diff options
Diffstat (limited to 'drivers/tty/vt/selection.c')
| -rw-r--r-- | drivers/tty/vt/selection.c | 401 |
1 files changed, 401 insertions, 0 deletions
diff --git a/drivers/tty/vt/selection.c b/drivers/tty/vt/selection.c new file mode 100644 index 000000000..34a0e529c --- /dev/null +++ b/drivers/tty/vt/selection.c @@ -0,0 +1,401 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * This module exports the functions: + * + * 'int set_selection(struct tiocl_selection __user *, struct tty_struct *)' + * 'void clear_selection(void)' + * 'int paste_selection(struct tty_struct *)' + * 'int sel_loadlut(char __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 isspace(c) ((c) == ' ') + +extern void poke_blanked_console(void); + +/* FIXME: all this needs locking */ +/* Variables for selection control. */ +/* Use a dynamic buffer, instead of static (Dec 1994) */ +struct vc_data *sel_cons; /* must not be deallocated */ +static int use_unicode; +static volatile int sel_start = -1; /* cleared by clear_selection */ +static int sel_end; +static int sel_buffer_lth; +static char *sel_buffer; +static DEFINE_MUTEX(sel_lock); + +/* 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(sel_cons, s, e-s+2, 1); +} + +/* use complementary color to show the pointer */ +static inline void highlight_pointer(const int where) +{ + complement_pos(sel_cons, where); +} + +static u32 +sel_pos(int n) +{ + if (use_unicode) + return screen_glyph_unicode(sel_cons, n / 2); + return inverse_translate(sel_cons, screen_glyph(sel_cons, n), + 0); +} + +/** + * clear_selection - remove current selection + * + * Remove the current selection highlight, if any from the console + * holding the selection. The caller must hold the console lock. + */ +void clear_selection(void) +{ + highlight_pointer(-1); /* hide the pointer */ + if (sel_start != -1) { + highlight(sel_start, sel_end); + sel_start = -1; + } +} + +bool vc_is_sel(struct vc_data *vc) +{ + return 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); +} + +/** + * set loadlut - load the LUT table + * @p: user table + * + * Load the LUT table from user space. The caller must hold the console + * lock. Make a temporary copy so a partial update doesn't make a mess. + */ +int sel_loadlut(char __user *p) +{ + u32 tmplut[ARRAY_SIZE(inwordLut)]; + if (copy_from_user(tmplut, (u32 __user *)(p+4), sizeof(inwordLut))) + return -EFAULT; + 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 - set the current selection. + * @sel: user selection info + * @tty: the console tty + * + * Invoked by the ioctl handle for the vt layer. + * + * The entire selection process is managed under the console_lock. It's + * a lot under the lock but its hardly a performance path + */ +static int __set_selection(const struct tiocl_selection __user *sel, struct tty_struct *tty) +{ + struct vc_data *vc = vc_cons[fg_console].d; + int new_sel_start, new_sel_end, spc; + struct tiocl_selection v; + char *bp, *obp; + int i, ps, pe, multiplier; + u32 c; + int mode, ret = 0; + + poke_blanked_console(); + if (copy_from_user(&v, sel, sizeof(*sel))) + return -EFAULT; + + v.xs = min_t(u16, v.xs - 1, vc->vc_cols - 1); + v.ys = min_t(u16, v.ys - 1, vc->vc_rows - 1); + v.xe = min_t(u16, v.xe - 1, vc->vc_cols - 1); + v.ye = min_t(u16, v.ye - 1, vc->vc_rows - 1); + ps = v.ys * vc->vc_size_row + (v.xs << 1); + pe = v.ye * vc->vc_size_row + (v.xe << 1); + + if (v.sel_mode == TIOCL_SELCLEAR) { + /* useful for screendump without selection highlights */ + clear_selection(); + return 0; + } + + if (mouse_reporting() && (v.sel_mode & TIOCL_SELMOUSEREPORT)) { + mouse_report(tty, v.sel_mode & TIOCL_SELBUTTONMASK, v.xs, v.ys); + return 0; + } + + if (ps > pe) /* make sel_start <= sel_end */ + swap(ps, pe); + + if (sel_cons != vc_cons[fg_console].d) { + clear_selection(); + sel_cons = vc_cons[fg_console].d; + } + mode = vt_do_kdgkbmode(fg_console); + if (mode == K_UNICODE) + use_unicode = 1; + else + use_unicode = 0; + + switch (v.sel_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 = isspace(sel_pos(ps)); + for (new_sel_start = ps; ; ps -= 2) + { + if ((spc && !isspace(sel_pos(ps))) || + (!spc && !inword(sel_pos(ps)))) + break; + new_sel_start = ps; + if (!(ps % vc->vc_size_row)) + break; + } + spc = isspace(sel_pos(pe)); + for (new_sel_end = pe; ; pe += 2) + { + if ((spc && !isspace(sel_pos(pe))) || + (!spc && !inword(sel_pos(pe)))) + break; + new_sel_end = pe; + if (!((pe + 2) % vc->vc_size_row)) + break; + } + break; + case TIOCL_SELLINE: /* line-by-line selection */ + new_sel_start = ps - ps % vc->vc_size_row; + new_sel_end = pe + vc->vc_size_row + - pe % 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) && + isspace(sel_pos(new_sel_end))) { + for (pe = new_sel_end + 2; ; pe += 2) + if (!isspace(sel_pos(pe)) || + atedge(pe, vc->vc_size_row)) + break; + if (isspace(sel_pos(pe))) + new_sel_end = pe; + } + if (sel_start == -1) /* no current selection */ + highlight(new_sel_start, new_sel_end); + else if (new_sel_start == sel_start) + { + if (new_sel_end == sel_end) /* no action required */ + return 0; + else if (new_sel_end > sel_end) /* extend to right */ + highlight(sel_end + 2, new_sel_end); + else /* contract from right */ + highlight(new_sel_end + 2, sel_end); + } + else if (new_sel_end == sel_end) + { + if (new_sel_start < sel_start) /* extend to left */ + highlight(new_sel_start, sel_start - 2); + else /* contract from left */ + highlight(sel_start, new_sel_start - 2); + } + else /* some other case; start selection from scratch */ + { + clear_selection(); + highlight(new_sel_start, new_sel_end); + } + sel_start = new_sel_start; + sel_end = new_sel_end; + + /* Allocate a new buffer before freeing the old one ... */ + multiplier = use_unicode ? 4 : 1; /* chars can take up to 4 bytes */ + bp = kmalloc_array((sel_end - sel_start) / 2 + 1, multiplier, + GFP_KERNEL); + if (!bp) { + printk(KERN_WARNING "selection: kmalloc() failed\n"); + clear_selection(); + return -ENOMEM; + } + kfree(sel_buffer); + sel_buffer = bp; + + obp = bp; + for (i = sel_start; i <= sel_end; i += 2) { + c = sel_pos(i); + if (use_unicode) + bp += store_utf8(c, bp); + else + *bp++ = c; + if (!isspace(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; + } + } + sel_buffer_lth = bp - sel_buffer; + + return ret; +} + +int set_selection(const struct tiocl_selection __user *v, struct tty_struct *tty) +{ + int ret; + + mutex_lock(&sel_lock); + console_lock(); + ret = __set_selection(v, tty); + console_unlock(); + mutex_unlock(&sel_lock); + + return ret; +} + +/* 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; + unsigned int count; + struct tty_ldisc *ld; + DECLARE_WAITQUEUE(wait, current); + int ret = 0; + + console_lock(); + poke_blanked_console(); + console_unlock(); + + 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(&sel_lock); + while (sel_buffer && sel_buffer_lth > pasted) { + set_current_state(TASK_INTERRUPTIBLE); + if (signal_pending(current)) { + ret = -EINTR; + break; + } + if (tty_throttled(tty)) { + mutex_unlock(&sel_lock); + schedule(); + mutex_lock(&sel_lock); + continue; + } + __set_current_state(TASK_RUNNING); + count = sel_buffer_lth - pasted; + count = tty_ldisc_receive_buf(ld, sel_buffer + pasted, NULL, + count); + pasted += count; + } + mutex_unlock(&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; +} |