linux/include/net
Daniel Borkmann 8f61059a96 net: sctp: improve timer slack calculation for transport HBs
RFC4960, section 8.3 says:

  On an idle destination address that is allowed to heartbeat,
  it is recommended that a HEARTBEAT chunk is sent once per RTO
  of that destination address plus the protocol parameter
  'HB.interval', with jittering of +/- 50% of the RTO value,
  and exponential backoff of the RTO if the previous HEARTBEAT
  is unanswered.

Currently, we calculate jitter via sctp_jitter() function first,
and then add its result to the current RTO for the new timeout:

  TMO = RTO + (RAND() % RTO) - (RTO / 2)
              `------------------------^-=> sctp_jitter()

Instead, we can just simplify all this by directly calculating:

  TMO = (RTO / 2) + (RAND() % RTO)

With the help of prandom_u32_max(), we don't need to open code
our own global PRNG, but can instead just make use of the per
CPU implementation of prandom with better quality numbers. Also,
we can now spare us the conditional for divide by zero check
since no div or mod operation needs to be used. Note that
prandom_u32_max() won't emit the same result as a mod operation,
but we really don't care here as we only want to have a random
number scaled into RTO interval.

Note, exponential RTO backoff is handeled elsewhere, namely in
sctp_do_8_2_transport_strike().

Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-07-02 18:44:07 -07:00
..
9p 9pnet: p9_client->conn field is unused. Remove it. 2014-03-25 16:38:16 -05:00
bluetooth Bluetooth: Clearly distinguish mgmt LTK type from authenticated property 2014-05-23 11:24:04 -07:00
caif caif_hsi.h: Remove extern from function prototypes 2013-09-23 16:29:41 -04:00
irda include/net/: Fix FSF address in file headers 2013-12-06 12:37:56 -05:00
iucv af_iucv: fix recvmsg by replacing skb_pull() function 2013-04-08 17:16:57 -04:00
netfilter netfilter: nf_tables: use u32 for chain use counter 2014-06-16 13:07:44 +02:00
netns ipv4: make ip_local_reserved_ports per netns 2014-05-14 15:31:45 -04:00
nfc NFC: Add RAW socket type support for SOCKPROTO_RAW 2014-05-20 00:06:04 +02:00
phonet
sctp net: sctp: improve timer slack calculation for transport HBs 2014-07-02 18:44:07 -07:00
tc_act net_sched: act: hide struct tcf_common from API 2014-02-12 19:23:32 -05:00
6lowpan.h 6lowpan: include net/net_namespace.h on 6lowpan namepsace header 2014-04-20 18:18:55 -04:00
act_api.h net_sched: act: refuse to remove bound action outside 2014-02-12 19:23:32 -05:00
addrconf.h net: ipv6: Introduce ip6_sk_dst_hoplimit. 2014-04-30 13:31:26 -04:00
af_ieee802154.h ieee802154: add dgram sockopts for security control 2014-05-16 17:23:41 -04:00
af_rxrpc.h af_rxrpc.h: Remove extern from function prototypes 2013-07-31 17:50:01 -07:00
af_unix.h af_unix: improve STREAM behavior with fragmented memory 2013-08-10 01:16:44 -07:00
af_vsock.h vsock: Make transport the proto owner 2014-05-05 13:13:50 -04:00
ah.h
arp.h arp: make arp_invalidate static 2013-12-28 17:02:46 -05:00
atmclip.h
ax25.h ax25.h: Remove extern from function prototypes 2013-07-31 17:50:02 -07:00
ax88796.h
busy_poll.h sched, net: Fixup busy_loop_us_clock() 2014-01-13 17:39:11 +01:00
cfg80211-wext.h
cfg80211.h Merge git://git.kernel.org/pub/scm/linux/kernel/git/jberg/mac80211-next 2014-05-22 13:58:36 -04:00
checksum.h net: Allow csum_add to be provided in arch 2014-05-05 15:26:29 -04:00
cipso_ipv4.h cipso: cleanup cipso_v4_translate() when !CONFIG_NETLABEL 2013-12-10 17:56:54 -05:00
cls_cgroup.h cgroup: clean up cgroup_subsys names and initialization 2014-02-08 10:36:58 -05:00
codel.h net: introduce reciprocal_scale helper and convert users 2014-01-21 23:17:20 -08:00
compat.h compat.h: Remove extern from function prototypes 2013-09-20 14:49:32 -04:00
datalink.h net: Move prototype declaration to header file include/net/datalink.h from net/ipx/af_ipx.c 2014-02-09 17:32:50 -08:00
dcbevent.h include/net/: Fix FSF address in file headers 2013-12-06 12:37:56 -05:00
dcbnl.h include/net/: Fix FSF address in file headers 2013-12-06 12:37:56 -05:00
dn_dev.h dn_dev: add support for IFA_FLAGS nl attribute 2013-12-10 21:50:00 -05:00
dn_fib.h decnet (dn*.h): Remove extern from function prototypes 2013-09-20 14:49:32 -04:00
dn_neigh.h decnet (dn*.h): Remove extern from function prototypes 2013-09-20 14:49:32 -04:00
dn_nsp.h decnet (dn*.h): Remove extern from function prototypes 2013-09-20 14:49:32 -04:00
dn_route.h net: Move prototype declaration to appropriate header file from decnet/af_decnet.c 2014-02-09 17:32:49 -08:00
dn.h net: Move prototype declaration to header file include/net/dn.h from net/decnet/af_decnet.c 2014-02-09 17:32:49 -08:00
dsa.h net: dsa: add ds_to_priv 2014-04-30 13:31:25 -04:00
dsfield.h ipv6: Optimize ipv6_change_dsfield(). 2013-01-09 23:59:53 -08:00
dst_ops.h
dst.h ipv4: add a sock pointer to dst->output() path. 2014-04-15 13:47:15 -04:00
esp.h net: move pskb_put() to core code 2013-11-07 19:28:58 -05:00
ethoc.h net: ethoc: set up MII management bus clock 2014-02-04 20:19:51 -08:00
fib_rules.h fib_rules.h: Remove extern from function prototypes 2013-09-20 14:49:33 -04:00
firewire.h firewire net, ipv4 arp: Extend hardware address and remove driver-level packet inspection. 2013-03-26 12:32:13 -04:00
flow_keys.h flow_keys: Record IP layer protocol in skb_flow_dissect() 2014-06-23 14:32:19 -07:00
flow.h ipv4, fib: pass LOOPBACK_IFINDEX instead of 0 to flowi4_iif 2014-04-16 15:05:11 -04:00
flowcache.h flowcache: Make flow cache name space aware 2014-02-12 07:02:11 +01:00
garp.h garp.h: Remove extern from function prototypes 2013-09-20 14:49:33 -04:00
gen_stats.h gen_stats.h: Remove extern from function prototypes 2013-09-20 14:49:33 -04:00
genetlink.h genl: Add genlmsg_new_unicast() for unicast message allocation 2014-01-06 15:51:53 -08:00
gre.h gre: Call gso_make_checksum 2014-06-04 22:46:38 -07:00
gro_cells.h gro: Fix kcalloc argument order 2013-01-27 22:46:33 -05:00
icmp.h icmp.h: Remove extern from function prototypes 2013-09-20 14:49:33 -04:00
ieee80211_radiotap.h mac80211: propagate STBC / LDPC flags to radiotap 2014-02-06 09:34:58 +01:00
ieee802154_netdev.h ieee802154, mac802154: implement devkey record option 2014-05-16 17:23:42 -04:00
ieee802154.h ieee802154: add definitions for link-layer security and header functions 2014-05-15 15:51:42 -04:00
if_inet6.h ipv6: move DAD and addrconf_verify processing to workqueue 2014-03-28 16:54:50 -04:00
inet6_connection_sock.h ipv4: add a sock pointer to ip_queue_xmit() 2014-04-15 12:58:34 -04:00
inet6_hashtables.h ipv6: split inet6_ehashfn to hash functions per compilation unit 2013-10-19 19:45:34 -04:00
inet_common.h inet*.h: Remove extern from function prototypes 2013-09-21 14:01:38 -04:00
inet_connection_sock.h ipv4: add a sock pointer to ip_queue_xmit() 2014-04-15 12:58:34 -04:00
inet_ecn.h tunnel: fix RFC number in comment for INET_ECN_decapsulate() 2014-05-07 15:30:52 -04:00
inet_frag.h inet: remove old fragmentation hash initializing 2013-10-23 17:01:41 -04:00
inet_hashtables.h net: Use a more standard macro for INET_ADDR_COOKIE 2014-05-14 16:07:23 -04:00
inet_sock.h net: remove inet6_reqsk_alloc 2014-06-27 15:53:35 -07:00
inet_timewait_sock.h inet: move ipv6only in sock_common 2014-07-01 23:46:21 -07:00
inetpeer.h Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2014-06-03 23:32:12 -07:00
ip6_checksum.h udp: Generic functions to set checksum 2014-06-04 22:46:38 -07:00
ip6_fib.h ipv6: do not overwrite inetpeer metrics prematurely 2014-03-27 15:09:07 -04:00
ip6_route.h Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2014-05-24 00:32:30 -04:00
ip6_tunnel.h net: unify the pcpu_tstats and br_cpu_netstats as one 2014-01-04 20:10:24 -05:00
ip_fib.h ip*.h: Remove extern from function prototypes 2013-09-21 14:01:38 -04:00
ip_tunnels.h ipv4: add a sock pointer to dst->output() path. 2014-04-15 13:47:15 -04:00
ip_vs.h arch: Mass conversion of smp_mb__*() 2014-04-18 14:20:48 +02:00
ip.h inetpeer: get rid of ip_id_count 2014-06-02 11:00:41 -07:00
ipcomp.h
ipconfig.h
ipv6.h inetpeer: get rid of ip_id_count 2014-06-02 11:00:41 -07:00
ipx.h net: Move prototype declaration to header file include/net/ipx.h from net/ipx/af_ipx.c 2014-02-09 17:32:50 -08:00
iw_handler.h iw_handler.h: Remove extern from function prototypes 2013-09-21 14:01:39 -04:00
lapb.h lapb.h: Remove extern from function prototypes 2013-09-21 14:01:38 -04:00
lib80211.h hostap: Don't use create_proc_read_entry() 2013-04-29 15:41:56 -04:00
llc_c_ac.h llc*.h: Remove extern from function prototypes 2013-09-21 14:01:38 -04:00
llc_c_ev.h llc*.h: Remove extern from function prototypes 2013-09-21 14:01:38 -04:00
llc_c_st.h
llc_conn.h llc*.h: Remove extern from function prototypes 2013-09-21 14:01:38 -04:00
llc_if.h llc*.h: Remove extern from function prototypes 2013-09-21 14:01:38 -04:00
llc_pdu.h net: llc: fix order of evaluation in llc_conn_ac_inc_vr_by_1 2014-01-01 22:22:43 -05:00
llc_s_ac.h llc*.h: Remove extern from function prototypes 2013-09-21 14:01:38 -04:00
llc_s_ev.h llc*.h: Remove extern from function prototypes 2013-09-21 14:01:38 -04:00
llc_s_st.h
llc_sap.h llc*.h: Remove extern from function prototypes 2013-09-21 14:01:38 -04:00
llc.h llc: make lock static 2014-01-03 20:56:48 -05:00
mac80211.h mac80211: add a single-transaction driver op to switch contexts 2014-05-26 11:04:41 +02:00
mac802154.h ieee802154: add header structs with endiannes and operations 2014-03-14 22:15:26 -04:00
mip6.h include/net/: Fix FSF address in file headers 2013-12-06 12:37:56 -05:00
mld.h net: ipv6: mld: get rid of MLDV2_MRC and simplify calculation 2013-09-04 14:53:20 -04:00
mrp.h Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2013-10-01 17:06:14 -04:00
ndisc.h ndisc.h: Remove extern from function prototypes 2013-09-21 14:01:39 -04:00
neighbour.h neigh: use NEIGH_VAR_INIT in ndo_neigh_setup functions. 2014-01-16 11:31:58 -08:00
net_namespace.h 6lowpan: nuke net_ieee802154_lowpan() accessor when 6lowpan is disabled 2014-04-24 12:36:00 -04:00
net_ratelimit.h
netdma.h
netevent.h netevent/netlink.h: Remove extern from function prototypes 2013-09-21 14:01:39 -04:00
netlabel.h Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2014-01-25 11:17:34 -08:00
netlink.h netevent/netlink.h: Remove extern from function prototypes 2013-09-21 14:01:39 -04:00
netprio_cgroup.h cgroup: clean up cgroup_subsys names and initialization 2014-02-08 10:36:58 -05:00
netrom.h netrom.h: Remove extern from function prototypes 2013-09-21 14:01:39 -04:00
nexthop.h
nl802154.h ieee802154: use ieee802154_addr instead of *_sa variants 2014-03-14 22:15:26 -04:00
p8022.h p8022.h: Remove extern from function prototypes 2013-09-21 14:01:39 -04:00
ping.h ipv6: make IPV6_RECVPKTINFO work for ipv4 datagrams 2014-01-19 19:53:18 -08:00
pkt_cls.h sched, cls: check if we could overwrite actions when changing a filter 2014-04-27 23:42:39 -04:00
pkt_sched.h net_sched: drr: warn when qdisc is not work conserving 2014-06-11 15:50:59 -07:00
protocol.h net: Eliminate no_check from protosw 2014-05-23 16:28:53 -04:00
psnap.h psnap.h: Remove extern from function prototypes 2013-09-23 01:51:08 -04:00
raw.h raw/rawv6.h: Remove extern from function prototypes 2013-09-23 01:51:08 -04:00
rawv6.h raw/rawv6.h: Remove extern from function prototypes 2013-09-23 01:51:08 -04:00
red.h reciprocal_divide: update/correction of the algorithm 2014-01-21 23:17:20 -08:00
regulatory.h cfg80211: Enable GO operation on additional channels 2014-04-09 10:55:34 +02:00
request_sock.h inet: includes a sock_common in request_sock 2013-10-10 00:08:07 -04:00
rose.h rose.h: Remove extern from function prototypes 2013-09-23 01:51:08 -04:00
route.h ipv4: remove ip_rt_dump from route.c 2014-03-24 12:45:01 -04:00
rtnetlink.h rtnl: make ifla_policy static 2014-02-18 18:15:42 -05:00
sch_generic.h flow_keys: Record IP layer protocol in skb_flow_dissect() 2014-06-23 14:32:19 -07:00
scm.h scm.h: Remove extern from function prototypes 2013-09-23 01:51:09 -04:00
secure_seq.h inetpeer: get rid of ip_id_count 2014-06-02 11:00:41 -07:00
slhc_vj.h
snmp.h net: clean up snmp stats code 2014-05-07 16:06:05 -04:00
sock.h inet: move ipv6only in sock_common 2014-07-01 23:46:21 -07:00
Space.h drivers: net: Include new header file in sbni.c 2013-12-19 18:51:20 -05:00
stp.h stp.h: Remove extern from function prototypes 2013-09-23 01:51:09 -04:00
tcp_memcontrol.h tcp_memcontrol: Kill struct tcp_memcontrol 2013-10-21 18:43:02 -04:00
tcp_states.h
tcp.h tcp: add tcp_conn_request 2014-06-27 15:53:37 -07:00
timewait_sock.h
transp_v6.h ipv6: make IPV6_RECVPKTINFO work for ipv4 datagrams 2014-01-19 19:53:18 -08:00
tso.h net: Add a software TSO helper API 2014-05-22 14:57:15 -04:00
udp.h udp: call __skb_checksum_complete when doing full checksum 2014-06-15 01:00:49 -07:00
udplite.h udplite.h: Remove extern from function prototypes 2013-09-23 16:29:40 -04:00
vsock_addr.h VSOCK: Move af_vsock.h and vsock_addr.h to include/net 2013-07-27 22:14:06 -07:00
vxlan.h vxlan: Add support for UDP checksums (v4 sending, v6 zero csums) 2014-06-04 22:46:39 -07:00
wext.h wext.h: Remove extern from function prototypes 2013-09-23 16:29:40 -04:00
wimax.h wimax: Spelling s/than/that/, wording s/destinatary/recipient/ 2014-05-05 15:37:55 +02:00
wpan-phy.h ieee802154: add netlink APIs for smartMAC configuration 2014-02-17 16:42:39 -05:00
x25.h x25.h: Remove extern from function prototypes 2013-09-23 16:29:41 -04:00
x25device.h
xfrm.h xfrm: Remove useless xfrm_audit struct. 2014-04-23 08:21:04 +02:00