(usagi-users 04042) Add type two routing header through XFRM in NEPL

[Matthew Jakeman <m.jakeman@xxxxxxxxxxxxxxx>]

Hi all,

I have been trying to add a type two routing header to all traffic forwarded 
through a MR in xfrm.c in the NEPL code.

As XFRM seems to not be well documented, I have been piecing together bits and 
pieces from xfrm.c to try and get this working.

The code I have so far is as follows (called in process_first_home_bu() in 
mn.c):

void xfrm_rh2_add(struct bulentry *bul)
{
    struct xfrm_selector sel;
    struct xfrm_user_tmpl tmpl;
    int prio = 2;
    int update = 0;
    struct in6_addr src ;

    inet_pton(AF_INET6, "2001:db40::", &src) ;
    set_selector(&in6addr_any, &src, 0, 0, 0, 0, &sel) ;
    sel.prefixlen_s = 64;
    create_rh_tmpl(&tmpl) ;
    if(xfrm_mip_policy_add(&sel, 0, XFRM_POLICY_FWD, XFRM_POLICY_ALLOW, 
MIP6_PRIO_RO_DATA_ANY, &tmpl, 1))
        return -1;
    if(xfrm_state_add(&sel, IPPROTO_ROUTING, &bul->coa, 0, 0))
        printf("Failed to add XFRM State for RRH\n") ;
}

The policy and state are both being inserted, and if I change 
XFRM_POLICY_ALLOW to XFRM_POLICY_BLOCK in xfrm_mip_policy_add() then it 
effectively drops all packets from any 2001:db40::/64 address. From what I 
have gathered I expected this function to add a type 2 routing header to any 
packets from that prefix but it does not.

Any help on this would be hugely appreciated.

Cheers
Matthew Jakeman