platform_system_core/init/ueventd.cpp

174 lines
4.1 KiB
C++

/*
* Copyright (C) 2010 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include <ctype.h>
#include <fcntl.h>
#include <poll.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <base/stringprintf.h>
#include <private/android_filesystem_config.h>
#include <selinux/selinux.h>
#include "ueventd.h"
#include "log.h"
#include "util.h"
#include "devices.h"
#include "ueventd_parser.h"
#include "property_service.h"
int ueventd_main(int argc, char **argv)
{
/*
* init sets the umask to 077 for forked processes. We need to
* create files with exact permissions, without modification by
* the umask.
*/
umask(000);
/* Prevent fire-and-forget children from becoming zombies.
* If we should need to wait() for some children in the future
* (as opposed to none right now), double-forking here instead
* of ignoring SIGCHLD may be the better solution.
*/
signal(SIGCHLD, SIG_IGN);
open_devnull_stdio();
klog_init();
klog_set_level(KLOG_NOTICE_LEVEL);
NOTICE("ueventd started!\n");
selinux_callback cb;
cb.func_log = selinux_klog_callback;
selinux_set_callback(SELINUX_CB_LOG, cb);
char hardware[PROP_VALUE_MAX];
property_get("ro.hardware", hardware);
ueventd_parse_config_file("/ueventd.rc");
ueventd_parse_config_file(android::base::StringPrintf("/ueventd.%s.rc", hardware).c_str());
device_init();
pollfd ufd;
ufd.events = POLLIN;
ufd.fd = get_device_fd();
while (true) {
ufd.revents = 0;
int nr = poll(&ufd, 1, -1);
if (nr <= 0) {
continue;
}
if (ufd.revents & POLLIN) {
handle_device_fd();
}
}
return 0;
}
static int get_android_id(const char *id)
{
unsigned int i;
for (i = 0; i < ARRAY_SIZE(android_ids); i++)
if (!strcmp(id, android_ids[i].name))
return android_ids[i].aid;
return -1;
}
void set_device_permission(int nargs, char **args)
{
char *name;
char *attr = 0;
mode_t perm;
uid_t uid;
gid_t gid;
int prefix = 0;
int wildcard = 0;
char *endptr;
int ret;
char *tmp = 0;
if (nargs == 0)
return;
if (args[0][0] == '#')
return;
name = args[0];
if (!strncmp(name,"/sys/", 5) && (nargs == 5)) {
INFO("/sys/ rule %s %s\n",args[0],args[1]);
attr = args[1];
args++;
nargs--;
}
if (nargs != 4) {
ERROR("invalid line ueventd.rc line for '%s'\n", args[0]);
return;
}
/* If path starts with mtd@ lookup the mount number. */
if (!strncmp(name, "mtd@", 4)) {
int n = mtd_name_to_number(name + 4);
if (n >= 0)
asprintf(&tmp, "/dev/mtd/mtd%d", n);
name = tmp;
} else {
int len = strlen(name);
char *wildcard_chr = strchr(name, '*');
if ((name[len - 1] == '*') &&
(wildcard_chr == (name + len - 1))) {
prefix = 1;
name[len - 1] = '\0';
} else if (wildcard_chr) {
wildcard = 1;
}
}
perm = strtol(args[1], &endptr, 8);
if (!endptr || *endptr != '\0') {
ERROR("invalid mode '%s'\n", args[1]);
free(tmp);
return;
}
ret = get_android_id(args[2]);
if (ret < 0) {
ERROR("invalid uid '%s'\n", args[2]);
free(tmp);
return;
}
uid = ret;
ret = get_android_id(args[3]);
if (ret < 0) {
ERROR("invalid gid '%s'\n", args[3]);
free(tmp);
return;
}
gid = ret;
add_dev_perms(name, attr, perm, uid, gid, prefix, wildcard);
free(tmp);
}