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 11 struct seq_operations; 12 struct file; 13 struct path; 14 struct inode; 15 struct dentry; 16 struct user_namespace; 17 18 struct seq_file { 19 char *buf; 20 size_t size; 21 size_t from; 22 size_t count; 23 size_t pad_until; 24 loff_t index; 25 loff_t read_pos; 26 u64 version; 27 struct mutex lock; 28 const struct seq_operations *op; 29 int poll_event; 30 #ifdef CONFIG_USER_NS 31 struct user_namespace *user_ns; 32 #endif 33 void *private; 34 }; 35 36 struct seq_operations { 37 void * (*start) (struct seq_file *m, loff_t *pos); 38 void (*stop) (struct seq_file *m, void *v); 39 void * (*next) (struct seq_file *m, void *v, loff_t *pos); 40 int (*show) (struct seq_file *m, void *v); 41 }; 42 43 #define SEQ_SKIP 1 44 45 /** 46 * seq_has_overflowed - check if the buffer has overflowed 47 * @m: the seq_file handle 48 * 49 * seq_files have a buffer which may overflow. When this happens a larger 50 * buffer is reallocated and all the data will be printed again. 51 * The overflow state is true when m->count == m->size. 52 * 53 * Returns true if the buffer received more than it can hold. 54 */ 55 static inline bool seq_has_overflowed(struct seq_file *m) 56 { 57 return m->count == m->size; 58 } 59 60 /** 61 * seq_get_buf - get buffer to write arbitrary data to 62 * @m: the seq_file handle 63 * @bufp: the beginning of the buffer is stored here 64 * 65 * Return the number of bytes available in the buffer, or zero if 66 * there's no space. 67 */ 68 static inline size_t seq_get_buf(struct seq_file *m, char **bufp) 69 { 70 BUG_ON(m->count > m->size); 71 if (m->count < m->size) 72 *bufp = m->buf + m->count; 73 else 74 *bufp = NULL; 75 76 return m->size - m->count; 77 } 78 79 /** 80 * seq_commit - commit data to the buffer 81 * @m: the seq_file handle 82 * @num: the number of bytes to commit 83 * 84 * Commit @num bytes of data written to a buffer previously acquired 85 * by seq_buf_get. To signal an error condition, or that the data 86 * didn't fit in the available space, pass a negative @num value. 87 */ 88 static inline void seq_commit(struct seq_file *m, int num) 89 { 90 if (num < 0) { 91 m->count = m->size; 92 } else { 93 BUG_ON(m->count + num > m->size); 94 m->count += num; 95 } 96 } 97 98 /** 99 * seq_setwidth - set padding width 100 * @m: the seq_file handle 101 * @size: the max number of bytes to pad. 102 * 103 * Call seq_setwidth() for setting max width, then call seq_printf() etc. and 104 * finally call seq_pad() to pad the remaining bytes. 105 */ 106 static inline void seq_setwidth(struct seq_file *m, size_t size) 107 { 108 m->pad_until = m->count + size; 109 } 110 void seq_pad(struct seq_file *m, char c); 111 112 char *mangle_path(char *s, const char *p, const char *esc); 113 int seq_open(struct file *, const struct seq_operations *); 114 ssize_t seq_read(struct file *, char __user *, size_t, loff_t *); 115 loff_t seq_lseek(struct file *, loff_t, int); 116 int seq_release(struct inode *, struct file *); 117 int seq_escape(struct seq_file *, const char *, const char *); 118 int seq_putc(struct seq_file *m, char c); 119 int seq_puts(struct seq_file *m, const char *s); 120 int seq_write(struct seq_file *seq, const void *data, size_t len); 121 122 __printf(2, 3) int seq_printf(struct seq_file *, const char *, ...); 123 __printf(2, 0) int seq_vprintf(struct seq_file *, const char *, va_list args); 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 int seq_put_decimal_ull(struct seq_file *m, char delimiter, 142 unsigned long long num); 143 int seq_put_decimal_ll(struct seq_file *m, char delimiter, 144 long long num); 145 146 static inline struct user_namespace *seq_user_ns(struct seq_file *seq) 147 { 148 #ifdef CONFIG_USER_NS 149 return seq->user_ns; 150 #else 151 extern struct user_namespace init_user_ns; 152 return &init_user_ns; 153 #endif 154 } 155 156 /** 157 * seq_show_options - display mount options with appropriate escapes. 158 * @m: the seq_file handle 159 * @name: the mount option name 160 * @value: the mount option name's value, can be NULL 161 */ 162 static inline void seq_show_option(struct seq_file *m, const char *name, 163 const char *value) 164 { 165 seq_putc(m, ','); 166 seq_escape(m, name, ",= \t\n\\"); 167 if (value) { 168 seq_putc(m, '='); 169 seq_escape(m, value, ", \t\n\\"); 170 } 171 } 172 173 /** 174 * seq_show_option_n - display mount options with appropriate escapes 175 * where @value must be a specific length. 176 * @m: the seq_file handle 177 * @name: the mount option name 178 * @value: the mount option name's value, cannot be NULL 179 * @length: the length of @value to display 180 * 181 * This is a macro since this uses "length" to define the size of the 182 * stack buffer. 183 */ 184 #define seq_show_option_n(m, name, value, length) { \ 185 char val_buf[length + 1]; \ 186 strncpy(val_buf, value, length); \ 187 val_buf[length] = '\0'; \ 188 seq_show_option(m, name, val_buf); \ 189 } 190 191 #define SEQ_START_TOKEN ((void *)1) 192 /* 193 * Helpers for iteration over list_head-s in seq_files 194 */ 195 196 extern struct list_head *seq_list_start(struct list_head *head, 197 loff_t pos); 198 extern struct list_head *seq_list_start_head(struct list_head *head, 199 loff_t pos); 200 extern struct list_head *seq_list_next(void *v, struct list_head *head, 201 loff_t *ppos); 202 203 /* 204 * Helpers for iteration over hlist_head-s in seq_files 205 */ 206 207 extern struct hlist_node *seq_hlist_start(struct hlist_head *head, 208 loff_t pos); 209 extern struct hlist_node *seq_hlist_start_head(struct hlist_head *head, 210 loff_t pos); 211 extern struct hlist_node *seq_hlist_next(void *v, struct hlist_head *head, 212 loff_t *ppos); 213 214 extern struct hlist_node *seq_hlist_start_rcu(struct hlist_head *head, 215 loff_t pos); 216 extern struct hlist_node *seq_hlist_start_head_rcu(struct hlist_head *head, 217 loff_t pos); 218 extern struct hlist_node *seq_hlist_next_rcu(void *v, 219 struct hlist_head *head, 220 loff_t *ppos); 221 222 /* Helpers for iterating over per-cpu hlist_head-s in seq_files */ 223 extern struct hlist_node *seq_hlist_start_percpu(struct hlist_head __percpu *head, int *cpu, loff_t pos); 224 225 extern struct hlist_node *seq_hlist_next_percpu(void *v, struct hlist_head __percpu *head, int *cpu, loff_t *pos); 226 227 #endif 228