Source/DebuggerConnection.m

   1 /*
   2  * MacGDBp
   3  * Copyright (c) 2007 - 2010, 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 "DebuggerConnection.h"
  18
  19 #import <sys/socket.h>
  20 #import <netinet/in.h>
  21
  22 #import "AppDelegate.h"
  23 #import "LoggingController.h"
  24
  25 // DebuggerConnection (Private) ////////////////////////////////////////////////
  26
  27 @interface DebuggerConnection ()
  28
  29 @property (assign) CFSocketRef socket;
  30 @property (assign) CFReadStreamRef readStream;
  31 @property NSUInteger lastReadTransaction;
  32 @property (retain) NSMutableString* currentPacket;
  33 @property (assign) CFWriteStreamRef writeStream;
  34 @property NSUInteger lastWrittenTransaction;
  35 @property (retain) NSMutableArray* queuedWrites;
  36
  37 @end
  38
  39 // CFNetwork Callbacks /////////////////////////////////////////////////////////
  40
  41 void ReadStreamCallback(CFReadStreamRef stream, CFStreamEventType eventType, void* connectionRaw)
  42 {
  43         DebuggerConnection* connection = (DebuggerConnection*)connectionRaw;
  44         switch (eventType)
  45         {
  46                 case kCFStreamEventHasBytesAvailable:
  47                         [connection readStreamHasData];
  48                         break;
  49
  50                 case kCFStreamEventErrorOccurred:
  51                 {
  52                         CFErrorRef error = CFReadStreamCopyError(stream);
  53                         CFReadStreamUnscheduleFromRunLoop(stream, CFRunLoopGetCurrent(), kCFRunLoopCommonModes);
  54                         CFReadStreamClose(stream);
  55                         CFRelease(stream);
  56                         [connection errorEncountered:[[(NSError*)error autorelease] description]];
  57                         break;
  58                 }
  59
  60                 case kCFStreamEventEndEncountered:
  61                         CFReadStreamUnscheduleFromRunLoop(stream, CFRunLoopGetCurrent(), kCFRunLoopCommonModes);
  62                         CFReadStreamClose(stream);
  63                         CFRelease(stream);
  64                         [connection socketDisconnected];
  65                         break;
  66         };
  67 }
  68
  69 void WriteStreamCallback(CFWriteStreamRef stream, CFStreamEventType eventType, void* connectionRaw)
  70 {
  71         DebuggerConnection* connection = (DebuggerConnection*)connectionRaw;
  72         switch (eventType)
  73         {
  74                 case kCFStreamEventCanAcceptBytes:
  75                         [connection sendQueuedWrites];
  76                         break;
  77
  78                 case kCFStreamEventErrorOccurred:
  79                 {
  80                         CFErrorRef error = CFWriteStreamCopyError(stream);
  81                         CFWriteStreamUnscheduleFromRunLoop(stream, CFRunLoopGetCurrent(), kCFRunLoopCommonModes);
  82                         CFWriteStreamClose(stream);
  83                         CFRelease(stream);
  84                         [connection errorEncountered:[[(NSError*)error autorelease] description]];
  85                         break;
  86                 }
  87
  88                 case kCFStreamEventEndEncountered:
  89                         CFWriteStreamUnscheduleFromRunLoop(stream, CFRunLoopGetCurrent(), kCFRunLoopCommonModes);
  90                         CFWriteStreamClose(stream);
  91                         CFRelease(stream);
  92                         [connection socketDisconnected];
  93                         break;
  94         }
  95 }
  96
  97 void SocketAcceptCallback(CFSocketRef socket,
  98                                                                                                         CFSocketCallBackType callbackType,
  99                                                                                                         CFDataRef address,
 100                                                                                                         const void* data,
 101                                                                                                         void* connectionRaw)
 102 {
 103         assert(callbackType == kCFSocketAcceptCallBack);
 104         NSLog(@"SocketAcceptCallback()");
 105
 106         DebuggerConnection* connection = (DebuggerConnection*)connectionRaw;
 107
 108         CFReadStreamRef readStream;
 109         CFWriteStreamRef writeStream;
 110
 111         // Create the streams on the socket.
 112         CFStreamCreatePairWithSocket(kCFAllocatorDefault,
 113                                                                                                                          *(CFSocketNativeHandle*)data,  // Socket handle.
 114                                                                                                                          &readStream,  // Read stream in-pointer.
 115                                                                                                                          &writeStream);  // Write stream in-pointer.
 116
 117         // Create struct to register callbacks for the stream.
 118         CFStreamClientContext context;
 119         context.version = 0;
 120         context.info = connection;
 121         context.retain = NULL;
 122         context.release = NULL;
 123         context.copyDescription = NULL;
 124
 125         // Set the client of the read stream.
 126         CFOptionFlags readFlags =
 127         kCFStreamEventOpenCompleted |
 128         kCFStreamEventHasBytesAvailable |
 129         kCFStreamEventErrorOccurred |
 130         kCFStreamEventEndEncountered;
 131         if (CFReadStreamSetClient(readStream, readFlags, ReadStreamCallback, &context))
 132                 // Schedule in run loop to do asynchronous communication with the engine.
 133                 CFReadStreamScheduleWithRunLoop(readStream, CFRunLoopGetCurrent(), kCFRunLoopCommonModes);
 134         else
 135                 return;
 136
 137         // Open the stream now that it's scheduled on the run loop.
 138         if (!CFReadStreamOpen(readStream))
 139         {
 140                 CFStreamError error = CFReadStreamGetError(readStream);
 141                 NSLog(@"error! %@", error);
 142                 return;
 143         }
 144
 145         // Set the client of the write stream.
 146         CFOptionFlags writeFlags =
 147         kCFStreamEventOpenCompleted |
 148         kCFStreamEventCanAcceptBytes |
 149         kCFStreamEventErrorOccurred |
 150         kCFStreamEventEndEncountered;
 151         if (CFWriteStreamSetClient(writeStream, writeFlags, WriteStreamCallback, &context))
 152                 // Schedule it in the run loop to receive error information.
 153                 CFWriteStreamScheduleWithRunLoop(writeStream, CFRunLoopGetCurrent(), kCFRunLoopCommonModes);
 154         else
 155                 return;
 156
 157         // Open the write stream.
 158         if (!CFWriteStreamOpen(writeStream))
 159         {
 160                 CFStreamError error = CFWriteStreamGetError(writeStream);
 161                 NSLog(@"error! %@", error);
 162                 return;
 163         }
 164
 165         connection.readStream = readStream;
 166         connection.writeStream = writeStream;
 167         [connection socketDidAccept];
 168 }
 169
 170 ////////////////////////////////////////////////////////////////////////////////
 171
 172 @implementation DebuggerConnection
 173
 174 @synthesize port = port_;
 175 @synthesize connected = connected_;
 176 @synthesize delegate = delegate_;
 177
 178 @synthesize socket = socket_;
 179 @synthesize readStream = readStream_;
 180 @synthesize lastReadTransaction = lastReadTransaction_;
 181 @synthesize currentPacket = currentPacket_;
 182 @synthesize writeStream = writeStream_;
 183 @synthesize lastWrittenTransaction = lastWrittenTransaction_;
 184 @synthesize queuedWrites = queuedWrites_;
 185
 186 - (id)initWithPort:(NSUInteger)aPort
 187 {
 188         if (self = [super init])
 189         {
 190                 port_ = aPort;
 191         }
 192         return self;
 193 }
 194
 195 - (void)dealloc
 196 {
 197         self.currentPacket = nil;
 198         [super dealloc];
 199 }
 200
 201 /**
 202  * Called by SocketWrapper after the connection is successful. This immediately calls
 203  * -[SocketWrapper receive] to clear the way for communication, though the information
 204  * could be useful server information that we don't use right now.
 205  */
 206 - (void)socketDidAccept
 207 {
 208         connected_ = YES;
 209         transactionID = 1;
 210         self.queuedWrites = [NSMutableArray array];
 211         writeQueueLock_ = [NSRecursiveLock new];
 212 }
 213
 214 /**
 215  * Receives errors from the SocketWrapper and updates the display
 216  */
 217 - (void)errorEncountered:(NSString*)error
 218 {
 219         [delegate_ errorEncountered:error];
 220 }
 221
 222 /**
 223  * Creates, connects to, and schedules a CFSocket.
 224  */
 225 - (void)connect
 226 {
 227         // Pass ourselves to the callback so we don't have to use ugly globals.
 228         CFSocketContext context;
 229         context.version = 0;
 230         context.info = self;
 231         context.retain = NULL;
 232         context.release = NULL;
 233         context.copyDescription = NULL;
 234
 235         // Create the address structure.
 236         struct sockaddr_in address;
 237         memset(&address, 0, sizeof(address));
 238         address.sin_len = sizeof(address);
 239         address.sin_family = AF_INET;
 240         address.sin_port = htons(port_);
 241         address.sin_addr.s_addr = htonl(INADDR_ANY);
 242
 243         // Create the socket signature.
 244         CFSocketSignature signature;
 245         signature.protocolFamily = PF_INET;
 246         signature.socketType = SOCK_STREAM;
 247         signature.protocol = IPPROTO_TCP;
 248         signature.address = (CFDataRef)[NSData dataWithBytes:&address length:sizeof(address)];
 249
 250         socket_ = CFSocketCreateWithSocketSignature(kCFAllocatorDefault,
 251                                                                                                                                                                                         &signature,  // Socket signature.
 252                                                                                                                                                                                         kCFSocketAcceptCallBack,  // Callback types.
 253                                                                                                                                                                                         SocketAcceptCallback,  // Callout function pointer.
 254                                                                                                                                                                                         &context);  // Context to pass to callout.
 255         if (!socket_)
 256         {
 257                 [self errorEncountered:@"Could not open socket."];
 258                 return;
 259         }
 260
 261         // Allow old, yet-to-be recycled sockets to be reused.
 262         BOOL yes = YES;
 263         setsockopt(CFSocketGetNative(socket_), SOL_SOCKET, SO_REUSEADDR, &yes, sizeof(BOOL));
 264
 265         // Schedule the socket on the run loop.
 266         CFRunLoopSourceRef source = CFSocketCreateRunLoopSource(kCFAllocatorDefault, socket_, 0);
 267         CFRunLoopAddSource(CFRunLoopGetCurrent(), source, kCFRunLoopCommonModes);
 268         CFRelease(source);
 269 }
 270
 271 /**
 272  * Closes a socket and releases the ref.
 273  */
 274 - (void)close
 275 {
 276         // The socket goes down, so do the streams, which clean themselves up.
 277         CFSocketInvalidate(socket_);
 278         CFRelease(socket_);
 279         self.queuedWrites = nil;
 280         [writeQueueLock_ release];
 281 }
 282
 283 /**
 284  * Notification that the socket disconnected.
 285  */
 286 - (void)socketDisconnected
 287 {
 288         [self close];
 289         [delegate_ connectionDidCose:self];
 290 }
 291
 292 /**
 293  * Callback from the CFReadStream that there is data waiting to be read.
 294  */
 295 - (void)readStreamHasData
 296 {
 297         const NSUInteger kBufferSize = 1024;
 298         UInt8 buffer[kBufferSize];
 299         CFIndex bufferOffset = 0;  // Starting point in |buffer| to work with.
 300         CFIndex bytesRead = CFReadStreamRead(readStream_, buffer, kBufferSize);
 301         const char* charBuffer = (const char*)buffer;
 302
 303         // The read loop works by going through the buffer until all the bytes have
 304         // been processed.
 305         while (bufferOffset < bytesRead)
 306         {
 307                 // Find the NULL separator, or the end of the string.
 308                 NSUInteger partLength = 0;
 309                 for (NSUInteger i = bufferOffset; i < bytesRead && charBuffer[i] != '\0'; ++i, ++partLength) ;
 310
 311                 // If there is not a current packet, set some state.
 312                 if (!self.currentPacket)
 313                 {
 314                         // Read the message header: the size.  This will be |partLength| bytes.
 315                         packetSize_ = atoi(charBuffer + bufferOffset);
 316                         currentPacketIndex_ = 0;
 317                         self.currentPacket = [NSMutableString stringWithCapacity:packetSize_];
 318                         bufferOffset += partLength + 1;  // Pass over the NULL byte.
 319                         continue;  // Spin the loop to begin reading actual data.
 320                 }
 321
 322                 // Substring the byte stream and append it to the packet string.
 323                 CFStringRef bufferString = CFStringCreateWithBytes(kCFAllocatorDefault,
 324                                                                                                                                                                                                                          buffer + bufferOffset,  // Byte pointer, offset by start index.
 325                                                                                                                                                                                                                          partLength,  // Length.
 326                                                                                                                                                                                                                          kCFStringEncodingUTF8,
 327                                                                                                                                                                                                                          true);
 328                 [self.currentPacket appendString:(NSString*)bufferString];
 329                 CFRelease(bufferString);
 330
 331                 // Advance counters.
 332                 currentPacketIndex_ += partLength;
 333                 bufferOffset += partLength + 1;
 334
 335                 // If this read finished the packet, handle it and reset.
 336                 NSLog(@"cpi %d ps %d br %d ds %d", currentPacketIndex_, packetSize_, bytesRead, partLength);
 337                 if (currentPacketIndex_ >= packetSize_)
 338                 {
 339                         [self handlePacket:[[currentPacket_ retain] autorelease]];
 340                         self.currentPacket = nil;
 341                         packetSize_ = 0;
 342                         currentPacketIndex_ = 0;
 343                 }
 344         }
 345 }
 346
 347 /**
 348  * Performs the packet handling of a raw string XML packet. From this point on,
 349  * the packets are associated with a transaction and are then dispatched.
 350  */
 351 - (void)handlePacket:(NSString*)packet
 352 {
 353         // Test if we can convert it into an NSXMLDocument.
 354         NSError* error = nil;
 355         NSXMLDocument* xmlTest = [[NSXMLDocument alloc] initWithXMLString:currentPacket_ options:NSXMLDocumentTidyXML error:&error];
 356
 357         // Try to recover if we encountered an error.
 358         if (!xmlTest)
 359         {
 360                 // We do not want to starve the write queue, so manually parse out the
 361                 // transaction ID.
 362                 NSRange location = [currentPacket_ rangeOfString:@"transaction_id"];
 363                 if (location.location != NSNotFound)
 364                 {
 365                         NSUInteger start = location.location + location.length;
 366                         NSUInteger end = start;
 367
 368                         NSCharacterSet* numericSet = [NSCharacterSet decimalDigitCharacterSet];
 369
 370                         // Loop over the characters after the attribute name to extract the ID.
 371                         while (end < [currentPacket_ length])
 372                         {
 373                                 unichar c = [currentPacket_ characterAtIndex:end];
 374                                 if ([numericSet characterIsMember:c])
 375                                 {
 376                                         // If this character is numeric, extend the range to substring.
 377                                         ++end;
 378                                 }
 379                                 else
 380                                 {
 381                                         if (start == end)
 382                                         {
 383                                                 // If this character is nonnumeric and we have nothing in the
 384                                                 // range, skip this character.
 385                                                 ++start;
 386                                                 ++end;
 387                                         }
 388                                         else
 389                                         {
 390                                                 // We've moved past the numeric ID so we should stop searching.
 391                                                 break;
 392                                         }
 393                                 }
 394                         }
 395
 396                         // If we were able to extract the transaction ID, update the last read.
 397                         NSRange substringRange = NSMakeRange(start, end - start);
 398                         NSString* transactionStr = [currentPacket_ substringWithRange:substringRange];
 399                         if ([transactionStr length])
 400                                 lastReadTransaction_ = [transactionStr intValue];
 401                 }
 402
 403                 // Otherwise, assume +1 and hope it works.
 404                 ++lastReadTransaction_;
 405         }
 406         else
 407         {
 408                 // See if the transaction can be parsed out.
 409                 NSInteger transaction = [self transactionIDFromResponse:xmlTest];
 410                 if (transaction < lastReadTransaction_)
 411                 {
 412                         NSLog(@"tx = %d vs %d", transaction, lastReadTransaction_);
 413                         NSLog(@"out of date transaction %@", packet);
 414                         return;
 415                 }
 416
 417                 if (transaction != lastWrittenTransaction_)
 418                         NSLog(@"txn %d <> %d last written, %d last read", transaction, lastWrittenTransaction_, lastReadTransaction_);
 419
 420                 lastReadTransaction_ = transaction;
 421         }
 422
 423         // Log this receive event.
 424         LoggingController* logger = [(AppDelegate*)[NSApp delegate] loggingController];
 425         LogEntry* log = [logger recordReceive:currentPacket_];
 426         log.error = error;
 427         log.lastWrittenTransactionID = lastWrittenTransaction_;
 428         log.lastReadTransactionID = lastReadTransaction_;
 429
 430         // Finally, dispatch the handler for this response.
 431         [self handleResponse:[xmlTest autorelease]];
 432 }
 433
 434 /**
 435  * Writes a command into the write stream. If the stream is ready for writing,
 436  * we do so immediately. If not, the command is queued and will be written
 437  * when the stream is ready.
 438  */
 439 - (void)send:(NSString*)command
 440 {
 441         if (lastReadTransaction_ >= lastWrittenTransaction_ && CFWriteStreamCanAcceptBytes(writeStream_))
 442                 [self performSend:command];
 443         else
 444                 [queuedWrites_ addObject:command];
 445         [self sendQueuedWrites];
 446 }
 447
 448 /**
 449  * This performs a blocking send. This should ONLY be called when we know we
 450  * have write access to the stream. We will busy wait in case we don't do a full
 451  * send.
 452  */
 453 - (void)performSend:(NSString*)command
 454 {
 455         // If this is an out-of-date transaction, do not bother sending it.
 456         NSInteger transaction = [self transactionIDFromCommand:command];
 457         if (transaction != NSNotFound && transaction < lastWrittenTransaction_)
 458                 return;
 459
 460         BOOL done = NO;
 461
 462         char* string = (char*)[command UTF8String];
 463         int stringLength = strlen(string);
 464
 465         // Busy wait while writing. BAADD. Should background this operation.
 466         while (!done)
 467         {
 468                 if (CFWriteStreamCanAcceptBytes(writeStream_))
 469                 {
 470                         // Include the NULL byte in the string when we write.
 471                         int bytesWritten = CFWriteStreamWrite(writeStream_, (UInt8*)string, stringLength + 1);
 472                         if (bytesWritten < 0)
 473                         {
 474                                 NSLog(@"write error");
 475                         }
 476                         // Incomplete write.
 477                         else if (bytesWritten < strlen(string))
 478                         {
 479                                 // Adjust the buffer and wait for another chance to write.
 480                                 stringLength -= bytesWritten;
 481                                 memmove(string, string + bytesWritten, stringLength);
 482                         }
 483                         else
 484                         {
 485                                 done = YES;
 486
 487                                 // We need to scan the string to find the transactionID.
 488                                 if (transaction == NSNotFound)
 489                                 {
 490                                         NSLog(@"sent %@ without a transaction ID", command);
 491                                         continue;
 492                                 }
 493                                 lastWrittenTransaction_ = transaction;
 494                         }
 495                 }
 496         }
 497
 498         // Log this trancation.
 499         LoggingController* logger = [(AppDelegate*)[NSApp delegate] loggingController];
 500         LogEntry* log = [logger recordSend:command];
 501         log.lastWrittenTransactionID = lastWrittenTransaction_;
 502         log.lastReadTransactionID = lastReadTransaction_;
 503 }
 504
 505 - (void)handleResponse:(NSXMLDocument*)response
 506 {
 507         // Check and see if there's an error.
 508         NSArray* error = [[response rootElement] elementsForName:@"error"];
 509         if ([error count] > 0)
 510         {
 511                 NSLog(@"Xdebug error: %@", error);
 512                 [delegate_ errorEncountered:[[[[error objectAtIndex:0] children] objectAtIndex:0] stringValue]];
 513         }
 514
 515         if ([[[response rootElement] name] isEqualToString:@"init"])
 516         {
 517                 [delegate_ handleInitialResponse:response];
 518                 return;
 519         }
 520
 521         if ([delegate_ respondsToSelector:@selector(handleResponse:)])
 522                 [(NSObject*)delegate_ performSelectorOnMainThread:@selector(handleResponse:) withObject:response waitUntilDone:NO];
 523
 524         [self sendQueuedWrites];
 525 }
 526
 527 #pragma mark Private
 528
 529 /**
 530  * This will send a command to the debugger engine. It will append the
 531  * transaction ID automatically. It accepts a NSString command along with a
 532  * a variable number of arguments to substitute into the command, a la
 533  * +[NSString stringWithFormat:]. Returns the transaction ID as a NSNumber.
 534  */
 535 - (NSNumber*)sendCommandWithFormat:(NSString*)format, ...
 536 {
 537         // Collect varargs and format command.
 538         va_list args;
 539         va_start(args, format);
 540         NSString* command = [[NSString alloc] initWithFormat:format arguments:args];
 541         va_end(args);
 542
 543         NSNumber* callbackKey = [NSNumber numberWithInt:transactionID++];
 544         [self send:[NSString stringWithFormat:@"%@ -i %@", [command autorelease], callbackKey]];
 545
 546         return callbackKey;
 547 }
 548
 549 /**
 550  * Checks if there are unsent commands in the |queuedWrites_| queue and sends
 551  * them if it's OK to do so. This will not block.
 552  */
 553 - (void)sendQueuedWrites
 554 {
 555         if (!connected_)
 556                 return;
 557
 558         [writeQueueLock_ lock];
 559         if (lastReadTransaction_ >= lastWrittenTransaction_ && [queuedWrites_ count] > 0)
 560         {
 561                 NSString* command = [queuedWrites_ objectAtIndex:0];
 562
 563                 // We don't want to block because this is called from the main thread.
 564                 // |-performSend:| busy waits when the stream is not ready. Bail out
 565                 // before we do that becuase busy waiting is BAD.
 566                 if (CFWriteStreamCanAcceptBytes(writeStream_))
 567                 {
 568                         [self performSend:command];
 569                         [queuedWrites_ removeObjectAtIndex:0];
 570                 }
 571         }
 572         [writeQueueLock_ unlock];
 573 }
 574
 575
 576 /**
 577  * Returns the transaction_id from an NSXMLDocument.
 578  */
 579 - (NSInteger)transactionIDFromResponse:(NSXMLDocument*)response
 580 {
 581         return [[[[response rootElement] attributeForName:@"transaction_id"] stringValue] intValue];
 582 }
 583
 584 /**
 585  * Scans a command string for the transaction ID component. If it is not found,
 586  * returns NSNotFound.
 587  */
 588 - (NSInteger)transactionIDFromCommand:(NSString*)command
 589 {
 590         NSRange occurrence = [command rangeOfString:@"-i "];
 591         if (occurrence.location == NSNotFound)
 592                 return NSNotFound;
 593         NSString* transaction = [command substringFromIndex:occurrence.location + occurrence.length];
 594         return [transaction intValue];
 595 }
 596
 597 /**
 598  * Given a file path, this returns a file:// URI and escapes any spaces for the
 599  * debugger engine.
 600  */
 601 - (NSString*)escapedURIPath:(NSString*)path
 602 {
 603         // Custon GDBp paths are fine.
 604         if ([[path substringToIndex:4] isEqualToString:@"gdbp"])
 605                 return path;
 606
 607         // Create a temporary URL that will escape all the nasty characters.
 608         NSURL* url = [NSURL fileURLWithPath:path];
 609         NSString* urlString = [url absoluteString];
 610
 611         // Remove the host because this is a file:// URL;
 612         urlString = [urlString stringByReplacingOccurrencesOfString:[url host] withString:@""];
 613
 614         // Escape % for use in printf-style NSString formatters.
 615         urlString = [urlString stringByReplacingOccurrencesOfString:@"%" withString:@"%%"];
 616         return urlString;
 617 }
 618
 619 @end