commit 7e64119a665ecbfb3ee06d3ddcfe066f212f63f6 Author: Damian Johnson <atagar@torproject.org> Date: Tue Mar 20 08:53:08 2012 -0700 Making server descriptor validation optional Adding constructor pydocs and an argument to skip validation. This should have performance advantages and allow for best-effort parsing of malformed descriptor content. --- stem/descriptor/server_descriptor.py | 109 +++++++++++++++++++++------------ 1 files changed, 69 insertions(+), 40 deletions(-) diff --git a/stem/descriptor/server_descriptor.py b/stem/descriptor/server_descriptor.py index b4030d7..8e3f37b 100644 --- a/stem/descriptor/server_descriptor.py +++ b/stem/descriptor/server_descriptor.py @@ -133,7 +133,25 @@ class ServerDescriptorV2(Descriptor): hibernating = False family = unrecognized_entries = [] - def __init__(self, contents): + def __init__(self, contents, validate = True): + """ + Version 2 server descriptor constructor, created from an individual relay's + descriptor content (as provided by "GETINFO desc/*", cached descriptors, + and metrics). + + By default this validates the descriptor's content as it's parsed. This + validation can be disables to either improve performance or be accepting of + malformed data. + + Arguments: + contents (str) - descriptor content provided by the relay + validate (bool) - checks the validity of the descriptor's content if True, + skips these checks otherwise + + Raises: + ValueError if the contents is malformed and validate is True + """ + Descriptor.__init__(self, contents) # A descriptor contains a series of 'keyword lines' which are simply a @@ -160,6 +178,7 @@ class ServerDescriptorV2(Descriptor): line_match = KEYWORD_LINE.match(line) if not line_match: + if not validate: continue raise ValueError("Line contains invalid characters: %s" % line) keyword, value = line_match.groups() @@ -174,13 +193,14 @@ class ServerDescriptorV2(Descriptor): # validates restrictions about the entries - for keyword in REQUIRED_FIELDS: - if not keyword in entries: - raise ValueError("Descriptor must have a '%s' entry" % keyword - - for keyword in SINGLE_FIELDS + REQUIRED_FIELDS: - if keyword in entries and len(entries[keyword]) > 1: - raise ValueError("The '%s' entry can only appear once in a descriptor" % keyword) + if validate: + for keyword in REQUIRED_FIELDS: + if not keyword in entries: + raise ValueError("Descriptor must have a '%s' entry" % keyword + + for keyword in SINGLE_FIELDS + REQUIRED_FIELDS: + if keyword in entries and len(entries[keyword]) > 1: + raise ValueError("The '%s' entry can only appear once in a descriptor" % keyword) # parse all the entries into our attributes @@ -196,17 +216,20 @@ class ServerDescriptorV2(Descriptor): router_comp = value.split() if len(router_comp) != 5: + if not validate: continue raise ValueError("Router line must have five values: %s" % line - elif not stem.util.tor_tools.is_valid_nickname(router_comp[0]): - raise TypeError("Router line entry isn't a valid nickname: %s" % router_comp[0]) - elif not stem.util.connection.is_valid_ip_address(router_comp[1]): - raise TypeError("Router line entry isn't a valid IPv4 address: %s" % router_comp[1]) - elif not stem.util.connection.is_valid_port(router_comp[2], allow_zero = True): - raise TypeError("Router line's ORPort is invalid: %s" % router_comp[2]) - elif router_comp[3] != "0": - raise TypeError("Router line's SocksPort should be zero: %s" % router_comp[3]) - elif not stem.util.connection.is_valid_port(router_comp[4], allow_zero = True): - raise TypeError("Router line's DirPort is invalid: %s" % router_comp[4]) + + if validate: + if not stem.util.tor_tools.is_valid_nickname(router_comp[0]): + raise ValueError("Router line entry isn't a valid nickname: %s" % router_comp[0]) + elif not stem.util.connection.is_valid_ip_address(router_comp[1]): + raise ValueError("Router line entry isn't a valid IPv4 address: %s" % router_comp[1]) + elif not stem.util.connection.is_valid_port(router_comp[2], allow_zero = True): + raise ValueError("Router line's ORPort is invalid: %s" % router_comp[2]) + elif router_comp[3] != "0": + raise ValueError("Router line's SocksPort should be zero: %s" % router_comp[3]) + elif not stem.util.connection.is_valid_port(router_comp[4], allow_zero = True): + raise ValueError("Router line's DirPort is invalid: %s" % router_comp[4]) self.nickname = router_comp[0] self.address = router_comp[1] @@ -218,13 +241,16 @@ class ServerDescriptorV2(Descriptor): bandwidth_comp = value.split() if len(bandwidth_comp) != 3: + if not validate: continue raise ValueError("Bandwidth line must have three values: %s" % line - elif not bandwidth_comp[0].isdigit()): - raise TypeError("Bandwidth line's average rate isn't numeric: %s" % bandwidth_comp[0]) - elif not bandwidth_comp[1].isdigit()): - raise TypeError("Bandwidth line's burst rate isn't numeric: %s" % bandwidth_comp[1]) - elif not bandwidth_comp[2].isdigit()): - raise TypeError("Bandwidth line's observed rate isn't numeric: %s" % bandwidth_comp[2]) + + if validate: + if not bandwidth_comp[0].isdigit()): + raise ValueError("Bandwidth line's average rate isn't numeric: %s" % bandwidth_comp[0]) + elif not bandwidth_comp[1].isdigit()): + raise ValueError("Bandwidth line's burst rate isn't numeric: %s" % bandwidth_comp[1]) + elif not bandwidth_comp[2].isdigit()): + raise ValueError("Bandwidth line's observed rate isn't numeric: %s" % bandwidth_comp[2]) average_bandwidth = int(router_comp[0]) burst_bandwidth = int(router_comp[1]) @@ -252,48 +278,51 @@ class ServerDescriptorV2(Descriptor): try: self.published = datetime.datetime.strptime(value, "%Y-%m-%d %H:%M:%S") except ValueError: - raise TypeError("Published line's time wasn't parseable: %s" % line) + if validate: + raise ValueError("Published line's time wasn't parseable: %s" % line) elif keyword == "fingerprint": # This is fourty hex digits split into space separated groups of four. # Checking that we match this pattern. fingerprint = value.replace(" ", "") - for grouping in value.split(" "): - if len(grouping) != 4: - raise TypeError("Fingerprint line should have groupings of four hex digits: %s" % value) - - if not stem.util.tor_tools.is_valid_fingerprint(fingerprint): - raise TypeError("Tor relay fingerprints consist of fourty hex digits: %s" % value) + if validate: + for grouping in value.split(" "): + if len(grouping) != 4: + raise ValueError("Fingerprint line should have groupings of four hex digits: %s" % value) + + if not stem.util.tor_tools.is_valid_fingerprint(fingerprint): + raise ValueError("Tor relay fingerprints consist of fourty hex digits: %s" % value) self.fingerprint = fingerprint elif keyword == "hibernating": # "hibernating" 0|1 (in practice only set if one) - if not value in ("0", "1"): - raise TypeError("Hibernating line had an invalid value, must be zero or one: %s" % value) + if validate and not value in ("0", "1"): + raise ValueError("Hibernating line had an invalid value, must be zero or one: %s" % value) self.hibernating = value == "1" elif keyword == "uptime": if not value.isdigit(): - raise TypeError("Uptime line must have an integer value: %s" % value) + if not validate: continue + raise ValueError("Uptime line must have an integer value: %s" % value) self.uptime = int(value) elif keyword == "onion-key": - if not block_type or not block_contents: - raise TypeError("Onion key line must be followed by a public key: %s" % line) + if validate and (not block_type or not block_contents): + raise ValueError("Onion key line must be followed by a public key: %s" % line) self.onion_key_type = block_type self.onion_key = block_contents elif keyword == "signing-key": - if not block_type or not block_contents: - raise TypeError("Signing key line must be followed by a public key: %s" % line) + if validate and (not block_type or not block_contents): + raise ValueError("Signing key line must be followed by a public key: %s" % line) self.signing_key_type = block_type self.signing_key = block_contents elif keyword == "router-signature": - if not block_type or not block_contents: - raise TypeError("Router signature line must be followed by a signature block: %s" % line) + if validate and (not block_type or not block_contents): + raise ValueError("Router signature line must be followed by a signature block: %s" % line) self.router_sig_type = block_type self.router_sig = block_contents