conspy: add framebuffer support, -Q option.

Signed-off-by: Pascal Bellard <pascal.bellard@ads-lu.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

1 files changed, 71 insertions, 43 deletions

diff --git a/miscutils/conspy.c b/miscutils/conspy.c
index c6ed91832..1a46a4340 100644
--- a/miscutils/conspy.c
+++ b/miscutils/conspy.c
@@ -25,25 +25,31 @@
 //config:         or        conspy -cs NUM  poor man's GNU screen like
 
 //usage:#define conspy_trivial_usage
-//usage:        "[-vcsndf] [-x COL] [-y LINE] [CONSOLE_NO]"
+//usage:        "[-vcsndfFQ] [-x COL] [-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:     "\n        -v      Don't send keystrokes to the console"
-//usage:     "\n        -c      Create missing devices in /dev"
+//usage:     "\n        -c      Create missing /dev/{tty,vcsa}N"
 //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        -F      Assume console is on a framebuffer device"
+//usage:     "\n        -Q      Disable exit on ESC-ESC-ESC"
 //usage:     "\n        -x COL  Starting column"
 //usage:     "\n        -y LINE Starting line"
 
 #include "libbb.h"
 #include <sys/kd.h>
 
-
 #define ESC "\033"
+#define CURSOR_ON       -1
+#define CURSOR_OFF      1
+
+#define DEV_TTY         "/dev/tty"
+#define DEV_VCSA        "/dev/vcsa"
 
 struct screen_info {
         unsigned char lines, cols, cursor_x, cursor_y;
@@ -72,19 +78,17 @@ struct globals {
         unsigned col;
         unsigned line;
         smallint curoff; // unknown:0 cursor on:-1 cursor off:1
-        char attrbuf[sizeof(ESC"[0;1;5;30;40m")];
+        char attrbuf[sizeof("0;1;5;30;40m")];
         // remote console
         struct screen_info remote;
         // saved local tty terminfo
         struct termios term_orig;
-        char vcsa_name[sizeof("/dev/vcsaNN")];
+        char vcsa_name[sizeof(DEV_VCSA "NN")];
 };
 
 #define G (*ptr_to_globals)
 #define INIT_G() do { \
         SET_PTR_TO_GLOBALS(xzalloc(sizeof(G))); \
-        G.attrbuf[0] = '\033'; \
-        G.attrbuf[1] = '['; \
         G.width = G.height = UINT_MAX; \
         G.last_attr--; \
 } while (0)
@@ -92,18 +96,26 @@ struct globals {
 enum {
         FLAG_v,  // view only
         FLAG_c,  // create device if need
+        FLAG_Q,  // never exit
         FLAG_s,  // session
         FLAG_n,  // no colors
         FLAG_d,  // dump screen
         FLAG_f,  // follow cursor
+        FLAG_F,  // framebuffer
 };
 #define FLAG(x) (1 << FLAG_##x)
 #define BW (option_mask32 & FLAG(n))
 
+static void putcsi(const char *s)
+{
+        fputs(ESC"[", stdout);
+        fputs(s, stdout);
+}
+
 static void clrscr(void)
 {
         // Home, clear till end of screen
-        fputs(ESC"[1;1H" ESC"[J", stdout);
+        putcsi("1;1H" ESC"[J");
         G.col = G.line = 0;
 }
 
@@ -111,7 +123,7 @@ static void set_cursor(int state)
 {
         if (G.curoff != state) {
                 G.curoff = state;
-                fputs(ESC"[?25", stdout);
+                putcsi("?25");
                 bb_putchar("h?l"[1 + state]);
         }
 }
@@ -125,18 +137,19 @@ static void gotoxy(int col, int line)
         }
 }
 
+static void cleanup(int code) NORETURN;
 static void cleanup(int code)
 {
-        set_cursor(-1); // cursor on
+        set_cursor(CURSOR_ON);
         tcsetattr(G.kbd_fd, TCSANOW, &G.term_orig);
         if (ENABLE_FEATURE_CLEAN_UP) {
                 close(G.kbd_fd);
         }
         // Reset attributes
         if (!BW)
-                fputs(ESC"[0m", stdout);
+                putcsi("0m");
         bb_putchar('\n');
-        if (code > 1)
+        if (code > EXIT_FAILURE)
                 kill_myself_with_sig(code);
         exit(code);
 }
@@ -157,8 +170,8 @@ static void screen_read_close(void)
                 G.size = i;
                 G.data = xzalloc(2 * i);
         }
-        else if (G.size != i) {
-                cleanup(1);
+        if (G.size != i) {
+                cleanup(EXIT_FAILURE);
         }
         data = G.data + G.current;
         xread(vcsa_fd, data, G.size);
@@ -168,10 +181,15 @@ static void screen_read_close(void)
                         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;
+                        else {
+                                uint8_t ch = CHAR(data);
+                                if (ch < ' ')
+                                        CHAR(data) = ch | 0x40;
+                                else if (ch > 0x7e)
+                                        CHAR(data) = '?';
+                        }
                 }
         }
 }
@@ -179,10 +197,13 @@ static void screen_read_close(void)
 static void screen_char(char *data)
 {
         if (!BW) {
+                uint8_t attr_diff;
                 uint8_t attr = ATTR(data);
-                //uint8_t attr = ATTR(data) >> 1; // for framebuffer console
-                uint8_t attr_diff = G.last_attr ^ attr;
 
+                if (option_mask32 & FLAG(F)) {
+                        attr >>= 1;
+                }
+                attr_diff = G.last_attr ^ attr;
                 if (attr_diff) {
 // Attribute layout for VGA compatible text videobuffer:
 // blinking text
@@ -213,7 +234,7 @@ static void screen_char(char *data)
                         const uint8_t bg_mask = 0x70, blink_mask = 0x80;
                         char *ptr;
 
-                        ptr = G.attrbuf + 2; // skip "ESC ["
+                        ptr = G.attrbuf;
 
                         // (G.last_attr & ~attr) has 1 only where
                         // G.last_attr has 1 but attr has 0.
@@ -244,12 +265,12 @@ static void screen_char(char *data)
                         if (attr_diff & bg_mask) {
                                 *ptr++ = '4';
                                 *ptr++ = color[(attr & bg_mask) >> 4];
-                                *ptr++ = ';';
+                                ptr++; // last attribute
                         }
-                        if (ptr != G.attrbuf + 2) {
+                        if (ptr != G.attrbuf) {
                                 ptr[-1] = 'm';
                                 *ptr = '\0';
-                                fputs(G.attrbuf, stdout);
+                                putcsi(G.attrbuf);
                         }
                 }
         }
@@ -292,11 +313,11 @@ static void curmove(void)
 {
         unsigned cx = G.remote.cursor_x - G.x;
         unsigned cy = G.remote.cursor_y - G.y;
-        int cursor = 1;
+        int cursor = CURSOR_OFF;
 
         if (cx < G.width && cy < G.height) {
                 gotoxy(cx, cy);
-                cursor = -1;
+                cursor = CURSOR_ON;
         }
         set_cursor(cursor);
 }
@@ -341,7 +362,7 @@ static NOINLINE void start_shell_in_child(const char* tty_name)
 int conspy_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
 int conspy_main(int argc UNUSED_PARAM, char **argv)
 {
-        char tty_name[sizeof("/dev/ttyNN")];
+        char tty_name[sizeof(DEV_TTY "NN")];
 #define keybuf bb_common_bufsiz1
         struct termios termbuf;
         unsigned opts;
@@ -351,26 +372,28 @@ int conspy_main(int argc UNUSED_PARAM, char **argv)
         static const char getopt_longopts[] ALIGN1 =
                 "viewonly\0"     No_argument "v"
                 "createdevice\0" No_argument "c"
+                "neverquit\0"    No_argument "Q"
                 "session\0"      No_argument "s"
                 "nocolors\0"     No_argument "n"
                 "dump\0"         No_argument "d"
                 "follow\0"       No_argument "f"
+                "framebuffer\0"  No_argument "F"
                 ;
 
         applet_long_options = getopt_longopts;
 #endif
         INIT_G();
-        strcpy(G.vcsa_name, "/dev/vcsa");
+        strcpy(G.vcsa_name, DEV_VCSA);
 
         opt_complementary = "x+:y+"; // numeric params
-        opts = getopt32(argv, "vcsndfx:y:", &G.x, &G.y);
+        opts = getopt32(argv, "vcQsndfFx:y:", &G.x, &G.y);
         argv += optind;
         ttynum = 0;
         if (argv[0]) {
                 ttynum = xatou_range(argv[0], 0, 63);
-                sprintf(G.vcsa_name + sizeof("/dev/vcsa")-1, "%u", ttynum);
+                sprintf(G.vcsa_name + sizeof(DEV_VCSA)-1, "%u", ttynum);
         }
-        sprintf(tty_name, "%s%u", "/dev/tty", ttynum);
+        sprintf(tty_name, "%s%u", DEV_TTY, ttynum);
         if (opts & FLAG(c)) {
                 if ((opts & (FLAG(s)|FLAG(v))) != FLAG(v))
                         create_cdev_if_doesnt_exist(tty_name, makedev(4, ttynum));
@@ -481,7 +504,7 @@ int conspy_main(int argc UNUSED_PARAM, char **argv)
                         char *k;
                 case -1:
                         if (errno != EINTR)
-                                cleanup(1);
+                                goto abort;
                         break;
                 case 0:
                         if (++G.nokeys >= 4)
@@ -492,14 +515,16 @@ int conspy_main(int argc UNUSED_PARAM, char **argv)
                         k = keybuf + G.key_count;
                         bytes_read = read(G.kbd_fd, k, sizeof(keybuf) - G.key_count);
                         if (bytes_read < 0)
-                                cleanup(1);
+                                goto abort;
 
                         // Do exit processing
-                        for (i = 0; i < bytes_read; i++) {
-                                if (k[i] != '\033')
-                                        G.escape_count = 0;
-                                else if (++G.escape_count >= 3)
-                                        cleanup(0);
+                        if (!(option_mask32 & FLAG(Q))) {
+                                for (i = 0; i < bytes_read; i++) {
+                                        if (k[i] != '\033')
+                                                G.escape_count = -1;
+                                        if (++G.escape_count >= 3)
+                                                cleanup(EXIT_SUCCESS);
+                                }
                         }
                 }
                 poll_timeout_ms = 250;
@@ -519,6 +544,7 @@ int conspy_main(int argc UNUSED_PARAM, char **argv)
                         if (result >= 0) {
                                 char *p = keybuf;
 
+                                G.ioerror_count = 0;
                                 if (kbd_mode != K_XLATE && kbd_mode != K_UNICODE) {
                                         G.key_count = 0; // scan code mode
                                 }
@@ -534,16 +560,18 @@ int conspy_main(int argc UNUSED_PARAM, char **argv)
                                         poll_timeout_ms = 20;
                                 }
                         }
+                        // We sometimes get spurious IO errors on the TTY
+                        // as programs close and re-open it
+                        else if (errno != EIO || ++G.ioerror_count > 4) {
+                                if (ENABLE_FEATURE_CLEAN_UP)
+                                        close(handle);
+                                goto abort;
+                        }
                         // 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 >= 0)
-                                G.ioerror_count = 0;
-                        else if (errno != EIO || ++G.ioerror_count > 4)
-                                cleanup(1);
                 }
         } /* while (1) */
+  abort:
+        cleanup(EXIT_FAILURE);
 }