xref: /openbmc/qemu/net/net.c (revision 59b5437e)
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 
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     substrings = g_strsplit(str, ":", 2);
79     if (!substrings || !substrings[0] || !substrings[1]) {
80         error_setg(errp, "host address '%s' doesn't contain ':' "
81                    "separating host from port", str);
82         ret = -1;
83         goto out;
84     }
85 
86     addr = substrings[0];
87     p = substrings[1];
88 
89     saddr->sin_family = AF_INET;
90     if (addr[0] == '\0') {
91         saddr->sin_addr.s_addr = 0;
92     } else {
93         if (qemu_isdigit(addr[0])) {
94             if (!inet_aton(addr, &saddr->sin_addr)) {
95                 error_setg(errp, "host address '%s' is not a valid "
96                            "IPv4 address", addr);
97                 ret = -1;
98                 goto out;
99             }
100         } else {
101             he = gethostbyname(addr);
102             if (he == NULL) {
103                 error_setg(errp, "can't resolve host address '%s'", addr);
104                 ret = -1;
105                 goto out;
106             }
107             saddr->sin_addr = *(struct in_addr *)he->h_addr;
108         }
109     }
110     port = strtol(p, (char **)&r, 0);
111     if (r == p) {
112         error_setg(errp, "port number '%s' is invalid", p);
113         ret = -1;
114         goto out;
115     }
116     saddr->sin_port = htons(port);
117 
118 out:
119     g_strfreev(substrings);
120     return ret;
121 }
122 
123 char *qemu_mac_strdup_printf(const uint8_t *macaddr)
124 {
125     return g_strdup_printf("%.2x:%.2x:%.2x:%.2x:%.2x:%.2x",
126                            macaddr[0], macaddr[1], macaddr[2],
127                            macaddr[3], macaddr[4], macaddr[5]);
128 }
129 
130 void qemu_format_nic_info_str(NetClientState *nc, uint8_t macaddr[6])
131 {
132     g_free(nc->info_str);
133     nc->info_str = g_strdup_printf(
134         "model=%s,macaddr=%02x:%02x:%02x:%02x:%02x:%02x",
135         nc->model,
136         macaddr[0], macaddr[1], macaddr[2],
137         macaddr[3], macaddr[4], macaddr[5]);
138 }
139 
140 static int mac_table[256] = {0};
141 
142 static void qemu_macaddr_set_used(MACAddr *macaddr)
143 {
144     int index;
145 
146     for (index = 0x56; index < 0xFF; index++) {
147         if (macaddr->a[5] == index) {
148             mac_table[index]++;
149         }
150     }
151 }
152 
153 static void qemu_macaddr_set_free(MACAddr *macaddr)
154 {
155     int index;
156     static const MACAddr base = { .a = { 0x52, 0x54, 0x00, 0x12, 0x34, 0 } };
157 
158     if (memcmp(macaddr->a, &base.a, (sizeof(base.a) - 1)) != 0) {
159         return;
160     }
161     for (index = 0x56; index < 0xFF; index++) {
162         if (macaddr->a[5] == index) {
163             mac_table[index]--;
164         }
165     }
166 }
167 
168 static int qemu_macaddr_get_free(void)
169 {
170     int index;
171 
172     for (index = 0x56; index < 0xFF; index++) {
173         if (mac_table[index] == 0) {
174             return index;
175         }
176     }
177 
178     return -1;
179 }
180 
181 void qemu_macaddr_default_if_unset(MACAddr *macaddr)
182 {
183     static const MACAddr zero = { .a = { 0,0,0,0,0,0 } };
184     static const MACAddr base = { .a = { 0x52, 0x54, 0x00, 0x12, 0x34, 0 } };
185 
186     if (memcmp(macaddr, &zero, sizeof(zero)) != 0) {
187         if (memcmp(macaddr->a, &base.a, (sizeof(base.a) - 1)) != 0) {
188             return;
189         } else {
190             qemu_macaddr_set_used(macaddr);
191             return;
192         }
193     }
194 
195     macaddr->a[0] = 0x52;
196     macaddr->a[1] = 0x54;
197     macaddr->a[2] = 0x00;
198     macaddr->a[3] = 0x12;
199     macaddr->a[4] = 0x34;
200     macaddr->a[5] = qemu_macaddr_get_free();
201     qemu_macaddr_set_used(macaddr);
202 }
203 
204 /**
205  * Generate a name for net client
206  *
207  * Only net clients created with the legacy -net option and NICs need this.
208  */
209 static char *assign_name(NetClientState *nc1, const char *model)
210 {
211     NetClientState *nc;
212     int id = 0;
213 
214     QTAILQ_FOREACH(nc, &net_clients, next) {
215         if (nc == nc1) {
216             continue;
217         }
218         if (strcmp(nc->model, model) == 0) {
219             id++;
220         }
221     }
222 
223     return g_strdup_printf("%s.%d", model, id);
224 }
225 
226 static void qemu_net_client_destructor(NetClientState *nc)
227 {
228     g_free(nc);
229 }
230 static ssize_t qemu_deliver_packet_iov(NetClientState *sender,
231                                        unsigned flags,
232                                        const struct iovec *iov,
233                                        int iovcnt,
234                                        void *opaque);
235 
236 static void qemu_net_client_setup(NetClientState *nc,
237                                   NetClientInfo *info,
238                                   NetClientState *peer,
239                                   const char *model,
240                                   const char *name,
241                                   NetClientDestructor *destructor)
242 {
243     nc->info = info;
244     nc->model = g_strdup(model);
245     if (name) {
246         nc->name = g_strdup(name);
247     } else {
248         nc->name = assign_name(nc, model);
249     }
250 
251     if (peer) {
252         assert(!peer->peer);
253         nc->peer = peer;
254         peer->peer = nc;
255     }
256     QTAILQ_INSERT_TAIL(&net_clients, nc, next);
257 
258     nc->incoming_queue = qemu_new_net_queue(qemu_deliver_packet_iov, nc);
259     nc->destructor = destructor;
260     QTAILQ_INIT(&nc->filters);
261 }
262 
263 NetClientState *qemu_new_net_client(NetClientInfo *info,
264                                     NetClientState *peer,
265                                     const char *model,
266                                     const char *name)
267 {
268     NetClientState *nc;
269 
270     assert(info->size >= sizeof(NetClientState));
271 
272     nc = g_malloc0(info->size);
273     qemu_net_client_setup(nc, info, peer, model, name,
274                           qemu_net_client_destructor);
275 
276     return nc;
277 }
278 
279 NICState *qemu_new_nic(NetClientInfo *info,
280                        NICConf *conf,
281                        const char *model,
282                        const char *name,
283                        void *opaque)
284 {
285     NetClientState **peers = conf->peers.ncs;
286     NICState *nic;
287     int i, queues = MAX(1, conf->peers.queues);
288 
289     assert(info->type == NET_CLIENT_DRIVER_NIC);
290     assert(info->size >= sizeof(NICState));
291 
292     nic = g_malloc0(info->size + sizeof(NetClientState) * queues);
293     nic->ncs = (void *)nic + info->size;
294     nic->conf = conf;
295     nic->opaque = opaque;
296 
297     for (i = 0; i < queues; i++) {
298         qemu_net_client_setup(&nic->ncs[i], info, peers[i], model, name,
299                               NULL);
300         nic->ncs[i].queue_index = i;
301     }
302 
303     return nic;
304 }
305 
306 NetClientState *qemu_get_subqueue(NICState *nic, int queue_index)
307 {
308     return nic->ncs + queue_index;
309 }
310 
311 NetClientState *qemu_get_queue(NICState *nic)
312 {
313     return qemu_get_subqueue(nic, 0);
314 }
315 
316 NICState *qemu_get_nic(NetClientState *nc)
317 {
318     NetClientState *nc0 = nc - nc->queue_index;
319 
320     return (NICState *)((void *)nc0 - nc->info->size);
321 }
322 
323 void *qemu_get_nic_opaque(NetClientState *nc)
324 {
325     NICState *nic = qemu_get_nic(nc);
326 
327     return nic->opaque;
328 }
329 
330 NetClientState *qemu_get_peer(NetClientState *nc, int queue_index)
331 {
332     assert(nc != NULL);
333     NetClientState *ncs = nc + queue_index;
334     return ncs->peer;
335 }
336 
337 static void qemu_cleanup_net_client(NetClientState *nc)
338 {
339     QTAILQ_REMOVE(&net_clients, nc, next);
340 
341     if (nc->info->cleanup) {
342         nc->info->cleanup(nc);
343     }
344 }
345 
346 static void qemu_free_net_client(NetClientState *nc)
347 {
348     if (nc->incoming_queue) {
349         qemu_del_net_queue(nc->incoming_queue);
350     }
351     if (nc->peer) {
352         nc->peer->peer = NULL;
353     }
354     g_free(nc->name);
355     g_free(nc->model);
356     g_free(nc->info_str);
357     qapi_free_NetdevInfo(nc->stored_config);
358     if (nc->destructor) {
359         nc->destructor(nc);
360     }
361 }
362 
363 void qemu_del_net_client(NetClientState *nc)
364 {
365     NetClientState *ncs[MAX_QUEUE_NUM];
366     int queues, i;
367     NetFilterState *nf, *next;
368 
369     assert(nc->info->type != NET_CLIENT_DRIVER_NIC);
370 
371     /* If the NetClientState belongs to a multiqueue backend, we will change all
372      * other NetClientStates also.
373      */
374     queues = qemu_find_net_clients_except(nc->name, ncs,
375                                           NET_CLIENT_DRIVER_NIC,
376                                           MAX_QUEUE_NUM);
377     assert(queues != 0);
378 
379     QTAILQ_FOREACH_SAFE(nf, &nc->filters, next, next) {
380         object_unparent(OBJECT(nf));
381     }
382 
383     /* If there is a peer NIC, delete and cleanup client, but do not free. */
384     if (nc->peer && nc->peer->info->type == NET_CLIENT_DRIVER_NIC) {
385         NICState *nic = qemu_get_nic(nc->peer);
386         if (nic->peer_deleted) {
387             return;
388         }
389         nic->peer_deleted = true;
390 
391         for (i = 0; i < queues; i++) {
392             ncs[i]->peer->link_down = true;
393         }
394 
395         if (nc->peer->info->link_status_changed) {
396             nc->peer->info->link_status_changed(nc->peer);
397         }
398 
399         for (i = 0; i < queues; i++) {
400             qemu_cleanup_net_client(ncs[i]);
401         }
402 
403         return;
404     }
405 
406     for (i = 0; i < queues; i++) {
407         qemu_cleanup_net_client(ncs[i]);
408         qemu_free_net_client(ncs[i]);
409     }
410 }
411 
412 void qemu_del_nic(NICState *nic)
413 {
414     int i, queues = MAX(nic->conf->peers.queues, 1);
415 
416     qemu_macaddr_set_free(&nic->conf->macaddr);
417 
418     for (i = 0; i < queues; i++) {
419         NetClientState *nc = qemu_get_subqueue(nic, i);
420         /* If this is a peer NIC and peer has already been deleted, free it now. */
421         if (nic->peer_deleted) {
422             qemu_free_net_client(nc->peer);
423         } else if (nc->peer) {
424             /* if there are RX packets pending, complete them */
425             qemu_purge_queued_packets(nc->peer);
426         }
427     }
428 
429     for (i = queues - 1; i >= 0; i--) {
430         NetClientState *nc = qemu_get_subqueue(nic, i);
431 
432         qemu_cleanup_net_client(nc);
433         qemu_free_net_client(nc);
434     }
435 
436     g_free(nic);
437 }
438 
439 void qemu_foreach_nic(qemu_nic_foreach func, void *opaque)
440 {
441     NetClientState *nc;
442 
443     QTAILQ_FOREACH(nc, &net_clients, next) {
444         if (nc->info->type == NET_CLIENT_DRIVER_NIC) {
445             if (nc->queue_index == 0) {
446                 func(qemu_get_nic(nc), opaque);
447             }
448         }
449     }
450 }
451 
452 bool qemu_has_ufo(NetClientState *nc)
453 {
454     if (!nc || !nc->info->has_ufo) {
455         return false;
456     }
457 
458     return nc->info->has_ufo(nc);
459 }
460 
461 bool qemu_has_vnet_hdr(NetClientState *nc)
462 {
463     if (!nc || !nc->info->has_vnet_hdr) {
464         return false;
465     }
466 
467     return nc->info->has_vnet_hdr(nc);
468 }
469 
470 bool qemu_has_vnet_hdr_len(NetClientState *nc, int len)
471 {
472     if (!nc || !nc->info->has_vnet_hdr_len) {
473         return false;
474     }
475 
476     return nc->info->has_vnet_hdr_len(nc, len);
477 }
478 
479 void qemu_using_vnet_hdr(NetClientState *nc, bool enable)
480 {
481     if (!nc || !nc->info->using_vnet_hdr) {
482         return;
483     }
484 
485     nc->info->using_vnet_hdr(nc, enable);
486 }
487 
488 void qemu_set_offload(NetClientState *nc, int csum, int tso4, int tso6,
489                           int ecn, int ufo)
490 {
491     if (!nc || !nc->info->set_offload) {
492         return;
493     }
494 
495     nc->info->set_offload(nc, csum, tso4, tso6, ecn, ufo);
496 }
497 
498 void qemu_set_vnet_hdr_len(NetClientState *nc, int len)
499 {
500     if (!nc || !nc->info->set_vnet_hdr_len) {
501         return;
502     }
503 
504     nc->vnet_hdr_len = len;
505     nc->info->set_vnet_hdr_len(nc, len);
506 }
507 
508 int qemu_set_vnet_le(NetClientState *nc, bool is_le)
509 {
510 #ifdef HOST_WORDS_BIGENDIAN
511     if (!nc || !nc->info->set_vnet_le) {
512         return -ENOSYS;
513     }
514 
515     return nc->info->set_vnet_le(nc, is_le);
516 #else
517     return 0;
518 #endif
519 }
520 
521 int qemu_set_vnet_be(NetClientState *nc, bool is_be)
522 {
523 #ifdef HOST_WORDS_BIGENDIAN
524     return 0;
525 #else
526     if (!nc || !nc->info->set_vnet_be) {
527         return -ENOSYS;
528     }
529 
530     return nc->info->set_vnet_be(nc, is_be);
531 #endif
532 }
533 
534 int qemu_can_receive_packet(NetClientState *nc)
535 {
536     if (nc->receive_disabled) {
537         return 0;
538     } else if (nc->info->can_receive &&
539                !nc->info->can_receive(nc)) {
540         return 0;
541     }
542     return 1;
543 }
544 
545 int qemu_can_send_packet(NetClientState *sender)
546 {
547     int vm_running = runstate_is_running();
548 
549     if (!vm_running) {
550         return 0;
551     }
552 
553     if (!sender->peer) {
554         return 1;
555     }
556 
557     return qemu_can_receive_packet(sender->peer);
558 }
559 
560 static ssize_t filter_receive_iov(NetClientState *nc,
561                                   NetFilterDirection direction,
562                                   NetClientState *sender,
563                                   unsigned flags,
564                                   const struct iovec *iov,
565                                   int iovcnt,
566                                   NetPacketSent *sent_cb)
567 {
568     ssize_t ret = 0;
569     NetFilterState *nf = NULL;
570 
571     if (direction == NET_FILTER_DIRECTION_TX) {
572         QTAILQ_FOREACH(nf, &nc->filters, next) {
573             ret = qemu_netfilter_receive(nf, direction, sender, flags, iov,
574                                          iovcnt, sent_cb);
575             if (ret) {
576                 return ret;
577             }
578         }
579     } else {
580         QTAILQ_FOREACH_REVERSE(nf, &nc->filters, next) {
581             ret = qemu_netfilter_receive(nf, direction, sender, flags, iov,
582                                          iovcnt, sent_cb);
583             if (ret) {
584                 return ret;
585             }
586         }
587     }
588 
589     return ret;
590 }
591 
592 static ssize_t filter_receive(NetClientState *nc,
593                               NetFilterDirection direction,
594                               NetClientState *sender,
595                               unsigned flags,
596                               const uint8_t *data,
597                               size_t size,
598                               NetPacketSent *sent_cb)
599 {
600     struct iovec iov = {
601         .iov_base = (void *)data,
602         .iov_len = size
603     };
604 
605     return filter_receive_iov(nc, direction, sender, flags, &iov, 1, sent_cb);
606 }
607 
608 void qemu_purge_queued_packets(NetClientState *nc)
609 {
610     if (!nc->peer) {
611         return;
612     }
613 
614     qemu_net_queue_purge(nc->peer->incoming_queue, nc);
615 }
616 
617 void qemu_flush_or_purge_queued_packets(NetClientState *nc, bool purge)
618 {
619     nc->receive_disabled = 0;
620 
621     if (nc->peer && nc->peer->info->type == NET_CLIENT_DRIVER_HUBPORT) {
622         if (net_hub_flush(nc->peer)) {
623             qemu_notify_event();
624         }
625     }
626     if (qemu_net_queue_flush(nc->incoming_queue)) {
627         /* We emptied the queue successfully, signal to the IO thread to repoll
628          * the file descriptor (for tap, for example).
629          */
630         qemu_notify_event();
631     } else if (purge) {
632         /* Unable to empty the queue, purge remaining packets */
633         qemu_net_queue_purge(nc->incoming_queue, nc->peer);
634     }
635 }
636 
637 void qemu_flush_queued_packets(NetClientState *nc)
638 {
639     qemu_flush_or_purge_queued_packets(nc, false);
640 }
641 
642 static ssize_t qemu_send_packet_async_with_flags(NetClientState *sender,
643                                                  unsigned flags,
644                                                  const uint8_t *buf, int size,
645                                                  NetPacketSent *sent_cb)
646 {
647     NetQueue *queue;
648     int ret;
649 
650 #ifdef DEBUG_NET
651     printf("qemu_send_packet_async:\n");
652     qemu_hexdump(stdout, "net", buf, size);
653 #endif
654 
655     if (sender->link_down || !sender->peer) {
656         return size;
657     }
658 
659     /* Let filters handle the packet first */
660     ret = filter_receive(sender, NET_FILTER_DIRECTION_TX,
661                          sender, flags, buf, size, sent_cb);
662     if (ret) {
663         return ret;
664     }
665 
666     ret = filter_receive(sender->peer, NET_FILTER_DIRECTION_RX,
667                          sender, flags, buf, size, sent_cb);
668     if (ret) {
669         return ret;
670     }
671 
672     queue = sender->peer->incoming_queue;
673 
674     return qemu_net_queue_send(queue, sender, flags, buf, size, sent_cb);
675 }
676 
677 ssize_t qemu_send_packet_async(NetClientState *sender,
678                                const uint8_t *buf, int size,
679                                NetPacketSent *sent_cb)
680 {
681     return qemu_send_packet_async_with_flags(sender, QEMU_NET_PACKET_FLAG_NONE,
682                                              buf, size, sent_cb);
683 }
684 
685 ssize_t qemu_send_packet(NetClientState *nc, const uint8_t *buf, int size)
686 {
687     return qemu_send_packet_async(nc, buf, size, NULL);
688 }
689 
690 ssize_t qemu_receive_packet(NetClientState *nc, const uint8_t *buf, int size)
691 {
692     if (!qemu_can_receive_packet(nc)) {
693         return 0;
694     }
695 
696     return qemu_net_queue_receive(nc->incoming_queue, buf, size);
697 }
698 
699 ssize_t qemu_receive_packet_iov(NetClientState *nc, const struct iovec *iov,
700                                 int iovcnt)
701 {
702     if (!qemu_can_receive_packet(nc)) {
703         return 0;
704     }
705 
706     return qemu_net_queue_receive_iov(nc->incoming_queue, iov, iovcnt);
707 }
708 
709 ssize_t qemu_send_packet_raw(NetClientState *nc, const uint8_t *buf, int size)
710 {
711     return qemu_send_packet_async_with_flags(nc, QEMU_NET_PACKET_FLAG_RAW,
712                                              buf, size, NULL);
713 }
714 
715 static ssize_t nc_sendv_compat(NetClientState *nc, const struct iovec *iov,
716                                int iovcnt, unsigned flags)
717 {
718     uint8_t *buf = NULL;
719     uint8_t *buffer;
720     size_t offset;
721     ssize_t ret;
722 
723     if (iovcnt == 1) {
724         buffer = iov[0].iov_base;
725         offset = iov[0].iov_len;
726     } else {
727         offset = iov_size(iov, iovcnt);
728         if (offset > NET_BUFSIZE) {
729             return -1;
730         }
731         buf = g_malloc(offset);
732         buffer = buf;
733         offset = iov_to_buf(iov, iovcnt, 0, buf, offset);
734     }
735 
736     if (flags & QEMU_NET_PACKET_FLAG_RAW && nc->info->receive_raw) {
737         ret = nc->info->receive_raw(nc, buffer, offset);
738     } else {
739         ret = nc->info->receive(nc, buffer, offset);
740     }
741 
742     g_free(buf);
743     return ret;
744 }
745 
746 static ssize_t qemu_deliver_packet_iov(NetClientState *sender,
747                                        unsigned flags,
748                                        const struct iovec *iov,
749                                        int iovcnt,
750                                        void *opaque)
751 {
752     NetClientState *nc = opaque;
753     int ret;
754 
755 
756     if (nc->link_down) {
757         return iov_size(iov, iovcnt);
758     }
759 
760     if (nc->receive_disabled) {
761         return 0;
762     }
763 
764     if (nc->info->receive_iov && !(flags & QEMU_NET_PACKET_FLAG_RAW)) {
765         ret = nc->info->receive_iov(nc, iov, iovcnt);
766     } else {
767         ret = nc_sendv_compat(nc, iov, iovcnt, flags);
768     }
769 
770     if (ret == 0) {
771         nc->receive_disabled = 1;
772     }
773 
774     return ret;
775 }
776 
777 ssize_t qemu_sendv_packet_async(NetClientState *sender,
778                                 const struct iovec *iov, int iovcnt,
779                                 NetPacketSent *sent_cb)
780 {
781     NetQueue *queue;
782     size_t size = iov_size(iov, iovcnt);
783     int ret;
784 
785     if (size > NET_BUFSIZE) {
786         return size;
787     }
788 
789     if (sender->link_down || !sender->peer) {
790         return size;
791     }
792 
793     /* Let filters handle the packet first */
794     ret = filter_receive_iov(sender, NET_FILTER_DIRECTION_TX, sender,
795                              QEMU_NET_PACKET_FLAG_NONE, iov, iovcnt, sent_cb);
796     if (ret) {
797         return ret;
798     }
799 
800     ret = filter_receive_iov(sender->peer, NET_FILTER_DIRECTION_RX, sender,
801                              QEMU_NET_PACKET_FLAG_NONE, iov, iovcnt, sent_cb);
802     if (ret) {
803         return ret;
804     }
805 
806     queue = sender->peer->incoming_queue;
807 
808     return qemu_net_queue_send_iov(queue, sender,
809                                    QEMU_NET_PACKET_FLAG_NONE,
810                                    iov, iovcnt, sent_cb);
811 }
812 
813 ssize_t
814 qemu_sendv_packet(NetClientState *nc, const struct iovec *iov, int iovcnt)
815 {
816     return qemu_sendv_packet_async(nc, iov, iovcnt, NULL);
817 }
818 
819 NetClientState *qemu_find_netdev(const char *id)
820 {
821     NetClientState *nc;
822 
823     QTAILQ_FOREACH(nc, &net_clients, next) {
824         if (nc->info->type == NET_CLIENT_DRIVER_NIC)
825             continue;
826         if (!strcmp(nc->name, id)) {
827             return nc;
828         }
829     }
830 
831     return NULL;
832 }
833 
834 int qemu_find_net_clients_except(const char *id, NetClientState **ncs,
835                                  NetClientDriver type, int max)
836 {
837     NetClientState *nc;
838     int ret = 0;
839 
840     QTAILQ_FOREACH(nc, &net_clients, next) {
841         if (nc->info->type == type) {
842             continue;
843         }
844         if (!id || !strcmp(nc->name, id)) {
845             if (ret < max) {
846                 ncs[ret] = nc;
847             }
848             ret++;
849         }
850     }
851 
852     return ret;
853 }
854 
855 static int nic_get_free_idx(void)
856 {
857     int index;
858 
859     for (index = 0; index < MAX_NICS; index++)
860         if (!nd_table[index].used)
861             return index;
862     return -1;
863 }
864 
865 int qemu_show_nic_models(const char *arg, const char *const *models)
866 {
867     int i;
868 
869     if (!arg || !is_help_option(arg)) {
870         return 0;
871     }
872 
873     printf("Supported NIC models:\n");
874     for (i = 0 ; models[i]; i++) {
875         printf("%s\n", models[i]);
876     }
877     return 1;
878 }
879 
880 void qemu_check_nic_model(NICInfo *nd, const char *model)
881 {
882     const char *models[2];
883 
884     models[0] = model;
885     models[1] = NULL;
886 
887     if (qemu_show_nic_models(nd->model, models))
888         exit(0);
889     if (qemu_find_nic_model(nd, models, model) < 0)
890         exit(1);
891 }
892 
893 int qemu_find_nic_model(NICInfo *nd, const char * const *models,
894                         const char *default_model)
895 {
896     int i;
897 
898     if (!nd->model)
899         nd->model = g_strdup(default_model);
900 
901     for (i = 0 ; models[i]; i++) {
902         if (strcmp(nd->model, models[i]) == 0)
903             return i;
904     }
905 
906     error_report("Unsupported NIC model: %s", nd->model);
907     return -1;
908 }
909 
910 static int net_init_nic(const Netdev *netdev, const char *name,
911                         NetClientState *peer, Error **errp)
912 {
913     int idx;
914     NICInfo *nd;
915     const NetLegacyNicOptions *nic;
916 
917     assert(netdev->type == NET_CLIENT_DRIVER_NIC);
918     nic = &netdev->u.nic;
919 
920     idx = nic_get_free_idx();
921     if (idx == -1 || nb_nics >= MAX_NICS) {
922         error_setg(errp, "too many NICs");
923         return -1;
924     }
925 
926     nd = &nd_table[idx];
927 
928     memset(nd, 0, sizeof(*nd));
929 
930     if (nic->has_netdev) {
931         nd->netdev = qemu_find_netdev(nic->netdev);
932         if (!nd->netdev) {
933             error_setg(errp, "netdev '%s' not found", nic->netdev);
934             return -1;
935         }
936     } else {
937         assert(peer);
938         nd->netdev = peer;
939     }
940     nd->name = g_strdup(name);
941     if (nic->has_model) {
942         nd->model = g_strdup(nic->model);
943     }
944     if (nic->has_addr) {
945         nd->devaddr = g_strdup(nic->addr);
946     }
947 
948     if (nic->has_macaddr &&
949         net_parse_macaddr(nd->macaddr.a, nic->macaddr) < 0) {
950         error_setg(errp, "invalid syntax for ethernet address");
951         return -1;
952     }
953     if (nic->has_macaddr &&
954         is_multicast_ether_addr(nd->macaddr.a)) {
955         error_setg(errp,
956                    "NIC cannot have multicast MAC address (odd 1st byte)");
957         return -1;
958     }
959     qemu_macaddr_default_if_unset(&nd->macaddr);
960 
961     if (nic->has_vectors) {
962         if (nic->vectors > 0x7ffffff) {
963             error_setg(errp, "invalid # of vectors: %"PRIu32, nic->vectors);
964             return -1;
965         }
966         nd->nvectors = nic->vectors;
967     } else {
968         nd->nvectors = DEV_NVECTORS_UNSPECIFIED;
969     }
970 
971     nd->used = 1;
972     nb_nics++;
973 
974     return idx;
975 }
976 
977 
978 static int (* const net_client_init_fun[NET_CLIENT_DRIVER__MAX])(
979     const Netdev *netdev,
980     const char *name,
981     NetClientState *peer, Error **errp) = {
982         [NET_CLIENT_DRIVER_NIC]       = net_init_nic,
983 #ifdef CONFIG_SLIRP
984         [NET_CLIENT_DRIVER_USER]      = net_init_slirp,
985 #endif
986         [NET_CLIENT_DRIVER_TAP]       = net_init_tap,
987         [NET_CLIENT_DRIVER_SOCKET]    = net_init_socket,
988 #ifdef CONFIG_VDE
989         [NET_CLIENT_DRIVER_VDE]       = net_init_vde,
990 #endif
991 #ifdef CONFIG_NETMAP
992         [NET_CLIENT_DRIVER_NETMAP]    = net_init_netmap,
993 #endif
994 #ifdef CONFIG_NET_BRIDGE
995         [NET_CLIENT_DRIVER_BRIDGE]    = net_init_bridge,
996 #endif
997         [NET_CLIENT_DRIVER_HUBPORT]   = net_init_hubport,
998 #ifdef CONFIG_VHOST_NET_USER
999         [NET_CLIENT_DRIVER_VHOST_USER] = net_init_vhost_user,
1000 #endif
1001 #ifdef CONFIG_VHOST_NET_VDPA
1002         [NET_CLIENT_DRIVER_VHOST_VDPA] = net_init_vhost_vdpa,
1003 #endif
1004 #ifdef CONFIG_L2TPV3
1005         [NET_CLIENT_DRIVER_L2TPV3]    = net_init_l2tpv3,
1006 #endif
1007 };
1008 
1009 
1010 static int net_client_init1(const Netdev *netdev, bool is_netdev, Error **errp)
1011 {
1012     NetClientState *peer = NULL;
1013     NetClientState *nc;
1014 
1015     if (is_netdev) {
1016         if (netdev->type == NET_CLIENT_DRIVER_NIC ||
1017             !net_client_init_fun[netdev->type]) {
1018             error_setg(errp, QERR_INVALID_PARAMETER_VALUE, "type",
1019                        "a netdev backend type");
1020             return -1;
1021         }
1022     } else {
1023         if (netdev->type == NET_CLIENT_DRIVER_NONE) {
1024             return 0; /* nothing to do */
1025         }
1026         if (netdev->type == NET_CLIENT_DRIVER_HUBPORT ||
1027             !net_client_init_fun[netdev->type]) {
1028             error_setg(errp, QERR_INVALID_PARAMETER_VALUE, "type",
1029                        "a net backend type (maybe it is not compiled "
1030                        "into this binary)");
1031             return -1;
1032         }
1033 
1034         /* Do not add to a hub if it's a nic with a netdev= parameter. */
1035         if (netdev->type != NET_CLIENT_DRIVER_NIC ||
1036             !netdev->u.nic.has_netdev) {
1037             peer = net_hub_add_port(0, NULL, NULL);
1038         }
1039     }
1040 
1041     nc = qemu_find_netdev(netdev->id);
1042     if (nc) {
1043         error_setg(errp, "Duplicate ID '%s'", netdev->id);
1044         return -1;
1045     }
1046 
1047     if (net_client_init_fun[netdev->type](netdev, netdev->id, peer, errp) < 0) {
1048         /* FIXME drop when all init functions store an Error */
1049         if (errp && !*errp) {
1050             error_setg(errp, "Device '%s' could not be initialized",
1051                        NetClientDriver_str(netdev->type));
1052         }
1053         return -1;
1054     }
1055 
1056     if (is_netdev) {
1057         nc = qemu_find_netdev(netdev->id);
1058         assert(nc);
1059         nc->is_netdev = true;
1060     }
1061 
1062     return 0;
1063 }
1064 
1065 void show_netdevs(void)
1066 {
1067     int idx;
1068     const char *available_netdevs[] = {
1069         "socket",
1070         "hubport",
1071         "tap",
1072 #ifdef CONFIG_SLIRP
1073         "user",
1074 #endif
1075 #ifdef CONFIG_L2TPV3
1076         "l2tpv3",
1077 #endif
1078 #ifdef CONFIG_VDE
1079         "vde",
1080 #endif
1081 #ifdef CONFIG_NET_BRIDGE
1082         "bridge",
1083 #endif
1084 #ifdef CONFIG_NETMAP
1085         "netmap",
1086 #endif
1087 #ifdef CONFIG_POSIX
1088         "vhost-user",
1089 #endif
1090 #ifdef CONFIG_VHOST_VDPA
1091         "vhost-vdpa",
1092 #endif
1093     };
1094 
1095     qemu_printf("Available netdev backend types:\n");
1096     for (idx = 0; idx < ARRAY_SIZE(available_netdevs); idx++) {
1097         qemu_printf("%s\n", available_netdevs[idx]);
1098     }
1099 }
1100 
1101 static int net_client_init(QemuOpts *opts, bool is_netdev, Error **errp)
1102 {
1103     gchar **substrings = NULL;
1104     Netdev *object = NULL;
1105     int ret = -1;
1106     Visitor *v = opts_visitor_new(opts);
1107 
1108     /* Parse convenience option format ip6-net=fec0::0[/64] */
1109     const char *ip6_net = qemu_opt_get(opts, "ipv6-net");
1110 
1111     if (ip6_net) {
1112         char *prefix_addr;
1113         unsigned long prefix_len = 64; /* Default 64bit prefix length. */
1114 
1115         substrings = g_strsplit(ip6_net, "/", 2);
1116         if (!substrings || !substrings[0]) {
1117             error_setg(errp, QERR_INVALID_PARAMETER_VALUE, "ipv6-net",
1118                        "a valid IPv6 prefix");
1119             goto out;
1120         }
1121 
1122         prefix_addr = substrings[0];
1123 
1124         /* Handle user-specified prefix length. */
1125         if (substrings[1] &&
1126             qemu_strtoul(substrings[1], NULL, 10, &prefix_len))
1127         {
1128             error_setg(errp, QERR_INVALID_PARAMETER_VALUE,
1129                        "ipv6-prefixlen", "a number");
1130             goto out;
1131         }
1132 
1133         qemu_opt_set(opts, "ipv6-prefix", prefix_addr, &error_abort);
1134         qemu_opt_set_number(opts, "ipv6-prefixlen", prefix_len,
1135                             &error_abort);
1136         qemu_opt_unset(opts, "ipv6-net");
1137     }
1138 
1139     /* Create an ID for -net if the user did not specify one */
1140     if (!is_netdev && !qemu_opts_id(opts)) {
1141         qemu_opts_set_id(opts, id_generate(ID_NET));
1142     }
1143 
1144     if (visit_type_Netdev(v, NULL, &object, errp)) {
1145         ret = net_client_init1(object, is_netdev, errp);
1146     }
1147 
1148     qapi_free_Netdev(object);
1149 
1150 out:
1151     g_strfreev(substrings);
1152     visit_free(v);
1153     return ret;
1154 }
1155 
1156 void netdev_add(QemuOpts *opts, Error **errp)
1157 {
1158     net_client_init(opts, true, errp);
1159 }
1160 
1161 void qmp_netdev_add(Netdev *netdev, Error **errp)
1162 {
1163     if (!id_wellformed(netdev->id)) {
1164         error_setg(errp, QERR_INVALID_PARAMETER_VALUE, "id", "an identifier");
1165         return;
1166     }
1167 
1168     net_client_init1(netdev, true, errp);
1169 }
1170 
1171 void qmp_netdev_del(const char *id, Error **errp)
1172 {
1173     NetClientState *nc;
1174     QemuOpts *opts;
1175 
1176     nc = qemu_find_netdev(id);
1177     if (!nc) {
1178         error_set(errp, ERROR_CLASS_DEVICE_NOT_FOUND,
1179                   "Device '%s' not found", id);
1180         return;
1181     }
1182 
1183     if (!nc->is_netdev) {
1184         error_setg(errp, "Device '%s' is not a netdev", id);
1185         return;
1186     }
1187 
1188     qemu_del_net_client(nc);
1189 
1190     /*
1191      * Wart: we need to delete the QemuOpts associated with netdevs
1192      * created via CLI or HMP, to avoid bogus "Duplicate ID" errors in
1193      * HMP netdev_add.
1194      */
1195     opts = qemu_opts_find(qemu_find_opts("netdev"), id);
1196     if (opts) {
1197         qemu_opts_del(opts);
1198     }
1199 }
1200 
1201 static void netfilter_print_info(Monitor *mon, NetFilterState *nf)
1202 {
1203     char *str;
1204     ObjectProperty *prop;
1205     ObjectPropertyIterator iter;
1206     Visitor *v;
1207 
1208     /* generate info str */
1209     object_property_iter_init(&iter, OBJECT(nf));
1210     while ((prop = object_property_iter_next(&iter))) {
1211         if (!strcmp(prop->name, "type")) {
1212             continue;
1213         }
1214         v = string_output_visitor_new(false, &str);
1215         object_property_get(OBJECT(nf), prop->name, v, NULL);
1216         visit_complete(v, &str);
1217         visit_free(v);
1218         monitor_printf(mon, ",%s=%s", prop->name, str);
1219         g_free(str);
1220     }
1221     monitor_printf(mon, "\n");
1222 }
1223 
1224 void print_net_client(Monitor *mon, NetClientState *nc)
1225 {
1226     NetFilterState *nf;
1227 
1228     monitor_printf(mon, "%s: index=%d,type=%s,%s\n", nc->name,
1229                    nc->queue_index,
1230                    NetClientDriver_str(nc->info->type),
1231                    nc->info_str ? nc->info_str : "");
1232     if (!QTAILQ_EMPTY(&nc->filters)) {
1233         monitor_printf(mon, "filters:\n");
1234     }
1235     QTAILQ_FOREACH(nf, &nc->filters, next) {
1236         monitor_printf(mon, "  - %s: type=%s",
1237                        object_get_canonical_path_component(OBJECT(nf)),
1238                        object_get_typename(OBJECT(nf)));
1239         netfilter_print_info(mon, nf);
1240     }
1241 }
1242 
1243 RxFilterInfoList *qmp_query_rx_filter(bool has_name, const char *name,
1244                                       Error **errp)
1245 {
1246     NetClientState *nc;
1247     RxFilterInfoList *filter_list = NULL, **tail = &filter_list;
1248 
1249     QTAILQ_FOREACH(nc, &net_clients, next) {
1250         RxFilterInfo *info;
1251 
1252         if (has_name && strcmp(nc->name, name) != 0) {
1253             continue;
1254         }
1255 
1256         /* only query rx-filter information of NIC */
1257         if (nc->info->type != NET_CLIENT_DRIVER_NIC) {
1258             if (has_name) {
1259                 error_setg(errp, "net client(%s) isn't a NIC", name);
1260                 assert(!filter_list);
1261                 return NULL;
1262             }
1263             continue;
1264         }
1265 
1266         /* only query information on queue 0 since the info is per nic,
1267          * not per queue
1268          */
1269         if (nc->queue_index != 0)
1270             continue;
1271 
1272         if (nc->info->query_rx_filter) {
1273             info = nc->info->query_rx_filter(nc);
1274             QAPI_LIST_APPEND(tail, info);
1275         } else if (has_name) {
1276             error_setg(errp, "net client(%s) doesn't support"
1277                        " rx-filter querying", name);
1278             assert(!filter_list);
1279             return NULL;
1280         }
1281 
1282         if (has_name) {
1283             break;
1284         }
1285     }
1286 
1287     if (filter_list == NULL && has_name) {
1288         error_setg(errp, "invalid net client name: %s", name);
1289     }
1290 
1291     return filter_list;
1292 }
1293 
1294 NetdevInfoList *qmp_query_netdev(Error **errp)
1295 {
1296     NetdevInfoList *list = NULL;
1297     NetClientState *nc;
1298 
1299     QTAILQ_FOREACH(nc, &net_clients, next) {
1300         /*
1301          * Only look at netdevs (backend network devices), not for each queue
1302          * or NIC / hubport
1303          */
1304         if (nc->stored_config) {
1305             NetdevInfo *element = QAPI_CLONE(NetdevInfo, nc->stored_config);
1306 
1307             g_free(element->id); /* Need to dealloc empty id after clone */
1308             element->id = g_strdup(nc->name);
1309 
1310             element->has_peer_id = nc->peer != NULL;
1311             if (element->has_peer_id) {
1312                 element->peer_id = g_strdup(nc->peer->name);
1313             }
1314 
1315             QAPI_LIST_PREPEND(list, element);
1316         }
1317     }
1318 
1319     return list;
1320 }
1321 
1322 void hmp_info_network(Monitor *mon, const QDict *qdict)
1323 {
1324     NetClientState *nc, *peer;
1325     NetClientDriver type;
1326 
1327     net_hub_info(mon);
1328 
1329     QTAILQ_FOREACH(nc, &net_clients, next) {
1330         peer = nc->peer;
1331         type = nc->info->type;
1332 
1333         /* Skip if already printed in hub info */
1334         if (net_hub_id_for_client(nc, NULL) == 0) {
1335             continue;
1336         }
1337 
1338         if (!peer || type == NET_CLIENT_DRIVER_NIC) {
1339             print_net_client(mon, nc);
1340         } /* else it's a netdev connected to a NIC, printed with the NIC */
1341         if (peer && type == NET_CLIENT_DRIVER_NIC) {
1342             monitor_printf(mon, " \\ ");
1343             print_net_client(mon, peer);
1344         }
1345     }
1346 }
1347 
1348 void colo_notify_filters_event(int event, Error **errp)
1349 {
1350     NetClientState *nc;
1351     NetFilterState *nf;
1352     NetFilterClass *nfc = NULL;
1353     Error *local_err = NULL;
1354 
1355     QTAILQ_FOREACH(nc, &net_clients, next) {
1356         QTAILQ_FOREACH(nf, &nc->filters, next) {
1357             nfc = NETFILTER_GET_CLASS(OBJECT(nf));
1358             nfc->handle_event(nf, event, &local_err);
1359             if (local_err) {
1360                 error_propagate(errp, local_err);
1361                 return;
1362             }
1363         }
1364     }
1365 }
1366 
1367 void qmp_set_link(const char *name, bool up, Error **errp)
1368 {
1369     NetClientState *ncs[MAX_QUEUE_NUM];
1370     NetClientState *nc;
1371     int queues, i;
1372 
1373     queues = qemu_find_net_clients_except(name, ncs,
1374                                           NET_CLIENT_DRIVER__MAX,
1375                                           MAX_QUEUE_NUM);
1376 
1377     if (queues == 0) {
1378         error_set(errp, ERROR_CLASS_DEVICE_NOT_FOUND,
1379                   "Device '%s' not found", name);
1380         return;
1381     }
1382     nc = ncs[0];
1383 
1384     for (i = 0; i < queues; i++) {
1385         ncs[i]->link_down = !up;
1386     }
1387 
1388     if (nc->info->link_status_changed) {
1389         nc->info->link_status_changed(nc);
1390     }
1391 
1392     if (nc->peer) {
1393         /* Change peer link only if the peer is NIC and then notify peer.
1394          * If the peer is a HUBPORT or a backend, we do not change the
1395          * link status.
1396          *
1397          * This behavior is compatible with qemu hubs where there could be
1398          * multiple clients that can still communicate with each other in
1399          * disconnected mode. For now maintain this compatibility.
1400          */
1401         if (nc->peer->info->type == NET_CLIENT_DRIVER_NIC) {
1402             for (i = 0; i < queues; i++) {
1403                 ncs[i]->peer->link_down = !up;
1404             }
1405         }
1406         if (nc->peer->info->link_status_changed) {
1407             nc->peer->info->link_status_changed(nc->peer);
1408         }
1409     }
1410 }
1411 
1412 static void net_vm_change_state_handler(void *opaque, bool running,
1413                                         RunState state)
1414 {
1415     NetClientState *nc;
1416     NetClientState *tmp;
1417 
1418     QTAILQ_FOREACH_SAFE(nc, &net_clients, next, tmp) {
1419         if (running) {
1420             /* Flush queued packets and wake up backends. */
1421             if (nc->peer && qemu_can_send_packet(nc)) {
1422                 qemu_flush_queued_packets(nc->peer);
1423             }
1424         } else {
1425             /* Complete all queued packets, to guarantee we don't modify
1426              * state later when VM is not running.
1427              */
1428             qemu_flush_or_purge_queued_packets(nc, true);
1429         }
1430     }
1431 }
1432 
1433 void net_cleanup(void)
1434 {
1435     NetClientState *nc;
1436 
1437     /* We may del multiple entries during qemu_del_net_client(),
1438      * so QTAILQ_FOREACH_SAFE() is also not safe here.
1439      */
1440     while (!QTAILQ_EMPTY(&net_clients)) {
1441         nc = QTAILQ_FIRST(&net_clients);
1442         if (nc->info->type == NET_CLIENT_DRIVER_NIC) {
1443             qemu_del_nic(qemu_get_nic(nc));
1444         } else {
1445             qemu_del_net_client(nc);
1446         }
1447     }
1448 
1449     qemu_del_vm_change_state_handler(net_change_state_entry);
1450 }
1451 
1452 void net_check_clients(void)
1453 {
1454     NetClientState *nc;
1455     int i;
1456 
1457     net_hub_check_clients();
1458 
1459     QTAILQ_FOREACH(nc, &net_clients, next) {
1460         if (!nc->peer) {
1461             warn_report("%s %s has no peer",
1462                         nc->info->type == NET_CLIENT_DRIVER_NIC
1463                         ? "nic" : "netdev",
1464                         nc->name);
1465         }
1466     }
1467 
1468     /* Check that all NICs requested via -net nic actually got created.
1469      * NICs created via -device don't need to be checked here because
1470      * they are always instantiated.
1471      */
1472     for (i = 0; i < MAX_NICS; i++) {
1473         NICInfo *nd = &nd_table[i];
1474         if (nd->used && !nd->instantiated) {
1475             warn_report("requested NIC (%s, model %s) "
1476                         "was not created (not supported by this machine?)",
1477                         nd->name ? nd->name : "anonymous",
1478                         nd->model ? nd->model : "unspecified");
1479         }
1480     }
1481 }
1482 
1483 static int net_init_client(void *dummy, QemuOpts *opts, Error **errp)
1484 {
1485     return net_client_init(opts, false, errp);
1486 }
1487 
1488 static int net_init_netdev(void *dummy, QemuOpts *opts, Error **errp)
1489 {
1490     const char *type = qemu_opt_get(opts, "type");
1491 
1492     if (type && is_help_option(type)) {
1493         show_netdevs();
1494         exit(0);
1495     }
1496     return net_client_init(opts, true, errp);
1497 }
1498 
1499 /* For the convenience "--nic" parameter */
1500 static int net_param_nic(void *dummy, QemuOpts *opts, Error **errp)
1501 {
1502     char *mac, *nd_id;
1503     int idx, ret;
1504     NICInfo *ni;
1505     const char *type;
1506 
1507     type = qemu_opt_get(opts, "type");
1508     if (type && g_str_equal(type, "none")) {
1509         return 0;    /* Nothing to do, default_net is cleared in vl.c */
1510     }
1511 
1512     idx = nic_get_free_idx();
1513     if (idx == -1 || nb_nics >= MAX_NICS) {
1514         error_setg(errp, "no more on-board/default NIC slots available");
1515         return -1;
1516     }
1517 
1518     if (!type) {
1519         qemu_opt_set(opts, "type", "user", &error_abort);
1520     }
1521 
1522     ni = &nd_table[idx];
1523     memset(ni, 0, sizeof(*ni));
1524     ni->model = qemu_opt_get_del(opts, "model");
1525 
1526     /* Create an ID if the user did not specify one */
1527     nd_id = g_strdup(qemu_opts_id(opts));
1528     if (!nd_id) {
1529         nd_id = id_generate(ID_NET);
1530         qemu_opts_set_id(opts, nd_id);
1531     }
1532 
1533     /* Handle MAC address */
1534     mac = qemu_opt_get_del(opts, "mac");
1535     if (mac) {
1536         ret = net_parse_macaddr(ni->macaddr.a, mac);
1537         g_free(mac);
1538         if (ret) {
1539             error_setg(errp, "invalid syntax for ethernet address");
1540             goto out;
1541         }
1542         if (is_multicast_ether_addr(ni->macaddr.a)) {
1543             error_setg(errp, "NIC cannot have multicast MAC address");
1544             ret = -1;
1545             goto out;
1546         }
1547     }
1548     qemu_macaddr_default_if_unset(&ni->macaddr);
1549 
1550     ret = net_client_init(opts, true, errp);
1551     if (ret == 0) {
1552         ni->netdev = qemu_find_netdev(nd_id);
1553         ni->used = true;
1554         nb_nics++;
1555     }
1556 
1557 out:
1558     g_free(nd_id);
1559     return ret;
1560 }
1561 
1562 int net_init_clients(Error **errp)
1563 {
1564     net_change_state_entry =
1565         qemu_add_vm_change_state_handler(net_vm_change_state_handler, NULL);
1566 
1567     QTAILQ_INIT(&net_clients);
1568 
1569     if (qemu_opts_foreach(qemu_find_opts("netdev"),
1570                           net_init_netdev, NULL, errp)) {
1571         return -1;
1572     }
1573 
1574     if (qemu_opts_foreach(qemu_find_opts("nic"), net_param_nic, NULL, errp)) {
1575         return -1;
1576     }
1577 
1578     if (qemu_opts_foreach(qemu_find_opts("net"), net_init_client, NULL, errp)) {
1579         return -1;
1580     }
1581 
1582     return 0;
1583 }
1584 
1585 int net_client_parse(QemuOptsList *opts_list, const char *optarg)
1586 {
1587     if (!qemu_opts_parse_noisily(opts_list, optarg, true)) {
1588         return -1;
1589     }
1590 
1591     return 0;
1592 }
1593 
1594 /* From FreeBSD */
1595 /* XXX: optimize */
1596 uint32_t net_crc32(const uint8_t *p, int len)
1597 {
1598     uint32_t crc;
1599     int carry, i, j;
1600     uint8_t b;
1601 
1602     crc = 0xffffffff;
1603     for (i = 0; i < len; i++) {
1604         b = *p++;
1605         for (j = 0; j < 8; j++) {
1606             carry = ((crc & 0x80000000L) ? 1 : 0) ^ (b & 0x01);
1607             crc <<= 1;
1608             b >>= 1;
1609             if (carry) {
1610                 crc = ((crc ^ POLYNOMIAL_BE) | carry);
1611             }
1612         }
1613     }
1614 
1615     return crc;
1616 }
1617 
1618 uint32_t net_crc32_le(const uint8_t *p, int len)
1619 {
1620     uint32_t crc;
1621     int carry, i, j;
1622     uint8_t b;
1623 
1624     crc = 0xffffffff;
1625     for (i = 0; i < len; i++) {
1626         b = *p++;
1627         for (j = 0; j < 8; j++) {
1628             carry = (crc & 0x1) ^ (b & 0x01);
1629             crc >>= 1;
1630             b >>= 1;
1631             if (carry) {
1632                 crc ^= POLYNOMIAL_LE;
1633             }
1634         }
1635     }
1636 
1637     return crc;
1638 }
1639 
1640 QemuOptsList qemu_netdev_opts = {
1641     .name = "netdev",
1642     .implied_opt_name = "type",
1643     .head = QTAILQ_HEAD_INITIALIZER(qemu_netdev_opts.head),
1644     .desc = {
1645         /*
1646          * no elements => accept any params
1647          * validation will happen later
1648          */
1649         { /* end of list */ }
1650     },
1651 };
1652 
1653 QemuOptsList qemu_nic_opts = {
1654     .name = "nic",
1655     .implied_opt_name = "type",
1656     .head = QTAILQ_HEAD_INITIALIZER(qemu_nic_opts.head),
1657     .desc = {
1658         /*
1659          * no elements => accept any params
1660          * validation will happen later
1661          */
1662         { /* end of list */ }
1663     },
1664 };
1665 
1666 QemuOptsList qemu_net_opts = {
1667     .name = "net",
1668     .implied_opt_name = "type",
1669     .head = QTAILQ_HEAD_INITIALIZER(qemu_net_opts.head),
1670     .desc = {
1671         /*
1672          * no elements => accept any params
1673          * validation will happen later
1674          */
1675         { /* end of list */ }
1676     },
1677 };
1678 
1679 void net_socket_rs_init(SocketReadState *rs,
1680                         SocketReadStateFinalize *finalize,
1681                         bool vnet_hdr)
1682 {
1683     rs->state = 0;
1684     rs->vnet_hdr = vnet_hdr;
1685     rs->index = 0;
1686     rs->packet_len = 0;
1687     rs->vnet_hdr_len = 0;
1688     memset(rs->buf, 0, sizeof(rs->buf));
1689     rs->finalize = finalize;
1690 }
1691 
1692 /*
1693  * Returns
1694  * 0: success
1695  * -1: error occurs
1696  */
1697 int net_fill_rstate(SocketReadState *rs, const uint8_t *buf, int size)
1698 {
1699     unsigned int l;
1700 
1701     while (size > 0) {
1702         /* Reassemble a packet from the network.
1703          * 0 = getting length.
1704          * 1 = getting vnet header length.
1705          * 2 = getting data.
1706          */
1707         switch (rs->state) {
1708         case 0:
1709             l = 4 - rs->index;
1710             if (l > size) {
1711                 l = size;
1712             }
1713             memcpy(rs->buf + rs->index, buf, l);
1714             buf += l;
1715             size -= l;
1716             rs->index += l;
1717             if (rs->index == 4) {
1718                 /* got length */
1719                 rs->packet_len = ntohl(*(uint32_t *)rs->buf);
1720                 rs->index = 0;
1721                 if (rs->vnet_hdr) {
1722                     rs->state = 1;
1723                 } else {
1724                     rs->state = 2;
1725                     rs->vnet_hdr_len = 0;
1726                 }
1727             }
1728             break;
1729         case 1:
1730             l = 4 - rs->index;
1731             if (l > size) {
1732                 l = size;
1733             }
1734             memcpy(rs->buf + rs->index, buf, l);
1735             buf += l;
1736             size -= l;
1737             rs->index += l;
1738             if (rs->index == 4) {
1739                 /* got vnet header length */
1740                 rs->vnet_hdr_len = ntohl(*(uint32_t *)rs->buf);
1741                 rs->index = 0;
1742                 rs->state = 2;
1743             }
1744             break;
1745         case 2:
1746             l = rs->packet_len - rs->index;
1747             if (l > size) {
1748                 l = size;
1749             }
1750             if (rs->index + l <= sizeof(rs->buf)) {
1751                 memcpy(rs->buf + rs->index, buf, l);
1752             } else {
1753                 fprintf(stderr, "serious error: oversized packet received,"
1754                     "connection terminated.\n");
1755                 rs->index = rs->state = 0;
1756                 return -1;
1757             }
1758 
1759             rs->index += l;
1760             buf += l;
1761             size -= l;
1762             if (rs->index >= rs->packet_len) {
1763                 rs->index = 0;
1764                 rs->state = 0;
1765                 assert(rs->finalize);
1766                 rs->finalize(rs);
1767             }
1768             break;
1769         }
1770     }
1771 
1772     assert(size == 0);
1773     return 0;
1774 }
1775