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