xref: /qemu/net/colo-compare.c (revision 99dbfd1d)
1 /*
2  * COarse-grain LOck-stepping Virtual Machines for Non-stop Service (COLO)
3  * (a.k.a. Fault Tolerance or Continuous Replication)
4  *
5  * Copyright (c) 2016 HUAWEI TECHNOLOGIES CO., LTD.
6  * Copyright (c) 2016 FUJITSU LIMITED
7  * Copyright (c) 2016 Intel Corporation
8  *
9  * Author: Zhang Chen <zhangchen.fnst@cn.fujitsu.com>
10  *
11  * This work is licensed under the terms of the GNU GPL, version 2 or
12  * later.  See the COPYING file in the top-level directory.
13  */
14 
15 #include "qemu/osdep.h"
16 #include "qemu/error-report.h"
17 #include "trace.h"
18 #include "qemu-common.h"
19 #include "qapi/qmp/qerror.h"
20 #include "qapi/error.h"
21 #include "net/net.h"
22 #include "net/eth.h"
23 #include "qom/object_interfaces.h"
24 #include "qemu/iov.h"
25 #include "qom/object.h"
26 #include "qemu/typedefs.h"
27 #include "net/queue.h"
28 #include "sysemu/char.h"
29 #include "qemu/sockets.h"
30 #include "qapi-visit.h"
31 #include "net/colo.h"
32 
33 #define TYPE_COLO_COMPARE "colo-compare"
34 #define COLO_COMPARE(obj) \
35     OBJECT_CHECK(CompareState, (obj), TYPE_COLO_COMPARE)
36 
37 #define COMPARE_READ_LEN_MAX NET_BUFSIZE
38 #define MAX_QUEUE_SIZE 1024
39 
40 /* TODO: Should be configurable */
41 #define REGULAR_PACKET_CHECK_MS 3000
42 
43 /*
44   + CompareState ++
45   |               |
46   +---------------+   +---------------+         +---------------+
47   |conn list      +--->conn           +--------->conn           |
48   +---------------+   +---------------+         +---------------+
49   |               |     |           |             |          |
50   +---------------+ +---v----+  +---v----+    +---v----+ +---v----+
51                     |primary |  |secondary    |primary | |secondary
52                     |packet  |  |packet  +    |packet  | |packet  +
53                     +--------+  +--------+    +--------+ +--------+
54                         |           |             |          |
55                     +---v----+  +---v----+    +---v----+ +---v----+
56                     |primary |  |secondary    |primary | |secondary
57                     |packet  |  |packet  +    |packet  | |packet  +
58                     +--------+  +--------+    +--------+ +--------+
59                         |           |             |          |
60                     +---v----+  +---v----+    +---v----+ +---v----+
61                     |primary |  |secondary    |primary | |secondary
62                     |packet  |  |packet  +    |packet  | |packet  +
63                     +--------+  +--------+    +--------+ +--------+
64 */
65 typedef struct CompareState {
66     Object parent;
67 
68     char *pri_indev;
69     char *sec_indev;
70     char *outdev;
71     CharBackend chr_pri_in;
72     CharBackend chr_sec_in;
73     CharBackend chr_out;
74     SocketReadState pri_rs;
75     SocketReadState sec_rs;
76 
77     /* connection list: the connections belonged to this NIC could be found
78      * in this list.
79      * element type: Connection
80      */
81     GQueue conn_list;
82     /* hashtable to save connection */
83     GHashTable *connection_track_table;
84     /* compare thread, a thread for each NIC */
85     QemuThread thread;
86 
87     GMainContext *worker_context;
88     GMainLoop *compare_loop;
89 } CompareState;
90 
91 typedef struct CompareClass {
92     ObjectClass parent_class;
93 } CompareClass;
94 
95 enum {
96     PRIMARY_IN = 0,
97     SECONDARY_IN,
98 };
99 
100 static int compare_chr_send(CharBackend *out,
101                             const uint8_t *buf,
102                             uint32_t size);
103 
104 static gint seq_sorter(Packet *a, Packet *b, gpointer data)
105 {
106     struct tcphdr *atcp, *btcp;
107 
108     atcp = (struct tcphdr *)(a->transport_header);
109     btcp = (struct tcphdr *)(b->transport_header);
110     return ntohl(atcp->th_seq) - ntohl(btcp->th_seq);
111 }
112 
113 /*
114  * Return 0 on success, if return -1 means the pkt
115  * is unsupported(arp and ipv6) and will be sent later
116  */
117 static int packet_enqueue(CompareState *s, int mode)
118 {
119     ConnectionKey key;
120     Packet *pkt = NULL;
121     Connection *conn;
122 
123     if (mode == PRIMARY_IN) {
124         pkt = packet_new(s->pri_rs.buf, s->pri_rs.packet_len);
125     } else {
126         pkt = packet_new(s->sec_rs.buf, s->sec_rs.packet_len);
127     }
128 
129     if (parse_packet_early(pkt)) {
130         packet_destroy(pkt, NULL);
131         pkt = NULL;
132         return -1;
133     }
134     fill_connection_key(pkt, &key);
135 
136     conn = connection_get(s->connection_track_table,
137                           &key,
138                           &s->conn_list);
139 
140     if (!conn->processing) {
141         g_queue_push_tail(&s->conn_list, conn);
142         conn->processing = true;
143     }
144 
145     if (mode == PRIMARY_IN) {
146         if (g_queue_get_length(&conn->primary_list) <=
147                                MAX_QUEUE_SIZE) {
148             g_queue_push_tail(&conn->primary_list, pkt);
149             if (conn->ip_proto == IPPROTO_TCP) {
150                 g_queue_sort(&conn->primary_list,
151                              (GCompareDataFunc)seq_sorter,
152                              NULL);
153             }
154         } else {
155             error_report("colo compare primary queue size too big,"
156                          "drop packet");
157         }
158     } else {
159         if (g_queue_get_length(&conn->secondary_list) <=
160                                MAX_QUEUE_SIZE) {
161             g_queue_push_tail(&conn->secondary_list, pkt);
162             if (conn->ip_proto == IPPROTO_TCP) {
163                 g_queue_sort(&conn->secondary_list,
164                              (GCompareDataFunc)seq_sorter,
165                              NULL);
166             }
167         } else {
168             error_report("colo compare secondary queue size too big,"
169                          "drop packet");
170         }
171     }
172 
173     return 0;
174 }
175 
176 /*
177  * The IP packets sent by primary and secondary
178  * will be compared in here
179  * TODO support ip fragment, Out-Of-Order
180  * return:    0  means packet same
181  *            > 0 || < 0 means packet different
182  */
183 static int colo_packet_compare_common(Packet *ppkt, Packet *spkt, int offset)
184 {
185     trace_colo_compare_ip_info(ppkt->size, inet_ntoa(ppkt->ip->ip_src),
186                                inet_ntoa(ppkt->ip->ip_dst), spkt->size,
187                                inet_ntoa(spkt->ip->ip_src),
188                                inet_ntoa(spkt->ip->ip_dst));
189 
190     if (ppkt->size == spkt->size) {
191         return memcmp(ppkt->data + offset, spkt->data + offset,
192                       spkt->size - offset);
193     } else {
194         trace_colo_compare_main("Net packet size are not the same");
195         return -1;
196     }
197 }
198 
199 /*
200  * Called from the compare thread on the primary
201  * for compare tcp packet
202  * compare_tcp copied from Dr. David Alan Gilbert's branch
203  */
204 static int colo_packet_compare_tcp(Packet *spkt, Packet *ppkt)
205 {
206     struct tcphdr *ptcp, *stcp;
207     int res;
208 
209     trace_colo_compare_main("compare tcp");
210 
211     ptcp = (struct tcphdr *)ppkt->transport_header;
212     stcp = (struct tcphdr *)spkt->transport_header;
213 
214     /*
215      * The 'identification' field in the IP header is *very* random
216      * it almost never matches.  Fudge this by ignoring differences in
217      * unfragmented packets; they'll normally sort themselves out if different
218      * anyway, and it should recover at the TCP level.
219      * An alternative would be to get both the primary and secondary to rewrite
220      * somehow; but that would need some sync traffic to sync the state
221      */
222     if (ntohs(ppkt->ip->ip_off) & IP_DF) {
223         spkt->ip->ip_id = ppkt->ip->ip_id;
224         /* and the sum will be different if the IDs were different */
225         spkt->ip->ip_sum = ppkt->ip->ip_sum;
226     }
227 
228     if (ptcp->th_sum == stcp->th_sum) {
229         res = colo_packet_compare_common(ppkt, spkt, ETH_HLEN);
230     } else {
231         res = -1;
232     }
233 
234     if (res != 0 && trace_event_get_state(TRACE_COLO_COMPARE_MISCOMPARE)) {
235         trace_colo_compare_pkt_info_src(inet_ntoa(ppkt->ip->ip_src),
236                                         ntohl(stcp->th_seq),
237                                         ntohl(stcp->th_ack),
238                                         res, stcp->th_flags,
239                                         spkt->size);
240 
241         trace_colo_compare_pkt_info_dst(inet_ntoa(ppkt->ip->ip_dst),
242                                         ntohl(ptcp->th_seq),
243                                         ntohl(ptcp->th_ack),
244                                         res, ptcp->th_flags,
245                                         ppkt->size);
246 
247         qemu_hexdump((char *)ppkt->data, stderr,
248                      "colo-compare ppkt", ppkt->size);
249         qemu_hexdump((char *)spkt->data, stderr,
250                      "colo-compare spkt", spkt->size);
251     }
252 
253     return res;
254 }
255 
256 /*
257  * Called from the compare thread on the primary
258  * for compare udp packet
259  */
260 static int colo_packet_compare_udp(Packet *spkt, Packet *ppkt)
261 {
262     int ret;
263     int network_header_length = ppkt->ip->ip_hl * 4;
264 
265     trace_colo_compare_main("compare udp");
266 
267     /*
268      * Because of ppkt and spkt are both in the same connection,
269      * The ppkt's src ip, dst ip, src port, dst port, ip_proto all are
270      * same with spkt. In addition, IP header's Identification is a random
271      * field, we can handle it in IP fragmentation function later.
272      * COLO just concern the response net packet payload from primary guest
273      * and secondary guest are same or not, So we ignored all IP header include
274      * other field like TOS,TTL,IP Checksum. we only need to compare
275      * the ip payload here.
276      */
277     ret = colo_packet_compare_common(ppkt, spkt,
278                                      network_header_length + ETH_HLEN);
279 
280     if (ret) {
281         trace_colo_compare_udp_miscompare("primary pkt size", ppkt->size);
282         trace_colo_compare_udp_miscompare("Secondary pkt size", spkt->size);
283         if (trace_event_get_state(TRACE_COLO_COMPARE_MISCOMPARE)) {
284             qemu_hexdump((char *)ppkt->data, stderr, "colo-compare pri pkt",
285                          ppkt->size);
286             qemu_hexdump((char *)spkt->data, stderr, "colo-compare sec pkt",
287                          spkt->size);
288         }
289     }
290 
291     return ret;
292 }
293 
294 /*
295  * Called from the compare thread on the primary
296  * for compare icmp packet
297  */
298 static int colo_packet_compare_icmp(Packet *spkt, Packet *ppkt)
299 {
300     int network_header_length = ppkt->ip->ip_hl * 4;
301 
302     trace_colo_compare_main("compare icmp");
303 
304     /*
305      * Because of ppkt and spkt are both in the same connection,
306      * The ppkt's src ip, dst ip, src port, dst port, ip_proto all are
307      * same with spkt. In addition, IP header's Identification is a random
308      * field, we can handle it in IP fragmentation function later.
309      * COLO just concern the response net packet payload from primary guest
310      * and secondary guest are same or not, So we ignored all IP header include
311      * other field like TOS,TTL,IP Checksum. we only need to compare
312      * the ip payload here.
313      */
314     if (colo_packet_compare_common(ppkt, spkt,
315                                    network_header_length + ETH_HLEN)) {
316         trace_colo_compare_icmp_miscompare("primary pkt size",
317                                            ppkt->size);
318         trace_colo_compare_icmp_miscompare("Secondary pkt size",
319                                            spkt->size);
320         if (trace_event_get_state(TRACE_COLO_COMPARE_MISCOMPARE)) {
321             qemu_hexdump((char *)ppkt->data, stderr, "colo-compare pri pkt",
322                          ppkt->size);
323             qemu_hexdump((char *)spkt->data, stderr, "colo-compare sec pkt",
324                          spkt->size);
325         }
326         return -1;
327     } else {
328         return 0;
329     }
330 }
331 
332 /*
333  * Called from the compare thread on the primary
334  * for compare other packet
335  */
336 static int colo_packet_compare_other(Packet *spkt, Packet *ppkt)
337 {
338     trace_colo_compare_main("compare other");
339     trace_colo_compare_ip_info(ppkt->size, inet_ntoa(ppkt->ip->ip_src),
340                                inet_ntoa(ppkt->ip->ip_dst), spkt->size,
341                                inet_ntoa(spkt->ip->ip_src),
342                                inet_ntoa(spkt->ip->ip_dst));
343     return colo_packet_compare_common(ppkt, spkt, 0);
344 }
345 
346 static int colo_old_packet_check_one(Packet *pkt, int64_t *check_time)
347 {
348     int64_t now = qemu_clock_get_ms(QEMU_CLOCK_HOST);
349 
350     if ((now - pkt->creation_ms) > (*check_time)) {
351         trace_colo_old_packet_check_found(pkt->creation_ms);
352         return 0;
353     } else {
354         return 1;
355     }
356 }
357 
358 static void colo_old_packet_check_one_conn(void *opaque,
359                                            void *user_data)
360 {
361     Connection *conn = opaque;
362     GList *result = NULL;
363     int64_t check_time = REGULAR_PACKET_CHECK_MS;
364 
365     result = g_queue_find_custom(&conn->primary_list,
366                                  &check_time,
367                                  (GCompareFunc)colo_old_packet_check_one);
368 
369     if (result) {
370         /* do checkpoint will flush old packet */
371         /* TODO: colo_notify_checkpoint();*/
372     }
373 }
374 
375 /*
376  * Look for old packets that the secondary hasn't matched,
377  * if we have some then we have to checkpoint to wake
378  * the secondary up.
379  */
380 static void colo_old_packet_check(void *opaque)
381 {
382     CompareState *s = opaque;
383 
384     g_queue_foreach(&s->conn_list, colo_old_packet_check_one_conn, NULL);
385 }
386 
387 /*
388  * Called from the compare thread on the primary
389  * for compare connection
390  */
391 static void colo_compare_connection(void *opaque, void *user_data)
392 {
393     CompareState *s = user_data;
394     Connection *conn = opaque;
395     Packet *pkt = NULL;
396     GList *result = NULL;
397     int ret;
398 
399     while (!g_queue_is_empty(&conn->primary_list) &&
400            !g_queue_is_empty(&conn->secondary_list)) {
401         pkt = g_queue_pop_tail(&conn->primary_list);
402         switch (conn->ip_proto) {
403         case IPPROTO_TCP:
404             result = g_queue_find_custom(&conn->secondary_list,
405                      pkt, (GCompareFunc)colo_packet_compare_tcp);
406             break;
407         case IPPROTO_UDP:
408             result = g_queue_find_custom(&conn->secondary_list,
409                      pkt, (GCompareFunc)colo_packet_compare_udp);
410             break;
411         case IPPROTO_ICMP:
412             result = g_queue_find_custom(&conn->secondary_list,
413                      pkt, (GCompareFunc)colo_packet_compare_icmp);
414             break;
415         default:
416             result = g_queue_find_custom(&conn->secondary_list,
417                      pkt, (GCompareFunc)colo_packet_compare_other);
418             break;
419         }
420 
421         if (result) {
422             ret = compare_chr_send(&s->chr_out, pkt->data, pkt->size);
423             if (ret < 0) {
424                 error_report("colo_send_primary_packet failed");
425             }
426             trace_colo_compare_main("packet same and release packet");
427             g_queue_remove(&conn->secondary_list, result->data);
428             packet_destroy(pkt, NULL);
429         } else {
430             /*
431              * If one packet arrive late, the secondary_list or
432              * primary_list will be empty, so we can't compare it
433              * until next comparison.
434              */
435             trace_colo_compare_main("packet different");
436             g_queue_push_tail(&conn->primary_list, pkt);
437             /* TODO: colo_notify_checkpoint();*/
438             break;
439         }
440     }
441 }
442 
443 static int compare_chr_send(CharBackend *out,
444                             const uint8_t *buf,
445                             uint32_t size)
446 {
447     int ret = 0;
448     uint32_t len = htonl(size);
449 
450     if (!size) {
451         return 0;
452     }
453 
454     ret = qemu_chr_fe_write_all(out, (uint8_t *)&len, sizeof(len));
455     if (ret != sizeof(len)) {
456         goto err;
457     }
458 
459     ret = qemu_chr_fe_write_all(out, (uint8_t *)buf, size);
460     if (ret != size) {
461         goto err;
462     }
463 
464     return 0;
465 
466 err:
467     return ret < 0 ? ret : -EIO;
468 }
469 
470 static int compare_chr_can_read(void *opaque)
471 {
472     return COMPARE_READ_LEN_MAX;
473 }
474 
475 /*
476  * Called from the main thread on the primary for packets
477  * arriving over the socket from the primary.
478  */
479 static void compare_pri_chr_in(void *opaque, const uint8_t *buf, int size)
480 {
481     CompareState *s = COLO_COMPARE(opaque);
482     int ret;
483 
484     ret = net_fill_rstate(&s->pri_rs, buf, size);
485     if (ret == -1) {
486         qemu_chr_fe_set_handlers(&s->chr_pri_in, NULL, NULL, NULL,
487                                  NULL, NULL, true);
488         error_report("colo-compare primary_in error");
489     }
490 }
491 
492 /*
493  * Called from the main thread on the primary for packets
494  * arriving over the socket from the secondary.
495  */
496 static void compare_sec_chr_in(void *opaque, const uint8_t *buf, int size)
497 {
498     CompareState *s = COLO_COMPARE(opaque);
499     int ret;
500 
501     ret = net_fill_rstate(&s->sec_rs, buf, size);
502     if (ret == -1) {
503         qemu_chr_fe_set_handlers(&s->chr_sec_in, NULL, NULL, NULL,
504                                  NULL, NULL, true);
505         error_report("colo-compare secondary_in error");
506     }
507 }
508 
509 /*
510  * Check old packet regularly so it can watch for any packets
511  * that the secondary hasn't produced equivalents of.
512  */
513 static gboolean check_old_packet_regular(void *opaque)
514 {
515     CompareState *s = opaque;
516 
517     /* if have old packet we will notify checkpoint */
518     colo_old_packet_check(s);
519 
520     return TRUE;
521 }
522 
523 static void *colo_compare_thread(void *opaque)
524 {
525     CompareState *s = opaque;
526     GSource *timeout_source;
527 
528     s->worker_context = g_main_context_new();
529 
530     qemu_chr_fe_set_handlers(&s->chr_pri_in, compare_chr_can_read,
531                           compare_pri_chr_in, NULL, s, s->worker_context, true);
532     qemu_chr_fe_set_handlers(&s->chr_sec_in, compare_chr_can_read,
533                           compare_sec_chr_in, NULL, s, s->worker_context, true);
534 
535     s->compare_loop = g_main_loop_new(s->worker_context, FALSE);
536 
537     /* To kick any packets that the secondary doesn't match */
538     timeout_source = g_timeout_source_new(REGULAR_PACKET_CHECK_MS);
539     g_source_set_callback(timeout_source,
540                           (GSourceFunc)check_old_packet_regular, s, NULL);
541     g_source_attach(timeout_source, s->worker_context);
542 
543     g_main_loop_run(s->compare_loop);
544 
545     g_source_unref(timeout_source);
546     g_main_loop_unref(s->compare_loop);
547     g_main_context_unref(s->worker_context);
548     return NULL;
549 }
550 
551 static char *compare_get_pri_indev(Object *obj, Error **errp)
552 {
553     CompareState *s = COLO_COMPARE(obj);
554 
555     return g_strdup(s->pri_indev);
556 }
557 
558 static void compare_set_pri_indev(Object *obj, const char *value, Error **errp)
559 {
560     CompareState *s = COLO_COMPARE(obj);
561 
562     g_free(s->pri_indev);
563     s->pri_indev = g_strdup(value);
564 }
565 
566 static char *compare_get_sec_indev(Object *obj, Error **errp)
567 {
568     CompareState *s = COLO_COMPARE(obj);
569 
570     return g_strdup(s->sec_indev);
571 }
572 
573 static void compare_set_sec_indev(Object *obj, const char *value, Error **errp)
574 {
575     CompareState *s = COLO_COMPARE(obj);
576 
577     g_free(s->sec_indev);
578     s->sec_indev = g_strdup(value);
579 }
580 
581 static char *compare_get_outdev(Object *obj, Error **errp)
582 {
583     CompareState *s = COLO_COMPARE(obj);
584 
585     return g_strdup(s->outdev);
586 }
587 
588 static void compare_set_outdev(Object *obj, const char *value, Error **errp)
589 {
590     CompareState *s = COLO_COMPARE(obj);
591 
592     g_free(s->outdev);
593     s->outdev = g_strdup(value);
594 }
595 
596 static void compare_pri_rs_finalize(SocketReadState *pri_rs)
597 {
598     CompareState *s = container_of(pri_rs, CompareState, pri_rs);
599 
600     if (packet_enqueue(s, PRIMARY_IN)) {
601         trace_colo_compare_main("primary: unsupported packet in");
602         compare_chr_send(&s->chr_out, pri_rs->buf, pri_rs->packet_len);
603     } else {
604         /* compare connection */
605         g_queue_foreach(&s->conn_list, colo_compare_connection, s);
606     }
607 }
608 
609 static void compare_sec_rs_finalize(SocketReadState *sec_rs)
610 {
611     CompareState *s = container_of(sec_rs, CompareState, sec_rs);
612 
613     if (packet_enqueue(s, SECONDARY_IN)) {
614         trace_colo_compare_main("secondary: unsupported packet in");
615     } else {
616         /* compare connection */
617         g_queue_foreach(&s->conn_list, colo_compare_connection, s);
618     }
619 }
620 
621 
622 /*
623  * Return 0 is success.
624  * Return 1 is failed.
625  */
626 static int find_and_check_chardev(Chardev **chr,
627                                   char *chr_name,
628                                   Error **errp)
629 {
630     *chr = qemu_chr_find(chr_name);
631     if (*chr == NULL) {
632         error_setg(errp, "Device '%s' not found",
633                    chr_name);
634         return 1;
635     }
636 
637     if (!qemu_chr_has_feature(*chr, QEMU_CHAR_FEATURE_RECONNECTABLE)) {
638         error_setg(errp, "chardev \"%s\" is not reconnectable",
639                    chr_name);
640         return 1;
641     }
642 
643     return 0;
644 }
645 
646 /*
647  * Called from the main thread on the primary
648  * to setup colo-compare.
649  */
650 static void colo_compare_complete(UserCreatable *uc, Error **errp)
651 {
652     CompareState *s = COLO_COMPARE(uc);
653     Chardev *chr;
654     char thread_name[64];
655     static int compare_id;
656 
657     if (!s->pri_indev || !s->sec_indev || !s->outdev) {
658         error_setg(errp, "colo compare needs 'primary_in' ,"
659                    "'secondary_in','outdev' property set");
660         return;
661     } else if (!strcmp(s->pri_indev, s->outdev) ||
662                !strcmp(s->sec_indev, s->outdev) ||
663                !strcmp(s->pri_indev, s->sec_indev)) {
664         error_setg(errp, "'indev' and 'outdev' could not be same "
665                    "for compare module");
666         return;
667     }
668 
669     if (find_and_check_chardev(&chr, s->pri_indev, errp) ||
670         !qemu_chr_fe_init(&s->chr_pri_in, chr, errp)) {
671         return;
672     }
673 
674     if (find_and_check_chardev(&chr, s->sec_indev, errp) ||
675         !qemu_chr_fe_init(&s->chr_sec_in, chr, errp)) {
676         return;
677     }
678 
679     if (find_and_check_chardev(&chr, s->outdev, errp) ||
680         !qemu_chr_fe_init(&s->chr_out, chr, errp)) {
681         return;
682     }
683 
684     net_socket_rs_init(&s->pri_rs, compare_pri_rs_finalize);
685     net_socket_rs_init(&s->sec_rs, compare_sec_rs_finalize);
686 
687     g_queue_init(&s->conn_list);
688 
689     s->connection_track_table = g_hash_table_new_full(connection_key_hash,
690                                                       connection_key_equal,
691                                                       g_free,
692                                                       connection_destroy);
693 
694     sprintf(thread_name, "colo-compare %d", compare_id);
695     qemu_thread_create(&s->thread, thread_name,
696                        colo_compare_thread, s,
697                        QEMU_THREAD_JOINABLE);
698     compare_id++;
699 
700     return;
701 }
702 
703 static void colo_flush_packets(void *opaque, void *user_data)
704 {
705     CompareState *s = user_data;
706     Connection *conn = opaque;
707     Packet *pkt = NULL;
708 
709     while (!g_queue_is_empty(&conn->primary_list)) {
710         pkt = g_queue_pop_head(&conn->primary_list);
711         compare_chr_send(&s->chr_out, pkt->data, pkt->size);
712         packet_destroy(pkt, NULL);
713     }
714     while (!g_queue_is_empty(&conn->secondary_list)) {
715         pkt = g_queue_pop_head(&conn->secondary_list);
716         packet_destroy(pkt, NULL);
717     }
718 }
719 
720 static void colo_compare_class_init(ObjectClass *oc, void *data)
721 {
722     UserCreatableClass *ucc = USER_CREATABLE_CLASS(oc);
723 
724     ucc->complete = colo_compare_complete;
725 }
726 
727 static void colo_compare_init(Object *obj)
728 {
729     object_property_add_str(obj, "primary_in",
730                             compare_get_pri_indev, compare_set_pri_indev,
731                             NULL);
732     object_property_add_str(obj, "secondary_in",
733                             compare_get_sec_indev, compare_set_sec_indev,
734                             NULL);
735     object_property_add_str(obj, "outdev",
736                             compare_get_outdev, compare_set_outdev,
737                             NULL);
738 }
739 
740 static void colo_compare_finalize(Object *obj)
741 {
742     CompareState *s = COLO_COMPARE(obj);
743 
744     qemu_chr_fe_set_handlers(&s->chr_pri_in, NULL, NULL, NULL, NULL,
745                              s->worker_context, true);
746     qemu_chr_fe_set_handlers(&s->chr_sec_in, NULL, NULL, NULL, NULL,
747                              s->worker_context, true);
748     qemu_chr_fe_deinit(&s->chr_out);
749 
750     g_main_loop_quit(s->compare_loop);
751     qemu_thread_join(&s->thread);
752 
753     /* Release all unhandled packets after compare thead exited */
754     g_queue_foreach(&s->conn_list, colo_flush_packets, s);
755 
756     g_queue_clear(&s->conn_list);
757 
758     g_hash_table_destroy(s->connection_track_table);
759     g_free(s->pri_indev);
760     g_free(s->sec_indev);
761     g_free(s->outdev);
762 }
763 
764 static const TypeInfo colo_compare_info = {
765     .name = TYPE_COLO_COMPARE,
766     .parent = TYPE_OBJECT,
767     .instance_size = sizeof(CompareState),
768     .instance_init = colo_compare_init,
769     .instance_finalize = colo_compare_finalize,
770     .class_size = sizeof(CompareClass),
771     .class_init = colo_compare_class_init,
772     .interfaces = (InterfaceInfo[]) {
773         { TYPE_USER_CREATABLE },
774         { }
775     }
776 };
777 
778 static void register_types(void)
779 {
780     type_register_static(&colo_compare_info);
781 }
782 
783 type_init(register_types);
784