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/slab.h> 20 #include <linux/types.h> 21 22 #include <linux/uaccess.h> 23 24 #include <linux/kbd_kern.h> 25 #include <linux/vt_kern.h> 26 #include <linux/consolemap.h> 27 #include <linux/selection.h> 28 #include <linux/tiocl.h> 29 #include <linux/console.h> 30 #include <linux/tty_flip.h> 31 32 /* Don't take this from <ctype.h>: 011-015 on the screen aren't spaces */ 33 #define isspace(c) ((c) == ' ') 34 35 extern void poke_blanked_console(void); 36 37 /* FIXME: all this needs locking */ 38 /* Variables for selection control. */ 39 /* Use a dynamic buffer, instead of static (Dec 1994) */ 40 struct vc_data *sel_cons; /* must not be deallocated */ 41 static int use_unicode; 42 static volatile int sel_start = -1; /* cleared by clear_selection */ 43 static int sel_end; 44 static int sel_buffer_lth; 45 static char *sel_buffer; 46 47 /* clear_selection, highlight and highlight_pointer can be called 48 from interrupt (via scrollback/front) */ 49 50 /* set reverse video on characters s-e of console with selection. */ 51 static inline void highlight(const int s, const int e) 52 { 53 invert_screen(sel_cons, s, e-s+2, 1); 54 } 55 56 /* use complementary color to show the pointer */ 57 static inline void highlight_pointer(const int where) 58 { 59 complement_pos(sel_cons, where); 60 } 61 62 static u32 63 sel_pos(int n) 64 { 65 if (use_unicode) 66 return screen_glyph_unicode(sel_cons, n / 2); 67 return inverse_translate(sel_cons, screen_glyph(sel_cons, n), 68 0); 69 } 70 71 /** 72 * clear_selection - remove current selection 73 * 74 * Remove the current selection highlight, if any from the console 75 * holding the selection. The caller must hold the console lock. 76 */ 77 void clear_selection(void) 78 { 79 highlight_pointer(-1); /* hide the pointer */ 80 if (sel_start != -1) { 81 highlight(sel_start, sel_end); 82 sel_start = -1; 83 } 84 } 85 EXPORT_SYMBOL_GPL(clear_selection); 86 87 /* 88 * User settable table: what characters are to be considered alphabetic? 89 * 128 bits. Locked by the console lock. 90 */ 91 static u32 inwordLut[]={ 92 0x00000000, /* control chars */ 93 0x03FFE000, /* digits and "-./" */ 94 0x87FFFFFE, /* uppercase and '_' */ 95 0x07FFFFFE, /* lowercase */ 96 }; 97 98 static inline int inword(const u32 c) 99 { 100 return c > 0x7f || (( inwordLut[c>>5] >> (c & 0x1F) ) & 1); 101 } 102 103 /** 104 * set loadlut - load the LUT table 105 * @p: user table 106 * 107 * Load the LUT table from user space. The caller must hold the console 108 * lock. Make a temporary copy so a partial update doesn't make a mess. 109 */ 110 int sel_loadlut(char __user *p) 111 { 112 u32 tmplut[ARRAY_SIZE(inwordLut)]; 113 if (copy_from_user(tmplut, (u32 __user *)(p+4), sizeof(inwordLut))) 114 return -EFAULT; 115 memcpy(inwordLut, tmplut, sizeof(inwordLut)); 116 return 0; 117 } 118 119 /* does screen address p correspond to character at LH/RH edge of screen? */ 120 static inline int atedge(const int p, int size_row) 121 { 122 return (!(p % size_row) || !((p + 2) % size_row)); 123 } 124 125 /* stores the char in UTF8 and returns the number of bytes used (1-4) */ 126 static int store_utf8(u32 c, char *p) 127 { 128 if (c < 0x80) { 129 /* 0******* */ 130 p[0] = c; 131 return 1; 132 } else if (c < 0x800) { 133 /* 110***** 10****** */ 134 p[0] = 0xc0 | (c >> 6); 135 p[1] = 0x80 | (c & 0x3f); 136 return 2; 137 } else if (c < 0x10000) { 138 /* 1110**** 10****** 10****** */ 139 p[0] = 0xe0 | (c >> 12); 140 p[1] = 0x80 | ((c >> 6) & 0x3f); 141 p[2] = 0x80 | (c & 0x3f); 142 return 3; 143 } else if (c < 0x110000) { 144 /* 11110*** 10****** 10****** 10****** */ 145 p[0] = 0xf0 | (c >> 18); 146 p[1] = 0x80 | ((c >> 12) & 0x3f); 147 p[2] = 0x80 | ((c >> 6) & 0x3f); 148 p[3] = 0x80 | (c & 0x3f); 149 return 4; 150 } else { 151 /* outside Unicode, replace with U+FFFD */ 152 p[0] = 0xef; 153 p[1] = 0xbf; 154 p[2] = 0xbd; 155 return 3; 156 } 157 } 158 159 /** 160 * set_selection_user - set the current selection. 161 * @sel: user selection info 162 * @tty: the console tty 163 * 164 * Invoked by the ioctl handle for the vt layer. 165 * 166 * The entire selection process is managed under the console_lock. It's 167 * a lot under the lock but its hardly a performance path 168 */ 169 int set_selection_user(const struct tiocl_selection __user *sel, 170 struct tty_struct *tty) 171 { 172 struct tiocl_selection v; 173 174 if (copy_from_user(&v, sel, sizeof(*sel))) 175 return -EFAULT; 176 177 return set_selection_kernel(&v, tty); 178 } 179 180 int set_selection_kernel(struct tiocl_selection *v, struct tty_struct *tty) 181 { 182 struct vc_data *vc = vc_cons[fg_console].d; 183 int new_sel_start, new_sel_end, spc; 184 char *bp, *obp; 185 int i, ps, pe, multiplier; 186 u32 c; 187 int mode; 188 189 poke_blanked_console(); 190 191 v->xs = min_t(u16, v->xs - 1, vc->vc_cols - 1); 192 v->ys = min_t(u16, v->ys - 1, vc->vc_rows - 1); 193 v->xe = min_t(u16, v->xe - 1, vc->vc_cols - 1); 194 v->ye = min_t(u16, v->ye - 1, vc->vc_rows - 1); 195 ps = v->ys * vc->vc_size_row + (v->xs << 1); 196 pe = v->ye * vc->vc_size_row + (v->xe << 1); 197 198 if (v->sel_mode == TIOCL_SELCLEAR) { 199 /* useful for screendump without selection highlights */ 200 clear_selection(); 201 return 0; 202 } 203 204 if (mouse_reporting() && (v->sel_mode & TIOCL_SELMOUSEREPORT)) { 205 mouse_report(tty, v->sel_mode & TIOCL_SELBUTTONMASK, v->xs, 206 v->ys); 207 return 0; 208 } 209 210 if (ps > pe) /* make sel_start <= sel_end */ 211 swap(ps, pe); 212 213 if (sel_cons != vc_cons[fg_console].d) { 214 clear_selection(); 215 sel_cons = vc_cons[fg_console].d; 216 } 217 mode = vt_do_kdgkbmode(fg_console); 218 if (mode == K_UNICODE) 219 use_unicode = 1; 220 else 221 use_unicode = 0; 222 223 switch (v->sel_mode) 224 { 225 case TIOCL_SELCHAR: /* character-by-character selection */ 226 new_sel_start = ps; 227 new_sel_end = pe; 228 break; 229 case TIOCL_SELWORD: /* word-by-word selection */ 230 spc = isspace(sel_pos(ps)); 231 for (new_sel_start = ps; ; ps -= 2) 232 { 233 if ((spc && !isspace(sel_pos(ps))) || 234 (!spc && !inword(sel_pos(ps)))) 235 break; 236 new_sel_start = ps; 237 if (!(ps % vc->vc_size_row)) 238 break; 239 } 240 spc = isspace(sel_pos(pe)); 241 for (new_sel_end = pe; ; pe += 2) 242 { 243 if ((spc && !isspace(sel_pos(pe))) || 244 (!spc && !inword(sel_pos(pe)))) 245 break; 246 new_sel_end = pe; 247 if (!((pe + 2) % vc->vc_size_row)) 248 break; 249 } 250 break; 251 case TIOCL_SELLINE: /* line-by-line selection */ 252 new_sel_start = ps - ps % vc->vc_size_row; 253 new_sel_end = pe + vc->vc_size_row 254 - pe % vc->vc_size_row - 2; 255 break; 256 case TIOCL_SELPOINTER: 257 highlight_pointer(pe); 258 return 0; 259 default: 260 return -EINVAL; 261 } 262 263 /* remove the pointer */ 264 highlight_pointer(-1); 265 266 /* select to end of line if on trailing space */ 267 if (new_sel_end > new_sel_start && 268 !atedge(new_sel_end, vc->vc_size_row) && 269 isspace(sel_pos(new_sel_end))) { 270 for (pe = new_sel_end + 2; ; pe += 2) 271 if (!isspace(sel_pos(pe)) || 272 atedge(pe, vc->vc_size_row)) 273 break; 274 if (isspace(sel_pos(pe))) 275 new_sel_end = pe; 276 } 277 if (sel_start == -1) /* no current selection */ 278 highlight(new_sel_start, new_sel_end); 279 else if (new_sel_start == sel_start) 280 { 281 if (new_sel_end == sel_end) /* no action required */ 282 return 0; 283 else if (new_sel_end > sel_end) /* extend to right */ 284 highlight(sel_end + 2, new_sel_end); 285 else /* contract from right */ 286 highlight(new_sel_end + 2, sel_end); 287 } 288 else if (new_sel_end == sel_end) 289 { 290 if (new_sel_start < sel_start) /* extend to left */ 291 highlight(new_sel_start, sel_start - 2); 292 else /* contract from left */ 293 highlight(sel_start, new_sel_start - 2); 294 } 295 else /* some other case; start selection from scratch */ 296 { 297 clear_selection(); 298 highlight(new_sel_start, new_sel_end); 299 } 300 sel_start = new_sel_start; 301 sel_end = new_sel_end; 302 303 /* Allocate a new buffer before freeing the old one ... */ 304 multiplier = use_unicode ? 4 : 1; /* chars can take up to 4 bytes */ 305 bp = kmalloc_array((sel_end - sel_start) / 2 + 1, multiplier, 306 GFP_KERNEL); 307 if (!bp) { 308 printk(KERN_WARNING "selection: kmalloc() failed\n"); 309 clear_selection(); 310 return -ENOMEM; 311 } 312 kfree(sel_buffer); 313 sel_buffer = bp; 314 315 obp = bp; 316 for (i = sel_start; i <= sel_end; i += 2) { 317 c = sel_pos(i); 318 if (use_unicode) 319 bp += store_utf8(c, bp); 320 else 321 *bp++ = c; 322 if (!isspace(c)) 323 obp = bp; 324 if (! ((i + 2) % vc->vc_size_row)) { 325 /* strip trailing blanks from line and add newline, 326 unless non-space at end of line. */ 327 if (obp != bp) { 328 bp = obp; 329 *bp++ = '\r'; 330 } 331 obp = bp; 332 } 333 } 334 sel_buffer_lth = bp - sel_buffer; 335 return 0; 336 } 337 EXPORT_SYMBOL_GPL(set_selection_kernel); 338 339 /* Insert the contents of the selection buffer into the 340 * queue of the tty associated with the current console. 341 * Invoked by ioctl(). 342 * 343 * Locking: called without locks. Calls the ldisc wrongly with 344 * unsafe methods, 345 */ 346 int paste_selection(struct tty_struct *tty) 347 { 348 struct vc_data *vc = tty->driver_data; 349 int pasted = 0; 350 unsigned int count; 351 struct tty_ldisc *ld; 352 DECLARE_WAITQUEUE(wait, current); 353 354 console_lock(); 355 poke_blanked_console(); 356 console_unlock(); 357 358 ld = tty_ldisc_ref_wait(tty); 359 if (!ld) 360 return -EIO; /* ldisc was hung up */ 361 tty_buffer_lock_exclusive(&vc->port); 362 363 add_wait_queue(&vc->paste_wait, &wait); 364 while (sel_buffer && sel_buffer_lth > pasted) { 365 set_current_state(TASK_INTERRUPTIBLE); 366 if (tty_throttled(tty)) { 367 schedule(); 368 continue; 369 } 370 __set_current_state(TASK_RUNNING); 371 count = sel_buffer_lth - pasted; 372 count = tty_ldisc_receive_buf(ld, sel_buffer + pasted, NULL, 373 count); 374 pasted += count; 375 } 376 remove_wait_queue(&vc->paste_wait, &wait); 377 __set_current_state(TASK_RUNNING); 378 379 tty_buffer_unlock_exclusive(&vc->port); 380 tty_ldisc_deref(ld); 381 return 0; 382 } 383 EXPORT_SYMBOL_GPL(paste_selection); 384