Hello All,
I am a student in Korea ...
I have a question about IPIP tunnel with using new_tunnel module....
I want to extract outer source address, outer dest address,
inner source address and inner dest address each....
I looked a tunneled packet using "SOCK_PACKET" ...
I tried to extract them from that packet ...
I can get outer source and destination address from it ...
But
when I try to get inner source and destination address from it,
my program is terminated with "Segmentation Fault"...
Source code in my program
===============================================================
boolean isTunneledPkt(struct strbuf *data, u32 *outsrc, u32 *outdst,
u32 *insrc, u32 *indst)
{
int ip_hdr_len, i;
u32 ip_outsrc, ip_outdst, ip_insrc, ip_indst;
if ((data->len < 54) || (data->buf[23] != IPPROTO_IPIP) ||
(data->buf[12] != 8) || (data->buf[13] != 0)) {
return(FALSE);
}
mip3dbg(("Tunneled_Packet._%d\n", (unsigned char)data->buf[23]));
/* Outer IP header */
ip_outsrc = 0;
for (i = 26; i < 30; i++)
ip_outsrc = (ip_outsrc << 8) | (0xff & data->buf[i]);
*outsrc = htonl(ip_outsrc);
ip_outdst = 0;
for (i = 30; i < 34; i++)
ip_outdst = (ip_outdst << 8) | (0xff & data->buf[i]);
*outdst = htonl(ip_outdst);
/* Inner IP header */
ip_insrc = 0;
for (i = 46; i < 50; i++)
ip_insrc = (ip_insrc << 8) | (0xff & data->buf[i]);
*insrc = htonl(ip_insrc);
ip_indst = 0;
for (i = 50; i < 54; i++)
ip_indst = (ip_indst << 8) | (0xff & data->buf[i]);
*indst = htonl(ip_indst);
return(TRUE);
}
data contains a packet with Ethernet Header ....
Any comments will be appreciated ...
Thanks in advance ...
:.˛mkabzwmb˛mb{ay ʇڙ,jfhz_
