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   code;
        uchar   id;
        uchar   len[2]; /* length including this header */

        uchar   tp;     /* optional, only for Request/Response */
};

enum
{
        EAPHDR= 4,      /* sizeof(code)+sizeof(id)+sizeof(len) */
        TPHDR= 1,       /* sizeof(tp) */

        /* eap types */
        Request = 1,
        Response,
        Success,
        Fail,

        /* eap request/response sub-types */
        Identity = 1,           /* Identity */
        Notify,         /* Notification */
        Nak,                    /* Nak (Response only) */
        Md5,            /* MD5-challenge */
        Otp,                    /* one time password */
        Gtc,                    /* generic token card */
        Ttls = 21,              /* tunneled TLS */
        Xpnd = 254,     /* expanded types */
        Xprm,           /* experimental use */
};

enum
{
        Ot,
};

static Mux p_mux[] =
{
        { "eap_identity", Identity, },
        { "eap_notify", Notify, },
        { "eap_nak", Nak, },
        { "eap_md5", Md5, },
        { "eap_otp", Otp, },
        { "eap_gtc", Gtc, },
        { "ttls", Ttls, },
        { "eap_xpnd", Xpnd, },
        { "eap_xprm", Xprm, }, 
        { 0 }
};

static char *eapsubtype[256] =
{
[Identity]      "Identity",
[Notify]        "Notify",
[Nak]           "Nak",
[Md5]   "Md5",
[Otp]           "Otp",
[Gtc]           "Gtc",
[Ttls]          "Ttls",
[Xpnd]  "Xpnd",
[Xprm]  "Xprm",
};


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

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

        if(f->subop != Ot)
                return 0;

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

        h = (Hdr*)m->ps;

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

        if(h->code != Request && h->code != Response)
                return 0;
        m->ps += TPHDR;

        if(h->tp == f->ulv)
                return 1;

        return 0;
}

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

        switch(i){
        case Request:
                return "Request";
        case Response:
                return "Response";
        case Success:
                return "Success";
        case Fail:
                return "Fail";
        default:
                sprint(x, "%1d", i);
                return x;
        }
}

static char*
subop(uchar val)
{
        static char x[20], *p;

        p = eapsubtype[val];
        if(p != nil)
                return p;
        else {
                sprint(x, "%1d", val);
                return x;
        }
}

static int
p_seprint(Msg *m)
{
        Hdr *h;
        int len;
        char *p, *e;

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

        p = m->p;
        e = m->e;
        h = (Hdr*)m->ps;

        /* resize packet (should already be done by eapol) */
        /* len includes header */
        len = NetS(h->len);
        if(m->ps+len < m->pe)
                m->pe = m->ps+len;
        else if(m->ps+len > m->pe)
                return -1;
        m->ps += EAPHDR;

        p = seprint(p, e, "id=%1d code=%s", h->id, op(h->code));
        switch(h->code) {
        case Request:
        case Response:
                m->ps += TPHDR;
                p = seprint(p, e, " type=%s", subop(h->tp));
                /* special case needed to print eap_notify notification as unicode */
                demux(p_mux, h->tp, h->tp, m, &dump);
                break;
        default:
                demux(p_mux, 0, 0, m, &dump);
                break;
        }
        m->p = seprint(p, e, " len=%1d", len);
        return 0;
}

static int
p_seprintidentity(Msg *m)
{
        char *ps, *pe, *z;
        int len;

        m->pr = nil;
        ps = (char*)m->ps;
        pe = (char*)m->pe;

        /* we would like to do this depending on the 'context':
         *  - one for eap_identity request and
         *  - one for eap_identity response
         * but we've lost the context, or haven't we?
         * so we treat them the same, so we might erroneously
         * print a response as if it was a request. too bad. - axel
         */
        for (z=ps; *z != '\0' && z+1 < pe; z++)
                ;
        if (*z == '\0' && z+1 < pe) {
                m->p = seprint(m->p, m->e, "prompt=(%s)", ps);
                len = pe - (z+1);
                m->p = seprint(m->p, m->e, " options=(%.*s)", len, z+1);
        } else {
                len = pe - ps;
                m->p = seprint(m->p, m->e, "%.*s", len, ps);
        }
        return 0;
}

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

Proto eap_identity =
{
        "eap_identity",
        p_compile,
        p_filter,
        p_seprintidentity,
        nil,
        nil,
        nil,
        defaultframer,
};