Merge tag 'ipsec-next-2024-05-03' of git://git.kernel.org/pub/scm/linux/kernel/git/klassert/ipsec-next

Steffen Klassert says:

====================
pull request (net-next): ipsec-next 2024-05-03

1) Remove Obsolete UDP_ENCAP_ESPINUDP_NON_IKE Support.
   This was defined by an early version of an IETF draft
   that did not make it to a standard.

2) Introduce direction attribute for xfrm states.
   xfrm states have a direction, a stsate can be used
   either for input or output packet processing.
   Add a direction to xfrm states to make it clear
   for what a xfrm state is used.

* tag 'ipsec-next-2024-05-03' of git://git.kernel.org/pub/scm/linux/kernel/git/klassert/ipsec-next:
  xfrm: Restrict SA direction attribute to specific netlink message types
  xfrm: Add dir validation to "in" data path lookup
  xfrm: Add dir validation to "out" data path lookup
  xfrm: Add Direction to the SA in or out
  udpencap: Remove Obsolete UDP_ENCAP_ESPINUDP_NON_IKE Support
====================

Link: https://lore.kernel.org/r/20240503082732.2835810-1-steffen.klassert@secunet.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

8 files changed, 196 insertions, 9 deletions

diff --git a/net/xfrm/xfrm_compat.c b/net/xfrm/xfrm_compat.c
index 655fe4ff8621..703d4172c7d7 100644
--- a/net/xfrm/xfrm_compat.c
+++ b/net/xfrm/xfrm_compat.c
@@ -98,6 +98,7 @@ static const int compat_msg_min[XFRM_NR_MSGTYPES] = {
 };
 
 static const struct nla_policy compat_policy[XFRMA_MAX+1] = {
+	[XFRMA_UNSPEC]          = { .strict_start_type = XFRMA_SA_DIR },
 	[XFRMA_SA]		= { .len = XMSGSIZE(compat_xfrm_usersa_info)},
 	[XFRMA_POLICY]		= { .len = XMSGSIZE(compat_xfrm_userpolicy_info)},
 	[XFRMA_LASTUSED]	= { .type = NLA_U64},
@@ -129,6 +130,7 @@ static const struct nla_policy compat_policy[XFRMA_MAX+1] = {
 	[XFRMA_SET_MARK_MASK]	= { .type = NLA_U32 },
 	[XFRMA_IF_ID]		= { .type = NLA_U32 },
 	[XFRMA_MTIMER_THRESH]	= { .type = NLA_U32 },
+	[XFRMA_SA_DIR]          = NLA_POLICY_RANGE(NLA_U8, XFRM_SA_DIR_IN, XFRM_SA_DIR_OUT),
 };
 
 static struct nlmsghdr *xfrm_nlmsg_put_compat(struct sk_buff *skb,
@@ -277,9 +279,10 @@ static int xfrm_xlate64_attr(struct sk_buff *dst, const struct nlattr *src)
 	case XFRMA_SET_MARK_MASK:
 	case XFRMA_IF_ID:
 	case XFRMA_MTIMER_THRESH:
+	case XFRMA_SA_DIR:
 		return xfrm_nla_cpy(dst, src, nla_len(src));
 	default:
-		BUILD_BUG_ON(XFRMA_MAX != XFRMA_MTIMER_THRESH);
+		BUILD_BUG_ON(XFRMA_MAX != XFRMA_SA_DIR);
 		pr_warn_once("unsupported nla_type %d\n", src->nla_type);
 		return -EOPNOTSUPP;
 	}
@@ -434,7 +437,7 @@ static int xfrm_xlate32_attr(void *dst, const struct nlattr *nla,
 	int err;
 
 	if (type > XFRMA_MAX) {
-		BUILD_BUG_ON(XFRMA_MAX != XFRMA_MTIMER_THRESH);
+		BUILD_BUG_ON(XFRMA_MAX != XFRMA_SA_DIR);
 		NL_SET_ERR_MSG(extack, "Bad attribute");
 		return -EOPNOTSUPP;
 	}
diff --git a/net/xfrm/xfrm_device.c b/net/xfrm/xfrm_device.c
index 6346690d5c69..2455a76a1cff 100644
--- a/net/xfrm/xfrm_device.c
+++ b/net/xfrm/xfrm_device.c
@@ -253,6 +253,12 @@ int xfrm_dev_state_add(struct net *net, struct xfrm_state *x,
 		return -EINVAL;
 	}
 
+	if ((xuo->flags & XFRM_OFFLOAD_INBOUND && x->dir == XFRM_SA_DIR_OUT) ||
+	    (!(xuo->flags & XFRM_OFFLOAD_INBOUND) && x->dir == XFRM_SA_DIR_IN)) {
+		NL_SET_ERR_MSG(extack, "Mismatched SA and offload direction");
+		return -EINVAL;
+	}
+
 	is_packet_offload = xuo->flags & XFRM_OFFLOAD_PACKET;
 
 	/* We don't yet support UDP encapsulation and TFC padding. */
diff --git a/net/xfrm/xfrm_input.c b/net/xfrm/xfrm_input.c
index 161f535c8b94..71b42de6e3c9 100644
--- a/net/xfrm/xfrm_input.c
+++ b/net/xfrm/xfrm_input.c
@@ -466,6 +466,11 @@ int xfrm_input(struct sk_buff *skb, int nexthdr, __be32 spi, int encap_type)
 	if (encap_type < 0 || (xo && xo->flags & XFRM_GRO)) {
 		x = xfrm_input_state(skb);
 
+		if (unlikely(x->dir && x->dir != XFRM_SA_DIR_IN)) {
+			XFRM_INC_STATS(net, LINUX_MIB_XFRMINSTATEDIRERROR);
+			goto drop;
+		}
+
 		if (unlikely(x->km.state != XFRM_STATE_VALID)) {
 			if (x->km.state == XFRM_STATE_ACQ)
 				XFRM_INC_STATS(net, LINUX_MIB_XFRMACQUIREERROR);
@@ -571,6 +576,12 @@ int xfrm_input(struct sk_buff *skb, int nexthdr, __be32 spi, int encap_type)
 			goto drop;
 		}
 
+		if (unlikely(x->dir && x->dir != XFRM_SA_DIR_IN)) {
+			XFRM_INC_STATS(net, LINUX_MIB_XFRMINSTATEDIRERROR);
+			xfrm_state_put(x);
+			goto drop;
+		}
+
 		skb->mark = xfrm_smark_get(skb->mark, x);
 
 		sp->xvec[sp->len++] = x;
diff --git a/net/xfrm/xfrm_policy.c b/net/xfrm/xfrm_policy.c
index 1a41650d9d7b..089b6c0e278b 100644
--- a/net/xfrm/xfrm_policy.c
+++ b/net/xfrm/xfrm_policy.c
@@ -2489,6 +2489,12 @@ xfrm_tmpl_resolve_one(struct xfrm_policy *policy, const struct flowi *fl,
 
 		x = xfrm_state_find(remote, local, fl, tmpl, policy, &error,
 				    family, policy->if_id);
+		if (x && x->dir && x->dir != XFRM_SA_DIR_OUT) {
+			XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTSTATEDIRERROR);
+			xfrm_state_put(x);
+			error = -EINVAL;
+			goto fail;
+		}
 
 		if (x && x->km.state == XFRM_STATE_VALID) {
 			xfrm[nx++] = x;
diff --git a/net/xfrm/xfrm_proc.c b/net/xfrm/xfrm_proc.c
index 5f9bf8e5c933..eeb984be03a7 100644
--- a/net/xfrm/xfrm_proc.c
+++ b/net/xfrm/xfrm_proc.c
@@ -41,6 +41,8 @@ static const struct snmp_mib xfrm_mib_list[] = {
 	SNMP_MIB_ITEM("XfrmFwdHdrError", LINUX_MIB_XFRMFWDHDRERROR),
 	SNMP_MIB_ITEM("XfrmOutStateInvalid", LINUX_MIB_XFRMOUTSTATEINVALID),
 	SNMP_MIB_ITEM("XfrmAcquireError", LINUX_MIB_XFRMACQUIREERROR),
+	SNMP_MIB_ITEM("XfrmOutStateDirError", LINUX_MIB_XFRMOUTSTATEDIRERROR),
+	SNMP_MIB_ITEM("XfrmInStateDirError", LINUX_MIB_XFRMINSTATEDIRERROR),
 	SNMP_MIB_SENTINEL
 };
 
diff --git a/net/xfrm/xfrm_replay.c b/net/xfrm/xfrm_replay.c
index ce56d659c55a..bc56c6305725 100644
--- a/net/xfrm/xfrm_replay.c
+++ b/net/xfrm/xfrm_replay.c
@@ -778,7 +778,8 @@ int xfrm_init_replay(struct xfrm_state *x, struct netlink_ext_ack *extack)
 		}
 
 		if (x->props.flags & XFRM_STATE_ESN) {
-			if (replay_esn->replay_window == 0) {
+			if (replay_esn->replay_window == 0 &&
+			    (!x->dir || x->dir == XFRM_SA_DIR_IN)) {
 				NL_SET_ERR_MSG(extack, "ESN replay window must be > 0");
 				return -EINVAL;
 			}
diff --git a/net/xfrm/xfrm_state.c b/net/xfrm/xfrm_state.c
index 0c306473a79d..649bb739df0d 100644
--- a/net/xfrm/xfrm_state.c
+++ b/net/xfrm/xfrm_state.c
@@ -1292,6 +1292,7 @@ found:
 		if (km_query(x, tmpl, pol) == 0) {
 			spin_lock_bh(&net->xfrm.xfrm_state_lock);
 			x->km.state = XFRM_STATE_ACQ;
+			x->dir = XFRM_SA_DIR_OUT;
 			list_add(&x->km.all, &net->xfrm.state_all);
 			XFRM_STATE_INSERT(bydst, &x->bydst,
 					  net->xfrm.state_bydst + h,
@@ -1744,6 +1745,7 @@ static struct xfrm_state *xfrm_state_clone(struct xfrm_state *orig,
 	x->lastused = orig->lastused;
 	x->new_mapping = 0;
 	x->new_mapping_sport = 0;
+	x->dir = orig->dir;
 
 	return x;
 
@@ -1864,8 +1866,14 @@ int xfrm_state_update(struct xfrm_state *x)
 	}
 
 	if (x1->km.state == XFRM_STATE_ACQ) {
+		if (x->dir && x1->dir != x->dir)
+			goto out;
+
 		__xfrm_state_insert(x);
 		x = NULL;
+	} else {
+		if (x1->dir != x->dir)
+			goto out;
 	}
 	err = 0;
 
diff --git a/net/xfrm/xfrm_user.c b/net/xfrm/xfrm_user.c
index 810b520493f3..e83c687bd64e 100644
--- a/net/xfrm/xfrm_user.c
+++ b/net/xfrm/xfrm_user.c
@@ -130,7 +130,7 @@ static inline int verify_sec_ctx_len(struct nlattr **attrs, struct netlink_ext_a
 }
 
 static inline int verify_replay(struct xfrm_usersa_info *p,
-				struct nlattr **attrs,
+				struct nlattr **attrs, u8 sa_dir,
 				struct netlink_ext_ack *extack)
 {
 	struct nlattr *rt = attrs[XFRMA_REPLAY_ESN_VAL];
@@ -168,6 +168,30 @@ static inline int verify_replay(struct xfrm_usersa_info *p,
 		return -EINVAL;
 	}
 
+	if (sa_dir == XFRM_SA_DIR_OUT)  {
+		if (rs->replay_window) {
+			NL_SET_ERR_MSG(extack, "Replay window should be 0 for output SA");
+			return -EINVAL;
+		}
+		if (rs->seq || rs->seq_hi) {
+			NL_SET_ERR_MSG(extack,
+				       "Replay seq and seq_hi should be 0 for output SA");
+			return -EINVAL;
+		}
+		if (rs->bmp_len) {
+			NL_SET_ERR_MSG(extack, "Replay bmp_len should 0 for output SA");
+			return -EINVAL;
+		}
+	}
+
+	if (sa_dir == XFRM_SA_DIR_IN)  {
+		if (rs->oseq || rs->oseq_hi) {
+			NL_SET_ERR_MSG(extack,
+				       "Replay oseq and oseq_hi should be 0 for input SA");
+			return -EINVAL;
+		}
+	}
+
 	return 0;
 }
 
@@ -176,6 +200,7 @@ static int verify_newsa_info(struct xfrm_usersa_info *p,
 			     struct netlink_ext_ack *extack)
 {
 	int err;
+	u8 sa_dir = attrs[XFRMA_SA_DIR] ? nla_get_u8(attrs[XFRMA_SA_DIR]) : 0;
 
 	err = -EINVAL;
 	switch (p->family) {
@@ -334,7 +359,7 @@ static int verify_newsa_info(struct xfrm_usersa_info *p,
 		goto out;
 	if ((err = verify_sec_ctx_len(attrs, extack)))
 		goto out;
-	if ((err = verify_replay(p, attrs, extack)))
+	if ((err = verify_replay(p, attrs, sa_dir, extack)))
 		goto out;
 
 	err = -EINVAL;
@@ -358,6 +383,77 @@ static int verify_newsa_info(struct xfrm_usersa_info *p,
 			err = -EINVAL;
 			goto out;
 		}
+
+		if (sa_dir == XFRM_SA_DIR_OUT) {
+			NL_SET_ERR_MSG(extack,
+				       "MTIMER_THRESH attribute should not be set on output SA");
+			err = -EINVAL;
+			goto out;
+		}
+	}
+
+	if (sa_dir == XFRM_SA_DIR_OUT) {
+		if (p->flags & XFRM_STATE_DECAP_DSCP) {
+			NL_SET_ERR_MSG(extack, "Flag DECAP_DSCP should not be set for output SA");
+			err = -EINVAL;
+			goto out;
+		}
+
+		if (p->flags & XFRM_STATE_ICMP) {
+			NL_SET_ERR_MSG(extack, "Flag ICMP should not be set for output SA");
+			err = -EINVAL;
+			goto out;
+		}
+
+		if (p->flags & XFRM_STATE_WILDRECV) {
+			NL_SET_ERR_MSG(extack, "Flag WILDRECV should not be set for output SA");
+			err = -EINVAL;
+			goto out;
+		}
+
+		if (p->replay_window) {
+			NL_SET_ERR_MSG(extack, "Replay window should be 0 for output SA");
+			err = -EINVAL;
+			goto out;
+		}
+
+		if (attrs[XFRMA_REPLAY_VAL]) {
+			struct xfrm_replay_state *replay;
+
+			replay = nla_data(attrs[XFRMA_REPLAY_VAL]);
+
+			if (replay->seq || replay->bitmap) {
+				NL_SET_ERR_MSG(extack,
+					       "Replay seq and bitmap should be 0 for output SA");
+				err = -EINVAL;
+				goto out;
+			}
+		}
+	}
+
+	if (sa_dir == XFRM_SA_DIR_IN) {
+		if (p->flags & XFRM_STATE_NOPMTUDISC) {
+			NL_SET_ERR_MSG(extack, "Flag NOPMTUDISC should not be set for input SA");
+			err = -EINVAL;
+			goto out;
+		}
+
+		if (attrs[XFRMA_SA_EXTRA_FLAGS]) {
+			u32 xflags = nla_get_u32(attrs[XFRMA_SA_EXTRA_FLAGS]);
+
+			if (xflags & XFRM_SA_XFLAG_DONT_ENCAP_DSCP) {
+				NL_SET_ERR_MSG(extack, "Flag DONT_ENCAP_DSCP should not be set for input SA");
+				err = -EINVAL;
+				goto out;
+			}
+
+			if (xflags & XFRM_SA_XFLAG_OSEQ_MAY_WRAP) {
+				NL_SET_ERR_MSG(extack, "Flag OSEQ_MAY_WRAP should not be set for input SA");
+				err = -EINVAL;
+				goto out;
+			}
+
+		}
 	}
 
 out:
@@ -734,6 +830,9 @@ static struct xfrm_state *xfrm_state_construct(struct net *net,
 	if (attrs[XFRMA_IF_ID])
 		x->if_id = nla_get_u32(attrs[XFRMA_IF_ID]);
 
+	if (attrs[XFRMA_SA_DIR])
+		x->dir = nla_get_u8(attrs[XFRMA_SA_DIR]);
+
 	err = __xfrm_init_state(x, false, attrs[XFRMA_OFFLOAD_DEV], extack);
 	if (err)
 		goto error;
@@ -1182,8 +1281,13 @@ static int copy_to_user_state_extra(struct xfrm_state *x,
 		if (ret)
 			goto out;
 	}
-	if (x->mapping_maxage)
+	if (x->mapping_maxage) {
 		ret = nla_put_u32(skb, XFRMA_MTIMER_THRESH, x->mapping_maxage);
+		if (ret)
+			goto out;
+	}
+	if (x->dir)
+		ret = nla_put_u8(skb, XFRMA_SA_DIR, x->dir);
 out:
 	return ret;
 }
@@ -1618,6 +1722,9 @@ static int xfrm_alloc_userspi(struct sk_buff *skb, struct nlmsghdr *nlh,
 	if (err)
 		goto out;
 
+	if (attrs[XFRMA_SA_DIR])
+		x->dir = nla_get_u8(attrs[XFRMA_SA_DIR]);
+
 	resp_skb = xfrm_state_netlink(skb, x, nlh->nlmsg_seq);
 	if (IS_ERR(resp_skb)) {
 		err = PTR_ERR(resp_skb);
@@ -2402,7 +2509,8 @@ static inline unsigned int xfrm_aevent_msgsize(struct xfrm_state *x)
 	       + nla_total_size_64bit(sizeof(struct xfrm_lifetime_cur))
 	       + nla_total_size(sizeof(struct xfrm_mark))
 	       + nla_total_size(4) /* XFRM_AE_RTHR */
-	       + nla_total_size(4); /* XFRM_AE_ETHR */
+	       + nla_total_size(4) /* XFRM_AE_ETHR */
+	       + nla_total_size(sizeof(x->dir)); /* XFRMA_SA_DIR */
 }
 
 static int build_aevent(struct sk_buff *skb, struct xfrm_state *x, const struct km_event *c)
@@ -2459,6 +2567,12 @@ static int build_aevent(struct sk_buff *skb, struct xfrm_state *x, const struct
 	if (err)
 		goto out_cancel;
 
+	if (x->dir) {
+		err = nla_put_u8(skb, XFRMA_SA_DIR, x->dir);
+		if (err)
+			goto out_cancel;
+	}
+
 	nlmsg_end(skb, nlh);
 	return 0;
 
@@ -3018,6 +3132,7 @@ EXPORT_SYMBOL_GPL(xfrm_msg_min);
 #undef XMSGSIZE
 
 const struct nla_policy xfrma_policy[XFRMA_MAX+1] = {
+	[XFRMA_UNSPEC]		= { .strict_start_type = XFRMA_SA_DIR },
 	[XFRMA_SA]		= { .len = sizeof(struct xfrm_usersa_info)},
 	[XFRMA_POLICY]		= { .len = sizeof(struct xfrm_userpolicy_info)},
 	[XFRMA_LASTUSED]	= { .type = NLA_U64},
@@ -3049,6 +3164,7 @@ const struct nla_policy xfrma_policy[XFRMA_MAX+1] = {
 	[XFRMA_SET_MARK_MASK]	= { .type = NLA_U32 },
 	[XFRMA_IF_ID]		= { .type = NLA_U32 },
 	[XFRMA_MTIMER_THRESH]   = { .type = NLA_U32 },
+	[XFRMA_SA_DIR]          = NLA_POLICY_RANGE(NLA_U8, XFRM_SA_DIR_IN, XFRM_SA_DIR_OUT),
 };
 EXPORT_SYMBOL_GPL(xfrma_policy);
 
@@ -3097,6 +3213,24 @@ static const struct xfrm_link {
 	[XFRM_MSG_GETDEFAULT  - XFRM_MSG_BASE] = { .doit = xfrm_get_default   },
 };
 
+static int xfrm_reject_unused_attr(int type, struct nlattr **attrs,
+				   struct netlink_ext_ack *extack)
+{
+	if (attrs[XFRMA_SA_DIR]) {
+		switch (type) {
+		case XFRM_MSG_NEWSA:
+		case XFRM_MSG_UPDSA:
+		case XFRM_MSG_ALLOCSPI:
+			break;
+		default:
+			NL_SET_ERR_MSG(extack, "Invalid attribute SA_DIR");
+			return -EINVAL;
+		}
+	}
+
+	return 0;
+}
+
 static int xfrm_user_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh,
 			     struct netlink_ext_ack *extack)
 {
@@ -3156,6 +3290,12 @@ static int xfrm_user_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh,
 	if (err < 0)
 		goto err;
 
+	if (!link->nla_pol || link->nla_pol == xfrma_policy) {
+		err = xfrm_reject_unused_attr((type + XFRM_MSG_BASE), attrs, extack);
+		if (err < 0)
+			goto err;
+	}
+
 	if (link->doit == NULL) {
 		err = -EINVAL;
 		goto err;
@@ -3189,8 +3329,9 @@ static void xfrm_netlink_rcv(struct sk_buff *skb)
 
 static inline unsigned int xfrm_expire_msgsize(void)
 {
-	return NLMSG_ALIGN(sizeof(struct xfrm_user_expire))
-	       + nla_total_size(sizeof(struct xfrm_mark));
+	return NLMSG_ALIGN(sizeof(struct xfrm_user_expire)) +
+	       nla_total_size(sizeof(struct xfrm_mark)) +
+	       nla_total_size(sizeof_field(struct xfrm_state, dir));
 }
 
 static int build_expire(struct sk_buff *skb, struct xfrm_state *x, const struct km_event *c)
@@ -3217,6 +3358,12 @@ static int build_expire(struct sk_buff *skb, struct xfrm_state *x, const struct
 	if (err)
 		return err;
 
+	if (x->dir) {
+		err = nla_put_u8(skb, XFRMA_SA_DIR, x->dir);
+		if (err)
+			return err;
+	}
+
 	nlmsg_end(skb, nlh);
 	return 0;
 }
@@ -3324,6 +3471,9 @@ static inline unsigned int xfrm_sa_len(struct xfrm_state *x)
 	if (x->mapping_maxage)
 		l += nla_total_size(sizeof(x->mapping_maxage));
 
+	if (x->dir)
+		l += nla_total_size(sizeof(x->dir));
+
 	return l;
 }