/**
* tty_audit_add_data - Add data for TTY auditing.
*
* Audit @data of @size from @tty, if necessary.
*/
void tty_audit_add_data(struct tty_struct *tty, unsigned char *data,
size_t size, unsigned icanon)
{
struct tty_audit_buf *buf;
int major, minor;
int audit_log_tty_passwd;
unsigned long flags;
if (unlikely(size == 0))
return;
spin_lock_irqsave(¤t->sighand->siglock, flags);
audit_log_tty_passwd = current->signal->audit_tty_log_passwd;
spin_unlock_irqrestore(¤t->sighand->siglock, flags);
if (!audit_log_tty_passwd && icanon && !L_ECHO(tty))
return;
if (tty->driver->type == TTY_DRIVER_TYPE_PTY
&& tty->driver->subtype == PTY_TYPE_MASTER)
return;
buf = tty_audit_buf_get(tty, icanon);
if (!buf)
return;
mutex_lock(&buf->mutex);
major = tty->driver->major;
minor = tty->driver->minor_start + tty->index;
if (buf->major != major || buf->minor != minor
|| buf->icanon != icanon) {
tty_audit_buf_push(buf);
buf->major = major;
buf->minor = minor;
buf->icanon = icanon;
}
do {
size_t run;
run = N_TTY_BUF_SIZE - buf->valid;
if (run > size)
run = size;
memcpy(buf->data + buf->valid, data, run);
buf->valid += run;
data += run;
size -= run;
if (buf->valid == N_TTY_BUF_SIZE)
tty_audit_buf_push(buf);
} while (size != 0);
mutex_unlock(&buf->mutex);
tty_audit_buf_put(buf);
}
/**
* tty_audit_push - Push buffered data out
*
* Make sure no audit data is pending for @tty on the current process.
*/
void tty_audit_push(struct tty_struct *tty)
{
struct tty_audit_buf *buf;
unsigned long flags;
spin_lock_irqsave(¤t->sighand->siglock, flags);
if (likely(!current->signal->audit_tty)) {
spin_unlock_irqrestore(¤t->sighand->siglock, flags);
return;
}
buf = current->signal->tty_audit_buf;
if (buf)
atomic_inc(&buf->count);
spin_unlock_irqrestore(¤t->sighand->siglock, flags);
if (buf) {
int major, minor;
major = tty->driver->major;
minor = tty->driver->minor_start + tty->index;
mutex_lock(&buf->mutex);
if (buf->major == major && buf->minor == minor)
tty_audit_buf_push(buf);
mutex_unlock(&buf->mutex);
tty_audit_buf_put(buf);
}
}
/**
* tty_audit_push_current - Flush current's pending audit data
*
* Try to lock sighand and get a reference to the tty audit buffer if available.
* Flush the buffer or return an appropriate error code.
*/
int tty_audit_push_current(void)
{
struct tty_audit_buf *buf = ERR_PTR(-EPERM);
struct task_struct *tsk = current;
unsigned long flags;
if (!lock_task_sighand(tsk, &flags))
return -ESRCH;
if (tsk->signal->audit_tty) {
buf = tsk->signal->tty_audit_buf;
if (buf)
atomic_inc(&buf->count);
}
unlock_task_sighand(tsk, &flags);
/*
* Return 0 when signal->audit_tty set
* but tsk->signal->tty_audit_buf == NULL.
*/
if (!buf || IS_ERR(buf))
return PTR_ERR(buf);
mutex_lock(&buf->mutex);
tty_audit_buf_push(buf);
mutex_unlock(&buf->mutex);
tty_audit_buf_put(buf);
return 0;
}
/**
* tty_audit_tiocsti - Log TIOCSTI
*/
void tty_audit_tiocsti(struct tty_struct *tty, char ch)
{
struct tty_audit_buf *buf;
int major, minor, should_audit;
unsigned long flags;
spin_lock_irqsave(¤t->sighand->siglock, flags);
should_audit = current->signal->audit_tty;
buf = current->signal->tty_audit_buf;
if (buf)
atomic_inc(&buf->count);
spin_unlock_irqrestore(¤t->sighand->siglock, flags);
major = tty->driver->major;
minor = tty->driver->minor_start + tty->index;
if (buf) {
mutex_lock(&buf->mutex);
if (buf->major == major && buf->minor == minor)
tty_audit_buf_push(buf);
mutex_unlock(&buf->mutex);
tty_audit_buf_put(buf);
}
if (should_audit && audit_enabled) {
kuid_t auid;
unsigned int sessionid;
auid = audit_get_loginuid(current);
sessionid = audit_get_sessionid(current);
tty_audit_log("ioctl=TIOCSTI", major, minor, &ch, 1);
}
}
int tty_audit_push_task(struct task_struct *tsk, uid_t loginuid, u32 sessionid)
{
struct tty_audit_buf *buf = ERR_PTR(-EPERM);
unsigned long flags;
if (!lock_task_sighand(tsk, &flags))
return -ESRCH;
if (tsk->signal->audit_tty) {
buf = tsk->signal->tty_audit_buf;
if (buf)
atomic_inc(&buf->count);
}
unlock_task_sighand(tsk, &flags);
/*
*/
if (!buf || IS_ERR(buf))
return PTR_ERR(buf);
mutex_lock(&buf->mutex);
tty_audit_buf_push(tsk, loginuid, sessionid, buf);
mutex_unlock(&buf->mutex);
tty_audit_buf_put(buf);
return 0;
}
/**
* tty_audit_exit - Handle a task exit
*
* Make sure all buffered data is written out and deallocate the buffer.
* Only needs to be called if current->signal->tty_audit_buf != %NULL.
*/
void tty_audit_exit(void)
{
struct tty_audit_buf *buf;
buf = current->signal->tty_audit_buf;
current->signal->tty_audit_buf = NULL;
if (!buf)
return;
mutex_lock(&buf->mutex);
tty_audit_buf_push(buf);
mutex_unlock(&buf->mutex);
tty_audit_buf_put(buf);
}
/**
* tty_audit_push_task - Flush task's pending audit data
*/
void tty_audit_push_task(struct task_struct *tsk, uid_t loginuid, u32 sessionid)
{
struct tty_audit_buf *buf;
spin_lock_irq(&tsk->sighand->siglock);
buf = tsk->signal->tty_audit_buf;
if (buf)
atomic_inc(&buf->count);
spin_unlock_irq(&tsk->sighand->siglock);
if (!buf)
return;
mutex_lock(&buf->mutex);
tty_audit_buf_push(tsk, loginuid, sessionid, buf);
mutex_unlock(&buf->mutex);
tty_audit_buf_put(buf);
}
/**
* tty_audit_buf_push_current - Push buffered data out
*
* Generate an audit message from the contents of @buf, which is owned by
* the current task. @buf->mutex must be locked.
*/
static void tty_audit_buf_push_current(struct tty_audit_buf *buf)
{
uid_t auid = audit_get_loginuid(current);
unsigned int sessionid = audit_get_sessionid(current);
tty_audit_buf_push(current, auid, sessionid, buf);
}
