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 <net/neighbour.h>
27 #include <net/dst.h>
28 #include <net/flow.h>
29 #include <net/fib_rules.h>
30 #include <net/dn.h>
31 #include <net/dn_fib.h>
32 #include <net/dn_neigh.h>
33 #include <net/dn_dev.h>
34 #include <net/dn_route.h>
35
36 static struct fib_rules_ops dn_fib_rules_ops;
37
38 struct dn_fib_rule
39 {
40 struct fib_rule common;
41 unsigned char dst_len;
42 unsigned char src_len;
43 __le16 src;
44 __le16 srcmask;
45 __le16 dst;
46 __le16 dstmask;
47 __le16 srcmap;
48 u8 flags;
49 };
50
51
dn_fib_lookup(struct flowi * flp,struct dn_fib_res * res)52 int dn_fib_lookup(struct flowi *flp, struct dn_fib_res *res)
53 {
54 struct fib_lookup_arg arg = {
55 .result = res,
56 };
57 int err;
58
59 err = fib_rules_lookup(&dn_fib_rules_ops, flp, 0, &arg);
60 res->r = arg.rule;
61
62 return err;
63 }
64
dn_fib_rule_action(struct fib_rule * rule,struct flowi * flp,int flags,struct fib_lookup_arg * arg)65 static int dn_fib_rule_action(struct fib_rule *rule, struct flowi *flp,
66 int flags, struct fib_lookup_arg *arg)
67 {
68 int err = -EAGAIN;
69 struct dn_fib_table *tbl;
70
71 switch(rule->action) {
72 case FR_ACT_TO_TBL:
73 break;
74
75 case FR_ACT_UNREACHABLE:
76 err = -ENETUNREACH;
77 goto errout;
78
79 case FR_ACT_PROHIBIT:
80 err = -EACCES;
81 goto errout;
82
83 case FR_ACT_BLACKHOLE:
84 default:
85 err = -EINVAL;
86 goto errout;
87 }
88
89 tbl = dn_fib_get_table(rule->table, 0);
90 if (tbl == NULL)
91 goto errout;
92
93 err = tbl->lookup(tbl, flp, (struct dn_fib_res *)arg->result);
94 if (err > 0)
95 err = -EAGAIN;
96 errout:
97 return err;
98 }
99
100 static const struct nla_policy dn_fib_rule_policy[FRA_MAX+1] = {
101 FRA_GENERIC_POLICY,
102 };
103
dn_fib_rule_match(struct fib_rule * rule,struct flowi * fl,int flags)104 static int dn_fib_rule_match(struct fib_rule *rule, struct flowi *fl, int flags)
105 {
106 struct dn_fib_rule *r = (struct dn_fib_rule *)rule;
107 __le16 daddr = fl->fld_dst;
108 __le16 saddr = fl->fld_src;
109
110 if (((saddr ^ r->src) & r->srcmask) ||
111 ((daddr ^ r->dst) & r->dstmask))
112 return 0;
113
114 return 1;
115 }
116
dn_fib_rule_configure(struct fib_rule * rule,struct sk_buff * skb,struct nlmsghdr * nlh,struct fib_rule_hdr * frh,struct nlattr ** tb)117 static int dn_fib_rule_configure(struct fib_rule *rule, struct sk_buff *skb,
118 struct nlmsghdr *nlh, struct fib_rule_hdr *frh,
119 struct nlattr **tb)
120 {
121 int err = -EINVAL;
122 struct dn_fib_rule *r = (struct dn_fib_rule *)rule;
123
124 if (frh->tos)
125 goto errout;
126
127 if (rule->table == RT_TABLE_UNSPEC) {
128 if (rule->action == FR_ACT_TO_TBL) {
129 struct dn_fib_table *table;
130
131 table = dn_fib_empty_table();
132 if (table == NULL) {
133 err = -ENOBUFS;
134 goto errout;
135 }
136
137 rule->table = table->n;
138 }
139 }
140
141 if (frh->src_len)
142 r->src = nla_get_le16(tb[FRA_SRC]);
143
144 if (frh->dst_len)
145 r->dst = nla_get_le16(tb[FRA_DST]);
146
147 r->src_len = frh->src_len;
148 r->srcmask = dnet_make_mask(r->src_len);
149 r->dst_len = frh->dst_len;
150 r->dstmask = dnet_make_mask(r->dst_len);
151 err = 0;
152 errout:
153 return err;
154 }
155
dn_fib_rule_compare(struct fib_rule * rule,struct fib_rule_hdr * frh,struct nlattr ** tb)156 static int dn_fib_rule_compare(struct fib_rule *rule, struct fib_rule_hdr *frh,
157 struct nlattr **tb)
158 {
159 struct dn_fib_rule *r = (struct dn_fib_rule *)rule;
160
161 if (frh->src_len && (r->src_len != frh->src_len))
162 return 0;
163
164 if (frh->dst_len && (r->dst_len != frh->dst_len))
165 return 0;
166
167 if (frh->src_len && (r->src != nla_get_le16(tb[FRA_SRC])))
168 return 0;
169
170 if (frh->dst_len && (r->dst != nla_get_le16(tb[FRA_DST])))
171 return 0;
172
173 return 1;
174 }
175
dnet_addr_type(__le16 addr)176 unsigned dnet_addr_type(__le16 addr)
177 {
178 struct flowi fl = { .nl_u = { .dn_u = { .daddr = addr } } };
179 struct dn_fib_res res;
180 unsigned ret = RTN_UNICAST;
181 struct dn_fib_table *tb = dn_fib_get_table(RT_TABLE_LOCAL, 0);
182
183 res.r = NULL;
184
185 if (tb) {
186 if (!tb->lookup(tb, &fl, &res)) {
187 ret = res.type;
188 dn_fib_res_put(&res);
189 }
190 }
191 return ret;
192 }
193
dn_fib_rule_fill(struct fib_rule * rule,struct sk_buff * skb,struct nlmsghdr * nlh,struct fib_rule_hdr * frh)194 static int dn_fib_rule_fill(struct fib_rule *rule, struct sk_buff *skb,
195 struct nlmsghdr *nlh, struct fib_rule_hdr *frh)
196 {
197 struct dn_fib_rule *r = (struct dn_fib_rule *)rule;
198
199 frh->family = AF_DECnet;
200 frh->dst_len = r->dst_len;
201 frh->src_len = r->src_len;
202 frh->tos = 0;
203
204 if (r->dst_len)
205 NLA_PUT_LE16(skb, FRA_DST, r->dst);
206 if (r->src_len)
207 NLA_PUT_LE16(skb, FRA_SRC, r->src);
208
209 return 0;
210
211 nla_put_failure:
212 return -ENOBUFS;
213 }
214
dn_fib_rule_default_pref(struct fib_rules_ops * ops)215 static u32 dn_fib_rule_default_pref(struct fib_rules_ops *ops)
216 {
217 struct list_head *pos;
218 struct fib_rule *rule;
219
220 if (!list_empty(&dn_fib_rules_ops.rules_list)) {
221 pos = dn_fib_rules_ops.rules_list.next;
222 if (pos->next != &dn_fib_rules_ops.rules_list) {
223 rule = list_entry(pos->next, struct fib_rule, list);
224 if (rule->pref)
225 return rule->pref - 1;
226 }
227 }
228
229 return 0;
230 }
231
dn_fib_rule_flush_cache(struct fib_rules_ops * ops)232 static void dn_fib_rule_flush_cache(struct fib_rules_ops *ops)
233 {
234 dn_rt_cache_flush(-1);
235 }
236
237 static struct fib_rules_ops dn_fib_rules_ops = {
238 .family = AF_DECnet,
239 .rule_size = sizeof(struct dn_fib_rule),
240 .addr_size = sizeof(u16),
241 .action = dn_fib_rule_action,
242 .match = dn_fib_rule_match,
243 .configure = dn_fib_rule_configure,
244 .compare = dn_fib_rule_compare,
245 .fill = dn_fib_rule_fill,
246 .default_pref = dn_fib_rule_default_pref,
247 .flush_cache = dn_fib_rule_flush_cache,
248 .nlgroup = RTNLGRP_DECnet_RULE,
249 .policy = dn_fib_rule_policy,
250 .rules_list = LIST_HEAD_INIT(dn_fib_rules_ops.rules_list),
251 .owner = THIS_MODULE,
252 .fro_net = &init_net,
253 };
254
dn_fib_rules_init(void)255 void __init dn_fib_rules_init(void)
256 {
257 BUG_ON(fib_default_rule_add(&dn_fib_rules_ops, 0x7fff,
258 RT_TABLE_MAIN, 0));
259 fib_rules_register(&dn_fib_rules_ops);
260 }
261
dn_fib_rules_cleanup(void)262 void __exit dn_fib_rules_cleanup(void)
263 {
264 fib_rules_unregister(&dn_fib_rules_ops);
265 }
266
267
268