Subversion Repositories planix.SVN

#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, },
        {"eapol",       0x888e, },
        {"aoe",         0x88a2, } ,
        {"cec",         0xbcbc, } ,
        {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) == 0;
        case Od:
                return memcmp(h->d, f->a, 6) == 0;
        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)
{
        int len;
        uint t;
        Hdr *h;

        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,
        "%#.4lux",
        p_fields,
        defaultframer
};