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Commit be5bca44 authored by Jakub Kicinski's avatar Jakub Kicinski Committed by Daniel Borkmann
Browse files

samples: bpf: convert some XDP samples from bpf_load to libbpf 



Now that we can use full powers of libbpf in BPF samples, we
should perhaps make the simplest XDP programs not depend on
bpf_load helpers.  This way newcomers will be exposed to the
recommended library from the start.

Use of bpf_prog_load_xattr() will also make it trivial to later
on request offload of the programs by simply adding ifindex to
the xattr.

Signed-off-by: default avatarJakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: default avatarQuentin Monnet <quentin.monnet@netronome.com>
Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
parent 17387dd5

samples/bpf/Makefile

+4 −4
Original line number Diff line number Diff line
@@ -79,9 +79,9 @@ test_cgrp2_attach-objs := test_cgrp2_attach.o $(LIBBPF) 
test_cgrp2_attach2-objs := test_cgrp2_attach2.o $(LIBBPF) $(CGROUP_HELPERS)

test_cgrp2_sock-objs := test_cgrp2_sock.o $(LIBBPF)

test_cgrp2_sock2-objs := bpf_load.o $(LIBBPF) test_cgrp2_sock2.o

xdp1-objs := bpf_load.o $(LIBBPF) xdp1_user.o

xdp1-objs := xdp1_user.o $(LIBBPF)

# reuse xdp1 source intentionally

xdp2-objs := bpf_load.o $(LIBBPF) xdp1_user.o

xdp2-objs := xdp1_user.o $(LIBBPF)

xdp_router_ipv4-objs := bpf_load.o $(LIBBPF) xdp_router_ipv4_user.o

test_current_task_under_cgroup-objs := bpf_load.o $(LIBBPF) $(CGROUP_HELPERS) \

				       test_current_task_under_cgroup_user.o
@@ -96,10 +96,10 @@ xdp_redirect-objs := bpf_load.o $(LIBBPF) xdp_redirect_user.o 
xdp_redirect_map-objs := bpf_load.o $(LIBBPF) xdp_redirect_map_user.o

xdp_redirect_cpu-objs := bpf_load.o $(LIBBPF) xdp_redirect_cpu_user.o

xdp_monitor-objs := bpf_load.o $(LIBBPF) xdp_monitor_user.o

xdp_rxq_info-objs := bpf_load.o $(LIBBPF) xdp_rxq_info_user.o

xdp_rxq_info-objs := xdp_rxq_info_user.o $(LIBBPF)

syscall_tp-objs := bpf_load.o $(LIBBPF) syscall_tp_user.o

cpustat-objs := bpf_load.o $(LIBBPF) cpustat_user.o

xdp_adjust_tail-objs := bpf_load.o $(LIBBPF) xdp_adjust_tail_user.o

xdp_adjust_tail-objs := xdp_adjust_tail_user.o $(LIBBPF)

xdpsock-objs := bpf_load.o $(LIBBPF) xdpsock_user.o

xdp_fwd-objs := bpf_load.o $(LIBBPF) xdp_fwd_user.o

samples/bpf/xdp1_user.c

+21 −10
Original line number Diff line number Diff line
@@ -16,9 +16,9 @@ 
#include <libgen.h>

#include <sys/resource.h>



#include "bpf_load.h"

#include "bpf_util.h"

#include "libbpf.h"

#include "bpf/bpf.h"

#include "bpf/libbpf.h"



static int ifindex;

static __u32 xdp_flags;
@@ -31,7 +31,7 @@ static void int_exit(int sig) 


/* simple per-protocol drop counter

 */

static void poll_stats(int interval)

static void poll_stats(int map_fd, int interval)

{

	unsigned int nr_cpus = bpf_num_possible_cpus();

	const unsigned int nr_keys = 256;
@@ -47,7 +47,7 @@ static void poll_stats(int interval) 
		for (key = 0; key < nr_keys; key++) {

			__u64 sum = 0;



			assert(bpf_map_lookup_elem(map_fd[0], &key, values) == 0);

			assert(bpf_map_lookup_elem(map_fd, &key, values) == 0);

			for (i = 0; i < nr_cpus; i++)

				sum += (values[i] - prev[key][i]);

			if (sum)
@@ -71,9 +71,14 @@ static void usage(const char *prog) 
int main(int argc, char **argv)

{

	struct rlimit r = {RLIM_INFINITY, RLIM_INFINITY};

	struct bpf_prog_load_attr prog_load_attr = {

		.prog_type	= BPF_PROG_TYPE_XDP,

	};

	const char *optstr = "SN";

	int prog_fd, map_fd, opt;

	struct bpf_object *obj;

	struct bpf_map *map;

	char filename[256];

	int opt;



	while ((opt = getopt(argc, argv, optstr)) != -1) {

		switch (opt) {
@@ -102,13 +107,19 @@ int main(int argc, char **argv) 
	ifindex = strtoul(argv[optind], NULL, 0);



	snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);

	prog_load_attr.file = filename;



	if (load_bpf_file(filename)) {

		printf("%s", bpf_log_buf);

	if (bpf_prog_load_xattr(&prog_load_attr, &obj, &prog_fd))

		return 1;



	map = bpf_map__next(NULL, obj);

	if (!map) {

		printf("finding a map in obj file failed\n");

		return 1;

	}

	map_fd = bpf_map__fd(map);



	if (!prog_fd[0]) {

	if (!prog_fd) {

		printf("load_bpf_file: %s\n", strerror(errno));

		return 1;

	}
@@ -116,12 +127,12 @@ int main(int argc, char **argv) 
	signal(SIGINT, int_exit);

	signal(SIGTERM, int_exit);



	if (bpf_set_link_xdp_fd(ifindex, prog_fd[0], xdp_flags) < 0) {

	if (bpf_set_link_xdp_fd(ifindex, prog_fd, xdp_flags) < 0) {

		printf("link set xdp fd failed\n");

		return 1;

	}



	poll_stats(2);

	poll_stats(map_fd, 2);



	return 0;

}

samples/bpf/xdp_adjust_tail_user.c

+22 −14
Original line number Diff line number Diff line
@@ -18,9 +18,8 @@ 
#include <netinet/ether.h>

#include <unistd.h>

#include <time.h>

#include "bpf_load.h"

#include "libbpf.h"

#include "bpf_util.h"

#include "bpf/bpf.h"

#include "bpf/libbpf.h"



#define STATS_INTERVAL_S 2U
@@ -36,7 +35,7 @@ static void int_exit(int sig) 


/* simple "icmp packet too big sent" counter

 */

static void poll_stats(unsigned int kill_after_s)

static void poll_stats(unsigned int map_fd, unsigned int kill_after_s)

{

	time_t started_at = time(NULL);

	__u64 value = 0;
@@ -46,7 +45,7 @@ static void poll_stats(unsigned int kill_after_s) 
	while (!kill_after_s || time(NULL) - started_at <= kill_after_s) {

		sleep(STATS_INTERVAL_S);



		assert(bpf_map_lookup_elem(map_fd[0], &key, &value) == 0);

		assert(bpf_map_lookup_elem(map_fd, &key, &value) == 0);



		printf("icmp \"packet too big\" sent: %10llu pkts\n", value);

	}
@@ -66,14 +65,17 @@ static void usage(const char *cmd) 


int main(int argc, char **argv)

{

	struct rlimit r = {RLIM_INFINITY, RLIM_INFINITY};

	struct bpf_prog_load_attr prog_load_attr = {

		.prog_type	= BPF_PROG_TYPE_XDP,

	};

	unsigned char opt_flags[256] = {};

	unsigned int kill_after_s = 0;

	const char *optstr = "i:T:SNh";

	struct rlimit r = {RLIM_INFINITY, RLIM_INFINITY};

	int i, prog_fd, map_fd, opt;

	struct bpf_object *obj;

	struct bpf_map *map;

	char filename[256];

	int opt;

	int i;





	for (i = 0; i < strlen(optstr); i++)

		if (optstr[i] != 'h' && 'a' <= optstr[i] && optstr[i] <= 'z')
@@ -115,13 +117,19 @@ int main(int argc, char **argv) 
	}



	snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);

	prog_load_attr.file = filename;



	if (bpf_prog_load_xattr(&prog_load_attr, &obj, &prog_fd))

		return 1;



	if (load_bpf_file(filename)) {

		printf("%s", bpf_log_buf);

	map = bpf_map__next(NULL, obj);

	if (!map) {

		printf("finding a map in obj file failed\n");

		return 1;

	}

	map_fd = bpf_map__fd(map);



	if (!prog_fd[0]) {

	if (!prog_fd) {

		printf("load_bpf_file: %s\n", strerror(errno));

		return 1;

	}
@@ -129,12 +137,12 @@ int main(int argc, char **argv) 
	signal(SIGINT, int_exit);

	signal(SIGTERM, int_exit);



	if (bpf_set_link_xdp_fd(ifindex, prog_fd[0], xdp_flags) < 0) {

	if (bpf_set_link_xdp_fd(ifindex, prog_fd, xdp_flags) < 0) {

		printf("link set xdp fd failed\n");

		return 1;

	}



	poll_stats(kill_after_s);

	poll_stats(map_fd, kill_after_s);



	bpf_set_link_xdp_fd(ifindex, -1, xdp_flags);

samples/bpf/xdp_rxq_info_user.c

+31 −15
Original line number Diff line number Diff line
@@ -22,8 +22,8 @@ static const char *__doc__ = " XDP RX-queue info extract example\n\n" 
#include <arpa/inet.h>

#include <linux/if_link.h>



#include "libbpf.h"

#include "bpf_load.h"

#include "bpf/bpf.h"

#include "bpf/libbpf.h"

#include "bpf_util.h"



static int ifindex = -1;
@@ -32,6 +32,9 @@ static char *ifname; 


static __u32 xdp_flags;



static struct bpf_map *stats_global_map;

static struct bpf_map *rx_queue_index_map;



/* Exit return codes */

#define EXIT_OK		0

#define EXIT_FAIL		1
@@ -174,7 +177,7 @@ static struct datarec *alloc_record_per_cpu(void) 


static struct record *alloc_record_per_rxq(void)

{

	unsigned int nr_rxqs = map_data[2].def.max_entries;

	unsigned int nr_rxqs = bpf_map__def(rx_queue_index_map)->max_entries;

	struct record *array;

	size_t size;
@@ -190,7 +193,7 @@ static struct record *alloc_record_per_rxq(void) 


static struct stats_record *alloc_stats_record(void)

{

	unsigned int nr_rxqs = map_data[2].def.max_entries;

	unsigned int nr_rxqs = bpf_map__def(rx_queue_index_map)->max_entries;

	struct stats_record *rec;

	int i;
@@ -210,7 +213,7 @@ static struct stats_record *alloc_stats_record(void) 


static void free_stats_record(struct stats_record *r)

{

	unsigned int nr_rxqs = map_data[2].def.max_entries;

	unsigned int nr_rxqs = bpf_map__def(rx_queue_index_map)->max_entries;

	int i;



	for (i = 0; i < nr_rxqs; i++)
@@ -254,11 +257,11 @@ static void stats_collect(struct stats_record *rec) 
{

	int fd, i, max_rxqs;



	fd = map_data[1].fd; /* map: stats_global_map */

	fd = bpf_map__fd(stats_global_map);

	map_collect_percpu(fd, 0, &rec->stats);



	fd = map_data[2].fd; /* map: rx_queue_index_map */

	max_rxqs = map_data[2].def.max_entries;

	fd = bpf_map__fd(rx_queue_index_map);

	max_rxqs = bpf_map__def(rx_queue_index_map)->max_entries;

	for (i = 0; i < max_rxqs; i++)

		map_collect_percpu(fd, i, &rec->rxq[i]);

}
@@ -304,8 +307,8 @@ static void stats_print(struct stats_record *stats_rec, 
			struct stats_record *stats_prev,

			int action)

{

	unsigned int nr_rxqs = bpf_map__def(rx_queue_index_map)->max_entries;

	unsigned int nr_cpus = bpf_num_possible_cpus();

	unsigned int nr_rxqs = map_data[2].def.max_entries;

	double pps = 0, err = 0;

	struct record *rec, *prev;

	double t;
@@ -419,31 +422,44 @@ static void stats_poll(int interval, int action) 
int main(int argc, char **argv)

{

	struct rlimit r = {10 * 1024 * 1024, RLIM_INFINITY};

	struct bpf_prog_load_attr prog_load_attr = {

		.prog_type	= BPF_PROG_TYPE_XDP,

	};

	int prog_fd, map_fd, opt, err;

	bool use_separators = true;

	struct config cfg = { 0 };

	struct bpf_object *obj;

	struct bpf_map *map;

	char filename[256];

	int longindex = 0;

	int interval = 2;

	__u32 key = 0;

	int opt, err;



	char action_str_buf[XDP_ACTION_MAX_STRLEN + 1 /* for \0 */] = { 0 };

	int action = XDP_PASS; /* Default action */

	char *action_str = NULL;



	snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);

	prog_load_attr.file = filename;



	if (setrlimit(RLIMIT_MEMLOCK, &r)) {

		perror("setrlimit(RLIMIT_MEMLOCK)");

		return 1;

	}



	if (load_bpf_file(filename)) {

		fprintf(stderr, "ERR in load_bpf_file(): %s", bpf_log_buf);

	if (bpf_prog_load_xattr(&prog_load_attr, &obj, &prog_fd))

		return EXIT_FAIL;



	map = bpf_map__next(NULL, obj);

	stats_global_map = bpf_map__next(map, obj);

	rx_queue_index_map = bpf_map__next(stats_global_map, obj);

	if (!map || !stats_global_map || !rx_queue_index_map) {

		printf("finding a map in obj file failed\n");

		return EXIT_FAIL;

	}

	map_fd = bpf_map__fd(map);



	if (!prog_fd[0]) {

	if (!prog_fd) {

		fprintf(stderr, "ERR: load_bpf_file: %s\n", strerror(errno));

		return EXIT_FAIL;

	}
@@ -512,7 +528,7 @@ int main(int argc, char **argv) 
		setlocale(LC_NUMERIC, "en_US");



	/* User-side setup ifindex in config_map */

	err = bpf_map_update_elem(map_fd[0], &key, &cfg, 0);

	err = bpf_map_update_elem(map_fd, &key, &cfg, 0);

	if (err) {

		fprintf(stderr, "Store config failed (err:%d)\n", err);

		exit(EXIT_FAIL_BPF);
@@ -521,7 +537,7 @@ int main(int argc, char **argv) 
	/* Remove XDP program when program is interrupted */

	signal(SIGINT, int_exit);



	if (bpf_set_link_xdp_fd(ifindex, prog_fd[0], xdp_flags) < 0) {

	if (bpf_set_link_xdp_fd(ifindex, prog_fd, xdp_flags) < 0) {

		fprintf(stderr, "link set xdp fd failed\n");

		return EXIT_FAIL_XDP;

	}