Jorge Lucangeli Obes | ac9e342 | 2016-02-03 15:00:42 -0800 | [diff] [blame] | 1 | // Copyright (C) 2016 The Android Open Source Project |
| 2 | // |
| 3 | // Licensed under the Apache License, Version 2.0 (the "License"); |
| 4 | // you may not use this file except in compliance with the License. |
| 5 | // You may obtain a copy of the License at |
| 6 | // |
| 7 | // http://www.apache.org/licenses/LICENSE-2.0 |
| 8 | // |
| 9 | // Unless required by applicable law or agreed to in writing, software |
| 10 | // distributed under the License is distributed on an "AS IS" BASIS, |
| 11 | // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 12 | // See the License for the specific language governing permissions and |
| 13 | // limitations under the License. |
| 14 | |
| 15 | #include <sys/types.h> |
| 16 | #include <sys/capability.h> |
| 17 | #include <unistd.h> |
| 18 | |
| 19 | #include <libminijail.h> |
| 20 | |
| 21 | #include <android-base/logging.h> |
| 22 | |
| 23 | const uid_t kSystemUid = 1000U; |
| 24 | |
| 25 | gid_t groups[] = { kSystemUid + 1, kSystemUid + 2 }; |
| 26 | |
| 27 | size_t getgroups_with_alloc(gid_t **plist) { |
| 28 | *plist = NULL; |
| 29 | |
| 30 | int nsupp_groups = getgroups(0, NULL); |
| 31 | if (nsupp_groups < 0) { |
| 32 | PLOG(ERROR) << "getgroups(0)"; |
| 33 | return 0; |
| 34 | } |
| 35 | if (nsupp_groups == 0) { |
Jorge Lucangeli Obes | 0e3fe53 | 2016-02-04 21:27:47 -0800 | [diff] [blame^] | 36 | LOG(INFO) << "No supplementary groups."; |
Jorge Lucangeli Obes | ac9e342 | 2016-02-03 15:00:42 -0800 | [diff] [blame] | 37 | return 0; |
| 38 | } |
| 39 | |
| 40 | *plist = (gid_t*)calloc((size_t)nsupp_groups, sizeof(gid_t)); |
| 41 | nsupp_groups = getgroups(nsupp_groups, *plist); |
| 42 | if (nsupp_groups < 0) { |
| 43 | PLOG(ERROR) << "getgroups(nsupp_groups)"; |
| 44 | free(*plist); |
| 45 | return 0; |
| 46 | } |
| 47 | return nsupp_groups; |
| 48 | } |
| 49 | |
| 50 | bool check_ugid(uid_t expected_id) { |
| 51 | bool success = true; |
Jorge Lucangeli Obes | 0e3fe53 | 2016-02-04 21:27:47 -0800 | [diff] [blame^] | 52 | |
Jorge Lucangeli Obes | ac9e342 | 2016-02-03 15:00:42 -0800 | [diff] [blame] | 53 | uid_t ruid = getuid(); |
| 54 | if (ruid != expected_id) { |
Jorge Lucangeli Obes | 0e3fe53 | 2016-02-04 21:27:47 -0800 | [diff] [blame^] | 55 | LOG(ERROR) << "rUID " << ruid << " is not " << expected_id; |
Jorge Lucangeli Obes | ac9e342 | 2016-02-03 15:00:42 -0800 | [diff] [blame] | 56 | success = false; |
| 57 | } |
| 58 | gid_t rgid = getgid(); |
| 59 | if (rgid != expected_id) { |
Jorge Lucangeli Obes | 0e3fe53 | 2016-02-04 21:27:47 -0800 | [diff] [blame^] | 60 | LOG(ERROR) << "rGID " << ruid << " is not " << expected_id; |
Jorge Lucangeli Obes | ac9e342 | 2016-02-03 15:00:42 -0800 | [diff] [blame] | 61 | success = false; |
| 62 | } |
| 63 | return success; |
| 64 | } |
| 65 | |
Jorge Lucangeli Obes | 0e3fe53 | 2016-02-04 21:27:47 -0800 | [diff] [blame^] | 66 | bool check_groups(size_t expected_size, gid_t *expected_list) { |
| 67 | bool success = true; |
| 68 | |
| 69 | gid_t *actual_list; |
| 70 | size_t actual_size = getgroups_with_alloc(&actual_list); |
| 71 | |
| 72 | if (expected_size != actual_size) { |
| 73 | LOG(ERROR) << "Mismatched supplementary group list size: expected " |
| 74 | << expected_size << ", actual " << actual_size; |
| 75 | success = false; |
| 76 | } |
| 77 | |
| 78 | for (size_t i = 0; i < expected_size; i++) { |
| 79 | bool found = false; |
| 80 | for (size_t j = 0; j < actual_size; j++) { |
| 81 | if (expected_list[i] == actual_list[j]) { |
| 82 | // Test next expected GID. |
| 83 | found = true; |
| 84 | break; |
| 85 | } |
| 86 | } |
| 87 | if (!found) { |
| 88 | LOG(ERROR) << "Expected GID " << expected_list[i] << " not found."; |
| 89 | success = false; |
| 90 | } |
| 91 | } |
| 92 | free(actual_list); |
| 93 | return success; |
| 94 | } |
| 95 | |
Jorge Lucangeli Obes | ac9e342 | 2016-02-03 15:00:42 -0800 | [diff] [blame] | 96 | void log_resugid() { |
| 97 | uid_t ruid, euid, suid; |
| 98 | gid_t rgid, egid, sgid; |
| 99 | getresuid(&ruid, &euid, &suid); |
| 100 | getresgid(&rgid, &egid, &sgid); |
| 101 | |
| 102 | LOG(INFO) << "ruid " << ruid << " euid " << euid << " suid " << suid; |
| 103 | LOG(INFO) << "rgid " << rgid << " egid " << egid << " sgid " << sgid; |
| 104 | |
| 105 | gid_t *list; |
| 106 | size_t nsupp_groups = getgroups_with_alloc(&list); |
| 107 | for (size_t i = 0; i < (size_t)nsupp_groups; i++) { |
| 108 | LOG(INFO) << "supp gid " << i + 1 << " " << list[i]; |
| 109 | } |
| 110 | free(list); |
| 111 | } |
| 112 | |
| 113 | int main(void) { |
Jorge Lucangeli Obes | ac9e342 | 2016-02-03 15:00:42 -0800 | [diff] [blame] | 114 | minijail *j = minijail_new(); |
| 115 | minijail_change_user(j, "system"); |
| 116 | minijail_change_group(j, "system"); |
Jorge Lucangeli Obes | 0e3fe53 | 2016-02-04 21:27:47 -0800 | [diff] [blame^] | 117 | size_t num_groups = sizeof(groups) / sizeof(groups[0]); |
| 118 | minijail_set_supplementary_gids(j, num_groups, groups); |
Jorge Lucangeli Obes | ac9e342 | 2016-02-03 15:00:42 -0800 | [diff] [blame] | 119 | minijail_use_caps(j, CAP_TO_MASK(CAP_SETUID) | CAP_TO_MASK(CAP_SETGID)); |
| 120 | minijail_enter(j); |
| 121 | |
Jorge Lucangeli Obes | 0e3fe53 | 2016-02-04 21:27:47 -0800 | [diff] [blame^] | 122 | bool success = check_ugid(kSystemUid); |
| 123 | success = success && check_groups(num_groups, groups); |
Jorge Lucangeli Obes | ac9e342 | 2016-02-03 15:00:42 -0800 | [diff] [blame] | 124 | |
| 125 | minijail_destroy(j); |
| 126 | minijail *j2 = minijail_new(); |
| 127 | minijail_change_uid(j2, 5 * kSystemUid); |
| 128 | minijail_change_gid(j2, 5 * kSystemUid); |
| 129 | minijail_enter(j2); |
| 130 | |
Jorge Lucangeli Obes | 0e3fe53 | 2016-02-04 21:27:47 -0800 | [diff] [blame^] | 131 | success = success && check_ugid(5 * kSystemUid); |
Jorge Lucangeli Obes | ac9e342 | 2016-02-03 15:00:42 -0800 | [diff] [blame] | 132 | |
Jorge Lucangeli Obes | 0e3fe53 | 2016-02-04 21:27:47 -0800 | [diff] [blame^] | 133 | return success? 0 : 1; |
Jorge Lucangeli Obes | ac9e342 | 2016-02-03 15:00:42 -0800 | [diff] [blame] | 134 | } |