From: Michael Jeanson Date: Tue, 6 Apr 2021 20:32:14 +0000 (-0400) Subject: Move getenv to libcommon X-Git-Tag: v2.13.0-rc1~121 X-Git-Url: https://git.lttng.org./?a=commitdiff_plain;h=910dcd720731c190adbfb9bb50c67bb9c4235003;p=lttng-ust.git Move getenv to libcommon Move it to libcommon since it can be used by any library. Change-Id: Ic09b643e3a91b2844fe9dc13eac55fe90f8e15c2 Signed-off-by: Michael Jeanson Signed-off-by: Mathieu Desnoyers --- diff --git a/src/common/Makefile.am b/src/common/Makefile.am index 2ab4bfdc..e75ee250 100644 --- a/src/common/Makefile.am +++ b/src/common/Makefile.am @@ -129,6 +129,8 @@ libsnprintf_la_SOURCES = \ # Common library libcommon_la_SOURCES = \ + getenv.c \ + getenv.h \ logging.c \ logging.h \ patient.c diff --git a/src/common/getenv.c b/src/common/getenv.c new file mode 100644 index 00000000..1909f4cf --- /dev/null +++ b/src/common/getenv.c @@ -0,0 +1,102 @@ +/* + * SPDX-License-Identifier: LGPL-2.1-only + * + * Copyright (C) 2017 Mathieu Desnoyers + */ + +#include +#include +#include +#include +#include +#include +#include "common/logging.h" +#include "common/macros.h" +#include "common/getenv.h" + +enum lttng_env_secure { + LTTNG_ENV_SECURE, + LTTNG_ENV_NOT_SECURE, +}; + +struct lttng_env { + const char *key; + enum lttng_env_secure secure; + char *value; +}; + +static +int lttng_ust_getenv_is_init = 0; + +static struct lttng_env lttng_env[] = { + /* + * LTTNG_UST_DEBUG is used directly by snprintf, because it + * needs to be already set for ERR() used in + * lttng_ust_getenv_init(). + */ + { "LTTNG_UST_DEBUG", LTTNG_ENV_NOT_SECURE, NULL, }, + + /* Env. var. which can be used in setuid/setgid executables. */ + { "LTTNG_UST_WITHOUT_BADDR_STATEDUMP", LTTNG_ENV_NOT_SECURE, NULL, }, + { "LTTNG_UST_REGISTER_TIMEOUT", LTTNG_ENV_NOT_SECURE, NULL, }, + + /* Env. var. which are not fetched in setuid/setgid executables. */ + { "LTTNG_UST_CLOCK_PLUGIN", LTTNG_ENV_SECURE, NULL, }, + { "LTTNG_UST_GETCPU_PLUGIN", LTTNG_ENV_SECURE, NULL, }, + { "LTTNG_UST_ALLOW_BLOCKING", LTTNG_ENV_SECURE, NULL, }, + { "HOME", LTTNG_ENV_SECURE, NULL, }, + { "LTTNG_HOME", LTTNG_ENV_SECURE, NULL, }, +}; + +static +int lttng_is_setuid_setgid(void) +{ + return geteuid() != getuid() || getegid() != getgid(); +} + +/* + * Wrapper over getenv that will only return the values of whitelisted + * environment variables when the current process is setuid and/or setgid. + */ +char *lttng_ust_getenv(const char *name) +{ + size_t i; + struct lttng_env *e; + bool found = false; + + if (!CMM_LOAD_SHARED(lttng_ust_getenv_is_init)) + abort(); + + for (i = 0; i < LTTNG_ARRAY_SIZE(lttng_env); i++) { + e = <tng_env[i]; + + if (strcmp(e->key, name) == 0) { + found = true; + break; + } + } + if (!found) { + return NULL; + } + return e->value; +} + +void lttng_ust_getenv_init(void) +{ + size_t i; + + if (CMM_LOAD_SHARED(lttng_ust_getenv_is_init)) + return; + + for (i = 0; i < LTTNG_ARRAY_SIZE(lttng_env); i++) { + struct lttng_env *e = <tng_env[i]; + + if (e->secure == LTTNG_ENV_SECURE && lttng_is_setuid_setgid()) { + ERR("Getting environment variable '%s' from setuid/setgid binary refused for security reasons.", + e->key); + continue; + } + e->value = getenv(e->key); + } + CMM_STORE_SHARED(lttng_ust_getenv_is_init, 1); +} diff --git a/src/common/getenv.h b/src/common/getenv.h new file mode 100644 index 00000000..9bfb9f0b --- /dev/null +++ b/src/common/getenv.h @@ -0,0 +1,29 @@ +/* + * SPDX-License-Identifier: LGPL-2.1-only + * + * Copyright (C) 2015 Mathieu Desnoyers + */ + +#ifndef _UST_COMMON_GETENV_H +#define _UST_COMMON_GETENV_H + +/* + * Always add the lttng-ust environment variables using the lttng_ust_getenv() + * infrastructure rather than using getenv() directly. This ensures that we + * don't trigger races between getenv() invoked by lttng-ust listener threads + * invoked concurrently with setenv() called by an otherwise single-threaded + * application thread. (the application is not aware that it runs with + * lttng-ust) + */ + +char *lttng_ust_getenv(const char *name) + __attribute__((visibility("hidden"))); + + +/* + * Initialize the internal filtered list of environment variables. + */ +void lttng_ust_getenv_init(void) + __attribute__((visibility("hidden"))); + +#endif /* _UST_COMMON_GETENV_H */ diff --git a/src/lib/lttng-ust-ctl/ustctl.c b/src/lib/lttng-ust-ctl/ustctl.c index 3561a722..96107fe7 100644 --- a/src/lib/lttng-ust-ctl/ustctl.c +++ b/src/lib/lttng-ust-ctl/ustctl.c @@ -28,7 +28,7 @@ #include "common/wait.h" #include "lib/lttng-ust/lttng-rb-clients.h" #include "common/clock.h" -#include "lib/lttng-ust/getenv.h" +#include "common/getenv.h" #include "lib/lttng-ust/lttng-tracer-core.h" #include "lib/lttng-ust/lttng-counter-client.h" diff --git a/src/lib/lttng-ust/Makefile.am b/src/lib/lttng-ust/Makefile.am index 3548a9e6..51a18352 100644 --- a/src/lib/lttng-ust/Makefile.am +++ b/src/lib/lttng-ust/Makefile.am @@ -87,7 +87,6 @@ liblttng_ust_runtime_la_SOURCES = \ lttng-ust-tracef-provider.h \ tracelog.c \ lttng-ust-tracelog-provider.h \ - getenv.h \ string-utils.c \ string-utils.h \ event-notifier-notification.c \ @@ -112,8 +111,6 @@ liblttng_ust_support_la_SOURCES = \ lttng-tracer.h \ lttng-tracer-core.h \ ust-core.c \ - getenv.h \ - getenv.c \ lttng-ust-dynamic-type.c \ lttng-rb-clients.h \ lttng-ring-buffer-client-template.h \ diff --git a/src/lib/lttng-ust/getcpu.c b/src/lib/lttng-ust/getcpu.c index 483f8131..1fb7b169 100644 --- a/src/lib/lttng-ust/getcpu.c +++ b/src/lib/lttng-ust/getcpu.c @@ -12,7 +12,7 @@ #include #include -#include "getenv.h" +#include "common/getenv.h" #include "lib/lttng-ust/getcpu.h" /* Function pointer to the current getcpu callback. */ diff --git a/src/lib/lttng-ust/getenv.c b/src/lib/lttng-ust/getenv.c deleted file mode 100644 index 0a7bffd8..00000000 --- a/src/lib/lttng-ust/getenv.c +++ /dev/null @@ -1,87 +0,0 @@ -/* - * SPDX-License-Identifier: LGPL-2.1-only - * - * Copyright (C) 2017 Mathieu Desnoyers - */ - -#include -#include -#include -#include -#include -#include "common/logging.h" -#include "common/macros.h" -#include "getenv.h" - -enum lttng_env_secure { - LTTNG_ENV_SECURE, - LTTNG_ENV_NOT_SECURE, -}; - -struct lttng_env { - const char *key; - enum lttng_env_secure secure; - char *value; -}; - -static struct lttng_env lttng_env[] = { - /* - * LTTNG_UST_DEBUG is used directly by snprintf, because it - * needs to be already set for ERR() used in - * lttng_ust_getenv_init(). - */ - { "LTTNG_UST_DEBUG", LTTNG_ENV_NOT_SECURE, NULL, }, - - /* Env. var. which can be used in setuid/setgid executables. */ - { "LTTNG_UST_WITHOUT_BADDR_STATEDUMP", LTTNG_ENV_NOT_SECURE, NULL, }, - { "LTTNG_UST_REGISTER_TIMEOUT", LTTNG_ENV_NOT_SECURE, NULL, }, - - /* Env. var. which are not fetched in setuid/setgid executables. */ - { "LTTNG_UST_CLOCK_PLUGIN", LTTNG_ENV_SECURE, NULL, }, - { "LTTNG_UST_GETCPU_PLUGIN", LTTNG_ENV_SECURE, NULL, }, - { "LTTNG_UST_ALLOW_BLOCKING", LTTNG_ENV_SECURE, NULL, }, - { "HOME", LTTNG_ENV_SECURE, NULL, }, - { "LTTNG_HOME", LTTNG_ENV_SECURE, NULL, }, -}; - -static -int lttng_is_setuid_setgid(void) -{ - return geteuid() != getuid() || getegid() != getgid(); -} - -char *lttng_ust_getenv(const char *name) -{ - size_t i; - struct lttng_env *e; - bool found = false; - - for (i = 0; i < LTTNG_ARRAY_SIZE(lttng_env); i++) { - e = <tng_env[i]; - - if (strcmp(e->key, name) == 0) { - found = true; - break; - } - } - if (!found) { - return NULL; - } - return e->value; -} - -void lttng_ust_getenv_init(void) -{ - size_t i; - - for (i = 0; i < LTTNG_ARRAY_SIZE(lttng_env); i++) { - struct lttng_env *e = <tng_env[i]; - - if (e->secure == LTTNG_ENV_SECURE && lttng_is_setuid_setgid()) { - ERR("Getting environment variable '%s' from setuid/setgid binary refused for security reasons.", - e->key); - continue; - } - e->value = getenv(e->key); - } -} diff --git a/src/lib/lttng-ust/getenv.h b/src/lib/lttng-ust/getenv.h deleted file mode 100644 index 61d49193..00000000 --- a/src/lib/lttng-ust/getenv.h +++ /dev/null @@ -1,25 +0,0 @@ -/* - * SPDX-License-Identifier: LGPL-2.1-only - * - * Copyright (C) 2015 Mathieu Desnoyers - */ - -#ifndef _COMPAT_GETENV_H -#define _COMPAT_GETENV_H - -/* - * Always add the lttng-ust environment variables using the lttng_ust_getenv() - * infrastructure rather than using getenv() directly. This ensures that we - * don't trigger races between getenv() invoked by lttng-ust listener threads - * invoked concurrently with setenv() called by an otherwise single-threaded - * application thread. (the application is not aware that it runs with - * lttng-ust) - */ - -char *lttng_ust_getenv(const char *name) - __attribute__((visibility("hidden"))); - -void lttng_ust_getenv_init(void) - __attribute__((visibility("hidden"))); - -#endif /* _COMPAT_GETENV_H */ diff --git a/src/lib/lttng-ust/lttng-clock.c b/src/lib/lttng-ust/lttng-clock.c index edda7ae9..61b8e55a 100644 --- a/src/lib/lttng-ust/lttng-clock.c +++ b/src/lib/lttng-ust/lttng-clock.c @@ -18,7 +18,7 @@ #include "common/logging.h" #include "clock.h" -#include "getenv.h" +#include "common/getenv.h" struct lttng_ust_trace_clock *lttng_ust_trace_clock; diff --git a/src/lib/lttng-ust/lttng-ust-comm.c b/src/lib/lttng-ust/lttng-ust-comm.c index 219ef5d2..2f6fe18f 100644 --- a/src/lib/lttng-ust/lttng-ust-comm.c +++ b/src/lib/lttng-ust/lttng-ust-comm.c @@ -51,7 +51,7 @@ #include "lttng-ust-statedump.h" #include "clock.h" #include "lib/lttng-ust/getcpu.h" -#include "getenv.h" +#include "common/getenv.h" #include "ust-events-internal.h" #include "context-internal.h" #include "common/align.h" diff --git a/src/lib/lttng-ust/lttng-ust-statedump.c b/src/lib/lttng-ust/lttng-ust-statedump.c index cd4df182..2dae71f9 100644 --- a/src/lib/lttng-ust/lttng-ust-statedump.c +++ b/src/lib/lttng-ust/lttng-ust-statedump.c @@ -21,7 +21,7 @@ #include "lttng-tracer-core.h" #include "lttng-ust-statedump.h" #include "jhash.h" -#include "getenv.h" +#include "common/getenv.h" #include "ust-events-internal.h" #define TRACEPOINT_DEFINE