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