xref: /openbmc/qemu/net/colo-compare.c (revision 9cbb6362)
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 "net/queue.h"
27 #include "chardev/char-fe.h"
28 #include "qemu/sockets.h"
29 #include "qapi-visit.h"
30 #include "net/colo.h"
31 #include "sysemu/iothread.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     bool vnet_hdr;
77 
78     /*
79      * Record the connection that through the NIC
80      * Element type: Connection
81      */
82     GQueue conn_list;
83     /* Record the connection without repetition */
84     GHashTable *connection_track_table;
85 
86     IOThread *iothread;
87     GMainContext *worker_context;
88     QEMUTimer *packet_check_timer;
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(CompareState *s,
101                             const uint8_t *buf,
102                             uint32_t size,
103                             uint32_t vnet_hdr_len);
104 
105 static gint seq_sorter(Packet *a, Packet *b, gpointer data)
106 {
107     struct tcphdr *atcp, *btcp;
108 
109     atcp = (struct tcphdr *)(a->transport_header);
110     btcp = (struct tcphdr *)(b->transport_header);
111     return ntohl(atcp->th_seq) - ntohl(btcp->th_seq);
112 }
113 
114 /*
115  * Return 1 on success, if return 0 means the
116  * packet will be dropped
117  */
118 static int colo_insert_packet(GQueue *queue, Packet *pkt)
119 {
120     if (g_queue_get_length(queue) <= MAX_QUEUE_SIZE) {
121         if (pkt->ip->ip_p == IPPROTO_TCP) {
122             g_queue_insert_sorted(queue,
123                                   pkt,
124                                   (GCompareDataFunc)seq_sorter,
125                                   NULL);
126         } else {
127             g_queue_push_tail(queue, pkt);
128         }
129         return 1;
130     }
131     return 0;
132 }
133 
134 /*
135  * Return 0 on success, if return -1 means the pkt
136  * is unsupported(arp and ipv6) and will be sent later
137  */
138 static int packet_enqueue(CompareState *s, int mode, Connection **con)
139 {
140     ConnectionKey key;
141     Packet *pkt = NULL;
142     Connection *conn;
143 
144     if (mode == PRIMARY_IN) {
145         pkt = packet_new(s->pri_rs.buf,
146                          s->pri_rs.packet_len,
147                          s->pri_rs.vnet_hdr_len);
148     } else {
149         pkt = packet_new(s->sec_rs.buf,
150                          s->sec_rs.packet_len,
151                          s->sec_rs.vnet_hdr_len);
152     }
153 
154     if (parse_packet_early(pkt)) {
155         packet_destroy(pkt, NULL);
156         pkt = NULL;
157         return -1;
158     }
159     fill_connection_key(pkt, &key);
160 
161     conn = connection_get(s->connection_track_table,
162                           &key,
163                           &s->conn_list);
164 
165     if (!conn->processing) {
166         g_queue_push_tail(&s->conn_list, conn);
167         conn->processing = true;
168     }
169 
170     if (mode == PRIMARY_IN) {
171         if (!colo_insert_packet(&conn->primary_list, pkt)) {
172             error_report("colo compare primary queue size too big,"
173                          "drop packet");
174         }
175     } else {
176         if (!colo_insert_packet(&conn->secondary_list, pkt)) {
177             error_report("colo compare secondary queue size too big,"
178                          "drop packet");
179         }
180     }
181     *con = conn;
182 
183     return 0;
184 }
185 
186 /*
187  * The IP packets sent by primary and secondary
188  * will be compared in here
189  * TODO support ip fragment, Out-Of-Order
190  * return:    0  means packet same
191  *            > 0 || < 0 means packet different
192  */
193 static int colo_packet_compare_common(Packet *ppkt,
194                                       Packet *spkt,
195                                       int poffset,
196                                       int soffset)
197 {
198     if (trace_event_get_state_backends(TRACE_COLO_COMPARE_MISCOMPARE)) {
199         char pri_ip_src[20], pri_ip_dst[20], sec_ip_src[20], sec_ip_dst[20];
200 
201         strcpy(pri_ip_src, inet_ntoa(ppkt->ip->ip_src));
202         strcpy(pri_ip_dst, inet_ntoa(ppkt->ip->ip_dst));
203         strcpy(sec_ip_src, inet_ntoa(spkt->ip->ip_src));
204         strcpy(sec_ip_dst, inet_ntoa(spkt->ip->ip_dst));
205 
206         trace_colo_compare_ip_info(ppkt->size, pri_ip_src,
207                                    pri_ip_dst, spkt->size,
208                                    sec_ip_src, sec_ip_dst);
209     }
210 
211     poffset = ppkt->vnet_hdr_len + poffset;
212     soffset = ppkt->vnet_hdr_len + soffset;
213 
214     if (ppkt->size - poffset == spkt->size - soffset) {
215         return memcmp(ppkt->data + poffset,
216                       spkt->data + soffset,
217                       spkt->size - soffset);
218     } else {
219         trace_colo_compare_main("Net packet size are not the same");
220         return -1;
221     }
222 }
223 
224 /*
225  * Called from the compare thread on the primary
226  * for compare tcp packet
227  * compare_tcp copied from Dr. David Alan Gilbert's branch
228  */
229 static int colo_packet_compare_tcp(Packet *spkt, Packet *ppkt)
230 {
231     struct tcphdr *ptcp, *stcp;
232     int res;
233 
234     trace_colo_compare_main("compare tcp");
235 
236     ptcp = (struct tcphdr *)ppkt->transport_header;
237     stcp = (struct tcphdr *)spkt->transport_header;
238 
239     /*
240      * The 'identification' field in the IP header is *very* random
241      * it almost never matches.  Fudge this by ignoring differences in
242      * unfragmented packets; they'll normally sort themselves out if different
243      * anyway, and it should recover at the TCP level.
244      * An alternative would be to get both the primary and secondary to rewrite
245      * somehow; but that would need some sync traffic to sync the state
246      */
247     if (ntohs(ppkt->ip->ip_off) & IP_DF) {
248         spkt->ip->ip_id = ppkt->ip->ip_id;
249         /* and the sum will be different if the IDs were different */
250         spkt->ip->ip_sum = ppkt->ip->ip_sum;
251     }
252 
253     /*
254      * Check tcp header length for tcp option field.
255      * th_off > 5 means this tcp packet have options field.
256      * The tcp options maybe always different.
257      * for example:
258      * From RFC 7323.
259      * TCP Timestamps option (TSopt):
260      * Kind: 8
261      *
262      * Length: 10 bytes
263      *
264      *    +-------+-------+---------------------+---------------------+
265      *    |Kind=8 |  10   |   TS Value (TSval)  |TS Echo Reply (TSecr)|
266      *    +-------+-------+---------------------+---------------------+
267      *       1       1              4                     4
268      *
269      * In this case the primary guest's timestamp always different with
270      * the secondary guest's timestamp. COLO just focus on payload,
271      * so we just need skip this field.
272      */
273     if (ptcp->th_off > 5) {
274         ptrdiff_t ptcp_offset, stcp_offset;
275 
276         ptcp_offset = ppkt->transport_header - (uint8_t *)ppkt->data
277                       + (ptcp->th_off * 4) - ppkt->vnet_hdr_len;
278         stcp_offset = spkt->transport_header - (uint8_t *)spkt->data
279                       + (stcp->th_off * 4) - spkt->vnet_hdr_len;
280 
281         /*
282          * When network is busy, some tcp options(like sack) will unpredictable
283          * occur in primary side or secondary side. it will make packet size
284          * not same, but the two packet's payload is identical. colo just
285          * care about packet payload, so we skip the option field.
286          */
287         res = colo_packet_compare_common(ppkt, spkt, ptcp_offset, stcp_offset);
288     } else if (ptcp->th_sum == stcp->th_sum) {
289         res = colo_packet_compare_common(ppkt, spkt, ETH_HLEN, ETH_HLEN);
290     } else {
291         res = -1;
292     }
293 
294     if (res != 0 &&
295         trace_event_get_state_backends(TRACE_COLO_COMPARE_MISCOMPARE)) {
296         char pri_ip_src[20], pri_ip_dst[20], sec_ip_src[20], sec_ip_dst[20];
297 
298         strcpy(pri_ip_src, inet_ntoa(ppkt->ip->ip_src));
299         strcpy(pri_ip_dst, inet_ntoa(ppkt->ip->ip_dst));
300         strcpy(sec_ip_src, inet_ntoa(spkt->ip->ip_src));
301         strcpy(sec_ip_dst, inet_ntoa(spkt->ip->ip_dst));
302 
303         trace_colo_compare_ip_info(ppkt->size, pri_ip_src,
304                                    pri_ip_dst, spkt->size,
305                                    sec_ip_src, sec_ip_dst);
306 
307         trace_colo_compare_tcp_info("pri tcp packet",
308                                     ntohl(ptcp->th_seq),
309                                     ntohl(ptcp->th_ack),
310                                     res, ptcp->th_flags,
311                                     ppkt->size);
312 
313         trace_colo_compare_tcp_info("sec tcp packet",
314                                     ntohl(stcp->th_seq),
315                                     ntohl(stcp->th_ack),
316                                     res, stcp->th_flags,
317                                     spkt->size);
318 
319         qemu_hexdump((char *)ppkt->data, stderr,
320                      "colo-compare ppkt", ppkt->size);
321         qemu_hexdump((char *)spkt->data, stderr,
322                      "colo-compare spkt", spkt->size);
323     }
324 
325     return res;
326 }
327 
328 /*
329  * Called from the compare thread on the primary
330  * for compare udp packet
331  */
332 static int colo_packet_compare_udp(Packet *spkt, Packet *ppkt)
333 {
334     int ret;
335     int network_header_length = ppkt->ip->ip_hl * 4;
336 
337     trace_colo_compare_main("compare udp");
338 
339     /*
340      * Because of ppkt and spkt are both in the same connection,
341      * The ppkt's src ip, dst ip, src port, dst port, ip_proto all are
342      * same with spkt. In addition, IP header's Identification is a random
343      * field, we can handle it in IP fragmentation function later.
344      * COLO just concern the response net packet payload from primary guest
345      * and secondary guest are same or not, So we ignored all IP header include
346      * other field like TOS,TTL,IP Checksum. we only need to compare
347      * the ip payload here.
348      */
349     ret = colo_packet_compare_common(ppkt, spkt,
350                                      network_header_length + ETH_HLEN,
351                                      network_header_length + ETH_HLEN);
352 
353     if (ret) {
354         trace_colo_compare_udp_miscompare("primary pkt size", ppkt->size);
355         trace_colo_compare_udp_miscompare("Secondary pkt size", spkt->size);
356         if (trace_event_get_state_backends(TRACE_COLO_COMPARE_MISCOMPARE)) {
357             qemu_hexdump((char *)ppkt->data, stderr, "colo-compare pri pkt",
358                          ppkt->size);
359             qemu_hexdump((char *)spkt->data, stderr, "colo-compare sec pkt",
360                          spkt->size);
361         }
362     }
363 
364     return ret;
365 }
366 
367 /*
368  * Called from the compare thread on the primary
369  * for compare icmp packet
370  */
371 static int colo_packet_compare_icmp(Packet *spkt, Packet *ppkt)
372 {
373     int network_header_length = ppkt->ip->ip_hl * 4;
374 
375     trace_colo_compare_main("compare icmp");
376 
377     /*
378      * Because of ppkt and spkt are both in the same connection,
379      * The ppkt's src ip, dst ip, src port, dst port, ip_proto all are
380      * same with spkt. In addition, IP header's Identification is a random
381      * field, we can handle it in IP fragmentation function later.
382      * COLO just concern the response net packet payload from primary guest
383      * and secondary guest are same or not, So we ignored all IP header include
384      * other field like TOS,TTL,IP Checksum. we only need to compare
385      * the ip payload here.
386      */
387     if (colo_packet_compare_common(ppkt, spkt,
388                                    network_header_length + ETH_HLEN,
389                                    network_header_length + ETH_HLEN)) {
390         trace_colo_compare_icmp_miscompare("primary pkt size",
391                                            ppkt->size);
392         trace_colo_compare_icmp_miscompare("Secondary pkt size",
393                                            spkt->size);
394         if (trace_event_get_state_backends(TRACE_COLO_COMPARE_MISCOMPARE)) {
395             qemu_hexdump((char *)ppkt->data, stderr, "colo-compare pri pkt",
396                          ppkt->size);
397             qemu_hexdump((char *)spkt->data, stderr, "colo-compare sec pkt",
398                          spkt->size);
399         }
400         return -1;
401     } else {
402         return 0;
403     }
404 }
405 
406 /*
407  * Called from the compare thread on the primary
408  * for compare other packet
409  */
410 static int colo_packet_compare_other(Packet *spkt, Packet *ppkt)
411 {
412     trace_colo_compare_main("compare other");
413     if (trace_event_get_state_backends(TRACE_COLO_COMPARE_MISCOMPARE)) {
414         char pri_ip_src[20], pri_ip_dst[20], sec_ip_src[20], sec_ip_dst[20];
415 
416         strcpy(pri_ip_src, inet_ntoa(ppkt->ip->ip_src));
417         strcpy(pri_ip_dst, inet_ntoa(ppkt->ip->ip_dst));
418         strcpy(sec_ip_src, inet_ntoa(spkt->ip->ip_src));
419         strcpy(sec_ip_dst, inet_ntoa(spkt->ip->ip_dst));
420 
421         trace_colo_compare_ip_info(ppkt->size, pri_ip_src,
422                                    pri_ip_dst, spkt->size,
423                                    sec_ip_src, sec_ip_dst);
424     }
425 
426     return colo_packet_compare_common(ppkt, spkt, 0, 0);
427 }
428 
429 static int colo_old_packet_check_one(Packet *pkt, int64_t *check_time)
430 {
431     int64_t now = qemu_clock_get_ms(QEMU_CLOCK_HOST);
432 
433     if ((now - pkt->creation_ms) > (*check_time)) {
434         trace_colo_old_packet_check_found(pkt->creation_ms);
435         return 0;
436     } else {
437         return 1;
438     }
439 }
440 
441 static int colo_old_packet_check_one_conn(Connection *conn,
442                                           void *user_data)
443 {
444     GList *result = NULL;
445     int64_t check_time = REGULAR_PACKET_CHECK_MS;
446 
447     result = g_queue_find_custom(&conn->primary_list,
448                                  &check_time,
449                                  (GCompareFunc)colo_old_packet_check_one);
450 
451     if (result) {
452         /* Do checkpoint will flush old packet */
453         /*
454          * TODO: Notify colo frame to do checkpoint.
455          * colo_compare_inconsistent_notify();
456          */
457         return 0;
458     }
459 
460     return 1;
461 }
462 
463 /*
464  * Look for old packets that the secondary hasn't matched,
465  * if we have some then we have to checkpoint to wake
466  * the secondary up.
467  */
468 static void colo_old_packet_check(void *opaque)
469 {
470     CompareState *s = opaque;
471 
472     /*
473      * If we find one old packet, stop finding job and notify
474      * COLO frame do checkpoint.
475      */
476     g_queue_find_custom(&s->conn_list, NULL,
477                         (GCompareFunc)colo_old_packet_check_one_conn);
478 }
479 
480 /*
481  * Called from the compare thread on the primary
482  * for compare packet with secondary list of the
483  * specified connection when a new packet was
484  * queued to it.
485  */
486 static void colo_compare_connection(void *opaque, void *user_data)
487 {
488     CompareState *s = user_data;
489     Connection *conn = opaque;
490     Packet *pkt = NULL;
491     GList *result = NULL;
492     int ret;
493 
494     while (!g_queue_is_empty(&conn->primary_list) &&
495            !g_queue_is_empty(&conn->secondary_list)) {
496         pkt = g_queue_pop_head(&conn->primary_list);
497         switch (conn->ip_proto) {
498         case IPPROTO_TCP:
499             result = g_queue_find_custom(&conn->secondary_list,
500                      pkt, (GCompareFunc)colo_packet_compare_tcp);
501             break;
502         case IPPROTO_UDP:
503             result = g_queue_find_custom(&conn->secondary_list,
504                      pkt, (GCompareFunc)colo_packet_compare_udp);
505             break;
506         case IPPROTO_ICMP:
507             result = g_queue_find_custom(&conn->secondary_list,
508                      pkt, (GCompareFunc)colo_packet_compare_icmp);
509             break;
510         default:
511             result = g_queue_find_custom(&conn->secondary_list,
512                      pkt, (GCompareFunc)colo_packet_compare_other);
513             break;
514         }
515 
516         if (result) {
517             ret = compare_chr_send(s,
518                                    pkt->data,
519                                    pkt->size,
520                                    pkt->vnet_hdr_len);
521             if (ret < 0) {
522                 error_report("colo_send_primary_packet failed");
523             }
524             trace_colo_compare_main("packet same and release packet");
525             g_queue_remove(&conn->secondary_list, result->data);
526             packet_destroy(pkt, NULL);
527         } else {
528             /*
529              * If one packet arrive late, the secondary_list or
530              * primary_list will be empty, so we can't compare it
531              * until next comparison.
532              */
533             trace_colo_compare_main("packet different");
534             g_queue_push_head(&conn->primary_list, pkt);
535             /* TODO: colo_notify_checkpoint();*/
536             break;
537         }
538     }
539 }
540 
541 static int compare_chr_send(CompareState *s,
542                             const uint8_t *buf,
543                             uint32_t size,
544                             uint32_t vnet_hdr_len)
545 {
546     int ret = 0;
547     uint32_t len = htonl(size);
548 
549     if (!size) {
550         return 0;
551     }
552 
553     ret = qemu_chr_fe_write_all(&s->chr_out, (uint8_t *)&len, sizeof(len));
554     if (ret != sizeof(len)) {
555         goto err;
556     }
557 
558     if (s->vnet_hdr) {
559         /*
560          * We send vnet header len make other module(like filter-redirector)
561          * know how to parse net packet correctly.
562          */
563         len = htonl(vnet_hdr_len);
564         ret = qemu_chr_fe_write_all(&s->chr_out, (uint8_t *)&len, sizeof(len));
565         if (ret != sizeof(len)) {
566             goto err;
567         }
568     }
569 
570     ret = qemu_chr_fe_write_all(&s->chr_out, (uint8_t *)buf, size);
571     if (ret != size) {
572         goto err;
573     }
574 
575     return 0;
576 
577 err:
578     return ret < 0 ? ret : -EIO;
579 }
580 
581 static int compare_chr_can_read(void *opaque)
582 {
583     return COMPARE_READ_LEN_MAX;
584 }
585 
586 /*
587  * Called from the main thread on the primary for packets
588  * arriving over the socket from the primary.
589  */
590 static void compare_pri_chr_in(void *opaque, const uint8_t *buf, int size)
591 {
592     CompareState *s = COLO_COMPARE(opaque);
593     int ret;
594 
595     ret = net_fill_rstate(&s->pri_rs, buf, size);
596     if (ret == -1) {
597         qemu_chr_fe_set_handlers(&s->chr_pri_in, NULL, NULL, NULL, NULL,
598                                  NULL, NULL, true);
599         error_report("colo-compare primary_in error");
600     }
601 }
602 
603 /*
604  * Called from the main thread on the primary for packets
605  * arriving over the socket from the secondary.
606  */
607 static void compare_sec_chr_in(void *opaque, const uint8_t *buf, int size)
608 {
609     CompareState *s = COLO_COMPARE(opaque);
610     int ret;
611 
612     ret = net_fill_rstate(&s->sec_rs, buf, size);
613     if (ret == -1) {
614         qemu_chr_fe_set_handlers(&s->chr_sec_in, NULL, NULL, NULL, NULL,
615                                  NULL, NULL, true);
616         error_report("colo-compare secondary_in error");
617     }
618 }
619 
620 /*
621  * Check old packet regularly so it can watch for any packets
622  * that the secondary hasn't produced equivalents of.
623  */
624 static void check_old_packet_regular(void *opaque)
625 {
626     CompareState *s = opaque;
627 
628     /* if have old packet we will notify checkpoint */
629     colo_old_packet_check(s);
630     timer_mod(s->packet_check_timer, qemu_clock_get_ms(QEMU_CLOCK_VIRTUAL) +
631                 REGULAR_PACKET_CHECK_MS);
632 }
633 
634 static void colo_compare_timer_init(CompareState *s)
635 {
636     AioContext *ctx = iothread_get_aio_context(s->iothread);
637 
638     s->packet_check_timer = aio_timer_new(ctx, QEMU_CLOCK_VIRTUAL,
639                                 SCALE_MS, check_old_packet_regular,
640                                 s);
641     timer_mod(s->packet_check_timer, qemu_clock_get_ms(QEMU_CLOCK_VIRTUAL) +
642                     REGULAR_PACKET_CHECK_MS);
643 }
644 
645 static void colo_compare_timer_del(CompareState *s)
646 {
647     if (s->packet_check_timer) {
648         timer_del(s->packet_check_timer);
649         timer_free(s->packet_check_timer);
650         s->packet_check_timer = NULL;
651     }
652  }
653 
654 static void colo_compare_iothread(CompareState *s)
655 {
656     object_ref(OBJECT(s->iothread));
657     s->worker_context = iothread_get_g_main_context(s->iothread);
658 
659     qemu_chr_fe_set_handlers(&s->chr_pri_in, compare_chr_can_read,
660                              compare_pri_chr_in, NULL, NULL,
661                              s, s->worker_context, true);
662     qemu_chr_fe_set_handlers(&s->chr_sec_in, compare_chr_can_read,
663                              compare_sec_chr_in, NULL, NULL,
664                              s, s->worker_context, true);
665 
666     colo_compare_timer_init(s);
667 }
668 
669 static char *compare_get_pri_indev(Object *obj, Error **errp)
670 {
671     CompareState *s = COLO_COMPARE(obj);
672 
673     return g_strdup(s->pri_indev);
674 }
675 
676 static void compare_set_pri_indev(Object *obj, const char *value, Error **errp)
677 {
678     CompareState *s = COLO_COMPARE(obj);
679 
680     g_free(s->pri_indev);
681     s->pri_indev = g_strdup(value);
682 }
683 
684 static char *compare_get_sec_indev(Object *obj, Error **errp)
685 {
686     CompareState *s = COLO_COMPARE(obj);
687 
688     return g_strdup(s->sec_indev);
689 }
690 
691 static void compare_set_sec_indev(Object *obj, const char *value, Error **errp)
692 {
693     CompareState *s = COLO_COMPARE(obj);
694 
695     g_free(s->sec_indev);
696     s->sec_indev = g_strdup(value);
697 }
698 
699 static char *compare_get_outdev(Object *obj, Error **errp)
700 {
701     CompareState *s = COLO_COMPARE(obj);
702 
703     return g_strdup(s->outdev);
704 }
705 
706 static void compare_set_outdev(Object *obj, const char *value, Error **errp)
707 {
708     CompareState *s = COLO_COMPARE(obj);
709 
710     g_free(s->outdev);
711     s->outdev = g_strdup(value);
712 }
713 
714 static bool compare_get_vnet_hdr(Object *obj, Error **errp)
715 {
716     CompareState *s = COLO_COMPARE(obj);
717 
718     return s->vnet_hdr;
719 }
720 
721 static void compare_set_vnet_hdr(Object *obj,
722                                  bool value,
723                                  Error **errp)
724 {
725     CompareState *s = COLO_COMPARE(obj);
726 
727     s->vnet_hdr = value;
728 }
729 
730 static void compare_pri_rs_finalize(SocketReadState *pri_rs)
731 {
732     CompareState *s = container_of(pri_rs, CompareState, pri_rs);
733     Connection *conn = NULL;
734 
735     if (packet_enqueue(s, PRIMARY_IN, &conn)) {
736         trace_colo_compare_main("primary: unsupported packet in");
737         compare_chr_send(s,
738                          pri_rs->buf,
739                          pri_rs->packet_len,
740                          pri_rs->vnet_hdr_len);
741     } else {
742         /* compare packet in the specified connection */
743         colo_compare_connection(conn, s);
744     }
745 }
746 
747 static void compare_sec_rs_finalize(SocketReadState *sec_rs)
748 {
749     CompareState *s = container_of(sec_rs, CompareState, sec_rs);
750     Connection *conn = NULL;
751 
752     if (packet_enqueue(s, SECONDARY_IN, &conn)) {
753         trace_colo_compare_main("secondary: unsupported packet in");
754     } else {
755         /* compare packet in the specified connection */
756         colo_compare_connection(conn, s);
757     }
758 }
759 
760 
761 /*
762  * Return 0 is success.
763  * Return 1 is failed.
764  */
765 static int find_and_check_chardev(Chardev **chr,
766                                   char *chr_name,
767                                   Error **errp)
768 {
769     *chr = qemu_chr_find(chr_name);
770     if (*chr == NULL) {
771         error_setg(errp, "Device '%s' not found",
772                    chr_name);
773         return 1;
774     }
775 
776     if (!qemu_chr_has_feature(*chr, QEMU_CHAR_FEATURE_RECONNECTABLE)) {
777         error_setg(errp, "chardev \"%s\" is not reconnectable",
778                    chr_name);
779         return 1;
780     }
781 
782     return 0;
783 }
784 
785 /*
786  * Called from the main thread on the primary
787  * to setup colo-compare.
788  */
789 static void colo_compare_complete(UserCreatable *uc, Error **errp)
790 {
791     CompareState *s = COLO_COMPARE(uc);
792     Chardev *chr;
793 
794     if (!s->pri_indev || !s->sec_indev || !s->outdev || !s->iothread) {
795         error_setg(errp, "colo compare needs 'primary_in' ,"
796                    "'secondary_in','outdev','iothread' property set");
797         return;
798     } else if (!strcmp(s->pri_indev, s->outdev) ||
799                !strcmp(s->sec_indev, s->outdev) ||
800                !strcmp(s->pri_indev, s->sec_indev)) {
801         error_setg(errp, "'indev' and 'outdev' could not be same "
802                    "for compare module");
803         return;
804     }
805 
806     if (find_and_check_chardev(&chr, s->pri_indev, errp) ||
807         !qemu_chr_fe_init(&s->chr_pri_in, chr, errp)) {
808         return;
809     }
810 
811     if (find_and_check_chardev(&chr, s->sec_indev, errp) ||
812         !qemu_chr_fe_init(&s->chr_sec_in, chr, errp)) {
813         return;
814     }
815 
816     if (find_and_check_chardev(&chr, s->outdev, errp) ||
817         !qemu_chr_fe_init(&s->chr_out, chr, errp)) {
818         return;
819     }
820 
821     net_socket_rs_init(&s->pri_rs, compare_pri_rs_finalize, s->vnet_hdr);
822     net_socket_rs_init(&s->sec_rs, compare_sec_rs_finalize, s->vnet_hdr);
823 
824     g_queue_init(&s->conn_list);
825 
826     s->connection_track_table = g_hash_table_new_full(connection_key_hash,
827                                                       connection_key_equal,
828                                                       g_free,
829                                                       connection_destroy);
830 
831     colo_compare_iothread(s);
832     return;
833 }
834 
835 static void colo_flush_packets(void *opaque, void *user_data)
836 {
837     CompareState *s = user_data;
838     Connection *conn = opaque;
839     Packet *pkt = NULL;
840 
841     while (!g_queue_is_empty(&conn->primary_list)) {
842         pkt = g_queue_pop_head(&conn->primary_list);
843         compare_chr_send(s,
844                          pkt->data,
845                          pkt->size,
846                          pkt->vnet_hdr_len);
847         packet_destroy(pkt, NULL);
848     }
849     while (!g_queue_is_empty(&conn->secondary_list)) {
850         pkt = g_queue_pop_head(&conn->secondary_list);
851         packet_destroy(pkt, NULL);
852     }
853 }
854 
855 static void colo_compare_class_init(ObjectClass *oc, void *data)
856 {
857     UserCreatableClass *ucc = USER_CREATABLE_CLASS(oc);
858 
859     ucc->complete = colo_compare_complete;
860 }
861 
862 static void colo_compare_init(Object *obj)
863 {
864     CompareState *s = COLO_COMPARE(obj);
865 
866     object_property_add_str(obj, "primary_in",
867                             compare_get_pri_indev, compare_set_pri_indev,
868                             NULL);
869     object_property_add_str(obj, "secondary_in",
870                             compare_get_sec_indev, compare_set_sec_indev,
871                             NULL);
872     object_property_add_str(obj, "outdev",
873                             compare_get_outdev, compare_set_outdev,
874                             NULL);
875     object_property_add_link(obj, "iothread", TYPE_IOTHREAD,
876                             (Object **)&s->iothread,
877                             object_property_allow_set_link,
878                             OBJ_PROP_LINK_UNREF_ON_RELEASE, NULL);
879 
880     s->vnet_hdr = false;
881     object_property_add_bool(obj, "vnet_hdr_support", compare_get_vnet_hdr,
882                              compare_set_vnet_hdr, NULL);
883 }
884 
885 static void colo_compare_finalize(Object *obj)
886 {
887     CompareState *s = COLO_COMPARE(obj);
888 
889     qemu_chr_fe_deinit(&s->chr_pri_in, false);
890     qemu_chr_fe_deinit(&s->chr_sec_in, false);
891     qemu_chr_fe_deinit(&s->chr_out, false);
892     if (s->iothread) {
893         colo_compare_timer_del(s);
894     }
895     /* Release all unhandled packets after compare thead exited */
896     g_queue_foreach(&s->conn_list, colo_flush_packets, s);
897 
898     g_queue_clear(&s->conn_list);
899 
900     if (s->connection_track_table) {
901         g_hash_table_destroy(s->connection_track_table);
902     }
903 
904     if (s->iothread) {
905         object_unref(OBJECT(s->iothread));
906     }
907     g_free(s->pri_indev);
908     g_free(s->sec_indev);
909     g_free(s->outdev);
910 }
911 
912 static const TypeInfo colo_compare_info = {
913     .name = TYPE_COLO_COMPARE,
914     .parent = TYPE_OBJECT,
915     .instance_size = sizeof(CompareState),
916     .instance_init = colo_compare_init,
917     .instance_finalize = colo_compare_finalize,
918     .class_size = sizeof(CompareClass),
919     .class_init = colo_compare_class_init,
920     .interfaces = (InterfaceInfo[]) {
921         { TYPE_USER_CREATABLE },
922         { }
923     }
924 };
925 
926 static void register_types(void)
927 {
928     type_register_static(&colo_compare_info);
929 }
930 
931 type_init(register_types);
932