Allow leading ``!'' characters in authkeys and chat scripts to

be doubled up to mean a single literaly ``!''.

usr.sbin/ppp/README.changes

@@ -102,3 +102,5 @@ o It is now only necessary to escape the `-' character in chat scripts twice.
   See the example files for details.
 o Environment variables and ~ are expanded on in commands
 o ``nat pptp'' is no longer necessary as this is now done transparently
+o The ``!'' at the start of chat scripts and authkey can be made literal
+  (rather than meaning execute) by doubling it to ``!!''.

usr.sbin/ppp/chap.c

@@ -682,12 +682,13 @@ chap_Input(struct bundle *bundle, struct link *l, struct mbuf *bp)
 
     switch (chap->auth.in.hdr.code) {
       case CHAP_CHALLENGE:
-        if (*bundle->cfg.auth.key == '!')
+        if (*bundle->cfg.auth.key == '!' && bundle->cfg.auth.key[1] != '!')
           chap_StartChild(chap, bundle->cfg.auth.key + 1,
                           bundle->cfg.auth.name);
         else
-          chap_Respond(chap, bundle->cfg.auth.name,
-                       bundle->cfg.auth.key, p->link.lcp.his_authtype
+          chap_Respond(chap, bundle->cfg.auth.name, bundle->cfg.auth.key +
+                       (*bundle->cfg.auth.key == '!' ? 1 : 0),
+                       p->link.lcp.his_authtype
 #ifdef HAVE_DES
                        , lanman
 #endif

usr.sbin/ppp/chat.c

@@ -213,7 +213,8 @@ chat_UpdateSet(struct fdescriptor *d, fd_set *r, fd_set *w, fd_set *e, int *n)
        * portion of that sequence.
        */
 
-      needcr = c->state == CHAT_SEND && *c->argptr != '!';
+      needcr = c->state == CHAT_SEND &&
+               (*c->argptr != '!' || c->argptr[1] == '!');
 
       /* We leave room for a potential HDLC header in the target string */
       ExpandString(c, c->argptr, c->exp + 2, sizeof c->exp - 2, needcr);
@@ -254,8 +255,8 @@ chat_UpdateSet(struct fdescriptor *d, fd_set *r, fd_set *w, fd_set *e, int *n)
       else if (c->nargptr == NULL && !strcmp(c->exp+2, "TIMEOUT"))
         gottimeout = 1;
       else {
-        if (c->exp[2] == '!')
-          ExecStr(c->physical, c->exp + 3, c->exp + 2, sizeof c->exp - 2);
+        if (c->exp[2] == '!' && c->exp[3] != '!')
+          ExecStr(c->physical, c->exp + 3, c->exp + 3, sizeof c->exp - 3);
 
         if (c->exp[2] == '\0') {
           /* Empty string, reparse (this may be better as a `goto start') */
@@ -279,7 +280,7 @@ chat_UpdateSet(struct fdescriptor *d, fd_set *r, fd_set *w, fd_set *e, int *n)
     }
 
     /* set c->argptr to point in the right place */
-    c->argptr = c->exp + 2;
+    c->argptr = c->exp + (c->exp[2] == '!' ? 3 : 2);
     c->arglen = strlen(c->argptr);
 
     if (c->state == CHAT_EXPECT) {

usr.sbin/ppp/ppp.8

@@ -3782,7 +3782,13 @@ and
 .Dq authkey
 values.
 .Pp
-Ignoring the
+If the
+.Dq \&!
+is doubled up
+.Pq to Dq \&!! ,
+it is treated as a single literal
+.Dq \&! ,
+otherwise, ignoring the
 .Dq \&! ,
 .Ar value
 is parsed as a program to execute in the same was as the
@@ -4289,6 +4295,10 @@ It is also possible to execute external commands from the chat script.
 To do this, the first character of the expect or send string is an
 exclamation mark
 .Pq Dq \&! .
+If a literal exclaimation mark is required, double it up to
+.Dq \&!!
+and it will be treated as a single literal
+.Dq \&! .
 When the command is executed, standard input and standard output are
 directed to the open device (see the
 .Dq set device

usr.sbin/ppp/ppp.8.m4

@@ -3782,7 +3782,13 @@ and
 .Dq authkey
 values.
 .Pp
-Ignoring the
+If the
+.Dq \&!
+is doubled up
+.Pq to Dq \&!! ,
+it is treated as a single literal
+.Dq \&! ,
+otherwise, ignoring the
 .Dq \&! ,
 .Ar value
 is parsed as a program to execute in the same was as the
@@ -4289,6 +4295,10 @@ It is also possible to execute external commands from the chat script.
 To do this, the first character of the expect or send string is an
 exclamation mark
 .Pq Dq \&! .
+If a literal exclaimation mark is required, double it up to
+.Dq \&!!
+and it will be treated as a single literal
+.Dq \&! .
 When the command is executed, standard input and standard output are
 directed to the open device (see the
 .Dq set device