1 files changed, 141 insertions, 0 deletions
diff --git a/security/sandbox/linux/SandboxLogging.cpp b/security/sandbox/linux/SandboxLogging.cpp
new file mode 100644
index 0000000000..de858a3606
--- /dev/null
+++ b/security/sandbox/linux/SandboxLogging.cpp
@@ -0,0 +1,141 @@
+/* -*- 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/. */
+
+#include "SandboxLogging.h"
+
+#ifdef ANDROID
+#  include <android/log.h>
+#endif
+#include <algorithm>
+#include <stdio.h>
+#include <string.h>
+#include <sys/uio.h>
+#include <unistd.h>
+
+#include "base/posix/eintr_wrapper.h"
+
+#ifdef __GLIBC_PREREQ
+#  if __GLIBC_PREREQ(2, 32)
+#    define HAVE_STRERRORNAME_NP 1
+#  endif
+#endif
+
+namespace mozilla {
+
+// Alters an iovec array to remove the first `toDrop` bytes.  This
+// complexity is necessary because writev can return a short write
+// (e.g., if stderr is a pipe and the buffer is almost full).
+static void IOVecDrop(struct iovec* iov, int iovcnt, size_t toDrop) {
+  while (toDrop > 0 && iovcnt > 0) {
+    size_t toDropHere = std::min(toDrop, iov->iov_len);
+    iov->iov_base = static_cast<char*>(iov->iov_base) + toDropHere;
+    iov->iov_len -= toDropHere;
+    toDrop -= toDropHere;
+    ++iov;
+    --iovcnt;
+  }
+}
+
+void SandboxLogError(const char* message) {
+#ifdef ANDROID
+  // This uses writev internally and appears to be async signal safe.
+  __android_log_write(ANDROID_LOG_ERROR, "Sandbox", message);
+#endif
+  static const char logPrefix[] = "Sandbox: ", logSuffix[] = "\n";
+  struct iovec iovs[3] = {
+      {const_cast<char*>(logPrefix), sizeof(logPrefix) - 1},
+      {const_cast<char*>(message), strlen(message)},
+      {const_cast<char*>(logSuffix), sizeof(logSuffix) - 1},
+  };
+  while (iovs[2].iov_len > 0) {
+    ssize_t written = HANDLE_EINTR(writev(STDERR_FILENO, iovs, 3));
+    if (written <= 0) {
+      break;
+    }
+    IOVecDrop(iovs, 3, static_cast<size_t>(written));
+  }
+}
+
+ssize_t GetLibcErrorName(char* aBuf, size_t aSize, int aErr) {
+  const char* errStr;
+
+#ifdef HAVE_STRERRORNAME_NP
+  // This is the function we'd like to have, but it's a glibc
+  // extension and present only in newer versions.
+  errStr = strerrorname_np(aErr);
+#else
+  // Otherwise, handle most of the basic / common errors with a big
+  // switch statement.
+  switch (aErr) {
+
+#  define HANDLE_ERR(x) \
+    case x:             \
+      errStr = #x;      \
+      break
+
+    // errno-base.h
+    HANDLE_ERR(EPERM);
+    HANDLE_ERR(ENOENT);
+    HANDLE_ERR(ESRCH);
+    HANDLE_ERR(EINTR);
+    HANDLE_ERR(EIO);
+    HANDLE_ERR(ENXIO);
+    HANDLE_ERR(E2BIG);
+    HANDLE_ERR(ENOEXEC);
+    HANDLE_ERR(EBADF);
+    HANDLE_ERR(ECHILD);
+    HANDLE_ERR(EAGAIN);
+    HANDLE_ERR(ENOMEM);
+    HANDLE_ERR(EACCES);
+    HANDLE_ERR(EFAULT);
+    HANDLE_ERR(ENOTBLK);
+    HANDLE_ERR(EBUSY);
+    HANDLE_ERR(EEXIST);
+    HANDLE_ERR(EXDEV);
+    HANDLE_ERR(ENODEV);
+    HANDLE_ERR(ENOTDIR);
+    HANDLE_ERR(EISDIR);
+    HANDLE_ERR(EINVAL);
+    HANDLE_ERR(ENFILE);
+    HANDLE_ERR(EMFILE);
+    HANDLE_ERR(ENOTTY);
+    HANDLE_ERR(ETXTBSY);
+    HANDLE_ERR(EFBIG);
+    HANDLE_ERR(ENOSPC);
+    HANDLE_ERR(ESPIPE);
+    HANDLE_ERR(EROFS);
+    HANDLE_ERR(EMLINK);
+    HANDLE_ERR(EPIPE);
+    HANDLE_ERR(EDOM);
+    HANDLE_ERR(ERANGE);
+
+    // selected other errors
+    HANDLE_ERR(ENAMETOOLONG);
+    HANDLE_ERR(ENOSYS);
+    HANDLE_ERR(ENOTEMPTY);
+    HANDLE_ERR(ELOOP);
+    HANDLE_ERR(ENOTSOCK);
+    HANDLE_ERR(EMSGSIZE);
+    HANDLE_ERR(ECONNRESET);
+    HANDLE_ERR(ECONNREFUSED);
+    HANDLE_ERR(EHOSTUNREACH);
+    HANDLE_ERR(ESTALE);
+
+#  undef HANDLE_ERR
+
+    default:
+      errStr = nullptr;
+  }
+#endif  // no strerrorname_np
+
+  if (errStr) {
+    return base::strings::SafeSNPrintf(aBuf, aSize, "%s", errStr);
+  }
+
+  return base::strings::SafeSNPrintf(aBuf, aSize, "error %d", aErr);
+}
+
+}  // namespace mozilla