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#include <stdio.h>
#include "libpacketdump.h"
#define LE(lhs,n) \
do { \
uint64_t num=0; \
int size=0; \
if ((offset+n)>len*8) return; \
if (n>16) { \
num=htonl(*(uint32_t*)(packet+offset/8));\
size = 32;\
} else if (n>8) { \
num=htons(*(uint16_t*)(packet+offset/8));\
size = 16; \
} else { \
num=*(uint8_t*)(packet+offset/8); \
size = 8; \
} \
num=num>>(size - (n + (offset % 8))); \
offset+=n; \
lhs=num&((1<<(n))-1); \
} while(0)
DLLEXPORT void decode(int link_type UNUSED,const char *packet,unsigned len)
{
unsigned int offset=0;
int value;
uint16_t ethertype;
LE(value, 3); printf(" VLAN: User Priority: %d\n", value);
LE(value, 1); printf(" VLAN: Format Indicator: %d\n", value);
LE(value, 12); printf(" VLAN: ID: %d\n", value);
LE(value, 16); printf(" VLAN: EtherType: 0x%04x\n", (uint16_t)value);
ethertype = (uint16_t) value;
decode_next(packet + 4, len - 4, "eth", ethertype);
return;
}
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