// 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); }