openharmony_kernel_liteos_a/fs/proc/src/proc_file.c

694 lines
17 KiB
C

/*
* Copyright (c) 2013-2019 Huawei Technologies Co., Ltd. All rights reserved.
* Copyright (c) 2020-2021 Huawei Device Co., Ltd. All rights reserved.
*
* 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 of the copyright holder 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 HOLDER 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.
*/
#include "proc_file.h"
#include <stdio.h>
#include <linux/errno.h>
#include <linux/module.h>
#include "internal.h"
#include "user_copy.h"
#define MIN(a, b) ((a) < (b) ? (a) : (b))
#define PROC_ROOTDIR_NAMELEN 5
#define PROC_INUSE 2
DEFINE_SPINLOCK(procfsLock);
bool procfsInit = false;
static struct ProcFile g_procPf = {
.fPos = 0,
};
static struct ProcDirEntry g_procRootDirEntry = {
.nameLen = 5,
.mode = S_IFDIR | PROCFS_DEFAULT_MODE,
.count = ATOMIC_INIT(1),
.procFileOps = NULL,
.parent = &g_procRootDirEntry,
.name = "/proc",
.subdir = NULL,
.next = NULL,
.pf = &g_procPf,
.type = VNODE_TYPE_DIR,
};
int ProcMatch(unsigned int len, const char *name, struct ProcDirEntry *pn)
{
if (len != pn->nameLen) {
return 0;
}
return !strncmp(name, pn->name, len);
}
static struct ProcDirEntry *ProcFindNode(struct ProcDirEntry *parent, const char *name)
{
struct ProcDirEntry *pn = NULL;
int length;
if ((parent == NULL) || (name == NULL)) {
return pn;
}
length = strlen(name);
for (pn = parent->subdir; pn != NULL; pn = pn->next) {
if ((length == pn->nameLen) && strcmp(pn->name, name) == 0) {
break;
}
}
return pn;
}
/*
* description: find the file's handle
* path: the file of fullpath
* return: the file of handle
* add by ll
*/
struct ProcDirEntry *ProcFindEntry(const char *path)
{
struct ProcDirEntry *pn = NULL;
int isfoundsub;
const char *next = NULL;
unsigned int len;
int leveltotal = 0;
int levelcount = 0;
const char *p = NULL;
const char *name = path;
while ((p = strchr(name, '/')) != NULL) {
leveltotal++;
name = p;
name++;
}
if (leveltotal < 1) {
return pn;
}
spin_lock(&procfsLock);
pn = &g_procRootDirEntry;
while ((pn != NULL) && (levelcount < leveltotal)) {
levelcount++;
isfoundsub = 0;
while (pn != NULL) {
next = strchr(path, '/');
if (next == NULL) {
while (pn != NULL) {
if (strcmp(path, pn->name) == 0) {
spin_unlock(&procfsLock);
return pn;
}
pn = pn->next;
}
pn = NULL;
spin_unlock(&procfsLock);
return pn;
}
len = next - path;
if (pn == &g_procRootDirEntry) {
if (levelcount == leveltotal) {
spin_unlock(&procfsLock);
return pn;
}
len = g_procRootDirEntry.nameLen;
}
if (ProcMatch(len, path, pn)) {
isfoundsub = 1;
path += len + 1;
break;
}
pn = pn->next;
}
if ((isfoundsub == 1) && (pn != NULL)) {
pn = pn->subdir;
} else {
pn = NULL;
spin_unlock(&procfsLock);
return pn;
}
}
spin_unlock(&procfsLock);
return NULL;
}
static int CheckProcName(const char *name, struct ProcDirEntry **parent, const char **lastName)
{
struct ProcDirEntry *pn = *parent;
const char *segment = name;
const char *restName = NULL;
int length;
if (pn == NULL) {
pn = &g_procRootDirEntry;
}
spin_lock(&procfsLock);
restName = strchr(segment, '/');
for (; restName != NULL; restName = strchr(segment, '/')) {
length = restName - segment;
for (pn = pn->subdir; pn != NULL; pn = pn->next) {
if (ProcMatch(length, segment, pn)) {
break;
}
}
if (pn == NULL) {
PRINT_ERR(" Error!No such name '%s'\n", name);
spin_unlock(&procfsLock);
return -ENOENT;
}
segment = restName;
segment++;
}
*lastName = segment;
*parent = pn;
spin_unlock(&procfsLock);
return 0;
}
static struct ProcDirEntry *ProcAllocNode(struct ProcDirEntry **parent, const char *name, mode_t mode)
{
struct ProcDirEntry *pn = NULL;
const char *lastName = NULL;
int ret;
if ((name == NULL) || (strlen(name) == 0) || (procfsInit == false)) {
return pn;
}
if (CheckProcName(name, parent, &lastName) != 0) {
return pn;
}
if (strlen(lastName) > NAME_MAX) {
return pn;
}
if ((S_ISDIR((*parent)->mode) == 0) || (strchr(lastName, '/'))) {
return pn;
}
pn = (struct ProcDirEntry *)malloc(sizeof(struct ProcDirEntry));
if (pn == NULL) {
return NULL;
}
if ((mode & S_IALLUGO) == 0) {
mode |= S_IRUSR | S_IRGRP | S_IROTH;
}
(void)memset_s(pn, sizeof(struct ProcDirEntry), 0, sizeof(struct ProcDirEntry));
pn->nameLen = strlen(lastName);
pn->mode = mode;
ret = memcpy_s(pn->name, sizeof(pn->name), lastName, strlen(lastName) + 1);
if (ret != EOK) {
free(pn);
return NULL;
}
pn->pf = (struct ProcFile *)malloc(sizeof(struct ProcFile));
if (pn->pf == NULL) {
free(pn);
return NULL;
}
(void)memset_s(pn->pf, sizeof(struct ProcFile), 0, sizeof(struct ProcFile));
pn->pf->pPDE = pn;
ret = memcpy_s(pn->pf->name, sizeof(pn->pf->name), pn->name, pn->nameLen + 1);
if (ret != EOK) {
free(pn->pf);
free(pn);
return NULL;
}
atomic_set(&pn->count, 1);
spin_lock_init(&pn->pdeUnloadLock);
return pn;
}
static int ProcAddNode(struct ProcDirEntry *parent, struct ProcDirEntry *pn)
{
struct ProcDirEntry *temp = NULL;
if (parent == NULL) {
PRINT_ERR("%s(): parent is NULL", __FUNCTION__);
return -EINVAL;
}
if (pn->parent != NULL) {
PRINT_ERR("%s(): node already has a parent", __FUNCTION__);
return -EINVAL;
}
if (S_ISDIR(parent->mode) == 0) {
PRINT_ERR("%s(): parent is not a directory", __FUNCTION__);
return -EINVAL;
}
spin_lock(&procfsLock);
temp = ProcFindNode(parent, pn->name);
if (temp != NULL) {
PRINT_ERR("Error!ProcDirEntry '%s/%s' already registered\n", parent->name, pn->name);
spin_unlock(&procfsLock);
return -EEXIST;
}
pn->parent = parent;
pn->next = parent->subdir;
parent->subdir = pn;
spin_unlock(&procfsLock);
return 0;
}
static void ProcDetachNode(struct ProcDirEntry *pn)
{
struct ProcDirEntry *parent = pn->parent;
struct ProcDirEntry **iter = NULL;
if (parent == NULL) {
PRINT_ERR("%s(): node has no parent", __FUNCTION__);
return;
}
iter = &parent->subdir;
while (*iter != NULL) {
if (*iter == pn) {
*iter = pn->next;
break;
}
iter = &(*iter)->next;
}
pn->parent = NULL;
}
static struct ProcDirEntry *ProcCreateDir(struct ProcDirEntry *parent, const char *name,
const struct ProcFileOperations *procFileOps, mode_t mode)
{
struct ProcDirEntry *pn = NULL;
int ret;
pn = ProcAllocNode(&parent, name, S_IFDIR | mode);
if (pn == NULL) {
return pn;
}
pn->procFileOps = procFileOps;
pn->type = VNODE_TYPE_DIR;
ret = ProcAddNode(parent, pn);
if (ret != 0) {
free(pn->pf);
free(pn);
return NULL;
}
return pn;
}
static struct ProcDirEntry *ProcCreateFile(struct ProcDirEntry *parent, const char *name,
const struct ProcFileOperations *procFileOps, mode_t mode)
{
struct ProcDirEntry *pn = NULL;
int ret;
pn = ProcAllocNode(&parent, name, S_IFREG | mode);
if (pn == NULL) {
return pn;
}
pn->procFileOps = procFileOps;
pn->type = VNODE_TYPE_REG;
ret = ProcAddNode(parent, pn);
if (ret != 0) {
free(pn->pf);
free(pn);
return NULL;
}
return pn;
}
struct ProcDirEntry *CreateProcEntry(const char *name, mode_t mode, struct ProcDirEntry *parent)
{
struct ProcDirEntry *pde = NULL;
if (S_ISDIR(mode)) {
pde = ProcCreateDir(parent, name, NULL, mode);
} else {
pde = ProcCreateFile(parent, name, NULL, mode);
}
return pde;
}
static void FreeProcEntry(struct ProcDirEntry *entry)
{
if (entry == NULL) {
return;
}
if (entry->pf != NULL) {
free(entry->pf);
entry->pf = NULL;
}
free(entry);
}
void ProcFreeEntry(struct ProcDirEntry *pn)
{
if (atomic_dec_and_test(&pn->count)) {
FreeProcEntry(pn);
}
}
static void RemoveProcEntryTravalsal(struct ProcDirEntry *pn)
{
if (pn == NULL) {
return;
}
RemoveProcEntryTravalsal(pn->next);
RemoveProcEntryTravalsal(pn->subdir);
ProcFreeEntry(pn);
}
void RemoveProcEntry(const char *name, struct ProcDirEntry *parent)
{
struct ProcDirEntry *pn = NULL;
const char *lastName = name;
if ((name == NULL) || (strlen(name) == 0) || (procfsInit == false)) {
return;
}
if (CheckProcName(name, &parent, &lastName) != 0) {
return;
}
spin_lock(&procfsLock);
pn = ProcFindNode(parent, lastName);
if (pn == NULL) {
PRINT_ERR("Error:name '%s' not found!\n", name);
spin_unlock(&procfsLock);
return;
}
ProcDetachNode(pn);
spin_unlock(&procfsLock);
RemoveProcEntryTravalsal(pn->subdir);
ProcFreeEntry(pn);
}
struct ProcDirEntry *ProcMkdirMode(const char *name, mode_t mode, struct ProcDirEntry *parent)
{
return ProcCreateDir(parent, name, NULL, mode);
}
struct ProcDirEntry *ProcMkdir(const char *name, struct ProcDirEntry *parent)
{
return ProcCreateDir(parent, name, NULL, 0);
}
struct ProcDirEntry *ProcCreateData(const char *name, mode_t mode, struct ProcDirEntry *parent,
const struct ProcFileOperations *procFileOps, void *data)
{
struct ProcDirEntry *pde = CreateProcEntry(name, mode, parent);
if (pde != NULL) {
if (procFileOps != NULL) {
pde->procFileOps = procFileOps;
}
pde->data = data;
}
return pde;
}
struct ProcDirEntry *ProcCreate(const char *name, mode_t mode, struct ProcDirEntry *parent,
const struct ProcFileOperations *procFileOps)
{
return ProcCreateData(name, mode, parent, procFileOps, NULL);
}
int ProcStat(const char *file, struct ProcStat *buf)
{
struct ProcDirEntry *pn = NULL;
int len = sizeof(buf->name);
int ret;
pn = ProcFindEntry(file);
if (pn == NULL) {
return ENOENT;
}
ret = strncpy_s(buf->name, len, pn->name, len - 1);
if (ret != EOK) {
return ENAMETOOLONG;
}
buf->name[len - 1] = '\0';
buf->stMode = pn->mode;
buf->pPDE = pn;
return 0;
}
static int GetNextDir(struct ProcDirEntry *pn, void *buf, size_t len)
{
char *buff = (char *)buf;
if (pn->pdirCurrent == NULL) {
*buff = '\0';
return -ENOENT;
}
int namelen = pn->pdirCurrent->nameLen;
int ret = memcpy_s(buff, len, pn->pdirCurrent->name, namelen);
if (ret != EOK) {
return -ENAMETOOLONG;
}
pn->pdirCurrent = pn->pdirCurrent->next;
pn->pf->fPos++;
return ENOERR;
}
int ProcOpen(struct ProcFile *procFile)
{
if (procFile == NULL) {
return PROC_ERROR;
}
if (procFile->sbuf != NULL) {
return OK;
}
struct SeqBuf *buf = LosBufCreat();
if (buf == NULL) {
return PROC_ERROR;
}
procFile->sbuf = buf;
return OK;
}
static int ProcRead(struct ProcDirEntry *pde, char *buf, size_t len)
{
if (pde == NULL || pde->pf == NULL) {
return PROC_ERROR;
}
struct ProcFile *procFile = pde->pf;
struct SeqBuf *sb = procFile->sbuf;
if (sb->buf == NULL) {
// only read once to build the storage buffer
if (pde->procFileOps->read(sb, NULL) != 0) {
return PROC_ERROR;
}
}
size_t realLen;
loff_t pos = procFile->fPos;
if ((pos >= sb->count) || (len == 0)) {
/* there's no data or at the file tail. */
realLen = 0;
} else {
realLen = MIN((sb->count - pos), MIN(len, INT_MAX));
if (LOS_CopyFromKernel(buf, len, sb->buf + pos, realLen) != 0) {
return PROC_ERROR;
}
procFile->fPos = pos + realLen;
}
return (ssize_t)realLen;
}
struct ProcDirEntry *OpenProcFile(const char *fileName, int flags, ...)
{
unsigned int intSave;
struct ProcDirEntry *pn = ProcFindEntry(fileName);
if (pn == NULL) {
return NULL;
}
SCHEDULER_LOCK(intSave);
if (S_ISREG(pn->mode) && (pn->count != 1)) {
SCHEDULER_UNLOCK(intSave);
return NULL;
}
pn->flags = (unsigned int)(pn->flags) | (unsigned int)flags;
atomic_set(&pn->count, PROC_INUSE);
SCHEDULER_UNLOCK(intSave);
if (ProcOpen(pn->pf) != OK) {
return NULL;
}
if (S_ISREG(pn->mode) && (pn->procFileOps != NULL) && (pn->procFileOps->open != NULL)) {
(void)pn->procFileOps->open((struct Vnode *)pn, pn->pf);
}
if (S_ISDIR(pn->mode)) {
pn->pdirCurrent = pn->subdir;
pn->pf->fPos = 0;
}
return pn;
}
int ReadProcFile(struct ProcDirEntry *pde, void *buf, size_t len)
{
int result = -EPERM;
if (pde == NULL) {
return result;
}
if (S_ISREG(pde->mode)) {
if ((pde->procFileOps != NULL) && (pde->procFileOps->read != NULL)) {
result = ProcRead(pde, (char *)buf, len);
}
} else if (S_ISDIR(pde->mode)) {
result = GetNextDir(pde, buf, len);
}
return result;
}
int WriteProcFile(struct ProcDirEntry *pde, const void *buf, size_t len)
{
int result = -EPERM;
if (pde == NULL) {
return result;
}
if (S_ISDIR(pde->mode)) {
return -EISDIR;
}
spin_lock(&procfsLock);
if ((pde->procFileOps != NULL) && (pde->procFileOps->write != NULL)) {
result = pde->procFileOps->write(pde->pf, (const char *)buf, len, &(pde->pf->fPos));
}
spin_unlock(&procfsLock);
return result;
}
loff_t LseekProcFile(struct ProcDirEntry *pde, loff_t offset, int whence)
{
if (pde == NULL || pde->pf == NULL) {
return PROC_ERROR;
}
struct ProcFile *procFile = pde->pf;
loff_t result = -EINVAL;
switch (whence) {
case SEEK_CUR:
result = procFile->fPos + offset;
break;
case SEEK_SET:
result = offset;
break;
default:
break;
}
if (result >= 0) {
procFile->fPos = result;
}
return result;
}
int LseekDirProcFile(struct ProcDirEntry *pde, off_t *pos, int whence)
{
/* Only allow SEEK_SET to zero */
if ((whence != SEEK_SET) || (*pos != 0)) {
return EINVAL;
}
pde->pdirCurrent = pde->subdir;
pde->pf->fPos = 0;
return ENOERR;
}
int CloseProcFile(struct ProcDirEntry *pde)
{
int result = 0;
if (pde == NULL) {
return -EPERM;
}
pde->pf->fPos = 0;
atomic_set(&pde->count, 1);
if (S_ISDIR(pde->mode)) {
pde->pdirCurrent = pde->subdir;
}
if ((pde->procFileOps != NULL) && (pde->procFileOps->release != NULL)) {
result = pde->procFileOps->release((struct Vnode *)pde, pde->pf);
}
LosBufRelease(pde->pf->sbuf);
pde->pf->sbuf = NULL;
if (pde->parent == NULL) {
FreeProcEntry(pde);
}
return result;
}
struct ProcDirEntry *GetProcRootEntry(void)
{
return &g_procRootDirEntry;
}