net/filter.c

   1 /*
   2  * Copyright (c) 2015 FUJITSU LIMITED
   3  * Author: Yang Hongyang <yanghy@cn.fujitsu.com>
   4  *
   5  * This work is licensed under the terms of the GNU GPL, version 2 or
   6  * later.  See the COPYING file in the top-level directory.
   7  */
   8
   9 #include "qemu-common.h"
  10 #include "qapi/qmp/qerror.h"
  11 #include "qemu/error-report.h"
  12
  13 #include "net/filter.h"
  14 #include "net/net.h"
  15 #include "net/vhost_net.h"
  16 #include "qom/object_interfaces.h"
  17 #include "qemu/iov.h"
  18 #include "qapi/string-output-visitor.h"
  19
  20 ssize_t qemu_netfilter_receive(NetFilterState *nf,
  21                                NetFilterDirection direction,
  22                                NetClientState *sender,
  23                                unsigned flags,
  24                                const struct iovec *iov,
  25                                int iovcnt,
  26                                NetPacketSent *sent_cb)
  27 {
  28     if (nf->direction == direction ||
  29         nf->direction == NET_FILTER_DIRECTION_ALL) {
  30         return NETFILTER_GET_CLASS(OBJECT(nf))->receive_iov(
  31                                    nf, sender, flags, iov, iovcnt, sent_cb);
  32     }
  33
  34     return 0;
  35 }
  36
  37 ssize_t qemu_netfilter_pass_to_next(NetClientState *sender,
  38                                     unsigned flags,
  39                                     const struct iovec *iov,
  40                                     int iovcnt,
  41                                     void *opaque)
  42 {
  43     int ret = 0;
  44     int direction;
  45     NetFilterState *nf = opaque;
  46     NetFilterState *next = QTAILQ_NEXT(nf, next);
  47
  48     if (!sender || !sender->peer) {
  49         /* no receiver, or sender been deleted, no need to pass it further */
  50         goto out;
  51     }
  52
  53     if (nf->direction == NET_FILTER_DIRECTION_ALL) {
  54         if (sender == nf->netdev) {
  55             /* This packet is sent by netdev itself */
  56             direction = NET_FILTER_DIRECTION_TX;
  57         } else {
  58             direction = NET_FILTER_DIRECTION_RX;
  59         }
  60     } else {
  61         direction = nf->direction;
  62     }
  63
  64     while (next) {
  65         /*
  66          * if qemu_netfilter_pass_to_next been called, means that
  67          * the packet has been hold by filter and has already retured size
  68          * to the sender, so sent_cb shouldn't be called later, just
  69          * pass NULL to next.
  70          */
  71         ret = qemu_netfilter_receive(next, direction, sender, flags, iov,
  72                                      iovcnt, NULL);
  73         if (ret) {
  74             return ret;
  75         }
  76         next = QTAILQ_NEXT(next, next);
  77     }
  78
  79     /*
  80      * We have gone through all filters, pass it to receiver.
  81      * Do the valid check again incase sender or receiver been
  82      * deleted while we go through filters.
  83      */
  84     if (sender && sender->peer) {
  85         qemu_net_queue_send_iov(sender->peer->incoming_queue,
  86                                 sender, flags, iov, iovcnt, NULL);
  87     }
  88
  89 out:
  90     /* no receiver, or sender been deleted */
  91     return iov_size(iov, iovcnt);
  92 }
  93
  94 static char *netfilter_get_netdev_id(Object *obj, Error **errp)
  95 {
  96     NetFilterState *nf = NETFILTER(obj);
  97
  98     return g_strdup(nf->netdev_id);
  99 }
 100
 101 static void netfilter_set_netdev_id(Object *obj, const char *str, Error **errp)
 102 {
 103     NetFilterState *nf = NETFILTER(obj);
 104
 105     nf->netdev_id = g_strdup(str);
 106 }
 107
 108 static int netfilter_get_direction(Object *obj, Error **errp G_GNUC_UNUSED)
 109 {
 110     NetFilterState *nf = NETFILTER(obj);
 111     return nf->direction;
 112 }
 113
 114 static void netfilter_set_direction(Object *obj, int direction, Error **errp)
 115 {
 116     NetFilterState *nf = NETFILTER(obj);
 117     nf->direction = direction;
 118 }
 119
 120 static void netfilter_init(Object *obj)
 121 {
 122     object_property_add_str(obj, "netdev",
 123                             netfilter_get_netdev_id, netfilter_set_netdev_id,
 124                             NULL);
 125     object_property_add_enum(obj, "queue", "NetFilterDirection",
 126                              NetFilterDirection_lookup,
 127                              netfilter_get_direction, netfilter_set_direction,
 128                              NULL);
 129 }
 130
 131 static void netfilter_complete(UserCreatable *uc, Error **errp)
 132 {
 133     NetFilterState *nf = NETFILTER(uc);
 134     NetClientState *ncs[MAX_QUEUE_NUM];
 135     NetFilterClass *nfc = NETFILTER_GET_CLASS(uc);
 136     int queues;
 137     Error *local_err = NULL;
 138     char *str, *info;
 139     ObjectProperty *prop;
 140     StringOutputVisitor *ov;
 141
 142     if (!nf->netdev_id) {
 143         error_setg(errp, "Parameter 'netdev' is required");
 144         return;
 145     }
 146
 147     queues = qemu_find_net_clients_except(nf->netdev_id, ncs,
 148                                           NET_CLIENT_OPTIONS_KIND_NIC,
 149                                           MAX_QUEUE_NUM);
 150     if (queues < 1) {
 151         error_setg(errp, QERR_INVALID_PARAMETER_VALUE, "netdev",
 152                    "a network backend id");
 153         return;
 154     } else if (queues > 1) {
 155         error_setg(errp, "multiqueue is not supported");
 156         return;
 157     }
 158
 159     if (get_vhost_net(ncs[0])) {
 160         error_setg(errp, "Vhost is not supported");
 161         return;
 162     }
 163
 164     nf->netdev = ncs[0];
 165
 166     if (nfc->setup) {
 167         nfc->setup(nf, &local_err);
 168         if (local_err) {
 169             error_propagate(errp, local_err);
 170             return;
 171         }
 172     }
 173     QTAILQ_INSERT_TAIL(&nf->netdev->filters, nf, next);
 174
 175     /* generate info str */
 176     QTAILQ_FOREACH(prop, &OBJECT(nf)->properties, node) {
 177         if (!strcmp(prop->name, "type")) {
 178             continue;
 179         }
 180         ov = string_output_visitor_new(false);
 181         object_property_get(OBJECT(nf), string_output_get_visitor(ov),
 182                             prop->name, errp);
 183         str = string_output_get_string(ov);
 184         string_output_visitor_cleanup(ov);
 185         info = g_strdup_printf(",%s=%s", prop->name, str);
 186         g_strlcat(nf->info_str, info, sizeof(nf->info_str));
 187         g_free(str);
 188         g_free(info);
 189     }
 190 }
 191
 192 static void netfilter_finalize(Object *obj)
 193 {
 194     NetFilterState *nf = NETFILTER(obj);
 195     NetFilterClass *nfc = NETFILTER_GET_CLASS(obj);
 196
 197     if (nfc->cleanup) {
 198         nfc->cleanup(nf);
 199     }
 200
 201     if (nf->netdev && !QTAILQ_EMPTY(&nf->netdev->filters)) {
 202         QTAILQ_REMOVE(&nf->netdev->filters, nf, next);
 203     }
 204 }
 205
 206 static void netfilter_class_init(ObjectClass *oc, void *data)
 207 {
 208     UserCreatableClass *ucc = USER_CREATABLE_CLASS(oc);
 209
 210     ucc->complete = netfilter_complete;
 211 }
 212
 213 static const TypeInfo netfilter_info = {
 214     .name = TYPE_NETFILTER,
 215     .parent = TYPE_OBJECT,
 216     .abstract = true,
 217     .class_size = sizeof(NetFilterClass),
 218     .class_init = netfilter_class_init,
 219     .instance_size = sizeof(NetFilterState),
 220     .instance_init = netfilter_init,
 221     .instance_finalize = netfilter_finalize,
 222     .interfaces = (InterfaceInfo[]) {
 223         { TYPE_USER_CREATABLE },
 224         { }
 225     }
 226 };
 227
 228 static void register_types(void)
 229 {
 230     type_register_static(&netfilter_info);
 231 }
 232
 233 type_init(register_types);