2 * DECnet An implementation of the DECnet protocol suite for the LINUX
3 * operating system. DECnet is implemented using the BSD Socket
4 * interface as the means of communication with the user level.
6 * DECnet Neighbour Functions (Adjacency Database and
9 * Author: Steve Whitehouse <SteveW@ACM.org>
13 * Steve Whitehouse : Fixed router listing routine
14 * Steve Whitehouse : Added error_report functions
15 * Steve Whitehouse : Added default router detection
16 * Steve Whitehouse : Hop counts in outgoing messages
17 * Steve Whitehouse : Fixed src/dst in outgoing messages so
18 * forwarding now stands a good chance of
20 * Steve Whitehouse : Fixed neighbour states (for now anyway).
21 * Steve Whitehouse : Made error_report functions dummies. This
22 * is not the right place to return skbs.
23 * Steve Whitehouse : Convert to seq_file
27 #include <linux/net.h>
28 #include <linux/module.h>
29 #include <linux/socket.h>
30 #include <linux/if_arp.h>
31 #include <linux/slab.h>
32 #include <linux/if_ether.h>
33 #include <linux/init.h>
34 #include <linux/proc_fs.h>
35 #include <linux/string.h>
36 #include <linux/netfilter_decnet.h>
37 #include <linux/spinlock.h>
38 #include <linux/seq_file.h>
39 #include <linux/rcupdate.h>
40 #include <linux/jhash.h>
41 #include <linux/atomic.h>
42 #include <net/net_namespace.h>
43 #include <net/neighbour.h>
47 #include <net/dn_dev.h>
48 #include <net/dn_neigh.h>
49 #include <net/dn_route.h>
51 static int dn_neigh_construct(struct neighbour *);
52 static void dn_long_error_report(struct neighbour *, struct sk_buff *);
53 static void dn_short_error_report(struct neighbour *, struct sk_buff *);
54 static int dn_long_output(struct neighbour *, struct sk_buff *);
55 static int dn_short_output(struct neighbour *, struct sk_buff *);
56 static int dn_phase3_output(struct neighbour *, struct sk_buff *);
60 * For talking to broadcast devices: Ethernet & PPP
62 static const struct neigh_ops dn_long_ops = {
64 .error_report = dn_long_error_report,
65 .output = dn_long_output,
66 .connected_output = dn_long_output,
70 * For talking to pointopoint and multidrop devices: DDCMP and X.25
72 static const struct neigh_ops dn_short_ops = {
74 .error_report = dn_short_error_report,
75 .output = dn_short_output,
76 .connected_output = dn_short_output,
80 * For talking to DECnet phase III nodes
82 static const struct neigh_ops dn_phase3_ops = {
84 .error_report = dn_short_error_report, /* Can use short version here */
85 .output = dn_phase3_output,
86 .connected_output = dn_phase3_output,
89 static u32 dn_neigh_hash(const void *pkey,
90 const struct net_device *dev,
93 return jhash_2words(*(__u16 *)pkey, 0, hash_rnd[0]);
96 static bool dn_key_eq(const struct neighbour *neigh, const void *pkey)
98 return neigh_key_eq16(neigh, pkey);
101 struct neigh_table dn_neigh_table = {
103 .entry_size = NEIGH_ENTRY_SIZE(sizeof(struct dn_neigh)),
104 .key_len = sizeof(__le16),
105 .protocol = cpu_to_be16(ETH_P_DNA_RT),
106 .hash = dn_neigh_hash,
108 .constructor = dn_neigh_construct,
109 .id = "dn_neigh_cache",
111 .tbl = &dn_neigh_table,
112 .reachable_time = 30 * HZ,
114 [NEIGH_VAR_MCAST_PROBES] = 0,
115 [NEIGH_VAR_UCAST_PROBES] = 0,
116 [NEIGH_VAR_APP_PROBES] = 0,
117 [NEIGH_VAR_RETRANS_TIME] = 1 * HZ,
118 [NEIGH_VAR_BASE_REACHABLE_TIME] = 30 * HZ,
119 [NEIGH_VAR_DELAY_PROBE_TIME] = 5 * HZ,
120 [NEIGH_VAR_GC_STALETIME] = 60 * HZ,
121 [NEIGH_VAR_QUEUE_LEN_BYTES] = 64*1024,
122 [NEIGH_VAR_PROXY_QLEN] = 0,
123 [NEIGH_VAR_ANYCAST_DELAY] = 0,
124 [NEIGH_VAR_PROXY_DELAY] = 0,
125 [NEIGH_VAR_LOCKTIME] = 1 * HZ,
128 .gc_interval = 30 * HZ,
134 static int dn_neigh_construct(struct neighbour *neigh)
136 struct net_device *dev = neigh->dev;
137 struct dn_neigh *dn = (struct dn_neigh *)neigh;
138 struct dn_dev *dn_db;
139 struct neigh_parms *parms;
142 dn_db = rcu_dereference(dev->dn_ptr);
148 parms = dn_db->neigh_parms;
154 __neigh_parms_put(neigh->parms);
155 neigh->parms = neigh_parms_clone(parms);
158 neigh->ops = &dn_long_ops;
160 neigh->ops = &dn_short_ops;
163 if (dn->flags & DN_NDFLAG_P3)
164 neigh->ops = &dn_phase3_ops;
166 neigh->nud_state = NUD_NOARP;
167 neigh->output = neigh->ops->connected_output;
169 if ((dev->type == ARPHRD_IPGRE) || (dev->flags & IFF_POINTOPOINT))
170 memcpy(neigh->ha, dev->broadcast, dev->addr_len);
171 else if ((dev->type == ARPHRD_ETHER) || (dev->type == ARPHRD_LOOPBACK))
172 dn_dn2eth(neigh->ha, dn->addr);
174 net_dbg_ratelimited("Trying to create neigh for hw %d\n",
180 * Make an estimate of the remote block size by assuming that its
181 * two less then the device mtu, which it true for ethernet (and
182 * other things which support long format headers) since there is
183 * an extra length field (of 16 bits) which isn't part of the
184 * ethernet headers and which the DECnet specs won't admit is part
185 * of the DECnet routing headers either.
187 * If we over estimate here its no big deal, the NSP negotiations
188 * will prevent us from sending packets which are too large for the
189 * remote node to handle. In any case this figure is normally updated
190 * by a hello message in most cases.
192 dn->blksize = dev->mtu - 2;
197 static void dn_long_error_report(struct neighbour *neigh, struct sk_buff *skb)
199 printk(KERN_DEBUG "dn_long_error_report: called\n");
204 static void dn_short_error_report(struct neighbour *neigh, struct sk_buff *skb)
206 printk(KERN_DEBUG "dn_short_error_report: called\n");
210 static int dn_neigh_output_packet(struct sk_buff *skb)
212 struct dst_entry *dst = skb_dst(skb);
213 struct dn_route *rt = (struct dn_route *)dst;
214 struct neighbour *neigh = rt->n;
215 struct net_device *dev = neigh->dev;
216 char mac_addr[ETH_ALEN];
220 dn_dn2eth(mac_addr, rt->rt_local_src);
222 seq = read_seqbegin(&neigh->ha_lock);
223 err = dev_hard_header(skb, dev, ntohs(skb->protocol),
224 neigh->ha, mac_addr, skb->len);
225 } while (read_seqretry(&neigh->ha_lock, seq));
228 err = dev_queue_xmit(skb);
236 static int dn_long_output(struct neighbour *neigh, struct sk_buff *skb)
238 struct net_device *dev = neigh->dev;
239 int headroom = dev->hard_header_len + sizeof(struct dn_long_packet) + 3;
241 struct dn_long_packet *lp;
242 struct dn_skb_cb *cb = DN_SKB_CB(skb);
245 if (skb_headroom(skb) < headroom) {
246 struct sk_buff *skb2 = skb_realloc_headroom(skb, headroom);
248 net_crit_ratelimited("dn_long_output: no memory\n");
254 net_info_ratelimited("dn_long_output: Increasing headroom\n");
257 data = skb_push(skb, sizeof(struct dn_long_packet) + 3);
258 lp = (struct dn_long_packet *)(data+3);
260 *((__le16 *)data) = cpu_to_le16(skb->len - 2);
261 *(data + 2) = 1 | DN_RT_F_PF; /* Padding */
263 lp->msgflg = DN_RT_PKT_LONG|(cb->rt_flags&(DN_RT_F_IE|DN_RT_F_RQR|DN_RT_F_RTS));
264 lp->d_area = lp->d_subarea = 0;
265 dn_dn2eth(lp->d_id, cb->dst);
266 lp->s_area = lp->s_subarea = 0;
267 dn_dn2eth(lp->s_id, cb->src);
269 lp->visit_ct = cb->hops & 0x3f;
273 skb_reset_network_header(skb);
275 return NF_HOOK(NFPROTO_DECNET, NF_DN_POST_ROUTING, skb, NULL,
276 neigh->dev, dn_neigh_output_packet);
279 static int dn_short_output(struct neighbour *neigh, struct sk_buff *skb)
281 struct net_device *dev = neigh->dev;
282 int headroom = dev->hard_header_len + sizeof(struct dn_short_packet) + 2;
283 struct dn_short_packet *sp;
285 struct dn_skb_cb *cb = DN_SKB_CB(skb);
288 if (skb_headroom(skb) < headroom) {
289 struct sk_buff *skb2 = skb_realloc_headroom(skb, headroom);
291 net_crit_ratelimited("dn_short_output: no memory\n");
297 net_info_ratelimited("dn_short_output: Increasing headroom\n");
300 data = skb_push(skb, sizeof(struct dn_short_packet) + 2);
301 *((__le16 *)data) = cpu_to_le16(skb->len - 2);
302 sp = (struct dn_short_packet *)(data+2);
304 sp->msgflg = DN_RT_PKT_SHORT|(cb->rt_flags&(DN_RT_F_RQR|DN_RT_F_RTS));
305 sp->dstnode = cb->dst;
306 sp->srcnode = cb->src;
307 sp->forward = cb->hops & 0x3f;
309 skb_reset_network_header(skb);
311 return NF_HOOK(NFPROTO_DECNET, NF_DN_POST_ROUTING, skb, NULL,
312 neigh->dev, dn_neigh_output_packet);
316 * Phase 3 output is the same is short output, execpt that
317 * it clears the area bits before transmission.
319 static int dn_phase3_output(struct neighbour *neigh, struct sk_buff *skb)
321 struct net_device *dev = neigh->dev;
322 int headroom = dev->hard_header_len + sizeof(struct dn_short_packet) + 2;
323 struct dn_short_packet *sp;
325 struct dn_skb_cb *cb = DN_SKB_CB(skb);
327 if (skb_headroom(skb) < headroom) {
328 struct sk_buff *skb2 = skb_realloc_headroom(skb, headroom);
330 net_crit_ratelimited("dn_phase3_output: no memory\n");
336 net_info_ratelimited("dn_phase3_output: Increasing headroom\n");
339 data = skb_push(skb, sizeof(struct dn_short_packet) + 2);
340 *((__le16 *)data) = cpu_to_le16(skb->len - 2);
341 sp = (struct dn_short_packet *)(data + 2);
343 sp->msgflg = DN_RT_PKT_SHORT|(cb->rt_flags&(DN_RT_F_RQR|DN_RT_F_RTS));
344 sp->dstnode = cb->dst & cpu_to_le16(0x03ff);
345 sp->srcnode = cb->src & cpu_to_le16(0x03ff);
346 sp->forward = cb->hops & 0x3f;
348 skb_reset_network_header(skb);
350 return NF_HOOK(NFPROTO_DECNET, NF_DN_POST_ROUTING, skb, NULL,
351 neigh->dev, dn_neigh_output_packet);
355 * Unfortunately, the neighbour code uses the device in its hash
356 * function, so we don't get any advantage from it. This function
357 * basically does a neigh_lookup(), but without comparing the device
358 * field. This is required for the On-Ethernet cache
362 * Pointopoint link receives a hello message
364 void dn_neigh_pointopoint_hello(struct sk_buff *skb)
370 * Ethernet router hello message received
372 int dn_neigh_router_hello(struct sk_buff *skb)
374 struct rtnode_hello_message *msg = (struct rtnode_hello_message *)skb->data;
376 struct neighbour *neigh;
378 struct dn_dev *dn_db;
381 src = dn_eth2dn(msg->id);
383 neigh = __neigh_lookup(&dn_neigh_table, &src, skb->dev, 1);
385 dn = (struct dn_neigh *)neigh;
388 write_lock(&neigh->lock);
390 neigh->used = jiffies;
391 dn_db = rcu_dereference(neigh->dev->dn_ptr);
393 if (!(neigh->nud_state & NUD_PERMANENT)) {
394 neigh->updated = jiffies;
396 if (neigh->dev->type == ARPHRD_ETHER)
397 memcpy(neigh->ha, ð_hdr(skb)->h_source, ETH_ALEN);
399 dn->blksize = le16_to_cpu(msg->blksize);
400 dn->priority = msg->priority;
402 dn->flags &= ~DN_NDFLAG_P3;
404 switch (msg->iinfo & DN_RT_INFO_TYPE) {
405 case DN_RT_INFO_L1RT:
406 dn->flags &=~DN_NDFLAG_R2;
407 dn->flags |= DN_NDFLAG_R1;
409 case DN_RT_INFO_L2RT:
410 dn->flags |= DN_NDFLAG_R2;
414 /* Only use routers in our area */
415 if ((le16_to_cpu(src)>>10) == (le16_to_cpu((decnet_address))>>10)) {
416 if (!dn_db->router) {
417 dn_db->router = neigh_clone(neigh);
419 if (msg->priority > ((struct dn_neigh *)dn_db->router)->priority)
420 neigh_release(xchg(&dn_db->router, neigh_clone(neigh)));
423 write_unlock(&neigh->lock);
424 neigh_release(neigh);
432 * Endnode hello message received
434 int dn_neigh_endnode_hello(struct sk_buff *skb)
436 struct endnode_hello_message *msg = (struct endnode_hello_message *)skb->data;
437 struct neighbour *neigh;
441 src = dn_eth2dn(msg->id);
443 neigh = __neigh_lookup(&dn_neigh_table, &src, skb->dev, 1);
445 dn = (struct dn_neigh *)neigh;
448 write_lock(&neigh->lock);
450 neigh->used = jiffies;
452 if (!(neigh->nud_state & NUD_PERMANENT)) {
453 neigh->updated = jiffies;
455 if (neigh->dev->type == ARPHRD_ETHER)
456 memcpy(neigh->ha, ð_hdr(skb)->h_source, ETH_ALEN);
457 dn->flags &= ~(DN_NDFLAG_R1 | DN_NDFLAG_R2);
458 dn->blksize = le16_to_cpu(msg->blksize);
462 write_unlock(&neigh->lock);
463 neigh_release(neigh);
470 static char *dn_find_slot(char *base, int max, int priority)
473 unsigned char *min = NULL;
475 base += 6; /* skip first id */
477 for(i = 0; i < max; i++) {
478 if (!min || (*base < *min))
480 base += 7; /* find next priority */
486 return (*min < priority) ? (min - 6) : NULL;
489 struct elist_cb_state {
490 struct net_device *dev;
496 static void neigh_elist_cb(struct neighbour *neigh, void *_info)
498 struct elist_cb_state *s = _info;
501 if (neigh->dev != s->dev)
504 dn = (struct dn_neigh *) neigh;
505 if (!(dn->flags & (DN_NDFLAG_R1|DN_NDFLAG_R2)))
509 s->rs = dn_find_slot(s->ptr, s->n, dn->priority);
515 dn_dn2eth(s->rs, dn->addr);
517 *(s->rs) = neigh->nud_state & NUD_CONNECTED ? 0x80 : 0x0;
518 *(s->rs) |= dn->priority;
522 int dn_neigh_elist(struct net_device *dev, unsigned char *ptr, int n)
524 struct elist_cb_state state;
532 neigh_for_each(&dn_neigh_table, neigh_elist_cb, &state);
538 #ifdef CONFIG_PROC_FS
540 static inline void dn_neigh_format_entry(struct seq_file *seq,
543 struct dn_neigh *dn = (struct dn_neigh *) n;
544 char buf[DN_ASCBUF_LEN];
547 seq_printf(seq, "%-7s %s%s%s %02x %02d %07ld %-8s\n",
548 dn_addr2asc(le16_to_cpu(dn->addr), buf),
549 (dn->flags&DN_NDFLAG_R1) ? "1" : "-",
550 (dn->flags&DN_NDFLAG_R2) ? "2" : "-",
551 (dn->flags&DN_NDFLAG_P3) ? "3" : "-",
553 atomic_read(&dn->n.refcnt),
555 (dn->n.dev) ? dn->n.dev->name : "?");
556 read_unlock(&n->lock);
559 static int dn_neigh_seq_show(struct seq_file *seq, void *v)
561 if (v == SEQ_START_TOKEN) {
562 seq_puts(seq, "Addr Flags State Use Blksize Dev\n");
564 dn_neigh_format_entry(seq, v);
570 static void *dn_neigh_seq_start(struct seq_file *seq, loff_t *pos)
572 return neigh_seq_start(seq, pos, &dn_neigh_table,
573 NEIGH_SEQ_NEIGH_ONLY);
576 static const struct seq_operations dn_neigh_seq_ops = {
577 .start = dn_neigh_seq_start,
578 .next = neigh_seq_next,
579 .stop = neigh_seq_stop,
580 .show = dn_neigh_seq_show,
583 static int dn_neigh_seq_open(struct inode *inode, struct file *file)
585 return seq_open_net(inode, file, &dn_neigh_seq_ops,
586 sizeof(struct neigh_seq_state));
589 static const struct file_operations dn_neigh_seq_fops = {
590 .owner = THIS_MODULE,
591 .open = dn_neigh_seq_open,
594 .release = seq_release_net,
599 void __init dn_neigh_init(void)
601 neigh_table_init(NEIGH_DN_TABLE, &dn_neigh_table);
602 proc_create("decnet_neigh", S_IRUGO, init_net.proc_net,
606 void __exit dn_neigh_cleanup(void)
608 remove_proc_entry("decnet_neigh", init_net.proc_net);
609 neigh_table_clear(NEIGH_DN_TABLE, &dn_neigh_table);