git.oblomov.eu Git - linux-2.6/blob - net/decnet/dn_rules.c

   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  *
  15  */
  16 #include <linux/string.h>
  17 #include <linux/net.h>
  18 #include <linux/socket.h>
  19 #include <linux/sockios.h>
  20 #include <linux/init.h>
  21 #include <linux/skbuff.h>
  22 #include <linux/netlink.h>
  23 #include <linux/rtnetlink.h>
  24 #include <linux/proc_fs.h>
  25 #include <linux/netdevice.h>
  26 #include <linux/timer.h>
  27 #include <linux/spinlock.h>
  28 #include <linux/in_route.h>
  29 #include <linux/list.h>
  30 #include <linux/rcupdate.h>
  31 #include <asm/atomic.h>
  32 #include <asm/uaccess.h>
  33 #include <net/neighbour.h>
  34 #include <net/dst.h>
  35 #include <net/flow.h>
  36 #include <net/dn.h>
  37 #include <net/dn_fib.h>
  38 #include <net/dn_neigh.h>
  39 #include <net/dn_dev.h>
  40
  41 struct dn_fib_rule
  42 {
  43         struct hlist_node       r_hlist;
  44         atomic_t                r_clntref;
  45         u32                     r_preference;
  46         unsigned char           r_table;
  47         unsigned char           r_action;
  48         unsigned char           r_dst_len;
  49         unsigned char           r_src_len;
  50         __le16                  r_src;
  51         __le16                  r_srcmask;
  52         __le16                  r_dst;
  53         __le16                  r_dstmask;
  54         __le16                  r_srcmap;
  55         u8                      r_flags;
  56 #ifdef CONFIG_DECNET_ROUTE_FWMARK
  57         u32                     r_fwmark;
  58 #endif
  59         int                     r_ifindex;
  60         char                    r_ifname[IFNAMSIZ];
  61         int                     r_dead;
  62         struct rcu_head         rcu;
  63 };
  64
  65 static struct dn_fib_rule default_rule = {
  66         .r_clntref =            ATOMIC_INIT(2),
  67         .r_preference =         0x7fff,
  68         .r_table =              RT_TABLE_MAIN,
  69         .r_action =             RTN_UNICAST
  70 };
  71
  72 static struct hlist_head dn_fib_rules;
  73
  74 int dn_fib_rtm_delrule(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg)
  75 {
  76         struct rtattr **rta = arg;
  77         struct rtmsg *rtm = NLMSG_DATA(nlh);
  78         struct dn_fib_rule *r;
  79         struct hlist_node *node;
  80         int err = -ESRCH;
  81
  82         hlist_for_each_entry(r, node, &dn_fib_rules, r_hlist) {
  83                 if ((!rta[RTA_SRC-1] || memcmp(RTA_DATA(rta[RTA_SRC-1]), &r->r_src, 2) == 0) &&
  84                         rtm->rtm_src_len == r->r_src_len &&
  85                         rtm->rtm_dst_len == r->r_dst_len &&
  86                         (!rta[RTA_DST-1] || memcmp(RTA_DATA(rta[RTA_DST-1]), &r->r_dst, 2) == 0) &&
  87 #ifdef CONFIG_DECNET_ROUTE_FWMARK
  88                         (!rta[RTA_PROTOINFO-1] || memcmp(RTA_DATA(rta[RTA_PROTOINFO-1]), &r->r_fwmark, 4) == 0) &&
  89 #endif
  90                         (!rtm->rtm_type || rtm->rtm_type == r->r_action) &&
  91                         (!rta[RTA_PRIORITY-1] || memcmp(RTA_DATA(rta[RTA_PRIORITY-1]), &r->r_preference, 4) == 0) &&
  92                         (!rta[RTA_IIF-1] || rtattr_strcmp(rta[RTA_IIF-1], r->r_ifname) == 0) &&
  93                         (!rtm->rtm_table || (r && rtm->rtm_table == r->r_table))) {
  94
  95                         err = -EPERM;
  96                         if (r == &default_rule)
  97                                 break;
  98
  99                         hlist_del_rcu(&r->r_hlist);
 100                         r->r_dead = 1;
 101                         dn_fib_rule_put(r);
 102                         err = 0;
 103                         break;
 104                 }
 105         }
 106
 107         return err;
 108 }
 109
 110 static inline void dn_fib_rule_put_rcu(struct rcu_head *head)
 111 {
 112         struct dn_fib_rule *r = container_of(head, struct dn_fib_rule, rcu);
 113         kfree(r);
 114 }
 115
 116 void dn_fib_rule_put(struct dn_fib_rule *r)
 117 {
 118         if (atomic_dec_and_test(&r->r_clntref)) {
 119                 if (r->r_dead)
 120                         call_rcu(&r->rcu, dn_fib_rule_put_rcu);
 121                 else
 122                         printk(KERN_DEBUG "Attempt to free alive dn_fib_rule\n");
 123         }
 124 }
 125
 126
 127 int dn_fib_rtm_newrule(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg)
 128 {
 129         struct rtattr **rta = arg;
 130         struct rtmsg *rtm = NLMSG_DATA(nlh);
 131         struct dn_fib_rule *r, *new_r, *last = NULL;
 132         struct hlist_node *node = NULL;
 133         unsigned char table_id;
 134
 135         if (rtm->rtm_src_len > 16 || rtm->rtm_dst_len > 16)
 136                 return -EINVAL;
 137
 138         if (rta[RTA_IIF-1] && RTA_PAYLOAD(rta[RTA_IIF-1]) > IFNAMSIZ)
 139                 return -EINVAL;
 140
 141         if (rtm->rtm_type == RTN_NAT)
 142                 return -EINVAL;
 143
 144         table_id = rtm->rtm_table;
 145         if (table_id == RT_TABLE_UNSPEC) {
 146                 struct dn_fib_table *tb;
 147                 if (rtm->rtm_type == RTN_UNICAST) {
 148                         if ((tb = dn_fib_empty_table()) == NULL)
 149                                 return -ENOBUFS;
 150                         table_id = tb->n;
 151                 }
 152         }
 153
 154         new_r = kmalloc(sizeof(*new_r), GFP_KERNEL);
 155         if (!new_r)
 156                 return -ENOMEM;
 157         memset(new_r, 0, sizeof(*new_r));
 158
 159         if (rta[RTA_SRC-1])
 160                 memcpy(&new_r->r_src, RTA_DATA(rta[RTA_SRC-1]), 2);
 161         if (rta[RTA_DST-1])
 162                 memcpy(&new_r->r_dst, RTA_DATA(rta[RTA_DST-1]), 2);
 163         if (rta[RTA_GATEWAY-1])
 164                 memcpy(&new_r->r_srcmap, RTA_DATA(rta[RTA_GATEWAY-1]), 2);
 165         new_r->r_src_len = rtm->rtm_src_len;
 166         new_r->r_dst_len = rtm->rtm_dst_len;
 167         new_r->r_srcmask = dnet_make_mask(rtm->rtm_src_len);
 168         new_r->r_dstmask = dnet_make_mask(rtm->rtm_dst_len);
 169 #ifdef CONFIG_DECNET_ROUTE_FWMARK
 170         if (rta[RTA_PROTOINFO-1])
 171                 memcpy(&new_r->r_fwmark, RTA_DATA(rta[RTA_PROTOINFO-1]), 4);
 172 #endif
 173         new_r->r_action = rtm->rtm_type;
 174         new_r->r_flags = rtm->rtm_flags;
 175         if (rta[RTA_PRIORITY-1])
 176                 memcpy(&new_r->r_preference, RTA_DATA(rta[RTA_PRIORITY-1]), 4);
 177         new_r->r_table = table_id;
 178         if (rta[RTA_IIF-1]) {
 179                 struct net_device *dev;
 180                 rtattr_strlcpy(new_r->r_ifname, rta[RTA_IIF-1], IFNAMSIZ);
 181                 new_r->r_ifindex = -1;
 182                 dev = dev_get_by_name(new_r->r_ifname);
 183                 if (dev) {
 184                         new_r->r_ifindex = dev->ifindex;
 185                         dev_put(dev);
 186                 }
 187         }
 188
 189         r = container_of(dn_fib_rules.first, struct dn_fib_rule, r_hlist);
 190         if (!new_r->r_preference) {
 191                 if (r && r->r_hlist.next != NULL) {
 192                         r = container_of(r->r_hlist.next, struct dn_fib_rule, r_hlist);
 193                         if (r->r_preference)
 194                                 new_r->r_preference = r->r_preference - 1;
 195                 }
 196         }
 197
 198         hlist_for_each_entry(r, node, &dn_fib_rules, r_hlist) {
 199                 if (r->r_preference > new_r->r_preference)
 200                         break;
 201                 last = r;
 202         }
 203         atomic_inc(&new_r->r_clntref);
 204
 205         if (last)
 206                 hlist_add_after_rcu(&last->r_hlist, &new_r->r_hlist);
 207         else
 208                 hlist_add_before_rcu(&new_r->r_hlist, &r->r_hlist);
 209         return 0;
 210 }
 211
 212
 213 int dn_fib_lookup(const struct flowi *flp, struct dn_fib_res *res)
 214 {
 215         struct dn_fib_rule *r, *policy;
 216         struct dn_fib_table *tb;
 217         __le16 saddr = flp->fld_src;
 218         __le16 daddr = flp->fld_dst;
 219         struct hlist_node *node;
 220         int err;
 221
 222         rcu_read_lock();
 223
 224         hlist_for_each_entry_rcu(r, node, &dn_fib_rules, r_hlist) {
 225                 if (((saddr^r->r_src) & r->r_srcmask) ||
 226                     ((daddr^r->r_dst) & r->r_dstmask) ||
 227 #ifdef CONFIG_DECNET_ROUTE_FWMARK
 228                     (r->r_fwmark && r->r_fwmark != flp->fld_fwmark) ||
 229 #endif
 230                     (r->r_ifindex && r->r_ifindex != flp->iif))
 231                         continue;
 232
 233                 switch(r->r_action) {
 234                         case RTN_UNICAST:
 235                         case RTN_NAT:
 236                                 policy = r;
 237                                 break;
 238                         case RTN_UNREACHABLE:
 239                                 rcu_read_unlock();
 240                                 return -ENETUNREACH;
 241                         default:
 242                         case RTN_BLACKHOLE:
 243                                 rcu_read_unlock();
 244                                 return -EINVAL;
 245                         case RTN_PROHIBIT:
 246                                 rcu_read_unlock();
 247                                 return -EACCES;
 248                 }
 249
 250                 if ((tb = dn_fib_get_table(r->r_table, 0)) == NULL)
 251                         continue;
 252                 err = tb->lookup(tb, flp, res);
 253                 if (err == 0) {
 254                         res->r = policy;
 255                         if (policy)
 256                                 atomic_inc(&policy->r_clntref);
 257                         rcu_read_unlock();
 258                         return 0;
 259                 }
 260                 if (err < 0 && err != -EAGAIN) {
 261                         rcu_read_unlock();
 262                         return err;
 263                 }
 264         }
 265
 266         rcu_read_unlock();
 267         return -ESRCH;
 268 }
 269
 270 unsigned dnet_addr_type(__le16 addr)
 271 {
 272         struct flowi fl = { .nl_u = { .dn_u = { .daddr = addr } } };
 273         struct dn_fib_res res;
 274         unsigned ret = RTN_UNICAST;
 275         struct dn_fib_table *tb = dn_fib_tables[RT_TABLE_LOCAL];
 276
 277         res.r = NULL;
 278
 279         if (tb) {
 280                 if (!tb->lookup(tb, &fl, &res)) {
 281                         ret = res.type;
 282                         dn_fib_res_put(&res);
 283                 }
 284         }
 285         return ret;
 286 }
 287
 288 __le16 dn_fib_rules_policy(__le16 saddr, struct dn_fib_res *res, unsigned *flags)
 289 {
 290         struct dn_fib_rule *r = res->r;
 291
 292         if (r->r_action == RTN_NAT) {
 293                 int addrtype = dnet_addr_type(r->r_srcmap);
 294
 295                 if (addrtype == RTN_NAT) {
 296                         saddr = (saddr&~r->r_srcmask)|r->r_srcmap;
 297                         *flags |= RTCF_SNAT;
 298                 } else if (addrtype == RTN_LOCAL || r->r_srcmap == 0) {
 299                         saddr = r->r_srcmap;
 300                         *flags |= RTCF_MASQ;
 301                 }
 302         }
 303         return saddr;
 304 }
 305
 306 static void dn_fib_rules_detach(struct net_device *dev)
 307 {
 308         struct hlist_node *node;
 309         struct dn_fib_rule *r;
 310
 311         hlist_for_each_entry(r, node, &dn_fib_rules, r_hlist) {
 312                 if (r->r_ifindex == dev->ifindex)
 313                         r->r_ifindex = -1;
 314         }
 315 }
 316
 317 static void dn_fib_rules_attach(struct net_device *dev)
 318 {
 319         struct hlist_node *node;
 320         struct dn_fib_rule *r;
 321
 322         hlist_for_each_entry(r, node, &dn_fib_rules, r_hlist) {
 323                 if (r->r_ifindex == -1 && strcmp(dev->name, r->r_ifname) == 0)
 324                         r->r_ifindex = dev->ifindex;
 325         }
 326 }
 327
 328 static int dn_fib_rules_event(struct notifier_block *this, unsigned long event, void *ptr)
 329 {
 330         struct net_device *dev = ptr;
 331
 332         switch(event) {
 333                 case NETDEV_UNREGISTER:
 334                         dn_fib_rules_detach(dev);
 335                         dn_fib_sync_down(0, dev, 1);
 336                 case NETDEV_REGISTER:
 337                         dn_fib_rules_attach(dev);
 338                         dn_fib_sync_up(dev);
 339         }
 340
 341         return NOTIFY_DONE;
 342 }
 343
 344
 345 static struct notifier_block dn_fib_rules_notifier = {
 346         .notifier_call =        dn_fib_rules_event,
 347 };
 348
 349 static int dn_fib_fill_rule(struct sk_buff *skb, struct dn_fib_rule *r,
 350                             struct netlink_callback *cb, unsigned int flags)
 351 {
 352         struct rtmsg *rtm;
 353         struct nlmsghdr *nlh;
 354         unsigned char *b = skb->tail;
 355
 356
 357         nlh = NLMSG_NEW_ANSWER(skb, cb, RTM_NEWRULE, sizeof(*rtm), flags);
 358         rtm = NLMSG_DATA(nlh);
 359         rtm->rtm_family = AF_DECnet;
 360         rtm->rtm_dst_len = r->r_dst_len;
 361         rtm->rtm_src_len = r->r_src_len;
 362         rtm->rtm_tos = 0;
 363 #ifdef CONFIG_DECNET_ROUTE_FWMARK
 364         if (r->r_fwmark)
 365                 RTA_PUT(skb, RTA_PROTOINFO, 4, &r->r_fwmark);
 366 #endif
 367         rtm->rtm_table = r->r_table;
 368         rtm->rtm_protocol = 0;
 369         rtm->rtm_scope = 0;
 370         rtm->rtm_type = r->r_action;
 371         rtm->rtm_flags = r->r_flags;
 372
 373         if (r->r_dst_len)
 374                 RTA_PUT(skb, RTA_DST, 2, &r->r_dst);
 375         if (r->r_src_len)
 376                 RTA_PUT(skb, RTA_SRC, 2, &r->r_src);
 377         if (r->r_ifname[0])
 378                 RTA_PUT(skb, RTA_IIF, IFNAMSIZ, &r->r_ifname);
 379         if (r->r_preference)
 380                 RTA_PUT(skb, RTA_PRIORITY, 4, &r->r_preference);
 381         if (r->r_srcmap)
 382                 RTA_PUT(skb, RTA_GATEWAY, 2, &r->r_srcmap);
 383         nlh->nlmsg_len = skb->tail - b;
 384         return skb->len;
 385
 386 nlmsg_failure:
 387 rtattr_failure:
 388         skb_trim(skb, b - skb->data);
 389         return -1;
 390 }
 391
 392 int dn_fib_dump_rules(struct sk_buff *skb, struct netlink_callback *cb)
 393 {
 394         int idx = 0;
 395         int s_idx = cb->args[0];
 396         struct dn_fib_rule *r;
 397         struct hlist_node *node;
 398
 399         rcu_read_lock();
 400         hlist_for_each_entry(r, node, &dn_fib_rules, r_hlist) {
 401                 if (idx < s_idx)
 402                         goto next;
 403                 if (dn_fib_fill_rule(skb, r, cb, NLM_F_MULTI) < 0)
 404                         break;
 405 next:
 406                 idx++;
 407         }
 408         rcu_read_unlock();
 409         cb->args[0] = idx;
 410
 411         return skb->len;
 412 }
 413
 414 void __init dn_fib_rules_init(void)
 415 {
 416         INIT_HLIST_HEAD(&dn_fib_rules);
 417         hlist_add_head(&default_rule.r_hlist, &dn_fib_rules);
 418         register_netdevice_notifier(&dn_fib_rules_notifier);
 419 }
 420
 421 void __exit dn_fib_rules_cleanup(void)
 422 {
 423         unregister_netdevice_notifier(&dn_fib_rules_notifier);
 424 }
 425
 426