linux/net/rxrpc/recvmsg.c

// SPDX-License-Identifier: GPL-2.0-or-later
/* RxRPC recvmsg() implementation
 *
 * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
 * Written by David Howells ([email protected])
 */

#define pr_fmt(fmt) …

#include <linux/net.h>
#include <linux/skbuff.h>
#include <linux/export.h>
#include <linux/sched/signal.h>

#include <net/sock.h>
#include <net/af_rxrpc.h>
#include "ar-internal.h"

/*
 * Post a call for attention by the socket or kernel service.  Further
 * notifications are suppressed by putting recvmsg_link on a dummy queue.
 */
void rxrpc_notify_socket(struct rxrpc_call *call)
{ … }

/*
 * Pass a call terminating message to userspace.
 */
static int rxrpc_recvmsg_term(struct rxrpc_call *call, struct msghdr *msg)
{ … }

/*
 * Discard a packet we've used up and advance the Rx window by one.
 */
static void rxrpc_rotate_rx_window(struct rxrpc_call *call)
{ … }

/*
 * Decrypt and verify a DATA packet.
 */
static int rxrpc_verify_data(struct rxrpc_call *call, struct sk_buff *skb)
{ … }

/*
 * Deliver messages to a call.  This keeps processing packets until the buffer
 * is filled and we find either more DATA (returns 0) or the end of the DATA
 * (returns 1).  If more packets are required, it returns -EAGAIN and if the
 * call has failed it returns -EIO.
 */
static int rxrpc_recvmsg_data(struct socket *sock, struct rxrpc_call *call,
			      struct msghdr *msg, struct iov_iter *iter,
			      size_t len, int flags, size_t *_offset)
{ … }

/*
 * Receive a message from an RxRPC socket
 * - we need to be careful about two or more threads calling recvmsg
 *   simultaneously
 */
int rxrpc_recvmsg(struct socket *sock, struct msghdr *msg, size_t len,
		  int flags)
{ … }

/**
 * rxrpc_kernel_recv_data - Allow a kernel service to receive data/info
 * @sock: The socket that the call exists on
 * @call: The call to send data through
 * @iter: The buffer to receive into
 * @_len: The amount of data we want to receive (decreased on return)
 * @want_more: True if more data is expected to be read
 * @_abort: Where the abort code is stored if -ECONNABORTED is returned
 * @_service: Where to store the actual service ID (may be upgraded)
 *
 * Allow a kernel service to receive data and pick up information about the
 * state of a call.  Returns 0 if got what was asked for and there's more
 * available, 1 if we got what was asked for and we're at the end of the data
 * and -EAGAIN if we need more data.
 *
 * Note that we may return -EAGAIN to drain empty packets at the end of the
 * data, even if we've already copied over the requested data.
 *
 * *_abort should also be initialised to 0.
 */
int rxrpc_kernel_recv_data(struct socket *sock, struct rxrpc_call *call,
			   struct iov_iter *iter, size_t *_len,
			   bool want_more, u32 *_abort, u16 *_service)
{ … }
EXPORT_SYMBOL(…);