Source/SocketWrapper.m

   1 /*
   2  * MacGDBp
   3  * Copyright (c) 2002 - 2007, Blue Static <http://www.bluestatic.org>
   4  *
   5  * This program is free software; you can redistribute it and/or modify it under the terms of the GNU
   6  * General Public License as published by the Free Software Foundation; either version 2 of the
   7  * License, or (at your option) any later version.
   8  *
   9  * This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without
  10  * even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  11  * General Public License for more details.
  12  *
  13  * You should have received a copy of the GNU General Public License along with this program; if not,
  14  * write to the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA
  15  */
  16
  17 #import "SocketWrapper.h"
  18 #include <sys/types.h>
  19 #include <sys/socket.h>
  20 #include <netinet/in.h>
  21 #include <arpa/inet.h>
  22 #include <unistd.h>
  23
  24 NSString *SocketWrapperDidErrorNotification = @"errorOccurred";
  25 NSString *SocketWrapperSocketDidBindNotification = @"bindSuccess";
  26 NSString *SocketWrapperSocketDidAcceptNotification = @"acceptSuccess";
  27 NSString *SocketWrapperDataReceivedNotification = @"dataReceived";
  28 NSString *SocketWrapperDataSentNotification = @"dataSent";
  29
  30 @implementation SocketWrapper
  31
  32 /**
  33  * Initializes the socket wrapper with a host and port
  34  */
  35 - (id)initWithPort: (int)port
  36 {
  37         if (self = [super init])
  38         {
  39                 // create an INET socket that we'll be listen()ing on
  40                 int socketOpen = socket(PF_INET, SOCK_STREAM, 0);
  41
  42                 // create our address given the port
  43                 struct sockaddr_in address;
  44                 address.sin_family = AF_INET;
  45                 address.sin_port = htons(port);
  46                 address.sin_addr.s_addr = htonl(INADDR_ANY);
  47                 memset(address.sin_zero, '\0', sizeof(address.sin_zero));
  48
  49                 // bind the socket... and don't give up until we've tried for a while
  50                 int tries = 0;
  51                 while (bind(socketOpen, (struct sockaddr *)&address, sizeof(address)) < 0)
  52                 {
  53                         if (tries >= 5)
  54                         {
  55                                 close(socketOpen);
  56                                 [_delegate errorEncountered: nil];
  57                                 return nil;
  58                         }
  59                         NSLog(@"couldn't bind to the socket... trying again in 5");
  60                         sleep(5);
  61                         tries++;
  62                 }
  63                 [_delegate socketDidAccept];
  64
  65                 // now we just have to keep our ears open
  66                 if (listen(socketOpen, 0) == -1)
  67                 {
  68                         [_delegate errorEncountered: nil];
  69                         return nil;
  70                 }
  71
  72                 // accept a connection
  73                 struct sockaddr_in remoteAddress;
  74                 socklen_t remoteAddressLen = sizeof(remoteAddress);
  75                 _socket = accept(socketOpen, (struct sockaddr *)&remoteAddress, &remoteAddressLen);
  76                 if (_socket < 0)
  77                 {
  78                         close(socketOpen);
  79                         [_delegate errorEncountered: nil];
  80                         return nil;
  81                 }
  82                 [_delegate socketDidAccept];
  83
  84                 // we're done listening now that we have a connection
  85                 close(socketOpen);
  86         }
  87         return self;
  88 }
  89
  90 /**
  91  * Close our socket and clean up anything else
  92  */
  93 - (void)dealloc
  94 {
  95         close(_socket);
  96
  97         [super dealloc];
  98 }
  99
 100 /**
 101  * Returns the delegate
 102  */
 103 - (id)delegate
 104 {
 105         return _delegate;
 106 }
 107
 108 /**
 109  * Sets the delegate but does *not* retain it
 110  */
 111 - (void)setDelegate: (id)delegate
 112 {
 113         _delegate = delegate;
 114 }
 115
 116 /**
 117  * Reads from the socket and returns the result as a NSString (because it's always going to be XML). Be aware
 118  * that the underlying socket recv() call will *wait* for the server to send a message, so be sure that this
 119  * is used either in a threaded environment so the interface does not hang, or when you *know* the server
 120  * will return something (which we almost always do).
 121  *
 122  * Data string returned is autorelease'd
 123  */
 124 - (void)receive
 125 {
 126         // create a buffer
 127         char buffer[1024];
 128
 129         // do our initial recv() call to get (hopefully) all the data and the lengh of the packet
 130         int recvd = recv(_socket, &buffer, sizeof(buffer), 0);
 131
 132         // take the received data and put it into an NSData
 133         NSMutableData *data = [NSMutableData data];
 134
 135         // strip the length from the packet, and clear the null byte then add it to the NSData
 136         char packetLength[32];
 137         int i = 0;
 138         do
 139         {
 140                 packetLength[i] = buffer[i];
 141                 i++;
 142         } while (buffer[i] != '\0');
 143         // the length of the packet
 144         // packet is formatted in len<null>packet
 145         int length = atoi(packetLength);
 146
 147         // take our bytes and convert them to NSData
 148         char packet[sizeof(buffer)];
 149         strcpy(packet, &buffer[i + 1]);
 150         [data appendBytes: packet length: recvd];
 151
 152         // check if we have a partial packet
 153         if (length + sizeof(length) > sizeof(buffer))
 154         {
 155                 while (recvd < length)
 156                 {
 157                         int latest = recv(_socket, &buffer, sizeof(buffer), 0);
 158                         if (latest < 1)
 159                         {
 160                                 NSLog(@"socket closed or error");
 161                         }
 162                         [data appendBytes: buffer length: latest];
 163                         recvd += latest;
 164                 }
 165         }
 166
 167         // convert the NSData into a NSString
 168         NSString *string = [[NSString alloc] initWithData: data encoding: NSUTF8StringEncoding];
 169
 170         [_delegate dataReceived: string];
 171
 172         //return string;
 173 }
 174
 175 /**
 176  * Sends a given NSString over the socket
 177  */
 178 - (void)send: (NSString *)data
 179 {
 180         data = [NSString stringWithFormat: @"%@\0", data];
 181         int sent = send(_socket, [data UTF8String], [data length], 0);
 182         if (sent < 0)
 183         {
 184                 NSLog(@"error in sending");
 185         }
 186         if (sent < [data length])
 187         {
 188                 // TODO - do we really need to worry about partial sends with the lenght of our commands?
 189                 NSLog(@"FAIL: only partial packet was sent; sent %d bytes", sent);
 190         }
 191
 192         [_delegate dataSent];
 193 }
 194
 195 @end