libsysutils/src/SocketListener.cpp

/*
 * 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 <stdio.h>
#include <errno.h>
#include <stdlib.h>
#include <sys/socket.h>
#include <sys/select.h>
#include <sys/time.h>
#include <sys/types.h>
#include <sys/un.h>

#define LOG_TAG "SocketListener"
#include <cutils/log.h>
#include <cutils/sockets.h>

#include <sysutils/SocketListener.h>
#include <sysutils/SocketClient.h>

SocketListener::SocketListener(const char *socketName, bool listen) {
    mListen = listen;
    mSocketName = socketName;
    mSock = -1;
    pthread_mutex_init(&mClientsLock, NULL);
    mClients = new SocketClientCollection();
}

SocketListener::SocketListener(int socketFd, bool listen) {
    mListen = listen;
    mSocketName = NULL;
    mSock = socketFd;
    pthread_mutex_init(&mClientsLock, NULL);
    mClients = new SocketClientCollection();
}

int SocketListener::startListener() {

    if (!mSocketName && mSock == -1) {
        errno = EINVAL;
        return -1;
    } else if (mSocketName) {
        if ((mSock = android_get_control_socket(mSocketName)) < 0) {
            LOGE("Obtaining file descriptor socket '%s' failed: %s",
                 mSocketName, strerror(errno));
            return -1;
        }
    }

    if (mListen && listen(mSock, 4) < 0) {
        LOGE("Unable to listen on socket (%s)", strerror(errno));
        return -1;
    } else if (!mListen) {
        mClients->push_back(new SocketClient(mSock));
        LOGD("Created phantom client");
    }

    if (pipe(mCtrlPipe))
        return -1;

    if (pthread_create(&mThread, NULL, SocketListener::threadStart, this))
        return -1;

    return 0;
}

int SocketListener::stopListener() {
    char c = 0;

    if (write(mCtrlPipe[1], &c, 1) != 1) {
        LOGE("Error writing to control pipe (%s)", strerror(errno));
        return -1;
    }

    LOGD("Signaled listener thread - waiting for it to die");
    void *ret;
    if (pthread_join(mThread, &ret)) {
        LOGE("Error joining to listener thread (%s)", strerror(errno));
        return -1;
    }
    LOGD("Listener stopped");
    return 0;
}

void *SocketListener::threadStart(void *obj) {
    SocketListener *me = reinterpret_cast<SocketListener *>(obj);

    me->runListener();
    LOGD("Listener thread shutting down");
    pthread_exit(NULL);
    return NULL;
}

void SocketListener::runListener() {

    while(1) {
        SocketClientCollection::iterator it;
        fd_set read_fds;
        struct timeval to;
        int rc = 0;

        to.tv_sec = 60 * 60;
        to.tv_usec = 0;

        int max = 0;

        FD_ZERO(&read_fds);

        if (mListen) {
            max = mSock;
            FD_SET(mSock, &read_fds);
        }

        FD_SET(mCtrlPipe[0], &read_fds);
        if (mCtrlPipe[0] > max)
            max = mCtrlPipe[0];

        pthread_mutex_lock(&mClientsLock);
        for (it = mClients->begin(); it != mClients->end(); ++it) {
            FD_SET((*it)->getSocket(), &read_fds);
            if ((*it)->getSocket() > max)
                max = (*it)->getSocket();
        }
        pthread_mutex_unlock(&mClientsLock);
        
        if ((rc = select(max + 1, &read_fds, NULL, NULL, &to)) < 0) {
            LOGE("select failed (%s)", strerror(errno));
            sleep(1);
            continue;
        } else if (!rc) {
            LOGD("select timeout");
            continue;
        }

        if (FD_ISSET(mCtrlPipe[0], &read_fds)) {
            LOGD("Control message received");
            break;
        }
        if (mListen && FD_ISSET(mSock, &read_fds)) {
            struct sockaddr addr;
            socklen_t alen = sizeof(addr);
            int c;

            if ((c = accept(mSock, &addr, &alen)) < 0) {
                LOGE("accept failed (%s)", strerror(errno));
                sleep(1);
                continue;
            }
            LOGD("SocketListener client connection accepted");
            pthread_mutex_lock(&mClientsLock);
            mClients->push_back(new SocketClient(c));
            pthread_mutex_unlock(&mClientsLock);
        }

        do {
            pthread_mutex_lock(&mClientsLock);
            for (it = mClients->begin(); it != mClients->end(); ++it) {
                int fd = (*it)->getSocket();
                if (FD_ISSET(fd, &read_fds)) {
                    pthread_mutex_unlock(&mClientsLock);
                    if (!onDataAvailable(*it)) {
                        LOGD("SocketListener closing client socket");
                        close(fd);
                        pthread_mutex_lock(&mClientsLock);
                        delete *it;
                        it = mClients->erase(it);
                        pthread_mutex_unlock(&mClientsLock);
                    }
                    FD_CLR(fd, &read_fds);
                    continue;
                }
            }
            pthread_mutex_unlock(&mClientsLock);
        } while (0);
    }
}

void SocketListener::sendBroadcast(int code, char *msg, bool addErrno) {
    pthread_mutex_lock(&mClientsLock);
    SocketClientCollection::iterator i;

    for (i = mClients->begin(); i != mClients->end(); ++i) {
        if ((*i)->sendMsg(code, msg, addErrno)) {
            LOGW("Error sending broadcast (%s)", strerror(errno));
        }
    }
    pthread_mutex_unlock(&mClientsLock);
}

void SocketListener::sendBroadcast(char *msg) {
    pthread_mutex_lock(&mClientsLock);
    SocketClientCollection::iterator i;

    for (i = mClients->begin(); i != mClients->end(); ++i) {
        if ((*i)->sendMsg(msg)) {
            LOGW("Error sending broadcast (%s)", strerror(errno));
        }
    }
    pthread_mutex_unlock(&mClientsLock);
}