diff options
Diffstat (limited to 'drivers/char/tty_audit.c')
| -rw-r--r-- | drivers/char/tty_audit.c | 352 |
1 files changed, 0 insertions, 352 deletions
diff --git a/drivers/char/tty_audit.c b/drivers/char/tty_audit.c deleted file mode 100644 index 7722466e052..00000000000 --- a/drivers/char/tty_audit.c +++ /dev/null @@ -1,352 +0,0 @@ -/* - * Creating audit events from TTY input. - * - * Copyright (C) 2007 Red Hat, Inc. All rights reserved. This copyrighted - * material is made available to anyone wishing to use, modify, copy, or - * redistribute it subject to the terms and conditions of the GNU General - * Public License v.2. - * - * Authors: Miloslav Trmac <mitr@redhat.com> - */ - -#include <linux/audit.h> -#include <linux/file.h> -#include <linux/tty.h> - -struct tty_audit_buf { - atomic_t count; - struct mutex mutex; /* Protects all data below */ - int major, minor; /* The TTY which the data is from */ - unsigned icanon:1; - size_t valid; - unsigned char *data; /* Allocated size N_TTY_BUF_SIZE */ -}; - -static struct tty_audit_buf *tty_audit_buf_alloc(int major, int minor, - int icanon) -{ - struct tty_audit_buf *buf; - - buf = kmalloc(sizeof(*buf), GFP_KERNEL); - if (!buf) - goto err; - if (PAGE_SIZE != N_TTY_BUF_SIZE) - buf->data = kmalloc(N_TTY_BUF_SIZE, GFP_KERNEL); - else - buf->data = (unsigned char *)__get_free_page(GFP_KERNEL); - if (!buf->data) - goto err_buf; - atomic_set(&buf->count, 1); - mutex_init(&buf->mutex); - buf->major = major; - buf->minor = minor; - buf->icanon = icanon; - buf->valid = 0; - return buf; - -err_buf: - kfree(buf); -err: - return NULL; -} - -static void tty_audit_buf_free(struct tty_audit_buf *buf) -{ - WARN_ON(buf->valid != 0); - if (PAGE_SIZE != N_TTY_BUF_SIZE) - kfree(buf->data); - else - free_page((unsigned long)buf->data); - kfree(buf); -} - -static void tty_audit_buf_put(struct tty_audit_buf *buf) -{ - if (atomic_dec_and_test(&buf->count)) - tty_audit_buf_free(buf); -} - -/** - * tty_audit_buf_push - Push buffered data out - * - * Generate an audit message from the contents of @buf, which is owned by - * @tsk with @loginuid. @buf->mutex must be locked. - */ -static void tty_audit_buf_push(struct task_struct *tsk, uid_t loginuid, - unsigned int sessionid, - struct tty_audit_buf *buf) -{ - struct audit_buffer *ab; - - if (buf->valid == 0) - return; - if (audit_enabled == 0) - return; - ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_TTY); - if (ab) { - char name[sizeof(tsk->comm)]; - - audit_log_format(ab, "tty pid=%u uid=%u auid=%u ses=%u " - "major=%d minor=%d comm=", tsk->pid, tsk->uid, - loginuid, sessionid, buf->major, buf->minor); - get_task_comm(name, tsk); - audit_log_untrustedstring(ab, name); - audit_log_format(ab, " data="); - audit_log_n_untrustedstring(ab, buf->valid, buf->data); - audit_log_end(ab); - } - buf->valid = 0; -} - -/** - * 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); -} - -/** - * 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; - - spin_lock_irq(¤t->sighand->siglock); - buf = current->signal->tty_audit_buf; - current->signal->tty_audit_buf = NULL; - spin_unlock_irq(¤t->sighand->siglock); - if (!buf) - return; - - mutex_lock(&buf->mutex); - tty_audit_buf_push_current(buf); - mutex_unlock(&buf->mutex); - - tty_audit_buf_put(buf); -} - -/** - * tty_audit_fork - Copy TTY audit state for a new task - * - * Set up TTY audit state in @sig from current. @sig needs no locking. - */ -void tty_audit_fork(struct signal_struct *sig) -{ - spin_lock_irq(¤t->sighand->siglock); - sig->audit_tty = current->signal->audit_tty; - spin_unlock_irq(¤t->sighand->siglock); - sig->tty_audit_buf = NULL; -} - -/** - * tty_audit_push_task - Flush task's pending audit data - */ -void tty_audit_push_task(struct task_struct *tsk, uid_t loginuid) -{ - struct tty_audit_buf *buf; - /* FIXME I think this is correct. Check against netlink once that is - * I really need to read this code more closely. But that's for - * another patch. - */ - unsigned int sessionid = audit_get_sessionid(tsk); - - 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_get - Get an audit buffer. - * - * Get an audit buffer for @tty, allocate it if necessary. Return %NULL - * if TTY auditing is disabled or out of memory. Otherwise, return a new - * reference to the buffer. - */ -static struct tty_audit_buf *tty_audit_buf_get(struct tty_struct *tty) -{ - struct tty_audit_buf *buf, *buf2; - - buf = NULL; - buf2 = NULL; - spin_lock_irq(¤t->sighand->siglock); - if (likely(!current->signal->audit_tty)) - goto out; - buf = current->signal->tty_audit_buf; - if (buf) { - atomic_inc(&buf->count); - goto out; - } - spin_unlock_irq(¤t->sighand->siglock); - - buf2 = tty_audit_buf_alloc(tty->driver->major, - tty->driver->minor_start + tty->index, - tty->icanon); - if (buf2 == NULL) { - audit_log_lost("out of memory in TTY auditing"); - return NULL; - } - - spin_lock_irq(¤t->sighand->siglock); - if (!current->signal->audit_tty) - goto out; - buf = current->signal->tty_audit_buf; - if (!buf) { - current->signal->tty_audit_buf = buf2; - buf = buf2; - buf2 = NULL; - } - atomic_inc(&buf->count); - /* Fall through */ - out: - spin_unlock_irq(¤t->sighand->siglock); - if (buf2) - tty_audit_buf_free(buf2); - return buf; -} - -/** - * 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) -{ - struct tty_audit_buf *buf; - int major, minor; - - if (unlikely(size == 0)) - return; - - buf = tty_audit_buf_get(tty); - 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 != tty->icanon) { - tty_audit_buf_push_current(buf); - buf->major = major; - buf->minor = minor; - buf->icanon = tty->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_current(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; - - spin_lock_irq(¤t->sighand->siglock); - if (likely(!current->signal->audit_tty)) { - spin_unlock_irq(¤t->sighand->siglock); - return; - } - buf = current->signal->tty_audit_buf; - if (buf) - atomic_inc(&buf->count); - spin_unlock_irq(¤t->sighand->siglock); - - 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_current(buf); - mutex_unlock(&buf->mutex); - tty_audit_buf_put(buf); - } -} - -/** - * tty_audit_opening - A TTY is being opened. - * - * As a special hack, tasks that close all their TTYs and open new ones - * are assumed to be system daemons (e.g. getty) and auditing is - * automatically disabled for them. - */ -void tty_audit_opening(void) -{ - int disable; - - disable = 1; - spin_lock_irq(¤t->sighand->siglock); - if (current->signal->audit_tty == 0) - disable = 0; - spin_unlock_irq(¤t->sighand->siglock); - if (!disable) - return; - - task_lock(current); - if (current->files) { - struct fdtable *fdt; - unsigned i; - - /* - * We don't take a ref to the file, so we must hold ->file_lock - * instead. - */ - spin_lock(¤t->files->file_lock); - fdt = files_fdtable(current->files); - for (i = 0; i < fdt->max_fds; i++) { - struct file *filp; - - filp = fcheck_files(current->files, i); - if (filp && is_tty(filp)) { - disable = 0; - break; - } - } - spin_unlock(¤t->files->file_lock); - } - task_unlock(current); - if (!disable) - return; - - spin_lock_irq(¤t->sighand->siglock); - current->signal->audit_tty = 0; - spin_unlock_irq(¤t->sighand->siglock); -} |