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