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         trace_colo_compare_udp_miscompare("Secondary pkt size", spkt->size);
 283         if (trace_event_get_state(TRACE_COLO_COMPARE_MISCOMPARE)) {
 284             qemu_hexdump((char *)ppkt->data, stderr, "colo-compare pri pkt",
 285                          ppkt->size);
 286             qemu_hexdump((char *)spkt->data, stderr, "colo-compare sec pkt",
 287                          spkt->size);
 288         }
 289     }
 290
 291     return ret;
 292 }
 293
 294 /*
 295  * Called from the compare thread on the primary
 296  * for compare icmp packet
 297  */
 298 static int colo_packet_compare_icmp(Packet *spkt, Packet *ppkt)
 299 {
 300     int network_header_length = ppkt->ip->ip_hl * 4;
 301
 302     trace_colo_compare_main("compare icmp");
 303
 304     /*
 305      * Because of ppkt and spkt are both in the same connection,
 306      * The ppkt's src ip, dst ip, src port, dst port, ip_proto all are
 307      * same with spkt. In addition, IP header's Identification is a random
 308      * field, we can handle it in IP fragmentation function later.
 309      * COLO just concern the response net packet payload from primary guest
 310      * and secondary guest are same or not, So we ignored all IP header include
 311      * other field like TOS,TTL,IP Checksum. we only need to compare
 312      * the ip payload here.
 313      */
 314     if (colo_packet_compare_common(ppkt, spkt,
 315                                    network_header_length + ETH_HLEN)) {
 316         trace_colo_compare_icmp_miscompare("primary pkt size",
 317                                            ppkt->size);
 318         trace_colo_compare_icmp_miscompare("Secondary pkt size",
 319                                            spkt->size);
 320         if (trace_event_get_state(TRACE_COLO_COMPARE_MISCOMPARE)) {
 321             qemu_hexdump((char *)ppkt->data, stderr, "colo-compare pri pkt",
 322                          ppkt->size);
 323             qemu_hexdump((char *)spkt->data, stderr, "colo-compare sec pkt",
 324                          spkt->size);
 325         }
 326         return -1;
 327     } else {
 328         return 0;
 329     }
 330 }
 331
 332 /*
 333  * Called from the compare thread on the primary
 334  * for compare other packet
 335  */
 336 static int colo_packet_compare_other(Packet *spkt, Packet *ppkt)
 337 {
 338     trace_colo_compare_main("compare other");
 339     trace_colo_compare_ip_info(ppkt->size, inet_ntoa(ppkt->ip->ip_src),
 340                                inet_ntoa(ppkt->ip->ip_dst), spkt->size,
 341                                inet_ntoa(spkt->ip->ip_src),
 342                                inet_ntoa(spkt->ip->ip_dst));
 343     return colo_packet_compare_common(ppkt, spkt, 0);
 344 }
 345
 346 static int colo_old_packet_check_one(Packet *pkt, int64_t *check_time)
 347 {
 348     int64_t now = qemu_clock_get_ms(QEMU_CLOCK_HOST);
 349
 350     if ((now - pkt->creation_ms) > (*check_time)) {
 351         trace_colo_old_packet_check_found(pkt->creation_ms);
 352         return 0;
 353     } else {
 354         return 1;
 355     }
 356 }
 357
 358 static void colo_old_packet_check_one_conn(void *opaque,
 359                                            void *user_data)
 360 {
 361     Connection *conn = opaque;
 362     GList *result = NULL;
 363     int64_t check_time = REGULAR_PACKET_CHECK_MS;
 364
 365     result = g_queue_find_custom(&conn->primary_list,
 366                                  &check_time,
 367                                  (GCompareFunc)colo_old_packet_check_one);
 368
 369     if (result) {
 370         /* do checkpoint will flush old packet */
 371         /* TODO: colo_notify_checkpoint();*/
 372     }
 373 }
 374
 375 /*
 376  * Look for old packets that the secondary hasn't matched,
 377  * if we have some then we have to checkpoint to wake
 378  * the secondary up.
 379  */
 380 static void colo_old_packet_check(void *opaque)
 381 {
 382     CompareState *s = opaque;
 383
 384     g_queue_foreach(&s->conn_list, colo_old_packet_check_one_conn, NULL);
 385 }
 386
 387 /*
 388  * Called from the compare thread on the primary
 389  * for compare connection
 390  */
 391 static void colo_compare_connection(void *opaque, void *user_data)
 392 {
 393     CompareState *s = user_data;
 394     Connection *conn = opaque;
 395     Packet *pkt = NULL;
 396     GList *result = NULL;
 397     int ret;
 398
 399     while (!g_queue_is_empty(&conn->primary_list) &&
 400            !g_queue_is_empty(&conn->secondary_list)) {
 401         pkt = g_queue_pop_tail(&conn->primary_list);
 402         switch (conn->ip_proto) {
 403         case IPPROTO_TCP:
 404             result = g_queue_find_custom(&conn->secondary_list,
 405                      pkt, (GCompareFunc)colo_packet_compare_tcp);
 406             break;
 407         case IPPROTO_UDP:
 408             result = g_queue_find_custom(&conn->secondary_list,
 409                      pkt, (GCompareFunc)colo_packet_compare_udp);
 410             break;
 411         case IPPROTO_ICMP:
 412             result = g_queue_find_custom(&conn->secondary_list,
 413                      pkt, (GCompareFunc)colo_packet_compare_icmp);
 414             break;
 415         default:
 416             result = g_queue_find_custom(&conn->secondary_list,
 417                      pkt, (GCompareFunc)colo_packet_compare_other);
 418             break;
 419         }
 420
 421         if (result) {
 422             ret = compare_chr_send(&s->chr_out, pkt->data, pkt->size);
 423             if (ret < 0) {
 424                 error_report("colo_send_primary_packet failed");
 425             }
 426             trace_colo_compare_main("packet same and release packet");
 427             g_queue_remove(&conn->secondary_list, result->data);
 428             packet_destroy(pkt, NULL);
 429         } else {
 430             /*
 431              * If one packet arrive late, the secondary_list or
 432              * primary_list will be empty, so we can't compare it
 433              * until next comparison.
 434              */
 435             trace_colo_compare_main("packet different");
 436             g_queue_push_tail(&conn->primary_list, pkt);
 437             /* TODO: colo_notify_checkpoint();*/
 438             break;
 439         }
 440     }
 441 }
 442
 443 static int compare_chr_send(CharBackend *out,
 444                             const uint8_t *buf,
 445                             uint32_t size)
 446 {
 447     int ret = 0;
 448     uint32_t len = htonl(size);
 449
 450     if (!size) {
 451         return 0;
 452     }
 453
 454     ret = qemu_chr_fe_write_all(out, (uint8_t *)&len, sizeof(len));
 455     if (ret != sizeof(len)) {
 456         goto err;
 457     }
 458
 459     ret = qemu_chr_fe_write_all(out, (uint8_t *)buf, size);
 460     if (ret != size) {
 461         goto err;
 462     }
 463
 464     return 0;
 465
 466 err:
 467     return ret < 0 ? ret : -EIO;
 468 }
 469
 470 static int compare_chr_can_read(void *opaque)
 471 {
 472     return COMPARE_READ_LEN_MAX;
 473 }
 474
 475 /*
 476  * Called from the main thread on the primary for packets
 477  * arriving over the socket from the primary.
 478  */
 479 static void compare_pri_chr_in(void *opaque, const uint8_t *buf, int size)
 480 {
 481     CompareState *s = COLO_COMPARE(opaque);
 482     int ret;
 483
 484     ret = net_fill_rstate(&s->pri_rs, buf, size);
 485     if (ret == -1) {
 486         qemu_chr_fe_set_handlers(&s->chr_pri_in, NULL, NULL, NULL,
 487                                  NULL, NULL, true);
 488         error_report("colo-compare primary_in error");
 489     }
 490 }
 491
 492 /*
 493  * Called from the main thread on the primary for packets
 494  * arriving over the socket from the secondary.
 495  */
 496 static void compare_sec_chr_in(void *opaque, const uint8_t *buf, int size)
 497 {
 498     CompareState *s = COLO_COMPARE(opaque);
 499     int ret;
 500
 501     ret = net_fill_rstate(&s->sec_rs, buf, size);
 502     if (ret == -1) {
 503         qemu_chr_fe_set_handlers(&s->chr_sec_in, NULL, NULL, NULL,
 504                                  NULL, NULL, true);
 505         error_report("colo-compare secondary_in error");
 506     }
 507 }
 508
 509 /*
 510  * Check old packet regularly so it can watch for any packets
 511  * that the secondary hasn't produced equivalents of.
 512  */
 513 static gboolean check_old_packet_regular(void *opaque)
 514 {
 515     CompareState *s = opaque;
 516
 517     /* if have old packet we will notify checkpoint */
 518     colo_old_packet_check(s);
 519
 520     return TRUE;
 521 }
 522
 523 static void *colo_compare_thread(void *opaque)
 524 {
 525     CompareState *s = opaque;
 526     GSource *timeout_source;
 527
 528     s->worker_context = g_main_context_new();
 529
 530     qemu_chr_fe_set_handlers(&s->chr_pri_in, compare_chr_can_read,
 531                           compare_pri_chr_in, NULL, s, s->worker_context, true);
 532     qemu_chr_fe_set_handlers(&s->chr_sec_in, compare_chr_can_read,
 533                           compare_sec_chr_in, NULL, s, s->worker_context, true);
 534
 535     s->compare_loop = g_main_loop_new(s->worker_context, FALSE);
 536
 537     /* To kick any packets that the secondary doesn't match */
 538     timeout_source = g_timeout_source_new(REGULAR_PACKET_CHECK_MS);
 539     g_source_set_callback(timeout_source,
 540                           (GSourceFunc)check_old_packet_regular, s, NULL);
 541     g_source_attach(timeout_source, s->worker_context);
 542
 543     g_main_loop_run(s->compare_loop);
 544
 545     g_source_unref(timeout_source);
 546     g_main_loop_unref(s->compare_loop);
 547     g_main_context_unref(s->worker_context);
 548     return NULL;
 549 }
 550
 551 static char *compare_get_pri_indev(Object *obj, Error **errp)
 552 {
 553     CompareState *s = COLO_COMPARE(obj);
 554
 555     return g_strdup(s->pri_indev);
 556 }
 557
 558 static void compare_set_pri_indev(Object *obj, const char *value, Error **errp)
 559 {
 560     CompareState *s = COLO_COMPARE(obj);
 561
 562     g_free(s->pri_indev);
 563     s->pri_indev = g_strdup(value);
 564 }
 565
 566 static char *compare_get_sec_indev(Object *obj, Error **errp)
 567 {
 568     CompareState *s = COLO_COMPARE(obj);
 569
 570     return g_strdup(s->sec_indev);
 571 }
 572
 573 static void compare_set_sec_indev(Object *obj, const char *value, Error **errp)
 574 {
 575     CompareState *s = COLO_COMPARE(obj);
 576
 577     g_free(s->sec_indev);
 578     s->sec_indev = g_strdup(value);
 579 }
 580
 581 static char *compare_get_outdev(Object *obj, Error **errp)
 582 {
 583     CompareState *s = COLO_COMPARE(obj);
 584
 585     return g_strdup(s->outdev);
 586 }
 587
 588 static void compare_set_outdev(Object *obj, const char *value, Error **errp)
 589 {
 590     CompareState *s = COLO_COMPARE(obj);
 591
 592     g_free(s->outdev);
 593     s->outdev = g_strdup(value);
 594 }
 595
 596 static void compare_pri_rs_finalize(SocketReadState *pri_rs)
 597 {
 598     CompareState *s = container_of(pri_rs, CompareState, pri_rs);
 599
 600     if (packet_enqueue(s, PRIMARY_IN)) {
 601         trace_colo_compare_main("primary: unsupported packet in");
 602         compare_chr_send(&s->chr_out, pri_rs->buf, pri_rs->packet_len);
 603     } else {
 604         /* compare connection */
 605         g_queue_foreach(&s->conn_list, colo_compare_connection, s);
 606     }
 607 }
 608
 609 static void compare_sec_rs_finalize(SocketReadState *sec_rs)
 610 {
 611     CompareState *s = container_of(sec_rs, CompareState, sec_rs);
 612
 613     if (packet_enqueue(s, SECONDARY_IN)) {
 614         trace_colo_compare_main("secondary: unsupported packet in");
 615     } else {
 616         /* compare connection */
 617         g_queue_foreach(&s->conn_list, colo_compare_connection, s);
 618     }
 619 }
 620
 621
 622 /*
 623  * Return 0 is success.
 624  * Return 1 is failed.
 625  */
 626 static int find_and_check_chardev(Chardev **chr,
 627                                   char *chr_name,
 628                                   Error **errp)
 629 {
 630     *chr = qemu_chr_find(chr_name);
 631     if (*chr == NULL) {
 632         error_setg(errp, "Device '%s' not found",
 633                    chr_name);
 634         return 1;
 635     }
 636
 637     if (!qemu_chr_has_feature(*chr, QEMU_CHAR_FEATURE_RECONNECTABLE)) {
 638         error_setg(errp, "chardev \"%s\" is not reconnectable",
 639                    chr_name);
 640         return 1;
 641     }
 642
 643     return 0;
 644 }
 645
 646 /*
 647  * Called from the main thread on the primary
 648  * to setup colo-compare.
 649  */
 650 static void colo_compare_complete(UserCreatable *uc, Error **errp)
 651 {
 652     CompareState *s = COLO_COMPARE(uc);
 653     Chardev *chr;
 654     char thread_name[64];
 655     static int compare_id;
 656
 657     if (!s->pri_indev || !s->sec_indev || !s->outdev) {
 658         error_setg(errp, "colo compare needs 'primary_in' ,"
 659                    "'secondary_in','outdev' property set");
 660         return;
 661     } else if (!strcmp(s->pri_indev, s->outdev) ||
 662                !strcmp(s->sec_indev, s->outdev) ||
 663                !strcmp(s->pri_indev, s->sec_indev)) {
 664         error_setg(errp, "'indev' and 'outdev' could not be same "
 665                    "for compare module");
 666         return;
 667     }
 668
 669     if (find_and_check_chardev(&chr, s->pri_indev, errp) ||
 670         !qemu_chr_fe_init(&s->chr_pri_in, chr, errp)) {
 671         return;
 672     }
 673
 674     if (find_and_check_chardev(&chr, s->sec_indev, errp) ||
 675         !qemu_chr_fe_init(&s->chr_sec_in, chr, errp)) {
 676         return;
 677     }
 678
 679     if (find_and_check_chardev(&chr, s->outdev, errp) ||
 680         !qemu_chr_fe_init(&s->chr_out, chr, errp)) {
 681         return;
 682     }
 683
 684     net_socket_rs_init(&s->pri_rs, compare_pri_rs_finalize);
 685     net_socket_rs_init(&s->sec_rs, compare_sec_rs_finalize);
 686
 687     g_queue_init(&s->conn_list);
 688
 689     s->connection_track_table = g_hash_table_new_full(connection_key_hash,
 690                                                       connection_key_equal,
 691                                                       g_free,
 692                                                       connection_destroy);
 693
 694     sprintf(thread_name, "colo-compare %d", compare_id);
 695     qemu_thread_create(&s->thread, thread_name,
 696                        colo_compare_thread, s,
 697                        QEMU_THREAD_JOINABLE);
 698     compare_id++;
 699
 700     return;
 701 }
 702
 703 static void colo_flush_packets(void *opaque, void *user_data)
 704 {
 705     CompareState *s = user_data;
 706     Connection *conn = opaque;
 707     Packet *pkt = NULL;
 708
 709     while (!g_queue_is_empty(&conn->primary_list)) {
 710         pkt = g_queue_pop_head(&conn->primary_list);
 711         compare_chr_send(&s->chr_out, pkt->data, pkt->size);
 712         packet_destroy(pkt, NULL);
 713     }
 714     while (!g_queue_is_empty(&conn->secondary_list)) {
 715         pkt = g_queue_pop_head(&conn->secondary_list);
 716         packet_destroy(pkt, NULL);
 717     }
 718 }
 719
 720 static void colo_compare_class_init(ObjectClass *oc, void *data)
 721 {
 722     UserCreatableClass *ucc = USER_CREATABLE_CLASS(oc);
 723
 724     ucc->complete = colo_compare_complete;
 725 }
 726
 727 static void colo_compare_init(Object *obj)
 728 {
 729     object_property_add_str(obj, "primary_in",
 730                             compare_get_pri_indev, compare_set_pri_indev,
 731                             NULL);
 732     object_property_add_str(obj, "secondary_in",
 733                             compare_get_sec_indev, compare_set_sec_indev,
 734                             NULL);
 735     object_property_add_str(obj, "outdev",
 736                             compare_get_outdev, compare_set_outdev,
 737                             NULL);
 738 }
 739
 740 static void colo_compare_finalize(Object *obj)
 741 {
 742     CompareState *s = COLO_COMPARE(obj);
 743
 744     qemu_chr_fe_set_handlers(&s->chr_pri_in, NULL, NULL, NULL, NULL,
 745                              s->worker_context, true);
 746     qemu_chr_fe_set_handlers(&s->chr_sec_in, NULL, NULL, NULL, NULL,
 747                              s->worker_context, true);
 748     qemu_chr_fe_deinit(&s->chr_out);
 749
 750     g_main_loop_quit(s->compare_loop);
 751     qemu_thread_join(&s->thread);
 752
 753     /* Release all unhandled packets after compare thead exited */
 754     g_queue_foreach(&s->conn_list, colo_flush_packets, s);
 755
 756     g_queue_clear(&s->conn_list);
 757
 758     g_hash_table_destroy(s->connection_track_table);
 759     g_free(s->pri_indev);
 760     g_free(s->sec_indev);
 761     g_free(s->outdev);
 762 }
 763
 764 static const TypeInfo colo_compare_info = {
 765     .name = TYPE_COLO_COMPARE,
 766     .parent = TYPE_OBJECT,
 767     .instance_size = sizeof(CompareState),
 768     .instance_init = colo_compare_init,
 769     .instance_finalize = colo_compare_finalize,
 770     .class_size = sizeof(CompareClass),
 771     .class_init = colo_compare_class_init,
 772     .interfaces = (InterfaceInfo[]) {
 773         { TYPE_USER_CREATABLE },
 774         { }
 775     }
 776 };
 777
 778 static void register_types(void)
 779 {
 780     type_register_static(&colo_compare_info);
 781 }
 782
 783 type_init(register_types);