a decent amount of OS detection changes/fixes

osscan.cc

@@ -2,7 +2,7 @@
 /***************************************************************************
  * osscan.cc -- Routines used for OS detection via TCP/IP fingerprinting.  *
  * For more information on how this works in Nmap, see my paper at         *
- * http://www.insecure.org/nmap/nmap-fingerprinting-article.html           *
+ * http://www.insecure.org/osdetect/                                       *
  *                                                                         *
  ***********************IMPORTANT NMAP LICENSE TERMS************************
  *                                                                         *

osscan2.cc

@@ -1,4 +1,105 @@
 
+/***************************************************************************
+ * osscan2.cc -- Routines used for 2nd Generation OS detection via         *
+ * TCP/IP fingerprinting.  * For more information on how this works in     *
+ * Nmap, see http://insecure.org/nmap/osdetect/                            *
+ *                                                                         *
+ ***********************IMPORTANT NMAP LICENSE TERMS************************
+ *                                                                         *
+ * The Nmap Security Scanner is (C) 1996-2004 Insecure.Com LLC. Nmap       *
+ * is also a registered trademark of Insecure.Com LLC.  This program is    *
+ * free software; you may redistribute and/or modify it under the          *
+ * terms of the GNU General Public License as published by the Free        *
+ * Software Foundation; Version 2.  This guarantees your right to use,     *
+ * modify, and redistribute this software under certain conditions.  If    *
+ * you wish to embed Nmap technology into proprietary software, we may be  *
+ * willing to sell alternative licenses (contact sales@insecure.com).      *
+ * Many security scanner vendors already license Nmap technology such as  *
+ * our remote OS fingerprinting database and code, service/version         *
+ * detection system, and port scanning code.                               *
+ *                                                                         *
+ * Note that the GPL places important restrictions on "derived works", yet *
+ * it does not provide a detailed definition of that term.  To avoid       *
+ * misunderstandings, we consider an application to constitute a           *
+ * "derivative work" for the purpose of this license if it does any of the *
+ * following:                                                              *
+ * o Integrates source code from Nmap                                      *
+ * o Reads or includes Nmap copyrighted data files, such as                *
+ *   nmap-os-fingerprints or nmap-service-probes.                          *
+ * o Executes Nmap and parses the results (as opposed to typical shell or  *
+ *   execution-menu apps, which simply display raw Nmap output and so are  *
+ *   not derivative works.)                                                * 
+ * o Integrates/includes/aggregates Nmap into a proprietary executable     *
+ *   installer, such as those produced by InstallShield.                   *
+ * o Links to a library or executes a program that does any of the above   *
+ *                                                                         *
+ * The term "Nmap" should be taken to also include any portions or derived *
+ * works of Nmap.  This list is not exclusive, but is just meant to        *
+ * clarify our interpretation of derived works with some common examples.  *
+ * These restrictions only apply when you actually redistribute Nmap.  For *
+ * example, nothing stops you from writing and selling a proprietary       *
+ * front-end to Nmap.  Just distribute it by itself, and point people to   *
+ * http://www.insecure.org/nmap/ to download Nmap.                         *
+ *                                                                         *
+ * We don't consider these to be added restrictions on top of the GPL, but *
+ * just a clarification of how we interpret "derived works" as it applies  *
+ * to our GPL-licensed Nmap product.  This is similar to the way Linus     *
+ * Torvalds has announced his interpretation of how "derived works"        *
+ * applies to Linux kernel modules.  Our interpretation refers only to     *
+ * Nmap - we don't speak for any other GPL products.                       *
+ *                                                                         *
+ * If you have any questions about the GPL licensing restrictions on using *
+ * Nmap in non-GPL works, we would be happy to help.  As mentioned above,  *
+ * we also offer alternative license to integrate Nmap into proprietary    *
+ * applications and appliances.  These contracts have been sold to many    *
+ * security vendors, and generally include a perpetual license as well as  *
+ * providing for priority support and updates as well as helping to fund   *
+ * the continued development of Nmap technology.  Please email             *
+ * sales@insecure.com for further information.                             *
+ *                                                                         *
+ * As a special exception to the GPL terms, Insecure.Com LLC grants        *
+ * permission to link the code of this program with any version of the     *
+ * OpenSSL library which is distributed under a license identical to that  *
+ * listed in the included Copying.OpenSSL file, and distribute linked      *
+ * combinations including the two. You must obey the GNU GPL in all        *
+ * respects for all of the code used other than OpenSSL.  If you modify    *
+ * this file, you may extend this exception to your version of the file,   *
+ * but you are not obligated to do so.                                     *
+ *                                                                         *
+ * If you received these files with a written license agreement or         *
+ * contract stating terms other than the terms above, then that            *
+ * alternative license agreement takes precedence over these comments.     *
+ *                                                                         *
+ * Source is provided to this software because we believe users have a     *
+ * right to know exactly what a program is going to do before they run it. *
+ * This also allows you to audit the software for security holes (none     *
+ * have been found so far).                                                *
+ *                                                                         *
+ * Source code also allows you to port Nmap to new platforms, fix bugs,    *
+ * and add new features.  You are highly encouraged to send your changes   *
+ * to fyodor@insecure.org for possible incorporation into the main         *
+ * distribution.  By sending these changes to Fyodor or one the            *
+ * Insecure.Org development mailing lists, it is assumed that you are      *
+ * offering Fyodor and Insecure.Com LLC the unlimited, non-exclusive right *
+ * to reuse, modify, and relicense the code.  Nmap will always be          *
+ * available Open Source, but this is important because the inability to   *
+ * relicense code has caused devastating problems for other Free Software  *
+ * projects (such as KDE and NASM).  We also occasionally relicense the    *
+ * code to third parties as discussed above.  If you wish to specify       *
+ * special license conditions of your contributions, just say so when you  *
+ * send them.                                                              *
+ *                                                                         *
+ * This program is distributed in the hope that it will be useful, but     *
+ * WITHOUT ANY WARRANTY; without even the implied warranty of              *
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU       *
+ * General Public License for more details at                              *
+ * http://www.gnu.org/copyleft/gpl.html , or in the COPYING file included  *
+ * with Nmap.                                                              *
+ *                                                                         *
+ ***************************************************************************/
+
+/* $Id: osscan.cc 3636 2006-07-04 23:04:56Z fyodor $ */
+
 #include "osscan.h"
 #include "osscan2.h"
 #include "timing.h"
@@ -25,7 +126,7 @@ extern NmapOps o;
 /* 8 options:
  *  0~5: six options for SEQ/OPS/WIN/T1 probes.
  *  6:   ECN probe.
- *  7:   T2~T7 probes.
+ *  7-12:   T2~T7 probes.
  *
  * option 0: WScale (10), Nop, MSS (1460), Timestamp, SackP
  * option 1: MSS (1400), WScale (0), Nop, SackP, T
@@ -34,22 +135,32 @@ extern NmapOps o;
  * option 4: MSS (536), SackP, T, WScale (10), Nop
  * option 5: MSS (265), SackP, Nop, Nop, T, Nop, End
  * option 6: WScale (10), Nop, MSS (1460), SackP, Nop, Nop
- * option 7: WScale (10), Nop, MSS (265), T, SackP
+ * option 7-11: WScale (10), Nop, MSS (265), T, SackP
+ * option 12: WScale (15), Nop, MSS (265), T, SackP
  */
 static struct {
   u8* val;
   int len;
-} prbOpts[NUM_SEQ_SAMPLES + 2] = {
+} prbOpts[] = {
   {(u8*) "\003\003\012\001\002\004\005\264\010\012\377\377\377\377\000\000\000\000\004\002", 20},
-  {(u8*) "\002\004\005\170\003\003\000\001\004\002\010\012\377\377\377\377\000\000\000\000", 20},
+  {(u8*) "\002\004\005\170\003\003\000\004\002\010\012\377\377\377\377\000\000\000\000\0", 20},
   {(u8*) "\010\012\377\377\377\377\000\000\000\000\001\001\003\003\005\001\002\004\002\200", 20},
-  {(u8*) "\004\002\010\012\377\377\377\377\000\000\000\000\003\003\012\001", 16},
+  {(u8*) "\004\002\010\012\377\377\377\377\000\000\000\000\003\003\012\0", 16},
-  {(u8*) "\002\004\002\030\004\002\010\012\377\377\377\377\000\000\000\000\003\003\012\001", 20},
+  {(u8*) "\002\004\002\030\004\002\010\012\377\377\377\377\000\000\000\000\003\003\012\0", 20},
-  {(u8*) "\002\004\001\011\004\002\001\001\010\012\377\377\377\377\000\000\000\000\001\000", 20},
+  {(u8*) "\002\004\001\011\004\002\010\012\377\377\377\377\000\000\000\000", 16},
   {(u8*) "\003\003\012\001\002\004\005\264\004\002\001\001", 12},
-  {(u8*) "\003\003\012\001\002\004\001\011\010\012\377\377\377\377\000\000\000\000\004\002", 20}
+  {(u8*) "\003\003\012\001\002\004\001\011\010\012\377\377\377\377\000\000\000\000\004\002", 20},
+  {(u8*) "\003\003\012\001\002\004\001\011\010\012\377\377\377\377\000\000\000\000\004\002", 20},
+  {(u8*) "\003\003\012\001\002\004\001\011\010\012\377\377\377\377\000\000\000\000\004\002", 20},
+  {(u8*) "\003\003\012\001\002\004\001\011\010\012\377\377\377\377\000\000\000\000\004\002", 20},
+  {(u8*) "\003\003\012\001\002\004\001\011\010\012\377\377\377\377\000\000\000\000\004\002", 20},
+  {(u8*) "\003\003\017\001\002\004\001\011\010\012\377\377\377\377\000\000\000\000\004\002", 20}
 };
 
+/* Numbering is the same as for prbOpts[] */
+u16 prbWindowSz[] = { 1, 63, 4, 4, 16, 512, 3, 128, 256, 1024, 31337, 32768, 65535 };
+
+
 /* A global now. Updated after potentially meaningful delays. This can
  * be used to save a call to gettimeofday()
  */
@@ -1148,7 +1259,7 @@ void HostOsScan::sendTSeqProbe(HostOsScanStats *hss, int probeNo) {
   send_tcp_raw_decoys(rawsd, ethptr, hss->target->v4hostip(), o.ttl, false,
                       tcpPortBase + probeNo, hss->openTCPPort,
                       tcpSeqBase + probeNo, tcpAck, 0,
-                      TH_SYN, 0, 0, prbOpts[probeNo].val, prbOpts[probeNo].len,
+                      TH_SYN, prbWindowSz[probeNo], 0, prbOpts[probeNo].val, prbOpts[probeNo].len,
 		      NULL, 0);
 
   hss->seq_send_times[probeNo] = now;  
@@ -1156,13 +1267,13 @@ void HostOsScan::sendTSeqProbe(HostOsScanStats *hss, int probeNo) {
 
 void HostOsScan::sendTOpsProbe(HostOsScanStats *hss, int probeNo) {
   assert(hss);
-  assert(probeNo>=0 && probeNo<6);
+  assert(probeNo>=0 && probeNo< NUM_SEQ_SAMPLES);
 
   if(hss->openTCPPort == (unsigned long)-1) return;
   
   send_tcp_raw_decoys(rawsd, ethptr, hss->target->v4hostip(), o.ttl, false,
                       tcpPortBase + NUM_SEQ_SAMPLES + probeNo, hss->openTCPPort, tcpSeqBase,
-                      tcpAck, 0, TH_SYN, 0, 0, prbOpts[probeNo].val, prbOpts[probeNo].len, NULL, 0);
+                      tcpAck, 0, TH_SYN, prbWindowSz[probeNo], 0, prbOpts[probeNo].val, prbOpts[probeNo].len, NULL, 0);
 }
 
 void HostOsScan::sendTEcnProbe(HostOsScanStats *hss) {
@@ -1172,7 +1283,7 @@ void HostOsScan::sendTEcnProbe(HostOsScanStats *hss) {
   
   send_tcp_raw_decoys(rawsd, ethptr, hss->target->v4hostip(), o.ttl, false,
                       tcpPortBase + NUM_SEQ_SAMPLES + 6, hss->openTCPPort, tcpSeqBase, 0, 8,
-                      TH_CWR|TH_ECE|TH_SYN, 0, 63479, prbOpts[6].val, prbOpts[6].len, NULL, 0);
+                      TH_CWR|TH_ECE|TH_SYN, prbWindowSz[6], 63477, prbOpts[6].val, prbOpts[6].len, NULL, 0);
 }
 
 void HostOsScan::sendT1_7Probe(HostOsScanStats *hss, int probeNo) {
@@ -1186,43 +1297,49 @@ void HostOsScan::sendT1_7Probe(HostOsScanStats *hss, int probeNo) {
     if(hss->openTCPPort == (unsigned long)-1) return;
     send_tcp_raw_decoys(rawsd, ethptr, hss->target->v4hostip(), o.ttl, false,
                         port_base, hss->openTCPPort, tcpSeqBase, tcpAck, 0,
-                        TH_SYN, 0, 0, prbOpts[0].val, prbOpts[0].len, NULL, 0);
+                        TH_SYN, prbWindowSz[0], 0, prbOpts[0].val, 
+			prbOpts[0].len, NULL, 0);
     break;
   case 1: /* T2 */
     if(hss->openTCPPort == (unsigned long)-1) return;
     send_tcp_raw_decoys(rawsd, ethptr, hss->target->v4hostip(), o.ttl, true,
                         port_base + 1, hss->openTCPPort, tcpSeqBase, tcpAck, 0,
-                        0, 0, 0, prbOpts[7].val, prbOpts[7].len, NULL, 0);
+                        0, prbWindowSz[7], 0, prbOpts[7].val, prbOpts[7].len, NULL, 0);
     break;
   case 2: /* T3 */
     if(hss->openTCPPort == (unsigned long)-1) return;
     send_tcp_raw_decoys(rawsd, ethptr, hss->target->v4hostip(), o.ttl, false,
                         port_base + 2, hss->openTCPPort, tcpSeqBase, tcpAck, 0,
-                        TH_SYN|TH_FIN|TH_URG|TH_PUSH, 0, 0, prbOpts[7].val, prbOpts[7].len, NULL, 0);
+                        TH_SYN|TH_FIN|TH_URG|TH_PUSH, prbWindowSz[8], 0, 
+			prbOpts[8].val, prbOpts[8].len, NULL, 0);
     break;
   case 3: /* T4 */
     if(hss->openTCPPort == (unsigned long)-1) return;
     send_tcp_raw_decoys(rawsd, ethptr, hss->target->v4hostip(), o.ttl, true,
                         port_base + 3, hss->openTCPPort, tcpSeqBase, tcpAck, 0,
-                        TH_ACK, 0, 0, prbOpts[7].val, prbOpts[7].len, NULL, 0);
+                        TH_ACK, prbWindowSz[9], 0, prbOpts[9].val, 
+			prbOpts[9].len, NULL, 0);
     break;
   case 4: /* T5 */
     if(hss->closedTCPPort == (unsigned long)-1) return;
     send_tcp_raw_decoys(rawsd, ethptr, hss->target->v4hostip(), o.ttl, false,
                         port_base + 4, hss->closedTCPPort, tcpSeqBase, tcpAck, 0,
-                        TH_SYN, 0, 0, prbOpts[7].val, prbOpts[7].len, NULL, 0);
+                        TH_SYN, prbWindowSz[10], 0, prbOpts[10].val, 
+			prbOpts[10].len, NULL, 0);
     break;
   case 5: /* T6 */
     if(hss->closedTCPPort == (unsigned long)-1) return;
     send_tcp_raw_decoys(rawsd, ethptr, hss->target->v4hostip(), o.ttl, true,
                         port_base + 5, hss->closedTCPPort, tcpSeqBase, tcpAck, 0,
-                        TH_ACK, 0, 0, prbOpts[7].val, prbOpts[7].len, NULL, 0);
+                        TH_ACK, prbWindowSz[11], 0, prbOpts[11].val, 
+			prbOpts[11].len, NULL, 0);
     break;
   case 6: /* T7 */
     if(hss->closedTCPPort == (unsigned long)-1) return;
     send_tcp_raw_decoys(rawsd, ethptr, hss->target->v4hostip(), o.ttl, false,
                         port_base + 6, hss->closedTCPPort, tcpSeqBase, tcpAck, 0,
-                        TH_FIN|TH_PUSH|TH_URG, 0, 0, prbOpts[7].val, prbOpts[7].len, NULL, 0);
+                        TH_FIN|TH_PUSH|TH_URG, prbWindowSz[12], 0, 
+			prbOpts[12].val, prbOpts[12].len, NULL, 0);
     break;
   }
 }
@@ -1324,7 +1441,7 @@ bool HostOsScan::processResp(HostOsScanStats *hss, struct ip *ip, unsigned int l
 
     /* Is it an icmp echo reply? */
     if (icmp->icmp_type == ICMP_ECHOREPLY) {
-      testno = icmp->icmp_id - icmpEchoId;
+      testno = ntohs(icmp->icmp_id) - icmpEchoId;
 	  if (testno==0 || testno==1) {
 		isPktUseful = processTIcmpResp(hss, ip, testno);
 		if(isPktUseful) {
@@ -1644,38 +1761,38 @@ void HostOsScan::makeTSeqFP(HostOsScanStats *hss) {
       break;
     }
 
-	good_tcp_ipid_num = 0;
+    good_tcp_ipid_num = 0;
-	good_icmp_ipid_num = 0;
+    good_icmp_ipid_num = 0;
     
-	for(i=0; i < NUM_SEQ_SAMPLES; i++) {
+    for(i=0; i < NUM_SEQ_SAMPLES; i++) {
-	  if (hss->ipid.tcp_ipids[i] != -1) {
+      if (hss->ipid.tcp_ipids[i] != -1) {
-		if (good_tcp_ipid_num < i) {
+	if (good_tcp_ipid_num < i) {
-		  hss->ipid.tcp_ipids[good_tcp_ipid_num] = hss->ipid.tcp_ipids[i];
+	  hss->ipid.tcp_ipids[good_tcp_ipid_num] = hss->ipid.tcp_ipids[i];
-		}
-		good_tcp_ipid_num++;
-	  }
-
-	  if (hss->ipid.icmp_ipids[i] != -1) {
-		if (good_icmp_ipid_num < i) {
-		  hss->ipid.icmp_ipids[good_icmp_ipid_num] = hss->ipid.icmp_ipids[i];
-		}
-		good_icmp_ipid_num++;
-	  }
 	}
+	good_tcp_ipid_num++;
+      }
       
-	if (good_tcp_ipid_num >= 3) {
+      if (hss->ipid.icmp_ipids[i] != -1) {
-	  tcp_ipid_seqclass = get_ipid_sequence(good_tcp_ipid_num, hss->ipid.tcp_ipids, islocalhost(hss->target->v4hostip()));
+	if (good_icmp_ipid_num < i) {
-	} else {
+	  hss->ipid.icmp_ipids[good_icmp_ipid_num] = hss->ipid.icmp_ipids[i];
-	  tcp_ipid_seqclass = IPID_SEQ_UNKNOWN;
 	}
-	/* Only print tcp ipid seqclass in the final report. */
+	good_icmp_ipid_num++;
-	hss->si.ipid_seqclass = tcp_ipid_seqclass;
+      }
+    }
     
-	if (good_icmp_ipid_num >= 2) {
+    if (good_tcp_ipid_num >= 3) {
-	  icmp_ipid_seqclass = get_ipid_sequence(good_icmp_ipid_num, hss->ipid.icmp_ipids, islocalhost(hss->target->v4hostip()));
+      tcp_ipid_seqclass = get_ipid_sequence(good_tcp_ipid_num, hss->ipid.tcp_ipids, islocalhost(hss->target->v4hostip()));
-	} else {
+    } else {
-	  icmp_ipid_seqclass = IPID_SEQ_UNKNOWN;
+      tcp_ipid_seqclass = IPID_SEQ_UNKNOWN;
-	}
+    }
+    /* Only print tcp ipid seqclass in the final report. */
+    hss->si.ipid_seqclass = tcp_ipid_seqclass;
+    
+    if (good_icmp_ipid_num >= 2) {
+      icmp_ipid_seqclass = get_ipid_sequence(good_icmp_ipid_num, hss->ipid.icmp_ipids, islocalhost(hss->target->v4hostip()));
+    } else {
+      icmp_ipid_seqclass = IPID_SEQ_UNKNOWN;
+    }
     
     /* TI: TCP IP ID sequence generation algorithm */
     switch(tcp_ipid_seqclass) {
@@ -2550,8 +2667,8 @@ bool HostOsScan::processTIcmpResp(HostOsScanStats *hss, struct ip *ip, int reply
    * O. Other.
    */
   AVs[5].attribute = "SI";
-  value1 = icmp1->icmp_seq;
+  value1 = ntohs(icmp1->icmp_seq);
-  value2 = icmp2->icmp_seq;
+  value2 = ntohs(icmp2->icmp_seq);
   if (value1 == value2) {
     if (value1 == 0)
       strcpy(AVs[current_testno].value, "Z");
@@ -2840,8 +2957,9 @@ int OsScanInfo::removeCompletedHosts() {
   return hostsRemoved;
 }
 
-int send_icmp_echo_probe(int sd, struct eth_nfo *eth, const struct in_addr *victim,
+int send_icmp_echo_probe(int sd, struct eth_nfo *eth, 
-                         u8 tos, bool df, u8 pcode, unsigned short id, u16 seq, u16 datalen) {
+			 const struct in_addr *victim, u8 tos, bool df,
+			 u8 pcode, unsigned short id, u16 seq, u16 datalen) {
   u8 *packet = NULL;
   u32 packetlen = 0;
   int decoy;
@@ -2864,7 +2982,7 @@ int send_closedudp_probe_2(struct udpprobeinfo &upi, int sd,
                            struct eth_nfo *eth,  const struct in_addr *victim,
 						   int ttl, u16 sport, u16 dport) {
   static int myttl = 0;
-  static u8 patternbyte = 0x41; /* character 'A' */
+  static u8 patternbyte = 0x43; /* character 'C' */
   static u16 id = 0x1042; 
   u8 packet[328]; /* 20 IP hdr + 8 UDP hdr + 300 data */
   struct ip *ip = (struct ip *) packet;

osscan2.h

@@ -1,4 +1,105 @@
 
+/***************************************************************************
+ * osscan2.h -- Header info for 2nd Generation OS detection via TCP/IP     *
+ * fingerprinting.  For more information on how this works in Nmap, see    *
+ * http://insecure.org/osdetect/                                           *
+ *                                                                         *
+ ***********************IMPORTANT NMAP LICENSE TERMS************************
+ *                                                                         *
+ * The Nmap Security Scanner is (C) 1996-2004 Insecure.Com LLC. Nmap       *
+ * is also a registered trademark of Insecure.Com LLC.  This program is    *
+ * free software; you may redistribute and/or modify it under the          *
+ * terms of the GNU General Public License as published by the Free        *
+ * Software Foundation; Version 2.  This guarantees your right to use,     *
+ * modify, and redistribute this software under certain conditions.  If    *
+ * you wish to embed Nmap technology into proprietary software, we may be  *
+ * willing to sell alternative licenses (contact sales@insecure.com).      *
+ * Many security scanner vendors already license Nmap technology such as  *
+ * our remote OS fingerprinting database and code, service/version         *
+ * detection system, and port scanning code.                               *
+ *                                                                         *
+ * Note that the GPL places important restrictions on "derived works", yet *
+ * it does not provide a detailed definition of that term.  To avoid       *
+ * misunderstandings, we consider an application to constitute a           *
+ * "derivative work" for the purpose of this license if it does any of the *
+ * following:                                                              *
+ * o Integrates source code from Nmap                                      *
+ * o Reads or includes Nmap copyrighted data files, such as                *
+ *   nmap-os-fingerprints or nmap-service-probes.                          *
+ * o Executes Nmap and parses the results (as opposed to typical shell or  *
+ *   execution-menu apps, which simply display raw Nmap output and so are  *
+ *   not derivative works.)                                                * 
+ * o Integrates/includes/aggregates Nmap into a proprietary executable     *
+ *   installer, such as those produced by InstallShield.                   *
+ * o Links to a library or executes a program that does any of the above   *
+ *                                                                         *
+ * The term "Nmap" should be taken to also include any portions or derived *
+ * works of Nmap.  This list is not exclusive, but is just meant to        *
+ * clarify our interpretation of derived works with some common examples.  *
+ * These restrictions only apply when you actually redistribute Nmap.  For *
+ * example, nothing stops you from writing and selling a proprietary       *
+ * front-end to Nmap.  Just distribute it by itself, and point people to   *
+ * http://www.insecure.org/nmap/ to download Nmap.                         *
+ *                                                                         *
+ * We don't consider these to be added restrictions on top of the GPL, but *
+ * just a clarification of how we interpret "derived works" as it applies  *
+ * to our GPL-licensed Nmap product.  This is similar to the way Linus     *
+ * Torvalds has announced his interpretation of how "derived works"        *
+ * applies to Linux kernel modules.  Our interpretation refers only to     *
+ * Nmap - we don't speak for any other GPL products.                       *
+ *                                                                         *
+ * If you have any questions about the GPL licensing restrictions on using *
+ * Nmap in non-GPL works, we would be happy to help.  As mentioned above,  *
+ * we also offer alternative license to integrate Nmap into proprietary    *
+ * applications and appliances.  These contracts have been sold to many    *
+ * security vendors, and generally include a perpetual license as well as  *
+ * providing for priority support and updates as well as helping to fund   *
+ * the continued development of Nmap technology.  Please email             *
+ * sales@insecure.com for further information.                             *
+ *                                                                         *
+ * As a special exception to the GPL terms, Insecure.Com LLC grants        *
+ * permission to link the code of this program with any version of the     *
+ * OpenSSL library which is distributed under a license identical to that  *
+ * listed in the included Copying.OpenSSL file, and distribute linked      *
+ * combinations including the two. You must obey the GNU GPL in all        *
+ * respects for all of the code used other than OpenSSL.  If you modify    *
+ * this file, you may extend this exception to your version of the file,   *
+ * but you are not obligated to do so.                                     *
+ *                                                                         *
+ * If you received these files with a written license agreement or         *
+ * contract stating terms other than the terms above, then that            *
+ * alternative license agreement takes precedence over these comments.     *
+ *                                                                         *
+ * Source is provided to this software because we believe users have a     *
+ * right to know exactly what a program is going to do before they run it. *
+ * This also allows you to audit the software for security holes (none     *
+ * have been found so far).                                                *
+ *                                                                         *
+ * Source code also allows you to port Nmap to new platforms, fix bugs,    *
+ * and add new features.  You are highly encouraged to send your changes   *
+ * to fyodor@insecure.org for possible incorporation into the main         *
+ * distribution.  By sending these changes to Fyodor or one the            *
+ * Insecure.Org development mailing lists, it is assumed that you are      *
+ * offering Fyodor and Insecure.Com LLC the unlimited, non-exclusive right *
+ * to reuse, modify, and relicense the code.  Nmap will always be          *
+ * available Open Source, but this is important because the inability to   *
+ * relicense code has caused devastating problems for other Free Software  *
+ * projects (such as KDE and NASM).  We also occasionally relicense the    *
+ * code to third parties as discussed above.  If you wish to specify       *
+ * special license conditions of your contributions, just say so when you  *
+ * send them.                                                              *
+ *                                                                         *
+ * This program is distributed in the hope that it will be useful, but     *
+ * WITHOUT ANY WARRANTY; without even the implied warranty of              *
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU       *
+ * General Public License for more details at                              *
+ * http://www.gnu.org/copyleft/gpl.html , or in the COPYING file included  *
+ * with Nmap.                                                              *
+ *                                                                         *
+ ***************************************************************************/
+
+/* $Id: osscan.h 3636 2006-07-04 23:04:56Z fyodor $ */
+
 #ifndef OSSCAN2_H
 #define OSSCAN2_H
 

tcpip.cc

@@ -901,7 +901,7 @@ assert(victim);
 assert(source);
 
 if (optlen % 4) {
-  fatal("build_tcp_raw() called with an option length argument of %d which is illegal because it is not divisible by 4", optlen);
+  fatal("build_tcp_raw() called with an option length argument of %d which is illegal because it is not divisible by 4.  Just add \\0 padding to the end.", optlen);
 }
 
 /* Time to live */
@@ -1164,10 +1164,12 @@ int send_ip_packet(int sd, struct eth_nfo *eth, u8 *packet, unsigned int packetl
    packet contents, and then returns that buffer.  The packet is not
    actually sent by this function.  Caller must delete the buffer when
    finished with the packet.  The packet length is returned in
-   packetlen, which must be a valid int pointer. */
+   packetlen, which must be a valid int pointer.  The id/seq will be converted
+   to network byte order (if it differs from HBO) */
 u8 *build_icmp_raw(const struct in_addr *source, const struct in_addr *victim, 
-		   int ttl, u16 ipid, u8 tos, bool df, u16 seq, unsigned short id, u8 ptype, 
+		   int ttl, u16 ipid, u8 tos, bool df, u16 seq, 
-		   u8 pcode, char *data, u16 datalen, u32 *packetlen) {
+		   unsigned short id, u8 ptype, u8 pcode, char *data, 
+		   u16 datalen, u32 *packetlen) {
 
 struct ppkt {
   u8 type;
@@ -1205,8 +1207,8 @@ char *ping = (char *) &pingpkt;
  }
 /* Fill out the ping packet */
 
-pingpkt.id = id;
+ pingpkt.id = htons(id);
-pingpkt.seq = seq;
+ pingpkt.seq = htons(seq);
 pingpkt.checksum = 0;
 pingpkt.checksum = in_cksum((unsigned short *)ping, icmplen);
 

tcpip.h

@@ -549,12 +549,14 @@ u8 *build_udp_raw(struct in_addr *source, const struct in_addr *victim,
  		  int ttl, u16 sport, u16 dport, u16 ipid, char *data, 
 		  u16 datalen, u32 *packetlen);
 
-/* Builds an ICMP packet (including an IP header) by packing the fields
+/* Builds an ICMP packet (including an IP header) by packing the
-   with the given information.  It allocates a new buffer to store the
+   fields with the given information.  It allocates a new buffer to
-   packet contents, and then returns that buffer.  The packet is not
+   store the packet contents, and then returns that buffer.  The
-   actually sent by this function.  Caller must delete the buffer when
+   packet is not actually sent by this function.  Caller must delete
-   finished with the packet.  The packet length is returned in
+   the buffer when finished with the packet.  The packet length is
-   packetlen, which must be a valid int pointer. */
+   returned in packetlen, which must be a valid int pointer. The
+   id/seq will be converted to network byte order (if it differs from
+   HBO) */
 u8 *build_icmp_raw(const struct in_addr *source, const struct in_addr *victim, 
 		   int ttl, u16 ipid, u8 tos, bool df, u16 seq, unsigned short id, u8 ptype, 
 		   u8 pcode, char *data, u16 datalen, u32 *packetlen);