Hi,
if all I'm describing is completely logical and I'm only too dumb to see
the logic please forgive me. ;-)
In 2.5.64 there are networking headers both under include/linux/ and
include/net/. I don't understand whether there's a deeper logic why e.g.
the netfilter headers are under include/linux/.
There's some duplication, e.g. include/linux/in6.h contains
<-- snip -->
/*
* IPV6 extension headers
*/
#define IPPROTO_HOPOPTS 0 /* IPv6 hop-by-hop options */
#define IPPROTO_ROUTING 43 /* IPv6 routing header */
#define IPPROTO_FRAGMENT 44 /* IPv6 fragmentation header */
#define IPPROTO_ICMPV6 58 /* ICMPv6 */
#define IPPROTO_NONE 59 /* IPv6 no next header */
#define IPPROTO_DSTOPTS 60 /* IPv6 destination options */
<-- snip -->
and include/net/ipv6.h contains:
<-- snip -->
/*
* NextHeader field of IPv6 header
*/
#define NEXTHDR_HOP 0 /* Hop-by-hop option header. */
#define NEXTHDR_TCP 6 /* TCP segment. */
#define NEXTHDR_UDP 17 /* UDP message. */
#define NEXTHDR_IPV6 41 /* IPv6 in IPv6 */
#define NEXTHDR_ROUTING 43 /* Routing header. */
#define NEXTHDR_FRAGMENT 44 /* Fragmentation/reassembly header. */
#define NEXTHDR_ESP 50 /* Encapsulating security payload. */
#define NEXTHDR_AUTH 51 /* Authentication header. */
#define NEXTHDR_ICMP 58 /* ICMP for IPv6. */
#define NEXTHDR_NONE 59 /* No next header */
#define NEXTHDR_DEST 60 /* Destination options header. */
<-- snip -->
Two different #define's for the same thing doesn't sound like a good
idea?
cu
Adrian
--
"Is there not promise of rain?" Ling Tan asked suddenly out
of the darkness. There had been need of rain for many days.
"Only a promise," Lao Er said.
Pearl S. Buck - Dragon Seed
From: Adrian Bunk <[email protected]>
Date: Wed, 5 Mar 2003 23:54:41 +0100
Two different #define's for the same thing doesn't sound like a good
idea?
Required by the ipv6 advanced sockets API I do believe.
On Wed, 2003-03-05 at 14:54, ext Adrian Bunk wrote:
>
> There's some duplication, e.g. include/linux/in6.h contains
>
> /*
> * IPV6 extension headers
> */
> #define IPPROTO_HOPOPTS 0 /* IPv6 hop-by-hop options */
> #define IPPROTO_ROUTING 43 /* IPv6 routing header */
> #define IPPROTO_FRAGMENT 44 /* IPv6 fragmentation header */
> #define IPPROTO_ICMPV6 58 /* ICMPv6 */
> #define IPPROTO_NONE 59 /* IPv6 no next header */
> #define IPPROTO_DSTOPTS 60 /* IPv6 destination options */
According to RFC2292 (Advanced Sockets):
2.1.1. IPv6 Next Header Values
IPv6 defines many new values for the Next Header field. The
following constants are defined as a result of including
<netinet/in.h>.
#define IPPROTO_HOPOPTS 0 /* IPv6 Hop-by-Hop options */
#define IPPROTO_IPV6 41 /* IPv6 header */
#define IPPROTO_ROUTING 43 /* IPv6 Routing header */
#define IPPROTO_FRAGMENT 44 /* IPv6 fragmentation header */
#define IPPROTO_ESP 50 /* encapsulating security payload */
#define IPPROTO_AH 51 /* authentication header */
#define IPPROTO_ICMPV6 58 /* ICMPv6 */
#define IPPROTO_NONE 59 /* IPv6 no next header */
#define IPPROTO_DSTOPTS 60 /* IPv6 Destination options */
Berkeley-derived IPv4 implementations also define IPPROTO_IP to be 0.
This should not be a problem since IPPROTO_IP is used only with IPv4
sockets and IPPROTO_HOPOPTS only with IPv6 sockets.
>
> and include/net/ipv6.h contains:
>
> <-- snip -->
>
> /*
> * NextHeader field of IPv6 header
> */
>
> #define NEXTHDR_HOP 0 /* Hop-by-hop option header. */
> #define NEXTHDR_TCP 6 /* TCP segment. */
> #define NEXTHDR_UDP 17 /* UDP message. */
> #define NEXTHDR_IPV6 41 /* IPv6 in IPv6 */
> #define NEXTHDR_ROUTING 43 /* Routing header. */
> #define NEXTHDR_FRAGMENT 44 /* Fragmentation/reassembly header. */
This form doesn't appear in RFC2292, nor in 2133 (Basic Socket...)
My interpretation is that this latter form is defined for kernel use,
while the former is for user-level manipulation of raw packet fields
(the primary purpose of 2292).
Does it make sense to have two forms, one kernel, one user? I haven't
e.g. followed the desired include chain. If we wanted to merge the
uses, the former form and include location would probably have to be
used.
I've been looking into this. There are a *few* things missing from the
2292 support. AFAICT, it's just a handful of functions/macros for
manipulating option headers that need to be added.
Does anybody actually USE this stuff (the advanced sockets API, I mean,
not IPv6)? I'm planning to add those missing bits, just for kicks, but
haven't done it yet.
--Rod
From: Rod Van Meter <[email protected]>
Date: 05 Mar 2003 15:10:35 -0800
Does it make sense to have two forms, one kernel, one user? I haven't
e.g. followed the desired include chain. If we wanted to merge the
uses, the former form and include location would probably have to be
used.
I've been looking into this. There are a *few* things missing from the
2292 support. AFAICT, it's just a handful of functions/macros for
manipulating option headers that need to be added.
Actually forget all my comments, GLIBC headers are where
the advanced socket API requirements for headers should
be applied.
And since this is only used in the kernel, there is no need
for the NEXTHDR_* if it trully just duplicates the IPPROTO_*
defines.
I'm willing to accept a cleanup patch of this nature, sure.
On Wed, Mar 05, 2003 at 03:10:35PM -0800, Rod Van Meter wrote:
> On Wed, 2003-03-05 at 14:54, ext Adrian Bunk wrote:
> > There's some duplication, e.g. include/linux/in6.h contains
> >
> > /*
> > * IPV6 extension headers
> > */
> > #define IPPROTO_HOPOPTS 0 /* IPv6 hop-by-hop options */
> > #define IPPROTO_ROUTING 43 /* IPv6 routing header */
> > #define IPPROTO_FRAGMENT 44 /* IPv6 fragmentation header */
> > #define IPPROTO_ICMPV6 58 /* ICMPv6 */
> > #define IPPROTO_NONE 59 /* IPv6 no next header */
> > #define IPPROTO_DSTOPTS 60 /* IPv6 destination options */
>
>
> According to RFC2292 (Advanced Sockets):
>
> 2.1.1. IPv6 Next Header Values
>
> IPv6 defines many new values for the Next Header field. The
> following constants are defined as a result of including
> <netinet/in.h>.
>
> #define IPPROTO_HOPOPTS 0 /* IPv6 Hop-by-Hop options */
> #define IPPROTO_IPV6 41 /* IPv6 header */
> #define IPPROTO_ROUTING 43 /* IPv6 Routing header */
> #define IPPROTO_FRAGMENT 44 /* IPv6 fragmentation header */
> #define IPPROTO_ESP 50 /* encapsulating security payload */
> #define IPPROTO_AH 51 /* authentication header */
> #define IPPROTO_ICMPV6 58 /* ICMPv6 */
> #define IPPROTO_NONE 59 /* IPv6 no next header */
> #define IPPROTO_DSTOPTS 60 /* IPv6 Destination options */
>
> Berkeley-derived IPv4 implementations also define IPPROTO_IP to be 0.
> This should not be a problem since IPPROTO_IP is used only with IPv4
> sockets and IPPROTO_HOPOPTS only with IPv6 sockets.
The Linux FreeS/WAN IPsec implementation has been using IPPROTO_ESP,
IPPROTO_AH, IPPROTO_INT (61, put aside by IANA for internal use),
IPPROTO_COMP (108), IPPROTO_IPIP (4) for the last 5 years, based on
common usage and examples such as IPPROTO_UDP, IPPROTO_TCP, IPPROTO_ICMP.
> > and include/net/ipv6.h contains:
> >
> > <-- snip -->
> >
> > /*
> > * NextHeader field of IPv6 header
> > */
> >
> > #define NEXTHDR_HOP 0 /* Hop-by-hop option header. */
> > #define NEXTHDR_TCP 6 /* TCP segment. */
> > #define NEXTHDR_UDP 17 /* UDP message. */
> > #define NEXTHDR_IPV6 41 /* IPv6 in IPv6 */
> > #define NEXTHDR_ROUTING 43 /* Routing header. */
> > #define NEXTHDR_FRAGMENT 44 /* Fragmentation/reassembly header. */
>
> This form doesn't appear in RFC2292, nor in 2133 (Basic Socket...)
>
> My interpretation is that this latter form is defined for kernel use,
> while the former is for user-level manipulation of raw packet fields
> (the primary purpose of 2292).
We use these in the kernel, but not in userspace. We define SA_ESP,
etc...
> Does it make sense to have two forms, one kernel, one user? I haven't
> e.g. followed the desired include chain. If we wanted to merge the
> uses, the former form and include location would probably have to be
> used.
We use the two forms since shared user/kernel headers are a nuisance...
> I've been looking into this. There are a *few* things missing from the
> 2292 support. AFAICT, it's just a handful of functions/macros for
> manipulating option headers that need to be added.
>
> Does anybody actually USE this stuff (the advanced sockets API, I mean,
> not IPv6)? I'm planning to add those missing bits, just for kicks, but
> haven't done it yet.
>
> --Rod
slainte mhath, RGB
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