Question

我对ioctl有疑问（我认为）。

该软件是一个debian软件包，它安装在机器的启动过程中，并在此之后立即启动。该软件通过使用/ etc / network / interfaces建立网络。 IP和网络掩码将被写入interfaces配置文件，路由通过interfaces配置文件中的up命令添加。

# CONFIG_MARKER eth0
auto eth0
iface eth0 inet static
address 192.168.0.237
netmask 255.255.255.0
up route add -net 192.168.0.0 netmask 255.255.255.0 gateway 192.168.0.126 dev eth0
down route del -net 192.168.0.0 netmask 255.255.255.0 gateway 192.168.0.126 dev eth0
up route add default gateway 192.168.0.126 dev eth0
down route del default gateway 192.168.0.126 dev eth0
# CONFIG_MARKER eth0

# CONFIG_MARKER prp1
auto prp1
iface prp1 inet static
address 192.168.20.237
netmask 255.255.255.0
up route add -net 192.168.20.0 netmask 255.255.255.0 gateway 192.168.20.1 dev prp1
down route del -net 192.168.20.0 netmask 255.255.255.0 gateway 192.168.20.1 dev prp1

创建配置文件后，软件使用ifdown和ifup启动已设置的接口。（因此每个接口首先在接口配置文件中设置，然后通过ifup启动，因此一个接口配置然后启动，然后下一个接口配置并启动...）

现在当我使用一个使用ioctl读取接口信息的函数（命令行）时出现问题，在该调用之后，路由表将为空（或者更确切地说，添加了手动[在接口配置文件中的via up命令]路线将会消失。）

该函数只从查询接口的套接字上打开的文件描述符中读取数据，然后不会设置数据。

完全出乎意料的是当删除路由后，我手动（从命令行）调用ifdown和接口上的ifup以及使用ioctl调用该函数（启动时会删除已配置的路由）删除路线。

有人能指出我可能会遇到什么问题吗？（接口eth0是一个服务接口，例如网站的调用。接口prp1是一个虚拟接口，它通过PRP包装2个真实接口[eth1和eth2 unconfigured]。还有一些SCL设置正在进行，里面使用ioctl进行接口查询。我确信，IEC61850通信设置不应该归咎于所描述的行为。）

修改

根据请求，导致问题的函数的代码：

NetworkInterface::NicParameter NetworkHelper::getNicParameter(
        const std::string& ifaceName) {

    NetworkInterface::NicParameter nicParam;

    nicParam.ifaceName  = ifaceName;
    nicParam.opState    = getOperationalState(ifaceName);
    nicParam.opMode     = getOperationalMode(ifaceName);
    nicParam.linkStatus = getLinkStatus(ifaceName);
    nicParam.speed      = getSpeed(ifaceName);

    // Get the IP address of the current interface.
    int fd = socket(AF_INET, SOCK_DGRAM, 0);
    struct ifreq ifr;
    ifr.ifr_addr.sa_family = AF_INET;

    // Copy the interface name in the ifreq structure.
    strncpy(ifr.ifr_name, ifaceName.c_str(), IFNAMSIZ - 1);
    // get the ip address.
    ioctl(fd, SIOCGIFADDR, &ifr);
    nicParam.ipAddress
        = inet_ntoa(((struct sockaddr_in *)&ifr.ifr_addr)->sin_addr);

    // Get the netmask of the current interface.
    ioctl(fd, SIOCGIFNETMASK, &ifr);
    nicParam.netmask
        = inet_ntoa(((struct sockaddr_in *)&ifr.ifr_addr)->sin_addr);

    // Get the gateway address of the current interface.
    ioctl(fd, SIOCGIFDSTADDR, &ifr);
    nicParam.gateway = inet_ntoa(((struct sockaddr_in *)&ifr.ifr_addr)->sin_addr);

    // Get the broadcast address of the current interface.
    ioctl(fd, SIOCSIFBRDADDR, &ifr);
    nicParam.broadcastAddress
            = inet_ntoa(((struct sockaddr_in *)&ifr.ifr_addr)->sin_addr);

    // Get the broadcast address of the current interface.
    struct ifreq req;
    strcpy(req.ifr_name, ifaceName.c_str());
    char macAddress[18]; // 17 characters + null terminator
                         // example: 01:02:03:04:05:06
    if (ioctl(fd, SIOCGIFHWADDR, &req) != -1) {
        uint8_t *mac = reinterpret_cast<uint8_t *>(
            req.ifr_ifru.ifru_hwaddr.sa_data);
        sprintf(macAddress, "%02X:%02X:%02X:%02X:%02X:%02X",
                mac[0], mac[1], mac[2], mac[3], mac[4], mac[5]);
    }
    nicParam.macAddress = std::string(macAddress);

    close(fd);

    // Get the total number of received bytes.
    int returnValue;
    std::string procNetDev = "cat /proc/net/dev | grep " + ifaceName;
    nicParam.receivedPackets.numBytes = OsHelper::executeCommandInt(
        procNetDev + " | awk '{print $2}'", returnValue);

    // Get the total number of received packets.
    // Include the number of faulty and dropped packets.
    nicParam.receivedPackets.numPackets = OsHelper::executeCommandInt(
        procNetDev + " | awk '{print $3}'", returnValue);
    nicParam.receivedPackets.numErrors = OsHelper::executeCommandInt(
        procNetDev + " | awk '{print $4}'", returnValue);
    nicParam.receivedPackets.numDroppedPackets = OsHelper::executeCommandInt(
        procNetDev + " | awk '{print $5}'", returnValue);

    // Get the total number of transmitted bytes.
    nicParam.transmittedPackets.numBytes = OsHelper::executeCommandInt(
        procNetDev + " | awk '{print $10}'", returnValue);

    // Get the total number of transmitted packets.
    // Include the number of faulty and dropped packets.
    nicParam.transmittedPackets.numPackets = OsHelper::executeCommandInt(
        procNetDev + " | awk '{print $11}'", returnValue);
    nicParam.transmittedPackets.numErrors = OsHelper::executeCommandInt(
        procNetDev + " | awk '{print $12}'", returnValue);
    nicParam.transmittedPackets.numDroppedPackets = OsHelper::executeCommandInt(
        procNetDev + " | awk '{print $13}'", returnValue);

    // Check if DHCP is enabled or not.
    returnValue = 0;
    OsHelper::executeCommand("cat /etc/network/interfaces | grep -v '#' | grep "
        + ifaceName + " | grep dhcp", returnValue);
    if (returnValue == 0)
        nicParam.dhcpState = "enabled";
    else
        nicParam.dhcpState = "disabled";

    return nicParam;
}

广播没有正确检索，其他一些功能真的打电话......不要介意！

Answer 1

所以我发现了我的问题...... 这是一个有点令人尴尬的错误。

在该功能中，您将找到“ioctl（fd，SIOCSIFBRDADDR，＆amp; ifr）;”当在一行中看到没有所有其他调用时，明确地“设置”一个参数而不是检索它（广播地址siocS ...而不是siocG ......）。并且在接口wiull上设置一些东西会导致路由显然被删除，因为NIC改变了，路由将是错误的。

感谢阅读。

ioctl让路线消失

修改

1 个答案: