Consolidate raw socket acquisition.

FPEngine.cc

@@ -118,7 +118,7 @@ FPNetworkControl::~FPNetworkControl() {
 
 /* (Re)-Initialize object's state (default parameter setup and nsock
  * initialization). */
-void FPNetworkControl::init(const char *ifname, devtype iftype) {
+void FPNetworkControl::init(const char *ifname) {
 
   /* Init congestion control parameters */
   this->cc_init();
@@ -155,27 +155,14 @@ void FPNetworkControl::init(const char *ifname, devtype iftype) {
   /* Flag it as already initialized so we free this nsp next time */
   this->nsock_init = true;
 
+  /* We don't need to store the eth handle because FPProbes come with a
+   * suitable one (FPProbes::getEthernet()), we just attempt to obtain one
+   * to see if it fails. */
+  netutil_eth_t *ethsd = NULL;
+
   /* Obtain raw socket or check that we can obtain an eth descriptor. */
-  if ((o.sendpref & PACKET_SEND_ETH) && (iftype == devt_ethernet
-#ifdef WIN32
-        || (o.have_pcap && iftype == devt_loopback)
-#endif
-        ) && ifname != NULL) {
-    /* We don't need to store the eth handler because FPProbes come with a
-     * suitable one (FPProbes::getEthernet()), we just attempt to obtain one
-     * to see if it fails. */
-    if (eth_open_cached(ifname) == NULL)
-      fatal("dnet: failed to open device %s", ifname);
-    this->rawsd = -1;
-  } else {
-#ifdef WIN32
-    win32_fatal_raw_sockets(ifname);
-#endif
-    if (this->rawsd >= 0)
-      close(this->rawsd);
-    rawsd = nmap_raw_socket();
-    if (rawsd < 0)
-      pfatal("Couldn't obtain raw socket in %s", __func__);
+  if (!raw_socket_or_eth(o.sendpref, ifname, &this->rawsd, &ethsd)) {
+    fatal("Couldn't obtain raw socket or eth handle in %s", __func__);
   }
 
   /* De-register existing callers */
@@ -1135,7 +1122,7 @@ int FPEngine6::os_scan(std::vector<Target *> &Targets) {
 
   /* Initialize variables, timers, etc. */
   gettimeofday(&begin_time, NULL);
-  global_netctl.init(Targets[0]->deviceName(), Targets[0]->ifType());
+  global_netctl.init(Targets[0]->deviceName());
   for (size_t i = 0; i < Targets.size(); i++) {
     if (o.debugging > 3) {
       log_write(LOG_PLAIN, "[FPEngine] Allocating FPHost6 for %s %s\n",

FPEngine.h

@@ -157,7 +157,7 @@ class FPNetworkControl {
  public:
   FPNetworkControl();
   ~FPNetworkControl();
-  void init(const char *ifname, devtype iftype);
+  void init(const char *ifname);
   int register_caller(FPHost *newcaller);
   int unregister_caller(FPHost *oldcaller);
   int setup_sniffer(const char *iface, const char *bfp_filter);

NmapOps.cc

@@ -68,6 +68,7 @@
 #include "NmapOps.h"
 #include "osscan.h"
 #include "nmap_error.h"
+#include "libnetutil/netutil.h"
 
 NmapOps o;
 

NmapOps.h

@@ -123,24 +123,6 @@ class NmapOps {
   u8 debugging;
   bool resuming;
 
-#define PACKET_SEND_NOPREF 1
-#define PACKET_SEND_ETH_WEAK 2
-#define PACKET_SEND_ETH_STRONG 4
-#define PACKET_SEND_ETH 6
-#define PACKET_SEND_IP_WEAK 8
-#define PACKET_SEND_IP_STRONG 16
-#define PACKET_SEND_IP 24
-
-  /* How should we send raw IP packets?  Nmap can generally use either
-     ethernet or raw ip sockets.  Which is better depends on platform
-     and goals.  A _STRONG preference means that Nmap should use the
-     preferred method whenever it is possible (obviously it isn't
-     always possible -- sending ethernet frames won't work over a PPP
-     connection).  This is useful when the other type doesn't work at
-     all.  A _WEAK preference means that Nmap may use the other type
-     where it is substantially more efficient to do so. For example,
-     Nmap will still do an ARP ping scan of a local network even when
-     the pref is SEND_IP_WEAK */
   int sendpref;
   bool packetTrace() { return (debugging >= 3)? true : pTrace;  }
   bool versionTrace() { return packetTrace()? true : vTrace;  }

idle_scan.cc

@@ -599,30 +599,19 @@ static void initialize_idleproxy(struct idle_proxy_info *proxy, char *proxyName,
 
   /* Now lets send some probes to check IP ID algorithm ... */
   /* First we need a raw socket ... */
-  if ((o.sendpref & PACKET_SEND_ETH) && (proxy->host.ifType() == devt_ethernet
-#ifdef WIN32
-    || (o.have_pcap && proxy->host.ifType() == devt_loopback)
-#endif
-    )) {
+  if (!raw_socket_or_eth(o.sendpref, proxy->host.deviceName(),
+        &proxy->rawsd, &proxy->eth.ethsd)) {
+    fatal("%s: Failed to open raw socket or ethernet handle", __func__);
+  }
+  if (proxy->eth.ethsd != NULL) {
     if (!setTargetNextHopMAC(&proxy->host))
       fatal("%s: Failed to determine dst MAC address for Idle proxy", __func__);
     memcpy(proxy->eth.srcmac, proxy->host.SrcMACAddress(), 6);
     memcpy(proxy->eth.dstmac, proxy->host.NextHopMACAddress(), 6);
-    proxy->eth.ethsd = eth_open_cached(proxy->host.deviceName());
-    if (proxy->eth.ethsd == NULL)
-      fatal("%s: Failed to open ethernet device (%s)", __func__, proxy->host.deviceName());
-    proxy->rawsd = -1;
     proxy->ethptr = &proxy->eth;
-  } else {
-#ifdef WIN32
-    win32_fatal_raw_sockets(proxy->host.deviceName());
-#endif
-    proxy->rawsd = nmap_raw_socket();
-    if (proxy->rawsd < 0)
-      pfatal("socket troubles in %s", __func__);
+  }
+  else {
     unblock_socket(proxy->rawsd);
-    proxy->eth.ethsd = NULL;
-    proxy->ethptr = NULL;
   }
 
   if (proxy->host.af() == AF_INET6)

libnetutil/netutil.cc

@@ -1088,6 +1088,98 @@ void eth_close_cached() {
   return;
 }
 
+static void netutil_perror(const char *msg) {
+  int err = socket_errno();
+  netutil_error("%s: (%d) %s", msg, err, socket_strerror(err));
+}
+
+/* Create a raw socket and do things that always apply to raw sockets:
+    * Set SO_BROADCAST.
+    * Set IP_HDRINCL.
+    * Bind to an interface with SO_BINDTODEVICE (if device is not NULL).
+   The socket is created with address family AF_INET, but may be usable for
+   AF_INET6, depending on the operating system. */
+int netutil_raw_socket(const char *device) {
+#ifdef WIN32
+  netutil_error("Windows does not have adequate raw socket support.");
+  return -1;
+#else
+  int rawsd;
+  int one = 1;
+
+  rawsd = socket(AF_INET, SOCK_RAW, IPPROTO_RAW);
+  if (rawsd < 0) {
+    netutil_perror("Couldn't open a raw socket. "
+#if defined(sun) && defined(__SVR4)
+        "In Solaris shared-IP non-global zones, this requires the PRIV_NET_RAWACCESS privilege. "
+#endif
+        "Error");
+    return -1;
+  }
+  if (setsockopt (rawsd, SOL_SOCKET, SO_BROADCAST, (const char *) &one, sizeof(int)) != 0) {
+    netutil_perror("setsockopt(SO_BROADCAST) failed");
+  }
+  sethdrinclude(rawsd);
+  socket_bindtodevice(rawsd, device);
+
+  return rawsd;
+#endif
+}
+
+int raw_socket_or_eth(int sendpref, const char *ifname,
+    int *rawsd, netutil_eth_t **ethsd) {
+  assert(rawsd != NULL);
+  *rawsd = -1;
+  assert(ethsd != NULL);
+  *ethsd = NULL;
+  bool may_try_eth = ifname && !(sendpref & PACKET_SEND_IP_STRONG);
+  bool may_try_ip = !(sendpref & PACKET_SEND_ETH_STRONG);
+  bool try_eth = may_try_eth && (sendpref & PACKET_SEND_ETH);
+  bool try_ip = may_try_ip && (sendpref & PACKET_SEND_IP);
+
+  for (int i = 0; i < 2; i++) {
+    if (try_eth) {
+      try_eth = false;
+      may_try_eth = false;
+      try_ip = may_try_ip;
+
+      netutil_eth_t *e = eth_open_cached(ifname);
+      *ethsd = e;
+      if (e == NULL) {
+        netutil_error("dnet: failed to open device %s", ifname);
+      }
+      else if (!netutil_eth_can_send(e)) {
+        netutil_error("%s is not a supported device for sending.", ifname);
+        e = NULL;
+      }
+      else {
+        break;
+      }
+    }
+
+    if (try_ip) {
+      try_ip = false;
+      may_try_ip = false;
+      try_eth = may_try_eth;
+
+#ifdef WIN32
+      /* For Windows, don't even bother trying unless the caller insists, to
+       * avoid excessive error messages. */
+      if (!(sendpref & PACKET_SEND_IP_STRONG)) {
+        continue;
+      }
+#endif
+      int sd = netutil_raw_socket(ifname);
+      *rawsd = sd;
+      if (sd >= 0) {
+        break;
+      }
+    }
+  }
+
+  return (*ethsd != NULL || *rawsd >= 0) ? 1 : 0;
+}
+
 /* Takes a protocol number like IPPROTO_TCP, IPPROTO_UDP, IPPROTO_IP,
  * etc, and returns an ASCII representation (or the string "unknown" if
  * it doesn't recognize the number). If uppercase is non zero, the

libnetutil/netutil.h

@@ -305,6 +305,34 @@ int netutil_eth_can_send(const netutil_eth_t *e);
 /* See the description for eth_open_cached */
 void eth_close_cached();
 
+/* Create a raw socket and do things that always apply to raw sockets:
+    * Set SO_BROADCAST.
+    * Set IP_HDRINCL.
+    * Bind to an interface with SO_BINDTODEVICE (if device is not NULL).
+   The socket is created with address family AF_INET, but may be usable for
+   AF_INET6, depending on the operating system. */
+int netutil_raw_socket(const char *device);
+
+/* How should we send raw IP packets?  Nmap can generally use either
+   ethernet or raw ip sockets.  Which is better depends on platform
+   and goals.  A _STRONG preference means that Nmap should use the
+   preferred method whenever it is possible (obviously it isn't
+   always possible -- sending ethernet frames won't work over a PPP
+   connection).  This is useful when the other type doesn't work at
+   all.  A _WEAK preference means that Nmap may use the other type
+   where it is substantially more efficient to do so. For example,
+   Nmap will still do an ARP ping scan of a local network even when
+   the pref is SEND_IP_WEAK */
+#define PACKET_SEND_NOPREF      0x01
+#define PACKET_SEND_ETH_WEAK    0x02
+#define PACKET_SEND_ETH_STRONG  0x04
+#define PACKET_SEND_ETH (PACKET_SEND_ETH_WEAK | PACKET_SEND_ETH_STRONG)
+#define PACKET_SEND_IP_WEAK     0x08
+#define PACKET_SEND_IP_STRONG   0x10
+#define PACKET_SEND_IP (PACKET_SEND_IP_WEAK | PACKET_SEND_IP_STRONG)
+int raw_socket_or_eth(int sendpref, const char *ifname,
+    int *rawsd, netutil_eth_t **ethsd);
+
 /* Takes a protocol number like IPPROTO_TCP, IPPROTO_UDP, or
  * IPPROTO_IP and returns a ascii representation (or "unknown" if it
  * doesn't recognize the number).  Returned string is in lowercase. */

nping/NpingOps.cc

@@ -105,7 +105,6 @@ NpingOps::NpingOps() {
     sendpref_set=false;
 
     send_eth=false;
-    send_eth_set=false;
 
     delay=0;
     delay_set=false;
@@ -620,10 +619,10 @@ bool NpingOps::issetPacketCount(){
  *  PACKET_SEND_ETH, PACKET_SEND_IP_WEAK, PACKET_SEND_IP_STRONG, PACKET_SEND_IP
  *  @return OP_SUCCESS on success and OP_FAILURE in case of error.           */
 int NpingOps::setSendPreference(int v){
-   if( v!=PACKET_SEND_NOPREF && v!=PACKET_SEND_ETH_WEAK &&
-       v!=PACKET_SEND_ETH_STRONG && v!=PACKET_SEND_ETH &&
-       v!=PACKET_SEND_IP_WEAK && v!=PACKET_SEND_IP_STRONG &&
-       v!=PACKET_SEND_IP ){
+  // Validate: no extra bits set
+  if( (v & ~(PACKET_SEND_ETH | PACKET_SEND_IP))
+      // Validate: both ETH and IP cannot be STRONG
+      || ((v & PACKET_SEND_ETH_STRONG) && (v & PACKET_SEND_IP_STRONG))) {
         nping_fatal(QT_3,"setSendPreference(): Invalid value supplied\n");
         return OP_FAILURE;
     }else{
@@ -648,51 +647,31 @@ bool NpingOps::issetSendPreference(){
 
 /* Returns true if send preference is Ethernet */
 bool NpingOps::sendPreferenceEthernet(){
-  if ( this->getSendPreference()==PACKET_SEND_ETH_WEAK )
-    return true;
-  else if (this->getSendPreference()==PACKET_SEND_ETH_STRONG)
-    return true;
-  else if (this->getSendPreference()==PACKET_SEND_ETH )
-    return true;
-  else
-    return false;
+  return (this->sendpref & PACKET_SEND_ETH);
 } /* End of sendPreferenceEthernet() */
 
 
 /* Returns true if send preference is Ethernet */
 bool NpingOps::sendPreferenceIP(){
-  if ( this->getSendPreference()==PACKET_SEND_IP_WEAK )
-    return true;
-  else if (this->getSendPreference()==PACKET_SEND_IP_STRONG)
-    return true;
-  else if (this->getSendPreference()==PACKET_SEND_IP )
-    return true;
-  else
-    return false;
+  return (this->sendpref & PACKET_SEND_IP);
 } /* End of sendPreferenceIP() */
 
 
 /** Sets SendEth.
  *  @return OP_SUCCESS on success and OP_FAILURE in case of error.           */
 int NpingOps::setSendEth(bool val){
-  this->send_eth=val;
-  this->send_eth_set=true;
+  this->sendpref = PACKET_SEND_ETH;
+  this->sendpref_set = true;
   return OP_SUCCESS;
 } /* End of setSendEth() */
 
 
 /** Returns value of attribute send_eth */
 bool NpingOps::sendEth(){
-  return this->send_eth;
+  return (this->sendpref & PACKET_SEND_ETH_STRONG);
 } /* End of getSendEth() */
 
 
-/* Returns true if option has been set */
-bool NpingOps::issetSendEth(){
-  return this->send_eth_set;
-} /* End of issetSendEth() */
-
-
 /** Sets inter-probe delay. Supplied parameter is assumed to be in milliseconds
  *  and must be a long integer greater than zero.
  *  @warning timeout is assumed to be in milliseconds. Use tval2msecs() from

nping/NpingOps.h

@@ -97,14 +97,6 @@
 #define FLAG_SYN  6
 #define FLAG_FIN  7
 
-#define PACKET_SEND_NOPREF 1 /* These have been taken from NmapOps.h */
-#define PACKET_SEND_ETH_WEAK 2
-#define PACKET_SEND_ETH_STRONG 4
-#define PACKET_SEND_ETH 6
-#define PACKET_SEND_IP_WEAK 8
-#define PACKET_SEND_IP_STRONG 16
-#define PACKET_SEND_IP 24
-
 #define IP_VERSION_4 0x04
 #define IP_VERSION_6 0x06
 

nse_dnet.cc

@@ -223,7 +223,7 @@ static int ethernet_send (lua_State *L)
 static int ip_open (lua_State *L)
 {
   nse_dnet_udata *udata = (nse_dnet_udata *) nseU_checkudata(L, 1, DNET_METATABLE, "dnet");
-  udata->sock = nmap_raw_socket();
+  udata->sock = netutil_raw_socket(NULL);
   if (udata->sock == -1) {
     if (o.scriptTrace())
     {

osscan2.cc

@@ -1336,24 +1336,11 @@ HostOsScan::HostOsScan(Target *t) {
   rawsd = -1;
   ethsd = NULL;
 
-  if ((o.sendpref & PACKET_SEND_ETH) && (t->ifType() == devt_ethernet
-#ifdef WIN32
-    || (o.have_pcap && t->ifType() == devt_loopback)
-#endif
-    )) {
-    if ((ethsd = eth_open_cached(t->deviceName())) == NULL)
-      fatal("%s: Failed to open ethernet device (%s)", __func__, t->deviceName());
-    rawsd = -1;
-  } else {
-#ifdef WIN32
-    win32_fatal_raw_sockets(t->deviceName());
-#endif
-    rawsd = nmap_raw_socket();
-    if (rawsd < 0)
-      pfatal("socket troubles in %s", __func__);
-    unblock_socket(rawsd);
-    ethsd = NULL;
+  if (!raw_socket_or_eth(o.sendpref, t->deviceName(), &rawsd, &ethsd)) {
+    fatal("%s: Failed to open raw socket or ethernet device", __func__);
   }
+  if (rawsd >= 0)
+    unblock_socket(rawsd);
 
   if (o.magic_port_set) {
     tcpPortBase = o.magic_port;

output.cc

@@ -218,22 +218,6 @@ static void print_xml_service(const struct serviceDeductions *sd) {
 }
 
 #ifdef WIN32
-/* Show a fatal error explaining that an interface is not Ethernet and won't
-   work on Windows. Do nothing if --send-ip (PACKET_SEND_IP_STRONG) was used. */
-void win32_fatal_raw_sockets(const char *devname) {
-  if ((o.sendpref & PACKET_SEND_IP_STRONG) != 0)
-    return;
-
-  if (devname != NULL) {
-    fatal("Only ethernet devices can be used for raw scans on Windows, and\n"
-          "\"%s\" is not an ethernet device. Use the --unprivileged option\n"
-          "for this scan.", devname);
-  } else {
-    fatal("Only ethernet devices can be used for raw scans on Windows. Use\n"
-          "the --unprivileged option for this scan.");
-  }
-}
-
 /* Display the mapping from libdnet interface names (like "eth0") to Npcap
    interface names (like "\Device\NPF_{...}"). This is the same mapping used by
    eth_open and so can help diagnose connection problems.  Additionally display

output.h

@@ -123,12 +123,6 @@ class Target;
 # endif
 #endif
 
-#ifdef WIN32
-/* Show a fatal error explaining that an interface is not Ethernet and won't
-   work on Windows. Do nothing if --send-ip (PACKET_SEND_IP_STRONG) was used. */
-void win32_fatal_raw_sockets(const char *devname);
-#endif
-
 /* Prints the familiar Nmap tabular output showing the "interesting"
    ports found on the machine.  It also handles the Machine/Grepable
    output and the XML output.  It is pretty ugly -- in particular I

scan_engine.cc

@@ -949,39 +949,15 @@ void UltraScanInfo::Init(std::vector<Target *> &Targets, const struct scan_lists
      aren't doing a TCP connect scan, or if we're doing a ping scan that
      requires it. */
   if (isRawScan()) {
-    const char *device = Targets[0]->deviceName();
-    if (ping_scan_arp || (ping_scan_nd && o.sendpref != PACKET_SEND_IP_STRONG) || (o.sendpref & PACKET_SEND_ETH)) {
-      /* We'll send ethernet packets with dnet */
-      ethsd = eth_open_cached(device);
-      if (ethsd == NULL) {
-        error("dnet: Failed to open device %s", device);
-      }
-      else if (!netutil_eth_can_send(ethsd)) {
-        ethsd = NULL;
-      }
-      /* If eth failed, we can fall back to raw socket. The only exception is
-       * ARP ping, which needs Ethernet link. */
-      if (ping_scan_arp && (ethsd == NULL || netutil_eth_datalink(ethsd) != DLT_EN10MB)) {
-        fatal("ARP ping not supported on %s", device);
-      }
+    /* If eth failed, we can fall back to raw socket. The only exception is
+     * ARP ping, which needs Ethernet link. */
+    int sendpref = o.sendpref;
+    if (ping_scan_arp) {
+      assert(!(sendpref & PACKET_SEND_IP_STRONG));
+      sendpref = PACKET_SEND_ETH;
     }
-    if (ethsd == NULL) {
-#ifdef WIN32
-      win32_fatal_raw_sockets(Targets[0]->deviceName());
-#endif
-      rawsd = nmap_raw_socket();
-      if (rawsd < 0)
-        pfatal("Couldn't open a raw socket. "
-#if defined(sun) && defined(__SVR4)
-        "In Solaris shared-IP non-global zones, this requires the PRIV_NET_RAWACCESS privilege. "
-#endif
-        "Error"
-        );
-      /* We do not want to unblock the socket since we want to wait
-      if kernel send buffers fill up rather than get ENOBUF, and
-      we won't be receiving on the socket anyway
-      unblock_socket(rawsd);*/
-      ethsd = NULL;
+    if (!raw_socket_or_eth(sendpref, Targets[0]->deviceName(), &rawsd, &ethsd)) {
+      fatal("Couldn't open a raw socket or eth handle.");
     }
     /* Raw scan types also need to know the source IP. */
     Targets[0]->SourceSockAddr(&sourceSockAddr, NULL);

tcpip.cc

@@ -87,31 +87,6 @@ extern NmapOps o;
 
 static PacketCounter PktCt;
 
-/* Create a raw socket and do things that always apply to raw sockets:
-    * Set SO_BROADCAST.
-    * Set IP_HDRINCL.
-    * Bind to an interface with SO_BINDTODEVICE (if o.device is set).
-   The socket is created with address family AF_INET, but may be usable for
-   AF_INET6, depending on the operating system. */
-int nmap_raw_socket() {
-  int rawsd;
-  int one = 1;
-
-  rawsd = socket(AF_INET, SOCK_RAW, IPPROTO_RAW);
-  if (rawsd < 0)
-    return rawsd;
-  if (setsockopt (rawsd, SOL_SOCKET, SO_BROADCAST, (const char *) &one, sizeof(int)) != 0) {
-    error("Failed to secure socket broadcasting permission");
-    perror("setsockopt");
-  }
-#ifndef WIN32
-  sethdrinclude(rawsd);
-#endif
-  socket_bindtodevice(rawsd, o.device);
-
-  return rawsd;
-}
-
 /* Fill buf (up to buflen -- truncate if necessary but always
    terminate) with a short representation of the packet stats.
    Returns buf.  Aborts if there is a problem. */

traceroute.cc

@@ -837,19 +837,8 @@ TracerouteState::TracerouteState(std::vector<Target *> &targets) {
 
   assert(targets.size() > 0);
 
-  if ((o.sendpref & PACKET_SEND_ETH) && targets[0]->ifType() == devt_ethernet) {
-    ethsd = eth_open_cached(targets[0]->deviceName());
-    if (ethsd == NULL)
-      fatal("dnet: failed to open device %s", targets[0]->deviceName());
-    rawsd = -1;
-  } else {
-#ifdef WIN32
-    win32_fatal_raw_sockets(targets[0]->deviceName());
-#endif
-    rawsd = nmap_raw_socket();
-    if (rawsd < 0)
-      pfatal("traceroute: socket troubles");
-    ethsd = NULL;
+  if (!raw_socket_or_eth(o.sendpref, targets[0]->deviceName(), &rawsd, &ethsd)) {
+    fatal("traceroute: socket troubles");
   }
 
   /* Assume that all the targets share the same device. */