diff options
Diffstat (limited to 'Documentation/networking/rxrpc.txt')
| -rw-r--r-- | Documentation/networking/rxrpc.txt | 53 |
1 files changed, 51 insertions, 2 deletions
diff --git a/Documentation/networking/rxrpc.txt b/Documentation/networking/rxrpc.txt index 810620153a44..b5407163d53b 100644 --- a/Documentation/networking/rxrpc.txt +++ b/Documentation/networking/rxrpc.txt @@ -280,6 +280,18 @@ Interaction with the user of the RxRPC socket: nominated by a socket option. +Notes on sendmsg: + + (*) MSG_WAITALL can be set to tell sendmsg to ignore signals if the peer is + making progress at accepting packets within a reasonable time such that we + manage to queue up all the data for transmission. This requires the + client to accept at least one packet per 2*RTT time period. + + If this isn't set, sendmsg() will return immediately, either returning + EINTR/ERESTARTSYS if nothing was consumed or returning the amount of data + consumed. + + Notes on recvmsg: (*) If there's a sequence of data messages belonging to a particular call on @@ -782,7 +794,9 @@ The kernel interface functions are as follows: struct key *key, unsigned long user_call_ID, s64 tx_total_len, - gfp_t gfp); + gfp_t gfp, + rxrpc_notify_rx_t notify_rx, + bool upgrade); This allocates the infrastructure to make a new RxRPC call and assigns call and connection numbers. The call will be made on the UDP port that @@ -803,6 +817,13 @@ The kernel interface functions are as follows: allows the kernel to encrypt directly to the packet buffers, thereby saving a copy. The value may not be less than -1. + notify_rx is a pointer to a function to be called when events such as + incoming data packets or remote aborts happen. + + upgrade should be set to true if a client operation should request that + the server upgrade the service to a better one. The resultant service ID + is returned by rxrpc_kernel_recv_data(). + If this function is successful, an opaque reference to the RxRPC call is returned. The caller now holds a reference on this and it must be properly ended. @@ -850,7 +871,8 @@ The kernel interface functions are as follows: size_t size, size_t *_offset, bool want_more, - u32 *_abort) + u32 *_abort, + u16 *_service) This is used to receive data from either the reply part of a client call or the request part of a service call. buf and size specify how much @@ -873,6 +895,9 @@ The kernel interface functions are as follows: If a remote ABORT is detected, the abort code received will be stored in *_abort and ECONNABORTED will be returned. + The service ID that the call ended up with is returned into *_service. + This can be used to see if a call got a service upgrade. + (*) Abort a call. void rxrpc_kernel_abort_call(struct socket *sock, @@ -1020,6 +1045,30 @@ The kernel interface functions are as follows: It returns 0 if the call was requeued and an error otherwise. + (*) Get call RTT. + + u64 rxrpc_kernel_get_rtt(struct socket *sock, struct rxrpc_call *call); + + Get the RTT time to the peer in use by a call. The value returned is in + nanoseconds. + + (*) Check call still alive. + + u32 rxrpc_kernel_check_life(struct socket *sock, + struct rxrpc_call *call); + + This returns a number that is updated when ACKs are received from the peer + (notably including PING RESPONSE ACKs which we can elicit by sending PING + ACKs to see if the call still exists on the server). The caller should + compare the numbers of two calls to see if the call is still alive after + waiting for a suitable interval. + + This allows the caller to work out if the server is still contactable and + if the call is still alive on the server whilst waiting for the server to + process a client operation. + + This function may transmit a PING ACK. + ======================= CONFIGURABLE PARAMETERS |