[XFRM] STATE: Support non-fragment outbound transformation headers.

For originated outbound IPv6 packets which will fragment, ip6_append_data()
should know length of extension headers before sending them and
the length is carried by dst_entry.
IPv6 IPsec headers fragment then transformation was
designed to place all headers after fragment header.
OTOH Mobile IPv6 extension headers do not fragment then
it is a good idea to make dst_entry have non-fragment length to tell it
to ip6_append_data().

Signed-off-by: Masahide NAKAMURA <nakam@linux-ipv6.org>
Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/include/net/dst.h b/include/net/dst.h
index 36d54fc..a8d825f 100644 (file)
--- a/include/net/dst.h
+++ b/include/net/dst.h
@@ -54,6 +54,7 @@ struct dst_entry
        unsigned long           expires;
 
        unsigned short          header_len;     /* more space at head required */
+       unsigned short          nfheader_len;   /* more non-fragment space at head required */
        unsigned short          trailer_len;    /* space to reserve at tail */
 
        u32                     metrics[RTAX_MAX];

diff --git a/include/net/xfrm.h b/include/net/xfrm.h
index aa3ac99..aa93cc1 100644 (file)
--- a/include/net/xfrm.h
+++ b/include/net/xfrm.h
@@ -260,6 +260,8 @@ struct xfrm_type
        char                    *description;
        struct module           *owner;
        __u8                    proto;
+       __u8                    flags;
+#define XFRM_TYPE_NON_FRAGMENT 1
 
        int                     (*init_state)(struct xfrm_state *x);
        void                    (*destructor)(struct xfrm_state *);

diff --git a/net/ipv4/xfrm4_policy.c b/net/ipv4/xfrm4_policy.c
index a5bed74..e517981 100644 (file)
--- a/net/ipv4/xfrm4_policy.c
+++ b/net/ipv4/xfrm4_policy.c
@@ -135,6 +135,7 @@ __xfrm4_bundle_create(struct xfrm_policy *policy, struct xfrm_state **xfrm, int
                dst_prev->flags        |= DST_HOST;
                dst_prev->lastuse       = jiffies;
                dst_prev->header_len    = header_len;
+               dst_prev->nfheader_len  = 0;
                dst_prev->trailer_len   = trailer_len;
                memcpy(&dst_prev->metrics, &x->route->metrics, sizeof(dst_prev->metrics));
 

diff --git a/net/ipv6/ip6_output.c b/net/ipv6/ip6_output.c
index 2a376b7..258e3e4 100644 (file)
--- a/net/ipv6/ip6_output.c
+++ b/net/ipv6/ip6_output.c
@@ -971,7 +971,7 @@ int ip6_append_data(struct sock *sk, int getfrag(void *from, char *to,
 
        hh_len = LL_RESERVED_SPACE(rt->u.dst.dev);
 
-       fragheaderlen = sizeof(struct ipv6hdr) + (opt ? opt->opt_nflen : 0);
+       fragheaderlen = sizeof(struct ipv6hdr) + rt->u.dst.nfheader_len + (opt ? opt->opt_nflen : 0);
        maxfraglen = ((mtu - fragheaderlen) & ~7) + fragheaderlen - sizeof(struct frag_hdr);
 
        if (mtu <= sizeof(struct ipv6hdr) + IPV6_MAXPLEN) {

diff --git a/net/ipv6/xfrm6_policy.c b/net/ipv6/xfrm6_policy.c
index 9328fc8..a3f68c8 100644 (file)
--- a/net/ipv6/xfrm6_policy.c
+++ b/net/ipv6/xfrm6_policy.c
@@ -75,6 +75,24 @@ __xfrm6_bundle_addr_local(struct xfrm_state *x, struct in6_addr *addr)
                (struct in6_addr*)&x->props.saddr;
 }
 
+static inline void
+__xfrm6_bundle_len_inc(int *len, int *nflen, struct xfrm_state *x)
+{
+       if (x->type->flags & XFRM_TYPE_NON_FRAGMENT)
+               *nflen += x->props.header_len;
+       else
+               *len += x->props.header_len;
+}
+
+static inline void
+__xfrm6_bundle_len_dec(int *len, int *nflen, struct xfrm_state *x)
+{
+       if (x->type->flags & XFRM_TYPE_NON_FRAGMENT)
+               *nflen -= x->props.header_len;
+       else
+               *len -= x->props.header_len;
+}
+
 /* Allocate chain of dst_entry's, attach known xfrm's, calculate
  * all the metrics... Shortly, bundle a bundle.
  */
@@ -99,6 +117,7 @@ __xfrm6_bundle_create(struct xfrm_policy *policy, struct xfrm_state **xfrm, int
        int i;
        int err = 0;
        int header_len = 0;
+       int nfheader_len = 0;
        int trailer_len = 0;
 
        dst = dst_prev = NULL;
@@ -135,7 +154,7 @@ __xfrm6_bundle_create(struct xfrm_policy *policy, struct xfrm_state **xfrm, int
                        local  = __xfrm6_bundle_addr_local(xfrm[i], local);
                        tunnel = 1;
                }
-               header_len += xfrm[i]->props.header_len;
+               __xfrm6_bundle_len_inc(&header_len, &nfheader_len, xfrm[i]);
                trailer_len += xfrm[i]->props.trailer_len;
 
                if (tunnel) {
@@ -170,6 +189,7 @@ __xfrm6_bundle_create(struct xfrm_policy *policy, struct xfrm_state **xfrm, int
                dst_prev->flags        |= DST_HOST;
                dst_prev->lastuse       = jiffies;
                dst_prev->header_len    = header_len;
+               dst_prev->nfheader_len  = nfheader_len;
                dst_prev->trailer_len   = trailer_len;
                memcpy(&dst_prev->metrics, &x->route->metrics, sizeof(dst_prev->metrics));
 
@@ -188,7 +208,7 @@ __xfrm6_bundle_create(struct xfrm_policy *policy, struct xfrm_state **xfrm, int
                x->u.rt6.rt6i_src      = rt0->rt6i_src; 
                x->u.rt6.rt6i_idev     = rt0->rt6i_idev;
                in6_dev_hold(rt0->rt6i_idev);
-               header_len -= x->u.dst.xfrm->props.header_len;
+               __xfrm6_bundle_len_dec(&header_len, &nfheader_len, x->u.dst.xfrm);
                trailer_len -= x->u.dst.xfrm->props.trailer_len;
        }