ip6_route_output() will never return a NULL pointer, so there's no need
to check it.
Signed-off-by: Liping Zhang <liping.zhang@spreadtrum.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Replace '64' with the per-net ipv6_devconf_all's hop_limit when
building the ipv6 header.
Signed-off-by: Liping Zhang <liping.zhang@spreadtrum.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This merge resolves conflicts with 75aec9df3a ("bridge: Remove
br_nf_push_frag_xmit_sk") as part of Eric Biederman's effort to improve
netns support in the network stack that reached upstream via David's
net-next tree.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Conflicts:
net/bridge/br_netfilter_hooks.c
since commit 8405a8fff3 ("netfilter: nf_qeueue: Drop queue entries on
nf_unregister_hook") all pending queued entries are discarded.
So we can simply remove all of the owner handling -- when module is
removed it also needs to unregister all its hooks.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Use tabs instead of spaces to indent code.
No changes detected by objdiff.
Signed-off-by: Ian Morris <ipm@chirality.org.uk>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Stop hidding the sk parameter with an inline helper function and make
all of the callers pass it, so that it is clear what the function is
doing.
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Only pass the void *priv parameter out of the nf_hook_ops. That is
all any of the functions are interested now, and by limiting what is
passed it becomes simpler to change implementation details.
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Instead of saying "net = dev_net(state->in?state->in:state->out)"
just say "state->net". As that information is now availabe,
much less confusing and much less error prone.
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
bridge/netfilter/ebtables.c:290:26: warning: incorrect type in assignment (different modifiers)
-> remove __pure annotation.
ipv6/netfilter/ip6t_SYNPROXY.c:240:27: warning: cast from restricted __be16
-> switch ntohs to htons and vice versa.
netfilter/core.c:391:30: warning: symbol 'nfq_ct_nat_hook' was not declared. Should it be static?
-> delete it, got removed
net/netfilter/nf_synproxy_core.c:221:48: warning: cast to restricted __be32
-> Use __be32 instead of u32.
Tested with objdiff that these changes do not affect generated code.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Upon receipt of SYNACK from the server, ipt_SYNPROXY first sends back an ACK to
finish the server handshake, then calls nf_ct_seqadj_init() to initiate
sequence number adjustment of forwarded packets to the client and finally sends
a window update to the client to unblock it's TX queue.
Since synproxy_send_client_ack() does not set synproxy_send_tcp()'s nfct
parameter, no sequence number adjustment happens and the client receives the
window update with incorrect sequence number. Depending on client TCP
implementation, this leads to a significant delay (until a window probe is
being sent).
Signed-off-by: Phil Sutter <phil@nwl.cc>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This happens when networking namespaces are enabled.
Suggested-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: Phil Sutter <phil@nwl.cc>
Acked-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Fix a crash in synproxy_send_tcp() when using the SYNPROXY target in the
PREROUTING chain caused by missing routing information.
Reported-by: Nicki P. <xastx@gmx.de>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
When the synproxy_parse_options is called on the client ack the mss
option will not be present. Consequently mss wont be included in the
backend syn packet, which falls back to 536 bytes mss.
Therefore XT_SYNPROXY_OPT_MSS is explicitly flagged when recovering mss
value from cookie.
Signed-off-by: Martin Topholm <mph@one.com>
Reviewed-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Pass the hook ops to the hookfn to allow for generic hook
functions. This change is required by nf_tables.
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
TCP packets hitting the SYN proxy through the SYNPROXY target are not
validated by TCP conntrack. When th->doff is below 5, an underflow happens
when calculating the options length, causing skb_header_pointer() to
return NULL and triggering the BUG_ON().
Handle this case gracefully by checking for NULL instead of using BUG_ON().
Reported-by: Martin Topholm <mph@one.com>
Tested-by: Martin Topholm <mph@one.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Packets reaching SYNPROXY were default dropped, as they were most
likely invalid (given the recommended state matching). This
patch, changes SYNPROXY target to let packets, not consumed,
continue being processed by the stack.
This will be more in line other target modules. As it will allow
more flexible configurations of handling, logging or matching on
packets in INVALID states.
Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Acked-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Its seems Patrick missed to incoorporate some of my requested changes
during review v2 of SYNPROXY netfilter module.
Which were, to avoid SYN+ACK packets to enter the path, meant for the
ACK packet from the client (from the 3WHS).
Further there were a bug in ip6t_SYNPROXY.c, for matching SYN packets
that didn't exclude the ACK flag.
Go a step further with SYN packet/flag matching by excluding flags
ACK+FIN+RST, in both IPv4 and IPv6 modules.
The intented usage of SYNPROXY is as follows:
(gracefully describing usage in commit)
iptables -t raw -A PREROUTING -i eth0 -p tcp --dport 80 --syn -j NOTRACK
iptables -A INPUT -i eth0 -p tcp --dport 80 -m state UNTRACKED,INVALID \
-j SYNPROXY --sack-perm --timestamp --mss 1480 --wscale 7 --ecn
echo 0 > /proc/sys/net/netfilter/nf_conntrack_tcp_loose
This does filter SYN flags early, for packets in the UNTRACKED state,
but packets in the INVALID state with other TCP flags could still
reach the module, thus this stricter flag matching is still needed.
Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Acked-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Add an IPv6 version of the SYNPROXY target. The main differences to the
IPv4 version is routing and IP header construction.
Signed-off-by: Patrick McHardy <kaber@trash.net>
Tested-by: Martin Topholm <mph@one.com>
Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>