Commit afe46124 authored by Zhang Chen's avatar Zhang Chen Committed by Jason Wang
Browse files

filter-rewriter: track connection and parse packet 



We use net/colo.h to track connection and parse packet

Signed-off-by: default avatarZhang Chen <zhangchen.fnst@cn.fujitsu.com>
Signed-off-by: default avatarLi Zhijian <lizhijian@cn.fujitsu.com>
Signed-off-by: default avatarWen Congyang <wency@cn.fujitsu.com>
Signed-off-by: default avatarJason Wang <jasowang@redhat.com>
parent e6eee8ab

net/colo.c

+14 −0
Original line number Diff line number Diff line
@@ -114,6 +114,20 @@ void fill_connection_key(Packet *pkt, ConnectionKey *key) 
    }

}



void reverse_connection_key(ConnectionKey *key)

{

    struct in_addr tmp_ip;

    uint16_t tmp_port;



    tmp_ip = key->src;

    key->src = key->dst;

    key->dst = tmp_ip;



    tmp_port = key->src_port;

    key->src_port = key->dst_port;

    key->dst_port = tmp_port;

}



Connection *connection_new(ConnectionKey *key)

{

    Connection *conn = g_slice_new(Connection);

net/colo.h

+1 −0
Original line number Diff line number Diff line
@@ -68,6 +68,7 @@ uint32_t connection_key_hash(const void *opaque); 
int connection_key_equal(const void *opaque1, const void *opaque2);

int parse_packet_early(Packet *pkt);

void fill_connection_key(Packet *pkt, ConnectionKey *key);

void reverse_connection_key(ConnectionKey *key);

Connection *connection_new(ConnectionKey *key);

void connection_destroy(void *opaque);

Connection *connection_get(GHashTable *connection_track_table,

net/filter-rewriter.c

+50 −0
Original line number Diff line number Diff line
@@ -44,6 +44,20 @@ static void filter_rewriter_flush(NetFilterState *nf) 
    }

}



/*

 * Return 1 on success, if return 0 means the pkt

 * is not TCP packet

 */

static int is_tcp_packet(Packet *pkt)

{

    if (!parse_packet_early(pkt) &&

        pkt->ip->ip_p == IPPROTO_TCP) {

        return 1;

    } else {

        return 0;

    }

}



static ssize_t colo_rewriter_receive_iov(NetFilterState *nf,

                                         NetClientState *sender,

                                         unsigned flags,
@@ -51,11 +65,47 @@ static ssize_t colo_rewriter_receive_iov(NetFilterState *nf, 
                                         int iovcnt,

                                         NetPacketSent *sent_cb)

{

    RewriterState *s = FILTER_COLO_REWRITER(nf);

    Connection *conn;

    ConnectionKey key;

    Packet *pkt;

    ssize_t size = iov_size(iov, iovcnt);

    char *buf = g_malloc0(size);



    iov_to_buf(iov, iovcnt, 0, buf, size);

    pkt = packet_new(buf, size);



    /*

     * if we get tcp packet

     * we will rewrite it to make secondary guest's

     * connection established successfully

     */

    if (pkt && is_tcp_packet(pkt)) {



        fill_connection_key(pkt, &key);



        if (sender == nf->netdev) {

            /*

             * We need make tcp TX and RX packet

             * into one connection.

             */

            reverse_connection_key(&key);

        }

        conn = connection_get(s->connection_track_table,

                              &key,

                              NULL);



        if (sender == nf->netdev) {

            /* NET_FILTER_DIRECTION_TX */

            /* handle_primary_tcp_pkt */

        } else {

            /* NET_FILTER_DIRECTION_RX */

            /* handle_secondary_tcp_pkt */

        }

    }



    packet_destroy(pkt, NULL);

    pkt = NULL;

    return 0;

}