nuttx/net/local/local_fifo.c

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/****************************************************************************
* net/local/local_fifo.c
*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership. The
* ASF licenses this file to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance with the
* License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations
* under the License.
*
****************************************************************************/
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#if defined(CONFIG_NET) && defined(CONFIG_NET_LOCAL)
#include <sys/stat.h>
#include <sys/ioctl.h>
#include <inttypes.h>
#include <stdbool.h>
#include <stdio.h>
#include <unistd.h>
#include <fcntl.h>
#include <string.h>
#include <errno.h>
#include <assert.h>
#include <debug.h>
#include "local/local.h"
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
#define LOCAL_CS_SUFFIX "CS" /* Name of the client-to-server FIFO */
#define LOCAL_SC_SUFFIX "SC" /* Name of the server-to-client FIFO */
#define LOCAL_HD_SUFFIX "HD" /* Name of the half duplex datagram FIFO */
#define LOCAL_SUFFIX_LEN 2
#define LOCAL_FULLPATH_LEN (sizeof(CONFIG_NET_LOCAL_VFS_PATH) + \
UNIX_PATH_MAX + LOCAL_SUFFIX_LEN + 2 + 8)
/****************************************************************************
* Private Functions
****************************************************************************/
/****************************************************************************
* Name: local_format_name
*
* Description:
* Format the name of the half duplex FIFO.
*
****************************************************************************/
static void local_format_name(FAR const char *inpath, FAR char *outpath,
FAR const char *suffix, int32_t id)
{
if (strncmp(inpath, CONFIG_NET_LOCAL_VFS_PATH,
sizeof(CONFIG_NET_LOCAL_VFS_PATH) - 1) == 0)
{
inpath += sizeof(CONFIG_NET_LOCAL_VFS_PATH) - 1;
}
if (id < 0)
{
snprintf(outpath, LOCAL_FULLPATH_LEN - 1,
CONFIG_NET_LOCAL_VFS_PATH "/%s%s", inpath, suffix);
}
else
{
snprintf(outpath, LOCAL_FULLPATH_LEN - 1,
CONFIG_NET_LOCAL_VFS_PATH "/%s%s%" PRIx32,
inpath, suffix, id);
}
outpath[LOCAL_FULLPATH_LEN - 1] = '\0';
}
/****************************************************************************
* Name: local_cs_name
*
* Description:
* Create the name of the client-to-server FIFO.
*
****************************************************************************/
static void local_cs_name(FAR struct local_conn_s *conn, FAR char *path)
{
local_format_name(conn->lc_path, path,
LOCAL_CS_SUFFIX, conn->lc_instance_id);
}
/****************************************************************************
* Name: local_sc_name
*
* Description:
* Create the name of the server-to-client FIFO.
*
****************************************************************************/
static void local_sc_name(FAR struct local_conn_s *conn, FAR char *path)
{
local_format_name(conn->lc_path, path,
LOCAL_SC_SUFFIX, conn->lc_instance_id);
}
/****************************************************************************
* Name: local_hd_name
*
* Description:
* Create the name of the half duplex, datagram FIFO.
*
****************************************************************************/
#ifdef CONFIG_NET_LOCAL_DGRAM
static void local_hd_name(FAR const char *inpath, FAR char *outpath)
{
local_format_name(inpath, outpath, LOCAL_HD_SUFFIX, -1);
}
#endif /* CONFIG_NET_LOCAL_DGRAM */
/****************************************************************************
* Name: local_fifo_exists
*
* Description:
* Check if a FIFO exists.
*
****************************************************************************/
static bool local_fifo_exists(FAR const char *path)
{
struct stat buf;
int ret;
/* Create the client-to-server FIFO */
ret = nx_stat(path, &buf, 1);
if (ret < 0)
{
return false;
}
/* Return true if what we found is a FIFO. What if it is something else?
* In that case, we will return false and mkfifo() will fail.
*/
return (bool)S_ISFIFO(buf.st_mode);
}
/****************************************************************************
* Name: local_create_fifo
*
* Description:
* Create the one FIFO.
*
****************************************************************************/
static int local_create_fifo(FAR const char *path)
{
int ret;
/* Create the client-to-server FIFO if it does not already exist. */
if (!local_fifo_exists(path))
{
ret = nx_mkfifo(path, 0644, CONFIG_DEV_FIFO_SIZE);
if (ret < 0)
{
nerr("ERROR: Failed to create FIFO %s: %d\n", path, ret);
return ret;
}
}
/* The FIFO (or some character driver) exists at PATH or we successfully
* created the FIFO at that location.
*/
return OK;
}
/****************************************************************************
* Name: local_release_fifo
*
* Description:
* Release a reference from one of the FIFOs used in a connection.
*
****************************************************************************/
static int local_release_fifo(FAR const char *path)
{
int ret;
/* Unlink the client-to-server FIFO if it exists. */
if (local_fifo_exists(path))
{
/* Un-linking the FIFO removes the FIFO from the namespace. It will
* also mark the FIFO device "unlinked". When all of the open
* references to the FIFO device are closed, the resources consumed
* by the device instance will also be freed.
*/
ret = nx_unlink(path);
if (ret < 0)
{
nerr("ERROR: Failed to unlink FIFO %s: %d\n", path, ret);
return ret;
}
}
/* The FIFO does not exist or we successfully unlinked it. */
return OK;
}
/****************************************************************************
* Name: local_rx_open
*
* Description:
* Open a FIFO for read-only access.
*
****************************************************************************/
static int local_rx_open(FAR struct local_conn_s *conn, FAR const char *path,
bool nonblock)
{
int oflags = nonblock ? O_RDONLY | O_NONBLOCK : O_RDONLY;
int ret;
ret = file_open(&conn->lc_infile, path, oflags | O_CLOEXEC);
if (ret < 0)
{
nerr("ERROR: Failed on open %s for reading: %d\n",
path, ret);
/* Map the error code to something consistent with the return
* error codes from connect():
*
* If error is ENOENT, meaning that the FIFO does exist,
* return EFAULT meaning that the socket structure address is
* outside the user's address space.
*/
return ret == -ENOENT ? -EFAULT : ret;
}
return OK;
}
/****************************************************************************
* Name: local_tx_open
*
* Description:
* Open a FIFO for write-only access.
*
****************************************************************************/
static int local_tx_open(FAR struct local_conn_s *conn, FAR const char *path,
bool nonblock)
{
int ret;
ret = file_open(&conn->lc_outfile, path, O_WRONLY | O_NONBLOCK |
O_CLOEXEC);
if (ret < 0)
{
nerr("ERROR: Failed on open %s for writing: %d\n",
path, ret);
/* Map the error code to something consistent with the return
* error codes from connect():
*
* If error is ENOENT, meaning that the FIFO does exist,
* return EFAULT meaning that the socket structure address is
* outside the user's address space.
*/
return ret == -ENOENT ? -EFAULT : ret;
}
/* Clear O_NONBLOCK if it's meant to be blocking */
if (nonblock == false)
{
ret = file_fcntl(&conn->lc_outfile, F_SETFL, O_WRONLY);
if (ret < 0)
{
return ret;
}
}
return OK;
}
/****************************************************************************
* Name: local_set_policy
*
* Description:
* Set the FIFO buffer policy:
*
* 0=Free FIFO resources when the last reference is closed
* 1=Free FIFO resources when the buffer is empty.
*
****************************************************************************/
static int local_set_policy(FAR struct file *filep, unsigned long policy)
{
int ret;
/* Set the buffer policy */
ret = file_ioctl(filep, PIPEIOC_POLICY, policy);
if (ret < 0)
{
nerr("ERROR: Failed to set FIFO buffer policy: %d\n", ret);
}
return ret;
}
/****************************************************************************
* Name: local_set_pollinthreshold
*
* Description:
* Set the local pollin threshold:
*
****************************************************************************/
#ifdef CONFIG_NET_LOCAL_DGRAM
static int local_set_pollinthreshold(FAR struct file *filep,
unsigned long threshold)
{
int ret;
/* Set the buffer poll threshold */
ret = file_ioctl(filep, PIPEIOC_POLLINTHRD, threshold);
if (ret < 0)
{
nerr("ERROR: Failed to set FIFO pollin threshold: %lu\n",
threshold);
}
return ret;
}
#endif /* CONFIG_NET_LOCAL_DGRAM */
/****************************************************************************
* Name: local_set_polloutthreshold
*
* Description:
* Set the local pollout threshold:
*
****************************************************************************/
#ifdef CONFIG_NET_LOCAL_DGRAM
static int local_set_polloutthreshold(FAR struct file *filep,
unsigned long threshold)
{
int ret;
/* Set the buffer poll threshold */
ret = file_ioctl(filep, PIPEIOC_POLLOUTTHRD, threshold);
if (ret < 0)
{
nerr("ERROR: Failed to set FIFO pollout threshold: %lu\n",
threshold);
}
return ret;
}
#endif /* CONFIG_NET_LOCAL_DGRAM */
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: local_set_pollthreshold
*
* Description:
* Set the local pollin and pollout threshold:
*
****************************************************************************/
#ifdef CONFIG_NET_LOCAL_DGRAM
int local_set_pollthreshold(FAR struct local_conn_s *conn,
unsigned long threshold)
{
int ret;
/* Set the buffer poll threshold */
ret = local_set_pollinthreshold(&conn->lc_infile, threshold);
if (ret > 0)
{
ret = local_set_polloutthreshold(&conn->lc_outfile, threshold);
}
return ret;
}
#endif /* CONFIG_NET_LOCAL_DGRAM */
/****************************************************************************
* Name: local_create_fifos
*
* Description:
* Create the FIFO pair needed for a SOCK_STREAM connection.
*
****************************************************************************/
int local_create_fifos(FAR struct local_conn_s *conn)
{
char path[LOCAL_FULLPATH_LEN];
int ret;
/* Create the client-to-server FIFO if it does not already exist. */
local_cs_name(conn, path);
ret = local_create_fifo(path);
if (ret >= 0)
{
/* Create the server-to-client FIFO if it does not already exist. */
local_sc_name(conn, path);
ret = local_create_fifo(path);
}
return ret;
}
/****************************************************************************
* Name: local_create_halfduplex
*
* Description:
* Create the half-duplex FIFO needed for SOCK_DGRAM communication.
*
****************************************************************************/
#ifdef CONFIG_NET_LOCAL_DGRAM
int local_create_halfduplex(FAR struct local_conn_s *conn,
FAR const char *path)
{
char fullpath[LOCAL_FULLPATH_LEN];
/* Create the half duplex FIFO if it does not already exist. */
local_hd_name(path, fullpath);
return local_create_fifo(fullpath);
}
#endif /* CONFIG_NET_LOCAL_DGRAM */
/****************************************************************************
* Name: local_release_fifos
*
* Description:
* Release references to the FIFO pair used for a SOCK_STREAM connection.
*
****************************************************************************/
int local_release_fifos(FAR struct local_conn_s *conn)
{
char path[LOCAL_FULLPATH_LEN];
int ret1;
int ret2;
/* Destroy the client-to-server FIFO if it exists. */
local_sc_name(conn, path);
ret1 = local_release_fifo(path);
/* Destroy the server-to-client FIFO if it exists. */
local_cs_name(conn, path);
ret2 = local_release_fifo(path);
/* Return a failure if one occurred. */
return ret1 < 0 ? ret1 : ret2;
}
/****************************************************************************
* Name: local_release_halfduplex
*
* Description:
* Release a reference to the FIFO used for SOCK_DGRAM communication
*
****************************************************************************/
#ifdef CONFIG_NET_LOCAL_DGRAM
int local_release_halfduplex(FAR struct local_conn_s *conn)
{
#if 1
/* REVISIT: We need to think about this carefully. Unlike the connection-
* oriented Unix domain socket, we don't really know the best time to
* release the FIFO resource. It would be extremely inefficient to create
* and destroy the FIFO on each packet. But, on the other hand, failing
* to destroy the FIFO will leave the FIFO resources in place after the
* communications have completed.
*
2015-02-01 19:23:57 +01:00
* I am thinking that there should be something like a timer. The timer
* would be started at the completion of each transfer and cancelled at
* the beginning of each transfer. If the timer expires, then the FIFO
* would be destroyed.
*/
/* #warning Missing logic */
return OK;
#else
char path[LOCAL_FULLPATH_LEN];
/* Destroy the half duplex FIFO if it exists. */
local_hd_name(conn->lc_path, path);
return local_release_fifo(path);
#endif
}
#endif /* CONFIG_NET_LOCAL_DGRAM */
/****************************************************************************
* Name: local_open_client_rx
*
* Description:
* Open the client-side of the server-to-client FIFO.
*
****************************************************************************/
int local_open_client_rx(FAR struct local_conn_s *client, bool nonblock)
{
char path[LOCAL_FULLPATH_LEN];
int ret;
/* Get the server-to-client path name */
local_sc_name(client, path);
/* Then open the file for read-only access */
ret = local_rx_open(client, path, nonblock);
if (ret == OK)
{
/* Policy: Free FIFO resources when the last reference is closed */
ret = local_set_policy(&client->lc_infile, 0);
}
return ret;
}
/****************************************************************************
* Name: local_open_client_tx
*
* Description:
* Open the client-side of the client-to-server FIFO.
*
****************************************************************************/
int local_open_client_tx(FAR struct local_conn_s *client, bool nonblock)
{
char path[LOCAL_FULLPATH_LEN];
int ret;
/* Get the client-to-server path name */
local_cs_name(client, path);
/* Then open the file for write-only access */
ret = local_tx_open(client, path, nonblock);
if (ret == OK)
{
/* Policy: Free FIFO resources when the last reference is closed */
ret = local_set_policy(&client->lc_outfile, 0);
}
return ret;
}
/****************************************************************************
* Name: local_open_server_rx
*
* Description:
* Open the server-side of the client-to-server FIFO.
*
****************************************************************************/
int local_open_server_rx(FAR struct local_conn_s *server, bool nonblock)
{
char path[LOCAL_FULLPATH_LEN];
int ret;
/* Get the client-to-server path name */
local_cs_name(server, path);
/* Then open the file for write-only access */
ret = local_rx_open(server, path, nonblock);
if (ret == OK)
{
/* Policy: Free FIFO resources when the last reference is closed */
ret = local_set_policy(&server->lc_infile, 0);
}
return ret;
}
/****************************************************************************
* Name: local_open_server_tx
*
* Description:
* Only the server-side of the server-to-client FIFO.
*
****************************************************************************/
int local_open_server_tx(FAR struct local_conn_s *server, bool nonblock)
{
char path[LOCAL_FULLPATH_LEN];
int ret;
/* Get the server-to-client path name */
local_sc_name(server, path);
/* Then open the file for read-only access */
ret = local_tx_open(server, path, nonblock);
if (ret == OK)
{
/* Policy: Free FIFO resources when the last reference is closed */
ret = local_set_policy(&server->lc_outfile, 0);
}
return ret;
}
/****************************************************************************
* Name: local_open_receiver
*
* Description:
* Only the receiving side of the half duplex FIFO.
*
****************************************************************************/
#ifdef CONFIG_NET_LOCAL_DGRAM
int local_open_receiver(FAR struct local_conn_s *conn, bool nonblock)
{
char path[LOCAL_FULLPATH_LEN];
int ret;
/* Get the server-to-client path name */
local_hd_name(conn->lc_path, path);
/* Then open the file for read-only access */
ret = local_rx_open(conn, path, nonblock);
if (ret == OK)
{
/* Policy: Free FIFO resources when the buffer is empty. */
ret = local_set_policy(&conn->lc_infile, 1);
if (ret == 0)
{
/* Set POLLOUT threshold bigger than preamble len.
* This is to avoid non-blocking read failed with -EAGAIN when
* only preamble len is sent and read by reader.
*/
ret = local_set_polloutthreshold(&conn->lc_infile,
sizeof(uint16_t));
}
}
return ret;
}
#endif /* CONFIG_NET_LOCAL_DGRAM */
/****************************************************************************
* Name: local_open_sender
*
* Description:
* Only the sending side of the half duplex FIFO.
*
****************************************************************************/
#ifdef CONFIG_NET_LOCAL_DGRAM
int local_open_sender(FAR struct local_conn_s *conn, FAR const char *path,
bool nonblock)
{
char fullpath[LOCAL_FULLPATH_LEN];
int ret;
/* Get the server-to-client path name */
local_hd_name(path, fullpath);
/* Then open the file for read-only access */
ret = local_tx_open(conn, fullpath, nonblock);
if (ret == OK)
{
/* Policy: Free FIFO resources when the buffer is empty. */
ret = local_set_policy(&conn->lc_outfile, 1);
if (ret == 0)
{
/* Set POLLIN threshold bigger than preamble len.
* This is to avoid non-blocking read failed with -EAGAIN when
* only preamble len is sent and read by reader.
*/
ret = local_set_pollinthreshold(&conn->lc_outfile,
sizeof(uint16_t));
}
}
return ret;
}
#endif /* CONFIG_NET_LOCAL_DGRAM */
/****************************************************************************
* Name: local_set_nonblocking
*
* Description:
* Set the local conntion to nonblocking mode
*
****************************************************************************/
int local_set_nonblocking(FAR struct local_conn_s *conn)
{
int nonblock = 1;
int ret;
/* Set the conn to nonblocking mode */
ret = file_ioctl(&conn->lc_infile, FIONBIO, &nonblock);
ret |= file_ioctl(&conn->lc_outfile, FIONBIO, &nonblock);
if (ret < 0)
{
nerr("ERROR: Failed to set the conn to nonblocking mode: %d\n", ret);
}
return ret;
}
#endif /* CONFIG_NET && CONFIG_NET_LOCAL */