kernel/linux.git/include/net/netns/ipv4.h, branch v5.15.89

ipv4/tcp: do not use per netns ctl sockets

2022-07-29T15:25:11+00:00

[ Upstream commit 37ba017dcc3b1123206808979834655ddcf93251 ] TCP ipv4 uses per-cpu/per-netns ctl sockets in order to send RST and some ACK packets (on behalf of TIMEWAIT sockets). This adds memory and cpu costs, which do not seem needed. Now typical servers have 256 or more cores, this adds considerable tax to netns users. tcp sockets are used from BH context, are not receiving packets, and do not store any persistent state but the 'struct net' pointer in order to be able to use IPv4 output functions. Note that I attempted a related change in the past, that had to be hot-fixed in commit bdbbb8527b6f ("ipv4: tcp: get rid of ugly unicast_sock") This patch could very well surface old bugs, on layers not taking care of sk->sk_kern_sock properly. Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller Signed-off-by: Sasha Levin

ipv4: convert fib_num_tclassid_users to atomic_t

2021-12-08T08:04:49+00:00

commit 213f5f8f31f10aa1e83187ae20fb7fa4e626b724 upstream. Before commit faa041a40b9f ("ipv4: Create cleanup helper for fib_nh") changes to net->ipv4.fib_num_tclassid_users were protected by RTNL. After the change, this is no longer the case, as free_fib_info_rcu() runs after rcu grace period, without rtnl being held. Fixes: faa041a40b9f ("ipv4: Create cleanup helper for fib_nh") Signed-off-by: Eric Dumazet Cc: David Ahern Reviewed-by: David Ahern Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

net/tcp_fastopen: remove tcp_fastopen_ctx_lock

2021-07-20T10:07:07+00:00

Remove the (per netns) spinlock in favor of xchg() atomic operations. Signed-off-by: Eric Dumazet Cc: Yuchung Cheng Cc: Neal Cardwell Acked-by: Wei Wang Link: https://lore.kernel.org/r/20210719101107.3203943-1-eric.dumazet@gmail.com Signed-off-by: Jakub Kicinski

net: Introduce net.ipv4.tcp_migrate_req.

2021-06-15T16:01:05+00:00

This commit adds a new sysctl option: net.ipv4.tcp_migrate_req. If this option is enabled or eBPF program is attached, we will be able to migrate child sockets from a listener to another in the same reuseport group after close() or shutdown() syscalls. Signed-off-by: Kuniyuki Iwashima Signed-off-by: Daniel Borkmann Reviewed-by: Benjamin Herrenschmidt Reviewed-by: Eric Dumazet Acked-by: Martin KaFai Lau Link: https://lore.kernel.org/bpf/20210612123224.12525-2-kuniyu@amazon.co.jp

ipv4: Add a sysctl to control multipath hash fields

2021-05-18T20:27:32+00:00

A subsequent patch will add a new multipath hash policy where the packet fields used for multipath hash calculation are determined by user space. This patch adds a sysctl that allows user space to set these fields. The packet fields are represented using a bitmask and are common between IPv4 and IPv6 to allow user space to use the same numbering across both protocols. For example, to hash based on standard 5-tuple: # sysctl -w net.ipv4.fib_multipath_hash_fields=0x0037 net.ipv4.fib_multipath_hash_fields = 0x0037 The kernel rejects unknown fields, for example: # sysctl -w net.ipv4.fib_multipath_hash_fields=0x1000 sysctl: setting key "net.ipv4.fib_multipath_hash_fields": Invalid argument More fields can be added in the future, if needed. Signed-off-by: Ido Schimmel Reviewed-by: David Ahern Signed-off-by: David S. Miller

netfilter: remove all xt_table anchors from struct net

2021-04-26T01:20:47+00:00

No longer needed, table pointer arg is now passed via netfilter core. Signed-off-by: Florian Westphal Signed-off-by: Pablo Neira Ayuso

tcp: convert tcp_comp_sack_nr sysctl to u8

2021-03-31T21:48:20+00:00

tcp_comp_sack_nr max value was already 255. Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller

ipv4: convert igmp_link_local_mcast_reports sysctl to u8

2021-03-31T21:48:20+00:00

This sysctl is a bool, can use less storage. Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller

ipv4: convert fib_multipath_{use_neigh|hash_policy} sysctls to u8

2021-03-31T21:48:20+00:00

Make room for better packing of netns_ipv4 Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller

ipv4: convert udp_l3mdev_accept sysctl to u8

2021-03-31T21:48:20+00:00

Reduce footprint of sysctls. Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller