arduino Sip example

arduino sip esp.ino

/* ====================================================================

   Copyright (c) 2018 Juerge Liegner  All rights reserved.

   Redistribution and use in source and binary forms, with or without
   modification, are permitted provided that the following conditions
   are met:

   1. Redistributions of source code must retain the above copyright
      notice, this list of conditions and the following disclaimer.

   2. Redistributions in binary form must reproduce the above copyright
      notice, this list of conditions and the following disclaimer in
      the documentation and/or other materials provided with the
      distribution.

   3. Neither the name of the author(s) nor the names of any contributors
      may be used to endorse or promote products derived from this software
      without specific prior written permission.

   THIS SOFTWARE IS PROVIDED BY THE AUTHOR(S) AND CONTRIBUTORS "AS IS" AND
   ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR(S) OR CONTRIBUTORS BE LIABLE
   FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
   DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
   OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
   HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
   OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
   SUCH DAMAGE.

   ====================================================================*/

#include <ESP8266WiFi.h>
#include <WiFiUdp.h>
#define DEBUGLOG

//------------------------------------------------
// configuration with fix ip
//------------------------------------------------

// wlan param
const char* ssid        = "Hier eure SSID eintragen";
const char* password    = "Hier euer WLAN Passwort eintragen";

// sip params
const char *sipip       = "192.168.2.1"; // IP der FritzBox
int         sipport     = 5060;          // Port so lassen
const char *sipuser     = "Tuerklingel"; // Benutzername SIP-Call FritzBox
const char *sippasswd   = "SIP-Passwort";  // Passwort SIP-Call FritzBox

// dial params
const char *sipdialnr   = "**701";////unten auskomentiert
const char *sipdialtext = "Türklingel";////unten auskomentiert

// network params
const char *ip          = "192.168.2.69";   // Eigene IP vom ESP
const char *gw          = "192.168.2.1";    //Gateway
const char *mask        = "255.255.255.0";  //Subnetmask
const char *dns         = "192.168.2.1";    // DNS
//------------------------------------------------

//#define DEBUGLOG
WiFiUDP Udp;

/////////////////////////////////////////////////////////////////////////////////////////////////////
//
// hardware and api independent Sip class
//
/////////////////////////////////////////////////////////////////////////////////////////////////////

char set = 0;

class Sip
{
    char       *pbuf;
    size_t      lbuf;
    char        caRead[256];

    const char *pSipIp;
    int         iSipPort;
    const char *pSipUser;
    const char *pSipPassWd;
    const char *pMyIp;
    int         iMyPort;
    const char *pDialNr;
    const char *pDialDesc;

    uint32_t    callid;
    uint32_t    tagid;
    uint32_t    branchid;

    int         iAuthCnt;
    uint32_t    iRingTime;
    uint32_t    iMaxTime;
    int         iDialRetries;
    int         iLastCSeq;
    void        AddSipLine(const char* constFormat , ... );
    bool        AddCopySipLine(const char *p, const char *psearch);
    bool        ParseParameter(char *dest, int destlen, const char *name, const char *line, char cq = '\"');
    bool        ParseReturnParams(const char *p);
    int         GrepInteger(const char *p, const char *psearch);
    void        Ack(const char *pIn);
    void        Cancel(int seqn);
    void        Bye(int cseq);
    void        Ok(const char *pIn);
    void        Invite(const char *pIn = 0);

    uint32_t    Millis();
    uint32_t    Random();
    int         SendUdp();
    void        MakeMd5Digest(char *pOutHex33, char *pIn);

  public:
    Sip(char *pBuf, size_t lBuf);
    void        Init(const char *SipIp, int SipPort, const char *MyIp, int MyPort, const char *SipUser, const char *SipPassWd, int MaxDialSec = 10);
    void        HandleUdpPacket(const char *p);
    bool        Dial(const char *DialNr, const char *DialDesc = "");
    bool        IsBusy() {
      return iRingTime != 0;
    }
};

Sip::Sip(char *pBuf, size_t lBuf)
{
  pbuf = pBuf;
  lbuf = lBuf;
  pDialNr = "";
  pDialDesc = "";
}

bool Sip::Dial(const char *DialNr, const char *DialDesc)
{
  if (iRingTime)
    return false;

  iDialRetries = 0;
  pDialNr = DialNr;
  pDialDesc = DialDesc;
  Invite();
  iDialRetries++;
  iRingTime = Millis();
  return true;
}

void Sip::Cancel(int cseq)
{
  if (caRead[0] == 0)
    return;
  pbuf[0] = 0;
  AddSipLine("%s sip:%s@%s SIP/2.0",  "CANCEL", pDialNr, pSipIp);
  AddSipLine("%s",  caRead);
  AddSipLine("CSeq: %i %s",  cseq, "CANCEL");
  AddSipLine("Max-Forwards: 70");
  AddSipLine("User-Agent: sip-client/0.0.1");
  AddSipLine("Content-Length: 0");
  AddSipLine("");
  SendUdp();
}

void Sip::Bye(int cseq)
{
  if (caRead[0] == 0)
    return;
  pbuf[0] = 0;
  AddSipLine("%s sip:%s@%s SIP/2.0",  "BYE", pDialNr, pSipIp);
  AddSipLine("%s",  caRead);
  AddSipLine("CSeq: %i %s", cseq, "BYE");
  AddSipLine("Max-Forwards: 70");
  AddSipLine("User-Agent: sip-client/0.0.1");
  AddSipLine("Content-Length: 0");
  AddSipLine("");
  SendUdp();
}

void Sip::Ack(const char *p)
{
  char ca[32];
  bool b = ParseParameter(ca, (int)sizeof(ca), "To: <", p, '>');
  if (!b)
    return;

  pbuf[0] = 0;
  AddSipLine("ACK %s SIP/2.0", ca);
  AddCopySipLine(p, "Call-ID: ");
  int cseq = GrepInteger(p, "\nCSeq: ");
  AddSipLine("CSeq: %i ACK",  cseq);
  AddCopySipLine(p, "From: ");
  AddCopySipLine(p, "Via: ");
  AddCopySipLine(p, "To: ");
  AddSipLine("Content-Length: 0");
  AddSipLine("");
  SendUdp();
}

void Sip::Ok(const char *p)
{
  pbuf[0] = 0;
  AddSipLine("SIP/2.0 200 OK");
  AddCopySipLine(p, "Call-ID: ");
  AddCopySipLine(p, "CSeq: ");
  AddCopySipLine(p, "From: ");
  AddCopySipLine(p, "Via: ");
  AddCopySipLine(p, "To: ");
  AddSipLine("Content-Length: 0");
  AddSipLine("");
  SendUdp();
}

void Sip::Init(const char *SipIp, int SipPort, const char *MyIp, int MyPort, const char *SipUser, const char *SipPassWd, int MaxDialSec)
{
  caRead[0] = 0;
  pbuf[0] = 0;
  pSipIp = SipIp;
  iSipPort = SipPort;
  pSipUser = SipUser;
  pSipPassWd = SipPassWd;
  pMyIp = MyIp;
  iMyPort = MyPort;
  iAuthCnt = 0;
  iRingTime = 0;
  iMaxTime = MaxDialSec * 1000;
}

void Sip::AddSipLine(const char* constFormat , ... )
{
  va_list arglist;
  va_start( arglist, constFormat);
  uint16_t l = (uint16_t)strlen(pbuf);
  char *p = pbuf + l;
  vsnprintf(p, lbuf - l, constFormat, arglist );
  va_end( arglist );
  l = (uint16_t)strlen(pbuf);
  if (l < (lbuf - 2))
  {
    pbuf[l] = '\r';
    pbuf[l + 1] = '\n';
    pbuf[l + 2] = 0;
  }
}

// call invite without or with the response from peer
void Sip::Invite(const char *p)
{
  // prevent loops
  if (p && iAuthCnt > 3)
    return;

  // using caRead for temp. store realm and nonce
  char *caRealm = caRead;
  char *caNonce = caRead + 128;

  char *haResp = 0;
  int   cseq = 1;
  if (!p)
  {
    iAuthCnt = 0;
    if (iDialRetries == 0)
    {
      callid = Random();
      tagid = Random();
      branchid = Random();
    }
  }
  else
  {
    cseq = 2;
    if (   ParseParameter(caRealm, 128, " realm=\"", p)
           && ParseParameter(caNonce, 128, " nonce=\"", p))
    {
      // using output buffer to build the md5 hashes
      // store the md5 haResp to end of buffer
      char *ha1Hex = pbuf;
      char *ha2Hex = pbuf + 33;
      haResp = pbuf + lbuf - 34;
      char *pTemp = pbuf + 66;

      snprintf(pTemp, lbuf - 100, "%s:%s:%s", pSipUser, caRealm, pSipPassWd);
      MakeMd5Digest(ha1Hex, pTemp);

      snprintf(pTemp, lbuf - 100, "INVITE:sip:%s@%s", pDialNr, pSipIp);
      MakeMd5Digest(ha2Hex, pTemp);

      snprintf(pTemp, lbuf - 100, "%s:%s:%s", ha1Hex, caNonce, ha2Hex);
      MakeMd5Digest(haResp, pTemp);
    }
    else
    {
      caRead[0] = 0;
      return;
    }
  }
  pbuf[0] = 0;
  AddSipLine("INVITE sip:%s@%s SIP/2.0", pDialNr, pSipIp);
  AddSipLine("Call-ID: %010u@%s",  callid, pMyIp);
  AddSipLine("CSeq: %i INVITE",  cseq);
  AddSipLine("Max-Forwards: 70");
  // not needed for fritzbox
  // AddSipLine("User-Agent: sipdial by jl");
  AddSipLine("From: \"%s\"  <sip:%s@%s>;tag=%010u", pDialDesc, pSipUser, pSipIp, tagid);
  AddSipLine("Via: SIP/2.0/UDP %s:%i;branch=%010u;rport=%i", pMyIp, iMyPort, branchid, iMyPort);
  AddSipLine("To: <sip:%s@%s>", pDialNr, pSipIp);
  AddSipLine("Contact: \"%s\" <sip:%s@%s:%i;transport=udp>", pSipUser, pSipUser, pMyIp, iMyPort);
  if (p)
  {
    // authentication
    AddSipLine("Authorization: Digest username=\"%s\", realm=\"%s\", nonce=\"%s\", uri=\"sip:%s@%s\", response=\"%s\"", pSipUser, caRealm, caNonce, pDialNr, pSipIp, haResp);
    iAuthCnt++;
  }
  AddSipLine("Content-Type: application/sdp");
  // not needed for fritzbox
  // AddSipLine("Allow: INVITE, ACK, CANCEL, OPTIONS, BYE, REFER, NOTIFY, MESSAGE, SUBSCRIBE, INFO");
  AddSipLine("Content-Length: 0");
  AddSipLine("");
  caRead[0] = 0;
  SendUdp();
}

// parse parameter value from http formated string
bool Sip::ParseParameter(char *dest, int destlen, const char *name, const char *line, char cq)
{
  const char *qp;
  const char *r;
  if ((r = strstr(line, name)) != NULL)
  {
    r = r + strlen(name);
    qp = strchr(r, cq);
    int l = qp - r;
    if (l < destlen)
    {
      strncpy(dest, r, l);
      dest[l] = 0;
      return true;
    }
  }
  return false;
}

// search a line in response date (p) and append on
// pbuf
bool Sip::AddCopySipLine(const char *p, const char *psearch)
{
  char *pa = strstr((char*)p, psearch);
  if (pa)
  {
    char *pe = strstr(pa, "\r");
    if (pe == 0)
      pe = strstr(pa, "\n");
    if (pe > pa)
    {
      char c = *pe;
      *pe = 0;
      AddSipLine("%s", pa);
      *pe = c;
      return true;
    }
  }
  return false;
}

int Sip::GrepInteger(const char *p, const char *psearch)
{
  int param = -1;
  const char *pc = strstr(p, psearch);
  if (pc)
  {
    param = atoi(pc + strlen(psearch));
  }
  return param;
}

// copy Call-ID, From, Via and To from response
// to caRead
// using later for BYE or CANCEL the call
bool Sip::ParseReturnParams(const char *p)
{
  pbuf[0] = 0;
  AddCopySipLine(p, "Call-ID: ");
  AddCopySipLine(p, "From: ");
  AddCopySipLine(p, "Via: ");
  AddCopySipLine(p, "To: ");
  if (strlen(pbuf) >= 2)
  {
    strcpy(caRead, pbuf);
    caRead[strlen(caRead) - 2] = 0;
  }
  return true;
}

void Sip::HandleUdpPacket(const char *p)
{
  uint32_t iWorkTime = iRingTime ? (Millis() - iRingTime) : 0;
  if (iRingTime && iWorkTime > iMaxTime)
  {
    // Cancel(3);
    Bye(3);
    iRingTime = 0;
  }

  if (!p)
  {
    // max 5 dial retry when loos first invite packet
    if (iAuthCnt == 0 && iDialRetries < 5 && iWorkTime > (iDialRetries * 200))
    {
      iDialRetries++;
      delay(30);
      Invite();
    }
    return;
  }

  if (strstr(p, "SIP/2.0 401 Unauthorized") == p)
  {
    Ack(p);
    // call Invite with response data (p) to build auth md5 hashes
    Invite(p);
  }
  else if (strstr(p, "BYE") == p)
  {
    Ok(p);
    iRingTime = 0;
  }
  else if (strstr(p, "SIP/2.0 200") == p)    // OK
  {
    ParseReturnParams(p);
    Ack(p);
  }
  else if (   strstr(p, "SIP/2.0 183 ") == p // Session Progress
              || strstr(p, "SIP/2.0 180 ") == p ) // Ringing
  {
    ParseReturnParams(p);
  }
  else if (strstr(p, "SIP/2.0 100 ") == p)   // Trying
  {
    ParseReturnParams(p);
    Ack(p);
  }
  else if (   strstr(p, "SIP/2.0 486 ") == p // Busy Here
              || strstr(p, "SIP/2.0 603 ") == p // Decline
              || strstr(p, "SIP/2.0 487 ") == p) // Request Terminatet
  {
    Ack(p);
    iRingTime = 0;
  }
  else if (strstr(p, "INFO") == p)
  {
    iLastCSeq = GrepInteger(p, "\nCSeq: ");
    Ok(p);
  }
}

/////////////////////////////////////////////////////////////////////////////////////////////////////
//
// hardware dependent interface functions
//
/////////////////////////////////////////////////////////////////////////////////////////////////////

int Sip::SendUdp()
{
  Udp.beginPacket(pSipIp, iSipPort);
  Udp.write(pbuf, strlen(pbuf));
  Udp.endPacket();
  return 0;
}

// generate a 30 bit random number
uint32_t Sip::Random()
{
  // return ((((uint32_t)rand())&0x7fff)<<15) + ((((uint32_t)rand())&0x7fff));
  return secureRandom(0x3fffffff);
}

uint32_t Sip::Millis()
{
  return (uint32_t)millis() + 1;
}

void Sip::MakeMd5Digest(char *pOutHex33, char *pIn)
{
  MD5Builder aMd5;
  aMd5.begin();
  aMd5.add(pIn);
  aMd5.calculate();
  aMd5.getChars(pOutHex33);
}

/////////////////////////////////////////////////////////////////////////////////////////////////////
//
// Arduino setup() and loop()
//
/////////////////////////////////////////////////////////////////////////////////////////////////////

char caSipIn[2048];
char caSipOut[2048];
Sip aSip(caSipOut, sizeof(caSipOut));

void setup()
{
  WiFi.softAPdisconnect (true);
  pinMode(12, INPUT_PULLUP);
  pinMode(13, INPUT_PULLUP);

  IPAddress Ip;
  IPAddress Gw;
  IPAddress Mask;
  IPAddress Dns;

  Ip.fromString(ip);
  Gw.fromString(gw);
  Mask.fromString(mask);
  Dns.fromString(dns);

  WiFi.config(Ip, Gw, Mask, Dns);

  if (String(ssid) != WiFi.SSID())
  {
    WiFi.begin(ssid, password);
  }
  // Verbindung zum router Herstellen
  int i = 0;
  for (i = 0; i < 100; i++)
  {
    if (WiFi.status() == WL_CONNECTED)
      break;
    delay(100);
  }

  if (i >= 100)
  {
    // without connection go to sleep
    delay(1000);
  }

  WiFi.persistent(true);
  Udp.begin(sipport);
  aSip.Init(sipip, sipport, ip, sipport, sipuser, sippasswd, 15);
  //aSip.Dial(sipdialnr, sipdialtext);
}
int deepSleepDelay = 0;

void loop(void)
{
  int packetSize = Udp.parsePacket();
  if (packetSize > 0)
  {
    caSipIn[0] = 0;
    packetSize = Udp.read(caSipIn, sizeof(caSipIn));
    if (packetSize > 0)
    {
      caSipIn[packetSize] = 0;
    }
  }
  aSip.HandleUdpPacket((packetSize > 0) ? caSipIn : 0 );
  if (!aSip.IsBusy() && deepSleepDelay == 0)
    deepSleepDelay = millis();
  if (deepSleepDelay && (millis() - deepSleepDelay) > 500)
  {}

  // Ab Hier ist euer Programm


  // GPIO 13 auf minus gezogen wird
  if (digitalRead(13) == LOW) {
    //aSip.Dial("**9", "GPIO D7 !");
    aSip.Dial("**9", "Klingel oben");
  }

  if (digitalRead(12) == LOW) {
    //aSip.Dial("**9", "GPIO D6 !");
    aSip.Dial("**9", "Klingel unten");
  }



}