IP校验和不对..

[Aweiwei_]

关键代码..

typedef struct ip_hdr 
{
  /*unsigned char	
  			version:4,
  			ihl:4;*/

  unsigned char 	h_ver;
  unsigned char		tos;
  unsigned short	tot_len;
  unsigned short	id;
  unsigned short
  			zero:1,
			frag:1,
			more_frag:1,	
  			frag_off:13; 			
  unsigned char		ttl;
  unsigned char		protocol;
  unsigned short	checkSum;
  unsigned long		saddr;
  unsigned long		daddr;
  /*The options start here. */
}IP_HEADER;

unsigned short checkSum(unsigned char * buff, int wlen)
{
    unsigned long sum = 0;

    if (wlen) {
    	unsigned long bogus;
	 __asm__("clc\n"
		"1:\t"
		"lodsl\n\t"
		"adcl %3, %0\n\t"
		"decl %2\n\t"
		"jne 1b\n\t"
		"adcl $0, %0\n\t"
		"movl %0, %3\n\t"
		"shrl $16, %3\n\t"
		"addw %w3, %w0\n\t"
		"adcw $0, %w0"
	    : "=r" (sum), "=S" (buff), "=r" (wlen), "=a" (bogus)
	    : "0"  (sum),  "1" (buff),  "2" (wlen));
    }
    return (~sum) & 0xffff;
}

int IPGen(ip_hdr *hdr,unsigned long srcIP,unsigned long dstIP)
{
	/*hdr->version=4;
	hdr->ihl=5;//= =?*/
	hdr->h_ver=(4<<4 | sizeof(ip_hdr)/sizeof(unsigned int));
	hdr->tos=0;
	hdr->tot_len=sizeof(ip_hdr)+sizeof(tcp_hdr);
	hdr->id=0;
	hdr->zero=0;
	hdr->frag=0;
	hdr->more_frag=0;
	hdr->frag_off=0;
	hdr->ttl=64;
	hdr->protocol=IP_TCP;
	hdr->saddr=srcIP,
	hdr->daddr=dstIP;
	
	hdr->saddr=htonl(hdr->saddr);
	hdr->daddr=htonl(hdr->daddr);
	hdr->tot_len=htons(hdr->tot_len);
	
	hdr->checkSum=0;
	hdr->checkSum=checkSum((char*)hdr,sizeof(ip_hdr));
	return 0;
}

校验和的计算代码是从linux源码copy来的..应该不会错。
但是！
wireshark抓包永远是校验和错误的..whywhywhy....

[碼上道]

这个不是x86构架的吧，大小端是否正确？调试一下就知道哪儿错了