/* * COarse-grain LOck-stepping Virtual Machines for Non-stop Service (COLO) * (a.k.a. Fault Tolerance or Continuous Replication) * * Copyright (c) 2016 HUAWEI TECHNOLOGIES CO., LTD. * Copyright (c) 2016 FUJITSU LIMITED * Copyright (c) 2016 Intel Corporation * * Author: Zhang Chen * * This work is licensed under the terms of the GNU GPL, version 2 or * later. See the COPYING file in the top-level directory. */ #include "qemu/osdep.h" #include "qemu/error-report.h" #include "trace.h" #include "qemu-common.h" #include "qapi/qmp/qerror.h" #include "qapi/error.h" #include "net/net.h" #include "net/eth.h" #include "qom/object_interfaces.h" #include "qemu/iov.h" #include "qom/object.h" #include "qemu/typedefs.h" #include "net/queue.h" #include "chardev/char-fe.h" #include "qemu/sockets.h" #include "qapi-visit.h" #include "net/colo.h" #define TYPE_COLO_COMPARE "colo-compare" #define COLO_COMPARE(obj) \ OBJECT_CHECK(CompareState, (obj), TYPE_COLO_COMPARE) #define COMPARE_READ_LEN_MAX NET_BUFSIZE #define MAX_QUEUE_SIZE 1024 /* TODO: Should be configurable */ #define REGULAR_PACKET_CHECK_MS 3000 /* + CompareState ++ | | +---------------+ +---------------+ +---------------+ |conn list +--->conn +--------->conn | +---------------+ +---------------+ +---------------+ | | | | | | +---------------+ +---v----+ +---v----+ +---v----+ +---v----+ |primary | |secondary |primary | |secondary |packet | |packet + |packet | |packet + +--------+ +--------+ +--------+ +--------+ | | | | +---v----+ +---v----+ +---v----+ +---v----+ |primary | |secondary |primary | |secondary |packet | |packet + |packet | |packet + +--------+ +--------+ +--------+ +--------+ | | | | +---v----+ +---v----+ +---v----+ +---v----+ |primary | |secondary |primary | |secondary |packet | |packet + |packet | |packet + +--------+ +--------+ +--------+ +--------+ */ typedef struct CompareState { Object parent; char *pri_indev; char *sec_indev; char *outdev; CharBackend chr_pri_in; CharBackend chr_sec_in; CharBackend chr_out; SocketReadState pri_rs; SocketReadState sec_rs; /* connection list: the connections belonged to this NIC could be found * in this list. * element type: Connection */ GQueue conn_list; /* hashtable to save connection */ GHashTable *connection_track_table; /* compare thread, a thread for each NIC */ QemuThread thread; GMainContext *worker_context; GMainLoop *compare_loop; } CompareState; typedef struct CompareClass { ObjectClass parent_class; } CompareClass; enum { PRIMARY_IN = 0, SECONDARY_IN, }; static int compare_chr_send(CharBackend *out, const uint8_t *buf, uint32_t size); static gint seq_sorter(Packet *a, Packet *b, gpointer data) { struct tcphdr *atcp, *btcp; atcp = (struct tcphdr *)(a->transport_header); btcp = (struct tcphdr *)(b->transport_header); return ntohl(atcp->th_seq) - ntohl(btcp->th_seq); } /* * Return 0 on success, if return -1 means the pkt * is unsupported(arp and ipv6) and will be sent later */ static int packet_enqueue(CompareState *s, int mode) { ConnectionKey key; Packet *pkt = NULL; Connection *conn; if (mode == PRIMARY_IN) { pkt = packet_new(s->pri_rs.buf, s->pri_rs.packet_len); } else { pkt = packet_new(s->sec_rs.buf, s->sec_rs.packet_len); } if (parse_packet_early(pkt)) { packet_destroy(pkt, NULL); pkt = NULL; return -1; } fill_connection_key(pkt, &key); conn = connection_get(s->connection_track_table, &key, &s->conn_list); if (!conn->processing) { g_queue_push_tail(&s->conn_list, conn); conn->processing = true; } if (mode == PRIMARY_IN) { if (g_queue_get_length(&conn->primary_list) <= MAX_QUEUE_SIZE) { g_queue_push_tail(&conn->primary_list, pkt); if (conn->ip_proto == IPPROTO_TCP) { g_queue_sort(&conn->primary_list, (GCompareDataFunc)seq_sorter, NULL); } } else { error_report("colo compare primary queue size too big," "drop packet"); } } else { if (g_queue_get_length(&conn->secondary_list) <= MAX_QUEUE_SIZE) { g_queue_push_tail(&conn->secondary_list, pkt); if (conn->ip_proto == IPPROTO_TCP) { g_queue_sort(&conn->secondary_list, (GCompareDataFunc)seq_sorter, NULL); } } else { error_report("colo compare secondary queue size too big," "drop packet"); } } return 0; } /* * The IP packets sent by primary and secondary * will be compared in here * TODO support ip fragment, Out-Of-Order * return: 0 means packet same * > 0 || < 0 means packet different */ static int colo_packet_compare_common(Packet *ppkt, Packet *spkt, int offset) { if (trace_event_get_state(TRACE_COLO_COMPARE_MISCOMPARE)) { char pri_ip_src[20], pri_ip_dst[20], sec_ip_src[20], sec_ip_dst[20]; strcpy(pri_ip_src, inet_ntoa(ppkt->ip->ip_src)); strcpy(pri_ip_dst, inet_ntoa(ppkt->ip->ip_dst)); strcpy(sec_ip_src, inet_ntoa(spkt->ip->ip_src)); strcpy(sec_ip_dst, inet_ntoa(spkt->ip->ip_dst)); trace_colo_compare_ip_info(ppkt->size, pri_ip_src, pri_ip_dst, spkt->size, sec_ip_src, sec_ip_dst); } if (ppkt->size == spkt->size) { return memcmp(ppkt->data + offset, spkt->data + offset, spkt->size - offset); } else { trace_colo_compare_main("Net packet size are not the same"); return -1; } } /* * Called from the compare thread on the primary * for compare tcp packet * compare_tcp copied from Dr. David Alan Gilbert's branch */ static int colo_packet_compare_tcp(Packet *spkt, Packet *ppkt) { struct tcphdr *ptcp, *stcp; int res; trace_colo_compare_main("compare tcp"); ptcp = (struct tcphdr *)ppkt->transport_header; stcp = (struct tcphdr *)spkt->transport_header; /* * The 'identification' field in the IP header is *very* random * it almost never matches. Fudge this by ignoring differences in * unfragmented packets; they'll normally sort themselves out if different * anyway, and it should recover at the TCP level. * An alternative would be to get both the primary and secondary to rewrite * somehow; but that would need some sync traffic to sync the state */ if (ntohs(ppkt->ip->ip_off) & IP_DF) { spkt->ip->ip_id = ppkt->ip->ip_id; /* and the sum will be different if the IDs were different */ spkt->ip->ip_sum = ppkt->ip->ip_sum; } /* * Check tcp header length for tcp option field. * th_off > 5 means this tcp packet have options field. * The tcp options maybe always different. * for example: * From RFC 7323. * TCP Timestamps option (TSopt): * Kind: 8 * * Length: 10 bytes * * +-------+-------+---------------------+---------------------+ * |Kind=8 | 10 | TS Value (TSval) |TS Echo Reply (TSecr)| * +-------+-------+---------------------+---------------------+ * 1 1 4 4 * * In this case the primary guest's timestamp always different with * the secondary guest's timestamp. COLO just focus on payload, * so we just need skip this field. */ if (ptcp->th_off > 5) { ptrdiff_t tcp_offset; tcp_offset = ppkt->transport_header - (uint8_t *)ppkt->data + (ptcp->th_off * 4); res = colo_packet_compare_common(ppkt, spkt, tcp_offset); } else if (ptcp->th_sum == stcp->th_sum) { res = colo_packet_compare_common(ppkt, spkt, ETH_HLEN); } else { res = -1; } if (res != 0 && trace_event_get_state(TRACE_COLO_COMPARE_MISCOMPARE)) { char pri_ip_src[20], pri_ip_dst[20], sec_ip_src[20], sec_ip_dst[20]; strcpy(pri_ip_src, inet_ntoa(ppkt->ip->ip_src)); strcpy(pri_ip_dst, inet_ntoa(ppkt->ip->ip_dst)); strcpy(sec_ip_src, inet_ntoa(spkt->ip->ip_src)); strcpy(sec_ip_dst, inet_ntoa(spkt->ip->ip_dst)); trace_colo_compare_ip_info(ppkt->size, pri_ip_src, pri_ip_dst, spkt->size, sec_ip_src, sec_ip_dst); trace_colo_compare_tcp_info("pri tcp packet", ntohl(ptcp->th_seq), ntohl(ptcp->th_ack), res, ptcp->th_flags, ppkt->size); trace_colo_compare_tcp_info("sec tcp packet", ntohl(stcp->th_seq), ntohl(stcp->th_ack), res, stcp->th_flags, spkt->size); qemu_hexdump((char *)ppkt->data, stderr, "colo-compare ppkt", ppkt->size); qemu_hexdump((char *)spkt->data, stderr, "colo-compare spkt", spkt->size); } return res; } /* * Called from the compare thread on the primary * for compare udp packet */ static int colo_packet_compare_udp(Packet *spkt, Packet *ppkt) { int ret; int network_header_length = ppkt->ip->ip_hl * 4; trace_colo_compare_main("compare udp"); /* * Because of ppkt and spkt are both in the same connection, * The ppkt's src ip, dst ip, src port, dst port, ip_proto all are * same with spkt. In addition, IP header's Identification is a random * field, we can handle it in IP fragmentation function later. * COLO just concern the response net packet payload from primary guest * and secondary guest are same or not, So we ignored all IP header include * other field like TOS,TTL,IP Checksum. we only need to compare * the ip payload here. */ ret = colo_packet_compare_common(ppkt, spkt, network_header_length + ETH_HLEN); if (ret) { trace_colo_compare_udp_miscompare("primary pkt size", ppkt->size); trace_colo_compare_udp_miscompare("Secondary pkt size", spkt->size); if (trace_event_get_state(TRACE_COLO_COMPARE_MISCOMPARE)) { qemu_hexdump((char *)ppkt->data, stderr, "colo-compare pri pkt", ppkt->size); qemu_hexdump((char *)spkt->data, stderr, "colo-compare sec pkt", spkt->size); } } return ret; } /* * Called from the compare thread on the primary * for compare icmp packet */ static int colo_packet_compare_icmp(Packet *spkt, Packet *ppkt) { int network_header_length = ppkt->ip->ip_hl * 4; trace_colo_compare_main("compare icmp"); /* * Because of ppkt and spkt are both in the same connection, * The ppkt's src ip, dst ip, src port, dst port, ip_proto all are * same with spkt. In addition, IP header's Identification is a random * field, we can handle it in IP fragmentation function later. * COLO just concern the response net packet payload from primary guest * and secondary guest are same or not, So we ignored all IP header include * other field like TOS,TTL,IP Checksum. we only need to compare * the ip payload here. */ if (colo_packet_compare_common(ppkt, spkt, network_header_length + ETH_HLEN)) { trace_colo_compare_icmp_miscompare("primary pkt size", ppkt->size); trace_colo_compare_icmp_miscompare("Secondary pkt size", spkt->size); if (trace_event_get_state(TRACE_COLO_COMPARE_MISCOMPARE)) { qemu_hexdump((char *)ppkt->data, stderr, "colo-compare pri pkt", ppkt->size); qemu_hexdump((char *)spkt->data, stderr, "colo-compare sec pkt", spkt->size); } return -1; } else { return 0; } } /* * Called from the compare thread on the primary * for compare other packet */ static int colo_packet_compare_other(Packet *spkt, Packet *ppkt) { trace_colo_compare_main("compare other"); if (trace_event_get_state(TRACE_COLO_COMPARE_MISCOMPARE)) { char pri_ip_src[20], pri_ip_dst[20], sec_ip_src[20], sec_ip_dst[20]; strcpy(pri_ip_src, inet_ntoa(ppkt->ip->ip_src)); strcpy(pri_ip_dst, inet_ntoa(ppkt->ip->ip_dst)); strcpy(sec_ip_src, inet_ntoa(spkt->ip->ip_src)); strcpy(sec_ip_dst, inet_ntoa(spkt->ip->ip_dst)); trace_colo_compare_ip_info(ppkt->size, pri_ip_src, pri_ip_dst, spkt->size, sec_ip_src, sec_ip_dst); } return colo_packet_compare_common(ppkt, spkt, 0); } static int colo_old_packet_check_one(Packet *pkt, int64_t *check_time) { int64_t now = qemu_clock_get_ms(QEMU_CLOCK_HOST); if ((now - pkt->creation_ms) > (*check_time)) { trace_colo_old_packet_check_found(pkt->creation_ms); return 0; } else { return 1; } } static int colo_old_packet_check_one_conn(Connection *conn, void *user_data) { GList *result = NULL; int64_t check_time = REGULAR_PACKET_CHECK_MS; result = g_queue_find_custom(&conn->primary_list, &check_time, (GCompareFunc)colo_old_packet_check_one); if (result) { /* do checkpoint will flush old packet */ /* TODO: colo_notify_checkpoint();*/ return 0; } return 1; } /* * Look for old packets that the secondary hasn't matched, * if we have some then we have to checkpoint to wake * the secondary up. */ static void colo_old_packet_check(void *opaque) { CompareState *s = opaque; /* * If we find one old packet, stop finding job and notify * COLO frame do checkpoint. */ g_queue_find_custom(&s->conn_list, NULL, (GCompareFunc)colo_old_packet_check_one_conn); } /* * Called from the compare thread on the primary * for compare connection */ static void colo_compare_connection(void *opaque, void *user_data) { CompareState *s = user_data; Connection *conn = opaque; Packet *pkt = NULL; GList *result = NULL; int ret; while (!g_queue_is_empty(&conn->primary_list) && !g_queue_is_empty(&conn->secondary_list)) { pkt = g_queue_pop_tail(&conn->primary_list); switch (conn->ip_proto) { case IPPROTO_TCP: result = g_queue_find_custom(&conn->secondary_list, pkt, (GCompareFunc)colo_packet_compare_tcp); break; case IPPROTO_UDP: result = g_queue_find_custom(&conn->secondary_list, pkt, (GCompareFunc)colo_packet_compare_udp); break; case IPPROTO_ICMP: result = g_queue_find_custom(&conn->secondary_list, pkt, (GCompareFunc)colo_packet_compare_icmp); break; default: result = g_queue_find_custom(&conn->secondary_list, pkt, (GCompareFunc)colo_packet_compare_other); break; } if (result) { ret = compare_chr_send(&s->chr_out, pkt->data, pkt->size); if (ret < 0) { error_report("colo_send_primary_packet failed"); } trace_colo_compare_main("packet same and release packet"); g_queue_remove(&conn->secondary_list, result->data); packet_destroy(pkt, NULL); } else { /* * If one packet arrive late, the secondary_list or * primary_list will be empty, so we can't compare it * until next comparison. */ trace_colo_compare_main("packet different"); g_queue_push_tail(&conn->primary_list, pkt); /* TODO: colo_notify_checkpoint();*/ break; } } } static int compare_chr_send(CharBackend *out, const uint8_t *buf, uint32_t size) { int ret = 0; uint32_t len = htonl(size); if (!size) { return 0; } ret = qemu_chr_fe_write_all(out, (uint8_t *)&len, sizeof(len)); if (ret != sizeof(len)) { goto err; } ret = qemu_chr_fe_write_all(out, (uint8_t *)buf, size); if (ret != size) { goto err; } return 0; err: return ret < 0 ? ret : -EIO; } static int compare_chr_can_read(void *opaque) { return COMPARE_READ_LEN_MAX; } /* * Called from the main thread on the primary for packets * arriving over the socket from the primary. */ static void compare_pri_chr_in(void *opaque, const uint8_t *buf, int size) { CompareState *s = COLO_COMPARE(opaque); int ret; ret = net_fill_rstate(&s->pri_rs, buf, size); if (ret == -1) { qemu_chr_fe_set_handlers(&s->chr_pri_in, NULL, NULL, NULL, NULL, NULL, NULL, true); error_report("colo-compare primary_in error"); } } /* * Called from the main thread on the primary for packets * arriving over the socket from the secondary. */ static void compare_sec_chr_in(void *opaque, const uint8_t *buf, int size) { CompareState *s = COLO_COMPARE(opaque); int ret; ret = net_fill_rstate(&s->sec_rs, buf, size); if (ret == -1) { qemu_chr_fe_set_handlers(&s->chr_sec_in, NULL, NULL, NULL, NULL, NULL, NULL, true); error_report("colo-compare secondary_in error"); } } /* * Check old packet regularly so it can watch for any packets * that the secondary hasn't produced equivalents of. */ static gboolean check_old_packet_regular(void *opaque) { CompareState *s = opaque; /* if have old packet we will notify checkpoint */ colo_old_packet_check(s); return TRUE; } static void *colo_compare_thread(void *opaque) { CompareState *s = opaque; GSource *timeout_source; s->worker_context = g_main_context_new(); qemu_chr_fe_set_handlers(&s->chr_pri_in, compare_chr_can_read, compare_pri_chr_in, NULL, NULL, s, s->worker_context, true); qemu_chr_fe_set_handlers(&s->chr_sec_in, compare_chr_can_read, compare_sec_chr_in, NULL, NULL, s, s->worker_context, true); s->compare_loop = g_main_loop_new(s->worker_context, FALSE); /* To kick any packets that the secondary doesn't match */ timeout_source = g_timeout_source_new(REGULAR_PACKET_CHECK_MS); g_source_set_callback(timeout_source, (GSourceFunc)check_old_packet_regular, s, NULL); g_source_attach(timeout_source, s->worker_context); g_main_loop_run(s->compare_loop); g_source_unref(timeout_source); g_main_loop_unref(s->compare_loop); g_main_context_unref(s->worker_context); return NULL; } static char *compare_get_pri_indev(Object *obj, Error **errp) { CompareState *s = COLO_COMPARE(obj); return g_strdup(s->pri_indev); } static void compare_set_pri_indev(Object *obj, const char *value, Error **errp) { CompareState *s = COLO_COMPARE(obj); g_free(s->pri_indev); s->pri_indev = g_strdup(value); } static char *compare_get_sec_indev(Object *obj, Error **errp) { CompareState *s = COLO_COMPARE(obj); return g_strdup(s->sec_indev); } static void compare_set_sec_indev(Object *obj, const char *value, Error **errp) { CompareState *s = COLO_COMPARE(obj); g_free(s->sec_indev); s->sec_indev = g_strdup(value); } static char *compare_get_outdev(Object *obj, Error **errp) { CompareState *s = COLO_COMPARE(obj); return g_strdup(s->outdev); } static void compare_set_outdev(Object *obj, const char *value, Error **errp) { CompareState *s = COLO_COMPARE(obj); g_free(s->outdev); s->outdev = g_strdup(value); } static void compare_pri_rs_finalize(SocketReadState *pri_rs) { CompareState *s = container_of(pri_rs, CompareState, pri_rs); if (packet_enqueue(s, PRIMARY_IN)) { trace_colo_compare_main("primary: unsupported packet in"); compare_chr_send(&s->chr_out, pri_rs->buf, pri_rs->packet_len); } else { /* compare connection */ g_queue_foreach(&s->conn_list, colo_compare_connection, s); } } static void compare_sec_rs_finalize(SocketReadState *sec_rs) { CompareState *s = container_of(sec_rs, CompareState, sec_rs); if (packet_enqueue(s, SECONDARY_IN)) { trace_colo_compare_main("secondary: unsupported packet in"); } else { /* compare connection */ g_queue_foreach(&s->conn_list, colo_compare_connection, s); } } /* * Return 0 is success. * Return 1 is failed. */ static int find_and_check_chardev(Chardev **chr, char *chr_name, Error **errp) { *chr = qemu_chr_find(chr_name); if (*chr == NULL) { error_setg(errp, "Device '%s' not found", chr_name); return 1; } if (!qemu_chr_has_feature(*chr, QEMU_CHAR_FEATURE_RECONNECTABLE)) { error_setg(errp, "chardev \"%s\" is not reconnectable", chr_name); return 1; } return 0; } /* * Called from the main thread on the primary * to setup colo-compare. */ static void colo_compare_complete(UserCreatable *uc, Error **errp) { CompareState *s = COLO_COMPARE(uc); Chardev *chr; char thread_name[64]; static int compare_id; if (!s->pri_indev || !s->sec_indev || !s->outdev) { error_setg(errp, "colo compare needs 'primary_in' ," "'secondary_in','outdev' property set"); return; } else if (!strcmp(s->pri_indev, s->outdev) || !strcmp(s->sec_indev, s->outdev) || !strcmp(s->pri_indev, s->sec_indev)) { error_setg(errp, "'indev' and 'outdev' could not be same " "for compare module"); return; } if (find_and_check_chardev(&chr, s->pri_indev, errp) || !qemu_chr_fe_init(&s->chr_pri_in, chr, errp)) { return; } if (find_and_check_chardev(&chr, s->sec_indev, errp) || !qemu_chr_fe_init(&s->chr_sec_in, chr, errp)) { return; } if (find_and_check_chardev(&chr, s->outdev, errp) || !qemu_chr_fe_init(&s->chr_out, chr, errp)) { return; } net_socket_rs_init(&s->pri_rs, compare_pri_rs_finalize); net_socket_rs_init(&s->sec_rs, compare_sec_rs_finalize); g_queue_init(&s->conn_list); s->connection_track_table = g_hash_table_new_full(connection_key_hash, connection_key_equal, g_free, connection_destroy); sprintf(thread_name, "colo-compare %d", compare_id); qemu_thread_create(&s->thread, thread_name, colo_compare_thread, s, QEMU_THREAD_JOINABLE); compare_id++; return; } static void colo_flush_packets(void *opaque, void *user_data) { CompareState *s = user_data; Connection *conn = opaque; Packet *pkt = NULL; while (!g_queue_is_empty(&conn->primary_list)) { pkt = g_queue_pop_head(&conn->primary_list); compare_chr_send(&s->chr_out, pkt->data, pkt->size); packet_destroy(pkt, NULL); } while (!g_queue_is_empty(&conn->secondary_list)) { pkt = g_queue_pop_head(&conn->secondary_list); packet_destroy(pkt, NULL); } } static void colo_compare_class_init(ObjectClass *oc, void *data) { UserCreatableClass *ucc = USER_CREATABLE_CLASS(oc); ucc->complete = colo_compare_complete; } static void colo_compare_init(Object *obj) { object_property_add_str(obj, "primary_in", compare_get_pri_indev, compare_set_pri_indev, NULL); object_property_add_str(obj, "secondary_in", compare_get_sec_indev, compare_set_sec_indev, NULL); object_property_add_str(obj, "outdev", compare_get_outdev, compare_set_outdev, NULL); } static void colo_compare_finalize(Object *obj) { CompareState *s = COLO_COMPARE(obj); qemu_chr_fe_deinit(&s->chr_pri_in, false); qemu_chr_fe_deinit(&s->chr_sec_in, false); qemu_chr_fe_deinit(&s->chr_out, false); g_main_loop_quit(s->compare_loop); qemu_thread_join(&s->thread); /* Release all unhandled packets after compare thead exited */ g_queue_foreach(&s->conn_list, colo_flush_packets, s); g_queue_clear(&s->conn_list); g_hash_table_destroy(s->connection_track_table); g_free(s->pri_indev); g_free(s->sec_indev); g_free(s->outdev); } static const TypeInfo colo_compare_info = { .name = TYPE_COLO_COMPARE, .parent = TYPE_OBJECT, .instance_size = sizeof(CompareState), .instance_init = colo_compare_init, .instance_finalize = colo_compare_finalize, .class_size = sizeof(CompareClass), .class_init = colo_compare_class_init, .interfaces = (InterfaceInfo[]) { { TYPE_USER_CREATABLE }, { } } }; static void register_types(void) { type_register_static(&colo_compare_info); } type_init(register_types);