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diff --git a/Documentation/networking/operstates.txt b/Documentation/networking/operstates.txt
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+
+1. Introduction
+
+Linux distinguishes between administrative and operational state of an
+interface. Admininstrative state is the result of "ip link set dev
+<dev> up or down" and reflects whether the administrator wants to use
+the device for traffic.
+
+However, an interface is not usable just because the admin enabled it
+- ethernet requires to be plugged into the switch and, depending on
+a site's networking policy and configuration, an 802.1X authentication
+to be performed before user data can be transferred. Operational state
+shows the ability of an interface to transmit this user data.
+
+Thanks to 802.1X, userspace must be granted the possibility to
+influence operational state. To accommodate this, operational state is
+split into two parts: Two flags that can be set by the driver only, and
+a RFC2863 compatible state that is derived from these flags, a policy,
+and changeable from userspace under certain rules.
+
+
+2. Querying from userspace
+
+Both admin and operational state can be queried via the netlink
+operation RTM_GETLINK. It is also possible to subscribe to RTMGRP_LINK
+to be notified of updates. This is important for setting from userspace.
+
+These values contain interface state:
+
+ifinfomsg::if_flags & IFF_UP:
+ Interface is admin up
+ifinfomsg::if_flags & IFF_RUNNING:
+ Interface is in RFC2863 operational state UP or UNKNOWN. This is for
+ backward compatibility, routing daemons, dhcp clients can use this
+ flag to determine whether they should use the interface.
+ifinfomsg::if_flags & IFF_LOWER_UP:
+ Driver has signaled netif_carrier_on()
+ifinfomsg::if_flags & IFF_DORMANT:
+ Driver has signaled netif_dormant_on()
+
+These interface flags can also be queried without netlink using the
+SIOCGIFFLAGS ioctl.
+
+TLV IFLA_OPERSTATE
+
+contains RFC2863 state of the interface in numeric representation:
+
+IF_OPER_UNKNOWN (0):
+ Interface is in unknown state, neither driver nor userspace has set
+ operational state. Interface must be considered for user data as
+ setting operational state has not been implemented in every driver.
+IF_OPER_NOTPRESENT (1):
+ Unused in current kernel (notpresent interfaces normally disappear),
+ just a numerical placeholder.
+IF_OPER_DOWN (2):
+ Interface is unable to transfer data on L1, f.e. ethernet is not
+ plugged or interface is ADMIN down.
+IF_OPER_LOWERLAYERDOWN (3):
+ Interfaces stacked on an interface that is IF_OPER_DOWN show this
+ state (f.e. VLAN).
+IF_OPER_TESTING (4):
+ Unused in current kernel.
+IF_OPER_DORMANT (5):
+ Interface is L1 up, but waiting for an external event, f.e. for a
+ protocol to establish. (802.1X)
+IF_OPER_UP (6):
+ Interface is operational up and can be used.
+
+This TLV can also be queried via sysfs.
+
+TLV IFLA_LINKMODE
+
+contains link policy. This is needed for userspace interaction
+described below.
+
+This TLV can also be queried via sysfs.
+
+
+3. Kernel driver API
+
+Kernel drivers have access to two flags that map to IFF_LOWER_UP and
+IFF_DORMANT. These flags can be set from everywhere, even from
+interrupts. It is guaranteed that only the driver has write access,
+however, if different layers of the driver manipulate the same flag,
+the driver has to provide the synchronisation needed.
+
+__LINK_STATE_NOCARRIER, maps to !IFF_LOWER_UP:
+
+The driver uses netif_carrier_on() to clear and netif_carrier_off() to
+set this flag. On netif_carrier_off(), the scheduler stops sending
+packets. The name 'carrier' and the inversion are historical, think of
+it as lower layer.
+
+netif_carrier_ok() can be used to query that bit.
+
+__LINK_STATE_DORMANT, maps to IFF_DORMANT:
+
+Set by the driver to express that the device cannot yet be used
+because some driver controlled protocol establishment has to
+complete. Corresponding functions are netif_dormant_on() to set the
+flag, netif_dormant_off() to clear it and netif_dormant() to query.
+
+On device allocation, networking core sets the flags equivalent to
+netif_carrier_ok() and !netif_dormant().
+
+
+Whenever the driver CHANGES one of these flags, a workqueue event is
+scheduled to translate the flag combination to IFLA_OPERSTATE as
+follows:
+
+!netif_carrier_ok():
+ IF_OPER_LOWERLAYERDOWN if the interface is stacked, IF_OPER_DOWN
+ otherwise. Kernel can recognise stacked interfaces because their
+ ifindex != iflink.
+
+netif_carrier_ok() && netif_dormant():
+ IF_OPER_DORMANT
+
+netif_carrier_ok() && !netif_dormant():
+ IF_OPER_UP if userspace interaction is disabled. Otherwise
+ IF_OPER_DORMANT with the possibility for userspace to initiate the
+ IF_OPER_UP transition afterwards.
+
+
+4. Setting from userspace
+
+Applications have to use the netlink interface to influence the
+RFC2863 operational state of an interface. Setting IFLA_LINKMODE to 1
+via RTM_SETLINK instructs the kernel that an interface should go to
+IF_OPER_DORMANT instead of IF_OPER_UP when the combination
+netif_carrier_ok() && !netif_dormant() is set by the
+driver. Afterwards, the userspace application can set IFLA_OPERSTATE
+to IF_OPER_DORMANT or IF_OPER_UP as long as the driver does not set
+netif_carrier_off() or netif_dormant_on(). Changes made by userspace
+are multicasted on the netlink group RTMGRP_LINK.
+
+So basically a 802.1X supplicant interacts with the kernel like this:
+
+-subscribe to RTMGRP_LINK
+-set IFLA_LINKMODE to 1 via RTM_SETLINK
+-query RTM_GETLINK once to get initial state
+-if initial flags are not (IFF_LOWER_UP && !IFF_DORMANT), wait until
+ netlink multicast signals this state
+-do 802.1X, eventually abort if flags go down again
+-send RTM_SETLINK to set operstate to IF_OPER_UP if authentication
+ succeeds, IF_OPER_DORMANT otherwise
+-see how operstate and IFF_RUNNING is echoed via netlink multicast
+-set interface back to IF_OPER_DORMANT if 802.1X reauthentication
+ fails
+-restart if kernel changes IFF_LOWER_UP or IFF_DORMANT flag
+
+if supplicant goes down, bring back IFLA_LINKMODE to 0 and
+IFLA_OPERSTATE to a sane value.
+
+A routing daemon or dhcp client just needs to care for IFF_RUNNING or
+waiting for operstate to go IF_OPER_UP/IF_OPER_UNKNOWN before
+considering the interface / querying a DHCP address.
+
+
+For technical questions and/or comments please e-mail to Stefan Rompf
+(stefan at loplof.de).
diff --git a/Documentation/networking/xfrm_sync.txt b/Documentation/networking/xfrm_sync.txt
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index 00000000000..8be626f7c0b
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+++ b/Documentation/networking/xfrm_sync.txt
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+
+The sync patches work is based on initial patches from
+Krisztian <hidden@balabit.hu> and others and additional patches
+from Jamal <hadi@cyberus.ca>.
+
+The end goal for syncing is to be able to insert attributes + generate
+events so that the an SA can be safely moved from one machine to another
+for HA purposes.
+The idea is to synchronize the SA so that the takeover machine can do
+the processing of the SA as accurate as possible if it has access to it.
+
+We already have the ability to generate SA add/del/upd events.
+These patches add ability to sync and have accurate lifetime byte (to
+ensure proper decay of SAs) and replay counters to avoid replay attacks
+with as minimal loss at failover time.
+This way a backup stays as closely uptodate as an active member.
+
+Because the above items change for every packet the SA receives,
+it is possible for a lot of the events to be generated.
+For this reason, we also add a nagle-like algorithm to restrict
+the events. i.e we are going to set thresholds to say "let me
+know if the replay sequence threshold is reached or 10 secs have passed"
+These thresholds are set system-wide via sysctls or can be updated
+per SA.
+
+The identified items that need to be synchronized are:
+- the lifetime byte counter
+note that: lifetime time limit is not important if you assume the failover
+machine is known ahead of time since the decay of the time countdown
+is not driven by packet arrival.
+- the replay sequence for both inbound and outbound
+
+1) Message Structure
+----------------------
+
+nlmsghdr:aevent_id:optional-TLVs.
+
+The netlink message types are:
+
+XFRM_MSG_NEWAE and XFRM_MSG_GETAE.
+
+A XFRM_MSG_GETAE does not have TLVs.
+A XFRM_MSG_NEWAE will have at least two TLVs (as is
+discussed further below).
+
+aevent_id structure looks like:
+
+   struct xfrm_aevent_id {
+             struct xfrm_usersa_id           sa_id;
+             __u32                           flags;
+   };
+
+xfrm_usersa_id in this message layout identifies the SA.
+
+flags are used to indicate different things. The possible
+flags are:
+        XFRM_AE_RTHR=1, /* replay threshold*/
+        XFRM_AE_RVAL=2, /* replay value */
+        XFRM_AE_LVAL=4, /* lifetime value */
+        XFRM_AE_ETHR=8, /* expiry timer threshold */
+        XFRM_AE_CR=16, /* Event cause is replay update */
+        XFRM_AE_CE=32, /* Event cause is timer expiry */
+        XFRM_AE_CU=64, /* Event cause is policy update */
+
+How these flags are used is dependent on the direction of the
+message (kernel<->user) as well the cause (config, query or event).
+This is described below in the different messages.
+
+The pid will be set appropriately in netlink to recognize direction
+(0 to the kernel and pid = processid that created the event
+when going from kernel to user space)
+
+A program needs to subscribe to multicast group XFRMNLGRP_AEVENTS
+to get notified of these events.
+
+2) TLVS reflect the different parameters:
+-----------------------------------------
+
+a) byte value (XFRMA_LTIME_VAL)
+This TLV carries the running/current counter for byte lifetime since
+last event.
+
+b)replay value (XFRMA_REPLAY_VAL)
+This TLV carries the running/current counter for replay sequence since
+last event.
+
+c)replay threshold (XFRMA_REPLAY_THRESH)
+This TLV carries the threshold being used by the kernel to trigger events
+when the replay sequence is exceeded.
+
+d) expiry timer (XFRMA_ETIMER_THRESH)
+This is a timer value in milliseconds which is used as the nagle
+value to rate limit the events.
+
+3) Default configurations for the parameters:
+----------------------------------------------
+
+By default these events should be turned off unless there is
+at least one listener registered to listen to the multicast
+group XFRMNLGRP_AEVENTS.
+
+Programs installing SAs will need to specify the two thresholds, however,
+in order to not change existing applications such as racoon
+we also provide default threshold values for these different parameters
+in case they are not specified.
+
+the two sysctls/proc entries are:
+a) /proc/sys/net/core/sysctl_xfrm_aevent_etime
+used to provide default values for the XFRMA_ETIMER_THRESH in incremental
+units of time of 100ms. The default is 10 (1 second)
+
+b) /proc/sys/net/core/sysctl_xfrm_aevent_rseqth
+used to provide default values for XFRMA_REPLAY_THRESH parameter
+in incremental packet count. The default is two packets.
+
+4) Message types
+----------------
+
+a) XFRM_MSG_GETAE issued by user-->kernel.
+XFRM_MSG_GETAE does not carry any TLVs.
+The response is a XFRM_MSG_NEWAE which is formatted based on what
+XFRM_MSG_GETAE queried for.
+The response will always have XFRMA_LTIME_VAL and XFRMA_REPLAY_VAL TLVs.
+*if XFRM_AE_RTHR flag is set, then XFRMA_REPLAY_THRESH is also retrieved
+*if XFRM_AE_ETHR flag is set, then XFRMA_ETIMER_THRESH is also retrieved
+
+b) XFRM_MSG_NEWAE is issued by either user space to configure
+or kernel to announce events or respond to a XFRM_MSG_GETAE.
+
+i) user --> kernel to configure a specific SA.
+any of the values or threshold parameters can be updated by passing the
+appropriate TLV.
+A response is issued back to the sender in user space to indicate success
+or failure.
+In the case of success, additionally an event with
+XFRM_MSG_NEWAE is also issued to any listeners as described in iii).
+
+ii) kernel->user direction as a response to XFRM_MSG_GETAE
+The response will always have XFRMA_LTIME_VAL and XFRMA_REPLAY_VAL TLVs.
+The threshold TLVs will be included if explicitly requested in
+the XFRM_MSG_GETAE message.
+
+iii) kernel->user to report as event if someone sets any values or
+thresholds for an SA using XFRM_MSG_NEWAE (as described in #i above).
+In such a case XFRM_AE_CU flag is set to inform the user that
+the change happened as a result of an update.
+The message will always have XFRMA_LTIME_VAL and XFRMA_REPLAY_VAL TLVs.
+
+iv) kernel->user to report event when replay threshold or a timeout
+is exceeded.
+In such a case either XFRM_AE_CR (replay exceeded) or XFRM_AE_CE (timeout
+happened) is set to inform the user what happened.
+Note the two flags are mutually exclusive.
+The message will always have XFRMA_LTIME_VAL and XFRMA_REPLAY_VAL TLVs.
+
+Exceptions to threshold settings
+--------------------------------
+
+If you have an SA that is getting hit by traffic in bursts such that
+there is a period where the timer threshold expires with no packets
+seen, then an odd behavior is seen as follows:
+The first packet arrival after a timer expiry will trigger a timeout
+aevent; i.e we dont wait for a timeout period or a packet threshold
+to be reached. This is done for simplicity and efficiency reasons.
+
+-JHS