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39 * RTE Longest Prefix Match (LPM)
43 #include <sys/queue.h>
46 #include <rte_branch_prediction.h>
47 #include <rte_byteorder.h>
48 #include <rte_memory.h>
49 #include <rte_common.h>
56 /** Max number of characters in LPM name. */
57 #define RTE_LPM_NAMESIZE 32
59 /** Maximum depth value possible for IPv4 LPM. */
60 #define RTE_LPM_MAX_DEPTH 32
62 /** @internal Total number of tbl24 entries. */
63 #define RTE_LPM_TBL24_NUM_ENTRIES (1 << 24)
65 /** @internal Number of entries in a tbl8 group. */
66 #define RTE_LPM_TBL8_GROUP_NUM_ENTRIES 256
68 /** @internal Total number of tbl8 groups in the tbl8. */
69 #define RTE_LPM_TBL8_NUM_GROUPS 256
71 /** @internal Total number of tbl8 entries. */
72 #define RTE_LPM_TBL8_NUM_ENTRIES (RTE_LPM_TBL8_NUM_GROUPS * \
73 RTE_LPM_TBL8_GROUP_NUM_ENTRIES)
75 /** @internal Macro to enable/disable run-time checks. */
76 #if defined(RTE_LIBRTE_LPM_DEBUG)
77 #define RTE_LPM_RETURN_IF_TRUE(cond, retval) do { \
78 if (cond) return (retval); \
81 #define RTE_LPM_RETURN_IF_TRUE(cond, retval)
84 /** @internal bitmask with valid and valid_group fields set */
85 #define RTE_LPM_VALID_EXT_ENTRY_BITMASK 0x0300
87 /** Bitmask used to indicate successful lookup */
88 #define RTE_LPM_LOOKUP_SUCCESS 0x0100
90 #if RTE_BYTE_ORDER == RTE_LITTLE_ENDIAN
91 /** @internal Tbl24 entry structure. */
92 struct rte_lpm_tbl_entry {
94 * Stores Next hop (tbl8 or tbl24 when valid_group is not set) or
95 * a group index pointing to a tbl8 structure (tbl24 only, when
102 /* Using single uint8_t to store 3 values. */
103 uint8_t valid :1; /**< Validation flag. */
106 * - valid_group == 0: entry stores a next hop
107 * - valid_group == 1: entry stores a group_index pointing to a tbl8
109 * - valid_group indicates whether the current tbl8 is in use or not
111 uint8_t valid_group :1;
112 uint8_t depth :6; /**< Rule depth. */
116 struct rte_lpm_tbl_entry {
118 uint8_t valid_group :1;
128 /** @internal Rule structure. */
129 struct rte_lpm_rule {
130 uint32_t ip; /**< Rule IP address. */
131 uint8_t next_hop; /**< Rule next hop. */
134 /** @internal Contains metadata about the rules table. */
135 struct rte_lpm_rule_info {
136 uint32_t used_rules; /**< Used rules so far. */
137 uint32_t first_rule; /**< Indexes the first rule of a given depth. */
140 /** @internal LPM structure. */
143 char name[RTE_LPM_NAMESIZE]; /**< Name of the lpm. */
144 uint32_t max_rules; /**< Max. balanced rules per lpm. */
145 struct rte_lpm_rule_info rule_info[RTE_LPM_MAX_DEPTH]; /**< Rule info table. */
148 struct rte_lpm_tbl_entry tbl24[RTE_LPM_TBL24_NUM_ENTRIES]
149 __rte_cache_aligned; /**< LPM tbl24 table. */
150 struct rte_lpm_tbl_entry tbl8[RTE_LPM_TBL8_NUM_ENTRIES]
151 __rte_cache_aligned; /**< LPM tbl8 table. */
152 struct rte_lpm_rule rules_tbl[0] \
153 __rte_cache_aligned; /**< LPM rules. */
157 * Create an LPM object.
162 * NUMA socket ID for LPM table memory allocation
164 * Maximum number of LPM rules that can be added
166 * This parameter is currently unused
168 * Handle to LPM object on success, NULL otherwise with rte_errno set
169 * to an appropriate values. Possible rte_errno values include:
170 * - E_RTE_NO_CONFIG - function could not get pointer to rte_config structure
171 * - E_RTE_SECONDARY - function was called from a secondary process instance
172 * - EINVAL - invalid parameter passed to function
173 * - ENOSPC - the maximum number of memzones has already been allocated
174 * - EEXIST - a memzone with the same name already exists
175 * - ENOMEM - no appropriate memory area found in which to create memzone
178 rte_lpm_create(const char *name, int socket_id, int max_rules, int flags);
181 * Find an existing LPM object and return a pointer to it.
184 * Name of the lpm object as passed to rte_lpm_create()
186 * Pointer to lpm object or NULL if object not found with rte_errno
187 * set appropriately. Possible rte_errno values include:
188 * - ENOENT - required entry not available to return.
191 rte_lpm_find_existing(const char *name);
194 * Free an LPM object.
202 rte_lpm_free(struct rte_lpm *lpm);
205 * Add a rule to the LPM table.
210 * IP of the rule to be added to the LPM table
212 * Depth of the rule to be added to the LPM table
214 * Next hop of the rule to be added to the LPM table
216 * 0 on success, negative value otherwise
219 rte_lpm_add(struct rte_lpm *lpm, uint32_t ip, uint8_t depth, uint8_t next_hop);
222 * Check if a rule is present in the LPM table,
223 * and provide its next hop if it is.
228 * IP of the rule to be searched
230 * Depth of the rule to searched
232 * Next hop of the rule (valid only if it is found)
234 * 1 if the rule exists, 0 if it does not, a negative value on failure
237 rte_lpm_is_rule_present(struct rte_lpm *lpm, uint32_t ip, uint8_t depth,
241 * Delete a rule from the LPM table.
246 * IP of the rule to be deleted from the LPM table
248 * Depth of the rule to be deleted from the LPM table
250 * 0 on success, negative value otherwise
253 rte_lpm_delete(struct rte_lpm *lpm, uint32_t ip, uint8_t depth);
256 * Delete all rules from the LPM table.
262 rte_lpm_delete_all(struct rte_lpm *lpm);
265 * Lookup an IP into the LPM table.
270 * IP to be looked up in the LPM table
272 * Next hop of the most specific rule found for IP (valid on lookup hit only)
274 * -EINVAL for incorrect arguments, -ENOENT on lookup miss, 0 on lookup hit
277 rte_lpm_lookup(struct rte_lpm *lpm, uint32_t ip, uint8_t *next_hop)
279 unsigned tbl24_index = (ip >> 8);
282 /* DEBUG: Check user input arguments. */
283 RTE_LPM_RETURN_IF_TRUE(((lpm == NULL) || (next_hop == NULL)), -EINVAL);
285 /* Copy tbl24 entry */
286 tbl_entry = *(const uint16_t *)&lpm->tbl24[tbl24_index];
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)) {
292 unsigned tbl8_index = (uint8_t)ip +
293 ((uint8_t)tbl_entry * RTE_LPM_TBL8_GROUP_NUM_ENTRIES);
295 tbl_entry = *(const uint16_t *)&lpm->tbl8[tbl8_index];
298 *next_hop = (uint8_t)tbl_entry;
299 return (tbl_entry & RTE_LPM_LOOKUP_SUCCESS) ? 0 : -ENOENT;
303 * Lookup multiple IP addresses in an LPM table. This may be implemented as a
304 * macro, so the address of the function should not be used.
309 * Array of IPs to be looked up in the LPM table
311 * Next hop of the most specific rule found for IP (valid on lookup hit only).
312 * This is an array of two byte values. The most significant byte in each
313 * value says whether the lookup was successful (bitmask
314 * RTE_LPM_LOOKUP_SUCCESS is set). The least significant byte is the
317 * Number of elements in ips (and next_hops) array to lookup. This should be a
318 * compile time constant, and divisible by 8 for best performance.
320 * -EINVAL for incorrect arguments, otherwise 0
322 #define rte_lpm_lookup_bulk(lpm, ips, next_hops, n) \
323 rte_lpm_lookup_bulk_func(lpm, ips, next_hops, n)
326 rte_lpm_lookup_bulk_func(const struct rte_lpm *lpm, const uint32_t * ips,
327 uint16_t * next_hops, const unsigned n)
330 unsigned tbl24_indexes[n];
332 /* DEBUG: Check user input arguments. */
333 RTE_LPM_RETURN_IF_TRUE(((lpm == NULL) || (ips == NULL) ||
334 (next_hops == NULL)), -EINVAL);
336 for (i = 0; i < n; i++) {
337 tbl24_indexes[i] = ips[i] >> 8;
340 for (i = 0; i < n; i++) {
341 /* Simply copy tbl24 entry to output */
342 next_hops[i] = *(const uint16_t *)&lpm->tbl24[tbl24_indexes[i]];
344 /* Overwrite output with tbl8 entry if needed */
345 if (unlikely((next_hops[i] & RTE_LPM_VALID_EXT_ENTRY_BITMASK) ==
346 RTE_LPM_VALID_EXT_ENTRY_BITMASK)) {
348 unsigned tbl8_index = (uint8_t)ips[i] +
349 ((uint8_t)next_hops[i] *
350 RTE_LPM_TBL8_GROUP_NUM_ENTRIES);
352 next_hops[i] = *(const uint16_t *)&lpm->tbl8[tbl8_index];
358 /* Mask four results. */
359 #define RTE_LPM_MASKX4_RES UINT64_C(0x00ff00ff00ff00ff)
362 * Lookup four IP addresses in an LPM table.
367 * Four IPs to be looked up in the LPM table
369 * Next hop of the most specific rule found for IP (valid on lookup hit only).
370 * This is an 4 elements array of two byte values.
371 * If the lookup was succesfull for the given IP, then least significant byte
372 * of the corresponding element is the actual next hop and the most
373 * significant byte is zero.
374 * If the lookup for the given IP failed, then corresponding element would
375 * contain default value, see description of then next parameter.
377 * Default value to populate into corresponding element of hop[] array,
378 * if lookup would fail.
381 rte_lpm_lookupx4(const struct rte_lpm *lpm, __m128i ip, uint16_t hop[4],
389 const __m128i mask8 =
390 _mm_set_epi32(UINT8_MAX, UINT8_MAX, UINT8_MAX, UINT8_MAX);
393 * RTE_LPM_VALID_EXT_ENTRY_BITMASK for 4 LPM entries
394 * as one 64-bit value (0x0300030003000300).
396 const uint64_t mask_xv =
397 ((uint64_t)RTE_LPM_VALID_EXT_ENTRY_BITMASK |
398 (uint64_t)RTE_LPM_VALID_EXT_ENTRY_BITMASK << 16 |
399 (uint64_t)RTE_LPM_VALID_EXT_ENTRY_BITMASK << 32 |
400 (uint64_t)RTE_LPM_VALID_EXT_ENTRY_BITMASK << 48);
403 * RTE_LPM_LOOKUP_SUCCESS for 4 LPM entries
404 * as one 64-bit value (0x0100010001000100).
406 const uint64_t mask_v =
407 ((uint64_t)RTE_LPM_LOOKUP_SUCCESS |
408 (uint64_t)RTE_LPM_LOOKUP_SUCCESS << 16 |
409 (uint64_t)RTE_LPM_LOOKUP_SUCCESS << 32 |
410 (uint64_t)RTE_LPM_LOOKUP_SUCCESS << 48);
412 /* get 4 indexes for tbl24[]. */
413 i24 = _mm_srli_epi32(ip, CHAR_BIT);
415 /* extract values from tbl24[] */
416 idx = _mm_cvtsi128_si64(i24);
417 i24 = _mm_srli_si128(i24, sizeof(uint64_t));
419 tbl[0] = *(const uint16_t *)&lpm->tbl24[(uint32_t)idx];
420 tbl[1] = *(const uint16_t *)&lpm->tbl24[idx >> 32];
422 idx = _mm_cvtsi128_si64(i24);
424 tbl[2] = *(const uint16_t *)&lpm->tbl24[(uint32_t)idx];
425 tbl[3] = *(const uint16_t *)&lpm->tbl24[idx >> 32];
427 /* get 4 indexes for tbl8[]. */
428 i8.x = _mm_and_si128(ip, mask8);
430 pt = (uint64_t)tbl[0] |
431 (uint64_t)tbl[1] << 16 |
432 (uint64_t)tbl[2] << 32 |
433 (uint64_t)tbl[3] << 48;
435 /* search successfully finished for all 4 IP addresses. */
436 if (likely((pt & mask_xv) == mask_v)) {
437 uintptr_t ph = (uintptr_t)hop;
438 *(uint64_t *)ph = pt & RTE_LPM_MASKX4_RES;
442 if (unlikely((pt & RTE_LPM_VALID_EXT_ENTRY_BITMASK) ==
443 RTE_LPM_VALID_EXT_ENTRY_BITMASK)) {
444 i8.u32[0] = i8.u32[0] +
445 (uint8_t)tbl[0] * RTE_LPM_TBL8_GROUP_NUM_ENTRIES;
446 tbl[0] = *(const uint16_t *)&lpm->tbl8[i8.u32[0]];
448 if (unlikely((pt >> 16 & RTE_LPM_VALID_EXT_ENTRY_BITMASK) ==
449 RTE_LPM_VALID_EXT_ENTRY_BITMASK)) {
450 i8.u32[1] = i8.u32[1] +
451 (uint8_t)tbl[1] * RTE_LPM_TBL8_GROUP_NUM_ENTRIES;
452 tbl[1] = *(const uint16_t *)&lpm->tbl8[i8.u32[1]];
454 if (unlikely((pt >> 32 & RTE_LPM_VALID_EXT_ENTRY_BITMASK) ==
455 RTE_LPM_VALID_EXT_ENTRY_BITMASK)) {
456 i8.u32[2] = i8.u32[2] +
457 (uint8_t)tbl[2] * RTE_LPM_TBL8_GROUP_NUM_ENTRIES;
458 tbl[2] = *(const uint16_t *)&lpm->tbl8[i8.u32[2]];
460 if (unlikely((pt >> 48 & RTE_LPM_VALID_EXT_ENTRY_BITMASK) ==
461 RTE_LPM_VALID_EXT_ENTRY_BITMASK)) {
462 i8.u32[3] = i8.u32[3] +
463 (uint8_t)tbl[3] * RTE_LPM_TBL8_GROUP_NUM_ENTRIES;
464 tbl[3] = *(const uint16_t *)&lpm->tbl8[i8.u32[3]];
467 hop[0] = (tbl[0] & RTE_LPM_LOOKUP_SUCCESS) ? (uint8_t)tbl[0] : defv;
468 hop[1] = (tbl[1] & RTE_LPM_LOOKUP_SUCCESS) ? (uint8_t)tbl[1] : defv;
469 hop[2] = (tbl[2] & RTE_LPM_LOOKUP_SUCCESS) ? (uint8_t)tbl[2] : defv;
470 hop[3] = (tbl[3] & RTE_LPM_LOOKUP_SUCCESS) ? (uint8_t)tbl[3] : defv;
477 #endif /* _RTE_LPM_H_ */