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>

1 files changed, 0 insertions, 253 deletions

diff --git a/net/decnet/dn_rules.c b/net/decnet/dn_rules.c
deleted file mode 100644
index ee73057529cf..000000000000
--- a/net/decnet/dn_rules.c
+++ /dev/null
@@ -1,253 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0
-
-/*
- * DECnet       An implementation of the DECnet protocol suite for the LINUX
- *              operating system.  DECnet is implemented using the  BSD Socket
- *              interface as the means of communication with the user level.
- *
- *              DECnet Routing Forwarding Information Base (Rules)
- *
- * Author:      Steve Whitehouse <SteveW@ACM.org>
- *              Mostly copied from Alexey Kuznetsov's ipv4/fib_rules.c
- *
- *
- * Changes:
- *              Steve Whitehouse <steve@chygwyn.com>
- *              Updated for Thomas Graf's generic rules
- *
- */
-#include <linux/net.h>
-#include <linux/init.h>
-#include <linux/netlink.h>
-#include <linux/rtnetlink.h>
-#include <linux/netdevice.h>
-#include <linux/spinlock.h>
-#include <linux/list.h>
-#include <linux/rcupdate.h>
-#include <linux/export.h>
-#include <net/neighbour.h>
-#include <net/dst.h>
-#include <net/flow.h>
-#include <net/fib_rules.h>
-#include <net/dn.h>
-#include <net/dn_fib.h>
-#include <net/dn_neigh.h>
-#include <net/dn_dev.h>
-#include <net/dn_route.h>
-
-static struct fib_rules_ops *dn_fib_rules_ops;
-
-struct dn_fib_rule
-{
-	struct fib_rule		common;
-	unsigned char		dst_len;
-	unsigned char		src_len;
-	__le16			src;
-	__le16			srcmask;
-	__le16			dst;
-	__le16			dstmask;
-	__le16			srcmap;
-	u8			flags;
-};
-
-
-int dn_fib_lookup(struct flowidn *flp, struct dn_fib_res *res)
-{
-	struct fib_lookup_arg arg = {
-		.result = res,
-	};
-	int err;
-
-	err = fib_rules_lookup(dn_fib_rules_ops,
-			       flowidn_to_flowi(flp), 0, &arg);
-	res->r = arg.rule;
-
-	return err;
-}
-
-static int dn_fib_rule_action(struct fib_rule *rule, struct flowi *flp,
-			      int flags, struct fib_lookup_arg *arg)
-{
-	struct flowidn *fld = &flp->u.dn;
-	int err = -EAGAIN;
-	struct dn_fib_table *tbl;
-
-	switch(rule->action) {
-	case FR_ACT_TO_TBL:
-		break;
-
-	case FR_ACT_UNREACHABLE:
-		err = -ENETUNREACH;
-		goto errout;
-
-	case FR_ACT_PROHIBIT:
-		err = -EACCES;
-		goto errout;
-
-	case FR_ACT_BLACKHOLE:
-	default:
-		err = -EINVAL;
-		goto errout;
-	}
-
-	tbl = dn_fib_get_table(rule->table, 0);
-	if (tbl == NULL)
-		goto errout;
-
-	err = tbl->lookup(tbl, fld, (struct dn_fib_res *)arg->result);
-	if (err > 0)
-		err = -EAGAIN;
-errout:
-	return err;
-}
-
-static int dn_fib_rule_match(struct fib_rule *rule, struct flowi *fl, int flags)
-{
-	struct dn_fib_rule *r = (struct dn_fib_rule *)rule;
-	struct flowidn *fld = &fl->u.dn;
-	__le16 daddr = fld->daddr;
-	__le16 saddr = fld->saddr;
-
-	if (((saddr ^ r->src) & r->srcmask) ||
-	    ((daddr ^ r->dst) & r->dstmask))
-		return 0;
-
-	return 1;
-}
-
-static int dn_fib_rule_configure(struct fib_rule *rule, struct sk_buff *skb,
-				 struct fib_rule_hdr *frh,
-				 struct nlattr **tb,
-				 struct netlink_ext_ack *extack)
-{
-	int err = -EINVAL;
-	struct dn_fib_rule *r = (struct dn_fib_rule *)rule;
-
-	if (frh->tos) {
-		NL_SET_ERR_MSG(extack, "Invalid tos value");
-		goto  errout;
-	}
-
-	if (rule->table == RT_TABLE_UNSPEC) {
-		if (rule->action == FR_ACT_TO_TBL) {
-			struct dn_fib_table *table;
-
-			table = dn_fib_empty_table();
-			if (table == NULL) {
-				err = -ENOBUFS;
-				goto errout;
-			}
-
-			rule->table = table->n;
-		}
-	}
-
-	if (frh->src_len)
-		r->src = nla_get_le16(tb[FRA_SRC]);
-
-	if (frh->dst_len)
-		r->dst = nla_get_le16(tb[FRA_DST]);
-
-	r->src_len = frh->src_len;
-	r->srcmask = dnet_make_mask(r->src_len);
-	r->dst_len = frh->dst_len;
-	r->dstmask = dnet_make_mask(r->dst_len);
-	err = 0;
-errout:
-	return err;
-}
-
-static int dn_fib_rule_compare(struct fib_rule *rule, struct fib_rule_hdr *frh,
-			       struct nlattr **tb)
-{
-	struct dn_fib_rule *r = (struct dn_fib_rule *)rule;
-
-	if (frh->src_len && (r->src_len != frh->src_len))
-		return 0;
-
-	if (frh->dst_len && (r->dst_len != frh->dst_len))
-		return 0;
-
-	if (frh->src_len && (r->src != nla_get_le16(tb[FRA_SRC])))
-		return 0;
-
-	if (frh->dst_len && (r->dst != nla_get_le16(tb[FRA_DST])))
-		return 0;
-
-	return 1;
-}
-
-unsigned int dnet_addr_type(__le16 addr)
-{
-	struct flowidn fld = { .daddr = addr };
-	struct dn_fib_res res;
-	unsigned int ret = RTN_UNICAST;
-	struct dn_fib_table *tb = dn_fib_get_table(RT_TABLE_LOCAL, 0);
-
-	res.r = NULL;
-
-	if (tb) {
-		if (!tb->lookup(tb, &fld, &res)) {
-			ret = res.type;
-			dn_fib_res_put(&res);
-		}
-	}
-	return ret;
-}
-
-static int dn_fib_rule_fill(struct fib_rule *rule, struct sk_buff *skb,
-			    struct fib_rule_hdr *frh)
-{
-	struct dn_fib_rule *r = (struct dn_fib_rule *)rule;
-
-	frh->dst_len = r->dst_len;
-	frh->src_len = r->src_len;
-	frh->tos = 0;
-
-	if ((r->dst_len &&
-	     nla_put_le16(skb, FRA_DST, r->dst)) ||
-	    (r->src_len &&
-	     nla_put_le16(skb, FRA_SRC, r->src)))
-		goto nla_put_failure;
-	return 0;
-
-nla_put_failure:
-	return -ENOBUFS;
-}
-
-static void dn_fib_rule_flush_cache(struct fib_rules_ops *ops)
-{
-	dn_rt_cache_flush(-1);
-}
-
-static const struct fib_rules_ops __net_initconst dn_fib_rules_ops_template = {
-	.family		= AF_DECnet,
-	.rule_size	= sizeof(struct dn_fib_rule),
-	.addr_size	= sizeof(u16),
-	.action		= dn_fib_rule_action,
-	.match		= dn_fib_rule_match,
-	.configure	= dn_fib_rule_configure,
-	.compare	= dn_fib_rule_compare,
-	.fill		= dn_fib_rule_fill,
-	.flush_cache	= dn_fib_rule_flush_cache,
-	.nlgroup	= RTNLGRP_DECnet_RULE,
-	.owner		= THIS_MODULE,
-	.fro_net	= &init_net,
-};
-
-void __init dn_fib_rules_init(void)
-{
-	dn_fib_rules_ops =
-		fib_rules_register(&dn_fib_rules_ops_template, &init_net);
-	BUG_ON(IS_ERR(dn_fib_rules_ops));
-	BUG_ON(fib_default_rule_add(dn_fib_rules_ops, 0x7fff,
-			            RT_TABLE_MAIN, 0));
-}
-
-void __exit dn_fib_rules_cleanup(void)
-{
-	rtnl_lock();
-	fib_rules_unregister(dn_fib_rules_ops);
-	rtnl_unlock();
-	rcu_barrier();
-}