xfrm: store xfrm_mode directly, not its address

This structure is now only 4 bytes, so its more efficient
to cache a copy rather than its address.

No significant size difference in allmodconfig vmlinux.

With non-modular kernel that has all XFRM options enabled, this
series reduces vmlinux image size by ~11kb. All xfrm_mode
indirections are gone and all modes are built-in.

before (ipsec-next master):
    text      data      bss         dec   filename
21071494   7233140 11104324    39408958   vmlinux.master

after this series:
21066448   7226772 11104324    39397544   vmlinux.patched

With allmodconfig kernel, the size increase is only 362 bytes,
even all the xfrm config options removed in this series are
modular.

before:
    text      data     bss      dec   filename
15731286   6936912 4046908 26715106   vmlinux.master

after this series:
15731492   6937068  4046908  26715468 vmlinux
Signed-off-by: Florian Westphal <fw@strlen.de>
Reviewed-by: Sabrina Dubroca <sd@queasysnail.net>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>

include/net/xfrm.h

@@ -132,6 +132,17 @@ struct xfrm_state_offload {
 	u8			flags;
 };
 
+struct xfrm_mode {
+	u8 encap;
+	u8 family;
+	u8 flags;
+};
+
+/* Flags for xfrm_mode. */
+enum {
+	XFRM_MODE_FLAG_TUNNEL = 1,
+};
+
 /* Full description of state of transformer. */
 struct xfrm_state {
 	possible_net_t		xs_net;
@@ -234,9 +245,9 @@ struct xfrm_state {
 	/* Reference to data common to all the instances of this
 	 * transformer. */
 	const struct xfrm_type	*type;
-	const struct xfrm_mode	*inner_mode;
-	const struct xfrm_mode	*inner_mode_iaf;
-	const struct xfrm_mode	*outer_mode;
+	struct xfrm_mode	inner_mode;
+	struct xfrm_mode	inner_mode_iaf;
+	struct xfrm_mode	outer_mode;
 
 	const struct xfrm_type_offload	*type_offload;
 
@@ -421,17 +432,6 @@ struct xfrm_type_offload {
 int xfrm_register_type_offload(const struct xfrm_type_offload *type, unsigned short family);
 int xfrm_unregister_type_offload(const struct xfrm_type_offload *type, unsigned short family);
 
-struct xfrm_mode {
-	u8 encap;
-	u8 family;
-	u8 flags;
-};
-
-/* Flags for xfrm_mode. */
-enum {
-	XFRM_MODE_FLAG_TUNNEL = 1,
-};
-
 static inline int xfrm_af2proto(unsigned int family)
 {
 	switch(family) {
@@ -448,9 +448,9 @@ static inline const struct xfrm_mode *xfrm_ip2inner_mode(struct xfrm_state *x, i
 {
 	if ((ipproto == IPPROTO_IPIP && x->props.family == AF_INET) ||
 	    (ipproto == IPPROTO_IPV6 && x->props.family == AF_INET6))
-		return x->inner_mode;
+		return &x->inner_mode;
 	else
-		return x->inner_mode_iaf;
+		return &x->inner_mode_iaf;
 }
 
 struct xfrm_tmpl {
@@ -1990,7 +1990,7 @@ static inline int xfrm_tunnel_check(struct sk_buff *skb, struct xfrm_state *x,
 			tunnel = true;
 		break;
 	}
-	if (tunnel && !(x->outer_mode->flags & XFRM_MODE_FLAG_TUNNEL))
+	if (tunnel && !(x->outer_mode.flags & XFRM_MODE_FLAG_TUNNEL))
 		return -EINVAL;
 
 	return 0;

net/ipv4/esp4_offload.c

@@ -135,7 +135,7 @@ static struct sk_buff *xfrm4_outer_mode_gso_segment(struct xfrm_state *x,
 						    struct sk_buff *skb,
 						    netdev_features_t features)
 {
-	switch (x->outer_mode->encap) {
+	switch (x->outer_mode.encap) {
 	case XFRM_MODE_TUNNEL:
 		return xfrm4_tunnel_gso_segment(x, skb, features);
 	case XFRM_MODE_TRANSPORT:

net/ipv4/ip_vti.c

@@ -126,7 +126,7 @@ static int vti_rcv_cb(struct sk_buff *skb, int err)
 
 	x = xfrm_input_state(skb);
 
-	inner_mode = x->inner_mode;
+	inner_mode = &x->inner_mode;
 
 	if (x->sel.family == AF_UNSPEC) {
 		inner_mode = xfrm_ip2inner_mode(x, XFRM_MODE_SKB_CB(skb)->protocol);

net/ipv4/xfrm4_output.c

@@ -83,7 +83,7 @@ static int __xfrm4_output(struct net *net, struct sock *sk, struct sk_buff *skb)
 #endif
 
 	rcu_read_lock();
-	afinfo = xfrm_state_afinfo_get_rcu(x->outer_mode->family);
+	afinfo = xfrm_state_afinfo_get_rcu(x->outer_mode.family);
 	if (likely(afinfo))
 		ret = afinfo->output_finish(sk, skb);
 	else

net/ipv6/esp6_offload.c

@@ -162,7 +162,7 @@ static struct sk_buff *xfrm6_outer_mode_gso_segment(struct xfrm_state *x,
 						    struct sk_buff *skb,
 						    netdev_features_t features)
 {
-	switch (x->outer_mode->encap) {
+	switch (x->outer_mode.encap) {
 	case XFRM_MODE_TUNNEL:
 		return xfrm6_tunnel_gso_segment(x, skb, features);
 	case XFRM_MODE_TRANSPORT:

net/ipv6/ip6_vti.c

@@ -361,7 +361,7 @@ static int vti6_rcv_cb(struct sk_buff *skb, int err)
 
 	x = xfrm_input_state(skb);
 
-	inner_mode = x->inner_mode;
+	inner_mode = &x->inner_mode;
 
 	if (x->sel.family == AF_UNSPEC) {
 		inner_mode = xfrm_ip2inner_mode(x, XFRM_MODE_SKB_CB(skb)->protocol);

net/ipv6/xfrm6_output.c

@@ -129,7 +129,7 @@ static int __xfrm6_output_state_finish(struct xfrm_state *x, struct sock *sk,
 	int ret = -EAFNOSUPPORT;
 
 	rcu_read_lock();
-	afinfo = xfrm_state_afinfo_get_rcu(x->outer_mode->family);
+	afinfo = xfrm_state_afinfo_get_rcu(x->outer_mode.family);
 	if (likely(afinfo))
 		ret = afinfo->output_finish(sk, skb);
 	else

net/xfrm/xfrm_device.c

@@ -53,20 +53,20 @@ static void __xfrm_mode_tunnel_prep(struct xfrm_state *x, struct sk_buff *skb,
 /* Adjust pointers into the packet when IPsec is done at layer2 */
 static void xfrm_outer_mode_prep(struct xfrm_state *x, struct sk_buff *skb)
 {
-	switch (x->outer_mode->encap) {
+	switch (x->outer_mode.encap) {
 	case XFRM_MODE_TUNNEL:
-		if (x->outer_mode->family == AF_INET)
+		if (x->outer_mode.family == AF_INET)
 			return __xfrm_mode_tunnel_prep(x, skb,
 						       sizeof(struct iphdr));
-		if (x->outer_mode->family == AF_INET6)
+		if (x->outer_mode.family == AF_INET6)
 			return __xfrm_mode_tunnel_prep(x, skb,
 						       sizeof(struct ipv6hdr));
 		break;
 	case XFRM_MODE_TRANSPORT:
-		if (x->outer_mode->family == AF_INET)
+		if (x->outer_mode.family == AF_INET)
 			return __xfrm_transport_prep(x, skb,
 						     sizeof(struct iphdr));
-		if (x->outer_mode->family == AF_INET6)
+		if (x->outer_mode.family == AF_INET6)
 			return __xfrm_transport_prep(x, skb,
 						     sizeof(struct ipv6hdr));
 		break;

net/xfrm/xfrm_input.c

@@ -351,12 +351,12 @@ xfrm_inner_mode_encap_remove(struct xfrm_state *x,
 
 static int xfrm_prepare_input(struct xfrm_state *x, struct sk_buff *skb)
 {
-	const struct xfrm_mode *inner_mode = x->inner_mode;
+	const struct xfrm_mode *inner_mode = &x->inner_mode;
 	const struct xfrm_state_afinfo *afinfo;
 	int err = -EAFNOSUPPORT;
 
 	rcu_read_lock();
-	afinfo = xfrm_state_afinfo_get_rcu(x->outer_mode->family);
+	afinfo = xfrm_state_afinfo_get_rcu(x->outer_mode.family);
 	if (likely(afinfo))
 		err = afinfo->extract_input(x, skb);
 
@@ -482,7 +482,7 @@ int xfrm_input(struct sk_buff *skb, int nexthdr, __be32 spi, int encap_type)
 			goto drop;
 		}
 
-		family = x->outer_mode->family;
+		family = x->outer_mode.family;
 
 		/* An encap_type of -1 indicates async resumption. */
 		if (encap_type == -1) {
@@ -666,7 +666,7 @@ int xfrm_input(struct sk_buff *skb, int nexthdr, __be32 spi, int encap_type)
 
 		XFRM_MODE_SKB_CB(skb)->protocol = nexthdr;
 
-		inner_mode = x->inner_mode;
+		inner_mode = &x->inner_mode;
 
 		if (x->sel.family == AF_UNSPEC) {
 			inner_mode = xfrm_ip2inner_mode(x, XFRM_MODE_SKB_CB(skb)->protocol);
@@ -681,7 +681,7 @@ int xfrm_input(struct sk_buff *skb, int nexthdr, __be32 spi, int encap_type)
 			goto drop;
 		}
 
-		if (x->outer_mode->flags & XFRM_MODE_FLAG_TUNNEL) {
+		if (x->outer_mode.flags & XFRM_MODE_FLAG_TUNNEL) {
 			decaps = 1;
 			break;
 		}
@@ -691,7 +691,7 @@ int xfrm_input(struct sk_buff *skb, int nexthdr, __be32 spi, int encap_type)
 		 * transport mode so the outer address is identical.
 		 */
 		daddr = &x->id.daddr;
-		family = x->outer_mode->family;
+		family = x->outer_mode.family;
 
 		err = xfrm_parse_spi(skb, nexthdr, &spi, &seq);
 		if (err < 0) {
@@ -721,7 +721,7 @@ int xfrm_input(struct sk_buff *skb, int nexthdr, __be32 spi, int encap_type)
 
 		err = -EAFNOSUPPORT;
 		rcu_read_lock();
-		afinfo = xfrm_state_afinfo_get_rcu(x->inner_mode->family);
+		afinfo = xfrm_state_afinfo_get_rcu(x->inner_mode.family);
 		if (likely(afinfo))
 			err = afinfo->transport_finish(skb, xfrm_gro || async);
 		rcu_read_unlock();

net/xfrm/xfrm_interface.c

@@ -273,7 +273,7 @@ static int xfrmi_rcv_cb(struct sk_buff *skb, int err)
 	xnet = !net_eq(xi->net, dev_net(skb->dev));
 
 	if (xnet) {
-		inner_mode = x->inner_mode;
+		inner_mode = &x->inner_mode;
 
 		if (x->sel.family == AF_UNSPEC) {
 			inner_mode = xfrm_ip2inner_mode(x, XFRM_MODE_SKB_CB(skb)->protocol);

net/xfrm/xfrm_output.c

@@ -334,7 +334,7 @@ static int xfrm4_prepare_output(struct xfrm_state *x, struct sk_buff *skb)
 	IPCB(skb)->flags |= IPSKB_XFRM_TUNNEL_SIZE;
 	skb->protocol = htons(ETH_P_IP);
 
-	switch (x->outer_mode->encap) {
+	switch (x->outer_mode.encap) {
 	case XFRM_MODE_BEET:
 		return xfrm4_beet_encap_add(x, skb);
 	case XFRM_MODE_TUNNEL:
@@ -357,7 +357,7 @@ static int xfrm6_prepare_output(struct xfrm_state *x, struct sk_buff *skb)
 	skb->ignore_df = 1;
 	skb->protocol = htons(ETH_P_IPV6);
 
-	switch (x->outer_mode->encap) {
+	switch (x->outer_mode.encap) {
 	case XFRM_MODE_BEET:
 		return xfrm6_beet_encap_add(x, skb);
 	case XFRM_MODE_TUNNEL:
@@ -373,22 +373,22 @@ static int xfrm6_prepare_output(struct xfrm_state *x, struct sk_buff *skb)
 
 static int xfrm_outer_mode_output(struct xfrm_state *x, struct sk_buff *skb)
 {
-	switch (x->outer_mode->encap) {
+	switch (x->outer_mode.encap) {
 	case XFRM_MODE_BEET:
 	case XFRM_MODE_TUNNEL:
-		if (x->outer_mode->family == AF_INET)
+		if (x->outer_mode.family == AF_INET)
 			return xfrm4_prepare_output(x, skb);
-		if (x->outer_mode->family == AF_INET6)
+		if (x->outer_mode.family == AF_INET6)
 			return xfrm6_prepare_output(x, skb);
 		break;
 	case XFRM_MODE_TRANSPORT:
-		if (x->outer_mode->family == AF_INET)
+		if (x->outer_mode.family == AF_INET)
 			return xfrm4_transport_output(x, skb);
-		if (x->outer_mode->family == AF_INET6)
+		if (x->outer_mode.family == AF_INET6)
 			return xfrm6_transport_output(x, skb);
 		break;
 	case XFRM_MODE_ROUTEOPTIMIZATION:
-		if (x->outer_mode->family == AF_INET6)
+		if (x->outer_mode.family == AF_INET6)
 			return xfrm6_ro_output(x, skb);
 		WARN_ON_ONCE(1);
 		break;
@@ -489,7 +489,7 @@ static int xfrm_output_one(struct sk_buff *skb, int err)
 		}
 		skb_dst_set(skb, dst);
 		x = dst->xfrm;
-	} while (x && !(x->outer_mode->flags & XFRM_MODE_FLAG_TUNNEL));
+	} while (x && !(x->outer_mode.flags & XFRM_MODE_FLAG_TUNNEL));
 
 	return 0;
 
@@ -626,7 +626,7 @@ static int xfrm_inner_extract_output(struct xfrm_state *x, struct sk_buff *skb)
 		inner_mode = xfrm_ip2inner_mode(x,
 				xfrm_af2proto(skb_dst(skb)->ops->family));
 	else
-		inner_mode = x->inner_mode;
+		inner_mode = &x->inner_mode;
 
 	if (inner_mode == NULL)
 		return -EAFNOSUPPORT;

net/xfrm/xfrm_policy.c

@@ -2595,7 +2595,7 @@ static struct dst_entry *xfrm_bundle_create(struct xfrm_policy *policy,
 				goto put_states;
 			}
 		} else
-			inner_mode = xfrm[i]->inner_mode;
+			inner_mode = &xfrm[i]->inner_mode;
 
 		xdst->route = dst;
 		dst_copy_metrics(dst1, dst);

net/xfrm/xfrm_state.c

@@ -551,8 +551,6 @@ struct xfrm_state *xfrm_state_alloc(struct net *net)
 		x->lft.hard_packet_limit = XFRM_INF;
 		x->replay_maxage = 0;
 		x->replay_maxdiff = 0;
-		x->inner_mode = NULL;
-		x->inner_mode_iaf = NULL;
 		spin_lock_init(&x->lock);
 	}
 	return x;
@@ -2204,8 +2202,9 @@ int xfrm_state_mtu(struct xfrm_state *x, int mtu)
 
 int __xfrm_init_state(struct xfrm_state *x, bool init_replay, bool offload)
 {
-	const struct xfrm_mode *inner_mode;
 	const struct xfrm_state_afinfo *afinfo;
+	const struct xfrm_mode *inner_mode;
+	const struct xfrm_mode *outer_mode;
 	int family = x->props.family;
 	int err;
 
@@ -2234,7 +2233,7 @@ int __xfrm_init_state(struct xfrm_state *x, bool init_replay, bool offload)
 		    family != x->sel.family)
 			goto error;
 
-		x->inner_mode = inner_mode;
+		x->inner_mode = *inner_mode;
 	} else {
 		const struct xfrm_mode *inner_mode_iaf;
 		int iafamily = AF_INET;
@@ -2246,7 +2245,7 @@ int __xfrm_init_state(struct xfrm_state *x, bool init_replay, bool offload)
 		if (!(inner_mode->flags & XFRM_MODE_FLAG_TUNNEL))
 			goto error;
 
-		x->inner_mode = inner_mode;
+		x->inner_mode = *inner_mode;
 
 		if (x->props.family == AF_INET)
 			iafamily = AF_INET6;
@@ -2254,7 +2253,7 @@ int __xfrm_init_state(struct xfrm_state *x, bool init_replay, bool offload)
 		inner_mode_iaf = xfrm_get_mode(x->props.mode, iafamily);
 		if (inner_mode_iaf) {
 			if (inner_mode_iaf->flags & XFRM_MODE_FLAG_TUNNEL)
-				x->inner_mode_iaf = inner_mode_iaf;
+				x->inner_mode_iaf = *inner_mode_iaf;
 		}
 	}
 
@@ -2268,12 +2267,13 @@ int __xfrm_init_state(struct xfrm_state *x, bool init_replay, bool offload)
 	if (err)
 		goto error;
 
-	x->outer_mode = xfrm_get_mode(x->props.mode, family);
-	if (x->outer_mode == NULL) {
+	outer_mode = xfrm_get_mode(x->props.mode, family);
+	if (!outer_mode) {
 		err = -EPROTONOSUPPORT;
 		goto error;
 	}
 
+	x->outer_mode = *outer_mode;
 	if (init_replay) {
 		err = xfrm_init_replay(x);
 		if (err)