Connection tracking helpers (specifically FTP) need to be called
before NAT sequence numbers adjustments are performed to be able
to compare them against previously seen ones. We've introduced
two new hooks around 2.6.11 to maintain this ordering when NAT
modules were changed to get called from conntrack helpers directly.
The cost of netfilter hooks is quite high and sequence number
adjustments are only rarely needed however. Add a RCU-protected
sequence number adjustment function pointer and call it from
IPv4 conntrack after calling the helper.
Signed-off-by: Patrick McHardy <kaber@trash.net>
Adding extensions to confirmed conntracks is not allowed to avoid races
on reallocation. Don't setup NAT for confirmed conntracks in case NAT
module is loaded late.
The has one side-effect, the connections existing before the NAT module
was loaded won't enter the bysource hash. The only case where this actually
makes a difference is in case of SNAT to a multirange where the IP before
NAT is also part of the range. Since old connections don't enter the
bysource hash the first new connection from the IP will have a new address
selected. This shouldn't matter at all.
Signed-off-by: Patrick McHardy <kaber@trash.net>
Locally generated ICMP packets have a reference to the conntrack entry
of the original packet manually attached by icmp_send(). Therefore the
check for locally originated untracked ICMP redirects can never be
true.
Signed-off-by: Patrick McHardy <kaber@trash.net>
Move responsibility for setting the IP_NAT_RANGE_PROTO_SPECIFIED flag
to the NAT protocol, properly propagate errors and get rid of ugly
return value convention.
Signed-off-by: Patrick McHardy <kaber@trash.net>
Move to nf_nat_proto_common and rename to nf_nat_proto_... since they're
also used by protocols that don't have port numbers.
Signed-off-by: Patrick McHardy <kaber@trash.net>
The port rover should not get overwritten when using random mode,
otherwise other rules will also use more or less random ports.
Signed-off-by: Patrick McHardy <kaber@trash.net>
Rule dumping is performed in two steps: first userspace gets the
ruleset size using getsockopt(SO_GET_INFO) and allocates memory,
then it calls getsockopt(SO_GET_ENTRIES) to actually dump the
ruleset. When another process changes the ruleset in between the
sizes from the first getsockopt call doesn't match anymore and
the kernel aborts. Unfortunately it returns EAGAIN, as for multiple
other possible errors, so userspace can't distinguish this case
from real errors.
Return EAGAIN so userspace can retry the operation.
Fixes (with current iptables SVN version) netfilter bugzilla #104.
Signed-off-by: Patrick McHardy <kaber@trash.net>
Commit 9335f047fe aka
"[NETFILTER]: ip_tables: per-netns FILTER, MANGLE, RAW"
added per-netns _view_ of iptables rules. They were shown to user, but
ignored by filtering code. Now that it's possible to at least ping loopback,
per-netns tables can affect filtering decisions.
netns is taken in case of
PRE_ROUTING, LOCAL_IN -- from in device,
POST_ROUTING, LOCAL_OUT -- from out device,
FORWARD -- from in device which should be equal to out device's netns.
This code is relatively new, so BUG_ON was plugged.
Wrappers were added to a) keep code the same from CONFIG_NET_NS=n users
(overwhelming majority), b) consolidate code in one place -- similar
changes will be done in ipv6 and arp netfilter code.
Signed-off-by: Alexey Dobriyan <adobriyan@sw.ru>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Jan Engelhardt
Patrick McHardy
Robert P. J. Day
Alexey Dobriyan