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6f626d28 | 1 | /* |
c0c0989a | 2 | * SPDX-License-Identifier: LGPL-2.1-only |
6f626d28 | 3 | * |
c0c0989a | 4 | * Copyright (C) 2017 Mathieu Desnoyers <mathieu.desnoyers@efficios.com> |
6f626d28 MD |
5 | */ |
6 | ||
7 | #include <stdlib.h> | |
8 | #include <unistd.h> | |
9 | #include <stdbool.h> | |
b4051ad8 | 10 | #include <stddef.h> |
6f626d28 | 11 | #include <sys/types.h> |
9d315d6d MJ |
12 | #include "common/logging.h" |
13 | #include "common/macros.h" | |
6f626d28 MD |
14 | #include "getenv.h" |
15 | ||
16 | enum lttng_env_secure { | |
17 | LTTNG_ENV_SECURE, | |
18 | LTTNG_ENV_NOT_SECURE, | |
19 | }; | |
20 | ||
21 | struct lttng_env { | |
22 | const char *key; | |
23 | enum lttng_env_secure secure; | |
24 | char *value; | |
25 | }; | |
26 | ||
27 | static struct lttng_env lttng_env[] = { | |
28 | /* | |
29 | * LTTNG_UST_DEBUG is used directly by snprintf, because it | |
30 | * needs to be already set for ERR() used in | |
31 | * lttng_ust_getenv_init(). | |
32 | */ | |
33 | { "LTTNG_UST_DEBUG", LTTNG_ENV_NOT_SECURE, NULL, }, | |
34 | ||
35 | /* Env. var. which can be used in setuid/setgid executables. */ | |
36 | { "LTTNG_UST_WITHOUT_BADDR_STATEDUMP", LTTNG_ENV_NOT_SECURE, NULL, }, | |
37 | { "LTTNG_UST_REGISTER_TIMEOUT", LTTNG_ENV_NOT_SECURE, NULL, }, | |
38 | ||
39 | /* Env. var. which are not fetched in setuid/setgid executables. */ | |
40 | { "LTTNG_UST_CLOCK_PLUGIN", LTTNG_ENV_SECURE, NULL, }, | |
41 | { "LTTNG_UST_GETCPU_PLUGIN", LTTNG_ENV_SECURE, NULL, }, | |
b2c5f61a | 42 | { "LTTNG_UST_ALLOW_BLOCKING", LTTNG_ENV_SECURE, NULL, }, |
6f626d28 MD |
43 | { "HOME", LTTNG_ENV_SECURE, NULL, }, |
44 | { "LTTNG_HOME", LTTNG_ENV_SECURE, NULL, }, | |
45 | }; | |
46 | ||
47 | static | |
48 | int lttng_is_setuid_setgid(void) | |
49 | { | |
50 | return geteuid() != getuid() || getegid() != getgid(); | |
51 | } | |
52 | ||
4c41b460 | 53 | char *lttng_ust_getenv(const char *name) |
6f626d28 MD |
54 | { |
55 | size_t i; | |
56 | struct lttng_env *e; | |
57 | bool found = false; | |
58 | ||
59 | for (i = 0; i < LTTNG_ARRAY_SIZE(lttng_env); i++) { | |
60 | e = <tng_env[i]; | |
61 | ||
62 | if (strcmp(e->key, name) == 0) { | |
63 | found = true; | |
64 | break; | |
65 | } | |
66 | } | |
67 | if (!found) { | |
68 | return NULL; | |
69 | } | |
70 | return e->value; | |
71 | } | |
72 | ||
73 | void lttng_ust_getenv_init(void) | |
74 | { | |
75 | size_t i; | |
76 | ||
77 | for (i = 0; i < LTTNG_ARRAY_SIZE(lttng_env); i++) { | |
78 | struct lttng_env *e = <tng_env[i]; | |
79 | ||
80 | if (e->secure == LTTNG_ENV_SECURE && lttng_is_setuid_setgid()) { | |
81 | ERR("Getting environment variable '%s' from setuid/setgid binary refused for security reasons.", | |
82 | e->key); | |
83 | continue; | |
84 | } | |
85 | e->value = getenv(e->key); | |
86 | } | |
87 | } |