main.m

/*
    File:       main.m
 
    Contains:   A command line tool to exercise the UDPEcho class.
 
    Written by: DTS
 
    Copyright:  Copyright (c) 2010-2012 Apple Inc. All Rights Reserved.
 
    Disclaimer: IMPORTANT: This Apple software is supplied to you by Apple Inc.
                ("Apple") in consideration of your agreement to the following
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                original Apple software (the "Apple Software"), to use,
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                THE APPLE SOFTWARE OR ITS USE AND OPERATION ALONE OR IN
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                IN NO EVENT SHALL APPLE BE LIABLE FOR ANY SPECIAL, INDIRECT,
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*/
 
#import "UDPEcho.h"
 
#include <netdb.h>
 
#pragma mark * Utilities
 
static NSString * DisplayAddressForAddress(NSData * address)
    // Returns a dotted decimal string for the specified address (a (struct sockaddr) 
    // within the address NSData).
{
    int         err;
    NSString *  result;
    char        hostStr[NI_MAXHOST];
    char        servStr[NI_MAXSERV];
    
    result = nil;
    
    if (address != nil) {
 
        // If it's a IPv4 address embedded in an IPv6 address, just bring it as an IPv4 
        // address.  Remember, this is about display, not functionality, and users don't 
        // want to see mapped addresses.
        
        if ([address length] >= sizeof(struct sockaddr_in6)) {
            const struct sockaddr_in6 * addr6Ptr;
            
            addr6Ptr = [address bytes];
            if (addr6Ptr->sin6_family == AF_INET6) {
                if ( IN6_IS_ADDR_V4MAPPED(&addr6Ptr->sin6_addr) || IN6_IS_ADDR_V4COMPAT(&addr6Ptr->sin6_addr) ) {
                    struct sockaddr_in  addr4;
                    
                    memset(&addr4, 0, sizeof(addr4));
                    addr4.sin_len         = sizeof(addr4);
                    addr4.sin_family      = AF_INET;
                    addr4.sin_port        = addr6Ptr->sin6_port;
                    addr4.sin_addr.s_addr = addr6Ptr->sin6_addr.__u6_addr.__u6_addr32[3];
                    address = [NSData dataWithBytes:&addr4 length:sizeof(addr4)];
                    assert(address != nil);
                }
            }
        }
        err = getnameinfo([address bytes], (socklen_t) [address length], hostStr, sizeof(hostStr), servStr, sizeof(servStr), NI_NUMERICHOST | NI_NUMERICSERV);
        if (err == 0) {
            result = [NSString stringWithFormat:@"%s:%s", hostStr, servStr];
            assert(result != nil);
        }
    }
 
    return result;
}
 
static NSString * DisplayStringFromData(NSData *data)
    // Returns a human readable string for the given data.
{
    NSMutableString *   result;
    NSUInteger          dataLength;
    NSUInteger          dataIndex;
    const uint8_t *     dataBytes;
 
    assert(data != nil);
    
    dataLength = [data length];
    dataBytes  = [data bytes];
 
    result = [NSMutableString stringWithCapacity:dataLength];
    assert(result != nil);
 
    [result appendString:@"\""];
    for (dataIndex = 0; dataIndex < dataLength; dataIndex++) {
        uint8_t     ch;
        
        ch = dataBytes[dataIndex];
        if (ch == 10) {
            [result appendString:@"\n"];
        } else if (ch == 13) {
            [result appendString:@"\r"];
        } else if (ch == '"') {
            [result appendString:@"\\\""];
        } else if (ch == '\\') {
            [result appendString:@"\\\\"];
        } else if ( (ch >= ' ') && (ch < 127) ) {
            [result appendFormat:@"%c", (int) ch];
        } else {
            [result appendFormat:@"\\x%02x", (unsigned int) ch];
        }
    }
    [result appendString:@"\""];
    
    return result;
}
 
static NSString * DisplayErrorFromError(NSError *error)
    // Given an NSError, returns a short error string that we can print, handling 
    // some special cases along the way.
{
    NSString *      result;
    NSNumber *      failureNum;
    int             failure;
    const char *    failureStr;
    
    assert(error != nil);
    
    result = nil;
    
    // Handle DNS errors as a special case.
    
    if ( [[error domain] isEqual:(NSString *)kCFErrorDomainCFNetwork] && ([error code] == kCFHostErrorUnknown) ) {
        failureNum = [[error userInfo] objectForKey:(id)kCFGetAddrInfoFailureKey];
        if ( [failureNum isKindOfClass:[NSNumber class]] ) {
            failure = [failureNum intValue];
            if (failure != 0) {
                failureStr = gai_strerror(failure);
                if (failureStr != NULL) {
                    result = [NSString stringWithUTF8String:failureStr];
                    assert(result != nil);
                }
            }
        }
    }
    
    // Otherwise try various properties of the error object.
    
    if (result == nil) {
        result = [error localizedFailureReason];
    }
    if (result == nil) {
        result = [error localizedDescription];
    }
    if (result == nil) {
        result = [error description];
    }
    assert(result != nil);
    return result;
}
 
#pragma mark * Main
 
@interface Main : NSObject <UDPEchoDelegate>
 
- (BOOL)runServerOnPort:(NSUInteger)port;
- (BOOL)runClientWithHost:(NSString *)host port:(NSUInteger)port;
 
@end
 
@interface Main ()
 
@property (nonatomic, strong, readwrite) UDPEcho *      echo;
@property (nonatomic, strong, readwrite) NSTimer *      sendTimer;
@property (nonatomic, assign, readwrite) NSUInteger     sendCount;
 
@end
 
@implementation Main
 
@synthesize echo      = _echo;
@synthesize sendTimer = _sendTimer;
@synthesize sendCount = _sendCount;
 
- (void)dealloc
{
    [self->_echo stop];
    [self->_sendTimer invalidate];
}
 
- (BOOL)runServerOnPort:(NSUInteger)port
    // One of two Objective-C 'mains' for this program.  This creates a UDPEcho 
    // object and runs it in server mode.
{
    assert(self.echo == nil);
    
    self.echo = [[UDPEcho alloc] init];
    assert(self.echo != nil);
    
    self.echo.delegate = self;
 
    [self.echo startServerOnPort:port];
    
    while (self.echo != nil) {
        [[NSRunLoop currentRunLoop] runMode:NSDefaultRunLoopMode beforeDate:[NSDate distantFuture]];
    }
    
    // The loop above is supposed to run forever.  If it doesn't, something must 
    // have failed and we want main to return EXIT_FAILURE.
    
    return NO;
}
 
- (BOOL)runClientWithHost:(NSString *)host port:(NSUInteger)port
    // One of two Objective-C 'mains' for this program.  This creates a UDPEcho 
    // object in client mode, talking to the specified host and port, and then 
    // periodically sends packets via that object.
{
    assert(host != nil);
    assert( (port > 0) && (port < 65536) );
 
    assert(self.echo == nil);
 
    self.echo = [[UDPEcho alloc] init];
    assert(self.echo != nil);
    
    self.echo.delegate = self;
 
    [self.echo startConnectedToHostName:host port:port];
    
    while (self.echo != nil) {
        [[NSRunLoop currentRunLoop] runMode:NSDefaultRunLoopMode beforeDate:[NSDate distantFuture]];
    }
    
    // The loop above is supposed to run forever.  If it doesn't, something must 
    // have failed and we want main to return EXIT_FAILURE.
    
    return NO;
}
 
- (void)sendPacket
    // Called by the client code to send a UDP packet.  This is called immediately 
    // after the client has 'connected', and periodically after that from the send 
    // timer.
{
    NSData *    data;
 
    assert(self.echo != nil);
    assert( ! self.echo.isServer );
    
    data = [[NSString stringWithFormat:@"%zu bottles of beer on the wall", (99 - self.sendCount)] dataUsingEncoding:NSUTF8StringEncoding];
    assert(data != nil);
    
    [self.echo sendData:data];
 
    self.sendCount += 1;
    if (self.sendCount > 99) {
        self.sendCount = 0;
    }
}
 
- (void)echo:(UDPEcho *)echo didReceiveData:(NSData *)data fromAddress:(NSData *)addr
    // This UDPEcho delegate method is called after successfully receiving data.
{
    assert(echo == self.echo);
    #pragma unused(echo)
    assert(data != nil);
    assert(addr != nil);
    NSLog(@"received %@ from %@", DisplayStringFromData(data), DisplayAddressForAddress(addr));
}
 
- (void)echo:(UDPEcho *)echo didReceiveError:(NSError *)error
    // This UDPEcho delegate method is called after a failure to receive data.
{
    assert(echo == self.echo);
    #pragma unused(echo)
    assert(error != nil);
    NSLog(@"received error: %@", DisplayErrorFromError(error));
}
 
- (void)echo:(UDPEcho *)echo didSendData:(NSData *)data toAddress:(NSData *)addr
    // This UDPEcho delegate method is called after successfully sending data.
{
    assert(echo == self.echo);
    #pragma unused(echo)
    assert(data != nil);
    assert(addr != nil);
    NSLog(@"    sent %@ to   %@", DisplayStringFromData(data), DisplayAddressForAddress(addr));
}
 
- (void)echo:(UDPEcho *)echo didFailToSendData:(NSData *)data toAddress:(NSData *)addr error:(NSError *)error
    // This UDPEcho delegate method is called after a failure to send data.
{
    assert(echo == self.echo);
    #pragma unused(echo)
    assert(data != nil);
    assert(addr != nil);
    assert(error != nil);
    NSLog(@" sending %@ to   %@, error: %@", DisplayStringFromData(data), DisplayAddressForAddress(addr), DisplayErrorFromError(error));
}
 
- (void)echo:(UDPEcho *)echo didStartWithAddress:(NSData *)address
    // This UDPEcho delegate method is called after the object has successfully started up.
{
    assert(echo == self.echo);
    #pragma unused(echo)
    assert(address != nil);
    
    if (self.echo.isServer) {
        NSLog(@"receiving on %@", DisplayAddressForAddress(address));
    } else {
        NSLog(@"sending to %@", DisplayAddressForAddress(address));
    }
    
    if ( ! self.echo.isServer ) {
        [self sendPacket];
        
        assert(self.sendTimer == nil);
        self.sendTimer = [NSTimer scheduledTimerWithTimeInterval:1.0 target:self selector:@selector(sendPacket) userInfo:nil repeats:YES];
    }
}
 
- (void)echo:(UDPEcho *)echo didStopWithError:(NSError *)error
    // This UDPEcho delegate method is called  after the object stops spontaneously.
{
    assert(echo == self.echo);
    #pragma unused(echo)
    assert(error != nil);
    NSLog(@"failed with error: %@", DisplayErrorFromError(error));
    self.echo = nil;
}
 
@end
 
int main(int argc, char **argv)
{
    #pragma unused(argc)
    #pragma unused(argv)
    int                 retVal;
    BOOL                success;
    Main *              mainObj;
    int                 port;
    
    @autoreleasepool {
        retVal = EXIT_FAILURE;
        success = YES;
        if ( (argc >= 2) && (argc <= 3) ) {
            if (argc == 3) {
                port = atoi(argv[2]);
            } else {
                port = 7;
            }
            if ( (port > 0) && (port < 65536) ) {
                if (strcmp(argv[1], "-l") == 0) {
                    retVal = EXIT_SUCCESS;
 
                    // server mode
 
                    mainObj = [[Main alloc] init];
                    assert(mainObj != nil);
                    
                    success = [mainObj runServerOnPort:(NSUInteger) port];
                } else {
                    NSString *  hostName;
                    
                    hostName = [NSString stringWithUTF8String:argv[1]];
                    if (hostName == nil) {
                        fprintf(stderr, "%s: invalid host host: %s\n", getprogname(), argv[1]);
                    } else {
                        retVal = EXIT_SUCCESS;
 
                        // client mode
 
                        mainObj = [[Main alloc] init];
                        assert(mainObj != nil);
                        
                        success = [mainObj runClientWithHost:hostName port:(NSUInteger) port];
                    }
                }
            }
        }
        
        if (success) {
            if (retVal == EXIT_FAILURE) {
                fprintf(stderr, "usage: %s -l [port]\n",   getprogname());
                fprintf(stderr, "       %s host [port]\n", getprogname());
            }
        } else {
            retVal = EXIT_FAILURE;
        }
    }
        
    return retVal;
}


Copyright © 2012 Apple Inc. All Rights Reserved. Terms of Use | Privacy Policy | Updated: 2012-08-17