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>

Documentation/admin-guide/kernel-parameters.txt

@@ -966,10 +966,6 @@
 
 	debugpat	[X86] Enable PAT debugging
 
-	decnet.addr=	[HW,NET]
-			Format: <area>[,<node>]
-			See also Documentation/networking/decnet.rst.
-
 	default_hugepagesz=
 			[HW] The size of the default HugeTLB page. This is
 			the size represented by the legacy /proc/ hugepages

Documentation/admin-guide/sysctl/net.rst

@@ -34,13 +34,14 @@ Table : Subdirectories in /proc/sys/net
  ========= =================== = ========== ==================
  Directory Content               Directory  Content
  ========= =================== = ========== ==================
- core      General parameter     appletalk  Appletalk protocol
- unix      Unix domain sockets   netrom     NET/ROM
- 802       E802 protocol         ax25       AX25
- ethernet  Ethernet protocol     rose       X.25 PLP layer
+ 802       E802 protocol         mptcp     Multipath TCP
+ appletalk Appletalk protocol    netfilter Network Filter
+ ax25      AX25                  netrom     NET/ROM
+ bridge    Bridging              rose      X.25 PLP layer
+ core      General parameter     tipc      TIPC
+ ethernet  Ethernet protocol     unix      Unix domain sockets
  ipv4      IP version 4          x25       X.25 protocol
- bridge    Bridging              decnet     DEC net
- ipv6      IP version 6          tipc       TIPC
+ ipv6      IP version 6
  ========= =================== = ========== ==================
 
 1. /proc/sys/net/core - Network core options

Documentation/networking/index.rst

@@ -47,7 +47,6 @@ Contents:
    cdc_mbim
    dccp
    dctcp
-   decnet
    dns_resolver
    driver
    eql

Documentation/userspace-api/ioctl/ioctl-number.rst

@@ -308,7 +308,6 @@ Code  Seq#    Include File                                           Comments
 0x89  00-06  arch/x86/include/asm/sockios.h
 0x89  0B-DF  linux/sockios.h
 0x89  E0-EF  linux/sockios.h                                         SIOCPROTOPRIVATE range
-0x89  E0-EF  linux/dn.h                                              PROTOPRIVATE range
 0x89  F0-FF  linux/sockios.h                                         SIOCDEVPRIVATE range
 0x8B  all    linux/wireless.h
 0x8C  00-3F                                                          WiNRADiO driver

MAINTAINERS

@@ -5719,13 +5719,6 @@ F:	include/linux/tfrc.h
 F:	include/uapi/linux/dccp.h
 F:	net/dccp/
 
-DECnet NETWORK LAYER
-L:	linux-decnet-user@lists.sourceforge.net
-S:	Orphan
-W:	http://linux-decnet.sourceforge.net
-F:	Documentation/networking/decnet.rst
-F:	net/decnet/
-
 DECSTATION PLATFORM SUPPORT
 M:	"Maciej W. Rozycki" <macro@orcam.me.uk>
 L:	linux-mips@vger.kernel.org

arch/mips/configs/decstation_64_defconfig

@@ -53,8 +53,6 @@ CONFIG_IPV6_SUBTREES=y
 CONFIG_NETWORK_SECMARK=y
 CONFIG_IP_SCTP=m
 CONFIG_VLAN_8021Q=m
-CONFIG_DECNET=m
-CONFIG_DECNET_ROUTER=y
 # CONFIG_WIRELESS is not set
 # CONFIG_UEVENT_HELPER is not set
 # CONFIG_FW_LOADER is not set

arch/mips/configs/decstation_defconfig

@@ -49,8 +49,6 @@ CONFIG_IPV6_SUBTREES=y
 CONFIG_NETWORK_SECMARK=y
 CONFIG_IP_SCTP=m
 CONFIG_VLAN_8021Q=m
-CONFIG_DECNET=m
-CONFIG_DECNET_ROUTER=y
 # CONFIG_WIRELESS is not set
 # CONFIG_UEVENT_HELPER is not set
 # CONFIG_FW_LOADER is not set

arch/mips/configs/decstation_r4k_defconfig

@@ -48,8 +48,6 @@ CONFIG_IPV6_SUBTREES=y
 CONFIG_NETWORK_SECMARK=y
 CONFIG_IP_SCTP=m
 CONFIG_VLAN_8021Q=m
-CONFIG_DECNET=m
-CONFIG_DECNET_ROUTER=y
 # CONFIG_WIRELESS is not set
 # CONFIG_UEVENT_HELPER is not set
 # CONFIG_FW_LOADER is not set

arch/mips/configs/gpr_defconfig

@@ -69,7 +69,6 @@ CONFIG_IP_NF_RAW=m
 CONFIG_IP_NF_ARPTABLES=m
 CONFIG_IP_NF_ARPFILTER=m
 CONFIG_IP_NF_ARP_MANGLE=m
-CONFIG_DECNET_NF_GRABULATOR=m
 CONFIG_BRIDGE_NF_EBTABLES=m
 CONFIG_BRIDGE_EBT_BROUTE=m
 CONFIG_BRIDGE_EBT_T_FILTER=m
@@ -99,7 +98,6 @@ CONFIG_ATM_MPOA=m
 CONFIG_ATM_BR2684=m
 CONFIG_BRIDGE=m
 CONFIG_VLAN_8021Q=m
-CONFIG_DECNET=m
 CONFIG_LLC2=m
 CONFIG_ATALK=m
 CONFIG_DEV_APPLETALK=m

arch/mips/configs/mtx1_defconfig

@@ -116,7 +116,6 @@ CONFIG_IP6_NF_FILTER=m
 CONFIG_IP6_NF_TARGET_REJECT=m
 CONFIG_IP6_NF_MANGLE=m
 CONFIG_IP6_NF_RAW=m
-CONFIG_DECNET_NF_GRABULATOR=m
 CONFIG_BRIDGE_NF_EBTABLES=m
 CONFIG_BRIDGE_EBT_BROUTE=m
 CONFIG_BRIDGE_EBT_T_FILTER=m
@@ -146,7 +145,6 @@ CONFIG_ATM_MPOA=m
 CONFIG_ATM_BR2684=m
 CONFIG_BRIDGE=m
 CONFIG_VLAN_8021Q=m
-CONFIG_DECNET=m
 CONFIG_LLC2=m
 CONFIG_ATALK=m
 CONFIG_DEV_APPLETALK=m

arch/mips/configs/rm200_defconfig

@@ -116,7 +116,6 @@ CONFIG_IP6_NF_FILTER=m
 CONFIG_IP6_NF_TARGET_REJECT=m
 CONFIG_IP6_NF_MANGLE=m
 CONFIG_IP6_NF_RAW=m
-CONFIG_DECNET_NF_GRABULATOR=m
 CONFIG_BRIDGE_NF_EBTABLES=m
 CONFIG_BRIDGE_EBT_BROUTE=m
 CONFIG_BRIDGE_EBT_T_FILTER=m
@@ -137,7 +136,6 @@ CONFIG_BRIDGE_EBT_REDIRECT=m
 CONFIG_BRIDGE_EBT_SNAT=m
 CONFIG_BRIDGE_EBT_LOG=m
 CONFIG_BRIDGE=m
-CONFIG_DECNET=m
 CONFIG_NET_SCHED=y
 CONFIG_NET_SCH_CBQ=m
 CONFIG_NET_SCH_HTB=m

arch/powerpc/configs/ppc6xx_defconfig

@@ -243,8 +243,6 @@ CONFIG_ATM_LANE=m
 CONFIG_ATM_BR2684=m
 CONFIG_BRIDGE=m
 CONFIG_VLAN_8021Q=m
-CONFIG_DECNET=m
-CONFIG_DECNET_ROUTER=y
 CONFIG_ATALK=m
 CONFIG_DEV_APPLETALK=m
 CONFIG_IPDDP=m

include/linux/netdevice.h

@@ -1837,7 +1837,6 @@ enum netdev_ml_priv_type {
  *	@tipc_ptr:	TIPC specific data
  *	@atalk_ptr:	AppleTalk link
  *	@ip_ptr:	IPv4 specific data
- *	@dn_ptr:	DECnet specific data
  *	@ip6_ptr:	IPv6 specific data
  *	@ax25_ptr:	AX.25 specific data
  *	@ieee80211_ptr:	IEEE 802.11 specific data, assign before registering
@@ -2133,9 +2132,6 @@ struct net_device {
 #if IS_ENABLED(CONFIG_ATALK)
 	void 			*atalk_ptr;
 #endif
-#if IS_ENABLED(CONFIG_DECNET)
-	struct dn_dev __rcu     *dn_ptr;
-#endif
 #if IS_ENABLED(CONFIG_AX25)
 	void			*ax25_ptr;
 #endif

include/linux/netfilter.h

@@ -243,11 +243,6 @@ static inline int nf_hook(u_int8_t pf, unsigned int hook, struct net *net,
 		hook_head = rcu_dereference(net->nf.hooks_bridge[hook]);
 #endif
 		break;
-#if IS_ENABLED(CONFIG_DECNET)
-	case NFPROTO_DECNET:
-		hook_head = rcu_dereference(net->nf.hooks_decnet[hook]);
-		break;
-#endif
 	default:
 		WARN_ON_ONCE(1);
 		break;

include/linux/netfilter_defs.h

@@ -7,14 +7,6 @@
 /* in/out/forward only */
 #define NF_ARP_NUMHOOKS 3
 
-/* max hook is NF_DN_ROUTE (6), also see uapi/linux/netfilter_decnet.h */
-#define NF_DN_NUMHOOKS 7
-
-#if IS_ENABLED(CONFIG_DECNET)
-/* Largest hook number + 1, see uapi/linux/netfilter_decnet.h */
-#define NF_MAX_HOOKS	NF_DN_NUMHOOKS
-#else
 #define NF_MAX_HOOKS	NF_INET_NUMHOOKS
-#endif
 
 #endif

include/net/dn.h

-/* SPDX-License-Identifier: GPL-2.0 */
-#ifndef _NET_DN_H
-#define _NET_DN_H
-
-#include <linux/dn.h>
-#include <net/sock.h>
-#include <net/flow.h>
-#include <asm/byteorder.h>
-#include <asm/unaligned.h>
-
-struct dn_scp                                   /* Session Control Port */
-{
-        unsigned char           state;
-#define DN_O     1                      /* Open                 */
-#define DN_CR    2                      /* Connect Receive      */
-#define DN_DR    3                      /* Disconnect Reject    */
-#define DN_DRC   4                      /* Discon. Rej. Complete*/
-#define DN_CC    5                      /* Connect Confirm      */
-#define DN_CI    6                      /* Connect Initiate     */
-#define DN_NR    7                      /* No resources         */
-#define DN_NC    8                      /* No communication     */
-#define DN_CD    9                      /* Connect Delivery     */
-#define DN_RJ    10                     /* Rejected             */
-#define DN_RUN   11                     /* Running              */
-#define DN_DI    12                     /* Disconnect Initiate  */
-#define DN_DIC   13                     /* Disconnect Complete  */
-#define DN_DN    14                     /* Disconnect Notificat */
-#define DN_CL    15                     /* Closed               */
-#define DN_CN    16                     /* Closed Notification  */
-
-        __le16          addrloc;
-        __le16          addrrem;
-        __u16          numdat;
-        __u16          numoth;
-        __u16          numoth_rcv;
-        __u16          numdat_rcv;
-        __u16          ackxmt_dat;
-        __u16          ackxmt_oth;
-        __u16          ackrcv_dat;
-        __u16          ackrcv_oth;
-        __u8           flowrem_sw;
-	__u8           flowloc_sw;
-#define DN_SEND         2
-#define DN_DONTSEND     1
-#define DN_NOCHANGE     0
-	__u16		flowrem_dat;
-	__u16		flowrem_oth;
-	__u16		flowloc_dat;
-	__u16		flowloc_oth;
-	__u8		services_rem;
-	__u8		services_loc;
-	__u8		info_rem;
-	__u8		info_loc;
-
-	__u16		segsize_rem;
-	__u16		segsize_loc;
-
-	__u8		nonagle;
-	__u8		multi_ireq;
-	__u8		accept_mode;
-	unsigned long		seg_total; /* Running total of current segment */
-
-	struct optdata_dn     conndata_in;
-	struct optdata_dn     conndata_out;
-	struct optdata_dn     discdata_in;
-	struct optdata_dn     discdata_out;
-        struct accessdata_dn  accessdata;
-
-        struct sockaddr_dn addr; /* Local address  */
-	struct sockaddr_dn peer; /* Remote address */
-
-	/*
-	 * In this case the RTT estimation is not specified in the
-	 * docs, nor is any back off algorithm. Here we follow well
-	 * known tcp algorithms with a few small variations.
-	 *
-	 * snd_window: Max number of packets we send before we wait for
-	 *             an ack to come back. This will become part of a
-	 *             more complicated scheme when we support flow
-	 *             control.
-	 *
-	 * nsp_srtt:   Round-Trip-Time (x8) in jiffies. This is a rolling
-	 *             average.
-	 * nsp_rttvar: Round-Trip-Time-Varience (x4) in jiffies. This is the
-	 *             varience of the smoothed average (but calculated in
-	 *             a simpler way than for normal statistical varience
-	 *             calculations).
-	 *
-	 * nsp_rxtshift: Backoff counter. Value is zero normally, each time
-	 *               a packet is lost is increases by one until an ack
-	 *               is received. Its used to index an array of backoff
-	 *               multipliers.
-	 */
-#define NSP_MIN_WINDOW 1
-#define NSP_MAX_WINDOW (0x07fe)
-	unsigned long max_window;
-	unsigned long snd_window;
-#define NSP_INITIAL_SRTT (HZ)
-	unsigned long nsp_srtt;
-#define NSP_INITIAL_RTTVAR (HZ*3)
-	unsigned long nsp_rttvar;
-#define NSP_MAXRXTSHIFT 12
-	unsigned long nsp_rxtshift;
-
-	/*
-	 * Output queues, one for data, one for otherdata/linkservice
-	 */
-	struct sk_buff_head data_xmit_queue;
-	struct sk_buff_head other_xmit_queue;
-
-	/*
-	 * Input queue for other data
-	 */
-	struct sk_buff_head other_receive_queue;
-	int other_report;
-
-	/*
-	 * Stuff to do with the slow timer
-	 */
-	unsigned long stamp;          /* time of last transmit */
-	unsigned long persist;
-	int (*persist_fxn)(struct sock *sk);
-	unsigned long keepalive;
-	void (*keepalive_fxn)(struct sock *sk);
-
-};
-
-static inline struct dn_scp *DN_SK(struct sock *sk)
-{
-	return (struct dn_scp *)(sk + 1);
-}
-
-/*
- * src,dst : Source and Destination DECnet addresses
- * hops : Number of hops through the network
- * dst_port, src_port : NSP port numbers
- * services, info : Useful data extracted from conninit messages
- * rt_flags : Routing flags byte
- * nsp_flags : NSP layer flags byte
- * segsize : Size of segment
- * segnum : Number, for data, otherdata and linkservice
- * xmit_count : Number of times we've transmitted this skb
- * stamp : Time stamp of most recent transmission, used in RTT calculations
- * iif: Input interface number
- *
- * As a general policy, this structure keeps all addresses in network
- * byte order, and all else in host byte order. Thus dst, src, dst_port
- * and src_port are in network order. All else is in host order.
- * 
- */
-#define DN_SKB_CB(skb) ((struct dn_skb_cb *)(skb)->cb)
-struct dn_skb_cb {
-	__le16 dst;
-	__le16 src;
-	__u16 hops;
-	__le16 dst_port;
-	__le16 src_port;
-	__u8 services;
-	__u8 info;
-	__u8 rt_flags;
-	__u8 nsp_flags;
-	__u16 segsize;
-	__u16 segnum;
-	__u16 xmit_count;
-	unsigned long stamp;
-	int iif;
-};
-
-static inline __le16 dn_eth2dn(const unsigned char *ethaddr)
-{
-	return get_unaligned((__le16 *)(ethaddr + 4));
-}
-
-static inline __le16 dn_saddr2dn(struct sockaddr_dn *saddr)
-{
-	return *(__le16 *)saddr->sdn_nodeaddr;
-}
-
-static inline void dn_dn2eth(unsigned char *ethaddr, __le16 addr)
-{
-	__u16 a = le16_to_cpu(addr);
-	ethaddr[0] = 0xAA;
-	ethaddr[1] = 0x00;
-	ethaddr[2] = 0x04;
-	ethaddr[3] = 0x00;
-	ethaddr[4] = (__u8)(a & 0xff);
-	ethaddr[5] = (__u8)(a >> 8);
-}
-
-static inline void dn_sk_ports_copy(struct flowidn *fld, struct dn_scp *scp)
-{
-	fld->fld_sport = scp->addrloc;
-	fld->fld_dport = scp->addrrem;
-}
-
-unsigned int dn_mss_from_pmtu(struct net_device *dev, int mtu);
-void dn_register_sysctl(void);
-void dn_unregister_sysctl(void);
-
-#define DN_MENUVER_ACC 0x01
-#define DN_MENUVER_USR 0x02
-#define DN_MENUVER_PRX 0x04
-#define DN_MENUVER_UIC 0x08
-
-struct sock *dn_sklist_find_listener(struct sockaddr_dn *addr);
-struct sock *dn_find_by_skb(struct sk_buff *skb);
-#define DN_ASCBUF_LEN 9
-char *dn_addr2asc(__u16, char *);
-int dn_destroy_timer(struct sock *sk);
-
-int dn_sockaddr2username(struct sockaddr_dn *addr, unsigned char *buf,
-			 unsigned char type);
-int dn_username2sockaddr(unsigned char *data, int len, struct sockaddr_dn *addr,
-			 unsigned char *type);
-
-void dn_start_slow_timer(struct sock *sk);
-void dn_stop_slow_timer(struct sock *sk);
-
-extern __le16 decnet_address;
-extern int decnet_debug_level;
-extern int decnet_time_wait;
-extern int decnet_dn_count;
-extern int decnet_di_count;
-extern int decnet_dr_count;
-extern int decnet_no_fc_max_cwnd;
-
-extern long sysctl_decnet_mem[3];
-extern int sysctl_decnet_wmem[3];
-extern int sysctl_decnet_rmem[3];
-
-#endif /* _NET_DN_H */

include/net/dn_dev.h

-/* SPDX-License-Identifier: GPL-2.0 */
-#ifndef _NET_DN_DEV_H
-#define _NET_DN_DEV_H
-
-#include <linux/netdevice.h>
-
-struct dn_dev;
-
-struct dn_ifaddr {
-	struct dn_ifaddr __rcu *ifa_next;
-	struct dn_dev    *ifa_dev;
-	__le16            ifa_local;
-	__le16            ifa_address;
-	__u32             ifa_flags;
-	__u8              ifa_scope;
-	char              ifa_label[IFNAMSIZ];
-	struct rcu_head   rcu;
-};
-
-#define DN_DEV_S_RU  0 /* Run - working normally   */
-#define DN_DEV_S_CR  1 /* Circuit Rejected         */
-#define DN_DEV_S_DS  2 /* Data Link Start          */
-#define DN_DEV_S_RI  3 /* Routing Layer Initialize */
-#define DN_DEV_S_RV  4 /* Routing Layer Verify     */
-#define DN_DEV_S_RC  5 /* Routing Layer Complete   */
-#define DN_DEV_S_OF  6 /* Off                      */
-#define DN_DEV_S_HA  7 /* Halt                     */
-
-
-/*
- * The dn_dev_parms structure contains the set of parameters
- * for each device (hence inclusion in the dn_dev structure)
- * and an array is used to store the default types of supported
- * device (in dn_dev.c).
- *
- * The type field matches the ARPHRD_ constants and is used in
- * searching the list for supported devices when new devices
- * come up.
- *
- * The mode field is used to find out if a device is broadcast,
- * multipoint, or pointopoint. Please note that DECnet thinks
- * different ways about devices to the rest of the kernel
- * so the normal IFF_xxx flags are invalid here. For devices
- * which can be any combination of the previously mentioned
- * attributes, you can set this on a per device basis by
- * installing an up() routine.
- *
- * The device state field, defines the initial state in which the
- * device will come up. In the dn_dev structure, it is the actual
- * state.
- *
- * Things have changed here. I've killed timer1 since it's a user space
- * issue for a user space routing deamon to sort out. The kernel does
- * not need to be bothered with it.
- *
- * Timers:
- * t2 - Rate limit timer, min time between routing and hello messages
- * t3 - Hello timer, send hello messages when it expires
- *
- * Callbacks:
- * up() - Called to initialize device, return value can veto use of
- *        device with DECnet.
- * down() - Called to turn device off when it goes down
- * timer3() - Called once for each ifaddr when timer 3 goes off
- * 
- * sysctl - Hook for sysctl things
- *
- */
-struct dn_dev_parms {
-	int type;	          /* ARPHRD_xxx                         */
-	int mode;	          /* Broadcast, Unicast, Mulitpoint     */
-#define DN_DEV_BCAST  1
-#define DN_DEV_UCAST  2
-#define DN_DEV_MPOINT 4
-	int state;                /* Initial state                      */
-	int forwarding;	          /* 0=EndNode, 1=L1Router, 2=L2Router  */
-	unsigned long t2;         /* Default value of t2                */
-	unsigned long t3;         /* Default value of t3                */
-	int priority;             /* Priority to be a router            */
-	char *name;               /* Name for sysctl                    */
-	int  (*up)(struct net_device *);
-	void (*down)(struct net_device *);
-	void (*timer3)(struct net_device *, struct dn_ifaddr *ifa);
-	void *sysctl;
-};
-
-
-struct dn_dev {
-	struct dn_ifaddr __rcu *ifa_list;
-	struct net_device *dev;
-	struct dn_dev_parms parms;
-	char use_long;
-	struct timer_list timer;
-	unsigned long t3;
-	struct neigh_parms *neigh_parms;
-	__u8 addr[ETH_ALEN];
-	struct neighbour *router; /* Default router on circuit */
-	struct neighbour *peer;   /* Peer on pointopoint links */
-	unsigned long uptime;     /* Time device went up in jiffies */
-};
-
-struct dn_short_packet {
-	__u8    msgflg;
-	__le16 dstnode;
-	__le16 srcnode;
-	__u8   forward;
-} __packed;
-
-struct dn_long_packet {
-	__u8   msgflg;
-	__u8   d_area;
-	__u8   d_subarea;
-	__u8   d_id[6];
-	__u8   s_area;
-	__u8   s_subarea;
-	__u8   s_id[6];
-	__u8   nl2;
-	__u8   visit_ct;
-	__u8   s_class;
-	__u8   pt;
-} __packed;
-
-/*------------------------- DRP - Routing messages ---------------------*/
-
-struct endnode_hello_message {
-	__u8   msgflg;
-	__u8   tiver[3];
-	__u8   id[6];
-	__u8   iinfo;
-	__le16 blksize;
-	__u8   area;
-	__u8   seed[8];
-	__u8   neighbor[6];
-	__le16 timer;
-	__u8   mpd;
-	__u8   datalen;
-	__u8   data[2];
-} __packed;
-
-struct rtnode_hello_message {
-	__u8   msgflg;
-	__u8   tiver[3];
-	__u8   id[6];
-	__u8   iinfo;
-	__le16  blksize;
-	__u8   priority;
-	__u8   area;
-	__le16  timer;
-	__u8   mpd;
-} __packed;
-
-
-void dn_dev_init(void);
-void dn_dev_cleanup(void);
-
-int dn_dev_ioctl(unsigned int cmd, void __user *arg);
-
-void dn_dev_devices_off(void);
-void dn_dev_devices_on(void);
-
-void dn_dev_init_pkt(struct sk_buff *skb);
-void dn_dev_veri_pkt(struct sk_buff *skb);
-void dn_dev_hello(struct sk_buff *skb);
-
-void dn_dev_up(struct net_device *);
-void dn_dev_down(struct net_device *);
-
-int dn_dev_set_default(struct net_device *dev, int force);
-struct net_device *dn_dev_get_default(void);
-int dn_dev_bind_default(__le16 *addr);
-
-int register_dnaddr_notifier(struct notifier_block *nb);
-int unregister_dnaddr_notifier(struct notifier_block *nb);
-
-static inline int dn_dev_islocal(struct net_device *dev, __le16 addr)
-{
-	struct dn_dev *dn_db;
-	struct dn_ifaddr *ifa;
-	int res = 0;
-
-	rcu_read_lock();
-	dn_db = rcu_dereference(dev->dn_ptr);
-	if (dn_db == NULL) {
-		printk(KERN_DEBUG "dn_dev_islocal: Called for non DECnet device\n");
-		goto out;
-	}
-
-	for (ifa = rcu_dereference(dn_db->ifa_list);
-	     ifa != NULL;
-	     ifa = rcu_dereference(ifa->ifa_next))
-		if ((addr ^ ifa->ifa_local) == 0) {
-			res = 1;
-			break;
-		}
-out:
-	rcu_read_unlock();
-	return res;
-}
-
-#endif /* _NET_DN_DEV_H */

include/net/dn_fib.h

-/* SPDX-License-Identifier: GPL-2.0 */
-#ifndef _NET_DN_FIB_H
-#define _NET_DN_FIB_H
-
-#include <linux/netlink.h>
-#include <linux/refcount.h>
-#include <linux/rtnetlink.h>
-#include <net/fib_rules.h>
-
-extern const struct nla_policy rtm_dn_policy[];
-
-struct dn_fib_res {
-	struct fib_rule *r;
-	struct dn_fib_info *fi;
-	unsigned char prefixlen;
-	unsigned char nh_sel;
-	unsigned char type;
-	unsigned char scope;
-};
-
-struct dn_fib_nh {
-	struct net_device	*nh_dev;
-	unsigned int		nh_flags;
-	unsigned char		nh_scope;
-	int			nh_weight;
-	int			nh_power;
-	int			nh_oif;
-	__le16			nh_gw;
-};
-
-struct dn_fib_info {
-	struct dn_fib_info	*fib_next;
-	struct dn_fib_info	*fib_prev;
-	refcount_t		fib_treeref;
-	refcount_t		fib_clntref;
-	int			fib_dead;
-	unsigned int		fib_flags;
-	int			fib_protocol;
-	__le16			fib_prefsrc;
-	__u32			fib_priority;
-	__u32			fib_metrics[RTAX_MAX];
-	int			fib_nhs;
-	int			fib_power;
-	struct dn_fib_nh	fib_nh[0];
-#define dn_fib_dev		fib_nh[0].nh_dev
-};
-
-
-#define DN_FIB_RES_RESET(res)	((res).nh_sel = 0)
-#define DN_FIB_RES_NH(res)	((res).fi->fib_nh[(res).nh_sel])
-
-#define DN_FIB_RES_PREFSRC(res)	((res).fi->fib_prefsrc ? : __dn_fib_res_prefsrc(&res))
-#define DN_FIB_RES_GW(res)	(DN_FIB_RES_NH(res).nh_gw)
-#define DN_FIB_RES_DEV(res)	(DN_FIB_RES_NH(res).nh_dev)
-#define DN_FIB_RES_OIF(res)	(DN_FIB_RES_NH(res).nh_oif)
-
-typedef struct {
-	__le16	datum;
-} dn_fib_key_t;
-
-typedef struct {
-	__le16	datum;
-} dn_fib_hash_t;
-
-typedef struct {
-	__u16	datum;
-} dn_fib_idx_t;
-
-struct dn_fib_node {
-	struct dn_fib_node *fn_next;
-	struct dn_fib_info *fn_info;
-#define DN_FIB_INFO(f) ((f)->fn_info)
-	dn_fib_key_t	fn_key;
-	u8		fn_type;
-	u8		fn_scope;
-	u8		fn_state;
-};
-
-
-struct dn_fib_table {
-	struct hlist_node hlist;
-	u32 n;
-
-	int (*insert)(struct dn_fib_table *t, struct rtmsg *r, 
-			struct nlattr *attrs[], struct nlmsghdr *n,
-			struct netlink_skb_parms *req);
-	int (*delete)(struct dn_fib_table *t, struct rtmsg *r,
-			struct nlattr *attrs[], struct nlmsghdr *n,
-			struct netlink_skb_parms *req);
-	int (*lookup)(struct dn_fib_table *t, const struct flowidn *fld,
-			struct dn_fib_res *res);
-	int (*flush)(struct dn_fib_table *t);
-	int (*dump)(struct dn_fib_table *t, struct sk_buff *skb, struct netlink_callback *cb);
-
-	unsigned char data[];
-};
-
-#ifdef CONFIG_DECNET_ROUTER
-/*
- * dn_fib.c
- */
-void dn_fib_init(void);
-void dn_fib_cleanup(void);
-
-int dn_fib_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg);
-struct dn_fib_info *dn_fib_create_info(const struct rtmsg *r,
-				       struct nlattr *attrs[],
-				       const struct nlmsghdr *nlh, int *errp);
-int dn_fib_semantic_match(int type, struct dn_fib_info *fi,
-			  const struct flowidn *fld, struct dn_fib_res *res);
-void dn_fib_release_info(struct dn_fib_info *fi);
-void dn_fib_flush(void);
-void dn_fib_select_multipath(const struct flowidn *fld, struct dn_fib_res *res);
-
-/*
- * dn_tables.c
- */
-struct dn_fib_table *dn_fib_get_table(u32 n, int creat);
-struct dn_fib_table *dn_fib_empty_table(void);
-void dn_fib_table_init(void);
-void dn_fib_table_cleanup(void);
-
-/*
- * dn_rules.c
- */
-void dn_fib_rules_init(void);
-void dn_fib_rules_cleanup(void);
-unsigned int dnet_addr_type(__le16 addr);
-int dn_fib_lookup(struct flowidn *fld, struct dn_fib_res *res);
-
-int dn_fib_dump(struct sk_buff *skb, struct netlink_callback *cb);
-
-void dn_fib_free_info(struct dn_fib_info *fi);
-
-static inline void dn_fib_info_put(struct dn_fib_info *fi)
-{
-	if (refcount_dec_and_test(&fi->fib_clntref))
-		dn_fib_free_info(fi);
-}
-
-static inline void dn_fib_res_put(struct dn_fib_res *res)
-{
-	if (res->fi)
-		dn_fib_info_put(res->fi);
-	if (res->r)
-		fib_rule_put(res->r);
-}
-
-#else /* Endnode */
-
-#define dn_fib_init()  do { } while(0)
-#define dn_fib_cleanup() do { } while(0)
-
-#define dn_fib_lookup(fl, res) (-ESRCH)
-#define dn_fib_info_put(fi) do { } while(0)
-#define dn_fib_select_multipath(fl, res) do { } while(0)
-#define dn_fib_rules_policy(saddr,res,flags) (0)
-#define dn_fib_res_put(res) do { } while(0)
-
-#endif /* CONFIG_DECNET_ROUTER */
-
-static inline __le16 dnet_make_mask(int n)
-{
-	if (n)
-		return cpu_to_le16(~((1 << (16 - n)) - 1));
-	return cpu_to_le16(0);
-}
-
-#endif /* _NET_DN_FIB_H */

include/net/dn_neigh.h

-/* SPDX-License-Identifier: GPL-2.0 */
-#ifndef _NET_DN_NEIGH_H
-#define _NET_DN_NEIGH_H
-
-#include <net/neighbour.h>
-
-/*
- * The position of the first two fields of
- * this structure are critical - SJW
- */
-struct dn_neigh {
-        struct neighbour n;
-	__le16 addr;
-        unsigned long flags;
-#define DN_NDFLAG_R1    0x0001 /* Router L1      */
-#define DN_NDFLAG_R2    0x0002 /* Router L2      */
-#define DN_NDFLAG_P3    0x0004 /* Phase III Node */
-        unsigned long blksize;
-	__u8 priority;
-};
-
-void dn_neigh_init(void);
-void dn_neigh_cleanup(void);
-int dn_neigh_router_hello(struct net *net, struct sock *sk, struct sk_buff *skb);
-int dn_neigh_endnode_hello(struct net *net, struct sock *sk, struct sk_buff *skb);
-void dn_neigh_pointopoint_hello(struct sk_buff *skb);
-int dn_neigh_elist(struct net_device *dev, unsigned char *ptr, int n);
-int dn_to_neigh_output(struct net *net, struct sock *sk, struct sk_buff *skb);
-
-extern struct neigh_table dn_neigh_table;
-
-#endif /* _NET_DN_NEIGH_H */

include/net/dn_nsp.h

-/* SPDX-License-Identifier: GPL-2.0-or-later */
-#ifndef _NET_DN_NSP_H
-#define _NET_DN_NSP_H
-/******************************************************************************
-    (c) 1995-1998 E.M. Serrat		emserrat@geocities.com
-    
-*******************************************************************************/
-/* dn_nsp.c functions prototyping */
-#include <linux/atomic.h>
-#include <linux/types.h>
-#include <net/sock.h>
-
-struct sk_buff;
-struct sk_buff_head;
-
-void dn_nsp_send_data_ack(struct sock *sk);
-void dn_nsp_send_oth_ack(struct sock *sk);
-void dn_send_conn_ack(struct sock *sk);
-void dn_send_conn_conf(struct sock *sk, gfp_t gfp);
-void dn_nsp_send_disc(struct sock *sk, unsigned char type,
-		      unsigned short reason, gfp_t gfp);
-void dn_nsp_return_disc(struct sk_buff *skb, unsigned char type,
-			unsigned short reason);
-void dn_nsp_send_link(struct sock *sk, unsigned char lsflags, char fcval);
-void dn_nsp_send_conninit(struct sock *sk, unsigned char flags);
-
-void dn_nsp_output(struct sock *sk);
-int dn_nsp_check_xmit_queue(struct sock *sk, struct sk_buff *skb,
-			    struct sk_buff_head *q, unsigned short acknum);
-void dn_nsp_queue_xmit(struct sock *sk, struct sk_buff *skb, gfp_t gfp,
-		       int oob);
-unsigned long dn_nsp_persist(struct sock *sk);
-int dn_nsp_xmit_timeout(struct sock *sk);
-
-int dn_nsp_rx(struct sk_buff *);
-int dn_nsp_backlog_rcv(struct sock *sk, struct sk_buff *skb);
-
-struct sk_buff *dn_alloc_skb(struct sock *sk, int size, gfp_t pri);
-struct sk_buff *dn_alloc_send_skb(struct sock *sk, size_t *size, int noblock,
-				  long timeo, int *err);
-
-#define NSP_REASON_OK 0		/* No error */
-#define NSP_REASON_NR 1		/* No resources */
-#define NSP_REASON_UN 2		/* Unrecognised node name */
-#define NSP_REASON_SD 3		/* Node shutting down */
-#define NSP_REASON_ID 4		/* Invalid destination end user */
-#define NSP_REASON_ER 5		/* End user lacks resources */
-#define NSP_REASON_OB 6		/* Object too busy */
-#define NSP_REASON_US 7		/* Unspecified error */
-#define NSP_REASON_TP 8		/* Third-Party abort */
-#define NSP_REASON_EA 9		/* End user has aborted the link */
-#define NSP_REASON_IF 10	/* Invalid node name format */
-#define NSP_REASON_LS 11	/* Local node shutdown */
-#define NSP_REASON_LL 32	/* Node lacks logical-link resources */
-#define NSP_REASON_LE 33	/* End user lacks logical-link resources */
-#define NSP_REASON_UR 34	/* Unacceptable RQSTRID or PASSWORD field */
-#define NSP_REASON_UA 36	/* Unacceptable ACCOUNT field */
-#define NSP_REASON_TM 38	/* End user timed out logical link */
-#define NSP_REASON_NU 39	/* Node unreachable */
-#define NSP_REASON_NL 41	/* No-link message */
-#define NSP_REASON_DC 42	/* Disconnect confirm */
-#define NSP_REASON_IO 43	/* Image data field overflow */
-
-#define NSP_DISCINIT 0x38
-#define NSP_DISCCONF 0x48
-
-/*------------------------- NSP - messages ------------------------------*/
-/* Data Messages */
-/*---------------*/
-
-/* Data Messages    (data segment/interrupt/link service)               */
-
-struct nsp_data_seg_msg {
-	__u8   msgflg;
-	__le16 dstaddr;
-	__le16 srcaddr;
-} __packed;
-
-struct nsp_data_opt_msg {
-	__le16 acknum;
-	__le16 segnum;
-	__le16 lsflgs;
-} __packed;
-
-struct nsp_data_opt_msg1 {
-	__le16 acknum;
-	__le16 segnum;
-} __packed;
-
-
-/* Acknowledgment Message (data/other data)                             */
-struct nsp_data_ack_msg {
-	__u8   msgflg;
-	__le16 dstaddr;
-	__le16 srcaddr;
-	__le16 acknum;
-} __packed;
-
-/* Connect Acknowledgment Message */
-struct  nsp_conn_ack_msg {
-	__u8 msgflg;
-	__le16 dstaddr;
-} __packed;
-
-
-/* Connect Initiate/Retransmit Initiate/Connect Confirm */
-struct  nsp_conn_init_msg {
-	__u8   msgflg;
-#define NSP_CI      0x18            /* Connect Initiate     */
-#define NSP_RCI     0x68            /* Retrans. Conn Init   */
-	__le16 dstaddr;
-	__le16 srcaddr;
-	__u8   services;
-#define NSP_FC_NONE   0x00            /* Flow Control None    */
-#define NSP_FC_SRC    0x04            /* Seg Req. Count       */
-#define NSP_FC_SCMC   0x08            /* Sess. Control Mess   */
-#define NSP_FC_MASK   0x0c            /* FC type mask         */
-	__u8   info;
-	__le16 segsize;
-} __packed;
-
-/* Disconnect Initiate/Disconnect Confirm */
-struct  nsp_disconn_init_msg {
-	__u8   msgflg;
-	__le16 dstaddr;
-	__le16 srcaddr;
-	__le16 reason;
-} __packed;
-
-
-
-struct  srcobj_fmt {
-	__u8   format;
-	__u8   task;
-	__le16 grpcode;
-	__le16 usrcode;
-	__u8   dlen;
-} __packed;
-
-/*
- * A collection of functions for manipulating the sequence
- * numbers used in NSP. Similar in operation to the functions
- * of the same name in TCP.
- */
-static __inline__ int dn_before(__u16 seq1, __u16 seq2)
-{
-        seq1 &= 0x0fff;
-        seq2 &= 0x0fff;
-
-        return (int)((seq1 - seq2) & 0x0fff) > 2048;
-}
-
-
-static __inline__ int dn_after(__u16 seq1, __u16 seq2)
-{
-        seq1 &= 0x0fff;
-        seq2 &= 0x0fff;
-
-        return (int)((seq2 - seq1) & 0x0fff) > 2048;
-}
-
-static __inline__ int dn_equal(__u16 seq1, __u16 seq2)
-{
-        return ((seq1 ^ seq2) & 0x0fff) == 0;
-}
-
-static __inline__ int dn_before_or_equal(__u16 seq1, __u16 seq2)
-{
-	return (dn_before(seq1, seq2) || dn_equal(seq1, seq2));
-}
-
-static __inline__ void seq_add(__u16 *seq, __u16 off)
-{
-        (*seq) += off;
-        (*seq) &= 0x0fff;
-}
-
-static __inline__ int seq_next(__u16 seq1, __u16 seq2)
-{
-	return dn_equal(seq1 + 1, seq2);
-}
-
-/*
- * Can we delay the ack ?
- */
-static __inline__ int sendack(__u16 seq)
-{
-        return (int)((seq & 0x1000) ? 0 : 1);
-}
-
-/*
- * Is socket congested ?
- */
-static __inline__ int dn_congested(struct sock *sk)
-{
-        return atomic_read(&sk->sk_rmem_alloc) > (sk->sk_rcvbuf >> 1);
-}
-
-#define DN_MAX_NSP_DATA_HEADER (11)
-
-#endif /* _NET_DN_NSP_H */

include/net/dn_route.h

-/* SPDX-License-Identifier: GPL-2.0-or-later */
-#ifndef _NET_DN_ROUTE_H
-#define _NET_DN_ROUTE_H
-
-/******************************************************************************
-    (c) 1995-1998 E.M. Serrat		emserrat@geocities.com
-    
-*******************************************************************************/
-
-#include <linux/types.h>
-#include <net/dst.h>
-
-struct sk_buff *dn_alloc_skb(struct sock *sk, int size, gfp_t pri);
-int dn_route_output_sock(struct dst_entry __rcu **pprt, struct flowidn *,
-			 struct sock *sk, int flags);
-int dn_cache_dump(struct sk_buff *skb, struct netlink_callback *cb);
-void dn_rt_cache_flush(int delay);
-int dn_route_rcv(struct sk_buff *skb, struct net_device *dev,
-		 struct packet_type *pt, struct net_device *orig_dev);
-
-/* Masks for flags field */
-#define DN_RT_F_PID 0x07 /* Mask for packet type                      */
-#define DN_RT_F_PF  0x80 /* Padding Follows                           */
-#define DN_RT_F_VER 0x40 /* Version =0 discard packet if ==1          */
-#define DN_RT_F_IE  0x20 /* Intra Ethernet, Reserved in short pkt     */
-#define DN_RT_F_RTS 0x10 /* Packet is being returned to sender        */
-#define DN_RT_F_RQR 0x08 /* Return packet to sender upon non-delivery */
-
-/* Mask for types of routing packets */
-#define DN_RT_PKT_MSK   0x06
-/* Types of routing packets */
-#define DN_RT_PKT_SHORT 0x02 /* Short routing packet */
-#define DN_RT_PKT_LONG  0x06 /* Long routing packet  */
-
-/* Mask for control/routing selection */
-#define DN_RT_PKT_CNTL  0x01 /* Set to 1 if a control packet  */
-/* Types of control packets */
-#define DN_RT_CNTL_MSK  0x0f /* Mask for control packets      */
-#define DN_RT_PKT_INIT  0x01 /* Initialisation packet         */
-#define DN_RT_PKT_VERI  0x03 /* Verification Message          */
-#define DN_RT_PKT_HELO  0x05 /* Hello and Test Message        */
-#define DN_RT_PKT_L1RT  0x07 /* Level 1 Routing Message       */
-#define DN_RT_PKT_L2RT  0x09 /* Level 2 Routing Message       */
-#define DN_RT_PKT_ERTH  0x0b /* Ethernet Router Hello         */
-#define DN_RT_PKT_EEDH  0x0d /* Ethernet EndNode Hello        */
-
-/* Values for info field in hello message */
-#define DN_RT_INFO_TYPE 0x03 /* Type mask                     */
-#define DN_RT_INFO_L1RT 0x02 /* L1 Router                     */
-#define DN_RT_INFO_L2RT 0x01 /* L2 Router                     */
-#define DN_RT_INFO_ENDN 0x03 /* EndNode                       */
-#define DN_RT_INFO_VERI 0x04 /* Verification Reqd.            */
-#define DN_RT_INFO_RJCT 0x08 /* Reject Flag, Reserved         */
-#define DN_RT_INFO_VFLD 0x10 /* Verification Failed, Reserved */
-#define DN_RT_INFO_NOML 0x20 /* No Multicast traffic accepted */
-#define DN_RT_INFO_BLKR 0x40 /* Blocking Requested            */
-
-/*
- * The fl structure is what we used to look up the route.
- * The rt_saddr & rt_daddr entries are the same as key.saddr & key.daddr
- * except for local input routes, where the rt_saddr = fl.fld_dst and
- * rt_daddr = fl.fld_src to allow the route to be used for returning
- * packets to the originating host.
- */
-struct dn_route {
-	struct dst_entry dst;
-	struct dn_route __rcu *dn_next;
-
-	struct neighbour *n;
-
-	struct flowidn fld;
-
-	__le16 rt_saddr;
-	__le16 rt_daddr;
-	__le16 rt_gateway;
-	__le16 rt_local_src;	/* Source used for forwarding packets */
-	__le16 rt_src_map;
-	__le16 rt_dst_map;
-
-	unsigned int rt_flags;
-	unsigned int rt_type;
-};
-
-static inline bool dn_is_input_route(struct dn_route *rt)
-{
-	return rt->fld.flowidn_iif != 0;
-}
-
-static inline bool dn_is_output_route(struct dn_route *rt)
-{
-	return rt->fld.flowidn_iif == 0;
-}
-
-void dn_route_init(void);
-void dn_route_cleanup(void);
-
-#include <net/sock.h>
-#include <linux/if_arp.h>
-
-static inline void dn_rt_send(struct sk_buff *skb)
-{
-	dev_queue_xmit(skb);
-}
-
-static inline void dn_rt_finish_output(struct sk_buff *skb, char *dst, char *src)
-{
-	struct net_device *dev = skb->dev;
-
-	if ((dev->type != ARPHRD_ETHER) && (dev->type != ARPHRD_LOOPBACK))
-		dst = NULL;
-
-	if (dev_hard_header(skb, dev, ETH_P_DNA_RT, dst, src, skb->len) >= 0)
-		dn_rt_send(skb);
-	else
-		kfree_skb(skb);
-}
-
-#endif /* _NET_DN_ROUTE_H */

include/net/netns/netfilter.h

@@ -24,9 +24,6 @@ struct netns_nf {
 #ifdef CONFIG_NETFILTER_FAMILY_BRIDGE
 	struct nf_hook_entries __rcu *hooks_bridge[NF_INET_NUMHOOKS];
 #endif
-#if IS_ENABLED(CONFIG_DECNET)
-	struct nf_hook_entries __rcu *hooks_decnet[NF_DN_NUMHOOKS];
-#endif
 #if IS_ENABLED(CONFIG_NF_DEFRAG_IPV4)
 	unsigned int defrag_ipv4_users;
 #endif

include/uapi/linux/dn.h

-/* 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 */

include/uapi/linux/netfilter_decnet.h

-/* 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*/

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) */

net/Kconfig

@@ -204,7 +204,6 @@ config BRIDGE_NETFILTER
 source "net/netfilter/Kconfig"
 source "net/ipv4/netfilter/Kconfig"
 source "net/ipv6/netfilter/Kconfig"
-source "net/decnet/netfilter/Kconfig"
 source "net/bridge/netfilter/Kconfig"
 
 endif
@@ -221,7 +220,6 @@ source "net/802/Kconfig"
 source "net/bridge/Kconfig"
 source "net/dsa/Kconfig"
 source "net/8021q/Kconfig"
-source "net/decnet/Kconfig"
 source "net/llc/Kconfig"
 source "drivers/net/appletalk/Kconfig"
 source "net/x25/Kconfig"

net/Makefile

@@ -38,7 +38,6 @@ obj-$(CONFIG_AF_KCM)		+= kcm/
 obj-$(CONFIG_STREAM_PARSER)	+= strparser/
 obj-$(CONFIG_ATM)		+= atm/
 obj-$(CONFIG_L2TP)		+= l2tp/
-obj-$(CONFIG_DECNET)		+= decnet/
 obj-$(CONFIG_PHONET)		+= phonet/
 ifneq ($(CONFIG_VLAN_8021Q),)
 obj-y				+= 8021q/

net/core/dev.c

@@ -10370,9 +10370,7 @@ void netdev_run_todo(void)
 		BUG_ON(!list_empty(&dev->ptype_specific));
 		WARN_ON(rcu_access_pointer(dev->ip_ptr));
 		WARN_ON(rcu_access_pointer(dev->ip6_ptr));
-#if IS_ENABLED(CONFIG_DECNET)
-		WARN_ON(dev->dn_ptr);
-#endif
+
 		if (dev->priv_destructor)
 			dev->priv_destructor(dev);
 		if (dev->needs_free_netdev)

net/core/neighbour.c

@@ -1847,9 +1847,6 @@ static struct neigh_table *neigh_find_table(int family)
 	case AF_INET6:
 		tbl = neigh_tables[NEIGH_ND_TABLE];
 		break;
-	case AF_DECnet:
-		tbl = neigh_tables[NEIGH_DN_TABLE];
-		break;
 	}
 
 	return tbl;

net/decnet/Kconfig

-# SPDX-License-Identifier: GPL-2.0-only
-#
-# DECnet configuration
-#
-config DECNET
-	tristate "DECnet Support"
-	help
-	  The DECnet networking protocol was used in many products made by
-	  Digital (now Compaq).  It provides reliable stream and sequenced
-	  packet communications over which run a variety of services similar
-	  to those which run over TCP/IP.
-
-	  To find some tools to use with the kernel layer support, please
-	  look at Patrick Caulfield's web site:
-	  <http://linux-decnet.sourceforge.net/>.
-
-	  More detailed documentation is available in
-	  <file:Documentation/networking/decnet.rst>.
-
-	  Be sure to say Y to "/proc file system support" and "Sysctl support"
-	  below when using DECnet, since you will need sysctl support to aid
-	  in configuration at run time.
-
-	  The DECnet code is also available as a module ( = code which can be
-	  inserted in and removed from the running kernel whenever you want).
-	  The module is called decnet.
-
-config DECNET_ROUTER
-	bool "DECnet: router support"
-	depends on DECNET
-	select FIB_RULES
-	help
-	  Add support for turning your DECnet Endnode into a level 1 or 2
-	  router.  This is an experimental, but functional option.  If you
-	  do say Y here, then make sure that you also say Y to "Kernel/User
-	  network link driver", "Routing messages" and "Network packet
-	  filtering".  The first two are required to allow configuration via
-	  rtnetlink (you will need Alexey Kuznetsov's iproute2 package
-	  from <ftp://ftp.tux.org/pub/net/ip-routing/>). The "Network packet
-	  filtering" option will be required for the forthcoming routing daemon
-	  to work.
-
-	  See <file:Documentation/networking/decnet.rst> for more information.

net/decnet/Makefile

-# SPDX-License-Identifier: GPL-2.0
-
-obj-$(CONFIG_DECNET) += decnet.o
-
-decnet-y := af_decnet.o dn_nsp_in.o dn_nsp_out.o \
-	    dn_route.o dn_dev.o dn_neigh.o dn_timer.o
-decnet-$(CONFIG_DECNET_ROUTER) += dn_fib.o dn_rules.o dn_table.o
-decnet-y += sysctl_net_decnet.o
-
-obj-$(CONFIG_NETFILTER) += netfilter/

net/decnet/README

-                       Linux DECnet Project
-                      ======================
-
-The documentation for this kernel subsystem is available in the
-Documentation/networking subdirectory of this distribution and also
-on line at http://www.chygwyn.com/DECnet/
-
-Steve Whitehouse <SteveW@ACM.org>

net/decnet/netfilter/Kconfig

-# SPDX-License-Identifier: GPL-2.0-only
-#
-# DECnet netfilter configuration
-#
-
-menu "DECnet: Netfilter Configuration"
-	depends on DECNET && NETFILTER
-	depends on NETFILTER_ADVANCED
-
-config DECNET_NF_GRABULATOR
-	tristate "Routing message grabulator (for userland routing daemon)"
-	help
-	  Enable this module if you want to use the userland DECnet routing
-	  daemon. You will also need to enable routing support for DECnet
-	  unless you just want to monitor routing messages from other nodes.
-
-endmenu

net/decnet/netfilter/Makefile

-# SPDX-License-Identifier: GPL-2.0-only
-#
-# Makefile for DECnet netfilter modules
-#
-
-obj-$(CONFIG_DECNET_NF_GRABULATOR) += dn_rtmsg.o

net/netfilter/core.c

@@ -300,12 +300,6 @@ nf_hook_entry_head(struct net *net, int pf, unsigned int hooknum,
 		if (WARN_ON_ONCE(ARRAY_SIZE(net->nf.hooks_ipv6) <= hooknum))
 			return NULL;
 		return net->nf.hooks_ipv6 + hooknum;
-#if IS_ENABLED(CONFIG_DECNET)
-	case NFPROTO_DECNET:
-		if (WARN_ON_ONCE(ARRAY_SIZE(net->nf.hooks_decnet) <= hooknum))
-			return NULL;
-		return net->nf.hooks_decnet + hooknum;
-#endif
 	default:
 		WARN_ON_ONCE(1);
 		return NULL;
@@ -750,10 +744,6 @@ static int __net_init netfilter_net_init(struct net *net)
 #ifdef CONFIG_NETFILTER_FAMILY_BRIDGE
 	__netfilter_net_init(net->nf.hooks_bridge, ARRAY_SIZE(net->nf.hooks_bridge));
 #endif
-#if IS_ENABLED(CONFIG_DECNET)
-	__netfilter_net_init(net->nf.hooks_decnet, ARRAY_SIZE(net->nf.hooks_decnet));
-#endif
-
 #ifdef CONFIG_PROC_FS
 	net->nf.proc_netfilter = proc_net_mkdir(net, "netfilter",
 						net->proc_net);

net/netfilter/nfnetlink_hook.c

@@ -215,13 +215,6 @@ nfnl_hook_entries_head(u8 pf, unsigned int hook, struct net *net, const char *de
 		hook_head = rcu_dereference(net->nf.hooks_bridge[hook]);
 #endif
 		break;
-#if IS_ENABLED(CONFIG_DECNET)
-	case NFPROTO_DECNET:
-		if (hook >= ARRAY_SIZE(net->nf.hooks_decnet))
-			return ERR_PTR(-EINVAL);
-		hook_head = rcu_dereference(net->nf.hooks_decnet[hook]);
-		break;
-#endif
 #if defined(CONFIG_NETFILTER_INGRESS) || defined(CONFIG_NETFILTER_EGRESS)
 	case NFPROTO_NETDEV:
 		if (hook >= NF_NETDEV_NUMHOOKS)