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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/bug.h> | |
8 | #include <linux/mutex.h> | |
9 | #include <linux/cpumask.h> | |
10 | #include <linux/nodemask.h> | |
11 | #include <linux/fs.h> | |
12 | #include <linux/cred.h> | |
13 | ||
14 | struct seq_operations; | |
15 | ||
16 | struct seq_file { | |
17 | char *buf; | |
18 | size_t size; | |
19 | size_t from; | |
20 | size_t count; | |
21 | size_t pad_until; | |
22 | loff_t index; | |
23 | loff_t read_pos; | |
24 | u64 version; | |
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 | static inline size_t seq_get_buf(struct seq_file *m, char **bufp) | |
65 | { | |
66 | BUG_ON(m->count > m->size); | |
67 | if (m->count < m->size) | |
68 | *bufp = m->buf + m->count; | |
69 | else | |
70 | *bufp = NULL; | |
71 | ||
72 | 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 | static inline void seq_commit(struct seq_file *m, int num) | |
85 | { | |
86 | if (num < 0) { | |
87 | m->count = m->size; | |
88 | } else { | |
89 | BUG_ON(m->count + num > m->size); | |
90 | m->count += num; | |
91 | } | |
92 | } | |
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 | 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 | loff_t seq_lseek(struct file *, loff_t, int); | |
112 | int seq_release(struct inode *, struct file *); | |
113 | int seq_write(struct seq_file *seq, const void *data, size_t len); | |
114 | ||
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); | |
121 | void seq_put_decimal_ull_width(struct seq_file *m, const char *delimiter, | |
122 | unsigned long long num, unsigned int width); | |
123 | void seq_put_decimal_ull(struct seq_file *m, const char *delimiter, | |
124 | unsigned long long num); | |
125 | void seq_put_decimal_ll(struct seq_file *m, const char *delimiter, long long num); | |
126 | void seq_put_hex_ll(struct seq_file *m, const char *delimiter, | |
127 | unsigned long long v, unsigned int width); | |
128 | ||
129 | void seq_escape(struct seq_file *m, const char *s, const char *esc); | |
130 | void seq_escape_mem_ascii(struct seq_file *m, const char *src, size_t isz); | |
131 | ||
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 | ||
136 | int seq_path(struct seq_file *, const struct path *, const char *); | |
137 | int seq_file_path(struct seq_file *, struct file *, const char *); | |
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); | |
141 | ||
142 | int single_open(struct file *, int (*)(struct seq_file *, void *), void *); | |
143 | int single_open_size(struct file *, int (*)(struct seq_file *, void *), void *, size_t); | |
144 | int single_release(struct inode *, struct file *); | |
145 | void *__seq_open_private(struct file *, const struct seq_operations *, int); | |
146 | int seq_open_private(struct file *, const struct seq_operations *, int); | |
147 | int seq_release_private(struct inode *, struct file *); | |
148 | ||
149 | #define DEFINE_SHOW_ATTRIBUTE(__name) \ | |
150 | static int __name ## _open(struct inode *inode, struct file *file) \ | |
151 | { \ | |
152 | return single_open(file, __name ## _show, inode->i_private); \ | |
153 | } \ | |
154 | \ | |
155 | static const struct file_operations __name ## _fops = { \ | |
156 | .owner = THIS_MODULE, \ | |
157 | .open = __name ## _open, \ | |
158 | .read = seq_read, \ | |
159 | .llseek = seq_lseek, \ | |
160 | .release = single_release, \ | |
161 | } | |
162 | ||
163 | static inline struct user_namespace *seq_user_ns(struct seq_file *seq) | |
164 | { | |
165 | #ifdef CONFIG_USER_NS | |
166 | return seq->file->f_cred->user_ns; | |
167 | #else | |
168 | extern struct user_namespace init_user_ns; | |
169 | return &init_user_ns; | |
170 | #endif | |
171 | } | |
172 | ||
173 | /** | |
174 | * seq_show_options - display mount options with appropriate escapes. | |
175 | * @m: the seq_file handle | |
176 | * @name: the mount option name | |
177 | * @value: the mount option name's value, can be NULL | |
178 | */ | |
179 | static inline void seq_show_option(struct seq_file *m, const char *name, | |
180 | const char *value) | |
181 | { | |
182 | seq_putc(m, ','); | |
183 | seq_escape(m, name, ",= \t\n\\"); | |
184 | if (value) { | |
185 | seq_putc(m, '='); | |
186 | seq_escape(m, value, ", \t\n\\"); | |
187 | } | |
188 | } | |
189 | ||
190 | /** | |
191 | * seq_show_option_n - display mount options with appropriate escapes | |
192 | * where @value must be a specific length. | |
193 | * @m: the seq_file handle | |
194 | * @name: the mount option name | |
195 | * @value: the mount option name's value, cannot be NULL | |
196 | * @length: the length of @value to display | |
197 | * | |
198 | * This is a macro since this uses "length" to define the size of the | |
199 | * stack buffer. | |
200 | */ | |
201 | #define seq_show_option_n(m, name, value, length) { \ | |
202 | char val_buf[length + 1]; \ | |
203 | strncpy(val_buf, value, length); \ | |
204 | val_buf[length] = '\0'; \ | |
205 | seq_show_option(m, name, val_buf); \ | |
206 | } | |
207 | ||
208 | #define SEQ_START_TOKEN ((void *)1) | |
209 | /* | |
210 | * Helpers for iteration over list_head-s in seq_files | |
211 | */ | |
212 | ||
213 | extern struct list_head *seq_list_start(struct list_head *head, | |
214 | loff_t pos); | |
215 | extern struct list_head *seq_list_start_head(struct list_head *head, | |
216 | loff_t pos); | |
217 | extern struct list_head *seq_list_next(void *v, struct list_head *head, | |
218 | loff_t *ppos); | |
219 | ||
220 | /* | |
221 | * Helpers for iteration over hlist_head-s in seq_files | |
222 | */ | |
223 | ||
224 | extern struct hlist_node *seq_hlist_start(struct hlist_head *head, | |
225 | loff_t pos); | |
226 | extern struct hlist_node *seq_hlist_start_head(struct hlist_head *head, | |
227 | loff_t pos); | |
228 | extern struct hlist_node *seq_hlist_next(void *v, struct hlist_head *head, | |
229 | loff_t *ppos); | |
230 | ||
231 | extern struct hlist_node *seq_hlist_start_rcu(struct hlist_head *head, | |
232 | loff_t pos); | |
233 | extern struct hlist_node *seq_hlist_start_head_rcu(struct hlist_head *head, | |
234 | loff_t pos); | |
235 | extern struct hlist_node *seq_hlist_next_rcu(void *v, | |
236 | struct hlist_head *head, | |
237 | loff_t *ppos); | |
238 | ||
239 | /* Helpers for iterating over per-cpu hlist_head-s in seq_files */ | |
240 | extern struct hlist_node *seq_hlist_start_percpu(struct hlist_head __percpu *head, int *cpu, loff_t pos); | |
241 | ||
242 | extern struct hlist_node *seq_hlist_next_percpu(void *v, struct hlist_head __percpu *head, int *cpu, loff_t *pos); | |
243 | ||
244 | void seq_file_init(void); | |
245 | #endif |