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b2441318 1// SPDX-License-Identifier: GPL-2.0
1da177e4 2/*
1da177e4
LT
3 * This module exports the functions:
4 *
5 * 'int set_selection(struct tiocl_selection __user *, struct tty_struct *)'
6 * 'void clear_selection(void)'
7 * 'int paste_selection(struct tty_struct *)'
8 * 'int sel_loadlut(char __user *)'
9 *
10 * Now that /dev/vcs exists, most of this can disappear again.
11 */
12
13#include <linux/module.h>
14#include <linux/tty.h>
15#include <linux/sched.h>
16#include <linux/mm.h>
17#include <linux/slab.h>
18#include <linux/types.h>
19
7c0f6ba6 20#include <linux/uaccess.h>
1da177e4 21
759448f4 22#include <linux/kbd_kern.h>
1da177e4
LT
23#include <linux/vt_kern.h>
24#include <linux/consolemap.h>
25#include <linux/selection.h>
26#include <linux/tiocl.h>
27#include <linux/console.h>
a7c8d58c 28#include <linux/tty_flip.h>
1da177e4
LT
29
30/* Don't take this from <ctype.h>: 011-015 on the screen aren't spaces */
31#define isspace(c) ((c) == ' ')
32
33extern void poke_blanked_console(void);
34
079c9534 35/* FIXME: all this needs locking */
1da177e4
LT
36/* Variables for selection control. */
37/* Use a dynamic buffer, instead of static (Dec 1994) */
ca9bda00 38struct vc_data *sel_cons; /* must not be deallocated */
759448f4 39static int use_unicode;
1da177e4
LT
40static volatile int sel_start = -1; /* cleared by clear_selection */
41static int sel_end;
42static int sel_buffer_lth;
43static char *sel_buffer;
44
45/* clear_selection, highlight and highlight_pointer can be called
46 from interrupt (via scrollback/front) */
47
48/* set reverse video on characters s-e of console with selection. */
49static inline void highlight(const int s, const int e)
50{
51 invert_screen(sel_cons, s, e-s+2, 1);
52}
53
54/* use complementary color to show the pointer */
55static inline void highlight_pointer(const int where)
56{
57 complement_pos(sel_cons, where);
58}
59
759448f4 60static u16
1da177e4
LT
61sel_pos(int n)
62{
759448f4
JE
63 return inverse_translate(sel_cons, screen_glyph(sel_cons, n),
64 use_unicode);
1da177e4
LT
65}
66
5289475d
AC
67/**
68 * clear_selection - remove current selection
69 *
70 * Remove the current selection highlight, if any from the console
71 * holding the selection. The caller must hold the console lock.
72 */
73void clear_selection(void)
74{
1da177e4
LT
75 highlight_pointer(-1); /* hide the pointer */
76 if (sel_start != -1) {
77 highlight(sel_start, sel_end);
78 sel_start = -1;
79 }
80}
81
82/*
83 * User settable table: what characters are to be considered alphabetic?
7f1534e1 84 * 128 bits. Locked by the console lock.
1da177e4 85 */
7f1534e1 86static u32 inwordLut[]={
1da177e4 87 0x00000000, /* control chars */
7d6d44ae 88 0x03FFE000, /* digits and "-./" */
1da177e4
LT
89 0x87FFFFFE, /* uppercase and '_' */
90 0x07FFFFFE, /* lowercase */
1da177e4
LT
91};
92
759448f4 93static inline int inword(const u16 c) {
7f1534e1 94 return c > 0x7f || (( inwordLut[c>>5] >> (c & 0x1F) ) & 1);
1da177e4
LT
95}
96
5289475d
AC
97/**
98 * set loadlut - load the LUT table
99 * @p: user table
100 *
101 * Load the LUT table from user space. The caller must hold the console
102 * lock. Make a temporary copy so a partial update doesn't make a mess.
103 */
1da177e4
LT
104int sel_loadlut(char __user *p)
105{
7f1534e1
AB
106 u32 tmplut[ARRAY_SIZE(inwordLut)];
107 if (copy_from_user(tmplut, (u32 __user *)(p+4), sizeof(inwordLut)))
5289475d 108 return -EFAULT;
7f1534e1 109 memcpy(inwordLut, tmplut, sizeof(inwordLut));
5289475d 110 return 0;
1da177e4
LT
111}
112
113/* does screen address p correspond to character at LH/RH edge of screen? */
114static inline int atedge(const int p, int size_row)
115{
116 return (!(p % size_row) || !((p + 2) % size_row));
117}
118
119/* constrain v such that v <= u */
120static inline unsigned short limit(const unsigned short v, const unsigned short u)
121{
122 return (v > u) ? u : v;
123}
124
759448f4
JE
125/* stores the char in UTF8 and returns the number of bytes used (1-3) */
126static int store_utf8(u16 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 {
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 }
144}
145
5289475d
AC
146/**
147 * set_selection - set the current selection.
148 * @sel: user selection info
149 * @tty: the console tty
150 *
151 * Invoked by the ioctl handle for the vt layer.
152 *
153 * The entire selection process is managed under the console_lock. It's
154 * a lot under the lock but its hardly a performance path
155 */
1da177e4
LT
156int set_selection(const struct tiocl_selection __user *sel, struct tty_struct *tty)
157{
158 struct vc_data *vc = vc_cons[fg_console].d;
2a479aa8
AV
159 int new_sel_start, new_sel_end, spc;
160 struct tiocl_selection v;
1da177e4 161 char *bp, *obp;
759448f4
JE
162 int i, ps, pe, multiplier;
163 u16 c;
079c9534 164 int mode;
1da177e4
LT
165
166 poke_blanked_console();
2a479aa8
AV
167 if (copy_from_user(&v, sel, sizeof(*sel)))
168 return -EFAULT;
1da177e4 169
2a479aa8
AV
170 v.xs = limit(v.xs - 1, vc->vc_cols - 1);
171 v.ys = limit(v.ys - 1, vc->vc_rows - 1);
172 v.xe = limit(v.xe - 1, vc->vc_cols - 1);
173 v.ye = limit(v.ye - 1, vc->vc_rows - 1);
174 ps = v.ys * vc->vc_size_row + (v.xs << 1);
175 pe = v.ye * vc->vc_size_row + (v.xe << 1);
1da177e4 176
2a479aa8
AV
177 if (v.sel_mode == TIOCL_SELCLEAR) {
178 /* useful for screendump without selection highlights */
179 clear_selection();
180 return 0;
181 }
182
183 if (mouse_reporting() && (v.sel_mode & TIOCL_SELMOUSEREPORT)) {
184 mouse_report(tty, v.sel_mode & TIOCL_SELBUTTONMASK, v.xs, v.ys);
185 return 0;
186 }
1da177e4
LT
187
188 if (ps > pe) /* make sel_start <= sel_end */
df3d9a5b 189 swap(ps, pe);
1da177e4
LT
190
191 if (sel_cons != vc_cons[fg_console].d) {
192 clear_selection();
193 sel_cons = vc_cons[fg_console].d;
194 }
079c9534
AC
195 mode = vt_do_kdgkbmode(fg_console);
196 if (mode == K_UNICODE)
197 use_unicode = 1;
198 else
199 use_unicode = 0;
1da177e4 200
2a479aa8 201 switch (v.sel_mode)
1da177e4
LT
202 {
203 case TIOCL_SELCHAR: /* character-by-character selection */
204 new_sel_start = ps;
205 new_sel_end = pe;
206 break;
207 case TIOCL_SELWORD: /* word-by-word selection */
208 spc = isspace(sel_pos(ps));
209 for (new_sel_start = ps; ; ps -= 2)
210 {
211 if ((spc && !isspace(sel_pos(ps))) ||
212 (!spc && !inword(sel_pos(ps))))
213 break;
214 new_sel_start = ps;
215 if (!(ps % vc->vc_size_row))
216 break;
217 }
218 spc = isspace(sel_pos(pe));
219 for (new_sel_end = pe; ; pe += 2)
220 {
221 if ((spc && !isspace(sel_pos(pe))) ||
222 (!spc && !inword(sel_pos(pe))))
223 break;
224 new_sel_end = pe;
225 if (!((pe + 2) % vc->vc_size_row))
226 break;
227 }
228 break;
229 case TIOCL_SELLINE: /* line-by-line selection */
230 new_sel_start = ps - ps % vc->vc_size_row;
231 new_sel_end = pe + vc->vc_size_row
232 - pe % vc->vc_size_row - 2;
233 break;
234 case TIOCL_SELPOINTER:
235 highlight_pointer(pe);
236 return 0;
237 default:
238 return -EINVAL;
239 }
240
241 /* remove the pointer */
242 highlight_pointer(-1);
243
244 /* select to end of line if on trailing space */
245 if (new_sel_end > new_sel_start &&
246 !atedge(new_sel_end, vc->vc_size_row) &&
247 isspace(sel_pos(new_sel_end))) {
248 for (pe = new_sel_end + 2; ; pe += 2)
249 if (!isspace(sel_pos(pe)) ||
250 atedge(pe, vc->vc_size_row))
251 break;
252 if (isspace(sel_pos(pe)))
253 new_sel_end = pe;
254 }
255 if (sel_start == -1) /* no current selection */
256 highlight(new_sel_start, new_sel_end);
257 else if (new_sel_start == sel_start)
258 {
259 if (new_sel_end == sel_end) /* no action required */
260 return 0;
261 else if (new_sel_end > sel_end) /* extend to right */
262 highlight(sel_end + 2, new_sel_end);
263 else /* contract from right */
264 highlight(new_sel_end + 2, sel_end);
265 }
266 else if (new_sel_end == sel_end)
267 {
268 if (new_sel_start < sel_start) /* extend to left */
269 highlight(new_sel_start, sel_start - 2);
270 else /* contract from left */
271 highlight(sel_start, new_sel_start - 2);
272 }
273 else /* some other case; start selection from scratch */
274 {
275 clear_selection();
276 highlight(new_sel_start, new_sel_end);
277 }
278 sel_start = new_sel_start;
279 sel_end = new_sel_end;
280
281 /* Allocate a new buffer before freeing the old one ... */
759448f4 282 multiplier = use_unicode ? 3 : 1; /* chars can take up to 3 bytes */
6da2ec56
KC
283 bp = kmalloc_array((sel_end - sel_start) / 2 + 1, multiplier,
284 GFP_KERNEL);
1da177e4
LT
285 if (!bp) {
286 printk(KERN_WARNING "selection: kmalloc() failed\n");
287 clear_selection();
288 return -ENOMEM;
289 }
735d5661 290 kfree(sel_buffer);
1da177e4
LT
291 sel_buffer = bp;
292
293 obp = bp;
294 for (i = sel_start; i <= sel_end; i += 2) {
759448f4
JE
295 c = sel_pos(i);
296 if (use_unicode)
297 bp += store_utf8(c, bp);
298 else
299 *bp++ = c;
300 if (!isspace(c))
1da177e4
LT
301 obp = bp;
302 if (! ((i + 2) % vc->vc_size_row)) {
303 /* strip trailing blanks from line and add newline,
304 unless non-space at end of line. */
305 if (obp != bp) {
306 bp = obp;
307 *bp++ = '\r';
308 }
309 obp = bp;
310 }
311 }
312 sel_buffer_lth = bp - sel_buffer;
313 return 0;
314}
315
316/* Insert the contents of the selection buffer into the
317 * queue of the tty associated with the current console.
318 * Invoked by ioctl().
906cbe13 319 *
20f62579
AC
320 * Locking: called without locks. Calls the ldisc wrongly with
321 * unsafe methods,
1da177e4
LT
322 */
323int paste_selection(struct tty_struct *tty)
324{
c9f19e96 325 struct vc_data *vc = tty->driver_data;
33f0f88f
AC
326 int pasted = 0;
327 unsigned int count;
1da177e4
LT
328 struct tty_ldisc *ld;
329 DECLARE_WAITQUEUE(wait, current);
330
ac751efa 331 console_lock();
1da177e4 332 poke_blanked_console();
ac751efa 333 console_unlock();
1da177e4 334
7ee00fdb 335 ld = tty_ldisc_ref_wait(tty);
e55afd11
PH
336 if (!ld)
337 return -EIO; /* ldisc was hung up */
a7c8d58c 338 tty_buffer_lock_exclusive(&vc->port);
60af22d2 339
1da177e4
LT
340 add_wait_queue(&vc->paste_wait, &wait);
341 while (sel_buffer && sel_buffer_lth > pasted) {
342 set_current_state(TASK_INTERRUPTIBLE);
97ef38b8 343 if (tty_throttled(tty)) {
1da177e4
LT
344 schedule();
345 continue;
346 }
61e86cc9 347 __set_current_state(TASK_RUNNING);
1da177e4 348 count = sel_buffer_lth - pasted;
24a89d1c
PH
349 count = tty_ldisc_receive_buf(ld, sel_buffer + pasted, NULL,
350 count);
1da177e4
LT
351 pasted += count;
352 }
353 remove_wait_queue(&vc->paste_wait, &wait);
cc0a8fbb 354 __set_current_state(TASK_RUNNING);
1da177e4 355
a7c8d58c 356 tty_buffer_unlock_exclusive(&vc->port);
1da177e4
LT
357 tty_ldisc_deref(ld);
358 return 0;
359}