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 isspace(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, 1); 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 * set 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 __set_selection_kernel(struct tiocl_selection *v, struct tty_struct *tty) 189 { 190 struct vc_data *vc = vc_cons[fg_console].d; 191 int new_sel_start, new_sel_end, spc; 192 char *bp, *obp; 193 int i, ps, pe; 194 u32 c; 195 int ret = 0; 196 bool unicode; 197 198 poke_blanked_console(); 199 200 v->xs = min_t(u16, v->xs - 1, vc->vc_cols - 1); 201 v->ys = min_t(u16, v->ys - 1, vc->vc_rows - 1); 202 v->xe = min_t(u16, v->xe - 1, vc->vc_cols - 1); 203 v->ye = min_t(u16, v->ye - 1, vc->vc_rows - 1); 204 ps = v->ys * vc->vc_size_row + (v->xs << 1); 205 pe = v->ye * vc->vc_size_row + (v->xe << 1); 206 207 if (v->sel_mode == TIOCL_SELCLEAR) { 208 /* useful for screendump without selection highlights */ 209 clear_selection(); 210 return 0; 211 } 212 213 if (mouse_reporting() && (v->sel_mode & TIOCL_SELMOUSEREPORT)) { 214 mouse_report(tty, v->sel_mode & TIOCL_SELBUTTONMASK, v->xs, 215 v->ys); 216 return 0; 217 } 218 219 if (ps > pe) /* make vc_sel.start <= vc_sel.end */ 220 swap(ps, pe); 221 222 if (vc_sel.cons != vc_cons[fg_console].d) { 223 clear_selection(); 224 vc_sel.cons = vc_cons[fg_console].d; 225 } 226 unicode = vt_do_kdgkbmode(fg_console) == K_UNICODE; 227 228 switch (v->sel_mode) { 229 case TIOCL_SELCHAR: /* character-by-character selection */ 230 new_sel_start = ps; 231 new_sel_end = pe; 232 break; 233 case TIOCL_SELWORD: /* word-by-word selection */ 234 spc = isspace(sel_pos(ps, unicode)); 235 for (new_sel_start = ps; ; ps -= 2) { 236 if ((spc && !isspace(sel_pos(ps, unicode))) || 237 (!spc && !inword(sel_pos(ps, unicode)))) 238 break; 239 new_sel_start = ps; 240 if (!(ps % vc->vc_size_row)) 241 break; 242 } 243 244 spc = isspace(sel_pos(pe, unicode)); 245 for (new_sel_end = pe; ; pe += 2) { 246 if ((spc && !isspace(sel_pos(pe, unicode))) || 247 (!spc && !inword(sel_pos(pe, unicode)))) 248 break; 249 new_sel_end = pe; 250 if (!((pe + 2) % vc->vc_size_row)) 251 break; 252 } 253 break; 254 case TIOCL_SELLINE: /* line-by-line selection */ 255 new_sel_start = ps - ps % vc->vc_size_row; 256 new_sel_end = pe + vc->vc_size_row 257 - pe % vc->vc_size_row - 2; 258 break; 259 case TIOCL_SELPOINTER: 260 highlight_pointer(pe); 261 return 0; 262 default: 263 return -EINVAL; 264 } 265 266 /* remove the pointer */ 267 highlight_pointer(-1); 268 269 /* select to end of line if on trailing space */ 270 if (new_sel_end > new_sel_start && 271 !atedge(new_sel_end, vc->vc_size_row) && 272 isspace(sel_pos(new_sel_end, unicode))) { 273 for (pe = new_sel_end + 2; ; pe += 2) 274 if (!isspace(sel_pos(pe, unicode)) || 275 atedge(pe, vc->vc_size_row)) 276 break; 277 if (isspace(sel_pos(pe, unicode))) 278 new_sel_end = pe; 279 } 280 if (vc_sel.start == -1) /* no current selection */ 281 highlight(new_sel_start, new_sel_end); 282 else if (new_sel_start == vc_sel.start) 283 { 284 if (new_sel_end == vc_sel.end) /* no action required */ 285 return 0; 286 else if (new_sel_end > vc_sel.end) /* extend to right */ 287 highlight(vc_sel.end + 2, new_sel_end); 288 else /* contract from right */ 289 highlight(new_sel_end + 2, vc_sel.end); 290 } 291 else if (new_sel_end == vc_sel.end) 292 { 293 if (new_sel_start < vc_sel.start) /* extend to left */ 294 highlight(new_sel_start, vc_sel.start - 2); 295 else /* contract from left */ 296 highlight(vc_sel.start, new_sel_start - 2); 297 } 298 else /* some other case; start selection from scratch */ 299 { 300 clear_selection(); 301 highlight(new_sel_start, new_sel_end); 302 } 303 vc_sel.start = new_sel_start; 304 vc_sel.end = new_sel_end; 305 306 /* Allocate a new buffer before freeing the old one ... */ 307 /* chars can take up to 4 bytes with unicode */ 308 bp = kmalloc_array((vc_sel.end - vc_sel.start) / 2 + 1, unicode ? 4 : 1, 309 GFP_KERNEL); 310 if (!bp) { 311 printk(KERN_WARNING "selection: kmalloc() failed\n"); 312 clear_selection(); 313 return -ENOMEM; 314 } 315 kfree(vc_sel.buffer); 316 vc_sel.buffer = bp; 317 318 obp = bp; 319 for (i = vc_sel.start; i <= vc_sel.end; i += 2) { 320 c = sel_pos(i, unicode); 321 if (unicode) 322 bp += store_utf8(c, bp); 323 else 324 *bp++ = c; 325 if (!isspace(c)) 326 obp = bp; 327 if (! ((i + 2) % vc->vc_size_row)) { 328 /* strip trailing blanks from line and add newline, 329 unless non-space at end of line. */ 330 if (obp != bp) { 331 bp = obp; 332 *bp++ = '\r'; 333 } 334 obp = bp; 335 } 336 } 337 vc_sel.buf_len = bp - vc_sel.buffer; 338 339 return ret; 340 } 341 342 int set_selection_kernel(struct tiocl_selection *v, struct tty_struct *tty) 343 { 344 int ret; 345 346 mutex_lock(&vc_sel.lock); 347 console_lock(); 348 ret = __set_selection_kernel(v, tty); 349 console_unlock(); 350 mutex_unlock(&vc_sel.lock); 351 352 return ret; 353 } 354 EXPORT_SYMBOL_GPL(set_selection_kernel); 355 356 /* Insert the contents of the selection buffer into the 357 * queue of the tty associated with the current console. 358 * Invoked by ioctl(). 359 * 360 * Locking: called without locks. Calls the ldisc wrongly with 361 * unsafe methods, 362 */ 363 int paste_selection(struct tty_struct *tty) 364 { 365 struct vc_data *vc = tty->driver_data; 366 int pasted = 0; 367 unsigned int count; 368 struct tty_ldisc *ld; 369 DECLARE_WAITQUEUE(wait, current); 370 int ret = 0; 371 372 console_lock(); 373 poke_blanked_console(); 374 console_unlock(); 375 376 ld = tty_ldisc_ref_wait(tty); 377 if (!ld) 378 return -EIO; /* ldisc was hung up */ 379 tty_buffer_lock_exclusive(&vc->port); 380 381 add_wait_queue(&vc->paste_wait, &wait); 382 mutex_lock(&vc_sel.lock); 383 while (vc_sel.buffer && vc_sel.buf_len > pasted) { 384 set_current_state(TASK_INTERRUPTIBLE); 385 if (signal_pending(current)) { 386 ret = -EINTR; 387 break; 388 } 389 if (tty_throttled(tty)) { 390 mutex_unlock(&vc_sel.lock); 391 schedule(); 392 mutex_lock(&vc_sel.lock); 393 continue; 394 } 395 __set_current_state(TASK_RUNNING); 396 count = vc_sel.buf_len - pasted; 397 count = tty_ldisc_receive_buf(ld, vc_sel.buffer + pasted, NULL, 398 count); 399 pasted += count; 400 } 401 mutex_unlock(&vc_sel.lock); 402 remove_wait_queue(&vc->paste_wait, &wait); 403 __set_current_state(TASK_RUNNING); 404 405 tty_buffer_unlock_exclusive(&vc->port); 406 tty_ldisc_deref(ld); 407 return ret; 408 } 409 EXPORT_SYMBOL_GPL(paste_selection); 410