Pull seccomp-sandbox in via DEPS rather than using an in-tree copy...

sandbox/linux/seccomp/access.cc

-// 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 {
-
-long Sandbox::sandbox_access(const char *pathname, int mode) {
-  long long tm;
-  Debug::syscall(&tm, __NR_access, "Executing handler");
-  size_t len                      = strlen(pathname);
-  struct Request {
-    int       sysnum;
-    long long cookie;
-    Access    access_req;
-    char      pathname[0];
-  } __attribute__((packed)) *request;
-  char data[sizeof(struct Request) + len];
-  request                         = reinterpret_cast<struct Request*>(data);
-  request->sysnum                 = __NR_access;
-  request->cookie                 = cookie();
-  request->access_req.path_length = len;
-  request->access_req.mode        = mode;
-  memcpy(request->pathname, pathname, len);
-
-  long rc;
-  SysCalls sys;
-  if (write(sys, processFdPub(), request, sizeof(data)) != (int)sizeof(data) ||
-      read(sys, threadFdPub(), &rc, sizeof(rc)) != sizeof(rc)) {
-    die("Failed to forward access() request [sandbox]");
-  }
-  Debug::elapsed(tm, __NR_access);
-  return rc;
-}
-
-bool Sandbox::process_access(int parentMapsFd, int sandboxFd, int threadFdPub,
-                           int threadFd, SecureMem::Args* mem) {
-  // Read request
-  SysCalls sys;
-  Access access_req;
-  if (read(sys, sandboxFd, &access_req, sizeof(access_req)) !=
-      sizeof(access_req)) {
- read_parm_failed:
-    die("Failed to read parameters for access() [process]");
-  }
-  int   rc                    = -ENAMETOOLONG;
-  if (access_req.path_length >= sizeof(mem->pathname)) {
-    char buf[32];
-    while (access_req.path_length > 0) {
-      size_t len              = access_req.path_length > sizeof(buf) ?
-                                sizeof(buf) : access_req.path_length;
-      ssize_t i               = read(sys, sandboxFd, buf, len);
-      if (i <= 0) {
-        goto read_parm_failed;
-      }
-      access_req.path_length -= i;
-    }
-    if (write(sys, threadFd, &rc, sizeof(rc)) != sizeof(rc)) {
-      die("Failed to return data from access() [process]");
-    }
-    return false;
-  }
-
-  if (!g_policy.allow_file_namespace) {
-    // After locking the mutex, we can no longer abandon the system call. So,
-    // perform checks before clobbering the securely shared memory.
-    char tmp[access_req.path_length];
-    if (read(sys, sandboxFd, tmp, access_req.path_length) !=
-        (ssize_t)access_req.path_length) {
-      goto read_parm_failed;
-    }
-    Debug::message(("Denying access to \"" + std::string(tmp) + "\"").c_str());
-    SecureMem::abandonSystemCall(threadFd, -EACCES);
-    return false;
-  }
-
-  SecureMem::lockSystemCall(parentMapsFd, mem);
-  if (read(sys, sandboxFd, mem->pathname, access_req.path_length) !=
-      (ssize_t)access_req.path_length) {
-    goto read_parm_failed;
-  }
-  mem->pathname[access_req.path_length] = '\000';
-
-  // TODO(markus): Implement sandboxing policy
-  Debug::message(("Allowing access to \"" + std::string(mem->pathname) +
-                  "\"").c_str());
-
-  // Tell trusted thread to access the file.
-  SecureMem::sendSystemCall(threadFdPub, true, parentMapsFd, mem, __NR_access,
-                            mem->pathname - (char*)mem + (char*)mem->self,
-                            access_req.mode);
-  return true;
-}
-
-} // namespace