/*
 * 2003-04-07 created by bogdan
 *
 * Copyright (C) 2002-2003 FhG Fokus
 * Copyright (C) 2007-2009 IPTEGO GmbH
 *
 * This file is part of disc, a free diameter server/client.
 *
 * 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; either version 2 of the License, or
 * (at your option) any later version
 *
 * 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.
 *
 * You should have received a copy of the GNU General Public License 
 * along with this program; if not, write to the Free Software 
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

// define EXTRA_DEBUG

#include <stdlib.h>
#include <string.h>
#include <sys/types.h>
#include <netinet/in.h>


#include "mem.h"
#include "log.h"
#include "diameter_msg.h"
#include "avp.h"

#define get_3bytes(_b)						\
  ((((unsigned int)(_b)[0])<<16)|(((unsigned int)(_b)[1])<<8)|	\
   (((unsigned int)(_b)[2])))

#define get_4bytes(_b)						\
  ((((unsigned int)(_b)[0])<<24)|(((unsigned int)(_b)[1])<<16)|	\
   (((unsigned int)(_b)[2])<<8)|(((unsigned int)(_b)[3])))

#define set_3bytes(_b,_v)					\
  {(_b)[0]=((_v)&0x00ff0000)>>16;(_b)[1]=((_v)&0x0000ff00)>>8;	\
    (_b)[2]=((_v)&0x000000ff);}

#define set_4bytes(_b,_v)					\
  {(_b)[0]=((_v)&0xff000000)>>24;(_b)[1]=((_v)&0x00ff0000)>>16;	\
    (_b)[2]=((_v)&0x0000ff00)>>8;(_b)[3]=((_v)&0x000000ff);}

int AAAAVPBuildBuffer(AAA_AVP *avp, unsigned char *dest)  {
  unsigned char* p = dest;

  if (!avp || !dest) {
    ERROR("trying to build msg buffer from/to NULL avp");
    return 0;
  }
  /* AVP HEADER */
  /* avp code */
  set_4bytes(p,avp->code);
  p +=4;
  /* flags */
  (*p++) = (unsigned char)avp->flags;
  /* avp length */
  set_3bytes(p, (AVP_HDR_SIZE(avp->flags)+avp->data.len) );
  p += 3;
  /* vendor id */
  if ((avp->flags&0x80)!=0) {
    set_4bytes(p,avp->vendorId);
    p +=4;
  }
  /* data */
  memcpy( p, avp->data.s, avp->data.len);
  p += to_32x_len( avp->data.len );  

  return p-dest;
}

/* from a AAAMessage structure, a buffer to be send is build
 */
AAAReturnCode AAABuildMsgBuffer( AAAMessage *msg )
{
  unsigned char *p;
  AAA_AVP       *avp;
  AAA_AVP       *mem; // group member

  /* first let's compute the length of the buffer */
  msg->buf.len = AAA_MSG_HDR_SIZE; /* AAA message header size */
  /* count and add the avps */
  for(avp=msg->avpList.head;avp;avp=avp->next) {
    msg->buf.len += AVP_HDR_SIZE(avp->flags)+ to_32x_len( avp->data.len );
  }

  //	DBG("xxxx len=%d\n",msg->buf.len);
  /* allocate some memory */
  msg->buf.s = (char*)ad_malloc( msg->buf.len );
  if (!msg->buf.s) {
    ERROR("ERROR:AAABuildMsgBuffer: no more free memory!\n");
    goto error;
  }
  memset(msg->buf.s, 0, msg->buf.len);

  /* fill in the buffer */
  p = (unsigned char*)msg->buf.s;
  /* DIAMETER HEADER */
  /* message length */
  ((unsigned int*)p)[0] =htonl(msg->buf.len);
  /* Diameter Version */
  *p = 1;
  p += VER_SIZE + MESSAGE_LENGTH_SIZE;
  /* command code */
  ((unsigned int*)p)[0] = htonl(msg->commandCode);
  /* flags */
  *p = (unsigned char)msg->flags;
  p += FLAGS_SIZE + COMMAND_CODE_SIZE;
  /* application-ID */
  ((unsigned int*)p)[0] = htonl(msg->applicationId);
  p += APPLICATION_ID_SIZE;
  /* hop by hop id */
  ((unsigned int*)p)[0] = msg->hopbyhopId;
  p += HOP_BY_HOP_IDENTIFIER_SIZE;
  /* end to end id */
  ((unsigned int*)p)[0] = msg->endtoendId;
  p += END_TO_END_IDENTIFIER_SIZE;

  /* AVPS */
  for(avp=msg->avpList.head;avp;avp=avp->next) {
    /* AVP HEADER */
    /* avp code */
    set_4bytes(p,avp->code);
    p +=4;
    /* flags */
    (*p++) = (unsigned char)avp->flags;
    /* avp length */
    set_3bytes(p, (AVP_HDR_SIZE(avp->flags)+avp->data.len) );
    p += 3;
    /* vendor id */
    if ((avp->flags&0x80)!=0) {
      set_4bytes(p,avp->vendorId);
      p +=4;
    }
    /* data */
    if (!avp->groupedHead) {
      memcpy( p, avp->data.s, avp->data.len);
      p += to_32x_len( avp->data.len );
    } else {  
      // group members
      for(mem=avp->groupedHead;mem;mem=mem->next)
	p+=AAAAVPBuildBuffer(mem, p);
    }
  }

  if ((char*)p-msg->buf.s!=msg->buf.len) {
    ERROR("BUG: build_buf_from_msg: mismatch between len and buf!\n");
    ad_free( msg->buf.s );
    msg->buf.s = 0;
    msg->buf.len = 0;
    goto error;
  }
  //	DBG("Message: %.*s\n", msg->buf.len, msg->buf.s);
  return AAA_ERR_SUCCESS;
 error:
  return -1;
}

/* frees a message allocated through AAANewMessage()
 */
AAAReturnCode  AAAFreeMessage(AAAMessage **msg)
{
  AAA_AVP *avp_t;
  AAA_AVP *avp;

  /* param check */
  if (!msg || !(*msg))
    goto done;

  /* free the avp list */
  avp = (*msg)->avpList.head;
  while (avp) {
    avp_t = avp;
    avp = avp->next;
    /*free the avp*/
    AAAFreeAVP(&avp_t);
  }

  /* free the buffer (if any) */
  if ( (*msg)->buf.s )
    ad_free( (*msg)->buf.s );

  /* free the AAA msg */
  ad_free(*msg);
  msg = 0;

 done:
  return AAA_ERR_SUCCESS;
}



/* Sets the proper result_code into the Result-Code AVP; thus avp must already
 * exists into the reply message */
AAAReturnCode  AAASetMessageResultCode(
				       AAAMessage *message,
				       AAAResultCode resultCode)
{
  if ( !is_req(message) && message->res_code) {
    *((unsigned int*)(message->res_code->data.s)) = htonl(resultCode);
    return AAA_ERR_SUCCESS;
  }
  return AAA_ERR_FAILURE;
}



/* This function convert message to message structure */
AAAMessage* AAATranslateMessage( unsigned char* source, unsigned int sourceLen,
				 int attach_buf)
{
  unsigned char *ptr;
  AAAMessage    *msg;
  unsigned char version;
  unsigned int  msg_len;
  AAA_AVP       *avp;
  unsigned int  avp_code;
  unsigned char avp_flags;
  unsigned int  avp_len;
  unsigned int  avp_vendorID;
  unsigned int  avp_data_len;

  /* check the params */
  if( !source || !sourceLen || sourceLen<AAA_MSG_HDR_SIZE) {
    ERROR("ERROR:AAATranslateMessage: could not decipher "
	  "received message - wrong size (%d)!\n", sourceLen);
    goto error;
  }

  /* inits */
  msg = 0;
  avp = 0;
  ptr = source;

  /* alloc a new message structure */
  msg = (AAAMessage*)ad_malloc(sizeof(AAAMessage));
  if (!msg) {
    ERROR("ERROR:AAATranslateMessage: no more free memory!!\n");
    goto error;
  }
  memset(msg,0,sizeof(AAAMessage));

  /* get the version */
  version = (unsigned char)*ptr;
  ptr += VER_SIZE;
  if (version!=1) {
    ERROR("ERROR:AAATranslateMessage: invalid version [%d]in "
	  "AAA msg\n",version);
    goto error;
  }

  /* message length */
  msg_len = get_3bytes( ptr );
  ptr += MESSAGE_LENGTH_SIZE;
  if (msg_len>sourceLen) {
    ERROR("ERROR:AAATranslateMessage: AAA message len [%d] bigger then"
	  " buffer len [%d]\n",msg_len,sourceLen);
    goto error;
  }

  /* command flags */
  msg->flags = *ptr;
  ptr += FLAGS_SIZE;

  /* command code */
  msg->commandCode = get_3bytes( ptr );
  ptr += COMMAND_CODE_SIZE;

  /* application-Id */
  msg->applicationId = get_4bytes( ptr );
  ptr += APPLICATION_ID_SIZE;

  /* Hop-by-Hop-Id */
  msg->hopbyhopId = *((unsigned int*)ptr);
  ptr += HOP_BY_HOP_IDENTIFIER_SIZE;

  /* End-to-End-Id */
  msg->endtoendId = *((unsigned int*)ptr);
  ptr += END_TO_END_IDENTIFIER_SIZE;

  /* start decoding the AVPS */
  while (ptr < source+msg_len) {
    if (ptr+AVP_HDR_SIZE(0x80)>source+msg_len){
      ERROR("ERROR:AAATranslateMessage: source buffer to short!! "
	    "Cannot read the whole AVP header!\n");
      goto error;
    }
    /* avp code */
    avp_code = get_4bytes( ptr );
    ptr += AVP_CODE_SIZE;
    /* avp flags */
    avp_flags = (unsigned char)*ptr;
    ptr += AVP_FLAGS_SIZE;
    /* avp length */
    avp_len = get_3bytes( ptr );
    ptr += AVP_LENGTH_SIZE;
    if (avp_len<1) {
      ERROR("ERROR:AAATranslateMessage: invalid AVP len [%d]\n",
	    avp_len);
      goto error;
    }
    /* avp vendor-ID */
    avp_vendorID = 0;
    if (avp_flags&AAA_AVP_FLAG_VENDOR_SPECIFIC) {
      avp_vendorID = get_4bytes( ptr );
      ptr += AVP_VENDOR_ID_SIZE;
    }
    /* data length */
    avp_data_len = avp_len-AVP_HDR_SIZE(avp_flags);
    /*check the data length */
    if ( source+msg_len<ptr+avp_data_len) {
      ERROR("ERROR:AAATranslateMessage: source buffer to short!! "
	    "Cannot read a whole data for AVP!\n");
      goto error;
    }

    /* create the AVP */
    avp = AAACreateAVP( avp_code, avp_flags, avp_vendorID, (char*)ptr,
			avp_data_len, AVP_DONT_FREE_DATA);
    if (!avp)
      goto error;

    /* link the avp into aaa message to the end */
    AAAAddAVPToMessage( msg, avp, msg->avpList.tail);

    ptr += to_32x_len( avp_data_len );
  }

  /* link the buffer to the message */
  if (attach_buf) {
    msg->buf.s = (char*)source;
    msg->buf.len = msg_len;
  }

  //AAAPrintMessage( msg );
  return  msg;
 error:
  ERROR("ERROR:AAATranslateMessage: message conversion droped!!\n");
  AAAFreeMessage(&msg);
  return 0;
}

/* create a new minimal AAA message */
AAAMessage* AAAInMessage(AAACommandCode commandCode, AAAApplicationId appId)
{
  AAAMessage   *msg;

  /* we allocate a new AAAMessage structure and set it to 0 */
  msg = (AAAMessage*)ad_malloc(sizeof(AAAMessage));
  if (!msg) 
    {
      ERROR("diameter_authorize(): no more free memory!\n");
      return NULL;
    }
  memset(msg, 0, sizeof(AAAMessage));

  /* command code */
  msg->commandCode = commandCode;

  /* application ID */
  msg->applicationId = appId;

  /* it's a new request -> set the flag */
  msg->flags = 0x80;

  return msg;
}

AAAMessage* AAAMessageSetReply(AAAMessage* msg) {
  msg->flags &= (!0x80);
  return msg;
}

/* print as debug all info contained by an aaa message + AVPs
 */
void AAAPrintMessage( AAAMessage *msg)
{
  char    buf[1024];
  AAA_AVP *avp;

  /* print msg info */
  DBG("DEBUG: AAA_MESSAGE - %p\n",msg);
  DBG("\tCode = %u\n",msg->commandCode);
  DBG("\tFlags = %x\n",msg->flags);

  /*print the AVPs */
  avp = msg->avpList.head;
  while (avp) {
    AAAConvertAVPToString(avp,buf,1024);
    DBG("\n%s\n",buf);
    avp=avp->next;
  }
}