linux/net/rxrpc/sendmsg.c

// SPDX-License-Identifier: GPL-2.0-or-later
/* AF_RXRPC sendmsg() implementation.
 *
 * Copyright (C) 2007, 2016 Red Hat, Inc. All Rights Reserved.
 * Written by David Howells ([email protected])
 */

#define pr_fmt(fmt) …

#include <linux/net.h>
#include <linux/gfp.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"

/*
 * Propose an abort to be made in the I/O thread.
 */
bool rxrpc_propose_abort(struct rxrpc_call *call, s32 abort_code, int error,
			 enum rxrpc_abort_reason why)
{ … }

/*
 * Wait for a call to become connected.  Interruption here doesn't cause the
 * call to be aborted.
 */
static int rxrpc_wait_to_be_connected(struct rxrpc_call *call, long *timeo)
{ … }

/*
 * Return true if there's sufficient Tx queue space.
 */
static bool rxrpc_check_tx_space(struct rxrpc_call *call, rxrpc_seq_t *_tx_win)
{ … }

/*
 * Wait for space to appear in the Tx queue or a signal to occur.
 */
static int rxrpc_wait_for_tx_window_intr(struct rxrpc_sock *rx,
					 struct rxrpc_call *call,
					 long *timeo)
{ … }

/*
 * Wait for space to appear in the Tx queue uninterruptibly, but with
 * a timeout of 2*RTT if no progress was made and a signal occurred.
 */
static int rxrpc_wait_for_tx_window_waitall(struct rxrpc_sock *rx,
					    struct rxrpc_call *call)
{ … }

/*
 * Wait for space to appear in the Tx queue uninterruptibly.
 */
static int rxrpc_wait_for_tx_window_nonintr(struct rxrpc_sock *rx,
					    struct rxrpc_call *call,
					    long *timeo)
{ … }

/*
 * wait for space to appear in the transmit/ACK window
 * - caller holds the socket locked
 */
static int rxrpc_wait_for_tx_window(struct rxrpc_sock *rx,
				    struct rxrpc_call *call,
				    long *timeo,
				    bool waitall)
{ … }

/*
 * Notify the owner of the call that the transmit phase is ended and the last
 * packet has been queued.
 */
static void rxrpc_notify_end_tx(struct rxrpc_sock *rx, struct rxrpc_call *call,
				rxrpc_notify_end_tx_t notify_end_tx)
{ … }

/*
 * Queue a DATA packet for transmission, set the resend timeout and send
 * the packet immediately.  Returns the error from rxrpc_send_data_packet()
 * in case the caller wants to do something with it.
 */
static void rxrpc_queue_packet(struct rxrpc_sock *rx, struct rxrpc_call *call,
			       struct rxrpc_txbuf *txb,
			       rxrpc_notify_end_tx_t notify_end_tx)
{ … }

/*
 * send data through a socket
 * - must be called in process context
 * - The caller holds the call user access mutex, but not the socket lock.
 */
static int rxrpc_send_data(struct rxrpc_sock *rx,
			   struct rxrpc_call *call,
			   struct msghdr *msg, size_t len,
			   rxrpc_notify_end_tx_t notify_end_tx,
			   bool *_dropped_lock)
{ … }

/*
 * extract control messages from the sendmsg() control buffer
 */
static int rxrpc_sendmsg_cmsg(struct msghdr *msg, struct rxrpc_send_params *p)
{ … }

/*
 * Create a new client call for sendmsg().
 * - Called with the socket lock held, which it must release.
 * - If it returns a call, the call's lock will need releasing by the caller.
 */
static struct rxrpc_call *
rxrpc_new_client_call_for_sendmsg(struct rxrpc_sock *rx, struct msghdr *msg,
				  struct rxrpc_send_params *p)
	__releases(&rx->sk.sk_lock.slock)
	__acquires(&call->user_mutex)
{ … }

/*
 * send a message forming part of a client call through an RxRPC socket
 * - caller holds the socket locked
 * - the socket may be either a client socket or a server socket
 */
int rxrpc_do_sendmsg(struct rxrpc_sock *rx, struct msghdr *msg, size_t len)
	__releases(&rx->sk.sk_lock.slock)
{ … }

/**
 * rxrpc_kernel_send_data - Allow a kernel service to send data on a call
 * @sock: The socket the call is on
 * @call: The call to send data through
 * @msg: The data to send
 * @len: The amount of data to send
 * @notify_end_tx: Notification that the last packet is queued.
 *
 * Allow a kernel service to send data on a call.  The call must be in an state
 * appropriate to sending data.  No control data should be supplied in @msg,
 * nor should an address be supplied.  MSG_MORE should be flagged if there's
 * more data to come, otherwise this data will end the transmission phase.
 */
int rxrpc_kernel_send_data(struct socket *sock, struct rxrpc_call *call,
			   struct msghdr *msg, size_t len,
			   rxrpc_notify_end_tx_t notify_end_tx)
{ … }
EXPORT_SYMBOL(…);

/**
 * rxrpc_kernel_abort_call - Allow a kernel service to abort a call
 * @sock: The socket the call is on
 * @call: The call to be aborted
 * @abort_code: The abort code to stick into the ABORT packet
 * @error: Local error value
 * @why: Indication as to why.
 *
 * Allow a kernel service to abort a call, if it's still in an abortable state
 * and return true if the call was aborted, false if it was already complete.
 */
bool rxrpc_kernel_abort_call(struct socket *sock, struct rxrpc_call *call,
			     u32 abort_code, int error, enum rxrpc_abort_reason why)
{ … }
EXPORT_SYMBOL(…);

/**
 * rxrpc_kernel_set_tx_length - Set the total Tx length on a call
 * @sock: The socket the call is on
 * @call: The call to be informed
 * @tx_total_len: The amount of data to be transmitted for this call
 *
 * Allow a kernel service to set the total transmit length on a call.  This
 * allows buffer-to-packet encrypt-and-copy to be performed.
 *
 * This function is primarily for use for setting the reply length since the
 * request length can be set when beginning the call.
 */
void rxrpc_kernel_set_tx_length(struct socket *sock, struct rxrpc_call *call,
				s64 tx_total_len)
{ … }
EXPORT_SYMBOL(…);