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cwMdns.cpp : Initial working version with TCP connection.

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This commit is contained in:
kpl 2020-01-29 11:43:53 -05:00
parent 6978f53626
commit 01045493ba
1 changed files with 389 additions and 41 deletions
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430
cwMdns.cpp
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@ -66,7 +66,9 @@ namespace cw
typedef struct mdns_app_str
{
srv::handle_t mdnsH;
srv::handle_t tcpH;
socket::handle_t tcpH;
thread::handle_t tcpThreadH;
unsigned recvBufByteN;
unsigned cbN;
mdns_t mdns;
} mdns_app_t;
@ -117,6 +119,7 @@ namespace cw
kAAAA_DnsTId = 28,
kSRV_DnsTId = 33,
kOPT_DnsTId = 41,
kNSEC_DnsTId = 47,
kANY_DnsTId = 255
// REMEMBER: Add new type id's to dnsTypeIdToString()
};
@ -149,6 +152,7 @@ namespace cw
case kAAAA_DnsTId: return "AAAA";
case kSRV_DnsTId: return "SRV";
case kOPT_DnsTId: return "OPT";
case kNSEC_DnsTId: return "NSEC";
case kANY_DnsTId: return "ANY";
}
return "<unknown DNS type>";
@ -173,7 +177,10 @@ namespace cw
// unsigned n0 = msgByteN;
// record name bytes
msgByteN += strlen(name) + 2; // add 1 for initial segment length and 1 for terminating zero
if( name[0] == ((char)0xc0) )
msgByteN += 2;
else
msgByteN += strlen(name) + 2; // add 1 for initial segment length and 1 for terminating zero
if( recdTId == kQuestionRecdTId )
{
@ -186,10 +193,38 @@ namespace cw
switch( dnsTId )
{
case kA_DnsTId: msgByteN += kABodyByteN; break;
case kPTR_DnsTId: msgByteN += strlen(text) + 1; break;
case kTXT_DnsTId: msgByteN += strlen(text) + 1; break;
case kSRV_DnsTId: msgByteN += kSrvBodyByteN + strlen(text) + 1; break;
case kA_DnsTId:
msgByteN += kABodyByteN;
break;
case kPTR_DnsTId:
if( numb0 == 0 )
{
if( text[0] == ((char)0xc0) )
msgByteN += 2;
else
msgByteN += strlen(text) + 1;
}
else
{
msgByteN += 2;
}
break;
case kTXT_DnsTId:
if( text[0] == ((char)0xc0) )
msgByteN += 2;
else
msgByteN += strlen(text) + 2;
break;
case kSRV_DnsTId:
msgByteN += kSrvBodyByteN;
if( text[0] == ((char)0xc0) )
msgByteN += 2;
else
msgByteN += strlen(text) + 1;
break;
default:
assert(0);
}
@ -221,6 +256,14 @@ namespace cw
unsigned n = 0;
unsigned j = 0;
if( name[0] == ((char)0xc0) )
{
assert( bN >= 2 );
b[0] = name[0];
b[1] = name[1];
return b + 1 + 1;
}
// for each input character
for(unsigned i=0; true; ++i)
{
@ -282,20 +325,37 @@ namespace cw
{
char* b1 = format_rsrc( b, bN, name, kA_DnsTId, clss, ttl, kABodyByteN );
uint32_t* l = (uint32_t*)b1;
l[0] = htonl(addr);
l[0] = addr; //htonl(addr);
return b1 + kABodyByteN;
}
char* format_PTR_rsrc( char* b, unsigned bN, const char* name, unsigned clss, unsigned ttl, const char* text )
char* format_PTR_rsrc( char* b, unsigned bN, const char* name, unsigned clss, unsigned ttl, const char* text, unsigned offset=0 )
{
// u[0] u[1] u[2-3] u[4] u[5 ... ]
// type class TTL dlen text
unsigned dataByteN = strlen(text)+1;
if( offset != 0 || text[0] == ((char)0xc0) )
dataByteN = 2;
char* b1 = format_rsrc( b, bN, name, kPTR_DnsTId, clss, ttl, dataByteN );
b1 = format_name(b1,bN-(b1-b),text,false);
assert( b < b1 );
unsigned n = b1-b;
if( offset == 0 )
{
b1 = format_name(b1,bN-n,text,false);
}
else
{
assert( bN - n >= 2 );
b1[0] = ((char)0xc0);
b1[1] = offset;
b1 += dataByteN;
}
return b1;
}
@ -306,7 +366,7 @@ namespace cw
unsigned dataByteN = strlen(text)+1;
char* b1 = format_rsrc( b, bN, name, kTXT_DnsTId, clss, ttl, dataByteN );
b1 = format_name(b1,bN-(b1-b),text,false,'\n');
return b1;
}
@ -315,14 +375,20 @@ namespace cw
{
// u[0] u[1] u[2-3] u[4] u[5] u[6] u[7] u[8 ...]
// type class TTL dlen pri weight port target
unsigned dataByteN = kSrvBodyByteN;
unsigned dataByteN = kSrvBodyByteN + strlen(text)+1;
char* b1 = format_rsrc( b, bN, name, kSRV_DnsTId, clss, ttl, dataByteN );
if( text[0] == ((char)0xc0))
dataByteN = 2;
else
dataByteN += strlen(text)+1;
char* b1 = format_rsrc( b, bN, name, kSRV_DnsTId, clss, ttl, dataByteN+1 );
uint16_t* u = (uint16_t*)b1;
u[0] = htons(priority);
u[1] = htons(weight);
u[2] = htons(port);
b1 = format_name(b1 + kSrvBodyByteN,bN-((b1-b)+kSrvBodyByteN),text,false);
b1 = format_name(b1 + kSrvBodyByteN,bN-((b1-b)+kSrvBodyByteN),text,true);
return b1;
}
@ -355,8 +421,6 @@ namespace cw
uint16_t* u = (uint16_t*)buf;
unsigned recdN = 0;
u[0] = transactionId;
u[1] = flags;
// for each specified record
while( true )
@ -381,7 +445,7 @@ namespace cw
switch( dnsTId )
{
case kA_DnsTId: b1 = format_A_rsrc( b0, bN, name, clss, ttl, numb0 ); break;
case kPTR_DnsTId: b1 = format_PTR_rsrc(b0, bN, name, clss, ttl, text ); break;
case kPTR_DnsTId: b1 = format_PTR_rsrc(b0, bN, name, clss, ttl, text, numb0 ); break;
case kTXT_DnsTId: b1 = format_TXT_rsrc(b0, bN, name, clss, ttl, text ); break;
case kSRV_DnsTId: b1 = format_SRV_rsrc(b0, bN, name, clss, ttl, text, numb0 ); break;
default:
@ -423,6 +487,8 @@ namespace cw
*msgByteNRef = byteN;
// convert the record counts to the network endianess
u[0] = htons(transactionId);
u[1] = htons(flags);
u[2] = htons(u[2]);
u[3] = htons(u[3]);
u[4] = htons(u[4]);
@ -452,7 +518,7 @@ namespace cw
return b;
}
unsigned calc_ptr_string_byte_count( const char* b )
unsigned calc_ptr_string_byte_count( const char* b, bool dotFl )
{
unsigned n = 0;
unsigned i = 0;
@ -461,8 +527,9 @@ namespace cw
while( b[i] != 0 && (b[i] & 0xc0) != 0xc0)
{
// TODO: what if this is a 'ptr' ... getting the length of a pointer string may require a recursive function?
n += b[i] + 1;
n += b[i] + (dotFl ? 1 : 0);
i += b[i] + 1;
dotFl = true;
}
return n;
}
@ -489,10 +556,10 @@ namespace cw
unsigned short offset = b[i] & 0x3f;
offset = (offset<<8) + ((unsigned char)b[i+1]);
strByteN += calc_ptr_string_byte_count( base + offset) + 1;
strByteN += calc_ptr_string_byte_count( base + offset, i!=0) + 1;
if( logFl )
log(p,"%.*s | ", base[offset], base + offset + 1 );
log(p,"%.*s.", base[offset], base + offset + 1 );
i += 2;
@ -505,13 +572,14 @@ namespace cw
if( b[i] == 0 )
{
++i;
strByteN += 1;
break; // zero terminates the name
}
if( logFl )
log(p,"%.*s | ", b[i], b+i+1 );
log(p,"%.*s.", b[i], b+i+1 );
strByteN += b[i] + 1;
strByteN += b[i] + (i==0 ? 0 : 1);
i += b[i] + 1;
segN += 1;
@ -531,11 +599,98 @@ namespace cw
return i; // i is the count of byte used by the name in the packet buffer
}
// name[0] must be the length of the segment.
// Returns the count of bytes written to buf.
unsigned copy_out_segment( const char* name, char* buf, unsigned bufN, bool dotFl )
{
// get segment length
unsigned n = name[0];
unsigned i = 0;
if( dotFl )
{
assert( bufN > 0 );
buf[0] = '.';
i += 1;
bufN -= 1;
}
assert( n <= bufN );
strncpy(buf + i, name+1, n );
return i + n;
}
// Return the count of bytes written to buf[].
unsigned get_ptr_name( const char* name, char* buf, unsigned bufByteN, bool dotFl )
{
unsigned i = 0;
unsigned N = 0;
// terminate when a zero or another ptr string is encountered
while( name[i] != 0 && (name[i] & 0xc0) != 0xc0)
{
unsigned n = copy_out_segment( name + i, buf, bufByteN, dotFl );
buf += n;
bufByteN -= n;
dotFl = true;
i += name[i] + 1;
N += n;
}
return N;
}
void get_name( const char* b, const char* base, char* buf, unsigned bufByteN )
{
unsigned i = 0;
while( true )
{
// if this a pointer
if( (b[i] & 0xc0) == 0xc0 )
{
// TODO check for going past buffer before add 1 to index
unsigned short offset = b[i] & 0x3f;
offset = (offset<<8) + ((unsigned char)b[i+1]);
unsigned n = get_ptr_name( base + offset, buf, bufByteN, i!=0 );
bufByteN -= n;
buf += n;
i += 2;
break; // ptr terminates the name
}
else
{
if( b[i] == 0 )
{
break; // zero terminates the name
}
unsigned n = copy_out_segment( b + i, buf, bufByteN, i!=0 );
bufByteN -= n;
buf += n;
i += b[i] + 1;
}
}
assert( bufByteN >= 1 );
buf[0] = 0;
bufByteN -= 1;
}
unsigned resource_recd_byte_count( mdns_t* p, const char* base, const char* b, unsigned bN )
{
unsigned nameN = calc_name_byte_count( p, base, b, bN, nullptr, false );
uint16_t* u = (uint16_t*)(b + nameN);
return nameN + 10 + ntohs(u[4]);
}
@ -577,7 +732,7 @@ namespace cw
const char* target = b + kSrvBodyByteN;
unsigned nameN = calc_name_byte_count( p, base, target, byteN - kSrvBodyByteN );
return b + kSrvBodyByteN + nameN;
return b + kSrvBodyByteN + nameN + 1;
}
const char* parse_OPT_recd( mdns_t* p, const char* base, const char* b, unsigned byteN )
@ -591,9 +746,16 @@ namespace cw
return b + kOptBodyByteN + optByteN;
}
const char* parse_NSEC_recd( mdns_t* p, const char* base, const char* b, unsigned byteN )
{
// TODO: add parser here
return nullptr;
}
const char* parse_resource_recd( mdns_t* p, const char* base, const char* b, unsigned byteN )
{
unsigned nameByteN = calc_name_byte_count( p, base, b, byteN-kRsrcBodyByteN );
unsigned nameStrByteN = 0;
unsigned nameByteN = calc_name_byte_count( p, base, b, byteN-kRsrcBodyByteN, &nameStrByteN );
uint16_t* u = (uint16_t*)(b + nameByteN);
uint16_t type = ntohs(u[0]);
uint16_t clss = ntohs(u[1]);
@ -603,6 +765,9 @@ namespace cw
log(p," nameN:%i type:%s (0x%02x) class:0x%02x ttl:%i dataN:%i ",nameByteN,dnsTypeIdToString(type),type,clss,ttl,dataN );
char nameBuf[ nameStrByteN ];
get_name( b, base, nameBuf, nameStrByteN );
b += nameByteN + kRsrcBodyByteN; // advance to the record data
assert( nameByteN + kRsrcBodyByteN + dataN <= byteN);
@ -614,11 +779,14 @@ namespace cw
case kTXT_DnsTId: parse_TXT_recd(p,base,b,dataN); break;
case kSRV_DnsTId: parse_SRV_recd(p,base,b,dataN); break;
case kOPT_DnsTId: parse_OPT_recd(p,base,b,dataN); break;
case kNSEC_DnsTId: parse_NSEC_recd(p,base,b,dataN); break;
default:
error(p,"Unhandled DNS type id: %i (0x%x)",type);
}
log(p,"\n");
printf("Extracted name:%s\n",nameBuf);
return b0 + resource_recd_byte_count(p,base,b0,byteN);
@ -691,7 +859,6 @@ namespace cw
uint16_t nameSrvN = ntohs(hdr[4]);
uint16_t addN = ntohs(hdr[5]);
log(p,"*** Msg: id:0x%04x flags:0x%04x qN:%i aN:%i nsN:%i addN:%i\n", transId, flags, questionN, answerN, nameSrvN,addN);
const char* b0 = (const char*)(hdr + 6);
@ -752,15 +919,155 @@ namespace cw
}
}
void mdnsRecieveCallback( void* arg, const void* data, unsigned dataByteCnt, const struct sockaddr_in* fromAddr )
void udpReceiveCallback( void* arg, const void* data, unsigned dataByteCnt, const struct sockaddr_in* fromAddr )
{
mdns_app_t* p = static_cast<mdns_app_t*>(arg);
char addrBuf[ INET_ADDRSTRLEN ];
socket::addrToString( fromAddr, addrBuf, INET_ADDRSTRLEN );
p->cbN += 1;
printf("%i bytes:%i %s\n", p->cbN, dataByteCnt, addrBuf );
print_hex( (const char*)data, dataByteCnt );
parse_msg(&p->mdns,data,dataByteCnt);
if( true )
{
printf("%i bytes:%i %s\n", p->cbN, dataByteCnt, addrBuf );
print_hex( (const char*)data, dataByteCnt );
parse_msg(&p->mdns,data,dataByteCnt);
}
}
bool tcpReceiveCallback( void* arg )
{
mdns_app_t* p = static_cast<mdns_app_t*>(arg);
socket::handle_t sockH = p->tcpH;
char buf[ p->recvBufByteN ];
unsigned readByteN = 0;
rc_t rc = kOkRC;
if( !socket::isConnected(sockH) )
{
if((rc = socket::accept( sockH )) == kOkRC )
{
log(&p->mdns,"TCP connected.\n");
}
}
else
{
if((rc = socket::recieve( sockH, buf, p->recvBufByteN, &readByteN, nullptr )) == kOkRC )
{
// if the server disconnects then recvBufByteN
if( isConnected( sockH ) )
{
log(&p->mdns,"TCP disconnected.");
}
else
{
printf("+");
fflush(stdout);
// handle recv'd TCP messages here.
}
}
}
return true;
}
rc_t sendMsg1( mdns_app_t* p )
{
rc_t rc = kOkRC;
unsigned transId = 0;
unsigned bufByteN = 0;
unsigned flags = 0;
unsigned ttl = 120;
socket::handle_t sockH = srv::socketHandle(p->mdnsH);
struct sockaddr_in addr;
if((rc = socket::initAddr( sockH, "192.168.0.68", 4325, &addr )) != kOkRC )
{
error(&p->mdns,"Get inet address failed.");
goto errLabel;
}
else
{
//const char* mac = "985AEB89BAAA"
char* buf = alloc_msg( &bufByteN, transId, flags,
kQuestionRecdTId, "68.0.168.192.in-addr.arpa", kANY_DnsTId, kInClassFl, 0, 0, nullptr,
kQuestionRecdTId, "Euphonix-MC-985AEB89BAAA.local", kANY_DnsTId, kInClassFl, 0, 0, nullptr,
kNameServerRecdTId, "Euphonix-MC-985AEB89BAAA.local", kA_DnsTId, kInClassFl, ttl, addr.sin_addr, nullptr,
kNameServerRecdTId, "68.0.168.192.in-addr.arpa", kPTR_DnsTId, kInClassFl, ttl, 43, "Euphonix-MC-985AEB89BAAA.local",
kInvalidRecdTId );
//print_hex(buf,bufByteN);
//parse_msg( nullptr, buf, bufByteN );
send( sockH, buf, bufByteN, "224.0.0.251", 5353 );
free(buf);
}
errLabel:
return rc;
}
rc_t sendMsg2( mdns_app_t* p )
{
rc_t rc = kOkRC;
unsigned transId = 0;
unsigned bufByteN = 0;
unsigned flags = 0x8400;
socket::handle_t sockH = srv::socketHandle(p->mdnsH);
struct sockaddr_in addr;
if((rc = socket::initAddr( sockH, "192.168.0.68", 4325, &addr )) != kOkRC )
{
error(&p->mdns,"Get inet address failed.");
goto errLabel;
}
else
{
char* buf0 = alloc_msg( &bufByteN, transId, 0,
kQuestionRecdTId, "MC Mix - 1._EuConProxy._tcp.local", kANY_DnsTId, kInClassFl, 0, 0, nullptr,
kNameServerRecdTId, "\xc0\x0c", kSRV_DnsTId, kInClassFl, 120, 49168, "Euphonix-MC-985AEB89BAAA.local",
kNameServerRecdTId, "\xc0\x0c", kTXT_DnsTId, kInClassFl, 4500, 0, "lmac=98-5A-EB-89-BA-AA\ndummy=0",
kInvalidRecdTId );
//print_hex(buf0,bufByteN);
//send( sockH, buf0, bufByteN, "224.0.0.251", 5353 );
free(buf0);
bufByteN = 0;
char* buf = alloc_msg( &bufByteN, transId, flags,
kAnswerRecdTId, "MC Mix - 1._EuConProxy._tcp.local", kSRV_DnsTId, kFlushClassFl | kInClassFl, 120, 49168, "Euphonix-MC-985AEB89BAAA.local",
kAnswerRecdTId, "\xc0\x3f", kA_DnsTId, kFlushClassFl | kInClassFl, 120, addr.sin_addr, nullptr,
kAnswerRecdTId, "\xc0\x17", kPTR_DnsTId, kInClassFl, 4500, 0, "\xc0\x0c",
kAnswerRecdTId, "\xc0\x0c", kTXT_DnsTId, kFlushClassFl | kInClassFl, 4500, 0, "lmac=98-5A-EB-89-BA-AA\ndummy=1",
kAnswerRecdTId, "_services._dns-sd._udp.local", kPTR_DnsTId, kInClassFl, 4500, 0, "\xc0\x17",
kInvalidRecdTId );
/* working with 1
char* buf = alloc_msg( &bufByteN, transId, flags,
kAnswerRecdTId, "MC Mix._EuConProxy._tcp.local", kSRV_DnsTId, kFlushClassFl | kInClassFl, 120, 49168, "Euphonix-MC-985AEB89BAAA.local",
kAnswerRecdTId, "\xc0\x3b", kA_DnsTId, kFlushClassFl | kInClassFl, 120, addr.sin_addr, nullptr,
kAnswerRecdTId, "\xc0\x13", kPTR_DnsTId, kInClassFl, 4500, 0, "\xc0\x0c",
kAnswerRecdTId, "\xc0\x0c", kTXT_DnsTId, kFlushClassFl | kInClassFl, 4500, 0, "lmac=98-5A-EB-89-BA-AA\ndummy=1",
kAnswerRecdTId, "_services._dns-sd._udp.local", kPTR_DnsTId, kInClassFl, 4500, 0, "\xc0\x13",
kInvalidRecdTId );
*/
//print_hex(buf,bufByteN);
//parse_msg( nullptr, buf, bufByteN );
send( sockH, buf, bufByteN, "224.0.0.251", 5353 );
free(buf);
}
errLabel:
return rc;
}
void testAllocMsg( const char* tag )
@ -798,8 +1105,7 @@ namespace cw
free(buf);
}
}
}
}
@ -810,36 +1116,66 @@ cw::rc_t cw::net::mdns::test()
{
rc_t rc;
socket::portNumber_t mdnsPort = 5353;
unsigned recvBufByteCnt = 4096;
unsigned timeOutMs = 0; // if timeOutMs==0 server uses recv_from()
socket::portNumber_t tcpPort = 49168;
unsigned udpTimeOutMs = 0; // if timeOutMs==0 server uses recv_from()
unsigned tcpTimeOutMs = 50;
const unsigned sbufN = 31;
char sbuf[ sbufN+1 ];
mdns_app_t app;
app.cbN = 0;
app.cbN = 0;
app.recvBufByteN = 4096;
// create the mDNS UDP socket server
if((rc = srv::create(
app.mdnsH,
mdnsPort,
socket::kNonBlockingFl | socket::kReuseAddrFl | socket::kReusePortFl | socket::kMultiCastTtlFl | socket::kMultiCastLoopFl,
mdnsRecieveCallback,
udpReceiveCallback,
&app,
recvBufByteCnt,
timeOutMs,
app.recvBufByteN,
udpTimeOutMs,
NULL,
socket::kInvalidPortNumber )) != kOkRC )
{
return rc;
{
return cwLogError(rc,"mDNS UDP socket create failed.");
}
// add the mDNS socket to the multicast group
if((rc = join_multicast_group( socketHandle(app.mdnsH), "224.0.0.251" )) != kOkRC )
goto errLabel;
// set the TTL for multicast
if((rc = set_multicast_time_to_live( socketHandle(app.mdnsH), 255 )) != kOkRC )
goto errLabel;
// create the mDNS TCP socket
if((rc = socket::create(
app.tcpH,
tcpPort,
socket::kTcpFl | socket::kBlockingFl | socket::kStreamFl | socket::kListenFl,
tcpTimeOutMs,
NULL,
socket::kInvalidPortNumber )) != kOkRC )
{
rc = cwLogError(rc,"mDNS TCP socket create failed.");
goto errLabel;
}
// create the TCP listening thread
if((rc = thread::create( app.tcpThreadH, tcpReceiveCallback, &app )) != kOkRC )
goto errLabel;
// start the mDNS socket server
if((rc = srv::start( app.mdnsH )) != kOkRC )
goto errLabel;
// start the tcp thread
if((rc = thread::unpause( app.tcpThreadH )) != kOkRC )
goto errLabel;
while( true )
{
printf("? ");
@ -850,6 +1186,16 @@ cw::rc_t cw::net::mdns::test()
testAllocMsg(sbuf);
break;
}
if( strcmp(sbuf,"msg1\n") == 0 )
{
sendMsg1( &app );
}
if( strcmp(sbuf,"msg2\n") == 0 )
{
sendMsg2( &app );
}
if( strcmp(sbuf,"quit\n") == 0)
break;
@ -859,6 +1205,8 @@ cw::rc_t cw::net::mdns::test()
errLabel:
// close the mDNS server
rc_t rc0 = destroy(app.mdnsH);
rc_t rc1 = thread::destroy(app.tcpThreadH);
rc_t rc2 = socket::destroy(app.tcpH);
return rcSelect(rc,rc0);
return rcSelect(rc,rc0,rc1,rc2);
}