[Qemu-devel] [PATCH] net/filter-redirector:Add filter-redirector

[Zhang Chen <zhangchen.fnst@cn.fujitsu.com>]

From: ZhangChen <zhangchen.fnst@cn.fujitsu.com>

Filter-redirector is a netfilter plugin.
It gives qemu the ability to redirect net packet.
redirector can redirect filter's net packet to outdev.
and redirect indev's packet to filter.

                             filter
                               +
                               |
                               |
              redirector       |
               +-------------------------+
               |               |         |
               |               |         |
               |               |         |
  indev +----------------+     +---------------->  outdev
               |         |               |
               |         |               |
               |         |               |
               +-------------------------+
                         |
                         |
                         v
                      filter

usage:

-netdev tap,id=hn0
-chardev socket,id=s0,host=ip_primary,port=X,server,nowait
-chardev socket,id=s1,host=ip_primary,port=Y,server,nowait
-filter-redirector,id=r0,netdev=hn0,queue=tx/rx/all,indev=s0,outdev=s1

Signed-off-by: ZhangChen <zhangchen.fnst@cn.fujitsu.com>
Signed-off-by: Wen Congyang <wency@cn.fujitsu.com>
---
 net/Makefile.objs       |   1 +
 net/filter-redirector.c | 245 ++++++++++++++++++++++++++++++++++++++++++++++++
 qemu-options.hx         |   6 ++
 vl.c                    |   3 +-
 4 files changed, 254 insertions(+), 1 deletion(-)
 create mode 100644 net/filter-redirector.c

diff --git a/net/Makefile.objs b/net/Makefile.objs
index 5fa2f97..f4290a5 100644
--- a/net/Makefile.objs
+++ b/net/Makefile.objs
@@ -15,3 +15,4 @@ common-obj-$(CONFIG_VDE) += vde.o
 common-obj-$(CONFIG_NETMAP) += netmap.o
 common-obj-y += filter.o
 common-obj-y += filter-buffer.o
+common-obj-y += filter-redirector.o
diff --git a/net/filter-redirector.c b/net/filter-redirector.c
new file mode 100644
index 0000000..364e463
--- /dev/null
+++ b/net/filter-redirector.c
@@ -0,0 +1,245 @@
+/*
+ * Copyright (c) 2016 HUAWEI TECHNOLOGIES CO., LTD.
+ * Copyright (c) 2016 FUJITSU LIMITED
+ * Copyright (c) 2016 Intel Corporation
+ *
+ * Author: Zhang Chen <zhangchen.fnst@cn.fujitsu.com>
+ *
+ * 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 "net/filter.h"
+#include "net/net.h"
+#include "qemu-common.h"
+#include "qapi/qmp/qerror.h"
+#include "qapi-visit.h"
+#include "qom/object.h"
+#include "qemu/main-loop.h"
+#include "qemu/error-report.h"
+#include "trace.h"
+#include "sysemu/char.h"
+#include "qemu/iov.h"
+#include "qemu/sockets.h"
+
+#define FILTER_REDIRECTOR(obj) \
+    OBJECT_CHECK(RedirectorState, (obj), TYPE_FILTER_REDIRECTOR)
+
+#define TYPE_FILTER_REDIRECTOR "filter-redirector"
+#define REDIRECT_HEADER_LEN sizeof(uint32_t)
+
+typedef struct RedirectorState {
+    NetFilterState parent_obj;
+    NetQueue *incoming_queue;/* guest normal net queue */
+    char *indev;
+    char *outdev;
+    CharDriverState *chr_in;
+    CharDriverState *chr_out;
+} RedirectorState;
+
+static ssize_t filter_redirector_send(NetFilterState *nf,
+                                   const struct iovec *iov,
+                                   int iovcnt)
+{
+    RedirectorState *s = FILTER_REDIRECTOR(nf);
+    ssize_t ret = 0;
+    ssize_t size = 0;
+    uint32_t len =  0;
+    char *buf;
+
+    size = iov_size(iov, iovcnt);
+    len = htonl(size);
+    if (!size) {
+        return 0;
+    }
+
+    buf = g_malloc0(size);
+    iov_to_buf(iov, iovcnt, 0, buf, size);
+    ret = qemu_chr_fe_write_all(s->chr_out, (uint8_t *)&len, sizeof(len));
+    if (ret < 0) {
+        g_free(buf);
+        return ret;
+    }
+
+    ret = qemu_chr_fe_write_all(s->chr_out, (uint8_t *)buf, size);
+    g_free(buf);
+    return ret;
+}
+
+static ssize_t filter_redirector_receive_iov(NetFilterState *nf,
+                                         NetClientState *sender,
+                                         unsigned flags,
+                                         const struct iovec *iov,
+                                         int iovcnt,
+                                         NetPacketSent *sent_cb)
+{
+    RedirectorState *s = FILTER_REDIRECTOR(nf);
+    ssize_t ret = 0;
+
+    if (s->chr_out) {
+        ret = filter_redirector_send(nf, iov, iovcnt);
+        if (ret < 0) {
+            error_report("filter_redirector_send failed");
+        }
+    }
+    return iov_size(iov, iovcnt);
+}
+
+static void filter_redirector_cleanup(NetFilterState *nf)
+{
+    RedirectorState *s = FILTER_REDIRECTOR(nf);
+
+    if (s->chr_in) {
+        qemu_chr_fe_release(s->chr_in);
+    }
+    if (s->chr_out) {
+        qemu_chr_fe_release(s->chr_out);
+    }
+}
+
+static int redirector_chr_can_read(void *opaque)
+{
+    return REDIRECT_HEADER_LEN;
+}
+
+static void redirector_chr_read(void *opaque, const uint8_t *buf, int size)
+{
+    NetFilterState *nf = opaque;
+    RedirectorState *s = FILTER_REDIRECTOR(nf);
+    uint32_t len;
+    ssize_t ret = 0;
+    uint8_t *recv_buf;
+
+    if (size != REDIRECT_HEADER_LEN) {
+        // FIXME: do something else
+        error_report("packet is corruption, drop it");
+        return;
+    }
+    memcpy(&len, buf, sizeof(len));
+    len = ntohl(len);
+
+    if (len > 0 && len < NET_BUFSIZE) {
+        recv_buf = g_malloc0(len);
+        ret = qemu_chr_fe_read_all(s->chr_in, recv_buf, len);
+        if (ret != len) {
+            error_report("filter-redirector recv buf failed");
+            g_free(recv_buf);
+            return;
+        }
+
+        ret = qemu_net_queue_send(s->incoming_queue, nf->netdev,
+                            0, (const uint8_t *)recv_buf, len, NULL);
+        g_free(recv_buf);
+        if (ret < 0) {
+            error_report("filter-redirector out to guest failed");
+        }
+    } else {
+        error_report("filter-redirector recv len failed");
+    }
+}
+
+static void filter_redirector_setup(NetFilterState *nf, Error **errp)
+{
+    RedirectorState *s = FILTER_REDIRECTOR(nf);
+
+    if (!s->indev && !s->outdev) {
+        error_setg(errp, "filter redirector needs 'indev' or "
+                "'outdev' at least one property set");
+        return;
+    }
+
+    if (s->indev) {
+        s->chr_in = qemu_chr_find(s->indev);
+        if (s->chr_in == NULL) {
+            error_set(errp, ERROR_CLASS_DEVICE_NOT_FOUND,
+                      "IN Device '%s' not found", s->indev);
+            return;
+        }
+
+        qemu_chr_add_handlers(s->chr_in, redirector_chr_can_read,
+                              redirector_chr_read, NULL, nf);
+    }
+
+    if (s->outdev) {
+        s->chr_out = qemu_chr_find(s->outdev);
+        if (s->chr_out == NULL) {
+            error_set(errp, ERROR_CLASS_DEVICE_NOT_FOUND,
+                      "OUT Device '%s' not found", s->outdev);
+            return;
+        }
+    }
+    s->incoming_queue = qemu_new_net_queue(qemu_netfilter_pass_to_next, nf);
+}
+
+static void filter_redirector_class_init(ObjectClass *oc, void *data)
+{
+    NetFilterClass *nfc = NETFILTER_CLASS(oc);
+
+    nfc->setup = filter_redirector_setup;
+    nfc->cleanup = filter_redirector_cleanup;
+    nfc->receive_iov = filter_redirector_receive_iov;
+}
+
+static char *filter_redirector_get_indev(Object *obj, Error **errp)
+{
+    RedirectorState *s = FILTER_REDIRECTOR(obj);
+
+    return g_strdup(s->indev);
+}
+
+static void
+filter_redirector_set_indev(Object *obj, const char *value, Error **errp)
+{
+    RedirectorState *s = FILTER_REDIRECTOR(obj);
+
+    g_free(s->indev);
+    s->indev = g_strdup(value);
+}
+
+static char *filter_redirector_get_outdev(Object *obj, Error **errp)
+{
+    RedirectorState *s = FILTER_REDIRECTOR(obj);
+
+    return g_strdup(s->outdev);
+}
+
+static void
+filter_redirector_set_outdev(Object *obj, const char *value, Error **errp)
+{
+    RedirectorState *s = FILTER_REDIRECTOR(obj);
+
+    g_free(s->outdev);
+    s->outdev = g_strdup(value);
+}
+
+static void filter_redirector_init(Object *obj)
+{
+    object_property_add_str(obj, "indev", filter_redirector_get_indev,
+                            filter_redirector_set_indev, NULL);
+    object_property_add_str(obj, "outdev", filter_redirector_get_outdev,
+                            filter_redirector_set_outdev, NULL);
+}
+
+static void filter_redirector_fini(Object *obj)
+{
+    RedirectorState *s = FILTER_REDIRECTOR(obj);
+
+    g_free(s->indev);
+    g_free(s->outdev);
+}
+
+static const TypeInfo filter_redirector_info = {
+    .name = TYPE_FILTER_REDIRECTOR,
+    .parent = TYPE_NETFILTER,
+    .class_init = filter_redirector_class_init,
+    .instance_init = filter_redirector_init,
+    .instance_finalize = filter_redirector_fini,
+    .instance_size = sizeof(RedirectorState),
+};
+
+static void register_types(void)
+{
+    type_register_static(&filter_redirector_info);
+}
+
+type_init(register_types);
diff --git a/qemu-options.hx b/qemu-options.hx
index f31a240..1f796ed 100644
--- a/qemu-options.hx
+++ b/qemu-options.hx
@@ -3745,6 +3745,12 @@ queue @var{all|rx|tx} is an option that can be applied to any netfilter.
 @option{tx}: the filter is attached to the transmit queue of the netdev,
              where it will receive packets sent by the netdev.
 
+@item -object filter-redirector,id=@var{id},netdev=@var{netdevid},indev=@var{chardevid},outdev=@var{chardevid}[,queue=@var{all|rx|tx}]
+
+filter-redirector on netdev @var{netdevid},redirector can redirect filter's net packet to outdev.
+and redirect indev's packet to filter.
+queue @var{all|rx|tx} is an option that can be applied to filter-redirector.
+
 @item -object filter-dump,id=@var{id},netdev=@var{dev},file=@var{filename}][,maxlen=@var{len}]
 
 Dump the network traffic on netdev @var{dev} to the file specified by
diff --git a/vl.c b/vl.c
index f043009..4a9a9a0 100644
--- a/vl.c
+++ b/vl.c
@@ -2801,7 +2801,8 @@ static bool object_create_initial(const char *type)
      * they depend on netdevs already existing
      */
     if (g_str_equal(type, "filter-buffer") ||
-        g_str_equal(type, "filter-dump")) {
+        g_str_equal(type, "filter-dump") ||
+        g_str_equal(type, "filter-redirector")) {
         return false;
     }
 
-- 
1.9.1