/* packet-kdp.c
 * Routines for KDP (Kontiki Delivery Protocol) packet disassembly
 *
 * Copyright (c) 2008 by Kontiki Inc.
 *                    Wade Hennessey <wade@kontiki.com>
 *
 * Wireshark - Network traffic analyzer
 * By Gerald Combs <gerald@wireshark.org>
 * Copyright 1999 Gerald Combs
 *
 * SPDX-License-Identifier: GPL-2.0-or-later
 */

#include "config.h"

#include <epan/packet.h>
void proto_register_kdp(void);
void proto_reg_handoff_kdp(void);

#define KDP_PORT 19948 /* Not IANA registered */
#define BUFFER_SIZE 80
static int proto_kdp = -1;
static gint ett_kdp = -1;
static gint ett_kdp_flags = -1;

static int hf_kdp_version = -1;
static int hf_kdp_headerlen = -1;
static int hf_kdp_flags = -1;
static int hf_kdp_errors = -1;
static int hf_kdp_destflowid = -1;
static int hf_kdp_srcflowid = -1;
static int hf_kdp_sequence = -1;
static int hf_kdp_ack = -1;
static int hf_kdp_maxsegmentsize = -1;
static int hf_kdp_optionnumber = -1;
static int hf_kdp_optionlen = -1;
static int hf_kdp_option1 = -1;
static int hf_kdp_option2 = -1;
static int hf_kdp_option3 = -1;
static int hf_kdp_option4 = -1;
static int hf_kdp_option5 = -1;
static int hf_kdp_option6 = -1;
static int hf_kdp_option7 = -1;
static int hf_kdp_option8 = -1;
static int hf_kdp_option9 = -1;
static int hf_kdp_option_unknown = -1;
static int hf_kdp_fragment = -1;
static int hf_kdp_fragtotal = -1;
static int hf_kdp_body = -1;
static int hf_kdp_xml_body = -1;

#define KDP_DROP_FLAG (1 << 0)
#define KDP_SYN_FLAG  (1 << 1)
#define KDP_ACK_FLAG  (1 << 2)
#define KDP_RST_FLAG  (1 << 3)
#define KDP_BCST_FLAG (1 << 4)
#define KDP_DUP_FLAG  (1 << 5)

static int hf_kdp_drop_flag = -1;
static int hf_kdp_syn_flag = -1;
static int hf_kdp_ack_flag = -1;
static int hf_kdp_rst_flag = -1;
static int hf_kdp_bcst_flag = -1;
static int hf_kdp_dup_flag = -1;

static int dissect_kdp(tvbuff_t *tvb,
                        packet_info *pinfo,
                        proto_tree *tree, void* data _U_) {
  proto_item *ti;
  proto_tree *kdp_tree;
  guint body_len;
  guint8 version;
  guint8 header_len = 0;
  guint8 packet_flags = 0;
  guint8 packet_errors = 0;
  guint32 sequence_number = G_MAXUINT32;
  guint32 ack_number = G_MAXUINT32;
  guint32 src_flowid = G_MAXUINT32;

  col_set_str(pinfo->cinfo, COL_PROTOCOL, "KDP");
  col_clear(pinfo->cinfo, COL_INFO);

  ti = proto_tree_add_item(tree, proto_kdp, tvb, 0, -1, ENC_NA);
  kdp_tree = proto_item_add_subtree(ti, ett_kdp);

  version = tvb_get_guint8(tvb, 0);
  if (version != 2) {
    /* Version other than 2 is really SDDP in UDP */
    proto_tree_add_item(kdp_tree, hf_kdp_version, tvb, 0, 1, ENC_BIG_ENDIAN);
    proto_tree_add_item(kdp_tree, hf_kdp_xml_body, tvb, 0, -1, ENC_ASCII);
  } else {
    proto_tree *flags_tree;
    header_len = tvb_get_guint8(tvb, 1) * 4;
    body_len = tvb_reported_length(tvb);
    if (header_len > body_len) {
      body_len = 0;           /* malformed packet */
    } else {
      body_len = body_len - header_len;
    }
    packet_flags = tvb_get_guint8(tvb, 2);
    packet_errors = tvb_get_guint8(tvb, 3);
    proto_tree_add_item(kdp_tree, hf_kdp_version, tvb, 0, 1, ENC_BIG_ENDIAN);
    proto_tree_add_item(kdp_tree, hf_kdp_headerlen, tvb, 1, 1, ENC_BIG_ENDIAN);
    ti = proto_tree_add_item(kdp_tree, hf_kdp_flags, tvb, 2, 1, ENC_BIG_ENDIAN);
    flags_tree = proto_item_add_subtree(ti, ett_kdp_flags);

    proto_tree_add_item(flags_tree, hf_kdp_drop_flag, tvb, 2, 1, ENC_BIG_ENDIAN);
    proto_tree_add_item(flags_tree, hf_kdp_syn_flag, tvb, 2, 1, ENC_BIG_ENDIAN);
    proto_tree_add_item(flags_tree, hf_kdp_ack_flag, tvb, 2, 1, ENC_BIG_ENDIAN);
    proto_tree_add_item(flags_tree, hf_kdp_rst_flag, tvb, 2, 1, ENC_BIG_ENDIAN);
    proto_tree_add_item(flags_tree, hf_kdp_bcst_flag, tvb, 2, 1, ENC_BIG_ENDIAN);
    proto_tree_add_item(flags_tree, hf_kdp_dup_flag, tvb, 2, 1, ENC_BIG_ENDIAN);

    proto_tree_add_item(kdp_tree, hf_kdp_errors, tvb, 3, 1, ENC_BIG_ENDIAN);

    if (header_len > 4) {
      int offset;
      offset = 4;
      if (packet_flags & KDP_ACK_FLAG) {
        proto_tree_add_item(kdp_tree, hf_kdp_destflowid, tvb, offset, 4, ENC_BIG_ENDIAN);
        offset = offset + 4;
      }

      if (packet_flags & (KDP_SYN_FLAG | KDP_BCST_FLAG)) {
        proto_tree_add_item(kdp_tree, hf_kdp_srcflowid, tvb, offset, 4, ENC_BIG_ENDIAN);
        src_flowid = tvb_get_ntohl(tvb, offset);
        offset = offset + 4;
      }

      proto_tree_add_item(kdp_tree, hf_kdp_sequence, tvb, offset, 4, ENC_BIG_ENDIAN);
      sequence_number = tvb_get_ntohl(tvb, offset);
      offset = offset + 4;

      if (packet_flags & KDP_ACK_FLAG) {
        proto_tree_add_item(kdp_tree, hf_kdp_ack, tvb, offset, 4, ENC_BIG_ENDIAN);
        ack_number = tvb_get_ntohl(tvb, offset);
        offset = offset + 4;
      }
      if (packet_flags & KDP_SYN_FLAG) {
        proto_tree_add_item(kdp_tree, hf_kdp_maxsegmentsize, tvb, offset, 4, ENC_BIG_ENDIAN);
        offset = offset + 4;
      }

      while (offset < ((body_len > 0) ? header_len - 4 : header_len)) {
        guint8 option_number;
        guint8 option_len = 0;

        option_number = tvb_get_guint8(tvb, offset);

        proto_tree_add_item(kdp_tree, hf_kdp_optionnumber, tvb, offset, 1, ENC_BIG_ENDIAN);
        offset = offset + 1;
        if (option_number > 0) {
          option_len = tvb_get_guint8(tvb, offset);
          proto_tree_add_item(kdp_tree, hf_kdp_optionlen, tvb, offset, 1, ENC_BIG_ENDIAN);
          offset = offset + 1;
        }

        switch (option_number) {
        case 0:
          break;
        case 1:
          proto_tree_add_item(kdp_tree, hf_kdp_option1, tvb, offset, 2, ENC_BIG_ENDIAN);
          offset = offset + 2;
          break;
        case 2:
          proto_tree_add_item(kdp_tree, hf_kdp_option2, tvb, offset, 2, ENC_BIG_ENDIAN);
          offset = offset + 2;
          break;
        case 3:
          proto_tree_add_item(kdp_tree, hf_kdp_option3, tvb, offset, 2, ENC_BIG_ENDIAN);
          offset = offset + 2;
          break;
        case 4:
          proto_tree_add_item(kdp_tree, hf_kdp_option4, tvb, offset, 0, ENC_NA);
          break;
        case 5:
          proto_tree_add_item(kdp_tree, hf_kdp_option5, tvb, offset, 0, ENC_NA);
          break;
        case 6:
          proto_tree_add_item(kdp_tree, hf_kdp_option6, tvb, offset, option_len - 2, ENC_NA);
          offset = offset + option_len - 2;
          break;
        case 7:
          proto_tree_add_item(kdp_tree, hf_kdp_option7, tvb, offset, 2, ENC_BIG_ENDIAN);
          offset = offset + 2;
          break;
        case 8:
          proto_tree_add_item(kdp_tree, hf_kdp_option8, tvb, offset, 2, ENC_BIG_ENDIAN);
          offset = offset + 2;
          break;
        case 9:
          proto_tree_add_item(kdp_tree, hf_kdp_option9, tvb, offset, 2, ENC_BIG_ENDIAN);
          offset = offset + 2;
          break;
        default:
          proto_tree_add_item(kdp_tree, hf_kdp_option_unknown, tvb, offset, option_len - 2, ENC_NA);
          offset = offset + option_len - 2;
          break;
        }
      }

      if (body_len > 0) {
        proto_tree_add_item(kdp_tree, hf_kdp_fragment, tvb, offset, 2, ENC_BIG_ENDIAN);
        offset = offset + 2;

        proto_tree_add_item(kdp_tree, hf_kdp_fragtotal, tvb, offset, 2, ENC_BIG_ENDIAN);
        offset = offset + 2;

        proto_tree_add_item(kdp_tree, hf_kdp_body, tvb, offset, -1, ENC_NA);
      }
    }
  }
  /* Now that we know sequence number and optional ack number, we can
     print more detailed summary info */
  if (version != 2) {
      col_set_str(pinfo->cinfo, COL_INFO, "SDDP message");
  } else {
      char ack_string[BUFFER_SIZE];
      char seq_num_string[BUFFER_SIZE];
      char src_flowid_string[BUFFER_SIZE];

      if (packet_flags & KDP_ACK_FLAG) {
        snprintf(ack_string, sizeof(ack_string), "ACK=%x ", ack_number);
      } else {
        ack_string[0] = '\0';
      }
      if (header_len > 4) {
        snprintf(seq_num_string, sizeof(seq_num_string), "SEQ=%x ", sequence_number);
      } else {
        seq_num_string[0] = '\0';
      }
      if (packet_flags & (KDP_SYN_FLAG | KDP_BCST_FLAG)) {
        snprintf(src_flowid_string, sizeof(src_flowid_string), "SRC_FLOWID=%x ", src_flowid);
      } else {
        src_flowid_string[0] = '\0';
      }
      col_add_fstr(pinfo->cinfo, COL_INFO, "%s%s%s%s%s%s%s%serrors=%d",
                   ((packet_flags & KDP_DROP_FLAG) ? "DROP " : ""),
                   ((packet_flags & KDP_SYN_FLAG) ? "SYN " : ""),
                   ((packet_flags & KDP_RST_FLAG) ? "RST " : ""),
                   ((packet_flags & KDP_BCST_FLAG) ? "BCST " : ""),
                   ((packet_flags & KDP_DUP_FLAG) ? "DUP " : ""),
                   ack_string,
                   seq_num_string,
                   src_flowid_string,
                   packet_errors);
  }

  return tvb_captured_length(tvb);
}

void proto_register_kdp(void) {

  static hf_register_info hf[] = {
    { &hf_kdp_version,
      {"KDP version", "kdp.version",
       FT_UINT8, BASE_DEC, NULL, 0x0, NULL, HFILL}
    },
    { &hf_kdp_headerlen,
      {"KDP header len", "kdp.headerlen",
       FT_UINT8, BASE_DEC, NULL, 0x0, NULL, HFILL}
    },
    { &hf_kdp_flags,
      {"KDP flags", "kdp.flags",
       FT_UINT8, BASE_HEX, NULL, 0x0, NULL, HFILL}
    },
    { &hf_kdp_drop_flag,
      {"KDP DROP Flag", "kdp.flags.drop",
       FT_BOOLEAN, 8, NULL, KDP_DROP_FLAG, NULL, HFILL}
    },
    { &hf_kdp_syn_flag,
      {"KDP SYN Flag", "kdp.flags.syn",
       FT_BOOLEAN, 8, NULL, KDP_SYN_FLAG, NULL, HFILL}
    },
    { &hf_kdp_ack_flag,
      {"KDP ACK Flag", "kdp.flags.ack",
       FT_BOOLEAN, 8, NULL, KDP_ACK_FLAG, NULL, HFILL}
    },
    { &hf_kdp_rst_flag,
      {"KDP RST Flag", "kdp.flags.rst",
       FT_BOOLEAN, 8, NULL, KDP_RST_FLAG, NULL, HFILL}
    },
    { &hf_kdp_bcst_flag,
      {"KDP BCST Flag", "kdp.flags.bcst",
       FT_BOOLEAN, 8, NULL, KDP_BCST_FLAG, NULL, HFILL}
    },
    { &hf_kdp_dup_flag,
      {"KDP DUP Flag", "kdp.flags.dup",
       FT_BOOLEAN, 8, NULL, KDP_DUP_FLAG, NULL, HFILL}
    },
    { &hf_kdp_errors,
      {"KDP errors", "kdp.errors",
       FT_UINT8, BASE_DEC, NULL, 0x0, NULL, HFILL}
    },
    { &hf_kdp_destflowid,
      { "DestFlowID", "kdp.destflowid",
        FT_UINT32, BASE_HEX, NULL, 0x0, NULL, HFILL}
    },
    { &hf_kdp_srcflowid,
      { "SrcFlowID", "kdp.srcflowid",
        FT_UINT32, BASE_HEX, NULL, 0x0, NULL, HFILL}
    },
    { &hf_kdp_sequence,
      { "Sequence", "kdp.sequence",
        FT_UINT32, BASE_HEX, NULL, 0x0, NULL, HFILL}
    },
    { &hf_kdp_ack,
      { "Ack", "kdp.ack",
        FT_UINT32, BASE_HEX, NULL, 0x0, NULL, HFILL}
    },
    { &hf_kdp_maxsegmentsize,
      { "MaxSegmentSize", "kdp.maxsegmentsize",
        FT_UINT32, BASE_HEX, NULL, 0x0, NULL, HFILL}
    },
    { &hf_kdp_optionnumber,
      { "Option Number", "kdp.optionnumber",
        FT_UINT8, BASE_HEX, NULL, 0x0, NULL, HFILL}
    },
    { &hf_kdp_optionlen,
      { "Option Len", "kdp.option",
        FT_UINT8, BASE_HEX, NULL, 0x0, NULL, HFILL}
    },
    { &hf_kdp_option1,
      { "Option1 - Max Window", "kdp.option1",
        FT_UINT16, BASE_HEX, NULL, 0x0, NULL, HFILL}
    },
    { &hf_kdp_option2,
      { "Option2 - TCP Fraction", "kdp.option2",
        FT_UINT16, BASE_HEX, NULL, 0x0, NULL, HFILL}
    },
    { &hf_kdp_option3,
      { "Option3 - KDP Version", "kdp.option3",
        FT_UINT16, BASE_HEX, NULL, 0x0, NULL, HFILL}
    },
    { &hf_kdp_option4,
      { "Option4 - Enable Reliable", "kdp.option4",
        FT_NONE, BASE_NONE, NULL, 0x0, NULL, HFILL}
    },
    { &hf_kdp_option5,
      { "Option5 - Disable Reliable", "kdp.option5",
        FT_NONE, BASE_NONE, NULL, 0x0, NULL, HFILL}
    },
    { &hf_kdp_option6,
      { "Option6 - SACK", "kdp.option6",
        FT_BYTES, BASE_NONE, NULL, 0x0, NULL, HFILL}
    },
    { &hf_kdp_option7,
      { "Option7 - COS", "kdp.option7",
        FT_UINT16, BASE_HEX, NULL, 0x0, NULL, HFILL}
    },
    { &hf_kdp_option8,
      { "Option8 - BWMIN", "kdp.option8",
        FT_UINT16, BASE_HEX, NULL, 0x0, NULL, HFILL}
    },
    { &hf_kdp_option9,
      { "Option9 - INT", "kdp.option9",
        FT_UINT16, BASE_HEX, NULL, 0x0, NULL, HFILL}
    },
    { &hf_kdp_option_unknown,
      { "Unknown option", "kdp.option_unknown",
        FT_BYTES, BASE_NONE, NULL, 0x0, NULL, HFILL}
    },
    { &hf_kdp_fragment,
      { "Fragment", "kdp.fragment",
        FT_UINT16, BASE_HEX, NULL, 0x0, NULL, HFILL}
    },
    { &hf_kdp_fragtotal,
      { "FragTotal", "kdp.fragtotal",
        FT_UINT16, BASE_HEX, NULL, 0x0, NULL, HFILL}
    },
    { &hf_kdp_body,
      { "Encrypted Body", "kdp.body",
        FT_BYTES, BASE_NONE, NULL, 0x0, NULL, HFILL}
    },
    { &hf_kdp_xml_body,
      { "XML Body", "kdp.xml_body",
        FT_STRING, BASE_NONE, NULL, 0x0, NULL, HFILL}
    }
  };

  /* Setup protocol subtree array */
  static gint *ett[] = {
    &ett_kdp, &ett_kdp_flags
  };

  proto_kdp = proto_register_protocol("Kontiki Delivery Protocol", /* name */
                                      "KDP",            /* short name */
                                      "kdp");           /* abbrev */
  proto_register_field_array(proto_kdp, hf, array_length(hf));
  proto_register_subtree_array(ett, array_length(ett));
}

void
proto_reg_handoff_kdp(void) {
  dissector_handle_t kdp_handle;
  kdp_handle = create_dissector_handle(dissect_kdp, proto_kdp);
  dissector_add_uint_with_preference("udp.port", KDP_PORT, kdp_handle);
}

/*
 * Editor modelines  -  https://www.wireshark.org/tools/modelines.html
 *
 * Local Variables:
 * c-basic-offset: 2
 * tab-width: 8
 * indent-tabs-mode: nil
 * End:
 *
 * ex: set shiftwidth=2 tabstop=8 expandtab:
 * :indentSize=2:tabSize=8:noTabs=true:
 */
