static int sniffer_print_nlmsg(struct nlmsghdr *nlh, char *buf, int buf_len)
{
int ret = 0;
switch (nlh->nlmsg_type)
{
case SNIFFER_NLTYPE_KINFO:
if (buf_len < sizeof(struct sniffer_match_info))
{
printf("Invalid packet info message\n");
break;
}
printinfo((struct sniffer_match_info *)buf);
break;
case SNIFFER_NLTYPE_KCOUNT:
printcount((struct sniffer_match_count *)buf);
ret = 1; /* kernel stoped, so we exit */
break;
case SNIFFER_NLTYPE_KFILTER:
printfilter((struct sniffer_filter *)buf);
ret = 1;
break;
default:
printf("Warning:receive an unknown messge from kernel\n");
break;
}
return ret;
}
Filter*
compile(Filter *f)
{
if(f == nil)
return f;
/* fill in the missing header filters */
f = complete(f, nil);
/* constant folding */
f = optimize(f);
if(!toflag)
printfilter(f, "after optimize");
/* protocol specific compilations */
_compile(f, nil);
/* at this point, the root had better be the root proto */
if(findbogus(f)){
fprint(2, "bogus filter\n");
exits("bad filter");
}
return f;
}