BACKPORT: xfrm: Extend the output_mark to support input direction and masking.

We already support setting an output mark at the xfrm_state,
unfortunately this does not support the input direction and
masking the marks that will be applied to the skb. This change
adds support applying a masked value in both directions.

The existing XFRMA_OUTPUT_MARK number is reused for this purpose
and as it is now bi-directional, it is renamed to XFRMA_SET_MARK.

An additional XFRMA_SET_MARK_MASK attribute is added for setting the
mask. If the attribute mask not provided, it is set to 0xffffffff,
keeping the XFRMA_OUTPUT_MARK existing 'full mask' semantics.

Co-developed-by: Tobias Brunner <tobias@strongswan.org>
Co-developed-by: Eyal Birger <eyal.birger@gmail.com>
Co-developed-by: Lorenzo Colitti <lorenzo@google.com>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: Tobias Brunner <tobias@strongswan.org>
Signed-off-by: Eyal Birger <eyal.birger@gmail.com>
Signed-off-by: Lorenzo Colitti <lorenzo@google.com>

Conflicts: XFRM OFFLOAD not previously backported; removed incompatible
device offload copying in xfrm_user.c, xfrm_device.c

(cherry picked from commit 9b42c1f179a614e11893ae4619f0304a38f481ae)
Signed-off-by: Benedict Wong <benedictwong@google.com>
Bug: 115914689
Change-Id: I9f554d1697a72ef5668e5251d560cc1ba4d0ab07
diff --git a/net/xfrm/xfrm_input.c b/net/xfrm/xfrm_input.c
index 6e3f025..3f892d3 100644
--- a/net/xfrm/xfrm_input.c
+++ b/net/xfrm/xfrm_input.c
@@ -251,6 +251,8 @@
 			goto drop;
 		}
 
+		skb->mark = xfrm_smark_get(skb->mark, x);
+
 		skb->sp->xvec[skb->sp->len++] = x;
 
 		spin_lock(&x->lock);
diff --git a/net/xfrm/xfrm_output.c b/net/xfrm/xfrm_output.c
index d864a6d..bbe611a 100644
--- a/net/xfrm/xfrm_output.c
+++ b/net/xfrm/xfrm_output.c
@@ -66,8 +66,7 @@
 			goto error_nolock;
 		}
 
-		if (x->props.output_mark)
-			skb->mark = x->props.output_mark;
+		skb->mark = xfrm_smark_get(skb->mark, x);
 
 		err = x->outer_mode->output(x, skb);
 		if (err) {
diff --git a/net/xfrm/xfrm_policy.c b/net/xfrm/xfrm_policy.c
index a812cb0..6d03612 100644
--- a/net/xfrm/xfrm_policy.c
+++ b/net/xfrm/xfrm_policy.c
@@ -1750,10 +1750,11 @@
 		dst_copy_metrics(dst1, dst);
 
 		if (xfrm[i]->props.mode != XFRM_MODE_TRANSPORT) {
+			__u32 mark = xfrm_smark_get(fl->flowi_mark, xfrm[i]);
+
 			family = xfrm[i]->props.family;
 			dst = xfrm_dst_lookup(xfrm[i], tos, fl->flowi_oif,
-					      &saddr, &daddr, family,
-					      xfrm[i]->props.output_mark);
+					      &saddr, &daddr, family, mark);
 			err = PTR_ERR(dst);
 			if (IS_ERR(dst))
 				goto put_states;
diff --git a/net/xfrm/xfrm_user.c b/net/xfrm/xfrm_user.c
index 2ad14be..c2d72e0 100644
--- a/net/xfrm/xfrm_user.c
+++ b/net/xfrm/xfrm_user.c
@@ -527,6 +527,19 @@
 		x->replay_maxdiff = nla_get_u32(rt);
 }
 
+static void xfrm_smark_init(struct nlattr **attrs, struct xfrm_mark *m)
+{
+	if (attrs[XFRMA_SET_MARK]) {
+		m->v = nla_get_u32(attrs[XFRMA_SET_MARK]);
+		if (attrs[XFRMA_SET_MARK_MASK])
+			m->m = nla_get_u32(attrs[XFRMA_SET_MARK_MASK]);
+		else
+			m->m = 0xffffffff;
+	} else {
+		m->v = m->m = 0;
+	}
+}
+
 static struct xfrm_state *xfrm_state_construct(struct net *net,
 					       struct xfrm_usersa_info *p,
 					       struct nlattr **attrs,
@@ -579,8 +592,7 @@
 
 	xfrm_mark_get(attrs, &x->mark);
 
-	if (attrs[XFRMA_OUTPUT_MARK])
-		x->props.output_mark = nla_get_u32(attrs[XFRMA_OUTPUT_MARK]);
+	xfrm_smark_init(attrs, &x->props.smark);
 
 	err = __xfrm_init_state(x, false);
 	if (err)
@@ -795,6 +807,18 @@
 	return 0;
 }
 
+static int xfrm_smark_put(struct sk_buff *skb, struct xfrm_mark *m)
+{
+	int ret = 0;
+
+	if (m->v | m->m) {
+		ret = nla_put_u32(skb, XFRMA_SET_MARK, m->v);
+		if (!ret)
+			ret = nla_put_u32(skb, XFRMA_SET_MARK_MASK, m->m);
+	}
+	return ret;
+}
+
 /* Don't change this without updating xfrm_sa_len! */
 static int copy_to_user_state_extra(struct xfrm_state *x,
 				    struct xfrm_usersa_info *p,
@@ -858,6 +882,11 @@
 	ret = xfrm_mark_put(skb, &x->mark);
 	if (ret)
 		goto out;
+
+	ret = xfrm_smark_put(skb, &x->props.smark);
+	if (ret)
+		goto out;
+
 	if (x->replay_esn)
 		ret = nla_put(skb, XFRMA_REPLAY_ESN_VAL,
 			      xfrm_replay_state_esn_len(x->replay_esn),
@@ -867,11 +896,6 @@
 			      &x->replay);
 	if (ret)
 		goto out;
-	if (x->props.output_mark) {
-		ret = nla_put_u32(skb, XFRMA_OUTPUT_MARK, x->props.output_mark);
-		if (ret)
-			goto out;
-	}
 	if (x->security)
 		ret = copy_sec_ctx(x->security, skb);
 out:
@@ -2439,7 +2463,8 @@
 	[XFRMA_SA_EXTRA_FLAGS]	= { .type = NLA_U32 },
 	[XFRMA_PROTO]		= { .type = NLA_U8 },
 	[XFRMA_ADDRESS_FILTER]	= { .len = sizeof(struct xfrm_address_filter) },
-	[XFRMA_OUTPUT_MARK]	= { .type = NLA_U32 },
+	[XFRMA_SET_MARK]	= { .type = NLA_U32 },
+	[XFRMA_SET_MARK_MASK]	= { .type = NLA_U32 },
 };
 
 static const struct nla_policy xfrma_spd_policy[XFRMA_SPD_MAX+1] = {
@@ -2659,8 +2684,10 @@
 		l += nla_total_size(sizeof(*x->coaddr));
 	if (x->props.extra_flags)
 		l += nla_total_size(sizeof(x->props.extra_flags));
-	if (x->props.output_mark)
-		l += nla_total_size(sizeof(x->props.output_mark));
+	if (x->props.smark.v | x->props.smark.m) {
+		l += nla_total_size(sizeof(x->props.smark.v));
+		l += nla_total_size(sizeof(x->props.smark.m));
+	}
 
 	/* Must count x->lastused as it may become non-zero behind our back. */
 	l += nla_total_size_64bit(sizeof(u64));