diff options
Diffstat (limited to 'net/decnet/dn_neigh.c')
| -rw-r--r-- | net/decnet/dn_neigh.c | 605 |
1 files changed, 605 insertions, 0 deletions
diff --git a/net/decnet/dn_neigh.c b/net/decnet/dn_neigh.c new file mode 100644 index 000000000..94b306f6d --- /dev/null +++ b/net/decnet/dn_neigh.c @@ -0,0 +1,605 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * 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] = SK_WMEM_MAX, + [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 = container_of(neigh, struct dn_neigh, n); + 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 net *net, 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, + &init_net, 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, + &init_net, 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, + &init_net, sk, skb, NULL, neigh->dev, + dn_neigh_output_packet); +} + +int dn_to_neigh_output(struct net *net, 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 = container_of(neigh, struct dn_neigh, n); + 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 net *net, 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 = container_of(neigh, struct dn_neigh, n); + + 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 net *net, 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 = container_of(neigh, struct dn_neigh, n); + + 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 = container_of(neigh, struct dn_neigh, n); + 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 = container_of(n, 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, + refcount_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, +}; +#endif + +void __init dn_neigh_init(void) +{ + neigh_table_init(NEIGH_DN_TABLE, &dn_neigh_table); + proc_create_net("decnet_neigh", 0444, init_net.proc_net, + &dn_neigh_seq_ops, sizeof(struct neigh_seq_state)); +} + +void __exit dn_neigh_cleanup(void) +{ + remove_proc_entry("decnet_neigh", init_net.proc_net); + neigh_table_clear(NEIGH_DN_TABLE, &dn_neigh_table); +} |