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 /* stores the char in UTF8 and returns the number of bytes used (1-3) */ 120 static int store_utf8(u16 c, char *p) 121 { 122 if (c < 0x80) { 123 /* 0******* */ 124 p[0] = c; 125 return 1; 126 } else if (c < 0x800) { 127 /* 110***** 10****** */ 128 p[0] = 0xc0 | (c >> 6); 129 p[1] = 0x80 | (c & 0x3f); 130 return 2; 131 } else { 132 /* 1110**** 10****** 10****** */ 133 p[0] = 0xe0 | (c >> 12); 134 p[1] = 0x80 | ((c >> 6) & 0x3f); 135 p[2] = 0x80 | (c & 0x3f); 136 return 3; 137 } 138 } 139 140 /** 141 * set_selection - set the current selection. 142 * @sel: user selection info 143 * @tty: the console tty 144 * 145 * Invoked by the ioctl handle for the vt layer. 146 * 147 * The entire selection process is managed under the console_lock. It's 148 * a lot under the lock but its hardly a performance path 149 */ 150 int set_selection(const struct tiocl_selection __user *sel, struct tty_struct *tty) 151 { 152 struct vc_data *vc = vc_cons[fg_console].d; 153 int new_sel_start, new_sel_end, spc; 154 struct tiocl_selection v; 155 char *bp, *obp; 156 int i, ps, pe, multiplier; 157 u16 c; 158 int mode; 159 160 poke_blanked_console(); 161 if (copy_from_user(&v, sel, sizeof(*sel))) 162 return -EFAULT; 163 164 v.xs = min_t(u16, v.xs - 1, vc->vc_cols - 1); 165 v.ys = min_t(u16, v.ys - 1, vc->vc_rows - 1); 166 v.xe = min_t(u16, v.xe - 1, vc->vc_cols - 1); 167 v.ye = min_t(u16, v.ye - 1, vc->vc_rows - 1); 168 ps = v.ys * vc->vc_size_row + (v.xs << 1); 169 pe = v.ye * vc->vc_size_row + (v.xe << 1); 170 171 if (v.sel_mode == TIOCL_SELCLEAR) { 172 /* useful for screendump without selection highlights */ 173 clear_selection(); 174 return 0; 175 } 176 177 if (mouse_reporting() && (v.sel_mode & TIOCL_SELMOUSEREPORT)) { 178 mouse_report(tty, v.sel_mode & TIOCL_SELBUTTONMASK, v.xs, v.ys); 179 return 0; 180 } 181 182 if (ps > pe) /* make sel_start <= sel_end */ 183 swap(ps, pe); 184 185 if (sel_cons != vc_cons[fg_console].d) { 186 clear_selection(); 187 sel_cons = vc_cons[fg_console].d; 188 } 189 mode = vt_do_kdgkbmode(fg_console); 190 if (mode == K_UNICODE) 191 use_unicode = 1; 192 else 193 use_unicode = 0; 194 195 switch (v.sel_mode) 196 { 197 case TIOCL_SELCHAR: /* character-by-character selection */ 198 new_sel_start = ps; 199 new_sel_end = pe; 200 break; 201 case TIOCL_SELWORD: /* word-by-word selection */ 202 spc = isspace(sel_pos(ps)); 203 for (new_sel_start = ps; ; ps -= 2) 204 { 205 if ((spc && !isspace(sel_pos(ps))) || 206 (!spc && !inword(sel_pos(ps)))) 207 break; 208 new_sel_start = ps; 209 if (!(ps % vc->vc_size_row)) 210 break; 211 } 212 spc = isspace(sel_pos(pe)); 213 for (new_sel_end = pe; ; pe += 2) 214 { 215 if ((spc && !isspace(sel_pos(pe))) || 216 (!spc && !inword(sel_pos(pe)))) 217 break; 218 new_sel_end = pe; 219 if (!((pe + 2) % vc->vc_size_row)) 220 break; 221 } 222 break; 223 case TIOCL_SELLINE: /* line-by-line selection */ 224 new_sel_start = ps - ps % vc->vc_size_row; 225 new_sel_end = pe + vc->vc_size_row 226 - pe % vc->vc_size_row - 2; 227 break; 228 case TIOCL_SELPOINTER: 229 highlight_pointer(pe); 230 return 0; 231 default: 232 return -EINVAL; 233 } 234 235 /* remove the pointer */ 236 highlight_pointer(-1); 237 238 /* select to end of line if on trailing space */ 239 if (new_sel_end > new_sel_start && 240 !atedge(new_sel_end, vc->vc_size_row) && 241 isspace(sel_pos(new_sel_end))) { 242 for (pe = new_sel_end + 2; ; pe += 2) 243 if (!isspace(sel_pos(pe)) || 244 atedge(pe, vc->vc_size_row)) 245 break; 246 if (isspace(sel_pos(pe))) 247 new_sel_end = pe; 248 } 249 if (sel_start == -1) /* no current selection */ 250 highlight(new_sel_start, new_sel_end); 251 else if (new_sel_start == sel_start) 252 { 253 if (new_sel_end == sel_end) /* no action required */ 254 return 0; 255 else if (new_sel_end > sel_end) /* extend to right */ 256 highlight(sel_end + 2, new_sel_end); 257 else /* contract from right */ 258 highlight(new_sel_end + 2, sel_end); 259 } 260 else if (new_sel_end == sel_end) 261 { 262 if (new_sel_start < sel_start) /* extend to left */ 263 highlight(new_sel_start, sel_start - 2); 264 else /* contract from left */ 265 highlight(sel_start, new_sel_start - 2); 266 } 267 else /* some other case; start selection from scratch */ 268 { 269 clear_selection(); 270 highlight(new_sel_start, new_sel_end); 271 } 272 sel_start = new_sel_start; 273 sel_end = new_sel_end; 274 275 /* Allocate a new buffer before freeing the old one ... */ 276 multiplier = use_unicode ? 3 : 1; /* chars can take up to 3 bytes */ 277 bp = kmalloc_array((sel_end - sel_start) / 2 + 1, multiplier, 278 GFP_KERNEL); 279 if (!bp) { 280 printk(KERN_WARNING "selection: kmalloc() failed\n"); 281 clear_selection(); 282 return -ENOMEM; 283 } 284 kfree(sel_buffer); 285 sel_buffer = bp; 286 287 obp = bp; 288 for (i = sel_start; i <= sel_end; i += 2) { 289 c = sel_pos(i); 290 if (use_unicode) 291 bp += store_utf8(c, bp); 292 else 293 *bp++ = c; 294 if (!isspace(c)) 295 obp = bp; 296 if (! ((i + 2) % vc->vc_size_row)) { 297 /* strip trailing blanks from line and add newline, 298 unless non-space at end of line. */ 299 if (obp != bp) { 300 bp = obp; 301 *bp++ = '\r'; 302 } 303 obp = bp; 304 } 305 } 306 sel_buffer_lth = bp - sel_buffer; 307 return 0; 308 } 309 310 /* Insert the contents of the selection buffer into the 311 * queue of the tty associated with the current console. 312 * Invoked by ioctl(). 313 * 314 * Locking: called without locks. Calls the ldisc wrongly with 315 * unsafe methods, 316 */ 317 int paste_selection(struct tty_struct *tty) 318 { 319 struct vc_data *vc = tty->driver_data; 320 int pasted = 0; 321 unsigned int count; 322 struct tty_ldisc *ld; 323 DECLARE_WAITQUEUE(wait, current); 324 325 console_lock(); 326 poke_blanked_console(); 327 console_unlock(); 328 329 ld = tty_ldisc_ref_wait(tty); 330 if (!ld) 331 return -EIO; /* ldisc was hung up */ 332 tty_buffer_lock_exclusive(&vc->port); 333 334 add_wait_queue(&vc->paste_wait, &wait); 335 while (sel_buffer && sel_buffer_lth > pasted) { 336 set_current_state(TASK_INTERRUPTIBLE); 337 if (tty_throttled(tty)) { 338 schedule(); 339 continue; 340 } 341 __set_current_state(TASK_RUNNING); 342 count = sel_buffer_lth - pasted; 343 count = tty_ldisc_receive_buf(ld, sel_buffer + pasted, NULL, 344 count); 345 pasted += count; 346 } 347 remove_wait_queue(&vc->paste_wait, &wait); 348 __set_current_state(TASK_RUNNING); 349 350 tty_buffer_unlock_exclusive(&vc->port); 351 tty_ldisc_deref(ld); 352 return 0; 353 } 354