kern/48360: wskbd - support for cn_magic

[nathanialsloss%yahoo.com.au@localhost]

>Number:         48360
>Category:       kern
>Synopsis:       wskbd - support for cn_magic
>Confidential:   no
>Severity:       non-critical
>Priority:       medium
>Responsible:    kern-bug-people
>State:          open
>Class:          change-request
>Submitter-Id:   net
>Arrival-Date:   Sat Nov 02 09:45:00 +0000 2013
>Originator:     Nat Sloss
>Release:        NetBSD 6.1.1
>Organization:
>Environment:
NetBSD beast 6.1.1_PATCH NetBSD 6.1.1_PATCH (PCIPAE) #13: Sat Nov  2 18:07:05 
EST 2013  build@test:/usr/src/sys/arch/i386/compile/obj/PCIPAE i386
>Description:
wscons does not support cn_magic - setting hw.cnmagic has no effect.

So I have a simple patch that adds support, although it probably needs some 
reworking.

Also I did not know the byte sequence for C-A-Esc so I used KS_Cmd_Debugger.  
As a consequence the debugger can also be entered with " (curcumflex modifier)" 
KS_circumflex, which I did not know how to enter from my keyboard in /bin/ksh.

But Apart from that it works well.

I also found that even without this patch the debugger can be entered from any 
virtual terminal except  vt5 (used for x windows) this was not the case in 
NetBSD 5.0.1.


>How-To-Repeat:
Refer to above.
>Fix:
Apply this patch:
Index: src/sys/dev/wscons/wskbd.c
===================================================================
RCS file: /cvsroot/src/sys/dev/wscons/wskbd.c,v
retrieving revision 1.130
diff -u -r1.130 wskbd.c
--- src/sys/dev/wscons/wskbd.c  26 Oct 2010 05:12:34 -0000      1.130
+++ src/sys/dev/wscons/wskbd.c  2 Nov 2013 09:23:10 -0000
@@ -207,6 +207,7 @@
 
        wskbd_hotkey_plugin *sc_hotkey;
        void *sc_hotkeycookie;
+       dev_t           cn_magicdev;    /* device for cnmagic */
 };
 
 #define MOD_SHIFT_L            (1 << 0)
@@ -241,6 +242,19 @@
                dst |= (src & MOD_META_L) ? MOD_META_L : 0; \
                dst |= (src & MOD_META_R) ? MOD_META_R : 0; \
        } while (0)
+#define ws_check_magic(k, s)                                           \
+       do {                                                            \
+                       int _v = (s).cnm_magic[(s).cnm_state];          \
+                       if ((k) == CNS_MAGIC_VAL(_v)) {                 \
+                               (s).cnm_state = CNS_MAGIC_NEXT(_v);     \
+                               if ((s).cnm_state == CNS_TERM) {        \
+                                       cn_trap();                      \
+                                       (s).cnm_state = 0;              \
+                               }                                       \
+                       } else {                                        \
+                               (s).cnm_state = 0;                      \
+                       }                                               \
+       } while (/* CONSTCOND */ 0)
 
 static int  wskbd_match(device_t, cfdata_t, void *);
 static void wskbd_attach(device_t, device_t, void *);
@@ -350,6 +364,9 @@
 static bool wskbd_suspend(device_t dv, const pmf_qual_t *);
 static void wskbd_repeat(void *v);
 
+#include <dev/cons.h>
+static struct cnm_state ws_cnm_state;
+
 static int wskbd_console_initted;
 static struct wskbd_softc *wskbd_console_device;
 static struct wskbd_internal wskbd_console_data;
@@ -438,6 +455,11 @@
 
        if (ap->console) {
                sc->id = &wskbd_console_data;
+
+               sc->cn_magicdev = cn_tab->cn_dev;
+               cn_init_magic(&ws_cnm_state);
+               cn_set_magic("\x20\xf4"); /* default magic */
+
        } else {
                sc->id = malloc(sizeof(struct wskbd_internal),
                                M_DEVBUF, M_WAITOK|M_ZERO);
@@ -526,7 +548,7 @@
 
        wskbd_console_data.t_consops = consops;
        wskbd_console_data.t_consaccesscookie = conscookie;
-
+       
 #if NWSDISPLAY > 0
        wsdisplay_set_cons_kbd(wskbd_cngetc, wskbd_cnpollc, wskbd_cnbell);
 #endif
@@ -1583,7 +1605,9 @@
                return (0);
 
 #if defined(DDB) || defined(KGDB)
+
        if (ksym == KS_Cmd_Debugger) {
+#if 0
                if (sc->sc_isconsole) {
 #ifdef DDB
                        console_debugger();
@@ -1592,6 +1616,7 @@
                        kgdb_connect(1);
 #endif
                }
+#endif
                /* discard this key (ddb discarded command modifiers) */
                *type = WSCONS_EVENT_KEY_UP;
                return (1);
@@ -1713,9 +1738,17 @@
        }
 
        /* if this key has a command, process it first */
-       if (sc != NULL && kp->command != KS_voidSymbol)
+       if (sc != NULL && kp->command != KS_voidSymbol) {
                iscommand = internal_command(sc, &type, kp->command,
                                             kp->group1[0]);
+               if (sc->sc_isconsole && iscommand) {
+                       if (kp->command & 0xff)
+                               ws_check_magic((kp->command & 0xff), 
ws_cnm_state);
+                       if ((kp->command >> 8) & 0xff)
+                               ws_check_magic(((kp->command >> 8) & 0xff), 
ws_cnm_state);
+               }
+
+       }
 
        /* Now update modifiers */
        switch (kp->group1[0]) {
@@ -1868,12 +1901,32 @@
                        if (id->t_flags & WSKFL_METAESC) {
                                id->t_symbols[0] = KS_Escape;
                                id->t_symbols[1] = res;
+                               if (sc != NULL && sc->sc_isconsole) {
+                                       if (res & 0xff)
+                                               ws_check_magic((res & 0xff), 
ws_cnm_state);
+                                       if ((res >> 8) & 0xff)
+                                               ws_check_magic(((res >> 8) & 
0xff), ws_cnm_state);
+                                       if (KS_Escape & 0xff)
+                                               ws_check_magic((KS_Escape & 
0xff), ws_cnm_state);
+                                       if ((KS_Escape >> 8) & 0xff)
+                                               ws_check_magic(((KS_Escape >> 
8) & 0xff), ws_cnm_state);
+                               }
+
                                return (2);
                        } else
                                res |= 0x80;
                }
+       
        }
 
        id->t_symbols[0] = res;
+
+       if (sc != NULL && sc->sc_isconsole) {
+               if (res & 0xff)
+                       ws_check_magic((res & 0xff), ws_cnm_state);
+               if ((res >> 8) & 0xff)
+                       ws_check_magic(((res >> 8) & 0xff), ws_cnm_state);
+       }
+
        return (1);
 }

It works - but it definately needs reworking.

NB: This patch is my own work, which I submit under the NetBSD license.

I hope others find this useful.

Regards,

Nat.