/* -*- 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 <assert.h>
#include <signal.h>
#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include <stdlib.h>
#include "mDNSEmbeddedAPI.h" // Defines the interface to the mDNS core code
#include "mDNSPosix.h" // Defines the specific types needed to run mDNS on this platform
#include "ExampleClientApp.h"
// Globals
static mDNS mDNSStorage; // mDNS core uses this to store its globals
static mDNS_PlatformSupport PlatformStorage; // Stores this platform's globals
#define RR_CACHE_SIZE 500
static CacheEntity gRRCache[RR_CACHE_SIZE];
mDNSexport const char ProgramName[] = "mDNSClientPosix";
static const char *gProgramName = ProgramName;
static void BrowseCallback(mDNS *const m, DNSQuestion *question, const ResourceRecord *const answer, QC_result AddRecord)
// A callback from the core mDNS code that indicates that we've received a
// response to our query. Note that this code runs on the main thread
// (in fact, there is only one thread!), so we can safely printf the results.
{
domainlabel name;
domainname type;
domainname domain;
char nameC [MAX_DOMAIN_LABEL+1]; // Unescaped name: up to 63 bytes plus C-string terminating NULL.
char typeC [MAX_ESCAPED_DOMAIN_NAME];
char domainC[MAX_ESCAPED_DOMAIN_NAME];
const char *state;
(void)m; // Unused
(void)question; // Unused
assert(answer->rrtype == kDNSType_PTR);
DeconstructServiceName(&answer->rdata->u.name, &name, &type, &domain);
ConvertDomainLabelToCString_unescaped(&name, nameC);
ConvertDomainNameToCString(&type, typeC);
ConvertDomainNameToCString(&domain, domainC);
// If the TTL has hit 0, the service is no longer available.
if (!AddRecord) {
state = "Lost ";
} else {
state = "Found";
}
fprintf(stderr, "*** %s name = '%s', type = '%s', domain = '%s'\n", state, nameC, typeC, domainC);
}
static mDNSBool CheckThatServiceTypeIsUsable(const char *serviceType, mDNSBool printExplanation)
// Checks that serviceType is a reasonable service type
// label and, if it isn't and printExplanation is true, prints
// an explanation of why not.
{
mDNSBool result;
result = mDNStrue;
if (result && strlen(serviceType) > 63) {
if (printExplanation) {
fprintf(stderr,
"%s: Service type specified by -t is too long (must be 63 characters or less)\n",
gProgramName);
}
result = mDNSfalse;
}
if (result && serviceType[0] == 0) {
if (printExplanation) {
fprintf(stderr,
"%s: Service type specified by -t can't be empty\n",
gProgramName);
}
result = mDNSfalse;
}
return result;
}
static const char kDefaultServiceType[] = "_afpovertcp._tcp";
static const char kDefaultDomain[] = "local.";
static void PrintUsage()
{
fprintf(stderr,
"Usage: %s [-v level] [-t type] [-d domain]\n",
gProgramName);
fprintf(stderr, " -v verbose mode, level is a number from 0 to 2\n");
fprintf(stderr, " 0 = no debugging info (default)\n");
fprintf(stderr, " 1 = standard debugging info\n");
fprintf(stderr, " 2 = intense debugging info\n");
fprintf(stderr, " -t uses 'type' as the service type (default is '%s')\n", kDefaultServiceType);
fprintf(stderr, " -d uses 'domain' as the domain to browse (default is '%s')\n", kDefaultDomain);
}
static const char *gServiceType = kDefaultServiceType;
static const char *gServiceDomain = kDefaultDomain;
static void ParseArguments(int argc, char **argv)
// Parses our command line arguments into the global variables
// listed above.
{
int ch;
// Set gProgramName to the last path component of argv[0]
gProgramName = strrchr(argv[0], '/');
if (gProgramName == NULL) {
gProgramName = argv[0];
} else {
gProgramName += 1;
}
// Parse command line options using getopt.
do {
ch = getopt(argc, argv, "v:t:d:");
if (ch != -1) {
switch (ch) {
case 'v':
gMDNSPlatformPosixVerboseLevel = atoi(optarg);
if (gMDNSPlatformPosixVerboseLevel < 0 || gMDNSPlatformPosixVerboseLevel > 2) {
fprintf(stderr,
"%s: Verbose mode must be in the range 0..2\n",
gProgramName);
exit(1);
}
break;
case 't':
gServiceType = optarg;
if ( !CheckThatServiceTypeIsUsable(gServiceType, mDNStrue) ) {
exit(1);
}
break;
case 'd':
gServiceDomain = optarg;
break;
case '?':
default:
PrintUsage();
exit(1);
break;
}
}
} while (ch != -1);
// Check for any left over command line arguments.
if (optind != argc) {
fprintf(stderr, "%s: Unexpected argument '%s'\n", gProgramName, argv[optind]);
exit(1);
}
}
int main(int argc, char **argv)
// The program's main entry point. The program does a trivial
// mDNS query, looking for all AFP servers in the local domain.
{
int result;
mStatus status;
DNSQuestion question;
domainname type;
domainname domain;
// Parse our command line arguments. This won't come back if there's an error.
ParseArguments(argc, argv);
// Initialise the mDNS core.
status = mDNS_Init(&mDNSStorage, &PlatformStorage,
gRRCache, RR_CACHE_SIZE,
mDNS_Init_DontAdvertiseLocalAddresses,
mDNS_Init_NoInitCallback, mDNS_Init_NoInitCallbackContext);
if (status == mStatus_NoError) {
// Construct and start the query.
MakeDomainNameFromDNSNameString(&type, gServiceType);
MakeDomainNameFromDNSNameString(&domain, gServiceDomain);
status = mDNS_StartBrowse(&mDNSStorage, &question, &type, &domain, mDNSNULL, mDNSInterface_Any, 0, mDNSfalse, mDNSfalse, BrowseCallback, NULL);
// Run the platform main event loop until the user types ^C.
// The BrowseCallback routine is responsible for printing
// any results that we find.
if (status == mStatus_NoError) {
fprintf(stderr, "Hit ^C when you're bored waiting for responses.\n");
ExampleClientEventLoop(&mDNSStorage);
mDNS_StopQuery(&mDNSStorage, &question);
mDNS_Close(&mDNSStorage);
}
}
if (status == mStatus_NoError) {
result = 0;
} else {
result = 2;
}
if ( (result != 0) || (gMDNSPlatformPosixVerboseLevel > 0) ) {
fprintf(stderr, "%s: Finished with status %d, result %d\n", gProgramName, (int)status, result);
}
return 0;
}
