Re: [Qemu-devel] [PATCH v10 02/10] init/cleanup of netfilter object

[Jason Wang]

On 09/09/2015 03:24 PM, Yang Hongyang wrote:
> Add a netfilter object based on QOM.
>
> A netfilter is attached to a netdev, captures all network packets
> that pass through the netdev. When we delete the netdev, we also
> delete the netfilter object attached to it, because if the netdev is
> removed, the filter which attached to it is useless.
>
> QTAILQ_ENTRY global_list but used by filter layer, so that we can
> manage all filters together.

This list is not used in this series. Maybe you could either remove it
or document its future usage.

> QTAILQ_ENTRY next used by netdev, filter belongs to the specific netdev is
> in this queue.
>
> Also init delayed object after net_init_clients, because netfilters need
> to be initialized after net clients initialized.
>
> Signed-off-by: Yang Hongyang <address@hidden>
> ---
> v10: use QOM for netfilter
> v9: use flat union instead of simple union in QAPI schema
> v8: include vhost_net header
> v7: add check for vhost
>     fix error propagate bug
> v6: add multiqueue support (net_filter_init1)
> v5: remove model from NetFilterState
>     add a sent_cb param to receive_iov API
> ---
>  include/net/filter.h    |  60 +++++++++++++++++++
>  include/net/net.h       |   1 +
>  include/qemu/typedefs.h |   1 +
>  net/Makefile.objs       |   1 +
>  net/filter.c            | 153 
> ++++++++++++++++++++++++++++++++++++++++++++++++
>  net/net.c               |   6 ++
>  qapi-schema.json        |  18 ++++++
>  vl.c                    |  13 ++--
>  8 files changed, 247 insertions(+), 6 deletions(-)
>  create mode 100644 include/net/filter.h
>  create mode 100644 net/filter.c
>
> diff --git a/include/net/filter.h b/include/net/filter.h
> new file mode 100644
> index 0000000..4557cb9
> --- /dev/null
> +++ b/include/net/filter.h
> @@ -0,0 +1,60 @@
> +/*
> + * Copyright (c) 2015 FUJITSU LIMITED
> + * Author: Yang Hongyang <address@hidden>
> + *
> + * This work is licensed under the terms of the GNU GPL, version 2 or
> + * later.  See the COPYING file in the top-level directory.
> + */
> +
> +#ifndef QEMU_NET_FILTER_H
> +#define QEMU_NET_FILTER_H
> +
> +#include "qom/object.h"
> +#include "qemu-common.h"
> +#include "qemu/typedefs.h"
> +#include "net/queue.h"
> +
> +#define TYPE_NETFILTER "netfilter"
> +#define NETFILTER(obj) \
> +    OBJECT_CHECK(NetFilterState, (obj), TYPE_NETFILTER)
> +#define NETFILTER_GET_CLASS(obj) \
> +    OBJECT_GET_CLASS(NetFilterClass, (obj), TYPE_NETFILTER)
> +#define NETFILTER_CLASS(klass) \
> +    OBJECT_CLASS_CHECK(NetFilterClass, (klass), TYPE_NETFILTER)
> +
> +typedef void (FilterSetup) (NetFilterState *nf, Error **errp);
> +typedef void (FilterCleanup) (NetFilterState *nf);
> +/*
> + * Return:
> + *   0: finished handling the packet, we should continue
> + *   size: filter stolen this packet, we stop pass this packet further
> + */
> +typedef ssize_t (FilterReceiveIOV)(NetFilterState *nc,
> +                                   NetClientState *sender,
> +                                   unsigned flags,
> +                                   const struct iovec *iov,
> +                                   int iovcnt,
> +                                   NetPacketSent *sent_cb);
> +
> +typedef struct NetFilterClass {
> +    ObjectClass parent_class;
> +
> +    FilterSetup *setup;
> +    FilterCleanup *cleanup;
> +    FilterReceiveIOV *receive_iov;
> +} NetFilterClass;
> +
> +
> +struct NetFilterState {
> +    /* private */
> +    Object parent;
> +
> +    /* protected */
> +    char *netdev_id;
> +    NetClientState *netdev;
> +    NetFilterChain chain;
> +    QTAILQ_ENTRY(NetFilterState) global_list;
> +    QTAILQ_ENTRY(NetFilterState) next;
> +};
> +
> +#endif /* QEMU_NET_FILTER_H */
> diff --git a/include/net/net.h b/include/net/net.h
> index 6a6cbef..36e5fab 100644
> --- a/include/net/net.h
> +++ b/include/net/net.h
> @@ -92,6 +92,7 @@ struct NetClientState {
>      NetClientDestructor *destructor;
>      unsigned int queue_index;
>      unsigned rxfilter_notify_enabled:1;
> +    QTAILQ_HEAD(, NetFilterState) filters;
>  };
>  
>  typedef struct NICState {
> diff --git a/include/qemu/typedefs.h b/include/qemu/typedefs.h
> index f8a9dd6..2c0648f 100644
> --- a/include/qemu/typedefs.h
> +++ b/include/qemu/typedefs.h
> @@ -45,6 +45,7 @@ typedef struct Monitor Monitor;
>  typedef struct MouseTransformInfo MouseTransformInfo;
>  typedef struct MSIMessage MSIMessage;
>  typedef struct NetClientState NetClientState;
> +typedef struct NetFilterState NetFilterState;
>  typedef struct NICInfo NICInfo;
>  typedef struct PcGuestInfo PcGuestInfo;
>  typedef struct PCIBridge PCIBridge;
> diff --git a/net/Makefile.objs b/net/Makefile.objs
> index ec19cb3..914aec0 100644
> --- a/net/Makefile.objs
> +++ b/net/Makefile.objs
> @@ -13,3 +13,4 @@ common-obj-$(CONFIG_HAIKU) += tap-haiku.o
>  common-obj-$(CONFIG_SLIRP) += slirp.o
>  common-obj-$(CONFIG_VDE) += vde.o
>  common-obj-$(CONFIG_NETMAP) += netmap.o
> +common-obj-y += filter.o
> diff --git a/net/filter.c b/net/filter.c
> new file mode 100644
> index 0000000..5192c6d
> --- /dev/null
> +++ b/net/filter.c
> @@ -0,0 +1,153 @@
> +/*
> + * Copyright (c) 2015 FUJITSU LIMITED
> + * Author: Yang Hongyang <address@hidden>
> + *
> + * This work is licensed under the terms of the GNU GPL, version 2 or
> + * later.  See the COPYING file in the top-level directory.
> + */
> +
> +#include "qemu-common.h"
> +#include "qapi/qmp/qerror.h"
> +#include "qemu/error-report.h"
> +
> +#include "net/filter.h"
> +#include "net/net.h"
> +#include "net/vhost_net.h"
> +#include "qom/object_interfaces.h"
> +
> +static QTAILQ_HEAD(, NetFilterState) net_filters;
> +
> +static char *netfilter_get_netdev_id(Object *obj, Error **errp)
> +{
> +    NetFilterState *nf = NETFILTER(obj);
> +
> +    return g_strdup(nf->netdev_id);
> +}
> +
> +static void netfilter_set_netdev_id(Object *obj, const char *str, Error 
> **errp)
> +{
> +    NetFilterState *nf = NETFILTER(obj);
> +
> +    nf->netdev_id = g_strdup(str);
> +}
> +
> +static int netfilter_get_chain(Object *obj, Error **errp G_GNUC_UNUSED)
> +{
> +    NetFilterState *nf = NETFILTER(obj);
> +    return nf->chain;
> +}
> +
> +static void netfilter_set_chain(Object *obj, int chain, Error **errp)
> +{
> +    NetFilterState *nf = NETFILTER(obj);
> +    nf->chain = chain;
> +}
> +
> +static void netfilter_init(Object *obj)
> +{
> +    QTAILQ_INIT(&net_filters);
> +    object_property_add_str(obj, "netdev",
> +                            netfilter_get_netdev_id, netfilter_set_netdev_id,
> +                            NULL);
> +    object_property_add_enum(obj, "chain", "NetFilterChain",
> +                             NetFilterChain_lookup,
> +                             netfilter_get_chain, netfilter_set_chain,
> +                             NULL);
> +}
> +
> +static void netfilter_cleanup(Object *obj)
> +{
> +    NetFilterState *nf = NETFILTER(obj);
> +    NetFilterClass *nfc = NETFILTER_GET_CLASS(obj);
> +
> +    if (nfc->cleanup) {
> +        nfc->cleanup(nf);
> +    }
> +
> +    if (nf->netdev && !QTAILQ_EMPTY(&nf->netdev->filters)) {
> +        QTAILQ_REMOVE(&nf->netdev->filters, nf, next);
> +    }
> +    if (!QTAILQ_EMPTY(&net_filters)) {
> +        QTAILQ_REMOVE(&net_filters, nf, global_list);
> +    }
> +
> +    g_free(nf->netdev_id);
> +}
> +
> +static void netfilter_complete(UserCreatable *uc, Error **errp)
> +{
> +    NetFilterState *nf = NETFILTER(uc);
> +    NetClientState *ncs[MAX_QUEUE_NUM];
> +    NetFilterClass *nfc = NETFILTER_GET_CLASS(uc);
> +    int queues;
> +    Error *local_err = NULL;
> +
> +    if (!nf->netdev_id) {
> +        error_setg(errp, "Parameter 'netdev' is required");
> +        return;
> +    }
> +
> +    queues = qemu_find_net_clients_except(nf->netdev_id, ncs,
> +                                          NET_CLIENT_OPTIONS_KIND_NIC,
> +                                          MAX_QUEUE_NUM);
> +    if (queues < 1) {
> +        error_setg(errp, QERR_INVALID_PARAMETER_VALUE, "netdev",
> +                   "a network backend id");
> +        return;
> +    } else if (queues > 1) {
> +        error_setg(errp, "Multi queue is not supported");
> +        return;
> +    }
> +
> +    if (get_vhost_net(ncs[0])) {
> +        error_setg(errp, "Vhost is not supported");
> +        return;
> +    }
> +
> +    nf->netdev = ncs[0];
> +
> +    if (nfc->setup) {
> +        nfc->setup(nf, &local_err);
> +        if (local_err) {
> +            error_propagate(errp, local_err);
> +            return;
> +        }
> +    }
> +    QTAILQ_INSERT_TAIL(&net_filters, nf, global_list);
> +    QTAILQ_INSERT_TAIL(&nf->netdev->filters, nf, next);
> +}
> +
> +static bool netfilter_can_be_deleted(UserCreatable *uc, Error **errp)
> +{
> +    return true;
> +}
> +
> +static void netfilter_class_init(ObjectClass *oc, void *data)
> +{
> +    UserCreatableClass *ucc = USER_CREATABLE_CLASS(oc);
> +
> +    ucc->complete = netfilter_complete;
> +    ucc->can_be_deleted = netfilter_can_be_deleted;
> +}
> +
> +static const TypeInfo netfilter_info = {
> +    .name = TYPE_NETFILTER,
> +    .parent = TYPE_OBJECT,
> +    .abstract = true,
> +    .class_size = sizeof(NetFilterClass),
> +    .class_init = netfilter_class_init,
> +    .instance_size = sizeof(NetFilterState),
> +    .instance_init = netfilter_init,
> +    .instance_finalize = netfilter_cleanup,
> +    .interfaces = (InterfaceInfo[]) {
> +        { TYPE_USER_CREATABLE },
> +        { }
> +    }
> +};
> +
> +static void register_types(void)
> +{
> +    type_register_static(&netfilter_info);
> +}
> +
> +type_init(register_types);
> diff --git a/net/net.c b/net/net.c
> index 28a5597..d6d4db8 100644
> --- a/net/net.c
> +++ b/net/net.c
> @@ -287,6 +287,7 @@ static void qemu_net_client_setup(NetClientState *nc,
>  
>      nc->incoming_queue = qemu_new_net_queue(nc);
>      nc->destructor = destructor;
> +    QTAILQ_INIT(&nc->filters);
>  }
>  
>  NetClientState *qemu_new_net_client(NetClientInfo *info,
> @@ -384,6 +385,7 @@ void qemu_del_net_client(NetClientState *nc)
>  {
>      NetClientState *ncs[MAX_QUEUE_NUM];
>      int queues, i;
> +    NetFilterState *nf, *next;
>  
>      assert(nc->info->type != NET_CLIENT_OPTIONS_KIND_NIC);
>  
> @@ -395,6 +397,10 @@ void qemu_del_net_client(NetClientState *nc)
>                                            MAX_QUEUE_NUM);
>      assert(queues != 0);
>  
> +    QTAILQ_FOREACH_SAFE(nf, &nc->filters, next, next) {
> +        object_unparent(OBJECT(nf));
> +    }
> +
>      /* If there is a peer NIC, delete and cleanup client, but do not free. */
>      if (nc->peer && nc->peer->info->type == NET_CLIENT_OPTIONS_KIND_NIC) {
>          NICState *nic = qemu_get_nic(nc->peer);
> diff --git a/qapi-schema.json b/qapi-schema.json
> index 67fef37..068e89e 100644
> --- a/qapi-schema.json
> +++ b/qapi-schema.json
> @@ -2551,6 +2551,24 @@
>      'opts': 'NetClientOptions' } }
>  
>  ##
> +# @NetFilterChain
> +#
> +# netfilter chain, a netfilter is attached to a netdev, captures the
> +# network packets of the netdev.
> +#
> +# @all: the filter will receive packets both sent to/from the netdev, this
> +#       is the default chain.
> +#
> +# @in: the filter will receive packets sent to the netdev.
> +#
> +# @out: the filter will receive packets sent from the netdev.
> +#
> +# Since 2.5
> +##
> +{ 'enum': 'NetFilterChain',
> +  'data': [ 'all', 'in', 'out' ] }
> +
> +##
>  # @InetSocketAddress
>  #
>  # Captures a socket address or address range in the Internet namespace.
> diff --git a/vl.c b/vl.c
> index 584ca88..672f8b2 100644
> --- a/vl.c
> +++ b/vl.c
> @@ -2783,6 +2783,7 @@ static bool object_create_initial(const char *type)
>      if (g_str_equal(type, "rng-egd")) {
>          return false;
>      }
> +    /* TODO: reture false for concrete netfilters */
>      return true;
>  }
>  
> @@ -4302,12 +4303,6 @@ int main(int argc, char **argv, char **envp)
>          exit(0);
>      }
>  
> -    if (qemu_opts_foreach(qemu_find_opts("object"),
> -                          object_create,
> -                          object_create_delayed, NULL)) {
> -        exit(1);
> -    }
> -
>      machine_opts = qemu_get_machine_opts();
>      if (qemu_opt_foreach(machine_opts, machine_set_property, current_machine,
>                           NULL)) {
> @@ -4413,6 +4408,12 @@ int main(int argc, char **argv, char **envp)
>          exit(1);
>      }
>  
> +    if (qemu_opts_foreach(qemu_find_opts("object"),
> +                          object_create,
> +                          object_create_delayed, NULL)) {
> +        exit(1);
> +    }
> +
>  #ifdef CONFIG_TPM
>      if (tpm_init() < 0) {
>          exit(1);