creating ipv6 subnet with invalid gateway results in HttpException: 500

[Vlad Gridin]

[description]

Attempt to create an ipv6 subnet with a gateway address including prefix
results in 500 error returned by API.
Neutron-lib convert_ip_to_canonical_format [1] does not handle ValueError from netaddr.IPAddress

https://github.com/openstack/neutron-lib/blob/master/neutron_lib/api/converters.py#L214

[reproduceable]

always

[environment]

devstack all-in-one

[reproduction steps]

1. create a network
~/devstack$ openstack network create net1
+---------------------------+--------------------------------------+
| Field | Value |
+---------------------------+--------------------------------------+
| admin_state_up | UP |
| availability_zone_hints | |
| availability_zones | |
| created_at | 2018-12-07T13:10:55Z |
| description | |
| dns_domain | None |
| id | 47660b84-2511-4817-b08c-74a89e7ef3c9 |
| ipv4_address_scope | None |
| ipv6_address_scope | None |
| is_default | False |
| is_vlan_transparent | None |
| location | None |
| mtu | 1450 |
| name | net1 |
| port_security_enabled | True |
| project_id | d6023de2edcd48608cf040993889e26c |
| provider:network_type | vxlan |
| provider:physical_network | None |
| provider:segmentation_id | 61 |
| qos_policy_id | None |
| revision_number | 1 |
| router:external | Internal |
| segments | None |
| shared | False |
| status | ACTIVE |
| subnets | |
| tags | |
| updated_at | 2018-12-07T13:10:56Z |
+---------------------------+--------------------------------------+

2. create a subnet

~/devstack$ openstack subnet create --network net1 --ip-version 6 --subnet-range 2001:db8:0:1::/64 --gateway 2001:db8:0:1:1:1:1:1/128 subnet1
HttpException: 500: Server Error for url: https://10.30.19.81:9696/v2.0/subnets, Request Failed: internal server error while processing your request.

[expected result]

BadRequest Exception

[perceived severity]

low

[Vlad Gridin (vladyslav-gridin)]

possible fix:
https://review.openstack.org/#/c/623498/

[Rodolfo Alonso (rodolfo-alonso-hernandez)]

Hello Vlad:

I don't think this is a CLI error, but a user input error. If you review the documentation [1], three options are available for "gateway" parameter:
- IP address.
- "auto".
- "none".

A CIDR is not a valid input as a gateway parameter.

[1] https://docs.openstack.org/python-openstackclient/rocky/cli/command-objects/subnet.html

[Bence Romsics (bence-romsics)]

Rodolfo: As I read Vlad's report (especially the expected result part) I think he wants to see a 400 Bad Request instead of a 500 Internal Server Error. That seems valid to me.

[Vlad Gridin (vladyslav-gridin)]

Exactly, I do realize it is a invalid input. Returning Internal Server Error
by API is the part i am not happy with.

[Vlad Gridin (vladyslav-gridin)]

fwiw, same request with the fix above applied produces:

$ openstack subnet create --network net1 --ip-version 6 --subnet-range 2001:db8:0:1::/64 --gateway 2001:db8:0:1:1:1:1:1/128 subnet1
BadRequestException: 400: Client Error for url: https://10.30.19.81:9696/v2.0/subnets, Invalid input for gateway_ip. Reason: '2001:db8:0:1:1:1:1:1/128' is not a valid IP address.

[OpenStack Infra (hudson-openstack)]

Related fix proposed to branch: master
Review: https://review.openstack.org/623573

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/623498
Committed: https://git.openstack.org/cgit/openstack/neutron-lib/commit/?id=532b398b90fff1b224086b4eb52ac9ef7412a0f4
Submitter: Zuul
Branch: master

commit 532b398b90fff1b224086b4eb52ac9ef7412a0f4
Author: Vlad Gridin <email address hidden>
Date: Fri Dec 7 15:20:44 2018 +0100

    Handle ValueError in canonical address convertion

    netaddr.IPAddress raises ValueError for some unsupported
    address formats. This patch will catch this exception
    in addition to AddrFormatError.

    Closes-Bug: 1807394

    Change-Id: I06eea42906f1fe4443fa4959e79a1993a9664efe

[OpenStack Infra (hudson-openstack)]

This issue was fixed in the openstack/neutron-lib 1.22.0 release.

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/623573
Committed: https://git.openstack.org/cgit/openstack/neutron/commit/?id=98ef2ac8d6e75c56512d11377e3b9f9cadf7fe53
Submitter: Zuul
Branch: master

commit 98ef2ac8d6e75c56512d11377e3b9f9cadf7fe53
Author: Brian Haley <email address hidden>
Date: Fri Dec 7 15:01:00 2018 -0500

    Add some create subnet negative tests

    There were some edge cases that were untested that generate
    500 errors instead of 401's.

    Will need a neutron-lib version with
    https://review.openstack.org/#/c/623498/ in order to pass.

    Change-Id: I925476bc2515a1755364d92ab8d622d747a4a0fb
    Related-bug: #1807394