diff options
Diffstat (limited to 'samples/bpf/xdp_sample_pkts_user.c')
| -rw-r--r-- | samples/bpf/xdp_sample_pkts_user.c | 196 |
1 files changed, 196 insertions, 0 deletions
diff --git a/samples/bpf/xdp_sample_pkts_user.c b/samples/bpf/xdp_sample_pkts_user.c new file mode 100644 index 000000000..7df716323 --- /dev/null +++ b/samples/bpf/xdp_sample_pkts_user.c @@ -0,0 +1,196 @@ +// SPDX-License-Identifier: GPL-2.0 +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <linux/perf_event.h> +#include <linux/bpf.h> +#include <net/if.h> +#include <errno.h> +#include <assert.h> +#include <sys/sysinfo.h> +#include <sys/ioctl.h> +#include <signal.h> +#include <bpf/libbpf.h> +#include <bpf/bpf.h> +#include <libgen.h> +#include <linux/if_link.h> + +#include "perf-sys.h" + +static int if_idx; +static char *if_name; +static __u32 xdp_flags = XDP_FLAGS_UPDATE_IF_NOEXIST; +static __u32 prog_id; +static struct perf_buffer *pb = NULL; + +static int do_attach(int idx, int fd, const char *name) +{ + struct bpf_prog_info info = {}; + __u32 info_len = sizeof(info); + int err; + + err = bpf_xdp_attach(idx, fd, xdp_flags, NULL); + if (err < 0) { + printf("ERROR: failed to attach program to %s\n", name); + return err; + } + + err = bpf_obj_get_info_by_fd(fd, &info, &info_len); + if (err) { + printf("can't get prog info - %s\n", strerror(errno)); + return err; + } + prog_id = info.id; + + return err; +} + +static int do_detach(int idx, const char *name) +{ + __u32 curr_prog_id = 0; + int err = 0; + + err = bpf_xdp_query_id(idx, xdp_flags, &curr_prog_id); + if (err) { + printf("bpf_xdp_query_id failed\n"); + return err; + } + if (prog_id == curr_prog_id) { + err = bpf_xdp_detach(idx, xdp_flags, NULL); + if (err < 0) + printf("ERROR: failed to detach prog from %s\n", name); + } else if (!curr_prog_id) { + printf("couldn't find a prog id on a %s\n", name); + } else { + printf("program on interface changed, not removing\n"); + } + + return err; +} + +#define SAMPLE_SIZE 64 + +static void print_bpf_output(void *ctx, int cpu, void *data, __u32 size) +{ + struct { + __u16 cookie; + __u16 pkt_len; + __u8 pkt_data[SAMPLE_SIZE]; + } __packed *e = data; + int i; + + if (e->cookie != 0xdead) { + printf("BUG cookie %x sized %d\n", e->cookie, size); + return; + } + + printf("Pkt len: %-5d bytes. Ethernet hdr: ", e->pkt_len); + for (i = 0; i < 14 && i < e->pkt_len; i++) + printf("%02x ", e->pkt_data[i]); + printf("\n"); +} + +static void sig_handler(int signo) +{ + do_detach(if_idx, if_name); + perf_buffer__free(pb); + exit(0); +} + +static void usage(const char *prog) +{ + fprintf(stderr, + "%s: %s [OPTS] <ifname|ifindex>\n\n" + "OPTS:\n" + " -F force loading prog\n" + " -S use skb-mode\n", + __func__, prog); +} + +int main(int argc, char **argv) +{ + const char *optstr = "FS"; + int prog_fd, map_fd, opt; + struct bpf_program *prog; + struct bpf_object *obj; + struct bpf_map *map; + char filename[256]; + int ret, err; + + while ((opt = getopt(argc, argv, optstr)) != -1) { + switch (opt) { + case 'F': + xdp_flags &= ~XDP_FLAGS_UPDATE_IF_NOEXIST; + break; + case 'S': + xdp_flags |= XDP_FLAGS_SKB_MODE; + break; + default: + usage(basename(argv[0])); + return 1; + } + } + + if (!(xdp_flags & XDP_FLAGS_SKB_MODE)) + xdp_flags |= XDP_FLAGS_DRV_MODE; + + if (optind == argc) { + usage(basename(argv[0])); + return 1; + } + + snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]); + + obj = bpf_object__open_file(filename, NULL); + if (libbpf_get_error(obj)) + return 1; + + prog = bpf_object__next_program(obj, NULL); + bpf_program__set_type(prog, BPF_PROG_TYPE_XDP); + + err = bpf_object__load(obj); + if (err) + return 1; + + prog_fd = bpf_program__fd(prog); + + map = bpf_object__next_map(obj, NULL); + if (!map) { + printf("finding a map in obj file failed\n"); + return 1; + } + map_fd = bpf_map__fd(map); + + if_idx = if_nametoindex(argv[optind]); + if (!if_idx) + if_idx = strtoul(argv[optind], NULL, 0); + + if (!if_idx) { + fprintf(stderr, "Invalid ifname\n"); + return 1; + } + if_name = argv[optind]; + err = do_attach(if_idx, prog_fd, if_name); + if (err) + return err; + + if (signal(SIGINT, sig_handler) || + signal(SIGHUP, sig_handler) || + signal(SIGTERM, sig_handler)) { + perror("signal"); + return 1; + } + + pb = perf_buffer__new(map_fd, 8, print_bpf_output, NULL, NULL, NULL); + err = libbpf_get_error(pb); + if (err) { + perror("perf_buffer setup failed"); + return 1; + } + + while ((ret = perf_buffer__poll(pb, 1000)) >= 0) { + } + + kill(0, SIGINT); + return ret; +} |