linux/net/ipv4
Sabrina Dubroca d52e5a7e7c ipv4: lock mtu in fnhe when received PMTU < net.ipv4.route.min_pmtu
Prior to the rework of PMTU information storage in commit
2c8cec5c10 ("ipv4: Cache learned PMTU information in inetpeer."),
when a PMTU event advertising a PMTU smaller than
net.ipv4.route.min_pmtu was received, we would disable setting the DF
flag on packets by locking the MTU metric, and set the PMTU to
net.ipv4.route.min_pmtu.

Since then, we don't disable DF, and set PMTU to
net.ipv4.route.min_pmtu, so the intermediate router that has this link
with a small MTU will have to drop the packets.

This patch reestablishes pre-2.6.39 behavior by splitting
rtable->rt_pmtu into a bitfield with rt_mtu_locked and rt_pmtu.
rt_mtu_locked indicates that we shouldn't set the DF bit on that path,
and is checked in ip_dont_fragment().

One possible workaround is to set net.ipv4.route.min_pmtu to a value low
enough to accommodate the lowest MTU encountered.

Fixes: 2c8cec5c10 ("ipv4: Cache learned PMTU information in inetpeer.")
Signed-off-by: Sabrina Dubroca <sd@queasysnail.net>
Reviewed-by: Stefano Brivio <sbrivio@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-03-14 13:37:36 -04:00
..
netfilter net: rename skb_gso_validate_mtu -> skb_gso_validate_network_len 2018-03-04 17:49:17 -05:00
af_inet.c vfs: do bulk POLL* -> EPOLL* replacement 2018-02-11 14:34:03 -08:00
ah4.c net: use -ENOSPC for transient busy indication 2017-11-03 22:11:17 +08:00
arp.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2018-01-17 00:10:42 -05:00
cipso_ipv4.c tcp/dccp: fix ireq->opt races 2017-10-21 01:33:19 +01:00
datagram.c
devinet.c ipv4: Get the address of interface correctly. 2018-01-29 14:32:31 -05:00
esp4_offload.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2018-01-23 13:51:56 -05:00
esp4.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2018-01-17 00:10:42 -05:00
fib_frontend.c ip_rt_ioctl(): take copyin to caller 2018-01-24 19:13:45 -05:00
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 net: fib_rules: Implement notification logic in core 2017-08-03 15:35:59 -07:00
fib_semantics.c fib_semantics: Don't match route with mismatching tclassid 2018-02-16 15:19:54 -05:00
fib_trie.c net: delete /proc THIS_MODULE references 2018-01-16 15:01:33 -05:00
fou.c gue: fix remcsum when GRO on and CHECKSUM_PARTIAL boundary is outer UDP 2017-08-01 16:09:14 -07:00
gre_demux.c
gre_offload.c gso: fix payload length when gso_size is zero 2017-10-08 10:12:15 -07:00
icmp.c ipv4: icmp: use BUG_ON instead of if condition followed by BUG 2017-10-24 18:44:42 +09:00
igmp.c net: igmp: add a missing rcu locking section 2018-02-01 14:58:04 -05:00
inet_connection_sock.c Revert "defer call to mem_cgroup_sk_alloc()" 2018-02-02 19:49:31 -05:00
inet_diag.c sock_diag: request _diag module only when the family or proto has been registered 2018-03-12 11:03:42 -04:00
inet_fragment.c net: Fix hlist corruptions in inet_evict_bucket() 2018-03-07 13:29:28 -05:00
inet_hashtables.c inet: Avoid unitialized variable warning in inet_unhash() 2018-02-01 09:48:42 -05:00
inet_timewait_sock.c net: Convert atomic_t net::count to refcount_t 2018-01-15 14:23:42 -05:00
inetpeer.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2017-10-05 18:19:22 -07:00
ip_forward.c net: rename skb_gso_validate_mtu -> skb_gso_validate_network_len 2018-03-04 17:49:17 -05:00
ip_fragment.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2017-11-04 09:26:51 +09:00
ip_gre.c ip_gre: fix IFLA_MTU ignored on NEWLINK 2018-02-27 14:36:27 -05:00
ip_input.c IPv4: early demux can return an error code 2017-10-01 03:55:47 +01:00
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 net: rename skb_gso_validate_mtu -> skb_gso_validate_network_len 2018-03-04 17:49:17 -05:00
ip_sockglue.c net: Only honor ifindex in IP_PKTINFO if non-0 2018-03-06 16:36:44 -05:00
ip_tunnel_core.c net: store port/representator id in metadata_dst 2017-06-25 11:42:01 -04:00
ip_tunnel.c ip_tunnel: Do not use mark in skb by default 2018-02-26 15:22:59 -05:00
ip_vti.c net: don't call update_pmtu unconditionally 2018-01-25 16:27:34 -05:00
ipcomp.c
ipconfig.c ipconfig: use dev_set_mtu() 2018-01-24 19:13:45 -05:00
ipip.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2017-10-30 21:09:24 +09:00
ipmr.c ipmr: Fix ptrdiff_t print formatting 2018-01-30 09:20:25 -05:00
Kconfig ip: update policy routing config help 2017-10-12 22:57:11 -07:00
Makefile net: tcp: Remove TCP probe module 2018-01-02 14:27:29 -05:00
netfilter.c netfilter: remove struct nf_afinfo and its helper functions 2018-01-08 18:11:02 +01:00
ping.c net: convert sock.sk_refcnt from atomic_t to refcount_t 2017-07-01 07:39:08 -07:00
proc.c net: delete /proc THIS_MODULE references 2018-01-16 15:01:33 -05:00
protocol.c net: Add sysctl to toggle early demux for tcp and udp 2017-03-24 13:17:07 -07:00
raw_diag.c net: ipv6: add second dif to raw socket lookups 2017-08-07 11:39:22 -07:00
raw.c Currently, hardened usercopy performs dynamic bounds checking on slab 2018-02-03 16:25:42 -08:00
route.c ipv4: lock mtu in fnhe when received PMTU < net.ipv4.route.min_pmtu 2018-03-14 13:37:36 -04:00
syncookies.c tcp: Namespace-ify sysctl_tcp_workaround_signed_windows 2017-10-28 19:24:38 +09:00
sysctl_net_ipv4.c tcp: Namespace-ify sysctl_tcp_default_congestion_control 2017-11-15 14:09:52 +09:00
tcp_bbr.c tcp_bbr: fix pacing_gain to always be unity when using lt_bw 2018-02-01 09:43:38 -05:00
tcp_bic.c tcp: consolidate congestion control undo functions 2017-08-06 21:25:10 -07:00
tcp_cdg.c tcp: cdg: make struct tcp_cdg static 2017-10-16 21:24:25 +01:00
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_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: fix cwnd undo in Reno and HTCP congestion controls 2017-08-06 21:25:10 -07:00
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: purge write queue upon RST 2018-02-28 11:41:33 -05:00
tcp_ipv4.c tcp: tracepoint: only call trace_tcp_send_reset with full socket 2018-02-07 22:00:42 -05:00
tcp_lp.c tcp: switch TCP TS option (RFC 7323) to 1ms clock 2017-05-17 16:06:01 -04:00
tcp_metrics.c net: Convert atomic_t net::count to refcount_t 2018-01-15 14:23:42 -05:00
tcp_minisocks.c tcp/dccp: avoid one atomic operation for timewait hashdance 2017-12-13 14:33:10 -05:00
tcp_nv.c tcp_nv: fix potential integer overflow in tcpnv_acked 2018-01-31 10:26:30 -05:00
tcp_offload.c gso: validate gso_type in GSO handlers 2018-01-22 16:01:30 -05:00
tcp_output.c tcp_bbr: better deal with suboptimal GSO 2018-02-22 14:15:23 -05:00
tcp_rate.c tcp: invalidate rate samples during SACK reneging 2017-12-08 10:07:02 -05:00
tcp_recovery.c tcp: evaluate packet losses upon RTT change 2017-12-08 14:14:11 -05:00
tcp_scalable.c tcp: consolidate congestion control undo functions 2017-08-06 21:25:10 -07:00
tcp_timer.c tcp: purge write queue upon aborting the connection 2018-03-07 15:01:03 -05:00
tcp_ulp.c net: add a UID to use for ULP socket assignment 2018-02-06 11:39:31 +01:00
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 tcp: purge write queue upon aborting the connection 2018-03-07 15:01:03 -05:00
tunnel4.c
udp_diag.c net: ipv6: add second dif to udp socket lookups 2017-08-07 11:39:22 -07:00
udp_impl.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
udp_offload.c gso: validate gso_type in GSO handlers 2018-01-22 16:01:30 -05:00
udp_tunnel.c net: add infrastructure to un-offload UDP tunnel port 2017-07-24 13:52:59 -07:00
udp.c udplite: fix partial checksum initialization 2018-02-16 15:57:42 -05:00
udplite.c net: delete /proc THIS_MODULE references 2018-01-16 15:01:33 -05:00
xfrm4_input.c xfrm: Reinject transport-mode packets through tasklet 2017-12-19 08:23:21 +01:00
xfrm4_mode_beet.c networking: make skb_pull & friends return void pointers 2017-06-16 11:48:39 -04:00
xfrm4_mode_transport.c xfrm: Add encapsulation header offsets while SKB is not encrypted 2017-04-14 10:07:39 +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 ipv4: lock mtu in fnhe when received PMTU < net.ipv4.route.min_pmtu 2018-03-14 13:37:36 -04:00
xfrm4_protocol.c
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