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// SPDX-License-Identifier: GPL-2.0
// Copyright (c) 2018 Facebook
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <arpa/inet.h>
#include <net/if.h>
#include <netinet/in.h>
#include <sys/socket.h>
#include <sys/types.h>
#include <bpf/bpf.h>
#include <bpf/libbpf.h>
#include "bpf_rlimit.h"
#include "cgroup_helpers.h"
#define CGROUP_PATH "/skb_cgroup_test"
#define NUM_CGROUP_LEVELS 4
/* RFC 4291, Section 2.7.1 */
#define LINKLOCAL_MULTICAST "ff02::1"
static int mk_dst_addr(const char *ip, const char *iface,
struct sockaddr_in6 *dst)
{
memset(dst, 0, sizeof(*dst));
dst->sin6_family = AF_INET6;
dst->sin6_port = htons(1025);
if (inet_pton(AF_INET6, ip, &dst->sin6_addr) != 1) {
log_err("Invalid IPv6: %s", ip);
return -1;
}
dst->sin6_scope_id = if_nametoindex(iface);
if (!dst->sin6_scope_id) {
log_err("Failed to get index of iface: %s", iface);
return -1;
}
return 0;
}
static int send_packet(const char *iface)
{
struct sockaddr_in6 dst;
char msg[] = "msg";
int err = 0;
int fd = -1;
if (mk_dst_addr(LINKLOCAL_MULTICAST, iface, &dst))
goto err;
fd = socket(AF_INET6, SOCK_DGRAM, 0);
if (fd == -1) {
log_err("Failed to create UDP socket");
goto err;
}
if (sendto(fd, &msg, sizeof(msg), 0, (const struct sockaddr *)&dst,
sizeof(dst)) == -1) {
log_err("Failed to send datagram");
goto err;
}
goto out;
err:
err = -1;
out:
if (fd >= 0)
close(fd);
return err;
}
int get_map_fd_by_prog_id(int prog_id)
{
struct bpf_prog_info info = {};
__u32 info_len = sizeof(info);
__u32 map_ids[1];
int prog_fd = -1;
int map_fd = -1;
prog_fd = bpf_prog_get_fd_by_id(prog_id);
if (prog_fd < 0) {
log_err("Failed to get fd by prog id %d", prog_id);
goto err;
}
info.nr_map_ids = 1;
info.map_ids = (__u64) (unsigned long) map_ids;
if (bpf_obj_get_info_by_fd(prog_fd, &info, &info_len)) {
log_err("Failed to get info by prog fd %d", prog_fd);
goto err;
}
if (!info.nr_map_ids) {
log_err("No maps found for prog fd %d", prog_fd);
goto err;
}
map_fd = bpf_map_get_fd_by_id(map_ids[0]);
if (map_fd < 0)
log_err("Failed to get fd by map id %d", map_ids[0]);
err:
if (prog_fd >= 0)
close(prog_fd);
return map_fd;
}
int check_ancestor_cgroup_ids(int prog_id)
{
__u64 actual_ids[NUM_CGROUP_LEVELS], expected_ids[NUM_CGROUP_LEVELS];
__u32 level;
int err = 0;
int map_fd;
expected_ids[0] = get_cgroup_id("/.."); /* root cgroup */
expected_ids[1] = get_cgroup_id("");
expected_ids[2] = get_cgroup_id(CGROUP_PATH);
expected_ids[3] = 0; /* non-existent cgroup */
map_fd = get_map_fd_by_prog_id(prog_id);
if (map_fd < 0)
goto err;
for (level = 0; level < NUM_CGROUP_LEVELS; ++level) {
if (bpf_map_lookup_elem(map_fd, &level, &actual_ids[level])) {
log_err("Failed to lookup key %d", level);
goto err;
}
if (actual_ids[level] != expected_ids[level]) {
log_err("%llx (actual) != %llx (expected), level: %u\n",
actual_ids[level], expected_ids[level], level);
goto err;
}
}
goto out;
err:
err = -1;
out:
if (map_fd >= 0)
close(map_fd);
return err;
}
int main(int argc, char **argv)
{
int cgfd = -1;
int err = 0;
if (argc < 3) {
fprintf(stderr, "Usage: %s iface prog_id\n", argv[0]);
exit(EXIT_FAILURE);
}
if (setup_cgroup_environment())
goto err;
cgfd = create_and_get_cgroup(CGROUP_PATH);
if (cgfd < 0)
goto err;
if (join_cgroup(CGROUP_PATH))
goto err;
if (send_packet(argv[1]))
goto err;
if (check_ancestor_cgroup_ids(atoi(argv[2])))
goto err;
goto out;
err:
err = -1;
out:
close(cgfd);
cleanup_cgroup_environment();
printf("[%s]\n", err ? "FAIL" : "PASS");
return err;
}
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