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;
  48     uint16_t l3_proto;
  49     ssize_t l2hdr_len;
  50
  51     assert(data);
  52
  53     /* Check the received vnet_hdr_len then add the offset */
  54     if ((pkt->vnet_hdr_len > sizeof(struct virtio_net_hdr_v1_hash)) ||
  55         (pkt->size < sizeof(struct eth_header) + sizeof(struct vlan_header) +
  56         pkt->vnet_hdr_len)) {
  57         /*
  58          * The received remote packet maybe misconfiguration here,
  59          * Please enable/disable filter module's the vnet_hdr flag at
  60          * the same time.
  61          */
  62         trace_colo_proxy_main_vnet_info("This received packet load wrong ",
  63                                         pkt->vnet_hdr_len, pkt->size);
  64         return 1;
  65     }
  66     data += pkt->vnet_hdr_len;
  67
  68     l2hdr_len = eth_get_l2_hdr_length(data);
  69
  70     /*
  71      * TODO: support vlan.
  72      */
  73     if (!memcmp(&data[12], vlan, sizeof(vlan))) {
  74         trace_colo_proxy_main("COLO-proxy don't support vlan");
  75         return 1;
  76     }
  77
  78     pkt->network_header = data + l2hdr_len;
  79
  80     const struct iovec l2vec = {
  81         .iov_base = (void *) data,
  82         .iov_len = l2hdr_len
  83     };
  84     l3_proto = eth_get_l3_proto(&l2vec, 1, l2hdr_len);
  85
  86     if (l3_proto != ETH_P_IP) {
  87         return 1;
  88     }
  89
  90     network_length = pkt->ip->ip_hl * 4;
  91     if (pkt->size < l2hdr_len + network_length + pkt->vnet_hdr_len) {
  92         trace_colo_proxy_main("pkt->size < network_header + network_length");
  93         return 1;
  94     }
  95     pkt->transport_header = pkt->network_header + network_length;
  96
  97     return 0;
  98 }
  99
 100 void extract_ip_and_port(uint32_t tmp_ports, ConnectionKey *key,
 101                          Packet *pkt, bool reverse)
 102 {
 103     if (reverse) {
 104         key->src = pkt->ip->ip_dst;
 105         key->dst = pkt->ip->ip_src;
 106         key->src_port = ntohs(tmp_ports & 0xffff);
 107         key->dst_port = ntohs(tmp_ports >> 16);
 108     } else {
 109         key->src = pkt->ip->ip_src;
 110         key->dst = pkt->ip->ip_dst;
 111         key->src_port = ntohs(tmp_ports >> 16);
 112         key->dst_port = ntohs(tmp_ports & 0xffff);
 113     }
 114 }
 115
 116 void fill_connection_key(Packet *pkt, ConnectionKey *key, bool reverse)
 117 {
 118     uint32_t tmp_ports = 0;
 119
 120     key->ip_proto = pkt->ip->ip_p;
 121
 122     switch (key->ip_proto) {
 123     case IPPROTO_TCP:
 124     case IPPROTO_UDP:
 125     case IPPROTO_DCCP:
 126     case IPPROTO_ESP:
 127     case IPPROTO_SCTP:
 128     case IPPROTO_UDPLITE:
 129         tmp_ports = *(uint32_t *)(pkt->transport_header);
 130         break;
 131     case IPPROTO_AH:
 132         tmp_ports = *(uint32_t *)(pkt->transport_header + 4);
 133         break;
 134     default:
 135         break;
 136     }
 137
 138     extract_ip_and_port(tmp_ports, key, pkt, reverse);
 139 }
 140
 141 Connection *connection_new(ConnectionKey *key)
 142 {
 143     Connection *conn = g_slice_new0(Connection);
 144
 145     conn->ip_proto = key->ip_proto;
 146     conn->processing = false;
 147     conn->tcp_state = TCPS_CLOSED;
 148     g_queue_init(&conn->primary_list);
 149     g_queue_init(&conn->secondary_list);
 150
 151     return conn;
 152 }
 153
 154 void connection_destroy(void *opaque)
 155 {
 156     Connection *conn = opaque;
 157
 158     g_queue_foreach(&conn->primary_list, packet_destroy, NULL);
 159     g_queue_clear(&conn->primary_list);
 160     g_queue_foreach(&conn->secondary_list, packet_destroy, NULL);
 161     g_queue_clear(&conn->secondary_list);
 162     g_slice_free(Connection, conn);
 163 }
 164
 165 Packet *packet_new(const void *data, int size, int vnet_hdr_len)
 166 {
 167     Packet *pkt = g_slice_new0(Packet);
 168
 169     pkt->data = g_memdup(data, size);
 170     pkt->size = size;
 171     pkt->creation_ms = qemu_clock_get_ms(QEMU_CLOCK_HOST);
 172     pkt->vnet_hdr_len = vnet_hdr_len;
 173
 174     return pkt;
 175 }
 176
 177 /*
 178  * packet_new_nocopy will not copy data, so the caller can't release
 179  * the data. And it will be released in packet_destroy.
 180  */
 181 Packet *packet_new_nocopy(void *data, int size, int vnet_hdr_len)
 182 {
 183     Packet *pkt = g_slice_new0(Packet);
 184
 185     pkt->data = data;
 186     pkt->size = size;
 187     pkt->creation_ms = qemu_clock_get_ms(QEMU_CLOCK_HOST);
 188     pkt->vnet_hdr_len = vnet_hdr_len;
 189
 190     return pkt;
 191 }
 192
 193 void packet_destroy(void *opaque, void *user_data)
 194 {
 195     Packet *pkt = opaque;
 196
 197     g_free(pkt->data);
 198     g_slice_free(Packet, pkt);
 199 }
 200
 201 void packet_destroy_partial(void *opaque, void *user_data)
 202 {
 203     Packet *pkt = opaque;
 204
 205     g_slice_free(Packet, pkt);
 206 }
 207
 208 /*
 209  * Clear hashtable, stop this hash growing really huge
 210  */
 211 void connection_hashtable_reset(GHashTable *connection_track_table)
 212 {
 213     g_hash_table_remove_all(connection_track_table);
 214 }
 215
 216 /* if not found, create a new connection and add to hash table */
 217 Connection *connection_get(GHashTable *connection_track_table,
 218                            ConnectionKey *key,
 219                            GQueue *conn_list)
 220 {
 221     Connection *conn = g_hash_table_lookup(connection_track_table, key);
 222
 223     if (conn == NULL) {
 224         ConnectionKey *new_key = g_memdup(key, sizeof(*key));
 225
 226         conn = connection_new(key);
 227
 228         if (g_hash_table_size(connection_track_table) > HASHTABLE_MAX_SIZE) {
 229             trace_colo_proxy_main("colo proxy connection hashtable full,"
 230                                   " clear it");
 231             connection_hashtable_reset(connection_track_table);
 232             /*
 233              * clear the conn_list
 234              */
 235             while (conn_list && !g_queue_is_empty(conn_list)) {
 236                 connection_destroy(g_queue_pop_head(conn_list));
 237             }
 238         }
 239
 240         g_hash_table_insert(connection_track_table, new_key, conn);
 241     }
 242
 243     return conn;
 244 }
 245
 246 bool connection_has_tracked(GHashTable *connection_track_table,
 247                             ConnectionKey *key)
 248 {
 249     Connection *conn = g_hash_table_lookup(connection_track_table, key);
 250
 251     return conn ? true : false;
 252 }