1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * This module exports the functions: 4 * 5 * 'int set_selection(struct tiocl_selection __user *, struct tty_struct *)' 6 * 'void clear_selection(void)' 7 * 'int paste_selection(struct tty_struct *)' 8 * 'int sel_loadlut(char __user *)' 9 * 10 * Now that /dev/vcs exists, most of this can disappear again. 11 */ 12 13 #include <linux/module.h> 14 #include <linux/tty.h> 15 #include <linux/sched.h> 16 #include <linux/mm.h> 17 #include <linux/slab.h> 18 #include <linux/types.h> 19 20 #include <linux/uaccess.h> 21 22 #include <linux/kbd_kern.h> 23 #include <linux/vt_kern.h> 24 #include <linux/consolemap.h> 25 #include <linux/selection.h> 26 #include <linux/tiocl.h> 27 #include <linux/console.h> 28 #include <linux/tty_flip.h> 29 30 /* Don't take this from <ctype.h>: 011-015 on the screen aren't spaces */ 31 #define isspace(c) ((c) == ' ') 32 33 extern void poke_blanked_console(void); 34 35 /* FIXME: all this needs locking */ 36 /* Variables for selection control. */ 37 /* Use a dynamic buffer, instead of static (Dec 1994) */ 38 struct vc_data *sel_cons; /* must not be deallocated */ 39 static int use_unicode; 40 static volatile int sel_start = -1; /* cleared by clear_selection */ 41 static int sel_end; 42 static int sel_buffer_lth; 43 static char *sel_buffer; 44 45 /* clear_selection, highlight and highlight_pointer can be called 46 from interrupt (via scrollback/front) */ 47 48 /* set reverse video on characters s-e of console with selection. */ 49 static inline void highlight(const int s, const int e) 50 { 51 invert_screen(sel_cons, s, e-s+2, 1); 52 } 53 54 /* use complementary color to show the pointer */ 55 static inline void highlight_pointer(const int where) 56 { 57 complement_pos(sel_cons, where); 58 } 59 60 static u32 61 sel_pos(int n) 62 { 63 if (use_unicode) 64 return screen_glyph_unicode(sel_cons, n / 2); 65 return inverse_translate(sel_cons, screen_glyph(sel_cons, n), 66 0); 67 } 68 69 /** 70 * clear_selection - remove current selection 71 * 72 * Remove the current selection highlight, if any from the console 73 * holding the selection. The caller must hold the console lock. 74 */ 75 void clear_selection(void) 76 { 77 highlight_pointer(-1); /* hide the pointer */ 78 if (sel_start != -1) { 79 highlight(sel_start, sel_end); 80 sel_start = -1; 81 } 82 } 83 84 /* 85 * User settable table: what characters are to be considered alphabetic? 86 * 128 bits. Locked by the console lock. 87 */ 88 static u32 inwordLut[]={ 89 0x00000000, /* control chars */ 90 0x03FFE000, /* digits and "-./" */ 91 0x87FFFFFE, /* uppercase and '_' */ 92 0x07FFFFFE, /* lowercase */ 93 }; 94 95 static inline int inword(const u32 c) 96 { 97 return c > 0x7f || (( inwordLut[c>>5] >> (c & 0x1F) ) & 1); 98 } 99 100 /** 101 * set loadlut - load the LUT table 102 * @p: user table 103 * 104 * Load the LUT table from user space. The caller must hold the console 105 * lock. Make a temporary copy so a partial update doesn't make a mess. 106 */ 107 int sel_loadlut(char __user *p) 108 { 109 u32 tmplut[ARRAY_SIZE(inwordLut)]; 110 if (copy_from_user(tmplut, (u32 __user *)(p+4), sizeof(inwordLut))) 111 return -EFAULT; 112 memcpy(inwordLut, tmplut, sizeof(inwordLut)); 113 return 0; 114 } 115 116 /* does screen address p correspond to character at LH/RH edge of screen? */ 117 static inline int atedge(const int p, int size_row) 118 { 119 return (!(p % size_row) || !((p + 2) % size_row)); 120 } 121 122 /* stores the char in UTF8 and returns the number of bytes used (1-4) */ 123 static int store_utf8(u32 c, char *p) 124 { 125 if (c < 0x80) { 126 /* 0******* */ 127 p[0] = c; 128 return 1; 129 } else if (c < 0x800) { 130 /* 110***** 10****** */ 131 p[0] = 0xc0 | (c >> 6); 132 p[1] = 0x80 | (c & 0x3f); 133 return 2; 134 } else if (c < 0x10000) { 135 /* 1110**** 10****** 10****** */ 136 p[0] = 0xe0 | (c >> 12); 137 p[1] = 0x80 | ((c >> 6) & 0x3f); 138 p[2] = 0x80 | (c & 0x3f); 139 return 3; 140 } else if (c < 0x110000) { 141 /* 11110*** 10****** 10****** 10****** */ 142 p[0] = 0xf0 | (c >> 18); 143 p[1] = 0x80 | ((c >> 12) & 0x3f); 144 p[2] = 0x80 | ((c >> 6) & 0x3f); 145 p[3] = 0x80 | (c & 0x3f); 146 return 4; 147 } else { 148 /* outside Unicode, replace with U+FFFD */ 149 p[0] = 0xef; 150 p[1] = 0xbf; 151 p[2] = 0xbd; 152 return 3; 153 } 154 } 155 156 /** 157 * set_selection - set the current selection. 158 * @sel: user selection info 159 * @tty: the console tty 160 * 161 * Invoked by the ioctl handle for the vt layer. 162 * 163 * The entire selection process is managed under the console_lock. It's 164 * a lot under the lock but its hardly a performance path 165 */ 166 int set_selection(const struct tiocl_selection __user *sel, struct tty_struct *tty) 167 { 168 struct vc_data *vc = vc_cons[fg_console].d; 169 int new_sel_start, new_sel_end, spc; 170 struct tiocl_selection v; 171 char *bp, *obp; 172 int i, ps, pe, multiplier; 173 u32 c; 174 int mode; 175 176 poke_blanked_console(); 177 if (copy_from_user(&v, sel, sizeof(*sel))) 178 return -EFAULT; 179 180 v.xs = min_t(u16, v.xs - 1, vc->vc_cols - 1); 181 v.ys = min_t(u16, v.ys - 1, vc->vc_rows - 1); 182 v.xe = min_t(u16, v.xe - 1, vc->vc_cols - 1); 183 v.ye = min_t(u16, v.ye - 1, vc->vc_rows - 1); 184 ps = v.ys * vc->vc_size_row + (v.xs << 1); 185 pe = v.ye * vc->vc_size_row + (v.xe << 1); 186 187 if (v.sel_mode == TIOCL_SELCLEAR) { 188 /* useful for screendump without selection highlights */ 189 clear_selection(); 190 return 0; 191 } 192 193 if (mouse_reporting() && (v.sel_mode & TIOCL_SELMOUSEREPORT)) { 194 mouse_report(tty, v.sel_mode & TIOCL_SELBUTTONMASK, v.xs, v.ys); 195 return 0; 196 } 197 198 if (ps > pe) /* make sel_start <= sel_end */ 199 swap(ps, pe); 200 201 if (sel_cons != vc_cons[fg_console].d) { 202 clear_selection(); 203 sel_cons = vc_cons[fg_console].d; 204 } 205 mode = vt_do_kdgkbmode(fg_console); 206 if (mode == K_UNICODE) 207 use_unicode = 1; 208 else 209 use_unicode = 0; 210 211 switch (v.sel_mode) 212 { 213 case TIOCL_SELCHAR: /* character-by-character selection */ 214 new_sel_start = ps; 215 new_sel_end = pe; 216 break; 217 case TIOCL_SELWORD: /* word-by-word selection */ 218 spc = isspace(sel_pos(ps)); 219 for (new_sel_start = ps; ; ps -= 2) 220 { 221 if ((spc && !isspace(sel_pos(ps))) || 222 (!spc && !inword(sel_pos(ps)))) 223 break; 224 new_sel_start = ps; 225 if (!(ps % vc->vc_size_row)) 226 break; 227 } 228 spc = isspace(sel_pos(pe)); 229 for (new_sel_end = pe; ; pe += 2) 230 { 231 if ((spc && !isspace(sel_pos(pe))) || 232 (!spc && !inword(sel_pos(pe)))) 233 break; 234 new_sel_end = pe; 235 if (!((pe + 2) % vc->vc_size_row)) 236 break; 237 } 238 break; 239 case TIOCL_SELLINE: /* line-by-line selection */ 240 new_sel_start = ps - ps % vc->vc_size_row; 241 new_sel_end = pe + vc->vc_size_row 242 - pe % vc->vc_size_row - 2; 243 break; 244 case TIOCL_SELPOINTER: 245 highlight_pointer(pe); 246 return 0; 247 default: 248 return -EINVAL; 249 } 250 251 /* remove the pointer */ 252 highlight_pointer(-1); 253 254 /* select to end of line if on trailing space */ 255 if (new_sel_end > new_sel_start && 256 !atedge(new_sel_end, vc->vc_size_row) && 257 isspace(sel_pos(new_sel_end))) { 258 for (pe = new_sel_end + 2; ; pe += 2) 259 if (!isspace(sel_pos(pe)) || 260 atedge(pe, vc->vc_size_row)) 261 break; 262 if (isspace(sel_pos(pe))) 263 new_sel_end = pe; 264 } 265 if (sel_start == -1) /* no current selection */ 266 highlight(new_sel_start, new_sel_end); 267 else if (new_sel_start == sel_start) 268 { 269 if (new_sel_end == sel_end) /* no action required */ 270 return 0; 271 else if (new_sel_end > sel_end) /* extend to right */ 272 highlight(sel_end + 2, new_sel_end); 273 else /* contract from right */ 274 highlight(new_sel_end + 2, sel_end); 275 } 276 else if (new_sel_end == sel_end) 277 { 278 if (new_sel_start < sel_start) /* extend to left */ 279 highlight(new_sel_start, sel_start - 2); 280 else /* contract from left */ 281 highlight(sel_start, new_sel_start - 2); 282 } 283 else /* some other case; start selection from scratch */ 284 { 285 clear_selection(); 286 highlight(new_sel_start, new_sel_end); 287 } 288 sel_start = new_sel_start; 289 sel_end = new_sel_end; 290 291 /* Allocate a new buffer before freeing the old one ... */ 292 multiplier = use_unicode ? 4 : 1; /* chars can take up to 4 bytes */ 293 bp = kmalloc_array((sel_end - sel_start) / 2 + 1, multiplier, 294 GFP_KERNEL); 295 if (!bp) { 296 printk(KERN_WARNING "selection: kmalloc() failed\n"); 297 clear_selection(); 298 return -ENOMEM; 299 } 300 kfree(sel_buffer); 301 sel_buffer = bp; 302 303 obp = bp; 304 for (i = sel_start; i <= sel_end; i += 2) { 305 c = sel_pos(i); 306 if (use_unicode) 307 bp += store_utf8(c, bp); 308 else 309 *bp++ = c; 310 if (!isspace(c)) 311 obp = bp; 312 if (! ((i + 2) % vc->vc_size_row)) { 313 /* strip trailing blanks from line and add newline, 314 unless non-space at end of line. */ 315 if (obp != bp) { 316 bp = obp; 317 *bp++ = '\r'; 318 } 319 obp = bp; 320 } 321 } 322 sel_buffer_lth = bp - sel_buffer; 323 return 0; 324 } 325 326 /* Insert the contents of the selection buffer into the 327 * queue of the tty associated with the current console. 328 * Invoked by ioctl(). 329 * 330 * Locking: called without locks. Calls the ldisc wrongly with 331 * unsafe methods, 332 */ 333 int paste_selection(struct tty_struct *tty) 334 { 335 struct vc_data *vc = tty->driver_data; 336 int pasted = 0; 337 unsigned int count; 338 struct tty_ldisc *ld; 339 DECLARE_WAITQUEUE(wait, current); 340 341 console_lock(); 342 poke_blanked_console(); 343 console_unlock(); 344 345 ld = tty_ldisc_ref_wait(tty); 346 if (!ld) 347 return -EIO; /* ldisc was hung up */ 348 tty_buffer_lock_exclusive(&vc->port); 349 350 add_wait_queue(&vc->paste_wait, &wait); 351 while (sel_buffer && sel_buffer_lth > pasted) { 352 set_current_state(TASK_INTERRUPTIBLE); 353 if (tty_throttled(tty)) { 354 schedule(); 355 continue; 356 } 357 __set_current_state(TASK_RUNNING); 358 count = sel_buffer_lth - pasted; 359 count = tty_ldisc_receive_buf(ld, sel_buffer + pasted, NULL, 360 count); 361 pasted += count; 362 } 363 remove_wait_queue(&vc->paste_wait, &wait); 364 __set_current_state(TASK_RUNNING); 365 366 tty_buffer_unlock_exclusive(&vc->port); 367 tty_ldisc_deref(ld); 368 return 0; 369 } 370