Line data Source code
1 : /*
2 : * MPLS definitions
3 : * Copyright 2015 Cumulus Networks, Inc.
4 : *
5 : * This file is part of GNU Zebra.
6 : *
7 : * GNU Zebra is free software; you can redistribute it and/or modify
8 : * it under the terms of the GNU General Public License as published
9 : * by the Free Software Foundation; either version 2, or (at your
10 : * option) any later version.
11 : *
12 : * GNU Zebra is distributed in the hope that it will be useful, but
13 : * WITHOUT ANY WARRANTY; without even the implied warranty of
14 : * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 : * General Public License for more details.
16 : *
17 : * You should have received a copy of the GNU General Public License along
18 : * with this program; see the file COPYING; if not, write to the Free Software
19 : * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
20 : */
21 :
22 : #ifndef _QUAGGA_MPLS_H
23 : #define _QUAGGA_MPLS_H
24 :
25 : #include <zebra.h>
26 : #include <arpa/inet.h>
27 :
28 : #ifdef __cplusplus
29 : extern "C" {
30 : #endif
31 :
32 : #ifdef MPLS_LABEL_MAX
33 : #undef MPLS_LABEL_MAX
34 : #endif
35 :
36 : #define MPLS_LABEL_HELPSTR \
37 : "Specify label(s) for this route\nOne or more " \
38 : "labels in the range (16-1048575) separated by '/'\n"
39 :
40 : /* Well-known MPLS label values (RFC 3032 etc). */
41 : #define MPLS_LABEL_IPV4_EXPLICIT_NULL 0 /* [RFC3032] */
42 : #define MPLS_LABEL_ROUTER_ALERT 1 /* [RFC3032] */
43 : #define MPLS_LABEL_IPV6_EXPLICIT_NULL 2 /* [RFC3032] */
44 : #define MPLS_LABEL_IMPLICIT_NULL 3 /* [RFC3032] */
45 : #define MPLS_LABEL_ELI 7 /* [RFC6790] */
46 : #define MPLS_LABEL_GAL 13 /* [RFC5586] */
47 : #define MPLS_LABEL_OAM_ALERT 14 /* [RFC3429] */
48 : #define MPLS_LABEL_EXTENSION 15 /* [RFC7274] */
49 : #define MPLS_LABEL_MAX 1048575
50 : #define MPLS_LABEL_VALUE_MASK 0x000FFFFF
51 : #define MPLS_LABEL_NONE 0xFFFFFFFF /* for internal use only */
52 :
53 : /* Minimum and maximum label values */
54 : #define MPLS_LABEL_RESERVED_MIN 0
55 : #define MPLS_LABEL_RESERVED_MAX 15
56 : #define MPLS_LABEL_UNRESERVED_MIN 16
57 : #define MPLS_LABEL_UNRESERVED_MAX 1048575
58 : #define MPLS_LABEL_BASE_ANY 0
59 :
60 : /* Default min and max SRGB label range */
61 : /* Even if the SRGB allows to manage different Label space between routers,
62 : * if an operator want to use the same SRGB for all its router, we must fix
63 : * a common range. However, Cisco start its SRGB at 16000 and Juniper ends
64 : * its SRGB at 16384 for OSPF. Thus, by fixing the minimum SRGB label to
65 : * 8000 we could deal with both Cisco and Juniper.
66 : */
67 : #define MPLS_DEFAULT_MIN_SRGB_LABEL 8000
68 : #define MPLS_DEFAULT_MAX_SRGB_LABEL 50000
69 : #define MPLS_DEFAULT_MIN_SRGB_SIZE 5000
70 : #define MPLS_DEFAULT_MAX_SRGB_SIZE 20000
71 :
72 : /* Maximum # labels that can be pushed. */
73 : #define MPLS_MAX_LABELS 16
74 :
75 : #define IS_MPLS_RESERVED_LABEL(label) (label <= MPLS_LABEL_RESERVED_MAX)
76 :
77 : #define IS_MPLS_UNRESERVED_LABEL(label) \
78 : (label >= MPLS_LABEL_UNRESERVED_MIN \
79 : && label <= MPLS_LABEL_UNRESERVED_MAX)
80 :
81 : /* Definitions for a MPLS label stack entry (RFC 3032). This encodes the
82 : * label, EXP, BOS and TTL fields.
83 : */
84 : typedef unsigned int mpls_lse_t;
85 :
86 : #define MPLS_LS_LABEL_MASK 0xFFFFF000
87 : #define MPLS_LS_LABEL_SHIFT 12
88 : #define MPLS_LS_EXP_MASK 0x00000E00
89 : #define MPLS_LS_EXP_SHIFT 9
90 : #define MPLS_LS_S_MASK 0x00000100
91 : #define MPLS_LS_S_SHIFT 8
92 : #define MPLS_LS_TTL_MASK 0x000000FF
93 : #define MPLS_LS_TTL_SHIFT 0
94 :
95 : #define MPLS_LABEL_VALUE(lse) \
96 : ((lse & MPLS_LS_LABEL_MASK) >> MPLS_LS_LABEL_SHIFT)
97 : #define MPLS_LABEL_EXP(lse) ((lse & MPLS_LS_EXP_MASK) >> MPLS_LS_EXP_SHIFT)
98 : #define MPLS_LABEL_BOS(lse) ((lse & MPLS_LS_S_MASK) >> MPLS_LS_S_SHIFT)
99 : #define MPLS_LABEL_TTL(lse) ((lse & MPLS_LS_TTL_MASK) >> MPLS_LS_TTL_SHIFT)
100 :
101 : #define IS_MPLS_LABEL_BOS(ls) (MPLS_LABEL_BOS(ls) == 1)
102 :
103 : #define MPLS_LABEL_LEN_BITS 20
104 :
105 : /* MPLS label value as a 32-bit (mostly we only care about the label value). */
106 : typedef unsigned int mpls_label_t;
107 :
108 : struct mpls_label_stack {
109 : uint8_t num_labels;
110 : uint8_t reserved[3];
111 : mpls_label_t label[0]; /* 1 or more labels */
112 : };
113 :
114 : /* The MPLS explicit-null label is 0 which means when you memset a mpls_label_t
115 : * to zero you have set that variable to explicit-null which was probably not
116 : * your intent. The work-around is to use one bit to indicate if the
117 : * mpls_label_t has been set by the user. MPLS_INVALID_LABEL has this bit clear
118 : * so that we can use MPLS_INVALID_LABEL to initialize mpls_label_t variables.
119 : */
120 : #define MPLS_INVALID_LABEL 0xFFFDFFFF
121 :
122 : /* LSP types. */
123 : enum lsp_types_t {
124 : ZEBRA_LSP_NONE = 0, /* No LSP. */
125 : ZEBRA_LSP_STATIC = 1, /* Static LSP. */
126 : ZEBRA_LSP_LDP = 2, /* LDP LSP. */
127 : ZEBRA_LSP_BGP = 3, /* BGP LSP. */
128 : ZEBRA_LSP_OSPF_SR = 4,/* OSPF Segment Routing LSP. */
129 : ZEBRA_LSP_ISIS_SR = 5,/* IS-IS Segment Routing LSP. */
130 : ZEBRA_LSP_SHARP = 6, /* Identifier for test protocol */
131 : ZEBRA_LSP_SRTE = 7, /* SR-TE LSP */
132 : };
133 :
134 : /* Functions for basic label operations. */
135 :
136 : /* Encode a label stack entry from fields; convert to network byte-order as
137 : * the Netlink interface expects MPLS labels to be in this format.
138 : */
139 0 : static inline mpls_lse_t mpls_lse_encode(mpls_label_t label, uint32_t ttl,
140 : uint32_t exp, uint32_t bos)
141 : {
142 0 : mpls_lse_t lse;
143 0 : lse = htonl((label << MPLS_LS_LABEL_SHIFT) | (exp << MPLS_LS_EXP_SHIFT)
144 : | (bos ? (1 << MPLS_LS_S_SHIFT) : 0)
145 : | (ttl << MPLS_LS_TTL_SHIFT));
146 0 : return lse;
147 : }
148 :
149 : /* Extract the fields from a label stack entry after converting to host-byte
150 : * order. This is expected to be called only for messages received over the
151 : * Netlink interface.
152 : */
153 1 : static inline void mpls_lse_decode(mpls_lse_t lse, mpls_label_t *label,
154 : uint32_t *ttl, uint32_t *exp, uint32_t *bos)
155 : {
156 1 : mpls_lse_t local_lse;
157 :
158 1 : local_lse = ntohl(lse);
159 1 : *label = MPLS_LABEL_VALUE(local_lse);
160 1 : *exp = MPLS_LABEL_EXP(local_lse);
161 1 : *bos = MPLS_LABEL_BOS(local_lse);
162 1 : *ttl = MPLS_LABEL_TTL(local_lse);
163 : }
164 :
165 : /* Invalid label index value (when used with BGP Prefix-SID). Should
166 : * match the BGP definition.
167 : */
168 : #define MPLS_INVALID_LABEL_INDEX 0xFFFFFFFF
169 :
170 : /* Printable string for labels (with consideration for reserved values). */
171 0 : static inline char *label2str(mpls_label_t label, char *buf, size_t len)
172 : {
173 0 : switch (label) {
174 0 : case MPLS_LABEL_IPV4_EXPLICIT_NULL:
175 0 : strlcpy(buf, "IPv4 Explicit Null", len);
176 0 : return (buf);
177 0 : case MPLS_LABEL_ROUTER_ALERT:
178 0 : strlcpy(buf, "Router Alert", len);
179 0 : return (buf);
180 0 : case MPLS_LABEL_IPV6_EXPLICIT_NULL:
181 0 : strlcpy(buf, "IPv6 Explicit Null", len);
182 0 : return (buf);
183 0 : case MPLS_LABEL_IMPLICIT_NULL:
184 0 : strlcpy(buf, "implicit-null", len);
185 0 : return (buf);
186 0 : case MPLS_LABEL_ELI:
187 0 : strlcpy(buf, "Entropy Label Indicator", len);
188 0 : return (buf);
189 0 : case MPLS_LABEL_GAL:
190 0 : strlcpy(buf, "Generic Associated Channel", len);
191 0 : return (buf);
192 0 : case MPLS_LABEL_OAM_ALERT:
193 0 : strlcpy(buf, "OAM Alert", len);
194 0 : return (buf);
195 0 : case MPLS_LABEL_EXTENSION:
196 0 : strlcpy(buf, "Extension", len);
197 0 : return (buf);
198 0 : default:
199 0 : if (label < 16)
200 0 : snprintf(buf, len, "Reserved (%u)", label);
201 : else
202 0 : snprintf(buf, len, "%u", label);
203 : return (buf);
204 : }
205 : }
206 :
207 : /*
208 : * String to label conversion, labels separated by '/'.
209 : */
210 : int mpls_str2label(const char *label_str, uint8_t *num_labels,
211 : mpls_label_t *labels);
212 :
213 : /* Generic string buffer for label-stack-to-str */
214 : #define MPLS_LABEL_STRLEN 1024
215 :
216 : /*
217 : * Label to string conversion, labels in string separated by '/'.
218 : */
219 : char *mpls_label2str(uint8_t num_labels, const mpls_label_t *labels, char *buf,
220 : int len, int pretty);
221 :
222 : #ifdef __cplusplus
223 : }
224 : #endif
225 :
226 : #endif
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