xref: /openbmc/qemu/net/net.c (revision 9a48e367)
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 #include "qemu/osdep.h"
25 
26 #include "net/net.h"
27 #include "clients.h"
28 #include "hub.h"
29 #include "net/slirp.h"
30 #include "net/eth.h"
31 #include "util.h"
32 
33 #include "monitor/monitor.h"
34 #include "qemu-common.h"
35 #include "qemu/help_option.h"
36 #include "qapi/qmp/qerror.h"
37 #include "qemu/error-report.h"
38 #include "qemu/sockets.h"
39 #include "qemu/cutils.h"
40 #include "qemu/config-file.h"
41 #include "qmp-commands.h"
42 #include "hw/qdev.h"
43 #include "qemu/iov.h"
44 #include "qemu/main-loop.h"
45 #include "qapi-visit.h"
46 #include "qapi/opts-visitor.h"
47 #include "sysemu/sysemu.h"
48 #include "net/filter.h"
49 #include "qapi/string-output-visitor.h"
50 
51 /* Net bridge is currently not supported for W32. */
52 #if !defined(_WIN32)
53 # define CONFIG_NET_BRIDGE
54 #endif
55 
56 static VMChangeStateEntry *net_change_state_entry;
57 static QTAILQ_HEAD(, NetClientState) net_clients;
58 
59 const char *host_net_devices[] = {
60     "tap",
61     "socket",
62     "dump",
63 #ifdef CONFIG_NET_BRIDGE
64     "bridge",
65 #endif
66 #ifdef CONFIG_NETMAP
67     "netmap",
68 #endif
69 #ifdef CONFIG_SLIRP
70     "user",
71 #endif
72 #ifdef CONFIG_VDE
73     "vde",
74 #endif
75     "vhost-user",
76     NULL,
77 };
78 
79 /***********************************************************/
80 /* network device redirectors */
81 
82 static int get_str_sep(char *buf, int buf_size, const char **pp, int sep)
83 {
84     const char *p, *p1;
85     int len;
86     p = *pp;
87     p1 = strchr(p, sep);
88     if (!p1)
89         return -1;
90     len = p1 - p;
91     p1++;
92     if (buf_size > 0) {
93         if (len > buf_size - 1)
94             len = buf_size - 1;
95         memcpy(buf, p, len);
96         buf[len] = '\0';
97     }
98     *pp = p1;
99     return 0;
100 }
101 
102 int parse_host_port(struct sockaddr_in *saddr, const char *str)
103 {
104     char buf[512];
105     struct hostent *he;
106     const char *p, *r;
107     int port;
108 
109     p = str;
110     if (get_str_sep(buf, sizeof(buf), &p, ':') < 0)
111         return -1;
112     saddr->sin_family = AF_INET;
113     if (buf[0] == '\0') {
114         saddr->sin_addr.s_addr = 0;
115     } else {
116         if (qemu_isdigit(buf[0])) {
117             if (!inet_aton(buf, &saddr->sin_addr))
118                 return -1;
119         } else {
120             if ((he = gethostbyname(buf)) == NULL)
121                 return - 1;
122             saddr->sin_addr = *(struct in_addr *)he->h_addr;
123         }
124     }
125     port = strtol(p, (char **)&r, 0);
126     if (r == p)
127         return -1;
128     saddr->sin_port = htons(port);
129     return 0;
130 }
131 
132 char *qemu_mac_strdup_printf(const uint8_t *macaddr)
133 {
134     return g_strdup_printf("%.2x:%.2x:%.2x:%.2x:%.2x:%.2x",
135                            macaddr[0], macaddr[1], macaddr[2],
136                            macaddr[3], macaddr[4], macaddr[5]);
137 }
138 
139 void qemu_format_nic_info_str(NetClientState *nc, uint8_t macaddr[6])
140 {
141     snprintf(nc->info_str, sizeof(nc->info_str),
142              "model=%s,macaddr=%02x:%02x:%02x:%02x:%02x:%02x",
143              nc->model,
144              macaddr[0], macaddr[1], macaddr[2],
145              macaddr[3], macaddr[4], macaddr[5]);
146 }
147 
148 static int mac_table[256] = {0};
149 
150 static void qemu_macaddr_set_used(MACAddr *macaddr)
151 {
152     int index;
153 
154     for (index = 0x56; index < 0xFF; index++) {
155         if (macaddr->a[5] == index) {
156             mac_table[index]++;
157         }
158     }
159 }
160 
161 static void qemu_macaddr_set_free(MACAddr *macaddr)
162 {
163     int index;
164     static const MACAddr base = { .a = { 0x52, 0x54, 0x00, 0x12, 0x34, 0 } };
165 
166     if (memcmp(macaddr->a, &base.a, (sizeof(base.a) - 1)) != 0) {
167         return;
168     }
169     for (index = 0x56; index < 0xFF; index++) {
170         if (macaddr->a[5] == index) {
171             mac_table[index]--;
172         }
173     }
174 }
175 
176 static int qemu_macaddr_get_free(void)
177 {
178     int index;
179 
180     for (index = 0x56; index < 0xFF; index++) {
181         if (mac_table[index] == 0) {
182             return index;
183         }
184     }
185 
186     return -1;
187 }
188 
189 void qemu_macaddr_default_if_unset(MACAddr *macaddr)
190 {
191     static const MACAddr zero = { .a = { 0,0,0,0,0,0 } };
192     static const MACAddr base = { .a = { 0x52, 0x54, 0x00, 0x12, 0x34, 0 } };
193 
194     if (memcmp(macaddr, &zero, sizeof(zero)) != 0) {
195         if (memcmp(macaddr->a, &base.a, (sizeof(base.a) - 1)) != 0) {
196             return;
197         } else {
198             qemu_macaddr_set_used(macaddr);
199             return;
200         }
201     }
202 
203     macaddr->a[0] = 0x52;
204     macaddr->a[1] = 0x54;
205     macaddr->a[2] = 0x00;
206     macaddr->a[3] = 0x12;
207     macaddr->a[4] = 0x34;
208     macaddr->a[5] = qemu_macaddr_get_free();
209     qemu_macaddr_set_used(macaddr);
210 }
211 
212 /**
213  * Generate a name for net client
214  *
215  * Only net clients created with the legacy -net option and NICs need this.
216  */
217 static char *assign_name(NetClientState *nc1, const char *model)
218 {
219     NetClientState *nc;
220     int id = 0;
221 
222     QTAILQ_FOREACH(nc, &net_clients, next) {
223         if (nc == nc1) {
224             continue;
225         }
226         if (strcmp(nc->model, model) == 0) {
227             id++;
228         }
229     }
230 
231     return g_strdup_printf("%s.%d", model, id);
232 }
233 
234 static void qemu_net_client_destructor(NetClientState *nc)
235 {
236     g_free(nc);
237 }
238 
239 static void qemu_net_client_setup(NetClientState *nc,
240                                   NetClientInfo *info,
241                                   NetClientState *peer,
242                                   const char *model,
243                                   const char *name,
244                                   NetClientDestructor *destructor)
245 {
246     nc->info = info;
247     nc->model = g_strdup(model);
248     if (name) {
249         nc->name = g_strdup(name);
250     } else {
251         nc->name = assign_name(nc, model);
252     }
253 
254     if (peer) {
255         assert(!peer->peer);
256         nc->peer = peer;
257         peer->peer = nc;
258     }
259     QTAILQ_INSERT_TAIL(&net_clients, nc, next);
260 
261     nc->incoming_queue = qemu_new_net_queue(qemu_deliver_packet_iov, nc);
262     nc->destructor = destructor;
263     QTAILQ_INIT(&nc->filters);
264 }
265 
266 NetClientState *qemu_new_net_client(NetClientInfo *info,
267                                     NetClientState *peer,
268                                     const char *model,
269                                     const char *name)
270 {
271     NetClientState *nc;
272 
273     assert(info->size >= sizeof(NetClientState));
274 
275     nc = g_malloc0(info->size);
276     qemu_net_client_setup(nc, info, peer, model, name,
277                           qemu_net_client_destructor);
278 
279     return nc;
280 }
281 
282 NICState *qemu_new_nic(NetClientInfo *info,
283                        NICConf *conf,
284                        const char *model,
285                        const char *name,
286                        void *opaque)
287 {
288     NetClientState **peers = conf->peers.ncs;
289     NICState *nic;
290     int i, queues = MAX(1, conf->peers.queues);
291 
292     assert(info->type == NET_CLIENT_OPTIONS_KIND_NIC);
293     assert(info->size >= sizeof(NICState));
294 
295     nic = g_malloc0(info->size + sizeof(NetClientState) * queues);
296     nic->ncs = (void *)nic + info->size;
297     nic->conf = conf;
298     nic->opaque = opaque;
299 
300     for (i = 0; i < queues; i++) {
301         qemu_net_client_setup(&nic->ncs[i], info, peers[i], model, name,
302                               NULL);
303         nic->ncs[i].queue_index = i;
304     }
305 
306     return nic;
307 }
308 
309 NetClientState *qemu_get_subqueue(NICState *nic, int queue_index)
310 {
311     return nic->ncs + queue_index;
312 }
313 
314 NetClientState *qemu_get_queue(NICState *nic)
315 {
316     return qemu_get_subqueue(nic, 0);
317 }
318 
319 NICState *qemu_get_nic(NetClientState *nc)
320 {
321     NetClientState *nc0 = nc - nc->queue_index;
322 
323     return (NICState *)((void *)nc0 - nc->info->size);
324 }
325 
326 void *qemu_get_nic_opaque(NetClientState *nc)
327 {
328     NICState *nic = qemu_get_nic(nc);
329 
330     return nic->opaque;
331 }
332 
333 static void qemu_cleanup_net_client(NetClientState *nc)
334 {
335     QTAILQ_REMOVE(&net_clients, nc, next);
336 
337     if (nc->info->cleanup) {
338         nc->info->cleanup(nc);
339     }
340 }
341 
342 static void qemu_free_net_client(NetClientState *nc)
343 {
344     if (nc->incoming_queue) {
345         qemu_del_net_queue(nc->incoming_queue);
346     }
347     if (nc->peer) {
348         nc->peer->peer = NULL;
349     }
350     g_free(nc->name);
351     g_free(nc->model);
352     if (nc->destructor) {
353         nc->destructor(nc);
354     }
355 }
356 
357 void qemu_del_net_client(NetClientState *nc)
358 {
359     NetClientState *ncs[MAX_QUEUE_NUM];
360     int queues, i;
361     NetFilterState *nf, *next;
362 
363     assert(nc->info->type != NET_CLIENT_OPTIONS_KIND_NIC);
364 
365     /* If the NetClientState belongs to a multiqueue backend, we will change all
366      * other NetClientStates also.
367      */
368     queues = qemu_find_net_clients_except(nc->name, ncs,
369                                           NET_CLIENT_OPTIONS_KIND_NIC,
370                                           MAX_QUEUE_NUM);
371     assert(queues != 0);
372 
373     QTAILQ_FOREACH_SAFE(nf, &nc->filters, next, next) {
374         object_unparent(OBJECT(nf));
375     }
376 
377     /* If there is a peer NIC, delete and cleanup client, but do not free. */
378     if (nc->peer && nc->peer->info->type == NET_CLIENT_OPTIONS_KIND_NIC) {
379         NICState *nic = qemu_get_nic(nc->peer);
380         if (nic->peer_deleted) {
381             return;
382         }
383         nic->peer_deleted = true;
384 
385         for (i = 0; i < queues; i++) {
386             ncs[i]->peer->link_down = true;
387         }
388 
389         if (nc->peer->info->link_status_changed) {
390             nc->peer->info->link_status_changed(nc->peer);
391         }
392 
393         for (i = 0; i < queues; i++) {
394             qemu_cleanup_net_client(ncs[i]);
395         }
396 
397         return;
398     }
399 
400     for (i = 0; i < queues; i++) {
401         qemu_cleanup_net_client(ncs[i]);
402         qemu_free_net_client(ncs[i]);
403     }
404 }
405 
406 void qemu_del_nic(NICState *nic)
407 {
408     int i, queues = MAX(nic->conf->peers.queues, 1);
409 
410     qemu_macaddr_set_free(&nic->conf->macaddr);
411 
412     /* If this is a peer NIC and peer has already been deleted, free it now. */
413     if (nic->peer_deleted) {
414         for (i = 0; i < queues; i++) {
415             qemu_free_net_client(qemu_get_subqueue(nic, i)->peer);
416         }
417     }
418 
419     for (i = queues - 1; i >= 0; i--) {
420         NetClientState *nc = qemu_get_subqueue(nic, i);
421 
422         qemu_cleanup_net_client(nc);
423         qemu_free_net_client(nc);
424     }
425 
426     g_free(nic);
427 }
428 
429 void qemu_foreach_nic(qemu_nic_foreach func, void *opaque)
430 {
431     NetClientState *nc;
432 
433     QTAILQ_FOREACH(nc, &net_clients, next) {
434         if (nc->info->type == NET_CLIENT_OPTIONS_KIND_NIC) {
435             if (nc->queue_index == 0) {
436                 func(qemu_get_nic(nc), opaque);
437             }
438         }
439     }
440 }
441 
442 bool qemu_has_ufo(NetClientState *nc)
443 {
444     if (!nc || !nc->info->has_ufo) {
445         return false;
446     }
447 
448     return nc->info->has_ufo(nc);
449 }
450 
451 bool qemu_has_vnet_hdr(NetClientState *nc)
452 {
453     if (!nc || !nc->info->has_vnet_hdr) {
454         return false;
455     }
456 
457     return nc->info->has_vnet_hdr(nc);
458 }
459 
460 bool qemu_has_vnet_hdr_len(NetClientState *nc, int len)
461 {
462     if (!nc || !nc->info->has_vnet_hdr_len) {
463         return false;
464     }
465 
466     return nc->info->has_vnet_hdr_len(nc, len);
467 }
468 
469 void qemu_using_vnet_hdr(NetClientState *nc, bool enable)
470 {
471     if (!nc || !nc->info->using_vnet_hdr) {
472         return;
473     }
474 
475     nc->info->using_vnet_hdr(nc, enable);
476 }
477 
478 void qemu_set_offload(NetClientState *nc, int csum, int tso4, int tso6,
479                           int ecn, int ufo)
480 {
481     if (!nc || !nc->info->set_offload) {
482         return;
483     }
484 
485     nc->info->set_offload(nc, csum, tso4, tso6, ecn, ufo);
486 }
487 
488 void qemu_set_vnet_hdr_len(NetClientState *nc, int len)
489 {
490     if (!nc || !nc->info->set_vnet_hdr_len) {
491         return;
492     }
493 
494     nc->info->set_vnet_hdr_len(nc, len);
495 }
496 
497 int qemu_set_vnet_le(NetClientState *nc, bool is_le)
498 {
499 #ifdef HOST_WORDS_BIGENDIAN
500     if (!nc || !nc->info->set_vnet_le) {
501         return -ENOSYS;
502     }
503 
504     return nc->info->set_vnet_le(nc, is_le);
505 #else
506     return 0;
507 #endif
508 }
509 
510 int qemu_set_vnet_be(NetClientState *nc, bool is_be)
511 {
512 #ifdef HOST_WORDS_BIGENDIAN
513     return 0;
514 #else
515     if (!nc || !nc->info->set_vnet_be) {
516         return -ENOSYS;
517     }
518 
519     return nc->info->set_vnet_be(nc, is_be);
520 #endif
521 }
522 
523 int qemu_can_send_packet(NetClientState *sender)
524 {
525     int vm_running = runstate_is_running();
526 
527     if (!vm_running) {
528         return 0;
529     }
530 
531     if (!sender->peer) {
532         return 1;
533     }
534 
535     if (sender->peer->receive_disabled) {
536         return 0;
537     } else if (sender->peer->info->can_receive &&
538                !sender->peer->info->can_receive(sender->peer)) {
539         return 0;
540     }
541     return 1;
542 }
543 
544 static ssize_t filter_receive_iov(NetClientState *nc,
545                                   NetFilterDirection direction,
546                                   NetClientState *sender,
547                                   unsigned flags,
548                                   const struct iovec *iov,
549                                   int iovcnt,
550                                   NetPacketSent *sent_cb)
551 {
552     ssize_t ret = 0;
553     NetFilterState *nf = NULL;
554 
555     if (direction == NET_FILTER_DIRECTION_TX) {
556         QTAILQ_FOREACH(nf, &nc->filters, next) {
557             ret = qemu_netfilter_receive(nf, direction, sender, flags, iov,
558                                          iovcnt, sent_cb);
559             if (ret) {
560                 return ret;
561             }
562         }
563     } else {
564         QTAILQ_FOREACH_REVERSE(nf, &nc->filters, NetFilterHead, next) {
565             ret = qemu_netfilter_receive(nf, direction, sender, flags, iov,
566                                          iovcnt, sent_cb);
567             if (ret) {
568                 return ret;
569             }
570         }
571     }
572 
573     return ret;
574 }
575 
576 static ssize_t filter_receive(NetClientState *nc,
577                               NetFilterDirection direction,
578                               NetClientState *sender,
579                               unsigned flags,
580                               const uint8_t *data,
581                               size_t size,
582                               NetPacketSent *sent_cb)
583 {
584     struct iovec iov = {
585         .iov_base = (void *)data,
586         .iov_len = size
587     };
588 
589     return filter_receive_iov(nc, direction, sender, flags, &iov, 1, sent_cb);
590 }
591 
592 void qemu_purge_queued_packets(NetClientState *nc)
593 {
594     if (!nc->peer) {
595         return;
596     }
597 
598     qemu_net_queue_purge(nc->peer->incoming_queue, nc);
599 }
600 
601 static
602 void qemu_flush_or_purge_queued_packets(NetClientState *nc, bool purge)
603 {
604     nc->receive_disabled = 0;
605 
606     if (nc->peer && nc->peer->info->type == NET_CLIENT_OPTIONS_KIND_HUBPORT) {
607         if (net_hub_flush(nc->peer)) {
608             qemu_notify_event();
609         }
610     }
611     if (qemu_net_queue_flush(nc->incoming_queue)) {
612         /* We emptied the queue successfully, signal to the IO thread to repoll
613          * the file descriptor (for tap, for example).
614          */
615         qemu_notify_event();
616     } else if (purge) {
617         /* Unable to empty the queue, purge remaining packets */
618         qemu_net_queue_purge(nc->incoming_queue, nc);
619     }
620 }
621 
622 void qemu_flush_queued_packets(NetClientState *nc)
623 {
624     qemu_flush_or_purge_queued_packets(nc, false);
625 }
626 
627 static ssize_t qemu_send_packet_async_with_flags(NetClientState *sender,
628                                                  unsigned flags,
629                                                  const uint8_t *buf, int size,
630                                                  NetPacketSent *sent_cb)
631 {
632     NetQueue *queue;
633     int ret;
634 
635 #ifdef DEBUG_NET
636     printf("qemu_send_packet_async:\n");
637     qemu_hexdump((const char *)buf, stdout, "net", size);
638 #endif
639 
640     if (sender->link_down || !sender->peer) {
641         return size;
642     }
643 
644     /* Let filters handle the packet first */
645     ret = filter_receive(sender, NET_FILTER_DIRECTION_TX,
646                          sender, flags, buf, size, sent_cb);
647     if (ret) {
648         return ret;
649     }
650 
651     ret = filter_receive(sender->peer, NET_FILTER_DIRECTION_RX,
652                          sender, flags, buf, size, sent_cb);
653     if (ret) {
654         return ret;
655     }
656 
657     queue = sender->peer->incoming_queue;
658 
659     return qemu_net_queue_send(queue, sender, flags, buf, size, sent_cb);
660 }
661 
662 ssize_t qemu_send_packet_async(NetClientState *sender,
663                                const uint8_t *buf, int size,
664                                NetPacketSent *sent_cb)
665 {
666     return qemu_send_packet_async_with_flags(sender, QEMU_NET_PACKET_FLAG_NONE,
667                                              buf, size, sent_cb);
668 }
669 
670 void qemu_send_packet(NetClientState *nc, const uint8_t *buf, int size)
671 {
672     qemu_send_packet_async(nc, buf, size, NULL);
673 }
674 
675 ssize_t qemu_send_packet_raw(NetClientState *nc, const uint8_t *buf, int size)
676 {
677     return qemu_send_packet_async_with_flags(nc, QEMU_NET_PACKET_FLAG_RAW,
678                                              buf, size, NULL);
679 }
680 
681 static ssize_t nc_sendv_compat(NetClientState *nc, const struct iovec *iov,
682                                int iovcnt, unsigned flags)
683 {
684     uint8_t *buf = NULL;
685     uint8_t *buffer;
686     size_t offset;
687     ssize_t ret;
688 
689     if (iovcnt == 1) {
690         buffer = iov[0].iov_base;
691         offset = iov[0].iov_len;
692     } else {
693         buf = g_new(uint8_t, NET_BUFSIZE);
694         buffer = buf;
695         offset = iov_to_buf(iov, iovcnt, 0, buf, NET_BUFSIZE);
696     }
697 
698     if (flags & QEMU_NET_PACKET_FLAG_RAW && nc->info->receive_raw) {
699         ret = nc->info->receive_raw(nc, buffer, offset);
700     } else {
701         ret = nc->info->receive(nc, buffer, offset);
702     }
703 
704     g_free(buf);
705     return ret;
706 }
707 
708 ssize_t qemu_deliver_packet_iov(NetClientState *sender,
709                                 unsigned flags,
710                                 const struct iovec *iov,
711                                 int iovcnt,
712                                 void *opaque)
713 {
714     NetClientState *nc = opaque;
715     int ret;
716 
717     if (nc->link_down) {
718         return iov_size(iov, iovcnt);
719     }
720 
721     if (nc->receive_disabled) {
722         return 0;
723     }
724 
725     if (nc->info->receive_iov && !(flags & QEMU_NET_PACKET_FLAG_RAW)) {
726         ret = nc->info->receive_iov(nc, iov, iovcnt);
727     } else {
728         ret = nc_sendv_compat(nc, iov, iovcnt, flags);
729     }
730 
731     if (ret == 0) {
732         nc->receive_disabled = 1;
733     }
734 
735     return ret;
736 }
737 
738 ssize_t qemu_sendv_packet_async(NetClientState *sender,
739                                 const struct iovec *iov, int iovcnt,
740                                 NetPacketSent *sent_cb)
741 {
742     NetQueue *queue;
743     int ret;
744 
745     if (sender->link_down || !sender->peer) {
746         return iov_size(iov, iovcnt);
747     }
748 
749     /* Let filters handle the packet first */
750     ret = filter_receive_iov(sender, NET_FILTER_DIRECTION_TX, sender,
751                              QEMU_NET_PACKET_FLAG_NONE, iov, iovcnt, sent_cb);
752     if (ret) {
753         return ret;
754     }
755 
756     ret = filter_receive_iov(sender->peer, NET_FILTER_DIRECTION_RX, sender,
757                              QEMU_NET_PACKET_FLAG_NONE, iov, iovcnt, sent_cb);
758     if (ret) {
759         return ret;
760     }
761 
762     queue = sender->peer->incoming_queue;
763 
764     return qemu_net_queue_send_iov(queue, sender,
765                                    QEMU_NET_PACKET_FLAG_NONE,
766                                    iov, iovcnt, sent_cb);
767 }
768 
769 ssize_t
770 qemu_sendv_packet(NetClientState *nc, const struct iovec *iov, int iovcnt)
771 {
772     return qemu_sendv_packet_async(nc, iov, iovcnt, NULL);
773 }
774 
775 NetClientState *qemu_find_netdev(const char *id)
776 {
777     NetClientState *nc;
778 
779     QTAILQ_FOREACH(nc, &net_clients, next) {
780         if (nc->info->type == NET_CLIENT_OPTIONS_KIND_NIC)
781             continue;
782         if (!strcmp(nc->name, id)) {
783             return nc;
784         }
785     }
786 
787     return NULL;
788 }
789 
790 int qemu_find_net_clients_except(const char *id, NetClientState **ncs,
791                                  NetClientOptionsKind type, int max)
792 {
793     NetClientState *nc;
794     int ret = 0;
795 
796     QTAILQ_FOREACH(nc, &net_clients, next) {
797         if (nc->info->type == type) {
798             continue;
799         }
800         if (!id || !strcmp(nc->name, id)) {
801             if (ret < max) {
802                 ncs[ret] = nc;
803             }
804             ret++;
805         }
806     }
807 
808     return ret;
809 }
810 
811 static int nic_get_free_idx(void)
812 {
813     int index;
814 
815     for (index = 0; index < MAX_NICS; index++)
816         if (!nd_table[index].used)
817             return index;
818     return -1;
819 }
820 
821 int qemu_show_nic_models(const char *arg, const char *const *models)
822 {
823     int i;
824 
825     if (!arg || !is_help_option(arg)) {
826         return 0;
827     }
828 
829     fprintf(stderr, "qemu: Supported NIC models: ");
830     for (i = 0 ; models[i]; i++)
831         fprintf(stderr, "%s%c", models[i], models[i+1] ? ',' : '\n');
832     return 1;
833 }
834 
835 void qemu_check_nic_model(NICInfo *nd, const char *model)
836 {
837     const char *models[2];
838 
839     models[0] = model;
840     models[1] = NULL;
841 
842     if (qemu_show_nic_models(nd->model, models))
843         exit(0);
844     if (qemu_find_nic_model(nd, models, model) < 0)
845         exit(1);
846 }
847 
848 int qemu_find_nic_model(NICInfo *nd, const char * const *models,
849                         const char *default_model)
850 {
851     int i;
852 
853     if (!nd->model)
854         nd->model = g_strdup(default_model);
855 
856     for (i = 0 ; models[i]; i++) {
857         if (strcmp(nd->model, models[i]) == 0)
858             return i;
859     }
860 
861     error_report("Unsupported NIC model: %s", nd->model);
862     return -1;
863 }
864 
865 static int net_init_nic(const NetClientOptions *opts, const char *name,
866                         NetClientState *peer, Error **errp)
867 {
868     int idx;
869     NICInfo *nd;
870     const NetLegacyNicOptions *nic;
871 
872     assert(opts->type == NET_CLIENT_OPTIONS_KIND_NIC);
873     nic = opts->u.nic.data;
874 
875     idx = nic_get_free_idx();
876     if (idx == -1 || nb_nics >= MAX_NICS) {
877         error_setg(errp, "too many NICs");
878         return -1;
879     }
880 
881     nd = &nd_table[idx];
882 
883     memset(nd, 0, sizeof(*nd));
884 
885     if (nic->has_netdev) {
886         nd->netdev = qemu_find_netdev(nic->netdev);
887         if (!nd->netdev) {
888             error_setg(errp, "netdev '%s' not found", nic->netdev);
889             return -1;
890         }
891     } else {
892         assert(peer);
893         nd->netdev = peer;
894     }
895     nd->name = g_strdup(name);
896     if (nic->has_model) {
897         nd->model = g_strdup(nic->model);
898     }
899     if (nic->has_addr) {
900         nd->devaddr = g_strdup(nic->addr);
901     }
902 
903     if (nic->has_macaddr &&
904         net_parse_macaddr(nd->macaddr.a, nic->macaddr) < 0) {
905         error_setg(errp, "invalid syntax for ethernet address");
906         return -1;
907     }
908     if (nic->has_macaddr &&
909         is_multicast_ether_addr(nd->macaddr.a)) {
910         error_setg(errp,
911                    "NIC cannot have multicast MAC address (odd 1st byte)");
912         return -1;
913     }
914     qemu_macaddr_default_if_unset(&nd->macaddr);
915 
916     if (nic->has_vectors) {
917         if (nic->vectors > 0x7ffffff) {
918             error_setg(errp, "invalid # of vectors: %"PRIu32, nic->vectors);
919             return -1;
920         }
921         nd->nvectors = nic->vectors;
922     } else {
923         nd->nvectors = DEV_NVECTORS_UNSPECIFIED;
924     }
925 
926     nd->used = 1;
927     nb_nics++;
928 
929     return idx;
930 }
931 
932 
933 static int (* const net_client_init_fun[NET_CLIENT_OPTIONS_KIND__MAX])(
934     const NetClientOptions *opts,
935     const char *name,
936     NetClientState *peer, Error **errp) = {
937         [NET_CLIENT_OPTIONS_KIND_NIC]       = net_init_nic,
938 #ifdef CONFIG_SLIRP
939         [NET_CLIENT_OPTIONS_KIND_USER]      = net_init_slirp,
940 #endif
941         [NET_CLIENT_OPTIONS_KIND_TAP]       = net_init_tap,
942         [NET_CLIENT_OPTIONS_KIND_SOCKET]    = net_init_socket,
943 #ifdef CONFIG_VDE
944         [NET_CLIENT_OPTIONS_KIND_VDE]       = net_init_vde,
945 #endif
946 #ifdef CONFIG_NETMAP
947         [NET_CLIENT_OPTIONS_KIND_NETMAP]    = net_init_netmap,
948 #endif
949         [NET_CLIENT_OPTIONS_KIND_DUMP]      = net_init_dump,
950 #ifdef CONFIG_NET_BRIDGE
951         [NET_CLIENT_OPTIONS_KIND_BRIDGE]    = net_init_bridge,
952 #endif
953         [NET_CLIENT_OPTIONS_KIND_HUBPORT]   = net_init_hubport,
954 #ifdef CONFIG_VHOST_NET_USED
955         [NET_CLIENT_OPTIONS_KIND_VHOST_USER] = net_init_vhost_user,
956 #endif
957 #ifdef CONFIG_L2TPV3
958         [NET_CLIENT_OPTIONS_KIND_L2TPV3]    = net_init_l2tpv3,
959 #endif
960 };
961 
962 
963 static int net_client_init1(const void *object, int is_netdev, Error **errp)
964 {
965     const NetClientOptions *opts;
966     const char *name;
967     NetClientState *peer = NULL;
968 
969     if (is_netdev) {
970         const Netdev *netdev = object;
971         opts = netdev->opts;
972         name = netdev->id;
973 
974         if (opts->type == NET_CLIENT_OPTIONS_KIND_DUMP ||
975             opts->type == NET_CLIENT_OPTIONS_KIND_NIC ||
976             !net_client_init_fun[opts->type]) {
977             error_setg(errp, QERR_INVALID_PARAMETER_VALUE, "type",
978                        "a netdev backend type");
979             return -1;
980         }
981     } else {
982         const NetLegacy *net = object;
983         opts = net->opts;
984         /* missing optional values have been initialized to "all bits zero" */
985         name = net->has_id ? net->id : net->name;
986 
987         if (opts->type == NET_CLIENT_OPTIONS_KIND_NONE) {
988             return 0; /* nothing to do */
989         }
990         if (opts->type == NET_CLIENT_OPTIONS_KIND_HUBPORT) {
991             error_setg(errp, QERR_INVALID_PARAMETER_VALUE, "type",
992                        "a net type");
993             return -1;
994         }
995 
996         if (!net_client_init_fun[opts->type]) {
997             error_setg(errp, QERR_INVALID_PARAMETER_VALUE, "type",
998                        "a net backend type (maybe it is not compiled "
999                        "into this binary)");
1000             return -1;
1001         }
1002 
1003         /* Do not add to a vlan if it's a nic with a netdev= parameter. */
1004         if (opts->type != NET_CLIENT_OPTIONS_KIND_NIC ||
1005             !opts->u.nic.data->has_netdev) {
1006             peer = net_hub_add_port(net->has_vlan ? net->vlan : 0, NULL);
1007         }
1008     }
1009 
1010     if (net_client_init_fun[opts->type](opts, name, peer, errp) < 0) {
1011         /* FIXME drop when all init functions store an Error */
1012         if (errp && !*errp) {
1013             error_setg(errp, QERR_DEVICE_INIT_FAILED,
1014                        NetClientOptionsKind_lookup[opts->type]);
1015         }
1016         return -1;
1017     }
1018     return 0;
1019 }
1020 
1021 
1022 int net_client_init(QemuOpts *opts, int is_netdev, Error **errp)
1023 {
1024     void *object = NULL;
1025     Error *err = NULL;
1026     int ret = -1;
1027     OptsVisitor *ov = opts_visitor_new(opts);
1028     Visitor *v = opts_get_visitor(ov);
1029 
1030     {
1031         /* Parse convenience option format ip6-net=fec0::0[/64] */
1032         const char *ip6_net = qemu_opt_get(opts, "ipv6-net");
1033 
1034         if (ip6_net) {
1035             char buf[strlen(ip6_net) + 1];
1036 
1037             if (get_str_sep(buf, sizeof(buf), &ip6_net, '/') < 0) {
1038                 /* Default 64bit prefix length.  */
1039                 qemu_opt_set(opts, "ipv6-prefix", ip6_net, &error_abort);
1040                 qemu_opt_set_number(opts, "ipv6-prefixlen", 64, &error_abort);
1041             } else {
1042                 /* User-specified prefix length.  */
1043                 unsigned long len;
1044                 int err;
1045 
1046                 qemu_opt_set(opts, "ipv6-prefix", buf, &error_abort);
1047                 err = qemu_strtoul(ip6_net, NULL, 10, &len);
1048 
1049                 if (err) {
1050                     error_setg(errp, QERR_INVALID_PARAMETER_VALUE,
1051                               "ipv6-prefix", "a number");
1052                 } else {
1053                     qemu_opt_set_number(opts, "ipv6-prefixlen", len,
1054                                         &error_abort);
1055                 }
1056             }
1057             qemu_opt_unset(opts, "ipv6-net");
1058         }
1059     }
1060 
1061     if (is_netdev) {
1062         visit_type_Netdev(v, NULL, (Netdev **)&object, &err);
1063     } else {
1064         visit_type_NetLegacy(v, NULL, (NetLegacy **)&object, &err);
1065     }
1066 
1067     if (!err) {
1068         ret = net_client_init1(object, is_netdev, &err);
1069     }
1070 
1071     if (is_netdev) {
1072         qapi_free_Netdev(object);
1073     } else {
1074         qapi_free_NetLegacy(object);
1075     }
1076 
1077     error_propagate(errp, err);
1078     opts_visitor_cleanup(ov);
1079     return ret;
1080 }
1081 
1082 
1083 static int net_host_check_device(const char *device)
1084 {
1085     int i;
1086     for (i = 0; host_net_devices[i]; i++) {
1087         if (!strncmp(host_net_devices[i], device,
1088                      strlen(host_net_devices[i]))) {
1089             return 1;
1090         }
1091     }
1092 
1093     return 0;
1094 }
1095 
1096 void hmp_host_net_add(Monitor *mon, const QDict *qdict)
1097 {
1098     const char *device = qdict_get_str(qdict, "device");
1099     const char *opts_str = qdict_get_try_str(qdict, "opts");
1100     Error *local_err = NULL;
1101     QemuOpts *opts;
1102 
1103     if (!net_host_check_device(device)) {
1104         monitor_printf(mon, "invalid host network device %s\n", device);
1105         return;
1106     }
1107 
1108     opts = qemu_opts_parse_noisily(qemu_find_opts("net"),
1109                                    opts_str ? opts_str : "", false);
1110     if (!opts) {
1111         return;
1112     }
1113 
1114     qemu_opt_set(opts, "type", device, &error_abort);
1115 
1116     net_client_init(opts, 0, &local_err);
1117     if (local_err) {
1118         error_report_err(local_err);
1119         monitor_printf(mon, "adding host network device %s failed\n", device);
1120     }
1121 }
1122 
1123 void hmp_host_net_remove(Monitor *mon, const QDict *qdict)
1124 {
1125     NetClientState *nc;
1126     int vlan_id = qdict_get_int(qdict, "vlan_id");
1127     const char *device = qdict_get_str(qdict, "device");
1128 
1129     nc = net_hub_find_client_by_name(vlan_id, device);
1130     if (!nc) {
1131         error_report("Host network device '%s' on hub '%d' not found",
1132                      device, vlan_id);
1133         return;
1134     }
1135     if (nc->info->type == NET_CLIENT_OPTIONS_KIND_NIC) {
1136         error_report("invalid host network device '%s'", device);
1137         return;
1138     }
1139 
1140     qemu_del_net_client(nc->peer);
1141     qemu_del_net_client(nc);
1142 }
1143 
1144 void netdev_add(QemuOpts *opts, Error **errp)
1145 {
1146     net_client_init(opts, 1, errp);
1147 }
1148 
1149 void qmp_netdev_add(QDict *qdict, QObject **ret, Error **errp)
1150 {
1151     Error *local_err = NULL;
1152     QemuOptsList *opts_list;
1153     QemuOpts *opts;
1154 
1155     opts_list = qemu_find_opts_err("netdev", &local_err);
1156     if (local_err) {
1157         goto out;
1158     }
1159 
1160     opts = qemu_opts_from_qdict(opts_list, qdict, &local_err);
1161     if (local_err) {
1162         goto out;
1163     }
1164 
1165     netdev_add(opts, &local_err);
1166     if (local_err) {
1167         qemu_opts_del(opts);
1168         goto out;
1169     }
1170 
1171 out:
1172     error_propagate(errp, local_err);
1173 }
1174 
1175 void qmp_netdev_del(const char *id, Error **errp)
1176 {
1177     NetClientState *nc;
1178     QemuOpts *opts;
1179 
1180     nc = qemu_find_netdev(id);
1181     if (!nc) {
1182         error_set(errp, ERROR_CLASS_DEVICE_NOT_FOUND,
1183                   "Device '%s' not found", id);
1184         return;
1185     }
1186 
1187     opts = qemu_opts_find(qemu_find_opts_err("netdev", NULL), id);
1188     if (!opts) {
1189         error_setg(errp, "Device '%s' is not a netdev", id);
1190         return;
1191     }
1192 
1193     qemu_del_net_client(nc);
1194     qemu_opts_del(opts);
1195 }
1196 
1197 static void netfilter_print_info(Monitor *mon, NetFilterState *nf)
1198 {
1199     char *str;
1200     ObjectProperty *prop;
1201     ObjectPropertyIterator iter;
1202     StringOutputVisitor *ov;
1203 
1204     /* generate info str */
1205     object_property_iter_init(&iter, OBJECT(nf));
1206     while ((prop = object_property_iter_next(&iter))) {
1207         if (!strcmp(prop->name, "type")) {
1208             continue;
1209         }
1210         ov = string_output_visitor_new(false);
1211         object_property_get(OBJECT(nf), string_output_get_visitor(ov),
1212                             prop->name, NULL);
1213         str = string_output_get_string(ov);
1214         string_output_visitor_cleanup(ov);
1215         monitor_printf(mon, ",%s=%s", prop->name, str);
1216         g_free(str);
1217     }
1218     monitor_printf(mon, "\n");
1219 }
1220 
1221 void print_net_client(Monitor *mon, NetClientState *nc)
1222 {
1223     NetFilterState *nf;
1224 
1225     monitor_printf(mon, "%s: index=%d,type=%s,%s\n", nc->name,
1226                    nc->queue_index,
1227                    NetClientOptionsKind_lookup[nc->info->type],
1228                    nc->info_str);
1229     if (!QTAILQ_EMPTY(&nc->filters)) {
1230         monitor_printf(mon, "filters:\n");
1231     }
1232     QTAILQ_FOREACH(nf, &nc->filters, next) {
1233         char *path = object_get_canonical_path_component(OBJECT(nf));
1234 
1235         monitor_printf(mon, "  - %s: type=%s", path,
1236                        object_get_typename(OBJECT(nf)));
1237         netfilter_print_info(mon, nf);
1238         g_free(path);
1239     }
1240 }
1241 
1242 RxFilterInfoList *qmp_query_rx_filter(bool has_name, const char *name,
1243                                       Error **errp)
1244 {
1245     NetClientState *nc;
1246     RxFilterInfoList *filter_list = NULL, *last_entry = NULL;
1247 
1248     QTAILQ_FOREACH(nc, &net_clients, next) {
1249         RxFilterInfoList *entry;
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_OPTIONS_KIND_NIC) {
1258             if (has_name) {
1259                 error_setg(errp, "net client(%s) isn't a NIC", name);
1260                 return NULL;
1261             }
1262             continue;
1263         }
1264 
1265         /* only query information on queue 0 since the info is per nic,
1266          * not per queue
1267          */
1268         if (nc->queue_index != 0)
1269             continue;
1270 
1271         if (nc->info->query_rx_filter) {
1272             info = nc->info->query_rx_filter(nc);
1273             entry = g_malloc0(sizeof(*entry));
1274             entry->value = info;
1275 
1276             if (!filter_list) {
1277                 filter_list = entry;
1278             } else {
1279                 last_entry->next = entry;
1280             }
1281             last_entry = entry;
1282         } else if (has_name) {
1283             error_setg(errp, "net client(%s) doesn't support"
1284                        " rx-filter querying", name);
1285             return NULL;
1286         }
1287 
1288         if (has_name) {
1289             break;
1290         }
1291     }
1292 
1293     if (filter_list == NULL && has_name) {
1294         error_setg(errp, "invalid net client name: %s", name);
1295     }
1296 
1297     return filter_list;
1298 }
1299 
1300 void hmp_info_network(Monitor *mon, const QDict *qdict)
1301 {
1302     NetClientState *nc, *peer;
1303     NetClientOptionsKind type;
1304 
1305     net_hub_info(mon);
1306 
1307     QTAILQ_FOREACH(nc, &net_clients, next) {
1308         peer = nc->peer;
1309         type = nc->info->type;
1310 
1311         /* Skip if already printed in hub info */
1312         if (net_hub_id_for_client(nc, NULL) == 0) {
1313             continue;
1314         }
1315 
1316         if (!peer || type == NET_CLIENT_OPTIONS_KIND_NIC) {
1317             print_net_client(mon, nc);
1318         } /* else it's a netdev connected to a NIC, printed with the NIC */
1319         if (peer && type == NET_CLIENT_OPTIONS_KIND_NIC) {
1320             monitor_printf(mon, " \\ ");
1321             print_net_client(mon, peer);
1322         }
1323     }
1324 }
1325 
1326 void qmp_set_link(const char *name, bool up, Error **errp)
1327 {
1328     NetClientState *ncs[MAX_QUEUE_NUM];
1329     NetClientState *nc;
1330     int queues, i;
1331 
1332     queues = qemu_find_net_clients_except(name, ncs,
1333                                           NET_CLIENT_OPTIONS_KIND__MAX,
1334                                           MAX_QUEUE_NUM);
1335 
1336     if (queues == 0) {
1337         error_set(errp, ERROR_CLASS_DEVICE_NOT_FOUND,
1338                   "Device '%s' not found", name);
1339         return;
1340     }
1341     nc = ncs[0];
1342 
1343     for (i = 0; i < queues; i++) {
1344         ncs[i]->link_down = !up;
1345     }
1346 
1347     if (nc->info->link_status_changed) {
1348         nc->info->link_status_changed(nc);
1349     }
1350 
1351     if (nc->peer) {
1352         /* Change peer link only if the peer is NIC and then notify peer.
1353          * If the peer is a HUBPORT or a backend, we do not change the
1354          * link status.
1355          *
1356          * This behavior is compatible with qemu vlans where there could be
1357          * multiple clients that can still communicate with each other in
1358          * disconnected mode. For now maintain this compatibility.
1359          */
1360         if (nc->peer->info->type == NET_CLIENT_OPTIONS_KIND_NIC) {
1361             for (i = 0; i < queues; i++) {
1362                 ncs[i]->peer->link_down = !up;
1363             }
1364         }
1365         if (nc->peer->info->link_status_changed) {
1366             nc->peer->info->link_status_changed(nc->peer);
1367         }
1368     }
1369 }
1370 
1371 static void net_vm_change_state_handler(void *opaque, int running,
1372                                         RunState state)
1373 {
1374     NetClientState *nc;
1375     NetClientState *tmp;
1376 
1377     QTAILQ_FOREACH_SAFE(nc, &net_clients, next, tmp) {
1378         if (running) {
1379             /* Flush queued packets and wake up backends. */
1380             if (nc->peer && qemu_can_send_packet(nc)) {
1381                 qemu_flush_queued_packets(nc->peer);
1382             }
1383         } else {
1384             /* Complete all queued packets, to guarantee we don't modify
1385              * state later when VM is not running.
1386              */
1387             qemu_flush_or_purge_queued_packets(nc, true);
1388         }
1389     }
1390 }
1391 
1392 void net_cleanup(void)
1393 {
1394     NetClientState *nc;
1395 
1396     /* We may del multiple entries during qemu_del_net_client(),
1397      * so QTAILQ_FOREACH_SAFE() is also not safe here.
1398      */
1399     while (!QTAILQ_EMPTY(&net_clients)) {
1400         nc = QTAILQ_FIRST(&net_clients);
1401         if (nc->info->type == NET_CLIENT_OPTIONS_KIND_NIC) {
1402             qemu_del_nic(qemu_get_nic(nc));
1403         } else {
1404             qemu_del_net_client(nc);
1405         }
1406     }
1407 
1408     qemu_del_vm_change_state_handler(net_change_state_entry);
1409 }
1410 
1411 void net_check_clients(void)
1412 {
1413     NetClientState *nc;
1414     int i;
1415 
1416     net_hub_check_clients();
1417 
1418     QTAILQ_FOREACH(nc, &net_clients, next) {
1419         if (!nc->peer) {
1420             fprintf(stderr, "Warning: %s %s has no peer\n",
1421                     nc->info->type == NET_CLIENT_OPTIONS_KIND_NIC ?
1422                     "nic" : "netdev", nc->name);
1423         }
1424     }
1425 
1426     /* Check that all NICs requested via -net nic actually got created.
1427      * NICs created via -device don't need to be checked here because
1428      * they are always instantiated.
1429      */
1430     for (i = 0; i < MAX_NICS; i++) {
1431         NICInfo *nd = &nd_table[i];
1432         if (nd->used && !nd->instantiated) {
1433             fprintf(stderr, "Warning: requested NIC (%s, model %s) "
1434                     "was not created (not supported by this machine?)\n",
1435                     nd->name ? nd->name : "anonymous",
1436                     nd->model ? nd->model : "unspecified");
1437         }
1438     }
1439 }
1440 
1441 static int net_init_client(void *dummy, QemuOpts *opts, Error **errp)
1442 {
1443     Error *local_err = NULL;
1444 
1445     net_client_init(opts, 0, &local_err);
1446     if (local_err) {
1447         error_report_err(local_err);
1448         return -1;
1449     }
1450 
1451     return 0;
1452 }
1453 
1454 static int net_init_netdev(void *dummy, QemuOpts *opts, Error **errp)
1455 {
1456     Error *local_err = NULL;
1457     int ret;
1458 
1459     ret = net_client_init(opts, 1, &local_err);
1460     if (local_err) {
1461         error_report_err(local_err);
1462         return -1;
1463     }
1464 
1465     return ret;
1466 }
1467 
1468 int net_init_clients(void)
1469 {
1470     QemuOptsList *net = qemu_find_opts("net");
1471 
1472     net_change_state_entry =
1473         qemu_add_vm_change_state_handler(net_vm_change_state_handler, NULL);
1474 
1475     QTAILQ_INIT(&net_clients);
1476 
1477     if (qemu_opts_foreach(qemu_find_opts("netdev"),
1478                           net_init_netdev, NULL, NULL)) {
1479         return -1;
1480     }
1481 
1482     if (qemu_opts_foreach(net, net_init_client, NULL, NULL)) {
1483         return -1;
1484     }
1485 
1486     return 0;
1487 }
1488 
1489 int net_client_parse(QemuOptsList *opts_list, const char *optarg)
1490 {
1491 #if defined(CONFIG_SLIRP)
1492     int ret;
1493     if (net_slirp_parse_legacy(opts_list, optarg, &ret)) {
1494         return ret;
1495     }
1496 #endif
1497 
1498     if (!qemu_opts_parse_noisily(opts_list, optarg, true)) {
1499         return -1;
1500     }
1501 
1502     return 0;
1503 }
1504 
1505 /* From FreeBSD */
1506 /* XXX: optimize */
1507 unsigned compute_mcast_idx(const uint8_t *ep)
1508 {
1509     uint32_t crc;
1510     int carry, i, j;
1511     uint8_t b;
1512 
1513     crc = 0xffffffff;
1514     for (i = 0; i < 6; i++) {
1515         b = *ep++;
1516         for (j = 0; j < 8; j++) {
1517             carry = ((crc & 0x80000000L) ? 1 : 0) ^ (b & 0x01);
1518             crc <<= 1;
1519             b >>= 1;
1520             if (carry) {
1521                 crc = ((crc ^ POLYNOMIAL) | carry);
1522             }
1523         }
1524     }
1525     return crc >> 26;
1526 }
1527 
1528 QemuOptsList qemu_netdev_opts = {
1529     .name = "netdev",
1530     .implied_opt_name = "type",
1531     .head = QTAILQ_HEAD_INITIALIZER(qemu_netdev_opts.head),
1532     .desc = {
1533         /*
1534          * no elements => accept any params
1535          * validation will happen later
1536          */
1537         { /* end of list */ }
1538     },
1539 };
1540 
1541 QemuOptsList qemu_net_opts = {
1542     .name = "net",
1543     .implied_opt_name = "type",
1544     .head = QTAILQ_HEAD_INITIALIZER(qemu_net_opts.head),
1545     .desc = {
1546         /*
1547          * no elements => accept any params
1548          * validation will happen later
1549          */
1550         { /* end of list */ }
1551     },
1552 };
1553 
1554 void net_socket_rs_init(SocketReadState *rs,
1555                         SocketReadStateFinalize *finalize)
1556 {
1557     rs->state = 0;
1558     rs->index = 0;
1559     rs->packet_len = 0;
1560     memset(rs->buf, 0, sizeof(rs->buf));
1561     rs->finalize = finalize;
1562 }
1563 
1564 /*
1565  * Returns
1566  * 0: SocketReadState is not ready
1567  * 1: SocketReadState is ready
1568  * otherwise error occurs
1569  */
1570 int net_fill_rstate(SocketReadState *rs, const uint8_t *buf, int size)
1571 {
1572     unsigned int l;
1573 
1574     while (size > 0) {
1575         /* reassemble a packet from the network */
1576         switch (rs->state) { /* 0 = getting length, 1 = getting data */
1577         case 0:
1578             l = 4 - rs->index;
1579             if (l > size) {
1580                 l = size;
1581             }
1582             memcpy(rs->buf + rs->index, buf, l);
1583             buf += l;
1584             size -= l;
1585             rs->index += l;
1586             if (rs->index == 4) {
1587                 /* got length */
1588                 rs->packet_len = ntohl(*(uint32_t *)rs->buf);
1589                 rs->index = 0;
1590                 rs->state = 1;
1591             }
1592             break;
1593         case 1:
1594             l = rs->packet_len - rs->index;
1595             if (l > size) {
1596                 l = size;
1597             }
1598             if (rs->index + l <= sizeof(rs->buf)) {
1599                 memcpy(rs->buf + rs->index, buf, l);
1600             } else {
1601                 fprintf(stderr, "serious error: oversized packet received,"
1602                     "connection terminated.\n");
1603                 rs->index = rs->state = 0;
1604                 return -1;
1605             }
1606 
1607             rs->index += l;
1608             buf += l;
1609             size -= l;
1610             if (rs->index >= rs->packet_len) {
1611                 rs->index = 0;
1612                 rs->state = 0;
1613                 if (rs->finalize) {
1614                     rs->finalize(rs);
1615                 }
1616                 return 1;
1617             }
1618             break;
1619         }
1620     }
1621     return 0;
1622 }
1623