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// SPDX-License-Identifier: GPL-2.0/* * This module exports the functions: * *     'int set_selection_user(struct tiocl_selection __user *, *			       struct tty_struct *)' *     'int set_selection_kernel(struct tiocl_selection *, struct tty_struct *)' *     'void clear_selection(void)' *     'int paste_selection(struct tty_struct *)' *     'int sel_loadlut(u32 __user *)' * * Now that /dev/vcs exists, most of this can disappear again. */ #include <linux/module.h>#include <linux/tty.h>#include <linux/sched.h>#include <linux/mm.h>#include <linux/mutex.h>#include <linux/slab.h>#include <linux/types.h> #include <linux/uaccess.h> #include <linux/kbd_kern.h>#include <linux/vt_kern.h>#include <linux/consolemap.h>#include <linux/selection.h>#include <linux/tiocl.h>#include <linux/console.h>#include <linux/tty_flip.h> #include <linux/sched/signal.h> /* Don't take this from <ctype.h>: 011-015 on the screen aren't spaces */#define is_space_on_vt(c)	((c) == ' ') /* FIXME: all this needs locking */static struct vc_selection {	struct mutex lock;	struct vc_data *cons;			/* must not be deallocated */	char *buffer;	unsigned int buf_len;	volatile int start;			/* cleared by clear_selection */	int end;} vc_sel = {	.lock = __MUTEX_INITIALIZER(vc_sel.lock),	.start = -1,}; /* clear_selection, highlight and highlight_pointer can be called   from interrupt (via scrollback/front) */ /* set reverse video on characters s-e of console with selection. */static inline void highlight(const int s, const int e){	invert_screen(vc_sel.cons, s, e-s+2, true);} /* use complementary color to show the pointer */static inline void highlight_pointer(const int where){	complement_pos(vc_sel.cons, where);} static u32sel_pos(int n, bool unicode){	if (unicode)		return screen_glyph_unicode(vc_sel.cons, n / 2);	return inverse_translate(vc_sel.cons, screen_glyph(vc_sel.cons, n),			false);} /** * clear_selection - remove current selection * * Remove the current selection highlight, if any from the console holding the * selection. * * Locking: The caller must hold the console lock. */void clear_selection(void){	highlight_pointer(-1); /* hide the pointer */	if (vc_sel.start != -1) {		highlight(vc_sel.start, vc_sel.end);		vc_sel.start = -1;	}}EXPORT_SYMBOL_GPL(clear_selection); bool vc_is_sel(const struct vc_data *vc){	return vc == vc_sel.cons;} /* * User settable table: what characters are to be considered alphabetic? * 128 bits. Locked by the console lock. */static u32 inwordLut[]={  0x00000000, /* control chars     */  0x03FFE000, /* digits and "-./"  */  0x87FFFFFE, /* uppercase and '_' */  0x07FFFFFE, /* lowercase         */}; static inline int inword(const u32 c){	return c > 0x7f || (( inwordLut[c>>5] >> (c & 0x1F) ) & 1);} /** * sel_loadlut() - load the LUT table * @lut: user table * * Load the LUT table from user space. Make a temporary copy so a partial * update doesn't make a mess. * * Locking: The console lock is acquired. */int sel_loadlut(u32 __user *lut){	u32 tmplut[ARRAY_SIZE(inwordLut)]; 	if (copy_from_user(tmplut, lut, sizeof(inwordLut)))		return -EFAULT; 	guard(console_lock)();	memcpy(inwordLut, tmplut, sizeof(inwordLut)); 	return 0;} /* does screen address p correspond to character at LH/RH edge of screen? */static inline int atedge(const int p, int size_row){	return (!(p % size_row)	|| !((p + 2) % size_row));} /* stores the char in UTF8 and returns the number of bytes used (1-4) */static int store_utf8(u32 c, char *p){	if (c < 0x80) {		/*  0******* */		p[0] = c;		return 1;	} else if (c < 0x800) {		/* 110***** 10****** */		p[0] = 0xc0 | (c >> 6);		p[1] = 0x80 | (c & 0x3f);		return 2;	} else if (c < 0x10000) {		/* 1110**** 10****** 10****** */		p[0] = 0xe0 | (c >> 12);		p[1] = 0x80 | ((c >> 6) & 0x3f);		p[2] = 0x80 | (c & 0x3f);		return 3;	} else if (c < 0x110000) {		/* 11110*** 10****** 10****** 10****** */		p[0] = 0xf0 | (c >> 18);		p[1] = 0x80 | ((c >> 12) & 0x3f);		p[2] = 0x80 | ((c >> 6) & 0x3f);		p[3] = 0x80 | (c & 0x3f);		return 4;	} else {		/* outside Unicode, replace with U+FFFD */		p[0] = 0xef;		p[1] = 0xbf;		p[2] = 0xbd;		return 3;	}} /** * set_selection_user - set the current selection. * @sel: user selection info * @tty: the console tty * * Invoked by the ioctl handle for the vt layer. * * Locking: The entire selection process is managed under the console_lock. * It's a lot under the lock but its hardly a performance path. */int set_selection_user(const struct tiocl_selection __user *sel,		       struct tty_struct *tty){	struct tiocl_selection v; 	if (copy_from_user(&v, sel, sizeof(*sel)))		return -EFAULT; 	/*	 * TIOCL_SELCLEAR and TIOCL_SELPOINTER are OK to use without	 * CAP_SYS_ADMIN as they do not modify the selection.	 */	switch (v.sel_mode) {	case TIOCL_SELCLEAR:	case TIOCL_SELPOINTER:		break;	default:		if (!capable(CAP_SYS_ADMIN))			return -EPERM;	} 	return set_selection_kernel(&v, tty);} static int vc_selection_store_chars(struct vc_data *vc, bool unicode){	char *bp, *obp;	unsigned int i; 	/* Allocate a new buffer before freeing the old one ... */	/* chars can take up to 4 bytes with unicode */	bp = kmalloc_array((vc_sel.end - vc_sel.start) / 2 + 1, unicode ? 4 : 1,			   GFP_KERNEL | __GFP_NOWARN);	if (!bp) {		printk(KERN_WARNING "selection: kmalloc() failed\n");		clear_selection();		return -ENOMEM;	}	kfree(vc_sel.buffer);	vc_sel.buffer = bp; 	obp = bp;	for (i = vc_sel.start; i <= vc_sel.end; i += 2) {		u32 c = sel_pos(i, unicode);		if (unicode)			bp += store_utf8(c, bp);		else			*bp++ = c;		if (!is_space_on_vt(c))			obp = bp;		if (!((i + 2) % vc->vc_size_row)) {			/* strip trailing blanks from line and add newline,			   unless non-space at end of line. */			if (obp != bp) {				bp = obp;				*bp++ = '\r';			}			obp = bp;		}	}	vc_sel.buf_len = bp - vc_sel.buffer; 	return 0;} static int vc_do_selection(struct vc_data *vc, unsigned short mode, int ps,		int pe){	int new_sel_start, new_sel_end, spc;	bool unicode = vt_do_kdgkbmode(fg_console) == K_UNICODE; 	switch (mode) {	case TIOCL_SELCHAR:	/* character-by-character selection */		new_sel_start = ps;		new_sel_end = pe;		break;	case TIOCL_SELWORD:	/* word-by-word selection */		spc = is_space_on_vt(sel_pos(ps, unicode));		for (new_sel_start = ps; ; ps -= 2) {			if ((spc && !is_space_on_vt(sel_pos(ps, unicode))) ||			    (!spc && !inword(sel_pos(ps, unicode))))				break;			new_sel_start = ps;			if (!(ps % vc->vc_size_row))				break;		} 		spc = is_space_on_vt(sel_pos(pe, unicode));		for (new_sel_end = pe; ; pe += 2) {			if ((spc && !is_space_on_vt(sel_pos(pe, unicode))) ||			    (!spc && !inword(sel_pos(pe, unicode))))				break;			new_sel_end = pe;			if (!((pe + 2) % vc->vc_size_row))				break;		}		break;	case TIOCL_SELLINE:	/* line-by-line selection */		new_sel_start = rounddown(ps, vc->vc_size_row);		new_sel_end = rounddown(pe, vc->vc_size_row) +			vc->vc_size_row - 2;		break;	case TIOCL_SELPOINTER:		highlight_pointer(pe);		return 0;	default:		return -EINVAL;	} 	/* remove the pointer */	highlight_pointer(-1); 	/* select to end of line if on trailing space */	if (new_sel_end > new_sel_start &&		!atedge(new_sel_end, vc->vc_size_row) &&		is_space_on_vt(sel_pos(new_sel_end, unicode))) {		for (pe = new_sel_end + 2; ; pe += 2)			if (!is_space_on_vt(sel_pos(pe, unicode)) ||			    atedge(pe, vc->vc_size_row))				break;		if (is_space_on_vt(sel_pos(pe, unicode)))			new_sel_end = pe;	}	if (vc_sel.start == -1)	/* no current selection */		highlight(new_sel_start, new_sel_end);	else if (new_sel_start == vc_sel.start)	{		if (new_sel_end == vc_sel.end)	/* no action required */			return 0;		else if (new_sel_end > vc_sel.end)	/* extend to right */			highlight(vc_sel.end + 2, new_sel_end);		else				/* contract from right */			highlight(new_sel_end + 2, vc_sel.end);	}	else if (new_sel_end == vc_sel.end)	{		if (new_sel_start < vc_sel.start) /* extend to left */			highlight(new_sel_start, vc_sel.start - 2);		else				/* contract from left */			highlight(vc_sel.start, new_sel_start - 2);	}	else	/* some other case; start selection from scratch */	{		clear_selection();		highlight(new_sel_start, new_sel_end);	}	vc_sel.start = new_sel_start;	vc_sel.end = new_sel_end; 	return vc_selection_store_chars(vc, unicode);} static int vc_selection(struct vc_data *vc, struct tiocl_selection *v,		struct tty_struct *tty){	int ps, pe; 	poke_blanked_console(); 	if (v->sel_mode == TIOCL_SELCLEAR) {		/* useful for screendump without selection highlights */		clear_selection();		return 0;	} 	/* Historically 0 => max value */	v->xs = umin(v->xs - 1, vc->vc_cols - 1);	v->ys = umin(v->ys - 1, vc->vc_rows - 1);	v->xe = umin(v->xe - 1, vc->vc_cols - 1);	v->ye = umin(v->ye - 1, vc->vc_rows - 1); 	if (mouse_reporting() && (v->sel_mode & TIOCL_SELMOUSEREPORT)) {		mouse_report(tty, v->sel_mode & TIOCL_SELBUTTONMASK, v->xs,			     v->ys);		return 0;	} 	ps = v->ys * vc->vc_size_row + (v->xs << 1);	pe = v->ye * vc->vc_size_row + (v->xe << 1);	if (ps > pe)	/* make vc_sel.start <= vc_sel.end */		swap(ps, pe); 	if (vc_sel.cons != vc) {		clear_selection();		vc_sel.cons = vc;	} 	return vc_do_selection(vc, v->sel_mode, ps, pe);} int set_selection_kernel(struct tiocl_selection *v, struct tty_struct *tty){	guard(mutex)(&vc_sel.lock);	guard(console_lock)();	return vc_selection(vc_cons[fg_console].d, v, tty);}EXPORT_SYMBOL_GPL(set_selection_kernel); /* Insert the contents of the selection buffer into the * queue of the tty associated with the current console. * Invoked by ioctl(). * * Locking: called without locks. Calls the ldisc wrongly with * unsafe methods, */int paste_selection(struct tty_struct *tty){	struct vc_data *vc = tty->driver_data;	int	pasted = 0;	size_t count;	struct  tty_ldisc *ld;	DECLARE_WAITQUEUE(wait, current);	int ret = 0; 	bool bp = vc->vc_bracketed_paste;	static const char bracketed_paste_start[] = "\033[200~";	static const char bracketed_paste_end[]   = "\033[201~";	const char *bps = bp ? bracketed_paste_start : NULL;	const char *bpe = bp ? bracketed_paste_end : NULL; 	scoped_guard(console_lock)		poke_blanked_console(); 	ld = tty_ldisc_ref_wait(tty);	if (!ld)		return -EIO;	/* ldisc was hung up */	tty_buffer_lock_exclusive(&vc->port); 	add_wait_queue(&vc->paste_wait, &wait);	mutex_lock(&vc_sel.lock);	while (vc_sel.buffer && (vc_sel.buf_len > pasted || bpe)) {		set_current_state(TASK_INTERRUPTIBLE);		if (signal_pending(current)) {			ret = -EINTR;			break;		}		if (tty_throttled(tty)) {			mutex_unlock(&vc_sel.lock);			schedule();			mutex_lock(&vc_sel.lock);			continue;		}		__set_current_state(TASK_RUNNING); 		if (bps) {			bps += tty_ldisc_receive_buf(ld, bps, NULL, strlen(bps));			if (*bps != '\0')				continue;			bps = NULL;		} 		count = vc_sel.buf_len - pasted;		if (count) {			pasted += tty_ldisc_receive_buf(ld, vc_sel.buffer + pasted,							NULL, count);			if (vc_sel.buf_len > pasted)				continue;		} 		if (bpe) {			bpe += tty_ldisc_receive_buf(ld, bpe, NULL, strlen(bpe));			if (*bpe == '\0')				bpe = NULL;		}	}	mutex_unlock(&vc_sel.lock);	remove_wait_queue(&vc->paste_wait, &wait);	__set_current_state(TASK_RUNNING); 	tty_buffer_unlock_exclusive(&vc->port);	tty_ldisc_deref(ld);	return ret;}EXPORT_SYMBOL_GPL(paste_selection);