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, TIOCL_SELPOINTER and TIOCL_SELMOUSEREPORT are OK to 197 * use without 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 case TIOCL_SELMOUSEREPORT: 203 break; 204 default: 205 if (!capable(CAP_SYS_ADMIN)) 206 return -EPERM; 207 } 208 209 return set_selection_kernel(&v, tty); 210 } 211 212 static int vc_selection_store_chars(struct vc_data *vc, bool unicode) 213 { 214 char *bp, *obp; 215 unsigned int i; 216 217 /* Allocate a new buffer before freeing the old one ... */ 218 /* chars can take up to 4 bytes with unicode */ 219 bp = kmalloc_array((vc_sel.end - vc_sel.start) / 2 + 1, unicode ? 4 : 1, 220 GFP_KERNEL | __GFP_NOWARN); 221 if (!bp) { 222 printk(KERN_WARNING "selection: kmalloc() failed\n"); 223 clear_selection(); 224 return -ENOMEM; 225 } 226 kfree(vc_sel.buffer); 227 vc_sel.buffer = bp; 228 229 obp = bp; 230 for (i = vc_sel.start; i <= vc_sel.end; i += 2) { 231 u32 c = sel_pos(i, unicode); 232 if (unicode) 233 bp += store_utf8(c, bp); 234 else 235 *bp++ = c; 236 if (!is_space_on_vt(c)) 237 obp = bp; 238 if (!((i + 2) % vc->vc_size_row)) { 239 /* strip trailing blanks from line and add newline, 240 unless non-space at end of line. */ 241 if (obp != bp) { 242 bp = obp; 243 *bp++ = '\r'; 244 } 245 obp = bp; 246 } 247 } 248 vc_sel.buf_len = bp - vc_sel.buffer; 249 250 return 0; 251 } 252 253 static int vc_do_selection(struct vc_data *vc, unsigned short mode, int ps, 254 int pe) 255 { 256 int new_sel_start, new_sel_end, spc; 257 bool unicode = vt_do_kdgkbmode(fg_console) == K_UNICODE; 258 259 switch (mode) { 260 case TIOCL_SELCHAR: /* character-by-character selection */ 261 new_sel_start = ps; 262 new_sel_end = pe; 263 break; 264 case TIOCL_SELWORD: /* word-by-word selection */ 265 spc = is_space_on_vt(sel_pos(ps, unicode)); 266 for (new_sel_start = ps; ; ps -= 2) { 267 if ((spc && !is_space_on_vt(sel_pos(ps, unicode))) || 268 (!spc && !inword(sel_pos(ps, unicode)))) 269 break; 270 new_sel_start = ps; 271 if (!(ps % vc->vc_size_row)) 272 break; 273 } 274 275 spc = is_space_on_vt(sel_pos(pe, unicode)); 276 for (new_sel_end = pe; ; pe += 2) { 277 if ((spc && !is_space_on_vt(sel_pos(pe, unicode))) || 278 (!spc && !inword(sel_pos(pe, unicode)))) 279 break; 280 new_sel_end = pe; 281 if (!((pe + 2) % vc->vc_size_row)) 282 break; 283 } 284 break; 285 case TIOCL_SELLINE: /* line-by-line selection */ 286 new_sel_start = rounddown(ps, vc->vc_size_row); 287 new_sel_end = rounddown(pe, vc->vc_size_row) + 288 vc->vc_size_row - 2; 289 break; 290 case TIOCL_SELPOINTER: 291 highlight_pointer(pe); 292 return 0; 293 default: 294 return -EINVAL; 295 } 296 297 /* remove the pointer */ 298 highlight_pointer(-1); 299 300 /* select to end of line if on trailing space */ 301 if (new_sel_end > new_sel_start && 302 !atedge(new_sel_end, vc->vc_size_row) && 303 is_space_on_vt(sel_pos(new_sel_end, unicode))) { 304 for (pe = new_sel_end + 2; ; pe += 2) 305 if (!is_space_on_vt(sel_pos(pe, unicode)) || 306 atedge(pe, vc->vc_size_row)) 307 break; 308 if (is_space_on_vt(sel_pos(pe, unicode))) 309 new_sel_end = pe; 310 } 311 if (vc_sel.start == -1) /* no current selection */ 312 highlight(new_sel_start, new_sel_end); 313 else if (new_sel_start == vc_sel.start) 314 { 315 if (new_sel_end == vc_sel.end) /* no action required */ 316 return 0; 317 else if (new_sel_end > vc_sel.end) /* extend to right */ 318 highlight(vc_sel.end + 2, new_sel_end); 319 else /* contract from right */ 320 highlight(new_sel_end + 2, vc_sel.end); 321 } 322 else if (new_sel_end == vc_sel.end) 323 { 324 if (new_sel_start < vc_sel.start) /* extend to left */ 325 highlight(new_sel_start, vc_sel.start - 2); 326 else /* contract from left */ 327 highlight(vc_sel.start, new_sel_start - 2); 328 } 329 else /* some other case; start selection from scratch */ 330 { 331 clear_selection(); 332 highlight(new_sel_start, new_sel_end); 333 } 334 vc_sel.start = new_sel_start; 335 vc_sel.end = new_sel_end; 336 337 return vc_selection_store_chars(vc, unicode); 338 } 339 340 static int vc_selection(struct vc_data *vc, struct tiocl_selection *v, 341 struct tty_struct *tty) 342 { 343 int ps, pe; 344 345 poke_blanked_console(); 346 347 if (v->sel_mode == TIOCL_SELCLEAR) { 348 /* useful for screendump without selection highlights */ 349 clear_selection(); 350 return 0; 351 } 352 353 v->xs = min_t(u16, v->xs - 1, vc->vc_cols - 1); 354 v->ys = min_t(u16, v->ys - 1, vc->vc_rows - 1); 355 v->xe = min_t(u16, v->xe - 1, vc->vc_cols - 1); 356 v->ye = min_t(u16, v->ye - 1, vc->vc_rows - 1); 357 358 if (mouse_reporting() && (v->sel_mode & TIOCL_SELMOUSEREPORT)) { 359 mouse_report(tty, v->sel_mode & TIOCL_SELBUTTONMASK, v->xs, 360 v->ys); 361 return 0; 362 } 363 364 ps = v->ys * vc->vc_size_row + (v->xs << 1); 365 pe = v->ye * vc->vc_size_row + (v->xe << 1); 366 if (ps > pe) /* make vc_sel.start <= vc_sel.end */ 367 swap(ps, pe); 368 369 if (vc_sel.cons != vc) { 370 clear_selection(); 371 vc_sel.cons = vc; 372 } 373 374 return vc_do_selection(vc, v->sel_mode, ps, pe); 375 } 376 377 int set_selection_kernel(struct tiocl_selection *v, struct tty_struct *tty) 378 { 379 int ret; 380 381 mutex_lock(&vc_sel.lock); 382 console_lock(); 383 ret = vc_selection(vc_cons[fg_console].d, v, tty); 384 console_unlock(); 385 mutex_unlock(&vc_sel.lock); 386 387 return ret; 388 } 389 EXPORT_SYMBOL_GPL(set_selection_kernel); 390 391 /* Insert the contents of the selection buffer into the 392 * queue of the tty associated with the current console. 393 * Invoked by ioctl(). 394 * 395 * Locking: called without locks. Calls the ldisc wrongly with 396 * unsafe methods, 397 */ 398 int paste_selection(struct tty_struct *tty) 399 { 400 struct vc_data *vc = tty->driver_data; 401 int pasted = 0; 402 size_t count; 403 struct tty_ldisc *ld; 404 DECLARE_WAITQUEUE(wait, current); 405 int ret = 0; 406 407 console_lock(); 408 poke_blanked_console(); 409 console_unlock(); 410 411 ld = tty_ldisc_ref_wait(tty); 412 if (!ld) 413 return -EIO; /* ldisc was hung up */ 414 tty_buffer_lock_exclusive(&vc->port); 415 416 add_wait_queue(&vc->paste_wait, &wait); 417 mutex_lock(&vc_sel.lock); 418 while (vc_sel.buffer && vc_sel.buf_len > pasted) { 419 set_current_state(TASK_INTERRUPTIBLE); 420 if (signal_pending(current)) { 421 ret = -EINTR; 422 break; 423 } 424 if (tty_throttled(tty)) { 425 mutex_unlock(&vc_sel.lock); 426 schedule(); 427 mutex_lock(&vc_sel.lock); 428 continue; 429 } 430 __set_current_state(TASK_RUNNING); 431 count = vc_sel.buf_len - pasted; 432 count = tty_ldisc_receive_buf(ld, vc_sel.buffer + pasted, NULL, 433 count); 434 pasted += count; 435 } 436 mutex_unlock(&vc_sel.lock); 437 remove_wait_queue(&vc->paste_wait, &wait); 438 __set_current_state(TASK_RUNNING); 439 440 tty_buffer_unlock_exclusive(&vc->port); 441 tty_ldisc_deref(ld); 442 return ret; 443 } 444 EXPORT_SYMBOL_GPL(paste_selection); 445