dn_neigh.c
/*
* DECnet An implementation of the DECnet protocol suite for the LINUX
* operating system. DECnet is implemented using the BSD Socket
* interface as the means of communication with the user level.
*
* DECnet Neighbour Functions (Adjacency Database and
* On-Ethernet Cache)
*
* Author: Steve Whitehouse <SteveW@ACM.org>
*
*
* Changes:
* Steve Whitehouse : Fixed router listing routine
* Steve Whitehouse : Added error_report functions
* Steve Whitehouse : Added default router detection
* Steve Whitehouse : Hop counts in outgoing messages
* Steve Whitehouse : Fixed src/dst in outgoing messages so
* forwarding now stands a good chance of
* working.
* Steve Whitehouse : Fixed neighbour states (for now anyway).
* Steve Whitehouse : Made error_report functions dummies. This
* is not the right place to return skbs.
* Steve Whitehouse : Convert to seq_file
*
*/
#include <linux/net.h>
#include <linux/module.h>
#include <linux/socket.h>
#include <linux/if_arp.h>
#include <linux/slab.h>
#include <linux/if_ether.h>
#include <linux/init.h>
#include <linux/proc_fs.h>
#include <linux/string.h>
#include <linux/netfilter_decnet.h>
#include <linux/spinlock.h>
#include <linux/seq_file.h>
#include <linux/rcupdate.h>
#include <linux/jhash.h>
#include <linux/atomic.h>
#include <net/net_namespace.h>
#include <net/neighbour.h>
#include <net/dst.h>
#include <net/flow.h>
#include <net/dn.h>
#include <net/dn_dev.h>
#include <net/dn_neigh.h>
#include <net/dn_route.h>
static int dn_neigh_construct(struct neighbour *);
static void dn_long_error_report(struct neighbour *, struct sk_buff *);
static void dn_short_error_report(struct neighbour *, struct sk_buff *);
static int dn_long_output(struct neighbour *, struct sk_buff *);
static int dn_short_output(struct neighbour *, struct sk_buff *);
static int dn_phase3_output(struct neighbour *, struct sk_buff *);
/*
* For talking to broadcast devices: Ethernet & PPP
*/
static const struct neigh_ops dn_long_ops = {
.family = AF_DECnet,
.error_report = dn_long_error_report,
.output = dn_long_output,
.connected_output = dn_long_output,
};
/*
* For talking to pointopoint and multidrop devices: DDCMP and X.25
*/
static const struct neigh_ops dn_short_ops = {
.family = AF_DECnet,
.error_report = dn_short_error_report,
.output = dn_short_output,
.connected_output = dn_short_output,
};
/*
* For talking to DECnet phase III nodes
*/
static const struct neigh_ops dn_phase3_ops = {
.family = AF_DECnet,
.error_report = dn_short_error_report, /* Can use short version here */
.output = dn_phase3_output,
.connected_output = dn_phase3_output,
};
static u32 dn_neigh_hash(const void *pkey,
const struct net_device *dev,
__u32 *hash_rnd)
{
return jhash_2words(*(__u16 *)pkey, 0, hash_rnd[0]);
}
struct neigh_table dn_neigh_table = {
.family = PF_DECnet,
.entry_size = NEIGH_ENTRY_SIZE(sizeof(struct dn_neigh)),
.key_len = sizeof(__le16),
.hash = dn_neigh_hash,
.constructor = dn_neigh_construct,
.id = "dn_neigh_cache",
.parms ={
.tbl = &dn_neigh_table,
.base_reachable_time = 30 * HZ,
.retrans_time = 1 * HZ,
.gc_staletime = 60 * HZ,
.reachable_time = 30 * HZ,
.delay_probe_time = 5 * HZ,
.queue_len_bytes = 64*1024,
.ucast_probes = 0,
.app_probes = 0,
.mcast_probes = 0,
.anycast_delay = 0,
.proxy_delay = 0,
.proxy_qlen = 0,
.locktime = 1 * HZ,
},
.gc_interval = 30 * HZ,
.gc_thresh1 = 128,
.gc_thresh2 = 512,
.gc_thresh3 = 1024,
};
static int dn_neigh_construct(struct neighbour *neigh)
{
struct net_device *dev = neigh->dev;
struct dn_neigh *dn = (struct dn_neigh *)neigh;
struct dn_dev *dn_db;
struct neigh_parms *parms;
rcu_read_lock();
dn_db = rcu_dereference(dev->dn_ptr);
if (dn_db == NULL) {
rcu_read_unlock();
return -EINVAL;
}
parms = dn_db->neigh_parms;
if (!parms) {
rcu_read_unlock();
return -EINVAL;
}
__neigh_parms_put(neigh->parms);
neigh->parms = neigh_parms_clone(parms);
if (dn_db->use_long)
neigh->ops = &dn_long_ops;
else
neigh->ops = &dn_short_ops;
rcu_read_unlock();
if (dn->flags & DN_NDFLAG_P3)
neigh->ops = &dn_phase3_ops;
neigh->nud_state = NUD_NOARP;
neigh->output = neigh->ops->connected_output;
if ((dev->type == ARPHRD_IPGRE) || (dev->flags & IFF_POINTOPOINT))
memcpy(neigh->ha, dev->broadcast, dev->addr_len);
else if ((dev->type == ARPHRD_ETHER) || (dev->type == ARPHRD_LOOPBACK))
dn_dn2eth(neigh->ha, dn->addr);
else {
net_dbg_ratelimited("Trying to create neigh for hw %d\n",
dev->type);
return -EINVAL;
}
/*
* Make an estimate of the remote block size by assuming that its
* two less then the device mtu, which it true for ethernet (and
* other things which support long format headers) since there is
* an extra length field (of 16 bits) which isn't part of the
* ethernet headers and which the DECnet specs won't admit is part
* of the DECnet routing headers either.
*
* If we over estimate here its no big deal, the NSP negotiations
* will prevent us from sending packets which are too large for the
* remote node to handle. In any case this figure is normally updated
* by a hello message in most cases.
*/
dn->blksize = dev->mtu - 2;
return 0;
}
static void dn_long_error_report(struct neighbour *neigh, struct sk_buff *skb)
{
printk(KERN_DEBUG "dn_long_error_report: called\n");
kfree_skb(skb);
}
static void dn_short_error_report(struct neighbour *neigh, struct sk_buff *skb)
{
printk(KERN_DEBUG "dn_short_error_report: called\n");
kfree_skb(skb);
}
static int dn_neigh_output_packet(struct sk_buff *skb)
{
struct dst_entry *dst = skb_dst(skb);
struct dn_route *rt = (struct dn_route *)dst;
struct neighbour *neigh = rt->n;
struct net_device *dev = neigh->dev;
char mac_addr[ETH_ALEN];
unsigned int seq;
int err;
dn_dn2eth(mac_addr, rt->rt_local_src);
do {
seq = read_seqbegin(&neigh->ha_lock);
err = dev_hard_header(skb, dev, ntohs(skb->protocol),
neigh->ha, mac_addr, skb->len);
} while (read_seqretry(&neigh->ha_lock, seq));
if (err >= 0)
err = dev_queue_xmit(skb);
else {
kfree_skb(skb);
err = -EINVAL;
}
return err;
}
static int dn_long_output(struct neighbour *neigh, struct sk_buff *skb)
{
struct net_device *dev = neigh->dev;
int headroom = dev->hard_header_len + sizeof(struct dn_long_packet) + 3;
unsigned char *data;
struct dn_long_packet *lp;
struct dn_skb_cb *cb = DN_SKB_CB(skb);
if (skb_headroom(skb) < headroom) {
struct sk_buff *skb2 = skb_realloc_headroom(skb, headroom);
if (skb2 == NULL) {
net_crit_ratelimited("dn_long_output: no memory\n");
kfree_skb(skb);
return -ENOBUFS;
}
consume_skb(skb);
skb = skb2;
net_info_ratelimited("dn_long_output: Increasing headroom\n");
}
data = skb_push(skb, sizeof(struct dn_long_packet) + 3);
lp = (struct dn_long_packet *)(data+3);
*((__le16 *)data) = cpu_to_le16(skb->len - 2);
*(data + 2) = 1 | DN_RT_F_PF; /* Padding */
lp->msgflg = DN_RT_PKT_LONG|(cb->rt_flags&(DN_RT_F_IE|DN_RT_F_RQR|DN_RT_F_RTS));
lp->d_area = lp->d_subarea = 0;
dn_dn2eth(lp->d_id, cb->dst);
lp->s_area = lp->s_subarea = 0;
dn_dn2eth(lp->s_id, cb->src);
lp->nl2 = 0;
lp->visit_ct = cb->hops & 0x3f;
lp->s_class = 0;
lp->pt = 0;
skb_reset_network_header(skb);
return NF_HOOK(NFPROTO_DECNET, NF_DN_POST_ROUTING, skb, NULL,
neigh->dev, dn_neigh_output_packet);
}
static int dn_short_output(struct neighbour *neigh, struct sk_buff *skb)
{
struct net_device *dev = neigh->dev;
int headroom = dev->hard_header_len + sizeof(struct dn_short_packet) + 2;
struct dn_short_packet *sp;
unsigned char *data;
struct dn_skb_cb *cb = DN_SKB_CB(skb);
if (skb_headroom(skb) < headroom) {
struct sk_buff *skb2 = skb_realloc_headroom(skb, headroom);
if (skb2 == NULL) {
net_crit_ratelimited("dn_short_output: no memory\n");
kfree_skb(skb);
return -ENOBUFS;
}
consume_skb(skb);
skb = skb2;
net_info_ratelimited("dn_short_output: Increasing headroom\n");
}
data = skb_push(skb, sizeof(struct dn_short_packet) + 2);
*((__le16 *)data) = cpu_to_le16(skb->len - 2);
sp = (struct dn_short_packet *)(data+2);
sp->msgflg = DN_RT_PKT_SHORT|(cb->rt_flags&(DN_RT_F_RQR|DN_RT_F_RTS));
sp->dstnode = cb->dst;
sp->srcnode = cb->src;
sp->forward = cb->hops & 0x3f;
skb_reset_network_header(skb);
return NF_HOOK(NFPROTO_DECNET, NF_DN_POST_ROUTING, skb, NULL,
neigh->dev, dn_neigh_output_packet);
}
/*
* Phase 3 output is the same is short output, execpt that
* it clears the area bits before transmission.
*/
static int dn_phase3_output(struct neighbour *neigh, struct sk_buff *skb)
{
struct net_device *dev = neigh->dev;
int headroom = dev->hard_header_len + sizeof(struct dn_short_packet) + 2;
struct dn_short_packet *sp;
unsigned char *data;
struct dn_skb_cb *cb = DN_SKB_CB(skb);
if (skb_headroom(skb) < headroom) {
struct sk_buff *skb2 = skb_realloc_headroom(skb, headroom);
if (skb2 == NULL) {
net_crit_ratelimited("dn_phase3_output: no memory\n");
kfree_skb(skb);
return -ENOBUFS;
}
consume_skb(skb);
skb = skb2;
net_info_ratelimited("dn_phase3_output: Increasing headroom\n");
}
data = skb_push(skb, sizeof(struct dn_short_packet) + 2);
*((__le16 *)data) = cpu_to_le16(skb->len - 2);
sp = (struct dn_short_packet *)(data + 2);
sp->msgflg = DN_RT_PKT_SHORT|(cb->rt_flags&(DN_RT_F_RQR|DN_RT_F_RTS));
sp->dstnode = cb->dst & cpu_to_le16(0x03ff);
sp->srcnode = cb->src & cpu_to_le16(0x03ff);
sp->forward = cb->hops & 0x3f;
skb_reset_network_header(skb);
return NF_HOOK(NFPROTO_DECNET, NF_DN_POST_ROUTING, skb, NULL,
neigh->dev, dn_neigh_output_packet);
}
/*
* Unfortunately, the neighbour code uses the device in its hash
* function, so we don't get any advantage from it. This function
* basically does a neigh_lookup(), but without comparing the device
* field. This is required for the On-Ethernet cache
*/
/*
* Pointopoint link receives a hello message
*/
void dn_neigh_pointopoint_hello(struct sk_buff *skb)
{
kfree_skb(skb);
}
/*
* Ethernet router hello message received
*/
int dn_neigh_router_hello(struct sk_buff *skb)
{
struct rtnode_hello_message *msg = (struct rtnode_hello_message *)skb->data;
struct neighbour *neigh;
struct dn_neigh *dn;
struct dn_dev *dn_db;
__le16 src;
src = dn_eth2dn(msg->id);
neigh = __neigh_lookup(&dn_neigh_table, &src, skb->dev, 1);
dn = (struct dn_neigh *)neigh;
if (neigh) {
write_lock(&neigh->lock);
neigh->used = jiffies;
dn_db = rcu_dereference(neigh->dev->dn_ptr);
if (!(neigh->nud_state & NUD_PERMANENT)) {
neigh->updated = jiffies;
if (neigh->dev->type == ARPHRD_ETHER)
memcpy(neigh->ha, ð_hdr(skb)->h_source, ETH_ALEN);
dn->blksize = le16_to_cpu(msg->blksize);
dn->priority = msg->priority;
dn->flags &= ~DN_NDFLAG_P3;
switch (msg->iinfo & DN_RT_INFO_TYPE) {
case DN_RT_INFO_L1RT:
dn->flags &=~DN_NDFLAG_R2;
dn->flags |= DN_NDFLAG_R1;
break;
case DN_RT_INFO_L2RT:
dn->flags |= DN_NDFLAG_R2;
}
}
/* Only use routers in our area */
if ((le16_to_cpu(src)>>10) == (le16_to_cpu((decnet_address))>>10)) {
if (!dn_db->router) {
dn_db->router = neigh_clone(neigh);
} else {
if (msg->priority > ((struct dn_neigh *)dn_db->router)->priority)
neigh_release(xchg(&dn_db->router, neigh_clone(neigh)));
}
}
write_unlock(&neigh->lock);
neigh_release(neigh);
}
kfree_skb(skb);
return 0;
}
/*
* Endnode hello message received
*/
int dn_neigh_endnode_hello(struct sk_buff *skb)
{
struct endnode_hello_message *msg = (struct endnode_hello_message *)skb->data;
struct neighbour *neigh;
struct dn_neigh *dn;
__le16 src;
src = dn_eth2dn(msg->id);
neigh = __neigh_lookup(&dn_neigh_table, &src, skb->dev, 1);
dn = (struct dn_neigh *)neigh;
if (neigh) {
write_lock(&neigh->lock);
neigh->used = jiffies;
if (!(neigh->nud_state & NUD_PERMANENT)) {
neigh->updated = jiffies;
if (neigh->dev->type == ARPHRD_ETHER)
memcpy(neigh->ha, ð_hdr(skb)->h_source, ETH_ALEN);
dn->flags &= ~(DN_NDFLAG_R1 | DN_NDFLAG_R2);
dn->blksize = le16_to_cpu(msg->blksize);
dn->priority = 0;
}
write_unlock(&neigh->lock);
neigh_release(neigh);
}
kfree_skb(skb);
return 0;
}
static char *dn_find_slot(char *base, int max, int priority)
{
int i;
unsigned char *min = NULL;
base += 6; /* skip first id */
for(i = 0; i < max; i++) {
if (!min || (*base < *min))
min = base;
base += 7; /* find next priority */
}
if (!min)
return NULL;
return (*min < priority) ? (min - 6) : NULL;
}
struct elist_cb_state {
struct net_device *dev;
unsigned char *ptr;
unsigned char *rs;
int t, n;
};
static void neigh_elist_cb(struct neighbour *neigh, void *_info)
{
struct elist_cb_state *s = _info;
struct dn_neigh *dn;
if (neigh->dev != s->dev)
return;
dn = (struct dn_neigh *) neigh;
if (!(dn->flags & (DN_NDFLAG_R1|DN_NDFLAG_R2)))
return;
if (s->t == s->n)
s->rs = dn_find_slot(s->ptr, s->n, dn->priority);
else
s->t++;
if (s->rs == NULL)
return;
dn_dn2eth(s->rs, dn->addr);
s->rs += 6;
*(s->rs) = neigh->nud_state & NUD_CONNECTED ? 0x80 : 0x0;
*(s->rs) |= dn->priority;
s->rs++;
}
int dn_neigh_elist(struct net_device *dev, unsigned char *ptr, int n)
{
struct elist_cb_state state;
state.dev = dev;
state.t = 0;
state.n = n;
state.ptr = ptr;
state.rs = ptr;
neigh_for_each(&dn_neigh_table, neigh_elist_cb, &state);
return state.t;
}
#ifdef CONFIG_PROC_FS
static inline void dn_neigh_format_entry(struct seq_file *seq,
struct neighbour *n)
{
struct dn_neigh *dn = (struct dn_neigh *) n;
char buf[DN_ASCBUF_LEN];
read_lock(&n->lock);
seq_printf(seq, "%-7s %s%s%s %02x %02d %07ld %-8s\n",
dn_addr2asc(le16_to_cpu(dn->addr), buf),
(dn->flags&DN_NDFLAG_R1) ? "1" : "-",
(dn->flags&DN_NDFLAG_R2) ? "2" : "-",
(dn->flags&DN_NDFLAG_P3) ? "3" : "-",
dn->n.nud_state,
atomic_read(&dn->n.refcnt),
dn->blksize,
(dn->n.dev) ? dn->n.dev->name : "?");
read_unlock(&n->lock);
}
static int dn_neigh_seq_show(struct seq_file *seq, void *v)
{
if (v == SEQ_START_TOKEN) {
seq_puts(seq, "Addr Flags State Use Blksize Dev\n");
} else {
dn_neigh_format_entry(seq, v);
}
return 0;
}
static void *dn_neigh_seq_start(struct seq_file *seq, loff_t *pos)
{
return neigh_seq_start(seq, pos, &dn_neigh_table,
NEIGH_SEQ_NEIGH_ONLY);
}
static const struct seq_operations dn_neigh_seq_ops = {
.start = dn_neigh_seq_start,
.next = neigh_seq_next,
.stop = neigh_seq_stop,
.show = dn_neigh_seq_show,
};
static int dn_neigh_seq_open(struct inode *inode, struct file *file)
{
return seq_open_net(inode, file, &dn_neigh_seq_ops,
sizeof(struct neigh_seq_state));
}
static const struct file_operations dn_neigh_seq_fops = {
.owner = THIS_MODULE,
.open = dn_neigh_seq_open,
.read = seq_read,
.llseek = seq_lseek,
.release = seq_release_net,
};
#endif
void __init dn_neigh_init(void)
{
neigh_table_init(&dn_neigh_table);
proc_create("decnet_neigh", S_IRUGO, init_net.proc_net,
&dn_neigh_seq_fops);
}
void __exit dn_neigh_cleanup(void)
{
remove_proc_entry("decnet_neigh", init_net.proc_net);
neigh_table_clear(&dn_neigh_table);
}
