Provide a getsockopt() call that can query what cmsg types are supported by
AF_RXRPC.
---
Documentation/networking/rxrpc.txt | 9 +++++++++
include/linux/rxrpc.h | 24 ++++++++++++++----------
net/rxrpc/af_rxrpc.c | 30 +++++++++++++++++++++++++++++-
3 files changed, 52 insertions(+), 11 deletions(-)
diff --git a/Documentation/networking/rxrpc.txt
b/Documentation/networking/rxrpc.txt
index 18078e630a63..bce8e10a2a8e 100644
--- a/Documentation/networking/rxrpc.txt
+++ b/Documentation/networking/rxrpc.txt
@@ -406,6 +406,10 @@ calls, to invoke certain actions and to report certain
conditions. These are:
future communication to that server and RXRPC_UPGRADE_SERVICE should no
longer be set.
+The symbol RXRPC__SUPPORTED is defined as one more than the highest control
+message type supported. At run time this can be queried by means of the
+RXRPC_SUPPORTED_CMSG socket option (see below).
+
==============
SOCKET OPTIONS
@@ -459,6 +463,11 @@ AF_RXRPC sockets support a few socket options at the
SOL_RXRPC level:
must point to an array of two unsigned short ints. The first is the
service ID to upgrade from and the second the service ID to upgrade to.
+ (*) RXRPC_SUPPORTED_CMSG
+
+ This is a read-only option that writes an int into the buffer indicating
+ the highest control message type supported.
+
========
SECURITY
diff --git a/include/linux/rxrpc.h b/include/linux/rxrpc.h
index 707910c6c6c5..bdd3175b9a48 100644
--- a/include/linux/rxrpc.h
+++ b/include/linux/rxrpc.h
@@ -38,6 +38,7 @@ struct sockaddr_rxrpc {
#define RXRPC_EXCLUSIVE_CONNECTION 3 /* Deprecated; use
RXRPC_EXCLUSIVE_CALL instead */
#define RXRPC_MIN_SECURITY_LEVEL 4 /* minimum security level */
#define RXRPC_UPGRADEABLE_SERVICE 5 /* Upgrade service[0] ->
service[1] */
+#define RXRPC_SUPPORTED_CMSG 6 /* Get highest supported
control message type */
/*
* RxRPC control messages
@@ -45,16 +46,19 @@ struct sockaddr_rxrpc {
* - terminal messages mean that a user call ID tag can be recycled
* - s/r/- indicate whether these are applicable to sendmsg() and/or recvmsg()
*/
-#define RXRPC_USER_CALL_ID 1 /* sr: user call ID specifier */
-#define RXRPC_ABORT 2 /* sr: abort request / notification
[terminal] */
-#define RXRPC_ACK 3 /* -r: [Service] RPC op final ACK
received [terminal] */
-#define RXRPC_NET_ERROR 5 /* -r: network error received
[terminal] */
-#define RXRPC_BUSY 6 /* -r: server busy received [terminal]
*/
-#define RXRPC_LOCAL_ERROR 7 /* -r: local error generated [terminal]
*/
-#define RXRPC_NEW_CALL 8 /* -r: [Service] new incoming call
notification */
-#define RXRPC_ACCEPT 9 /* s-: [Service] accept request */
-#define RXRPC_EXCLUSIVE_CALL 10 /* s-: Call should be on exclusive
connection */
-#define RXRPC_UPGRADE_SERVICE 11 /* s-: Request service upgrade for
client call */
+enum rxrpc_cmsg_type {
+ RXRPC_USER_CALL_ID = 1, /* sr: user call ID specifier */
+ RXRPC_ABORT = 2, /* sr: abort request / notification
[terminal] */
+ RXRPC_ACK = 3, /* -r: [Service] RPC op final ACK
received [terminal] */
+ RXRPC_NET_ERROR = 5, /* -r: network error received
[terminal] */
+ RXRPC_BUSY = 6, /* -r: server busy received [terminal]
*/
+ RXRPC_LOCAL_ERROR = 7, /* -r: local error generated [terminal]
*/
+ RXRPC_NEW_CALL = 8, /* -r: [Service] new incoming call
notification */
+ RXRPC_ACCEPT = 9, /* s-: [Service] accept request */
+ RXRPC_EXCLUSIVE_CALL = 10, /* s-: Call should be on exclusive
connection */
+ RXRPC_UPGRADE_SERVICE = 11, /* s-: Request service upgrade for
client call */
+ RXRPC__SUPPORTED
+};
/*
* RxRPC security levels
diff --git a/net/rxrpc/af_rxrpc.c b/net/rxrpc/af_rxrpc.c
index 0c4dc4a7832c..44a52b82bb5d 100644
--- a/net/rxrpc/af_rxrpc.c
+++ b/net/rxrpc/af_rxrpc.c
@@ -582,6 +582,34 @@ static int rxrpc_setsockopt(struct socket *sock, int
level, int optname,
}
/*
+ * Get socket options.
+ */
+static int rxrpc_getsockopt(struct socket *sock, int level, int optname,
+ char __user *optval, int __user *_optlen)
+{
+ int optlen;
+
+ if (level != SOL_RXRPC)
+ return -EOPNOTSUPP;
+
+ if (get_user(optlen, _optlen))
+ return -EFAULT;
+
+ switch (optname) {
+ case RXRPC_SUPPORTED_CMSG:
+ if (optlen < sizeof(int))
+ return -ETOOSMALL;
+ if (put_user(RXRPC__SUPPORTED - 1, (int __user *)optval) ||
+ put_user(sizeof(int), _optlen))
+ return -EFAULT;
+ return 0;
+
+ default:
+ return -EOPNOTSUPP;
+ }
+}
+
+/*
* permit an RxRPC socket to be polled
*/
static unsigned int rxrpc_poll(struct file *file, struct socket *sock,
@@ -784,7 +812,7 @@ static const struct proto_ops rxrpc_rpc_ops = {
.listen = rxrpc_listen,
.shutdown = rxrpc_shutdown,
.setsockopt = rxrpc_setsockopt,
- .getsockopt = sock_no_getsockopt,
+ .getsockopt = rxrpc_getsockopt,
.sendmsg = rxrpc_sendmsg,
.recvmsg = rxrpc_recvmsg,
.mmap = sock_no_mmap,
