diff options
Diffstat (limited to 'sound/core/info.c')
-rw-r--r-- | sound/core/info.c | 919 |
1 files changed, 919 insertions, 0 deletions
diff --git a/sound/core/info.c b/sound/core/info.c new file mode 100644 index 000000000..ebae11b49 --- /dev/null +++ b/sound/core/info.c @@ -0,0 +1,919 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Information interface for ALSA driver + * Copyright (c) by Jaroslav Kysela <perex@perex.cz> + */ + +#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> +#include <stdarg.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 ret = -EINVAL, size; + + data = file->private_data; + entry = data->entry; + mutex_lock(&entry->access); + if (entry->c.ops->llseek) { + ret = entry->c.ops->llseek(entry, + data->file_private_data, + file, offset, orig); + goto out; + } + + size = entry->size; + switch (orig) { + case SEEK_SET: + break; + case SEEK_CUR: + offset += file->f_pos; + break; + case SEEK_END: + if (!size) + goto out; + offset += size; + break; + default: + goto out; + } + if (offset < 0) + goto out; + if (size && offset > size) + offset = size; + file->f_pos = offset; + ret = offset; + out: + mutex_unlock(&entry->access); + return ret; +} + +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; + + mutex_lock(&info_mutex); + err = alloc_info_private(entry, &data); + if (err < 0) + goto unlock; + + 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; + mutex_unlock(&info_mutex); + return 0; + + error: + kfree(data); + module_put(entry->module); + unlock: + mutex_unlock(&info_mutex); + 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; + int err = 0; + + 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; + mutex_lock(&entry->access); + buf = data->wbuffer; + if (!buf) { + data->wbuffer = buf = kzalloc(sizeof(*buf), GFP_KERNEL); + if (!buf) { + err = -ENOMEM; + goto error; + } + } + if (next > buf->len) { + char *nbuf = kvzalloc(PAGE_ALIGN(next), GFP_KERNEL); + if (!nbuf) { + err = -ENOMEM; + goto error; + } + kvfree(buf->buffer); + buf->buffer = nbuf; + buf->len = PAGE_ALIGN(next); + } + if (copy_from_user(buf->buffer + pos, buffer, count)) { + err = -EFAULT; + goto error; + } + buf->size = next; + error: + mutex_unlock(&entry->access); + if (err < 0) + return err; + *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; + + mutex_lock(&info_mutex); + err = alloc_info_private(entry, &data); + if (err < 0) + goto unlock; + + 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; + mutex_unlock(&info_mutex); + return 0; + + error: + kfree(data->rbuffer); + kfree(data); + module_put(entry->module); + unlock: + mutex_unlock(&info_mutex); + 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) +{ + mutex_lock(&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); + mutex_unlock(&info_mutex); +} + +/* + * 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); + + mutex_lock(&info_mutex); + if (card->proc_root) + snd_info_clear_entries(card->proc_root); + card->proc_root_link = NULL; + card->proc_root = NULL; + mutex_unlock(&info_mutex); +} + +/* + * 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) { + mutex_lock(&parent->access); + list_add_tail(&entry->list, &parent->children); + mutex_unlock(&parent->access); + } + 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); + mutex_lock(&info_mutex); + snd_info_clear_entries(entry); + mutex_unlock(&info_mutex); + } + + /* 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) { + mutex_lock(&p->access); + list_del(&entry->list); + mutex_unlock(&p->access); + } + 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; + mutex_lock(&info_mutex); + if (entry->p || !root) + goto unlock; + if (S_ISDIR(entry->mode)) { + p = proc_mkdir_mode(entry->name, entry->mode, root); + if (!p) { + mutex_unlock(&info_mutex); + 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) { + mutex_unlock(&info_mutex); + return -ENOMEM; + } + proc_set_size(p, entry->size); + } + entry->p = p; + unlock: + mutex_unlock(&info_mutex); + 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. + */ +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 */ +} |