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(u32 __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 is_space_on_vt(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 static inline void highlight(const int s, const int e) 56 { 57 invert_screen(vc_sel.cons, s, e-s+2, true); 58 } 59 60 /* use complementary color to show the pointer */ 61 static inline void highlight_pointer(const int where) 62 { 63 complement_pos(vc_sel.cons, where); 64 } 65 66 static u32 67 sel_pos(int n, bool unicode) 68 { 69 if (unicode) 70 return screen_glyph_unicode(vc_sel.cons, n / 2); 71 return inverse_translate(vc_sel.cons, screen_glyph(vc_sel.cons, n), 72 false); 73 } 74 75 /** 76 * clear_selection - remove current selection 77 * 78 * Remove the current selection highlight, if any from the console holding the 79 * selection. 80 * 81 * Locking: The caller must hold the console lock. 82 */ 83 void clear_selection(void) 84 { 85 highlight_pointer(-1); /* hide the pointer */ 86 if (vc_sel.start != -1) { 87 highlight(vc_sel.start, vc_sel.end); 88 vc_sel.start = -1; 89 } 90 } 91 EXPORT_SYMBOL_GPL(clear_selection); 92 93 bool vc_is_sel(const struct vc_data *vc) 94 { 95 return vc == vc_sel.cons; 96 } 97 98 /* 99 * User settable table: what characters are to be considered alphabetic? 100 * 128 bits. Locked by the console lock. 101 */ 102 static u32 inwordLut[]={ 103 0x00000000, /* control chars */ 104 0x03FFE000, /* digits and "-./" */ 105 0x87FFFFFE, /* uppercase and '_' */ 106 0x07FFFFFE, /* lowercase */ 107 }; 108 109 static inline int inword(const u32 c) 110 { 111 return c > 0x7f || (( inwordLut[c>>5] >> (c & 0x1F) ) & 1); 112 } 113 114 /** 115 * sel_loadlut() - load the LUT table 116 * @lut: user table 117 * 118 * Load the LUT table from user space. Make a temporary copy so a partial 119 * update doesn't make a mess. 120 * 121 * Locking: The console lock is acquired. 122 */ 123 int sel_loadlut(u32 __user *lut) 124 { 125 u32 tmplut[ARRAY_SIZE(inwordLut)]; 126 127 if (copy_from_user(tmplut, lut, sizeof(inwordLut))) 128 return -EFAULT; 129 130 console_lock(); 131 memcpy(inwordLut, tmplut, sizeof(inwordLut)); 132 console_unlock(); 133 134 return 0; 135 } 136 137 /* does screen address p correspond to character at LH/RH edge of screen? */ 138 static inline int atedge(const int p, int size_row) 139 { 140 return (!(p % size_row) || !((p + 2) % size_row)); 141 } 142 143 /* stores the char in UTF8 and returns the number of bytes used (1-4) */ 144 static int store_utf8(u32 c, char *p) 145 { 146 if (c < 0x80) { 147 /* 0******* */ 148 p[0] = c; 149 return 1; 150 } else if (c < 0x800) { 151 /* 110***** 10****** */ 152 p[0] = 0xc0 | (c >> 6); 153 p[1] = 0x80 | (c & 0x3f); 154 return 2; 155 } else if (c < 0x10000) { 156 /* 1110**** 10****** 10****** */ 157 p[0] = 0xe0 | (c >> 12); 158 p[1] = 0x80 | ((c >> 6) & 0x3f); 159 p[2] = 0x80 | (c & 0x3f); 160 return 3; 161 } else if (c < 0x110000) { 162 /* 11110*** 10****** 10****** 10****** */ 163 p[0] = 0xf0 | (c >> 18); 164 p[1] = 0x80 | ((c >> 12) & 0x3f); 165 p[2] = 0x80 | ((c >> 6) & 0x3f); 166 p[3] = 0x80 | (c & 0x3f); 167 return 4; 168 } else { 169 /* outside Unicode, replace with U+FFFD */ 170 p[0] = 0xef; 171 p[1] = 0xbf; 172 p[2] = 0xbd; 173 return 3; 174 } 175 } 176 177 /** 178 * set_selection_user - set the current selection. 179 * @sel: user selection info 180 * @tty: the console tty 181 * 182 * Invoked by the ioctl handle for the vt layer. 183 * 184 * Locking: The entire selection process is managed under the console_lock. 185 * It's a lot under the lock but its hardly a performance path. 186 */ 187 int set_selection_user(const struct tiocl_selection __user *sel, 188 struct tty_struct *tty) 189 { 190 struct tiocl_selection v; 191 192 if (copy_from_user(&v, sel, sizeof(*sel))) 193 return -EFAULT; 194 195 /* 196 * TIOCL_SELCLEAR and TIOCL_SELPOINTER are OK to use without 197 * CAP_SYS_ADMIN as they do not modify the selection. 198 */ 199 switch (v.sel_mode) { 200 case TIOCL_SELCLEAR: 201 case TIOCL_SELPOINTER: 202 break; 203 default: 204 if (!capable(CAP_SYS_ADMIN)) 205 return -EPERM; 206 } 207 208 return set_selection_kernel(&v, tty); 209 } 210 211 static int vc_selection_store_chars(struct vc_data *vc, bool unicode) 212 { 213 char *bp, *obp; 214 unsigned int i; 215 216 /* Allocate a new buffer before freeing the old one ... */ 217 /* chars can take up to 4 bytes with unicode */ 218 bp = kmalloc_array((vc_sel.end - vc_sel.start) / 2 + 1, unicode ? 4 : 1, 219 GFP_KERNEL | __GFP_NOWARN); 220 if (!bp) { 221 printk(KERN_WARNING "selection: kmalloc() failed\n"); 222 clear_selection(); 223 return -ENOMEM; 224 } 225 kfree(vc_sel.buffer); 226 vc_sel.buffer = bp; 227 228 obp = bp; 229 for (i = vc_sel.start; i <= vc_sel.end; i += 2) { 230 u32 c = sel_pos(i, unicode); 231 if (unicode) 232 bp += store_utf8(c, bp); 233 else 234 *bp++ = c; 235 if (!is_space_on_vt(c)) 236 obp = bp; 237 if (!((i + 2) % vc->vc_size_row)) { 238 /* strip trailing blanks from line and add newline, 239 unless non-space at end of line. */ 240 if (obp != bp) { 241 bp = obp; 242 *bp++ = '\r'; 243 } 244 obp = bp; 245 } 246 } 247 vc_sel.buf_len = bp - vc_sel.buffer; 248 249 return 0; 250 } 251 252 static int vc_do_selection(struct vc_data *vc, unsigned short mode, int ps, 253 int pe) 254 { 255 int new_sel_start, new_sel_end, spc; 256 bool unicode = vt_do_kdgkbmode(fg_console) == K_UNICODE; 257 258 switch (mode) { 259 case TIOCL_SELCHAR: /* character-by-character selection */ 260 new_sel_start = ps; 261 new_sel_end = pe; 262 break; 263 case TIOCL_SELWORD: /* word-by-word selection */ 264 spc = is_space_on_vt(sel_pos(ps, unicode)); 265 for (new_sel_start = ps; ; ps -= 2) { 266 if ((spc && !is_space_on_vt(sel_pos(ps, unicode))) || 267 (!spc && !inword(sel_pos(ps, unicode)))) 268 break; 269 new_sel_start = ps; 270 if (!(ps % vc->vc_size_row)) 271 break; 272 } 273 274 spc = is_space_on_vt(sel_pos(pe, unicode)); 275 for (new_sel_end = pe; ; pe += 2) { 276 if ((spc && !is_space_on_vt(sel_pos(pe, unicode))) || 277 (!spc && !inword(sel_pos(pe, unicode)))) 278 break; 279 new_sel_end = pe; 280 if (!((pe + 2) % vc->vc_size_row)) 281 break; 282 } 283 break; 284 case TIOCL_SELLINE: /* line-by-line selection */ 285 new_sel_start = rounddown(ps, vc->vc_size_row); 286 new_sel_end = rounddown(pe, vc->vc_size_row) + 287 vc->vc_size_row - 2; 288 break; 289 case TIOCL_SELPOINTER: 290 highlight_pointer(pe); 291 return 0; 292 default: 293 return -EINVAL; 294 } 295 296 /* remove the pointer */ 297 highlight_pointer(-1); 298 299 /* select to end of line if on trailing space */ 300 if (new_sel_end > new_sel_start && 301 !atedge(new_sel_end, vc->vc_size_row) && 302 is_space_on_vt(sel_pos(new_sel_end, unicode))) { 303 for (pe = new_sel_end + 2; ; pe += 2) 304 if (!is_space_on_vt(sel_pos(pe, unicode)) || 305 atedge(pe, vc->vc_size_row)) 306 break; 307 if (is_space_on_vt(sel_pos(pe, unicode))) 308 new_sel_end = pe; 309 } 310 if (vc_sel.start == -1) /* no current selection */ 311 highlight(new_sel_start, new_sel_end); 312 else if (new_sel_start == vc_sel.start) 313 { 314 if (new_sel_end == vc_sel.end) /* no action required */ 315 return 0; 316 else if (new_sel_end > vc_sel.end) /* extend to right */ 317 highlight(vc_sel.end + 2, new_sel_end); 318 else /* contract from right */ 319 highlight(new_sel_end + 2, vc_sel.end); 320 } 321 else if (new_sel_end == vc_sel.end) 322 { 323 if (new_sel_start < vc_sel.start) /* extend to left */ 324 highlight(new_sel_start, vc_sel.start - 2); 325 else /* contract from left */ 326 highlight(vc_sel.start, new_sel_start - 2); 327 } 328 else /* some other case; start selection from scratch */ 329 { 330 clear_selection(); 331 highlight(new_sel_start, new_sel_end); 332 } 333 vc_sel.start = new_sel_start; 334 vc_sel.end = new_sel_end; 335 336 return vc_selection_store_chars(vc, unicode); 337 } 338 339 static int vc_selection(struct vc_data *vc, struct tiocl_selection *v, 340 struct tty_struct *tty) 341 { 342 int ps, pe; 343 344 poke_blanked_console(); 345 346 if (v->sel_mode == TIOCL_SELCLEAR) { 347 /* useful for screendump without selection highlights */ 348 clear_selection(); 349 return 0; 350 } 351 352 v->xs = min_t(u16, v->xs - 1, vc->vc_cols - 1); 353 v->ys = min_t(u16, v->ys - 1, vc->vc_rows - 1); 354 v->xe = min_t(u16, v->xe - 1, vc->vc_cols - 1); 355 v->ye = min_t(u16, v->ye - 1, vc->vc_rows - 1); 356 357 if (mouse_reporting() && (v->sel_mode & TIOCL_SELMOUSEREPORT)) { 358 mouse_report(tty, v->sel_mode & TIOCL_SELBUTTONMASK, v->xs, 359 v->ys); 360 return 0; 361 } 362 363 ps = v->ys * vc->vc_size_row + (v->xs << 1); 364 pe = v->ye * vc->vc_size_row + (v->xe << 1); 365 if (ps > pe) /* make vc_sel.start <= vc_sel.end */ 366 swap(ps, pe); 367 368 if (vc_sel.cons != vc) { 369 clear_selection(); 370 vc_sel.cons = vc; 371 } 372 373 return vc_do_selection(vc, v->sel_mode, ps, pe); 374 } 375 376 int set_selection_kernel(struct tiocl_selection *v, struct tty_struct *tty) 377 { 378 int ret; 379 380 mutex_lock(&vc_sel.lock); 381 console_lock(); 382 ret = vc_selection(vc_cons[fg_console].d, v, tty); 383 console_unlock(); 384 mutex_unlock(&vc_sel.lock); 385 386 return ret; 387 } 388 EXPORT_SYMBOL_GPL(set_selection_kernel); 389 390 /* Insert the contents of the selection buffer into the 391 * queue of the tty associated with the current console. 392 * Invoked by ioctl(). 393 * 394 * Locking: called without locks. Calls the ldisc wrongly with 395 * unsafe methods, 396 */ 397 int paste_selection(struct tty_struct *tty) 398 { 399 struct vc_data *vc = tty->driver_data; 400 int pasted = 0; 401 size_t count; 402 struct tty_ldisc *ld; 403 DECLARE_WAITQUEUE(wait, current); 404 int ret = 0; 405 406 console_lock(); 407 poke_blanked_console(); 408 console_unlock(); 409 410 ld = tty_ldisc_ref_wait(tty); 411 if (!ld) 412 return -EIO; /* ldisc was hung up */ 413 tty_buffer_lock_exclusive(&vc->port); 414 415 add_wait_queue(&vc->paste_wait, &wait); 416 mutex_lock(&vc_sel.lock); 417 while (vc_sel.buffer && vc_sel.buf_len > pasted) { 418 set_current_state(TASK_INTERRUPTIBLE); 419 if (signal_pending(current)) { 420 ret = -EINTR; 421 break; 422 } 423 if (tty_throttled(tty)) { 424 mutex_unlock(&vc_sel.lock); 425 schedule(); 426 mutex_lock(&vc_sel.lock); 427 continue; 428 } 429 __set_current_state(TASK_RUNNING); 430 count = vc_sel.buf_len - pasted; 431 count = tty_ldisc_receive_buf(ld, vc_sel.buffer + pasted, NULL, 432 count); 433 pasted += count; 434 } 435 mutex_unlock(&vc_sel.lock); 436 remove_wait_queue(&vc->paste_wait, &wait); 437 __set_current_state(TASK_RUNNING); 438 439 tty_buffer_unlock_exclusive(&vc->port); 440 tty_ldisc_deref(ld); 441 return ret; 442 } 443 EXPORT_SYMBOL_GPL(paste_selection); 444