Fixed the punctuation and some typos.
Improved some sentences with minor changes.

No change of semantics or code.
Reviewed-by: NMatthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: NRandy Dunlap <rdunlap@infradead.org>
Signed-off-by: NDexuan Cui <decui@microsoft.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The SKB_SGO_CB_OFFSET should be SKB_GSO_CB_OFFSET which means the
offset of the GSO in skb cb. This patch fixes the typo.

Fixes: 9207f9d4 ("net: preserve IP control block during GSO segmentation")
Signed-off-by: NCambda Zhu <cambda@linux.alibaba.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

net/netfilter/nft_fwd_netdev.c: In function ‘nft_fwd_netdev_eval’:
    net/netfilter/nft_fwd_netdev.c:32:10: error: ‘struct sk_buff’ has no member named ‘tc_redirected’
      pkt->skb->tc_redirected = 1;
              ^~
    net/netfilter/nft_fwd_netdev.c:33:10: error: ‘struct sk_buff’ has no member named ‘tc_from_ingress’
      pkt->skb->tc_from_ingress = 1;
              ^~

To avoid a direct dependency with tc actions from netfilter, wrap the
redirect bits around CONFIG_NET_REDIRECT and move helpers to
include/linux/skbuff.h. Turn on this toggle from the ifb driver, the
only existing client of these bits in the tree.

This patch adds skb_set_redirected() that sets on the redirected bit
on the skbuff, it specifies if the packet was redirect from ingress
and resets the timestamp (timestamp reset was originally missing in the
netfilter bugfix).

Fixes: bcfabee1 ("netfilter: nft_fwd_netdev: allow to redirect to ifb via ingress")
Reported-by: noreply@ellerman.id.au
Reported-by: NGeert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The only users for such argument are the UDP protocol and the UNIX
socket family. We can safely reclaim the accounted memory directly
from the UDP code and, after the previous patch, we can do scm
stats accounting outside the datagram helpers.

Overall this cleans up a bit some datagram-related helpers, and
avoids an indirect call per packet in the UDP receive path.

v1 -> v2:
 - call scm_stat_del() only when not peeking - Kirill
 - fix build issue with CONFIG_INET_ESPINTCP
Signed-off-by: NPaolo Abeni <pabeni@redhat.com>
Reviewed-by: NKirill Tkhai <ktkhai@virtuozzo.com>
Reviewed-by: NWillem de Bruijn <willemb@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Fix all kernel-doc warnings in <linux/skbuff.h>.
Fixes these warnings:

../include/linux/skbuff.h:890: warning: Function parameter or member 'list' not described in 'sk_buff'
../include/linux/skbuff.h:890: warning: Function parameter or member 'dev_scratch' not described in 'sk_buff'
../include/linux/skbuff.h:890: warning: Function parameter or member 'ip_defrag_offset' not described in 'sk_buff'
../include/linux/skbuff.h:890: warning: Function parameter or member 'skb_mstamp_ns' not described in 'sk_buff'
../include/linux/skbuff.h:890: warning: Function parameter or member '__cloned_offset' not described in 'sk_buff'
../include/linux/skbuff.h:890: warning: Function parameter or member 'head_frag' not described in 'sk_buff'
../include/linux/skbuff.h:890: warning: Function parameter or member '__pkt_type_offset' not described in 'sk_buff'
../include/linux/skbuff.h:890: warning: Function parameter or member 'encapsulation' not described in 'sk_buff'
../include/linux/skbuff.h:890: warning: Function parameter or member 'encap_hdr_csum' not described in 'sk_buff'
../include/linux/skbuff.h:890: warning: Function parameter or member 'csum_valid' not described in 'sk_buff'
../include/linux/skbuff.h:890: warning: Function parameter or member '__pkt_vlan_present_offset' not described in 'sk_buff'
../include/linux/skbuff.h:890: warning: Function parameter or member 'vlan_present' not described in 'sk_buff'
../include/linux/skbuff.h:890: warning: Function parameter or member 'csum_complete_sw' not described in 'sk_buff'
../include/linux/skbuff.h:890: warning: Function parameter or member 'csum_level' not described in 'sk_buff'
../include/linux/skbuff.h:890: warning: Function parameter or member 'inner_protocol_type' not described in 'sk_buff'
../include/linux/skbuff.h:890: warning: Function parameter or member 'remcsum_offload' not described in 'sk_buff'
../include/linux/skbuff.h:890: warning: Function parameter or member 'sender_cpu' not described in 'sk_buff'
../include/linux/skbuff.h:890: warning: Function parameter or member 'reserved_tailroom' not described in 'sk_buff'
../include/linux/skbuff.h:890: warning: Function parameter or member 'inner_ipproto' not described in 'sk_buff'
Signed-off-by: NRandy Dunlap <rdunlap@infradead.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

sk_buff.qlen can be accessed concurrently as noticed by KCSAN,

 BUG: KCSAN: data-race in __skb_try_recv_from_queue / unix_dgram_sendmsg

 read to 0xffff8a1b1d8a81c0 of 4 bytes by task 5371 on cpu 96:
  unix_dgram_sendmsg+0x9a9/0xb70 include/linux/skbuff.h:1821
				 net/unix/af_unix.c:1761
  ____sys_sendmsg+0x33e/0x370
  ___sys_sendmsg+0xa6/0xf0
  __sys_sendmsg+0x69/0xf0
  __x64_sys_sendmsg+0x51/0x70
  do_syscall_64+0x91/0xb47
  entry_SYSCALL_64_after_hwframe+0x49/0xbe

 write to 0xffff8a1b1d8a81c0 of 4 bytes by task 1 on cpu 99:
  __skb_try_recv_from_queue+0x327/0x410 include/linux/skbuff.h:2029
  __skb_try_recv_datagram+0xbe/0x220
  unix_dgram_recvmsg+0xee/0x850
  ____sys_recvmsg+0x1fb/0x210
  ___sys_recvmsg+0xa2/0xf0
  __sys_recvmsg+0x66/0xf0
  __x64_sys_recvmsg+0x51/0x70
  do_syscall_64+0x91/0xb47
  entry_SYSCALL_64_after_hwframe+0x49/0xbe

Since only the read is operating as lockless, it could introduce a logic
bug in unix_recvq_full() due to the load tearing. Fix it by adding
a lockless variant of skb_queue_len() and unix_recvq_full() where
READ_ONCE() is on the read while WRITE_ONCE() is on the write similar to
the commit d7d16a89 ("net: add skb_queue_empty_lockless()").
Signed-off-by: NQian Cai <cai@lca.pw>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch adds the core functions to chain/unchain
GSO skbs at the frag_list pointer. This also adds
a new GSO type SKB_GSO_FRAGLIST and a is_flist
flag to napi_gro_cb which indicates that this
flow will be GROed by fraglist chaining.
Signed-off-by: NSteffen Klassert <steffen.klassert@secunet.com>
Reviewed-by: NWillem de Bruijn <willemb@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This adds new Fraglist GRO/GSO feature flags. They will be used
to configure fraglist GRO/GSO what will be implemented with some
followup paches.
Signed-off-by: NSteffen Klassert <steffen.klassert@secunet.com>
Reviewed-by: NWillem de Bruijn <willemb@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This worked before, because we made all callers name their next pointer
"next". But in trying to be more "drop-in" ready, the silliness here is
revealed. This commit fixes the problem by making the macro argument and
the member use different names.
Signed-off-by: NJason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Currently we can allocate the extension only after the skb,
this change allows the user to do the opposite, will simplify
allocation failure handling from MPTCP.
Signed-off-by: NPaolo Abeni <pabeni@redhat.com>
Signed-off-by: NMat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Add enum value for MPTCP and update config dependencies

v5 -> v6:
 - fixed '__unused' field size
Co-developed-by: NMatthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: NMatthieu Baerts <matthieu.baerts@tessares.net>
Co-developed-by: NPaolo Abeni <pabeni@redhat.com>
Signed-off-by: NPaolo Abeni <pabeni@redhat.com>
Signed-off-by: NMat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

As part of the continual effort to remove direct usage of skb->next and
skb->prev, this patch adds a helper for iterating through the
singly-linked variant of skb lists, which are used for lists of GSO
packet. The name "skb_list_..." has been chosen to match the existing
function, "kfree_skb_list, which also operates on these singly-linked
lists, and the "..._walk_safe" part is the same idiom as elsewhere in
the kernel.

This patch removes the helper from wireguard and puts it into
linux/skbuff.h, while making it a bit more robust for general usage. In
particular, parenthesis are added around the macro argument usage, and it
now accounts for trying to iterate through an already-null skb pointer,
which will simply run the iteration zero times. This latter enhancement
means it can be used to replace both do { ... } while and while (...)
open-coded idioms.

This should take care of these three possible usages, which match all
current methods of iterations.

skb_list_walk_safe(segs, skb, next) { ... }
skb_list_walk_safe(skb, skb, next) { ... }
skb_list_walk_safe(segs, skb, segs) { ... }

Gcc appears to generate efficient code for each of these.
Signed-off-by: NJason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This will be used by ESP over TCP to handle the queue of IKE messages.
Signed-off-by: NSabrina Dubroca <sd@queasysnail.net>
Acked-by: NDavid S. Miller <davem@davemloft.net>
Signed-off-by: NSteffen Klassert <steffen.klassert@secunet.com>

The skb_mpls_push was not updating ethertype of an ethernet packet if
the packet was originally received from a non ARPHRD_ETHER device.

In the below OVS data path flow, since the device corresponding to
port 7 is an l3 device (ARPHRD_NONE) the skb_mpls_push function does
not update the ethertype of the packet even though the previous
push_eth action had added an ethernet header to the packet.

recirc_id(0),in_port(7),eth_type(0x0800),ipv4(tos=0/0xfc,ttl=64,frag=no),
actions:push_eth(src=00:00:00:00:00:00,dst=00:00:00:00:00:00),
push_mpls(label=13,tc=0,ttl=64,bos=1,eth_type=0x8847),4

Fixes: 8822e270 ("net: core: move push MPLS functionality from OvS to core helper")
Signed-off-by: NMartin Varghese <martin.varghese@nokia.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The skb_mpls_pop was not updating ethertype of an ethernet packet if the
packet was originally received from a non ARPHRD_ETHER device.

In the below OVS data path flow, since the device corresponding to port 7
is an l3 device (ARPHRD_NONE) the skb_mpls_pop function does not update
the ethertype of the packet even though the previous push_eth action had
added an ethernet header to the packet.

recirc_id(0),in_port(7),eth_type(0x8847),
mpls(label=12/0xfffff,tc=0/0,ttl=0/0x0,bos=1/1),
actions:push_eth(src=00:00:00:00:00:00,dst=00:00:00:00:00:00),
pop_mpls(eth_type=0x800),4

Fixes: ed246cee ("net: core: move pop MPLS functionality from OvS to core helper")
Signed-off-by: NMartin Varghese <martin.varghese@nokia.com>
Acked-by: NPravin B Shelar <pshelar@ovn.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Once udp stack has set the UDP_SKB_IS_STATELESS flag, later skb free
assumes all skb head state has been dropped already.

This will leak the extension memory in case the skb has extensions other
than the ipsec secpath, e.g. bridge nf data.

To fix this, set the UDP_SKB_IS_STATELESS flag only if we don't have
extensions or if the extension space can be free'd.

Fixes: 895b5c9f ("netfilter: drop bridge nf reset from nf_reset")
Cc: Paolo Abeni <pabeni@redhat.com>
Reported-by: NByron Stanoszek <gandalf@winds.org>
Signed-off-by: NFlorian Westphal <fw@strlen.de>
Acked-by: NPaolo Abeni <pabeni@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The 'timespec' type definition and helpers like ktime_to_timespec()
or timespec64_to_timespec() should no longer be used in the kernel so
we can remove them and avoid introducing y2038 issues in new code.

Change the socket code that needs to pass a timespec to user space for
backward compatibility to use __kernel_old_timespec instead.  This type
has the same layout but with a clearer defined name.

Slightly reformat tcp_recv_timestamp() for consistency after the removal
of timespec64_to_timespec().
Acked-by: NDeepa Dinamani <deepa.kernel@gmail.com>
Signed-off-by: NArnd Bergmann <arnd@arndb.de>

skb_peek_tail() can be used without protection of a lock,
as spotted by KCSAN [1]

In order to avoid load-stearing, add a READ_ONCE()

Note that the corresponding WRITE_ONCE() are already there.

[1]
BUG: KCSAN: data-race in sk_wait_data / skb_queue_tail

read to 0xffff8880b36a4118 of 8 bytes by task 20426 on cpu 1:
 skb_peek_tail include/linux/skbuff.h:1784 [inline]
 sk_wait_data+0x15b/0x250 net/core/sock.c:2477
 kcm_wait_data+0x112/0x1f0 net/kcm/kcmsock.c:1103
 kcm_recvmsg+0xac/0x320 net/kcm/kcmsock.c:1130
 sock_recvmsg_nosec net/socket.c:871 [inline]
 sock_recvmsg net/socket.c:889 [inline]
 sock_recvmsg+0x92/0xb0 net/socket.c:885
 ___sys_recvmsg+0x1a0/0x3e0 net/socket.c:2480
 do_recvmmsg+0x19a/0x5c0 net/socket.c:2601
 __sys_recvmmsg+0x1ef/0x200 net/socket.c:2680
 __do_sys_recvmmsg net/socket.c:2703 [inline]
 __se_sys_recvmmsg net/socket.c:2696 [inline]
 __x64_sys_recvmmsg+0x89/0xb0 net/socket.c:2696
 do_syscall_64+0xcc/0x370 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

write to 0xffff8880b36a4118 of 8 bytes by task 451 on cpu 0:
 __skb_insert include/linux/skbuff.h:1852 [inline]
 __skb_queue_before include/linux/skbuff.h:1958 [inline]
 __skb_queue_tail include/linux/skbuff.h:1991 [inline]
 skb_queue_tail+0x7e/0xc0 net/core/skbuff.c:3145
 kcm_queue_rcv_skb+0x202/0x310 net/kcm/kcmsock.c:206
 kcm_rcv_strparser+0x74/0x4b0 net/kcm/kcmsock.c:370
 __strp_recv+0x348/0xf50 net/strparser/strparser.c:309
 strp_recv+0x84/0xa0 net/strparser/strparser.c:343
 tcp_read_sock+0x174/0x5c0 net/ipv4/tcp.c:1639
 strp_read_sock+0xd4/0x140 net/strparser/strparser.c:366
 do_strp_work net/strparser/strparser.c:414 [inline]
 strp_work+0x9a/0xe0 net/strparser/strparser.c:423
 process_one_work+0x3d4/0x890 kernel/workqueue.c:2269
 worker_thread+0xa0/0x800 kernel/workqueue.c:2415
 kthread+0x1d4/0x200 drivers/block/aoe/aoecmd.c:1253
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:352

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 451 Comm: kworker/u4:3 Not tainted 5.4.0-rc3+ #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: kstrp strp_work
Signed-off-by: NEric Dumazet <edumazet@google.com>
Reported-by: Nsyzbot <syzkaller@googlegroups.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Some paths call skb_queue_empty() without holding
the queue lock. We must use a barrier in order
to not let the compiler do strange things, and avoid
KCSAN splats.

Adding a barrier in skb_queue_empty() might be overkill,
I prefer adding a new helper to clearly identify
points where the callers might be lockless. This might
help us finding real bugs.

The corresponding WRITE_ONCE() should add zero cost
for current compilers.
Signed-off-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

UDP IPv6 packets auto flowlabels are using a 32bit secret
(static u32 hashrnd in net/core/flow_dissector.c) and
apply jhash() over fields known by the receivers.

Attackers can easily infer the 32bit secret and use this information
to identify a device and/or user, since this 32bit secret is only
set at boot time.

Really, using jhash() to generate cookies sent on the wire
is a serious security concern.

Trying to change the rol32(hash, 16) in ip6_make_flowlabel() would be
a dead end. Trying to periodically change the secret (like in sch_sfq.c)
could change paths taken in the network for long lived flows.

Let's switch to siphash, as we did in commit df453700
("inet: switch IP ID generator to siphash")

Using a cryptographically strong pseudo random function will solve this
privacy issue and more generally remove other weak points in the stack.

Packet schedulers using skb_get_hash_perturb() benefit from this change.

Fixes: b5677416 ("ipv6: Enable auto flow labels by default")
Fixes: 42240901 ("ipv6: Implement different admin modes for automatic flow labels")
Fixes: 67800f9b ("ipv6: Call skb_get_hash_flowi6 to get skb->hash in ip6_make_flowlabel")
Fixes: cb1ce2ef ("ipv6: Implement automatic flow label generation on transmit")
Signed-off-by: NEric Dumazet <edumazet@google.com>
Reported-by: NJonathan Berger <jonathann1@walla.com>
Reported-by: NAmit Klein <aksecurity@gmail.com>
Reported-by: NBenny Pinkas <benny@pinkas.net>
Cc: Tom Herbert <tom@herbertland.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

the following script:

 # tc qdisc add dev eth0 clsact
 # tc filter add dev eth0 egress protocol ip matchall \
 > action mpls push protocol mpls_uc label 0x355aa bos 1

causes corruption of all IP packets transmitted by eth0. On TC egress, we
can't rely on the value of skb->mac_len, because it's 0 and a MPLS 'push'
operation will result in an overwrite of the first 4 octets in the packet
L2 header (e.g. the Destination Address if eth0 is an Ethernet); the same
error pattern is present also in the MPLS 'pop' operation. Fix this error
in act_mpls data plane, computing 'mac_len' as the difference between the
network header and the mac header (when not at TC ingress), and use it in
MPLS 'push'/'pop' core functions.

v2: unbreak 'make htmldocs' because of missing documentation of 'mac_len'
    in skb_mpls_pop(), reported by kbuild test robot

CC: Lorenzo Bianconi <lorenzo@kernel.org>
Fixes: 2a2ea508 ("net: sched: add mpls manipulation actions to TC")
Reviewed-by: NSimon Horman <simon.horman@netronome.com>
Acked-by: NJohn Hurley <john.hurley@netronome.com>
Signed-off-by: NDavide Caratti <dcaratti@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This function de-facto returns a bool, so let's change the return type
accordingly.
Signed-off-by: NHeiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

commit 174e2381
("sk_buff: drop all skb extensions on free and skb scrubbing") made napi
recycle always drop skb extensions.  The additional skb_ext_del() that is
performed via nf_reset on napi skb recycle is not needed anymore.

Most nf_reset() calls in the stack are there so queued skb won't block
'rmmod nf_conntrack' indefinitely.

This removes the skb_ext_del from nf_reset, and renames it to a more
fitting nf_reset_ct().

In a few selected places, add a call to skb_ext_reset to make sure that
no active extensions remain.

I am submitting this for "net", because we're still early in the release
cycle.  The patch applies to net-next too, but I think the rename causes
needless divergence between those trees.
Suggested-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NFlorian Westphal <fw@strlen.de>
Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>

Now that we have a 3rd extension, add a new helper that drops the
extension space and use it when we need to scrub an sk_buff.

At this time, scrubbing clears secpath and bridge netfilter data, but
retains the tc skb extension, after this patch all three get cleared.

NAPI reuse/free assumes we can only have a secpath attached to skb, but
it seems better to clear all extensions there as well.

v2: add unlikely hint (Eric Dumazet)

Fixes: 95a7233c ("net: openvswitch: Set OvS recirc_id from tc chain index")
Signed-off-by: NFlorian Westphal <fw@strlen.de>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Move some `struct nf_conntrack` code from linux/skbuff.h to
linux/nf_conntrack_common.h.  Together with a couple of helpers for
getting and setting skb->_nfct, it allows us to remove
CONFIG_NF_CONNTRACK checks from net/netfilter/nf_conntrack.h.
Signed-off-by: NJeremy Sowden <jeremy@azazel.net>
Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>

Offloaded OvS datapath rules are translated one to one to tc rules,
for example the following simplified OvS rule:

recirc_id(0),in_port(dev1),eth_type(0x0800),ct_state(-trk) actions:ct(),recirc(2)

Will be translated to the following tc rule:

$ tc filter add dev dev1 ingress \
	    prio 1 chain 0 proto ip \
		flower tcp ct_state -trk \
		action ct pipe \
		action goto chain 2

Received packets will first travel though tc, and if they aren't stolen
by it, like in the above rule, they will continue to OvS datapath.
Since we already did some actions (action ct in this case) which might
modify the packets, and updated action stats, we would like to continue
the proccessing with the correct recirc_id in OvS (here recirc_id(2))
where we left off.

To support this, introduce a new skb extension for tc, which
will be used for translating tc chain to ovs recirc_id to
handle these miss cases. Last tc chain index will be set
by tc goto chain action and read by OvS datapath.
Signed-off-by: NPaul Blakey <paulb@mellanox.com>
Signed-off-by: NVlad Buslov <vladbu@mellanox.com>
Acked-by: NJiri Pirko <jiri@mellanox.com>
Acked-by: NPravin B Shelar <pshelar@ovn.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

sk_validate_xmit_skb() and drivers depend on the sk member of
struct sk_buff to identify segments requiring encryption.
Any operation which removes or does not preserve the original TLS
socket such as skb_orphan() or skb_clone() will cause clear text
leaks.

Make the TCP socket underlying an offloaded TLS connection
mark all skbs as decrypted, if TLS TX is in offload mode.
Then in sk_validate_xmit_skb() catch skbs which have no socket
(or a socket with no validation) and decrypted flag set.

Note that CONFIG_SOCK_VALIDATE_XMIT, CONFIG_TLS_DEVICE and
sk->sk_validate_xmit_skb are slightly interchangeable right now,
they all imply TLS offload. The new checks are guarded by
CONFIG_TLS_DEVICE because that's the option guarding the
sk_buff->decrypted member.

Second, smaller issue with orphaning is that it breaks
the guarantee that packets will be delivered to device
queues in-order. All TLS offload drivers depend on that
scheduling property. This means skb_orphan_partial()'s
trick of preserving partial socket references will cause
issues in the drivers. We need a full orphan, and as a
result netem delay/throttling will cause all TLS offload
skbs to be dropped.

Reusing the sk_buff->decrypted flag also protects from
leaking clear text when incoming, decrypted skb is redirected
(e.g. by TC).

See commit 0608c69c ("bpf: sk_msg, sock{map|hash} redirect
through ULP") for justification why the internal flag is safe.
The only location which could leak the flag in is tcp_bpf_sendmsg(),
which is taken care of by clearing the previously unused bit.

v2:
 - remove superfluous decrypted mark copy (Willem);
 - remove the stale doc entry (Boris);
 - rely entirely on EOR marking to prevent coalescing (Boris);
 - use an internal sendpages flag instead of marking the socket
   (Boris).
v3 (Willem):
 - reorganize the can_skb_orphan_partial() condition;
 - fix the flag leak-in through tcp_bpf_sendmsg.
Signed-off-by: NJakub Kicinski <jakub.kicinski@netronome.com>
Acked-by: NWillem de Bruijn <willemb@google.com>
Reviewed-by: NBoris Pismenny <borisp@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Now that page_offset is referenced through accessors, remove
the union, and use bv_offset.
Signed-off-by: NJonathan Lemon <jonathan.lemon@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Add skb_frag_off(), skb_frag_off_add(), skb_frag_off_set(),
and skb_frag_off_copy() accessors for page_offset.
Signed-off-by: NJonathan Lemon <jonathan.lemon@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

C flow dissector supports input flags that tell it to customize parsing
by either stopping early or trying to parse as deep as possible. Pass
those flags to the BPF flow dissector so it can make the same
decisions. In the next commits I'll add support for those flags to
our reference bpf_flow.c

v3:
* Export copy of flow dissector flags instead of moving (Alexei Starovoitov)
Acked-by: NPetar Penkov <ppenkov@google.com>
Acked-by: NWillem de Bruijn <willemb@google.com>
Acked-by: NSong Liu <songliubraving@fb.com>
Cc: Song Liu <songliubraving@fb.com>
Cc: Willem de Bruijn <willemb@google.com>
Cc: Petar Penkov <ppenkov@google.com>
Signed-off-by: NStanislav Fomichev <sdf@google.com>
Signed-off-by: NAlexei Starovoitov <ast@kernel.org>

There are a lot of users of frag->page_offset, so use a union
to avoid converting those users today.
Signed-off-by: NMatthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Improved compatibility with bvec
Signed-off-by: NMatthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

One step closer to turning the skb_frag_t into a bio_vec.
Signed-off-by: NMatthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Match the layout of bio_vec.
Signed-off-by: NMatthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

To increase commonality between block and net, we are going to replace
the skb_frag_t with the bio_vec.  This patch increases the size of
skb_frag_t on 32-bit machines from 8 bytes to 12 bytes.  The size is
unchanged on 64-bit machines.
Signed-off-by: NMatthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

In preparation for unifying the skb_frag and bio_vec, use the fine
accessors which already exist and use skb_frag_t instead of
struct skb_frag_struct.
Signed-off-by: NMatthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Retreives connection tracking zone, mark, label, and state from
a SKB.
Signed-off-by: NPaul Blakey <paulb@mellanox.com>
Signed-off-by: NMarcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Acked-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Currently, TC offers the ability to match on the MPLS fields of a packet
through the use of the flow_dissector_key_mpls struct. However, as yet, TC
actions do not allow the modification or manipulation of such fields.

Add a new module that registers TC action ops to allow manipulation of
MPLS. This includes the ability to push and pop headers as well as modify
the contents of new or existing headers. A further action to decrement the
TTL field of an MPLS header is also provided with a new helper added to
support this.

Examples of the usage of the new action with flower rules to push and pop
MPLS labels are:

tc filter add dev eth0 protocol ip parent ffff: flower \
    action mpls push protocol mpls_uc label 123  \
    action mirred egress redirect dev eth1

tc filter add dev eth0 protocol mpls_uc parent ffff: flower \
    action mpls pop protocol ipv4  \
    action mirred egress redirect dev eth1
Signed-off-by: NJohn Hurley <john.hurley@netronome.com>
Reviewed-by: NJakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: NSimon Horman <simon.horman@netronome.com>
Reviewed-by: NWillem de Bruijn <willemb@google.com>
Acked-by: NCong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Open vSwitch allows the updating of an existing MPLS header on a packet.
In preparation for supporting similar functionality in TC, move this to a
common skb helper function.
Signed-off-by: NJohn Hurley <john.hurley@netronome.com>
Reviewed-by: NJakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: NSimon Horman <simon.horman@netronome.com>
Reviewed-by: NWillem de Bruijn <willemb@google.com>
Acked-by: NCong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Open vSwitch provides code to pop an MPLS header to a packet. In
preparation for supporting this in TC, move the pop code to an skb helper
that can be reused.

Remove the, now unused, update_ethertype static function from OvS.
Signed-off-by: NJohn Hurley <john.hurley@netronome.com>
Reviewed-by: NJakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: NSimon Horman <simon.horman@netronome.com>
Reviewed-by: NWillem de Bruijn <willemb@google.com>
Acked-by: NCong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>