Differential D27412 Diff 80704 sys/contrib/dpdk_rte_lpm/rte_lpm.c

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sys/contrib/dpdk_rte_lpm/rte_lpm.c

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				/* SPDX-License-Identifier: BSD-3-Clause
				* Copyright(c) 2010-2014 Intel Corporation
				*/

				#include <sys/param.h>
				#include <sys/ctype.h>
				#include <sys/systm.h>
				#include <sys/lock.h>
				#include <sys/rwlock.h>
				#include <sys/malloc.h>
				#include <sys/mbuf.h>
				#include <sys/socket.h>
				#include <sys/kernel.h>

				int errno = 0, rte_errno = 0;

				#if 0
				#include <string.h>
				#include <stdint.h>
				#include <errno.h>
				#include <stdarg.h>
				#include <stdio.h>
				#include <sys/queue.h>

				#include <rte_log.h>
				#include <rte_branch_prediction.h>
				#include <rte_common.h>
				#include <rte_memory.h> /* for definition of RTE_CACHE_LINE_SIZE */
				#include <rte_malloc.h>
				#include <rte_eal.h>
				#include <rte_eal_memconfig.h>
				#include <rte_per_lcore.h>
				#include <rte_string_fns.h>
				#include <rte_errno.h>
				#include <rte_rwlock.h>
				#include <rte_spinlock.h>
				#include <rte_tailq.h>
				#endif

				#include "rte_shim.h"
				#include "rte_lpm.h"

				#if 0
				TAILQ_HEAD(rte_lpm_list, rte_tailq_entry);

				static struct rte_tailq_elem rte_lpm_tailq = {
				.name = "RTE_LPM",
				};
				EAL_REGISTER_TAILQ(rte_lpm_tailq)
				#endif

				#define MAX_DEPTH_TBL24 24

				enum valid_flag {
				INVALID = 0,
				VALID
				};

				/* Macro to enable/disable run-time checks. */
				#if defined(RTE_LIBRTE_LPM_DEBUG)
				#include <rte_debug.h>
				#define VERIFY_DEPTH(depth) do { \
				if ((depth == 0) \|\| (depth > RTE_LPM_MAX_DEPTH)) \
				rte_panic("LPM: Invalid depth (%u) at line %d", \
				(unsigned)(depth), __LINE__); \
				} while (0)
				#else
				#define VERIFY_DEPTH(depth)
				#endif

				/*
				* Converts a given depth value to its corresponding mask value.
				*
				* depth (IN) : range = 1 - 32
				* mask (OUT) : 32bit mask
				*/
				static uint32_t __attribute__((pure))
				depth_to_mask(uint8_t depth)
				{
				VERIFY_DEPTH(depth);

				/* To calculate a mask start with a 1 on the left hand side and right
				* shift while populating the left hand side with 1's
				*/
				return (int)0x80000000 >> (depth - 1);
				}

				/*
				* Converts given depth value to its corresponding range value.
				*/
				static uint32_t __attribute__((pure))
				depth_to_range(uint8_t depth)
				{
				VERIFY_DEPTH(depth);

				/*
				* Calculate tbl24 range. (Note: 2^depth = 1 << depth)
				*/
				if (depth <= MAX_DEPTH_TBL24)
				return 1 << (MAX_DEPTH_TBL24 - depth);

				/* Else if depth is greater than 24 */
				return 1 << (RTE_LPM_MAX_DEPTH - depth);
				}

				#if 0
				/*
				* Find an existing lpm table and return a pointer to it.
				*/
				struct rte_lpm *
				rte_lpm_find_existing(const char *name)
				{
				struct rte_lpm *l = NULL;
				struct rte_tailq_entry *te;
				struct rte_lpm_list *lpm_list;

				lpm_list = RTE_TAILQ_CAST(rte_lpm_tailq.head, rte_lpm_list);

				rte_mcfg_tailq_read_lock();
				TAILQ_FOREACH(te, lpm_list, next) {
				l = te->data;
				if (strncmp(name, l->name, RTE_LPM_NAMESIZE) == 0)
				break;
				}
				rte_mcfg_tailq_read_unlock();

				if (te == NULL) {
				rte_errno = ENOENT;
				return NULL;
				}

				return l;
				}
				#endif

				/*
				* Allocates memory for LPM object
				*/
				struct rte_lpm *
				rte_lpm_create(const char *name, int socket_id,
				const struct rte_lpm_config *config)
				{
				char mem_name[RTE_LPM_NAMESIZE];
				struct rte_lpm *lpm = NULL;
				//struct rte_tailq_entry *te;
				uint32_t mem_size, rules_size, tbl8s_size;
				//struct rte_lpm_list *lpm_list;

				//lpm_list = RTE_TAILQ_CAST(rte_lpm_tailq.head, rte_lpm_list);

				RTE_BUILD_BUG_ON(sizeof(struct rte_lpm_tbl_entry) != 4);

				/* Check user arguments. */
				if ((name == NULL) \|\| (socket_id < -1)
				\|\| config->number_tbl8s > RTE_LPM_MAX_TBL8_NUM_GROUPS) {
				rte_errno = EINVAL;
				return NULL;
				}

				snprintf(mem_name, sizeof(mem_name), "LPM_%s", name);

				/* Determine the amount of memory to allocate. */
				mem_size = sizeof(*lpm);
				rules_size = sizeof(struct rte_lpm_rule) * config->max_rules;
				tbl8s_size = (sizeof(struct rte_lpm_tbl_entry) *
				RTE_LPM_TBL8_GROUP_NUM_ENTRIES * config->number_tbl8s);

				#if 0
				rte_mcfg_tailq_write_lock();

				/* guarantee there's no existing */
				TAILQ_FOREACH(te, lpm_list, next) {
				lpm = te->data;
				if (strncmp(name, lpm->name, RTE_LPM_NAMESIZE) == 0)
				break;
				}

				if (te != NULL) {
				lpm = NULL;
				rte_errno = EEXIST;
				goto exit;
				}

				/* allocate tailq entry */
				te = rte_zmalloc("LPM_TAILQ_ENTRY", sizeof(*te), 0);
				if (te == NULL) {
				RTE_LOG(ERR, LPM, "Failed to allocate tailq entry\n");
				rte_errno = ENOMEM;
				goto exit;
				}
				#endif

				/* Allocate memory to store the LPM data structures. */
				lpm = rte_zmalloc_socket(mem_name, mem_size,
				RTE_CACHE_LINE_SIZE, socket_id);
				if (lpm == NULL) {
				RTE_LOG(ERR, LPM, "LPM memory allocation failed\n");
				//rte_free(te);
				rte_errno = ENOMEM;
				goto exit;
				}

				lpm->rules_tbl = rte_zmalloc_socket(NULL,
				(size_t)rules_size, RTE_CACHE_LINE_SIZE, socket_id);

				if (lpm->rules_tbl == NULL) {
				RTE_LOG(ERR, LPM, "LPM rules_tbl memory allocation failed\n");
				rte_free(lpm);
				lpm = NULL;
				//rte_free(te);
				rte_errno = ENOMEM;
				goto exit;
				}

				lpm->tbl8 = rte_zmalloc_socket(NULL,
				(size_t)tbl8s_size, RTE_CACHE_LINE_SIZE, socket_id);

				if (lpm->tbl8 == NULL) {
				RTE_LOG(ERR, LPM, "LPM tbl8 memory allocation failed\n");
				rte_free(lpm->rules_tbl);
				rte_free(lpm);
				lpm = NULL;
				//rte_free(te);
				rte_errno = ENOMEM;
				goto exit;
				}

				/* Save user arguments. */
				lpm->max_rules = config->max_rules;
				lpm->number_tbl8s = config->number_tbl8s;
				strlcpy(lpm->name, name, sizeof(lpm->name));

				//te->data = lpm;

				//TAILQ_INSERT_TAIL(lpm_list, te, next);

				exit:
				rte_mcfg_tailq_write_unlock();

				return lpm;
				}

				/*
				* Deallocates memory for given LPM table.
				*/
				void
				rte_lpm_free(struct rte_lpm *lpm)
				{
				#if 0
				struct rte_lpm_list *lpm_list;
				struct rte_tailq_entry *te;

				/* Check user arguments. */
				if (lpm == NULL)
				return;

				lpm_list = RTE_TAILQ_CAST(rte_lpm_tailq.head, rte_lpm_list);

				rte_mcfg_tailq_write_lock();

				/* find our tailq entry */
				TAILQ_FOREACH(te, lpm_list, next) {
				if (te->data == (void *) lpm)
				break;
				}
				if (te != NULL)
				TAILQ_REMOVE(lpm_list, te, next);

				rte_mcfg_tailq_write_unlock();
				#endif

				rte_free(lpm->tbl8);
				rte_free(lpm->rules_tbl);
				rte_free(lpm);
				//rte_free(te);
				}

				#if 0
				/*
				* Adds a rule to the rule table.
				*
				* NOTE: The rule table is split into 32 groups. Each group contains rules that
				* apply to a specific prefix depth (i.e. group 1 contains rules that apply to
				* prefixes with a depth of 1 etc.). In the following code (depth - 1) is used
				* to refer to depth 1 because even though the depth range is 1 - 32, depths
				* are stored in the rule table from 0 - 31.
				* NOTE: Valid range for depth parameter is 1 .. 32 inclusive.
				*/
				static int32_t
				rule_add(struct rte_lpm *lpm, uint32_t ip_masked, uint8_t depth,
				uint32_t next_hop)
				{
				uint32_t rule_gindex, rule_index, last_rule;
				int i;

				VERIFY_DEPTH(depth);

				/* Scan through rule group to see if rule already exists. */
				if (lpm->rule_info[depth - 1].used_rules > 0) {

				/* rule_gindex stands for rule group index. */
				rule_gindex = lpm->rule_info[depth - 1].first_rule;
				/* Initialise rule_index to point to start of rule group. */
				rule_index = rule_gindex;
				/* Last rule = Last used rule in this rule group. */
				last_rule = rule_gindex + lpm->rule_info[depth - 1].used_rules;

				for (; rule_index < last_rule; rule_index++) {

				/* If rule already exists update next hop and return. */
				if (lpm->rules_tbl[rule_index].ip == ip_masked) {

				if (lpm->rules_tbl[rule_index].next_hop
				== next_hop)
				return -EEXIST;
				lpm->rules_tbl[rule_index].next_hop = next_hop;

				return rule_index;
				}
				}

				if (rule_index == lpm->max_rules)
				return -ENOSPC;
				} else {
				/* Calculate the position in which the rule will be stored. */
				rule_index = 0;

				for (i = depth - 1; i > 0; i--) {
				if (lpm->rule_info[i - 1].used_rules > 0) {
				rule_index = lpm->rule_info[i - 1].first_rule
				+ lpm->rule_info[i - 1].used_rules;
				break;
				}
				}
				if (rule_index == lpm->max_rules)
				return -ENOSPC;

				lpm->rule_info[depth - 1].first_rule = rule_index;
				}

				/* Make room for the new rule in the array. */
				for (i = RTE_LPM_MAX_DEPTH; i > depth; i--) {
				if (lpm->rule_info[i - 1].first_rule
				+ lpm->rule_info[i - 1].used_rules == lpm->max_rules)
				return -ENOSPC;

				if (lpm->rule_info[i - 1].used_rules > 0) {
				lpm->rules_tbl[lpm->rule_info[i - 1].first_rule
				+ lpm->rule_info[i - 1].used_rules]
				= lpm->rules_tbl[lpm->rule_info[i - 1].first_rule];
				lpm->rule_info[i - 1].first_rule++;
				}
				}

				/* Add the new rule. */
				lpm->rules_tbl[rule_index].ip = ip_masked;
				lpm->rules_tbl[rule_index].next_hop = next_hop;

				/* Increment the used rules counter for this rule group. */
				lpm->rule_info[depth - 1].used_rules++;

				return rule_index;
				}

				/*
				* Delete a rule from the rule table.
				* NOTE: Valid range for depth parameter is 1 .. 32 inclusive.
				*/
				static void
				rule_delete(struct rte_lpm *lpm, int32_t rule_index, uint8_t depth)
				{
				int i;

				VERIFY_DEPTH(depth);

				lpm->rules_tbl[rule_index] =
				lpm->rules_tbl[lpm->rule_info[depth - 1].first_rule
				+ lpm->rule_info[depth - 1].used_rules - 1];

				for (i = depth; i < RTE_LPM_MAX_DEPTH; i++) {
				if (lpm->rule_info[i].used_rules > 0) {
				lpm->rules_tbl[lpm->rule_info[i].first_rule - 1] =
				lpm->rules_tbl[lpm->rule_info[i].first_rule
				+ lpm->rule_info[i].used_rules - 1];
				lpm->rule_info[i].first_rule--;
				}
				}

				lpm->rule_info[depth - 1].used_rules--;
				}

				/*
				* Finds a rule in rule table.
				* NOTE: Valid range for depth parameter is 1 .. 32 inclusive.
				*/
				static int32_t
				rule_find(struct rte_lpm *lpm, uint32_t ip_masked, uint8_t depth)
				{
				uint32_t rule_gindex, last_rule, rule_index;

				VERIFY_DEPTH(depth);

				rule_gindex = lpm->rule_info[depth - 1].first_rule;
				last_rule = rule_gindex + lpm->rule_info[depth - 1].used_rules;

				/* Scan used rules at given depth to find rule. */
				for (rule_index = rule_gindex; rule_index < last_rule; rule_index++) {
				/* If rule is found return the rule index. */
				if (lpm->rules_tbl[rule_index].ip == ip_masked)
				return rule_index;
				}

				/* If rule is not found return -EINVAL. */
				return -EINVAL;
				}
				#endif

				/*
				* Find, clean and allocate a tbl8.
				*/
				static int32_t
				tbl8_alloc(struct rte_lpm_tbl_entry *tbl8, uint32_t number_tbl8s)
				{
				uint32_t group_idx; /* tbl8 group index. */
				struct rte_lpm_tbl_entry *tbl8_entry;

				/* Scan through tbl8 to find a free (i.e. INVALID) tbl8 group. */
				for (group_idx = 0; group_idx < number_tbl8s; group_idx++) {
				tbl8_entry = &tbl8[group_idx * RTE_LPM_TBL8_GROUP_NUM_ENTRIES];
				/* If a free tbl8 group is found clean it and set as VALID. */
				if (!tbl8_entry->valid_group) {
				struct rte_lpm_tbl_entry new_tbl8_entry = {
				.next_hop = 0,
				.valid = INVALID,
				.depth = 0,
				.valid_group = VALID,
				};

				memset(&tbl8_entry[0], 0,
				RTE_LPM_TBL8_GROUP_NUM_ENTRIES *
				sizeof(tbl8_entry[0]));

				__atomic_store(tbl8_entry, &new_tbl8_entry,
				__ATOMIC_RELAXED);

				/* Return group index for allocated tbl8 group. */
				return group_idx;
				}
				}

				/* If there are no tbl8 groups free then return error. */
				return -ENOSPC;
				}

				static void
				tbl8_free(struct rte_lpm_tbl_entry *tbl8, uint32_t tbl8_group_start)
				{
				/* Set tbl8 group invalid*/
				struct rte_lpm_tbl_entry zero_tbl8_entry = {0};

				__atomic_store(&tbl8[tbl8_group_start], &zero_tbl8_entry,
				__ATOMIC_RELAXED);
				}

				static __rte_noinline int32_t
				add_depth_small(struct rte_lpm *lpm, uint32_t ip, uint8_t depth,
				uint32_t next_hop)
				{
				#define group_idx next_hop
				uint32_t tbl24_index, tbl24_range, tbl8_index, tbl8_group_end, i, j;

				/* Calculate the index into Table24. */
				tbl24_index = ip >> 8;
				tbl24_range = depth_to_range(depth);

				for (i = tbl24_index; i < (tbl24_index + tbl24_range); i++) {
				/*
				* For invalid OR valid and non-extended tbl 24 entries set
				* entry.
				*/
				if (!lpm->tbl24[i].valid \|\| (lpm->tbl24[i].valid_group == 0 &&
				lpm->tbl24[i].depth <= depth)) {

				struct rte_lpm_tbl_entry new_tbl24_entry = {
				.next_hop = next_hop,
				.valid = VALID,
				.valid_group = 0,
				.depth = depth,
				};

				/* Setting tbl24 entry in one go to avoid race
				* conditions
				*/
				__atomic_store(&lpm->tbl24[i], &new_tbl24_entry,
				__ATOMIC_RELEASE);

				continue;
				}

				if (lpm->tbl24[i].valid_group == 1) {
				/* If tbl24 entry is valid and extended calculate the
				* index into tbl8.
				*/
				tbl8_index = lpm->tbl24[i].group_idx *
				RTE_LPM_TBL8_GROUP_NUM_ENTRIES;
				tbl8_group_end = tbl8_index +
				RTE_LPM_TBL8_GROUP_NUM_ENTRIES;

				for (j = tbl8_index; j < tbl8_group_end; j++) {
				if (!lpm->tbl8[j].valid \|\|
				lpm->tbl8[j].depth <= depth) {
				struct rte_lpm_tbl_entry
				new_tbl8_entry = {
				.valid = VALID,
				.valid_group = VALID,
				.depth = depth,
				.next_hop = next_hop,
				};

				/*
				* Setting tbl8 entry in one go to avoid
				* race conditions
				*/
				__atomic_store(&lpm->tbl8[j],
				&new_tbl8_entry,
				__ATOMIC_RELAXED);

				continue;
				}
				}
				}
				}
				#undef group_idx
				return 0;
				}

				static __rte_noinline int32_t
				add_depth_big(struct rte_lpm *lpm, uint32_t ip_masked, uint8_t depth,
				uint32_t next_hop)
				{
				#define group_idx next_hop
				uint32_t tbl24_index;
				int32_t tbl8_group_index, tbl8_group_start, tbl8_group_end, tbl8_index,
				tbl8_range, i;

				tbl24_index = (ip_masked >> 8);
				tbl8_range = depth_to_range(depth);

				if (!lpm->tbl24[tbl24_index].valid) {
				/* Search for a free tbl8 group. */
				tbl8_group_index = tbl8_alloc(lpm->tbl8, lpm->number_tbl8s);

				/* Check tbl8 allocation was successful. */
				if (tbl8_group_index < 0) {
				return tbl8_group_index;
				}

				/* Find index into tbl8 and range. */
				tbl8_index = (tbl8_group_index *
				RTE_LPM_TBL8_GROUP_NUM_ENTRIES) +
				(ip_masked & 0xFF);

				/* Set tbl8 entry. */
				for (i = tbl8_index; i < (tbl8_index + tbl8_range); i++) {
				struct rte_lpm_tbl_entry new_tbl8_entry = {
				.valid = VALID,
				.depth = depth,
				.valid_group = lpm->tbl8[i].valid_group,
				.next_hop = next_hop,
				};
				__atomic_store(&lpm->tbl8[i], &new_tbl8_entry,
				__ATOMIC_RELAXED);
				}

				/*
				* Update tbl24 entry to point to new tbl8 entry. Note: The
				* ext_flag and tbl8_index need to be updated simultaneously,
				* so assign whole structure in one go
				*/

				struct rte_lpm_tbl_entry new_tbl24_entry = {
				.group_idx = tbl8_group_index,
				.valid = VALID,
				.valid_group = 1,
				.depth = 0,
				};

				/* The tbl24 entry must be written only after the
				* tbl8 entries are written.
				*/
				__atomic_store(&lpm->tbl24[tbl24_index], &new_tbl24_entry,
				__ATOMIC_RELEASE);

				} /* If valid entry but not extended calculate the index into Table8. */
				else if (lpm->tbl24[tbl24_index].valid_group == 0) {
				/* Search for free tbl8 group. */
				tbl8_group_index = tbl8_alloc(lpm->tbl8, lpm->number_tbl8s);

				if (tbl8_group_index < 0) {
				return tbl8_group_index;
				}

				tbl8_group_start = tbl8_group_index *
				RTE_LPM_TBL8_GROUP_NUM_ENTRIES;
				tbl8_group_end = tbl8_group_start +
				RTE_LPM_TBL8_GROUP_NUM_ENTRIES;

				/* Populate new tbl8 with tbl24 value. */
				for (i = tbl8_group_start; i < tbl8_group_end; i++) {
				struct rte_lpm_tbl_entry new_tbl8_entry = {
				.valid = VALID,
				.depth = lpm->tbl24[tbl24_index].depth,
				.valid_group = lpm->tbl8[i].valid_group,
				.next_hop = lpm->tbl24[tbl24_index].next_hop,
				};
				__atomic_store(&lpm->tbl8[i], &new_tbl8_entry,
				__ATOMIC_RELAXED);
				}

				tbl8_index = tbl8_group_start + (ip_masked & 0xFF);

				/* Insert new rule into the tbl8 entry. */
				for (i = tbl8_index; i < tbl8_index + tbl8_range; i++) {
				struct rte_lpm_tbl_entry new_tbl8_entry = {
				.valid = VALID,
				.depth = depth,
				.valid_group = lpm->tbl8[i].valid_group,
				.next_hop = next_hop,
				};
				__atomic_store(&lpm->tbl8[i], &new_tbl8_entry,
				__ATOMIC_RELAXED);
				}

				/*
				* Update tbl24 entry to point to new tbl8 entry. Note: The
				* ext_flag and tbl8_index need to be updated simultaneously,
				* so assign whole structure in one go.
				*/

				struct rte_lpm_tbl_entry new_tbl24_entry = {
				.group_idx = tbl8_group_index,
				.valid = VALID,
				.valid_group = 1,
				.depth = 0,
				};

				/* The tbl24 entry must be written only after the
				* tbl8 entries are written.
				*/
				__atomic_store(&lpm->tbl24[tbl24_index], &new_tbl24_entry,
				__ATOMIC_RELEASE);

				} else { /*
				* If it is valid, extended entry calculate the index into tbl8.
				*/
				tbl8_group_index = lpm->tbl24[tbl24_index].group_idx;
				tbl8_group_start = tbl8_group_index *
				RTE_LPM_TBL8_GROUP_NUM_ENTRIES;
				tbl8_index = tbl8_group_start + (ip_masked & 0xFF);

				for (i = tbl8_index; i < (tbl8_index + tbl8_range); i++) {

				if (!lpm->tbl8[i].valid \|\|
				lpm->tbl8[i].depth <= depth) {
				struct rte_lpm_tbl_entry new_tbl8_entry = {
				.valid = VALID,
				.depth = depth,
				.next_hop = next_hop,
				.valid_group = lpm->tbl8[i].valid_group,
				};

				/*
				* Setting tbl8 entry in one go to avoid race
				* condition
				*/
				__atomic_store(&lpm->tbl8[i], &new_tbl8_entry,
				__ATOMIC_RELAXED);

				continue;
				}
				}
				}
				#undef group_idx
				return 0;
				}

				/*
				* Add a route
				*/
				int
				rte_lpm_add(struct rte_lpm *lpm, uint32_t ip, uint8_t depth,
				uint32_t next_hop)
				{
				int32_t status = 0;
				uint32_t ip_masked;

				/* Check user arguments. */
				if ((lpm == NULL) \|\| (depth < 1) \|\| (depth > RTE_LPM_MAX_DEPTH))
				return -EINVAL;

				ip_masked = ip & depth_to_mask(depth);

				#if 0
				/* Add the rule to the rule table. */
				rule_index = rule_add(lpm, ip_masked, depth, next_hop);

				/* Skip table entries update if The rule is the same as
				* the rule in the rules table.
				*/
				if (rule_index == -EEXIST)
				return 0;

				/* If the is no space available for new rule return error. */
				if (rule_index < 0) {
				return rule_index;
				}
				#endif

				if (depth <= MAX_DEPTH_TBL24) {
				status = add_depth_small(lpm, ip_masked, depth, next_hop);
				} else { /* If depth > RTE_LPM_MAX_DEPTH_TBL24 */
				status = add_depth_big(lpm, ip_masked, depth, next_hop);

				/*
				* If add fails due to exhaustion of tbl8 extensions delete
				* rule that was added to rule table.
				*/
				if (status < 0) {
				//rule_delete(lpm, rule_index, depth);

				return status;
				}
				}

				return 0;
				}

				#if 0
				/*
				* Look for a rule in the high-level rules table
				*/
				int
				rte_lpm_is_rule_present(struct rte_lpm *lpm, uint32_t ip, uint8_t depth,
				uint32_t *next_hop)
				{
				uint32_t ip_masked;
				int32_t rule_index;

				/* Check user arguments. */
				if ((lpm == NULL) \|\|
				(next_hop == NULL) \|\|
				(depth < 1) \|\| (depth > RTE_LPM_MAX_DEPTH))
				return -EINVAL;

				/* Look for the rule using rule_find. */
				ip_masked = ip & depth_to_mask(depth);
				rule_index = rule_find(lpm, ip_masked, depth);

				if (rule_index >= 0) {
				*next_hop = lpm->rules_tbl[rule_index].next_hop;
				return 1;
				}

				/* If rule is not found return 0. */
				return 0;
				}

				static int32_t
				find_previous_rule(struct rte_lpm *lpm, uint32_t ip, uint8_t depth,
				uint8_t *sub_rule_depth)
				{
				int32_t rule_index;
				uint32_t ip_masked;
				uint8_t prev_depth;

				for (prev_depth = (uint8_t)(depth - 1); prev_depth > 0; prev_depth--) {
				ip_masked = ip & depth_to_mask(prev_depth);

				rule_index = rule_find(lpm, ip_masked, prev_depth);

				if (rule_index >= 0) {
				*sub_rule_depth = prev_depth;
				return rule_index;
				}
				}

				return -1;
				}
				#endif

				static int32_t
				delete_depth_small(struct rte_lpm *lpm, uint32_t ip_masked,
				uint8_t depth, uint32_t sub_rule_nhop, uint8_t sub_rule_depth)
				{
				#define group_idx next_hop
				uint32_t tbl24_range, tbl24_index, tbl8_group_index, tbl8_index, i, j;

				/* Calculate the range and index into Table24. */
				tbl24_range = depth_to_range(depth);
				tbl24_index = (ip_masked >> 8);
				struct rte_lpm_tbl_entry zero_tbl24_entry = {0};

				/*
				* Firstly check the sub_rule_index. A -1 indicates no replacement rule
				* and a positive number indicates a sub_rule_index.
				*/
				if (sub_rule_nhop == 0) {
				/*
				* If no replacement rule exists then invalidate entries
				* associated with this rule.
				*/
				for (i = tbl24_index; i < (tbl24_index + tbl24_range); i++) {

				if (lpm->tbl24[i].valid_group == 0 &&
				lpm->tbl24[i].depth <= depth) {
				__atomic_store(&lpm->tbl24[i],
				&zero_tbl24_entry, __ATOMIC_RELEASE);
				} else if (lpm->tbl24[i].valid_group == 1) {
				/*
				* If TBL24 entry is extended, then there has
				* to be a rule with depth >= 25 in the
				* associated TBL8 group.
				*/

				tbl8_group_index = lpm->tbl24[i].group_idx;
				tbl8_index = tbl8_group_index *
				RTE_LPM_TBL8_GROUP_NUM_ENTRIES;

				for (j = tbl8_index; j < (tbl8_index +
				RTE_LPM_TBL8_GROUP_NUM_ENTRIES); j++) {

				if (lpm->tbl8[j].depth <= depth)
				lpm->tbl8[j].valid = INVALID;
				}
				}
				}
				} else {
				/*
				* If a replacement rule exists then modify entries
				* associated with this rule.
				*/

				struct rte_lpm_tbl_entry new_tbl24_entry = {
				.next_hop = sub_rule_nhop,
				.valid = VALID,
				.valid_group = 0,
				.depth = sub_rule_depth,
				};

				struct rte_lpm_tbl_entry new_tbl8_entry = {
				.valid = VALID,
				.valid_group = VALID,
				.depth = sub_rule_depth,
				.next_hop = sub_rule_nhop,
				};

				for (i = tbl24_index; i < (tbl24_index + tbl24_range); i++) {

				if (lpm->tbl24[i].valid_group == 0 &&
				lpm->tbl24[i].depth <= depth) {
				__atomic_store(&lpm->tbl24[i], &new_tbl24_entry,
				__ATOMIC_RELEASE);
				} else if (lpm->tbl24[i].valid_group == 1) {
				/*
				* If TBL24 entry is extended, then there has
				* to be a rule with depth >= 25 in the
				* associated TBL8 group.
				*/

				tbl8_group_index = lpm->tbl24[i].group_idx;
				tbl8_index = tbl8_group_index *
				RTE_LPM_TBL8_GROUP_NUM_ENTRIES;

				for (j = tbl8_index; j < (tbl8_index +
				RTE_LPM_TBL8_GROUP_NUM_ENTRIES); j++) {

				if (lpm->tbl8[j].depth <= depth)
				__atomic_store(&lpm->tbl8[j],
				&new_tbl8_entry,
				__ATOMIC_RELAXED);
				}
				}
				}
				}
				#undef group_idx
				return 0;
				}

				/*
				* Checks if table 8 group can be recycled.
				*
				* Return of -EEXIST means tbl8 is in use and thus can not be recycled.
				* Return of -EINVAL means tbl8 is empty and thus can be recycled
				* Return of value > -1 means tbl8 is in use but has all the same values and
				* thus can be recycled
				*/
				static int32_t
				tbl8_recycle_check(struct rte_lpm_tbl_entry *tbl8,
				uint32_t tbl8_group_start)
				{
				uint32_t tbl8_group_end, i;
				tbl8_group_end = tbl8_group_start + RTE_LPM_TBL8_GROUP_NUM_ENTRIES;

				/*
				* Check the first entry of the given tbl8. If it is invalid we know
				* this tbl8 does not contain any rule with a depth < RTE_LPM_MAX_DEPTH
				* (As they would affect all entries in a tbl8) and thus this table
				* can not be recycled.
				*/
				if (tbl8[tbl8_group_start].valid) {
				/*
				* If first entry is valid check if the depth is less than 24
				* and if so check the rest of the entries to verify that they
				* are all of this depth.
				*/
				if (tbl8[tbl8_group_start].depth <= MAX_DEPTH_TBL24) {
				for (i = (tbl8_group_start + 1); i < tbl8_group_end;
				i++) {

				if (tbl8[i].depth !=
				tbl8[tbl8_group_start].depth) {

				return -EEXIST;
				}
				}
				/* If all entries are the same return the tb8 index */
				return tbl8_group_start;
				}

				return -EEXIST;
				}
				/*
				* If the first entry is invalid check if the rest of the entries in
				* the tbl8 are invalid.
				*/
				for (i = (tbl8_group_start + 1); i < tbl8_group_end; i++) {
				if (tbl8[i].valid)
				return -EEXIST;
				}
				/* If no valid entries are found then return -EINVAL. */
				return -EINVAL;
				}

				static int32_t
				delete_depth_big(struct rte_lpm *lpm, uint32_t ip_masked,
				uint8_t depth, uint32_t sub_rule_nhop, uint8_t sub_rule_depth)
				{
				#define group_idx next_hop
				uint32_t tbl24_index, tbl8_group_index, tbl8_group_start, tbl8_index,
				tbl8_range, i;
				int32_t tbl8_recycle_index;

				/*
				* Calculate the index into tbl24 and range. Note: All depths larger
				* than MAX_DEPTH_TBL24 are associated with only one tbl24 entry.
				*/
				tbl24_index = ip_masked >> 8;

				/* Calculate the index into tbl8 and range. */
				tbl8_group_index = lpm->tbl24[tbl24_index].group_idx;
				tbl8_group_start = tbl8_group_index * RTE_LPM_TBL8_GROUP_NUM_ENTRIES;
				tbl8_index = tbl8_group_start + (ip_masked & 0xFF);
				tbl8_range = depth_to_range(depth);

				if (sub_rule_nhop == 0) {
				/*
				* Loop through the range of entries on tbl8 for which the
				* rule_to_delete must be removed or modified.
				*/
				for (i = tbl8_index; i < (tbl8_index + tbl8_range); i++) {
				if (lpm->tbl8[i].depth <= depth)
				lpm->tbl8[i].valid = INVALID;
				}
				} else {
				/* Set new tbl8 entry. */
				struct rte_lpm_tbl_entry new_tbl8_entry = {
				.valid = VALID,
				.depth = sub_rule_depth,
				.valid_group = lpm->tbl8[tbl8_group_start].valid_group,
				.next_hop = sub_rule_nhop,
				};

				/*
				* Loop through the range of entries on tbl8 for which the
				* rule_to_delete must be modified.
				*/
				for (i = tbl8_index; i < (tbl8_index + tbl8_range); i++) {
				if (lpm->tbl8[i].depth <= depth)
				__atomic_store(&lpm->tbl8[i], &new_tbl8_entry,
				__ATOMIC_RELAXED);
				}
				}

				/*
				* Check if there are any valid entries in this tbl8 group. If all
				* tbl8 entries are invalid we can free the tbl8 and invalidate the
				* associated tbl24 entry.
				*/

				tbl8_recycle_index = tbl8_recycle_check(lpm->tbl8, tbl8_group_start);

				if (tbl8_recycle_index == -EINVAL) {
				/* Set tbl24 before freeing tbl8 to avoid race condition.
				* Prevent the free of the tbl8 group from hoisting.
				*/
				lpm->tbl24[tbl24_index].valid = 0;
				__atomic_thread_fence(__ATOMIC_RELEASE);
				tbl8_free(lpm->tbl8, tbl8_group_start);
				} else if (tbl8_recycle_index > -1) {
				/* Update tbl24 entry. */
				struct rte_lpm_tbl_entry new_tbl24_entry = {
				.next_hop = lpm->tbl8[tbl8_recycle_index].next_hop,
				.valid = VALID,
				.valid_group = 0,
				.depth = lpm->tbl8[tbl8_recycle_index].depth,
				};

				/* Set tbl24 before freeing tbl8 to avoid race condition.
				* Prevent the free of the tbl8 group from hoisting.
				*/
				__atomic_store(&lpm->tbl24[tbl24_index], &new_tbl24_entry,
				__ATOMIC_RELAXED);
				__atomic_thread_fence(__ATOMIC_RELEASE);
				tbl8_free(lpm->tbl8, tbl8_group_start);
				}
				#undef group_idx
				return 0;
				}

				/*
				* Deletes a rule
				*/
				int
				rte_lpm_delete(struct rte_lpm *lpm, uint32_t ip, uint8_t depth,
				uint8_t sub_rule_depth, uint32_t sub_rule_nhop)
				{
				//int32_t rule_to_delete_index;
				uint32_t ip_masked;
				//uint8_t sub_rule_depth;
				/*
				* Check input arguments. Note: IP must be a positive integer of 32
				* bits in length therefore it need not be checked.
				*/
				if ((lpm == NULL) \|\| (depth < 1) \|\| (depth > RTE_LPM_MAX_DEPTH)) {
				return -EINVAL;
				}

				ip_masked = ip & depth_to_mask(depth);

				#if 0
				/*
				* Find the index of the input rule, that needs to be deleted, in the
				* rule table.
				*/
				rule_to_delete_index = rule_find(lpm, ip_masked, depth);

				/*
				* Check if rule_to_delete_index was found. If no rule was found the
				* function rule_find returns -EINVAL.
				*/
				if (rule_to_delete_index < 0)
				return -EINVAL;

				/* Delete the rule from the rule table. */
				rule_delete(lpm, rule_to_delete_index, depth);
				#endif

				/*
				* Find rule to replace the rule_to_delete. If there is no rule to
				* replace the rule_to_delete we return -1 and invalidate the table
				* entries associated with this rule.
				*/
				//sub_rule_depth = *psub_rule_depth;
				//sub_rule_index = find_previous_rule(lpm, ip, depth, &sub_rule_depth);

				/*
				* If the input depth value is less than 25 use function
				* delete_depth_small otherwise use delete_depth_big.
				*/
				if (depth <= MAX_DEPTH_TBL24) {
				return delete_depth_small(lpm, ip_masked, depth,
				sub_rule_nhop, sub_rule_depth);
				} else { /* If depth > MAX_DEPTH_TBL24 */
				return delete_depth_big(lpm, ip_masked, depth, sub_rule_nhop,
				sub_rule_depth);
				}
				}

				/*
				* Delete all rules from the LPM table.
				*/
				void
				rte_lpm_delete_all(struct rte_lpm *lpm)
				{
				/* Zero rule information. */
				memset(lpm->rule_info, 0, sizeof(lpm->rule_info));

				/* Zero tbl24. */
				memset(lpm->tbl24, 0, sizeof(lpm->tbl24));

				/* Zero tbl8. */
				memset(lpm->tbl8, 0, sizeof(lpm->tbl8[0])
				* RTE_LPM_TBL8_GROUP_NUM_ENTRIES * lpm->number_tbl8s);

				/* Delete all rules form the rules table. */
				memset(lpm->rules_tbl, 0, sizeof(lpm->rules_tbl[0]) * lpm->max_rules);
				}