daemon: refactored how interfaces are configured, updated link edits to allow proper bi-directional support for network to network interfaces, improved and added more unit tests for link add/edit/delete

daemon/core/api/grpc/server.py

@@ -288,17 +288,25 @@ class CoreGrpcServer(core_pb2_grpc.CoreApiServicer):
 
         # create links
         links = []
-        asym_links = []
+        edit_links = []
+        known_links = set()
         for link in request.session.links:
-            if link.options.unidirectional:
+            iface1 = link.iface1.id if link.iface1 else None
-                asym_links.append(link)
+            iface2 = link.iface2.id if link.iface2 else None
+            if link.node1_id < link.node2_id:
+                link_id = (link.node1_id, iface1, link.node2_id, iface2)
             else:
+                link_id = (link.node2_id, iface2, link.node1_id, iface1)
+            if link_id in known_links:
+                edit_links.append(link)
+            else:
+                known_links.add(link_id)
                 links.append(link)
         _, exceptions = grpcutils.create_links(session, links)
         if exceptions:
             exceptions = [str(x) for x in exceptions]
             return core_pb2.StartSessionResponse(result=False, exceptions=exceptions)
-        _, exceptions = grpcutils.edit_links(session, asym_links)
+        _, exceptions = grpcutils.edit_links(session, edit_links)
         if exceptions:
             exceptions = [str(x) for x in exceptions]
             return core_pb2.StartSessionResponse(result=False, exceptions=exceptions)

daemon/core/emulator/session.py

@@ -276,20 +276,22 @@ class Session:
                 ptp = self.create_node(PtpNet, start)
                 iface1 = node1.new_iface(ptp, iface1_data)
                 iface2 = node2.new_iface(ptp, iface2_data)
-                ptp.linkconfig(iface1, options)
+                iface1.config(options)
                 if not options.unidirectional:
-                    ptp.linkconfig(iface2, options)
+                    iface2.config(options)
             # link node to net
             elif isinstance(node1, CoreNodeBase) and isinstance(node2, CoreNetworkBase):
+                logger.info("linking node to net: %s - %s", node1.name, node2.name)
                 iface1 = node1.new_iface(node2, iface1_data)
                 if not isinstance(node2, (EmaneNet, WlanNode)):
-                    node2.linkconfig(iface1, options)
+                    iface1.config(options)
             # link net to node
             elif isinstance(node2, CoreNodeBase) and isinstance(node1, CoreNetworkBase):
+                logger.info("linking net to node: %s - %s", node1.name, node2.name)
                 iface2 = node2.new_iface(node1, iface2_data)
                 wireless_net = isinstance(node1, (EmaneNet, WlanNode))
                 if not options.unidirectional and not wireless_net:
-                    node1.linkconfig(iface2, options)
+                    iface2.config(options)
             # network to network
             elif isinstance(node1, CoreNetworkBase) and isinstance(
                 node2, CoreNetworkBase
@@ -298,11 +300,10 @@ class Session:
                     "linking network to network: %s - %s", node1.name, node2.name
                 )
                 iface1 = node1.linknet(node2)
-                node1.linkconfig(iface1, options)
+                use_local = iface1.net == node1
+                iface1.config(options, use_local=use_local)
                 if not options.unidirectional:
-                    iface1.swapparams("_params_up")
+                    iface1.config(options, use_local=not use_local)
-                    node2.linkconfig(iface1, options)
-                    iface1.swapparams("_params_up")
             else:
                 raise CoreError(
                     f"cannot link node1({type(node1)}) node2({type(node2)})"
@@ -379,16 +380,18 @@ class Session:
             elif isinstance(node1, CoreNetworkBase) and isinstance(
                 node2, CoreNetworkBase
             ):
-                for iface in node1.get_ifaces(control=False):
+                iface1 = node1.get_linked_iface(node2)
-                    if iface.othernet == node2:
+                if iface1:
-                        node1.detach(iface)
+                    node1.detach(iface1)
-                        iface.shutdown()
+                    iface1.shutdown()
-                        break
+                iface2 = node2.get_linked_iface(node1)
-                for iface in node2.get_ifaces(control=False):
+                if iface2:
-                    if iface.othernet == node1:
+                    node2.detach(iface2)
-                        node2.detach(iface)
+                    iface2.shutdown()
-                        iface.shutdown()
+                if not iface1 and not iface2:
-                        break
+                    raise CoreError(
+                        f"node1({node1.name}) and node2({node2.name}) are not connected"
+                    )
         self.sdt.delete_link(node1_id, node2_id)
 
     def update_link(
@@ -432,11 +435,11 @@ class Session:
         else:
             if isinstance(node1, CoreNodeBase) and isinstance(node2, CoreNodeBase):
                 iface1 = node1.ifaces.get(iface1_id)
-                iface2 = node2.ifaces.get(iface2_id)
                 if not iface1:
                     raise CoreError(
                         f"node({node1.name}) missing interface({iface1_id})"
                     )
+                iface2 = node2.ifaces.get(iface2_id)
                 if not iface2:
                     raise CoreError(
                         f"node({node2.name}) missing interface({iface2_id})"
@@ -446,39 +449,40 @@ class Session:
                         f"node1({node1.name}) node2({node2.name}) "
                         "not connected to same net"
                     )
-                ptp = iface1.net
+                iface1.config(options)
-                ptp.linkconfig(iface1, options, iface2)
                 if not options.unidirectional:
-                    ptp.linkconfig(iface2, options, iface1)
+                    iface2.config(options)
             elif isinstance(node1, CoreNodeBase) and isinstance(node2, CoreNetworkBase):
                 iface = node1.get_iface(iface1_id)
-                node2.linkconfig(iface, options)
+                if iface.net != node2:
+                    raise CoreError(
+                        f"node1({node1.name}) iface1({iface1_id})"
+                        f" is not linked to node1({node2.name})"
+                    )
+                iface.config(options)
             elif isinstance(node2, CoreNodeBase) and isinstance(node1, CoreNetworkBase):
                 iface = node2.get_iface(iface2_id)
-                node1.linkconfig(iface, options)
+                if iface.net != node1:
+                    raise CoreError(
+                        f"node2({node2.name}) iface2({iface2_id})"
+                        f" is not linked to node1({node1.name})"
+                    )
+                iface.config(options)
             elif isinstance(node1, CoreNetworkBase) and isinstance(
                 node2, CoreNetworkBase
             ):
                 iface = node1.get_linked_iface(node2)
-                upstream = False
                 if not iface:
-                    upstream = True
                     iface = node2.get_linked_iface(node1)
-                if not iface:
+                if iface:
-                    raise CoreError("modify unknown link between nets")
+                    use_local = iface.net == node1
-                if upstream:
+                    iface.config(options, use_local=use_local)
-                    iface.swapparams("_params_up")
-                    node1.linkconfig(iface, options)
-                    iface.swapparams("_params_up")
-                else:
-                    node1.linkconfig(iface, options)
                     if not options.unidirectional:
-                    if upstream:
+                        iface.config(options, use_local=not use_local)
-                        node2.linkconfig(iface, options)
                 else:
-                        iface.swapparams("_params_up")
+                    raise CoreError(
-                        node2.linkconfig(iface, options)
+                        f"node1({node1.name}) and node2({node2.name}) are not linked"
-                        iface.swapparams("_params_up")
+                    )
             else:
                 raise CoreError(
                     f"cannot update link node1({type(node1)}) node2({type(node2)})"

daemon/core/location/mobility.py

@@ -321,7 +321,7 @@ class BasicRangeModel(WirelessModel):
                     loss=self.loss,
                     jitter=self.jitter,
                 )
-                self.wlan.linkconfig(iface, options)
+                iface.config(options)
 
     def get_position(self, iface: CoreInterface) -> Tuple[float, float, float]:
         """

daemon/core/nodes/base.py

@@ -13,7 +13,7 @@ import netaddr
 
 from core import utils
 from core.configservice.dependencies import ConfigServiceDependencies
-from core.emulator.data import InterfaceData, LinkData, LinkOptions
+from core.emulator.data import InterfaceData, LinkData
 from core.emulator.enumerations import LinkTypes, MessageFlags, NodeTypes
 from core.errors import CoreCommandError, CoreError
 from core.executables import MOUNT, TEST, VNODED
@@ -1000,20 +1000,6 @@ class CoreNetworkBase(NodeBase):
         """
         raise NotImplementedError
 
-    @abc.abstractmethod
-    def linkconfig(
-        self, iface: CoreInterface, options: LinkOptions, iface2: CoreInterface = None
-    ) -> None:
-        """
-        Configure link parameters by applying tc queuing disciplines on the interface.
-
-        :param iface: interface one
-        :param options: options for configuring link
-        :param iface2: interface two
-        :return: nothing
-        """
-        raise NotImplementedError
-
     def custom_iface(self, node: CoreNode, iface_data: InterfaceData) -> CoreInterface:
         raise NotImplementedError
 

daemon/core/nodes/interface.py

@@ -3,6 +3,7 @@ virtual ethernet classes that implement the interfaces available under Linux.
 """
 
 import logging
+import math
 import time
 from pathlib import Path
 from typing import TYPE_CHECKING, Callable, Dict, List, Optional, Tuple
@@ -13,6 +14,7 @@ from core import utils
 from core.emulator.data import LinkOptions
 from core.emulator.enumerations import TransportType
 from core.errors import CoreCommandError, CoreError
+from core.executables import TC
 from core.nodes.netclient import LinuxNetClient, get_net_client
 
 logger = logging.getLogger(__name__)
@@ -336,6 +338,92 @@ class CoreInterface:
         """
         return self.transport_type == TransportType.VIRTUAL
 
+    def _set_params_change(self, **kwargs: float) -> bool:
+        """
+        Set parameters to change.
+
+        :param kwargs: parameter name and values to change
+        :return: True if any parameter changed, False otherwise
+        """
+        return any([self.setparam(k, v) for k, v in kwargs.items()])
+
+    def config(self, options: LinkOptions, use_local: bool = True) -> None:
+        """
+        Configure interface using tc based on existing state and provided
+        link options.
+
+        :param options: options to configure with
+        :param use_local: True to use localname for device, False for name
+        :return: nothing
+        """
+        # determine if any settings have changed
+        if use_local:
+            devname = self.localname
+            changed = self._set_params_change(
+                bw=options.bandwidth,
+                delay=options.delay,
+                loss=options.loss,
+                duplicate=options.dup,
+                jitter=options.jitter,
+                buffer=options.buffer,
+            )
+        else:
+            devname = self.name
+            changed = self._set_params_change(
+                n_bw=options.bandwidth,
+                n_delay=options.delay,
+                n_loss=options.loss,
+                n_duplicate=options.dup,
+                n_jitter=options.jitter,
+                n_buffer=options.buffer,
+            )
+        if not changed:
+            return
+        # delete tc configuration or create and add it
+        if all(
+            [
+                options.delay is None or options.delay <= 0,
+                options.jitter is None or options.jitter <= 0,
+                options.loss is None or options.loss <= 0,
+                options.dup is None or options.dup <= 0,
+                options.bandwidth is None or options.bandwidth <= 0,
+                options.buffer is None or options.buffer <= 0,
+            ]
+        ):
+            if not self.getparam("has_netem"):
+                return
+            if self.up:
+                cmd = f"{TC} qdisc delete dev {devname} root handle 10:"
+                self.host_cmd(cmd)
+            self.setparam("has_netem", False)
+        else:
+            netem = ""
+            if options.bandwidth is not None:
+                limit = 1000
+                bw = options.bandwidth / 1000
+                if options.buffer is not None and options.buffer > 0:
+                    limit = options.buffer
+                elif options.delay and options.bandwidth:
+                    delay = options.delay / 1000
+                    limit = max(2, math.ceil((2 * bw * delay) / (8 * self.mtu)))
+                netem += f" rate {bw}kbit"
+                netem += f" limit {limit}"
+            if options.delay is not None:
+                netem += f" delay {options.delay}us"
+            if options.jitter is not None:
+                if options.delay is None:
+                    netem += f" delay 0us {options.jitter}us 25%"
+                else:
+                    netem += f" {options.jitter}us 25%"
+            if options.loss is not None and options.loss > 0:
+                netem += f" loss {min(options.loss, 100)}%"
+            if options.dup is not None and options.dup > 0:
+                netem += f" duplicate {min(options.dup, 100)}%"
+            if self.up:
+                cmd = f"{TC} qdisc replace dev {devname} root handle 10: netem {netem}"
+                self.host_cmd(cmd)
+            self.setparam("has_netem", True)
+
 
 class Veth(CoreInterface):
     """

daemon/core/nodes/network.py

@@ -3,7 +3,6 @@ Defines network nodes used within core.
 """
 
 import logging
-import math
 import threading
 import time
 from collections import OrderedDict
@@ -14,7 +13,7 @@ from typing import TYPE_CHECKING, Dict, List, Optional, Type
 import netaddr
 
 from core import utils
-from core.emulator.data import InterfaceData, LinkData, LinkOptions
+from core.emulator.data import InterfaceData, LinkData
 from core.emulator.enumerations import (
     LinkTypes,
     MessageFlags,
@@ -23,7 +22,7 @@ from core.emulator.enumerations import (
     RegisterTlvs,
 )
 from core.errors import CoreCommandError, CoreError
-from core.executables import NFTABLES, TC
+from core.executables import NFTABLES
 from core.nodes.base import CoreNetworkBase
 from core.nodes.interface import CoreInterface, GreTap, Veth
 from core.nodes.netclient import get_net_client
@@ -400,77 +399,6 @@ class CoreNetwork(CoreNetworkBase):
             self.linked[iface1][iface2] = True
         nft_queue.update(self)
 
-    def linkconfig(
-        self, iface: CoreInterface, options: LinkOptions, iface2: CoreInterface = None
-    ) -> None:
-        """
-        Configure link parameters by applying tc queuing disciplines on the interface.
-
-        :param iface: interface one
-        :param options: options for configuring link
-        :param iface2: interface two
-        :return: nothing
-        """
-        # determine if any settings have changed
-        changed = any(
-            [
-                iface.setparam("bw", options.bandwidth),
-                iface.setparam("delay", options.delay),
-                iface.setparam("loss", options.loss),
-                iface.setparam("duplicate", options.dup),
-                iface.setparam("jitter", options.jitter),
-                iface.setparam("buffer", options.buffer),
-            ]
-        )
-        if not changed:
-            return
-
-        # delete tc configuration or create and add it
-        devname = iface.localname
-        if all(
-            [
-                options.delay is None or options.delay <= 0,
-                options.jitter is None or options.jitter <= 0,
-                options.loss is None or options.loss <= 0,
-                options.dup is None or options.dup <= 0,
-                options.bandwidth is None or options.bandwidth <= 0,
-                options.buffer is None or options.buffer <= 0,
-            ]
-        ):
-            if not iface.getparam("has_netem"):
-                return
-            if self.up:
-                cmd = f"{TC} qdisc delete dev {devname} root handle 10:"
-                iface.host_cmd(cmd)
-            iface.setparam("has_netem", False)
-        else:
-            netem = ""
-            if options.bandwidth is not None:
-                limit = 1000
-                bw = options.bandwidth / 1000
-                if options.buffer is not None and options.buffer > 0:
-                    limit = options.buffer
-                elif options.delay and options.bandwidth:
-                    delay = options.delay / 1000
-                    limit = max(2, math.ceil((2 * bw * delay) / (8 * iface.mtu)))
-                netem += f" rate {bw}kbit"
-                netem += f" limit {limit}"
-            if options.delay is not None:
-                netem += f" delay {options.delay}us"
-            if options.jitter is not None:
-                if options.delay is None:
-                    netem += f" delay 0us {options.jitter}us 25%"
-                else:
-                    netem += f" {options.jitter}us 25%"
-            if options.loss is not None and options.loss > 0:
-                netem += f" loss {min(options.loss, 100)}%"
-            if options.dup is not None and options.dup > 0:
-                netem += f" duplicate {min(options.dup, 100)}%"
-            if self.up:
-                cmd = f"{TC} qdisc replace dev {devname} root handle 10: netem {netem}"
-                iface.host_cmd(cmd)
-            iface.setparam("has_netem", True)
-
     def linknet(self, net: CoreNetworkBase) -> CoreInterface:
         """
         Link this bridge with another by creating a veth pair and installing

daemon/core/nodes/physical.py

@@ -7,14 +7,13 @@ import threading
 from pathlib import Path
 from typing import TYPE_CHECKING, List, Optional, Tuple
 
-from core.emulator.data import InterfaceData, LinkOptions
+from core.emulator.data import InterfaceData
 from core.emulator.distributed import DistributedServer
 from core.emulator.enumerations import NodeTypes, TransportType
 from core.errors import CoreCommandError, CoreError
 from core.executables import MOUNT, TEST, UMOUNT
 from core.nodes.base import CoreNetworkBase, CoreNodeBase
 from core.nodes.interface import DEFAULT_MTU, CoreInterface
-from core.nodes.network import CoreNetwork
 
 logger = logging.getLogger(__name__)
 
@@ -143,17 +142,6 @@ class PhysicalNode(CoreNodeBase):
         if self.up:
             self.net_client.device_up(iface.localname)
 
-    def linkconfig(
-        self, iface: CoreInterface, options: LinkOptions, iface2: CoreInterface = None
-    ) -> None:
-        """
-        Apply tc queing disciplines using linkconfig.
-        """
-        linux_bridge = CoreNetwork(self.session)
-        linux_bridge.up = True
-        linux_bridge.linkconfig(iface, options, iface2)
-        del linux_bridge
-
     def next_iface_id(self) -> int:
         with self.lock:
             while self.iface_id in self.ifaces:

daemon/tests/test_links.py

@@ -1,10 +1,19 @@
 from typing import Tuple
 
+import pytest
+
 from core.emulator.data import IpPrefixes, LinkOptions
 from core.emulator.session import Session
+from core.errors import CoreError
 from core.nodes.base import CoreNode
+from core.nodes.interface import CoreInterface
 from core.nodes.network import SwitchNode
 
+INVALID_ID: int = 100
+LINK_OPTIONS: LinkOptions = LinkOptions(
+    delay=50, bandwidth=5000000, loss=25, dup=25, jitter=10, buffer=100
+)
+
 
 def create_ptp_network(
     session: Session, ip_prefixes: IpPrefixes
@@ -24,8 +33,28 @@ def create_ptp_network(
     return node1, node2
 
 
+def check_iface_match(iface: CoreInterface, options: LinkOptions) -> bool:
+    result = iface.getparam("delay") == options.delay
+    result &= iface.getparam("bw") == options.bandwidth
+    result &= iface.getparam("loss") == options.loss
+    result &= iface.getparam("duplicate") == options.dup
+    result &= iface.getparam("jitter") == options.jitter
+    result &= iface.getparam("buffer") == options.buffer
+    return result
+
+
+def check_iface_diff(iface: CoreInterface, options: LinkOptions) -> bool:
+    result = iface.getparam("delay") != options.delay
+    result &= iface.getparam("bw") != options.bandwidth
+    result &= iface.getparam("loss") != options.loss
+    result &= iface.getparam("duplicate") != options.dup
+    result &= iface.getparam("jitter") != options.jitter
+    result &= iface.getparam("buffer") != options.buffer
+    return result
+
+
 class TestLinks:
-    def test_add_ptp(self, session: Session, ip_prefixes: IpPrefixes):
+    def test_add_node_to_node(self, session: Session, ip_prefixes: IpPrefixes):
         # given
         node1 = session.add_node(CoreNode)
         node2 = session.add_node(CoreNode)
@@ -33,11 +62,17 @@ class TestLinks:
         iface2_data = ip_prefixes.create_iface(node2)
 
         # when
-        session.add_link(node1.id, node2.id, iface1_data, iface2_data)
+        iface1, iface2 = session.add_link(
+            node1.id, node2.id, iface1_data, iface2_data, options=LINK_OPTIONS
+        )
 
         # then
         assert node1.get_iface(iface1_data.id)
         assert node2.get_iface(iface2_data.id)
+        assert iface1 is not None
+        assert iface2 is not None
+        assert check_iface_match(iface1, LINK_OPTIONS)
+        assert check_iface_match(iface2, LINK_OPTIONS)
 
     def test_add_node_to_net(self, session: Session, ip_prefixes: IpPrefixes):
         # given
@@ -46,11 +81,15 @@ class TestLinks:
         iface1_data = ip_prefixes.create_iface(node1)
 
         # when
-        session.add_link(node1.id, node2.id, iface1_data=iface1_data)
+        iface, _ = session.add_link(
+            node1.id, node2.id, iface1_data=iface1_data, options=LINK_OPTIONS
+        )
 
         # then
         assert node2.links()
         assert node1.get_iface(iface1_data.id)
+        assert iface is not None
+        assert check_iface_match(iface, LINK_OPTIONS)
 
     def test_add_net_to_node(self, session: Session, ip_prefixes: IpPrefixes):
         # given
@@ -59,11 +98,15 @@ class TestLinks:
         iface2_data = ip_prefixes.create_iface(node2)
 
         # when
-        session.add_link(node1.id, node2.id, iface2_data=iface2_data)
+        _, iface = session.add_link(
+            node1.id, node2.id, iface2_data=iface2_data, options=LINK_OPTIONS
+        )
 
         # then
         assert node1.links()
         assert node2.get_iface(iface2_data.id)
+        assert iface is not None
+        assert check_iface_match(iface, LINK_OPTIONS)
 
     def test_add_net_to_net(self, session):
         # given
@@ -71,147 +114,119 @@ class TestLinks:
         node2 = session.add_node(SwitchNode)
 
         # when
-        session.add_link(node1.id, node2.id)
+        iface, _ = session.add_link(node1.id, node2.id, options=LINK_OPTIONS)
 
         # then
         assert node1.links()
+        assert iface is not None
+        assert check_iface_match(iface, LINK_OPTIONS)
+
+    def test_add_node_to_node_uni(self, session: Session, ip_prefixes: IpPrefixes):
+        # given
+        node1 = session.add_node(CoreNode)
+        node2 = session.add_node(CoreNode)
+        iface1_data = ip_prefixes.create_iface(node1)
+        iface2_data = ip_prefixes.create_iface(node2)
+        link_options1 = LinkOptions(
+            delay=50,
+            bandwidth=5000000,
+            loss=25,
+            dup=25,
+            jitter=10,
+            buffer=100,
+            unidirectional=True,
+        )
+        link_options2 = LinkOptions(
+            delay=51,
+            bandwidth=5000001,
+            loss=26,
+            dup=26,
+            jitter=11,
+            buffer=101,
+            unidirectional=True,
+        )
+
+        # when
+        iface1, iface2 = session.add_link(
+            node1.id, node2.id, iface1_data, iface2_data, link_options1
+        )
+        session.update_link(
+            node2.id, node1.id, iface2_data.id, iface1_data.id, link_options2
+        )
+
+        # then
+        assert node1.get_iface(iface1_data.id)
+        assert node2.get_iface(iface2_data.id)
+        assert iface1 is not None
+        assert iface2 is not None
+        assert check_iface_match(iface1, link_options1)
+        assert check_iface_match(iface2, link_options2)
 
     def test_update_node_to_net(self, session: Session, ip_prefixes: IpPrefixes):
         # given
-        delay = 50
-        bandwidth = 5000000
-        loss = 25
-        dup = 25
-        jitter = 10
-        buffer = 100
         node1 = session.add_node(CoreNode)
         node2 = session.add_node(SwitchNode)
         iface1_data = ip_prefixes.create_iface(node1)
-        session.add_link(node1.id, node2.id, iface1_data)
+        iface1, _ = session.add_link(node1.id, node2.id, iface1_data)
-        iface1 = node1.get_iface(iface1_data.id)
+        assert check_iface_diff(iface1, LINK_OPTIONS)
-        assert iface1.getparam("delay") != delay
-        assert iface1.getparam("bw") != bandwidth
-        assert iface1.getparam("loss") != loss
-        assert iface1.getparam("duplicate") != dup
-        assert iface1.getparam("jitter") != jitter
-        assert iface1.getparam("buffer") != buffer
 
         # when
-        options = LinkOptions(
-            delay=delay,
-            bandwidth=bandwidth,
-            loss=loss,
-            dup=dup,
-            jitter=jitter,
-            buffer=buffer,
-        )
         session.update_link(
-            node1.id, node2.id, iface1_id=iface1_data.id, options=options
+            node1.id, node2.id, iface1_id=iface1_data.id, options=LINK_OPTIONS
         )
 
         # then
-        assert iface1.getparam("delay") == delay
+        assert check_iface_match(iface1, LINK_OPTIONS)
-        assert iface1.getparam("bw") == bandwidth
-        assert iface1.getparam("loss") == loss
-        assert iface1.getparam("duplicate") == dup
-        assert iface1.getparam("jitter") == jitter
-        assert iface1.getparam("buffer") == buffer
 
     def test_update_net_to_node(self, session: Session, ip_prefixes: IpPrefixes):
         # given
-        delay = 50
-        bandwidth = 5000000
-        loss = 25
-        dup = 25
-        jitter = 10
-        buffer = 100
         node1 = session.add_node(SwitchNode)
         node2 = session.add_node(CoreNode)
         iface2_data = ip_prefixes.create_iface(node2)
-        session.add_link(node1.id, node2.id, iface2_data=iface2_data)
+        _, iface2 = session.add_link(node1.id, node2.id, iface2_data=iface2_data)
-        iface2 = node2.get_iface(iface2_data.id)
+        assert check_iface_diff(iface2, LINK_OPTIONS)
-        assert iface2.getparam("delay") != delay
-        assert iface2.getparam("bw") != bandwidth
-        assert iface2.getparam("loss") != loss
-        assert iface2.getparam("duplicate") != dup
-        assert iface2.getparam("jitter") != jitter
-        assert iface2.getparam("buffer") != buffer
 
         # when
-        options = LinkOptions(
-            delay=delay,
-            bandwidth=bandwidth,
-            loss=loss,
-            dup=dup,
-            jitter=jitter,
-            buffer=buffer,
-        )
         session.update_link(
-            node1.id, node2.id, iface2_id=iface2_data.id, options=options
+            node1.id, node2.id, iface2_id=iface2_data.id, options=LINK_OPTIONS
         )
 
         # then
-        assert iface2.getparam("delay") == delay
+        assert check_iface_match(iface2, LINK_OPTIONS)
-        assert iface2.getparam("bw") == bandwidth
-        assert iface2.getparam("loss") == loss
-        assert iface2.getparam("duplicate") == dup
-        assert iface2.getparam("jitter") == jitter
-        assert iface2.getparam("buffer") == buffer
 
     def test_update_ptp(self, session: Session, ip_prefixes: IpPrefixes):
         # given
-        delay = 50
-        bandwidth = 5000000
-        loss = 25
-        dup = 25
-        jitter = 10
-        buffer = 100
         node1 = session.add_node(CoreNode)
         node2 = session.add_node(CoreNode)
         iface1_data = ip_prefixes.create_iface(node1)
         iface2_data = ip_prefixes.create_iface(node2)
-        session.add_link(node1.id, node2.id, iface1_data, iface2_data)
+        iface1, iface2 = session.add_link(node1.id, node2.id, iface1_data, iface2_data)
-        iface1 = node1.get_iface(iface1_data.id)
+        assert check_iface_diff(iface1, LINK_OPTIONS)
-        iface2 = node2.get_iface(iface2_data.id)
+        assert check_iface_diff(iface2, LINK_OPTIONS)
-        assert iface1.getparam("delay") != delay
-        assert iface1.getparam("bw") != bandwidth
-        assert iface1.getparam("loss") != loss
-        assert iface1.getparam("duplicate") != dup
-        assert iface1.getparam("jitter") != jitter
-        assert iface1.getparam("buffer") != buffer
-        assert iface2.getparam("delay") != delay
-        assert iface2.getparam("bw") != bandwidth
-        assert iface2.getparam("loss") != loss
-        assert iface2.getparam("duplicate") != dup
-        assert iface2.getparam("jitter") != jitter
-        assert iface2.getparam("buffer") != buffer
 
         # when
-        options = LinkOptions(
+        session.update_link(
-            delay=delay,
+            node1.id, node2.id, iface1_data.id, iface2_data.id, LINK_OPTIONS
-            bandwidth=bandwidth,
-            loss=loss,
-            dup=dup,
-            jitter=jitter,
-            buffer=buffer,
         )
-        session.update_link(node1.id, node2.id, iface1_data.id, iface2_data.id, options)
 
         # then
-        assert iface1.getparam("delay") == delay
+        assert check_iface_match(iface1, LINK_OPTIONS)
-        assert iface1.getparam("bw") == bandwidth
+        assert check_iface_match(iface2, LINK_OPTIONS)
-        assert iface1.getparam("loss") == loss
-        assert iface1.getparam("duplicate") == dup
-        assert iface1.getparam("jitter") == jitter
-        assert iface1.getparam("buffer") == buffer
-        assert iface2.getparam("delay") == delay
-        assert iface2.getparam("bw") == bandwidth
-        assert iface2.getparam("loss") == loss
-        assert iface2.getparam("duplicate") == dup
-        assert iface2.getparam("jitter") == jitter
-        assert iface2.getparam("buffer") == buffer
 
-    def test_delete_ptp(self, session: Session, ip_prefixes: IpPrefixes):
+    def test_update_net_to_net(self, session: Session, ip_prefixes: IpPrefixes):
+        # given
+        node1 = session.add_node(SwitchNode)
+        node2 = session.add_node(SwitchNode)
+        iface1, _ = session.add_link(node1.id, node2.id)
+        assert check_iface_diff(iface1, LINK_OPTIONS)
+
+        # when
+        session.update_link(node1.id, node2.id, options=LINK_OPTIONS)
+
+        # then
+        assert check_iface_match(iface1, LINK_OPTIONS)
+
+    def test_delete_node_to_node(self, session: Session, ip_prefixes: IpPrefixes):
         # given
         node1 = session.add_node(CoreNode)
         node2 = session.add_node(CoreNode)
@@ -255,3 +270,82 @@ class TestLinks:
 
         # then
         assert iface2_data.id not in node2.ifaces
+
+    def test_delete_net_to_net(self, session: Session, ip_prefixes: IpPrefixes):
+        # given
+        node1 = session.add_node(SwitchNode)
+        node2 = session.add_node(SwitchNode)
+        session.add_link(node1.id, node2.id)
+        assert node1.get_linked_iface(node2)
+
+        # when
+        session.delete_link(node1.id, node2.id)
+
+        # then
+        assert not node1.get_linked_iface(node2)
+
+    def test_delete_node_error(self, session: Session, ip_prefixes: IpPrefixes):
+        # given
+        node1 = session.add_node(SwitchNode)
+        node2 = session.add_node(SwitchNode)
+        session.add_link(node1.id, node2.id)
+        assert node1.get_linked_iface(node2)
+
+        # when
+        with pytest.raises(CoreError):
+            session.delete_link(node1.id, INVALID_ID)
+        with pytest.raises(CoreError):
+            session.delete_link(INVALID_ID, node2.id)
+
+    def test_delete_net_to_net_error(self, session: Session, ip_prefixes: IpPrefixes):
+        # given
+        node1 = session.add_node(SwitchNode)
+        node2 = session.add_node(SwitchNode)
+        node3 = session.add_node(SwitchNode)
+        session.add_link(node1.id, node2.id)
+        assert node1.get_linked_iface(node2)
+
+        # when
+        with pytest.raises(CoreError):
+            session.delete_link(node1.id, node3.id)
+
+    def test_delete_node_to_net_error(self, session: Session, ip_prefixes: IpPrefixes):
+        # given
+        node1 = session.add_node(CoreNode)
+        node2 = session.add_node(SwitchNode)
+        node3 = session.add_node(SwitchNode)
+        iface1_data = ip_prefixes.create_iface(node1)
+        iface1, _ = session.add_link(node1.id, node2.id, iface1_data)
+        assert iface1
+
+        # when
+        with pytest.raises(CoreError):
+            session.delete_link(node1.id, node3.id)
+
+    def test_delete_net_to_node_error(self, session: Session, ip_prefixes: IpPrefixes):
+        # given
+        node1 = session.add_node(SwitchNode)
+        node2 = session.add_node(CoreNode)
+        node3 = session.add_node(SwitchNode)
+        iface2_data = ip_prefixes.create_iface(node2)
+        _, iface2 = session.add_link(node1.id, node2.id, iface2_data=iface2_data)
+        assert iface2
+
+        # when
+        with pytest.raises(CoreError):
+            session.delete_link(node1.id, node3.id)
+
+    def test_delete_node_to_node_error(self, session: Session, ip_prefixes: IpPrefixes):
+        # given
+        node1 = session.add_node(CoreNode)
+        node2 = session.add_node(CoreNode)
+        node3 = session.add_node(SwitchNode)
+        iface1_data = ip_prefixes.create_iface(node1)
+        iface2_data = ip_prefixes.create_iface(node2)
+        iface1, iface2 = session.add_link(node1.id, node2.id, iface1_data, iface2_data)
+        assert iface1
+        assert iface2
+
+        # when
+        with pytest.raises(CoreError):
+            session.delete_link(node1.id, node3.id)