Add "set loopback on|off", defaulting to "on".

This tells ppp to loopback packets addressed to
the ppp interface IP coming *from* the tun
device.

This means that you can ping the tun interface IP
from inside :-)

6 files changed, 88 insertions, 8 deletions

diff --git a/usr.sbin/ppp/command.c b/usr.sbin/ppp/command.c
index 27237fa..c2eaf7a 100644
--- a/usr.sbin/ppp/command.c
+++ b/usr.sbin/ppp/command.c
@@ -17,7 +17,7 @@
  * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
  * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
  *
- * $Id: command.c,v 1.71 1997/08/20 23:47:41 brian Exp $
+ * $Id: command.c,v 1.72 1997/08/21 16:18:07 brian Exp $
  *
  */
 #include <sys/types.h>
@@ -185,6 +185,17 @@ char **argv;
 }
 
 static int
+SetLoopback(struct cmdtab *cmdlist, int argc, char **argv)
+{
+  if (argc == 1)
+    if (!strcasecmp(*argv, "on"))
+      VarLoopback = 1;
+    else if (!strcasecmp(*argv, "off"))
+      VarLoopback = 0;
+  return -1;
+}
+
+static int
 BgShellCommand(struct cmdtab *cmdlist, int argc, char **argv)
 {
   if (argc == 0)
@@ -368,6 +379,15 @@ extern int ShowModemStatus();
 extern int ReportHdlcStatus();
 extern int ShowMemMap();
 
+static int
+ShowLoopback()
+{
+  if (VarTerm)
+    fprintf(VarTerm, "Local loopback is %s\n", VarLoopback ? "on" : "off");
+
+  return 0;
+}
+
 static int ShowLogLevel()
 {
   int i;
@@ -554,6 +574,8 @@ struct cmdtab const ShowCommands[] = {
 	"Show IPCP status", "show ipcp"},
   { "lcp",      NULL,     ReportLcpStatus,	LOCAL_AUTH,
 	"Show LCP status", "show lcp"},
+  { "loopback",	NULL,	  ShowLoopback,	LOCAL_AUTH,
+	"Show current loopback setting", "show loopback"},
   { "log",	NULL,	  ShowLogLevel,	LOCAL_AUTH,
 	"Show current log level", "show log"},
   { "mem",      NULL,     ShowMemMap,		LOCAL_AUTH,
@@ -1352,6 +1374,8 @@ struct cmdtab const SetCommands[] = {
 	"Set destination address", "set ifaddr [src-addr [dst-addr [netmask [trg-addr]]]]"},
   { "ifilter",  NULL,     SetIfilter, 		LOCAL_AUTH,
 	"Set input filter", "set ifilter ..."},
+  { "loopback", NULL,	  SetLoopback,		LOCAL_AUTH,
+	"Set loopback facility", "set loopback on|off"},
   { "log",    NULL,	  SetLogLevel,	LOCAL_AUTH,
 	"Set log level", "set log [+|-]value..."},
   { "login",    NULL,     SetVariable,		LOCAL_AUTH,
diff --git a/usr.sbin/ppp/main.c b/usr.sbin/ppp/main.c
index 75ad657..694e6f8 100644
--- a/usr.sbin/ppp/main.c
+++ b/usr.sbin/ppp/main.c
@@ -17,7 +17,7 @@
  * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
  * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
  *
- * $Id: main.c,v 1.68 1997/06/29 13:54:31 brian Exp $
+ * $Id: main.c,v 1.69 1997/07/01 21:31:23 brian Exp $
  *
  *	TODO:
  *		o Add commands for traffic summary, version display, etc.
@@ -51,6 +51,7 @@
 #include "ip.h"
 #include "sig.h"
 #include "server.h"
+#include "lcpproto.h"
 
 #define LAUTH_M1 "Warning: No password entry for this host in ppp.secret\n"
 #define LAUTH_M2 "Warning: Manipulation is allowed by anyone\n"
@@ -1013,6 +1014,27 @@ DoLoop()
         LogPrintf(LogERROR, "read from tun: %s", strerror(errno));
 	continue;
       }
+
+      if (((struct ip *)rbuff)->ip_dst.s_addr == IpcpInfo.want_ipaddr.s_addr) {
+	/* we've been asked to send something addressed *to* us :( */
+	if (VarLoopback) {
+	  pri = PacketCheck(rbuff, n, FL_IN);
+	  if (pri >= 0) {
+	    struct mbuf *bp;
+	    if (mode & MODE_ALIAS) {
+	      VarPacketAliasIn(rbuff, sizeof rbuff);
+	      n = ntohs(((struct ip *)rbuff)->ip_len);
+	    }
+	    bp = mballoc(n, MB_IPIN);
+	    bcopy(rbuff, MBUF_CTOP(bp), n);
+	    IpInput(bp);
+	    LogPrintf(LogDEBUG, "Looped back packet addressed to myself\n");
+	  }
+	  continue;
+        } else
+	  LogPrintf(LogDEBUG, "Oops - forwarding packet addressed to myself\n");
+      }
+
       /*
        *  Process on-demand dialup. Output packets are queued within tunnel
        *  device until IPCP is opened.
diff --git a/usr.sbin/ppp/ppp.8 b/usr.sbin/ppp/ppp.8
index f88e905..60e9384 100644
--- a/usr.sbin/ppp/ppp.8
+++ b/usr.sbin/ppp/ppp.8
@@ -1,4 +1,4 @@
-.\" $Id: ppp.8,v 1.53 1997/08/19 11:27:00 danny Exp $
+.\" $Id: ppp.8,v 1.54 1997/08/20 23:47:51 brian Exp $
 .Dd 20 September 1995
 .Os FreeBSD
 .Dt PPP 8
@@ -1644,6 +1644,19 @@ in the initial IPCP negotiation.  However, only an address in the
 .Dq myaddr
 range will be accepted.
 
+.It set loopback on|off
+When set to
+.Dq on
+(the default),
+.Nm
+will automatically loop back packets being sent
+out with a destination address equal to that of the ppp interface.
+If set to
+.Dq off ,
+.Nm
+will send the packet, probably resulting in an ICMP redirect from
+the other end.
+
 .It set log [+|-]value...
 This command allows the adjustment of the current log level.  Please
 refer to the Logging Facility section for further details.
@@ -1822,6 +1835,9 @@ Show the current IPCP statistics.
 .It show lcp
 Show the current LCP statistics.
 
+.It show loopback
+Show the current loopback status.
+
 .It show log
 Show the current log values.
 
diff --git a/usr.sbin/ppp/ppp.8.m4 b/usr.sbin/ppp/ppp.8.m4
index f88e905..60e9384 100644
--- a/usr.sbin/ppp/ppp.8.m4
+++ b/usr.sbin/ppp/ppp.8.m4
@@ -1,4 +1,4 @@
-.\" $Id: ppp.8,v 1.53 1997/08/19 11:27:00 danny Exp $
+.\" $Id: ppp.8,v 1.54 1997/08/20 23:47:51 brian Exp $
 .Dd 20 September 1995
 .Os FreeBSD
 .Dt PPP 8
@@ -1644,6 +1644,19 @@ in the initial IPCP negotiation.  However, only an address in the
 .Dq myaddr
 range will be accepted.
 
+.It set loopback on|off
+When set to
+.Dq on
+(the default),
+.Nm
+will automatically loop back packets being sent
+out with a destination address equal to that of the ppp interface.
+If set to
+.Dq off ,
+.Nm
+will send the packet, probably resulting in an ICMP redirect from
+the other end.
+
 .It set log [+|-]value...
 This command allows the adjustment of the current log level.  Please
 refer to the Logging Facility section for further details.
@@ -1822,6 +1835,9 @@ Show the current IPCP statistics.
 .It show lcp
 Show the current LCP statistics.
 
+.It show loopback
+Show the current loopback status.
+
 .It show log
 Show the current log values.
 
diff --git a/usr.sbin/ppp/vars.c b/usr.sbin/ppp/vars.c
index 4b0b375..95434fd 100644
--- a/usr.sbin/ppp/vars.c
+++ b/usr.sbin/ppp/vars.c
@@ -17,7 +17,7 @@
  * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
  * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
  *
- * $Id: vars.c,v 1.21 1997/08/17 20:45:49 brian Exp $
+ * $Id: vars.c,v 1.22 1997/08/20 23:47:52 brian Exp $
  *
  */
 #include "fsm.h"
@@ -30,7 +30,7 @@
 #include "defs.h"
 
 char VarVersion[] = "PPP Version 1.00";
-char VarLocalVersion[] = "$Date: 1997/08/17 20:45:49 $";
+char VarLocalVersion[] = "$Date: 1997/08/20 23:47:52 $";
 
 /*
  * Order of conf option is important. See vars.h.
@@ -52,7 +52,7 @@ struct confdesc pppConfs[] = {
 struct pppvars pppVars = {
   DEF_MRU, DEF_MTU, 0, MODEM_SPEED, CS8, MODEM_CTSRTS, 180, 30, 3,
   RECONNECT_TIMER, RECONNECT_TRIES, REDIAL_PERIOD,
-  NEXT_REDIAL_PERIOD, 1, MODEM_DEV, BASE_MODEM_DEV,
+  NEXT_REDIAL_PERIOD, 1, 1, MODEM_DEV, BASE_MODEM_DEV,
   OPEN_ACTIVE, LOCAL_NO_AUTH,0
 };
 
diff --git a/usr.sbin/ppp/vars.h b/usr.sbin/ppp/vars.h
index ae12495..4583a2a 100644
--- a/usr.sbin/ppp/vars.h
+++ b/usr.sbin/ppp/vars.h
@@ -15,7 +15,7 @@
  * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
  * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
  *
- * $Id: vars.h,v 1.22 1997/08/17 20:45:50 brian Exp $
+ * $Id: vars.h,v 1.23 1997/08/20 23:47:53 brian Exp $
  *
  *	TODO:
  */
@@ -68,6 +68,7 @@ struct pppvars {
   int    redial_timeout;	/* Redial timeout value */
   int    redial_next_timeout;	/* Redial next timeout value */
   int    dial_tries;		/* Dial attempts before giving up, 0 == inf */
+  int    loopback;		/* Turn around packets addressed to me */
   char   modem_dev[40];		/* Name of device / host:port */
   char  *base_modem_dev;        /* Pointer to base of modem_dev */
   int	 open_mode;		/* LCP open mode */
@@ -118,6 +119,7 @@ struct pppvars {
 #define VarRedialTimeout pppVars.redial_timeout
 #define VarRedialNextTimeout pppVars.redial_next_timeout
 #define VarDialTries	pppVars.dial_tries
+#define VarLoopback	pppVars.loopback
 #define VarTerm		pppVars.termfp
 
 #define VarAliasHandlers	   pppVars.handler