aboutsummaryrefslogtreecommitdiffstats
path: root/src/vnet/fib/fib_path_ext.c
blob: 08293bcf17565e0a114f48452753b4fa2db46004 (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
/*
 * 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>

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 labels:",
	       path_ext->fpe_path_index);
    for (ii = 0; ii < vec_len(path_ext->fpe_path.frp_label_stack); ii++)
    {
	s = format(s, "%U ",
		   format_mpls_unicast_label,
		   path_ext->fpe_path.frp_label_stack[ii]);
    }
    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 int
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 (0);
    }
    // keep going
    return (1);
}

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);
}

void
fib_path_ext_init (fib_path_ext_t *path_ext,
		   fib_node_index_t path_list_index,
		   const fib_route_path_t *rpath)
{
    path_ext->fpe_path = *rpath;
    path_ext->fpe_path_index = FIB_NODE_INDEX_INVALID;

    fib_path_ext_resolve(path_ext, path_list_index);
}

/**
 * @brief Return true if the label stack is implicit null
 */
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]));
}

load_balance_path_t *
fib_path_ext_stack (fib_path_ext_t *path_ext,
                    fib_forward_chain_type_t child_fct,
                    fib_forward_chain_type_t imp_null_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 = imp_null_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_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;
    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,
				   &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_proto_t chain_proto;
            mpls_eos_bit_t eos;
            index_t mldi;

            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);

            mldi = mpls_label_dpo_create(path_ext->fpe_label_stack,
                                         eos, 255, 0,
                                         chain_proto,
                                         &nh->path_dpo);

	    dpo_set(&nh->path_dpo,
		    DPO_MPLS_LABEL,
                    chain_proto,
                    mldi);
	}
    }
    dpo_reset(&via_dpo);

    return (nhs);
}