at v3.0-rc3 254 lines 5.5 kB view raw
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 flowidn *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, 60 flowidn_to_flowi(flp), 0, &arg); 61 res->r = arg.rule; 62 63 return err; 64} 65 66static int dn_fib_rule_action(struct fib_rule *rule, struct flowi *flp, 67 int flags, struct fib_lookup_arg *arg) 68{ 69 struct flowidn *fld = &flp->u.dn; 70 int err = -EAGAIN; 71 struct dn_fib_table *tbl; 72 73 switch(rule->action) { 74 case FR_ACT_TO_TBL: 75 break; 76 77 case FR_ACT_UNREACHABLE: 78 err = -ENETUNREACH; 79 goto errout; 80 81 case FR_ACT_PROHIBIT: 82 err = -EACCES; 83 goto errout; 84 85 case FR_ACT_BLACKHOLE: 86 default: 87 err = -EINVAL; 88 goto errout; 89 } 90 91 tbl = dn_fib_get_table(rule->table, 0); 92 if (tbl == NULL) 93 goto errout; 94 95 err = tbl->lookup(tbl, fld, (struct dn_fib_res *)arg->result); 96 if (err > 0) 97 err = -EAGAIN; 98errout: 99 return err; 100} 101 102static const struct nla_policy dn_fib_rule_policy[FRA_MAX+1] = { 103 FRA_GENERIC_POLICY, 104}; 105 106static int dn_fib_rule_match(struct fib_rule *rule, struct flowi *fl, int flags) 107{ 108 struct dn_fib_rule *r = (struct dn_fib_rule *)rule; 109 struct flowidn *fld = &fl->u.dn; 110 __le16 daddr = fld->daddr; 111 __le16 saddr = fld->saddr; 112 113 if (((saddr ^ r->src) & r->srcmask) || 114 ((daddr ^ r->dst) & r->dstmask)) 115 return 0; 116 117 return 1; 118} 119 120static int dn_fib_rule_configure(struct fib_rule *rule, struct sk_buff *skb, 121 struct fib_rule_hdr *frh, 122 struct nlattr **tb) 123{ 124 int err = -EINVAL; 125 struct dn_fib_rule *r = (struct dn_fib_rule *)rule; 126 127 if (frh->tos) 128 goto errout; 129 130 if (rule->table == RT_TABLE_UNSPEC) { 131 if (rule->action == FR_ACT_TO_TBL) { 132 struct dn_fib_table *table; 133 134 table = dn_fib_empty_table(); 135 if (table == NULL) { 136 err = -ENOBUFS; 137 goto errout; 138 } 139 140 rule->table = table->n; 141 } 142 } 143 144 if (frh->src_len) 145 r->src = nla_get_le16(tb[FRA_SRC]); 146 147 if (frh->dst_len) 148 r->dst = nla_get_le16(tb[FRA_DST]); 149 150 r->src_len = frh->src_len; 151 r->srcmask = dnet_make_mask(r->src_len); 152 r->dst_len = frh->dst_len; 153 r->dstmask = dnet_make_mask(r->dst_len); 154 err = 0; 155errout: 156 return err; 157} 158 159static int dn_fib_rule_compare(struct fib_rule *rule, struct fib_rule_hdr *frh, 160 struct nlattr **tb) 161{ 162 struct dn_fib_rule *r = (struct dn_fib_rule *)rule; 163 164 if (frh->src_len && (r->src_len != frh->src_len)) 165 return 0; 166 167 if (frh->dst_len && (r->dst_len != frh->dst_len)) 168 return 0; 169 170 if (frh->src_len && (r->src != nla_get_le16(tb[FRA_SRC]))) 171 return 0; 172 173 if (frh->dst_len && (r->dst != nla_get_le16(tb[FRA_DST]))) 174 return 0; 175 176 return 1; 177} 178 179unsigned dnet_addr_type(__le16 addr) 180{ 181 struct flowidn fld = { .daddr = addr }; 182 struct dn_fib_res res; 183 unsigned ret = RTN_UNICAST; 184 struct dn_fib_table *tb = dn_fib_get_table(RT_TABLE_LOCAL, 0); 185 186 res.r = NULL; 187 188 if (tb) { 189 if (!tb->lookup(tb, &fld, &res)) { 190 ret = res.type; 191 dn_fib_res_put(&res); 192 } 193 } 194 return ret; 195} 196 197static int dn_fib_rule_fill(struct fib_rule *rule, struct sk_buff *skb, 198 struct fib_rule_hdr *frh) 199{ 200 struct dn_fib_rule *r = (struct dn_fib_rule *)rule; 201 202 frh->dst_len = r->dst_len; 203 frh->src_len = r->src_len; 204 frh->tos = 0; 205 206 if (r->dst_len) 207 NLA_PUT_LE16(skb, FRA_DST, r->dst); 208 if (r->src_len) 209 NLA_PUT_LE16(skb, FRA_SRC, r->src); 210 211 return 0; 212 213nla_put_failure: 214 return -ENOBUFS; 215} 216 217static void dn_fib_rule_flush_cache(struct fib_rules_ops *ops) 218{ 219 dn_rt_cache_flush(-1); 220} 221 222static const struct fib_rules_ops __net_initdata dn_fib_rules_ops_template = { 223 .family = AF_DECnet, 224 .rule_size = sizeof(struct dn_fib_rule), 225 .addr_size = sizeof(u16), 226 .action = dn_fib_rule_action, 227 .match = dn_fib_rule_match, 228 .configure = dn_fib_rule_configure, 229 .compare = dn_fib_rule_compare, 230 .fill = dn_fib_rule_fill, 231 .default_pref = fib_default_rule_pref, 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 239void __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 248void __exit dn_fib_rules_cleanup(void) 249{ 250 fib_rules_unregister(dn_fib_rules_ops); 251 rcu_barrier(); 252} 253 254