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authorAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-08-05 17:04:01 -0300
committerAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-08-05 17:04:01 -0300
commit57f0f512b273f60d52568b8c6b77e17f5636edc0 (patch)
tree5e910f0e82173f4ef4f51111366a3f1299037a7b /net/decnet/dn_neigh.c
Initial import
Diffstat (limited to 'net/decnet/dn_neigh.c')
-rw-r--r--net/decnet/dn_neigh.c616
1 files changed, 616 insertions, 0 deletions
diff --git a/net/decnet/dn_neigh.c b/net/decnet/dn_neigh.c
new file mode 100644
index 000000000..4507b188f
--- /dev/null
+++ b/net/decnet/dn_neigh.c
@@ -0,0 +1,616 @@
+/*
+ * 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_neigh_error_report(struct neighbour *, struct sk_buff *);
+static int dn_neigh_output(struct neighbour *neigh, struct sk_buff *skb);
+
+/*
+ * Operations for adding the link layer header.
+ */
+static const struct neigh_ops dn_neigh_ops = {
+ .family = AF_DECnet,
+ .error_report = dn_neigh_error_report,
+ .output = dn_neigh_output,
+ .connected_output = dn_neigh_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]);
+}
+
+static bool dn_key_eq(const struct neighbour *neigh, const void *pkey)
+{
+ return neigh_key_eq16(neigh, pkey);
+}
+
+struct neigh_table dn_neigh_table = {
+ .family = PF_DECnet,
+ .entry_size = NEIGH_ENTRY_SIZE(sizeof(struct dn_neigh)),
+ .key_len = sizeof(__le16),
+ .protocol = cpu_to_be16(ETH_P_DNA_RT),
+ .hash = dn_neigh_hash,
+ .key_eq = dn_key_eq,
+ .constructor = dn_neigh_construct,
+ .id = "dn_neigh_cache",
+ .parms ={
+ .tbl = &dn_neigh_table,
+ .reachable_time = 30 * HZ,
+ .data = {
+ [NEIGH_VAR_MCAST_PROBES] = 0,
+ [NEIGH_VAR_UCAST_PROBES] = 0,
+ [NEIGH_VAR_APP_PROBES] = 0,
+ [NEIGH_VAR_RETRANS_TIME] = 1 * HZ,
+ [NEIGH_VAR_BASE_REACHABLE_TIME] = 30 * HZ,
+ [NEIGH_VAR_DELAY_PROBE_TIME] = 5 * HZ,
+ [NEIGH_VAR_GC_STALETIME] = 60 * HZ,
+ [NEIGH_VAR_QUEUE_LEN_BYTES] = 64*1024,
+ [NEIGH_VAR_PROXY_QLEN] = 0,
+ [NEIGH_VAR_ANYCAST_DELAY] = 0,
+ [NEIGH_VAR_PROXY_DELAY] = 0,
+ [NEIGH_VAR_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);
+ rcu_read_unlock();
+
+ neigh->ops = &dn_neigh_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_neigh_error_report(struct neighbour *neigh, struct sk_buff *skb)
+{
+ printk(KERN_DEBUG "dn_neigh_error_report: called\n");
+ kfree_skb(skb);
+}
+
+static int dn_neigh_output(struct neighbour *neigh, struct sk_buff *skb)
+{
+ struct dst_entry *dst = skb_dst(skb);
+ struct dn_route *rt = (struct dn_route *)dst;
+ 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_neigh_output_packet(struct sock *sk, struct sk_buff *skb)
+{
+ struct dst_entry *dst = skb_dst(skb);
+ struct dn_route *rt = (struct dn_route *)dst;
+ struct neighbour *neigh = rt->n;
+
+ return neigh->output(neigh, skb);
+}
+
+/*
+ * For talking to broadcast devices: Ethernet & PPP
+ */
+static int dn_long_output(struct neighbour *neigh, struct sock *sk,
+ 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, sk, skb,
+ NULL, neigh->dev, dn_neigh_output_packet);
+}
+
+/*
+ * For talking to pointopoint and multidrop devices: DDCMP and X.25
+ */
+static int dn_short_output(struct neighbour *neigh, struct sock *sk,
+ 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, sk, skb,
+ NULL, neigh->dev, dn_neigh_output_packet);
+}
+
+/*
+ * For talking to DECnet phase III nodes
+ * Phase 3 output is the same as short output, execpt that
+ * it clears the area bits before transmission.
+ */
+static int dn_phase3_output(struct neighbour *neigh, struct sock *sk,
+ 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, sk, skb,
+ NULL, neigh->dev, dn_neigh_output_packet);
+}
+
+int dn_to_neigh_output(struct sock *sk, 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 dn_neigh *dn = (struct dn_neigh *)neigh;
+ struct dn_dev *dn_db;
+ bool use_long;
+
+ rcu_read_lock();
+ dn_db = rcu_dereference(neigh->dev->dn_ptr);
+ if (dn_db == NULL) {
+ rcu_read_unlock();
+ return -EINVAL;
+ }
+ use_long = dn_db->use_long;
+ rcu_read_unlock();
+
+ if (dn->flags & DN_NDFLAG_P3)
+ return dn_phase3_output(neigh, sk, skb);
+ if (use_long)
+ return dn_long_output(neigh, sk, skb);
+ else
+ return dn_short_output(neigh, sk, skb);
+}
+
+/*
+ * 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 sock *sk, 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, &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 sock *sk, 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)
+{
+ 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(NEIGH_DN_TABLE, &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(NEIGH_DN_TABLE, &dn_neigh_table);
+}