1 files changed, 75 insertions, 0 deletions
diff --git a/sandbox/linux/seccomp/mmap.cc b/sandbox/linux/seccomp/mmap.cc
new file mode 100644
index 0000000..700da91
--- /dev/null
+++ b/sandbox/linux/seccomp/mmap.cc
@@ -0,0 +1,75 @@
+// Copyright (c) 2010 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "debug.h"
+#include "sandbox_impl.h"
+
+namespace playground {
+
+void* Sandbox::sandbox_mmap(void *start, size_t length, int prot, int flags,
+                          int fd, off_t offset) {
+  long long tm;
+  Debug::syscall(&tm, __NR_mmap, "Executing handler");
+  struct {
+    int       sysnum;
+    long long cookie;
+    MMap      mmap_req;
+  } __attribute__((packed)) request;
+  request.sysnum          = __NR_MMAP;
+  request.cookie          = cookie();
+  request.mmap_req.start  = start;
+  request.mmap_req.length = length;
+  request.mmap_req.prot   = prot;
+  request.mmap_req.flags  = flags;
+  request.mmap_req.fd     = fd;
+  request.mmap_req.offset = offset;
+
+  void* rc;
+  SysCalls sys;
+  if (write(sys, processFdPub(), &request, sizeof(request)) !=
+      sizeof(request) ||
+      read(sys, threadFdPub(), &rc, sizeof(rc)) != sizeof(rc)) {
+    die("Failed to forward mmap() request [sandbox]");
+  }
+  Debug::elapsed(tm, __NR_mmap);
+  return rc;
+}
+
+bool Sandbox::process_mmap(int parentMapsFd, int sandboxFd, int threadFdPub,
+                           int threadFd, SecureMem::Args* mem) {
+  // Read request
+  SysCalls sys;
+  MMap mmap_req;
+  if (read(sys, sandboxFd, &mmap_req, sizeof(mmap_req)) != sizeof(mmap_req)) {
+    die("Failed to read parameters for mmap() [process]");
+  }
+
+  if (mmap_req.flags & MAP_FIXED) {
+    // Cannot map a memory area that was part of the original memory mappings.
+    void *stop = reinterpret_cast<void *>(
+        (char *)mmap_req.start + mmap_req.length);
+    ProtectedMap::const_iterator iter = protectedMap_.lower_bound(
+        (void *)mmap_req.start);
+    if (iter != protectedMap_.begin()) {
+      --iter;
+    }
+    for (; iter != protectedMap_.end() && iter->first < stop; ++iter) {
+      if (mmap_req.start < reinterpret_cast<void *>(
+              reinterpret_cast<char *>(iter->first) + iter->second) &&
+          stop > iter->first) {
+        int rc = -EINVAL;
+        SecureMem::abandonSystemCall(threadFd, rc);
+        return false;
+      }
+    }
+  }
+
+  // All other mmap() requests are OK
+  SecureMem::sendSystemCall(threadFdPub, false, -1, mem, __NR_MMAP,
+                            mmap_req.start, mmap_req.length, mmap_req.prot,
+                            mmap_req.flags, mmap_req.fd, mmap_req.offset);
+  return true;
+}
+
+} // namespace