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#include <u.h>
#include <libc.h>
#include <ip.h>
#include "dat.h"
#include "protos.h"
typedef struct Hdr Hdr;
struct Hdr
{
uchar vi; /* version */
uchar type;
uchar len[2]; /* length of data following this header */
};
enum
{
EAPOLHDR= 4, /* sizeof(Hdr) */
/* eapol types */
Eap = 0,
Start,
Logoff,
Key,
AsfAlert,
};
enum
{
Ot, /* type */
};
static Mux p_mux[] =
{
{ "eap", Eap, },
{ "eapol_start", Start, },
{ "eapol_logoff", Logoff, },
{ "eapol_key", Key, },
{ "asf_alert", AsfAlert, },
{ 0 }
};
static void
p_compile(Filter *f)
{
Mux *m;
for(m = p_mux; m->name != nil; m++)
if(strcmp(f->s, m->name) == 0){
f->pr = m->pr;
f->ulv = m->val;
f->subop = Ot;
return;
}
sysfatal("unknown eapol field or type: %s", f->s);
}
static int
p_filter(Filter *f, Msg *m)
{
Hdr *h;
if(m->pe - m->ps < EAPOLHDR)
return 0;
h = (Hdr*)m->ps;
/* len does not include header */
m->ps += EAPOLHDR;
switch(f->subop){
case Ot:
return h->type == f->ulv;
}
return 0;
}
static char*
op(int i)
{
static char x[20];
switch(i){
case Eap:
return "Eap";
case Start:
return "Start";
case Logoff:
return "Logoff";
case Key:
return "Key";
case AsfAlert:
return "AsfAlert";
default:
sprint(x, "%1d", i);
return x;
}
}
static int
p_seprint(Msg *m)
{
Hdr *h;
int len;
if(m->pe - m->ps < EAPOLHDR)
return -1;
h = (Hdr*)m->ps;
/* len does not include header */
m->ps += EAPOLHDR;
/* truncate the message if there's extra */
len = NetS(h->len);
if(m->ps + len < m->pe)
m->pe = m->ps + len;
else if(m->ps+len > m->pe)
return -1;
/* next protocol depending on type*/
demux(p_mux, h->type, h->type, m, &dump);
m->p = seprint(m->p, m->e, "type=%s version=%1d datalen=%1d",
op(h->type), h->vi, len);
return 0;
}
Proto eapol =
{
"eapol",
p_compile,
p_filter,
p_seprint,
p_mux,
"%lud",
nil,
defaultframer,
};
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