xref: /openbmc/qemu/net/colo-compare.c (revision ab938ae4)
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 0 on success, if return -1 means the pkt
117  * is unsupported(arp and ipv6) and will be sent later
118  */
119 static int packet_enqueue(CompareState *s, int mode)
120 {
121     ConnectionKey key;
122     Packet *pkt = NULL;
123     Connection *conn;
124 
125     if (mode == PRIMARY_IN) {
126         pkt = packet_new(s->pri_rs.buf,
127                          s->pri_rs.packet_len,
128                          s->pri_rs.vnet_hdr_len);
129     } else {
130         pkt = packet_new(s->sec_rs.buf,
131                          s->sec_rs.packet_len,
132                          s->sec_rs.vnet_hdr_len);
133     }
134 
135     if (parse_packet_early(pkt)) {
136         packet_destroy(pkt, NULL);
137         pkt = NULL;
138         return -1;
139     }
140     fill_connection_key(pkt, &key);
141 
142     conn = connection_get(s->connection_track_table,
143                           &key,
144                           &s->conn_list);
145 
146     if (!conn->processing) {
147         g_queue_push_tail(&s->conn_list, conn);
148         conn->processing = true;
149     }
150 
151     if (mode == PRIMARY_IN) {
152         if (g_queue_get_length(&conn->primary_list) <=
153                                MAX_QUEUE_SIZE) {
154             g_queue_push_tail(&conn->primary_list, pkt);
155             if (conn->ip_proto == IPPROTO_TCP) {
156                 g_queue_sort(&conn->primary_list,
157                              (GCompareDataFunc)seq_sorter,
158                              NULL);
159             }
160         } else {
161             error_report("colo compare primary queue size too big,"
162                          "drop packet");
163         }
164     } else {
165         if (g_queue_get_length(&conn->secondary_list) <=
166                                MAX_QUEUE_SIZE) {
167             g_queue_push_tail(&conn->secondary_list, pkt);
168             if (conn->ip_proto == IPPROTO_TCP) {
169                 g_queue_sort(&conn->secondary_list,
170                              (GCompareDataFunc)seq_sorter,
171                              NULL);
172             }
173         } else {
174             error_report("colo compare secondary queue size too big,"
175                          "drop packet");
176         }
177     }
178 
179     return 0;
180 }
181 
182 /*
183  * The IP packets sent by primary and secondary
184  * will be compared in here
185  * TODO support ip fragment, Out-Of-Order
186  * return:    0  means packet same
187  *            > 0 || < 0 means packet different
188  */
189 static int colo_packet_compare_common(Packet *ppkt,
190                                       Packet *spkt,
191                                       int poffset,
192                                       int soffset)
193 {
194     if (trace_event_get_state_backends(TRACE_COLO_COMPARE_MISCOMPARE)) {
195         char pri_ip_src[20], pri_ip_dst[20], sec_ip_src[20], sec_ip_dst[20];
196 
197         strcpy(pri_ip_src, inet_ntoa(ppkt->ip->ip_src));
198         strcpy(pri_ip_dst, inet_ntoa(ppkt->ip->ip_dst));
199         strcpy(sec_ip_src, inet_ntoa(spkt->ip->ip_src));
200         strcpy(sec_ip_dst, inet_ntoa(spkt->ip->ip_dst));
201 
202         trace_colo_compare_ip_info(ppkt->size, pri_ip_src,
203                                    pri_ip_dst, spkt->size,
204                                    sec_ip_src, sec_ip_dst);
205     }
206 
207     poffset = ppkt->vnet_hdr_len + poffset;
208     soffset = ppkt->vnet_hdr_len + soffset;
209 
210     if (ppkt->size - poffset == spkt->size - soffset) {
211         return memcmp(ppkt->data + poffset,
212                       spkt->data + soffset,
213                       spkt->size - soffset);
214     } else {
215         trace_colo_compare_main("Net packet size are not the same");
216         return -1;
217     }
218 }
219 
220 /*
221  * Called from the compare thread on the primary
222  * for compare tcp packet
223  * compare_tcp copied from Dr. David Alan Gilbert's branch
224  */
225 static int colo_packet_compare_tcp(Packet *spkt, Packet *ppkt)
226 {
227     struct tcphdr *ptcp, *stcp;
228     int res;
229 
230     trace_colo_compare_main("compare tcp");
231 
232     ptcp = (struct tcphdr *)ppkt->transport_header;
233     stcp = (struct tcphdr *)spkt->transport_header;
234 
235     /*
236      * The 'identification' field in the IP header is *very* random
237      * it almost never matches.  Fudge this by ignoring differences in
238      * unfragmented packets; they'll normally sort themselves out if different
239      * anyway, and it should recover at the TCP level.
240      * An alternative would be to get both the primary and secondary to rewrite
241      * somehow; but that would need some sync traffic to sync the state
242      */
243     if (ntohs(ppkt->ip->ip_off) & IP_DF) {
244         spkt->ip->ip_id = ppkt->ip->ip_id;
245         /* and the sum will be different if the IDs were different */
246         spkt->ip->ip_sum = ppkt->ip->ip_sum;
247     }
248 
249     /*
250      * Check tcp header length for tcp option field.
251      * th_off > 5 means this tcp packet have options field.
252      * The tcp options maybe always different.
253      * for example:
254      * From RFC 7323.
255      * TCP Timestamps option (TSopt):
256      * Kind: 8
257      *
258      * Length: 10 bytes
259      *
260      *    +-------+-------+---------------------+---------------------+
261      *    |Kind=8 |  10   |   TS Value (TSval)  |TS Echo Reply (TSecr)|
262      *    +-------+-------+---------------------+---------------------+
263      *       1       1              4                     4
264      *
265      * In this case the primary guest's timestamp always different with
266      * the secondary guest's timestamp. COLO just focus on payload,
267      * so we just need skip this field.
268      */
269     if (ptcp->th_off > 5) {
270         ptrdiff_t ptcp_offset, stcp_offset;
271 
272         ptcp_offset = ppkt->transport_header - (uint8_t *)ppkt->data
273                       + (ptcp->th_off * 4) - ppkt->vnet_hdr_len;
274         stcp_offset = spkt->transport_header - (uint8_t *)spkt->data
275                       + (stcp->th_off * 4) - spkt->vnet_hdr_len;
276 
277         /*
278          * When network is busy, some tcp options(like sack) will unpredictable
279          * occur in primary side or secondary side. it will make packet size
280          * not same, but the two packet's payload is identical. colo just
281          * care about packet payload, so we skip the option field.
282          */
283         res = colo_packet_compare_common(ppkt, spkt, ptcp_offset, stcp_offset);
284     } else if (ptcp->th_sum == stcp->th_sum) {
285         res = colo_packet_compare_common(ppkt, spkt, ETH_HLEN, ETH_HLEN);
286     } else {
287         res = -1;
288     }
289 
290     if (res != 0 &&
291         trace_event_get_state_backends(TRACE_COLO_COMPARE_MISCOMPARE)) {
292         char pri_ip_src[20], pri_ip_dst[20], sec_ip_src[20], sec_ip_dst[20];
293 
294         strcpy(pri_ip_src, inet_ntoa(ppkt->ip->ip_src));
295         strcpy(pri_ip_dst, inet_ntoa(ppkt->ip->ip_dst));
296         strcpy(sec_ip_src, inet_ntoa(spkt->ip->ip_src));
297         strcpy(sec_ip_dst, inet_ntoa(spkt->ip->ip_dst));
298 
299         trace_colo_compare_ip_info(ppkt->size, pri_ip_src,
300                                    pri_ip_dst, spkt->size,
301                                    sec_ip_src, sec_ip_dst);
302 
303         trace_colo_compare_tcp_info("pri tcp packet",
304                                     ntohl(ptcp->th_seq),
305                                     ntohl(ptcp->th_ack),
306                                     res, ptcp->th_flags,
307                                     ppkt->size);
308 
309         trace_colo_compare_tcp_info("sec tcp packet",
310                                     ntohl(stcp->th_seq),
311                                     ntohl(stcp->th_ack),
312                                     res, stcp->th_flags,
313                                     spkt->size);
314 
315         qemu_hexdump((char *)ppkt->data, stderr,
316                      "colo-compare ppkt", ppkt->size);
317         qemu_hexdump((char *)spkt->data, stderr,
318                      "colo-compare spkt", spkt->size);
319     }
320 
321     return res;
322 }
323 
324 /*
325  * Called from the compare thread on the primary
326  * for compare udp packet
327  */
328 static int colo_packet_compare_udp(Packet *spkt, Packet *ppkt)
329 {
330     int ret;
331     int network_header_length = ppkt->ip->ip_hl * 4;
332 
333     trace_colo_compare_main("compare udp");
334 
335     /*
336      * Because of ppkt and spkt are both in the same connection,
337      * The ppkt's src ip, dst ip, src port, dst port, ip_proto all are
338      * same with spkt. In addition, IP header's Identification is a random
339      * field, we can handle it in IP fragmentation function later.
340      * COLO just concern the response net packet payload from primary guest
341      * and secondary guest are same or not, So we ignored all IP header include
342      * other field like TOS,TTL,IP Checksum. we only need to compare
343      * the ip payload here.
344      */
345     ret = colo_packet_compare_common(ppkt, spkt,
346                                      network_header_length + ETH_HLEN,
347                                      network_header_length + ETH_HLEN);
348 
349     if (ret) {
350         trace_colo_compare_udp_miscompare("primary pkt size", ppkt->size);
351         trace_colo_compare_udp_miscompare("Secondary pkt size", spkt->size);
352         if (trace_event_get_state_backends(TRACE_COLO_COMPARE_MISCOMPARE)) {
353             qemu_hexdump((char *)ppkt->data, stderr, "colo-compare pri pkt",
354                          ppkt->size);
355             qemu_hexdump((char *)spkt->data, stderr, "colo-compare sec pkt",
356                          spkt->size);
357         }
358     }
359 
360     return ret;
361 }
362 
363 /*
364  * Called from the compare thread on the primary
365  * for compare icmp packet
366  */
367 static int colo_packet_compare_icmp(Packet *spkt, Packet *ppkt)
368 {
369     int network_header_length = ppkt->ip->ip_hl * 4;
370 
371     trace_colo_compare_main("compare icmp");
372 
373     /*
374      * Because of ppkt and spkt are both in the same connection,
375      * The ppkt's src ip, dst ip, src port, dst port, ip_proto all are
376      * same with spkt. In addition, IP header's Identification is a random
377      * field, we can handle it in IP fragmentation function later.
378      * COLO just concern the response net packet payload from primary guest
379      * and secondary guest are same or not, So we ignored all IP header include
380      * other field like TOS,TTL,IP Checksum. we only need to compare
381      * the ip payload here.
382      */
383     if (colo_packet_compare_common(ppkt, spkt,
384                                    network_header_length + ETH_HLEN,
385                                    network_header_length + ETH_HLEN)) {
386         trace_colo_compare_icmp_miscompare("primary pkt size",
387                                            ppkt->size);
388         trace_colo_compare_icmp_miscompare("Secondary pkt size",
389                                            spkt->size);
390         if (trace_event_get_state_backends(TRACE_COLO_COMPARE_MISCOMPARE)) {
391             qemu_hexdump((char *)ppkt->data, stderr, "colo-compare pri pkt",
392                          ppkt->size);
393             qemu_hexdump((char *)spkt->data, stderr, "colo-compare sec pkt",
394                          spkt->size);
395         }
396         return -1;
397     } else {
398         return 0;
399     }
400 }
401 
402 /*
403  * Called from the compare thread on the primary
404  * for compare other packet
405  */
406 static int colo_packet_compare_other(Packet *spkt, Packet *ppkt)
407 {
408     trace_colo_compare_main("compare other");
409     if (trace_event_get_state_backends(TRACE_COLO_COMPARE_MISCOMPARE)) {
410         char pri_ip_src[20], pri_ip_dst[20], sec_ip_src[20], sec_ip_dst[20];
411 
412         strcpy(pri_ip_src, inet_ntoa(ppkt->ip->ip_src));
413         strcpy(pri_ip_dst, inet_ntoa(ppkt->ip->ip_dst));
414         strcpy(sec_ip_src, inet_ntoa(spkt->ip->ip_src));
415         strcpy(sec_ip_dst, inet_ntoa(spkt->ip->ip_dst));
416 
417         trace_colo_compare_ip_info(ppkt->size, pri_ip_src,
418                                    pri_ip_dst, spkt->size,
419                                    sec_ip_src, sec_ip_dst);
420     }
421 
422     return colo_packet_compare_common(ppkt, spkt, 0, 0);
423 }
424 
425 static int colo_old_packet_check_one(Packet *pkt, int64_t *check_time)
426 {
427     int64_t now = qemu_clock_get_ms(QEMU_CLOCK_HOST);
428 
429     if ((now - pkt->creation_ms) > (*check_time)) {
430         trace_colo_old_packet_check_found(pkt->creation_ms);
431         return 0;
432     } else {
433         return 1;
434     }
435 }
436 
437 static int colo_old_packet_check_one_conn(Connection *conn,
438                                           void *user_data)
439 {
440     GList *result = NULL;
441     int64_t check_time = REGULAR_PACKET_CHECK_MS;
442 
443     result = g_queue_find_custom(&conn->primary_list,
444                                  &check_time,
445                                  (GCompareFunc)colo_old_packet_check_one);
446 
447     if (result) {
448         /* Do checkpoint will flush old packet */
449         /*
450          * TODO: Notify colo frame to do checkpoint.
451          * colo_compare_inconsistent_notify();
452          */
453         return 0;
454     }
455 
456     return 1;
457 }
458 
459 /*
460  * Look for old packets that the secondary hasn't matched,
461  * if we have some then we have to checkpoint to wake
462  * the secondary up.
463  */
464 static void colo_old_packet_check(void *opaque)
465 {
466     CompareState *s = opaque;
467 
468     /*
469      * If we find one old packet, stop finding job and notify
470      * COLO frame do checkpoint.
471      */
472     g_queue_find_custom(&s->conn_list, NULL,
473                         (GCompareFunc)colo_old_packet_check_one_conn);
474 }
475 
476 /*
477  * Called from the compare thread on the primary
478  * for compare connection
479  */
480 static void colo_compare_connection(void *opaque, void *user_data)
481 {
482     CompareState *s = user_data;
483     Connection *conn = opaque;
484     Packet *pkt = NULL;
485     GList *result = NULL;
486     int ret;
487 
488     while (!g_queue_is_empty(&conn->primary_list) &&
489            !g_queue_is_empty(&conn->secondary_list)) {
490         pkt = g_queue_pop_head(&conn->primary_list);
491         switch (conn->ip_proto) {
492         case IPPROTO_TCP:
493             result = g_queue_find_custom(&conn->secondary_list,
494                      pkt, (GCompareFunc)colo_packet_compare_tcp);
495             break;
496         case IPPROTO_UDP:
497             result = g_queue_find_custom(&conn->secondary_list,
498                      pkt, (GCompareFunc)colo_packet_compare_udp);
499             break;
500         case IPPROTO_ICMP:
501             result = g_queue_find_custom(&conn->secondary_list,
502                      pkt, (GCompareFunc)colo_packet_compare_icmp);
503             break;
504         default:
505             result = g_queue_find_custom(&conn->secondary_list,
506                      pkt, (GCompareFunc)colo_packet_compare_other);
507             break;
508         }
509 
510         if (result) {
511             ret = compare_chr_send(s,
512                                    pkt->data,
513                                    pkt->size,
514                                    pkt->vnet_hdr_len);
515             if (ret < 0) {
516                 error_report("colo_send_primary_packet failed");
517             }
518             trace_colo_compare_main("packet same and release packet");
519             g_queue_remove(&conn->secondary_list, result->data);
520             packet_destroy(pkt, NULL);
521         } else {
522             /*
523              * If one packet arrive late, the secondary_list or
524              * primary_list will be empty, so we can't compare it
525              * until next comparison.
526              */
527             trace_colo_compare_main("packet different");
528             g_queue_push_head(&conn->primary_list, pkt);
529             /* TODO: colo_notify_checkpoint();*/
530             break;
531         }
532     }
533 }
534 
535 static int compare_chr_send(CompareState *s,
536                             const uint8_t *buf,
537                             uint32_t size,
538                             uint32_t vnet_hdr_len)
539 {
540     int ret = 0;
541     uint32_t len = htonl(size);
542 
543     if (!size) {
544         return 0;
545     }
546 
547     ret = qemu_chr_fe_write_all(&s->chr_out, (uint8_t *)&len, sizeof(len));
548     if (ret != sizeof(len)) {
549         goto err;
550     }
551 
552     if (s->vnet_hdr) {
553         /*
554          * We send vnet header len make other module(like filter-redirector)
555          * know how to parse net packet correctly.
556          */
557         len = htonl(vnet_hdr_len);
558         ret = qemu_chr_fe_write_all(&s->chr_out, (uint8_t *)&len, sizeof(len));
559         if (ret != sizeof(len)) {
560             goto err;
561         }
562     }
563 
564     ret = qemu_chr_fe_write_all(&s->chr_out, (uint8_t *)buf, size);
565     if (ret != size) {
566         goto err;
567     }
568 
569     return 0;
570 
571 err:
572     return ret < 0 ? ret : -EIO;
573 }
574 
575 static int compare_chr_can_read(void *opaque)
576 {
577     return COMPARE_READ_LEN_MAX;
578 }
579 
580 /*
581  * Called from the main thread on the primary for packets
582  * arriving over the socket from the primary.
583  */
584 static void compare_pri_chr_in(void *opaque, const uint8_t *buf, int size)
585 {
586     CompareState *s = COLO_COMPARE(opaque);
587     int ret;
588 
589     ret = net_fill_rstate(&s->pri_rs, buf, size);
590     if (ret == -1) {
591         qemu_chr_fe_set_handlers(&s->chr_pri_in, NULL, NULL, NULL, NULL,
592                                  NULL, NULL, true);
593         error_report("colo-compare primary_in error");
594     }
595 }
596 
597 /*
598  * Called from the main thread on the primary for packets
599  * arriving over the socket from the secondary.
600  */
601 static void compare_sec_chr_in(void *opaque, const uint8_t *buf, int size)
602 {
603     CompareState *s = COLO_COMPARE(opaque);
604     int ret;
605 
606     ret = net_fill_rstate(&s->sec_rs, buf, size);
607     if (ret == -1) {
608         qemu_chr_fe_set_handlers(&s->chr_sec_in, NULL, NULL, NULL, NULL,
609                                  NULL, NULL, true);
610         error_report("colo-compare secondary_in error");
611     }
612 }
613 
614 /*
615  * Check old packet regularly so it can watch for any packets
616  * that the secondary hasn't produced equivalents of.
617  */
618 static void check_old_packet_regular(void *opaque)
619 {
620     CompareState *s = opaque;
621 
622     /* if have old packet we will notify checkpoint */
623     colo_old_packet_check(s);
624     timer_mod(s->packet_check_timer, qemu_clock_get_ms(QEMU_CLOCK_VIRTUAL) +
625                 REGULAR_PACKET_CHECK_MS);
626 }
627 
628 static void colo_compare_timer_init(CompareState *s)
629 {
630     AioContext *ctx = iothread_get_aio_context(s->iothread);
631 
632     s->packet_check_timer = aio_timer_new(ctx, QEMU_CLOCK_VIRTUAL,
633                                 SCALE_MS, check_old_packet_regular,
634                                 s);
635     timer_mod(s->packet_check_timer, qemu_clock_get_ms(QEMU_CLOCK_VIRTUAL) +
636                     REGULAR_PACKET_CHECK_MS);
637 }
638 
639 static void colo_compare_timer_del(CompareState *s)
640 {
641     if (s->packet_check_timer) {
642         timer_del(s->packet_check_timer);
643         timer_free(s->packet_check_timer);
644         s->packet_check_timer = NULL;
645     }
646  }
647 
648 static void colo_compare_iothread(CompareState *s)
649 {
650     object_ref(OBJECT(s->iothread));
651     s->worker_context = iothread_get_g_main_context(s->iothread);
652 
653     qemu_chr_fe_set_handlers(&s->chr_pri_in, compare_chr_can_read,
654                              compare_pri_chr_in, NULL, NULL,
655                              s, s->worker_context, true);
656     qemu_chr_fe_set_handlers(&s->chr_sec_in, compare_chr_can_read,
657                              compare_sec_chr_in, NULL, NULL,
658                              s, s->worker_context, true);
659 
660     colo_compare_timer_init(s);
661 }
662 
663 static char *compare_get_pri_indev(Object *obj, Error **errp)
664 {
665     CompareState *s = COLO_COMPARE(obj);
666 
667     return g_strdup(s->pri_indev);
668 }
669 
670 static void compare_set_pri_indev(Object *obj, const char *value, Error **errp)
671 {
672     CompareState *s = COLO_COMPARE(obj);
673 
674     g_free(s->pri_indev);
675     s->pri_indev = g_strdup(value);
676 }
677 
678 static char *compare_get_sec_indev(Object *obj, Error **errp)
679 {
680     CompareState *s = COLO_COMPARE(obj);
681 
682     return g_strdup(s->sec_indev);
683 }
684 
685 static void compare_set_sec_indev(Object *obj, const char *value, Error **errp)
686 {
687     CompareState *s = COLO_COMPARE(obj);
688 
689     g_free(s->sec_indev);
690     s->sec_indev = g_strdup(value);
691 }
692 
693 static char *compare_get_outdev(Object *obj, Error **errp)
694 {
695     CompareState *s = COLO_COMPARE(obj);
696 
697     return g_strdup(s->outdev);
698 }
699 
700 static void compare_set_outdev(Object *obj, const char *value, Error **errp)
701 {
702     CompareState *s = COLO_COMPARE(obj);
703 
704     g_free(s->outdev);
705     s->outdev = g_strdup(value);
706 }
707 
708 static bool compare_get_vnet_hdr(Object *obj, Error **errp)
709 {
710     CompareState *s = COLO_COMPARE(obj);
711 
712     return s->vnet_hdr;
713 }
714 
715 static void compare_set_vnet_hdr(Object *obj,
716                                  bool value,
717                                  Error **errp)
718 {
719     CompareState *s = COLO_COMPARE(obj);
720 
721     s->vnet_hdr = value;
722 }
723 
724 static void compare_pri_rs_finalize(SocketReadState *pri_rs)
725 {
726     CompareState *s = container_of(pri_rs, CompareState, pri_rs);
727 
728     if (packet_enqueue(s, PRIMARY_IN)) {
729         trace_colo_compare_main("primary: unsupported packet in");
730         compare_chr_send(s,
731                          pri_rs->buf,
732                          pri_rs->packet_len,
733                          pri_rs->vnet_hdr_len);
734     } else {
735         /* compare connection */
736         g_queue_foreach(&s->conn_list, colo_compare_connection, s);
737     }
738 }
739 
740 static void compare_sec_rs_finalize(SocketReadState *sec_rs)
741 {
742     CompareState *s = container_of(sec_rs, CompareState, sec_rs);
743 
744     if (packet_enqueue(s, SECONDARY_IN)) {
745         trace_colo_compare_main("secondary: unsupported packet in");
746     } else {
747         /* compare connection */
748         g_queue_foreach(&s->conn_list, colo_compare_connection, s);
749     }
750 }
751 
752 
753 /*
754  * Return 0 is success.
755  * Return 1 is failed.
756  */
757 static int find_and_check_chardev(Chardev **chr,
758                                   char *chr_name,
759                                   Error **errp)
760 {
761     *chr = qemu_chr_find(chr_name);
762     if (*chr == NULL) {
763         error_setg(errp, "Device '%s' not found",
764                    chr_name);
765         return 1;
766     }
767 
768     if (!qemu_chr_has_feature(*chr, QEMU_CHAR_FEATURE_RECONNECTABLE)) {
769         error_setg(errp, "chardev \"%s\" is not reconnectable",
770                    chr_name);
771         return 1;
772     }
773 
774     return 0;
775 }
776 
777 /*
778  * Called from the main thread on the primary
779  * to setup colo-compare.
780  */
781 static void colo_compare_complete(UserCreatable *uc, Error **errp)
782 {
783     CompareState *s = COLO_COMPARE(uc);
784     Chardev *chr;
785 
786     if (!s->pri_indev || !s->sec_indev || !s->outdev || !s->iothread) {
787         error_setg(errp, "colo compare needs 'primary_in' ,"
788                    "'secondary_in','outdev','iothread' property set");
789         return;
790     } else if (!strcmp(s->pri_indev, s->outdev) ||
791                !strcmp(s->sec_indev, s->outdev) ||
792                !strcmp(s->pri_indev, s->sec_indev)) {
793         error_setg(errp, "'indev' and 'outdev' could not be same "
794                    "for compare module");
795         return;
796     }
797 
798     if (find_and_check_chardev(&chr, s->pri_indev, errp) ||
799         !qemu_chr_fe_init(&s->chr_pri_in, chr, errp)) {
800         return;
801     }
802 
803     if (find_and_check_chardev(&chr, s->sec_indev, errp) ||
804         !qemu_chr_fe_init(&s->chr_sec_in, chr, errp)) {
805         return;
806     }
807 
808     if (find_and_check_chardev(&chr, s->outdev, errp) ||
809         !qemu_chr_fe_init(&s->chr_out, chr, errp)) {
810         return;
811     }
812 
813     net_socket_rs_init(&s->pri_rs, compare_pri_rs_finalize, s->vnet_hdr);
814     net_socket_rs_init(&s->sec_rs, compare_sec_rs_finalize, s->vnet_hdr);
815 
816     g_queue_init(&s->conn_list);
817 
818     s->connection_track_table = g_hash_table_new_full(connection_key_hash,
819                                                       connection_key_equal,
820                                                       g_free,
821                                                       connection_destroy);
822 
823     colo_compare_iothread(s);
824     return;
825 }
826 
827 static void colo_flush_packets(void *opaque, void *user_data)
828 {
829     CompareState *s = user_data;
830     Connection *conn = opaque;
831     Packet *pkt = NULL;
832 
833     while (!g_queue_is_empty(&conn->primary_list)) {
834         pkt = g_queue_pop_head(&conn->primary_list);
835         compare_chr_send(s,
836                          pkt->data,
837                          pkt->size,
838                          pkt->vnet_hdr_len);
839         packet_destroy(pkt, NULL);
840     }
841     while (!g_queue_is_empty(&conn->secondary_list)) {
842         pkt = g_queue_pop_head(&conn->secondary_list);
843         packet_destroy(pkt, NULL);
844     }
845 }
846 
847 static void colo_compare_class_init(ObjectClass *oc, void *data)
848 {
849     UserCreatableClass *ucc = USER_CREATABLE_CLASS(oc);
850 
851     ucc->complete = colo_compare_complete;
852 }
853 
854 static void colo_compare_init(Object *obj)
855 {
856     CompareState *s = COLO_COMPARE(obj);
857 
858     object_property_add_str(obj, "primary_in",
859                             compare_get_pri_indev, compare_set_pri_indev,
860                             NULL);
861     object_property_add_str(obj, "secondary_in",
862                             compare_get_sec_indev, compare_set_sec_indev,
863                             NULL);
864     object_property_add_str(obj, "outdev",
865                             compare_get_outdev, compare_set_outdev,
866                             NULL);
867     object_property_add_link(obj, "iothread", TYPE_IOTHREAD,
868                             (Object **)&s->iothread,
869                             object_property_allow_set_link,
870                             OBJ_PROP_LINK_UNREF_ON_RELEASE, NULL);
871 
872     s->vnet_hdr = false;
873     object_property_add_bool(obj, "vnet_hdr_support", compare_get_vnet_hdr,
874                              compare_set_vnet_hdr, NULL);
875 }
876 
877 static void colo_compare_finalize(Object *obj)
878 {
879     CompareState *s = COLO_COMPARE(obj);
880 
881     qemu_chr_fe_deinit(&s->chr_pri_in, false);
882     qemu_chr_fe_deinit(&s->chr_sec_in, false);
883     qemu_chr_fe_deinit(&s->chr_out, false);
884     if (s->iothread) {
885         colo_compare_timer_del(s);
886     }
887     /* Release all unhandled packets after compare thead exited */
888     g_queue_foreach(&s->conn_list, colo_flush_packets, s);
889 
890     g_queue_clear(&s->conn_list);
891 
892     if (s->connection_track_table) {
893         g_hash_table_destroy(s->connection_track_table);
894     }
895 
896     if (s->iothread) {
897         object_unref(OBJECT(s->iothread));
898     }
899     g_free(s->pri_indev);
900     g_free(s->sec_indev);
901     g_free(s->outdev);
902 }
903 
904 static const TypeInfo colo_compare_info = {
905     .name = TYPE_COLO_COMPARE,
906     .parent = TYPE_OBJECT,
907     .instance_size = sizeof(CompareState),
908     .instance_init = colo_compare_init,
909     .instance_finalize = colo_compare_finalize,
910     .class_size = sizeof(CompareClass),
911     .class_init = colo_compare_class_init,
912     .interfaces = (InterfaceInfo[]) {
913         { TYPE_USER_CREATABLE },
914         { }
915     }
916 };
917 
918 static void register_types(void)
919 {
920     type_register_static(&colo_compare_info);
921 }
922 
923 type_init(register_types);
924