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33 * version: DPDK.L.1.2.3-3
41 * RTE Longest Prefix Match (LPM)
45 #include <sys/queue.h>
48 #include <rte_branch_prediction.h>
49 #include <rte_memory.h>
55 /** Max number of characters in LPM name. */
56 #define RTE_LPM_NAMESIZE 32
58 /** Possible location to allocate memory. */
59 #define RTE_LPM_HEAP 0
61 /** Possible location to allocate memory. */
62 #define RTE_LPM_MEMZONE 1
64 /** Maximum depth value possible for IPv4 LPM. */
65 #define RTE_LPM_MAX_DEPTH 32
67 /** Total number of tbl24 entries. */
68 #define RTE_LPM_TBL24_NUM_ENTRIES (1 << 24)
70 /** Number of entries in a tbl8 group. */
71 #define RTE_LPM_TBL8_GROUP_NUM_ENTRIES 256
73 /** Total number of tbl8 groups in the tbl8. */
74 #define RTE_LPM_TBL8_NUM_GROUPS 256
76 /** Total number of tbl8 entries. */
77 #define RTE_LPM_TBL8_NUM_ENTRIES (RTE_LPM_TBL8_NUM_GROUPS * \
78 RTE_LPM_TBL8_GROUP_NUM_ENTRIES)
80 /** Macro to enable/disable run-time checks. */
81 #if defined(RTE_LIBRTE_LPM_DEBUG)
82 #define RTE_LPM_RETURN_IF_TRUE(cond, retval) do { \
83 if (cond) return (retval); \
86 #define RTE_LPM_RETURN_IF_TRUE(cond, retval)
89 /** Tbl24 entry structure. */
90 struct rte_lpm_tbl24_entry {
91 /* Using single uint8_t to store 3 values. */
92 uint8_t valid :1; /**< Validation flag. */
93 uint8_t ext_entry :1; /**< External entry. */
94 uint8_t depth :6; /**< Rule depth. */
95 /* Stores Next hop or group index (i.e. gindex)into tbl8. */
102 /** Tbl8 entry structure. */
103 struct rte_lpm_tbl8_entry {
104 /* Using single uint8_t to store 3 values. */
105 uint8_t valid :1; /**< Validation flag. */
106 uint8_t valid_group :1; /**< Group validation flag. */
107 uint8_t depth :6; /**< Rule depth. */
108 uint8_t next_hop; /**< next hop. */
111 /** Rule structure. */
112 struct rte_lpm_rule {
113 uint32_t ip; /**< Rule IP address. */
114 uint8_t next_hop; /**< Rule next hop. */
117 /** LPM structure. */
119 TAILQ_ENTRY(rte_lpm) next; /**< Next in list. */
122 char name[RTE_LPM_NAMESIZE]; /**< Name of the lpm. */
123 int mem_location; /**< Location of memory to be allocated. */
124 uint32_t max_rules_per_depth; /**< Max. balanced rules per lpm. */
125 uint32_t used_rules_at_depth[RTE_LPM_MAX_DEPTH]; /**< Rules / depth. */
128 struct rte_lpm_tbl24_entry tbl24[RTE_LPM_TBL24_NUM_ENTRIES] \
129 __rte_cache_aligned; /**< LPM tbl24 table. */
130 struct rte_lpm_tbl8_entry tbl8[RTE_LPM_TBL8_NUM_ENTRIES] \
131 __rte_cache_aligned; /**< LPM tbl8 table. */
132 struct rte_lpm_rule rules_tbl[0] \
133 __rte_cache_aligned; /**< LPM rules. */
137 * Create an LPM object.
142 * NUMA socket ID for LPM table memory allocation
144 * Maximum number of LPM rules that can be added
145 * @param mem_location
146 * Location of memory to be allocated. Can only be RTE_LPM_HEAP or
149 * Handle to LPM object on success, NULL otherwise with rte_errno set
150 * to an appropriate values. Possible rte_errno values include:
151 * - E_RTE_NO_CONFIG - function could not get pointer to rte_config structure
152 * - E_RTE_SECONDARY - function was called from a secondary process instance
153 * - E_RTE_NO_TAILQ - no tailq list could be got for the lpm object list
154 * - EINVAL - invalid parameter passed to function
155 * - ENOSPC - the maximum number of memzones has already been allocated
156 * - EEXIST - a memzone with the same name already exists
157 * - ENOMEM - no appropriate memory area found in which to create memzone
160 rte_lpm_create(const char *name, int socket_id, int max_rules,
164 * Find an existing LPM object and return a pointer to it.
167 * Name of the lpm object as passed to rte_lpm_create()
169 * Pointer to lpm object or NULL if object not found with rte_errno
170 * set appropriately. Possible rte_errno values include:
171 * - ENOENT - required entry not available to return.
174 rte_lpm_find_existing(const char *name);
177 * Free an LPM object.
185 rte_lpm_free(struct rte_lpm *lpm);
188 * Add a rule to the LPM table.
193 * IP of the rule to be added to the LPM table
195 * Depth of the rule to be added to the LPM table
197 * Next hop of the rule to be added to the LPM table
199 * 0 on success, negative value otherwise
202 rte_lpm_add(struct rte_lpm *lpm, uint32_t ip, uint8_t depth, uint8_t next_hop);
205 * Delete a rule from the LPM table.
210 * IP of the rule to be deleted from the LPM table
212 * Depth of the rule to be deleted from the LPM table
214 * 0 on success, negative value otherwise
217 rte_lpm_delete(struct rte_lpm *lpm, uint32_t ip, uint8_t depth);
220 * Delete all rules from the LPM table.
226 rte_lpm_delete_all(struct rte_lpm *lpm);
229 * Lookup an IP into the LPM table.
234 * IP to be looked up in the LPM table
236 * Next hop of the most specific rule found for IP (valid on lookup hit only)
238 * -EINVAL for incorrect arguments, -ENOENT on lookup miss, 0 on lookup hit
241 rte_lpm_lookup(struct rte_lpm *lpm, uint32_t ip, uint8_t *next_hop)
243 uint32_t tbl24_index, tbl8_group_index, tbl8_index;
245 /* DEBUG: Check user input arguments. */
246 RTE_LPM_RETURN_IF_TRUE(((lpm == NULL) || (next_hop == NULL)), -EINVAL);
248 /* Calculate index into tbl24. */
249 tbl24_index = (ip >> 8);
252 * Use the tbl24_index to access the required tbl24 entry then check if
253 * the tbl24 entry is INVALID, if so return -ENOENT.
255 if (!lpm->tbl24[tbl24_index].valid){
256 return -ENOENT; /* Lookup miss. */
259 * If tbl24 entry is valid check if it is NOT extended (i.e. it does
260 * not use a tbl8 extension) if so return the next hop.
262 if (likely(lpm->tbl24[tbl24_index].ext_entry == 0)) {
263 *next_hop = lpm->tbl24[tbl24_index].next_hop;
264 return 0; /* Lookup hit. */
268 * If tbl24 entry is valid and extended calculate the index into the
271 tbl8_group_index = lpm->tbl24[tbl24_index].tbl8_gindex;
272 tbl8_index = (tbl8_group_index * RTE_LPM_TBL8_GROUP_NUM_ENTRIES) +
275 /* Check if the tbl8 entry is invalid and if so return -ENOENT. */
276 if (!lpm->tbl8[tbl8_index].valid)
277 return -ENOENT;/* Lookup miss. */
279 /* If the tbl8 entry is valid return return the next_hop. */
280 *next_hop = lpm->tbl8[tbl8_index].next_hop;
281 return 0; /* Lookup hit. */
288 #endif /* _RTE_LPM_H_ */