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 u16 61 sel_pos(int n) 62 { 63 return inverse_translate(sel_cons, screen_glyph(sel_cons, n), 64 use_unicode); 65 } 66 67 /** 68 * clear_selection - remove current selection 69 * 70 * Remove the current selection highlight, if any from the console 71 * holding the selection. The caller must hold the console lock. 72 */ 73 void clear_selection(void) 74 { 75 highlight_pointer(-1); /* hide the pointer */ 76 if (sel_start != -1) { 77 highlight(sel_start, sel_end); 78 sel_start = -1; 79 } 80 } 81 82 /* 83 * User settable table: what characters are to be considered alphabetic? 84 * 128 bits. Locked by the console lock. 85 */ 86 static u32 inwordLut[]={ 87 0x00000000, /* control chars */ 88 0x03FFE000, /* digits and "-./" */ 89 0x87FFFFFE, /* uppercase and '_' */ 90 0x07FFFFFE, /* lowercase */ 91 }; 92 93 static inline int inword(const u16 c) { 94 return c > 0x7f || (( inwordLut[c>>5] >> (c & 0x1F) ) & 1); 95 } 96 97 /** 98 * set loadlut - load the LUT table 99 * @p: user table 100 * 101 * Load the LUT table from user space. The caller must hold the console 102 * lock. Make a temporary copy so a partial update doesn't make a mess. 103 */ 104 int sel_loadlut(char __user *p) 105 { 106 u32 tmplut[ARRAY_SIZE(inwordLut)]; 107 if (copy_from_user(tmplut, (u32 __user *)(p+4), sizeof(inwordLut))) 108 return -EFAULT; 109 memcpy(inwordLut, tmplut, sizeof(inwordLut)); 110 return 0; 111 } 112 113 /* does screen address p correspond to character at LH/RH edge of screen? */ 114 static inline int atedge(const int p, int size_row) 115 { 116 return (!(p % size_row) || !((p + 2) % size_row)); 117 } 118 119 /* constrain v such that v <= u */ 120 static inline unsigned short limit(const unsigned short v, const unsigned short u) 121 { 122 return (v > u) ? u : v; 123 } 124 125 /* stores the char in UTF8 and returns the number of bytes used (1-3) */ 126 static int store_utf8(u16 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 { 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 } 144 } 145 146 /** 147 * set_selection - set the current selection. 148 * @sel: user selection info 149 * @tty: the console tty 150 * 151 * Invoked by the ioctl handle for the vt layer. 152 * 153 * The entire selection process is managed under the console_lock. It's 154 * a lot under the lock but its hardly a performance path 155 */ 156 int set_selection(const struct tiocl_selection __user *sel, struct tty_struct *tty) 157 { 158 struct vc_data *vc = vc_cons[fg_console].d; 159 int sel_mode, new_sel_start, new_sel_end, spc; 160 char *bp, *obp; 161 int i, ps, pe, multiplier; 162 u16 c; 163 int mode; 164 165 poke_blanked_console(); 166 167 { unsigned short xs, ys, xe, ye; 168 169 if (!access_ok(VERIFY_READ, sel, sizeof(*sel))) 170 return -EFAULT; 171 __get_user(xs, &sel->xs); 172 __get_user(ys, &sel->ys); 173 __get_user(xe, &sel->xe); 174 __get_user(ye, &sel->ye); 175 __get_user(sel_mode, &sel->sel_mode); 176 xs--; ys--; xe--; ye--; 177 xs = limit(xs, vc->vc_cols - 1); 178 ys = limit(ys, vc->vc_rows - 1); 179 xe = limit(xe, vc->vc_cols - 1); 180 ye = limit(ye, vc->vc_rows - 1); 181 ps = ys * vc->vc_size_row + (xs << 1); 182 pe = ye * vc->vc_size_row + (xe << 1); 183 184 if (sel_mode == TIOCL_SELCLEAR) { 185 /* useful for screendump without selection highlights */ 186 clear_selection(); 187 return 0; 188 } 189 190 if (mouse_reporting() && (sel_mode & TIOCL_SELMOUSEREPORT)) { 191 mouse_report(tty, sel_mode & TIOCL_SELBUTTONMASK, xs, ys); 192 return 0; 193 } 194 } 195 196 if (ps > pe) /* make sel_start <= sel_end */ 197 { 198 int tmp = ps; 199 ps = pe; 200 pe = tmp; 201 } 202 203 if (sel_cons != vc_cons[fg_console].d) { 204 clear_selection(); 205 sel_cons = vc_cons[fg_console].d; 206 } 207 mode = vt_do_kdgkbmode(fg_console); 208 if (mode == K_UNICODE) 209 use_unicode = 1; 210 else 211 use_unicode = 0; 212 213 switch (sel_mode) 214 { 215 case TIOCL_SELCHAR: /* character-by-character selection */ 216 new_sel_start = ps; 217 new_sel_end = pe; 218 break; 219 case TIOCL_SELWORD: /* word-by-word selection */ 220 spc = isspace(sel_pos(ps)); 221 for (new_sel_start = ps; ; ps -= 2) 222 { 223 if ((spc && !isspace(sel_pos(ps))) || 224 (!spc && !inword(sel_pos(ps)))) 225 break; 226 new_sel_start = ps; 227 if (!(ps % vc->vc_size_row)) 228 break; 229 } 230 spc = isspace(sel_pos(pe)); 231 for (new_sel_end = pe; ; pe += 2) 232 { 233 if ((spc && !isspace(sel_pos(pe))) || 234 (!spc && !inword(sel_pos(pe)))) 235 break; 236 new_sel_end = pe; 237 if (!((pe + 2) % vc->vc_size_row)) 238 break; 239 } 240 break; 241 case TIOCL_SELLINE: /* line-by-line selection */ 242 new_sel_start = ps - ps % vc->vc_size_row; 243 new_sel_end = pe + vc->vc_size_row 244 - pe % vc->vc_size_row - 2; 245 break; 246 case TIOCL_SELPOINTER: 247 highlight_pointer(pe); 248 return 0; 249 default: 250 return -EINVAL; 251 } 252 253 /* remove the pointer */ 254 highlight_pointer(-1); 255 256 /* select to end of line if on trailing space */ 257 if (new_sel_end > new_sel_start && 258 !atedge(new_sel_end, vc->vc_size_row) && 259 isspace(sel_pos(new_sel_end))) { 260 for (pe = new_sel_end + 2; ; pe += 2) 261 if (!isspace(sel_pos(pe)) || 262 atedge(pe, vc->vc_size_row)) 263 break; 264 if (isspace(sel_pos(pe))) 265 new_sel_end = pe; 266 } 267 if (sel_start == -1) /* no current selection */ 268 highlight(new_sel_start, new_sel_end); 269 else if (new_sel_start == sel_start) 270 { 271 if (new_sel_end == sel_end) /* no action required */ 272 return 0; 273 else if (new_sel_end > sel_end) /* extend to right */ 274 highlight(sel_end + 2, new_sel_end); 275 else /* contract from right */ 276 highlight(new_sel_end + 2, sel_end); 277 } 278 else if (new_sel_end == sel_end) 279 { 280 if (new_sel_start < sel_start) /* extend to left */ 281 highlight(new_sel_start, sel_start - 2); 282 else /* contract from left */ 283 highlight(sel_start, new_sel_start - 2); 284 } 285 else /* some other case; start selection from scratch */ 286 { 287 clear_selection(); 288 highlight(new_sel_start, new_sel_end); 289 } 290 sel_start = new_sel_start; 291 sel_end = new_sel_end; 292 293 /* Allocate a new buffer before freeing the old one ... */ 294 multiplier = use_unicode ? 3 : 1; /* chars can take up to 3 bytes */ 295 bp = kmalloc(((sel_end-sel_start)/2+1)*multiplier, GFP_KERNEL); 296 if (!bp) { 297 printk(KERN_WARNING "selection: kmalloc() failed\n"); 298 clear_selection(); 299 return -ENOMEM; 300 } 301 kfree(sel_buffer); 302 sel_buffer = bp; 303 304 obp = bp; 305 for (i = sel_start; i <= sel_end; i += 2) { 306 c = sel_pos(i); 307 if (use_unicode) 308 bp += store_utf8(c, bp); 309 else 310 *bp++ = c; 311 if (!isspace(c)) 312 obp = bp; 313 if (! ((i + 2) % vc->vc_size_row)) { 314 /* strip trailing blanks from line and add newline, 315 unless non-space at end of line. */ 316 if (obp != bp) { 317 bp = obp; 318 *bp++ = '\r'; 319 } 320 obp = bp; 321 } 322 } 323 sel_buffer_lth = bp - sel_buffer; 324 return 0; 325 } 326 327 /* Insert the contents of the selection buffer into the 328 * queue of the tty associated with the current console. 329 * Invoked by ioctl(). 330 * 331 * Locking: called without locks. Calls the ldisc wrongly with 332 * unsafe methods, 333 */ 334 int paste_selection(struct tty_struct *tty) 335 { 336 struct vc_data *vc = tty->driver_data; 337 int pasted = 0; 338 unsigned int count; 339 struct tty_ldisc *ld; 340 DECLARE_WAITQUEUE(wait, current); 341 342 console_lock(); 343 poke_blanked_console(); 344 console_unlock(); 345 346 ld = tty_ldisc_ref_wait(tty); 347 if (!ld) 348 return -EIO; /* ldisc was hung up */ 349 tty_buffer_lock_exclusive(&vc->port); 350 351 add_wait_queue(&vc->paste_wait, &wait); 352 while (sel_buffer && sel_buffer_lth > pasted) { 353 set_current_state(TASK_INTERRUPTIBLE); 354 if (tty_throttled(tty)) { 355 schedule(); 356 continue; 357 } 358 __set_current_state(TASK_RUNNING); 359 count = sel_buffer_lth - pasted; 360 count = tty_ldisc_receive_buf(ld, sel_buffer + pasted, NULL, 361 count); 362 pasted += count; 363 } 364 remove_wait_queue(&vc->paste_wait, &wait); 365 __set_current_state(TASK_RUNNING); 366 367 tty_buffer_unlock_exclusive(&vc->port); 368 tty_ldisc_deref(ld); 369 return 0; 370 } 371