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