Line data Source code
1 : // SPDX-License-Identifier: GPL-2.0-or-later
2 : /*
3 : * MPLS definitions
4 : * Copyright 2015 Cumulus Networks, Inc.
5 : */
6 :
7 : #ifndef _QUAGGA_MPLS_H
8 : #define _QUAGGA_MPLS_H
9 :
10 : #include <zebra.h>
11 : #include <vxlan.h>
12 : #include <arpa/inet.h>
13 :
14 : #ifdef __cplusplus
15 : extern "C" {
16 : #endif
17 :
18 : #ifdef MPLS_LABEL_MAX
19 : #undef MPLS_LABEL_MAX
20 : #endif
21 :
22 : #define MPLS_LABEL_HELPSTR \
23 : "Specify label(s) for this route\nOne or more " \
24 : "labels in the range (16-1048575) separated by '/'\n"
25 :
26 : /* Well-known MPLS label values (RFC 3032 etc). */
27 : #define MPLS_LABEL_IPV4_EXPLICIT_NULL 0 /* [RFC3032] */
28 : #define MPLS_LABEL_ROUTER_ALERT 1 /* [RFC3032] */
29 : #define MPLS_LABEL_IPV6_EXPLICIT_NULL 2 /* [RFC3032] */
30 : #define MPLS_LABEL_IMPLICIT_NULL 3 /* [RFC3032] */
31 : #define MPLS_LABEL_ELI 7 /* [RFC6790] */
32 : #define MPLS_LABEL_GAL 13 /* [RFC5586] */
33 : #define MPLS_LABEL_OAM_ALERT 14 /* [RFC3429] */
34 : #define MPLS_LABEL_EXTENSION 15 /* [RFC7274] */
35 : #define MPLS_LABEL_MAX 1048575
36 : #define MPLS_LABEL_VALUE_MASK 0x000FFFFF
37 : #define MPLS_LABEL_NONE 0xFFFFFFFF /* for internal use only */
38 :
39 : /* Minimum and maximum label values */
40 : #define MPLS_LABEL_RESERVED_MIN 0
41 : #define MPLS_LABEL_RESERVED_MAX 15
42 : #define MPLS_LABEL_UNRESERVED_MIN 16
43 : #define MPLS_LABEL_UNRESERVED_MAX 1048575
44 : #define MPLS_LABEL_BASE_ANY 0
45 :
46 : /* Default min and max SRGB label range */
47 : /* Even if the SRGB allows to manage different Label space between routers,
48 : * if an operator want to use the same SRGB for all its router, we must fix
49 : * a common range. However, Cisco start its SRGB at 16000 and Juniper ends
50 : * its SRGB at 16384 for OSPF. Thus, by fixing the minimum SRGB label to
51 : * 8000 we could deal with both Cisco and Juniper.
52 : */
53 : #define MPLS_DEFAULT_MIN_SRGB_LABEL 8000
54 : #define MPLS_DEFAULT_MAX_SRGB_LABEL 50000
55 : #define MPLS_DEFAULT_MIN_SRGB_SIZE 5000
56 : #define MPLS_DEFAULT_MAX_SRGB_SIZE 20000
57 :
58 : /* Maximum # labels that can be pushed. */
59 : #define MPLS_MAX_LABELS 16
60 :
61 : #define IS_MPLS_RESERVED_LABEL(label) (label <= MPLS_LABEL_RESERVED_MAX)
62 :
63 : #define IS_MPLS_UNRESERVED_LABEL(label) \
64 : (label >= MPLS_LABEL_UNRESERVED_MIN \
65 : && label <= MPLS_LABEL_UNRESERVED_MAX)
66 :
67 : /* Definitions for a MPLS label stack entry (RFC 3032). This encodes the
68 : * label, EXP, BOS and TTL fields.
69 : */
70 : typedef unsigned int mpls_lse_t;
71 :
72 : #define MPLS_LS_LABEL_MASK 0xFFFFF000
73 : #define MPLS_LS_LABEL_SHIFT 12
74 : #define MPLS_LS_EXP_MASK 0x00000E00
75 : #define MPLS_LS_EXP_SHIFT 9
76 : #define MPLS_LS_S_MASK 0x00000100
77 : #define MPLS_LS_S_SHIFT 8
78 : #define MPLS_LS_TTL_MASK 0x000000FF
79 : #define MPLS_LS_TTL_SHIFT 0
80 :
81 : #define MPLS_LABEL_VALUE(lse) \
82 : ((lse & MPLS_LS_LABEL_MASK) >> MPLS_LS_LABEL_SHIFT)
83 : #define MPLS_LABEL_EXP(lse) ((lse & MPLS_LS_EXP_MASK) >> MPLS_LS_EXP_SHIFT)
84 : #define MPLS_LABEL_BOS(lse) ((lse & MPLS_LS_S_MASK) >> MPLS_LS_S_SHIFT)
85 : #define MPLS_LABEL_TTL(lse) ((lse & MPLS_LS_TTL_MASK) >> MPLS_LS_TTL_SHIFT)
86 :
87 : #define IS_MPLS_LABEL_BOS(ls) (MPLS_LABEL_BOS(ls) == 1)
88 :
89 : #define MPLS_LABEL_LEN_BITS 20
90 :
91 : /* MPLS label value as a 32-bit (mostly we only care about the label value). */
92 : typedef unsigned int mpls_label_t;
93 :
94 : struct mpls_label_stack {
95 : uint8_t num_labels;
96 : uint8_t reserved[3];
97 : mpls_label_t label[0]; /* 1 or more labels */
98 : };
99 :
100 : /* The MPLS explicit-null label is 0 which means when you memset a mpls_label_t
101 : * to zero you have set that variable to explicit-null which was probably not
102 : * your intent. The work-around is to use one bit to indicate if the
103 : * mpls_label_t has been set by the user. MPLS_INVALID_LABEL has this bit clear
104 : * so that we can use MPLS_INVALID_LABEL to initialize mpls_label_t variables.
105 : */
106 : #define MPLS_INVALID_LABEL 0xFFFDFFFF
107 :
108 : /* LSP types. */
109 : enum lsp_types_t {
110 : ZEBRA_LSP_NONE = 0, /* No LSP. */
111 : ZEBRA_LSP_STATIC = 1, /* Static LSP. */
112 : ZEBRA_LSP_LDP = 2, /* LDP LSP. */
113 : ZEBRA_LSP_BGP = 3, /* BGP LSP. */
114 : ZEBRA_LSP_OSPF_SR = 4,/* OSPF Segment Routing LSP. */
115 : ZEBRA_LSP_ISIS_SR = 5,/* IS-IS Segment Routing LSP. */
116 : ZEBRA_LSP_SHARP = 6, /* Identifier for test protocol */
117 : ZEBRA_LSP_SRTE = 7, /* SR-TE LSP */
118 : ZEBRA_LSP_EVPN = 8, /* EVPN VNI Label */
119 : };
120 :
121 : /* Functions for basic label operations. */
122 :
123 0 : static inline void vni2label(vni_t vni, mpls_label_t *label)
124 : {
125 0 : uint8_t *tag = (uint8_t *)label;
126 :
127 0 : assert(tag);
128 :
129 0 : tag[0] = (vni >> 16) & 0xFF;
130 0 : tag[1] = (vni >> 8) & 0xFF;
131 0 : tag[2] = vni & 0xFF;
132 0 : }
133 :
134 0 : static inline vni_t label2vni(const mpls_label_t *label)
135 : {
136 0 : uint8_t *tag = (uint8_t *)label;
137 0 : vni_t vni;
138 :
139 0 : assert(tag);
140 :
141 0 : vni = ((uint32_t)*tag++ << 16);
142 0 : vni |= (uint32_t)*tag++ << 8;
143 0 : vni |= (uint32_t)(*tag & 0xFF);
144 :
145 0 : return vni;
146 : }
147 :
148 : /* Encode a label stack entry from fields; convert to network byte-order as
149 : * the Netlink interface expects MPLS labels to be in this format.
150 : */
151 0 : static inline mpls_lse_t mpls_lse_encode(mpls_label_t label, uint32_t ttl,
152 : uint32_t exp, uint32_t bos)
153 : {
154 0 : mpls_lse_t lse;
155 0 : lse = htonl((label << MPLS_LS_LABEL_SHIFT) | (exp << MPLS_LS_EXP_SHIFT)
156 : | (bos ? (1 << MPLS_LS_S_SHIFT) : 0)
157 : | (ttl << MPLS_LS_TTL_SHIFT));
158 0 : return lse;
159 : }
160 :
161 : /* Extract the fields from a label stack entry after converting to host-byte
162 : * order. This is expected to be called only for messages received over the
163 : * Netlink interface.
164 : */
165 0 : static inline void mpls_lse_decode(mpls_lse_t lse, mpls_label_t *label,
166 : uint32_t *ttl, uint32_t *exp, uint32_t *bos)
167 : {
168 0 : mpls_lse_t local_lse;
169 :
170 0 : local_lse = ntohl(lse);
171 0 : *label = MPLS_LABEL_VALUE(local_lse);
172 0 : *exp = MPLS_LABEL_EXP(local_lse);
173 0 : *bos = MPLS_LABEL_BOS(local_lse);
174 0 : *ttl = MPLS_LABEL_TTL(local_lse);
175 0 : }
176 :
177 : /* Invalid label index value (when used with BGP Prefix-SID). Should
178 : * match the BGP definition.
179 : */
180 : #define MPLS_INVALID_LABEL_INDEX 0xFFFFFFFF
181 :
182 : /* Printable string for labels (with consideration for reserved values). */
183 0 : static inline char *label2str(mpls_label_t label, enum lsp_types_t type,
184 : char *buf, size_t len)
185 : {
186 0 : if (type == ZEBRA_LSP_EVPN) {
187 0 : snprintf(buf, len, "%u", label2vni(&label));
188 0 : return (buf);
189 : }
190 :
191 0 : switch (label) {
192 0 : case MPLS_LABEL_IPV4_EXPLICIT_NULL:
193 0 : strlcpy(buf, "IPv4 Explicit Null", len);
194 0 : return (buf);
195 0 : case MPLS_LABEL_ROUTER_ALERT:
196 0 : strlcpy(buf, "Router Alert", len);
197 0 : return (buf);
198 0 : case MPLS_LABEL_IPV6_EXPLICIT_NULL:
199 0 : strlcpy(buf, "IPv6 Explicit Null", len);
200 0 : return (buf);
201 0 : case MPLS_LABEL_IMPLICIT_NULL:
202 0 : strlcpy(buf, "implicit-null", len);
203 0 : return (buf);
204 0 : case MPLS_LABEL_ELI:
205 0 : strlcpy(buf, "Entropy Label Indicator", len);
206 0 : return (buf);
207 0 : case MPLS_LABEL_GAL:
208 0 : strlcpy(buf, "Generic Associated Channel", len);
209 0 : return (buf);
210 0 : case MPLS_LABEL_OAM_ALERT:
211 0 : strlcpy(buf, "OAM Alert", len);
212 0 : return (buf);
213 0 : case MPLS_LABEL_EXTENSION:
214 0 : strlcpy(buf, "Extension", len);
215 0 : return (buf);
216 0 : default:
217 0 : if (label < 16)
218 0 : snprintf(buf, len, "Reserved (%u)", label);
219 : else
220 0 : snprintf(buf, len, "%u", label);
221 : return buf;
222 : }
223 : }
224 :
225 : /*
226 : * String to label conversion, labels separated by '/'.
227 : */
228 : int mpls_str2label(const char *label_str, uint8_t *num_labels,
229 : mpls_label_t *labels);
230 :
231 : /* Generic string buffer for label-stack-to-str */
232 : #define MPLS_LABEL_STRLEN 1024
233 :
234 : /*
235 : * Label to string conversion, labels in string separated by '/'.
236 : */
237 : char *mpls_label2str(uint8_t num_labels, const mpls_label_t *labels, char *buf,
238 : int len, enum lsp_types_t type, int pretty);
239 :
240 : #ifdef __cplusplus
241 : }
242 : #endif
243 :
244 : #endif
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