Merge branch 'bpf-selftests-improve-and-use-library'

Mickaël Salaün says:

====================
Improve BPF selftests and use the library (net-next tree)

This series brings some fixes to selftests, add the ability to test
unprivileged BPF programs as root and replace bpf_sys.h with calls to the BPF
library.

This is intended for the net-next tree and apply on c0e4dad ("net: dsa:
mv88e6xxx: Move forward declaration to where it is needed").

Changes since v4:
* align text for function calls as requested by Daniel Borkmann
  (bpf_load_program and bpf_map_update_elem)
* rebase

Changes since v3:
* keep the bzero() calls

Changes since v2:
* use the patches from two previous series (unprivileged tests and bpf_sys.h
  replacement)
* include one more stdint.h
* rebase on net-next
* add this cover letter

Changes since v1:
* exclude patches not intended for the net-next tree
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

tools/include/uapi/linux/bpf.h

@@ -63,6 +63,12 @@ struct bpf_insn {
 	__s32	imm;		/* signed immediate constant */
 };
 
+/* 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 */
+};
+
 /* BPF syscall commands, see bpf(2) man-page for details. */
 enum bpf_cmd {
 	BPF_MAP_CREATE,
@@ -89,6 +95,7 @@ enum bpf_map_type {
 	BPF_MAP_TYPE_CGROUP_ARRAY,
 	BPF_MAP_TYPE_LRU_HASH,
 	BPF_MAP_TYPE_LRU_PERCPU_HASH,
+	BPF_MAP_TYPE_LPM_TRIE,
 };
 
 enum bpf_prog_type {
@@ -430,6 +437,18 @@ union bpf_attr {
  *     @xdp_md: pointer to xdp_md
  *     @delta: An positive/negative integer to be added to xdp_md.data
  *     Return: 0 on success or negative on error
+ *
+ * int bpf_probe_read_str(void *dst, int size, const void *unsafe_ptr)
+ *     Copy a NUL terminated string from unsafe address. In case the string
+ *     length is smaller than size, the target is not padded with further NUL
+ *     bytes. In case the string length is larger than size, just count-1
+ *     bytes are copied and the last byte is set to NUL.
+ *     @dst: destination address
+ *     @size: maximum number of bytes to copy, including the trailing NUL
+ *     @unsafe_ptr: unsafe address
+ *     Return:
+ *       > 0 length of the string including the trailing NUL on success
+ *       < 0 error
  */
 #define __BPF_FUNC_MAPPER(FN)		\
 	FN(unspec),			\
@@ -476,7 +495,8 @@ union bpf_attr {
 	FN(set_hash_invalid),		\
 	FN(get_numa_node_id),		\
 	FN(skb_change_head),		\
-	FN(xdp_adjust_head),
+	FN(xdp_adjust_head),		\
+	FN(probe_read_str),
 
 /* integer value in 'imm' field of BPF_CALL instruction selects which helper
  * function eBPF program intends to call
@@ -502,6 +522,7 @@ enum bpf_func_id {
 /* 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)
 
 /* BPF_FUNC_clone_redirect and BPF_FUNC_redirect flags. */
 #define BPF_F_INGRESS			(1ULL << 0)

tools/lib/bpf/bpf.c

@@ -42,15 +42,21 @@
 # endif
 #endif
 
-static __u64 ptr_to_u64(void *ptr)
+static __u64 ptr_to_u64(const void *ptr)
 {
 	return (__u64) (unsigned long) ptr;
 }
 
 static int sys_bpf(enum bpf_cmd cmd, union bpf_attr *attr,
 		   unsigned int size)
 {
+#ifdef __NR_bpf
 	return syscall(__NR_bpf, cmd, attr, size);
+#else
+	fprintf(stderr, "No bpf syscall, kernel headers too old?\n");
+	errno = ENOSYS;
+	return -1;
+#endif
 }
 
 int bpf_create_map(enum bpf_map_type map_type, int key_size,
@@ -69,8 +75,8 @@ int bpf_create_map(enum bpf_map_type map_type, int key_size,
 	return sys_bpf(BPF_MAP_CREATE, &attr, sizeof(attr));
 }
 
-int bpf_load_program(enum bpf_prog_type type, struct bpf_insn *insns,
-		     size_t insns_cnt, char *license,
+int bpf_load_program(enum bpf_prog_type type, const struct bpf_insn *insns,
+		     size_t insns_cnt, const char *license,
 		     __u32 kern_version, char *log_buf, size_t log_buf_sz)
 {
 	int fd;
@@ -98,7 +104,7 @@ int bpf_load_program(enum bpf_prog_type type, struct bpf_insn *insns,
 	return sys_bpf(BPF_PROG_LOAD, &attr, sizeof(attr));
 }
 
-int bpf_map_update_elem(int fd, void *key, void *value,
+int bpf_map_update_elem(int fd, const void *key, const void *value,
 			__u64 flags)
 {
 	union bpf_attr attr;
@@ -112,7 +118,7 @@ int bpf_map_update_elem(int fd, void *key, void *value,
 	return sys_bpf(BPF_MAP_UPDATE_ELEM, &attr, sizeof(attr));
 }
 
-int bpf_map_lookup_elem(int fd, void *key, void *value)
+int bpf_map_lookup_elem(int fd, const void *key, void *value)
 {
 	union bpf_attr attr;
 
@@ -124,7 +130,7 @@ int bpf_map_lookup_elem(int fd, void *key, void *value)
 	return sys_bpf(BPF_MAP_LOOKUP_ELEM, &attr, sizeof(attr));
 }
 
-int bpf_map_delete_elem(int fd, void *key)
+int bpf_map_delete_elem(int fd, const void *key)
 {
 	union bpf_attr attr;
 
@@ -135,7 +141,7 @@ int bpf_map_delete_elem(int fd, void *key)
 	return sys_bpf(BPF_MAP_DELETE_ELEM, &attr, sizeof(attr));
 }
 
-int bpf_map_get_next_key(int fd, void *key, void *next_key)
+int bpf_map_get_next_key(int fd, const void *key, void *next_key)
 {
 	union bpf_attr attr;
 

tools/lib/bpf/bpf.h

@@ -28,17 +28,17 @@ int bpf_create_map(enum bpf_map_type map_type, int key_size, int value_size,
 
 /* Recommend log buffer size */
 #define BPF_LOG_BUF_SIZE 65536
-int bpf_load_program(enum bpf_prog_type type, struct bpf_insn *insns,
-		     size_t insns_cnt, char *license,
+int bpf_load_program(enum bpf_prog_type type, const struct bpf_insn *insns,
+		     size_t insns_cnt, const char *license,
 		     __u32 kern_version, char *log_buf,
 		     size_t log_buf_sz);
 
-int bpf_map_update_elem(int fd, void *key, void *value,
+int bpf_map_update_elem(int fd, const void *key, const void *value,
 			__u64 flags);
 
-int bpf_map_lookup_elem(int fd, void *key, void *value);
-int bpf_map_delete_elem(int fd, void *key);
-int bpf_map_get_next_key(int fd, void *key, void *next_key);
+int bpf_map_lookup_elem(int fd, const void *key, void *value);
+int bpf_map_delete_elem(int fd, const void *key);
+int bpf_map_get_next_key(int fd, const void *key, void *next_key);
 int bpf_obj_pin(int fd, const char *pathname);
 int bpf_obj_get(const char *pathname);
 int bpf_prog_attach(int prog_fd, int attachable_fd, enum bpf_attach_type type);

tools/testing/selftests/bpf/.gitignore

@@ -2,3 +2,4 @@ test_verifier
 test_maps
 test_lru_map
 test_lpm_map
+test_tag

tools/testing/selftests/bpf/Makefile

@@ -1,4 +1,4 @@
-CFLAGS += -Wall -O2 -I../../../../usr/include
+CFLAGS += -Wall -O2 -lcap -I../../../include/uapi -I../../../lib
 
 test_objs = test_verifier test_tag test_maps test_lru_map test_lpm_map
 
@@ -7,6 +7,8 @@ TEST_FILES := $(test_objs)
 
 all: $(test_objs)
 
+$(test_objs): ../../../lib/bpf/bpf.o
+
 include ../lib.mk
 
 clean: