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nuttx/fs/procfs/fs_procfs.c

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/****************************************************************************
* fs/procfs/fs_procfs.c
*
* Copyright (C) 2013-2016 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/types.h>
#include <sys/statfs.h>
#include <sys/stat.h>
#include <stdint.h>
#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <fcntl.h>
#include <assert.h>
#include <errno.h>
#include <debug.h>
#include <nuttx/irq.h>
#include <nuttx/arch.h>
#include <nuttx/sched.h>
#include <nuttx/kmalloc.h>
#include <nuttx/fs/fs.h>
#include <nuttx/fs/procfs.h>
#include <nuttx/fs/dirent.h>
#include <nuttx/regex.h>
#if !defined(CONFIG_DISABLE_MOUNTPOINT) && defined(CONFIG_FS_PROCFS)
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
#define PROCFS_NATTRS 2
/****************************************************************************
* External Definitons
****************************************************************************/
extern const struct procfs_operations proc_operations;
extern const struct procfs_operations cpuload_operations;
extern const struct procfs_operations kmm_operations;
extern const struct procfs_operations module_operations;
extern const struct procfs_operations uptime_operations;
/* This is not good. These are implemented in other sub-systems. Having to
* deal with them here is not a good coupling. What is really needed is a
* run-time procfs registration system vs. a build time, fixed procfs
* configuration.
*/
extern const struct procfs_operations net_procfsoperations;
extern const struct procfs_operations mtd_procfsoperations;
extern const struct procfs_operations part_procfsoperations;
extern const struct procfs_operations smartfs_procfsoperations;
/* And even worse, this one is specific to the STM32. The solution to
* this nasty couple would be to replace this hard-coded, ROM-able
* operations table with a RAM-base registration table.
*/
#if defined(CONFIG_STM32_CCM_PROCFS) && !defined(CONFIG_FS_PROCFS_EXCLUDE_CCM)
extern const struct procfs_operations ccm_procfsoperations;
#endif
/****************************************************************************
* Private Types
****************************************************************************/
/* Table of all known / pre-registered procfs handlers / participants. */
#ifdef CONFIG_FS_PROCFS_REGISTER
static const struct procfs_entry_s g_base_entries[] =
#else
static const struct procfs_entry_s g_procfs_entries[] =
#endif
{
#ifndef CONFIG_FS_PROCFS_EXCLUDE_PROCESS
{ "[0-9]*/**", &proc_operations },
{ "[0-9]*", &proc_operations },
#endif
#if defined(CONFIG_SCHED_CPULOAD) && !defined(CONFIG_FS_PROCFS_EXCLUDE_CPULOAD)
{ "cpuload", &cpuload_operations },
#endif
#if defined(CONFIG_MM_KERNEL_HEAP) && !defined(CONFIG_FS_PROCFS_EXCLUDE_KMM)
{ "kmm", &kmm_operations },
#endif
#if defined(CONFIG_MODULE) && !defined(CONFIG_FS_PROCFS_EXCLUDE_MODULE)
{ "modules", &module_operations },
#endif
#if defined(CONFIG_FS_SMARTFS) && !defined(CONFIG_FS_PROCFS_EXCLUDE_SMARTFS)
//{ "fs/smartfs", &smartfs_procfsoperations },
{ "fs/smartfs**", &smartfs_procfsoperations },
#endif
#if defined(CONFIG_NET) && !defined(CONFIG_FS_PROCFS_EXCLUDE_NET)
{ "net", &net_procfsoperations },
{ "net/**", &net_procfsoperations },
#endif
#if defined(CONFIG_MTD) && !defined(CONFIG_FS_PROCFS_EXCLUDE_MTD)
{ "mtd", &mtd_procfsoperations },
#endif
#if defined(CONFIG_MTD_PARTITION) && !defined(CONFIG_FS_PROCFS_EXCLUDE_PARTITIONS)
{ "partitions", &part_procfsoperations },
#endif
#if !defined(CONFIG_FS_PROCFS_EXCLUDE_UPTIME)
{ "uptime", &uptime_operations },
#endif
};
#ifdef CONFIG_FS_PROCFS_REGISTER
static const uint8_t g_base_entrycount = sizeof(g_base_entries) /
sizeof(struct procfs_entry_s);
static FAR struct procfs_entry_s *g_procfs_entries;
static uint8_t g_procfs_entrycount;
#else
static const uint8_t g_procfs_entrycount = sizeof(g_procfs_entries) /
sizeof(struct procfs_entry_s);
#endif
/****************************************************************************
* Private Function Prototypes
****************************************************************************/
/* Helpers */
static void procfs_enum(FAR struct tcb_s *tcb, FAR void *arg);
/* File system methods */
static int procfs_open(FAR struct file *filep, FAR const char *relpath,
int oflags, mode_t mode);
static int procfs_close(FAR struct file *filep);
static ssize_t procfs_read(FAR struct file *filep, FAR char *buffer,
size_t buflen);
static ssize_t procfs_write(FAR struct file *filep, FAR const char *buffer,
size_t buflen);
static int procfs_ioctl(FAR struct file *filep, int cmd,
unsigned long arg);
static int procfs_dup(FAR const struct file *oldp,
FAR struct file *newp);
static int procfs_opendir(FAR struct inode *mountpt, const char *relpath,
FAR struct fs_dirent_s *dir);
static int procfs_closedir(FAR struct inode *mountpt,
FAR struct fs_dirent_s *dir);
static int procfs_readdir(FAR struct inode *mountpt,
FAR struct fs_dirent_s *dir);
static int procfs_rewinddir(FAR struct inode *mountpt,
FAR struct fs_dirent_s *dir);
static int procfs_bind(FAR struct inode *blkdriver,
FAR const void *data, FAR void **handle);
static int procfs_unbind(FAR void *handle, FAR struct inode **blkdriver,
unsigned int flags);
static int procfs_statfs(FAR struct inode *mountpt,
FAR struct statfs *buf);
static int procfs_stat(FAR struct inode *mountpt,
FAR const char *relpath, FAR struct stat *buf);
/* Initialization */
#ifdef CONFIG_FS_PROCFS_REGISTER
int procfs_initialize(void);
#else
# define procfs_initialize()
#endif
/****************************************************************************
* Private Data
****************************************************************************/
/****************************************************************************
* Public Data
****************************************************************************/
/* See fs_mount.c -- this structure is explicitly externed there.
* We use the old-fashioned kind of initializers so that this will compile
* with any compiler.
*/
const struct mountpt_operations procfs_operations =
{
procfs_open, /* open */
procfs_close, /* close */
procfs_read, /* read */
procfs_write, /* write */
NULL, /* seek */
procfs_ioctl, /* ioctl */
NULL, /* sync */
procfs_dup, /* dup */
procfs_opendir, /* opendir */
procfs_closedir, /* closedir */
procfs_readdir, /* readdir */
procfs_rewinddir, /* rewinddir */
procfs_bind, /* bind */
procfs_unbind, /* unbind */
procfs_statfs, /* statfs */
NULL, /* unlink */
NULL, /* mkdir */
NULL, /* rmdir */
NULL, /* rename */
procfs_stat /* stat */
};
/* Level 0 contains the directory of active tasks in addition to other
* statically registered entries with custom handlers. This strcture
* contains a snapshot of the active tasks when the directory is first
* opened.
*/
struct procfs_level0_s
{
struct procfs_dir_priv_s base; /* Base struct for ProcFS dir */
/* Our private data */
uint8_t lastlen; /* length of last reported static dir */
pid_t pid[CONFIG_MAX_TASKS]; /* Snapshot of all active task IDs */
FAR const char *lastread; /* Pointer to last static dir read */
};
/* Level 1 is an internal virtual directory (such as /proc/fs) which
* will contain one or more additional static entries based on the
* configuration.
*/
struct procfs_level1_s
{
struct procfs_dir_priv_s base; /* Base struct for ProcFS dir */
/* Our private data */
uint8_t lastlen; /* length of last reported static dir */
uint8_t subdirlen; /* Length of the subdir search */
uint16_t firstindex; /* Index of 1st entry matching this subdir */
FAR const char *lastread; /* Pointer to last static dir read */
};
/****************************************************************************
* Private Functions
****************************************************************************/
#ifndef CONFIG_FS_PROCFS_EXCLUDE_PROCESS
/****************************************************************************
* Name: procfs_enum
****************************************************************************/
static void procfs_enum(FAR struct tcb_s *tcb, FAR void *arg)
{
FAR struct procfs_level0_s *dir = (FAR struct procfs_level0_s *)arg;
int index;
DEBUGASSERT(dir);
/* Add the PID to the list */
index = dir->base.nentries;
DEBUGASSERT(index < CONFIG_MAX_TASKS);
dir->pid[index] = tcb->pid;
dir->base.nentries = index + 1;
}
#endif
/****************************************************************************
* Name: procfs_open
****************************************************************************/
static int procfs_open(FAR struct file *filep, FAR const char *relpath,
int oflags, mode_t mode)
{
int x, ret = -ENOENT;
finfo("Open '%s'\n", relpath);
/* Perform the stat based on the procfs_entry operations */
for (x = 0; x < g_procfs_entrycount; x++)
{
/* Test if the path matches this entry's specification */
if (match(g_procfs_entries[x].pathpattern, relpath))
{
/* Match found! Stat using this procfs entry */
DEBUGASSERT(g_procfs_entries[x].ops &&
g_procfs_entries[x].ops->open);
ret = g_procfs_entries[x].ops->open(filep, relpath, oflags, mode);
if (ret == OK)
{
DEBUGASSERT(filep->f_priv);
((struct procfs_file_s *) filep->f_priv)->procfsentry =
&g_procfs_entries[x];
}
}
}
return ret;
}
/****************************************************************************
* Name: procfs_close
****************************************************************************/
static int procfs_close(FAR struct file *filep)
{
FAR struct procfs_file_s *attr;
/* Recover our private data from the struct file instance */
attr = (FAR struct procfs_file_s *)filep->f_priv;
DEBUGASSERT(attr);
/* Release the file attributes structure */
kmm_free(attr);
filep->f_priv = NULL;
return OK;
}
/****************************************************************************
* Name: procfs_read
****************************************************************************/
static ssize_t procfs_read(FAR struct file *filep, FAR char *buffer,
size_t buflen)
{
FAR struct procfs_file_s *handler;
ssize_t ret = 0;
finfo("buffer=%p buflen=%d\n", buffer, (int)buflen);
/* Recover our private data from the struct file instance */
handler = (FAR struct procfs_file_s *)filep->f_priv;
DEBUGASSERT(handler);
/* Call the handler's read routine */
ret = handler->procfsentry->ops->read(filep, buffer, buflen);
return ret;
}
/****************************************************************************
* Name: procfs_write
****************************************************************************/
static ssize_t procfs_write(FAR struct file *filep, FAR const char *buffer,
size_t buflen)
{
FAR struct procfs_file_s *handler;
ssize_t ret = 0;
finfo("buffer=%p buflen=%d\n", buffer, (int)buflen);
/* Recover our private data from the struct file instance */
handler = (FAR struct procfs_file_s *)filep->f_priv;
DEBUGASSERT(handler);
/* Call the handler's read routine */
if (handler->procfsentry->ops->write)
{
ret = handler->procfsentry->ops->write(filep, buffer, buflen);
}
return ret;
}
/****************************************************************************
* Name: procfs_ioctl
****************************************************************************/
static int procfs_ioctl(FAR struct file *filep, int cmd, unsigned long arg)
{
finfo("cmd: %d arg: %08lx\n", cmd, arg);
/* No IOCTL commands supported */
return -ENOTTY;
}
/****************************************************************************
* Name: procfs_dup
*
* Description:
* Duplicate open file data in the new file structure.
*
****************************************************************************/
static int procfs_dup(FAR const struct file *oldp, FAR struct file *newp)
{
FAR struct procfs_file_s *oldattr;
finfo("Dup %p->%p\n", oldp, newp);
/* Recover our private data from the old struct file instance */
oldattr = (FAR struct procfs_file_s *)oldp->f_priv;
DEBUGASSERT(oldattr);
/* Allow lower-level handler do the dup to get it's extra data */
return oldattr->procfsentry->ops->dup(oldp, newp);
}
/****************************************************************************
* Name: procfs_opendir
*
* Description:
* Open a directory for read access
*
****************************************************************************/
static int procfs_opendir(FAR struct inode *mountpt, FAR const char *relpath,
FAR struct fs_dirent_s *dir)
{
FAR struct procfs_level0_s *level0;
FAR struct procfs_dir_priv_s *dirpriv;
FAR void *priv = NULL;
irqstate_t flags;
finfo("relpath: \"%s\"\n", relpath ? relpath : "NULL");
DEBUGASSERT(mountpt && relpath && dir && !dir->u.procfs);
/* The relative must be either:
*
* "" - The top level directory of task/thread IDs
* "<pid>" - The sub-directory of task/thread attributes
*/
if (!relpath || relpath[0] == '\0')
{
/* The path refers to the top level directory. Allocate the level0
* dirent structure.
*/
level0 = (FAR struct procfs_level0_s *)
kmm_zalloc(sizeof(struct procfs_level0_s));
if (!level0)
{
ferr("ERROR: Failed to allocate the level0 directory structure\n");
return -ENOMEM;
}
/* Take a snapshot of all currently active tasks. Any new tasks
* added between the opendir() and closedir() call will not be
* visible.
*
* NOTE that interrupts must be disabled throughout the traversal.
*/
#ifndef CONFIG_FS_PROCFS_EXCLUDE_PROCESS
flags = enter_critical_section();
sched_foreach(procfs_enum, level0);
leave_critical_section(flags);
#else
level0->base.index = 0;
level0->base.nentries = 0;
#endif
/* Initialize lastread entries */
level0->lastread = "";
level0->lastlen = 0;
level0->base.procfsentry = NULL;
priv = (FAR void *)level0;
}
else
{
int x, ret;
int len = strlen(relpath);
/* Search the static array of procfs_entries */
for (x = 0; x < g_procfs_entrycount; x++)
{
/* Test if the path matches this entry's specification */
if (match(g_procfs_entries[x].pathpattern, relpath))
{
/* Match found! Call the handler's opendir routine. If successful,
* this opendir routine will create an entry derived from struct
* procfs_dir_priv_s as dir->u.procfs.
*/
DEBUGASSERT(g_procfs_entries[x].ops && g_procfs_entries[x].ops->opendir);
ret = g_procfs_entries[x].ops->opendir(relpath, dir);
if (ret == OK)
{
DEBUGASSERT(dir->u.procfs);
/* Set the procfs_entry handler */
dirpriv = (FAR struct procfs_dir_priv_s *)dir->u.procfs;
dirpriv->procfsentry = &g_procfs_entries[x];
}
return ret;
}
/* Test for a sub-string match (e.g. "ls /proc/fs") */
else if (strncmp(g_procfs_entries[x].pathpattern, relpath, len) == 0)
{
FAR struct procfs_level1_s *level1;
/* Doing an intermediate directory search */
/* The path refers to the top level directory. Allocate the level1
* dirent structure.
*/
level1 = (FAR struct procfs_level1_s *)
kmm_zalloc(sizeof(struct procfs_level1_s));
if (!level1)
{
ferr("ERROR: Failed to allocate the level0 directory structure\n");
return -ENOMEM;
}
level1->base.level = 1;
level1->base.index = x;
level1->firstindex = x;
level1->subdirlen = len;
level1->lastread = "";
level1->lastlen = 0;
level1->base.procfsentry = NULL;
priv = (FAR void *)level1;
break;
}
}
}
dir->u.procfs = priv;
return OK;
}
/****************************************************************************
* Name: procfs_closedir
*
* Description: Close the directory listing
*
****************************************************************************/
static int procfs_closedir(FAR struct inode *mountpt,
FAR struct fs_dirent_s *dir)
{
FAR struct procfs_dir_priv_s *priv;
DEBUGASSERT(mountpt && dir && dir->u.procfs);
priv = dir->u.procfs;
if (priv)
{
kmm_free(priv);
}
dir->u.procfs = NULL;
return OK;
}
/****************************************************************************
* Name: procfs_readdir
*
* Description: Read the next directory entry
*
****************************************************************************/
static int procfs_readdir(struct inode *mountpt, struct fs_dirent_s *dir)
{
FAR struct procfs_dir_priv_s *priv;
FAR struct procfs_level0_s *level0;
FAR struct tcb_s *tcb;
FAR const char *name = NULL;
unsigned int index;
irqstate_t flags;
pid_t pid;
int ret = -ENOENT;
DEBUGASSERT(mountpt && dir && dir->u.procfs);
priv = dir->u.procfs;
/* Are we reading the 1st directory level with dynamic PID and static
* entries?
*/
if (priv->level == 0)
{
level0 = (FAR struct procfs_level0_s *)priv;
/* Have we reached the end of the PID information */
index = priv->index;
if (index >= priv->nentries)
{
/* We must report the next static entry ... no more PID entries.
* skip any entries with wildcards in the first segment of the
* directory name.
*/
while (index < priv->nentries + g_procfs_entrycount)
{
name = g_procfs_entries[index - priv->nentries].pathpattern;
while (*name != '/' && *name != '\0')
{
if (*name == '*' || *name == '[' || *name == '?')
{
/* Wildcard found. Skip this entry */
index++;
name = NULL;
break;
}
name++;
}
/* Test if we skipped this entry */
if (name != NULL)
{
/* This entry is okay to report. Test if it has a duplicate
* first level name as the one we just reported. This could
* happen in the event of procfs_entry_s such as:
*
* fs/smartfs
* fs/nfs
* fs/nxffs
*/
name = g_procfs_entries[index - priv->nentries].pathpattern;
if (!level0->lastlen || (strncmp(name, level0->lastread,
level0->lastlen) != 0))
{
/* Not a duplicate, return the first segment of this
* entry
*/
break;
}
else
{
/* Skip this entry ... duplicate 1st level name found */
index++;
}
}
}
/* Test if we are at the end of the directory */
if (index >= priv->nentries + g_procfs_entrycount)
{
/* We signal the end of the directory by returning the special
* error -ENOENT
*/
finfo("Entry %d: End of directory\n", index);
ret = -ENOENT;
}
else
{
/* Report the next static entry */
level0->lastlen = strcspn(name, "/");
level0->lastread = name;
strncpy(dir->fd_dir.d_name, name, level0->lastlen);
dir->fd_dir.d_name[level0->lastlen] = '\0';
if (name[level0->lastlen] == '/')
{
dir->fd_dir.d_type = DTYPE_DIRECTORY;
}
else
{
dir->fd_dir.d_type = DTYPE_FILE;
}
/* Advance to next entry for the next read */
priv->index = index;
ret = OK;
}
}
#ifndef CONFIG_FS_PROCFS_EXCLUDE_PROCESS
else
{
/* Verify that the pid still refers to an active task/thread */
pid = level0->pid[index];
flags = enter_critical_section();
tcb = sched_gettcb(pid);
leave_critical_section(flags);
if (!tcb)
{
ferr("ERROR: PID %d is no longer valid\n", (int)pid);
return -ENOENT;
}
/* Save the filename=pid and file type=directory */
dir->fd_dir.d_type = DTYPE_DIRECTORY;
snprintf(dir->fd_dir.d_name, NAME_MAX+1, "%d", (int)pid);
/* Set up the next directory entry offset. NOTE that we could use the
* standard f_pos instead of our own private index.
*/
level0->base.index = index + 1;
ret = OK;
}
#endif /* CONFIG_FS_PROCFS_EXCLUDE_PROCESS */
}
/* Are we reading an intermediate subdirectory? */
else if (priv->level > 0 && priv->procfsentry == NULL)
{
FAR struct procfs_level1_s *level1;
level1 = (FAR struct procfs_level1_s *) priv;
/* Test if this entry matches. We assume all entries of the same
* subdirectory are listed in order in the procfs_entry array.
*/
if (strncmp(g_procfs_entries[level1->base.index].pathpattern,
g_procfs_entries[level1->firstindex].pathpattern,
level1->subdirlen) == 0)
{
/* This entry matches. Report the subdir entry */
name = &g_procfs_entries[level1->base.index].pathpattern[
level1->subdirlen + 1];
level1->lastlen = strcspn(name, "/");
level1->lastread = name;
strncpy(dir->fd_dir.d_name, name, level1->lastlen);
/* Some of the search entries contain '**' wildcards. When we
* report the entry name, we must remove this wildcard search
* specifier.
*/
while (dir->fd_dir.d_name[level1->lastlen - 1] == '*')
{
level1->lastlen--;
}
dir->fd_dir.d_name[level1->lastlen] = '\0';
if (name[level1->lastlen] == '/')
{
dir->fd_dir.d_type = DTYPE_DIRECTORY;
}
else
{
dir->fd_dir.d_type = DTYPE_FILE;
}
level1->base.index++;
ret = OK;
}
else
{
/* No more entries in the subdirectory */
ret = -ENOENT;
}
}
else
{
/* We are performing a directory search of one of the subdirectories
* and we must let the handler perform the read.
*/
DEBUGASSERT(priv->procfsentry && priv->procfsentry->ops->readdir);
ret = priv->procfsentry->ops->readdir(dir);
}
return ret;
}
/****************************************************************************
* Name: procfs_rewindir
*
* Description: Reset directory read to the first entry
*
****************************************************************************/
static int procfs_rewinddir(struct inode *mountpt, struct fs_dirent_s *dir)
{
FAR struct procfs_dir_priv_s *priv;
DEBUGASSERT(mountpt && dir && dir->u.procfs);
priv = dir->u.procfs;
if (priv->level > 0 && priv->procfsentry == NULL)
{
priv->index = ((struct procfs_level1_s *) priv)->firstindex;
}
else
{
priv->index = 0;
}
return OK;
}
/****************************************************************************
* Name: procfs_bind
*
* Description: This implements a portion of the mount operation. This
* function allocates and initializes the mountpoint private data and
* binds the blockdriver inode to the filesystem private data. The final
* binding of the private data (containing the blockdriver) to the
* mountpoint is performed by mount().
*
****************************************************************************/
static int procfs_bind(FAR struct inode *blkdriver, const void *data,
void **handle)
{
/* Make sure that we are properly initialized */
procfs_initialize();
return OK;
}
/****************************************************************************
* Name: procfs_unbind
*
* Description: This implements the filesystem portion of the umount
* operation.
*
****************************************************************************/
static int procfs_unbind(void *handle, FAR struct inode **blkdriver,
unsigned int flags)
{
return OK;
}
/****************************************************************************
* Name: procfs_statfs
*
* Description: Return filesystem statistics
*
****************************************************************************/
static int procfs_statfs(struct inode *mountpt, struct statfs *buf)
{
/* Fill in the statfs info */
memset(buf, 0, sizeof(struct statfs));
buf->f_type = PROCFS_MAGIC;
buf->f_bsize = 0;
buf->f_blocks = 0;
buf->f_bfree = 0;
buf->f_bavail = 0;
buf->f_namelen = NAME_MAX;
return OK;
}
/****************************************************************************
* Name: procfs_stat
*
* Description: Return information about a file or directory
*
****************************************************************************/
static int procfs_stat(struct inode *mountpt, const char *relpath,
struct stat *buf)
{
int ret = -ENOSYS;
/* Three path forms are accepted:
*
* "" - The relative path refers to the top level directory
* "<pid>" - If <pid> refers to a currently active task/thread, then it
* is a directory
* "<pid>/<attr>" - If <attr> is a recognized attribute then, then it
* is a file.
*/
if (!relpath || relpath[0] == '\0')
{
/* The path refers to the top level directory */
/* It's a read-only directory */
buf->st_mode = S_IFDIR | S_IROTH | S_IRGRP | S_IRUSR;
ret = OK;
}
else
{
int x;
int len = strlen(relpath);
/* Perform the stat based on the procfs_entry operations */
for (x = 0; x < g_procfs_entrycount; x++)
{
/* Test if the path matches this entry's specification */
if (match(g_procfs_entries[x].pathpattern, relpath))
{
/* Match found! Stat using this procfs entry */
DEBUGASSERT(g_procfs_entries[x].ops &&
g_procfs_entries[x].ops->stat);
return g_procfs_entries[x].ops->stat(relpath, buf);
}
/* Test for an internal subdirectory stat */
else if (strncmp(g_procfs_entries[x].pathpattern, relpath, len) == 0)
{
/* It's an internal subdirectory */
buf->st_mode = S_IFDIR | S_IROTH | S_IRGRP | S_IRUSR;
ret = OK;
break;
}
}
}
/* File/directory size, access block size */
buf->st_size = 0;
buf->st_blksize = 0;
buf->st_blocks = 0;
return ret;
}
/****************************************************************************
* Name: procfs_initialize
*
* Description:
* Configure the initial set of entries in the procfs file system.
*
* Input Parameters:
* None
*
* Returned Value:
* Zero (OK) on success; a negated errno value on failure
*
****************************************************************************/
#ifdef CONFIG_FS_PROCFS_REGISTER
int procfs_initialize(void)
{
/* Are we already initialized? */
if (g_procfs_entries == NULL)
{
/* No.. allocate a modifyable list of entries */
g_procfs_entries = (FAR struct procfs_entry_s *)
kmm_malloc(sizeof(g_base_entries));
if (g_procfs_entries == NULL)
{
return -ENOMEM;
}
/* And copy the fixed entries into the allocated array */
memcpy(g_procfs_entries, g_base_entries, sizeof(g_base_entries));
g_procfs_entrycount = g_base_entrycount;
}
return OK;
}
#endif
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: procfs_register
*
* Description:
* Add a new entry to the procfs file system.
*
* NOTE: This function should be called *prior* to mounting the procfs
* file system to prevent concurrency problems with the modification of
* the procfs data set while it is in use.
*
* Input Parameters:
* entry - Describes the entry to be registered.
*
* Returned Value:
* Zero (OK) on success; a negated errno value on failure
*
****************************************************************************/
#ifdef CONFIG_FS_PROCFS_REGISTER
int procfs_register(FAR const struct procfs_entry_s *entry)
{
FAR struct procfs_entry_s *newtable;
unsigned int newcount;
size_t newsize;
int ret;
/* Make sure that we are properly initialized */
procfs_initialize();
/* realloc the table of procfs entries.
*
* REVISIT: This reallocation may free memory previously used for the
* procfs entry table. If that table were actively in use, then that
* could cause procfs logic to use a stale memory pointer! We avoid that
* problem by requiring that the procfs file be unmounted when the new
* entry is added. That requirment, however, is not enforced explicitly.
*
* Locking the scheduler as done below is insufficient. As would be just
* marking the entries as volatile.
*/
newcount = g_procfs_entrycount + 1;
newsize = newcount * sizeof(struct procfs_entry_s);
sched_lock();
newtable = (FAR struct procfs_entry_s *)kmm_realloc(g_procfs_entries, newsize);
if (newtable == NULL)
{
/* Reallocation failed! */
ret = -ENOMEM;
}
else
{
/* Copy the new entry at the end of the reallocated table */
memcpy(&newtable[g_procfs_entrycount], entry, sizeof(struct procfs_entry_s));
/* Instantiate the reallocated table */
g_procfs_entries = newtable;
g_procfs_entrycount = newcount;
ret = OK;
}
sched_unlock();
return ret;
}
#endif
#endif /* !CONFIG_DISABLE_MOUNTPOINT && CONFIG_FS_PROCFS */
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