incubator-nuttx/net/route/net_fileroute.c

850 lines
21 KiB
C

/****************************************************************************
* net/route/net_fileroute.c
*
* Copyright (C) 2017, 2020 Gregory Nutt. All rights reserved.
* Author: Gregory Nutt <gnutt@nuttx.org>
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
* 3. Neither the name NuttX nor the names of its contributors may be
* used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*
****************************************************************************/
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#include <sys/stat.h>
#include <unistd.h>
#include <fcntl.h>
#include <errno.h>
#include <assert.h>
#include <debug.h>
#include <nuttx/semaphore.h>
#include <nuttx/fs/fs.h>
#include "route/fileroute.h"
#include "route/route.h"
#if defined(CONFIG_ROUTE_IPv4_FILEROUTE) || defined(CONFIG_ROUTE_IPv6_FILEROUTE)
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
/* Special "impossible" PID value used to indicate that there is no holder
* of the lock.
*/
#define NO_HOLDER ((pid_t)-1)
/****************************************************************************
* Private Data
****************************************************************************/
#ifdef CONFIG_ROUTE_IPv4_FILEROUTE
/* Semaphore used to lock a routing table for exclusive write-only access */
static sem_t g_ipv4_exclsem;
static pid_t g_ipv4_holder = NO_HOLDER;
static int g_ipv4_count;
#endif
#ifdef CONFIG_ROUTE_IPv6_FILEROUTE
/* Semaphore used to lock a routing table for exclusive write-only access */
static sem_t g_ipv6_exclsem;
static pid_t g_ipv6_holder = NO_HOLDER;
static int g_ipv6_count;
#endif
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: net_openroute_detached
*
* Description:
* Open and detach the routing table.
*
* Input Parameters:
* pathname - The full path to the routing table entry
* oflags - Open flags
* filep - Location in which to return the detached file instance.
*
* Returned Value:
* A non-negative file descriptor is returned on success. A negated errno
* value is returned on any failure.
*
****************************************************************************/
int net_openroute_detached(FAR const char *pathname, int oflags,
FAR struct file *filep)
{
int ret;
/* Open the file for read/write access. */
ret = file_open(filep, pathname, oflags, 0644);
if (ret < 0)
{
nerr("ERROR: Failed to open %s: %d\n", pathname, ret);
return ret;
}
return OK;
}
/****************************************************************************
* Name: net_routesize
*
* Description:
* Return the size of a routing table in terms of the number of entries in
* the routing table.
*
* Input Parameters:
* path - The path to the routing table
* entrysize - The size of one entry in the routing table
*
* Returned Value:
* A non-negative count of the number of entries in the routing table is
* returned on success; a negated errno value is returned on and failure.
*
****************************************************************************/
int net_routesize(FAR const char *path, size_t entrysize)
{
struct stat buf;
int ret;
/* Get information about the file */
ret = stat(path, &buf);
if (ret < 0)
{
int errcode;
/* stat() failed, but is that because the routing table has not been
* created yet?
*/
errcode = get_errno();
if (errcode == ENOENT)
{
/* The routing table file has not been created. Return size zero. */
return 0;
}
/* Some other error */
return -errcode;
}
/* The directory entry at this path must be a regular file */
if (S_ISREG(buf.st_mode))
{
unsigned int nentries = buf.st_size / entrysize;
#ifdef CONFIG_DEBUG_NET_WARN
if (nentries * entrysize != buf.st_size)
{
nwarn("WARNING: Size of routing table is not an even multiple of "
"entries\n");
nwarn(" %lu != %lu / %lu\n",
(unsigned long)nentries,
(unsigned long)buf.st_size,
(unsigned long)entrysize);
}
#endif
return nentries;
}
/* It is probably a directory (should check for sure) */
return -EISDIR;
}
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: net_init_fileroute
*
* Description:
* Initialize the in-memory, RAM routing table
*
* Input Parameters:
* None
*
* Returned Value:
* None
*
* Assumptions:
* Called early in initialization so that no special protection is needed.
*
****************************************************************************/
void net_init_fileroute(void)
{
/* Initialize semaphores */
#ifdef CONFIG_ROUTE_IPv4_FILEROUTE
nxsem_init(&g_ipv4_exclsem, 0, 1);
#endif
#ifdef CONFIG_ROUTE_IPv6_FILEROUTE
nxsem_init(&g_ipv6_exclsem, 0, 1);
#endif
}
/****************************************************************************
* Name: net_openroute_ipv4/net_openroute_ipv6
*
* Description:
* Open the IPv4/IPv6 routing table with the specified access privileges.
*
* Input Parameters:
* oflags - Open flags
* filep - Location in which to return the detached file instance.
*
* Returned Value:
* A non-negative file descriptor is returned on success. A negated errno
* value is returned on any failure.
*
****************************************************************************/
#ifdef CONFIG_ROUTE_IPv4_FILEROUTE
int net_openroute_ipv4(int oflags, FAR struct file *filep)
{
int ret;
/* Lock the route.. we don't want to open it while it is subject to
* modification.
*/
ret = net_lockroute_ipv4();
if (ret < 0)
{
nerr("ERROR: net_lockroute_ipv4() failed: %d\n", ret);
}
else
{
/* Open the file for read/write access. */
ret = net_openroute_detached(IPv4_ROUTE_PATH, oflags, filep);
if (ret < 0)
{
nerr("ERROR: net_openroute_detached() failed: %d\n", ret);
}
}
net_unlockroute_ipv4();
return ret;
}
#endif
#ifdef CONFIG_ROUTE_IPv6_FILEROUTE
int net_openroute_ipv6(int oflags, FAR struct file *filep)
{
int ret;
/* Lock the route.. we don't want to open it while it is subject to
* modification.
*/
ret = net_lockroute_ipv6();
if (ret < 0)
{
nerr("ERROR: net_lockroute_ipv6() failed: %d\n", ret);
}
else
{
/* Open the file for read/write access. */
ret = net_openroute_detached(IPv6_ROUTE_PATH, oflags, filep);
if (ret < 0)
{
nerr("ERROR: net_openroute_detached() failed: %d\n", ret);
}
}
net_unlockroute_ipv6();
return ret;
}
#endif
/****************************************************************************
* Name: net_readroute_ipv4/net_readroute_ipv6
*
* Description:
* Read one route entry from the IPv4/IPv6 routing table.
*
* Input Parameters:
* filep - Detached file instance obtained by net_openroute_ipv{4|6}[_rdonly]
* route - Location to return the next route read from the file
*
* Returned Value:
* The number of bytes read on success. The special return valud of zero
* indiates that the endof of file was encountered (and nothing was read).
* A negated errno value is returned on any failure.
*
****************************************************************************/
#ifdef CONFIG_ROUTE_IPv4_FILEROUTE
ssize_t net_readroute_ipv4(FAR struct file *filep,
FAR struct net_route_ipv4_s *route)
{
FAR uint8_t *dest;
ssize_t ntotal;
ssize_t ret;
/* Lock the route.. we don't want to read from it while it is subject to
* modification.
*/
ret = (ssize_t)net_lockroute_ipv4();
if (ret < 0)
{
nerr("ERROR: net_lockroute_ipv4() failed: %d\n", ret);
return ret;
}
/* Read one record from the current position in the routing table */
dest = (FAR uint8_t *)route;
ntotal = 0;
do
{
size_t nbytes = sizeof(struct net_route_ipv4_s) - ntotal;
ssize_t nread;
nread = file_read(filep, dest, nbytes);
if (nread <= 0)
{
/* Read error or end of file */
ntotal = nread;
break;
}
ntotal += nread;
dest += nread;
}
while (ntotal < sizeof(struct net_route_ipv4_s));
net_unlockroute_ipv4();
return ntotal;
}
#endif
#ifdef CONFIG_ROUTE_IPv6_FILEROUTE
ssize_t net_readroute_ipv6(FAR struct file *filep,
FAR struct net_route_ipv6_s *route)
{
FAR uint8_t *dest;
ssize_t ntotal;
ssize_t ret;
/* Lock the route.. we don't want to read from it while it is subject to
* modification.
*/
ret = (ssize_t)net_lockroute_ipv6();
if (ret < 0)
{
nerr("ERROR: net_lockroute_ipv6() failed: %d\n", ret);
return ret;
}
/* Read one record from the current position in the routing table */
dest = (FAR uint8_t *)route;
ntotal = 0;
do
{
size_t nbytes = sizeof(struct net_route_ipv6_s) - ntotal;
ssize_t nread;
nread = file_read(filep, dest, nbytes);
if (nread <= 0)
{
/* Read error or end of file */
ret = nread;
break;
}
ntotal += nread;
dest += nread;
}
while (ntotal < sizeof(struct net_route_ipv6_s));
net_unlockroute_ipv6();
return ntotal;
}
#endif
/****************************************************************************
* Name: net_writeroute_ipv4/net_writeroute_ipv6
*
* Description:
* Write one route entry to the IPv4/IPv6 routing table.
*
* Input Parameters:
* filep - Detached file instance obtained by net_openroute_ipv{4|6}[_rdonly]
* route - Location to return the next route read from the file
*
* Returned Value:
* The number of bytes written on success. A negated errno value is
* returned on any failure.
*
****************************************************************************/
#ifdef CONFIG_ROUTE_IPv4_FILEROUTE
ssize_t net_writeroute_ipv4(FAR struct file *filep,
FAR const struct net_route_ipv4_s *route)
{
FAR const uint8_t *src;
ssize_t ntotal;
ssize_t ret;
/* Lock the route.. we don't want to write to it while it is subject to
* modification.
*/
ret = (ssize_t)net_lockroute_ipv4();
if (ret < 0)
{
nerr("ERROR: net_lockroute_ipv4() failed: %d\n", ret);
return ret;
}
/* Write one record at the current position in the routing table */
src = (FAR const uint8_t *)route;
ntotal = 0;
do
{
size_t nbytes = sizeof(struct net_route_ipv4_s) - ntotal;
ssize_t nwritten;
nwritten = file_write(filep, src, nbytes);
if (nwritten <= 0)
{
/* Write error (zero is not a valid return value for write) */
ret = nwritten;
break;
}
ntotal += nwritten;
src += nwritten;
}
while (ntotal < sizeof(struct net_route_ipv4_s));
net_unlockroute_ipv4();
return ntotal;
}
#endif
#ifdef CONFIG_ROUTE_IPv6_FILEROUTE
ssize_t net_writeroute_ipv6(FAR struct file *filep,
FAR const struct net_route_ipv6_s *route)
{
FAR const uint8_t *src;
ssize_t ntotal;
ssize_t ret;
/* Lock the route.. we don't want to write to it while it is subject to
* modification.
*/
ret = (ssize_t)net_lockroute_ipv6();
if (ret < 0)
{
nerr("ERROR: net_lockroute_ipv6() failed: %d\n", ret);
return ret;
}
/* Write one record at the current position in the routing table */
src = (FAR const uint8_t *)route;
ntotal = 0;
do
{
size_t nbytes = sizeof(struct net_route_ipv6_s) - ntotal;
ssize_t nwritten;
nwritten = file_write(filep, src, nbytes);
if (nwritten <= 0)
{
/* Write error (zero is not a valid return value for write) */
ntotal = nwritten;
break;
}
ntotal += nwritten;
src += nwritten;
}
while (ntotal < sizeof(struct net_route_ipv6_s));
net_unlockroute_ipv6();
return ret;
}
#endif
/****************************************************************************
* Name: net_seekroute_ipv4/net_seekroute_ipv6
*
* Description:
* Seek to a specific entry entry to the IPv4/IPv6 routing table.
*
* Input Parameters:
* filep - Detached file instance obtained by net_openroute_ipv{4|6}[_rdonly]
* index - The index of the routing table entry to seek to.
*
* Returned Value:
* Zero (OK) is returned on success; a negated errno value is returned on
* failure.
*
****************************************************************************/
#ifdef CONFIG_ROUTE_IPv4_FILEROUTE
off_t net_seekroute_ipv4(FAR struct file *filep, unsigned int index)
{
off_t offset;
off_t ret;
/* Convert the index to a file offset */
offset = (off_t)index * sizeof(struct net_route_ipv4_s);
/* Then seek to that position */
ret = file_seek(filep, offset, SEEK_SET);
if (ret < 0)
{
nerr("ERROR: file_seek() failed: %ld\n", (long)ret);
return (int)ret;
}
return OK;
}
#endif
#ifdef CONFIG_ROUTE_IPv6_FILEROUTE
off_t net_seekroute_ipv6(FAR struct file *filep, unsigned int index)
{
off_t offset;
off_t ret;
/* Convert the index to a file offset */
offset = (off_t)index * sizeof(struct net_route_ipv6_s);
/* Then seek to that position */
ret = file_seek(filep, offset, SEEK_SET);
if (ret < 0)
{
nerr("ERROR: file_seek() failed: %ld\n", (long)ret);
return (int)ret;
}
return OK;
}
#endif
/****************************************************************************
* Name: net_routesize_ipv4/net_routesize_ipv6
*
* Description:
* Return the size of a routing table in terms of the number of entries in
* the routing table.
*
* Input Parameters:
* None
*
* Returned Value:
* A non-negative count of the number of entries in the routing table is
* returned on success; a negated errno value is returned on and failure.
*
* Assumptions:
* The size of the routing table may change after this size is returned
* unless the routing table is locked to prevent any modification to the
* routing table.
*
****************************************************************************/
#ifdef CONFIG_ROUTE_IPv4_FILEROUTE
int net_routesize_ipv4(void)
{
return net_routesize(IPv4_ROUTE_PATH, sizeof(struct net_route_ipv4_s));
}
#endif
#ifdef CONFIG_ROUTE_IPv6_FILEROUTE
int net_routesize_ipv6(void)
{
return net_routesize(IPv6_ROUTE_PATH, sizeof(struct net_route_ipv6_s));
}
#endif
/****************************************************************************
* Name: net_lockroute_ipv4/net_lockroute_ipv6
*
* Description:
* Lock access to the routing table. Necessary when a routing table is
* being reorganized due to deletion of a route.
*
* Input Parameters:
* None
*
* Returned Value:
* Zero (OK) is returned on success; a negated errno value is returned on
* any failure.
*
****************************************************************************/
#ifdef CONFIG_ROUTE_IPv4_FILEROUTE
int net_lockroute_ipv4(void)
{
pid_t me = getpid();
int ret;
/* Are we already the holder of the lock? */
if (g_ipv4_holder == me)
{
/* Yes.. just increment the count of locks held */
g_ipv4_count++;
ret = OK;
}
else
{
/* No.. wait to get the lock */
ret = nxsem_wait(&g_ipv4_exclsem);
if (ret < 0)
{
nerr("ERROR: nxsem_wait() failed: %d\n", ret);
}
else
{
DEBUGASSERT(g_ipv4_holder == NO_HOLDER && g_ipv4_count == 0);
/* We are now the holder with one count */
g_ipv4_holder = me;
g_ipv4_count = 1;
}
}
return ret;
}
#endif
#ifdef CONFIG_ROUTE_IPv6_FILEROUTE
int net_lockroute_ipv6(void)
{
pid_t me = getpid();
int ret;
/* Are we already the holder of the lock? */
if (g_ipv6_holder == me)
{
/* Yes.. just increment the count of locks held */
g_ipv6_count++;
ret = OK;
}
else
{
/* No.. wait to get the lock */
ret = nxsem_wait(&g_ipv6_exclsem);
if (ret < 0)
{
nerr("ERROR: nxsem_wait() failed: %d\n", ret);
}
else
{
DEBUGASSERT(g_ipv6_holder == NO_HOLDER && g_ipv6_count == 0);
/* We are now the holder with one count */
g_ipv6_holder = me;
g_ipv6_count = 1;
}
}
return ret;
}
#endif
/****************************************************************************
* Name: net_unlockroute_ipv4/net_unlockroute_ipv6
*
* Description:
* Release the read lock.
*
* Input Parameters:
* None
*
* Returned Value:
* Zero (OK) is returned on success; a negated errno value is returned on
* any failure.
*
****************************************************************************/
#ifdef CONFIG_ROUTE_IPv4_FILEROUTE
int net_unlockroute_ipv4(void)
{
pid_t me = getpid();
int ret;
/* If would be an error if we are called with on a thread that does not
* hold the lock.
*/
DEBUGASSERT(me == g_ipv4_holder && g_ipv4_count > 0);
/* Release the count on the lock. If this is the last count, then release
* the lock.
*/
if (g_ipv4_count > 1)
{
/* Not the last count... just decrement the count and return success */
g_ipv4_count--;
ret = OK;
}
else
{
/* This is the last count. Release the lock */
g_ipv4_holder = NO_HOLDER;
g_ipv4_count = 0;
ret = nxsem_post(&g_ipv4_exclsem);
if (ret < 0)
{
nerr("ERROR: nxsem_post() failed: %d\n", ret);
}
}
return ret;
}
#endif
#ifdef CONFIG_ROUTE_IPv6_FILEROUTE
int net_unlockroute_ipv6(void)
{
pid_t me = getpid();
int ret;
/* If would be an error if we are called with on a thread that does not
* hold the lock.
*/
DEBUGASSERT(me == g_ipv6_holder && g_ipv6_count > 0);
/* Release the count on the lock. If this is the last count, then release
* the lock.
*/
if (g_ipv6_count > 1)
{
/* Not the last count... just decrement the count and return success */
g_ipv6_count--;
ret = OK;
}
else
{
/* This is the last count. Release the lock */
g_ipv6_holder = NO_HOLDER;
g_ipv6_count = 0;
ret = nxsem_post(&g_ipv6_exclsem);
if (ret < 0)
{
nerr("ERROR: nxsem_post() failed: %d\n", ret);
}
}
return ret;
}
#endif
/****************************************************************************
* Name: net_closeroute_ipv4/net_closeroute_ipv6
*
* Description:
* Close the IPv4/IPv6 routing table.
*
* Input Parameters:
* filep - Detached file instance obtained by net_openroute_ipv{4|6}[_rdonly]
*
* Returned Value:
* Zero (OK) is returned on success. A negated errno value is returned on
* any failure.
*
****************************************************************************/
#ifdef CONFIG_ROUTE_IPv4_FILEROUTE
int net_closeroute_ipv4(FAR struct file *filep)
{
return file_close(filep);
}
#endif
#ifdef CONFIG_ROUTE_IPv6_FILEROUTE
int net_closeroute_ipv6(FAR struct file *filep)
{
return file_close(filep);
}
#endif
#endif /* CONFIG_ROUTE_IPv4_FILEROUTE || CONFIG_ROUTE_IPv6_FILEROUTE */