[mirror_ubuntu-jammy-kernel.git] / include / linux / seq_file.h

/* 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/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(struct seq_file *m, const char *s, const char *esc);
void seq_escape_mem_ascii(struct seq_file *m, const char *src, size_t isz);

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);

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, inode->i_private);	\
}									\
									\
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.
 * @m: the seq_file handle
 * @name: the mount option name
 * @value: the mount option name's value, cannot be NULL
 * @length: the length of @value to display
 *
 * 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];			\
	strncpy(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);

/*
 * 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
Commit	Line	Data
b2441318	1	/* SPDX-License-Identifier: GPL-2.0 */
1da177e4 LT	2	#ifndef _LINUX_SEQ_FILE_H
1da177e4 LT	3	#define _LINUX_SEQ_FILE_H
1da177e4 LT	4
	5	#include <linux/types.h>
	6	#include <linux/string.h>
187f1882	7	#include <linux/bug.h>
0ac1759a	8	#include <linux/mutex.h>
50ac2d69 AD	9	#include <linux/cpumask.h>
50ac2d69 AD	10	#include <linux/nodemask.h>
34dbbcdb LT	11	#include <linux/fs.h>
34dbbcdb LT	12	#include <linux/cred.h>
1da177e4 LT	13
1da177e4 LT	14	struct seq_operations;
1da177e4 LT	15
	16	struct seq_file {
	17	char *buf;
	18	size_t size;
	19	size_t from;
	20	size_t count;
839cc2a9	21	size_t pad_until;
1da177e4	22	loff_t index;
8f19d472	23	loff_t read_pos;
0ac1759a	24	struct mutex lock;
15ad7cdc	25	const struct seq_operations *op;
f1514638	26	int poll_event;
34dbbcdb	27	const struct file *file;
1da177e4 LT	28	void *private;
	29	};
	30
	31	struct seq_operations {
	32	void * (start) (struct seq_file m, loff_t *pos);
	33	void (stop) (struct seq_file m, void *v);
	34	void * (next) (struct seq_file m, void v, loff_t pos);
	35	int (show) (struct seq_file m, void *v);
	36	};
	37
521b5d0c AV	38	#define SEQ_SKIP 1
521b5d0c AV	39
1f33c41c JP	40	/**
	41	* seq_has_overflowed - check if the buffer has overflowed
	42	* @m: the seq_file handle
	43	*
	44	* seq_files have a buffer which may overflow. When this happens a larger
	45	* buffer is reallocated and all the data will be printed again.
	46	* The overflow state is true when m->count == m->size.
	47	*
	48	* Returns true if the buffer received more than it can hold.
	49	*/
	50	static inline bool seq_has_overflowed(struct seq_file *m)
	51	{
	52	return m->count == m->size;
	53	}
	54
f8439806 MS	55	/**
	56	* seq_get_buf - get buffer to write arbitrary data to
	57	* @m: the seq_file handle
	58	* @bufp: the beginning of the buffer is stored here
	59	*
	60	* Return the number of bytes available in the buffer, or zero if
	61	* there's no space.
	62	*/
	63	static inline size_t seq_get_buf(struct seq_file m, char *bufp)
	64	{
	65	BUG_ON(m->count > m->size);
	66	if (m->count < m->size)
	67	*bufp = m->buf + m->count;
	68	else
	69	*bufp = NULL;
	70
	71	return m->size - m->count;
	72	}
	73
	74	/**
	75	* seq_commit - commit data to the buffer
	76	* @m: the seq_file handle
	77	* @num: the number of bytes to commit
	78	*
	79	* Commit @num bytes of data written to a buffer previously acquired
	80	* by seq_buf_get. To signal an error condition, or that the data
	81	* didn't fit in the available space, pass a negative @num value.
	82	*/
	83	static inline void seq_commit(struct seq_file *m, int num)
	84	{
	85	if (num < 0) {
	86	m->count = m->size;
	87	} else {
	88	BUG_ON(m->count + num > m->size);
	89	m->count += num;
	90	}
	91	}
	92
839cc2a9 TH	93	/**
	94	* seq_setwidth - set padding width
	95	* @m: the seq_file handle
	96	* @size: the max number of bytes to pad.
	97	*
	98	* Call seq_setwidth() for setting max width, then call seq_printf() etc. and
	99	* finally call seq_pad() to pad the remaining bytes.
	100	*/
	101	static inline void seq_setwidth(struct seq_file *m, size_t size)
	102	{
	103	m->pad_until = m->count + size;
	104	}
	105	void seq_pad(struct seq_file *m, char c);
	106
8c9379e9	107	char mangle_path(char s, const char p, const char esc);
15ad7cdc	108	int seq_open(struct file , const struct seq_operations );
1da177e4	109	ssize_t seq_read(struct file , char __user , size_t, loff_t *);
d4d50710	110	ssize_t seq_read_iter(struct kiocb iocb, struct iov_iter iter);
1da177e4 LT	111	loff_t seq_lseek(struct file *, loff_t, int);
1da177e4 LT	112	int seq_release(struct inode , struct file );
0b923606	113	int seq_write(struct seq_file seq, const void data, size_t len);
1da177e4	114
6798a8ca JP	115	__printf(2, 0)
	116	void seq_vprintf(struct seq_file m, const char fmt, va_list args);
	117	__printf(2, 3)
	118	void seq_printf(struct seq_file m, const char fmt, ...);
	119	void seq_putc(struct seq_file *m, char c);
	120	void seq_puts(struct seq_file m, const char s);
d1be35cb AV	121	void seq_put_decimal_ull_width(struct seq_file m, const char delimiter,
d1be35cb AV	122	unsigned long long num, unsigned int width);
75ba1d07	123	void seq_put_decimal_ull(struct seq_file m, const char delimiter,
6798a8ca	124	unsigned long long num);
75ba1d07	125	void seq_put_decimal_ll(struct seq_file m, const char delimiter, long long num);
0e3dc019 AV	126	void seq_put_hex_ll(struct seq_file m, const char delimiter,
	127	unsigned long long v, unsigned int width);
	128
6798a8ca	129	void seq_escape(struct seq_file m, const char s, const char *esc);
ea053e16	130	void seq_escape_mem_ascii(struct seq_file m, const char src, size_t isz);
1da177e4	131
37607102 AS	132	void seq_hex_dump(struct seq_file m, const char prefix_str, int prefix_type,
	133	int rowsize, int groupsize, const void *buf, size_t len,
	134	bool ascii);
	135
8c9379e9	136	int seq_path(struct seq_file , const struct path , const char *);
2726d566	137	int seq_file_path(struct seq_file , struct file , const char *);
8c9379e9 AV	138	int seq_dentry(struct seq_file , struct dentry , const char *);
	139	int seq_path_root(struct seq_file m, const struct path path,
	140	const struct path root, const char esc);
3eda2011	141
1da177e4	142	int single_open(struct file , int ()(struct seq_file , void ), void *);
2043f495	143	int single_open_size(struct file , int ()(struct seq_file , void ), void *, size_t);
1da177e4	144	int single_release(struct inode , struct file );
39699037 PE	145	void __seq_open_private(struct file , const struct seq_operations *, int);
39699037 PE	146	int seq_open_private(struct file , const struct seq_operations , int);
1da177e4 LT	147	int seq_release_private(struct inode , struct file );
1da177e4 LT	148
76d6a133 FR	149	#ifdef CONFIG_BINARY_PRINTF
	150	void seq_bprintf(struct seq_file m, const char f, const u32 *binary);
	151	#endif
	152
d2c0e6e9 KW	153	#define DEFINE_SEQ_ATTRIBUTE(__name) \
	154	static int __name ## _open(struct inode inode, struct file file) \
	155	{ \
	156	int ret = seq_open(file, &__name ## _sops); \
	157	if (!ret && inode->i_private) { \
	158	struct seq_file *seq_f = file->private_data; \
	159	seq_f->private = inode->i_private; \
	160	} \
	161	return ret; \
	162	} \
	163	\
	164	static const struct file_operations __name ## _fops = { \
	165	.owner = THIS_MODULE, \
	166	.open = __name ## _open, \
	167	.read = seq_read, \
	168	.llseek = seq_lseek, \
	169	.release = seq_release, \
	170	}
	171
a08f06bb AS	172	#define DEFINE_SHOW_ATTRIBUTE(__name) \
	173	static int __name ## _open(struct inode inode, struct file file) \
	174	{ \
	175	return single_open(file, __name ## _show, inode->i_private); \
	176	} \
	177	\
	178	static const struct file_operations __name ## _fops = { \
	179	.owner = THIS_MODULE, \
	180	.open = __name ## _open, \
	181	.read = seq_read, \
	182	.llseek = seq_lseek, \
	183	.release = single_release, \
	184	}
	185
97a32539 AD	186	#define DEFINE_PROC_SHOW_ATTRIBUTE(__name) \
	187	static int __name ## _open(struct inode inode, struct file file) \
	188	{ \
	189	return single_open(file, __name ## _show, inode->i_private); \
	190	} \
	191	\
	192	static const struct proc_ops __name ## _proc_ops = { \
	193	.proc_open = __name ## _open, \
	194	.proc_read = seq_read, \
	195	.proc_lseek = seq_lseek, \
	196	.proc_release = single_release, \
	197	}
	198
adb37c4c EB	199	static inline struct user_namespace seq_user_ns(struct seq_file seq)
	200	{
	201	#ifdef CONFIG_USER_NS
34dbbcdb	202	return seq->file->f_cred->user_ns;
adb37c4c EB	203	#else
	204	extern struct user_namespace init_user_ns;
	205	return &init_user_ns;
	206	#endif
	207	}
	208
a068acf2 KC	209	/**
	210	* seq_show_options - display mount options with appropriate escapes.
	211	* @m: the seq_file handle
	212	* @name: the mount option name
	213	* @value: the mount option name's value, can be NULL
	214	*/
	215	static inline void seq_show_option(struct seq_file m, const char name,
	216	const char *value)
	217	{
	218	seq_putc(m, ',');
	219	seq_escape(m, name, ",= \t\n\\");
	220	if (value) {
	221	seq_putc(m, '=');
	222	seq_escape(m, value, ", \t\n\\");
	223	}
	224	}
	225
	226	/**
	227	* seq_show_option_n - display mount options with appropriate escapes
	228	* where @value must be a specific length.
	229	* @m: the seq_file handle
	230	* @name: the mount option name
	231	* @value: the mount option name's value, cannot be NULL
	232	* @length: the length of @value to display
	233	*
	234	* This is a macro since this uses "length" to define the size of the
	235	* stack buffer.
	236	*/
	237	#define seq_show_option_n(m, name, value, length) { \
	238	char val_buf[length + 1]; \
	239	strncpy(val_buf, value, length); \
	240	val_buf[length] = '\0'; \
	241	seq_show_option(m, name, val_buf); \
	242	}
	243
1da177e4	244	#define SEQ_START_TOKEN ((void *)1)
bcf67e16 PE	245	/*
	246	* Helpers for iteration over list_head-s in seq_files
	247	*/
	248
	249	extern struct list_head seq_list_start(struct list_head head,
	250	loff_t pos);
	251	extern struct list_head seq_list_start_head(struct list_head head,
	252	loff_t pos);
	253	extern struct list_head seq_list_next(void v, struct list_head *head,
	254	loff_t *ppos);
	255
66655de6 LZ	256	/*
	257	* Helpers for iteration over hlist_head-s in seq_files
	258	*/
	259
	260	extern struct hlist_node seq_hlist_start(struct hlist_head head,
1cc52327	261	loff_t pos);
66655de6	262	extern struct hlist_node seq_hlist_start_head(struct hlist_head head,
1cc52327	263	loff_t pos);
66655de6	264	extern struct hlist_node seq_hlist_next(void v, struct hlist_head *head,
1cc52327	265	loff_t *ppos);
	266
	267	extern struct hlist_node seq_hlist_start_rcu(struct hlist_head head,
	268	loff_t pos);
	269	extern struct hlist_node seq_hlist_start_head_rcu(struct hlist_head head,
	270	loff_t pos);
	271	extern struct hlist_node seq_hlist_next_rcu(void v,
	272	struct hlist_head *head,
	273	loff_t *ppos);
0bc77381 JL	274
	275	/* Helpers for iterating over per-cpu hlist_head-s in seq_files */
	276	extern struct hlist_node seq_hlist_start_percpu(struct hlist_head __percpu head, int *cpu, loff_t pos);
	277
	278	extern struct hlist_node seq_hlist_next_percpu(void v, struct hlist_head __percpu head, int cpu, loff_t *pos);
	279
09652320	280	void seq_file_init(void);
1da177e4	281	#endif