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 "net/colo.h"
  18
  19 uint32_t connection_key_hash(const void *opaque)
  20 {
  21     const ConnectionKey *key = opaque;
  22     uint32_t a, b, c;
  23
  24     /* Jenkins hash */
  25     a = b = c = JHASH_INITVAL + sizeof(*key);
  26     a += key->src.s_addr;
  27     b += key->dst.s_addr;
  28     c += (key->src_port | key->dst_port << 16);
  29     __jhash_mix(a, b, c);
  30
  31     a += key->ip_proto;
  32     __jhash_final(a, b, c);
  33
  34     return c;
  35 }
  36
  37 int connection_key_equal(const void *key1, const void *key2)
  38 {
  39     return memcmp(key1, key2, sizeof(ConnectionKey)) == 0;
  40 }
  41
  42 int parse_packet_early(Packet *pkt)
  43 {
  44     int network_length;
  45     static const uint8_t vlan[] = {0x81, 0x00};
  46     uint8_t *data = pkt->data + pkt->vnet_hdr_len;
  47     uint16_t l3_proto;
  48     ssize_t l2hdr_len = eth_get_l2_hdr_length(data);
  49
  50     if (pkt->size < ETH_HLEN + pkt->vnet_hdr_len) {
  51         trace_colo_proxy_main("pkt->size < ETH_HLEN");
  52         return 1;
  53     }
  54
  55     /*
  56      * TODO: support vlan.
  57      */
  58     if (!memcmp(&data[12], vlan, sizeof(vlan))) {
  59         trace_colo_proxy_main("COLO-proxy don't support vlan");
  60         return 1;
  61     }
  62
  63     pkt->network_header = data + l2hdr_len;
  64
  65     const struct iovec l2vec = {
  66         .iov_base = (void *) data,
  67         .iov_len = l2hdr_len
  68     };
  69     l3_proto = eth_get_l3_proto(&l2vec, 1, l2hdr_len);
  70
  71     if (l3_proto != ETH_P_IP) {
  72         return 1;
  73     }
  74
  75     network_length = pkt->ip->ip_hl * 4;
  76     if (pkt->size < l2hdr_len + network_length + pkt->vnet_hdr_len) {
  77         trace_colo_proxy_main("pkt->size < network_header + network_length");
  78         return 1;
  79     }
  80     pkt->transport_header = pkt->network_header + network_length;
  81
  82     return 0;
  83 }
  84
  85 void extract_ip_and_port(uint32_t tmp_ports, ConnectionKey *key, Packet *pkt)
  86 {
  87         key->src = pkt->ip->ip_src;
  88         key->dst = pkt->ip->ip_dst;
  89         key->src_port = ntohs(tmp_ports >> 16);
  90         key->dst_port = ntohs(tmp_ports & 0xffff);
  91 }
  92
  93 void fill_connection_key(Packet *pkt, ConnectionKey *key)
  94 {
  95     uint32_t tmp_ports;
  96
  97     memset(key, 0, sizeof(*key));
  98     key->ip_proto = pkt->ip->ip_p;
  99
 100     switch (key->ip_proto) {
 101     case IPPROTO_TCP:
 102     case IPPROTO_UDP:
 103     case IPPROTO_DCCP:
 104     case IPPROTO_ESP:
 105     case IPPROTO_SCTP:
 106     case IPPROTO_UDPLITE:
 107         tmp_ports = *(uint32_t *)(pkt->transport_header);
 108         extract_ip_and_port(tmp_ports, key, pkt);
 109         break;
 110     case IPPROTO_AH:
 111         tmp_ports = *(uint32_t *)(pkt->transport_header + 4);
 112         extract_ip_and_port(tmp_ports, key, pkt);
 113         break;
 114     default:
 115         break;
 116     }
 117 }
 118
 119 void reverse_connection_key(ConnectionKey *key)
 120 {
 121     struct in_addr tmp_ip;
 122     uint16_t tmp_port;
 123
 124     tmp_ip = key->src;
 125     key->src = key->dst;
 126     key->dst = tmp_ip;
 127
 128     tmp_port = key->src_port;
 129     key->src_port = key->dst_port;
 130     key->dst_port = tmp_port;
 131 }
 132
 133 Connection *connection_new(ConnectionKey *key)
 134 {
 135     Connection *conn = g_slice_new(Connection);
 136
 137     conn->ip_proto = key->ip_proto;
 138     conn->processing = false;
 139     conn->offset = 0;
 140     conn->syn_flag = 0;
 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_new(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 void packet_destroy(void *opaque, void *user_data)
 171 {
 172     Packet *pkt = opaque;
 173
 174     g_free(pkt->data);
 175     g_slice_free(Packet, pkt);
 176 }
 177
 178 /*
 179  * Clear hashtable, stop this hash growing really huge
 180  */
 181 void connection_hashtable_reset(GHashTable *connection_track_table)
 182 {
 183     g_hash_table_remove_all(connection_track_table);
 184 }
 185
 186 /* if not found, create a new connection and add to hash table */
 187 Connection *connection_get(GHashTable *connection_track_table,
 188                            ConnectionKey *key,
 189                            GQueue *conn_list)
 190 {
 191     Connection *conn = g_hash_table_lookup(connection_track_table, key);
 192
 193     if (conn == NULL) {
 194         ConnectionKey *new_key = g_memdup(key, sizeof(*key));
 195
 196         conn = connection_new(key);
 197
 198         if (g_hash_table_size(connection_track_table) > HASHTABLE_MAX_SIZE) {
 199             trace_colo_proxy_main("colo proxy connection hashtable full,"
 200                                   " clear it");
 201             connection_hashtable_reset(connection_track_table);
 202             /*
 203              * clear the conn_list
 204              */
 205             while (!g_queue_is_empty(conn_list)) {
 206                 connection_destroy(g_queue_pop_head(conn_list));
 207             }
 208         }
 209
 210         g_hash_table_insert(connection_track_table, new_key, conn);
 211     }
 212
 213     return conn;
 214 }