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samples: bpf: convert some XDP samples from bpf_load to libbpf
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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: Jakub Kicinski <[email protected]>
Reviewed-by: Quentin Monnet <[email protected]>
Signed-off-by: Daniel Borkmann <[email protected]>
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@borkmann
Jakub Kicinski authored and borkmann committed May 10, 2018
1 parent 17387dd commit be5bca4
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Showing 4 changed files with 78 additions and 43 deletions.
8 changes: 4 additions & 4 deletions samples/bpf/Makefile
View file
Original file line number Diff line number Diff line change
Expand Up @@ -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
Expand All @@ -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

Expand Down
31 changes: 21 additions & 10 deletions samples/bpf/xdp1_user.c
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Original file line number Diff line number Diff line change
Expand Up @@ -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;
Expand All @@ -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;
Expand All @@ -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)
Expand All @@ -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) {
Expand Down Expand Up @@ -102,26 +107,32 @@ 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;
}

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;
}
36 changes: 22 additions & 14 deletions samples/bpf/xdp_adjust_tail_user.c
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Original file line number Diff line number Diff line change
Expand Up @@ -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

Expand All @@ -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;
Expand All @@ -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);
}
Expand All @@ -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')
Expand Down Expand Up @@ -115,26 +117,32 @@ 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;
}

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);

Expand Down
46 changes: 31 additions & 15 deletions samples/bpf/xdp_rxq_info_user.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -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;
Expand All @@ -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
Expand Down Expand Up @@ -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;

Expand All @@ -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;

Expand All @@ -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++)
Expand Down Expand Up @@ -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]);
}
Expand Down Expand Up @@ -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;
Expand Down Expand Up @@ -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;
}
Expand Down Expand Up @@ -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);
Expand All @@ -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;
}
Expand Down

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