diff options
Diffstat (limited to 'net/colo-compare.c')
| -rw-r--r-- | net/colo-compare.c | 343 |
1 files changed, 225 insertions, 118 deletions
diff --git a/net/colo-compare.c b/net/colo-compare.c index f39ca02fc0..8622b0b35a 100644 --- a/net/colo-compare.c +++ b/net/colo-compare.c @@ -37,6 +37,9 @@ #define COMPARE_READ_LEN_MAX NET_BUFSIZE #define MAX_QUEUE_SIZE 1024 +#define COLO_COMPARE_FREE_PRIMARY 0x01 +#define COLO_COMPARE_FREE_SECONDARY 0x02 + /* TODO: Should be configurable */ #define REGULAR_PACKET_CHECK_MS 3000 @@ -111,14 +114,32 @@ static gint seq_sorter(Packet *a, Packet *b, gpointer data) return ntohl(atcp->th_seq) - ntohl(btcp->th_seq); } +static void fill_pkt_tcp_info(void *data, uint32_t *max_ack) +{ + Packet *pkt = data; + struct tcphdr *tcphd; + + tcphd = (struct tcphdr *)pkt->transport_header; + + pkt->tcp_seq = ntohl(tcphd->th_seq); + pkt->tcp_ack = ntohl(tcphd->th_ack); + *max_ack = *max_ack > pkt->tcp_ack ? *max_ack : pkt->tcp_ack; + pkt->header_size = pkt->transport_header - (uint8_t *)pkt->data + + (tcphd->th_off << 2) - pkt->vnet_hdr_len; + pkt->payload_size = pkt->size - pkt->header_size; + pkt->seq_end = pkt->tcp_seq + pkt->payload_size; + pkt->flags = tcphd->th_flags; +} + /* * Return 1 on success, if return 0 means the * packet will be dropped */ -static int colo_insert_packet(GQueue *queue, Packet *pkt) +static int colo_insert_packet(GQueue *queue, Packet *pkt, uint32_t *max_ack) { if (g_queue_get_length(queue) <= MAX_QUEUE_SIZE) { if (pkt->ip->ip_p == IPPROTO_TCP) { + fill_pkt_tcp_info(pkt, max_ack); g_queue_insert_sorted(queue, pkt, (GCompareDataFunc)seq_sorter, @@ -168,12 +189,12 @@ static int packet_enqueue(CompareState *s, int mode, Connection **con) } if (mode == PRIMARY_IN) { - if (!colo_insert_packet(&conn->primary_list, pkt)) { + if (!colo_insert_packet(&conn->primary_list, pkt, &conn->pack)) { error_report("colo compare primary queue size too big," "drop packet"); } } else { - if (!colo_insert_packet(&conn->secondary_list, pkt)) { + if (!colo_insert_packet(&conn->secondary_list, pkt, &conn->sack)) { error_report("colo compare secondary queue size too big," "drop packet"); } @@ -183,6 +204,25 @@ static int packet_enqueue(CompareState *s, int mode, Connection **con) return 0; } +static inline bool after(uint32_t seq1, uint32_t seq2) +{ + return (int32_t)(seq1 - seq2) > 0; +} + +static void colo_release_primary_pkt(CompareState *s, Packet *pkt) +{ + int ret; + ret = compare_chr_send(s, + pkt->data, + pkt->size, + pkt->vnet_hdr_len); + if (ret < 0) { + error_report("colo send primary packet failed"); + } + trace_colo_compare_main("packet same and release packet"); + packet_destroy(pkt, NULL); +} + /* * The IP packets sent by primary and secondary * will be compared in here @@ -214,104 +254,175 @@ static int colo_compare_packet_payload(Packet *ppkt, } /* - * 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) + * return true means that the payload is consist and + * need to make the next comparison, false means do + * the checkpoint +*/ +static bool colo_mark_tcp_pkt(Packet *ppkt, Packet *spkt, + int8_t *mark, uint32_t max_ack) { - struct tcphdr *ptcp, *stcp; - int res; + *mark = 0; + + if (ppkt->tcp_seq == spkt->tcp_seq && ppkt->seq_end == spkt->seq_end) { + if (colo_compare_packet_payload(ppkt, spkt, + ppkt->header_size, spkt->header_size, + ppkt->payload_size)) { + *mark = COLO_COMPARE_FREE_SECONDARY | COLO_COMPARE_FREE_PRIMARY; + return true; + } + } + if (ppkt->tcp_seq == spkt->tcp_seq && ppkt->seq_end == spkt->seq_end) { + if (colo_compare_packet_payload(ppkt, spkt, + ppkt->header_size, spkt->header_size, + ppkt->payload_size)) { + *mark = COLO_COMPARE_FREE_SECONDARY | COLO_COMPARE_FREE_PRIMARY; + return true; + } + } + + /* one part of secondary packet payload still need to be compared */ + if (!after(ppkt->seq_end, spkt->seq_end)) { + if (colo_compare_packet_payload(ppkt, spkt, + ppkt->header_size + ppkt->offset, + spkt->header_size + spkt->offset, + ppkt->payload_size - ppkt->offset)) { + if (!after(ppkt->tcp_ack, max_ack)) { + *mark = COLO_COMPARE_FREE_PRIMARY; + spkt->offset += ppkt->payload_size - ppkt->offset; + return true; + } else { + /* secondary guest hasn't ack the data, don't send + * out this packet + */ + return false; + } + } + } else { + /* primary packet is longer than secondary packet, compare + * the same part and mark the primary packet offset + */ + if (colo_compare_packet_payload(ppkt, spkt, + ppkt->header_size + ppkt->offset, + spkt->header_size + spkt->offset, + spkt->payload_size - spkt->offset)) { + *mark = COLO_COMPARE_FREE_SECONDARY; + ppkt->offset += spkt->payload_size - spkt->offset; + return true; + } + } - trace_colo_compare_main("compare tcp"); + return false; +} - ptcp = (struct tcphdr *)ppkt->transport_header; - stcp = (struct tcphdr *)spkt->transport_header; +static void colo_compare_tcp(CompareState *s, Connection *conn) +{ + Packet *ppkt = NULL, *spkt = NULL; + int8_t mark; /* - * 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; + * If ppkt and spkt have the same payload, but ppkt's ACK + * is greater than spkt's ACK, in this case we can not + * send the ppkt because it will cause the secondary guest + * to miss sending some data in the next. Therefore, we + * record the maximum ACK in the current queue at both + * primary side and secondary side. Only when the ack is + * less than the smaller of the two maximum ack, then we + * can ensure that the packet's payload is acknowledged by + * primary and secondary. + */ + uint32_t min_ack = conn->pack > conn->sack ? conn->sack : conn->pack; + +pri: + if (g_queue_is_empty(&conn->primary_list)) { + return; } + ppkt = g_queue_pop_head(&conn->primary_list); +sec: + if (g_queue_is_empty(&conn->secondary_list)) { + g_queue_push_head(&conn->primary_list, ppkt); + return; + } + spkt = g_queue_pop_head(&conn->secondary_list); - /* - * 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 (ppkt->tcp_seq == ppkt->seq_end) { + colo_release_primary_pkt(s, ppkt); + ppkt = NULL; + } - ptrdiff_t ptcp_offset, stcp_offset; + if (ppkt && conn->compare_seq && !after(ppkt->seq_end, conn->compare_seq)) { + trace_colo_compare_main("pri: this packet has compared"); + colo_release_primary_pkt(s, ppkt); + ppkt = NULL; + } - ptcp_offset = ppkt->transport_header - (uint8_t *)ppkt->data - + (ptcp->th_off << 2) - ppkt->vnet_hdr_len; - stcp_offset = spkt->transport_header - (uint8_t *)spkt->data - + (stcp->th_off << 2) - spkt->vnet_hdr_len; - if (ppkt->size - ptcp_offset == spkt->size - stcp_offset) { - res = colo_compare_packet_payload(ppkt, spkt, - ptcp_offset, stcp_offset, - ppkt->size - ptcp_offset); + if (spkt->tcp_seq == spkt->seq_end) { + packet_destroy(spkt, NULL); + if (!ppkt) { + goto pri; + } else { + goto sec; + } } else { - trace_colo_compare_main("TCP: payload size of packets are different"); - res = -1; + if (conn->compare_seq && !after(spkt->seq_end, conn->compare_seq)) { + trace_colo_compare_main("sec: this packet has compared"); + packet_destroy(spkt, NULL); + if (!ppkt) { + goto pri; + } else { + goto sec; + } + } + if (!ppkt) { + g_queue_push_head(&conn->secondary_list, spkt); + goto pri; + } } - if (res != 0 && - trace_event_get_state_backends(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); + if (colo_mark_tcp_pkt(ppkt, spkt, &mark, min_ack)) { + trace_colo_compare_tcp_info("pri", + ppkt->tcp_seq, ppkt->tcp_ack, + ppkt->header_size, ppkt->payload_size, + ppkt->offset, ppkt->flags); + + trace_colo_compare_tcp_info("sec", + spkt->tcp_seq, spkt->tcp_ack, + spkt->header_size, spkt->payload_size, + spkt->offset, spkt->flags); + + if (mark == COLO_COMPARE_FREE_PRIMARY) { + conn->compare_seq = ppkt->seq_end; + colo_release_primary_pkt(s, ppkt); + g_queue_push_head(&conn->secondary_list, spkt); + goto pri; + } + if (mark == COLO_COMPARE_FREE_SECONDARY) { + conn->compare_seq = spkt->seq_end; + packet_destroy(spkt, NULL); + goto sec; + } + if (mark == (COLO_COMPARE_FREE_PRIMARY | COLO_COMPARE_FREE_SECONDARY)) { + conn->compare_seq = ppkt->seq_end; + colo_release_primary_pkt(s, ppkt); + packet_destroy(spkt, NULL); + goto pri; + } + } else { + g_queue_push_head(&conn->primary_list, ppkt); + g_queue_push_head(&conn->secondary_list, spkt); qemu_hexdump((char *)ppkt->data, stderr, "colo-compare ppkt", ppkt->size); qemu_hexdump((char *)spkt->data, stderr, "colo-compare spkt", spkt->size); - } - return res; + /* + * colo_compare_inconsistent_notify(); + * TODO: notice to checkpoint(); + */ + } } + /* * Called from the compare thread on the primary * for compare udp packet @@ -477,53 +588,22 @@ static void colo_old_packet_check(void *opaque) (GCompareFunc)colo_old_packet_check_one_conn); } -/* - * Called from the compare thread on the primary - * for compare packet with secondary list of the - * specified connection when a new packet was - * queued to it. - */ -static void colo_compare_connection(void *opaque, void *user_data) +static void colo_compare_packet(CompareState *s, Connection *conn, + int (*HandlePacket)(Packet *spkt, + Packet *ppkt)) { - 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_head(&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; - } + result = g_queue_find_custom(&conn->secondary_list, + pkt, (GCompareFunc)HandlePacket); if (result) { - ret = compare_chr_send(s, - pkt->data, - pkt->size, - pkt->vnet_hdr_len); - if (ret < 0) { - error_report("colo_send_primary_packet failed"); - } - trace_colo_compare_main("packet same and release packet"); + colo_release_primary_pkt(s, pkt); g_queue_remove(&conn->secondary_list, result->data); - packet_destroy(pkt, NULL); } else { /* * If one packet arrive late, the secondary_list or @@ -538,6 +618,33 @@ static void colo_compare_connection(void *opaque, void *user_data) } } +/* + * Called from the compare thread on the primary + * for compare packet with secondary list of the + * specified connection when a new packet was + * queued to it. + */ +static void colo_compare_connection(void *opaque, void *user_data) +{ + CompareState *s = user_data; + Connection *conn = opaque; + + switch (conn->ip_proto) { + case IPPROTO_TCP: + colo_compare_tcp(s, conn); + break; + case IPPROTO_UDP: + colo_compare_packet(s, conn, colo_packet_compare_udp); + break; + case IPPROTO_ICMP: + colo_compare_packet(s, conn, colo_packet_compare_icmp); + break; + default: + colo_compare_packet(s, conn, colo_packet_compare_other); + break; + } +} + static int compare_chr_send(CompareState *s, const uint8_t *buf, uint32_t size, |