xref: /openbmc/qemu/net/net.c (revision 9d2b5f2c)
1 /*
2  * QEMU System Emulator
3  *
4  * Copyright (c) 2003-2008 Fabrice Bellard
5  *
6  * Permission is hereby granted, free of charge, to any person obtaining a copy
7  * of this software and associated documentation files (the "Software"), to deal
8  * in the Software without restriction, including without limitation the rights
9  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
10  * copies of the Software, and to permit persons to whom the Software is
11  * furnished to do so, subject to the following conditions:
12  *
13  * The above copyright notice and this permission notice shall be included in
14  * all copies or substantial portions of the Software.
15  *
16  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
17  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
19  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
20  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
21  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
22  * THE SOFTWARE.
23  */
24 
25 #include "qemu/osdep.h"
26 
27 #include "net/net.h"
28 #include "clients.h"
29 #include "hub.h"
30 #include "hw/qdev-properties.h"
31 #include "net/slirp.h"
32 #include "net/eth.h"
33 #include "util.h"
34 
35 #include "monitor/monitor.h"
36 #include "qemu/help_option.h"
37 #include "qapi/qapi-commands-net.h"
38 #include "qapi/qapi-visit-net.h"
39 #include "qapi/qmp/qdict.h"
40 #include "qapi/qmp/qerror.h"
41 #include "qemu/error-report.h"
42 #include "qemu/sockets.h"
43 #include "qemu/cutils.h"
44 #include "qemu/config-file.h"
45 #include "qemu/ctype.h"
46 #include "qemu/id.h"
47 #include "qemu/iov.h"
48 #include "qemu/qemu-print.h"
49 #include "qemu/main-loop.h"
50 #include "qemu/option.h"
51 #include "qemu/keyval.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 #include "qapi/qobject-input-visitor.h"
59 
60 /* Net bridge is currently not supported for W32. */
61 #if !defined(_WIN32)
62 # define CONFIG_NET_BRIDGE
63 #endif
64 
65 static VMChangeStateEntry *net_change_state_entry;
66 NetClientStateList net_clients;
67 
68 typedef struct NetdevQueueEntry {
69     Netdev *nd;
70     Location loc;
71     QSIMPLEQ_ENTRY(NetdevQueueEntry) entry;
72 } NetdevQueueEntry;
73 
74 typedef QSIMPLEQ_HEAD(, NetdevQueueEntry) NetdevQueue;
75 
76 static NetdevQueue nd_queue = QSIMPLEQ_HEAD_INITIALIZER(nd_queue);
77 
78 /***********************************************************/
79 /* network device redirectors */
80 
81 int convert_host_port(struct sockaddr_in *saddr, const char *host,
82                       const char *port, Error **errp)
83 {
84     struct hostent *he;
85     const char *r;
86     long p;
87 
88     memset(saddr, 0, sizeof(*saddr));
89 
90     saddr->sin_family = AF_INET;
91     if (host[0] == '\0') {
92         saddr->sin_addr.s_addr = 0;
93     } else {
94         if (qemu_isdigit(host[0])) {
95             if (!inet_aton(host, &saddr->sin_addr)) {
96                 error_setg(errp, "host address '%s' is not a valid "
97                            "IPv4 address", host);
98                 return -1;
99             }
100         } else {
101             he = gethostbyname(host);
102             if (he == NULL) {
103                 error_setg(errp, "can't resolve host address '%s'", host);
104                 return -1;
105             }
106             saddr->sin_addr = *(struct in_addr *)he->h_addr;
107         }
108     }
109     if (qemu_strtol(port, &r, 0, &p) != 0) {
110         error_setg(errp, "port number '%s' is invalid", port);
111         return -1;
112     }
113     saddr->sin_port = htons(p);
114     return 0;
115 }
116 
117 int parse_host_port(struct sockaddr_in *saddr, const char *str,
118                     Error **errp)
119 {
120     gchar **substrings;
121     int ret;
122 
123     substrings = g_strsplit(str, ":", 2);
124     if (!substrings || !substrings[0] || !substrings[1]) {
125         error_setg(errp, "host address '%s' doesn't contain ':' "
126                    "separating host from port", str);
127         ret = -1;
128         goto out;
129     }
130 
131     ret = convert_host_port(saddr, substrings[0], substrings[1], errp);
132 
133 out:
134     g_strfreev(substrings);
135     return ret;
136 }
137 
138 char *qemu_mac_strdup_printf(const uint8_t *macaddr)
139 {
140     return g_strdup_printf("%.2x:%.2x:%.2x:%.2x:%.2x:%.2x",
141                            macaddr[0], macaddr[1], macaddr[2],
142                            macaddr[3], macaddr[4], macaddr[5]);
143 }
144 
145 void qemu_set_info_str(NetClientState *nc, const char *fmt, ...)
146 {
147     va_list ap;
148 
149     va_start(ap, fmt);
150     vsnprintf(nc->info_str, sizeof(nc->info_str), fmt, ap);
151     va_end(ap);
152 }
153 
154 void qemu_format_nic_info_str(NetClientState *nc, uint8_t macaddr[6])
155 {
156     qemu_set_info_str(nc, "model=%s,macaddr=%02x:%02x:%02x:%02x:%02x:%02x",
157                       nc->model, macaddr[0], macaddr[1], macaddr[2],
158                       macaddr[3], macaddr[4], macaddr[5]);
159 }
160 
161 static int mac_table[256] = {0};
162 
163 static void qemu_macaddr_set_used(MACAddr *macaddr)
164 {
165     int index;
166 
167     for (index = 0x56; index < 0xFF; index++) {
168         if (macaddr->a[5] == index) {
169             mac_table[index]++;
170         }
171     }
172 }
173 
174 static void qemu_macaddr_set_free(MACAddr *macaddr)
175 {
176     int index;
177     static const MACAddr base = { .a = { 0x52, 0x54, 0x00, 0x12, 0x34, 0 } };
178 
179     if (memcmp(macaddr->a, &base.a, (sizeof(base.a) - 1)) != 0) {
180         return;
181     }
182     for (index = 0x56; index < 0xFF; index++) {
183         if (macaddr->a[5] == index) {
184             mac_table[index]--;
185         }
186     }
187 }
188 
189 static int qemu_macaddr_get_free(void)
190 {
191     int index;
192 
193     for (index = 0x56; index < 0xFF; index++) {
194         if (mac_table[index] == 0) {
195             return index;
196         }
197     }
198 
199     return -1;
200 }
201 
202 void qemu_macaddr_default_if_unset(MACAddr *macaddr)
203 {
204     static const MACAddr zero = { .a = { 0,0,0,0,0,0 } };
205     static const MACAddr base = { .a = { 0x52, 0x54, 0x00, 0x12, 0x34, 0 } };
206 
207     if (memcmp(macaddr, &zero, sizeof(zero)) != 0) {
208         if (memcmp(macaddr->a, &base.a, (sizeof(base.a) - 1)) != 0) {
209             return;
210         } else {
211             qemu_macaddr_set_used(macaddr);
212             return;
213         }
214     }
215 
216     macaddr->a[0] = 0x52;
217     macaddr->a[1] = 0x54;
218     macaddr->a[2] = 0x00;
219     macaddr->a[3] = 0x12;
220     macaddr->a[4] = 0x34;
221     macaddr->a[5] = qemu_macaddr_get_free();
222     qemu_macaddr_set_used(macaddr);
223 }
224 
225 /**
226  * Generate a name for net client
227  *
228  * Only net clients created with the legacy -net option and NICs need this.
229  */
230 static char *assign_name(NetClientState *nc1, const char *model)
231 {
232     NetClientState *nc;
233     int id = 0;
234 
235     QTAILQ_FOREACH(nc, &net_clients, next) {
236         if (nc == nc1) {
237             continue;
238         }
239         if (strcmp(nc->model, model) == 0) {
240             id++;
241         }
242     }
243 
244     return g_strdup_printf("%s.%d", model, id);
245 }
246 
247 static void qemu_net_client_destructor(NetClientState *nc)
248 {
249     g_free(nc);
250 }
251 static ssize_t qemu_deliver_packet_iov(NetClientState *sender,
252                                        unsigned flags,
253                                        const struct iovec *iov,
254                                        int iovcnt,
255                                        void *opaque);
256 
257 static void qemu_net_client_setup(NetClientState *nc,
258                                   NetClientInfo *info,
259                                   NetClientState *peer,
260                                   const char *model,
261                                   const char *name,
262                                   NetClientDestructor *destructor,
263                                   bool is_datapath)
264 {
265     nc->info = info;
266     nc->model = g_strdup(model);
267     if (name) {
268         nc->name = g_strdup(name);
269     } else {
270         nc->name = assign_name(nc, model);
271     }
272 
273     if (peer) {
274         assert(!peer->peer);
275         nc->peer = peer;
276         peer->peer = nc;
277     }
278     QTAILQ_INSERT_TAIL(&net_clients, nc, next);
279 
280     nc->incoming_queue = qemu_new_net_queue(qemu_deliver_packet_iov, nc);
281     nc->destructor = destructor;
282     nc->is_datapath = is_datapath;
283     QTAILQ_INIT(&nc->filters);
284 }
285 
286 NetClientState *qemu_new_net_client(NetClientInfo *info,
287                                     NetClientState *peer,
288                                     const char *model,
289                                     const char *name)
290 {
291     NetClientState *nc;
292 
293     assert(info->size >= sizeof(NetClientState));
294 
295     nc = g_malloc0(info->size);
296     qemu_net_client_setup(nc, info, peer, model, name,
297                           qemu_net_client_destructor, true);
298 
299     return nc;
300 }
301 
302 NetClientState *qemu_new_net_control_client(NetClientInfo *info,
303                                             NetClientState *peer,
304                                             const char *model,
305                                             const char *name)
306 {
307     NetClientState *nc;
308 
309     assert(info->size >= sizeof(NetClientState));
310 
311     nc = g_malloc0(info->size);
312     qemu_net_client_setup(nc, info, peer, model, name,
313                           qemu_net_client_destructor, false);
314 
315     return nc;
316 }
317 
318 NICState *qemu_new_nic(NetClientInfo *info,
319                        NICConf *conf,
320                        const char *model,
321                        const char *name,
322                        void *opaque)
323 {
324     NetClientState **peers = conf->peers.ncs;
325     NICState *nic;
326     int i, queues = MAX(1, conf->peers.queues);
327 
328     assert(info->type == NET_CLIENT_DRIVER_NIC);
329     assert(info->size >= sizeof(NICState));
330 
331     nic = g_malloc0(info->size + sizeof(NetClientState) * queues);
332     nic->ncs = (void *)nic + info->size;
333     nic->conf = conf;
334     nic->opaque = opaque;
335 
336     for (i = 0; i < queues; i++) {
337         qemu_net_client_setup(&nic->ncs[i], info, peers[i], model, name,
338                               NULL, true);
339         nic->ncs[i].queue_index = i;
340     }
341 
342     return nic;
343 }
344 
345 NetClientState *qemu_get_subqueue(NICState *nic, int queue_index)
346 {
347     return nic->ncs + queue_index;
348 }
349 
350 NetClientState *qemu_get_queue(NICState *nic)
351 {
352     return qemu_get_subqueue(nic, 0);
353 }
354 
355 NICState *qemu_get_nic(NetClientState *nc)
356 {
357     NetClientState *nc0 = nc - nc->queue_index;
358 
359     return (NICState *)((void *)nc0 - nc->info->size);
360 }
361 
362 void *qemu_get_nic_opaque(NetClientState *nc)
363 {
364     NICState *nic = qemu_get_nic(nc);
365 
366     return nic->opaque;
367 }
368 
369 NetClientState *qemu_get_peer(NetClientState *nc, int queue_index)
370 {
371     assert(nc != NULL);
372     NetClientState *ncs = nc + queue_index;
373     return ncs->peer;
374 }
375 
376 static void qemu_cleanup_net_client(NetClientState *nc)
377 {
378     QTAILQ_REMOVE(&net_clients, nc, next);
379 
380     if (nc->info->cleanup) {
381         nc->info->cleanup(nc);
382     }
383 }
384 
385 static void qemu_free_net_client(NetClientState *nc)
386 {
387     if (nc->incoming_queue) {
388         qemu_del_net_queue(nc->incoming_queue);
389     }
390     if (nc->peer) {
391         nc->peer->peer = NULL;
392     }
393     g_free(nc->name);
394     g_free(nc->model);
395     if (nc->destructor) {
396         nc->destructor(nc);
397     }
398 }
399 
400 void qemu_del_net_client(NetClientState *nc)
401 {
402     NetClientState *ncs[MAX_QUEUE_NUM];
403     int queues, i;
404     NetFilterState *nf, *next;
405 
406     assert(nc->info->type != NET_CLIENT_DRIVER_NIC);
407 
408     /* If the NetClientState belongs to a multiqueue backend, we will change all
409      * other NetClientStates also.
410      */
411     queues = qemu_find_net_clients_except(nc->name, ncs,
412                                           NET_CLIENT_DRIVER_NIC,
413                                           MAX_QUEUE_NUM);
414     assert(queues != 0);
415 
416     QTAILQ_FOREACH_SAFE(nf, &nc->filters, next, next) {
417         object_unparent(OBJECT(nf));
418     }
419 
420     /* If there is a peer NIC, delete and cleanup client, but do not free. */
421     if (nc->peer && nc->peer->info->type == NET_CLIENT_DRIVER_NIC) {
422         NICState *nic = qemu_get_nic(nc->peer);
423         if (nic->peer_deleted) {
424             return;
425         }
426         nic->peer_deleted = true;
427 
428         for (i = 0; i < queues; i++) {
429             ncs[i]->peer->link_down = true;
430         }
431 
432         if (nc->peer->info->link_status_changed) {
433             nc->peer->info->link_status_changed(nc->peer);
434         }
435 
436         for (i = 0; i < queues; i++) {
437             qemu_cleanup_net_client(ncs[i]);
438         }
439 
440         return;
441     }
442 
443     for (i = 0; i < queues; i++) {
444         qemu_cleanup_net_client(ncs[i]);
445         qemu_free_net_client(ncs[i]);
446     }
447 }
448 
449 void qemu_del_nic(NICState *nic)
450 {
451     int i, queues = MAX(nic->conf->peers.queues, 1);
452 
453     qemu_macaddr_set_free(&nic->conf->macaddr);
454 
455     for (i = 0; i < queues; i++) {
456         NetClientState *nc = qemu_get_subqueue(nic, i);
457         /* If this is a peer NIC and peer has already been deleted, free it now. */
458         if (nic->peer_deleted) {
459             qemu_free_net_client(nc->peer);
460         } else if (nc->peer) {
461             /* if there are RX packets pending, complete them */
462             qemu_purge_queued_packets(nc->peer);
463         }
464     }
465 
466     for (i = queues - 1; i >= 0; i--) {
467         NetClientState *nc = qemu_get_subqueue(nic, i);
468 
469         qemu_cleanup_net_client(nc);
470         qemu_free_net_client(nc);
471     }
472 
473     g_free(nic);
474 }
475 
476 void qemu_foreach_nic(qemu_nic_foreach func, void *opaque)
477 {
478     NetClientState *nc;
479 
480     QTAILQ_FOREACH(nc, &net_clients, next) {
481         if (nc->info->type == NET_CLIENT_DRIVER_NIC) {
482             if (nc->queue_index == 0) {
483                 func(qemu_get_nic(nc), opaque);
484             }
485         }
486     }
487 }
488 
489 bool qemu_has_ufo(NetClientState *nc)
490 {
491     if (!nc || !nc->info->has_ufo) {
492         return false;
493     }
494 
495     return nc->info->has_ufo(nc);
496 }
497 
498 bool qemu_has_vnet_hdr(NetClientState *nc)
499 {
500     if (!nc || !nc->info->has_vnet_hdr) {
501         return false;
502     }
503 
504     return nc->info->has_vnet_hdr(nc);
505 }
506 
507 bool qemu_has_vnet_hdr_len(NetClientState *nc, int len)
508 {
509     if (!nc || !nc->info->has_vnet_hdr_len) {
510         return false;
511     }
512 
513     return nc->info->has_vnet_hdr_len(nc, len);
514 }
515 
516 void qemu_using_vnet_hdr(NetClientState *nc, bool enable)
517 {
518     if (!nc || !nc->info->using_vnet_hdr) {
519         return;
520     }
521 
522     nc->info->using_vnet_hdr(nc, enable);
523 }
524 
525 void qemu_set_offload(NetClientState *nc, int csum, int tso4, int tso6,
526                           int ecn, int ufo)
527 {
528     if (!nc || !nc->info->set_offload) {
529         return;
530     }
531 
532     nc->info->set_offload(nc, csum, tso4, tso6, ecn, ufo);
533 }
534 
535 void qemu_set_vnet_hdr_len(NetClientState *nc, int len)
536 {
537     if (!nc || !nc->info->set_vnet_hdr_len) {
538         return;
539     }
540 
541     nc->vnet_hdr_len = len;
542     nc->info->set_vnet_hdr_len(nc, len);
543 }
544 
545 int qemu_set_vnet_le(NetClientState *nc, bool is_le)
546 {
547 #if HOST_BIG_ENDIAN
548     if (!nc || !nc->info->set_vnet_le) {
549         return -ENOSYS;
550     }
551 
552     return nc->info->set_vnet_le(nc, is_le);
553 #else
554     return 0;
555 #endif
556 }
557 
558 int qemu_set_vnet_be(NetClientState *nc, bool is_be)
559 {
560 #if HOST_BIG_ENDIAN
561     return 0;
562 #else
563     if (!nc || !nc->info->set_vnet_be) {
564         return -ENOSYS;
565     }
566 
567     return nc->info->set_vnet_be(nc, is_be);
568 #endif
569 }
570 
571 int qemu_can_receive_packet(NetClientState *nc)
572 {
573     if (nc->receive_disabled) {
574         return 0;
575     } else if (nc->info->can_receive &&
576                !nc->info->can_receive(nc)) {
577         return 0;
578     }
579     return 1;
580 }
581 
582 int qemu_can_send_packet(NetClientState *sender)
583 {
584     int vm_running = runstate_is_running();
585 
586     if (!vm_running) {
587         return 0;
588     }
589 
590     if (!sender->peer) {
591         return 1;
592     }
593 
594     return qemu_can_receive_packet(sender->peer);
595 }
596 
597 static ssize_t filter_receive_iov(NetClientState *nc,
598                                   NetFilterDirection direction,
599                                   NetClientState *sender,
600                                   unsigned flags,
601                                   const struct iovec *iov,
602                                   int iovcnt,
603                                   NetPacketSent *sent_cb)
604 {
605     ssize_t ret = 0;
606     NetFilterState *nf = NULL;
607 
608     if (direction == NET_FILTER_DIRECTION_TX) {
609         QTAILQ_FOREACH(nf, &nc->filters, next) {
610             ret = qemu_netfilter_receive(nf, direction, sender, flags, iov,
611                                          iovcnt, sent_cb);
612             if (ret) {
613                 return ret;
614             }
615         }
616     } else {
617         QTAILQ_FOREACH_REVERSE(nf, &nc->filters, next) {
618             ret = qemu_netfilter_receive(nf, direction, sender, flags, iov,
619                                          iovcnt, sent_cb);
620             if (ret) {
621                 return ret;
622             }
623         }
624     }
625 
626     return ret;
627 }
628 
629 static ssize_t filter_receive(NetClientState *nc,
630                               NetFilterDirection direction,
631                               NetClientState *sender,
632                               unsigned flags,
633                               const uint8_t *data,
634                               size_t size,
635                               NetPacketSent *sent_cb)
636 {
637     struct iovec iov = {
638         .iov_base = (void *)data,
639         .iov_len = size
640     };
641 
642     return filter_receive_iov(nc, direction, sender, flags, &iov, 1, sent_cb);
643 }
644 
645 void qemu_purge_queued_packets(NetClientState *nc)
646 {
647     if (!nc->peer) {
648         return;
649     }
650 
651     qemu_net_queue_purge(nc->peer->incoming_queue, nc);
652 }
653 
654 void qemu_flush_or_purge_queued_packets(NetClientState *nc, bool purge)
655 {
656     nc->receive_disabled = 0;
657 
658     if (nc->peer && nc->peer->info->type == NET_CLIENT_DRIVER_HUBPORT) {
659         if (net_hub_flush(nc->peer)) {
660             qemu_notify_event();
661         }
662     }
663     if (qemu_net_queue_flush(nc->incoming_queue)) {
664         /* We emptied the queue successfully, signal to the IO thread to repoll
665          * the file descriptor (for tap, for example).
666          */
667         qemu_notify_event();
668     } else if (purge) {
669         /* Unable to empty the queue, purge remaining packets */
670         qemu_net_queue_purge(nc->incoming_queue, nc->peer);
671     }
672 }
673 
674 void qemu_flush_queued_packets(NetClientState *nc)
675 {
676     qemu_flush_or_purge_queued_packets(nc, false);
677 }
678 
679 static ssize_t qemu_send_packet_async_with_flags(NetClientState *sender,
680                                                  unsigned flags,
681                                                  const uint8_t *buf, int size,
682                                                  NetPacketSent *sent_cb)
683 {
684     NetQueue *queue;
685     int ret;
686 
687 #ifdef DEBUG_NET
688     printf("qemu_send_packet_async:\n");
689     qemu_hexdump(stdout, "net", buf, size);
690 #endif
691 
692     if (sender->link_down || !sender->peer) {
693         return size;
694     }
695 
696     /* Let filters handle the packet first */
697     ret = filter_receive(sender, NET_FILTER_DIRECTION_TX,
698                          sender, flags, buf, size, sent_cb);
699     if (ret) {
700         return ret;
701     }
702 
703     ret = filter_receive(sender->peer, NET_FILTER_DIRECTION_RX,
704                          sender, flags, buf, size, sent_cb);
705     if (ret) {
706         return ret;
707     }
708 
709     queue = sender->peer->incoming_queue;
710 
711     return qemu_net_queue_send(queue, sender, flags, buf, size, sent_cb);
712 }
713 
714 ssize_t qemu_send_packet_async(NetClientState *sender,
715                                const uint8_t *buf, int size,
716                                NetPacketSent *sent_cb)
717 {
718     return qemu_send_packet_async_with_flags(sender, QEMU_NET_PACKET_FLAG_NONE,
719                                              buf, size, sent_cb);
720 }
721 
722 ssize_t qemu_send_packet(NetClientState *nc, const uint8_t *buf, int size)
723 {
724     return qemu_send_packet_async(nc, buf, size, NULL);
725 }
726 
727 ssize_t qemu_receive_packet(NetClientState *nc, const uint8_t *buf, int size)
728 {
729     if (!qemu_can_receive_packet(nc)) {
730         return 0;
731     }
732 
733     return qemu_net_queue_receive(nc->incoming_queue, buf, size);
734 }
735 
736 ssize_t qemu_receive_packet_iov(NetClientState *nc, const struct iovec *iov,
737                                 int iovcnt)
738 {
739     if (!qemu_can_receive_packet(nc)) {
740         return 0;
741     }
742 
743     return qemu_net_queue_receive_iov(nc->incoming_queue, iov, iovcnt);
744 }
745 
746 ssize_t qemu_send_packet_raw(NetClientState *nc, const uint8_t *buf, int size)
747 {
748     return qemu_send_packet_async_with_flags(nc, QEMU_NET_PACKET_FLAG_RAW,
749                                              buf, size, NULL);
750 }
751 
752 static ssize_t nc_sendv_compat(NetClientState *nc, const struct iovec *iov,
753                                int iovcnt, unsigned flags)
754 {
755     uint8_t *buf = NULL;
756     uint8_t *buffer;
757     size_t offset;
758     ssize_t ret;
759 
760     if (iovcnt == 1) {
761         buffer = iov[0].iov_base;
762         offset = iov[0].iov_len;
763     } else {
764         offset = iov_size(iov, iovcnt);
765         if (offset > NET_BUFSIZE) {
766             return -1;
767         }
768         buf = g_malloc(offset);
769         buffer = buf;
770         offset = iov_to_buf(iov, iovcnt, 0, buf, offset);
771     }
772 
773     if (flags & QEMU_NET_PACKET_FLAG_RAW && nc->info->receive_raw) {
774         ret = nc->info->receive_raw(nc, buffer, offset);
775     } else {
776         ret = nc->info->receive(nc, buffer, offset);
777     }
778 
779     g_free(buf);
780     return ret;
781 }
782 
783 static ssize_t qemu_deliver_packet_iov(NetClientState *sender,
784                                        unsigned flags,
785                                        const struct iovec *iov,
786                                        int iovcnt,
787                                        void *opaque)
788 {
789     NetClientState *nc = opaque;
790     int ret;
791 
792 
793     if (nc->link_down) {
794         return iov_size(iov, iovcnt);
795     }
796 
797     if (nc->receive_disabled) {
798         return 0;
799     }
800 
801     if (nc->info->receive_iov && !(flags & QEMU_NET_PACKET_FLAG_RAW)) {
802         ret = nc->info->receive_iov(nc, iov, iovcnt);
803     } else {
804         ret = nc_sendv_compat(nc, iov, iovcnt, flags);
805     }
806 
807     if (ret == 0) {
808         nc->receive_disabled = 1;
809     }
810 
811     return ret;
812 }
813 
814 ssize_t qemu_sendv_packet_async(NetClientState *sender,
815                                 const struct iovec *iov, int iovcnt,
816                                 NetPacketSent *sent_cb)
817 {
818     NetQueue *queue;
819     size_t size = iov_size(iov, iovcnt);
820     int ret;
821 
822     if (size > NET_BUFSIZE) {
823         return size;
824     }
825 
826     if (sender->link_down || !sender->peer) {
827         return size;
828     }
829 
830     /* Let filters handle the packet first */
831     ret = filter_receive_iov(sender, NET_FILTER_DIRECTION_TX, sender,
832                              QEMU_NET_PACKET_FLAG_NONE, iov, iovcnt, sent_cb);
833     if (ret) {
834         return ret;
835     }
836 
837     ret = filter_receive_iov(sender->peer, NET_FILTER_DIRECTION_RX, sender,
838                              QEMU_NET_PACKET_FLAG_NONE, iov, iovcnt, sent_cb);
839     if (ret) {
840         return ret;
841     }
842 
843     queue = sender->peer->incoming_queue;
844 
845     return qemu_net_queue_send_iov(queue, sender,
846                                    QEMU_NET_PACKET_FLAG_NONE,
847                                    iov, iovcnt, sent_cb);
848 }
849 
850 ssize_t
851 qemu_sendv_packet(NetClientState *nc, const struct iovec *iov, int iovcnt)
852 {
853     return qemu_sendv_packet_async(nc, iov, iovcnt, NULL);
854 }
855 
856 NetClientState *qemu_find_netdev(const char *id)
857 {
858     NetClientState *nc;
859 
860     QTAILQ_FOREACH(nc, &net_clients, next) {
861         if (nc->info->type == NET_CLIENT_DRIVER_NIC)
862             continue;
863         if (!strcmp(nc->name, id)) {
864             return nc;
865         }
866     }
867 
868     return NULL;
869 }
870 
871 int qemu_find_net_clients_except(const char *id, NetClientState **ncs,
872                                  NetClientDriver type, int max)
873 {
874     NetClientState *nc;
875     int ret = 0;
876 
877     QTAILQ_FOREACH(nc, &net_clients, next) {
878         if (nc->info->type == type) {
879             continue;
880         }
881         if (!id || !strcmp(nc->name, id)) {
882             if (ret < max) {
883                 ncs[ret] = nc;
884             }
885             ret++;
886         }
887     }
888 
889     return ret;
890 }
891 
892 static int nic_get_free_idx(void)
893 {
894     int index;
895 
896     for (index = 0; index < MAX_NICS; index++)
897         if (!nd_table[index].used)
898             return index;
899     return -1;
900 }
901 
902 int qemu_show_nic_models(const char *arg, const char *const *models)
903 {
904     int i;
905 
906     if (!arg || !is_help_option(arg)) {
907         return 0;
908     }
909 
910     printf("Supported NIC models:\n");
911     for (i = 0 ; models[i]; i++) {
912         printf("%s\n", models[i]);
913     }
914     return 1;
915 }
916 
917 void qemu_check_nic_model(NICInfo *nd, const char *model)
918 {
919     const char *models[2];
920 
921     models[0] = model;
922     models[1] = NULL;
923 
924     if (qemu_show_nic_models(nd->model, models))
925         exit(0);
926     if (qemu_find_nic_model(nd, models, model) < 0)
927         exit(1);
928 }
929 
930 int qemu_find_nic_model(NICInfo *nd, const char * const *models,
931                         const char *default_model)
932 {
933     int i;
934 
935     if (!nd->model)
936         nd->model = g_strdup(default_model);
937 
938     for (i = 0 ; models[i]; i++) {
939         if (strcmp(nd->model, models[i]) == 0)
940             return i;
941     }
942 
943     error_report("Unsupported NIC model: %s", nd->model);
944     return -1;
945 }
946 
947 static int net_init_nic(const Netdev *netdev, const char *name,
948                         NetClientState *peer, Error **errp)
949 {
950     int idx;
951     NICInfo *nd;
952     const NetLegacyNicOptions *nic;
953 
954     assert(netdev->type == NET_CLIENT_DRIVER_NIC);
955     nic = &netdev->u.nic;
956 
957     idx = nic_get_free_idx();
958     if (idx == -1 || nb_nics >= MAX_NICS) {
959         error_setg(errp, "too many NICs");
960         return -1;
961     }
962 
963     nd = &nd_table[idx];
964 
965     memset(nd, 0, sizeof(*nd));
966 
967     if (nic->netdev) {
968         nd->netdev = qemu_find_netdev(nic->netdev);
969         if (!nd->netdev) {
970             error_setg(errp, "netdev '%s' not found", nic->netdev);
971             return -1;
972         }
973     } else {
974         assert(peer);
975         nd->netdev = peer;
976     }
977     nd->name = g_strdup(name);
978     if (nic->model) {
979         nd->model = g_strdup(nic->model);
980     }
981     if (nic->addr) {
982         nd->devaddr = g_strdup(nic->addr);
983     }
984 
985     if (nic->macaddr &&
986         net_parse_macaddr(nd->macaddr.a, nic->macaddr) < 0) {
987         error_setg(errp, "invalid syntax for ethernet address");
988         return -1;
989     }
990     if (nic->macaddr &&
991         is_multicast_ether_addr(nd->macaddr.a)) {
992         error_setg(errp,
993                    "NIC cannot have multicast MAC address (odd 1st byte)");
994         return -1;
995     }
996     qemu_macaddr_default_if_unset(&nd->macaddr);
997 
998     if (nic->has_vectors) {
999         if (nic->vectors > 0x7ffffff) {
1000             error_setg(errp, "invalid # of vectors: %"PRIu32, nic->vectors);
1001             return -1;
1002         }
1003         nd->nvectors = nic->vectors;
1004     } else {
1005         nd->nvectors = DEV_NVECTORS_UNSPECIFIED;
1006     }
1007 
1008     nd->used = 1;
1009     nb_nics++;
1010 
1011     return idx;
1012 }
1013 
1014 
1015 static int (* const net_client_init_fun[NET_CLIENT_DRIVER__MAX])(
1016     const Netdev *netdev,
1017     const char *name,
1018     NetClientState *peer, Error **errp) = {
1019         [NET_CLIENT_DRIVER_NIC]       = net_init_nic,
1020 #ifdef CONFIG_SLIRP
1021         [NET_CLIENT_DRIVER_USER]      = net_init_slirp,
1022 #endif
1023         [NET_CLIENT_DRIVER_TAP]       = net_init_tap,
1024         [NET_CLIENT_DRIVER_SOCKET]    = net_init_socket,
1025         [NET_CLIENT_DRIVER_STREAM]    = net_init_stream,
1026         [NET_CLIENT_DRIVER_DGRAM]     = net_init_dgram,
1027 #ifdef CONFIG_VDE
1028         [NET_CLIENT_DRIVER_VDE]       = net_init_vde,
1029 #endif
1030 #ifdef CONFIG_NETMAP
1031         [NET_CLIENT_DRIVER_NETMAP]    = net_init_netmap,
1032 #endif
1033 #ifdef CONFIG_NET_BRIDGE
1034         [NET_CLIENT_DRIVER_BRIDGE]    = net_init_bridge,
1035 #endif
1036         [NET_CLIENT_DRIVER_HUBPORT]   = net_init_hubport,
1037 #ifdef CONFIG_VHOST_NET_USER
1038         [NET_CLIENT_DRIVER_VHOST_USER] = net_init_vhost_user,
1039 #endif
1040 #ifdef CONFIG_VHOST_NET_VDPA
1041         [NET_CLIENT_DRIVER_VHOST_VDPA] = net_init_vhost_vdpa,
1042 #endif
1043 #ifdef CONFIG_L2TPV3
1044         [NET_CLIENT_DRIVER_L2TPV3]    = net_init_l2tpv3,
1045 #endif
1046 #ifdef CONFIG_VMNET
1047         [NET_CLIENT_DRIVER_VMNET_HOST] = net_init_vmnet_host,
1048         [NET_CLIENT_DRIVER_VMNET_SHARED] = net_init_vmnet_shared,
1049         [NET_CLIENT_DRIVER_VMNET_BRIDGED] = net_init_vmnet_bridged,
1050 #endif /* CONFIG_VMNET */
1051 };
1052 
1053 
1054 static int net_client_init1(const Netdev *netdev, bool is_netdev, Error **errp)
1055 {
1056     NetClientState *peer = NULL;
1057     NetClientState *nc;
1058 
1059     if (is_netdev) {
1060         if (netdev->type == NET_CLIENT_DRIVER_NIC ||
1061             !net_client_init_fun[netdev->type]) {
1062             error_setg(errp, "network backend '%s' is not compiled into this binary",
1063                        NetClientDriver_str(netdev->type));
1064             return -1;
1065         }
1066     } else {
1067         if (netdev->type == NET_CLIENT_DRIVER_NONE) {
1068             return 0; /* nothing to do */
1069         }
1070         if (netdev->type == NET_CLIENT_DRIVER_HUBPORT) {
1071             error_setg(errp, "network backend '%s' is only supported with -netdev/-nic",
1072                        NetClientDriver_str(netdev->type));
1073             return -1;
1074         }
1075 
1076         if (!net_client_init_fun[netdev->type]) {
1077             error_setg(errp, "network backend '%s' is not compiled into this binary",
1078                        NetClientDriver_str(netdev->type));
1079             return -1;
1080         }
1081 
1082         /* Do not add to a hub if it's a nic with a netdev= parameter. */
1083         if (netdev->type != NET_CLIENT_DRIVER_NIC ||
1084             !netdev->u.nic.netdev) {
1085             peer = net_hub_add_port(0, NULL, NULL);
1086         }
1087     }
1088 
1089     nc = qemu_find_netdev(netdev->id);
1090     if (nc) {
1091         error_setg(errp, "Duplicate ID '%s'", netdev->id);
1092         return -1;
1093     }
1094 
1095     if (net_client_init_fun[netdev->type](netdev, netdev->id, peer, errp) < 0) {
1096         /* FIXME drop when all init functions store an Error */
1097         if (errp && !*errp) {
1098             error_setg(errp, "Device '%s' could not be initialized",
1099                        NetClientDriver_str(netdev->type));
1100         }
1101         return -1;
1102     }
1103 
1104     if (is_netdev) {
1105         nc = qemu_find_netdev(netdev->id);
1106         assert(nc);
1107         nc->is_netdev = true;
1108     }
1109 
1110     return 0;
1111 }
1112 
1113 void show_netdevs(void)
1114 {
1115     int idx;
1116     const char *available_netdevs[] = {
1117         "socket",
1118         "stream",
1119         "dgram",
1120         "hubport",
1121         "tap",
1122 #ifdef CONFIG_SLIRP
1123         "user",
1124 #endif
1125 #ifdef CONFIG_L2TPV3
1126         "l2tpv3",
1127 #endif
1128 #ifdef CONFIG_VDE
1129         "vde",
1130 #endif
1131 #ifdef CONFIG_NET_BRIDGE
1132         "bridge",
1133 #endif
1134 #ifdef CONFIG_NETMAP
1135         "netmap",
1136 #endif
1137 #ifdef CONFIG_POSIX
1138         "vhost-user",
1139 #endif
1140 #ifdef CONFIG_VHOST_VDPA
1141         "vhost-vdpa",
1142 #endif
1143 #ifdef CONFIG_VMNET
1144         "vmnet-host",
1145         "vmnet-shared",
1146         "vmnet-bridged",
1147 #endif
1148     };
1149 
1150     qemu_printf("Available netdev backend types:\n");
1151     for (idx = 0; idx < ARRAY_SIZE(available_netdevs); idx++) {
1152         qemu_printf("%s\n", available_netdevs[idx]);
1153     }
1154 }
1155 
1156 static int net_client_init(QemuOpts *opts, bool is_netdev, Error **errp)
1157 {
1158     gchar **substrings = NULL;
1159     Netdev *object = NULL;
1160     int ret = -1;
1161     Visitor *v = opts_visitor_new(opts);
1162 
1163     /* Parse convenience option format ip6-net=fec0::0[/64] */
1164     const char *ip6_net = qemu_opt_get(opts, "ipv6-net");
1165 
1166     if (ip6_net) {
1167         char *prefix_addr;
1168         unsigned long prefix_len = 64; /* Default 64bit prefix length. */
1169 
1170         substrings = g_strsplit(ip6_net, "/", 2);
1171         if (!substrings || !substrings[0]) {
1172             error_setg(errp, QERR_INVALID_PARAMETER_VALUE, "ipv6-net",
1173                        "a valid IPv6 prefix");
1174             goto out;
1175         }
1176 
1177         prefix_addr = substrings[0];
1178 
1179         /* Handle user-specified prefix length. */
1180         if (substrings[1] &&
1181             qemu_strtoul(substrings[1], NULL, 10, &prefix_len))
1182         {
1183             error_setg(errp, QERR_INVALID_PARAMETER_VALUE,
1184                        "ipv6-prefixlen", "a number");
1185             goto out;
1186         }
1187 
1188         qemu_opt_set(opts, "ipv6-prefix", prefix_addr, &error_abort);
1189         qemu_opt_set_number(opts, "ipv6-prefixlen", prefix_len,
1190                             &error_abort);
1191         qemu_opt_unset(opts, "ipv6-net");
1192     }
1193 
1194     /* Create an ID for -net if the user did not specify one */
1195     if (!is_netdev && !qemu_opts_id(opts)) {
1196         qemu_opts_set_id(opts, id_generate(ID_NET));
1197     }
1198 
1199     if (visit_type_Netdev(v, NULL, &object, errp)) {
1200         ret = net_client_init1(object, is_netdev, errp);
1201     }
1202 
1203     qapi_free_Netdev(object);
1204 
1205 out:
1206     g_strfreev(substrings);
1207     visit_free(v);
1208     return ret;
1209 }
1210 
1211 void netdev_add(QemuOpts *opts, Error **errp)
1212 {
1213     net_client_init(opts, true, errp);
1214 }
1215 
1216 void qmp_netdev_add(Netdev *netdev, Error **errp)
1217 {
1218     if (!id_wellformed(netdev->id)) {
1219         error_setg(errp, QERR_INVALID_PARAMETER_VALUE, "id", "an identifier");
1220         return;
1221     }
1222 
1223     net_client_init1(netdev, true, errp);
1224 }
1225 
1226 void qmp_netdev_del(const char *id, Error **errp)
1227 {
1228     NetClientState *nc;
1229     QemuOpts *opts;
1230 
1231     nc = qemu_find_netdev(id);
1232     if (!nc) {
1233         error_set(errp, ERROR_CLASS_DEVICE_NOT_FOUND,
1234                   "Device '%s' not found", id);
1235         return;
1236     }
1237 
1238     if (!nc->is_netdev) {
1239         error_setg(errp, "Device '%s' is not a netdev", id);
1240         return;
1241     }
1242 
1243     qemu_del_net_client(nc);
1244 
1245     /*
1246      * Wart: we need to delete the QemuOpts associated with netdevs
1247      * created via CLI or HMP, to avoid bogus "Duplicate ID" errors in
1248      * HMP netdev_add.
1249      */
1250     opts = qemu_opts_find(qemu_find_opts("netdev"), id);
1251     if (opts) {
1252         qemu_opts_del(opts);
1253     }
1254 }
1255 
1256 static void netfilter_print_info(Monitor *mon, NetFilterState *nf)
1257 {
1258     char *str;
1259     ObjectProperty *prop;
1260     ObjectPropertyIterator iter;
1261     Visitor *v;
1262 
1263     /* generate info str */
1264     object_property_iter_init(&iter, OBJECT(nf));
1265     while ((prop = object_property_iter_next(&iter))) {
1266         if (!strcmp(prop->name, "type")) {
1267             continue;
1268         }
1269         v = string_output_visitor_new(false, &str);
1270         object_property_get(OBJECT(nf), prop->name, v, NULL);
1271         visit_complete(v, &str);
1272         visit_free(v);
1273         monitor_printf(mon, ",%s=%s", prop->name, str);
1274         g_free(str);
1275     }
1276     monitor_printf(mon, "\n");
1277 }
1278 
1279 void print_net_client(Monitor *mon, NetClientState *nc)
1280 {
1281     NetFilterState *nf;
1282 
1283     monitor_printf(mon, "%s: index=%d,type=%s,%s\n", nc->name,
1284                    nc->queue_index,
1285                    NetClientDriver_str(nc->info->type),
1286                    nc->info_str);
1287     if (!QTAILQ_EMPTY(&nc->filters)) {
1288         monitor_printf(mon, "filters:\n");
1289     }
1290     QTAILQ_FOREACH(nf, &nc->filters, next) {
1291         monitor_printf(mon, "  - %s: type=%s",
1292                        object_get_canonical_path_component(OBJECT(nf)),
1293                        object_get_typename(OBJECT(nf)));
1294         netfilter_print_info(mon, nf);
1295     }
1296 }
1297 
1298 RxFilterInfoList *qmp_query_rx_filter(const char *name, Error **errp)
1299 {
1300     NetClientState *nc;
1301     RxFilterInfoList *filter_list = NULL, **tail = &filter_list;
1302 
1303     QTAILQ_FOREACH(nc, &net_clients, next) {
1304         RxFilterInfo *info;
1305 
1306         if (name && strcmp(nc->name, name) != 0) {
1307             continue;
1308         }
1309 
1310         /* only query rx-filter information of NIC */
1311         if (nc->info->type != NET_CLIENT_DRIVER_NIC) {
1312             if (name) {
1313                 error_setg(errp, "net client(%s) isn't a NIC", name);
1314                 assert(!filter_list);
1315                 return NULL;
1316             }
1317             continue;
1318         }
1319 
1320         /* only query information on queue 0 since the info is per nic,
1321          * not per queue
1322          */
1323         if (nc->queue_index != 0)
1324             continue;
1325 
1326         if (nc->info->query_rx_filter) {
1327             info = nc->info->query_rx_filter(nc);
1328             QAPI_LIST_APPEND(tail, info);
1329         } else if (name) {
1330             error_setg(errp, "net client(%s) doesn't support"
1331                        " rx-filter querying", name);
1332             assert(!filter_list);
1333             return NULL;
1334         }
1335 
1336         if (name) {
1337             break;
1338         }
1339     }
1340 
1341     if (filter_list == NULL && name) {
1342         error_setg(errp, "invalid net client name: %s", name);
1343     }
1344 
1345     return filter_list;
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     /*cleanup colo compare module for COLO*/
1438     colo_compare_cleanup();
1439 
1440     /* We may del multiple entries during qemu_del_net_client(),
1441      * so QTAILQ_FOREACH_SAFE() is also not safe here.
1442      */
1443     while (!QTAILQ_EMPTY(&net_clients)) {
1444         nc = QTAILQ_FIRST(&net_clients);
1445         if (nc->info->type == NET_CLIENT_DRIVER_NIC) {
1446             qemu_del_nic(qemu_get_nic(nc));
1447         } else {
1448             qemu_del_net_client(nc);
1449         }
1450     }
1451 
1452     qemu_del_vm_change_state_handler(net_change_state_entry);
1453 }
1454 
1455 void net_check_clients(void)
1456 {
1457     NetClientState *nc;
1458     int i;
1459 
1460     net_hub_check_clients();
1461 
1462     QTAILQ_FOREACH(nc, &net_clients, next) {
1463         if (!nc->peer) {
1464             warn_report("%s %s has no peer",
1465                         nc->info->type == NET_CLIENT_DRIVER_NIC
1466                         ? "nic" : "netdev",
1467                         nc->name);
1468         }
1469     }
1470 
1471     /* Check that all NICs requested via -net nic actually got created.
1472      * NICs created via -device don't need to be checked here because
1473      * they are always instantiated.
1474      */
1475     for (i = 0; i < MAX_NICS; i++) {
1476         NICInfo *nd = &nd_table[i];
1477         if (nd->used && !nd->instantiated) {
1478             warn_report("requested NIC (%s, model %s) "
1479                         "was not created (not supported by this machine?)",
1480                         nd->name ? nd->name : "anonymous",
1481                         nd->model ? nd->model : "unspecified");
1482         }
1483     }
1484 }
1485 
1486 static int net_init_client(void *dummy, QemuOpts *opts, Error **errp)
1487 {
1488     return net_client_init(opts, false, errp);
1489 }
1490 
1491 static int net_init_netdev(void *dummy, QemuOpts *opts, Error **errp)
1492 {
1493     const char *type = qemu_opt_get(opts, "type");
1494 
1495     if (type && is_help_option(type)) {
1496         show_netdevs();
1497         exit(0);
1498     }
1499     return net_client_init(opts, true, errp);
1500 }
1501 
1502 /* For the convenience "--nic" parameter */
1503 static int net_param_nic(void *dummy, QemuOpts *opts, Error **errp)
1504 {
1505     char *mac, *nd_id;
1506     int idx, ret;
1507     NICInfo *ni;
1508     const char *type;
1509 
1510     type = qemu_opt_get(opts, "type");
1511     if (type && g_str_equal(type, "none")) {
1512         return 0;    /* Nothing to do, default_net is cleared in vl.c */
1513     }
1514 
1515     idx = nic_get_free_idx();
1516     if (idx == -1 || nb_nics >= MAX_NICS) {
1517         error_setg(errp, "no more on-board/default NIC slots available");
1518         return -1;
1519     }
1520 
1521     if (!type) {
1522         qemu_opt_set(opts, "type", "user", &error_abort);
1523     }
1524 
1525     ni = &nd_table[idx];
1526     memset(ni, 0, sizeof(*ni));
1527     ni->model = qemu_opt_get_del(opts, "model");
1528 
1529     /* Create an ID if the user did not specify one */
1530     nd_id = g_strdup(qemu_opts_id(opts));
1531     if (!nd_id) {
1532         nd_id = id_generate(ID_NET);
1533         qemu_opts_set_id(opts, nd_id);
1534     }
1535 
1536     /* Handle MAC address */
1537     mac = qemu_opt_get_del(opts, "mac");
1538     if (mac) {
1539         ret = net_parse_macaddr(ni->macaddr.a, mac);
1540         g_free(mac);
1541         if (ret) {
1542             error_setg(errp, "invalid syntax for ethernet address");
1543             goto out;
1544         }
1545         if (is_multicast_ether_addr(ni->macaddr.a)) {
1546             error_setg(errp, "NIC cannot have multicast MAC address");
1547             ret = -1;
1548             goto out;
1549         }
1550     }
1551     qemu_macaddr_default_if_unset(&ni->macaddr);
1552 
1553     ret = net_client_init(opts, true, errp);
1554     if (ret == 0) {
1555         ni->netdev = qemu_find_netdev(nd_id);
1556         ni->used = true;
1557         nb_nics++;
1558     }
1559 
1560 out:
1561     g_free(nd_id);
1562     return ret;
1563 }
1564 
1565 static void netdev_init_modern(void)
1566 {
1567     while (!QSIMPLEQ_EMPTY(&nd_queue)) {
1568         NetdevQueueEntry *nd = QSIMPLEQ_FIRST(&nd_queue);
1569 
1570         QSIMPLEQ_REMOVE_HEAD(&nd_queue, entry);
1571         loc_push_restore(&nd->loc);
1572         net_client_init1(nd->nd, true, &error_fatal);
1573         loc_pop(&nd->loc);
1574         qapi_free_Netdev(nd->nd);
1575         g_free(nd);
1576     }
1577 }
1578 
1579 void net_init_clients(void)
1580 {
1581     net_change_state_entry =
1582         qemu_add_vm_change_state_handler(net_vm_change_state_handler, NULL);
1583 
1584     QTAILQ_INIT(&net_clients);
1585 
1586     netdev_init_modern();
1587 
1588     qemu_opts_foreach(qemu_find_opts("netdev"), net_init_netdev, NULL,
1589                       &error_fatal);
1590 
1591     qemu_opts_foreach(qemu_find_opts("nic"), net_param_nic, NULL,
1592                       &error_fatal);
1593 
1594     qemu_opts_foreach(qemu_find_opts("net"), net_init_client, NULL,
1595                       &error_fatal);
1596 }
1597 
1598 /*
1599  * Does this -netdev argument use modern rather than traditional syntax?
1600  * Modern syntax is to be parsed with netdev_parse_modern().
1601  * Traditional syntax is to be parsed with net_client_parse().
1602  */
1603 bool netdev_is_modern(const char *optarg)
1604 {
1605     QemuOpts *opts;
1606     bool is_modern;
1607     const char *type;
1608     static QemuOptsList dummy_opts = {
1609         .name = "netdev",
1610         .implied_opt_name = "type",
1611         .head = QTAILQ_HEAD_INITIALIZER(dummy_opts.head),
1612         .desc = { { } },
1613     };
1614 
1615     if (optarg[0] == '{') {
1616         /* This is JSON, which means it's modern syntax */
1617         return true;
1618     }
1619 
1620     opts = qemu_opts_create(&dummy_opts, NULL, false, &error_abort);
1621     qemu_opts_do_parse(opts, optarg, dummy_opts.implied_opt_name,
1622                        &error_abort);
1623     type = qemu_opt_get(opts, "type");
1624     is_modern = !g_strcmp0(type, "stream") || !g_strcmp0(type, "dgram");
1625 
1626     qemu_opts_reset(&dummy_opts);
1627 
1628     return is_modern;
1629 }
1630 
1631 /*
1632  * netdev_parse_modern() uses modern, more expressive syntax than
1633  * net_client_parse(), but supports only the -netdev option.
1634  * netdev_parse_modern() appends to @nd_queue, whereas net_client_parse()
1635  * appends to @qemu_netdev_opts.
1636  */
1637 void netdev_parse_modern(const char *optarg)
1638 {
1639     Visitor *v;
1640     NetdevQueueEntry *nd;
1641 
1642     v = qobject_input_visitor_new_str(optarg, "type", &error_fatal);
1643     nd = g_new(NetdevQueueEntry, 1);
1644     visit_type_Netdev(v, NULL, &nd->nd, &error_fatal);
1645     visit_free(v);
1646     loc_save(&nd->loc);
1647 
1648     QSIMPLEQ_INSERT_TAIL(&nd_queue, nd, entry);
1649 }
1650 
1651 void net_client_parse(QemuOptsList *opts_list, const char *optarg)
1652 {
1653     if (!qemu_opts_parse_noisily(opts_list, optarg, true)) {
1654         exit(1);
1655     }
1656 }
1657 
1658 /* From FreeBSD */
1659 /* XXX: optimize */
1660 uint32_t net_crc32(const uint8_t *p, int len)
1661 {
1662     uint32_t crc;
1663     int carry, i, j;
1664     uint8_t b;
1665 
1666     crc = 0xffffffff;
1667     for (i = 0; i < len; i++) {
1668         b = *p++;
1669         for (j = 0; j < 8; j++) {
1670             carry = ((crc & 0x80000000L) ? 1 : 0) ^ (b & 0x01);
1671             crc <<= 1;
1672             b >>= 1;
1673             if (carry) {
1674                 crc = ((crc ^ POLYNOMIAL_BE) | carry);
1675             }
1676         }
1677     }
1678 
1679     return crc;
1680 }
1681 
1682 uint32_t net_crc32_le(const uint8_t *p, int len)
1683 {
1684     uint32_t crc;
1685     int carry, i, j;
1686     uint8_t b;
1687 
1688     crc = 0xffffffff;
1689     for (i = 0; i < len; i++) {
1690         b = *p++;
1691         for (j = 0; j < 8; j++) {
1692             carry = (crc & 0x1) ^ (b & 0x01);
1693             crc >>= 1;
1694             b >>= 1;
1695             if (carry) {
1696                 crc ^= POLYNOMIAL_LE;
1697             }
1698         }
1699     }
1700 
1701     return crc;
1702 }
1703 
1704 QemuOptsList qemu_netdev_opts = {
1705     .name = "netdev",
1706     .implied_opt_name = "type",
1707     .head = QTAILQ_HEAD_INITIALIZER(qemu_netdev_opts.head),
1708     .desc = {
1709         /*
1710          * no elements => accept any params
1711          * validation will happen later
1712          */
1713         { /* end of list */ }
1714     },
1715 };
1716 
1717 QemuOptsList qemu_nic_opts = {
1718     .name = "nic",
1719     .implied_opt_name = "type",
1720     .head = QTAILQ_HEAD_INITIALIZER(qemu_nic_opts.head),
1721     .desc = {
1722         /*
1723          * no elements => accept any params
1724          * validation will happen later
1725          */
1726         { /* end of list */ }
1727     },
1728 };
1729 
1730 QemuOptsList qemu_net_opts = {
1731     .name = "net",
1732     .implied_opt_name = "type",
1733     .head = QTAILQ_HEAD_INITIALIZER(qemu_net_opts.head),
1734     .desc = {
1735         /*
1736          * no elements => accept any params
1737          * validation will happen later
1738          */
1739         { /* end of list */ }
1740     },
1741 };
1742 
1743 void net_socket_rs_init(SocketReadState *rs,
1744                         SocketReadStateFinalize *finalize,
1745                         bool vnet_hdr)
1746 {
1747     rs->state = 0;
1748     rs->vnet_hdr = vnet_hdr;
1749     rs->index = 0;
1750     rs->packet_len = 0;
1751     rs->vnet_hdr_len = 0;
1752     memset(rs->buf, 0, sizeof(rs->buf));
1753     rs->finalize = finalize;
1754 }
1755 
1756 /*
1757  * Returns
1758  * 0: success
1759  * -1: error occurs
1760  */
1761 int net_fill_rstate(SocketReadState *rs, const uint8_t *buf, int size)
1762 {
1763     unsigned int l;
1764 
1765     while (size > 0) {
1766         /* Reassemble a packet from the network.
1767          * 0 = getting length.
1768          * 1 = getting vnet header length.
1769          * 2 = getting data.
1770          */
1771         switch (rs->state) {
1772         case 0:
1773             l = 4 - rs->index;
1774             if (l > size) {
1775                 l = size;
1776             }
1777             memcpy(rs->buf + rs->index, buf, l);
1778             buf += l;
1779             size -= l;
1780             rs->index += l;
1781             if (rs->index == 4) {
1782                 /* got length */
1783                 rs->packet_len = ntohl(*(uint32_t *)rs->buf);
1784                 rs->index = 0;
1785                 if (rs->vnet_hdr) {
1786                     rs->state = 1;
1787                 } else {
1788                     rs->state = 2;
1789                     rs->vnet_hdr_len = 0;
1790                 }
1791             }
1792             break;
1793         case 1:
1794             l = 4 - rs->index;
1795             if (l > size) {
1796                 l = size;
1797             }
1798             memcpy(rs->buf + rs->index, buf, l);
1799             buf += l;
1800             size -= l;
1801             rs->index += l;
1802             if (rs->index == 4) {
1803                 /* got vnet header length */
1804                 rs->vnet_hdr_len = ntohl(*(uint32_t *)rs->buf);
1805                 rs->index = 0;
1806                 rs->state = 2;
1807             }
1808             break;
1809         case 2:
1810             l = rs->packet_len - rs->index;
1811             if (l > size) {
1812                 l = size;
1813             }
1814             if (rs->index + l <= sizeof(rs->buf)) {
1815                 memcpy(rs->buf + rs->index, buf, l);
1816             } else {
1817                 fprintf(stderr, "serious error: oversized packet received,"
1818                     "connection terminated.\n");
1819                 rs->index = rs->state = 0;
1820                 return -1;
1821             }
1822 
1823             rs->index += l;
1824             buf += l;
1825             size -= l;
1826             if (rs->index >= rs->packet_len) {
1827                 rs->index = 0;
1828                 rs->state = 0;
1829                 assert(rs->finalize);
1830                 rs->finalize(rs);
1831             }
1832             break;
1833         }
1834     }
1835 
1836     assert(size == 0);
1837     return 0;
1838 }
1839