qemu

colo.c (6720B)

---

 /*
  * 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 <zhangchen.fnst@cn.fujitsu.com>
  *
  * 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 "trace.h"
 #include "colo.h"
 #include "util.h"
 
 uint32_t connection_key_hash(const void *opaque)
 {
     const ConnectionKey *key = opaque;
     uint32_t a, b, c;
 
     /* Jenkins hash */
     a = b = c = JHASH_INITVAL + sizeof(*key);
     a += key->src.s_addr;
     b += key->dst.s_addr;
     c += (key->src_port | key->dst_port << 16);
     __jhash_mix(a, b, c);
 
     a += key->ip_proto;
     __jhash_final(a, b, c);
 
     return c;
 }
 
 int connection_key_equal(const void *key1, const void *key2)
 {
     return memcmp(key1, key2, sizeof(ConnectionKey)) == 0;
 }
 
 int parse_packet_early(Packet *pkt)
 {
     int network_length;
     static const uint8_t vlan[] = {0x81, 0x00};
     uint8_t *data = pkt->data;
     uint16_t l3_proto;
     ssize_t l2hdr_len;
 
     assert(data);
 
     /* Check the received vnet_hdr_len then add the offset */
     if ((pkt->vnet_hdr_len > sizeof(struct virtio_net_hdr_v1_hash)) ||
         (pkt->size < sizeof(struct eth_header) + sizeof(struct vlan_header) +
         pkt->vnet_hdr_len)) {
         /*
          * The received remote packet maybe misconfiguration here,
          * Please enable/disable filter module's the vnet_hdr flag at
          * the same time.
          */
         trace_colo_proxy_main_vnet_info("This received packet load wrong ",
                                         pkt->vnet_hdr_len, pkt->size);
         return 1;
     }
     data += pkt->vnet_hdr_len;
 
     l2hdr_len = eth_get_l2_hdr_length(data);
 
     /*
      * TODO: support vlan.
      */
     if (!memcmp(&data[12], vlan, sizeof(vlan))) {
         trace_colo_proxy_main("COLO-proxy don't support vlan");
         return 1;
     }
 
     pkt->network_header = data + l2hdr_len;
 
     const struct iovec l2vec = {
         .iov_base = (void *) data,
         .iov_len = l2hdr_len
     };
     l3_proto = eth_get_l3_proto(&l2vec, 1, l2hdr_len);
 
     if (l3_proto != ETH_P_IP) {
         return 1;
     }
 
     network_length = pkt->ip->ip_hl * 4;
     if (pkt->size < l2hdr_len + network_length + pkt->vnet_hdr_len) {
         trace_colo_proxy_main("pkt->size < network_header + network_length");
         return 1;
     }
     pkt->transport_header = pkt->network_header + network_length;
 
     return 0;
 }
 
 void extract_ip_and_port(uint32_t tmp_ports, ConnectionKey *key,
                          Packet *pkt, bool reverse)
 {
     if (reverse) {
         key->src = pkt->ip->ip_dst;
         key->dst = pkt->ip->ip_src;
         key->src_port = ntohs(tmp_ports & 0xffff);
         key->dst_port = ntohs(tmp_ports >> 16);
     } else {
         key->src = pkt->ip->ip_src;
         key->dst = pkt->ip->ip_dst;
         key->src_port = ntohs(tmp_ports >> 16);
         key->dst_port = ntohs(tmp_ports & 0xffff);
     }
 }
 
 void fill_connection_key(Packet *pkt, ConnectionKey *key, bool reverse)
 {
     uint32_t tmp_ports = 0;
 
     key->ip_proto = pkt->ip->ip_p;
 
     switch (key->ip_proto) {
     case IPPROTO_TCP:
     case IPPROTO_UDP:
     case IPPROTO_DCCP:
     case IPPROTO_ESP:
     case IPPROTO_SCTP:
     case IPPROTO_UDPLITE:
         tmp_ports = *(uint32_t *)(pkt->transport_header);
         break;
     case IPPROTO_AH:
         tmp_ports = *(uint32_t *)(pkt->transport_header + 4);
         break;
     default:
         break;
     }
 
     extract_ip_and_port(tmp_ports, key, pkt, reverse);
 }
 
 Connection *connection_new(ConnectionKey *key)
 {
     Connection *conn = g_slice_new0(Connection);
 
     conn->ip_proto = key->ip_proto;
     conn->processing = false;
     conn->tcp_state = TCPS_CLOSED;
     g_queue_init(&conn->primary_list);
     g_queue_init(&conn->secondary_list);
 
     return conn;
 }
 
 void connection_destroy(void *opaque)
 {
     Connection *conn = opaque;
 
     g_queue_foreach(&conn->primary_list, packet_destroy, NULL);
     g_queue_clear(&conn->primary_list);
     g_queue_foreach(&conn->secondary_list, packet_destroy, NULL);
     g_queue_clear(&conn->secondary_list);
     g_slice_free(Connection, conn);
 }
 
 Packet *packet_new(const void *data, int size, int vnet_hdr_len)
 {
     Packet *pkt = g_slice_new0(Packet);
 
     pkt->data = g_memdup(data, size);
     pkt->size = size;
     pkt->creation_ms = qemu_clock_get_ms(QEMU_CLOCK_HOST);
     pkt->vnet_hdr_len = vnet_hdr_len;
 
     return pkt;
 }
 
 /*
  * packet_new_nocopy will not copy data, so the caller can't release
  * the data. And it will be released in packet_destroy.
  */
 Packet *packet_new_nocopy(void *data, int size, int vnet_hdr_len)
 {
     Packet *pkt = g_slice_new0(Packet);
 
     pkt->data = data;
     pkt->size = size;
     pkt->creation_ms = qemu_clock_get_ms(QEMU_CLOCK_HOST);
     pkt->vnet_hdr_len = vnet_hdr_len;
 
     return pkt;
 }
 
 void packet_destroy(void *opaque, void *user_data)
 {
     Packet *pkt = opaque;
 
     g_free(pkt->data);
     g_slice_free(Packet, pkt);
 }
 
 void packet_destroy_partial(void *opaque, void *user_data)
 {
     Packet *pkt = opaque;
 
     g_slice_free(Packet, pkt);
 }
 
 /*
  * Clear hashtable, stop this hash growing really huge
  */
 void connection_hashtable_reset(GHashTable *connection_track_table)
 {
     g_hash_table_remove_all(connection_track_table);
 }
 
 /* if not found, create a new connection and add to hash table */
 Connection *connection_get(GHashTable *connection_track_table,
                            ConnectionKey *key,
                            GQueue *conn_list)
 {
     Connection *conn = g_hash_table_lookup(connection_track_table, key);
 
     if (conn == NULL) {
         ConnectionKey *new_key = g_memdup(key, sizeof(*key));
 
         conn = connection_new(key);
 
         if (g_hash_table_size(connection_track_table) > HASHTABLE_MAX_SIZE) {
             trace_colo_proxy_main("colo proxy connection hashtable full,"
                                   " clear it");
             connection_hashtable_reset(connection_track_table);
             /*
              * clear the conn_list
              */
             while (conn_list && !g_queue_is_empty(conn_list)) {
                 connection_destroy(g_queue_pop_head(conn_list));
             }
         }
 
         g_hash_table_insert(connection_track_table, new_key, conn);
     }
 
     return conn;
 }
 
 bool connection_has_tracked(GHashTable *connection_track_table,
                             ConnectionKey *key)
 {
     Connection *conn = g_hash_table_lookup(connection_track_table, key);
 
     return conn ? true : false;
 }