1 /*
2 * Copyright (c) 2025-2026 The FreeBSD Foundation
3 * Copyright (c) 2025-2026 Jean-Sébastien Pédron <dumbbell@FreeBSD.org>
4 *
5 * This software was developed by Jean-Sébastien Pédron under sponsorship
6 * from the FreeBSD Foundation.
7 *
8 * SPDX-License-Identifier: BSD-2-Clause
9 */
10
11 #ifndef _LINUXKPI_LINUX_SEQ_BUF_H_
12 #define _LINUXKPI_LINUX_SEQ_BUF_H_
13
14 #include <linux/bug.h>
15 #include <linux/minmax.h>
16 #include <linux/seq_file.h>
17 #include <linux/types.h>
18
19 struct seq_buf {
20 char *buffer;
21 size_t size;
22 size_t len;
23 };
24
25 #define DECLARE_SEQ_BUF(NAME, SIZE) \
26 struct seq_buf NAME = { \
27 .buffer = (char[SIZE]) { 0 }, \
28 .size = SIZE, \
29 }
30
31 static inline void
seq_buf_clear(struct seq_buf * s)32 seq_buf_clear(struct seq_buf *s)
33 {
34 s->len = 0;
35 if (s->size > 0)
36 s->buffer[0] = '\0';
37 }
38
39 static inline void
seq_buf_set_overflow(struct seq_buf * s)40 seq_buf_set_overflow(struct seq_buf *s)
41 {
42 s->len = s->size + 1;
43 }
44
45 static inline bool
seq_buf_has_overflowed(struct seq_buf * s)46 seq_buf_has_overflowed(struct seq_buf *s)
47 {
48 return (s->len > s->size);
49 }
50
51 static inline bool
seq_buf_buffer_left(struct seq_buf * s)52 seq_buf_buffer_left(struct seq_buf *s)
53 {
54 if (seq_buf_has_overflowed(s))
55 return (0);
56
57 return (s->size - s->len);
58 }
59
60 #define seq_buf_init(s, buf, size) linuxkpi_seq_buf_init((s), (buf), (size))
61 void linuxkpi_seq_buf_init(struct seq_buf *s, char *buf, unsigned int size);
62
63 #define seq_buf_printf(s, f, ...) linuxkpi_seq_buf_printf((s), (f), __VA_ARGS__)
64 int linuxkpi_seq_buf_printf(struct seq_buf *s, const char *fmt, ...) \
65 __printflike(2, 3);
66
67 #define seq_buf_vprintf(s, f, a) linuxkpi_seq_buf_vprintf((s), (f), (a))
68 int linuxkpi_seq_buf_vprintf(struct seq_buf *s, const char *fmt, va_list args);
69
70 #define seq_buf_str(s) linuxkpi_seq_buf_str((s))
71 const char * linuxkpi_seq_buf_str(struct seq_buf *s);
72
73 #endif
74