TCP support

pysnmp/carrier/asyncore/stream/base.py

@@ -0,0 +1,187 @@
+#
+# This file is part of pysnmp software.
+#
+# Copyright (c) 2005-2018, Ilya Etingof <etingof@gmail.com>
+# License: http://snmplabs.com/pysnmp/license.html
+#
+# Author: Edgar Sousa <edg@edgsousa.xyz>
+#
+import errno
+import socket
+import struct
+import sys
+
+from pysnmp import debug
+from pysnmp.carrier import sockmsg, error
+from ..dgram.base import DgramSocketTransport
+
+# Ignore these socket errors
+sockErrors = {errno.ESHUTDOWN: True,
+              errno.ENOTCONN: True,
+              errno.ECONNRESET: False,
+              errno.ECONNREFUSED: False,
+              errno.EAGAIN: False,
+              errno.EWOULDBLOCK: False,
+              errno.WSAEWOULDBLOCK: False,}
+
+if hasattr(errno, 'EBADFD'):
+    # bad FD may happen upon FD closure on n-1 select() event
+    sockErrors[errno.EBADFD] = True
+
+
+class StreamSocketTransport(DgramSocketTransport):
+    sockType = socket.SOCK_STREAM
+
+    def __init__(self, sock=None, sockMap=None):
+        DgramSocketTransport.__init__(self, sock, sockMap)
+        self.__outQueue = []
+        self._sendto = lambda s, b, a: s.send(b)
+
+        def __recvfrom(s, sz):
+            header_data = bytearray(s.recv(2))
+            if header_data:
+                #1st byte is 0x30 - sequence
+                seq_len = header_data[1]
+                if seq_len & 0x80 != 0:  # BER long definite length
+                    seq_len &= 0x7f
+                    payload_len = bytearray(s.recv(seq_len))
+                    header_data += payload_len
+                    remaining_bytes, = struct.unpack("!I", bytearray([0]*(4-seq_len))+payload_len)
+                else:
+                    remaining_bytes = seq_len
+
+                payload_data = bytearray(s.recv(remaining_bytes))
+
+            return bytes(header_data+payload_data), self.addressType(s.getpeername())
+
+        self._recvfrom = __recvfrom
+
+
+    def openClientMode(self, iface=None, targetAddress=None):
+        # do nothing
+        if targetAddress:
+            self.socket.setblocking(1)
+            self.socket.connect(targetAddress)
+            self.socket.setblocking(0)
+        return self
+
+    def openServerMode(self, iface):
+        # doesn't make sense
+        return self
+
+    def enableBroadcast(self, flag=1):
+        try:
+            self.socket.setsockopt(
+                socket.SOL_SOCKET, socket.SO_BROADCAST, flag
+            )
+        except socket.error:
+            raise error.CarrierError('setsockopt() for SO_BROADCAST failed: %s' % (sys.exc_info()[1],))
+        debug.logger & debug.flagIO and debug.logger('enableBroadcast: %s option SO_BROADCAST on socket %s' % (flag and "enabled" or "disabled", self.socket.fileno()))
+        return self
+
+    def enablePktInfo(self, flag=1):
+        if (not hasattr(self.socket, 'sendmsg') or
+                not hasattr(self.socket, 'recvmsg')):
+            raise error.CarrierError('sendmsg()/recvmsg() interface is not supported by this OS and/or Python version')
+
+        try:
+            if self.socket.family in (socket.AF_INET, socket.AF_INET6):
+                self.socket.setsockopt(socket.SOL_IP, socket.IP_PKTINFO, flag)
+            if self.socket.family == socket.AF_INET6:
+                self.socket.setsockopt(socket.SOL_IPV6, socket.IPV6_RECVPKTINFO, flag)
+        except socket.error:
+            raise error.CarrierError('setsockopt() for %s failed: %s' % (self.socket.family == socket.AF_INET6 and "IPV6_RECVPKTINFO" or "IP_PKTINFO", sys.exc_info()[1]))
+
+        self._sendto = sockmsg.getSendTo(self.addressType)
+        self._recvfrom = sockmsg.getRecvFrom(self.addressType)
+
+        debug.logger & debug.flagIO and debug.logger('enablePktInfo: %s option %s on socket %s' % (self.socket.family == socket.AF_INET6 and "IPV6_RECVPKTINFO" or "IP_PKTINFO", flag and "enabled" or "disabled", self.socket.fileno()))
+        return self
+
+    def enableTransparent(self, flag=1):
+        try:
+            if self.socket.family == socket.AF_INET:
+                self.socket.setsockopt(
+                    socket.SOL_IP, socket.IP_TRANSPARENT, flag
+                )
+            if self.socket.family == socket.AF_INET6:
+                self.socket.setsockopt(
+                    socket.SOL_IPV6, socket.IP_TRANSPARENT, flag
+                )
+        except socket.error:
+            raise error.CarrierError('setsockopt() for IP_TRANSPARENT failed: %s' % sys.exc_info()[1])
+        except OSError:
+            raise error.CarrierError('IP_TRANSPARENT socket option requires superuser priveleges')
+
+        debug.logger & debug.flagIO and debug.logger('enableTransparent: %s option IP_TRANSPARENT on socket %s' % (flag and "enabled" or "disabled", self.socket.fileno()))
+        return self
+
+    def sendMessage(self, outgoingMessage, transportAddress):
+        self.__outQueue.append(
+            (outgoingMessage, self.normalizeAddress(transportAddress))
+        )
+        debug.logger & debug.flagIO and debug.logger('sendMessage: outgoingMessage queued (%d octets) %s' % (len(outgoingMessage), debug.hexdump(outgoingMessage)))
+
+    def normalizeAddress(self, transportAddress):
+        if not isinstance(transportAddress, self.addressType):
+            transportAddress = self.addressType(transportAddress)
+        if not transportAddress.getLocalAddress():
+            transportAddress.setLocalAddress(self.getLocalAddress())
+        return transportAddress
+
+    def getLocalAddress(self):
+        # one evil OS does not seem to support getsockname() for DGRAM sockets
+        try:
+            return self.socket.getsockname()
+        except Exception:
+            return '0.0.0.0', 0
+
+    # asyncore API
+    def handle_connect(self):
+        pass
+
+    def writable(self):
+        return self.__outQueue
+
+    def handle_write(self):
+        outgoingMessage, transportAddress = self.__outQueue.pop(0)
+        debug.logger & debug.flagIO and debug.logger('handle_write: transportAddress %r -> %r outgoingMessage (%d octets) %s' % (transportAddress.getLocalAddress(), transportAddress, len(outgoingMessage), debug.hexdump(outgoingMessage)))
+        if not transportAddress:
+            debug.logger & debug.flagIO and debug.logger('handle_write: missing dst address, loosing outgoing msg')
+            return
+        try:
+            self._sendto(
+                self.socket, outgoingMessage, transportAddress
+            )
+        except socket.error:
+            if sys.exc_info()[1].args[0] in sockErrors:
+                debug.logger & debug.flagIO and debug.logger('handle_write: ignoring socket error %s' % (sys.exc_info()[1],))
+            else:
+                raise error.CarrierError('sendto() failed for %s: %s' % (transportAddress, sys.exc_info()[1]))
+
+    def readable(self):
+        return 1
+
+    def handle_read(self):
+        try:
+            incomingMessage, transportAddress = self._recvfrom(self.socket, 65535)
+            transportAddress = self.normalizeAddress(transportAddress)
+            debug.logger & debug.flagIO and debug.logger(
+                'handle_read: transportAddress %r -> %r incomingMessage (%d octets) %s' % (transportAddress, transportAddress.getLocalAddress(), len(incomingMessage), debug.hexdump(incomingMessage)))
+            if not incomingMessage:
+                self.handle_close()
+                return
+            else:
+                self._cbFun(self, transportAddress, incomingMessage)
+                return
+        except socket.error:
+            if sys.exc_info()[1].args[0] in sockErrors:
+                debug.logger & debug.flagIO and debug.logger('handle_read: known socket error %s' % (sys.exc_info()[1],))
+                sockErrors[sys.exc_info()[1].args[0]] and self.handle_close()
+                return
+            else:
+                raise error.CarrierError('recvfrom() failed: %s' % (sys.exc_info()[1],))
+
+    def handle_close(self):
+        self.socket.shutdown()
+        self.socket.close()

pysnmp/carrier/asyncore/stream/tcp.py

@@ -0,0 +1,23 @@
+#
+# This file is part of pysnmp software.
+#
+# Copyright (c) 2005-2018, Ilya Etingof <etingof@gmail.com>
+# License: http://snmplabs.com/pysnmp/license.html
+#
+# Author: Edgar Sousa <edg@edgsousa.xyz>
+#
+from socket import AF_INET
+
+from pysnmp.carrier.asyncore.stream.base import StreamSocketTransport
+from pysnmp.carrier.base import AbstractTransportAddress
+
+domainName = snmpTCPDomain = (1, 3, 6, 1, 2, 1, 100, 1, 5)
+
+
+class TcpTransportAddress(tuple, AbstractTransportAddress):
+    pass
+
+
+class TcpSocketTransport(StreamSocketTransport):
+    sockFamily = AF_INET
+    addressType = TcpTransportAddress

pysnmp/entity/config.py

@@ -6,6 +6,7 @@
 #
 from pyasn1.compat.octets import null
 from pysnmp.carrier.asyncore.dgram import udp, udp6
+from pysnmp.carrier.asyncore.stream import tcp
 from pysnmp.proto.secmod.rfc3414.auth import hmacmd5, hmacsha, noauth
 from pysnmp.proto.secmod.rfc3414.priv import des, nopriv
 from pysnmp.proto.secmod.rfc3826.priv import aes
@@ -19,6 +20,7 @@
 # Transports
 snmpUDPDomain = udp.snmpUDPDomain
 snmpUDP6Domain = udp6.snmpUDP6Domain
+snmpTCPDomain = tcp.snmpTCPDomain
 
 # Auth protocol
 usmHMACMD5AuthProtocol = hmacmd5.HmacMd5.serviceID
@@ -312,6 +314,12 @@ def addTargetAddr(snmpEngine, addrName, transportDomain, transportAddress,
         if sourceAddress is None:
             sourceAddress = ('::', 0)
         sourceAddress = TransportAddressIPv6(sourceAddress)
+    elif transportDomain[:len(snmpTCPDomain)] == snmpTCPDomain:
+        TransportAddressIPv4, = mibBuilder.importSymbols('TRANSPORT-ADDRESS-MIB', 'TransportAddressIPv4')
+        transportAddress = TransportAddressIPv4(transportAddress)
+        if sourceAddress is None:
+            sourceAddress = ('0.0.0.0', 0)
+        sourceAddress = TransportAddressIPv4(sourceAddress)
 
     snmpEngine.msgAndPduDsp.mibInstrumController.writeVars(
         (snmpTargetAddrEntry.name + (9,) + tblIdx, 'destroy'),

pysnmp/entity/rfc3413/config.py

@@ -75,11 +75,18 @@ def getTargetAddr(snmpEngine, snmpTargetAddrName):
             snmpTargetAddrTAddress = transport.addressType(
                 TransportAddressIPv6(snmpTargetAddrTAddress)
             ).setLocalAddress(TransportAddressIPv6(snmpSourceAddrTAddress))
+        elif snmpTargetAddrTDomain[:len(config.snmpTCPDomain)] == config.snmpTCPDomain:
+            TransportAddressIPv4, = snmpEngine.msgAndPduDsp.mibInstrumController.mibBuilder.importSymbols(
+                'TRANSPORT-ADDRESS-MIB', 'TransportAddressIPv4')
+            snmpTargetAddrTAddress = transport.addressType(
+                TransportAddressIPv4(snmpTargetAddrTAddress)
+            ).setLocalAddress(TransportAddressIPv4(snmpSourceAddrTAddress))
         elif snmpTargetAddrTDomain[:len(config.snmpLocalDomain)] == config.snmpLocalDomain:
             snmpTargetAddrTAddress = transport.addressType(
                 snmpTargetAddrTAddress
             )
 
+
         nameToTargetMap[snmpTargetAddrName] = (
             snmpTargetAddrTDomain,
             snmpTargetAddrTAddress,

pysnmp/hlapi/v3arch/asyncore/transport.py

@@ -9,9 +9,63 @@
 
 from pysnmp import error
 from pysnmp.carrier.asyncore.dgram import udp, udp6
+from pysnmp.carrier.asyncore.stream import tcp
 from pysnmp.hlapi.transport import AbstractTransportTarget
 
-__all__ = ['Udp6TransportTarget', 'UdpTransportTarget']
+__all__ = ['Udp6TransportTarget', 'UdpTransportTarget', 'TcpTransportTarget']
+
+class TcpTransportTarget(AbstractTransportTarget):
+    """Creates TCP/IPv4 configuration and initialize socket API.
+    This object can be used for adding new entries to Local Configuration
+    Datastore (LCD) managed by :py:class:`~pysnmp.hlapi.SnmpEngine`
+    class instance.
+
+    See :RFC:`1906#section-3` for more information on the UDP transport mapping.
+
+    Parameters
+    ----------
+    transportAddr: :py:class:`tuple`
+        Indicates remote address in Python :py:mod:`socket` module format
+        which is a tuple of FQDN, port where FQDN is a string representing
+        either hostname or IPv4 address in quad-dotted form, port is an
+        integer.
+    timeout: :py:class:`int`
+        Response timeout in seconds.
+    retries: :py:class:`int`
+        Maximum number of request retries, 0 retries means just a single
+        request.
+    tagList: :py:class:`str`
+        Arbitrary string that contains a list of space-separated tag
+        strings used to select target addresses and/or SNMP configuration
+        (see :RFC:`3413#section-4.1.1`, :RFC:`2576#section-5.3` and
+        :py:class:`~pysnmp.hlapi.CommunityData` object).
+
+    Examples
+    --------
+    >>> from pysnmp.hlapi.v3arch.asyncore import UdpTransportTarget
+    >>> TcpTransportTarget(('demo.snmplabs.com', 161))
+    TcpTransportTarget(('195.218.195.228', 161), timeout=1, retries=5, tagList='')
+    >>>
+
+    """
+    transportDomain = tcp.domainName
+    protoTransport = tcp.TcpSocketTransport
+
+    def openClientMode(self):
+        self.transport = self.protoTransport().openClientMode(self.iface, self.transportAddr)
+        return self.transport
+
+    def _resolveAddr(self, transportAddr):
+        try:
+            return socket.getaddrinfo(transportAddr[0],
+                                      transportAddr[1],
+                                      socket.AF_INET,
+                                      socket.SOCK_STREAM,
+                                      socket.IPPROTO_TCP)[0][4][:2]
+        except socket.gaierror:
+            raise error.PySnmpError('Bad IPv4/TCP transport address %s: %s' % (
+                '@'.join([str(x) for x in transportAddr]), sys.exc_info()[1]))
+
 
 
 class UdpTransportTarget(AbstractTransportTarget):

pysnmp/smi/mibs/TRANSPORT-ADDRESS-MIB.py

@@ -36,7 +36,7 @@
 
         def inet_pton(address_family, ip_string):
             if address_family == socket.AF_INET:
-                return inet_aton(ip_string)
+                return socket.inet_aton(ip_string)
             elif address_family != socket.AF_INET6:
                 raise socket.error(
                     'Unknown address family %s' % (address_family,)
@@ -84,7 +84,7 @@ def inet_pton(address_family, ip_string):
 
         def inet_ntop(address_family, packed_ip):
             if address_family == socket.AF_INET:
-                return inet_ntop(packed_ip)
+                return socket.inet_ntoa(packed_ip)
             elif address_family != socket.AF_INET6:
                 raise socket.error(
                     'Unknown address family %s' % (address_family,)