Initial checkin of gRPC to third_party/

third_party/grpc/src/core/support/env_linux.c

Index: third_party/grpc/src/core/support/env_linux.c
diff --git a/third_party/grpc/src/core/support/env_linux.c b/third_party/grpc/src/core/support/env_linux.c
new file mode 100644
index 0000000000000000000000000000000000000000..fe51f846b710f65dfb8a5e5034f52b787cb729b4
--- /dev/null
+++ b/third_party/grpc/src/core/support/env_linux.c
@@ -0,0 +1,89 @@
+/*
+ *
+ * Copyright 2015-2016, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+/* for secure_getenv. */
+#ifndef _GNU_SOURCE
+#define _GNU_SOURCE
+#endif
+
+#include <grpc/support/port_platform.h>
+
+#ifdef GPR_LINUX_ENV
+
+#include "src/core/support/env.h"
+
+#include <dlfcn.h>
+#include <features.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include <grpc/support/log.h>
+#include <grpc/support/string_util.h>
+#include <grpc/support/useful.h>
+
+#include "src/core/support/string.h"
+
+char *gpr_getenv(const char *name) {
+#if defined(GPR_BACKWARDS_COMPATIBILITY_MODE)
+  typedef char *(*getenv_type)(const char *);
+  static getenv_type getenv_func = NULL;
+  /* Check to see which getenv variant is supported (go from most
+   * to least secure) */
+  const char *names[] = {"secure_getenv", "__secure_getenv", "getenv"};
+  for (size_t i = 0; getenv_func == NULL && i < GPR_ARRAY_SIZE(names); i++) {
+    getenv_func = (getenv_type)dlsym(RTLD_DEFAULT, names[i]);
+    if (getenv_func != NULL && strstr(names[i], "secure") == NULL) {
+      gpr_log(GPR_DEBUG,
+              "Warning: insecure environment read function '%s' used",
+              names[i]);
+    }
+  }
+  char *result = getenv_func(name);
+  return result == NULL ? result : gpr_strdup(result);
+#elif __GLIBC__ > 2 || (__GLIBC__ == 2 && __GLIBC_MINOR__ >= 17)
+  char *result = secure_getenv(name);
+  return result == NULL ? result : gpr_strdup(result);
+#else
+  gpr_log(GPR_DEBUG, "Warning: insecure environment read function '%s' used",
+          "getenv");
+  char *result = getenv(name);
+  return result == NULL ? result : gpr_strdup(result);
+#endif
+}
+
+void gpr_setenv(const char *name, const char *value) {
+  int res = setenv(name, value, 1);
+  GPR_ASSERT(res == 0);
+}
+
+#endif /* GPR_LINUX_ENV */