Added some helper functions to set options to DHCP PDU. Added LGPL notice to dhcp.cpp

include/dhcp.h

@@ -29,13 +29,15 @@
 
 namespace Tins {
     
-    /** \brief Class that represents the DHCP PDU.
+    /** 
+     * \brief Class that represents the DHCP PDU.
      * 
      * The end option is added automatically at the end of the option list.
      */
     class DHCP : public BootP {
     public:
-        /** \brief DHCP flags.
+        /** 
+         * \brief DHCP flags.
          */
         enum Flags {
             DHCPDISCOVER = 1,
@@ -48,7 +50,8 @@ namespace Tins {
             DHCPINFORM   = 8
         };
         
-        /** \brief DHCP options enum.
+        /** 
+         * \brief DHCP options enum.
          */
         enum Options {
             PAD,
@@ -123,7 +126,8 @@ namespace Tins {
             END	= 255
         };
         
-        /** \brief DHCP options struct.
+        /** 
+         * \brief DHCP options struct.
          */
         struct DHCPOption {
             uint8_t option, length;
@@ -132,14 +136,16 @@ namespace Tins {
             DHCPOption(uint8_t opt, uint8_t len, uint8_t *val);
         };
         
-        /** \brief Creates an instance of DHCP.
+        /** 
+         * \brief Creates an instance of DHCP.
          * 
          * This sets the hwtype and hlen fields to match the ethernet
          * type and length.
          */
         DHCP();
         
-        /** \brief Adds a new option to this DHCP PDU.
+        /** 
+         * \brief Adds a new option to this DHCP PDU.
          * 
          * This copies the value buffer. Adding options may fail if
          * there's not enough size to hold a new option.
@@ -150,10 +156,26 @@ namespace Tins {
          */
         bool add_option(Options opt, uint8_t len, uint8_t *val);
         
-        /** \brief Adds a type option the the option list.
+        /** 
+         * \brief Adds a type option the the option list.
          * \param type The type of this DHCP PDU.
+         * \return True if the option was added successfully. \sa DHCP::add_option
          */
-        void add_type_option(Flags type);
+        bool add_type_option(Flags type);
+        
+        /** 
+         * \brief Adds a server identifier option.
+         * \param ip The ip of the server.
+         * \return True if the option was added successfully. \sa DHCP::add_option
+         */
+        bool add_server_identifier(uint32_t ip);
+        
+        /** 
+         * \brief Adds an IP address lease time option.
+         * \param time The lease time.
+         * \return True if the option was added successfully. \sa DHCP::add_option
+         */
+        bool add_lease_time(uint32_t time);
         
         /** \brief Getter for the options list.
          * \return The option list.
@@ -166,7 +188,8 @@ namespace Tins {
          */
         PDUType pdu_type() const { return PDU::UDP; }
         
-        /** \brief Getter for the header size.
+        /** 
+         * \brief Getter for the header size.
          * \return Returns the BOOTP header size.
          * \sa PDU::header_size
          */ 

src/dhcp.cpp

@@ -1,3 +1,24 @@
+/*
+ * libtins is a net packet wrapper library for crafting and
+ * interpreting sniffed packets.
+ *
+ * Copyright (C) 2011 Nasel
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library 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
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
+ */
+
 #include <cstring>
 #include <cassert>
 #include <iostream> //borrame
@@ -28,8 +49,17 @@ bool Tins::DHCP::add_option(Options opt, uint8_t len, uint8_t *val) {
     return true;
 }
 
-void Tins::DHCP::add_type_option(Flags type) {
-    add_option(DHCP_MESSAGE_TYPE, 1, (uint8_t*)&type);
+bool Tins::DHCP::add_type_option(Flags type) {
+    return add_option(DHCP_MESSAGE_TYPE, 1, (uint8_t*)&type);
+}
+
+bool Tins::DHCP::add_server_identifier(uint32_t ip) {
+    return add_option(DHCP_SERVER_IDENTIFIER, 4, (uint8_t*)&ip);
+}
+
+bool Tins::DHCP::add_lease_time(uint32_t time) {
+    time = Utils::net_to_host_l(time);
+    return add_option(DHCP_LEASE_TIME, 4, (uint8_t*)&time);
 }
 
 uint32_t Tins::DHCP::header_size() const {
@@ -43,10 +73,12 @@ void Tins::DHCP::write_serialization(uint8_t *buffer, uint32_t total_sz, const P
     for(std::list<DHCPOption>::const_iterator it = _options.begin(); it != _options.end(); ++it) {
         *(ptr++) = it->option;
         *(ptr++) = it->length;
-        std::memcpy(ptr++, it->value, it->length);
+        std::memcpy(ptr, it->value, it->length);
+        ptr += it->length;
     }
     result[_size-1] = END;
     vend(result, _size);
     BootP::write_serialization(buffer, total_sz, parent);
+    delete[] result;
 }
 

src/ip.cpp

@@ -58,6 +58,7 @@ void Tins::IP::init_ip_fields() {
     _ip.version = 4;
     _ip.ihl = sizeof(iphdr) / sizeof(uint32_t);
     _ip.ttl = DEFAULT_TTL;
+    _ip.id = Utils::net_to_host_s(1);
     _options_size = 0;
     _padded_options_size = 0;
 }