mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-08-23 17:30:02 +00:00
![Yafang Shao](/assets/img/avatar_default.png)
We have switched to memcg-based memory accouting and thus the rlimit is not needed any more. LIBBPF_STRICT_AUTO_RLIMIT_MEMLOCK was introduced in libbpf for backward compatibility, so we can use it instead now. This patch also removes the useless header sys/resource.h from many files in samples/bpf. Signed-off-by: Yafang Shao <laoar.shao@gmail.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20220409125958.92629-2-laoar.shao@gmail.com
198 lines
4.6 KiB
C
198 lines
4.6 KiB
C
/* SPDX-License-Identifier: GPL-2.0
|
|
* Copyright (c) 2018 Facebook
|
|
*
|
|
* This program is free software; you can redistribute it and/or
|
|
* modify it under the terms of version 2 of the GNU General Public
|
|
* License as published by the Free Software Foundation.
|
|
*/
|
|
#include <linux/bpf.h>
|
|
#include <linux/if_link.h>
|
|
#include <assert.h>
|
|
#include <errno.h>
|
|
#include <signal.h>
|
|
#include <stdio.h>
|
|
#include <stdlib.h>
|
|
#include <string.h>
|
|
#include <net/if.h>
|
|
#include <arpa/inet.h>
|
|
#include <netinet/ether.h>
|
|
#include <unistd.h>
|
|
#include <time.h>
|
|
#include <bpf/bpf.h>
|
|
#include <bpf/libbpf.h>
|
|
|
|
#define STATS_INTERVAL_S 2U
|
|
#define MAX_PCKT_SIZE 600
|
|
|
|
static int ifindex = -1;
|
|
static __u32 xdp_flags = XDP_FLAGS_UPDATE_IF_NOEXIST;
|
|
static __u32 prog_id;
|
|
|
|
static void int_exit(int sig)
|
|
{
|
|
__u32 curr_prog_id = 0;
|
|
|
|
if (ifindex > -1) {
|
|
if (bpf_xdp_query_id(ifindex, xdp_flags, &curr_prog_id)) {
|
|
printf("bpf_xdp_query_id failed\n");
|
|
exit(1);
|
|
}
|
|
if (prog_id == curr_prog_id)
|
|
bpf_xdp_detach(ifindex, xdp_flags, NULL);
|
|
else if (!curr_prog_id)
|
|
printf("couldn't find a prog id on a given iface\n");
|
|
else
|
|
printf("program on interface changed, not removing\n");
|
|
}
|
|
exit(0);
|
|
}
|
|
|
|
/* simple "icmp packet too big sent" counter
|
|
*/
|
|
static void poll_stats(unsigned int map_fd, unsigned int kill_after_s)
|
|
{
|
|
time_t started_at = time(NULL);
|
|
__u64 value = 0;
|
|
int key = 0;
|
|
|
|
|
|
while (!kill_after_s || time(NULL) - started_at <= kill_after_s) {
|
|
sleep(STATS_INTERVAL_S);
|
|
|
|
assert(bpf_map_lookup_elem(map_fd, &key, &value) == 0);
|
|
|
|
printf("icmp \"packet too big\" sent: %10llu pkts\n", value);
|
|
}
|
|
}
|
|
|
|
static void usage(const char *cmd)
|
|
{
|
|
printf("Start a XDP prog which send ICMP \"packet too big\" \n"
|
|
"messages if ingress packet is bigger then MAX_SIZE bytes\n");
|
|
printf("Usage: %s [...]\n", cmd);
|
|
printf(" -i <ifname|ifindex> Interface\n");
|
|
printf(" -T <stop-after-X-seconds> Default: 0 (forever)\n");
|
|
printf(" -P <MAX_PCKT_SIZE> Default: %u\n", MAX_PCKT_SIZE);
|
|
printf(" -S use skb-mode\n");
|
|
printf(" -N enforce native mode\n");
|
|
printf(" -F force loading prog\n");
|
|
printf(" -h Display this help\n");
|
|
}
|
|
|
|
int main(int argc, char **argv)
|
|
{
|
|
unsigned char opt_flags[256] = {};
|
|
const char *optstr = "i:T:P:SNFh";
|
|
struct bpf_prog_info info = {};
|
|
__u32 info_len = sizeof(info);
|
|
unsigned int kill_after_s = 0;
|
|
int i, prog_fd, map_fd, opt;
|
|
struct bpf_program *prog;
|
|
struct bpf_object *obj;
|
|
__u32 max_pckt_size = 0;
|
|
__u32 key = 0;
|
|
char filename[256];
|
|
int err;
|
|
|
|
for (i = 0; i < strlen(optstr); i++)
|
|
if (optstr[i] != 'h' && 'a' <= optstr[i] && optstr[i] <= 'z')
|
|
opt_flags[(unsigned char)optstr[i]] = 1;
|
|
|
|
while ((opt = getopt(argc, argv, optstr)) != -1) {
|
|
|
|
switch (opt) {
|
|
case 'i':
|
|
ifindex = if_nametoindex(optarg);
|
|
if (!ifindex)
|
|
ifindex = atoi(optarg);
|
|
break;
|
|
case 'T':
|
|
kill_after_s = atoi(optarg);
|
|
break;
|
|
case 'P':
|
|
max_pckt_size = atoi(optarg);
|
|
break;
|
|
case 'S':
|
|
xdp_flags |= XDP_FLAGS_SKB_MODE;
|
|
break;
|
|
case 'N':
|
|
/* default, set below */
|
|
break;
|
|
case 'F':
|
|
xdp_flags &= ~XDP_FLAGS_UPDATE_IF_NOEXIST;
|
|
break;
|
|
default:
|
|
usage(argv[0]);
|
|
return 1;
|
|
}
|
|
opt_flags[opt] = 0;
|
|
}
|
|
|
|
if (!(xdp_flags & XDP_FLAGS_SKB_MODE))
|
|
xdp_flags |= XDP_FLAGS_DRV_MODE;
|
|
|
|
for (i = 0; i < strlen(optstr); i++) {
|
|
if (opt_flags[(unsigned int)optstr[i]]) {
|
|
fprintf(stderr, "Missing argument -%c\n", optstr[i]);
|
|
usage(argv[0]);
|
|
return 1;
|
|
}
|
|
}
|
|
|
|
if (!ifindex) {
|
|
fprintf(stderr, "Invalid ifname\n");
|
|
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);
|
|
|
|
/* static global var 'max_pcktsz' is accessible from .data section */
|
|
if (max_pckt_size) {
|
|
map_fd = bpf_object__find_map_fd_by_name(obj, "xdp_adju.data");
|
|
if (map_fd < 0) {
|
|
printf("finding a max_pcktsz map in obj file failed\n");
|
|
return 1;
|
|
}
|
|
bpf_map_update_elem(map_fd, &key, &max_pckt_size, BPF_ANY);
|
|
}
|
|
|
|
/* fetch icmpcnt map */
|
|
map_fd = bpf_object__find_map_fd_by_name(obj, "icmpcnt");
|
|
if (map_fd < 0) {
|
|
printf("finding a icmpcnt map in obj file failed\n");
|
|
return 1;
|
|
}
|
|
|
|
signal(SIGINT, int_exit);
|
|
signal(SIGTERM, int_exit);
|
|
|
|
if (bpf_xdp_attach(ifindex, prog_fd, xdp_flags, NULL) < 0) {
|
|
printf("link set xdp fd failed\n");
|
|
return 1;
|
|
}
|
|
|
|
err = bpf_obj_get_info_by_fd(prog_fd, &info, &info_len);
|
|
if (err) {
|
|
printf("can't get prog info - %s\n", strerror(errno));
|
|
return 1;
|
|
}
|
|
prog_id = info.id;
|
|
|
|
poll_stats(map_fd, kill_after_s);
|
|
int_exit(0);
|
|
|
|
return 0;
|
|
}
|