netfilter: ipvs: prefer skb_ensure_writable

It does the same thing, use it instead so we can remove skb_make_writable.

Signed-off-by: Florian Westphal <fw@strlen.de>
Acked-by: Simon Horman <horms@verge.net.au>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

ipvs: get sctphdr by sctphoff in sctp_csum_check

sctp_csum_check() is called by sctp_s/dnat_handler() where it calls
skb_make_writable() to ensure sctphdr to be linearized.

So there's no need to get sctphdr by calling skb_header_pointer()
in sctp_csum_check().

Signed-off-by: Xin Long <lucien.xin@gmail.com>
Reviewed-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Acked-by: Julian Anastasov <ja@ssi.bg>
Acked-by: Simon Horman <horms@verge.net.au>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

ipvs: avoid indirect calls when calculating checksums

The function pointer ip_vs_protocol->csum_check is only used in protocol
specific code, and never in the generic one.
Remove the function pointer from struct ip_vs_protocol and call the
checksum functions directly.
This reduces the performance impact of the Spectre mitigation, and
should give a small improvement even with RETPOLINES disabled.

Signed-off-by: Matteo Croce <mcroce@redhat.com>
Acked-by: Julian Anastasov <ja@ssi.bg>
Acked-by: Simon Horman <horms@verge.net.au>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

ipvs: add assured state for conn templates

cp->state was not used for templates. Add support for state bits
and for the first "assured" bit which indicates that some
connection controlled by this template was established or assured
by the real server. In a followup patch we will use it to drop
templates under SYN attack.

Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

ipvs: add ipv6 support to ftp

Add support for FTP commands with extended format (RFC 2428):

- FTP EPRT: IPv4 and IPv6, active mode, similar to PORT
- FTP EPSV: IPv4 and IPv6, passive mode, similar to PASV.
EPSV response usually contains only port but we allow real
server to provide different address

We restrict control and data connection to be from same
address family.

Allow the "(" and ")" to be optional in PASV response.

Also, add ipvsh argument to the pkt_in/pkt_out handlers to better
access the payload after transport header.

Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

License cleanup: add SPDX GPL-2.0 license identifier to files with no license

Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.

By default all files without license information are under the default
license of the kernel, which is GPL version 2.

Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier. The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.

This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.

How this work was done:

Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
- file had no licensing information it it.
- file was a */uapi/* one with no licensing information in it,
- file was a */uapi/* one with existing licensing information,

Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.

The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode & Windriver) producing SPDX
tag:value files created by Philippe Ombredanne. Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.

The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed. Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.

Criteria used to select files for SPDX license identifier tagging was:
- Files considered eligible had to be source code files.
- Make and config files were included as candidates if they contained >5
lines of source
- File already had some variant of a license header in it (even if <5
lines).

All documentation files were explicitly excluded.

The following heuristics were used to determine which SPDX license
identifiers to apply.

- when both scanners couldn't find any license traces, file was
considered to have no license information in it, and the top level
COPYING file license applied.

For non */uapi/* files that summary was:

SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 11139

and resulted in the first patch in this series.

If that file was a */uapi/* path one, it was "GPL-2.0 WITH
Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was:

SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 WITH Linux-syscall-note 930

and resulted in the second patch in this series.

- if a file had some form of licensing information in it, and was one
of the */uapi/* ones, it was denoted with the Linux-syscall-note if
any GPL family license was found in the file or had no licensing in
it (per prior point). Results summary:

SPDX license identifier # files
---------------------------------------------------|------
GPL-2.0 WITH Linux-syscall-note 270
GPL-2.0+ WITH Linux-syscall-note 169
((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21
((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17
LGPL-2.1+ WITH Linux-syscall-note 15
GPL-1.0+ WITH Linux-syscall-note 14
((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5
LGPL-2.0+ WITH Linux-syscall-note 4
LGPL-2.1 WITH Linux-syscall-note 3
((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3
((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1

and that resulted in the third patch in this series.

- when the two scanners agreed on the detected license(s), that became
the concluded license(s).

- when there was disagreement between the two scanners (one detected a
license but the other didn't, or they both detected different
licenses) a manual inspection of the file occurred.

- In most cases a manual inspection of the information in the file
resulted in a clear resolution of the license that should apply (and
which scanner probably needed to revisit its heuristics).

- When it was not immediately clear, the license identifier was
confirmed with lawyers working with the Linux Foundation.

- If there was any question as to the appropriate license identifier,
the file was flagged for further research and to be revisited later
in time.

In total, over 70 hours of logged manual review was done on the
spreadsheet to determine the SPDX license identifiers to apply to the
source files by Kate, Philippe, Thomas and, in some cases, confirmation
by lawyers working with the Linux Foundation.

Kate also obtained a third independent scan of the 4.13 code base from
FOSSology, and compared selected files where the other two scanners
disagreed against that SPDX file, to see if there was new insights. The
Windriver scanner is based on an older version of FOSSology in part, so
they are related.

Thomas did random spot checks in about 500 files from the spreadsheets
for the uapi headers and agreed with SPDX license identifier in the
files he inspected. For the non-uapi files Thomas did random spot checks
in about 15000 files.

In initial set of patches against 4.14-rc6, 3 files were found to have
copy/paste license identifier errors, and have been fixed to reflect the
correct identifier.

Additionally Philippe spent 10 hours this week doing a detailed manual
inspection and review of the 12,461 patched files from the initial patch
version early this week with:
- a full scancode scan run, collecting the matched texts, detected
license ids and scores
- reviewing anything where there was a license detected (about 500+
files) to ensure that the applied SPDX license was correct
- reviewing anything where there was no detection but the patch license
was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
SPDX license was correct

This produced a worksheet with 20 files needing minor correction. This
worksheet was then exported into 3 different .csv files for the
different types of files to be modified.

These .csv files were then reviewed by Greg. Thomas wrote a script to
parse the csv files and add the proper SPDX tag to the file, in the
format that the file expected. This script was further refined by Greg
based on the output to detect more types of files automatically and to
distinguish between header and source .c files (which need different
comment types.) Finally Greg ran the script using the .csv files to
generate the patches.

Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

netfilter: ipvs: do not create conn for ABORT packet in sctp_conn_schedule

There's no reason for ipvs to create a conn for an ABORT packet
even if sysctl_sloppy_sctp is set.

This patch is to accept it without creating a conn, just as ipvs
does for tcp's RST packet.

Signed-off-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: Simon Horman <horms@verge.net.au>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

netfilter: ipvs: fix the issue that sctp_conn_schedule drops non-INIT packet

Commit 5e26b1b3abce ("ipvs: support scheduling inverse and icmp SCTP
packets") changed to check packet type early. It introduced a side
effect: if it's not a INIT packet, ports will be set as NULL, and
the packet will be dropped later.

It caused that sctp couldn't create connection when ipvs module is
loaded and any scheduler is registered on server.

Li Shuang reproduced it by running the cmds on sctp server:
# ipvsadm -A -t 1.1.1.1:80 -s rr
# ipvsadm -D -t 1.1.1.1:80
then the server could't work any more.

This patch is to return 1 when it's not an INIT packet. It means ipvs
will accept it without creating a conn for it, just like what it does
for tcp.

Fixes: 5e26b1b3abce ("ipvs: support scheduling inverse and icmp SCTP packets")
Reported-by: Li Shuang <shuali@redhat.com>
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: Simon Horman <horms@verge.net.au>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

netfilter: Remove duplicated rcu_read_lock.

This patch removes duplicate rcu_read_lock().

1. IPVS part:

According to Julian Anastasov's mention, contexts of ipvs are described
at: http://marc.info/?l=netfilter-devel&m=149562884514072&w=2, in summary:

- packet RX/TX: does not need locks because packets come from hooks.
- sync msg RX: backup server uses RCU locks while registering new
connections.
- ip_vs_ctl.c: configuration get/set, RCU locks needed.
- xt_ipvs.c: It is a netfilter match, running from hook context.

As result, rcu_read_lock and rcu_read_unlock can be removed from:

- ip_vs_core.c: all
- ip_vs_ctl.c:
- only from ip_vs_has_real_service
- ip_vs_ftp.c: all
- ip_vs_proto_sctp.c: all
- ip_vs_proto_tcp.c: all
- ip_vs_proto_udp.c: all
- ip_vs_xmit.c: all (contains only packet processing)

2. Netfilter part:

There are three types of functions that are guaranteed the rcu_read_lock().
First, as result, functions are only called by nf_hook():

- nf_conntrack_broadcast_help(), pptp_expectfn(), set_expected_rtp_rtcp().
- tcpmss_reverse_mtu(), tproxy_laddr4(), tproxy_laddr6().
- match_lookup_rt6(), check_hlist(), hashlimit_mt_common().
- xt_osf_match_packet().

Second, functions that caller already held the rcu_read_lock().
- destroy_conntrack(), ctnetlink_conntrack_event().
- ctnl_timeout_find_get(), nfqnl_nf_hook_drop().

Third, functions that are mixed with type1 and type2.

These functions are called by nf_hook() also these are called by
ordinary functions that already held the rcu_read_lock():

- __ctnetlink_glue_build(), ctnetlink_expect_event().
- ctnetlink_proto_size().

Applied files are below:

- nf_conntrack_broadcast.c, nf_conntrack_core.c, nf_conntrack_netlink.c.
- nf_conntrack_pptp.c, nf_conntrack_sip.c, nfnetlink_cttimeout.c.
- nfnetlink_queue.c, xt_TCPMSS.c, xt_TPROXY.c, xt_addrtype.c.
- xt_connlimit.c, xt_hashlimit.c, xt_osf.c

Detailed calltrace can be found at:
http://marc.info/?l=netfilter-devel&m=149667610710350&w=2

Signed-off-by: Taehee Yoo <ap420073@gmail.com>
Acked-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

sctp: remove the typedef sctp_chunkhdr_t

This patch is to remove the typedef sctp_chunkhdr_t, and replace
with struct sctp_chunkhdr in the places where it's using this
typedef.

It is also to fix some indents and use sizeof(variable) instead
of sizeof(type)., especially in sctp_new.

Signed-off-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

sctp: remove the typedef sctp_sctphdr_t

This patch is to remove the typedef sctp_sctphdr_t, and replace
with struct sctphdr in the places where it's using this typedef.

It is also to fix some indents and use sizeof(variable) instead
of sizeof(type).

Signed-off-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

netfilter: refcounter conversions

refcount_t type and corresponding API (see include/linux/refcount.h)
should be used instead of atomic_t when the variable is used as
a reference counter. This allows to avoid accidental
refcounter overflows that might lead to use-after-free
situations.

Signed-off-by: Elena Reshetova <elena.reshetova@intel.com>
Signed-off-by: Hans Liljestrand <ishkamiel@gmail.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: David Windsor <dwindsor@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

sctp: Rename NETIF_F_SCTP_CSUM to NETIF_F_SCTP_CRC

The SCTP checksum is really a CRC and is very different from the
standards 1's complement checksum that serves as the checksum
for IP protocols. This offload interface is also very different.
Rename NETIF_F_SCTP_CSUM to NETIF_F_SCTP_CRC to highlight these
differences. The term CSUM should be reserved in the stack to refer
to the standard 1's complement IP checksum.

Signed-off-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

ipvs: Pass ipvs into .conn_schedule and ip_vs_try_to_schedule

This moves the hack "net_ipvs(skb_net(skb))" up one level where it
will be easier to remove.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Acked-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>

ipvs: Pass ipvs not net into init_netns and exit_netns

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Acked-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>

ipvs: Pass ipvs not net into register_app and unregister_app

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Acked-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>

ipvs: Pass ipvs not net to ip_vs_proto_data_get

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Acked-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>

ipvs: Pass ipvs not net to ip_vs_service_find

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Acked-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>

ipvs: Store ipvs not net in struct ip_vs_conn

In practice struct netns_ipvs is as meaningful as struct net and more
useful as it holds the ipvs specific data. So store a pointer to
struct netns_ipvs.

Update the accesses of conn->net to access conn->ipvs->net instead.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Acked-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>

ipvs: Hoist computation of ipvs earlier in sctp_conn_schedule

The addition of sysctl_sloppy_sctp in sctp_conn_schedule resulted
in a use of ipvs before it was computed. Hoist the computation of
ipvs earlier to avoid this problem.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Acked-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>

ipvs: support scheduling inverse and icmp SCTP packets

In the event of an icmp packet, take only the ports instead of trying to
grab the full header.

In the event of an inverse packet, use the source address and port.

Signed-off-by: Alex Gartrell <agartrell@fb.com>
Acked-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>

ipvs: attempt to schedule icmp packets

Invoke the try_to_schedule logic from the icmp path and update it to the
appropriate ip_vs_conn_put function. The schedule functions have been
updated to reject the packets immediately for now.

Signed-off-by: Alex Gartrell <agartrell@fb.com>
Acked-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>

ipvs: use the new dest addr family field

Use the new address family field cp->daf when printing
cp->daddr in logs or connection listing.

Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Alex Gartrell <agartrell@fb.com>
Signed-off-by: Simon Horman <horms@verge.net.au>

net: ipvs: sctp: do not recalc sctp csum when ports didn't change

Unlike UDP or TCP, we do not take the pseudo-header into
account in SCTP checksums. So in case port mapping is the
very same, we do not need to recalculate the whole SCTP
checksum in software, which is very expensive.

Also, similarly as in TCP, take into account when a private
helper mangled the packet. In that case, we also need to
recalculate the checksum even if ports might be same.

Thanks for feedback regarding skb->ip_summed checks from
Julian Anastasov; here's a discussion on these checks for
snat and dnat:

* For snat_handler(), we can see CHECKSUM_PARTIAL from
virtual devices, and from LOCAL_OUT, otherwise it
should be CHECKSUM_UNNECESSARY. In general, in snat it
is more complex. skb contains the original route and
ip_vs_route_me_harder() can change the route after
snat_handler. So, for locally generated replies from
local server we can not preserve the CHECKSUM_PARTIAL
mode. It is an chicken or egg dilemma: snat_handler
needs the device after rerouting (to check for
NETIF_F_SCTP_CSUM), while ip_route_me_harder() wants
the snat_handler() to put the new saddr for proper
rerouting.

* For dnat_handler(), we should not see CHECKSUM_COMPLETE
for SCTP, in fact the small set of drivers that support
SCTP offloading return CHECKSUM_UNNECESSARY on correctly
received SCTP csum. We can see CHECKSUM_PARTIAL from
local stack or received from virtual drivers. The idea is
that SCTP decides to avoid csum calculation if hardware
supports offloading. IPVS can change the device after
rerouting to real server but we can preserve the
CHECKSUM_PARTIAL mode if the new device supports
offloading too. This works because skb dst is changed
before dnat_handler and we see the new device. So, checks
in the 'if' part will decide whether it is ok to keep
CHECKSUM_PARTIAL for the output. If the packet was with
CHECKSUM_NONE, hence we deal with unknown checksum. As we
recalculate the sum for IP header in all cases, it should
be safe to use CHECKSUM_UNNECESSARY. We can forward wrong
checksum in this case (without cp->app). In case of
CHECKSUM_UNNECESSARY, the csum was valid on receive.

Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>

net: ipvs: sctp: add missing verdict assignments in sctp_conn_schedule

If skb_header_pointer() fails, we need to assign a verdict, that is
NF_DROP in this case, otherwise, we would leave the verdict from
conn_schedule() uninitialized when returning.

Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Acked-by: Jesper Dangaard Brouer <brouer@redhat.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Acked-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>

net/sctp: Refactor SCTP skb checksum computation

This patch consolidates the SCTP checksum calculation code from various
places to a single new function, sctp_compute_cksum(skb, offset).

Signed-off-by: Joe Stringer <joe@wand.net.nz>
Reviewed-by: Julian Anastasov <ja@ssi.bg>
Acked-by: Simon Horman <horms@verge.net.au>
Signed-off-by: David S. Miller <davem@davemloft.net>

ipvs: replace the SCTP state machine

Convert the SCTP state table, so that it is more readable.
Change the states to be according to the diagram in RFC 2960
and add more states suitable for middle box. Still, such
change in states adds incompatibility if systems in sync
setup include this change and others do not include it.

With this change we also have proper transitions in INPUT-ONLY
mode (DR/TUN) where we see packets only from client. Now
we should not switch to 10-second CLOSED state at a time
when we should stay in ESTABLISHED state.

The short names for states are because we have 16-char space
in ipvsadm and 11-char limit for the connection list format.
It is a sequence of the TCP implementation where the longest
state name is ESTABLISHED.

Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>

ipvs: sloppy TCP and SCTP

This adds support for sloppy TCP and SCTP modes to IPVS.

When enabled (sysctls net.ipv4.vs.sloppy_tcp and
net.ipv4.vs.sloppy_sctp), allows IPVS to create connection state on any
packet, not just a TCP SYN (or SCTP INIT).

This allows connections to fail over from one IPVS director to another
mid-flight.

Signed-off-by: Alexander Frolkin <avf@eldamar.org.uk>
Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>

ipvs: off by one in set_sctp_state()

The sctp_events[] come from sch->type in set_sctp_state(). They are
between 0-255 so that means we need 256 elements in the array.

I believe that because of how the code is aligned there is normally a
hole after sctp_events[] so this patch doesn't actually change anything.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>

ipvs: do not disable bh for long time

We used a global BH disable in LOCAL_OUT hook.
Add _bh suffix to all places that need it and remove
the disabling from LOCAL_OUT and sync code.

Functions like ip_defrag need protection from
BH, so add it. As for nf_nat_mangle_tcp_packet, it needs
RCU lock.

Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>

ipvs: convert services to rcu

This is the final step in RCU conversion.

Things that are removed:

- svc->usecnt: now svc is accessed under RCU read lock
- svc->inc: and some unused code
- ip_vs_bind_pe and ip_vs_unbind_pe: no ability to replace PE
- __ip_vs_svc_lock: replaced with RCU
- IP_VS_WAIT_WHILE: now readers lookup svcs and dests under
RCU and work in parallel with configuration

Other changes:

- before now, a RCU read-side critical section included the
calling of the schedule method, now it is extended to include
service lookup
- ip_vs_svc_table and ip_vs_svc_fwm_table are now using hlist
- svc->pe and svc->scheduler remain to the end (of grace period),
the schedulers are prepared for such RCU readers
even after done_service is called but they need
to use synchronize_rcu because last ip_vs_scheduler_put
can happen while RCU read-side critical sections
use an outdated svc->scheduler pointer
- as planned, update_service is removed
- empty services can be freed immediately after grace period.
If dests were present, the services are freed from
the dest trash code

Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>

ipvs: convert app locks

We use locks like tcp_app_lock, udp_app_lock,
sctp_app_lock to protect access to the protocol hash tables
from readers in packet context while the application
instances (inc) are [un]registered under global mutex.

As the hash tables are mostly read when conns are
created and bound to app, use RCU for readers and reclaim
app instance after grace period.

Simplify ip_vs_app_inc_get because we use usecnt
only for statistics and rely on module refcounting.

Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off by: Hans Schillstrom <hans@schillstrom.com>
Signed-off-by: Simon Horman <horms@verge.net.au>

ipvs: fix sctp chunk length order

Fix wrong but non-fatal access to chunk length.
sch->length should be in network order, next chunk should
be aligned to 4 bytes. Problem noticed in sparse output.

Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>

ipvs: sctp: fix checksumming on snat and dnat handlers

In our test lab, we have a simple SCTP client connecting to a SCTP
server via an IPVS load balancer. On some machines, load balancing
works, but on others the initial handshake just fails, thus no
SCTP connection whatsoever can be established!

We observed that the SCTP INIT-ACK handshake reply from the IPVS
machine to the client had a correct IP checksum, but corrupt SCTP
checksum when forwarded, thus on the client-side the packet was
dropped and an intial handshake retriggered until all attempts
run into the void.

To fix this issue, this patch i) adds a missing CHECKSUM_UNNECESSARY
after the full checksum (re-)calculation (as done in IPVS TCP and UDP
code as well), ii) calculates the checksum in little-endian format
(as fixed with the SCTP code in commit 4458f04c: sctp: Clean up sctp
checksumming code) and iii) refactors duplicate checksum code into a
common function. Tested by myself.

Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Acked-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>

ipvs: API change to avoid rescan of IPv6 exthdr

Reduce the number of times we scan/skip the IPv6 exthdrs.

This patch contains a lot of API changes. This is done, to avoid
repeating the scan of finding the IPv6 headers, via ipv6_find_hdr(),
which is called by ip_vs_fill_iph_skb().

Finding the IPv6 headers is done as early as possible, and passed on
as a pointer "struct ip_vs_iphdr *" to the affected functions.

This patch reduce/removes 19 calls to ip_vs_fill_iph_skb().

Notice, I have choosen, not to change the API of function
pointer "(*schedule)" (in struct ip_vs_scheduler) as it can be
used by external schedulers, via {un,}register_ip_vs_scheduler.
Only 4 out of 10 schedulers use info from ip_vs_iphdr*, and when
they do, they are only interested in iph->{s,d}addr.

Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Acked-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>

ipvs: Fix faulty IPv6 extension header handling in IPVS

IPv6 packets can contain extension headers, thus its wrong to assume
that the transport/upper-layer header, starts right after (struct
ipv6hdr) the IPv6 header. IPVS uses this false assumption, and will
write SNAT & DNAT modifications at a fixed pos which will corrupt the
message.

To fix this, proper header position must be found before modifying
packets. Introducing ip_vs_fill_iph_skb(), which uses ipv6_find_hdr()
to skip the exthdrs. It finds (1) the transport header offset, (2) the
protocol, and (3) detects if the packet is a fragment.

Note, that fragments in IPv6 is represented via an exthdr. Thus, this
is detected while skipping through the exthdrs.

This patch depends on commit 84018f55a:
"netfilter: ip6_tables: add flags parameter to ipv6_find_hdr()"
This also adds a dependency to ip6_tables.

Originally based on patch from: Hans Schillstrom

kABI notes:
Changing struct ip_vs_iphdr is a potential minor kABI breaker,
because external modules can be compiled with another version of
this struct. This should not matter, as they would most-likely
be using a compiled-in version of ip_vs_fill_iphdr(). When
recompiled, they will notice ip_vs_fill_iphdr() no longer exists,
and they have to used ip_vs_fill_iph_skb() instead.

Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Acked-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>

ipvs: take care of return value from protocol init_netns

ip_vs_create_timeout_table() can return NULL
All functions protocol init_netns is affected of this patch.

Signed-off-by: Hans Schillstrom <hans.schillstrom@ericsson.com>
Acked-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>

ipvs: Remove unused return value of protocol state transitions

Acked-by: Julian Anastasov <ja@ssi.bg>
Acked-by Hans Schillstrom <hans@schillstrom.com>
Signed-off-by: Simon Horman <horms@verge.net.au>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

Fix common misspellings

Fixes generated by 'codespell' and manually reviewed.

Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>

IPVS: Use correct lock in SCTP module

Use sctp_app_lock instead of tcp_app_lock in the SCTP protocol module.

This appears to be a typo introduced by the netns changes.

Signed-off-by: Simon Horman <horms@verge.net.au>
Signed-off-by: Hans Schillstrom <hans.schillstrom@ericsson.com>

IPVS: netns, ip_vs_ctl local vars moved to ipvs struct.

Moving global vars to ipvs struct, except for svc table lock.
Next patch for ctl will be drop-rate handling.

*v3
__ip_vs_mutex remains global
ip_vs_conntrack_enabled(struct netns_ipvs *ipvs)

Signed-off-by: Hans Schillstrom <hans.schillstrom@ericsson.com>
Acked-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>

IPVS: netns, connection hash got net as param.

Connection hash table is now name space aware.
i.e. net ptr >> 8 is xor:ed to the hash,
and this is the first param to be compared.
The net struct is 0xa40 in size ( a little bit smaller for 32 bit arch:s)
and cache-line aligned, so a ptr >> 5 might be a more clever solution ?

All lookups where net is compared uses net_eq() which returns 1 when netns
is disabled, and the compiler seems to do something clever in that case.

ip_vs_conn_fill_param() have *net as first param now.

Three new inlines added to keep conn struct smaller
when names space is disabled.
- ip_vs_conn_net()
- ip_vs_conn_net_set()
- ip_vs_conn_net_eq()

*v3
moved net compare to the end in "fast path"

Signed-off-by: Hans Schillstrom <hans.schillstrom@ericsson.com>
Acked-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>

IPVS: netns awareness to ip_vs_app

All variables moved to struct ipvs,
most external changes fixed (i.e. init_net removed)

in ip_vs_protocol param struct net *net added to:
- register_app()
- unregister_app()
This affected almost all proto_xxx.c files

Signed-off-by: Hans Schillstrom <hans.schillstrom@ericsson.com>
Acked-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>

IPVS: netns, common protocol changes and use of appcnt.

appcnt and timeout_table moved from struct ip_vs_protocol to
ip_vs proto_data.

struct net *net added as first param to
- register_app()
- unregister_app()
- app_conn_bind()
- ip_vs_conn_new()

[horms@verge.net.au: removed cosmetic-change-only hunk]
Signed-off-by: Hans Schillstrom <hans.schillstrom@ericsson.com>
Acked-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>

IPVS: netns, use ip_vs_proto_data as param.

ip_vs_protocol *pp is replaced by ip_vs_proto_data *pd in
function call in ip_vs_protocol struct i.e. :,
- timeout_change()
- state_transition()

ip_vs_protocol_timeout_change() got ipvs as param, due to above
and a upcoming patch - defence work

Most of this changes are triggered by Julians comment:
"tcp_timeout_change should work with the new struct ip_vs_proto_data
so that tcp_state_table will go to pd->state_table
and set_tcp_state will get pd instead of pp"

*v3
Mostly comments from Julian
The pp -> pd conversion should start from functions like
ip_vs_out() that use pp = ip_vs_proto_get(iph.protocol),
now they should use ip_vs_proto_data_get(net, iph.protocol).
conn_in_get() and conn_out_get() unused param *pp, removed.

*v4
ip_vs_protocol_timeout_change() walk the proto_data path.

Signed-off-by: Hans Schillstrom <hans.schillstrom@ericsson.com>
Acked-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>

IPVS: netns preparation for proto_sctp

In this phase (one), all local vars will be moved to ipvs struct.

Remaining work, add param struct net *net to a couple of
functions that is common for all protos and use ip_vs_proto_data

*v3
Removed unuset function set_state_timeout()

Signed-off-by: Hans Schillstrom <hans.schillstrom@ericsson.com>
Acked-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>

IPVS: netns to services part 1

Services hash tables got netns ptr a hash arg,
While Real Servers (rs) has been moved to ipvs struct.
Two new inline functions added to get net ptr from skb.

Since ip_vs is called from different contexts there is two
places to dig for the net ptr skb->dev or skb->sk
this is handled in skb_net() and skb_sknet()

Global functions, ip_vs_service_get() ip_vs_lookup_real_service()
etc have got struct net *net as first param.
If possible get net ptr skb etc,
- if not &init_net is used at this early stage of patching.

ip_vs_ctl.c procfs not ready for netns yet.

*v3
Comments by Julian
- __ip_vs_service_find and __ip_vs_svc_fwm_find are fast path,
net_eq(svc->net, net) so the check is at the end now.
- net = skb_net(skb) in ip_vs_out moved after check for skb_dst.

Signed-off-by: Hans Schillstrom <hans.schillstrom@ericsson.com>
Acked-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>

IPVS: Handle Scheduling errors.

If ip_vs_conn_fill_param_persist return an error to ip_vs_sched_persist,
this error must propagate as ignored=-1 to ip_vs_schedule().
Errors from ip_vs_conn_new() in ip_vs_sched_persist() and ip_vs_schedule()
should also return *ignored=-1;

This patch just relies on the fact that ignored is 1 before calling
ip_vs_sched_persist().

Sent from Julian:
"The new case when ip_vs_conn_fill_param_persist fails
should set *ignored = -1, so that we can use NF_DROP,
see below. *ignored = -1 should be also used for ip_vs_conn_new
failure in ip_vs_sched_persist() and ip_vs_schedule().
The new negative value should be handled in tcp,udp,sctp"

"To summarize:

- *ignored = 1:
protocol tried to schedule (eg. on SYN), found svc but the
svc/scheduler decides that this packet should be accepted with
NF_ACCEPT because it must not be scheduled.

- *ignored = 0:
scheduler can not find destination, so try bypass or
return ICMP and then NF_DROP (ip_vs_leave).

- *ignored = -1:
scheduler tried to schedule but fatal error occurred, eg.
ip_vs_conn_new failure (ENOMEM) or ip_vs_sip_fill_param
failure such as missing Call-ID, ENOMEM on skb_linearize
or pe_data. In this case we should return NF_DROP without
any attempts to send ICMP with ip_vs_leave."

More or less all ideas and input to this patch is work from
Julian Anastasov

Signed-off-by: Hans Schillstrom <hans.schillstrom@ericsson.com>
Acked-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>

ipvs: provide address family for debugging

As skb->protocol is not valid in LOCAL_OUT add
parameter for address family in packet debugging functions.
Even if ports are not present in AH and ESP change them to
use ip_vs_tcpudp_debug_packet to show at least valid addresses
as before. This patch removes the last user of skb->protocol
in IPVS.

Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>

ipvs: do not schedule conns from real servers

This patch is needed to avoid scheduling of
packets from local real server when we add ip_vs_in
in LOCAL_OUT hook to support local client.

Currently, when ip_vs_in can not find existing
connection it tries to create new one by calling ip_vs_schedule.

The default indication from ip_vs_schedule was if
connection was scheduled to real server. If real server is
not available we try to use the bypass forwarding method
or to send ICMP error. But in some cases we do not want to use
the bypass feature. So, add flag 'ignored' to indicate if
the scheduler ignores this packet.

Make sure we do not create new connections from replies.
We can hit this problem for persistent services and local real
server when ip_vs_in is added to LOCAL_OUT hook to handle
local clients.

Also, make sure ip_vs_schedule ignores SYN packets
for Active FTP DATA from local real server. The FTP DATA
connection should be created on SYN+ACK from client to assign
correct connection daddr.

Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>

ipvs: Use frag walker helper in SCTP proto support.

Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Simon Horman <horms@verge.net.au>

ipvs: provide default ip_vs_conn_{in,out}_get_proto

This removes duplicate code by providing a default implementation
which is used by 3 of the 4 modules that provide these call.

Signed-off-by: Simon Horman <horms@verge.net.au>
Signed-off-by: Patrick McHardy <kaber@trash.net>

ipvs: lvs sctp protocol handler is incorrectly invoked ip_vs_app_pkt_out

lvs sctp protocol handler is incorrectly invoked ip_vs_app_pkt_out
Since there's no sctp helpers at present, it does the same thing as
ip_vs_app_pkt_in.

Signed-off-by: Xiaoyu Du <tingsrain@gmail.com>
Acked-by: Simon Horman <horms@verge.net.au>
Signed-off-by: Patrick McHardy <kaber@trash.net>

ipvs: SCTP Trasport Loadbalancing Support

Enhance IPVS to load balance SCTP transport protocol packets. This is done
based on the SCTP rfc 4960. All possible control chunks have been taken
care. The state machine used in this code looks some what lengthy. I tried
to make the state machine easy to understand.

Signed-off-by: Venkata Mohan Reddy Koppula <mohanreddykv@gmail.com>
Signed-off-by: Simon Horman <horms@verge.net.au>
Signed-off-by: Patrick McHardy <kaber@trash.net>