1 files changed, 88 insertions, 0 deletions
diff --git a/security/sandbox/linux/SandboxReporterClient.cpp b/security/sandbox/linux/SandboxReporterClient.cpp
new file mode 100644
index 0000000000..6359c2cb9a
--- /dev/null
+++ b/security/sandbox/linux/SandboxReporterClient.cpp
@@ -0,0 +1,88 @@
+/* -*- 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 "SandboxReporterClient.h"
+#include "SandboxLogging.h"
+
+#include <errno.h>
+#include <signal.h>
+#include <sys/socket.h>
+#include <sys/syscall.h>
+#include <sys/types.h>
+#include <time.h>
+
+#include "mozilla/Assertions.h"
+#include "mozilla/PodOperations.h"
+#include "prenv.h"
+#include "sandbox/linux/bpf_dsl/seccomp_macros.h"
+#ifdef ANDROID
+#  include "sandbox/linux/system_headers/linux_ucontext.h"
+#else
+#  include <ucontext.h>
+#endif
+
+namespace mozilla {
+
+SandboxReporterClient::SandboxReporterClient(SandboxReport::ProcType aProcType,
+                                             int aFd)
+    : mProcType(aProcType), mFd(aFd) {
+  // Unfortunately, there isn't a good way to check that the fd is a
+  // socket connected to the right thing without attempting some kind
+  // of in-band handshake.  However, the crash reporter (which also
+  // uses a "magic number" fd) doesn't do any kind of checking either,
+  // so it's probably okay to skip it here.
+}
+
+SandboxReporterClient::SandboxReporterClient(SandboxReport::ProcType aProcType)
+    : SandboxReporterClient(aProcType, kSandboxReporterFileDesc) {
+  MOZ_RELEASE_ASSERT(PR_GetEnv("MOZ_SANDBOXED") != nullptr);
+}
+
+SandboxReport SandboxReporterClient::MakeReport(const void* aContext) {
+  SandboxReport report;
+  const auto ctx = static_cast<const ucontext_t*>(aContext);
+
+  // Zero the entire struct; some memory safety analyses care about
+  // sending uninitialized alignment padding to another process.
+  PodZero(&report);
+
+  clock_gettime(CLOCK_MONOTONIC_COARSE, &report.mTime);
+  report.mPid = getpid();
+  report.mTid = syscall(__NR_gettid);
+  report.mProcType = mProcType;
+  report.mSyscall = SECCOMP_SYSCALL(ctx);
+  report.mArgs[0] = SECCOMP_PARM1(ctx);
+  report.mArgs[1] = SECCOMP_PARM2(ctx);
+  report.mArgs[2] = SECCOMP_PARM3(ctx);
+  report.mArgs[3] = SECCOMP_PARM4(ctx);
+  report.mArgs[4] = SECCOMP_PARM5(ctx);
+  report.mArgs[5] = SECCOMP_PARM6(ctx);
+  // Named Return Value Optimization allows the compiler to optimize
+  // out the copy here (and the one in MakeReportAndSend).
+  return report;
+}
+
+void SandboxReporterClient::SendReport(const SandboxReport& aReport) {
+  // The "common" seccomp-bpf policy allows sendmsg but not send(to),
+  // so just use sendmsg even though send would suffice for this.
+  struct iovec iov;
+  struct msghdr msg;
+
+  iov.iov_base = const_cast<void*>(static_cast<const void*>(&aReport));
+  iov.iov_len = sizeof(SandboxReport);
+  PodZero(&msg);
+  msg.msg_iov = &iov;
+  msg.msg_iovlen = 1;
+
+  const auto sent = sendmsg(mFd, &msg, MSG_NOSIGNAL);
+
+  if (sent != sizeof(SandboxReport)) {
+    MOZ_DIAGNOSTIC_ASSERT(sent == -1);
+    SANDBOX_LOG_ERRNO("Failed to report rejected syscall");
+  }
+}
+
+}  // namespace mozilla