Improved tun error reporting

src/exception.cpp

@@ -30,6 +30,11 @@ Exception::Exception(const char *msg)
     this->msg = msg;
 }
 
+Exception::Exception(const string msg)
+{
+    this->msg = msg;
+}
+
 Exception::Exception(const char *msg, bool appendSystemError)
 {
     if (appendSystemError)

src/exception.h

@@ -23,8 +23,9 @@ class Exception
 {
 public:
     Exception(const char *msg);
+    Exception(const std::string msg);
     Exception(const char *msg, bool appendSystemError);
-    
+
     const char *errorMessage() const { return msg.c_str(); }
 protected:
     std::string msg;

src/tun.cpp

@@ -28,7 +28,6 @@
 #include <syslog.h>
 #include <stdlib.h>
 #include <string.h>
-#include <errno.h>
 #include <stdio.h>
 
 typedef ip IpHeader;
@@ -49,7 +48,7 @@ Tun::Tun(const char *device, int mtu)
 
     fd = tun_open(this->device);
     if (fd == -1)
-        throw Exception("could not create tunnel device");
+        throw Exception(string("could not create tunnel device: ") + tun_last_error());
 
     char cmdline[512];
     snprintf(cmdline, sizeof(cmdline), "/sbin/ifconfig %s mtu %u", this->device, mtu);
@@ -90,14 +89,14 @@ void Tun::setIp(uint32_t ip, uint32_t destIp, bool includeSubnet)
 void Tun::write(const char *buffer, int length)
 {
     if (tun_write(fd, (char *)buffer, length) == -1)
-        syslog(LOG_ERR, "error writing %d bytes to tun: %s", length, strerror(errno));
+        syslog(LOG_ERR, "error writing %d bytes to tun: %s", length, tun_last_error());
 }
 
 int Tun::read(char *buffer)
 {
     int length = tun_read(fd, buffer, mtu);
     if (length == -1)
-        syslog(LOG_ERR, "error reading from tun: %s", strerror(errno));
+        syslog(LOG_ERR, "error reading from tun: %s", tun_last_error());
     return length;
 }
 

src/tun_dev.h

@@ -24,4 +24,5 @@ extern "C"
     int tun_close(int fd, char *dev);
     int tun_write(int fd, char *buf, int len);
     int tun_read(int fd, char *buf, int len);
+    const char *tun_last_error();
 }

src/tun_dev_darwin_emu.c

@@ -1,19 +1,20 @@
-/*  
- VTun - Virtual Tunnel over TCP/IP network.
- 
- Copyright (C) 1998-2000  Maxim Krasnyansky <max_mk@yahoo.com>
- 
- VTun has been derived from VPPP package by Maxim Krasnyansky. 
- 
- This program is free software; you can redistribute it and/or modify
- it under the terms of the GNU General Public License as published by
- the Free Software Foundation; either version 2 of the License, or
- (at your option) any later version.
- 
- This program is distributed in the hope that it will be useful,
- but WITHOUT ANY WARRANTY; without even the implied warranty of
- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- GNU General Public License for more details.
+/*
+ *  Hans - IP over ICMP
+ *  Copyright (C) 2009 Friedrich Schöller <hans@schoeller.se>
+ *  
+ *  This program is free software: you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation, either version 3 of the License, or
+ *  (at your option) any later version.
+ *  
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *  
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *  
  */
 
 #include "tunemu.h"
@@ -22,10 +23,7 @@
 
 int tun_open(char *dev)
 {
-    int fd = tunemu_open(dev);
-    if (fd < 0)
-        syslog(LOG_ERR, tunemu_error);
-    return fd;
+    return tunemu_open(dev);
 }
 
 int tun_close(int fd, char *dev)
@@ -42,3 +40,8 @@ int tun_read(int fd, char *buf, int len)
 {
     return tunemu_read(fd, buf, len);
 }
+
+const char *tun_last_error()
+{
+    return tunemu_error;
+}

src/tun_dev_freebsd.c

@@ -28,6 +28,7 @@
 #include <stdio.h>
 #include <string.h>
 #include <syslog.h>
+#include <errno.h>
 
 #include <sys/ioctl.h>
 #include <net/if_tun.h>
@@ -81,3 +82,8 @@ int tun_read(int fd, char *buf, int len)
 {
     return read(fd, buf, len);
 }
+
+const char *tun_last_error()
+{
+    return strerror(errno);
+}

src/tun_dev_generic.c

@@ -28,6 +28,7 @@
 #include <stdio.h>
 #include <string.h>
 #include <syslog.h>
+#include <errno.h>
 
 /* #include "vtun.h"
 #include "lib.h" */
@@ -72,3 +73,8 @@ int tun_read(int fd, char *buf, int len)
 {
     return read(fd, buf, len);
 }
+
+const char *tun_last_error()
+{
+    return strerror(errno);
+}

src/tun_dev_linux.c

@@ -130,3 +130,8 @@ int tap_write(int fd, char *buf, int len) { return write(fd, buf, len); }
 
 int tun_read(int fd, char *buf, int len) { return read(fd, buf, len); }
 int tap_read(int fd, char *buf, int len) { return read(fd, buf, len); }
+
+const char *tun_last_error()
+{
+    return strerror(errno);
+}

src/tun_dev_openbsd.c

@@ -28,6 +28,7 @@
 #include <stdio.h>
 #include <string.h>
 #include <syslog.h>
+#include <errno.h>
 
 #include <sys/types.h>
 #include <sys/uio.h>
@@ -98,3 +99,8 @@ int tun_read(int fd, char *buf, int len)
     else
        return rlen;
 }
+
+const char *tun_last_error()
+{
+    return strerror(errno);
+}

src/tun_dev_svr4.c

@@ -175,3 +175,8 @@ int tun_read(int fd, char *buf, int len)
     sbuf.buf = buf;      
     return getmsg(fd, NULL, &sbuf, &f) >=0 ? sbuf.len : -1;
 }
+
+const char *tun_last_error()
+{
+    return strerror(errno);
+}