[PATCH 29/33] rxrpc: add rxrpc_sock_set_min_security_level

Christoph Hellwig
2020-05-20T19:57:13Z

Add a helper to directly set the RXRPC_MIN_SECURITY_LEVEL sockopt from
kernel space without going through a fake uaccess.

Thanks to David Howells for the documentation updates.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
Documentation/networking/rxrpc.rst | 13 +++++++++++--
fs/afs/rxrpc.c | 6 ++----
include/net/af_rxrpc.h | 2 ++
net/rxrpc/af_rxrpc.c | 13 +++++++++++++
4 files changed, 28 insertions(+), 6 deletions(-)

diff --git a/Documentation/networking/rxrpc.rst b/Documentation/networking/rxrpc.rst
index 5ad35113d0f46..68552b92dc442 100644
--- a/Documentation/networking/rxrpc.rst
+++ b/Documentation/networking/rxrpc.rst
@@ -477,7 +477,7 @@ AF_RXRPC sockets support a few socket options at the SOL_RXRPC level:
Encrypted checksum plus packet padded and first eight bytes of packet
encrypted - which includes the actual packet length.

- (c) RXRPC_SECURITY_ENCRYPTED
+ (c) RXRPC_SECURITY_ENCRYPT

Encrypted checksum plus entire packet padded and encrypted, including
actual packet length.
@@ -578,7 +578,7 @@ A client would issue an operation by:
This issues a request_key() to get the key representing the security
context. The minimum security level can be set::

- unsigned int sec = RXRPC_SECURITY_ENCRYPTED;
+ unsigned int sec = RXRPC_SECURITY_ENCRYPT;
setsockopt(client, SOL_RXRPC, RXRPC_MIN_SECURITY_LEVEL,
&sec, sizeof(sec));

@@ -1090,6 +1090,15 @@ The kernel interface functions are as follows:
jiffies). In the event of the timeout occurring, the call will be
aborted and -ETIME or -ETIMEDOUT will be returned.

+ (#) Apply the RXRPC_MIN_SECURITY_LEVEL sockopt to a socket from within in the
+ kernel::
+
+ int rxrpc_sock_set_min_security_level(struct sock *sk,
+ unsigned int val);
+
+ This specifies the minimum security level required for calls on this
+ socket.
+

Configurable Parameters
=======================
diff --git a/fs/afs/rxrpc.c b/fs/afs/rxrpc.c
index 1ecc67da6c1a4..e313dae01674f 100644
--- a/fs/afs/rxrpc.c
+++ b/fs/afs/rxrpc.c
@@ -37,7 +37,6 @@ int afs_open_socket(struct afs_net *net)
{
struct sockaddr_rxrpc srx;
struct socket *socket;
- unsigned int min_level;
int ret;

_enter("");
@@ -57,9 +56,8 @@ int afs_open_socket(struct afs_net *net)
srx.transport.sin6.sin6_family = AF_INET6;
srx.transport.sin6.sin6_port = htons(AFS_CM_PORT);

- min_level = RXRPC_SECURITY_ENCRYPT;
- ret = kernel_setsockopt(socket, SOL_RXRPC, RXRPC_MIN_SECURITY_LEVEL,
- (void *)&min_level, sizeof(min_level));
+ ret = rxrpc_sock_set_min_security_level(socket->sk,
+ RXRPC_SECURITY_ENCRYPT);
if (ret < 0)
goto error_2;

diff --git a/include/net/af_rxrpc.h b/include/net/af_rxrpc.h
index 04e97bab6f28b..8d7b469453bda 100644
--- a/include/net/af_rxrpc.h
+++ b/include/net/af_rxrpc.h
@@ -72,4 +72,6 @@ bool rxrpc_kernel_call_is_complete(struct rxrpc_call *);
void rxrpc_kernel_set_max_life(struct socket *, struct rxrpc_call *,
unsigned long);

+int rxrpc_sock_set_min_security_level(struct sock *sk, unsigned int val);
+
#endif /* _NET_RXRPC_H */
diff --git a/net/rxrpc/af_rxrpc.c b/net/rxrpc/af_rxrpc.c
index 15ee92d795815..394189b81849f 100644
--- a/net/rxrpc/af_rxrpc.c
+++ b/net/rxrpc/af_rxrpc.c
@@ -571,6 +571,19 @@ static int rxrpc_sendmsg(struct socket *sock, struct msghdr *m, size_t len)
return ret;
}

+int rxrpc_sock_set_min_security_level(struct sock *sk, unsigned int val)
+{
+ if (sk->sk_state != RXRPC_UNBOUND)
+ return -EISCONN;
+ if (val > RXRPC_SECURITY_MAX)
+ return -EINVAL;
+ lock_sock(sk);
+ rxrpc_sk(sk)->min_sec_level = val;
+ release_sock(sk);
+ return 0;
+}
+EXPORT_SYMBOL(rxrpc_sock_set_min_security_level);
+
/*
* set RxRPC socket options
*/
--
2.26.2