1 files changed, 81 insertions, 0 deletions
diff --git a/security/sandbox/linux/SandboxLogging.h b/security/sandbox/linux/SandboxLogging.h
new file mode 100644
index 0000000000..94467ececc
--- /dev/null
+++ b/security/sandbox/linux/SandboxLogging.h
@@ -0,0 +1,81 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef mozilla_SandboxLogging_h
+#define mozilla_SandboxLogging_h
+
+// This header defines the SANDBOX_LOG macro used in the Linux
+// sandboxing code.  It uses Android logging on Android and writes to
+// stderr otherwise.  Android logging has severity levels; currently
+// only "error" severity is exposed here, and this isn't marked when
+// writing to stderr.
+//
+// The format strings are processed by Chromium SafeSPrintf, which
+// doesn't accept size modifiers or %u because it uses C++11 variadic
+// templates to obtain the actual argument types; all decimal integer
+// formatting uses %d.  See safe_sprintf.h for more details.
+
+// Build SafeSPrintf without assertions to avoid a dependency on
+// Chromium logging.  This doesn't affect safety; it just means that
+// type mismatches (pointer vs. integer) always result in unexpanded
+// %-directives instead of crashing.  See also the moz.build files,
+// which apply NDEBUG to the .cc file.
+#ifndef NDEBUG
+#  define NDEBUG 1
+#  include "base/strings/safe_sprintf.h"
+#  undef NDEBUG
+#else
+#  include "base/strings/safe_sprintf.h"
+#endif
+
+#include <errno.h>
+
+namespace mozilla {
+// Logs the formatted string (marked with "error" severity, if supported).
+void SandboxLogError(const char* aMessage);
+
+// Writes into aBuf the identifier for an error number (e.g., "EINVAL"
+// rather than "Invalid argument"); may fall back to "error N" (with
+// the number) for unhandled errors.
+//
+// Bounds are handled like snprintf: the return value is the length
+// the string would have (not counting the null terminator) ignoring
+// buffer size, and the string written into the buffer may be
+// truncated to fit but is always null terminated.
+ssize_t GetLibcErrorName(char* aBuf, size_t aSize, int aErr);
+}  // namespace mozilla
+
+#define SANDBOX_LOG_LEN 256
+
+// Formats a log message and logs it (with "error" severity, if supported).
+//
+// Note that SafeSPrintf doesn't accept size modifiers or %u; all
+// decimal integers are %d, because it uses C++11 variadic templates
+// to use the actual argument type.
+#define SANDBOX_LOG(fmt, args...)                              \
+  do {                                                         \
+    char _sandboxLogBuf[SANDBOX_LOG_LEN];                      \
+    ::base::strings::SafeSPrintf(_sandboxLogBuf, fmt, ##args); \
+    ::mozilla::SandboxLogError(_sandboxLogBuf);                \
+  } while (0)
+
+#define SANDBOX_LOG_WITH_ERROR(errnum, fmt, args...)                       \
+  do {                                                                     \
+    char _sandboxLogBuf[SANDBOX_LOG_LEN];                                  \
+    ssize_t _sandboxLogOff =                                               \
+        ::base::strings::SafeSPrintf(_sandboxLogBuf, fmt ": ", ##args);    \
+    if (static_cast<size_t>(_sandboxLogOff) < sizeof(_sandboxLogBuf)) {    \
+      ::mozilla::GetLibcErrorName(_sandboxLogBuf + _sandboxLogOff,         \
+                                  sizeof(_sandboxLogBuf) - _sandboxLogOff, \
+                                  errnum);                                 \
+    }                                                                      \
+    ::mozilla::SandboxLogError(_sandboxLogBuf);                            \
+  } while (0)
+
+#define SANDBOX_LOG_ERRNO(fmt, args...) \
+  SANDBOX_LOG_WITH_ERROR(errno, fmt, ##args)
+
+#endif  // mozilla_SandboxLogging_h