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 <[email protected]>
  10  *
  11  * This work is licensed under the terms of the GNU GPL, version 2 or
  12  * later.  See the COPYING file in the top-level directory.
  13  */
  14
  15 #include "qemu/osdep.h"
  16 #include "qemu/error-report.h"
  17 #include "trace.h"
  18 #include "qemu-common.h"
  19 #include "qapi/qmp/qerror.h"
  20 #include "qapi/error.h"
  21 #include "net/net.h"
  22 #include "net/eth.h"
  23 #include "qom/object_interfaces.h"
  24 #include "qemu/iov.h"
  25 #include "qom/object.h"
  26 #include "qemu/typedefs.h"
  27 #include "net/queue.h"
  28 #include "chardev/char-fe.h"
  29 #include "qemu/sockets.h"
  30 #include "qapi-visit.h"
  31 #include "net/colo.h"
  32
  33 #define TYPE_COLO_COMPARE "colo-compare"
  34 #define COLO_COMPARE(obj) \
  35     OBJECT_CHECK(CompareState, (obj), TYPE_COLO_COMPARE)
  36
  37 #define COMPARE_READ_LEN_MAX NET_BUFSIZE
  38 #define MAX_QUEUE_SIZE 1024
  39
  40 /* TODO: Should be configurable */
  41 #define REGULAR_PACKET_CHECK_MS 3000
  42
  43 /*
  44   + CompareState ++
  45   |               |
  46   +---------------+   +---------------+         +---------------+
  47   |conn list      +--->conn           +--------->conn           |
  48   +---------------+   +---------------+         +---------------+
  49   |               |     |           |             |          |
  50   +---------------+ +---v----+  +---v----+    +---v----+ +---v----+
  51                     |primary |  |secondary    |primary | |secondary
  52                     |packet  |  |packet  +    |packet  | |packet  +
  53                     +--------+  +--------+    +--------+ +--------+
  54                         |           |             |          |
  55                     +---v----+  +---v----+    +---v----+ +---v----+
  56                     |primary |  |secondary    |primary | |secondary
  57                     |packet  |  |packet  +    |packet  | |packet  +
  58                     +--------+  +--------+    +--------+ +--------+
  59                         |           |             |          |
  60                     +---v----+  +---v----+    +---v----+ +---v----+
  61                     |primary |  |secondary    |primary | |secondary
  62                     |packet  |  |packet  +    |packet  | |packet  +
  63                     +--------+  +--------+    +--------+ +--------+
  64 */
  65 typedef struct CompareState {
  66     Object parent;
  67
  68     char *pri_indev;
  69     char *sec_indev;
  70     char *outdev;
  71     CharBackend chr_pri_in;
  72     CharBackend chr_sec_in;
  73     CharBackend chr_out;
  74     SocketReadState pri_rs;
  75     SocketReadState sec_rs;
  76
  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,
 125                          s->pri_rs.packet_len,
 126                          s->pri_rs.vnet_hdr_len);
 127     } else {
 128         pkt = packet_new(s->sec_rs.buf,
 129                          s->sec_rs.packet_len,
 130                          s->sec_rs.vnet_hdr_len);
 131     }
 132
 133     if (parse_packet_early(pkt)) {
 134         packet_destroy(pkt, NULL);
 135         pkt = NULL;
 136         return -1;
 137     }
 138     fill_connection_key(pkt, &key);
 139
 140     conn = connection_get(s->connection_track_table,
 141                           &key,
 142                           &s->conn_list);
 143
 144     if (!conn->processing) {
 145         g_queue_push_tail(&s->conn_list, conn);
 146         conn->processing = true;
 147     }
 148
 149     if (mode == PRIMARY_IN) {
 150         if (g_queue_get_length(&conn->primary_list) <=
 151                                MAX_QUEUE_SIZE) {
 152             g_queue_push_tail(&conn->primary_list, pkt);
 153             if (conn->ip_proto == IPPROTO_TCP) {
 154                 g_queue_sort(&conn->primary_list,
 155                              (GCompareDataFunc)seq_sorter,
 156                              NULL);
 157             }
 158         } else {
 159             error_report("colo compare primary queue size too big,"
 160                          "drop packet");
 161         }
 162     } else {
 163         if (g_queue_get_length(&conn->secondary_list) <=
 164                                MAX_QUEUE_SIZE) {
 165             g_queue_push_tail(&conn->secondary_list, pkt);
 166             if (conn->ip_proto == IPPROTO_TCP) {
 167                 g_queue_sort(&conn->secondary_list,
 168                              (GCompareDataFunc)seq_sorter,
 169                              NULL);
 170             }
 171         } else {
 172             error_report("colo compare secondary queue size too big,"
 173                          "drop packet");
 174         }
 175     }
 176
 177     return 0;
 178 }
 179
 180 /*
 181  * The IP packets sent by primary and secondary
 182  * will be compared in here
 183  * TODO support ip fragment, Out-Of-Order
 184  * return:    0  means packet same
 185  *            > 0 || < 0 means packet different
 186  */
 187 static int colo_packet_compare_common(Packet *ppkt, Packet *spkt, int offset)
 188 {
 189     if (trace_event_get_state(TRACE_COLO_COMPARE_MISCOMPARE)) {
 190         char pri_ip_src[20], pri_ip_dst[20], sec_ip_src[20], sec_ip_dst[20];
 191
 192         strcpy(pri_ip_src, inet_ntoa(ppkt->ip->ip_src));
 193         strcpy(pri_ip_dst, inet_ntoa(ppkt->ip->ip_dst));
 194         strcpy(sec_ip_src, inet_ntoa(spkt->ip->ip_src));
 195         strcpy(sec_ip_dst, inet_ntoa(spkt->ip->ip_dst));
 196
 197         trace_colo_compare_ip_info(ppkt->size, pri_ip_src,
 198                                    pri_ip_dst, spkt->size,
 199                                    sec_ip_src, sec_ip_dst);
 200     }
 201
 202     if (ppkt->size == spkt->size) {
 203         return memcmp(ppkt->data + offset, spkt->data + offset,
 204                       spkt->size - offset);
 205     } else {
 206         trace_colo_compare_main("Net packet size are not the same");
 207         return -1;
 208     }
 209 }
 210
 211 /*
 212  * Called from the compare thread on the primary
 213  * for compare tcp packet
 214  * compare_tcp copied from Dr. David Alan Gilbert's branch
 215  */
 216 static int colo_packet_compare_tcp(Packet *spkt, Packet *ppkt)
 217 {
 218     struct tcphdr *ptcp, *stcp;
 219     int res;
 220
 221     trace_colo_compare_main("compare tcp");
 222
 223     ptcp = (struct tcphdr *)ppkt->transport_header;
 224     stcp = (struct tcphdr *)spkt->transport_header;
 225
 226     /*
 227      * The 'identification' field in the IP header is *very* random
 228      * it almost never matches.  Fudge this by ignoring differences in
 229      * unfragmented packets; they'll normally sort themselves out if different
 230      * anyway, and it should recover at the TCP level.
 231      * An alternative would be to get both the primary and secondary to rewrite
 232      * somehow; but that would need some sync traffic to sync the state
 233      */
 234     if (ntohs(ppkt->ip->ip_off) & IP_DF) {
 235         spkt->ip->ip_id = ppkt->ip->ip_id;
 236         /* and the sum will be different if the IDs were different */
 237         spkt->ip->ip_sum = ppkt->ip->ip_sum;
 238     }
 239
 240     /*
 241      * Check tcp header length for tcp option field.
 242      * th_off > 5 means this tcp packet have options field.
 243      * The tcp options maybe always different.
 244      * for example:
 245      * From RFC 7323.
 246      * TCP Timestamps option (TSopt):
 247      * Kind: 8
 248      *
 249      * Length: 10 bytes
 250      *
 251      *    +-------+-------+---------------------+---------------------+
 252      *    |Kind=8 |  10   |   TS Value (TSval)  |TS Echo Reply (TSecr)|
 253      *    +-------+-------+---------------------+---------------------+
 254      *       1       1              4                     4
 255      *
 256      * In this case the primary guest's timestamp always different with
 257      * the secondary guest's timestamp. COLO just focus on payload,
 258      * so we just need skip this field.
 259      */
 260     if (ptcp->th_off > 5) {
 261         ptrdiff_t tcp_offset;
 262         tcp_offset = ppkt->transport_header - (uint8_t *)ppkt->data
 263                      + (ptcp->th_off * 4);
 264         res = colo_packet_compare_common(ppkt, spkt, tcp_offset);
 265     } else if (ptcp->th_sum == stcp->th_sum) {
 266         res = colo_packet_compare_common(ppkt, spkt, ETH_HLEN);
 267     } else {
 268         res = -1;
 269     }
 270
 271     if (res != 0 && trace_event_get_state(TRACE_COLO_COMPARE_MISCOMPARE)) {
 272         char pri_ip_src[20], pri_ip_dst[20], sec_ip_src[20], sec_ip_dst[20];
 273
 274         strcpy(pri_ip_src, inet_ntoa(ppkt->ip->ip_src));
 275         strcpy(pri_ip_dst, inet_ntoa(ppkt->ip->ip_dst));
 276         strcpy(sec_ip_src, inet_ntoa(spkt->ip->ip_src));
 277         strcpy(sec_ip_dst, inet_ntoa(spkt->ip->ip_dst));
 278
 279         trace_colo_compare_ip_info(ppkt->size, pri_ip_src,
 280                                    pri_ip_dst, spkt->size,
 281                                    sec_ip_src, sec_ip_dst);
 282
 283         trace_colo_compare_tcp_info("pri tcp packet",
 284                                     ntohl(ptcp->th_seq),
 285                                     ntohl(ptcp->th_ack),
 286                                     res, ptcp->th_flags,
 287                                     ppkt->size);
 288
 289         trace_colo_compare_tcp_info("sec tcp packet",
 290                                     ntohl(stcp->th_seq),
 291                                     ntohl(stcp->th_ack),
 292                                     res, stcp->th_flags,
 293                                     spkt->size);
 294
 295         qemu_hexdump((char *)ppkt->data, stderr,
 296                      "colo-compare ppkt", ppkt->size);
 297         qemu_hexdump((char *)spkt->data, stderr,
 298                      "colo-compare spkt", spkt->size);
 299     }
 300
 301     return res;
 302 }
 303
 304 /*
 305  * Called from the compare thread on the primary
 306  * for compare udp packet
 307  */
 308 static int colo_packet_compare_udp(Packet *spkt, Packet *ppkt)
 309 {
 310     int ret;
 311     int network_header_length = ppkt->ip->ip_hl * 4;
 312
 313     trace_colo_compare_main("compare udp");
 314
 315     /*
 316      * Because of ppkt and spkt are both in the same connection,
 317      * The ppkt's src ip, dst ip, src port, dst port, ip_proto all are
 318      * same with spkt. In addition, IP header's Identification is a random
 319      * field, we can handle it in IP fragmentation function later.
 320      * COLO just concern the response net packet payload from primary guest
 321      * and secondary guest are same or not, So we ignored all IP header include
 322      * other field like TOS,TTL,IP Checksum. we only need to compare
 323      * the ip payload here.
 324      */
 325     ret = colo_packet_compare_common(ppkt, spkt,
 326                                      network_header_length + ETH_HLEN);
 327
 328     if (ret) {
 329         trace_colo_compare_udp_miscompare("primary pkt size", ppkt->size);
 330         trace_colo_compare_udp_miscompare("Secondary pkt size", spkt->size);
 331         if (trace_event_get_state(TRACE_COLO_COMPARE_MISCOMPARE)) {
 332             qemu_hexdump((char *)ppkt->data, stderr, "colo-compare pri pkt",
 333                          ppkt->size);
 334             qemu_hexdump((char *)spkt->data, stderr, "colo-compare sec pkt",
 335                          spkt->size);
 336         }
 337     }
 338
 339     return ret;
 340 }
 341
 342 /*
 343  * Called from the compare thread on the primary
 344  * for compare icmp packet
 345  */
 346 static int colo_packet_compare_icmp(Packet *spkt, Packet *ppkt)
 347 {
 348     int network_header_length = ppkt->ip->ip_hl * 4;
 349
 350     trace_colo_compare_main("compare icmp");
 351
 352     /*
 353      * Because of ppkt and spkt are both in the same connection,
 354      * The ppkt's src ip, dst ip, src port, dst port, ip_proto all are
 355      * same with spkt. In addition, IP header's Identification is a random
 356      * field, we can handle it in IP fragmentation function later.
 357      * COLO just concern the response net packet payload from primary guest
 358      * and secondary guest are same or not, So we ignored all IP header include
 359      * other field like TOS,TTL,IP Checksum. we only need to compare
 360      * the ip payload here.
 361      */
 362     if (colo_packet_compare_common(ppkt, spkt,
 363                                    network_header_length + ETH_HLEN)) {
 364         trace_colo_compare_icmp_miscompare("primary pkt size",
 365                                            ppkt->size);
 366         trace_colo_compare_icmp_miscompare("Secondary pkt size",
 367                                            spkt->size);
 368         if (trace_event_get_state(TRACE_COLO_COMPARE_MISCOMPARE)) {
 369             qemu_hexdump((char *)ppkt->data, stderr, "colo-compare pri pkt",
 370                          ppkt->size);
 371             qemu_hexdump((char *)spkt->data, stderr, "colo-compare sec pkt",
 372                          spkt->size);
 373         }
 374         return -1;
 375     } else {
 376         return 0;
 377     }
 378 }
 379
 380 /*
 381  * Called from the compare thread on the primary
 382  * for compare other packet
 383  */
 384 static int colo_packet_compare_other(Packet *spkt, Packet *ppkt)
 385 {
 386     trace_colo_compare_main("compare other");
 387     if (trace_event_get_state(TRACE_COLO_COMPARE_MISCOMPARE)) {
 388         char pri_ip_src[20], pri_ip_dst[20], sec_ip_src[20], sec_ip_dst[20];
 389
 390         strcpy(pri_ip_src, inet_ntoa(ppkt->ip->ip_src));
 391         strcpy(pri_ip_dst, inet_ntoa(ppkt->ip->ip_dst));
 392         strcpy(sec_ip_src, inet_ntoa(spkt->ip->ip_src));
 393         strcpy(sec_ip_dst, inet_ntoa(spkt->ip->ip_dst));
 394
 395         trace_colo_compare_ip_info(ppkt->size, pri_ip_src,
 396                                    pri_ip_dst, spkt->size,
 397                                    sec_ip_src, sec_ip_dst);
 398     }
 399
 400     return colo_packet_compare_common(ppkt, spkt, 0);
 401 }
 402
 403 static int colo_old_packet_check_one(Packet *pkt, int64_t *check_time)
 404 {
 405     int64_t now = qemu_clock_get_ms(QEMU_CLOCK_HOST);
 406
 407     if ((now - pkt->creation_ms) > (*check_time)) {
 408         trace_colo_old_packet_check_found(pkt->creation_ms);
 409         return 0;
 410     } else {
 411         return 1;
 412     }
 413 }
 414
 415 static int colo_old_packet_check_one_conn(Connection *conn,
 416                                           void *user_data)
 417 {
 418     GList *result = NULL;
 419     int64_t check_time = REGULAR_PACKET_CHECK_MS;
 420
 421     result = g_queue_find_custom(&conn->primary_list,
 422                                  &check_time,
 423                                  (GCompareFunc)colo_old_packet_check_one);
 424
 425     if (result) {
 426         /* do checkpoint will flush old packet */
 427         /* TODO: colo_notify_checkpoint();*/
 428         return 0;
 429     }
 430
 431     return 1;
 432 }
 433
 434 /*
 435  * Look for old packets that the secondary hasn't matched,
 436  * if we have some then we have to checkpoint to wake
 437  * the secondary up.
 438  */
 439 static void colo_old_packet_check(void *opaque)
 440 {
 441     CompareState *s = opaque;
 442
 443     /*
 444      * If we find one old packet, stop finding job and notify
 445      * COLO frame do checkpoint.
 446      */
 447     g_queue_find_custom(&s->conn_list, NULL,
 448                         (GCompareFunc)colo_old_packet_check_one_conn);
 449 }
 450
 451 /*
 452  * Called from the compare thread on the primary
 453  * for compare connection
 454  */
 455 static void colo_compare_connection(void *opaque, void *user_data)
 456 {
 457     CompareState *s = user_data;
 458     Connection *conn = opaque;
 459     Packet *pkt = NULL;
 460     GList *result = NULL;
 461     int ret;
 462
 463     while (!g_queue_is_empty(&conn->primary_list) &&
 464            !g_queue_is_empty(&conn->secondary_list)) {
 465         pkt = g_queue_pop_tail(&conn->primary_list);
 466         switch (conn->ip_proto) {
 467         case IPPROTO_TCP:
 468             result = g_queue_find_custom(&conn->secondary_list,
 469                      pkt, (GCompareFunc)colo_packet_compare_tcp);
 470             break;
 471         case IPPROTO_UDP:
 472             result = g_queue_find_custom(&conn->secondary_list,
 473                      pkt, (GCompareFunc)colo_packet_compare_udp);
 474             break;
 475         case IPPROTO_ICMP:
 476             result = g_queue_find_custom(&conn->secondary_list,
 477                      pkt, (GCompareFunc)colo_packet_compare_icmp);
 478             break;
 479         default:
 480             result = g_queue_find_custom(&conn->secondary_list,
 481                      pkt, (GCompareFunc)colo_packet_compare_other);
 482             break;
 483         }
 484
 485         if (result) {
 486             ret = compare_chr_send(&s->chr_out, pkt->data, pkt->size);
 487             if (ret < 0) {
 488                 error_report("colo_send_primary_packet failed");
 489             }
 490             trace_colo_compare_main("packet same and release packet");
 491             g_queue_remove(&conn->secondary_list, result->data);
 492             packet_destroy(pkt, NULL);
 493         } else {
 494             /*
 495              * If one packet arrive late, the secondary_list or
 496              * primary_list will be empty, so we can't compare it
 497              * until next comparison.
 498              */
 499             trace_colo_compare_main("packet different");
 500             g_queue_push_tail(&conn->primary_list, pkt);
 501             /* TODO: colo_notify_checkpoint();*/
 502             break;
 503         }
 504     }
 505 }
 506
 507 static int compare_chr_send(CharBackend *out,
 508                             const uint8_t *buf,
 509                             uint32_t size)
 510 {
 511     int ret = 0;
 512     uint32_t len = htonl(size);
 513
 514     if (!size) {
 515         return 0;
 516     }
 517
 518     ret = qemu_chr_fe_write_all(out, (uint8_t *)&len, sizeof(len));
 519     if (ret != sizeof(len)) {
 520         goto err;
 521     }
 522
 523     ret = qemu_chr_fe_write_all(out, (uint8_t *)buf, size);
 524     if (ret != size) {
 525         goto err;
 526     }
 527
 528     return 0;
 529
 530 err:
 531     return ret < 0 ? ret : -EIO;
 532 }
 533
 534 static int compare_chr_can_read(void *opaque)
 535 {
 536     return COMPARE_READ_LEN_MAX;
 537 }
 538
 539 /*
 540  * Called from the main thread on the primary for packets
 541  * arriving over the socket from the primary.
 542  */
 543 static void compare_pri_chr_in(void *opaque, const uint8_t *buf, int size)
 544 {
 545     CompareState *s = COLO_COMPARE(opaque);
 546     int ret;
 547
 548     ret = net_fill_rstate(&s->pri_rs, buf, size);
 549     if (ret == -1) {
 550         qemu_chr_fe_set_handlers(&s->chr_pri_in, NULL, NULL, NULL, NULL,
 551                                  NULL, NULL, true);
 552         error_report("colo-compare primary_in error");
 553     }
 554 }
 555
 556 /*
 557  * Called from the main thread on the primary for packets
 558  * arriving over the socket from the secondary.
 559  */
 560 static void compare_sec_chr_in(void *opaque, const uint8_t *buf, int size)
 561 {
 562     CompareState *s = COLO_COMPARE(opaque);
 563     int ret;
 564
 565     ret = net_fill_rstate(&s->sec_rs, buf, size);
 566     if (ret == -1) {
 567         qemu_chr_fe_set_handlers(&s->chr_sec_in, NULL, NULL, NULL, NULL,
 568                                  NULL, NULL, true);
 569         error_report("colo-compare secondary_in error");
 570     }
 571 }
 572
 573 /*
 574  * Check old packet regularly so it can watch for any packets
 575  * that the secondary hasn't produced equivalents of.
 576  */
 577 static gboolean check_old_packet_regular(void *opaque)
 578 {
 579     CompareState *s = opaque;
 580
 581     /* if have old packet we will notify checkpoint */
 582     colo_old_packet_check(s);
 583
 584     return TRUE;
 585 }
 586
 587 static void *colo_compare_thread(void *opaque)
 588 {
 589     CompareState *s = opaque;
 590     GSource *timeout_source;
 591
 592     s->worker_context = g_main_context_new();
 593
 594     qemu_chr_fe_set_handlers(&s->chr_pri_in, compare_chr_can_read,
 595                              compare_pri_chr_in, NULL, NULL,
 596                              s, s->worker_context, true);
 597     qemu_chr_fe_set_handlers(&s->chr_sec_in, compare_chr_can_read,
 598                              compare_sec_chr_in, NULL, NULL,
 599                              s, s->worker_context, true);
 600
 601     s->compare_loop = g_main_loop_new(s->worker_context, FALSE);
 602
 603     /* To kick any packets that the secondary doesn't match */
 604     timeout_source = g_timeout_source_new(REGULAR_PACKET_CHECK_MS);
 605     g_source_set_callback(timeout_source,
 606                           (GSourceFunc)check_old_packet_regular, s, NULL);
 607     g_source_attach(timeout_source, s->worker_context);
 608
 609     g_main_loop_run(s->compare_loop);
 610
 611     g_source_unref(timeout_source);
 612     g_main_loop_unref(s->compare_loop);
 613     g_main_context_unref(s->worker_context);
 614     return NULL;
 615 }
 616
 617 static char *compare_get_pri_indev(Object *obj, Error **errp)
 618 {
 619     CompareState *s = COLO_COMPARE(obj);
 620
 621     return g_strdup(s->pri_indev);
 622 }
 623
 624 static void compare_set_pri_indev(Object *obj, const char *value, Error **errp)
 625 {
 626     CompareState *s = COLO_COMPARE(obj);
 627
 628     g_free(s->pri_indev);
 629     s->pri_indev = g_strdup(value);
 630 }
 631
 632 static char *compare_get_sec_indev(Object *obj, Error **errp)
 633 {
 634     CompareState *s = COLO_COMPARE(obj);
 635
 636     return g_strdup(s->sec_indev);
 637 }
 638
 639 static void compare_set_sec_indev(Object *obj, const char *value, Error **errp)
 640 {
 641     CompareState *s = COLO_COMPARE(obj);
 642
 643     g_free(s->sec_indev);
 644     s->sec_indev = g_strdup(value);
 645 }
 646
 647 static char *compare_get_outdev(Object *obj, Error **errp)
 648 {
 649     CompareState *s = COLO_COMPARE(obj);
 650
 651     return g_strdup(s->outdev);
 652 }
 653
 654 static void compare_set_outdev(Object *obj, const char *value, Error **errp)
 655 {
 656     CompareState *s = COLO_COMPARE(obj);
 657
 658     g_free(s->outdev);
 659     s->outdev = g_strdup(value);
 660 }
 661
 662 static void compare_pri_rs_finalize(SocketReadState *pri_rs)
 663 {
 664     CompareState *s = container_of(pri_rs, CompareState, pri_rs);
 665
 666     if (packet_enqueue(s, PRIMARY_IN)) {
 667         trace_colo_compare_main("primary: unsupported packet in");
 668         compare_chr_send(&s->chr_out, pri_rs->buf, pri_rs->packet_len);
 669     } else {
 670         /* compare connection */
 671         g_queue_foreach(&s->conn_list, colo_compare_connection, s);
 672     }
 673 }
 674
 675 static void compare_sec_rs_finalize(SocketReadState *sec_rs)
 676 {
 677     CompareState *s = container_of(sec_rs, CompareState, sec_rs);
 678
 679     if (packet_enqueue(s, SECONDARY_IN)) {
 680         trace_colo_compare_main("secondary: unsupported packet in");
 681     } else {
 682         /* compare connection */
 683         g_queue_foreach(&s->conn_list, colo_compare_connection, s);
 684     }
 685 }
 686
 687
 688 /*
 689  * Return 0 is success.
 690  * Return 1 is failed.
 691  */
 692 static int find_and_check_chardev(Chardev **chr,
 693                                   char *chr_name,
 694                                   Error **errp)
 695 {
 696     *chr = qemu_chr_find(chr_name);
 697     if (*chr == NULL) {
 698         error_setg(errp, "Device '%s' not found",
 699                    chr_name);
 700         return 1;
 701     }
 702
 703     if (!qemu_chr_has_feature(*chr, QEMU_CHAR_FEATURE_RECONNECTABLE)) {
 704         error_setg(errp, "chardev \"%s\" is not reconnectable",
 705                    chr_name);
 706         return 1;
 707     }
 708
 709     return 0;
 710 }
 711
 712 /*
 713  * Called from the main thread on the primary
 714  * to setup colo-compare.
 715  */
 716 static void colo_compare_complete(UserCreatable *uc, Error **errp)
 717 {
 718     CompareState *s = COLO_COMPARE(uc);
 719     Chardev *chr;
 720     char thread_name[64];
 721     static int compare_id;
 722
 723     if (!s->pri_indev || !s->sec_indev || !s->outdev) {
 724         error_setg(errp, "colo compare needs 'primary_in' ,"
 725                    "'secondary_in','outdev' property set");
 726         return;
 727     } else if (!strcmp(s->pri_indev, s->outdev) ||
 728                !strcmp(s->sec_indev, s->outdev) ||
 729                !strcmp(s->pri_indev, s->sec_indev)) {
 730         error_setg(errp, "'indev' and 'outdev' could not be same "
 731                    "for compare module");
 732         return;
 733     }
 734
 735     if (find_and_check_chardev(&chr, s->pri_indev, errp) ||
 736         !qemu_chr_fe_init(&s->chr_pri_in, chr, errp)) {
 737         return;
 738     }
 739
 740     if (find_and_check_chardev(&chr, s->sec_indev, errp) ||
 741         !qemu_chr_fe_init(&s->chr_sec_in, chr, errp)) {
 742         return;
 743     }
 744
 745     if (find_and_check_chardev(&chr, s->outdev, errp) ||
 746         !qemu_chr_fe_init(&s->chr_out, chr, errp)) {
 747         return;
 748     }
 749
 750     net_socket_rs_init(&s->pri_rs, compare_pri_rs_finalize, false);
 751     net_socket_rs_init(&s->sec_rs, compare_sec_rs_finalize, false);
 752
 753     g_queue_init(&s->conn_list);
 754
 755     s->connection_track_table = g_hash_table_new_full(connection_key_hash,
 756                                                       connection_key_equal,
 757                                                       g_free,
 758                                                       connection_destroy);
 759
 760     sprintf(thread_name, "colo-compare %d", compare_id);
 761     qemu_thread_create(&s->thread, thread_name,
 762                        colo_compare_thread, s,
 763                        QEMU_THREAD_JOINABLE);
 764     compare_id++;
 765
 766     return;
 767 }
 768
 769 static void colo_flush_packets(void *opaque, void *user_data)
 770 {
 771     CompareState *s = user_data;
 772     Connection *conn = opaque;
 773     Packet *pkt = NULL;
 774
 775     while (!g_queue_is_empty(&conn->primary_list)) {
 776         pkt = g_queue_pop_head(&conn->primary_list);
 777         compare_chr_send(&s->chr_out, pkt->data, pkt->size);
 778         packet_destroy(pkt, NULL);
 779     }
 780     while (!g_queue_is_empty(&conn->secondary_list)) {
 781         pkt = g_queue_pop_head(&conn->secondary_list);
 782         packet_destroy(pkt, NULL);
 783     }
 784 }
 785
 786 static void colo_compare_class_init(ObjectClass *oc, void *data)
 787 {
 788     UserCreatableClass *ucc = USER_CREATABLE_CLASS(oc);
 789
 790     ucc->complete = colo_compare_complete;
 791 }
 792
 793 static void colo_compare_init(Object *obj)
 794 {
 795     object_property_add_str(obj, "primary_in",
 796                             compare_get_pri_indev, compare_set_pri_indev,
 797                             NULL);
 798     object_property_add_str(obj, "secondary_in",
 799                             compare_get_sec_indev, compare_set_sec_indev,
 800                             NULL);
 801     object_property_add_str(obj, "outdev",
 802                             compare_get_outdev, compare_set_outdev,
 803                             NULL);
 804 }
 805
 806 static void colo_compare_finalize(Object *obj)
 807 {
 808     CompareState *s = COLO_COMPARE(obj);
 809
 810     qemu_chr_fe_deinit(&s->chr_pri_in, false);
 811     qemu_chr_fe_deinit(&s->chr_sec_in, false);
 812     qemu_chr_fe_deinit(&s->chr_out, false);
 813
 814     g_main_loop_quit(s->compare_loop);
 815     qemu_thread_join(&s->thread);
 816
 817     /* Release all unhandled packets after compare thead exited */
 818     g_queue_foreach(&s->conn_list, colo_flush_packets, s);
 819
 820     g_queue_clear(&s->conn_list);
 821
 822     g_hash_table_destroy(s->connection_track_table);
 823     g_free(s->pri_indev);
 824     g_free(s->sec_indev);
 825     g_free(s->outdev);
 826 }
 827
 828 static const TypeInfo colo_compare_info = {
 829     .name = TYPE_COLO_COMPARE,
 830     .parent = TYPE_OBJECT,
 831     .instance_size = sizeof(CompareState),
 832     .instance_init = colo_compare_init,
 833     .instance_finalize = colo_compare_finalize,
 834     .class_size = sizeof(CompareClass),
 835     .class_init = colo_compare_class_init,
 836     .interfaces = (InterfaceInfo[]) {
 837         { TYPE_USER_CREATABLE },
 838         { }
 839     }
 840 };
 841
 842 static void register_types(void)
 843 {
 844     type_register_static(&colo_compare_info);
 845 }
 846
 847 type_init(register_types);