/* * Copyright (c) 2008, 2009, 2010, 2011, 2012, 2013, 2014, 2015, 2016, 2017 * Jonathan Schleifer <js@heap.zone> * * All rights reserved. * * This file is part of ObjFW. It may be distributed under the terms of the * Q Public License 1.0, which can be found in the file LICENSE.QPL included in * the packaging of this file. * * Alternatively, it may be distributed under the terms of the GNU General * Public License, either version 2 or 3, which can be found in the file * LICENSE.GPLv2 or LICENSE.GPLv3 respectively included in the packaging of this * file. */ #include "config.h" #import "OFApplication.h" #import "OFArray.h" #import "OFDataArray.h" #import "OFDictionary.h" #import "OFFile.h" #import "OFFileManager.h" #import "OFHTTPClient.h" #import "OFHTTPRequest.h" #import "OFHTTPResponse.h" #import "OFOptionsParser.h" #import "OFStdIOStream.h" #import "OFSystemInfo.h" #import "OFTCPSocket.h" #import "OFURL.h" #import "OFLocalization.h" #import "OFAddressTranslationFailedException.h" #import "OFConnectionFailedException.h" #import "OFHTTPRequestFailedException.h" #import "OFInvalidFormatException.h" #import "OFInvalidServerReplyException.h" #import "OFOpenItemFailedException.h" #import "OFOutOfRangeException.h" #import "OFReadFailedException.h" #import "OFStatItemFailedException.h" #import "OFUnsupportedProtocolException.h" #import "OFWriteFailedException.h" #import "ProgressBar.h" #define GIBIBYTE (1024 * 1024 * 1024) #define MEBIBYTE (1024 * 1024) #define KIBIBYTE (1024) @interface OFHTTP: OFObject <OFHTTPClientDelegate> { OFArray OF_GENERIC(OFString*) *_URLs; size_t _URLIndex; int _errorCode; OFString *_outputPath; bool _continue, _force, _detectFileName, _quiet, _verbose; OFDataArray *_body; of_http_request_method_t _method; OFMutableDictionary *_clientHeaders; OFHTTPClient *_HTTPClient; char *_buffer; OFStream *_output; intmax_t _received, _length, _resumedFrom; ProgressBar *_progressBar; } @end OF_APPLICATION_DELEGATE(OFHTTP) static void help(OFStream *stream, bool full, int status) { [of_stderr writeString: OF_LOCALIZED(@"usage", @"Usage: %[prog] -[cehHmoOPqv] url1 [url2 ...]\n", @"prog", [OFApplication programName])]; if (full) [stream writeString: OF_LOCALIZED(@"full_usage", @"\nOptions:\n " @"-b --body " @" Specify the file to send as body\n " @"-c --continue " @" Continue download of existing file\n " @"-f --force " @" Force / overwrite existing file\n " @"-h --help " @" Show this help\n " @"-H --header " @" Add a header (e.g. X-Foo:Bar)\n " @"-m --method " @" Set the method of the HTTP request\n " @"-o --output " @" Specify output file name\n " @"-O --detect-filename" @" Do a HEAD request to detect the file name\n " @"-P --proxy " @" Specify SOCKS5 proxy\n " @"-q --quiet " @" Quiet mode (no output, except errors)\n " @"-v --verbose " @" Verbose mode (print headers)\n")]; [OFApplication terminateWithStatus: status]; } @implementation OFHTTP - init { self = [super init]; @try { _method = OF_HTTP_REQUEST_METHOD_GET; _clientHeaders = [[OFMutableDictionary alloc] initWithObject: @"OFHTTP" forKey: @"User-Agent"]; _HTTPClient = [[OFHTTPClient alloc] init]; [_HTTPClient setDelegate: self]; _buffer = [self allocMemoryWithSize: [OFSystemInfo pageSize]]; } @catch (id e) { [self release]; @throw e; } return self; } - (void)addHeader: (OFString*)header { size_t pos = [header rangeOfString: @":"].location; OFString *name, *value; if (pos == OF_NOT_FOUND) { [of_stderr writeString: OF_LOCALIZED(@"invalid_input_header", @"%[prog]: Headers must to be in format name:value!\n", @"prog", [OFApplication programName])]; [OFApplication terminateWithStatus: 1]; } name = [header substringWithRange: of_range(0, pos)]; name = [name stringByDeletingEnclosingWhitespaces]; value = [header substringWithRange: of_range(pos + 1, [header length] - pos - 1)]; value = [value stringByDeletingEnclosingWhitespaces]; [_clientHeaders setObject: value forKey: name]; } - (void)setBody: (OFString*)file { [_body release]; if ([file isEqual: @"-"]) { void *pool = objc_autoreleasePoolPush(); _body = [[of_stdin readDataArrayTillEndOfStream] retain]; objc_autoreleasePoolPop(pool); } else _body = [[OFDataArray alloc] initWithContentsOfFile: file]; } - (void)setMethod: (OFString*)method { void *pool = objc_autoreleasePoolPush(); method = [method uppercaseString]; if ([method isEqual: @"GET"]) _method = OF_HTTP_REQUEST_METHOD_GET; else if ([method isEqual: @"HEAD"]) _method = OF_HTTP_REQUEST_METHOD_HEAD; else if ([method isEqual: @"POST"]) _method = OF_HTTP_REQUEST_METHOD_POST; else if ([method isEqual: @"PUT"]) _method = OF_HTTP_REQUEST_METHOD_PUT; else if ([method isEqual: @"DELETE"]) _method = OF_HTTP_REQUEST_METHOD_DELETE; else if ([method isEqual: @"TRACE"]) _method = OF_HTTP_REQUEST_METHOD_TRACE; else { [of_stderr writeString: OF_LOCALIZED(@"invalid_input_method", @"%[prog]: Invalid request method %[method]!\n", @"prog", [OFApplication programName], @"method", method)]; [OFApplication terminateWithStatus: 1]; } objc_autoreleasePoolPop(pool); } - (void)setProxy: (OFString*)proxy { @try { size_t pos = [proxy rangeOfString: @":" options: OF_STRING_SEARCH_BACKWARDS].location; OFString *host; intmax_t port; if (pos == OF_NOT_FOUND) @throw [OFInvalidFormatException exception]; host = [proxy substringWithRange: of_range(0, pos)]; port = [[proxy substringWithRange: of_range(pos + 1, [proxy length] - pos - 1)] decimalValue]; if (port > UINT16_MAX) @throw [OFOutOfRangeException exception]; [OFTCPSocket setSOCKS5Host: host]; [OFTCPSocket setSOCKS5Port: (uint16_t)port]; } @catch (OFInvalidFormatException *e) { [of_stderr writeString: OF_LOCALIZED(@"invalid_input_proxy", @"%[prog]: Proxy must to be in format host:port!\n", @"prog", [OFApplication programName])]; [OFApplication terminateWithStatus: 1]; } } - (void)applicationDidFinishLaunching { OFString *outputPath; const of_options_parser_option_t options[] = { { 'b', @"body", 1, NULL, NULL }, { 'c', @"continue", 0, &_continue, NULL }, { 'f', @"force", 0, &_force, NULL }, { 'h', @"help", 0, NULL, NULL }, { 'H', @"header", 1, NULL, NULL }, { 'm', @"method", 1, NULL, NULL }, { 'o', @"output", 1, NULL, &outputPath }, { 'O', @"detect-filename", 0, &_detectFileName, NULL }, { 'P', @"socks5-proxy", 1, NULL, NULL }, { 'q', @"quiet", 0, &_quiet, NULL }, { 'v', @"verbose", 0, &_verbose, NULL }, { '\0', nil, 0, NULL, NULL } }; OFOptionsParser *optionsParser = [OFOptionsParser parserWithOptions: options]; of_unichar_t option; [OFLocalization addLanguageDirectory: @LANGUAGE_DIR]; while ((option = [optionsParser nextOption]) != '\0') { switch (option) { case 'b': [self setBody: [optionsParser argument]]; break; case 'h': help(of_stdout, true, 0); break; case 'H': [self addHeader: [optionsParser argument]]; break; case 'm': [self setMethod: [optionsParser argument]]; break; case 'P': [self setProxy: [optionsParser argument]]; break; case ':': if ([optionsParser lastLongOption] != nil) [of_stderr writeString: OF_LOCALIZED(@"long_argument_missing", @"%[prog]: Argument for option --%[opt] " "missing\n" @"prog", [OFApplication programName], @"opt", [optionsParser lastLongOption])]; else { OFString *optStr = [OFString stringWithFormat: @"%c", [optionsParser lastOption]]; [of_stderr writeString: OF_LOCALIZED(@"argument_missing", @"%[prog]: Argument for option -%[opt] " "missing\n", @"prog", [OFApplication programName], @"opt", optStr)]; } [OFApplication terminateWithStatus: 1]; break; case '=': [of_stderr writeString: OF_LOCALIZED(@"takes_no_argument", @"%[prog]: Option --%[opt] takes no argument\n", @"prog", [OFApplication programName], @"opt", [optionsParser lastLongOption])]; [OFApplication terminateWithStatus: 1]; break; case '?': if ([optionsParser lastLongOption] != nil) [of_stderr writeString: OF_LOCALIZED(@"unknown_long_option", @"%[prog]: Unknown option: --%[opt]\n", @"prog", [OFApplication programName], @"opt", [optionsParser lastLongOption])]; else { OFString *optStr = [OFString stringWithFormat: @"%c", [optionsParser lastOption]]; [of_stderr writeString: OF_LOCALIZED(@"unknown_option", @"%[prog]: Unknown option: -%[opt]\n", @"prog", [OFApplication programName], @"opt", optStr)]; } [OFApplication terminateWithStatus: 1]; break; } } _outputPath = [outputPath copy]; _URLs = [[optionsParser remainingArguments] retain]; if ([_URLs count] < 1) help(of_stderr, false, 1); if (_quiet && _verbose) { [of_stderr writeString: OF_LOCALIZED(@"quiet_xor_verbose", @"%[prog]: -q / --quiet and -v / --verbose are mutually " @"exclusive!\n", @"prog", [OFApplication programName])]; [OFApplication terminateWithStatus: 1]; } if (_outputPath != nil && [_URLs count] > 1) { [of_stderr writeString: OF_LOCALIZED(@"output_only_with_one_url", @"%[prog]: Cannot use -o / --output when more than one URL " @"has been specified!\n", @"prog", [OFApplication programName])]; [OFApplication terminateWithStatus: 1]; } [self performSelector: @selector(downloadNextURL) afterDelay: 0]; } - (bool)client: (OFHTTPClient*)client shouldFollowRedirect: (OFURL*)URL statusCode: (int)statusCode request: (OFHTTPRequest*)request response: (OFHTTPResponse*)response { if (!_quiet) [of_stdout writeFormat: @" ➜ %d\n", statusCode]; if (_verbose) { void *pool = objc_autoreleasePoolPush(); OFDictionary OF_GENERIC(OFString*, OFString*) *headers = [response headers]; OFEnumerator *keyEnumerator = [headers keyEnumerator]; OFEnumerator *objectEnumerator = [headers objectEnumerator]; OFString *key, *object; while ((key = [keyEnumerator nextObject]) != nil && (object = [objectEnumerator nextObject]) != nil) [of_stdout writeFormat: @" %@: %@\n", key, object]; objc_autoreleasePoolPop(pool); } if (!_quiet) [of_stdout writeFormat: @"☇ %@", [URL string]]; return true; } - (OFHTTPResponse*)performRequest: (OFHTTPRequest*)request { OFHTTPResponse *response = nil; @try { response = [_HTTPClient performRequest: request]; } @catch (OFAddressTranslationFailedException *e) { if (!_quiet) [of_stdout writeString: @"\n"]; [of_stderr writeString: OF_LOCALIZED(@"download_failed_address_translation", @"%[prog]: Failed to download <%[url]>!\n" @" Address translation failed: %[exception]\n", @"prog", [OFApplication programName], @"url", [[request URL] string], @"exception", e)]; } @catch (OFConnectionFailedException *e) { if (!_quiet) [of_stdout writeString: @"\n"]; [of_stderr writeString: OF_LOCALIZED(@"download_failed_connection_failed", @"%[prog]: Failed to download <%[url]>!\n" @" Connection failed: %[exception]\n", @"prog", [OFApplication programName], @"url", [[request URL] string], @"exception", e)]; } @catch (OFInvalidServerReplyException *e) { if (!_quiet) [of_stdout writeString: @"\n"]; [of_stderr writeString: OF_LOCALIZED(@"download_failed_invalid_server_reply", @"%[prog]: Failed to download <%[url]>!\n" @" Invalid server reply!\n", @"prog", [OFApplication programName], @"url", [[request URL] string])]; } @catch (OFUnsupportedProtocolException *e) { if (!_quiet) [of_stdout writeString: @"\n"]; [of_stderr writeString: OF_LOCALIZED(@"no_ssl_library", @"%[prog]: No SSL library loaded!\n" @" In order to download via https, you need to preload an " @"SSL library for ObjFW\n" "such as ObjOpenSSL!\n", @"prog", [OFApplication programName])]; } @catch (OFReadOrWriteFailedException *e) { OFString *error = OF_LOCALIZED( @"download_failed_read_or_write_failed_any", @"Read or write failed"); if (!_quiet) [of_stdout writeString: @"\n"]; if ([e isKindOfClass: [OFReadFailedException class]]) error = OF_LOCALIZED( @"download_failed_read_or_write_failed_read", @"Read failed"); else if ([e isKindOfClass: [OFWriteFailedException class]]) error = OF_LOCALIZED( @"download_failed_read_or_write_failed_write", @"Write failed"); [of_stderr writeString: OF_LOCALIZED(@"download_failed_read_or_write_failed", @"%[prog]: Failed to download <%[url]>!\n" @" %[error]: %[exception]\n", @"prog", [OFApplication programName], @"url", [[request URL] string], @"error", error, @"exception", e)]; } @catch (OFHTTPRequestFailedException *e) { if (!_quiet) [of_stdout writeFormat: @" ➜ %d\n", [[e response] statusCode]]; [of_stderr writeString: OF_LOCALIZED(@"download_failed", @"%[prog]: Failed to download <%[url]>!\n", @"prog", [OFApplication programName], @"url", [[request URL] string])]; } if (!_quiet && response != nil) [of_stdout writeFormat: @" ➜ %d\n", [response statusCode]]; return response; } - (OFString*)fileNameFromContentDisposition: (OFString*)contentDisposition { void *pool; const char *UTF8String; size_t UTF8StringLength; enum { DISPOSITION_TYPE, DISPOSITION_TYPE_SEMICOLON, DISPOSITION_PARAM_NAME_SKIP_SPACE, DISPOSITION_PARAM_NAME, DISPOSITION_PARAM_VALUE, DISPOSITION_PARAM_QUOTED, DISPOSITION_EXPECT_SEMICOLON } state; size_t last; OFString *type = nil, *paramName = nil, *paramValue; OFMutableDictionary *params; OFString *fileName; if (contentDisposition == nil) return nil; pool = objc_autoreleasePoolPush(); UTF8String = [contentDisposition UTF8String]; UTF8StringLength = [contentDisposition UTF8StringLength]; state = DISPOSITION_TYPE; params = [OFMutableDictionary dictionary]; last = 0; for (size_t i = 0; i < UTF8StringLength; i++) { switch (state) { case DISPOSITION_TYPE: if (UTF8String[i] == ';' || UTF8String[i] == ' ') { type = [OFString stringWithUTF8String: UTF8String length: i]; state = (UTF8String[i] == ';' ? DISPOSITION_PARAM_NAME_SKIP_SPACE : DISPOSITION_TYPE_SEMICOLON); last = i + 1; } break; case DISPOSITION_TYPE_SEMICOLON: if (UTF8String[i] == ';') { state = DISPOSITION_PARAM_NAME_SKIP_SPACE; last = i + 1; } else if (UTF8String[i] != ' ') { objc_autoreleasePoolPop(pool); return nil; } break; case DISPOSITION_PARAM_NAME_SKIP_SPACE: if (UTF8String[i] != ' ') { state = DISPOSITION_PARAM_NAME; last = i; i--; } break; case DISPOSITION_PARAM_NAME: if (UTF8String[i] == '=') { paramName = [OFString stringWithUTF8String: UTF8String + last length: i - last]; state = DISPOSITION_PARAM_VALUE; } break; case DISPOSITION_PARAM_VALUE: if (UTF8String[i] == '"') { state = DISPOSITION_PARAM_QUOTED; last = i + 1; } else { objc_autoreleasePoolPop(pool); return nil; } break; case DISPOSITION_PARAM_QUOTED: if (UTF8String[i] == '"') { paramValue = [OFString stringWithUTF8String: UTF8String + last length: i - last]; [params setObject: paramValue forKey: paramName]; state = DISPOSITION_EXPECT_SEMICOLON; } break; case DISPOSITION_EXPECT_SEMICOLON: if (UTF8String[i] == ';') { state = DISPOSITION_PARAM_NAME_SKIP_SPACE; last = i + 1; } else if (UTF8String[i] != ' ') { objc_autoreleasePoolPop(pool); return nil; } break; } } if (state != DISPOSITION_EXPECT_SEMICOLON) { objc_autoreleasePoolPop(pool); return nil; } if (![type isEqual: @"attachment"] || (fileName = [params objectForKey: @"filename"]) == nil) { objc_autoreleasePoolPop(pool); return nil; } fileName = [fileName lastPathComponent]; [fileName retain]; objc_autoreleasePoolPop(pool); return [fileName autorelease]; } - (bool)stream: (OFHTTPResponse*)response didReadIntoBuffer: (void*)buffer length: (size_t)length exception: (OFException*)e { if (e != nil) { OFString *URL; [_progressBar stop]; [_progressBar draw]; [_progressBar release]; _progressBar = nil; if (!_quiet) [of_stdout writeString: @"\n Error!\n"]; URL = [_URLs objectAtIndex: _URLIndex - 1]; [of_stderr writeString: OF_LOCALIZED(@"download_failed_exception", @"%[prog]: Failed to download <%[url]>: %[exception]\n", @"prog", [OFApplication programName], @"url", URL, @"exception", e)]; _errorCode = 1; goto next; } _received += length; [_output writeBuffer: buffer length: length]; [_progressBar setReceived: _received]; if ([response isAtEndOfStream] || (_length >= 0 && _received >= _length)) { [_progressBar stop]; [_progressBar draw]; [_progressBar release]; _progressBar = nil; if (!_quiet) [of_stdout writeString: OF_LOCALIZED(@"download_done", @"\n Done!\n")]; goto next; } return true; next: [self performSelector: @selector(downloadNextURL) afterDelay: 0]; return false; } - (void)downloadNextURL { OFFileManager *fileManager = [OFFileManager defaultManager]; OFString *URLString = nil; OFURL *URL; OFMutableDictionary *clientHeaders; OFHTTPRequest *request; OFHTTPResponse *response; OFDictionary OF_GENERIC(OFString*, OFString*) *headers; OFString *fileName = nil, *lengthString, *type; _length = -1; _received = _resumedFrom = 0; if (_output != of_stdout) [_output release]; _output = nil; if (_URLIndex >= [_URLs count]) [OFApplication terminateWithStatus: _errorCode]; @try { URLString = [_URLs objectAtIndex: _URLIndex++]; URL = [OFURL URLWithString: URLString]; } @catch (OFInvalidFormatException *e) { [of_stderr writeString: OF_LOCALIZED(@"invalid_url", @"%[prog]: Invalid URL: <%[url]>!\n", @"prog", [OFApplication programName], @"url", URLString)]; _errorCode = 1; goto next; } if (![[URL scheme] isEqual: @"http"] && ![[URL scheme] isEqual: @"https"]) { [of_stderr writeString: OF_LOCALIZED(@"invalid_scheme", @"%[prog]: Invalid scheme: <%[scheme]:>!\n", @"prog", [OFApplication programName], @"scheme", URLString)]; _errorCode = 1; goto next; } clientHeaders = [[_clientHeaders mutableCopy] autorelease]; if (_detectFileName) { if (!_quiet) [of_stdout writeFormat: @"⠒ %@", [URL string]]; request = [OFHTTPRequest requestWithURL: URL]; [request setHeaders: clientHeaders]; [request setMethod: OF_HTTP_REQUEST_METHOD_HEAD]; if ((response = [self performRequest: request]) == nil) { _errorCode = 1; goto next; } fileName = [self fileNameFromContentDisposition: [[response headers] objectForKey: @"Content-Disposition"]]; } if (!_quiet) [of_stdout writeFormat: @"⇣ %@", [URL string]]; if (_outputPath != nil) fileName = _outputPath; if (fileName == nil) fileName = [[URL path] lastPathComponent]; if (_continue) { @try { of_offset_t size = [fileManager sizeOfFileAtPath: fileName]; OFString *range; if (size > INTMAX_MAX) @throw [OFOutOfRangeException exception]; _resumedFrom = (intmax_t)size; range = [OFString stringWithFormat: @"bytes=%jd-", _resumedFrom]; [clientHeaders setObject: range forKey: @"Range"]; } @catch (OFStatItemFailedException *e) { } } request = [OFHTTPRequest requestWithURL: URL]; [request setHeaders: clientHeaders]; [request setMethod: _method]; [request setBody: _body]; if ((response = [self performRequest: request]) == nil) { _errorCode = 1; goto next; } headers = [response headers]; lengthString = [headers objectForKey: @"Content-Length"]; type = [headers objectForKey: @"Content-Type"]; if (lengthString != nil) _length = [lengthString decimalValue]; if (!_quiet) { if (type == nil) type = OF_LOCALIZED(@"type_unknown", @"unknown"); if (_length >= 0) { if (_resumedFrom + _length >= GIBIBYTE) { lengthString = [OFString stringWithFormat: @"%,.2f", (float)(_resumedFrom + _length) / GIBIBYTE]; lengthString = OF_LOCALIZED(@"size_gib", @"%[num] GiB", @"num", lengthString); } else if (_resumedFrom + _length >= MEBIBYTE) { lengthString = [OFString stringWithFormat: @"%,.2f", (float)(_resumedFrom + _length) / MEBIBYTE]; lengthString = OF_LOCALIZED(@"size_mib", @"%[num] MiB", @"num", lengthString); } else if (_resumedFrom + _length >= KIBIBYTE) { lengthString = [OFString stringWithFormat: @"%,.2f", (float)(_resumedFrom + _length) / KIBIBYTE]; lengthString = OF_LOCALIZED(@"size_kib", @"%[num] KiB", @"num", lengthString); } else { lengthString = [OFString stringWithFormat: @"%jd", _resumedFrom + _length]; lengthString = OF_LOCALIZED(@"size_bytes", @"%[num] bytes", @"num", lengthString); } } else lengthString = OF_LOCALIZED(@"size_unknown", @"unknown"); if (_verbose) { void *pool = objc_autoreleasePoolPush(); OFDictionary OF_GENERIC(OFString*, OFString*) *headers = [response headers]; OFEnumerator *keyEnumerator = [headers keyEnumerator]; OFEnumerator *objectEnumerator = [headers objectEnumerator]; OFString *key, *object; [of_stdout writeString: OF_LOCALIZED(@"info_name_nopad", @" Name: %[name]\n", @"name", fileName)]; while ((key = [keyEnumerator nextObject]) != nil && (object = [objectEnumerator nextObject]) != nil) [of_stdout writeFormat: @" %@: %@\n", key, object]; objc_autoreleasePoolPop(pool); } else { [of_stdout writeString: OF_LOCALIZED(@"info_name", @" Name: %[name]\n", @"name", fileName)]; [of_stdout writeString: OF_LOCALIZED(@"info_type", @" Type: %[type]\n", @"type", type)]; [of_stdout writeString: OF_LOCALIZED(@"info_size", @" Size: %[size]\n", @"size", lengthString)]; } } if ([_outputPath isEqual: @"-"]) _output = of_stdout; else { if (!_continue && !_force && [fileManager fileExistsAtPath: fileName]) { [of_stderr writeString: OF_LOCALIZED(@"ouput_already_exists", @"%[prog]: File %[filename] already exists!\n", @"prog", [OFApplication programName], @"filename", fileName)]; _errorCode = 1; goto next; } @try { OFString *mode = ([response statusCode] == 206 ? @"ab" : @"wb"); _output = [[OFFile alloc] initWithPath: fileName mode: mode]; } @catch (OFOpenItemFailedException *e) { [of_stderr writeString: OF_LOCALIZED(@"failed_to_open_output", @"%[prog]: Failed to open file %[filename]: " @"%[exception]\n", @"prog", [OFApplication programName], @"filename",fileName, @"exception", e)]; _errorCode = 1; goto next; } } if (!_quiet) { _progressBar = [[ProgressBar alloc] initWithLength: _length resumedFrom: _resumedFrom]; [_progressBar setReceived: _received]; [_progressBar draw]; } [response asyncReadIntoBuffer: _buffer length: [OFSystemInfo pageSize] target: self selector: @selector(stream:didReadIntoBuffer: length:exception:)]; return; next: [self performSelector: @selector(downloadNextURL) afterDelay: 0]; } @end