1 /*
2 * Copyright (C) 2019 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 "packagelistparser"
18
19 #include <packagelistparser/packagelistparser.h>
20
21 #include <errno.h>
22 #include <inttypes.h>
23 #include <stdio.h>
24 #include <string.h>
25 #include <sys/limits.h>
26
27 #include <memory>
28
29 #include <log/log.h>
30
parse_gids(const char * path,size_t line_number,const char * gids,pkg_info * info)31 static bool parse_gids(const char* path, size_t line_number, const char* gids, pkg_info* info) {
32 // Nothing to do?
33 if (!gids || !strcmp(gids, "none")) return true;
34
35 // How much space do we need?
36 info->gids.cnt = 1;
37 for (const char* p = gids; *p; ++p) {
38 if (*p == ',') ++info->gids.cnt;
39 }
40
41 // Allocate the space.
42 info->gids.gids = new gid_t[info->gids.cnt];
43 if (!info->gids.gids) return false;
44
45 // And parse the individual gids.
46 size_t i = 0;
47 while (true) {
48 char* end;
49 unsigned long gid = strtoul(gids, &end, 10);
50 if (gid > GID_MAX) {
51 ALOGE("%s:%zu: gid %lu > GID_MAX", path, line_number, gid);
52 return false;
53 }
54
55 if (i >= info->gids.cnt) return false;
56 info->gids.gids[i++] = gid;
57
58 if (*end == '\0') return true;
59 if (*end != ',') return false;
60 gids = end + 1;
61 }
62 return true;
63 }
64
parse_line(const char * path,size_t line_number,const char * line,pkg_info * info)65 static bool parse_line(const char* path, size_t line_number, const char* line, pkg_info* info) {
66 unsigned long uid;
67 int debuggable;
68 char* gid_list;
69 int profileable_from_shell = 0;
70
71 int fields =
72 sscanf(line, "%ms %lu %d %ms %ms %ms %d %ld", &info->name, &uid, &debuggable, &info->data_dir,
73 &info->seinfo, &gid_list, &profileable_from_shell, &info->version_code);
74
75 // Handle the more complicated gids field and free the temporary string.
76 bool gids_okay = parse_gids(path, line_number, gid_list, info);
77 free(gid_list);
78 if (!gids_okay) return false;
79
80 // Did we see enough fields to be getting on with?
81 // The final fields are optional (and not usually present).
82 if (fields < 6) {
83 ALOGE("%s:%zu: too few fields in line", path, line_number);
84 return false;
85 }
86
87 // Extra validation.
88 if (uid > UID_MAX) {
89 ALOGE("%s:%zu: uid %lu > UID_MAX", path, line_number, uid);
90 return false;
91 }
92 info->uid = uid;
93
94 // Integer to bool conversions.
95 info->debuggable = debuggable;
96 info->profileable_from_shell = profileable_from_shell;
97
98 return true;
99 }
100
packagelist_parse_file(const char * path,bool (* callback)(pkg_info *,void *),void * user_data)101 bool packagelist_parse_file(const char* path, bool (*callback)(pkg_info*, void*), void* user_data) {
102 std::unique_ptr<FILE, decltype(&fclose)> fp(fopen(path, "re"), &fclose);
103 if (!fp) {
104 ALOGE("couldn't open '%s': %s", path, strerror(errno));
105 return false;
106 }
107
108 size_t line_number = 0;
109 char* line = nullptr;
110 size_t allocated_length = 0;
111 while (getline(&line, &allocated_length, fp.get()) > 0) {
112 ++line_number;
113 std::unique_ptr<pkg_info, decltype(&packagelist_free)> info(
114 static_cast<pkg_info*>(calloc(1, sizeof(pkg_info))), &packagelist_free);
115 if (!info) {
116 ALOGE("%s:%zu: couldn't allocate pkg_info", path, line_number);
117 return false;
118 }
119
120 if (!parse_line(path, line_number, line, info.get())) return false;
121
122 if (!callback(info.release(), user_data)) break;
123 }
124 free(line);
125 return true;
126 }
127
packagelist_parse(bool (* callback)(pkg_info *,void *),void * user_data)128 bool packagelist_parse(bool (*callback)(pkg_info*, void*), void* user_data) {
129 return packagelist_parse_file("/data/system/packages.list", callback, user_data);
130 }
131
packagelist_free(pkg_info * info)132 void packagelist_free(pkg_info* info) {
133 if (!info) return;
134
135 free(info->name);
136 free(info->data_dir);
137 free(info->seinfo);
138 delete[] info->gids.gids;
139 free(info);
140 }
141