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/*
* SNAP.
*/
#include <u.h>
#include <libc.h>
#include <ip.h>
#include "dat.h"
#include "protos.h"
enum
{
Oorg,
Oet,
OuiEther = 0,
OuiCisco = 0xc,
OuiCisco90 = 0xf8,
OuiRfc2684 = 0x80c2,
OuiAppletalk = 0x80007,
};
static Mux p_mux[] =
{
{"ip", 0x0800, } ,
{"arp", 0x0806, } ,
{"rarp", 0x0806, } ,
{"ip6", 0x86dd, } ,
{"pppoe_disc", 0x8863, },
{"pppoe_sess", 0x8864, },
{"eapol", 0x888e, },
{ 0 }
};
typedef struct Hdr Hdr;
struct Hdr
{
uchar org[3];
uchar et[2];
};
static Field p_fields[] =
{
{ "org", Fnum, Oorg, "org" },
{ "et", Fnum, Oet, "et" },
{ 0 }
};
static void
p_compile(Filter *f)
{
Mux *m;
if(f->op == '='){
compile_cmp(snap.name, f, p_fields);
return;
}
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 = Oet;
return;
}
}
sysfatal("unknown snap field or protocol: %s", f->s);
}
static int
p_filter(Filter *f, Msg *m)
{
Hdr *h;
if(m->pe - m->ps < sizeof(Hdr))
return 0;
h = (Hdr*)m->ps;
m->ps += 5;
switch(f->subop){
case Oorg:
return f->ulv == Net3(h->org);
case Oet:
return f->ulv == NetS(h->et);
}
return 0;
}
static int
p_seprint(Msg *m)
{
Hdr *h;
if(m->pe - m->ps < sizeof(Hdr))
return 0;
h = (Hdr*)m->ps;
m->ps += 5;
demux(p_mux, NetS(h->et), NetS(h->et), m, &dump);
m->p = seprint(m->p, m->e, "org=%06x et=%04x", Net3(h->org), NetS(h->et));
return 0;
}
Proto snap =
{
"snap",
p_compile,
p_filter,
p_seprint,
p_mux,
nil,
nil,
defaultframer
};
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