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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 ext_entry/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_tbl24_entry {
93 /* Stores Next hop or group index (i.e. gindex)into tbl8. */
98 /* Using single uint8_t to store 3 values. */
99 uint8_t valid :1; /**< Validation flag. */
100 uint8_t ext_entry :1; /**< External entry. */
101 uint8_t depth :6; /**< Rule depth. */
104 /** @internal Tbl8 entry structure. */
105 struct rte_lpm_tbl8_entry {
106 uint8_t next_hop; /**< next hop. */
107 /* Using single uint8_t to store 3 values. */
108 uint8_t valid :1; /**< Validation flag. */
109 uint8_t valid_group :1; /**< Group validation flag. */
110 uint8_t depth :6; /**< Rule depth. */
113 struct rte_lpm_tbl24_entry {
115 uint8_t ext_entry :1;
123 struct rte_lpm_tbl8_entry {
125 uint8_t valid_group :1;
131 /** @internal Rule structure. */
132 struct rte_lpm_rule {
133 uint32_t ip; /**< Rule IP address. */
134 uint8_t next_hop; /**< Rule next hop. */
137 /** @internal Contains metadata about the rules table. */
138 struct rte_lpm_rule_info {
139 uint32_t used_rules; /**< Used rules so far. */
140 uint32_t first_rule; /**< Indexes the first rule of a given depth. */
143 /** @internal LPM structure. */
146 char name[RTE_LPM_NAMESIZE]; /**< Name of the lpm. */
147 uint32_t max_rules; /**< Max. balanced rules per lpm. */
148 struct rte_lpm_rule_info rule_info[RTE_LPM_MAX_DEPTH]; /**< Rule info table. */
151 struct rte_lpm_tbl24_entry tbl24[RTE_LPM_TBL24_NUM_ENTRIES] \
152 __rte_cache_aligned; /**< LPM tbl24 table. */
153 struct rte_lpm_tbl8_entry tbl8[RTE_LPM_TBL8_NUM_ENTRIES] \
154 __rte_cache_aligned; /**< LPM tbl8 table. */
155 struct rte_lpm_rule rules_tbl[0] \
156 __rte_cache_aligned; /**< LPM rules. */
160 * Create an LPM object.
165 * NUMA socket ID for LPM table memory allocation
167 * Maximum number of LPM rules that can be added
169 * This parameter is currently unused
171 * Handle to LPM object on success, NULL otherwise with rte_errno set
172 * to an appropriate values. Possible rte_errno values include:
173 * - E_RTE_NO_CONFIG - function could not get pointer to rte_config structure
174 * - E_RTE_SECONDARY - function was called from a secondary process instance
175 * - EINVAL - invalid parameter passed to function
176 * - ENOSPC - the maximum number of memzones has already been allocated
177 * - EEXIST - a memzone with the same name already exists
178 * - ENOMEM - no appropriate memory area found in which to create memzone
181 rte_lpm_create(const char *name, int socket_id, int max_rules, int flags);
184 * Find an existing LPM object and return a pointer to it.
187 * Name of the lpm object as passed to rte_lpm_create()
189 * Pointer to lpm object or NULL if object not found with rte_errno
190 * set appropriately. Possible rte_errno values include:
191 * - ENOENT - required entry not available to return.
194 rte_lpm_find_existing(const char *name);
197 * Free an LPM object.
205 rte_lpm_free(struct rte_lpm *lpm);
208 * Add a rule to the LPM table.
213 * IP of the rule to be added to the LPM table
215 * Depth of the rule to be added to the LPM table
217 * Next hop of the rule to be added to the LPM table
219 * 0 on success, negative value otherwise
222 rte_lpm_add(struct rte_lpm *lpm, uint32_t ip, uint8_t depth, uint8_t next_hop);
225 * Check if a rule is present in the LPM table,
226 * and provide its next hop if it is.
231 * IP of the rule to be searched
233 * Depth of the rule to searched
235 * Next hop of the rule (valid only if it is found)
237 * 1 if the rule exists, 0 if it does not, a negative value on failure
240 rte_lpm_is_rule_present(struct rte_lpm *lpm, uint32_t ip, uint8_t depth,
244 * Delete a rule from the LPM table.
249 * IP of the rule to be deleted from the LPM table
251 * Depth of the rule to be deleted from the LPM table
253 * 0 on success, negative value otherwise
256 rte_lpm_delete(struct rte_lpm *lpm, uint32_t ip, uint8_t depth);
259 * Delete all rules from the LPM table.
265 rte_lpm_delete_all(struct rte_lpm *lpm);
268 * Lookup an IP into the LPM table.
273 * IP to be looked up in the LPM table
275 * Next hop of the most specific rule found for IP (valid on lookup hit only)
277 * -EINVAL for incorrect arguments, -ENOENT on lookup miss, 0 on lookup hit
280 rte_lpm_lookup(struct rte_lpm *lpm, uint32_t ip, uint8_t *next_hop)
282 unsigned tbl24_index = (ip >> 8);
285 /* DEBUG: Check user input arguments. */
286 RTE_LPM_RETURN_IF_TRUE(((lpm == NULL) || (next_hop == NULL)), -EINVAL);
288 /* Copy tbl24 entry */
289 tbl_entry = *(const uint16_t *)&lpm->tbl24[tbl24_index];
291 /* Copy tbl8 entry (only if needed) */
292 if (unlikely((tbl_entry & RTE_LPM_VALID_EXT_ENTRY_BITMASK) ==
293 RTE_LPM_VALID_EXT_ENTRY_BITMASK)) {
295 unsigned tbl8_index = (uint8_t)ip +
296 ((uint8_t)tbl_entry * RTE_LPM_TBL8_GROUP_NUM_ENTRIES);
298 tbl_entry = *(const uint16_t *)&lpm->tbl8[tbl8_index];
301 *next_hop = (uint8_t)tbl_entry;
302 return (tbl_entry & RTE_LPM_LOOKUP_SUCCESS) ? 0 : -ENOENT;
306 * Lookup multiple IP addresses in an LPM table. This may be implemented as a
307 * macro, so the address of the function should not be used.
312 * Array of IPs to be looked up in the LPM table
314 * Next hop of the most specific rule found for IP (valid on lookup hit only).
315 * This is an array of two byte values. The most significant byte in each
316 * value says whether the lookup was successful (bitmask
317 * RTE_LPM_LOOKUP_SUCCESS is set). The least significant byte is the
320 * Number of elements in ips (and next_hops) array to lookup. This should be a
321 * compile time constant, and divisible by 8 for best performance.
323 * -EINVAL for incorrect arguments, otherwise 0
325 #define rte_lpm_lookup_bulk(lpm, ips, next_hops, n) \
326 rte_lpm_lookup_bulk_func(lpm, ips, next_hops, n)
329 rte_lpm_lookup_bulk_func(const struct rte_lpm *lpm, const uint32_t * ips,
330 uint16_t * next_hops, const unsigned n)
333 unsigned tbl24_indexes[n];
335 /* DEBUG: Check user input arguments. */
336 RTE_LPM_RETURN_IF_TRUE(((lpm == NULL) || (ips == NULL) ||
337 (next_hops == NULL)), -EINVAL);
339 for (i = 0; i < n; i++) {
340 tbl24_indexes[i] = ips[i] >> 8;
343 for (i = 0; i < n; i++) {
344 /* Simply copy tbl24 entry to output */
345 next_hops[i] = *(const uint16_t *)&lpm->tbl24[tbl24_indexes[i]];
347 /* Overwrite output with tbl8 entry if needed */
348 if (unlikely((next_hops[i] & RTE_LPM_VALID_EXT_ENTRY_BITMASK) ==
349 RTE_LPM_VALID_EXT_ENTRY_BITMASK)) {
351 unsigned tbl8_index = (uint8_t)ips[i] +
352 ((uint8_t)next_hops[i] *
353 RTE_LPM_TBL8_GROUP_NUM_ENTRIES);
355 next_hops[i] = *(const uint16_t *)&lpm->tbl8[tbl8_index];
361 /* Mask four results. */
362 #define RTE_LPM_MASKX4_RES UINT64_C(0x00ff00ff00ff00ff)
365 * Lookup four IP addresses in an LPM table.
370 * Four IPs to be looked up in the LPM table
372 * Next hop of the most specific rule found for IP (valid on lookup hit only).
373 * This is an 4 elements array of two byte values.
374 * If the lookup was succesfull for the given IP, then least significant byte
375 * of the corresponding element is the actual next hop and the most
376 * significant byte is zero.
377 * If the lookup for the given IP failed, then corresponding element would
378 * contain default value, see description of then next parameter.
380 * Default value to populate into corresponding element of hop[] array,
381 * if lookup would fail.
384 rte_lpm_lookupx4(const struct rte_lpm *lpm, __m128i ip, uint16_t hop[4],
392 const __m128i mask8 =
393 _mm_set_epi32(UINT8_MAX, UINT8_MAX, UINT8_MAX, UINT8_MAX);
396 * RTE_LPM_VALID_EXT_ENTRY_BITMASK for 4 LPM entries
397 * as one 64-bit value (0x0300030003000300).
399 const uint64_t mask_xv =
400 ((uint64_t)RTE_LPM_VALID_EXT_ENTRY_BITMASK |
401 (uint64_t)RTE_LPM_VALID_EXT_ENTRY_BITMASK << 16 |
402 (uint64_t)RTE_LPM_VALID_EXT_ENTRY_BITMASK << 32 |
403 (uint64_t)RTE_LPM_VALID_EXT_ENTRY_BITMASK << 48);
406 * RTE_LPM_LOOKUP_SUCCESS for 4 LPM entries
407 * as one 64-bit value (0x0100010001000100).
409 const uint64_t mask_v =
410 ((uint64_t)RTE_LPM_LOOKUP_SUCCESS |
411 (uint64_t)RTE_LPM_LOOKUP_SUCCESS << 16 |
412 (uint64_t)RTE_LPM_LOOKUP_SUCCESS << 32 |
413 (uint64_t)RTE_LPM_LOOKUP_SUCCESS << 48);
415 /* get 4 indexes for tbl24[]. */
416 i24 = _mm_srli_epi32(ip, CHAR_BIT);
418 /* extract values from tbl24[] */
419 idx = _mm_cvtsi128_si64(i24);
420 i24 = _mm_srli_si128(i24, sizeof(uint64_t));
422 tbl[0] = *(const uint16_t *)&lpm->tbl24[(uint32_t)idx];
423 tbl[1] = *(const uint16_t *)&lpm->tbl24[idx >> 32];
425 idx = _mm_cvtsi128_si64(i24);
427 tbl[2] = *(const uint16_t *)&lpm->tbl24[(uint32_t)idx];
428 tbl[3] = *(const uint16_t *)&lpm->tbl24[idx >> 32];
430 /* get 4 indexes for tbl8[]. */
431 i8.x = _mm_and_si128(ip, mask8);
433 pt = (uint64_t)tbl[0] |
434 (uint64_t)tbl[1] << 16 |
435 (uint64_t)tbl[2] << 32 |
436 (uint64_t)tbl[3] << 48;
438 /* search successfully finished for all 4 IP addresses. */
439 if (likely((pt & mask_xv) == mask_v)) {
440 uintptr_t ph = (uintptr_t)hop;
441 *(uint64_t *)ph = pt & RTE_LPM_MASKX4_RES;
445 if (unlikely((pt & RTE_LPM_VALID_EXT_ENTRY_BITMASK) ==
446 RTE_LPM_VALID_EXT_ENTRY_BITMASK)) {
447 i8.u32[0] = i8.u32[0] +
448 (uint8_t)tbl[0] * RTE_LPM_TBL8_GROUP_NUM_ENTRIES;
449 tbl[0] = *(const uint16_t *)&lpm->tbl8[i8.u32[0]];
451 if (unlikely((pt >> 16 & RTE_LPM_VALID_EXT_ENTRY_BITMASK) ==
452 RTE_LPM_VALID_EXT_ENTRY_BITMASK)) {
453 i8.u32[1] = i8.u32[1] +
454 (uint8_t)tbl[1] * RTE_LPM_TBL8_GROUP_NUM_ENTRIES;
455 tbl[1] = *(const uint16_t *)&lpm->tbl8[i8.u32[1]];
457 if (unlikely((pt >> 32 & RTE_LPM_VALID_EXT_ENTRY_BITMASK) ==
458 RTE_LPM_VALID_EXT_ENTRY_BITMASK)) {
459 i8.u32[2] = i8.u32[2] +
460 (uint8_t)tbl[2] * RTE_LPM_TBL8_GROUP_NUM_ENTRIES;
461 tbl[2] = *(const uint16_t *)&lpm->tbl8[i8.u32[2]];
463 if (unlikely((pt >> 48 & RTE_LPM_VALID_EXT_ENTRY_BITMASK) ==
464 RTE_LPM_VALID_EXT_ENTRY_BITMASK)) {
465 i8.u32[3] = i8.u32[3] +
466 (uint8_t)tbl[3] * RTE_LPM_TBL8_GROUP_NUM_ENTRIES;
467 tbl[3] = *(const uint16_t *)&lpm->tbl8[i8.u32[3]];
470 hop[0] = (tbl[0] & RTE_LPM_LOOKUP_SUCCESS) ? (uint8_t)tbl[0] : defv;
471 hop[1] = (tbl[1] & RTE_LPM_LOOKUP_SUCCESS) ? (uint8_t)tbl[1] : defv;
472 hop[2] = (tbl[2] & RTE_LPM_LOOKUP_SUCCESS) ? (uint8_t)tbl[2] : defv;
473 hop[3] = (tbl[3] & RTE_LPM_LOOKUP_SUCCESS) ? (uint8_t)tbl[3] : defv;
480 #endif /* _RTE_LPM_H_ */