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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * I'm tired of doing "vsnprintf()" etc just to open a
4 * file, so here's a "return static buffer with printf"
5 * interface for paths.
6 *
7 * It's obviously not thread-safe. Sue me. But it's quite
8 * useful for doing things like
9 *
10 * f = open(mkpath("%s/%s.perf", base, name), O_RDONLY);
11 *
12 * which is what it's designed for.
13 */
14#include "path.h"
15#include "cache.h"
16#include <linux/kernel.h>
17#include <limits.h>
18#include <stdio.h>
19#include <string.h>
20#include <sys/types.h>
21#include <sys/stat.h>
22#include <dirent.h>
23#include <unistd.h>
24
25static char bad_path[] = "/bad-path/";
26/*
27 * One hack:
28 */
29static char *get_pathname(void)
30{
31 static char pathname_array[4][PATH_MAX];
32 static int idx;
33
34 return pathname_array[3 & ++idx];
35}
36
37static char *cleanup_path(char *path)
38{
39 /* Clean it up */
40 if (!memcmp(path, "./", 2)) {
41 path += 2;
42 while (*path == '/')
43 path++;
44 }
45 return path;
46}
47
48char *mkpath(const char *fmt, ...)
49{
50 va_list args;
51 unsigned len;
52 char *pathname = get_pathname();
53
54 va_start(args, fmt);
55 len = vsnprintf(pathname, PATH_MAX, fmt, args);
56 va_end(args);
57 if (len >= PATH_MAX)
58 return bad_path;
59 return cleanup_path(pathname);
60}
61
62int path__join(char *bf, size_t size, const char *path1, const char *path2)
63{
64 return scnprintf(bf, size, "%s%s%s", path1, path1[0] ? "/" : "", path2);
65}
66
67int path__join3(char *bf, size_t size, const char *path1, const char *path2, const char *path3)
68{
69 return scnprintf(bf, size, "%s%s%s%s%s", path1, path1[0] ? "/" : "",
70 path2, path2[0] ? "/" : "", path3);
71}
72
73bool is_regular_file(const char *file)
74{
75 struct stat st;
76
77 if (stat(file, &st))
78 return false;
79
80 return S_ISREG(st.st_mode);
81}
82
83/* Helper function for filesystems that return a dent->d_type DT_UNKNOWN */
84bool is_directory(const char *base_path, const struct dirent *dent)
85{
86 char path[PATH_MAX];
87 struct stat st;
88
89 sprintf(path, "%s/%s", base_path, dent->d_name);
90 if (stat(path, &st))
91 return false;
92
93 return S_ISDIR(st.st_mode);
94}
1/*
2 * I'm tired of doing "vsnprintf()" etc just to open a
3 * file, so here's a "return static buffer with printf"
4 * interface for paths.
5 *
6 * It's obviously not thread-safe. Sue me. But it's quite
7 * useful for doing things like
8 *
9 * f = open(mkpath("%s/%s.perf", base, name), O_RDONLY);
10 *
11 * which is what it's designed for.
12 */
13#include "cache.h"
14
15static char bad_path[] = "/bad-path/";
16/*
17 * Two hacks:
18 */
19
20static const char *get_perf_dir(void)
21{
22 return ".";
23}
24
25/*
26 * If libc has strlcpy() then that version will override this
27 * implementation:
28 */
29size_t __weak strlcpy(char *dest, const char *src, size_t size)
30{
31 size_t ret = strlen(src);
32
33 if (size) {
34 size_t len = (ret >= size) ? size - 1 : ret;
35
36 memcpy(dest, src, len);
37 dest[len] = '\0';
38 }
39
40 return ret;
41}
42
43static char *get_pathname(void)
44{
45 static char pathname_array[4][PATH_MAX];
46 static int idx;
47
48 return pathname_array[3 & ++idx];
49}
50
51static char *cleanup_path(char *path)
52{
53 /* Clean it up */
54 if (!memcmp(path, "./", 2)) {
55 path += 2;
56 while (*path == '/')
57 path++;
58 }
59 return path;
60}
61
62static char *perf_vsnpath(char *buf, size_t n, const char *fmt, va_list args)
63{
64 const char *perf_dir = get_perf_dir();
65 size_t len;
66
67 len = strlen(perf_dir);
68 if (n < len + 1)
69 goto bad;
70 memcpy(buf, perf_dir, len);
71 if (len && !is_dir_sep(perf_dir[len-1]))
72 buf[len++] = '/';
73 len += vsnprintf(buf + len, n - len, fmt, args);
74 if (len >= n)
75 goto bad;
76 return cleanup_path(buf);
77bad:
78 strlcpy(buf, bad_path, n);
79 return buf;
80}
81
82char *perf_pathdup(const char *fmt, ...)
83{
84 char path[PATH_MAX];
85 va_list args;
86 va_start(args, fmt);
87 (void)perf_vsnpath(path, sizeof(path), fmt, args);
88 va_end(args);
89 return xstrdup(path);
90}
91
92char *mkpath(const char *fmt, ...)
93{
94 va_list args;
95 unsigned len;
96 char *pathname = get_pathname();
97
98 va_start(args, fmt);
99 len = vsnprintf(pathname, PATH_MAX, fmt, args);
100 va_end(args);
101 if (len >= PATH_MAX)
102 return bad_path;
103 return cleanup_path(pathname);
104}
105
106char *perf_path(const char *fmt, ...)
107{
108 const char *perf_dir = get_perf_dir();
109 char *pathname = get_pathname();
110 va_list args;
111 unsigned len;
112
113 len = strlen(perf_dir);
114 if (len > PATH_MAX-100)
115 return bad_path;
116 memcpy(pathname, perf_dir, len);
117 if (len && perf_dir[len-1] != '/')
118 pathname[len++] = '/';
119 va_start(args, fmt);
120 len += vsnprintf(pathname + len, PATH_MAX - len, fmt, args);
121 va_end(args);
122 if (len >= PATH_MAX)
123 return bad_path;
124 return cleanup_path(pathname);
125}
126
127/* strip arbitrary amount of directory separators at end of path */
128static inline int chomp_trailing_dir_sep(const char *path, int len)
129{
130 while (len && is_dir_sep(path[len - 1]))
131 len--;
132 return len;
133}
134
135/*
136 * If path ends with suffix (complete path components), returns the
137 * part before suffix (sans trailing directory separators).
138 * Otherwise returns NULL.
139 */
140char *strip_path_suffix(const char *path, const char *suffix)
141{
142 int path_len = strlen(path), suffix_len = strlen(suffix);
143
144 while (suffix_len) {
145 if (!path_len)
146 return NULL;
147
148 if (is_dir_sep(path[path_len - 1])) {
149 if (!is_dir_sep(suffix[suffix_len - 1]))
150 return NULL;
151 path_len = chomp_trailing_dir_sep(path, path_len);
152 suffix_len = chomp_trailing_dir_sep(suffix, suffix_len);
153 }
154 else if (path[--path_len] != suffix[--suffix_len])
155 return NULL;
156 }
157
158 if (path_len && !is_dir_sep(path[path_len - 1]))
159 return NULL;
160 return strndup(path, chomp_trailing_dir_sep(path, path_len));
161}