最近在做网络流量的分析，用到了winPcap。
winPcap的文档中有个源程序,如下：#include <stdlib.h>
#include <stdio.h>#include <pcap.h>void usage();void dispatcher_handler(u_char *, const struct pcap_pkthdr *, const u_char *);
void main(int argc, char **argv)
{
pcap_t *fp;
char errbuf[PCAP_ERRBUF_SIZE];
struct timeval st_ts;
u_int netmask;
struct bpf_program fcode;
/* Check the validity of the command line */
if (argc != 2)
{
usage();
return;
}
/* Open the output adapter */
if ( (fp= pcap_open(argv[1], 100, PCAP_OPENFLAG_PROMISCUOUS, 1000, NULL, errbuf) ) == NULL)
{
fprintf(stderr,"\nUnable to open adapter %s.\n", errbuf);
return;
} /* Don't care about netmask, it won't be used for this filter */
netmask=0xffffff; //compile the filter
if (pcap_compile(fp, &fcode, "tcp", 1, netmask) <0 )
{
fprintf(stderr,"\nUnable to compile the packet filter. Check the syntax.\n");
/* Free the device list */
return;
}
//set the filter
if (pcap_setfilter(fp, &fcode)<0)
{
fprintf(stderr,"\nError setting the filter.\n");
pcap_close(fp);
/* Free the device list */
return;
} /* Put the interface in statstics mode */
if (pcap_setmode(fp, MODE_STAT)<0)
{
fprintf(stderr,"\nError setting the mode.\n");
pcap_close(fp);
/* Free the device list */
return;
}
printf("TCP traffic summary:\n"); /* Start the main loop */
pcap_loop(fp, 0, dispatcher_handler, (PUCHAR)&st_ts); pcap_close(fp);
return;
}void dispatcher_handler(u_char *state, const struct pcap_pkthdr *header, const u_char *pkt_data)
{
struct timeval *old_ts = (struct timeval *)state;
u_int delay;
LARGE_INTEGER Bps,Pps;
struct tm *ltime;
char timestr[16];
time_t local_tv_sec; /* Calculate the delay in microseconds from the last sample. */
/* This value is obtained from the timestamp that the associated with the sample. */
delay=(header->ts.tv_sec - old_ts->tv_sec) * 1000000 - old_ts->tv_usec + header->ts.tv_usec;
/* Get the number of Bits per second */
Bps.QuadPart=(((*(LONGLONG*)(pkt_data + 8)) * 8 * 1000000) / (delay));
/* ^ ^
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converts bytes in bits -- |
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delay is expressed in microseconds --
*/ /* Get the number of Packets per second */
Pps.QuadPart=(((*(LONGLONG*)(pkt_data)) * 1000000) / (delay)); /* Convert the timestamp to readable format */
local_tv_sec = header->ts.tv_sec;
ltime=localtime(&local_tv_sec);
strftime( timestr, sizeof timestr, "%H:%M:%S", ltime); /* Print timestamp*/
printf("%s ", timestr); /* Print the samples */
printf("BPS=%I64u ", Bps.QuadPart);
printf("PPS=%I64u\n", Pps.QuadPart); //store current timestamp
old_ts->tv_sec=header->ts.tv_sec;
old_ts->tv_usec=header->ts.tv_usec;
}
void usage()
{
printf("\nShows the TCP traffic load, in bits per second and packets per second.\nCopyright (C) 2002 Loris Degioanni.\n");
printf("\nUsage:\n");
printf("\t tcptop adapter\n");
printf("\t You can use \"WinDump -D\" if you don't know the name of your adapters.\n"); exit(0);
}无论我怎么改pcap_compile(fp, &fcode, "tcp", 1, netmask)中的过滤规则（比如将"tcp"改为"arp"），我所得到的流量
都没多大的改变，请问这是什么问题啊？
谢谢
winPcap的文档中有个源程序,如下：#include <stdlib.h>
#include <stdio.h>#include <pcap.h>void usage();void dispatcher_handler(u_char *, const struct pcap_pkthdr *, const u_char *);
void main(int argc, char **argv)
{
pcap_t *fp;
char errbuf[PCAP_ERRBUF_SIZE];
struct timeval st_ts;
u_int netmask;
struct bpf_program fcode;
/* Check the validity of the command line */
if (argc != 2)
{
usage();
return;
}
/* Open the output adapter */
if ( (fp= pcap_open(argv[1], 100, PCAP_OPENFLAG_PROMISCUOUS, 1000, NULL, errbuf) ) == NULL)
{
fprintf(stderr,"\nUnable to open adapter %s.\n", errbuf);
return;
} /* Don't care about netmask, it won't be used for this filter */
netmask=0xffffff; //compile the filter
if (pcap_compile(fp, &fcode, "tcp", 1, netmask) <0 )
{
fprintf(stderr,"\nUnable to compile the packet filter. Check the syntax.\n");
/* Free the device list */
return;
}
//set the filter
if (pcap_setfilter(fp, &fcode)<0)
{
fprintf(stderr,"\nError setting the filter.\n");
pcap_close(fp);
/* Free the device list */
return;
} /* Put the interface in statstics mode */
if (pcap_setmode(fp, MODE_STAT)<0)
{
fprintf(stderr,"\nError setting the mode.\n");
pcap_close(fp);
/* Free the device list */
return;
}
printf("TCP traffic summary:\n"); /* Start the main loop */
pcap_loop(fp, 0, dispatcher_handler, (PUCHAR)&st_ts); pcap_close(fp);
return;
}void dispatcher_handler(u_char *state, const struct pcap_pkthdr *header, const u_char *pkt_data)
{
struct timeval *old_ts = (struct timeval *)state;
u_int delay;
LARGE_INTEGER Bps,Pps;
struct tm *ltime;
char timestr[16];
time_t local_tv_sec; /* Calculate the delay in microseconds from the last sample. */
/* This value is obtained from the timestamp that the associated with the sample. */
delay=(header->ts.tv_sec - old_ts->tv_sec) * 1000000 - old_ts->tv_usec + header->ts.tv_usec;
/* Get the number of Bits per second */
Bps.QuadPart=(((*(LONGLONG*)(pkt_data + 8)) * 8 * 1000000) / (delay));
/* ^ ^
| |
| |
| |
converts bytes in bits -- |
|
delay is expressed in microseconds --
*/ /* Get the number of Packets per second */
Pps.QuadPart=(((*(LONGLONG*)(pkt_data)) * 1000000) / (delay)); /* Convert the timestamp to readable format */
local_tv_sec = header->ts.tv_sec;
ltime=localtime(&local_tv_sec);
strftime( timestr, sizeof timestr, "%H:%M:%S", ltime); /* Print timestamp*/
printf("%s ", timestr); /* Print the samples */
printf("BPS=%I64u ", Bps.QuadPart);
printf("PPS=%I64u\n", Pps.QuadPart); //store current timestamp
old_ts->tv_sec=header->ts.tv_sec;
old_ts->tv_usec=header->ts.tv_usec;
}
void usage()
{
printf("\nShows the TCP traffic load, in bits per second and packets per second.\nCopyright (C) 2002 Loris Degioanni.\n");
printf("\nUsage:\n");
printf("\t tcptop adapter\n");
printf("\t You can use \"WinDump -D\" if you don't know the name of your adapters.\n"); exit(0);
}无论我怎么改pcap_compile(fp, &fcode, "tcp", 1, netmask)中的过滤规则（比如将"tcp"改为"arp"），我所得到的流量
都没多大的改变，请问这是什么问题啊？
谢谢
为什么在回掉函数中计算每秒收到的bit数用这句话来计算啊：
Bps.QuadPart=(((*(LONGLONG*)(pkt_data + 8)) * 8 * 1000000) / (delay));