v4.19.13 snapshot.
diff --git a/samples/bpf/fds_example.c b/samples/bpf/fds_example.c
new file mode 100644
index 0000000..9854854
--- /dev/null
+++ b/samples/bpf/fds_example.c
@@ -0,0 +1,188 @@
+#include <linux/unistd.h>
+#include <linux/bpf.h>
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdint.h>
+#include <unistd.h>
+#include <string.h>
+#include <assert.h>
+#include <errno.h>
+
+#include <sys/types.h>
+#include <sys/socket.h>
+
+#include <bpf/bpf.h>
+
+#include "bpf_insn.h"
+#include "bpf_load.h"
+#include "sock_example.h"
+
+#define BPF_F_PIN (1 << 0)
+#define BPF_F_GET (1 << 1)
+#define BPF_F_PIN_GET (BPF_F_PIN | BPF_F_GET)
+
+#define BPF_F_KEY (1 << 2)
+#define BPF_F_VAL (1 << 3)
+#define BPF_F_KEY_VAL (BPF_F_KEY | BPF_F_VAL)
+
+#define BPF_M_UNSPEC 0
+#define BPF_M_MAP 1
+#define BPF_M_PROG 2
+
+static void usage(void)
+{
+ printf("Usage: fds_example [...]\n");
+ printf(" -F <file> File to pin/get object\n");
+ printf(" -P |- pin object\n");
+ printf(" -G `- get object\n");
+ printf(" -m eBPF map mode\n");
+ printf(" -k <key> |- map key\n");
+ printf(" -v <value> `- map value\n");
+ printf(" -p eBPF prog mode\n");
+ printf(" -o <object> `- object file\n");
+ printf(" -h Display this help.\n");
+}
+
+static int bpf_map_create(void)
+{
+ return bpf_create_map(BPF_MAP_TYPE_ARRAY, sizeof(uint32_t),
+ sizeof(uint32_t), 1024, 0);
+}
+
+static int bpf_prog_create(const char *object)
+{
+ static struct bpf_insn insns[] = {
+ BPF_MOV64_IMM(BPF_REG_0, 1),
+ BPF_EXIT_INSN(),
+ };
+ size_t insns_cnt = sizeof(insns) / sizeof(struct bpf_insn);
+
+ if (object) {
+ assert(!load_bpf_file((char *)object));
+ return prog_fd[0];
+ } else {
+ return bpf_load_program(BPF_PROG_TYPE_SOCKET_FILTER,
+ insns, insns_cnt, "GPL", 0,
+ bpf_log_buf, BPF_LOG_BUF_SIZE);
+ }
+}
+
+static int bpf_do_map(const char *file, uint32_t flags, uint32_t key,
+ uint32_t value)
+{
+ int fd, ret;
+
+ if (flags & BPF_F_PIN) {
+ fd = bpf_map_create();
+ printf("bpf: map fd:%d (%s)\n", fd, strerror(errno));
+ assert(fd > 0);
+
+ ret = bpf_obj_pin(fd, file);
+ printf("bpf: pin ret:(%d,%s)\n", ret, strerror(errno));
+ assert(ret == 0);
+ } else {
+ fd = bpf_obj_get(file);
+ printf("bpf: get fd:%d (%s)\n", fd, strerror(errno));
+ assert(fd > 0);
+ }
+
+ if ((flags & BPF_F_KEY_VAL) == BPF_F_KEY_VAL) {
+ ret = bpf_map_update_elem(fd, &key, &value, 0);
+ printf("bpf: fd:%d u->(%u:%u) ret:(%d,%s)\n", fd, key, value,
+ ret, strerror(errno));
+ assert(ret == 0);
+ } else if (flags & BPF_F_KEY) {
+ ret = bpf_map_lookup_elem(fd, &key, &value);
+ printf("bpf: fd:%d l->(%u):%u ret:(%d,%s)\n", fd, key, value,
+ ret, strerror(errno));
+ assert(ret == 0);
+ }
+
+ return 0;
+}
+
+static int bpf_do_prog(const char *file, uint32_t flags, const char *object)
+{
+ int fd, sock, ret;
+
+ if (flags & BPF_F_PIN) {
+ fd = bpf_prog_create(object);
+ printf("bpf: prog fd:%d (%s)\n", fd, strerror(errno));
+ assert(fd > 0);
+
+ ret = bpf_obj_pin(fd, file);
+ printf("bpf: pin ret:(%d,%s)\n", ret, strerror(errno));
+ assert(ret == 0);
+ } else {
+ fd = bpf_obj_get(file);
+ printf("bpf: get fd:%d (%s)\n", fd, strerror(errno));
+ assert(fd > 0);
+ }
+
+ sock = open_raw_sock("lo");
+ assert(sock > 0);
+
+ ret = setsockopt(sock, SOL_SOCKET, SO_ATTACH_BPF, &fd, sizeof(fd));
+ printf("bpf: sock:%d <- fd:%d attached ret:(%d,%s)\n", sock, fd,
+ ret, strerror(errno));
+ assert(ret == 0);
+
+ return 0;
+}
+
+int main(int argc, char **argv)
+{
+ const char *file = NULL, *object = NULL;
+ uint32_t key = 0, value = 0, flags = 0;
+ int opt, mode = BPF_M_UNSPEC;
+
+ while ((opt = getopt(argc, argv, "F:PGmk:v:po:")) != -1) {
+ switch (opt) {
+ /* General args */
+ case 'F':
+ file = optarg;
+ break;
+ case 'P':
+ flags |= BPF_F_PIN;
+ break;
+ case 'G':
+ flags |= BPF_F_GET;
+ break;
+ /* Map-related args */
+ case 'm':
+ mode = BPF_M_MAP;
+ break;
+ case 'k':
+ key = strtoul(optarg, NULL, 0);
+ flags |= BPF_F_KEY;
+ break;
+ case 'v':
+ value = strtoul(optarg, NULL, 0);
+ flags |= BPF_F_VAL;
+ break;
+ /* Prog-related args */
+ case 'p':
+ mode = BPF_M_PROG;
+ break;
+ case 'o':
+ object = optarg;
+ break;
+ default:
+ goto out;
+ }
+ }
+
+ if (!(flags & BPF_F_PIN_GET) || !file)
+ goto out;
+
+ switch (mode) {
+ case BPF_M_MAP:
+ return bpf_do_map(file, flags, key, value);
+ case BPF_M_PROG:
+ return bpf_do_prog(file, flags, object);
+ }
+out:
+ usage();
+ return -1;
+}