IP Address validator

Returns True if there is at most one occurence of the ip_interface (an IPv4/IPv6 prefix+len)
in the entire config. That said, we need the 'iface_addresses' because VPP is a bit fickle in
this regard.

IP addresses from the same prefix/len can be added to a given interface (ie 192.0.2.1/24 and
192.0.2.2/24), but other than that, any prefix can not occur as a more-specific or less-specific
of any other interface.

So, we will allow:
- any ip_interface that is of equal network/len of existing one(s) _on the same interface_

And, we will reject
- any ip_interface that is a more specific of any existing one
- any ip_interface that is a less specific of any existing one

Update unit tests to ensure ip_interfaces are allowed in all cases.
This commit is contained in:
Pim van Pelt
2022-03-13 23:45:40 +00:00
parent 3f2b80172c
commit bb57ed8e52
9 changed files with 244 additions and 3 deletions

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@ -43,7 +43,7 @@ interfaces:
encapsulation:
dot1q: 1000
inner-dot1q: 1234
addresses: [ 192.0.2.1/24 ]
addresses: [ 192.168.1.1/24 ]
203:
encapsulation:
dot1ad: 1000

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@ -0,0 +1,32 @@
test:
description: "A bunch of IP addresses that are wellformed"
errors:
count: 0
---
interfaces:
GigabitEthernet1/0/0:
lcp: e0-0
addresses: [ 192.0.2.1/29, 2001:db8:1::1/64 ]
sub-interfaces:
100:
description: "Overlapping IP addresses are fine, if in the same prefix"
addresses: [ 192.0.2.9/29, 192.0.2.10/29 ]
101:
description: ".. and for IPv6 also, provided the same prefix is used"
addresses: [ 2001:db8:2::1/64, 2001:db8:2::2/64 ]
GigabitEthernet3/0/0:
mtu: 2000
loopbacks:
loop0:
lcp: "loop0"
addresses: [ 10.0.0.1/32, 2001:db8::1/128 ]
bridgedomains:
bd10:
description: "Bridge Domain 10"
mtu: 2000
lcp: "bvi10"
addresses: [ 10.0.0.2/32, 2001:db8::2/128 ]
interfaces: [ GigabitEthernet3/0/0 ]

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@ -48,7 +48,7 @@ interfaces:
encapsulation:
dot1q: 1000
inner-dot1q: 1234
addresses: [ 192.0.2.1/24 ]
addresses: [ 192.168.1.1/24 ]
203:
encapsulation:
dot1ad: 1000

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@ -0,0 +1,64 @@
test:
description: "IP interfaces cannot be more- or less-specific of any other interface"
errors:
expected:
- "interface .* IP address .* is not allowed"
- "sub-interface .* IP address .* is not allowed"
- "loopback .* IP address .* is not allowed"
- "bridgedomain .* IP address .* is not allowed"
count: 18
---
interfaces:
GigabitEthernet1/0/0:
lcp: e1-0-0
description: "The 2nd/3rd addresses all are more/less specifics of the first"
addresses: [ 172.16.12.1/29, 172.16.12.2/30, 172.16.12.3/28 ]
GigabitEthernet1/0/1:
lcp: e1-0-1
addresses: [ 192.0.2.1/29, 2001:db8:1::1/64 ]
sub-interfaces:
100:
description: "These addresses overlap with Gi1/0/1"
addresses: [ 192.0.2.2/29, 2001:db8:1::2/64 ]
101:
description: "These addresses overlap with loop0"
addresses: [ 192.0.2.10/29, 2001:db8:2::2/64 ]
GigabitEthernet1/0/2:
lcp: e0-2
description: "These addresses overlap with bd1"
addresses: [ 192.0.2.18/29, 2001:db8:3::2/64 ]
GigabitEthernet1/0/3:
lcp: e0-3
description: "These addresses are more-specific to Gi1/0/4"
addresses: [ 10.0.0.1/24, 2001:db8:3::1/64 ]
GigabitEthernet1/0/4:
lcp: e0-4
description: "These addresses are less-specific to Gi1/0/3"
addresses: [ 10.0.0.2/23, 2001:db8:3::2/60 ]
GigabitEthernet1/0/5:
lcp: e0-5
description: "These addresses are more-specific to Gi1/0/3"
addresses: [ 10.0.0.3/25, 2001:db8:3::3/112 ]
GigabitEthernet3/0/0:
description: "Bridge Domain bd1, member #1"
mtu: 2000
loopbacks:
loop0:
description: "These addresses overlap with Gi1/0/1.101"
lcp: "loop0"
addresses: [ 192.0.2.9/29, 2001:db8:2::1/64 ]
bridgedomains:
bd1:
description: "These addresses overlap with Gi1/0/2"
mtu: 2000
lcp: "bvi1"
addresses: [ 192.0.2.17/29, 2001:db8:3::1/64 ]
interfaces: [ GigabitEthernet3/0/0 ]

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@ -13,5 +13,5 @@ interfaces:
lcp: "xe2-0-0"
sub-interfaces:
100:
addresses: [ 192.0.2.1/24 ]
addresses: [ 192.168.1.1/24 ]

122
validator/address.py Normal file
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@ -0,0 +1,122 @@
#
# Copyright (c) 2022 Pim van Pelt
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at:
# http://www.apache.org/licenses/LICENSE-2.0
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
#
import logging
import validator.interface as interface
import ipaddress
def get_all_addresses_except_ifname(yaml, except_ifname):
""" Return a list of all ipaddress.ip_interface() instances in the entire config,
except for those that belong to 'ifname'.
"""
ret = []
if 'interfaces' in yaml:
for ifname, iface in yaml['interfaces'].items():
if ifname == except_ifname:
continue
if 'addresses' in iface:
for a in iface['addresses']:
ret.append(ipaddress.ip_interface(a))
if 'sub-interfaces' in iface:
for subid, sub_iface in iface['sub-interfaces'].items():
sub_ifname = "%s.%d" % (ifname, subid)
if sub_ifname == except_ifname:
continue
if 'addresses' in sub_iface:
for a in sub_iface['addresses']:
ret.append(ipaddress.ip_interface(a))
if 'loopbacks' in yaml:
for ifname, iface in yaml['loopbacks'].items():
if ifname == except_ifname:
continue
if 'addresses' in iface:
for a in iface['addresses']:
ret.append(ipaddress.ip_interface(a))
if 'bridgedomains' in yaml:
for ifname, iface in yaml['bridgedomains'].items():
if ifname == except_ifname:
continue
if 'addresses' in iface:
for a in iface['addresses']:
ret.append(ipaddress.ip_interface(a))
return ret
def is_allowed(yaml, ifname, iface_addresses, ip_interface):
""" Returns True if there is at most one occurence of the ip_interface (an IPv4/IPv6 prefix+len)
in the entire config. That said, we need the 'iface_addresses' because VPP is a bit fickle in
this regard.
IP addresses from the same prefix/len can be added to a given interface (ie 192.0.2.1/24 and
192.0.2.2/24), but other than that, any prefix can not occur as a more-specific or less-specific
of any other interface.
So, we will allow:
- any ip_interface that is of equal network/len of existing one(s) _on the same interface_
And, we will reject
- any ip_interface that is a more specific of any existing one
- any ip_interface that is a less specific of any existing one
Examples:
vpp# set interface ip address loop0 192.0.2.1/24
vpp# set interface ip address loop0 192.0.2.2/24
vpp# set interface ip address loop0 192.0.2.1/29
set interface ip address: failed to add 192.0.2.1/29 on loop0 which conflicts with 192.0.2.1/24 for interface loop0
vpp# set interface ip address loop0 192.0.2.3/23
set interface ip address: failed to add 192.0.2.3/23 on loop0 which conflicts with 192.0.2.1/24 for interface loop0
"""
## print("input: (%s,%s)" % (iface_addresses, ip_interface))
all_other_addresses = get_all_addresses_except_ifname(yaml, ifname)
## print("All IPs: %s" % all_other_addresses)
my_ip_network = ipaddress.ip_network(ip_interface, strict=False)
for ipi in all_other_addresses:
if ipi.version != my_ip_network.version:
continue
if ipaddress.ip_network(ipi, strict=False) == my_ip_network:
## print("Same: %s == %s" % (ip_interface, ipi))
return False
if ipaddress.ip_network(ipi, strict=False).subnet_of(my_ip_network):
## print("More: %s == %s" % (ip_interface, ipi))
return False
if my_ip_network.subnet_of(ipaddress.ip_network(ipi, strict=False)):
## print("Less: %s == %s" % (ip_interface, ipi))
return False
for ip in iface_addresses:
ipi = ipaddress.ip_interface(ip)
if ipi.version != my_ip_network.version:
continue
if ipaddress.ip_network(ipi, strict=False) == my_ip_network:
## print("iface same: %s == %s" % (ip_interface, ipi))
return True
if ipaddress.ip_network(ipi, strict=False).subnet_of(my_ip_network):
## print("iface more: %s == %s" % (ip_interface, ipi))
return False
if my_ip_network.subnet_of(ipaddress.ip_network(ipi, strict=False)):
## print("iface less: %s == %s" % (ip_interface, ipi))
return False
return True

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@ -14,6 +14,7 @@
import logging
import validator.interface as interface
import validator.lcp as lcp
import validator.address as address
class NullHandler(logging.Handler):
def emit(self, record):
@ -52,6 +53,11 @@ def validate_bridgedomains(yaml):
if 'lcp' in iface and not lcp.is_unique(yaml, iface['lcp']):
msgs.append("bridgedomain %s does not have a unique LCP name %s" % (ifname, iface['lcp']))
result = False
if 'addresses' in iface:
for a in iface['addresses']:
if not address.is_allowed(yaml, ifname, iface['addresses'], a):
msgs.append("bridgedomain %s IP address %s is not allowed" % (ifname, a))
result = False
if 'interfaces' in iface:
for member in iface['interfaces']:

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@ -14,6 +14,7 @@
import logging
import validator.bondethernet as bondethernet
import validator.lcp as lcp
import validator.address as address
class NullHandler(logging.Handler):
def emit(self, record):
@ -283,6 +284,12 @@ def validate_interfaces(yaml):
msgs.append("interface %s does not have a unique LCP name %s" % (ifname, iface_lcp))
result = False
if 'addresses' in iface:
for a in iface['addresses']:
if not address.is_allowed(yaml, ifname, iface['addresses'], a):
msgs.append("interface %s IP address %s is not allowed" % (ifname, a))
result = False
if has_sub(yaml, ifname):
for sub_id, sub_iface in yaml['interfaces'][ifname]['sub-interfaces'].items():
logger.debug("sub-interface %s" % sub_iface)
@ -312,6 +319,10 @@ def validate_interfaces(yaml):
if not iface_lcp:
msgs.append("sub-interface %s has an address but %s does not have LCP" % (sub_ifname, ifname))
result = False
for a in sub_iface['addresses']:
if not address.is_allowed(yaml, sub_ifname, sub_iface['addresses'], a):
msgs.append("sub-interface %s IP address %s is not allowed" % (sub_ifname, a))
result = False
if not valid_encapsulation(yaml, sub_ifname):
msgs.append("sub-interface %s has invalid encapsulation" % (sub_ifname))
result = False

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@ -13,6 +13,7 @@
#
import logging
import validator.lcp as lcp
import validator.address as address
class NullHandler(logging.Handler):
def emit(self, record):
@ -46,5 +47,10 @@ def validate_loopbacks(yaml):
if 'lcp' in iface and not lcp.is_unique(yaml, iface['lcp']):
msgs.append("loopback %s does not have a unique LCP name %s" % (ifname, iface['lcp']))
result = False
if 'addresses' in iface:
for a in iface['addresses']:
if not address.is_allowed(yaml, ifname, iface['addresses'], a):
msgs.append("loopback %s IP address %s is not allowed" % (ifname, a))
result = False
return result, msgs