/*

  id.c

  Author: Pekka Riikonen <priikone@silcnet.org>

  Copyright (C) 1997 - 2007 Pekka Riikonen

  This program is free software; you can redistribute it and/or modify
  it under the terms of the GNU General Public License as published by
  the Free Software Foundation; version 2 of the License.

  This program is distributed in the hope that it will be useful,
  but WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  GNU General Public License for more details.

*/
/* $Id$ */

#include "silc.h"
#include "silcid.h"

/* ID lengths (in bytes) without the IP address part */
#define ID_SERVER_LEN_PART      4
#define ID_CLIENT_LEN_PART      CLIENTID_HASH_LEN + 1
#define ID_CHANNEL_LEN_PART     4

/******************************************************************************

                                ID Payload

******************************************************************************/

struct SilcIDPayloadStruct {
  SilcIdType type;
  SilcUInt16 len;
  unsigned char *id;
};

/* Parses buffer and return ID payload into payload structure */

SilcIDPayload silc_id_payload_parse(const unsigned char *payload,
				    SilcUInt32 payload_len)
{
  SilcBufferStruct buffer;
  SilcIDPayload newp;
  int ret;

  silc_buffer_set(&buffer, (unsigned char *)payload, payload_len);
  newp = silc_calloc(1, sizeof(*newp));
  if (!newp)
    return NULL;

  ret = silc_buffer_unformat(&buffer,
			     SILC_STR_UI_SHORT(&newp->type),
			     SILC_STR_UI_SHORT(&newp->len),
			     SILC_STR_END);
  if (ret == -1)
    goto err;

  if (newp->type > SILC_ID_CHANNEL)
    goto err;

  silc_buffer_pull(&buffer, 4);

  if (newp->len > silc_buffer_len(&buffer) ||
      newp->len > SILC_PACKET_MAX_ID_LEN)
    goto err;

  ret = silc_buffer_unformat(&buffer,
			     SILC_STR_DATA_ALLOC(&newp->id, newp->len),
			     SILC_STR_END);
  if (ret == -1)
    goto err;

  return newp;

 err:
  SILC_LOG_DEBUG(("Error parsing ID payload"));
  silc_free(newp);
  return NULL;
}

/* Return the ID directly from the raw payload data. */

SilcBool silc_id_payload_parse_id(const unsigned char *data, SilcUInt32 len,
				  SilcID *ret_id)
{
  SilcBufferStruct buffer;
  SilcIdType type;
  SilcUInt16 idlen;
  unsigned char *id_data;
  int ret;

  if (!ret_id)
    return FALSE;

  silc_buffer_set(&buffer, (unsigned char *)data, len);
  ret = silc_buffer_unformat(&buffer,
			     SILC_STR_UI_SHORT(&type),
			     SILC_STR_UI_SHORT(&idlen),
			     SILC_STR_END);
  if (ret == -1)
    goto err;

  if (type > SILC_ID_CHANNEL)
    goto err;

  silc_buffer_pull(&buffer, 4);

  if (idlen > silc_buffer_len(&buffer) || idlen > SILC_PACKET_MAX_ID_LEN)
    goto err;

  ret = silc_buffer_unformat(&buffer,
			     SILC_STR_DATA(&id_data, idlen),
			     SILC_STR_END);
  if (ret == -1)
    goto err;

  ret_id->type = type;

  if (type == SILC_ID_CLIENT) {
    if (!silc_id_str2id(id_data, idlen, type, &ret_id->u.client_id,
			sizeof(SilcClientID)))
      goto err;
  } else if (type == SILC_ID_SERVER) {
    if (!silc_id_str2id(id_data, idlen, type, &ret_id->u.server_id,
			sizeof(SilcServerID)))
      goto err;
  } else {
    if (!silc_id_str2id(id_data, idlen, type, &ret_id->u.channel_id,
			sizeof(SilcChannelID)))
      goto err;
  }

  return TRUE;

 err:
  SILC_LOG_DEBUG(("Error parsing ID payload"));
  return FALSE;
}

/* Encodes ID Payload */

SilcBuffer silc_id_payload_encode(const void *id, SilcIdType type)
{
  SilcBuffer buffer;
  unsigned char id_data[32];
  SilcUInt32 len;

  if (!silc_id_id2str(id, type, id_data, sizeof(id_data), &len))
    return NULL;
  buffer = silc_id_payload_encode_data((const unsigned char *)id_data,
				       len, type);
  return buffer;
}

SilcBuffer silc_id_payload_encode_data(const unsigned char *id,
				       SilcUInt32 id_len, SilcIdType type)
{
  SilcBuffer buffer;

  buffer = silc_buffer_alloc_size(4 + id_len);
  if (!buffer)
    return NULL;
  silc_buffer_format(buffer,
		     SILC_STR_UI_SHORT(type),
		     SILC_STR_UI_SHORT(id_len),
		     SILC_STR_DATA(id, id_len),
		     SILC_STR_END);
  return buffer;
}

/* Free ID Payload */

void silc_id_payload_free(SilcIDPayload payload)
{
  if (payload) {
    silc_free(payload->id);
    silc_free(payload);
  }
}

/* Get ID type */

SilcIdType silc_id_payload_get_type(SilcIDPayload payload)
{
  return payload ? payload->type : 0;
}

/* Get ID */

SilcBool silc_id_payload_get_id(SilcIDPayload payload, void *ret_id,
				SilcUInt32 ret_id_len)
{
  if (!payload)
    return FALSE;
  return silc_id_str2id(payload->id, payload->len, payload->type,
			ret_id, ret_id_len);
}

/* Get raw ID data. Data is duplicated. */

unsigned char *silc_id_payload_get_data(SilcIDPayload payload)
{
  if (!payload)
    return NULL;

  return silc_memdup(payload->id, payload->len);
}

/* Get length of ID */

SilcUInt32 silc_id_payload_get_len(SilcIDPayload payload)
{
  return payload ? payload->len : 0;
}

/* Converts ID to string. */

SilcBool silc_id_id2str(const void *id, SilcIdType type,
			unsigned char *ret_id, SilcUInt32 ret_id_size,
			SilcUInt32 *ret_id_len)
{
  SilcServerID *server_id;
  SilcClientID *client_id;
  SilcChannelID *channel_id;
  SilcUInt32 id_len = silc_id_get_len(id, type);

  if (id_len > ret_id_size)
    return FALSE;

  if (ret_id_len)
    *ret_id_len = id_len;

  if (id_len > SILC_PACKET_MAX_ID_LEN)
    return FALSE;

  switch(type) {
  case SILC_ID_SERVER:
    server_id = (SilcServerID *)id;
    memcpy(ret_id, server_id->ip.data, server_id->ip.data_len);
    SILC_PUT16_MSB(server_id->port, &ret_id[server_id->ip.data_len]);
    SILC_PUT16_MSB(server_id->rnd, &ret_id[server_id->ip.data_len + 2]);
    return TRUE;
    break;
  case SILC_ID_CLIENT:
    client_id = (SilcClientID *)id;
    memcpy(ret_id, client_id->ip.data, client_id->ip.data_len);
    ret_id[client_id->ip.data_len] = client_id->rnd;
    memcpy(&ret_id[client_id->ip.data_len + 1], client_id->hash,
	   CLIENTID_HASH_LEN);
    return TRUE;
    break;
  case SILC_ID_CHANNEL:
    channel_id = (SilcChannelID *)id;
    memcpy(ret_id, channel_id->ip.data, channel_id->ip.data_len);
    SILC_PUT16_MSB(channel_id->port, &ret_id[channel_id->ip.data_len]);
    SILC_PUT16_MSB(channel_id->rnd, &ret_id[channel_id->ip.data_len + 2]);
    return TRUE;
    break;
  }

  return FALSE;
}

/* Converts string to a ID */

SilcBool silc_id_str2id(const unsigned char *id, SilcUInt32 id_len,
			SilcIdType type, void *ret_id, SilcUInt32 ret_id_size)
{
  if (id_len > SILC_PACKET_MAX_ID_LEN)
    return FALSE;

  switch(type) {
  case SILC_ID_SERVER:
    {
      SilcServerID *server_id = ret_id;

      if (id_len != ID_SERVER_LEN_PART + 4 &&
	  id_len != ID_SERVER_LEN_PART + 16)
	return FALSE;

      if (ret_id_size < sizeof(SilcServerID))
	return FALSE;

      memset(ret_id, 0, ret_id_size);
      memcpy(server_id->ip.data, id, (id_len > ID_SERVER_LEN_PART + 4 ?
				      16 : 4));
      server_id->ip.data_len = (id_len > ID_SERVER_LEN_PART + 4 ? 16 : 4);
      SILC_GET16_MSB(server_id->port, &id[server_id->ip.data_len]);
      SILC_GET16_MSB(server_id->rnd, &id[server_id->ip.data_len + 2]);
      return TRUE;
    }
    break;
  case SILC_ID_CLIENT:
    {
      SilcClientID *client_id = ret_id;

      if (id_len != ID_CLIENT_LEN_PART + 4 &&
	  id_len != ID_CLIENT_LEN_PART + 16)
	return FALSE;

      if (ret_id_size < sizeof(SilcClientID))
	return FALSE;

      memset(ret_id, 0, ret_id_size);
      memcpy(client_id->ip.data, id, (id_len > ID_CLIENT_LEN_PART + 4 ?
				      16 : 4));
      client_id->ip.data_len = (id_len > ID_CLIENT_LEN_PART + 4 ? 16 : 4);
      client_id->rnd = id[client_id->ip.data_len];
      memcpy(client_id->hash, &id[client_id->ip.data_len + 1],
	     CLIENTID_HASH_LEN);
      return TRUE;
    }
    break;
  case SILC_ID_CHANNEL:
    {
      SilcChannelID *channel_id = ret_id;

      if (id_len != ID_CHANNEL_LEN_PART + 4 &&
	  id_len != ID_CHANNEL_LEN_PART + 16)
	return FALSE;

      if (ret_id_size < sizeof(SilcChannelID))
	return FALSE;

      memset(ret_id, 0, ret_id_size);
      memcpy(channel_id->ip.data, id, (id_len > ID_CHANNEL_LEN_PART + 4 ?
				       16 : 4));
      channel_id->ip.data_len = (id_len > ID_CHANNEL_LEN_PART + 4 ? 16 : 4);
      SILC_GET16_MSB(channel_id->port, &id[channel_id->ip.data_len]);
      SILC_GET16_MSB(channel_id->rnd, &id[channel_id->ip.data_len + 2]);
      return TRUE;
    }
    break;
  }

  return FALSE;
}

/* Converts string to ID */

SilcBool silc_id_str2id2(const unsigned char *id, SilcUInt32 id_len,
			 SilcIdType type, SilcID *ret_id)
{
  if (!ret_id)
    return FALSE;

  ret_id->type = type;

  switch (type) {
  case SILC_ID_CLIENT:
    return silc_id_str2id(id, id_len, type, &ret_id->u.client_id,
			  sizeof(ret_id->u.client_id));
    break;

  case SILC_ID_SERVER:
    return silc_id_str2id(id, id_len, type, &ret_id->u.server_id,
			  sizeof(ret_id->u.server_id));
    break;

  case SILC_ID_CHANNEL:
    return silc_id_str2id(id, id_len, type, &ret_id->u.channel_id,
			  sizeof(ret_id->u.channel_id));
    break;
  }

  return FALSE;
}

/* Returns length of the ID */

SilcUInt32 silc_id_get_len(const void *id, SilcIdType type)
{
  switch(type) {
  case SILC_ID_SERVER:
    {
      SilcServerID *server_id = (SilcServerID *)id;
      return ID_SERVER_LEN_PART + server_id->ip.data_len;
    }
    break;
  case SILC_ID_CLIENT:
    {
      SilcClientID *client_id = (SilcClientID *)id;
      return ID_CLIENT_LEN_PART + client_id->ip.data_len;
    }
    break;
  case SILC_ID_CHANNEL:
    {
      SilcChannelID *channel_id = (SilcChannelID *)id;
      return ID_CHANNEL_LEN_PART + channel_id->ip.data_len;
    }
    break;
  }

  return 0;
}

/* Duplicate ID data */

void *silc_id_dup(const void *id, SilcIdType type)
{
  switch(type) {
  case SILC_ID_SERVER:
    {
      SilcServerID *server_id = (SilcServerID *)id;
      return silc_memdup(server_id, sizeof(*server_id));
    }
    break;
  case SILC_ID_CLIENT:
    {
      SilcClientID *client_id = (SilcClientID *)id;
      return silc_memdup(client_id, sizeof(*client_id));
    }
    break;
  case SILC_ID_CHANNEL:
    {
      SilcChannelID *channel_id = (SilcChannelID *)id;
      return silc_memdup(channel_id, sizeof(*channel_id));
    }
    break;
  }

  return NULL;
}