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     if (trace_event_get_state(TRACE_COLO_COMPARE_MISCOMPARE)) {
 186         char pri_ip_src[20], pri_ip_dst[20], sec_ip_src[20], sec_ip_dst[20];
 187
 188         strcpy(pri_ip_src, inet_ntoa(ppkt->ip->ip_src));
 189         strcpy(pri_ip_dst, inet_ntoa(ppkt->ip->ip_dst));
 190         strcpy(sec_ip_src, inet_ntoa(spkt->ip->ip_src));
 191         strcpy(sec_ip_dst, inet_ntoa(spkt->ip->ip_dst));
 192
 193         trace_colo_compare_ip_info(ppkt->size, pri_ip_src,
 194                                    pri_ip_dst, spkt->size,
 195                                    sec_ip_src, sec_ip_dst);
 196     }
 197
 198     if (ppkt->size == spkt->size) {
 199         return memcmp(ppkt->data + offset, spkt->data + offset,
 200                       spkt->size - offset);
 201     } else {
 202         trace_colo_compare_main("Net packet size are not the same");
 203         return -1;
 204     }
 205 }
 206
 207 /*
 208  * Called from the compare thread on the primary
 209  * for compare tcp packet
 210  * compare_tcp copied from Dr. David Alan Gilbert's branch
 211  */
 212 static int colo_packet_compare_tcp(Packet *spkt, Packet *ppkt)
 213 {
 214     struct tcphdr *ptcp, *stcp;
 215     int res;
 216
 217     trace_colo_compare_main("compare tcp");
 218
 219     ptcp = (struct tcphdr *)ppkt->transport_header;
 220     stcp = (struct tcphdr *)spkt->transport_header;
 221
 222     /*
 223      * The 'identification' field in the IP header is *very* random
 224      * it almost never matches.  Fudge this by ignoring differences in
 225      * unfragmented packets; they'll normally sort themselves out if different
 226      * anyway, and it should recover at the TCP level.
 227      * An alternative would be to get both the primary and secondary to rewrite
 228      * somehow; but that would need some sync traffic to sync the state
 229      */
 230     if (ntohs(ppkt->ip->ip_off) & IP_DF) {
 231         spkt->ip->ip_id = ppkt->ip->ip_id;
 232         /* and the sum will be different if the IDs were different */
 233         spkt->ip->ip_sum = ppkt->ip->ip_sum;
 234     }
 235
 236     if (ptcp->th_sum == stcp->th_sum) {
 237         res = colo_packet_compare_common(ppkt, spkt, ETH_HLEN);
 238     } else {
 239         res = -1;
 240     }
 241
 242     if (res != 0 && trace_event_get_state(TRACE_COLO_COMPARE_MISCOMPARE)) {
 243         trace_colo_compare_pkt_info_src(inet_ntoa(ppkt->ip->ip_src),
 244                                         ntohl(stcp->th_seq),
 245                                         ntohl(stcp->th_ack),
 246                                         res, stcp->th_flags,
 247                                         spkt->size);
 248
 249         trace_colo_compare_pkt_info_dst(inet_ntoa(ppkt->ip->ip_dst),
 250                                         ntohl(ptcp->th_seq),
 251                                         ntohl(ptcp->th_ack),
 252                                         res, ptcp->th_flags,
 253                                         ppkt->size);
 254
 255         qemu_hexdump((char *)ppkt->data, stderr,
 256                      "colo-compare ppkt", ppkt->size);
 257         qemu_hexdump((char *)spkt->data, stderr,
 258                      "colo-compare spkt", spkt->size);
 259     }
 260
 261     return res;
 262 }
 263
 264 /*
 265  * Called from the compare thread on the primary
 266  * for compare udp packet
 267  */
 268 static int colo_packet_compare_udp(Packet *spkt, Packet *ppkt)
 269 {
 270     int ret;
 271     int network_header_length = ppkt->ip->ip_hl * 4;
 272
 273     trace_colo_compare_main("compare udp");
 274
 275     /*
 276      * Because of ppkt and spkt are both in the same connection,
 277      * The ppkt's src ip, dst ip, src port, dst port, ip_proto all are
 278      * same with spkt. In addition, IP header's Identification is a random
 279      * field, we can handle it in IP fragmentation function later.
 280      * COLO just concern the response net packet payload from primary guest
 281      * and secondary guest are same or not, So we ignored all IP header include
 282      * other field like TOS,TTL,IP Checksum. we only need to compare
 283      * the ip payload here.
 284      */
 285     ret = colo_packet_compare_common(ppkt, spkt,
 286                                      network_header_length + ETH_HLEN);
 287
 288     if (ret) {
 289         trace_colo_compare_udp_miscompare("primary pkt size", ppkt->size);
 290         trace_colo_compare_udp_miscompare("Secondary pkt size", spkt->size);
 291         if (trace_event_get_state(TRACE_COLO_COMPARE_MISCOMPARE)) {
 292             qemu_hexdump((char *)ppkt->data, stderr, "colo-compare pri pkt",
 293                          ppkt->size);
 294             qemu_hexdump((char *)spkt->data, stderr, "colo-compare sec pkt",
 295                          spkt->size);
 296         }
 297     }
 298
 299     return ret;
 300 }
 301
 302 /*
 303  * Called from the compare thread on the primary
 304  * for compare icmp packet
 305  */
 306 static int colo_packet_compare_icmp(Packet *spkt, Packet *ppkt)
 307 {
 308     int network_header_length = ppkt->ip->ip_hl * 4;
 309
 310     trace_colo_compare_main("compare icmp");
 311
 312     /*
 313      * Because of ppkt and spkt are both in the same connection,
 314      * The ppkt's src ip, dst ip, src port, dst port, ip_proto all are
 315      * same with spkt. In addition, IP header's Identification is a random
 316      * field, we can handle it in IP fragmentation function later.
 317      * COLO just concern the response net packet payload from primary guest
 318      * and secondary guest are same or not, So we ignored all IP header include
 319      * other field like TOS,TTL,IP Checksum. we only need to compare
 320      * the ip payload here.
 321      */
 322     if (colo_packet_compare_common(ppkt, spkt,
 323                                    network_header_length + ETH_HLEN)) {
 324         trace_colo_compare_icmp_miscompare("primary pkt size",
 325                                            ppkt->size);
 326         trace_colo_compare_icmp_miscompare("Secondary pkt size",
 327                                            spkt->size);
 328         if (trace_event_get_state(TRACE_COLO_COMPARE_MISCOMPARE)) {
 329             qemu_hexdump((char *)ppkt->data, stderr, "colo-compare pri pkt",
 330                          ppkt->size);
 331             qemu_hexdump((char *)spkt->data, stderr, "colo-compare sec pkt",
 332                          spkt->size);
 333         }
 334         return -1;
 335     } else {
 336         return 0;
 337     }
 338 }
 339
 340 /*
 341  * Called from the compare thread on the primary
 342  * for compare other packet
 343  */
 344 static int colo_packet_compare_other(Packet *spkt, Packet *ppkt)
 345 {
 346     trace_colo_compare_main("compare other");
 347     if (trace_event_get_state(TRACE_COLO_COMPARE_MISCOMPARE)) {
 348         char pri_ip_src[20], pri_ip_dst[20], sec_ip_src[20], sec_ip_dst[20];
 349
 350         strcpy(pri_ip_src, inet_ntoa(ppkt->ip->ip_src));
 351         strcpy(pri_ip_dst, inet_ntoa(ppkt->ip->ip_dst));
 352         strcpy(sec_ip_src, inet_ntoa(spkt->ip->ip_src));
 353         strcpy(sec_ip_dst, inet_ntoa(spkt->ip->ip_dst));
 354
 355         trace_colo_compare_ip_info(ppkt->size, pri_ip_src,
 356                                    pri_ip_dst, spkt->size,
 357                                    sec_ip_src, sec_ip_dst);
 358     }
 359
 360     return colo_packet_compare_common(ppkt, spkt, 0);
 361 }
 362
 363 static int colo_old_packet_check_one(Packet *pkt, int64_t *check_time)
 364 {
 365     int64_t now = qemu_clock_get_ms(QEMU_CLOCK_HOST);
 366
 367     if ((now - pkt->creation_ms) > (*check_time)) {
 368         trace_colo_old_packet_check_found(pkt->creation_ms);
 369         return 0;
 370     } else {
 371         return 1;
 372     }
 373 }
 374
 375 static void colo_old_packet_check_one_conn(void *opaque,
 376                                            void *user_data)
 377 {
 378     Connection *conn = opaque;
 379     GList *result = NULL;
 380     int64_t check_time = REGULAR_PACKET_CHECK_MS;
 381
 382     result = g_queue_find_custom(&conn->primary_list,
 383                                  &check_time,
 384                                  (GCompareFunc)colo_old_packet_check_one);
 385
 386     if (result) {
 387         /* do checkpoint will flush old packet */
 388         /* TODO: colo_notify_checkpoint();*/
 389     }
 390 }
 391
 392 /*
 393  * Look for old packets that the secondary hasn't matched,
 394  * if we have some then we have to checkpoint to wake
 395  * the secondary up.
 396  */
 397 static void colo_old_packet_check(void *opaque)
 398 {
 399     CompareState *s = opaque;
 400
 401     g_queue_foreach(&s->conn_list, colo_old_packet_check_one_conn, NULL);
 402 }
 403
 404 /*
 405  * Called from the compare thread on the primary
 406  * for compare connection
 407  */
 408 static void colo_compare_connection(void *opaque, void *user_data)
 409 {
 410     CompareState *s = user_data;
 411     Connection *conn = opaque;
 412     Packet *pkt = NULL;
 413     GList *result = NULL;
 414     int ret;
 415
 416     while (!g_queue_is_empty(&conn->primary_list) &&
 417            !g_queue_is_empty(&conn->secondary_list)) {
 418         pkt = g_queue_pop_tail(&conn->primary_list);
 419         switch (conn->ip_proto) {
 420         case IPPROTO_TCP:
 421             result = g_queue_find_custom(&conn->secondary_list,
 422                      pkt, (GCompareFunc)colo_packet_compare_tcp);
 423             break;
 424         case IPPROTO_UDP:
 425             result = g_queue_find_custom(&conn->secondary_list,
 426                      pkt, (GCompareFunc)colo_packet_compare_udp);
 427             break;
 428         case IPPROTO_ICMP:
 429             result = g_queue_find_custom(&conn->secondary_list,
 430                      pkt, (GCompareFunc)colo_packet_compare_icmp);
 431             break;
 432         default:
 433             result = g_queue_find_custom(&conn->secondary_list,
 434                      pkt, (GCompareFunc)colo_packet_compare_other);
 435             break;
 436         }
 437
 438         if (result) {
 439             ret = compare_chr_send(&s->chr_out, pkt->data, pkt->size);
 440             if (ret < 0) {
 441                 error_report("colo_send_primary_packet failed");
 442             }
 443             trace_colo_compare_main("packet same and release packet");
 444             g_queue_remove(&conn->secondary_list, result->data);
 445             packet_destroy(pkt, NULL);
 446         } else {
 447             /*
 448              * If one packet arrive late, the secondary_list or
 449              * primary_list will be empty, so we can't compare it
 450              * until next comparison.
 451              */
 452             trace_colo_compare_main("packet different");
 453             g_queue_push_tail(&conn->primary_list, pkt);
 454             /* TODO: colo_notify_checkpoint();*/
 455             break;
 456         }
 457     }
 458 }
 459
 460 static int compare_chr_send(CharBackend *out,
 461                             const uint8_t *buf,
 462                             uint32_t size)
 463 {
 464     int ret = 0;
 465     uint32_t len = htonl(size);
 466
 467     if (!size) {
 468         return 0;
 469     }
 470
 471     ret = qemu_chr_fe_write_all(out, (uint8_t *)&len, sizeof(len));
 472     if (ret != sizeof(len)) {
 473         goto err;
 474     }
 475
 476     ret = qemu_chr_fe_write_all(out, (uint8_t *)buf, size);
 477     if (ret != size) {
 478         goto err;
 479     }
 480
 481     return 0;
 482
 483 err:
 484     return ret < 0 ? ret : -EIO;
 485 }
 486
 487 static int compare_chr_can_read(void *opaque)
 488 {
 489     return COMPARE_READ_LEN_MAX;
 490 }
 491
 492 /*
 493  * Called from the main thread on the primary for packets
 494  * arriving over the socket from the primary.
 495  */
 496 static void compare_pri_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->pri_rs, buf, size);
 502     if (ret == -1) {
 503         qemu_chr_fe_set_handlers(&s->chr_pri_in, NULL, NULL, NULL,
 504                                  NULL, NULL, true);
 505         error_report("colo-compare primary_in error");
 506     }
 507 }
 508
 509 /*
 510  * Called from the main thread on the primary for packets
 511  * arriving over the socket from the secondary.
 512  */
 513 static void compare_sec_chr_in(void *opaque, const uint8_t *buf, int size)
 514 {
 515     CompareState *s = COLO_COMPARE(opaque);
 516     int ret;
 517
 518     ret = net_fill_rstate(&s->sec_rs, buf, size);
 519     if (ret == -1) {
 520         qemu_chr_fe_set_handlers(&s->chr_sec_in, NULL, NULL, NULL,
 521                                  NULL, NULL, true);
 522         error_report("colo-compare secondary_in error");
 523     }
 524 }
 525
 526 /*
 527  * Check old packet regularly so it can watch for any packets
 528  * that the secondary hasn't produced equivalents of.
 529  */
 530 static gboolean check_old_packet_regular(void *opaque)
 531 {
 532     CompareState *s = opaque;
 533
 534     /* if have old packet we will notify checkpoint */
 535     colo_old_packet_check(s);
 536
 537     return TRUE;
 538 }
 539
 540 static void *colo_compare_thread(void *opaque)
 541 {
 542     CompareState *s = opaque;
 543     GSource *timeout_source;
 544
 545     s->worker_context = g_main_context_new();
 546
 547     qemu_chr_fe_set_handlers(&s->chr_pri_in, compare_chr_can_read,
 548                           compare_pri_chr_in, NULL, s, s->worker_context, true);
 549     qemu_chr_fe_set_handlers(&s->chr_sec_in, compare_chr_can_read,
 550                           compare_sec_chr_in, NULL, s, s->worker_context, true);
 551
 552     s->compare_loop = g_main_loop_new(s->worker_context, FALSE);
 553
 554     /* To kick any packets that the secondary doesn't match */
 555     timeout_source = g_timeout_source_new(REGULAR_PACKET_CHECK_MS);
 556     g_source_set_callback(timeout_source,
 557                           (GSourceFunc)check_old_packet_regular, s, NULL);
 558     g_source_attach(timeout_source, s->worker_context);
 559
 560     g_main_loop_run(s->compare_loop);
 561
 562     g_source_unref(timeout_source);
 563     g_main_loop_unref(s->compare_loop);
 564     g_main_context_unref(s->worker_context);
 565     return NULL;
 566 }
 567
 568 static char *compare_get_pri_indev(Object *obj, Error **errp)
 569 {
 570     CompareState *s = COLO_COMPARE(obj);
 571
 572     return g_strdup(s->pri_indev);
 573 }
 574
 575 static void compare_set_pri_indev(Object *obj, const char *value, Error **errp)
 576 {
 577     CompareState *s = COLO_COMPARE(obj);
 578
 579     g_free(s->pri_indev);
 580     s->pri_indev = g_strdup(value);
 581 }
 582
 583 static char *compare_get_sec_indev(Object *obj, Error **errp)
 584 {
 585     CompareState *s = COLO_COMPARE(obj);
 586
 587     return g_strdup(s->sec_indev);
 588 }
 589
 590 static void compare_set_sec_indev(Object *obj, const char *value, Error **errp)
 591 {
 592     CompareState *s = COLO_COMPARE(obj);
 593
 594     g_free(s->sec_indev);
 595     s->sec_indev = g_strdup(value);
 596 }
 597
 598 static char *compare_get_outdev(Object *obj, Error **errp)
 599 {
 600     CompareState *s = COLO_COMPARE(obj);
 601
 602     return g_strdup(s->outdev);
 603 }
 604
 605 static void compare_set_outdev(Object *obj, const char *value, Error **errp)
 606 {
 607     CompareState *s = COLO_COMPARE(obj);
 608
 609     g_free(s->outdev);
 610     s->outdev = g_strdup(value);
 611 }
 612
 613 static void compare_pri_rs_finalize(SocketReadState *pri_rs)
 614 {
 615     CompareState *s = container_of(pri_rs, CompareState, pri_rs);
 616
 617     if (packet_enqueue(s, PRIMARY_IN)) {
 618         trace_colo_compare_main("primary: unsupported packet in");
 619         compare_chr_send(&s->chr_out, pri_rs->buf, pri_rs->packet_len);
 620     } else {
 621         /* compare connection */
 622         g_queue_foreach(&s->conn_list, colo_compare_connection, s);
 623     }
 624 }
 625
 626 static void compare_sec_rs_finalize(SocketReadState *sec_rs)
 627 {
 628     CompareState *s = container_of(sec_rs, CompareState, sec_rs);
 629
 630     if (packet_enqueue(s, SECONDARY_IN)) {
 631         trace_colo_compare_main("secondary: unsupported packet in");
 632     } else {
 633         /* compare connection */
 634         g_queue_foreach(&s->conn_list, colo_compare_connection, s);
 635     }
 636 }
 637
 638
 639 /*
 640  * Return 0 is success.
 641  * Return 1 is failed.
 642  */
 643 static int find_and_check_chardev(Chardev **chr,
 644                                   char *chr_name,
 645                                   Error **errp)
 646 {
 647     *chr = qemu_chr_find(chr_name);
 648     if (*chr == NULL) {
 649         error_setg(errp, "Device '%s' not found",
 650                    chr_name);
 651         return 1;
 652     }
 653
 654     if (!qemu_chr_has_feature(*chr, QEMU_CHAR_FEATURE_RECONNECTABLE)) {
 655         error_setg(errp, "chardev \"%s\" is not reconnectable",
 656                    chr_name);
 657         return 1;
 658     }
 659
 660     return 0;
 661 }
 662
 663 /*
 664  * Called from the main thread on the primary
 665  * to setup colo-compare.
 666  */
 667 static void colo_compare_complete(UserCreatable *uc, Error **errp)
 668 {
 669     CompareState *s = COLO_COMPARE(uc);
 670     Chardev *chr;
 671     char thread_name[64];
 672     static int compare_id;
 673
 674     if (!s->pri_indev || !s->sec_indev || !s->outdev) {
 675         error_setg(errp, "colo compare needs 'primary_in' ,"
 676                    "'secondary_in','outdev' property set");
 677         return;
 678     } else if (!strcmp(s->pri_indev, s->outdev) ||
 679                !strcmp(s->sec_indev, s->outdev) ||
 680                !strcmp(s->pri_indev, s->sec_indev)) {
 681         error_setg(errp, "'indev' and 'outdev' could not be same "
 682                    "for compare module");
 683         return;
 684     }
 685
 686     if (find_and_check_chardev(&chr, s->pri_indev, errp) ||
 687         !qemu_chr_fe_init(&s->chr_pri_in, chr, errp)) {
 688         return;
 689     }
 690
 691     if (find_and_check_chardev(&chr, s->sec_indev, errp) ||
 692         !qemu_chr_fe_init(&s->chr_sec_in, chr, errp)) {
 693         return;
 694     }
 695
 696     if (find_and_check_chardev(&chr, s->outdev, errp) ||
 697         !qemu_chr_fe_init(&s->chr_out, chr, errp)) {
 698         return;
 699     }
 700
 701     net_socket_rs_init(&s->pri_rs, compare_pri_rs_finalize);
 702     net_socket_rs_init(&s->sec_rs, compare_sec_rs_finalize);
 703
 704     g_queue_init(&s->conn_list);
 705
 706     s->connection_track_table = g_hash_table_new_full(connection_key_hash,
 707                                                       connection_key_equal,
 708                                                       g_free,
 709                                                       connection_destroy);
 710
 711     sprintf(thread_name, "colo-compare %d", compare_id);
 712     qemu_thread_create(&s->thread, thread_name,
 713                        colo_compare_thread, s,
 714                        QEMU_THREAD_JOINABLE);
 715     compare_id++;
 716
 717     return;
 718 }
 719
 720 static void colo_flush_packets(void *opaque, void *user_data)
 721 {
 722     CompareState *s = user_data;
 723     Connection *conn = opaque;
 724     Packet *pkt = NULL;
 725
 726     while (!g_queue_is_empty(&conn->primary_list)) {
 727         pkt = g_queue_pop_head(&conn->primary_list);
 728         compare_chr_send(&s->chr_out, pkt->data, pkt->size);
 729         packet_destroy(pkt, NULL);
 730     }
 731     while (!g_queue_is_empty(&conn->secondary_list)) {
 732         pkt = g_queue_pop_head(&conn->secondary_list);
 733         packet_destroy(pkt, NULL);
 734     }
 735 }
 736
 737 static void colo_compare_class_init(ObjectClass *oc, void *data)
 738 {
 739     UserCreatableClass *ucc = USER_CREATABLE_CLASS(oc);
 740
 741     ucc->complete = colo_compare_complete;
 742 }
 743
 744 static void colo_compare_init(Object *obj)
 745 {
 746     object_property_add_str(obj, "primary_in",
 747                             compare_get_pri_indev, compare_set_pri_indev,
 748                             NULL);
 749     object_property_add_str(obj, "secondary_in",
 750                             compare_get_sec_indev, compare_set_sec_indev,
 751                             NULL);
 752     object_property_add_str(obj, "outdev",
 753                             compare_get_outdev, compare_set_outdev,
 754                             NULL);
 755 }
 756
 757 static void colo_compare_finalize(Object *obj)
 758 {
 759     CompareState *s = COLO_COMPARE(obj);
 760
 761     qemu_chr_fe_set_handlers(&s->chr_pri_in, NULL, NULL, NULL, NULL,
 762                              s->worker_context, true);
 763     qemu_chr_fe_set_handlers(&s->chr_sec_in, NULL, NULL, NULL, NULL,
 764                              s->worker_context, true);
 765     qemu_chr_fe_deinit(&s->chr_out);
 766
 767     g_main_loop_quit(s->compare_loop);
 768     qemu_thread_join(&s->thread);
 769
 770     /* Release all unhandled packets after compare thead exited */
 771     g_queue_foreach(&s->conn_list, colo_flush_packets, s);
 772
 773     g_queue_clear(&s->conn_list);
 774
 775     g_hash_table_destroy(s->connection_track_table);
 776     g_free(s->pri_indev);
 777     g_free(s->sec_indev);
 778     g_free(s->outdev);
 779 }
 780
 781 static const TypeInfo colo_compare_info = {
 782     .name = TYPE_COLO_COMPARE,
 783     .parent = TYPE_OBJECT,
 784     .instance_size = sizeof(CompareState),
 785     .instance_init = colo_compare_init,
 786     .instance_finalize = colo_compare_finalize,
 787     .class_size = sizeof(CompareClass),
 788     .class_init = colo_compare_class_init,
 789     .interfaces = (InterfaceInfo[]) {
 790         { TYPE_USER_CREATABLE },
 791         { }
 792     }
 793 };
 794
 795 static void register_types(void)
 796 {
 797     type_register_static(&colo_compare_info);
 798 }
 799
 800 type_init(register_types);