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40 * RTE Longest Prefix Match (LPM)
44 #include <sys/queue.h>
47 #include <rte_branch_prediction.h>
48 #include <rte_memory.h>
54 /** Max number of characters in LPM name. */
55 #define RTE_LPM_NAMESIZE 32
57 /** Possible location to allocate memory. */
58 #define RTE_LPM_HEAP 0
60 /** Possible location to allocate memory. */
61 #define RTE_LPM_MEMZONE 1
63 /** Maximum depth value possible for IPv4 LPM. */
64 #define RTE_LPM_MAX_DEPTH 32
66 /** Total number of tbl24 entries. */
67 #define RTE_LPM_TBL24_NUM_ENTRIES (1 << 24)
69 /** Number of entries in a tbl8 group. */
70 #define RTE_LPM_TBL8_GROUP_NUM_ENTRIES 256
72 /** Total number of tbl8 groups in the tbl8. */
73 #define RTE_LPM_TBL8_NUM_GROUPS 256
75 /** Total number of tbl8 entries. */
76 #define RTE_LPM_TBL8_NUM_ENTRIES (RTE_LPM_TBL8_NUM_GROUPS * \
77 RTE_LPM_TBL8_GROUP_NUM_ENTRIES)
79 /** Macro to enable/disable run-time checks. */
80 #if defined(RTE_LIBRTE_LPM_DEBUG)
81 #define RTE_LPM_RETURN_IF_TRUE(cond, retval) do { \
82 if (cond) return (retval); \
85 #define RTE_LPM_RETURN_IF_TRUE(cond, retval)
88 /** Tbl24 entry structure. */
89 struct rte_lpm_tbl24_entry {
90 /* Using single uint8_t to store 3 values. */
91 uint8_t valid :1; /**< Validation flag. */
92 uint8_t ext_entry :1; /**< External entry. */
93 uint8_t depth :6; /**< Rule depth. */
94 /* Stores Next hop or group index (i.e. gindex)into tbl8. */
101 /** Tbl8 entry structure. */
102 struct rte_lpm_tbl8_entry {
103 /* Using single uint8_t to store 3 values. */
104 uint8_t valid :1; /**< Validation flag. */
105 uint8_t valid_group :1; /**< Group validation flag. */
106 uint8_t depth :6; /**< Rule depth. */
107 uint8_t next_hop; /**< next hop. */
110 /** Rule structure. */
111 struct rte_lpm_rule {
112 uint32_t ip; /**< Rule IP address. */
113 uint8_t next_hop; /**< Rule next hop. */
116 /** LPM structure. */
118 TAILQ_ENTRY(rte_lpm) next; /**< Next in list. */
121 char name[RTE_LPM_NAMESIZE]; /**< Name of the lpm. */
122 int mem_location; /**< Location of memory to be allocated. */
123 uint32_t max_rules_per_depth; /**< Max. balanced rules per lpm. */
124 uint32_t used_rules_at_depth[RTE_LPM_MAX_DEPTH]; /**< Rules / depth. */
127 struct rte_lpm_tbl24_entry tbl24[RTE_LPM_TBL24_NUM_ENTRIES] \
128 __rte_cache_aligned; /**< LPM tbl24 table. */
129 struct rte_lpm_tbl8_entry tbl8[RTE_LPM_TBL8_NUM_ENTRIES] \
130 __rte_cache_aligned; /**< LPM tbl8 table. */
131 struct rte_lpm_rule rules_tbl[0] \
132 __rte_cache_aligned; /**< LPM rules. */
136 * Create an LPM object.
141 * NUMA socket ID for LPM table memory allocation
143 * Maximum number of LPM rules that can be added
144 * @param mem_location
145 * Location of memory to be allocated. Can only be RTE_LPM_HEAP or
148 * Handle to LPM object on success, NULL otherwise with rte_errno set
149 * to an appropriate values. Possible rte_errno values include:
150 * - E_RTE_NO_CONFIG - function could not get pointer to rte_config structure
151 * - E_RTE_SECONDARY - function was called from a secondary process instance
152 * - E_RTE_NO_TAILQ - no tailq list could be got for the lpm object list
153 * - EINVAL - invalid parameter passed to function
154 * - ENOSPC - the maximum number of memzones has already been allocated
155 * - EEXIST - a memzone with the same name already exists
156 * - ENOMEM - no appropriate memory area found in which to create memzone
159 rte_lpm_create(const char *name, int socket_id, int max_rules,
163 * Find an existing LPM object and return a pointer to it.
166 * Name of the lpm object as passed to rte_lpm_create()
168 * Pointer to lpm object or NULL if object not found with rte_errno
169 * set appropriately. Possible rte_errno values include:
170 * - ENOENT - required entry not available to return.
173 rte_lpm_find_existing(const char *name);
176 * Free an LPM object.
184 rte_lpm_free(struct rte_lpm *lpm);
187 * Add a rule to the LPM table.
192 * IP of the rule to be added to the LPM table
194 * Depth of the rule to be added to the LPM table
196 * Next hop of the rule to be added to the LPM table
198 * 0 on success, negative value otherwise
201 rte_lpm_add(struct rte_lpm *lpm, uint32_t ip, uint8_t depth, uint8_t next_hop);
204 * Delete a rule from the LPM table.
209 * IP of the rule to be deleted from the LPM table
211 * Depth of the rule to be deleted from the LPM table
213 * 0 on success, negative value otherwise
216 rte_lpm_delete(struct rte_lpm *lpm, uint32_t ip, uint8_t depth);
219 * Delete all rules from the LPM table.
225 rte_lpm_delete_all(struct rte_lpm *lpm);
228 * Lookup an IP into the LPM table.
233 * IP to be looked up in the LPM table
235 * Next hop of the most specific rule found for IP (valid on lookup hit only)
237 * -EINVAL for incorrect arguments, -ENOENT on lookup miss, 0 on lookup hit
240 rte_lpm_lookup(struct rte_lpm *lpm, uint32_t ip, uint8_t *next_hop)
242 uint32_t tbl24_index, tbl8_group_index, tbl8_index;
244 /* DEBUG: Check user input arguments. */
245 RTE_LPM_RETURN_IF_TRUE(((lpm == NULL) || (next_hop == NULL)), -EINVAL);
247 /* Calculate index into tbl24. */
248 tbl24_index = (ip >> 8);
251 * Use the tbl24_index to access the required tbl24 entry then check if
252 * the tbl24 entry is INVALID, if so return -ENOENT.
254 if (!lpm->tbl24[tbl24_index].valid){
255 return -ENOENT; /* Lookup miss. */
258 * If tbl24 entry is valid check if it is NOT extended (i.e. it does
259 * not use a tbl8 extension) if so return the next hop.
261 if (likely(lpm->tbl24[tbl24_index].ext_entry == 0)) {
262 *next_hop = lpm->tbl24[tbl24_index].next_hop;
263 return 0; /* Lookup hit. */
267 * If tbl24 entry is valid and extended calculate the index into the
270 tbl8_group_index = lpm->tbl24[tbl24_index].tbl8_gindex;
271 tbl8_index = (tbl8_group_index * RTE_LPM_TBL8_GROUP_NUM_ENTRIES) +
274 /* Check if the tbl8 entry is invalid and if so return -ENOENT. */
275 if (!lpm->tbl8[tbl8_index].valid)
276 return -ENOENT;/* Lookup miss. */
278 /* If the tbl8 entry is valid return return the next_hop. */
279 *next_hop = lpm->tbl8[tbl8_index].next_hop;
280 return 0; /* Lookup hit. */
287 #endif /* _RTE_LPM_H_ */