1 // SPDX-License-Identifier: GPL-2.0
2
3 /*
4 * DECnet An implementation of the DECnet protocol suite for the LINUX
5 * operating system. DECnet is implemented using the BSD Socket
6 * interface as the means of communication with the user level.
7 *
8 * DECnet Routing Forwarding Information Base (Rules)
9 *
10 * Author: Steve Whitehouse <SteveW@ACM.org>
11 * Mostly copied from Alexey Kuznetsov's ipv4/fib_rules.c
12 *
13 *
14 * Changes:
15 * Steve Whitehouse <steve@chygwyn.com>
16 * Updated for Thomas Graf's generic rules
17 *
18 */
19 #include <linux/net.h>
20 #include <linux/init.h>
21 #include <linux/netlink.h>
22 #include <linux/rtnetlink.h>
23 #include <linux/netdevice.h>
24 #include <linux/spinlock.h>
25 #include <linux/list.h>
26 #include <linux/rcupdate.h>
27 #include <linux/export.h>
28 #include <net/neighbour.h>
29 #include <net/dst.h>
30 #include <net/flow.h>
31 #include <net/fib_rules.h>
32 #include <net/dn.h>
33 #include <net/dn_fib.h>
34 #include <net/dn_neigh.h>
35 #include <net/dn_dev.h>
36 #include <net/dn_route.h>
37
38 static struct fib_rules_ops *dn_fib_rules_ops;
39
40 struct dn_fib_rule
41 {
42 struct fib_rule common;
43 unsigned char dst_len;
44 unsigned char src_len;
45 __le16 src;
46 __le16 srcmask;
47 __le16 dst;
48 __le16 dstmask;
49 __le16 srcmap;
50 u8 flags;
51 };
52
53
dn_fib_lookup(struct flowidn * flp,struct dn_fib_res * res)54 int dn_fib_lookup(struct flowidn *flp, struct dn_fib_res *res)
55 {
56 struct fib_lookup_arg arg = {
57 .result = res,
58 };
59 int err;
60
61 err = fib_rules_lookup(dn_fib_rules_ops,
62 flowidn_to_flowi(flp), 0, &arg);
63 res->r = arg.rule;
64
65 return err;
66 }
67
dn_fib_rule_action(struct fib_rule * rule,struct flowi * flp,int flags,struct fib_lookup_arg * arg)68 static int dn_fib_rule_action(struct fib_rule *rule, struct flowi *flp,
69 int flags, struct fib_lookup_arg *arg)
70 {
71 struct flowidn *fld = &flp->u.dn;
72 int err = -EAGAIN;
73 struct dn_fib_table *tbl;
74
75 switch(rule->action) {
76 case FR_ACT_TO_TBL:
77 break;
78
79 case FR_ACT_UNREACHABLE:
80 err = -ENETUNREACH;
81 goto errout;
82
83 case FR_ACT_PROHIBIT:
84 err = -EACCES;
85 goto errout;
86
87 case FR_ACT_BLACKHOLE:
88 default:
89 err = -EINVAL;
90 goto errout;
91 }
92
93 tbl = dn_fib_get_table(rule->table, 0);
94 if (tbl == NULL)
95 goto errout;
96
97 err = tbl->lookup(tbl, fld, (struct dn_fib_res *)arg->result);
98 if (err > 0)
99 err = -EAGAIN;
100 errout:
101 return err;
102 }
103
104 static const struct nla_policy dn_fib_rule_policy[FRA_MAX+1] = {
105 FRA_GENERIC_POLICY,
106 };
107
dn_fib_rule_match(struct fib_rule * rule,struct flowi * fl,int flags)108 static int dn_fib_rule_match(struct fib_rule *rule, struct flowi *fl, int flags)
109 {
110 struct dn_fib_rule *r = (struct dn_fib_rule *)rule;
111 struct flowidn *fld = &fl->u.dn;
112 __le16 daddr = fld->daddr;
113 __le16 saddr = fld->saddr;
114
115 if (((saddr ^ r->src) & r->srcmask) ||
116 ((daddr ^ r->dst) & r->dstmask))
117 return 0;
118
119 return 1;
120 }
121
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)122 static int dn_fib_rule_configure(struct fib_rule *rule, struct sk_buff *skb,
123 struct fib_rule_hdr *frh,
124 struct nlattr **tb,
125 struct netlink_ext_ack *extack)
126 {
127 int err = -EINVAL;
128 struct dn_fib_rule *r = (struct dn_fib_rule *)rule;
129
130 if (frh->tos) {
131 NL_SET_ERR_MSG(extack, "Invalid tos value");
132 goto errout;
133 }
134
135 if (rule->table == RT_TABLE_UNSPEC) {
136 if (rule->action == FR_ACT_TO_TBL) {
137 struct dn_fib_table *table;
138
139 table = dn_fib_empty_table();
140 if (table == NULL) {
141 err = -ENOBUFS;
142 goto errout;
143 }
144
145 rule->table = table->n;
146 }
147 }
148
149 if (frh->src_len)
150 r->src = nla_get_le16(tb[FRA_SRC]);
151
152 if (frh->dst_len)
153 r->dst = nla_get_le16(tb[FRA_DST]);
154
155 r->src_len = frh->src_len;
156 r->srcmask = dnet_make_mask(r->src_len);
157 r->dst_len = frh->dst_len;
158 r->dstmask = dnet_make_mask(r->dst_len);
159 err = 0;
160 errout:
161 return err;
162 }
163
dn_fib_rule_compare(struct fib_rule * rule,struct fib_rule_hdr * frh,struct nlattr ** tb)164 static int dn_fib_rule_compare(struct fib_rule *rule, struct fib_rule_hdr *frh,
165 struct nlattr **tb)
166 {
167 struct dn_fib_rule *r = (struct dn_fib_rule *)rule;
168
169 if (frh->src_len && (r->src_len != frh->src_len))
170 return 0;
171
172 if (frh->dst_len && (r->dst_len != frh->dst_len))
173 return 0;
174
175 if (frh->src_len && (r->src != nla_get_le16(tb[FRA_SRC])))
176 return 0;
177
178 if (frh->dst_len && (r->dst != nla_get_le16(tb[FRA_DST])))
179 return 0;
180
181 return 1;
182 }
183
dnet_addr_type(__le16 addr)184 unsigned int dnet_addr_type(__le16 addr)
185 {
186 struct flowidn fld = { .daddr = addr };
187 struct dn_fib_res res;
188 unsigned int ret = RTN_UNICAST;
189 struct dn_fib_table *tb = dn_fib_get_table(RT_TABLE_LOCAL, 0);
190
191 res.r = NULL;
192
193 if (tb) {
194 if (!tb->lookup(tb, &fld, &res)) {
195 ret = res.type;
196 dn_fib_res_put(&res);
197 }
198 }
199 return ret;
200 }
201
dn_fib_rule_fill(struct fib_rule * rule,struct sk_buff * skb,struct fib_rule_hdr * frh)202 static int dn_fib_rule_fill(struct fib_rule *rule, struct sk_buff *skb,
203 struct fib_rule_hdr *frh)
204 {
205 struct dn_fib_rule *r = (struct dn_fib_rule *)rule;
206
207 frh->dst_len = r->dst_len;
208 frh->src_len = r->src_len;
209 frh->tos = 0;
210
211 if ((r->dst_len &&
212 nla_put_le16(skb, FRA_DST, r->dst)) ||
213 (r->src_len &&
214 nla_put_le16(skb, FRA_SRC, r->src)))
215 goto nla_put_failure;
216 return 0;
217
218 nla_put_failure:
219 return -ENOBUFS;
220 }
221
dn_fib_rule_flush_cache(struct fib_rules_ops * ops)222 static void dn_fib_rule_flush_cache(struct fib_rules_ops *ops)
223 {
224 dn_rt_cache_flush(-1);
225 }
226
227 static const struct fib_rules_ops __net_initconst dn_fib_rules_ops_template = {
228 .family = AF_DECnet,
229 .rule_size = sizeof(struct dn_fib_rule),
230 .addr_size = sizeof(u16),
231 .action = dn_fib_rule_action,
232 .match = dn_fib_rule_match,
233 .configure = dn_fib_rule_configure,
234 .compare = dn_fib_rule_compare,
235 .fill = dn_fib_rule_fill,
236 .flush_cache = dn_fib_rule_flush_cache,
237 .nlgroup = RTNLGRP_DECnet_RULE,
238 .policy = dn_fib_rule_policy,
239 .owner = THIS_MODULE,
240 .fro_net = &init_net,
241 };
242
dn_fib_rules_init(void)243 void __init dn_fib_rules_init(void)
244 {
245 dn_fib_rules_ops =
246 fib_rules_register(&dn_fib_rules_ops_template, &init_net);
247 BUG_ON(IS_ERR(dn_fib_rules_ops));
248 BUG_ON(fib_default_rule_add(dn_fib_rules_ops, 0x7fff,
249 RT_TABLE_MAIN, 0));
250 }
251
dn_fib_rules_cleanup(void)252 void __exit dn_fib_rules_cleanup(void)
253 {
254 rtnl_lock();
255 fib_rules_unregister(dn_fib_rules_ops);
256 rtnl_unlock();
257 rcu_barrier();
258 }
259
