net/filter-rewriter.c

   1 /*
   2  * Copyright (c) 2016 HUAWEI TECHNOLOGIES CO., LTD.
   3  * Copyright (c) 2016 FUJITSU LIMITED
   4  * Copyright (c) 2016 Intel Corporation
   5  *
   6  * Author: Zhang Chen <zhangchen.fnst@cn.fujitsu.com>
   7  *
   8  * This work is licensed under the terms of the GNU GPL, version 2 or
   9  * later.  See the COPYING file in the top-level directory.
  10  */
  11
  12 #include "qemu/osdep.h"
  13 #include "net/colo.h"
  14 #include "net/filter.h"
  15 #include "net/net.h"
  16 #include "qemu-common.h"
  17 #include "qapi/error.h"
  18 #include "qapi/qmp/qerror.h"
  19 #include "qapi-visit.h"
  20 #include "qom/object.h"
  21 #include "qemu/main-loop.h"
  22 #include "qemu/iov.h"
  23 #include "net/checksum.h"
  24
  25 #define FILTER_COLO_REWRITER(obj) \
  26     OBJECT_CHECK(RewriterState, (obj), TYPE_FILTER_REWRITER)
  27
  28 #define TYPE_FILTER_REWRITER "filter-rewriter"
  29
  30 typedef struct RewriterState {
  31     NetFilterState parent_obj;
  32     NetQueue *incoming_queue;
  33     /* hashtable to save connection */
  34     GHashTable *connection_track_table;
  35 } RewriterState;
  36
  37 static void filter_rewriter_flush(NetFilterState *nf)
  38 {
  39     RewriterState *s = FILTER_COLO_REWRITER(nf);
  40
  41     if (!qemu_net_queue_flush(s->incoming_queue)) {
  42         /* Unable to empty the queue, purge remaining packets */
  43         qemu_net_queue_purge(s->incoming_queue, nf->netdev);
  44     }
  45 }
  46
  47 static ssize_t colo_rewriter_receive_iov(NetFilterState *nf,
  48                                          NetClientState *sender,
  49                                          unsigned flags,
  50                                          const struct iovec *iov,
  51                                          int iovcnt,
  52                                          NetPacketSent *sent_cb)
  53 {
  54     /*
  55      * if we get tcp packet
  56      * we will rewrite it to make secondary guest's
  57      * connection established successfully
  58      */
  59     return 0;
  60 }
  61
  62 static void colo_rewriter_cleanup(NetFilterState *nf)
  63 {
  64     RewriterState *s = FILTER_COLO_REWRITER(nf);
  65
  66     /* flush packets */
  67     if (s->incoming_queue) {
  68         filter_rewriter_flush(nf);
  69         g_free(s->incoming_queue);
  70     }
  71 }
  72
  73 static void colo_rewriter_setup(NetFilterState *nf, Error **errp)
  74 {
  75     RewriterState *s = FILTER_COLO_REWRITER(nf);
  76
  77     s->connection_track_table = g_hash_table_new_full(connection_key_hash,
  78                                                       connection_key_equal,
  79                                                       g_free,
  80                                                       connection_destroy);
  81     s->incoming_queue = qemu_new_net_queue(qemu_netfilter_pass_to_next, nf);
  82 }
  83
  84 static void colo_rewriter_class_init(ObjectClass *oc, void *data)
  85 {
  86     NetFilterClass *nfc = NETFILTER_CLASS(oc);
  87
  88     nfc->setup = colo_rewriter_setup;
  89     nfc->cleanup = colo_rewriter_cleanup;
  90     nfc->receive_iov = colo_rewriter_receive_iov;
  91 }
  92
  93 static const TypeInfo colo_rewriter_info = {
  94     .name = TYPE_FILTER_REWRITER,
  95     .parent = TYPE_NETFILTER,
  96     .class_init = colo_rewriter_class_init,
  97     .instance_size = sizeof(RewriterState),
  98 };
  99
 100 static void register_types(void)
 101 {
 102     type_register_static(&colo_rewriter_info);
 103 }
 104
 105 type_init(register_types);