Commit 372ab5a5 authored by Jakub Kicinski's avatar Jakub Kicinski
Browse files

Merge branch 'flexible-array-for-ip-tunnel-options' 

Gal Pressman says:

====================
Flexible array for ip tunnel options

Remove the hidden assumption that options are allocated at the end of
the struct, and teach the compiler about them using a flexible array.

First patch is converting hard-coded 'info + 1' to use ip_tunnel_info()
helper.
Second patch adds the 'options' flexible array and changes the helper to
use it.

v4: https://lore.kernel.org/20250217202503.265318-1-gal@nvidia.com
v3: https://lore.kernel.org/20250212140953.107533-1-gal@nvidia.com
v2: https://lore.kernel.org/20250209101853.15828-1-gal@nvidia.com
====================

Link: https://patch.msgid.link/20250219143256.370277-1-gal@nvidia.com


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parents 5d6ba5ab bb5e62f2

include/net/dst_metadata.h

+2 −5
Original line number Diff line number Diff line
@@ -163,11 +163,8 @@ static inline struct metadata_dst *tun_dst_unclone(struct sk_buff *skb) 
	if (!new_md)

		return ERR_PTR(-ENOMEM);



	unsafe_memcpy(&new_md->u.tun_info, &md_dst->u.tun_info,

		      sizeof(struct ip_tunnel_info) + md_size,

		      /* metadata_dst_alloc() reserves room (md_size bytes) for

		       * options right after the ip_tunnel_info struct.

		       */);

	memcpy(&new_md->u.tun_info, &md_dst->u.tun_info,

	       sizeof(struct ip_tunnel_info) + md_size);

#ifdef CONFIG_DST_CACHE

	/* Unclone the dst cache if there is one */

	if (new_md->u.tun_info.dst_cache.cache) {

include/net/ip_tunnels.h

+4 −3
Original line number Diff line number Diff line
@@ -95,8 +95,8 @@ struct ip_tunnel_encap { 


#define ip_tunnel_info_opts(info)				\

	_Generic(info,						\

		 const struct ip_tunnel_info * : ((const void *)((info) + 1)),\

		 struct ip_tunnel_info * : ((void *)((info) + 1))\

		 const struct ip_tunnel_info * : ((const void *)(info)->options),\

		 struct ip_tunnel_info * : ((void *)(info)->options)\

	)



struct ip_tunnel_info {
@@ -107,6 +107,7 @@ struct ip_tunnel_info { 
#endif

	u8			options_len;

	u8			mode;

	u8			options[] __aligned_largest __counted_by(options_len);

};



/* 6rd prefix/relay information */
@@ -650,7 +651,7 @@ static inline void iptunnel_xmit_stats(struct net_device *dev, int pkt_len) 
static inline void ip_tunnel_info_opts_get(void *to,

					   const struct ip_tunnel_info *info)

{

	memcpy(to, info + 1, info->options_len);

	memcpy(to, ip_tunnel_info_opts(info), info->options_len);

}



static inline void ip_tunnel_info_opts_set(struct ip_tunnel_info *info,

net/core/dst.c

+4 −2
Original line number Diff line number Diff line
@@ -286,7 +286,8 @@ struct metadata_dst *metadata_dst_alloc(u8 optslen, enum metadata_type type, 
{

	struct metadata_dst *md_dst;



	md_dst = kmalloc(sizeof(*md_dst) + optslen, flags);

	md_dst = kmalloc(struct_size(md_dst, u.tun_info.options, optslen),

			 flags);

	if (!md_dst)

		return NULL;
@@ -314,7 +315,8 @@ metadata_dst_alloc_percpu(u8 optslen, enum metadata_type type, gfp_t flags) 
	int cpu;

	struct metadata_dst __percpu *md_dst;



	md_dst = __alloc_percpu_gfp(sizeof(struct metadata_dst) + optslen,

	md_dst = __alloc_percpu_gfp(struct_size(md_dst, u.tun_info.options,

						optslen),

				    __alignof__(struct metadata_dst), flags);

	if (!md_dst)

		return NULL;

net/sched/act_tunnel_key.c

+4 −4
Original line number Diff line number Diff line
@@ -571,8 +571,8 @@ static void tunnel_key_release(struct tc_action *a) 
static int tunnel_key_geneve_opts_dump(struct sk_buff *skb,

				       const struct ip_tunnel_info *info)

{

	const u8 *src = ip_tunnel_info_opts(info);

	int len = info->options_len;

	u8 *src = (u8 *)(info + 1);

	struct nlattr *start;



	start = nla_nest_start_noflag(skb, TCA_TUNNEL_KEY_ENC_OPTS_GENEVE);
@@ -580,7 +580,7 @@ static int tunnel_key_geneve_opts_dump(struct sk_buff *skb, 
		return -EMSGSIZE;



	while (len > 0) {

		struct geneve_opt *opt = (struct geneve_opt *)src;

		const struct geneve_opt *opt = (const struct geneve_opt *)src;



		if (nla_put_be16(skb, TCA_TUNNEL_KEY_ENC_OPT_GENEVE_CLASS,

				 opt->opt_class) ||
@@ -603,7 +603,7 @@ static int tunnel_key_geneve_opts_dump(struct sk_buff *skb, 
static int tunnel_key_vxlan_opts_dump(struct sk_buff *skb,

				      const struct ip_tunnel_info *info)

{

	struct vxlan_metadata *md = (struct vxlan_metadata *)(info + 1);

	const struct vxlan_metadata *md = ip_tunnel_info_opts(info);

	struct nlattr *start;



	start = nla_nest_start_noflag(skb, TCA_TUNNEL_KEY_ENC_OPTS_VXLAN);
@@ -622,7 +622,7 @@ static int tunnel_key_vxlan_opts_dump(struct sk_buff *skb, 
static int tunnel_key_erspan_opts_dump(struct sk_buff *skb,

				       const struct ip_tunnel_info *info)

{

	struct erspan_metadata *md = (struct erspan_metadata *)(info + 1);

	const struct erspan_metadata *md = ip_tunnel_info_opts(info);

	struct nlattr *start;



	start = nla_nest_start_noflag(skb, TCA_TUNNEL_KEY_ENC_OPTS_ERSPAN);