pm24.git/include/uapi/linux/netfilter, branch v4.1

conntrack: RFC5961 challenge ACK confuse conntrack LAST-ACK transition

2015-05-15T18:50:56Z

In compliance with RFC5961, the network stack send challenge ACK in response to spurious SYN packets, since commit 0c228e833c88 ("tcp: Restore RFC5961-compliant behavior for SYN packets"). This pose a problem for netfilter conntrack in state LAST_ACK, because this challenge ACK is (falsely) seen as ACKing last FIN, causing a false state transition (into TIME_WAIT). The challenge ACK is hard to distinguish from real last ACK. Thus, solution introduce a flag that tracks the potential for seeing a challenge ACK, in case a SYN packet is let through and current state is LAST_ACK. When conntrack transition LAST_ACK to TIME_WAIT happens, this flag is used for determining if we are expecting a challenge ACK. Scapy based reproducer script avail here: https://github.com/netoptimizer/network-testing/blob/master/scapy/tcp_hacks_3WHS_LAST_ACK.py Fixes: 0c228e833c88 ("tcp: Restore RFC5961-compliant behavior for SYN packets") Signed-off-by: Jesper Dangaard Brouer Acked-by: Jozsef Kadlecsik Signed-off-by: Pablo Neira Ayuso

netfilter: nft_dynset: dynamic stateful expression instantiation

2015-04-13T18:19:55Z

Support instantiating stateful expressions based on a template that are associated with dynamically created set entries. The expressions are evaluated when adding or updating the set element. This allows to maintain per flow state using the existing set infrastructure and expression types, with arbitrary definitions of a flow. Usage is currently restricted to anonymous sets, meaning only a single binding can exist, since the desired semantics of multiple independant bindings haven't been defined so far. Examples (userspace syntax is still WIP): 1. Limit the rate of new SSH connections per host, similar to iptables hashlimit: flow ip saddr timeout 60s \ limit 10/second \ accept 2. Account network traffic between each set of /24 networks: flow ip saddr & 255.255.255.0 . ip daddr & 255.255.255.0 \ counter 3. Account traffic to each host per user: flow skuid . ip daddr \ counter 4. Account traffic for each combination of source address and TCP flags: flow ip saddr . tcp flags \ counter The resulting set content after a Xmas-scan look like this: { 192.168.122.1 . fin | psh | urg : counter packets 1001 bytes 40040, 192.168.122.1 . ack : counter packets 74 bytes 3848, 192.168.122.1 . psh | ack : counter packets 35 bytes 3144 } Signed-off-by: Patrick McHardy Signed-off-by: Pablo Neira Ayuso

netfilter: nf_tables: add flag to indicate set contains expressions

2015-04-13T18:12:32Z

Add a set flag to indicate that the set is used as a state table and contains expressions for evaluation. This operation is mutually exclusive with the mapping operation, so sets specifying both are rejected. The lookup expression also rejects binding to state tables since it only deals with loopup and map operations. Signed-off-by: Patrick McHardy Signed-off-by: Pablo Neira Ayuso

netfilter: nf_tables: prepare for expressions associated to set elements

2015-04-13T18:12:31Z

Preparation to attach expressions to set elements: add a set extension type to hold an expression and dump the expression information with the set element. Signed-off-by: Patrick McHardy Signed-off-by: Pablo Neira Ayuso

netfilter: nf_tables: variable sized set element keys / data

2015-04-13T15:17:31Z

This patch changes sets to support variable sized set element keys / data up to 64 bytes each by using variable sized set extensions. This allows to use concatenations with bigger data items suchs as IPv6 addresses. As a side effect, small keys/data now don't require the full 16 bytes of struct nft_data anymore but just the space they need. Signed-off-by: Patrick McHardy Signed-off-by: Pablo Neira Ayuso

netfilter: nf_tables: switch registers to 32 bit addressing

2015-04-13T15:17:29Z

Switch the nf_tables registers from 128 bit addressing to 32 bit addressing to support so called concatenations, where multiple values can be concatenated over multiple registers for O(1) exact matches of multiple dimensions using sets. The old register values are mapped to areas of 128 bits for compatibility. When dumping register numbers, values are expressed using the old values if they refer to the beginning of a 128 bit area for compatibility. To support concatenations, register loads of less than a full 32 bit value need to be padded. This mainly affects the payload and exthdr expressions, which both unconditionally zero the last word before copying the data. Userspace fully passes the testsuite using both old and new register addressing. Signed-off-by: Patrick McHardy Signed-off-by: Pablo Neira Ayuso

netfilter: nf_tables: support optional userdata for set elements

2015-04-08T14:58:27Z

Add an userdata set extension and allow the user to attach arbitrary data to set elements. This is intended to hold TLV encoded data like comments or DNS annotations that have no meaning to the kernel. Signed-off-by: Patrick McHardy Signed-off-by: Pablo Neira Ayuso

netfilter: nf_tables: add support for dynamic set updates

2015-04-08T14:58:27Z

Add a new "dynset" expression for dynamic set updates. A new set op ->update() is added which, for non existant elements, invokes an initialization callback and inserts the new element. For both new or existing elements the extenstion pointer is returned to the caller to optionally perform timer updates or other actions. Element removal is not supported so far, however that seems to be a rather exotic need and can be added later on. Signed-off-by: Patrick McHardy Signed-off-by: Pablo Neira Ayuso

netfilter: nf_tables: add set element timeout support

2015-04-01T09:17:28Z

Add API support for set element timeouts. Elements can have a individual timeout value specified, overriding the sets' default. Two new extension types are used for timeouts - the timeout value and the expiration time. The timeout value only exists if it differs from the default value. Signed-off-by: Patrick McHardy Signed-off-by: Pablo Neira Ayuso

netfilter: nf_tables: add set timeout API support

2015-04-01T09:17:28Z

Add set timeout support to the netlink API. Sets with timeout support enabled can have a default timeout value and garbage collection interval specified. Signed-off-by: Patrick McHardy Signed-off-by: Pablo Neira Ayuso