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_neigh_error_report(struct neighbour
*, struct sk_buff
*);
53 static int dn_neigh_output(struct neighbour
*neigh
, struct sk_buff
*skb
);
56 * Operations for adding the link layer header.
58 static const struct neigh_ops dn_neigh_ops
= {
60 .error_report
= dn_neigh_error_report
,
61 .output
= dn_neigh_output
,
62 .connected_output
= dn_neigh_output
,
65 static u32
dn_neigh_hash(const void *pkey
,
66 const struct net_device
*dev
,
69 return jhash_2words(*(__u16
*)pkey
, 0, hash_rnd
[0]);
72 static bool dn_key_eq(const struct neighbour
*neigh
, const void *pkey
)
74 return neigh_key_eq16(neigh
, pkey
);
77 struct neigh_table dn_neigh_table
= {
79 .entry_size
= NEIGH_ENTRY_SIZE(sizeof(struct dn_neigh
)),
80 .key_len
= sizeof(__le16
),
81 .protocol
= cpu_to_be16(ETH_P_DNA_RT
),
82 .hash
= dn_neigh_hash
,
84 .constructor
= dn_neigh_construct
,
85 .id
= "dn_neigh_cache",
87 .tbl
= &dn_neigh_table
,
88 .reachable_time
= 30 * HZ
,
90 [NEIGH_VAR_MCAST_PROBES
] = 0,
91 [NEIGH_VAR_UCAST_PROBES
] = 0,
92 [NEIGH_VAR_APP_PROBES
] = 0,
93 [NEIGH_VAR_RETRANS_TIME
] = 1 * HZ
,
94 [NEIGH_VAR_BASE_REACHABLE_TIME
] = 30 * HZ
,
95 [NEIGH_VAR_DELAY_PROBE_TIME
] = 5 * HZ
,
96 [NEIGH_VAR_GC_STALETIME
] = 60 * HZ
,
97 [NEIGH_VAR_QUEUE_LEN_BYTES
] = 64*1024,
98 [NEIGH_VAR_PROXY_QLEN
] = 0,
99 [NEIGH_VAR_ANYCAST_DELAY
] = 0,
100 [NEIGH_VAR_PROXY_DELAY
] = 0,
101 [NEIGH_VAR_LOCKTIME
] = 1 * HZ
,
104 .gc_interval
= 30 * HZ
,
110 static int dn_neigh_construct(struct neighbour
*neigh
)
112 struct net_device
*dev
= neigh
->dev
;
113 struct dn_neigh
*dn
= (struct dn_neigh
*)neigh
;
114 struct dn_dev
*dn_db
;
115 struct neigh_parms
*parms
;
118 dn_db
= rcu_dereference(dev
->dn_ptr
);
124 parms
= dn_db
->neigh_parms
;
130 __neigh_parms_put(neigh
->parms
);
131 neigh
->parms
= neigh_parms_clone(parms
);
134 neigh
->ops
= &dn_neigh_ops
;
135 neigh
->nud_state
= NUD_NOARP
;
136 neigh
->output
= neigh
->ops
->connected_output
;
138 if ((dev
->type
== ARPHRD_IPGRE
) || (dev
->flags
& IFF_POINTOPOINT
))
139 memcpy(neigh
->ha
, dev
->broadcast
, dev
->addr_len
);
140 else if ((dev
->type
== ARPHRD_ETHER
) || (dev
->type
== ARPHRD_LOOPBACK
))
141 dn_dn2eth(neigh
->ha
, dn
->addr
);
143 net_dbg_ratelimited("Trying to create neigh for hw %d\n",
149 * Make an estimate of the remote block size by assuming that its
150 * two less then the device mtu, which it true for ethernet (and
151 * other things which support long format headers) since there is
152 * an extra length field (of 16 bits) which isn't part of the
153 * ethernet headers and which the DECnet specs won't admit is part
154 * of the DECnet routing headers either.
156 * If we over estimate here its no big deal, the NSP negotiations
157 * will prevent us from sending packets which are too large for the
158 * remote node to handle. In any case this figure is normally updated
159 * by a hello message in most cases.
161 dn
->blksize
= dev
->mtu
- 2;
166 static void dn_neigh_error_report(struct neighbour
*neigh
, struct sk_buff
*skb
)
168 printk(KERN_DEBUG
"dn_neigh_error_report: called\n");
172 static int dn_neigh_output(struct neighbour
*neigh
, struct sk_buff
*skb
)
174 struct dst_entry
*dst
= skb_dst(skb
);
175 struct dn_route
*rt
= (struct dn_route
*)dst
;
176 struct net_device
*dev
= neigh
->dev
;
177 char mac_addr
[ETH_ALEN
];
181 dn_dn2eth(mac_addr
, rt
->rt_local_src
);
183 seq
= read_seqbegin(&neigh
->ha_lock
);
184 err
= dev_hard_header(skb
, dev
, ntohs(skb
->protocol
),
185 neigh
->ha
, mac_addr
, skb
->len
);
186 } while (read_seqretry(&neigh
->ha_lock
, seq
));
189 err
= dev_queue_xmit(skb
);
197 static int dn_neigh_output_packet(struct sock
*sk
, struct sk_buff
*skb
)
199 struct dst_entry
*dst
= skb_dst(skb
);
200 struct dn_route
*rt
= (struct dn_route
*)dst
;
201 struct neighbour
*neigh
= rt
->n
;
203 return neigh
->output(neigh
, skb
);
207 * For talking to broadcast devices: Ethernet & PPP
209 static int dn_long_output(struct neighbour
*neigh
, struct sock
*sk
,
212 struct net_device
*dev
= neigh
->dev
;
213 int headroom
= dev
->hard_header_len
+ sizeof(struct dn_long_packet
) + 3;
215 struct dn_long_packet
*lp
;
216 struct dn_skb_cb
*cb
= DN_SKB_CB(skb
);
219 if (skb_headroom(skb
) < headroom
) {
220 struct sk_buff
*skb2
= skb_realloc_headroom(skb
, headroom
);
222 net_crit_ratelimited("dn_long_output: no memory\n");
228 net_info_ratelimited("dn_long_output: Increasing headroom\n");
231 data
= skb_push(skb
, sizeof(struct dn_long_packet
) + 3);
232 lp
= (struct dn_long_packet
*)(data
+3);
234 *((__le16
*)data
) = cpu_to_le16(skb
->len
- 2);
235 *(data
+ 2) = 1 | DN_RT_F_PF
; /* Padding */
237 lp
->msgflg
= DN_RT_PKT_LONG
|(cb
->rt_flags
&(DN_RT_F_IE
|DN_RT_F_RQR
|DN_RT_F_RTS
));
238 lp
->d_area
= lp
->d_subarea
= 0;
239 dn_dn2eth(lp
->d_id
, cb
->dst
);
240 lp
->s_area
= lp
->s_subarea
= 0;
241 dn_dn2eth(lp
->s_id
, cb
->src
);
243 lp
->visit_ct
= cb
->hops
& 0x3f;
247 skb_reset_network_header(skb
);
249 return NF_HOOK(NFPROTO_DECNET
, NF_DN_POST_ROUTING
, sk
, skb
,
250 NULL
, neigh
->dev
, dn_neigh_output_packet
);
254 * For talking to pointopoint and multidrop devices: DDCMP and X.25
256 static int dn_short_output(struct neighbour
*neigh
, struct sock
*sk
,
259 struct net_device
*dev
= neigh
->dev
;
260 int headroom
= dev
->hard_header_len
+ sizeof(struct dn_short_packet
) + 2;
261 struct dn_short_packet
*sp
;
263 struct dn_skb_cb
*cb
= DN_SKB_CB(skb
);
266 if (skb_headroom(skb
) < headroom
) {
267 struct sk_buff
*skb2
= skb_realloc_headroom(skb
, headroom
);
269 net_crit_ratelimited("dn_short_output: no memory\n");
275 net_info_ratelimited("dn_short_output: Increasing headroom\n");
278 data
= skb_push(skb
, sizeof(struct dn_short_packet
) + 2);
279 *((__le16
*)data
) = cpu_to_le16(skb
->len
- 2);
280 sp
= (struct dn_short_packet
*)(data
+2);
282 sp
->msgflg
= DN_RT_PKT_SHORT
|(cb
->rt_flags
&(DN_RT_F_RQR
|DN_RT_F_RTS
));
283 sp
->dstnode
= cb
->dst
;
284 sp
->srcnode
= cb
->src
;
285 sp
->forward
= cb
->hops
& 0x3f;
287 skb_reset_network_header(skb
);
289 return NF_HOOK(NFPROTO_DECNET
, NF_DN_POST_ROUTING
, sk
, skb
,
290 NULL
, neigh
->dev
, dn_neigh_output_packet
);
294 * For talking to DECnet phase III nodes
295 * Phase 3 output is the same as short output, execpt that
296 * it clears the area bits before transmission.
298 static int dn_phase3_output(struct neighbour
*neigh
, struct sock
*sk
,
301 struct net_device
*dev
= neigh
->dev
;
302 int headroom
= dev
->hard_header_len
+ sizeof(struct dn_short_packet
) + 2;
303 struct dn_short_packet
*sp
;
305 struct dn_skb_cb
*cb
= DN_SKB_CB(skb
);
307 if (skb_headroom(skb
) < headroom
) {
308 struct sk_buff
*skb2
= skb_realloc_headroom(skb
, headroom
);
310 net_crit_ratelimited("dn_phase3_output: no memory\n");
316 net_info_ratelimited("dn_phase3_output: Increasing headroom\n");
319 data
= skb_push(skb
, sizeof(struct dn_short_packet
) + 2);
320 *((__le16
*)data
) = cpu_to_le16(skb
->len
- 2);
321 sp
= (struct dn_short_packet
*)(data
+ 2);
323 sp
->msgflg
= DN_RT_PKT_SHORT
|(cb
->rt_flags
&(DN_RT_F_RQR
|DN_RT_F_RTS
));
324 sp
->dstnode
= cb
->dst
& cpu_to_le16(0x03ff);
325 sp
->srcnode
= cb
->src
& cpu_to_le16(0x03ff);
326 sp
->forward
= cb
->hops
& 0x3f;
328 skb_reset_network_header(skb
);
330 return NF_HOOK(NFPROTO_DECNET
, NF_DN_POST_ROUTING
, sk
, skb
,
331 NULL
, neigh
->dev
, dn_neigh_output_packet
);
334 int dn_to_neigh_output(struct sock
*sk
, struct sk_buff
*skb
)
336 struct dst_entry
*dst
= skb_dst(skb
);
337 struct dn_route
*rt
= (struct dn_route
*) dst
;
338 struct neighbour
*neigh
= rt
->n
;
339 struct dn_neigh
*dn
= (struct dn_neigh
*)neigh
;
340 struct dn_dev
*dn_db
;
344 dn_db
= rcu_dereference(neigh
->dev
->dn_ptr
);
349 use_long
= dn_db
->use_long
;
352 if (dn
->flags
& DN_NDFLAG_P3
)
353 return dn_phase3_output(neigh
, sk
, skb
);
355 return dn_long_output(neigh
, sk
, skb
);
357 return dn_short_output(neigh
, sk
, skb
);
361 * Unfortunately, the neighbour code uses the device in its hash
362 * function, so we don't get any advantage from it. This function
363 * basically does a neigh_lookup(), but without comparing the device
364 * field. This is required for the On-Ethernet cache
368 * Pointopoint link receives a hello message
370 void dn_neigh_pointopoint_hello(struct sk_buff
*skb
)
376 * Ethernet router hello message received
378 int dn_neigh_router_hello(struct sock
*sk
, struct sk_buff
*skb
)
380 struct rtnode_hello_message
*msg
= (struct rtnode_hello_message
*)skb
->data
;
382 struct neighbour
*neigh
;
384 struct dn_dev
*dn_db
;
387 src
= dn_eth2dn(msg
->id
);
389 neigh
= __neigh_lookup(&dn_neigh_table
, &src
, skb
->dev
, 1);
391 dn
= (struct dn_neigh
*)neigh
;
394 write_lock(&neigh
->lock
);
396 neigh
->used
= jiffies
;
397 dn_db
= rcu_dereference(neigh
->dev
->dn_ptr
);
399 if (!(neigh
->nud_state
& NUD_PERMANENT
)) {
400 neigh
->updated
= jiffies
;
402 if (neigh
->dev
->type
== ARPHRD_ETHER
)
403 memcpy(neigh
->ha
, ð_hdr(skb
)->h_source
, ETH_ALEN
);
405 dn
->blksize
= le16_to_cpu(msg
->blksize
);
406 dn
->priority
= msg
->priority
;
408 dn
->flags
&= ~DN_NDFLAG_P3
;
410 switch (msg
->iinfo
& DN_RT_INFO_TYPE
) {
411 case DN_RT_INFO_L1RT
:
412 dn
->flags
&=~DN_NDFLAG_R2
;
413 dn
->flags
|= DN_NDFLAG_R1
;
415 case DN_RT_INFO_L2RT
:
416 dn
->flags
|= DN_NDFLAG_R2
;
420 /* Only use routers in our area */
421 if ((le16_to_cpu(src
)>>10) == (le16_to_cpu((decnet_address
))>>10)) {
422 if (!dn_db
->router
) {
423 dn_db
->router
= neigh_clone(neigh
);
425 if (msg
->priority
> ((struct dn_neigh
*)dn_db
->router
)->priority
)
426 neigh_release(xchg(&dn_db
->router
, neigh_clone(neigh
)));
429 write_unlock(&neigh
->lock
);
430 neigh_release(neigh
);
438 * Endnode hello message received
440 int dn_neigh_endnode_hello(struct sock
*sk
, struct sk_buff
*skb
)
442 struct endnode_hello_message
*msg
= (struct endnode_hello_message
*)skb
->data
;
443 struct neighbour
*neigh
;
447 src
= dn_eth2dn(msg
->id
);
449 neigh
= __neigh_lookup(&dn_neigh_table
, &src
, skb
->dev
, 1);
451 dn
= (struct dn_neigh
*)neigh
;
454 write_lock(&neigh
->lock
);
456 neigh
->used
= jiffies
;
458 if (!(neigh
->nud_state
& NUD_PERMANENT
)) {
459 neigh
->updated
= jiffies
;
461 if (neigh
->dev
->type
== ARPHRD_ETHER
)
462 memcpy(neigh
->ha
, ð_hdr(skb
)->h_source
, ETH_ALEN
);
463 dn
->flags
&= ~(DN_NDFLAG_R1
| DN_NDFLAG_R2
);
464 dn
->blksize
= le16_to_cpu(msg
->blksize
);
468 write_unlock(&neigh
->lock
);
469 neigh_release(neigh
);
476 static char *dn_find_slot(char *base
, int max
, int priority
)
479 unsigned char *min
= NULL
;
481 base
+= 6; /* skip first id */
483 for(i
= 0; i
< max
; i
++) {
484 if (!min
|| (*base
< *min
))
486 base
+= 7; /* find next priority */
492 return (*min
< priority
) ? (min
- 6) : NULL
;
495 struct elist_cb_state
{
496 struct net_device
*dev
;
502 static void neigh_elist_cb(struct neighbour
*neigh
, void *_info
)
504 struct elist_cb_state
*s
= _info
;
507 if (neigh
->dev
!= s
->dev
)
510 dn
= (struct dn_neigh
*) neigh
;
511 if (!(dn
->flags
& (DN_NDFLAG_R1
|DN_NDFLAG_R2
)))
515 s
->rs
= dn_find_slot(s
->ptr
, s
->n
, dn
->priority
);
521 dn_dn2eth(s
->rs
, dn
->addr
);
523 *(s
->rs
) = neigh
->nud_state
& NUD_CONNECTED
? 0x80 : 0x0;
524 *(s
->rs
) |= dn
->priority
;
528 int dn_neigh_elist(struct net_device
*dev
, unsigned char *ptr
, int n
)
530 struct elist_cb_state state
;
538 neigh_for_each(&dn_neigh_table
, neigh_elist_cb
, &state
);
544 #ifdef CONFIG_PROC_FS
546 static inline void dn_neigh_format_entry(struct seq_file
*seq
,
549 struct dn_neigh
*dn
= (struct dn_neigh
*) n
;
550 char buf
[DN_ASCBUF_LEN
];
553 seq_printf(seq
, "%-7s %s%s%s %02x %02d %07ld %-8s\n",
554 dn_addr2asc(le16_to_cpu(dn
->addr
), buf
),
555 (dn
->flags
&DN_NDFLAG_R1
) ? "1" : "-",
556 (dn
->flags
&DN_NDFLAG_R2
) ? "2" : "-",
557 (dn
->flags
&DN_NDFLAG_P3
) ? "3" : "-",
559 atomic_read(&dn
->n
.refcnt
),
561 (dn
->n
.dev
) ? dn
->n
.dev
->name
: "?");
562 read_unlock(&n
->lock
);
565 static int dn_neigh_seq_show(struct seq_file
*seq
, void *v
)
567 if (v
== SEQ_START_TOKEN
) {
568 seq_puts(seq
, "Addr Flags State Use Blksize Dev\n");
570 dn_neigh_format_entry(seq
, v
);
576 static void *dn_neigh_seq_start(struct seq_file
*seq
, loff_t
*pos
)
578 return neigh_seq_start(seq
, pos
, &dn_neigh_table
,
579 NEIGH_SEQ_NEIGH_ONLY
);
582 static const struct seq_operations dn_neigh_seq_ops
= {
583 .start
= dn_neigh_seq_start
,
584 .next
= neigh_seq_next
,
585 .stop
= neigh_seq_stop
,
586 .show
= dn_neigh_seq_show
,
589 static int dn_neigh_seq_open(struct inode
*inode
, struct file
*file
)
591 return seq_open_net(inode
, file
, &dn_neigh_seq_ops
,
592 sizeof(struct neigh_seq_state
));
595 static const struct file_operations dn_neigh_seq_fops
= {
596 .owner
= THIS_MODULE
,
597 .open
= dn_neigh_seq_open
,
600 .release
= seq_release_net
,
605 void __init
dn_neigh_init(void)
607 neigh_table_init(NEIGH_DN_TABLE
, &dn_neigh_table
);
608 proc_create("decnet_neigh", S_IRUGO
, init_net
.proc_net
,
612 void __exit
dn_neigh_cleanup(void)
614 remove_proc_entry("decnet_neigh", init_net
.proc_net
);
615 neigh_table_clear(NEIGH_DN_TABLE
, &dn_neigh_table
);