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/osdep.h"
  10 #include "qapi/error.h"
  11 #include "qapi/qmp/qerror.h"
  12 #include "qemu/error-report.h"
  13
  14 #include "net/filter.h"
  15 #include "net/net.h"
  16 #include "net/vhost_net.h"
  17 #include "qom/object_interfaces.h"
  18 #include "qemu/iov.h"
  19 #include "qemu/module.h"
  20 #include "net/colo.h"
  21 #include "migration/colo.h"
  22
  23 static inline bool qemu_can_skip_netfilter(NetFilterState *nf)
  24 {
  25     return !nf->on;
  26 }
  27
  28 ssize_t qemu_netfilter_receive(NetFilterState *nf,
  29                                NetFilterDirection direction,
  30                                NetClientState *sender,
  31                                unsigned flags,
  32                                const struct iovec *iov,
  33                                int iovcnt,
  34                                NetPacketSent *sent_cb)
  35 {
  36     if (qemu_can_skip_netfilter(nf)) {
  37         return 0;
  38     }
  39     if (nf->direction == direction ||
  40         nf->direction == NET_FILTER_DIRECTION_ALL) {
  41         return NETFILTER_GET_CLASS(OBJECT(nf))->receive_iov(
  42                                    nf, sender, flags, iov, iovcnt, sent_cb);
  43     }
  44
  45     return 0;
  46 }
  47
  48 static NetFilterState *netfilter_next(NetFilterState *nf,
  49                                       NetFilterDirection dir)
  50 {
  51     NetFilterState *next;
  52
  53     if (dir == NET_FILTER_DIRECTION_TX) {
  54         /* forward walk through filters */
  55         next = QTAILQ_NEXT(nf, next);
  56     } else {
  57         /* reverse order */
  58         next = QTAILQ_PREV(nf, next);
  59     }
  60
  61     return next;
  62 }
  63
  64 ssize_t qemu_netfilter_pass_to_next(NetClientState *sender,
  65                                     unsigned flags,
  66                                     const struct iovec *iov,
  67                                     int iovcnt,
  68                                     void *opaque)
  69 {
  70     int ret = 0;
  71     int direction;
  72     NetFilterState *nf = opaque;
  73     NetFilterState *next = NULL;
  74
  75     if (!sender || !sender->peer) {
  76         /* no receiver, or sender been deleted, no need to pass it further */
  77         goto out;
  78     }
  79
  80     if (nf->direction == NET_FILTER_DIRECTION_ALL) {
  81         if (sender == nf->netdev) {
  82             /* This packet is sent by netdev itself */
  83             direction = NET_FILTER_DIRECTION_TX;
  84         } else {
  85             direction = NET_FILTER_DIRECTION_RX;
  86         }
  87     } else {
  88         direction = nf->direction;
  89     }
  90
  91     next = netfilter_next(nf, direction);
  92     while (next) {
  93         /*
  94          * if qemu_netfilter_pass_to_next has been called, it means that
  95          * the packet was held by  a filter and has already returned size
  96          * to the sender, so sent_cb shouldn't be called later, just
  97          * pass NULL to next.
  98          */
  99         ret = qemu_netfilter_receive(next, direction, sender, flags, iov,
 100                                      iovcnt, NULL);
 101         if (ret) {
 102             return ret;
 103         }
 104         next = netfilter_next(next, direction);
 105     }
 106
 107     /*
 108      * We have gone through all filters, pass it to receiver.
 109      * Do the valid check again in case sender or receiver been
 110      * deleted while we go through filters.
 111      */
 112     if (sender && sender->peer) {
 113         qemu_net_queue_send_iov(sender->peer->incoming_queue,
 114                                 sender, flags, iov, iovcnt, NULL);
 115     }
 116
 117 out:
 118     /* no receiver, or sender been deleted */
 119     return iov_size(iov, iovcnt);
 120 }
 121
 122 static char *netfilter_get_netdev_id(Object *obj, Error **errp)
 123 {
 124     NetFilterState *nf = NETFILTER(obj);
 125
 126     return g_strdup(nf->netdev_id);
 127 }
 128
 129 static void netfilter_set_netdev_id(Object *obj, const char *str, Error **errp)
 130 {
 131     NetFilterState *nf = NETFILTER(obj);
 132
 133     nf->netdev_id = g_strdup(str);
 134 }
 135
 136 static int netfilter_get_direction(Object *obj, Error **errp G_GNUC_UNUSED)
 137 {
 138     NetFilterState *nf = NETFILTER(obj);
 139     return nf->direction;
 140 }
 141
 142 static void netfilter_set_direction(Object *obj, int direction, Error **errp)
 143 {
 144     NetFilterState *nf = NETFILTER(obj);
 145     nf->direction = direction;
 146 }
 147
 148 static char *netfilter_get_status(Object *obj, Error **errp)
 149 {
 150     NetFilterState *nf = NETFILTER(obj);
 151
 152     return nf->on ? g_strdup("on") : g_strdup("off");
 153 }
 154
 155 static void netfilter_set_status(Object *obj, const char *str, Error **errp)
 156 {
 157     NetFilterState *nf = NETFILTER(obj);
 158     NetFilterClass *nfc = NETFILTER_GET_CLASS(obj);
 159
 160     if (strcmp(str, "on") && strcmp(str, "off")) {
 161         error_setg(errp, "Invalid value for netfilter status, "
 162                          "should be 'on' or 'off'");
 163         return;
 164     }
 165     if (nf->on == !strcmp(str, "on")) {
 166         return;
 167     }
 168     nf->on = !nf->on;
 169     if (nf->netdev && nfc->status_changed) {
 170         nfc->status_changed(nf, errp);
 171     }
 172 }
 173
 174 static char *netfilter_get_position(Object *obj, Error **errp)
 175 {
 176     NetFilterState *nf = NETFILTER(obj);
 177
 178     return g_strdup(nf->position);
 179 }
 180
 181 static void netfilter_set_position(Object *obj, const char *str, Error **errp)
 182 {
 183     NetFilterState *nf = NETFILTER(obj);
 184
 185     nf->position = g_strdup(str);
 186 }
 187
 188 static char *netfilter_get_insert(Object *obj, Error **errp)
 189 {
 190     NetFilterState *nf = NETFILTER(obj);
 191
 192     return nf->insert_before_flag ? g_strdup("before") : g_strdup("behind");
 193 }
 194
 195 static void netfilter_set_insert(Object *obj, const char *str, Error **errp)
 196 {
 197     NetFilterState *nf = NETFILTER(obj);
 198
 199     if (strcmp(str, "before") && strcmp(str, "behind")) {
 200         error_setg(errp, "Invalid value for netfilter insert, "
 201                          "should be 'before' or 'behind'");
 202         return;
 203     }
 204
 205     nf->insert_before_flag = !strcmp(str, "before");
 206 }
 207
 208 static void netfilter_init(Object *obj)
 209 {
 210     NetFilterState *nf = NETFILTER(obj);
 211
 212     nf->on = true;
 213     nf->insert_before_flag = false;
 214     nf->position = g_strdup("tail");
 215 }
 216
 217 static void netfilter_complete(UserCreatable *uc, Error **errp)
 218 {
 219     NetFilterState *nf = NETFILTER(uc);
 220     NetFilterState *position = NULL;
 221     NetClientState *ncs[MAX_QUEUE_NUM];
 222     NetFilterClass *nfc = NETFILTER_GET_CLASS(uc);
 223     int queues;
 224     Error *local_err = NULL;
 225
 226     if (!nf->netdev_id) {
 227         error_setg(errp, "Parameter 'netdev' is required");
 228         return;
 229     }
 230
 231     queues = qemu_find_net_clients_except(nf->netdev_id, ncs,
 232                                           NET_CLIENT_DRIVER_NIC,
 233                                           MAX_QUEUE_NUM);
 234     if (queues < 1) {
 235         error_setg(errp, QERR_INVALID_PARAMETER_VALUE, "netdev",
 236                    "a network backend id");
 237         return;
 238     } else if (queues > 1) {
 239         error_setg(errp, "multiqueue is not supported");
 240         return;
 241     }
 242
 243     if (get_vhost_net(ncs[0])) {
 244         error_setg(errp, "Vhost is not supported");
 245         return;
 246     }
 247
 248     if (strcmp(nf->position, "head") && strcmp(nf->position, "tail")) {
 249         Object *container;
 250         Object *obj;
 251         char *position_id;
 252
 253         if (!g_str_has_prefix(nf->position, "id=")) {
 254             error_setg(errp, QERR_INVALID_PARAMETER_VALUE, "position",
 255                        "'head', 'tail' or 'id=<id>'");
 256             return;
 257         }
 258
 259         /* get the id from the string */
 260         position_id = g_strndup(nf->position + 3, strlen(nf->position) - 3);
 261
 262         /* Search for the position to insert before/behind */
 263         container = object_get_objects_root();
 264         obj = object_resolve_path_component(container, position_id);
 265         if (!obj) {
 266             error_setg(errp, "filter '%s' not found", position_id);
 267             g_free(position_id);
 268             return;
 269         }
 270
 271         position = NETFILTER(obj);
 272
 273         if (position->netdev != ncs[0]) {
 274             error_setg(errp, "filter '%s' belongs to a different netdev",
 275                         position_id);
 276             g_free(position_id);
 277             return;
 278         }
 279
 280         g_free(position_id);
 281     }
 282
 283     nf->netdev = ncs[0];
 284
 285     if (nfc->setup) {
 286         nfc->setup(nf, &local_err);
 287         if (local_err) {
 288             error_propagate(errp, local_err);
 289             return;
 290         }
 291     }
 292
 293     if (position) {
 294         if (nf->insert_before_flag) {
 295             QTAILQ_INSERT_BEFORE(position, nf, next);
 296         } else {
 297             QTAILQ_INSERT_AFTER(&nf->netdev->filters, position, nf, next);
 298         }
 299     } else if (!strcmp(nf->position, "head")) {
 300         QTAILQ_INSERT_HEAD(&nf->netdev->filters, nf, next);
 301     } else if (!strcmp(nf->position, "tail")) {
 302         QTAILQ_INSERT_TAIL(&nf->netdev->filters, nf, next);
 303     }
 304 }
 305
 306 static void netfilter_finalize(Object *obj)
 307 {
 308     NetFilterState *nf = NETFILTER(obj);
 309     NetFilterClass *nfc = NETFILTER_GET_CLASS(obj);
 310
 311     if (nfc->cleanup) {
 312         nfc->cleanup(nf);
 313     }
 314
 315     if (nf->netdev && !QTAILQ_EMPTY(&nf->netdev->filters) &&
 316         QTAILQ_IN_USE(nf, next)) {
 317         QTAILQ_REMOVE(&nf->netdev->filters, nf, next);
 318     }
 319     g_free(nf->netdev_id);
 320     g_free(nf->position);
 321 }
 322
 323 static void default_handle_event(NetFilterState *nf, int event, Error **errp)
 324 {
 325     switch (event) {
 326     case COLO_EVENT_CHECKPOINT:
 327         break;
 328     case COLO_EVENT_FAILOVER:
 329         object_property_set_str(OBJECT(nf), "status", "off", errp);
 330         break;
 331     default:
 332         break;
 333     }
 334 }
 335
 336 static void netfilter_class_init(ObjectClass *oc, void *data)
 337 {
 338     UserCreatableClass *ucc = USER_CREATABLE_CLASS(oc);
 339     NetFilterClass *nfc = NETFILTER_CLASS(oc);
 340
 341     object_class_property_add_str(oc, "netdev",
 342                                   netfilter_get_netdev_id, netfilter_set_netdev_id);
 343     object_class_property_add_enum(oc, "queue", "NetFilterDirection",
 344                                    &NetFilterDirection_lookup,
 345                                    netfilter_get_direction, netfilter_set_direction);
 346     object_class_property_add_str(oc, "status",
 347                                   netfilter_get_status, netfilter_set_status);
 348     object_class_property_add_str(oc, "position",
 349                                   netfilter_get_position, netfilter_set_position);
 350     object_class_property_add_str(oc, "insert",
 351                                   netfilter_get_insert, netfilter_set_insert);
 352
 353     ucc->complete = netfilter_complete;
 354     nfc->handle_event = default_handle_event;
 355 }
 356
 357 static const TypeInfo netfilter_info = {
 358     .name = TYPE_NETFILTER,
 359     .parent = TYPE_OBJECT,
 360     .abstract = true,
 361     .class_size = sizeof(NetFilterClass),
 362     .class_init = netfilter_class_init,
 363     .instance_size = sizeof(NetFilterState),
 364     .instance_init = netfilter_init,
 365     .instance_finalize = netfilter_finalize,
 366     .interfaces = (InterfaceInfo[]) {
 367         { TYPE_USER_CREATABLE },
 368         { }
 369     }
 370 };
 371
 372 static void register_types(void)
 373 {
 374     type_register_static(&netfilter_info);
 375 }
 376
 377 type_init(register_types);