1/* SPDX-License-Identifier: BSD-3-Clause
2 * Copyright(c) 2010-2014 Intel Corporation
3 */
4
5#ifndef _RTE_LPM_H_
6#define _RTE_LPM_H_
7
8/**
9 * @file
10 * RTE Longest Prefix Match (LPM)
11 */
12
13/*
14#include <errno.h>
15#include <sys/queue.h>
16#include <stdint.h>
17#include <stdlib.h>
18#include <rte_branch_prediction.h>
19#include <rte_byteorder.h>
20#include <rte_config.h>
21#include <rte_memory.h>
22#include <rte_common.h>
23#include <rte_vect.h>
24*/
25#include "rte_branch_prediction.h"
26
27#ifdef __cplusplus
28extern "C" {
29#endif
30
31/** Max number of characters in LPM name. */
32#define RTE_LPM_NAMESIZE                16
33
34/** Maximum depth value possible for IPv4 LPM. */
35#define RTE_LPM_MAX_DEPTH               32
36
37/** @internal Total number of tbl24 entries. */
38#define RTE_LPM_TBL24_NUM_ENTRIES       (1 << 24)
39
40/** @internal Number of entries in a tbl8 group. */
41#define RTE_LPM_TBL8_GROUP_NUM_ENTRIES  256
42
43/** @internal Max number of tbl8 groups in the tbl8. */
44#define RTE_LPM_MAX_TBL8_NUM_GROUPS         (1 << 24)
45
46/** @internal Total number of tbl8 groups in the tbl8. */
47#define RTE_LPM_TBL8_NUM_GROUPS         256
48
49/** @internal Total number of tbl8 entries. */
50#define RTE_LPM_TBL8_NUM_ENTRIES        (RTE_LPM_TBL8_NUM_GROUPS * \
51					RTE_LPM_TBL8_GROUP_NUM_ENTRIES)
52
53/** @internal Macro to enable/disable run-time checks. */
54#if defined(RTE_LIBRTE_LPM_DEBUG)
55#define RTE_LPM_RETURN_IF_TRUE(cond, retval) do { \
56	if (cond) return (retval);                \
57} while (0)
58#else
59#define RTE_LPM_RETURN_IF_TRUE(cond, retval)
60#endif
61
62/** @internal bitmask with valid and valid_group fields set */
63#define RTE_LPM_VALID_EXT_ENTRY_BITMASK 0x03000000
64
65/** Bitmask used to indicate successful lookup */
66#define RTE_LPM_LOOKUP_SUCCESS          0x01000000
67
68#if RTE_BYTE_ORDER == RTE_LITTLE_ENDIAN
69/** @internal Tbl24 entry structure. */
70__extension__
71struct rte_lpm_tbl_entry {
72	/**
73	 * Stores Next hop (tbl8 or tbl24 when valid_group is not set) or
74	 * a group index pointing to a tbl8 structure (tbl24 only, when
75	 * valid_group is set)
76	 */
77	uint32_t next_hop    :24;
78	/* Using single uint8_t to store 3 values. */
79	uint32_t valid       :1;   /**< Validation flag. */
80	/**
81	 * For tbl24:
82	 *  - valid_group == 0: entry stores a next hop
83	 *  - valid_group == 1: entry stores a group_index pointing to a tbl8
84	 * For tbl8:
85	 *  - valid_group indicates whether the current tbl8 is in use or not
86	 */
87	uint32_t valid_group :1;
88	uint32_t depth       :6; /**< Rule depth. */
89};
90
91#else
92
93__extension__
94struct rte_lpm_tbl_entry {
95	uint32_t depth       :6;
96	uint32_t valid_group :1;
97	uint32_t valid       :1;
98	uint32_t next_hop    :24;
99
100};
101
102#endif
103
104/** LPM configuration structure. */
105struct rte_lpm_config {
106	uint32_t max_rules;      /**< Max number of rules. */
107	uint32_t number_tbl8s;   /**< Number of tbl8s to allocate. */
108	int flags;               /**< This field is currently unused. */
109};
110
111/** @internal Rule structure. */
112struct rte_lpm_rule {
113	uint32_t ip; /**< Rule IP address. */
114	uint32_t next_hop; /**< Rule next hop. */
115};
116
117/** @internal Contains metadata about the rules table. */
118struct rte_lpm_rule_info {
119	uint32_t used_rules; /**< Used rules so far. */
120	uint32_t first_rule; /**< Indexes the first rule of a given depth. */
121};
122
123struct nhop_object;
124struct rte_lpm_external {
125	struct nhop_object	**nh_idx;	/**< # -> idx mappings  */
126	uint32_t		default_idx;	/* nhop index of default route */
127	uint32_t		fibnum;		/* fib index */
128};
129
130/** @internal LPM structure. */
131struct rte_lpm {
132	/* LPM metadata. */
133	struct rte_lpm_external ext;
134	char name[RTE_LPM_NAMESIZE];        /**< Name of the lpm. */
135	uint32_t max_rules; /**< Max. balanced rules per lpm. */
136	uint32_t number_tbl8s; /**< Number of tbl8s. */
137	struct rte_lpm_rule_info rule_info[RTE_LPM_MAX_DEPTH]; /**< Rule info table. */
138
139	/* LPM Tables. */
140	struct rte_lpm_tbl_entry tbl24[RTE_LPM_TBL24_NUM_ENTRIES]
141			__rte_cache_aligned; /**< LPM tbl24 table. */
142	struct rte_lpm_tbl_entry *tbl8; /**< LPM tbl8 table. */
143	struct rte_lpm_rule *rules_tbl; /**< LPM rules. */
144};
145
146/**
147 * Create an LPM object.
148 *
149 * @param name
150 *   LPM object name
151 * @param socket_id
152 *   NUMA socket ID for LPM table memory allocation
153 * @param config
154 *   Structure containing the configuration
155 * @return
156 *   Handle to LPM object on success, NULL otherwise with rte_errno set
157 *   to an appropriate values. Possible rte_errno values include:
158 *    - E_RTE_NO_CONFIG - function could not get pointer to rte_config structure
159 *    - E_RTE_SECONDARY - function was called from a secondary process instance
160 *    - EINVAL - invalid parameter passed to function
161 *    - ENOSPC - the maximum number of memzones has already been allocated
162 *    - EEXIST - a memzone with the same name already exists
163 *    - ENOMEM - no appropriate memory area found in which to create memzone
164 */
165struct rte_lpm *
166rte_lpm_create(const char *name, int socket_id,
167		const struct rte_lpm_config *config);
168
169/**
170 * Find an existing LPM object and return a pointer to it.
171 *
172 * @param name
173 *   Name of the lpm object as passed to rte_lpm_create()
174 * @return
175 *   Pointer to lpm object or NULL if object not found with rte_errno
176 *   set appropriately. Possible rte_errno values include:
177 *    - ENOENT - required entry not available to return.
178 */
179struct rte_lpm *
180rte_lpm_find_existing(const char *name);
181
182/**
183 * Free an LPM object.
184 *
185 * @param lpm
186 *   LPM object handle
187 * @return
188 *   None
189 */
190void
191rte_lpm_free(struct rte_lpm *lpm);
192
193/**
194 * Add a rule to the LPM table.
195 *
196 * @param lpm
197 *   LPM object handle
198 * @param ip
199 *   IP of the rule to be added to the LPM table
200 * @param depth
201 *   Depth of the rule to be added to the LPM table
202 * @param next_hop
203 *   Next hop of the rule to be added to the LPM table
204 * @return
205 *   0 on success, negative value otherwise
206 */
207int
208rte_lpm_add(struct rte_lpm *lpm, uint32_t ip, uint8_t depth, uint32_t next_hop);
209
210/**
211 * Check if a rule is present in the LPM table,
212 * and provide its next hop if it is.
213 *
214 * @param lpm
215 *   LPM object handle
216 * @param ip
217 *   IP of the rule to be searched
218 * @param depth
219 *   Depth of the rule to searched
220 * @param next_hop
221 *   Next hop of the rule (valid only if it is found)
222 * @return
223 *   1 if the rule exists, 0 if it does not, a negative value on failure
224 */
225int
226rte_lpm_is_rule_present(struct rte_lpm *lpm, uint32_t ip, uint8_t depth,
227uint32_t *next_hop);
228
229/**
230 * Delete a rule from the LPM table.
231 *
232 * @param lpm
233 *   LPM object handle
234 * @param ip
235 *   IP of the rule to be deleted from the LPM table
236 * @param depth
237 *   Depth of the rule to be deleted from the LPM table
238 * @param psub_rule_depth
239 *   Pointer to depth of the parent rule
240 * @param sub_rule_nhop
241 *   Pinter to the parent rule nexthop index
242 * @return
243 *   0 on success, negative value otherwise
244 */
245int
246rte_lpm_delete(struct rte_lpm *lpm, uint32_t ip, uint8_t depth,
247	uint8_t sub_rule_depth, uint32_t sub_rule_nhop);
248
249/**
250 * Delete all rules from the LPM table.
251 *
252 * @param lpm
253 *   LPM object handle
254 */
255void
256rte_lpm_delete_all(struct rte_lpm *lpm);
257
258/**
259 * Lookup an IP into the LPM table.
260 *
261 * @param lpm
262 *   LPM object handle
263 * @param ip
264 *   IP to be looked up in the LPM table
265 * @param next_hop
266 *   Next hop of the most specific rule found for IP (valid on lookup hit only)
267 * @return
268 *   -EINVAL for incorrect arguments, -ENOENT on lookup miss, 0 on lookup hit
269 */
270static inline int
271rte_lpm_lookup(struct rte_lpm *lpm, uint32_t ip, uint32_t *next_hop)
272{
273	unsigned tbl24_index = (ip >> 8);
274	uint32_t tbl_entry;
275	const uint32_t *ptbl;
276
277	/* DEBUG: Check user input arguments. */
278	RTE_LPM_RETURN_IF_TRUE(((lpm == NULL) || (next_hop == NULL)), -EINVAL);
279
280	/* Copy tbl24 entry */
281	ptbl = (const uint32_t *)(&lpm->tbl24[tbl24_index]);
282	tbl_entry = *ptbl;
283
284	/* Memory ordering is not required in lookup. Because dataflow
285	 * dependency exists, compiler or HW won't be able to re-order
286	 * the operations.
287	 */
288	/* Copy tbl8 entry (only if needed) */
289	if (unlikely((tbl_entry & RTE_LPM_VALID_EXT_ENTRY_BITMASK) ==
290			RTE_LPM_VALID_EXT_ENTRY_BITMASK)) {
291
292		unsigned tbl8_index = (uint8_t)ip +
293				(((uint32_t)tbl_entry & 0x00FFFFFF) *
294						RTE_LPM_TBL8_GROUP_NUM_ENTRIES);
295
296		ptbl = (const uint32_t *)&lpm->tbl8[tbl8_index];
297		tbl_entry = *ptbl;
298	}
299
300	*next_hop = ((uint32_t)tbl_entry & 0x00FFFFFF);
301	return (tbl_entry & RTE_LPM_LOOKUP_SUCCESS) ? 0 : -ENOENT;
302}
303
304/**
305 * Lookup multiple IP addresses in an LPM table. This may be implemented as a
306 * macro, so the address of the function should not be used.
307 *
308 * @param lpm
309 *   LPM object handle
310 * @param ips
311 *   Array of IPs to be looked up in the LPM table
312 * @param next_hops
313 *   Next hop of the most specific rule found for IP (valid on lookup hit only).
314 *   This is an array of two byte values. The most significant byte in each
315 *   value says whether the lookup was successful (bitmask
316 *   RTE_LPM_LOOKUP_SUCCESS is set). The least significant byte is the
317 *   actual next hop.
318 * @param n
319 *   Number of elements in ips (and next_hops) array to lookup. This should be a
320 *   compile time constant, and divisible by 8 for best performance.
321 *  @return
322 *   -EINVAL for incorrect arguments, otherwise 0
323 */
324#define rte_lpm_lookup_bulk(lpm, ips, next_hops, n) \
325		rte_lpm_lookup_bulk_func(lpm, ips, next_hops, n)
326
327static inline int
328rte_lpm_lookup_bulk_func(const struct rte_lpm *lpm, const uint32_t *ips,
329		uint32_t *next_hops, const unsigned n)
330{
331	unsigned i;
332	unsigned tbl24_indexes[n];
333	const uint32_t *ptbl;
334
335	/* DEBUG: Check user input arguments. */
336	RTE_LPM_RETURN_IF_TRUE(((lpm == NULL) || (ips == NULL) ||
337			(next_hops == NULL)), -EINVAL);
338
339	for (i = 0; i < n; i++) {
340		tbl24_indexes[i] = ips[i] >> 8;
341	}
342
343	for (i = 0; i < n; i++) {
344		/* Simply copy tbl24 entry to output */
345		ptbl = (const uint32_t *)&lpm->tbl24[tbl24_indexes[i]];
346		next_hops[i] = *ptbl;
347
348		/* Overwrite output with tbl8 entry if needed */
349		if (unlikely((next_hops[i] & RTE_LPM_VALID_EXT_ENTRY_BITMASK) ==
350				RTE_LPM_VALID_EXT_ENTRY_BITMASK)) {
351
352			unsigned tbl8_index = (uint8_t)ips[i] +
353					(((uint32_t)next_hops[i] & 0x00FFFFFF) *
354					 RTE_LPM_TBL8_GROUP_NUM_ENTRIES);
355
356			ptbl = (const uint32_t *)&lpm->tbl8[tbl8_index];
357			next_hops[i] = *ptbl;
358		}
359	}
360	return 0;
361}
362
363/* Mask four results. */
364#define	 RTE_LPM_MASKX4_RES	UINT64_C(0x00ffffff00ffffff)
365
366/**
367 * Lookup four IP addresses in an LPM table.
368 *
369 * @param lpm
370 *   LPM object handle
371 * @param ip
372 *   Four IPs to be looked up in the LPM table
373 * @param hop
374 *   Next hop of the most specific rule found for IP (valid on lookup hit only).
375 *   This is an 4 elements array of two byte values.
376 *   If the lookup was successful for the given IP, then least significant byte
377 *   of the corresponding element is the  actual next hop and the most
378 *   significant byte is zero.
379 *   If the lookup for the given IP failed, then corresponding element would
380 *   contain default value, see description of then next parameter.
381 * @param defv
382 *   Default value to populate into corresponding element of hop[] array,
383 *   if lookup would fail.
384 */
385#if 0
386static inline void
387rte_lpm_lookupx4(const struct rte_lpm *lpm, xmm_t ip, uint32_t hop[4],
388	uint32_t defv);
389
390#if defined(RTE_ARCH_ARM) || defined(RTE_ARCH_ARM64)
391#include "rte_lpm_neon.h"
392#elif defined(RTE_ARCH_PPC_64)
393#include "rte_lpm_altivec.h"
394#else
395#include "rte_lpm_sse.h"
396#endif
397#endif
398
399#ifdef __cplusplus
400}
401#endif
402
403#endif /* _RTE_LPM_H_ */
404