aboutsummaryrefslogtreecommitdiffstats
path: root/src/vnet/fib/fib_path_ext.c
blob: f5611f922714da2d2f1ce16c54bd404c9328caa7 (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
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
/*
 * 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 <vnet/mpls/mpls.h>
#include <vnet/dpo/mpls_label_dpo.h>
#include <vnet/dpo/load_balance.h>
#include <vnet/dpo/drop_dpo.h>

#include <vnet/fib/fib_path_ext.h>
#include <vnet/fib/fib_entry_src.h>
#include <vnet/fib/fib_path.h>
#include <vnet/fib/fib_path_list.h>
#include <vnet/fib/fib_internal.h>

const char *fib_path_ext_adj_flags_names[] = FIB_PATH_EXT_ADJ_ATTR_NAMES;
const char *fib_path_ext_mpls_flags_names[] = FIB_PATH_EXT_MPLS_ATTR_NAMES;

u8 *
format_fib_path_ext (u8 * s, va_list * args)
{
    fib_path_ext_t *path_ext;
    u32 ii;

    path_ext = va_arg (*args, fib_path_ext_t *);

    s = format(s, "path:%d ", path_ext->fpe_path_index);

    switch (path_ext->fpe_type)
    {
    case FIB_PATH_EXT_MPLS: {
        fib_path_ext_mpls_attr_t attr;

        if (path_ext->fpe_mpls_flags)
        {
            s = format(s, "mpls-flags:[");

            FOR_EACH_PATH_EXT_MPLS_ATTR(attr)
            {
                if ((1<<attr) & path_ext->fpe_mpls_flags) {
                    s = format(s, "%s", fib_path_ext_mpls_flags_names[attr]);
                }
            }
            s = format(s, "]");
        }
        s = format(s, " labels:[");
        for (ii = 0; ii < vec_len(path_ext->fpe_path.frp_label_stack); ii++)
        {
            s = format(s, "[%U]",
                       format_fib_mpls_label,
                       &path_ext->fpe_path.frp_label_stack[ii]);
        }
        s = format(s, "]");
        break;
    }
    case FIB_PATH_EXT_ADJ: {
        fib_path_ext_adj_attr_t attr;

        if (path_ext->fpe_adj_flags)
        {
            s = format(s, "adj-flags:[");
            FOR_EACH_PATH_EXT_ADJ_ATTR(attr)
            {
                if ((1<<attr) & path_ext->fpe_adj_flags)
                {
                    s = format(s, "%s", fib_path_ext_adj_flags_names[attr]);
                }
            }
            s = format(s, "]");
        }
        break;
    }
    }
    return (s);
}

int
fib_path_ext_cmp (fib_path_ext_t *path_ext,
		  const fib_route_path_t *rpath)
{
    return (fib_route_path_cmp(&path_ext->fpe_path, rpath));
}

static fib_path_list_walk_rc_t
fib_path_ext_match (fib_node_index_t pl_index,
		    fib_node_index_t path_index,
		    void *ctx)
{
    fib_path_ext_t *path_ext = ctx;

    if (!fib_path_cmp_w_route_path(path_index,
				   &path_ext->fpe_path))
    {
	path_ext->fpe_path_index = path_index;
	return (FIB_PATH_LIST_WALK_STOP);
    }
    return (FIB_PATH_LIST_WALK_CONTINUE);
}

void
fib_path_ext_resolve (fib_path_ext_t *path_ext,
		      fib_node_index_t path_list_index)
{
    /*
     * Find the path on the path list that this is an extension for
     */
    path_ext->fpe_path_index = FIB_NODE_INDEX_INVALID;
    fib_path_list_walk(path_list_index,
		       fib_path_ext_match,
		       path_ext);
}

static void
fib_path_ext_init (fib_path_ext_t *path_ext,
		   fib_node_index_t path_list_index,
                   fib_path_ext_type_t ext_type,
		   const fib_route_path_t *rpath)
{
    path_ext->fpe_path = *rpath;
    path_ext->fpe_path_index = FIB_NODE_INDEX_INVALID;
    path_ext->fpe_adj_flags = FIB_PATH_EXT_ADJ_FLAG_NONE;
    path_ext->fpe_type = ext_type;

    fib_path_ext_resolve(path_ext, path_list_index);
}

/**
 * @brief Return true if the label stack is implicit null
 * imp-null and pop equate to the same this as this level -
 * the label is coming off.
 */
static int
fib_path_ext_is_imp_null (fib_path_ext_t *path_ext)
{
    return ((1 == vec_len(path_ext->fpe_label_stack)) &&
	    ((MPLS_IETF_IMPLICIT_NULL_LABEL == path_ext->fpe_label_stack[0].fml_value) ||
             (MPLS_LABEL_POP == path_ext->fpe_label_stack[0].fml_value)));
}

mpls_label_dpo_flags_t
fib_path_ext_mpls_flags_to_mpls_label (fib_path_ext_mpls_flags_t fpe_flags)
{
    mpls_label_dpo_flags_t ml_flags = MPLS_LABEL_DPO_FLAG_NONE;

    if (fpe_flags &FIB_PATH_EXT_MPLS_FLAG_NO_IP_TTL_DECR)
    {
        ml_flags |= MPLS_LABEL_DPO_FLAG_NO_IP_TTL_DECR;
    }

    return (ml_flags);
}

load_balance_path_t *
fib_path_ext_stack (fib_path_ext_t *path_ext,
                    dpo_proto_t payload_proto,
                    fib_forward_chain_type_t child_fct,
		    load_balance_path_t *nhs)
{
    fib_forward_chain_type_t parent_fct;
    load_balance_path_t *nh;

    if (!fib_path_is_resolved(path_ext->fpe_path_index))
	return (nhs);

    /*
     * Since we are stacking this path-extension, it must have a valid out
     * label. From the chain type request by the child, determine what
     * chain type we will request from the parent.
     */
    switch (child_fct)
    {
    case FIB_FORW_CHAIN_TYPE_MPLS_EOS:
    {
	/*
	 * The EOS chain is a tricky since, when the path has an imp NULL one cannot know
         * the adjacency to link to without knowing what the packets payload protocol
	 * will be once the label is popped.
	 */
	if (fib_path_ext_is_imp_null(path_ext))
	{
            parent_fct = fib_forw_chain_type_from_dpo_proto(payload_proto);
        }
        else
        {
            /*
             * we have a label to stack. packets will thus be labelled when
             * they encounter the child, ergo, non-eos.
             */
	    parent_fct = FIB_FORW_CHAIN_TYPE_MPLS_NON_EOS;
        }
	break;
    }
    case FIB_FORW_CHAIN_TYPE_UNICAST_IP4:
    case FIB_FORW_CHAIN_TYPE_UNICAST_IP6:
	if (fib_path_ext_is_imp_null(path_ext))
	{
            /*
             * implicit-null label for the eos or IP chain, need to pick up
             * the IP adj
             */
	    parent_fct = child_fct;
	}
        else
        {
            /*
             * we have a label to stack. packets will thus be labelled when
             * they encounter the child, ergo, non-eos.
             */
	    parent_fct = FIB_FORW_CHAIN_TYPE_MPLS_NON_EOS;
        }
	break;
    case FIB_FORW_CHAIN_TYPE_MPLS_NON_EOS:
        parent_fct = child_fct;
	break;
    case FIB_FORW_CHAIN_TYPE_ETHERNET:
        parent_fct = FIB_FORW_CHAIN_TYPE_MPLS_NON_EOS;
	break;
    default:
        return (nhs);
	break;
    }

    dpo_id_t via_dpo = DPO_INVALID;

    /*
     * The next object in the graph after the imposition of the label
     * will be the DPO contributed by the path through which the packets
     * are to be sent. We stack the MPLS Label DPO on this path DPO
     */
    fib_path_contribute_forwarding(path_ext->fpe_path_index,
				   parent_fct,
                                   payload_proto,
				   &via_dpo);

    if (dpo_is_drop(&via_dpo) ||
	load_balance_is_drop(&via_dpo))
    {
	/*
	 * don't stack a path extension on a drop. doing so will create
	 * a LB bucket entry on drop, and we will lose a percentage of traffic.
	 */
    }
    else
    {
	vec_add2(nhs, nh, 1);
	nh->path_weight = fib_path_get_weight(path_ext->fpe_path_index);
	nh->path_index = path_ext->fpe_path_index;
	dpo_copy(&nh->path_dpo, &via_dpo);

	/*
	 * The label is stackable for this chain type
	 * construct the mpls header that will be imposed in the data-path
	 */
	if (!fib_path_ext_is_imp_null(path_ext))
	{
            /*
             * we use the parent protocol for the label so that
             * we pickup the correct MPLS imposition nodes to do
             * ip[46] processing.
             */
            dpo_id_t parent = DPO_INVALID;
            dpo_proto_t chain_proto;
            mpls_eos_bit_t eos;

            eos = (child_fct == FIB_FORW_CHAIN_TYPE_MPLS_NON_EOS ?
                   MPLS_NON_EOS :
                   MPLS_EOS);
            chain_proto = fib_forw_chain_type_to_dpo_proto(child_fct);

            dpo_copy(&parent, &nh->path_dpo);
            mpls_label_dpo_create(path_ext->fpe_label_stack,
                                  eos,
                                  chain_proto,
                                  fib_path_ext_mpls_flags_to_mpls_label(
                                      path_ext->fpe_mpls_flags),
                                  &parent,
                                  &nh->path_dpo);

	    dpo_reset(&parent);
	}
        else if (child_fct == FIB_FORW_CHAIN_TYPE_MPLS_EOS)
        {
            /*
             * MPLS EOS packets using an imp-null. Insert the disposition.
             */
            fib_path_stack_mpls_disp(nh->path_index,
                                     fib_forw_chain_type_to_dpo_proto(parent_fct),
                                     path_ext->fpe_label_stack[0].fml_mode,
                                     &nh->path_dpo);
        }
    }
    dpo_reset(&via_dpo);

    return (nhs);
}

fib_path_ext_t *
fib_path_ext_list_find (const fib_path_ext_list_t *list,
                        fib_path_ext_type_t ext_type,
                        const fib_route_path_t *rpath)
{
    fib_path_ext_t *path_ext;

    vec_foreach(path_ext, list->fpel_exts)
    {
        if ((path_ext->fpe_type == ext_type) &&
            !fib_path_ext_cmp(path_ext, rpath) )
        {
            return (path_ext);
        }
    }
    return (NULL);
}

fib_path_ext_t *
fib_path_ext_list_find_by_path_index (const fib_path_ext_list_t *list,
                                      fib_node_index_t path_index)
{
    fib_path_ext_t *path_ext;

    if (NULL != list)
    {
        vec_foreach(path_ext, list->fpel_exts)
        {
            if (path_ext->fpe_path_index == path_index)
            {
                return (path_ext);
            }
        }
    }
    return (NULL);
}


fib_path_ext_t *
fib_path_ext_list_push_back (fib_path_ext_list_t *list,
                             fib_node_index_t path_list_index,
                             fib_path_ext_type_t ext_type,
                             const fib_route_path_t *rpath)
{
    fib_path_ext_t *path_ext;

    path_ext = fib_path_ext_list_find(list, ext_type, rpath);

    if (NULL == path_ext)
    {
        vec_add2(list->fpel_exts, path_ext, 1);
        fib_path_ext_init(path_ext, path_list_index, ext_type, rpath);
    }

    return (path_ext);
}

/*
 * insert, sorted, a path extension to the entry's list.
 * It's not strictly necessary to sort the path extensions, since each
 * extension has the path index to which it resolves. However, by being
 * sorted the load-balance produced has a deterministic order, not an order
 * based on the sequence of extension additions. this is a considerable benefit.
 */
fib_path_ext_t *
fib_path_ext_list_insert (fib_path_ext_list_t *list,
                          fib_node_index_t path_list_index,
                          fib_path_ext_type_t ext_type,
                          const fib_route_path_t *rpath)
{
    fib_path_ext_t new_path_ext, *path_ext;
    int i = 0;

    if (0 == fib_path_ext_list_length(list))
    {
        return (fib_path_ext_list_push_back(list, path_list_index,
                                            ext_type, rpath));
    }

    fib_path_ext_init(&new_path_ext, path_list_index, ext_type, rpath);

    vec_foreach(path_ext, list->fpel_exts)
    {
        int res = fib_path_ext_cmp(path_ext, rpath);

        if (0 == res)
        {
            /*
             * don't add duplicate extensions. modify instead
             */
            vec_free(path_ext->fpe_label_stack);
            *path_ext = new_path_ext;
            goto done;
        }
        else if (res < 0)
        {
            i++;
        }
        else
        {
            break;
        }
    }
    vec_insert_elts(list->fpel_exts, &new_path_ext, 1, i);
done:
    return (&(list->fpel_exts[i]));
}

void
fib_path_ext_list_resolve (fib_path_ext_list_t *list,
                           fib_node_index_t path_list_index)
{
    fib_path_ext_t *path_ext;

    vec_foreach(path_ext, list->fpel_exts)
    {
        fib_path_ext_resolve(path_ext, path_list_index);
    };
}

void
fib_path_ext_list_remove (fib_path_ext_list_t *list,
                          fib_path_ext_type_t ext_type,
                          const fib_route_path_t *rpath)
{
    fib_path_ext_t *path_ext;

    path_ext = fib_path_ext_list_find(list, ext_type, rpath);

    if (NULL != path_ext)
    {
        /*
         * delete the element moving the remaining elements down 1 position.
         * this preserves the sorted order.
         */
        vec_free(path_ext->fpe_label_stack);
        vec_delete(list->fpel_exts, 1, (path_ext - list->fpel_exts));
    }
}

void
fib_path_ext_list_flush (fib_path_ext_list_t *list)
{
    fib_path_ext_t *path_ext;

    vec_foreach(path_ext, list->fpel_exts)
    {
        vec_free(path_ext->fpe_label_stack);
    };
    vec_free(list->fpel_exts);
    list->fpel_exts = NULL;
}

u8*
format_fib_path_ext_list (u8 * s, va_list * args)
{
    fib_path_ext_list_t *list;
    fib_path_ext_t *path_ext;

    list = va_arg (*args, fib_path_ext_list_t *);

    if (fib_path_ext_list_length(list))
    {
        s = format(s, "    Extensions:");
        vec_foreach(path_ext, list->fpel_exts)
        {
            s = format(s, "\n     %U", format_fib_path_ext, path_ext);
        };
    }

    return (s);
}

int
fib_path_ext_list_length (const fib_path_ext_list_t *list)
{
    return (vec_len(list->fpel_exts));
}