socket.c

//* ****************************************************************************
//! \file socket.c
//! \brief SOCKET APIs Implements file.
//! \details SOCKET APIs like as Berkeley Socket APIs. 
//! \version 1.0.1
//! \date 2020/04/27
//! \par  Revision history
//!   <2020/04/27> V1.0.1 Modify default value of tcmd to Sn_CR_SEND to send data 
//!                in macrawmode and the condition of the if()when setting
//!	               the destination port number.
//!   <2019/01/01> 1st Release
//! \author MidnightCow
//! \copyright
//!
//! Copyright (c)  2019, WIZnet Co., LTD.
//!
//! Permission is hereby granted, free of charge, to any person obtaining a copy
//! of this software and associated documentation files (the "Software"), to deal
//! in the Software without restriction, including without limitation the rights 
//! to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
//! copies of the Software, and to permit persons to whom the Software is 
//! furnished to do so, subject to the following conditions: 
//!
//! The above copyright notice and this permission notice shall be included in
//! all copies or substantial portions of the Software. 
//!
//! THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
//! IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
//! FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
//! AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
//! LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
//! OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
//! SOFTWARE. 
//!
//*****************************************************************************

#include <stdio.h>
#include "socket.h"
#include "w6100.h"

#define SOCK_ANY_PORT_NUM  0x0400

static uint16_t sock_any_port = SOCK_ANY_PORT_NUM;
static uint16_t sock_io_mode = 0;
static uint16_t sock_is_sending = 0;
static datasize_t sock_remained_size[_WIZCHIP_SOCK_NUM_] = {0,0,};
static uint8_t  sock_pack_info[_WIZCHIP_SOCK_NUM_] = {0,};


#define CHECK_SOCKNUM()                                    \
   do{                                                     \
      if(sn >= _WIZCHIP_SOCK_NUM_) return SOCKERR_SOCKNUM; \
   }while(0);

#define CHECK_SOCKMODE(mode)                                      \
   do{                                                            \
      if((getSn_MR(sn) & 0x0F) != mode) return SOCKERR_SOCKMODE;  \
   }while(0);

#define CHECK_TCPMODE()                                           \
   do{                                                            \
      if((getSn_MR(sn) & 0x03) != 0x01) return SOCKERR_SOCKMODE;  \
   }while(0);

#define CHECK_UDPMODE()                                           \
   do{                                                            \
      if((getSn_MR(sn) & 0x03) != 0x02) return SOCKERR_SOCKMODE;  \
   }while(0);

#define CHECK_IPMODE()                                            \
   do{                                                            \
      if((getSn_MR(sn) & 0x07) != 0x03) return SOCKERR_SOCKMODE;  \
   }while(0);

#define CHECK_DGRAMMODE()                                         \
   do{                                                            \
      if(getSn_MR(sn) == Sn_MR_CLOSED) return SOCKERR_SOCKMODE;   \
      if((getSn_MR(sn) & 0x03) == 0x01) return SOCKERR_SOCKMODE;  \
   }while(0);


#define CHECK_SOCKINIT()                                       \
   do{                                                         \
      if((getSn_SR(sn) != SOCK_INIT)) return SOCKERR_SOCKINIT; \
   }while(0);                

#define CHECK_SOCKDATA()                   \
   do{                                     \
      if(len == 0) return SOCKERR_DATALEN; \
   }while(0);     

#define CHECK_IPZERO(addr, addrlen)                                  \
   do{                                                               \
      uint16_t ipzero= 0;                                            \
      for(uint8_t i=0; i<addrlen; i++)  ipzero += (uint16_t)addr[i]; \
      if (ipzero == 0) return SOCKERR_IPINVALID;                     \
   }while(0);



int8_t socket(uint8_t sn, uint8_t protocol, uint16_t port, uint8_t flag)
{ 
   uint8_t taddr[16];
   uint16_t local_port=0;
   CHECK_SOCKNUM(); 
   switch (protocol & 0x0F)
   {
      case Sn_MR_TCP4 :
         getSIPR(taddr);
         CHECK_IPZERO(taddr, 4);
         break;
      case Sn_MR_TCP6 :
         getLLAR(taddr);
         CHECK_IPZERO(taddr, 16);
         //getGUAR(taddr);
         //CHECK_IPZERO(taddr, 16);
         break;
      case Sn_MR_TCPD :  
         getSIPR(taddr);
         CHECK_IPZERO(taddr, 4);
         getLLAR(taddr);
         CHECK_IPZERO(taddr, 16);
         //getGUAR(taddr);
         //CHECK_IPZERO(taddr, 16);
         break;
      case Sn_MR_UDP :
      case Sn_MR_UDP6 :
      case Sn_MR_UDPD :
      case Sn_MR_MACRAW :
      case Sn_MR_IPRAW4 :
      case Sn_MR_IPRAW6 :
         break; 
      default :
        return SOCKERR_SOCKMODE;
   } 

   if((flag & 0x04)) return SOCKERR_SOCKFLAG;
   if(flag != 0)
   {
      switch(protocol)
      {
         case Sn_MR_MACRAW:
            if((flag & (SF_DHA_MANUAL | SF_FORCE_ARP)) != 0)
            	return SOCKERR_SOCKFLAG;
            break;
         case Sn_MR_TCP4:
         case Sn_MR_TCP6:
         case Sn_MR_TCPD:     
            if((flag & (SF_MULTI_ENABLE | SF_UNI_BLOCK)) !=0)
            	return SOCKERR_SOCKFLAG;
            break;
         case Sn_MR_IPRAW4:
         case Sn_MR_IPRAW6:
            if(flag !=0)
            	return SOCKERR_SOCKFLAG;
            break;
         default:
            break;
      }
   }
   close(sn);
   setSn_MR(sn,(protocol | (flag & 0xF0)));
   setSn_MR2(sn, flag & 0x03);  
   if(!port)
   {
      port = sock_any_port++;
      if(sock_any_port == 0xFFF0) sock_any_port = SOCK_ANY_PORT_NUM;
   }
   setSn_PORTR(sn,port);
   setSn_CR(sn,Sn_CR_OPEN);

   while(getSn_CR(sn));

   sock_io_mode &= ~(1 <<sn);
   sock_io_mode |= ((flag & (SF_IO_NONBLOCK>>3)) << sn);
   sock_is_sending &= ~(1<<sn);
   sock_remained_size[sn] = 0;
   sock_pack_info[sn] = PACK_NONE;

   while(getSn_SR(sn) == SOCK_CLOSED) ;
//   printf("[%d]%d\r\n", sn, getSn_PORTR(sn));
   return sn;
}  


int8_t close(uint8_t sn)
{
   CHECK_SOCKNUM();
   setSn_CR(sn,Sn_CR_CLOSE);
   /* wait to process the command... */
   while( getSn_CR(sn) );
   /* clear all interrupt of SOCKETn. */
   setSn_IRCLR(sn, 0xFF);
   /* Release the sock_io_mode of SOCKETn. */
   sock_io_mode &= ~(1<<sn); 
   sock_remained_size[sn] = 0;
   sock_is_sending &= ~(1<<sn);
   sock_pack_info[sn] = PACK_NONE;
   while(getSn_SR(sn) != SOCK_CLOSED);
   return SOCK_OK;
}


int8_t listen(uint8_t sn)
{
   CHECK_SOCKNUM();
   CHECK_SOCKINIT();
   setSn_CR(sn,Sn_CR_LISTEN);
   while(getSn_CR(sn));
   while(getSn_SR(sn) != SOCK_LISTEN)
   {
      close(sn);
      return SOCKERR_SOCKCLOSED;
   }
   return SOCK_OK;
}


int8_t connect(uint8_t sn, uint8_t * addr, uint16_t port, uint8_t addrlen)
{ 

   CHECK_SOCKNUM();
   CHECK_TCPMODE();
   CHECK_SOCKINIT();
  
   CHECK_IPZERO(addr, addrlen);
   if(port == 0)
	   return SOCKERR_PORTZERO;

   setSn_DPORTR(sn, port);
  
   if (addrlen == 16)     // addrlen=16, Sn_MR_TCP6(1001), Sn_MR_TCPD(1101))
   {
      if( getSn_MR(sn) & 0x08)  
      {
         setSn_DIP6R(sn,addr);
         setSn_CR(sn,Sn_CR_CONNECT6);
      }
      else return SOCKERR_SOCKMODE;
   } 
   else           // addrlen=4, Sn_MR_TCP4(0001), Sn_MR_TCPD(1101)
   {
      if(getSn_MR(sn) == Sn_MR_TCP6) return SOCKERR_SOCKMODE;
      setSn_DIPR(sn,addr);
      setSn_CR(sn,Sn_CR_CONNECT);
   }
   while(getSn_CR(sn));

   if(sock_io_mode & (1<<sn)) return SOCK_BUSY;

   while(getSn_SR(sn) != SOCK_ESTABLISHED)
   {
      if (getSn_IR(sn) & Sn_IR_TIMEOUT)
      {
         setSn_IRCLR(sn, Sn_IR_TIMEOUT);
         return SOCKERR_TIMEOUT;
      }
      if (getSn_SR(sn) == SOCK_CLOSED)
      {
         return SOCKERR_SOCKCLOSED;
      }
   } 
   return SOCK_OK;
}

int8_t disconnect(uint8_t sn)
{
   CHECK_SOCKNUM();
   CHECK_TCPMODE();
   if(getSn_SR(sn) != SOCK_CLOSED)
   {
      setSn_CR(sn,Sn_CR_DISCON);
      /* wait to process the command... */
      while(getSn_CR(sn));
      if(sock_io_mode & (1<<sn)) return SOCK_BUSY;
      while(getSn_SR(sn) != SOCK_CLOSED)
      {
         if(getSn_IR(sn) & Sn_IR_TIMEOUT)
         {
            close(sn);
            return SOCKERR_TIMEOUT;
         }
      }
   }
   return SOCK_OK;
}


datasize_t send(uint8_t sn, uint8_t * buf, datasize_t len)
{
   uint8_t tmp=0;
   datasize_t freesize=0;
   /* 
    * The below codes can be omitted for optmization of speed
    */
   //CHECK_SOCKNUM();
   //CHECK_TCPMODE(Sn_MR_TCP4);
   /************/

   freesize = getSn_TxMAX(sn);
   if (len > freesize) len = freesize; // check size not to exceed MAX size.
   while(1)
   {
      freesize = (datasize_t)getSn_TX_FSR(sn);
      tmp = getSn_SR(sn);
      if ((tmp != SOCK_ESTABLISHED) && (tmp != SOCK_CLOSE_WAIT))
      {
         if(tmp == SOCK_CLOSED) close(sn);
         return SOCKERR_SOCKSTATUS;
      }
      if(len <= freesize) break;
      if( sock_io_mode & (1<<sn) ) return SOCK_BUSY;  
   }
   wiz_send_data(sn, buf, len);
   if(sock_is_sending & (1<<sn))
   {
      while ( !(getSn_IR(sn) & Sn_IR_SENDOK) )
      {    
         tmp = getSn_SR(sn);
         if ((tmp != SOCK_ESTABLISHED) && (tmp != SOCK_CLOSE_WAIT) )
         {
            if( (tmp == SOCK_CLOSED) || (getSn_IR(sn) & Sn_IR_TIMEOUT) ) close(sn);
            return SOCKERR_SOCKSTATUS;
         }
         if(sock_io_mode & (1<<sn)) return SOCK_BUSY;
      } 
      setSn_IRCLR(sn, Sn_IR_SENDOK);
   }
   setSn_CR(sn,Sn_CR_SEND);
 
   while(getSn_CR(sn));   // wait to process the command...
   sock_is_sending |= (1<<sn);
 
   return len;
}


datasize_t recv(uint8_t sn, uint8_t * buf, datasize_t len)
{
   uint8_t  tmp = 0;
   datasize_t recvsize = 0;
   /* 
    * The below codes can be omitted for optmization of speed
    */
   //CHECK_SOCKNUM();
   //CHECK_TCPMODE();
   //CHECK_SOCKDATA();
   /************/
 
   recvsize = getSn_RxMAX(sn); 
   if(recvsize < len) len = recvsize;
   while(1)
   {
      recvsize = (datasize_t)getSn_RX_RSR(sn);
      tmp = getSn_SR(sn);
      if (tmp != SOCK_ESTABLISHED && tmp != SOCK_CLOSE_WAIT)
      {
         if(tmp == SOCK_CLOSED) close(sn);
         return SOCKERR_SOCKSTATUS;
      }
      if(recvsize) break;
      if(sock_io_mode & (1<<sn)) return SOCK_BUSY;
   }
   if(recvsize < len) len = recvsize;
   wiz_recv_data(sn, buf, len); 
   setSn_CR(sn,Sn_CR_RECV); 
   while(getSn_CR(sn));  
   return len;
}


datasize_t sendto(uint8_t sn, uint8_t * buf, datasize_t len, uint8_t * addr, uint16_t port, uint8_t addrlen)
{
   uint8_t tmp = 0;
   uint8_t tcmd = Sn_CR_SEND;
   uint16_t freesize = 0;
   /* 
    * The below codes can be omitted for optmization of speed
    */
   //CHECK_SOCKNUM();
   //CHECK_DGRAMMODE();
   /************/
   tmp = getSn_MR(sn);
   if(tmp != Sn_MR_MACRAW)
   {
       if (addrlen == 16)      // addrlen=16, Sn_MR_UDP6(1010), Sn_MR_UDPD(1110)), IPRAW6(1011)
      {
         if( tmp & 0x08)  
         {
            setSn_DIP6R(sn,addr);
            tcmd = Sn_CR_SEND6;
         }
         else return SOCKERR_SOCKMODE;
      } 
      else if(addrlen == 4)      // addrlen=4, Sn_MR_UDP4(0010), Sn_MR_UDPD(1110), IPRAW4(0011)
      {
         if(tmp == Sn_MR_UDP6 || tmp == Sn_MR_IPRAW6) return SOCKERR_SOCKMODE;
         setSn_DIPR(sn,addr);
         tcmd = Sn_CR_SEND;
      }
      else return SOCKERR_IPINVALID;
   }
   if((tmp & 0x03)==0x02)     // Sn_MR_UPD4(0010), Sn_MR_UDP6(1010), Sn_MR_UDPD(1110)
   {
      if(port){ setSn_DPORTR(sn, port);}
      else   return SOCKERR_PORTZERO;
   }
  
   freesize = getSn_TxMAX(sn);
   if (len > freesize) len = freesize; // check size not to exceed MAX size.
  
   while(1)
   {
      freesize = getSn_TX_FSR(sn);
      if(getSn_SR(sn) == SOCK_CLOSED) return SOCKERR_SOCKCLOSED;
      if(len <= freesize) break;
      if( sock_io_mode & (1<<sn) ) return SOCK_BUSY;  
   }
   wiz_send_data(sn, buf, len);
   setSn_CR(sn,tcmd);
   while(getSn_CR(sn));
  
   while(1)
   {
      tmp = getSn_IR(sn);
      if(tmp & Sn_IR_SENDOK)
      {
         setSn_IRCLR(sn, Sn_IR_SENDOK);
         break;
      }  
      else if(tmp & Sn_IR_TIMEOUT)
      {
         setSn_IRCLR(sn, Sn_IR_TIMEOUT);   
         return SOCKERR_TIMEOUT;
      }
   }  
   return (int32_t)len;
}


datasize_t recvfrom(uint8_t sn, uint8_t * buf, datasize_t len, uint8_t * addr, uint16_t *port, uint8_t *addrlen)
{ 
   uint8_t  head[2];
   datasize_t pack_len=0;
  
   /* 
    * The below codes can be omitted for optmization of speed
    */
   //CHECK_SOCKNUM();
   //CHECK_DGRAMMODE();
   //CHECK_SOCKDATA();
   /************/
  
   if(sock_remained_size[sn] == 0)
   {
      while(1)
      {
         pack_len = getSn_RX_RSR(sn);
         if(getSn_SR(sn) == SOCK_CLOSED) return SOCKERR_SOCKCLOSED;
         if(pack_len != 0)
         {
            sock_pack_info[sn] = PACK_NONE;
            break;
         } 
         if( sock_io_mode & (1<<sn) ) return SOCK_BUSY;
      };
      /* First read 2 bytes of PACKET INFO in SOCKETn RX buffer*/
      wiz_recv_data(sn, head, 2);  
      setSn_CR(sn,Sn_CR_RECV);
      while(getSn_CR(sn));
      pack_len = head[0] & 0x07;
      pack_len = (pack_len << 8) + head[1];
    
      switch (getSn_MR(sn) & 0x0F)
      {
         case Sn_MR_UDP4 :
         case Sn_MR_UDP6:
         case Sn_MR_UDPD:
         case Sn_MR_IPRAW6:
         case Sn_MR_IPRAW4 : 
            if(addr == 0) return SOCKERR_ARG;
            sock_pack_info[sn] = head[0] & 0xF8;
            if(sock_pack_info[sn] & PACK_IPv6) *addrlen = 16;
            else *addrlen = 4;
            wiz_recv_data(sn, addr, *addrlen);
            setSn_CR(sn,Sn_CR_RECV);
            while(getSn_CR(sn));
            break;
         case Sn_MR_MACRAW :
			pack_len-=2;
            if(pack_len > 1514) 
            {
               close(sn);
               return SOCKFATAL_PACKLEN;
            }
            break; 
         default:
            return SOCKERR_SOCKMODE;
            break;
      }
      sock_remained_size[sn] = pack_len;
      sock_pack_info[sn] |= PACK_FIRST;
      if((getSn_MR(sn) & 0x03) == 0x02)  // Sn_MR_UDP4(0010), Sn_MR_UDP6(1010), Sn_MR_UDPD(1110)
      {
         /* Read port number of PACKET INFO in SOCKETn RX buffer */
         if(port==0) return SOCKERR_ARG;
         wiz_recv_data(sn, head, 2);
         *port = ( ((((uint16_t)head[0])) << 8) + head[1] );
         setSn_CR(sn,Sn_CR_RECV);
         while(getSn_CR(sn));   
      }
   }   
   
   if   (len < sock_remained_size[sn]) pack_len = len;
   else pack_len = sock_remained_size[sn];    
   wiz_recv_data(sn, buf, pack_len);
   setSn_CR(sn,Sn_CR_RECV);  
   /* wait to process the command... */
   while(getSn_CR(sn)) ;
 
   sock_remained_size[sn] -= pack_len; 
   if(sock_remained_size[sn] != 0) sock_pack_info[sn] |= PACK_REMAINED; 
   else sock_pack_info[sn] |= PACK_COMPLETED; 
 
   return pack_len;
}

int8_t ctlsocket(uint8_t sn, ctlsock_type cstype, void* arg)
{
   uint8_t tmp = 0;
   CHECK_SOCKNUM();
   tmp = *((uint8_t*)arg); 
   switch(cstype)
   {
      case CS_SET_IOMODE:
         if(tmp == SOCK_IO_NONBLOCK)  sock_io_mode |= (1<<sn);
         else if(tmp == SOCK_IO_BLOCK) sock_io_mode &= ~(1<<sn);
         else return SOCKERR_ARG;
         break;
      case CS_GET_IOMODE: 
         *((uint8_t*)arg) = (uint8_t)((sock_io_mode >> sn) & 0x0001);
         break;
      case CS_GET_MAXTXBUF:
         *((datasize_t*)arg) = getSn_TxMAX(sn);
         break;
      case CS_GET_MAXRXBUF:  
         *((datasize_t*)arg) = getSn_RxMAX(sn);
         break;
      case CS_CLR_INTERRUPT:
         if( tmp > SIK_ALL) return SOCKERR_ARG;
         setSn_IRCLR(sn,tmp);
         break;
      case CS_GET_INTERRUPT:
         *((uint8_t*)arg) = getSn_IR(sn);
         break;
      case CS_SET_INTMASK:
         if( tmp > SIK_ALL) return SOCKERR_ARG;
         setSn_IMR(sn,tmp);
         break;
      case CS_GET_INTMASK:
         *((uint8_t*)arg) = getSn_IMR(sn);
         break;
      case CS_SET_PREFER:
    	  if((tmp & 0x03) == 0x01) return SOCKERR_ARG;
    	  setSn_PSR(sn, tmp);
    	  break;
      case CS_GET_PREFER:
    	  *(uint8_t*) arg = getSn_PSR(sn);
    	  break;
      default:
         return SOCKERR_ARG;
   }
   return SOCK_OK;
}

int8_t setsockopt(uint8_t sn, sockopt_type sotype, void* arg)
{
   CHECK_SOCKNUM();
   switch(sotype)
   {
      case SO_TTL:
         setSn_TTLR(sn,*(uint8_t*)arg);
         break;
      case SO_TOS:
         setSn_TOSR(sn,*(uint8_t*)arg);
         break;
      case SO_MSS:
         setSn_MSSR(sn,*(uint16_t*)arg);
         break;
      case SO_DESTIP:
         if(((wiz_IPAddress*)arg)->len == 16) setSn_DIP6R(sn, ((wiz_IPAddress*)arg)->ip);
         else           setSn_DIPR(sn, ((wiz_IPAddress*)arg)->ip);
         break;
      case SO_DESTPORT:
         setSn_DPORTR(sn, *(uint16_t*)arg);
         break;
      case SO_KEEPALIVESEND:
         CHECK_TCPMODE();   
         if(getSn_KPALVTR(sn) != 0) return SOCKERR_SOCKOPT;
         setSn_CR(sn,Sn_CR_SEND_KEEP);
         while(getSn_CR(sn) != 0)
         {     
            if (getSn_IR(sn) & Sn_IR_TIMEOUT)
            {
               setSn_IRCLR(sn, Sn_IR_TIMEOUT);
               return SOCKERR_TIMEOUT;
            }
         }
         break;
      case SO_KEEPALIVEAUTO:
         CHECK_TCPMODE();
         setSn_KPALVTR(sn,*(uint8_t*)arg);
         break;   
      default:
         return SOCKERR_ARG;
   } 
   return SOCK_OK;
}

int8_t getsockopt(uint8_t sn, sockopt_type sotype, void* arg)
{
   CHECK_SOCKNUM();
   switch(sotype)
   {
      case SO_FLAG:
         *(uint8_t*)arg = (getSn_MR(sn) & 0xF0) | (getSn_MR2(sn)) | ((uint8_t)(((sock_io_mode >> sn) & 0x0001) << 3));
         break;
      case SO_TTL:
         *(uint8_t*) arg = getSn_TTLR(sn);
         break;
      case SO_TOS:
         *(uint8_t*) arg = getSn_TOSR(sn);
         break;
      case SO_MSS: 
         *(uint16_t*) arg = getSn_MSSR(sn);
         break;
      case SO_DESTIP:
         CHECK_TCPMODE();
         if(getSn_ESR(sn) & TCPSOCK_MODE) //IPv6 ?
         {
            getSn_DIP6R(sn, ((wiz_IPAddress*)arg)->ip);
            ((wiz_IPAddress*)arg)->len = 16;
         } 
         else
         {
            getSn_DIPR(sn, ((wiz_IPAddress*)arg)->ip);
            ((wiz_IPAddress*)arg)->len = 4;
         } 
         break;
      case SO_DESTPORT:  
         *(uint16_t*) arg = getSn_DPORTR(sn);
         break; 
      case SO_KEEPALIVEAUTO:
         CHECK_TCPMODE();
         *(uint16_t*) arg = getSn_KPALVTR(sn);
         break;
      case SO_SENDBUF:
         *(datasize_t*) arg = getSn_TX_FSR(sn);
         break;
      case SO_RECVBUF:
         *(datasize_t*) arg = getSn_RX_RSR(sn);
         break;
      case SO_STATUS:
         *(uint8_t*) arg = getSn_SR(sn);
         break;
      case SO_EXTSTATUS:
         CHECK_TCPMODE();
         *(uint8_t*) arg = getSn_ESR(sn) & 0x07;
         break;
      case SO_REMAINSIZE:
         if(getSn_MR(sn)==SOCK_CLOSED) return SOCKERR_SOCKSTATUS;
         if(getSn_MR(sn) & 0x01)   *(uint16_t*)arg = getSn_RX_RSR(sn);
         else                      *(uint16_t*)arg = sock_remained_size[sn];
         break;
      case SO_PACKINFO:
         if(getSn_MR(sn)==SOCK_CLOSED) return SOCKERR_SOCKSTATUS;
         if(getSn_MR(sn) & 0x01)       return SOCKERR_SOCKMODE;
         else *(uint8_t*)arg = sock_pack_info[sn];
         break;
      case SO_MODE:
         *(uint8_t*) arg = 0x0F & getSn_MR(sn);
         break;
      default:
         return SOCKERR_SOCKOPT;
   }
   return SOCK_OK;
}

int16_t peeksockmsg(uint8_t sn, uint8_t* submsg, uint16_t subsize)
{
   uint32_t rx_ptr = 0;
   uint16_t i = 0, sub_idx = 0;

   if( (getSn_RX_RSR(sn) > 0) && (subsize > 0) )
   {
       rx_ptr = ((uint32_t)getSn_RX_RD(sn) << 8)  + WIZCHIP_RXBUF_BLOCK(sn);
       sub_idx = 0;
       for(i = 0; i < getSn_RX_RSR(sn) ; i++)
       {
          if(WIZCHIP_READ(rx_ptr) == submsg[sub_idx])
          {
              sub_idx++;
              if(sub_idx == subsize) return (i + 1 - sub_idx);
          }
          else sub_idx = 0;
          rx_ptr = WIZCHIP_OFFSET_INC(rx_ptr,1);
       }
   }
   return -1;
}