Re: [Qemu-devel] [RFC PATCH v2 08/10] net/colo-proxy: Handle packet and connection

[Dr. David Alan Gilbert]

* Zhang Chen (address@hidden) wrote:
> 
> 
> On 02/20/2016 04:04 AM, Dr. David Alan Gilbert wrote:
> >* Zhang Chen (address@hidden) wrote:
> >>From: zhangchen <address@hidden>
> >>
> >>In here we will handle ip packet and connection
> >>
> >>Signed-off-by: zhangchen <address@hidden>
> >>Signed-off-by: zhanghailiang <address@hidden>
> >>---
> >>  net/colo-proxy.c | 130 
> >> +++++++++++++++++++++++++++++++++++++++++++++++++++++++
> >>  1 file changed, 130 insertions(+)
> >>
> >>diff --git a/net/colo-proxy.c b/net/colo-proxy.c
> >>index 5e5c72e..06bab80 100644
> >>--- a/net/colo-proxy.c
> >>+++ b/net/colo-proxy.c
> >>@@ -167,11 +167,141 @@ static int connection_key_equal(const void *opaque1, 
> >>const void *opaque2)
> >>      return memcmp(opaque1, opaque2, sizeof(ConnectionKey)) == 0;
> >>  }
> >>+static void connection_destroy(void *opaque)
> >>+{
> >>+    Connection *conn = opaque;
> >>+
> >>+    g_queue_foreach(&conn->primary_list, packet_destroy, NULL);
> >>+    g_queue_free(&conn->primary_list);
> >>+    g_queue_foreach(&conn->secondary_list, packet_destroy, NULL);
> >Be careful about these lists and which threads access them;
> >I found I could occasionally trigger a seg fault as two
> >threads tried to manipulate them at once; I just put a 'list_lock'
> >in the connection, which seems to fix it, but I might have to be
> >more careful with deadlocks.
> 
> Thanks for your work to colo.
> and where can I  see your code for colo-proxy?
> maybe I need it to make my code better.

Here is my latest version; it seems to just about work; but very
much still working on it:

   https://github.com/orbitfp7/qemu/tree/orbit-wp4-colo-jan16
 with the wp4-colo-rdma-2016-02-23 tag.

Dave
> 
> >
> >>+    g_queue_free(&conn->secondary_list);
> >>+    g_slice_free(Connection, conn);
> >>+}
> >>+
> >>+static Connection *connection_new(ConnectionKey *key)
> >>+{
> >>+    Connection *conn = g_slice_new(Connection);
> >>+
> >>+    conn->ip_proto = key->ip_proto;
> >>+    conn->processing = false;
> >>+    g_queue_init(&conn->primary_list);
> >>+    g_queue_init(&conn->secondary_list);
> >>+
> >>+    return conn;
> >>+}
> >>+
> >>+/*
> >>+ * Clear hashtable, stop this hash growing really huge
> >>+ */
> >>+static void clear_connection_hashtable(COLOProxyState *s)
> >>+{
> >>+    s->hashtable_size = 0;
> >>+    g_hash_table_remove_all(colo_conn_hash);
> >>+    trace_colo_proxy("clear_connection_hashtable");
> >>+}
> >>+
> >>  bool colo_proxy_query_checkpoint(void)
> >>  {
> >>      return colo_do_checkpoint;
> >>  }
> >>+/* Return 0 on success, or return -1 if the pkt is corrupted */
> >>+static int parse_packet_early(Packet *pkt, ConnectionKey *key)
> >>+{
> >>+    int network_length;
> >>+    uint8_t *data = pkt->data;
> >>+    uint16_t l3_proto;
> >>+    uint32_t tmp_ports;
> >>+    ssize_t l2hdr_len = eth_get_l2_hdr_length(data);
> >>+
> >>+    pkt->network_layer = data + ETH_HLEN;
> >>+    l3_proto = eth_get_l3_proto(data, l2hdr_len);
> >>+    if (l3_proto != ETH_P_IP) {
> >>+        if (l3_proto == ETH_P_ARP) {
> >>+            return -1;
> >>+        }
> >>+        return 0;
> >>+    }
> >>+
> >>+    network_length = pkt->ip->ip_hl * 4;
> >>+    pkt->transport_layer = pkt->network_layer + network_length;
> >>+    key->ip_proto = pkt->ip->ip_p;
> >>+    key->src = pkt->ip->ip_src;
> >>+    key->dst = pkt->ip->ip_dst;
> >>+
> >>+    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_layer);
> >>+        key->src_port = tmp_ports & 0xffff;
> >>+        key->dst_port = tmp_ports >> 16;
> >These fields are not byteswapped; it makes it very confusing
> >when printing them for debug;  I added htons around every
> >reading of the ports from the packets.
> >
> >Dave
> 
> I will fix it in colo-compare module.
> 
> Thanks
> zhangchen
> 
> >>+        break;
> >>+    case IPPROTO_AH:
> >>+        tmp_ports = *(uint32_t *)(pkt->transport_layer + 4);
> >>+        key->src_port = tmp_ports & 0xffff;
> >>+        key->dst_port = tmp_ports >> 16;
> >>+        break;
> >>+    default:
> >>+        break;
> >>+    }
> >>+
> >>+    return 0;
> >>+}
> >>+
> >>+static Packet *packet_new(COLOProxyState *s, void *data,
> >>+                          int size, ConnectionKey *key, NetClientState 
> >>*sender)
> >>+{
> >>+    Packet *pkt = g_slice_new(Packet);
> >>+
> >>+    pkt->data = data;
> >>+    pkt->size = size;
> >>+    pkt->s = s;
> >>+    pkt->sender = sender;
> >>+
> >>+    if (parse_packet_early(pkt, key)) {
> >>+        packet_destroy(pkt, NULL);
> >>+        pkt = NULL;
> >>+    }
> >>+
> >>+    return pkt;
> >>+}
> >>+
> >>+static void packet_destroy(void *opaque, void *user_data)
> >>+{
> >>+    Packet *pkt = opaque;
> >>+    g_free(pkt->data);
> >>+    g_slice_free(Packet, pkt);
> >>+}
> >>+
> >>+/* if not found, creata a new connection and add to hash table */
> >>+static Connection *colo_proxy_get_conn(COLOProxyState *s,
> >>+            ConnectionKey *key)
> >>+{
> >>+    /* FIXME: protect colo_conn_hash */
> >>+    Connection *conn = g_hash_table_lookup(colo_conn_hash, key);
> >>+
> >>+    if (conn == NULL) {
> >>+        ConnectionKey *new_key = g_malloc(sizeof(*key));
> >>+
> >>+        conn = connection_new(key);
> >>+        memcpy(new_key, key, sizeof(*key));
> >>+
> >>+        s->hashtable_size++;
> >>+        if (s->hashtable_size > hashtable_max_size) {
> >>+            trace_colo_proxy("colo proxy connection hashtable full, clear 
> >>it");
> >>+            clear_connection_hashtable(s);
> >>+        } else {
> >>+            g_hash_table_insert(colo_conn_hash, new_key, conn);
> >>+        }
> >>+    }
> >>+
> >>+     return conn;
> >>+}
> >>+
> >>  static ssize_t colo_proxy_enqueue_primary_packet(NetFilterState *nf,
> >>                                           NetClientState *sender,
> >>                                           unsigned flags,
> >>-- 
> >>1.9.1
> >>
> >>
> >>
> >>
> >--
> >Dr. David Alan Gilbert / address@hidden / Manchester, UK
> >
> >
> >.
> >
> 
> -- 
> Thanks
> zhangchen
> 
> 
> 
--
Dr. David Alan Gilbert / address@hidden / Manchester, UK