/*
 * This is to parse the DAG card trace file into text records.
 *
 */

#define _LARGEFILE_SOURCE
#define _LARGEFILE64_SOURCE
#define _FILE_OFFSET_BITS 64
#define _GNU_SOURCE

#include <unistd.h>
#include <netinet/in.h>
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <math.h>

typedef struct __attribute__((packed)) _TRACE_RECORD_
{
    uint32_t tlL; /* 4 bytes, timestamp lower part */
    uint32_t tlH; /* 4 bytes, timestamp higher part */
    uint8_t stuff[22];    /* 22 bytes, unkown */
    uint16_t ll; /* 2 bytes */
    /* Here comes the IP header */
    unsigned short ip_version : 4; /* 1 byte */
    unsigned short ip_ihl : 4;
    uint8_t ip_tos;  /* 1 byte */
    uint16_t ip_tlen;  /* 2 byte */
    uint16_t ip_id;   /* 2 byte */
    unsigned short ip_flags : 4; /* 2 bytes */
    unsigned short ip_offset : 12;
    uint8_t ip_ttl; /* 1 byte */
    uint8_t ip_protocol; /* 1 byte */
    uint16_t ip_checksum; /* 2 bytes */
    uint32_t ip_src; /* 4 bytes */
    uint32_t ip_dst; /* 4 bytes */
    /* Here comes the TCP header if it is one */
    uint16_t sport; /* 2 bytes */
    uint16_t dport; /* 2 bytes */
    uint32_t tcp_seqno; /* 4 bytes */
    uint32_t tcp_ackno; /* 4 bytes */
    uint8_t tcp_offx2;       /* data offset, rsvd */
#define TH_OFF(th)  (((th)->th_offx2 & 0xf0) >> 4)
    uint8_t tcp_flags;
#define TH_FIN  0x01
#define TH_SYN  0x02
#define TH_RST  0x04
#define TH_PUSH 0x08
#define TH_ACK  0x10
#define TH_URG  0x20
#define TH_ECNECHO  0x40    /* ECN Echo */
#define TH_CWR      0x80    /* ECN Cwnd Reduced */
    uint16_t tcp_win; /* 2 bytes */
} TRACE_RECORD;

int main(int argc, const char** argv)
{
    const double CFact = pow(2., 32.);

    int fData;

#define RECORD_POOL_SIZE 10000

    TRACE_RECORD record_pool[RECORD_POOL_SIZE];
    TRACE_RECORD *record;
    int records_left;

    char tsrc[16], tdst[16];

    double timestamp;

    if (argc != 2) {
        printf("Usage: %s <dag trace file name>\n", argv[0]);
        return 0;
    }

    fData = open64(argv[1], O_RDONLY);
    if (fData <=0) {
        printf("Error opening file\n");
        return -1;
    }

    while ((records_left=read(fData, &record_pool, sizeof(record_pool))) > 0) {
        records_left /= sizeof(TRACE_RECORD);
        record = record_pool;
        while (records_left > 0) {
            timestamp = ((double)record->tlH) + ((double)record->tlL)/CFact;
            record->ll = ntohs(record->ll);

            if (record->ll == 0x0800) {

                record->ip_tlen = ntohs(record->ip_tlen);
                record->ip_id = ntohs(record->ip_id);
                record->ip_src = ntohl(record->ip_src);
                record->ip_dst = ntohl(record->ip_dst);

                sprintf(tsrc, "%d.%d.%d.%d",(record->ip_src>>24)&0xff,(record->ip_src>>16)&0xff,(record->ip_src>>8)&0xff,record->ip_src&0xff);
                sprintf(tdst, "%d.%d.%d.%d",(record->ip_dst>>24)&0xff,(record->ip_dst>>16)&0xff,(record->ip_dst>>8)&0xff,record->ip_dst&0xff);
                if (record->ip_protocol == 6) {
                    record->sport = ntohs(record->sport);
                    record->dport = ntohs(record->dport);
                    record->tcp_seqno = ntohl(record->tcp_seqno);
                    record->tcp_ackno = ntohl(record->tcp_ackno);
                    record->tcp_win = ntohs(record->tcp_win);
    
                    /* TCP packet */
                    printf("%.8f\t%4d\t%5d\t%3d\t%2d\t%u\t%u\t%15s\t%15s\t%5d\t%5d\t%u\t%u\t%d\t%d\t%d\t%d\n",
                        timestamp, record->ip_tlen, record->ip_id, 
                        record->ip_ttl, record->ip_protocol,
                        record->ip_src, record->ip_dst,
                        tsrc, tdst,
                        record->sport, record->dport,
                        record->tcp_seqno, record->tcp_ackno,
                        ((record->tcp_flags & TH_ACK) != 0) ,
                        ((record->tcp_flags & TH_SYN) != 0) ,
                        ((record->tcp_flags & TH_RST) != 0) ,
                        record->tcp_win);
                } else if (record->ip_protocol == 17) {
                    record->sport = ntohs(record->sport);
                    record->dport = ntohs(record->dport);

                    /* UDP packet */
                    printf("%.8f\t%4d\t%5d\t%3d\t%2d\t%u\t%u\t%15s\t%15s\t%5d\t%5d\n",
                        timestamp, record->ip_tlen, record->ip_id, 
                        record->ip_ttl, record->ip_protocol,
                        record->ip_src, record->ip_dst,
                        tsrc, tdst,
                        record->sport, record->dport);
                } else {
                    /* Other packets */
                    printf("%.8f\t%4d\t%5d\t%3d\t%2d\t%u\t%u\t%15s\t%15s\n",
                        timestamp, record->ip_tlen, record->ip_id, 
                        record->ip_ttl, record->ip_protocol,
                        record->ip_src, record->ip_dst,
                        tsrc, tdst);
                }
            }

            records_left--;
            record ++;
        }
    }

    close(fData);

    return 0;
}