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 int debuggable;
67 char* gid_list;
68 int profileable_from_shell = 0;
69 int fields =
70 sscanf(line, "%ms %u %d %ms %ms %ms %d %ld", &info->name, &info->uid,
71 &debuggable, &info->data_dir, &info->seinfo, &gid_list,
72 &profileable_from_shell, &info->version_code);
73
74 // Handle the more complicated gids field and free the temporary string.
75 bool gids_okay = parse_gids(path, line_number, gid_list, info);
76 free(gid_list);
77 if (!gids_okay) return false;
78
79 // Did we see enough fields to be getting on with?
80 // The final fields are optional (and not usually present).
81 if (fields < 6) {
82 ALOGE("%s:%zu: too few fields in line", path, line_number);
83 return false;
84 }
85
86 // Convert integers to bools.
87 info->debuggable = debuggable;
88 info->profileable_from_shell = profileable_from_shell;
89
90 return true;
91 }
92
packagelist_parse_file(const char * path,bool (* callback)(pkg_info *,void *),void * user_data)93 bool packagelist_parse_file(const char* path, bool (*callback)(pkg_info*, void*), void* user_data) {
94 std::unique_ptr<FILE, decltype(&fclose)> fp(fopen(path, "re"), &fclose);
95 if (!fp) {
96 ALOGE("couldn't open '%s': %s", path, strerror(errno));
97 return false;
98 }
99
100 size_t line_number = 0;
101 char* line = nullptr;
102 size_t allocated_length = 0;
103 while (getline(&line, &allocated_length, fp.get()) > 0) {
104 ++line_number;
105 std::unique_ptr<pkg_info, decltype(&packagelist_free)> info(
106 static_cast<pkg_info*>(calloc(1, sizeof(pkg_info))), &packagelist_free);
107 if (!info) {
108 ALOGE("%s:%zu: couldn't allocate pkg_info", path, line_number);
109 return false;
110 }
111
112 if (!parse_line(path, line_number, line, info.get())) return false;
113
114 if (!callback(info.release(), user_data)) break;
115 }
116 free(line);
117 return true;
118 }
119
packagelist_parse(bool (* callback)(pkg_info *,void *),void * user_data)120 bool packagelist_parse(bool (*callback)(pkg_info*, void*), void* user_data) {
121 return packagelist_parse_file("/data/system/packages.list", callback, user_data);
122 }
123
packagelist_free(pkg_info * info)124 void packagelist_free(pkg_info* info) {
125 if (!info) return;
126
127 free(info->name);
128 free(info->data_dir);
129 free(info->seinfo);
130 delete[] info->gids.gids;
131 free(info);
132 }
133