1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3 * Copyright 2010-2011 Calxeda, Inc.
4 * Copyright (c) 2019, NVIDIA CORPORATION. All rights reserved.
5 */
6
7 #include <common.h>
8 #include <cli.h>
9 #include <malloc.h>
10 #include <errno.h>
11 #include <linux/list.h>
12
13 #include "menu.h"
14
15 /*
16 * Internally, each item in a menu is represented by a struct menu_item.
17 *
18 * These items will be alloc'd and initialized by menu_item_add and destroyed
19 * by menu_item_destroy, and the consumer of the interface never sees that
20 * this struct is used at all.
21 */
22 struct menu_item {
23 char *key;
24 void *data;
25 struct list_head list;
26 };
27
28 /*
29 * The menu is composed of a list of items along with settings and callbacks
30 * provided by the user. An incomplete definition of this struct is available
31 * in menu.h, but the full definition is here to prevent consumers from
32 * relying on its contents.
33 */
34 struct menu {
35 struct menu_item *default_item;
36 int timeout;
37 char *title;
38 int prompt;
39 void (*item_data_print)(void *);
40 char *(*item_choice)(void *);
41 void *item_choice_data;
42 struct list_head items;
43 int item_cnt;
44 };
45
46 /*
47 * An iterator function for menu items. callback will be called for each item
48 * in m, with m, a pointer to the item, and extra being passed to callback. If
49 * callback returns a value other than NULL, iteration stops and the value
50 * return by callback is returned from menu_items_iter. This allows it to be
51 * used for search type operations. It is also safe for callback to remove the
52 * item from the list of items.
53 */
menu_items_iter(struct menu * m,void * (* callback)(struct menu *,struct menu_item *,void *),void * extra)54 static inline void *menu_items_iter(struct menu *m,
55 void *(*callback)(struct menu *, struct menu_item *, void *),
56 void *extra)
57 {
58 struct list_head *pos, *n;
59 struct menu_item *item;
60 void *ret;
61
62 list_for_each_safe(pos, n, &m->items) {
63 item = list_entry(pos, struct menu_item, list);
64
65 ret = callback(m, item, extra);
66
67 if (ret)
68 return ret;
69 }
70
71 return NULL;
72 }
73
74 /*
75 * Print a menu_item. If the consumer provided an item_data_print function
76 * when creating the menu, call it with a pointer to the item's private data.
77 * Otherwise, print the key of the item.
78 */
menu_item_print(struct menu * m,struct menu_item * item,void * extra)79 static inline void *menu_item_print(struct menu *m,
80 struct menu_item *item,
81 void *extra)
82 {
83 if (!m->item_data_print) {
84 puts(item->key);
85 putc('\n');
86 } else {
87 m->item_data_print(item->data);
88 }
89
90 return NULL;
91 }
92
93 /*
94 * Free the memory used by a menu item. This includes the memory used by its
95 * key.
96 */
menu_item_destroy(struct menu * m,struct menu_item * item,void * extra)97 static inline void *menu_item_destroy(struct menu *m,
98 struct menu_item *item,
99 void *extra)
100 {
101 if (item->key)
102 free(item->key);
103
104 free(item);
105
106 return NULL;
107 }
108
menu_display_statusline(struct menu * m)109 __weak void menu_display_statusline(struct menu *m)
110 {
111 }
112
113 /*
114 * Display a menu so the user can make a choice of an item. First display its
115 * title, if any, and then each item in the menu.
116 */
menu_display(struct menu * m)117 static inline void menu_display(struct menu *m)
118 {
119 if (m->title) {
120 puts(m->title);
121 putc('\n');
122 }
123 menu_display_statusline(m);
124
125 menu_items_iter(m, menu_item_print, NULL);
126 }
127
128 /*
129 * Check if an item's key matches a provided string, pointed to by extra. If
130 * extra is NULL, an item with a NULL key will match. Otherwise, the item's
131 * key has to match according to strcmp.
132 *
133 * This is called via menu_items_iter, so it returns a pointer to the item if
134 * the key matches, and returns NULL otherwise.
135 */
menu_item_key_match(struct menu * m,struct menu_item * item,void * extra)136 static inline void *menu_item_key_match(struct menu *m,
137 struct menu_item *item, void *extra)
138 {
139 char *item_key = extra;
140
141 if (!item_key || !item->key) {
142 if (item_key == item->key)
143 return item;
144
145 return NULL;
146 }
147
148 if (strcmp(item->key, item_key) == 0)
149 return item;
150
151 return NULL;
152 }
153
154 /*
155 * Find the first item with a key matching item_key, if any exists.
156 */
menu_item_by_key(struct menu * m,char * item_key)157 static inline struct menu_item *menu_item_by_key(struct menu *m,
158 char *item_key)
159 {
160 return menu_items_iter(m, menu_item_key_match, item_key);
161 }
162
163 /*
164 * Set *choice to point to the default item's data, if any default item was
165 * set, and returns 1. If no default item was set, returns -ENOENT.
166 */
menu_default_choice(struct menu * m,void ** choice)167 int menu_default_choice(struct menu *m, void **choice)
168 {
169 if (m->default_item) {
170 *choice = m->default_item->data;
171 return 1;
172 }
173
174 return -ENOENT;
175 }
176
177 /*
178 * Displays the menu and asks the user to choose an item. *choice will point
179 * to the private data of the item the user chooses. The user makes a choice
180 * by inputting a string matching the key of an item. Invalid choices will
181 * cause the user to be prompted again, repeatedly, until the user makes a
182 * valid choice. The user can exit the menu without making a choice via ^c.
183 *
184 * Returns 1 if the user made a choice, or -EINTR if they bail via ^c.
185 */
menu_interactive_choice(struct menu * m,void ** choice)186 static inline int menu_interactive_choice(struct menu *m, void **choice)
187 {
188 char cbuf[CONFIG_SYS_CBSIZE];
189 struct menu_item *choice_item = NULL;
190 int readret;
191
192 while (!choice_item) {
193 cbuf[0] = '\0';
194
195 menu_display(m);
196
197 if (!m->item_choice) {
198 readret = cli_readline_into_buffer("Enter choice: ",
199 cbuf, m->timeout);
200
201 if (readret >= 0) {
202 choice_item = menu_item_by_key(m, cbuf);
203 if (!choice_item)
204 printf("%s not found\n", cbuf);
205 } else if (readret == -1) {
206 printf("<INTERRUPT>\n");
207 return -EINTR;
208 } else {
209 return menu_default_choice(m, choice);
210 }
211 } else {
212 char *key = m->item_choice(m->item_choice_data);
213
214 if (key)
215 choice_item = menu_item_by_key(m, key);
216 }
217
218 if (!choice_item)
219 m->timeout = 0;
220 }
221
222 *choice = choice_item->data;
223
224 return 1;
225 }
226
227 /*
228 * menu_default_set() - Sets the default choice for the menu. This is safe to
229 * call more than once on a menu.
230 *
231 * m - Points to a menu created by menu_create().
232 *
233 * item_key - Points to a string that, when compared using strcmp, matches the
234 * key for an existing item in the menu.
235 *
236 * Returns 1 if successful, -EINVAL if m is NULL, or -ENOENT if no item with a
237 * key matching item_key is found.
238 */
menu_default_set(struct menu * m,char * item_key)239 int menu_default_set(struct menu *m, char *item_key)
240 {
241 struct menu_item *item;
242
243 if (!m)
244 return -EINVAL;
245
246 item = menu_item_by_key(m, item_key);
247
248 if (!item)
249 return -ENOENT;
250
251 m->default_item = item;
252
253 return 1;
254 }
255
256 /*
257 * menu_get_choice() - Returns the user's selected menu entry, or the default
258 * if the menu is set to not prompt or the timeout expires. This is safe to
259 * call more than once.
260 *
261 * m - Points to a menu created by menu_create().
262 *
263 * choice - Points to a location that will store a pointer to the selected
264 * menu item. If no item is selected or there is an error, no value will be
265 * written at the location it points to.
266 *
267 * Returns 1 if successful, -EINVAL if m or choice is NULL, -ENOENT if no
268 * default has been set and the menu is set to not prompt or the timeout
269 * expires, or -EINTR if the user exits the menu via ^c.
270 */
menu_get_choice(struct menu * m,void ** choice)271 int menu_get_choice(struct menu *m, void **choice)
272 {
273 if (!m || !choice)
274 return -EINVAL;
275
276 if (!m->prompt || m->item_cnt == 1)
277 return menu_default_choice(m, choice);
278
279 return menu_interactive_choice(m, choice);
280 }
281
282 /*
283 * menu_item_add() - Adds or replaces a menu item. Note that this replaces the
284 * data of an item if it already exists, but doesn't change the order of the
285 * item.
286 *
287 * m - Points to a menu created by menu_create().
288 *
289 * item_key - Points to a string that will uniquely identify the item. The
290 * string will be copied to internal storage, and is safe to discard after
291 * passing to menu_item_add.
292 *
293 * item_data - An opaque pointer associated with an item. It is never
294 * dereferenced internally, but will be passed to the item_data_print, and
295 * will be returned from menu_get_choice if the menu item is selected.
296 *
297 * Returns 1 if successful, -EINVAL if m is NULL, or -ENOMEM if there is
298 * insufficient memory to add the menu item.
299 */
menu_item_add(struct menu * m,char * item_key,void * item_data)300 int menu_item_add(struct menu *m, char *item_key, void *item_data)
301 {
302 struct menu_item *item;
303
304 if (!m)
305 return -EINVAL;
306
307 item = menu_item_by_key(m, item_key);
308
309 if (item) {
310 item->data = item_data;
311 return 1;
312 }
313
314 item = malloc(sizeof *item);
315 if (!item)
316 return -ENOMEM;
317
318 item->key = strdup(item_key);
319
320 if (!item->key) {
321 free(item);
322 return -ENOMEM;
323 }
324
325 item->data = item_data;
326
327 list_add_tail(&item->list, &m->items);
328 m->item_cnt++;
329
330 return 1;
331 }
332
333 /*
334 * menu_create() - Creates a menu handle with default settings
335 *
336 * title - If not NULL, points to a string that will be displayed before the
337 * list of menu items. It will be copied to internal storage, and is safe to
338 * discard after passing to menu_create().
339 *
340 * timeout - A delay in seconds to wait for user input. If 0, timeout is
341 * disabled, and the default choice will be returned unless prompt is 1.
342 *
343 * prompt - If 0, don't ask for user input unless there is an interrupted
344 * timeout. If 1, the user will be prompted for input regardless of the value
345 * of timeout.
346 *
347 * item_data_print - If not NULL, will be called for each item when the menu
348 * is displayed, with the pointer to the item's data passed as the argument.
349 * If NULL, each item's key will be printed instead. Since an item's key is
350 * what must be entered to select an item, the item_data_print function should
351 * make it obvious what the key for each entry is.
352 *
353 * item_choice - If not NULL, will be called when asking the user to choose an
354 * item. Returns a key string corresponding to the chosen item or NULL if
355 * no item has been selected.
356 *
357 * item_choice_data - Will be passed as the argument to the item_choice function
358 *
359 * Returns a pointer to the menu if successful, or NULL if there is
360 * insufficient memory available to create the menu.
361 */
menu_create(char * title,int timeout,int prompt,void (* item_data_print)(void *),char * (* item_choice)(void *),void * item_choice_data)362 struct menu *menu_create(char *title, int timeout, int prompt,
363 void (*item_data_print)(void *),
364 char *(*item_choice)(void *),
365 void *item_choice_data)
366 {
367 struct menu *m;
368
369 m = malloc(sizeof *m);
370
371 if (!m)
372 return NULL;
373
374 m->default_item = NULL;
375 m->prompt = prompt;
376 m->timeout = timeout;
377 m->item_data_print = item_data_print;
378 m->item_choice = item_choice;
379 m->item_choice_data = item_choice_data;
380 m->item_cnt = 0;
381
382 if (title) {
383 m->title = strdup(title);
384 if (!m->title) {
385 free(m);
386 return NULL;
387 }
388 } else
389 m->title = NULL;
390
391
392 INIT_LIST_HEAD(&m->items);
393
394 return m;
395 }
396
397 /*
398 * menu_destroy() - frees the memory used by a menu and its items.
399 *
400 * m - Points to a menu created by menu_create().
401 *
402 * Returns 1 if successful, or -EINVAL if m is NULL.
403 */
menu_destroy(struct menu * m)404 int menu_destroy(struct menu *m)
405 {
406 if (!m)
407 return -EINVAL;
408
409 menu_items_iter(m, menu_item_destroy, NULL);
410
411 if (m->title)
412 free(m->title);
413
414 free(m);
415
416 return 1;
417 }
418