/*
* This program demonstrate SOCK_PACK call.
* Thanks Linux. Thanks Alan Cox
* derived from/usr/src/redhat/SOURCES/dosemu-0.66.7/src/dosext/net/net/libpacket.c
* compile method： cc capturer.c -o capturer
*/
/*
* Alan Cox raw code
*/
/*
* SOCK_PACKET support.
* Placed under the GNU LGPL.
*
* First cut at a library of handy support routines. Comments, additions
* and bug fixes greatfully received.
*
* (c) 1994 Alan Cox [email protected] GW4PTS@GB7SWN
*/
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
/*#if __GLIBC__ > 1*/
#include
#include
/*#else
#include
#include
#endif*/
#include
#include
/*
* Obtain a file handle on a raw ethernet type. In actual fact
* you can also request the dummy types for AX.25 or 802.3 also
*
* -1 indicates an error
* 0 or higher is a file descriptor which we have set non blocking
*
* WARNING: It is ok to listen to a service the system is using (eg arp)
* but don t try and run a user mode stack on the same service or all
* hell will break loose.
*/
int
OpenNetworkType(unsigned short netid)
{
int s = socket(AF_INET, SOCK_PACKET, htons(netid)).
if (s == -1)
return -1.
fcntl(s, F_SETFL, O_NDELAY).
return s.
}
/*
* Close a file handle to a raw packet type.
*/
void
CloseNetworkLink(int sock)
{
close(sock).
}
/*
* Write a packet to the network. You have to give a device to
* this function. This is a device name (eg eth0 for the first
* ethernet card). Please don t assume eth0, make it configurable
* - plip is ethernet like but not eth0, ditto for the de600 s.
*
* Return: -1 is an error
* otherwise bytes written.
*/
int
WriteToNetwork(int sock, const char *device, const char *data, int len)
{
struct sockaddr sa.
sa.sa_family = AF_INET.
strcpy(sa.sa_data, device).
return (sendto(sock, data, len, 0, &.sa, sizeof(sa))).
}
/*
* Read a packet from the network. The device parameter will
* be filled in by this routine (make it 32 bytes or more).
* If you wish to work with one interface only you must filter
* yourself. Remember to make your buffer big enough for your
* data. Oversized packets will be truncated.
*
* Return:
* -1 Error
* otherwise Size of packet received.
*/
int
ReadFromNetwork(int sock, char *device, char *data, int len)
{
struct sockaddr sa.
int sz = sizeof(sa).
int error.
error = recvfrom(sock, data, len, 0, &.sa, &.sz).
if (error == -1)
return -1.
strcpy(device, sa.sa_data).
return error. /* Actually size of received packet */
}
/*
* Handy support routines.
*/
/*
* Obtain the hardware address of an interface.
* addr should be a buffer of 8 bytes or more.
*
* Return:
* 0 Success, buffer holds data.
* -1 Error.
*/
/*
* NET2 or NET3 - work for both.
*/
#if defined(OLD_SIOCGIFHWADDR) || (KERNEL_VERSION >= 1003038)
#define NET3
#endif
int
GetDeviceHardwareAddress(char *device, char *addr)
{
int s = socket(AF_INET, SOCK_DGRAM, 0).
struct ifreq req.
int err.
strcpy(req.ifr_name, device).
err = ioctl(s, SIOCGIFHWADDR, &.req).
close(s). /* Thanks Rob. for noticing this */
if (err == -1)
return err.
memcpy(addr, req.ifr_hwaddr.sa_data,8).
return 0.
}
/*
* Obtain the maximum packet size on an interface.
*
* Return:
* >0 Return is the mtu of the interface
* -1 Error.
*/
int
GetDeviceMTU(char *device)
{
int s = socket(AF_INET, SOCK_DGRAM, 0).
struct ifreq req.
int err.
strcpy(req.ifr_name, device).
err = ioctl(s, SIOCGIFMTU, &.req).
close(s). /* So I ll add this one as well. Ok Alan? - Rob */
if (err == -1)
return err.
return req.ifr_mtu.
}
#define data_packet_len 1514
int
main(int argc ,char *argv[])
{
char devicename_rec[32].
unsigned char data[data_packet_len].
int netid=0x03,sock_h=0,i=0,count_rec=0.
if ((sock_h=OpenNetworkType(netid))<0)
{
printf("Can t open net_dectype %d \n",netid).
return -1.
}
printf("Ready to receive 0x%x data packet...\n",netid).
for(..) {
if (ReadFromNetwork(sock_h,devicename_rec,data,data_packet_len)>0) {
printf("Received Packet = %d\n", count_rec) .
for (i=0.i<100.i )
printf("%2x|",data[i]).
printf("\n").
}
}
} |