/* -*- Mode: C; tab-width: 4 -*-
*
* Copyright (c) 2002-2004 Apple Computer, Inc. All rights reserved.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include <stdio.h> // For printf()
#include <stdlib.h> // For exit() etc.
#include <string.h> // For strlen() etc.
#include <unistd.h> // For select()
#include <signal.h> // For SIGINT, SIGTERM
#include <errno.h> // For errno, EINTR
#include <netinet/in.h> // For INADDR_NONE
#include <arpa/inet.h> // For inet_addr()
#include <netdb.h> // For gethostbyname()
#include "mDNSEmbeddedAPI.h" // Defines the interface to the client layer above
#include "mDNSPosix.h" // Defines the specific types needed to run mDNS on this platform
#include "ExampleClientApp.h"
// Compatibility workaround: Solaris 2.5 has no INADDR_NONE
#ifndef INADDR_NONE
#define INADDR_NONE (mDNSu32)0xffffffff
#endif
//*************************************************************************************************************
// Globals
static mDNS mDNSStorage; // mDNS core uses this to store its globals
static mDNS_PlatformSupport PlatformStorage; // Stores this platform's globals
mDNSexport const char ProgramName[] = "mDNSProxyResponderPosix";
//*************************************************************************************************************
// Proxy Host Registration
typedef struct
{
mDNSv4Addr ip;
domainlabel hostlabel; // Conforms to standard DNS letter-digit-hyphen host name rules
AuthRecord RR_A; // 'A' (address) record for our ".local" name
AuthRecord RR_PTR; // PTR (reverse lookup) record
} ProxyHost;
mDNSlocal void HostNameCallback(mDNS *const m, AuthRecord *const rr, mStatus result)
{
ProxyHost *f = (ProxyHost*)rr->RecordContext;
if (result == mStatus_NoError)
debugf("Host name successfully registered: %##s", rr->resrec.name->c);
else
{
debugf("Host name conflict for %##s", rr->resrec.name->c);
mDNS_Deregister(m, &f->RR_A);
mDNS_Deregister(m, &f->RR_PTR);
exit(-1);
}
}
mDNSlocal mStatus mDNS_RegisterProxyHost(mDNS *m, ProxyHost *p)
{
char buffer[32];
mDNS_SetupResourceRecord(&p->RR_A, mDNSNULL, mDNSInterface_Any, kDNSType_A, 60, kDNSRecordTypeUnique, AuthRecordAny, HostNameCallback, p);
mDNS_SetupResourceRecord(&p->RR_PTR, mDNSNULL, mDNSInterface_Any, kDNSType_PTR, 60, kDNSRecordTypeKnownUnique, AuthRecordAny, HostNameCallback, p);
p->RR_A.namestorage.c[0] = 0;
AppendDomainLabel(&p->RR_A.namestorage, &p->hostlabel);
AppendLiteralLabelString(&p->RR_A.namestorage, "local");
// Note: This is reverse order compared to a normal dotted-decimal IP address, so we can't use our customary "%.4a" format code
mDNS_snprintf(buffer, sizeof(buffer), "%d.%d.%d.%d.in-addr.arpa.", p->ip.b[3], p->ip.b[2], p->ip.b[1], p->ip.b[0]);
MakeDomainNameFromDNSNameString(&p->RR_PTR.namestorage, buffer);
p->RR_PTR.ForceMCast = mDNStrue; // This PTR points to our dot-local name, so don't ever try to write it into a uDNS server
p->RR_A. resrec.rdata->u.ipv4 = p->ip;
AssignDomainName(&p->RR_PTR.resrec.rdata->u.name, p->RR_A.resrec.name);
mDNS_Register(m, &p->RR_A);
mDNS_Register(m, &p->RR_PTR);
debugf("Made Proxy Host Records for %##s", p->RR_A.resrec.name->c);
return(mStatus_NoError);
}
//*************************************************************************************************************
// Service Registration
// This sample ServiceCallback just calls mDNS_RenameAndReregisterService to automatically pick a new
// unique name for the service. For a device such as a printer, this may be appropriate.
// For a device with a user interface, and a screen, and a keyboard, the appropriate
// response may be to prompt the user and ask them to choose a new name for the service.
mDNSlocal void ServiceCallback(mDNS *const m, ServiceRecordSet *const sr, mStatus result)
{
switch (result)
{
case mStatus_NoError: debugf("Callback: %##s Name Registered", sr->RR_SRV.resrec.name->c); break;
case mStatus_NameConflict: debugf("Callback: %##s Name Conflict", sr->RR_SRV.resrec.name->c); break;
case mStatus_MemFree: debugf("Callback: %##s Memory Free", sr->RR_SRV.resrec.name->c); break;
default: debugf("Callback: %##s Unknown Result %ld", sr->RR_SRV.resrec.name->c, result); break;
}
if (result == mStatus_NoError)
{
char buffer[MAX_ESCAPED_DOMAIN_NAME];
ConvertDomainNameToCString(sr->RR_SRV.resrec.name, buffer);
printf("Service %s now registered and active\n", buffer);
}
if (result == mStatus_NameConflict)
{
char buffer1[MAX_ESCAPED_DOMAIN_NAME], buffer2[MAX_ESCAPED_DOMAIN_NAME];
ConvertDomainNameToCString(sr->RR_SRV.resrec.name, buffer1);
mDNS_RenameAndReregisterService(m, sr, mDNSNULL);
ConvertDomainNameToCString(sr->RR_SRV.resrec.name, buffer2);
printf("Name Conflict! %s renamed as %s\n", buffer1, buffer2);
}
}
// RegisterService() is a simple wrapper function which takes C string
// parameters, converts them to domainname parameters, and calls mDNS_RegisterService()
mDNSlocal void RegisterService(mDNS *m, ServiceRecordSet *recordset,
const char name[], const char type[], const char domain[],
const domainname *host, mDNSu16 PortAsNumber, int argc, char **argv)
{
domainlabel n;
domainname t, d;
unsigned char txtbuffer[1024], *bptr = txtbuffer;
char buffer[MAX_ESCAPED_DOMAIN_NAME];
MakeDomainLabelFromLiteralString(&n, name);
MakeDomainNameFromDNSNameString(&t, type);
MakeDomainNameFromDNSNameString(&d, domain);
while (argc)
{
int len = strlen(argv[0]);
if (len > 255 || bptr + 1 + len >= txtbuffer + sizeof(txtbuffer)) break;
printf("STR: %s\n", argv[0]);
bptr[0] = len;
strcpy((char*)(bptr+1), argv[0]);
bptr += 1 + len;
argc--;
argv++;
}
mDNS_RegisterService(m, recordset,
&n, &t, &d, // Name, type, domain
host, mDNSOpaque16fromIntVal(PortAsNumber),
txtbuffer, bptr-txtbuffer, // TXT data, length
mDNSNULL, 0, // Subtypes
mDNSInterface_Any, // Interface ID
ServiceCallback, mDNSNULL, 0); // Callback, context, flags
ConvertDomainNameToCString(recordset->RR_SRV.resrec.name, buffer);
printf("Made Service Records for %s\n", buffer);
}
//*************************************************************************************************************
// Service non-existence assertion
// (claiming a service name without actually providing a service at that name, to prevent anyone else using that name)
// This is useful to avoid confusion between similar services
// e.g. A printer that implements IPP printing service using the name "My Printer", but doesn't implement LPR service,
// should also claim the LPR service name "My Printer" to stop a different printer offering LPR service under the same name,
// since it would be confusing to users to have two equivalent services with the same name.
mDNSlocal void NoSuchServiceCallback(mDNS *const m, AuthRecord *const rr, mStatus result)
{
const domainname *proxyhostname = (const domainname *)rr->RecordContext;
switch (result)
{
case mStatus_NoError: debugf("Callback: %##s Name Registered", rr->resrec.name->c); break;
case mStatus_NameConflict: debugf("Callback: %##s Name Conflict", rr->resrec.name->c); break;
case mStatus_MemFree: debugf("Callback: %##s Memory Free", rr->resrec.name->c); break;
default: debugf("Callback: %##s Unknown Result %ld", rr->resrec.name->c, result); break;
}
if (result == mStatus_NoError)
{
char buffer[MAX_ESCAPED_DOMAIN_NAME];
ConvertDomainNameToCString(rr->resrec.name, buffer);
printf("Non-existence assertion %s now registered and active\n", buffer);
}
if (result == mStatus_NameConflict)
{
domainlabel n;
domainname t, d;
char buffer1[MAX_ESCAPED_DOMAIN_NAME], buffer2[MAX_ESCAPED_DOMAIN_NAME];
ConvertDomainNameToCString(rr->resrec.name, buffer1);
DeconstructServiceName(rr->resrec.name, &n, &t, &d);
IncrementLabelSuffix(&n, mDNStrue);
mDNS_RegisterNoSuchService(m, rr, &n, &t, &d, proxyhostname, mDNSInterface_Any, NoSuchServiceCallback, mDNSNULL, mDNSfalse);
ConvertDomainNameToCString(rr->resrec.name, buffer2);
printf("Name Conflict! %s renamed as %s\n", buffer1, buffer2);
}
}
mDNSlocal void RegisterNoSuchService(mDNS *m, AuthRecord *const rr, domainname *proxyhostname,
const char name[], const char type[], const char domain[])
{
domainlabel n;
domainname t, d;
char buffer[MAX_ESCAPED_DOMAIN_NAME];
MakeDomainLabelFromLiteralString(&n, name);
MakeDomainNameFromDNSNameString(&t, type);
MakeDomainNameFromDNSNameString(&d, domain);
mDNS_RegisterNoSuchService(m, rr, &n, &t, &d, proxyhostname, mDNSInterface_Any, NoSuchServiceCallback, proxyhostname, mDNSfalse);
ConvertDomainNameToCString(rr->resrec.name, buffer);
printf("Made Non-existence Record for %s\n", buffer);
}
//*************************************************************************************************************
// Main
mDNSexport int main(int argc, char **argv)
{
mStatus status;
sigset_t signals;
if (argc < 3) goto usage;
status = mDNS_Init(&mDNSStorage, &PlatformStorage,
mDNS_Init_NoCache, mDNS_Init_ZeroCacheSize,
mDNS_Init_DontAdvertiseLocalAddresses,
mDNS_Init_NoInitCallback, mDNS_Init_NoInitCallbackContext);
if (status) { fprintf(stderr, "Daemon start: mDNS_Init failed %d\n", (int)status); return(status); }
mDNSPosixListenForSignalInEventLoop(SIGINT);
mDNSPosixListenForSignalInEventLoop(SIGTERM);
if (!strcmp(argv[1], "-"))
{
domainname proxyhostname;
AuthRecord proxyrecord;
if (argc < 5) goto usage;
proxyhostname.c[0] = 0;
AppendLiteralLabelString(&proxyhostname, argv[2]);
AppendLiteralLabelString(&proxyhostname, "local");
RegisterNoSuchService(&mDNSStorage, &proxyrecord, &proxyhostname, argv[3], argv[4], "local.");
}
else
{
ProxyHost proxyhost;
ServiceRecordSet proxyservice;
proxyhost.ip.NotAnInteger = inet_addr(argv[1]);
if (proxyhost.ip.NotAnInteger == INADDR_NONE) // INADDR_NONE is 0xFFFFFFFF
{
struct hostent *h = gethostbyname(argv[1]);
if (h) proxyhost.ip.NotAnInteger = *(long*)h->h_addr;
}
if (proxyhost.ip.NotAnInteger == INADDR_NONE) // INADDR_NONE is 0xFFFFFFFF
{
fprintf(stderr, "%s is not valid host address\n", argv[1]);
return(-1);
}
MakeDomainLabelFromLiteralString(&proxyhost.hostlabel, argv[2]);
mDNS_RegisterProxyHost(&mDNSStorage, &proxyhost);
if (argc >=6)
RegisterService(&mDNSStorage, &proxyservice, argv[3], argv[4], "local.",
proxyhost.RR_A.resrec.name, atoi(argv[5]), argc-6, &argv[6]);
}
do
{
struct timeval timeout = { 0x3FFFFFFF, 0 }; // wait until SIGINT or SIGTERM
mDNSBool gotSomething;
mDNSPosixRunEventLoopOnce(&mDNSStorage, &timeout, &signals, &gotSomething);
}
while ( !( sigismember( &signals, SIGINT) || sigismember( &signals, SIGTERM)));
mDNS_Close(&mDNSStorage);
return(0);
usage:
fprintf(stderr, "%s ip hostlabel [srvname srvtype port txt [txt ...]]\n", argv[0]);
fprintf(stderr, "ip Real IP address (or valid host name) of the host where the service actually resides\n");
fprintf(stderr, "hostlabel First label of the dot-local host name to create for this host, e.g. \"foo\" for \"foo.local.\"\n");
fprintf(stderr, "srvname Descriptive name of service, e.g. \"Stuart's Ink Jet Printer\"\n");
fprintf(stderr, "srvtype IANA service type, e.g. \"_ipp._tcp\" or \"_ssh._tcp\", etc.\n");
fprintf(stderr, "port Port number where the service resides (1-65535)\n");
fprintf(stderr, "txt Additional name/value pairs specified in service definition, e.g. \"pdl=application/postscript\"\n");
fprintf(stderr, "e.g. %s 169.254.12.34 thehost (just create a dot-local host name)\n", argv[0]);
fprintf(stderr, "or %s 169.254.12.34 thehost \"My Printer\" _printer._tcp. 515 rp=lpt1 pdl=application/postscript\n", argv[0]);
fprintf(stderr, "or %s - thehost \"My Printer\" _printer._tcp. (assertion of non-existence)\n", argv[0]);
return(-1);
}