code: plan9front

ref: 5622b0bbd878dbc34045cc6fd37cffa64461eabe
dir: /sys/src/cmd/ip/snoopy/aoecmd.c/

#include <u.h>
#include <libc.h>
#include <ip.h>
#include "dat.h"
#include "protos.h"

typedef struct{
	uchar	bc[2];
	uchar	fw[2];
	uchar	sc;
	uchar	ccmd;
	uchar	len[2];
}Hdr;

enum{
	Hsize	= 8,
};

enum{
	Ocmd,
};

static Field p_fields[] =
{
	{"cmd",		Fnum,	Ocmd,		"cmd",	},
	{0}
};

static void
p_compile(Filter *f)
{
	if(f->op == '='){
		compile_cmp(aoecmd.name, f, p_fields);
		return;
	}
	sysfatal("unknown aoecmd field: %s", f->s);
}

static int
p_filter(Filter *f, Msg *m)
{
	Hdr *h;

	if(m->pe - m->ps < Hsize)
		return 0;

	h = (Hdr*)m->ps;
	m->ps += Hsize;

	switch(f->subop){
	case Ocmd:
		return (h->ccmd & 0xf) == f->ulv;
	}
	return 0;
}

static int
p_seprint(Msg *m)
{
	Hdr *h;

	if(m->pe - m->ps < Hsize)
		return 0;

	h = (Hdr*)m->ps;
	m->ps += Hsize;

	/* no next protocol */
	m->pr = nil;

	m->p = seprint(m->p, m->e, "bc=%d fw=%.4x sc=%d ver=%d ccmd=%d len=%d cfg=",
		NetS(h->bc), NetS(h->fw), h->sc, h->ccmd >> 4, h->ccmd & 0xf,
		NetS(h->len));
	m->p = seprint(m->p, m->e, "%.*s", NetS(h->len), (char*)m->ps);
	return 0;
}

Proto aoecmd =
{
	"aoecmd",
	p_compile,
	p_filter,
	p_seprint,
	nil,
	nil,
	p_fields,
	defaultframer,
};