diff options
Diffstat (limited to 'samples/bpf/fds_example.c')
| -rw-r--r-- | samples/bpf/fds_example.c | 195 |
1 files changed, 195 insertions, 0 deletions
diff --git a/samples/bpf/fds_example.c b/samples/bpf/fds_example.c new file mode 100644 index 0000000000..88a26f3ce2 --- /dev/null +++ b/samples/bpf/fds_example.c @@ -0,0 +1,195 @@ +#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/libbpf.h> +#include "bpf_insn.h" +#include "sock_example.h" +#include "bpf_util.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 + +char bpf_log_buf[BPF_LOG_BUF_SIZE]; + +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_prog_create(const char *object) +{ + static struct bpf_insn insns[] = { + BPF_MOV64_IMM(BPF_REG_0, 1), + BPF_EXIT_INSN(), + }; + size_t insns_cnt = ARRAY_SIZE(insns); + struct bpf_object *obj; + int err; + + if (object) { + obj = bpf_object__open_file(object, NULL); + assert(!libbpf_get_error(obj)); + err = bpf_object__load(obj); + assert(!err); + return bpf_program__fd(bpf_object__next_program(obj, NULL)); + } else { + LIBBPF_OPTS(bpf_prog_load_opts, opts, + .log_buf = bpf_log_buf, + .log_size = BPF_LOG_BUF_SIZE, + ); + + return bpf_prog_load(BPF_PROG_TYPE_SOCKET_FILTER, NULL, "GPL", + insns, insns_cnt, &opts); + } +} + +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(BPF_MAP_TYPE_ARRAY, NULL, sizeof(uint32_t), + sizeof(uint32_t), 1024, NULL); + 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; +} |