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 extern void poke_blanked_console(void); 39 40 /* FIXME: all this needs locking */ 41 /* Variables for selection control. */ 42 /* Use a dynamic buffer, instead of static (Dec 1994) */ 43 struct vc_data *sel_cons; /* must not be deallocated */ 44 static volatile int sel_start = -1; /* cleared by clear_selection */ 45 static int sel_end; 46 static int sel_buffer_lth; 47 static char *sel_buffer; 48 static DEFINE_MUTEX(sel_lock); 49 50 /* clear_selection, highlight and highlight_pointer can be called 51 from interrupt (via scrollback/front) */ 52 53 /* set reverse video on characters s-e of console with selection. */ 54 static inline void highlight(const int s, const int e) 55 { 56 invert_screen(sel_cons, s, e-s+2, 1); 57 } 58 59 /* use complementary color to show the pointer */ 60 static inline void highlight_pointer(const int where) 61 { 62 complement_pos(sel_cons, where); 63 } 64 65 static u32 66 sel_pos(int n, bool unicode) 67 { 68 if (unicode) 69 return screen_glyph_unicode(sel_cons, n / 2); 70 return inverse_translate(sel_cons, screen_glyph(sel_cons, n), 71 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 (sel_start != -1) { 84 highlight(sel_start, sel_end); 85 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 == 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 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 sel_start <= sel_end */ 220 swap(ps, pe); 221 222 mutex_lock(&sel_lock); 223 if (sel_cons != vc_cons[fg_console].d) { 224 clear_selection(); 225 sel_cons = vc_cons[fg_console].d; 226 } 227 unicode = vt_do_kdgkbmode(fg_console) == K_UNICODE; 228 229 switch (v->sel_mode) 230 { 231 case TIOCL_SELCHAR: /* character-by-character selection */ 232 new_sel_start = ps; 233 new_sel_end = pe; 234 break; 235 case TIOCL_SELWORD: /* word-by-word selection */ 236 spc = isspace(sel_pos(ps, unicode)); 237 for (new_sel_start = ps; ; ps -= 2) 238 { 239 if ((spc && !isspace(sel_pos(ps, unicode))) || 240 (!spc && !inword(sel_pos(ps, unicode)))) 241 break; 242 new_sel_start = ps; 243 if (!(ps % vc->vc_size_row)) 244 break; 245 } 246 spc = isspace(sel_pos(pe, unicode)); 247 for (new_sel_end = pe; ; pe += 2) 248 { 249 if ((spc && !isspace(sel_pos(pe, unicode))) || 250 (!spc && !inword(sel_pos(pe, unicode)))) 251 break; 252 new_sel_end = pe; 253 if (!((pe + 2) % vc->vc_size_row)) 254 break; 255 } 256 break; 257 case TIOCL_SELLINE: /* line-by-line selection */ 258 new_sel_start = ps - ps % vc->vc_size_row; 259 new_sel_end = pe + vc->vc_size_row 260 - pe % vc->vc_size_row - 2; 261 break; 262 case TIOCL_SELPOINTER: 263 highlight_pointer(pe); 264 goto unlock; 265 default: 266 ret = -EINVAL; 267 goto unlock; 268 } 269 270 /* remove the pointer */ 271 highlight_pointer(-1); 272 273 /* select to end of line if on trailing space */ 274 if (new_sel_end > new_sel_start && 275 !atedge(new_sel_end, vc->vc_size_row) && 276 isspace(sel_pos(new_sel_end, unicode))) { 277 for (pe = new_sel_end + 2; ; pe += 2) 278 if (!isspace(sel_pos(pe, unicode)) || 279 atedge(pe, vc->vc_size_row)) 280 break; 281 if (isspace(sel_pos(pe, unicode))) 282 new_sel_end = pe; 283 } 284 if (sel_start == -1) /* no current selection */ 285 highlight(new_sel_start, new_sel_end); 286 else if (new_sel_start == sel_start) 287 { 288 if (new_sel_end == sel_end) /* no action required */ 289 goto unlock; 290 else if (new_sel_end > sel_end) /* extend to right */ 291 highlight(sel_end + 2, new_sel_end); 292 else /* contract from right */ 293 highlight(new_sel_end + 2, sel_end); 294 } 295 else if (new_sel_end == sel_end) 296 { 297 if (new_sel_start < sel_start) /* extend to left */ 298 highlight(new_sel_start, sel_start - 2); 299 else /* contract from left */ 300 highlight(sel_start, new_sel_start - 2); 301 } 302 else /* some other case; start selection from scratch */ 303 { 304 clear_selection(); 305 highlight(new_sel_start, new_sel_end); 306 } 307 sel_start = new_sel_start; 308 sel_end = new_sel_end; 309 310 /* Allocate a new buffer before freeing the old one ... */ 311 /* chars can take up to 4 bytes with unicode */ 312 bp = kmalloc_array((sel_end - sel_start) / 2 + 1, unicode ? 4 : 1, 313 GFP_KERNEL); 314 if (!bp) { 315 printk(KERN_WARNING "selection: kmalloc() failed\n"); 316 clear_selection(); 317 ret = -ENOMEM; 318 goto unlock; 319 } 320 kfree(sel_buffer); 321 sel_buffer = bp; 322 323 obp = bp; 324 for (i = sel_start; i <= sel_end; i += 2) { 325 c = sel_pos(i, unicode); 326 if (unicode) 327 bp += store_utf8(c, bp); 328 else 329 *bp++ = c; 330 if (!isspace(c)) 331 obp = bp; 332 if (! ((i + 2) % vc->vc_size_row)) { 333 /* strip trailing blanks from line and add newline, 334 unless non-space at end of line. */ 335 if (obp != bp) { 336 bp = obp; 337 *bp++ = '\r'; 338 } 339 obp = bp; 340 } 341 } 342 sel_buffer_lth = bp - sel_buffer; 343 unlock: 344 mutex_unlock(&sel_lock); 345 return ret; 346 } 347 EXPORT_SYMBOL_GPL(set_selection_kernel); 348 349 /* Insert the contents of the selection buffer into the 350 * queue of the tty associated with the current console. 351 * Invoked by ioctl(). 352 * 353 * Locking: called without locks. Calls the ldisc wrongly with 354 * unsafe methods, 355 */ 356 int paste_selection(struct tty_struct *tty) 357 { 358 struct vc_data *vc = tty->driver_data; 359 int pasted = 0; 360 unsigned int count; 361 struct tty_ldisc *ld; 362 DECLARE_WAITQUEUE(wait, current); 363 int ret = 0; 364 365 console_lock(); 366 poke_blanked_console(); 367 console_unlock(); 368 369 ld = tty_ldisc_ref_wait(tty); 370 if (!ld) 371 return -EIO; /* ldisc was hung up */ 372 tty_buffer_lock_exclusive(&vc->port); 373 374 add_wait_queue(&vc->paste_wait, &wait); 375 mutex_lock(&sel_lock); 376 while (sel_buffer && sel_buffer_lth > pasted) { 377 set_current_state(TASK_INTERRUPTIBLE); 378 if (signal_pending(current)) { 379 ret = -EINTR; 380 break; 381 } 382 if (tty_throttled(tty)) { 383 mutex_unlock(&sel_lock); 384 schedule(); 385 mutex_lock(&sel_lock); 386 continue; 387 } 388 __set_current_state(TASK_RUNNING); 389 count = sel_buffer_lth - pasted; 390 count = tty_ldisc_receive_buf(ld, sel_buffer + pasted, NULL, 391 count); 392 pasted += count; 393 } 394 mutex_unlock(&sel_lock); 395 remove_wait_queue(&vc->paste_wait, &wait); 396 __set_current_state(TASK_RUNNING); 397 398 tty_buffer_unlock_exclusive(&vc->port); 399 tty_ldisc_deref(ld); 400 return ret; 401 } 402 EXPORT_SYMBOL_GPL(paste_selection); 403