epan/dissectors/packet-vxlan.c

   1 /* packet-vxlan.c
   2  *
   3  * Routines for Virtual eXtensible Local Area Network (VXLAN) packet dissection
   4  * RFC 7348 plus draft-smith-vxlan-group-policy-01
   5  *
   6  * (c) Copyright 2016, Sumit Kumar Jha <sjha3@ncsu.edu>
   7  * Support for VXLAN GPE (https://datatracker.ietf.org/doc/html/draft-ietf-nvo3-vxlan-gpe-02)
   8  *
   9  * Wireshark - Network traffic analyzer
  10  * By Gerald Combs <gerald@wireshark.org>
  11  * Copyright 1998 Gerald Combs
  12  *
  13  * SPDX-License-Identifier: GPL-2.0-or-later
  14  */
  15
  16 #include "config.h"
  17
  18 #include <epan/packet.h>
  19 #include <epan/tfs.h>
  20 #include "packet-vxlan.h"
  21
  22 #define UDP_PORT_VXLAN  "4789,8472" /* The IANA assigned port is 4789, but Linux default is 8472 for compatibility with early adopters */
  23 #define UDP_PORT_VXLAN_GPE  4790
  24
  25 void proto_register_vxlan(void);
  26 void proto_reg_handoff_vxlan(void);
  27
  28 static dissector_handle_t vxlan_handle;
  29 static dissector_handle_t vxlan_gpe_handle;
  30
  31 static int proto_vxlan;
  32 static int proto_vxlan_gpe;
  33
  34 static int hf_vxlan_flags;
  35 static int hf_vxlan_gpe_flags;
  36 static int hf_vxlan_flags_reserved;
  37 static int hf_vxlan_reserved_8;
  38 static int hf_vxlan_flag_a;
  39 static int hf_vxlan_flag_d;
  40 static int hf_vxlan_flag_i;
  41 static int hf_vxlan_flag_g;
  42 static int hf_vxlan_gbp;
  43 static int hf_vxlan_vni;
  44 static int hf_vxlan_gpe_flag_i;
  45 static int hf_vxlan_gpe_flag_p;
  46 static int hf_vxlan_gpe_flag_o;
  47 static int hf_vxlan_gpe_flag_ver;
  48 static int hf_vxlan_gpe_flag_reserved;
  49 static int hf_vxlan_gpe_reserved_16;
  50 static int hf_vxlan_next_proto;
  51 static int ett_vxlan;
  52 static int ett_vxlan_flags;
  53
  54 static int * const flags_fields[] = {
  55         &hf_vxlan_flag_g,
  56         &hf_vxlan_flag_i,
  57         &hf_vxlan_flag_d,
  58         &hf_vxlan_flag_a,
  59         &hf_vxlan_flags_reserved,
  60         NULL
  61     };
  62
  63 static int * const gpe_flags_fields[] = {
  64         &hf_vxlan_gpe_flag_ver,
  65         &hf_vxlan_gpe_flag_i,
  66         &hf_vxlan_gpe_flag_p,
  67         &hf_vxlan_gpe_flag_o,
  68         &hf_vxlan_gpe_flag_reserved,
  69         NULL
  70
  71    };
  72
  73 static const value_string vxlan_next_protocols[] = {
  74         { VXLAN_IPV4, "IPv4" },
  75         { VXLAN_IPV6, "IPv6" },
  76         { VXLAN_ETHERNET, "Ethernet" },
  77         { VXLAN_NSH, "Network Service Header" },
  78         { VXLAN_MPLS, "MPLS"},
  79         { 0, NULL }
  80  };
  81
  82 static dissector_handle_t eth_handle;
  83 static dissector_table_t vxlan_dissector_table;
  84
  85 static int
  86 dissect_vxlan_common(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, int is_gpe)
  87 {
  88     proto_tree *vxlan_tree;
  89     proto_item *ti;
  90     tvbuff_t *next_tvb;
  91     int offset = 0;
  92     uint32_t vxlan_next_proto;
  93
  94     col_set_str(pinfo->cinfo, COL_PROTOCOL, "VxLAN");
  95     col_clear(pinfo->cinfo, COL_INFO);
  96
  97
  98     ti = proto_tree_add_item(tree, proto_vxlan, tvb, offset, 8, ENC_NA);
  99     vxlan_tree = proto_item_add_subtree(ti, ett_vxlan);
 100
 101     if(is_gpe) {
 102         proto_tree_add_bitmask(vxlan_tree, tvb, offset, hf_vxlan_gpe_flags, ett_vxlan_flags, gpe_flags_fields, ENC_BIG_ENDIAN);
 103         offset += 1;
 104
 105         proto_tree_add_item(vxlan_tree, hf_vxlan_gpe_reserved_16, tvb, offset, 2, ENC_BIG_ENDIAN);
 106         offset += 2;
 107
 108         proto_tree_add_item_ret_uint(vxlan_tree, hf_vxlan_next_proto, tvb, offset, 1, ENC_BIG_ENDIAN, &vxlan_next_proto);
 109         offset += 1;
 110     } else {
 111         proto_tree_add_bitmask(vxlan_tree, tvb, offset, hf_vxlan_flags, ett_vxlan_flags, flags_fields, ENC_BIG_ENDIAN);
 112         offset += 2;
 113
 114         proto_tree_add_item(vxlan_tree, hf_vxlan_gbp, tvb, offset, 2, ENC_BIG_ENDIAN);
 115         offset += 2;
 116     }
 117
 118     proto_tree_add_item(vxlan_tree, hf_vxlan_vni, tvb, offset, 3, ENC_BIG_ENDIAN);
 119     offset += 3;
 120
 121     proto_tree_add_item(vxlan_tree, hf_vxlan_reserved_8, tvb, offset, 1, ENC_BIG_ENDIAN);
 122     offset += 1;
 123
 124     next_tvb = tvb_new_subset_remaining(tvb, offset);
 125
 126     if(is_gpe){
 127         if(!dissector_try_uint(vxlan_dissector_table, vxlan_next_proto, next_tvb, pinfo, tree)) {
 128             call_data_dissector(next_tvb, pinfo, tree);
 129         }
 130     } else {
 131         call_dissector(eth_handle, next_tvb, pinfo, tree);
 132     }
 133
 134     return tvb_captured_length(tvb);
 135 }
 136
 137 static int
 138 dissect_vxlan_gpe(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void* data _U_)
 139 {
 140     return dissect_vxlan_common(tvb, pinfo, tree, true);
 141 }
 142
 143
 144 static int
 145 dissect_vxlan(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void* data _U_)
 146 {
 147     return dissect_vxlan_common(tvb, pinfo, tree, false);
 148 }
 149
 150
 151
 152
 153 /* Register VxLAN with Wireshark */
 154 void
 155 proto_register_vxlan(void)
 156 {
 157     static hf_register_info hf[] = {
 158         { &hf_vxlan_flags,
 159           { "Flags", "vxlan.flags",
 160             FT_UINT16, BASE_HEX, NULL, 0x00,
 161             NULL, HFILL
 162           },
 163         },
 164         { &hf_vxlan_gpe_flags,
 165           { "Flags", "vxlan.flags",
 166             FT_UINT8, BASE_HEX, NULL, 0x00,
 167             NULL, HFILL
 168           },
 169         },
 170         { &hf_vxlan_flags_reserved,
 171           { "Reserved(R)", "vxlan.flags_reserved",
 172             FT_UINT16, BASE_HEX, NULL, 0x77b7,
 173             NULL, HFILL,
 174           },
 175         },
 176         { &hf_vxlan_gpe_flag_reserved,
 177           { "Reserved(R)", "vxlan.flags_reserved",
 178             FT_UINT8, BASE_DEC, NULL, 0xC2,
 179             NULL, HFILL,
 180           },
 181         },
 182         { &hf_vxlan_flag_g,
 183           { "GBP Extension", "vxlan.flag_g",
 184             FT_BOOLEAN, 16, TFS(&tfs_defined_not_defined), 0x8000,
 185             NULL, HFILL,
 186           },
 187         },
 188         { &hf_vxlan_flag_i,
 189           { "VXLAN Network ID (VNI)", "vxlan.flag_i",
 190             FT_BOOLEAN, 16, NULL, 0x0800,
 191             NULL, HFILL,
 192           },
 193         },
 194         { &hf_vxlan_flag_d,
 195           { "Don't Learn", "vxlan.flag_d",
 196             FT_BOOLEAN, 16, NULL, 0x0040,
 197             NULL, HFILL,
 198           },
 199         },
 200         { &hf_vxlan_flag_a,
 201           { "Policy Applied", "vxlan.flag_a",
 202             FT_BOOLEAN, 16, NULL, 0x0008,
 203             NULL, HFILL,
 204           },
 205         },
 206         { &hf_vxlan_gpe_flag_ver,
 207           { "Version", "vxlan.ver",
 208             FT_UINT8, BASE_DEC, NULL, 0x30,
 209             NULL, HFILL,
 210           },
 211         },
 212         { &hf_vxlan_gpe_flag_i,
 213           { "Instance", "vxlan.i_bit",
 214             FT_UINT8, BASE_DEC, NULL, 0x08,
 215             NULL, HFILL,
 216           },
 217         },
 218         { &hf_vxlan_gpe_flag_p,
 219           { "Next Protocol Bit", "vxlan.p_bit",
 220             FT_UINT8, BASE_DEC, NULL, 0x04,
 221             NULL, HFILL,
 222           },
 223         },
 224         { &hf_vxlan_gpe_flag_o,
 225           { "OAM bit", "vxlan.o_bit",
 226             FT_UINT8, BASE_DEC, NULL, 0x01,
 227             NULL, HFILL,
 228           },
 229         },
 230         { &hf_vxlan_gbp,
 231           { "Group Policy ID", "vxlan.gbp",
 232             FT_UINT16, BASE_DEC, NULL, 0x0,
 233             NULL, HFILL
 234           },
 235         },
 236         { &hf_vxlan_vni,
 237           { "VXLAN Network Identifier (VNI)", "vxlan.vni",
 238             FT_UINT24, BASE_DEC, NULL, 0x0,
 239             NULL, HFILL
 240           },
 241         },
 242         { &hf_vxlan_reserved_8,
 243           { "Reserved", "vxlan.reserved8",
 244             FT_UINT8, BASE_DEC, NULL, 0x0,
 245             NULL, HFILL
 246           },
 247         },
 248         { &hf_vxlan_gpe_reserved_16,
 249           { "Reserved", "vxlan.reserved_16",
 250             FT_UINT16, BASE_DEC, NULL, 0x0,
 251             NULL, HFILL
 252           },
 253         },
 254         { &hf_vxlan_next_proto,
 255           { "Next Protocol", "vxlan.next_proto",
 256             FT_UINT8, BASE_DEC, VALS(vxlan_next_protocols), 0x0,
 257             NULL, HFILL
 258           },
 259         },
 260     };
 261
 262     /* Setup protocol subtree array */
 263     static int *ett[] = {
 264         &ett_vxlan,
 265         &ett_vxlan_flags,
 266     };
 267
 268     /* Register the protocol name and description */
 269     proto_vxlan = proto_register_protocol("Virtual eXtensible Local Area Network", "VXLAN", "vxlan");
 270
 271     /* Protocol registered just for Decode As */
 272     proto_vxlan_gpe = proto_register_protocol_in_name_only("Virtual eXtensible Local Area Network (GPE)", "VXLAN (GPE)", "vxlan_gpe", proto_vxlan, FT_PROTOCOL);
 273
 274     /* Required function calls to register the header fields and subtrees used */
 275     proto_register_field_array(proto_vxlan, hf, array_length(hf));
 276     proto_register_subtree_array(ett, array_length(ett));
 277     vxlan_dissector_table = register_dissector_table("vxlan.next_proto", "VXLAN Next Protocol", proto_vxlan, FT_UINT8, BASE_DEC);
 278
 279     /* Register dissector handles */
 280     vxlan_handle = register_dissector("vxlan", dissect_vxlan, proto_vxlan);
 281     vxlan_gpe_handle = register_dissector("vxlan_gpe", dissect_vxlan_gpe, proto_vxlan_gpe);
 282 }
 283
 284 void
 285 proto_reg_handoff_vxlan(void)
 286 {
 287     /*
 288      * RFC 7348 Figures 1 and 2, in the Payload section, say
 289      *
 290      * "(Note that the original Ethernet Frame's FCS is not included)"
 291      *
 292      * meaning that the inner Ethernet frame does *not* include an
 293      * FCS.
 294      */
 295     eth_handle = find_dissector_add_dependency("eth_withoutfcs", proto_vxlan);
 296
 297     dissector_add_uint_range_with_preference("udp.port", UDP_PORT_VXLAN, vxlan_handle);
 298     dissector_add_uint_with_preference("udp.port", UDP_PORT_VXLAN_GPE, vxlan_gpe_handle);
 299 }
 300
 301 /*
 302  * Editor modelines  -  https://www.wireshark.org/tools/modelines.html
 303  *
 304  * Local variables:
 305  * c-basic-offset: 4
 306  * tab-width: 8
 307  * indent-tabs-mode: nil
 308  * End:
 309  *
 310  * vi: set shiftwidth=4 tabstop=8 expandtab:
 311  * :indentSize=4:tabSize=8:noTabs=true:
 312  */