gecko-dev/widget/cocoa/nsSandboxViolationSink.mm

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/* -*- Mode: C++; tab-width: 20; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* 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 "nsSandboxViolationSink.h"
#include <unistd.h>
#include <time.h>
#include <asl.h>
#include <dispatch/dispatch.h>
#include <notify.h>
#include "nsCocoaDebugUtils.h"
#include "mozilla/Preferences.h"
int nsSandboxViolationSink::mNotifyToken = 0;
uint64_t nsSandboxViolationSink::mLastMsgReceived = 0;
void
nsSandboxViolationSink::Start()
{
if (mNotifyToken) {
return;
}
notify_register_dispatch(SANDBOX_VIOLATION_NOTIFICATION_NAME,
&mNotifyToken,
dispatch_queue_create(SANDBOX_VIOLATION_QUEUE_NAME,
DISPATCH_QUEUE_SERIAL),
^(int token) { ViolationHandler(); });
}
void
nsSandboxViolationSink::Stop()
{
if (!mNotifyToken) {
return;
}
notify_cancel(mNotifyToken);
mNotifyToken = 0;
}
// We need to query syslogd to find out what violations occurred, and whether
// they were "ours". We can use the Apple System Log facility to do this.
// Besides calling notify_post("com.apple.sandbox.violation.*"), Apple's
// sandboxd also reports all sandbox violations (sent to it by the Sandbox
// kernel extension) to syslogd, which stores them and makes them viewable
// in the system console. This is the database we query.
// ViolationHandler() is always called on its own secondary thread. This
// makes it unlikely it will interfere with other browser activity.
void
nsSandboxViolationSink::ViolationHandler()
{
aslmsg query = asl_new(ASL_TYPE_QUERY);
asl_set_query(query, ASL_KEY_FACILITY, "com.apple.sandbox",
ASL_QUERY_OP_EQUAL);
// Only get reports that were generated very recently.
char query_time[30] = {0};
snprintf(query_time, sizeof(query_time), "%li", time(NULL) - 2);
asl_set_query(query, ASL_KEY_TIME, query_time,
ASL_QUERY_OP_NUMERIC | ASL_QUERY_OP_GREATER_EQUAL);
// This code is easier to test if we don't just track "our" violations,
// which are (normally) few and far between. For example (for the time
// being at least) four appleeventsd sandbox violations happen every time
// we start the browser in e10s mode. But it makes sense to default to
// only tracking "our" violations.
if (mozilla::Preferences::GetBool(
"security.sandbox.mac.track.violations.oursonly", true)) {
// This makes each of our processes log its own violations. It might
// be better to make the chrome process log all the other processes'
// violations.
char query_pid[20] = {0};
snprintf(query_pid, sizeof(query_pid), "%u", getpid());
asl_set_query(query, ASL_KEY_REF_PID, query_pid, ASL_QUERY_OP_EQUAL);
}
aslresponse response = asl_search(nullptr, query);
// Each time ViolationHandler() is called we grab as many messages as are
// available. Otherwise we might not get them all.
if (response) {
while (true) {
aslmsg hit = nullptr;
aslmsg found = nullptr;
const char* id_str;
while ((hit = aslresponse_next(response))) {
// Record the message id to avoid logging the same violation more
// than once.
id_str = asl_get(hit, ASL_KEY_MSG_ID);
uint64_t id_val = atoll(id_str);
if (id_val <= mLastMsgReceived) {
continue;
}
mLastMsgReceived = id_val;
found = hit;
break;
}
if (!found) {
break;
}
const char* pid_str = asl_get(found, ASL_KEY_REF_PID);
const char* message_str = asl_get(found, ASL_KEY_MSG);
nsCocoaDebugUtils::DebugLog("nsSandboxViolationSink::ViolationHandler(): id %s, pid %s, message %s",
id_str, pid_str, message_str);
}
aslresponse_free(response);
}
}