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 36static struct fib_rules_ops dn_fib_rules_ops; 37 38struct 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 51static struct dn_fib_rule default_rule = { 52 .common = { 53 .refcnt = ATOMIC_INIT(2), 54 .pref = 0x7fff, 55 .table = RT_TABLE_MAIN, 56 .action = FR_ACT_TO_TBL, 57 }, 58}; 59 60static LIST_HEAD(dn_fib_rules); 61 62 63int dn_fib_lookup(struct flowi *flp, struct dn_fib_res *res) 64{ 65 struct fib_lookup_arg arg = { 66 .result = res, 67 }; 68 int err; 69 70 err = fib_rules_lookup(&dn_fib_rules_ops, flp, 0, &arg); 71 res->r = arg.rule; 72 73 return err; 74} 75 76static int dn_fib_rule_action(struct fib_rule *rule, struct flowi *flp, 77 int flags, struct fib_lookup_arg *arg) 78{ 79 int err = -EAGAIN; 80 struct dn_fib_table *tbl; 81 82 switch(rule->action) { 83 case FR_ACT_TO_TBL: 84 break; 85 86 case FR_ACT_UNREACHABLE: 87 err = -ENETUNREACH; 88 goto errout; 89 90 case FR_ACT_PROHIBIT: 91 err = -EACCES; 92 goto errout; 93 94 case FR_ACT_BLACKHOLE: 95 default: 96 err = -EINVAL; 97 goto errout; 98 } 99 100 tbl = dn_fib_get_table(rule->table, 0); 101 if (tbl == NULL) 102 goto errout; 103 104 err = tbl->lookup(tbl, flp, (struct dn_fib_res *)arg->result); 105 if (err > 0) 106 err = -EAGAIN; 107errout: 108 return err; 109} 110 111static const struct nla_policy dn_fib_rule_policy[FRA_MAX+1] = { 112 FRA_GENERIC_POLICY, 113}; 114 115static int dn_fib_rule_match(struct fib_rule *rule, struct flowi *fl, int flags) 116{ 117 struct dn_fib_rule *r = (struct dn_fib_rule *)rule; 118 __le16 daddr = fl->fld_dst; 119 __le16 saddr = fl->fld_src; 120 121 if (((saddr ^ r->src) & r->srcmask) || 122 ((daddr ^ r->dst) & r->dstmask)) 123 return 0; 124 125 return 1; 126} 127 128static int dn_fib_rule_configure(struct fib_rule *rule, struct sk_buff *skb, 129 struct nlmsghdr *nlh, struct fib_rule_hdr *frh, 130 struct nlattr **tb) 131{ 132 int err = -EINVAL; 133 struct dn_fib_rule *r = (struct dn_fib_rule *)rule; 134 135 if (frh->tos) 136 goto errout; 137 138 if (rule->table == RT_TABLE_UNSPEC) { 139 if (rule->action == FR_ACT_TO_TBL) { 140 struct dn_fib_table *table; 141 142 table = dn_fib_empty_table(); 143 if (table == NULL) { 144 err = -ENOBUFS; 145 goto errout; 146 } 147 148 rule->table = table->n; 149 } 150 } 151 152 if (frh->src_len) 153 r->src = nla_get_le16(tb[FRA_SRC]); 154 155 if (frh->dst_len) 156 r->dst = nla_get_le16(tb[FRA_DST]); 157 158 r->src_len = frh->src_len; 159 r->srcmask = dnet_make_mask(r->src_len); 160 r->dst_len = frh->dst_len; 161 r->dstmask = dnet_make_mask(r->dst_len); 162 err = 0; 163errout: 164 return err; 165} 166 167static int dn_fib_rule_compare(struct fib_rule *rule, struct fib_rule_hdr *frh, 168 struct nlattr **tb) 169{ 170 struct dn_fib_rule *r = (struct dn_fib_rule *)rule; 171 172 if (frh->src_len && (r->src_len != frh->src_len)) 173 return 0; 174 175 if (frh->dst_len && (r->dst_len != frh->dst_len)) 176 return 0; 177 178 if (frh->src_len && (r->src != nla_get_le16(tb[FRA_SRC]))) 179 return 0; 180 181 if (frh->dst_len && (r->dst != nla_get_le16(tb[FRA_DST]))) 182 return 0; 183 184 return 1; 185} 186 187unsigned dnet_addr_type(__le16 addr) 188{ 189 struct flowi fl = { .nl_u = { .dn_u = { .daddr = addr } } }; 190 struct dn_fib_res res; 191 unsigned ret = RTN_UNICAST; 192 struct dn_fib_table *tb = dn_fib_get_table(RT_TABLE_LOCAL, 0); 193 194 res.r = NULL; 195 196 if (tb) { 197 if (!tb->lookup(tb, &fl, &res)) { 198 ret = res.type; 199 dn_fib_res_put(&res); 200 } 201 } 202 return ret; 203} 204 205static int dn_fib_rule_fill(struct fib_rule *rule, struct sk_buff *skb, 206 struct nlmsghdr *nlh, struct fib_rule_hdr *frh) 207{ 208 struct dn_fib_rule *r = (struct dn_fib_rule *)rule; 209 210 frh->family = AF_DECnet; 211 frh->dst_len = r->dst_len; 212 frh->src_len = r->src_len; 213 frh->tos = 0; 214 215 if (r->dst_len) 216 NLA_PUT_LE16(skb, FRA_DST, r->dst); 217 if (r->src_len) 218 NLA_PUT_LE16(skb, FRA_SRC, r->src); 219 220 return 0; 221 222nla_put_failure: 223 return -ENOBUFS; 224} 225 226static u32 dn_fib_rule_default_pref(void) 227{ 228 struct list_head *pos; 229 struct fib_rule *rule; 230 231 if (!list_empty(&dn_fib_rules)) { 232 pos = dn_fib_rules.next; 233 if (pos->next != &dn_fib_rules) { 234 rule = list_entry(pos->next, struct fib_rule, list); 235 if (rule->pref) 236 return rule->pref - 1; 237 } 238 } 239 240 return 0; 241} 242 243static void dn_fib_rule_flush_cache(void) 244{ 245 dn_rt_cache_flush(-1); 246} 247 248static struct fib_rules_ops dn_fib_rules_ops = { 249 .family = AF_DECnet, 250 .rule_size = sizeof(struct dn_fib_rule), 251 .addr_size = sizeof(u16), 252 .action = dn_fib_rule_action, 253 .match = dn_fib_rule_match, 254 .configure = dn_fib_rule_configure, 255 .compare = dn_fib_rule_compare, 256 .fill = dn_fib_rule_fill, 257 .default_pref = dn_fib_rule_default_pref, 258 .flush_cache = dn_fib_rule_flush_cache, 259 .nlgroup = RTNLGRP_DECnet_RULE, 260 .policy = dn_fib_rule_policy, 261 .rules_list = &dn_fib_rules, 262 .owner = THIS_MODULE, 263}; 264 265void __init dn_fib_rules_init(void) 266{ 267 list_add_tail(&default_rule.common.list, &dn_fib_rules); 268 fib_rules_register(&dn_fib_rules_ops); 269} 270 271void __exit dn_fib_rules_cleanup(void) 272{ 273 fib_rules_unregister(&dn_fib_rules_ops); 274} 275