1 files changed, 128 insertions, 0 deletions
diff --git a/src/cmd/ip/snoopy/arp.c b/src/cmd/ip/snoopy/arp.c
new file mode 100755
index 00000000..3433ebc6
--- /dev/null
+++ b/src/cmd/ip/snoopy/arp.c
@@ -0,0 +1,128 @@
+#include <u.h>
+#include <libc.h>
+#include <ip.h>
+#include "dat.h"
+#include "protos.h"
+
+typedef struct Hdr	Hdr;
+struct Hdr
+{
+	uchar	hrd[2];
+	uchar	pro[2];
+	uchar	hln;
+	uchar	pln;
+	uchar	op[2];
+	uchar	sha[6];
+	uchar	spa[4];
+	uchar	tha[6];
+	uchar	tpa[4];
+};
+
+enum
+{
+	ARPLEN=	28,
+};
+
+enum
+{
+	Ospa,
+	Otpa,
+	Ostpa,
+	Osha,
+	Otha,
+	Ostha,
+	Opa,
+};
+
+static Field p_fields[] = 
+{
+	{"spa",		Fv4ip,	Ospa,	"protocol source",	} ,
+	{"tpa",		Fv4ip,	Otpa,	"protocol target",	} ,
+	{"a",		Fv4ip,	Ostpa,	"protocol source/target",	} ,
+	{"sha",		Fba,	Osha,	"hardware source",	} ,
+	{"tha",		Fba,	Otha,	"hardware target",	} ,
+	{"ah",	 	Fba,	Ostha,	"hardware source/target",	} ,
+	{0}
+};
+
+static void
+p_compile(Filter *f)
+{
+	if(f->op == '='){
+		compile_cmp(arp.name, f, p_fields);
+		return;
+	}
+	sysfatal("unknown arp field: %s", f->s);
+}
+
+static int
+p_filter(Filter *f, Msg *m)
+{
+	Hdr *h;
+
+	if(m->pe - m->ps < ARPLEN)
+		return 0;
+
+	h = (Hdr*)m->ps;
+	m->ps += ARPLEN;
+
+	switch(f->subop){
+	case Ospa:
+		return h->pln == 4 && NetL(h->spa) == f->ulv;
+	case Otpa:
+		return h->pln == 4 && NetL(h->tpa) == f->ulv;
+	case Ostpa:
+		return h->pln == 4 && (NetL(h->tpa) == f->ulv ||
+			NetL(h->spa) == f->ulv);
+	case Osha:
+		return memcmp(h->sha, f->a, h->hln) == 0;
+	case Otha:
+		return memcmp(h->tha, f->a, h->hln) == 0;
+	case Ostha:
+		return memcmp(h->sha, f->a, h->hln)==0
+			||memcmp(h->tha, f->a, h->hln)==0;
+	}
+	return 0;
+}
+
+static int
+p_seprint(Msg *m)
+{
+	Hdr *h;
+
+	if(m->pe - m->ps < ARPLEN)
+		return -1;
+
+	h = (Hdr*)m->ps;
+	m->ps += ARPLEN;
+
+	/* no next protocol */
+	m->pr = nil;
+
+	m->p = seprint(m->p, m->e, "op=%1d len=%1d/%1d spa=%V sha=%E tpa=%V tha=%E",
+			NetS(h->op), h->pln, h->hln,
+			h->spa, h->sha, h->tpa, h->tha);
+	return 0;
+}
+
+Proto arp =
+{
+	"arp",
+	p_compile,
+	p_filter,
+	p_seprint,
+	nil,
+	p_fields,
+	defaultframer,
+};
+
+Proto rarp =
+{
+	"rarp",
+	p_compile,
+	p_filter,
+	p_seprint,
+	nil,
+	p_fields,
+	defaultframer,
+};