Commit cced0699 authored by Toke Høiland-Jørgensen's avatar Toke Høiland-Jørgensen Committed by Alexei Starovoitov
Browse files

samples/bpf: Remove the xdp_sample_pkts utility 



The functionality of this utility is covered by the xdpdump utility in
xdp-tools.

There's a slight difference in usage as the xdpdump utility's main focus is
to dump packets before or after they are processed by an existing XDP
program. However, xdpdump also has the --load-xdp-program switch, which
will make it attach its own program if no existing program is loaded. With
this, xdp_sample_pkts usage can be converted as:

xdp_sample_pkts eth0
  --> xdpdump --load-xdp-program eth0

To get roughly equivalent behaviour.

Signed-off-by: default avatarToke Høiland-Jørgensen <toke@redhat.com>
Link: https://lore.kernel.org/r/20230824102255.1561885-6-toke@redhat.com


Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
parent eaca21d6

samples/bpf/Makefile

+0 −3
Original line number Diff line number Diff line
@@ -44,7 +44,6 @@ tprogs-y += cpustat 
tprogs-y += xdp_adjust_tail

tprogs-y += xdp_fwd

tprogs-y += task_fd_query

tprogs-y += xdp_sample_pkts

tprogs-y += ibumad

tprogs-y += hbm
@@ -95,7 +94,6 @@ cpustat-objs := cpustat_user.o 
xdp_adjust_tail-objs := xdp_adjust_tail_user.o

xdp_fwd-objs := xdp_fwd_user.o

task_fd_query-objs := task_fd_query_user.o $(TRACE_HELPERS)

xdp_sample_pkts-objs := xdp_sample_pkts_user.o

ibumad-objs := ibumad_user.o

hbm-objs := hbm.o $(CGROUP_HELPERS)
@@ -148,7 +146,6 @@ always-y += cpustat_kern.o 
always-y += xdp_adjust_tail_kern.o

always-y += xdp_fwd_kern.o

always-y += task_fd_query_kern.o

always-y += xdp_sample_pkts_kern.o

always-y += ibumad_kern.o

always-y += hbm_out_kern.o

always-y += hbm_edt_kern.o

samples/bpf/xdp_sample_pkts_kern.c

deleted100644 → 0
+0 −57
Original line number Diff line number Diff line 
// SPDX-License-Identifier: GPL-2.0

#include <linux/ptrace.h>

#include <linux/version.h>

#include <uapi/linux/bpf.h>

#include <bpf/bpf_helpers.h>



#define SAMPLE_SIZE 64ul



struct {

	__uint(type, BPF_MAP_TYPE_PERF_EVENT_ARRAY);

	__uint(key_size, sizeof(int));

	__uint(value_size, sizeof(u32));

} my_map SEC(".maps");



SEC("xdp_sample")

int xdp_sample_prog(struct xdp_md *ctx)

{

	void *data_end = (void *)(long)ctx->data_end;

	void *data = (void *)(long)ctx->data;



	/* Metadata will be in the perf event before the packet data. */

	struct S {

		u16 cookie;

		u16 pkt_len;

	} __packed metadata;



	if (data < data_end) {

		/* The XDP perf_event_output handler will use the upper 32 bits

		 * of the flags argument as a number of bytes to include of the

		 * packet payload in the event data. If the size is too big, the

		 * call to bpf_perf_event_output will fail and return -EFAULT.

		 *

		 * See bpf_xdp_event_output in net/core/filter.c.

		 *

		 * The BPF_F_CURRENT_CPU flag means that the event output fd

		 * will be indexed by the CPU number in the event map.

		 */

		u64 flags = BPF_F_CURRENT_CPU;

		u16 sample_size;

		int ret;



		metadata.cookie = 0xdead;

		metadata.pkt_len = (u16)(data_end - data);

		sample_size = min(metadata.pkt_len, SAMPLE_SIZE);

		flags |= (u64)sample_size << 32;



		ret = bpf_perf_event_output(ctx, &my_map, flags,

					    &metadata, sizeof(metadata));

		if (ret)

			bpf_printk("perf_event_output failed: %d\n", ret);

	}



	return XDP_PASS;

}



char _license[] SEC("license") = "GPL";

u32 _version SEC("version") = LINUX_VERSION_CODE;

samples/bpf/xdp_sample_pkts_user.c

deleted100644 → 0
+0 −196
Original line number Diff line number Diff line 
// 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_prog_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;

}