RASCSI/cpp/shared/network_util.cpp

//---------------------------------------------------------------------------
//
// SCSI Target Emulator PiSCSI
// for Raspberry Pi
//
// Copyright (C) 2023 Uwe Seimet
//
//---------------------------------------------------------------------------

#include "network_util.h"
#include <cstring>
#include <ifaddrs.h>
#include <sys/ioctl.h>
#include <netinet/in.h>
#include <net/if.h>
#include <unistd.h>
#include <netdb.h>
#include <unistd.h>

using namespace std;

bool network_util::IsInterfaceUp(const string& interface)
{
	ifreq ifr = {};
    strncpy(ifr.ifr_name, interface.c_str(), IFNAMSIZ - 1); //NOSONAR Using strncpy is safe
	const int fd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);

	if (!ioctl(fd, SIOCGIFFLAGS, &ifr) && (ifr.ifr_flags & IFF_UP)) {
	    close(fd);
    	return true;
    }

    close(fd);
    return false;
}

set<string, less<>> network_util::GetNetworkInterfaces()
{
	set<string, less<>> network_interfaces;

#ifdef __linux__
	ifaddrs *addrs;
	getifaddrs(&addrs);
	ifaddrs *tmp = addrs;

	while (tmp) {
    	if (const string name = tmp->ifa_name; tmp->ifa_addr && tmp->ifa_addr->sa_family == AF_PACKET &&
    		name != "lo" && name != "piscsi_bridge" && !name.starts_with("dummy") && IsInterfaceUp(name)) {
    		// Only list interfaces that are up
    		network_interfaces.insert(name);
	    }

	    tmp = tmp->ifa_next;
	}

	freeifaddrs(addrs);
#endif

	return network_interfaces;
}

bool network_util::ResolveHostName(const string& host, sockaddr_in *addr)
{
	addrinfo hints = {};
	hints.ai_family = AF_INET;
	hints.ai_socktype = SOCK_STREAM;

	if (addrinfo *result; !getaddrinfo(host.c_str(), nullptr, &hints, &result)) {
		*addr = *reinterpret_cast<sockaddr_in *>(result->ai_addr); //NOSONAR bit_cast is not supported by the bullseye compiler
		freeaddrinfo(result);
		return true;
	}

	return false;
}