This patch set up a hook for xfrm6_xlat_addr. This provides a way to
perform ILA translation before early demux which can be a significant
performance advantage over LWT which would occur later.
The implementation entails a rhashtable which is used to do the locator
lookup. The rhash table is configured via new netlink commands.
Signed-off-by: Tom Herbert <t...@herbertland.com>
---
include/uapi/linux/ila.h | 22 ++
net/ipv6/Kconfig | 1 +
net/ipv6/ila/Makefile | 2 +-
net/ipv6/ila/ila.h | 2 +
net/ipv6/ila/ila_common.c | 8 +
net/ipv6/ila/ila_xlat.c | 642 ++++++++++++++++++++++++++++++++++++++++++++++
6 files changed, 676 insertions(+), 1 deletion(-)
create mode 100644 net/ipv6/ila/ila_xlat.c
diff --git a/include/uapi/linux/ila.h b/include/uapi/linux/ila.h
index 7ed9e67..abde7bb 100644
--- a/include/uapi/linux/ila.h
+++ b/include/uapi/linux/ila.h
@@ -3,13 +3,35 @@
#ifndef _UAPI_LINUX_ILA_H
#define _UAPI_LINUX_ILA_H
+/* NETLINK_GENERIC related info */
+#define ILA_GENL_NAME "ila"
+#define ILA_GENL_VERSION 0x1
+
enum {
ILA_ATTR_UNSPEC,
ILA_ATTR_LOCATOR, /* u64 */
+ ILA_ATTR_IDENTIFIER, /* u64 */
+ ILA_ATTR_LOCATOR_MATCH, /* u64 */
+ ILA_ATTR_IFINDEX, /* s32 */
+ ILA_ATTR_DIR, /* u32 */
__ILA_ATTR_MAX,
};
#define ILA_ATTR_MAX (__ILA_ATTR_MAX - 1)
+enum {
+ ILA_CMD_UNSPEC,
+ ILA_CMD_ADD,
+ ILA_CMD_DEL,
+ ILA_CMD_GET,
+
+ __ILA_CMD_MAX,
+};
+
+#define ILA_CMD_MAX (__ILA_CMD_MAX - 1)
+
+#define ILA_DIR_IN (1 << 0)
+#define ILA_DIR_OUT (1 << 1)
+
#endif /* _UAPI_LINUX_ILA_H */
diff --git a/net/ipv6/Kconfig b/net/ipv6/Kconfig
index 6e8ca06..c972497 100644
--- a/net/ipv6/Kconfig
+++ b/net/ipv6/Kconfig
@@ -95,6 +95,7 @@ config IPV6_MIP6
config IPV6_ILA
tristate "IPv6: Identifier Locator Addressing (ILA)"
select LWTUNNEL
+ select INET6_XFRM_XLAT_ADDR
---help---
Support for IPv6 Identifier Locator Addressing (ILA).
diff --git a/net/ipv6/ila/Makefile b/net/ipv6/ila/Makefile
index 31d136b..4b32e59 100644
--- a/net/ipv6/ila/Makefile
+++ b/net/ipv6/ila/Makefile
@@ -4,4 +4,4 @@
obj-$(CONFIG_IPV6_ILA) += ila.o
-ila-objs := ila_common.o ila_lwt.o
+ila-objs := ila_common.o ila_lwt.o ila_xlat.o
diff --git a/net/ipv6/ila/ila.h b/net/ipv6/ila/ila.h
index b94081f..28542cb 100644
--- a/net/ipv6/ila/ila.h
+++ b/net/ipv6/ila/ila.h
@@ -42,5 +42,7 @@ void update_ipv6_locator(struct sk_buff *skb, struct
ila_params *p);
int ila_lwt_init(void);
void ila_lwt_fini(void);
+int ila_xlat_init(void);
+void ila_xlat_fini(void);
#endif /* __ILA_H */
diff --git a/net/ipv6/ila/ila_common.c b/net/ipv6/ila/ila_common.c
index 1a1e1e0..cde7b96 100644
--- a/net/ipv6/ila/ila_common.c
+++ b/net/ipv6/ila/ila_common.c
@@ -80,12 +80,20 @@ static int __init ila_init(void)
if (ret)
goto fail_lwt;
+ ret = ila_xlat_init();
+ if (ret)
+ goto fail_xlat;
+
+ return 0;
+fail_xlat:
+ ila_lwt_fini();
fail_lwt:
return ret;
}
static void __exit ila_fini(void)
{
+ ila_xlat_fini();
ila_lwt_fini();
}
diff --git a/net/ipv6/ila/ila_xlat.c b/net/ipv6/ila/ila_xlat.c
new file mode 100644
index 0000000..cd6135b
--- /dev/null
+++ b/net/ipv6/ila/ila_xlat.c
@@ -0,0 +1,642 @@
+#include <linux/jhash.h>
+#include <linux/netfilter.h>
+#include <linux/rcupdate.h>
+#include <linux/rhashtable.h>
+#include <linux/vmalloc.h>
+#include <net/genetlink.h>
+#include <net/netns/generic.h>
+#include <net/xfrm.h>
+#include <uapi/linux/genetlink.h>
+#include "ila.h"
+
+struct ila_xlat_params {
+ struct ila_params ip;
+ __be64 identifier;
+ int ifindex;
+ unsigned int dir;
+};
+
+struct ila_map {
+ struct ila_xlat_params p;
+ struct rhash_head node;
+ struct ila_map *next;
+ struct rcu_head rcu;
+};
+
+static unsigned int ila_net_id;
+
+struct ila_net {
+ struct rhashtable rhash_table;
+ spinlock_t *locks; /* Bucket locks for entry manipulation */
+ unsigned int locks_mask;
+};
+
+#define LOCKS_PER_CPU 10
+
+static int alloc_ila_locks(struct ila_net *ilan, gfp_t gfp)
+{
+ unsigned int i, size;
+ unsigned int nr_pcpus = num_possible_cpus();
+
+ nr_pcpus = min_t(unsigned int, nr_pcpus, 32UL);
+ size = roundup_pow_of_two(nr_pcpus * LOCKS_PER_CPU);
+
+ if (sizeof(spinlock_t) != 0) {
+#ifdef CONFIG_NUMA
+ if (size * sizeof(spinlock_t) > PAGE_SIZE &&
+ gfp == GFP_KERNEL)
+ ilan->locks = vmalloc(size * sizeof(spinlock_t));
+ else
+#endif
+ ilan->locks = kmalloc_array(size, sizeof(spinlock_t),
+ gfp);
+ if (!ilan->locks)
+ return -ENOMEM;
+ for (i = 0; i < size; i++)
+ spin_lock_init(&ilan->locks[i]);
+ }
+ ilan->locks_mask = size - 1;
+
+ return 0;
+}
+
+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_identifier_hash(__be64 identifier)
+{
+ u32 *v = (u32 *)&identifier;
+
+ return jhash_2words(v[0], v[1], hashrnd);
+}
+
+static inline spinlock_t *ila_get_lock(struct ila_net *ilan, __be64 identifier)
+{
+ return &ilan->locks[ila_identifier_hash(identifier) & ilan->locks_mask];
+}
+
+static inline int ila_cmp_wildcards(struct ila_map *ila, __be64 loc,
+ int ifindex, unsigned int dir)
+{
+ return (ila->p.ip.locator_match && ila->p.ip.locator_match != loc) ||
+ (ila->p.ifindex && ila->p.ifindex != ifindex) ||
+ !(ila->p.dir & dir);
+}
+
+static inline int ila_cmp_params(struct ila_map *ila, struct ila_xlat_params
*p)
+{
+ return (ila->p.ip.locator_match != p->ip.locator_match) ||
+ (ila->p.ifindex != p->ifindex) ||
+ (ila->p.dir != p->dir);
+}
+
+static int ila_cmpfn(struct rhashtable_compare_arg *arg,
+ const void *obj)
+{
+ const struct ila_map *ila = obj;
+
+ return (ila->p.identifier != *(__be64 *)arg->key);
+}
+
+static inline int ila_order(struct ila_map *ila)
+{
+ int score = 0;
+
+ if (ila->p.ip.locator_match)
+ score += 1 << 0;
+
+ if (ila->p.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, p.identifier),
+ .key_len = sizeof(u64), /* identifier */
+ .max_size = 1048576,
+ .min_size = 256,
+ .automatic_shrinking = true,
+ .obj_cmpfn = ila_cmpfn,
+};
+
+static struct genl_family ila_nl_family = {
+ .id = GENL_ID_GENERATE,
+ .hdrsize = 0,
+ .name = ILA_GENL_NAME,
+ .version = ILA_GENL_VERSION,
+ .maxattr = ILA_ATTR_MAX,
+ .netnsok = true,
+ .parallel_ops = true,
+};
+
+static struct nla_policy ila_nl_policy[ILA_ATTR_MAX + 1] = {
+ [ILA_ATTR_IDENTIFIER] = { .type = NLA_U64, },
+ [ILA_ATTR_LOCATOR] = { .type = NLA_U64, },
+ [ILA_ATTR_LOCATOR_MATCH] = { .type = NLA_U64, },
+ [ILA_ATTR_IFINDEX] = { .type = NLA_U32, },
+ [ILA_ATTR_DIR] = { .type = NLA_U32, },
+};
+
+static int parse_nl_config(struct genl_info *info,
+ struct ila_xlat_params *p)
+{
+ memset(p, 0, sizeof(*p));
+
+ if (info->attrs[ILA_ATTR_IDENTIFIER])
+ p->identifier = (__force __be64)nla_get_u64(
+ info->attrs[ILA_ATTR_IDENTIFIER]);
+
+ if (info->attrs[ILA_ATTR_LOCATOR])
+ p->ip.locator = (__force __be64)nla_get_u64(
+ info->attrs[ILA_ATTR_LOCATOR]);
+
+ if (info->attrs[ILA_ATTR_LOCATOR_MATCH])
+ p->ip.locator_match = (__force __be64)nla_get_u64(
+ info->attrs[ILA_ATTR_LOCATOR_MATCH]);
+
+ if (info->attrs[ILA_ATTR_IFINDEX])
+ p->ifindex = nla_get_s32(info->attrs[ILA_ATTR_IFINDEX]);
+
+ if (info->attrs[ILA_ATTR_DIR])
+ p->dir = nla_get_u32(info->attrs[ILA_ATTR_DIR]);
+
+ return 0;
+}
+
+/* Must be called with rcu readlock */
+static inline struct ila_map *ila_lookup_wildcards(__be64 id, __be64 loc,
+ int ifindex,
+ unsigned int dir,
+ struct ila_net *ilan)
+{
+ struct ila_map *ila;
+
+ ila = rhashtable_lookup_fast(&ilan->rhash_table, &id, rht_params);
+ while (ila) {
+ if (!ila_cmp_wildcards(ila, loc, ifindex, dir))
+ 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 *p,
+ struct ila_net *ilan)
+{
+ struct ila_map *ila;
+
+ ila = rhashtable_lookup_fast(&ilan->rhash_table, &p->identifier,
+ rht_params);
+ while (ila) {
+ if (!ila_cmp_params(ila, p))
+ 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_cb(void *ptr, void *arg)
+{
+ struct ila_map *ila = (struct ila_map *)ptr, *next;
+
+ /* Assume rcu_readlock held */
+ while (ila) {
+ next = rcu_access_pointer(ila->next);
+ ila_release(ila);
+ ila = next;
+ }
+}
+
+static int ila_add_mapping(struct net *net, struct ila_xlat_params *p)
+{
+ struct ila_net *ilan = net_generic(net, ila_net_id);
+ struct ila_map *ila, *head;
+ spinlock_t *lock = ila_get_lock(ilan, p->identifier);
+ int err = 0, order;
+
+ ila = kzalloc(sizeof(*ila), GFP_KERNEL);
+ if (!ila)
+ return -ENOMEM;
+
+ ila->p = *p;
+
+ if (p->ip.locator_match) {
+ /* Precompute checksum difference for translation since we
+ * know both the old identifier and the new one.
+ */
+ ila->p.ip.csum_diff = compute_csum_diff8(
+ (__be32 *)&p->ip.locator_match,
+ (__be32 *)&p->ip.locator);
+ }
+
+ order = ila_order(ila);
+
+ spin_lock(lock);
+
+ head = rhashtable_lookup_fast(&ilan->rhash_table, &p->identifier,
+ rht_params);
+ if (!head) {
+ /* New entry for the rhash_table */
+ err = rhashtable_lookup_insert_fast(&ilan->rhash_table,
+ &ila->node, rht_params);
+ } else {
+ struct ila_map *tila = head, *prev = NULL;
+
+ do {
+ if (!ila_cmp_params(tila, p)) {
+ 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->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 *p)
+{
+ struct ila_net *ilan = net_generic(net, ila_net_id);
+ struct ila_map *ila, *head, *prev;
+ spinlock_t *lock = ila_get_lock(ilan, p->identifier);
+ int err = -ENOENT;
+
+ spin_lock(lock);
+
+ head = rhashtable_lookup_fast(&ilan->rhash_table,
+ &p->identifier, rht_params);
+ ila = head;
+
+ prev = NULL;
+
+ while (ila) {
+ if (ila_cmp_params(ila, p)) {
+ 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->rhash_table, &ila->node,
+ &head->node, rht_params);
+ if (err)
+ goto out;
+ } else {
+ /* Entry no longer used */
+ err = rhashtable_remove_fast(&ilan->rhash_table,
+ &ila->node,
+ rht_params);
+ }
+ }
+
+ ila_release(ila);
+
+ break;
+ }
+
+out:
+ spin_unlock(lock);
+
+ return err;
+}
+
+static int ila_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);
+}
+
+static int ila_nl_cmd_del_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;
+
+ ila_del_mapping(net, &p);
+
+ return 0;
+}
+
+static int ila_fill_info(struct ila_map *ila, struct sk_buff *msg)
+{
+ if (nla_put_u64(msg, ILA_ATTR_IDENTIFIER,
+ (__force u64)ila->p.identifier) ||
+ nla_put_u64(msg, ILA_ATTR_LOCATOR,
+ (__force u64)ila->p.ip.locator) ||
+ nla_put_u64(msg, ILA_ATTR_LOCATOR_MATCH,
+ (__force u64)ila->p.ip.locator_match) ||
+ nla_put_s32(msg, ILA_ATTR_IFINDEX, ila->p.ifindex) ||
+ nla_put_u32(msg, ILA_ATTR_DIR, ila->p.dir))
+ 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;
+}
+
+static int ila_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 p;
+ struct ila_map *ila;
+ int ret;
+
+ ret = parse_nl_config(info, &p);
+ if (ret)
+ return ret;
+
+ msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
+ if (!msg)
+ return -ENOMEM;
+
+ rcu_read_lock();
+
+ ila = ila_lookup_by_params(&p, 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;
+};
+
+static int ila_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 = (struct ila_dump_iter *)cb->args;
+
+ return rhashtable_walk_init(&ilan->rhash_table, &iter->rhiter);
+}
+
+static int ila_nl_dump_done(struct netlink_callback *cb)
+{
+ struct ila_dump_iter *iter = (struct ila_dump_iter *)cb->args;
+
+ rhashtable_walk_exit(&iter->rhiter);
+
+ return 0;
+}
+
+static int ila_nl_dump(struct sk_buff *skb, struct netlink_callback *cb)
+{
+ struct ila_dump_iter *iter = (struct ila_dump_iter *)cb->args;
+ struct rhashtable_iter *rhiter = &iter->rhiter;
+ struct ila_map *ila;
+ int ret;
+
+ ret = rhashtable_walk_start(rhiter);
+ if (ret && ret != -EAGAIN)
+ goto done;
+
+ for (;;) {
+ ila = rhashtable_walk_next(rhiter);
+
+ if (IS_ERR(ila)) {
+ if (PTR_ERR(ila) == -EAGAIN)
+ continue;
+ ret = PTR_ERR(ila);
+ goto done;
+ } else if (!ila) {
+ 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 done;
+
+ ila = rcu_access_pointer(ila->next);
+ }
+ }
+
+ ret = skb->len;
+
+done:
+ rhashtable_walk_stop(rhiter);
+ return ret;
+}
+
+static const struct genl_ops ila_nl_ops[] = {
+ {
+ .cmd = ILA_CMD_ADD,
+ .doit = ila_nl_cmd_add_mapping,
+ .policy = ila_nl_policy,
+ .flags = GENL_ADMIN_PERM,
+ },
+ {
+ .cmd = ILA_CMD_DEL,
+ .doit = ila_nl_cmd_del_mapping,
+ .policy = ila_nl_policy,
+ .flags = GENL_ADMIN_PERM,
+ },
+ {
+ .cmd = ILA_CMD_GET,
+ .doit = ila_nl_cmd_get_mapping,
+ .start = ila_nl_dump_start,
+ .dumpit = ila_nl_dump,
+ .done = ila_nl_dump_done,
+ .policy = ila_nl_policy,
+ },
+};
+
+#define ILA_HASH_TABLE_SIZE 1024
+
+static __net_init int ila_init_net(struct net *net)
+{
+ int err;
+ struct ila_net *ilan = net_generic(net, ila_net_id);
+
+ err = alloc_ila_locks(ilan, GFP_KERNEL);
+ if (err)
+ return err;
+
+ rhashtable_init(&ilan->rhash_table, &rht_params);
+
+ return 0;
+}
+
+static __net_exit void ila_exit_net(struct net *net)
+{
+ struct ila_net *ilan = net_generic(net, ila_net_id);
+
+ rhashtable_free_and_destroy(&ilan->rhash_table, ila_free_cb, NULL);
+
+ kvfree(ilan->locks);
+}
+
+static struct pernet_operations ila_net_ops = {
+ .init = ila_init_net,
+ .exit = ila_exit_net,
+ .id = &ila_net_id,
+ .size = sizeof(struct ila_net),
+};
+
+static int ila_xlat_addr_in(struct sk_buff *skb)
+{
+ 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);
+ __be64 identifier, locator_match;
+ size_t nhoff;
+
+ /* Assumes skb contains a valid IPv6 header that is pulled */
+
+ identifier = *(__be64 *)&ip6h->daddr.in6_u.u6_addr8[8];
+ locator_match = *(__be64 *)&ip6h->daddr.in6_u.u6_addr8[0];
+ nhoff = sizeof(struct ipv6hdr);
+
+ rcu_read_lock();
+
+ ila = ila_lookup_wildcards(identifier, locator_match,
+ skb->dev->ifindex, ILA_DIR_IN, ilan);
+ if (ila)
+ update_ipv6_locator(skb, &ila->p.ip);
+
+ rcu_read_unlock();
+
+ return 0;
+}
+
+struct xfrm6_xlat_addr ila_xlat = {
+ .xlat = ila_xlat_addr_in,
+};
+
+int ila_xlat_init(void)
+{
+ int ret;
+
+ ret = register_pernet_device(&ila_net_ops);
+ if (ret)
+ goto exit;
+
+ ret = genl_register_family_with_ops(&ila_nl_family,
+ ila_nl_ops);
+ if (ret < 0)
+ goto unregister;
+
+ xfrm6_xlat_addr_add(&ila_xlat);
+
+ return 0;
+
+unregister:
+ unregister_pernet_device(&ila_net_ops);
+exit:
+ return ret;
+}
+
+void ila_xlat_fini(void)
+{
+ int i;
+
+ xfrm6_xlat_addr_del(&ila_xlat);
+ genl_unregister_family(&ila_nl_family);
+ unregister_pernet_device(&ila_net_ops);
+}
+
--
2.4.6
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