// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Information interface for ALSA driver
* Copyright (c) by Jaroslav Kysela <[email protected]>
*/
#include <linux/init.h>
#include <linux/time.h>
#include <linux/mm.h>
#include <linux/slab.h>
#include <linux/string.h>
#include <linux/module.h>
#include <sound/core.h>
#include <sound/minors.h>
#include <sound/info.h>
#include <linux/utsname.h>
#include <linux/proc_fs.h>
#include <linux/mutex.h>
int snd_info_check_reserved_words(const char *str)
{
static const char * const reserved[] =
{
"version",
"meminfo",
"memdebug",
"detect",
"devices",
"oss",
"cards",
"timers",
"synth",
"pcm",
"seq",
NULL
};
const char * const *xstr = reserved;
while (*xstr) {
if (!strcmp(*xstr, str))
return 0;
xstr++;
}
if (!strncmp(str, "card", 4))
return 0;
return 1;
}
static DEFINE_MUTEX(info_mutex);
struct snd_info_private_data {
struct snd_info_buffer *rbuffer;
struct snd_info_buffer *wbuffer;
struct snd_info_entry *entry;
void *file_private_data;
};
static int snd_info_version_init(void);
static void snd_info_clear_entries(struct snd_info_entry *entry);
/*
*/
static struct snd_info_entry *snd_proc_root;
struct snd_info_entry *snd_seq_root;
EXPORT_SYMBOL(snd_seq_root);
#ifdef CONFIG_SND_OSSEMUL
struct snd_info_entry *snd_oss_root;
#endif
static int alloc_info_private(struct snd_info_entry *entry,
struct snd_info_private_data **ret)
{
struct snd_info_private_data *data;
if (!entry || !entry->p)
return -ENODEV;
if (!try_module_get(entry->module))
return -EFAULT;
data = kzalloc(sizeof(*data), GFP_KERNEL);
if (!data) {
module_put(entry->module);
return -ENOMEM;
}
data->entry = entry;
*ret = data;
return 0;
}
static bool valid_pos(loff_t pos, size_t count)
{
if (pos < 0 || (long) pos != pos || (ssize_t) count < 0)
return false;
if ((unsigned long) pos + (unsigned long) count < (unsigned long) pos)
return false;
return true;
}
/*
* file ops for binary proc files
*/
static loff_t snd_info_entry_llseek(struct file *file, loff_t offset, int orig)
{
struct snd_info_private_data *data;
struct snd_info_entry *entry;
loff_t size;
data = file->private_data;
entry = data->entry;
guard(mutex)(&entry->access);
if (entry->c.ops->llseek)
return entry->c.ops->llseek(entry,
data->file_private_data,
file, offset, orig);
size = entry->size;
switch (orig) {
case SEEK_SET:
break;
case SEEK_CUR:
offset += file->f_pos;
break;
case SEEK_END:
if (!size)
return -EINVAL;
offset += size;
break;
default:
return -EINVAL;
}
if (offset < 0)
return -EINVAL;
if (size && offset > size)
offset = size;
file->f_pos = offset;
return offset;
}
static ssize_t snd_info_entry_read(struct file *file, char __user *buffer,
size_t count, loff_t * offset)
{
struct snd_info_private_data *data = file->private_data;
struct snd_info_entry *entry = data->entry;
size_t size;
loff_t pos;
pos = *offset;
if (!valid_pos(pos, count))
return -EIO;
if (pos >= entry->size)
return 0;
size = entry->size - pos;
size = min(count, size);
size = entry->c.ops->read(entry, data->file_private_data,
file, buffer, size, pos);
if ((ssize_t) size > 0)
*offset = pos + size;
return size;
}
static ssize_t snd_info_entry_write(struct file *file, const char __user *buffer,
size_t count, loff_t * offset)
{
struct snd_info_private_data *data = file->private_data;
struct snd_info_entry *entry = data->entry;
ssize_t size = 0;
loff_t pos;
pos = *offset;
if (!valid_pos(pos, count))
return -EIO;
if (count > 0) {
size_t maxsize = entry->size - pos;
count = min(count, maxsize);
size = entry->c.ops->write(entry, data->file_private_data,
file, buffer, count, pos);
}
if (size > 0)
*offset = pos + size;
return size;
}
static __poll_t snd_info_entry_poll(struct file *file, poll_table *wait)
{
struct snd_info_private_data *data = file->private_data;
struct snd_info_entry *entry = data->entry;
__poll_t mask = 0;
if (entry->c.ops->poll)
return entry->c.ops->poll(entry,
data->file_private_data,
file, wait);
if (entry->c.ops->read)
mask |= EPOLLIN | EPOLLRDNORM;
if (entry->c.ops->write)
mask |= EPOLLOUT | EPOLLWRNORM;
return mask;
}
static long snd_info_entry_ioctl(struct file *file, unsigned int cmd,
unsigned long arg)
{
struct snd_info_private_data *data = file->private_data;
struct snd_info_entry *entry = data->entry;
if (!entry->c.ops->ioctl)
return -ENOTTY;
return entry->c.ops->ioctl(entry, data->file_private_data,
file, cmd, arg);
}
static int snd_info_entry_mmap(struct file *file, struct vm_area_struct *vma)
{
struct inode *inode = file_inode(file);
struct snd_info_private_data *data;
struct snd_info_entry *entry;
data = file->private_data;
if (data == NULL)
return 0;
entry = data->entry;
if (!entry->c.ops->mmap)
return -ENXIO;
return entry->c.ops->mmap(entry, data->file_private_data,
inode, file, vma);
}
static int snd_info_entry_open(struct inode *inode, struct file *file)
{
struct snd_info_entry *entry = pde_data(inode);
struct snd_info_private_data *data;
int mode, err;
guard(mutex)(&info_mutex);
err = alloc_info_private(entry, &data);
if (err < 0)
return err;
mode = file->f_flags & O_ACCMODE;
if (((mode == O_RDONLY || mode == O_RDWR) && !entry->c.ops->read) ||
((mode == O_WRONLY || mode == O_RDWR) && !entry->c.ops->write)) {
err = -ENODEV;
goto error;
}
if (entry->c.ops->open) {
err = entry->c.ops->open(entry, mode, &data->file_private_data);
if (err < 0)
goto error;
}
file->private_data = data;
return 0;
error:
kfree(data);
module_put(entry->module);
return err;
}
static int snd_info_entry_release(struct inode *inode, struct file *file)
{
struct snd_info_private_data *data = file->private_data;
struct snd_info_entry *entry = data->entry;
if (entry->c.ops->release)
entry->c.ops->release(entry, file->f_flags & O_ACCMODE,
data->file_private_data);
module_put(entry->module);
kfree(data);
return 0;
}
static const struct proc_ops snd_info_entry_operations =
{
.proc_lseek = snd_info_entry_llseek,
.proc_read = snd_info_entry_read,
.proc_write = snd_info_entry_write,
.proc_poll = snd_info_entry_poll,
.proc_ioctl = snd_info_entry_ioctl,
.proc_mmap = snd_info_entry_mmap,
.proc_open = snd_info_entry_open,
.proc_release = snd_info_entry_release,
};
/*
* file ops for text proc files
*/
static ssize_t snd_info_text_entry_write(struct file *file,
const char __user *buffer,
size_t count, loff_t *offset)
{
struct seq_file *m = file->private_data;
struct snd_info_private_data *data = m->private;
struct snd_info_entry *entry = data->entry;
struct snd_info_buffer *buf;
loff_t pos;
size_t next;
if (!entry->c.text.write)
return -EIO;
pos = *offset;
if (!valid_pos(pos, count))
return -EIO;
next = pos + count;
/* don't handle too large text inputs */
if (next > 16 * 1024)
return -EIO;
guard(mutex)(&entry->access);
buf = data->wbuffer;
if (!buf) {
data->wbuffer = buf = kzalloc(sizeof(*buf), GFP_KERNEL);
if (!buf)
return -ENOMEM;
}
if (next > buf->len) {
char *nbuf = kvzalloc(PAGE_ALIGN(next), GFP_KERNEL);
if (!nbuf)
return -ENOMEM;
kvfree(buf->buffer);
buf->buffer = nbuf;
buf->len = PAGE_ALIGN(next);
}
if (copy_from_user(buf->buffer + pos, buffer, count))
return -EFAULT;
buf->size = next;
*offset = next;
return count;
}
static int snd_info_seq_show(struct seq_file *seq, void *p)
{
struct snd_info_private_data *data = seq->private;
struct snd_info_entry *entry = data->entry;
if (!entry->c.text.read) {
return -EIO;
} else {
data->rbuffer->buffer = (char *)seq; /* XXX hack! */
entry->c.text.read(entry, data->rbuffer);
}
return 0;
}
static int snd_info_text_entry_open(struct inode *inode, struct file *file)
{
struct snd_info_entry *entry = pde_data(inode);
struct snd_info_private_data *data;
int err;
guard(mutex)(&info_mutex);
err = alloc_info_private(entry, &data);
if (err < 0)
return err;
data->rbuffer = kzalloc(sizeof(*data->rbuffer), GFP_KERNEL);
if (!data->rbuffer) {
err = -ENOMEM;
goto error;
}
if (entry->size)
err = single_open_size(file, snd_info_seq_show, data,
entry->size);
else
err = single_open(file, snd_info_seq_show, data);
if (err < 0)
goto error;
return 0;
error:
kfree(data->rbuffer);
kfree(data);
module_put(entry->module);
return err;
}
static int snd_info_text_entry_release(struct inode *inode, struct file *file)
{
struct seq_file *m = file->private_data;
struct snd_info_private_data *data = m->private;
struct snd_info_entry *entry = data->entry;
if (data->wbuffer && entry->c.text.write)
entry->c.text.write(entry, data->wbuffer);
single_release(inode, file);
kfree(data->rbuffer);
if (data->wbuffer) {
kvfree(data->wbuffer->buffer);
kfree(data->wbuffer);
}
module_put(entry->module);
kfree(data);
return 0;
}
static const struct proc_ops snd_info_text_entry_ops =
{
.proc_open = snd_info_text_entry_open,
.proc_release = snd_info_text_entry_release,
.proc_write = snd_info_text_entry_write,
.proc_lseek = seq_lseek,
.proc_read = seq_read,
};
static struct snd_info_entry *create_subdir(struct module *mod,
const char *name)
{
struct snd_info_entry *entry;
entry = snd_info_create_module_entry(mod, name, NULL);
if (!entry)
return NULL;
entry->mode = S_IFDIR | 0555;
if (snd_info_register(entry) < 0) {
snd_info_free_entry(entry);
return NULL;
}
return entry;
}
static struct snd_info_entry *
snd_info_create_entry(const char *name, struct snd_info_entry *parent,
struct module *module);
int __init snd_info_init(void)
{
snd_proc_root = snd_info_create_entry("asound", NULL, THIS_MODULE);
if (!snd_proc_root)
return -ENOMEM;
snd_proc_root->mode = S_IFDIR | 0555;
snd_proc_root->p = proc_mkdir("asound", NULL);
if (!snd_proc_root->p)
goto error;
#ifdef CONFIG_SND_OSSEMUL
snd_oss_root = create_subdir(THIS_MODULE, "oss");
if (!snd_oss_root)
goto error;
#endif
#if IS_ENABLED(CONFIG_SND_SEQUENCER)
snd_seq_root = create_subdir(THIS_MODULE, "seq");
if (!snd_seq_root)
goto error;
#endif
if (snd_info_version_init() < 0 ||
snd_minor_info_init() < 0 ||
snd_minor_info_oss_init() < 0 ||
snd_card_info_init() < 0 ||
snd_info_minor_register() < 0)
goto error;
return 0;
error:
snd_info_free_entry(snd_proc_root);
return -ENOMEM;
}
int __exit snd_info_done(void)
{
snd_info_free_entry(snd_proc_root);
return 0;
}
static void snd_card_id_read(struct snd_info_entry *entry,
struct snd_info_buffer *buffer)
{
struct snd_card *card = entry->private_data;
snd_iprintf(buffer, "%s\n", card->id);
}
/*
* create a card proc file
* called from init.c
*/
int snd_info_card_create(struct snd_card *card)
{
char str[8];
struct snd_info_entry *entry;
if (snd_BUG_ON(!card))
return -ENXIO;
sprintf(str, "card%i", card->number);
entry = create_subdir(card->module, str);
if (!entry)
return -ENOMEM;
card->proc_root = entry;
return snd_card_ro_proc_new(card, "id", card, snd_card_id_read);
}
/*
* register the card proc file
* called from init.c
* can be called multiple times for reinitialization
*/
int snd_info_card_register(struct snd_card *card)
{
struct proc_dir_entry *p;
int err;
if (snd_BUG_ON(!card))
return -ENXIO;
err = snd_info_register(card->proc_root);
if (err < 0)
return err;
if (!strcmp(card->id, card->proc_root->name))
return 0;
if (card->proc_root_link)
return 0;
p = proc_symlink(card->id, snd_proc_root->p, card->proc_root->name);
if (!p)
return -ENOMEM;
card->proc_root_link = p;
return 0;
}
/*
* called on card->id change
*/
void snd_info_card_id_change(struct snd_card *card)
{
guard(mutex)(&info_mutex);
if (card->proc_root_link) {
proc_remove(card->proc_root_link);
card->proc_root_link = NULL;
}
if (strcmp(card->id, card->proc_root->name))
card->proc_root_link = proc_symlink(card->id,
snd_proc_root->p,
card->proc_root->name);
}
/*
* de-register the card proc file
* called from init.c
*/
void snd_info_card_disconnect(struct snd_card *card)
{
if (!card)
return;
proc_remove(card->proc_root_link);
if (card->proc_root)
proc_remove(card->proc_root->p);
guard(mutex)(&info_mutex);
if (card->proc_root)
snd_info_clear_entries(card->proc_root);
card->proc_root_link = NULL;
card->proc_root = NULL;
}
/*
* release the card proc file resources
* called from init.c
*/
int snd_info_card_free(struct snd_card *card)
{
if (!card)
return 0;
snd_info_free_entry(card->proc_root);
card->proc_root = NULL;
return 0;
}
/**
* snd_info_get_line - read one line from the procfs buffer
* @buffer: the procfs buffer
* @line: the buffer to store
* @len: the max. buffer size
*
* Reads one line from the buffer and stores the string.
*
* Return: Zero if successful, or 1 if error or EOF.
*/
int snd_info_get_line(struct snd_info_buffer *buffer, char *line, int len)
{
int c;
if (snd_BUG_ON(!buffer))
return 1;
if (!buffer->buffer)
return 1;
if (len <= 0 || buffer->stop || buffer->error)
return 1;
while (!buffer->stop) {
c = buffer->buffer[buffer->curr++];
if (buffer->curr >= buffer->size)
buffer->stop = 1;
if (c == '\n')
break;
if (len > 1) {
len--;
*line++ = c;
}
}
*line = '\0';
return 0;
}
EXPORT_SYMBOL(snd_info_get_line);
/**
* snd_info_get_str - parse a string token
* @dest: the buffer to store the string token
* @src: the original string
* @len: the max. length of token - 1
*
* Parses the original string and copy a token to the given
* string buffer.
*
* Return: The updated pointer of the original string so that
* it can be used for the next call.
*/
const char *snd_info_get_str(char *dest, const char *src, int len)
{
int c;
while (*src == ' ' || *src == '\t')
src++;
if (*src == '"' || *src == '\'') {
c = *src++;
while (--len > 0 && *src && *src != c) {
*dest++ = *src++;
}
if (*src == c)
src++;
} else {
while (--len > 0 && *src && *src != ' ' && *src != '\t') {
*dest++ = *src++;
}
}
*dest = 0;
while (*src == ' ' || *src == '\t')
src++;
return src;
}
EXPORT_SYMBOL(snd_info_get_str);
/*
* snd_info_create_entry - create an info entry
* @name: the proc file name
* @parent: the parent directory
*
* Creates an info entry with the given file name and initializes as
* the default state.
*
* Usually called from other functions such as
* snd_info_create_card_entry().
*
* Return: The pointer of the new instance, or %NULL on failure.
*/
static struct snd_info_entry *
snd_info_create_entry(const char *name, struct snd_info_entry *parent,
struct module *module)
{
struct snd_info_entry *entry;
entry = kzalloc(sizeof(*entry), GFP_KERNEL);
if (entry == NULL)
return NULL;
entry->name = kstrdup(name, GFP_KERNEL);
if (entry->name == NULL) {
kfree(entry);
return NULL;
}
entry->mode = S_IFREG | 0444;
entry->content = SNDRV_INFO_CONTENT_TEXT;
mutex_init(&entry->access);
INIT_LIST_HEAD(&entry->children);
INIT_LIST_HEAD(&entry->list);
entry->parent = parent;
entry->module = module;
if (parent) {
guard(mutex)(&parent->access);
list_add_tail(&entry->list, &parent->children);
}
return entry;
}
/**
* snd_info_create_module_entry - create an info entry for the given module
* @module: the module pointer
* @name: the file name
* @parent: the parent directory
*
* Creates a new info entry and assigns it to the given module.
*
* Return: The pointer of the new instance, or %NULL on failure.
*/
struct snd_info_entry *snd_info_create_module_entry(struct module * module,
const char *name,
struct snd_info_entry *parent)
{
if (!parent)
parent = snd_proc_root;
return snd_info_create_entry(name, parent, module);
}
EXPORT_SYMBOL(snd_info_create_module_entry);
/**
* snd_info_create_card_entry - create an info entry for the given card
* @card: the card instance
* @name: the file name
* @parent: the parent directory
*
* Creates a new info entry and assigns it to the given card.
*
* Return: The pointer of the new instance, or %NULL on failure.
*/
struct snd_info_entry *snd_info_create_card_entry(struct snd_card *card,
const char *name,
struct snd_info_entry * parent)
{
if (!parent)
parent = card->proc_root;
return snd_info_create_entry(name, parent, card->module);
}
EXPORT_SYMBOL(snd_info_create_card_entry);
static void snd_info_clear_entries(struct snd_info_entry *entry)
{
struct snd_info_entry *p;
if (!entry->p)
return;
list_for_each_entry(p, &entry->children, list)
snd_info_clear_entries(p);
entry->p = NULL;
}
/**
* snd_info_free_entry - release the info entry
* @entry: the info entry
*
* Releases the info entry.
*/
void snd_info_free_entry(struct snd_info_entry * entry)
{
struct snd_info_entry *p, *n;
if (!entry)
return;
if (entry->p) {
proc_remove(entry->p);
guard(mutex)(&info_mutex);
snd_info_clear_entries(entry);
}
/* free all children at first */
list_for_each_entry_safe(p, n, &entry->children, list)
snd_info_free_entry(p);
p = entry->parent;
if (p) {
guard(mutex)(&p->access);
list_del(&entry->list);
}
kfree(entry->name);
if (entry->private_free)
entry->private_free(entry);
kfree(entry);
}
EXPORT_SYMBOL(snd_info_free_entry);
static int __snd_info_register(struct snd_info_entry *entry)
{
struct proc_dir_entry *root, *p = NULL;
if (snd_BUG_ON(!entry))
return -ENXIO;
root = entry->parent == NULL ? snd_proc_root->p : entry->parent->p;
guard(mutex)(&info_mutex);
if (entry->p || !root)
return 0;
if (S_ISDIR(entry->mode)) {
p = proc_mkdir_mode(entry->name, entry->mode, root);
if (!p)
return -ENOMEM;
} else {
const struct proc_ops *ops;
if (entry->content == SNDRV_INFO_CONTENT_DATA)
ops = &snd_info_entry_operations;
else
ops = &snd_info_text_entry_ops;
p = proc_create_data(entry->name, entry->mode, root,
ops, entry);
if (!p)
return -ENOMEM;
proc_set_size(p, entry->size);
}
entry->p = p;
return 0;
}
/**
* snd_info_register - register the info entry
* @entry: the info entry
*
* Registers the proc info entry.
* The all children entries are registered recursively.
*
* Return: Zero if successful, or a negative error code on failure.
*/
int snd_info_register(struct snd_info_entry *entry)
{
struct snd_info_entry *p;
int err;
if (!entry->p) {
err = __snd_info_register(entry);
if (err < 0)
return err;
}
list_for_each_entry(p, &entry->children, list) {
err = snd_info_register(p);
if (err < 0)
return err;
}
return 0;
}
EXPORT_SYMBOL(snd_info_register);
/**
* snd_card_rw_proc_new - Create a read/write text proc file entry for the card
* @card: the card instance
* @name: the file name
* @private_data: the arbitrary private data
* @read: the read callback
* @write: the write callback, NULL for read-only
*
* This proc file entry will be registered via snd_card_register() call, and
* it will be removed automatically at the card removal, too.
*
* Return: zero if successful, or a negative error code
*/
int snd_card_rw_proc_new(struct snd_card *card, const char *name,
void *private_data,
void (*read)(struct snd_info_entry *,
struct snd_info_buffer *),
void (*write)(struct snd_info_entry *entry,
struct snd_info_buffer *buffer))
{
struct snd_info_entry *entry;
entry = snd_info_create_card_entry(card, name, card->proc_root);
if (!entry)
return -ENOMEM;
snd_info_set_text_ops(entry, private_data, read);
if (write) {
entry->mode |= 0200;
entry->c.text.write = write;
}
return 0;
}
EXPORT_SYMBOL_GPL(snd_card_rw_proc_new);
/*
*/
static void snd_info_version_read(struct snd_info_entry *entry, struct snd_info_buffer *buffer)
{
snd_iprintf(buffer,
"Advanced Linux Sound Architecture Driver Version k%s.\n",
init_utsname()->release);
}
static int __init snd_info_version_init(void)
{
struct snd_info_entry *entry;
entry = snd_info_create_module_entry(THIS_MODULE, "version", NULL);
if (entry == NULL)
return -ENOMEM;
entry->c.text.read = snd_info_version_read;
return snd_info_register(entry); /* freed in error path */
}
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