Function add_step

dpdk/lib/lpm/rte_lpm6.c:647–805

* Partially adds a new route to the data structure (tbl24+tbl8s). * It returns 0 on success, a negative number on failure, or 1 if * the process needs to be continued by calling the function again. */

 * the process needs to be continued by calling the function again.
 */
static inline int
add_step(struct rte_lpm6 *lpm, struct rte_lpm6_tbl_entry *tbl,
		uint32_t tbl_ind, struct rte_lpm6_tbl_entry **next_tbl,
		uint32_t *next_tbl_ind, uint8_t *ip, uint8_t bytes,
		uint8_t first_byte, uint8_t depth, uint32_t next_hop,
		uint8_t is_new_rule)
{
	uint32_t entry_ind, tbl_range, tbl8_group_start, tbl8_group_end, i;
	uint32_t tbl8_gindex;
	uint8_t bits_covered;
	int ret;

	/*
	 * Calculate index to the table based on the number and position
	 * of the bytes being inspected in this step.
	 */
	entry_ind = get_bitshift(ip, first_byte, bytes);

	/* Number of bits covered in this step */
	bits_covered = (uint8_t)((bytes+first_byte-1)*BYTE_SIZE);

	/*
	 * If depth if smaller than this number (ie this is the last step)
	 * expand the rule across the relevant positions in the table.
	 */
	if (depth <= bits_covered) {
		tbl_range = 1 << (bits_covered - depth);

		for (i = entry_ind; i < (entry_ind + tbl_range); i++) {
			if (!tbl[i].valid || (tbl[i].ext_entry == 0 &&
					tbl[i].depth <= depth)) {

				struct rte_lpm6_tbl_entry new_tbl_entry = {
					.next_hop = next_hop,
					.depth = depth,
					.valid = VALID,
					.valid_group = VALID,
					.ext_entry = 0,
				};

				tbl[i] = new_tbl_entry;

			} else if (tbl[i].ext_entry == 1) {

				/*
				 * If tbl entry is valid and extended calculate the index
				 * into next tbl8 and expand the rule across the data structure.
				 */
				tbl8_gindex = tbl[i].lpm6_tbl8_gindex *
						RTE_LPM6_TBL8_GROUP_NUM_ENTRIES;
				expand_rule(lpm, tbl8_gindex, depth, depth,
						next_hop, VALID);
			}
		}

		/* update tbl8 rule reference counter */
		if (tbl_ind != TBL24_IND && is_new_rule)
			lpm->tbl8_hdrs[tbl_ind].ref_cnt++;