Plan reviewed with Codex; tried on a udev host (AlmaLinux 10) and a
netcf one (AlmaLinux 8).
- Changes are one change of the host's configuration (libvirt's
interface change transaction): a bridge that does not start used to
be undefined, leaving its member without the addresses and start
mode the bridge took from it; now the whole change rolls back, the
member's own configuration too, and so does a commit libvirt refuses.
A rollback that fails too is reported with the failure, saying the
host's configuration may be changed.
Deleting a bridge, which defines its
members again on their own, is one change as well.
- A running interface is not deleted: the page hid Delete, but a post
deleted it. A bridge with addresses and several members is refused
(which member takes the addresses is the user's choice); the
confirmation says that its members are defined again.
- A bridge takes only a device in no bridge, bond or VLAN as the host
has them configured, at any depth (a bridge's bond's devices), not
the loopback, a libvirt network's bridge or a VM's tap; an ethernet
interface configures only such a device too.
- Whether the host can change interfaces: unsupported or refused by
its access rules is a no, bad XML a yes, anything else (the
connection, the login) is raised instead of taken for a yes. A page
whose host could not be read offers no actions.
- Reads: the list reads each interface's XML once from one listing
(listAllInterfaces: every state, not the active and the defined ones
apart); a page reads the running and the saved definition once each
(cached_property). netcf writes a link speed of -1 for a card that
has none (a virtio one) and then refuses its own XML: the saved one
is read instead, where virsh and the page failed. Name and MAC come
from libvirt's object, without a call. Each family says how it is
addressed (DHCP, autoconf, static or none) and every address, its
prefix where it has one; no
address is not "DHCP" any more. A bridge's members carry their link
state and speed; an unknown speed (0, -1, 4294967295) is none.
- The interface API lists from the same reader. get_details,
get_bridge, get_bridge_slave_ifaces and the per-family getters go.
- The create form refuses a name the host already defines. Defining it
again replaced that interface's configuration, for example the host's
own uplink when a bridge was named after it.
- An interface that does not start is undefined again, so the name is
free for another try; the name check above makes this safe.
The form required a bridge member for an ethernet interface, which does
not use one. When the host's network devices could not be read, the error
was swallowed and every creation failed with "the device is not on this
host"; the page now shows the real error and does not try.
The IPv4 address and gateway were required even for DHCP or no IPv4, so
such an interface could not be created; malformed addresses passed and a
missing prefix crashed the XML builder. They are validated like the IPv6
fields now (netmask notation accepted, IPv6 scope ids rejected), and a
static address without a gateway gets no empty route. Interface names
follow the Linux rule (up to 15 letters, digits, . _ -). A bridge member,
or the device an ethernet interface configures, must be a device of the
host (the page no longer falls back to made-up names), a bridge cannot
contain itself, and needs STP and a non-negative delay.
The form checked both with re.match("^[0-9a-f./:]+|^$"), which tests
only how a value starts: "2001:db8::10/64'/><evil/>" passed and went
into the interface XML, which is built with f-strings, while upper-case
hex was refused. An address without a prefix passed too and then failed
with a ValueError when the XML was built.
The address is parsed with ipaddress.IPv6Interface and stored as
address/prefix (/128 when none is given), the gateway with
IPv6Address. A static configuration needs an address, and the XML gets
a route only when a gateway is given instead of gateway=''. The HTML
patterns accept upper-case hex.
Eight of the ten form and XML checks fail on the previous code.
