MAINTAINERS: Replace net maintainer Mark McLoughlin with Stefan Hajnoczi

The net subsystem has lacked an active maintainer since 2009.  I have
built and tested a net-next tree to get the ball rolling again.

Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
qapi: fix error propagation

Don't overwrite / leak previously set errors.
Make traversal cope with missing mandatory sub-structs.
Don't try to end a container that could not be started.

v1->v2:
- unchanged

v2->v3:
- instead of examining, assert that we never overwrite errors with
  error_set()
- allow visitors to set a NULL struct pointer successfully, so traversal
  of incomplete objects can continue
- check for a NULL "obj" before accessing "(*obj)->has_XXX" (this is not a
  typo, "obj != NULL" implies "*obj != NULL" here)
- fix start_struct / end_struct balance for unions as well

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
qapi: add test case for deallocating traversal of incomplete structure

v3:
- new patch

Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
qapi: generate C types for fixed-width integers

(Long line folded using parens:
<http://www.python.org/dev/peps/pep-0008/#maximum-line-length>.)

Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
qapi: introduce "size" type

v1->v2:
- fall back to uint64 rather than int

Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
expose QemuOpt and QemuOpts struct definitions to interested parties

The only clients should be the existent "qemu-option.c", and the upcoming
"qapi/opts-visitor.c".

Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
qapi: introduce OptsVisitor

This visitor supports parsing

  -option [type=]discriminator[,optarg1=val1][,optarg2=val2][,...]

style QemuOpts objects into "native" C structures. After defining the type
tree in the qapi schema (see below), a root type traversal with this
visitor linked to the underlying QemuOpts object will build the "native" C
representation of the option.

The type tree in the schema, corresponding to an option with a
discriminator, must have the following structure:

  struct
    scalar member for non-discriminated optarg 1 [*]
    list for repeating non-discriminated optarg 2 [*]
      wrapper struct
        single scalar member
    union
      struct for discriminator case 1
        scalar member for optarg 3 [*]
        list for repeating optarg 4 [*]
          wrapper struct
            single scalar member
        scalar member for optarg 5 [*]
      struct for discriminator case 2
        ...

The "type" optarg name is fixed for the discriminator role. Its schema
representation is "union of structures", and each discriminator value must
correspond to a member name in the union.

If the option takes no "type" descriminator, then the type subtree rooted
at the union must be absent from the schema (including the union itself).

Optarg values can be of scalar types str / bool / integers / size.

Members marked with [*] may be defined as optional in the schema,
describing an optional optarg.

Repeating an optarg is supported; its schema representation must be "list
of structure with single mandatory scalar member". If an optarg is not
described as repeating in the schema (ie. it is defined as a scalar field
instead of a list), its last occurrence will take effect. Ordering between
differently named optargs is not preserved.

A mandatory list (or an optional one which is reported to be available),
corresponding to a repeating optarg, has at least one element after
successful parsing.

v1->v2:
- Update opts_type_size() prototype to uint64_t.
- Add opts_type_uint64() for options needing the full uint64_t range.
  (Internals could be extracted to "cutils.c".)
- Allow negative values in opts_type_int().
- Rebase to nested Makefiles.

v2->v3:
- Factor opts_visitor_insert() out of opts_start_struct() and call it
  separately for opts_root->id if there's any.
- Don't require non-negative values in opts_type_int()'s error message.
- g_malloc0() may return NULL for zero-sized requests. Support empty
  structures by requesting 1 byte for them instead.

Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
qapi schema: remove trailing whitespace

Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
qapi schema: add Netdev types

NetdevTapOptions::sndbuf and NetdevDumpOptions::len use the new "size"
type.

v1->v2:
- NetLegacy::name is optional
- NetLegacyNicOptions::vectors is of type uint32
- NetdevVdeOptions::port and ::mode are of type uint16
- NetLegacy::vlan has type int32

v2->v3:
- NetLegacy::id is allowed and takes precedence over NetLegacy::name
- replace "@traits" with "@opts" in NetLegacy & Netdev descriptions

Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
hw, net: "net_client_type" -> "NetClientOptionsKind" (qapi-generated)

NET_CLIENT_TYPE_ -> NET_CLIENT_OPTIONS_KIND_

Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
convert net_client_init() to OptsVisitor

The net_client_init() prototype is kept intact.

Based on "is_netdev", the QemuOpts-rooted QemuOpt-list is parsed as a
Netdev or a NetLegacy. The original meat of net_client_init() is moved to
and simplified in net_client_init1():

Fields not common between -net and -netdev are clearly separated. Getting
the name for the init functions is cleaner: Netdev::id is mandatory, and
all init functions handle a NULL NetLegacy::name. NetLegacy::vlan
explicitly depends on -net (see below).

Verifying the "type=" option for -netdev can be turned into a switch.

Format validation with qemu_opts_validate() can be removed because the
visitor covers it. Relatedly, the "net_client_types" array is reduced to
an array of init functions that can be directly indexed by opts->kind.
(Help text is available in the schema JSON.)

The outermost negation in the condition around qemu_find_vlan() was
flattened, because it expresses the dependent code's requirements more
clearly.

VLAN lookup is avoided if there's no init function to pass the VLAN to.

Whenever the value of type=... is needed, we substitute
NetClientOptionsKind_lookup[kind].

The individual init functions are not converted yet, thus the original
QemuOpts instance is passed transparently.

v1->v2:
- NetLegacy::name is optional. Tracked it through all init functions: they
  all handle a NULL name. Updated commit message accordingly.

v2->v3:
- NetLegacy::id is allowed and takes precedence over NetLegacy::name.

Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
convert net_init_nic() to NetClientOptions

v1->v2:
- NetLegacyNicOptions::vectors is of type uint32

Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
convert net_init_dump() to NetClientOptions

v1->v2:
- NetdevDumpOptions::len is of type 'size', whose C type was changed to
  uint64_t. Adapt the printf() format specifier macro.

Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
convert net_init_slirp() to NetClientOptions

Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
convert net_init_socket() to NetClientOptions

I "reverse engineered" the following permissions between the -socket
sub-options:

             fd  listen  connect  mcast  udp | localaddr
  fd         x   .       .        .      .   | .
  listen     .   x       .        .      .   | .
  connect    .   .       x        .      .   | .
  mcast      .   .       .        x      .   | x
  udp        .   .       .        .      x   | x
  -------------------------------------------+
  localaddr  .   .       .        x      x     x

I transformed the code accordingly. The real fix would be to embed "fd",
"listen", "connect", "mcast" and "udp" in a separate union. However
OptsVisitor's enum parser only supports the type=XXX QemuOpt instance as
union discriminator.

Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
convert net_init_vde() to NetClientOptions

v1->v2:
- NetdevVdeOptions::port and ::mode are of type uint16. Remove superfluous
  range checks.

Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
convert net_init_tap() to NetClientOptions

Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
convert net_init_bridge() to NetClientOptions

Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
remove unused QemuOpts parameter from net init functions

v1->v2:
- unchanged

v2->v3:
- keep "qemu-option.h" included in "net/slirp.h"

Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>