urllib.py
| 58.8 KB | Satir:
0
| py
Geri
"""Open an arbitrary URL. See the following document for more info on URLs: "Names and Addresses, URIs, URLs, URNs, URCs", at http://www.w3.org/pub/WWW/Addressing/Overview.html See also the HTTP spec (from which the error codes are derived): "HTTP - Hypertext Transfer Protocol", at http://www.w3.org/pub/WWW/Protocols/ Related standards and specs: - RFC1808: the "relative URL" spec. (authoritative status) - RFC1738 - the "URL standard". (authoritative status) - RFC1630 - the "URI spec". (informational status) The object returned by URLopener().open(file) will differ per protocol. All you know is that is has methods read(), readline(), readlines(), fileno(), close() and info(). The read*(), fileno() and close() methods work like those of open files. The info() method returns a mimetools.Message object which can be used to query various info about the object, if available. (mimetools.Message objects are queried with the getheader() method.) """ import string import socket import os import time import sys import base64 import re from urlparse import urljoin as basejoin __all__ = ["urlopen", "URLopener", "FancyURLopener", "urlretrieve", "urlcleanup", "quote", "quote_plus", "unquote", "unquote_plus", "urlencode", "url2pathname", "pathname2url", "splittag", "localhost", "thishost", "ftperrors", "basejoin", "unwrap", "splittype", "splithost", "splituser", "splitpasswd", "splitport", "splitnport", "splitquery", "splitattr", "splitvalue", "getproxies"] __version__ = '1.17' # XXX This version is not always updated :-( MAXFTPCACHE = 10 # Trim the ftp cache beyond this size # Helper for non-unix systems if os.name == 'nt': from nturl2path import url2pathname, pathname2url elif os.name == 'riscos': from rourl2path import url2pathname, pathname2url else: def url2pathname(pathname): """OS-specific conversion from a relative URL of the 'file' scheme to a file system path; not recommended for general use.""" return unquote(pathname) def pathname2url(pathname): """OS-specific conversion from a file system path to a relative URL of the 'file' scheme; not recommended for general use.""" return quote(pathname) # This really consists of two pieces: # (1) a class which handles opening of all sorts of URLs # (plus assorted utilities etc.) # (2) a set of functions for parsing URLs # XXX Should these be separated out into different modules? # Shortcut for basic usage _urlopener = None def urlopen(url, data=None, proxies=None, context=None): """Create a file-like object for the specified URL to read from.""" from warnings import warnpy3k warnpy3k("urllib.urlopen() has been removed in Python 3.0 in " "favor of urllib2.urlopen()", stacklevel=2) global _urlopener if proxies is not None or context is not None: opener = FancyURLopener(proxies=proxies, context=context) elif not _urlopener: opener = FancyURLopener() _urlopener = opener else: opener = _urlopener if data is None: return opener.open(url) else: return opener.open(url, data) def urlretrieve(url, filename=None, reporthook=None, data=None, context=None): global _urlopener if context is not None: opener = FancyURLopener(context=context) elif not _urlopener: _urlopener = opener = FancyURLopener() else: opener = _urlopener return opener.retrieve(url, filename, reporthook, data) def urlcleanup(): if _urlopener: _urlopener.cleanup() _safe_quoters.clear() ftpcache.clear() # check for SSL try: import ssl except: _have_ssl = False else: _have_ssl = True # exception raised when downloaded size does not match content-length class ContentTooShortError(IOError): def __init__(self, message, content): IOError.__init__(self, message) self.content = content ftpcache = {} class URLopener: """Class to open URLs. This is a class rather than just a subroutine because we may need more than one set of global protocol-specific options. Note -- this is a base class for those who don't want the automatic handling of errors type 302 (relocated) and 401 (authorization needed).""" __tempfiles = None version = "Python-urllib/%s" % __version__ # Constructor def __init__(self, proxies=None, context=None, **x509): if proxies is None: proxies = getproxies() assert hasattr(proxies, 'has_key'), "proxies must be a mapping" self.proxies = proxies self.key_file = x509.get('key_file') self.cert_file = x509.get('cert_file') self.context = context self.addheaders = [('User-Agent', self.version), ('Accept', '*/*')] self.__tempfiles = [] self.__unlink = os.unlink # See cleanup() self.tempcache = None # Undocumented feature: if you assign {} to tempcache, # it is used to cache files retrieved with # self.retrieve(). This is not enabled by default # since it does not work for changing documents (and I # haven't got the logic to check expiration headers # yet). self.ftpcache = ftpcache # Undocumented feature: you can use a different # ftp cache by assigning to the .ftpcache member; # in case you want logically independent URL openers # XXX This is not threadsafe. Bah. def __del__(self): self.close() def close(self): self.cleanup() def cleanup(self): # This code sometimes runs when the rest of this module # has already been deleted, so it can't use any globals # or import anything. if self.__tempfiles: for file in self.__tempfiles: try: self.__unlink(file) except OSError: pass del self.__tempfiles[:] if self.tempcache: self.tempcache.clear() def addheader(self, *args): """Add a header to be used by the HTTP interface only e.g. u.addheader('Accept', 'sound/basic')""" self.addheaders.append(args) # External interface def open(self, fullurl, data=None): """Use URLopener().open(file) instead of open(file, 'r').""" fullurl = unwrap(toBytes(fullurl)) # percent encode url, fixing lame server errors for e.g, like space # within url paths. fullurl = quote(fullurl, safe="%/:=&?~#+!$,;'@()*[]|") if self.tempcache and fullurl in self.tempcache: filename, headers = self.tempcache[fullurl] fp = open(filename, 'rb') return addinfourl(fp, headers, fullurl) urltype, url = splittype(fullurl) if not urltype: urltype = 'file' if urltype in self.proxies: proxy = self.proxies[urltype] urltype, proxyhost = splittype(proxy) host, selector = splithost(proxyhost) url = (host, fullurl) # Signal special case to open_*() else: proxy = None name = 'open_' + urltype self.type = urltype name = name.replace('-', '_') # bpo-35907: disallow the file reading with the type not allowed if not hasattr(self, name) or name == 'open_local_file': if proxy: return self.open_unknown_proxy(proxy, fullurl, data) else: return self.open_unknown(fullurl, data) try: if data is None: return getattr(self, name)(url) else: return getattr(self, name)(url, data) except socket.error, msg: raise IOError, ('socket error', msg), sys.exc_info()[2] def open_unknown(self, fullurl, data=None): """Overridable interface to open unknown URL type.""" type, url = splittype(fullurl) raise IOError, ('url error', 'unknown url type', type) def open_unknown_proxy(self, proxy, fullurl, data=None): """Overridable interface to open unknown URL type.""" type, url = splittype(fullurl) raise IOError, ('url error', 'invalid proxy for %s' % type, proxy) # External interface def retrieve(self, url, filename=None, reporthook=None, data=None): """retrieve(url) returns (filename, headers) for a local object or (tempfilename, headers) for a remote object.""" url = unwrap(toBytes(url)) if self.tempcache and url in self.tempcache: return self.tempcache[url] type, url1 = splittype(url) if filename is None and (not type or type == 'file'): try: fp = self.open_local_file(url1) hdrs = fp.info() fp.close() return url2pathname(splithost(url1)[1]), hdrs except IOError: pass fp = self.open(url, data) try: headers = fp.info() if filename: tfp = open(filename, 'wb') else: import tempfile garbage, path = splittype(url) garbage, path = splithost(path or "") path, garbage = splitquery(path or "") path, garbage = splitattr(path or "") suffix = os.path.splitext(path)[1] (fd, filename) = tempfile.mkstemp(suffix) self.__tempfiles.append(filename) tfp = os.fdopen(fd, 'wb') try: result = filename, headers if self.tempcache is not None: self.tempcache[url] = result bs = 1024*8 size = -1 read = 0 blocknum = 0 if "content-length" in headers: size = int(headers["Content-Length"]) if reporthook: reporthook(blocknum, bs, size) while 1: block = fp.read(bs) if block == "": break read += len(block) tfp.write(block) blocknum += 1 if reporthook: reporthook(blocknum, bs, size) finally: tfp.close() finally: fp.close() # raise exception if actual size does not match content-length header if size >= 0 and read < size: raise ContentTooShortError("retrieval incomplete: got only %i out " "of %i bytes" % (read, size), result) return result # Each method named open_<type> knows how to open that type of URL def open_http(self, url, data=None): """Use HTTP protocol.""" import httplib user_passwd = None proxy_passwd= None if isinstance(url, str): host, selector = splithost(url) if host: user_passwd, host = splituser(host) host = unquote(host) realhost = host else: host, selector = url # check whether the proxy contains authorization information proxy_passwd, host = splituser(host) # now we proceed with the url we want to obtain urltype, rest = splittype(selector) url = rest user_passwd = None if urltype.lower() != 'http': realhost = None else: realhost, rest = splithost(rest) if realhost: user_passwd, realhost = splituser(realhost) if user_passwd: selector = "%s://%s%s" % (urltype, realhost, rest) if proxy_bypass(realhost): host = realhost #print "proxy via http:", host, selector if not host: raise IOError, ('http error', 'no host given') if proxy_passwd: proxy_passwd = unquote(proxy_passwd) proxy_auth = base64.b64encode(proxy_passwd).strip() else: proxy_auth = None if user_passwd: user_passwd = unquote(user_passwd) auth = base64.b64encode(user_passwd).strip() else: auth = None h = httplib.HTTP(host) if data is not None: h.putrequest('POST', selector) h.putheader('Content-Type', 'application/x-www-form-urlencoded') h.putheader('Content-Length', '%d' % len(data)) else: h.putrequest('GET', selector) if proxy_auth: h.putheader('Proxy-Authorization', 'Basic %s' % proxy_auth) if auth: h.putheader('Authorization', 'Basic %s' % auth) if realhost: h.putheader('Host', realhost) for args in self.addheaders: h.putheader(*args) h.endheaders(data) errcode, errmsg, headers = h.getreply() fp = h.getfile() if errcode == -1: if fp: fp.close() # something went wrong with the HTTP status line raise IOError, ('http protocol error', 0, 'got a bad status line', None) # According to RFC 2616, "2xx" code indicates that the client's # request was successfully received, understood, and accepted. if (200 <= errcode < 300): return addinfourl(fp, headers, "http:" + url, errcode) else: if data is None: return self.http_error(url, fp, errcode, errmsg, headers) else: return self.http_error(url, fp, errcode, errmsg, headers, data) def http_error(self, url, fp, errcode, errmsg, headers, data=None): """Handle http errors. Derived class can override this, or provide specific handlers named http_error_DDD where DDD is the 3-digit error code.""" # First check if there's a specific handler for this error name = 'http_error_%d' % errcode if hasattr(self, name): method = getattr(self, name) if data is None: result = method(url, fp, errcode, errmsg, headers) else: result = method(url, fp, errcode, errmsg, headers, data) if result: return result return self.http_error_default(url, fp, errcode, errmsg, headers) def http_error_default(self, url, fp, errcode, errmsg, headers): """Default error handler: close the connection and raise IOError.""" fp.close() raise IOError, ('http error', errcode, errmsg, headers) if _have_ssl: def open_https(self, url, data=None): """Use HTTPS protocol.""" import httplib user_passwd = None proxy_passwd = None if isinstance(url, str): host, selector = splithost(url) if host: user_passwd, host = splituser(host) host = unquote(host) realhost = host else: host, selector = url # here, we determine, whether the proxy contains authorization information proxy_passwd, host = splituser(host) urltype, rest = splittype(selector) url = rest user_passwd = None if urltype.lower() != 'https': realhost = None else: realhost, rest = splithost(rest) if realhost: user_passwd, realhost = splituser(realhost) if user_passwd: selector = "%s://%s%s" % (urltype, realhost, rest) #print "proxy via https:", host, selector if not host: raise IOError, ('https error', 'no host given') if proxy_passwd: proxy_passwd = unquote(proxy_passwd) proxy_auth = base64.b64encode(proxy_passwd).strip() else: proxy_auth = None if user_passwd: user_passwd = unquote(user_passwd) auth = base64.b64encode(user_passwd).strip() else: auth = None h = httplib.HTTPS(host, 0, key_file=self.key_file, cert_file=self.cert_file, context=self.context) if data is not None: h.putrequest('POST', selector) h.putheader('Content-Type', 'application/x-www-form-urlencoded') h.putheader('Content-Length', '%d' % len(data)) else: h.putrequest('GET', selector) if proxy_auth: h.putheader('Proxy-Authorization', 'Basic %s' % proxy_auth) if auth: h.putheader('Authorization', 'Basic %s' % auth) if realhost: h.putheader('Host', realhost) for args in self.addheaders: h.putheader(*args) h.endheaders(data) errcode, errmsg, headers = h.getreply() fp = h.getfile() if errcode == -1: if fp: fp.close() # something went wrong with the HTTP status line raise IOError, ('http protocol error', 0, 'got a bad status line', None) # According to RFC 2616, "2xx" code indicates that the client's # request was successfully received, understood, and accepted. if (200 <= errcode < 300): return addinfourl(fp, headers, "https:" + url, errcode) else: if data is None: return self.http_error(url, fp, errcode, errmsg, headers) else: return self.http_error(url, fp, errcode, errmsg, headers, data) def open_file(self, url): """Use local file or FTP depending on form of URL.""" if not isinstance(url, str): raise IOError, ('file error', 'proxy support for file protocol currently not implemented') if url[:2] == '//' and url[2:3] != '/' and url[2:12].lower() != 'localhost/': return self.open_ftp(url) else: return self.open_local_file(url) def open_local_file(self, url): """Use local file.""" import mimetypes, mimetools, email.utils try: from cStringIO import StringIO except ImportError: from StringIO import StringIO host, file = splithost(url) localname = url2pathname(file) try: stats = os.stat(localname) except OSError, e: raise IOError(e.errno, e.strerror, e.filename) size = stats.st_size modified = email.utils.formatdate(stats.st_mtime, usegmt=True) mtype = mimetypes.guess_type(url)[0] headers = mimetools.Message(StringIO( 'Content-Type: %s\nContent-Length: %d\nLast-modified: %s\n' % (mtype or 'text/plain', size, modified))) if not host: urlfile = file if file[:1] == '/': urlfile = 'file://' + file elif file[:2] == './': raise ValueError("local file url may start with / or file:. Unknown url of type: %s" % url) return addinfourl(open(localname, 'rb'), headers, urlfile) host, port = splitport(host) if not port \ and socket.gethostbyname(host) in (localhost(), thishost()): urlfile = file if file[:1] == '/': urlfile = 'file://' + file return addinfourl(open(localname, 'rb'), headers, urlfile) raise IOError, ('local file error', 'not on local host') def open_ftp(self, url): """Use FTP protocol.""" if not isinstance(url, str): raise IOError, ('ftp error', 'proxy support for ftp protocol currently not implemented') import mimetypes, mimetools try: from cStringIO import StringIO except ImportError: from StringIO import StringIO host, path = splithost(url) if not host: raise IOError, ('ftp error', 'no host given') host, port = splitport(host) user, host = splituser(host) if user: user, passwd = splitpasswd(user) else: passwd = None host = unquote(host) user = user or '' passwd = passwd or '' host = socket.gethostbyname(host) if not port: import ftplib port = ftplib.FTP_PORT else: port = int(port) path, attrs = splitattr(path) path = unquote(path) dirs = path.split('/') dirs, file = dirs[:-1], dirs[-1] if dirs and not dirs[0]: dirs = dirs[1:] if dirs and not dirs[0]: dirs[0] = '/' key = user, host, port, '/'.join(dirs) # XXX thread unsafe! if len(self.ftpcache) > MAXFTPCACHE: # Prune the cache, rather arbitrarily for k in self.ftpcache.keys(): if k != key: v = self.ftpcache[k] del self.ftpcache[k] v.close() try: if not key in self.ftpcache: self.ftpcache[key] = \ ftpwrapper(user, passwd, host, port, dirs) if not file: type = 'D' else: type = 'I' for attr in attrs: attr, value = splitvalue(attr) if attr.lower() == 'type' and \ value in ('a', 'A', 'i', 'I', 'd', 'D'): type = value.upper() (fp, retrlen) = self.ftpcache[key].retrfile(file, type) mtype = mimetypes.guess_type("ftp:" + url)[0] headers = "" if mtype: headers += "Content-Type: %s\n" % mtype if retrlen is not None and retrlen >= 0: headers += "Content-Length: %d\n" % retrlen headers = mimetools.Message(StringIO(headers)) return addinfourl(fp, headers, "ftp:" + url) except ftperrors(), msg: raise IOError, ('ftp error', msg), sys.exc_info()[2] def open_data(self, url, data=None): """Use "data" URL.""" if not isinstance(url, str): raise IOError, ('data error', 'proxy support for data protocol currently not implemented') # ignore POSTed data # # syntax of data URLs: # dataurl := "data:" [ mediatype ] [ ";base64" ] "," data # mediatype := [ type "/" subtype ] *( ";" parameter ) # data := *urlchar # parameter := attribute "=" value import mimetools try: from cStringIO import StringIO except ImportError: from StringIO import StringIO try: [type, data] = url.split(',', 1) except ValueError: raise IOError, ('data error', 'bad data URL') if not type: type = 'text/plain;charset=US-ASCII' semi = type.rfind(';') if semi >= 0 and '=' not in type[semi:]: encoding = type[semi+1:] type = type[:semi] else: encoding = '' msg = [] msg.append('Date: %s'%time.strftime('%a, %d %b %Y %H:%M:%S GMT', time.gmtime(time.time()))) msg.append('Content-type: %s' % type) if encoding == 'base64': data = base64.decodestring(data) else: data = unquote(data) msg.append('Content-Length: %d' % len(data)) msg.append('') msg.append(data) msg = '\n'.join(msg) f = StringIO(msg) headers = mimetools.Message(f, 0) #f.fileno = None # needed for addinfourl return addinfourl(f, headers, url) class FancyURLopener(URLopener): """Derived class with handlers for errors we can handle (perhaps).""" def __init__(self, *args, **kwargs): URLopener.__init__(self, *args, **kwargs) self.auth_cache = {} self.tries = 0 self.maxtries = 10 def http_error_default(self, url, fp, errcode, errmsg, headers): """Default error handling -- don't raise an exception.""" return addinfourl(fp, headers, "http:" + url, errcode) def http_error_302(self, url, fp, errcode, errmsg, headers, data=None): """Error 302 -- relocated (temporarily).""" self.tries += 1 try: if self.maxtries and self.tries >= self.maxtries: if hasattr(self, "http_error_500"): meth = self.http_error_500 else: meth = self.http_error_default return meth(url, fp, 500, "Internal Server Error: Redirect Recursion", headers) result = self.redirect_internal(url, fp, errcode, errmsg, headers, data) return result finally: self.tries = 0 def redirect_internal(self, url, fp, errcode, errmsg, headers, data): if 'location' in headers: newurl = headers['location'] elif 'uri' in headers: newurl = headers['uri'] else: return fp.close() # In case the server sent a relative URL, join with original: newurl = basejoin(self.type + ":" + url, newurl) # For security reasons we do not allow redirects to protocols # other than HTTP, HTTPS or FTP. newurl_lower = newurl.lower() if not (newurl_lower.startswith('http://') or newurl_lower.startswith('https://') or newurl_lower.startswith('ftp://')): raise IOError('redirect error', errcode, errmsg + " - Redirection to url '%s' is not allowed" % newurl, headers) return self.open(newurl) def http_error_301(self, url, fp, errcode, errmsg, headers, data=None): """Error 301 -- also relocated (permanently).""" return self.http_error_302(url, fp, errcode, errmsg, headers, data) def http_error_303(self, url, fp, errcode, errmsg, headers, data=None): """Error 303 -- also relocated (essentially identical to 302).""" return self.http_error_302(url, fp, errcode, errmsg, headers, data) def http_error_307(self, url, fp, errcode, errmsg, headers, data=None): """Error 307 -- relocated, but turn POST into error.""" if data is None: return self.http_error_302(url, fp, errcode, errmsg, headers, data) else: return self.http_error_default(url, fp, errcode, errmsg, headers) def http_error_401(self, url, fp, errcode, errmsg, headers, data=None): """Error 401 -- authentication required. This function supports Basic authentication only.""" if not 'www-authenticate' in headers: URLopener.http_error_default(self, url, fp, errcode, errmsg, headers) stuff = headers['www-authenticate'] import re match = re.match('[ \t]*([^ \t]+)[ \t]+realm="([^"]*)"', stuff) if not match: URLopener.http_error_default(self, url, fp, errcode, errmsg, headers) scheme, realm = match.groups() if scheme.lower() != 'basic': URLopener.http_error_default(self, url, fp, errcode, errmsg, headers) name = 'retry_' + self.type + '_basic_auth' if data is None: return getattr(self,name)(url, realm) else: return getattr(self,name)(url, realm, data) def http_error_407(self, url, fp, errcode, errmsg, headers, data=None): """Error 407 -- proxy authentication required. This function supports Basic authentication only.""" if not 'proxy-authenticate' in headers: URLopener.http_error_default(self, url, fp, errcode, errmsg, headers) stuff = headers['proxy-authenticate'] import re match = re.match('[ \t]*([^ \t]+)[ \t]+realm="([^"]*)"', stuff) if not match: URLopener.http_error_default(self, url, fp, errcode, errmsg, headers) scheme, realm = match.groups() if scheme.lower() != 'basic': URLopener.http_error_default(self, url, fp, errcode, errmsg, headers) name = 'retry_proxy_' + self.type + '_basic_auth' if data is None: return getattr(self,name)(url, realm) else: return getattr(self,name)(url, realm, data) def retry_proxy_http_basic_auth(self, url, realm, data=None): host, selector = splithost(url) newurl = 'http://' + host + selector proxy = self.proxies['http'] urltype, proxyhost = splittype(proxy) proxyhost, proxyselector = splithost(proxyhost) i = proxyhost.find('@') + 1 proxyhost = proxyhost[i:] user, passwd = self.get_user_passwd(proxyhost, realm, i) if not (user or passwd): return None proxyhost = quote(user, safe='') + ':' + quote(passwd, safe='') + '@' + proxyhost self.proxies['http'] = 'http://' + proxyhost + proxyselector if data is None: return self.open(newurl) else: return self.open(newurl, data) def retry_proxy_https_basic_auth(self, url, realm, data=None): host, selector = splithost(url) newurl = 'https://' + host + selector proxy = self.proxies['https'] urltype, proxyhost = splittype(proxy) proxyhost, proxyselector = splithost(proxyhost) i = proxyhost.find('@') + 1 proxyhost = proxyhost[i:] user, passwd = self.get_user_passwd(proxyhost, realm, i) if not (user or passwd): return None proxyhost = quote(user, safe='') + ':' + quote(passwd, safe='') + '@' + proxyhost self.proxies['https'] = 'https://' + proxyhost + proxyselector if data is None: return self.open(newurl) else: return self.open(newurl, data) def retry_http_basic_auth(self, url, realm, data=None): host, selector = splithost(url) i = host.find('@') + 1 host = host[i:] user, passwd = self.get_user_passwd(host, realm, i) if not (user or passwd): return None host = quote(user, safe='') + ':' + quote(passwd, safe='') + '@' + host newurl = 'http://' + host + selector if data is None: return self.open(newurl) else: return self.open(newurl, data) def retry_https_basic_auth(self, url, realm, data=None): host, selector = splithost(url) i = host.find('@') + 1 host = host[i:] user, passwd = self.get_user_passwd(host, realm, i) if not (user or passwd): return None host = quote(user, safe='') + ':' + quote(passwd, safe='') + '@' + host newurl = 'https://' + host + selector if data is None: return self.open(newurl) else: return self.open(newurl, data) def get_user_passwd(self, host, realm, clear_cache=0): key = realm + '@' + host.lower() if key in self.auth_cache: if clear_cache: del self.auth_cache[key] else: return self.auth_cache[key] user, passwd = self.prompt_user_passwd(host, realm) if user or passwd: self.auth_cache[key] = (user, passwd) return user, passwd def prompt_user_passwd(self, host, realm): """Override this in a GUI environment!""" import getpass try: user = raw_input("Enter username for %s at %s: " % (realm, host)) passwd = getpass.getpass("Enter password for %s in %s at %s: " % (user, realm, host)) return user, passwd except KeyboardInterrupt: print return None, None # Utility functions _localhost = None def localhost(): """Return the IP address of the magic hostname 'localhost'.""" global _localhost if _localhost is None: _localhost = socket.gethostbyname('localhost') return _localhost _thishost = None def thishost(): """Return the IP address of the current host.""" global _thishost if _thishost is None: try: _thishost = socket.gethostbyname(socket.gethostname()) except socket.gaierror: _thishost = socket.gethostbyname('localhost') return _thishost _ftperrors = None def ftperrors(): """Return the set of errors raised by the FTP class.""" global _ftperrors if _ftperrors is None: import ftplib _ftperrors = ftplib.all_errors return _ftperrors _noheaders = None def noheaders(): """Return an empty mimetools.Message object.""" global _noheaders if _noheaders is None: import mimetools try: from cStringIO import StringIO except ImportError: from StringIO import StringIO _noheaders = mimetools.Message(StringIO(), 0) _noheaders.fp.close() # Recycle file descriptor return _noheaders # Utility classes class ftpwrapper: """Class used by open_ftp() for cache of open FTP connections.""" def __init__(self, user, passwd, host, port, dirs, timeout=socket._GLOBAL_DEFAULT_TIMEOUT, persistent=True): self.user = user self.passwd = passwd self.host = host self.port = port self.dirs = dirs self.timeout = timeout self.refcount = 0 self.keepalive = persistent try: self.init() except: self.close() raise def init(self): import ftplib self.busy = 0 self.ftp = ftplib.FTP() self.ftp.connect(self.host, self.port, self.timeout) self.ftp.login(self.user, self.passwd) _target = '/'.join(self.dirs) self.ftp.cwd(_target) def retrfile(self, file, type): import ftplib self.endtransfer() if type in ('d', 'D'): cmd = 'TYPE A'; isdir = 1 else: cmd = 'TYPE ' + type; isdir = 0 try: self.ftp.voidcmd(cmd) except ftplib.all_errors: self.init() self.ftp.voidcmd(cmd) conn = None if file and not isdir: # Try to retrieve as a file try: cmd = 'RETR ' + file conn, retrlen = self.ftp.ntransfercmd(cmd) except ftplib.error_perm, reason: if str(reason)[:3] != '550': raise IOError, ('ftp error', reason), sys.exc_info()[2] if not conn: # Set transfer mode to ASCII! self.ftp.voidcmd('TYPE A') # Try a directory listing. Verify that directory exists. if file: pwd = self.ftp.pwd() try: try: self.ftp.cwd(file) except ftplib.error_perm, reason: raise IOError, ('ftp error', reason), sys.exc_info()[2] finally: self.ftp.cwd(pwd) cmd = 'LIST ' + file else: cmd = 'LIST' conn, retrlen = self.ftp.ntransfercmd(cmd) self.busy = 1 ftpobj = addclosehook(conn.makefile('rb'), self.file_close) self.refcount += 1 conn.close() # Pass back both a suitably decorated object and a retrieval length return (ftpobj, retrlen) def endtransfer(self): if not self.busy: return self.busy = 0 try: self.ftp.voidresp() except ftperrors(): pass def close(self): self.keepalive = False if self.refcount <= 0: self.real_close() def file_close(self): self.endtransfer() self.refcount -= 1 if self.refcount <= 0 and not self.keepalive: self.real_close() def real_close(self): self.endtransfer() try: self.ftp.close() except ftperrors(): pass class addbase: """Base class for addinfo and addclosehook.""" def __init__(self, fp): self.fp = fp self.read = self.fp.read self.readline = self.fp.readline if hasattr(self.fp, "readlines"): self.readlines = self.fp.readlines if hasattr(self.fp, "fileno"): self.fileno = self.fp.fileno else: self.fileno = lambda: None if hasattr(self.fp, "__iter__"): self.__iter__ = self.fp.__iter__ if hasattr(self.fp, "next"): self.next = self.fp.next def __repr__(self): return '<%s at %r whose fp = %r>' % (self.__class__.__name__, id(self), self.fp) def close(self): self.read = None self.readline = None self.readlines = None self.fileno = None if self.fp: self.fp.close() self.fp = None class addclosehook(addbase): """Class to add a close hook to an open file.""" def __init__(self, fp, closehook, *hookargs): addbase.__init__(self, fp) self.closehook = closehook self.hookargs = hookargs def close(self): try: closehook = self.closehook hookargs = self.hookargs if closehook: self.closehook = None self.hookargs = None closehook(*hookargs) finally: addbase.close(self) class addinfo(addbase): """class to add an info() method to an open file.""" def __init__(self, fp, headers): addbase.__init__(self, fp) self.headers = headers def info(self): return self.headers class addinfourl(addbase): """class to add info() and geturl() methods to an open file.""" def __init__(self, fp, headers, url, code=None): addbase.__init__(self, fp) self.headers = headers self.url = url self.code = code def info(self): return self.headers def getcode(self): return self.code def geturl(self): return self.url # Utilities to parse URLs (most of these return None for missing parts): # unwrap('<URL:type://host/path>') --> 'type://host/path' # splittype('type:opaquestring') --> 'type', 'opaquestring' # splithost('//host[:port]/path') --> 'host[:port]', '/path' # splituser('user[:passwd]@host[:port]') --> 'user[:passwd]', 'host[:port]' # splitpasswd('user:passwd') -> 'user', 'passwd' # splitport('host:port') --> 'host', 'port' # splitquery('/path?query') --> '/path', 'query' # splittag('/path#tag') --> '/path', 'tag' # splitattr('/path;attr1=value1;attr2=value2;...') -> # '/path', ['attr1=value1', 'attr2=value2', ...] # splitvalue('attr=value') --> 'attr', 'value' # unquote('abc%20def') -> 'abc def' # quote('abc def') -> 'abc%20def') try: unicode except NameError: def _is_unicode(x): return 0 else: def _is_unicode(x): return isinstance(x, unicode) def toBytes(url): """toBytes(u"URL") --> 'URL'.""" # Most URL schemes require ASCII. If that changes, the conversion # can be relaxed if _is_unicode(url): try: url = url.encode("ASCII") except UnicodeError: raise UnicodeError("URL " + repr(url) + " contains non-ASCII characters") return url def unwrap(url): """unwrap('<URL:type://host/path>') --> 'type://host/path'.""" url = url.strip() if url[:1] == '<' and url[-1:] == '>': url = url[1:-1].strip() if url[:4] == 'URL:': url = url[4:].strip() return url _typeprog = None def splittype(url): """splittype('type:opaquestring') --> 'type', 'opaquestring'.""" global _typeprog if _typeprog is None: import re _typeprog = re.compile('^([^/:]+):') match = _typeprog.match(url) if match: scheme = match.group(1) return scheme.lower(), url[len(scheme) + 1:] return None, url _hostprog = None def splithost(url): """splithost('//host[:port]/path') --> 'host[:port]', '/path'.""" global _hostprog if _hostprog is None: _hostprog = re.compile('//([^/#?]*)(.*)', re.DOTALL) match = _hostprog.match(url) if match: host_port = match.group(1) path = match.group(2) if path and not path.startswith('/'): path = '/' + path return host_port, path return None, url _userprog = None def splituser(host): """splituser('user[:passwd]@host[:port]') --> 'user[:passwd]', 'host[:port]'.""" global _userprog if _userprog is None: import re _userprog = re.compile('^(.*)@(.*)$') match = _userprog.match(host) if match: return match.group(1, 2) return None, host _passwdprog = None def splitpasswd(user): """splitpasswd('user:passwd') -> 'user', 'passwd'.""" global _passwdprog if _passwdprog is None: import re _passwdprog = re.compile('^([^:]*):(.*)$',re.S) match = _passwdprog.match(user) if match: return match.group(1, 2) return user, None # splittag('/path#tag') --> '/path', 'tag' _portprog = None def splitport(host): """splitport('host:port') --> 'host', 'port'.""" global _portprog if _portprog is None: import re _portprog = re.compile('^(.*):([0-9]*)$') match = _portprog.match(host) if match: host, port = match.groups() if port: return host, port return host, None _nportprog = None def splitnport(host, defport=-1): """Split host and port, returning numeric port. Return given default port if no ':' found; defaults to -1. Return numerical port if a valid number are found after ':'. Return None if ':' but not a valid number.""" global _nportprog if _nportprog is None: import re _nportprog = re.compile('^(.*):(.*)$') match = _nportprog.match(host) if match: host, port = match.group(1, 2) if port: try: nport = int(port) except ValueError: nport = None return host, nport return host, defport _queryprog = None def splitquery(url): """splitquery('/path?query') --> '/path', 'query'.""" global _queryprog if _queryprog is None: import re _queryprog = re.compile('^(.*)\?([^?]*)$') match = _queryprog.match(url) if match: return match.group(1, 2) return url, None _tagprog = None def splittag(url): """splittag('/path#tag') --> '/path', 'tag'.""" global _tagprog if _tagprog is None: import re _tagprog = re.compile('^(.*)#([^#]*)$') match = _tagprog.match(url) if match: return match.group(1, 2) return url, None def splitattr(url): """splitattr('/path;attr1=value1;attr2=value2;...') -> '/path', ['attr1=value1', 'attr2=value2', ...].""" words = url.split(';') return words[0], words[1:] _valueprog = None def splitvalue(attr): """splitvalue('attr=value') --> 'attr', 'value'.""" global _valueprog if _valueprog is None: import re _valueprog = re.compile('^([^=]*)=(.*)$') match = _valueprog.match(attr) if match: return match.group(1, 2) return attr, None # urlparse contains a duplicate of this method to avoid a circular import. If # you update this method, also update the copy in urlparse. This code # duplication does not exist in Python3. _hexdig = '0123456789ABCDEFabcdef' _hextochr = dict((a + b, chr(int(a + b, 16))) for a in _hexdig for b in _hexdig) _asciire = re.compile('([\x00-\x7f]+)') def unquote(s): """unquote('abc%20def') -> 'abc def'.""" if _is_unicode(s): if '%' not in s: return s bits = _asciire.split(s) res = [bits[0]] append = res.append for i in range(1, len(bits), 2): append(unquote(str(bits[i])).decode('latin1')) append(bits[i + 1]) return ''.join(res) bits = s.split('%') # fastpath if len(bits) == 1: return s res = [bits[0]] append = res.append for item in bits[1:]: try: append(_hextochr[item[:2]]) append(item[2:]) except KeyError: append('%') append(item) return ''.join(res) def unquote_plus(s): """unquote('%7e/abc+def') -> '~/abc def'""" s = s.replace('+', ' ') return unquote(s) always_safe = ('ABCDEFGHIJKLMNOPQRSTUVWXYZ' 'abcdefghijklmnopqrstuvwxyz' '0123456789' '_.-') _safe_map = {} for i, c in zip(xrange(256), str(bytearray(xrange(256)))): _safe_map[c] = c if (i < 128 and c in always_safe) else '%{:02X}'.format(i) _safe_quoters = {} def quote(s, safe='/'): """quote('abc def') -> 'abc%20def' Each part of a URL, e.g. the path info, the query, etc., has a different set of reserved characters that must be quoted. RFC 2396 Uniform Resource Identifiers (URI): Generic Syntax lists the following reserved characters. reserved = ";" | "/" | "?" | ":" | "@" | "&" | "=" | "+" | "$" | "," Each of these characters is reserved in some component of a URL, but not necessarily in all of them. By default, the quote function is intended for quoting the path section of a URL. Thus, it will not encode '/'. This character is reserved, but in typical usage the quote function is being called on a path where the existing slash characters are used as reserved characters. """ # fastpath if not s: if s is None: raise TypeError('None object cannot be quoted') return s cachekey = (safe, always_safe) try: (quoter, safe) = _safe_quoters[cachekey] except KeyError: safe_map = _safe_map.copy() safe_map.update([(c, c) for c in safe]) quoter = safe_map.__getitem__ safe = always_safe + safe _safe_quoters[cachekey] = (quoter, safe) if not s.rstrip(safe): return s return ''.join(map(quoter, s)) def quote_plus(s, safe=''): """Quote the query fragment of a URL; replacing ' ' with '+'""" if ' ' in s: s = quote(s, safe + ' ') return s.replace(' ', '+') return quote(s, safe) def urlencode(query, doseq=0): """Encode a sequence of two-element tuples or dictionary into a URL query string. If any values in the query arg are sequences and doseq is true, each sequence element is converted to a separate parameter. If the query arg is a sequence of two-element tuples, the order of the parameters in the output will match the order of parameters in the input. """ if hasattr(query,"items"): # mapping objects query = query.items() else: # it's a bother at times that strings and string-like objects are # sequences... try: # non-sequence items should not work with len() # non-empty strings will fail this if len(query) and not isinstance(query[0], tuple): raise TypeError # zero-length sequences of all types will get here and succeed, # but that's a minor nit - since the original implementation # allowed empty dicts that type of behavior probably should be # preserved for consistency except TypeError: ty,va,tb = sys.exc_info() raise TypeError, "not a valid non-string sequence or mapping object", tb l = [] if not doseq: # preserve old behavior for k, v in query: k = quote_plus(str(k)) v = quote_plus(str(v)) l.append(k + '=' + v) else: for k, v in query: k = quote_plus(str(k)) if isinstance(v, str): v = quote_plus(v) l.append(k + '=' + v) elif _is_unicode(v): # is there a reasonable way to convert to ASCII? # encode generates a string, but "replace" or "ignore" # lose information and "strict" can raise UnicodeError v = quote_plus(v.encode("ASCII","replace")) l.append(k + '=' + v) else: try: # is this a sufficient test for sequence-ness? len(v) except TypeError: # not a sequence v = quote_plus(str(v)) l.append(k + '=' + v) else: # loop over the sequence for elt in v: l.append(k + '=' + quote_plus(str(elt))) return '&'.join(l) # Proxy handling def getproxies_environment(): """Return a dictionary of scheme -> proxy server URL mappings. Scan the environment for variables named <scheme>_proxy; this seems to be the standard convention. In order to prefer lowercase variables, we process the environment in two passes, first matches any and second matches only lower case proxies. If you need a different way, you can pass a proxies dictionary to the [Fancy]URLopener constructor. """ # Get all variables proxies = {} for name, value in os.environ.items(): name = name.lower() if value and name[-6:] == '_proxy': proxies[name[:-6]] = value # CVE-2016-1000110 - If we are running as CGI script, forget HTTP_PROXY # (non-all-lowercase) as it may be set from the web server by a "Proxy:" # header from the client # If "proxy" is lowercase, it will still be used thanks to the next block if 'REQUEST_METHOD' in os.environ: proxies.pop('http', None) # Get lowercase variables for name, value in os.environ.items(): if name[-6:] == '_proxy': name = name.lower() if value: proxies[name[:-6]] = value else: proxies.pop(name[:-6], None) return proxies def proxy_bypass_environment(host, proxies=None): """Test if proxies should not be used for a particular host. Checks the proxies dict for the value of no_proxy, which should be a list of comma separated DNS suffixes, or '*' for all hosts. """ if proxies is None: proxies = getproxies_environment() # don't bypass, if no_proxy isn't specified try: no_proxy = proxies['no'] except KeyError: return 0 # '*' is special case for always bypass if no_proxy == '*': return 1 # strip port off host hostonly, port = splitport(host) # check if the host ends with any of the DNS suffixes no_proxy_list = [proxy.strip() for proxy in no_proxy.split(',')] for name in no_proxy_list: if name: name = name.lstrip('.') # ignore leading dots name = re.escape(name) pattern = r'(.+\.)?%s$' % name if (re.match(pattern, hostonly, re.I) or re.match(pattern, host, re.I)): return 1 # otherwise, don't bypass return 0 if sys.platform == 'darwin': from _scproxy import _get_proxy_settings, _get_proxies def proxy_bypass_macosx_sysconf(host): """ Return True iff this host shouldn't be accessed using a proxy This function uses the MacOSX framework SystemConfiguration to fetch the proxy information. """ import re import socket from fnmatch import fnmatch hostonly, port = splitport(host) def ip2num(ipAddr): parts = ipAddr.split('.') parts = map(int, parts) if len(parts) != 4: parts = (parts + [0, 0, 0, 0])[:4] return (parts[0] << 24) | (parts[1] << 16) | (parts[2] << 8) | parts[3] proxy_settings = _get_proxy_settings() # Check for simple host names: if '.' not in host: if proxy_settings['exclude_simple']: return True hostIP = None for value in proxy_settings.get('exceptions', ()): # Items in the list are strings like these: *.local, 169.254/16 if not value: continue m = re.match(r"(\d+(?:\.\d+)*)(/\d+)?", value) if m is not None: if hostIP is None: try: hostIP = socket.gethostbyname(hostonly) hostIP = ip2num(hostIP) except socket.error: continue base = ip2num(m.group(1)) mask = m.group(2) if mask is None: mask = 8 * (m.group(1).count('.') + 1) else: mask = int(mask[1:]) mask = 32 - mask if (hostIP >> mask) == (base >> mask): return True elif fnmatch(host, value): return True return False def getproxies_macosx_sysconf(): """Return a dictionary of scheme -> proxy server URL mappings. This function uses the MacOSX framework SystemConfiguration to fetch the proxy information. """ return _get_proxies() def proxy_bypass(host): """Return True, if a host should be bypassed. Checks proxy settings gathered from the environment, if specified, or from the MacOSX framework SystemConfiguration. """ proxies = getproxies_environment() if proxies: return proxy_bypass_environment(host, proxies) else: return proxy_bypass_macosx_sysconf(host) def getproxies(): return getproxies_environment() or getproxies_macosx_sysconf() elif os.name == 'nt': def getproxies_registry(): """Return a dictionary of scheme -> proxy server URL mappings. Win32 uses the registry to store proxies. """ proxies = {} try: import _winreg except ImportError: # Std module, so should be around - but you never know! return proxies try: internetSettings = _winreg.OpenKey(_winreg.HKEY_CURRENT_USER, r'Software\Microsoft\Windows\CurrentVersion\Internet Settings') proxyEnable = _winreg.QueryValueEx(internetSettings, 'ProxyEnable')[0] if proxyEnable: # Returned as Unicode but problems if not converted to ASCII proxyServer = str(_winreg.QueryValueEx(internetSettings, 'ProxyServer')[0]) if '=' in proxyServer: # Per-protocol settings for p in proxyServer.split(';'): protocol, address = p.split('=', 1) # See if address has a type:// prefix import re if not re.match('^([^/:]+)://', address): address = '%s://%s' % (protocol, address) proxies[protocol] = address else: # Use one setting for all protocols if proxyServer[:5] == 'http:': proxies['http'] = proxyServer else: proxies['http'] = 'http://%s' % proxyServer proxies['https'] = 'https://%s' % proxyServer proxies['ftp'] = 'ftp://%s' % proxyServer internetSettings.Close() except (WindowsError, ValueError, TypeError): # Either registry key not found etc, or the value in an # unexpected format. # proxies already set up to be empty so nothing to do pass return proxies def getproxies(): """Return a dictionary of scheme -> proxy server URL mappings. Returns settings gathered from the environment, if specified, or the registry. """ return getproxies_environment() or getproxies_registry() def proxy_bypass_registry(host): try: import _winreg import re except ImportError: # Std modules, so should be around - but you never know! return 0 try: internetSettings = _winreg.OpenKey(_winreg.HKEY_CURRENT_USER, r'Software\Microsoft\Windows\CurrentVersion\Internet Settings') proxyEnable = _winreg.QueryValueEx(internetSettings, 'ProxyEnable')[0] proxyOverride = str(_winreg.QueryValueEx(internetSettings, 'ProxyOverride')[0]) # ^^^^ Returned as Unicode but problems if not converted to ASCII except WindowsError: return 0 if not proxyEnable or not proxyOverride: return 0 # try to make a host list from name and IP address. rawHost, port = splitport(host) host = [rawHost] try: addr = socket.gethostbyname(rawHost) if addr != rawHost: host.append(addr) except socket.error: pass try: fqdn = socket.getfqdn(rawHost) if fqdn != rawHost: host.append(fqdn) except socket.error: pass # make a check value list from the registry entry: replace the # '<local>' string by the localhost entry and the corresponding # canonical entry. proxyOverride = proxyOverride.split(';') # now check if we match one of the registry values. for test in proxyOverride: if test == '<local>': if '.' not in rawHost: return 1 test = test.replace(".", r"\.") # mask dots test = test.replace("*", r".*") # change glob sequence test = test.replace("?", r".") # change glob char for val in host: # print "%s <--> %s" %( test, val ) if re.match(test, val, re.I): return 1 return 0 def proxy_bypass(host): """Return True, if the host should be bypassed. Checks proxy settings gathered from the environment, if specified, or the registry. """ proxies = getproxies_environment() if proxies: return proxy_bypass_environment(host, proxies) else: return proxy_bypass_registry(host) else: # By default use environment variables getproxies = getproxies_environment proxy_bypass = proxy_bypass_environment # Test and time quote() and unquote() def test1(): s = '' for i in range(256): s = s + chr(i) s = s*4 t0 = time.time() qs = quote(s) uqs = unquote(qs) t1 = time.time() if uqs != s: print 'Wrong!' print repr(s) print repr(qs) print repr(uqs) print round(t1 - t0, 3), 'sec' def reporthook(blocknum, blocksize, totalsize): # Report during remote transfers print "Block number: %d, Block size: %d, Total size: %d" % ( blocknum, blocksize, totalsize)
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