix_addr = substrings[0];
1124 
1125         /* Handle user-specified prefix length. */
1126         if (substrings[1] &&
1127             qemu_strtoul(substrings[1], NULL, 10, &prefix_len))
1128         {
1129             error_setg(errp, QERR_INVALID_PARAMETER_VALUE,
1130                        "ipv6-prefixlen", "a number");
1131             goto out;
1132         }
1133 
1134         qemu_opt_set(opts, "ipv6-prefix", prefix_addr, &error_abort);
1135         qemu_opt_set_number(opts, "ipv6-prefixlen", prefix_len,
1136                             &error_abort);
1137         qemu_opt_unset(opts, "ipv6-net");
1138     }
1139 
1140     /* Create an ID for -net if the user did not specify one */
1141     if (!is_netdev && !qemu_opts_id(opts)) {
1142         qemu_opts_set_id(opts, id_generate(ID_NET));
1143     }
1144 
1145     if (visit_type_Netdev(v, NULL, &object, errp)) {
1146         ret = net_client_init1(object, is_netdev, errp);
1147     }
1148 
1149     qapi_free_Netdev(object);
1150 
1151 out:
1152     g_strfreev(substrings);
1153     visit_free(v);
1154     return ret;
1155 }
1156 
1157 void netdev_add(QemuOpts *opts, Error **errp)
1158 {
1159     net_client_init(opts, true, errp);
1160 }
1161 
1162 void qmp_netdev_add(Netdev *netdev, Error **errp)
1163 {
1164     if (!id_wellformed(netdev->id)) {
1165         error_setg(errp, QERR_INVALID_PARAMETER_VALUE, "id", "an identifier");
1166         return;
1167     }
1168 
1169     net_client_init1(netdev, true, errp);
1170 }
1171 
1172 void qmp_netdev_del(const char *id, Error **errp)
1173 {
1174     NetClientState *nc;
1175     QemuOpts *opts;
1176 
1177     nc = qemu_find_netdev(id);
1178     if (!nc) {
1179         error_set(errp, ERROR_CLASS_DEVICE_NOT_FOUND,
1180                   "Device '%s' not found", id);
1181         return;
1182     }
1183 
1184     if (!nc->is_netdev) {
1185         error_setg(errp, "Device '%s' is not a netdev", id);
1186         return;
1187     }
1188 
1189     qemu_del_net_client(nc);
1190 
1191     /*
1192      * Wart: we need to delete the QemuOpts associated with netdevs
1193      * created via CLI or HMP, to avoid bogus "Duplicate ID" errors in
1194      * HMP netdev_add.
1195      */
1196     opts = qemu_opts_find(qemu_find_opts("netdev"), id);
1197     if (opts) {
1198         qemu_opts_del(opts);
1199     }
1200 }
1201 
1202 static void netfilter_print_info(Monitor *mon, NetFilterState *nf)
1203 {
1204     char *str;
1205     ObjectProperty *prop;
1206     ObjectPropertyIterator iter;
1207     Visitor *v;
1208 
1209     /* generate info str */
1210     object_property_iter_init(&iter, OBJECT(nf));
1211     while ((prop = object_property_iter_next(&iter))) {
1212         if (!strcmp(prop->name, "type")) {
1213             continue;
1214         }
1215         v = string_output_visitor_new(false, &str);
1216         object_property_get(OBJECT(nf), prop->name, v, NULL);
1217         visit_complete(v, &str);
1218         visit_free(v);
1219         monitor_printf(mon, ",%s=%s", prop->name, str);
1220         g_free(str);
1221     }
1222     monitor_printf(mon, "\n");
1223 }
1224 
1225 static char *generate_info_str(NetClientState *nc)
1226 {
1227     NetdevInfo *ni = nc->stored_config;
1228     char *ret_out = NULL;
1229     Visitor *v;
1230 
1231     /* Use legacy field info_str for NIC and hubports */
1232     if ((nc->info->type == NET_CLIENT_DRIVER_NIC) ||
1233         (nc->info->type == NET_CLIENT_DRIVER_HUBPORT)) {
1234         return g_strdup(nc->info_str ? nc->info_str : "");
1235     }
1236 
1237     if (!ni) {
1238         return g_malloc0(1);
1239     }
1240 
1241     v = hmp_output_visitor_new(&ret_out);
1242     if (visit_type_NetdevInfo(v, "", &ni, NULL)) {
1243         visit_complete(v, &ret_out);
1244     }
1245     visit_free(v);
1246 
1247     return ret_out;
1248 }
1249 
1250 void print_net_client(Monitor *mon, NetClientState *nc)
1251 {
1252     NetFilterState *nf;
1253     char *info_str = generate_info_str(nc);
1254 
1255     monitor_printf(mon, "%s: index=%d,type=%s,%s\n", nc->name,
1256                    nc->queue_index,
1257                    NetClientDriver_str(nc->info->type),
1258                    info_str);
1259     g_free(info_str);
1260 
1261     if (!QTAILQ_EMPTY(&nc->filters)) {
1262         monitor_printf(mon, "filters:\n");
1263     }
1264     QTAILQ_FOREACH(nf, &nc->filters, next) {
1265         monitor_printf(mon, "  - %s: type=%s",
1266                        object_get_canonical_path_component(OBJECT(nf)),
1267                        object_get_typename(OBJECT(nf)));
1268         netfilter_print_info(mon, nf);
1269     }
1270 }
1271 
1272 RxFilterInfoList *qmp_query_rx_filter(bool has_name, const char *name,
1273                                       Error **errp)
1274 {
1275     NetClientState *nc;
1276     RxFilterInfoList *filter_list = NULL, **tail = &filter_list;
1277 
1278     QTAILQ_FOREACH(nc, &net_clients, next) {
1279         RxFilterInfo *info;
1280 
1281         if (has_name && strcmp(nc->name, name) != 0) {
1282             continue;
1283         }
1284 
1285         /* only query rx-filter information of NIC */
1286         if (nc->info->type != NET_CLIENT_DRIVER_NIC) {
1287             if (has_name) {
1288                 error_setg(errp, "net client(%s) isn't a NIC", name);
1289                 assert(!filter_list);
1290                 return NULL;
1291             }
1292             continue;
1293         }
1294 
1295         /* only query information on queue 0 since the info is per nic,
1296          * not per queue
1297          */
1298         if (nc->queue_index != 0)
1299             continue;
1300 
1301         if (nc->info->query_rx_filter) {
1302             info = nc->info->query_rx_filter(nc);
1303             QAPI_LIST_APPEND(tail, info);
1304         } else if (has_name) {
1305             error_setg(errp, "net client(%s) doesn't support"
1306                        " rx-filter querying", name);
1307             assert(!filter_list);
1308             return NULL;
1309         }
1310 
1311         if (has_name) {
1312             break;
1313         }
1314     }
1315 
1316     if (filter_list == NULL && has_name) {
1317         error_setg(errp, "invalid net client name: %s", name);
1318     }
1319 
1320     return filter_list;
1321 }
1322 
1323 NetdevInfoList *qmp_query_netdev(Error **errp)
1324 {
1325     NetdevInfoList *list = NULL;
1326     NetClientState *nc;
1327 
1328     QTAILQ_FOREACH(nc, &net_clients, next) {
1329         /*
1330          * Only look at netdevs (backend network devices), not for each queue
1331          * or NIC / hubport
1332          */
1333         if (nc->stored_config) {
1334             NetdevInfo *element = QAPI_CLONE(NetdevInfo, nc->stored_config);
1335 
1336             g_free(element->id); /* Need to dealloc empty id after clone */
1337             element->id = g_strdup(nc->name);
1338 
1339             element->has_peer_id = nc->peer != NULL;
1340             if (element->has_peer_id) {
1341                 element->peer_id = g_strdup(nc->peer->name);
1342             }
1343 
1344             QAPI_LIST_PREPEND(list, element);
1345         }
1346     }
1347 
1348     return list;
1349 }
1350 
1351 void hmp_info_network(Monitor *mon, const QDict *qdict)
1352 {
1353     NetClientState *nc, *peer;
1354     NetClientDriver type;
1355 
1356     net_hub_info(mon);
1357 
1358     QTAILQ_FOREACH(nc, &net_clients, next) {
1359         peer = nc->peer;
1360         type = nc->info->type;
1361 
1362         /* Skip if already printed in hub info */
1363         if (net_hub_id_for_client(nc, NULL) == 0) {
1364             continue;
1365         }
1366 
1367         if (!peer || type == NET_CLIENT_DRIVER_NIC) {
1368             print_net_client(mon, nc);
1369         } /* else it's a netdev connected to a NIC, printed with the NIC */
1370         if (peer && type == NET_CLIENT_DRIVER_NIC) {
1371             monitor_printf(mon, " \\ ");
1372             print_net_client(mon, peer);
1373         }
1374     }
1375 }
1376 
1377 void colo_notify_filters_event(int event, Error **errp)
1378 {
1379     NetClientState *nc;
1380     NetFilterState *nf;
1381     NetFilterClass *nfc = NULL;
1382     Error *local_err = NULL;
1383 
1384     QTAILQ_FOREACH(nc, &net_clients, next) {
1385         QTAILQ_FOREACH(nf, &nc->filters, next) {
1386             nfc = NETFILTER_GET_CLASS(OBJECT(nf));
1387             nfc->handle_event(nf, event, &local_err);
1388             if (local_err) {
1389                 error_propagate(errp, local_err);
1390                 return;
1391             }
1392         }
1393     }
1394 }
1395 
1396 void qmp_set_link(const char *name, bool up, Error **errp)
1397 {
1398     NetClientState *ncs[MAX_QUEUE_NUM];
1399     NetClientState *nc;
1400     int queues, i;
1401 
1402     queues = qemu_find_net_clients_except(name, ncs,
1403                                           NET_CLIENT_DRIVER__MAX,
1404                                           MAX_QUEUE_NUM);
1405 
1406     if (queues == 0) {
1407         error_set(errp, ERROR_CLASS_DEVICE_NOT_FOUND,
1408                   "Device '%s' not found", name);
1409         return;
1410     }
1411     nc = ncs[0];
1412 
1413     for (i = 0; i < queues; i++) {
1414         ncs[i]->link_down = !up;
1415     }
1416 
1417     if (nc->info->link_status_changed) {
1418         nc->info->link_status_changed(nc);
1419     }
1420 
1421     if (nc->peer) {
1422         /* Change peer link only if the peer is NIC and then notify peer.
1423          * If the peer is a HUBPORT or a backend, we do not change the
1424          * link status.
1425          *
1426          * This behavior is compatible with qemu hubs where there could be
1427          * multiple clients that can still communicate with each other in
1428          * disconnected mode. For now maintain this compatibility.
1429          */
1430         if (nc->peer->info->type == NET_CLIENT_DRIVER_NIC) {
1431             for (i = 0; i < queues; i++) {
1432                 ncs[i]->peer->link_down = !up;
1433             }
1434         }
1435         if (nc->peer->info->link_status_changed) {
1436             nc->peer->info->link_status_changed(nc->peer);
1437         }
1438     }
1439 }
1440 
1441 static void net_vm_change_state_handler(void *opaque, bool running,
1442                                         RunState state)
1443 {
1444     NetClientState *nc;
1445     NetClientState *tmp;
1446 
1447     QTAILQ_FOREACH_SAFE(nc, &net_clients, next, tmp) {
1448         if (running) {
1449             /* Flush queued packets and wake up backends. */
1450             if (nc->peer && qemu_can_send_packet(nc)) {
1451                 qemu_flush_queued_packets(nc->peer);
1452             }
1453         } else {
1454             /* Complete all queued packets, to guarantee we don't modify
1455              * state later when VM is not running.
1456              */
1457             qemu_flush_or_purge_queued_packets(nc, true);
1458         }
1459     }
1460 }
1461 
1462 void net_cleanup(void)
1463 {
1464     NetClientState *nc;
1465 
1466     /* We may del multiple entries during qemu_del_net_client(),
1467      * so QTAILQ_FOREACH_SAFE() is also not safe here.
1468      */
1469     while (!QTAILQ_EMPTY(&net_clients)) {
1470         nc = QTAILQ_FIRST(&net_clients);
1471         if (nc->info->type == NET_CLIENT_DRIVER_NIC) {
1472             qemu_del_nic(qemu_get_nic(nc));
1473         } else {
1474             qemu_del_net_client(nc);
1475         }
1476     }
1477 
1478     qemu_del_vm_change_state_handler(net_change_state_entry);
1479 }
1480 
1481 void net_check_clients(void)
1482 {
1483     NetClientState *nc;
1484     int i;
1485 
1486     net_hub_check_clients();
1487 
1488     QTAILQ_FOREACH(nc, &net_clients, next) {
1489         if (!nc->peer) {
1490             warn_report("%s %s has no peer",
1491                         nc->info->type == NET_CLIENT_DRIVER_NIC
1492                         ? "nic" : "netdev",
1493                         nc->name);
1494         }
1495     }
1496 
1497     /* Check that all NICs requested via -net nic actually got created.
1498      * NICs created via -device don't need to be checked here because
1499      * they are always instantiated.
1500      */
1501     for (i = 0; i < MAX_NICS; i++) {
1502         NICInfo *nd = &nd_table[i];
1503         if (nd->used && !nd->instantiated) {
1504             warn_report("requested NIC (%s, model %s) "
1505                         "was not created (not supported by this machine?)",
1506                         nd->name ? nd->name : "anonymous",
1507                         nd->model ? nd->model : "unspecified");
1508         }
1509     }
1510 }
1511 
1512 static int net_init_client(void *dummy, QemuOpts *opts, Error **errp)
1513 {
1514     return net_client_init(opts, false, errp);
1515 }
1516 
1517 static int net_init_netdev(void *dummy, QemuOpts *opts, Error **errp)
1518 {
1519     const char *type = qemu_opt_get(opts, "type");
1520 
1521     if (type && is_help_option(type)) {
1522         show_netdevs();
1523         exit(0);
1524     }
1525     return net_client_init(opts, true, errp);
1526 }
1527 
1528 /* For the convenience "--nic" parameter */
1529 static int net_param_nic(void *dummy, QemuOpts *opts, Error **errp)
1530 {
1531     char *mac, *nd_id;
1532     int idx, ret;
1533     NICInfo *ni;
1534     const char *type;
1535 
1536     type = qemu_opt_get(opts, "type");
1537     if (type && g_str_equal(type, "none")) {
1538         return 0;    /* Nothing to do, default_net is cleared in vl.c */
1539     }
1540 
1541     idx = nic_get_free_idx();
1542     if (idx == -1 || nb_nics >= MAX_NICS) {
1543         error_setg(errp, "no more on-board/default NIC slots available");
1544         return -1;
1545     }
1546 
1547     if (!type) {
1548         qemu_opt_set(opts, "type", "user", &error_abort);
1549     }
1550 
1551     ni = &nd_table[idx];
1552     memset(ni, 0, sizeof(*ni));
1553     ni->model = qemu_opt_get_del(opts, "model");
1554 
1555     /* Create an ID if the user did not specify one */
1556     nd_id = g_strdup(qemu_opts_id(opts));
1557     if (!nd_id) {
1558         nd_id = id_generate(ID_NET);
1559         qemu_opts_set_id(opts, nd_id);
1560     }
1561 
1562     /* Handle MAC address */
1563     mac = qemu_opt_get_del(opts, "mac");
1564     if (mac) {
1565         ret = net_parse_macaddr(ni->macaddr.a, mac);
1566         g_free(mac);
1567         if (ret) {
1568             error_setg(errp, "invalid syntax for ethernet address");
1569             goto out;
1570         }
1571         if (is_multicast_ether_addr(ni->macaddr.a)) {
1572             error_setg(errp, "NIC cannot have multicast MAC address");
1573             ret = -1;
1574             goto out;
1575         }
1576     }
1577     qemu_macaddr_default_if_unset(&ni->macaddr);
1578 
1579     ret = net_client_init(opts, true, errp);
1580     if (ret == 0) {
1581         ni->netdev = qemu_find_netdev(nd_id);
1582         ni->used = true;
1583         nb_nics++;
1584     }
1585 
1586 out:
1587     g_free(nd_id);
1588     return ret;
1589 }
1590 
1591 int net_init_clients(Error **errp)
1592 {
1593     net_change_state_entry =
1594         qemu_add_vm_change_state_handler(net_vm_change_state_handler, NULL);
1595 
1596     QTAILQ_INIT(&net_clients);
1597 
1598     if (qemu_opts_foreach(qemu_find_opts("netdev"),
1599                           net_init_netdev, NULL, errp)) {
1600         return -1;
1601     }
1602 
1603     if (qemu_opts_foreach(qemu_find_opts("nic"), net_param_nic, NULL, errp)) {
1604         return -1;
1605     }
1606 
1607     if (qemu_opts_foreach(qemu_find_opts("net"), net_init_client, NULL, errp)) {
1608         return -1;
1609     }
1610 
1611     return 0;
1612 }
1613 
1614 int net_client_parse(QemuOptsList *opts_list, const char *optarg)
1615 {
1616     if (!qemu_opts_parse_noisily(opts_list, optarg, true)) {
1617         return -1;
1618     }
1619 
1620     return 0;
1621 }
1622 
1623 /* From FreeBSD */
1624 /* XXX: optimize */
1625 uint32_t net_crc32(const uint8_t *p, int len)
1626 {
1627     uint32_t crc;
1628     int carry, i, j;
1629     uint8_t b;
1630 
1631     crc = 0xffffffff;
1632     for (i = 0; i < len; i++) {
1633         b = *p++;
1634         for (j = 0; j < 8; j++) {
1635             carry = ((crc & 0x80000000L) ? 1 : 0) ^ (b & 0x01);
1636             crc <<= 1;
1637             b >>= 1;
1638             if (carry) {
1639                 crc = ((crc ^ POLYNOMIAL_BE) | carry);
1640             }
1641         }
1642     }
1643 
1644     return crc;
1645 }
1646 
1647 uint32_t net_crc32_le(const uint8_t *p, int len)
1648 {
1649     uint32_t crc;
1650     int carry, i, j;
1651     uint8_t b;
1652 
1653     crc = 0xffffffff;
1654     for (i = 0; i < len; i++) {
1655         b = *p++;
1656         for (j = 0; j < 8; j++) {
1657             carry = (crc & 0x1) ^ (b & 0x01);
1658             crc >>= 1;
1659             b >>= 1;
1660             if (carry) {
1661                 crc ^= POLYNOMIAL_LE;
1662             }
1663         }
1664     }
1665 
1666     return crc;
1667 }
1668 
1669 QemuOptsList qemu_netdev_opts = {
1670     .name = "netdev",
1671     .implied_opt_name = "type",
1672     .head = QTAILQ_HEAD_INITIALIZER(qemu_netdev_opts.head),
1673     .desc = {
1674         /*
1675          * no elements => accept any params
1676          * validation will happen later
1677          */
1678         { /* end of list */ }
1679     },
1680 };
1681 
1682 QemuOptsList qemu_nic_opts = {
1683     .name = "nic",
1684     .implied_opt_name = "type",
1685     .head = QTAILQ_HEAD_INITIALIZER(qemu_nic_opts.head),
1686     .desc = {
1687         /*
1688          * no elements => accept any params
1689          * validation will happen later
1690          */
1691         { /* end of list */ }
1692     },
1693 };
1694 
1695 QemuOptsList qemu_net_opts = {
1696     .name = "net",
1697     .implied_opt_name = "type",
1698     .head = QTAILQ_HEAD_INITIALIZER(qemu_net_opts.head),
1699     .desc = {
1700         /*
1701          * no elements => accept any params
1702          * validation will happen later
1703          */
1704         { /* end of list */ }
1705     },
1706 };
1707 
1708 void net_socket_rs_init(SocketReadState *rs,
1709                         SocketReadStateFinalize *finalize,
1710                         bool vnet_hdr)
1711 {
1712     rs->state = 0;
1713     rs->vnet_hdr = vnet_hdr;
1714     rs->index = 0;
1715     rs->packet_len = 0;
1716     rs->vnet_hdr_len = 0;
1717     memset(rs->buf, 0, sizeof(rs->buf));
1718     rs->finalize = finalize;
1719 }
1720 
1721 /*
1722  * Returns
1723  * 0: success
1724  * -1: error occurs
1725  */
1726 int net_fill_rstate(SocketReadState *rs, const uint8_t *buf, int size)
1727 {
1728     unsigned int l;
1729 
1730     while (size > 0) {
1731         /* Reassemble a packet from the network.
1732          * 0 = getting length.
1733          * 1 = getting vnet header length.
1734          * 2 = getting data.
1735          */
1736         switch (rs->state) {
1737         case 0:
1738             l = 4 - rs->index;
1739             if (l > size) {
1740                 l = size;
1741             }
1742             memcpy(rs->buf + rs->index, buf, l);
1743             buf += l;
1744             size -= l;
1745             rs->index += l;
1746             if (rs->index == 4) {
1747                 /* got length */
1748                 rs->packet_len = ntohl(*(uint32_t *)rs->buf);
1749                 rs->index = 0;
1750                 if (rs->vnet_hdr) {
1751                     rs->state = 1;
1752                 } else {
1753                     rs->state = 2;
1754                     rs->vnet_hdr_len = 0;
1755                 }
1756             }
1757             break;
1758         case 1:
1759             l = 4 - rs->index;
1760             if (l > size) {
1761                 l = size;
1762             }
1763             memcpy(rs->buf + rs->index, buf, l);
1764             buf += l;
1765             size -= l;
1766             rs->index += l;
1767             if (rs->index == 4) {
1768                 /* got vnet header length */
1769                 rs->vnet_hdr_len = ntohl(*(uint32_t *)rs->buf);
1770                 rs->index = 0;
1771                 rs->state = 2;
1772             }
1773             break;
1774         case 2:
1775             l = rs->packet_len - rs->index;
1776             if (l > size) {
1777                 l = size;
1778             }
1779             if (rs->index + l <= sizeof(rs->buf)) {
1780                 memcpy(rs->buf + rs->index, buf, l);
1781             } else {
1782                 fprintf(stderr, "serious error: oversized packet received,"
1783                     "connection terminated.\n");
1784                 rs->index = rs->state = 0;
1785                 return -1;
1786             }
1787 
1788             rs->index += l;
1789             buf += l;
1790             size -= l;
1791             if (rs->index >= rs->packet_len) {
1792                 rs->index = 0;
1793                 rs->state = 0;
1794                 assert(rs->finalize);
1795                 rs->finalize(rs);
1796             }
1797             break;
1798         }
1799     }
1800 
1801     assert(size == 0);
1802     return 0;
1803 }
1804