This patch adds the End.BPF action to the LWT seg6local infrastructure.
This action works like any other seg6local End action, meaning that an IPv6
header with SRH is needed, whose DA has to be equal to the SID of the
action. It will also advance the SRH to the next segment, the BPF program
does not have to take care of this.
Since the BPF program may not be a source of instability in the kernel, it
is important to ensure that the integrity of the packet is maintained
before yielding it back to the IPv6 layer. The hook hence keeps track if
the SRH has been altered through the helpers, and re-validates its
content if needed with seg6_validate_srh. The state kept for validation is
stored in a per-CPU buffer. The BPF program is not allowed to directly
write into the packet, and only some fields of the SRH can be altered
through the helper bpf_lwt_seg6_store_bytes.
Performances profiling has shown that the SRH re-validation does not induce
a significant overhead. If the altered SRH is deemed as invalid, the packet
is dropped.
This validation is also done before executing any action through
bpf_lwt_seg6_action, and will not be performed again if the SRH is not
modified after calling the action.
The BPF program may return 3 types of return codes:
- BPF_OK: the End.BPF action will look up the next destination through
seg6_lookup_nexthop.
- BPF_REDIRECT: if an action has been executed through the
bpf_lwt_seg6_action helper, the BPF program should return this
value, as the skb's destination is already set and the default
lookup should not be performed.
- BPF_DROP : the packet will be dropped.
Signed-off-by: Mathieu Xhonneux <m.xhonneux@gmail.com>
Acked-by: David Lebrun <dlebrun@google.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
The BPF seg6local hook should be powerful enough to enable users to
implement most of the use-cases one could think of. After some thinking,
we figured out that the following actions should be possible on a SRv6
packet, requiring 3 specific helpers :
- bpf_lwt_seg6_store_bytes: Modify non-sensitive fields of the SRH
- bpf_lwt_seg6_adjust_srh: Allow to grow or shrink a SRH
(to add/delete TLVs)
- bpf_lwt_seg6_action: Apply some SRv6 network programming actions
(specifically End.X, End.T, End.B6 and
End.B6.Encap)
The specifications of these helpers are provided in the patch (see
include/uapi/linux/bpf.h).
The non-sensitive fields of the SRH are the following : flags, tag and
TLVs. The other fields can not be modified, to maintain the SRH
integrity. Flags, tag and TLVs can easily be modified as their validity
can be checked afterwards via seg6_validate_srh. It is not allowed to
modify the segments directly. If one wants to add segments on the path,
he should stack a new SRH using the End.B6 action via
bpf_lwt_seg6_action.
Growing, shrinking or editing TLVs via the helpers will flag the SRH as
invalid, and it will have to be re-validated before re-entering the IPv6
layer. This flag is stored in a per-CPU buffer, along with the current
header length in bytes.
Storing the SRH len in bytes in the control block is mandatory when using
bpf_lwt_seg6_adjust_srh. The Header Ext. Length field contains the SRH
len rounded to 8 bytes (a padding TLV can be inserted to ensure the 8-bytes
boundary). When adding/deleting TLVs within the BPF program, the SRH may
temporary be in an invalid state where its length cannot be rounded to 8
bytes without remainder, hence the need to store the length in bytes
separately. The caller of the BPF program can then ensure that the SRH's
final length is valid using this value. Again, a final SRH modified by a
BPF program which doesn’t respect the 8-bytes boundary will be discarded
as it will be considered as invalid.
Finally, a fourth helper is provided, bpf_lwt_push_encap, which is
available from the LWT BPF IN hook, but not from the seg6local BPF one.
This helper allows to encapsulate a Segment Routing Header (either with
a new outer IPv6 header, or by inlining it directly in the existing IPv6
header) into a non-SRv6 packet. This helper is required if we want to
offer the possibility to dynamically encapsulate a SRH for non-SRv6 packet,
as the BPF seg6local hook only works on traffic already containing a SRH.
This is the BPF equivalent of the seg6 LWT infrastructure, which achieves
the same purpose but with a static SRH per route.
These helpers require CONFIG_IPV6=y (and not =m).
Signed-off-by: Mathieu Xhonneux <m.xhonneux@gmail.com>
Acked-by: David Lebrun <dlebrun@google.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
The function lookup_nexthop is essential to implement most of the seg6local
actions. As we want to provide a BPF helper allowing to apply some of these
actions on the packet being processed, the helper should be able to call
this function, hence the need to make it public.
Moreover, if one argument is incorrect or if the next hop can not be found,
an error should be returned by the BPF helper so the BPF program can adapt
its processing of the packet (return an error, properly force the drop,
...). This patch hence makes this function return dst->error to indicate a
possible error.
Signed-off-by: Mathieu Xhonneux <m.xhonneux@gmail.com>
Acked-by: David Lebrun <dlebrun@google.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Determine path MTU from a FIB lookup result. Logic is based on
ip6_dst_mtu_forward plus lookup of nexthop exception.
Add ip6_dst_mtu_forward to ipv6_stubs to handle access by core
bpf code.
Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Daniel Borkmann says:
====================
pull-request: bpf-next 2018-05-17
The following pull-request contains BPF updates for your *net-next* tree.
The main changes are:
1) Provide a new BPF helper for doing a FIB and neighbor lookup
in the kernel tables from an XDP or tc BPF program. The helper
provides a fast-path for forwarding packets. The API supports
IPv4, IPv6 and MPLS protocols, but currently IPv4 and IPv6 are
implemented in this initial work, from David (Ahern).
2) Just a tiny diff but huge feature enabled for nfp driver by
extending the BPF offload beyond a pure host processing offload.
Offloaded XDP programs are allowed to set the RX queue index and
thus opening the door for defining a fully programmable RSS/n-tuple
filter replacement. Once BPF decided on a queue already, the device
data-path will skip the conventional RSS processing completely,
from Jakub.
3) The original sockmap implementation was array based similar to
devmap. However unlike devmap where an ifindex has a 1:1 mapping
into the map there are use cases with sockets that need to be
referenced using longer keys. Hence, sockhash map is added reusing
as much of the sockmap code as possible, from John.
4) Introduce BTF ID. The ID is allocatd through an IDR similar as
with BPF maps and progs. It also makes BTF accessible to user
space via BPF_BTF_GET_FD_BY_ID and adds exposure of the BTF data
through BPF_OBJ_GET_INFO_BY_FD, from Martin.
5) Enable BPF stackmap with build_id also in NMI context. Due to the
up_read() of current->mm->mmap_sem build_id cannot be parsed.
This work defers the up_read() via a per-cpu irq_work so that
at least limited support can be enabled, from Song.
6) Various BPF JIT follow-up cleanups and fixups after the LD_ABS/LD_IND
JIT conversion as well as implementation of an optimized 32/64 bit
immediate load in the arm64 JIT that allows to reduce the number of
emitted instructions; in case of tested real-world programs they
were shrinking by three percent, from Daniel.
7) Add ifindex parameter to the libbpf loader in order to enable
BPF offload support. Right now only iproute2 can load offloaded
BPF and this will also enable libbpf for direct integration into
other applications, from David (Beckett).
8) Convert the plain text documentation under Documentation/bpf/ into
RST format since this is the appropriate standard the kernel is
moving to for all documentation. Also add an overview README.rst,
from Jesper.
9) Add __printf verification attribute to the bpf_verifier_vlog()
helper. Though it uses va_list we can still allow gcc to check
the format string, from Mathieu.
10) Fix a bash reference in the BPF selftest's Makefile. The '|& ...'
is a bash 4.0+ feature which is not guaranteed to be available
when calling out to shell, therefore use a more portable variant,
from Joe.
11) Fix a 64 bit division in xdp_umem_reg() by using div_u64()
instead of relying on the gcc built-in, from Björn.
12) Fix a sock hashmap kmalloc warning reported by syzbot when an
overly large key size is used in hashmap then causing overflows
in htab->elem_size. Reject bogus attr->key_size early in the
sock_hash_alloc(), from Yonghong.
13) Ensure in BPF selftests when urandom_read is being linked that
--build-id is always enabled so that test_stacktrace_build_id[_nmi]
won't be failing, from Alexei.
14) Add bitsperlong.h as well as errno.h uapi headers into the tools
header infrastructure which point to one of the arch specific
uapi headers. This was needed in order to fix a build error on
some systems for the BPF selftests, from Sirio.
15) Allow for short options to be used in the xdp_monitor BPF sample
code. And also a bpf.h tools uapi header sync in order to fix a
selftest build failure. Both from Prashant.
16) More formally clarify the meaning of ID in the direct packet access
section of the BPF documentation, from Wang.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
The bpf syscall and selftests conflicts were trivial
overlapping changes.
The r8169 change involved moving the added mdelay from 'net' into a
different function.
A TLS close bug fix overlapped with the splitting of the TLS state
into separate TX and RX parts. I just expanded the tests in the bug
fix from "ctx->conf == X" into "ctx->tx_conf == X && ctx->rx_conf
== X".
Signed-off-by: David S. Miller <davem@davemloft.net>
Currently the truncated bit is set only when 1) the mirrored packet
is larger than mtu and 2) the ipv4 packet tot_len is larger than
the actual skb->len. This patch adds another case for detecting
whether ipv6 packet is truncated or not, by checking the ipv6 header
payload_len and the skb->len.
Reported-by: Xiaoyan Jin <xiaoyanj@vmware.com>
Signed-off-by: William Tu <u9012063@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add stubs to retrieve a handle to an IPv6 FIB table, fib6_get_table,
a stub to do a lookup in a specific table, fib6_table_lookup, and
a stub for a full route lookup.
The stubs are needed for core bpf code to handle the case when the
IPv6 module is not builtin.
Signed-off-by: David Ahern <dsahern@gmail.com>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Similar to IPv4, IPv6 should use the FIB lookup result in the
tracepoint.
Signed-off-by: David Ahern <dsahern@gmail.com>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Add IPv6 equivalent to fib_lookup. Does a fib lookup, including rules,
but returns a FIB entry, fib6_info, rather than a dst based rt6_info.
fib6_lookup is any where from 140% (MULTIPLE_TABLES config disabled)
to 60% faster than any of the dst based lookup methods (without custom
rules) and 25% faster with custom rules (e.g., l3mdev rule).
Since the lookup function has a completely different signature,
fib6_rule_action is split into 2 paths: the existing one is
renamed __fib6_rule_action and a new one for the fib6_info path
is added. fib6_rule_action decides which to call based on the
lookup_ptr. If it is fib6_table_lookup then the new path is taken.
Caller must hold rcu lock as no reference is taken on the returned
fib entry.
Signed-off-by: David Ahern <dsahern@gmail.com>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Move source address lookup from fib6_rule_action to a helper. It will be
used in a later patch by a second variant for fib6_rule_action.
Signed-off-by: David Ahern <dsahern@gmail.com>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
ip6_pol_route is used for ingress and egress FIB lookups. Refactor it
moving the table lookup into a separate fib6_table_lookup that can be
invoked separately and export the new function.
ip6_pol_route now calls fib6_table_lookup and uses the result to generate
a dst based rt6_info.
Signed-off-by: David Ahern <dsahern@gmail.com>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Rename rt6_multipath_select to fib6_multipath_select and export it.
A later patch wants access to it similar to IPv4's fib_select_path.
Signed-off-by: David Ahern <dsahern@gmail.com>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Rename fib6_lookup to fib6_node_lookup to better reflect what it
returns. The fib6_lookup name will be used in a later patch for
an IPv6 equivalent to IPv4's fib_lookup.
Signed-off-by: David Ahern <dsahern@gmail.com>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
This version has some suggestions by Eric Dumazet:
- Use a local variable for the mark in IPv6 instead of ctl_sk to avoid SMP
races.
- Use the more elegant "IP4_REPLY_MARK(net, skb->mark) ?: sk->sk_mark"
statement.
- Factorize code as sk_fullsock() check is not necessary.
Aidan McGurn from Openwave Mobility systems reported the following bug:
"Marked routing is broken on customer deployment. Its effects are large
increase in Uplink retransmissions caused by the client never receiving
the final ACK to their FINACK - this ACK misses the mark and routes out
of the incorrect route."
Currently marks are added to sk_buffs for replies when the "fwmark_reflect"
sysctl is enabled. But not for TW sockets that had sk->sk_mark set via
setsockopt(SO_MARK..).
Fix this in IPv4/v6 by adding tw->tw_mark for TIME_WAIT sockets. Copy the the
original sk->sk_mark in __inet_twsk_hashdance() to the new tw->tw_mark location.
Then progate this so that the skb gets sent with the correct mark. Do the same
for resets. Give the "fwmark_reflect" sysctl precedence over sk->sk_mark so that
netfilter rules are still honored.
Signed-off-by: Jon Maxwell <jmaxwell37@gmail.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Damir reported a breakage of SO_BINDTODEVICE for UDP sockets.
In absence of VRF devices, after commit fb74c27735f0 ("net:
ipv4: add second dif to udp socket lookups") the dif mismatch
isn't fatal anymore for UDP socket lookup with non null
sk_bound_dev_if, breaking SO_BINDTODEVICE semantics.
This changeset addresses the issue making the dif match mandatory
again in the above scenario.
Reported-by: Damir Mansurov <dnman@oktetlabs.ru>
Fixes: fb74c27735f0 ("net: ipv4: add second dif to udp socket lookups")
Fixes: 1801b570dd2a ("net: ipv6: add second dif to udp socket lookups")
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Acked-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
No changes in refcount semantics -- key init is false; replace
static_key_enable with static_branch_enable
static_key_slow_inc|dec with static_branch_inc|dec
static_key_false with static_branch_unlikely
Added a '_key' suffix to udp and udpv6 encap_needed, for better
self documentation.
Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch adds support for a software provided checksum and GSO_PARTIAL
segmentation support. With this we can offload UDP segmentation on devices
that only have partial support for tunnels.
Since we are no longer needing the hardware checksum we can drop the checks
in the segmentation code that were verifying if it was present.
Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Acked-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch is meant to allow us to avoid having to recompute the checksum
from scratch and have it passed as a parameter.
Instead of taking that approach we can take advantage of the fact that the
length that was used to compute the existing checksum is included in the
UDP header.
Finally to avoid the need to invert the result we can just call csum16_add
and csum16_sub directly. By doing this we can avoid a number of
instructions in the loop that is handling segmentation.
Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Acked-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
There is no point in passing MSS as a parameter for for the GSO
segmentation call as it is already available via the shared info for the
skb itself.
Reviewed-by: Eric Dumazet <edumazet@google.com>
Acked-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch removes "experimental" from the help text where depends on
CONFIG_EXPERIMENTAL was already removed.
Signed-off-by: Georg Hofmann <georg@hofmannsweb.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Steffen Klassert says:
====================
pull request (net): ipsec 2018-05-07
1) Always verify length of provided sadb_key to fix a
slab-out-of-bounds read in pfkey_add. From Kevin Easton.
2) Make sure that all states are really deleted
before we check that the state lists are empty.
Otherwise we trigger a warning.
3) Fix MTU handling of the VTI6 interfaces on
interfamily tunnels. From Stefano Brivio.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
Add GRO capability for IPv6 GRE tunnel and ip6erspan tap, via gro_cells
infrastructure.
Performance testing: 55% higher badwidth.
Measuring bandwidth of 1 thread IPv4 TCP traffic over IPv6 GRE tunnel
while GRO on the physical interface is disabled.
CPU: Intel Xeon E312xx (Sandy Bridge)
NIC: Mellanox Technologies MT27700 Family [ConnectX-4]
Before (GRO not working in tunnel) : 2.47 Gbits/sec
After (GRO working in tunnel) : 3.85 Gbits/sec
Signed-off-by: Eran Ben Elisha <eranbe@mellanox.com>
Signed-off-by: Tariq Toukan <tariqt@mellanox.com>
CC: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Fix 'an' into 'and', and use a comma instead of a period.
Signed-off-by: Tariq Toukan <tariqt@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Pablo Neira Ayuso says:
====================
Netfilter/IPVS updates for net-next
The following patchset contains Netfilter/IPVS updates for your net-next
tree, more relevant updates in this batch are:
1) Add Maglev support to IPVS. Moreover, store lastest server weight in
IPVS since this is needed by maglev, patches from from Inju Song.
2) Preparation works to add iptables flowtable support, patches
from Felix Fietkau.
3) Hand over flows back to conntrack slow path in case of TCP RST/FIN
packet is seen via new teardown state, also from Felix.
4) Add support for extended netlink error reporting for nf_tables.
5) Support for larger timeouts that 23 days in nf_tables, patch from
Florian Westphal.
6) Always set an upper limit to dynamic sets, also from Florian.
7) Allow number generator to make map lookups, from Laura Garcia.
8) Use hash_32() instead of opencode hashing in IPVS, from Vicent Bernat.
9) Extend ip6tables SRH match to support previous, next and last SID,
from Ahmed Abdelsalam.
10) Move Passive OS fingerprint nf_osf.c, from Fernando Fernandez.
11) Expose nf_conntrack_max through ctnetlink, from Florent Fourcot.
12) Several housekeeping patches for xt_NFLOG, x_tables and ebtables,
from Taehee Yoo.
13) Unify meta bridge with core nft_meta, then make nft_meta built-in.
Make rt and exthdr built-in too, again from Florian.
14) Missing initialization of tbl->entries in IPVS, from Cong Wang.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
IPv6 Segment Routing Header (SRH) contains a list of SIDs to be crossed
by SR encapsulated packet. Each SID is encoded as an IPv6 prefix.
When a Firewall receives an SR encapsulated packet, it should be able
to identify which node previously processed the packet (previous SID),
which node is going to process the packet next (next SID), and which
node is the last to process the packet (last SID) which represent the
final destination of the packet in case of inline SR mode.
An example use-case of using these features could be SID list that
includes two firewalls. When the second firewall receives a packet,
it can check whether the packet has been processed by the first firewall
or not. Based on that check, it decides to apply all rules, apply just
subset of the rules, or totally skip all rules and forward the packet to
the next SID.
This patch extends SRH match to support matching previous SID, next SID,
and last SID.
Signed-off-by: Ahmed Abdelsalam <amsalam20@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This slipped through the cracks in the followup set to the fib6_info flip.
Rename rt6_next to fib6_next.
Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The function name is wrong in ip6gre_tnl_addr_conflict() comment, which
use ip6_tnl_addr_conflict instead of ip6gre_tnl_addr_conflict.
Signed-off-by: Sun Lianwen <sunlw.fnst@cn.fujitsu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This reverts commit edd7ceb78296 ("ipv6: Allow non-gateway ECMP for
IPv6").
Eric reported a division by zero in rt6_multipath_rebalance() which is
caused by above commit that considers identical local routes to be
siblings. The division by zero happens because a nexthop weight is not
set for local routes.
Revert the commit as it does not fix a bug and has side effects.
To reproduce:
# ip -6 address add 2001:db8::1/64 dev dummy0
# ip -6 address add 2001:db8::1/64 dev dummy1
Fixes: edd7ceb78296 ("ipv6: Allow non-gateway ECMP for IPv6")
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Reported-by: Eric Dumazet <eric.dumazet@gmail.com>
Tested-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
It is valid to have static routes where the nexthop
is an interface not an address such as tunnels.
For IPv4 it was possible to use ECMP on these routes
but not for IPv6.
Signed-off-by: Thomas Winter <Thomas.Winter@alliedtelesis.co.nz>
Cc: David Ahern <dsahern@gmail.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>
Cc: Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org>
Acked-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Syzbot managed to send a udp gso packet without checksum offload into
the gso stack by disabling tx checksum (UDP_NO_CHECK6_TX). This
triggered the skb_warn_bad_offload.
RIP: 0010:skb_warn_bad_offload+0x2bc/0x600 net/core/dev.c:2658
skb_gso_segment include/linux/netdevice.h:4038 [inline]
validate_xmit_skb+0x54d/0xd90 net/core/dev.c:3120
__dev_queue_xmit+0xbf8/0x34c0 net/core/dev.c:3577
dev_queue_xmit+0x17/0x20 net/core/dev.c:3618
UDP_NO_CHECK6_TX sets skb->ip_summed to CHECKSUM_NONE just after the
udp gso integrity checks in udp_(v6_)send_skb. Extend those checks to
catch and fail in this case.
After the integrity checks jump directly to the CHECKSUM_PARTIAL case
to avoid reading the no_check_tx flags again (a TOCTTOU race).
Fixes: bec1f6f69736 ("udp: generate gso with UDP_SEGMENT")
Signed-off-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The comment of vti6_ioctl() is wrong. which use vti6_tnl_ioctl
instead of vti6_ioctl.
Signed-off-by: Sun Lianwen <sunlw.fnst@cn.fujitsu.com>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
The seg6_make_flowlabel() is used by seg6_do_srh_encap() to compute the
flowlabel from a given skb. It relies on skb_get_hash() which eventually
calls __skb_flow_dissect() to extract the flow_keys struct values from
the skb.
In case of IPv4 traffic, calling seg6_make_flowlabel() after skb_push(),
skb_reset_network_header(), and skb_mac_header_rebuild() will results in
flow_keys struct of all key values set to zero.
This patch calls seg6_make_flowlabel() before resetting the headers of skb
to get the right key values.
Extracted Key values are based on the type inner packet as follows:
1) IPv6 traffic: src_IP, dst_IP, L4 proto, and flowlabel of inner packet.
2) IPv4 traffic: src_IP, dst_IP, L4 proto, src_port, and dst_port
3) L2 traffic: depends on what kind of traffic carried into the L2
frame. IPv6 and IPv4 traffic works as discussed 1) and 2)
Here a hex_dump of struct flow_keys for IPv4 and IPv6 traffic
10.100.1.100: 47302 > 30.0.0.2: 5001
00000000: 14 00 02 00 00 00 00 00 08 00 11 00 00 00 00 00
00000010: 00 00 00 00 00 00 00 00 13 89 b8 c6 1e 00 00 02
00000020: 0a 64 01 64
fc00:a1:a > b2::2
00000000: 28 00 03 00 00 00 00 00 86 dd 11 00 99 f9 02 00
00000010: 00 00 00 00 00 00 00 00 00 00 00 00 00 b2 00 00
00000020: 00 00 00 00 00 00 00 00 00 00 00 02 fc 00 00 a1
00000030: 00 00 00 00 00 00 00 00 00 00 00 0a
Signed-off-by: Ahmed Abdelsalam <amsalam20@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Currently the truncated bit is set only when the mirrored packet
is larger than mtu. For certain cases, the packet might already
been truncated before sending to the erspan tunnel. In this case,
the patch detect whether the IP header's total length is larger
than the actual skb->len. If true, this indicated that the
mirrored packet is truncated and set the erspan truncate bit.
I tested the patch using bpf_skb_change_tail helper function to
shrink the packet size and send to erspan tunnel.
Reported-by: Xiaoyan Jin <xiaoyanj@vmware.com>
Signed-off-by: William Tu <u9012063@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
When adding tcp mmap() implementation, I forgot that socket lock
had to be taken before current->mm->mmap_sem. syzbot eventually caught
the bug.
Since we can not lock the socket in tcp mmap() handler we have to
split the operation in two phases.
1) mmap() on a tcp socket simply reserves VMA space, and nothing else.
This operation does not involve any TCP locking.
2) getsockopt(fd, IPPROTO_TCP, TCP_ZEROCOPY_RECEIVE, ...) implements
the transfert of pages from skbs to one VMA.
This operation only uses down_read(¤t->mm->mmap_sem) after
holding TCP lock, thus solving the lockdep issue.
This new implementation was suggested by Andy Lutomirski with great details.
Benefits are :
- Better scalability, in case multiple threads reuse VMAS
(without mmap()/munmap() calls) since mmap_sem wont be write locked.
- Better error recovery.
The previous mmap() model had to provide the expected size of the
mapping. If for some reason one part could not be mapped (partial MSS),
the whole operation had to be aborted.
With the tcp_zerocopy_receive struct, kernel can report how
many bytes were successfuly mapped, and how many bytes should
be read to skip the problematic sequence.
- No more memory allocation to hold an array of page pointers.
16 MB mappings needed 32 KB for this array, potentially using vmalloc() :/
- skbs are freed while mmap_sem has been released
Following patch makes the change in tcp_mmap tool to demonstrate
one possible use of mmap() and setsockopt(... TCP_ZEROCOPY_RECEIVE ...)
Note that memcg might require additional changes.
Fixes: 93ab6cc69162 ("tcp: implement mmap() for zero copy receive")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Suggested-by: Andy Lutomirski <luto@kernel.org>
Cc: linux-mm@kvack.org
Acked-by: Soheil Hassas Yeganeh <soheil@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
A vti6 interface can carry IPv4 as well, so it makes no sense to
enforce a minimum MTU of IPV6_MIN_MTU.
If the user sets an MTU below IPV6_MIN_MTU, IPv6 will be
disabled on the interface, courtesy of addrconf_notify().
Reported-by: Xin Long <lucien.xin@gmail.com>
Fixes: b96f9afee4eb ("ipv4/6: use core net MTU range checking")
Fixes: c6741fbed6dc ("vti6: Properly adjust vti6 MTU from MTU of lower device")
Fixes: 53c81e95df17 ("ip6_vti: adjust vti mtu according to mtu of lower device")
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Allow specifying segment size in the send call.
The new control message performs the same function as socket option
UDP_SEGMENT while avoiding the extra system call.
[ Export udp_cmsg_send for ipv6. -DaveM ]
Signed-off-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
When sending large datagrams that are later segmented, store data in
page frags to avoid copying from linear in skb_segment.
Signed-off-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Support generic segmentation offload for udp datagrams. Callers can
concatenate and send at once the payload of multiple datagrams with
the same destination.
To set segment size, the caller sets socket option UDP_SEGMENT to the
length of each discrete payload. This value must be smaller than or
equal to the relevant MTU.
A follow-up patch adds cmsg UDP_SEGMENT to specify segment size on a
per send call basis.
Total byte length may then exceed MTU. If not an exact multiple of
segment size, the last segment will be shorter.
The implementation adds a gso_size field to the udp socket, ip(v6)
cmsg cookie and inet_cork structure to be able to set the value at
setsockopt or cmsg time and to work with both lockless and corked
paths.
Initial benchmark numbers show UDP GSO about as expensive as TCP GSO.
tcp tso
3197 MB/s 54232 msg/s 54232 calls/s
6,457,754,262 cycles
tcp gso
1765 MB/s 29939 msg/s 29939 calls/s
11,203,021,806 cycles
tcp without tso/gso *
739 MB/s 12548 msg/s 12548 calls/s
11,205,483,630 cycles
udp
876 MB/s 14873 msg/s 624666 calls/s
11,205,777,429 cycles
udp gso
2139 MB/s 36282 msg/s 36282 calls/s
11,204,374,561 cycles
[*] after reverting commit 0a6b2a1dc2a2
("tcp: switch to GSO being always on")
Measured total system cycles ('-a') for one core while pinning both
the network receive path and benchmark process to that core:
perf stat -a -C 12 -e cycles \
./udpgso_bench_tx -C 12 -4 -D "$DST" -l 4
Note the reduction in calls/s with GSO. Bytes per syscall drops
increases from 1470 to 61818.
Signed-off-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Implement generic segmentation offload support for udp datagrams. A
follow-up patch adds support to the protocol stack to generate such
packets.
UDP GSO is not UFO. UFO fragments a single large datagram. GSO splits
a large payload into a number of discrete UDP datagrams.
The implementation adds a GSO type SKB_UDP_GSO_L4 to differentiate it
from UFO (SKB_UDP_GSO).
IPPROTO_UDPLITE is excluded, as that protocol has no gso handler
registered.
[ Export __udp_gso_segment for ipv6. -DaveM ]
Signed-off-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
UDP segmentation offload needs access to inet_cork in the udp layer.
Pass the struct to ip(6)_make_skb instead of allocating it on the
stack in that function itself.
This patch is a noop otherwise.
Signed-off-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
In the quest to remove all stack VLA usage removed from the kernel[1],
just use XFRM_MAX_DEPTH as already done for the "class" array. In one
case, it'll do this loop up to 5, the other caller up to 6.
[1] https://lkml.org/lkml/2018/3/7/621
Co-developed-by: Andreas Christoforou <andreaschristofo@gmail.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Acked-by: Stefano Brivio <sbrivio@redhat.com>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
The addrconf_ifdown() evaluates keep_addr_on_down state twice. There
is no need to do it.
Cc: David Ahern <dsahern@gmail.com>
Signed-off-by: Ivan Vecera <cera@cera.cz>
Signed-off-by: David S. Miller <davem@davemloft.net>
ECMP (equal-cost multipath) hashes are typically computed on the packets'
5-tuple(src IP, dst IP, src port, dst port, L4 proto).
For encapsulated packets, the L4 data is not readily available and ECMP
hashing will often revert to (src IP, dst IP). This will lead to traffic
polarization on a single ECMP path, causing congestion and waste of network
capacity.
In IPv6, the 20-bit flow label field is also used as part of the ECMP hash.
In the lack of L4 data, the hashing will be on (src IP, dst IP, flow
label). Having a non-zero flow label is thus important for proper traffic
load balancing when L4 data is unavailable (i.e., when packets are
encapsulated).
Currently, the seg6_do_srh_encap() function extracts the original packet's
flow label and set it as the outer IPv6 flow label. There are two issues
with this behaviour:
a) There is no guarantee that the inner flow label is set by the source.
b) If the original packet is not IPv6, the flow label will be set to
zero (e.g., IPv4 or L2 encap).
This patch adds a function, named seg6_make_flowlabel(), that computes a
flow label from a given skb. It supports IPv6, IPv4 and L2 payloads, and
leverages the per namespace 'seg6_flowlabel" sysctl value.
The currently support behaviours are as follows:
-1 set flowlabel to zero.
0 copy flowlabel from Inner paceket in case of Inner IPv6
(Set flowlabel to 0 in case IPv4/L2)
1 Compute the flowlabel using seg6_make_flowlabel()
This patch has been tested for IPv6, IPv4, and L2 traffic.
Signed-off-by: Ahmed Abdelsalam <amsalam20@gmail.com>
Acked-by: David Lebrun <dlebrun@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
