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| -rw-r--r-- | miscutils/conspy.c | 472 |
1 files changed, 472 insertions, 0 deletions
diff --git a/miscutils/conspy.c b/miscutils/conspy.c new file mode 100644 index 000000000..7ba7959a2 --- /dev/null +++ b/miscutils/conspy.c @@ -0,0 +1,472 @@ +/* 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); + } + } +} |