Merge "NetlinkListener: eliminate duplicate code"

#define LOG_TAG "NetlinkListener"

#include <cutils/log.h>

#include <cutils/uevent.h>

#include <sysutils/NetlinkListener.h>

#include <sysutils/NetlinkEvent.h>

{

    int socket = cli->getSocket();

    ssize_t count;

    char cred_msg[CMSG_SPACE(sizeof(struct ucred))];

    struct sockaddr_nl snl;

    struct iovec iov = {mBuffer, sizeof(mBuffer)};

    struct msghdr hdr = {&snl, sizeof(snl), &iov, 1, cred_msg, sizeof(cred_msg), 0};

    count = TEMP_FAILURE_RETRY(recvmsg(socket, &hdr, 0));

    count = TEMP_FAILURE_RETRY(uevent_checked_recv(socket, mBuffer, sizeof(mBuffer)));

    if (count < 0) {

        SLOGE("recvmsg failed (%s)", strerror(errno));

        return false;

    }

    if ((snl.nl_groups != 1) || (snl.nl_pid != 0)) {

        SLOGE("ignoring non-kernel netlink multicast message");

        return false;

    }

    struct cmsghdr * cmsg = CMSG_FIRSTHDR(&hdr);

    if (cmsg == NULL || cmsg->cmsg_type != SCM_CREDENTIALS) {

        SLOGE("ignoring message with no sender credentials");

        return false;

    }

    struct ucred * cred = (struct ucred *)CMSG_DATA(cmsg);

    if (cred->uid != 0) {

        SLOGE("ignoring message from non-root UID %d", cred->uid);

        return false;

    }

    NetlinkEvent *evt = new NetlinkEvent();

    if (!evt->decode(mBuffer, count)) {

        SLOGE("Error decoding NetlinkEvent");