platform_system_core/libcutils/sockets_unix.cpp

116 lines
3.4 KiB
C++

/*
* Copyright (C) 2011 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.
*/
#define LOG_TAG "socket-unix"
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/socket.h>
#include <sys/uio.h>
#include <sys/un.h>
#include <time.h>
#include <unistd.h>
#include <cutils/android_get_control_file.h>
#include <cutils/sockets.h>
#include <log/log.h>
#include "android_get_control_env.h"
#ifndef TEMP_FAILURE_RETRY
#define TEMP_FAILURE_RETRY(exp) (exp) // KISS implementation
#endif
#if defined(__ANDROID__)
/* For the socket trust (credentials) check */
#include <private/android_filesystem_config.h>
#define __android_unused
#else
#define __android_unused __attribute__((__unused__))
#endif
bool socket_peer_is_trusted(int fd __android_unused) {
#if defined(__ANDROID__)
ucred cr;
socklen_t len = sizeof(cr);
int n = getsockopt(fd, SOL_SOCKET, SO_PEERCRED, &cr, &len);
if (n != 0) {
ALOGE("could not get socket credentials: %s\n", strerror(errno));
return false;
}
if ((cr.uid != AID_ROOT) && (cr.uid != AID_SHELL)) {
ALOGE("untrusted userid on other end of socket: userid %d\n", cr.uid);
return false;
}
#endif
return true;
}
int socket_close(int sock) {
return close(sock);
}
int socket_set_receive_timeout(cutils_socket_t sock, int timeout_ms) {
timeval tv;
tv.tv_sec = timeout_ms / 1000;
tv.tv_usec = (timeout_ms % 1000) * 1000;
return setsockopt(sock, SOL_SOCKET, SO_RCVTIMEO, &tv, sizeof(tv));
}
ssize_t socket_send_buffers(cutils_socket_t sock,
const cutils_socket_buffer_t* buffers,
size_t num_buffers) {
if (num_buffers > SOCKET_SEND_BUFFERS_MAX_BUFFERS) {
return -1;
}
iovec iovec_buffers[SOCKET_SEND_BUFFERS_MAX_BUFFERS];
for (size_t i = 0; i < num_buffers; ++i) {
// It's safe to cast away const here; iovec declares non-const
// void* because it's used for both send and receive, but since
// we're only sending, the data won't be modified.
iovec_buffers[i].iov_base = const_cast<void*>(buffers[i].data);
iovec_buffers[i].iov_len = buffers[i].length;
}
return writev(sock, iovec_buffers, num_buffers);
}
int android_get_control_socket(const char* name) {
int fd = __android_get_control_from_env(ANDROID_SOCKET_ENV_PREFIX, name);
if (fd < 0) return fd;
// Compare to UNIX domain socket name, must match!
struct sockaddr_un addr;
socklen_t addrlen = sizeof(addr);
int ret = TEMP_FAILURE_RETRY(getsockname(fd, (struct sockaddr *)&addr, &addrlen));
if (ret < 0) return -1;
char *path = NULL;
if (asprintf(&path, ANDROID_SOCKET_DIR "/%s", name) < 0) return -1;
if (!path) return -1;
int cmp = strcmp(addr.sun_path, path);
free(path);
if (cmp != 0) return -1;
// It is what we think it is
return fd;
}