tools lib bpf: Add bpf_prog_{attach,detach}

Commit d8c5b17 ("samples: bpf: add userspace example for attaching eBPF programs to cgroups") added these functions to samples/libbpf, but during this merge all of the samples libbpf functionality is shifting to tools/lib/bpf. Shift these functions there. Committer notes: Use bzero + attr.FIELD = value instead of 'attr = { .FIELD = value, just like the other wrapper calls to sys_bpf with bpf_attr to make this build in older toolchais, such as the ones in CentOS 5 and 6. Signed-off-by: Joe Stringer <[email protected]> Cc: Alexei Starovoitov <[email protected]> Cc: Daniel Borkmann <[email protected]> Cc: Wang Nan <[email protected]> Link: http://lkml.kernel.org/n/[email protected] Link: https://github.com/joestringer/linux/commit/353e6f298c3d0a92fa8bfa61ff898c5050261a12.patch Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
ambv · Dec 20, 2016 · 5dc880d · 5dc880d
1 parent 43371c8
commit 5dc880d
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Showing 4 changed files with 26 additions and 24 deletions.
diff --git a/samples/bpf/libbpf.c b/samples/bpf/libbpf.c
@@ -11,27 +11,6 @@
 #include <arpa/inet.h>
 #include "libbpf.h"
 
-int bpf_prog_attach(int prog_fd, int target_fd, enum bpf_attach_type type)
-{
-	union bpf_attr attr = {
-		.target_fd = target_fd,
-		.attach_bpf_fd = prog_fd,
-		.attach_type = type,
-	};
-
-	return syscall(__NR_bpf, BPF_PROG_ATTACH, &attr, sizeof(attr));
-}
-
-int bpf_prog_detach(int target_fd, enum bpf_attach_type type)
-{
-	union bpf_attr attr = {
-		.target_fd = target_fd,
-		.attach_type = type,
-	};
-
-	return syscall(__NR_bpf, BPF_PROG_DETACH, &attr, sizeof(attr));
-}
-
 int open_raw_sock(const char *name)
 {
 	struct sockaddr_ll sll;

diff --git a/samples/bpf/libbpf.h b/samples/bpf/libbpf.h
@@ -6,9 +6,6 @@
 
 struct bpf_insn;
 
-int bpf_prog_attach(int prog_fd, int attachable_fd, enum bpf_attach_type type);
-int bpf_prog_detach(int attachable_fd, enum bpf_attach_type type);
-
 /* ALU ops on registers, bpf_add|sub|...: dst_reg += src_reg */
 
 #define BPF_ALU64_REG(OP, DST, SRC)				\

diff --git a/tools/lib/bpf/bpf.c b/tools/lib/bpf/bpf.c
@@ -167,3 +167,26 @@ int bpf_obj_get(const char *pathname)
 
 	return sys_bpf(BPF_OBJ_GET, &attr, sizeof(attr));
 }
+
+int bpf_prog_attach(int prog_fd, int target_fd, enum bpf_attach_type type)
+{
+	union bpf_attr attr;
+
+	bzero(&attr, sizeof(attr));
+	attr.target_fd	   = target_fd;
+	attr.attach_bpf_fd = prog_fd;
+	attr.attach_type   = type;
+
+	return sys_bpf(BPF_PROG_ATTACH, &attr, sizeof(attr));
+}
+
+int bpf_prog_detach(int target_fd, enum bpf_attach_type type)
+{
+	union bpf_attr attr;
+
+	bzero(&attr, sizeof(attr));
+	attr.target_fd	 = target_fd;
+	attr.attach_type = type;
+
+	return sys_bpf(BPF_PROG_DETACH, &attr, sizeof(attr));
+}
diff --git a/tools/lib/bpf/bpf.h b/tools/lib/bpf/bpf.h
@@ -41,5 +41,8 @@ int bpf_map_delete_elem(int fd, void *key);
 int bpf_map_get_next_key(int fd, 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);
+int bpf_prog_detach(int attachable_fd, enum bpf_attach_type type);
+
 
 #endif