aboutsummaryrefslogtreecommitdiffstats
diff options
context:
space:
mode:
Diffstat
-rw-r--r--include/linux/bpf.h7
-rw-r--r--include/linux/bpf_types.h1
-rw-r--r--include/trace/events/xdp.h3
-rw-r--r--include/uapi/linux/bpf.h1
-rw-r--r--kernel/bpf/devmap.c200
-rw-r--r--kernel/bpf/verifier.c2
-rw-r--r--net/core/filter.c9
7 files changed, 220 insertions, 3 deletions
diff --git a/include/linux/bpf.h b/include/linux/bpf.h
index bfdb54dd2ad1..f9a506147c8a 100644
--- a/include/linux/bpf.h
+++ b/include/linux/bpf.h
@@ -713,6 +713,7 @@ struct xdp_buff;
struct sk_buff;
struct bpf_dtab_netdev *__dev_map_lookup_elem(struct bpf_map *map, u32 key);
+struct bpf_dtab_netdev *__dev_map_hash_lookup_elem(struct bpf_map *map, u32 key);
void __dev_map_flush(struct bpf_map *map);
int dev_map_enqueue(struct bpf_dtab_netdev *dst, struct xdp_buff *xdp,
struct net_device *dev_rx);
@@ -799,6 +800,12 @@ static inline struct net_device *__dev_map_lookup_elem(struct bpf_map *map,
return NULL;
}
+static inline struct net_device *__dev_map_hash_lookup_elem(struct bpf_map *map,
+ u32 key)
+{
+ return NULL;
+}
+
static inline void __dev_map_flush(struct bpf_map *map)
{
}
diff --git a/include/linux/bpf_types.h b/include/linux/bpf_types.h
index eec5aeeeaf92..36a9c2325176 100644
--- a/include/linux/bpf_types.h
+++ b/include/linux/bpf_types.h
@@ -62,6 +62,7 @@ BPF_MAP_TYPE(BPF_MAP_TYPE_ARRAY_OF_MAPS, array_of_maps_map_ops)
BPF_MAP_TYPE(BPF_MAP_TYPE_HASH_OF_MAPS, htab_of_maps_map_ops)
#ifdef CONFIG_NET
BPF_MAP_TYPE(BPF_MAP_TYPE_DEVMAP, dev_map_ops)
+BPF_MAP_TYPE(BPF_MAP_TYPE_DEVMAP_HASH, dev_map_hash_ops)
BPF_MAP_TYPE(BPF_MAP_TYPE_SK_STORAGE, sk_storage_map_ops)
#if defined(CONFIG_BPF_STREAM_PARSER)
BPF_MAP_TYPE(BPF_MAP_TYPE_SOCKMAP, sock_map_ops)
diff --git a/include/trace/events/xdp.h b/include/trace/events/xdp.h
index 68899fdc985b..8c8420230a10 100644
--- a/include/trace/events/xdp.h
+++ b/include/trace/events/xdp.h
@@ -175,7 +175,8 @@ struct _bpf_dtab_netdev {
#endif /* __DEVMAP_OBJ_TYPE */
#define devmap_ifindex(fwd, map) \
- ((map->map_type == BPF_MAP_TYPE_DEVMAP) ? \
+ ((map->map_type == BPF_MAP_TYPE_DEVMAP || \
+ map->map_type == BPF_MAP_TYPE_DEVMAP_HASH) ? \
((struct _bpf_dtab_netdev *)fwd)->dev->ifindex : 0)
#define _trace_xdp_redirect_map(dev, xdp, fwd, map, idx) \
diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h
index e985f07a98ed..6bbef0c7f585 100644
--- a/include/uapi/linux/bpf.h
+++ b/include/uapi/linux/bpf.h
@@ -134,6 +134,7 @@ enum bpf_map_type {
BPF_MAP_TYPE_QUEUE,
BPF_MAP_TYPE_STACK,
BPF_MAP_TYPE_SK_STORAGE,
+ BPF_MAP_TYPE_DEVMAP_HASH,
};
/* Note that tracing related programs such as
diff --git a/kernel/bpf/devmap.c b/kernel/bpf/devmap.c
index a0501266bdb8..9af048a932b5 100644
--- a/kernel/bpf/devmap.c
+++ b/kernel/bpf/devmap.c
@@ -37,6 +37,12 @@
* notifier hook walks the map we know that new dev references can not be
* added by the user because core infrastructure ensures dev_get_by_index()
* calls will fail at this point.
+ *
+ * The devmap_hash type is a map type which interprets keys as ifindexes and
+ * indexes these using a hashmap. This allows maps that use ifindex as key to be
+ * densely packed instead of having holes in the lookup array for unused
+ * ifindexes. The setup and packet enqueue/send code is shared between the two
+ * types of devmap; only the lookup and insertion is different.
*/
#include <linux/bpf.h>
#include <net/xdp.h>
@@ -59,6 +65,7 @@ struct xdp_bulk_queue {
struct bpf_dtab_netdev {
struct net_device *dev; /* must be first member, due to tracepoint */
+ struct hlist_node index_hlist;
struct bpf_dtab *dtab;
struct xdp_bulk_queue __percpu *bulkq;
struct rcu_head rcu;
@@ -70,11 +77,30 @@ struct bpf_dtab {
struct bpf_dtab_netdev **netdev_map;
struct list_head __percpu *flush_list;
struct list_head list;
+
+ /* these are only used for DEVMAP_HASH type maps */
+ struct hlist_head *dev_index_head;
+ spinlock_t index_lock;
+ unsigned int items;
+ u32 n_buckets;
};
static DEFINE_SPINLOCK(dev_map_lock);
static LIST_HEAD(dev_map_list);
+static struct hlist_head *dev_map_create_hash(unsigned int entries)
+{
+ int i;
+ struct hlist_head *hash;
+
+ hash = kmalloc_array(entries, sizeof(*hash), GFP_KERNEL);
+ if (hash != NULL)
+ for (i = 0; i < entries; i++)
+ INIT_HLIST_HEAD(&hash[i]);
+
+ return hash;
+}
+
static int dev_map_init_map(struct bpf_dtab *dtab, union bpf_attr *attr)
{
int err, cpu;
@@ -97,6 +123,14 @@ static int dev_map_init_map(struct bpf_dtab *dtab, union bpf_attr *attr)
cost = (u64) dtab->map.max_entries * sizeof(struct bpf_dtab_netdev *);
cost += sizeof(struct list_head) * num_possible_cpus();
+ if (attr->map_type == BPF_MAP_TYPE_DEVMAP_HASH) {
+ dtab->n_buckets = roundup_pow_of_two(dtab->map.max_entries);
+
+ if (!dtab->n_buckets) /* Overflow check */
+ return -EINVAL;
+ cost += sizeof(struct hlist_head) * dtab->n_buckets;
+ }
+
/* if map size is larger than memlock limit, reject it */
err = bpf_map_charge_init(&dtab->map.memory, cost);
if (err)
@@ -115,8 +149,18 @@ static int dev_map_init_map(struct bpf_dtab *dtab, union bpf_attr *attr)
if (!dtab->netdev_map)
goto free_percpu;
+ if (attr->map_type == BPF_MAP_TYPE_DEVMAP_HASH) {
+ dtab->dev_index_head = dev_map_create_hash(dtab->n_buckets);
+ if (!dtab->dev_index_head)
+ goto free_map_area;
+
+ spin_lock_init(&dtab->index_lock);
+ }
+
return 0;
+free_map_area:
+ bpf_map_area_free(dtab->netdev_map);
free_percpu:
free_percpu(dtab->flush_list);
free_charge:
@@ -198,6 +242,7 @@ static void dev_map_free(struct bpf_map *map)
free_percpu(dtab->flush_list);
bpf_map_area_free(dtab->netdev_map);
+ kfree(dtab->dev_index_head);
kfree(dtab);
}
@@ -218,6 +263,70 @@ static int dev_map_get_next_key(struct bpf_map *map, void *key, void *next_key)
return 0;
}
+static inline struct hlist_head *dev_map_index_hash(struct bpf_dtab *dtab,
+ int idx)
+{
+ return &dtab->dev_index_head[idx & (dtab->n_buckets - 1)];
+}
+
+struct bpf_dtab_netdev *__dev_map_hash_lookup_elem(struct bpf_map *map, u32 key)
+{
+ struct bpf_dtab *dtab = container_of(map, struct bpf_dtab, map);
+ struct hlist_head *head = dev_map_index_hash(dtab, key);
+ struct bpf_dtab_netdev *dev;
+
+ hlist_for_each_entry_rcu(dev, head, index_hlist)
+ if (dev->idx == key)
+ return dev;
+
+ return NULL;
+}
+
+static int dev_map_hash_get_next_key(struct bpf_map *map, void *key,
+ void *next_key)
+{
+ struct bpf_dtab *dtab = container_of(map, struct bpf_dtab, map);
+ u32 idx, *next = next_key;
+ struct bpf_dtab_netdev *dev, *next_dev;
+ struct hlist_head *head;
+ int i = 0;
+
+ if (!key)
+ goto find_first;
+
+ idx = *(u32 *)key;
+
+ dev = __dev_map_hash_lookup_elem(map, idx);
+ if (!dev)
+ goto find_first;
+
+ next_dev = hlist_entry_safe(rcu_dereference_raw(hlist_next_rcu(&dev->index_hlist)),
+ struct bpf_dtab_netdev, index_hlist);
+
+ if (next_dev) {
+ *next = next_dev->idx;
+ return 0;
+ }
+
+ i = idx & (dtab->n_buckets - 1);
+ i++;
+
+ find_first:
+ for (; i < dtab->n_buckets; i++) {
+ head = dev_map_index_hash(dtab, i);
+
+ next_dev = hlist_entry_safe(rcu_dereference_raw(hlist_first_rcu(head)),
+ struct bpf_dtab_netdev,
+ index_hlist);
+ if (next_dev) {
+ *next = next_dev->idx;
+ return 0;
+ }
+ }
+
+ return -ENOENT;
+}
+
static int bq_xmit_all(struct xdp_bulk_queue *bq, u32 flags,
bool in_napi_ctx)
{
@@ -373,6 +482,15 @@ static void *dev_map_lookup_elem(struct bpf_map *map, void *key)
return dev ? &dev->ifindex : NULL;
}
+static void *dev_map_hash_lookup_elem(struct bpf_map *map, void *key)
+{
+ struct bpf_dtab_netdev *obj = __dev_map_hash_lookup_elem(map,
+ *(u32 *)key);
+ struct net_device *dev = obj ? obj->dev : NULL;
+
+ return dev ? &dev->ifindex : NULL;
+}
+
static void dev_map_flush_old(struct bpf_dtab_netdev *dev)
{
if (dev->dev->netdev_ops->ndo_xdp_xmit) {
@@ -422,6 +540,28 @@ static int dev_map_delete_elem(struct bpf_map *map, void *key)
return 0;
}
+static int dev_map_hash_delete_elem(struct bpf_map *map, void *key)
+{
+ struct bpf_dtab *dtab = container_of(map, struct bpf_dtab, map);
+ struct bpf_dtab_netdev *old_dev;
+ int k = *(u32 *)key;
+ unsigned long flags;
+ int ret = -ENOENT;
+
+ spin_lock_irqsave(&dtab->index_lock, flags);
+
+ old_dev = __dev_map_hash_lookup_elem(map, k);
+ if (old_dev) {
+ dtab->items--;
+ hlist_del_init_rcu(&old_dev->index_hlist);
+ call_rcu(&old_dev->rcu, __dev_map_entry_free);
+ ret = 0;
+ }
+ spin_unlock_irqrestore(&dtab->index_lock, flags);
+
+ return ret;
+}
+
static struct bpf_dtab_netdev *__dev_map_alloc_node(struct net *net,
struct bpf_dtab *dtab,
u32 ifindex,
@@ -502,6 +642,56 @@ static int dev_map_update_elem(struct bpf_map *map, void *key, void *value,
map, key, value, map_flags);
}
+static int __dev_map_hash_update_elem(struct net *net, struct bpf_map *map,
+ void *key, void *value, u64 map_flags)
+{
+ struct bpf_dtab *dtab = container_of(map, struct bpf_dtab, map);
+ struct bpf_dtab_netdev *dev, *old_dev;
+ u32 ifindex = *(u32 *)value;
+ u32 idx = *(u32 *)key;
+ unsigned long flags;
+
+ if (unlikely(map_flags > BPF_EXIST || !ifindex))
+ return -EINVAL;
+
+ old_dev = __dev_map_hash_lookup_elem(map, idx);
+ if (old_dev && (map_flags & BPF_NOEXIST))
+ return -EEXIST;
+
+ dev = __dev_map_alloc_node(net, dtab, ifindex, idx);
+ if (IS_ERR(dev))
+ return PTR_ERR(dev);
+
+ spin_lock_irqsave(&dtab->index_lock, flags);
+
+ if (old_dev) {
+ hlist_del_rcu(&old_dev->index_hlist);
+ } else {
+ if (dtab->items >= dtab->map.max_entries) {
+ spin_unlock_irqrestore(&dtab->index_lock, flags);
+ call_rcu(&dev->rcu, __dev_map_entry_free);
+ return -E2BIG;
+ }
+ dtab->items++;
+ }
+
+ hlist_add_head_rcu(&dev->index_hlist,
+ dev_map_index_hash(dtab, idx));
+ spin_unlock_irqrestore(&dtab->index_lock, flags);
+
+ if (old_dev)
+ call_rcu(&old_dev->rcu, __dev_map_entry_free);
+
+ return 0;
+}
+
+static int dev_map_hash_update_elem(struct bpf_map *map, void *key, void *value,
+ u64 map_flags)
+{
+ return __dev_map_hash_update_elem(current->nsproxy->net_ns,
+ map, key, value, map_flags);
+}
+
const struct bpf_map_ops dev_map_ops = {
.map_alloc = dev_map_alloc,
.map_free = dev_map_free,
@@ -512,6 +702,16 @@ const struct bpf_map_ops dev_map_ops = {
.map_check_btf = map_check_no_btf,
};
+const struct bpf_map_ops dev_map_hash_ops = {
+ .map_alloc = dev_map_alloc,
+ .map_free = dev_map_free,
+ .map_get_next_key = dev_map_hash_get_next_key,
+ .map_lookup_elem = dev_map_hash_lookup_elem,
+ .map_update_elem = dev_map_hash_update_elem,
+ .map_delete_elem = dev_map_hash_delete_elem,
+ .map_check_btf = map_check_no_btf,
+};
+
static int dev_map_notification(struct notifier_block *notifier,
ulong event, void *ptr)
{
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index 5900cbb966b1..cef851cd5c36 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -3457,6 +3457,7 @@ static int check_map_func_compatibility(struct bpf_verifier_env *env,
goto error;
break;
case BPF_MAP_TYPE_DEVMAP:
+ case BPF_MAP_TYPE_DEVMAP_HASH:
if (func_id != BPF_FUNC_redirect_map &&
func_id != BPF_FUNC_map_lookup_elem)
goto error;
@@ -3539,6 +3540,7 @@ static int check_map_func_compatibility(struct bpf_verifier_env *env,
break;
case BPF_FUNC_redirect_map:
if (map->map_type != BPF_MAP_TYPE_DEVMAP &&
+ map->map_type != BPF_MAP_TYPE_DEVMAP_HASH &&
map->map_type != BPF_MAP_TYPE_CPUMAP &&
map->map_type != BPF_MAP_TYPE_XSKMAP)
goto error;
diff --git a/net/core/filter.c b/net/core/filter.c
index 3961437ccc50..1eee70f80fba 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -3517,7 +3517,8 @@ static int __bpf_tx_xdp_map(struct net_device *dev_rx, void *fwd,
int err;
switch (map->map_type) {
- case BPF_MAP_TYPE_DEVMAP: {
+ case BPF_MAP_TYPE_DEVMAP:
+ case BPF_MAP_TYPE_DEVMAP_HASH: {
struct bpf_dtab_netdev *dst = fwd;
err = dev_map_enqueue(dst, xdp, dev_rx);
@@ -3554,6 +3555,7 @@ void xdp_do_flush_map(void)
if (map) {
switch (map->map_type) {
case BPF_MAP_TYPE_DEVMAP:
+ case BPF_MAP_TYPE_DEVMAP_HASH:
__dev_map_flush(map);
break;
case BPF_MAP_TYPE_CPUMAP:
@@ -3574,6 +3576,8 @@ static inline void *__xdp_map_lookup_elem(struct bpf_map *map, u32 index)
switch (map->map_type) {
case BPF_MAP_TYPE_DEVMAP:
return __dev_map_lookup_elem(map, index);
+ case BPF_MAP_TYPE_DEVMAP_HASH:
+ return __dev_map_hash_lookup_elem(map, index);
case BPF_MAP_TYPE_CPUMAP:
return __cpu_map_lookup_elem(map, index);
case BPF_MAP_TYPE_XSKMAP:
@@ -3655,7 +3659,8 @@ static int xdp_do_generic_redirect_map(struct net_device *dev,
ri->tgt_value = NULL;
WRITE_ONCE(ri->map, NULL);
- if (map->map_type == BPF_MAP_TYPE_DEVMAP) {
+ if (map->map_type == BPF_MAP_TYPE_DEVMAP ||
+ map->map_type == BPF_MAP_TYPE_DEVMAP_HASH) {
struct bpf_dtab_netdev *dst = fwd;
err = dev_map_generic_redirect(dst, skb, xdp_prog);
Copyright © 1996 – 2023 Jason A. Donenfeld. All Rights Reverse Engineered.