Commit 80b30c10 authored by Herbert Xu's avatar Herbert Xu Committed by Arnaldo Carvalho de Melo
Browse files

[IPSEC]: Kill obsolete get_mss function 



Now that we've switched over to storing MTUs in the xfrm_dst entries,
we no longer need the dst's get_mss methods.  This patch gets rid of
them.

It also documents the fact that our MTU calculation is not optimal
for ESP.

Signed-off-by: default avatarHerbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@mandriva.com>
parent 1371e37d

include/net/dst.h

+0 −1
Original line number Diff line number Diff line
@@ -94,7 +94,6 @@ struct dst_ops 
	struct dst_entry *	(*negative_advice)(struct dst_entry *);

	void			(*link_failure)(struct sk_buff *);

	void			(*update_pmtu)(struct dst_entry *dst, u32 mtu);

	int			(*get_mss)(struct dst_entry *dst, u32 mtu);

	int			entry_size;



	atomic_t		entries;

net/xfrm/xfrm_policy.c

+0 −43
Original line number Diff line number Diff line
@@ -1192,46 +1192,6 @@ int xfrm_bundle_ok(struct xfrm_dst *first, struct flowi *fl, int family) 


EXPORT_SYMBOL(xfrm_bundle_ok);



/* Well... that's _TASK_. We need to scan through transformation

 * list and figure out what mss tcp should generate in order to

 * final datagram fit to mtu. Mama mia... :-)

 *

 * Apparently, some easy way exists, but we used to choose the most

 * bizarre ones. :-) So, raising Kalashnikov... tra-ta-ta.

 *

 * Consider this function as something like dark humour. :-)

 */

static int xfrm_get_mss(struct dst_entry *dst, u32 mtu)

{

	int res = mtu - dst->header_len;



	for (;;) {

		struct dst_entry *d = dst;

		int m = res;



		do {

			struct xfrm_state *x = d->xfrm;

			if (x) {

				spin_lock_bh(&x->lock);

				if (x->km.state == XFRM_STATE_VALID &&

				    x->type && x->type->get_max_size)

					m = x->type->get_max_size(d->xfrm, m);

				else

					m += x->props.header_len;

				spin_unlock_bh(&x->lock);

			}

		} while ((d = d->child) != NULL);



		if (m <= mtu)

			break;

		res -= (m - mtu);

		if (res < 88)

			return mtu;

	}



	return res + dst->header_len;

}



int xfrm_policy_register_afinfo(struct xfrm_policy_afinfo *afinfo)

{

	int err = 0;
@@ -1252,8 +1212,6 @@ int xfrm_policy_register_afinfo(struct xfrm_policy_afinfo *afinfo) 
			dst_ops->negative_advice = xfrm_negative_advice;

		if (likely(dst_ops->link_failure == NULL))

			dst_ops->link_failure = xfrm_link_failure;

		if (likely(dst_ops->get_mss == NULL))

			dst_ops->get_mss = xfrm_get_mss;

		if (likely(afinfo->garbage_collect == NULL))

			afinfo->garbage_collect = __xfrm_garbage_collect;

		xfrm_policy_afinfo[afinfo->family] = afinfo;
@@ -1281,7 +1239,6 @@ int xfrm_policy_unregister_afinfo(struct xfrm_policy_afinfo *afinfo) 
			dst_ops->check = NULL;

			dst_ops->negative_advice = NULL;

			dst_ops->link_failure = NULL;

			dst_ops->get_mss = NULL;

			afinfo->garbage_collect = NULL;

		}

	}

net/xfrm/xfrm_state.c

+6 −0
Original line number Diff line number Diff line
@@ -1026,6 +1026,12 @@ void xfrm_state_delete_tunnel(struct xfrm_state *x) 
}

EXPORT_SYMBOL(xfrm_state_delete_tunnel);



/*

 * This function is NOT optimal.  For example, with ESP it will give an

 * MTU that's usually two bytes short of being optimal.  However, it will

 * usually give an answer that's a multiple of 4 provided the input is

 * also a multiple of 4.

 */

int xfrm_state_mtu(struct xfrm_state *x, int mtu)

{

	int res = mtu;

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