C++ (Cpp) GET_IP_HDR_LEN示例

示例#1

文件： encode.c 项目： DHODoS/snort

static ENC_STATUS IP4_Update (Packet* p, Layer* lyr, uint32_t* len)
{
    IPHdr* h = (IPHdr*)(lyr->start);
    int i = lyr - p->layers;

    *len += GET_IP_HDR_LEN(h);

    if ( i + 1 == p->next_layer )
    {
        *len += p->dsize;
    }
    h->ip_len = htons((uint16_t)*len);

    if ( !PacketWasCooked(p) || (p->packet_flags & PKT_REBUILT_FRAG) )
    {
        h->ip_csum = 0;
        h->ip_csum = in_chksum_ip((const uint16_t *)h, GET_IP_HDR_LEN(h));
    }

    return ENC_OK;
}

示例#2

static ENC_STATUS IP4_Encode (EncState* enc, Buffer* in, Buffer* out)
{
    int len;
    uint32_t start = out->end;

    IPHdr* hi = (IPHdr*)enc->p->layers[enc->layer-1].start;
    IPHdr* ho = (IPHdr*)(out->base + out->end);
    PROTO_ID next = NextEncoder(enc);
    UPDATE_BOUND(out, sizeof(*ho));

    len = GET_IP_HDR_LEN(hi) - sizeof(*hi);

    ho->ip_verhl = 0x45;
    ho->ip_off = 0;

    ho->ip_id = IpId_Next();
    ho->ip_tos = hi->ip_tos;
    ho->ip_proto = hi->ip_proto;

    if ( FORWARD(enc) )
    {
        uint8_t ttl = AdjTTL(hi->ip_ttl);

        ho->ip_src.s_addr = hi->ip_src.s_addr;
        ho->ip_dst.s_addr = hi->ip_dst.s_addr;

        if ( enc->p->ssnptr )
            ttl = GetTTL(enc);

#ifdef NORMALIZER
        if ( ttl < ScMinTTL() && ScNewTTL() )
            ttl = ScNewTTL();
#endif
        ho->ip_ttl = ttl;
    }
    else
    {
        uint8_t ttl = MAX_TTL;

        ho->ip_src.s_addr = hi->ip_dst.s_addr;
        ho->ip_dst.s_addr = hi->ip_src.s_addr;

        if ( enc->p->ssnptr )
            ttl = GetTTL(enc);

#ifdef NORMALIZER
        if ( ttl < ScMinTTL() && ScNewTTL() )
            ttl = ScNewTTL();
#endif
        ho->ip_ttl = ttl;
    }

    enc->ip_hdr = (uint8_t*)hi;
    enc->ip_len = IP_HLEN(hi) << 2;

    if ( next < PROTO_MAX )
    {
        int err = encoders[next].fencode(enc, in, out);
        if ( err ) return err;
    }  
    if ( enc->proto )
    {
        ho->ip_proto = enc->proto;
        enc->proto = 0;
    }
    len = out->end - start;
    ho->ip_len = htons((u_int16_t)len);
    ip_checksum(ho, len);

    return ENC_OK;
}