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