Exemple #1
0
int
ip_hdr_ttl_and_tos(struct iphdr *iph, int *ttl, int *tos)
{
    struct ip6_hdr *ip6h;

    switch (iph->version) {
    case 4:
        *tos = iph->tos;
        *ttl = iph->ttl;
        return(GOOD);
    case 6:
        ip6h = (struct ip6_hdr *) iph;
        *ttl = ip6h->ip6_hops;
        *tos = IPV6_GET_TC(*ip6h);
        return(GOOD);
    default:
        return(BAD);
    }
}
Exemple #2
0
void add_ip_header (
        char            *position,
        char            *original_packet_position,
        int             ip_payload_length,
        lisp_addr_t     *src_addr,
        lisp_addr_t     *dst_addr)
{


    struct iphdr    *iph        = NULL;
    struct iphdr    *inner_iph  = NULL;
    struct ip6_hdr  *ip6h       = NULL;
    struct ip6_hdr  *inner_ip6h = NULL;

    uint8_t tos = 0;
    uint8_t ttl = 0;


    inner_iph = (struct iphdr *) original_packet_position;

    /* We SHOULD copy ttl and tos fields from the inner packet to the encapsulated one */

    if (inner_iph->version == 4 ) {
        tos = inner_iph->tos;
        ttl = inner_iph->ttl;

    } else {
        inner_ip6h = (struct ip6_hdr *) original_packet_position;
        ttl = inner_ip6h->ip6_hops; /* ttl = Hops limit in IPv6 */

        //tos = (inner_ip6h->ip6_flow & 0x0ff00000) >> 20;  /* 4 bits version, 8 bits Traffic Class, 20 bits flow-ID */
        tos = IPV6_GET_TC(*inner_ip6h); /* tos = Traffic class field in IPv6 */
    }

    /*
     * Construct and add the outer ip header
     */

    switch (dst_addr->afi){
    case AF_INET:

        iph = (struct iphdr *) position;

        iph->version  = 4;
        //iph->ihl      = sizeof ( struct iphdr ) >>2;
        iph->ihl      = 5; /* Minimal IPv4 header */ /*XXX Beware, hardcoded. Supposing no IP options */
        iph->tos      = tos;
        iph->tot_len  = htons(ip_payload_length);
        iph->frag_off = htons(IP_DF);   /* Do not fragment flag. See 5.4.1 in LISP RFC (6830) */
        iph->ttl      = ttl;
        iph->protocol = IPPROTO_UDP;
        iph->check    = 0; //Computed by the NIC (checksum offloading)
        iph->daddr    = dst_addr->address.ip.s_addr;
        iph->saddr    = src_addr->address.ip.s_addr;
        break;

    case AF_INET6:

        ip6h = ( struct ip6_hdr *) position;
        IPV6_SET_VERSION(ip6h, 6);
        IPV6_SET_TC(ip6h,tos);
        IPV6_SET_FLOW_LABEL(ip6h,0);
        ip6h->ip6_plen = htons(ip_payload_length);
        ip6h->ip6_nxt = IPPROTO_UDP;
        ip6h->ip6_hops = ttl;
        memcopy_lisp_addr(&(ip6h->ip6_dst),dst_addr);
        memcopy_lisp_addr(&(ip6h->ip6_src),src_addr);

        break;
    default:
        break;
    }


}