linux-stable.git/net/ipv4/af_inet.c, branch linux-5.8.y Linux kernel stable tree Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next 2020-05-23T01:30:34+00:00 David S. Miller davem@davemloft.net 2020-05-23T01:30:34+00:00 a152b85984a03e7f83b9d8bcf908c29597d898fc 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routing helpers, from Stanislav Fomichev, Andrii Nakryiko and Alan Maguire. 6) Conversion of BPF tracing samples outdated internal BPF loader to use libbpf API instead, from Daniel T. Lee. 7) Follow-up to BPF kernel test infrastructure in order to fix a flake in the XDP selftests,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 <davem@davemloft.net> 
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 <davem@davemloft.net>
bpf: Add get{peer, sock}name attach types for sock_addr 2020-05-19T18:32:04+00:00 Daniel Borkmann daniel@iogearbox.net 2020-05-18T22:45:45+00:00 1b66d253610c7f8f257103808a9460223a087469 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 <daniel@iogearbox.net> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Andrii Nakryiko <andriin@fb.com> Acked-by: Andrey Ignatov <rdna@fb.com> Link: https://lore.kernel.org/bpf/61a479d759b2482ae3efb45546490bacd796a220.1589841594.git.daniel@iogearbox.net 
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 <daniel@iogearbox.net>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Acked-by: Andrey Ignatov <rdna@fb.com>
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 Christoph Hellwig hch@lst.de 2020-05-18T06:28:08+00:00 dc13c8761c91c06acd3d98cd107f371cba9811b9 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 <hch@lst.de> Signed-off-by: David S. Miller <davem@davemloft.net> 
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 <hch@lst.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
bpf: Allow any port in bpf_bind helper 2020-05-08T22:48:20+00:00 Stanislav Fomichev sdf@google.com 2020-05-08T17:46:11+00:00 8086fbaf49345f988deec539ec8e182b02914401 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 <sdf@google.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Andrey Ignatov <rdna@fb.com> Acked-by: Martin KaFai Lau <kafai@fb.com> Link: https://lore.kernel.org/bpf/20200508174611.228805-5-sdf@google.com 
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 <sdf@google.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Andrey Ignatov <rdna@fb.com>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/bpf/20200508174611.228805-5-sdf@google.com
net: Refactor arguments of inet{,6}_bind 2020-05-08T22:48:20+00:00 Stanislav Fomichev sdf@google.com 2020-05-08T17:46:10+00:00 cb0721c7e200750907bb8ef59b12646a5cb2dadf The intent is to add an additional bind parameter in the next commit. Instead of adding another argument, let's convert all existing flag arguments into an extendable bit field. No functional changes. Signed-off-by: Stanislav Fomichev <sdf@google.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Andrey Ignatov <rdna@fb.com> Acked-by: Martin KaFai Lau <kafai@fb.com> Link: https://lore.kernel.org/bpf/20200508174611.228805-4-sdf@google.com 
The intent is to add an additional bind parameter in the next commit.
Instead of adding another argument, let's convert all existing
flag arguments into an extendable bit field.

No functional changes.

Signed-off-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Andrey Ignatov <rdna@fb.com>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/bpf/20200508174611.228805-4-sdf@google.com
net: ipv4: add sysctl for nexthop api compatibility mode 2020-04-28T19:50:37+00:00 Roopa Prabhu roopa@cumulusnetworks.com 2020-04-27T20:56:46+00:00 4f80116d3df3b23ee4b83ea8557629e1799bc230 Current route nexthop API maintains user space compatibility with old route API by default. Dumps and netlink notifications support both new and old API format. In systems which have moved to the new API, this compatibility mode cancels some of the performance benefits provided by the new nexthop API. This patch adds new sysctl nexthop_compat_mode which is on by default but provides the ability to turn off compatibility mode allowing systems to run entirely with the new routing API. Old route API behaviour and support is not modified by this sysctl. Uses a single sysctl to cover both ipv4 and ipv6 following other sysctls. Covers dumps and delete notifications as suggested by David Ahern. Signed-off-by: Roopa Prabhu <roopa@cumulusnetworks.com> Reviewed-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
Current route nexthop API maintains user space compatibility
with old route API by default. Dumps and netlink notifications
support both new and old API format. In systems which have
moved to the new API, this compatibility mode cancels some
of the performance benefits provided by the new nexthop API.

This patch adds new sysctl nexthop_compat_mode which is on
by default but provides the ability to turn off compatibility
mode allowing systems to run entirely with the new routing
API. Old route API behaviour and support is not modified by this
sysctl.

Uses a single sysctl to cover both ipv4 and ipv6 following
other sysctls. Covers dumps and delete notifications as
suggested by David Ahern.

Signed-off-by: Roopa Prabhu <roopa@cumulusnetworks.com>
Reviewed-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
net: ipv4: remove redundant assignment to variable rc 2020-04-20T23:26:58+00:00 Colin Ian King colin.king@canonical.com 2020-04-20T21:51:49+00:00 b6246f4d8d0778fd045b84dbd7fc5aadd8f3136e The variable rc is being assigned with a value that is never read and it is being updated later with a new value. The initialization is redundant and can be removed. Addresses-Coverity: ("Unused value") Signed-off-by: Colin Ian King <colin.king@canonical.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
The variable rc is being assigned with a value that is never read
and it is being updated later with a new value. The initialization is
redundant and can be removed.

Addresses-Coverity: ("Unused value")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
mptcp: add and use MIB counter infrastructure 2020-03-30T05:14:49+00:00 Florian Westphal fw@strlen.de 2020-03-27T21:48:50+00:00 fc518953bc9c8d7d33c6ab261995f5038f3c87f9 Exported via same /proc file as the Linux TCP MIB counters, so "netstat -s" or "nstat" will show them automatically. The MPTCP MIB counters are allocated in a distinct pcpu area in order to avoid bloating/wasting TCP pcpu memory. Counters are allocated once the first MPTCP socket is created in a network namespace and free'd on exit. If no sockets have been allocated, all-zero mptcp counters are shown. The MIB counter list is taken from the multipath-tcp.org kernel, but only a few counters have been picked up so far. The counter list can be increased at any time later on. v2 -> v3: - remove 'inline' in foo.c files (David S. Miller) Co-developed-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
Exported via same /proc file as the Linux TCP MIB counters, so "netstat -s"
or "nstat" will show them automatically.

The MPTCP MIB counters are allocated in a distinct pcpu area in order to
avoid bloating/wasting TCP pcpu memory.

Counters are allocated once the first MPTCP socket is created in a
network namespace and free'd on exit.

If no sockets have been allocated, all-zero mptcp counters are shown.

The MIB counter list is taken from the multipath-tcp.org kernel, but
only a few counters have been picked up so far.  The counter list can
be increased at any time later on.

v2 -> v3:
 - remove 'inline' in foo.c files (David S. Miller)

Co-developed-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
inet: Use fallthrough; 2020-03-12T22:55:00+00:00 Joe Perches joe@perches.com 2020-03-12T22:50:22+00:00 a8eceea84a3a3504e42f6495cf462027c5d19cb0 Convert the various uses of fallthrough comments to fallthrough; Done via script Link: https://lore.kernel.org/lkml/b56602fcf79f849e733e7b521bb0e17895d390fa.1582230379.git.joe@perches.com/ And by hand: net/ipv6/ip6_fib.c has a fallthrough comment outside of an #ifdef block that causes gcc to emit a warning if converted in-place. So move the new fallthrough; inside the containing #ifdef/#endif too. Signed-off-by: Joe Perches <joe@perches.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
Convert the various uses of fallthrough comments to fallthrough;

Done via script
Link: https://lore.kernel.org/lkml/b56602fcf79f849e733e7b521bb0e17895d390fa.1582230379.git.joe@perches.com/

And by hand:

net/ipv6/ip6_fib.c has a fallthrough comment outside of an #ifdef block
that causes gcc to emit a warning if converted in-place.

So move the new fallthrough; inside the containing #ifdef/#endif too.

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
net: port < inet_prot_sock(net) --> inet_port_requires_bind_service(net, port) 2019-11-26T21:20:46+00:00 Maciej Żenczykowski maze@google.com 2019-11-25T23:37:04+00:00 82f31ebf61bed3077c9935308e0a4b6c44842c5a Note that the sysctl write accessor functions guarantee that: net->ipv4.sysctl_ip_prot_sock <= net->ipv4.ip_local_ports.range[0] invariant is maintained, and as such the max() in selinux hooks is actually spurious. ie. even though if (snum < max(inet_prot_sock(sock_net(sk)), low) || snum > high) { per logic is the same as if ((snum < inet_prot_sock(sock_net(sk)) && snum < low) || snum > high) { it is actually functionally equivalent to: if (snum < low || snum > high) { which is equivalent to: if (snum < inet_prot_sock(sock_net(sk)) || snum < low || snum > high) { even though the first clause is spurious. But we want to hold on to it in case we ever want to change what what inet_port_requires_bind_service() means (for example by changing it from a, by default, [0..1024) range to some sort of set). Test: builds, git 'grep inet_prot_sock' finds no other references Cc: Eric Dumazet <edumazet@google.com> Signed-off-by: Maciej Żenczykowski <maze@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
Note that the sysctl write accessor functions guarantee that:
  net->ipv4.sysctl_ip_prot_sock <= net->ipv4.ip_local_ports.range[0]
invariant is maintained, and as such the max() in selinux hooks is actually spurious.

ie. even though
  if (snum < max(inet_prot_sock(sock_net(sk)), low) || snum > high) {
per logic is the same as
  if ((snum < inet_prot_sock(sock_net(sk)) && snum < low) || snum > high) {
it is actually functionally equivalent to:
  if (snum < low || snum > high) {
which is equivalent to:
  if (snum < inet_prot_sock(sock_net(sk)) || snum < low || snum > high) {
even though the first clause is spurious.

But we want to hold on to it in case we ever want to change what what
inet_port_requires_bind_service() means (for example by changing
it from a, by default, [0..1024) range to some sort of set).

Test: builds, git 'grep inet_prot_sock' finds no other references
Cc: Eric Dumazet <edumazet@google.com>
Signed-off-by: Maciej Żenczykowski <maze@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>