xref: /openbmc/qemu/net/net.c (revision 89fc45d5)
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/qapi-visit-net.h"
40 #include "qapi/qmp/qdict.h"
41 #include "qapi/qmp/qerror.h"
42 #include "qemu/error-report.h"
43 #include "qemu/sockets.h"
44 #include "qemu/cutils.h"
45 #include "qemu/config-file.h"
46 #include "qemu/ctype.h"
47 #include "qemu/id.h"
48 #include "qemu/iov.h"
49 #include "qemu/qemu-print.h"
50 #include "qemu/main-loop.h"
51 #include "qemu/option.h"
52 #include "qapi/error.h"
53 #include "qapi/opts-visitor.h"
54 #include "sysemu/runstate.h"
55 #include "net/colo-compare.h"
56 #include "net/filter.h"
57 #include "qapi/string-output-visitor.h"
58 
59 /* Net bridge is currently not supported for W32. */
60 #if !defined(_WIN32)
61 # define CONFIG_NET_BRIDGE
62 #endif
63 
64 static VMChangeStateEntry *net_change_state_entry;
65 static QTAILQ_HEAD(, NetClientState) net_clients;
66 
67 /***********************************************************/
68 /* network device redirectors */
69 
70 int parse_host_port(struct sockaddr_in *saddr, const char *str,
71                     Error **errp)
72 {
73     gchar **substrings;
74     struct hostent *he;
75     const char *addr, *p, *r;
76     int port, ret = 0;
77 
78     memset(saddr, 0, sizeof(*saddr));
79 
80     substrings = g_strsplit(str, ":", 2);
81     if (!substrings || !substrings[0] || !substrings[1]) {
82         error_setg(errp, "host address '%s' doesn't contain ':' "
83                    "separating host from port", str);
84         ret = -1;
85         goto out;
86     }
87 
88     addr = substrings[0];
89     p = substrings[1];
90 
91     saddr->sin_family = AF_INET;
92     if (addr[0] == '\0') {
93         saddr->sin_addr.s_addr = 0;
94     } else {
95         if (qemu_isdigit(addr[0])) {
96             if (!inet_aton(addr, &saddr->sin_addr)) {
97                 error_setg(errp, "host address '%s' is not a valid "
98                            "IPv4 address", addr);
99                 ret = -1;
100                 goto out;
101             }
102         } else {
103             he = gethostbyname(addr);
104             if (he == NULL) {
105                 error_setg(errp, "can't resolve host address '%s'", addr);
106                 ret = -1;
107                 goto out;
108             }
109             saddr->sin_addr = *(struct in_addr *)he->h_addr;
110         }
111     }
112     port = strtol(p, (char **)&r, 0);
113     if (r == p) {
114         error_setg(errp, "port number '%s' is invalid", p);
115         ret = -1;
116         goto out;
117     }
118     saddr->sin_port = htons(port);
119 
120 out:
121     g_strfreev(substrings);
122     return ret;
123 }
124 
125 char *qemu_mac_strdup_printf(const uint8_t *macaddr)
126 {
127     return g_strdup_printf("%.2x:%.2x:%.2x:%.2x:%.2x:%.2x",
128                            macaddr[0], macaddr[1], macaddr[2],
129                            macaddr[3], macaddr[4], macaddr[5]);
130 }
131 
132 void qemu_format_nic_info_str(NetClientState *nc, uint8_t macaddr[6])
133 {
134     snprintf(nc->info_str, sizeof(nc->info_str),
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                                   bool is_datapath)
244 {
245     nc->info = info;
246     nc->model = g_strdup(model);
247     if (name) {
248         nc->name = g_strdup(name);
249     } else {
250         nc->name = assign_name(nc, model);
251     }
252 
253     if (peer) {
254         assert(!peer->peer);
255         nc->peer = peer;
256         peer->peer = nc;
257     }
258     QTAILQ_INSERT_TAIL(&net_clients, nc, next);
259 
260     nc->incoming_queue = qemu_new_net_queue(qemu_deliver_packet_iov, nc);
261     nc->destructor = destructor;
262     nc->is_datapath = is_datapath;
263     QTAILQ_INIT(&nc->filters);
264 }
265 
266 NetClientState *qemu_new_net_client(NetClientInfo *info,
267                                     NetClientState *peer,
268                                     const char *model,
269                                     const char *name)
270 {
271     NetClientState *nc;
272 
273     assert(info->size >= sizeof(NetClientState));
274 
275     nc = g_malloc0(info->size);
276     qemu_net_client_setup(nc, info, peer, model, name,
277                           qemu_net_client_destructor, true);
278 
279     return nc;
280 }
281 
282 NetClientState *qemu_new_net_control_client(NetClientInfo *info,
283                                             NetClientState *peer,
284                                             const char *model,
285                                             const char *name)
286 {
287     NetClientState *nc;
288 
289     assert(info->size >= sizeof(NetClientState));
290 
291     nc = g_malloc0(info->size);
292     qemu_net_client_setup(nc, info, peer, model, name,
293                           qemu_net_client_destructor, false);
294 
295     return nc;
296 }
297 
298 NICState *qemu_new_nic(NetClientInfo *info,
299                        NICConf *conf,
300                        const char *model,
301                        const char *name,
302                        void *opaque)
303 {
304     NetClientState **peers = conf->peers.ncs;
305     NICState *nic;
306     int i, queues = MAX(1, conf->peers.queues);
307 
308     assert(info->type == NET_CLIENT_DRIVER_NIC);
309     assert(info->size >= sizeof(NICState));
310 
311     nic = g_malloc0(info->size + sizeof(NetClientState) * queues);
312     nic->ncs = (void *)nic + info->size;
313     nic->conf = conf;
314     nic->opaque = opaque;
315 
316     for (i = 0; i < queues; i++) {
317         qemu_net_client_setup(&nic->ncs[i], info, peers[i], model, name,
318                               NULL, true);
319         nic->ncs[i].queue_index = i;
320     }
321 
322     return nic;
323 }
324 
325 NetClientState *qemu_get_subqueue(NICState *nic, int queue_index)
326 {
327     return nic->ncs + queue_index;
328 }
329 
330 NetClientState *qemu_get_queue(NICState *nic)
331 {
332     return qemu_get_subqueue(nic, 0);
333 }
334 
335 NICState *qemu_get_nic(NetClientState *nc)
336 {
337     NetClientState *nc0 = nc - nc->queue_index;
338 
339     return (NICState *)((void *)nc0 - nc->info->size);
340 }
341 
342 void *qemu_get_nic_opaque(NetClientState *nc)
343 {
344     NICState *nic = qemu_get_nic(nc);
345 
346     return nic->opaque;
347 }
348 
349 NetClientState *qemu_get_peer(NetClientState *nc, int queue_index)
350 {
351     assert(nc != NULL);
352     NetClientState *ncs = nc + queue_index;
353     return ncs->peer;
354 }
355 
356 static void qemu_cleanup_net_client(NetClientState *nc)
357 {
358     QTAILQ_REMOVE(&net_clients, nc, next);
359 
360     if (nc->info->cleanup) {
361         nc->info->cleanup(nc);
362     }
363 }
364 
365 static void qemu_free_net_client(NetClientState *nc)
366 {
367     if (nc->incoming_queue) {
368         qemu_del_net_queue(nc->incoming_queue);
369     }
370     if (nc->peer) {
371         nc->peer->peer = NULL;
372     }
373     g_free(nc->name);
374     g_free(nc->model);
375     if (nc->destructor) {
376         nc->destructor(nc);
377     }
378 }
379 
380 void qemu_del_net_client(NetClientState *nc)
381 {
382     NetClientState *ncs[MAX_QUEUE_NUM];
383     int queues, i;
384     NetFilterState *nf, *next;
385 
386     assert(nc->info->type != NET_CLIENT_DRIVER_NIC);
387 
388     /* If the NetClientState belongs to a multiqueue backend, we will change all
389      * other NetClientStates also.
390      */
391     queues = qemu_find_net_clients_except(nc->name, ncs,
392                                           NET_CLIENT_DRIVER_NIC,
393                                           MAX_QUEUE_NUM);
394     assert(queues != 0);
395 
396     QTAILQ_FOREACH_SAFE(nf, &nc->filters, next, next) {
397         object_unparent(OBJECT(nf));
398     }
399 
400     /* If there is a peer NIC, delete and cleanup client, but do not free. */
401     if (nc->peer && nc->peer->info->type == NET_CLIENT_DRIVER_NIC) {
402         NICState *nic = qemu_get_nic(nc->peer);
403         if (nic->peer_deleted) {
404             return;
405         }
406         nic->peer_deleted = true;
407 
408         for (i = 0; i < queues; i++) {
409             ncs[i]->peer->link_down = true;
410         }
411 
412         if (nc->peer->info->link_status_changed) {
413             nc->peer->info->link_status_changed(nc->peer);
414         }
415 
416         for (i = 0; i < queues; i++) {
417             qemu_cleanup_net_client(ncs[i]);
418         }
419 
420         return;
421     }
422 
423     for (i = 0; i < queues; i++) {
424         qemu_cleanup_net_client(ncs[i]);
425         qemu_free_net_client(ncs[i]);
426     }
427 }
428 
429 void qemu_del_nic(NICState *nic)
430 {
431     int i, queues = MAX(nic->conf->peers.queues, 1);
432 
433     qemu_macaddr_set_free(&nic->conf->macaddr);
434 
435     for (i = 0; i < queues; i++) {
436         NetClientState *nc = qemu_get_subqueue(nic, i);
437         /* If this is a peer NIC and peer has already been deleted, free it now. */
438         if (nic->peer_deleted) {
439             qemu_free_net_client(nc->peer);
440         } else if (nc->peer) {
441             /* if there are RX packets pending, complete them */
442             qemu_purge_queued_packets(nc->peer);
443         }
444     }
445 
446     for (i = queues - 1; i >= 0; i--) {
447         NetClientState *nc = qemu_get_subqueue(nic, i);
448 
449         qemu_cleanup_net_client(nc);
450         qemu_free_net_client(nc);
451     }
452 
453     g_free(nic);
454 }
455 
456 void qemu_foreach_nic(qemu_nic_foreach func, void *opaque)
457 {
458     NetClientState *nc;
459 
460     QTAILQ_FOREACH(nc, &net_clients, next) {
461         if (nc->info->type == NET_CLIENT_DRIVER_NIC) {
462             if (nc->queue_index == 0) {
463                 func(qemu_get_nic(nc), opaque);
464             }
465         }
466     }
467 }
468 
469 bool qemu_has_ufo(NetClientState *nc)
470 {
471     if (!nc || !nc->info->has_ufo) {
472         return false;
473     }
474 
475     return nc->info->has_ufo(nc);
476 }
477 
478 bool qemu_has_vnet_hdr(NetClientState *nc)
479 {
480     if (!nc || !nc->info->has_vnet_hdr) {
481         return false;
482     }
483 
484     return nc->info->has_vnet_hdr(nc);
485 }
486 
487 bool qemu_has_vnet_hdr_len(NetClientState *nc, int len)
488 {
489     if (!nc || !nc->info->has_vnet_hdr_len) {
490         return false;
491     }
492 
493     return nc->info->has_vnet_hdr_len(nc, len);
494 }
495 
496 void qemu_using_vnet_hdr(NetClientState *nc, bool enable)
497 {
498     if (!nc || !nc->info->using_vnet_hdr) {
499         return;
500     }
501 
502     nc->info->using_vnet_hdr(nc, enable);
503 }
504 
505 void qemu_set_offload(NetClientState *nc, int csum, int tso4, int tso6,
506                           int ecn, int ufo)
507 {
508     if (!nc || !nc->info->set_offload) {
509         return;
510     }
511 
512     nc->info->set_offload(nc, csum, tso4, tso6, ecn, ufo);
513 }
514 
515 void qemu_set_vnet_hdr_len(NetClientState *nc, int len)
516 {
517     if (!nc || !nc->info->set_vnet_hdr_len) {
518         return;
519     }
520 
521     nc->vnet_hdr_len = len;
522     nc->info->set_vnet_hdr_len(nc, len);
523 }
524 
525 int qemu_set_vnet_le(NetClientState *nc, bool is_le)
526 {
527 #if HOST_BIG_ENDIAN
528     if (!nc || !nc->info->set_vnet_le) {
529         return -ENOSYS;
530     }
531 
532     return nc->info->set_vnet_le(nc, is_le);
533 #else
534     return 0;
535 #endif
536 }
537 
538 int qemu_set_vnet_be(NetClientState *nc, bool is_be)
539 {
540 #if HOST_BIG_ENDIAN
541     return 0;
542 #else
543     if (!nc || !nc->info->set_vnet_be) {
544         return -ENOSYS;
545     }
546 
547     return nc->info->set_vnet_be(nc, is_be);
548 #endif
549 }
550 
551 int qemu_can_receive_packet(NetClientState *nc)
552 {
553     if (nc->receive_disabled) {
554         return 0;
555     } else if (nc->info->can_receive &&
556                !nc->info->can_receive(nc)) {
557         return 0;
558     }
559     return 1;
560 }
561 
562 int qemu_can_send_packet(NetClientState *sender)
563 {
564     int vm_running = runstate_is_running();
565 
566     if (!vm_running) {
567         return 0;
568     }
569 
570     if (!sender->peer) {
571         return 1;
572     }
573 
574     return qemu_can_receive_packet(sender->peer);
575 }
576 
577 static ssize_t filter_receive_iov(NetClientState *nc,
578                                   NetFilterDirection direction,
579                                   NetClientState *sender,
580                                   unsigned flags,
581                                   const struct iovec *iov,
582                                   int iovcnt,
583                                   NetPacketSent *sent_cb)
584 {
585     ssize_t ret = 0;
586     NetFilterState *nf = NULL;
587 
588     if (direction == NET_FILTER_DIRECTION_TX) {
589         QTAILQ_FOREACH(nf, &nc->filters, next) {
590             ret = qemu_netfilter_receive(nf, direction, sender, flags, iov,
591                                          iovcnt, sent_cb);
592             if (ret) {
593                 return ret;
594             }
595         }
596     } else {
597         QTAILQ_FOREACH_REVERSE(nf, &nc->filters, next) {
598             ret = qemu_netfilter_receive(nf, direction, sender, flags, iov,
599                                          iovcnt, sent_cb);
600             if (ret) {
601                 return ret;
602             }
603         }
604     }
605 
606     return ret;
607 }
608 
609 static ssize_t filter_receive(NetClientState *nc,
610                               NetFilterDirection direction,
611                               NetClientState *sender,
612                               unsigned flags,
613                               const uint8_t *data,
614                               size_t size,
615                               NetPacketSent *sent_cb)
616 {
617     struct iovec iov = {
618         .iov_base = (void *)data,
619         .iov_len = size
620     };
621 
622     return filter_receive_iov(nc, direction, sender, flags, &iov, 1, sent_cb);
623 }
624 
625 void qemu_purge_queued_packets(NetClientState *nc)
626 {
627     if (!nc->peer) {
628         return;
629     }
630 
631     qemu_net_queue_purge(nc->peer->incoming_queue, nc);
632 }
633 
634 void qemu_flush_or_purge_queued_packets(NetClientState *nc, bool purge)
635 {
636     nc->receive_disabled = 0;
637 
638     if (nc->peer && nc->peer->info->type == NET_CLIENT_DRIVER_HUBPORT) {
639         if (net_hub_flush(nc->peer)) {
640             qemu_notify_event();
641         }
642     }
643     if (qemu_net_queue_flush(nc->incoming_queue)) {
644         /* We emptied the queue successfully, signal to the IO thread to repoll
645          * the file descriptor (for tap, for example).
646          */
647         qemu_notify_event();
648     } else if (purge) {
649         /* Unable to empty the queue, purge remaining packets */
650         qemu_net_queue_purge(nc->incoming_queue, nc->peer);
651     }
652 }
653 
654 void qemu_flush_queued_packets(NetClientState *nc)
655 {
656     qemu_flush_or_purge_queued_packets(nc, false);
657 }
658 
659 static ssize_t qemu_send_packet_async_with_flags(NetClientState *sender,
660                                                  unsigned flags,
661                                                  const uint8_t *buf, int size,
662                                                  NetPacketSent *sent_cb)
663 {
664     NetQueue *queue;
665     int ret;
666 
667 #ifdef DEBUG_NET
668     printf("qemu_send_packet_async:\n");
669     qemu_hexdump(stdout, "net", buf, size);
670 #endif
671 
672     if (sender->link_down || !sender->peer) {
673         return size;
674     }
675 
676     /* Let filters handle the packet first */
677     ret = filter_receive(sender, NET_FILTER_DIRECTION_TX,
678                          sender, flags, buf, size, sent_cb);
679     if (ret) {
680         return ret;
681     }
682 
683     ret = filter_receive(sender->peer, NET_FILTER_DIRECTION_RX,
684                          sender, flags, buf, size, sent_cb);
685     if (ret) {
686         return ret;
687     }
688 
689     queue = sender->peer->incoming_queue;
690 
691     return qemu_net_queue_send(queue, sender, flags, buf, size, sent_cb);
692 }
693 
694 ssize_t qemu_send_packet_async(NetClientState *sender,
695                                const uint8_t *buf, int size,
696                                NetPacketSent *sent_cb)
697 {
698     return qemu_send_packet_async_with_flags(sender, QEMU_NET_PACKET_FLAG_NONE,
699                                              buf, size, sent_cb);
700 }
701 
702 ssize_t qemu_send_packet(NetClientState *nc, const uint8_t *buf, int size)
703 {
704     return qemu_send_packet_async(nc, buf, size, NULL);
705 }
706 
707 ssize_t qemu_receive_packet(NetClientState *nc, const uint8_t *buf, int size)
708 {
709     if (!qemu_can_receive_packet(nc)) {
710         return 0;
711     }
712 
713     return qemu_net_queue_receive(nc->incoming_queue, buf, size);
714 }
715 
716 ssize_t qemu_receive_packet_iov(NetClientState *nc, const struct iovec *iov,
717                                 int iovcnt)
718 {
719     if (!qemu_can_receive_packet(nc)) {
720         return 0;
721     }
722 
723     return qemu_net_queue_receive_iov(nc->incoming_queue, iov, iovcnt);
724 }
725 
726 ssize_t qemu_send_packet_raw(NetClientState *nc, const uint8_t *buf, int size)
727 {
728     return qemu_send_packet_async_with_flags(nc, QEMU_NET_PACKET_FLAG_RAW,
729                                              buf, size, NULL);
730 }
731 
732 static ssize_t nc_sendv_compat(NetClientState *nc, const struct iovec *iov,
733                                int iovcnt, unsigned flags)
734 {
735     uint8_t *buf = NULL;
736     uint8_t *buffer;
737     size_t offset;
738     ssize_t ret;
739 
740     if (iovcnt == 1) {
741         buffer = iov[0].iov_base;
742         offset = iov[0].iov_len;
743     } else {
744         offset = iov_size(iov, iovcnt);
745         if (offset > NET_BUFSIZE) {
746             return -1;
747         }
748         buf = g_malloc(offset);
749         buffer = buf;
750         offset = iov_to_buf(iov, iovcnt, 0, buf, offset);
751     }
752 
753     if (flags & QEMU_NET_PACKET_FLAG_RAW && nc->info->receive_raw) {
754         ret = nc->info->receive_raw(nc, buffer, offset);
755     } else {
756         ret = nc->info->receive(nc, buffer, offset);
757     }
758 
759     g_free(buf);
760     return ret;
761 }
762 
763 static ssize_t qemu_deliver_packet_iov(NetClientState *sender,
764                                        unsigned flags,
765                                        const struct iovec *iov,
766                                        int iovcnt,
767                                        void *opaque)
768 {
769     NetClientState *nc = opaque;
770     int ret;
771 
772 
773     if (nc->link_down) {
774         return iov_size(iov, iovcnt);
775     }
776 
777     if (nc->receive_disabled) {
778         return 0;
779     }
780 
781     if (nc->info->receive_iov && !(flags & QEMU_NET_PACKET_FLAG_RAW)) {
782         ret = nc->info->receive_iov(nc, iov, iovcnt);
783     } else {
784         ret = nc_sendv_compat(nc, iov, iovcnt, flags);
785     }
786 
787     if (ret == 0) {
788         nc->receive_disabled = 1;
789     }
790 
791     return ret;
792 }
793 
794 ssize_t qemu_sendv_packet_async(NetClientState *sender,
795                                 const struct iovec *iov, int iovcnt,
796                                 NetPacketSent *sent_cb)
797 {
798     NetQueue *queue;
799     size_t size = iov_size(iov, iovcnt);
800     int ret;
801 
802     if (size > NET_BUFSIZE) {
803         return size;
804     }
805 
806     if (sender->link_down || !sender->peer) {
807         return size;
808     }
809 
810     /* Let filters handle the packet first */
811     ret = filter_receive_iov(sender, NET_FILTER_DIRECTION_TX, sender,
812                              QEMU_NET_PACKET_FLAG_NONE, iov, iovcnt, sent_cb);
813     if (ret) {
814         return ret;
815     }
816 
817     ret = filter_receive_iov(sender->peer, NET_FILTER_DIRECTION_RX, sender,
818                              QEMU_NET_PACKET_FLAG_NONE, iov, iovcnt, sent_cb);
819     if (ret) {
820         return ret;
821     }
822 
823     queue = sender->peer->incoming_queue;
824 
825     return qemu_net_queue_send_iov(queue, sender,
826                                    QEMU_NET_PACKET_FLAG_NONE,
827                                    iov, iovcnt, sent_cb);
828 }
829 
830 ssize_t
831 qemu_sendv_packet(NetClientState *nc, const struct iovec *iov, int iovcnt)
832 {
833     return qemu_sendv_packet_async(nc, iov, iovcnt, NULL);
834 }
835 
836 NetClientState *qemu_find_netdev(const char *id)
837 {
838     NetClientState *nc;
839 
840     QTAILQ_FOREACH(nc, &net_clients, next) {
841         if (nc->info->type == NET_CLIENT_DRIVER_NIC)
842             continue;
843         if (!strcmp(nc->name, id)) {
844             return nc;
845         }
846     }
847 
848     return NULL;
849 }
850 
851 int qemu_find_net_clients_except(const char *id, NetClientState **ncs,
852                                  NetClientDriver type, int max)
853 {
854     NetClientState *nc;
855     int ret = 0;
856 
857     QTAILQ_FOREACH(nc, &net_clients, next) {
858         if (nc->info->type == type) {
859             continue;
860         }
861         if (!id || !strcmp(nc->name, id)) {
862             if (ret < max) {
863                 ncs[ret] = nc;
864             }
865             ret++;
866         }
867     }
868 
869     return ret;
870 }
871 
872 static int nic_get_free_idx(void)
873 {
874     int index;
875 
876     for (index = 0; index < MAX_NICS; index++)
877         if (!nd_table[index].used)
878             return index;
879     return -1;
880 }
881 
882 int qemu_show_nic_models(const char *arg, const char *const *models)
883 {
884     int i;
885 
886     if (!arg || !is_help_option(arg)) {
887         return 0;
888     }
889 
890     printf("Supported NIC models:\n");
891     for (i = 0 ; models[i]; i++) {
892         printf("%s\n", models[i]);
893     }
894     return 1;
895 }
896 
897 void qemu_check_nic_model(NICInfo *nd, const char *model)
898 {
899     const char *models[2];
900 
901     models[0] = model;
902     models[1] = NULL;
903 
904     if (qemu_show_nic_models(nd->model, models))
905         exit(0);
906     if (qemu_find_nic_model(nd, models, model) < 0)
907         exit(1);
908 }
909 
910 int qemu_find_nic_model(NICInfo *nd, const char * const *models,
911                         const char *default_model)
912 {
913     int i;
914 
915     if (!nd->model)
916         nd->model = g_strdup(default_model);
917 
918     for (i = 0 ; models[i]; i++) {
919         if (strcmp(nd->model, models[i]) == 0)
920             return i;
921     }
922 
923     error_report("Unsupported NIC model: %s", nd->model);
924     return -1;
925 }
926 
927 static int net_init_nic(const Netdev *netdev, const char *name,
928                         NetClientState *peer, Error **errp)
929 {
930     int idx;
931     NICInfo *nd;
932     const NetLegacyNicOptions *nic;
933 
934     assert(netdev->type == NET_CLIENT_DRIVER_NIC);
935     nic = &netdev->u.nic;
936 
937     idx = nic_get_free_idx();
938     if (idx == -1 || nb_nics >= MAX_NICS) {
939         error_setg(errp, "too many NICs");
940         return -1;
941     }
942 
943     nd = &nd_table[idx];
944 
945     memset(nd, 0, sizeof(*nd));
946 
947     if (nic->has_netdev) {
948         nd->netdev = qemu_find_netdev(nic->netdev);
949         if (!nd->netdev) {
950             error_setg(errp, "netdev '%s' not found", nic->netdev);
951             return -1;
952         }
953     } else {
954         assert(peer);
955         nd->netdev = peer;
956     }
957     nd->name = g_strdup(name);
958     if (nic->has_model) {
959         nd->model = g_strdup(nic->model);
960     }
961     if (nic->has_addr) {
962         nd->devaddr = g_strdup(nic->addr);
963     }
964 
965     if (nic->has_macaddr &&
966         net_parse_macaddr(nd->macaddr.a, nic->macaddr) < 0) {
967         error_setg(errp, "invalid syntax for ethernet address");
968         return -1;
969     }
970     if (nic->has_macaddr &&
971         is_multicast_ether_addr(nd->macaddr.a)) {
972         error_setg(errp,
973                    "NIC cannot have multicast MAC address (odd 1st byte)");
974         return -1;
975     }
976     qemu_macaddr_default_if_unset(&nd->macaddr);
977 
978     if (nic->has_vectors) {
979         if (nic->vectors > 0x7ffffff) {
980             error_setg(errp, "invalid # of vectors: %"PRIu32, nic->vectors);
981             return -1;
982         }
983         nd->nvectors = nic->vectors;
984     } else {
985         nd->nvectors = DEV_NVECTORS_UNSPECIFIED;
986     }
987 
988     nd->used = 1;
989     nb_nics++;
990 
991     return idx;
992 }
993 
994 
995 static int (* const net_client_init_fun[NET_CLIENT_DRIVER__MAX])(
996     const Netdev *netdev,
997     const char *name,
998     NetClientState *peer, Error **errp) = {
999         [NET_CLIENT_DRIVER_NIC]       = net_init_nic,
1000 #ifdef CONFIG_SLIRP
1001         [NET_CLIENT_DRIVER_USER]      = net_init_slirp,
1002 #endif
1003         [NET_CLIENT_DRIVER_TAP]       = net_init_tap,
1004         [NET_CLIENT_DRIVER_SOCKET]    = net_init_socket,
1005 #ifdef CONFIG_VDE
1006         [NET_CLIENT_DRIVER_VDE]       = net_init_vde,
1007 #endif
1008 #ifdef CONFIG_NETMAP
1009         [NET_CLIENT_DRIVER_NETMAP]    = net_init_netmap,
1010 #endif
1011 #ifdef CONFIG_NET_BRIDGE
1012         [NET_CLIENT_DRIVER_BRIDGE]    = net_init_bridge,
1013 #endif
1014         [NET_CLIENT_DRIVER_HUBPORT]   = net_init_hubport,
1015 #ifdef CONFIG_VHOST_NET_USER
1016         [NET_CLIENT_DRIVER_VHOST_USER] = net_init_vhost_user,
1017 #endif
1018 #ifdef CONFIG_VHOST_NET_VDPA
1019         [NET_CLIENT_DRIVER_VHOST_VDPA] = net_init_vhost_vdpa,
1020 #endif
1021 #ifdef CONFIG_L2TPV3
1022         [NET_CLIENT_DRIVER_L2TPV3]    = net_init_l2tpv3,
1023 #endif
1024 };
1025 
1026 
1027 static int net_client_init1(const Netdev *netdev, bool is_netdev, Error **errp)
1028 {
1029     NetClientState *peer = NULL;
1030     NetClientState *nc;
1031 
1032     if (is_netdev) {
1033         if (netdev->type == NET_CLIENT_DRIVER_NIC ||
1034             !net_client_init_fun[netdev->type]) {
1035             error_setg(errp, QERR_INVALID_PARAMETER_VALUE, "type",
1036                        "a netdev backend type");
1037             return -1;
1038         }
1039     } else {
1040         if (netdev->type == NET_CLIENT_DRIVER_NONE) {
1041             return 0; /* nothing to do */
1042         }
1043         if (netdev->type == NET_CLIENT_DRIVER_HUBPORT ||
1044             !net_client_init_fun[netdev->type]) {
1045             error_setg(errp, QERR_INVALID_PARAMETER_VALUE, "type",
1046                        "a net backend type (maybe it is not compiled "
1047                        "into this binary)");
1048             return -1;
1049         }
1050 
1051         /* Do not add to a hub if it's a nic with a netdev= parameter. */
1052         if (netdev->type != NET_CLIENT_DRIVER_NIC ||
1053             !netdev->u.nic.has_netdev) {
1054             peer = net_hub_add_port(0, NULL, NULL);
1055         }
1056     }
1057 
1058     nc = qemu_find_netdev(netdev->id);
1059     if (nc) {
1060         error_setg(errp, "Duplicate ID '%s'", netdev->id);
1061         return -1;
1062     }
1063 
1064     if (net_client_init_fun[netdev->type](netdev, netdev->id, peer, errp) < 0) {
1065         /* FIXME drop when all init functions store an Error */
1066         if (errp && !*errp) {
1067             error_setg(errp, "Device '%s' could not be initialized",
1068                        NetClientDriver_str(netdev->type));
1069         }
1070         return -1;
1071     }
1072 
1073     if (is_netdev) {
1074         nc = qemu_find_netdev(netdev->id);
1075         assert(nc);
1076         nc->is_netdev = true;
1077     }
1078 
1079     return 0;
1080 }
1081 
1082 void show_netdevs(void)
1083 {
1084     int idx;
1085     const char *available_netdevs[] = {
1086         "socket",
1087         "hubport",
1088         "tap",
1089 #ifdef CONFIG_SLIRP
1090         "user",
1091 #endif
1092 #ifdef CONFIG_L2TPV3
1093         "l2tpv3",
1094 #endif
1095 #ifdef CONFIG_VDE
1096         "vde",
1097 #endif
1098 #ifdef CONFIG_NET_BRIDGE
1099         "bridge",
1100 #endif
1101 #ifdef CONFIG_NETMAP
1102         "netmap",
1103 #endif
1104 #ifdef CONFIG_POSIX
1105         "vhost-user",
1106 #endif
1107 #ifdef CONFIG_VHOST_VDPA
1108         "vhost-vdpa",
1109 #endif
1110     };
1111 
1112     qemu_printf("Available netdev backend types:\n");
1113     for (idx = 0; idx < ARRAY_SIZE(available_netdevs); idx++) {
1114         qemu_printf("%s\n", available_netdevs[idx]);
1115     }
1116 }
1117 
1118 static int net_client_init(QemuOpts *opts, bool is_netdev, Error **errp)
1119 {
1120     gchar **substrings = NULL;
1121     Netdev *object = NULL;
1122     int ret = -1;
1123     Visitor *v = opts_visitor_new(opts);
1124 
1125     /* Parse convenience option format ip6-net=fec0::0[/64] */
1126     const char *ip6_net = qemu_opt_get(opts, "ipv6-net");
1127 
1128     if (ip6_net) {
1129         char *prefix_addr;
1130         unsigned long prefix_len = 64; /* Default 64bit prefix length. */
1131 
1132         substrings = g_strsplit(ip6_net, "/", 2);
1133         if (!substrings || !substrings[0]) {
1134             error_setg(errp, QERR_INVALID_PARAMETER_VALUE, "ipv6-net",
1135                        "a valid IPv6 prefix");
1136             goto out;
1137         }
1138 
1139         prefix_addr = substrings[0];
1140 
1141         /* Handle user-specified prefix length. */
1142         if (substrings[1] &&
1143             qemu_strtoul(substrings[1], NULL, 10, &prefix_len))
1144         {
1145             error_setg(errp, QERR_INVALID_PARAMETER_VALUE,
1146                        "ipv6-prefixlen", "a number");
1147             goto out;
1148         }
1149 
1150         qemu_opt_set(opts, "ipv6-prefix", prefix_addr, &error_abort);
1151         qemu_opt_set_number(opts, "ipv6-prefixlen", prefix_len,
1152                             &error_abort);
1153         qemu_opt_unset(opts, "ipv6-net");
1154     }
1155 
1156     /* Create an ID for -net if the user did not specify one */
1157     if (!is_netdev && !qemu_opts_id(opts)) {
1158         qemu_opts_set_id(opts, id_generate(ID_NET));
1159     }
1160 
1161     if (visit_type_Netdev(v, NULL, &object, errp)) {
1162         ret = net_client_init1(object, is_netdev, errp);
1163     }
1164 
1165     qapi_free_Netdev(object);
1166 
1167 out:
1168     g_strfreev(substrings);
1169     visit_free(v);
1170     return ret;
1171 }
1172 
1173 void netdev_add(QemuOpts *opts, Error **errp)
1174 {
1175     net_client_init(opts, true, errp);
1176 }
1177 
1178 void qmp_netdev_add(Netdev *netdev, Error **errp)
1179 {
1180     if (!id_wellformed(netdev->id)) {
1181         error_setg(errp, QERR_INVALID_PARAMETER_VALUE, "id", "an identifier");
1182         return;
1183     }
1184 
1185     net_client_init1(netdev, true, errp);
1186 }
1187 
1188 void qmp_netdev_del(const char *id, Error **errp)
1189 {
1190     NetClientState *nc;
1191     QemuOpts *opts;
1192 
1193     nc = qemu_find_netdev(id);
1194     if (!nc) {
1195         error_set(errp, ERROR_CLASS_DEVICE_NOT_FOUND,
1196                   "Device '%s' not found", id);
1197         return;
1198     }
1199 
1200     if (!nc->is_netdev) {
1201         error_setg(errp, "Device '%s' is not a netdev", id);
1202         return;
1203     }
1204 
1205     qemu_del_net_client(nc);
1206 
1207     /*
1208      * Wart: we need to delete the QemuOpts associated with netdevs
1209      * created via CLI or HMP, to avoid bogus "Duplicate ID" errors in
1210      * HMP netdev_add.
1211      */
1212     opts = qemu_opts_find(qemu_find_opts("netdev"), id);
1213     if (opts) {
1214         qemu_opts_del(opts);
1215     }
1216 }
1217 
1218 static void netfilter_print_info(Monitor *mon, NetFilterState *nf)
1219 {
1220     char *str;
1221     ObjectProperty *prop;
1222     ObjectPropertyIterator iter;
1223     Visitor *v;
1224 
1225     /* generate info str */
1226     object_property_iter_init(&iter, OBJECT(nf));
1227     while ((prop = object_property_iter_next(&iter))) {
1228         if (!strcmp(prop->name, "type")) {
1229             continue;
1230         }
1231         v = string_output_visitor_new(false, &str);
1232         object_property_get(OBJECT(nf), prop->name, v, NULL);
1233         visit_complete(v, &str);
1234         visit_free(v);
1235         monitor_printf(mon, ",%s=%s", prop->name, str);
1236         g_free(str);
1237     }
1238     monitor_printf(mon, "\n");
1239 }
1240 
1241 void print_net_client(Monitor *mon, NetClientState *nc)
1242 {
1243     NetFilterState *nf;
1244 
1245     monitor_printf(mon, "%s: index=%d,type=%s,%s\n", nc->name,
1246                    nc->queue_index,
1247                    NetClientDriver_str(nc->info->type),
1248                    nc->info_str);
1249     if (!QTAILQ_EMPTY(&nc->filters)) {
1250         monitor_printf(mon, "filters:\n");
1251     }
1252     QTAILQ_FOREACH(nf, &nc->filters, next) {
1253         monitor_printf(mon, "  - %s: type=%s",
1254                        object_get_canonical_path_component(OBJECT(nf)),
1255                        object_get_typename(OBJECT(nf)));
1256         netfilter_print_info(mon, nf);
1257     }
1258 }
1259 
1260 RxFilterInfoList *qmp_query_rx_filter(bool has_name, const char *name,
1261                                       Error **errp)
1262 {
1263     NetClientState *nc;
1264     RxFilterInfoList *filter_list = NULL, **tail = &filter_list;
1265 
1266     QTAILQ_FOREACH(nc, &net_clients, next) {
1267         RxFilterInfo *info;
1268 
1269         if (has_name && strcmp(nc->name, name) != 0) {
1270             continue;
1271         }
1272 
1273         /* only query rx-filter information of NIC */
1274         if (nc->info->type != NET_CLIENT_DRIVER_NIC) {
1275             if (has_name) {
1276                 error_setg(errp, "net client(%s) isn't a NIC", name);
1277                 assert(!filter_list);
1278                 return NULL;
1279             }
1280             continue;
1281         }
1282 
1283         /* only query information on queue 0 since the info is per nic,
1284          * not per queue
1285          */
1286         if (nc->queue_index != 0)
1287             continue;
1288 
1289         if (nc->info->query_rx_filter) {
1290             info = nc->info->query_rx_filter(nc);
1291             QAPI_LIST_APPEND(tail, info);
1292         } else if (has_name) {
1293             error_setg(errp, "net client(%s) doesn't support"
1294                        " rx-filter querying", name);
1295             assert(!filter_list);
1296             return NULL;
1297         }
1298 
1299         if (has_name) {
1300             break;
1301         }
1302     }
1303 
1304     if (filter_list == NULL && has_name) {
1305         error_setg(errp, "invalid net client name: %s", name);
1306     }
1307 
1308     return filter_list;
1309 }
1310 
1311 void hmp_info_network(Monitor *mon, const QDict *qdict)
1312 {
1313     NetClientState *nc, *peer;
1314     NetClientDriver type;
1315 
1316     net_hub_info(mon);
1317 
1318     QTAILQ_FOREACH(nc, &net_clients, next) {
1319         peer = nc->peer;
1320         type = nc->info->type;
1321 
1322         /* Skip if already printed in hub info */
1323         if (net_hub_id_for_client(nc, NULL) == 0) {
1324             continue;
1325         }
1326 
1327         if (!peer || type == NET_CLIENT_DRIVER_NIC) {
1328             print_net_client(mon, nc);
1329         } /* else it's a netdev connected to a NIC, printed with the NIC */
1330         if (peer && type == NET_CLIENT_DRIVER_NIC) {
1331             monitor_printf(mon, " \\ ");
1332             print_net_client(mon, peer);
1333         }
1334     }
1335 }
1336 
1337 void colo_notify_filters_event(int event, Error **errp)
1338 {
1339     NetClientState *nc;
1340     NetFilterState *nf;
1341     NetFilterClass *nfc = NULL;
1342     Error *local_err = NULL;
1343 
1344     QTAILQ_FOREACH(nc, &net_clients, next) {
1345         QTAILQ_FOREACH(nf, &nc->filters, next) {
1346             nfc = NETFILTER_GET_CLASS(OBJECT(nf));
1347             nfc->handle_event(nf, event, &local_err);
1348             if (local_err) {
1349                 error_propagate(errp, local_err);
1350                 return;
1351             }
1352         }
1353     }
1354 }
1355 
1356 void qmp_set_link(const char *name, bool up, Error **errp)
1357 {
1358     NetClientState *ncs[MAX_QUEUE_NUM];
1359     NetClientState *nc;
1360     int queues, i;
1361 
1362     queues = qemu_find_net_clients_except(name, ncs,
1363                                           NET_CLIENT_DRIVER__MAX,
1364                                           MAX_QUEUE_NUM);
1365 
1366     if (queues == 0) {
1367         error_set(errp, ERROR_CLASS_DEVICE_NOT_FOUND,
1368                   "Device '%s' not found", name);
1369         return;
1370     }
1371     nc = ncs[0];
1372 
1373     for (i = 0; i < queues; i++) {
1374         ncs[i]->link_down = !up;
1375     }
1376 
1377     if (nc->info->link_status_changed) {
1378         nc->info->link_status_changed(nc);
1379     }
1380 
1381     if (nc->peer) {
1382         /* Change peer link only if the peer is NIC and then notify peer.
1383          * If the peer is a HUBPORT or a backend, we do not change the
1384          * link status.
1385          *
1386          * This behavior is compatible with qemu hubs where there could be
1387          * multiple clients that can still communicate with each other in
1388          * disconnected mode. For now maintain this compatibility.
1389          */
1390         if (nc->peer->info->type == NET_CLIENT_DRIVER_NIC) {
1391             for (i = 0; i < queues; i++) {
1392                 ncs[i]->peer->link_down = !up;
1393             }
1394         }
1395         if (nc->peer->info->link_status_changed) {
1396             nc->peer->info->link_status_changed(nc->peer);
1397         }
1398     }
1399 }
1400 
1401 static void net_vm_change_state_handler(void *opaque, bool running,
1402                                         RunState state)
1403 {
1404     NetClientState *nc;
1405     NetClientState *tmp;
1406 
1407     QTAILQ_FOREACH_SAFE(nc, &net_clients, next, tmp) {
1408         if (running) {
1409             /* Flush queued packets and wake up backends. */
1410             if (nc->peer && qemu_can_send_packet(nc)) {
1411                 qemu_flush_queued_packets(nc->peer);
1412             }
1413         } else {
1414             /* Complete all queued packets, to guarantee we don't modify
1415              * state later when VM is not running.
1416              */
1417             qemu_flush_or_purge_queued_packets(nc, true);
1418         }
1419     }
1420 }
1421 
1422 void net_cleanup(void)
1423 {
1424     NetClientState *nc;
1425 
1426     /*cleanup colo compare module for COLO*/
1427     colo_compare_cleanup();
1428 
1429     /* We may del multiple entries during qemu_del_net_client(),
1430      * so QTAILQ_FOREACH_SAFE() is also not safe here.
1431      */
1432     while (!QTAILQ_EMPTY(&net_clients)) {
1433         nc = QTAILQ_FIRST(&net_clients);
1434         if (nc->info->type == NET_CLIENT_DRIVER_NIC) {
1435             qemu_del_nic(qemu_get_nic(nc));
1436         } else {
1437             qemu_del_net_client(nc);
1438         }
1439     }
1440 
1441     qemu_del_vm_change_state_handler(net_change_state_entry);
1442 }
1443 
1444 void net_check_clients(void)
1445 {
1446     NetClientState *nc;
1447     int i;
1448 
1449     net_hub_check_clients();
1450 
1451     QTAILQ_FOREACH(nc, &net_clients, next) {
1452         if (!nc->peer) {
1453             warn_report("%s %s has no peer",
1454                         nc->info->type == NET_CLIENT_DRIVER_NIC
1455                         ? "nic" : "netdev",
1456                         nc->name);
1457         }
1458     }
1459 
1460     /* Check that all NICs requested via -net nic actually got created.
1461      * NICs created via -device don't need to be checked here because
1462      * they are always instantiated.
1463      */
1464     for (i = 0; i < MAX_NICS; i++) {
1465         NICInfo *nd = &nd_table[i];
1466         if (nd->used && !nd->instantiated) {
1467             warn_report("requested NIC (%s, model %s) "
1468                         "was not created (not supported by this machine?)",
1469                         nd->name ? nd->name : "anonymous",
1470                         nd->model ? nd->model : "unspecified");
1471         }
1472     }
1473 }
1474 
1475 static int net_init_client(void *dummy, QemuOpts *opts, Error **errp)
1476 {
1477     return net_client_init(opts, false, errp);
1478 }
1479 
1480 static int net_init_netdev(void *dummy, QemuOpts *opts, Error **errp)
1481 {
1482     const char *type = qemu_opt_get(opts, "type");
1483 
1484     if (type && is_help_option(type)) {
1485         show_netdevs();
1486         exit(0);
1487     }
1488     return net_client_init(opts, true, errp);
1489 }
1490 
1491 /* For the convenience "--nic" parameter */
1492 static int net_param_nic(void *dummy, QemuOpts *opts, Error **errp)
1493 {
1494     char *mac, *nd_id;
1495     int idx, ret;
1496     NICInfo *ni;
1497     const char *type;
1498 
1499     type = qemu_opt_get(opts, "type");
1500     if (type && g_str_equal(type, "none")) {
1501         return 0;    /* Nothing to do, default_net is cleared in vl.c */
1502     }
1503 
1504     idx = nic_get_free_idx();
1505     if (idx == -1 || nb_nics >= MAX_NICS) {
1506         error_setg(errp, "no more on-board/default NIC slots available");
1507         return -1;
1508     }
1509 
1510     if (!type) {
1511         qemu_opt_set(opts, "type", "user", &error_abort);
1512     }
1513 
1514     ni = &nd_table[idx];
1515     memset(ni, 0, sizeof(*ni));
1516     ni->model = qemu_opt_get_del(opts, "model");
1517 
1518     /* Create an ID if the user did not specify one */
1519     nd_id = g_strdup(qemu_opts_id(opts));
1520     if (!nd_id) {
1521         nd_id = id_generate(ID_NET);
1522         qemu_opts_set_id(opts, nd_id);
1523     }
1524 
1525     /* Handle MAC address */
1526     mac = qemu_opt_get_del(opts, "mac");
1527     if (mac) {
1528         ret = net_parse_macaddr(ni->macaddr.a, mac);
1529         g_free(mac);
1530         if (ret) {
1531             error_setg(errp, "invalid syntax for ethernet address");
1532             goto out;
1533         }
1534         if (is_multicast_ether_addr(ni->macaddr.a)) {
1535             error_setg(errp, "NIC cannot have multicast MAC address");
1536             ret = -1;
1537             goto out;
1538         }
1539     }
1540     qemu_macaddr_default_if_unset(&ni->macaddr);
1541 
1542     ret = net_client_init(opts, true, errp);
1543     if (ret == 0) {
1544         ni->netdev = qemu_find_netdev(nd_id);
1545         ni->used = true;
1546         nb_nics++;
1547     }
1548 
1549 out:
1550     g_free(nd_id);
1551     return ret;
1552 }
1553 
1554 int net_init_clients(Error **errp)
1555 {
1556     net_change_state_entry =
1557         qemu_add_vm_change_state_handler(net_vm_change_state_handler, NULL);
1558 
1559     QTAILQ_INIT(&net_clients);
1560 
1561     if (qemu_opts_foreach(qemu_find_opts("netdev"),
1562                           net_init_netdev, NULL, errp)) {
1563         return -1;
1564     }
1565 
1566     if (qemu_opts_foreach(qemu_find_opts("nic"), net_param_nic, NULL, errp)) {
1567         return -1;
1568     }
1569 
1570     if (qemu_opts_foreach(qemu_find_opts("net"), net_init_client, NULL, errp)) {
1571         return -1;
1572     }
1573 
1574     return 0;
1575 }
1576 
1577 int net_client_parse(QemuOptsList *opts_list, const char *optarg)
1578 {
1579     if (!qemu_opts_parse_noisily(opts_list, optarg, true)) {
1580         return -1;
1581     }
1582 
1583     return 0;
1584 }
1585 
1586 /* From FreeBSD */
1587 /* XXX: optimize */
1588 uint32_t net_crc32(const uint8_t *p, int len)
1589 {
1590     uint32_t crc;
1591     int carry, i, j;
1592     uint8_t b;
1593 
1594     crc = 0xffffffff;
1595     for (i = 0; i < len; i++) {
1596         b = *p++;
1597         for (j = 0; j < 8; j++) {
1598             carry = ((crc & 0x80000000L) ? 1 : 0) ^ (b & 0x01);
1599             crc <<= 1;
1600             b >>= 1;
1601             if (carry) {
1602                 crc = ((crc ^ POLYNOMIAL_BE) | carry);
1603             }
1604         }
1605     }
1606 
1607     return crc;
1608 }
1609 
1610 uint32_t net_crc32_le(const uint8_t *p, int len)
1611 {
1612     uint32_t crc;
1613     int carry, i, j;
1614     uint8_t b;
1615 
1616     crc = 0xffffffff;
1617     for (i = 0; i < len; i++) {
1618         b = *p++;
1619         for (j = 0; j < 8; j++) {
1620             carry = (crc & 0x1) ^ (b & 0x01);
1621             crc >>= 1;
1622             b >>= 1;
1623             if (carry) {
1624                 crc ^= POLYNOMIAL_LE;
1625             }
1626         }
1627     }
1628 
1629     return crc;
1630 }
1631 
1632 QemuOptsList qemu_netdev_opts = {
1633     .name = "netdev",
1634     .implied_opt_name = "type",
1635     .head = QTAILQ_HEAD_INITIALIZER(qemu_netdev_opts.head),
1636     .desc = {
1637         /*
1638          * no elements => accept any params
1639          * validation will happen later
1640          */
1641         { /* end of list */ }
1642     },
1643 };
1644 
1645 QemuOptsList qemu_nic_opts = {
1646     .name = "nic",
1647     .implied_opt_name = "type",
1648     .head = QTAILQ_HEAD_INITIALIZER(qemu_nic_opts.head),
1649     .desc = {
1650         /*
1651          * no elements => accept any params
1652          * validation will happen later
1653          */
1654         { /* end of list */ }
1655     },
1656 };
1657 
1658 QemuOptsList qemu_net_opts = {
1659     .name = "net",
1660     .implied_opt_name = "type",
1661     .head = QTAILQ_HEAD_INITIALIZER(qemu_net_opts.head),
1662     .desc = {
1663         /*
1664          * no elements => accept any params
1665          * validation will happen later
1666          */
1667         { /* end of list */ }
1668     },
1669 };
1670 
1671 void net_socket_rs_init(SocketReadState *rs,
1672                         SocketReadStateFinalize *finalize,
1673                         bool vnet_hdr)
1674 {
1675     rs->state = 0;
1676     rs->vnet_hdr = vnet_hdr;
1677     rs->index = 0;
1678     rs->packet_len = 0;
1679     rs->vnet_hdr_len = 0;
1680     memset(rs->buf, 0, sizeof(rs->buf));
1681     rs->finalize = finalize;
1682 }
1683 
1684 /*
1685  * Returns
1686  * 0: success
1687  * -1: error occurs
1688  */
1689 int net_fill_rstate(SocketReadState *rs, const uint8_t *buf, int size)
1690 {
1691     unsigned int l;
1692 
1693     while (size > 0) {
1694         /* Reassemble a packet from the network.
1695          * 0 = getting length.
1696          * 1 = getting vnet header length.
1697          * 2 = getting data.
1698          */
1699         switch (rs->state) {
1700         case 0:
1701             l = 4 - rs->index;
1702             if (l > size) {
1703                 l = size;
1704             }
1705             memcpy(rs->buf + rs->index, buf, l);
1706             buf += l;
1707             size -= l;
1708             rs->index += l;
1709             if (rs->index == 4) {
1710                 /* got length */
1711                 rs->packet_len = ntohl(*(uint32_t *)rs->buf);
1712                 rs->index = 0;
1713                 if (rs->vnet_hdr) {
1714                     rs->state = 1;
1715                 } else {
1716                     rs->state = 2;
1717                     rs->vnet_hdr_len = 0;
1718                 }
1719             }
1720             break;
1721         case 1:
1722             l = 4 - rs->index;
1723             if (l > size) {
1724                 l = size;
1725             }
1726             memcpy(rs->buf + rs->index, buf, l);
1727             buf += l;
1728             size -= l;
1729             rs->index += l;
1730             if (rs->index == 4) {
1731                 /* got vnet header length */
1732                 rs->vnet_hdr_len = ntohl(*(uint32_t *)rs->buf);
1733                 rs->index = 0;
1734                 rs->state = 2;
1735             }
1736             break;
1737         case 2:
1738             l = rs->packet_len - rs->index;
1739             if (l > size) {
1740                 l = size;
1741             }
1742             if (rs->index + l <= sizeof(rs->buf)) {
1743                 memcpy(rs->buf + rs->index, buf, l);
1744             } else {
1745                 fprintf(stderr, "serious error: oversized packet received,"
1746                     "connection terminated.\n");
1747                 rs->index = rs->state = 0;
1748                 return -1;
1749             }
1750 
1751             rs->index += l;
1752             buf += l;
1753             size -= l;
1754             if (rs->index >= rs->packet_len) {
1755                 rs->index = 0;
1756                 rs->state = 0;
1757                 assert(rs->finalize);
1758                 rs->finalize(rs);
1759             }
1760             break;
1761         }
1762     }
1763 
1764     assert(size == 0);
1765     return 0;
1766 }
1767