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