linux/net/decnet/dn_rules.c
<<
>>
Prefs
   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
 255