From 72c0b1a2991fe70301be3056c82d3c46509bc615 Mon Sep 17 00:00:00 2001
From: Kai Germaschewski <kai@thphy.uni-duesseldorf.de>
Date: Sat, 29 Apr 2000 08:57:24 +0000
Subject: [PATCH] Fixed bug in ipppd: MPdiscr is now random

added option deldefaultroute
---
 ipppd/ipppd.h      |  1 +
 ipppd/ipppd.man.in |  5 +++++
 ipppd/lcp.c        |  1 +
 ipppd/main.c       | 10 +++++-----
 ipppd/options.c    |  9 +++++++++
 ipppd/sys-linux.c  | 36 +++++++++++++++++++++++++-----------
 6 files changed, 46 insertions(+), 16 deletions(-)

diff --git a/ipppd/ipppd.h b/ipppd/ipppd.h
index 6b6c139d..ee27c8a2 100644
--- a/ipppd/ipppd.h
+++ b/ipppd/ipppd.h
@@ -179,6 +179,7 @@ extern char sys_rcsid[];
 
 extern int maxconnect;
 extern int      usefirstip,useifip,useifmtu;
+extern int      deldefaultroute;/* delete default gw, if it exists */
 extern int      numdev;		/* number of handled devices */
 extern int	debug;		/* Debug flag */
 extern int	kdebugflag;	/* Tell kernel to print debug messages */
diff --git a/ipppd/ipppd.man.in b/ipppd/ipppd.man.in
index 9cdb9982..693e41f8 100644
--- a/ipppd/ipppd.man.in
+++ b/ipppd/ipppd.man.in
@@ -163,6 +163,11 @@ Disable the \fBdefaultroute\fR option.  The system administrator who
 wishes to prevent users from creating default routes with \fIipppd\fR
 can do so by placing this option in the /etc/ppp/ioptions file.
 .TP
+.B deldefaultroute
+Replace default route if it already exists. Together with the option 
+\fBdefaultroute\fR, this will replace any existing default route by a new
+one through this ipppd's interface when it comes up.
+.TP 
 .B -detach
 Don't fork to become a background process (otherwise
 .I ipppd
diff --git a/ipppd/lcp.c b/ipppd/lcp.c
index a023f3e9..028afb6d 100644
--- a/ipppd/lcp.c
+++ b/ipppd/lcp.c
@@ -190,6 +190,7 @@ static void lcp_init(int unit)
     {
       *(u_int32_t *) (&our_discr_addr[0]) = magic();
       *(u_int32_t *) (&our_discr_addr[4]) = magic();
+     
       first_call = 0;
     }
 
diff --git a/ipppd/main.c b/ipppd/main.c
index afd1f474..3560f9b4 100644
--- a/ipppd/main.c
+++ b/ipppd/main.c
@@ -165,6 +165,11 @@ int main(int argc,char **argv)
 		exit(1);
 	}
 
+	/*
+	 * Initialize magic number package.
+	 */
+	magic_init();
+
 	for(i=0;i<NUM_PPP;i++) {
 		lns[i].openfails = 0;
 		lns[i].initfdflags = -1;
@@ -246,11 +251,6 @@ int main(int argc,char **argv)
       syslog(LOG_NOTICE,devstr);
     }
 
-    /*
-     * Initialize magic number package.
-     */
-    magic_init();
-
     /*
      * Detach ourselves from the terminal, if required,
      * and identify who is running us.
diff --git a/ipppd/options.c b/ipppd/options.c
index b392b19f..fbb39a38 100644
--- a/ipppd/options.c
+++ b/ipppd/options.c
@@ -114,6 +114,7 @@ int	disable_defaultip = 0;	/* Don't use hostname for default IP adrs */
 char *ipparam = NULL;	/* Extra parameter for ip up/down scripts */
 int	cryptpap;		/* Passwords in pap-secrets are encrypted */
 int useifip=0;		/* try to get IP addresses from interface */
+int deldefaultroute=0;  /* delete default route, if it exists */
 int usefirstip=0;
 int useifmtu=0;		/* get MTU value from network device */
 
@@ -247,6 +248,7 @@ static int setwinsaddr __P((int,char **));
 static int setgetwinsaddr __P((int,char **));
 static int resetipxproto __P((int));
 static int setuseifip __P((int));
+static int setdeldefaultroute __P((int));
 static int setusefirstip __P((int));
 static int setmp __P((int));
 static int setpwlog __P((int));
@@ -413,6 +415,7 @@ static struct cmd {
     {"-ipx",   0, resetipxproto},      /* Disable IPXCP (and IPX) */
 
     {"useifip",0,setuseifip},            /* call setifip() for IP addrs */
+    {"deldefaultroute",0, setdeldefaultroute}, /* call setdeldefaultroute for defaultroute */
     {"usefirstip",0,setusefirstip}, /* use first IP from auth file for remote */
     {"+mp",0,setmp},
     {"+pwlog",0,setpwlog},
@@ -1316,6 +1319,12 @@ static int setuseifip(int slot)
   return 1;
 }
 
+static int setdeldefaultroute(int slot)
+{
+  deldefaultroute = 1;
+  return 1;
+}
+
 static int setifmtu(int slot)
 {
   useifmtu = 1;
diff --git a/ipppd/sys-linux.c b/ipppd/sys-linux.c
index cae7b230..c64aac3e 100644
--- a/ipppd/sys-linux.c
+++ b/ipppd/sys-linux.c
@@ -35,6 +35,7 @@ char sys_rcsid[] = "$Id$";
 #include <sys/stat.h>
 #include <sys/file.h>
 #include <sys/utsname.h>
+#include <sys/sysmacros.h>
 
 #include <stdio.h>
 #include <stdlib.h>
@@ -92,6 +93,10 @@ static void decode_version (char *buf, int *version,
 int sockfd;			/* socket for doing interface ioctls */
 
 static char *lock_file;
+static int kernel_version;
+
+#define SIN_ADDR(x)     (((struct sockaddr_in *) (&(x)))->sin_addr.s_addr)
+#define KVERSION(j,n,p) ((j)*1000000 + (n)*1000 + (p))
 
 #define MAX_IFS		4096
 
@@ -857,26 +862,35 @@ static int defaultroute_exists (void)
     int    result = 0;
 
     if (!open_route_table())
-      {
-        return 0;
-      }
+      return 0;
 
     while (read_route_table(&rt) != 0)
       {
+        if (kernel_version > KVERSION(2,1,0) && SIN_ADDR(rt.rt_genmask) != 0)
+	  continue;
+	
         if ((rt.rt_flags & RTF_UP) == 0)
-	  {
-	    continue;
-	  }
+          continue;
 
         if (((struct sockaddr_in *) &rt.rt_dst)->sin_addr.s_addr == 0L)
 	  {
             struct in_addr ina;
             ina.s_addr = ((struct sockaddr_in *) &rt.rt_gateway)->sin_addr.s_addr;
-	    syslog (LOG_ERR,
-		    "ppp not replacing existing default route to %s[%s]",
-		    rt.rt_dev, inet_ntoa (ina) );
-	    result = 1;
-	    break;
+	    if (!deldefaultroute)
+	      {
+	        syslog (LOG_ERR,
+		      "ppp not replacing existing default route to %s[%s]",
+		       rt.rt_dev, inet_ntoa (ina) );
+	        result = 1;
+	        break;
+	      }
+	    else
+	      {
+	        SET_SA_FAMILY (rt.rt_dst,     AF_INET);
+		SET_SA_FAMILY (rt.rt_gateway, AF_INET);
+		rt.rt_flags = RTF_UP | RTF_GATEWAY;
+		ioctl(sockfd, SIOCDELRT, &rt);
+	      }
 	  }
       }