xref: /openbmc/qemu/net/colo-compare.c (revision 9c489ea6)
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 
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     /* connection list: the connections belonged to this NIC could be found
79      * in this list.
80      * element type: Connection
81      */
82     GQueue conn_list;
83     /* hashtable to save connection */
84     GHashTable *connection_track_table;
85     /* compare thread, a thread for each NIC */
86     QemuThread thread;
87 
88     GMainContext *worker_context;
89     GMainLoop *compare_loop;
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, Packet *spkt, int offset)
190 {
191     if (trace_event_get_state(TRACE_COLO_COMPARE_MISCOMPARE)) {
192         char pri_ip_src[20], pri_ip_dst[20], sec_ip_src[20], sec_ip_dst[20];
193 
194         strcpy(pri_ip_src, inet_ntoa(ppkt->ip->ip_src));
195         strcpy(pri_ip_dst, inet_ntoa(ppkt->ip->ip_dst));
196         strcpy(sec_ip_src, inet_ntoa(spkt->ip->ip_src));
197         strcpy(sec_ip_dst, inet_ntoa(spkt->ip->ip_dst));
198 
199         trace_colo_compare_ip_info(ppkt->size, pri_ip_src,
200                                    pri_ip_dst, spkt->size,
201                                    sec_ip_src, sec_ip_dst);
202     }
203 
204     offset = ppkt->vnet_hdr_len + offset;
205 
206     if (ppkt->size == spkt->size) {
207         return memcmp(ppkt->data + offset,
208                       spkt->data + offset,
209                       spkt->size - offset);
210     } else {
211         trace_colo_compare_main("Net packet size are not the same");
212         return -1;
213     }
214 }
215 
216 /*
217  * Called from the compare thread on the primary
218  * for compare tcp packet
219  * compare_tcp copied from Dr. David Alan Gilbert's branch
220  */
221 static int colo_packet_compare_tcp(Packet *spkt, Packet *ppkt)
222 {
223     struct tcphdr *ptcp, *stcp;
224     int res;
225 
226     trace_colo_compare_main("compare tcp");
227 
228     ptcp = (struct tcphdr *)ppkt->transport_header;
229     stcp = (struct tcphdr *)spkt->transport_header;
230 
231     /*
232      * The 'identification' field in the IP header is *very* random
233      * it almost never matches.  Fudge this by ignoring differences in
234      * unfragmented packets; they'll normally sort themselves out if different
235      * anyway, and it should recover at the TCP level.
236      * An alternative would be to get both the primary and secondary to rewrite
237      * somehow; but that would need some sync traffic to sync the state
238      */
239     if (ntohs(ppkt->ip->ip_off) & IP_DF) {
240         spkt->ip->ip_id = ppkt->ip->ip_id;
241         /* and the sum will be different if the IDs were different */
242         spkt->ip->ip_sum = ppkt->ip->ip_sum;
243     }
244 
245     /*
246      * Check tcp header length for tcp option field.
247      * th_off > 5 means this tcp packet have options field.
248      * The tcp options maybe always different.
249      * for example:
250      * From RFC 7323.
251      * TCP Timestamps option (TSopt):
252      * Kind: 8
253      *
254      * Length: 10 bytes
255      *
256      *    +-------+-------+---------------------+---------------------+
257      *    |Kind=8 |  10   |   TS Value (TSval)  |TS Echo Reply (TSecr)|
258      *    +-------+-------+---------------------+---------------------+
259      *       1       1              4                     4
260      *
261      * In this case the primary guest's timestamp always different with
262      * the secondary guest's timestamp. COLO just focus on payload,
263      * so we just need skip this field.
264      */
265     if (ptcp->th_off > 5) {
266         ptrdiff_t tcp_offset;
267 
268         tcp_offset = ppkt->transport_header - (uint8_t *)ppkt->data
269                      + (ptcp->th_off * 4) - ppkt->vnet_hdr_len;
270         res = colo_packet_compare_common(ppkt, spkt, tcp_offset);
271     } else if (ptcp->th_sum == stcp->th_sum) {
272         res = colo_packet_compare_common(ppkt, spkt, ETH_HLEN);
273     } else {
274         res = -1;
275     }
276 
277     if (res != 0 && trace_event_get_state(TRACE_COLO_COMPARE_MISCOMPARE)) {
278         char pri_ip_src[20], pri_ip_dst[20], sec_ip_src[20], sec_ip_dst[20];
279 
280         strcpy(pri_ip_src, inet_ntoa(ppkt->ip->ip_src));
281         strcpy(pri_ip_dst, inet_ntoa(ppkt->ip->ip_dst));
282         strcpy(sec_ip_src, inet_ntoa(spkt->ip->ip_src));
283         strcpy(sec_ip_dst, inet_ntoa(spkt->ip->ip_dst));
284 
285         trace_colo_compare_ip_info(ppkt->size, pri_ip_src,
286                                    pri_ip_dst, spkt->size,
287                                    sec_ip_src, sec_ip_dst);
288 
289         trace_colo_compare_tcp_info("pri tcp packet",
290                                     ntohl(ptcp->th_seq),
291                                     ntohl(ptcp->th_ack),
292                                     res, ptcp->th_flags,
293                                     ppkt->size);
294 
295         trace_colo_compare_tcp_info("sec tcp packet",
296                                     ntohl(stcp->th_seq),
297                                     ntohl(stcp->th_ack),
298                                     res, stcp->th_flags,
299                                     spkt->size);
300 
301         qemu_hexdump((char *)ppkt->data, stderr,
302                      "colo-compare ppkt", ppkt->size);
303         qemu_hexdump((char *)spkt->data, stderr,
304                      "colo-compare spkt", spkt->size);
305     }
306 
307     return res;
308 }
309 
310 /*
311  * Called from the compare thread on the primary
312  * for compare udp packet
313  */
314 static int colo_packet_compare_udp(Packet *spkt, Packet *ppkt)
315 {
316     int ret;
317     int network_header_length = ppkt->ip->ip_hl * 4;
318 
319     trace_colo_compare_main("compare udp");
320 
321     /*
322      * Because of ppkt and spkt are both in the same connection,
323      * The ppkt's src ip, dst ip, src port, dst port, ip_proto all are
324      * same with spkt. In addition, IP header's Identification is a random
325      * field, we can handle it in IP fragmentation function later.
326      * COLO just concern the response net packet payload from primary guest
327      * and secondary guest are same or not, So we ignored all IP header include
328      * other field like TOS,TTL,IP Checksum. we only need to compare
329      * the ip payload here.
330      */
331     ret = colo_packet_compare_common(ppkt, spkt,
332                                      network_header_length + ETH_HLEN);
333 
334     if (ret) {
335         trace_colo_compare_udp_miscompare("primary pkt size", ppkt->size);
336         trace_colo_compare_udp_miscompare("Secondary pkt size", spkt->size);
337         if (trace_event_get_state(TRACE_COLO_COMPARE_MISCOMPARE)) {
338             qemu_hexdump((char *)ppkt->data, stderr, "colo-compare pri pkt",
339                          ppkt->size);
340             qemu_hexdump((char *)spkt->data, stderr, "colo-compare sec pkt",
341                          spkt->size);
342         }
343     }
344 
345     return ret;
346 }
347 
348 /*
349  * Called from the compare thread on the primary
350  * for compare icmp packet
351  */
352 static int colo_packet_compare_icmp(Packet *spkt, Packet *ppkt)
353 {
354     int network_header_length = ppkt->ip->ip_hl * 4;
355 
356     trace_colo_compare_main("compare icmp");
357 
358     /*
359      * Because of ppkt and spkt are both in the same connection,
360      * The ppkt's src ip, dst ip, src port, dst port, ip_proto all are
361      * same with spkt. In addition, IP header's Identification is a random
362      * field, we can handle it in IP fragmentation function later.
363      * COLO just concern the response net packet payload from primary guest
364      * and secondary guest are same or not, So we ignored all IP header include
365      * other field like TOS,TTL,IP Checksum. we only need to compare
366      * the ip payload here.
367      */
368     if (colo_packet_compare_common(ppkt, spkt,
369                                    network_header_length + ETH_HLEN)) {
370         trace_colo_compare_icmp_miscompare("primary pkt size",
371                                            ppkt->size);
372         trace_colo_compare_icmp_miscompare("Secondary pkt size",
373                                            spkt->size);
374         if (trace_event_get_state(TRACE_COLO_COMPARE_MISCOMPARE)) {
375             qemu_hexdump((char *)ppkt->data, stderr, "colo-compare pri pkt",
376                          ppkt->size);
377             qemu_hexdump((char *)spkt->data, stderr, "colo-compare sec pkt",
378                          spkt->size);
379         }
380         return -1;
381     } else {
382         return 0;
383     }
384 }
385 
386 /*
387  * Called from the compare thread on the primary
388  * for compare other packet
389  */
390 static int colo_packet_compare_other(Packet *spkt, Packet *ppkt)
391 {
392     trace_colo_compare_main("compare other");
393     if (trace_event_get_state(TRACE_COLO_COMPARE_MISCOMPARE)) {
394         char pri_ip_src[20], pri_ip_dst[20], sec_ip_src[20], sec_ip_dst[20];
395 
396         strcpy(pri_ip_src, inet_ntoa(ppkt->ip->ip_src));
397         strcpy(pri_ip_dst, inet_ntoa(ppkt->ip->ip_dst));
398         strcpy(sec_ip_src, inet_ntoa(spkt->ip->ip_src));
399         strcpy(sec_ip_dst, inet_ntoa(spkt->ip->ip_dst));
400 
401         trace_colo_compare_ip_info(ppkt->size, pri_ip_src,
402                                    pri_ip_dst, spkt->size,
403                                    sec_ip_src, sec_ip_dst);
404     }
405 
406     return colo_packet_compare_common(ppkt, spkt, 0);
407 }
408 
409 static int colo_old_packet_check_one(Packet *pkt, int64_t *check_time)
410 {
411     int64_t now = qemu_clock_get_ms(QEMU_CLOCK_HOST);
412 
413     if ((now - pkt->creation_ms) > (*check_time)) {
414         trace_colo_old_packet_check_found(pkt->creation_ms);
415         return 0;
416     } else {
417         return 1;
418     }
419 }
420 
421 static int colo_old_packet_check_one_conn(Connection *conn,
422                                           void *user_data)
423 {
424     GList *result = NULL;
425     int64_t check_time = REGULAR_PACKET_CHECK_MS;
426 
427     result = g_queue_find_custom(&conn->primary_list,
428                                  &check_time,
429                                  (GCompareFunc)colo_old_packet_check_one);
430 
431     if (result) {
432         /* do checkpoint will flush old packet */
433         /* TODO: colo_notify_checkpoint();*/
434         return 0;
435     }
436 
437     return 1;
438 }
439 
440 /*
441  * Look for old packets that the secondary hasn't matched,
442  * if we have some then we have to checkpoint to wake
443  * the secondary up.
444  */
445 static void colo_old_packet_check(void *opaque)
446 {
447     CompareState *s = opaque;
448 
449     /*
450      * If we find one old packet, stop finding job and notify
451      * COLO frame do checkpoint.
452      */
453     g_queue_find_custom(&s->conn_list, NULL,
454                         (GCompareFunc)colo_old_packet_check_one_conn);
455 }
456 
457 /*
458  * Called from the compare thread on the primary
459  * for compare connection
460  */
461 static void colo_compare_connection(void *opaque, void *user_data)
462 {
463     CompareState *s = user_data;
464     Connection *conn = opaque;
465     Packet *pkt = NULL;
466     GList *result = NULL;
467     int ret;
468 
469     while (!g_queue_is_empty(&conn->primary_list) &&
470            !g_queue_is_empty(&conn->secondary_list)) {
471         pkt = g_queue_pop_tail(&conn->primary_list);
472         switch (conn->ip_proto) {
473         case IPPROTO_TCP:
474             result = g_queue_find_custom(&conn->secondary_list,
475                      pkt, (GCompareFunc)colo_packet_compare_tcp);
476             break;
477         case IPPROTO_UDP:
478             result = g_queue_find_custom(&conn->secondary_list,
479                      pkt, (GCompareFunc)colo_packet_compare_udp);
480             break;
481         case IPPROTO_ICMP:
482             result = g_queue_find_custom(&conn->secondary_list,
483                      pkt, (GCompareFunc)colo_packet_compare_icmp);
484             break;
485         default:
486             result = g_queue_find_custom(&conn->secondary_list,
487                      pkt, (GCompareFunc)colo_packet_compare_other);
488             break;
489         }
490 
491         if (result) {
492             ret = compare_chr_send(s,
493                                    pkt->data,
494                                    pkt->size,
495                                    pkt->vnet_hdr_len);
496             if (ret < 0) {
497                 error_report("colo_send_primary_packet failed");
498             }
499             trace_colo_compare_main("packet same and release packet");
500             g_queue_remove(&conn->secondary_list, result->data);
501             packet_destroy(pkt, NULL);
502         } else {
503             /*
504              * If one packet arrive late, the secondary_list or
505              * primary_list will be empty, so we can't compare it
506              * until next comparison.
507              */
508             trace_colo_compare_main("packet different");
509             g_queue_push_tail(&conn->primary_list, pkt);
510             /* TODO: colo_notify_checkpoint();*/
511             break;
512         }
513     }
514 }
515 
516 static int compare_chr_send(CompareState *s,
517                             const uint8_t *buf,
518                             uint32_t size,
519                             uint32_t vnet_hdr_len)
520 {
521     int ret = 0;
522     uint32_t len = htonl(size);
523 
524     if (!size) {
525         return 0;
526     }
527 
528     ret = qemu_chr_fe_write_all(&s->chr_out, (uint8_t *)&len, sizeof(len));
529     if (ret != sizeof(len)) {
530         goto err;
531     }
532 
533     if (s->vnet_hdr) {
534         /*
535          * We send vnet header len make other module(like filter-redirector)
536          * know how to parse net packet correctly.
537          */
538         len = htonl(vnet_hdr_len);
539         ret = qemu_chr_fe_write_all(&s->chr_out, (uint8_t *)&len, sizeof(len));
540         if (ret != sizeof(len)) {
541             goto err;
542         }
543     }
544 
545     ret = qemu_chr_fe_write_all(&s->chr_out, (uint8_t *)buf, size);
546     if (ret != size) {
547         goto err;
548     }
549 
550     return 0;
551 
552 err:
553     return ret < 0 ? ret : -EIO;
554 }
555 
556 static int compare_chr_can_read(void *opaque)
557 {
558     return COMPARE_READ_LEN_MAX;
559 }
560 
561 /*
562  * Called from the main thread on the primary for packets
563  * arriving over the socket from the primary.
564  */
565 static void compare_pri_chr_in(void *opaque, const uint8_t *buf, int size)
566 {
567     CompareState *s = COLO_COMPARE(opaque);
568     int ret;
569 
570     ret = net_fill_rstate(&s->pri_rs, buf, size);
571     if (ret == -1) {
572         qemu_chr_fe_set_handlers(&s->chr_pri_in, NULL, NULL, NULL, NULL,
573                                  NULL, NULL, true);
574         error_report("colo-compare primary_in error");
575     }
576 }
577 
578 /*
579  * Called from the main thread on the primary for packets
580  * arriving over the socket from the secondary.
581  */
582 static void compare_sec_chr_in(void *opaque, const uint8_t *buf, int size)
583 {
584     CompareState *s = COLO_COMPARE(opaque);
585     int ret;
586 
587     ret = net_fill_rstate(&s->sec_rs, buf, size);
588     if (ret == -1) {
589         qemu_chr_fe_set_handlers(&s->chr_sec_in, NULL, NULL, NULL, NULL,
590                                  NULL, NULL, true);
591         error_report("colo-compare secondary_in error");
592     }
593 }
594 
595 /*
596  * Check old packet regularly so it can watch for any packets
597  * that the secondary hasn't produced equivalents of.
598  */
599 static gboolean check_old_packet_regular(void *opaque)
600 {
601     CompareState *s = opaque;
602 
603     /* if have old packet we will notify checkpoint */
604     colo_old_packet_check(s);
605 
606     return TRUE;
607 }
608 
609 static void *colo_compare_thread(void *opaque)
610 {
611     CompareState *s = opaque;
612     GSource *timeout_source;
613 
614     s->worker_context = g_main_context_new();
615 
616     qemu_chr_fe_set_handlers(&s->chr_pri_in, compare_chr_can_read,
617                              compare_pri_chr_in, NULL, NULL,
618                              s, s->worker_context, true);
619     qemu_chr_fe_set_handlers(&s->chr_sec_in, compare_chr_can_read,
620                              compare_sec_chr_in, NULL, NULL,
621                              s, s->worker_context, true);
622 
623     s->compare_loop = g_main_loop_new(s->worker_context, FALSE);
624 
625     /* To kick any packets that the secondary doesn't match */
626     timeout_source = g_timeout_source_new(REGULAR_PACKET_CHECK_MS);
627     g_source_set_callback(timeout_source,
628                           (GSourceFunc)check_old_packet_regular, s, NULL);
629     g_source_attach(timeout_source, s->worker_context);
630 
631     g_main_loop_run(s->compare_loop);
632 
633     g_source_unref(timeout_source);
634     g_main_loop_unref(s->compare_loop);
635     g_main_context_unref(s->worker_context);
636     return NULL;
637 }
638 
639 static char *compare_get_pri_indev(Object *obj, Error **errp)
640 {
641     CompareState *s = COLO_COMPARE(obj);
642 
643     return g_strdup(s->pri_indev);
644 }
645 
646 static void compare_set_pri_indev(Object *obj, const char *value, Error **errp)
647 {
648     CompareState *s = COLO_COMPARE(obj);
649 
650     g_free(s->pri_indev);
651     s->pri_indev = g_strdup(value);
652 }
653 
654 static char *compare_get_sec_indev(Object *obj, Error **errp)
655 {
656     CompareState *s = COLO_COMPARE(obj);
657 
658     return g_strdup(s->sec_indev);
659 }
660 
661 static void compare_set_sec_indev(Object *obj, const char *value, Error **errp)
662 {
663     CompareState *s = COLO_COMPARE(obj);
664 
665     g_free(s->sec_indev);
666     s->sec_indev = g_strdup(value);
667 }
668 
669 static char *compare_get_outdev(Object *obj, Error **errp)
670 {
671     CompareState *s = COLO_COMPARE(obj);
672 
673     return g_strdup(s->outdev);
674 }
675 
676 static void compare_set_outdev(Object *obj, const char *value, Error **errp)
677 {
678     CompareState *s = COLO_COMPARE(obj);
679 
680     g_free(s->outdev);
681     s->outdev = g_strdup(value);
682 }
683 
684 static bool compare_get_vnet_hdr(Object *obj, Error **errp)
685 {
686     CompareState *s = COLO_COMPARE(obj);
687 
688     return s->vnet_hdr;
689 }
690 
691 static void compare_set_vnet_hdr(Object *obj,
692                                  bool value,
693                                  Error **errp)
694 {
695     CompareState *s = COLO_COMPARE(obj);
696 
697     s->vnet_hdr = value;
698 }
699 
700 static void compare_pri_rs_finalize(SocketReadState *pri_rs)
701 {
702     CompareState *s = container_of(pri_rs, CompareState, pri_rs);
703 
704     if (packet_enqueue(s, PRIMARY_IN)) {
705         trace_colo_compare_main("primary: unsupported packet in");
706         compare_chr_send(s,
707                          pri_rs->buf,
708                          pri_rs->packet_len,
709                          pri_rs->vnet_hdr_len);
710     } else {
711         /* compare connection */
712         g_queue_foreach(&s->conn_list, colo_compare_connection, s);
713     }
714 }
715 
716 static void compare_sec_rs_finalize(SocketReadState *sec_rs)
717 {
718     CompareState *s = container_of(sec_rs, CompareState, sec_rs);
719 
720     if (packet_enqueue(s, SECONDARY_IN)) {
721         trace_colo_compare_main("secondary: unsupported packet in");
722     } else {
723         /* compare connection */
724         g_queue_foreach(&s->conn_list, colo_compare_connection, s);
725     }
726 }
727 
728 
729 /*
730  * Return 0 is success.
731  * Return 1 is failed.
732  */
733 static int find_and_check_chardev(Chardev **chr,
734                                   char *chr_name,
735                                   Error **errp)
736 {
737     *chr = qemu_chr_find(chr_name);
738     if (*chr == NULL) {
739         error_setg(errp, "Device '%s' not found",
740                    chr_name);
741         return 1;
742     }
743 
744     if (!qemu_chr_has_feature(*chr, QEMU_CHAR_FEATURE_RECONNECTABLE)) {
745         error_setg(errp, "chardev \"%s\" is not reconnectable",
746                    chr_name);
747         return 1;
748     }
749 
750     return 0;
751 }
752 
753 /*
754  * Called from the main thread on the primary
755  * to setup colo-compare.
756  */
757 static void colo_compare_complete(UserCreatable *uc, Error **errp)
758 {
759     CompareState *s = COLO_COMPARE(uc);
760     Chardev *chr;
761     char thread_name[64];
762     static int compare_id;
763 
764     if (!s->pri_indev || !s->sec_indev || !s->outdev) {
765         error_setg(errp, "colo compare needs 'primary_in' ,"
766                    "'secondary_in','outdev' property set");
767         return;
768     } else if (!strcmp(s->pri_indev, s->outdev) ||
769                !strcmp(s->sec_indev, s->outdev) ||
770                !strcmp(s->pri_indev, s->sec_indev)) {
771         error_setg(errp, "'indev' and 'outdev' could not be same "
772                    "for compare module");
773         return;
774     }
775 
776     if (find_and_check_chardev(&chr, s->pri_indev, errp) ||
777         !qemu_chr_fe_init(&s->chr_pri_in, chr, errp)) {
778         return;
779     }
780 
781     if (find_and_check_chardev(&chr, s->sec_indev, errp) ||
782         !qemu_chr_fe_init(&s->chr_sec_in, chr, errp)) {
783         return;
784     }
785 
786     if (find_and_check_chardev(&chr, s->outdev, errp) ||
787         !qemu_chr_fe_init(&s->chr_out, chr, errp)) {
788         return;
789     }
790 
791     net_socket_rs_init(&s->pri_rs, compare_pri_rs_finalize, s->vnet_hdr);
792     net_socket_rs_init(&s->sec_rs, compare_sec_rs_finalize, s->vnet_hdr);
793 
794     g_queue_init(&s->conn_list);
795 
796     s->connection_track_table = g_hash_table_new_full(connection_key_hash,
797                                                       connection_key_equal,
798                                                       g_free,
799                                                       connection_destroy);
800 
801     sprintf(thread_name, "colo-compare %d", compare_id);
802     qemu_thread_create(&s->thread, thread_name,
803                        colo_compare_thread, s,
804                        QEMU_THREAD_JOINABLE);
805     compare_id++;
806 
807     return;
808 }
809 
810 static void colo_flush_packets(void *opaque, void *user_data)
811 {
812     CompareState *s = user_data;
813     Connection *conn = opaque;
814     Packet *pkt = NULL;
815 
816     while (!g_queue_is_empty(&conn->primary_list)) {
817         pkt = g_queue_pop_head(&conn->primary_list);
818         compare_chr_send(s,
819                          pkt->data,
820                          pkt->size,
821                          pkt->vnet_hdr_len);
822         packet_destroy(pkt, NULL);
823     }
824     while (!g_queue_is_empty(&conn->secondary_list)) {
825         pkt = g_queue_pop_head(&conn->secondary_list);
826         packet_destroy(pkt, NULL);
827     }
828 }
829 
830 static void colo_compare_class_init(ObjectClass *oc, void *data)
831 {
832     UserCreatableClass *ucc = USER_CREATABLE_CLASS(oc);
833 
834     ucc->complete = colo_compare_complete;
835 }
836 
837 static void colo_compare_init(Object *obj)
838 {
839     CompareState *s = COLO_COMPARE(obj);
840 
841     object_property_add_str(obj, "primary_in",
842                             compare_get_pri_indev, compare_set_pri_indev,
843                             NULL);
844     object_property_add_str(obj, "secondary_in",
845                             compare_get_sec_indev, compare_set_sec_indev,
846                             NULL);
847     object_property_add_str(obj, "outdev",
848                             compare_get_outdev, compare_set_outdev,
849                             NULL);
850 
851     s->vnet_hdr = false;
852     object_property_add_bool(obj, "vnet_hdr_support", compare_get_vnet_hdr,
853                              compare_set_vnet_hdr, NULL);
854 }
855 
856 static void colo_compare_finalize(Object *obj)
857 {
858     CompareState *s = COLO_COMPARE(obj);
859 
860     qemu_chr_fe_deinit(&s->chr_pri_in, false);
861     qemu_chr_fe_deinit(&s->chr_sec_in, false);
862     qemu_chr_fe_deinit(&s->chr_out, false);
863 
864     g_main_loop_quit(s->compare_loop);
865     qemu_thread_join(&s->thread);
866 
867     /* Release all unhandled packets after compare thead exited */
868     g_queue_foreach(&s->conn_list, colo_flush_packets, s);
869 
870     g_queue_clear(&s->conn_list);
871 
872     g_hash_table_destroy(s->connection_track_table);
873     g_free(s->pri_indev);
874     g_free(s->sec_indev);
875     g_free(s->outdev);
876 }
877 
878 static const TypeInfo colo_compare_info = {
879     .name = TYPE_COLO_COMPARE,
880     .parent = TYPE_OBJECT,
881     .instance_size = sizeof(CompareState),
882     .instance_init = colo_compare_init,
883     .instance_finalize = colo_compare_finalize,
884     .class_size = sizeof(CompareClass),
885     .class_init = colo_compare_class_init,
886     .interfaces = (InterfaceInfo[]) {
887         { TYPE_USER_CREATABLE },
888         { }
889     }
890 };
891 
892 static void register_types(void)
893 {
894     type_register_static(&colo_compare_info);
895 }
896 
897 type_init(register_types);
898