1 /*
2 * Copyright (C) 2016 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17 #define LOG_TAG "incidentd"
18
19 #include "report_directory.h"
20
21 #include <cutils/log.h>
22 #include <private/android_filesystem_config.h>
23 #include <utils/String8.h>
24
25 #include <sys/types.h>
26 #include <sys/stat.h>
27 #include <dirent.h>
28 #include <libgen.h>
29 #include <unistd.h>
30
31 #include <vector>
32
33 using namespace android;
34 using namespace std;
35
36 status_t
create_directory(const char * directory)37 create_directory(const char* directory)
38 {
39 struct stat st;
40 status_t err = NO_ERROR;
41 char* dir = strdup(directory);
42
43 // Skip first slash
44 char* d = dir + 1;
45
46 // Create directories, assigning them to the system user
47 bool last = false;
48 while (!last) {
49 d = strchr(d, '/');
50 if (d != NULL) {
51 *d = '\0';
52 } else {
53 last = true;
54 }
55 if (stat(dir, &st) == 0) {
56 if (!S_ISDIR(st.st_mode)) {
57 err = ALREADY_EXISTS;
58 goto done;
59 }
60 } else {
61 if (mkdir(dir, 0770)) {
62 ALOGE("No incident reports today. "
63 "Unable to create incident report dir %s: %s", dir,
64 strerror(errno));
65 err = -errno;
66 goto done;
67 }
68 if (chmod(dir, 0770)) {
69 ALOGE("No incident reports today. "
70 "Unable to set permissions for incident report dir %s: %s", dir,
71 strerror(errno));
72 err = -errno;
73 goto done;
74 }
75 if (chown(dir, AID_SYSTEM, AID_SYSTEM)) {
76 ALOGE("No incident reports today. Unable to change ownership of dir %s: %s\n",
77 dir, strerror(errno));
78 err = -errno;
79 goto done;
80 }
81 }
82 if (!last) {
83 *d++ = '/';
84 }
85 }
86
87 // Ensure that the final directory is owned by the system with 0770. If it isn't
88 // we won't write into it.
89 if (stat(directory, &st) != 0) {
90 ALOGE("No incident reports today. Can't stat: %s", directory);
91 err = -errno;
92 goto done;
93 }
94 if ((st.st_mode & 0777) != 0770) {
95 ALOGE("No incident reports today. Mode is %0o on report directory %s",
96 st.st_mode, directory);
97 err = BAD_VALUE;
98 goto done;
99 }
100 if (st.st_uid != AID_SYSTEM || st.st_gid != AID_SYSTEM) {
101 ALOGE("No incident reports today. Owner is %d and group is %d on report directory %s",
102 st.st_uid, st.st_gid, directory);
103 err = BAD_VALUE;
104 goto done;
105 }
106
107 done:
108 free(dir);
109 return err;
110 }
111
112 static bool
stat_mtime_cmp(const pair<String8,struct stat> & a,const pair<String8,struct stat> & b)113 stat_mtime_cmp(const pair<String8,struct stat>& a, const pair<String8,struct stat>& b)
114 {
115 return a.second.st_mtime < b.second.st_mtime;
116 }
117
118 void
clean_directory(const char * directory,off_t maxSize,size_t maxCount)119 clean_directory(const char* directory, off_t maxSize, size_t maxCount)
120 {
121 DIR* dir;
122 struct dirent* entry;
123 struct stat st;
124
125 vector<pair<String8,struct stat>> files;
126
127 if ((dir = opendir(directory)) == NULL) {
128 ALOGE("Couldn't open incident directory: %s", directory);
129 return;
130 }
131
132 String8 dirbase(String8(directory) + "/");
133
134 off_t totalSize = 0;
135 size_t totalCount = 0;
136
137 // Enumerate, count and add up size
138 while ((entry = readdir(dir)) != NULL) {
139 if (entry->d_name[0] == '.') {
140 continue;
141 }
142 String8 filename = dirbase + entry->d_name;
143 if (stat(filename.string(), &st) != 0) {
144 ALOGE("Unable to stat file %s", filename.string());
145 continue;
146 }
147 if (!S_ISREG(st.st_mode)) {
148 continue;
149 }
150 files.push_back(pair<String8,struct stat>(filename, st));
151
152 totalSize += st.st_size;
153 totalCount++;
154 }
155
156 closedir(dir);
157
158 // Count or size is less than max, then we're done.
159 if (totalSize < maxSize && totalCount < maxCount) {
160 return;
161 }
162
163 // Oldest files first.
164 sort(files.begin(), files.end(), stat_mtime_cmp);
165
166 // Remove files until we're under our limits.
167 for (vector<pair<String8,struct stat>>::iterator it = files.begin();
168 it != files.end() && totalSize >= maxSize && totalCount >= maxCount; it++) {
169 remove(it->first.string());
170 totalSize -= it->second.st_size;
171 totalCount--;
172 }
173 }
174