/* Load tracked file descriptors from the environment. The environment is used
* to pass the information to child processes.
*
- * ENV_NAME_FDS has the following format: Each descriptor as string followed
- * by a comma; there's a trailing comma. Example: "2,4,". */
+ * ENV_NAME_FDS and ENV_NAME_PRIVATE_FDS have the following format: Each
+ * descriptor as string followed by a comma; there's a trailing comma.
+ * Example: "2,4,". */
static void init_from_environment(void) {
#ifdef DEBUG
debug("init_from_environment()\t\t[%d]\n", getpid());
int saved_errno = errno;
+ assert(!initialized);
+
initialized = 1;
tracked_fds_list_count = 0;
force_write_to_non_tty = 1;
}
+ /* Prefer user defined list of file descriptors, fall back to file
+ * descriptors passed through the environment from the parent process. */
env = getenv(ENV_NAME_FDS);
+ if (env) {
+ used_fds_set_by_user = 1;
+ } else {
+ env = getenv(ENV_NAME_PRIVATE_FDS);
+ }
if (!env) {
errno = saved_errno;
return;
}
#ifdef DEBUG
debug(" getenv(\"%s\"): \"%s\"\n", ENV_NAME_FDS, env);
+ debug(" getenv(\"%s\"): \"%s\"\n", ENV_NAME_PRIVATE_FDS, env);
#endif
+
/* Environment must be treated read-only. */
char env_copy[strlen(env) + 1];
strcpy(env_copy, env);
return;
}
+ int saved_errno = errno;
+
char env[update_environment_buffer_size()];
env[0] = 0;
update_environment_buffer(env);
#if 0
- debug(" setenv(\"%s\", \"%s\", 1)\n", ENV_NAME_FDS, env);
+ debug(" setenv(\"%s\", \"%s\", 1)\n", ENV_NAME_PRIVATE_FDS, env);
#endif
+ setenv(ENV_NAME_PRIVATE_FDS, env, 1 /* overwrite */);
- setenv(ENV_NAME_FDS, env, 1 /* overwrite */);
+ /* Child processes must use ENV_NAME_PRIVATE_FDS to get the updated list
+ * of tracked file descriptors, not the static list provided by the user
+ * in ENV_NAME_FDS.
+ *
+ * But only remove it if the static list in ENV_NAME_FDS was loaded by
+ * init_from_environment() and merged into ENV_NAME_PRIVATE_FDS. */
+ if (used_fds_set_by_user) {
+ unsetenv(ENV_NAME_FDS);
+ }
+
+ errno = saved_errno;
}