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author | David Howells <dhowells@redhat.com> | 2016-08-30 21:42:14 +0200 |
---|---|---|
committer | David S. Miller <davem@davemloft.net> | 2016-09-02 01:43:27 +0200 |
commit | d001648ec7cf8b21ae9eec8b9ba4a18295adfb14 (patch) | |
tree | 830a6ec7dbc683675ba088750caeb5eafb4c8012 /include/net | |
parent | net: pegasus: Remove deprecated create_singlethread_workqueue (diff) | |
download | linux-d001648ec7cf8b21ae9eec8b9ba4a18295adfb14.tar.xz linux-d001648ec7cf8b21ae9eec8b9ba4a18295adfb14.zip |
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 'include/net')
-rw-r--r-- | include/net/af_rxrpc.h | 35 |
1 files changed, 11 insertions, 24 deletions
diff --git a/include/net/af_rxrpc.h b/include/net/af_rxrpc.h index f8d8079dc058..b4b6a3664dda 100644 --- a/include/net/af_rxrpc.h +++ b/include/net/af_rxrpc.h @@ -12,7 +12,6 @@ #ifndef _NET_RXRPC_H #define _NET_RXRPC_H -#include <linux/skbuff.h> #include <linux/rxrpc.h> struct key; @@ -20,38 +19,26 @@ struct sock; struct socket; struct rxrpc_call; -/* - * the mark applied to socket buffers that may be intercepted - */ -enum rxrpc_skb_mark { - RXRPC_SKB_MARK_DATA, /* data message */ - RXRPC_SKB_MARK_FINAL_ACK, /* final ACK received message */ - RXRPC_SKB_MARK_BUSY, /* server busy message */ - RXRPC_SKB_MARK_REMOTE_ABORT, /* remote abort message */ - RXRPC_SKB_MARK_LOCAL_ABORT, /* local abort message */ - RXRPC_SKB_MARK_NET_ERROR, /* network error message */ - RXRPC_SKB_MARK_LOCAL_ERROR, /* local error message */ - RXRPC_SKB_MARK_NEW_CALL, /* local error message */ -}; +typedef void (*rxrpc_notify_rx_t)(struct sock *, struct rxrpc_call *, + unsigned long); +typedef void (*rxrpc_notify_new_call_t)(struct sock *); -typedef void (*rxrpc_interceptor_t)(struct sock *, unsigned long, - struct sk_buff *); -void rxrpc_kernel_intercept_rx_messages(struct socket *, rxrpc_interceptor_t); +void rxrpc_kernel_new_call_notification(struct socket *, + rxrpc_notify_new_call_t); struct rxrpc_call *rxrpc_kernel_begin_call(struct socket *, struct sockaddr_rxrpc *, struct key *, unsigned long, - gfp_t); + gfp_t, + rxrpc_notify_rx_t); int rxrpc_kernel_send_data(struct socket *, struct rxrpc_call *, struct msghdr *, size_t); -void rxrpc_kernel_data_consumed(struct rxrpc_call *, struct sk_buff *); +int rxrpc_kernel_recv_data(struct socket *, struct rxrpc_call *, + void *, size_t, size_t *, bool, u32 *); void rxrpc_kernel_abort_call(struct socket *, struct rxrpc_call *, u32); void rxrpc_kernel_end_call(struct socket *, struct rxrpc_call *); -bool rxrpc_kernel_is_data_last(struct sk_buff *); -u32 rxrpc_kernel_get_abort_code(struct sk_buff *); -int rxrpc_kernel_get_error_number(struct sk_buff *); -void rxrpc_kernel_free_skb(struct sk_buff *); -struct rxrpc_call *rxrpc_kernel_accept_call(struct socket *, unsigned long); +struct rxrpc_call *rxrpc_kernel_accept_call(struct socket *, unsigned long, + rxrpc_notify_rx_t); int rxrpc_kernel_reject_call(struct socket *); void rxrpc_kernel_get_peer(struct socket *, struct rxrpc_call *, struct sockaddr_rxrpc *); |