platform_system_core/init/util.c

302 lines
7 KiB
C
Raw Normal View History

/*
* Copyright (C) 2008 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 <stdarg.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <fcntl.h>
#include <ctype.h>
#include <errno.h>
#include <time.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/un.h>
/* for ANDROID_SOCKET_* */
#include <cutils/sockets.h>
#include <private/android_filesystem_config.h>
#include "init.h"
static int log_fd = -1;
/* Inital log level before init.rc is parsed and this this is reset. */
static int log_level = LOG_DEFAULT_LEVEL;
void log_set_level(int level) {
log_level = level;
}
void log_init(void)
{
static const char *name = "/dev/__kmsg__";
if (mknod(name, S_IFCHR | 0600, (1 << 8) | 11) == 0) {
log_fd = open(name, O_WRONLY);
fcntl(log_fd, F_SETFD, FD_CLOEXEC);
unlink(name);
}
}
#define LOG_BUF_MAX 512
void log_write(int level, const char *fmt, ...)
{
char buf[LOG_BUF_MAX];
va_list ap;
if (level > log_level) return;
if (log_fd < 0) return;
va_start(ap, fmt);
vsnprintf(buf, LOG_BUF_MAX, fmt, ap);
buf[LOG_BUF_MAX - 1] = 0;
va_end(ap);
write(log_fd, buf, strlen(buf));
}
/*
* android_name_to_id - returns the integer uid/gid associated with the given
* name, or -1U on error.
*/
static unsigned int android_name_to_id(const char *name)
{
struct android_id_info *info = android_ids;
unsigned int n;
for (n = 0; n < android_id_count; n++) {
if (!strcmp(info[n].name, name))
return info[n].aid;
}
return -1U;
}
/*
* decode_uid - decodes and returns the given string, which can be either the
* numeric or name representation, into the integer uid or gid. Returns -1U on
* error.
*/
unsigned int decode_uid(const char *s)
{
unsigned int v;
if (!s || *s == '\0')
return -1U;
if (isalpha(s[0]))
return android_name_to_id(s);
errno = 0;
v = (unsigned int) strtoul(s, 0, 0);
if (errno)
return -1U;
return v;
}
/*
* create_socket - creates a Unix domain socket in ANDROID_SOCKET_DIR
* ("/dev/socket") as dictated in init.rc. This socket is inherited by the
* daemon. We communicate the file descriptor's value via the environment
* variable ANDROID_SOCKET_ENV_PREFIX<name> ("ANDROID_SOCKET_foo").
*/
int create_socket(const char *name, int type, mode_t perm, uid_t uid, gid_t gid)
{
struct sockaddr_un addr;
int fd, ret;
fd = socket(PF_UNIX, type, 0);
if (fd < 0) {
ERROR("Failed to open socket '%s': %s\n", name, strerror(errno));
return -1;
}
memset(&addr, 0 , sizeof(addr));
addr.sun_family = AF_UNIX;
snprintf(addr.sun_path, sizeof(addr.sun_path), ANDROID_SOCKET_DIR"/%s",
name);
ret = unlink(addr.sun_path);
if (ret != 0 && errno != ENOENT) {
ERROR("Failed to unlink old socket '%s': %s\n", name, strerror(errno));
goto out_close;
}
ret = bind(fd, (struct sockaddr *) &addr, sizeof (addr));
if (ret) {
ERROR("Failed to bind socket '%s': %s\n", name, strerror(errno));
goto out_unlink;
}
chown(addr.sun_path, uid, gid);
chmod(addr.sun_path, perm);
INFO("Created socket '%s' with mode '%o', user '%d', group '%d'\n",
addr.sun_path, perm, uid, gid);
return fd;
out_unlink:
unlink(addr.sun_path);
out_close:
close(fd);
return -1;
}
/* reads a file, making sure it is terminated with \n \0 */
void *read_file(const char *fn, unsigned *_sz)
{
char *data;
int sz;
int fd;
data = 0;
fd = open(fn, O_RDONLY);
if(fd < 0) return 0;
sz = lseek(fd, 0, SEEK_END);
if(sz < 0) goto oops;
if(lseek(fd, 0, SEEK_SET) != 0) goto oops;
data = (char*) malloc(sz + 2);
if(data == 0) goto oops;
if(read(fd, data, sz) != sz) goto oops;
close(fd);
data[sz] = '\n';
data[sz+1] = 0;
if(_sz) *_sz = sz;
return data;
oops:
close(fd);
if(data != 0) free(data);
return 0;
}
void list_init(struct listnode *node)
{
node->next = node;
node->prev = node;
}
void list_add_tail(struct listnode *head, struct listnode *item)
{
item->next = head;
item->prev = head->prev;
head->prev->next = item;
head->prev = item;
}
void list_remove(struct listnode *item)
{
item->next->prev = item->prev;
item->prev->next = item->next;
}
#define MAX_MTD_PARTITIONS 16
static struct {
char name[16];
int number;
} mtd_part_map[MAX_MTD_PARTITIONS];
static int mtd_part_count = -1;
static void find_mtd_partitions(void)
{
int fd;
char buf[1024];
char *pmtdbufp;
ssize_t pmtdsize;
int r;
fd = open("/proc/mtd", O_RDONLY);
if (fd < 0)
return;
buf[sizeof(buf) - 1] = '\0';
pmtdsize = read(fd, buf, sizeof(buf) - 1);
pmtdbufp = buf;
while (pmtdsize > 0) {
int mtdnum, mtdsize, mtderasesize;
char mtdname[16];
mtdname[0] = '\0';
mtdnum = -1;
r = sscanf(pmtdbufp, "mtd%d: %x %x %15s",
&mtdnum, &mtdsize, &mtderasesize, mtdname);
if ((r == 4) && (mtdname[0] == '"')) {
char *x = strchr(mtdname + 1, '"');
if (x) {
*x = 0;
}
INFO("mtd partition %d, %s\n", mtdnum, mtdname + 1);
if (mtd_part_count < MAX_MTD_PARTITIONS) {
strcpy(mtd_part_map[mtd_part_count].name, mtdname + 1);
mtd_part_map[mtd_part_count].number = mtdnum;
mtd_part_count++;
} else {
ERROR("too many mtd partitions\n");
}
}
while (pmtdsize > 0 && *pmtdbufp != '\n') {
pmtdbufp++;
pmtdsize--;
}
if (pmtdsize > 0) {
pmtdbufp++;
pmtdsize--;
}
}
close(fd);
}
int mtd_name_to_number(const char *name)
{
int n;
if (mtd_part_count < 0) {
mtd_part_count = 0;
find_mtd_partitions();
}
for (n = 0; n < mtd_part_count; n++) {
if (!strcmp(name, mtd_part_map[n].name)) {
return mtd_part_map[n].number;
}
}
return -1;
}
/*
* gettime() - returns the time in seconds of the system's monotonic clock or
* zero on error.
*/
time_t gettime(void)
{
struct timespec ts;
int ret;
ret = clock_gettime(CLOCK_MONOTONIC, &ts);
if (ret < 0) {
ERROR("clock_gettime(CLOCK_MONOTONIC) failed: %s\n", strerror(errno));
return 0;
}
return ts.tv_sec;
}