net/colo.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 "trace.h"
  17 #include "colo.h"
  18 #include "util.h"
  19
  20 uint32_t connection_key_hash(const void *opaque)
  21 {
  22     const ConnectionKey *key = opaque;
  23     uint32_t a, b, c;
  24
  25     /* Jenkins hash */
  26     a = b = c = JHASH_INITVAL + sizeof(*key);
  27     a += key->src.s_addr;
  28     b += key->dst.s_addr;
  29     c += (key->src_port | key->dst_port << 16);
  30     __jhash_mix(a, b, c);
  31
  32     a += key->ip_proto;
  33     __jhash_final(a, b, c);
  34
  35     return c;
  36 }
  37
  38 int connection_key_equal(const void *key1, const void *key2)
  39 {
  40     return memcmp(key1, key2, sizeof(ConnectionKey)) == 0;
  41 }
  42
  43 int parse_packet_early(Packet *pkt)
  44 {
  45     int network_length;
  46     static const uint8_t vlan[] = {0x81, 0x00};
  47     uint8_t *data = pkt->data + pkt->vnet_hdr_len;
  48     uint16_t l3_proto;
  49     ssize_t l2hdr_len;
  50
  51     if (data == NULL) {
  52         trace_colo_proxy_main_vnet_info("This packet is not parsed correctly, "
  53                                         "pkt->vnet_hdr_len", pkt->vnet_hdr_len);
  54         return 1;
  55     }
  56     l2hdr_len = eth_get_l2_hdr_length(data);
  57
  58     if (pkt->size < ETH_HLEN + pkt->vnet_hdr_len) {
  59         trace_colo_proxy_main("pkt->size < ETH_HLEN");
  60         return 1;
  61     }
  62
  63     /*
  64      * TODO: support vlan.
  65      */
  66     if (!memcmp(&data[12], vlan, sizeof(vlan))) {
  67         trace_colo_proxy_main("COLO-proxy don't support vlan");
  68         return 1;
  69     }
  70
  71     pkt->network_header = data + l2hdr_len;
  72
  73     const struct iovec l2vec = {
  74         .iov_base = (void *) data,
  75         .iov_len = l2hdr_len
  76     };
  77     l3_proto = eth_get_l3_proto(&l2vec, 1, l2hdr_len);
  78
  79     if (l3_proto != ETH_P_IP) {
  80         return 1;
  81     }
  82
  83     network_length = pkt->ip->ip_hl * 4;
  84     if (pkt->size < l2hdr_len + network_length + pkt->vnet_hdr_len) {
  85         trace_colo_proxy_main("pkt->size < network_header + network_length");
  86         return 1;
  87     }
  88     pkt->transport_header = pkt->network_header + network_length;
  89
  90     return 0;
  91 }
  92
  93 void extract_ip_and_port(uint32_t tmp_ports, ConnectionKey *key,
  94                          Packet *pkt, bool reverse)
  95 {
  96     if (reverse) {
  97         key->src = pkt->ip->ip_dst;
  98         key->dst = pkt->ip->ip_src;
  99         key->src_port = ntohs(tmp_ports & 0xffff);
 100         key->dst_port = ntohs(tmp_ports >> 16);
 101     } else {
 102         key->src = pkt->ip->ip_src;
 103         key->dst = pkt->ip->ip_dst;
 104         key->src_port = ntohs(tmp_ports >> 16);
 105         key->dst_port = ntohs(tmp_ports & 0xffff);
 106     }
 107 }
 108
 109 void fill_connection_key(Packet *pkt, ConnectionKey *key, bool reverse)
 110 {
 111     uint32_t tmp_ports = 0;
 112
 113     key->ip_proto = pkt->ip->ip_p;
 114
 115     switch (key->ip_proto) {
 116     case IPPROTO_TCP:
 117     case IPPROTO_UDP:
 118     case IPPROTO_DCCP:
 119     case IPPROTO_ESP:
 120     case IPPROTO_SCTP:
 121     case IPPROTO_UDPLITE:
 122         tmp_ports = *(uint32_t *)(pkt->transport_header);
 123         break;
 124     case IPPROTO_AH:
 125         tmp_ports = *(uint32_t *)(pkt->transport_header + 4);
 126         break;
 127     default:
 128         break;
 129     }
 130
 131     extract_ip_and_port(tmp_ports, key, pkt, reverse);
 132 }
 133
 134 Connection *connection_new(ConnectionKey *key)
 135 {
 136     Connection *conn = g_slice_new0(Connection);
 137
 138     conn->ip_proto = key->ip_proto;
 139     conn->processing = false;
 140     conn->tcp_state = TCPS_CLOSED;
 141     g_queue_init(&conn->primary_list);
 142     g_queue_init(&conn->secondary_list);
 143
 144     return conn;
 145 }
 146
 147 void connection_destroy(void *opaque)
 148 {
 149     Connection *conn = opaque;
 150
 151     g_queue_foreach(&conn->primary_list, packet_destroy, NULL);
 152     g_queue_clear(&conn->primary_list);
 153     g_queue_foreach(&conn->secondary_list, packet_destroy, NULL);
 154     g_queue_clear(&conn->secondary_list);
 155     g_slice_free(Connection, conn);
 156 }
 157
 158 Packet *packet_new(const void *data, int size, int vnet_hdr_len)
 159 {
 160     Packet *pkt = g_slice_new0(Packet);
 161
 162     pkt->data = g_memdup(data, size);
 163     pkt->size = size;
 164     pkt->creation_ms = qemu_clock_get_ms(QEMU_CLOCK_HOST);
 165     pkt->vnet_hdr_len = vnet_hdr_len;
 166
 167     return pkt;
 168 }
 169
 170 /*
 171  * packet_new_nocopy will not copy data, so the caller can't release
 172  * the data. And it will be released in packet_destroy.
 173  */
 174 Packet *packet_new_nocopy(void *data, int size, int vnet_hdr_len)
 175 {
 176     Packet *pkt = g_slice_new0(Packet);
 177
 178     pkt->data = data;
 179     pkt->size = size;
 180     pkt->creation_ms = qemu_clock_get_ms(QEMU_CLOCK_HOST);
 181     pkt->vnet_hdr_len = vnet_hdr_len;
 182
 183     return pkt;
 184 }
 185
 186 void packet_destroy(void *opaque, void *user_data)
 187 {
 188     Packet *pkt = opaque;
 189
 190     g_free(pkt->data);
 191     g_slice_free(Packet, pkt);
 192 }
 193
 194 void packet_destroy_partial(void *opaque, void *user_data)
 195 {
 196     Packet *pkt = opaque;
 197
 198     g_slice_free(Packet, pkt);
 199 }
 200
 201 /*
 202  * Clear hashtable, stop this hash growing really huge
 203  */
 204 void connection_hashtable_reset(GHashTable *connection_track_table)
 205 {
 206     g_hash_table_remove_all(connection_track_table);
 207 }
 208
 209 /* if not found, create a new connection and add to hash table */
 210 Connection *connection_get(GHashTable *connection_track_table,
 211                            ConnectionKey *key,
 212                            GQueue *conn_list)
 213 {
 214     Connection *conn = g_hash_table_lookup(connection_track_table, key);
 215
 216     if (conn == NULL) {
 217         ConnectionKey *new_key = g_memdup(key, sizeof(*key));
 218
 219         conn = connection_new(key);
 220
 221         if (g_hash_table_size(connection_track_table) > HASHTABLE_MAX_SIZE) {
 222             trace_colo_proxy_main("colo proxy connection hashtable full,"
 223                                   " clear it");
 224             connection_hashtable_reset(connection_track_table);
 225             /*
 226              * clear the conn_list
 227              */
 228             while (conn_list && !g_queue_is_empty(conn_list)) {
 229                 connection_destroy(g_queue_pop_head(conn_list));
 230             }
 231         }
 232
 233         g_hash_table_insert(connection_track_table, new_key, conn);
 234     }
 235
 236     return conn;
 237 }
 238
 239 bool connection_has_tracked(GHashTable *connection_track_table,
 240                             ConnectionKey *key)
 241 {
 242     Connection *conn = g_hash_table_lookup(connection_track_table, key);
 243
 244     return conn ? true : false;
 245 }