net/filter-mirror.c

   1 /*
   2  * Copyright (c) 2016 HUAWEI TECHNOLOGIES CO., LTD.
   3  * Copyright (c) 2016 FUJITSU LIMITED
   4  * Copyright (c) 2016 Intel Corporation
   5  *
   6  * Author: Zhang Chen <[email protected]>
   7  *
   8  * This work is licensed under the terms of the GNU GPL, version 2 or
   9  * later.  See the COPYING file in the top-level directory.
  10  */
  11
  12 #include "qemu/osdep.h"
  13 #include "net/filter.h"
  14 #include "net/net.h"
  15 #include "qemu-common.h"
  16 #include "qapi/error.h"
  17 #include "qapi/qmp/qerror.h"
  18 #include "qapi-visit.h"
  19 #include "qom/object.h"
  20 #include "qemu/main-loop.h"
  21 #include "qemu/error-report.h"
  22 #include "trace.h"
  23 #include "sysemu/char.h"
  24 #include "qemu/iov.h"
  25 #include "qemu/sockets.h"
  26
  27 #define FILTER_MIRROR(obj) \
  28     OBJECT_CHECK(MirrorState, (obj), TYPE_FILTER_MIRROR)
  29
  30 #define FILTER_REDIRECTOR(obj) \
  31     OBJECT_CHECK(MirrorState, (obj), TYPE_FILTER_REDIRECTOR)
  32
  33 #define TYPE_FILTER_MIRROR "filter-mirror"
  34 #define TYPE_FILTER_REDIRECTOR "filter-redirector"
  35 #define REDIRECTOR_MAX_LEN NET_BUFSIZE
  36
  37 typedef struct MirrorState {
  38     NetFilterState parent_obj;
  39     char *indev;
  40     char *outdev;
  41     CharDriverState *chr_in;
  42     CharDriverState *chr_out;
  43     int state; /* 0 = getting length, 1 = getting data */
  44     unsigned int index;
  45     unsigned int packet_len;
  46     uint8_t buf[REDIRECTOR_MAX_LEN];
  47 } MirrorState;
  48
  49 static int filter_mirror_send(CharDriverState *chr_out,
  50                               const struct iovec *iov,
  51                               int iovcnt)
  52 {
  53     int ret = 0;
  54     ssize_t size = 0;
  55     uint32_t len =  0;
  56     char *buf;
  57
  58     size = iov_size(iov, iovcnt);
  59     if (!size) {
  60         return 0;
  61     }
  62
  63     len = htonl(size);
  64     ret = qemu_chr_fe_write_all(chr_out, (uint8_t *)&len, sizeof(len));
  65     if (ret != sizeof(len)) {
  66         goto err;
  67     }
  68
  69     buf = g_malloc(size);
  70     iov_to_buf(iov, iovcnt, 0, buf, size);
  71     ret = qemu_chr_fe_write_all(chr_out, (uint8_t *)buf, size);
  72     g_free(buf);
  73     if (ret != size) {
  74         goto err;
  75     }
  76
  77     return 0;
  78
  79 err:
  80     return ret < 0 ? ret : -EIO;
  81 }
  82
  83 static void
  84 redirector_to_filter(NetFilterState *nf, const uint8_t *buf, int len)
  85 {
  86     struct iovec iov = {
  87         .iov_base = (void *)buf,
  88         .iov_len = len,
  89     };
  90
  91     if (nf->direction == NET_FILTER_DIRECTION_ALL ||
  92         nf->direction == NET_FILTER_DIRECTION_TX) {
  93         qemu_netfilter_pass_to_next(nf->netdev, 0, &iov, 1, nf);
  94     }
  95
  96     if (nf->direction == NET_FILTER_DIRECTION_ALL ||
  97         nf->direction == NET_FILTER_DIRECTION_RX) {
  98         qemu_netfilter_pass_to_next(nf->netdev->peer, 0, &iov, 1, nf);
  99      }
 100 }
 101
 102 static int redirector_chr_can_read(void *opaque)
 103 {
 104     return REDIRECTOR_MAX_LEN;
 105 }
 106
 107 static void redirector_chr_read(void *opaque, const uint8_t *buf, int size)
 108 {
 109     NetFilterState *nf = opaque;
 110     MirrorState *s = FILTER_REDIRECTOR(nf);
 111     unsigned int l;
 112
 113     while (size > 0) {
 114         /* reassemble a packet from the network */
 115         switch (s->state) { /* 0 = getting length, 1 = getting data */
 116         case 0:
 117             l = 4 - s->index;
 118             if (l > size) {
 119                 l = size;
 120             }
 121             memcpy(s->buf + s->index, buf, l);
 122             buf += l;
 123             size -= l;
 124             s->index += l;
 125             if (s->index == 4) {
 126                 /* got length */
 127                 s->packet_len = ntohl(*(uint32_t *)s->buf);
 128                 s->index = 0;
 129                 s->state = 1;
 130             }
 131             break;
 132         case 1:
 133             l = s->packet_len - s->index;
 134             if (l > size) {
 135                 l = size;
 136             }
 137             if (s->index + l <= sizeof(s->buf)) {
 138                 memcpy(s->buf + s->index, buf, l);
 139             } else {
 140                 error_report("serious error: oversized packet received.");
 141                 s->index = s->state = 0;
 142                 qemu_chr_add_handlers(s->chr_in, NULL, NULL, NULL, NULL);
 143                 return;
 144             }
 145
 146             s->index += l;
 147             buf += l;
 148             size -= l;
 149             if (s->index >= s->packet_len) {
 150                 s->index = 0;
 151                 s->state = 0;
 152                 redirector_to_filter(nf, s->buf, s->packet_len);
 153             }
 154             break;
 155         }
 156     }
 157 }
 158
 159 static void redirector_chr_event(void *opaque, int event)
 160 {
 161     NetFilterState *nf = opaque;
 162     MirrorState *s = FILTER_REDIRECTOR(nf);
 163
 164     switch (event) {
 165     case CHR_EVENT_CLOSED:
 166         qemu_chr_add_handlers(s->chr_in, NULL, NULL, NULL, NULL);
 167         break;
 168     default:
 169         break;
 170     }
 171 }
 172
 173 static ssize_t filter_mirror_receive_iov(NetFilterState *nf,
 174                                          NetClientState *sender,
 175                                          unsigned flags,
 176                                          const struct iovec *iov,
 177                                          int iovcnt,
 178                                          NetPacketSent *sent_cb)
 179 {
 180     MirrorState *s = FILTER_MIRROR(nf);
 181     int ret;
 182
 183     ret = filter_mirror_send(s->chr_out, iov, iovcnt);
 184     if (ret) {
 185         error_report("filter_mirror_send failed(%s)", strerror(-ret));
 186     }
 187
 188     /*
 189      * we don't hope this error interrupt the normal
 190      * path of net packet, so we always return zero.
 191      */
 192     return 0;
 193 }
 194
 195 static ssize_t filter_redirector_receive_iov(NetFilterState *nf,
 196                                              NetClientState *sender,
 197                                              unsigned flags,
 198                                              const struct iovec *iov,
 199                                              int iovcnt,
 200                                              NetPacketSent *sent_cb)
 201 {
 202     MirrorState *s = FILTER_REDIRECTOR(nf);
 203     int ret;
 204
 205     if (s->chr_out) {
 206         ret = filter_mirror_send(s->chr_out, iov, iovcnt);
 207         if (ret) {
 208             error_report("filter_mirror_send failed(%s)", strerror(-ret));
 209         }
 210         return iov_size(iov, iovcnt);
 211     } else {
 212         return 0;
 213     }
 214 }
 215
 216 static void filter_mirror_cleanup(NetFilterState *nf)
 217 {
 218     MirrorState *s = FILTER_MIRROR(nf);
 219
 220     if (s->chr_out) {
 221         qemu_chr_fe_release(s->chr_out);
 222     }
 223 }
 224
 225 static void filter_redirector_cleanup(NetFilterState *nf)
 226 {
 227     MirrorState *s = FILTER_REDIRECTOR(nf);
 228
 229     if (s->chr_in) {
 230         qemu_chr_add_handlers(s->chr_in, NULL, NULL, NULL, NULL);
 231         qemu_chr_fe_release(s->chr_in);
 232     }
 233     if (s->chr_out) {
 234         qemu_chr_fe_release(s->chr_out);
 235     }
 236 }
 237
 238 static void filter_mirror_setup(NetFilterState *nf, Error **errp)
 239 {
 240     MirrorState *s = FILTER_MIRROR(nf);
 241
 242     if (!s->outdev) {
 243         error_setg(errp, "filter filter mirror needs 'outdev' "
 244                    "property set");
 245         return;
 246     }
 247
 248     s->chr_out = qemu_chr_find(s->outdev);
 249     if (s->chr_out == NULL) {
 250         error_set(errp, ERROR_CLASS_DEVICE_NOT_FOUND,
 251                   "Device '%s' not found", s->outdev);
 252         return;
 253     }
 254
 255     if (qemu_chr_fe_claim(s->chr_out) != 0) {
 256         error_setg(errp, QERR_DEVICE_IN_USE, s->outdev);
 257         return;
 258     }
 259 }
 260
 261 static void filter_redirector_setup(NetFilterState *nf, Error **errp)
 262 {
 263     MirrorState *s = FILTER_REDIRECTOR(nf);
 264
 265     if (!s->indev && !s->outdev) {
 266         error_setg(errp, "filter redirector needs 'indev' or "
 267                    "'outdev' at least one property set");
 268         return;
 269     } else if (s->indev && s->outdev) {
 270         if (!strcmp(s->indev, s->outdev)) {
 271             error_setg(errp, "'indev' and 'outdev' could not be same "
 272                        "for filter redirector");
 273             return;
 274         }
 275     }
 276
 277     s->state = s->index = 0;
 278
 279     if (s->indev) {
 280         s->chr_in = qemu_chr_find(s->indev);
 281         if (s->chr_in == NULL) {
 282             error_set(errp, ERROR_CLASS_DEVICE_NOT_FOUND,
 283                       "IN Device '%s' not found", s->indev);
 284             return;
 285         }
 286
 287         qemu_chr_fe_claim_no_fail(s->chr_in);
 288         qemu_chr_add_handlers(s->chr_in, redirector_chr_can_read,
 289                               redirector_chr_read, redirector_chr_event, nf);
 290     }
 291
 292     if (s->outdev) {
 293         s->chr_out = qemu_chr_find(s->outdev);
 294         if (s->chr_out == NULL) {
 295             error_set(errp, ERROR_CLASS_DEVICE_NOT_FOUND,
 296                       "OUT Device '%s' not found", s->outdev);
 297             return;
 298         }
 299         qemu_chr_fe_claim_no_fail(s->chr_out);
 300     }
 301 }
 302
 303 static void filter_mirror_class_init(ObjectClass *oc, void *data)
 304 {
 305     NetFilterClass *nfc = NETFILTER_CLASS(oc);
 306
 307     nfc->setup = filter_mirror_setup;
 308     nfc->cleanup = filter_mirror_cleanup;
 309     nfc->receive_iov = filter_mirror_receive_iov;
 310 }
 311
 312 static void filter_redirector_class_init(ObjectClass *oc, void *data)
 313 {
 314     NetFilterClass *nfc = NETFILTER_CLASS(oc);
 315
 316     nfc->setup = filter_redirector_setup;
 317     nfc->cleanup = filter_redirector_cleanup;
 318     nfc->receive_iov = filter_redirector_receive_iov;
 319 }
 320
 321 static char *filter_redirector_get_indev(Object *obj, Error **errp)
 322 {
 323     MirrorState *s = FILTER_REDIRECTOR(obj);
 324
 325     return g_strdup(s->indev);
 326 }
 327
 328 static void
 329 filter_redirector_set_indev(Object *obj, const char *value, Error **errp)
 330 {
 331     MirrorState *s = FILTER_REDIRECTOR(obj);
 332
 333     g_free(s->indev);
 334     s->indev = g_strdup(value);
 335 }
 336
 337 static char *filter_mirror_get_outdev(Object *obj, Error **errp)
 338 {
 339     MirrorState *s = FILTER_MIRROR(obj);
 340
 341     return g_strdup(s->outdev);
 342 }
 343
 344 static void
 345 filter_mirror_set_outdev(Object *obj, const char *value, Error **errp)
 346 {
 347     MirrorState *s = FILTER_MIRROR(obj);
 348
 349     g_free(s->outdev);
 350     s->outdev = g_strdup(value);
 351     if (!s->outdev) {
 352         error_setg(errp, "filter filter mirror needs 'outdev' "
 353                    "property set");
 354         return;
 355     }
 356 }
 357
 358 static char *filter_redirector_get_outdev(Object *obj, Error **errp)
 359 {
 360     MirrorState *s = FILTER_REDIRECTOR(obj);
 361
 362     return g_strdup(s->outdev);
 363 }
 364
 365 static void
 366 filter_redirector_set_outdev(Object *obj, const char *value, Error **errp)
 367 {
 368     MirrorState *s = FILTER_REDIRECTOR(obj);
 369
 370     g_free(s->outdev);
 371     s->outdev = g_strdup(value);
 372 }
 373
 374 static void filter_mirror_init(Object *obj)
 375 {
 376     object_property_add_str(obj, "outdev", filter_mirror_get_outdev,
 377                             filter_mirror_set_outdev, NULL);
 378 }
 379
 380 static void filter_redirector_init(Object *obj)
 381 {
 382     object_property_add_str(obj, "indev", filter_redirector_get_indev,
 383                             filter_redirector_set_indev, NULL);
 384     object_property_add_str(obj, "outdev", filter_redirector_get_outdev,
 385                             filter_redirector_set_outdev, NULL);
 386 }
 387
 388 static void filter_mirror_fini(Object *obj)
 389 {
 390     MirrorState *s = FILTER_MIRROR(obj);
 391
 392     g_free(s->outdev);
 393 }
 394
 395 static void filter_redirector_fini(Object *obj)
 396 {
 397     MirrorState *s = FILTER_REDIRECTOR(obj);
 398
 399     g_free(s->indev);
 400     g_free(s->outdev);
 401 }
 402
 403 static const TypeInfo filter_redirector_info = {
 404     .name = TYPE_FILTER_REDIRECTOR,
 405     .parent = TYPE_NETFILTER,
 406     .class_init = filter_redirector_class_init,
 407     .instance_init = filter_redirector_init,
 408     .instance_finalize = filter_redirector_fini,
 409     .instance_size = sizeof(MirrorState),
 410 };
 411
 412 static const TypeInfo filter_mirror_info = {
 413     .name = TYPE_FILTER_MIRROR,
 414     .parent = TYPE_NETFILTER,
 415     .class_init = filter_mirror_class_init,
 416     .instance_init = filter_mirror_init,
 417     .instance_finalize = filter_mirror_fini,
 418     .instance_size = sizeof(MirrorState),
 419 };
 420
 421 static void register_types(void)
 422 {
 423     type_register_static(&filter_mirror_info);
 424     type_register_static(&filter_redirector_info);
 425 }
 426
 427 type_init(register_types);