linux-dev/net/ipv6/netfilter, branch master

netfilter: rpfilter/fib: Set ->flowic_uid correctly for user namespaces.

2022-10-19T06:46:48Z

Currently netfilter's rpfilter and fib modules implicitely initialise ->flowic_uid with 0. This is normally the root UID. However, this isn't the case in user namespaces, where user ID 0 is mapped to a different kernel UID. By initialising ->flowic_uid with sock_net_uid(), we get the root UID of the user namespace, thus keeping the same behaviour whether or not we're running in a user namepspace. Note, this is similar to commit 8bcfd0925ef1 ("ipv4: add missing initialization for flowi4_uid"), which fixed the rp_filter sysctl. Fixes: 622ec2c9d524 ("net: core: add UID to flows, rules, and routes") Signed-off-by: Guillaume Nault Signed-off-by: Pablo Neira Ayuso

netfilter: rpfilter/fib: Populate flowic_l3mdev field

2022-10-12T12:08:15Z

Use the introduced field for correct operation with VRF devices instead of conditionally overwriting flowic_oif. This is a partial revert of commit b575b24b8eee3 ("netfilter: Fix rpfilter dropping vrf packets by mistake"), implementing a simpler solution. Signed-off-by: Phil Sutter Reviewed-by: David Ahern Reviewed-by: Guillaume Nault Signed-off-by: Florian Westphal

netfilter: nft_fib: Fix for rpath check with VRF devices

2022-09-28T11:33:26Z

Analogous to commit b575b24b8eee3 ("netfilter: Fix rpfilter dropping vrf packets by mistake") but for nftables fib expression: Add special treatment of VRF devices so that typical reverse path filtering via 'fib saddr . iif oif' expression works as expected. Fixes: f6d0cbcf09c50 ("netfilter: nf_tables: add fib expression") Signed-off-by: Phil Sutter Signed-off-by: Florian Westphal

tcp: Access &tcp_hashinfo via net.

2022-09-20T17:21:49Z

We will soon introduce an optional per-netns ehash. This means we cannot use tcp_hashinfo directly in most places. Instead, access it via net->ipv4.tcp_death_row.hashinfo. The access will be valid only while initialising tcp_hashinfo itself and creating/destroying each netns. Signed-off-by: Kuniyuki Iwashima Reviewed-by: Eric Dumazet Signed-off-by: Jakub Kicinski

netfilter: nf_defrag_ipv6: allow nf_conntrack_frag6_high_thresh increases

2022-08-24T06:06:44Z

Currently, net.netfilter.nf_conntrack_frag6_high_thresh can only be lowered. I found this issue while investigating a probable kernel issue causing flakes in tools/testing/selftests/net/ip_defrag.sh In particular, these sysctl changes were ignored: ip netns exec "${NETNS}" sysctl -w net.netfilter.nf_conntrack_frag6_high_thresh=9000000 >/dev/null 2>&1 ip netns exec "${NETNS}" sysctl -w net.netfilter.nf_conntrack_frag6_low_thresh=7000000 >/dev/null 2>&1 This change is inline with commit 836196239298 ("net/ipfrag: let ip[6]frag_high_thresh in ns be higher than in init_net") Fixes: 8db3d41569bb ("netfilter: nf_defrag_ipv6: use net_generic infra") Signed-off-by: Eric Dumazet Signed-off-by: Pablo Neira Ayuso

netfilter: conntrack: skip verification of zero UDP checksum

2022-05-13T16:56:28Z

The checksum is optional for UDP packets. However nf_reject would previously require a valid checksum to elicit a response such as ICMP_DEST_UNREACH. Add some logic to nf_reject_verify_csum to determine if a UDP packet has a zero checksum and should therefore not be verified. Signed-off-by: Kevin Mitchell Signed-off-by: Pablo Neira Ayuso

netfilter: nft_fib: reverse path filter for policy-based routing on iif

2022-04-11T10:10:09Z

If policy-based routing using the iif selector is used, then the fib expression fails to look up for the reverse path from the prerouting hook because the input interface cannot be inferred. In order to support this scenario, extend the fib expression to allow to use after the route lookup, from the forward hook. This patch also adds support for the input hook for usability reasons. Since the prerouting hook cannot be used for the scenario described above, users need two rules: one for the forward chain and another rule for the input chain to check for the reverse path check for locally targeted traffic. Acked-by: Florian Westphal Signed-off-by: Pablo Neira Ayuso

netfilter: nft_fib: add reduce support

2022-03-19T23:29:47Z

The fib expression stores to a register, so we can't add empty stub. Check that the register that is being written is in fact redundant. In most cases, this is expected to cancel tracking as re-use is unlikely. Signed-off-by: Florian Westphal Signed-off-by: Pablo Neira Ayuso

netfilter: nf_tables: do not reduce read-only expressions

2022-03-19T23:29:46Z

Skip register tracking for expressions that perform read-only operations on the registers. Define and use a cookie pointer NFT_REDUCE_READONLY to avoid defining stubs for these expressions. This patch re-enables register tracking which was disabled in ed5f85d42290 ("netfilter: nf_tables: disable register tracking"). Follow up patches add remaining register tracking for existing expressions. Signed-off-by: Pablo Neira Ayuso

net: ipv6: Handle delivery_time in ipv6 defrag

2022-03-03T14:38:48Z

A latter patch will postpone the delivery_time clearing until the stack knows the skb is being delivered locally (i.e. calling skb_clear_delivery_time() at ip_local_deliver_finish() for IPv4 and at ip6_input_finish() for IPv6). That will allow other kernel forwarding path (e.g. ip[6]_forward) to keep the delivery_time also. A very similar IPv6 defrag codes have been duplicated in multiple places: regular IPv6, nf_conntrack, and 6lowpan. Unlike the IPv4 defrag which is done before ip_local_deliver_finish(), the regular IPv6 defrag is done after ip6_input_finish(). Thus, no change should be needed in the regular IPv6 defrag logic because skb_clear_delivery_time() should have been called. 6lowpan also does not need special handling on delivery_time because it is a non-inet packet_type. However, cf_conntrack has a case in NF_INET_PRE_ROUTING that needs to do the IPv6 defrag earlier. Thus, it needs to save the mono_delivery_time bit in the inet_frag_queue which is similar to how it is handled in the previous patch for the IPv4 defrag. This patch chooses to do it consistently and stores the mono_delivery_time in the inet_frag_queue for all cases such that it will be easier for the future refactoring effort on the IPv6 reasm code. Signed-off-by: Martin KaFai Lau Signed-off-by: David S. Miller