linux/samples/bpf/xdp_tx_iptunnel_user.c
Maciej Fijalkowski 3b7a8ec2de samples/bpf: Check the prog id before exiting
Check the program id within the signal handler on polling xdp samples
that were previously converted to libbpf usage. Avoid the situation of
unloading the program that was not attached by sample that is exiting.
Handle also the case where bpf_get_link_xdp_id didn't exit with an error
but the xdp program was not found on an interface.

Reported-by: Michal Papaj <michal.papaj@intel.com>
Reported-by: Jakub Spizewski <jakub.spizewski@intel.com>
Signed-off-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2019-02-01 23:37:51 +01:00

307 lines
7.4 KiB
C

/* Copyright (c) 2016 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 <sys/resource.h>
#include <arpa/inet.h>
#include <netinet/ether.h>
#include <unistd.h>
#include <time.h>
#include "bpf/libbpf.h"
#include <bpf/bpf.h>
#include "bpf_util.h"
#include "xdp_tx_iptunnel_common.h"
#define STATS_INTERVAL_S 2U
static int ifindex = -1;
static __u32 xdp_flags = XDP_FLAGS_UPDATE_IF_NOEXIST;
static int rxcnt_map_fd;
static __u32 prog_id;
static void int_exit(int sig)
{
__u32 curr_prog_id = 0;
if (ifindex > -1) {
if (bpf_get_link_xdp_id(ifindex, &curr_prog_id, xdp_flags)) {
printf("bpf_get_link_xdp_id failed\n");
exit(1);
}
if (prog_id == curr_prog_id)
bpf_set_link_xdp_fd(ifindex, -1, xdp_flags);
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 per-protocol drop counter
*/
static void poll_stats(unsigned int kill_after_s)
{
const unsigned int nr_protos = 256;
unsigned int nr_cpus = bpf_num_possible_cpus();
time_t started_at = time(NULL);
__u64 values[nr_cpus], prev[nr_protos][nr_cpus];
__u32 proto;
int i;
memset(prev, 0, sizeof(prev));
while (!kill_after_s || time(NULL) - started_at <= kill_after_s) {
sleep(STATS_INTERVAL_S);
for (proto = 0; proto < nr_protos; proto++) {
__u64 sum = 0;
assert(bpf_map_lookup_elem(rxcnt_map_fd, &proto,
values) == 0);
for (i = 0; i < nr_cpus; i++)
sum += (values[i] - prev[proto][i]);
if (sum)
printf("proto %u: sum:%10llu pkts, rate:%10llu pkts/s\n",
proto, sum, sum / STATS_INTERVAL_S);
memcpy(prev[proto], values, sizeof(values));
}
}
}
static void usage(const char *cmd)
{
printf("Start a XDP prog which encapsulates incoming packets\n"
"in an IPv4/v6 header and XDP_TX it out. The dst <VIP:PORT>\n"
"is used to select packets to encapsulate\n\n");
printf("Usage: %s [...]\n", cmd);
printf(" -i <ifindex> Interface Index\n");
printf(" -a <vip-service-address> IPv4 or IPv6\n");
printf(" -p <vip-service-port> A port range (e.g. 433-444) is also allowed\n");
printf(" -s <source-ip> Used in the IPTunnel header\n");
printf(" -d <dest-ip> Used in the IPTunnel header\n");
printf(" -m <dest-MAC> Used in sending the IP Tunneled pkt\n");
printf(" -T <stop-after-X-seconds> Default: 0 (forever)\n");
printf(" -P <IP-Protocol> Default is TCP\n");
printf(" -S use skb-mode\n");
printf(" -N enforce native mode\n");
printf(" -F Force loading the XDP prog\n");
printf(" -h Display this help\n");
}
static int parse_ipstr(const char *ipstr, unsigned int *addr)
{
if (inet_pton(AF_INET6, ipstr, addr) == 1) {
return AF_INET6;
} else if (inet_pton(AF_INET, ipstr, addr) == 1) {
addr[1] = addr[2] = addr[3] = 0;
return AF_INET;
}
fprintf(stderr, "%s is an invalid IP\n", ipstr);
return AF_UNSPEC;
}
static int parse_ports(const char *port_str, int *min_port, int *max_port)
{
char *end;
long tmp_min_port;
long tmp_max_port;
tmp_min_port = strtol(optarg, &end, 10);
if (tmp_min_port < 1 || tmp_min_port > 65535) {
fprintf(stderr, "Invalid port(s):%s\n", optarg);
return 1;
}
if (*end == '-') {
end++;
tmp_max_port = strtol(end, NULL, 10);
if (tmp_max_port < 1 || tmp_max_port > 65535) {
fprintf(stderr, "Invalid port(s):%s\n", optarg);
return 1;
}
} else {
tmp_max_port = tmp_min_port;
}
if (tmp_min_port > tmp_max_port) {
fprintf(stderr, "Invalid port(s):%s\n", optarg);
return 1;
}
if (tmp_max_port - tmp_min_port + 1 > MAX_IPTNL_ENTRIES) {
fprintf(stderr, "Port range (%s) is larger than %u\n",
port_str, MAX_IPTNL_ENTRIES);
return 1;
}
*min_port = tmp_min_port;
*max_port = tmp_max_port;
return 0;
}
int main(int argc, char **argv)
{
struct bpf_prog_load_attr prog_load_attr = {
.prog_type = BPF_PROG_TYPE_XDP,
};
struct rlimit r = {RLIM_INFINITY, RLIM_INFINITY};
int min_port = 0, max_port = 0, vip2tnl_map_fd;
const char *optstr = "i:a:p:s:d:m:T:P:FSNh";
unsigned char opt_flags[256] = {};
struct bpf_prog_info info = {};
__u32 info_len = sizeof(info);
unsigned int kill_after_s = 0;
struct iptnl_info tnl = {};
struct bpf_object *obj;
struct vip vip = {};
char filename[256];
int opt, prog_fd;
int i, err;
tnl.family = AF_UNSPEC;
vip.protocol = IPPROTO_TCP;
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) {
unsigned short family;
unsigned int *v6;
switch (opt) {
case 'i':
ifindex = atoi(optarg);
break;
case 'a':
vip.family = parse_ipstr(optarg, vip.daddr.v6);
if (vip.family == AF_UNSPEC)
return 1;
break;
case 'p':
if (parse_ports(optarg, &min_port, &max_port))
return 1;
break;
case 'P':
vip.protocol = atoi(optarg);
break;
case 's':
case 'd':
if (opt == 's')
v6 = tnl.saddr.v6;
else
v6 = tnl.daddr.v6;
family = parse_ipstr(optarg, v6);
if (family == AF_UNSPEC)
return 1;
if (tnl.family == AF_UNSPEC) {
tnl.family = family;
} else if (tnl.family != family) {
fprintf(stderr,
"The IP version of the src and dst addresses used in the IP encapsulation does not match\n");
return 1;
}
break;
case 'm':
if (!ether_aton_r(optarg,
(struct ether_addr *)tnl.dmac)) {
fprintf(stderr, "Invalid mac address:%s\n",
optarg);
return 1;
}
break;
case 'T':
kill_after_s = atoi(optarg);
break;
case 'S':
xdp_flags |= XDP_FLAGS_SKB_MODE;
break;
case 'N':
xdp_flags |= XDP_FLAGS_DRV_MODE;
break;
case 'F':
xdp_flags &= ~XDP_FLAGS_UPDATE_IF_NOEXIST;
break;
default:
usage(argv[0]);
return 1;
}
opt_flags[opt] = 0;
}
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 (setrlimit(RLIMIT_MEMLOCK, &r)) {
perror("setrlimit(RLIMIT_MEMLOCK, RLIM_INFINITY)");
return 1;
}
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 (!prog_fd) {
printf("load_bpf_file: %s\n", strerror(errno));
return 1;
}
rxcnt_map_fd = bpf_object__find_map_fd_by_name(obj, "rxcnt");
vip2tnl_map_fd = bpf_object__find_map_fd_by_name(obj, "vip2tnl");
if (vip2tnl_map_fd < 0 || rxcnt_map_fd < 0) {
printf("bpf_object__find_map_fd_by_name failed\n");
return 1;
}
signal(SIGINT, int_exit);
signal(SIGTERM, int_exit);
while (min_port <= max_port) {
vip.dport = htons(min_port++);
if (bpf_map_update_elem(vip2tnl_map_fd, &vip, &tnl,
BPF_NOEXIST)) {
perror("bpf_map_update_elem(&vip2tnl)");
return 1;
}
}
if (bpf_set_link_xdp_fd(ifindex, prog_fd, xdp_flags) < 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 err;
}
prog_id = info.id;
poll_stats(kill_after_s);
bpf_set_link_xdp_fd(ifindex, -1, xdp_flags);
return 0;
}