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path: root/net/ipv4/xfrm4_mode_tunnel.c
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2017-04-14xfrm: Add encapsulation header offsets while SKB is not encryptedIlan Tayari
Both esp4 and esp6 used to assume that the SKB payload is encrypted and therefore the inner_network and inner_transport offsets are not relevant. When doing crypto offload in the NIC, this is no longer the case and the NIC driver needs these offsets so it can do TX TCP checksum offloading. This patch sets the inner_network and inner_transport members of the SKB, as well as encapsulation, to reflect the actual positions of these headers, and removes them only once encryption is done on the payload. Signed-off-by: Ilan Tayari <ilant@mellanox.com> Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
2017-04-14xfrm: Add mode handlers for IPsec on layer 2Steffen Klassert
This patch adds a gso_segment and xmit callback for the xfrm_mode and implement these functions for tunnel and transport mode. Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
2015-03-25ipv4: hash net ptr into fragmentation bucket selectionHannes Frederic Sowa
As namespaces are sometimes used with overlapping ip address ranges, we should also use the namespace as input to the hash to select the ip fragmentation counter bucket. Cc: Eric Dumazet <edumazet@google.com> Cc: Flavio Leitner <fbl@redhat.com> Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-06-02inetpeer: get rid of ip_id_countEric Dumazet
Ideally, we would need to generate IP ID using a per destination IP generator. linux kernels used inet_peer cache for this purpose, but this had a huge cost on servers disabling MTU discovery. 1) each inet_peer struct consumes 192 bytes 2) inetpeer cache uses a binary tree of inet_peer structs, with a nominal size of ~66000 elements under load. 3) lookups in this tree are hitting a lot of cache lines, as tree depth is about 20. 4) If server deals with many tcp flows, we have a high probability of not finding the inet_peer, allocating a fresh one, inserting it in the tree with same initial ip_id_count, (cf secure_ip_id()) 5) We garbage collect inet_peer aggressively. IP ID generation do not have to be 'perfect' Goal is trying to avoid duplicates in a short period of time, so that reassembly units have a chance to complete reassembly of fragments belonging to one message before receiving other fragments with a recycled ID. We simply use an array of generators, and a Jenkin hash using the dst IP as a key. ipv6_select_ident() is put back into net/ipv6/ip6_output.c where it belongs (it is only used from this file) secure_ip_id() and secure_ipv6_id() no longer are needed. Rename ip_select_ident_more() to ip_select_ident_segs() to avoid unnecessary decrement/increment of the number of segments. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-02-25xfrm4: Remove xfrm_tunnel_notifierSteffen Klassert
This was used from vti and is replaced by the IPsec protocol multiplexer hooks. It is now unused, so remove it. Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
2013-09-30Merge branch 'master' of ↵David S. Miller
git://git.kernel.org/pub/scm/linux/kernel/git/klassert/ipsec-next Conflicts: include/net/xfrm.h Simple conflict between Joe Perches "extern" removal for function declarations in header files and the changes in Steffen's tree. Steffen Klassert says: ==================== Two patches that are left from the last development cycle. Manual merging of include/net/xfrm.h is needed. The conflict can be solved as it is currently done in linux-next. 1) We announce the creation of temporary acquire state via an asyc event, so the deletion should be annunced too. From Nicolas Dichtel. 2) The VTI tunnels do not real tunning, they just provide a routable IPsec tunnel interface. So introduce and use xfrm_tunnel_notifier instead of xfrm_tunnel for xfrm tunnel mode callback. From Fan Du. ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
2013-09-19ip: generate unique IP identificator if local fragmentation is allowedAnsis Atteka
If local fragmentation is allowed, then ip_select_ident() and ip_select_ident_more() need to generate unique IDs to ensure correct defragmentation on the peer. For example, if IPsec (tunnel mode) has to encrypt large skbs that have local_df bit set, then all IP fragments that belonged to different ESP datagrams would have used the same identificator. If one of these IP fragments would get lost or reordered, then peer could possibly stitch together wrong IP fragments that did not belong to the same datagram. This would lead to a packet loss or data corruption. Signed-off-by: Ansis Atteka <aatteka@nicira.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-08-28{ipv4,xfrm}: Introduce xfrm_tunnel_notifier for xfrm tunnel mode callbackFan Du
Some thoughts on IPv4 VTI implementation: The connection between VTI receiving part and xfrm tunnel mode input process is hardly a "xfrm_tunnel", xfrm_tunnel is used in places where, e.g ipip/sit and xfrm4_tunnel, acts like a true "tunnel" device. In addition, IMHO, VTI doesn't need vti_err to do something meaningful, as all VTI needs is just a notifier to be called whenever xfrm_input ingress a packet to update statistics. A IPsec protected packet is first handled by protocol handlers, e.g AH/ESP, to check packet authentication or encryption rightness. PMTU update is taken care of in this stage by protocol error handler. Then the packet is rearranged properly depending on whether it's transport mode or tunnel mode packed by mode "input" handler. The VTI handler code takes effects in this stage in tunnel mode only. So it neither need propagate PMTU, as it has already been done if necessary, nor the VTI handler is qualified as a xfrm_tunnel. So this patch introduces xfrm_tunnel_notifier and meanwhile wipe out vti_err code. Signed-off-by: Fan Du <fan.du@windriver.com> Cc: Steffen Klassert <steffen.klassert@secunet.com> Cc: David S. Miller <davem@davemloft.net> Reviewed-by: Saurabh Mohan <saurabh.mohan@vyatta.com> Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
2013-03-06xfrm: allow to avoid copying DSCP during encapsulationNicolas Dichtel
By default, DSCP is copying during encapsulation. Copying the DSCP in IPsec tunneling may be a bit dangerous because packets with different DSCP may get reordered relative to each other in the network and then dropped by the remote IPsec GW if the reordering becomes too big compared to the replay window. It is possible to avoid this copy with netfilter rules, but it's very convenient to be able to configure it for each SA directly. This patch adds a toogle for this purpose. By default, it's not set to maintain backward compatibility. Field flags in struct xfrm_usersa_info is full, hence I add a new attribute. Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com> Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
2013-02-18ip: fix warning in xfrm4_mode_tunnel_inputstephen hemminger
Same problem as IPv6 Signed-off-by: Stephen Hemminger <stephen@networkplumber.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-02-15net: Add skb_unclone() helper function.Pravin B Shelar
This function will be used in next GRE_GSO patch. This patch does not change any functionality. Signed-off-by: Pravin B Shelar <pshelar@nicira.com> Acked-by: Eric Dumazet <edumazet@google.com>
2012-07-18net/ipv4: VTI support rx-path hook in xfrm4_mode_tunnel.Saurabh
Incorporated David and Steffen's comments. Add hook for rx-path xfmr4_mode_tunnel for VTI tunnel module. Signed-off-by: Saurabh Mohan <saurabh.mohan@vyatta.com> Reviewed-by: Stephen Hemminger <shemminger@vyatta.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-02-23ipsec: be careful of non existing mac headersEric Dumazet
Niccolo Belli reported ipsec crashes in case we handle a frame without mac header (atm in his case) Before copying mac header, better make sure it is present. Bugzilla reference: https://bugzilla.kernel.org/show_bug.cgi?id=42809 Reported-by: Niccolò Belli <darkbasic@linuxsystems.it> Tested-by: Niccolò Belli <darkbasic@linuxsystems.it> Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-12-12ipv4: Don't pre-seed hoplimit metric.David S. Miller
Always go through a new ip4_dst_hoplimit() helper, just like ipv6. This allowed several simplifications: 1) The interim dst_metric_hoplimit() can go as it's no longer userd. 2) The sysctl_ip_default_ttl entry no longer needs to use ipv4_doint_and_flush, since the sysctl is not cached in routing cache metrics any longer. 3) ipv4_doint_and_flush no longer needs to be exported and therefore can be marked static. When ipv4_doint_and_flush_strategy was removed some time ago, the external declaration in ip.h was mistakenly left around so kill that off too. We have to move the sysctl_ip_default_ttl declaration into ipv4's route cache definition header net/route.h, because currently net/ip.h (where the declaration lives now) has a back dependency on net/route.h Signed-off-by: David S. Miller <davem@davemloft.net>
2010-12-12net: Abstract RTAX_HOPLIMIT metric accesses behind helper.David S. Miller
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-03-30include cleanup: Update gfp.h and slab.h includes to prepare for breaking ↵Tejun Heo
implicit slab.h inclusion from percpu.h percpu.h is included by sched.h and module.h and thus ends up being included when building most .c files. percpu.h includes slab.h which in turn includes gfp.h making everything defined by the two files universally available and complicating inclusion dependencies. percpu.h -> slab.h dependency is about to be removed. Prepare for this change by updating users of gfp and slab facilities include those headers directly instead of assuming availability. As this conversion needs to touch large number of source files, the following script is used as the basis of conversion. http://userweb.kernel.org/~tj/misc/slabh-sweep.py The script does the followings. * Scan files for gfp and slab usages and update includes such that only the necessary includes are there. ie. if only gfp is used, gfp.h, if slab is used, slab.h. * When the script inserts a new include, it looks at the include blocks and try to put the new include such that its order conforms to its surrounding. It's put in the include block which contains core kernel includes, in the same order that the rest are ordered - alphabetical, Christmas tree, rev-Xmas-tree or at the end if there doesn't seem to be any matching order. * If the script can't find a place to put a new include (mostly because the file doesn't have fitting include block), it prints out an error message indicating which .h file needs to be added to the file. The conversion was done in the following steps. 1. The initial automatic conversion of all .c files updated slightly over 4000 files, deleting around 700 includes and adding ~480 gfp.h and ~3000 slab.h inclusions. The script emitted errors for ~400 files. 2. Each error was manually checked. Some didn't need the inclusion, some needed manual addition while adding it to implementation .h or embedding .c file was more appropriate for others. This step added inclusions to around 150 files. 3. The script was run again and the output was compared to the edits from #2 to make sure no file was left behind. 4. Several build tests were done and a couple of problems were fixed. e.g. lib/decompress_*.c used malloc/free() wrappers around slab APIs requiring slab.h to be added manually. 5. The script was run on all .h files but without automatically editing them as sprinkling gfp.h and slab.h inclusions around .h files could easily lead to inclusion dependency hell. Most gfp.h inclusion directives were ignored as stuff from gfp.h was usually wildly available and often used in preprocessor macros. Each slab.h inclusion directive was examined and added manually as necessary. 6. percpu.h was updated not to include slab.h. 7. Build test were done on the following configurations and failures were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my distributed build env didn't work with gcov compiles) and a few more options had to be turned off depending on archs to make things build (like ipr on powerpc/64 which failed due to missing writeq). * x86 and x86_64 UP and SMP allmodconfig and a custom test config. * powerpc and powerpc64 SMP allmodconfig * sparc and sparc64 SMP allmodconfig * ia64 SMP allmodconfig * s390 SMP allmodconfig * alpha SMP allmodconfig * um on x86_64 SMP allmodconfig 8. percpu.h modifications were reverted so that it could be applied as a separate patch and serve as bisection point. Given the fact that I had only a couple of failures from tests on step 6, I'm fairly confident about the coverage of this conversion patch. If there is a breakage, it's likely to be something in one of the arch headers which should be easily discoverable easily on most builds of the specific arch. Signed-off-by: Tejun Heo <tj@kernel.org> Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2009-06-03net: skb->dst accessorsEric Dumazet
Define three accessors to get/set dst attached to a skb struct dst_entry *skb_dst(const struct sk_buff *skb) void skb_dst_set(struct sk_buff *skb, struct dst_entry *dst) void skb_dst_drop(struct sk_buff *skb) This one should replace occurrences of : dst_release(skb->dst) skb->dst = NULL; Delete skb->dst field Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-06-17xfrm: fix fragmentation for ipv4 xfrm tunnelSteffen Klassert
When generating the ip header for the transformed packet we just copy the frag_off field of the ip header from the original packet to the ip header of the new generated packet. If we receive a packet as a chain of fragments, all but the last of the new generated packets have the IP_MF flag set. We have to mask the frag_off field to only keep the IP_DF flag from the original packet. This got lost with git commit 36cf9acf93e8561d9faec24849e57688a81eb9c5 ("[IPSEC]: Separate inner/outer mode processing on output") Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com> Acked-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-03-24[IPSEC]: Fix inter address family IPsec tunnel handling.Kazunori MIYAZAWA
Signed-off-by: Kazunori MIYAZAWA <kazunori@miyazawa.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-01-28[IPSEC]: Rename tunnel-mode functions to avoid collisions with tunnelsHerbert Xu
It appears that I've managed to create two different functions both called xfrm6_tunnel_output. This is because we have the plain tunnel encapsulation named xfrmX_tunnel as well as the tunnel-mode encapsulation which lives in the files xfrmX_mode_tunnel.c. This patch renames functions from the latter to use the xfrmX_mode_tunnel prefix to avoid name-space conflicts. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-01-28[IPSEC]: Separate inner/outer mode processing on inputHerbert Xu
With inter-family transforms the inner mode differs from the outer mode. Attempting to handle both sides from the same function means that it needs to handle both IPv4 and IPv6 which creates duplication and confusion. This patch separates the two parts on the input path so that each function deals with one family only. In particular, the functions xfrm4_extract_inut/xfrm6_extract_inut moves the pertinent fields from the IPv4/IPv6 IP headers into a neutral format stored in skb->cb. This is then used by the inner mode input functions to modify the inner IP header. In this way the input function no longer has to know about the outer address family. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-01-28[IPSEC]: Separate inner/outer mode processing on outputHerbert Xu
With inter-family transforms the inner mode differs from the outer mode. Attempting to handle both sides from the same function means that it needs to handle both IPv4 and IPv6 which creates duplication and confusion. This patch separates the two parts on the output path so that each function deals with one family only. In particular, the functions xfrm4_extract_output/xfrm6_extract_output moves the pertinent fields from the IPv4/IPv6 IP headers into a neutral format stored in skb->cb. This is then used by the outer mode output functions to write the outer IP header. In this way the output function no longer has to know about the inner address family. Since the extract functions are only called by tunnel modes (the only modes that can support inter-family transforms), I've also moved the xfrm*_tunnel_check_size calls into them. This allows the correct ICMP message to be sent as opposed to now where you might call icmp_send with an IPv6 packet and vice versa. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-01-28[INET]: Give outer DSCP directly to ip*_copy_dscpHerbert Xu
This patch changes the prototype of ipv4_copy_dscp and ipv6_copy_dscp so that they directly take the outer DSCP rather than the outer IP header. This will help us to unify the code for inter-family tunnels. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-10-17[IPSEC]: Add missing BEET checksHerbert Xu
Currently BEET mode does not reinject the packet back into the stack like tunnel mode does. Since BEET should behave just like tunnel mode this is incorrect. This patch fixes this by introducing a flags field to xfrm_mode that tells the IPsec code whether it should terminate and reinject the packet back into the stack. It then sets the flag for BEET and tunnel mode. I've also added a number of missing BEET checks elsewhere where we check whether a given mode is a tunnel or not. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-10-10[IPSEC]: Move IP length/checksum setting out of transformsHerbert Xu
This patch moves the setting of the IP length and checksum fields out of the transforms and into the xfrmX_output functions. This would help future efforts in merging the transforms themselves. It also adds an optimisation to ipcomp due to the fact that the transport offset is guaranteed to be zero. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-10-10[IPSEC]: Use IPv6 calling convention as the convention for x->mode->outputHerbert Xu
The IPv6 calling convention for x->mode->output is more general and could help an eventual protocol-generic x->type->output implementation. This patch adopts it for IPv4 as well and modifies the IPv4 type output functions accordingly. It also rewrites the IPv6 mac/transport header calculation to be based off the network header where practical. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-10-10[IPSEC]: Set skb->data to payload in x->mode->outputHerbert Xu
This patch changes the calling convention so that on entry from x->mode->output and before entry into x->type->output skb->data will point to the payload instead of the IP header. This is essentially a redistribution of skb_push/skb_pull calls with the aim of minimising them on the common path of tunnel + ESP. It'll also let us use the same calling convention between IPv4 and IPv6 with the next patch. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-05-31[IPSEC]: Fix panic when using inter address familiy IPsec on loopback.Kazunori MIYAZAWA
Signed-off-by: Kazunori MIYAZAWA <kazunori@miyazawa.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-04-25[SK_BUFF]: unions of just one member don't get anything done, kill themArnaldo Carvalho de Melo
Renaming skb->h to skb->transport_header, skb->nh to skb->network_header and skb->mac to skb->mac_header, to match the names of the associated helpers (skb[_[re]set]_{transport,network,mac}_header). Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-04-25[SK_BUFF]: Introduce ipip_hdr(), remove skb->h.ipiphArnaldo Carvalho de Melo
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-04-25[SK_BUFF]: Introduce ipv6_hdr(), remove skb->nh.ipv6hArnaldo Carvalho de Melo
Now the skb->nh union has just one member, .raw, i.e. it is just like the skb->mac union, strange, no? I'm just leaving it like that till the transport layer is done with, when we'll rename skb->mac.raw to skb->mac_header (or ->mac_header_offset?), ditto for ->{h,nh}. Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-04-25[SK_BUFF]: Introduce ip_hdr(), remove skb->nh.iphArnaldo Carvalho de Melo
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-04-25[SK_BUFF]: Use skb_reset_network_header in skb_push casesArnaldo Carvalho de Melo
skb_push updates and returns skb->data, so we can just call skb_reset_network_header after the call to skb_push. Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-04-25[SK_BUFF]: Introduce skb_reset_network_header(skb)Arnaldo Carvalho de Melo
For the common, open coded 'skb->nh.raw = skb->data' operation, so that we can later turn skb->nh.raw into a offset, reducing the size of struct sk_buff in 64bit land while possibly keeping it as a pointer on 32bit. This one touches just the most simple case, next will handle the slightly more "complex" cases. Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-04-25[SK_BUFF]: Introduce skb_mac_header()Arnaldo Carvalho de Melo
For the places where we need a pointer to the mac header, it is still legal to touch skb->mac.raw directly if just adding to, subtracting from or setting it to another layer header. This one also converts some more cases to skb_reset_mac_header() that my regex missed as it had no spaces before nor after '=', ugh. Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-04-25[SK_BUFF] xfrm: Use skb_set_mac_header in the memmove casesArnaldo Carvalho de Melo
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-04-25[IPV4]: cleanupStephen Hemminger
Add whitespace around keywords. Signed-off-by: Stephen Hemminger <shemminger@linux-foundation.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-02-26[XFRM_TUNNEL]: Reload header pointer after pskb_may_pull/pskb_expand_headArnaldo Carvalho de Melo
Please consider applying, this was found on your latest net-2.6 tree while playing around with that ip_hdr() + turn skb->nh/h/mac pointers as offsets on 64 bits idea :-) Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-02-12[XFRM]: Fix IPv4 tunnel mode decapsulation with IPV6=nPatrick McHardy
Add missing break when CONFIG_IPV6=n. Signed-off-by: Patrick McHardy <kaber@trash.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-02-08[IPSEC]: IPv6 over IPv4 IPsec tunnelMiika Komu
This is the patch to support IPv6 over IPv4 IPsec Signed-off-by: Miika Komu <miika@iki.fi> Signed-off-by: Diego Beltrami <Diego.Beltrami@hiit.fi> Signed-off-by: Kazunori Miyazawa <miyazawa@linux-ipv6.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2006-09-22[IPSEC]: output mode to take an xfrm state as input paramJamal Hadi Salim
Expose IPSEC modes output path to take an xfrm state as input param. This makes it consistent with the input mode processing (which already takes the xfrm state as a param). Signed-off-by: Jamal Hadi Salim <hadi@cyberus.ca> Signed-off-by: David S. Miller <davem@davemloft.net>
2006-07-21[IPV4]: Get rid of redundant IPCB->opts initialisationHerbert Xu
Now that we always zero the IPCB->opts in ip_rcv, it is no longer necessary to do so before calling netif_rx for tunneled packets. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2006-06-17[IPSEC] xfrm: Abstract out encapsulation modesHerbert Xu
This patch adds the structure xfrm_mode. It is meant to represent the operations carried out by transport/tunnel modes. By doing this we allow additional encapsulation modes to be added without clogging up the xfrm_input/xfrm_output paths. Candidate modes include 4-to-6 tunnel mode, 6-to-4 tunnel mode, and BEET modes. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>