net: fill in MODULE_DESCRIPTION()s for ipv4 modules

W=1 builds now warn if module is built without a MODULE_DESCRIPTION().
Add descriptions to the IPv4 modules.

Signed-off-by: Breno Leitao <leitao@debian.org>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://lore.kernel.org/r/20240208164244.3818498-7-leitao@debian.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

net: Remove the member netns_ok

Every protocol has the 'netns_ok' member and it is euqal to 1. The
'if (!prot->netns_ok)' always false in inet_add_protocol().

Signed-off-by: Yejune Deng <yejunedeng@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

tunnel4: add cb_handler to struct xfrm_tunnel

This patch is to register a callback function tunnel4_rcv_cb with
is_ipip set in a xfrm_input_afinfo object for tunnel4 and tunnel64.

It will be called by xfrm_rcv_cb() from xfrm_input() when family
is AF_INET and proto is IPPROTO_IPIP or IPPROTO_IPV6.

v1->v2:
- Fix a sparse warning caused by the missing "__rcu", as Jakub
noticed.
- Handle the err returned by xfrm_input_register_afinfo() in
tunnel4_init/fini(), as Sabrina noticed.
v2->v3:
- Add "#if IS_ENABLED(CONFIG_INET_XFRM_TUNNEL)" to fix the build error
when xfrm is disabled, reported by kbuild test robot.

Signed-off-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>

treewide: Add SPDX license identifier for more missed files

Add SPDX license identifiers to all files which:

- Have no license information of any form

- Have MODULE_LICENCE("GPL*") inside which was used in the initial
scan/conversion to ignore the file

These files fall under the project license, GPL v2 only. The resulting SPDX
license identifier is:

GPL-2.0-only

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

net: Convert protocol error handlers from void to int

We'll need this to handle ICMP errors for tunnels without a sending socket
(i.e. FoU and GUE). There, we might have to look up different types of IP
tunnels, registered as network protocols, before we get a match, so we
want this for the error handlers of IPPROTO_IPIP and IPPROTO_IPV6 in both
inet_protos and inet6_protos. These error codes will be used in the next
patch.

For consistency, return sensible error codes in protocol error handlers
whenever handlers can't handle errors because, even if valid, they don't
match a protocol or any of its states.

This has no effect on existing error handling paths.

Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Reviewed-by: Sabrina Dubroca <sd@queasysnail.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

inet: whitespace cleanup

Ran simple script to find/remove trailing whitespace and blank lines
at EOF because that kind of stuff git whines about and editors leave
behind.

Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

tunnels: correct conditional build of MPLS and IPv6

Using a combination if #if conditionals and goto labels to unwind
tunnel4_init seems unwieldy. This patch takes a simpler approach of
directly unregistering previously registered protocols when an error
occurs.

This fixes a number of problems with the current implementation
including the potential presence of labels when they are unused
and the potential absence of unregister code when it is needed.

Fixes: 8afe97e5d416 ("tunnels: support MPLS over IPv4 tunnels")
Signed-off-by: Simon Horman <simon.horman@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

tunnels: support MPLS over IPv4 tunnels

Extend tunnel support to MPLS over IPv4. The implementation extends the
existing differentiation between IPIP and IPv6 over IPv4 to also cover MPLS
over IPv4.

Signed-off-by: Simon Horman <simon.horman@netronome.com>
Reviewed-by: Dinan Gunawardena <dinan.gunawardena@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: Convert printks to pr_<level>

Use a more current kernel messaging style.

Convert a printk block to print_hex_dump.
Coalesce formats, align arguments.
Use %s, __func__ instead of embedding function names.

Some messages that were prefixed with <foo>_close are
now prefixed with <foo>_fini. Some ah4 and esp messages
are now not prefixed with "ip ".

The intent of this patch is to later add something like
#define pr_fmt(fmt) "IPv4: " fmt.
to standardize the output messages.

Text size is trivially reduced. (x86-32 allyesconfig)

$ size net/ipv4/built-in.o*
text data bss dec hex filename
887888 31558 249696 1169142 11d6f6 net/ipv4/built-in.o.new
887934 31558 249800 1169292 11d78c net/ipv4/built-in.o.old

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: use IS_ENABLED(CONFIG_IPV6)

Instead of testing defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

tunnels: add __rcu annotations

Add __rcu annotations to :
(struct ip_tunnel)->prl
(struct ip_tunnel_prl_entry)->next
(struct xfrm_tunnel)->next
struct xfrm_tunnel *tunnel4_handlers
struct xfrm_tunnel *tunnel64_handlers

And use appropriate rcu primitives to reduce sparse warnings if
CONFIG_SPARSE_RCU_POINTER=y

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

tunnels: missing rcu_assign_pointer()

xfrm4_tunnel_register() & xfrm6_tunnel_register() should
use rcu_assign_pointer() to make sure previous writes
(to handler->next) are committed to memory before chain
insertion.

deregister functions dont need a particular barrier.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: tunnels should use rcu_dereference

tunnel4_handlers, tunnel64_handlers, tunnel6_handlers and
tunnel46_handlers are protected by RCU, but we dont use appropriate rcu
primitives to scan them. rcu_lock() is already held by caller.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: struct xfrm_tunnel in read_mostly section

tunnel4_handlers chain being scanned for each incoming packet,
make sure it doesnt share an often dirtied cache line.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/ipv4: EXPORT_SYMBOL cleanups

CodingStyle cleanups

EXPORT_SYMBOL should immediately follow the symbol declaration.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h

percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files. percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.

percpu.h -> slab.h dependency is about to be removed. Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability. As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.

http://userweb.kernel.org/~tj/misc/slabh-sweep.py

The script does the followings.

* Scan files for gfp and slab usages and update includes such that
only the necessary includes are there. ie. if only gfp is used,
gfp.h, if slab is used, slab.h.

* When the script inserts a new include, it looks at the include
blocks and try to put the new include such that its order conforms
to its surrounding. It's put in the include block which contains
core kernel includes, in the same order that the rest are ordered -
alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
doesn't seem to be any matching order.

* If the script can't find a place to put a new include (mostly
because the file doesn't have fitting include block), it prints out
an error message indicating which .h file needs to be added to the
file.

The conversion was done in the following steps.

1. The initial automatic conversion of all .c files updated slightly
over 4000 files, deleting around 700 includes and adding ~480 gfp.h
and ~3000 slab.h inclusions. The script emitted errors for ~400
files.

2. Each error was manually checked. Some didn't need the inclusion,
some needed manual addition while adding it to implementation .h or
embedding .c file was more appropriate for others. This step added
inclusions to around 150 files.

3. The script was run again and the output was compared to the edits
from #2 to make sure no file was left behind.

4. Several build tests were done and a couple of problems were fixed.
e.g. lib/decompress_*.c used malloc/free() wrappers around slab
APIs requiring slab.h to be added manually.

5. The script was run on all .h files but without automatically
editing them as sprinkling gfp.h and slab.h inclusions around .h
files could easily lead to inclusion dependency hell. Most gfp.h
inclusion directives were ignored as stuff from gfp.h was usually
wildly available and often used in preprocessor macros. Each
slab.h inclusion directive was examined and added manually as
necessary.

6. percpu.h was updated not to include slab.h.

7. Build test were done on the following configurations and failures
were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my
distributed build env didn't work with gcov compiles) and a few
more options had to be turned off depending on archs to make things
build (like ipr on powerpc/64 which failed due to missing writeq).

* x86 and x86_64 UP and SMP allmodconfig and a custom test config.
* powerpc and powerpc64 SMP allmodconfig
* sparc and sparc64 SMP allmodconfig
* ia64 SMP allmodconfig
* s390 SMP allmodconfig
* alpha SMP allmodconfig
* um on x86_64 SMP allmodconfig

8. percpu.h modifications were reverted so that it could be applied as
a separate patch and serve as bisection point.

Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.

Signed-off-by: Tejun Heo <tj@kernel.org>
Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>

net: constify struct net_protocol

Remove long removed "inet_protocol_base" declaration.

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

[IPV4] TUNNEL4: Fix incoming packet length check for inter-protocol tunnel.

Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>

[SIT]: Allow for IPPROTO_IPV6 protocol in namespaces.

This makes sit-generated traffic enter the namespace.

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

[IPIP]: Allow for IPPROTO_IPIP protocol in namespaces.

This one was disabled by default for sanity.

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

[INET]: Cleanup the xfrm4_tunnel_(un)register

Both check for the family to select an appropriate tunnel list.
Consolidate this check and make the for() loop more readable.

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

[INET]: Add missed tunnel64_err handler

The tunnel64_protocol uses the tunnel4_protocol's err_handler and
thus calls the tunnel4_protocol's handlers.

This is not very good, as in case of (icmp) error the wrong error
handlers will be called (e.g. ipip ones instead of sit) and this
won't be noticed at all, because the error is not reported.

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

[IPSEC]: Changing API of xfrm4_tunnel_register.

This patch changes xfrm4_tunnel register and deregister
interface to prepare for solving the conflict of device
tunnels with inter address family IPsec tunnel.

Signed-off-by: Kazunori MIYAZAWA <miyazawa@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

[INET]: Move no-tunnel ICMP error to tunnel4/tunnel6

This patch moves the sending of ICMP messages when there are no IPv4/IPv6
tunnels present to tunnel4/tunnel6 respectively. Please note that for now
if xfrm4_tunnel/xfrm6_tunnel is loaded then no ICMP messages will ever be
sent. This is similar to how we handle AH/ESP/IPCOMP.

This move fixes the bug where we always send an ICMP message when there is
no ip6_tunnel device present for a given packet even if it is later handled
by IPsec. It also causes ICMP messages to be sent when no IPIP tunnel is
present.

I've decided to use the "port unreachable" ICMP message over the current
value of "address unreachable" (and "protocol unreachable" by GRE) because
it is not ambiguous unlike the other ones which can be triggered by other
conditions. There seems to be no standard specifying what value must be
used so this change should be OK. In fact we should change GRE to use
this value as well.

Incidentally, this patch also fixes a fairly serious bug in xfrm6_tunnel
where we don't check whether the embedded IPv6 header is present before
dereferencing it for the inside source address.

This patch is inspired by a previous patch by Hugo Santos <hsantos@av.it.pt>.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>

[INET]: Introduce tunnel4/tunnel6

Basically this patch moves the generic tunnel protocol stuff out of
xfrm4_tunnel/xfrm6_tunnel and moves it into the new files of tunnel4.c
and tunnel6 respectively.

The reason for this is that the problem that Hugo uncovered is only
the tip of the iceberg. The real problem is that when we removed the
dependency of ipip on xfrm4_tunnel we didn't really consider the module
case at all.

For instance, as it is it's possible to build both ipip and xfrm4_tunnel
as modules and if the latter is loaded then ipip simply won't load.

After considering the alternatives I've decided that the best way out of
this is to restore the dependency of ipip on the non-xfrm-specific part
of xfrm4_tunnel. This is acceptable IMHO because the intention of the
removal was really to be able to use ipip without the xfrm subsystem.
This is still preserved by this patch.

So now both ipip/xfrm4_tunnel depend on the new tunnel4.c which handles
the arbitration between the two. The order of processing is determined
by a simple integer which ensures that ipip gets processed before
xfrm4_tunnel.

The situation for ICMP handling is a little bit more complicated since
we may not have enough information to determine who it's for. It's not
a big deal at the moment since the xfrm ICMP handlers are basically
no-ops. In future we can deal with this when we look at ICMP caching
in general.

The user-visible change to this is the removal of the TUNNEL Kconfig
prompts. This makes sense because it can only be used through IPCOMP
as it stands.

The addition of the new modules shouldn't introduce any problems since
module dependency will cause them to be loaded.

Oh and I also turned some unnecessary pskb's in IPv6 related to this
patch to skb's.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>