Line data Source code
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/mutex.h>
20 : #include <linux/slab.h>
21 : #include <linux/types.h>
22 :
23 : #include <linux/uaccess.h>
24 :
25 : #include <linux/kbd_kern.h>
26 : #include <linux/vt_kern.h>
27 : #include <linux/consolemap.h>
28 : #include <linux/selection.h>
29 : #include <linux/tiocl.h>
30 : #include <linux/console.h>
31 : #include <linux/tty_flip.h>
32 :
33 : #include <linux/sched/signal.h>
34 :
35 : /* Don't take this from <ctype.h>: 011-015 on the screen aren't spaces */
36 : #define isspace(c) ((c) == ' ')
37 :
38 : /* FIXME: all this needs locking */
39 : static struct vc_selection {
40 : struct mutex lock;
41 : struct vc_data *cons; /* must not be deallocated */
42 : char *buffer;
43 : unsigned int buf_len;
44 : volatile int start; /* cleared by clear_selection */
45 : int end;
46 : } vc_sel = {
47 : .lock = __MUTEX_INITIALIZER(vc_sel.lock),
48 : .start = -1,
49 : };
50 :
51 : /* clear_selection, highlight and highlight_pointer can be called
52 : from interrupt (via scrollback/front) */
53 :
54 : /* set reverse video on characters s-e of console with selection. */
55 0 : static inline void highlight(const int s, const int e)
56 : {
57 0 : invert_screen(vc_sel.cons, s, e-s+2, true);
58 0 : }
59 :
60 : /* use complementary color to show the pointer */
61 0 : static inline void highlight_pointer(const int where)
62 : {
63 0 : complement_pos(vc_sel.cons, where);
64 : }
65 :
66 : static u32
67 0 : sel_pos(int n, bool unicode)
68 : {
69 0 : if (unicode)
70 0 : return screen_glyph_unicode(vc_sel.cons, n / 2);
71 0 : return inverse_translate(vc_sel.cons, screen_glyph(vc_sel.cons, n), 0);
72 : }
73 :
74 : /**
75 : * clear_selection - remove current selection
76 : *
77 : * Remove the current selection highlight, if any from the console
78 : * holding the selection. The caller must hold the console lock.
79 : */
80 0 : void clear_selection(void)
81 : {
82 0 : highlight_pointer(-1); /* hide the pointer */
83 0 : if (vc_sel.start != -1) {
84 0 : highlight(vc_sel.start, vc_sel.end);
85 0 : vc_sel.start = -1;
86 : }
87 0 : }
88 : EXPORT_SYMBOL_GPL(clear_selection);
89 :
90 33 : bool vc_is_sel(struct vc_data *vc)
91 : {
92 33 : return vc == vc_sel.cons;
93 : }
94 :
95 : /*
96 : * User settable table: what characters are to be considered alphabetic?
97 : * 128 bits. Locked by the console lock.
98 : */
99 : static u32 inwordLut[]={
100 : 0x00000000, /* control chars */
101 : 0x03FFE000, /* digits and "-./" */
102 : 0x87FFFFFE, /* uppercase and '_' */
103 : 0x07FFFFFE, /* lowercase */
104 : };
105 :
106 0 : static inline int inword(const u32 c)
107 : {
108 0 : return c > 0x7f || (( inwordLut[c>>5] >> (c & 0x1F) ) & 1);
109 : }
110 :
111 : /**
112 : * set loadlut - load the LUT table
113 : * @p: user table
114 : *
115 : * Load the LUT table from user space. The caller must hold the console
116 : * lock. Make a temporary copy so a partial update doesn't make a mess.
117 : */
118 0 : int sel_loadlut(char __user *p)
119 : {
120 0 : u32 tmplut[ARRAY_SIZE(inwordLut)];
121 0 : if (copy_from_user(tmplut, (u32 __user *)(p+4), sizeof(inwordLut)))
122 : return -EFAULT;
123 0 : memcpy(inwordLut, tmplut, sizeof(inwordLut));
124 0 : return 0;
125 : }
126 :
127 : /* does screen address p correspond to character at LH/RH edge of screen? */
128 0 : static inline int atedge(const int p, int size_row)
129 : {
130 0 : return (!(p % size_row) || !((p + 2) % size_row));
131 : }
132 :
133 : /* stores the char in UTF8 and returns the number of bytes used (1-4) */
134 0 : static int store_utf8(u32 c, char *p)
135 : {
136 0 : if (c < 0x80) {
137 : /* 0******* */
138 0 : p[0] = c;
139 0 : return 1;
140 0 : } else if (c < 0x800) {
141 : /* 110***** 10****** */
142 0 : p[0] = 0xc0 | (c >> 6);
143 0 : p[1] = 0x80 | (c & 0x3f);
144 0 : return 2;
145 0 : } else if (c < 0x10000) {
146 : /* 1110**** 10****** 10****** */
147 0 : p[0] = 0xe0 | (c >> 12);
148 0 : p[1] = 0x80 | ((c >> 6) & 0x3f);
149 0 : p[2] = 0x80 | (c & 0x3f);
150 0 : return 3;
151 0 : } else if (c < 0x110000) {
152 : /* 11110*** 10****** 10****** 10****** */
153 0 : p[0] = 0xf0 | (c >> 18);
154 0 : p[1] = 0x80 | ((c >> 12) & 0x3f);
155 0 : p[2] = 0x80 | ((c >> 6) & 0x3f);
156 0 : p[3] = 0x80 | (c & 0x3f);
157 0 : return 4;
158 : } else {
159 : /* outside Unicode, replace with U+FFFD */
160 0 : p[0] = 0xef;
161 0 : p[1] = 0xbf;
162 0 : p[2] = 0xbd;
163 0 : return 3;
164 : }
165 : }
166 :
167 : /**
168 : * set_selection_user - set the current selection.
169 : * @sel: user selection info
170 : * @tty: the console tty
171 : *
172 : * Invoked by the ioctl handle for the vt layer.
173 : *
174 : * The entire selection process is managed under the console_lock. It's
175 : * a lot under the lock but its hardly a performance path
176 : */
177 0 : int set_selection_user(const struct tiocl_selection __user *sel,
178 : struct tty_struct *tty)
179 : {
180 0 : struct tiocl_selection v;
181 :
182 0 : if (copy_from_user(&v, sel, sizeof(*sel)))
183 : return -EFAULT;
184 :
185 0 : return set_selection_kernel(&v, tty);
186 : }
187 :
188 0 : static int vc_selection_store_chars(struct vc_data *vc, bool unicode)
189 : {
190 0 : char *bp, *obp;
191 0 : unsigned int i;
192 :
193 : /* Allocate a new buffer before freeing the old one ... */
194 : /* chars can take up to 4 bytes with unicode */
195 0 : bp = kmalloc_array((vc_sel.end - vc_sel.start) / 2 + 1, unicode ? 4 : 1,
196 : GFP_KERNEL | __GFP_NOWARN);
197 0 : if (!bp) {
198 0 : printk(KERN_WARNING "selection: kmalloc() failed\n");
199 0 : clear_selection();
200 0 : return -ENOMEM;
201 : }
202 0 : kfree(vc_sel.buffer);
203 0 : vc_sel.buffer = bp;
204 :
205 0 : obp = bp;
206 0 : for (i = vc_sel.start; i <= vc_sel.end; i += 2) {
207 0 : u32 c = sel_pos(i, unicode);
208 0 : if (unicode)
209 0 : bp += store_utf8(c, bp);
210 : else
211 0 : *bp++ = c;
212 0 : if (!isspace(c))
213 0 : obp = bp;
214 0 : if (!((i + 2) % vc->vc_size_row)) {
215 : /* strip trailing blanks from line and add newline,
216 : unless non-space at end of line. */
217 0 : if (obp != bp) {
218 0 : bp = obp;
219 0 : *bp++ = '\r';
220 : }
221 : obp = bp;
222 : }
223 : }
224 0 : vc_sel.buf_len = bp - vc_sel.buffer;
225 :
226 0 : return 0;
227 : }
228 :
229 0 : static int vc_do_selection(struct vc_data *vc, unsigned short mode, int ps,
230 : int pe)
231 : {
232 0 : int new_sel_start, new_sel_end, spc;
233 0 : bool unicode = vt_do_kdgkbmode(fg_console) == K_UNICODE;
234 :
235 0 : switch (mode) {
236 : case TIOCL_SELCHAR: /* character-by-character selection */
237 : new_sel_start = ps;
238 : new_sel_end = pe;
239 : break;
240 0 : case TIOCL_SELWORD: /* word-by-word selection */
241 0 : spc = isspace(sel_pos(ps, unicode));
242 0 : for (new_sel_start = ps; ; ps -= 2) {
243 0 : if ((spc && !isspace(sel_pos(ps, unicode))) ||
244 0 : (!spc && !inword(sel_pos(ps, unicode))))
245 : break;
246 0 : new_sel_start = ps;
247 0 : if (!(ps % vc->vc_size_row))
248 : break;
249 : }
250 :
251 0 : spc = isspace(sel_pos(pe, unicode));
252 0 : for (new_sel_end = pe; ; pe += 2) {
253 0 : if ((spc && !isspace(sel_pos(pe, unicode))) ||
254 0 : (!spc && !inword(sel_pos(pe, unicode))))
255 : break;
256 0 : new_sel_end = pe;
257 0 : if (!((pe + 2) % vc->vc_size_row))
258 : break;
259 : }
260 : break;
261 0 : case TIOCL_SELLINE: /* line-by-line selection */
262 0 : new_sel_start = rounddown(ps, vc->vc_size_row);
263 0 : new_sel_end = rounddown(pe, vc->vc_size_row) +
264 0 : vc->vc_size_row - 2;
265 0 : break;
266 : case TIOCL_SELPOINTER:
267 0 : highlight_pointer(pe);
268 0 : return 0;
269 : default:
270 : return -EINVAL;
271 : }
272 :
273 : /* remove the pointer */
274 0 : highlight_pointer(-1);
275 :
276 : /* select to end of line if on trailing space */
277 0 : if (new_sel_end > new_sel_start &&
278 0 : !atedge(new_sel_end, vc->vc_size_row) &&
279 0 : isspace(sel_pos(new_sel_end, unicode))) {
280 : for (pe = new_sel_end + 2; ; pe += 2)
281 0 : if (!isspace(sel_pos(pe, unicode)) ||
282 0 : atedge(pe, vc->vc_size_row))
283 : break;
284 0 : if (isspace(sel_pos(pe, unicode)))
285 0 : new_sel_end = pe;
286 : }
287 0 : if (vc_sel.start == -1) /* no current selection */
288 0 : highlight(new_sel_start, new_sel_end);
289 0 : else if (new_sel_start == vc_sel.start)
290 : {
291 0 : if (new_sel_end == vc_sel.end) /* no action required */
292 : return 0;
293 0 : else if (new_sel_end > vc_sel.end) /* extend to right */
294 0 : highlight(vc_sel.end + 2, new_sel_end);
295 : else /* contract from right */
296 0 : highlight(new_sel_end + 2, vc_sel.end);
297 : }
298 0 : else if (new_sel_end == vc_sel.end)
299 : {
300 0 : if (new_sel_start < vc_sel.start) /* extend to left */
301 0 : highlight(new_sel_start, vc_sel.start - 2);
302 : else /* contract from left */
303 0 : highlight(vc_sel.start, new_sel_start - 2);
304 : }
305 : else /* some other case; start selection from scratch */
306 : {
307 0 : clear_selection();
308 0 : highlight(new_sel_start, new_sel_end);
309 : }
310 0 : vc_sel.start = new_sel_start;
311 0 : vc_sel.end = new_sel_end;
312 :
313 0 : return vc_selection_store_chars(vc, unicode);
314 : }
315 :
316 0 : static int vc_selection(struct vc_data *vc, struct tiocl_selection *v,
317 : struct tty_struct *tty)
318 : {
319 0 : int ps, pe;
320 :
321 0 : poke_blanked_console();
322 :
323 0 : if (v->sel_mode == TIOCL_SELCLEAR) {
324 : /* useful for screendump without selection highlights */
325 0 : clear_selection();
326 0 : return 0;
327 : }
328 :
329 0 : v->xs = min_t(u16, v->xs - 1, vc->vc_cols - 1);
330 0 : v->ys = min_t(u16, v->ys - 1, vc->vc_rows - 1);
331 0 : v->xe = min_t(u16, v->xe - 1, vc->vc_cols - 1);
332 0 : v->ye = min_t(u16, v->ye - 1, vc->vc_rows - 1);
333 :
334 0 : if (mouse_reporting() && (v->sel_mode & TIOCL_SELMOUSEREPORT)) {
335 0 : mouse_report(tty, v->sel_mode & TIOCL_SELBUTTONMASK, v->xs,
336 0 : v->ys);
337 0 : return 0;
338 : }
339 :
340 0 : ps = v->ys * vc->vc_size_row + (v->xs << 1);
341 0 : pe = v->ye * vc->vc_size_row + (v->xe << 1);
342 0 : if (ps > pe) /* make vc_sel.start <= vc_sel.end */
343 0 : swap(ps, pe);
344 :
345 0 : if (vc_sel.cons != vc) {
346 0 : clear_selection();
347 0 : vc_sel.cons = vc;
348 : }
349 :
350 0 : return vc_do_selection(vc, v->sel_mode, ps, pe);
351 : }
352 :
353 0 : int set_selection_kernel(struct tiocl_selection *v, struct tty_struct *tty)
354 : {
355 0 : int ret;
356 :
357 0 : mutex_lock(&vc_sel.lock);
358 0 : console_lock();
359 0 : ret = vc_selection(vc_cons[fg_console].d, v, tty);
360 0 : console_unlock();
361 0 : mutex_unlock(&vc_sel.lock);
362 :
363 0 : return ret;
364 : }
365 : EXPORT_SYMBOL_GPL(set_selection_kernel);
366 :
367 : /* Insert the contents of the selection buffer into the
368 : * queue of the tty associated with the current console.
369 : * Invoked by ioctl().
370 : *
371 : * Locking: called without locks. Calls the ldisc wrongly with
372 : * unsafe methods,
373 : */
374 0 : int paste_selection(struct tty_struct *tty)
375 : {
376 0 : struct vc_data *vc = tty->driver_data;
377 0 : int pasted = 0;
378 0 : unsigned int count;
379 0 : struct tty_ldisc *ld;
380 0 : DECLARE_WAITQUEUE(wait, current);
381 0 : int ret = 0;
382 :
383 0 : console_lock();
384 0 : poke_blanked_console();
385 0 : console_unlock();
386 :
387 0 : ld = tty_ldisc_ref_wait(tty);
388 0 : if (!ld)
389 : return -EIO; /* ldisc was hung up */
390 0 : tty_buffer_lock_exclusive(&vc->port);
391 :
392 0 : add_wait_queue(&vc->paste_wait, &wait);
393 0 : mutex_lock(&vc_sel.lock);
394 0 : while (vc_sel.buffer && vc_sel.buf_len > pasted) {
395 0 : set_current_state(TASK_INTERRUPTIBLE);
396 0 : if (signal_pending(current)) {
397 : ret = -EINTR;
398 : break;
399 : }
400 0 : if (tty_throttled(tty)) {
401 0 : mutex_unlock(&vc_sel.lock);
402 0 : schedule();
403 0 : mutex_lock(&vc_sel.lock);
404 0 : continue;
405 : }
406 0 : __set_current_state(TASK_RUNNING);
407 0 : count = vc_sel.buf_len - pasted;
408 0 : count = tty_ldisc_receive_buf(ld, vc_sel.buffer + pasted, NULL,
409 : count);
410 0 : pasted += count;
411 : }
412 0 : mutex_unlock(&vc_sel.lock);
413 0 : remove_wait_queue(&vc->paste_wait, &wait);
414 0 : __set_current_state(TASK_RUNNING);
415 :
416 0 : tty_buffer_unlock_exclusive(&vc->port);
417 0 : tty_ldisc_deref(ld);
418 0 : return ret;
419 : }
420 : EXPORT_SYMBOL_GPL(paste_selection);
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