path: root/kernel/power/tuxonice_userui.c

/*
 * kernel/power/user_ui.c
 *
 * Copyright (C) 2005-2007 Bernard Blackham
 * Copyright (C) 2002-2015 Nigel Cunningham (nigel at nigelcunningham com au)
 *
 * This file is released under the GPLv2.
 *
 * Routines for TuxOnIce's user interface.
 *
 * The user interface code talks to a userspace program via a
 * netlink socket.
 *
 * The kernel side:
 * - starts the userui program;
 * - sends text messages and progress bar status;
 *
 * The user space side:
 * - passes messages regarding user requests (abort, toggle reboot etc)
 *
 */

#define __KERNEL_SYSCALLS__

#include <linux/suspend.h>
#include <linux/freezer.h>
#include <linux/console.h>
#include <linux/ctype.h>
#include <linux/tty.h>
#include <linux/vt_kern.h>
#include <linux/reboot.h>
#include <linux/security.h>
#include <linux/syscalls.h>
#include <linux/vt.h>

#include "tuxonice_sysfs.h"
#include "tuxonice_modules.h"
#include "tuxonice.h"
#include "tuxonice_ui.h"
#include "tuxonice_netlink.h"
#include "tuxonice_power_off.h"

static char local_printf_buf[1024];        /* Same as printk - should be safe */

static struct user_helper_data ui_helper_data;
static struct toi_module_ops userui_ops;
static int orig_kmsg;

static char lastheader[512];
static int lastheader_message_len;
static int ui_helper_changed; /* Used at resume-time so don't overwrite value
                                set from initrd/ramfs. */

/* Number of distinct progress amounts that userspace can display */
static int progress_granularity = 30;

static DECLARE_WAIT_QUEUE_HEAD(userui_wait_for_key);
static int userui_wait_should_wake;

#define toi_stop_waiting_for_userui_key() \
{ \
        userui_wait_should_wake = true; \
        wake_up_interruptible(&userui_wait_for_key); \
}

/**
 * ui_nl_set_state - Update toi_action based on a message from userui.
 *
 * @n: The bit (1 << bit) to set.
 */
static void ui_nl_set_state(int n)
{
        /* Only let them change certain settings */
        static const u32 toi_action_mask =
                (1 << TOI_REBOOT) | (1 << TOI_PAUSE) |
                (1 << TOI_LOGALL) |
                (1 << TOI_SINGLESTEP) |
                (1 << TOI_PAUSE_NEAR_PAGESET_END);
        static unsigned long new_action;

        new_action = (toi_bkd.toi_action & (~toi_action_mask)) |
                (n & toi_action_mask);

        printk(KERN_DEBUG "n is %x. Action flags being changed from %lx "
                        "to %lx.", n, toi_bkd.toi_action, new_action);
        toi_bkd.toi_action = new_action;

        if (!test_action_state(TOI_PAUSE) &&
                        !test_action_state(TOI_SINGLESTEP))
                toi_stop_waiting_for_userui_key();
}

/**
 * userui_post_atomic_restore - Tell userui that atomic restore just happened.
 *
 * Tell userui that atomic restore just occured, so that it can do things like
 * redrawing the screen, re-getting settings and so on.
 */
static void userui_post_atomic_restore(struct toi_boot_kernel_data *bkd)
{
        toi_send_netlink_message(&ui_helper_data,
                        USERUI_MSG_POST_ATOMIC_RESTORE, NULL, 0);
}

/**
 * userui_storage_needed - Report how much memory in image header is needed.
 */
static int userui_storage_needed(void)
{
        return sizeof(ui_helper_data.program) + 1 + sizeof(int);
}

/**
 * userui_save_config_info - Fill buffer with config info for image header.
 *
 * @buf: Buffer into which to put the config info we want to save.
 */
static int userui_save_config_info(char *buf)
{
        *((int *) buf) = progress_granularity;
        memcpy(buf + sizeof(int), ui_helper_data.program,
                        sizeof(ui_helper_data.program));
        return sizeof(ui_helper_data.program) + sizeof(int) + 1;
}

/**
 * userui_load_config_info - Restore config info from buffer.
 *
 * @buf: Buffer containing header info loaded.
 * @size: Size of data loaded for this module.
 */
static void userui_load_config_info(char *buf, int size)
{
        progress_granularity = *((int *) buf);
        size -= sizeof(int);

        /* Don't load the saved path if one has already been set */
        if (ui_helper_changed)
                return;

        if (size > sizeof(ui_helper_data.program))
                size = sizeof(ui_helper_data.program);

        memcpy(ui_helper_data.program, buf + sizeof(int), size);
        ui_helper_data.program[sizeof(ui_helper_data.program)-1] = '\0';
}

/**
 * set_ui_program_set: Record that userui program was changed.
 *
 * Side effect routine for when the userui program is set. In an initrd or
 * ramfs, the user may set a location for the userui program. If this happens,
 * we don't want to reload the value that was saved in the image header. This
 * routine allows us to flag that we shouldn't restore the program name from
 * the image header.
 */
static void set_ui_program_set(void)
{
        ui_helper_changed = 1;
}

/**
 * userui_memory_needed - Tell core how much memory to reserve for us.
 */
static int userui_memory_needed(void)
{
        /* ball park figure of 128 pages */
        return 128 * PAGE_SIZE;
}

/**
 * userui_update_status - Update the progress bar and (if on) in-bar message.
 *
 * @value: Current progress percentage numerator.
 * @maximum: Current progress percentage denominator.
 * @fmt: Message to be displayed in the middle of the progress bar.
 *
 * Note that a NULL message does not mean that any previous message is erased!
 * For that, you need toi_prepare_status with clearbar on.
 *
 * Returns an unsigned long, being the next numerator (as determined by the
 * maximum and progress granularity) where status needs to be updated.
 * This is to reduce unnecessary calls to update_status.
 */
static u32 userui_update_status(u32 value, u32 maximum, const char *fmt, ...)
{
        static u32 last_step = 9999;
        struct userui_msg_params msg;
        u32 this_step, next_update;
        int bitshift;

        if (ui_helper_data.pid == -1)
                return 0;

        if ((!maximum) || (!progress_granularity))
                return maximum;

        if (value < 0)
                value = 0;

        if (value > maximum)
                value = maximum;

        /* Try to avoid math problems - we can't do 64 bit math here
         * (and shouldn't need it - anyone got screen resolution
         * of 65536 pixels or more?) */
        bitshift = fls(maximum) - 16;
        if (bitshift > 0) {
                u32 temp_maximum = maximum >> bitshift;
                u32 temp_value = value >> bitshift;
                this_step = (u32)
                        (temp_value * progress_granularity / temp_maximum);
                next_update = (((this_step + 1) * temp_maximum /
                                        progress_granularity) + 1) << bitshift;
        } else {
                this_step = (u32) (value * progress_granularity / maximum);
                next_update = ((this_step + 1) * maximum /
                                progress_granularity) + 1;
        }

        if (this_step == last_step)
                return next_update;

        memset(&msg, 0, sizeof(msg));

        msg.a = this_step;
        msg.b = progress_granularity;

        if (fmt) {
                va_list args;
                va_start(args, fmt);
                vsnprintf(msg.text, sizeof(msg.text), fmt, args);
                va_end(args);
                msg.text[sizeof(msg.text)-1] = '\0';
        }

        toi_send_netlink_message(&ui_helper_data, USERUI_MSG_PROGRESS,
                        &msg, sizeof(msg));
        last_step = this_step;

        return next_update;
}

/**
 * userui_message - Display a message without necessarily logging it.
 *
 * @section: Type of message. Messages can be filtered by type.
 * @level: Degree of importance of the message. Lower values = higher priority.
 * @normally_logged: Whether logged even if log_everything is off.
 * @fmt: Message (and parameters).
 *
 * This function is intended to do the same job as printk, but without normally
 * logging what is printed. The point is to be able to get debugging info on
 * screen without filling the logs with "1/534. ^M 2/534^M. 3/534^M"
 *
 * It may be called from an interrupt context - can't sleep!
 */
static void userui_message(u32 section, u32 level, u32 normally_logged,
                const char *fmt, ...)
{
        struct userui_msg_params msg;

        if ((level) && (level > console_loglevel))
                return;

        memset(&msg, 0, sizeof(msg));

        msg.a = section;
        msg.b = level;
        msg.c = normally_logged;

        if (fmt) {
                va_list args;
                va_start(args, fmt);
                vsnprintf(msg.text, sizeof(msg.text), fmt, args);
                va_end(args);
                msg.text[sizeof(msg.text)-1] = '\0';
        }

        if (test_action_state(TOI_LOGALL))
                printk(KERN_INFO "%s\n", msg.text);

        toi_send_netlink_message(&ui_helper_data, USERUI_MSG_MESSAGE,
                        &msg, sizeof(msg));
}

/**
 * wait_for_key_via_userui - Wait for userui to receive a keypress.
 */
static void wait_for_key_via_userui(void)
{
        DECLARE_WAITQUEUE(wait, current);

        add_wait_queue(&userui_wait_for_key, &wait);
        set_current_state(TASK_INTERRUPTIBLE);

        wait_event_interruptible(userui_wait_for_key, userui_wait_should_wake);
        userui_wait_should_wake = false;

        set_current_state(TASK_RUNNING);
        remove_wait_queue(&userui_wait_for_key, &wait);
}

/**
 * userui_prepare_status - Display high level messages.
 *
 * @clearbar: Whether to clear the progress bar.
 * @fmt...: New message for the title.
 *
 * Prepare the 'nice display', drawing the header and version, along with the
 * current action and perhaps also resetting the progress bar.
 */
static void userui_prepare_status(int clearbar, const char *fmt, ...)
{
        va_list args;

        if (fmt) {
                va_start(args, fmt);
                lastheader_message_len = vsnprintf(lastheader, 512, fmt, args);
                va_end(args);
        }

        if (clearbar)
                toi_update_status(0, 1, NULL);

        if (ui_helper_data.pid == -1)
                printk(KERN_EMERG "%s\n", lastheader);
        else
                toi_message(0, TOI_STATUS, 1, lastheader, NULL);
}

/**
 * toi_wait_for_keypress - Wait for keypress via userui.
 *
 * @timeout: Maximum time to wait.
 *
 * Wait for a keypress from userui.
 *
 * FIXME: Implement timeout?
 */
static char userui_wait_for_keypress(int timeout)
{
        char key = '\0';

        if (ui_helper_data.pid != -1) {
                wait_for_key_via_userui();
                key = ' ';
        }

        return key;
}

/**
 * userui_abort_hibernate - Abort a cycle & tell user if they didn't request it.
 *
 * @result_code: Reason why we're aborting (1 << bit).
 * @fmt: Message to display if telling the user what's going on.
 *
 * Abort a cycle. If this wasn't at the user's request (and we're displaying
 * output), tell the user why and wait for them to acknowledge the message.
 */
static void userui_abort_hibernate(int result_code, const char *fmt, ...)
{
        va_list args;
        int printed_len = 0;

        set_result_state(result_code);

        if (test_result_state(TOI_ABORTED))
                return;

        set_result_state(TOI_ABORTED);

        if (test_result_state(TOI_ABORT_REQUESTED))
                return;

        va_start(args, fmt);
        printed_len = vsnprintf(local_printf_buf,  sizeof(local_printf_buf),
                        fmt, args);
        va_end(args);
        if (ui_helper_data.pid != -1)
                printed_len = sprintf(local_printf_buf + printed_len,
                                        " (Press SPACE to continue)");

        toi_prepare_status(CLEAR_BAR, "%s", local_printf_buf);

        if (ui_helper_data.pid != -1)
                userui_wait_for_keypress(0);
}

/**
 * request_abort_hibernate - Abort hibernating or resuming at user request.
 *
 * Handle the user requesting the cancellation of a hibernation or resume by
 * pressing escape.
 */
static void request_abort_hibernate(void)
{
        if (test_result_state(TOI_ABORT_REQUESTED) ||
           !test_action_state(TOI_CAN_CANCEL))
                return;

        if (test_toi_state(TOI_NOW_RESUMING)) {
                toi_prepare_status(CLEAR_BAR, "Escape pressed. "
                                        "Powering down again.");
                set_toi_state(TOI_STOP_RESUME);
                while (!test_toi_state(TOI_IO_STOPPED))
                        schedule();
                if (toiActiveAllocator->mark_resume_attempted)
                        toiActiveAllocator->mark_resume_attempted(0);
                toi_power_down();
        }

        toi_prepare_status(CLEAR_BAR, "--- ESCAPE PRESSED :"
                                        " ABORTING HIBERNATION ---");
        set_abort_result(TOI_ABORT_REQUESTED);
        toi_stop_waiting_for_userui_key();
}

/**
 * userui_user_rcv_msg - Receive a netlink message from userui.
 *
 * @skb: skb received.
 * @nlh: Netlink header received.
 */
static int userui_user_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
{
        int type;
        int *data;

        type = nlh->nlmsg_type;

        /* A control message: ignore them */
        if (type < NETLINK_MSG_BASE)
                return 0;

        /* Unknown message: reply with EINVAL */
        if (type >= USERUI_MSG_MAX)
                return -EINVAL;

        /* All operations require privileges, even GET */
        if (!capable(CAP_NET_ADMIN))
                return -EPERM;

        /* Only allow one task to receive NOFREEZE privileges */
        if (type == NETLINK_MSG_NOFREEZE_ME && ui_helper_data.pid != -1) {
                printk(KERN_INFO "Got NOFREEZE_ME request when "
                        "ui_helper_data.pid is %d.\n", ui_helper_data.pid);
                return -EBUSY;
        }

        data = (int *) NLMSG_DATA(nlh);

        switch (type) {
        case USERUI_MSG_ABORT:
                request_abort_hibernate();
                return 0;
        case USERUI_MSG_GET_STATE:
                toi_send_netlink_message(&ui_helper_data,
                                USERUI_MSG_GET_STATE, &toi_bkd.toi_action,
                                sizeof(toi_bkd.toi_action));
                return 0;
        case USERUI_MSG_GET_DEBUG_STATE:
                toi_send_netlink_message(&ui_helper_data,
                                USERUI_MSG_GET_DEBUG_STATE,
                                &toi_bkd.toi_debug_state,
                                sizeof(toi_bkd.toi_debug_state));
                return 0;
        case USERUI_MSG_SET_STATE:
                if (nlh->nlmsg_len < NLMSG_LENGTH(sizeof(int)))
                        return -EINVAL;
                ui_nl_set_state(*data);
                return 0;
        case USERUI_MSG_SET_DEBUG_STATE:
                if (nlh->nlmsg_len < NLMSG_LENGTH(sizeof(int)))
                        return -EINVAL;
                toi_bkd.toi_debug_state = (*data);
                return 0;
        case USERUI_MSG_SPACE:
                toi_stop_waiting_for_userui_key();
                return 0;
        case USERUI_MSG_GET_POWERDOWN_METHOD:
                toi_send_netlink_message(&ui_helper_data,
                                USERUI_MSG_GET_POWERDOWN_METHOD,
                                &toi_poweroff_method,
                                sizeof(toi_poweroff_method));
                return 0;
        case USERUI_MSG_SET_POWERDOWN_METHOD:
                if (nlh->nlmsg_len != NLMSG_LENGTH(sizeof(char)))
                        return -EINVAL;
                toi_poweroff_method = (unsigned long)(*data);
                return 0;
        case USERUI_MSG_GET_LOGLEVEL:
                toi_send_netlink_message(&ui_helper_data,
                                USERUI_MSG_GET_LOGLEVEL,
                                &toi_bkd.toi_default_console_level,
                                sizeof(toi_bkd.toi_default_console_level));
                return 0;
        case USERUI_MSG_SET_LOGLEVEL:
                if (nlh->nlmsg_len < NLMSG_LENGTH(sizeof(int)))
                        return -EINVAL;
                toi_bkd.toi_default_console_level = (*data);
                return 0;
        case USERUI_MSG_PRINTK:
                printk(KERN_INFO "%s", (char *) data);
                return 0;
        }

        /* Unhandled here */
        return 1;
}

/**
 * userui_cond_pause - Possibly pause at user request.
 *
 * @pause: Whether to pause or just display the message.
 * @message: Message to display at the start of pausing.
 *
 * Potentially pause and wait for the user to tell us to continue. We normally
 * only pause when @pause is set. While paused, the user can do things like
 * changing the loglevel, toggling the display of debugging sections and such
 * like.
 */
static void userui_cond_pause(int pause, char *message)
{
        int displayed_message = 0, last_key = 0;

        while (last_key != 32 &&
                ui_helper_data.pid != -1 &&
                ((test_action_state(TOI_PAUSE) && pause) ||
                 (test_action_state(TOI_SINGLESTEP)))) {
                if (!displayed_message) {
                        toi_prepare_status(DONT_CLEAR_BAR,
                           "%s Press SPACE to continue.%s",
                           message ? message : "",
                           (test_action_state(TOI_SINGLESTEP)) ?
                           " Single step on." : "");
                        displayed_message = 1;
                }
                last_key = userui_wait_for_keypress(0);
        }
        schedule();
}

/**
 * userui_prepare_console - Prepare the console for use.
 *
 * Prepare a console for use, saving current kmsg settings and attempting to
 * start userui. Console loglevel changes are handled by userui.
 */
static void userui_prepare_console(void)
{
        orig_kmsg = vt_kmsg_redirect(fg_console + 1);

        ui_helper_data.pid = -1;

        if (!userui_ops.enabled) {
                printk(KERN_INFO "TuxOnIce: Userui disabled.\n");
                return;
        }

        if (*ui_helper_data.program)
                toi_netlink_setup(&ui_helper_data);
        else
                printk(KERN_INFO "TuxOnIce: Userui program not configured.\n");
}

/**
 * userui_cleanup_console - Cleanup after a cycle.
 *
 * Tell userui to cleanup, and restore kmsg_redirect to its original value.
 */

static void userui_cleanup_console(void)
{
        if (ui_helper_data.pid > -1)
                toi_netlink_close(&ui_helper_data);

        vt_kmsg_redirect(orig_kmsg);
}

/*
 * User interface specific /sys/power/tuxonice entries.
 */

static struct toi_sysfs_data sysfs_params[] = {
#if defined(CONFIG_NET) && defined(CONFIG_SYSFS)
        SYSFS_BIT("enable_escape", SYSFS_RW, &toi_bkd.toi_action,
                        TOI_CAN_CANCEL, 0),
        SYSFS_BIT("pause_between_steps", SYSFS_RW, &toi_bkd.toi_action,
                        TOI_PAUSE, 0),
        SYSFS_INT("enabled", SYSFS_RW, &userui_ops.enabled, 0, 1, 0, NULL),
        SYSFS_INT("progress_granularity", SYSFS_RW, &progress_granularity, 1,
                        2048, 0, NULL),
        SYSFS_STRING("program", SYSFS_RW, ui_helper_data.program, 255, 0,
                        set_ui_program_set),
        SYSFS_INT("debug", SYSFS_RW, &ui_helper_data.debug, 0, 1, 0, NULL)
#endif
};

static struct toi_module_ops userui_ops = {
        .type                                = MISC_MODULE,
        .name                                = "userui",
        .shared_directory                = "user_interface",
        .module                                = THIS_MODULE,
        .storage_needed                        = userui_storage_needed,
        .save_config_info                = userui_save_config_info,
        .load_config_info                = userui_load_config_info,
        .memory_needed                        = userui_memory_needed,
        .post_atomic_restore                = userui_post_atomic_restore,
        .sysfs_data                        = sysfs_params,
        .num_sysfs_entries                = sizeof(sysfs_params) /
                sizeof(struct toi_sysfs_data),
};

static struct ui_ops my_ui_ops = {
        .update_status                        = userui_update_status,
        .message                        = userui_message,
        .prepare_status                        = userui_prepare_status,
        .abort                                = userui_abort_hibernate,
        .cond_pause                        = userui_cond_pause,
        .prepare                        = userui_prepare_console,
        .cleanup                        = userui_cleanup_console,
        .wait_for_key                        = userui_wait_for_keypress,
};

/**
 * toi_user_ui_init - Boot time initialisation for user interface.
 *
 * Invoked from the core init routine.
 */
static __init int toi_user_ui_init(void)
{
        int result;

        ui_helper_data.nl = NULL;
        strncpy(ui_helper_data.program, CONFIG_TOI_USERUI_DEFAULT_PATH, 255);
        ui_helper_data.pid = -1;
        ui_helper_data.skb_size = sizeof(struct userui_msg_params);
        ui_helper_data.pool_limit = 6;
        ui_helper_data.netlink_id = NETLINK_TOI_USERUI;
        ui_helper_data.name = "userspace ui";
        ui_helper_data.rcv_msg = userui_user_rcv_msg;
        ui_helper_data.interface_version = 8;
        ui_helper_data.must_init = 0;
        ui_helper_data.not_ready = userui_cleanup_console;
        init_completion(&ui_helper_data.wait_for_process);
        result = toi_register_module(&userui_ops);
        if (!result) {
          result = toi_register_ui_ops(&my_ui_ops);
          if (result)
            toi_unregister_module(&userui_ops);
        }

        return result;
}

late_initcall(toi_user_ui_init);