tequilaOS/platform_system_core
2
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity

Merge "logd: enforce policy integrity"

Browse source
This commit is contained in:
Sami Tolvanen 2016-02-16 21:52:13 +00:00 committed by Gerrit Code Review
commit d1ac932330
5 changed files with 95 additions and 22 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

4
logd/Android.mk
View file

@ -42,6 +42,10 @@ event_flag := -DAUDITD_LOG_TAG=1003 -DLOGD_LOG_TAG=1004
LOCAL_CFLAGS := -Werror $(event_flag)
ifeq ($(TARGET_BUILD_VARIANT),user)
LOCAL_CFLAGS += -DAUDITD_ENFORCE_INTEGRITY=true
endif
include $(BUILD_EXECUTABLE)
include $(call first-makefiles-under,$(LOCAL_PATH))

74
logd/LogAudit.cpp
View file

@ -24,6 +24,7 @@
#include <sys/uio.h>
#include <syslog.h>
#include <cutils/properties.h>
#include <log/logger.h>
#include <private/android_filesystem_config.h>
#include <private/android_logger.h>
@ -32,6 +33,10 @@
#include "LogAudit.h"
#include "LogKlog.h"
#ifndef AUDITD_ENFORCE_INTEGRITY
#define AUDITD_ENFORCE_INTEGRITY false
#endif
#define KMSG_PRIORITY(PRI) \
'<', \
'0' + LOG_MAKEPRI(LOG_AUTH, LOG_PRI(PRI)) / 10, \
@ -43,11 +48,10 @@ LogAudit::LogAudit(LogBuffer *buf, LogReader *reader, int fdDmesg) :
logbuf(buf),
reader(reader),
fdDmesg(fdDmesg),
policyLoaded(false),
rebootToSafeMode(false),
initialized(false) {
static const char auditd_message[] = { KMSG_PRIORITY(LOG_INFO),
'l', 'o', 'g', 'd', '.', 'a', 'u', 'd', 'i', 't', 'd', ':',
' ', 's', 't', 'a', 'r', 't', '\n' };
write(fdDmesg, auditd_message, sizeof(auditd_message));
logToDmesg("start");
}
bool LogAudit::onDataAvailable(SocketClient *cli) {
@ -73,6 +77,46 @@ bool LogAudit::onDataAvailable(SocketClient *cli) {
return true;
}
void LogAudit::logToDmesg(const std::string& str)
{
static const char prefix[] = { KMSG_PRIORITY(LOG_INFO),
'l', 'o', 'g', 'd', '.', 'a', 'u', 'd', 'i', 't', 'd', ':',
' ', '\0' };
std::string message = prefix + str + "\n";
write(fdDmesg, message.c_str(), message.length());
}
std::string LogAudit::getProperty(const std::string& name)
{
char value[PROP_VALUE_MAX] = {0};
property_get(name.c_str(), value, "");
return value;
}
void LogAudit::enforceIntegrity() {
if (!AUDITD_ENFORCE_INTEGRITY) {
logToDmesg("integrity enforcement suppressed; not rebooting");
} else if (rebootToSafeMode) {
if (getProperty("persist.sys.safemode") == "1") {
logToDmesg("integrity enforcement suppressed; in safe mode");
return;
}
logToDmesg("enforcing integrity; rebooting to safe mode");
property_set("persist.sys.safemode", "1");
std::string buildDate = getProperty("ro.build.date.utc");
if (!buildDate.empty()) {
property_set("persist.sys.audit_safemode", buildDate.c_str());
}
property_set("sys.powerctl", "reboot");
} else {
logToDmesg("enforcing integrity: rebooting to recovery");
property_set("sys.powerctl", "reboot,recovery");
}
}
int LogAudit::logPrint(const char *fmt, ...) {
if (fmt == NULL) {
return -EINVAL;
@ -94,7 +138,27 @@ int LogAudit::logPrint(const char *fmt, ...) {
memmove(cp, cp + 1, strlen(cp + 1) + 1);
}
bool info = strstr(str, " permissive=1") || strstr(str, " policy loaded ");
bool loaded = strstr(str, " policy loaded ");
if (loaded) {
if (policyLoaded) {
// SELinux policy changes are not allowed
enforceIntegrity();
} else {
logToDmesg("policy loaded");
policyLoaded = true;
}
}
bool permissive = strstr(str, " enforcing=0") ||
strstr(str, " permissive=1");
if (permissive) {
// SELinux in permissive mode is not allowed
enforceIntegrity();
}
bool info = loaded || permissive;
if ((fdDmesg >= 0) && initialized) {
struct iovec iov[3];
static const char log_info[] = { KMSG_PRIORITY(LOG_INFO) };

6
logd/LogAudit.h
View file

@ -24,12 +24,15 @@ class LogAudit : public SocketListener {
LogBuffer *logbuf;
LogReader *reader;
int fdDmesg;
bool policyLoaded;
bool rebootToSafeMode;
bool initialized;
public:
LogAudit(LogBuffer *buf, LogReader *reader, int fdDmesg);
int log(char *buf, size_t len);
bool isMonotonic() { return logbuf->isMonotonic(); }
void allowSafeMode(bool allow = true) { rebootToSafeMode = allow; }
protected:
virtual bool onDataAvailable(SocketClient *cli);
@ -38,6 +41,9 @@ private:
static int getLogSocket();
int logPrint(const char *fmt, ...)
__attribute__ ((__format__ (__printf__, 2, 3)));
void logToDmesg(const std::string& str);
std::string getProperty(const std::string& name);
void enforceIntegrity();
};
#endif

1
logd/README.property
View file

@ -1,7 +1,6 @@
The properties that logd responds to are:
name type default description
ro.logd.auditd bool true Enable selinux audit daemon
ro.logd.auditd.dmesg bool true selinux audit messages duplicated and
sent on to dmesg log
persist.logd.security bool false Enable security buffer.

32
logd/main.cpp
View file

@ -245,6 +245,7 @@ static char *name;
static sem_t reinit;
static bool reinit_running = false;
static LogBuffer *logBuf = NULL;
static LogAudit *logAudit = NULL;
static bool package_list_parser_cb(pkg_info *info, void * /* userdata */) {
@ -292,6 +293,10 @@ static void *reinit_thread_start(void * /*obj*/) {
logBuf->init();
logBuf->initPrune(NULL);
}
if (logAudit) {
logAudit->allowSafeMode();
}
}
return NULL;
@ -512,25 +517,19 @@ int main(int argc, char *argv[]) {
// initiated log messages. New log entries are added to LogBuffer
// and LogReader is notified to send updates to connected clients.
bool auditd = property_get_bool("logd.auditd",
BOOL_DEFAULT_TRUE |
BOOL_DEFAULT_FLAG_PERSIST);
LogAudit *al = NULL;
if (auditd) {
al = new LogAudit(logBuf, reader,
property_get_bool("logd.auditd.dmesg",
BOOL_DEFAULT_TRUE |
BOOL_DEFAULT_FLAG_PERSIST)
? fdDmesg
: -1);
}
logAudit = new LogAudit(logBuf, reader,
property_get_bool("logd.auditd.dmesg",
BOOL_DEFAULT_TRUE |
BOOL_DEFAULT_FLAG_PERSIST)
? fdDmesg
: -1);
LogKlog *kl = NULL;
if (klogd) {
kl = new LogKlog(logBuf, reader, fdDmesg, fdPmesg, al != NULL);
kl = new LogKlog(logBuf, reader, fdDmesg, fdPmesg, logAudit != NULL);
}
readDmesg(al, kl);
readDmesg(logAudit, kl);
// failure is an option ... messages are in dmesg (required by standard)
@ -538,8 +537,9 @@ int main(int argc, char *argv[]) {
delete kl;
}
if (al && al->startListener()) {
delete al;
if (logAudit && logAudit->startListener()) {
delete logAudit;
logAudit = NULL;
}
TEMP_FAILURE_RETRY(pause());