1 // Copyright 2012 Google LLC
2 //
3 // Redistribution and use in source and binary forms, with or without
4 // modification, are permitted provided that the following conditions are
5 // met:
6 //
7 // * Redistributions of source code must retain the above copyright
8 // notice, this list of conditions and the following disclaimer.
9 // * Redistributions in binary form must reproduce the above
10 // copyright notice, this list of conditions and the following disclaimer
11 // in the documentation and/or other materials provided with the
12 // distribution.
13 // * Neither the name of Google LLC nor the names of its
14 // contributors may be used to endorse or promote products derived from
15 // this software without specific prior written permission.
16 //
17 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
18 // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
19 // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
20 // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
21 // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
22 // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
23 // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
24 // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
25 // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
26 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
27 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
28
29 // mkdtemp() wasn't declared in <stdlib.h> until NDK r9b due to a simple
30 // packaging bug (the function has always been implemented in all versions
31 // of the C library). This header is provided to build Breakpad with earlier
32 // NDK revisions (e.g. the one used by Chromium). It may be removed in the
33 // future once all major projects upgrade to use a more recent NDK.
34 //
35 // The reason this is inlined here is to avoid linking a new object file
36 // into each unit test program (i.e. keep build files simple).
37
38 #ifndef GOOGLE_BREAKPAD_COMMON_ANDROID_TESTING_MKDTEMP_H
39 #define GOOGLE_BREAKPAD_COMMON_ANDROID_TESTING_MKDTEMP_H
40
41 #include <assert.h>
42 #include <errno.h>
43 #include <stdlib.h>
44 #include <stdio.h>
45 #include <string.h>
46 #include <sys/stat.h>
47
48 // Using a macro renaming trick here is necessary when building against
49 // NDK r9b. Otherwise the compiler will complain that calls to mkdtemp()
50 // are ambiguous.
51 #define mkdtemp breakpad_mkdtemp
52
53 namespace {
54
breakpad_mkdtemp(char * path)55 char* breakpad_mkdtemp(char* path) {
56 if (path == NULL) {
57 errno = EINVAL;
58 return NULL;
59 }
60
61 // 'path' must be terminated with six 'X'
62 const char kSuffix[] = "XXXXXX";
63 const size_t kSuffixLen = strlen(kSuffix);
64 char* path_end = path + strlen(path);
65
66 if (static_cast<size_t>(path_end - path) < kSuffixLen ||
67 memcmp(path_end - kSuffixLen, kSuffix, kSuffixLen) != 0) {
68 errno = EINVAL;
69 return NULL;
70 }
71
72 // If 'path' contains a directory separator, check that it exists to
73 // avoid looping later.
74 char* sep = strrchr(path, '/');
75 if (sep != NULL) {
76 struct stat st;
77 int ret;
78 *sep = '\0'; // temporarily zero-terminate the dirname.
79 ret = stat(path, &st);
80 *sep = '/'; // restore full path.
81 if (ret < 0)
82 return NULL;
83 if (!S_ISDIR(st.st_mode)) {
84 errno = ENOTDIR;
85 return NULL;
86 }
87 }
88
89 // Loop. On each iteration, replace the XXXXXX suffix with a random
90 // number.
91 int tries;
92 for (tries = 128; tries > 0; tries--) {
93 int random = rand() % 1000000;
94
95 snprintf(path_end - kSuffixLen, kSuffixLen + 1, "%0d", random);
96 if (mkdir(path, 0700) == 0)
97 return path; // Success
98
99 if (errno != EEXIST)
100 return NULL;
101 }
102
103 assert(errno == EEXIST);
104 return NULL;
105 }
106
107 } // namespace
108
109 #endif // GOOGLE_BREAKPAD_COMMON_ANDROID_TESTING_MKDTEMP_H
110