samples/bpf: Move open_raw_sock to separate header

This function was declared in libbpf.c and was the only remaining
function in this library, but has nothing to do with BPF. Shift it out
into a new header, sock_example.h, and include it from the relevant
samples.

Signed-off-by: Joe Stringer <joe@ovn.org>
Cc: Alexei Starovoitov <ast@fb.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/r/20161209024620.31660-8-joe@ovn.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

samples/bpf/Makefile

@@ -36,7 +36,7 @@ hostprogs-y += lwt_len_hist
 hostprogs-y += xdp_tx_iptunnel
 
 # Libbpf dependencies
-LIBBPF := libbpf.o ../../tools/lib/bpf/bpf.o
+LIBBPF := ../../tools/lib/bpf/bpf.o
 
 test_lru_dist-objs := test_lru_dist.o $(LIBBPF)
 sock_example-objs := sock_example.o $(LIBBPF)

samples/bpf/fds_example.c

@@ -14,6 +14,7 @@
 
 #include "bpf_load.h"
 #include "libbpf.h"
+#include "sock_example.h"
 
 #define BPF_F_PIN	(1 << 0)
 #define BPF_F_GET	(1 << 1)

samples/bpf/libbpf.h

@@ -185,7 +185,4 @@ struct bpf_insn;
 		.off   = 0,					\
 		.imm   = 0 })
 
-/* create RAW socket and bind to interface 'name' */
-int open_raw_sock(const char *name);
-
 #endif

samples/bpf/sock_example.c

@@ -27,6 +27,7 @@
 #include <linux/ip.h>
 #include <stddef.h>
 #include "libbpf.h"
+#include "sock_example.h"
 
 char bpf_log_buf[BPF_LOG_BUF_SIZE];
 

samples/bpf/sock_example.h

@@ -1,4 +1,3 @@
-/* eBPF mini library */
 #include <stdlib.h>
 #include <stdio.h>
 #include <linux/unistd.h>
@@ -11,7 +10,7 @@
 #include <arpa/inet.h>
 #include "libbpf.h"
 
-int open_raw_sock(const char *name)
+static inline int open_raw_sock(const char *name)
 {
 	struct sockaddr_ll sll;
 	int sock;

samples/bpf/sockex1_user.c

@@ -3,6 +3,7 @@
 #include <linux/bpf.h>
 #include "libbpf.h"
 #include "bpf_load.h"
+#include "sock_example.h"
 #include <unistd.h>
 #include <arpa/inet.h>
 

samples/bpf/sockex2_user.c

@@ -3,6 +3,7 @@
 #include <linux/bpf.h>
 #include "libbpf.h"
 #include "bpf_load.h"
+#include "sock_example.h"
 #include <unistd.h>
 #include <arpa/inet.h>
 #include <sys/resource.h>

samples/bpf/sockex3_user.c

@@ -3,6 +3,7 @@
 #include <linux/bpf.h>
 #include "libbpf.h"
 #include "bpf_load.h"
+#include "sock_example.h"
 #include <unistd.h>
 #include <arpa/inet.h>
 #include <sys/resource.h>