Commit 1b5c2299 authored by Masahide NAKAMURA's avatar Masahide NAKAMURA Committed by David S. Miller
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[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: default avatarMasahide NAKAMURA <nakam@linux-ipv6.org>
Signed-off-by: default avatarYOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 99505a84

include/net/dst.h

+1 −0
Original line number Diff line number Diff line
@@ -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];

include/net/xfrm.h

+2 −0
Original line number Diff line number Diff line
@@ -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 *);

net/ipv4/xfrm4_policy.c

+1 −0
Original line number Diff line number Diff line
@@ -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));

net/ipv6/ip6_output.c

+1 −1
Original line number Diff line number Diff line
@@ -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) {

net/ipv6/xfrm6_policy.c

+22 −2
Original line number Diff line number Diff line
@@ -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;

	}

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