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Commit | Line | Data |
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26c8a533 LT |
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.git", base, name), O_RDONLY); | |
10 | * | |
11 | * which is what it's designed for. | |
12 | */ | |
13 | #include "cache.h" | |
54f4b874 | 14 | #include <pwd.h> |
26c8a533 LT |
15 | |
16 | static char pathname[PATH_MAX]; | |
17 | static char bad_path[] = "/bad-path/"; | |
18 | ||
19 | static char *cleanup_path(char *path) | |
20 | { | |
21 | /* Clean it up */ | |
22 | if (!memcmp(path, "./", 2)) { | |
23 | path += 2; | |
24 | while (*path == '/') | |
25 | path++; | |
26 | } | |
27 | return path; | |
28 | } | |
29 | ||
30 | char *mkpath(const char *fmt, ...) | |
31 | { | |
32 | va_list args; | |
33 | unsigned len; | |
34 | ||
35 | va_start(args, fmt); | |
36 | len = vsnprintf(pathname, PATH_MAX, fmt, args); | |
37 | va_end(args); | |
38 | if (len >= PATH_MAX) | |
39 | return bad_path; | |
40 | return cleanup_path(pathname); | |
41 | } | |
42 | ||
43 | char *git_path(const char *fmt, ...) | |
44 | { | |
5da1606d | 45 | const char *git_dir = get_git_dir(); |
26c8a533 LT |
46 | va_list args; |
47 | unsigned len; | |
48 | ||
49 | len = strlen(git_dir); | |
50 | if (len > PATH_MAX-100) | |
51 | return bad_path; | |
52 | memcpy(pathname, git_dir, len); | |
53 | if (len && git_dir[len-1] != '/') | |
54 | pathname[len++] = '/'; | |
55 | va_start(args, fmt); | |
56 | len += vsnprintf(pathname + len, PATH_MAX - len, fmt, args); | |
57 | va_end(args); | |
58 | if (len >= PATH_MAX) | |
59 | return bad_path; | |
60 | return cleanup_path(pathname); | |
61 | } | |
f2db68ed HE |
62 | |
63 | ||
64 | /* git_mkstemp() - create tmp file honoring TMPDIR variable */ | |
65 | int git_mkstemp(char *path, size_t len, const char *template) | |
66 | { | |
67 | char *env, *pch = path; | |
68 | ||
69 | if ((env = getenv("TMPDIR")) == NULL) { | |
70 | strcpy(pch, "/tmp/"); | |
71 | len -= 5; | |
35c3c629 HE |
72 | pch += 5; |
73 | } else { | |
74 | size_t n = snprintf(pch, len, "%s/", env); | |
75 | ||
76 | len -= n; | |
77 | pch += n; | |
78 | } | |
f2db68ed HE |
79 | |
80 | safe_strncpy(pch, template, len); | |
81 | ||
82 | return mkstemp(path); | |
83 | } | |
84 | ||
85 | ||
86 | char *safe_strncpy(char *dest, const char *src, size_t n) | |
87 | { | |
88 | strncpy(dest, src, n); | |
89 | dest[n - 1] = '\0'; | |
90 | ||
91 | return dest; | |
92 | } | |
54f4b874 | 93 | |
0870ca7f JH |
94 | int validate_symref(const char *path) |
95 | { | |
96 | struct stat st; | |
97 | char *buf, buffer[256]; | |
98 | int len, fd; | |
99 | ||
100 | if (lstat(path, &st) < 0) | |
101 | return -1; | |
102 | ||
103 | /* Make sure it is a "refs/.." symlink */ | |
104 | if (S_ISLNK(st.st_mode)) { | |
105 | len = readlink(path, buffer, sizeof(buffer)-1); | |
106 | if (len >= 5 && !memcmp("refs/", buffer, 5)) | |
107 | return 0; | |
108 | return -1; | |
109 | } | |
110 | ||
111 | /* | |
112 | * Anything else, just open it and try to see if it is a symbolic ref. | |
113 | */ | |
114 | fd = open(path, O_RDONLY); | |
115 | if (fd < 0) | |
116 | return -1; | |
117 | len = read(fd, buffer, sizeof(buffer)-1); | |
118 | close(fd); | |
119 | ||
120 | /* | |
121 | * Is it a symbolic ref? | |
122 | */ | |
123 | if (len < 4 || memcmp("ref:", buffer, 4)) | |
124 | return -1; | |
125 | buf = buffer + 4; | |
126 | len -= 4; | |
127 | while (len && isspace(*buf)) | |
128 | buf++, len--; | |
129 | if (len >= 5 && !memcmp("refs/", buf, 5)) | |
130 | return 0; | |
131 | return -1; | |
132 | } | |
133 | ||
d79374c7 | 134 | static char *user_path(char *buf, char *path, int sz) |
54f4b874 | 135 | { |
d79374c7 JH |
136 | struct passwd *pw; |
137 | char *slash; | |
138 | int len, baselen; | |
54f4b874 | 139 | |
d79374c7 JH |
140 | if (!path || path[0] != '~') |
141 | return NULL; | |
142 | path++; | |
143 | slash = strchr(path, '/'); | |
144 | if (path[0] == '/' || !path[0]) { | |
145 | pw = getpwuid(getuid()); | |
146 | } | |
147 | else { | |
148 | if (slash) { | |
149 | *slash = 0; | |
150 | pw = getpwnam(path); | |
151 | *slash = '/'; | |
54f4b874 | 152 | } |
d79374c7 JH |
153 | else |
154 | pw = getpwnam(path); | |
54f4b874 | 155 | } |
d79374c7 JH |
156 | if (!pw || !pw->pw_dir || sz <= strlen(pw->pw_dir)) |
157 | return NULL; | |
158 | baselen = strlen(pw->pw_dir); | |
159 | memcpy(buf, pw->pw_dir, baselen); | |
160 | while ((1 < baselen) && (buf[baselen-1] == '/')) { | |
161 | buf[baselen-1] = 0; | |
162 | baselen--; | |
163 | } | |
164 | if (slash && slash[1]) { | |
165 | len = strlen(slash); | |
166 | if (sz <= baselen + len) | |
167 | return NULL; | |
168 | memcpy(buf + baselen, slash, len + 1); | |
169 | } | |
170 | return buf; | |
54f4b874 AE |
171 | } |
172 | ||
d79374c7 JH |
173 | /* |
174 | * First, one directory to try is determined by the following algorithm. | |
175 | * | |
176 | * (0) If "strict" is given, the path is used as given and no DWIM is | |
177 | * done. Otherwise: | |
178 | * (1) "~/path" to mean path under the running user's home directory; | |
179 | * (2) "~user/path" to mean path under named user's home directory; | |
180 | * (3) "relative/path" to mean cwd relative directory; or | |
181 | * (4) "/absolute/path" to mean absolute directory. | |
182 | * | |
183 | * Unless "strict" is given, we try access() for existence of "%s.git/.git", | |
184 | * "%s/.git", "%s.git", "%s" in this order. The first one that exists is | |
185 | * what we try. | |
186 | * | |
187 | * Second, we try chdir() to that. Upon failure, we return NULL. | |
188 | * | |
189 | * Then, we try if the current directory is a valid git repository. | |
190 | * Upon failure, we return NULL. | |
191 | * | |
192 | * If all goes well, we return the directory we used to chdir() (but | |
193 | * before ~user is expanded), avoiding getcwd() resolving symbolic | |
194 | * links. User relative paths are also returned as they are given, | |
195 | * except DWIM suffixing. | |
196 | */ | |
54f4b874 AE |
197 | char *enter_repo(char *path, int strict) |
198 | { | |
d79374c7 JH |
199 | static char used_path[PATH_MAX]; |
200 | static char validated_path[PATH_MAX]; | |
201 | ||
202 | if (!path) | |
54f4b874 AE |
203 | return NULL; |
204 | ||
d79374c7 JH |
205 | if (!strict) { |
206 | static const char *suffix[] = { | |
207 | ".git/.git", "/.git", ".git", "", NULL, | |
208 | }; | |
209 | int len = strlen(path); | |
210 | int i; | |
211 | while ((1 < len) && (path[len-1] == '/')) { | |
212 | path[len-1] = 0; | |
213 | len--; | |
214 | } | |
215 | if (PATH_MAX <= len) | |
54f4b874 | 216 | return NULL; |
d79374c7 JH |
217 | if (path[0] == '~') { |
218 | if (!user_path(used_path, path, PATH_MAX)) | |
219 | return NULL; | |
220 | strcpy(validated_path, path); | |
221 | path = used_path; | |
222 | } | |
223 | else if (PATH_MAX - 10 < len) | |
224 | return NULL; | |
225 | else { | |
226 | path = strcpy(used_path, path); | |
227 | strcpy(validated_path, path); | |
228 | } | |
229 | len = strlen(path); | |
230 | for (i = 0; suffix[i]; i++) { | |
231 | strcpy(path + len, suffix[i]); | |
232 | if (!access(path, F_OK)) { | |
233 | strcat(validated_path, suffix[i]); | |
234 | break; | |
235 | } | |
236 | } | |
237 | if (!suffix[i] || chdir(path)) | |
0870ca7f | 238 | return NULL; |
d79374c7 | 239 | path = validated_path; |
0870ca7f | 240 | } |
d79374c7 JH |
241 | else if (chdir(path)) |
242 | return NULL; | |
54f4b874 | 243 | |
d79374c7 JH |
244 | if (access("objects", X_OK) == 0 && access("refs", X_OK) == 0 && |
245 | validate_symref("HEAD") == 0) { | |
54f4b874 | 246 | putenv("GIT_DIR=."); |
1644162a | 247 | check_repository_format(); |
d79374c7 | 248 | return path; |
54f4b874 AE |
249 | } |
250 | ||
251 | return NULL; | |
252 | } |