udpencap: Remove Obsolete UDP_ENCAP_ESPINUDP_NON_IKE Support

The UDP_ENCAP_ESPINUDP_NON_IKE mode, introduced into the Linux kernel
in 2004 [2], has remained inactive and obsolete for an extended period.

This mode was originally defined in an early version of an IETF draft
[1] from 2001. By the time it was integrated into the kernel in 2004 [2],
it had already been replaced by UDP_ENCAP_ESPINUDP [3] in later
versions of draft-ietf-ipsec-udp-encaps, particularly in version 06.

Over time, UDP_ENCAP_ESPINUDP_NON_IKE has lost its relevance, with no
known use cases.

With this commit, we remove support for UDP_ENCAP_ESPINUDP_NON_IKE,
simplifying the codebase and eliminating unnecessary complexity.
Kernel will return an error -ENOPROTOOPT if the userspace tries to set
this option.

References:
[1] https://datatracker.ietf.org/doc/html/draft-ietf-ipsec-udp-encaps-00.txt

[2] Commit that added UDP_ENCAP_ESPINUDP_NON_IKE to the Linux historic
    repository.

    Author: Andreas Gruenbacher <agruen@suse.de>
    Date: Fri Apr 9 01:47:47 2004 -0700

   [IPSEC]: Support draft-ietf-ipsec-udp-encaps-00/01, some ipec impls need it.

[3] Commit that added UDP_ENCAP_ESPINUDP to the Linux historic
    repository.

    Author: Derek Atkins <derek@ihtfp.com>
    Date: Wed Apr 2 13:21:02 2003 -0800

    [IPSEC]: Implement UDP Encapsulation framework.

Signed-off-by: Antony Antony <antony.antony@secunet.com>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>

diff --git a/include/uapi/linux/udp.h b/include/uapi/linux/udp.h
index 4828794efcf865fc7a8e408000bff2176cf58f7c..1a0fe8b151fb33543429d1f59167a9021b458e20 100644 (file)
--- a/include/uapi/linux/udp.h
+++ b/include/uapi/linux/udp.h
@@ -36,7 +36,7 @@ struct udphdr {
 #define UDP_GRO                104     /* This socket can receive UDP GRO packets */
 
 /* UDP encapsulation types */
-#define UDP_ENCAP_ESPINUDP_NON_IKE     1 /* draft-ietf-ipsec-nat-t-ike-00/01 */
+#define UDP_ENCAP_ESPINUDP_NON_IKE     1 /* unused  draft-ietf-ipsec-nat-t-ike-00/01 */
 #define UDP_ENCAP_ESPINUDP     2 /* draft-ietf-ipsec-udp-encaps-06 */
 #define UDP_ENCAP_L2TPINUDP    3 /* rfc2661 */
 #define UDP_ENCAP_GTP0         4 /* GSM TS 09.60 */

diff --git a/net/ipv4/esp4.c b/net/ipv4/esp4.c
index 3d647c9a7a21e7301e1193f165599f19e8e0bc9d..7d38ddd64115768a82930b0230f2642dc02b4dfc 100644 (file)
--- a/net/ipv4/esp4.c
+++ b/net/ipv4/esp4.c
@@ -347,7 +347,6 @@ static struct ip_esp_hdr *esp_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);
@@ -362,12 +361,6 @@ static struct ip_esp_hdr *esp_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);
 }
 
@@ -423,7 +416,6 @@ static int esp_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 = esp_output_udp_encap(skb, encap_type, esp, sport, dport);
                break;
        case TCP_ENCAP_ESPINTCP:
@@ -775,7 +767,6 @@ int esp_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:
@@ -1179,9 +1170,6 @@ static int esp_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_INET_ESPINTCP
                case TCP_ENCAP_ESPINTCP:
                        /* only the length field, TCP encap is done by

diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c
index 7613daa339b0bcf456b7ce73c24939036e44c7ed..4ca781065a07af454c40036027b445b938061d80 100644 (file)
--- a/net/ipv4/udp.c
+++ b/net/ipv4/udp.c
@@ -2699,8 +2699,6 @@ int udp_lib_setsockopt(struct sock *sk, int level, int optname,
 #ifdef CONFIG_XFRM
                case UDP_ENCAP_ESPINUDP:
                        set_xfrm_gro_udp_encap_rcv(val, sk->sk_family, sk);
-                       fallthrough;
-               case UDP_ENCAP_ESPINUDP_NON_IKE:
 #if IS_ENABLED(CONFIG_IPV6)
                        if (sk->sk_family == AF_INET6)
                                WRITE_ONCE(up->encap_rcv,

diff --git a/net/ipv4/xfrm4_input.c b/net/ipv4/xfrm4_input.c
index dae35101d18959b73e60904f2225e59d1423455a..0918b0682174ce2e5b2cd60bfee20339ceebcb6d 100644 (file)
--- a/net/ipv4/xfrm4_input.c
+++ b/net/ipv4/xfrm4_input.c
@@ -113,19 +113,6 @@ static int __xfrm4_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,

diff --git a/net/ipv6/esp6.c b/net/ipv6/esp6.c
index fe8d53f5a5eecb6bdae87348b6b8f5fb27b23ac7..27df148530a6e2c63628500a74bb49abb5f0b329 100644 (file)
--- a/net/ipv6/esp6.c
+++ b/net/ipv6/esp6.c
@@ -383,7 +383,6 @@ 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);
@@ -398,12 +397,6 @@ 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);
 }
 
@@ -459,7 +452,6 @@ 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:
@@ -822,7 +814,6 @@ 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:
@@ -1232,9 +1223,6 @@ 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 a17d783dc7c0d7de6695e1ccec3a7b3a87f31e88..2c6aeb090b7ab6624edfa7038fb8660fb6a26e9c 100644 (file)
--- 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,