linux/net/decnet/dn_rules.c
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   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 nlmsghdr *nlh, 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 nlmsghdr *nlh, struct fib_rule_hdr *frh)
 196{
 197        struct dn_fib_rule *r = (struct dn_fib_rule *)rule;
 198
 199        frh->family = AF_DECnet;
 200        frh->dst_len = r->dst_len;
 201        frh->src_len = r->src_len;
 202        frh->tos = 0;
 203
 204        if (r->dst_len)
 205                NLA_PUT_LE16(skb, FRA_DST, r->dst);
 206        if (r->src_len)
 207                NLA_PUT_LE16(skb, FRA_SRC, r->src);
 208
 209        return 0;
 210
 211nla_put_failure:
 212        return -ENOBUFS;
 213}
 214
 215static u32 dn_fib_rule_default_pref(struct fib_rules_ops *ops)
 216{
 217        struct list_head *pos;
 218        struct fib_rule *rule;
 219
 220        if (!list_empty(&dn_fib_rules_ops.rules_list)) {
 221                pos = dn_fib_rules_ops.rules_list.next;
 222                if (pos->next != &dn_fib_rules_ops.rules_list) {
 223                        rule = list_entry(pos->next, struct fib_rule, list);
 224                        if (rule->pref)
 225                                return rule->pref - 1;
 226                }
 227        }
 228
 229        return 0;
 230}
 231
 232static void dn_fib_rule_flush_cache(struct fib_rules_ops *ops)
 233{
 234        dn_rt_cache_flush(-1);
 235}
 236
 237static struct fib_rules_ops dn_fib_rules_ops = {
 238        .family         = AF_DECnet,
 239        .rule_size      = sizeof(struct dn_fib_rule),
 240        .addr_size      = sizeof(u16),
 241        .action         = dn_fib_rule_action,
 242        .match          = dn_fib_rule_match,
 243        .configure      = dn_fib_rule_configure,
 244        .compare        = dn_fib_rule_compare,
 245        .fill           = dn_fib_rule_fill,
 246        .default_pref   = dn_fib_rule_default_pref,
 247        .flush_cache    = dn_fib_rule_flush_cache,
 248        .nlgroup        = RTNLGRP_DECnet_RULE,
 249        .policy         = dn_fib_rule_policy,
 250        .rules_list     = LIST_HEAD_INIT(dn_fib_rules_ops.rules_list),
 251        .owner          = THIS_MODULE,
 252        .fro_net        = &init_net,
 253};
 254
 255void __init dn_fib_rules_init(void)
 256{
 257        BUG_ON(fib_default_rule_add(&dn_fib_rules_ops, 0x7fff,
 258                                    RT_TABLE_MAIN, 0));
 259        fib_rules_register(&dn_fib_rules_ops);
 260}
 261
 262void __exit dn_fib_rules_cleanup(void)
 263{
 264        fib_rules_unregister(&dn_fib_rules_ops);
 265}
 266
 267
 268