linux.git/net/ipv4/af_inet.c, branch v5.11

bpf: Allow bpf_{s,g}etsockopt from cgroup bind{4,6} hooks

2020-12-02T21:25:11+00:00

I have to now lock/unlock socket for the bind hook execution.
That shouldn't cause any overhead because the socket is unbound
and shouldn't receive any traffic.

Signed-off-by: Stanislav Fomichev 
Signed-off-by: Alexei Starovoitov 
Acked-by: Andrey Ignatov 
Link: https://lore.kernel.org/bpf/20201202172516.3483656-3-sdf@google.com

io_uring: allow tcp ancillary data for __sys_recvmsg_sock()

2020-08-24T23:16:06+00:00

For TCP tx zero-copy, the kernel notifies the process of completions by
queuing completion notifications on the socket error queue. This patch
allows reading these notifications via recvmsg to support TCP tx
zero-copy.

Ancillary data was originally disallowed due to privilege escalation
via io_uring's offloading of sendmsg() onto a kernel thread with kernel
credentials (https://crbug.com/project-zero/1975). So, we must ensure
that the socket type is one where the ancillary data types that are
delivered on recvmsg are plain data (no file descriptors or values that
are translated based on the identity of the calling process).

This was tested by using io_uring to call recvmsg on the MSG_ERRQUEUE
with tx zero-copy enabled. Before this patch, we received -EINVALID from
this specific code path. After this patch, we could read tcp tx
zero-copy completion notifications from the MSG_ERRQUEUE.

Signed-off-by: Soheil Hassas Yeganeh 
Signed-off-by: Arjun Roy 
Acked-by: Eric Dumazet 
Reviewed-by: Jann Horn 
Reviewed-by: Jens Axboe 
Signed-off-by: Luke Hsiao 
Signed-off-by: David S. Miller

net: remove compat_sock_common_{get,set}sockopt

2020-07-20T01:16:40+00:00

Add the compat handling to sock_common_{get,set}sockopt instead,
keyed of in_compat_syscall().  This allow to remove the now unused
->compat_{get,set}sockopt methods from struct proto_ops.

Signed-off-by: Christoph Hellwig 
Acked-by: Matthieu Baerts 
Acked-by: Stefan Schmidt 
Signed-off-by: David S. Miller

bpf: Add BPF_CGROUP_INET_SOCK_RELEASE hook

2020-07-07T23:03:31+00:00

Sometimes it's handy to know when the socket gets freed. In
particular, we'd like to try to use a smarter allocation of
ports for bpf_bind and explore the possibility of limiting
the number of SOCK_DGRAM sockets the process can have.

Implement BPF_CGROUP_INET_SOCK_RELEASE hook that triggers on
inet socket release. It triggers only for userspace sockets
(not in-kernel ones) and therefore has the same semantics as
the existing BPF_CGROUP_INET_SOCK_CREATE.

Signed-off-by: Stanislav Fomichev 
Signed-off-by: Daniel Borkmann 
Acked-by: Andrii Nakryiko 
Link: https://lore.kernel.org/bpf/20200706230128.4073544-2-sdf@google.com

udp: move gro declarations to net/udp.h

2020-06-24T03:10:15+00:00

This removes following warnings :
  CC      net/ipv4/udp_offload.o
net/ipv4/udp_offload.c:504:17: warning: no previous prototype for 'udp4_gro_receive' [-Wmissing-prototypes]
  504 | struct sk_buff *udp4_gro_receive(struct list_head *head, struct sk_buff *skb)
      |                 ^~~~~~~~~~~~~~~~
net/ipv4/udp_offload.c:584:29: warning: no previous prototype for 'udp4_gro_complete' [-Wmissing-prototypes]
  584 | INDIRECT_CALLABLE_SCOPE int udp4_gro_complete(struct sk_buff *skb, int nhoff)
      |                             ^~~~~~~~~~~~~~~~~

  CHECK   net/ipv6/udp_offload.c
net/ipv6/udp_offload.c:115:16: warning: symbol 'udp6_gro_receive' was not declared. Should it be static?
net/ipv6/udp_offload.c:148:29: warning: symbol 'udp6_gro_complete' was not declared. Should it be static?
  CC      net/ipv6/udp_offload.o
net/ipv6/udp_offload.c:115:17: warning: no previous prototype for 'udp6_gro_receive' [-Wmissing-prototypes]
  115 | struct sk_buff *udp6_gro_receive(struct list_head *head, struct sk_buff *skb)
      |                 ^~~~~~~~~~~~~~~~
net/ipv6/udp_offload.c:148:29: warning: no previous prototype for 'udp6_gro_complete' [-Wmissing-prototypes]
  148 | INDIRECT_CALLABLE_SCOPE int udp6_gro_complete(struct sk_buff *skb, int nhoff)
      |                             ^~~~~~~~~~~~~~~~~
Signed-off-by: Eric Dumazet 

Signed-off-by: David S. Miller

net: move tcp gro declarations to net/tcp.h

2020-06-24T03:10:15+00:00

This patch removes following (C=1 W=1) warnings for CONFIG_RETPOLINE=y :

net/ipv4/tcp_offload.c:306:16: warning: symbol 'tcp4_gro_receive' was not declared. Should it be static?
net/ipv4/tcp_offload.c:306:17: warning: no previous prototype for 'tcp4_gro_receive' [-Wmissing-prototypes]
net/ipv4/tcp_offload.c:319:29: warning: symbol 'tcp4_gro_complete' was not declared. Should it be static?
net/ipv4/tcp_offload.c:319:29: warning: no previous prototype for 'tcp4_gro_complete' [-Wmissing-prototypes]
  CHECK   net/ipv6/tcpv6_offload.c
net/ipv6/tcpv6_offload.c:16:16: warning: symbol 'tcp6_gro_receive' was not declared. Should it be static?
net/ipv6/tcpv6_offload.c:29:29: warning: symbol 'tcp6_gro_complete' was not declared. Should it be static?
  CC      net/ipv6/tcpv6_offload.o
net/ipv6/tcpv6_offload.c:16:17: warning: no previous prototype for 'tcp6_gro_receive' [-Wmissing-prototypes]
   16 | struct sk_buff *tcp6_gro_receive(struct list_head *head, struct sk_buff *skb)
      |                 ^~~~~~~~~~~~~~~~
net/ipv6/tcpv6_offload.c:29:29: warning: no previous prototype for 'tcp6_gro_complete' [-Wmissing-prototypes]
   29 | INDIRECT_CALLABLE_SCOPE int tcp6_gro_complete(struct sk_buff *skb, int thoff)
      |                             ^~~~~~~~~~~~~~~~~

Signed-off-by: Eric Dumazet 
Signed-off-by: David S. Miller

Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next

2020-05-23T01:30:34+00:00

Daniel Borkmann says:

====================
pull-request: bpf-next 2020-05-23

The following pull-request contains BPF updates for your *net-next* tree.

We've added 50 non-merge commits during the last 8 day(s) which contain
a total of 109 files changed, 2776 insertions(+), 2887 deletions(-).

The main changes are:

1) Add a new AF_XDP buffer allocation API to the core in order to help
   lowering the bar for drivers adopting AF_XDP support. i40e, ice, ixgbe
   as well as mlx5 have been moved over to the new API and also gained a
   small improvement in performance, from Björn Töpel and Magnus Karlsson.

2) Add getpeername()/getsockname() attach types for BPF sock_addr programs
   in order to allow for e.g. reverse translation of load-balancer backend
   to service address/port tuple from a connected peer, from Daniel Borkmann.

3) Improve the BPF verifier is_branch_taken() logic to evaluate pointers
   being non-NULL, e.g. if after an initial test another non-NULL test on
   that pointer follows in a given path, then it can be pruned right away,
   from John Fastabend.

4) Larger rework of BPF sockmap selftests to make output easier to understand
   and to reduce overall runtime as well as adding new BPF kTLS selftests
   that run in combination with sockmap, also from John Fastabend.

5) Batch of misc updates to BPF selftests including fixing up test_align
   to match verifier output again and moving it under test_progs, allowing
   bpf_iter selftest to compile on machines with older vmlinux.h, and
   updating config options for lirc and v6 segment routing helpers, from
   Stanislav Fomichev, Andrii Nakryiko and Alan Maguire.

6) Conversion of BPF tracing samples outdated internal BPF loader to use
   libbpf API instead, from Daniel T. Lee.

7) Follow-up to BPF kernel test infrastructure in order to fix a flake in
   the XDP selftests, from Jesper Dangaard Brouer.

8) Minor improvements to libbpf's internal hashmap implementation, from
   Ian Rogers.
====================

Signed-off-by: David S. Miller

bpf: Add get{peer, sock}name attach types for sock_addr

2020-05-19T18:32:04+00:00

As stated in 983695fa6765 ("bpf: fix unconnected udp hooks"), the objective
for the existing cgroup connect/sendmsg/recvmsg/bind BPF hooks is to be
transparent to applications. In Cilium we make use of these hooks [0] in
order to enable E-W load balancing for existing Kubernetes service types
for all Cilium managed nodes in the cluster. Those backends can be local
or remote. The main advantage of this approach is that it operates as close
as possible to the socket, and therefore allows to avoid packet-based NAT
given in connect/sendmsg/recvmsg hooks we only need to xlate sock addresses.

This also allows to expose NodePort services on loopback addresses in the
host namespace, for example. As another advantage, this also efficiently
blocks bind requests for applications in the host namespace for exposed
ports. However, one missing item is that we also need to perform reverse
xlation for inet{,6}_getname() hooks such that we can return the service
IP/port tuple back to the application instead of the remote peer address.

The vast majority of applications does not bother about getpeername(), but
in a few occasions we've seen breakage when validating the peer's address
since it returns unexpectedly the backend tuple instead of the service one.
Therefore, this trivial patch allows to customise and adds a getpeername()
as well as getsockname() BPF cgroup hook for both IPv4 and IPv6 in order
to address this situation.

Simple example:

  # ./cilium/cilium service list
  ID   Frontend     Service Type   Backend
  1    1.2.3.4:80   ClusterIP      1 => 10.0.0.10:80

Before; curl's verbose output example, no getpeername() reverse xlation:

  # curl --verbose 1.2.3.4
  * Rebuilt URL to: 1.2.3.4/
  *   Trying 1.2.3.4...
  * TCP_NODELAY set
  * Connected to 1.2.3.4 (10.0.0.10) port 80 (#0)
  > GET / HTTP/1.1
  > Host: 1.2.3.4
  > User-Agent: curl/7.58.0
  > Accept: */*
  [...]

After; with getpeername() reverse xlation:

  # curl --verbose 1.2.3.4
  * Rebuilt URL to: 1.2.3.4/
  *   Trying 1.2.3.4...
  * TCP_NODELAY set
  * Connected to 1.2.3.4 (1.2.3.4) port 80 (#0)
  > GET / HTTP/1.1
  >  Host: 1.2.3.4
  > User-Agent: curl/7.58.0
  > Accept: */*
  [...]

Originally, I had both under a BPF_CGROUP_INET{4,6}_GETNAME type and exposed
peer to the context similar as in inet{,6}_getname() fashion, but API-wise
this is suboptimal as it always enforces programs having to test for ctx->peer
which can easily be missed, hence BPF_CGROUP_INET{4,6}_GET{PEER,SOCK}NAME split.
Similarly, the checked return code is on tnum_range(1, 1), but if a use case
comes up in future, it can easily be changed to return an error code instead.
Helper and ctx member access is the same as with connect/sendmsg/etc hooks.

  [0] https://github.com/cilium/cilium/blob/master/bpf/bpf_sock.c

Signed-off-by: Daniel Borkmann 
Signed-off-by: Alexei Starovoitov 
Acked-by: Andrii Nakryiko 
Acked-by: Andrey Ignatov 
Link: https://lore.kernel.org/bpf/61a479d759b2482ae3efb45546490bacd796a220.1589841594.git.daniel@iogearbox.net

ipv4,appletalk: move SIOCADDRT and SIOCDELRT handling into ->compat_ioctl

2020-05-19T00:35:02+00:00

To prepare removing the global routing_ioctl hack start lifting the code
into the ipv4 and appletalk ->compat_ioctl handlers.  Unlike the existing
handler we don't bother copying in the name - there are no compat issues for
char arrays.

Signed-off-by: Christoph Hellwig 
Signed-off-by: David S. Miller

bpf: Allow any port in bpf_bind helper

2020-05-08T22:48:20+00:00

We want to have a tighter control on what ports we bind to in
the BPF_CGROUP_INET{4,6}_CONNECT hooks even if it means
connect() becomes slightly more expensive. The expensive part
comes from the fact that we now need to call inet_csk_get_port()
that verifies that the port is not used and allocates an entry
in the hash table for it.

Since we can't rely on "snum || !bind_address_no_port" to prevent
us from calling POST_BIND hook anymore, let's add another bind flag
to indicate that the call site is BPF program.

v5:
* fix wrong AF_INET (should be AF_INET6) in the bpf program for v6

v3:
* More bpf_bind documentation refinements (Martin KaFai Lau)
* Add UDP tests as well (Martin KaFai Lau)
* Don't start the thread, just do socket+bind+listen (Martin KaFai Lau)

v2:
* Update documentation (Andrey Ignatov)
* Pass BIND_FORCE_ADDRESS_NO_PORT conditionally (Andrey Ignatov)

Signed-off-by: Stanislav Fomichev 
Signed-off-by: Daniel Borkmann 
Acked-by: Andrey Ignatov 
Acked-by: Martin KaFai Lau 
Link: https://lore.kernel.org/bpf/20200508174611.228805-5-sdf@google.com