test

#include <unistd.h>

#include <fcntl.h>

#include <net/if.h>

#include <linux/ethtool.h>

#include <linux/sockios.h>

#include <arpa/inet.h>

#include <sys/socket.h>

#include <sys/ioctl.h>

}

// what the device is: "bond", "bridge", "wireguard" or ""

// the driver of a network device as ethtool names it ("" if unknown)

static std::string linkDriver(const std::string &ifname) {

    int fd = socket(AF_INET, SOCK_DGRAM | SOCK_CLOEXEC, 0);

    if (fd < 0) return "";

    struct ethtool_drvinfo info{};

    info.cmd = ETHTOOL_GDRVINFO;

    struct ifreq ifr{};

    std::strncpy(ifr.ifr_name, ifname.c_str(), IFNAMSIZ - 1);

    ifr.ifr_data = reinterpret_cast<char *>(&info);

    int r = ioctl(fd, SIOCETHTOOL, &ifr);

    ::close(fd);

    return r == 0 ? std::string(info.driver) : "";

}

static std::string linkKind(const std::string &ifname) {

    std::error_code ec;

    const std::string sys = "/sys/class/net/" + ifname;

    std::string line;

    while (std::getline(uevent, line))

        if (trim(line) == "DEVTYPE=wireguard") return "wireguard";

    // a veth pair's end (containers: containerd, docker, nspawn)

    if (linkDriver(ifname) == "veth") return "veth";

    return "";

}

}

bool NetworkManager::deleteUnconfiguredLink(const std::string &ifname, std::string *err) {

    if (findNetDev(ifname) || !interfaceExists(ifname) || linkKind(ifname).empty()) {

    // a veth belongs to a container (containerd & co.), not to syslite

    std::string kind = interfaceExists(ifname) ? linkKind(ifname) : "";

    if (findNetDev(ifname) || kind.empty() || kind == "veth") {

        if (err) *err = "no bond or bridge " + ifname;

        return false;

    }