1 /*
2 * Copyright (C) 2010 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 <poll.h>
18 #include <fcntl.h>
19 #include <string.h>
20 #include <stdlib.h>
21 #include <stdio.h>
22 #include <ctype.h>
23 #include <signal.h>
24 #include <selinux/selinux.h>
25
26 #include <private/android_filesystem_config.h>
27
28 #include "ueventd.h"
29 #include "log.h"
30 #include "util.h"
31 #include "devices.h"
32 #include "ueventd_parser.h"
33
34 static char hardware[32];
35 static unsigned revision = 0;
36
import_kernel_nv(char * name,int in_qemu)37 static void import_kernel_nv(char *name, int in_qemu)
38 {
39 if (*name != '\0') {
40 char *value = strchr(name, '=');
41 if (value != NULL) {
42 *value++ = 0;
43 if (!strcmp(name,"androidboot.hardware"))
44 {
45 strlcpy(hardware, value, sizeof(hardware));
46 }
47 }
48 }
49 }
50
ueventd_main(int argc,char ** argv)51 int ueventd_main(int argc, char **argv)
52 {
53 struct pollfd ufd;
54 int nr;
55 char tmp[32];
56
57 /*
58 * init sets the umask to 077 for forked processes. We need to
59 * create files with exact permissions, without modification by
60 * the umask.
61 */
62 umask(000);
63
64 /* Prevent fire-and-forget children from becoming zombies.
65 * If we should need to wait() for some children in the future
66 * (as opposed to none right now), double-forking here instead
67 * of ignoring SIGCHLD may be the better solution.
68 */
69 signal(SIGCHLD, SIG_IGN);
70
71 open_devnull_stdio();
72 klog_init();
73 #if LOG_UEVENTS
74 /* Ensure we're at a logging level that will show the events */
75 if (klog_get_level() < KLOG_INFO_LEVEL) {
76 klog_set_level(KLOG_INFO_LEVEL);
77 }
78 #endif
79
80 union selinux_callback cb;
81 cb.func_log = log_callback;
82 selinux_set_callback(SELINUX_CB_LOG, cb);
83
84 INFO("starting ueventd\n");
85
86 /* Respect hardware passed in through the kernel cmd line. Here we will look
87 * for androidboot.hardware param in kernel cmdline, and save its value in
88 * hardware[]. */
89 import_kernel_cmdline(0, import_kernel_nv);
90
91 get_hardware_name(hardware, &revision);
92
93 ueventd_parse_config_file("/ueventd.rc");
94
95 snprintf(tmp, sizeof(tmp), "/ueventd.%s.rc", hardware);
96 ueventd_parse_config_file(tmp);
97
98 device_init();
99
100 ufd.events = POLLIN;
101 ufd.fd = get_device_fd();
102
103 while(1) {
104 ufd.revents = 0;
105 nr = poll(&ufd, 1, -1);
106 if (nr <= 0)
107 continue;
108 if (ufd.revents & POLLIN)
109 handle_device_fd();
110 }
111 }
112
get_android_id(const char * id)113 static int get_android_id(const char *id)
114 {
115 unsigned int i;
116 for (i = 0; i < ARRAY_SIZE(android_ids); i++)
117 if (!strcmp(id, android_ids[i].name))
118 return android_ids[i].aid;
119 return -1;
120 }
121
set_device_permission(int nargs,char ** args)122 void set_device_permission(int nargs, char **args)
123 {
124 char *name;
125 char *attr = 0;
126 mode_t perm;
127 uid_t uid;
128 gid_t gid;
129 int prefix = 0;
130 int wildcard = 0;
131 char *endptr;
132 int ret;
133 char *tmp = 0;
134
135 if (nargs == 0)
136 return;
137
138 if (args[0][0] == '#')
139 return;
140
141 name = args[0];
142
143 if (!strncmp(name,"/sys/", 5) && (nargs == 5)) {
144 INFO("/sys/ rule %s %s\n",args[0],args[1]);
145 attr = args[1];
146 args++;
147 nargs--;
148 }
149
150 if (nargs != 4) {
151 ERROR("invalid line ueventd.rc line for '%s'\n", args[0]);
152 return;
153 }
154
155 /* If path starts with mtd@ lookup the mount number. */
156 if (!strncmp(name, "mtd@", 4)) {
157 int n = mtd_name_to_number(name + 4);
158 if (n >= 0)
159 asprintf(&tmp, "/dev/mtd/mtd%d", n);
160 name = tmp;
161 } else {
162 int len = strlen(name);
163 char *wildcard_chr = strchr(name, '*');
164 if ((name[len - 1] == '*') &&
165 (wildcard_chr == (name + len - 1))) {
166 prefix = 1;
167 name[len - 1] = '\0';
168 } else if (wildcard_chr) {
169 wildcard = 1;
170 }
171 }
172
173 perm = strtol(args[1], &endptr, 8);
174 if (!endptr || *endptr != '\0') {
175 ERROR("invalid mode '%s'\n", args[1]);
176 free(tmp);
177 return;
178 }
179
180 ret = get_android_id(args[2]);
181 if (ret < 0) {
182 ERROR("invalid uid '%s'\n", args[2]);
183 free(tmp);
184 return;
185 }
186 uid = ret;
187
188 ret = get_android_id(args[3]);
189 if (ret < 0) {
190 ERROR("invalid gid '%s'\n", args[3]);
191 free(tmp);
192 return;
193 }
194 gid = ret;
195
196 add_dev_perms(name, attr, perm, uid, gid, prefix, wildcard);
197 free(tmp);
198 }
199