linux/net/decnet/dn_neigh.c

608 lines
16 KiB
C
Raw Normal View History

/*
* 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/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 <asm/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 u32 dn_neigh_hash(const void *pkey, const struct net_device *dev);
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 sk_buff *);
static int dn_short_output(struct sk_buff *);
static int dn_phase3_output(struct sk_buff *);
/*
* For talking to broadcast devices: Ethernet & PPP
*/
static struct neigh_ops dn_long_ops = {
.family = AF_DECnet,
.error_report = dn_long_error_report,
.output = dn_long_output,
.connected_output = dn_long_output,
.hh_output = dev_queue_xmit,
.queue_xmit = dev_queue_xmit,
};
/*
* For talking to pointopoint and multidrop devices: DDCMP and X.25
*/
static struct neigh_ops dn_short_ops = {
.family = AF_DECnet,
.error_report = dn_short_error_report,
.output = dn_short_output,
.connected_output = dn_short_output,
.hh_output = dev_queue_xmit,
.queue_xmit = dev_queue_xmit,
};
/*
* For talking to DECnet phase III nodes
*/
static 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,
.hh_output = dev_queue_xmit,
.queue_xmit = dev_queue_xmit
};
struct neigh_table dn_neigh_table = {
.family = PF_DECnet,
.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 = 3,
.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 u32 dn_neigh_hash(const void *pkey, const struct net_device *dev)
{
return jhash_2words(*(__u16 *)pkey, 0, dn_neigh_table.hash_rnd);
}
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 {
if (net_ratelimit())
printk(KERN_DEBUG "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 = dst->neighbour;
struct net_device *dev = neigh->dev;
char mac_addr[ETH_ALEN];
dn_dn2eth(mac_addr, rt->rt_local_src);
if (dev_hard_header(skb, dev, ntohs(skb->protocol), neigh->ha,
mac_addr, skb->len) >= 0)
return neigh->ops->queue_xmit(skb);
if (net_ratelimit())
printk(KERN_DEBUG "dn_neigh_output_packet: oops, can't send packet\n");
kfree_skb(skb);
return -EINVAL;
}
static int dn_long_output(struct sk_buff *skb)
{
struct dst_entry *dst = skb_dst(skb);
struct neighbour *neigh = dst->neighbour;
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) {
if (net_ratelimit())
printk(KERN_CRIT "dn_long_output: no memory\n");
kfree_skb(skb);
return -ENOBUFS;
}
kfree_skb(skb);
skb = skb2;
if (net_ratelimit())
printk(KERN_INFO "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(PF_DECnet, NF_DN_POST_ROUTING, skb, NULL, neigh->dev, dn_neigh_output_packet);
}
static int dn_short_output(struct sk_buff *skb)
{
struct dst_entry *dst = skb_dst(skb);
struct neighbour *neigh = dst->neighbour;
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) {
if (net_ratelimit())
printk(KERN_CRIT "dn_short_output: no memory\n");
kfree_skb(skb);
return -ENOBUFS;
}
kfree_skb(skb);
skb = skb2;
if (net_ratelimit())
printk(KERN_INFO "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(PF_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 sk_buff *skb)
{
struct dst_entry *dst = skb_dst(skb);
struct neighbour *neigh = dst->neighbour;
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) {
if (net_ratelimit())
printk(KERN_CRIT "dn_phase3_output: no memory\n");
kfree_skb(skb);
return -ENOBUFS;
}
kfree_skb(skb);
skb = skb2;
if (net_ratelimit())
printk(KERN_INFO "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(PF_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 = (struct dn_dev *)neigh->dev->dn_ptr;
if (!(neigh->nud_state & NUD_PERMANENT)) {
neigh->updated = jiffies;
if (neigh->dev->type == ARPHRD_ETHER)
memcpy(neigh->ha, &eth_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, &eth_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)
{
[NETNS]: Modify the neighbour table code so it handles multiple network namespaces I'm actually surprised at how much was involved. At first glance it appears that the neighbour table data structures are already split by network device so all that should be needed is to modify the user interface commands to filter the set of neighbours by the network namespace of their devices. However a couple things turned up while I was reading through the code. The proxy neighbour table allows entries with no network device, and the neighbour parms are per network device (except for the defaults) so they now need a per network namespace default. So I updated the two structures (which surprised me) with their very own network namespace parameter. Updated the relevant lookup and destroy routines with a network namespace parameter and modified the code that interacts with users to filter out neighbour table entries for devices of other namespaces. I'm a little concerned that we can modify and display the global table configuration and from all network namespaces. But this appears good enough for now. I keep thinking modifying the neighbour table to have per network namespace instances of each table type would should be cleaner. The hash table is already dynamically sized so there are it is not a limiter. The default parameter would be straight forward to take care of. However when I look at the how the network table is built and used I still find some assumptions that there is only a single neighbour table for each type of table in the kernel. The netlink operations, neigh_seq_start, the non-core network users that call neigh_lookup. So while it might be doable it would require more refactoring than my current approach of just doing a little extra filtering in the code. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Daniel Lezcano <dlezcano@fr.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-01-24 08:13:18 +00:00
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,
[NETNS]: Modify the neighbour table code so it handles multiple network namespaces I'm actually surprised at how much was involved. At first glance it appears that the neighbour table data structures are already split by network device so all that should be needed is to modify the user interface commands to filter the set of neighbours by the network namespace of their devices. However a couple things turned up while I was reading through the code. The proxy neighbour table allows entries with no network device, and the neighbour parms are per network device (except for the defaults) so they now need a per network namespace default. So I updated the two structures (which surprised me) with their very own network namespace parameter. Updated the relevant lookup and destroy routines with a network namespace parameter and modified the code that interacts with users to filter out neighbour table entries for devices of other namespaces. I'm a little concerned that we can modify and display the global table configuration and from all network namespaces. But this appears good enough for now. I keep thinking modifying the neighbour table to have per network namespace instances of each table type would should be cleaner. The hash table is already dynamically sized so there are it is not a limiter. The default parameter would be straight forward to take care of. However when I look at the how the network table is built and used I still find some assumptions that there is only a single neighbour table for each type of table in the kernel. The netlink operations, neigh_seq_start, the non-core network users that call neigh_lookup. So while it might be doable it would require more refactoring than my current approach of just doing a little extra filtering in the code. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Daniel Lezcano <dlezcano@fr.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-01-24 08:13:18 +00:00
.release = seq_release_net,
};
#endif
void __init dn_neigh_init(void)
{
neigh_table_init(&dn_neigh_table);
proc_net_fops_create(&init_net, "decnet_neigh", S_IRUGO, &dn_neigh_seq_fops);
}
void __exit dn_neigh_cleanup(void)
{
proc_net_remove(&init_net, "decnet_neigh");
neigh_table_clear(&dn_neigh_table);
}