gecko-dev/security/sandbox/linux/SandboxReporterClient.cpp

97 строки
3.0 KiB
C++

/* -*- 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_ERROR("Failed to report rejected syscall: %s",
strerror(errno));
}
}
} // namespace mozilla