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   vi;             /* version */
        uchar   type;
        uchar   len[2]; /* length of data following this header */
};

enum
{
        EAPOLHDR=       4,              /* sizeof(Hdr) */

        /* eapol types */
        Eap = 0,
        Start,
        Logoff,
        Key,
        AsfAlert,
};

enum
{
        Ot,     /* type */
};

static Mux p_mux[] =
{
        { "eap", Eap, },
        { "eapol_start", Start, },
        { "eapol_logoff", Logoff, },
        { "eapol_key", Key, },
        { "asf_alert", AsfAlert, },
        { 0 }
};

static void
p_compile(Filter *f)
{
        Mux *m;

        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 eapol field or type: %s", f->s);
}

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

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

        h = (Hdr*)m->ps;

        /* len does not include header */
        m->ps += EAPOLHDR;

        switch(f->subop){
        case Ot:
                return h->type == f->ulv;
        }
        return 0;
}

static char*
op(int i)
{
        static char x[20];

        switch(i){
        case Eap:
                return "Eap";
        case Start:
                return "Start";
        case Logoff:
                return "Logoff";
        case Key:
                return "Key";
        case AsfAlert:
                return "AsfAlert";
        default:
                sprint(x, "%1d", i);
                return x;
        }
}

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

        if(m->pe - m->ps < EAPOLHDR)
                return -1;

        h = (Hdr*)m->ps;

        /* len does not include header */
        m->ps += EAPOLHDR;

        /* truncate the message if there's extra */
        len = NetS(h->len);
        if(m->ps + len < m->pe)
                m->pe = m->ps + len;
        else if(m->ps+len > m->pe)
                return -1;

        /* next protocol  depending on type*/
        demux(p_mux, h->type, h->type, m, &dump);

        m->p = seprint(m->p, m->e, "type=%s version=%1d datalen=%1d",
                        op(h->type), h->vi, len);
        return 0;
}

Proto eapol =
{
        "eapol",
        p_compile,
        p_filter,
        p_seprint,
        p_mux,
        "%lud",
        nil,
        defaultframer,
};