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      1 /*
      2  * libjingle
      3  * Copyright 2004--2005, Google Inc.
      4  *
      5  * Redistribution and use in source and binary forms, with or without
      6  * modification, are permitted provided that the following conditions are met:
      7  *
      8  *  1. Redistributions of source code must retain the above copyright notice,
      9  *     this list of conditions and the following disclaimer.
     10  *  2. Redistributions in binary form must reproduce the above copyright notice,
     11  *     this list of conditions and the following disclaimer in the documentation
     12  *     and/or other materials provided with the distribution.
     13  *  3. The name of the author may not be used to endorse or promote products
     14  *     derived from this software without specific prior written permission.
     15  *
     16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
     17  * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
     18  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO
     19  * EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
     20  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
     21  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
     22  * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
     23  * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
     24  * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
     25  * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     26  */
     27 
     28 #ifndef TALK_P2P_BASE_CANDIDATE_H_
     29 #define TALK_P2P_BASE_CANDIDATE_H_
     30 
     31 #include <limits.h>
     32 #include <math.h>
     33 
     34 #include <string>
     35 #include <sstream>
     36 #include <iomanip>
     37 
     38 #include "talk/base/basictypes.h"
     39 #include "talk/base/socketaddress.h"
     40 #include "talk/p2p/base/constants.h"
     41 
     42 namespace cricket {
     43 
     44 // Candidate for ICE based connection discovery.
     45 
     46 class Candidate {
     47  public:
     48   // TODO: Match the ordering and param list as per RFC 5245
     49   // candidate-attribute syntax. http://tools.ietf.org/html/rfc5245#section-15.1
     50   Candidate() : component_(0), priority_(0), generation_(0) {}
     51   Candidate(const std::string& id, int component, const std::string& protocol,
     52             const talk_base::SocketAddress& address, uint32 priority,
     53             const std::string& username, const std::string& password,
     54             const std::string& type, const std::string& network_name,
     55             uint32 generation, const std::string& foundation)
     56       : id_(id), component_(component), protocol_(protocol), address_(address),
     57         priority_(priority), username_(username), password_(password),
     58         type_(type), network_name_(network_name), generation_(generation),
     59         foundation_(foundation) {
     60   }
     61 
     62   const std::string & id() const { return id_; }
     63   void set_id(const std::string & id) { id_ = id; }
     64 
     65   int component() const { return component_; }
     66   void set_component(int component) { component_ = component; }
     67 
     68   const std::string & protocol() const { return protocol_; }
     69   void set_protocol(const std::string & protocol) { protocol_ = protocol; }
     70 
     71   const talk_base::SocketAddress & address() const { return address_; }
     72   void set_address(const talk_base::SocketAddress & address) {
     73     address_ = address;
     74   }
     75 
     76   uint32 priority() const { return priority_; }
     77   void set_priority(const uint32 priority) { priority_ = priority; }
     78 
     79 //  void set_type_preference(uint32 type_preference) {
     80 //    priority_ = GetPriority(type_preference);
     81 //  }
     82 
     83   // Maps old preference (which was 0.0-1.0) to match priority (which
     84   // is 0-2^32-1) to to match RFC 5245, section 4.1.2.1.  Also see
     85   // https://docs.google.com/a/google.com/document/d/
     86   // 1iNQDiwDKMh0NQOrCqbj3DKKRT0Dn5_5UJYhmZO-t7Uc/edit
     87   float preference() const {
     88     // The preference value is clamped to two decimal precision.
     89     return static_cast<float>(((priority_ >> 24) * 100 / 127) / 100.0);
     90   }
     91 
     92   void set_preference(float preference) {
     93     // Limiting priority to UINT_MAX when value exceeds uint32 max.
     94     // This can happen for e.g. when preference = 3.
     95     uint64 prio_val = static_cast<uint64>(preference * 127) << 24;
     96     priority_ = static_cast<uint32>(
     97       talk_base::_min(prio_val, static_cast<uint64>(UINT_MAX)));
     98   }
     99 
    100   const std::string & username() const { return username_; }
    101   void set_username(const std::string & username) { username_ = username; }
    102 
    103   const std::string & password() const { return password_; }
    104   void set_password(const std::string & password) { password_ = password; }
    105 
    106   const std::string & type() const { return type_; }
    107   void set_type(const std::string & type) { type_ = type; }
    108 
    109   const std::string & network_name() const { return network_name_; }
    110   void set_network_name(const std::string & network_name) {
    111     network_name_ = network_name;
    112   }
    113 
    114   // Candidates in a new generation replace those in the old generation.
    115   uint32 generation() const { return generation_; }
    116   void set_generation(uint32 generation) { generation_ = generation; }
    117   const std::string generation_str() const {
    118     std::ostringstream ost;
    119     ost << generation_;
    120     return ost.str();
    121   }
    122   void set_generation_str(const std::string& str) {
    123     std::istringstream ist(str);
    124     ist >> generation_;
    125   }
    126 
    127   const std::string& foundation() const {
    128     return foundation_;
    129   }
    130 
    131   void set_foundation(const std::string& foundation) {
    132     foundation_ = foundation;
    133   }
    134 
    135   const talk_base::SocketAddress & related_address() const {
    136     return related_address_;
    137   }
    138   void set_related_address(
    139       const talk_base::SocketAddress & related_address) {
    140     related_address_ = related_address;
    141   }
    142 
    143   // Determines whether this candidate is equivalent to the given one.
    144   bool IsEquivalent(const Candidate& c) const {
    145     // We ignore the network name, since that is just debug information, and
    146     // the priority, since that should be the same if the rest is (and it's
    147     // a float so equality checking is always worrisome).
    148     return (id_ == c.id_) &&
    149            (component_ == c.component_) &&
    150            (protocol_ == c.protocol_) &&
    151            (address_ == c.address_) &&
    152            (username_ == c.username_) &&
    153            (password_ == c.password_) &&
    154            (type_ == c.type_) &&
    155            (generation_ == c.generation_) &&
    156            (foundation_ == c.foundation_) &&
    157            (related_address_ == c.related_address_);
    158   }
    159 
    160   std::string ToString() const {
    161     return ToStringInternal(false);
    162   }
    163 
    164   std::string ToSensitiveString() const {
    165     return ToStringInternal(true);
    166   }
    167 
    168   uint32 GetPriority(uint32 type_preference,
    169                      int network_adapter_preference) const {
    170     // RFC 5245 - 4.1.2.1.
    171     // priority = (2^24)*(type preference) +
    172     //            (2^8)*(local preference) +
    173     //            (2^0)*(256 - component ID)
    174 
    175     // |local_preference| length is 2 bytes, 0-65535 inclusive.
    176     // In our implemenation we will partion local_preference into
    177     //              0                 1
    178     //       0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5
    179     //      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    180     //      |  NIC Pref     |    Addr Pref  |
    181     //      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    182     // NIC Type - Type of the network adapter e.g. 3G/Wifi/Wired.
    183     // Addr Pref - Address preference value as per RFC 3484.
    184     // local preference is calculated as - NIC Type << 8 | Addr_Pref.
    185 
    186     int addr_pref = IPAddressPrecedence(address_.ipaddr());
    187     int local_preference = (network_adapter_preference << 8) | addr_pref;
    188 
    189     return (type_preference << 24) |
    190            (local_preference << 8) |
    191            (256 - component_);
    192   }
    193 
    194  private:
    195   std::string ToStringInternal(bool sensitive) const {
    196     std::ostringstream ost;
    197     std::string address = sensitive ? address_.ToSensitiveString() :
    198                                       address_.ToString();
    199     ost << "Cand[" << foundation_ << ":" << component_ << ":"
    200         << protocol_ << ":" << priority_ << ":"
    201         << address << ":" << type_ << ":" << related_address_ << ":"
    202         << username_ << ":" << password_ << "]";
    203     return ost.str();
    204   }
    205 
    206   std::string id_;
    207   int component_;
    208   std::string protocol_;
    209   talk_base::SocketAddress address_;
    210   uint32 priority_;
    211   std::string username_;
    212   std::string password_;
    213   std::string type_;
    214   std::string network_name_;
    215   uint32 generation_;
    216   std::string foundation_;
    217   talk_base::SocketAddress related_address_;
    218 };
    219 
    220 }  // namespace cricket
    221 
    222 #endif  // TALK_P2P_BASE_CANDIDATE_H_
    223