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 51 52int 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 65static 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; 96errout: 97 return err; 98} 99 100static const struct nla_policy dn_fib_rule_policy[FRA_MAX+1] = { 101 FRA_GENERIC_POLICY, 102}; 103 104static 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 117static int dn_fib_rule_configure(struct fib_rule *rule, struct sk_buff *skb, 118 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; 152errout: 153 return err; 154} 155 156static 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 176unsigned 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 194static int dn_fib_rule_fill(struct fib_rule *rule, struct sk_buff *skb, 195 struct fib_rule_hdr *frh) 196{ 197 struct dn_fib_rule *r = (struct dn_fib_rule *)rule; 198 199 frh->dst_len = r->dst_len; 200 frh->src_len = r->src_len; 201 frh->tos = 0; 202 203 if (r->dst_len) 204 NLA_PUT_LE16(skb, FRA_DST, r->dst); 205 if (r->src_len) 206 NLA_PUT_LE16(skb, FRA_SRC, r->src); 207 208 return 0; 209 210nla_put_failure: 211 return -ENOBUFS; 212} 213 214static void dn_fib_rule_flush_cache(struct fib_rules_ops *ops) 215{ 216 dn_rt_cache_flush(-1); 217} 218 219static const struct fib_rules_ops __net_initdata dn_fib_rules_ops_template = { 220 .family = AF_DECnet, 221 .rule_size = sizeof(struct dn_fib_rule), 222 .addr_size = sizeof(u16), 223 .action = dn_fib_rule_action, 224 .match = dn_fib_rule_match, 225 .configure = dn_fib_rule_configure, 226 .compare = dn_fib_rule_compare, 227 .fill = dn_fib_rule_fill, 228 .default_pref = fib_default_rule_pref, 229 .flush_cache = dn_fib_rule_flush_cache, 230 .nlgroup = RTNLGRP_DECnet_RULE, 231 .policy = dn_fib_rule_policy, 232 .owner = THIS_MODULE, 233 .fro_net = &init_net, 234}; 235 236void __init dn_fib_rules_init(void) 237{ 238 dn_fib_rules_ops = 239 fib_rules_register(&dn_fib_rules_ops_template, &init_net); 240 BUG_ON(IS_ERR(dn_fib_rules_ops)); 241 BUG_ON(fib_default_rule_add(dn_fib_rules_ops, 0x7fff, 242 RT_TABLE_MAIN, 0)); 243} 244 245void __exit dn_fib_rules_cleanup(void) 246{ 247 fib_rules_unregister(dn_fib_rules_ops); 248 rcu_barrier(); 249} 250