libcutils/sockets_unix.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.
 */

#include <cutils/sockets.h>
#include <log/log.h>

#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__)
    struct 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) {
    struct 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));
}

cutils_socket_buffer_t make_cutils_socket_buffer(void* data, size_t length) {
    cutils_socket_buffer_t buffer;
    buffer.iov_base = data;
    buffer.iov_len = length;
    return buffer;
}

ssize_t socket_send_buffers(cutils_socket_t sock,
                            cutils_socket_buffer_t* buffers,
                            size_t num_buffers) {
    return writev(sock, buffers, num_buffers);
}