[mirror_frr.git] / lib / mpls.h

/*
 * MPLS definitions
 * Copyright 2015 Cumulus Networks, Inc.
 *
 * This file is part of GNU Zebra.
 *
 * GNU Zebra is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published
 * by the Free Software Foundation; either version 2, or (at your
 * option) any later version.
 *
 * GNU Zebra is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; see the file COPYING; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
 */

#ifndef _QUAGGA_MPLS_H
#define _QUAGGA_MPLS_H

#include <arpa/inet.h>

/* Well-known MPLS label values (RFC 3032 etc). */
#define MPLS_V4_EXP_NULL_LABEL             0
#define MPLS_RA_LABEL                      1
#define MPLS_V6_EXP_NULL_LABEL             2
#define MPLS_IMP_NULL_LABEL                3
#define MPLS_ENTROPY_LABEL_INDICATOR       7
#define MPLS_GAL_LABEL                     13
#define MPLS_OAM_ALERT_LABEL               14
#define MPLS_EXTENSION_LABEL               15

/* Minimum and maximum label values */
#define MPLS_MIN_RESERVED_LABEL            0
#define MPLS_MAX_RESERVED_LABEL            15
#define MPLS_MIN_UNRESERVED_LABEL          16
#define MPLS_MAX_UNRESERVED_LABEL          1048575

/* Default min and max SRGB label range */
#define MPLS_DEFAULT_MIN_SRGB_LABEL        16000
#define MPLS_DEFAULT_MAX_SRGB_LABEL        23999

/* Maximum # labels that can be pushed. */
#define MPLS_MAX_LABELS                    16

#define IS_MPLS_RESERVED_LABEL(label)                                          \
	(label >= MPLS_MIN_RESERVED_LABEL && label <= MPLS_MAX_RESERVED_LABEL)

#define IS_MPLS_UNRESERVED_LABEL(label)                                        \
	(label >= MPLS_MIN_UNRESERVED_LABEL                                    \
	 && label <= MPLS_MAX_UNRESERVED_LABEL)

/* Definitions for a MPLS label stack entry (RFC 3032). This encodes the
 * label, EXP, BOS and TTL fields.
 */
typedef unsigned int mpls_lse_t;

#define MPLS_LS_LABEL_MASK             0xFFFFF000
#define MPLS_LS_LABEL_SHIFT            12
#define MPLS_LS_EXP_MASK               0x00000E00
#define MPLS_LS_EXP_SHIFT              9
#define MPLS_LS_S_MASK                 0x00000100
#define MPLS_LS_S_SHIFT                8
#define MPLS_LS_TTL_MASK               0x000000FF
#define MPLS_LS_TTL_SHIFT              0

#define MPLS_LABEL_VALUE(lse)                                                  \
	((lse & MPLS_LS_LABEL_MASK) >> MPLS_LS_LABEL_SHIFT)
#define MPLS_LABEL_EXP(lse) ((lse & MPLS_LS_EXP_MASK) >> MPLS_LS_EXP_SHIFT)
#define MPLS_LABEL_BOS(lse) ((lse & MPLS_LS_S_MASK) >> MPLS_LS_S_SHIFT)
#define MPLS_LABEL_TTL(lse) ((lse & MPLS_LS_TTL_MASK) >> MPLS_LS_TTL_SHIFT)

#define IS_MPLS_LABEL_BOS(ls)          (MPLS_LABEL_BOS(ls) == 1)

#define MPLS_LABEL_LEN_BITS            20

/* MPLS label value as a 32-bit (mostly we only care about the label value). */
typedef unsigned int mpls_label_t;

struct mpls_label_stack {
	uint8_t num_labels;
	uint8_t reserved[3];
	mpls_label_t label[0]; /* 1 or more labels */
};

/* The MPLS explicit-null label is 0 which means when you memset a mpls_label_t
 * to zero you have set that variable to explicit-null which was probably not
 * your intent. The work-around is to use one bit to indicate if the
 * mpls_label_t has been set by the user. MPLS_INVALID_LABEL has this bit clear
 * so that we can use MPLS_INVALID_LABEL to initialize mpls_label_t variables.
 */
#define MPLS_INVALID_LABEL                 0xFFFDFFFF

/* LSP types. */
enum lsp_types_t {
	ZEBRA_LSP_NONE = 0,   /* No LSP. */
	ZEBRA_LSP_STATIC = 1, /* Static LSP. */
	ZEBRA_LSP_LDP = 2,    /* LDP LSP. */
	ZEBRA_LSP_BGP = 3     /* BGP LSP. */
};

/* Functions for basic label operations. */

/* Encode a label stack entry from fields; convert to network byte-order as
 * the Netlink interface expects MPLS labels to be in this format.
 */
static inline mpls_lse_t mpls_lse_encode(mpls_label_t label, u_int32_t ttl,
					 u_int32_t exp, u_int32_t bos)
{
	mpls_lse_t lse;
	lse = htonl((label << MPLS_LS_LABEL_SHIFT) | (exp << MPLS_LS_EXP_SHIFT)
		    | (bos ? (1 << MPLS_LS_S_SHIFT) : 0)
		    | (ttl << MPLS_LS_TTL_SHIFT));
	return lse;
}

/* Extract the fields from a label stack entry after converting to host-byte
 * order. This is expected to be called only for messages received over the
 * Netlink interface.
 */
static inline void mpls_lse_decode(mpls_lse_t lse, mpls_label_t *label,
				   u_int32_t *ttl, u_int32_t *exp,
				   u_int32_t *bos)
{
	mpls_lse_t local_lse;

	local_lse = ntohl(lse);
	*label = MPLS_LABEL_VALUE(local_lse);
	*exp = MPLS_LABEL_EXP(local_lse);
	*bos = MPLS_LABEL_BOS(local_lse);
	*ttl = MPLS_LABEL_TTL(local_lse);
}

/* Invalid label index value (when used with BGP Prefix-SID). Should
 * match the BGP definition.
 */
#define MPLS_INVALID_LABEL_INDEX   0xFFFFFFFF

/* Printable string for labels (with consideration for reserved values). */
static inline char *label2str(mpls_label_t label, char *buf, size_t len)
{
	switch (label) {
	case MPLS_V4_EXP_NULL_LABEL:
		strlcpy(buf, "IPv4 Explicit Null", len);
		return (buf);
	case MPLS_RA_LABEL:
		strlcpy(buf, "Router Alert", len);
		return (buf);
	case MPLS_V6_EXP_NULL_LABEL:
		strlcpy(buf, "IPv6 Explict Null", len);
		return (buf);
	case MPLS_IMP_NULL_LABEL:
		strlcpy(buf, "implicit-null", len);
		return (buf);
	case MPLS_ENTROPY_LABEL_INDICATOR:
		strlcpy(buf, "Entropy Label Indicator", len);
		return (buf);
	case MPLS_GAL_LABEL:
		strlcpy(buf, "Generic Associated Channel", len);
		return (buf);
	case MPLS_OAM_ALERT_LABEL:
		strlcpy(buf, "OAM Alert", len);
		return (buf);
	case MPLS_EXTENSION_LABEL:
		strlcpy(buf, "Extension", len);
		return (buf);
	default:
		if (label < 16)
			snprintf(buf, len, "Reserved (%u)", label);
		else
			snprintf(buf, len, "%u", label);
		return (buf);
	}
}

/* constants used by ldpd */
#define MPLS_LABEL_IPV4NULL	0               /* IPv4 Explicit NULL Label */
#define MPLS_LABEL_RTALERT	1               /* Router Alert Label       */
#define MPLS_LABEL_IPV6NULL	2               /* IPv6 Explicit NULL Label */
#define MPLS_LABEL_IMPLNULL	3               /* Implicit NULL Label      */
	/*      MPLS_LABEL_RESERVED	4-15 */ /* Values 4-15 are reserved */
#define MPLS_LABEL_RESERVED_MAX 15
#define MPLS_LABEL_MAX		((1 << 20) - 1)

#endif
Commit	Line	Data
50f34207	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	*
896014f4 DL	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
50f34207	20	*/
	21
	22	#ifndef _QUAGGA_MPLS_H
	23	#define _QUAGGA_MPLS_H
	24
fea12efb	25	#include <arpa/inet.h>
fea12efb	26
50f34207	27	/* Well-known MPLS label values (RFC 3032 etc). */
	28	#define MPLS_V4_EXP_NULL_LABEL 0
	29	#define MPLS_RA_LABEL 1
	30	#define MPLS_V6_EXP_NULL_LABEL 2
	31	#define MPLS_IMP_NULL_LABEL 3
	32	#define MPLS_ENTROPY_LABEL_INDICATOR 7
	33	#define MPLS_GAL_LABEL 13
	34	#define MPLS_OAM_ALERT_LABEL 14
	35	#define MPLS_EXTENSION_LABEL 15
	36
	37	/* Minimum and maximum label values */
	38	#define MPLS_MIN_RESERVED_LABEL 0
	39	#define MPLS_MAX_RESERVED_LABEL 15
	40	#define MPLS_MIN_UNRESERVED_LABEL 16
	41	#define MPLS_MAX_UNRESERVED_LABEL 1048575
	42
12929668 DS	43	/* Default min and max SRGB label range */
	44	#define MPLS_DEFAULT_MIN_SRGB_LABEL 16000
	45	#define MPLS_DEFAULT_MAX_SRGB_LABEL 23999
	46
52dd3aa4 RW	47	/* Maximum # labels that can be pushed. */
	48	#define MPLS_MAX_LABELS 16
	49
d62a17ae	50	#define IS_MPLS_RESERVED_LABEL(label) \
d62a17ae	51	(label >= MPLS_MIN_RESERVED_LABEL && label <= MPLS_MAX_RESERVED_LABEL)
50f34207	52
d62a17ae	53	#define IS_MPLS_UNRESERVED_LABEL(label) \
	54	(label >= MPLS_MIN_UNRESERVED_LABEL \
	55	&& label <= MPLS_MAX_UNRESERVED_LABEL)
50f34207	56
	57	/* Definitions for a MPLS label stack entry (RFC 3032). This encodes the
	58	* label, EXP, BOS and TTL fields.
	59	*/
	60	typedef unsigned int mpls_lse_t;
	61
	62	#define MPLS_LS_LABEL_MASK 0xFFFFF000
	63	#define MPLS_LS_LABEL_SHIFT 12
	64	#define MPLS_LS_EXP_MASK 0x00000E00
	65	#define MPLS_LS_EXP_SHIFT 9
	66	#define MPLS_LS_S_MASK 0x00000100
	67	#define MPLS_LS_S_SHIFT 8
	68	#define MPLS_LS_TTL_MASK 0x000000FF
	69	#define MPLS_LS_TTL_SHIFT 0
	70
d62a17ae	71	#define MPLS_LABEL_VALUE(lse) \
	72	((lse & MPLS_LS_LABEL_MASK) >> MPLS_LS_LABEL_SHIFT)
	73	#define MPLS_LABEL_EXP(lse) ((lse & MPLS_LS_EXP_MASK) >> MPLS_LS_EXP_SHIFT)
	74	#define MPLS_LABEL_BOS(lse) ((lse & MPLS_LS_S_MASK) >> MPLS_LS_S_SHIFT)
	75	#define MPLS_LABEL_TTL(lse) ((lse & MPLS_LS_TTL_MASK) >> MPLS_LS_TTL_SHIFT)
50f34207	76
	77	#define IS_MPLS_LABEL_BOS(ls) (MPLS_LABEL_BOS(ls) == 1)
	78
	79	#define MPLS_LABEL_LEN_BITS 20
	80
	81	/* MPLS label value as a 32-bit (mostly we only care about the label value). */
	82	typedef unsigned int mpls_label_t;
	83
8ecdb26e DS	84	struct mpls_label_stack {
	85	uint8_t num_labels;
	86	uint8_t reserved[3];
	87	mpls_label_t label[0]; /* 1 or more labels */
	88	};
	89
9bedbb1e DW	90	/* The MPLS explicit-null label is 0 which means when you memset a mpls_label_t
	91	* to zero you have set that variable to explicit-null which was probably not
	92	* your intent. The work-around is to use one bit to indicate if the
	93	* mpls_label_t has been set by the user. MPLS_INVALID_LABEL has this bit clear
	94	* so that we can use MPLS_INVALID_LABEL to initialize mpls_label_t variables.
	95	*/
	96	#define MPLS_INVALID_LABEL 0xFFFDFFFF
50f34207	97
ce549947	98	/* LSP types. */
d62a17ae	99	enum lsp_types_t {
	100	ZEBRA_LSP_NONE = 0, /* No LSP. */
	101	ZEBRA_LSP_STATIC = 1, /* Static LSP. */
	102	ZEBRA_LSP_LDP = 2, /* LDP LSP. */
	103	ZEBRA_LSP_BGP = 3 /* BGP LSP. */
ce549947 RW	104	};
ce549947 RW	105
50f34207	106	/* Functions for basic label operations. */
	107
	108	/* Encode a label stack entry from fields; convert to network byte-order as
	109	* the Netlink interface expects MPLS labels to be in this format.
	110	*/
d62a17ae	111	static inline mpls_lse_t mpls_lse_encode(mpls_label_t label, u_int32_t ttl,
d62a17ae	112	u_int32_t exp, u_int32_t bos)
50f34207	113	{
d62a17ae	114	mpls_lse_t lse;
	115	lse = htonl((label << MPLS_LS_LABEL_SHIFT) \| (exp << MPLS_LS_EXP_SHIFT)
	116	\| (bos ? (1 << MPLS_LS_S_SHIFT) : 0)
	117	\| (ttl << MPLS_LS_TTL_SHIFT));
	118	return lse;
50f34207	119	}
	120
	121	/* Extract the fields from a label stack entry after converting to host-byte
	122	* order. This is expected to be called only for messages received over the
	123	* Netlink interface.
	124	*/
d62a17ae	125	static inline void mpls_lse_decode(mpls_lse_t lse, mpls_label_t *label,
	126	u_int32_t ttl, u_int32_t exp,
	127	u_int32_t *bos)
50f34207	128	{
d62a17ae	129	mpls_lse_t local_lse;
50f34207	130
d62a17ae	131	local_lse = ntohl(lse);
	132	*label = MPLS_LABEL_VALUE(local_lse);
	133	*exp = MPLS_LABEL_EXP(local_lse);
	134	*bos = MPLS_LABEL_BOS(local_lse);
	135	*ttl = MPLS_LABEL_TTL(local_lse);
50f34207	136	}
50f34207	137
28d58fd7 VV	138	/* Invalid label index value (when used with BGP Prefix-SID). Should
	139	* match the BGP definition.
	140	*/
	141	#define MPLS_INVALID_LABEL_INDEX 0xFFFFFFFF
	142
50f34207	143	/* Printable string for labels (with consideration for reserved values). */
d62a17ae	144	static inline char label2str(mpls_label_t label, char buf, size_t len)
50f34207	145	{
d62a17ae	146	switch (label) {
	147	case MPLS_V4_EXP_NULL_LABEL:
	148	strlcpy(buf, "IPv4 Explicit Null", len);
	149	return (buf);
	150	case MPLS_RA_LABEL:
	151	strlcpy(buf, "Router Alert", len);
	152	return (buf);
	153	case MPLS_V6_EXP_NULL_LABEL:
	154	strlcpy(buf, "IPv6 Explict Null", len);
	155	return (buf);
	156	case MPLS_IMP_NULL_LABEL:
	157	strlcpy(buf, "implicit-null", len);
	158	return (buf);
	159	case MPLS_ENTROPY_LABEL_INDICATOR:
	160	strlcpy(buf, "Entropy Label Indicator", len);
	161	return (buf);
	162	case MPLS_GAL_LABEL:
	163	strlcpy(buf, "Generic Associated Channel", len);
	164	return (buf);
	165	case MPLS_OAM_ALERT_LABEL:
	166	strlcpy(buf, "OAM Alert", len);
	167	return (buf);
	168	case MPLS_EXTENSION_LABEL:
	169	strlcpy(buf, "Extension", len);
	170	return (buf);
	171	default:
	172	if (label < 16)
	173	snprintf(buf, len, "Reserved (%u)", label);
	174	else
	175	snprintf(buf, len, "%u", label);
	176	return (buf);
	177	}
50f34207	178	}
50f34207	179
eac6e3f0 RW	180	/* constants used by ldpd */
	181	#define MPLS_LABEL_IPV4NULL 0 /* IPv4 Explicit NULL Label */
	182	#define MPLS_LABEL_RTALERT 1 /* Router Alert Label */
	183	#define MPLS_LABEL_IPV6NULL 2 /* IPv6 Explicit NULL Label */
	184	#define MPLS_LABEL_IMPLNULL 3 /* Implicit NULL Label */
9d303b37	185	/* MPLS_LABEL_RESERVED 4-15 / / Values 4-15 are reserved */
eac6e3f0 RW	186	#define MPLS_LABEL_RESERVED_MAX 15
	187	#define MPLS_LABEL_MAX ((1 << 20) - 1)
	188
50f34207	189	#endif