[Qemu-devel] [PATCH v11 02/12] init/cleanup of netfilter object

[Yang Hongyang]

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 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>
---
v11: no need to free nf->netdev_id, it will be auto freeed while object deleted
     remove global_list net_filters, will add back when needed
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            | 138 ++++++++++++++++++++++++++++++++++++++++++++++++
 net/net.c               |   7 +++
 qapi-schema.json        |  18 +++++++
 vl.c                    |  13 ++---
 8 files changed, 233 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..226f2f7
--- /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);
+
+struct NetFilterClass {
+    ObjectClass parent_class;
+
+    FilterSetup *setup;
+    FilterCleanup *cleanup;
+    FilterReceiveIOV *receive_iov;
+};
+typedef struct NetFilterClass NetFilterClass;
+
+
+struct NetFilterState {
+    /* private */
+    Object parent;
+
+    /* protected */
+    char *netdev_id;
+    NetClientState *netdev;
+    NetFilterChain chain;
+    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..3b810c8
--- /dev/null
+++ b/net/filter.c
@@ -0,0 +1,138 @@
+/*
+ * 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 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)
+{
+    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_finalize(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);
+    }
+}
+
+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(&nf->netdev->filters, nf, next);
+}
+
+static void netfilter_class_init(ObjectClass *oc, void *data)
+{
+    UserCreatableClass *ucc = USER_CREATABLE_CLASS(oc);
+
+    ucc->complete = netfilter_complete;
+}
+
+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_finalize,
+    .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..033f4f3 100644
--- a/net/net.c
+++ b/net/net.c
@@ -44,6 +44,7 @@
 #include "qapi/opts-visitor.h"
 #include "qapi/dealloc-visitor.h"
 #include "sysemu/sysemu.h"
+#include "net/filter.h"
 
 /* Net bridge is currently not supported for W32. */
 #if !defined(_WIN32)
@@ -287,6 +288,7 @@ 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 +386,7 @@ 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 +398,10 @@ 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 2bada60..546500a 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 066a080..ec589e2 100644
--- a/vl.c
+++ b/vl.c
@@ -2794,6 +2794,7 @@ static bool object_create_initial(const char *type)
     if (g_str_equal(type, "rng-egd")) {
         return false;
     }
+    /* TODO: return false for concrete netfilters */
     return true;
 }
 
@@ -4313,12 +4314,6 @@ 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)) {
@@ -4424,6 +4419,12 @@ 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);
-- 
1.9.1