new goodies

src/cmd/ip/snoopy/ether.c

@@ -0,0 +1,121 @@
+#include <u.h>
+#include <libc.h>
+#include <ip.h>
+#include "dat.h"
+#include "protos.h"
+
+typedef struct Hdr	Hdr;
+struct Hdr {
+	uchar d[6];
+	uchar s[6];
+	uchar type[2];
+	char data[1500];
+};
+#define	ETHERMINTU	60	/* minimum transmit size */
+#define	ETHERMAXTU	1514	/* maximum transmit size */
+#define ETHERHDRSIZE	14	/* size of an ethernet header */
+
+static Mux p_mux[] =
+{
+	{"ip",		0x0800,	} ,
+	{"arp",		0x0806,	} ,
+	{"rarp",	0x0806,	} ,
+	{"ip6", 	0x86dd, } ,
+	{"pppoe_disc",	0x8863, },
+	{"pppoe_sess",	0x8864, },
+	{0}
+};
+
+enum
+{
+	Os,	// source
+	Od,	// destination
+	Oa,	// source or destination
+	Ot,	// type
+};
+
+static Field p_fields[] = 
+{
+	{"s",	Fether,	Os,	"source address",	} ,
+	{"d",	Fether,	Od,	"destination address",	} ,
+	{"a",	Fether,	Oa,	"source|destination address" } ,
+	{"sd",	Fether,	Oa,	"source|destination address" } ,
+	{"t",	Fnum,	Ot,	"type" } ,
+	{0}
+};
+
+static void
+p_compile(Filter *f)
+{
+	Mux *m;
+
+	if(f->op == '='){
+		compile_cmp(ether.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 = Ot;
+			return;
+		}
+	sysfatal("unknown ethernet field or protocol: %s", f->s);
+}
+
+static int
+p_filter(Filter *f, Msg *m)
+{
+	Hdr *h;
+
+	if(m->pe - m->ps < ETHERHDRSIZE)
+		return 0;
+
+	h = (Hdr*)m->ps;
+	m->ps += ETHERHDRSIZE;
+
+	switch(f->subop){
+	case Os:
+		return !memcmp(h->s, f->a, 6);
+	case Od:
+		return !memcmp(h->d, f->a, 6);
+	case Oa:
+		return memcmp(h->s, f->a, 6) == 0 || memcmp(h->d, f->a, 6) == 0;
+	case Ot:
+		return NetS(h->type) == f->ulv;
+	}
+	return 0;
+}
+
+static int
+p_seprint(Msg *m)
+{
+	Hdr *h;
+	uint t;
+	int len;
+
+	len = m->pe - m->ps;
+	if(len < ETHERHDRSIZE)
+		return -1;
+
+	h = (Hdr*)m->ps;
+	m->ps += ETHERHDRSIZE;
+
+	t = NetS(h->type);
+	demux(p_mux, t, t, m, &dump);
+
+	m->p = seprint(m->p, m->e, "s=%E d=%E pr=%4.4ux ln=%d", h->s, h->d,
+		t, len);
+	return 0;
+}
+
+Proto ether =
+{
+	"ether",
+	p_compile,
+	p_filter,
+	p_seprint,
+	p_mux,
+	p_fields,
+	defaultframer
+};