--- /dev/null
+/* vi: set sw=4 ts=4: */
+/*
+ * A text-mode VNC like program for Linux virtual terminals.
+ *
+ * pascal.bellard@ads-lu.com
+ *
+ * Based on Russell Stuart's conspy.c
+ * http://ace-host.stuart.id.au/russell/files/conspy.c
+ *
+ * Licensed under GPLv2 or later, see file License in this tarball for details.
+ *
+ * example : conspy num shared access to console num
+ * or conspy -d num screenshot of console num
+ * or conspy -cs num poor man's GNU screen like
+ */
+
+//applet:IF_CONSPY(APPLET(conspy, _BB_DIR_BIN, _BB_SUID_DROP))
+
+//kbuild:lib-$(CONFIG_CONSPY) += conspy.o
+
+//config:config CONSPY
+//config: bool "conspy"
+//config: default n
+//config: help
+//config: A text-mode VNC like program for Linux virtual terminals.
+//config: example : conspy num shared access to console num
+//config: or conspy -d num screenshot of console num
+//config: or conspy -cs num poor man's GNU screen like
+
+//usage:#define conspy_trivial_usage
+//usage: "[-vcsndf] [-x ROW] [-y LINE] [CONSOLE_NO]"
+//usage:#define conspy_full_usage "\n\n"
+//usage: "A text-mode VNC like program for Linux virtual consoles."
+//usage: "\nTo exit, quickly press ESC 3 times."
+//usage: "\n"
+//usage: "\nOptions:"
+//usage: "\n -v Don't send keystrokes to the console"
+//usage: "\n -c Create missing devices in /dev"
+//usage: "\n -s Open a SHELL session"
+//usage: "\n -n Black & white"
+//usage: "\n -d Dump console to stdout"
+//usage: "\n -f Follow cursor"
+//usage: "\n -x ROW Starting row"
+//usage: "\n -y LINE Starting line"
+
+#include "libbb.h"
+#include <sys/kd.h>
+
+struct screen_info {
+ unsigned char lines, rows, cursor_x, cursor_y;
+};
+
+#define CHAR(x) ((x)[0])
+#define ATTR(x) ((x)[1])
+#define NEXT(x) ((x)+=2)
+#define DATA(x) (* (short *) (x))
+
+struct globals {
+ char* data;
+ int size;
+ int x, y;
+ int kbd_fd;
+ unsigned width;
+ unsigned height;
+ char mask;
+ char last_attr;
+ struct screen_info info;
+ struct termios term_orig;
+};
+
+#define G (*ptr_to_globals)
+#define INIT_G() do { \
+ SET_PTR_TO_GLOBALS(xzalloc(sizeof(G))); \
+} while (0)
+
+static void screen_read_close(int fd, char *data)
+{
+ unsigned i, j;
+
+ xread(fd, data, G.size);
+ G.last_attr = 0;
+ for (i = 0; i < G.info.lines; i++) {
+ for (j = 0; j < G.info.rows; j++, NEXT(data)) {
+ unsigned x = j - G.x; // if will catch j < G.x too
+ unsigned y = i - G.y; // if will catch i < G.y too
+
+ if (CHAR(data) < ' ')
+ CHAR(data) = ' ';
+ if (y >= G.height || x >= G.width)
+ DATA(data) = 0;
+ }
+ }
+ close(fd);
+}
+
+static void screen_char(char *data)
+{
+ if (((G.last_attr - ATTR(data)) & G.mask) != 0) {
+ // BLGCRMOW
+ static const char color[8] = "04261537";
+
+ printf("\033[%c;4%c;3%cm",
+ (ATTR(data) & 8) ? '1' // bold
+ : '0', // defaults
+ color[(ATTR(data) >> 4) & 7], color[ATTR(data) & 7]);
+ G.last_attr = ATTR(data);
+ }
+ bb_putchar(CHAR(data));
+}
+
+#define clrscr() printf("\033[1;1H" "\033[0J")
+#define curoff() printf("\033[?25l")
+
+static void curon(void)
+{
+ printf("\033[?25h");
+}
+
+static void gotoxy(int row, int line)
+{
+ printf("\033[%u;%uH", line + 1, row + 1);
+}
+
+static void screen_dump(char *data)
+{
+ int space, linefeed, line, row;
+ int linecnt = G.info.lines - G.y;
+
+ data += 2 * G.y * G.info.rows;
+ for (linefeed = line = 0; line < linecnt && line < G.height; line++) {
+ for (space = row = 0; row < G.info.rows; row++, NEXT(data)) {
+ unsigned tty_row = row - G.x; // if will catch row < G.x too
+
+ if (tty_row >= G.width)
+ continue;
+ space++;
+ if (((G.last_attr - ATTR(data)) & G.mask) && CHAR(data) == ' ')
+ continue;
+ while (linefeed != 0) {
+ bb_putchar('\r');
+ bb_putchar('\n');
+ linefeed--;
+ }
+ while (--space)
+ bb_putchar(' ');
+ screen_char(data);
+ }
+ linefeed++;
+ }
+}
+
+static void curmove(void)
+{
+ unsigned cx = G.info.cursor_x - G.x;
+ unsigned cy = G.info.cursor_y - G.y;
+
+ if (cx >= G.width || cy >= G.height) {
+ curoff();
+ } else {
+ curon();
+ gotoxy(cx, cy);
+ }
+ fflush_all();
+}
+
+static void cleanup(int code)
+{
+ curon();
+ fflush_all();
+ tcsetattr(G.kbd_fd, TCSANOW, &G.term_orig);
+ if (ENABLE_FEATURE_CLEAN_UP) {
+ free(ptr_to_globals);
+ close(G.kbd_fd);
+ }
+ // Reset attributes
+ if (G.mask != 0)
+ printf("\033[0m");
+ bb_putchar('\n');
+ if (code > 1)
+ kill_myself_with_sig(code); // does not return
+ exit(code);
+}
+
+static void get_initial_data(const char* vcsa_name)
+{
+ int size;
+ int fd = xopen(vcsa_name, O_RDONLY);
+ xread(fd, &G.info, 4);
+ G.size = size = G.info.rows * G.info.lines * 2;
+ G.width = G.height = UINT_MAX;
+ G.data = xzalloc(2 * size);
+ screen_read_close(fd, G.data);
+}
+
+static void create_cdev_if_doesnt_exist(const char* name, dev_t dev)
+{
+ int fd = open(name, O_RDONLY);
+ if (fd != -1)
+ close(fd);
+ else if (errno == ENOENT)
+ mknod(name, S_IFCHR | 0660, dev);
+}
+
+static NOINLINE void start_shell_in_child(const char* tty_name)
+{
+ int pid = vfork();
+ if (pid < 0) {
+ bb_perror_msg_and_die("vfork");
+ }
+ if (pid == 0) {
+ struct termios termchild;
+ char *shell = getenv("SHELL");
+
+ if (!shell)
+ shell = (char *) DEFAULT_SHELL;
+ signal(SIGHUP, SIG_IGN);
+ // set tty as a controlling tty
+ setsid();
+ // make tty to be input, output, error
+ close(0);
+ xopen(tty_name, O_RDWR); // uses fd 0
+ xdup2(0, 1);
+ xdup2(0, 2);
+ ioctl(0, TIOCSCTTY, 1);
+ tcsetpgrp(0, getpid());
+ tcgetattr(0, &termchild);
+ termchild.c_lflag |= ECHO;
+ termchild.c_oflag |= ONLCR | XTABS;
+ termchild.c_iflag |= ICRNL;
+ termchild.c_iflag &= ~IXOFF;
+ tcsetattr_stdin_TCSANOW(&termchild);
+ execl(shell, shell, "-i", (char *) NULL);
+ bb_simple_perror_msg_and_die(shell);
+ }
+}
+
+enum {
+ FLAG_v, // view only
+ FLAG_c, // create device if need
+ FLAG_s, // session
+ FLAG_n, // no colors
+ FLAG_d, // dump screen
+ FLAG_f, // follow cursor
+};
+#define FLAG(x) (1 << FLAG_##x)
+
+int conspy_main(int argc UNUSED_PARAM, char **argv) MAIN_EXTERNALLY_VISIBLE;
+int conspy_main(int argc UNUSED_PARAM, char **argv)
+{
+ char *buffer[2];
+ char vcsa_name[sizeof("/dev/vcsa") + 2];
+ char tty_name[sizeof("/dev/tty") + 2];
+#define keybuf bb_common_bufsiz1
+ struct termios termbuf;
+ unsigned opts;
+ unsigned ttynum;
+ int poll_timeout_ms;
+ int current;
+ int ioerror_count;
+ int key_count;
+ int escape_count;
+ int nokeys;
+#if ENABLE_LONG_OPTS
+ static const char getopt_longopts[] ALIGN1 =
+ "viewonly\0" No_argument "v"
+ "createdevice\0" No_argument "c"
+ "session\0" No_argument "s"
+ "nocolors\0" No_argument "n"
+ "dump\0" No_argument "d"
+ "follow\0" No_argument "f"
+ ;
+
+ applet_long_options = getopt_longopts;
+#endif
+ INIT_G();
+ strcpy(vcsa_name, "/dev/vcsa");
+
+ opt_complementary = "x+:y+"; // numeric params
+ opts = getopt32(argv, "vcsndfx:y:", &G.x, &G.y);
+ argv += optind;
+ ttynum = 0;
+ if (argv[0]) {
+ ttynum = xatou_range(argv[0], 0, 63);
+ sprintf(vcsa_name + sizeof("/dev/vcsa")-1, "%u", ttynum);
+ }
+ sprintf(tty_name, "%s%u", "/dev/tty", ttynum);
+ if (!(opts & FLAG(n)))
+ G.mask = 0xff;
+ if (opts & FLAG(c)) {
+ if ((opts & (FLAG(s)|FLAG(v))) != FLAG(v))
+ create_cdev_if_doesnt_exist(tty_name, makedev(4, ttynum));
+ create_cdev_if_doesnt_exist(vcsa_name, makedev(7, 128 + ttynum));
+ }
+ if ((opts & FLAG(s)) && ttynum) {
+ start_shell_in_child(tty_name);
+ }
+
+ get_initial_data(vcsa_name);
+ G.kbd_fd = xopen(CURRENT_TTY, O_RDONLY);
+ if (opts & FLAG(d)) {
+ screen_dump(G.data);
+ bb_putchar('\n');
+ if (ENABLE_FEATURE_CLEAN_UP) {
+ free(ptr_to_globals);
+ close(G.kbd_fd);
+ }
+ return 0;
+ }
+
+ bb_signals(BB_FATAL_SIGS, cleanup);
+ // All characters must be passed through to us unaltered
+ tcgetattr(G.kbd_fd, &G.term_orig);
+ termbuf = G.term_orig;
+ termbuf.c_iflag &= ~(BRKINT|INLCR|ICRNL|IXON|IXOFF|IUCLC|IXANY|IMAXBEL);
+ termbuf.c_oflag &= ~(OPOST);
+ termbuf.c_lflag &= ~(ISIG|ICANON|ECHO);
+ termbuf.c_cc[VMIN] = 1;
+ termbuf.c_cc[VTIME] = 0;
+ tcsetattr(G.kbd_fd, TCSANOW, &termbuf);
+ buffer[0] = G.data;
+ buffer[1] = G.data + G.size;
+ poll_timeout_ms = 250;
+ ioerror_count = key_count = escape_count = nokeys = current = 0;
+ while (1) {
+ struct pollfd pfd;
+ int vcsa_handle;
+ int bytes_read;
+ int i, j;
+ int next = 1 - current;
+ char *data = buffer[next];
+ char *old = buffer[current];
+
+ // Close & re-open vcsa in case they have
+ // swapped virtual consoles
+ vcsa_handle = xopen(vcsa_name, O_RDONLY);
+ xread(vcsa_handle, &G.info, 4);
+ if (G.size != (G.info.rows * G.info.lines * 2)) {
+ cleanup(1);
+ }
+ i = G.width;
+ j = G.height;
+ get_terminal_width_height(G.kbd_fd, &G.width, &G.height);
+ if ((option_mask32 & FLAG(f))) {
+ int nx = G.info.cursor_x - G.width + 1;
+ int ny = G.info.cursor_y - G.height + 1;
+
+ if (G.info.cursor_x < G.x) {
+ G.x = G.info.cursor_x;
+ i = 0; // force refresh
+ }
+ if (nx > G.x) {
+ G.x = nx;
+ i = 0; // force refresh
+ }
+ if (G.info.cursor_y < G.y) {
+ G.y = G.info.cursor_y;
+ i = 0; // force refresh
+ }
+ if (ny > G.y) {
+ G.y = ny;
+ i = 0; // force refresh
+ }
+ }
+
+ // Scan console data and redraw our tty where needed
+ screen_read_close(vcsa_handle, data);
+ if (i != G.width || j != G.height) {
+ clrscr();
+ screen_dump(data);
+ }
+ else for (i = 0; i < G.info.lines; i++) {
+ char *last = last;
+ char *first = NULL;
+ int iy = i - G.y;
+
+ if (iy >= (int) G.height)
+ break;
+ for (j = 0; j < G.info.rows; j++) {
+ last = data;
+ if (DATA(data) != DATA(old) && iy >= 0) {
+ unsigned jx = j - G.x;
+
+ last = NULL;
+ if (first == NULL && jx < G.width) {
+ first = data;
+ gotoxy(jx, iy);
+ }
+ }
+ NEXT(old);
+ NEXT(data);
+ }
+ if (first == NULL)
+ continue;
+ if (last == NULL)
+ last = data;
+
+ // Write the data to the screen
+ for (; first < last; NEXT(first))
+ screen_char(first);
+ }
+ current = next;
+ curmove();
+
+ // Wait for local user keypresses
+ pfd.fd = G.kbd_fd;
+ pfd.events = POLLIN;
+ bytes_read = 0;
+ switch (poll(&pfd, 1, poll_timeout_ms)) {
+ case -1:
+ if (errno != EINTR)
+ cleanup(1);
+ break;
+ case 0:
+ if (++nokeys >= 4)
+ nokeys = escape_count = 0;
+ break;
+ default:
+ // Read the keys pressed
+ bytes_read = read(G.kbd_fd, keybuf + key_count,
+ sizeof(keybuf) - key_count);
+ if (bytes_read < 0)
+ cleanup(1);
+
+ // Do exit processing
+ for (i = 0; i < bytes_read; i++) {
+ if (keybuf[key_count + i] != '\033')
+ escape_count = 0;
+ else if (++escape_count >= 3)
+ cleanup(0);
+ }
+ }
+ poll_timeout_ms = 250;
+
+ // Insert all keys pressed into the virtual console's input
+ // buffer. Don't do this if the virtual console is in scan
+ // code mode - giving ASCII characters to a program expecting
+ // scan codes will confuse it.
+ if (!(option_mask32 & FLAG(v)) && escape_count == 0) {
+ int handle, result;
+ long kbd_mode;
+
+ key_count += bytes_read;
+ handle = xopen(tty_name, O_WRONLY);
+ result = ioctl(handle, KDGKBMODE, &kbd_mode);
+ if (result == -1)
+ /* nothing */;
+ else if (kbd_mode != K_XLATE && kbd_mode != K_UNICODE)
+ key_count = 0; // scan code mode
+ else {
+ for (i = 0; i < key_count && result != -1; i++)
+ result = ioctl(handle, TIOCSTI, keybuf + i);
+ key_count -= i;
+ if (key_count)
+ memmove(keybuf, keybuf + i, key_count);
+ // If there is an application on console which reacts
+ // to keypresses, we need to make our first sleep
+ // shorter to quickly redraw whatever it printed there.
+ poll_timeout_ms = 20;
+ }
+ // Close & re-open tty in case they have
+ // swapped virtual consoles
+ close(handle);
+
+ // We sometimes get spurious IO errors on the TTY
+ // as programs close and re-open it
+ if (result != -1)
+ ioerror_count = 0;
+ else if (errno != EIO || ++ioerror_count > 4)
+ cleanup(1);
+ }
+ }
+}
projects / oweals / busybox.git / commitdiff