utils.c revision 54b6cfa9a9e5b861a9930af873580d6dc20f773c 
1/*
2** Copyright 2008, 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#include "installd.h"
18
19int create_pkg_path(char path[PKG_PATH_MAX],
20                    const char *prefix,
21                    const char *pkgname,
22                    const char *postfix)
23{
24    int len;
25    const char *x;
26
27    len = strlen(pkgname);
28    if (len > PKG_NAME_MAX) {
29        return -1;
30    }
31    if ((len + strlen(prefix) + strlen(postfix)) >= PKG_PATH_MAX) {
32        return -1;
33    }
34
35    x = pkgname;
36    while (*x) {
37        if (isalnum(*x) || (*x == '_')) {
38                /* alphanumeric or underscore are fine */
39        } else if (*x == '.') {
40            if ((x == pkgname) || (x[1] == '.') || (x[1] == 0)) {
41                    /* periods must not be first, last, or doubled */
42                LOGE("invalid package name '%s'\n", pkgname);
43                return -1;
44            }
45        } else {
46                /* anything not A-Z, a-z, 0-9, _, or . is invalid */
47            LOGE("invalid package name '%s'\n", pkgname);
48            return -1;
49        }
50        x++;
51    }
52
53    sprintf(path, "%s%s%s", prefix, pkgname, postfix);
54    return 0;
55}
56
57static int _delete_dir_contents(DIR *d, const char *ignore)
58{
59    int result = 0;
60    struct dirent *de;
61    int dfd;
62
63    dfd = dirfd(d);
64
65    if (dfd < 0) return -1;
66
67    while ((de = readdir(d))) {
68        const char *name = de->d_name;
69
70            /* skip the ignore name if provided */
71        if (ignore && !strcmp(name, ignore)) continue;
72
73        if (de->d_type == DT_DIR) {
74            int r, subfd;
75            DIR *subdir;
76
77                /* always skip "." and ".." */
78            if (name[0] == '.') {
79                if (name[1] == 0) continue;
80                if ((name[1] == '.') && (name[2] == 0)) continue;
81            }
82
83            subfd = openat(dfd, name, O_RDONLY | O_DIRECTORY);
84            if (subfd < 0) {
85                result = -1;
86                continue;
87            }
88            subdir = fdopendir(subfd);
89            if (subdir == NULL) {
90                close(subfd);
91                result = -1;
92                continue;
93            }
94            if (_delete_dir_contents(subdir, 0)) {
95                result = -1;
96            }
97            closedir(subdir);
98            if (unlinkat(dfd, name, AT_REMOVEDIR) < 0) {
99                result = -1;
100            }
101        } else {
102            if (unlinkat(dfd, name, 0) < 0) {
103                result = -1;
104            }
105        }
106    }
107
108    return result;
109}
110
111int delete_dir_contents(const char *pathname,
112                        int also_delete_dir,
113                        const char *ignore)
114{
115    int res = 0;
116    DIR *d;
117
118    d = opendir(pathname);
119    if (d == NULL) {
120        return -errno;
121    }
122    res = _delete_dir_contents(d, ignore);
123    closedir(d);
124    if (also_delete_dir) {
125        if (rmdir(pathname)) {
126            res = -1;
127        }
128    }
129    return res;
130}
131
132int delete_dir_contents_fd(int dfd, const char *name)
133{
134    int fd, res;
135    DIR *d;
136
137    fd = openat(dfd, name, O_RDONLY | O_DIRECTORY);
138    if (fd < 0) {
139        return -1;
140    }
141    d = fdopendir(fd);
142    if (d == NULL) {
143        close(fd);
144        return -1;
145    }
146    res = _delete_dir_contents(d, 0);
147    closedir(d);
148    return res;
149}
150