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 new_sel_start, new_sel_end, spc; 160 struct tiocl_selection v; 161 char *bp, *obp; 162 int i, ps, pe, multiplier; 163 u16 c; 164 int mode; 165 166 poke_blanked_console(); 167 if (copy_from_user(&v, sel, sizeof(*sel))) 168 return -EFAULT; 169 170 v.xs = limit(v.xs - 1, vc->vc_cols - 1); 171 v.ys = limit(v.ys - 1, vc->vc_rows - 1); 172 v.xe = limit(v.xe - 1, vc->vc_cols - 1); 173 v.ye = limit(v.ye - 1, vc->vc_rows - 1); 174 ps = v.ys * vc->vc_size_row + (v.xs << 1); 175 pe = v.ye * vc->vc_size_row + (v.xe << 1); 176 177 if (v.sel_mode == TIOCL_SELCLEAR) { 178 /* useful for screendump without selection highlights */ 179 clear_selection(); 180 return 0; 181 } 182 183 if (mouse_reporting() && (v.sel_mode & TIOCL_SELMOUSEREPORT)) { 184 mouse_report(tty, v.sel_mode & TIOCL_SELBUTTONMASK, v.xs, v.ys); 185 return 0; 186 } 187 188 if (ps > pe) /* make sel_start <= sel_end */ 189 swap(ps, pe); 190 191 if (sel_cons != vc_cons[fg_console].d) { 192 clear_selection(); 193 sel_cons = vc_cons[fg_console].d; 194 } 195 mode = vt_do_kdgkbmode(fg_console); 196 if (mode == K_UNICODE) 197 use_unicode = 1; 198 else 199 use_unicode = 0; 200 201 switch (v.sel_mode) 202 { 203 case TIOCL_SELCHAR: /* character-by-character selection */ 204 new_sel_start = ps; 205 new_sel_end = pe; 206 break; 207 case TIOCL_SELWORD: /* word-by-word selection */ 208 spc = isspace(sel_pos(ps)); 209 for (new_sel_start = ps; ; ps -= 2) 210 { 211 if ((spc && !isspace(sel_pos(ps))) || 212 (!spc && !inword(sel_pos(ps)))) 213 break; 214 new_sel_start = ps; 215 if (!(ps % vc->vc_size_row)) 216 break; 217 } 218 spc = isspace(sel_pos(pe)); 219 for (new_sel_end = pe; ; pe += 2) 220 { 221 if ((spc && !isspace(sel_pos(pe))) || 222 (!spc && !inword(sel_pos(pe)))) 223 break; 224 new_sel_end = pe; 225 if (!((pe + 2) % vc->vc_size_row)) 226 break; 227 } 228 break; 229 case TIOCL_SELLINE: /* line-by-line selection */ 230 new_sel_start = ps - ps % vc->vc_size_row; 231 new_sel_end = pe + vc->vc_size_row 232 - pe % vc->vc_size_row - 2; 233 break; 234 case TIOCL_SELPOINTER: 235 highlight_pointer(pe); 236 return 0; 237 default: 238 return -EINVAL; 239 } 240 241 /* remove the pointer */ 242 highlight_pointer(-1); 243 244 /* select to end of line if on trailing space */ 245 if (new_sel_end > new_sel_start && 246 !atedge(new_sel_end, vc->vc_size_row) && 247 isspace(sel_pos(new_sel_end))) { 248 for (pe = new_sel_end + 2; ; pe += 2) 249 if (!isspace(sel_pos(pe)) || 250 atedge(pe, vc->vc_size_row)) 251 break; 252 if (isspace(sel_pos(pe))) 253 new_sel_end = pe; 254 } 255 if (sel_start == -1) /* no current selection */ 256 highlight(new_sel_start, new_sel_end); 257 else if (new_sel_start == sel_start) 258 { 259 if (new_sel_end == sel_end) /* no action required */ 260 return 0; 261 else if (new_sel_end > sel_end) /* extend to right */ 262 highlight(sel_end + 2, new_sel_end); 263 else /* contract from right */ 264 highlight(new_sel_end + 2, sel_end); 265 } 266 else if (new_sel_end == sel_end) 267 { 268 if (new_sel_start < sel_start) /* extend to left */ 269 highlight(new_sel_start, sel_start - 2); 270 else /* contract from left */ 271 highlight(sel_start, new_sel_start - 2); 272 } 273 else /* some other case; start selection from scratch */ 274 { 275 clear_selection(); 276 highlight(new_sel_start, new_sel_end); 277 } 278 sel_start = new_sel_start; 279 sel_end = new_sel_end; 280 281 /* Allocate a new buffer before freeing the old one ... */ 282 multiplier = use_unicode ? 3 : 1; /* chars can take up to 3 bytes */ 283 bp = kmalloc(((sel_end-sel_start)/2+1)*multiplier, GFP_KERNEL); 284 if (!bp) { 285 printk(KERN_WARNING "selection: kmalloc() failed\n"); 286 clear_selection(); 287 return -ENOMEM; 288 } 289 kfree(sel_buffer); 290 sel_buffer = bp; 291 292 obp = bp; 293 for (i = sel_start; i <= sel_end; i += 2) { 294 c = sel_pos(i); 295 if (use_unicode) 296 bp += store_utf8(c, bp); 297 else 298 *bp++ = c; 299 if (!isspace(c)) 300 obp = bp; 301 if (! ((i + 2) % vc->vc_size_row)) { 302 /* strip trailing blanks from line and add newline, 303 unless non-space at end of line. */ 304 if (obp != bp) { 305 bp = obp; 306 *bp++ = '\r'; 307 } 308 obp = bp; 309 } 310 } 311 sel_buffer_lth = bp - sel_buffer; 312 return 0; 313 } 314 315 /* Insert the contents of the selection buffer into the 316 * queue of the tty associated with the current console. 317 * Invoked by ioctl(). 318 * 319 * Locking: called without locks. Calls the ldisc wrongly with 320 * unsafe methods, 321 */ 322 int paste_selection(struct tty_struct *tty) 323 { 324 struct vc_data *vc = tty->driver_data; 325 int pasted = 0; 326 unsigned int count; 327 struct tty_ldisc *ld; 328 DECLARE_WAITQUEUE(wait, current); 329 330 console_lock(); 331 poke_blanked_console(); 332 console_unlock(); 333 334 ld = tty_ldisc_ref_wait(tty); 335 if (!ld) 336 return -EIO; /* ldisc was hung up */ 337 tty_buffer_lock_exclusive(&vc->port); 338 339 add_wait_queue(&vc->paste_wait, &wait); 340 while (sel_buffer && sel_buffer_lth > pasted) { 341 set_current_state(TASK_INTERRUPTIBLE); 342 if (tty_throttled(tty)) { 343 schedule(); 344 continue; 345 } 346 __set_current_state(TASK_RUNNING); 347 count = sel_buffer_lth - pasted; 348 count = tty_ldisc_receive_buf(ld, sel_buffer + pasted, NULL, 349 count); 350 pasted += count; 351 } 352 remove_wait_queue(&vc->paste_wait, &wait); 353 __set_current_state(TASK_RUNNING); 354 355 tty_buffer_unlock_exclusive(&vc->port); 356 tty_ldisc_deref(ld); 357 return 0; 358 } 359