1 /*
2  * Copyright (c) 2018, 2019 Stefan Sperling <stsp@openbsd.org>
3  *
4  * Permission to use, copy, modify, and distribute this software for any
5  * purpose with or without fee is hereby granted, provided that the above
6  * copyright notice and this permission notice appear in all copies.
7  *
8  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
9  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
10  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
11  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
12  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
13  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
14  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
15  */
16 
17 /* Utilities for dealing with filesystem paths. */
18 
19 #define GOT_DEFAULT_FILE_MODE	(S_IFREG | \
20 	S_IRUSR|S_IWUSR | S_IRGRP | S_IROTH)
21 #define GOT_DEFAULT_DIR_MODE	(S_IFDIR | \
22 	S_IRWXU | S_IRGRP|S_IXGRP | S_IROTH|S_IXOTH)
23 
24 struct dirent;
25 
26 /* Determine whether a path is an absolute path. */
27 int got_path_is_absolute(const char *);
28 
29 /*
30  * Canonicalize absolute paths by removing redundant path separators
31  * and resolving references to parent directories ("/../").
32  * Relative paths are copied from input to buf as-is.
33  */
34 const struct got_error *got_canonpath(const char *, char *, size_t);
35 
36 /*
37  * Get child part of two absolute paths. The second path must equal the first
38  * path up to some path component, and must be longer than the first path.
39  * The result is allocated with malloc(3).
40  */
41 const struct got_error *got_path_skip_common_ancestor(char **, const char *,
42     const char *);
43 
44 /* Determine whether a path points to the root directory "/" . */
45 int got_path_is_root_dir(const char *);
46 
47 /* Determine whether a path is a path-wise child of another path. */
48 int got_path_is_child(const char *, const char *, size_t);
49 
50 /*
51  * Like strcmp() but orders children in subdirectories directly after
52  * their parents. String lengths must also be passed in.
53  */
54 int got_path_cmp(const char *, const char *, size_t, size_t);
55 
56 /*
57  * Path lists allow for predictable concurrent iteration over multiple lists
58  * of paths obtained from disparate sources which don't all provide the same
59  * ordering guarantees (e.g. git trees, file index, and on-disk directories).
60  */
61 struct got_pathlist_entry {
62 	TAILQ_ENTRY(got_pathlist_entry) entry;
63 	const char *path;
64 	size_t path_len;
65 	void *data; /* data pointer provided to got_pathlist_insert() */
66 };
67 TAILQ_HEAD(got_pathlist_head, got_pathlist_entry);
68 
69 /*
70  * Insert a path into the list of paths in a predictable order.
71  * The caller should already have initialized the list head. This list stores
72  * the pointer to the path as-is, i.e. the path is not copied internally and
73  * must remain available until the list is freed with got_pathlist_free().
74  * If the first argument is not NULL, set it to a pointer to the newly inserted
75  * element, or to a NULL pointer in case the path was already on the list.
76  */
77 const struct got_error *got_pathlist_insert(struct got_pathlist_entry **,
78     struct got_pathlist_head *, const char *, void *);
79 
80 /*
81  * Append a path to the list of paths.
82  * The caller should already have initialized the list head. This list stores
83  * the pointer to the path as-is, i.e. the path is not copied internally and
84  * must remain available until the list is freed with got_pathlist_free().
85  */
86 const struct got_error *got_pathlist_append(struct got_pathlist_head *,
87     const char *, void *);
88 
89 /* Free resources allocated for a path list. */
90 void got_pathlist_free(struct got_pathlist_head *);
91 
92 /* Attempt to create a directory at a given path. */
93 const struct got_error *got_path_mkdir(const char *);
94 
95 /* Determine whether a directory has no files or directories in it. */
96 int got_path_dir_is_empty(const char *);
97 
98 /*
99  * dirname(3) with error handling, dynamically allocated result, and
100  * unmodified input.
101  */
102 const struct got_error *got_path_dirname(char **, const char *);
103 
104 /*
105  * Obtain the file type of a given directory entry.
106  *
107  * If the entry has some type other than DT_UNKNOWN, resolve to this type.
108  *
109  * Otherwise, attempt to resolve the type of a DT_UNKNOWN directory
110  * entry with lstat(2), though the result may still be DT_UNKNOWN.
111  * This is a fallback to accommodate filesystems which do not provide
112  * directory entry type information.
113  * DT_UNKNOWN directory entries occur on NFS mounts without "readdir plus" RPC.
114  */
115 const struct got_error *got_path_dirent_type(int *, const char *,
116     struct dirent *);
117 
118 /* basename(3) with dynamically allocated result and unmodified input. */
119 const struct got_error *got_path_basename(char **, const char *);
120 
121 /* Strip trailing slashes from a path; path will be modified in-place. */
122 void got_path_strip_trailing_slashes(char *);
123 
124 /* Look up the absolute path of a program in $PATH */
125 const struct got_error *got_path_find_prog(char **, const char *);
126 
127 /* Create a new file at a specified path, with optional content. */
128 const struct got_error *got_path_create_file(const char *, const char *);