1 17b19538 2008-07-24 rsc /* 
  2 17b19538 2008-07-24 rsc  * SNAP.
  3 17b19538 2008-07-24 rsc  */
  4 17b19538 2008-07-24 rsc 
  5 17b19538 2008-07-24 rsc #include <u.h>
  6 17b19538 2008-07-24 rsc #include <libc.h>
  7 17b19538 2008-07-24 rsc #include <ip.h>
  8 17b19538 2008-07-24 rsc #include "dat.h"
  9 17b19538 2008-07-24 rsc #include "protos.h"
 10 17b19538 2008-07-24 rsc 
 11 17b19538 2008-07-24 rsc enum
 12 17b19538 2008-07-24 rsc {
 13 17b19538 2008-07-24 rsc 	Oorg,
 14 17b19538 2008-07-24 rsc 	Oet,
 15 17b19538 2008-07-24 rsc 	
 16 17b19538 2008-07-24 rsc 	OuiEther = 0,
 17 17b19538 2008-07-24 rsc 	OuiCisco = 0xc,
 18 17b19538 2008-07-24 rsc 	OuiCisco90 = 0xf8,
 19 17b19538 2008-07-24 rsc 	OuiRfc2684 = 0x80c2,
 20 17b19538 2008-07-24 rsc 	OuiAppletalk = 0x80007,
 21 17b19538 2008-07-24 rsc };
 22 17b19538 2008-07-24 rsc 
 23 17b19538 2008-07-24 rsc static Mux p_mux[] =
 24 17b19538 2008-07-24 rsc {
 25 17b19538 2008-07-24 rsc 	{"ip",		0x0800,	} ,
 26 17b19538 2008-07-24 rsc 	{"arp",		0x0806,	} ,
 27 17b19538 2008-07-24 rsc 	{"rarp",	0x0806,	} ,
 28 17b19538 2008-07-24 rsc 	{"ip6", 	0x86dd, } ,
 29 17b19538 2008-07-24 rsc 	{"pppoe_disc",	0x8863, },
 30 17b19538 2008-07-24 rsc 	{"pppoe_sess",	0x8864, },
 31 17b19538 2008-07-24 rsc 	{"eapol",	0x888e, },
 32 17b19538 2008-07-24 rsc 	{ 0 }
 33 17b19538 2008-07-24 rsc };
 34 17b19538 2008-07-24 rsc 
 35 17b19538 2008-07-24 rsc typedef struct Hdr Hdr;
 36 17b19538 2008-07-24 rsc struct Hdr
 37 17b19538 2008-07-24 rsc {
 38 17b19538 2008-07-24 rsc 	uchar org[3];
 39 17b19538 2008-07-24 rsc 	uchar et[2];
 40 17b19538 2008-07-24 rsc };
 41 17b19538 2008-07-24 rsc 
 42 17b19538 2008-07-24 rsc static Field p_fields[] =
 43 17b19538 2008-07-24 rsc {
 44 17b19538 2008-07-24 rsc 	{ "org",	Fnum,	Oorg,	"org" },
 45 17b19538 2008-07-24 rsc 	{ "et",	Fnum,	Oet,	"et" },
 46 17b19538 2008-07-24 rsc 	{ 0 }
 47 17b19538 2008-07-24 rsc };
 48 17b19538 2008-07-24 rsc 
 49 17b19538 2008-07-24 rsc static void
 50 17b19538 2008-07-24 rsc p_compile(Filter *f)
 51 17b19538 2008-07-24 rsc {
 52 17b19538 2008-07-24 rsc 	Mux *m;
 53 17b19538 2008-07-24 rsc 
 54 17b19538 2008-07-24 rsc 	if(f->op == '='){
 55 17b19538 2008-07-24 rsc 		compile_cmp(snap.name, f, p_fields);
 56 17b19538 2008-07-24 rsc 		return;
 57 17b19538 2008-07-24 rsc 	}
 58 17b19538 2008-07-24 rsc 	for(m = p_mux; m->name != nil; m++){
 59 17b19538 2008-07-24 rsc 		if(strcmp(f->s, m->name) == 0){
 60 17b19538 2008-07-24 rsc 			f->pr = m->pr;
 61 17b19538 2008-07-24 rsc 			f->ulv = m->val;
 62 17b19538 2008-07-24 rsc 			f->subop = Oet;
 63 17b19538 2008-07-24 rsc 			return;
 64 17b19538 2008-07-24 rsc 		}
 65 17b19538 2008-07-24 rsc 	}
 66 17b19538 2008-07-24 rsc 	sysfatal("unknown snap field or protocol: %s", f->s);
 67 17b19538 2008-07-24 rsc }
 68 17b19538 2008-07-24 rsc 
 69 17b19538 2008-07-24 rsc static int
 70 17b19538 2008-07-24 rsc p_filter(Filter *f, Msg *m)
 71 17b19538 2008-07-24 rsc {
 72 17b19538 2008-07-24 rsc 	Hdr *h;
 73 17b19538 2008-07-24 rsc 
 74 17b19538 2008-07-24 rsc 	if(m->pe - m->ps < sizeof(Hdr))
 75 17b19538 2008-07-24 rsc 		return 0;
 76 17b19538 2008-07-24 rsc 	h = (Hdr*)m->ps;
 77 17b19538 2008-07-24 rsc 	m->ps += 5;
 78 17b19538 2008-07-24 rsc 	switch(f->subop){
 79 17b19538 2008-07-24 rsc 	case Oorg:
 80 17b19538 2008-07-24 rsc 		return f->ulv == Net3(h->org);
 81 17b19538 2008-07-24 rsc 	case Oet:
 82 17b19538 2008-07-24 rsc 		return f->ulv == NetS(h->et);
 83 17b19538 2008-07-24 rsc 	}
 84 17b19538 2008-07-24 rsc 	return 0;
 85 17b19538 2008-07-24 rsc }
 86 17b19538 2008-07-24 rsc 
 87 17b19538 2008-07-24 rsc static int
 88 17b19538 2008-07-24 rsc p_seprint(Msg *m)
 89 17b19538 2008-07-24 rsc {
 90 17b19538 2008-07-24 rsc 	Hdr *h;
 91 17b19538 2008-07-24 rsc 
 92 17b19538 2008-07-24 rsc 	if(m->pe - m->ps < sizeof(Hdr))
 93 17b19538 2008-07-24 rsc 		return 0;
 94 17b19538 2008-07-24 rsc 	h = (Hdr*)m->ps;
 95 17b19538 2008-07-24 rsc 	m->ps += 5;
 96 17b19538 2008-07-24 rsc 	demux(p_mux, NetS(h->et), NetS(h->et), m, &dump);
 97 17b19538 2008-07-24 rsc 
 98 17b19538 2008-07-24 rsc 	m->p = seprint(m->p, m->e, "org=%06x et=%04x", Net3(h->org), NetS(h->et));
 99 17b19538 2008-07-24 rsc 	return 0;
100 17b19538 2008-07-24 rsc }
101 17b19538 2008-07-24 rsc 
102 17b19538 2008-07-24 rsc Proto snap =
103 17b19538 2008-07-24 rsc {
104 17b19538 2008-07-24 rsc 	"snap",
105 17b19538 2008-07-24 rsc 	p_compile,
106 17b19538 2008-07-24 rsc 	p_filter,
107 17b19538 2008-07-24 rsc 	p_seprint,
108 17b19538 2008-07-24 rsc 	p_mux,
109 17b19538 2008-07-24 rsc 	nil,
110 17b19538 2008-07-24 rsc 	nil,
111 17b19538 2008-07-24 rsc 	defaultframer
112 17b19538 2008-07-24 rsc };