[RFC PATCH v6 17/32] bpf tools: Introduce bpf_load_program() to bpf.c

Wang Nan
2015-06-09T05:56:56Z

bpf_load_program() can be used to load bpf program into kernel. To make
loading faster, first try to load without logbuf. Try again with logbuf
if the first try failed.

Signed-off-by: Wang Nan <wangnan0@huawei.com>
Acked-by: Alexei Starovoitov <ast@plumgrid.com>
---
tools/lib/bpf/bpf.c | 34 ++++++++++++++++++++++++++++++++++
tools/lib/bpf/bpf.h | 7 +++++++
2 files changed, 41 insertions(+)

diff --git a/tools/lib/bpf/bpf.c b/tools/lib/bpf/bpf.c
index e424418..6f7f883 100644
--- a/tools/lib/bpf/bpf.c
+++ b/tools/lib/bpf/bpf.c
@@ -29,6 +29,11 @@
# endif
#endif

+static __u64 ptr_to_u64(void *ptr)
+{
+ return (__u64) (unsigned long) ptr;
+}
+
static int sys_bpf(enum bpf_cmd cmd, union bpf_attr *attr,
unsigned int size)
{
@@ -48,3 +53,32 @@ 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,
+ u32 kern_version, char *log_buf, size_t log_buf_sz)
+{
+ int fd;
+ 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(NULL);
+ attr.log_size = 0;
+ attr.log_level = 0;
+ attr.kern_version = kern_version;
+
+ fd = sys_bpf(BPF_PROG_LOAD, &attr, sizeof(attr));
+ if (fd >= 0 || !log_buf || !log_buf_sz)
+ return fd;
+
+ /* Try again with log */
+ attr.log_buf = ptr_to_u64(log_buf);
+ attr.log_size = log_buf_sz;
+ attr.log_level = 1;
+ log_buf[0] = 0;
+ return sys_bpf(BPF_PROG_LOAD, &attr, sizeof(attr));
+}
diff --git a/tools/lib/bpf/bpf.h b/tools/lib/bpf/bpf.h
index 28f7942..854b736 100644
--- a/tools/lib/bpf/bpf.h
+++ b/tools/lib/bpf/bpf.h
@@ -13,4 +13,11 @@
int bpf_create_map(enum bpf_map_type map_type, int key_size, int value_size,
int max_entries);

+/* 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,
+ u32 kern_version, char *log_buf,
+ size_t log_buf_sz);
+
#endif
--
1.8.3.4