Fernando Fernandez Mancera 7da62262ec inet: add ip_local_port_step_width sysctl to improve port usage distribution ... With the current port selection algorithm, ports after a reserved port range or long time used port are used more often than others [1]. This causes an uneven port usage distribution. This combines with cloud environments blocking connections between the application server and the database server if there was a previous connection with the same source port, leading to connectivity problems between applications on cloud environments. The real issue here is that these firewalls cannot cope with standards-compliant port reuse. This is a workaround for such situations and an improvement on the distribution of ports selected. The proposed solution is to implement a variant of RFC 6056 Algorithm 5. The step size is selected randomly on every connect() call ensuring it is a coprime with respect to the size of the range of ports we want to scan. This way, we can ensure that all ports within the range are scanned before returning an error. To enable this algorithm, the user must configure the new sysctl option "net.ipv4.ip_local_port_step_width". In addition, on graphs generated we can observe that the distribution of source ports is more even with the proposed approach. [2] [1] https://0xffsoftware.com/port_graph_current_alg.html [2] https://0xffsoftware.com/port_graph_random_step_alg.html Reviewed-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Fernando Fernandez Mancera <fmancera@suse.de> Link: https://patch.msgid.link/20260309023946.5473-2-fmancera@suse.de Signed-off-by: Jakub Kicinski <kuba@kernel.org>		2026-03-10 18:59:39 -07:00
..
9p	9p: convert to the new mount API	2025-11-03 16:49:53 +09:00
bluetooth	Bluetooth: L2CAP: Fix result of L2CAP_ECRED_CONN_RSP when MTU is too short	2026-02-23 15:28:56 -05:00
caif	caif: Remove unused cfsrvl_getphyid	2024-10-08 15:33:49 -07:00
iucv	treewide: Replace kmalloc with kmalloc_obj for non-scalar types	2026-02-21 01:02:28 -08:00
libeth	libeth, idpf: use truesize as XDP RxQ info frag_size	2026-03-05 08:02:05 -08:00
mana	net: mana: hardening: Validate doorbell ID from GDMA_REGISTER_DEVICE response	2026-03-10 13:39:51 +01:00
netfilter	Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net	2026-03-05 12:11:05 -08:00
netns	inet: add ip_local_port_step_width sysctl to improve port usage distribution	2026-03-10 18:59:39 -07:00
nfc	nfc: nci: Fix race between rfkill and nci_unregister_device().	2026-01-28 19:32:26 -08:00
page_pool	Revert "Merge branch 'netkit-support-for-io_uring-zero-copy-and-af_xdp'"	2026-01-20 18:06:01 -08:00
phonet	phonet: Convert phonet_routes.lock to spinlock_t.	2024-10-24 16:03:40 +02:00
phy	net: phy: realtek: add dummy PHY driver for RTL8127ATF	2026-01-12 19:29:11 -08:00
psp	psp: add stats from psp spec to driver facing api	2025-11-07 18:53:57 -08:00
sctp	sctp: Remove unused declaration sctp_auth_init_hmacs()	2025-11-14 18:00:34 -08:00
tc_act	net/sched: act_ife: Fix metalist update behavior	2026-03-05 07:54:08 -08:00
6lowpan.h	…
Space.h	net: appletalk: remove cops support	2023-10-04 11:49:20 -07:00
act_api.h	net/sched: Only allow act_ct to bind to clsact/ingress qdiscs and shared blocks	2026-02-27 19:06:21 -08:00
addrconf.h	ipv6: addrconf: reduce default temp_valid_lft to 2 days	2026-02-17 17:12:06 -08:00
af_ieee802154.h	…
af_rxrpc.h	rxrpc: Remove deadcode	2025-04-24 17:03:45 -07:00
af_unix.h	af_unix: Introduce SO_INQ.	2025-07-08 18:05:25 -07:00
af_vsock.h	vsock: lock down child_ns_mode as write-once	2026-02-26 11:10:03 +01:00
ah.h	…
aligned_data.h	udp: move udp_memory_allocated into net_aligned_data	2025-07-02 14:22:02 -07:00
amt.h	…
arp.h	…
atmclip.h	…
ax25.h	Summary	2026-02-18 10:45:36 -08:00
ax88796.h	…
bareudp.h	…
bond_3ad.h	bonding: support aggregator selection based on port priority	2025-09-09 10:56:02 +02:00
bond_alb.h	bonding: Correct spelling in headers	2024-08-26 09:37:22 -07:00
bond_options.h	bonding: add support for per-port LACP actor priority	2025-09-09 10:56:02 +02:00
bonding.h	Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net	2026-03-05 12:11:05 -08:00
bpf_sk_storage.h	…
busy_poll.h	net: gro: decouple GRO from the NAPI layer	2025-02-27 14:03:14 +01:00
calipso.h	move asm/unaligned.h to linux/unaligned.h	2024-10-02 17:23:23 -04:00
can.h	can: add CAN skb extension infrastructure	2026-02-05 11:58:39 +01:00
cfg80211-wext.h	…
cfg80211.h	wifi: cfg80211: support key installation on non-netdev wdevs	2026-03-02 11:28:33 +01:00
cfg802154.h	mac802154: fix llsec key resources release in mac802154_llsec_key_del	2024-03-06 21:01:26 +01:00
checksum.h	net: Fix checksum update for ILA adj-transport	2025-05-30 19:53:51 -07:00
cipso_ipv4.h	move asm/unaligned.h to linux/unaligned.h	2024-10-02 17:23:23 -04:00
cls_cgroup.h	net/cls_cgroup: Fix task_get_classid() during qdisc run	2025-09-14 11:55:04 -07:00
codel.h	…
codel_impl.h	…
codel_qdisc.h	…
compat.h	…
datalink.h	…
dcbevent.h	…
dcbnl.h	…
devlink.h	devlink: support default values for param-get and param-set	2025-11-20 19:01:22 -08:00
dropreason-core.h	net: sched: sch_dualpi2: use qdisc_dequeue_drop() for dequeue drops	2026-02-28 15:31:35 -08:00
dropreason-qdisc.h	net: sched: sch_dualpi2: use qdisc_dequeue_drop() for dequeue drops	2026-02-28 15:31:35 -08:00
dropreason.h	net: sched: introduce qdisc-specific drop reason tracing	2026-02-28 15:31:34 -08:00
dsa.h	net: dsa: add tag format for MxL862xx switches	2026-02-11 11:27:57 +01:00
dsa_stubs.h	net: dsa: Use conduit and user terms	2023-10-24 13:08:14 -07:00
dscp.h	net: add IEEE 802.1q specific helpers	2024-05-08 10:35:09 +01:00
dsfield.h	…
dst.h	inet: add dst4_mtu() and dst6_mtu() helpers	2026-02-02 17:49:29 -08:00
dst_cache.h	net: Correct spelling in headers	2024-08-26 09:37:23 -07:00
dst_metadata.h	net: dst_metadata: fix IP_DF bit not extracted from tunnel headers	2025-09-14 14:28:12 -07:00
dst_ops.h	net: fix __dst_negative_advice() race	2024-05-29 17:34:49 -07:00
eee.h	net: simplify eeecfg_mac_can_tx_lpi	2024-11-13 18:49:50 -08:00
erspan.h	net: Correct spelling in headers	2024-08-26 09:37:23 -07:00
esp.h	…
espintcp.h	inet: preserve const qualifier in inet_csk()	2024-04-01 21:27:08 -07:00
ethoc.h	…
failover.h	…
fib_notifier.h	net: do not acquire rtnl in fib_seq_sum()	2024-10-11 15:35:05 -07:00
fib_rules.h	net: fib_rules: Fix iif / oif matching on L3 master device	2025-04-15 17:54:56 -07:00
firewire.h	…
flow.h	ipv4: Convert ->flowi4_tos to dscp_t.	2025-08-26 17:34:31 -07:00
flow_dissector.h	flow_dissector: cleanup FLOW_DISSECTOR_KEY_ENC_FLAGS	2024-07-15 09:14:39 -07:00
flow_offload.h	net: dsa: eliminate local type for tc policers	2026-02-10 15:30:11 +01:00
fou.h	…
fq.h	…
fq_impl.h	Convert 'alloc_obj' family to use the new default GFP_KERNEL argument	2026-02-21 17:09:51 -08:00
garp.h	…
gen_stats.h	…
genetlink.h	genetlink: fix typo in comment	2025-09-03 15:16:49 -07:00
geneve.h	…
gre.h	ip_tunnel: convert __be16 tunnel flags to bitmaps	2024-04-01 10:49:28 +01:00
gro.h	gro: inline tcp6_gro_complete()	2026-01-21 19:28:32 -08:00
gro_cells.h	…
gso.h	…
gtp.h	gtp: properly parse extension headers	2024-05-07 01:35:55 +02:00
gue.h	…
handshake.h	…
hotdata.h	net-sysfs: use rps_tag_ptr and remove metadata from rps_sock_flow_table	2026-03-04 16:54:09 -08:00
hwbm.h	net: Correct spelling in headers	2024-08-26 09:37:23 -07:00
icmp.h	ipv4: icmp: Pass IPv4 control block structure as an argument to __icmp_send()	2025-09-11 12:22:38 +02:00
ieee8021q.h	net: add IEEE 802.1q specific helpers	2024-05-08 10:35:09 +01:00
ieee80211_radiotap.h	wifi: mac80211: add RX flag to report radiotap VHT information	2025-10-30 08:38:51 +01:00
ieee802154_netdev.h	mac802154: Handle association requests from peers	2023-11-20 11:43:03 +01:00
if_inet6.h	ipv6: anycast: complete RCU handling of struct ifacaddr6	2024-02-26 18:40:34 -08:00
ife.h	…
inet6_connection_sock.h	tcp: move inet6_csk_update_pmtu() to tcp_ipv6.c	2026-02-24 17:47:27 -08:00
inet6_hashtables.h	tcp: Initialise ehash secrets during connect() and listen().	2026-03-05 18:50:05 -08:00
inet_common.h	net: remove addr_len argument of recvmsg() handlers	2026-03-02 18:17:17 -08:00
inet_connection_sock.h	Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net	2026-02-26 10:23:00 -08:00
inet_dscp.h	ipv4: Convert ->flowi4_tos to dscp_t.	2025-08-26 17:34:31 -07:00
inet_ecn.h	tcp: ECT_1_NEGOTIATION and NEEDS_ACCECN identifiers	2026-02-03 15:13:24 +01:00
inet_frag.h	inet: frags: flush pending skbs in fqdir_pre_exit()	2025-12-10 01:15:27 -08:00
inet_hashtables.h	Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net	2026-03-05 12:11:05 -08:00
inet_sock.h	ipv6: colocate inet6_cork in inet_cork_full	2026-02-02 17:49:30 -08:00
inet_timewait_sock.h	tcp: Update bind bucket state on port release	2025-09-23 10:12:15 +02:00
inetpeer.h	inetpeer: remove create argument of inet_getpeer()	2024-12-17 19:37:00 -08:00
ioam6.h	ipv6: ioam: fix heap buffer overflow in __ioam6_fill_trace_data()	2026-02-13 12:24:05 -08:00
ip.h	Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net	2026-03-05 12:11:05 -08:00
ip6_checksum.h	udp: move udp6_csum_init() back to net/ipv6/udp.c	2026-02-24 16:30:40 -08:00
ip6_fib.h	ipv6: Defer fib6_purge_rt() in fib6_add_rt2node() to fib6_add().	2025-04-24 09:29:56 +02:00
ip6_route.h	ipv6: make ipv6_anycast_destination logic usable without dst_entry	2026-03-04 11:45:44 +01:00
ip6_tunnel.h	ipv6: adopt skb_dst_dev() and skb_dst_dev_net[_rcu]() helpers	2025-07-02 14:32:30 -07:00
ip_fib.h	net: ipv4: fix ARM64 alignment fault in multipath hash seed	2026-03-03 17:20:37 -08:00
ip_tunnels.h	ipv4: ip_tunnel: spread netdev_lockdep_set_classes()	2026-01-08 18:02:35 -08:00
ip_vs.h	ipvs: use more keys for connection hashing	2026-03-04 11:45:45 +01:00
ipcomp.h	xfrm: ipcomp: Use crypto_acomp interface	2025-03-21 17:36:49 +08:00
ipconfig.h	…
ipv6.h	net: remove addr_len argument of recvmsg() handlers	2026-03-02 18:17:17 -08:00
ipv6_frag.h	inet: frags: flush pending skbs in fqdir_pre_exit()	2025-12-10 01:15:27 -08:00
ipv6_stubs.h	net: Convert proto callbacks from sockaddr to sockaddr_unsized	2025-11-04 19:10:33 -08:00
iw_handler.h	Revert "wifi: cfg80211: unexport wireless_nlevent_flush()"	2024-10-09 08:53:01 +02:00
kcm.h	net: kcm: Fix race condition in kcm_unattach()	2025-08-13 18:18:33 -07:00
l3mdev.h	net: l3mdev: use skb_dst_dev_rcu() in l3mdev_l3_out()	2026-02-02 17:09:11 -08:00
lag.h	…
lapb.h	net: lapb: increase LAPB_HEADER_LEN	2024-12-06 17:43:08 -08:00
llc.h	…
llc_c_ac.h	…
llc_c_ev.h	…
llc_c_st.h	llc: Constify struct llc_conn_state_trans	2024-07-15 08:51:01 -07:00
llc_conn.h	…
llc_if.h	…
llc_pdu.h	net: Correct spelling in headers	2024-08-26 09:37:23 -07:00
llc_s_ac.h	…
llc_s_ev.h	…
llc_s_st.h	llc: Constify struct llc_sap_state_trans	2024-07-15 08:51:19 -07:00
llc_sap.h	…
lwtunnel.h	net: dst: annotate data-races around dst->output	2025-07-02 14:32:30 -07:00
mac80211.h	wifi: mac80211: Fix AAD/Nonce computation for management frames with MLO	2026-03-02 09:53:19 +01:00
mac802154.h	move asm/unaligned.h to linux/unaligned.h	2024-10-02 17:23:23 -04:00
macsec.h	net: macsec: Add endianness annotations in salt struct	2025-01-20 12:20:42 +00:00
mctp.h	net: mctp: Allow limiting binds to a peer address	2025-07-15 12:08:39 +02:00
mctpdevice.h	net: mctp: Expose transport binding identifier via IFLA attribute	2024-11-09 09:04:54 -08:00
mip6.h	…
mld.h	…
mpls.h	…
mpls_iptunnel.h	…
mptcp.h	mptcp: sched: remove mptcp_sched_data	2025-04-15 08:21:46 -07:00
mrp.h	…
ncsi.h	…
ndisc.h	net: replace ND_PRINTK with dynamic debug	2025-07-10 15:27:32 -07:00
neighbour.h	neighbour: Convert rwlock of struct neigh_table to spinlock.	2025-10-24 17:57:20 -07:00
neighbour_tables.h	neighbour: Create netdev->neighbour association	2024-11-09 13:22:57 -08:00
net_debug.h	Kbuild updates for v6.13	2024-11-30 13:41:50 -08:00
net_failover.h	…
net_namespace.h	netns: optimize netns cleaning by batching unhash_nsid calls	2026-02-06 20:01:31 -08:00
net_ratelimit.h	…
net_shaper.h	net-shapers: implement NL get operation	2024-10-10 08:30:22 -07:00
net_trackers.h	…
netdev_lock.h	Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net	2025-05-22 09:42:41 -07:00
netdev_netlink.h	net: add granular lock for the netdev netlink socket	2025-03-12 13:32:35 -07:00
netdev_queues.h	net: add queue config validation callback	2026-01-23 11:49:02 -08:00
netdev_rx_queue.h	net-sysfs: use rps_tag_ptr and remove metadata from rps_dev_flow_table	2026-03-04 16:54:10 -08:00
netevent.h	…
netkit.h	bpf, netkit: Add indirect call wrapper for fetching peer dev	2023-11-20 10:15:16 -08:00
netlabel.h	Networking changes for 6.13.	2024-11-21 08:28:08 -08:00
netlink.h	netlink: introduce type-checking attribute iteration for nlmsg	2025-07-02 15:39:04 -07:00
netmem.h	netmem: remove the pp fields from net_iov	2026-02-26 19:45:24 -08:00
netprio_cgroup.h	…
netrom.h	…
nexthop.h	ipv6: Protect nh->f6i_list with spinlock and flag.	2025-04-24 09:29:56 +02:00
nl802154.h	nl802154: fix some kernel-doc warnings	2025-10-20 17:13:40 -07:00
nsh.h	…
pfcp.h	net: pfcp: fix typo in message_priority field name	2025-06-13 18:17:08 -07:00
pie.h	…
ping.h	net: remove addr_len argument of recvmsg() handlers	2026-03-02 18:17:17 -08:00
pkt_cls.h	net: sched: fix TCF_LAYER_TRANSPORT handling in tcf_get_base_ptr()	2025-11-24 18:53:14 -08:00
pkt_sched.h	net/sched: don't use dynamic lockdep keys with clsact/ingress/noqueue	2026-02-05 09:32:45 -08:00
pptp.h	…
proto_memory.h	net: Allow opt-out from global protocol memory accounting.	2025-10-16 12:04:47 -07:00
protocol.h	ipv6: move tcp_ipv6_hash_secret and udp_ipv6_hash_secret to net_hotdata	2024-03-07 21:12:43 -08:00
psample.h	net: psample: fix flag being set in wrong skb	2024-07-11 18:11:31 -07:00
psnap.h	…
psp.h	psp: base PSP device support	2025-09-18 12:32:06 +02:00
raw.h	net: use NUMA drop counters for softnet_data.dropped	2025-09-14 11:35:17 -07:00
rawv6.h	…
red.h	net: sched: Correct spelling in headers	2024-08-26 09:37:23 -07:00
regulatory.h	net: Correct spelling in headers	2024-08-26 09:37:23 -07:00
request_sock.h	tcp: move __reqsk_free() out of line	2026-02-05 09:23:06 -08:00
rose.h	net: rose: convert 'use' field to refcount_t	2025-08-27 07:43:08 -07:00
route.h	net: use dst_dev_rcu() in sk_setup_caps()	2025-08-29 19:36:32 -07:00
rpl.h	…
rps-types.h	net: add rps_tag_ptr type and helpers	2026-03-04 16:54:09 -08:00
rps.h	net-sysfs: use rps_tag_ptr and remove metadata from rps_dev_flow_table	2026-03-04 16:54:10 -08:00
rsi_91x.h	…
rstreason.h	net: Retire DCCP socket.	2025-04-11 18:58:10 -07:00
rtnetlink.h	rtnetlink: Remove "net" from newlink params	2025-02-21 15:28:03 -08:00
rtnh.h	…
sch_generic.h	net/sched: do not reset queues in graft operations	2026-03-09 18:55:55 -07:00
sch_priv.h	net/sched: Export mq functions for reuse	2026-01-13 11:54:29 +01:00
scm.h	af_unix/scm: fix whitespace errors	2025-07-04 09:32:35 +02:00
secure_seq.h	tcp: secure_seq: add back ports to TS offset	2026-03-04 17:44:35 -08:00
seg6.h	ipv6: sr: restruct ifdefines	2024-05-30 18:29:38 -07:00
seg6_hmac.h	ipv6: sr: Prepare HMAC key ahead of time	2025-08-26 18:11:29 -07:00
seg6_local.h	seg6: Use nested-BH locking for seg6_bpf_srh_states.	2024-06-24 16:41:23 -07:00
selftests.h	net: selftests: export packet creation helpers for driver use	2025-11-06 13:38:11 +01:00
slhc_vj.h	…
smc.h	net/smc: bpf: Introduce generic hook for handshake flow	2025-11-10 11:19:41 -08:00
snmp.h	net: snmp: remove SNMP_MIB_SENTINEL	2025-09-08 18:06:21 -07:00
sock.h	net: remove addr_len argument of recvmsg() handlers	2026-03-02 18:17:17 -08:00
sock_reuseport.h	net: core: annotate socks of struct sock_reuseport with __counted_by	2024-08-02 17:16:59 -07:00
stp.h	…
strparser.h	strparser: Remove unused __strp_unpause	2025-05-05 16:48:12 -07:00
switchdev.h	net: bridge: switchdev: Skip MDB replays of deferred events on offload	2024-02-16 09:36:37 +00:00
tc_wrapper.h	net/sched: refine indirect call mitigation in tc_wrapper.h	2026-03-09 19:31:41 -07:00
tcp.h	tcp: inline tcp_chrono_start()	2026-03-09 19:34:00 -07:00
tcp_ao.h	tcp: Free TCP-AO/TCP-MD5 info/keys without RCU	2025-09-11 19:05:56 -07:00
tcp_ecn.h	tcp: accecn: add tcpi_ecn_mode and tcpi_option2 in tcp_info	2026-02-03 15:13:25 +01:00
tcp_states.h	tcp: Dump bound-only sockets in inet_diag.	2023-12-04 14:45:26 -08:00
tcx.h	bpf: Remove location field in tcx_link	2025-07-11 11:00:57 -07:00
timewait_sock.h	tcp: Remove timewait_sock_ops.twsk_destructor().	2025-08-25 17:53:35 -07:00
tipc.h	…
tls.h	Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net	2025-10-31 06:46:03 -07:00
tls_prot.h	…
tls_toe.h	…
transp_v6.h	…
tso.h	…
tun_proto.h	…
udp.h	net: fix off-by-one in udp_flow_src_port() / psp_write_headers()	2026-03-04 16:51:10 -08:00
udp_tunnel.h	geneve: expose gso partial features for tunnel offload	2026-01-23 11:31:14 -08:00
udplite.h	udplite: fix various data-races	2023-09-14 16:16:36 +02:00
vsock_addr.h	net: Convert proto_ops connect() callbacks to use sockaddr_unsized	2025-11-04 19:10:32 -08:00
vxlan.h	vxlan: Support MC routing in the underlay	2025-06-17 18:18:46 -07:00
wext.h	…
x25.h	net/x25: Remove unused x25_terminate_link()	2025-07-14 17:19:13 -07:00
x25device.h	…
xdp.h	bpf-next-for-netdev	2025-09-24 10:22:37 -07:00
xdp_priv.h	…
xdp_sock.h	xsk: add indirect call for xsk_destruct_skb	2025-11-11 10:21:08 +01:00
xdp_sock_drv.h	xsk: introduce helper to determine rxq->frag_size	2026-03-05 08:02:03 -08:00
xfrm.h	xfrm: reduce struct sec_path size	2026-02-10 20:21:48 -08:00
xsk_buff_pool.h	xsk: move cq_cached_prod_lock to avoid touching a cacheline in sending path	2026-01-15 10:07:45 +01:00