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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
Daniel Borkmann