linux/samples/bpf/xdp_rxq_info_user.c
Jesper Dangaard Brouer 817b89beb9 samples/bpf: all XDP samples should unload xdp/bpf prog on SIGTERM
It is common XDP practice to unload/deattach the XDP bpf program,
when the XDP sample program is Ctrl-C interrupted (SIGINT) or
killed (SIGTERM).

The samples/bpf programs xdp_redirect_cpu and xdp_rxq_info,
forgot to trap signal SIGTERM (which is the default signal used
by the kill command).

This was discovered by Red Hat QA, which automated scripts depend
on killing the XDP sample program after a timeout period.

Fixes: fad3917e36 ("samples/bpf: add cpumap sample program xdp_redirect_cpu")
Fixes: 0fca931a6f ("samples/bpf: program demonstrating access to xdp_rxq_info")
Reported-by: Jean-Tsung Hsiao <jhsiao@redhat.com>
Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Acked-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-08-16 21:55:32 +02:00

582 lines
13 KiB
C

/* SPDX-License-Identifier: GPL-2.0
* Copyright (c) 2017 Jesper Dangaard Brouer, Red Hat Inc.
*/
static const char *__doc__ = " XDP RX-queue info extract example\n\n"
"Monitor how many packets per sec (pps) are received\n"
"per NIC RX queue index and which CPU processed the packet\n"
;
#include <errno.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <stdbool.h>
#include <string.h>
#include <unistd.h>
#include <locale.h>
#include <sys/resource.h>
#include <getopt.h>
#include <net/if.h>
#include <time.h>
#include <arpa/inet.h>
#include <linux/if_link.h>
#include "bpf/bpf.h"
#include "bpf/libbpf.h"
#include "bpf_util.h"
static int ifindex = -1;
static char ifname_buf[IF_NAMESIZE];
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
#define EXIT_FAIL_OPTION 2
#define EXIT_FAIL_XDP 3
#define EXIT_FAIL_BPF 4
#define EXIT_FAIL_MEM 5
static const struct option long_options[] = {
{"help", no_argument, NULL, 'h' },
{"dev", required_argument, NULL, 'd' },
{"skb-mode", no_argument, NULL, 'S' },
{"sec", required_argument, NULL, 's' },
{"no-separators", no_argument, NULL, 'z' },
{"action", required_argument, NULL, 'a' },
{"readmem", no_argument, NULL, 'r' },
{"swapmac", no_argument, NULL, 'm' },
{0, 0, NULL, 0 }
};
static void int_exit(int sig)
{
fprintf(stderr,
"Interrupted: Removing XDP program on ifindex:%d device:%s\n",
ifindex, ifname);
if (ifindex > -1)
bpf_set_link_xdp_fd(ifindex, -1, xdp_flags);
exit(EXIT_OK);
}
struct config {
__u32 action;
int ifindex;
__u32 options;
};
enum cfg_options_flags {
NO_TOUCH = 0x0U,
READ_MEM = 0x1U,
SWAP_MAC = 0x2U,
};
#define XDP_ACTION_MAX (XDP_TX + 1)
#define XDP_ACTION_MAX_STRLEN 11
static const char *xdp_action_names[XDP_ACTION_MAX] = {
[XDP_ABORTED] = "XDP_ABORTED",
[XDP_DROP] = "XDP_DROP",
[XDP_PASS] = "XDP_PASS",
[XDP_TX] = "XDP_TX",
};
static const char *action2str(int action)
{
if (action < XDP_ACTION_MAX)
return xdp_action_names[action];
return NULL;
}
static int parse_xdp_action(char *action_str)
{
size_t maxlen;
__u64 action = -1;
int i;
for (i = 0; i < XDP_ACTION_MAX; i++) {
maxlen = XDP_ACTION_MAX_STRLEN;
if (strncmp(xdp_action_names[i], action_str, maxlen) == 0) {
action = i;
break;
}
}
return action;
}
static void list_xdp_actions(void)
{
int i;
printf("Available XDP --action <options>\n");
for (i = 0; i < XDP_ACTION_MAX; i++)
printf("\t%s\n", xdp_action_names[i]);
printf("\n");
}
static char* options2str(enum cfg_options_flags flag)
{
if (flag == NO_TOUCH)
return "no_touch";
if (flag & SWAP_MAC)
return "swapmac";
if (flag & READ_MEM)
return "read";
fprintf(stderr, "ERR: Unknown config option flags");
exit(EXIT_FAIL);
}
static void usage(char *argv[])
{
int i;
printf("\nDOCUMENTATION:\n%s\n", __doc__);
printf(" Usage: %s (options-see-below)\n", argv[0]);
printf(" Listing options:\n");
for (i = 0; long_options[i].name != 0; i++) {
printf(" --%-12s", long_options[i].name);
if (long_options[i].flag != NULL)
printf(" flag (internal value:%d)",
*long_options[i].flag);
else
printf(" short-option: -%c",
long_options[i].val);
printf("\n");
}
printf("\n");
list_xdp_actions();
}
#define NANOSEC_PER_SEC 1000000000 /* 10^9 */
static __u64 gettime(void)
{
struct timespec t;
int res;
res = clock_gettime(CLOCK_MONOTONIC, &t);
if (res < 0) {
fprintf(stderr, "Error with gettimeofday! (%i)\n", res);
exit(EXIT_FAIL);
}
return (__u64) t.tv_sec * NANOSEC_PER_SEC + t.tv_nsec;
}
/* Common stats data record shared with _kern.c */
struct datarec {
__u64 processed;
__u64 issue;
};
struct record {
__u64 timestamp;
struct datarec total;
struct datarec *cpu;
};
struct stats_record {
struct record stats;
struct record *rxq;
};
static struct datarec *alloc_record_per_cpu(void)
{
unsigned int nr_cpus = bpf_num_possible_cpus();
struct datarec *array;
size_t size;
size = sizeof(struct datarec) * nr_cpus;
array = malloc(size);
memset(array, 0, size);
if (!array) {
fprintf(stderr, "Mem alloc error (nr_cpus:%u)\n", nr_cpus);
exit(EXIT_FAIL_MEM);
}
return array;
}
static struct record *alloc_record_per_rxq(void)
{
unsigned int nr_rxqs = bpf_map__def(rx_queue_index_map)->max_entries;
struct record *array;
size_t size;
size = sizeof(struct record) * nr_rxqs;
array = malloc(size);
memset(array, 0, size);
if (!array) {
fprintf(stderr, "Mem alloc error (nr_rxqs:%u)\n", nr_rxqs);
exit(EXIT_FAIL_MEM);
}
return array;
}
static struct stats_record *alloc_stats_record(void)
{
unsigned int nr_rxqs = bpf_map__def(rx_queue_index_map)->max_entries;
struct stats_record *rec;
int i;
rec = malloc(sizeof(*rec));
memset(rec, 0, sizeof(*rec));
if (!rec) {
fprintf(stderr, "Mem alloc error\n");
exit(EXIT_FAIL_MEM);
}
rec->rxq = alloc_record_per_rxq();
for (i = 0; i < nr_rxqs; i++)
rec->rxq[i].cpu = alloc_record_per_cpu();
rec->stats.cpu = alloc_record_per_cpu();
return rec;
}
static void free_stats_record(struct stats_record *r)
{
unsigned int nr_rxqs = bpf_map__def(rx_queue_index_map)->max_entries;
int i;
for (i = 0; i < nr_rxqs; i++)
free(r->rxq[i].cpu);
free(r->rxq);
free(r->stats.cpu);
free(r);
}
static bool map_collect_percpu(int fd, __u32 key, struct record *rec)
{
/* For percpu maps, userspace gets a value per possible CPU */
unsigned int nr_cpus = bpf_num_possible_cpus();
struct datarec values[nr_cpus];
__u64 sum_processed = 0;
__u64 sum_issue = 0;
int i;
if ((bpf_map_lookup_elem(fd, &key, values)) != 0) {
fprintf(stderr,
"ERR: bpf_map_lookup_elem failed key:0x%X\n", key);
return false;
}
/* Get time as close as possible to reading map contents */
rec->timestamp = gettime();
/* Record and sum values from each CPU */
for (i = 0; i < nr_cpus; i++) {
rec->cpu[i].processed = values[i].processed;
sum_processed += values[i].processed;
rec->cpu[i].issue = values[i].issue;
sum_issue += values[i].issue;
}
rec->total.processed = sum_processed;
rec->total.issue = sum_issue;
return true;
}
static void stats_collect(struct stats_record *rec)
{
int fd, i, max_rxqs;
fd = bpf_map__fd(stats_global_map);
map_collect_percpu(fd, 0, &rec->stats);
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]);
}
static double calc_period(struct record *r, struct record *p)
{
double period_ = 0;
__u64 period = 0;
period = r->timestamp - p->timestamp;
if (period > 0)
period_ = ((double) period / NANOSEC_PER_SEC);
return period_;
}
static __u64 calc_pps(struct datarec *r, struct datarec *p, double period_)
{
__u64 packets = 0;
__u64 pps = 0;
if (period_ > 0) {
packets = r->processed - p->processed;
pps = packets / period_;
}
return pps;
}
static __u64 calc_errs_pps(struct datarec *r,
struct datarec *p, double period_)
{
__u64 packets = 0;
__u64 pps = 0;
if (period_ > 0) {
packets = r->issue - p->issue;
pps = packets / period_;
}
return pps;
}
static void stats_print(struct stats_record *stats_rec,
struct stats_record *stats_prev,
int action, __u32 cfg_opt)
{
unsigned int nr_rxqs = bpf_map__def(rx_queue_index_map)->max_entries;
unsigned int nr_cpus = bpf_num_possible_cpus();
double pps = 0, err = 0;
struct record *rec, *prev;
double t;
int rxq;
int i;
/* Header */
printf("\nRunning XDP on dev:%s (ifindex:%d) action:%s options:%s\n",
ifname, ifindex, action2str(action), options2str(cfg_opt));
/* stats_global_map */
{
char *fmt_rx = "%-15s %-7d %'-11.0f %'-10.0f %s\n";
char *fm2_rx = "%-15s %-7s %'-11.0f\n";
char *errstr = "";
printf("%-15s %-7s %-11s %-11s\n",
"XDP stats", "CPU", "pps", "issue-pps");
rec = &stats_rec->stats;
prev = &stats_prev->stats;
t = calc_period(rec, prev);
for (i = 0; i < nr_cpus; i++) {
struct datarec *r = &rec->cpu[i];
struct datarec *p = &prev->cpu[i];
pps = calc_pps (r, p, t);
err = calc_errs_pps(r, p, t);
if (err > 0)
errstr = "invalid-ifindex";
if (pps > 0)
printf(fmt_rx, "XDP-RX CPU",
i, pps, err, errstr);
}
pps = calc_pps (&rec->total, &prev->total, t);
err = calc_errs_pps(&rec->total, &prev->total, t);
printf(fm2_rx, "XDP-RX CPU", "total", pps, err);
}
/* rx_queue_index_map */
printf("\n%-15s %-7s %-11s %-11s\n",
"RXQ stats", "RXQ:CPU", "pps", "issue-pps");
for (rxq = 0; rxq < nr_rxqs; rxq++) {
char *fmt_rx = "%-15s %3d:%-3d %'-11.0f %'-10.0f %s\n";
char *fm2_rx = "%-15s %3d:%-3s %'-11.0f\n";
char *errstr = "";
int rxq_ = rxq;
/* Last RXQ in map catch overflows */
if (rxq_ == nr_rxqs - 1)
rxq_ = -1;
rec = &stats_rec->rxq[rxq];
prev = &stats_prev->rxq[rxq];
t = calc_period(rec, prev);
for (i = 0; i < nr_cpus; i++) {
struct datarec *r = &rec->cpu[i];
struct datarec *p = &prev->cpu[i];
pps = calc_pps (r, p, t);
err = calc_errs_pps(r, p, t);
if (err > 0) {
if (rxq_ == -1)
errstr = "map-overflow-RXQ";
else
errstr = "err";
}
if (pps > 0)
printf(fmt_rx, "rx_queue_index",
rxq_, i, pps, err, errstr);
}
pps = calc_pps (&rec->total, &prev->total, t);
err = calc_errs_pps(&rec->total, &prev->total, t);
if (pps || err)
printf(fm2_rx, "rx_queue_index", rxq_, "sum", pps, err);
}
}
/* Pointer swap trick */
static inline void swap(struct stats_record **a, struct stats_record **b)
{
struct stats_record *tmp;
tmp = *a;
*a = *b;
*b = tmp;
}
static void stats_poll(int interval, int action, __u32 cfg_opt)
{
struct stats_record *record, *prev;
record = alloc_stats_record();
prev = alloc_stats_record();
stats_collect(record);
while (1) {
swap(&prev, &record);
stats_collect(record);
stats_print(record, prev, action, cfg_opt);
sleep(interval);
}
free_stats_record(record);
free_stats_record(prev);
}
int main(int argc, char **argv)
{
__u32 cfg_options= NO_TOUCH ; /* Default: Don't touch packet memory */
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;
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 (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) {
fprintf(stderr, "ERR: load_bpf_file: %s\n", strerror(errno));
return EXIT_FAIL;
}
/* Parse commands line args */
while ((opt = getopt_long(argc, argv, "hSd:",
long_options, &longindex)) != -1) {
switch (opt) {
case 'd':
if (strlen(optarg) >= IF_NAMESIZE) {
fprintf(stderr, "ERR: --dev name too long\n");
goto error;
}
ifname = (char *)&ifname_buf;
strncpy(ifname, optarg, IF_NAMESIZE);
ifindex = if_nametoindex(ifname);
if (ifindex == 0) {
fprintf(stderr,
"ERR: --dev name unknown err(%d):%s\n",
errno, strerror(errno));
goto error;
}
break;
case 's':
interval = atoi(optarg);
break;
case 'S':
xdp_flags |= XDP_FLAGS_SKB_MODE;
break;
case 'z':
use_separators = false;
break;
case 'a':
action_str = (char *)&action_str_buf;
strncpy(action_str, optarg, XDP_ACTION_MAX_STRLEN);
break;
case 'r':
cfg_options |= READ_MEM;
break;
case 'm':
cfg_options |= SWAP_MAC;
break;
case 'h':
error:
default:
usage(argv);
return EXIT_FAIL_OPTION;
}
}
/* Required option */
if (ifindex == -1) {
fprintf(stderr, "ERR: required option --dev missing\n");
usage(argv);
return EXIT_FAIL_OPTION;
}
cfg.ifindex = ifindex;
/* Parse action string */
if (action_str) {
action = parse_xdp_action(action_str);
if (action < 0) {
fprintf(stderr, "ERR: Invalid XDP --action: %s\n",
action_str);
list_xdp_actions();
return EXIT_FAIL_OPTION;
}
}
cfg.action = action;
/* XDP_TX requires changing MAC-addrs, else HW may drop */
if (action == XDP_TX)
cfg_options |= SWAP_MAC;
cfg.options = cfg_options;
/* Trick to pretty printf with thousands separators use %' */
if (use_separators)
setlocale(LC_NUMERIC, "en_US");
/* User-side setup ifindex in config_map */
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);
}
/* Remove XDP program when program is interrupted or killed */
signal(SIGINT, int_exit);
signal(SIGTERM, int_exit);
if (bpf_set_link_xdp_fd(ifindex, prog_fd, xdp_flags) < 0) {
fprintf(stderr, "link set xdp fd failed\n");
return EXIT_FAIL_XDP;
}
stats_poll(interval, action, cfg_options);
return EXIT_OK;
}