net/colo-compare.c

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