net/filter: Fix the output information for command 'info network'

The properties of netfilter object could be changed by 'qom-set'
command, but the output of 'info network' command is not updated,
because it got the old information through nf->info_str, it will
not be updated while we change the value of netfilter's property.

Here we split a helper function that could collect the output
information for filter, and also remove the useless member
'info_str' from struct NetFilterState.

Signed-off-by: zhanghailiang <zhang.zhanghailiang@huawei.com>
Cc: Jason Wang <jasowang@redhat.com>
Cc: Eric Blake <eblake@redhat.com>
Cc: Markus Armbruster <armbru@redhat.com>
Cc: Yang Hongyang <hongyang.yang@easystack.cn>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>

include/net/filter.h

@@ -55,7 +55,6 @@ struct NetFilterState {
     char *netdev_id;
     NetClientState *netdev;
     NetFilterDirection direction;
-    char info_str[256];
     QTAILQ_ENTRY(NetFilterState) next;
 };
 

net/filter.c

@@ -15,7 +15,6 @@
 #include "net/vhost_net.h"
 #include "qom/object_interfaces.h"
 #include "qemu/iov.h"
-#include "qapi/string-output-visitor.h"
 
 ssize_t qemu_netfilter_receive(NetFilterState *nf,
                                NetFilterDirection direction,
@@ -152,10 +151,6 @@ static void netfilter_complete(UserCreatable *uc, Error **errp)
     NetFilterClass *nfc = NETFILTER_GET_CLASS(uc);
     int queues;
     Error *local_err = NULL;
-    char *str, *info;
-    ObjectProperty *prop;
-    ObjectPropertyIterator iter;
-    StringOutputVisitor *ov;
 
     if (!nf->netdev_id) {
         error_setg(errp, "Parameter 'netdev' is required");
@@ -189,23 +184,6 @@ static void netfilter_complete(UserCreatable *uc, Error **errp)
         }
     }
     QTAILQ_INSERT_TAIL(&nf->netdev->filters, nf, next);
-
-    /* generate info str */
-    object_property_iter_init(&iter, OBJECT(nf));
-    while ((prop = object_property_iter_next(&iter))) {
-        if (!strcmp(prop->name, "type")) {
-            continue;
-        }
-        ov = string_output_visitor_new(false);
-        object_property_get(OBJECT(nf), string_output_get_visitor(ov),
-                            prop->name, errp);
-        str = string_output_get_string(ov);
-        string_output_visitor_cleanup(ov);
-        info = g_strdup_printf(",%s=%s", prop->name, str);
-        g_strlcat(nf->info_str, info, sizeof(nf->info_str));
-        g_free(str);
-        g_free(info);
-    }
 }
 
 static void netfilter_finalize(Object *obj)

net/net.c

@@ -45,6 +45,7 @@
 #include "qapi/dealloc-visitor.h"
 #include "sysemu/sysemu.h"
 #include "net/filter.h"
+#include "qapi/string-output-visitor.h"
 
 /* Net bridge is currently not supported for W32. */
 #if !defined(_WIN32)
@@ -1195,6 +1196,30 @@ void qmp_netdev_del(const char *id, Error **errp)
     qemu_opts_del(opts);
 }
 
+static void netfilter_print_info(Monitor *mon, NetFilterState *nf)
+{
+    char *str;
+    ObjectProperty *prop;
+    ObjectPropertyIterator iter;
+    StringOutputVisitor *ov;
+
+    /* generate info str */
+    object_property_iter_init(&iter, OBJECT(nf));
+    while ((prop = object_property_iter_next(&iter))) {
+        if (!strcmp(prop->name, "type")) {
+            continue;
+        }
+        ov = string_output_visitor_new(false);
+        object_property_get(OBJECT(nf), string_output_get_visitor(ov),
+                            prop->name, NULL);
+        str = string_output_get_string(ov);
+        string_output_visitor_cleanup(ov);
+        monitor_printf(mon, ",%s=%s", prop->name, str);
+        g_free(str);
+    }
+    monitor_printf(mon, "\n");
+}
+
 void print_net_client(Monitor *mon, NetClientState *nc)
 {
     NetFilterState *nf;
@@ -1208,9 +1233,10 @@ void print_net_client(Monitor *mon, NetClientState *nc)
     }
     QTAILQ_FOREACH(nf, &nc->filters, next) {
         char *path = object_get_canonical_path_component(OBJECT(nf));
-        monitor_printf(mon, "  - %s: type=%s%s\n", path,
+
-                       object_get_typename(OBJECT(nf)),
+        monitor_printf(mon, "  - %s: type=%s", path,
-                       nf->info_str);
+                       object_get_typename(OBJECT(nf)));
+        netfilter_print_info(mon, nf);
         g_free(path);
     }
 }