1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * This module exports the functions:
4 *
5 * 'int set_selection_user(struct tiocl_selection __user *,
6 * struct tty_struct *)'
7 * 'int set_selection_kernel(struct tiocl_selection *, struct tty_struct *)'
8 * 'void clear_selection(void)'
9 * 'int paste_selection(struct tty_struct *)'
10 * 'int sel_loadlut(char __user *)'
11 *
12 * Now that /dev/vcs exists, most of this can disappear again.
13 */
14
15 #include <linux/module.h>
16 #include <linux/tty.h>
17 #include <linux/sched.h>
18 #include <linux/mm.h>
19 #include <linux/slab.h>
20 #include <linux/types.h>
21
22 #include <linux/uaccess.h>
23
24 #include <linux/kbd_kern.h>
25 #include <linux/vt_kern.h>
26 #include <linux/consolemap.h>
27 #include <linux/selection.h>
28 #include <linux/tiocl.h>
29 #include <linux/console.h>
30 #include <linux/tty_flip.h>
31
32 /* Don't take this from <ctype.h>: 011-015 on the screen aren't spaces */
33 #define isspace(c) ((c) == ' ')
34
35 extern void poke_blanked_console(void);
36
37 /* FIXME: all this needs locking */
38 /* Variables for selection control. */
39 /* Use a dynamic buffer, instead of static (Dec 1994) */
40 struct vc_data *sel_cons; /* must not be deallocated */
41 static int use_unicode;
42 static volatile int sel_start = -1; /* cleared by clear_selection */
43 static int sel_end;
44 static int sel_buffer_lth;
45 static char *sel_buffer;
46
47 /* clear_selection, highlight and highlight_pointer can be called
48 from interrupt (via scrollback/front) */
49
50 /* set reverse video on characters s-e of console with selection. */
highlight(const int s,const int e)51 static inline void highlight(const int s, const int e)
52 {
53 invert_screen(sel_cons, s, e-s+2, 1);
54 }
55
56 /* use complementary color to show the pointer */
highlight_pointer(const int where)57 static inline void highlight_pointer(const int where)
58 {
59 complement_pos(sel_cons, where);
60 }
61
62 static u32
sel_pos(int n)63 sel_pos(int n)
64 {
65 if (use_unicode)
66 return screen_glyph_unicode(sel_cons, n / 2);
67 return inverse_translate(sel_cons, screen_glyph(sel_cons, n),
68 0);
69 }
70
71 /**
72 * clear_selection - remove current selection
73 *
74 * Remove the current selection highlight, if any from the console
75 * holding the selection. The caller must hold the console lock.
76 */
clear_selection(void)77 void clear_selection(void)
78 {
79 highlight_pointer(-1); /* hide the pointer */
80 if (sel_start != -1) {
81 highlight(sel_start, sel_end);
82 sel_start = -1;
83 }
84 }
85 EXPORT_SYMBOL_GPL(clear_selection);
86
87 /*
88 * User settable table: what characters are to be considered alphabetic?
89 * 128 bits. Locked by the console lock.
90 */
91 static u32 inwordLut[]={
92 0x00000000, /* control chars */
93 0x03FFE000, /* digits and "-./" */
94 0x87FFFFFE, /* uppercase and '_' */
95 0x07FFFFFE, /* lowercase */
96 };
97
inword(const u32 c)98 static inline int inword(const u32 c)
99 {
100 return c > 0x7f || (( inwordLut[c>>5] >> (c & 0x1F) ) & 1);
101 }
102
103 /**
104 * set loadlut - load the LUT table
105 * @p: user table
106 *
107 * Load the LUT table from user space. The caller must hold the console
108 * lock. Make a temporary copy so a partial update doesn't make a mess.
109 */
sel_loadlut(char __user * p)110 int sel_loadlut(char __user *p)
111 {
112 u32 tmplut[ARRAY_SIZE(inwordLut)];
113 if (copy_from_user(tmplut, (u32 __user *)(p+4), sizeof(inwordLut)))
114 return -EFAULT;
115 memcpy(inwordLut, tmplut, sizeof(inwordLut));
116 return 0;
117 }
118
119 /* does screen address p correspond to character at LH/RH edge of screen? */
atedge(const int p,int size_row)120 static inline int atedge(const int p, int size_row)
121 {
122 return (!(p % size_row) || !((p + 2) % size_row));
123 }
124
125 /* stores the char in UTF8 and returns the number of bytes used (1-4) */
store_utf8(u32 c,char * p)126 static int store_utf8(u32 c, char *p)
127 {
128 if (c < 0x80) {
129 /* 0******* */
130 p[0] = c;
131 return 1;
132 } else if (c < 0x800) {
133 /* 110***** 10****** */
134 p[0] = 0xc0 | (c >> 6);
135 p[1] = 0x80 | (c & 0x3f);
136 return 2;
137 } else if (c < 0x10000) {
138 /* 1110**** 10****** 10****** */
139 p[0] = 0xe0 | (c >> 12);
140 p[1] = 0x80 | ((c >> 6) & 0x3f);
141 p[2] = 0x80 | (c & 0x3f);
142 return 3;
143 } else if (c < 0x110000) {
144 /* 11110*** 10****** 10****** 10****** */
145 p[0] = 0xf0 | (c >> 18);
146 p[1] = 0x80 | ((c >> 12) & 0x3f);
147 p[2] = 0x80 | ((c >> 6) & 0x3f);
148 p[3] = 0x80 | (c & 0x3f);
149 return 4;
150 } else {
151 /* outside Unicode, replace with U+FFFD */
152 p[0] = 0xef;
153 p[1] = 0xbf;
154 p[2] = 0xbd;
155 return 3;
156 }
157 }
158
159 /**
160 * set_selection_user - set the current selection.
161 * @sel: user selection info
162 * @tty: the console tty
163 *
164 * Invoked by the ioctl handle for the vt layer.
165 *
166 * The entire selection process is managed under the console_lock. It's
167 * a lot under the lock but its hardly a performance path
168 */
set_selection_user(const struct tiocl_selection __user * sel,struct tty_struct * tty)169 int set_selection_user(const struct tiocl_selection __user *sel,
170 struct tty_struct *tty)
171 {
172 struct tiocl_selection v;
173
174 if (copy_from_user(&v, sel, sizeof(*sel)))
175 return -EFAULT;
176
177 return set_selection_kernel(&v, tty);
178 }
179
set_selection_kernel(struct tiocl_selection * v,struct tty_struct * tty)180 int set_selection_kernel(struct tiocl_selection *v, struct tty_struct *tty)
181 {
182 struct vc_data *vc = vc_cons[fg_console].d;
183 int new_sel_start, new_sel_end, spc;
184 char *bp, *obp;
185 int i, ps, pe, multiplier;
186 u32 c;
187 int mode;
188
189 poke_blanked_console();
190
191 v->xs = min_t(u16, v->xs - 1, vc->vc_cols - 1);
192 v->ys = min_t(u16, v->ys - 1, vc->vc_rows - 1);
193 v->xe = min_t(u16, v->xe - 1, vc->vc_cols - 1);
194 v->ye = min_t(u16, v->ye - 1, vc->vc_rows - 1);
195 ps = v->ys * vc->vc_size_row + (v->xs << 1);
196 pe = v->ye * vc->vc_size_row + (v->xe << 1);
197
198 if (v->sel_mode == TIOCL_SELCLEAR) {
199 /* useful for screendump without selection highlights */
200 clear_selection();
201 return 0;
202 }
203
204 if (mouse_reporting() && (v->sel_mode & TIOCL_SELMOUSEREPORT)) {
205 mouse_report(tty, v->sel_mode & TIOCL_SELBUTTONMASK, v->xs,
206 v->ys);
207 return 0;
208 }
209
210 if (ps > pe) /* make sel_start <= sel_end */
211 swap(ps, pe);
212
213 if (sel_cons != vc_cons[fg_console].d) {
214 clear_selection();
215 sel_cons = vc_cons[fg_console].d;
216 }
217 mode = vt_do_kdgkbmode(fg_console);
218 if (mode == K_UNICODE)
219 use_unicode = 1;
220 else
221 use_unicode = 0;
222
223 switch (v->sel_mode)
224 {
225 case TIOCL_SELCHAR: /* character-by-character selection */
226 new_sel_start = ps;
227 new_sel_end = pe;
228 break;
229 case TIOCL_SELWORD: /* word-by-word selection */
230 spc = isspace(sel_pos(ps));
231 for (new_sel_start = ps; ; ps -= 2)
232 {
233 if ((spc && !isspace(sel_pos(ps))) ||
234 (!spc && !inword(sel_pos(ps))))
235 break;
236 new_sel_start = ps;
237 if (!(ps % vc->vc_size_row))
238 break;
239 }
240 spc = isspace(sel_pos(pe));
241 for (new_sel_end = pe; ; pe += 2)
242 {
243 if ((spc && !isspace(sel_pos(pe))) ||
244 (!spc && !inword(sel_pos(pe))))
245 break;
246 new_sel_end = pe;
247 if (!((pe + 2) % vc->vc_size_row))
248 break;
249 }
250 break;
251 case TIOCL_SELLINE: /* line-by-line selection */
252 new_sel_start = ps - ps % vc->vc_size_row;
253 new_sel_end = pe + vc->vc_size_row
254 - pe % vc->vc_size_row - 2;
255 break;
256 case TIOCL_SELPOINTER:
257 highlight_pointer(pe);
258 return 0;
259 default:
260 return -EINVAL;
261 }
262
263 /* remove the pointer */
264 highlight_pointer(-1);
265
266 /* select to end of line if on trailing space */
267 if (new_sel_end > new_sel_start &&
268 !atedge(new_sel_end, vc->vc_size_row) &&
269 isspace(sel_pos(new_sel_end))) {
270 for (pe = new_sel_end + 2; ; pe += 2)
271 if (!isspace(sel_pos(pe)) ||
272 atedge(pe, vc->vc_size_row))
273 break;
274 if (isspace(sel_pos(pe)))
275 new_sel_end = pe;
276 }
277 if (sel_start == -1) /* no current selection */
278 highlight(new_sel_start, new_sel_end);
279 else if (new_sel_start == sel_start)
280 {
281 if (new_sel_end == sel_end) /* no action required */
282 return 0;
283 else if (new_sel_end > sel_end) /* extend to right */
284 highlight(sel_end + 2, new_sel_end);
285 else /* contract from right */
286 highlight(new_sel_end + 2, sel_end);
287 }
288 else if (new_sel_end == sel_end)
289 {
290 if (new_sel_start < sel_start) /* extend to left */
291 highlight(new_sel_start, sel_start - 2);
292 else /* contract from left */
293 highlight(sel_start, new_sel_start - 2);
294 }
295 else /* some other case; start selection from scratch */
296 {
297 clear_selection();
298 highlight(new_sel_start, new_sel_end);
299 }
300 sel_start = new_sel_start;
301 sel_end = new_sel_end;
302
303 /* Allocate a new buffer before freeing the old one ... */
304 multiplier = use_unicode ? 4 : 1; /* chars can take up to 4 bytes */
305 bp = kmalloc_array((sel_end - sel_start) / 2 + 1, multiplier,
306 GFP_KERNEL);
307 if (!bp) {
308 printk(KERN_WARNING "selection: kmalloc() failed\n");
309 clear_selection();
310 return -ENOMEM;
311 }
312 kfree(sel_buffer);
313 sel_buffer = bp;
314
315 obp = bp;
316 for (i = sel_start; i <= sel_end; i += 2) {
317 c = sel_pos(i);
318 if (use_unicode)
319 bp += store_utf8(c, bp);
320 else
321 *bp++ = c;
322 if (!isspace(c))
323 obp = bp;
324 if (! ((i + 2) % vc->vc_size_row)) {
325 /* strip trailing blanks from line and add newline,
326 unless non-space at end of line. */
327 if (obp != bp) {
328 bp = obp;
329 *bp++ = '\r';
330 }
331 obp = bp;
332 }
333 }
334 sel_buffer_lth = bp - sel_buffer;
335 return 0;
336 }
337 EXPORT_SYMBOL_GPL(set_selection_kernel);
338
339 /* Insert the contents of the selection buffer into the
340 * queue of the tty associated with the current console.
341 * Invoked by ioctl().
342 *
343 * Locking: called without locks. Calls the ldisc wrongly with
344 * unsafe methods,
345 */
paste_selection(struct tty_struct * tty)346 int paste_selection(struct tty_struct *tty)
347 {
348 struct vc_data *vc = tty->driver_data;
349 int pasted = 0;
350 unsigned int count;
351 struct tty_ldisc *ld;
352 DECLARE_WAITQUEUE(wait, current);
353
354 console_lock();
355 poke_blanked_console();
356 console_unlock();
357
358 ld = tty_ldisc_ref_wait(tty);
359 if (!ld)
360 return -EIO; /* ldisc was hung up */
361 tty_buffer_lock_exclusive(&vc->port);
362
363 add_wait_queue(&vc->paste_wait, &wait);
364 while (sel_buffer && sel_buffer_lth > pasted) {
365 set_current_state(TASK_INTERRUPTIBLE);
366 if (tty_throttled(tty)) {
367 schedule();
368 continue;
369 }
370 __set_current_state(TASK_RUNNING);
371 count = sel_buffer_lth - pasted;
372 count = tty_ldisc_receive_buf(ld, sel_buffer + pasted, NULL,
373 count);
374 pasted += count;
375 }
376 remove_wait_queue(&vc->paste_wait, &wait);
377 __set_current_state(TASK_RUNNING);
378
379 tty_buffer_unlock_exclusive(&vc->port);
380 tty_ldisc_deref(ld);
381 return 0;
382 }
383 EXPORT_SYMBOL_GPL(paste_selection);
384
