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 guard(console_lock)(); 131 memcpy(inwordLut, tmplut, sizeof(inwordLut)); 132 133 return 0; 134 } 135 136 /* does screen address p correspond to character at LH/RH edge of screen? */ 137 static inline int atedge(const int p, int size_row) 138 { 139 return (!(p % size_row) || !((p + 2) % size_row)); 140 } 141 142 /* stores the char in UTF8 and returns the number of bytes used (1-4) */ 143 static int store_utf8(u32 c, char *p) 144 { 145 if (c < 0x80) { 146 /* 0******* */ 147 p[0] = c; 148 return 1; 149 } else if (c < 0x800) { 150 /* 110***** 10****** */ 151 p[0] = 0xc0 | (c >> 6); 152 p[1] = 0x80 | (c & 0x3f); 153 return 2; 154 } else if (c < 0x10000) { 155 /* 1110**** 10****** 10****** */ 156 p[0] = 0xe0 | (c >> 12); 157 p[1] = 0x80 | ((c >> 6) & 0x3f); 158 p[2] = 0x80 | (c & 0x3f); 159 return 3; 160 } else if (c < 0x110000) { 161 /* 11110*** 10****** 10****** 10****** */ 162 p[0] = 0xf0 | (c >> 18); 163 p[1] = 0x80 | ((c >> 12) & 0x3f); 164 p[2] = 0x80 | ((c >> 6) & 0x3f); 165 p[3] = 0x80 | (c & 0x3f); 166 return 4; 167 } else { 168 /* outside Unicode, replace with U+FFFD */ 169 p[0] = 0xef; 170 p[1] = 0xbf; 171 p[2] = 0xbd; 172 return 3; 173 } 174 } 175 176 /** 177 * set_selection_user - set the current selection. 178 * @sel: user selection info 179 * @tty: the console tty 180 * 181 * Invoked by the ioctl handle for the vt layer. 182 * 183 * Locking: The entire selection process is managed under the console_lock. 184 * It's a lot under the lock but its hardly a performance path. 185 */ 186 int set_selection_user(const struct tiocl_selection __user *sel, 187 struct tty_struct *tty) 188 { 189 struct tiocl_selection v; 190 191 if (copy_from_user(&v, sel, sizeof(*sel))) 192 return -EFAULT; 193 194 /* 195 * TIOCL_SELCLEAR and TIOCL_SELPOINTER are OK to use without 196 * CAP_SYS_ADMIN as they do not modify the selection. 197 */ 198 switch (v.sel_mode) { 199 case TIOCL_SELCLEAR: 200 case TIOCL_SELPOINTER: 201 break; 202 default: 203 if (!capable(CAP_SYS_ADMIN)) 204 return -EPERM; 205 } 206 207 return set_selection_kernel(&v, tty); 208 } 209 210 static int vc_selection_store_chars(struct vc_data *vc, bool unicode) 211 { 212 char *bp, *obp; 213 unsigned int i; 214 215 /* Allocate a new buffer before freeing the old one ... */ 216 /* chars can take up to 4 bytes with unicode */ 217 bp = kmalloc_array((vc_sel.end - vc_sel.start) / 2 + 1, unicode ? 4 : 1, 218 GFP_KERNEL | __GFP_NOWARN); 219 if (!bp) { 220 printk(KERN_WARNING "selection: kmalloc() failed\n"); 221 clear_selection(); 222 return -ENOMEM; 223 } 224 kfree(vc_sel.buffer); 225 vc_sel.buffer = bp; 226 227 obp = bp; 228 for (i = vc_sel.start; i <= vc_sel.end; i += 2) { 229 u32 c = sel_pos(i, unicode); 230 if (unicode) 231 bp += store_utf8(c, bp); 232 else 233 *bp++ = c; 234 if (!is_space_on_vt(c)) 235 obp = bp; 236 if (!((i + 2) % vc->vc_size_row)) { 237 /* strip trailing blanks from line and add newline, 238 unless non-space at end of line. */ 239 if (obp != bp) { 240 bp = obp; 241 *bp++ = '\r'; 242 } 243 obp = bp; 244 } 245 } 246 vc_sel.buf_len = bp - vc_sel.buffer; 247 248 return 0; 249 } 250 251 static int vc_do_selection(struct vc_data *vc, unsigned short mode, int ps, 252 int pe) 253 { 254 int new_sel_start, new_sel_end, spc; 255 bool unicode = vt_do_kdgkbmode(fg_console) == K_UNICODE; 256 257 switch (mode) { 258 case TIOCL_SELCHAR: /* character-by-character selection */ 259 new_sel_start = ps; 260 new_sel_end = pe; 261 break; 262 case TIOCL_SELWORD: /* word-by-word selection */ 263 spc = is_space_on_vt(sel_pos(ps, unicode)); 264 for (new_sel_start = ps; ; ps -= 2) { 265 if ((spc && !is_space_on_vt(sel_pos(ps, unicode))) || 266 (!spc && !inword(sel_pos(ps, unicode)))) 267 break; 268 new_sel_start = ps; 269 if (!(ps % vc->vc_size_row)) 270 break; 271 } 272 273 spc = is_space_on_vt(sel_pos(pe, unicode)); 274 for (new_sel_end = pe; ; pe += 2) { 275 if ((spc && !is_space_on_vt(sel_pos(pe, unicode))) || 276 (!spc && !inword(sel_pos(pe, unicode)))) 277 break; 278 new_sel_end = pe; 279 if (!((pe + 2) % vc->vc_size_row)) 280 break; 281 } 282 break; 283 case TIOCL_SELLINE: /* line-by-line selection */ 284 new_sel_start = rounddown(ps, vc->vc_size_row); 285 new_sel_end = rounddown(pe, vc->vc_size_row) + 286 vc->vc_size_row - 2; 287 break; 288 case TIOCL_SELPOINTER: 289 highlight_pointer(pe); 290 return 0; 291 default: 292 return -EINVAL; 293 } 294 295 /* remove the pointer */ 296 highlight_pointer(-1); 297 298 /* select to end of line if on trailing space */ 299 if (new_sel_end > new_sel_start && 300 !atedge(new_sel_end, vc->vc_size_row) && 301 is_space_on_vt(sel_pos(new_sel_end, unicode))) { 302 for (pe = new_sel_end + 2; ; pe += 2) 303 if (!is_space_on_vt(sel_pos(pe, unicode)) || 304 atedge(pe, vc->vc_size_row)) 305 break; 306 if (is_space_on_vt(sel_pos(pe, unicode))) 307 new_sel_end = pe; 308 } 309 if (vc_sel.start == -1) /* no current selection */ 310 highlight(new_sel_start, new_sel_end); 311 else if (new_sel_start == vc_sel.start) 312 { 313 if (new_sel_end == vc_sel.end) /* no action required */ 314 return 0; 315 else if (new_sel_end > vc_sel.end) /* extend to right */ 316 highlight(vc_sel.end + 2, new_sel_end); 317 else /* contract from right */ 318 highlight(new_sel_end + 2, vc_sel.end); 319 } 320 else if (new_sel_end == vc_sel.end) 321 { 322 if (new_sel_start < vc_sel.start) /* extend to left */ 323 highlight(new_sel_start, vc_sel.start - 2); 324 else /* contract from left */ 325 highlight(vc_sel.start, new_sel_start - 2); 326 } 327 else /* some other case; start selection from scratch */ 328 { 329 clear_selection(); 330 highlight(new_sel_start, new_sel_end); 331 } 332 vc_sel.start = new_sel_start; 333 vc_sel.end = new_sel_end; 334 335 return vc_selection_store_chars(vc, unicode); 336 } 337 338 static int vc_selection(struct vc_data *vc, struct tiocl_selection *v, 339 struct tty_struct *tty) 340 { 341 int ps, pe; 342 343 poke_blanked_console(); 344 345 if (v->sel_mode == TIOCL_SELCLEAR) { 346 /* useful for screendump without selection highlights */ 347 clear_selection(); 348 return 0; 349 } 350 351 v->xs = min_t(u16, v->xs - 1, vc->vc_cols - 1); 352 v->ys = min_t(u16, v->ys - 1, vc->vc_rows - 1); 353 v->xe = min_t(u16, v->xe - 1, vc->vc_cols - 1); 354 v->ye = min_t(u16, v->ye - 1, vc->vc_rows - 1); 355 356 if (mouse_reporting() && (v->sel_mode & TIOCL_SELMOUSEREPORT)) { 357 mouse_report(tty, v->sel_mode & TIOCL_SELBUTTONMASK, v->xs, 358 v->ys); 359 return 0; 360 } 361 362 ps = v->ys * vc->vc_size_row + (v->xs << 1); 363 pe = v->ye * vc->vc_size_row + (v->xe << 1); 364 if (ps > pe) /* make vc_sel.start <= vc_sel.end */ 365 swap(ps, pe); 366 367 if (vc_sel.cons != vc) { 368 clear_selection(); 369 vc_sel.cons = vc; 370 } 371 372 return vc_do_selection(vc, v->sel_mode, ps, pe); 373 } 374 375 int set_selection_kernel(struct tiocl_selection *v, struct tty_struct *tty) 376 { 377 guard(mutex)(&vc_sel.lock); 378 guard(console_lock)(); 379 return vc_selection(vc_cons[fg_console].d, v, tty); 380 } 381 EXPORT_SYMBOL_GPL(set_selection_kernel); 382 383 /* Insert the contents of the selection buffer into the 384 * queue of the tty associated with the current console. 385 * Invoked by ioctl(). 386 * 387 * Locking: called without locks. Calls the ldisc wrongly with 388 * unsafe methods, 389 */ 390 int paste_selection(struct tty_struct *tty) 391 { 392 struct vc_data *vc = tty->driver_data; 393 int pasted = 0; 394 size_t count; 395 struct tty_ldisc *ld; 396 DECLARE_WAITQUEUE(wait, current); 397 int ret = 0; 398 399 bool bp = vc->vc_bracketed_paste; 400 static const char bracketed_paste_start[] = "\033[200~"; 401 static const char bracketed_paste_end[] = "\033[201~"; 402 const char *bps = bp ? bracketed_paste_start : NULL; 403 const char *bpe = bp ? bracketed_paste_end : NULL; 404 405 scoped_guard(console_lock) 406 poke_blanked_console(); 407 408 ld = tty_ldisc_ref_wait(tty); 409 if (!ld) 410 return -EIO; /* ldisc was hung up */ 411 tty_buffer_lock_exclusive(&vc->port); 412 413 add_wait_queue(&vc->paste_wait, &wait); 414 mutex_lock(&vc_sel.lock); 415 while (vc_sel.buffer && (vc_sel.buf_len > pasted || bpe)) { 416 set_current_state(TASK_INTERRUPTIBLE); 417 if (signal_pending(current)) { 418 ret = -EINTR; 419 break; 420 } 421 if (tty_throttled(tty)) { 422 mutex_unlock(&vc_sel.lock); 423 schedule(); 424 mutex_lock(&vc_sel.lock); 425 continue; 426 } 427 __set_current_state(TASK_RUNNING); 428 429 if (bps) { 430 bps += tty_ldisc_receive_buf(ld, bps, NULL, strlen(bps)); 431 if (*bps != '\0') 432 continue; 433 bps = NULL; 434 } 435 436 count = vc_sel.buf_len - pasted; 437 if (count) { 438 pasted += tty_ldisc_receive_buf(ld, vc_sel.buffer + pasted, 439 NULL, count); 440 if (vc_sel.buf_len > pasted) 441 continue; 442 } 443 444 if (bpe) { 445 bpe += tty_ldisc_receive_buf(ld, bpe, NULL, strlen(bpe)); 446 if (*bpe == '\0') 447 bpe = NULL; 448 } 449 } 450 mutex_unlock(&vc_sel.lock); 451 remove_wait_queue(&vc->paste_wait, &wait); 452 __set_current_state(TASK_RUNNING); 453 454 tty_buffer_unlock_exclusive(&vc->port); 455 tty_ldisc_deref(ld); 456 return ret; 457 } 458 EXPORT_SYMBOL_GPL(paste_selection); 459