1 files changed, 153 insertions, 0 deletions
diff --git a/AptUrl/Parser.py b/AptUrl/Parser.py
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+++ b/AptUrl/Parser.py
@@ -0,0 +1,153 @@
+# Copyright (c) 2007-2008 Canonical
+#
+# AUTHOR:
+# Michael Vogt <mvo@ubuntu.com>
+# With contributions by Siegfried-A. Gevatter <rainct@ubuntu.com>
+#
+# This file is part of AptUrl
+#
+# AptUrl is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License as published
+# by the Free Software Foundation; either version 2 of the License, or (at
+# your option) any later version.
+#
+# AptUrl is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+# General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with AptUrl; if not, write to the Free Software
+# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+
+import os
+import string
+from string import Template
+from .Helpers import get_dist
+from .Helpers import _
+
+class InvalidUrlException(Exception):
+    def __init__(self, url, msg=""):
+        self.url = url
+        self.message = msg
+    def __str__(self):
+        return self.message
+
+MAX_URL_LEN=255
+
+# substituion mapping
+apturl_substitution_mapping = {
+    "distro" : get_dist(),
+    "kernel" : os.uname()[2] 
+}
+
+# whitelist for the uri
+whitelist = []
+whitelist.extend(string.ascii_letters)
+whitelist.extend(string.digits)
+whitelist.extend(['_',':','?','/','+','.','~','=','<','>','-',',','$','&'])
+
+
+class AptUrl(object):
+    " a class that contains the parsed data from an apt url "
+    def __init__(self):
+        self.package = None
+        self.schema = None
+        self.minver = None
+        self.refresh = None
+        # for added repos
+        self.keyfile = None
+        self.repo_url = None
+        self.dist = '/'     
+        # for known sections 
+        self.section = []
+        # for known channels
+        self.channel = None
+
+def is_format_package_name(string):
+    " return True if string would be an acceptable name for a Debian package "
+    
+    return (string.replace("+", "").replace("-", "").replace(".", "").replace(":", "").isalnum() 
+        and string.islower() and string[0].isalnum() and len(string) > 1)
+
+def do_apt_url_substitution(apt_url, mapping):
+    " substitute known templates against the field package and channel "
+    for field in ["package","channel"]:
+        if getattr(apt_url, field):
+            s=Template(getattr(apt_url, field))
+            setattr(apt_url, field, s.substitute(mapping))
+
+def match_against_whitelist(raw_url):
+    " test if the url matches the internal whitelist "
+    for char in raw_url:
+        if not char in whitelist:
+            raise InvalidUrlException(
+                raw_url, _("Non whitelist char in the uri"))
+    return True
+
+def set_value(apt_url, s):
+    " set a key,value pair from string s to AptUrl object "
+    (key, value) = s.split("=")
+    try:
+        if ' ' in value:
+            raise InvalidUrlException(apt_url, _("Whitespace in key=value"))
+        if type(getattr(apt_url, key)) == type([]):
+            getattr(apt_url, key).append(value)
+        else:
+            setattr(apt_url, key, value)
+    except Exception as e:
+        raise InvalidUrlException(apt_url, _("Exception '%s'") % e)
+
+
+def parse(full_url, mapping=apturl_substitution_mapping):
+    " parse an apt url and return a list of AptUrl objects "
+    # apt:pkg1?k11=v11?k12=v12,pkg2?k21=v21?k22=v22,...
+    res = []
+    
+    if len(full_url) > MAX_URL_LEN:
+        url = "%s ..." % full_url[0:(MAX_URL_LEN // 10)]
+        raise InvalidUrlException(url, _("Url string '%s' too long") % url)
+
+    # check against whitelist
+    match_against_whitelist(full_url)
+    for url in full_url.split(";"):
+        if not ":" in url:
+            raise InvalidUrlException(url, _("No ':' in the uri"))
+
+        # now parse it
+
+        (schema, packages) = url.split(":", 1)
+        packages = packages.split(",")
+
+        for package in packages:
+            apt_url = AptUrl()
+            apt_url.schema = schema
+            # check for schemas of the form: apt+http://
+            if schema.startswith("apt+"):
+                apt_url.repo_url = schema[len("apt+"):] + ":" + package.split("?",1)[0]
+            else:
+                if "?" in package:
+                    apt_url.package = package.split("?")[0].lstrip("/")
+                else:
+                    apt_url.package = package.lstrip("/")
+
+            # now parse the ?... bits
+            if "?" in package:
+                key_value_pairs = package.split("?")[1:]
+                for s in key_value_pairs:
+                    if "&" in s:
+                        and_key_value_pairs = s.split("&")
+                        for s in and_key_value_pairs:
+                            set_value(apt_url, s)
+                    else:
+                        set_value(apt_url, s)
+
+            # do substitution (if needed) 
+            do_apt_url_substitution(apt_url, mapping)
+            
+            # check if the package name is valid
+            if not is_format_package_name(apt_url.package):
+                raise InvalidUrlException(url, "Invalid package name '%s'" % apt_url.package)
+            
+            res.append(apt_url)
+    return res