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dvmhost/src/common/network/viface/VIFace.cpp

703 lines
21 KiB

// SPDX-License-Identifier: GPL-2.0-only
/*
* Digital Voice Modem - Common Library
* GPLv2 Open Source. Use is subject to license terms.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* Copyright (C) 2024 Bryan Biedenkapp, N2PLL
*
*/
#include "Defines.h"
#include "network/viface/VIFace.h"
#include "Log.h"
#include "Utils.h"
using namespace network;
using namespace network::viface;
#include <stdexcept>
#include <sstream>
#include <fstream>
#include <iomanip>
#include <cassert>
#include <cstring>
#include <cerrno>
#include <unistd.h>
#include <fcntl.h>
#include <dirent.h>
#include <arpa/inet.h>
#include <sys/select.h>
#include <sys/epoll.h>
#include <sys/ioctl.h>
#include <sys/socket.h>
#include <linux/if.h>
#include <linux/if_tun.h>
#include <linux/if_arp.h>
#include <ifaddrs.h>
// ---------------------------------------------------------------------------
// Constants
// ---------------------------------------------------------------------------
#define DEFAULT_MTU_SIZE 496
// ---------------------------------------------------------------------------
// Static Class Members
// ---------------------------------------------------------------------------
uint32_t VIFace::m_idSeq = 0U;
// ---------------------------------------------------------------------------
// Global Functions
// ---------------------------------------------------------------------------
/**
* @brief Parses a string MAC address into bytes.
* @param[out] buffer Containing MAC address bytes.
* @param mac MAC address.
* @returns uint8_t*
*/
void parseMAC(uint8_t* buffer, std::string const& mac)
{
assert(buffer != nullptr);
uint32_t bytes[6U];
int scans = sscanf(mac.c_str(), "%02x:%02x:%02x:%02x:%02x:%02x", &bytes[0U], &bytes[1U], &bytes[2U], &bytes[3U], &bytes[4U], &bytes[5U]);
if (scans != 6) {
return;
}
for (uint8_t i = 0U; i < 6U; i++)
buffer[i] = (uint8_t)(bytes[i] & 0xFFU);
}
/**
* @brief Helper routine to hook the virtual interface.
* @param name Name of the virtual interface.
* @param queues
*/
void hookVirtualInterface(std::string name, struct viface_queues* queues)
{
int fd = -1;
// creates Tx/Rx sockets and allocates queues
int i = 0;
for (i = 0; i < 2; i++) {
// creates the socket
fd = socket(AF_PACKET, SOCK_RAW, htons(ETH_P_ALL));
if (fd < 0) {
LogError(LOG_NET, "Unable to create the Tx/Rx socket channel %s, queue: %d, err: %d, error: %s", name.c_str(), i, errno, strerror(errno));
goto hookErr; // bryanb: no good very bad way to handle this -- but if its good enough for the Linux kernel its good enough for us right? this is easiset way to clean up quickly...
}
struct ifreq ifr;
memset(&ifr, 0, sizeof(ifr));
strncpy(ifr.ifr_name, name.c_str(), IFNAMSIZ - 1);
// obtains the network index number
if (ioctl(fd, SIOCGIFINDEX, &ifr) != 0) {
LogError(LOG_NET, "Unable to get network index number %s, queue: %d, err: %d, error: %s", name.c_str(), i, errno, strerror(errno));
goto hookErr; // bryanb: no good very bad way to handle this -- but if its good enough for the Linux kernel its good enough for us right? this is easiset way to clean up quickly...
}
struct sockaddr_ll socket_addr;
memset(&socket_addr, 0, sizeof(struct sockaddr_ll));
socket_addr.sll_family = AF_PACKET;
socket_addr.sll_protocol = htons(ETH_P_ALL);
socket_addr.sll_ifindex = ifr.ifr_ifindex;
// binds the socket to the 'socket_addr' address
if (bind(fd, (struct sockaddr*) &socket_addr, sizeof(socket_addr)) != 0) {
LogError(LOG_NET, "Unable to bind the Tx/Rx socket channel to the network interface %s, queue: %d, err: %d, error: %s", name.c_str(), i, errno, strerror(errno));
goto hookErr; // bryanb: no good very bad way to handle this -- but if its good enough for the Linux kernel its good enough for us right? this is easiset way to clean up quickly...
}
((int *)queues)[i] = fd;
}
return;
hookErr:
// Rollback close file descriptors
for (--i; i >= 0; i--) {
if (close(((int *)queues)[i]) < 0) {
LogError(LOG_NET, "Unable to close a Rx/Tx socket %s, queue: %d, err: %d, error: %s", name.c_str(), i, errno, strerror(errno));
}
}
throw std::runtime_error("Failed to hook virtual network interface.");
}
/**
* @brief Helper routine to allocate and create a virtual network inteface.
* @param name Name of the virtual interface.
* @param tap Tap device (default, true) or Tun device (false).
* @param queues
* @returns std::string
*/
std::string allocateVirtualInterface(std::string name, bool tap, struct viface_queues* queues)
{
int fd = -1;
/*
* create structure for ioctl call
* Flags: IFF_TAP - TAP device (layer 2, ethernet frame)
* IFF_TUN - TUN device (layer 3, IP packet)
* IFF_NO_PI - Do not provide packet information
* IFF_MULTI_QUEUE - Create a queue of multiqueue device
*/
struct ifreq ifr;
memset(&ifr, 0, sizeof(ifr));
ifr.ifr_flags = IFF_NO_PI | IFF_MULTI_QUEUE;
if (tap) {
ifr.ifr_flags |= IFF_TAP;
} else {
ifr.ifr_flags |= IFF_TUN;
}
strncpy(ifr.ifr_name, name.c_str(), IFNAMSIZ - 1);
// allocate queues
int i = 0;
for (i = 0; i < 2; i++) {
// open TUN/TAP device
fd = open("/dev/net/tun", O_RDWR | O_NONBLOCK);
if (fd < 0) {
LogError(LOG_NET, "Unable to open TUN/TAP device %s, queue: %d, err: %d, error: %s", name.c_str(), i, errno, strerror(errno));
goto allocErr; // bryanb: no good very bad way to handle this -- but if its good enough for the Linux kernel its good enough for us right? this is easiset way to clean up quickly...
}
// register a network device with the kernel
if (ioctl(fd, TUNSETIFF, (void *)&ifr) != 0) {
LogError(LOG_NET, "Unable to register a TUN/TAP device %s, queue: %d, err: %d, error: %s", name.c_str(), i, errno, strerror(errno));
if (close(fd) < 0) {
LogError(LOG_NET, "Unable to close a TUN/TAP device %s, queue: %d, err: %d, error: %s", name.c_str(), i, errno, strerror(errno));
}
goto allocErr; // bryanb: no good very bad way to handle this -- but if its good enough for the Linux kernel its good enough for us right? this is easiset way to clean up quickly...
}
((int *)queues)[i] = fd;
}
return std::string(ifr.ifr_name);
allocErr:
// rollback close file descriptors
for (--i; i >= 0; i--) {
if (close(((int *)queues)[i]) < 0) {
LogError(LOG_NET, "Unable to close a TUN/TAP device %s, queue: %d, err: %d, error: %s", name.c_str(), i, errno, strerror(errno));
}
}
throw std::runtime_error("Failed to allocate virtual network interface.");
}
/**
* @brief
* @param sockfd
* @param name
* @param ifr
*/
void readVIFlags(int sockfd, std::string name, struct ifreq& ifr)
{
// prepare communication structure
::memset(&ifr, 0, sizeof(struct ifreq));
// set interface name
strncpy(ifr.ifr_name, name.c_str(), IFNAMSIZ - 1);
// read interface flags
if (ioctl(sockfd, SIOCGIFFLAGS, &ifr) != 0) {
LogError(LOG_NET, "Unable to read virtual interface flags %s, err: %d, error: %s", name.c_str(), errno, strerror(errno));
}
}
/**
* @brief
* @param name
* @param size
* @return uint
*/
uint32_t readMTU(std::string name, size_t size)
{
int fd = -1, nread = -1;
char buffer[size + 1];
// opens MTU file
fd = open(("/sys/class/net/" + name + "/mtu").c_str(), O_RDONLY | O_NONBLOCK);
if (fd < 0) {
LogError(LOG_NET, "Unable to open MTU file for virtual interface %s, err: %d, error: %s", name.c_str(), errno, strerror(errno));
goto readMTUErr; // bryanb: no good very bad way to handle this -- but if its good enough for the Linux kernel its good enough for us right? this is easiset way to clean up quickly...
}
// reads MTU value
nread = read(fd, buffer, size);
buffer[size] = '\0';
// Handles errors
if (nread == -1) {
LogError(LOG_NET, "Unable to read MTU for virtual interface %s, err: %d, error: %s", name.c_str(), errno, strerror(errno));
goto readMTUErr; // bryanb: no good very bad way to handle this -- but if its good enough for the Linux kernel its good enough for us right? this is easiset way to clean up quickly...
}
if (close(fd) < 0) {
LogError(LOG_NET, "Unable to close MTU file for virtual interface %s, err: %d, error: %s", name.c_str(), errno, strerror(errno));
goto readMTUErr; // bryanb: no good very bad way to handle this -- but if its good enough for the Linux kernel its good enough for us right? this is easiset way to clean up quickly...
}
return strtoul(buffer, nullptr, 10);
readMTUErr:
// rollback close file descriptor
close(fd);
throw std::runtime_error("Failed to read virtual network interface MTU.");
}
// ---------------------------------------------------------------------------
// Public Class Members
// ---------------------------------------------------------------------------
/* Initializes a new instance of the VIFace class. */
VIFace::VIFace(std::string name, bool tap, int id) :
m_ksFd(-1),
m_epollFd(-1),
m_mac(),
m_ipv4Address("192.168.1.254"),
m_ipv4Netmask("255.255.255.0"),
m_ipv4Broadcast("192.168.1.255"),
m_mtu(DEFAULT_MTU_SIZE)
{
// check name length
if (name.length() >= IFNAMSIZ) {
throw std::invalid_argument("Virtual interface name too long.");
}
// create queues
struct viface_queues queues;
::memset(&queues, 0, sizeof(struct viface_queues));
/*
* checks if the path name can be accessed. if so,
* it means that the network interface is already defined
*/
if (access(("/sys/class/net/" + name).c_str(), F_OK) == 0) {
hookVirtualInterface(name, &queues);
m_name = name;
// read MTU value and resize buffer
m_mtu = readMTU(name, sizeof(m_mtu));
} else {
m_name = allocateVirtualInterface(name, tap, &queues);
m_mtu = DEFAULT_MTU_SIZE;
}
m_queues = queues;
// epoll create
m_epollFd = epoll_create1(0);
if (m_epollFd == -1) {
LogError(LOG_NET, "Unable to initialize epoll %s, err: %d, error: %s", name.c_str(), errno, strerror(errno));
throw std::runtime_error("Unable to initialize epoll.");
}
struct epoll_event ev = {
.events = EPOLLIN,
.data = { .fd = m_queues.rxFd },
};
if (epoll_ctl(m_epollFd, EPOLL_CTL_ADD, ev.data.fd, &ev) == -1) {
LogError(LOG_NET, "Unable to configure epoll %s, err: %d, error: %s", name.c_str(), errno, strerror(errno));
throw std::runtime_error("Unable to configure epoll.");
}
ev.data.fd = m_queues.txFd;
if (epoll_ctl(m_epollFd, EPOLL_CTL_ADD, ev.data.fd, &ev) == -1) {
LogError(LOG_NET, "Unable to configure epoll %s, err: %d, error: %s", name.c_str(), errno, strerror(errno));
throw std::runtime_error("Unable to configure epoll.");
}
// create socket channels to the NET kernel for later ioctl
m_ksFd = -1;
m_ksFd = socket(AF_INET, SOCK_STREAM, 0);
if (m_ksFd < 0) {
LogError(LOG_NET, "Unable to create IPv4 socket channel to the NET kernel %s, err: %d, error: %s", name.c_str(), errno, strerror(errno));
throw std::runtime_error("Unable to create IPv4 socket channel to the NET kernel.");
}
// Set id
if (id < 0) {
m_id = m_idSeq;
m_idSeq++;
} else {
m_id = id;
}
}
/* Finalizes a instance of the VIFace class. */
VIFace::~VIFace()
{
close(m_queues.rxFd);
close(m_queues.txFd);
close(m_ksFd);
}
/* Bring up the virtual interface. */
void VIFace::up()
{
if (isUp()) {
LogError(LOG_NET, "Virtual interface %s is already up.", m_name.c_str());
return;
}
// read interface flags
struct ifreq ifr;
readVIFlags(m_ksFd, m_name, ifr);
// set MAC address
if (!m_mac.empty()) {
uint8_t mac[6U];
::memset(mac, 0x00U, 6U);
parseMAC(mac, m_mac);
ifr.ifr_hwaddr.sa_family = ARPHRD_ETHER;
for (int i = 0; i < 6; i++) {
ifr.ifr_hwaddr.sa_data[i] = mac[i];
}
if (ioctl(m_ksFd, SIOCSIFHWADDR, &ifr) != 0) {
LogError(LOG_NET, "Unable to set MAC address %s, err: %d, error: %s", m_name.c_str(), errno, strerror(errno));
return;
}
}
// set IPv4 related
struct sockaddr_in* addr = (struct sockaddr_in*) &ifr.ifr_addr;
addr->sin_family = AF_INET;
// address
if (!m_ipv4Address.empty()) {
if (!inet_pton(AF_INET, m_ipv4Address.c_str(), &addr->sin_addr)) {
LogError(LOG_NET, "Invalid cached IPv4 address %s, err: %d, error: %s", m_name.c_str(), errno, strerror(errno));
return;
}
if (ioctl(m_ksFd, SIOCSIFADDR, &ifr) != 0) {
LogError(LOG_NET, "Unable to set IPv4 address %s, err: %d, error: %s", m_name.c_str(), errno, strerror(errno));
return;
}
}
// netmask
if (!m_ipv4Netmask.empty()) {
if (!inet_pton(AF_INET, m_ipv4Netmask.c_str(), &addr->sin_addr)) {
LogError(LOG_NET, "Invalid cached IPv4 netmask %s, err: %d, error: %s", m_name.c_str(), errno, strerror(errno));
return;
}
if (ioctl(m_ksFd, SIOCSIFNETMASK, &ifr) != 0) {
LogError(LOG_NET, "Unable to set IPv4 netmask %s, err: %d, error: %s", m_name.c_str(), errno, strerror(errno));
return;
}
}
// broadcast
if (!m_ipv4Broadcast.empty()) {
if (!inet_pton(AF_INET, m_ipv4Broadcast.c_str(), &addr->sin_addr)) {
LogError(LOG_NET, "Invalid cached IPv4 broadcast %s, err: %d, error: %s", m_name.c_str(), errno, strerror(errno));
return;
}
if (ioctl(m_ksFd, SIOCSIFBRDADDR, &ifr) != 0) {
LogError(LOG_NET, "Unable to set IPv4 broadcast %s, err: %d, error: %s", m_name.c_str(), errno, strerror(errno));
return;
}
}
// MTU
ifr.ifr_mtu = m_mtu;
if (ioctl(m_ksFd, SIOCSIFMTU, &ifr) != 0) {
LogError(LOG_NET, "Unable to set MTU %s, err: %d, error: %s", m_name.c_str(), errno, strerror(errno));
return;
}
// bring-up interface
ifr.ifr_flags |= IFF_UP;
if (ioctl(m_ksFd, SIOCSIFFLAGS, &ifr) != 0) {
LogError(LOG_NET, "Unable to bring-up virtual interface %s, err: %d, error: %s", m_name.c_str(), errno, strerror(errno));
}
}
/* Bring down the virtual interface. */
void VIFace::down() const
{
// read interface flags
struct ifreq ifr;
readVIFlags(m_ksFd, m_name, ifr);
// bring-down interface
ifr.ifr_flags &= ~IFF_UP;
if (ioctl(m_ksFd, SIOCSIFFLAGS, &ifr) != 0) {
LogError(LOG_NET, "Unable to bring-down virtual interface %s, err: %d, error: %s", m_name.c_str(), errno, strerror(errno));
}
}
/* Flag indicating wether or not the virtual interface is up. */
bool VIFace::isUp() const
{
// read interface flags
struct ifreq ifr;
readVIFlags(m_ksFd, m_name, ifr);
return (ifr.ifr_flags & IFF_UP) != 0;
}
/* Read a packet from the virtual interface. */
ssize_t VIFace::read(uint8_t* buffer)
{
assert(buffer != nullptr);
::memset(buffer, 0x00U, m_mtu);
struct epoll_event wait_event;
int ret = epoll_wait(m_epollFd, &wait_event, 1, 0);
if ((ret < 0) && (errno != EINTR)) {
LogError(LOG_NET, "Error returned from epoll_wait, err: %d, error: %s", errno, strerror(errno));
return -1;
}
if (ret == 0) {
return -1;
}
// read packet into our buffer
if (ret > 0) {
// Read packet into our buffer
ssize_t len = ::read(wait_event.data.fd, buffer, m_mtu);
if (len == -1) {
LogError(LOG_NET, "Error returned from read, err: %d, error: %s", errno, strerror(errno));
}
return len;
}
return -1;
}
/* Write a packet to this virtual interface. */
bool VIFace::write(const uint8_t* buffer, uint32_t length, ssize_t* lenWritten)
{
assert(buffer != nullptr);
if (length < ETH_HLEN) {
if (lenWritten != nullptr) {
*lenWritten = -1;
}
LogError(LOG_NET, "Packet is too small, err: %d, error: %s", errno, strerror(errno));
return false;
}
if (length > m_mtu) {
if (lenWritten != nullptr) {
*lenWritten = -1;
}
LogError(LOG_NET, "Packet is too large, err: %d, error: %s", errno, strerror(errno));
return false;
}
// write packet to TX queue
bool result = false;
ssize_t sent = ::write(m_queues.txFd, buffer, length);
if (sent < 0) {
LogError(LOG_NET, "Error returned from write, err: %d, error: %s", errno, strerror(errno));
if (lenWritten != nullptr) {
*lenWritten = -1;
}
}
else {
if (sent == ssize_t(length))
result = true;
if (lenWritten != nullptr) {
*lenWritten = sent;
}
}
return result;
}
/* Set the MAC address of the virtual interface. */
void VIFace::setMAC(std::string mac)
{
m_mac = mac;
}
/* Gets the virtual interfaces associated MAC address. */
std::string VIFace::getMAC() const
{
// read interface flags
struct ifreq ifr;
readVIFlags(m_ksFd, m_name, ifr);
if (ioctl(m_ksFd, SIOCGIFHWADDR, &ifr) != 0) {
LogError(LOG_NET, "Unable to get MAC address for virtual interface %s, err: %d, error: %s", m_name.c_str(), errno, strerror(errno));
return std::string();
}
// convert binary MAC address to string
std::ostringstream addr;
addr << std::hex << std::setfill('0');
for (int i = 0; i < 6; i++) {
addr << std::setw(2) << (uint8_t)(0xFF & ifr.ifr_hwaddr.sa_data[i]);
if (i != 5) {
addr << ":";
}
}
return addr.str();
}
/* Set the IPv4 address of the virtual interface. */
void VIFace::setIPv4(std::string address)
{
struct in_addr addr;
if (!inet_pton(AF_INET, address.c_str(), &addr)) {
LogError(LOG_NET, "Invalid IPv4 address %s, err: %d, error: %s", m_name.c_str(), errno, strerror(errno));
return;
}
m_ipv4Address = address;
}
/* Gets the IPV4 address of the virtual interface. */
std::string VIFace::getIPv4() const
{
return ioctlGetIPv4(SIOCGIFADDR);
}
/* Set the IPv4 netmask of the virtual interface. */
void VIFace::setIPv4Netmask(std::string netmask)
{
struct in_addr addr;
if (!inet_pton(AF_INET, netmask.c_str(), &addr)) {
LogError(LOG_NET, "Invalid IPv4 address %s, err: %d, error: %s", m_name.c_str(), errno, strerror(errno));
return;
}
m_ipv4Netmask = netmask;
}
/* Gets the IPv4 netmask of the virtual interface. */
std::string VIFace::getIPv4Netmask() const
{
return ioctlGetIPv4(SIOCGIFNETMASK);
}
/* Set the IPv4 broadcast address of the virtual interface. */
void VIFace::setIPv4Broadcast(std::string broadcast)
{
struct in_addr addr;
if (!inet_pton(AF_INET, broadcast.c_str(), &addr)) {
LogError(LOG_NET, "Invalid IPv4 address %s, err: %d, error: %s", m_name.c_str(), errno, strerror(errno));
return;
}
m_ipv4Broadcast = broadcast;
}
/* Gets the IPv4 broadcast address of the virtual interface. */
std::string VIFace::getIPv4Broadcast() const
{
return ioctlGetIPv4(SIOCGIFBRDADDR);
}
/* Sets the MTU of the virtual interface. */
void VIFace::setMTU(uint32_t mtu)
{
if (mtu < ETH_HLEN) {
LogError(LOG_NET, "MTU %d is too small %s, err: %d, error: %s", mtu, m_name.c_str(), errno, strerror(errno));
return;
}
// are we sure about this upper validation?
// lo interface reports this number for its MTU
if (mtu > 65536) {
LogError(LOG_NET, "MTU %d is too large %s, err: %d, error: %s", mtu, m_name.c_str(), errno, strerror(errno));
return;
}
m_mtu = mtu;
}
/* Gets the MTU of the virtual interface. */
uint32_t VIFace::getMTU() const
{
// read interface flags
struct ifreq ifr;
readVIFlags(m_ksFd, m_name, ifr);
if (ioctl(m_ksFd, SIOCGIFMTU, &ifr) != 0) {
LogError(LOG_NET, "Unable to get MTU address for virtual interface %s, err: %d, error: %s", m_name.c_str(), errno, strerror(errno));
return 0U;
}
return ifr.ifr_mtu;
}
// ---------------------------------------------------------------------------
// Private Class Members
// ---------------------------------------------------------------------------
/* Internal helper that performs a kernel IOCTL to get the IPv4 address by request. */
std::string VIFace::ioctlGetIPv4(uint64_t request) const
{
// read interface flags
struct ifreq ifr;
readVIFlags(m_ksFd, m_name, ifr);
if (ioctl(m_ksFd, request, &ifr) != 0) {
LogError(LOG_NET, "Unable to get IPv4 address for virtual interface %s, err: %d, error: %s", m_name.c_str(), errno, strerror(errno));
return std::string();
}
// convert binary IP address to string
char addr[INET_ADDRSTRLEN];
::memset(&addr, 0, sizeof(addr));
struct sockaddr_in* ipaddr = (struct sockaddr_in*) &ifr.ifr_addr;
if (inet_ntop(AF_INET, &(ipaddr->sin_addr), addr, sizeof(addr)) == NULL) {
LogError(LOG_NET, "Unable to convert IPv4 address for virtual interface %s, err: %d, error: %s", m_name.c_str(), errno, strerror(errno));
return std::string();
}
return std::string(addr);
}

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