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2022-08-22Remove DECnet support from kernelStephen Hemminger1-7/+0
DECnet is an obsolete network protocol that receives more attention from kernel janitors than users. It belongs in computer protocol history museum not in Linux kernel. It has been "Orphaned" in kernel since 2010. The iproute2 support for DECnet was dropped in 5.0 release. The documentation link on Sourceforge says it is abandoned there as well. Leave the UAPI alone to keep userspace programs compiling. This means that there is still an empty neighbour table for AF_DECNET. The table of /proc/sys/net entries was updated to match current directories and reformatted to be alphabetical. Signed-off-by: Stephen Hemminger <stephen@networkplumber.org> Acked-by: David Ahern <dsahern@kernel.org> Acked-by: Nikolay Aleksandrov <razor@blackwall.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-12-29net: Don't include filter.h from net/sock.hJakub Kicinski1-0/+1
sock.h is pretty heavily used (5k objects rebuilt on x86 after it's touched). We can drop the include of filter.h from it and add a forward declaration of struct sk_filter instead. This decreases the number of rebuilt objects when bpf.h is touched from ~5k to ~1k. There's a lot of missing includes this was masking. Primarily in networking tho, this time. Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Marc Kleine-Budde <mkl@pengutronix.de> Acked-by: Florian Fainelli <f.fainelli@gmail.com> Acked-by: Nikolay Aleksandrov <nikolay@nvidia.com> Acked-by: Stefano Garzarella <sgarzare@redhat.com> Link: https://lore.kernel.org/bpf/20211229004913.513372-1-kuba@kernel.org
2021-10-14netfilter: Introduce egress hookLukas Wunner1-4/+12
Support classifying packets with netfilter on egress to satisfy user requirements such as: * outbound security policies for containers (Laura) * filtering and mangling intra-node Direct Server Return (DSR) traffic on a load balancer (Laura) * filtering locally generated traffic coming in through AF_PACKET, such as local ARP traffic generated for clustering purposes or DHCP (Laura; the AF_PACKET plumbing is contained in a follow-up commit) * L2 filtering from ingress and egress for AVB (Audio Video Bridging) and gPTP with nftables (Pablo) * in the future: in-kernel NAT64/NAT46 (Pablo) The egress hook introduced herein complements the ingress hook added by commit e687ad60af09 ("netfilter: add netfilter ingress hook after handle_ing() under unique static key"). A patch for nftables to hook up egress rules from user space has been submitted separately, so users may immediately take advantage of the feature. Alternatively or in addition to netfilter, packets can be classified with traffic control (tc). On ingress, packets are classified first by tc, then by netfilter. On egress, the order is reversed for symmetry. Conceptually, tc and netfilter can be thought of as layers, with netfilter layered above tc. Traffic control is capable of redirecting packets to another interface (man 8 tc-mirred). E.g., an ingress packet may be redirected from the host namespace to a container via a veth connection: tc ingress (host) -> tc egress (veth host) -> tc ingress (veth container) In this case, netfilter egress classifying is not performed when leaving the host namespace! That's because the packet is still on the tc layer. If tc redirects the packet to a physical interface in the host namespace such that it leaves the system, the packet is never subjected to netfilter egress classifying. That is only logical since it hasn't passed through netfilter ingress classifying either. Packets can alternatively be redirected at the netfilter layer using nft fwd. Such a packet *is* subjected to netfilter egress classifying since it has reached the netfilter layer. Internally, the skb->nf_skip_egress flag controls whether netfilter is invoked on egress by __dev_queue_xmit(). Because __dev_queue_xmit() may be called recursively by tunnel drivers such as vxlan, the flag is reverted to false after sch_handle_egress(). This ensures that netfilter is applied both on the overlay and underlying network. Interaction between tc and netfilter is possible by setting and querying skb->mark. If netfilter egress classifying is not enabled on any interface, it is patched out of the data path by way of a static_key and doesn't make a performance difference that is discernible from noise: Before: 1537 1538 1538 1537 1538 1537 Mb/sec After: 1536 1534 1539 1539 1539 1540 Mb/sec Before + tc accept: 1418 1418 1418 1419 1419 1418 Mb/sec After + tc accept: 1419 1424 1418 1419 1422 1420 Mb/sec Before + tc drop: 1620 1619 1619 1619 1620 1620 Mb/sec After + tc drop: 1616 1624 1625 1624 1622 1619 Mb/sec When netfilter egress classifying is enabled on at least one interface, a minimal performance penalty is incurred for every egress packet, even if the interface it's transmitted over doesn't have any netfilter egress rules configured. That is caused by checking dev->nf_hooks_egress against NULL. Measurements were performed on a Core i7-3615QM. Commands to reproduce: ip link add dev foo type dummy ip link set dev foo up modprobe pktgen echo "add_device foo" > /proc/net/pktgen/kpktgend_3 samples/pktgen/pktgen_bench_xmit_mode_queue_xmit.sh -i foo -n 400000000 -m "11:11:11:11:11:11" -d 1.1.1.1 Accept all traffic with tc: tc qdisc add dev foo clsact tc filter add dev foo egress bpf da bytecode '1,6 0 0 0,' Drop all traffic with tc: tc qdisc add dev foo clsact tc filter add dev foo egress bpf da bytecode '1,6 0 0 2,' Apply this patch when measuring packet drops to avoid errors in dmesg: https://lore.kernel.org/netdev/a73dda33-57f4-95d8-ea51-ed483abd6a7a@iogearbox.net/ Signed-off-by: Lukas Wunner <lukas@wunner.de> Cc: Laura García Liébana <nevola@gmail.com> Cc: John Fastabend <john.fastabend@gmail.com> Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Eric Dumazet <edumazet@google.com> Cc: Thomas Graf <tgraf@suug.ch> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2021-08-06netfilter: nfnetlink_hook: translate inet ingress to netdevPablo Neira Ayuso1-1/+7
The NFPROTO_INET pseudofamily is not exposed through this new netlink interface. The netlink dump either shows NFPROTO_IPV4 or NFPROTO_IPV6 for NFPROTO_INET prerouting/input/forward/output/postrouting hooks. The NFNLA_CHAIN_FAMILY attribute provides the family chain, which specifies if this hook applies to inet traffic only (either IPv4 or IPv6). Translate the inet/ingress hook to netdev/ingress to fully hide the NFPROTO_INET implementation details. Fixes: e2cf17d3774c ("netfilter: add new hook nfnl subsystem") Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2021-08-06netfilter: nfnetlink_hook: Use same family as request messagePablo Neira Ayuso1-3/+3
Use the same family as the request message, for consistency. The netlink payload provides sufficient information to describe the hook object, including the family. This makes it easier to userspace to correlate the hooks are that visited by the packets for a certain family. Fixes: e2cf17d3774c ("netfilter: add new hook nfnl subsystem") Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2021-08-06netfilter: nfnetlink_hook: use the sequence number of the request messagePablo Neira Ayuso1-1/+2
The sequence number allows to correlate the netlink reply message (as part of the dump) with the original request message. The cb->seq field is internally used to detect an interference (update) of the hook list during the netlink dump, do not use it as sequence number in the netlink dump header. Fixes: e2cf17d3774c ("netfilter: add new hook nfnl subsystem") Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2021-08-06netfilter: nfnetlink_hook: missing chain familyPablo Neira Ayuso1-2/+6
The family is relevant for pseudo-families like NFPROTO_INET otherwise the user needs to rely on the hook function name to differentiate it from NFPROTO_IPV4 and NFPROTO_IPV6 names. Add nfnl_hook_chain_desc_attributes instead of using the existing NFTA_CHAIN_* attributes, since these do not provide a family number. Fixes: e2cf17d3774c ("netfilter: add new hook nfnl subsystem") Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2021-08-06netfilter: nfnetlink_hook: strip off module name from hookfnPablo Neira Ayuso1-0/+1
NFNLA_HOOK_FUNCTION_NAME should include the hook function name only, the module name is already provided by NFNLA_HOOK_MODULE_NAME. Fixes: e2cf17d3774c ("netfilter: add new hook nfnl subsystem") Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2021-07-23netfilter: nfnl_hook: fix unused variable warningArnd Bergmann1-0/+2
The only user of this variable is in an #ifdef: net/netfilter/nfnetlink_hook.c: In function 'nfnl_hook_entries_head': net/netfilter/nfnetlink_hook.c:177:28: error: unused variable 'netdev' [-Werror=unused-variable] Fixes: e2cf17d3774c ("netfilter: add new hook nfnl subsystem") Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2021-06-21netfilter: nfnetlink_hook: fix check for snprintf() overflowDan Carpenter1-1/+3
The kernel version of snprintf() can't return negatives. The "ret > (int)sizeof(sym)" check is off by one because and it should be >=. Finally, we need to set a negative error code. Fixes: e2cf17d3774c ("netfilter: add new hook nfnl subsystem") Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Reviewed-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2021-06-09netfilter: nfnetlink_hook: fix array index out-of-bounds errorColin Ian King1-1/+1
Currently the array net->nf.hooks_ipv6 is accessed by index hook before hook is sanity checked. Fix this by moving the sanity check to before the array access. Addresses-Coverity: ("Out-of-bounds access") Fixes: e2cf17d3774c ("netfilter: add new hook nfnl subsystem") Signed-off-by: Colin Ian King <colin.king@canonical.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2021-06-07netfilter: add new hook nfnl subsystemFlorian Westphal1-0/+375
This nfnl subsystem allows to dump the list of all active netfiler hooks, e.g. defrag, conntrack, nf/ip/arp/ip6tables and so on. This helps to see what kind of features are currently enabled in the network stack. Sample output from nft tool using this infra: $ nft list hook ip input family ip hook input { +0000000010 nft_do_chain_inet [nf_tables] # nft table firewalld INPUT +0000000100 nf_nat_ipv4_local_in [nf_nat] +2147483647 ipv4_confirm [nf_conntrack] } Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>