Adds support for calling sock_ops BPF program when there is a TCP state
change. Two arguments are used; one for the old state and another for
the new state.

There is a new enum in include/uapi/linux/bpf.h that exports the TCP
states that prepends BPF_ to the current TCP state names. If it is ever
necessary to change the internal TCP state values (other than adding
more to the end), then it will become necessary to convert from the
internal TCP state value to the BPF value before calling the BPF
sock_ops function. There are a set of compile checks added in tcp.c
to detect if the internal and BPF values differ so we can make the
necessary fixes.

New op: BPF_SOCK_OPS_STATE_CB.
Signed-off-by: NLawrence Brakmo <brakmo@fb.com>
Signed-off-by: NAlexei Starovoitov <ast@kernel.org>

Adds support for calling sock_ops BPF program when there is a
retransmission. Three arguments are used; one for the sequence number,
another for the number of segments retransmitted, and the last one for
the return value of tcp_transmit_skb (0 => success).
Does not include syn-ack retransmissions.

New op: BPF_SOCK_OPS_RETRANS_CB.
Signed-off-by: NLawrence Brakmo <brakmo@fb.com>
Signed-off-by: NAlexei Starovoitov <ast@kernel.org>

Adds an optional call to sock_ops BPF program based on whether the
BPF_SOCK_OPS_RTO_CB_FLAG is set in bpf_sock_ops_flags.
The BPF program is passed 2 arguments: icsk_retransmits and whether the
RTO has expired.
Signed-off-by: NLawrence Brakmo <brakmo@fb.com>
Signed-off-by: NAlexei Starovoitov <ast@kernel.org>

Adds support for passing up to 4 arguments to sock_ops bpf functions. It
reusues the reply union, so the bpf_sock_ops structures are not
increased in size.
Signed-off-by: NLawrence Brakmo <brakmo@fb.com>
Signed-off-by: NAlexei Starovoitov <ast@kernel.org>

A persistent connection may send tiny amount of data (e.g. health-check)
for a long period of time. BBR's windowed min RTT filter may only see
RTT samples from delayed ACKs causing BBR to grossly over-estimate
the path delay depending how much the ACK was delayed at the receiver.

This patch skips RTT samples that are likely coming from delayed ACKs. Note
that it is possible the sender never obtains a valid measure to set the
min RTT. In this case BBR will continue to set cwnd to initial window
which seems fine because the connection is thin stream.
Signed-off-by: NYuchung Cheng <ycheng@google.com>
Acked-by: NNeal Cardwell <ncardwell@google.com>
Acked-by: NSoheil Hassas Yeganeh <soheil@google.com>
Acked-by: NPriyaranjan Jha <priyarjha@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch avoids having TCP sender or congestion control
overestimate the min RTT by orders of magnitude. This happens when
all the samples in the windowed filter are one-packet transfer
like small request and health-check like chit-chat, which is farily
common for applications using persistent connections. This patch
tries to conservatively labels and skip RTT samples obtained from
this type of workload.
Signed-off-by: NYuchung Cheng <ycheng@google.com>
Signed-off-by: NSoheil Hassas Yeganeh <soheil@google.com>
Acked-by: NNeal Cardwell <ncardwell@google.com>
Acked-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Several reasons for this:

* Several modules maintain internal version numbers, that they print at
  boot/module load time, that are not exposed to userspace, as a
  primitive mechanism to make revision number control from the earlier
  days of Netfilter.

* IPset shows the protocol version at boot/module load time, instead
  display this via module description, as Jozsef suggested.

* Remove copyright notice at boot/module load time in two spots, the
  Netfilter codebase is a collective development effort, if we would
  have to display copyrights for each contributor at boot/module load
  time for each extensions we have, we would probably fill up logs with
  lots of useless information - from a technical standpoint.

So let's be consistent and remove them all.
Acked-by: NFlorian Westphal <fw@strlen.de>
Acked-by: NJozsef Kadlecsik <kadlec@blackhole.kfki.hu>
Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>

The basic SNMP ALG parse snmp ASN.1 payload
however, since 2012 linux kernel provide ASN.1 decoder library.
If we use ASN.1 decoder in the /lib/asn1_decoder.c, we can remove
about 1000 line of ASN.1 parsing routine.

To use asn1_decoder.c, we should write mib file(nf_nat_snmp_basic.asn1)
then /script/asn1_compiler.c makes *-asn1.c and *-asn1.h file
at the compiletime.(nf_nat_snmp_basic-asn1.c, nf_nat_snmp_basic-asn1.h)
The nf_nat_snmp_basic.asn1 is made by RFC1155, RFC1157, RFC1902, RFC1905,
RFC2578, RFC3416. of course that mib file supports only the basic SNMP ALG.

Previous SNMP ALG mangles only first octet of IPv4 address.
but after this patch, the SNMP ALG mangles whole IPv4 Address.
And SNMPv3 is not supported.

I tested with snmp commands such ans snmpd, snmpwalk, snmptrap.
Signed-off-by: NTaehee Yoo <ap420073@gmail.com>
Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>

Use nf_ct_helper_log to write log message.
Signed-off-by: NTaehee Yoo <ap420073@gmail.com>
Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>

The snmp_translate() receives ctinfo data to get dir value only.
because of caller already has dir value, we just replace ctinfo with dir.
Signed-off-by: NTaehee Yoo <ap420073@gmail.com>
Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>

To see debug message of nf_nat_snmp_basic, we should set debug value
when we insert this module. but it is inconvenient and only using of
the dynamic debugging is enough to debug.

This patch just removes debug code. then in the next patch, debugging code
will be added.
Signed-off-by: NTaehee Yoo <ap420073@gmail.com>
Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>

Remove comments that do not let us know important information.
Signed-off-by: NTaehee Yoo <ap420073@gmail.com>
Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>

/proc has been ignoring struct file_operations::owner field for 10 years.
Specifically, it started with commit 786d7e16
("Fix rmmod/read/write races in /proc entries"). Notice the chunk where
inode->i_fop is initialized with proxy struct file_operations for
regular files:

	-               if (de->proc_fops)
	-                       inode->i_fop = de->proc_fops;
	+               if (de->proc_fops) {
	+                       if (S_ISREG(inode->i_mode))
	+                               inode->i_fop = &proc_reg_file_ops;
	+                       else
	+                               inode->i_fop = de->proc_fops;
	+               }

VFS stopped pinning module at this point.
Signed-off-by: NAlexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

We cannot access the skb->_nfct field when CONFIG_NF_CONNTRACK is
disabled:

net/ipv4/netfilter/nf_defrag_ipv4.c: In function 'ipv4_conntrack_defrag':
net/ipv4/netfilter/nf_defrag_ipv4.c:83:9: error: 'struct sk_buff' has no member named '_nfct'
net/ipv6/netfilter/nf_defrag_ipv6_hooks.c: In function 'ipv6_defrag':
net/ipv6/netfilter/nf_defrag_ipv6_hooks.c:68:9: error: 'struct sk_buff' has no member named '_nfct'

Both functions already have an #ifdef for this, so let's move the
check in there.

Fixes: 902d6a4c ("netfilter: nf_defrag: Skip defrag if NOTRACK is set")
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>

As a side-effect of adding the module option, we now get a section
mismatch warning:

WARNING: net/ipv4/netfilter/iptable_raw.o(.data+0x1c): Section mismatch in reference from the variable packet_raw to the function .init.text:iptable_raw_table_init()
The variable packet_raw references
the function __init iptable_raw_table_init()
If the reference is valid then annotate the
variable with __init* or __refdata (see linux/init.h) or name the variable:
*_template, *_timer, *_sht, *_ops, *_probe, *_probe_one, *_console

Apparently it's ok to link to a __net_init function from .rodata but not
from .data. We can address this by rearranging the logic so that the
structure is read-only again. Instead of writing to the .priority field
later, we have an extra copies of the structure with that flag. An added
advantage is that that we don't have writable function pointers with this
approach.

Fixes: 902d6a4c ("netfilter: nf_defrag: Skip defrag if NOTRACK is set")
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>

Map all lookup neigh keys to INADDR_ANY for loopback/point-to-point devices
to avoid making an entry for every remote ip the device needs to talk to.

This used the be the old behavior but became broken in a263b309
(ipv4: Make neigh lookups directly in output packet path) and later removed
in 0bb4087c (ipv4: Fix neigh lookup keying over loopback/point-to-point
devices) because it was broken.
Signed-off-by: NJim Westfall <jwestfall@surrealistic.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Since net could be obtained from RCU lists,
and there is a race with net destruction,
the patch converts net::count to refcount_t.

This provides sanity checks for the cases of
incrementing counter of already dead net,
when maybe_get_net() has to used instead
of get_net().

Drivers: allyesconfig and allmodconfig are OK.
Suggested-by: NEric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: NKirill Tkhai <ktkhai@virtuozzo.com>
Reviewed-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Commit 3765d35e ("net: ipv4: Convert inet_rtm_getroute to rcu
versions of route lookup") broke "ip route get" in the presence
of rules that specify iif lo.

Host-originated traffic always has iif lo, because
ip_route_output_key_hash and ip6_route_output_flags set the flow
iif to LOOPBACK_IFINDEX. Thus, putting "iif lo" in an ip rule is a
convenient way to select only originated traffic and not forwarded
traffic.

inet_rtm_getroute used to match these rules correctly because
even though it sets the flow iif to 0, it called
ip_route_output_key which overwrites iif with LOOPBACK_IFINDEX.
But now that it calls ip_route_output_key_hash_rcu, the ifindex
will remain 0 and not match the iif lo in the rule. As a result,
"ip route get" will return ENETUNREACH.

Fixes: 3765d35e ("net: ipv4: Convert inet_rtm_getroute to rcu versions of route lookup")
Tested: https://android.googlesource.com/kernel/tests/+/master/net/test/multinetwork_test.py passes again
Signed-off-by: NLorenzo Colitti <lorenzo@google.com>
Acked-by: NDavid Ahern <dsahern@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

conntrack defrag is needed only if some module like CONNTRACK or NAT
explicitly requests it. For plain forwarding scenarios, defrag is
not needed and can be skipped if NOTRACK is set in a rule.

Since conntrack defrag is currently higher priority than raw table,
setting NOTRACK is not sufficient. We need to move raw to a higher
priority for iptables only.

This is achieved by introducing a module parameter "raw_before_defrag"
which allows to change the priority of raw table to place it before
defrag. By default, the parameter is disabled and the priority of raw
table is NF_IP_PRI_RAW to support legacy behavior. If the module
parameter is enabled, then the priority of the raw table is set to
NF_IP_PRI_RAW_BEFORE_DEFRAG.
Signed-off-by: NSubash Abhinov Kasiviswanathan <subashab@codeaurora.org>
Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>

The clusterip target needs to register an arp mangling hook,
so make sure NF_ARP hooks are available.

Fixes: 2a95183a ("netfilter: don't allocate space for arp/bridge hooks unless needed")
Reported-by: Nkernel test robot <fengguang.wu@intel.com>
Signed-off-by: NFlorian Westphal <fw@strlen.de>
Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>

Fixes the following sparse warning:

net/ipv4/tcp.c:1736:6: warning:
 symbol 'tcp_recv_timestamp' was not declared. Should it be static?
Signed-off-by: NWei Yongjun <weiyongjun1@huawei.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The newly added NF_FLOW_TABLE options cause some build failures in
randconfig kernels:

- when CONFIG_NF_CONNTRACK is disabled, or is a loadable module but
  NF_FLOW_TABLE is built-in:

  In file included from net/netfilter/nf_flow_table.c:8:0:
  include/net/netfilter/nf_conntrack.h:59:22: error: field 'ct_general' has incomplete type
    struct nf_conntrack ct_general;
  include/net/netfilter/nf_conntrack.h: In function 'nf_ct_get':
  include/net/netfilter/nf_conntrack.h:148:15: error: 'const struct sk_buff' has no member named '_nfct'
  include/net/netfilter/nf_conntrack.h: In function 'nf_ct_put':
  include/net/netfilter/nf_conntrack.h:157:2: error: implicit declaration of function 'nf_conntrack_put'; did you mean 'nf_ct_put'? [-Werror=implicit-function-declaration]

  net/netfilter/nf_flow_table.o: In function `nf_flow_offload_work_gc':
  (.text+0x1540): undefined reference to `nf_ct_delete'

- when CONFIG_NF_TABLES is disabled:

  In file included from net/ipv6/netfilter/nf_flow_table_ipv6.c:13:0:
  include/net/netfilter/nf_tables.h: In function 'nft_gencursor_next':
  include/net/netfilter/nf_tables.h:1189:14: error: 'const struct net' has no member named 'nft'; did you mean 'nf'?

 - when CONFIG_NF_FLOW_TABLE_INET is enabled, but NF_FLOW_TABLE_IPV4
  or NF_FLOW_TABLE_IPV6 are not, or are loadable modules

  net/netfilter/nf_flow_table_inet.o: In function `nf_flow_offload_inet_hook':
  nf_flow_table_inet.c:(.text+0x94): undefined reference to `nf_flow_offload_ipv6_hook'
  nf_flow_table_inet.c:(.text+0x40): undefined reference to `nf_flow_offload_ip_hook'

- when CONFIG_NF_FLOW_TABLES is disabled, but the other options are
  enabled:

  net/netfilter/nf_flow_table_inet.o: In function `nf_flow_offload_inet_hook':
  nf_flow_table_inet.c:(.text+0x6c): undefined reference to `nf_flow_offload_ipv6_hook'
  net/netfilter/nf_flow_table_inet.o: In function `nf_flow_inet_module_exit':
  nf_flow_table_inet.c:(.exit.text+0x8): undefined reference to `nft_unregister_flowtable_type'
  net/netfilter/nf_flow_table_inet.o: In function `nf_flow_inet_module_init':
  nf_flow_table_inet.c:(.init.text+0x8): undefined reference to `nft_register_flowtable_type'
  net/ipv4/netfilter/nf_flow_table_ipv4.o: In function `nf_flow_ipv4_module_exit':
  nf_flow_table_ipv4.c:(.exit.text+0x8): undefined reference to `nft_unregister_flowtable_type'
  net/ipv4/netfilter/nf_flow_table_ipv4.o: In function `nf_flow_ipv4_module_init':
  nf_flow_table_ipv4.c:(.init.text+0x8): undefined reference to `nft_register_flowtable_type'

This adds additional Kconfig dependencies to ensure that NF_CONNTRACK and NF_TABLES
are always visible from NF_FLOW_TABLE, and that the internal dependencies between
the four new modules are met.

Fixes: 7c23b629 ("netfilter: flow table support for the mixed IPv4/IPv6 family")
Fixes: 09952107 ("netfilter: flow table support for IPv6")
Fixes: 97add9f0 ("netfilter: flow table support for IPv4")
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>

Remove the infrastructure to register/unregister nft_af_info structure,
this structure stores no useful information anymore.
Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>

Now that we have a single table list for each netns, we can get rid of
one pointer per family and the global afinfo list, thus, shrinking
struct netns for nftables that now becomes 64 bytes smaller.

And call __nft_release_afinfo() from __net_exit path accordingly to
release netnamespace objects on removal.
Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>

We already validate the hook through bitmask, so this check is
superfluous. When removing this, this patch is also fixing a bug in the
new flowtable codebase, since ctx->afi points to the table family
instead of the netdev family which is where the flowtable is really
hooked in.
Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>

Commit 8f659a03 ("net: ipv4: fix for a race condition in
raw_sendmsg") fixed the issue of possibly inconsistent ->hdrincl handling
due to concurrent updates by reading this bit-field member into a local
variable and using the thus stabilized value in subsequent tests.

However, aforementioned commit also adds the (correct) comment that

  /* hdrincl should be READ_ONCE(inet->hdrincl)
   * but READ_ONCE() doesn't work with bit fields
   */

because as it stands, the compiler is free to shortcut or even eliminate
the local variable at its will.

Note that I have not seen anything like this happening in reality and thus,
the concern is a theoretical one.

However, in order to be on the safe side, emulate a READ_ONCE() on the
bit-field by doing it on the local 'hdrincl' variable itself:

	int hdrincl = inet->hdrincl;
	hdrincl = READ_ONCE(hdrincl);

This breaks the chain in the sense that the compiler is not allowed
to replace subsequent reads from hdrincl with reloads from inet->hdrincl.

Fixes: 8f659a03 ("net: ipv4: fix for a race condition in raw_sendmsg")
Signed-off-by: NNicolai Stange <nstange@suse.de>
Reviewed-by: NStefano Brivio <sbrivio@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The GRO layer does not necessarily pull the complete headers
into the linear part of the skb, a part may remain on the
first page fragment. This can lead to a crash if we try to
pull the headers, so make sure we have them on the linear
part before pulling.

Fixes: 7785bba2 ("esp: Add a software GRO codepath")
Reported-by: syzbot+82bbd65569c49c6c0c4d@syzkaller.appspotmail.com
Signed-off-by: NSteffen Klassert <steffen.klassert@secunet.com>

The two conditions triggering BUG_ON() are somewhat unrelated:
the tcp_skb_pcount() check is meant to catch TSO flaws, the
second one checks sanity of congestion window bookkeeping.

Split them into two separate BUG_ON() assertions on two lines,
so that we know which one actually triggers, when they do.
Signed-off-by: NStefano Brivio <sbrivio@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch adds the IPv6 flow table type, that implements the datapath
flow table to forward IPv6 traffic.
Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>

This patch adds the IPv4 flow table type, that implements the datapath
flow table to forward IPv4 traffic. Rationale is:

1) Look up for the packet in the flow table, from the ingress hook.
2) If there's a hit, decrement ttl and pass it on to the neighbour layer
   for transmission.
3) If there's a miss, packet is passed up to the classic forwarding
   path.

This patch also supports layer 3 source and destination NAT.
Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>

Users cannot forge malformed IPv4/IPv6 headers via raw sockets that they
can inject into the stack. Specifically, not for IPv4 since 55888dfb
("AF_RAW: Augment raw_send_hdrinc to expand skb to fit iphdr->ihl
(v2)"). IPv6 raw sockets also ensure that packets have a well-formed
IPv6 header available in the skbuff.

At quick glance, br_netfilter also validates layer 3 headers and it
drops malformed both IPv4 and IPv6 packets.

Therefore, let's remove this defensive check all over the place.
Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>

This abstraction has no clients anymore, remove it.

This is what remains from previous authors, so correct copyright
statement after recent modifications and code removal.
Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>

This is only needed by nf_queue, place this code where it belongs.
Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>

We cannot make a direct call to nf_ip6_reroute() because that would result
in autoloading the 'ipv6' module because of symbol dependencies.
Therefore, define reroute indirection in nf_ipv6_ops where this really
belongs to.

For IPv4, we can indeed make a direct function call, which is faster,
given IPv4 is built-in in the networking code by default. Still,
CONFIG_INET=n and CONFIG_NETFILTER=y is possible, so define empty inline
stub for IPv4 in such case.
Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>

We cannot make a direct call to nf_ip6_route() because that would result
in autoloading the 'ipv6' module because of symbol dependencies.
Therefore, define route indirection in nf_ipv6_ops where this really
belongs to.

For IPv4, we can indeed make a direct function call, which is faster,
given IPv4 is built-in in the networking code by default. Still,
CONFIG_INET=n and CONFIG_NETFILTER=y is possible, so define empty inline
stub for IPv4 in such case.
Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>

This is only used by nf_queue.c and this function comes with no symbol
dependencies with IPv6, it just refers to structure layouts. Therefore,
we can replace it by a direct function call from where it belongs.
Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>

We cannot make a direct call to nf_ip6_checksum_partial() because that
would result in autoloading the 'ipv6' module because of symbol
dependencies.  Therefore, define checksum_partial indirection in
nf_ipv6_ops where this really belongs to.

For IPv4, we can indeed make a direct function call, which is faster,
given IPv4 is built-in in the networking code by default. Still,
CONFIG_INET=n and CONFIG_NETFILTER=y is possible, so define empty inline
stub for IPv4 in such case.
Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>

We cannot make a direct call to nf_ip6_checksum() because that would
result in autoloading the 'ipv6' module because of symbol dependencies.
Therefore, define checksum indirection in nf_ipv6_ops where this really
belongs to.

For IPv4, we can indeed make a direct function call, which is faster,
given IPv4 is built-in in the networking code by default. Still,
CONFIG_INET=n and CONFIG_NETFILTER=y is possible, so define empty inline
stub for IPv4 in such case.
Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>

They don't belong to the family definition, move them to the filter
chain type definition instead.
Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>

Since NFPROTO_INET is handled from the core, we don't need to maintain
extra infrastructure in nf_tables to handle the double hook
registration, one for IPv4 and another for IPv6.
Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>