bpf: add initial suite for selftests

Add a start of a test suite for kernel selftests. This moves test_verifier
and test_maps over to tools/testing/selftests/bpf/ along with various
code improvements and also adds a script for invoking test_bpf module.
The test suite can simply be run via selftest framework, f.e.:

  # cd tools/testing/selftests/bpf/
  # make
  # make run_tests

Both test_verifier and test_maps were kind of misplaced in samples/bpf/
directory and we were looking into adding them to selftests for a while
now, so it can be picked up by kbuild bot et al and hopefully also get
more exposure and thus new test case additions.

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 108 insertions, 0 deletions

diff --git a/tools/testing/selftests/bpf/bpf_sys.h b/tools/testing/selftests/bpf/bpf_sys.h
new file mode 100644
index 000000000000..6b4565f2a3f2
--- /dev/null
+++ b/tools/testing/selftests/bpf/bpf_sys.h
@@ -0,0 +1,108 @@
+#ifndef __BPF_SYS__
+#define __BPF_SYS__
+
+#include <stdint.h>
+#include <stdlib.h>
+
+#include <sys/syscall.h>
+
+#include <linux/bpf.h>
+
+static inline __u64 bpf_ptr_to_u64(const void *ptr)
+{
+	return (__u64)(unsigned long) ptr;
+}
+
+static inline int bpf(int 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
+}
+
+static inline int bpf_map_lookup(int fd, const void *key, void *value)
+{
+	union bpf_attr attr = {};
+
+	attr.map_fd = fd;
+	attr.key = bpf_ptr_to_u64(key);
+	attr.value = bpf_ptr_to_u64(value);
+
+	return bpf(BPF_MAP_LOOKUP_ELEM, &attr, sizeof(attr));
+}
+
+static inline int bpf_map_update(int fd, const void *key, const void *value,
+				 uint64_t flags)
+{
+	union bpf_attr attr = {};
+
+	attr.map_fd = fd;
+	attr.key = bpf_ptr_to_u64(key);
+	attr.value = bpf_ptr_to_u64(value);
+	attr.flags = flags;
+
+	return bpf(BPF_MAP_UPDATE_ELEM, &attr, sizeof(attr));
+}
+
+static inline int bpf_map_delete(int fd, const void *key)
+{
+	union bpf_attr attr = {};
+
+	attr.map_fd = fd;
+	attr.key = bpf_ptr_to_u64(key);
+
+	return bpf(BPF_MAP_DELETE_ELEM, &attr, sizeof(attr));
+}
+
+static inline int bpf_map_next_key(int fd, const void *key, void *next_key)
+{
+	union bpf_attr attr = {};
+
+	attr.map_fd = fd;
+	attr.key = bpf_ptr_to_u64(key);
+	attr.next_key = bpf_ptr_to_u64(next_key);
+
+	return bpf(BPF_MAP_GET_NEXT_KEY, &attr, sizeof(attr));
+}
+
+static inline int bpf_map_create(enum bpf_map_type type, uint32_t size_key,
+				 uint32_t size_value, uint32_t max_elem,
+				 uint32_t flags)
+{
+	union bpf_attr attr = {};
+
+	attr.map_type = type;
+	attr.key_size = size_key;
+	attr.value_size = size_value;
+	attr.max_entries = max_elem;
+	attr.map_flags = flags;
+
+	return bpf(BPF_MAP_CREATE, &attr, sizeof(attr));
+}
+
+static inline int bpf_prog_load(enum bpf_prog_type type,
+				const struct bpf_insn *insns, size_t size_insns,
+				const char *license, char *log, size_t size_log)
+{
+	union bpf_attr attr = {};
+
+	attr.prog_type = type;
+	attr.insns = bpf_ptr_to_u64(insns);
+	attr.insn_cnt = size_insns / sizeof(struct bpf_insn);
+	attr.license = bpf_ptr_to_u64(license);
+
+	if (size_log > 0) {
+		attr.log_buf = bpf_ptr_to_u64(log);
+		attr.log_size = size_log;
+		attr.log_level = 1;
+		log[0] = 0;
+	}
+
+	return bpf(BPF_PROG_LOAD, &attr, sizeof(attr));
+}
+
+#endif /* __BPF_SYS__ */