| 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 | |
| 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 | |
| 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 | |
| 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 | |
| 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 | { |
| 126 | int err = -EINVAL; |
| 127 | struct dn_fib_rule *r = (struct dn_fib_rule *)rule; |
| 128 | |
| 129 | if (frh->tos) |
| 130 | goto errout; |
| 131 | |
| 132 | if (rule->table == RT_TABLE_UNSPEC) { |
| 133 | if (rule->action == FR_ACT_TO_TBL) { |
| 134 | struct dn_fib_table *table; |
| 135 | |
| 136 | table = dn_fib_empty_table(); |
| 137 | if (table == NULL) { |
| 138 | err = -ENOBUFS; |
| 139 | goto errout; |
| 140 | } |
| 141 | |
| 142 | rule->table = table->n; |
| 143 | } |
| 144 | } |
| 145 | |
| 146 | if (frh->src_len) |
| 147 | r->src = nla_get_le16(tb[FRA_SRC]); |
| 148 | |
| 149 | if (frh->dst_len) |
| 150 | r->dst = nla_get_le16(tb[FRA_DST]); |
| 151 | |
| 152 | r->src_len = frh->src_len; |
| 153 | r->srcmask = dnet_make_mask(r->src_len); |
| 154 | r->dst_len = frh->dst_len; |
| 155 | r->dstmask = dnet_make_mask(r->dst_len); |
| 156 | err = 0; |
| 157 | errout: |
| 158 | return err; |
| 159 | } |
| 160 | |
| 161 | static int dn_fib_rule_compare(struct fib_rule *rule, struct fib_rule_hdr *frh, |
| 162 | struct nlattr **tb) |
| 163 | { |
| 164 | struct dn_fib_rule *r = (struct dn_fib_rule *)rule; |
| 165 | |
| 166 | if (frh->src_len && (r->src_len != frh->src_len)) |
| 167 | return 0; |
| 168 | |
| 169 | if (frh->dst_len && (r->dst_len != frh->dst_len)) |
| 170 | return 0; |
| 171 | |
| 172 | if (frh->src_len && (r->src != nla_get_le16(tb[FRA_SRC]))) |
| 173 | return 0; |
| 174 | |
| 175 | if (frh->dst_len && (r->dst != nla_get_le16(tb[FRA_DST]))) |
| 176 | return 0; |
| 177 | |
| 178 | return 1; |
| 179 | } |
| 180 | |
| 181 | unsigned int dnet_addr_type(__le16 addr) |
| 182 | { |
| 183 | struct flowidn fld = { .daddr = addr }; |
| 184 | struct dn_fib_res res; |
| 185 | unsigned int ret = RTN_UNICAST; |
| 186 | struct dn_fib_table *tb = dn_fib_get_table(RT_TABLE_LOCAL, 0); |
| 187 | |
| 188 | res.r = NULL; |
| 189 | |
| 190 | if (tb) { |
| 191 | if (!tb->lookup(tb, &fld, &res)) { |
| 192 | ret = res.type; |
| 193 | dn_fib_res_put(&res); |
| 194 | } |
| 195 | } |
| 196 | return ret; |
| 197 | } |
| 198 | |
| 199 | static int dn_fib_rule_fill(struct fib_rule *rule, struct sk_buff *skb, |
| 200 | struct fib_rule_hdr *frh) |
| 201 | { |
| 202 | struct dn_fib_rule *r = (struct dn_fib_rule *)rule; |
| 203 | |
| 204 | frh->dst_len = r->dst_len; |
| 205 | frh->src_len = r->src_len; |
| 206 | frh->tos = 0; |
| 207 | |
| 208 | if ((r->dst_len && |
| 209 | nla_put_le16(skb, FRA_DST, r->dst)) || |
| 210 | (r->src_len && |
| 211 | nla_put_le16(skb, FRA_SRC, r->src))) |
| 212 | goto nla_put_failure; |
| 213 | return 0; |
| 214 | |
| 215 | nla_put_failure: |
| 216 | return -ENOBUFS; |
| 217 | } |
| 218 | |
| 219 | static void dn_fib_rule_flush_cache(struct fib_rules_ops *ops) |
| 220 | { |
| 221 | dn_rt_cache_flush(-1); |
| 222 | } |
| 223 | |
| 224 | static const struct fib_rules_ops __net_initconst dn_fib_rules_ops_template = { |
| 225 | .family = AF_DECnet, |
| 226 | .rule_size = sizeof(struct dn_fib_rule), |
| 227 | .addr_size = sizeof(u16), |
| 228 | .action = dn_fib_rule_action, |
| 229 | .match = dn_fib_rule_match, |
| 230 | .configure = dn_fib_rule_configure, |
| 231 | .compare = dn_fib_rule_compare, |
| 232 | .fill = dn_fib_rule_fill, |
| 233 | .flush_cache = dn_fib_rule_flush_cache, |
| 234 | .nlgroup = RTNLGRP_DECnet_RULE, |
| 235 | .policy = dn_fib_rule_policy, |
| 236 | .owner = THIS_MODULE, |
| 237 | .fro_net = &init_net, |
| 238 | }; |
| 239 | |
| 240 | void __init dn_fib_rules_init(void) |
| 241 | { |
| 242 | dn_fib_rules_ops = |
| 243 | fib_rules_register(&dn_fib_rules_ops_template, &init_net); |
| 244 | BUG_ON(IS_ERR(dn_fib_rules_ops)); |
| 245 | BUG_ON(fib_default_rule_add(dn_fib_rules_ops, 0x7fff, |
| 246 | RT_TABLE_MAIN, 0)); |
| 247 | } |
| 248 | |
| 249 | void __exit dn_fib_rules_cleanup(void) |
| 250 | { |
| 251 | rtnl_lock(); |
| 252 | fib_rules_unregister(dn_fib_rules_ops); |
| 253 | rtnl_unlock(); |
| 254 | rcu_barrier(); |
| 255 | } |
| 256 | |
| 257 | |