// SPDX-License-Identifier: GPL-2.0 #include #include #include #include #include #include #include #include #include #include "ila.h" struct ila_xlat_params { struct ila_params ip; int ifindex; }; struct ila_map { struct ila_xlat_params xp; struct rhash_head node; struct ila_map __rcu *next; struct rcu_head rcu; }; #define MAX_LOCKS 1024 #define LOCKS_PER_CPU 10 static int alloc_ila_locks(struct ila_net *ilan) { return alloc_bucket_spinlocks(&ilan->xlat.locks, &ilan->xlat.locks_mask, MAX_LOCKS, LOCKS_PER_CPU, GFP_KERNEL); } static u32 hashrnd __read_mostly; static __always_inline void __ila_hash_secret_init(void) { net_get_random_once(&hashrnd, sizeof(hashrnd)); } static inline u32 ila_locator_hash(struct ila_locator loc) { u32 *v = (u32 *)loc.v32; __ila_hash_secret_init(); return jhash_2words(v[0], v[1], hashrnd); } static inline spinlock_t *ila_get_lock(struct ila_net *ilan, struct ila_locator loc) { return &ilan->xlat.locks[ila_locator_hash(loc) & ilan->xlat.locks_mask]; } static inline int ila_cmp_wildcards(struct ila_map *ila, struct ila_addr *iaddr, int ifindex) { return (ila->xp.ifindex && ila->xp.ifindex != ifindex); } static inline int ila_cmp_params(struct ila_map *ila, struct ila_xlat_params *xp) { return (ila->xp.ifindex != xp->ifindex); } static int ila_cmpfn(struct rhashtable_compare_arg *arg, const void *obj) { const struct ila_map *ila = obj; return (ila->xp.ip.locator_match.v64 != *(__be64 *)arg->key); } static inline int ila_order(struct ila_map *ila) { int score = 0; if (ila->xp.ifindex) score += 1 << 1; return score; } static const struct rhashtable_params rht_params = { .nelem_hint = 1024, .head_offset = offsetof(struct ila_map, node), .key_offset = offsetof(struct ila_map, xp.ip.locator_match), .key_len = sizeof(u64), /* identifier */ .max_size = 1048576, .min_size = 256, .automatic_shrinking = true, .obj_cmpfn = ila_cmpfn, }; static int parse_nl_config(struct genl_info *info, struct ila_xlat_params *xp) { memset(xp, 0, sizeof(*xp)); if (info->attrs[ILA_ATTR_LOCATOR]) xp->ip.locator.v64 = (__force __be64)nla_get_u64( info->attrs[ILA_ATTR_LOCATOR]); if (info->attrs[ILA_ATTR_LOCATOR_MATCH]) xp->ip.locator_match.v64 = (__force __be64)nla_get_u64( info->attrs[ILA_ATTR_LOCATOR_MATCH]); if (info->attrs[ILA_ATTR_CSUM_MODE]) xp->ip.csum_mode = nla_get_u8(info->attrs[ILA_ATTR_CSUM_MODE]); else xp->ip.csum_mode = ILA_CSUM_NO_ACTION; if (info->attrs[ILA_ATTR_IDENT_TYPE]) xp->ip.ident_type = nla_get_u8( info->attrs[ILA_ATTR_IDENT_TYPE]); else xp->ip.ident_type = ILA_ATYPE_USE_FORMAT; if (info->attrs[ILA_ATTR_IFINDEX]) xp->ifindex = nla_get_s32(info->attrs[ILA_ATTR_IFINDEX]); return 0; } /* Must be called with rcu readlock */ static inline struct ila_map *ila_lookup_wildcards(struct ila_addr *iaddr, int ifindex, struct ila_net *ilan) { struct ila_map *ila; ila = rhashtable_lookup_fast(&ilan->xlat.rhash_table, &iaddr->loc, rht_params); while (ila) { if (!ila_cmp_wildcards(ila, iaddr, ifindex)) return ila; ila = rcu_access_pointer(ila->next); } return NULL; } /* Must be called with rcu readlock */ static inline struct ila_map *ila_lookup_by_params(struct ila_xlat_params *xp, struct ila_net *ilan) { struct ila_map *ila; ila = rhashtable_lookup_fast(&ilan->xlat.rhash_table, &xp->ip.locator_match, rht_params); while (ila) { if (!ila_cmp_params(ila, xp)) return ila; ila = rcu_access_pointer(ila->next); } return NULL; } static inline void ila_release(struct ila_map *ila) { kfree_rcu(ila, rcu); } static void ila_free_node(struct ila_map *ila) { struct ila_map *next; /* Assume rcu_readlock held */ while (ila) { next = rcu_access_pointer(ila->next); ila_release(ila); ila = next; } } static void ila_free_cb(void *ptr, void *arg) { ila_free_node((struct ila_map *)ptr); } static int ila_xlat_addr(struct sk_buff *skb, bool sir2ila); static unsigned int ila_nf_input(void *priv, struct sk_buff *skb, const struct nf_hook_state *state) { ila_xlat_addr(skb, false); return NF_ACCEPT; } static const struct nf_hook_ops ila_nf_hook_ops[] = { { .hook = ila_nf_input, .pf = NFPROTO_IPV6, .hooknum = NF_INET_PRE_ROUTING, .priority = -1, }, }; static int ila_add_mapping(struct net *net, struct ila_xlat_params *xp) { struct ila_net *ilan = net_generic(net, ila_net_id); struct ila_map *ila, *head; spinlock_t *lock = ila_get_lock(ilan, xp->ip.locator_match); int err = 0, order; if (!ilan->xlat.hooks_registered) { /* We defer registering net hooks in the namespace until the * first mapping is added. */ err = nf_register_net_hooks(net, ila_nf_hook_ops, ARRAY_SIZE(ila_nf_hook_ops)); if (err) return err; ilan->xlat.hooks_registered = true; } ila = kzalloc(sizeof(*ila), GFP_KERNEL); if (!ila) return -ENOMEM; ila_init_saved_csum(&xp->ip); ila->xp = *xp; order = ila_order(ila); spin_lock(lock); head = rhashtable_lookup_fast(&ilan->xlat.rhash_table, &xp->ip.locator_match, rht_params); if (!head) { /* New entry for the rhash_table */ err = rhashtable_lookup_insert_fast(&ilan->xlat.rhash_table, &ila->node, rht_params); } else { struct ila_map *tila = head, *prev = NULL; do { if (!ila_cmp_params(tila, xp)) { err = -EEXIST; goto out; } if (order > ila_order(tila)) break; prev = tila; tila = rcu_dereference_protected(tila->next, lockdep_is_held(lock)); } while (tila); if (prev) { /* Insert in sub list of head */ RCU_INIT_POINTER(ila->next, tila); rcu_assign_pointer(prev->next, ila); } else { /* Make this ila new head */ RCU_INIT_POINTER(ila->next, head); err = rhashtable_replace_fast(&ilan->xlat.rhash_table, &head->node, &ila->node, rht_params); if (err) goto out; } } out: spin_unlock(lock); if (err) kfree(ila); return err; } static int ila_del_mapping(struct net *net, struct ila_xlat_params *xp) { struct ila_net *ilan = net_generic(net, ila_net_id); struct ila_map *ila, *head, *prev; spinlock_t *lock = ila_get_lock(ilan, xp->ip.locator_match); int err = -ENOENT; spin_lock(lock); head = rhashtable_lookup_fast(&ilan->xlat.rhash_table, &xp->ip.locator_match, rht_params); ila = head; prev = NULL; while (ila) { if (ila_cmp_params(ila, xp)) { prev = ila; ila = rcu_dereference_protected(ila->next, lockdep_is_held(lock)); continue; } err = 0; if (prev) { /* Not head, just delete from list */ rcu_assign_pointer(prev->next, ila->next); } else { /* It is the head. If there is something in the * sublist we need to make a new head. */ head = rcu_dereference_protected(ila->next, lockdep_is_held(lock)); if (head) { /* Put first entry in the sublist into the * table */ err = rhashtable_replace_fast( &ilan->xlat.rhash_table, &ila->node, &head->node, rht_params); if (err) goto out; } else { /* Entry no longer used */ err = rhashtable_remove_fast( &ilan->xlat.rhash_table, &ila->node, rht_params); } } ila_release(ila); break; } out: spin_unlock(lock); return err; } int ila_xlat_nl_cmd_add_mapping(struct sk_buff *skb, struct genl_info *info) { struct net *net = genl_info_net(info); struct ila_xlat_params p; int err; err = parse_nl_config(info, &p); if (err) return err; return ila_add_mapping(net, &p); } int ila_xlat_nl_cmd_del_mapping(struct sk_buff *skb, struct genl_info *info) { struct net *net = genl_info_net(info); struct ila_xlat_params xp; int err; err = parse_nl_config(info, &xp); if (err) return err; ila_del_mapping(net, &xp); return 0; } static inline spinlock_t *lock_from_ila_map(struct ila_net *ilan, struct ila_map *ila) { return ila_get_lock(ilan, ila->xp.ip.locator_match); } int ila_xlat_nl_cmd_flush(struct sk_buff *skb, struct genl_info *info) { struct net *net = genl_info_net(info); struct ila_net *ilan = net_generic(net, ila_net_id); struct rhashtable_iter iter; struct ila_map *ila; spinlock_t *lock; int ret; ret = rhashtable_walk_init(&ilan->xlat.rhash_table, &iter, GFP_KERNEL); if (ret) goto done; rhashtable_walk_start(&iter); for (;;) { ila = rhashtable_walk_next(&iter); if (IS_ERR(ila)) { if (PTR_ERR(ila) == -EAGAIN) continue; ret = PTR_ERR(ila); goto done; } else if (!ila) { break; } lock = lock_from_ila_map(ilan, ila); spin_lock(lock); ret = rhashtable_remove_fast(&ilan->xlat.rhash_table, &ila->node, rht_params); if (!ret) ila_free_node(ila); spin_unlock(lock); if (ret) break; } done: rhashtable_walk_stop(&iter); rhashtable_walk_exit(&iter); return ret; } static int ila_fill_info(struct ila_map *ila, struct sk_buff *msg) { if (nla_put_u64_64bit(msg, ILA_ATTR_LOCATOR, (__force u64)ila->xp.ip.locator.v64, ILA_ATTR_PAD) || nla_put_u64_64bit(msg, ILA_ATTR_LOCATOR_MATCH, (__force u64)ila->xp.ip.locator_match.v64, ILA_ATTR_PAD) || nla_put_s32(msg, ILA_ATTR_IFINDEX, ila->xp.ifindex) || nla_put_u8(msg, ILA_ATTR_CSUM_MODE, ila->xp.ip.csum_mode) || nla_put_u8(msg, ILA_ATTR_IDENT_TYPE, ila->xp.ip.ident_type)) return -1; return 0; } static int ila_dump_info(struct ila_map *ila, u32 portid, u32 seq, u32 flags, struct sk_buff *skb, u8 cmd) { void *hdr; hdr = genlmsg_put(skb, portid, seq, &ila_nl_family, flags, cmd); if (!hdr) return -ENOMEM; if (ila_fill_info(ila, skb) < 0) goto nla_put_failure; genlmsg_end(skb, hdr); return 0; nla_put_failure: genlmsg_cancel(skb, hdr); return -EMSGSIZE; } int ila_xlat_nl_cmd_get_mapping(struct sk_buff *skb, struct genl_info *info) { struct net *net = genl_info_net(info); struct ila_net *ilan = net_generic(net, ila_net_id); struct sk_buff *msg; struct ila_xlat_params xp; struct ila_map *ila; int ret; ret = parse_nl_config(info, &xp); if (ret) return ret; msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL); if (!msg) return -ENOMEM; rcu_read_lock(); ila = ila_lookup_by_params(&xp, ilan); if (ila) { ret = ila_dump_info(ila, info->snd_portid, info->snd_seq, 0, msg, info->genlhdr->cmd); } rcu_read_unlock(); if (ret < 0) goto out_free; return genlmsg_reply(msg, info); out_free: nlmsg_free(msg); return ret; } struct ila_dump_iter { struct rhashtable_iter rhiter; int skip; }; int ila_xlat_nl_dump_start(struct netlink_callback *cb) { struct net *net = sock_net(cb->skb->sk); struct ila_net *ilan = net_generic(net, ila_net_id); struct ila_dump_iter *iter; int ret; iter = kmalloc(sizeof(*iter), GFP_KERNEL); if (!iter) return -ENOMEM; ret = rhashtable_walk_init(&ilan->xlat.rhash_table, &iter->rhiter, GFP_KERNEL); if (ret) { kfree(iter); return ret; } iter->skip = 0; cb->args[0] = (long)iter; return ret; } int ila_xlat_nl_dump_done(struct netlink_callback *cb) { struct ila_dump_iter *iter = (struct ila_dump_iter *)cb->args[0]; rhashtable_walk_exit(&iter->rhiter); kfree(iter); return 0; } int ila_xlat_nl_dump(struct sk_buff *skb, struct netlink_callback *cb) { struct ila_dump_iter *iter = (struct ila_dump_iter *)cb->args[0]; struct rhashtable_iter *rhiter = &iter->rhiter; int skip = iter->skip; struct ila_map *ila; int ret; rhashtable_walk_start(rhiter); /* Get first entry */ ila = rhashtable_walk_peek(rhiter); if (ila && !IS_ERR(ila) && skip) { /* Skip over visited entries */ while (ila && skip) { /* Skip over any ila entries in this list that we * have already dumped. */ ila = rcu_access_pointer(ila->next); skip--; } } skip = 0; for (;;) { if (IS_ERR(ila)) { ret = PTR_ERR(ila); if (ret == -EAGAIN) { /* Table has changed and iter has reset. Return * -EAGAIN to the application even if we have * written data to the skb. The application * needs to deal with this. */ goto out_ret; } else { break; } } else if (!ila) { ret = 0; break; } while (ila) { ret = ila_dump_info(ila, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq, NLM_F_MULTI, skb, ILA_CMD_GET); if (ret) goto out; skip++; ila = rcu_access_pointer(ila->next); } skip = 0; ila = rhashtable_walk_next(rhiter); } out: iter->skip = skip; ret = (skb->len ? : ret); out_ret: rhashtable_walk_stop(rhiter); return ret; } #define ILA_HASH_TABLE_SIZE 1024 int ila_xlat_init_net(struct net *net) { struct ila_net *ilan = net_generic(net, ila_net_id); int err; err = alloc_ila_locks(ilan); if (err) return err; rhashtable_init(&ilan->xlat.rhash_table, &rht_params); return 0; } void ila_xlat_exit_net(struct net *net) { struct ila_net *ilan = net_generic(net, ila_net_id); rhashtable_free_and_destroy(&ilan->xlat.rhash_table, ila_free_cb, NULL); free_bucket_spinlocks(ilan->xlat.locks); if (ilan->xlat.hooks_registered) nf_unregister_net_hooks(net, ila_nf_hook_ops, ARRAY_SIZE(ila_nf_hook_ops)); } static int ila_xlat_addr(struct sk_buff *skb, bool sir2ila) { struct ila_map *ila; struct ipv6hdr *ip6h = ipv6_hdr(skb); struct net *net = dev_net(skb->dev); struct ila_net *ilan = net_generic(net, ila_net_id); struct ila_addr *iaddr = ila_a2i(&ip6h->daddr); /* Assumes skb contains a valid IPv6 header that is pulled */ /* No check here that ILA type in the mapping matches what is in the * address. We assume that whatever sender gaves us can be translated. * The checksum mode however is relevant. */ rcu_read_lock(); ila = ila_lookup_wildcards(iaddr, skb->dev->ifindex, ilan); if (ila) ila_update_ipv6_locator(skb, &ila->xp.ip, sir2ila); rcu_read_unlock(); return 0; }