1 #ifndef _LINUX_SEQ_FILE_H
2 #define _LINUX_SEQ_FILE_H
3
4 #include <linux/types.h>
5 #include <linux/string.h>
6 #include <linux/bug.h>
7 #include <linux/mutex.h>
8 #include <linux/cpumask.h>
9 #include <linux/nodemask.h>
10 #include <linux/fs.h>
11 #include <linux/cred.h>
12
13 struct seq_operations;
14
15 struct seq_file {
16 char *buf;
17 size_t size;
18 size_t from;
19 size_t count;
20 size_t pad_until;
21 loff_t index;
22 loff_t read_pos;
23 u64 version;
24 struct mutex lock;
25 const struct seq_operations *op;
26 int poll_event;
27 const struct file *file;
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
38 #define SEQ_SKIP 1
39
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 */
seq_has_overflowed(struct seq_file * m)50 static inline bool seq_has_overflowed(struct seq_file *m)
51 {
52 return m->count == m->size;
53 }
54
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 */
seq_get_buf(struct seq_file * m,char ** bufp)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 */
seq_commit(struct seq_file * m,int num)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
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 */
seq_setwidth(struct seq_file * m,size_t size)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
107 char *mangle_path(char *s, const char *p, const char *esc);
108 int seq_open(struct file *, const struct seq_operations *);
109 ssize_t seq_read(struct file *, char __user *, size_t, loff_t *);
110 loff_t seq_lseek(struct file *, loff_t, int);
111 int seq_release(struct inode *, struct file *);
112 int seq_write(struct seq_file *seq, const void *data, size_t len);
113
114 __printf(2, 0)
115 void seq_vprintf(struct seq_file *m, const char *fmt, va_list args);
116 __printf(2, 3)
117 void seq_printf(struct seq_file *m, const char *fmt, ...);
118 void seq_putc(struct seq_file *m, char c);
119 void seq_puts(struct seq_file *m, const char *s);
120 void seq_put_decimal_ull(struct seq_file *m, const char *delimiter,
121 unsigned long long num);
122 void seq_put_decimal_ll(struct seq_file *m, const char *delimiter, long long num);
123 void seq_escape(struct seq_file *m, const char *s, const char *esc);
124
125 void seq_hex_dump(struct seq_file *m, const char *prefix_str, int prefix_type,
126 int rowsize, int groupsize, const void *buf, size_t len,
127 bool ascii);
128
129 int seq_path(struct seq_file *, const struct path *, const char *);
130 int seq_file_path(struct seq_file *, struct file *, const char *);
131 int seq_dentry(struct seq_file *, struct dentry *, const char *);
132 int seq_path_root(struct seq_file *m, const struct path *path,
133 const struct path *root, const char *esc);
134
135 int single_open(struct file *, int (*)(struct seq_file *, void *), void *);
136 int single_open_size(struct file *, int (*)(struct seq_file *, void *), void *, size_t);
137 int single_release(struct inode *, struct file *);
138 void *__seq_open_private(struct file *, const struct seq_operations *, int);
139 int seq_open_private(struct file *, const struct seq_operations *, int);
140 int seq_release_private(struct inode *, struct file *);
141
seq_user_ns(struct seq_file * seq)142 static inline struct user_namespace *seq_user_ns(struct seq_file *seq)
143 {
144 #ifdef CONFIG_USER_NS
145 return seq->file->f_cred->user_ns;
146 #else
147 extern struct user_namespace init_user_ns;
148 return &init_user_ns;
149 #endif
150 }
151
152 /**
153 * seq_show_options - display mount options with appropriate escapes.
154 * @m: the seq_file handle
155 * @name: the mount option name
156 * @value: the mount option name's value, can be NULL
157 */
seq_show_option(struct seq_file * m,const char * name,const char * value)158 static inline void seq_show_option(struct seq_file *m, const char *name,
159 const char *value)
160 {
161 seq_putc(m, ',');
162 seq_escape(m, name, ",= \t\n\\");
163 if (value) {
164 seq_putc(m, '=');
165 seq_escape(m, value, ", \t\n\\");
166 }
167 }
168
169 /**
170 * seq_show_option_n - display mount options with appropriate escapes
171 * where @value must be a specific length.
172 * @m: the seq_file handle
173 * @name: the mount option name
174 * @value: the mount option name's value, cannot be NULL
175 * @length: the length of @value to display
176 *
177 * This is a macro since this uses "length" to define the size of the
178 * stack buffer.
179 */
180 #define seq_show_option_n(m, name, value, length) { \
181 char val_buf[length + 1]; \
182 strncpy(val_buf, value, length); \
183 val_buf[length] = '\0'; \
184 seq_show_option(m, name, val_buf); \
185 }
186
187 #define SEQ_START_TOKEN ((void *)1)
188 /*
189 * Helpers for iteration over list_head-s in seq_files
190 */
191
192 extern struct list_head *seq_list_start(struct list_head *head,
193 loff_t pos);
194 extern struct list_head *seq_list_start_head(struct list_head *head,
195 loff_t pos);
196 extern struct list_head *seq_list_next(void *v, struct list_head *head,
197 loff_t *ppos);
198
199 /*
200 * Helpers for iteration over hlist_head-s in seq_files
201 */
202
203 extern struct hlist_node *seq_hlist_start(struct hlist_head *head,
204 loff_t pos);
205 extern struct hlist_node *seq_hlist_start_head(struct hlist_head *head,
206 loff_t pos);
207 extern struct hlist_node *seq_hlist_next(void *v, struct hlist_head *head,
208 loff_t *ppos);
209
210 extern struct hlist_node *seq_hlist_start_rcu(struct hlist_head *head,
211 loff_t pos);
212 extern struct hlist_node *seq_hlist_start_head_rcu(struct hlist_head *head,
213 loff_t pos);
214 extern struct hlist_node *seq_hlist_next_rcu(void *v,
215 struct hlist_head *head,
216 loff_t *ppos);
217
218 /* Helpers for iterating over per-cpu hlist_head-s in seq_files */
219 extern struct hlist_node *seq_hlist_start_percpu(struct hlist_head __percpu *head, int *cpu, loff_t pos);
220
221 extern struct hlist_node *seq_hlist_next_percpu(void *v, struct hlist_head __percpu *head, int *cpu, loff_t *pos);
222
223 #endif
224