tcp_tproxy.c
/*
* # iptables -t mangle -N DIVERT
* # iptables -t mangle -A PREROUTING -p tcp -m socket -j DIVERT
* # iptables -t mangle -A DIVERT -j MARK --set-mark 1
* # iptables -t mangle -A DIVERT -j ACCEPT
* # ip rule add fwmark 1 lookup 100
* # ip route add local 0.0.0.0/0 dev lo table 100
* # iptables -t mangle -A PREROUTING -p tcp --dport 80 -j TPROXY --tproxy-mark 0x1/0x1 --on-port 9401
*
*/
#include <stdio.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <sys/types.h>
#include <string.h>
#include <errno.h>
#include <sys/ioctl.h>
#include <limits.h>
#include <linux/netfilter_ipv4.h>
int handle_client (int c, struct sockaddr_in *clntaddr);
int tunnel_transparently (int c, struct sockaddr_in *clntaddr, struct sockaddr_in *dstaddr);
int main (int argc, char **argv)
{
int s;
int c;
short int port;
struct sockaddr_in servaddr;
struct sockaddr_in clntaddr;
int n;
int ret;
struct msghdr msg;
char cntrlbuf[64];
struct iovec iov[1];
char *endptr;
if (argc < 2)
{
printf ("usage: %s <port>\n", argv[0]);
return -1;
}
port = strtol (argv[1], &endptr, 0);
if (*endptr || port <= 0)
{
fprintf (stderr, "invalid port number %s.\n", argv[1]);
return -2;
}
if ((s = socket (AF_INET, SOCK_STREAM, 0)) < 0)
{
fprintf (stderr, "error creating listening socket.\n");
return -3;
}
n=1;
setsockopt(s, SOL_SOCKET, SO_REUSEADDR, &n, sizeof(n));
setsockopt(s, SOL_SOCKET, SO_BROADCAST, &n, sizeof(n));
/* Enable TPROXY IP preservation */
n=1;
ret =
setsockopt (s, SOL_IP, IP_TRANSPARENT, &n, sizeof(int));
if (ret != 0)
{
fprintf (stderr, "error setting transparency for listening socket. err (#%d %s)\n", errno, strerror(errno));
close (s);
return -4;
}
memset (&servaddr, 0, sizeof (servaddr));
servaddr.sin_family = AF_INET;
servaddr.sin_addr.s_addr = htonl (INADDR_ANY);
servaddr.sin_port = htons (port);
if (bind (s, (struct sockaddr *) &servaddr, sizeof (servaddr)) < 0)
{
fprintf (stderr, "error calling bind()\n");
return -6;
}
listen (s, 1024);
while (1)
{
n=sizeof(clntaddr);
if ((c = accept (s, (struct sockaddr *)&clntaddr, &n)) < 0)
{
fprintf (stderr, "error calling accept()\n");
break;
}
handle_client (c, &clntaddr);
}
close (s);
return 0;
}
int handle_client (int c, struct sockaddr_in *clntaddr)
{
struct sockaddr_in dstaddr={0,};
int ret;
int n;
/* get original destination address */
n=
sizeof(struct sockaddr_in);
ret = getsockopt (c, SOL_IP, IP_ORIGDSTADDR, &dstaddr, &n); // IP_ORIGDSTADDR = 20
//ret = getsockopt (c, SOL_IP, SO_ORIGINAL_DST, &dstaddr, &n); // SO_ORIGINAL_DST = 80
if (ret != 0)
{
fprintf (stderr, "error getting original destination address. err (#%d %s)\n", errno, strerror(errno));
close (c);
return -1;
}
dstaddr.sin_family = AF_INET;
printf ("original destination address %X:%d\n", dstaddr.sin_addr.s_addr, dstaddr.sin_port);
ret = tunnel_transparently (c, clntaddr, &dstaddr);
if (ret <= 0)
{
close (c);
return -2;
}
close (c);
return 0;
}
int tunnel_transparently (int c, struct sockaddr_in *clntaddr, struct sockaddr_in *dstaddr)
{
int d;
int n;
int ret;
if (clntaddr == NULL || dstaddr == NULL)
{
return -1;
}
d = socket (AF_INET, SOCK_STREAM, 0);
if (d == -1)
{
fprintf (stderr, "error creating socket (#%d %s)\n", errno, strerror(errno));
return -2;
}
n=1;
ret =
setsockopt (d, SOL_IP, IP_TRANSPARENT, &n, sizeof(int));
if (ret != 0)
{
fprintf (stderr, "error setting transparency towards destination. err (#%d %s)\n", errno, strerror(errno));
close (d);
return -3;
}
ret =
bind (d, (struct sockaddr *)clntaddr, sizeof (struct sockaddr_in));
if (ret != 0)
{
fprintf (stderr, "error binding to client . err (#%d %s)\n", errno, strerror(errno));
close (d);
return -4;
}
ret = connect (d, (struct sockaddr *)dstaddr, sizeof (*dstaddr));
if (ret != 0)
{
fprintf (stderr, "error connecting to detination. err (#%d %s)\n", errno, strerror(errno));
close (d);
return -5;
}
// TODO: send / recv
//
close (d);
return 0;
}
Makefile
CFLAGS += -g
all: tcp_tproxy udp_tproxy
tcp_tproxy: tcp_tproxy.o
$(CC) -o $@ tcp_tproxy.o
udp_tproxy: udp_tproxy.o
$(CC) -o $@ udp_tproxy.o
clean:
-@rm *.o
distclean: clean
-@rm tcp_tproxy udp_tproxy
2. Most brand new HP servers come with an information tag attached. Printed on the tag is the server serial number and Integrated Lights Out access information including factory set username and password. 
3. The easiest way to access the ILO configuration utility is during the POST by pressing F8 when prompted.
4. First access the Network menu, disable DHCP and change the DNS name 
5. Then configure your static ip settings 
6. Next, set the Administrator password or create new user. 
7. Note that the username and password are both case sensitive. Select Exit to save and reset ILO with the new settings. Test access to the ILO web interface. 
