1 files changed, 81 insertions, 67 deletions

diff --git a/Documentation/networking/ip-sysctl.txt b/Documentation/networking/ip-sysctl.txt
index c7712787933c..ec5de02f543f 100644
--- a/Documentation/networking/ip-sysctl.txt
+++ b/Documentation/networking/ip-sysctl.txt
@@ -2,7 +2,7 @@
 
 ip_forward - BOOLEAN
         0 - disabled (default)
-        not 0 - enabled 
+        not 0 - enabled
 
         Forward Packets between interfaces.
 
@@ -36,49 +36,49 @@ rt_cache_rebuild_count - INTEGER
 IP Fragmentation:
 
 ipfrag_high_thresh - INTEGER
-        Maximum memory used to reassemble IP fragments. When 
+        Maximum memory used to reassemble IP fragments. When
         ipfrag_high_thresh bytes of memory is allocated for this purpose,
         the fragment handler will toss packets until ipfrag_low_thresh
         is reached.
-        
+
 ipfrag_low_thresh - INTEGER
-        See ipfrag_high_thresh  
+        See ipfrag_high_thresh
 
 ipfrag_time - INTEGER
-        Time in seconds to keep an IP fragment in memory.       
+        Time in seconds to keep an IP fragment in memory.
 
 ipfrag_secret_interval - INTEGER
-        Regeneration interval (in seconds) of the hash secret (or lifetime 
+        Regeneration interval (in seconds) of the hash secret (or lifetime
         for the hash secret) for IP fragments.
         Default: 600
 
 ipfrag_max_dist - INTEGER
-        ipfrag_max_dist is a non-negative integer value which defines the 
-        maximum "disorder" which is allowed among fragments which share a 
-        common IP source address. Note that reordering of packets is 
-        not unusual, but if a large number of fragments arrive from a source 
-        IP address while a particular fragment queue remains incomplete, it 
-        probably indicates that one or more fragments belonging to that queue 
-        have been lost. When ipfrag_max_dist is positive, an additional check 
-        is done on fragments before they are added to a reassembly queue - if 
-        ipfrag_max_dist (or more) fragments have arrived from a particular IP 
-        address between additions to any IP fragment queue using that source 
-        address, it's presumed that one or more fragments in the queue are 
-        lost. The existing fragment queue will be dropped, and a new one 
+        ipfrag_max_dist is a non-negative integer value which defines the
+        maximum "disorder" which is allowed among fragments which share a
+        common IP source address. Note that reordering of packets is
+        not unusual, but if a large number of fragments arrive from a source
+        IP address while a particular fragment queue remains incomplete, it
+        probably indicates that one or more fragments belonging to that queue
+        have been lost. When ipfrag_max_dist is positive, an additional check
+        is done on fragments before they are added to a reassembly queue - if
+        ipfrag_max_dist (or more) fragments have arrived from a particular IP
+        address between additions to any IP fragment queue using that source
+        address, it's presumed that one or more fragments in the queue are
+        lost. The existing fragment queue will be dropped, and a new one
         started. An ipfrag_max_dist value of zero disables this check.
 
         Using a very small value, e.g. 1 or 2, for ipfrag_max_dist can
         result in unnecessarily dropping fragment queues when normal
-        reordering of packets occurs, which could lead to poor application 
-        performance. Using a very large value, e.g. 50000, increases the 
-        likelihood of incorrectly reassembling IP fragments that originate 
+        reordering of packets occurs, which could lead to poor application
+        performance. Using a very large value, e.g. 50000, increases the
+        likelihood of incorrectly reassembling IP fragments that originate
         from different IP datagrams, which could result in data corruption.
         Default: 64
 
 INET peer storage:
 
 inet_peer_threshold - INTEGER
-        The approximate size of the storage.  Starting from this threshold      
+        The approximate size of the storage.  Starting from this threshold
         entries will be thrown aggressively.  This threshold also determines
         entries' time-to-live and time intervals between garbage collection
         passes.  More entries, less time-to-live, less GC interval.
@@ -105,7 +105,7 @@ inet_peer_gc_maxtime - INTEGER
         in effect under low (or absent) memory pressure on the pool.
         Measured in seconds.
 
-TCP variables: 
+TCP variables:
 
 somaxconn - INTEGER
         Limit of socket listen() backlog, known in userspace as SOMAXCONN.
@@ -310,7 +310,7 @@ tcp_orphan_retries - INTEGER
 
 tcp_reordering - INTEGER
         Maximal reordering of packets in a TCP stream.
-        Default: 3      
+        Default: 3
 
 tcp_retrans_collapse - BOOLEAN
         Bug-to-bug compatibility with some broken printers.
@@ -521,7 +521,7 @@ IP Variables:
 
 ip_local_port_range - 2 INTEGERS
         Defines the local port range that is used by TCP and UDP to
-        choose the local port. The first number is the first, the 
+        choose the local port. The first number is the first, the
         second the last local port number. Default value depends on
         amount of memory available on the system:
         > 128Mb 32768-61000
@@ -594,12 +594,12 @@ icmp_errors_use_inbound_ifaddr - BOOLEAN
 
         If zero, icmp error messages are sent with the primary address of
         the exiting interface.
- 
+
         If non-zero, the message will be sent with the primary address of
         the interface that received the packet that caused the icmp error.
         This is the behaviour network many administrators will expect from
         a router. And it can make debugging complicated network layouts
-        much easier. 
+        much easier.
 
         Note that if no primary address exists for the interface selected,
         then the primary address of the first non-loopback interface that
@@ -611,7 +611,7 @@ igmp_max_memberships - INTEGER
         Change the maximum number of multicast groups we can subscribe to.
         Default: 20
 
-conf/interface/*  changes special settings per interface (where "interface" is 
+conf/interface/*  changes special settings per interface (where "interface" is
                   the name of your network interface)
 conf/all/*        is special, changes the settings for all interfaces
 
@@ -625,11 +625,11 @@ log_martians - BOOLEAN
 accept_redirects - BOOLEAN
         Accept ICMP redirect messages.
         accept_redirects for the interface will be enabled if:
-        - both conf/{all,interface}/accept_redirects are TRUE in the case forwarding
-          for the interface is enabled
+        - both conf/{all,interface}/accept_redirects are TRUE in the case
+          forwarding for the interface is enabled
         or
-        - at least one of conf/{all,interface}/accept_redirects is TRUE in the case
-          forwarding for the interface is disabled
+        - at least one of conf/{all,interface}/accept_redirects is TRUE in the
+          case forwarding for the interface is disabled
         accept_redirects for the interface will be disabled otherwise
         default TRUE (host)
                 FALSE (router)
@@ -640,8 +640,8 @@ forwarding - BOOLEAN
 mc_forwarding - BOOLEAN
         Do multicast routing. The kernel needs to be compiled with CONFIG_MROUTE
         and a multicast routing daemon is required.
-        conf/all/mc_forwarding must also be set to TRUE to enable multicast routing
-        for the interface
+        conf/all/mc_forwarding must also be set to TRUE to enable multicast
+        routing for the interface
 
 medium_id - INTEGER
         Integer value used to differentiate the devices by the medium they
@@ -649,7 +649,7 @@ medium_id - INTEGER
         the broadcast packets are received only on one of them.
         The default value 0 means that the device is the only interface
         to its medium, value of -1 means that medium is not known.
-        
+
         Currently, it is used to change the proxy_arp behavior:
         the proxy_arp feature is enabled for packets forwarded between
         two devices attached to different media.
@@ -699,16 +699,22 @@ accept_source_route - BOOLEAN
         default TRUE (router)
                 FALSE (host)
 
-rp_filter - BOOLEAN
-        1 - do source validation by reversed path, as specified in RFC1812
-            Recommended option for single homed hosts and stub network
-            routers. Could cause troubles for complicated (not loop free)
-            networks running a slow unreliable protocol (sort of RIP),
-            or using static routes.
-
+rp_filter - INTEGER
         0 - No source validation.
-
-        conf/all/rp_filter must also be set to TRUE to do source validation
+        1 - Strict mode as defined in RFC3704 Strict Reverse Path
+            Each incoming packet is tested against the FIB and if the interface
+            is not the best reverse path the packet check will fail.
+            By default failed packets are discarded.
+        2 - Loose mode as defined in RFC3704 Loose Reverse Path
+            Each incoming packet's source address is also tested against the FIB
+            and if the source address is not reachable via any interface
+            the packet check will fail.
+
+        Current recommended practice in RFC3704 is to enable strict mode
+        to prevent IP spoofing from DDos attacks. If using asymmetric routing
+        or other complicated routing, then loose mode is recommended.
+
+        conf/all/rp_filter must also be set to non-zero to do source validation
         on the interface
 
         Default value is 0. Note that some distributions enable it
@@ -782,6 +788,12 @@ arp_ignore - INTEGER
         The max value from conf/{all,interface}/arp_ignore is used
         when ARP request is received on the {interface}
 
+arp_notify - BOOLEAN
+        Define mode for notification of address and device changes.
+        0 - (default): do nothing
+        1 - Generate gratuitous arp replies when device is brought up
+            or hardware address changes.
+
 arp_accept - BOOLEAN
         Define behavior when gratuitous arp replies are received:
         0 - drop gratuitous arp frames
@@ -823,7 +835,7 @@ apply to IPv6 [XXX?].
 
 bindv6only - BOOLEAN
         Default value for IPV6_V6ONLY socket option,
-        which restricts use of the IPv6 socket to IPv6 communication 
+        which restricts use of the IPv6 socket to IPv6 communication
         only.
                 TRUE: disable IPv4-mapped address feature
                 FALSE: enable IPv4-mapped address feature
@@ -833,19 +845,19 @@ bindv6only - BOOLEAN
 IPv6 Fragmentation:
 
 ip6frag_high_thresh - INTEGER
-        Maximum memory used to reassemble IPv6 fragments. When 
+        Maximum memory used to reassemble IPv6 fragments. When
         ip6frag_high_thresh bytes of memory is allocated for this purpose,
         the fragment handler will toss packets until ip6frag_low_thresh
         is reached.
-        
+
 ip6frag_low_thresh - INTEGER
-        See ip6frag_high_thresh 
+        See ip6frag_high_thresh
 
 ip6frag_time - INTEGER
         Time in seconds to keep an IPv6 fragment in memory.
 
 ip6frag_secret_interval - INTEGER
-        Regeneration interval (in seconds) of the hash secret (or lifetime 
+        Regeneration interval (in seconds) of the hash secret (or lifetime
         for the hash secret) for IPv6 fragments.
         Default: 600
 
@@ -854,17 +866,17 @@ conf/default/*:
 
 
 conf/all/*:
-        Change all the interface-specific settings.  
+        Change all the interface-specific settings.
 
         [XXX:  Other special features than forwarding?]
 
 conf/all/forwarding - BOOLEAN
-        Enable global IPv6 forwarding between all interfaces.  
+        Enable global IPv6 forwarding between all interfaces.
 
-        IPv4 and IPv6 work differently here; e.g. netfilter must be used 
+        IPv4 and IPv6 work differently here; e.g. netfilter must be used
         to control which interfaces may forward packets and which not.
 
-        This also sets all interfaces' Host/Router setting 
+        This also sets all interfaces' Host/Router setting
         'forwarding' to the specified value.  See below for details.
 
         This referred to as global forwarding.
@@ -875,12 +887,12 @@ proxy_ndp - BOOLEAN
 conf/interface/*:
         Change special settings per interface.
 
-        The functional behaviour for certain settings is different 
+        The functional behaviour for certain settings is different
         depending on whether local forwarding is enabled or not.
 
 accept_ra - BOOLEAN
         Accept Router Advertisements; autoconfigure using them.
-        
+
         Functional default: enabled if local forwarding is disabled.
                             disabled if local forwarding is enabled.
 
@@ -926,7 +938,7 @@ accept_source_route - INTEGER
         Default: 0
 
 autoconf - BOOLEAN
-        Autoconfigure addresses using Prefix Information in Router 
+        Autoconfigure addresses using Prefix Information in Router
         Advertisements.
 
         Functional default: enabled if accept_ra_pinfo is enabled.
@@ -935,11 +947,11 @@ autoconf - BOOLEAN
 dad_transmits - INTEGER
         The amount of Duplicate Address Detection probes to send.
         Default: 1
-        
+
 forwarding - BOOLEAN
-        Configure interface-specific Host/Router behaviour.  
+        Configure interface-specific Host/Router behaviour.
 
-        Note: It is recommended to have the same setting on all 
+        Note: It is recommended to have the same setting on all
         interfaces; mixed router/host scenarios are rather uncommon.
 
         FALSE:
@@ -948,13 +960,13 @@ forwarding - BOOLEAN
 
         1. IsRouter flag is not set in Neighbour Advertisements.
         2. Router Solicitations are being sent when necessary.
-        3. If accept_ra is TRUE (default), accept Router 
+        3. If accept_ra is TRUE (default), accept Router
            Advertisements (and do autoconfiguration).
         4. If accept_redirects is TRUE (default), accept Redirects.
 
         TRUE:
 
-        If local forwarding is enabled, Router behaviour is assumed. 
+        If local forwarding is enabled, Router behaviour is assumed.
         This means exactly the reverse from the above:
 
         1. IsRouter flag is set in Neighbour Advertisements.
@@ -989,7 +1001,7 @@ router_solicitation_interval - INTEGER
         Default: 4
 
 router_solicitations - INTEGER
-        Number of Router Solicitations to send until assuming no 
+        Number of Router Solicitations to send until assuming no
         routers are present.
         Default: 3
 
@@ -1013,11 +1025,11 @@ temp_prefered_lft - INTEGER
 
 max_desync_factor - INTEGER
         Maximum value for DESYNC_FACTOR, which is a random value
-        that ensures that clients don't synchronize with each 
+        that ensures that clients don't synchronize with each
         other and generate new addresses at exactly the same time.
         value is in seconds.
         Default: 600
-        
+
 regen_max_retry - INTEGER
         Number of attempts before give up attempting to generate
         valid temporary addresses.
@@ -1025,13 +1037,15 @@ regen_max_retry - INTEGER
 
 max_addresses - INTEGER
         Number of maximum addresses per interface.  0 disables limitation.
-        It is recommended not set too large value (or 0) because it would 
-        be too easy way to crash kernel to allow to create too much of 
+        It is recommended not set too large value (or 0) because it would
+        be too easy way to crash kernel to allow to create too much of
         autoconfigured addresses.
         Default: 16
 
 disable_ipv6 - BOOLEAN
-        Disable IPv6 operation.
+        Disable IPv6 operation.  If accept_dad is set to 2, this value
+        will be dynamically set to TRUE if DAD fails for the link-local
+        address.
         Default: FALSE (enable IPv6 operation)
 
 accept_dad - INTEGER