linux/net/ipv4
Cong Wang 856c395cfa net: introduce a knob to control whether to inherit devconf config
There have been many people complaining about the inconsistent
behaviors of IPv4 and IPv6 devconf when creating new network
namespaces.  Currently, for IPv4, we inherit all current settings
from init_net, but for IPv6 we reset all setting to default.

This patch introduces a new /proc file
/proc/sys/net/core/devconf_inherit_init_net to control the
behavior of whether to inhert sysctl current settings from init_net.
This file itself is only available in init_net.

As demonstrated below:

Initial setup in init_net:
 # cat /proc/sys/net/ipv4/conf/all/rp_filter
 2
 # cat /proc/sys/net/ipv6/conf/all/accept_dad
 1

Default value 0 (current behavior):
 # ip netns del test
 # ip netns add test
 # ip netns exec test cat /proc/sys/net/ipv4/conf/all/rp_filter
 2
 # ip netns exec test cat /proc/sys/net/ipv6/conf/all/accept_dad
 0

Set to 1 (inherit from init_net):
 # echo 1 > /proc/sys/net/core/devconf_inherit_init_net
 # ip netns del test
 # ip netns add test
 # ip netns exec test cat /proc/sys/net/ipv4/conf/all/rp_filter
 2
 # ip netns exec test cat /proc/sys/net/ipv6/conf/all/accept_dad
 1

Set to 2 (reset to default):
 # echo 2 > /proc/sys/net/core/devconf_inherit_init_net
 # ip netns del test
 # ip netns add test
 # ip netns exec test cat /proc/sys/net/ipv4/conf/all/rp_filter
 0
 # ip netns exec test cat /proc/sys/net/ipv6/conf/all/accept_dad
 0

Set to a value out of range (invalid):
 # echo 3 > /proc/sys/net/core/devconf_inherit_init_net
 -bash: echo: write error: Invalid argument
 # echo -1 > /proc/sys/net/core/devconf_inherit_init_net
 -bash: echo: write error: Invalid argument

Reported-by: Zhu Yanjun <Yanjun.Zhu@windriver.com>
Reported-by: Tonghao Zhang <xiangxia.m.yue@gmail.com>
Cc: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Acked-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Acked-by: Tonghao Zhang <xiangxia.m.yue@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-01-22 11:07:21 -08:00
..
bpfilter net: bpfilter: disallow to remove bpfilter module while being used 2019-01-11 18:05:41 -08:00
netfilter Merge git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf-next 2018-12-20 18:20:26 -08:00
af_inet.c net: use indirect call wrappers at GRO transport layer 2018-12-15 13:23:02 -08:00
ah4.c net-ipv4: remove 2 always zero parameters from ipv4_redirect() 2018-09-26 20:30:55 -07:00
arp.c net: Evict neighbor entries on carrier down 2018-10-12 09:47:39 -07:00
cipso_ipv4.c net/ipv4: defensive cipso option parsing 2018-09-17 19:37:46 -07:00
datagram.c ipv4: Allow sending multicast packets on specific i/f using VRF socket 2018-10-02 22:28:17 -07:00
devinet.c net: introduce a knob to control whether to inherit devconf config 2019-01-22 11:07:21 -08:00
esp4_offload.c net: use skb_sec_path helper in more places 2018-12-19 11:21:37 -08:00
esp4.c net: use skb_sec_path helper in more places 2018-12-19 11:21:37 -08:00
fib_frontend.c net: ipv4: Fix memory leak in network namespace dismantle 2019-01-15 13:33:44 -08:00
fib_lookup.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
fib_notifier.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
fib_rules.c ipv4: fib_rules: Fix possible infinite loop in fib_empty_table 2018-12-30 12:57:04 -08:00
fib_semantics.c net: Add extack argument to ip_fib_metrics_init 2018-11-06 15:00:45 -08:00
fib_trie.c net: ipv4: Fix memory leak in network namespace dismantle 2019-01-15 13:33:44 -08:00
fou.c fou, fou6: do not assume linear skbs 2019-01-15 22:01:31 -08:00
gre_demux.c net: Convert protocol error handlers from void to int 2018-11-08 17:13:08 -08:00
gre_offload.c Merge ra.kernel.org:/pub/scm/linux/kernel/git/davem/net 2018-07-03 10:29:26 +09:00
icmp.c net: Convert protocol error handlers from void to int 2018-11-08 17:13:08 -08:00
igmp.c ipv4/igmp: fix v1/v2 switchback timeout based on rfc3376, 8.12 2018-10-29 20:26:06 -07:00
inet_connection_sock.c inet: minor optimization for backlog setting in listen(2) 2018-11-07 22:31:07 -08:00
inet_diag.c tcp: fix a race in inet_diag_dump_icsk() 2018-12-20 19:23:22 -08:00
inet_fragment.c inet: frags: better deal with smp races 2018-11-08 18:40:30 -08:00
inet_hashtables.c net: dccp: fix kernel crash on module load 2018-12-24 15:27:56 -08:00
inet_timewait_sock.c soreuseport: initialise timewait reuseport field 2018-04-07 22:32:32 -04:00
inetpeer.c inetpeer: fix uninit-value in inet_getpeer 2018-04-09 10:57:35 -04:00
ip_forward.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2018-12-20 11:53:36 -08:00
ip_fragment.c net: ipv4: do not handle duplicate fragments as overlapping 2018-12-15 11:50:40 -08:00
ip_gre.c erspan: build the header with the right proto according to erspan_ver 2019-01-16 13:36:43 -08:00
ip_input.c net: Fix usage of pskb_trim_rcsum 2019-01-18 14:05:14 -08:00
ip_options.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
ip_output.c sk_buff: add skb extension infrastructure 2018-12-19 11:21:37 -08:00
ip_sockglue.c ip: on queued skb use skb_header_pointer instead of pskb_may_pull 2019-01-10 09:27:20 -05:00
ip_tunnel_core.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2018-12-24 16:19:56 -08:00
ip_tunnel.c ip: validate header length on virtual device xmit 2019-01-01 12:05:02 -08:00
ip_vti.c ip: validate header length on virtual device xmit 2019-01-01 12:05:02 -08:00
ipcomp.c net-ipv4: remove 2 always zero parameters from ipv4_redirect() 2018-09-26 20:30:55 -07:00
ipconfig.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2018-12-20 11:53:36 -08:00
ipip.c net: Convert protocol error handlers from void to int 2018-11-08 17:13:08 -08:00
ipmr_base.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2018-10-19 11:03:06 -07:00
ipmr.c net: ipv4: ipmr: perform strict checks also for doit handlers 2019-01-19 10:09:58 -08:00
Kconfig net: remove blank lines at end of file 2018-07-24 14:10:43 -07:00
Makefile bpf, sockmap: convert to generic sk_msg interface 2018-10-15 12:23:19 -07:00
metrics.c net: Add extack argument to ip_fib_metrics_init 2018-11-06 15:00:45 -08:00
netfilter.c netfilter: utils: move nf_ip_checksum* from ipv4 to utils 2018-07-16 17:51:48 +02:00
netlink.c ipv4: support sport, dport and ip_proto in RTM_GETROUTE 2018-05-23 15:14:12 -04:00
ping.c ipv4: Allow sending multicast packets on specific i/f using VRF socket 2018-10-02 22:28:17 -07:00
proc.c tcp: implement coalescing on backlog queue 2018-11-30 13:26:54 -08:00
protocol.c fou, fou6: ICMP error handlers for FoU and GUE 2018-11-08 17:13:08 -08:00
raw_diag.c net: ipv6: add second dif to raw socket lookups 2017-08-07 11:39:22 -07:00
raw.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2018-12-20 11:53:36 -08:00
route.c net: ipv4: route: perform strict checks also for doit handlers 2019-01-19 10:09:58 -08:00
syncookies.c tcp: provide earliest departure time in skb->tstamp 2018-09-21 19:37:59 -07:00
sysctl_net_ipv4.c net: provide a sysctl raw_l3mdev_accept for raw socket lookup with VRFs 2018-11-07 16:12:38 -08:00
tcp_bbr.c tcp_bbr: update comments to reflect pacing_margin_percent 2018-11-08 20:46:17 -08:00
tcp_bic.c tcp: consolidate congestion control undo functions 2017-08-06 21:25:10 -07:00
tcp_bpf.c bpf: sk_msg, sock{map|hash} redirect through ULP 2018-12-20 23:47:09 +01:00
tcp_cdg.c tcp: cdg: use tcp high resolution clock cache 2018-10-15 22:56:42 -07:00
tcp_cong.c tcp: Namespace-ify sysctl_tcp_default_congestion_control 2017-11-15 14:09:52 +09:00
tcp_cubic.c tcp: consolidate congestion control undo functions 2017-08-06 21:25:10 -07:00
tcp_dctcp.c tcp: refactor DCTCP ECN ACK handling 2018-10-10 22:26:00 -07:00
tcp_dctcp.h tcp: refactor DCTCP ECN ACK handling 2018-10-10 22:26:00 -07:00
tcp_diag.c net: sock: replace sk_state_load with inet_sk_state_load and remove sk_state_store 2017-12-20 14:00:25 -05:00
tcp_fastopen.c tcp: pause Fast Open globally after third consecutive timeout 2017-12-13 15:51:12 -05:00
tcp_highspeed.c tcp: consolidate congestion control undo functions 2017-08-06 21:25:10 -07:00
tcp_htcp.c
tcp_hybla.c
tcp_illinois.c net/tcp/illinois: replace broken algorithm reference link 2018-02-28 12:03:47 -05:00
tcp_input.c tcp: take care of compressed acks in tcp_add_reno_sack() 2018-11-30 13:26:53 -08:00
tcp_ipv4.c tcp: md5: add tcp_md5_needed jump label 2018-11-30 13:28:03 -08:00
tcp_lp.c
tcp_metrics.c mm: convert totalram_pages and totalhigh_pages variables to atomic 2018-12-28 12:11:47 -08:00
tcp_minisocks.c tcp: move rx_opt & syn_data_acked init to tcp_disconnect() 2019-01-17 22:19:05 -08:00
tcp_nv.c tcp_nv: fix potential integer overflow in tcpnv_acked 2018-01-31 10:26:30 -05:00
tcp_offload.c net: use indirect call wrappers at GRO transport layer 2018-12-15 13:23:02 -08:00
tcp_output.c tcp: less aggressive window probing on local congestion 2019-01-17 15:12:26 -08:00
tcp_rate.c tcp: introduce tcp_skb_timestamp_us() helper 2018-09-21 19:37:59 -07:00
tcp_recovery.c tcp: introduce tcp_skb_timestamp_us() helper 2018-09-21 19:37:59 -07:00
tcp_scalable.c tcp: consolidate congestion control undo functions 2017-08-06 21:25:10 -07:00
tcp_timer.c tcp: retry more conservatively on local congestion 2019-01-17 15:12:26 -08:00
tcp_ulp.c tcp, ulp: remove socket lock assertion on ULP cleanup 2018-10-16 12:38:41 -07:00
tcp_vegas.c tcp: fix under-evaluated ssthresh in TCP Vegas 2017-09-29 06:07:00 +01:00
tcp_vegas.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
tcp_veno.c tcp: consolidate congestion control undo functions 2017-08-06 21:25:10 -07:00
tcp_westwood.c tcp: Revert "tcp: remove CA_ACK_SLOWPATH" 2017-08-30 11:20:08 -07:00
tcp_yeah.c tcp: consolidate congestion control undo functions 2017-08-06 21:25:10 -07:00
tcp.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2019-01-21 14:41:32 -08:00
tunnel4.c net: Convert protocol error handlers from void to int 2018-11-08 17:13:08 -08:00
udp_diag.c net: diag: document swapped src/dst in udp_dump_one. 2018-10-28 19:27:21 -07:00
udp_impl.h udp: add missing rehash callback to udplite 2019-01-17 15:01:08 -08:00
udp_offload.c udp: use indirect call wrappers for GRO socket lookup 2018-12-15 13:23:02 -08:00
udp_tunnel.c net/ipv4/udp_tunnel: prefer SO_BINDTOIFINDEX over SO_BINDTODEVICE 2019-01-17 14:55:52 -08:00
udp.c udp: add missing rehash callback to udplite 2019-01-17 15:01:08 -08:00
udplite.c udp: add missing rehash callback to udplite 2019-01-17 15:01:08 -08:00
xfrm4_input.c xfrm: reset transport header back to network header after all input transforms ahave been applied 2018-09-04 10:26:30 +02:00
xfrm4_mode_beet.c
xfrm4_mode_transport.c xfrm: reset transport header back to network header after all input transforms ahave been applied 2018-09-04 10:26:30 +02:00
xfrm4_mode_tunnel.c xfrm: Verify MAC header exists before overwriting eth_hdr(skb)->h_proto 2018-03-07 10:54:29 +01:00
xfrm4_output.c net: xfrm: use skb_gso_validate_network_len() to check gso sizes 2018-03-04 17:49:17 -05:00
xfrm4_policy.c net: Drop pernet_operations::async 2018-03-27 13:18:09 -04:00
xfrm4_protocol.c net: Convert protocol error handlers from void to int 2018-11-08 17:13:08 -08:00
xfrm4_state.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
xfrm4_tunnel.c