diff options
Diffstat (limited to 'include/linux/seq_file.h')
| -rw-r--r-- | include/linux/seq_file.h | 310 |
1 files changed, 310 insertions, 0 deletions
diff --git a/include/linux/seq_file.h b/include/linux/seq_file.h new file mode 100644 index 000000000..386ab580b --- /dev/null +++ b/include/linux/seq_file.h @@ -0,0 +1,310 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _LINUX_SEQ_FILE_H +#define _LINUX_SEQ_FILE_H + +#include <linux/types.h> +#include <linux/string.h> +#include <linux/string_helpers.h> +#include <linux/bug.h> +#include <linux/mutex.h> +#include <linux/cpumask.h> +#include <linux/nodemask.h> +#include <linux/fs.h> +#include <linux/cred.h> + +struct seq_operations; + +struct seq_file { + char *buf; + size_t size; + size_t from; + size_t count; + size_t pad_until; + loff_t index; + loff_t read_pos; + struct mutex lock; + const struct seq_operations *op; + int poll_event; + const struct file *file; + void *private; +}; + +struct seq_operations { + void * (*start) (struct seq_file *m, loff_t *pos); + void (*stop) (struct seq_file *m, void *v); + void * (*next) (struct seq_file *m, void *v, loff_t *pos); + int (*show) (struct seq_file *m, void *v); +}; + +#define SEQ_SKIP 1 + +/** + * seq_has_overflowed - check if the buffer has overflowed + * @m: the seq_file handle + * + * seq_files have a buffer which may overflow. When this happens a larger + * buffer is reallocated and all the data will be printed again. + * The overflow state is true when m->count == m->size. + * + * Returns true if the buffer received more than it can hold. + */ +static inline bool seq_has_overflowed(struct seq_file *m) +{ + return m->count == m->size; +} + +/** + * seq_get_buf - get buffer to write arbitrary data to + * @m: the seq_file handle + * @bufp: the beginning of the buffer is stored here + * + * Return the number of bytes available in the buffer, or zero if + * there's no space. + */ +static inline size_t seq_get_buf(struct seq_file *m, char **bufp) +{ + BUG_ON(m->count > m->size); + if (m->count < m->size) + *bufp = m->buf + m->count; + else + *bufp = NULL; + + return m->size - m->count; +} + +/** + * seq_commit - commit data to the buffer + * @m: the seq_file handle + * @num: the number of bytes to commit + * + * Commit @num bytes of data written to a buffer previously acquired + * by seq_buf_get. To signal an error condition, or that the data + * didn't fit in the available space, pass a negative @num value. + */ +static inline void seq_commit(struct seq_file *m, int num) +{ + if (num < 0) { + m->count = m->size; + } else { + BUG_ON(m->count + num > m->size); + m->count += num; + } +} + +/** + * seq_setwidth - set padding width + * @m: the seq_file handle + * @size: the max number of bytes to pad. + * + * Call seq_setwidth() for setting max width, then call seq_printf() etc. and + * finally call seq_pad() to pad the remaining bytes. + */ +static inline void seq_setwidth(struct seq_file *m, size_t size) +{ + m->pad_until = m->count + size; +} +void seq_pad(struct seq_file *m, char c); + +char *mangle_path(char *s, const char *p, const char *esc); +int seq_open(struct file *, const struct seq_operations *); +ssize_t seq_read(struct file *, char __user *, size_t, loff_t *); +ssize_t seq_read_iter(struct kiocb *iocb, struct iov_iter *iter); +loff_t seq_lseek(struct file *, loff_t, int); +int seq_release(struct inode *, struct file *); +int seq_write(struct seq_file *seq, const void *data, size_t len); + +__printf(2, 0) +void seq_vprintf(struct seq_file *m, const char *fmt, va_list args); +__printf(2, 3) +void seq_printf(struct seq_file *m, const char *fmt, ...); +void seq_putc(struct seq_file *m, char c); +void seq_puts(struct seq_file *m, const char *s); +void seq_put_decimal_ull_width(struct seq_file *m, const char *delimiter, + unsigned long long num, unsigned int width); +void seq_put_decimal_ull(struct seq_file *m, const char *delimiter, + unsigned long long num); +void seq_put_decimal_ll(struct seq_file *m, const char *delimiter, long long num); +void seq_put_hex_ll(struct seq_file *m, const char *delimiter, + unsigned long long v, unsigned int width); + +void seq_escape_mem(struct seq_file *m, const char *src, size_t len, + unsigned int flags, const char *esc); + +static inline void seq_escape_str(struct seq_file *m, const char *src, + unsigned int flags, const char *esc) +{ + seq_escape_mem(m, src, strlen(src), flags, esc); +} + +/** + * seq_escape - print string into buffer, escaping some characters + * @m: target buffer + * @s: NULL-terminated string + * @esc: set of characters that need escaping + * + * Puts string into buffer, replacing each occurrence of character from + * @esc with usual octal escape. + * + * Use seq_has_overflowed() to check for errors. + */ +static inline void seq_escape(struct seq_file *m, const char *s, const char *esc) +{ + seq_escape_str(m, s, ESCAPE_OCTAL, esc); +} + +void seq_hex_dump(struct seq_file *m, const char *prefix_str, int prefix_type, + int rowsize, int groupsize, const void *buf, size_t len, + bool ascii); + +int seq_path(struct seq_file *, const struct path *, const char *); +int seq_file_path(struct seq_file *, struct file *, const char *); +int seq_dentry(struct seq_file *, struct dentry *, const char *); +int seq_path_root(struct seq_file *m, const struct path *path, + const struct path *root, const char *esc); + +void *single_start(struct seq_file *, loff_t *); +int single_open(struct file *, int (*)(struct seq_file *, void *), void *); +int single_open_size(struct file *, int (*)(struct seq_file *, void *), void *, size_t); +int single_release(struct inode *, struct file *); +void *__seq_open_private(struct file *, const struct seq_operations *, int); +int seq_open_private(struct file *, const struct seq_operations *, int); +int seq_release_private(struct inode *, struct file *); + +#ifdef CONFIG_BINARY_PRINTF +void seq_bprintf(struct seq_file *m, const char *f, const u32 *binary); +#endif + +#define DEFINE_SEQ_ATTRIBUTE(__name) \ +static int __name ## _open(struct inode *inode, struct file *file) \ +{ \ + int ret = seq_open(file, &__name ## _sops); \ + if (!ret && inode->i_private) { \ + struct seq_file *seq_f = file->private_data; \ + seq_f->private = inode->i_private; \ + } \ + return ret; \ +} \ + \ +static const struct file_operations __name ## _fops = { \ + .owner = THIS_MODULE, \ + .open = __name ## _open, \ + .read = seq_read, \ + .llseek = seq_lseek, \ + .release = seq_release, \ +} + +#define DEFINE_SHOW_ATTRIBUTE(__name) \ +static int __name ## _open(struct inode *inode, struct file *file) \ +{ \ + return single_open(file, __name ## _show, inode->i_private); \ +} \ + \ +static const struct file_operations __name ## _fops = { \ + .owner = THIS_MODULE, \ + .open = __name ## _open, \ + .read = seq_read, \ + .llseek = seq_lseek, \ + .release = single_release, \ +} + +#define DEFINE_PROC_SHOW_ATTRIBUTE(__name) \ +static int __name ## _open(struct inode *inode, struct file *file) \ +{ \ + return single_open(file, __name ## _show, pde_data(inode)); \ +} \ + \ +static const struct proc_ops __name ## _proc_ops = { \ + .proc_open = __name ## _open, \ + .proc_read = seq_read, \ + .proc_lseek = seq_lseek, \ + .proc_release = single_release, \ +} + +static inline struct user_namespace *seq_user_ns(struct seq_file *seq) +{ +#ifdef CONFIG_USER_NS + return seq->file->f_cred->user_ns; +#else + extern struct user_namespace init_user_ns; + return &init_user_ns; +#endif +} + +/** + * seq_show_options - display mount options with appropriate escapes. + * @m: the seq_file handle + * @name: the mount option name + * @value: the mount option name's value, can be NULL + */ +static inline void seq_show_option(struct seq_file *m, const char *name, + const char *value) +{ + seq_putc(m, ','); + seq_escape(m, name, ",= \t\n\\"); + if (value) { + seq_putc(m, '='); + seq_escape(m, value, ", \t\n\\"); + } +} + +/** + * seq_show_option_n - display mount options with appropriate escapes + * where @value must be a specific length (i.e. + * not NUL-terminated). + * @m: the seq_file handle + * @name: the mount option name + * @value: the mount option name's value, cannot be NULL + * @length: the exact length of @value to display, must be constant expression + * + * This is a macro since this uses "length" to define the size of the + * stack buffer. + */ +#define seq_show_option_n(m, name, value, length) { \ + char val_buf[length + 1]; \ + memcpy(val_buf, value, length); \ + val_buf[length] = '\0'; \ + seq_show_option(m, name, val_buf); \ +} + +#define SEQ_START_TOKEN ((void *)1) +/* + * Helpers for iteration over list_head-s in seq_files + */ + +extern struct list_head *seq_list_start(struct list_head *head, + loff_t pos); +extern struct list_head *seq_list_start_head(struct list_head *head, + loff_t pos); +extern struct list_head *seq_list_next(void *v, struct list_head *head, + loff_t *ppos); + +extern struct list_head *seq_list_start_rcu(struct list_head *head, loff_t pos); +extern struct list_head *seq_list_start_head_rcu(struct list_head *head, loff_t pos); +extern struct list_head *seq_list_next_rcu(void *v, struct list_head *head, loff_t *ppos); + +/* + * Helpers for iteration over hlist_head-s in seq_files + */ + +extern struct hlist_node *seq_hlist_start(struct hlist_head *head, + loff_t pos); +extern struct hlist_node *seq_hlist_start_head(struct hlist_head *head, + loff_t pos); +extern struct hlist_node *seq_hlist_next(void *v, struct hlist_head *head, + loff_t *ppos); + +extern struct hlist_node *seq_hlist_start_rcu(struct hlist_head *head, + loff_t pos); +extern struct hlist_node *seq_hlist_start_head_rcu(struct hlist_head *head, + loff_t pos); +extern struct hlist_node *seq_hlist_next_rcu(void *v, + struct hlist_head *head, + loff_t *ppos); + +/* Helpers for iterating over per-cpu hlist_head-s in seq_files */ +extern struct hlist_node *seq_hlist_start_percpu(struct hlist_head __percpu *head, int *cpu, loff_t pos); + +extern struct hlist_node *seq_hlist_next_percpu(void *v, struct hlist_head __percpu *head, int *cpu, loff_t *pos); + +void seq_file_init(void); +#endif |