| // 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 > container_of(dn_db->router, |
| struct dn_neigh, n)->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); |
| } |