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/*
* Copyright (C) 2007 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 <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <dirent.h>
#include <utime.h>
#include <unistd.h>
#include <errno.h>
#include <private/android_filesystem_config.h>
#include <selinux/android.h>
#include "sysdeps.h"
#define TRACE_TAG TRACE_SYNC
#include "adb.h"
#include "file_sync_service.h"
/* TODO: use fs_config to configure permissions on /data */
static bool is_on_system(const char *name) {
const char *SYSTEM = "/system/";
return (strncmp(SYSTEM, name, strlen(SYSTEM)) == 0);
}
static int mkdirs(char *name)
{
int ret;
char *x = name + 1;
uid_t uid = -1;
gid_t gid = -1;
unsigned int mode = 0775;
uint64_t cap = 0;
if(name[0] != '/') return -1;
for(;;) {
x = adb_dirstart(x);
if(x == 0) return 0;
*x = 0;
if (is_on_system(name)) {
fs_config(name, 1, &uid, &gid, &mode, &cap);
}
ret = adb_mkdir(name, mode);
if((ret < 0) && (errno != EEXIST)) {
D("mkdir(\"%s\") -> %s\n", name, strerror(errno));
*x = '/';
return ret;
} else if(ret == 0) {
ret = chown(name, uid, gid);
if (ret < 0) {
*x = '/';
return ret;
}
selinux_android_restorecon(name, 0);
}
*x++ = '/';
}
return 0;
}
static int do_stat(int s, const char *path)
{
syncmsg msg;
struct stat st;
msg.stat.id = ID_STAT;
if(lstat(path, &st)) {
msg.stat.mode = 0;
msg.stat.size = 0;
msg.stat.time = 0;
} else {
msg.stat.mode = htoll(st.st_mode);
msg.stat.size = htoll(st.st_size);
msg.stat.time = htoll(st.st_mtime);
}
return writex(s, &msg.stat, sizeof(msg.stat));
}
static int do_list(int s, const char *path)
{
DIR *d;
struct dirent *de;
struct stat st;
syncmsg msg;
int len;
char tmp[1024 + 256 + 1];
char *fname;
len = strlen(path);
memcpy(tmp, path, len);
tmp[len] = '/';
fname = tmp + len + 1;
msg.dent.id = ID_DENT;
d = opendir(path);
if(d == 0) goto done;
while((de = readdir(d))) {
int len = strlen(de->d_name);
/* not supposed to be possible, but
if it does happen, let's not buffer overrun */
if(len > 256) continue;
strcpy(fname, de->d_name);
if(lstat(tmp, &st) == 0) {
msg.dent.mode = htoll(st.st_mode);
msg.dent.size = htoll(st.st_size);
msg.dent.time = htoll(st.st_mtime);
msg.dent.namelen = htoll(len);
if(writex(s, &msg.dent, sizeof(msg.dent)) ||
writex(s, de->d_name, len)) {
closedir(d);
return -1;
}
}
}
closedir(d);
done:
msg.dent.id = ID_DONE;
msg.dent.mode = 0;
msg.dent.size = 0;
msg.dent.time = 0;
msg.dent.namelen = 0;
return writex(s, &msg.dent, sizeof(msg.dent));
}
static int fail_message(int s, const char *reason)
{
syncmsg msg;
int len = strlen(reason);
D("sync: failure: %s\n", reason);
msg.data.id = ID_FAIL;
msg.data.size = htoll(len);
if(writex(s, &msg.data, sizeof(msg.data)) ||
writex(s, reason, len)) {
return -1;
} else {
return 0;
}
}
static int fail_errno(int s)
{
return fail_message(s, strerror(errno));
}
static int handle_send_file(int s, char *path, uid_t uid,
gid_t gid, mode_t mode, char *buffer, bool do_unlink)
{
syncmsg msg;
unsigned int timestamp = 0;
int fd;
fd = adb_open_mode(path, O_WRONLY | O_CREAT | O_EXCL, mode);
if(fd < 0 && errno == ENOENT) {
if(mkdirs(path) != 0) {
if(fail_errno(s))
return -1;
fd = -1;
} else {
fd = adb_open_mode(path, O_WRONLY | O_CREAT | O_EXCL, mode);
}
}
if(fd < 0 && errno == EEXIST) {
fd = adb_open_mode(path, O_WRONLY, mode);
}
if(fd < 0) {
if(fail_errno(s))
return -1;
fd = -1;
} else {
if(fchown(fd, uid, gid) != 0) {
fail_errno(s);
errno = 0;
}
/*
* fchown clears the setuid bit - restore it if present.
* Ignore the result of calling fchmod. It's not supported
* by all filesystems. b/12441485
*/
fchmod(fd, mode);
}
for(;;) {
unsigned int len;
if(readx(s, &msg.data, sizeof(msg.data)))
goto fail;
if(msg.data.id != ID_DATA) {
if(msg.data.id == ID_DONE) {
timestamp = ltohl(msg.data.size);
break;
}
fail_message(s, "invalid data message");
goto fail;
}
len = ltohl(msg.data.size);
if(len > SYNC_DATA_MAX) {
fail_message(s, "oversize data message");
goto fail;
}
if(readx(s, buffer, len))
goto fail;
if(fd < 0)
continue;
if(writex(fd, buffer, len)) {
int saved_errno = errno;
adb_close(fd);
if (do_unlink) adb_unlink(path);
fd = -1;
errno = saved_errno;
if(fail_errno(s)) return -1;
}
}
if(fd >= 0) {
struct utimbuf u;
adb_close(fd);
selinux_android_restorecon(path, 0);
u.actime = timestamp;
u.modtime = timestamp;
utime(path, &u);
msg.status.id = ID_OKAY;
msg.status.msglen = 0;
if(writex(s, &msg.status, sizeof(msg.status)))
return -1;
}
return 0;
fail:
if(fd >= 0)
adb_close(fd);
if (do_unlink) adb_unlink(path);
return -1;
}
#ifdef HAVE_SYMLINKS
static int handle_send_link(int s, char *path, char *buffer)
{
syncmsg msg;
unsigned int len;
int ret;
if(readx(s, &msg.data, sizeof(msg.data)))
return -1;
if(msg.data.id != ID_DATA) {
fail_message(s, "invalid data message: expected ID_DATA");
return -1;
}
len = ltohl(msg.data.size);
if(len > SYNC_DATA_MAX) {
fail_message(s, "oversize data message");
return -1;
}
if(readx(s, buffer, len))
return -1;
ret = symlink(buffer, path);
if(ret && errno == ENOENT) {
if(mkdirs(path) != 0) {
fail_errno(s);
return -1;
}
ret = symlink(buffer, path);
}
if(ret) {
fail_errno(s);
return -1;
}
if(readx(s, &msg.data, sizeof(msg.data)))
return -1;
if(msg.data.id == ID_DONE) {
msg.status.id = ID_OKAY;
msg.status.msglen = 0;
if(writex(s, &msg.status, sizeof(msg.status)))
return -1;
} else {
fail_message(s, "invalid data message: expected ID_DONE");
return -1;
}
return 0;
}
#endif /* HAVE_SYMLINKS */
static int do_send(int s, char *path, char *buffer)
{
char *tmp;
unsigned int mode;
int is_link, ret;
bool do_unlink;
tmp = strrchr(path,',');
if(tmp) {
*tmp = 0;
errno = 0;
mode = strtoul(tmp + 1, NULL, 0);
#ifndef HAVE_SYMLINKS
is_link = 0;
#else
is_link = S_ISLNK((mode_t) mode);
#endif
mode &= 0777;
}
if(!tmp || errno) {
mode = 0644;
is_link = 0;
do_unlink = true;
} else {
struct stat st;
/* Don't delete files before copying if they are not "regular" */
do_unlink = lstat(path, &st) || S_ISREG(st.st_mode) || S_ISLNK(st.st_mode);
if (do_unlink) {
adb_unlink(path);
}
}
#ifdef HAVE_SYMLINKS
if(is_link)
ret = handle_send_link(s, path, buffer);
else {
#else
{
#endif
uid_t uid = -1;
gid_t gid = -1;
uint64_t cap = 0;
/* copy user permission bits to "group" and "other" permissions */
mode |= ((mode >> 3) & 0070);
mode |= ((mode >> 3) & 0007);
tmp = path;
if(*tmp == '/') {
tmp++;
}
if (is_on_system(path)) {
fs_config(tmp, 0, &uid, &gid, &mode, &cap);
}
ret = handle_send_file(s, path, uid, gid, mode, buffer, do_unlink);
}
return ret;
}
static int do_recv(int s, const char *path, char *buffer)
{
syncmsg msg;
int fd, r;
fd = adb_open(path, O_RDONLY);
if(fd < 0) {
if(fail_errno(s)) return -1;
return 0;
}
msg.data.id = ID_DATA;
for(;;) {
r = adb_read(fd, buffer, SYNC_DATA_MAX);
if(r <= 0) {
if(r == 0) break;
if(errno == EINTR) continue;
r = fail_errno(s);
adb_close(fd);
return r;
}
msg.data.size = htoll(r);
if(writex(s, &msg.data, sizeof(msg.data)) ||
writex(s, buffer, r)) {
adb_close(fd);
return -1;
}
}
adb_close(fd);
msg.data.id = ID_DONE;
msg.data.size = 0;
if(writex(s, &msg.data, sizeof(msg.data))) {
return -1;
}
return 0;
}
void file_sync_service(int fd, void *cookie)
{
syncmsg msg;
char name[1025];
unsigned namelen;
char *buffer = malloc(SYNC_DATA_MAX);
if(buffer == 0) goto fail;
for(;;) {
D("sync: waiting for command\n");
if(readx(fd, &msg.req, sizeof(msg.req))) {
fail_message(fd, "command read failure");
break;
}
namelen = ltohl(msg.req.namelen);
if(namelen > 1024) {
fail_message(fd, "invalid namelen");
break;
}
if(readx(fd, name, namelen)) {
fail_message(fd, "filename read failure");
break;
}
name[namelen] = 0;
msg.req.namelen = 0;
D("sync: '%s' '%s'\n", (char*) &msg.req, name);
switch(msg.req.id) {
case ID_STAT:
if(do_stat(fd, name)) goto fail;
break;
case ID_LIST:
if(do_list(fd, name)) goto fail;
break;
case ID_SEND:
if(do_send(fd, name, buffer)) goto fail;
break;
case ID_RECV:
if(do_recv(fd, name, buffer)) goto fail;
break;
case ID_QUIT:
goto fail;
default:
fail_message(fd, "unknown command");
goto fail;
}
}
fail:
if(buffer != 0) free(buffer);
D("sync: done\n");
adb_close(fd);
}