xref: /openbmc/qemu/net/colo-compare.c (revision ec603b55)
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 "chardev/char-fe.h"
29 #include "qemu/sockets.h"
30 #include "qapi-visit.h"
31 #include "net/colo.h"
32 #include "sysemu/iothread.h"
33 
34 #define TYPE_COLO_COMPARE "colo-compare"
35 #define COLO_COMPARE(obj) \
36     OBJECT_CHECK(CompareState, (obj), TYPE_COLO_COMPARE)
37 
38 #define COMPARE_READ_LEN_MAX NET_BUFSIZE
39 #define MAX_QUEUE_SIZE 1024
40 
41 /* TODO: Should be configurable */
42 #define REGULAR_PACKET_CHECK_MS 3000
43 
44 /*
45  *  + CompareState ++
46  *  |               |
47  *  +---------------+   +---------------+         +---------------+
48  *  |   conn list   + - >      conn     + ------- >      conn     + -- > ......
49  *  +---------------+   +---------------+         +---------------+
50  *  |               |     |           |             |          |
51  *  +---------------+ +---v----+  +---v----+    +---v----+ +---v----+
52  *                    |primary |  |secondary    |primary | |secondary
53  *                    |packet  |  |packet  +    |packet  | |packet  +
54  *                    +--------+  +--------+    +--------+ +--------+
55  *                        |           |             |          |
56  *                    +---v----+  +---v----+    +---v----+ +---v----+
57  *                    |primary |  |secondary    |primary | |secondary
58  *                    |packet  |  |packet  +    |packet  | |packet  +
59  *                    +--------+  +--------+    +--------+ +--------+
60  *                        |           |             |          |
61  *                    +---v----+  +---v----+    +---v----+ +---v----+
62  *                    |primary |  |secondary    |primary | |secondary
63  *                    |packet  |  |packet  +    |packet  | |packet  +
64  *                    +--------+  +--------+    +--------+ +--------+
65  */
66 typedef struct CompareState {
67     Object parent;
68 
69     char *pri_indev;
70     char *sec_indev;
71     char *outdev;
72     CharBackend chr_pri_in;
73     CharBackend chr_sec_in;
74     CharBackend chr_out;
75     SocketReadState pri_rs;
76     SocketReadState sec_rs;
77     bool vnet_hdr;
78 
79     /*
80      * Record the connection that through the NIC
81      * Element type: Connection
82      */
83     GQueue conn_list;
84     /* Record the connection without repetition */
85     GHashTable *connection_track_table;
86 
87     IOThread *iothread;
88     GMainContext *worker_context;
89     QEMUTimer *packet_check_timer;
90 } CompareState;
91 
92 typedef struct CompareClass {
93     ObjectClass parent_class;
94 } CompareClass;
95 
96 enum {
97     PRIMARY_IN = 0,
98     SECONDARY_IN,
99 };
100 
101 static int compare_chr_send(CompareState *s,
102                             const uint8_t *buf,
103                             uint32_t size,
104                             uint32_t vnet_hdr_len);
105 
106 static gint seq_sorter(Packet *a, Packet *b, gpointer data)
107 {
108     struct tcphdr *atcp, *btcp;
109 
110     atcp = (struct tcphdr *)(a->transport_header);
111     btcp = (struct tcphdr *)(b->transport_header);
112     return ntohl(atcp->th_seq) - ntohl(btcp->th_seq);
113 }
114 
115 /*
116  * Return 1 on success, if return 0 means the
117  * packet will be dropped
118  */
119 static int colo_insert_packet(GQueue *queue, Packet *pkt)
120 {
121     if (g_queue_get_length(queue) <= MAX_QUEUE_SIZE) {
122         if (pkt->ip->ip_p == IPPROTO_TCP) {
123             g_queue_insert_sorted(queue,
124                                   pkt,
125                                   (GCompareDataFunc)seq_sorter,
126                                   NULL);
127         } else {
128             g_queue_push_tail(queue, pkt);
129         }
130         return 1;
131     }
132     return 0;
133 }
134 
135 /*
136  * Return 0 on success, if return -1 means the pkt
137  * is unsupported(arp and ipv6) and will be sent later
138  */
139 static int packet_enqueue(CompareState *s, int mode, Connection **con)
140 {
141     ConnectionKey key;
142     Packet *pkt = NULL;
143     Connection *conn;
144 
145     if (mode == PRIMARY_IN) {
146         pkt = packet_new(s->pri_rs.buf,
147                          s->pri_rs.packet_len,
148                          s->pri_rs.vnet_hdr_len);
149     } else {
150         pkt = packet_new(s->sec_rs.buf,
151                          s->sec_rs.packet_len,
152                          s->sec_rs.vnet_hdr_len);
153     }
154 
155     if (parse_packet_early(pkt)) {
156         packet_destroy(pkt, NULL);
157         pkt = NULL;
158         return -1;
159     }
160     fill_connection_key(pkt, &key);
161 
162     conn = connection_get(s->connection_track_table,
163                           &key,
164                           &s->conn_list);
165 
166     if (!conn->processing) {
167         g_queue_push_tail(&s->conn_list, conn);
168         conn->processing = true;
169     }
170 
171     if (mode == PRIMARY_IN) {
172         if (!colo_insert_packet(&conn->primary_list, pkt)) {
173             error_report("colo compare primary queue size too big,"
174                          "drop packet");
175         }
176     } else {
177         if (!colo_insert_packet(&conn->secondary_list, pkt)) {
178             error_report("colo compare secondary queue size too big,"
179                          "drop packet");
180         }
181     }
182     con = &conn;
183 
184     return 0;
185 }
186 
187 /*
188  * The IP packets sent by primary and secondary
189  * will be compared in here
190  * TODO support ip fragment, Out-Of-Order
191  * return:    0  means packet same
192  *            > 0 || < 0 means packet different
193  */
194 static int colo_packet_compare_common(Packet *ppkt,
195                                       Packet *spkt,
196                                       int poffset,
197                                       int soffset)
198 {
199     if (trace_event_get_state_backends(TRACE_COLO_COMPARE_MISCOMPARE)) {
200         char pri_ip_src[20], pri_ip_dst[20], sec_ip_src[20], sec_ip_dst[20];
201 
202         strcpy(pri_ip_src, inet_ntoa(ppkt->ip->ip_src));
203         strcpy(pri_ip_dst, inet_ntoa(ppkt->ip->ip_dst));
204         strcpy(sec_ip_src, inet_ntoa(spkt->ip->ip_src));
205         strcpy(sec_ip_dst, inet_ntoa(spkt->ip->ip_dst));
206 
207         trace_colo_compare_ip_info(ppkt->size, pri_ip_src,
208                                    pri_ip_dst, spkt->size,
209                                    sec_ip_src, sec_ip_dst);
210     }
211 
212     poffset = ppkt->vnet_hdr_len + poffset;
213     soffset = ppkt->vnet_hdr_len + soffset;
214 
215     if (ppkt->size - poffset == spkt->size - soffset) {
216         return memcmp(ppkt->data + poffset,
217                       spkt->data + soffset,
218                       spkt->size - soffset);
219     } else {
220         trace_colo_compare_main("Net packet size are not the same");
221         return -1;
222     }
223 }
224 
225 /*
226  * Called from the compare thread on the primary
227  * for compare tcp packet
228  * compare_tcp copied from Dr. David Alan Gilbert's branch
229  */
230 static int colo_packet_compare_tcp(Packet *spkt, Packet *ppkt)
231 {
232     struct tcphdr *ptcp, *stcp;
233     int res;
234 
235     trace_colo_compare_main("compare tcp");
236 
237     ptcp = (struct tcphdr *)ppkt->transport_header;
238     stcp = (struct tcphdr *)spkt->transport_header;
239 
240     /*
241      * The 'identification' field in the IP header is *very* random
242      * it almost never matches.  Fudge this by ignoring differences in
243      * unfragmented packets; they'll normally sort themselves out if different
244      * anyway, and it should recover at the TCP level.
245      * An alternative would be to get both the primary and secondary to rewrite
246      * somehow; but that would need some sync traffic to sync the state
247      */
248     if (ntohs(ppkt->ip->ip_off) & IP_DF) {
249         spkt->ip->ip_id = ppkt->ip->ip_id;
250         /* and the sum will be different if the IDs were different */
251         spkt->ip->ip_sum = ppkt->ip->ip_sum;
252     }
253 
254     /*
255      * Check tcp header length for tcp option field.
256      * th_off > 5 means this tcp packet have options field.
257      * The tcp options maybe always different.
258      * for example:
259      * From RFC 7323.
260      * TCP Timestamps option (TSopt):
261      * Kind: 8
262      *
263      * Length: 10 bytes
264      *
265      *    +-------+-------+---------------------+---------------------+
266      *    |Kind=8 |  10   |   TS Value (TSval)  |TS Echo Reply (TSecr)|
267      *    +-------+-------+---------------------+---------------------+
268      *       1       1              4                     4
269      *
270      * In this case the primary guest's timestamp always different with
271      * the secondary guest's timestamp. COLO just focus on payload,
272      * so we just need skip this field.
273      */
274     if (ptcp->th_off > 5) {
275         ptrdiff_t ptcp_offset, stcp_offset;
276 
277         ptcp_offset = ppkt->transport_header - (uint8_t *)ppkt->data
278                       + (ptcp->th_off * 4) - ppkt->vnet_hdr_len;
279         stcp_offset = spkt->transport_header - (uint8_t *)spkt->data
280                       + (stcp->th_off * 4) - spkt->vnet_hdr_len;
281 
282         /*
283          * When network is busy, some tcp options(like sack) will unpredictable
284          * occur in primary side or secondary side. it will make packet size
285          * not same, but the two packet's payload is identical. colo just
286          * care about packet payload, so we skip the option field.
287          */
288         res = colo_packet_compare_common(ppkt, spkt, ptcp_offset, stcp_offset);
289     } else if (ptcp->th_sum == stcp->th_sum) {
290         res = colo_packet_compare_common(ppkt, spkt, ETH_HLEN, ETH_HLEN);
291     } else {
292         res = -1;
293     }
294 
295     if (res != 0 &&
296         trace_event_get_state_backends(TRACE_COLO_COMPARE_MISCOMPARE)) {
297         char pri_ip_src[20], pri_ip_dst[20], sec_ip_src[20], sec_ip_dst[20];
298 
299         strcpy(pri_ip_src, inet_ntoa(ppkt->ip->ip_src));
300         strcpy(pri_ip_dst, inet_ntoa(ppkt->ip->ip_dst));
301         strcpy(sec_ip_src, inet_ntoa(spkt->ip->ip_src));
302         strcpy(sec_ip_dst, inet_ntoa(spkt->ip->ip_dst));
303 
304         trace_colo_compare_ip_info(ppkt->size, pri_ip_src,
305                                    pri_ip_dst, spkt->size,
306                                    sec_ip_src, sec_ip_dst);
307 
308         trace_colo_compare_tcp_info("pri tcp packet",
309                                     ntohl(ptcp->th_seq),
310                                     ntohl(ptcp->th_ack),
311                                     res, ptcp->th_flags,
312                                     ppkt->size);
313 
314         trace_colo_compare_tcp_info("sec tcp packet",
315                                     ntohl(stcp->th_seq),
316                                     ntohl(stcp->th_ack),
317                                     res, stcp->th_flags,
318                                     spkt->size);
319 
320         qemu_hexdump((char *)ppkt->data, stderr,
321                      "colo-compare ppkt", ppkt->size);
322         qemu_hexdump((char *)spkt->data, stderr,
323                      "colo-compare spkt", spkt->size);
324     }
325 
326     return res;
327 }
328 
329 /*
330  * Called from the compare thread on the primary
331  * for compare udp packet
332  */
333 static int colo_packet_compare_udp(Packet *spkt, Packet *ppkt)
334 {
335     int ret;
336     int network_header_length = ppkt->ip->ip_hl * 4;
337 
338     trace_colo_compare_main("compare udp");
339 
340     /*
341      * Because of ppkt and spkt are both in the same connection,
342      * The ppkt's src ip, dst ip, src port, dst port, ip_proto all are
343      * same with spkt. In addition, IP header's Identification is a random
344      * field, we can handle it in IP fragmentation function later.
345      * COLO just concern the response net packet payload from primary guest
346      * and secondary guest are same or not, So we ignored all IP header include
347      * other field like TOS,TTL,IP Checksum. we only need to compare
348      * the ip payload here.
349      */
350     ret = colo_packet_compare_common(ppkt, spkt,
351                                      network_header_length + ETH_HLEN,
352                                      network_header_length + ETH_HLEN);
353 
354     if (ret) {
355         trace_colo_compare_udp_miscompare("primary pkt size", ppkt->size);
356         trace_colo_compare_udp_miscompare("Secondary pkt size", spkt->size);
357         if (trace_event_get_state_backends(TRACE_COLO_COMPARE_MISCOMPARE)) {
358             qemu_hexdump((char *)ppkt->data, stderr, "colo-compare pri pkt",
359                          ppkt->size);
360             qemu_hexdump((char *)spkt->data, stderr, "colo-compare sec pkt",
361                          spkt->size);
362         }
363     }
364 
365     return ret;
366 }
367 
368 /*
369  * Called from the compare thread on the primary
370  * for compare icmp packet
371  */
372 static int colo_packet_compare_icmp(Packet *spkt, Packet *ppkt)
373 {
374     int network_header_length = ppkt->ip->ip_hl * 4;
375 
376     trace_colo_compare_main("compare icmp");
377 
378     /*
379      * Because of ppkt and spkt are both in the same connection,
380      * The ppkt's src ip, dst ip, src port, dst port, ip_proto all are
381      * same with spkt. In addition, IP header's Identification is a random
382      * field, we can handle it in IP fragmentation function later.
383      * COLO just concern the response net packet payload from primary guest
384      * and secondary guest are same or not, So we ignored all IP header include
385      * other field like TOS,TTL,IP Checksum. we only need to compare
386      * the ip payload here.
387      */
388     if (colo_packet_compare_common(ppkt, spkt,
389                                    network_header_length + ETH_HLEN,
390                                    network_header_length + ETH_HLEN)) {
391         trace_colo_compare_icmp_miscompare("primary pkt size",
392                                            ppkt->size);
393         trace_colo_compare_icmp_miscompare("Secondary pkt size",
394                                            spkt->size);
395         if (trace_event_get_state_backends(TRACE_COLO_COMPARE_MISCOMPARE)) {
396             qemu_hexdump((char *)ppkt->data, stderr, "colo-compare pri pkt",
397                          ppkt->size);
398             qemu_hexdump((char *)spkt->data, stderr, "colo-compare sec pkt",
399                          spkt->size);
400         }
401         return -1;
402     } else {
403         return 0;
404     }
405 }
406 
407 /*
408  * Called from the compare thread on the primary
409  * for compare other packet
410  */
411 static int colo_packet_compare_other(Packet *spkt, Packet *ppkt)
412 {
413     trace_colo_compare_main("compare other");
414     if (trace_event_get_state_backends(TRACE_COLO_COMPARE_MISCOMPARE)) {
415         char pri_ip_src[20], pri_ip_dst[20], sec_ip_src[20], sec_ip_dst[20];
416 
417         strcpy(pri_ip_src, inet_ntoa(ppkt->ip->ip_src));
418         strcpy(pri_ip_dst, inet_ntoa(ppkt->ip->ip_dst));
419         strcpy(sec_ip_src, inet_ntoa(spkt->ip->ip_src));
420         strcpy(sec_ip_dst, inet_ntoa(spkt->ip->ip_dst));
421 
422         trace_colo_compare_ip_info(ppkt->size, pri_ip_src,
423                                    pri_ip_dst, spkt->size,
424                                    sec_ip_src, sec_ip_dst);
425     }
426 
427     return colo_packet_compare_common(ppkt, spkt, 0, 0);
428 }
429 
430 static int colo_old_packet_check_one(Packet *pkt, int64_t *check_time)
431 {
432     int64_t now = qemu_clock_get_ms(QEMU_CLOCK_HOST);
433 
434     if ((now - pkt->creation_ms) > (*check_time)) {
435         trace_colo_old_packet_check_found(pkt->creation_ms);
436         return 0;
437     } else {
438         return 1;
439     }
440 }
441 
442 static int colo_old_packet_check_one_conn(Connection *conn,
443                                           void *user_data)
444 {
445     GList *result = NULL;
446     int64_t check_time = REGULAR_PACKET_CHECK_MS;
447 
448     result = g_queue_find_custom(&conn->primary_list,
449                                  &check_time,
450                                  (GCompareFunc)colo_old_packet_check_one);
451 
452     if (result) {
453         /* Do checkpoint will flush old packet */
454         /*
455          * TODO: Notify colo frame to do checkpoint.
456          * colo_compare_inconsistent_notify();
457          */
458         return 0;
459     }
460 
461     return 1;
462 }
463 
464 /*
465  * Look for old packets that the secondary hasn't matched,
466  * if we have some then we have to checkpoint to wake
467  * the secondary up.
468  */
469 static void colo_old_packet_check(void *opaque)
470 {
471     CompareState *s = opaque;
472 
473     /*
474      * If we find one old packet, stop finding job and notify
475      * COLO frame do checkpoint.
476      */
477     g_queue_find_custom(&s->conn_list, NULL,
478                         (GCompareFunc)colo_old_packet_check_one_conn);
479 }
480 
481 /*
482  * Called from the compare thread on the primary
483  * for compare packet with secondary list of the
484  * specified connection when a new packet was
485  * queued to it.
486  */
487 static void colo_compare_connection(void *opaque, void *user_data)
488 {
489     CompareState *s = user_data;
490     Connection *conn = opaque;
491     Packet *pkt = NULL;
492     GList *result = NULL;
493     int ret;
494 
495     while (!g_queue_is_empty(&conn->primary_list) &&
496            !g_queue_is_empty(&conn->secondary_list)) {
497         pkt = g_queue_pop_head(&conn->primary_list);
498         switch (conn->ip_proto) {
499         case IPPROTO_TCP:
500             result = g_queue_find_custom(&conn->secondary_list,
501                      pkt, (GCompareFunc)colo_packet_compare_tcp);
502             break;
503         case IPPROTO_UDP:
504             result = g_queue_find_custom(&conn->secondary_list,
505                      pkt, (GCompareFunc)colo_packet_compare_udp);
506             break;
507         case IPPROTO_ICMP:
508             result = g_queue_find_custom(&conn->secondary_list,
509                      pkt, (GCompareFunc)colo_packet_compare_icmp);
510             break;
511         default:
512             result = g_queue_find_custom(&conn->secondary_list,
513                      pkt, (GCompareFunc)colo_packet_compare_other);
514             break;
515         }
516 
517         if (result) {
518             ret = compare_chr_send(s,
519                                    pkt->data,
520                                    pkt->size,
521                                    pkt->vnet_hdr_len);
522             if (ret < 0) {
523                 error_report("colo_send_primary_packet failed");
524             }
525             trace_colo_compare_main("packet same and release packet");
526             g_queue_remove(&conn->secondary_list, result->data);
527             packet_destroy(pkt, NULL);
528         } else {
529             /*
530              * If one packet arrive late, the secondary_list or
531              * primary_list will be empty, so we can't compare it
532              * until next comparison.
533              */
534             trace_colo_compare_main("packet different");
535             g_queue_push_head(&conn->primary_list, pkt);
536             /* TODO: colo_notify_checkpoint();*/
537             break;
538         }
539     }
540 }
541 
542 static int compare_chr_send(CompareState *s,
543                             const uint8_t *buf,
544                             uint32_t size,
545                             uint32_t vnet_hdr_len)
546 {
547     int ret = 0;
548     uint32_t len = htonl(size);
549 
550     if (!size) {
551         return 0;
552     }
553 
554     ret = qemu_chr_fe_write_all(&s->chr_out, (uint8_t *)&len, sizeof(len));
555     if (ret != sizeof(len)) {
556         goto err;
557     }
558 
559     if (s->vnet_hdr) {
560         /*
561          * We send vnet header len make other module(like filter-redirector)
562          * know how to parse net packet correctly.
563          */
564         len = htonl(vnet_hdr_len);
565         ret = qemu_chr_fe_write_all(&s->chr_out, (uint8_t *)&len, sizeof(len));
566         if (ret != sizeof(len)) {
567             goto err;
568         }
569     }
570 
571     ret = qemu_chr_fe_write_all(&s->chr_out, (uint8_t *)buf, size);
572     if (ret != size) {
573         goto err;
574     }
575 
576     return 0;
577 
578 err:
579     return ret < 0 ? ret : -EIO;
580 }
581 
582 static int compare_chr_can_read(void *opaque)
583 {
584     return COMPARE_READ_LEN_MAX;
585 }
586 
587 /*
588  * Called from the main thread on the primary for packets
589  * arriving over the socket from the primary.
590  */
591 static void compare_pri_chr_in(void *opaque, const uint8_t *buf, int size)
592 {
593     CompareState *s = COLO_COMPARE(opaque);
594     int ret;
595 
596     ret = net_fill_rstate(&s->pri_rs, buf, size);
597     if (ret == -1) {
598         qemu_chr_fe_set_handlers(&s->chr_pri_in, NULL, NULL, NULL, NULL,
599                                  NULL, NULL, true);
600         error_report("colo-compare primary_in error");
601     }
602 }
603 
604 /*
605  * Called from the main thread on the primary for packets
606  * arriving over the socket from the secondary.
607  */
608 static void compare_sec_chr_in(void *opaque, const uint8_t *buf, int size)
609 {
610     CompareState *s = COLO_COMPARE(opaque);
611     int ret;
612 
613     ret = net_fill_rstate(&s->sec_rs, buf, size);
614     if (ret == -1) {
615         qemu_chr_fe_set_handlers(&s->chr_sec_in, NULL, NULL, NULL, NULL,
616                                  NULL, NULL, true);
617         error_report("colo-compare secondary_in error");
618     }
619 }
620 
621 /*
622  * Check old packet regularly so it can watch for any packets
623  * that the secondary hasn't produced equivalents of.
624  */
625 static void check_old_packet_regular(void *opaque)
626 {
627     CompareState *s = opaque;
628 
629     /* if have old packet we will notify checkpoint */
630     colo_old_packet_check(s);
631     timer_mod(s->packet_check_timer, qemu_clock_get_ms(QEMU_CLOCK_VIRTUAL) +
632                 REGULAR_PACKET_CHECK_MS);
633 }
634 
635 static void colo_compare_timer_init(CompareState *s)
636 {
637     AioContext *ctx = iothread_get_aio_context(s->iothread);
638 
639     s->packet_check_timer = aio_timer_new(ctx, QEMU_CLOCK_VIRTUAL,
640                                 SCALE_MS, check_old_packet_regular,
641                                 s);
642     timer_mod(s->packet_check_timer, qemu_clock_get_ms(QEMU_CLOCK_VIRTUAL) +
643                     REGULAR_PACKET_CHECK_MS);
644 }
645 
646 static void colo_compare_timer_del(CompareState *s)
647 {
648     if (s->packet_check_timer) {
649         timer_del(s->packet_check_timer);
650         timer_free(s->packet_check_timer);
651         s->packet_check_timer = NULL;
652     }
653  }
654 
655 static void colo_compare_iothread(CompareState *s)
656 {
657     object_ref(OBJECT(s->iothread));
658     s->worker_context = iothread_get_g_main_context(s->iothread);
659 
660     qemu_chr_fe_set_handlers(&s->chr_pri_in, compare_chr_can_read,
661                              compare_pri_chr_in, NULL, NULL,
662                              s, s->worker_context, true);
663     qemu_chr_fe_set_handlers(&s->chr_sec_in, compare_chr_can_read,
664                              compare_sec_chr_in, NULL, NULL,
665                              s, s->worker_context, true);
666 
667     colo_compare_timer_init(s);
668 }
669 
670 static char *compare_get_pri_indev(Object *obj, Error **errp)
671 {
672     CompareState *s = COLO_COMPARE(obj);
673 
674     return g_strdup(s->pri_indev);
675 }
676 
677 static void compare_set_pri_indev(Object *obj, const char *value, Error **errp)
678 {
679     CompareState *s = COLO_COMPARE(obj);
680 
681     g_free(s->pri_indev);
682     s->pri_indev = g_strdup(value);
683 }
684 
685 static char *compare_get_sec_indev(Object *obj, Error **errp)
686 {
687     CompareState *s = COLO_COMPARE(obj);
688 
689     return g_strdup(s->sec_indev);
690 }
691 
692 static void compare_set_sec_indev(Object *obj, const char *value, Error **errp)
693 {
694     CompareState *s = COLO_COMPARE(obj);
695 
696     g_free(s->sec_indev);
697     s->sec_indev = g_strdup(value);
698 }
699 
700 static char *compare_get_outdev(Object *obj, Error **errp)
701 {
702     CompareState *s = COLO_COMPARE(obj);
703 
704     return g_strdup(s->outdev);
705 }
706 
707 static void compare_set_outdev(Object *obj, const char *value, Error **errp)
708 {
709     CompareState *s = COLO_COMPARE(obj);
710 
711     g_free(s->outdev);
712     s->outdev = g_strdup(value);
713 }
714 
715 static bool compare_get_vnet_hdr(Object *obj, Error **errp)
716 {
717     CompareState *s = COLO_COMPARE(obj);
718 
719     return s->vnet_hdr;
720 }
721 
722 static void compare_set_vnet_hdr(Object *obj,
723                                  bool value,
724                                  Error **errp)
725 {
726     CompareState *s = COLO_COMPARE(obj);
727 
728     s->vnet_hdr = value;
729 }
730 
731 static void compare_pri_rs_finalize(SocketReadState *pri_rs)
732 {
733     CompareState *s = container_of(pri_rs, CompareState, pri_rs);
734     Connection *conn = NULL;
735 
736     if (packet_enqueue(s, PRIMARY_IN, &conn)) {
737         trace_colo_compare_main("primary: unsupported packet in");
738         compare_chr_send(s,
739                          pri_rs->buf,
740                          pri_rs->packet_len,
741                          pri_rs->vnet_hdr_len);
742     } else {
743         /* compare packet in the specified connection */
744         colo_compare_connection(conn, s);
745     }
746 }
747 
748 static void compare_sec_rs_finalize(SocketReadState *sec_rs)
749 {
750     CompareState *s = container_of(sec_rs, CompareState, sec_rs);
751     Connection *conn = NULL;
752 
753     if (packet_enqueue(s, SECONDARY_IN, &conn)) {
754         trace_colo_compare_main("secondary: unsupported packet in");
755     } else {
756         /* compare packet in the specified connection */
757         colo_compare_connection(conn, s);
758     }
759 }
760 
761 
762 /*
763  * Return 0 is success.
764  * Return 1 is failed.
765  */
766 static int find_and_check_chardev(Chardev **chr,
767                                   char *chr_name,
768                                   Error **errp)
769 {
770     *chr = qemu_chr_find(chr_name);
771     if (*chr == NULL) {
772         error_setg(errp, "Device '%s' not found",
773                    chr_name);
774         return 1;
775     }
776 
777     if (!qemu_chr_has_feature(*chr, QEMU_CHAR_FEATURE_RECONNECTABLE)) {
778         error_setg(errp, "chardev \"%s\" is not reconnectable",
779                    chr_name);
780         return 1;
781     }
782 
783     return 0;
784 }
785 
786 /*
787  * Called from the main thread on the primary
788  * to setup colo-compare.
789  */
790 static void colo_compare_complete(UserCreatable *uc, Error **errp)
791 {
792     CompareState *s = COLO_COMPARE(uc);
793     Chardev *chr;
794 
795     if (!s->pri_indev || !s->sec_indev || !s->outdev || !s->iothread) {
796         error_setg(errp, "colo compare needs 'primary_in' ,"
797                    "'secondary_in','outdev','iothread' property set");
798         return;
799     } else if (!strcmp(s->pri_indev, s->outdev) ||
800                !strcmp(s->sec_indev, s->outdev) ||
801                !strcmp(s->pri_indev, s->sec_indev)) {
802         error_setg(errp, "'indev' and 'outdev' could not be same "
803                    "for compare module");
804         return;
805     }
806 
807     if (find_and_check_chardev(&chr, s->pri_indev, errp) ||
808         !qemu_chr_fe_init(&s->chr_pri_in, chr, errp)) {
809         return;
810     }
811 
812     if (find_and_check_chardev(&chr, s->sec_indev, errp) ||
813         !qemu_chr_fe_init(&s->chr_sec_in, chr, errp)) {
814         return;
815     }
816 
817     if (find_and_check_chardev(&chr, s->outdev, errp) ||
818         !qemu_chr_fe_init(&s->chr_out, chr, errp)) {
819         return;
820     }
821 
822     net_socket_rs_init(&s->pri_rs, compare_pri_rs_finalize, s->vnet_hdr);
823     net_socket_rs_init(&s->sec_rs, compare_sec_rs_finalize, s->vnet_hdr);
824 
825     g_queue_init(&s->conn_list);
826 
827     s->connection_track_table = g_hash_table_new_full(connection_key_hash,
828                                                       connection_key_equal,
829                                                       g_free,
830                                                       connection_destroy);
831 
832     colo_compare_iothread(s);
833     return;
834 }
835 
836 static void colo_flush_packets(void *opaque, void *user_data)
837 {
838     CompareState *s = user_data;
839     Connection *conn = opaque;
840     Packet *pkt = NULL;
841 
842     while (!g_queue_is_empty(&conn->primary_list)) {
843         pkt = g_queue_pop_head(&conn->primary_list);
844         compare_chr_send(s,
845                          pkt->data,
846                          pkt->size,
847                          pkt->vnet_hdr_len);
848         packet_destroy(pkt, NULL);
849     }
850     while (!g_queue_is_empty(&conn->secondary_list)) {
851         pkt = g_queue_pop_head(&conn->secondary_list);
852         packet_destroy(pkt, NULL);
853     }
854 }
855 
856 static void colo_compare_class_init(ObjectClass *oc, void *data)
857 {
858     UserCreatableClass *ucc = USER_CREATABLE_CLASS(oc);
859 
860     ucc->complete = colo_compare_complete;
861 }
862 
863 static void colo_compare_init(Object *obj)
864 {
865     CompareState *s = COLO_COMPARE(obj);
866 
867     object_property_add_str(obj, "primary_in",
868                             compare_get_pri_indev, compare_set_pri_indev,
869                             NULL);
870     object_property_add_str(obj, "secondary_in",
871                             compare_get_sec_indev, compare_set_sec_indev,
872                             NULL);
873     object_property_add_str(obj, "outdev",
874                             compare_get_outdev, compare_set_outdev,
875                             NULL);
876     object_property_add_link(obj, "iothread", TYPE_IOTHREAD,
877                             (Object **)&s->iothread,
878                             object_property_allow_set_link,
879                             OBJ_PROP_LINK_UNREF_ON_RELEASE, NULL);
880 
881     s->vnet_hdr = false;
882     object_property_add_bool(obj, "vnet_hdr_support", compare_get_vnet_hdr,
883                              compare_set_vnet_hdr, NULL);
884 }
885 
886 static void colo_compare_finalize(Object *obj)
887 {
888     CompareState *s = COLO_COMPARE(obj);
889 
890     qemu_chr_fe_deinit(&s->chr_pri_in, false);
891     qemu_chr_fe_deinit(&s->chr_sec_in, false);
892     qemu_chr_fe_deinit(&s->chr_out, false);
893     if (s->iothread) {
894         colo_compare_timer_del(s);
895     }
896     /* Release all unhandled packets after compare thead exited */
897     g_queue_foreach(&s->conn_list, colo_flush_packets, s);
898 
899     g_queue_clear(&s->conn_list);
900 
901     if (s->connection_track_table) {
902         g_hash_table_destroy(s->connection_track_table);
903     }
904 
905     if (s->iothread) {
906         object_unref(OBJECT(s->iothread));
907     }
908     g_free(s->pri_indev);
909     g_free(s->sec_indev);
910     g_free(s->outdev);
911 }
912 
913 static const TypeInfo colo_compare_info = {
914     .name = TYPE_COLO_COMPARE,
915     .parent = TYPE_OBJECT,
916     .instance_size = sizeof(CompareState),
917     .instance_init = colo_compare_init,
918     .instance_finalize = colo_compare_finalize,
919     .class_size = sizeof(CompareClass),
920     .class_init = colo_compare_class_init,
921     .interfaces = (InterfaceInfo[]) {
922         { TYPE_USER_CREATABLE },
923         { }
924     }
925 };
926 
927 static void register_types(void)
928 {
929     type_register_static(&colo_compare_info);
930 }
931 
932 type_init(register_types);
933