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 extern void poke_blanked_console(void); 39 40 /* FIXME: all this needs locking */ 41 /* Variables for selection control. */ 42 /* Use a dynamic buffer, instead of static (Dec 1994) */ 43 struct vc_data *sel_cons; /* must not be deallocated */ 44 static int use_unicode; 45 static volatile int sel_start = -1; /* cleared by clear_selection */ 46 static int sel_end; 47 static int sel_buffer_lth; 48 static char *sel_buffer; 49 static DEFINE_MUTEX(sel_lock); 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 static inline void highlight(const int s, const int e) 56 { 57 invert_screen(sel_cons, s, e-s+2, 1); 58 } 59 60 /* use complementary color to show the pointer */ 61 static inline void highlight_pointer(const int where) 62 { 63 complement_pos(sel_cons, where); 64 } 65 66 static u32 67 sel_pos(int n) 68 { 69 if (use_unicode) 70 return screen_glyph_unicode(sel_cons, n / 2); 71 return inverse_translate(sel_cons, screen_glyph(sel_cons, n), 72 0); 73 } 74 75 /** 76 * clear_selection - remove current selection 77 * 78 * Remove the current selection highlight, if any from the console 79 * holding the selection. The caller must hold the console lock. 80 */ 81 void clear_selection(void) 82 { 83 highlight_pointer(-1); /* hide the pointer */ 84 if (sel_start != -1) { 85 highlight(sel_start, sel_end); 86 sel_start = -1; 87 } 88 } 89 EXPORT_SYMBOL_GPL(clear_selection); 90 91 /* 92 * User settable table: what characters are to be considered alphabetic? 93 * 128 bits. Locked by the console lock. 94 */ 95 static u32 inwordLut[]={ 96 0x00000000, /* control chars */ 97 0x03FFE000, /* digits and "-./" */ 98 0x87FFFFFE, /* uppercase and '_' */ 99 0x07FFFFFE, /* lowercase */ 100 }; 101 102 static inline int inword(const u32 c) 103 { 104 return c > 0x7f || (( inwordLut[c>>5] >> (c & 0x1F) ) & 1); 105 } 106 107 /** 108 * set loadlut - load the LUT table 109 * @p: user table 110 * 111 * Load the LUT table from user space. The caller must hold the console 112 * lock. Make a temporary copy so a partial update doesn't make a mess. 113 */ 114 int sel_loadlut(char __user *p) 115 { 116 u32 tmplut[ARRAY_SIZE(inwordLut)]; 117 if (copy_from_user(tmplut, (u32 __user *)(p+4), sizeof(inwordLut))) 118 return -EFAULT; 119 memcpy(inwordLut, tmplut, sizeof(inwordLut)); 120 return 0; 121 } 122 123 /* does screen address p correspond to character at LH/RH edge of screen? */ 124 static inline int atedge(const int p, int size_row) 125 { 126 return (!(p % size_row) || !((p + 2) % size_row)); 127 } 128 129 /* stores the char in UTF8 and returns the number of bytes used (1-4) */ 130 static int store_utf8(u32 c, char *p) 131 { 132 if (c < 0x80) { 133 /* 0******* */ 134 p[0] = c; 135 return 1; 136 } else if (c < 0x800) { 137 /* 110***** 10****** */ 138 p[0] = 0xc0 | (c >> 6); 139 p[1] = 0x80 | (c & 0x3f); 140 return 2; 141 } else if (c < 0x10000) { 142 /* 1110**** 10****** 10****** */ 143 p[0] = 0xe0 | (c >> 12); 144 p[1] = 0x80 | ((c >> 6) & 0x3f); 145 p[2] = 0x80 | (c & 0x3f); 146 return 3; 147 } else if (c < 0x110000) { 148 /* 11110*** 10****** 10****** 10****** */ 149 p[0] = 0xf0 | (c >> 18); 150 p[1] = 0x80 | ((c >> 12) & 0x3f); 151 p[2] = 0x80 | ((c >> 6) & 0x3f); 152 p[3] = 0x80 | (c & 0x3f); 153 return 4; 154 } else { 155 /* outside Unicode, replace with U+FFFD */ 156 p[0] = 0xef; 157 p[1] = 0xbf; 158 p[2] = 0xbd; 159 return 3; 160 } 161 } 162 163 /** 164 * set_selection_user - set the current selection. 165 * @sel: user selection info 166 * @tty: the console tty 167 * 168 * Invoked by the ioctl handle for the vt layer. 169 * 170 * The entire selection process is managed under the console_lock. It's 171 * a lot under the lock but its hardly a performance path 172 */ 173 int set_selection_user(const struct tiocl_selection __user *sel, 174 struct tty_struct *tty) 175 { 176 struct tiocl_selection v; 177 178 if (copy_from_user(&v, sel, sizeof(*sel))) 179 return -EFAULT; 180 181 return set_selection_kernel(&v, tty); 182 } 183 184 int set_selection_kernel(struct tiocl_selection *v, struct tty_struct *tty) 185 { 186 struct vc_data *vc = vc_cons[fg_console].d; 187 int new_sel_start, new_sel_end, spc; 188 char *bp, *obp; 189 int i, ps, pe, multiplier; 190 u32 c; 191 int mode, ret = 0; 192 193 poke_blanked_console(); 194 195 v->xs = min_t(u16, v->xs - 1, vc->vc_cols - 1); 196 v->ys = min_t(u16, v->ys - 1, vc->vc_rows - 1); 197 v->xe = min_t(u16, v->xe - 1, vc->vc_cols - 1); 198 v->ye = min_t(u16, v->ye - 1, vc->vc_rows - 1); 199 ps = v->ys * vc->vc_size_row + (v->xs << 1); 200 pe = v->ye * vc->vc_size_row + (v->xe << 1); 201 202 if (v->sel_mode == TIOCL_SELCLEAR) { 203 /* useful for screendump without selection highlights */ 204 clear_selection(); 205 return 0; 206 } 207 208 if (mouse_reporting() && (v->sel_mode & TIOCL_SELMOUSEREPORT)) { 209 mouse_report(tty, v->sel_mode & TIOCL_SELBUTTONMASK, v->xs, 210 v->ys); 211 return 0; 212 } 213 214 if (ps > pe) /* make sel_start <= sel_end */ 215 swap(ps, pe); 216 217 mutex_lock(&sel_lock); 218 if (sel_cons != vc_cons[fg_console].d) { 219 clear_selection(); 220 sel_cons = vc_cons[fg_console].d; 221 } 222 mode = vt_do_kdgkbmode(fg_console); 223 if (mode == K_UNICODE) 224 use_unicode = 1; 225 else 226 use_unicode = 0; 227 228 switch (v->sel_mode) 229 { 230 case TIOCL_SELCHAR: /* character-by-character selection */ 231 new_sel_start = ps; 232 new_sel_end = pe; 233 break; 234 case TIOCL_SELWORD: /* word-by-word selection */ 235 spc = isspace(sel_pos(ps)); 236 for (new_sel_start = ps; ; ps -= 2) 237 { 238 if ((spc && !isspace(sel_pos(ps))) || 239 (!spc && !inword(sel_pos(ps)))) 240 break; 241 new_sel_start = ps; 242 if (!(ps % vc->vc_size_row)) 243 break; 244 } 245 spc = isspace(sel_pos(pe)); 246 for (new_sel_end = pe; ; pe += 2) 247 { 248 if ((spc && !isspace(sel_pos(pe))) || 249 (!spc && !inword(sel_pos(pe)))) 250 break; 251 new_sel_end = pe; 252 if (!((pe + 2) % vc->vc_size_row)) 253 break; 254 } 255 break; 256 case TIOCL_SELLINE: /* line-by-line selection */ 257 new_sel_start = ps - ps % vc->vc_size_row; 258 new_sel_end = pe + vc->vc_size_row 259 - pe % vc->vc_size_row - 2; 260 break; 261 case TIOCL_SELPOINTER: 262 highlight_pointer(pe); 263 goto unlock; 264 default: 265 ret = -EINVAL; 266 goto unlock; 267 } 268 269 /* remove the pointer */ 270 highlight_pointer(-1); 271 272 /* select to end of line if on trailing space */ 273 if (new_sel_end > new_sel_start && 274 !atedge(new_sel_end, vc->vc_size_row) && 275 isspace(sel_pos(new_sel_end))) { 276 for (pe = new_sel_end + 2; ; pe += 2) 277 if (!isspace(sel_pos(pe)) || 278 atedge(pe, vc->vc_size_row)) 279 break; 280 if (isspace(sel_pos(pe))) 281 new_sel_end = pe; 282 } 283 if (sel_start == -1) /* no current selection */ 284 highlight(new_sel_start, new_sel_end); 285 else if (new_sel_start == sel_start) 286 { 287 if (new_sel_end == sel_end) /* no action required */ 288 goto unlock; 289 else if (new_sel_end > sel_end) /* extend to right */ 290 highlight(sel_end + 2, new_sel_end); 291 else /* contract from right */ 292 highlight(new_sel_end + 2, sel_end); 293 } 294 else if (new_sel_end == sel_end) 295 { 296 if (new_sel_start < sel_start) /* extend to left */ 297 highlight(new_sel_start, sel_start - 2); 298 else /* contract from left */ 299 highlight(sel_start, new_sel_start - 2); 300 } 301 else /* some other case; start selection from scratch */ 302 { 303 clear_selection(); 304 highlight(new_sel_start, new_sel_end); 305 } 306 sel_start = new_sel_start; 307 sel_end = new_sel_end; 308 309 /* Allocate a new buffer before freeing the old one ... */ 310 multiplier = use_unicode ? 4 : 1; /* chars can take up to 4 bytes */ 311 bp = kmalloc_array((sel_end - sel_start) / 2 + 1, multiplier, 312 GFP_KERNEL); 313 if (!bp) { 314 printk(KERN_WARNING "selection: kmalloc() failed\n"); 315 clear_selection(); 316 ret = -ENOMEM; 317 goto unlock; 318 } 319 kfree(sel_buffer); 320 sel_buffer = bp; 321 322 obp = bp; 323 for (i = sel_start; i <= sel_end; i += 2) { 324 c = sel_pos(i); 325 if (use_unicode) 326 bp += store_utf8(c, bp); 327 else 328 *bp++ = c; 329 if (!isspace(c)) 330 obp = bp; 331 if (! ((i + 2) % vc->vc_size_row)) { 332 /* strip trailing blanks from line and add newline, 333 unless non-space at end of line. */ 334 if (obp != bp) { 335 bp = obp; 336 *bp++ = '\r'; 337 } 338 obp = bp; 339 } 340 } 341 sel_buffer_lth = bp - sel_buffer; 342 unlock: 343 mutex_unlock(&sel_lock); 344 return ret; 345 } 346 EXPORT_SYMBOL_GPL(set_selection_kernel); 347 348 /* Insert the contents of the selection buffer into the 349 * queue of the tty associated with the current console. 350 * Invoked by ioctl(). 351 * 352 * Locking: called without locks. Calls the ldisc wrongly with 353 * unsafe methods, 354 */ 355 int paste_selection(struct tty_struct *tty) 356 { 357 struct vc_data *vc = tty->driver_data; 358 int pasted = 0; 359 unsigned int count; 360 struct tty_ldisc *ld; 361 DECLARE_WAITQUEUE(wait, current); 362 int ret = 0; 363 364 console_lock(); 365 poke_blanked_console(); 366 console_unlock(); 367 368 ld = tty_ldisc_ref_wait(tty); 369 if (!ld) 370 return -EIO; /* ldisc was hung up */ 371 tty_buffer_lock_exclusive(&vc->port); 372 373 add_wait_queue(&vc->paste_wait, &wait); 374 mutex_lock(&sel_lock); 375 while (sel_buffer && sel_buffer_lth > pasted) { 376 set_current_state(TASK_INTERRUPTIBLE); 377 if (signal_pending(current)) { 378 ret = -EINTR; 379 break; 380 } 381 if (tty_throttled(tty)) { 382 mutex_unlock(&sel_lock); 383 schedule(); 384 mutex_lock(&sel_lock); 385 continue; 386 } 387 __set_current_state(TASK_RUNNING); 388 count = sel_buffer_lth - pasted; 389 count = tty_ldisc_receive_buf(ld, sel_buffer + pasted, NULL, 390 count); 391 pasted += count; 392 } 393 mutex_unlock(&sel_lock); 394 remove_wait_queue(&vc->paste_wait, &wait); 395 __set_current_state(TASK_RUNNING); 396 397 tty_buffer_unlock_exclusive(&vc->port); 398 tty_ldisc_deref(ld); 399 return ret; 400 } 401 EXPORT_SYMBOL_GPL(paste_selection); 402