bpf: Add bpf_verify_program() to the library.

This allows a test case to load a BPF program and unconditionally
acquire the verifier log.

It also allows specification of the strict alignment flag.

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

2 files changed, 26 insertions, 0 deletions

diff --git a/tools/lib/bpf/bpf.c b/tools/lib/bpf/bpf.c
index 4fe444b8092e..6e178987af8e 100644
--- a/tools/lib/bpf/bpf.c
+++ b/tools/lib/bpf/bpf.c
@@ -117,6 +117,28 @@ int bpf_load_program(enum bpf_prog_type type, const struct bpf_insn *insns,
         return sys_bpf(BPF_PROG_LOAD, &attr, sizeof(attr));
 }
 
+int bpf_verify_program(enum bpf_prog_type type, const struct bpf_insn *insns,
+                       size_t insns_cnt, int strict_alignment,
+                       const char *license, __u32 kern_version,
+                       char *log_buf, size_t log_buf_sz)
+{
+        union bpf_attr attr;
+
+        bzero(&attr, sizeof(attr));
+        attr.prog_type = type;
+        attr.insn_cnt = (__u32)insns_cnt;
+        attr.insns = ptr_to_u64(insns);
+        attr.license = ptr_to_u64(license);
+        attr.log_buf = ptr_to_u64(log_buf);
+        attr.log_size = log_buf_sz;
+        attr.log_level = 2;
+        log_buf[0] = 0;
+        attr.kern_version = kern_version;
+        attr.prog_flags = strict_alignment ? BPF_F_STRICT_ALIGNMENT : 0;
+
+        return sys_bpf(BPF_PROG_LOAD, &attr, sizeof(attr));
+}
+
 int bpf_map_update_elem(int fd, const void *key, const void *value,
                         __u64 flags)
 {
diff --git a/tools/lib/bpf/bpf.h b/tools/lib/bpf/bpf.h
index edb4daeff7a5..972bd8333eb7 100644
--- a/tools/lib/bpf/bpf.h
+++ b/tools/lib/bpf/bpf.h
@@ -35,6 +35,10 @@ 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_verify_program(enum bpf_prog_type type, const struct bpf_insn *insns,
+                       size_t insns_cnt, int strict_alignment,
+                       const char *license, __u32 kern_version,
+                       char *log_buf, size_t log_buf_sz);
 
 int bpf_map_update_elem(int fd, const void *key, const void *value,
                         __u64 flags);