linux/include/net
Eric Dumazet 5f3e2bf008 tcp: add tcp_min_snd_mss sysctl
Some TCP peers announce a very small MSS option in their SYN and/or
SYN/ACK messages.

This forces the stack to send packets with a very high network/cpu
overhead.

Linux has enforced a minimal value of 48. Since this value includes
the size of TCP options, and that the options can consume up to 40
bytes, this means that each segment can include only 8 bytes of payload.

In some cases, it can be useful to increase the minimal value
to a saner value.

We still let the default to 48 (TCP_MIN_SND_MSS), for compatibility
reasons.

Note that TCP_MAXSEG socket option enforces a minimal value
of (TCP_MIN_MSS). David Miller increased this minimal value
in commit c39508d6f1 ("tcp: Make TCP_MAXSEG minimum more correct.")
from 64 to 88.

We might in the future merge TCP_MIN_SND_MSS and TCP_MIN_MSS.

CVE-2019-11479 -- tcp mss hardcoded to 48

Signed-off-by: Eric Dumazet <edumazet@google.com>
Suggested-by: Jonathan Looney <jtl@netflix.com>
Acked-by: Neal Cardwell <ncardwell@google.com>
Cc: Yuchung Cheng <ycheng@google.com>
Cc: Tyler Hicks <tyhicks@canonical.com>
Cc: Bruce Curtis <brucec@netflix.com>
Cc: Jonathan Lemon <jonathan.lemon@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-06-15 18:47:31 -07:00
..
9p treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 188 2019-05-30 11:29:21 -07:00
bluetooth Bluetooth: Ignore CC events not matching the last HCI command 2019-05-05 19:29:04 +02:00
caif treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 194 2019-05-30 11:29:22 -07:00
iucv net/af_iucv: locate IUCV header via skb_network_header() 2018-09-26 09:56:07 -07:00
netfilter netfilter: nft_fib: Fix existence check support 2019-05-21 16:10:38 +02:00
netns tcp: add tcp_min_snd_mss sysctl 2019-06-15 18:47:31 -07:00
nfc treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 13 2019-05-21 11:28:45 +02:00
phonet phonet: fix building with clang 2019-02-21 16:23:56 -08:00
sctp treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 104 2019-05-24 17:39:00 +02:00
tc_act treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 201 2019-05-30 11:29:52 -07:00
6lowpan.h
act_api.h net/sched: let actions use RCU to access 'goto_chain' 2019-03-21 13:26:42 -07:00
addrconf.h vrf: Increment Icmp6InMsgs on the original netdev 2019-06-12 11:00:11 -07:00
af_ieee802154.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 174 2019-05-30 11:26:41 -07:00
af_rxrpc.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
af_unix.h net: split out functions related to registering inflight socket files 2019-02-28 08:24:23 -07:00
af_vsock.h vsock: split dwork to avoid reinitializations 2018-08-07 12:39:13 -07:00
ah.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
arp.h ipv4: Define __ipv4_neigh_lookup_noref when CONFIG_INET is disabled 2019-05-05 11:25:49 -07:00
atmclip.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
ax25.h ax25: fix possible use-after-free 2019-01-23 11:18:00 -08:00
ax88796.h net-next: ax88796: add interrupt status callback to platform data 2018-04-19 16:11:11 -04:00
bond_3ad.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 90 2019-05-24 17:37:53 +02:00
bond_alb.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 5 2019-05-21 11:28:40 +02:00
bond_options.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
bonding.h bonding: avoid possible dead-lock 2018-09-26 20:22:19 -07:00
bpf_sk_storage.h bpf: Introduce bpf sk local storage 2019-04-27 09:07:04 -07:00
busy_poll.h net: remove sock_poll_busy_flag 2018-07-30 09:10:25 -07:00
calipso.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 13 2019-05-21 11:28:45 +02:00
cfg80211-wext.h
cfg80211.h {nl,mac}80211: allow 4addr AP operation on crypto controlled devices 2019-05-24 11:26:54 +02:00
cfg802154.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 174 2019-05-30 11:26:41 -07:00
checksum.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
cipso_ipv4.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 13 2019-05-21 11:28:45 +02:00
cls_cgroup.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
codel_impl.h
codel_qdisc.h
codel.h
compat.h net: rework SIOCGSTAMP ioctl handling 2019-04-19 14:07:40 -07:00
datalink.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
dcbevent.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 201 2019-05-30 11:29:52 -07:00
dcbnl.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 201 2019-05-30 11:29:52 -07:00
devlink.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
dn_dev.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
dn_fib.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
dn_neigh.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
dn_nsp.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 24 2019-05-21 11:52:39 +02:00
dn_route.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 24 2019-05-21 11:52:39 +02:00
dn.h Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2017-11-04 09:26:51 +09:00
dsa.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
dsfield.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
dst_cache.h net: core: dst_cache_set_ip6: Rename 'addr' parameter to 'saddr' for consistency 2018-03-05 12:52:45 -05:00
dst_metadata.h Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2017-11-04 09:26:51 +09:00
dst_ops.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
dst.h net: dst: remove gc leftovers 2019-03-21 13:39:25 -07:00
erspan.h erspan: set bso bit based on mirrored packet's len 2018-05-20 18:31:42 -04:00
esp.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
ethoc.h inet: whitespace cleanup 2018-02-28 11:43:28 -05:00
failover.h net: Introduce generic failover module 2018-05-28 22:59:54 -04:00
fib_notifier.h net: fib: drop include of module.h from fib_notifier.h 2019-04-22 21:50:53 -07:00
fib_rules.h net: fib_rules: add extack support 2018-04-23 10:21:24 -04:00
firewire.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
flow_dissector.h net: ethtool: Allow matching on vlan DEI bit 2019-06-12 10:09:56 -07:00
flow_offload.h flow_offload: support CVLAN match 2019-05-16 12:02:42 -07:00
flow.h route: Add multipath_hash in flowi_common to make user-define hash 2019-02-27 12:50:17 -08:00
fou.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
fq_impl.h mac80211: calculate hash for fq without holding fq->lock in itxq enqueue 2019-04-26 13:02:11 +02:00
fq.h fq: support filtering a given tin 2017-10-11 09:49:34 +02:00
garp.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
gen_stats.h net: align gnet_stats_basic_cpu struct 2018-11-17 21:37:29 -08:00
genetlink.h genetlink: optionally validate strictly/dumps 2019-04-27 17:07:22 -04:00
geneve.h net: Move the definition of the default Geneve udp port to public header file 2019-03-22 12:09:31 -07:00
gre.h net: Add netif_is_gretap()/netif_is_ip6gretap() 2018-12-10 15:53:04 -08:00
gro_cells.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
gtp.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
gue.h fou: fix some member types in guehdr 2017-12-11 14:10:06 -05:00
hwbm.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
icmp.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
ieee80211_radiotap.h wireless-drivers-next patches for 5.1 2019-02-22 12:56:24 -08:00
ieee802154_netdev.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 174 2019-05-30 11:26:41 -07:00
if_inet6.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
ife.h net: ife: drop include of module.h from net/ife.h 2019-04-22 21:50:53 -07:00
ila.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
inet6_connection_sock.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
inet6_hashtables.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
inet_common.h net: use indirect call wrappers at GRO transport layer 2018-12-15 13:23:02 -08:00
inet_connection_sock.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
inet_ecn.h inet: Refactor INET_ECN_decapsulate() 2018-10-17 17:45:07 -07:00
inet_frag.h net: remove unused struct inet_frag_queue.fragments field 2019-02-26 08:27:05 -08:00
inet_hashtables.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
inet_sock.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
inet_timewait_sock.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
inetpeer.h net: ipv4: use a dedicated counter for icmp_v4 redirect packets 2019-02-08 21:50:15 -08:00
ip6_checksum.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
ip6_fib.h Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2019-06-07 09:29:14 -07:00
ip6_route.h net: Change nhc_flags to unsigned char 2019-04-23 19:44:18 -07:00
ip6_tunnel.h udp: Support for error handlers of tunnels with arbitrary destination port 2018-11-08 17:13:08 -08:00
ip_fib.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
ip_tunnels.h route: Add multipath_hash in flowi_common to make user-define hash 2019-02-27 12:50:17 -08:00
ip_vs.h ipvs: allow tunneling with gue encapsulation 2019-04-08 22:57:59 +02:00
ip.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
ipcomp.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
ipconfig.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
ipv6_frag.h ip6: fix skb leak in ip6frag_expire_frag_queue() 2019-05-05 10:40:24 -07:00
ipv6_stubs.h ipv6: Pass fib6_result to fib lookups 2019-04-17 23:10:47 -07:00
ipv6.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
ipx.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
iw_handler.h net: Spelling s/stucture/structure/ 2018-03-27 09:51:23 +02:00
kcm.h
l3mdev.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
lag.h net: Add lag.h, net_lag_port_dev_txable() 2018-07-11 23:10:19 -07:00
lapb.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
lib80211.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
llc_c_ac.h net: LLC: Convert timers to use timer_setup() 2017-10-25 12:06:25 +09:00
llc_c_ev.h
llc_c_st.h
llc_conn.h llc: delete timers synchronously in llc_sk_free() 2018-04-22 14:55:03 -04:00
llc_if.h
llc_pdu.h
llc_s_ac.h
llc_s_ev.h
llc_s_st.h
llc_sap.h
llc.h llc: avoid blocking in llc_sap_close() 2018-09-13 09:04:58 -07:00
lwtunnel.h lwtunnel: Pass encap and encap type attributes to lwtunnel_fill_encap 2019-04-23 19:42:29 -07:00
mac80211.h Various updates, notably: 2019-04-26 16:05:52 -04:00
mac802154.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 174 2019-05-30 11:26:41 -07:00
mip6.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 13 2019-05-21 11:28:45 +02:00
mld.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
mpls_iptunnel.h
mpls.h
mrp.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
ncsi.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
ndisc.h ipv6: Add neighbor helpers that use the ipv6 stub 2019-04-08 15:22:40 -07:00
neighbour.h net ipv6: Prevent neighbor add if protocol is disabled on device 2019-04-17 23:19:07 -07:00
net_failover.h net: Introduce net_failover driver 2018-05-28 22:59:54 -04:00
net_namespace.h netns: provide pure entropy for net_hash_mix() 2019-03-28 17:00:45 -07:00
net_ratelimit.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
netevent.h net: ipv4: Notify about changes to ip_forward_update_priority 2018-08-01 09:52:30 -07:00
netlabel.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 13 2019-05-21 11:28:45 +02:00
netlink.h netlink: add validation of NLA_F_NESTED flag 2019-05-04 01:27:11 -04:00
netprio_cgroup.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
netrom.h net: netrom: Fix error cleanup path of nr_proto_init 2019-04-11 13:59:49 -07:00
nl802154.h
nsh.h openvswitch: enable NSH support 2017-11-08 16:12:33 +09:00
p8022.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
page_pool.h xdp: introduce xdp_return_frame_rx_napi 2018-05-24 18:36:15 -07:00
ping.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
pkt_cls.h net/sched: remove block pointer from common offload structure 2019-05-07 12:23:40 -07:00
pkt_sched.h net: sched: extend Qdisc with rcu 2018-09-25 20:17:35 -07:00
pptp.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
protocol.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
psample.h net: psample: drop include of module.h from psample.h 2019-04-22 21:50:53 -07:00
psnap.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
raw.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
rawv6.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
red.h net_sched: red: Avoid illegal values 2017-12-05 14:37:13 -05:00
regulatory.h cfg80211: make wmm_rule part of the reg_rule structure 2018-08-28 11:11:47 +02:00
request_sock.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
rose.h proc: introduce proc_create_seq{,_data} 2018-05-16 07:23:35 +02:00
route.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
rsi_91x.h Bluetooth: btrsi: add new rsi bluetooth driver 2018-03-13 18:37:02 +02:00
rtnetlink.h net: Add extack argument to rtnl_create_link 2018-11-06 15:00:45 -08:00
rtnh.h net: Rename net/nexthop.h net/rtnh.h 2019-04-22 21:47:25 -07:00
sch_generic.h flow_dissector: switch kernel context to struct bpf_flow_dissector 2019-04-23 18:36:33 +02:00
scm.h pids: Compute task_tgid using signal->leader_pid 2018-07-21 10:43:12 -05:00
secure_seq.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
seg6_hmac.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
seg6_local.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
seg6.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
slhc_vj.h slip: Check if rstate is initialized before uncompressing 2018-04-11 10:33:46 -04:00
smc.h net/smc: add smcd support to the pnet table 2019-02-21 10:34:37 -08:00
snmp.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
sock_reuseport.h bpf: Enable BPF_PROG_TYPE_SK_REUSEPORT bpf prog in reuseport selection 2018-08-11 01:58:46 +02:00
sock.h net: add high_order_alloc_disable sysctl/static key 2019-06-14 20:18:28 -07:00
Space.h net/mac89x0: Convert to platform_driver 2018-03-01 21:21:36 -05:00
stp.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
strparser.h strparser: Add __strp_unpause and use it in ktls. 2018-06-06 14:07:53 -04:00
switchdev.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
tcp_states.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
tcp.h tcp: limit payload size of sacked skbs 2019-06-15 18:47:31 -07:00
timewait_sock.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
tipc.h flow_dissector: do not rely on implicit casts 2018-05-08 00:02:41 -04:00
tls.h net/tls: replace the sleeping lock around RX resync with a bit lock 2019-06-04 13:34:37 -07:00
transp_v6.h ipv6: fold sockcm_cookie into ipcm6_cookie 2018-07-07 10:58:49 +09:00
tso.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
tun_proto.h vxlan: factor out VXLAN-GPE next protocol 2017-08-29 15:16:52 -07:00
udp_tunnel.h ipv6: Move ipv6 stubs to a separate header file 2019-03-29 10:53:45 -07:00
udp.h SPDX update for 5.2-rc3, round 1 2019-05-31 08:34:32 -07:00
udplite.h udplite: fix partial checksum initialization 2018-02-16 15:57:42 -05:00
vsock_addr.h
vxlan.h net: Add IANA_VXLAN_UDP_PORT definition to vxlan header file 2019-03-22 12:09:31 -07:00
wext.h lift handling of SIOCIW... out of dev_ioctl() 2018-01-24 19:13:45 -05:00
wimax.h
x25.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
x25device.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
xdp_sock.h xsk: fix umem memory leak on cleanup 2019-03-16 01:27:51 +01:00
xdp.h xdp: export xdp_rxq_info_unreg_mem_model 2018-08-29 12:25:53 -07:00
xfrm.h Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2019-05-07 22:03:58 -07:00