Subversion Repositories planix.SVN

#include <u.h>
#include <libc.h>
#include <ip.h>
#include <thread.h>
#include "netbios.h"

int
nbdgramconvM2S(NbDgram *s, uchar *ap, uchar *ep)
{
        uchar *p = ap;
        int n;
        ushort length;

        if (ap + 6 + IPv4addrlen > ep)
                return 0;
        s->type = *p++;
        s->flags = *p++;
        s->id = nhgets(p); p+= 2;
        v4tov6(s->srcip, p); p+= IPv4addrlen;
        s->srcport = nhgets(p); p += 2;
        switch (s->type) {
        case NbDgramDirectUnique:
        case NbDgramDirectGroup:
        case NbDgramBroadcast:
                if (p + 4 > ep)
                        return 0;
                length = nhgets(p); p += 2;
                s->datagram.offset = nhgets(p); p += 2;
                if (p + length > ep)
                        return 0;
                ep = p + length;
                n = nbnamedecode(p, p, ep, s->datagram.srcname);
                if (n == 0)
                        return 0;
                p += n;
                n = nbnamedecode(p, p, ep, s->datagram.dstname);
                if (n == 0)
                        return 0;
                p += n;
                s->datagram.data = p;
                s->datagram.length = ep - p;
                p = ep;
                break;
        case NbDgramError:
                if (p + 1 > ep)
                        return 0;
                s->error.code = *p++;
                break;
        case NbDgramQueryRequest:
        case NbDgramPositiveQueryResponse:
        case NbDgramNegativeQueryResponse:
                n = nbnamedecode(p, p, ep, s->query.dstname);
                if (n == 0)
                        return 0;
                p += n;
                break;
        default:
                return 0;
        }
        return p - ap;
}

int
nbdgramconvS2M(uchar *ap, uchar *ep, NbDgram *s)
{
        uchar *p = ap;
        uchar *fixup;
        int n;

        if (p + 6 + IPv4addrlen > ep)
                return 0;
        *p++ = s->type;
        *p++ = s->flags;
        hnputs(p, s->id); p+= 2;
        v6tov4(p, s->srcip); p += IPv4addrlen;
        hnputs(p, s->srcport); p+= 2;
        switch (s->type) {
        case NbDgramDirectUnique:
        case NbDgramDirectGroup:
        case NbDgramBroadcast:
                if (p + 4 > ep)
                        return 0;
                fixup = p;
                hnputs(p, s->datagram.length); p += 2;
                hnputs(p, s->datagram.offset); p += 2;
                n = nbnameencode(p, ep, s->datagram.srcname);
                if (n == 0)
                        return 0;
                p += n;
                n = nbnameencode(p, ep, s->datagram.dstname);
                if (n == 0)
                        return 0;
                p += n;
                if (p + s->datagram.length > ep)
                        return 0;
                memcpy(p, s->datagram.data, s->datagram.length); p += s->datagram.length;
                hnputs(fixup, p - fixup - 4);
                break;
        case NbDgramError:
                if (p + 1 > ep)
                        return 0;
                *p++ = s->error.code;
                break;
        case NbDgramQueryRequest:
        case NbDgramPositiveQueryResponse:
        case NbDgramNegativeQueryResponse:
                n = nbnameencode(p, ep, s->datagram.dstname);
                if (n == 0)
                        return 0;
                p += n;
                break;
        default:
                return 0;
        }
        return p - ap;
}