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incubator-nuttx/fs/procfs/fs_procfsproc.c

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/****************************************************************************
* fs/procfs/fs_procfsproc.c
*
* Copyright (C) 2013 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/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 <arch/irq.h>
#if !defined(CONFIG_DISABLE_MOUNTPOINT) && defined(CONFIG_FS_PROCFS)
#ifndef CONFIG_FS_PROCFS_EXCLUDE_PROCESS
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
#define STATUS_LINELEN 32
/****************************************************************************
* Private Types
****************************************************************************/
/* This enumeration identifies all of the thread attributes that can be
* accessed via the procfs file system.
*/
enum process_attr_e
{
PROCFS_STATUS = 0, /* Task/thread status */
PROCFS_CMDLINE, /* Command line */
};
#define PROCFS_NATTRS 2
/* This structure describes one open "file" */
struct process_file_s
{
struct procfs_file_s base; /* Base open file structure */
uint8_t type; /* See enum process_type_e */
pid_t pid; /* Task/thread ID */
uint8_t attr; /* See enum process_attr_e */
char line[STATUS_LINELEN]; /* Pre-allocated buffer for formatted lines */
};
/* Level 0 is the directory of active tasks */
struct process_level0_s
{
uint8_t level; /* Directory level. Currently 0 or 1 */
uint16_t index; /* Index to the next directory entry */
uint16_t nentries; /* Number of directory entries */
pid_t pid[CONFIG_MAX_TASKS]; /* Snapshot of all active task IDs */
};
/* Level 1 is the directory of task attributes */
struct process_level1_s
{
struct procfs_dir_priv_s base; /* Base directory private data */
/* Our specific data for context control */
pid_t pid; /* ID of task for attributes */
};
/****************************************************************************
* Private Function Prototypes
****************************************************************************/
/* Helpers */
static int process_findattr(FAR const char *attr);
static ssize_t process_status(FAR struct process_file_s *attr,
FAR struct tcb_s *tcb, FAR char *buffer, size_t buflen,
off_t offset);
static ssize_t process_cmdline(FAR struct process_file_s *attr,
FAR struct tcb_s *tcb, FAR char *buffer, size_t buflen,
off_t offset);
/* File system methods */
static int process_open(FAR struct file *filep, FAR const char *relpath,
int oflags, mode_t mode);
static int process_close(FAR struct file *filep);
static ssize_t process_read(FAR struct file *filep, FAR char *buffer,
size_t buflen);
static int process_dup(FAR const struct file *oldp,
FAR struct file *newp);
static int process_opendir(const char *relpath, FAR struct fs_dirent_s *dir);
static int process_closedir(FAR struct fs_dirent_s *dir);
static int process_readdir(FAR struct fs_dirent_s *dir);
static int process_rewinddir(FAR struct fs_dirent_s *dir);
static int process_stat(FAR const char *relpath, FAR struct stat *buf);
/****************************************************************************
* Private Variables
****************************************************************************/
/****************************************************************************
* Public Variables
****************************************************************************/
/* 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 procfs_operations process_operations =
{
process_open, /* open */
process_close, /* close */
process_read, /* read */
NULL, /* write */
process_dup, /* dup */
process_opendir, /* opendir */
process_closedir, /* closedir */
process_readdir, /* readdir */
process_rewinddir, /* rewinddir */
process_stat /* stat */
};
/* This is the list of all attribute strings. Indexing is with the same
* values as enum process_attr_e.
*/
static const char *g_attrstrings[PROCFS_NATTRS] =
{
"status",
"cmdline"
};
static const char *g_statenames[] =
{
"Invalid",
"Pending unlock",
"Ready",
"Running",
"Inactive",
"Semaphore wait",
#ifndef CONFIG_DISABLE_MQUEUE
"Signal wait",
#endif
#ifndef CONFIG_DISABLE_MQUEUE
"MQ not empty wait",
"MQ no full wait"
#endif
};
static const char *g_ttypenames[4] =
{
"Task",
"pthread",
"Kernel thread",
"--?--"
};
/****************************************************************************
* Private Functions
****************************************************************************/
/****************************************************************************
* Name: process_findattr
****************************************************************************/
static int process_findattr(FAR const char *attr)
{
int i;
/* Search every string in g_attrstrings or until a match is found */
for (i = 0; i < PROCFS_NATTRS; i++)
{
if (strcmp(g_attrstrings[i], attr) == 0)
{
return i;
}
}
/* Not found */
return -ENOENT;
}
/****************************************************************************
* Name: process_status
****************************************************************************/
static ssize_t process_status(FAR struct process_file_s *attr,
FAR struct tcb_s *tcb, FAR char *buffer,
size_t buflen, off_t offset)
{
FAR const char *name;
size_t remaining;
size_t linesize;
size_t copysize;
size_t totalsize;
remaining = buflen;
totalsize = 0;
/* Show the task name */
#if CONFIG_TASK_NAME_SIZE > 0
name = tcb->name;
#else
name = "<noname>";
#endif
linesize = snprintf(attr->line, STATUS_LINELEN, "%-12s%s\n",
"Name:", name);
copysize = procfs_memcpy(attr->line, linesize, buffer, remaining, &offset);
totalsize += copysize;
buffer += copysize;
remaining -= copysize;
if (totalsize >= buflen)
{
return totalsize;
}
/* Show the thread type */
linesize = snprintf(attr->line, STATUS_LINELEN, "%-12s%s\n", "Type:",
g_ttypenames[(tcb->flags & TCB_FLAG_TTYPE_MASK) >>
TCB_FLAG_TTYPE_SHIFT]);
copysize = procfs_memcpy(attr->line, linesize, buffer, remaining, &offset);
totalsize += copysize;
buffer += copysize;
remaining -= copysize;
if (totalsize >= buflen)
{
return totalsize;
}
/* Show the thread state */
linesize = snprintf(attr->line, STATUS_LINELEN, "%-12s%s\n", "State:",
g_statenames[tcb->task_state]);
copysize = procfs_memcpy(attr->line, linesize, buffer, remaining, &offset);
totalsize += copysize;
buffer += copysize;
remaining -= copysize;
if (totalsize >= buflen)
{
return totalsize;
}
/* Show the thread priority */
#ifdef CONFIG_PRIORITY_INHERITANCE
linesize = snprintf(attr->line, STATUS_LINELEN, "%-12s%d (%d)\n", "Priority:",
tcb->sched_priority, tcb->base_priority);
#else
linesize = snprintf(attr->line, STATUS_LINELEN, "%-12s%d\n", "Priority:",
tcb->sched_priority);
#endif
copysize = procfs_memcpy(attr->line, linesize, buffer, remaining, &offset);
totalsize += copysize;
buffer += copysize;
remaining -= copysize;
if (totalsize >= buflen)
{
return totalsize;
}
/* Show the scheduler */
linesize = snprintf(attr->line, STATUS_LINELEN, "%-12s%s\n", "Scheduler:",
tcb->flags & TCB_FLAG_ROUND_ROBIN ? "SCHED_RR" : "SCHED_FIFO");
copysize = procfs_memcpy(attr->line, linesize, buffer, remaining, &offset);
totalsize += copysize;
buffer += copysize;
remaining -= copysize;
if (totalsize >= buflen)
{
return totalsize;
}
/* Show the signal mast */
#ifndef CONFIG_DISABLE_SIGNALS
linesize = snprintf(attr->line, STATUS_LINELEN, "%-12s%08x\n", "SigMask:",
tcb->sigprocmask);
copysize = procfs_memcpy(attr->line, linesize, buffer, remaining, &offset);
totalsize += copysize;
#endif
return totalsize;
}
/****************************************************************************
* Name: process_cmdline
****************************************************************************/
static ssize_t process_cmdline(FAR struct process_file_s *attr,
FAR struct tcb_s *tcb, FAR char *buffer,
size_t buflen, off_t offset)
{
FAR struct task_tcb_s *ttcb;
FAR const char *name;
FAR char **argv;
size_t remaining;
size_t linesize;
size_t copysize;
size_t totalsize;
remaining = buflen;
totalsize = 0;
/* Show the task name */
#if CONFIG_TASK_NAME_SIZE > 0
name = tcb->name;
#else
name = "<noname>";
#endif
linesize = strlen(name);
memcpy(attr->line, name, linesize);
copysize = procfs_memcpy(attr->line, linesize, buffer, remaining, &offset);
totalsize += copysize;
buffer += copysize;
remaining -= copysize;
if (totalsize >= buflen)
{
return totalsize;
}
#ifndef CONFIG_DISABLE_PTHREAD
/* Show the pthread argument */
if ((tcb->flags & TCB_FLAG_TTYPE_MASK) == TCB_FLAG_TTYPE_PTHREAD)
{
FAR struct pthread_tcb_s *ptcb = (FAR struct pthread_tcb_s *)tcb;
linesize = snprintf(attr->line, STATUS_LINELEN, " 0x%p\n", ptcb->arg);
copysize = procfs_memcpy(attr->line, linesize, buffer, remaining, &offset);
totalsize += copysize;
buffer += copysize;
remaining -= copysize;
return totalsize;
}
#endif
/* Show the task argument list (skipping over the name) */
ttcb = (FAR struct task_tcb_s *)tcb;
for (argv = ttcb->argv + 1; *argv; argv++)
{
linesize = snprintf(attr->line, STATUS_LINELEN, " %s", *argv);
copysize = procfs_memcpy(attr->line, linesize, buffer, remaining, &offset);
totalsize += copysize;
buffer += copysize;
remaining -= copysize;
if (totalsize >= buflen)
{
return totalsize;
}
}
linesize = snprintf(attr->line, STATUS_LINELEN, "\n");
copysize = procfs_memcpy(attr->line, linesize, buffer, remaining, &offset);
totalsize += copysize;
return totalsize;
}
/****************************************************************************
* Name: process_open
****************************************************************************/
static int process_open(FAR struct file *filep, FAR const char *relpath,
int oflags, mode_t mode)
{
FAR struct process_file_s *attr;
FAR struct tcb_s *tcb;
FAR char *ptr;
irqstate_t flags;
unsigned long tmp;
pid_t pid;
int attrndx;
fvdbg("Open '%s'\n", relpath);
/* PROCFS is read-only. Any attempt to open with any kind of write
* access is not permitted.
*
* REVISIT: Write-able proc files could be quite useful.
*/
if ((oflags & O_WRONLY) != 0 || (oflags & O_RDONLY) == 0)
{
fdbg("ERROR: Only O_RDONLY supported\n");
return -EACCES;
}
/* The first segment of the relative path should be a task/thread ID */
ptr = NULL;
tmp = strtoul(relpath, &ptr, 10);
if (!ptr || *ptr != '/')
{
fdbg("ERROR: Invalid path \"%s\"\n", relpath);
return -ENOENT;
}
/* Skip over the slash */
ptr++;
/* A valid PID would be in the range of 0-32767 (0 is reserved for the
* IDLE thread).
*/
if (tmp >= 32768)
{
fdbg("ERROR: Invalid PID %ld\n", tmp);
return -ENOENT;
}
/* Now verify that a task with this task/thread ID exists */
pid = (pid_t)tmp;
flags = irqsave();
tcb = sched_gettcb(pid);
irqrestore(flags);
if (!tcb)
{
fdbg("ERROR: PID %d is no longer valid\n", (int)pid);
return -ENOENT;
}
/* The second segment of the relpath should be a well known attribute of
* the task/thread.
*/
attrndx = process_findattr(ptr);
if (attrndx < 0)
{
fdbg("ERROR: Invalid attribute %s\n", ptr);
return -ENOENT;
}
/* Allocate a container to hold the task and attribute selection */
attr = (FAR struct process_file_s *)kzalloc(sizeof(struct process_file_s));
if (!attr)
{
fdbg("ERROR: Failed to allocate file attributes\n");
return -ENOMEM;
}
/* Initialize the file attributes */
attr->pid = pid;
attr->attr = attrndx;
/* Save the index as the open-specific state in filep->f_priv */
filep->f_priv = (FAR void *)attr;
return OK;
}
/****************************************************************************
* Name: process_close
****************************************************************************/
static int process_close(FAR struct file *filep)
{
FAR struct process_file_s *attr;
/* Recover our private data from the struct file instance */
attr = (FAR struct process_file_s *)filep->f_priv;
DEBUGASSERT(attr);
/* Release the file attributes structure */
kfree(attr);
filep->f_priv = NULL;
return OK;
}
/****************************************************************************
* Name: process_read
****************************************************************************/
static ssize_t process_read(FAR struct file *filep, FAR char *buffer,
size_t buflen)
{
FAR struct process_file_s *attr;
FAR struct tcb_s *tcb;
irqstate_t flags;
ssize_t ret;
fvdbg("buffer=%p buflen=%d\n", buffer, (int)buflen);
/* Recover our private data from the struct file instance */
attr = (FAR struct process_file_s *)filep->f_priv;
DEBUGASSERT(attr);
/* Verify that the thread is still valid */
flags = irqsave();
tcb = sched_gettcb(attr->pid);
if (!tcb)
{
fdbg("ERROR: PID %d is not valid\n", (int)attr->pid);
irqrestore(flags);
return -ENODEV;
}
/* Provide the requested data */
switch (attr->attr)
{
default:
case PROCFS_STATUS: /* Task/thread status */
ret = process_status(attr, tcb, buffer, buflen, filep->f_pos);
break;
case PROCFS_CMDLINE: /* Command line */
ret = process_cmdline(attr, tcb, buffer, buflen, filep->f_pos);
break;
}
irqrestore(flags);
/* Update the file offset */
if (ret > 0)
{
filep->f_pos += ret;
}
return ret;
}
/****************************************************************************
* Name: process_dup
*
* Description:
* Duplicate open file data in the new file structure.
*
****************************************************************************/
static int process_dup(FAR const struct file *oldp, FAR struct file *newp)
{
FAR struct process_file_s *oldattr;
FAR struct process_file_s *newattr;
fvdbg("Dup %p->%p\n", oldp, newp);
/* Recover our private data from the old struct file instance */
oldattr = (FAR struct process_file_s *)oldp->f_priv;
DEBUGASSERT(oldattr);
/* Allocate a new container to hold the task and attribute selection */
newattr = (FAR struct process_file_s *)kzalloc(sizeof(struct process_file_s));
if (!newattr)
{
fdbg("ERROR: Failed to allocate file attributes\n");
return -ENOMEM;
}
/* The copy the file attribtes from the old attributes to the new */
memcpy(newattr, oldattr, sizeof(struct process_file_s));
/* Save the new attributes in the new file structure */
newp->f_priv = (FAR void *)newattr;
return OK;
}
/****************************************************************************
* Name: process_opendir
*
* Description:
* Open a directory for read access
*
****************************************************************************/
static int process_opendir(FAR const char *relpath, FAR struct fs_dirent_s *dir)
{
FAR struct tcb_s *tcb;
irqstate_t flags;
fvdbg("relpath: \"%s\"\n", relpath ? relpath : "NULL");
DEBUGASSERT(relpath && dir && !dir->u.procfs);
/* The relative must be:
*
* "<pid>" - The sub-directory of task/thread attributes
*/
FAR struct process_level1_s *level1;
unsigned long tmp;
FAR char *ptr;
pid_t pid;
/* Otherwise, the relative path should be a valid task/thread ID */
ptr = NULL;
tmp = strtoul(relpath, &ptr, 10);
if (!ptr || (*ptr != '\0' && strcmp(ptr, "/") != 0))
{
/* strtoul failed or there is something in the path after the pid */
fdbg("ERROR: Invalid path \"%s\"\n", relpath);
return -ENOENT;
}
/* A valid PID would be in the range of 0-32767 (0 is reserved for the
* IDLE thread).
*/
if (tmp >= 32768)
{
fdbg("ERROR: Invalid PID %ld\n", tmp);
return -ENOENT;
}
/* Now verify that a task with this task/thread ID exists */
pid = (pid_t)tmp;
flags = irqsave();
tcb = sched_gettcb(pid);
irqrestore(flags);
if (!tcb)
{
fdbg("ERROR: PID %d is not valid\n", (int)pid);
return -ENOENT;
}
/* Was the <pid> the final element of the path? */
if (*ptr != '\0' && strcmp(ptr, "/") != 0)
{
/* There is something in the path after the pid */
fdbg("ERROR: Invalid path \"%s\"\n", relpath);
return -ENOENT;
}
/* The path refers to the 1st level sbdirectory. Allocate the level1
* dirent structure.
*/
level1 = (FAR struct process_level1_s *)
kzalloc(sizeof(struct process_level1_s));
if (!level1)
{
fdbg("ERROR: Failed to allocate the level1 directory structure\n");
return -ENOMEM;
}
/* Note that the index and procentry pointer were implicitly nullified
* by kzalloc(). Only the remaining, non-zero entries need be initialized.
*/
level1->base.level = 1;
level1->base.nentries = PROCFS_NATTRS;
level1->pid = pid;
dir->u.procfs = (FAR void *)level1;
return OK;
}
/****************************************************************************
* Name: process_closedir
*
* Description: Close the directory listing
*
****************************************************************************/
static int process_closedir(FAR struct fs_dirent_s *dir)
{
FAR struct process_level0_s *priv;
DEBUGASSERT(dir && dir->u.procfs);
priv = dir->u.procfs;
if (priv)
{
kfree(priv);
}
dir->u.procfs = NULL;
return OK;
}
/****************************************************************************
* Name: process_readdir
*
* Description: Read the next directory entry
*
****************************************************************************/
static int process_readdir(struct fs_dirent_s *dir)
{
FAR struct process_level1_s *level1;
FAR struct tcb_s *tcb;
unsigned int index;
irqstate_t flags;
pid_t pid;
int ret;
DEBUGASSERT(dir && dir->u.procfs);
level1 = dir->u.procfs;
/* Have we reached the end of the directory */
index = level1->base.index;
if (index >= level1->base.nentries)
{
/* We signal the end of the directory by returning the special
* error -ENOENT
*/
fvdbg("Entry %d: End of directory\n", index);
ret = -ENOENT;
}
/* We are tranversing a subdirectory of task attributes */
else
{
DEBUGASSERT(level1->base.level == 1);
/* Verify that the pid still refers to an active task/thread */
pid = level1->pid;
flags = irqsave();
tcb = sched_gettcb(pid);
irqrestore(flags);
if (!tcb)
{
fdbg("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_FILE;
strncpy(dir->fd_dir.d_name, g_attrstrings[index], NAME_MAX+1);
/* Set up the next directory entry offset. NOTE that we could use the
* standard f_pos instead of our own private index.
*/
level1->base.index = index + 1;
ret = OK;
}
return ret;
}
/****************************************************************************
* Name: process_rewindir
*
* Description: Reset directory read to the first entry
*
****************************************************************************/
static int process_rewinddir(struct fs_dirent_s *dir)
{
FAR struct process_level0_s *priv;
DEBUGASSERT(dir && dir->u.procfs);
priv = dir->u.procfs;
priv->index = 0;
return OK;
}
/****************************************************************************
* Name: process_stat
*
* Description: Return information about a file or directory
*
****************************************************************************/
static int process_stat(const char *relpath, struct stat *buf)
{
FAR struct tcb_s *tcb;
unsigned long tmp;
FAR char *ptr;
irqstate_t flags;
pid_t pid;
int ret;
/* Two path forms are accepted:
*
* "<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.
*/
ptr = NULL;
tmp = strtoul(relpath, &ptr, 10);
if (!ptr)
{
fdbg("ERROR: Invalid path \"%s\"\n", relpath);
return -ENOENT;
}
/* A valid PID would be in the range of 0-32767 (0 is reserved for the
* IDLE thread).
*/
if (tmp >= 32768)
{
fdbg("ERROR: Invalid PID %ld\n", tmp);
return -ENOENT;
}
/* Now verify that a task with this task/thread ID exists */
pid = (pid_t)tmp;
flags = irqsave();
tcb = sched_gettcb(pid);
irqrestore(flags);
if (!tcb)
{
fdbg("ERROR: PID %d is no longer valid\n", (int)pid);
return -ENOENT;
}
/* Was the <pid> the final element of the path? */
if (*ptr == '\0' || strcmp(ptr, "/") == 0)
{
/* Yes ... It's a read-only directory */
buf->st_mode = S_IFDIR|S_IROTH|S_IRGRP|S_IRUSR;
}
/* Verify that the process ID is followed by valid path segment delimiter */
else if (*ptr != '/')
{
/* We are required to return -ENOENT all all invalid paths */
fdbg("ERROR: Bad delimiter '%c' in relpath '%s'\n", *ptr, relpath);
return -ENOENT;
}
else
{
/* Otherwise, the second segment of the relpath should be a well
* known attribute of the task/thread.
*/
/* Skip over the path segment delimiter */
ptr++;
/* Lookup the well-known attribute string. */
ret = process_findattr(ptr);
if (ret < 0)
{
fdbg("ERROR: Invalid attribute %s\n", ptr);
return -ENOENT;
}
/* If the attribute exists, it is the name for a read-only file. */
buf->st_mode = S_IFREG|S_IROTH|S_IRGRP|S_IRUSR;
}
/* File/directory size, access block size */
buf->st_size = 0;
buf->st_blksize = 0;
buf->st_blocks = 0;
return OK;
}
/****************************************************************************
* Public Functions
****************************************************************************/
#endif /* CONFIG_FS_PROCFS_EXCLUDE_PROCESS */
#endif /* !CONFIG_DISABLE_MOUNTPOINT && CONFIG_FS_PROCFS */
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