- 08 Jan, 2018 40 commits
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Florian Westphal authored
The netfilter NAT core cannot deal with more than one NAT hook per hook location (prerouting, input ...), because the NAT hooks install a NAT null binding in case the iptables nat table (iptable_nat hooks) or the corresponding nftables chain (nft nat hooks) doesn't specify a nat transformation. Null bindings are needed to detect port collsisions between NAT-ed and non-NAT-ed connections. This causes nftables NAT rules to not work when iptable_nat module is loaded, and vice versa because nat binding has already been attached when the second nat hook is consulted. The netfilter core is not really the correct location to handle this (hooks are just hooks, the core has no notion of what kinds of side effects a hook implements), but its the only place where we can check for conflicts between both iptables hooks and nftables hooks without adding dependencies. So add nat annotation to hook_ops to describe those hooks that will add NAT bindings and then make core reject if such a hook already exists. The annotation fills a padding hole, in case further restrictions appar we might change this to a 'u8 type' instead of bool. iptables error if nft nat hook active: iptables -t nat -A POSTROUTING -j MASQUERADE iptables v1.4.21: can't initialize iptables table `nat': File exists Perhaps iptables or your kernel needs to be upgraded. nftables error if iptables nat table present: nft -f /etc/nftables/ipv4-nat /usr/etc/nftables/ipv4-nat:3:1-2: Error: Could not process rule: File exists table nat { ^^ Signed-off-by:Florian Westphal <fw@strlen.de> Signed-off-by:
Pablo Neira Ayuso <pablo@netfilter.org>
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Florian Westphal authored
currently we always return -ENOENT to userspace if we can't find a particular table, or if the table initialization fails. Followup patch will make nat table init fail in case nftables already registered a nat hook so this change makes xt_find_table_lock return an ERR_PTR to return the errno value reported from the table init function. Add xt_request_find_table_lock as try_then_request_module replacement and use it where needed. Signed-off-by:
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Florian Westphal authored
This can be same as NF_INET_NUMHOOKS if we don't support DECNET. Signed-off-by:
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Florian Westphal authored
no need to define hook points if the family isn't supported. Because we need these hooks for either nftables, arp/ebtables or the 'call-iptables' hack we have in the bridge layer add two new dependencies, NETFILTER_FAMILY_{ARP,BRIDGE}, and have the users select them. Signed-off-by: -
Florian Westphal authored
no need to define hook points if the family isn't supported. Signed-off-by:
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Florian Westphal authored
Not all families share the same hook count, adjust sizes to what is needed. struct net before: /* size: 6592, cachelines: 103, members: 46 */ after: /* size: 5952, cachelines: 93, members: 46 */ Signed-off-by:
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Florian Westphal authored
The kernel already has defines for this, but they are in uapi exposed headers. Including these from netns.h causes build errors and also adds unneeded dependencies on heads that we don't need. So move these defines to netfilter_defs.h and place the uapi ones in ifndef __KERNEL__ to keep them for userspace. Signed-off-by:
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Florian Westphal authored
struct net contains: struct nf_hook_entries __rcu *hooks[NFPROTO_NUMPROTO][NF_MAX_HOOKS]; which store the hook entry point locations for the various protocol families and the hooks. Using array results in compact c code when doing accesses, i.e. x = rcu_dereference(net->nf.hooks[pf][hook]); but its also wasting a lot of memory, as most families are not used. So split the array into those families that are used, which are only 5 (instead of 13). In most cases, the 'pf' argument is constant, i.e. gcc removes switch statement. struct net before: /* size: 5184, cachelines: 81, members: 46 */ after: /* size: 4672, cachelines: 73, members: 46 */ Signed-off-by:
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Florian Westphal authored
Giuseppe Scrivano says: "SELinux, if enabled, registers for each new network namespace 6 netfilter hooks." Cost for this is high. With synchronize_net() removed: "The net benefit on an SMP machine with two cores is that creating a new network namespace takes -40% of the original time." This patch replaces synchronize_net+kvfree with call_rcu(). We store rcu_head at the tail of a structure that has no fixed layout, i.e. we cannot use offsetof() to compute the start of the original allocation. Thus store this information right after the rcu head. We could simplify this by just placing the rcu_head at the start of struct nf_hook_entries. However, this structure is used in packet processing hotpath, so only place what is needed for that at the beginning of the struct. Reported-by:Giuseppe Scrivano <gscrivan@redhat.com> Signed-off-by:
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Florian Westphal authored
since commit 960632ec ("netfilter: convert hook list to an array") nfqueue no longer stores a pointer to the hook that caused the packet to be queued. Therefore no extra synchronize_net() call is needed after dropping the packets enqueued by the old rule blob. Signed-off-by:
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Florian Westphal authored
This reverts commit d3ad2c17 ("netfilter: core: batch nf_unregister_net_hooks synchronize_net calls"). Nothing wrong with it. However, followup patch will delay freeing of hooks with call_rcu, so all synchronize_net() calls become obsolete and there is no need anymore for this batching. This revert causes a temporary performance degradation when destroying network namespace, but its resolved with the upcoming call_rcu conversion. Signed-off-by:
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Varsha Rao authored
Change old multi-line comment style to kernel comment style and remove unwanted comments. Signed-off-by:
Varsha Rao <rvarsha016@gmail.com> Signed-off-by:
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Florian Westphal authored
When sets are extremely large we can get softlockup during ipset -L. We could fix this by adding cond_resched_rcu() at the right location during iteration, but this only works if RCU nesting depth is 1. At this time entire variant->list() is called under under rcu_read_lock_bh. This used to be a read_lock_bh() but as rcu doesn't really lock anything, it does not appear to be needed, so remove it (ipset increments set reference count before this, so a set deletion should not be possible). Reported-by:
Li Shuang <shuali@redhat.com> Signed-off-by:
Jozsef Kadlecsik <kadlec@blackhole.kfki.hu> Signed-off-by:
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Florian Westphal authored
Check that we really hold nfnl mutex here instead of relying on correct usage alone. Signed-off-by:
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Gao Feng authored
The param of frag_safe_skb_hp, ipvsh, isn't used now. So remove it and update the callers' codes too. Signed-off-by:
Gao Feng <gfree.wind@vip.163.com> Acked-by:
Simon Horman <horms+renesas@verge.net.au> Signed-off-by:
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Florian Westphal authored
Nowadays this is just the default template that is used when setting up the net namespace, so nothing writes to these locations. Signed-off-by:
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Gustavo A. R. Silva authored
In preparation to enabling -Wimplicit-fallthrough, mark switch cases where we are expecting to fall through. Signed-off-by:
Gustavo A. R. Silva <garsilva@embeddedor.com> Signed-off-by:
Simon Horman <horms@verge.net.au> Signed-off-by:
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Florian Westphal authored
previous patches removed all writes to these structs so we can now mark them as const. Signed-off-by:
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Florian Westphal authored
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Florian Westphal authored
similar to previous commit, but instead compute this at compile time and turn nlattr_size into an u16. Signed-off-by:
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David S. Miller authored
Ido Schimmel says: ==================== ipv6: Align nexthop behaviour with IPv4 This set tries to eliminate some differences between IPv4's and IPv6's treatment of nexthops. These differences are most likely a side effect of IPv6's data structures (specifically 'rt6_info') that incorporate both the route and the nexthop and the late addition of ECMP support in commit 51ebd318 ("ipv6: add support of equal cost multipath (ECMP)"). IPv4 and IPv6 do not react the same to certain netdev events. For example, upon carrier change affected IPv4 nexthops are marked using the RTNH_F_LINKDOWN flag and the nexthop group is rebalanced accordingly. IPv6 on the other hand, does nothing which forces us to perform a carrier check during route lookup and dump. This makes it difficult to introduce features such as non-equal-cost multipath that are built on top of this set [1]. In addition, when a netdev is put administratively down IPv4 nexthops are marked using the RTNH_F_DEAD flag, whereas IPv6 simply flushes all the routes using these nexthops. To be consistent with IPv4, multipath routes should only be flushed when all nexthops in the group are considered dead. The first 12 patches introduce non-functional changes that store the RTNH_F_DEAD and RTNH_F_LINKDOWN flags in IPv6 routes based on netdev events, in a similar fashion to IPv4. This allows us to remove the carrier check performed during route lookup and dump. The next three patches make sure we only flush a multipath route when all of its nexthops are dead. Last three patches add test cases for IPv4/IPv6 FIB. These verify that both address families react similarly to netdev events. Finally, this series also serves as a good first step towards David Ahern's goal of treating nexthops as standalone objects [2], as it makes the code more in line with IPv4 where the nexthop and the nexthop group are separate objects from the route itself. 1. https://github.com/idosch/linux/tree/ipv6-nexthops 2. http://vger.kernel.org/netconf2017_files/nexthop-objects.pdf Changes since RFC (feedback from David Ahern): * Remove redundant declaration of rt6_ifdown() in patch 4 and adjust comment referencing it accordingly * Drop patch to flush multipath routes upon NETDEV_UNREGISTER. Reword cover letter accordingly * Use a temporary variable to make code more readable in patch 15 ==================== Signed-off-by:
David S. Miller <davem@davemloft.net>
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Ido Schimmel authored
Check that IPv4 and IPv6 react the same when the carrier of a netdev is toggled. Local routes should not be affected by this, whereas unicast routes should. Signed-off-by:
Ido Schimmel <idosch@mellanox.com> Acked-by:
David Ahern <dsahern@gmail.com> Signed-off-by:
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Ido Schimmel authored
Check that IPv4 and IPv6 react the same when a netdev is being put administratively down. Signed-off-by:
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Ido Schimmel authored
Add test cases to check that IPv4 and IPv6 react to a netdev being unregistered as expected. Signed-off-by:
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Ido Schimmel authored
By default, IPv6 deletes nexthops from a multipath route when the nexthop device is put administratively down. This differs from IPv4 where the nexthops are kept, but marked with the RTNH_F_DEAD flag. A multipath route is flushed when all of its nexthops become dead. Align IPv6 with IPv4 and have it conform to the same guidelines. In case the multipath route needs to be flushed, its siblings are flushed one by one. Otherwise, the nexthops are marked with the appropriate flags and the tree walker is instructed to skip all the siblings. As explained in previous patches, care is taken to update the sernum of the affected tree nodes, so as to prevent the use of wrong dst entries. Signed-off-by:
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Ido Schimmel authored
The next patch is going to allow dead routes to remain in the FIB tree in certain situations. When this happens we need to be sure to bump the sernum of the nodes where these are stored so that potential copies cached in sockets are invalidated. The function that performs this update assumes the table lock is not taken when it is invoked, but that will not be the case when it is invoked by the tree walker. Have the function assume the lock is taken and make the single caller take the lock itself. Signed-off-by:
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Ido Schimmel authored
We are going to allow dead routes to stay in the FIB tree (e.g., when they are part of a multipath route, directly connected route with no carrier) and revive them when their nexthop device gains carrier or when it is put administratively up. This is equivalent to the addition of the route to the FIB tree and we should therefore take care of updating the sernum of all the parent nodes of the node where the route is stored. Otherwise, we risk sockets caching and using sub-optimal dst entries. Export the function that performs the above, so that it could be invoked from fib6_ifup() later on. Signed-off-by:
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Ido Schimmel authored
As explained in previous patch, fib6_ifdown() needs to consider the state of all the sibling routes when a multipath route is traversed. This is done by evaluating all the siblings when the first sibling in a multipath route is traversed. If the multipath route does not need to be flushed (e.g., not all siblings are dead), then we should just skip the multipath route as our work is done. Have the tree walker jump to the last sibling when it is determined that the multipath route needs to be skipped. Signed-off-by:
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Ido Schimmel authored
When routes that are a part of a multipath route are evaluated by fib6_ifdown() in response to NETDEV_DOWN and NETDEV_UNREGISTER events the state of their sibling routes is not considered. This will change in subsequent patches in order to align IPv6 with IPv4's behavior. For example, when the last sibling in a multipath route becomes dead, the entire multipath route needs to be removed. To prevent the tree walker from re-evaluating all the sibling routes each time, we can simply evaluate them once - when the first sibling is traversed. If we determine the entire multipath route needs to be removed, then the 'should_flush' bit is set in all the siblings, which will cause the walker to flush them when it traverses them. Signed-off-by:
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Ido Schimmel authored
Up until now the RTNH_F_DEAD flag was only reported in route dump when the 'ignore_routes_with_linkdown' sysctl was set. This is expected as dead routes were flushed otherwise. The reliance on this sysctl is going to be removed, so we need to report the flag regardless of the sysctl's value. Signed-off-by:
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Ido Schimmel authored
Currently, dead routes are only present in the routing tables in case the 'ignore_routes_with_linkdown' sysctl is set. Otherwise, they are flushed. Subsequent patches are going to remove the reliance on this sysctl and make IPv6 more consistent with IPv4. Before this is done, we need to make sure dead routes are skipped during route lookup, so as to not cause packet loss. Signed-off-by:
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Ido Schimmel authored
Similar to previous patch, there is no need to check for the carrier of the nexthop device when dumping the route and we can instead check for the presence of the RTNH_F_LINKDOWN flag. Signed-off-by:
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Ido Schimmel authored
Now that the RTNH_F_LINKDOWN flag is set in nexthops, we can avoid the need to dereference the nexthop device and check its carrier and instead check for the presence of the flag. Signed-off-by:
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Ido Schimmel authored
It is valid to install routes with a nexthop device that does not have a carrier, so we need to make sure they're marked accordingly. As explained in the previous patch, host and anycast routes are never marked with the 'linkdown' flag. Note that reject routes are unaffected, as these use the loopback device which always has a carrier. Signed-off-by:
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Ido Schimmel authored
Similar to IPv4, when the carrier of a netdev changes we should toggle the 'linkdown' flag on all the nexthops using it as their nexthop device. This will later allow us to test for the presence of this flag during route lookup and dump. Up until commit 4832c30d ("net: ipv6: put host and anycast routes on device with address") host and anycast routes used the loopback netdev as their nexthop device and thus were not marked with the 'linkdown' flag. The patch preserves this behavior and allows one to ping the local address even when the nexthop device does not have a carrier and the 'ignore_routes_with_linkdown' sysctl is set. Signed-off-by:
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Ido Schimmel authored
To make IPv6 more in line with IPv4 we need to be able to respond differently to different netdev events. For example, when a netdev is unregistered all the routes using it as their nexthop device should be flushed, whereas when the netdev's carrier changes only the 'linkdown' flag should be toggled. Currently, this is not possible, as the function that traverses the routing tables is not aware of the triggering event. Propagate the triggering event down, so that it could be used in later patches. Signed-off-by:
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Ido Schimmel authored
Previous patch marked nexthops with the 'dead' and 'linkdown' flags. Clear these flags when the netdev comes back up. Signed-off-by:
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Ido Schimmel authored
When a netdev is put administratively down or unregistered all the nexthops using it as their nexthop device should be marked with the 'dead' and 'linkdown' flags. Currently, when a route is dumped its nexthop device is tested and the flags are set accordingly. A similar check is performed during route lookup. Instead, we can simply mark the nexthops based on netdev events and avoid checking the netdev's state during route dump and lookup. Signed-off-by:
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Ido Schimmel authored
By the time fib6_net_exit() is executed all the netdevs in the namespace have been either unregistered or pushed back to the default namespace. That is because pernet subsys operations are always ordered before pernet device operations and therefore invoked after them during namespace dismantle. Thus, all the routing tables in the namespace are empty by the time fib6_net_exit() is invoked and the call to rt6_ifdown() can be removed. This allows us to simplify the condition in fib6_ifdown() as it's only ever called with an actual netdev. Signed-off-by:
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git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-nextDavid S. Miller authored
Daniel Borkmann says: ==================== pull-request: bpf-next 2018-01-07 The following pull-request contains BPF updates for your *net-next* tree. The main changes are: 1) Add a start of a framework for extending struct xdp_buff without having the overhead of populating every data at runtime. Idea is to have a new per-queue struct xdp_rxq_info that holds read mostly data (currently that is, queue number and a pointer to the corresponding netdev) which is set up during rxqueue config time. When a XDP program is invoked, struct xdp_buff holds a pointer to struct xdp_rxq_info that the BPF program can then walk. The user facing BPF program that uses struct xdp_md for context can use these members directly, and the verifier rewrites context access transparently by walking the xdp_rxq_info and net_device pointers to load the data, from Jesper. 2) Redo the reporting of offload device information to user space such that it works in combination with network namespaces. The latter is reported through a device/inode tuple as similarly done in other subsystems as well (e.g. perf) in order to identify the namespace. For this to work, ns_get_path() has been generalized such that the namespace can be retrieved not only from a specific task (perf case), but also from a callback where we deduce the netns (ns_common) from a netdevice. bpftool support using the new uapi info and extensive test cases for test_offload.py in BPF selftests have been added as well, from Jakub. 3) Add two bpftool improvements: i) properly report the bpftool version such that it corresponds to the version from the kernel source tree. So pick the right linux/version.h from the source tree instead of the installed one. ii) fix bpftool and also bpf_jit_disasm build with bintutils >= 2.9. The reason for the build breakage is that binutils library changed the function signature to select the disassembler. Given this is needed in multiple tools, add a proper feature detection to the tools/build/features infrastructure, from Roman. 4) Implement the BPF syscall command BPF_MAP_GET_NEXT_KEY for the stacktrace map. It is currently unimplemented, but there are use cases where user space needs to walk all stacktrace map entries e.g. for dumping or deleting map entries w/o having to close and recreate the map. Add BPF selftests along with it, from Yonghong. 5) Few follow-up cleanups for the bpftool cgroup code: i) rename the cgroup 'list' command into 'show' as we have it for other subcommands as well, ii) then alias the 'show' command such that 'list' is accepted which is also common practice in iproute2, and iii) remove couple of newlines from error messages using p_err(), from Jakub. 6) Two follow-up cleanups to sockmap code: i) remove the unused bpf_compute_data_end_sk_skb() function and ii) only build the sockmap infrastructure when CONFIG_INET is enabled since it's only aware of TCP sockets at this time, from John. ==================== Signed-off-by:
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