1 files changed, 164 insertions, 0 deletions
diff --git a/netlib/wsgi.py b/netlib/wsgi.py
new file mode 100644
index 00000000..d6dfae5d
--- /dev/null
+++ b/netlib/wsgi.py
@@ -0,0 +1,164 @@
+from __future__ import (absolute_import, print_function, division)
+from io import BytesIO, StringIO
+import urllib
+import time
+import traceback
+
+import six
+from six.moves import urllib
+
+from netlib.utils import always_bytes, native
+from . import http, tcp
+
+class ClientConn(object):
+
+    def __init__(self, address):
+        self.address = tcp.Address.wrap(address)
+
+
+class Flow(object):
+
+    def __init__(self, address, request):
+        self.client_conn = ClientConn(address)
+        self.request = request
+
+
+class Request(object):
+
+    def __init__(self, scheme, method, path, http_version, headers, content):
+        self.scheme, self.method, self.path = scheme, method, path
+        self.headers, self.content = headers, content
+        self.http_version = http_version
+
+
+def date_time_string():
+    """Return the current date and time formatted for a message header."""
+    WEEKS = ['Mon', 'Tue', 'Wed', 'Thu', 'Fri', 'Sat', 'Sun']
+    MONTHS = [
+        None,
+        'Jan', 'Feb', 'Mar', 'Apr', 'May', 'Jun',
+        'Jul', 'Aug', 'Sep', 'Oct', 'Nov', 'Dec'
+    ]
+    now = time.time()
+    year, month, day, hh, mm, ss, wd, y_, z_ = time.gmtime(now)
+    s = "%s, %02d %3s %4d %02d:%02d:%02d GMT" % (
+        WEEKS[wd],
+        day, MONTHS[month], year,
+        hh, mm, ss
+    )
+    return s
+
+
+class WSGIAdaptor(object):
+
+    def __init__(self, app, domain, port, sversion):
+        self.app, self.domain, self.port, self.sversion = app, domain, port, sversion
+
+    def make_environ(self, flow, errsoc, **extra):
+        path = native(flow.request.path, "latin-1")
+        if '?' in path:
+            path_info, query = native(path, "latin-1").split('?', 1)
+        else:
+            path_info = path
+            query = ''
+        environ = {
+            'wsgi.version': (1, 0),
+            'wsgi.url_scheme': native(flow.request.scheme, "latin-1"),
+            'wsgi.input': BytesIO(flow.request.content or b""),
+            'wsgi.errors': errsoc,
+            'wsgi.multithread': True,
+            'wsgi.multiprocess': False,
+            'wsgi.run_once': False,
+            'SERVER_SOFTWARE': self.sversion,
+            'REQUEST_METHOD': native(flow.request.method, "latin-1"),
+            'SCRIPT_NAME': '',
+            'PATH_INFO': urllib.parse.unquote(path_info),
+            'QUERY_STRING': query,
+            'CONTENT_TYPE': native(flow.request.headers.get('Content-Type', ''), "latin-1"),
+            'CONTENT_LENGTH': native(flow.request.headers.get('Content-Length', ''), "latin-1"),
+            'SERVER_NAME': self.domain,
+            'SERVER_PORT': str(self.port),
+            'SERVER_PROTOCOL': native(flow.request.http_version, "latin-1"),
+        }
+        environ.update(extra)
+        if flow.client_conn.address:
+            environ["REMOTE_ADDR"] = native(flow.client_conn.address.host, "latin-1")
+            environ["REMOTE_PORT"] = flow.client_conn.address.port
+
+        for key, value in flow.request.headers.items():
+            key = 'HTTP_' + native(key, "latin-1").upper().replace('-', '_')
+            if key not in ('HTTP_CONTENT_TYPE', 'HTTP_CONTENT_LENGTH'):
+                environ[key] = value
+        return environ
+
+    def error_page(self, soc, headers_sent, s):
+        """
+            Make a best-effort attempt to write an error page. If headers are
+            already sent, we just bung the error into the page.
+        """
+        c = """
+            <html>
+                <h1>Internal Server Error</h1>
+                <pre>{err}"</pre>
+            </html>
+        """.format(err=s).strip().encode()
+
+        if not headers_sent:
+            soc.write(b"HTTP/1.1 500 Internal Server Error\r\n")
+            soc.write(b"Content-Type: text/html\r\n")
+            soc.write("Content-Length: {length}\r\n".format(length=len(c)).encode())
+            soc.write(b"\r\n")
+        soc.write(c)
+
+    def serve(self, request, soc, **env):
+        state = dict(
+            response_started=False,
+            headers_sent=False,
+            status=None,
+            headers=None
+        )
+
+        def write(data):
+            if not state["headers_sent"]:
+                soc.write("HTTP/1.1 {status}\r\n".format(status=state["status"]).encode())
+                headers = state["headers"]
+                if 'server' not in headers:
+                    headers["Server"] = self.sversion
+                if 'date' not in headers:
+                    headers["Date"] = date_time_string()
+                soc.write(bytes(headers))
+                soc.write(b"\r\n")
+                state["headers_sent"] = True
+            if data:
+                soc.write(data)
+            soc.flush()
+
+        def start_response(status, headers, exc_info=None):
+            if exc_info:
+                if state["headers_sent"]:
+                    six.reraise(*exc_info)
+            elif state["status"]:
+                raise AssertionError('Response already started')
+            state["status"] = status
+            state["headers"] = http.Headers([[always_bytes(k), always_bytes(v)] for k,v in headers])
+            if exc_info:
+                self.error_page(soc, state["headers_sent"], traceback.format_tb(exc_info[2]))
+                state["headers_sent"] = True
+
+        errs = six.BytesIO()
+        try:
+            dataiter = self.app(
+                self.make_environ(request, errs, **env), start_response
+            )
+            for i in dataiter:
+                write(i)
+            if not state["headers_sent"]:
+                write(b"")
+        except Exception as e:
+            try:
+                s = traceback.format_exc()
+                errs.write(s.encode("utf-8", "replace"))
+                self.error_page(soc, state["headers_sent"], s)
+            except Exception:    # pragma: no cover
+                pass
+        return errs.getvalue()