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