Added broadcast option!

Author: jacopodl

include/Options.h

@@ -17,6 +17,7 @@ struct Options {
  bool enableServer = false;
 
  // DhcpServerOptions
+ unsigned short serverFlags = 0;
  unsigned short lease = 0;
  netaddr_ip gateway{};
  netaddr_ip primaryDns{};

src/Core.cpp

@@ -73,7 +73,7 @@ void Core::dhcpServer(DhcpPacket *message) {
  0,
  message->xid,
  0,
- DHCP_FLAGS_BROADCAST,
+ this->options.serverFlags,
  nullptr,
  &slot->clientIp,
  &this->socket.netinfo.ipAddr,
@@ -82,11 +82,19 @@ void Core::dhcpServer(DhcpPacket *message) {
  nullptr);
  memcpy(response.chaddr, message->chaddr, ETHHWASIZE);
  this->addDhcpDefaultOpt(&response, slot, DHCP_OFFER);
+
  // INFO
  pktInfo.ipSrc = this->socket.netinfo.ipAddr;
- pktInfo.ipDst.ip = 0xFFFFFFFF;
- eth_bcast(&pktInfo.phisAddr);
  pktInfo.toServer = false;
+
+ if (this->options.serverFlags & DHCP_FLAGS_BROADCAST) {
+ pktInfo.ipDst.ip = 0xFFFFFFFF;
+ eth_bcast(&pktInfo.phisAddr);
+ } else {
+ pktInfo.ipDst.ip = slot->clientIp.ip;
+ memcpy(pktInfo.phisAddr.mac, message->chaddr, ETHHWASIZE);
+ }
+
  if ((tmp = this->socket.sendDhcpMsg(&response, DHCPPKTSIZE, &pktInfo)) < 0)
  std::cerr << "DHCP server err: " << spark_strerror(tmp) << std::endl;
  } else if (dhcp_type_equals(message, DHCP_REQUEST)) {
@@ -112,7 +120,7 @@ void Core::dhcpServer(DhcpPacket *message) {
  0,
  message->xid,
  0,
- DHCP_FLAGS_BROADCAST,
+ this->options.serverFlags,
  nullptr,
  &slot->clientIp,
  &this->socket.netinfo.ipAddr,
@@ -121,11 +129,17 @@ void Core::dhcpServer(DhcpPacket *message) {
  nullptr);
  memcpy(response.chaddr, message->chaddr, ETHHWASIZE);
  this->addDhcpDefaultOpt(&response, slot, DHCP_ACK);
+
  // INFO
  pktInfo.ipSrc = this->socket.netinfo.ipAddr;
- pktInfo.ipDst.ip = 0xFFFFFFFF;
- eth_bcast(&pktInfo.phisAddr);
  pktInfo.toServer = false;
+ if (this->options.serverFlags & DHCP_FLAGS_BROADCAST) {
+ pktInfo.ipDst.ip = 0xFFFFFFFF;
+ eth_bcast(&pktInfo.phisAddr);
+ } else {
+ pktInfo.ipDst.ip = slot->clientIp.ip;
+ memcpy(pktInfo.phisAddr.mac, message->chaddr, ETHHWASIZE);
+ }
  if ((tmp = this->socket.sendDhcpMsg(&response, DHCPPKTSIZE, &pktInfo)) < 0)
  std::cerr << "DHCP server err: " << spark_strerror(tmp) << std::endl;
  } else if (dhcp_type_equals(message, DHCP_RELEASE))

src/main.cpp

@@ -35,6 +35,7 @@ int main(int argc, char **argv) {
  {(char *) "no-release", ARGSX_NOARG, 4},
  {(char *) "help", ARGSX_NOARG, 'h'},
  {(char *) "version", ARGSX_NOARG, 'v'},
+ {(char *) "bcast", ARGSX_NOARG, 'b'},
  {(char *) "server", ARGSX_NOARG, 's'},
  {(char *) "gateway", ARGSX_REQ_ARG, 'g'},
  {(char *) "lease", ARGSX_NOARG, 'l'},
@@ -46,7 +47,7 @@ int main(int argc, char **argv) {
  return 0;
  }
 
- while ((opt = argsx(argc, argv, (char *) "hvsg!ld!", lopt, sizeof(lopt), '-')) != -1) {
+ while ((opt = argsx(argc, argv, (char *) "hvbsg!ld!", lopt, sizeof(lopt), '-')) != -1) {
  switch (opt) {
  case 1:
  core.options.mode |= ATKMODE_FLOOD;
@@ -70,6 +71,9 @@ int main(int argc, char **argv) {
  __DATE__, __TIME__);
 #endif
  return 0;
+ case 'b':
+ core.options.serverFlags |= DHCP_FLAGS_BROADCAST;
+ break;
  case 's':
  core.options.enableServer = true;
  break;
@@ -139,6 +143,7 @@ void usage() {
  "\nUsage: %s <iface> --<flood|release|starvation>\n"
  "\t-h, --help \tPrint this help and exit.\n"
  "\t-v, --version\tPrint version and exit.\n"
+ "\t-b, --bcast \tUse broadcast reply.\n"
  "\t-s, --server \tEnable dhcp rogue server.\n"
  "\t-l, --lease \tSet lease time.\n"
  "\t-d, --dns \tSet primary DNS address.\n"