utils.c revision c028be4f3b8c7476b46859f66c3f33d528adf181 
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    int alpha = -1;
37    while (*x) {
38        if (isalnum(*x) || (*x == '_')) {
39                /* alphanumeric or underscore are fine */
40        } else if (*x == '.') {
41            if ((x == pkgname) || (x[1] == '.') || (x[1] == 0)) {
42                    /* periods must not be first, last, or doubled */
43                LOGE("invalid package name '%s'\n", pkgname);
44                return -1;
45            }
46        } else if (*x == '-') {
47            /* Suffix -X is fine to let versioning of packages.
48               But whatever follows should be alphanumeric.*/
49            alpha = 1;
50        }else {
51                /* anything not A-Z, a-z, 0-9, _, or . is invalid */
52            LOGE("invalid package name '%s'\n", pkgname);
53            return -1;
54        }
55        x++;
56    }
57    if (alpha == 1) {
58        // Skip current character
59        x++;
60        while (*x) {
61            if (!isalnum(*x)) {
62                LOGE("invalid package name '%s' should include only numbers after -\n", pkgname);
63                return -1;
64            }
65            x++;
66        }
67    }
68
69    sprintf(path, "%s%s%s", prefix, pkgname, postfix);
70    return 0;
71}
72
73static int _delete_dir_contents(DIR *d, const char *ignore)
74{
75    int result = 0;
76    struct dirent *de;
77    int dfd;
78
79    dfd = dirfd(d);
80
81    if (dfd < 0) return -1;
82
83    while ((de = readdir(d))) {
84        const char *name = de->d_name;
85
86            /* skip the ignore name if provided */
87        if (ignore && !strcmp(name, ignore)) continue;
88
89        if (de->d_type == DT_DIR) {
90            int r, subfd;
91            DIR *subdir;
92
93                /* always skip "." and ".." */
94            if (name[0] == '.') {
95                if (name[1] == 0) continue;
96                if ((name[1] == '.') && (name[2] == 0)) continue;
97            }
98
99            subfd = openat(dfd, name, O_RDONLY | O_DIRECTORY);
100            if (subfd < 0) {
101                result = -1;
102                continue;
103            }
104            subdir = fdopendir(subfd);
105            if (subdir == NULL) {
106                close(subfd);
107                result = -1;
108                continue;
109            }
110            if (_delete_dir_contents(subdir, 0)) {
111                result = -1;
112            }
113            closedir(subdir);
114            if (unlinkat(dfd, name, AT_REMOVEDIR) < 0) {
115                result = -1;
116            }
117        } else {
118            if (unlinkat(dfd, name, 0) < 0) {
119                result = -1;
120            }
121        }
122    }
123
124    return result;
125}
126
127int delete_dir_contents(const char *pathname,
128                        int also_delete_dir,
129                        const char *ignore)
130{
131    int res = 0;
132    DIR *d;
133
134    d = opendir(pathname);
135    if (d == NULL) {
136        return -errno;
137    }
138    res = _delete_dir_contents(d, ignore);
139    closedir(d);
140    if (also_delete_dir) {
141        if (rmdir(pathname)) {
142            res = -1;
143        }
144    }
145    return res;
146}
147
148int delete_dir_contents_fd(int dfd, const char *name)
149{
150    int fd, res;
151    DIR *d;
152
153    fd = openat(dfd, name, O_RDONLY | O_DIRECTORY);
154    if (fd < 0) {
155        return -1;
156    }
157    d = fdopendir(fd);
158    if (d == NULL) {
159        close(fd);
160        return -1;
161    }
162    res = _delete_dir_contents(d, 0);
163    closedir(d);
164    return res;
165}
166