661 lines
14 KiB
C
661 lines
14 KiB
C
// SPDX-License-Identifier: GPL-2.0
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#include <linux/jhash.h>
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#include <linux/netfilter.h>
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#include <linux/rcupdate.h>
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#include <linux/rhashtable.h>
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#include <linux/vmalloc.h>
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#include <net/genetlink.h>
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#include <net/ila.h>
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#include <net/netns/generic.h>
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#include <uapi/linux/genetlink.h>
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#include "ila.h"
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struct ila_xlat_params {
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struct ila_params ip;
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int ifindex;
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};
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struct ila_map {
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struct ila_xlat_params xp;
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struct rhash_head node;
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struct ila_map __rcu *next;
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struct rcu_head rcu;
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};
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#define MAX_LOCKS 1024
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#define LOCKS_PER_CPU 10
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static int alloc_ila_locks(struct ila_net *ilan)
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{
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return alloc_bucket_spinlocks(&ilan->xlat.locks, &ilan->xlat.locks_mask,
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MAX_LOCKS, LOCKS_PER_CPU,
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GFP_KERNEL);
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}
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static u32 hashrnd __read_mostly;
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static __always_inline void __ila_hash_secret_init(void)
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{
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net_get_random_once(&hashrnd, sizeof(hashrnd));
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}
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static inline u32 ila_locator_hash(struct ila_locator loc)
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{
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u32 *v = (u32 *)loc.v32;
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__ila_hash_secret_init();
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return jhash_2words(v[0], v[1], hashrnd);
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}
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static inline spinlock_t *ila_get_lock(struct ila_net *ilan,
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struct ila_locator loc)
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{
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return &ilan->xlat.locks[ila_locator_hash(loc) & ilan->xlat.locks_mask];
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}
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static inline int ila_cmp_wildcards(struct ila_map *ila,
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struct ila_addr *iaddr, int ifindex)
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{
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return (ila->xp.ifindex && ila->xp.ifindex != ifindex);
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}
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static inline int ila_cmp_params(struct ila_map *ila,
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struct ila_xlat_params *xp)
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{
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return (ila->xp.ifindex != xp->ifindex);
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}
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static int ila_cmpfn(struct rhashtable_compare_arg *arg,
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const void *obj)
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{
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const struct ila_map *ila = obj;
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return (ila->xp.ip.locator_match.v64 != *(__be64 *)arg->key);
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}
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static inline int ila_order(struct ila_map *ila)
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{
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int score = 0;
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if (ila->xp.ifindex)
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score += 1 << 1;
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return score;
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}
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static const struct rhashtable_params rht_params = {
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.nelem_hint = 1024,
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.head_offset = offsetof(struct ila_map, node),
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.key_offset = offsetof(struct ila_map, xp.ip.locator_match),
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.key_len = sizeof(u64), /* identifier */
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.max_size = 1048576,
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.min_size = 256,
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.automatic_shrinking = true,
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.obj_cmpfn = ila_cmpfn,
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};
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static int parse_nl_config(struct genl_info *info,
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struct ila_xlat_params *xp)
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{
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memset(xp, 0, sizeof(*xp));
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if (info->attrs[ILA_ATTR_LOCATOR])
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xp->ip.locator.v64 = (__force __be64)nla_get_u64(
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info->attrs[ILA_ATTR_LOCATOR]);
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if (info->attrs[ILA_ATTR_LOCATOR_MATCH])
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xp->ip.locator_match.v64 = (__force __be64)nla_get_u64(
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info->attrs[ILA_ATTR_LOCATOR_MATCH]);
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if (info->attrs[ILA_ATTR_CSUM_MODE])
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xp->ip.csum_mode = nla_get_u8(info->attrs[ILA_ATTR_CSUM_MODE]);
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else
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xp->ip.csum_mode = ILA_CSUM_NO_ACTION;
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if (info->attrs[ILA_ATTR_IDENT_TYPE])
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xp->ip.ident_type = nla_get_u8(
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info->attrs[ILA_ATTR_IDENT_TYPE]);
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else
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xp->ip.ident_type = ILA_ATYPE_USE_FORMAT;
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if (info->attrs[ILA_ATTR_IFINDEX])
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xp->ifindex = nla_get_s32(info->attrs[ILA_ATTR_IFINDEX]);
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return 0;
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}
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/* Must be called with rcu readlock */
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static inline struct ila_map *ila_lookup_wildcards(struct ila_addr *iaddr,
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int ifindex,
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struct ila_net *ilan)
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{
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struct ila_map *ila;
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ila = rhashtable_lookup_fast(&ilan->xlat.rhash_table, &iaddr->loc,
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rht_params);
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while (ila) {
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if (!ila_cmp_wildcards(ila, iaddr, ifindex))
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return ila;
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ila = rcu_access_pointer(ila->next);
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}
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return NULL;
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}
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/* Must be called with rcu readlock */
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static inline struct ila_map *ila_lookup_by_params(struct ila_xlat_params *xp,
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struct ila_net *ilan)
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{
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struct ila_map *ila;
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ila = rhashtable_lookup_fast(&ilan->xlat.rhash_table,
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&xp->ip.locator_match,
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rht_params);
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while (ila) {
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if (!ila_cmp_params(ila, xp))
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return ila;
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ila = rcu_access_pointer(ila->next);
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}
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return NULL;
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}
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static inline void ila_release(struct ila_map *ila)
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{
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kfree_rcu(ila, rcu);
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}
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static void ila_free_node(struct ila_map *ila)
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{
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struct ila_map *next;
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/* Assume rcu_readlock held */
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while (ila) {
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next = rcu_access_pointer(ila->next);
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ila_release(ila);
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ila = next;
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}
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}
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static void ila_free_cb(void *ptr, void *arg)
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{
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ila_free_node((struct ila_map *)ptr);
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}
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static int ila_xlat_addr(struct sk_buff *skb, bool sir2ila);
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static unsigned int
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ila_nf_input(void *priv,
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struct sk_buff *skb,
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const struct nf_hook_state *state)
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{
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ila_xlat_addr(skb, false);
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return NF_ACCEPT;
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}
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static const struct nf_hook_ops ila_nf_hook_ops[] = {
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{
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.hook = ila_nf_input,
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.pf = NFPROTO_IPV6,
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.hooknum = NF_INET_PRE_ROUTING,
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.priority = -1,
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},
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};
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static int ila_add_mapping(struct net *net, struct ila_xlat_params *xp)
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{
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struct ila_net *ilan = net_generic(net, ila_net_id);
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struct ila_map *ila, *head;
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spinlock_t *lock = ila_get_lock(ilan, xp->ip.locator_match);
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int err = 0, order;
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if (!ilan->xlat.hooks_registered) {
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/* We defer registering net hooks in the namespace until the
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* first mapping is added.
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*/
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err = nf_register_net_hooks(net, ila_nf_hook_ops,
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ARRAY_SIZE(ila_nf_hook_ops));
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if (err)
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return err;
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ilan->xlat.hooks_registered = true;
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}
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ila = kzalloc(sizeof(*ila), GFP_KERNEL);
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if (!ila)
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return -ENOMEM;
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ila_init_saved_csum(&xp->ip);
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ila->xp = *xp;
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order = ila_order(ila);
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spin_lock(lock);
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head = rhashtable_lookup_fast(&ilan->xlat.rhash_table,
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&xp->ip.locator_match,
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rht_params);
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if (!head) {
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/* New entry for the rhash_table */
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err = rhashtable_lookup_insert_fast(&ilan->xlat.rhash_table,
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&ila->node, rht_params);
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} else {
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struct ila_map *tila = head, *prev = NULL;
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do {
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if (!ila_cmp_params(tila, xp)) {
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err = -EEXIST;
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goto out;
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}
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if (order > ila_order(tila))
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break;
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prev = tila;
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tila = rcu_dereference_protected(tila->next,
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lockdep_is_held(lock));
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} while (tila);
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if (prev) {
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/* Insert in sub list of head */
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RCU_INIT_POINTER(ila->next, tila);
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rcu_assign_pointer(prev->next, ila);
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} else {
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/* Make this ila new head */
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RCU_INIT_POINTER(ila->next, head);
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err = rhashtable_replace_fast(&ilan->xlat.rhash_table,
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&head->node,
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&ila->node, rht_params);
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if (err)
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goto out;
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}
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}
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out:
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spin_unlock(lock);
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if (err)
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kfree(ila);
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return err;
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}
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static int ila_del_mapping(struct net *net, struct ila_xlat_params *xp)
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{
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struct ila_net *ilan = net_generic(net, ila_net_id);
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struct ila_map *ila, *head, *prev;
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spinlock_t *lock = ila_get_lock(ilan, xp->ip.locator_match);
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int err = -ENOENT;
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spin_lock(lock);
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head = rhashtable_lookup_fast(&ilan->xlat.rhash_table,
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&xp->ip.locator_match, rht_params);
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ila = head;
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prev = NULL;
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while (ila) {
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if (ila_cmp_params(ila, xp)) {
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prev = ila;
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ila = rcu_dereference_protected(ila->next,
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lockdep_is_held(lock));
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continue;
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}
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err = 0;
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if (prev) {
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/* Not head, just delete from list */
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rcu_assign_pointer(prev->next, ila->next);
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} else {
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/* It is the head. If there is something in the
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* sublist we need to make a new head.
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*/
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head = rcu_dereference_protected(ila->next,
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lockdep_is_held(lock));
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if (head) {
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/* Put first entry in the sublist into the
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* table
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*/
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err = rhashtable_replace_fast(
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&ilan->xlat.rhash_table, &ila->node,
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&head->node, rht_params);
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if (err)
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goto out;
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} else {
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/* Entry no longer used */
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err = rhashtable_remove_fast(
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&ilan->xlat.rhash_table,
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&ila->node, rht_params);
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}
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}
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ila_release(ila);
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break;
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}
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out:
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spin_unlock(lock);
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return err;
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}
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int ila_xlat_nl_cmd_add_mapping(struct sk_buff *skb, struct genl_info *info)
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{
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struct net *net = genl_info_net(info);
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struct ila_xlat_params p;
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int err;
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err = parse_nl_config(info, &p);
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if (err)
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return err;
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return ila_add_mapping(net, &p);
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}
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int ila_xlat_nl_cmd_del_mapping(struct sk_buff *skb, struct genl_info *info)
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{
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struct net *net = genl_info_net(info);
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struct ila_xlat_params xp;
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int err;
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err = parse_nl_config(info, &xp);
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if (err)
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return err;
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ila_del_mapping(net, &xp);
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return 0;
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}
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static inline spinlock_t *lock_from_ila_map(struct ila_net *ilan,
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struct ila_map *ila)
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{
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return ila_get_lock(ilan, ila->xp.ip.locator_match);
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}
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int ila_xlat_nl_cmd_flush(struct sk_buff *skb, struct genl_info *info)
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{
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struct net *net = genl_info_net(info);
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struct ila_net *ilan = net_generic(net, ila_net_id);
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struct rhashtable_iter iter;
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struct ila_map *ila;
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spinlock_t *lock;
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int ret = 0;
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rhashtable_walk_enter(&ilan->xlat.rhash_table, &iter);
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rhashtable_walk_start(&iter);
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for (;;) {
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ila = rhashtable_walk_next(&iter);
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if (IS_ERR(ila)) {
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if (PTR_ERR(ila) == -EAGAIN)
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continue;
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ret = PTR_ERR(ila);
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goto done;
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} else if (!ila) {
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break;
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}
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lock = lock_from_ila_map(ilan, ila);
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spin_lock(lock);
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ret = rhashtable_remove_fast(&ilan->xlat.rhash_table,
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&ila->node, rht_params);
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if (!ret)
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ila_free_node(ila);
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spin_unlock(lock);
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if (ret)
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break;
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}
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done:
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rhashtable_walk_stop(&iter);
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rhashtable_walk_exit(&iter);
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return ret;
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}
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static int ila_fill_info(struct ila_map *ila, struct sk_buff *msg)
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{
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if (nla_put_u64_64bit(msg, ILA_ATTR_LOCATOR,
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(__force u64)ila->xp.ip.locator.v64,
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ILA_ATTR_PAD) ||
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nla_put_u64_64bit(msg, ILA_ATTR_LOCATOR_MATCH,
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(__force u64)ila->xp.ip.locator_match.v64,
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ILA_ATTR_PAD) ||
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nla_put_s32(msg, ILA_ATTR_IFINDEX, ila->xp.ifindex) ||
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nla_put_u8(msg, ILA_ATTR_CSUM_MODE, ila->xp.ip.csum_mode) ||
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nla_put_u8(msg, ILA_ATTR_IDENT_TYPE, ila->xp.ip.ident_type))
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return -1;
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return 0;
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}
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static int ila_dump_info(struct ila_map *ila,
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u32 portid, u32 seq, u32 flags,
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struct sk_buff *skb, u8 cmd)
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{
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void *hdr;
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hdr = genlmsg_put(skb, portid, seq, &ila_nl_family, flags, cmd);
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if (!hdr)
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return -ENOMEM;
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if (ila_fill_info(ila, skb) < 0)
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goto nla_put_failure;
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genlmsg_end(skb, hdr);
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return 0;
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nla_put_failure:
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genlmsg_cancel(skb, hdr);
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return -EMSGSIZE;
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}
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int ila_xlat_nl_cmd_get_mapping(struct sk_buff *skb, struct genl_info *info)
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{
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struct net *net = genl_info_net(info);
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struct ila_net *ilan = net_generic(net, ila_net_id);
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struct sk_buff *msg;
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struct ila_xlat_params xp;
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struct ila_map *ila;
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int ret;
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ret = parse_nl_config(info, &xp);
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if (ret)
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return ret;
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msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
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if (!msg)
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return -ENOMEM;
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rcu_read_lock();
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ret = -ESRCH;
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ila = ila_lookup_by_params(&xp, ilan);
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if (ila) {
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ret = ila_dump_info(ila,
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info->snd_portid,
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info->snd_seq, 0, msg,
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info->genlhdr->cmd);
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}
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rcu_read_unlock();
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if (ret < 0)
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goto out_free;
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return genlmsg_reply(msg, info);
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out_free:
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nlmsg_free(msg);
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return ret;
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}
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struct ila_dump_iter {
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struct rhashtable_iter rhiter;
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int skip;
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};
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int ila_xlat_nl_dump_start(struct netlink_callback *cb)
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{
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struct net *net = sock_net(cb->skb->sk);
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struct ila_net *ilan = net_generic(net, ila_net_id);
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struct ila_dump_iter *iter;
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iter = kmalloc(sizeof(*iter), GFP_KERNEL);
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if (!iter)
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return -ENOMEM;
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rhashtable_walk_enter(&ilan->xlat.rhash_table, &iter->rhiter);
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iter->skip = 0;
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cb->args[0] = (long)iter;
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return 0;
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}
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int ila_xlat_nl_dump_done(struct netlink_callback *cb)
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{
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struct ila_dump_iter *iter = (struct ila_dump_iter *)cb->args[0];
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rhashtable_walk_exit(&iter->rhiter);
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kfree(iter);
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return 0;
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}
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int ila_xlat_nl_dump(struct sk_buff *skb, struct netlink_callback *cb)
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{
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struct ila_dump_iter *iter = (struct ila_dump_iter *)cb->args[0];
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struct rhashtable_iter *rhiter = &iter->rhiter;
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int skip = iter->skip;
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struct ila_map *ila;
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int ret;
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|
|
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;
|
|
}
|
|
|
|
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;
|
|
|
|
err = rhashtable_init(&ilan->xlat.rhash_table, &rht_params);
|
|
if (err) {
|
|
free_bucket_spinlocks(ilan->xlat.locks);
|
|
return err;
|
|
}
|
|
|
|
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;
|
|
}
|