Files
systemd/src/shared/qrcode-util.c
2024-10-29 09:41:54 +01:00

239 lines
9.0 KiB
C

/* SPDX-License-Identifier: LGPL-2.1-or-later */
#include "qrcode-util.h"
#if HAVE_QRENCODE
#include <qrencode.h>
#include "ansi-color.h"
#include "dlfcn-util.h"
#include "locale-util.h"
#include "log.h"
#include "strv.h"
#include "terminal-util.h"
#define ANSI_WHITE_ON_BLACK "\033[40;37;1m"
#define UNICODE_FULL_BLOCK u8"█"
#define UNICODE_LOWER_HALF_BLOCK u8"▄"
#define UNICODE_UPPER_HALF_BLOCK u8"▀"
static void *qrcode_dl = NULL;
static DLSYM_PROTOTYPE(QRcode_encodeString) = NULL;
static DLSYM_PROTOTYPE(QRcode_free) = NULL;
int dlopen_qrencode(void) {
int r;
ELF_NOTE_DLOPEN("qrencode",
"Support for generating QR codes",
ELF_NOTE_DLOPEN_PRIORITY_SUGGESTED,
"libqrencode.so.4", "libqrencode.so.3");
FOREACH_STRING(s, "libqrencode.so.4", "libqrencode.so.3") {
r = dlopen_many_sym_or_warn(
&qrcode_dl, s, LOG_DEBUG,
DLSYM_ARG(QRcode_encodeString),
DLSYM_ARG(QRcode_free));
if (r >= 0)
break;
}
return r;
}
static void print_border(FILE *output, unsigned width, unsigned row, unsigned column) {
assert(output);
assert(width);
if (row != UINT_MAX && column != UINT_MAX) {
int r, fd;
fd = fileno(output);
if (fd < 0)
return (void)log_debug_errno(errno, "Failed to get file descriptor from the file stream: %m");
r = terminal_set_cursor_position(fd, row, column);
if (r < 0)
log_warning_errno(r, "Failed to move terminal cursor position, ignoring: %m");
/* Four rows of border */
for (unsigned y = 0; y < 4; y += 2) {
fputs(ANSI_WHITE_ON_BLACK, output);
for (unsigned x = 0; x < 4 + width + 4; x++)
fputs(UNICODE_FULL_BLOCK, output);
fputs(ANSI_NORMAL "\n", output);
r = terminal_set_cursor_position(fd, row + 1, column);
if (r < 0)
log_warning_errno(r, "Failed to move terminal cursor position, ignoring: %m");
}
} else {
/* Four rows of border */
for (unsigned y = 0; y < 4; y += 2) {
fputs(ANSI_WHITE_ON_BLACK, output);
for (unsigned x = 0; x < 4 + width + 4; x++)
fputs(UNICODE_FULL_BLOCK, output);
fputs(ANSI_NORMAL "\n", output);
}
}
}
static void write_qrcode(FILE *output, QRcode *qr, unsigned int row, unsigned int column) {
assert(qr);
if (!output)
output = stdout;
print_border(output, qr->width, row, column);
if (row != UINT_MAX && column != UINT_MAX) {
/* After printing two rows of top border, we need to move the cursor down two rows before starting to print the actual QR code */
int r, fd, move_down = 2;
fd = fileno(output);
if (fd < 0)
return (void)log_debug_errno(errno, "Failed to get file descriptor from the file stream: %m");
r = terminal_set_cursor_position(fd, row + move_down, column);
if (r < 0)
log_warning_errno(r, "Failed to move terminal cursor position, ignoring: %m");
for (unsigned y = 0; y < (unsigned) qr->width; y += 2) {
const uint8_t *row1 = qr->data + qr->width * y;
const uint8_t *row2 = row1 + qr->width;
fputs(ANSI_WHITE_ON_BLACK, output);
for (unsigned x = 0; x < 4; x++)
fputs(UNICODE_FULL_BLOCK, output);
for (unsigned x = 0; x < (unsigned) qr->width; x++) {
bool a, b;
a = row1[x] & 1;
b = (y+1) < (unsigned) qr->width ? (row2[x] & 1) : false;
if (a && b)
fputc(' ', output);
else if (a)
fputs(UNICODE_LOWER_HALF_BLOCK, output);
else if (b)
fputs(UNICODE_UPPER_HALF_BLOCK, output);
else
fputs(UNICODE_FULL_BLOCK, output);
}
for (unsigned x = 0; x < 4; x++)
fputs(UNICODE_FULL_BLOCK, output);
r = terminal_set_cursor_position(fd, row + move_down, column);
if (r < 0)
log_warning_errno(r, "Failed to move terminal cursor position, ignoring: %m");
move_down += 1;
fputs(ANSI_NORMAL "\n", output);
}
print_border(output, qr->width, row + move_down, column);
} else {
for (unsigned y = 0; y < (unsigned) qr->width; y += 2) {
const uint8_t *row1 = qr->data + qr->width * y;
const uint8_t *row2 = row1 + qr->width;
fputs(ANSI_WHITE_ON_BLACK, output);
for (unsigned x = 0; x < 4; x++)
fputs(UNICODE_FULL_BLOCK, output);
for (unsigned x = 0; x < (unsigned) qr->width; x++) {
bool a, b;
a = row1[x] & 1;
b = (y+1) < (unsigned) qr->width ? (row2[x] & 1) : false;
if (a && b)
fputc(' ', output);
else if (a)
fputs(UNICODE_LOWER_HALF_BLOCK, output);
else if (b)
fputs(UNICODE_UPPER_HALF_BLOCK, output);
else
fputs(UNICODE_FULL_BLOCK, output);
}
for (unsigned x = 0; x < 4; x++)
fputs(UNICODE_FULL_BLOCK, output);
fputs(ANSI_NORMAL "\n", output);
}
print_border(output, qr->width, row, column);
}
fflush(output);
}
DEFINE_TRIVIAL_CLEANUP_FUNC_FULL(QRcode*, sym_QRcode_free, NULL);
int print_qrcode_full(
FILE *out,
const char *header,
const char *string,
unsigned row,
unsigned column,
unsigned tty_width,
unsigned tty_height,
bool check_tty) {
int r;
/* If this is not a UTF-8 system or ANSI colors aren't supported/disabled don't print any QR
* codes */
if (!is_locale_utf8())
return log_debug_errno(SYNTHETIC_ERRNO(EOPNOTSUPP), "Not an UTF-8 system, cannot print qrcode");
if (check_tty && !colors_enabled())
return log_debug_errno(SYNTHETIC_ERRNO(EOPNOTSUPP), "Colors are disabled, cannot print qrcode");
r = dlopen_qrencode();
if (r < 0)
return r;
_cleanup_(sym_QRcode_freep) QRcode *qr =
sym_QRcode_encodeString(string, 0, QR_ECLEVEL_L, QR_MODE_8, 1);
if (!qr)
return log_oom_debug();
if (row != UINT_MAX && column != UINT_MAX) {
unsigned qr_code_width, qr_code_height;
int fd = fileno(out);
if (fd < 0)
return log_debug_errno(errno, "Failed to get file descriptor from the file stream: %m");
qr_code_width = qr_code_height = qr->width + 8;
if (column + qr_code_width > tty_width)
column = tty_width - qr_code_width;
/* Terminal characters are twice as high as they are wide so it's qr_code_height / 2,
* our QR code prints an extra new line, so we have -1 as well */
if (row + qr_code_height > tty_height)
row = tty_height - (qr_code_height / 2 ) - 1;
if (header) {
r = terminal_set_cursor_position(fd, row - 2, tty_width - qr_code_width - 2);
if (r < 0)
log_warning_errno(r, "Failed to move terminal cursor position, ignoring: %m");
fprintf(out, "%s:\n\n", header);
}
} else
if (header)
fprintf(out, "\n%s:\n\n", header);
write_qrcode(out, qr, row, column);
fputc('\n', out);
return 0;
}
#endif