int
icmp_generic_decode (unsigned char * buffer, size_t bufsize,
struct ip **ipp, icmphdr_t ** icmpp)
{
size_t hlen;
unsigned short cksum;
struct ip *ip;
icmphdr_t *icmp;
/* IP header */
ip = (struct ip *) buffer;
hlen = ip->ip_hl << 2;
if (bufsize < hlen + ICMP_MINLEN)
return -1;
/* ICMP header */
icmp = (icmphdr_t *) (buffer + hlen);
/* Prepare return values */
*ipp = ip;
*icmpp = icmp;
/* Recompute checksum */
cksum = icmp->icmp_cksum;
icmp->icmp_cksum = 0;
icmp->icmp_cksum = icmp_cksum ((unsigned char *) icmp, bufsize - hlen);
if (icmp->icmp_cksum != cksum)
return 1;
return 0;
}
/*******************************************************************************
函数名称 : healthy_check_set_ping_data
功能描述 : ping 报数据组装函数
输入参数 : hc_ping_s *ping_cfg: 当前检测ip 配置
u32 seqno : ping 报序号
输出参数 : 无
返回值 : 无
--------------------------------------------------------------------------------
最近一次修改记录 :
修改作者 : 王宗发
修改目的 : 新增函数
修改日期 : 20101020
********************************************************************************/
void healthy_check_set_ping_data(hc_ping_s *ping_cfg, u32 seqno)
{
struct timeval tv;
struct icmp6_hdr *icmp6 = NULL;
gettimeofday (&tv, NULL);
ping_cfg->start_time = tv;
icmp6 = (struct icmp6_hdr *) ping_cfg->ping_buf;
icmp6->icmp6_cksum = 0;
icmp6->icmp6_seq = seqno + 1;
/*在icmp报中记录发送时间*/
memcpy((u8 *)icmp6 + sizeof(struct icmp6_hdr), &tv, sizeof(struct timeval));
icmp6->icmp6_cksum = icmp_cksum ((u8 *)(ping_cfg->ping_buf), (s32)(ping_cfg->buf_len));
return;
}
int
icmp_generic_encode (unsigned char * buffer, size_t bufsize, int type, int ident,
int seqno)
{
icmphdr_t *icmp;
if (bufsize < ICMP_MINLEN)
return -1;
icmp = (icmphdr_t *) buffer;
icmp->icmp_type = type;
icmp->icmp_code = 0;
icmp->icmp_cksum = 0;
icmp->icmp_seq = htons (seqno);
icmp->icmp_id = htons (ident);
icmp->icmp_cksum = icmp_cksum (buffer, bufsize);
return 0;
}
static void icmp_unexpect_ttl(uint8_t *icmp_packet, struct ofputil_packet_in *pi, uint8_t header_len, uint8_t type, uint8_t code, uint32_t info)
{
uint16_t total_len = sizeof(struct iphdr) + sizeof(struct icmphdr) + header_len + 8;
uint8_t *old_payload = pi->packet;
struct ethhdr * old_eth = (struct ethhdr *)old_payload;
struct ethhdr * new_eth = (struct ethhdr *)icmp_packet;
memcpy(new_eth->h_source, old_eth->h_dest, sizeof(struct eth_addr));
memcpy(new_eth->h_dest, old_eth->h_source, sizeof(struct eth_addr));
new_eth->h_proto = htons(ETH_P_IP);
struct iphdr * old_ipv4 = (struct iphdr *) (old_eth + 1);
struct iphdr * new_ipv4 = (struct iphdr *) (new_eth + 1);
new_ipv4->ihl = 0x5;
new_ipv4->version = 0x4;
new_ipv4->tos = old_ipv4->tos;
new_ipv4->tot_len = htons(total_len);
ip_ident_seed += 27;
new_ipv4->id = htons(ip_ident_seed);
new_ipv4->frag_off = 0;
new_ipv4->ttl = 64;
new_ipv4->protocol = IPPROTO_ICMP;
new_ipv4->check = 0;
new_ipv4->saddr = saddr.s_addr;
new_ipv4->daddr = old_ipv4->saddr;
new_ipv4->check = ipv4_cksum(new_ipv4);
struct icmphdr * icmp = (struct icmphdr *) (new_ipv4 + 1);
icmp->type = type;
icmp->code = code;
icmp->un.gateway = info;
icmp->checksum = 0;
uint8_t *payload = (uint8_t *)(icmp + 1);
old_payload += sizeof(struct ethhdr);
memcpy(payload, old_payload, 8 + header_len);
icmp->checksum = icmp_cksum(total_len - sizeof(struct iphdr), (struct icmphdr const*) icmp);
return;
}
