1 17b19538 2008-07-24 rsc /* 
  2 17b19538 2008-07-24 rsc  * LLC.  Only enough to dispatch to SNAP and IP.
  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 	UFmt = 3,
 14 17b19538 2008-07-24 rsc 	Gsap = 1,
 15 17b19538 2008-07-24 rsc 	IG = 1,
 16 17b19538 2008-07-24 rsc 	SFmt = 1,
 17 17b19538 2008-07-24 rsc 	UPoll = 0x10,
 18 17b19538 2008-07-24 rsc 	IsPoll = 0x100,
 19 17b19538 2008-07-24 rsc 	XidFi = 0x81,
 20 17b19538 2008-07-24 rsc 	
 21 17b19538 2008-07-24 rsc 	SapNull = 0,
 22 17b19538 2008-07-24 rsc 	SapGlobal = 0xff,
 23 17b19538 2008-07-24 rsc 	Sap8021BI = 0x02,
 24 17b19538 2008-07-24 rsc 	Sap8021BG = 0x03,
 25 17b19538 2008-07-24 rsc 	SapSNA = 0x04,
 26 17b19538 2008-07-24 rsc 	SapIP = 0x06,
 27 17b19538 2008-07-24 rsc 	SapProwayNM = 0x0e,
 28 17b19538 2008-07-24 rsc 	Sap8021D = 0x42,
 29 17b19538 2008-07-24 rsc 	SapRS511 = 0x4e,
 30 17b19538 2008-07-24 rsc 	SapISO8208 = 0x7e,
 31 17b19538 2008-07-24 rsc 	SapProway = 0x8e,
 32 17b19538 2008-07-24 rsc 	SapSnap = 0xaa,
 33 17b19538 2008-07-24 rsc 	SapIpx = 0xe0,
 34 17b19538 2008-07-24 rsc 	SapNetbeui = 0xf0,
 35 17b19538 2008-07-24 rsc 	SapIsons = 0xfe,
 36 17b19538 2008-07-24 rsc };
 37 17b19538 2008-07-24 rsc 
 38 17b19538 2008-07-24 rsc static Mux p_mux[] =
 39 17b19538 2008-07-24 rsc {
 40 17b19538 2008-07-24 rsc // Linux gives llc -> snap not llc -> ip.
 41 17b19538 2008-07-24 rsc // If we don't tell snoopy about llc -> ip, then the default patterns
 42 17b19538 2008-07-24 rsc // like snoopy -h radiotap -f dns work better.
 43 17b19538 2008-07-24 rsc //	{ "ip", SapIP },	
 44 17b19538 2008-07-24 rsc 	{ "snap", SapSnap },
 45 17b19538 2008-07-24 rsc 	{ 0 }
 46 17b19538 2008-07-24 rsc };
 47 17b19538 2008-07-24 rsc 
 48 17b19538 2008-07-24 rsc typedef struct Hdr Hdr;
 49 17b19538 2008-07-24 rsc struct Hdr
 50 17b19538 2008-07-24 rsc {
 51 17b19538 2008-07-24 rsc 	uchar dsap;
 52 17b19538 2008-07-24 rsc 	uchar ssap;
 53 17b19538 2008-07-24 rsc 	uchar dsapf;
 54 17b19538 2008-07-24 rsc 	uchar ssapf;
 55 17b19538 2008-07-24 rsc 	ushort ctl;
 56 17b19538 2008-07-24 rsc 	uchar isu;
 57 17b19538 2008-07-24 rsc 	int hdrlen;
 58 17b19538 2008-07-24 rsc };
 59 17b19538 2008-07-24 rsc 
 60 17b19538 2008-07-24 rsc static int
 61 17b19538 2008-07-24 rsc unpackhdr(uchar *p, uchar *ep, Hdr *h)
 62 17b19538 2008-07-24 rsc {
 63 17b19538 2008-07-24 rsc 	if(p+3 > ep)
 64 17b19538 2008-07-24 rsc 		return -1;
 65 17b19538 2008-07-24 rsc 	h->dsapf = p[0];
 66 17b19538 2008-07-24 rsc 	h->dsap = h->dsapf & ~IG;
 67 17b19538 2008-07-24 rsc 	h->ssapf = p[1];
 68 17b19538 2008-07-24 rsc 	h->ssap = h->ssapf & ~Gsap;
 69 17b19538 2008-07-24 rsc 	h->ctl = p[2];
 70 17b19538 2008-07-24 rsc 	h->hdrlen = 3;
 71 17b19538 2008-07-24 rsc 	if((h->ctl&UFmt) == UFmt)
 72 17b19538 2008-07-24 rsc 		h->isu = 1;
 73 17b19538 2008-07-24 rsc 	else{
 74 17b19538 2008-07-24 rsc 		if(p+4 > ep)
 75 17b19538 2008-07-24 rsc 			return -1;
 76 17b19538 2008-07-24 rsc 		h->hdrlen = 4;
 77 17b19538 2008-07-24 rsc 		h->ctl = LittleS(p+2);
 78 17b19538 2008-07-24 rsc 	}
 79 17b19538 2008-07-24 rsc 	return 0;
 80 17b19538 2008-07-24 rsc }
 81 17b19538 2008-07-24 rsc 
 82 17b19538 2008-07-24 rsc enum
 83 17b19538 2008-07-24 rsc {
 84 17b19538 2008-07-24 rsc 	Ossap,
 85 17b19538 2008-07-24 rsc 	Odsap,
 86 17b19538 2008-07-24 rsc 	Ot,
 87 17b19538 2008-07-24 rsc };
 88 17b19538 2008-07-24 rsc 
 89 17b19538 2008-07-24 rsc static Field p_fields[] =
 90 17b19538 2008-07-24 rsc {
 91 17b19538 2008-07-24 rsc 	{ "ssap",	Fnum,	Ossap,	"ssap" },
 92 17b19538 2008-07-24 rsc 	{ "dsap",	Fnum,	Odsap,	"dsap" },
 93 17b19538 2008-07-24 rsc 	{ 0 }
 94 17b19538 2008-07-24 rsc };
 95 17b19538 2008-07-24 rsc 
 96 17b19538 2008-07-24 rsc static void
 97 17b19538 2008-07-24 rsc p_compile(Filter *f)
 98 17b19538 2008-07-24 rsc {
 99 17b19538 2008-07-24 rsc 	Mux *m;
100 17b19538 2008-07-24 rsc 
101 17b19538 2008-07-24 rsc 	if(f->op == '='){
102 17b19538 2008-07-24 rsc 		compile_cmp(llc.name, f, p_fields);
103 17b19538 2008-07-24 rsc 		return;
104 17b19538 2008-07-24 rsc 	}
105 17b19538 2008-07-24 rsc 	for(m = p_mux; m->name != nil; m++){
106 17b19538 2008-07-24 rsc 		if(strcmp(f->s, m->name) == 0){
107 17b19538 2008-07-24 rsc 			f->pr = m->pr;
108 17b19538 2008-07-24 rsc 			f->ulv = m->val;
109 17b19538 2008-07-24 rsc 			f->subop = Ot;
110 17b19538 2008-07-24 rsc 			return;
111 17b19538 2008-07-24 rsc 		}
112 17b19538 2008-07-24 rsc 	}
113 17b19538 2008-07-24 rsc 	sysfatal("unknown llc field or protocol: %s", f->s);
114 17b19538 2008-07-24 rsc }
115 17b19538 2008-07-24 rsc 
116 17b19538 2008-07-24 rsc static int
117 17b19538 2008-07-24 rsc p_filter(Filter *f, Msg *m)
118 17b19538 2008-07-24 rsc {
119 17b19538 2008-07-24 rsc 	Hdr h;
120 17b19538 2008-07-24 rsc 
121 17b19538 2008-07-24 rsc 	memset(&h, 0, sizeof h);
122 17b19538 2008-07-24 rsc 	if(unpackhdr(m->ps, m->pe, &h) < 0)
123 17b19538 2008-07-24 rsc 		return 0;
124 17b19538 2008-07-24 rsc 	m->ps += h.hdrlen;
125 17b19538 2008-07-24 rsc 
126 17b19538 2008-07-24 rsc 	switch(f->subop){
127 17b19538 2008-07-24 rsc 	case Ossap:
128 17b19538 2008-07-24 rsc 		return f->ulv == h.ssap;
129 17b19538 2008-07-24 rsc 	case Odsap:
130 17b19538 2008-07-24 rsc 		return f->ulv == h.dsap;
131 17b19538 2008-07-24 rsc 	case Ot:
132 17b19538 2008-07-24 rsc 		return f->ulv == h.ssap && f->ulv == h.dsap;
133 17b19538 2008-07-24 rsc 	}
134 17b19538 2008-07-24 rsc 	return 0;
135 17b19538 2008-07-24 rsc }
136 17b19538 2008-07-24 rsc 
137 17b19538 2008-07-24 rsc static int
138 17b19538 2008-07-24 rsc p_seprint(Msg *m)
139 17b19538 2008-07-24 rsc {
140 17b19538 2008-07-24 rsc 	Hdr h;
141 17b19538 2008-07-24 rsc 	
142 17b19538 2008-07-24 rsc 	memset(&h, 0, sizeof h);
143 17b19538 2008-07-24 rsc 	if(unpackhdr(m->ps, m->pe, &h) < 0)
144 17b19538 2008-07-24 rsc 		return -1;
145 17b19538 2008-07-24 rsc 
146 17b19538 2008-07-24 rsc 	m->pr = &dump;
147 17b19538 2008-07-24 rsc 	m->p = seprint(m->p, m->e, "ssap=%02x dsap=%02x ctl=%04x", h.ssap, h.dsap, h.ctl);
148 17b19538 2008-07-24 rsc 	m->ps += h.hdrlen;
149 17b19538 2008-07-24 rsc 	m->pr = &dump;
150 17b19538 2008-07-24 rsc 	if(h.ssap == h.dsap){
151 17b19538 2008-07-24 rsc 		switch(h.ssap){
152 17b19538 2008-07-24 rsc 		case SapIP:
153 17b19538 2008-07-24 rsc 			m->pr = &ip;
154 17b19538 2008-07-24 rsc 			break;
155 17b19538 2008-07-24 rsc 		case SapSnap:
156 17b19538 2008-07-24 rsc 			m->pr = &snap;
157 17b19538 2008-07-24 rsc 			break;
158 17b19538 2008-07-24 rsc 		}
159 17b19538 2008-07-24 rsc 	}	
160 17b19538 2008-07-24 rsc 	return 0;
161 17b19538 2008-07-24 rsc }
162 17b19538 2008-07-24 rsc 
163 17b19538 2008-07-24 rsc Proto llc =
164 17b19538 2008-07-24 rsc {
165 17b19538 2008-07-24 rsc 	"llc",
166 17b19538 2008-07-24 rsc 	p_compile,
167 17b19538 2008-07-24 rsc 	p_filter,
168 17b19538 2008-07-24 rsc 	p_seprint,
169 17b19538 2008-07-24 rsc 	p_mux,
170 17b19538 2008-07-24 rsc 	nil,
171 17b19538 2008-07-24 rsc 	nil,
172 17b19538 2008-07-24 rsc 	defaultframer
173 17b19538 2008-07-24 rsc };