Provide a driver api for reporting device statistics required by the
"Implementation Requirements" section of the PSP Architecture
Specification. Use a warning to ensure drivers report stats required
by the spec.
Signed-off-by: Daniel Zahka <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Jakub Kicinski <[email protected]>
Track and report stats common to all psp devices from the core. A
'stale-event' is when the core marks the rx state of an active
psp_assoc as incapable of authenticating psp encapsulated data.
Signed-off-by: Daniel Zahka <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Jakub Kicinski <[email protected]>
Rx path may be passing around unreferenced sockets, which means
that skb_set_owner_edemux() may not set skb->sk and PSP will crash:
KASAN: null-ptr-deref in range [0x0000000000000010-0x0000000000000017]
RIP: 0010:psp_reply_set_decrypted (./include/net/psp/functions.h:132 net/psp/psp_sock.c:287)
tcp_v6_send_response.constprop.0 (net/ipv6/tcp_ipv6.c:979)
tcp_v6_send_reset (net/ipv6/tcp_ipv6.c:1140 (discriminator 1))
tcp_v6_do_rcv (net/ipv6/tcp_ipv6.c:1683)
tcp_v6_rcv (net/ipv6/tcp_ipv6.c:1912)
Fixes: 659a2899a5 ("tcp: add datapath logic for PSP with inline key exchange")
Reviewed-by: Kuniyuki Iwashima <[email protected]>
Reviewed-by: Eric Dumazet <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Jakub Kicinski <[email protected]>
Using flags to check sk_state only makes sense to check for a subset
of states in parallel e.g. sk_fullsock(). We are not doing that
here. Compare for individual states directly.
Signed-off-by: Daniel Zahka <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Jakub Kicinski <[email protected]>
It is weird to cast to a timewait_sock before checking sk_state, even
if the use is after such a check. Remove the tw local variable, and
use inet_twsk() directly in the timewait branch.
Signed-off-by: Daniel Zahka <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Jakub Kicinski <[email protected]>
Create a new function psp_encapsulate(), which takes a TCP packet and
PSP encapsulates it according to the "Transport Mode Packet Format"
section of the PSP Architecture Specification.
psp_encapsulate() does not push a PSP trailer onto the skb. Both IPv6
and IPv4 are supported. Virtualization cookie is not included.
Reviewed-by: Willem de Bruijn <[email protected]>
Signed-off-by: Raed Salem <[email protected]>
Signed-off-by: Rahul Rameshbabu <[email protected]>
Signed-off-by: Cosmin Ratiu <[email protected]>
Co-developed-by: Daniel Zahka <[email protected]>
Signed-off-by: Daniel Zahka <[email protected]>
Reviewed-by: Eric Dumazet <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Paolo Abeni <[email protected]>
There is a (somewhat theoretical in absence of multi-host support)
possibility that another entity will rotate the key and we won't
know. This may lead to accepting packets with matching SPI but
which used different crypto keys than we expected.
The PSP Architecture specification mentions that an implementation
should track device key generation when device keys are managed by the
NIC. Some PSP implementations may opt to include this key generation
state in decryption metadata each time a device key is used to decrypt
a packet. If that is the case, that key generation counter can also be
used when policy checking a decrypted skb against a psp_assoc. This is
an optional feature that is not explicitly part of the PSP spec, but
can provide additional security in the case where an attacker may have
the ability to force key rotations faster than rekeying can occur.
Since we're tracking "key generations" more explicitly now,
maintain different lists for associations from different generations.
This way we can catch stale associations (the user space should
listen to rotation notifications and change the keys).
Drivers can "opt out" of generation tracking by setting
the generation value to 0.
Reviewed-by: Willem de Bruijn <[email protected]>
Signed-off-by: Jakub Kicinski <[email protected]>
Signed-off-by: Daniel Zahka <[email protected]>
Reviewed-by: Eric Dumazet <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Paolo Abeni <[email protected]>
PSP eats 40B of header space. Adjust MSS appropriately.
We can either modify tcp_mtu_to_mss() / tcp_mss_to_mtu()
or reuse icsk_ext_hdr_len. The former option is more TCP
specific and has runtime overhead. The latter is a bit
of a hack as PSP is not an ext_hdr. If one squints hard
enough, UDP encap is just a more practical version of
IPv6 exthdr, so go with the latter. Happy to change.
Reviewed-by: Willem de Bruijn <[email protected]>
Signed-off-by: Jakub Kicinski <[email protected]>
Signed-off-by: Daniel Zahka <[email protected]>
Reviewed-by: Eric Dumazet <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Paolo Abeni <[email protected]>
Add the ability to install PSP Rx and Tx crypto keys on TCP
connections. Netlink ops are provided for both operations.
Rx side combines allocating a new Rx key and installing it
on the socket. Theoretically these are separate actions,
but in practice they will always be used one after the
other. We can add distinct "alloc" and "install" ops later.
Reviewed-by: Willem de Bruijn <[email protected]>
Signed-off-by: Jakub Kicinski <[email protected]>
Co-developed-by: Daniel Zahka <[email protected]>
Signed-off-by: Daniel Zahka <[email protected]>
Reviewed-by: Eric Dumazet <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Paolo Abeni <[email protected]>
Rotating the device key is a key part of the PSP protocol design.
Some external daemon needs to do it once a day, or so.
Add a netlink op to perform this operation.
Add a notification group for informing users that key has been
rotated and they should rekey (next rotation will cut them off).
Reviewed-by: Willem de Bruijn <[email protected]>
Signed-off-by: Jakub Kicinski <[email protected]>
Signed-off-by: Daniel Zahka <[email protected]>
Reviewed-by: Eric Dumazet <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Paolo Abeni <[email protected]>
Add validation points and state propagation to support PSP key
exchange inline, on TCP connections. The expectation is that
application will use some well established mechanism like TLS
handshake to establish a secure channel over the connection and
if both endpoints are PSP-capable - exchange and install PSP keys.
Because the connection can existing in PSP-unsecured and PSP-secured
state we need to make sure that there are no race conditions or
retransmission leaks.
On Tx - mark packets with the skb->decrypted bit when PSP key
is at the enqueue time. Drivers should only encrypt packets with
this bit set. This prevents retransmissions getting encrypted when
original transmission was not. Similarly to TLS, we'll use
sk->sk_validate_xmit_skb to make sure PSP skbs can't "escape"
via a PSP-unaware device without being encrypted.
On Rx - validation is done under socket lock. This moves the validation
point later than xfrm, for example. Please see the documentation patch
for more details on the flow of securing a connection, but for
the purpose of this patch what's important is that we want to
enforce the invariant that once connection is secured any skb
in the receive queue has been encrypted with PSP.
Add GRO and coalescing checks to prevent PSP authenticated data from
being combined with cleartext data, or data with non-matching PSP
state. On Rx, check skb's with psp_skb_coalesce_diff() at points
before psp_sk_rx_policy_check(). After skb's are policy checked and on
the socket receive queue, skb_cmp_decrypted() is sufficient for
checking for coalescable PSP state. On Tx, tcp_write_collapse_fence()
should be called when transitioning a socket into PSP Tx state to
prevent data sent as cleartext from being coalesced with PSP
encapsulated data.
This change only adds the validation points, for ease of review.
Subsequent change will add the ability to install keys, and flesh
the enforcement logic out
Reviewed-by: Willem de Bruijn <[email protected]>
Signed-off-by: Jakub Kicinski <[email protected]>
Co-developed-by: Daniel Zahka <[email protected]>
Signed-off-by: Daniel Zahka <[email protected]>
Reviewed-by: Eric Dumazet <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Paolo Abeni <[email protected]>
Add a netlink family for PSP and allow drivers to register support.
The "PSP device" is its own object. This allows us to perform more
flexible reference counting / lifetime control than if PSP information
was part of net_device. In the future we should also be able
to "delegate" PSP access to software devices, such as *vlan, veth
or netkit more easily.
Reviewed-by: Willem de Bruijn <[email protected]>
Signed-off-by: Jakub Kicinski <[email protected]>
Signed-off-by: Daniel Zahka <[email protected]>
Reviewed-by: Eric Dumazet <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Paolo Abeni <[email protected]>
Jakub Kicinski