1 // SPDX-License-Identifier: GPL-2.0
2 #include <linux/slab.h> /* for kmalloc */
3 #include <linux/consolemap.h>
4 #include <linux/interrupt.h>
5 #include <linux/sched.h>
6 #include <linux/device.h> /* for dev_warn */
7 #include <linux/selection.h>
8 #include <linux/workqueue.h>
9 #include <linux/tty.h>
10 #include <linux/tty_flip.h>
11 #include <linux/atomic.h>
12
13 #include "speakup.h"
14
15 /* ------ cut and paste ----- */
16 /* Don't take this from <ctype.h>: 011-015 on the screen aren't spaces */
17 #define ishardspace(c) ((c) == ' ')
18
19 unsigned short spk_xs, spk_ys, spk_xe, spk_ye; /* our region points */
20
21 /* Variables for selection control. */
22 /* must not be deallocated */
23 struct vc_data *spk_sel_cons;
24 /* cleared by clear_selection */
25 static int sel_start = -1;
26 static int sel_end;
27 static int sel_buffer_lth;
28 static char *sel_buffer;
29
sel_pos(int n)30 static unsigned char sel_pos(int n)
31 {
32 return inverse_translate(spk_sel_cons,
33 screen_glyph(spk_sel_cons, n), 0);
34 }
35
speakup_clear_selection(void)36 void speakup_clear_selection(void)
37 {
38 sel_start = -1;
39 }
40
41 /* does screen address p correspond to character at LH/RH edge of screen? */
atedge(const int p,int size_row)42 static int atedge(const int p, int size_row)
43 {
44 return !(p % size_row) || !((p + 2) % size_row);
45 }
46
47 /* constrain v such that v <= u */
limit(const unsigned short v,const unsigned short u)48 static unsigned short limit(const unsigned short v, const unsigned short u)
49 {
50 return (v > u) ? u : v;
51 }
52
speakup_set_selection(struct tty_struct * tty)53 int speakup_set_selection(struct tty_struct *tty)
54 {
55 int new_sel_start, new_sel_end;
56 char *bp, *obp;
57 int i, ps, pe;
58 struct vc_data *vc = vc_cons[fg_console].d;
59
60 spk_xs = limit(spk_xs, vc->vc_cols - 1);
61 spk_ys = limit(spk_ys, vc->vc_rows - 1);
62 spk_xe = limit(spk_xe, vc->vc_cols - 1);
63 spk_ye = limit(spk_ye, vc->vc_rows - 1);
64 ps = spk_ys * vc->vc_size_row + (spk_xs << 1);
65 pe = spk_ye * vc->vc_size_row + (spk_xe << 1);
66
67 if (ps > pe) /* make sel_start <= sel_end */
68 swap(ps, pe);
69
70 if (spk_sel_cons != vc_cons[fg_console].d) {
71 speakup_clear_selection();
72 spk_sel_cons = vc_cons[fg_console].d;
73 dev_warn(tty->dev,
74 "Selection: mark console not the same as cut\n");
75 return -EINVAL;
76 }
77
78 new_sel_start = ps;
79 new_sel_end = pe;
80
81 /* select to end of line if on trailing space */
82 if (new_sel_end > new_sel_start &&
83 !atedge(new_sel_end, vc->vc_size_row) &&
84 ishardspace(sel_pos(new_sel_end))) {
85 for (pe = new_sel_end + 2; ; pe += 2)
86 if (!ishardspace(sel_pos(pe)) ||
87 atedge(pe, vc->vc_size_row))
88 break;
89 if (ishardspace(sel_pos(pe)))
90 new_sel_end = pe;
91 }
92 if ((new_sel_start == sel_start) && (new_sel_end == sel_end))
93 return 0; /* no action required */
94
95 sel_start = new_sel_start;
96 sel_end = new_sel_end;
97 /* Allocate a new buffer before freeing the old one ... */
98 bp = kmalloc((sel_end - sel_start) / 2 + 1, GFP_ATOMIC);
99 if (!bp) {
100 speakup_clear_selection();
101 return -ENOMEM;
102 }
103 kfree(sel_buffer);
104 sel_buffer = bp;
105
106 obp = bp;
107 for (i = sel_start; i <= sel_end; i += 2) {
108 *bp = sel_pos(i);
109 if (!ishardspace(*bp++))
110 obp = bp;
111 if (!((i + 2) % vc->vc_size_row)) {
112 /* strip trailing blanks from line and add newline,
113 * unless non-space at end of line.
114 */
115 if (obp != bp) {
116 bp = obp;
117 *bp++ = '\r';
118 }
119 obp = bp;
120 }
121 }
122 sel_buffer_lth = bp - sel_buffer;
123 return 0;
124 }
125
126 struct speakup_paste_work {
127 struct work_struct work;
128 struct tty_struct *tty;
129 };
130
__speakup_paste_selection(struct work_struct * work)131 static void __speakup_paste_selection(struct work_struct *work)
132 {
133 struct speakup_paste_work *spw =
134 container_of(work, struct speakup_paste_work, work);
135 struct tty_struct *tty = xchg(&spw->tty, NULL);
136 struct vc_data *vc = (struct vc_data *)tty->driver_data;
137 int pasted = 0, count;
138 struct tty_ldisc *ld;
139 DECLARE_WAITQUEUE(wait, current);
140
141 ld = tty_ldisc_ref(tty);
142 if (!ld)
143 goto tty_unref;
144 tty_buffer_lock_exclusive(&vc->port);
145
146 add_wait_queue(&vc->paste_wait, &wait);
147 while (sel_buffer && sel_buffer_lth > pasted) {
148 set_current_state(TASK_INTERRUPTIBLE);
149 if (tty_throttled(tty)) {
150 schedule();
151 continue;
152 }
153 count = sel_buffer_lth - pasted;
154 count = tty_ldisc_receive_buf(ld, sel_buffer + pasted, NULL,
155 count);
156 pasted += count;
157 }
158 remove_wait_queue(&vc->paste_wait, &wait);
159 __set_current_state(TASK_RUNNING);
160
161 tty_buffer_unlock_exclusive(&vc->port);
162 tty_ldisc_deref(ld);
163 tty_unref:
164 tty_kref_put(tty);
165 }
166
167 static struct speakup_paste_work speakup_paste_work = {
168 .work = __WORK_INITIALIZER(speakup_paste_work.work,
169 __speakup_paste_selection)
170 };
171
speakup_paste_selection(struct tty_struct * tty)172 int speakup_paste_selection(struct tty_struct *tty)
173 {
174 if (cmpxchg(&speakup_paste_work.tty, NULL, tty))
175 return -EBUSY;
176
177 tty_kref_get(tty);
178 schedule_work_on(WORK_CPU_UNBOUND, &speakup_paste_work.work);
179 return 0;
180 }
181
speakup_cancel_paste(void)182 void speakup_cancel_paste(void)
183 {
184 cancel_work_sync(&speakup_paste_work.work);
185 tty_kref_put(speakup_paste_work.tty);
186 }
187
