Remove DECnet support from kernel

DECnet is an obsolete network protocol that receives more attention
from kernel janitors than users. It belongs in computer protocol
history museum not in Linux kernel.

It has been "Orphaned" in kernel since 2010. The iproute2 support
for DECnet was dropped in 5.0 release. The documentation link on
Sourceforge says it is abandoned there as well.

Leave the UAPI alone to keep userspace programs compiling.
This means that there is still an empty neighbour table
for AF_DECNET.

The table of /proc/sys/net entries was updated to match
current directories and reformatted to be alphabetical.

Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
Acked-by: David Ahern <dsahern@kernel.org>
Acked-by: Nikolay Aleksandrov <razor@blackwall.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

3 files changed, 1 insertions, 222 deletions

diff --git a/include/uapi/linux/dn.h b/include/uapi/linux/dn.h
deleted file mode 100644
index 36ca71bd8bbe..000000000000
--- a/include/uapi/linux/dn.h
+++ /dev/null
@@ -1,149 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
-#ifndef _LINUX_DN_H
-#define _LINUX_DN_H
-
-#include <linux/ioctl.h>
-#include <linux/types.h>
-#include <linux/if_ether.h>
-
-/*
-
-	DECnet Data Structures and Constants
-
-*/
-
-/* 
- * DNPROTO_NSP can't be the same as SOL_SOCKET, 
- * so increment each by one (compared to ULTRIX)
- */
-#define DNPROTO_NSP     2                       /* NSP protocol number       */
-#define DNPROTO_ROU     3                       /* Routing protocol number   */
-#define DNPROTO_NML     4                       /* Net mgt protocol number   */
-#define DNPROTO_EVL     5                       /* Evl protocol number (usr) */
-#define DNPROTO_EVR     6                       /* Evl protocol number (evl) */
-#define DNPROTO_NSPT    7                       /* NSP trace protocol number */
-
-
-#define DN_ADDL		2
-#define DN_MAXADDL	2 /* ULTRIX headers have 20 here, but pathworks has 2 */
-#define DN_MAXOPTL	16
-#define DN_MAXOBJL	16
-#define DN_MAXACCL	40
-#define DN_MAXALIASL	128
-#define DN_MAXNODEL	256
-#define DNBUFSIZE	65023
-
-/* 
- * SET/GET Socket options  - must match the DSO_ numbers below
- */
-#define SO_CONDATA      1
-#define SO_CONACCESS    2
-#define SO_PROXYUSR     3
-#define SO_LINKINFO     7
-
-#define DSO_CONDATA     1        /* Set/Get connect data                */
-#define DSO_DISDATA     10       /* Set/Get disconnect data             */
-#define DSO_CONACCESS   2        /* Set/Get connect access data         */
-#define DSO_ACCEPTMODE  4        /* Set/Get accept mode                 */
-#define DSO_CONACCEPT   5        /* Accept deferred connection          */
-#define DSO_CONREJECT   6        /* Reject deferred connection          */
-#define DSO_LINKINFO    7        /* Set/Get link information            */
-#define DSO_STREAM      8        /* Set socket type to stream           */
-#define DSO_SEQPACKET   9        /* Set socket type to sequenced packet */
-#define DSO_MAXWINDOW   11       /* Maximum window size allowed         */
-#define DSO_NODELAY	12       /* Turn off nagle                      */
-#define DSO_CORK        13       /* Wait for more data!                 */
-#define DSO_SERVICES	14       /* NSP Services field                  */
-#define DSO_INFO	15       /* NSP Info field                      */
-#define DSO_MAX         15       /* Maximum option number               */
-
-
-/* LINK States */
-#define LL_INACTIVE	0
-#define LL_CONNECTING	1
-#define LL_RUNNING	2
-#define LL_DISCONNECTING 3
-
-#define ACC_IMMED 0
-#define ACC_DEFER 1
-
-#define SDF_WILD        1                  /* Wild card object          */
-#define SDF_PROXY       2                  /* Addr eligible for proxy   */
-#define SDF_UICPROXY    4                  /* Use uic-based proxy       */
-
-/* Structures */
-
-
-struct dn_naddr {
-	__le16		a_len;
-	__u8 a_addr[DN_MAXADDL]; /* Two bytes little endian */
-};
-
-struct sockaddr_dn {
-	__u16		sdn_family;
-	__u8		sdn_flags;
-	__u8		sdn_objnum;
-	__le16		sdn_objnamel;
-	__u8		sdn_objname[DN_MAXOBJL];
-	struct   dn_naddr	sdn_add;
-};
-#define sdn_nodeaddrl   sdn_add.a_len   /* Node address length  */
-#define sdn_nodeaddr    sdn_add.a_addr  /* Node address         */
-
-
-
-/*
- * DECnet set/get DSO_CONDATA, DSO_DISDATA (optional data) structure
- */
-struct optdata_dn {
-        __le16  opt_status;     /* Extended status return */
-#define opt_sts opt_status
-        __le16  opt_optl;       /* Length of user data    */
-        __u8   opt_data[16];   /* User data              */
-};
-
-struct accessdata_dn {
-	__u8		acc_accl;
-	__u8		acc_acc[DN_MAXACCL];
-	__u8 		acc_passl;
-	__u8		acc_pass[DN_MAXACCL];
-	__u8 		acc_userl;
-	__u8		acc_user[DN_MAXACCL];
-};
-
-/*
- * DECnet logical link information structure
- */
-struct linkinfo_dn {
-        __u16  idn_segsize;    /* Segment size for link */
-        __u8   idn_linkstate;  /* Logical link state    */
-};
-
-/*
- * Ethernet address format (for DECnet)
- */
-union etheraddress {
-        __u8 dne_addr[ETH_ALEN];      /* Full ethernet address */
-  struct {
-                __u8 dne_hiord[4];    /* DECnet HIORD prefix   */
-                __u8 dne_nodeaddr[2]; /* DECnet node address   */
-  } dne_remote;
-};
-
-
-/*
- * DECnet physical socket address format
- */
-struct dn_addr {
-        __le16 dna_family;      /* AF_DECnet               */
-        union etheraddress dna_netaddr; /* DECnet ethernet address */
-};
-
-#define DECNET_IOCTL_BASE 0x89 /* PROTOPRIVATE range */
-
-#define SIOCSNETADDR  _IOW(DECNET_IOCTL_BASE, 0xe0, struct dn_naddr)
-#define SIOCGNETADDR  _IOR(DECNET_IOCTL_BASE, 0xe1, struct dn_naddr)
-#define OSIOCSNETADDR _IOW(DECNET_IOCTL_BASE, 0xe0, int)
-#define OSIOCGNETADDR _IOR(DECNET_IOCTL_BASE, 0xe1, int)
-
-#endif /* _LINUX_DN_H */
diff --git a/include/uapi/linux/netfilter_decnet.h b/include/uapi/linux/netfilter_decnet.h
deleted file mode 100644
index 3c77f54560f2..000000000000
--- a/include/uapi/linux/netfilter_decnet.h
+++ /dev/null
@@ -1,72 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
-#ifndef __LINUX_DECNET_NETFILTER_H
-#define __LINUX_DECNET_NETFILTER_H
-
-/* DECnet-specific defines for netfilter. 
- * This file (C) Steve Whitehouse 1999 derived from the
- * ipv4 netfilter header file which is
- * (C)1998 Rusty Russell -- This code is GPL.
- */
-
-#include <linux/netfilter.h>
-
-/* only for userspace compatibility */
-#ifndef __KERNEL__
-
-#include <limits.h> /* for INT_MIN, INT_MAX */
-
-/* kernel define is in netfilter_defs.h */
-#define NF_DN_NUMHOOKS		7
-#endif /* ! __KERNEL__ */
-
-/* DECnet Hooks */
-/* After promisc drops, checksum checks. */
-#define NF_DN_PRE_ROUTING	0
-/* If the packet is destined for this box. */
-#define NF_DN_LOCAL_IN		1
-/* If the packet is destined for another interface. */
-#define NF_DN_FORWARD		2
-/* Packets coming from a local process. */
-#define NF_DN_LOCAL_OUT		3
-/* Packets about to hit the wire. */
-#define NF_DN_POST_ROUTING	4
-/* Input Hello Packets */
-#define NF_DN_HELLO		5
-/* Input Routing Packets */
-#define NF_DN_ROUTE		6
-
-enum nf_dn_hook_priorities {
-	NF_DN_PRI_FIRST = INT_MIN,
-	NF_DN_PRI_CONNTRACK = -200,
-	NF_DN_PRI_MANGLE = -150,
-	NF_DN_PRI_NAT_DST = -100,
-	NF_DN_PRI_FILTER = 0,
-	NF_DN_PRI_NAT_SRC = 100,
-	NF_DN_PRI_DNRTMSG = 200,
-	NF_DN_PRI_LAST = INT_MAX,
-};
-
-struct nf_dn_rtmsg {
-	int nfdn_ifindex;
-};
-
-#define NFDN_RTMSG(r) ((unsigned char *)(r) + NLMSG_ALIGN(sizeof(struct nf_dn_rtmsg)))
-
-#ifndef __KERNEL__
-/* backwards compatibility for userspace */
-#define DNRMG_L1_GROUP 0x01
-#define DNRMG_L2_GROUP 0x02
-#endif
-
-enum {
-	DNRNG_NLGRP_NONE,
-#define DNRNG_NLGRP_NONE	DNRNG_NLGRP_NONE
-	DNRNG_NLGRP_L1,
-#define DNRNG_NLGRP_L1		DNRNG_NLGRP_L1
-	DNRNG_NLGRP_L2,
-#define DNRNG_NLGRP_L2		DNRNG_NLGRP_L2
-	__DNRNG_NLGRP_MAX
-};
-#define DNRNG_NLGRP_MAX	(__DNRNG_NLGRP_MAX - 1)
-
-#endif /*__LINUX_DECNET_NETFILTER_H*/
diff --git a/include/uapi/linux/netlink.h b/include/uapi/linux/netlink.h
index 855dffb4c1c3..1e543cf0568c 100644
--- a/include/uapi/linux/netlink.h
+++ b/include/uapi/linux/netlink.h
@@ -20,7 +20,7 @@
 #define NETLINK_CONNECTOR	11
 #define NETLINK_NETFILTER	12	/* netfilter subsystem */
 #define NETLINK_IP6_FW		13
-#define NETLINK_DNRTMSG		14	/* DECnet routing messages */
+#define NETLINK_DNRTMSG		14	/* DECnet routing messages (obsolete) */
 #define NETLINK_KOBJECT_UEVENT	15	/* Kernel messages to userspace */
 #define NETLINK_GENERIC		16
 /* leave room for NETLINK_DM (DM Events) */