1 files changed, 183 insertions, 0 deletions

diff --git a/samples/bpf/fds_example.c b/samples/bpf/fds_example.c
new file mode 100644
index 000000000000..e2fd16c3d0f0
--- /dev/null
+++ b/samples/bpf/fds_example.c
@@ -0,0 +1,183 @@
+#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_load.h"
+#include "libbpf.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);
+}
+
+static int bpf_prog_create(const char *object)
+{
+        static const struct bpf_insn insns[] = {
+                BPF_MOV64_IMM(BPF_REG_0, 1),
+                BPF_EXIT_INSN(),
+        };
+
+        if (object) {
+                assert(!load_bpf_file((char *)object));
+                return prog_fd[0];
+        } else {
+                return bpf_prog_load(BPF_PROG_TYPE_SOCKET_FILTER,
+                                     insns, sizeof(insns), "GPL", 0);
+        }
+}
+
+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_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_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;
+}