text: /* packet-ayiya.c
   * Anything in Anything protocol
   * Copyright 2008, Jelmer Vernooij <jelmer@samba.org>
   *
   * Wireshark - Network traffic analyzer
   * By Gerald Combs <gerald@wireshark.org>
   * Copyright 1998 Gerald Combs
   *
   * SPDX-License-Identifier: GPL-2.0-or-later
   *
   * ref: http://unfix.org/~jeroen/archive/drafts/draft-massar-v6ops-ayiya-02.html#anchor4
   */
  
  #include "config.h"
  
  #include <epan/packet.h>
  #include <epan/ipproto.h>
  
  void proto_register_ayiya(void);
  void proto_reg_handoff_ayiya(void);
  
  static dissector_table_t ip_dissector_table;
  
  static int proto_ayiya = -1;
  static int hf_id_len = -1;
  static int hf_id_type = -1;
  static int hf_sig_len = -1;
  static int hf_hash_method = -1;
  static int hf_auth_method = -1;
  static int hf_opcode = -1;
  static int hf_next_header = -1;
  static int hf_epoch = -1;
  static int hf_identity = -1;
  static int hf_signature = -1;
  
  static gint ett_ayiya = -1;
  
  static dissector_handle_t ayiya_handle = NULL;
  
  static const value_string identity_types[] = {
      { 0x0, "None" },
      { 0x1, "Integer" },
      { 0x2, "ASCII string" },
      { 0, NULL }
  };
  
  static const value_string hash_methods[] = {
      { 0x0, "No hash" },
      { 0x1, "MD5" },
      { 0x2, "SHA1" },
      { 0, NULL }
  };
  
  static const value_string auth_methods[] = {
      { 0x0, "No authentication" },
      { 0x1, "Hash using a Shared Secret" },
      { 0x2, "Hash using a public/private key method" },
      { 0, NULL }
  };
  
  #define OPCODE_FORWARD 1
  
  static const value_string opcodes[] = {
      { 0x0, "No Operation / Heartbeat" },
      { 0x1, "Forward" },
      { 0x2, "Echo Request" },
      { 0x3, "Echo Request and Forward" },
      { 0x4, "Echo Response" },
      { 0x5, "MOTD" },
      { 0x6, "Query Request" },
      { 0x7, "Query Response" },
      { 0, NULL }
  };
  
  #define UDP_PORT_AYIYA          5072
  
  static int
  dissect_ayiya(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void* data _U_)
  {
      proto_tree *ayiya_tree;
      int offset = 0;
      int idlen, siglen, ayiya_len;
      guint8 next_header, opcode;
      tvbuff_t *payload;
  
      idlen = 1 << tvb_get_bits8(tvb, 0, 4);
      siglen = tvb_get_bits8(tvb, 8, 4) * 4;
      opcode = tvb_get_bits8(tvb, 20, 4);
      next_header = tvb_get_guint8(tvb, 3);
  
      ayiya_len = 8+idlen+siglen;
  
      col_set_str(pinfo->cinfo, COL_PROTOCOL, "AYIYA");
  
      if (tree) {
          proto_item *ti;
          ti = proto_tree_add_protocol_format( tree, proto_ayiya, tvb,
                                               offset, ayiya_len, "AYIYA" );
          ayiya_tree = proto_item_add_subtree(ti, ett_ayiya);
  
          proto_tree_add_bits_item(ayiya_tree, hf_id_len, tvb, 0, 4, ENC_BIG_ENDIAN);
          proto_tree_add_bits_item(ayiya_tree, hf_id_type, tvb, 4, 4, ENC_BIG_ENDIAN);
          proto_tree_add_bits_item(ayiya_tree, hf_sig_len, tvb, 8, 4, ENC_BIG_ENDIAN);
          proto_tree_add_bits_item(ayiya_tree, hf_hash_method, tvb, 12, 4, ENC_BIG_ENDIAN);
          proto_tree_add_bits_item(ayiya_tree, hf_auth_method, tvb, 16, 4, ENC_BIG_ENDIAN);
          proto_tree_add_bits_item(ayiya_tree, hf_opcode, tvb, 20, 4, ENC_BIG_ENDIAN);
          proto_tree_add_uint_format_value(ayiya_tree, hf_next_header, tvb,
                                     3, 1, next_header,
                                     "%s (0x%02x)",
                                     ipprotostr(next_header), next_header);
          proto_tree_add_item(ayiya_tree, hf_epoch, tvb, 4, 4, ENC_TIME_SECS|ENC_BIG_ENDIAN);
          proto_tree_add_item(ayiya_tree, hf_identity, tvb, 8, idlen, ENC_NA);
          proto_tree_add_item(ayiya_tree, hf_signature, tvb, 8+idlen, siglen, ENC_NA);
      }
      offset = ayiya_len;
      switch (opcode) {
      case OPCODE_FORWARD:
          payload = tvb_new_subset_remaining(tvb, offset);
          dissector_try_uint(ip_dissector_table, next_header, payload, pinfo, tree);
          break;
      }
  
      return tvb_captured_length(tvb);
  }
  
  void
  proto_register_ayiya(void)
  {
      static hf_register_info hf[] = {
          { &hf_id_len,
            { "Identity field length", "ayiya.idlen", FT_UINT8,
              BASE_HEX, NULL, 0x0, NULL, HFILL
            }
          },
          { &hf_id_type,
            { "Identity field type", "ayiya.idtype", FT_UINT8,
              BASE_HEX, VALS(identity_types), 0x0, NULL, HFILL
            }
          },
          { &hf_sig_len,
            { "Signature Length", "ayiya.siglen", FT_UINT8,
              BASE_HEX, NULL, 0x0, NULL, HFILL
            }
          },
          { &hf_hash_method,
            { "Hash method", "ayiya.hashmethod", FT_UINT8,
              BASE_HEX, VALS(hash_methods), 0x0, NULL, HFILL
            }
          },
          { &hf_auth_method,
            { "Authentication method", "ayiya.authmethod", FT_UINT8,
              BASE_HEX, VALS(auth_methods), 0x0, NULL, HFILL
            }
          },
          { &hf_opcode,
            { "Operation Code", "ayiya.opcode", FT_UINT8,
              BASE_HEX, VALS(opcodes), 0x0, NULL, HFILL
            }
          },
          { &hf_next_header,
            { "Next Header", "ayiya.nextheader", FT_UINT8,
              BASE_HEX, NULL, 0x0, NULL, HFILL
            }
          },
          { &hf_epoch,
            { "Epoch", "ayiya.epoch", FT_ABSOLUTE_TIME,
              ABSOLUTE_TIME_LOCAL, NULL, 0x0, NULL, HFILL
            }
          },
          { &hf_identity,
            { "Identity", "ayiya.identity", FT_BYTES,
              BASE_NONE, NULL, 0x0, NULL, HFILL
            }
          },
          { &hf_signature,
            { "Signature", "ayiya.signature", FT_BYTES,
              BASE_NONE, NULL, 0x0, NULL, HFILL
            }
          },
      };
      static gint *ett[] = {
          &ett_ayiya,
      };
  
      proto_ayiya = proto_register_protocol("Anything in Anything Protocol",
                            "AYIYA", "ayiya");
      ayiya_handle = register_dissector("ayiya", dissect_ayiya, proto_ayiya);
      proto_register_field_array(proto_ayiya, hf, array_length(hf));
      proto_register_subtree_array(ett, array_length(ett));
  }
  
  void
  proto_reg_handoff_ayiya(void)
  {
      dissector_add_uint_with_preference("udp.port", UDP_PORT_AYIYA, ayiya_handle);
  
      ip_dissector_table = find_dissector_table("ip.proto");
  }
  
  /*
   * Editor modelines  -  http://www.wireshark.org/tools/modelines.html
   *
   * Local variables:
   * c-basic-offset: 4
   * tab-width: 8
   * indent-tabs-mode: nil
   * End:
   *
   * vi: set shiftwidth=4 tabstop=8 expandtab:
   * :indentSize=4:tabSize=8:noTabs=true:
   */
  