diff options
author | David Howells <dhowells@redhat.com> | 2016-08-30 22:42:14 +0300 |
---|---|---|
committer | David S. Miller <davem@davemloft.net> | 2016-09-02 02:43:27 +0300 |
commit | d001648ec7cf8b21ae9eec8b9ba4a18295adfb14 (patch) | |
tree | 830a6ec7dbc683675ba088750caeb5eafb4c8012 /net/rxrpc/input.c | |
parent | 95ac3994514015823634ef1f7116dce24f26aa97 (diff) | |
download | linux-d001648ec7cf8b21ae9eec8b9ba4a18295adfb14.tar.xz |
rxrpc: Don't expose skbs to in-kernel users [ver #2]
Don't expose skbs to in-kernel users, such as the AFS filesystem, but
instead provide a notification hook the indicates that a call needs
attention and another that indicates that there's a new call to be
collected.
This makes the following possibilities more achievable:
(1) Call refcounting can be made simpler if skbs don't hold refs to calls.
(2) skbs referring to non-data events will be able to be freed much sooner
rather than being queued for AFS to pick up as rxrpc_kernel_recv_data
will be able to consult the call state.
(3) We can shortcut the receive phase when a call is remotely aborted
because we don't have to go through all the packets to get to the one
cancelling the operation.
(4) It makes it easier to do encryption/decryption directly between AFS's
buffers and sk_buffs.
(5) Encryption/decryption can more easily be done in the AFS's thread
contexts - usually that of the userspace process that issued a syscall
- rather than in one of rxrpc's background threads on a workqueue.
(6) AFS will be able to wait synchronously on a call inside AF_RXRPC.
To make this work, the following interface function has been added:
int rxrpc_kernel_recv_data(
struct socket *sock, struct rxrpc_call *call,
void *buffer, size_t bufsize, size_t *_offset,
bool want_more, u32 *_abort_code);
This is the recvmsg equivalent. It allows the caller to find out about the
state of a specific call and to transfer received data into a buffer
piecemeal.
afs_extract_data() and rxrpc_kernel_recv_data() now do all the extraction
logic between them. They don't wait synchronously yet because the socket
lock needs to be dealt with.
Five interface functions have been removed:
rxrpc_kernel_is_data_last()
rxrpc_kernel_get_abort_code()
rxrpc_kernel_get_error_number()
rxrpc_kernel_free_skb()
rxrpc_kernel_data_consumed()
As a temporary hack, sk_buffs going to an in-kernel call are queued on the
rxrpc_call struct (->knlrecv_queue) rather than being handed over to the
in-kernel user. To process the queue internally, a temporary function,
temp_deliver_data() has been added. This will be replaced with common code
between the rxrpc_recvmsg() path and the kernel_rxrpc_recv_data() path in a
future patch.
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/rxrpc/input.c')
-rw-r--r-- | net/rxrpc/input.c | 10 |
1 files changed, 8 insertions, 2 deletions
diff --git a/net/rxrpc/input.c b/net/rxrpc/input.c index 86bea9ad6c3d..72f016cfaaf5 100644 --- a/net/rxrpc/input.c +++ b/net/rxrpc/input.c @@ -90,9 +90,15 @@ int rxrpc_queue_rcv_skb(struct rxrpc_call *call, struct sk_buff *skb, } /* allow interception by a kernel service */ - if (rx->interceptor) { - rx->interceptor(sk, call->user_call_ID, skb); + if (skb->mark == RXRPC_SKB_MARK_NEW_CALL && + rx->notify_new_call) { spin_unlock_bh(&sk->sk_receive_queue.lock); + skb_queue_tail(&call->knlrecv_queue, skb); + rx->notify_new_call(&rx->sk); + } else if (call->notify_rx) { + spin_unlock_bh(&sk->sk_receive_queue.lock); + skb_queue_tail(&call->knlrecv_queue, skb); + call->notify_rx(&rx->sk, call, call->user_call_ID); } else { _net("post skb %p", skb); __skb_queue_tail(&sk->sk_receive_queue, skb); |