samples: bpf: use libbpf where easy

Some samples don't really need the magic of bpf_load,
switch them to libbpf.

v2: - specify program types.

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

samples/bpf/Makefile

@@ -59,9 +59,9 @@ LIBBPF = $(TOOLS_PATH)/lib/bpf/libbpf.a
 CGROUP_HELPERS := ../../tools/testing/selftests/bpf/cgroup_helpers.o
 TRACE_HELPERS := ../../tools/testing/selftests/bpf/trace_helpers.o
 
-fds_example-objs := bpf_load.o fds_example.o
-sockex1-objs := bpf_load.o sockex1_user.o
-sockex2-objs := bpf_load.o sockex2_user.o
+fds_example-objs := fds_example.o
+sockex1-objs := sockex1_user.o
+sockex2-objs := sockex2_user.o
 sockex3-objs := bpf_load.o sockex3_user.o
 tracex1-objs := bpf_load.o tracex1_user.o
 tracex2-objs := bpf_load.o tracex2_user.o

samples/bpf/fds_example.c

@@ -14,8 +14,8 @@
 
 #include <bpf/bpf.h>
 
+#include "bpf/libbpf.h"
 #include "bpf_insn.h"
-#include "bpf_load.h"
 #include "sock_example.h"
 
 #define BPF_F_PIN	(1 << 0)
@@ -57,10 +57,14 @@ static int bpf_prog_create(const char *object)
 		BPF_EXIT_INSN(),
 	};
 	size_t insns_cnt = sizeof(insns) / sizeof(struct bpf_insn);
+	char bpf_log_buf[BPF_LOG_BUF_SIZE];
+	struct bpf_object *obj;
+	int prog_fd;
 
 	if (object) {
-		assert(!load_bpf_file((char *)object));
-		return prog_fd[0];
+		assert(!bpf_prog_load(object, BPF_PROG_TYPE_UNSPEC,
+				      &obj, &prog_fd));
+		return prog_fd;
 	} else {
 		return bpf_load_program(BPF_PROG_TYPE_SOCKET_FILTER,
 					insns, insns_cnt, "GPL", 0,

samples/bpf/sockex1_user.c

@@ -3,28 +3,31 @@
 #include <assert.h>
 #include <linux/bpf.h>
 #include <bpf/bpf.h>
-#include "bpf_load.h"
+#include "bpf/libbpf.h"
 #include "sock_example.h"
 #include <unistd.h>
 #include <arpa/inet.h>
 
 int main(int ac, char **argv)
 {
+	struct bpf_object *obj;
+	int map_fd, prog_fd;
 	char filename[256];
-	FILE *f;
 	int i, sock;
+	FILE *f;
 
 	snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
 
-	if (load_bpf_file(filename)) {
-		printf("%s", bpf_log_buf);
+	if (bpf_prog_load(filename, BPF_PROG_TYPE_SOCKET_FILTER,
+			  &obj, &prog_fd))
 		return 1;
-	}
+
+	map_fd = bpf_object__find_map_fd_by_name(obj, "my_map");
 
 	sock = open_raw_sock("lo");
 
-	assert(setsockopt(sock, SOL_SOCKET, SO_ATTACH_BPF, prog_fd,
-			  sizeof(prog_fd[0])) == 0);
+	assert(setsockopt(sock, SOL_SOCKET, SO_ATTACH_BPF, &prog_fd,
+			  sizeof(prog_fd)) == 0);
 
 	f = popen("ping -4 -c5 localhost", "r");
 	(void) f;
@@ -34,13 +37,13 @@ int main(int ac, char **argv)
 		int key;
 
 		key = IPPROTO_TCP;
-		assert(bpf_map_lookup_elem(map_fd[0], &key, &tcp_cnt) == 0);
+		assert(bpf_map_lookup_elem(map_fd, &key, &tcp_cnt) == 0);
 
 		key = IPPROTO_UDP;
-		assert(bpf_map_lookup_elem(map_fd[0], &key, &udp_cnt) == 0);
+		assert(bpf_map_lookup_elem(map_fd, &key, &udp_cnt) == 0);
 
 		key = IPPROTO_ICMP;
-		assert(bpf_map_lookup_elem(map_fd[0], &key, &icmp_cnt) == 0);
+		assert(bpf_map_lookup_elem(map_fd, &key, &icmp_cnt) == 0);
 
 		printf("TCP %lld UDP %lld ICMP %lld bytes\n",
 		       tcp_cnt, udp_cnt, icmp_cnt);

samples/bpf/sockex2_user.c

@@ -3,7 +3,7 @@
 #include <assert.h>
 #include <linux/bpf.h>
 #include <bpf/bpf.h>
-#include "bpf_load.h"
+#include "bpf/libbpf.h"
 #include "sock_example.h"
 #include <unistd.h>
 #include <arpa/inet.h>
@@ -17,22 +17,25 @@ struct pair {
 int main(int ac, char **argv)
 {
 	struct rlimit r = {RLIM_INFINITY, RLIM_INFINITY};
+	struct bpf_object *obj;
+	int map_fd, prog_fd;
 	char filename[256];
-	FILE *f;
 	int i, sock;
+	FILE *f;
 
 	snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
 	setrlimit(RLIMIT_MEMLOCK, &r);
 
-	if (load_bpf_file(filename)) {
-		printf("%s", bpf_log_buf);
+	if (bpf_prog_load(filename, BPF_PROG_TYPE_SOCKET_FILTER,
+			  &obj, &prog_fd))
 		return 1;
-	}
+
+	map_fd = bpf_object__find_map_fd_by_name(obj, "hash_map");
 
 	sock = open_raw_sock("lo");
 
-	assert(setsockopt(sock, SOL_SOCKET, SO_ATTACH_BPF, prog_fd,
-			  sizeof(prog_fd[0])) == 0);
+	assert(setsockopt(sock, SOL_SOCKET, SO_ATTACH_BPF, &prog_fd,
+			  sizeof(prog_fd)) == 0);
 
 	f = popen("ping -4 -c5 localhost", "r");
 	(void) f;
@@ -41,8 +44,8 @@ int main(int ac, char **argv)
 		int key = 0, next_key;
 		struct pair value;
 
-		while (bpf_map_get_next_key(map_fd[0], &key, &next_key) == 0) {
-			bpf_map_lookup_elem(map_fd[0], &next_key, &value);
+		while (bpf_map_get_next_key(map_fd, &key, &next_key) == 0) {
+			bpf_map_lookup_elem(map_fd, &next_key, &value);
 			printf("ip %s bytes %lld packets %lld\n",
 			       inet_ntoa((struct in_addr){htonl(next_key)}),
 			       value.bytes, value.packets);