From cf62089b0edd7e74a1f474844b4d9f7b5697fb5c Mon Sep 17 00:00:00 2001
From: Willem de Bruijn <willemb@google.com>
Date: Tue, 3 Mar 2020 15:05:01 -0500
Subject: bpf: Add gso_size to __sk_buff

BPF programs may want to know whether an skb is gso. The canonical
answer is skb_is_gso(skb), which tests that gso_size != 0.

Expose this field in the same manner as gso_segs. That field itself
is not a sufficient signal, as the comment in skb_shared_info makes
clear: gso_segs may be zero, e.g., from dodgy sources.

Also prepare net/bpf/test_run for upcoming BPF_PROG_TEST_RUN tests
of the feature.

Signed-off-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200303200503.226217-2-willemdebruijn.kernel@gmail.com
---
 include/uapi/linux/bpf.h | 1 +
 1 file changed, 1 insertion(+)

(limited to 'include/uapi')

diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h
index 8e98ced0963b..180337fae97e 100644
--- a/include/uapi/linux/bpf.h
+++ b/include/uapi/linux/bpf.h
@@ -3176,6 +3176,7 @@ struct __sk_buff {
 	__u32 wire_len;
 	__u32 gso_segs;
 	__bpf_md_ptr(struct bpf_sock *, sk);
+	__u32 gso_size;
 };
 
 struct bpf_tunnel_key {
-- 
cgit v1.2.3


From 1aae4bdd787998ea331a56f3db9d8595790fe2f9 Mon Sep 17 00:00:00 2001
From: Andrii Nakryiko <andriin@fb.com>
Date: Mon, 2 Mar 2020 16:32:31 -0800
Subject: bpf: Switch BPF UAPI #define constants used from BPF program side to
 enums

Switch BPF UAPI constants, previously defined as #define macro, to anonymous
enum values. This preserves constants values and behavior in expressions, but
has added advantaged of being captured as part of DWARF and, subsequently, BTF
type info. Which, in turn, greatly improves usefulness of generated vmlinux.h
for BPF applications, as it will not require BPF users to copy/paste various
flags and constants, which are frequently used with BPF helpers. Only those
constants that are used/useful from BPF program side are converted.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20200303003233.3496043-2-andriin@fb.com
---
 include/uapi/linux/bpf.h       | 175 +++++++++++++++++++++++++---------------
 tools/include/uapi/linux/bpf.h | 177 +++++++++++++++++++++++++----------------
 2 files changed, 219 insertions(+), 133 deletions(-)

(limited to 'include/uapi')

diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h
index 180337fae97e..d6b33ea27bcc 100644
--- a/include/uapi/linux/bpf.h
+++ b/include/uapi/linux/bpf.h
@@ -325,44 +325,46 @@ enum bpf_attach_type {
 #define BPF_PSEUDO_CALL		1
 
 /* flags for BPF_MAP_UPDATE_ELEM command */
-#define BPF_ANY		0 /* create new element or update existing */
-#define BPF_NOEXIST	1 /* create new element if it didn't exist */
-#define BPF_EXIST	2 /* update existing element */
-#define BPF_F_LOCK	4 /* spin_lock-ed map_lookup/map_update */
+enum {
+	BPF_ANY		= 0, /* create new element or update existing */
+	BPF_NOEXIST	= 1, /* create new element if it didn't exist */
+	BPF_EXIST	= 2, /* update existing element */
+	BPF_F_LOCK	= 4, /* spin_lock-ed map_lookup/map_update */
+};
 
 /* flags for BPF_MAP_CREATE command */
-#define BPF_F_NO_PREALLOC	(1U << 0)
+enum {
+	BPF_F_NO_PREALLOC	= (1U << 0),
 /* Instead of having one common LRU list in the
  * BPF_MAP_TYPE_LRU_[PERCPU_]HASH map, use a percpu LRU list
  * which can scale and perform better.
  * Note, the LRU nodes (including free nodes) cannot be moved
  * across different LRU lists.
  */
-#define BPF_F_NO_COMMON_LRU	(1U << 1)
+	BPF_F_NO_COMMON_LRU	= (1U << 1),
 /* Specify numa node during map creation */
-#define BPF_F_NUMA_NODE		(1U << 2)
-
-#define BPF_OBJ_NAME_LEN 16U
+	BPF_F_NUMA_NODE		= (1U << 2),
 
 /* Flags for accessing BPF object from syscall side. */
-#define BPF_F_RDONLY		(1U << 3)
-#define BPF_F_WRONLY		(1U << 4)
+	BPF_F_RDONLY		= (1U << 3),
+	BPF_F_WRONLY		= (1U << 4),
 
 /* Flag for stack_map, store build_id+offset instead of pointer */
-#define BPF_F_STACK_BUILD_ID	(1U << 5)
+	BPF_F_STACK_BUILD_ID	= (1U << 5),
 
 /* Zero-initialize hash function seed. This should only be used for testing. */
-#define BPF_F_ZERO_SEED		(1U << 6)
+	BPF_F_ZERO_SEED		= (1U << 6),
 
 /* Flags for accessing BPF object from program side. */
-#define BPF_F_RDONLY_PROG	(1U << 7)
-#define BPF_F_WRONLY_PROG	(1U << 8)
+	BPF_F_RDONLY_PROG	= (1U << 7),
+	BPF_F_WRONLY_PROG	= (1U << 8),
 
 /* Clone map from listener for newly accepted socket */
-#define BPF_F_CLONE		(1U << 9)
+	BPF_F_CLONE		= (1U << 9),
 
 /* Enable memory-mapping BPF map */
-#define BPF_F_MMAPABLE		(1U << 10)
+	BPF_F_MMAPABLE		= (1U << 10),
+};
 
 /* Flags for BPF_PROG_QUERY. */
 
@@ -391,6 +393,8 @@ struct bpf_stack_build_id {
 	};
 };
 
+#define BPF_OBJ_NAME_LEN 16U
+
 union bpf_attr {
 	struct { /* anonymous struct used by BPF_MAP_CREATE command */
 		__u32	map_type;	/* one of enum bpf_map_type */
@@ -3045,72 +3049,100 @@ enum bpf_func_id {
 /* All flags used by eBPF helper functions, placed here. */
 
 /* BPF_FUNC_skb_store_bytes flags. */
-#define BPF_F_RECOMPUTE_CSUM		(1ULL << 0)
-#define BPF_F_INVALIDATE_HASH		(1ULL << 1)
+enum {
+	BPF_F_RECOMPUTE_CSUM		= (1ULL << 0),
+	BPF_F_INVALIDATE_HASH		= (1ULL << 1),
+};
 
 /* BPF_FUNC_l3_csum_replace and BPF_FUNC_l4_csum_replace flags.
  * First 4 bits are for passing the header field size.
  */
-#define BPF_F_HDR_FIELD_MASK		0xfULL
+enum {
+	BPF_F_HDR_FIELD_MASK		= 0xfULL,
+};
 
 /* BPF_FUNC_l4_csum_replace flags. */
-#define BPF_F_PSEUDO_HDR		(1ULL << 4)
-#define BPF_F_MARK_MANGLED_0		(1ULL << 5)
-#define BPF_F_MARK_ENFORCE		(1ULL << 6)
+enum {
+	BPF_F_PSEUDO_HDR		= (1ULL << 4),
+	BPF_F_MARK_MANGLED_0		= (1ULL << 5),
+	BPF_F_MARK_ENFORCE		= (1ULL << 6),
+};
 
 /* BPF_FUNC_clone_redirect and BPF_FUNC_redirect flags. */
-#define BPF_F_INGRESS			(1ULL << 0)
+enum {
+	BPF_F_INGRESS			= (1ULL << 0),
+};
 
 /* BPF_FUNC_skb_set_tunnel_key and BPF_FUNC_skb_get_tunnel_key flags. */
-#define BPF_F_TUNINFO_IPV6		(1ULL << 0)
+enum {
+	BPF_F_TUNINFO_IPV6		= (1ULL << 0),
+};
 
 /* flags for both BPF_FUNC_get_stackid and BPF_FUNC_get_stack. */
-#define BPF_F_SKIP_FIELD_MASK		0xffULL
-#define BPF_F_USER_STACK		(1ULL << 8)
+enum {
+	BPF_F_SKIP_FIELD_MASK		= 0xffULL,
+	BPF_F_USER_STACK		= (1ULL << 8),
 /* flags used by BPF_FUNC_get_stackid only. */
-#define BPF_F_FAST_STACK_CMP		(1ULL << 9)
-#define BPF_F_REUSE_STACKID		(1ULL << 10)
+	BPF_F_FAST_STACK_CMP		= (1ULL << 9),
+	BPF_F_REUSE_STACKID		= (1ULL << 10),
 /* flags used by BPF_FUNC_get_stack only. */
-#define BPF_F_USER_BUILD_ID		(1ULL << 11)
+	BPF_F_USER_BUILD_ID		= (1ULL << 11),
+};
 
 /* BPF_FUNC_skb_set_tunnel_key flags. */
-#define BPF_F_ZERO_CSUM_TX		(1ULL << 1)
-#define BPF_F_DONT_FRAGMENT		(1ULL << 2)
-#define BPF_F_SEQ_NUMBER		(1ULL << 3)
+enum {
+	BPF_F_ZERO_CSUM_TX		= (1ULL << 1),
+	BPF_F_DONT_FRAGMENT		= (1ULL << 2),
+	BPF_F_SEQ_NUMBER		= (1ULL << 3),
+};
 
 /* BPF_FUNC_perf_event_output, BPF_FUNC_perf_event_read and
  * BPF_FUNC_perf_event_read_value flags.
  */
-#define BPF_F_INDEX_MASK		0xffffffffULL
-#define BPF_F_CURRENT_CPU		BPF_F_INDEX_MASK
+enum {
+	BPF_F_INDEX_MASK		= 0xffffffffULL,
+	BPF_F_CURRENT_CPU		= BPF_F_INDEX_MASK,
 /* BPF_FUNC_perf_event_output for sk_buff input context. */
-#define BPF_F_CTXLEN_MASK		(0xfffffULL << 32)
+	BPF_F_CTXLEN_MASK		= (0xfffffULL << 32),
+};
 
 /* Current network namespace */
-#define BPF_F_CURRENT_NETNS		(-1L)
+enum {
+	BPF_F_CURRENT_NETNS		= (-1L),
+};
 
 /* BPF_FUNC_skb_adjust_room flags. */
-#define BPF_F_ADJ_ROOM_FIXED_GSO	(1ULL << 0)
+enum {
+	BPF_F_ADJ_ROOM_FIXED_GSO	= (1ULL << 0),
+	BPF_F_ADJ_ROOM_ENCAP_L3_IPV4	= (1ULL << 1),
+	BPF_F_ADJ_ROOM_ENCAP_L3_IPV6	= (1ULL << 2),
+	BPF_F_ADJ_ROOM_ENCAP_L4_GRE	= (1ULL << 3),
+	BPF_F_ADJ_ROOM_ENCAP_L4_UDP	= (1ULL << 4),
+};
 
-#define BPF_ADJ_ROOM_ENCAP_L2_MASK	0xff
-#define BPF_ADJ_ROOM_ENCAP_L2_SHIFT	56
+enum {
+	BPF_ADJ_ROOM_ENCAP_L2_MASK	= 0xff,
+	BPF_ADJ_ROOM_ENCAP_L2_SHIFT	= 56,
+};
 
-#define BPF_F_ADJ_ROOM_ENCAP_L3_IPV4	(1ULL << 1)
-#define BPF_F_ADJ_ROOM_ENCAP_L3_IPV6	(1ULL << 2)
-#define BPF_F_ADJ_ROOM_ENCAP_L4_GRE	(1ULL << 3)
-#define BPF_F_ADJ_ROOM_ENCAP_L4_UDP	(1ULL << 4)
 #define BPF_F_ADJ_ROOM_ENCAP_L2(len)	(((__u64)len & \
 					  BPF_ADJ_ROOM_ENCAP_L2_MASK) \
 					 << BPF_ADJ_ROOM_ENCAP_L2_SHIFT)
 
 /* BPF_FUNC_sysctl_get_name flags. */
-#define BPF_F_SYSCTL_BASE_NAME		(1ULL << 0)
+enum {
+	BPF_F_SYSCTL_BASE_NAME		= (1ULL << 0),
+};
 
 /* BPF_FUNC_sk_storage_get flags */
-#define BPF_SK_STORAGE_GET_F_CREATE	(1ULL << 0)
+enum {
+	BPF_SK_STORAGE_GET_F_CREATE	= (1ULL << 0),
+};
 
 /* BPF_FUNC_read_branch_records flags. */
-#define BPF_F_GET_BRANCH_RECORDS_SIZE	(1ULL << 0)
+enum {
+	BPF_F_GET_BRANCH_RECORDS_SIZE	= (1ULL << 0),
+};
 
 /* Mode for BPF_FUNC_skb_adjust_room helper. */
 enum bpf_adj_room_mode {
@@ -3529,13 +3561,14 @@ struct bpf_sock_ops {
 };
 
 /* Definitions for bpf_sock_ops_cb_flags */
-#define BPF_SOCK_OPS_RTO_CB_FLAG	(1<<0)
-#define BPF_SOCK_OPS_RETRANS_CB_FLAG	(1<<1)
-#define BPF_SOCK_OPS_STATE_CB_FLAG	(1<<2)
-#define BPF_SOCK_OPS_RTT_CB_FLAG	(1<<3)
-#define BPF_SOCK_OPS_ALL_CB_FLAGS       0xF		/* Mask of all currently
-							 * supported cb flags
-							 */
+enum {
+	BPF_SOCK_OPS_RTO_CB_FLAG	= (1<<0),
+	BPF_SOCK_OPS_RETRANS_CB_FLAG	= (1<<1),
+	BPF_SOCK_OPS_STATE_CB_FLAG	= (1<<2),
+	BPF_SOCK_OPS_RTT_CB_FLAG	= (1<<3),
+/* Mask of all currently supported cb flags */
+	BPF_SOCK_OPS_ALL_CB_FLAGS       = 0xF,
+};
 
 /* List of known BPF sock_ops operators.
  * New entries can only be added at the end
@@ -3614,8 +3647,10 @@ enum {
 	BPF_TCP_MAX_STATES	/* Leave at the end! */
 };
 
-#define TCP_BPF_IW		1001	/* Set TCP initial congestion window */
-#define TCP_BPF_SNDCWND_CLAMP	1002	/* Set sndcwnd_clamp */
+enum {
+	TCP_BPF_IW		= 1001,	/* Set TCP initial congestion window */
+	TCP_BPF_SNDCWND_CLAMP	= 1002,	/* Set sndcwnd_clamp */
+};
 
 struct bpf_perf_event_value {
 	__u64 counter;
@@ -3623,12 +3658,16 @@ struct bpf_perf_event_value {
 	__u64 running;
 };
 
-#define BPF_DEVCG_ACC_MKNOD	(1ULL << 0)
-#define BPF_DEVCG_ACC_READ	(1ULL << 1)
-#define BPF_DEVCG_ACC_WRITE	(1ULL << 2)
+enum {
+	BPF_DEVCG_ACC_MKNOD	= (1ULL << 0),
+	BPF_DEVCG_ACC_READ	= (1ULL << 1),
+	BPF_DEVCG_ACC_WRITE	= (1ULL << 2),
+};
 
-#define BPF_DEVCG_DEV_BLOCK	(1ULL << 0)
-#define BPF_DEVCG_DEV_CHAR	(1ULL << 1)
+enum {
+	BPF_DEVCG_DEV_BLOCK	= (1ULL << 0),
+	BPF_DEVCG_DEV_CHAR	= (1ULL << 1),
+};
 
 struct bpf_cgroup_dev_ctx {
 	/* access_type encoded as (BPF_DEVCG_ACC_* << 16) | BPF_DEVCG_DEV_* */
@@ -3644,8 +3683,10 @@ struct bpf_raw_tracepoint_args {
 /* DIRECT:  Skip the FIB rules and go to FIB table associated with device
  * OUTPUT:  Do lookup from egress perspective; default is ingress
  */
-#define BPF_FIB_LOOKUP_DIRECT  (1U << 0)
-#define BPF_FIB_LOOKUP_OUTPUT  (1U << 1)
+enum {
+	BPF_FIB_LOOKUP_DIRECT  = (1U << 0),
+	BPF_FIB_LOOKUP_OUTPUT  = (1U << 1),
+};
 
 enum {
 	BPF_FIB_LKUP_RET_SUCCESS,      /* lookup successful */
@@ -3717,9 +3758,11 @@ enum bpf_task_fd_type {
 	BPF_FD_TYPE_URETPROBE,		/* filename + offset */
 };
 
-#define BPF_FLOW_DISSECTOR_F_PARSE_1ST_FRAG		(1U << 0)
-#define BPF_FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL		(1U << 1)
-#define BPF_FLOW_DISSECTOR_F_STOP_AT_ENCAP		(1U << 2)
+enum {
+	BPF_FLOW_DISSECTOR_F_PARSE_1ST_FRAG		= (1U << 0),
+	BPF_FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL		= (1U << 1),
+	BPF_FLOW_DISSECTOR_F_STOP_AT_ENCAP		= (1U << 2),
+};
 
 struct bpf_flow_keys {
 	__u16	nhoff;
diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h
index 7c689f4552dd..d6b33ea27bcc 100644
--- a/tools/include/uapi/linux/bpf.h
+++ b/tools/include/uapi/linux/bpf.h
@@ -73,7 +73,7 @@ struct bpf_insn {
 /* Key of an a BPF_MAP_TYPE_LPM_TRIE entry */
 struct bpf_lpm_trie_key {
 	__u32	prefixlen;	/* up to 32 for AF_INET, 128 for AF_INET6 */
-	__u8	data[0];	/* Arbitrary size */
+	__u8	data[];	/* Arbitrary size */
 };
 
 struct bpf_cgroup_storage_key {
@@ -325,44 +325,46 @@ enum bpf_attach_type {
 #define BPF_PSEUDO_CALL		1
 
 /* flags for BPF_MAP_UPDATE_ELEM command */
-#define BPF_ANY		0 /* create new element or update existing */
-#define BPF_NOEXIST	1 /* create new element if it didn't exist */
-#define BPF_EXIST	2 /* update existing element */
-#define BPF_F_LOCK	4 /* spin_lock-ed map_lookup/map_update */
+enum {
+	BPF_ANY		= 0, /* create new element or update existing */
+	BPF_NOEXIST	= 1, /* create new element if it didn't exist */
+	BPF_EXIST	= 2, /* update existing element */
+	BPF_F_LOCK	= 4, /* spin_lock-ed map_lookup/map_update */
+};
 
 /* flags for BPF_MAP_CREATE command */
-#define BPF_F_NO_PREALLOC	(1U << 0)
+enum {
+	BPF_F_NO_PREALLOC	= (1U << 0),
 /* Instead of having one common LRU list in the
  * BPF_MAP_TYPE_LRU_[PERCPU_]HASH map, use a percpu LRU list
  * which can scale and perform better.
  * Note, the LRU nodes (including free nodes) cannot be moved
  * across different LRU lists.
  */
-#define BPF_F_NO_COMMON_LRU	(1U << 1)
+	BPF_F_NO_COMMON_LRU	= (1U << 1),
 /* Specify numa node during map creation */
-#define BPF_F_NUMA_NODE		(1U << 2)
-
-#define BPF_OBJ_NAME_LEN 16U
+	BPF_F_NUMA_NODE		= (1U << 2),
 
 /* Flags for accessing BPF object from syscall side. */
-#define BPF_F_RDONLY		(1U << 3)
-#define BPF_F_WRONLY		(1U << 4)
+	BPF_F_RDONLY		= (1U << 3),
+	BPF_F_WRONLY		= (1U << 4),
 
 /* Flag for stack_map, store build_id+offset instead of pointer */
-#define BPF_F_STACK_BUILD_ID	(1U << 5)
+	BPF_F_STACK_BUILD_ID	= (1U << 5),
 
 /* Zero-initialize hash function seed. This should only be used for testing. */
-#define BPF_F_ZERO_SEED		(1U << 6)
+	BPF_F_ZERO_SEED		= (1U << 6),
 
 /* Flags for accessing BPF object from program side. */
-#define BPF_F_RDONLY_PROG	(1U << 7)
-#define BPF_F_WRONLY_PROG	(1U << 8)
+	BPF_F_RDONLY_PROG	= (1U << 7),
+	BPF_F_WRONLY_PROG	= (1U << 8),
 
 /* Clone map from listener for newly accepted socket */
-#define BPF_F_CLONE		(1U << 9)
+	BPF_F_CLONE		= (1U << 9),
 
 /* Enable memory-mapping BPF map */
-#define BPF_F_MMAPABLE		(1U << 10)
+	BPF_F_MMAPABLE		= (1U << 10),
+};
 
 /* Flags for BPF_PROG_QUERY. */
 
@@ -391,6 +393,8 @@ struct bpf_stack_build_id {
 	};
 };
 
+#define BPF_OBJ_NAME_LEN 16U
+
 union bpf_attr {
 	struct { /* anonymous struct used by BPF_MAP_CREATE command */
 		__u32	map_type;	/* one of enum bpf_map_type */
@@ -3045,72 +3049,100 @@ enum bpf_func_id {
 /* All flags used by eBPF helper functions, placed here. */
 
 /* BPF_FUNC_skb_store_bytes flags. */
-#define BPF_F_RECOMPUTE_CSUM		(1ULL << 0)
-#define BPF_F_INVALIDATE_HASH		(1ULL << 1)
+enum {
+	BPF_F_RECOMPUTE_CSUM		= (1ULL << 0),
+	BPF_F_INVALIDATE_HASH		= (1ULL << 1),
+};
 
 /* BPF_FUNC_l3_csum_replace and BPF_FUNC_l4_csum_replace flags.
  * First 4 bits are for passing the header field size.
  */
-#define BPF_F_HDR_FIELD_MASK		0xfULL
+enum {
+	BPF_F_HDR_FIELD_MASK		= 0xfULL,
+};
 
 /* BPF_FUNC_l4_csum_replace flags. */
-#define BPF_F_PSEUDO_HDR		(1ULL << 4)
-#define BPF_F_MARK_MANGLED_0		(1ULL << 5)
-#define BPF_F_MARK_ENFORCE		(1ULL << 6)
+enum {
+	BPF_F_PSEUDO_HDR		= (1ULL << 4),
+	BPF_F_MARK_MANGLED_0		= (1ULL << 5),
+	BPF_F_MARK_ENFORCE		= (1ULL << 6),
+};
 
 /* BPF_FUNC_clone_redirect and BPF_FUNC_redirect flags. */
-#define BPF_F_INGRESS			(1ULL << 0)
+enum {
+	BPF_F_INGRESS			= (1ULL << 0),
+};
 
 /* BPF_FUNC_skb_set_tunnel_key and BPF_FUNC_skb_get_tunnel_key flags. */
-#define BPF_F_TUNINFO_IPV6		(1ULL << 0)
+enum {
+	BPF_F_TUNINFO_IPV6		= (1ULL << 0),
+};
 
 /* flags for both BPF_FUNC_get_stackid and BPF_FUNC_get_stack. */
-#define BPF_F_SKIP_FIELD_MASK		0xffULL
-#define BPF_F_USER_STACK		(1ULL << 8)
+enum {
+	BPF_F_SKIP_FIELD_MASK		= 0xffULL,
+	BPF_F_USER_STACK		= (1ULL << 8),
 /* flags used by BPF_FUNC_get_stackid only. */
-#define BPF_F_FAST_STACK_CMP		(1ULL << 9)
-#define BPF_F_REUSE_STACKID		(1ULL << 10)
+	BPF_F_FAST_STACK_CMP		= (1ULL << 9),
+	BPF_F_REUSE_STACKID		= (1ULL << 10),
 /* flags used by BPF_FUNC_get_stack only. */
-#define BPF_F_USER_BUILD_ID		(1ULL << 11)
+	BPF_F_USER_BUILD_ID		= (1ULL << 11),
+};
 
 /* BPF_FUNC_skb_set_tunnel_key flags. */
-#define BPF_F_ZERO_CSUM_TX		(1ULL << 1)
-#define BPF_F_DONT_FRAGMENT		(1ULL << 2)
-#define BPF_F_SEQ_NUMBER		(1ULL << 3)
+enum {
+	BPF_F_ZERO_CSUM_TX		= (1ULL << 1),
+	BPF_F_DONT_FRAGMENT		= (1ULL << 2),
+	BPF_F_SEQ_NUMBER		= (1ULL << 3),
+};
 
 /* BPF_FUNC_perf_event_output, BPF_FUNC_perf_event_read and
  * BPF_FUNC_perf_event_read_value flags.
  */
-#define BPF_F_INDEX_MASK		0xffffffffULL
-#define BPF_F_CURRENT_CPU		BPF_F_INDEX_MASK
+enum {
+	BPF_F_INDEX_MASK		= 0xffffffffULL,
+	BPF_F_CURRENT_CPU		= BPF_F_INDEX_MASK,
 /* BPF_FUNC_perf_event_output for sk_buff input context. */
-#define BPF_F_CTXLEN_MASK		(0xfffffULL << 32)
+	BPF_F_CTXLEN_MASK		= (0xfffffULL << 32),
+};
 
 /* Current network namespace */
-#define BPF_F_CURRENT_NETNS		(-1L)
+enum {
+	BPF_F_CURRENT_NETNS		= (-1L),
+};
 
 /* BPF_FUNC_skb_adjust_room flags. */
-#define BPF_F_ADJ_ROOM_FIXED_GSO	(1ULL << 0)
+enum {
+	BPF_F_ADJ_ROOM_FIXED_GSO	= (1ULL << 0),
+	BPF_F_ADJ_ROOM_ENCAP_L3_IPV4	= (1ULL << 1),
+	BPF_F_ADJ_ROOM_ENCAP_L3_IPV6	= (1ULL << 2),
+	BPF_F_ADJ_ROOM_ENCAP_L4_GRE	= (1ULL << 3),
+	BPF_F_ADJ_ROOM_ENCAP_L4_UDP	= (1ULL << 4),
+};
 
-#define BPF_ADJ_ROOM_ENCAP_L2_MASK	0xff
-#define BPF_ADJ_ROOM_ENCAP_L2_SHIFT	56
+enum {
+	BPF_ADJ_ROOM_ENCAP_L2_MASK	= 0xff,
+	BPF_ADJ_ROOM_ENCAP_L2_SHIFT	= 56,
+};
 
-#define BPF_F_ADJ_ROOM_ENCAP_L3_IPV4	(1ULL << 1)
-#define BPF_F_ADJ_ROOM_ENCAP_L3_IPV6	(1ULL << 2)
-#define BPF_F_ADJ_ROOM_ENCAP_L4_GRE	(1ULL << 3)
-#define BPF_F_ADJ_ROOM_ENCAP_L4_UDP	(1ULL << 4)
 #define BPF_F_ADJ_ROOM_ENCAP_L2(len)	(((__u64)len & \
 					  BPF_ADJ_ROOM_ENCAP_L2_MASK) \
 					 << BPF_ADJ_ROOM_ENCAP_L2_SHIFT)
 
 /* BPF_FUNC_sysctl_get_name flags. */
-#define BPF_F_SYSCTL_BASE_NAME		(1ULL << 0)
+enum {
+	BPF_F_SYSCTL_BASE_NAME		= (1ULL << 0),
+};
 
 /* BPF_FUNC_sk_storage_get flags */
-#define BPF_SK_STORAGE_GET_F_CREATE	(1ULL << 0)
+enum {
+	BPF_SK_STORAGE_GET_F_CREATE	= (1ULL << 0),
+};
 
 /* BPF_FUNC_read_branch_records flags. */
-#define BPF_F_GET_BRANCH_RECORDS_SIZE	(1ULL << 0)
+enum {
+	BPF_F_GET_BRANCH_RECORDS_SIZE	= (1ULL << 0),
+};
 
 /* Mode for BPF_FUNC_skb_adjust_room helper. */
 enum bpf_adj_room_mode {
@@ -3529,13 +3561,14 @@ struct bpf_sock_ops {
 };
 
 /* Definitions for bpf_sock_ops_cb_flags */
-#define BPF_SOCK_OPS_RTO_CB_FLAG	(1<<0)
-#define BPF_SOCK_OPS_RETRANS_CB_FLAG	(1<<1)
-#define BPF_SOCK_OPS_STATE_CB_FLAG	(1<<2)
-#define BPF_SOCK_OPS_RTT_CB_FLAG	(1<<3)
-#define BPF_SOCK_OPS_ALL_CB_FLAGS       0xF		/* Mask of all currently
-							 * supported cb flags
-							 */
+enum {
+	BPF_SOCK_OPS_RTO_CB_FLAG	= (1<<0),
+	BPF_SOCK_OPS_RETRANS_CB_FLAG	= (1<<1),
+	BPF_SOCK_OPS_STATE_CB_FLAG	= (1<<2),
+	BPF_SOCK_OPS_RTT_CB_FLAG	= (1<<3),
+/* Mask of all currently supported cb flags */
+	BPF_SOCK_OPS_ALL_CB_FLAGS       = 0xF,
+};
 
 /* List of known BPF sock_ops operators.
  * New entries can only be added at the end
@@ -3614,8 +3647,10 @@ enum {
 	BPF_TCP_MAX_STATES	/* Leave at the end! */
 };
 
-#define TCP_BPF_IW		1001	/* Set TCP initial congestion window */
-#define TCP_BPF_SNDCWND_CLAMP	1002	/* Set sndcwnd_clamp */
+enum {
+	TCP_BPF_IW		= 1001,	/* Set TCP initial congestion window */
+	TCP_BPF_SNDCWND_CLAMP	= 1002,	/* Set sndcwnd_clamp */
+};
 
 struct bpf_perf_event_value {
 	__u64 counter;
@@ -3623,12 +3658,16 @@ struct bpf_perf_event_value {
 	__u64 running;
 };
 
-#define BPF_DEVCG_ACC_MKNOD	(1ULL << 0)
-#define BPF_DEVCG_ACC_READ	(1ULL << 1)
-#define BPF_DEVCG_ACC_WRITE	(1ULL << 2)
+enum {
+	BPF_DEVCG_ACC_MKNOD	= (1ULL << 0),
+	BPF_DEVCG_ACC_READ	= (1ULL << 1),
+	BPF_DEVCG_ACC_WRITE	= (1ULL << 2),
+};
 
-#define BPF_DEVCG_DEV_BLOCK	(1ULL << 0)
-#define BPF_DEVCG_DEV_CHAR	(1ULL << 1)
+enum {
+	BPF_DEVCG_DEV_BLOCK	= (1ULL << 0),
+	BPF_DEVCG_DEV_CHAR	= (1ULL << 1),
+};
 
 struct bpf_cgroup_dev_ctx {
 	/* access_type encoded as (BPF_DEVCG_ACC_* << 16) | BPF_DEVCG_DEV_* */
@@ -3644,8 +3683,10 @@ struct bpf_raw_tracepoint_args {
 /* DIRECT:  Skip the FIB rules and go to FIB table associated with device
  * OUTPUT:  Do lookup from egress perspective; default is ingress
  */
-#define BPF_FIB_LOOKUP_DIRECT  (1U << 0)
-#define BPF_FIB_LOOKUP_OUTPUT  (1U << 1)
+enum {
+	BPF_FIB_LOOKUP_DIRECT  = (1U << 0),
+	BPF_FIB_LOOKUP_OUTPUT  = (1U << 1),
+};
 
 enum {
 	BPF_FIB_LKUP_RET_SUCCESS,      /* lookup successful */
@@ -3717,9 +3758,11 @@ enum bpf_task_fd_type {
 	BPF_FD_TYPE_URETPROBE,		/* filename + offset */
 };
 
-#define BPF_FLOW_DISSECTOR_F_PARSE_1ST_FRAG		(1U << 0)
-#define BPF_FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL		(1U << 1)
-#define BPF_FLOW_DISSECTOR_F_STOP_AT_ENCAP		(1U << 2)
+enum {
+	BPF_FLOW_DISSECTOR_F_PARSE_1ST_FRAG		= (1U << 0),
+	BPF_FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL		= (1U << 1),
+	BPF_FLOW_DISSECTOR_F_STOP_AT_ENCAP		= (1U << 2),
+};
 
 struct bpf_flow_keys {
 	__u16	nhoff;
-- 
cgit v1.2.3


From ae24082331d9bbaae283aafbe930a8f0eb85605a Mon Sep 17 00:00:00 2001
From: KP Singh <kpsingh@google.com>
Date: Wed, 4 Mar 2020 20:18:49 +0100
Subject: bpf: Introduce BPF_MODIFY_RETURN

When multiple programs are attached, each program receives the return
value from the previous program on the stack and the last program
provides the return value to the attached function.

The fmod_ret bpf programs are run after the fentry programs and before
the fexit programs. The original function is only called if all the
fmod_ret programs return 0 to avoid any unintended side-effects. The
success value, i.e. 0 is not currently configurable but can be made so
where user-space can specify it at load time.

For example:

int func_to_be_attached(int a, int b)
{  <--- do_fentry

do_fmod_ret:
   <update ret by calling fmod_ret>
   if (ret != 0)
        goto do_fexit;

original_function:

    <side_effects_happen_here>

}  <--- do_fexit

The fmod_ret program attached to this function can be defined as:

SEC("fmod_ret/func_to_be_attached")
int BPF_PROG(func_name, int a, int b, int ret)
{
        // This will skip the original function logic.
        return 1;
}

The first fmod_ret program is passed 0 in its return argument.

Signed-off-by: KP Singh <kpsingh@google.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20200304191853.1529-4-kpsingh@chromium.org
---
 arch/x86/net/bpf_jit_comp.c    | 130 +++++++++++++++++++++++++++++++++++++----
 include/linux/bpf.h            |   1 +
 include/uapi/linux/bpf.h       |   1 +
 kernel/bpf/btf.c               |   3 +-
 kernel/bpf/syscall.c           |   1 +
 kernel/bpf/trampoline.c        |   5 +-
 kernel/bpf/verifier.c          |   1 +
 tools/include/uapi/linux/bpf.h |   1 +
 8 files changed, 130 insertions(+), 13 deletions(-)

(limited to 'include/uapi')

diff --git a/arch/x86/net/bpf_jit_comp.c b/arch/x86/net/bpf_jit_comp.c
index d6349e930b06..b1fd000feb89 100644
--- a/arch/x86/net/bpf_jit_comp.c
+++ b/arch/x86/net/bpf_jit_comp.c
@@ -1362,7 +1362,7 @@ static void restore_regs(const struct btf_func_model *m, u8 **prog, int nr_args,
 }
 
 static int invoke_bpf_prog(const struct btf_func_model *m, u8 **pprog,
-			   struct bpf_prog *p, int stack_size)
+			   struct bpf_prog *p, int stack_size, bool mod_ret)
 {
 	u8 *prog = *pprog;
 	int cnt = 0;
@@ -1383,6 +1383,13 @@ static int invoke_bpf_prog(const struct btf_func_model *m, u8 **pprog,
 	if (emit_call(&prog, p->bpf_func, prog))
 		return -EINVAL;
 
+	/* BPF_TRAMP_MODIFY_RETURN trampolines can modify the return
+	 * of the previous call which is then passed on the stack to
+	 * the next BPF program.
+	 */
+	if (mod_ret)
+		emit_stx(&prog, BPF_DW, BPF_REG_FP, BPF_REG_0, -8);
+
 	/* arg1: mov rdi, progs[i] */
 	emit_mov_imm64(&prog, BPF_REG_1, (long) p >> 32,
 		       (u32) (long) p);
@@ -1442,6 +1449,23 @@ static int emit_cond_near_jump(u8 **pprog, void *func, void *ip, u8 jmp_cond)
 	return 0;
 }
 
+static int emit_mod_ret_check_imm8(u8 **pprog, int value)
+{
+	u8 *prog = *pprog;
+	int cnt = 0;
+
+	if (!is_imm8(value))
+		return -EINVAL;
+
+	if (value == 0)
+		EMIT2(0x85, add_2reg(0xC0, BPF_REG_0, BPF_REG_0));
+	else
+		EMIT3(0x83, add_1reg(0xF8, BPF_REG_0), value);
+
+	*pprog = prog;
+	return 0;
+}
+
 static int invoke_bpf(const struct btf_func_model *m, u8 **pprog,
 		      struct bpf_tramp_progs *tp, int stack_size)
 {
@@ -1449,9 +1473,49 @@ static int invoke_bpf(const struct btf_func_model *m, u8 **pprog,
 	u8 *prog = *pprog;
 
 	for (i = 0; i < tp->nr_progs; i++) {
-		if (invoke_bpf_prog(m, &prog, tp->progs[i], stack_size))
+		if (invoke_bpf_prog(m, &prog, tp->progs[i], stack_size, false))
+			return -EINVAL;
+	}
+	*pprog = prog;
+	return 0;
+}
+
+static int invoke_bpf_mod_ret(const struct btf_func_model *m, u8 **pprog,
+			      struct bpf_tramp_progs *tp, int stack_size,
+			      u8 **branches)
+{
+	u8 *prog = *pprog;
+	int i;
+
+	/* The first fmod_ret program will receive a garbage return value.
+	 * Set this to 0 to avoid confusing the program.
+	 */
+	emit_mov_imm32(&prog, false, BPF_REG_0, 0);
+	emit_stx(&prog, BPF_DW, BPF_REG_FP, BPF_REG_0, -8);
+	for (i = 0; i < tp->nr_progs; i++) {
+		if (invoke_bpf_prog(m, &prog, tp->progs[i], stack_size, true))
 			return -EINVAL;
+
+		/* Generate a branch:
+		 *
+		 * if (ret !=  0)
+		 *	goto do_fexit;
+		 *
+		 * If needed this can be extended to any integer value which can
+		 * be passed by user-space when the program is loaded.
+		 */
+		if (emit_mod_ret_check_imm8(&prog, 0))
+			return -EINVAL;
+
+		/* Save the location of the branch and Generate 6 nops
+		 * (4 bytes for an offset and 2 bytes for the jump) These nops
+		 * are replaced with a conditional jump once do_fexit (i.e. the
+		 * start of the fexit invocation) is finalized.
+		 */
+		branches[i] = prog;
+		emit_nops(&prog, 4 + 2);
 	}
+
 	*pprog = prog;
 	return 0;
 }
@@ -1521,10 +1585,12 @@ int arch_prepare_bpf_trampoline(void *image, void *image_end,
 				struct bpf_tramp_progs *tprogs,
 				void *orig_call)
 {
-	int cnt = 0, nr_args = m->nr_args;
+	int ret, i, cnt = 0, nr_args = m->nr_args;
 	int stack_size = nr_args * 8;
 	struct bpf_tramp_progs *fentry = &tprogs[BPF_TRAMP_FENTRY];
 	struct bpf_tramp_progs *fexit = &tprogs[BPF_TRAMP_FEXIT];
+	struct bpf_tramp_progs *fmod_ret = &tprogs[BPF_TRAMP_MODIFY_RETURN];
+	u8 **branches = NULL;
 	u8 *prog;
 
 	/* x86-64 supports up to 6 arguments. 7+ can be added in the future */
@@ -1557,24 +1623,60 @@ int arch_prepare_bpf_trampoline(void *image, void *image_end,
 		if (invoke_bpf(m, &prog, fentry, stack_size))
 			return -EINVAL;
 
+	if (fmod_ret->nr_progs) {
+		branches = kcalloc(fmod_ret->nr_progs, sizeof(u8 *),
+				   GFP_KERNEL);
+		if (!branches)
+			return -ENOMEM;
+
+		if (invoke_bpf_mod_ret(m, &prog, fmod_ret, stack_size,
+				       branches)) {
+			ret = -EINVAL;
+			goto cleanup;
+		}
+	}
+
 	if (flags & BPF_TRAMP_F_CALL_ORIG) {
-		if (fentry->nr_progs)
+		if (fentry->nr_progs || fmod_ret->nr_progs)
 			restore_regs(m, &prog, nr_args, stack_size);
 
 		/* call original function */
-		if (emit_call(&prog, orig_call, prog))
-			return -EINVAL;
+		if (emit_call(&prog, orig_call, prog)) {
+			ret = -EINVAL;
+			goto cleanup;
+		}
 		/* remember return value in a stack for bpf prog to access */
 		emit_stx(&prog, BPF_DW, BPF_REG_FP, BPF_REG_0, -8);
 	}
 
+	if (fmod_ret->nr_progs) {
+		/* From Intel 64 and IA-32 Architectures Optimization
+		 * Reference Manual, 3.4.1.4 Code Alignment, Assembly/Compiler
+		 * Coding Rule 11: All branch targets should be 16-byte
+		 * aligned.
+		 */
+		emit_align(&prog, 16);
+		/* Update the branches saved in invoke_bpf_mod_ret with the
+		 * aligned address of do_fexit.
+		 */
+		for (i = 0; i < fmod_ret->nr_progs; i++)
+			emit_cond_near_jump(&branches[i], prog, branches[i],
+					    X86_JNE);
+	}
+
 	if (fexit->nr_progs)
-		if (invoke_bpf(m, &prog, fexit, stack_size))
-			return -EINVAL;
+		if (invoke_bpf(m, &prog, fexit, stack_size)) {
+			ret = -EINVAL;
+			goto cleanup;
+		}
 
 	if (flags & BPF_TRAMP_F_RESTORE_REGS)
 		restore_regs(m, &prog, nr_args, stack_size);
 
+	/* This needs to be done regardless. If there were fmod_ret programs,
+	 * the return value is only updated on the stack and still needs to be
+	 * restored to R0.
+	 */
 	if (flags & BPF_TRAMP_F_CALL_ORIG)
 		/* restore original return value back into RAX */
 		emit_ldx(&prog, BPF_DW, BPF_REG_0, BPF_REG_FP, -8);
@@ -1586,9 +1688,15 @@ int arch_prepare_bpf_trampoline(void *image, void *image_end,
 		EMIT4(0x48, 0x83, 0xC4, 8); /* add rsp, 8 */
 	EMIT1(0xC3); /* ret */
 	/* Make sure the trampoline generation logic doesn't overflow */
-	if (WARN_ON_ONCE(prog > (u8 *)image_end - BPF_INSN_SAFETY))
-		return -EFAULT;
-	return prog - (u8 *)image;
+	if (WARN_ON_ONCE(prog > (u8 *)image_end - BPF_INSN_SAFETY)) {
+		ret = -EFAULT;
+		goto cleanup;
+	}
+	ret = prog - (u8 *)image;
+
+cleanup:
+	kfree(branches);
+	return ret;
 }
 
 static int emit_fallback_jump(u8 **pprog)
diff --git a/include/linux/bpf.h b/include/linux/bpf.h
index 98ec10b23dbb..f748b31e5888 100644
--- a/include/linux/bpf.h
+++ b/include/linux/bpf.h
@@ -474,6 +474,7 @@ void notrace __bpf_prog_exit(struct bpf_prog *prog, u64 start);
 enum bpf_tramp_prog_type {
 	BPF_TRAMP_FENTRY,
 	BPF_TRAMP_FEXIT,
+	BPF_TRAMP_MODIFY_RETURN,
 	BPF_TRAMP_MAX,
 	BPF_TRAMP_REPLACE, /* more than MAX */
 };
diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h
index d6b33ea27bcc..40b2d9476268 100644
--- a/include/uapi/linux/bpf.h
+++ b/include/uapi/linux/bpf.h
@@ -210,6 +210,7 @@ enum bpf_attach_type {
 	BPF_TRACE_RAW_TP,
 	BPF_TRACE_FENTRY,
 	BPF_TRACE_FEXIT,
+	BPF_MODIFY_RETURN,
 	__MAX_BPF_ATTACH_TYPE
 };
 
diff --git a/kernel/bpf/btf.c b/kernel/bpf/btf.c
index 787140095e58..30841fb8b3c0 100644
--- a/kernel/bpf/btf.c
+++ b/kernel/bpf/btf.c
@@ -3710,7 +3710,8 @@ bool btf_ctx_access(int off, int size, enum bpf_access_type type,
 		nr_args--;
 	}
 
-	if (prog->expected_attach_type == BPF_TRACE_FEXIT &&
+	if ((prog->expected_attach_type == BPF_TRACE_FEXIT ||
+	     prog->expected_attach_type == BPF_MODIFY_RETURN) &&
 	    arg == nr_args) {
 		if (!t)
 			/* Default prog with 5 args. 6th arg is retval. */
diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
index 13de65363ba2..7ce0815793dd 100644
--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c
@@ -2324,6 +2324,7 @@ static int bpf_tracing_prog_attach(struct bpf_prog *prog)
 
 	if (prog->expected_attach_type != BPF_TRACE_FENTRY &&
 	    prog->expected_attach_type != BPF_TRACE_FEXIT &&
+	    prog->expected_attach_type != BPF_MODIFY_RETURN &&
 	    prog->type != BPF_PROG_TYPE_EXT) {
 		err = -EINVAL;
 		goto out_put_prog;
diff --git a/kernel/bpf/trampoline.c b/kernel/bpf/trampoline.c
index 546198f6f307..221a17af1f81 100644
--- a/kernel/bpf/trampoline.c
+++ b/kernel/bpf/trampoline.c
@@ -232,7 +232,8 @@ static int bpf_trampoline_update(struct bpf_trampoline *tr)
 		goto out;
 	}
 
-	if (tprogs[BPF_TRAMP_FEXIT].nr_progs)
+	if (tprogs[BPF_TRAMP_FEXIT].nr_progs ||
+	    tprogs[BPF_TRAMP_MODIFY_RETURN].nr_progs)
 		flags = BPF_TRAMP_F_CALL_ORIG | BPF_TRAMP_F_SKIP_FRAME;
 
 	/* Though the second half of trampoline page is unused a task could be
@@ -269,6 +270,8 @@ static enum bpf_tramp_prog_type bpf_attach_type_to_tramp(enum bpf_attach_type t)
 	switch (t) {
 	case BPF_TRACE_FENTRY:
 		return BPF_TRAMP_FENTRY;
+	case BPF_MODIFY_RETURN:
+		return BPF_TRAMP_MODIFY_RETURN;
 	case BPF_TRACE_FEXIT:
 		return BPF_TRAMP_FEXIT;
 	default:
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index 289383edfc8c..2460c8e6b5be 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -9950,6 +9950,7 @@ static int check_attach_btf_id(struct bpf_verifier_env *env)
 		if (!prog_extension)
 			return -EINVAL;
 		/* fallthrough */
+	case BPF_MODIFY_RETURN:
 	case BPF_TRACE_FENTRY:
 	case BPF_TRACE_FEXIT:
 		if (!btf_type_is_func(t)) {
diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h
index d6b33ea27bcc..40b2d9476268 100644
--- a/tools/include/uapi/linux/bpf.h
+++ b/tools/include/uapi/linux/bpf.h
@@ -210,6 +210,7 @@ enum bpf_attach_type {
 	BPF_TRACE_RAW_TP,
 	BPF_TRACE_FENTRY,
 	BPF_TRACE_FEXIT,
+	BPF_MODIFY_RETURN,
 	__MAX_BPF_ATTACH_TYPE
 };
 
-- 
cgit v1.2.3


From b4490c5c4e023f09b7d27c9a9d3e7ad7d09ea6bf Mon Sep 17 00:00:00 2001
From: Carlos Neira <cneirabustos@gmail.com>
Date: Wed, 4 Mar 2020 17:41:56 -0300
Subject: bpf: Added new helper bpf_get_ns_current_pid_tgid

New bpf helper bpf_get_ns_current_pid_tgid,
This helper will return pid and tgid from current task
which namespace matches dev_t and inode number provided,
this will allows us to instrument a process inside a container.

Signed-off-by: Carlos Neira <cneirabustos@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20200304204157.58695-3-cneirabustos@gmail.com
---
 include/linux/bpf.h            |  1 +
 include/uapi/linux/bpf.h       | 20 ++++++++++++++++++-
 kernel/bpf/core.c              |  1 +
 kernel/bpf/helpers.c           | 45 ++++++++++++++++++++++++++++++++++++++++++
 kernel/trace/bpf_trace.c       |  2 ++
 scripts/bpf_helpers_doc.py     |  1 +
 tools/include/uapi/linux/bpf.h | 20 ++++++++++++++++++-
 7 files changed, 88 insertions(+), 2 deletions(-)

(limited to 'include/uapi')

diff --git a/include/linux/bpf.h b/include/linux/bpf.h
index 4fd91b7c95ea..4ec835334a1f 100644
--- a/include/linux/bpf.h
+++ b/include/linux/bpf.h
@@ -1497,6 +1497,7 @@ extern const struct bpf_func_proto bpf_strtol_proto;
 extern const struct bpf_func_proto bpf_strtoul_proto;
 extern const struct bpf_func_proto bpf_tcp_sock_proto;
 extern const struct bpf_func_proto bpf_jiffies64_proto;
+extern const struct bpf_func_proto bpf_get_ns_current_pid_tgid_proto;
 
 /* Shared helpers among cBPF and eBPF. */
 void bpf_user_rnd_init_once(void);
diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h
index 40b2d9476268..15b239da775b 100644
--- a/include/uapi/linux/bpf.h
+++ b/include/uapi/linux/bpf.h
@@ -2914,6 +2914,19 @@ union bpf_attr {
  *		of sizeof(struct perf_branch_entry).
  *
  *		**-ENOENT** if architecture does not support branch records.
+ *
+ * int bpf_get_ns_current_pid_tgid(u64 dev, u64 ino, struct bpf_pidns_info *nsdata, u32 size)
+ *	Description
+ *		Returns 0 on success, values for *pid* and *tgid* as seen from the current
+ *		*namespace* will be returned in *nsdata*.
+ *
+ *		On failure, the returned value is one of the following:
+ *
+ *		**-EINVAL** if dev and inum supplied don't match dev_t and inode number
+ *              with nsfs of current task, or if dev conversion to dev_t lost high bits.
+ *
+ *		**-ENOENT** if pidns does not exists for the current task.
+ *
  */
 #define __BPF_FUNC_MAPPER(FN)		\
 	FN(unspec),			\
@@ -3035,7 +3048,8 @@ union bpf_attr {
 	FN(tcp_send_ack),		\
 	FN(send_signal_thread),		\
 	FN(jiffies64),			\
-	FN(read_branch_records),
+	FN(read_branch_records),	\
+	FN(get_ns_current_pid_tgid),
 
 /* integer value in 'imm' field of BPF_CALL instruction selects which helper
  * function eBPF program intends to call
@@ -3829,4 +3843,8 @@ struct bpf_sockopt {
 	__s32	retval;
 };
 
+struct bpf_pidns_info {
+	__u32 pid;
+	__u32 tgid;
+};
 #endif /* _UAPI__LINUX_BPF_H__ */
diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c
index 973a20d49749..0f9ca46e1978 100644
--- a/kernel/bpf/core.c
+++ b/kernel/bpf/core.c
@@ -2149,6 +2149,7 @@ const struct bpf_func_proto bpf_get_current_uid_gid_proto __weak;
 const struct bpf_func_proto bpf_get_current_comm_proto __weak;
 const struct bpf_func_proto bpf_get_current_cgroup_id_proto __weak;
 const struct bpf_func_proto bpf_get_local_storage_proto __weak;
+const struct bpf_func_proto bpf_get_ns_current_pid_tgid_proto __weak;
 
 const struct bpf_func_proto * __weak bpf_get_trace_printk_proto(void)
 {
diff --git a/kernel/bpf/helpers.c b/kernel/bpf/helpers.c
index d8b7b110a1c5..01878db15eaf 100644
--- a/kernel/bpf/helpers.c
+++ b/kernel/bpf/helpers.c
@@ -12,6 +12,8 @@
 #include <linux/filter.h>
 #include <linux/ctype.h>
 #include <linux/jiffies.h>
+#include <linux/pid_namespace.h>
+#include <linux/proc_ns.h>
 
 #include "../../lib/kstrtox.h"
 
@@ -499,3 +501,46 @@ const struct bpf_func_proto bpf_strtoul_proto = {
 	.arg4_type	= ARG_PTR_TO_LONG,
 };
 #endif
+
+BPF_CALL_4(bpf_get_ns_current_pid_tgid, u64, dev, u64, ino,
+	   struct bpf_pidns_info *, nsdata, u32, size)
+{
+	struct task_struct *task = current;
+	struct pid_namespace *pidns;
+	int err = -EINVAL;
+
+	if (unlikely(size != sizeof(struct bpf_pidns_info)))
+		goto clear;
+
+	if (unlikely((u64)(dev_t)dev != dev))
+		goto clear;
+
+	if (unlikely(!task))
+		goto clear;
+
+	pidns = task_active_pid_ns(task);
+	if (unlikely(!pidns)) {
+		err = -ENOENT;
+		goto clear;
+	}
+
+	if (!ns_match(&pidns->ns, (dev_t)dev, ino))
+		goto clear;
+
+	nsdata->pid = task_pid_nr_ns(task, pidns);
+	nsdata->tgid = task_tgid_nr_ns(task, pidns);
+	return 0;
+clear:
+	memset((void *)nsdata, 0, (size_t) size);
+	return err;
+}
+
+const struct bpf_func_proto bpf_get_ns_current_pid_tgid_proto = {
+	.func		= bpf_get_ns_current_pid_tgid,
+	.gpl_only	= false,
+	.ret_type	= RET_INTEGER,
+	.arg1_type	= ARG_ANYTHING,
+	.arg2_type	= ARG_ANYTHING,
+	.arg3_type      = ARG_PTR_TO_UNINIT_MEM,
+	.arg4_type      = ARG_CONST_SIZE,
+};
diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c
index 6a490d8ce9de..b5071c7e93ca 100644
--- a/kernel/trace/bpf_trace.c
+++ b/kernel/trace/bpf_trace.c
@@ -843,6 +843,8 @@ tracing_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
 		return &bpf_send_signal_thread_proto;
 	case BPF_FUNC_perf_event_read_value:
 		return &bpf_perf_event_read_value_proto;
+	case BPF_FUNC_get_ns_current_pid_tgid:
+		return &bpf_get_ns_current_pid_tgid_proto;
 	default:
 		return NULL;
 	}
diff --git a/scripts/bpf_helpers_doc.py b/scripts/bpf_helpers_doc.py
index cebed6fb5bbb..c1e2b5410faa 100755
--- a/scripts/bpf_helpers_doc.py
+++ b/scripts/bpf_helpers_doc.py
@@ -435,6 +435,7 @@ class PrinterHelpers(Printer):
             'struct bpf_fib_lookup',
             'struct bpf_perf_event_data',
             'struct bpf_perf_event_value',
+            'struct bpf_pidns_info',
             'struct bpf_sock',
             'struct bpf_sock_addr',
             'struct bpf_sock_ops',
diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h
index 40b2d9476268..15b239da775b 100644
--- a/tools/include/uapi/linux/bpf.h
+++ b/tools/include/uapi/linux/bpf.h
@@ -2914,6 +2914,19 @@ union bpf_attr {
  *		of sizeof(struct perf_branch_entry).
  *
  *		**-ENOENT** if architecture does not support branch records.
+ *
+ * int bpf_get_ns_current_pid_tgid(u64 dev, u64 ino, struct bpf_pidns_info *nsdata, u32 size)
+ *	Description
+ *		Returns 0 on success, values for *pid* and *tgid* as seen from the current
+ *		*namespace* will be returned in *nsdata*.
+ *
+ *		On failure, the returned value is one of the following:
+ *
+ *		**-EINVAL** if dev and inum supplied don't match dev_t and inode number
+ *              with nsfs of current task, or if dev conversion to dev_t lost high bits.
+ *
+ *		**-ENOENT** if pidns does not exists for the current task.
+ *
  */
 #define __BPF_FUNC_MAPPER(FN)		\
 	FN(unspec),			\
@@ -3035,7 +3048,8 @@ union bpf_attr {
 	FN(tcp_send_ack),		\
 	FN(send_signal_thread),		\
 	FN(jiffies64),			\
-	FN(read_branch_records),
+	FN(read_branch_records),	\
+	FN(get_ns_current_pid_tgid),
 
 /* integer value in 'imm' field of BPF_CALL instruction selects which helper
  * function eBPF program intends to call
@@ -3829,4 +3843,8 @@ struct bpf_sockopt {
 	__s32	retval;
 };
 
+struct bpf_pidns_info {
+	__u32 pid;
+	__u32 tgid;
+};
 #endif /* _UAPI__LINUX_BPF_H__ */
-- 
cgit v1.2.3


From d831ee84bfc9173eecf30dbbc2553ae81b996c60 Mon Sep 17 00:00:00 2001
From: Eelco Chaudron <echaudro@redhat.com>
Date: Fri, 6 Mar 2020 08:59:23 +0000
Subject: bpf: Add bpf_xdp_output() helper
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Introduce new helper that reuses existing xdp perf_event output
implementation, but can be called from raw_tracepoint programs
that receive 'struct xdp_buff *' as a tracepoint argument.

Signed-off-by: Eelco Chaudron <echaudro@redhat.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Acked-by: Toke Høiland-Jørgensen <toke@redhat.com>
Link: https://lore.kernel.org/bpf/158348514556.2239.11050972434793741444.stgit@xdp-tutorial
---
 include/uapi/linux/bpf.h                           | 26 ++++++++++-
 kernel/bpf/verifier.c                              |  4 +-
 kernel/trace/bpf_trace.c                           |  3 ++
 net/core/filter.c                                  | 16 ++++++-
 tools/include/uapi/linux/bpf.h                     | 26 ++++++++++-
 .../testing/selftests/bpf/prog_tests/xdp_bpf2bpf.c | 53 ++++++++++++++++++++++
 .../testing/selftests/bpf/progs/test_xdp_bpf2bpf.c | 24 ++++++++++
 7 files changed, 148 insertions(+), 4 deletions(-)

(limited to 'include/uapi')

diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h
index 15b239da775b..5d01c5c7e598 100644
--- a/include/uapi/linux/bpf.h
+++ b/include/uapi/linux/bpf.h
@@ -2927,6 +2927,29 @@ union bpf_attr {
  *
  *		**-ENOENT** if pidns does not exists for the current task.
  *
+ * int bpf_xdp_output(void *ctx, struct bpf_map *map, u64 flags, void *data, u64 size)
+ *	Description
+ *		Write raw *data* blob into a special BPF perf event held by
+ *		*map* of type **BPF_MAP_TYPE_PERF_EVENT_ARRAY**. This perf
+ *		event must have the following attributes: **PERF_SAMPLE_RAW**
+ *		as **sample_type**, **PERF_TYPE_SOFTWARE** as **type**, and
+ *		**PERF_COUNT_SW_BPF_OUTPUT** as **config**.
+ *
+ *		The *flags* are used to indicate the index in *map* for which
+ *		the value must be put, masked with **BPF_F_INDEX_MASK**.
+ *		Alternatively, *flags* can be set to **BPF_F_CURRENT_CPU**
+ *		to indicate that the index of the current CPU core should be
+ *		used.
+ *
+ *		The value to write, of *size*, is passed through eBPF stack and
+ *		pointed by *data*.
+ *
+ *		*ctx* is a pointer to in-kernel struct xdp_buff.
+ *
+ *		This helper is similar to **bpf_perf_eventoutput**\ () but
+ *		restricted to raw_tracepoint bpf programs.
+ *	Return
+ *		0 on success, or a negative error in case of failure.
  */
 #define __BPF_FUNC_MAPPER(FN)		\
 	FN(unspec),			\
@@ -3049,7 +3072,8 @@ union bpf_attr {
 	FN(send_signal_thread),		\
 	FN(jiffies64),			\
 	FN(read_branch_records),	\
-	FN(get_ns_current_pid_tgid),
+	FN(get_ns_current_pid_tgid),	\
+	FN(xdp_output),
 
 /* integer value in 'imm' field of BPF_CALL instruction selects which helper
  * function eBPF program intends to call
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index 55d376c53f7d..745f3cfdf3b2 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -3650,7 +3650,8 @@ static int check_map_func_compatibility(struct bpf_verifier_env *env,
 		if (func_id != BPF_FUNC_perf_event_read &&
 		    func_id != BPF_FUNC_perf_event_output &&
 		    func_id != BPF_FUNC_skb_output &&
-		    func_id != BPF_FUNC_perf_event_read_value)
+		    func_id != BPF_FUNC_perf_event_read_value &&
+		    func_id != BPF_FUNC_xdp_output)
 			goto error;
 		break;
 	case BPF_MAP_TYPE_STACK_TRACE:
@@ -3740,6 +3741,7 @@ static int check_map_func_compatibility(struct bpf_verifier_env *env,
 	case BPF_FUNC_perf_event_output:
 	case BPF_FUNC_perf_event_read_value:
 	case BPF_FUNC_skb_output:
+	case BPF_FUNC_xdp_output:
 		if (map->map_type != BPF_MAP_TYPE_PERF_EVENT_ARRAY)
 			goto error;
 		break;
diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c
index b5071c7e93ca..e619eedb5919 100644
--- a/kernel/trace/bpf_trace.c
+++ b/kernel/trace/bpf_trace.c
@@ -1145,6 +1145,7 @@ static const struct bpf_func_proto bpf_perf_event_output_proto_raw_tp = {
 };
 
 extern const struct bpf_func_proto bpf_skb_output_proto;
+extern const struct bpf_func_proto bpf_xdp_output_proto;
 
 BPF_CALL_3(bpf_get_stackid_raw_tp, struct bpf_raw_tracepoint_args *, args,
 	   struct bpf_map *, map, u64, flags)
@@ -1220,6 +1221,8 @@ tracing_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
 #ifdef CONFIG_NET
 	case BPF_FUNC_skb_output:
 		return &bpf_skb_output_proto;
+	case BPF_FUNC_xdp_output:
+		return &bpf_xdp_output_proto;
 #endif
 	default:
 		return raw_tp_prog_func_proto(func_id, prog);
diff --git a/net/core/filter.c b/net/core/filter.c
index cd0a532db4e7..22219544410f 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -4061,7 +4061,8 @@ BPF_CALL_5(bpf_xdp_event_output, struct xdp_buff *, xdp, struct bpf_map *, map,
 
 	if (unlikely(flags & ~(BPF_F_CTXLEN_MASK | BPF_F_INDEX_MASK)))
 		return -EINVAL;
-	if (unlikely(xdp_size > (unsigned long)(xdp->data_end - xdp->data)))
+	if (unlikely(!xdp ||
+		     xdp_size > (unsigned long)(xdp->data_end - xdp->data)))
 		return -EFAULT;
 
 	return bpf_event_output(map, flags, meta, meta_size, xdp->data,
@@ -4079,6 +4080,19 @@ static const struct bpf_func_proto bpf_xdp_event_output_proto = {
 	.arg5_type	= ARG_CONST_SIZE_OR_ZERO,
 };
 
+static int bpf_xdp_output_btf_ids[5];
+const struct bpf_func_proto bpf_xdp_output_proto = {
+	.func		= bpf_xdp_event_output,
+	.gpl_only	= true,
+	.ret_type	= RET_INTEGER,
+	.arg1_type	= ARG_PTR_TO_BTF_ID,
+	.arg2_type	= ARG_CONST_MAP_PTR,
+	.arg3_type	= ARG_ANYTHING,
+	.arg4_type	= ARG_PTR_TO_MEM,
+	.arg5_type	= ARG_CONST_SIZE_OR_ZERO,
+	.btf_id		= bpf_xdp_output_btf_ids,
+};
+
 BPF_CALL_1(bpf_get_socket_cookie, struct sk_buff *, skb)
 {
 	return skb->sk ? sock_gen_cookie(skb->sk) : 0;
diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h
index 15b239da775b..5d01c5c7e598 100644
--- a/tools/include/uapi/linux/bpf.h
+++ b/tools/include/uapi/linux/bpf.h
@@ -2927,6 +2927,29 @@ union bpf_attr {
  *
  *		**-ENOENT** if pidns does not exists for the current task.
  *
+ * int bpf_xdp_output(void *ctx, struct bpf_map *map, u64 flags, void *data, u64 size)
+ *	Description
+ *		Write raw *data* blob into a special BPF perf event held by
+ *		*map* of type **BPF_MAP_TYPE_PERF_EVENT_ARRAY**. This perf
+ *		event must have the following attributes: **PERF_SAMPLE_RAW**
+ *		as **sample_type**, **PERF_TYPE_SOFTWARE** as **type**, and
+ *		**PERF_COUNT_SW_BPF_OUTPUT** as **config**.
+ *
+ *		The *flags* are used to indicate the index in *map* for which
+ *		the value must be put, masked with **BPF_F_INDEX_MASK**.
+ *		Alternatively, *flags* can be set to **BPF_F_CURRENT_CPU**
+ *		to indicate that the index of the current CPU core should be
+ *		used.
+ *
+ *		The value to write, of *size*, is passed through eBPF stack and
+ *		pointed by *data*.
+ *
+ *		*ctx* is a pointer to in-kernel struct xdp_buff.
+ *
+ *		This helper is similar to **bpf_perf_eventoutput**\ () but
+ *		restricted to raw_tracepoint bpf programs.
+ *	Return
+ *		0 on success, or a negative error in case of failure.
  */
 #define __BPF_FUNC_MAPPER(FN)		\
 	FN(unspec),			\
@@ -3049,7 +3072,8 @@ union bpf_attr {
 	FN(send_signal_thread),		\
 	FN(jiffies64),			\
 	FN(read_branch_records),	\
-	FN(get_ns_current_pid_tgid),
+	FN(get_ns_current_pid_tgid),	\
+	FN(xdp_output),
 
 /* integer value in 'imm' field of BPF_CALL instruction selects which helper
  * function eBPF program intends to call
diff --git a/tools/testing/selftests/bpf/prog_tests/xdp_bpf2bpf.c b/tools/testing/selftests/bpf/prog_tests/xdp_bpf2bpf.c
index 4ba011031d4c..a0f688c37023 100644
--- a/tools/testing/selftests/bpf/prog_tests/xdp_bpf2bpf.c
+++ b/tools/testing/selftests/bpf/prog_tests/xdp_bpf2bpf.c
@@ -4,17 +4,51 @@
 #include "test_xdp.skel.h"
 #include "test_xdp_bpf2bpf.skel.h"
 
+struct meta {
+	int ifindex;
+	int pkt_len;
+};
+
+static void on_sample(void *ctx, int cpu, void *data, __u32 size)
+{
+	int duration = 0;
+	struct meta *meta = (struct meta *)data;
+	struct ipv4_packet *trace_pkt_v4 = data + sizeof(*meta);
+
+	if (CHECK(size < sizeof(pkt_v4) + sizeof(*meta),
+		  "check_size", "size %u < %zu\n",
+		  size, sizeof(pkt_v4) + sizeof(*meta)))
+		return;
+
+	if (CHECK(meta->ifindex != if_nametoindex("lo"), "check_meta_ifindex",
+		  "meta->ifindex = %d\n", meta->ifindex))
+		return;
+
+	if (CHECK(meta->pkt_len != sizeof(pkt_v4), "check_meta_pkt_len",
+		  "meta->pkt_len = %zd\n", sizeof(pkt_v4)))
+		return;
+
+	if (CHECK(memcmp(trace_pkt_v4, &pkt_v4, sizeof(pkt_v4)),
+		  "check_packet_content", "content not the same\n"))
+		return;
+
+	*(bool *)ctx = true;
+}
+
 void test_xdp_bpf2bpf(void)
 {
 	__u32 duration = 0, retval, size;
 	char buf[128];
 	int err, pkt_fd, map_fd;
+	bool passed = false;
 	struct iphdr *iph = (void *)buf + sizeof(struct ethhdr);
 	struct iptnl_info value4 = {.family = AF_INET};
 	struct test_xdp *pkt_skel = NULL;
 	struct test_xdp_bpf2bpf *ftrace_skel = NULL;
 	struct vip key4 = {.protocol = 6, .family = AF_INET};
 	struct bpf_program *prog;
+	struct perf_buffer *pb = NULL;
+	struct perf_buffer_opts pb_opts = {};
 
 	/* Load XDP program to introspect */
 	pkt_skel = test_xdp__open_and_load();
@@ -50,6 +84,14 @@ void test_xdp_bpf2bpf(void)
 	if (CHECK(err, "ftrace_attach", "ftrace attach failed: %d\n", err))
 		goto out;
 
+	/* Set up perf buffer */
+	pb_opts.sample_cb = on_sample;
+	pb_opts.ctx = &passed;
+	pb = perf_buffer__new(bpf_map__fd(ftrace_skel->maps.perf_buf_map),
+			      1, &pb_opts);
+	if (CHECK(IS_ERR(pb), "perf_buf__new", "err %ld\n", PTR_ERR(pb)))
+		goto out;
+
 	/* Run test program */
 	err = bpf_prog_test_run(pkt_fd, 1, &pkt_v4, sizeof(pkt_v4),
 				buf, &size, &retval, &duration);
@@ -60,6 +102,15 @@ void test_xdp_bpf2bpf(void)
 		  err, errno, retval, size))
 		goto out;
 
+	/* Make sure bpf_xdp_output() was triggered and it sent the expected
+	 * data to the perf ring buffer.
+	 */
+	err = perf_buffer__poll(pb, 100);
+	if (CHECK(err < 0, "perf_buffer__poll", "err %d\n", err))
+		goto out;
+
+	CHECK_FAIL(!passed);
+
 	/* Verify test results */
 	if (CHECK(ftrace_skel->bss->test_result_fentry != if_nametoindex("lo"),
 		  "result", "fentry failed err %llu\n",
@@ -70,6 +121,8 @@ void test_xdp_bpf2bpf(void)
 	      "fexit failed err %llu\n", ftrace_skel->bss->test_result_fexit);
 
 out:
+	if (pb)
+		perf_buffer__free(pb);
 	test_xdp__destroy(pkt_skel);
 	test_xdp_bpf2bpf__destroy(ftrace_skel);
 }
diff --git a/tools/testing/selftests/bpf/progs/test_xdp_bpf2bpf.c b/tools/testing/selftests/bpf/progs/test_xdp_bpf2bpf.c
index 42dd2fedd588..a038e827f850 100644
--- a/tools/testing/selftests/bpf/progs/test_xdp_bpf2bpf.c
+++ b/tools/testing/selftests/bpf/progs/test_xdp_bpf2bpf.c
@@ -3,6 +3,8 @@
 #include <bpf/bpf_tracing.h>
 #include <bpf/bpf_helpers.h>
 
+char _license[] SEC("license") = "GPL";
+
 struct net_device {
 	/* Structure does not need to contain all entries,
 	 * as "preserve_access_index" will use BTF to fix this...
@@ -27,10 +29,32 @@ struct xdp_buff {
 	struct xdp_rxq_info *rxq;
 } __attribute__((preserve_access_index));
 
+struct meta {
+	int ifindex;
+	int pkt_len;
+};
+
+struct {
+	__uint(type, BPF_MAP_TYPE_PERF_EVENT_ARRAY);
+	__uint(key_size, sizeof(int));
+	__uint(value_size, sizeof(int));
+} perf_buf_map SEC(".maps");
+
 __u64 test_result_fentry = 0;
 SEC("fentry/FUNC")
 int BPF_PROG(trace_on_entry, struct xdp_buff *xdp)
 {
+	struct meta meta;
+	void *data_end = (void *)(long)xdp->data_end;
+	void *data = (void *)(long)xdp->data;
+
+	meta.ifindex = xdp->rxq->dev->ifindex;
+	meta.pkt_len = data_end - data;
+	bpf_xdp_output(xdp, &perf_buf_map,
+		       ((__u64) meta.pkt_len << 32) |
+		       BPF_F_CURRENT_CPU,
+		       &meta, sizeof(meta));
+
 	test_result_fentry = xdp->rxq->dev->ifindex;
 	return 0;
 }
-- 
cgit v1.2.3