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Commit 4165079b authored by Florian Westphal's avatar Florian Westphal Committed by David S. Miller
Browse files

net: switch secpath to use skb extension infrastructure 



Remove skb->sp and allocate secpath storage via extension
infrastructure.  This also reduces sk_buff by 8 bytes on x86_64.

Total size of allyesconfig kernel is reduced slightly, as there is
less inlined code (one conditional atomic op instead of two on
skb_clone).

No differences in throughput in following ipsec performance tests:
- transport mode with aes on 10GB link
- tunnel mode between two network namespaces with aes and null cipher

Signed-off-by: default avatarFlorian Westphal <fw@strlen.de>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent a84e3f53

Documentation/networking/xfrm_device.txt

+4 −3
Original line number Diff line number Diff line
@@ -111,9 +111,10 @@ the stack in xfrm_input(). 
		xfrm_state_hold(xs);



	store the state information into the skb

		skb->sp = secpath_dup(skb->sp);

		skb->sp->xvec[skb->sp->len++] = xs;

		skb->sp->olen++;

		sp = secpath_set(skb);

		if (!sp) return;

		sp->xvec[sp->len++] = xs;

		sp->olen++;



	indicate the success and/or error status of the offload

		xo = xfrm_offload(skb);

include/linux/skbuff.h

+5 −5
Original line number Diff line number Diff line
@@ -714,9 +714,6 @@ struct sk_buff { 
		struct list_head	tcp_tsorted_anchor;

	};



#ifdef CONFIG_XFRM

	struct	sec_path	*sp;

#endif

#if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)

	unsigned long		 _nfct;

#endif
@@ -3907,6 +3904,9 @@ static inline void nf_conntrack_get(struct nf_conntrack *nfct) 
enum skb_ext_id {

#if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)

	SKB_EXT_BRIDGE_NF,

#endif

#ifdef CONFIG_XFRM

	SKB_EXT_SEC_PATH,

#endif

	SKB_EXT_NUM, /* must be last */

};
@@ -4069,7 +4069,7 @@ static inline void skb_init_secmark(struct sk_buff *skb) 
static inline int secpath_exists(const struct sk_buff *skb)

{

#ifdef CONFIG_XFRM

	return skb->sp != NULL;

	return skb_ext_exist(skb, SKB_EXT_SEC_PATH);

#else

	return 0;

#endif
@@ -4127,7 +4127,7 @@ static inline bool skb_get_dst_pending_confirm(const struct sk_buff *skb) 
static inline struct sec_path *skb_sec_path(const struct sk_buff *skb)

{

#ifdef CONFIG_XFRM

	return skb->sp;

	return skb_ext_find(skb, SKB_EXT_SEC_PATH);

#else

	return NULL;

#endif

include/net/xfrm.h

+1 −21
Original line number Diff line number Diff line
@@ -1096,7 +1096,6 @@ struct xfrm_offload { 
};



struct sec_path {

	refcount_t		refcnt;

	int			len;

	int			olen;
@@ -1104,32 +1103,13 @@ struct sec_path { 
	struct xfrm_offload	ovec[XFRM_MAX_OFFLOAD_DEPTH];

};



static inline struct sec_path *

secpath_get(struct sec_path *sp)

{

	if (sp)

		refcount_inc(&sp->refcnt);

	return sp;

}



void __secpath_destroy(struct sec_path *sp);



static inline void

secpath_put(struct sec_path *sp)

{

	if (sp && refcount_dec_and_test(&sp->refcnt))

		__secpath_destroy(sp);

}



struct sec_path *secpath_dup(struct sec_path *src);

struct sec_path *secpath_set(struct sk_buff *skb);



static inline void

secpath_reset(struct sk_buff *skb)

{

#ifdef CONFIG_XFRM

	secpath_put(skb->sp);

	skb->sp = NULL;

	skb_ext_del(skb, SKB_EXT_SEC_PATH);

#endif

}

net/core/skbuff.c

+41 −6
Original line number Diff line number Diff line
@@ -609,7 +609,6 @@ static void kfree_skbmem(struct sk_buff *skb) 
void skb_release_head_state(struct sk_buff *skb)

{

	skb_dst_drop(skb);

	secpath_reset(skb);

	if (skb->destructor) {

		WARN_ON(in_irq());

		skb->destructor(skb);
@@ -798,9 +797,6 @@ static void __copy_skb_header(struct sk_buff *new, const struct sk_buff *old) 
	memcpy(new->cb, old->cb, sizeof(old->cb));

	skb_dst_copy(new, old);

	__skb_ext_copy(new, old);

#ifdef CONFIG_XFRM

	new->sp			= secpath_get(old->sp);

#endif

	__nf_copy(new, old, false);



	/* Note : this field could be in headers_start/headers_end section
@@ -3912,6 +3908,9 @@ static const u8 skb_ext_type_len[] = { 
#if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)

	[SKB_EXT_BRIDGE_NF] = SKB_EXT_CHUNKSIZEOF(struct nf_bridge_info),

#endif

#ifdef CONFIG_XFRM

	[SKB_EXT_SEC_PATH] = SKB_EXT_CHUNKSIZEOF(struct sec_path),

#endif

};



static __always_inline unsigned int skb_ext_total_length(void)
@@ -3919,6 +3918,9 @@ static __always_inline unsigned int skb_ext_total_length(void) 
	return SKB_EXT_CHUNKSIZEOF(struct skb_ext) +

#if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)

		skb_ext_type_len[SKB_EXT_BRIDGE_NF] +

#endif

#ifdef CONFIG_XFRM

		skb_ext_type_len[SKB_EXT_SEC_PATH] +

#endif

		0;

}
@@ -5610,7 +5612,8 @@ static struct skb_ext *skb_ext_alloc(void) 
	return new;

}



static struct skb_ext *skb_ext_maybe_cow(struct skb_ext *old)

static struct skb_ext *skb_ext_maybe_cow(struct skb_ext *old,

					 unsigned int old_active)

{

	struct skb_ext *new;
@@ -5624,6 +5627,15 @@ static struct skb_ext *skb_ext_maybe_cow(struct skb_ext *old) 
	memcpy(new, old, old->chunks * SKB_EXT_ALIGN_VALUE);

	refcount_set(&new->refcnt, 1);



#ifdef CONFIG_XFRM

	if (old_active & (1 << SKB_EXT_SEC_PATH)) {

		struct sec_path *sp = skb_ext_get_ptr(old, SKB_EXT_SEC_PATH);

		unsigned int i;



		for (i = 0; i < sp->len; i++)

			xfrm_state_hold(sp->xvec[i]);

	}

#endif

	__skb_ext_put(old);

	return new;

}
@@ -5650,7 +5662,7 @@ void *skb_ext_add(struct sk_buff *skb, enum skb_ext_id id) 
	if (skb->active_extensions) {

		old = skb->extensions;



		new = skb_ext_maybe_cow(old);

		new = skb_ext_maybe_cow(old, skb->active_extensions);

		if (!new)

			return NULL;
@@ -5679,6 +5691,16 @@ void *skb_ext_add(struct sk_buff *skb, enum skb_ext_id id) 
}

EXPORT_SYMBOL(skb_ext_add);



#ifdef CONFIG_XFRM

static void skb_ext_put_sp(struct sec_path *sp)

{

	unsigned int i;



	for (i = 0; i < sp->len; i++)

		xfrm_state_put(sp->xvec[i]);

}

#endif



void __skb_ext_del(struct sk_buff *skb, enum skb_ext_id id)

{

	struct skb_ext *ext = skb->extensions;
@@ -5687,6 +5709,14 @@ void __skb_ext_del(struct sk_buff *skb, enum skb_ext_id id) 
	if (skb->active_extensions == 0) {

		skb->extensions = NULL;

		__skb_ext_put(ext);

#ifdef CONFIG_XFRM

	} else if (id == SKB_EXT_SEC_PATH &&

		   refcount_read(&ext->refcnt) == 1) {

		struct sec_path *sp = skb_ext_get_ptr(ext, SKB_EXT_SEC_PATH);



		skb_ext_put_sp(sp);

		sp->len = 0;

#endif

	}

}

EXPORT_SYMBOL(__skb_ext_del);
@@ -5702,6 +5732,11 @@ void __skb_ext_put(struct skb_ext *ext) 
	if (!refcount_dec_and_test(&ext->refcnt))

		return;

free_now:

#ifdef CONFIG_XFRM

	if (__skb_ext_exist(ext, SKB_EXT_SEC_PATH))

		skb_ext_put_sp(skb_ext_get_ptr(ext, SKB_EXT_SEC_PATH));

#endif



	kmem_cache_free(skbuff_ext_cache, ext);

}

EXPORT_SYMBOL(__skb_ext_put);

net/xfrm/xfrm_input.c

+8 −48
Original line number Diff line number Diff line
@@ -38,8 +38,6 @@ struct xfrm_trans_cb { 


#define XFRM_TRANS_SKB_CB(__skb) ((struct xfrm_trans_cb *)&((__skb)->cb[0]))



static struct kmem_cache *secpath_cachep __ro_after_init;



static DEFINE_SPINLOCK(xfrm_input_afinfo_lock);

static struct xfrm_input_afinfo const __rcu *xfrm_input_afinfo[AF_INET6 + 1];
@@ -111,54 +109,21 @@ static int xfrm_rcv_cb(struct sk_buff *skb, unsigned int family, u8 protocol, 
	return ret;

}



void __secpath_destroy(struct sec_path *sp)

{

	int i;

	for (i = 0; i < sp->len; i++)

		xfrm_state_put(sp->xvec[i]);

	kmem_cache_free(secpath_cachep, sp);

}

EXPORT_SYMBOL(__secpath_destroy);



struct sec_path *secpath_dup(struct sec_path *src)

struct sec_path *secpath_set(struct sk_buff *skb)

{

	struct sec_path *sp;

	struct sec_path *sp, *tmp = skb_ext_find(skb, SKB_EXT_SEC_PATH);



	sp = kmem_cache_alloc(secpath_cachep, GFP_ATOMIC);

	sp = skb_ext_add(skb, SKB_EXT_SEC_PATH);

	if (!sp)

		return NULL;



	sp->len = 0;

	sp->olen = 0;



	memset(sp->ovec, 0, sizeof(sp->ovec));



	if (src) {

		int i;



		memcpy(sp, src, sizeof(*sp));

		for (i = 0; i < sp->len; i++)

			xfrm_state_hold(sp->xvec[i]);

	}

	refcount_set(&sp->refcnt, 1);

	if (tmp) /* reused existing one (was COW'd if needed) */

		return sp;

}

EXPORT_SYMBOL(secpath_dup);



struct sec_path *secpath_set(struct sk_buff *skb)

{

	struct sec_path *sp = skb->sp;



	/* Allocate new secpath or COW existing one. */

	if (!sp || refcount_read(&sp->refcnt) != 1) {

		sp = secpath_dup(skb->sp);

		if (!sp)

			return NULL;



		if (skb->sp)

			secpath_put(skb->sp);

		skb->sp = sp;

	}

	/* allocated new secpath */

	memset(sp->ovec, 0, sizeof(sp->ovec));

	sp->olen = 0;

	sp->len = 0;



	return sp;

}
@@ -552,11 +517,6 @@ void __init xfrm_input_init(void) 
	if (err)

		gro_cells.cells = NULL;



	secpath_cachep = kmem_cache_create("secpath_cache",

					   sizeof(struct sec_path),

					   0, SLAB_HWCACHE_ALIGN|SLAB_PANIC,

					   NULL);



	for_each_possible_cpu(i) {

		struct xfrm_trans_tasklet *trans;