Merge branch 'sk-local-storage'

Martin KaFai Lau says:

====================
v4:
- Move checks to map_alloc_check in patch 1 (Stanislav Fomichev)
- Refactor BTF encoding macros to test_btf.h at
  a new patch 4 (Stanislav Fomichev)
- Refactor getenv and add print PASS message at the
  end of the test in patch 6 (Yonghong Song)

v3:
- Replace spinlock_types.h with spinlock.h in patch 1
  (kbuild test robot <lkp@intel.com>)

v2:
- Add the "test_maps.h" file in patch 5

This series introduces the BPF sk local storage.  The
details is in the patch 1 commit message.
====================

Acked-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

5 files changed, 64 insertions, 1 deletions

diff --git a/include/linux/bpf.h b/include/linux/bpf.h
index cd6341eabd74..9a21848fdb07 100644
--- a/include/linux/bpf.h
+++ b/include/linux/bpf.h
@@ -184,6 +184,7 @@ enum bpf_arg_type {
 	ARG_PTR_TO_MAP_KEY,	/* pointer to stack used as map key */
 	ARG_PTR_TO_MAP_VALUE,	/* pointer to stack used as map value */
 	ARG_PTR_TO_UNINIT_MAP_VALUE,	/* pointer to valid memory used to store a map value */
+	ARG_PTR_TO_MAP_VALUE_OR_NULL,	/* pointer to stack used as map value or NULL */
 
 	/* the following constraints used to prototype bpf_memcmp() and other
 	 * functions that access data on eBPF program stack
@@ -204,6 +205,7 @@ enum bpf_arg_type {
 	ARG_PTR_TO_SOCK_COMMON,	/* pointer to sock_common */
 	ARG_PTR_TO_INT,		/* pointer to int */
 	ARG_PTR_TO_LONG,	/* pointer to long */
+	ARG_PTR_TO_SOCKET,	/* pointer to bpf_sock (fullsock) */
 };
 
 /* type of values returned from helper functions */
diff --git a/include/linux/bpf_types.h b/include/linux/bpf_types.h
index a10d37bce364..5a9975678d6f 100644
--- a/include/linux/bpf_types.h
+++ b/include/linux/bpf_types.h
@@ -61,6 +61,7 @@ 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_SK_STORAGE, sk_storage_map_ops)
 #if defined(CONFIG_BPF_STREAM_PARSER)
 BPF_MAP_TYPE(BPF_MAP_TYPE_SOCKMAP, sock_map_ops)
 BPF_MAP_TYPE(BPF_MAP_TYPE_SOCKHASH, sock_hash_ops)
diff --git a/include/net/bpf_sk_storage.h b/include/net/bpf_sk_storage.h
new file mode 100644
index 000000000000..b9dcb02e756b
--- /dev/null
+++ b/include/net/bpf_sk_storage.h
@@ -0,0 +1,13 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/* Copyright (c) 2019 Facebook */
+#ifndef _BPF_SK_STORAGE_H
+#define _BPF_SK_STORAGE_H
+
+struct sock;
+
+void bpf_sk_storage_free(struct sock *sk);
+
+extern const struct bpf_func_proto bpf_sk_storage_get_proto;
+extern const struct bpf_func_proto bpf_sk_storage_delete_proto;
+
+#endif /* _BPF_SK_STORAGE_H */
diff --git a/include/net/sock.h b/include/net/sock.h
index 784cd19d5ff7..4d208c0f9c14 100644
--- a/include/net/sock.h
+++ b/include/net/sock.h
@@ -236,6 +236,8 @@ struct sock_common {
 	/* public: */
 };
 
+struct bpf_sk_storage;
+
 /**
   *	struct sock - network layer representation of sockets
   *	@__sk_common: shared layout with inet_timewait_sock
@@ -510,6 +512,9 @@ struct sock {
 #endif
 	void                    (*sk_destruct)(struct sock *sk);
 	struct sock_reuseport __rcu	*sk_reuseport_cb;
+#ifdef CONFIG_BPF_SYSCALL
+	struct bpf_sk_storage __rcu	*sk_bpf_storage;
+#endif
 	struct rcu_head		sk_rcu;
 };
 
diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h
index f7fa7a34a62d..72336bac7573 100644
--- a/include/uapi/linux/bpf.h
+++ b/include/uapi/linux/bpf.h
@@ -133,6 +133,7 @@ enum bpf_map_type {
 	BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE,
 	BPF_MAP_TYPE_QUEUE,
 	BPF_MAP_TYPE_STACK,
+	BPF_MAP_TYPE_SK_STORAGE,
 };
 
 /* Note that tracing related programs such as
@@ -2630,6 +2631,42 @@ union bpf_attr {
  *		was provided.
  *
  *		**-ERANGE** if resulting value was out of range.
+ *
+ * void *bpf_sk_storage_get(struct bpf_map *map, struct bpf_sock *sk, void *value, u64 flags)
+ *	Description
+ *		Get a bpf-local-storage from a sk.
+ *
+ *		Logically, it could be thought of getting the value from
+ *		a *map* with *sk* as the **key**.  From this
+ *		perspective,  the usage is not much different from
+ *		**bpf_map_lookup_elem(map, &sk)** except this
+ *		helper enforces the key must be a **bpf_fullsock()**
+ *		and the map must be a BPF_MAP_TYPE_SK_STORAGE also.
+ *
+ *		Underneath, the value is stored locally at *sk* instead of
+ *		the map.  The *map* is used as the bpf-local-storage **type**.
+ *		The bpf-local-storage **type** (i.e. the *map*) is searched
+ *		against all bpf-local-storages residing at sk.
+ *
+ *		An optional *flags* (BPF_SK_STORAGE_GET_F_CREATE) can be
+ *		used such that a new bpf-local-storage will be
+ *		created if one does not exist.  *value* can be used
+ *		together with BPF_SK_STORAGE_GET_F_CREATE to specify
+ *		the initial value of a bpf-local-storage.  If *value* is
+ *		NULL, the new bpf-local-storage will be zero initialized.
+ *	Return
+ *		A bpf-local-storage pointer is returned on success.
+ *
+ *		**NULL** if not found or there was an error in adding
+ *		a new bpf-local-storage.
+ *
+ * int bpf_sk_storage_delete(struct bpf_map *map, struct bpf_sock *sk)
+ *	Description
+ *		Delete a bpf-local-storage from a sk.
+ *	Return
+ *		0 on success.
+ *
+ *		**-ENOENT** if the bpf-local-storage cannot be found.
  */
 #define __BPF_FUNC_MAPPER(FN)		\
 	FN(unspec),			\
@@ -2738,7 +2775,9 @@ union bpf_attr {
 	FN(sysctl_get_new_value),	\
 	FN(sysctl_set_new_value),	\
 	FN(strtol),			\
-	FN(strtoul),
+	FN(strtoul),			\
+	FN(sk_storage_get),		\
+	FN(sk_storage_delete),
 
 /* integer value in 'imm' field of BPF_CALL instruction selects which helper
  * function eBPF program intends to call
@@ -2814,6 +2853,9 @@ enum bpf_func_id {
 /* BPF_FUNC_sysctl_get_name flags. */
 #define BPF_F_SYSCTL_BASE_NAME		(1ULL << 0)
 
+/* BPF_FUNC_sk_storage_get flags */
+#define BPF_SK_STORAGE_GET_F_CREATE	(1ULL << 0)
+
 /* Mode for BPF_FUNC_skb_adjust_room helper. */
 enum bpf_adj_room_mode {
 	BPF_ADJ_ROOM_NET,