ux_stack.c

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/*******************************************************************************
 *   Ledger Nano S - Secure firmware
 *   (c) 2022 Ledger
 *
 *  Licensed under the Apache License, Version 2.0 (the "License");
 *  you may not use this file except in compliance with the License.
 *  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 *  Unless required by applicable law or agreed to in writing, software
 *  distributed under the License is distributed on an "AS IS" BASIS,
 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *  See the License for the specific language governing permissions and
 *  limitations under the License.
 ********************************************************************************/
 
#include "ux.h"
#include "os_pin.h"
#include "os_seed.h"
#include "os_screen.h"
#include "os_types.h"
#include "os_utils.h"
#include "os_io_seph_ux.h"
#include <string.h>
 
// return true (stack slot +1) if an element
unsigned int ux_stack_is_element_array_present(const bagl_element_t *element_array)
{
    unsigned int i, j;
 
    // looks for a element array though the ux stack
    for (i = 0; i < ARRAYLEN(G_ux.stack) && i < G_ux.stack_count; i++) {
        for (j = 0; j < UX_STACK_SLOT_ARRAY_COUNT && j < G_ux.stack[i].element_arrays_count; j++) {
            if (G_ux.stack[i].element_arrays[j].element_array == element_array) {
                return i + 1;
            }
        }
    }
 
    return 0;
}
 
unsigned int ux_stack_push(void)
{
    // only push if an available slot exists
    if (G_ux.stack_count < ARRAYLEN(G_ux.stack)) {
        memset(&G_ux.stack[G_ux.stack_count], 0, sizeof(G_ux.stack[0]));
#ifdef HAVE_UX_FLOW
        memset(&G_ux.flow_stack[G_ux.stack_count], 0, sizeof(G_ux.flow_stack[0]));
#endif  // HAVE_UX_FLOW
        G_ux.stack_count++;
    }
    // return the stack top index
    return G_ux.stack_count - 1;
}
 
unsigned int ux_stack_pop(void)
{
    unsigned int exit_code = BOLOS_UX_OK;
    // only pop if more than two stack entry (0 and 1,top is an index not a count)
    if (G_ux.stack_count > 0) {
        G_ux.stack_count--;
        if (G_ux.stack_count < UX_STACK_SLOT_COUNT) {
            exit_code = G_ux.stack[G_ux.stack_count].exit_code_after_elements_displayed;
            // wipe popped slot
            memset(&G_ux.stack[G_ux.stack_count], 0, sizeof(G_ux.stack[0]));
#ifdef HAVE_UX_FLOW
            memset(&G_ux.flow_stack[G_ux.stack_count], 0, sizeof(G_ux.flow_stack[0]));
#endif  // HAVE_UX_FLOW
        }
    }
 
    // prepare output code when popping the last stack screen
    if (G_ux.stack_count == 0) {
        G_ux.exit_code = exit_code;
    }
    // ask for a complete redraw (optimisation due to blink must be avoided as we're returning from
    // a modal, and within the bolos ux screen stack)
    else {
        // prepare to redraw the slot when asked
        G_ux.stack[G_ux.stack_count - 1].element_index = 0;
    }
    // return the stack top index (or -1 if no top)
    return G_ux.stack_count - 1;
}
 
void ux_stack_redisplay(void)
{
#ifdef HAVE_UX_FLOW
    // an ux step has been relayout on the screen, don't flicker by redisplaying here
    if (ux_flow_relayout()) {
        return;
    }
#endif  // HAVE_UX_FLOW
 
    // check if any screen is schedule for displaying
    if (G_ux.stack_count > 0 && G_ux.stack_count <= ARRAYLEN(G_ux.stack)) {
        G_ux.stack[G_ux.stack_count - 1].element_index = 0;
        ux_stack_display(G_ux.stack_count - 1);
    }
    // else return redraw for the app
    else if (G_ux.stack_count == 0) {
        if (G_ux.exit_code == BOLOS_UX_OK) {
            G_ux.exit_code = BOLOS_UX_REDRAW;
        }
    }
}
 
void ux_stack_insert(unsigned int stack_slot)
{
    if (stack_slot >= ARRAYLEN(G_ux.stack)) {
        return;  // arbitrary, this is feil that's it
    }
    // not a full stack
    if (G_ux.stack_count < ARRAYLEN(G_ux.stack)) {
        // if not inserting as top of stack, then perform move
        if (stack_slot != ARRAYLEN(G_ux.stack) - 1) {
            memmove(&G_ux.stack[stack_slot + 1],
                    &G_ux.stack[stack_slot],
                    (ARRAYLEN(G_ux.stack) - (stack_slot + 1)) * sizeof(G_ux.stack[0]));
#ifdef HAVE_UX_FLOW
            memmove(&G_ux.flow_stack[stack_slot + 1],
                    &G_ux.flow_stack[stack_slot],
                    (ARRAYLEN(G_ux.flow_stack) - (stack_slot + 1)) * sizeof(G_ux.flow_stack[0]));
#endif  // HAVE_UX_FLOW
        }
        memset(&G_ux.stack[stack_slot], 0, sizeof(ux_stack_slot_t));
#ifdef HAVE_UX_FLOW
        memset(&G_ux.flow_stack[stack_slot], 0, sizeof(ux_flow_state_t));
#endif  // HAVE_UX_FLOW
        // add the slot
        G_ux.stack_count++;
        // slot not wiped
    }
    // feil, that's it
}
 
void ux_stack_remove(unsigned int stack_slot)
{
    if (stack_slot > ARRAYLEN(G_ux.stack) - 1) {
        stack_slot = ARRAYLEN(G_ux.stack) - 1;
    }
 
    // removing something not in stack
    if (stack_slot >= G_ux.stack_count) {
        return;
    }
 
    // before: | screenz | removed screen | other screenz |
    // after:  | screenz | other screenz |
 
    if (stack_slot != ARRAYLEN(G_ux.stack) - 1) {
        memmove(&G_ux.stack[stack_slot],
                &G_ux.stack[stack_slot + 1],
                (ARRAYLEN(G_ux.stack) - (stack_slot + 1)) * sizeof(G_ux.stack[0]));
#ifdef HAVE_UX_FLOW
        // also move the flow attached to the popped screen
        memmove(&G_ux.flow_stack[stack_slot],
                &G_ux.flow_stack[stack_slot + 1],
                (ARRAYLEN(G_ux.flow_stack) - (stack_slot + 1)) * sizeof(G_ux.flow_stack[0]));
#endif  // HAVE_UX_FLOW
    }
 
    // wipe last slot
    ux_stack_pop();
}
 
// common code for all screens
void ux_stack_init(unsigned int stack_slot)
{
    /*
    // mismatch, the stack slot is not accessible !!
    if (G_ux.stack_count<stack_slot+1) {
      reset();
    }
    */
 
    if (stack_slot < UX_STACK_SLOT_COUNT) {
#ifdef HAVE_UX_STACK_INIT_KEEP_TICKER
        callback_int_t ticker_callback = G_ux.stack[stack_slot].ticker_callback;
        unsigned int   ticker_value    = G_ux.stack[stack_slot].ticker_value;
        unsigned int   ticker_interval = G_ux.stack[stack_slot].ticker_interval;
#endif  // HAVE_UX_STACK_INIT_KEEP_TICKER
 
        // wipe the slot to be displayed just in case
        memset(&G_ux.stack[stack_slot], 0, sizeof(G_ux.stack[0]));
 
#ifdef HAVE_UX_STACK_INIT_KEEP_TICKER
        G_ux.stack[stack_slot].ticker_callback = ticker_callback;
        G_ux.stack[stack_slot].ticker_value    = ticker_value;
        G_ux.stack[stack_slot].ticker_interval = ticker_interval;
#endif  // HAVE_UX_STACK_INIT_KEEP_TICKER
 
        // init current screen state
        G_ux.stack[stack_slot].exit_code_after_elements_displayed = BOLOS_UX_CONTINUE;
    }
}
 
// check to process keyboard callback before screen generic callback
const bagl_element_t *ux_stack_display_element_callback(const bagl_element_t *element)
{
    const bagl_element_t *el;
    if (G_ux.stack_count) {
        if (G_ux.stack[G_ux.stack_count - 1].screen_before_element_display_callback) {
            el = G_ux.stack[G_ux.stack_count - 1].screen_before_element_display_callback(element);
            if (!el) {
                return 0;
            }
            // legacy forvery old ux on blue and nano s
            if ((unsigned int) el != 1) {
                element = el;
            }
        }
    }
    // consider good to be displayed by default
    return element;
}
 
void ux_stack_display_elements(ux_stack_slot_t *slot)
{
    unsigned int          elem_idx;
    unsigned int          total_element_count;
    const bagl_element_t *element;
    unsigned int          i;
 
    total_element_count = 0;
    // can't display UX of the app, when PIN is not validated
#ifndef HAVE_BOLOS
    if ((os_perso_isonboarded() != BOLOS_UX_OK || os_global_pin_is_validated() == BOLOS_UX_OK))
#endif  // HAVE_BOLOS
    {
        for (i = 0; i < UX_STACK_SLOT_ARRAY_COUNT && i < slot->element_arrays_count; i++) {
            // compute elem_idx in the current array (element_index refers to the total number of
            // element to display)
            elem_idx = slot->element_index - total_element_count;
            total_element_count += slot->element_arrays[i].element_array_count;
            // check if we're sending from this array or not
            while (elem_idx < slot->element_arrays[i].element_array_count) {
                const bagl_element_t *el;
                // pre inc before callback to allow callback to change the next element to be drawn
                slot->element_index++;
 
                element = &slot->element_arrays[i].element_array[elem_idx];
                el      = ux_stack_display_element_callback(element);
                if (!el) {
                    // skip display if requested to
                    if (G_ux.exit_code != BOLOS_UX_CONTINUE) {
                        return;
                    }
                }
                else {
                    // legacy support
                    if ((unsigned int) el != 1) {
                        element = el;
                    }
                    io_seph_ux_display_bagl_element(element);
                }
                elem_idx++;
            }
        }
 
        // TODO draw the status bar
 
        if (slot->element_index == total_element_count) {
            // if screen has special stuff todo on exit
            screen_update();
            // screen marked as displayed
            slot->element_index++;
 
            // check if a displayed callback is requiring redraw
            if (slot->displayed_callback) {
                // if screen displayed callback requested one more round, then set CONTINUE exit
                // code
                if (!slot->displayed_callback(0)) {
                    slot->element_index = 0;
                    G_ux.exit_code      = BOLOS_UX_CONTINUE;
                    return;  // break;
                }
            }
            G_ux.exit_code = slot->exit_code_after_elements_displayed;
        }
    }
}
 
// common code for all screens
void ux_stack_display(unsigned int stack_slot)
{
    // don't display any elements of a previous screen replacement
    if (G_ux.stack_count > 0 && stack_slot + 1 == G_ux.stack_count) {
        // at worse a redisplay of the current screen has been requested, ensure to redraw it
        // correctly
        G_ux.stack[stack_slot].element_index = 0;
        ux_stack_display_elements(&G_ux.stack[stack_slot]);  // on balenos, no need to wait for the
                                                             // display processed event
    }
    // asking to redraw below top screen (likely the app below the ux)
    else if (stack_slot == -1UL || G_ux.stack_count == 0) {
        if (G_ux.exit_code == BOLOS_UX_OK) {
            G_ux.exit_code = BOLOS_UX_REDRAW;
        }
    }
    // else don't draw (in stack insertion)
}