Line data Source code
1 : /* SPDX-License-Identifier: GPL-2.0 */
2 : #ifndef _LINUX_SEQ_FILE_H
3 : #define _LINUX_SEQ_FILE_H
4 :
5 : #include <linux/types.h>
6 : #include <linux/string.h>
7 : #include <linux/string_helpers.h>
8 : #include <linux/bug.h>
9 : #include <linux/mutex.h>
10 : #include <linux/cpumask.h>
11 : #include <linux/nodemask.h>
12 : #include <linux/fs.h>
13 : #include <linux/cred.h>
14 :
15 : struct seq_operations;
16 :
17 : struct seq_file {
18 : char *buf;
19 : size_t size;
20 : size_t from;
21 : size_t count;
22 : size_t pad_until;
23 : loff_t index;
24 : loff_t read_pos;
25 : struct mutex lock;
26 : const struct seq_operations *op;
27 : int poll_event;
28 : const struct file *file;
29 : void *private;
30 : };
31 :
32 : struct seq_operations {
33 : void * (*start) (struct seq_file *m, loff_t *pos);
34 : void (*stop) (struct seq_file *m, void *v);
35 : void * (*next) (struct seq_file *m, void *v, loff_t *pos);
36 : int (*show) (struct seq_file *m, void *v);
37 : };
38 :
39 : #define SEQ_SKIP 1
40 :
41 : /**
42 : * seq_has_overflowed - check if the buffer has overflowed
43 : * @m: the seq_file handle
44 : *
45 : * seq_files have a buffer which may overflow. When this happens a larger
46 : * buffer is reallocated and all the data will be printed again.
47 : * The overflow state is true when m->count == m->size.
48 : *
49 : * Returns true if the buffer received more than it can hold.
50 : */
51 : static inline bool seq_has_overflowed(struct seq_file *m)
52 : {
53 : return m->count == m->size;
54 : }
55 :
56 : /**
57 : * seq_get_buf - get buffer to write arbitrary data to
58 : * @m: the seq_file handle
59 : * @bufp: the beginning of the buffer is stored here
60 : *
61 : * Return the number of bytes available in the buffer, or zero if
62 : * there's no space.
63 : */
64 0 : static inline size_t seq_get_buf(struct seq_file *m, char **bufp)
65 : {
66 0 : BUG_ON(m->count > m->size);
67 0 : if (m->count < m->size)
68 0 : *bufp = m->buf + m->count;
69 : else
70 0 : *bufp = NULL;
71 :
72 0 : return m->size - m->count;
73 : }
74 :
75 : /**
76 : * seq_commit - commit data to the buffer
77 : * @m: the seq_file handle
78 : * @num: the number of bytes to commit
79 : *
80 : * Commit @num bytes of data written to a buffer previously acquired
81 : * by seq_buf_get. To signal an error condition, or that the data
82 : * didn't fit in the available space, pass a negative @num value.
83 : */
84 0 : static inline void seq_commit(struct seq_file *m, int num)
85 : {
86 0 : if (num < 0) {
87 0 : m->count = m->size;
88 : } else {
89 0 : BUG_ON(m->count + num > m->size);
90 0 : m->count += num;
91 : }
92 0 : }
93 :
94 : /**
95 : * seq_setwidth - set padding width
96 : * @m: the seq_file handle
97 : * @size: the max number of bytes to pad.
98 : *
99 : * Call seq_setwidth() for setting max width, then call seq_printf() etc. and
100 : * finally call seq_pad() to pad the remaining bytes.
101 : */
102 : static inline void seq_setwidth(struct seq_file *m, size_t size)
103 : {
104 0 : m->pad_until = m->count + size;
105 : }
106 : void seq_pad(struct seq_file *m, char c);
107 :
108 : char *mangle_path(char *s, const char *p, const char *esc);
109 : int seq_open(struct file *, const struct seq_operations *);
110 : ssize_t seq_read(struct file *, char __user *, size_t, loff_t *);
111 : ssize_t seq_read_iter(struct kiocb *iocb, struct iov_iter *iter);
112 : loff_t seq_lseek(struct file *, loff_t, int);
113 : int seq_release(struct inode *, struct file *);
114 : int seq_write(struct seq_file *seq, const void *data, size_t len);
115 :
116 : __printf(2, 0)
117 : void seq_vprintf(struct seq_file *m, const char *fmt, va_list args);
118 : __printf(2, 3)
119 : void seq_printf(struct seq_file *m, const char *fmt, ...);
120 : void seq_putc(struct seq_file *m, char c);
121 : void seq_puts(struct seq_file *m, const char *s);
122 : void seq_put_decimal_ull_width(struct seq_file *m, const char *delimiter,
123 : unsigned long long num, unsigned int width);
124 : void seq_put_decimal_ull(struct seq_file *m, const char *delimiter,
125 : unsigned long long num);
126 : void seq_put_decimal_ll(struct seq_file *m, const char *delimiter, long long num);
127 : void seq_put_hex_ll(struct seq_file *m, const char *delimiter,
128 : unsigned long long v, unsigned int width);
129 :
130 : void seq_escape_mem(struct seq_file *m, const char *src, size_t len,
131 : unsigned int flags, const char *esc);
132 :
133 : static inline void seq_escape_str(struct seq_file *m, const char *src,
134 : unsigned int flags, const char *esc)
135 : {
136 0 : seq_escape_mem(m, src, strlen(src), flags, esc);
137 : }
138 :
139 : /**
140 : * seq_escape - print string into buffer, escaping some characters
141 : * @m: target buffer
142 : * @s: NULL-terminated string
143 : * @esc: set of characters that need escaping
144 : *
145 : * Puts string into buffer, replacing each occurrence of character from
146 : * @esc with usual octal escape.
147 : *
148 : * Use seq_has_overflowed() to check for errors.
149 : */
150 0 : static inline void seq_escape(struct seq_file *m, const char *s, const char *esc)
151 : {
152 0 : seq_escape_str(m, s, ESCAPE_OCTAL, esc);
153 0 : }
154 :
155 : void seq_hex_dump(struct seq_file *m, const char *prefix_str, int prefix_type,
156 : int rowsize, int groupsize, const void *buf, size_t len,
157 : bool ascii);
158 :
159 : int seq_path(struct seq_file *, const struct path *, const char *);
160 : int seq_file_path(struct seq_file *, struct file *, const char *);
161 : int seq_dentry(struct seq_file *, struct dentry *, const char *);
162 : int seq_path_root(struct seq_file *m, const struct path *path,
163 : const struct path *root, const char *esc);
164 :
165 : void *single_start(struct seq_file *, loff_t *);
166 : int single_open(struct file *, int (*)(struct seq_file *, void *), void *);
167 : int single_open_size(struct file *, int (*)(struct seq_file *, void *), void *, size_t);
168 : int single_release(struct inode *, struct file *);
169 : void *__seq_open_private(struct file *, const struct seq_operations *, int);
170 : int seq_open_private(struct file *, const struct seq_operations *, int);
171 : int seq_release_private(struct inode *, struct file *);
172 :
173 : #ifdef CONFIG_BINARY_PRINTF
174 : void seq_bprintf(struct seq_file *m, const char *f, const u32 *binary);
175 : #endif
176 :
177 : #define DEFINE_SEQ_ATTRIBUTE(__name) \
178 : static int __name ## _open(struct inode *inode, struct file *file) \
179 : { \
180 : int ret = seq_open(file, &__name ## _sops); \
181 : if (!ret && inode->i_private) { \
182 : struct seq_file *seq_f = file->private_data; \
183 : seq_f->private = inode->i_private; \
184 : } \
185 : return ret; \
186 : } \
187 : \
188 : static const struct file_operations __name ## _fops = { \
189 : .owner = THIS_MODULE, \
190 : .open = __name ## _open, \
191 : .read = seq_read, \
192 : .llseek = seq_lseek, \
193 : .release = seq_release, \
194 : }
195 :
196 : #define DEFINE_SHOW_ATTRIBUTE(__name) \
197 : static int __name ## _open(struct inode *inode, struct file *file) \
198 : { \
199 : return single_open(file, __name ## _show, inode->i_private); \
200 : } \
201 : \
202 : static const struct file_operations __name ## _fops = { \
203 : .owner = THIS_MODULE, \
204 : .open = __name ## _open, \
205 : .read = seq_read, \
206 : .llseek = seq_lseek, \
207 : .release = single_release, \
208 : }
209 :
210 : #define DEFINE_PROC_SHOW_ATTRIBUTE(__name) \
211 : static int __name ## _open(struct inode *inode, struct file *file) \
212 : { \
213 : return single_open(file, __name ## _show, pde_data(inode)); \
214 : } \
215 : \
216 : static const struct proc_ops __name ## _proc_ops = { \
217 : .proc_open = __name ## _open, \
218 : .proc_read = seq_read, \
219 : .proc_lseek = seq_lseek, \
220 : .proc_release = single_release, \
221 : }
222 :
223 : static inline struct user_namespace *seq_user_ns(struct seq_file *seq)
224 : {
225 : #ifdef CONFIG_USER_NS
226 : return seq->file->f_cred->user_ns;
227 : #else
228 : extern struct user_namespace init_user_ns;
229 : return &init_user_ns;
230 : #endif
231 : }
232 :
233 : /**
234 : * seq_show_options - display mount options with appropriate escapes.
235 : * @m: the seq_file handle
236 : * @name: the mount option name
237 : * @value: the mount option name's value, can be NULL
238 : */
239 : static inline void seq_show_option(struct seq_file *m, const char *name,
240 : const char *value)
241 : {
242 : seq_putc(m, ',');
243 : seq_escape(m, name, ",= \t\n\\");
244 : if (value) {
245 : seq_putc(m, '=');
246 : seq_escape(m, value, ", \t\n\\");
247 : }
248 : }
249 :
250 : /**
251 : * seq_show_option_n - display mount options with appropriate escapes
252 : * where @value must be a specific length.
253 : * @m: the seq_file handle
254 : * @name: the mount option name
255 : * @value: the mount option name's value, cannot be NULL
256 : * @length: the length of @value to display
257 : *
258 : * This is a macro since this uses "length" to define the size of the
259 : * stack buffer.
260 : */
261 : #define seq_show_option_n(m, name, value, length) { \
262 : char val_buf[length + 1]; \
263 : strncpy(val_buf, value, length); \
264 : val_buf[length] = '\0'; \
265 : seq_show_option(m, name, val_buf); \
266 : }
267 :
268 : #define SEQ_START_TOKEN ((void *)1)
269 : /*
270 : * Helpers for iteration over list_head-s in seq_files
271 : */
272 :
273 : extern struct list_head *seq_list_start(struct list_head *head,
274 : loff_t pos);
275 : extern struct list_head *seq_list_start_head(struct list_head *head,
276 : loff_t pos);
277 : extern struct list_head *seq_list_next(void *v, struct list_head *head,
278 : loff_t *ppos);
279 :
280 : extern struct list_head *seq_list_start_rcu(struct list_head *head, loff_t pos);
281 : extern struct list_head *seq_list_start_head_rcu(struct list_head *head, loff_t pos);
282 : extern struct list_head *seq_list_next_rcu(void *v, struct list_head *head, loff_t *ppos);
283 :
284 : /*
285 : * Helpers for iteration over hlist_head-s in seq_files
286 : */
287 :
288 : extern struct hlist_node *seq_hlist_start(struct hlist_head *head,
289 : loff_t pos);
290 : extern struct hlist_node *seq_hlist_start_head(struct hlist_head *head,
291 : loff_t pos);
292 : extern struct hlist_node *seq_hlist_next(void *v, struct hlist_head *head,
293 : loff_t *ppos);
294 :
295 : extern struct hlist_node *seq_hlist_start_rcu(struct hlist_head *head,
296 : loff_t pos);
297 : extern struct hlist_node *seq_hlist_start_head_rcu(struct hlist_head *head,
298 : loff_t pos);
299 : extern struct hlist_node *seq_hlist_next_rcu(void *v,
300 : struct hlist_head *head,
301 : loff_t *ppos);
302 :
303 : /* Helpers for iterating over per-cpu hlist_head-s in seq_files */
304 : extern struct hlist_node *seq_hlist_start_percpu(struct hlist_head __percpu *head, int *cpu, loff_t pos);
305 :
306 : extern struct hlist_node *seq_hlist_next_percpu(void *v, struct hlist_head __percpu *head, int *cpu, loff_t *pos);
307 :
308 : void seq_file_init(void);
309 : #endif
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