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>

2 files changed, 7 insertions, 25 deletions

diff --git a/net/ipv6/esp6.c b/net/ipv6/esp6.c
index 6bc0a84c8d05..34a9a5b9ed00 100644
--- a/net/ipv6/esp6.c
+++ b/net/ipv6/esp6.c
@@ -384,7 +384,6 @@ static struct ip_esp_hdr *esp6_output_udp_encap(struct sk_buff *skb,
 					       __be16 dport)
 {
 	struct udphdr *uh;
-	__be32 *udpdata32;
 	unsigned int len;
 
 	len = skb->len + esp->tailen - skb_transport_offset(skb);
@@ -399,12 +398,6 @@ static struct ip_esp_hdr *esp6_output_udp_encap(struct sk_buff *skb,
 
 	*skb_mac_header(skb) = IPPROTO_UDP;
 
-	if (encap_type == UDP_ENCAP_ESPINUDP_NON_IKE) {
-		udpdata32 = (__be32 *)(uh + 1);
-		udpdata32[0] = udpdata32[1] = 0;
-		return (struct ip_esp_hdr *)(udpdata32 + 2);
-	}
-
 	return (struct ip_esp_hdr *)(uh + 1);
 }
 
@@ -460,7 +453,6 @@ static int esp6_output_encap(struct xfrm_state *x, struct sk_buff *skb,
 	switch (encap_type) {
 	default:
 	case UDP_ENCAP_ESPINUDP:
-	case UDP_ENCAP_ESPINUDP_NON_IKE:
 		esph = esp6_output_udp_encap(skb, encap_type, esp, sport, dport);
 		break;
 	case TCP_ENCAP_ESPINTCP:
@@ -823,7 +815,6 @@ int esp6_input_done2(struct sk_buff *skb, int err)
 			source = th->source;
 			break;
 		case UDP_ENCAP_ESPINUDP:
-		case UDP_ENCAP_ESPINUDP_NON_IKE:
 			source = uh->source;
 			break;
 		default:
@@ -1233,9 +1224,6 @@ static int esp6_init_state(struct xfrm_state *x, struct netlink_ext_ack *extack)
 		case UDP_ENCAP_ESPINUDP:
 			x->props.header_len += sizeof(struct udphdr);
 			break;
-		case UDP_ENCAP_ESPINUDP_NON_IKE:
-			x->props.header_len += sizeof(struct udphdr) + 2 * sizeof(u32);
-			break;
 #ifdef CONFIG_INET6_ESPINTCP
 		case TCP_ENCAP_ESPINTCP:
 			/* only the length field, TCP encap is done by
diff --git a/net/ipv6/xfrm6_input.c b/net/ipv6/xfrm6_input.c
index a17d783dc7c0..d5bac0d76b6e 100644
--- a/net/ipv6/xfrm6_input.c
+++ b/net/ipv6/xfrm6_input.c
@@ -109,19 +109,6 @@ static int __xfrm6_udp_encap_rcv(struct sock *sk, struct sk_buff *skb, bool pull
 			/* Must be an IKE packet.. pass it through */
 			return 1;
 		break;
-	case UDP_ENCAP_ESPINUDP_NON_IKE:
-		/* Check if this is a keepalive packet.  If so, eat it. */
-		if (len == 1 && udpdata[0] == 0xff) {
-			return -EINVAL;
-		} else if (len > 2 * sizeof(u32) + sizeof(struct ip_esp_hdr) &&
-			   udpdata32[0] == 0 && udpdata32[1] == 0) {
-
-			/* ESP Packet with Non-IKE marker */
-			len = sizeof(struct udphdr) + 2 * sizeof(u32);
-		} else
-			/* Must be an IKE packet.. pass it through */
-			return 1;
-		break;
 	}
 
 	/* At this point we are sure that this is an ESPinUDP packet,
@@ -279,6 +266,13 @@ int xfrm6_input_addr(struct sk_buff *skb, xfrm_address_t *daddr,
 		if (!x)
 			continue;
 
+		if (unlikely(x->dir && x->dir != XFRM_SA_DIR_IN)) {
+			XFRM_INC_STATS(net, LINUX_MIB_XFRMINSTATEDIRERROR);
+			xfrm_state_put(x);
+			x = NULL;
+			continue;
+		}
+
 		spin_lock(&x->lock);
 
 		if ((!i || (x->props.flags & XFRM_STATE_WILDRECV)) &&