summaryrefslogtreecommitdiffstats
path: root/src/vnet/fib/fib_entry_src_adj.c
blob: 57a802d16c5d881ae63b77d075d7e0fcb14f66f1 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
/*
 * Copyright (c) 2016 Cisco and/or its affiliates.
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at:
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#include "fib_entry.h"
#include "fib_entry_src.h"
#include "fib_path_list.h"
#include "fib_table.h"
#include "fib_entry_cover.h"
#include "fib_attached_export.h"
#include "fib_path_ext.h"

/**
 * Source initialisation Function
 */
static void
fib_entry_src_adj_init (fib_entry_src_t *src)
{
    src->u.adj.fesa_cover = FIB_NODE_INDEX_INVALID;
    src->u.adj.fesa_sibling = FIB_NODE_INDEX_INVALID;
}

static void
fib_entry_src_adj_path_add (fib_entry_src_t *src,
                            const fib_entry_t *entry,
                            fib_path_list_flags_t pl_flags,
                            const fib_route_path_t *paths)
{
    const fib_route_path_t *rpath;

    if (FIB_NODE_INDEX_INVALID == src->fes_pl)
    {
        src->fes_pl = fib_path_list_create(pl_flags, paths);
    }
    else
    {
        src->fes_pl = fib_path_list_copy_and_path_add(src->fes_pl,
                                                      pl_flags,
                                                      paths);
    }

    /*
     * resolve the existing extensions
     */
    fib_path_ext_list_resolve(&src->fes_path_exts, src->fes_pl);

    /*
     * and new extensions
     */
    vec_foreach(rpath, paths)
    {
        fib_path_ext_list_insert(&src->fes_path_exts,
                                 src->fes_pl,
                                 FIB_PATH_EXT_ADJ,
                                 rpath);
    }
}

static void
fib_entry_src_adj_path_remove (fib_entry_src_t *src,
                               fib_path_list_flags_t pl_flags,
                               const fib_route_path_t *rpaths)
{
    const fib_route_path_t *rpath;

    if (FIB_NODE_INDEX_INVALID != src->fes_pl)
    {
        src->fes_pl = fib_path_list_copy_and_path_remove(src->fes_pl,
                                                         pl_flags,
                                                         rpaths);
    }

    /*
     * remove the path-extension for the path
     */
    vec_foreach(rpath, rpaths)
    {
        fib_path_ext_list_remove(&src->fes_path_exts, FIB_PATH_EXT_ADJ, rpath);
    };
    /*
     * resolve the remaining extensions
     */
    fib_path_ext_list_resolve(&src->fes_path_exts, src->fes_pl);
}

static void
fib_entry_src_adj_path_swap (fib_entry_src_t *src,
                             const fib_entry_t *entry,
                             fib_path_list_flags_t pl_flags,
                             const fib_route_path_t *paths)
{
    const fib_route_path_t *rpath;

    /*
     * flush all the old extensions before we create a brand new path-list
     */
    fib_path_ext_list_flush(&src->fes_path_exts);

    src->fes_pl = fib_path_list_create(pl_flags, paths);

    /*
     * and new extensions
     */
    vec_foreach(rpath, paths)
    {
        fib_path_ext_list_push_back(&src->fes_path_exts,
                                    src->fes_pl,
                                    FIB_PATH_EXT_ADJ,
                                    rpath);
    }
}

static void
fib_entry_src_adj_remove (fib_entry_src_t *src)
{
    src->fes_pl = FIB_NODE_INDEX_INVALID;
}

/*
 * Add a path-extension indicating whether this path is resolved,
 * because it passed the refinement check
 */
static void
fib_enty_src_adj_update_path_ext (fib_entry_src_t *src,
                                  fib_node_index_t path_index,
                                  fib_path_ext_adj_flags_t flags)
{
    fib_path_ext_t *path_ext;

    path_ext = fib_path_ext_list_find_by_path_index(&src->fes_path_exts,
                                                    path_index);

    if (NULL != path_ext)
    {
        path_ext->fpe_adj_flags = flags;
    }
    else
    {
        ASSERT(!"no path extension");
    }
}

typedef struct fib_entry_src_path_list_walk_cxt_t_
{
    fib_entry_src_t *src;
    u32 cover_itf;
    fib_path_ext_adj_flags_t flags;
} fib_entry_src_path_list_walk_cxt_t;

static fib_path_list_walk_rc_t
fib_entry_src_adj_path_list_walk (fib_node_index_t pl_index,
                                  fib_node_index_t path_index,
                                  void *arg)
{
    fib_entry_src_path_list_walk_cxt_t *ctx;
    u32 adj_itf;

    ctx = arg;
    adj_itf = fib_path_get_resolving_interface(path_index);

    if (ctx->cover_itf == adj_itf)
    {
        fib_enty_src_adj_update_path_ext(ctx->src, path_index,
                                         FIB_PATH_EXT_ADJ_FLAG_REFINES_COVER);
        ctx->flags |= FIB_PATH_EXT_ADJ_FLAG_REFINES_COVER;
    }
    else
    {
        /*
         * if the interface the adj is on is unnumbered to the
         * cover's, then allow that too.
         */
        vnet_sw_interface_t *swif;

        swif = vnet_get_sw_interface (vnet_get_main(), adj_itf);

        if (swif->flags & VNET_SW_INTERFACE_FLAG_UNNUMBERED &&
            ctx->cover_itf == swif->unnumbered_sw_if_index)
        {
            fib_enty_src_adj_update_path_ext(ctx->src, path_index,
                                             FIB_PATH_EXT_ADJ_FLAG_REFINES_COVER);
            ctx->flags |= FIB_PATH_EXT_ADJ_FLAG_REFINES_COVER;
        }
        else
        {
            fib_enty_src_adj_update_path_ext(ctx->src, path_index,
                                             FIB_PATH_EXT_ADJ_FLAG_NONE);
        }
    }
    return (FIB_PATH_LIST_WALK_CONTINUE);
}

static int
fib_entry_src_adj_activate (fib_entry_src_t *src,
                            const fib_entry_t *fib_entry)
{
    fib_entry_t *cover;

    /*
     * find the covering prefix. become a dependent thereof.
     * there should always be a cover, though it may be the default route.
     */
    src->u.adj.fesa_cover = fib_table_get_less_specific(fib_entry->fe_fib_index,
                                                        &fib_entry->fe_prefix);

    ASSERT(FIB_NODE_INDEX_INVALID != src->u.adj.fesa_cover);
    ASSERT(fib_entry_get_index(fib_entry) != src->u.adj.fesa_cover);

    cover = fib_entry_get(src->u.adj.fesa_cover);

    ASSERT(cover != fib_entry);

    src->u.adj.fesa_sibling =
        fib_entry_cover_track(cover,
                              fib_entry_get_index(fib_entry));

    /*
     * if the cover is attached on the same interface as this adj source then
     * install the FIB entry via the adj. otherwise install a drop.
     * This prevents ARP/ND entries that on interface X that do not belong
     * on X's subnet from being added to the FIB. To do so would allow
     * nefarious gratuitous ARP requests from attracting traffic to the sender.
     *
     * and yes, I really do mean attached and not connected.
     * this abomination;
     *   ip route add 10.0.0.0/24 Eth0
     * is attached. and we want adj-fibs to install on Eth0.
     */
    if (FIB_ENTRY_FLAG_ATTACHED & fib_entry_get_flags_i(cover))
    {
        fib_entry_src_path_list_walk_cxt_t ctx = {
            .cover_itf = fib_entry_get_resolving_interface(src->u.adj.fesa_cover),
            .flags = FIB_PATH_EXT_ADJ_FLAG_NONE,
            .src = src,
        };

        fib_path_list_walk(src->fes_pl,
                           fib_entry_src_adj_path_list_walk,
                           &ctx);

        /*
         * active the entry is one of the paths refines the cover.
         */
        return (FIB_PATH_EXT_ADJ_FLAG_REFINES_COVER & ctx.flags);
    }
    return (0);
}

/*
 * Source re-activate.
 * Called when the source path lit has changed and the source is still
 * the best source
 */
static int
fib_entry_src_adj_reactivate (fib_entry_src_t *src,
                              const fib_entry_t *fib_entry)
{
    fib_entry_src_path_list_walk_cxt_t ctx = {
        .cover_itf = fib_entry_get_resolving_interface(src->u.adj.fesa_cover),
        .flags = FIB_PATH_EXT_ADJ_FLAG_NONE,
        .src = src,
    };

    fib_path_list_walk(src->fes_pl,
                       fib_entry_src_adj_path_list_walk,
                       &ctx);

    return (FIB_PATH_EXT_ADJ_FLAG_REFINES_COVER & ctx.flags);
}

/*
 * Source Deactivate.
 * Called when the source is no longer best source on the entry
 */
static void
fib_entry_src_adj_deactivate (fib_entry_src_t *src,
                              const fib_entry_t *fib_entry)
{
    fib_entry_t *cover;

    /*
     * remove the depednecy on the covering entry
     */
    cover = fib_entry_get(src->u.adj.fesa_cover);

    fib_entry_cover_untrack(cover, src->u.adj.fesa_sibling);

    /*
     * tell the cover this entry no longer needs exporting
     */
    fib_attached_export_covered_removed(cover, fib_entry_get_index(fib_entry));

    src->u.adj.fesa_cover = FIB_NODE_INDEX_INVALID;
}

static u8*
fib_entry_src_adj_format (fib_entry_src_t *src,
                         u8* s)
{
    return (format(s, " cover:%d", src->u.adj.fesa_cover));
}

static void
fib_entry_src_adj_installed (fib_entry_src_t *src,
                             const fib_entry_t *fib_entry)
{
    /*
     * The adj source now rules! poke our cover to get exported
     */
    fib_entry_t *cover;

    ASSERT(FIB_NODE_INDEX_INVALID != src->u.adj.fesa_cover);
    cover = fib_entry_get(src->u.adj.fesa_cover);

    fib_attached_export_covered_added(cover,
                                      fib_entry_get_index(fib_entry));
}

static fib_entry_src_cover_res_t
fib_entry_src_adj_cover_change (fib_entry_src_t *src,
                                const fib_entry_t *fib_entry)
{
    fib_entry_src_cover_res_t res = {
        .install = !0,
        .bw_reason = FIB_NODE_BW_REASON_FLAG_NONE,
    };

    fib_entry_src_adj_deactivate(src, fib_entry);

    res.install = fib_entry_src_adj_activate(src, fib_entry);

    if (res.install) {
        /*
         * ADJ fib can install
         */
        res.bw_reason = FIB_NODE_BW_REASON_FLAG_EVALUATE;
    }

    FIB_ENTRY_DBG(fib_entry, "adj-src-cover-changed");
    return (res);
}

/*
 * fib_entry_src_adj_cover_update
 */
static fib_entry_src_cover_res_t
fib_entry_src_adj_cover_update (fib_entry_src_t *src,
                                const fib_entry_t *fib_entry)
{
    /*
     * the cover has updated, i.e. its forwarding or flags
     * have changed. don't decativate/activate here, since this
     * prefix is updated during the covers walk.
     */
    fib_entry_src_cover_res_t res = {
        .install = !0,
        .bw_reason = FIB_NODE_BW_REASON_FLAG_NONE,
    };
    fib_entry_t *cover;

    ASSERT(FIB_NODE_INDEX_INVALID != src->u.adj.fesa_cover);

    cover = fib_entry_get(src->u.adj.fesa_cover);

    res.install = (FIB_ENTRY_FLAG_ATTACHED & fib_entry_get_flags_i(cover));

    FIB_ENTRY_DBG(fib_entry, "adj-src-cover-updated");

    return (res);
}

const static fib_entry_src_vft_t adj_src_vft = {
    .fesv_init = fib_entry_src_adj_init,
    .fesv_path_swap = fib_entry_src_adj_path_swap,
    .fesv_path_add = fib_entry_src_adj_path_add,
    .fesv_path_remove = fib_entry_src_adj_path_remove,
    .fesv_remove = fib_entry_src_adj_remove,
    .fesv_activate = fib_entry_src_adj_activate,
    .fesv_deactivate = fib_entry_src_adj_deactivate,
    .fesv_reactivate = fib_entry_src_adj_reactivate,
    .fesv_format = fib_entry_src_adj_format,
    .fesv_installed = fib_entry_src_adj_installed,
    .fesv_cover_change = fib_entry_src_adj_cover_change,
    .fesv_cover_update = fib_entry_src_adj_cover_update,
};

void
fib_entry_src_adj_register (void)
{
    fib_entry_src_register(FIB_SOURCE_ADJ, &adj_src_vft);
}