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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 | // 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 "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_prog_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); } /* Use libbpf 1.0 API mode */ libbpf_set_strict_mode(LIBBPF_STRICT_ALL); cgfd = cgroup_setup_and_join(CGROUP_PATH); if (cgfd < 0) 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; } |