Presume that Linux is always IPv6 capable at build time

These days it is highly unlikely that OpenVPN will be built in a non-IPv6 capable Linux environment. So remove compile-time related macros identifying that.

This also solves an issue which was introduced in commit 51bd56f46f55177cf0f8b where HAVE_TUN_PI and HAVE_IPHDR is no longer detected. As these macros where only used to detect if IPv6 support was available on Linux, it makes no sense looking for them any more.

These days it is highly unlikely that OpenVPN will be built in a non-IPv6 capable Linux environment.

This also solves an issue which was introduced in commit 51bd56f46f55177cf0f8b where HAVE_TUN_PI and HAVE_IPHDR is no longer detected.  As these macros where only used to detect if IPv6 support was available on Linux, it makes no sense looking for them any more.

Gert appears to be happy, so I'm happy, but I don't quite understand what you're saying here. What part broke? HAVE_TUN_PI and HAVE_IPHDR aren't always detected although they should be? Or the failed detection affects non-Linux systems? Something else? Just curious ...

These days it is highly unlikely that OpenVPN will be built in a non-IPv6 capable Linux environment.  So remove compile-time related macros identifying that.

This also solves an issue which was introduced in commit 51bd56f46f55177cf0f8b where HAVE_TUN_PI and HAVE_IPHDR is no longer detected.  As these macros where only used to detect if IPv6 support was available on Linux, it makes no sense looking for them any more.

Signed-off-by David Sommerseth <[email protected]...>

---
 configure.ac      |   13 -------------
 src/openvpn/tun.c |   19 -------------------

 2 files changed, 0 insertions(+), 32 deletions(-)

configure.ac +0 -0

index e962323..4286866 100644
@@ -404,7 +404,6 @@ AC_CHECK_HEADERS(
        ,

       [[${SOCKET_INCLUDES}]]
 )
-
 AC_CHECK_TYPES(
       [in_addr_t],
       ,

configure.ac +0 -0

@@ -412,18 +411,6 @@ AC_CHECK_TYPES(

       [[${SOCKET_INCLUDES}]]
 )
 AC_CHECK_TYPE(
-       [struct tun_pi],
-       [AC_DEFINE(HAVE_TUN_PI, 1, [struct tun_pi needed for IPv6 support])],
-       ,
-       [[${SOCKET_INCLUDES}]]

configure.ac +0 -8

-)
-AC_CHECK_TYPE(
-       [struct iphdr],
-       [AC_DEFINE(HAVE_IPHDR, 1, [struct iphdr needed for IPv6 support])],
-       ,
-       [[${SOCKET_INCLUDES}]]
-)
-AC_CHECK_TYPE(

       [struct sock_extended_err],
       [AC_DEFINE(HAVE_SOCK_EXTENDED_ERR, 1, [struct sock_extended_err needed for extended socket error support])], ,

src/openvpn/tun.c +0 -8

index b99071c..63e6f77 100644
@@ -1373,14 +1373,6 @@ close_tun_generic (struct tuntap *tt)
  #error header file linux/sockios.h required
  #endif
 
-#if defined(HAVE_TUN_PI) && defined(HAVE_IPHDR) && defined(HAVE_IOVEC) && defined(ETH_P_IPV6) && defined(ETH_P_IP) && defined(HAVE_READV) && defined(HAVE_WRITEV)
-#define LINUX_IPV6 1
-/* #warning IPv6 ON */
-#else
-#define LINUX_IPV6 0
-/* #warning IPv6 OFF */
-#endif
-
  #if !PEDANTIC
 

 void

src/openvpn/tun.c +0 -7

@@ -1388,13 +1380,6 @@ open_tun (const char *dev, const char *dev_type, const char *dev_node, struct tu
  {
   struct ifreq ifr;
 
-  /* warn if a very old linux version is used & --tun-ipv6 set
-   */
-#if LINUX_IPV6 == 0
-  if ( tt->ipv6 )
-    msg (M_WARN, "NOTE: explicit support for IPv6 tun devices is not provided for this OS");
-#endif
-
   /*
    * We handle --dev null specially, we do not open /dev/null for this.
    */

@@ -1623,7 +1608,6 @@ close_tun (struct tuntap *tt)

 int
 write_tun (struct tuntap* tt, uint8_t *buf, int len) {
-#if LINUX_IPV6
  if (tt->ipv6)
    {
      struct tun_pi pi;

src/openvpn/tun.c +0 -0

@@ -1649,14 +1633,12 @@ write_tun (struct tuntap* tt, uint8_t *buf, int len)
       return(ret - sizeof(pi));
     }

  else
-#endif
    return write (tt->fd, buf, len);
 }

 int
 read_tun (struct tuntap* tt, uint8_t *buf, int len) {
-#if LINUX_IPV6
  if (tt->ipv6)
    {
      struct iovec vect[2];

src/openvpn/tun.c +0 -0

@@ -1672,7 +1654,6 @@ read_tun (struct tuntap* tt, uint8_t *buf, int len)
       return(ret - sizeof(pi));
     }

  else
-#endif
    return read (tt->fd, buf, len);
 }

--
1.7.4.4

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I plan to add --enable-ipv6/--disable-ipv6 to explicit support ipv6.

Hi,

Quoted 2 lines · Alon Bar-Lev

I plan to add --enable-ipv6/--disable-ipv6 to explicit support ipv6.

NAK.

We considered this, and this will add a shitload of #ifdefs which will make maintenance of the code a lot harder.

(We actually *removed* all the #ifdefs of JJO's IPv6 transport code, because it really hurt)

We're in the year 2012, there are no operating systems without IPv6 support anymore, and it does not make sense to have a VPN implementation that has no IPv6 support.

Quoted 14 lines · Gert Doering

Hi,

Quoted 2 lines · Alon Bar-Lev

I plan to add --enable-ipv6/--disable-ipv6 to explicit support ipv6.

NAK.

We considered this, and this will add a shitload of #ifdefs which will make maintenance of the code a lot harder.

(We actually *removed* all the #ifdefs of JJO's IPv6 transport code, because it really hurt)

Quoted 3 lines

We're in the year 2012, there are no operating systems without IPv6 support anymore, and it does not make sense to have a VPN implementation that has no IPv6 support.

Just for the record, I completely agree with Gert here.  Actually we should focus on getting OpenVPN work better in IPv6-only environments
- - but that's probably something for the 2.4 cycle.

Quoted 15 lines · David Sommerseth

Quoted 14 lines · Gert Doering

Hi,

Quoted 2 lines · Alon Bar-Lev

I plan to add --enable-ipv6/--disable-ipv6 to explicit support ipv6.

NAK.

We considered this, and this will add a shitload of #ifdefs which will make maintenance of the code a lot harder.

(We actually *removed* all the #ifdefs of JJO's IPv6 transport code, because it really hurt)

Quoted 8 lines

Quoted 3 lines

We're in the year 2012, there are no operating systems without IPv6 support anymore, and it does not make sense to have a VPN implementation that has no IPv6 support.

Just for the record, I completely agree with Gert here.  Actually we should focus on getting OpenVPN work better in IPv6-only environments
- - but that's probably something for the 2.4 cycle.

At embedded system and several distros like Gentoo, the ipv6 should be made enable/disabled, just like any other project.
It is the same #ifdef as we already have these in code. Even in 2012 kernels can be compiled without ipv6.

Alon.

At embedded system and several distros like Gentoo, the ipv6 should be made enable/disabled, just like any other project.
It is the same #ifdef as we already have these in code. Even in 2012 kernels can be compiled without ipv6.

Hi Alon,

2012/4/26 Alon Bar-Lev <[email protected]...>:

Quoted 4 lines

At embedded system and several distros like Gentoo, the ipv6 should be made enable/disabled, just like any other project.
It is the same #ifdef as we already have these in code. Even in 2012 kernels can be compiled without ipv6.

If embedded systems really need to save space, maybe we should make IPv4 optional instead? :)

At embedded system and several distros like Gentoo, the ipv6 should be made enable/disabled, just like any other project.
It is the same #ifdef as we already have these in code. Even in 2012 kernels can be compiled without ipv6.

Hi,

Quoted 4 lines · Alon Bar-Lev

At embedded system and several distros like Gentoo, the ipv6 should be made enable/disabled, just like any other project.
It is the same #ifdef as we already have these in code. Even in 2012 kernels can be compiled without ipv6.

Enabling/disabling IPv6 for "just some piece of random code that can open up network sockets" is easy, and usually not even worth the extra lines of code ("just pass different options to getaddrinfo() and/or bind()").

Given the nature of OpenVPN, and that almost everything in the code (except for the crypto stuff) is related to IP packets or IP addresses, it's not that straightforward here.

Adding IPv6 to the OpenVPN code base touched well over 100 different places of the code, and to really make it optional (to get the space saving worth for an embedded system) you'd have to have #ifdef's at all these places, in the config data structures, and so on - this is lots of work, especially maintaining both code paths and testing all this, with dubious benefits.  As I said, we got bitten by JJO's decision to make IPv6 transport conditonal, and decided to get *rid* of those #ifdefs for the sake of "less code paths, less maintenance effort".

I'm not sure you can find packages that have had working IPv6 support, and then decided to make it conditional afterwards.  Usually IPv6 was added at some point, and it was added conditionalized, because that package can also be compiled on older systems without IPv6 - since we have the luxury of not supporting anything that has no tun/tap interface, we have the same luxury of not having to bother with anything that has no IPv6.  (Even if you compile the Linux kernel and glibc without IPv6, the API stuff - getaddrinfo(), inet_ntop(), etc., will still be there, because they are IP version agnostic - they will fail if you actually try to *use* them for IPv6, but you can compile and run the same applications just fine).

Right, the ipv6 was added indeed differently, without this conditionals.

Because of this I did not perform this task as part of the major build cleanup, and left this for the next phase.
Most of the lowlevel network code already has #ifdefs, I will try my best to find a way to do the conditional without much changes.

Hi,

Quoted 1 line · Alon Bar-Lev

Right, the ipv6 was added indeed differently, without this conditionals.

You missed the part that JJO's IPv6 code *was* added with conditionals, and that caused problems.  We *removed* the conditionals, and the resulting code is easier to maintain now.

Quoted 4 lines

Because of this I did not perform this task as part of the major build cleanup, and left this for the next phase.
Most of the lowlevel network code already has #ifdefs, I will try my best to find a way to do the conditional without much changes.

I don't think that this is a useful way to spend your time.

Nobody has ever asked for it, and I don't see anybody volunteering to maintain the resulting extra complications.

We want to *reduce* the number of #ifdef in the code.

Quoted 1 line

We want to *reduce* the number of #ifdef in the code.

Not necessary, I would like to make it compatible with other well behaved projects out there.

These days it is highly unlikely that OpenVPN will be built in a non-IPv6 capable Linux environment.  So remove compile-time related macros identifying that.

This also solves an issue which was introduced in commit 51bd56f46f55177cf0f8b where HAVE_TUN_PI is no longer detected.  The tun_pi struct is defined in linux/if_tun.h, which will be checked for later on.  As this struct has history in linux/if_tun.h all back to the beginning of the kernel git tree (2.6.12-rc2, April 2005), it is considered not needed to check for this struct explicit.

[ v2: Commit 7c0a2b5f2b4409 modifies some of the checks this patch touches.  This patch just adopts to those changes ]

Signed-off-by David Sommerseth <[email protected]...>

---
 configure.ac      |    6 ------
 src/openvpn/tun.c |   19 -------------------

 2 files changed, 0 insertions(+), 25 deletions(-)

configure.ac +0 -0

index 8ac5ac4..e808cb4 100644
@@ -415,12 +415,6 @@ AC_CHECK_TYPES(

       [[${SOCKET_INCLUDES}]]
 )
 AC_CHECK_TYPE(
-       [struct tun_pi],
-       [AC_DEFINE([HAVE_TUN_PI], [1], [struct tun_pi needed for IPv6 support])],
-       ,
-       [[${SOCKET_INCLUDES}]]

configure.ac +0 -2

-)
-AC_CHECK_TYPE(

       [struct iphdr],
       [AC_DEFINE([HAVE_IPHDR], [1], [struct iphdr needed for IPv6 support])], ,

src/openvpn/tun.c +0 -8

index 227bfde..633150f 100644
@@ -1373,14 +1373,6 @@ close_tun_generic (struct tuntap *tt)
  #error header file linux/sockios.h required
  #endif
 
-#if defined(HAVE_TUN_PI) && defined(HAVE_IPHDR) && defined(HAVE_IOVEC) && defined(ETH_P_IPV6) && defined(ETH_P_IP) && defined(HAVE_READV) && defined(HAVE_WRITEV)
-#define LINUX_IPV6 1
-/* #warning IPv6 ON */
-#else
-#define LINUX_IPV6 0
-/* #warning IPv6 OFF */
-#endif
-
  #if !PEDANTIC
 

 void

src/openvpn/tun.c +0 -7

@@ -1388,13 +1380,6 @@ open_tun (const char *dev, const char *dev_type, const char *dev_node, struct tu
  {
   struct ifreq ifr;
 
-  /* warn if a very old linux version is used & --tun-ipv6 set
-   */
-#if LINUX_IPV6 == 0
-  if ( tt->ipv6 )
-    msg (M_WARN, "NOTE: explicit support for IPv6 tun devices is not provided for this OS");
-#endif
-
   /*
    * We handle --dev null specially, we do not open /dev/null for this.
    */

@@ -1623,7 +1608,6 @@ close_tun (struct tuntap *tt)

 int
 write_tun (struct tuntap* tt, uint8_t *buf, int len) {
-#if LINUX_IPV6
  if (tt->ipv6)
    {
      struct tun_pi pi;

src/openvpn/tun.c +0 -0

@@ -1649,14 +1633,12 @@ write_tun (struct tuntap* tt, uint8_t *buf, int len)
       return(ret - sizeof(pi));
     }

  else
-#endif
    return write (tt->fd, buf, len);
 }

 int
 read_tun (struct tuntap* tt, uint8_t *buf, int len) {
-#if LINUX_IPV6
  if (tt->ipv6)
    {
      struct iovec vect[2];

src/openvpn/tun.c +0 -0

@@ -1672,7 +1654,6 @@ read_tun (struct tuntap* tt, uint8_t *buf, int len)
       return(ret - sizeof(pi));
     }

  else
-#endif
    return read (tt->fd, buf, len);
 }

--
1.7.4.4

------------------------------------------------------------------------------
Live Security Virtual Conference
Exclusive live event will cover all the ways today's security and threat landscape has changed and how IT managers can respond. Discussions will include endpoint security, mobile security and the latest in malware threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/
_______________________________________________
Openvpn-devel mailing list [email protected]
https://lists.sourceforge.net/lists/listinfo/openvpn-devel

These days it is highly unlikely that OpenVPN will be built in a non-IPv6 capable Linux environment. So remove compile-time related macros identifying that.

This also solves an issue which was introduced in commit 51bd56f46f55177cf0f8b where HAVE_TUN_PI is no longer detected. The tun_pi struct is defined in linux/if_tun.h, which will be checked for later on. As this struct has history in linux/if_tun.h all back to the beginning of the kernel git tree (2.6.12-rc2, April 2005), it is considered not needed to check for this struct explicit.

[ v2: Commit 7c0a2b5f2b4409 modifies some of the checks this patch touches. This patch just adopts to those changes ]

Signed-off-by David Sommerseth <[email protected]...> ---

configure.ac | 6 ------ src/openvpn/tun.c | 19
------------------- 2 files changed, 0 insertions(+), 25 deletions(-)