srs/trunk/3rdparty/srt-1-fit/srtcore/socketconfig.h

/*
 * SRT - Secure, Reliable, Transport
 * Copyright (c) 2018 Haivision Systems Inc.
 * 
 * This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/.
 * 
 */

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  following disclaimer.

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/*****************************************************************************
written by
   Haivision Systems Inc.
*****************************************************************************/

#ifndef INC_SRT_SOCKETCONFIG_H
#define INC_SRT_SOCKETCONFIG_H

#include "platform_sys.h"
#ifdef SRT_ENABLE_BINDTODEVICE
#include <linux/if.h>
#endif
#include <string>
#include "haicrypt.h"
#include "congctl.h"
#include "packet.h"
#include "handshake.h"
#include "logger_defs.h"
#include "packetfilter.h"

// SRT Version constants
#define SRT_VERSION_UNK     0
#define SRT_VERSION_MAJ1    0x010000            /* Version 1 major */
#define SRT_VERSION_MAJ(v) (0xFF0000 & (v))     /* Major number ensuring backward compatibility */
#define SRT_VERSION_MIN(v) (0x00FF00 & (v))
#define SRT_VERSION_PCH(v) (0x0000FF & (v))

// NOTE: SRT_VERSION is primarily defined in the build file.
extern const int32_t SRT_DEF_VERSION;

namespace srt
{

struct CSrtMuxerConfig
{
    static const int DEF_UDP_BUFFER_SIZE = 65536;

    int  iIpTTL;
    int  iIpToS;
    int  iIpV6Only;  // IPV6_V6ONLY option (-1 if not set)
    bool bReuseAddr; // reuse an exiting port or not, for UDP multiplexer

#ifdef SRT_ENABLE_BINDTODEVICE
    std::string sBindToDevice;
#endif
    int iUDPSndBufSize; // UDP sending buffer size
    int iUDPRcvBufSize; // UDP receiving buffer size

    // NOTE: this operator is not reversable. The syntax must use:
    //  muxer_entry == socket_entry
    bool isCompatWith(const CSrtMuxerConfig& other) const
    {
#define CEQUAL(field) (field == other.field)
        return CEQUAL(iIpTTL)
            && CEQUAL(iIpToS)
            && CEQUAL(bReuseAddr)
#ifdef SRT_ENABLE_BINDTODEVICE
            && CEQUAL(sBindToDevice)
#endif
            && CEQUAL(iUDPSndBufSize)
            && CEQUAL(iUDPRcvBufSize)
            && (other.iIpV6Only == -1 || CEQUAL(iIpV6Only))
            // NOTE: iIpV6Only is not regarded because
            // this matches only in case of IPv6 with "any" address.
            // And this aspect must be checked separately because here
            // this procedure has no access to neither the address,
            // nor the IP version (family).
#undef CEQUAL
            && true;
    }

    CSrtMuxerConfig()
        : iIpTTL(-1) /* IPv4 TTL or IPv6 HOPs [1..255] (-1:undefined) */
        , iIpToS(-1) /* IPv4 Type of Service or IPv6 Traffic Class [0x00..0xff] (-1:undefined) */
        , iIpV6Only(-1)
        , bReuseAddr(true) // This is default in SRT
        , iUDPSndBufSize(DEF_UDP_BUFFER_SIZE)
        , iUDPRcvBufSize(DEF_UDP_BUFFER_SIZE)
    {
    }
};

struct CSrtConfig;

template <size_t SIZE>
class StringStorage
{
    char     stor[SIZE + 1];
    uint16_t len;

    // NOTE: default copying allowed.

public:
    StringStorage()
        : len(0)
    {
        memset(stor, 0, sizeof stor);
    }

    bool set(const char* s, size_t length)
    {
        if (length > SIZE)
            return false;

        memcpy(stor, s, length);
        stor[length] = 0;
        len          = (int) length;
        return true;
    }

    bool set(const std::string& s)
    {
        return set(s.c_str(), s.size());
    }

    size_t copy(char* s, size_t length) const
    {
        if (!s)
            return 0;

        size_t copy_len = std::min((size_t)len, length);
        memcpy(s, stor, copy_len);
        return copy_len;
    }

    std::string str() const
    {
        return len == 0 ? std::string() : std::string(stor);
    }

    const char* c_str() const
    {
        return stor;
    }

    size_t size() const { return size_t(len); }
    bool   empty() const { return len == 0; }
};

struct CSrtConfig: CSrtMuxerConfig
{
    typedef srt::sync::steady_clock::time_point time_point;
    typedef srt::sync::steady_clock::duration   duration;

    static const int
        DEF_MSS = 1500,
        DEF_FLIGHT_SIZE = 25600,
        DEF_BUFFER_SIZE = 8192, //Rcv buffer MUST NOT be bigger than Flight Flag size
        DEF_LINGER_S = 3*60,    // 3 minutes
        DEF_CONNTIMEO_S = 3;    // 3 seconds

    enum
    {
        CIPHER_MODE_AUTO = 0,
        CIPHER_MODE_AES_CTR = 1,
        CIPHER_MODE_AES_GCM = 2
    };

    static const int      COMM_RESPONSE_TIMEOUT_MS      = 5 * 1000; // 5 seconds
    static const uint32_t COMM_DEF_MIN_STABILITY_TIMEOUT_MS = 60;   // 60 ms

    // Mimimum recv flight flag size is 32 packets
    static const int    DEF_MIN_FLIGHT_PKT = 32;
    static const size_t MAX_SID_LENGTH     = 512;
    static const size_t MAX_PFILTER_LENGTH = 64;
    static const size_t MAX_CONG_LENGTH    = 16;

    int    iMSS;            // Maximum Segment Size, in bytes
    size_t zExpPayloadSize; // Expected average payload size (user option)

    // Options
    bool   bSynSending;     // Sending synchronization mode
    bool   bSynRecving;     // Receiving synchronization mode
    int    iFlightFlagSize; // Maximum number of packets in flight from the peer side
    int    iSndBufSize;     // Maximum UDT sender buffer size
    int    iRcvBufSize;     // Maximum UDT receiver buffer size
    linger Linger;          // Linger information on close
    bool   bRendezvous;     // Rendezvous connection mode

    duration tdConnTimeOut; // connect timeout in milliseconds
    bool     bDriftTracer;
    int      iSndTimeOut; // sending timeout in milliseconds
    int      iRcvTimeOut; // receiving timeout in milliseconds
    int64_t  llMaxBW;     // maximum data transfer rate (threshold)
#ifdef ENABLE_MAXREXMITBW
    int64_t  llMaxRexmitBW; // maximum bandwidth limit for retransmissions (Bytes/s).
#endif

    // These fields keep the options for encryption
    // (SRTO_PASSPHRASE, SRTO_PBKEYLEN). Crypto object is
    // created later and takes values from these.
    HaiCrypt_Secret CryptoSecret;
    int             iSndCryptoKeyLen;

    // XXX Consider removing. The bDataSender stays here
    // in order to maintain the HS side selection in HSv4.
    bool bDataSender;

    bool     bMessageAPI;
    bool     bTSBPD;        // Whether AGENT will do TSBPD Rx (whether peer does, is not agent's problem)
    int      iRcvLatency;   // Agent's Rx latency
    int      iPeerLatency;  // Peer's Rx latency for the traffic made by Agent's Tx.
    bool     bTLPktDrop;    // Whether Agent WILL DO TLPKTDROP on Rx.
    int      iSndDropDelay; // Extra delay when deciding to snd-drop for TLPKTDROP, -1 to off
    bool     bEnforcedEnc;  // Off by default. When on, any connection other than nopw-nopw & pw1-pw1 is rejected.
    int      iGroupConnect;    // 1 - allow group connections
    int      iPeerIdleTimeout_ms; // Timeout for hearing anything from the peer (ms).
    uint32_t uMinStabilityTimeout_ms;
    int      iRetransmitAlgo;
    int      iCryptoMode; // SRTO_CRYPTOMODE

    int64_t llInputBW;         // Input stream rate (bytes/sec). 0: use internally estimated input bandwidth
    int64_t llMinInputBW;      // Minimum input stream rate estimate (bytes/sec)
    int  iOverheadBW;          // Percent above input stream rate (applies if llMaxBW == 0)
    bool bRcvNakReport;        // Enable Receiver Periodic NAK Reports
    int  iMaxReorderTolerance; //< Maximum allowed value for dynamic reorder tolerance

    // For the use of CCryptoControl
    // HaiCrypt configuration
    unsigned int uKmRefreshRatePkt;
    unsigned int uKmPreAnnouncePkt;

    uint32_t uSrtVersion;
    uint32_t uMinimumPeerSrtVersion;

    StringStorage<MAX_CONG_LENGTH>    sCongestion;
    StringStorage<MAX_PFILTER_LENGTH> sPacketFilterConfig;
    StringStorage<MAX_SID_LENGTH>     sStreamName;

    // Shortcuts and utilities
    int32_t flightCapacity()
    {
        return std::min(iRcvBufSize, iFlightFlagSize);
    }

    CSrtConfig()
        : iMSS(DEF_MSS)
        , zExpPayloadSize(SRT_LIVE_DEF_PLSIZE)
        , bSynSending(true)
        , bSynRecving(true)
        , iFlightFlagSize(DEF_FLIGHT_SIZE)
        , iSndBufSize(DEF_BUFFER_SIZE)
        , iRcvBufSize(DEF_BUFFER_SIZE)
        , bRendezvous(false)
        , tdConnTimeOut(srt::sync::seconds_from(DEF_CONNTIMEO_S))
        , bDriftTracer(true)
        , iSndTimeOut(-1)
        , iRcvTimeOut(-1)
        , llMaxBW(-1)
#ifdef ENABLE_MAXREXMITBW
        , llMaxRexmitBW(-1)
#endif
        , bDataSender(false)
        , bMessageAPI(true)
        , bTSBPD(true)
        , iRcvLatency(SRT_LIVE_DEF_LATENCY_MS)
        , iPeerLatency(0)
        , bTLPktDrop(true)
        , iSndDropDelay(0)
        , bEnforcedEnc(true)
        , iGroupConnect(0)
        , iPeerIdleTimeout_ms(COMM_RESPONSE_TIMEOUT_MS)
        , uMinStabilityTimeout_ms(COMM_DEF_MIN_STABILITY_TIMEOUT_MS)
        , iRetransmitAlgo(1)
        , iCryptoMode(CIPHER_MODE_AUTO)
        , llInputBW(0)
        , llMinInputBW(0)
        , iOverheadBW(25)
        , bRcvNakReport(true)
        , iMaxReorderTolerance(0) // Sensible optimal value is 10, 0 preserves old behavior
        , uKmRefreshRatePkt(0)
        , uKmPreAnnouncePkt(0)
        , uSrtVersion(SRT_DEF_VERSION)
        , uMinimumPeerSrtVersion(SRT_VERSION_MAJ1)

    {
        // Default UDT configurations
        iUDPRcvBufSize = iRcvBufSize * iMSS;

        // Linger: LIVE mode defaults, please refer to `SRTO_TRANSTYPE` option
        // for other modes.
        Linger.l_onoff   = 0;
        Linger.l_linger  = 0;
        CryptoSecret.len = 0;
        iSndCryptoKeyLen = 0;

        // Default congestion is "live".
        // Available builtin congestions: "file".
        // Others can be registerred.
        sCongestion.set("live", 4);
    }

    ~CSrtConfig()
    {
        // Wipeout critical data
        memset(&CryptoSecret, 0, sizeof(CryptoSecret));
    }

    int set(SRT_SOCKOPT optName, const void* val, int size);
};

template <typename T>
inline T cast_optval(const void* optval)
{
    return *reinterpret_cast<const T*>(optval);
}

template <typename T>
inline T cast_optval(const void* optval, int optlen)
{
    if (optlen > 0 && optlen != sizeof(T))
        throw CUDTException(MJ_NOTSUP, MN_INVAL, 0);

    return cast_optval<T>(optval);
}

// This function is to make it possible for both C and C++
// API to accept both bool and int types for boolean options.
// (it's not that C couldn't use <stdbool.h>, it's that people
// often forget to use correct type).
template <>
inline bool cast_optval(const void* optval, int optlen)
{
    if (optlen == sizeof(bool))
    {
        return *reinterpret_cast<const bool*>(optval);
    }

    if (optlen == sizeof(int))
    {
        // 0!= is a windows warning-killer int-to-bool conversion
        return 0 != *reinterpret_cast<const int*>(optval);
    }
    return false;
}

} // namespace srt

struct SRT_SocketOptionObject
{
    struct SingleOption
    {
        uint16_t      option;
        uint16_t      length;
        unsigned char storage[1]; // NOTE: Variable length object!
    };

    std::vector<SingleOption*> options;

    SRT_SocketOptionObject() {}

    ~SRT_SocketOptionObject()
    {
        for (size_t i = 0; i < options.size(); ++i)
        {
            // Convert back
            unsigned char* mem = reinterpret_cast<unsigned char*>(options[i]);
            delete[] mem;
        }
    }

    bool add(SRT_SOCKOPT optname, const void* optval, size_t optlen);
};

#endif